WorldWideScience

Sample records for average glandular dose

  1. Average glandular dose in patients submitted to mammographic examinations

    International Nuclear Information System (INIS)

    Doses in mammography should be maintained as low as possible without reducing the high image quality needed to the early detection of the breast cancer. As the breast is composed of tissues with very soft composition and densities, it increases the difficulty to detect small changes in the normal anatomical structures that may be associated with breast cancer. To achieve the standards of resolution and contrast for mammography, the quality and intensity of the X-ray beam, the breast positioning and compression, the film screen system, and the film processing must be in optimal operational conditions. This study intended to evaluate the mean glandular dose of patients undergoing routine exams in one mammography unit. Patient image analyses were done by a radiologist doctor who took into account 10 evaluation criteria for each CC and MLO incidences. For estimating each patient glandular dose the radiographic technique parameters (kV and mAs) and the thickness of the compressed breast were recorded. European image quality criteria were adopted by the radiologist doctor to accept the image for diagnostic purpose. For breast densities of 50% adipose and 50% glandular tissues the incident air-kerma was measured and the glandular dose calculated considering the x-ray output during the exam. In the study of 50 patients the mean glandular dose varied from 0.90 to 3.27 mGy with a mean value of 1.98 mGy for CC incidences. For MLO incidences the mean glandular doses ranged from 0.97 to 3.98 mGy and a mean value of 2.60 mGy. (author)

  2. Average glandular dose in digital mammography and breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Olgar, T. [Ankara Univ. (Turkey). Dept. of Engineering Physics; Universitaetsklinikum Leipzig AoeR (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Kahn, T.; Gosch, D. [Universitaetsklinikum Leipzig AoeR (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie

    2012-10-15

    Purpose: To determine the average glandular dose (AGD) in digital full-field mammography (2 D imaging mode) and in breast tomosynthesis (3 D imaging mode). Materials and Methods: Using the method described by Boone, the AGD was calculated from the exposure parameters of 2247 conventional 2 D mammograms and 984 mammograms in 3 D imaging mode of 641 patients examined with the digital mammographic system Hologic Selenia Dimensions. The breast glandular tissue content was estimated by the Hologic R2 Quantra automated volumetric breast density measurement tool for each patient from right craniocaudal (RCC) and left craniocaudal (LCC) images in 2 D imaging mode. Results: The mean compressed breast thickness (CBT) was 52.7 mm for craniocaudal (CC) and 56.0 mm for mediolateral oblique (MLO) views. The mean percentage of breast glandular tissue content was 18.0 % and 17.4 % for RCC and LCC projections, respectively. The mean AGD values in 2 D imaging mode per exposure for the standard breast were 1.57 mGy and 1.66 mGy, while the mean AGD values after correction for real breast composition were 1.82 mGy and 1.94 mGy for CC and MLO views, respectively. The mean AGD values in 3 D imaging mode per exposure for the standard breast were 2.19 mGy and 2.29 mGy, while the mean AGD values after correction for the real breast composition were 2.53 mGy and 2.63 mGy for CC and MLO views, respectively. No significant relationship was found between the AGD and CBT in 2 D imaging mode and a good correlation coefficient of 0.98 in 3 D imaging mode. Conclusion: In this study the mean calculated AGD per exposure in 3 D imaging mode was on average 34 % higher than for 2 D imaging mode for patients examined with the same CBT.

  3. Evaluation of exposure in mammography: limitations of average glandular dose and proposal of a new quantity

    International Nuclear Information System (INIS)

    The radiation risk in mammography is traditionally evaluated using the average glandular dose. This quantity for the average breast has proven to be useful for population statistics and to compare exposure techniques and systems. However it is not indicating the individual radiation risk based on the individual glandular amount and distribution. Simulations of exposures were performed for six appropriate virtual phantoms with varying glandular amount and distribution. The individualised average glandular dose (iAGD), i.e. the individual glandular absorbed energy divided by the mass of the gland, and the glandular imparted energy (GIE), i.e. the glandular absorbed energy, were computed. Both quantities were evaluated for their capability to take into account the glandular amount and distribution. As expected, the results have demonstrated that iAGD reflects only the distribution, while GIE reflects both the glandular amount and distribution. Therefore GIE is a good candidate for individual radiation risk assessment. (authors)

  4. Analysis of patient exposure dose for mammography. Estimation of average glandular dose in 1998 questionnaire

    International Nuclear Information System (INIS)

    Recently, patient exposure dose for mammography are varied because of a great demand for mammography, which non-palpable lesion can be detected, diffusion of special X-ray equipment, progress of CR and enlightenment or study on mammography in Japanese society of radiological technology. Therefore, the newest patient exposure dose obtained from '98 questionnaire carried out to the whole country in Japan was investigated. Furthermore, the average glandular dose based on '98 was compared with that of '93. The average glandular dose can be calculated from the product of the breast entrance skin exposure and DgN (the average glandular dose per unit entrance skin exposure). The breast entrance skin dose was estimated from the dose of 782 institutions in '98, which was calculated from data measured at 51 institutions in Tokai and Hokuriku area. DgN was used published table of 50% adipose-50% glandular breast composition and 4.2 cm breast thickness corresponding to measured half-value layer (HVL) on each tube voltages. Then, patient exposure dose for mammography was estimated from exposure condition (tube voltage, mAs value) obtained '98 questionnaire. The dose in '98 estimated 1.422 mGy was reduced that compared with in '93 estimated 1.610 mGy. The dose of '98 without grid was reduced about 30% of '93. The dose of 98 with grid was not any reduced than the dose of '93. However, the number of institution of '98 with grid was about 2.8 times than '93. The patient exposure dose for mammography was reduced approximately 10% during 5 years. There are probability that mammography with grid for guidance level will be 1.5 mGy. (author)

  5. Evaluation of subject contrast and normalized average glandular dose by semi-analytical models

    International Nuclear Information System (INIS)

    In this work, two semi-analytical models are described to evaluate the subject contrast of nodules and the normalized average glandular dose in mammography. Both models were used to study the influence of some parameters, such as breast characteristics (thickness and composition) and incident spectra (kVp and target-filter combination) on the subject contrast of a nodule and on the normalized average glandular dose. From the subject contrast results, detection limits of nodules were also determined. Our results are in good agreement with those reported by other authors, who had used Monte Carlo simulation, showing the robustness of our semi-analytical method.

  6. Effect of anode/filter combination on average glandular dose in mammography

    Directory of Open Access Journals (Sweden)

    Michal Biegala

    2015-01-01

    Full Text Available A comparative analysis of the mean glandular doses was conducted in 100 female patients who underwent screening mammography in 2011 and 2013. Siemens Mammomat Novation with the application of the W/Rh anode/filter combination was used in 2011, whereas in 2013 anode/filter combination was Mo/Mo or Mo/Rh. The functioning of mammography was checked and the effectiveness of the automatic exposure control (AEC system was verified by measuring compensation of changes in the phantom thickness and measuring tube voltage. On the base of exposure parameters, an average glandular dose for each of 100 female patients was estimated. The images obtained by using AEC system had the acceptable threshold contrast visibility irrespective of the applied anode/filter combination. Mean glandular doses in the females, examined with the application of the W/Rh anode/filter combination, were on average 23.6% lower than that of the Mo/Mo or Mo/Rh anode/filter combinations. It is recommended to use a combination of the W/Rh anode /filter which exhibited lower mean glandular doses.

  7. Average glandular dose with amorphous silicon full-field digital mammography - clinical results

    International Nuclear Information System (INIS)

    Purpose: Determination of average glandular dose with a full-field digital mammography system using a flat-panel X-ray detector based on amorphous silicon technology for a large group of patients. Material and Methods: The patient group includes women who were examined in a 4-month period with the digital mammographic system Senographe 2000D. The number of women was 591 and the number of exposures was 1116; only cranio-caudal projections were considered. Various quantities, including entrance surface air kerma, tube loading, and compressed breast thickness, were determined during actual mammography. Average glandular dose was determined using conversion factors g for standard breast composition. Results: The mean average glandular dose was 1.51 mGy (0.66-4.05 mGy) for a single view. The mean compressed breast thickness was 55.7 mm. The mean age of patients was 55 years (34-81 years). Conclusion: The results demonstrate that full-field digital mammography with a flat-panel detector based on amorphous silicon needs about 25% less dose in comparison with conventional screen-film mammography. (orig.)

  8. Average glandular dose in routine mammography screening using a Sectra Microdose Mammography unit

    International Nuclear Information System (INIS)

    The Sectra MicroDose Mammography system is based on direct photon counting (with a solid-state detector), and a substantially lower dose to the breast than when using conventional system can be expected. In this work absorbed dose measurements have been performed for the first unit used in routine mammography screening (at the Hospitals of Helsingborg (Sweden)). Two European protocols on dosimetry in mammography have been followed. Measurement of half value layer (HVL) cannot be performed as prescribed, but this study has demonstrated than non-invasive measurements of HVL can be performed accurately with a sensitive and well collimated solid-state detector with simultaneous correction for the energy dependence. The average glandular dose for a 50 mm standard breast with 50% glandularity, simulated by 45 mm polymethylmethacrylate, was found to be 0.21 and 0.28 mGy in March and December 2004, respectively. These values are much lower than for any other mammography system on the market today. It has to be stressed that the measurement were made using the current clinical settings and that no systematic optimisation of the relationship between absorbed dose and diagnostic image quality has been performed within the present study. In order to further increase the accuracy of absorbed dose measurements for this unit, the existing dose protocols should be revised to account also for the tungsten/aluminium anode/filter combination, the multi-slit pre-collimator device and the occurrence of a dose profile in the scanning direction. (authors)

  9. Evaluation of average glandular dose in digital and conventional systems of the mammography

    International Nuclear Information System (INIS)

    Mammography is currently the most effective method of diagnosis and detection of breast pathologies. The main interest in this kid of exam comes from the high incidence rate of breast cancer and necessity of high quality images for accurate diagnosis. Digital mammography systems have several advantages compared to conventional systems, however the use of digital imaging systems is not always integrated to an image acquisition protocol. Therefore, it is questionable if digital systems truly reduce the dose received by the patient, because many times is introduced in the clinics without optimization of the image acquisition protocols. The aim of this study is to estimate the value of incident air Kerma and average glandular dose (AGD) in patients undergoing conventional and digital mammography systems in Recife. This study was conducted with 650 patients in three hospitals. The value of incident air Kerma was estimated from the measurement of the yield of equipment and irradiation parameters used for each patient. From these results and using the methodology proposed by Dance et al. the value of the average glandular dose was calculated. The results obtained show that the lowest value of AGD was found with conventional screen-film system, indicating that the parameters for image acquisition with digital systems are not optimized. It was also observed that the institutions with digital systems use lower breast compression values than the conventional. (author)

  10. Effect of filter on average glandular dose and image quality in digital mammography

    Science.gov (United States)

    Songsaeng, C.; Krisanachinda, A.; Theerakul, K.

    2016-03-01

    To determine the average glandular dose and entrance surface air kerma in both phantoms and patients to assess image quality for different target-filters (W/Rh and W/Ag) in digital mammography system. The compressed breast thickness, compression force, average glandular dose, entrance surface air kerma, peak kilovoltage and tube current time were recorded and compared between W/Rh and W/Ag target filter. The CNR and the figure of merit were used to determine the effect of target filter on image quality. The mean AGD of the W/Rh target filter was 1.75 mGy, the mean ESAK was 6.67 mGy, the mean CBT was 54.1 mm, the mean CF was 14 1bs. The mean AGD of W/Ag target filter was 2.7 mGy, the mean ESAK was 12.6 mGy, the mean CBT was 75.5 mm, the mean CF was 15 1bs. In phantom study, the AGD was 1.2 mGy at 4 cm, 3.3 mGy at 6 cm and 3.83 mGy at 7 cm thickness. The FOM was 24.6, CNR was 9.02 at thickness 6 cm. The FOM was 18.4, CNR was 8.6 at thickness 7 cm. The AGD from Digital Mammogram system with W/Rh of thinner CBT was lower than the AGD from W/Ag target filter.

  11. Evaluation of average glandular dose in digital and conventional systems of the mammography; Avaliacao da dose glandular media em sistemas digitais e convencionais de mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Aline C.S.; Barros, Vinicius S.M.; Khoury, Hellen J., E-mail: alinecx90@gmail.com, E-mail: vsmdbarros@gmail.com, E-mail: hjkhoury@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Mello, Francisca A. de, E-mail: francissamello@yahoo.com.br [Hospital das Clinicas do Recife (HCR/UFPE), PE (Brazil)

    2014-07-01

    Mammography is currently the most effective method of diagnosis and detection of breast pathologies. The main interest in this kid of exam comes from the high incidence rate of breast cancer and necessity of high quality images for accurate diagnosis. Digital mammography systems have several advantages compared to conventional systems, however the use of digital imaging systems is not always integrated to an image acquisition protocol. Therefore, it is questionable if digital systems truly reduce the dose received by the patient, because many times is introduced in the clinics without optimization of the image acquisition protocols. The aim of this study is to estimate the value of incident air Kerma and average glandular dose (AGD) in patients undergoing conventional and digital mammography systems in Recife. This study was conducted with 650 patients in three hospitals. The value of incident air Kerma was estimated from the measurement of the yield of equipment and irradiation parameters used for each patient. From these results and using the methodology proposed by Dance et al. the value of the average glandular dose was calculated. The results obtained show that the lowest value of AGD was found with conventional screen-film system, indicating that the parameters for image acquisition with digital systems are not optimized. It was also observed that the institutions with digital systems use lower breast compression values than the conventional. (author)

  12. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    Science.gov (United States)

    Bouwman, R. W.; van Engen, R. E.; Young, K. C.; den Heeten, G. J.; Broeders, M. J. M.; Schopphoven, S.; Jeukens, C. R. L. P. N.; Veldkamp, W. J. H.; Dance, D. R.

    2015-10-01

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last decades the automatic exposure control (AEC) increased in complexity and became more sensitive to (local) differences in breast composition. The question is how well the AGD estimated using these simple dosimetry phantoms agrees with the average patient AGD. In this study the AGDs for both dosimetry phantoms and for patients have been evaluated for 5 different x-ray systems in DM and DBT modes. It was found that the ratios between patient and phantom AGD did not differ considerably using both dosimetry phantoms. These ratios averaged over all breast thicknesses were 1.14 and 1.15 for the PMMA and PMMA-PE dosimetry phantoms respectively in DM mode and 1.00 and 1.02 in the DBT mode. These ratios were deemed to be sufficiently close to unity to be suitable for dosimetry evaluation in quality control procedures. However care should be taken when comparing systems for DM and DBT since depending on the AEC operation, ratios for particular breast thicknesses may differ substantially (0.83-1.96). Although the predictions of both phantoms are similar we advise the use of PMMA  +  PE slabs for both DM and DBT to harmonize dosimetry protocols and avoid any potential issues with the use of spacers with the PMMA phantoms.

  13. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    International Nuclear Information System (INIS)

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last decades the automatic exposure control (AEC) increased in complexity and became more sensitive to (local) differences in breast composition. The question is how well the AGD estimated using these simple dosimetry phantoms agrees with the average patient AGD. In this study the AGDs for both dosimetry phantoms and for patients have been evaluated for 5 different x-ray systems in DM and DBT modes. It was found that the ratios between patient and phantom AGD did not differ considerably using both dosimetry phantoms. These ratios averaged over all breast thicknesses were 1.14 and 1.15 for the PMMA and PMMA-PE dosimetry phantoms respectively in DM mode and 1.00 and 1.02 in the DBT mode. These ratios were deemed to be sufficiently close to unity to be suitable for dosimetry evaluation in quality control procedures. However care should be taken when comparing systems for DM and DBT since depending on the AEC operation, ratios for particular breast thicknesses may differ substantially (0.83–1.96). Although the predictions of both phantoms are similar we advise the use of PMMA  +  PE slabs for both DM and DBT to harmonize dosimetry protocols and avoid any potential issues with the use of spacers with the PMMA phantoms. (paper)

  14. Estimation of average glandular dose depending on the thickness of the breast; Estimativa da dose glandular media em funcao da espessura da mama

    Energy Technology Data Exchange (ETDEWEB)

    Real, Jessica V.; Luz, Renata M. da, E-mail: jessica.real@pucrs.br, E-mail: renata.luz@pucrs.br [Hospital Sao Lucas (HSL/PUCRS), Porto Alegre, RS (Brazil); Fröhlich, Bruna D.; Pertile, Alessandra S.; Silva, Ana Maria Marques da, E-mail: bruna.frohlich@acad.pucrs.br, E-mail: lessandra.pertile@acad.pucrs.br, E-mail: ana.marques@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil)

    2014-07-01

    Breast cancer is the most common type of cancer in women worldwide. Mammography is, to date, the most efficient method for detecting an abnormality in the patient's breast. It is a technique of imaging diagnostic that requires special care because radiographs without adequate quality may lead to a false diagnosis and lead to the need for a repeat examination, increasing the dose of radiation in the patient. This study aimed to evaluate the average glandular dose (AGD), depending on the breast thickness in patients undergoing routine tests, with a digital computer radiography processing system. Analyzed 30 exhibitions in patients aged (65 ± 12) years, in the right and left caudal skull projections, for breasts with thicknesses between 45 mm and 50 mm. The calculated value of the AGD for this track thickness was (1.600 ± 0.009) mGy. The performance of mammography quality control tests was satisfactory and the AGD values obtained for the chosen thickness range is acceptable, since the threshold achievable is 1.6 mGy and the acceptable is 2 mGy. In Brazil, it is only required the input dose calculation in skin for 45 mm breasts. However, the calculation of AGD is required for different thicknesses of the breast, to identify the best mammographic pattern aiming at better image quality at the lowest dose provided the patient.

  15. Estimation of the average glandular dose on a team of tomosynthesis

    International Nuclear Information System (INIS)

    Seeking to improve the information that gives us an image of mammography the manufacturers have implemented tomosynthesis. With this method of acquisition and reconstruction of image we went from having a 2D to a 3D image image, in such a way that it reduces or eliminates the effect of overlap of tissues. The estimate of the dose, which is always a fundamental parameter in the control of quality of radiology equipment, is more in the case of mammography by the radiosensitivity of this body and the frequency of their use. The objective of this work is the determination of the mean in a team glandular dose of with tomosynthesis mammography. (Author)

  16. Effect of anode/filter combination on average glandular dose in mammography

    OpenAIRE

    Michal Biegala; Teresa Jakubowska; Karolina Markowska

    2015-01-01

    A comparative analysis of the mean glandular doses was conducted in 100 female patients who underwent screening mammography in 2011 and 2013. Siemens Mammomat Novation with the application of the W/Rh anode/filter combination was used in 2011, whereas in 2013 anode/filter combination was Mo/Mo or Mo/Rh. The functioning of mammography was checked and the effectiveness of the automatic exposure control (AEC) system was verified by measuring compensation of changes in the phantom thickness and m...

  17. Estimates of Average Glandular Dose with Auto-modes of X-ray Exposures in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Izdihar Kamal

    2015-05-01

    Full Text Available Objectives: The aim of this research was to examine the average glandular dose (AGD of radiation among different breast compositions of glandular and adipose tissue with auto-modes of exposure factor selection in digital breast tomosynthesis. Methods: This experimental study was carried out in the National Cancer Society, Kuala Lumpur, Malaysia, between February 2012 and February 2013 using a tomosynthesis digital mammography X-ray machine. The entrance surface air kerma and the half-value layer were determined using a 100H thermoluminescent dosimeter on 50% glandular and 50% adipose tissue (50/50 and 20% glandular and 80% adipose tissue (20/80 commercially available breast phantoms (Computerized Imaging Reference Systems, Inc., Norfolk, Virginia, USA with auto-time, auto-filter and auto-kilovolt modes. Results: The lowest AGD for the 20/80 phantom with auto-time was 2.28 milliGray (mGy for two dimension (2D and 2.48 mGy for three dimensional (3D images. The lowest AGD for the 50/50 phantom with auto-time was 0.97 mGy for 2D and 1.0 mGy for 3D. Conclusion: The AGD values for both phantoms were lower against a high kilovolt peak and the use of auto-filter mode was more practical for quick acquisition while limiting the probability of operator error.

  18. Comparative evaluation of average glandular dose and image of digital mammography and film mammography in Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. Mammography is the best method for breast-cancer screening and is capable of reducing mortality rates To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. Digital mammography has been proposed as a substitute for film mammography given the benefits inherent to digital technology. The purpose of our study was to compare the technical performance of digital mammographic and screen-film mammography. A PMMA phantom with objects to simulate breast structures. For the screen/film (SF) technique the results showed that 54% mammography units did not achieve the minimum acceptable performance as far the image quality. Besides, 67% services showed inadequate performance in their processing systems, which had significant influence on the image quality. At the mean glandular dose only 44% of digital systems evaluated were compliant in all thicknesses of PMMA. The average glandular dose AGD was 90 % higher than in screen/film systems. (authors)

  19. Digital breast tomosynthesis and digital mammography: A comparison of figures of merit for various average glandular doses

    Science.gov (United States)

    Kim, Ye-seul; Park, Hye-Suk; Park, SuJin; Kim, Hee-Joung; Choi, Jae-Gu; Choi, Young-Wook; Park, Jun-Ho; Lee, Jae-Jun

    2013-05-01

    Previous studies on the application of tomosynthesis to breast imaging have demonstrated the potential of digital breast tomosynthesis (DBT). DBT can improve the specificity of digital mammography (DM) through improved marginal visibility of lesions and early breast cancer detection for women with dense breasts. To investigate possible improvements in the accuracy of lesion detection with DBT systems as compared to DM, we conducted a quantitative evaluation by using simulated lesions embedded in a breast phantom. A prototype DBT and dedicated DM system were used in this study. For the DBT system, the average glandular dose (AGD) was calculated using a formalism that was a simple extension of mammography dosimetry. The DBT and the DM images were acquired with average glandular doses (AGDs) ranging from 1 to 4 mGy. To analyze the results objectively, we calculated metrics for in-plane lesion visibility in the form of the contrast-to-noise ratio for the in-focus plane from the DBT reconstruction image and from the craniocaudal (CC) image from the DM system. The imaging performance of DBT was quantitatively compared with that of DM in terms of the figure of merit. Although the DM showed better results in terms of the contrast-to-noise ratio (CNR) of the mass due to the reduced overlapping of tissue and lesion, an increase in breast thickness of over 3 cm increased the CNR of the mass with the DBT system. For microcalcification detection, the DBT system showed significantly higher CNR than the DM system and gave better predictions of the microcalcification size. We compared the performances of the DM and the DBT systems for various AGDs and breast thicknesses. In conclusion, the results indicate that the DBT systems can play an important role in the detection of masses or microcalcifications without severe compression.

  20. Preliminary results of the average glandular dose to the breast with TLDS measure is computed as the conversion factors

    International Nuclear Information System (INIS)

    At mammography exams there is a risk of a breast cancer induced from the absorbed dose by the glandular tissue. According to the National Institute of Cancer, INCA, breast cancer is the second type most frequent in the world and the most common among women, therefore the necessity of monitoring the mean glandular dose, DG. Measuring methods of DG were established by some authors. Among the established methods the method of Dance is one of the most known. In this study was utilized a measurement method realized with TL dosimeters inserted in a breast tissue equivalent phantom, BTE, with 46% of glandularity and exposed using Mo/Mo and Mo/Rh target/filter combination and 28kV. To ensure this measurement method the results were compared with a calculation method, used by Dance, of DG from the measurement of incident air kerma, Ki, and conversion factors to consider mainly the beam quality, the compressed thickness and the glandularity of the breast. The results of the comparison of the DG measurement with the obtained dose by the method of Dance demonstrated that for the thickness of 4.0 and 6.0 cm the doses were consistent. For the thickness of 5.0 cm the difference was higher, indicating that the glandularity may influence, suggesting further investigation. (author)

  1. Preliminary results of the average glandular dose to the breast with TLDS measure is computed as the conversion factors; Resultados preliminares da dose glandular media na mama medida com TLDS e calculada atraves de fatores de conversao

    Energy Technology Data Exchange (ETDEWEB)

    Sardo, Luiz T.L.; Almeida, Claudio D.; Coutinho, Celia M.C., E-mail: ltsardo@yahoo.com.br, E-mail: claudio@ird.gov.br, E-mail: celia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    At mammography exams there is a risk of a breast cancer induced from the absorbed dose by the glandular tissue. According to the National Institute of Cancer, INCA, breast cancer is the second type most frequent in the world and the most common among women, therefore the necessity of monitoring the mean glandular dose, D{sub G}. Measuring methods of D{sub G} were established by some authors. Among the established methods the method of Dance is one of the most known. In this study was utilized a measurement method realized with TL dosimeters inserted in a breast tissue equivalent phantom, BTE, with 46% of glandularity and exposed using Mo/Mo and Mo/Rh target/filter combination and 28kV. To ensure this measurement method the results were compared with a calculation method, used by Dance, of D{sub G} from the measurement of incident air kerma, K{sub i}, and conversion factors to consider mainly the beam quality, the compressed thickness and the glandularity of the breast. The results of the comparison of the D{sub G} measurement with the obtained dose by the method of Dance demonstrated that for the thickness of 4.0 and 6.0 cm the doses were consistent. For the thickness of 5.0 cm the difference was higher, indicating that the glandularity may influence, suggesting further investigation. (author)

  2. Media glandular dose in mammography

    International Nuclear Information System (INIS)

    The objective of this work was to determine the media glandular dose of the patients group who most frequently are exposed at mammographic studies in the General Hospital of Zone No. 1 of IMSS in Zacatecas, later to compare this dose with the value that establishes the Mexican Official Standard and to know risk-benefit that a patient is exposed when it is realized studies of this nature. This with the purpose of to know if the patients who are realized this type of studies are exhibited to irradiations of unnecessary way. In order to obtain the media glandular dose, first it was choose the age group of feminine population that is predominant to this suffering. Of the classification of the age group it was determine the frequency of each thickness of mamma, and on the basis of the thickness of the compressed mamma the conditions were registered with it radiates the patient. When having the age and compressed mamma thickness of patient and the voltage, current, anode/filter that uses the mammography equipment for to radiate it was calculated the media glandular dose. The media glandular dose was calculated using two algorithms proposed in literature and thermoluminescent dosemeters. For the case of the thermoluminescent dosemeters were used two phantoms. In this study was detected that the limits, with that they radiate the patients who are exposed at mammographic studies it is by underneath of 3 mGy. Finally, it was detected that the Mexican Official Standard lacks of elements to offer radiological limits for the mammography area, because in this standard they are excluded the radiological limits for anode and filter of Mo/Rh and Rh/Rh. To know the dose applying these anodes and filters is of extreme importance because 85% of the population that is exposed to this studies type was radiated with anode and filter of Mo/Rh and Rh/Rh. (Author)

  3. Comparative evaluation of average glandular dose and breast cancer detection between single-view digital breast tomosynthesis (DBT) plus single-view digital mammography (DM) and two-view DM: correlation with breast thickness and density

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Ui; Chang, Jung Min; Bae, Min Sun; Lee, Su Hyun; Cho, Nariya; Seo, Mirinae; Kim, Won Hwa; Moon, Woo Kyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2015-01-15

    To compare the average glandular dose (AGD) and diagnostic performance of mediolateral oblique (MLO) digital breast tomosynthesis (DBT) plus cranio-caudal (CC) digital mammography (DM) with two-view DM, and to evaluate the correlation of AGD with breast thickness and density. MLO and CC DM and DBT images of both breasts were obtained in 149 subjects. AGDs of DBT and DM per exposure were recorded, and their correlation with breast thickness and density were evaluated. Paired data of MLO DBT plus CC DM and two-view DM were reviewed for presence of malignancy in a jack-knife alternative free-response ROC (JAFROC) method. The AGDs of both DBT and DM, and differences in AGD between DBT and DM (ΔAGD), were correlated with breast thickness and density. The average JAFROC figure of merit (FOM) was significantly higher on the combined technique than two-view DM (P = 0.005). In dense breasts, the FOM and sensitivity of the combined technique was higher than that of two-view DM (P = 0.003) with small ΔAGD. MLO DBT plus CC DM provided higher diagnostic performance than two-view DM in dense breasts with a small increase in AGD. (orig.)

  4. Media glandular dose in mammography;Dosis glandular media en mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Duran M, H. A.; Hernandez O, M.; Pinedo S, A.; Guerra M, J. A.; Gonzalez G, R.; Salas L, M. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada en Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Azorin N, J., E-mail: hduran20_1@hotmail.co [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, 09340 Mexico D. F. (Mexico)

    2009-10-15

    The objective of this work was to determine the media glandular dose of the patients group who most frequently are exposed at mammographic studies in the General Hospital of Zone No. 1 of IMSS in Zacatecas, later to compare this dose with the value that establishes the Mexican Official Standard and to know risk-benefit that a patient is exposed when it is realized studies of this nature. This with the purpose of to know if the patients who are realized this type of studies are exhibited to irradiations of unnecessary way. In order to obtain the media glandular dose, first it was choose the age group of feminine population that is predominant to this suffering. Of the classification of the age group it was determine the frequency of each thickness of mamma, and on the basis of the thickness of the compressed mamma the conditions were registered with it radiates the patient. When having the age and compressed mamma thickness of patient and the voltage, current, anode/filter that uses the mammography equipment for to radiate it was calculated the media glandular dose. The media glandular dose was calculated using two algorithms proposed in literature and thermoluminescent dosemeters. For the case of the thermoluminescent dosemeters were used two phantoms. In this study was detected that the limits, with that they radiate the patients who are exposed at mammographic studies it is by underneath of 3 mGy. Finally, it was detected that the Mexican Official Standard lacks of elements to offer radiological limits for the mammography area, because in this standard they are excluded the radiological limits for anode and filter of Mo/Rh and Rh/Rh. To know the dose applying these anodes and filters is of extreme importance because 85% of the population that is exposed to this studies type was radiated with anode and filter of Mo/Rh and Rh/Rh. (Author)

  5. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    International Nuclear Information System (INIS)

    Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgNhetero) and homogeneous (pDgNhomo) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgNhetero coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgNhomo coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgNhetero relative to pDgNhomo of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width in the superior and

  6. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Andrew M., E-mail: amhern@ucdavis.edu [Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States); Seibert, J. Anthony; Boone, John M. [Departments of Radiology and Biomedical Engineering, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States)

    2015-11-15

    Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the

  7. Mean glandular dose in a breast screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Galvan, H. A.; Perez-Badillo, M. P.; Villasenor, Y. [Instituto Nacional de Cancerologia, Av. San Fernando No. 22, Col Seccion XVI, Mexico, D. F., C. P. 14080 (Mexico)

    2012-10-23

    Breast density has an important role in early detection of breast cancer, because has been reported the strong association between breast density and invasive breast cancer risk. Mammography is the gold standard to early detection of breast cancer, despite of this require ionizing radiation that may increase radio-induced cancer risk. This maybe limited with a quality control programme of mammographic units, with the main goal of achieving high quality images with low radiation dose. International Atomic Energy Agency (IAEA) published in 2011 the {sup Q}uality assurance programme for digital mammography{sup ,} where glandular tissue quantity is an important parameter to compute mean glandular dose (MGD), which is necessary to reduce its associated risk. In this work we show the first results in our country applying this protocol and studying breast density in a small group. MGD complies with national and IAEA dose limits.

  8. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation

    International Nuclear Information System (INIS)

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed. (authors)

  9. Effect of the glandular composition on digital breast tomosynthesis image quality and dose optimisation.

    Science.gov (United States)

    Marques, T; Ribeiro, A; Di Maria, S; Belchior, A; Cardoso, J; Matela, N; Oliveira, N; Janeiro, L; Almeida, P; Vaz, P

    2015-07-01

    In the image quality assessment for digital breast tomosynthesis (DBT), a breast phantom with an average percentage of 50 % glandular tissue is seldom used, which may not be representative of the breast tissue composition of the women undergoing such examination. This work aims at studying the effect of the glandular composition of the breast on the image quality taking into consideration different sizes of lesions. Monte Carlo simulations were performed using the state-of-the-art computer program PENELOPE to validate the image acquisition system of the DBT equipment as well as to calculate the mean glandular dose for each projection image and for different breast compositions. The integrated PENELOPE imaging tool (PenEasy) was used to calculate, in mammography, for each clinical detection task the X-ray energy that maximises the figure of merit. All the 2D cranial-caudal projections for DBT were simulated and then underwent the reconstruction process applying the Simultaneous Algebraic Reconstruction Technique. Finally, through signal-to-noise ratio analysis, the image quality in DBT was assessed.

  10. Additional factors for the estimation of mean glandular breast dose using the UK mammography dosimetry protocol

    International Nuclear Information System (INIS)

    The UK and European protocols for mammographic dosimetry use conversion factors that relate incident air kerma to the mean glandular dose (MGD) within the breast. The conversion factors currently used were obtained by computer simulation of a model breast with a composition of 50% adipose and 50% glandular tissues by weight (50% glandularity). Relative conversion factors have been calculated which allow the extension of the protocols to breasts of varying glandularity and for a wider range of mammographic x-ray spectra. The data have also been extended to breasts of a compressed thickness of 11 cm. To facilitate the calculation of MGD in patient surveys, typical breast glandularities are tabulated for women in the age ranges 40-49 and 50-64 years, and for breasts in the thickness range 2-11 cm. In addition, tables of equivalent thickness of polymethyl methacrylate have been provided to allow the simulation for dosimetric purposes of typical breasts of various thicknesses. (author)

  11. Mammography equipment performance, image quality and mean glandular dose in Malta.

    Science.gov (United States)

    Borg, M; Badr, I; Royle, G J

    2013-09-01

    In this first Maltese national mammography survey, the effectiveness of direct digital (DR) mammography in breast cancer screening has been confirmed. Patient data were made available from three clinics out of the participating nine. A dose survey of mean glandular dose (MGD) calculated for 759 patients examined in the state-owned mammography facilities was performed. An MGD national diagnostic reference level was set at 1.87 mGy for patients with breast compression thicknesses (BCT) between 5.0 and 7.0 cm. This range was selected since patient data were retrieved from three clinics only and the results showed that other international BCT reference levels may be unsuitable for the Maltese population. In fact, the overall average BCT was 5.75 ± 1.4 cm. The survey results have shown that the technical standard of mammographic equipment in the Malta National Breast Screening Programme is on a par with other countries, including its Western European counterparts.

  12. Glandular dose in breast tomosynthesis examinations: Preliminary study with a sample of patients; Dosis glandular en examenes de tomosintesis de mama: estudio preliminar con una muestra de pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, M.; Chevalier, M.; Calzado, A.; Valverde, J.

    2013-07-01

    The aim of this study is to analyze the mean glandular dose administered to a group of patients with a tomography system (Selenia Dimensions) service installed on a large hospital in which routine tests are done and screening. (Author)

  13. Comparison of mean glandular dose values provided by a digital breast tomosynthesis system in Brazil

    International Nuclear Information System (INIS)

    Studies are needed to determine the radiation dose of patients that are undergoing Digital breast tomosynthesis (DBT) procedures. Mean glandular dose (DG) values were derived from the incident air kerma (Ki) measurements and tabulated conversion coefficients. Ki values were obtained through an ionization chamber positioned in a Hologic Selenia Dimensions system using appropriate exposure parameters. This work contributes to determine the reliable radiation dose received by the patients and compare DG values provided by this DBT system images. - Highlights: • Studies are needed to determine the dose of tomosynthesis (DBT) procedures. • Mean glandular dose (DG) results derived from the incident air kerma (Ki). • Ki values were obtained through an ionization chamber. • A DBT system was used with appropriate exposure parameters. • This work contributes to compare DG values provided by this DBT system images

  14. Monte Carlo simulation of glandular dose in a dedicated breast CT system

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao; WEI Long; ZHAO Wei; WANG Yan-Fang; SHU Hang; SUN Cui-Li; WEI Cun-Feng; CAO Da-Quan; QUE Jie-Min; SHI Rong-Jian

    2012-01-01

    A dedicated breast CT system (DBCT) is a new method for breast cancer detection proposed in recent years.In this paper,the glandular dose in the DBCT is simulated using the Monte Carlo method.The phantom shape is half ellipsoid,and a series of phantoms with different sizes,shapes and compositions were constructed. In order to optimize the spectra,monoenergy X-ray beams of 5-80 keV were used in simulation.The dose distribution of a breast phantom was studied:a higher energy beam generated more uniform distribution,and the outer parts got more dose than the inner parts.For polyenergtic spectra,four spectra of Al filters with different thicknesses were simulated,and the polyenergtic glandular dose was calculated as a spectral weighted combination of the monoenergetic dose.

  15. Glandular dose and image quality control in mammography facilities with computerized radiography systems

    International Nuclear Information System (INIS)

    Breast cancer is the most common cancer among women, and early detection is critical to its diagnosis and treatment. To date, the most effective method for early detection of breast cancer has been x-ray mammography for which the screen/film (SF) technique has been the gold standard. However, even though SF combinations have been improved and optimized over the years for breast imaging, there are some critical limitations, including a narrow exposure range, image artifacts, film processing problems, and inflexibility in image processing and film management. In recent years, digital mammography has been introduced in cancer screening programmes with the screen/film techniques gradually being phased out. Computed radiography (CR), also commonly known as photostimulable phosphor (PSP) imaging or storage phosphor, employs reusable imaging plates and associated hardware and software to acquire and to display digital projection radiographs. In this work, a protocol model was tested for performing image quality control and average glandular dose (AGD) evaluation in 19 institutions with computed radiography systems for mammography. The protocol was validated through tests at the Laboratorio de Radioprotecao Aplicada a Mamografia (LARAM) from the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN). The image quality visual evaluation of CDMAM phantom showed that 53% of the facilities were able to produce images of excellent quality. Furthermore, the automated evaluation of image quality, using the analyze software cdcom.exe, showed that 57% of the images were considered to be of good quality. The detector linearity test showed that the CR response is very linear, where 95% of facilities evaluated were considered to be compliant. For the image noise was found that only 20% of facilities are in agreement with the parameters established for this test. The average glandular doses, which patients may be getting to perform an examination, were below the action levels

  16. Monte Carlo simulation for the estimation of the glandular breast dose for a digital breast tomosynthesis system

    International Nuclear Information System (INIS)

    Digital breast tomosynthesis (DBT) is a screening and diagnostic modality that acquires images of the breast at multiple angles during a short scan. The Selenia Dimensions (Hologic, Bedford, Mass) DBT system can perform both full-field digital mammography and DBT. The system acquires 15 projections over a 15 deg. angular range (from -7.5 deg. to +7.5 deg.). An important factor in determining the optimal imaging technique for breast tomosynthesis is the radiation dose. In breast imaging, the radiation dose of concern is that deposited in the glandular tissue of the breast because this is the tissue that has a risk of developing cancer. The concept of the normalised mean glandular dose (DgN) has been introduced as the metric for the dose in breast imaging. The DgN is difficult to measure. The Monte Carlo techniques offer an alternative method for a realistic estimation of the radiation dose. The purpose of this work was to use the Monte Carlo code MCNPX technique to generate monoenergetic glandular dose data for estimating the breast tissue dose in tomosynthesis for arbitrary spectra as well as to observe the deposited radiation dose by projection on the glandular portion of the breast in a Selenia Dimensions DBT system. A Monte Carlo simulation of the system was developed to compute the DgN in a craniocaudal view. Monoenergetic X-ray beams from 10 to 49 keV in 1-keV increments were used. The simulation utilised the assumption of a homogeneous breast composition and three compositions (0 % glandular, 50 % glandular and 100 % glandular). The glandular and adipose tissue compositions were specified according ICRU Report 44. A skin layer of 4 mm was assumed to encapsulate the breast on all surfaces. The breast size was varied using the chest wall-to-nipple distance (CND) and compressed breast thickness (t). In this work, the authors assumed a CND of 5 cm and the thicknesses ranged from 2 to 8 cm, in steps of 2 cm. The fractional energy absorption increases (up to 44

  17. Comportamento da dose glandular versus contraste do objeto em mamografia: determinação de formalismo semi-empírico para diferentes combinações alvo-filtro Behavior of subject contrast versus glandular dose in mammography: determination of a semi-empirical formalism for different target-filter combinations

    Directory of Open Access Journals (Sweden)

    Gabriela Hoff

    2006-06-01

    . Average glandular dose was determined with a BR12 simulator (50% fat tissue and 50% glandular tissue of different thicknesses (4 cm and 8 cm. Energies in the range of 24 to 34 kVp and Kodak MinR 2000 films were used. RESULTS: Results have evidenced data on subject contrast data, glandular dose and exposure time for different thicknesses of additional filters and different kVp values. These data have indicated an increase both in values of subject contrast and exposure time when filters thickness is increased. The glandular dose has presented a different behavior tendency for each case analyzed. Equations were defined to allow us to estimate subject contrast, glandular dose and exposure time for the cases studied. CONCLUSION: The results have made possible to define equations to assist with the evaluation of subject contrast and glandular dose behavior in simulators with 4 cm and 8 cm thicknesses and for Rh and Mo additional filters. In this way, it is possible to estimate the figure of merit (subject contrast/glandular dose ratio to assist in the risk-benefit analysis of the cases studied.

  18. The Study of Mean Glandular Dose in Mammography in Yazd and the Factors Affecting It

    Directory of Open Access Journals (Sweden)

    F. Bouzarjomehri

    2006-08-01

    Full Text Available Backgrounds/Objective: The objective of this study was to determine the mean glandular dose (MGD resulting from mammography examinations in Yazd, southeastern Iran and to identify the factors affecting it. Patients and Methods: This survey was conducted during May to December 2005 to estimate the MGD for women undergoing mammography and to report the distribution of dose, com-pressed breast thickness, glandular tissue content, and mammography technique used. The clinical data were collected from 946 mammograms taken from 246 women who were referred to four mammography centers. The mammography instruments in these centers were four modern units with a molybdenum anode and either molybdenum or rhodium filter. The exposure conditions of each mammogram were recorded. The breast glandular content of each mammogram was estimated by a radiologist. The MGD was calculated based on measuring the normalized entrance skin dose (ESD in air, Half Value Layer (HVL, kVp, mAs, breast thickness and glandular content. HVL, kVp and ESD were measured by a solid-state detector. The analytical method of Sobol et al. was used for calculation of MGD. Results: The mean±SD MGD per film was 1.2±0.6 mGy for craniocaudal and 1.63±0.9 mGy for mediolateral oblique views. The mean±SD MGD per woman was 5.57±3.1 mGy. A positive correlation was found between the beam HVL with MGD (r=0.38 and the breast thickness with MGD (r=0.5. Conclusion: The mean±SD MGD per film of 1.42±0.8 mGy in present study was lower than most of similar reports. However, the mean MGD per woman was higher than that in other studies.

  19. Results of a 2011 national questionnaire for investigation of mean glandular dose from mammography in Japan

    International Nuclear Information System (INIS)

    Diagnostic reference levels (DRLs) for mammography have yet to be created in Japan. A national questionnaire investigation into radiographic conditions in Japan was carried out for the purpose of creating DRLs. Items investigated included the following: tube voltage; tube current; current–time product; source–image distance; craniocaudal view; automatic exposure control (AEC) settings; name of mammography unit; image receptor system (computed radiography (CR), flat panel detector (FPD), or film/screen (F/S)); and supported or unsupported monitor diagnosis (including monitor resolution). Estimation of the mean glandular dose (MGD) for mammography was performed and compared with previous investigations. The MGD was 1.58(0.48) mGy, which did not significantly differ from a 2007 investigation. In relation to image receptors, although no difference in average MGD values was observed between CR and FPD systems, F/S systems had a significantly decreased value compared to both CR and FPDs. Concerning digital systems (FPDs), the MGD value of the direct conversion system was significantly higher than the indirect conversion system. No significant difference in MGD value was evident concerning type of monitor diagnosis for either the CR or the FPD digital systems; however, hard copies were used more often in CR. No significant difference in the MGD value was found in relation to monitor resolution. This report suggests ways to lower the doses patients undergoing mammography receive in Japan, and serves as reference data for 4.2 cm compressed breast tissue of 50% composition DRLs. Furthermore, our findings suggest that further optimisation of FPD settings can promote a reduction in the MGD value. (paper)

  20. SU-E-I-04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pineda, E; Ruiz-Trejo, C; E, Brandan M [Instituto de Fisica UNAM, Mexico City, DF (Mexico)

    2014-06-01

    Purpose: To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert. Methods: The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD-100 chips, some under Al foils, to determine air kerma and half-value-layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1). Results: MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full-field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR). Conclusion: The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography.

  1. SU-E-I-04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality

    International Nuclear Information System (INIS)

    Purpose: To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert. Methods: The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD-100 chips, some under Al foils, to determine air kerma and half-value-layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1). Results: MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full-field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR). Conclusion: The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography

  2. A Quality Assurance programme in mammography and an evaluation of the mean glandular dose

    International Nuclear Information System (INIS)

    The use of X-ray in medicine for diagnosis represents the largest man-made sources of public exposure to ionizing radiation. Therefore a reduction of medical exposure is desired without reduction of the diagnostic capability. Dose and image quality are essential component of a Quality Assurance (QA) programme in mammography where the characteristic of diagnostic signs, represented by microcalcifications and low contrast structures, and the radiosensitivity of the glandular tissue of the breast stress the need of QA programme. The paper describes QA procedures in mammography and reports the results obtained in more than 120 periodic tests, performed on 63 mammographic units of 41 centers. Moreover individual evaluation of entrance exposure are presented for 340 patients. The experimental data permits to evaluate the mean grandular absorbed dose in the single exams using different procedures based on Monte Carlo simulations. (author)

  3. Normalized mean glandular dose computation from mammography using GATE: a validation study

    Science.gov (United States)

    Myronakis, Marios E.; Zvelebil, Marketa; Darambara, Dimitra G.

    2013-04-01

    Mean glandular dose (MGD) is the figure of merit to assess breast dose after a mammographic acquisition. The use of normalized MGD obtained from Monte Carlo computations with measured incident air kerma determines the MGD delivered to patients. The Geant4 Application for Tomographic Emission (GATE) toolkit is a modern Monte Carlo application specifically designed for medical imaging systems modelling. Although there is an increasing number of publications using GATE worldwide for a wide range of medical imaging and therapeutic applications, there is currently no means to obtain normalized MGD. In this work, the GATE toolkit is extended, through the development of two new modules, to provide normalized MGD information for compressed breast phantoms based on simple geometries. The normalized MGD values were validated against published work and provided results at half value layers lower than 0.3 and greater than 0.6 mmAl. In addition, the skin thickness and composition were considered. Normalized MGD was computed after substitution of the adipose layer surrounding the standard breast phantom with skin tissue and the relative difference is reported. Spectrum generation was facilitated by further development of previously published work by other authors. Validation of the new GATE extension showed good agreement with published data and can be used to assess breast dose from mammographic as well as more complex x-ray imaging techniques. Changing skin thickness and composition revealed substantial changes in normalized MGD specifically for compressed breast thickness different than 5 cm and a possible revision of the structure of the standard breast model may be necessary.

  4. Mean glandular doses for women undergoing mammographic breast screening in Oyo state, Nigeria

    International Nuclear Information System (INIS)

    In this work, thermoluminescent dosimeters have been used to measure entrance surface doses (ESDs) of patients undergoing mammographic screening at the University College Hospital, Ibadan, Oyo state. The mean glandular doses (MGDs) were also calculated using the measured ESDs. The results showed that the ESDs ranged from 0.26 mGy to 21.26 mGy for the mediolateral oblique (MLO) views and 0.08 mGy to 5.36 mGy for the craniocaudal (CC) views. The calculated MGD ranged from 0.07 mGy to 3.57 mGy for the MLO views and 0.02 mGy to 0.98 mGy for the CC views. The possible reasons for the large variations in the individual ESD values and MGD values for both views are discussed using patients' data, equipment specific data and the technical parameters used for the examinations. Comparison showed that the mean ESD values and MGD values reported in this work are below published values. The mean of the calculated MGD values is also found to be lower than the recommended guidance level of 3.0 mGy when using grid. 92.5% of the patients had MGD values that are less than 2.5 mGy, hence a national reference MGD value of 2.5 mGy is proposed for Nigeria. Implementation of a dose reduction program in mammographic screening is also suggested because of the observed large variations in patients MGD values.

  5. Validation of mean glandular dose values provided by a digital breast tomosynthesis system in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Beraldo O, B.; Paixao, L.; Donato da S, S. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Post-graduation in Sciences and Technology of Radiations Minerals and Materials, Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte (Brazil); Araujo T, M. H. [Dr Maria Helena Araujo Teixeira Clinic, Guajajaras 40, 30180-100 Belo Horizonte (Brazil); Nogueira, M. S., E-mail: bbo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte (Brazil)

    2014-08-15

    Digital breast tomosynthesis (DBT) is an emerging imaging modality that provides quasi-three-dimensional structural information of the breast and has strong promise to improve the differentiation of normal tissue and suspicious masses reducing the tissue overlaps. DBT images are reconstructed from a sequence of low-dose X-ray projections of the breast acquired at a small number of angles over a limited angular range. The Ho logic Selen ia Dimensions system is equipped with an amorphous Selenium (a-Se) detector layer of 250 μm thickness and a 70 μm pixel pitch. Studies are needed to determine the radiation dose of patients that are undergoing this emerging procedure to compare with the results obtained in DBT images. The mean glandular dose (D{sub G}) is the dosimetric quantity used in quality control of the mammographic systems. The aim of this work is to validate D{sub G} values for different breast thicknesses provided by a Ho logic Selen ia Dimensions system using a DBT mode in comparison with the same results obtained by a calibrated 90 X 5-6M-model Radcal ionization chamber. D{sub G} values were derived from the incident air kerma (K{sub i}) measurements and tabulated conversion coefficients that are dependent on the half value layer (HVL) of the X-ray spectrum. Voltage and tube loading values were recorded in irradiations using W/Al anode/filter combination, automatic exposure control mode and polymethyl methacrylate (PMMA) slabs which simulate different breast thicknesses. For K{sub i} measurements, the ionization chamber was positioned at 655 mm from the focus and the same radiographic technique values were selected with the manual mode. D{sub G} values for a complete procedure ranged from 0.9 ± 0.1 to 3.7 ± 0.4 mGy. The results for different breast thicknesses are in accordance with values obtained by DBT images and with acceptable levels established by the Commission of the European Communities (Cec) and the International Atomic Energy Agency (IAEA

  6. Estimation of mean-glandular dose from monitoring breast entrance skin air kerma using a high sensitivity metal oxide semiconductor field effect transistor (MOSFET) dosimeter system in mammography.

    Science.gov (United States)

    Dong, S L; Chu, T C; Lee, J S; Lan, G Y; Wu, T H; Yeh, Y H; Hwang, J J

    2002-12-01

    Estimation of mean-glandular dose (MGD) has been investigated in recent years due to the potential risks of radiation-induced carcinogenesis associated with the mammographic examination for diagnostic radiology. In this study, a new technique for immediate readout of breast entrance skin air kerma (BESAK) using high sensitivity MOSFET dosimeter after mammographic projection was introduced and a formula for the prediction of tube output with exposure records was developed. A series of appropriate conversion factors was applied to the MGD determination from the BESAK. The study results showed that signal response of the high sensitivity MOSFET exhibited excellent linearity within mammographic dose ranges, and that the energy dependence was less than 3% for each anode/filter combination at the tube potentials 25-30 kV. Good agreement was observed between the BESAK and the tube exposure output measurement for breasts thicker than 30 mm. In addition, the air kerma estimated from our prediction formula provided sufficient accuracy for thinner breasts. The average MGD from 120 Asian females was 1.5 mGy, comparable to other studies. Our results suggest that the high sensitivity MOSFET dosimeter system is a good candidate for immediately readout of BESAK after mammographic procedures.

  7. Model Averaging Software for Dichotomous Dose Response Risk Estimation

    Directory of Open Access Journals (Sweden)

    Matthew W. Wheeler

    2008-02-01

    Full Text Available Model averaging has been shown to be a useful method for incorporating model uncertainty in quantitative risk estimation. In certain circumstances this technique is computationally complex, requiring sophisticated software to carry out the computation. We introduce software that implements model averaging for risk assessment based upon dichotomous dose-response data. This software, which we call Model Averaging for Dichotomous Response Benchmark Dose (MADr-BMD, fits the quantal response models, which are also used in the US Environmental Protection Agency benchmark dose software suite, and generates a model-averaged dose response model to generate benchmark dose and benchmark dose lower bound estimates. The software fulfills a need for risk assessors, allowing them to go beyond one single model in their risk assessments based on quantal data by focusing on a set of models that describes the experimental data.

  8. Construction of average adult Japanese voxel phantoms for dose assessment

    International Nuclear Information System (INIS)

    The International Commission on Radiological Protection (ICRP) adopted the adult reference voxel phantoms based on the physiological and anatomical reference data of Caucasian on October, 2007. The organs and tissues of these phantoms were segmented on the basis of ICRP Publication 103. In future, the dose coefficients for internal dose and dose conversion coefficients for external dose calculated using the adult reference voxel phantoms will be widely used for the radiation protection fields. On the other hand, the body sizes and organ masses of adult Japanese are generally smaller than those of adult Caucasian. In addition, there are some cases that the anatomical characteristics such as body sizes, organ masses and postures of subjects influence the organ doses in dose assessment for medical treatments and radiation accident. Therefore, it was needed to use human phantoms with average anatomical characteristics of Japanese. The authors constructed the averaged adult Japanese male and female voxel phantoms by modifying the previously developed high-resolution adult male (JM) and female (JF) voxel phantoms. It has been modified in the following three aspects: (1) The heights and weights were agreed with the Japanese averages; (2) The masses of organs and tissues were adjusted to the Japanese averages within 10%; (3) The organs and tissues, which were newly added for evaluation of the effective dose in ICRP Publication 103, were modeled. In this study, the organ masses, distances between organs, specific absorbed fractions (SAFs) and dose conversion coefficients of these phantoms were compared with those evaluated using the ICRP adult reference voxel phantoms. This report provides valuable information on the anatomical and dosimetric characteristics of the averaged adult Japanese male and female voxel phantoms developed as reference phantoms of adult Japanese. (author)

  9. Evaluation of the influence of parameters that determine the mean glandular dose in mammography using different detectors; Evaluacion de la influencia de los parametros que determinan la dosis glandular media en Mamografia utilizando diferentes detectores

    Energy Technology Data Exchange (ETDEWEB)

    Costa, K.; Nogueira, M. S., E-mail: katicostabh@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear, Pos-graduacao em Ciencias e Tecnologia das Radiacoes, Minerais e Materiais / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Mammography is a test used for early detection of breast cancer. The mean glandular dose (MGD) is dosimetric greatness accepted as indicative of carcinogenic risk induced by ionizing radiation in the breasts of women undergoing mammography exams. MGD value is estimated from the incident air kerma (k i), associated with conversion factors which depend on the half-value layer (HVL), the breast composition and thickness compressed breast. This study aims to evaluate the influence of the parameters used to determine the MGD using different measurement detectors. Measurements were performed on a Siemens Mammomat Model 300 Nova mammography equipment; this has the combinations Anode/Filter of Mo/Mo, Mo/Rh and W/Rh. Detectors used were the ionization chamber Model 10X6-6M manufactured by Radcal Co., two solid-state detectors, one Model AGMS-M manufactured by Radcal Co. and other Model Xi Mammo manufactured by UNFORS. The detectors measures were compared and the MGD value was estimated; differences between measurements and the reference values were higher in HVL and k i parameters. The results are displayed according to other published works. (Author)

  10. A comparison of mean glandular dose diagnostic reference levels within the all-digital Irish National Breast Screening Programme and the Irish Symptomatic Breast Services.

    Science.gov (United States)

    O'Leary, Desiree; Rainford, Louise

    2013-03-01

    Data on image quality, compression and radiation dose were collected from symptomatic breast units within the Republic of Ireland. Quantitative and qualitative data were analysed using SPSS. Recommendations of mean glandular dose (MGD) diagnostic reference levels were made at various levels for film-screen and full field digital mammography units to match levels published worldwide. MGDs received by symptomatic breast patients within Ireland are higher than those received in the all-digital Irish Breast Screening service; 55-65 mm breast: 1.75 mGy (screening) vs. 2.4 mGy (symptomatic) at the 95th percentile; various reasons are proposed for the differences. MGDs achieved in the screening service may be lower because of the exacting requirements for radiographer training, characteristics of the patients and equipment quality assurance levels. More precise imaging guidelines, standards and training of symptomatic radiographers performing mammography are suggested to remediate MGDs delivered to the breasts of Irish women attending the symptomatic breast services. PMID:22740646

  11. Mean glandular dose estimation using MCNPX for a digital breast tomosynthesis system with tungsten/aluminum and tungsten/aluminum+silver x-ray anode-filter combinations

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Andy K. W.; Darambara, Dimitra G.; Stewart, Alexander; Gunn, Spencer; Bullard, Edward [Joint Department of Physics, Institute of Cancer Research and The Royal Marsden Hospital, Fulham Road, London SW3 6JJ (United Kingdom); Dexela Ltd., 1 Water Lane, Camden Town, London NW1 8NZ (United Kingdom)

    2008-12-15

    Breast cancer screening with x-ray mammography, using one or two projection images of the breast, is an indispensible tool in the early detection of breast cancer in women. Digital breast tomosynthesis (DBT) is a 3D imaging technique that promises higher sensitivity and specificity in breast cancer screening at a similar radiation dose to conventional two-view screening mammography. In DBT a 3D volume is reconstructed with anisotropic voxels from a limited number of x-ray projection images acquired over a limited angle. Although the benefit of early cancer detection through screening mammography outweighs the potential risks associated with radiation, the radiation dosage to women in terms of mean glandular dose (MGD) is carefully monitored. This work studies the MGD arising from a prototype DBT system under various parameters. Two anode/filter combinations (W/Al and W/Al+Ag) were investigated; the tube potential ranges from 20 to 50 kVp; and the breast size varied between 4 and 10 cm chest wall-to-nipple distance and between 3 and 7 cm compressed breast thickness. The dosimetric effect of breast positioning with respect to the imaging detector was also reviewed. It was found that the position of the breast can affect the MGD by as much as 5% to 13% depending on the breast size.

  12. Statistical strategies for averaging EC50 from multiple dose-response experiments.

    Science.gov (United States)

    Jiang, Xiaoqi; Kopp-Schneider, Annette

    2015-11-01

    In most dose-response studies, repeated experiments are conducted to determine the EC50 value for a chemical, requiring averaging EC50 estimates from a series of experiments. Two statistical strategies, the mixed-effect modeling and the meta-analysis approach, can be applied to estimate average behavior of EC50 values over all experiments by considering the variabilities within and among experiments. We investigated these two strategies in two common cases of multiple dose-response experiments in (a) complete and explicit dose-response relationships are observed in all experiments and in (b) only in a subset of experiments. In case (a), the meta-analysis strategy is a simple and robust method to average EC50 estimates. In case (b), all experimental data sets can be first screened using the dose-response screening plot, which allows visualization and comparison of multiple dose-response experimental results. As long as more than three experiments provide information about complete dose-response relationships, the experiments that cover incomplete relationships can be excluded from the meta-analysis strategy of averaging EC50 estimates. If there are only two experiments containing complete dose-response information, the mixed-effects model approach is suggested. We subsequently provided a web application for non-statisticians to implement the proposed meta-analysis strategy of averaging EC50 estimates from multiple dose-response experiments.

  13. Evaluation of annual average equivalent dose of workers for nuclear medicine facilities in the Northeast Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Renata F.; Silva Neto, Jose Almeida; Antonio Filho, Joao, E-mail: jaf@ufpe.br [Universidade Federal de Pernambuco (UFPE/DEN), Departamento de Energia Nuclear, Recife, PE (Brazil); Santos, Luiz A.P., E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    Nuclear Medicine (NM) is a radiation technique normally used to make therapeutic treatments or diagnosis. In this technique a small quantity of radioactive material combined with drugs is used to have the diagnostic images. Any activity involving ionizing radiation should be justified and it must have its working procedures to be optimized. The purpose of this paper is show the importance of optimization of the radiation protection systems and determines an optimal dose for occupational people in nuclear medicine. Such an optimization aims to avoid any possible contamination or accidents, and reduce costs of protection. The optimization for a service which manipulates ionizing radiation can be done using different techniques, and among other, we can mention the technique of expanded cost-benefit analysis. The data collection was divided into the equivalent dose annual average and the equivalent dose average in period. The database for this study was a survey of received doses from 87 occupational people of 10 nuclear medicine facilities in the northeast Brazil and it was made in a period of 13 years (1979-1991). The results show that the equivalent dose average in the period H was 2.39 mSv. Actually, since 1992 the analysis is in progress and it shows that equivalent dose annual average could reduce even more if procedures of work are followed correctly. (author)

  14. Radiation doses to screened women in the Norwegian Breast Cancer Screening Program in 2005 and 2006

    International Nuclear Information System (INIS)

    The radiographers report exposure data for approximately 50 women annually to the Norwegian Radiation Protection Authority. Based on reported data from all laboratories involved in the Norwegian Breast Cancer Screening Program average glandular dose (AGD) to the screened. (author)

  15. Individual doses for women undergoing screening mammography examinations in Poland in 2007

    International Nuclear Information System (INIS)

    Exposure doses to women undergoing screening mammography examinations should be kept as low as reasonably achievable, but they should ensure high enough image quality for adequate diagnosis. The aim of this study was to estimate the radiation risk according to the 'European guidelines for quality assurance in breast cancer screening and diagnosis', fourth edition (European Commission 2006). Materials for this study were obtained from data from 250 screening mammography facilities in Poland. For every mammography facility, a standard average glandular dose for routine exposure was calculated. Furthermore, average glandular doses for individual mammography examinations obtained according to the methods proposed by Dance et al (2000 Phys. Med. Biol. 45 3225–40) were calculated. The average glandular doses determined for 250 mammography facilities ranged from 0.12 to 14.56 mGy (the mean values ranged from 0.62 to 4.53 mGy). Only for 39 mammography facilities were all exposures found to be below the acceptable level for an average glandular dose, and for only 18 mammography facilities did no exposures exceed the achievable levels for an average glandular dose. Average glandular doses to women undergoing mammography screening attained unnecessary high values, and they were found to depend on the technical parameters of the mammography equipment and maintenance of mammography units by personnel in various mammography facilities.

  16. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, Florida (United States); Wang, Shyh-Jen [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Chen, Chih-Hao [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Yang, Bang-Hung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Wu, Nien-Yun [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.t [Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan (China)

    2010-07-21

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional {sup 68}Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  17. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    International Nuclear Information System (INIS)

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  18. Low-dose interpolated average CT for attenuation correction in cardiac PET/CT

    Science.gov (United States)

    Wu, Tung-Hsin; Zhang, Geoffrey; Wang, Shyh-Jen; Chen, Chih-Hao; Yang, Bang-Hung; Wu, Nien-Yun; Huang, Tzung-Chi

    2010-07-01

    Because of the advantages in the use of high photon flux and thus the short scan times of CT imaging, the traditional 68Ge scans for positron emission tomography (PET) image attenuation correction have been replaced by CT scans in the modern PET/CT technology. The combination of fast CT scan and slow PET scan often causes image misalignment between the PET and CT images due to respiration motion. Use of the average CT derived from cine CT images is reported to reduce such misalignment. However, the radiation dose to patients is higher with cine CT scans. This study introduces a method that uses breath-hold CT images and their interpolations to generate the average CT for PET image attenuation correction. Breath-hold CT sets are taken at end-inspiration and end-expiration. Deformable image registration is applied to generate a voxel-to-voxel motion matrix between the two CT sets. The motion is equally divided into 5 steps from inspiration to expiration and 5 steps from expiration to inspiration, generating a total of 8 phases of interpolated CT sets. An average CT image is generated from all the 10 phase CT images, including original inhale/exhale CT and 8 interpolated CT sets. Quantitative comparison shows that the reduction of image misalignment artifacts using the average CT from the interpolation technique for PET attenuation correction is at a similar level as that using cine average CT, while the dose to the patient from the CT scans is reduced significantly. The interpolated average CT method hence provides a low dose alternative to cine CT scans for PET attenuation correction.

  19. Verification of the method of average angular response for dose measurement on different detectors

    International Nuclear Information System (INIS)

    At present most radiation dose meters have serious problems on aspects of energy response and angular response. In order to improve the accuracy of dose measurements, a method of average angular response has been proposed. The method can not only correct the energy response, but also the angular response. This method has been verified on NaI(Tl)(50 mm× 50 mm) scintillation detectors, but has not been proved on other types and sizes of detectors, In this paper the method is also verified for LaBr3(Ce) scintillation detectors and HPGe detector To apply the method, first of all, five detectors are simulated by Geant4 and average angular response values are calculated. Then experiments are performed to get the count rates of full energy peak by standard point source of 137Cs, 60Co and 152Eu. After that the dose values of five detectors are calculated with the method of average angular response. Finally experimental results are got. These results are divided into two groups to analyze the impact of detectors of various types and sizes. The result of the first group shows that the method is appropriate for different types of detector to measure dose, with deviations of less than 5% compared with theoretical values. Moreover, when the detector's energy resolution is better and the count rate of the full energy peak is calculated more precisely, the measured dose can be obtained more precisely. At the same time, the result of the second group illustrates that the method is also suited for different sizes of detectors, with deviations of less than 8% compared with theoretical values

  20. Analysis of terrestrial natural radionuclides in soil samples and assessment of average effective dose

    International Nuclear Information System (INIS)

    Radionuclides that are present in soil significantly affect terrestrial gamma radiation levels which in turn can be used for the assessment of terrestrial gamma dose rates. Natural radioactivity analysis has been done for the soil samples collected from different villages/towns of Hoshiarpur district of Punjab, India. The measurements have been carried out using HPGe detector based on high-resolution gamma spectrometry system. The calculated activity concentration values for terrestrial gamma viz. 238U, 232Th and 40K have been found to vary from 8.89 to 56.71 Bq kg-1, from 137.32 to 334.47 Bq kg-1 and from 823.62 to 1064.97 Bq kg-1, respectively. The total average absorbed dose rate in the study areas is 185.32 nGyh-1. The calculated value of average radium equivalent activity (401.13 Bq kg-1) exceeds the permissible limit (370 Bqkg-1) recommended by Organization for Economic Corporation and Development (OECD). The calculated average value of external hazard index (Hex) is 1.097. The calculated values of Indoor and Outdoor annual effective doses vary from 0.61 to 1.28 mSv and from 0.15 to 0.32 mSv, respectively. A positive correlation (R2 = 0.71) has also been observed for concentration of 232Th and 40K. (author)

  1. The effect of breast composition on absorbed dose and image contrast

    International Nuclear Information System (INIS)

    We have studied the effect of breast composition on the average whole breast dose, average glandular dose, and image contrast in mammography, using both computational and experimental methods. Three glandular/adipose compositions were considered: 30/70, 50/50, and 70/30 by weight, for both 3- and 5-cm breast thickness. Absorbed dose was found to increase with greater glandular content and this increase is more pronounced for thick breasts and softer beams. For typical screen-film x-ray beams, the average dose to a highly glandular breast is nearly twice the dose to a highly adipose breast and the average glandular dose about 40% higher. Dose was reduced when higher energy beams were employed. The use of a grid increased the dose by a factor of 2.0 to 2.6. Finally, the measured image contrast decreases with increasing breast glandularity, to a greater extent in small breasts and when low energy beams were employed

  2. New method for generating breast models featuring glandular tissue spatial distribution

    Science.gov (United States)

    Paixão, L.; Oliveira, B. B.; Oliveira, M. A.; Teixeira, M. H. A.; Fonseca, T. C. F.; Nogueira, M. S.

    2016-02-01

    Mammography is the main radiographic technique used for breast imaging. A major concern with mammographic imaging is the risk of radiation-induced breast cancer due to the high sensitivity of breast tissue. The mean glandular dose (DG) is the dosimetric quantity widely accepted to characterize the risk of radiation induced cancer. Previous studies have concluded that DG depends not only on the breast glandular content but also on the spatial distribution of glandular tissue within the breast. In this work, a new method for generating computational breast models featuring skin composition and glandular tissue distribution from patients undergoing digital mammography is proposed. Such models allow a more accurate way of calculating individualized breast glandular doses taking into consideration the glandular tissue fraction. Sixteen breast models of four patients with different glandularity breasts were simulated and the results were compared with those obtained from recommended DG conversion factors. The results show that the internationally recommended conversion factors may be overestimating the mean glandular dose to less dense breasts and underestimating the mean glandular dose for denser breasts. The methodology described in this work constitutes a powerful tool for breast dosimetry, especially for risk studies.

  3. Dosimetric implications of age related glandular changes in screening mammography

    Science.gov (United States)

    Beckett, J. R.; Kotre, C. J.

    2000-03-01

    The UK National Health Service Breast Screening Programme is currently organized to routinely screen women between the ages of 50 and 64, with screening for older women available on request. The lower end of this age range closely matches the median age for the menopause (51 years), during which significant changes in the composition of the breast are known to occur. In order to quantify the dosimetric effect of these changes, radiographic factors and compressed breast thickness data for a cohort of 1258 women aged between 35 and 79 undergoing breast screening mammography have been used to derive estimates of breast glandularity and mean glandular dose (MGD), and examine their variation with age. The variation of mean radiographic exposure factors with age is also investigated. The presence of a significant number of age trial women within the cohort allowed an extended age range to be studied. Estimates of MGD including corrections for breast glandularity based on compressed breast thickness only, compressed breast thickness and age and for each individual woman are compared with the MGD based on the conventional assumption of a 50:50 adipose/glandular composition. It has been found that the use of the conventional 50:50 assumption leads to overestimates of MGD of up to 13% over the age range considered. By using compressed breast thickness to estimate breast glandularity, this error range can be reduced to 8%, whilst age and compressed breast thickness based glandularity estimates result in an error range of 1%.

  4. Morphological differentiation of non-glandular and glandular trichomes on Marrubium vulgare L.

    Directory of Open Access Journals (Sweden)

    Marta Dmitruk

    2014-04-01

    four-celled head and a unicellular stalk. The length of these trichomes is on average 26.32 μm and the diameter of the head is 20.32 μm. Moreover, we observed two types of non-glandular trichomes: multicellular uniserrate and multicellular branched. The length of the non-glandular trichomes is between 60.69 μm and 1130.3 μm.

  5. Biosphere Dose Conversion Factors for Reasonably Maximally Exposed Individual and Average Member of Critical Group

    Energy Technology Data Exchange (ETDEWEB)

    K. Montague

    2000-02-23

    The purpose of this calculation is to develop additional Biosphere Dose Conversion Factors (BDCFs) for a reasonably maximally exposed individual (RMEI) for the periods 10,000 years and 1,000,000 years after the repository closure. In addition, Biosphere Dose Conversion Factors for the average member of a critical group are calculated for those additional radionuclides postulated to reach the environment during the period after 10,000 years and up to 1,000,000 years. After the permanent closure of the repository, the engineered systems within the repository will eventually lose their abilities to contain radionuclide inventory, and the radionuclides will migrate through the geosphere and eventually enter the local water table moving toward inhabited areas. The primary release scenario is a groundwater well used for drinking water supply and irrigation, and this calculation takes these postulated releases and follows them through various pathways until they result in a dose to either a member of critical group or a reasonably maximally exposed individual. The pathways considered in this calculation include inhalation, ingestion, and direct exposure.

  6. A unified framework for benchmark dose estimation applied to mixed models and model averaging

    DEFF Research Database (Denmark)

    Ritz, Christian; Gerhard, Daniel; Hothorn, Ludwig A.

    2013-01-01

    This article develops a framework for benchmark dose estimation that allows intrinsically nonlinear dose-response models to be used for continuous data in much the same way as is already possible for quantal data. This means that the same dose-response model equations may be applied to both...

  7. Assessment of the mean glandular dose using LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu TL detectors in mammography radiation fields

    Science.gov (United States)

    Fartaria, M. J.; Reis, C.; Pereira, J.; Pereira, M. F.; Cardoso, J. V.; Santos, L. M.; Oliveira, C.; Holovey, V.; Pascoal, A.; Alves, J. G.

    2016-09-01

    The aim of this paper is the characterization of four thermoluminescence detectors (TLD), namely, LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu for the measurement of the entrance surface air kerma (ESAK) and estimation of the mean glandular dose (MGD) in digital mammography examinations at hospitals and clinics. Low-energy x-ray beams in the typical energy ranges of mammography, produced with a tungsten target and additional 60 µm molybdenum filtration were implemented and characterized at the Laboratory of Metrology of Ionizing Radiation at Instituto Superior Técnico. These beams were used for the characterization of the TLDs in terms of sensitivity, linearity, reproducibility, energy dependence and fading at 40 °C. The energy dependence test was further extended using clinical beams produced by mammography units at hospitals and clinics. The method proposed by the International Atomic Energy Agency was used for the measurement of ESAK and assessment of MGD. The combined standard uncertainty for the measurement of ESAK (and MGD) was determined in accordance to the Guide to the expression of uncertainty in measurement. The x-ray beams generated in the 23–40 kVp range presented HVL values from 0.36 to 0.46 mm Al. The beam produced at 28 kVp (HVL 0.39 mm Al) was considered as reference. The radiation field defined a circle with 84 mm diameter with a maximum variation of the beam intensity of less than 1% at the top flat (plateau) within 4 cm of the central axis. The estimated total uncertainty for the measurement of air kerma was 0.42%. All the TL detectors tested showed good performance except the commercial Li2B4O7:Mn (or TLD-800) which was excluded due to its poor sensitivity in our experimental set up. Both lithium fluorides showed better linearity and reproducibility as well as lower energy dependence and fading when compared to lithium borates. The stable behaviour of LiF:Mg,Ti and LiF:Mg,Cu,P detectors is reflected in the low combined

  8. Assessment of the mean glandular dose using LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu TL detectors in mammography radiation fields

    Science.gov (United States)

    Fartaria, M. J.; Reis, C.; Pereira, J.; Pereira, M. F.; Cardoso, J. V.; Santos, L. M.; Oliveira, C.; Holovey, V.; Pascoal, A.; Alves, J. G.

    2016-09-01

    The aim of this paper is the characterization of four thermoluminescence detectors (TLD), namely, LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu for the measurement of the entrance surface air kerma (ESAK) and estimation of the mean glandular dose (MGD) in digital mammography examinations at hospitals and clinics. Low-energy x-ray beams in the typical energy ranges of mammography, produced with a tungsten target and additional 60 µm molybdenum filtration were implemented and characterized at the Laboratory of Metrology of Ionizing Radiation at Instituto Superior Técnico. These beams were used for the characterization of the TLDs in terms of sensitivity, linearity, reproducibility, energy dependence and fading at 40 °C. The energy dependence test was further extended using clinical beams produced by mammography units at hospitals and clinics. The method proposed by the International Atomic Energy Agency was used for the measurement of ESAK and assessment of MGD. The combined standard uncertainty for the measurement of ESAK (and MGD) was determined in accordance to the Guide to the expression of uncertainty in measurement. The x-ray beams generated in the 23-40 kVp range presented HVL values from 0.36 to 0.46 mm Al. The beam produced at 28 kVp (HVL 0.39 mm Al) was considered as reference. The radiation field defined a circle with 84 mm diameter with a maximum variation of the beam intensity of less than 1% at the top flat (plateau) within 4 cm of the central axis. The estimated total uncertainty for the measurement of air kerma was 0.42%. All the TL detectors tested showed good performance except the commercial Li2B4O7:Mn (or TLD-800) which was excluded due to its poor sensitivity in our experimental set up. Both lithium fluorides showed better linearity and reproducibility as well as lower energy dependence and fading when compared to lithium borates. The stable behaviour of LiF:Mg,Ti and LiF:Mg,Cu,P detectors is reflected in the low combined standard

  9. Assessment of the mean glandular dose using LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu TL detectors in mammography radiation fields.

    Science.gov (United States)

    Fartaria, M J; Reis, C; Pereira, J; Pereira, M F; Cardoso, J V; Santos, L M; Oliveira, C; Holovey, V; Pascoal, A; Alves, J G

    2016-09-01

    The aim of this paper is the characterization of four thermoluminescence detectors (TLD), namely, LiF:Mg,Ti, LiF:Mg,Cu,P, Li2B4O7:Mn and Li2B4O7:Cu for the measurement of the entrance surface air kerma (ESAK) and estimation of the mean glandular dose (MGD) in digital mammography examinations at hospitals and clinics. Low-energy x-ray beams in the typical energy ranges of mammography, produced with a tungsten target and additional 60 µm molybdenum filtration were implemented and characterized at the Laboratory of Metrology of Ionizing Radiation at Instituto Superior Técnico. These beams were used for the characterization of the TLDs in terms of sensitivity, linearity, reproducibility, energy dependence and fading at 40 °C. The energy dependence test was further extended using clinical beams produced by mammography units at hospitals and clinics. The method proposed by the International Atomic Energy Agency was used for the measurement of ESAK and assessment of MGD. The combined standard uncertainty for the measurement of ESAK (and MGD) was determined in accordance to the Guide to the expression of uncertainty in measurement. The x-ray beams generated in the 23-40 kVp range presented HVL values from 0.36 to 0.46 mm Al. The beam produced at 28 kVp (HVL 0.39 mm Al) was considered as reference. The radiation field defined a circle with 84 mm diameter with a maximum variation of the beam intensity of less than 1% at the top flat (plateau) within 4 cm of the central axis. The estimated total uncertainty for the measurement of air kerma was 0.42%. All the TL detectors tested showed good performance except the commercial Li2B4O7:Mn (or TLD-800) which was excluded due to its poor sensitivity in our experimental set up. Both lithium fluorides showed better linearity and reproducibility as well as lower energy dependence and fading when compared to lithium borates. The stable behaviour of LiF:Mg,Ti and LiF:Mg,Cu,P detectors is reflected in the low combined standard

  10. Comparisons of point and average organ dose within an anthropomorphic physical phantom and a computational model of the newborn patient.

    Science.gov (United States)

    Sessions, J B; Roshau, J N; Tressler, M A; Hintenlang, D E; Arreola, M M; Williams, J L; Bouchet, L G; Bolch, W E

    2002-06-01

    Pediatric radiographic examinations yield medical benefits and/or diagnostic information that must be balanced against potential risk from patient radiation exposure. Consequently, clinical tools for measuring internal organ dose are needed for medical risk assessment. In this study, a physical phantom and Monte Carlo simulation model of the newborn patient were developed based upon their stylized mathematical expressions (ORNL and MIRD model series). The physical phantom was constructed using tissue equivalent substitutes for soft tissue, lung, and skeleton. Twenty metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters were then inserted at three-dimensional positions representing the centroids of organs assigned in the ICRP's definition of the effective dose. MOSFET-derived point estimates of organ dose were shown to be in reasonable agreement with Monte Carlo estimates for representative newborn head, chest, and abdomen radiographic exams. Ratios of average organ dose assessed via MCNP simulations to the MOSFET-derived point doses (point-to-organ dose scaling factors, SF(POD)) are tabulated for subsequent use in clinical irradiations of the newborn phantom/MOSFET system. Values of SF(POD) indicate that MOSFET measurements of point dose for in-field exposures need to be adjusted only to within 10% to report volume-averaged organ dose. Larger adjustments to point doses are noted for organs out-of-field. For walled organs, point estimates of organ dose at the content centroid are shown to underestimate the average wall dose when the organ is within the primary field: SF(POD) of 1.19 for the stomach (AP chest exam), and SF(POD) of 1.15 for the urinary bladder (AP abdomen exam).

  11. Assessment of the effects of CT dose in averaged x-ray CT images of a dose-sensitive polymer gel

    International Nuclear Information System (INIS)

    The signal-to-noise ratio achievable in x-ray computed tomography (CT) images of polymer gels can be increased by averaging over multiple scans of each sample. However, repeated scanning delivers a small additional dose to the gel which may compromise the accuracy of the dose measurement. In this study, a NIPAM-based polymer gel was irradiated and then CT scanned 25 times, with the resulting data used to derive an averaged image and a ''zero-scan'' image of the gel. Comparison between these two results and the first scan of the gel showed that the averaged and zero-scan images provided better contrast, higher contrast-to- noise and higher signal-to-noise than the initial scan. The pixel values (Hounsfield units, HU) in the averaged image were not noticeably elevated, compared to the zero-scan result and the gradients used in the linear extrapolation of the zero-scan images were small and symmetrically distributed around zero. These results indicate that the averaged image was not artificially lightened by the small, additional dose delivered during CT scanning. This work demonstrates the broader usefulness of the zero-scan method as a means to verify the dosimetric accuracy of gel images derived from averaged x-ray CT data

  12. Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kock, A.

    1996-05-01

    The objectives of this research are: (1) to calculate and compare off site doses from atmospheric tritium releases at the Savannah River Site using monthly versus 5 year meteorological data and annual source terms, including additional seasonal and site specific parameters not included in present annual assessments; and (2) to calculate the range of the above dose estimates based on distributions in model parameters given by uncertainty estimates found in the literature. Consideration will be given to the sensitivity of parameters given in former studies.

  13. Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters

    International Nuclear Information System (INIS)

    The objectives of this research are: (1) to calculate and compare off site doses from atmospheric tritium releases at the Savannah River Site using monthly versus 5 year meteorological data and annual source terms, including additional seasonal and site specific parameters not included in present annual assessments; and (2) to calculate the range of the above dose estimates based on distributions in model parameters given by uncertainty estimates found in the literature. Consideration will be given to the sensitivity of parameters given in former studies

  14. SU-C-207-02: A Method to Estimate the Average Planar Dose From a C-Arm CBCT Acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Supanich, MP [Rush University Medical Center, Chicago, IL (United States)

    2015-06-15

    Purpose: The planar average dose in a C-arm Cone Beam CT (CBCT) acquisition had been estimated in the past by averaging the four peripheral dose measurements in a CTDI phantom and then using the standard 2/3rds peripheral and 1/3 central CTDIw method (hereafter referred to as Dw). The accuracy of this assumption has not been investigated and the purpose of this work is to test the presumed relationship. Methods: Dose measurements were made in the central plane of two consecutively placed 16cm CTDI phantoms using a 0.6cc ionization chamber at each of the 4 peripheral dose bores and in the central dose bore for a C-arm CBCT protocol. The same setup was scanned with a circular cut-out of radiosensitive gafchromic film positioned between the two phantoms to capture the planar dose distribution. Calibration curves for color pixel value after scanning were generated from film strips irradiated at different known dose levels. The planar average dose for red and green pixel values was calculated by summing the dose values in the irradiated circular film cut out. Dw was calculated using the ionization chamber measurements and film dose values at the location of each of the dose bores. Results: The planar average dose using both the red and green pixel color calibration curves were within 10% agreement of the planar average dose estimated using the Dw method of film dose values at the bore locations. Additionally, an average of the planar average doses calculated using the red and green calibration curves differed from the ionization chamber Dw estimate by only 5%. Conclusion: The method of calculating the planar average dose at the central plane of a C-arm CBCT non-360 rotation by calculating Dw from peripheral and central dose bore measurements is a reasonable approach to estimating the planar average dose. Research Grant, Siemens AG.

  15. Assessment of annual average effective dose status in the cohort of medical staff in Lithuania during 1991-2013.

    Science.gov (United States)

    Samerdokiene, Vitalija; Mastauskas, Albinas; Atkocius, Vydmantas

    2015-12-01

    The use of radiation sources for various medical purposes is closely related to irradiation of the medical staff, which causes harmful effects to health and an increased risk of cancer. In total, 1463 medical staff who have been occupationally exposed to sources of ionising radiation (IR) had been monitored. Records with annual dose measurements (N = 19 157) were collected and regularly analysed for a 23-y period: from 01 January 1991 to 31 December 2013. The collected annual average effective dose (AAED) data have been analysed according to different socio-demographic parameters and will be used in future investigation in order to assess cancer risk among medical staff occupationally exposed to sources of IR. A thorough analysis of data extracted from medical staff's dose records allows one to conclude that the average annual effective dose of Lithuanian medical staff occupationally exposed to sources of IR was consistently decreased from 1991 (1.75 mSv) to 2013 (0.27 mSv) (p < 0.0001). PMID:25614631

  16. Assessment of annual average effective dose status in the cohort of medical staff in Lithuania during 1991-2013

    International Nuclear Information System (INIS)

    The use of radiation sources for various medical purposes is closely related to irradiation of the medical staff, which causes harmful effects to health and an increased risk of cancer. In total, 1463 medical staff who have been occupationally exposed to sources of ionising radiation (IR) had been monitored. Records with annual dose measurements (N = 19 157) were collected and regularly analysed for a 23-y period: from 01 January 1991 to 31 December 2013. The collected annual average effective dose (AAED) data have been analysed according to different socio-demographic parameters and will be used in future investigation in order to assess cancer risk among medical staff occupationally exposed to sources of IR. A thorough analysis of data extracted from medical staff's dose records allows one to conclude that the average annual effective dose of Lithuanian medical staff occupationally exposed to sources of IR was consistently decreased from 1991 (1.75 mSv) to 2013 (0.27 mSv) (p < 0.0001). (authors)

  17. Global characterization of Artemisia annua glandular trichome transcriptome using 454 pyrosequencing

    Directory of Open Access Journals (Sweden)

    Qi Yan

    2009-10-01

    Full Text Available Abstract Background Glandular trichomes produce a wide variety of commercially important secondary metabolites in many plant species. The most prominent anti-malarial drug artemisinin, a sesquiterpene lactone, is produced in glandular trichomes of Artemisia annua. However, only limited genomic information is currently available in this non-model plant species. Results We present a global characterization of A. annua glandular trichome transcriptome using 454 pyrosequencing. Sequencing runs using two normalized cDNA collections from glandular trichomes yielded 406,044 expressed sequence tags (average length = 210 nucleotides, which assembled into 42,678 contigs and 147,699 singletons. Performing a second sequencing run only increased the number of genes identified by ~30%, indicating that massively parallel pyrosequencing provides deep coverage of the A. annua trichome transcriptome. By BLAST search against the NCBI non-redundant protein database, putative functions were assigned to over 28,573 unigenes, including previously undescribed enzymes likely involved in sesquiterpene biosynthesis. Comparison with ESTs derived from trichome collections of other plant species revealed expressed genes in common functional categories across different plant species. RT-PCR analysis confirmed the expression of selected unigenes and novel transcripts in A. annua glandular trichomes. Conclusion The presence of contigs corresponding to enzymes for terpenoids and flavonoids biosynthesis suggests important metabolic activity in A. annua glandular trichomes. Our comprehensive survey of genes expressed in glandular trichome will facilitate new gene discovery and shed light on the regulatory mechanism of artemisinin metabolism and trichome function in A. annua.

  18. Breast Glandularity in Malaysian Women from a Full-Field Digital Mammography System

    International Nuclear Information System (INIS)

    This study is undertaken to estimate breast glandularity in Malaysian women from a Full-Field Digital mammography System. This study involved 223 women (Malay=100;Chinese=101 and Indian=22) underwent voluntary screening mammography at Breast Centre, International Islamic University Malaysia (IIUM Breast Centre) for the first quarter of year 2009. Those are women aged between 31 to 69 years old (median age, 49 years). Data on miliampere-seconds, kilo voltage and compressed breast thickness for each cranio caudal view are used to estimate breast glandularity for an individual breast. Breast glandularity is calculated using the fitted equation reported earlier. The difference in breast glandularity among ethnic groups was tested for significance using the nonparametric Kruskal-Wallis test. The average breast glandularity estimated in our study, using FFDM system is 52.94±27.63 %. No significant difference was seen in breast glandularity among the ethnic groups (p>0.05, Kruskan Wallis test). Breast glandularity decrease as age increases, up to 60 years old. (author)

  19. Morphological differentiation and distribution of non-glandular and glandular trichomes on Dracocephalum moldavicum L. shoots

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The structure, micromorphology and distribution of trichomes on Dracocephalum moldavicum L. shots were investigated using light and scanning electron microscopy (SEM. There were distinguished 3 types of non-glandular trichomes, 3 types of glandular trichomes and papillae of the osmophore in the epidermis of the corolla. The highest density of non-glandular and glandular trichomes was found on the abaxial surface of the calyx, on bracts and in the upper part of the stem. Structural variations in the head and stalk of long glandular trichomes were demonstrated. The dimensions of particular types of trichomes are given in the present paper. Differences in the structure of the trichomes of this species are presented, compared to literature data. The micromorphology of particular trichome types is documented in numerous photographs showing the rich ornamentation of the cuticle of non-glandular trichomes.

  20. ASSESSMENT OF THE AVERAGE ANNUAL EFFECTIVE DOSES FOR THE INHABITANTS OF THE SETTLEMENTS LOCATED IN THE TERRITORIES CONTAMINATED DUE TO THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    N. G. Vlasova

    2012-01-01

    Full Text Available Catalogue of the average annual effective exposure doses of the inhabitants of the territories contaminated due to the Chernobul accident had been developed according to the method of the assessment of the average annual effective exposure doses of the settlements inhabitants. The cost-efficacy of the use of the average annual effective dose assessment method was 250 000 USD for the current 5 years. Average annual effective dose exceeded 1 mSv/year for 191 Belarus settlements from 2613. About 50 000 persons are living in these settlements.

  1. Applying the conventional moving average filter for estimation of low radiation doses using EPR spectroscopy: Benefits and drawbacks

    Energy Technology Data Exchange (ETDEWEB)

    Maghraby, Ahmed M., E-mail: maghrabism@yahoo.com [National Institute of Standards (NIS), Radiation Dosimetry Department, Ministry of Scientific Research, Tersa Street, P.O. Box 136, Giza, Haram 12211 (Egypt); Physics Department, Faculty of Science and Humanities, Salman Bin AbdulAziz University, Alkharj (Saudi Arabia)

    2014-02-11

    Alanine/EPR is the most common dosimetry system for high radiation doses because of its high stability and wide linear response, however, use of alanine in most of medical applications still require special sophisticated methodologies and techniques in order to extend alanine detection limit to low levels of radiation doses. One of these techniques is the use of digital processing of acquired alanine spectra for enhancing useful components in spectra while useless features are suppressed. Simple moving average filter (MA) impacts on alanine EPR spectra have been studied in terms of peak-to-peak height, peak-to-peak line width, and associated uncertainty. Three types of the used filter were investigated: upward MA, central MA, and downward MA filters, effects of each on the peak position for different values of filter width were studied. It was found that MA filter always lead to the reduction in signal intensity and the increase of line width of the central peak of alanine spectrum. Peak position also changes in cases of the upward MA and downward MA filters while no significant changes were observed in the case of central MA. Uncertainties associated to the averaging process were evaluated and plotted versus the filter width resulting in a linear relationship. Filter width value should be carefully selected in order to avoid probable distortion in processed spectra while gaining less noisy spectra with less associated uncertainties.

  2. Experimental measurement of radiation dose in a dedicated breast CT system

    CERN Document Server

    Shan-Wei, Shen; Hang, Shu; Xiao, Tang; Cun-Feng, Wei; Yu-Shou, Song; Rong-Jian, Shi; Long, Wei

    2013-01-01

    Radiation dose is an important performance indicator of a dedicated breast CT (DBCT). In this paper, the method of putting thermoluminescent dosimeters (TLD) into a breast shaped PMMA phantom to study the dose distribution in breasts was improved by using smaller TLDs and a new half-ellipsoid PMMA phantom. Then the weighted CT dose index (CTDIw) was introduced to average glandular assessment in DBCT for the first time and two measurement modes were proposed for different sizes of breasts. The dose deviations caused by using cylindrical phantoms were simulated using the Monte Carlo method and a set of correction factors were calculated. The results of the confirmatory measurement with a cylindrical phantom (11cm/8cm) show that CTDIw gives a relatively conservative overestimate of the average glandular dose comparing to the results of Monte Carlo simulation and TLDs measurement. But with better practicability and stability, the CTDIw is suitable for dose evaluations in daily clinical practice. Both of the TLDs ...

  3. JUSTIFICATION OF TRANSITION FROM ZONING OF CONTAMINATED TERRITORIES TO SETTLEMENTS CLASSIFICATION AT AN AVERAGE ANNUAL EFFECTIVE DOSES IN REMOTE PERIOD AFTER THE CHERNOBYL NPP ACCIDENT

    Directory of Open Access Journals (Sweden)

    N. G. Vlasova

    2016-01-01

    Full Text Available In an existing exposure situation (in a remote period after the Chernobyl accident there is a need of the transition from "radioactive area zoning" to "the settlements classification by average annual effective doses to the critical group of persons among the settlement's residents", to ensure the appropriate radiation level and social protection of the settlement's residents, located on the contaminated territory.The comparative allocation analysis of the average annual external and internal effective doses, the average annual effective cumulative doses to residents of settlements, related to the relevant areas (the Council of Ministers of Belarus latest decision, the proposed dose range according to the Catalogue of average annual effective doses of residents of settlements radiation Republic of Belarus confirmed the validity of the transition from "radioactive zoning area" to "the classification of settlements by average annual effective dose."In accordance with the radiation protection principles, it seems reasonable to classify the settlements located on the contaminated territory at the average annual effective dose as follows: < 0.1 mSv / year (not required to carry out radiation protection measures in the agricultural sector;  0.1-1 mSv / year (periodic radiation monitoring should be carried out;  1 mSv / year (it is necessary to apply a complex of protective measures.

  4. Patient dose in full-field digital mammography: an Italian survey

    Energy Technology Data Exchange (ETDEWEB)

    Gennaro, Gisella; Di Maggio, Cosimo [Department of Oncological Sciences, Padua University, Via Gattamelata 64, 35128, Padua (Italy); Baldelli, Paola; Taibi, Angelo; Gambaccini, Mauro [Department of Physics, Ferrara University, Via Paradiso 12, 44100, Ferrara (Italy)

    2004-04-01

    The aim of this study was to compare performance and patient dose of full-field digital mammography units for clinical use. Measurements of linearity and automatic exposure control stability were performed on four units installed in as many Italian sites. The tube output was also obtained by the same ionization chamber, permitting to evaluate ratios mGy/mAs for each available spectrum. The entrance air-kerma was calculated over a sample of 800 cranio-caudal mammograms and the average glandular dose obtained, assuming two mean glandular compositions of 50 and 30%, respectively. Digital systems showed very good linearity and comparable responses. The stability of the automatic exposure control was better than 5% for all systems. Regarding doses, the two mammography units that work mainly in contrast mode deliver, respectively, 17 and 28% more dose compared with those working in standard mode. For the latter mode, the mean average glandular dose was in the range 1.25-1.37 mGy and 1.37-1.49 mGy for the 50 and 30% glandular composition, respectively. Results of this study were compared with those of other surveys, showing that full-field digital mammography allows a significant clinical dose reduction compared with screen/film mammography. (orig.)

  5. Evaluation of the image quality criteria and study of doses in a mammography department

    International Nuclear Information System (INIS)

    The mammographic image quality criteria published by European Commission were implemented in three mammography equipment of a same radiology department in a hospital of Sao Paulo city. Among the mammography equipment, two use the screen-film system and one of them uses the indirect digital system. During the data collection, it was noted the need to conduct a study about image rejection in each mammography equipment. Therefore, this study was realized and, after that, the results in each mammography equipment of image rejection and image percentage that present each quality criterion it were compared. At the same time of this studies, it was realized other study about surface entrance dose and average glandular dose. These doses it was estimated based on different methods published by different groups of researcher, for all combinations anode filter available in the equipment. To estimate the surface entrance dose following the methodology published in Avenue's' guide and the average glandular dose following the Wu' methodology, it was developed a phantom, in different thicknesses of acrylic, to simulate a breast. Finally, the image quality it was associated with the dose received by patient. The digital equipment shows better results in the evaluation of quality criteria, lower rate of image rejection and lower values of average glandular dose and surface entrance dose in all methods studied. But it is not sufficient, because is not adequate for patients with great breast. (author)

  6. Inflammatory and glandular skin disease in pregnancy.

    Science.gov (United States)

    Yang, Catherine S; Teeple, Mary; Muglia, Jennie; Robinson-Bostom, Leslie

    2016-01-01

    A switch from cell-mediated to humoral immunity (helper T 1 [Th1] to helper T 2 [Th2] shift) during gestation plays a key role in placental immune tolerance. As a result, skin diseases that are Th2 mediated often worsen, whereas skin diseases that are Th1 mediated often improve during gestation. Also, due to fluctuations in glandular activity, skin diseases involving sebaceous and eccrine glands may flare, whereas those involving apocrine glands may improve during pregnancy. Despite these trends, inflammatory and glandular skin diseases do not always follow the predicted pattern, and courses are often diverse. We review the gestational course of inflammatory skin diseases, such as atopic dermatitis (atopic eruption of pregnancy), psoriasis, impetigo herpetiformis, urticaria, erythema annulare centrifugum, pityriasis rosea, sarcoidosis, Sweet syndrome, and erythema nodosum, as well as glandular skin diseases, including acne vulgaris, acne rosacea, perioral dermatitis, hidradenitis suppurativa, Fox-Fordyce disease, hyperhidrosis, and miliaria. For each of these diseases, we discuss the pathogenesis, clinical presentation, and management with special consideration for maternal and fetal safety. PMID:27265071

  7. Radiation doses from mammography in Australia

    International Nuclear Information System (INIS)

    During 1989-90 the Australian Radiation Laboratory conducted a postal survey of at least 90% of the mammographic facilities in Australia. The primary aim of the survey was to measure the mean glandular dose (MGD) and the X-ray beam half value layer (HVL) for a typical mammograph. The MGD and HVL were measured with a specially designed tissue equivalent monitor. In all, 258 mammographic centres were surveyed. It was found that for centres using film-screen imaging, the average mean glandular dose was 1.83 mGy for centres using grids and 0.84 mGy for centres not using grids. In addition to the MGD and HVL, comprehensive statistical information was collected and data is presented on the types of equipment and techniques used, the number and age of patients and demographic distribution of centres. Results indicate that the use of a grid is the major factor determining dose and several other factors appear to have minor effects. In view of the distribution of MGD, it is recommended that the mean glandular dose per image, for a 5 cm compressed breast thickness, should not exceed 2.0 mGy when a grid is used and 1.0 mGy without a grid. 63 refs., 11 tabs., 15 figs

  8. Glandular odontogenic cyst: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Tambawaia, Shahnaz S.; Karjodkar, Freny R.; Yadav, Archana; Sansare, Kaustubh; Sontakke, Subodh [Nair Hospital Dental College, Mumbai (India)

    2014-03-15

    Glandular odontogenic cysts (GOCs) are rare intrabony solitary or multiloculated cysts of odontogenic origin. The importance of GOCs lies in the fact that they exhibit a propensity for recurrence similar to keratocystic odontogenic tumors and that they may be confused microscopically with central mucoepidermoid carcinoma. Thus, the oral and maxillofacial radiologists play an important role in definitive diagnosis of GOC based on distinctive cases; though they are rare. In large part, this is due to the GOC's complex and frequently non-specific histopathology. This report describes a case of GOC occurrence in the posterior mandibular ramus region in a 17-year-old female, which is a rare combination of site, age, and gender for occurrence.

  9. Analysis of the track- and dose-averaged LET and LET spectra in proton therapy using the GEANT4 Monte Carlo code

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Fada; Peeler, Christopher; Taleei, Reza; Randeniya, Sharmalee; Ge, Shuaiping; Mirkovic, Dragan; Mohan, Radhe; Titt, Uwe, E-mail: UTitt@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Bronk, Lawrence [Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Geng, Changran [Department of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China and Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Grosshans, David [Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States)

    2015-11-15

    Purpose: The motivation of this study was to find and eliminate the cause of errors in dose-averaged linear energy transfer (LET) calculations from therapeutic protons in small targets, such as biological cell layers, calculated using the GEANT 4 Monte Carlo code. Furthermore, the purpose was also to provide a recommendation to select an appropriate LET quantity from GEANT 4 simulations to correlate with biological effectiveness of therapeutic protons. Methods: The authors developed a particle tracking step based strategy to calculate the average LET quantities (track-averaged LET, LET{sub t} and dose-averaged LET, LET{sub d}) using GEANT 4 for different tracking step size limits. A step size limit refers to the maximally allowable tracking step length. The authors investigated how the tracking step size limit influenced the calculated LET{sub t} and LET{sub d} of protons with six different step limits ranging from 1 to 500 μm in a water phantom irradiated by a 79.7-MeV clinical proton beam. In addition, the authors analyzed the detailed stochastic energy deposition information including fluence spectra and dose spectra of the energy-deposition-per-step of protons. As a reference, the authors also calculated the averaged LET and analyzed the LET spectra combining the Monte Carlo method and the deterministic method. Relative biological effectiveness (RBE) calculations were performed to illustrate the impact of different LET calculation methods on the RBE-weighted dose. Results: Simulation results showed that the step limit effect was small for LET{sub t} but significant for LET{sub d}. This resulted from differences in the energy-deposition-per-step between the fluence spectra and dose spectra at different depths in the phantom. Using the Monte Carlo particle tracking method in GEANT 4 can result in incorrect LET{sub d} calculation results in the dose plateau region for small step limits. The erroneous LET{sub d} results can be attributed to the algorithm to

  10. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-12-15

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  11. Structure and distribution of glandular and non-glandular trichomes on above-ground organs in Inula helenium L. (Asteraceae

    Directory of Open Access Journals (Sweden)

    Aneta Sulborska

    2014-01-01

    Full Text Available Micromorphology and distribution of glandular and non-glandular trichomes on the above-ground organs of Inula helenium L. were investigated using light and scanning electron microscopy (SEM. Two types of biseriate glandular trichomes, i.e. sessile and stalk hairs, and non-glandular trichomes were recorded. Sessile glandular trichomes were found on all examined I. helenium organs (with their highest density on the abaxial surface of leaves and disk florets, and on stems, whereas stalk glandular trichomes were found on leaves and stems. Sessile trichomes were characterised by a slightly lower height (58–103 μm and width (32–35 μm than the stalk trichomes (62–111 μm x 31–36 μm. Glandular hairs were composed of 5–7 (sessile trichomes or 6–9 (stalk trichomes cell tiers. Apical trichome cell tiers exhibited features of secretory cells. Secretion was accumulated in subcuticular space, which expanded and ruptured at the top, and released its content. Histochemical assays showed the presence of lipids and polyphenols, whereas no starch was detected. Non-glandular trichomes were seen on involucral bracts, leaves and stems (more frequently on involucral bracts. Their structure comprised 2–9 cells; basal cells (1–6 were smaller and linearly arranged, while apical cells had a prozenchymatous shape. The apical cell was the longest and sharply pointed. Applied histochemical tests revealed orange-red (presence of lipids and brow colour (presence of polyphenols in the apical cells of the trichomes. This may suggest that beside their protective role, the trichomes may participate in secretion of secondary metabolites.

  12. Multi-Institution Prospective Trial of Reduced-Dose Craniospinal Irradiation (23.4 Gy) Followed by Conformal Posterior Fossa (36 Gy) and Primary Site Irradiation (55.8 Gy) and Dose-Intensive Chemotherapy for Average-Risk Medulloblastoma

    International Nuclear Information System (INIS)

    Purpose: Limiting the neurocognitive sequelae of radiotherapy (RT) has been an objective in the treatment of medulloblastoma. Conformal RT to less than the entire posterior fossa (PF) after craniospinal irradiation might reduce neurocognitive sequelae and requires evaluation. Methods and Materials: Between October 1996 and August 2003, 86 patients, 3-21 years of age, with newly diagnosed, average-risk medulloblastoma were treated in a prospective, institutional review board-approved, multi-institution trial of risk-adapted RT and dose-intensive chemotherapy. RT began within 28 days of definitive surgery and consisted of craniospinal irradiation (23.4 Gy), conformal PF RT (36.0 Gy), and primary site RT (55.8 Gy). The planning target volume for the primary site included the postoperative tumor bed surrounded by an anatomically confined margin of 2 cm that was then expanded with a geometric margin of 0.3-0.5 cm. Chemotherapy was initiated 6 weeks after RT and included four cycles of high-dose cyclophosphamide, cisplatin, and vincristine. Results: At a median follow-up of 61.2 months (range, 5.2-115.0 months), the estimated 5-year event-free survival and cumulative incidence of PF failure rate was 83.0% ± 5.3% and 4.9% ± 2.4% (± standard error), respectively. The targeting guidelines used in this study resulted in a mean reduction of 13% in the volume of the PF receiving doses >55 Gy compared with conventionally planned RT. The reductions in the dose to the temporal lobes, cochleae, and hypothalamus were statistically significant. Conclusion: This prospective trial has demonstrated that irradiation of less than the entire PF after 23.4 Gy craniospinal irradiation for average-risk medulloblastoma results in disease control comparable to that after treatment of the entire PF

  13. Patient doses and radiation risks in film-screen mammography in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A.; Parviainen, T.; Komppa, T. [Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland)

    1995-12-31

    Screen-film mamography is the most sensitive method for the early detection of breast cancer. Breast doses in mamography should be measured for several reasons, especially for the evaluation of patient risk in a screening programme, but also for the assessment and comparison of imaging techniques and equipment performance. In this study, the factors affecting patient doses were assessed by making performance and patient dose measurements; about 50 mammographic units used for screening were included in the study. The lifetime risk as a function of age at exposure was calculated using the average glandular dose, the relative risk model shown in the BEIR V report, and the breast cancer mortality in Finland. The mean surface dose of a 4.5 cm thick phantom was 6.3 mGy, and the mean glandular dose 1.0 mGy. Analysis of the surface dose with respect to film optical density, relative speed of film processing, sensitivity of image receptors, and antiscatter grid showed that the mean surface dose could be decreased by more than 50%. For the screened age group of 50 to 59 years, the risk of exposure-induced death (REID) of breast cancer is about 1.4 x 10{sup -6} mSv{sup -1}, and the average loss of life expectancy due to the radiation-induced breast cancer deaths (LLE/REID) is about 9.5 years. (Author).

  14. The nonvolatile metabolome of sunflower linear glandular trichomes.

    Science.gov (United States)

    Spring, Otmar; Pfannstiel, Jens; Klaiber, Iris; Conrad, Jürgen; Beifuß, Uwe; Apel, Lysanne; Aschenbrenner, Anna-Katharina; Zipper, Reinhard

    2015-11-01

    Uniseriate linear glandular trichomes occur on stems, leaves and flowering parts of Helianthus species and related taxa. Their metabolic activity and biological function are still poorly understood. A phytochemical study documented the accumulation of bisabolene type sesquiterpenes and flavonoids as the major constituents of the non-volatile metabolome of linear glandular trichomes in the common sunflower, Helianthus annuus. Besides known sesquiterpenes of the glandulone, helibisabonol and heliannuol type, four previously undescribed sesquiterpenes named glandulone D, E, F and helibisabonol C were identified by spectroscopic analysis. In addition, four known nevadensin type flavonoids varying in O-methoxy substitutions were found. None of them has previously been reported from Helianthus annuus. PMID:26412774

  15. Glandular Trichomes and Essential Oil of Thymus quinquecostatus

    Directory of Open Access Journals (Sweden)

    Ping Jia

    2013-01-01

    Full Text Available The distribution and types of glandular trichomes and essential oil chemistry of Thymus quinquecostatus were studied. The glandular trichomes are distributed on the surface of stem, leaf, rachis, calyx and corolla, except petiole, pistil and stamen. Three morphologically distinct types of glandular trichomes are described. Peltate trichomes, consisting of a basal cell, a stalk cell and a 12-celled head, are distributed on the stem, leaf, corolla and outer side of calyx. Capitate trichomes, consisting of a unicellular base, a 1–2-celled stalk and a unicellular head, are distributed more diffusely than peltate ones, existing on stem, leaf, rachis and calyx. Digitiform trichomes are just distributed on the outer side of corolla, consisting of 1 basal cell, 3 stalk cells and 1 head cell. All three types of glandular trichomes can secrete essential oil, and in small capitate trichomes of rachis, all peltate trichomes and digitiform trichomes, essential oil is stored in a large subcuticular space, released by cuticle rupture, whereas, in other capitate trichomes, essential oil crosses the thin cuticle. The essential oil of T. quinquecostatus is yellow, and its content is highest in the growth period. 68 constituents were identified in the essential oils. The main constituent is linalool.

  16. Giant cardiac myxoma with malignant transformed glandular structures

    Energy Technology Data Exchange (ETDEWEB)

    Eckhardt, Boris P.; Stuckmann, Gerd; Zollikofer, Christoph L. [Institute of Radiology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Dommann-Scherrer, Corina C. [Insitute of Pathology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Wentz, Klaus U. [Institute of Radiology, Cantonal Hospital, Brauerstrasse 15, 8401 Winterthur (Switzerland); Medical Faculty, University of Witten/Herdecke, Alfred-Herrhausen-Strasse 50, 58448 Witten (Germany)

    2003-09-01

    A case of a right-sided giant cardiac myxoma with malignant transformation of glandular structures causing systemic metastases is described. Plain chest radiography and computed tomography localized the tumor within the heart. Exact depiction of the origin of the tumor using subtracted 2D-projection MR angiography is documented. Radiologic findings and differential diagnosis of this unique tumor are discussed. (orig.)

  17. Average bioequivalence of single 500 mg doses of two oral formulations of levofloxacin: a randomized, open-label, two-period crossover study in healthy adult Brazilian volunteers

    Directory of Open Access Journals (Sweden)

    Eunice Kazue Kano

    2015-03-01

    Full Text Available Average bioequivalence of two 500 mg levofloxacin formulations available in Brazil, Tavanic(c (Sanofi-Aventis Farmacêutica Ltda, Brazil, reference product and Levaquin(c (Janssen-Cilag Farmacêutica Ltda, Brazil, test product was evaluated by means of a randomized, open-label, 2-way crossover study performed in 26 healthy Brazilian volunteers under fasting conditions. A single dose of 500 mg levofloxacin tablets was orally administered, and blood samples were collected over a period of 48 hours. Levofloxacin plasmatic concentrations were determined using a validated HPLC method. Pharmacokinetic parameters Cmax, Tmax, Kel, T1/2el, AUC0-t and AUC0-inf were calculated using noncompartmental analysis. Bioequivalence was determined by calculating 90% confidence intervals (90% CI for the ratio of Cmax, AUC0-t and AUC0-inf values for test and reference products, using logarithmic transformed data. Tolerability was assessed by monitoring vital signs and laboratory analysis results, by subject interviews and by spontaneous report of adverse events. 90% CIs for Cmax, AUC0-t and AUC0-inf were 92.1% - 108.2%, 90.7% - 98.0%, and 94.8% - 100.0%, respectively. Observed adverse events were nausea and headache. It was concluded that Tavanic(c and Levaquin(c are bioequivalent, since 90% CIs are within the 80% - 125% interval proposed by regulatory agencies.

  18. Pulmonary mixed squamous cell and glandular papilloma mimicking adenocarcinoma: a case study and literature review

    OpenAIRE

    Lin, Dongliang; Jiang, Yanxia; Wang, Jigang; Ding, Li; Xin, Fangjie; Zhao, Han; Li, Yujun

    2013-01-01

    Mixed squamous cell and glandular papilloma of the lung is an extremely rare benign neoplasm. Here we present another case of mixed squamous cell and glandular papilloma in a 64-year-old female nonsmoker. Histologically, the tumor was composed of mainly papillary structures covered with squamous, glandular and transitional epithelium. Some glandular structures extending into adjacent bronchiolar and alveolar spaces with mucus were similar to adenocarcinoma. Immunohistochemical analysis showed...

  19. Estimation of radionuclides concentration and average annual committed effective dose due to ingestion for some selected medicinal plants of South India

    Directory of Open Access Journals (Sweden)

    K. Chandrashekara

    2016-01-01

    Full Text Available Eight medicinal plants and soil samples from the Malnad area of Karnataka in South India (N 13°29′35.4″; E 75°18′02.4″ were analysed for activity concentrations of natural and artificial radionuclides using HPGe gamma spectrometry. The average annual committed effective dose (AACED due to the ingestion of radionuclides from medicinal plants were also estimated. The activity concentrations of 226Ra, 210Pb, 232Th, and 40K were found to vary in the range of 32.27–60.12 Bqkg−1, 56.09–160.56 Bqkg−1, 49.61–98.46 Bqkg−1, and 241.57–712.85 Bqkg−1, respectively, in the soil samples and 2.66–11.27 Bqkg−1, BDL to 87.03 Bqkg−1, 2.42–8.72 Bqkg−1, and 93.79–6831.40 Bqkg−1, respectively, in the medicinal plants corresponding to the soil samples. The activity concentration of artificially produced radionuclide 137Cs was BDL to 12.34 Bqkg−1 in the soil and it was below detectable level (BDL in all the plant samples. The soil to plant transfer factors (TF varied from 0.07 to 0.27, BDL to 0.80, 0.04 to 0.13 and 0.17 to 23.80, respectively, for 226Ra, 210Pb, 232Th, and 40K. The AACED due to the ingestion of radionuclides from the medicinal plants varied from 0.0075 to 0.1067 mSvy−1. The AACED values reported in this study are much below the world average value of 0.30 mSvy−1 for an individual. This indicates that there is no radiological health risk in using these plants for medicinal purposes. This study may also contribute data on local medicinal plants to formulate regulations related to radiological healthcare.

  20. State Averages

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...

  1. Micromorphology of glandular structures in Echium vulgare L. flowers

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The micromorphology of selected elements of Echium vulgare L. flowers was investigated, with special attention to the structure of the nectaries and the stigma of the pistil as well as types of trichomes occurring on the surface of the calyx. The nectary had the shape of an uneven disc located around the lower region of the four-parted ovary of the pistil. The glandular cells formed a tier with a height of 330 μm and a radial width of 144 μm. Nectar was secreted onto the nectary surface through anomocytic stomata located at the level of other epidermal cells. Most of the stomata were open, with a different dimension of the pore. Their largest number was observed at the base of the nectary, and 462 stomata were noted on the whole surface of the nectary. The cuticle on the surface of the guard cells formed fine, circular striae. The subsidiary cells formed striated cuticular ornamentation, with the striae arranged radially in the direction of the stoma, whereas on the surface of other epidermal cells the striae formed an arrangement with different directions. The epidermis on the surface of the stigma formed regularly arranged papillae with a fan-shaped, expanded upper part which had corrugated outer walls, whereas the base of the cell formed a widened small column. The epidermis of the abaxial part of the calyx was covered by numerous non-glandular trichomes of different length which were made up of one or several cells. The glandular trichomes in the epidermis of the calyx grew with smaller density compared to the protective trichomes, and they were composed of a 1-2-celled stalk and a glandular head.

  2. Distribution of DMT 1 within the human glandular system

    OpenAIRE

    Koch, R.O.; H. Zoller; Theurl, I.; Obrist, P.; Egg, G.; Strohmayer, W.; Vogel, W.; Weiss, G. (Günter)

    2003-01-01

    Background & Aims: DMT1 is a transmembrane protein which transports the divalent metal ions Fe2+, Zn2+, Cu2+ and Mn2+. Although DMT1 has been functionally linked to duodenal absorption and cellular utilisation of iron hardly anything is known about its distribution and potential role within the human glandular system. Methods: Two polyclonal antibodies were raised to study the expression of DMT1 in tissues obtained from human corpus by the means of immunocy...

  3. The glandular odontogenic jaw cyst: report of a case.

    Science.gov (United States)

    Savage, N W; Joseph, B K; Monsour, P A; Young, W G

    1996-11-01

    A case of a rare odontogenic cyst arising in the lateral periodontal membrane in the mandible in a 14 year old girl is reported. This lesion appeared to be a new entity and has been named glandular odontogenic cyst (GOC) or sialo-odontogenic cyst. Histologically the lesion was lined by mucous producing cuboidal epithelium containing several areas of thickening and numerous duct-like structures. The cyst recurred with the same histology two years postoperatively.

  4. Genetic basis for glandular trichome formation in cotton.

    Science.gov (United States)

    Ma, Dan; Hu, Yan; Yang, Changqing; Liu, Bingliang; Fang, Lei; Wan, Qun; Liang, Wenhua; Mei, Gaofu; Wang, Lingjian; Wang, Haiping; Ding, Linyun; Dong, Chenguang; Pan, Mengqiao; Chen, Jiedan; Wang, Sen; Chen, Shuqi; Cai, Caiping; Zhu, Xiefei; Guan, Xueying; Zhou, Baoliang; Zhu, Shuijin; Wang, Jiawei; Guo, Wangzhen; Chen, Xiaoya; Zhang, Tianzhen

    2016-01-01

    Trichomes originate from epidermal cells and can be classified as either glandular or non-glandular. Gossypium species are characterized by the presence of small and darkly pigmented lysigenous glands that contain large amounts of gossypol. Here, using a dominant glandless mutant, we characterize GoPGF, which encodes a basic helix-loop-helix domain-containing transcription factor, that we propose is a positive regulator of gland formation. Silencing GoPGF leads to a completely glandless phenotype. A single nucleotide insertion in GoPGF, introducing a premature stop codon is found in the duplicate recessive glandless mutant (gl2gl3). The characterization of GoPGF helps to unravel the regulatory network of glandular structure biogenesis, and has implications for understanding the production of secondary metabolites in glands. It also provides a potential molecular basis to generate glandless seed and glanded cotton to not only supply fibre and oil but also provide a source of protein for human consumption. PMID:26795254

  5. Quaternion Averaging

    Science.gov (United States)

    Markley, F. Landis; Cheng, Yang; Crassidis, John L.; Oshman, Yaakov

    2007-01-01

    Many applications require an algorithm that averages quaternions in an optimal manner. For example, when combining the quaternion outputs of multiple star trackers having this output capability, it is desirable to properly average the quaternions without recomputing the attitude from the the raw star tracker data. Other applications requiring some sort of optimal quaternion averaging include particle filtering and multiple-model adaptive estimation, where weighted quaternions are used to determine the quaternion estimate. For spacecraft attitude estimation applications, derives an optimal averaging scheme to compute the average of a set of weighted attitude matrices using the singular value decomposition method. Focusing on a 4-dimensional quaternion Gaussian distribution on the unit hypersphere, provides an approach to computing the average quaternion by minimizing a quaternion cost function that is equivalent to the attitude matrix cost function Motivated by and extending its results, this Note derives an algorithm that deterniines an optimal average quaternion from a set of scalar- or matrix-weighted quaternions. Rirthermore, a sufficient condition for the uniqueness of the average quaternion, and the equivalence of the mininiization problem, stated herein, to maximum likelihood estimation, are shown.

  6. Dose comparison between screen/film and full-field digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Gennaro, Gisella [Padua University, Department of Oncological and Surgical Sciences, Padua (Italy); INFN (National Institute of Nuclear Physics), Department of Physics, Padua (Italy); Di Maggio, Cosimo [Padua University, Department of Oncological and Surgical Sciences, Padua (Italy)

    2006-11-15

    The study purpose was the comparison between doses delivered by a full-field digital mammography system and a screen/film mammography unit, both using the same type of X-ray tube. Exposure parameters and breast thickness were collected for 300 screen/film (GE Senographe DMR) and 296 digital mammograms (GE Senographe 2000D). The entrance surface air kerma (ESAK) was calculated from anode/filter combination, kV{sub p} and mAs values and breast thickness, by simulating spectra through a program based on a catalogue of experimental X-ray spectra. The average glandular dose (AGD) was also computed. Results showed an overall reduction of average glandular dose by 27% of digital over screen/film mammography. The dose saving was about 15% for thin and thick breasts, while it was between 30% and 40% for intermediate thicknesses. Full-field digital mammography dose reduction is allowed by wider dynamic range and higher efficiency of digital detector, which can be exposed at higher energy spectra than screen/film mammography, and by the separation between acquisition and displaying processes. (orig.)

  7. Botulinum toxin for treatment of glandular hypersecretory disorders.

    LENUS (Irish Health Repository)

    Laing, T A

    2012-02-03

    SUMMARY: The use of botulinum toxin to treat disorders of the salivary glands is increasing in popularity in recent years. Recent reports of the use of botulinum toxin in glandular hypersecretion suggest overall favourable results with minimal side-effects. However, few randomised clinical trials means that data are limited with respect to candidate suitability, treatment dosages, frequency and duration of treatment. We report a selection of such cases from our own department managed with botulinum toxin and review the current data on use of the toxin to treat salivary gland disorders such as Frey\\'s syndrome, excessive salivation (sialorrhoea), focal and general hyperhidrosis, excessive lacrimation and chronic rhinitis.

  8. Methodology for correlations between doses and detectability in standard mammographic images: application in Sao Paulo state

    International Nuclear Information System (INIS)

    Measurements using mammography units were performed in loco in 50 health establishments, randomly sampled from an equipment list of the Cadastro Nacional de Estabelecimentos de Saude (Health Establishments Brazilian Catalog). For the measurements six phantoms were utilized to establish different quality criteria and to evaluate doses in different breast thicknesses. Two different methods of measuring average glandular doses (AGD) were applied, and measurements of entrance surface doses (ESD) were also realized, in order to obtain mean values to Sao Paulo State. A study relating distribution and properties of different mammography trademarks with doses was performed. The sensitometry of processors allowed a quantification of the film-processing contrast index, Ag, establishing a state mean value. The phantom images allowed the evaluation of detection limits of structures as microcalcifications, fibers, and masses, and state mean values were established for: spatial resolution (on surface and glandular breast position); image contrast; and detection expert ability from phantom images in two situations: before knowing the image targets and after viewing of a target map. Then, the results were compared to target detections in laboratory environment. Based on dose results, Ag, image contrast, maximum contrast, and detection ratio, a relationship between them was determined. The results show that, in Sao Paulo State, mean glandular doses were lower than reference levels considering the Wu method, and close to or above reference levels for ail phantoms considering the Dance method. The ESD was always close to or above reference levels. The Ag presented a mean value of (10,42 ± 0,20) for Sao Paulo State, and the image contrast was lower than the required limits established by the phantom manufacturers. The high contrast resolution showed that mammography units presented the expected values of line pair per mm in the State. The detectability evaluation of local experts was

  9. Population Responses of Potato Leafhopper (Hemiptera: Cicadellidae) to Insecticide in Glandular-Haired and Non-glandular-Haired Alfalfa Cultivars.

    Science.gov (United States)

    Sulc, R Mark; McCormick, John S; Hammond, Ronald B; Miller, David J

    2014-12-01

    Conflicting results have been reported on the ability of glandular-haired alfalfa (Medicago sativa L.) cultivars to reduce potato leafhopper, Empoasca fabae Harris, population abundance in field environments. We measured potato leafhopper adult and nymph abundance and yield responses in a cultivar selected for high potato leafhopper resistance ('54H91') and in a non-glandular-haired susceptible cultivar ('54V54') with and without insecticide treatment across 3 yr. Treatments included no insecticide and insecticide applied either early or late in each summer growth cycle. Date × cultivar × treatment interactions were found for potato leafhopper population abundance. In the absence of insecticides, total potato leafhopper abundance (adults + nymphs per sweep) was lower in 54H91 than in 54V54 on 85% of sampling dates; cultivar differences were especially evident as potato leafhopper abundance peaked. Insecticide treatment reduced potato leafhopper populations in both cultivars, but populations recovered and often exceeded the normal action threshold in both cultivars within 2-3 wk of insecticide application. Yield gain from early insecticide treatment of 54V54 was >400 kg/ha in 11 of 14 summer harvests, whereas in 54H91 the yield gain was potato leafhopper resistance significantly suppress potato leafhopper adult and nymph abundance, reduce yield losses in the absence of insecticides, and have potential within an integrated pest management strategy to reduce insecticide use in alfalfa production systems. PMID:26470072

  10. GLANDULAR HAIRS, NON-GLANDULAR HAIRS, AND ESSENTIAL OILS IN THE WINTER AND SUMMER LEAVES OF THE SEASONALLY DIMORPHIC THYMUS SIBTHORPII (LAMIACEAE

    Directory of Open Access Journals (Sweden)

    BOSABALIDIS ARTEMIOS Michael

    2013-12-01

    Full Text Available The structure and function of the glandular and non-glandular hairs, and also the yield and chemical composition of the essential oils in the winter and summer leaves of the seasonally dimorphic plant Thymus sibthorpii were studied. Glandular hairs comprise peltate hairs only (capitate hairs are missing. Peltate hairs are the sites of essential oil biosynthesis. They are more numerous in the winter leaves than in the summer leaves and consist of a 12-celled secretory head, a unicellular stalk, and an also unicellular epidermal foot. The essential oil of the winter leaves is mainly composed of linalool (42.4%, thymol (7.0%, p-cymene (5.8%, β-caryophyllene (5.7%, borneol (5.6%, and terpinen-4-ol (4.8%. The oil of the summer leaves is principally constituted of p-cymene (25.0%, linalool (19.1%, terpinen-4-ol (8.5% and borneol (8.3%. Non-glandular hairs proliferate in the summer leaves. They are conical in shape and consist of one basal epidermal cell and one apical pointed cell. Glandular and non-glandular hairs are implicated in the chemical and mechanical defense of the plant, respectively.

  11. Urbanization and the incidence of abnormalities of squamous and glandular epithelium of the cervix

    NARCIS (Netherlands)

    Boon, ME; Claasen, HHV; van Westering, RP; Kok, LP

    2003-01-01

    BACKGROUND. The large data bases of the Dutch cervical screening program can be exploited to establish the relation between urbanization and the incidence of abnormalities of the squamous and glandular epithelium, including mild or greater changes of the squamous and glandular epithelium of the cerv

  12. Retinol oxidation to retinoic acid in human thyroid glandular cells.

    Science.gov (United States)

    Taibi, Gennaro; Gueli, Maria Concetta; Nicotra, Concetta M A; Cocciadiferro, Letizia; Carruba, Giuseppe

    2014-12-01

    Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia. PMID:24506204

  13. THE AVERAGE ANNUAL EFFECTIVE DOSES FOR THE POPULATION IN THE SETTLEMENTS OF THE RUSSIAN FEDERATION ATTRIBUTED TO ZONES OF RADIOACTIVE CONTAMINATION DUE TO THE CHERNOBYL ACCIDENT (FOR ZONATION PURPOSES, 2014

    Directory of Open Access Journals (Sweden)

    G. Ja. Bruk

    2015-01-01

    Full Text Available The Chernobyl accident in 1986 is one of the most large-scale radiation accidents in the world. It led to radioactive contamination of large areas in the European part of the Russian Federation and at the neighboring countries. Now, there are more than 4000 settlements with the total population of 1.5 million in the radioactively contaminated areas of the Russian Federation. The Bryansk region is the most intensely contaminated region. For example, the Krasnogorskiy district still has settlements with the level of soil contamination by cesium-137 exceeding 40 Cu/km2. The regions of Tula, Kaluga and Orel are also significantly affected. In addition to these four regions, there are 10 more regions with the radioactively contaminated settlements. After the Chernobyl accident, the affected areas were divided into zones of radioactive contamination. The attribution of the settlements to a particular zone is determined by the level of soil contamination with 137Cs and by a value of the average annual effective dose that could be formed in the absence of: 1 active measures for radiation protection, and 2 self-limitation in consumption of the local food products. The main regulatory document on this issue is the Federal law № 1244-1 (dated May, 15,1991 «On the social protection of the citizens who have been exposed to radiation as a result of the accident at the Chernobyl nuclear power plant». The law extends to the territories, where, since 1991: – The average annual effective dose for the population exceeds 1 mSv (the value of effective dose that could be formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products; – Soil surface contamination with cesium-137 exceeds 1 Cu/km2. The paper presents results of calculations of the average effective doses in 2014. The purpose was to use the dose values (SGED90 in zonation of contaminated territories. Therefore, the

  14. DICOM organ dose does not accurately represent calculated dose in mammography

    Science.gov (United States)

    Suleiman, Moayyad E.; Brennan, Patrick C.; McEntee, Mark F.

    2016-03-01

    This study aims to analyze the agreement between the mean glandular dose estimated by the mammography unit (organ dose) and mean glandular dose calculated using Dance et al published method (calculated dose). Anonymised digital mammograms from 50 BreastScreen NSW centers were downloaded and exposure information required for the calculation of dose was extracted from the DICOM header along with the organ dose estimated by the system. Data from quality assurance annual tests for the included centers were collected and used to calculate the mean glandular dose for each mammogram. Bland-Altman analysis and a two-tailed paired t-test were used to study the agreement between calculated and organ dose and the significance of any differences. A total of 27,869 dose points from 40 centers were included in the study, mean calculated dose and mean organ dose (+/- standard deviation) were 1.47 (+/-0.66) and 1.38 (+/-0.56) mGy respectively. A statistically significant 0.09 mGy bias (t = 69.25; pAltman analysis, which indicates a small yet highly significant difference between the two means. The use of organ dose for dose audits is done at the risk of over or underestimating the calculated dose, hence, further work is needed to identify the causal agents for differences between organ and calculated doses and to generate a correction factor for organ dose.

  15. Optimal Dose of Vitamin D3 400 I.U. for Average Adults has A Significant Anti-Cancer Effect, While Widely Used 2000 I.U. or Higher Promotes Cancer: Marked Reduction of Taurine & 1α, 25(OH)2D3 Was Found In Various Cancer Tissues and Oral Intake of Optimal Dose of Taurine 175mg for Average Adults, Rather Than 500mg, Was Found to Be A New Potentially Safe and More Effective Method of Cancer Treatment.

    Science.gov (United States)

    Omura, Yoshiaki; Lu, Dominic; Jones, Marilyn K; Nihrane, Abdallah; Duvvi, Harsha; Yapor, Dario; Shimotsuura, Yasuhiro; Ohki, Motomu

    2016-01-01

    During the past 10 years, the author had found that the optimal dose of Vitamin D3 400 I.U. has safe & effective anticancer effects, while commonly used 2000-5000 I.U. of Vit. D3 often creates a 2-3 time increase in cancer markers. We examined the concentration of Taurine in normal internal organs and in cancer using Bi-Digital O-Ring Test. We found that Taurine levels in normal tissue are 4-6ng. But, the amount of Taurine of average normal value of 5.0-5.25ng was strikingly reduced to 0.0025-0.0028ng in this study of several examples in adenocarcinomas of the esophagus, stomach, pancreas, colon, prostate, and lung, as well as breast cancer. The lowest Taurine levels of 0.0002-0.0005ng were found in so called Zika virus infected babies from Brazil with microcephaly. While Vitamin D3 receptor stimulant 1α, 25 (OH)2D3 in normal tissues was 0.45-0.53ng, they were reduced to 0.025-0.006ng in cancers (1/100th-1/200th of normal value), particularly in various adenocarcinomas. All of these adenocarcinomas had about 1500ng HPV-16 viral infection. In 500 breast cancers, about 97% had HPV-16. The optimal dose of Taurine for average adult has been found to be about 175mg, rather than the widely used 500mg. In addition, since Taurine is markedly reduced to close to 1/1000th-1/2000th of its normal value in these cancer tissues, we examined the effect of the optimal dose of Taurine on cancer patients. Optimal dose of Taurine produced a very significant decrease in cancer-associated parameters, such as Oncogene C-fosAb2 & Integrin α5β1 being reduced to less than 1/1,000th, and 8-OH-dG (which increases in the presence of DNA mutation) reduced to less than 1/10th. The optimal dose of Taurine 175mg for average adult various cancer patient 3 times a day alone provide beneficial effects with very significant anti-cancer effects with strikingly increased urinary excretion of bacteria, viruses, & funguses, asbestos, toxic metals & other toxic substances. However, optimal doses of

  16. Optimal Dose of Vitamin D3 400 I.U. for Average Adults has A Significant Anti-Cancer Effect, While Widely Used 2000 I.U. or Higher Promotes Cancer: Marked Reduction of Taurine & 1α, 25(OH)2D3 Was Found In Various Cancer Tissues and Oral Intake of Optimal Dose of Taurine 175mg for Average Adults, Rather Than 500mg, Was Found to Be A New Potentially Safe and More Effective Method of Cancer Treatment.

    Science.gov (United States)

    Omura, Yoshiaki; Lu, Dominic; Jones, Marilyn K; Nihrane, Abdallah; Duvvi, Harsha; Yapor, Dario; Shimotsuura, Yasuhiro; Ohki, Motomu

    2016-01-01

    During the past 10 years, the author had found that the optimal dose of Vitamin D3 400 I.U. has safe & effective anticancer effects, while commonly used 2000-5000 I.U. of Vit. D3 often creates a 2-3 time increase in cancer markers. We examined the concentration of Taurine in normal internal organs and in cancer using Bi-Digital O-Ring Test. We found that Taurine levels in normal tissue are 4-6ng. But, the amount of Taurine of average normal value of 5.0-5.25ng was strikingly reduced to 0.0025-0.0028ng in this study of several examples in adenocarcinomas of the esophagus, stomach, pancreas, colon, prostate, and lung, as well as breast cancer. The lowest Taurine levels of 0.0002-0.0005ng were found in so called Zika virus infected babies from Brazil with microcephaly. While Vitamin D3 receptor stimulant 1α, 25 (OH)2D3 in normal tissues was 0.45-0.53ng, they were reduced to 0.025-0.006ng in cancers (1/100th-1/200th of normal value), particularly in various adenocarcinomas. All of these adenocarcinomas had about 1500ng HPV-16 viral infection. In 500 breast cancers, about 97% had HPV-16. The optimal dose of Taurine for average adult has been found to be about 175mg, rather than the widely used 500mg. In addition, since Taurine is markedly reduced to close to 1/1000th-1/2000th of its normal value in these cancer tissues, we examined the effect of the optimal dose of Taurine on cancer patients. Optimal dose of Taurine produced a very significant decrease in cancer-associated parameters, such as Oncogene C-fosAb2 & Integrin α5β1 being reduced to less than 1/1,000th, and 8-OH-dG (which increases in the presence of DNA mutation) reduced to less than 1/10th. The optimal dose of Taurine 175mg for average adult various cancer patient 3 times a day alone provide beneficial effects with very significant anti-cancer effects with strikingly increased urinary excretion of bacteria, viruses, & funguses, asbestos, toxic metals & other toxic substances. However, optimal doses of

  17. Evaluation of multiple scan average dose (MSAD) levels in computerized tomography in Minas Gerais state, Brazil; Avaliacao dos niveis de dose media em cortes multiplos (MSAD) em tomografia computadorizada no estado de Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Thessa C., E-mail: alonso@cdtn.br [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Vieira, Leandro de A.; Barbosa, Nayra V.; Oliveira, Jeyselaine R. de; Cesar, Adriana C.Z. [Secretaria de Vigilancia Sanitaria de Minas Gerais, Belo Horizonte, MG (Brazil); Silva, Teogenes A. da [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear. Programa de Ciencias e Tecnicas Nucleares

    2014-07-01

    Computed Tomography (CT) grows every year and is a diagnostic method that has revolutionized radiology with advances in procedures for obtaining image. However, the indiscriminate use of this method generates relatively high doses in patients. The diagnostic reference levels (DRLs) is a practical tool to promote the evaluation of existing protocols. The optimization and the periodic review of the protocols are important to balance the risk of radiation. The present study aims to conduct a survey of levels of MSAD of Minas Gerais following the procedures recommended by current Brazilian law. (author)

  18. Influence of breast composition and interseed attenuation in dose calculations for post-implant assessment of permanent breast 103Pd seed implant

    Science.gov (United States)

    Afsharpour, Hossein; Pignol, Jean-Philippe; Keller, Brian; Carrier, Jean-François; Reniers, Brigitte; Verhaegen, Frank; Beaulieu, Luc

    2010-08-01

    The impact of tissue heterogeneity and interseed attenuation is studied in post-implant evaluation of five clinical permanent breast 103Pd seed implants using the Monte Carlo (MC) dose calculation method. Dose metrics for the target (PTV) as well as an organ at risk (skin) are used to visualize the differences between a TG43-like MC method and more accurate MC methods capable of considering the breast tissue heterogeneity as well as the interseed attenuation. PTV dose is reduced when using a breast tissue model instead of water in MC calculations while the dose to the skin is increased. Furthermore, we investigate the effect of varying the glandular/adipose proportion of the breast tissue on dose distributions. The dose to the PTV (skin) decreases (increases) with the increasing adipose proportion inside the breast. In a complete geometry and compared to a TG43-like situation, the average PTV D90 reduction varies from 3.9% in a glandular breast to 35.5% when the breast consists entirely of adipose. The skin D10 increases by 28.2% in an entirely adipose breast. The results of this work show the importance of an accurate and patient-dependent breast tissue model to be used in the dosimetry for this kind of low energy implant.

  19. Influence of breast composition and interseed attenuation in dose calculations for post-implant assessment of permanent breast {sup 103}Pd seed implant

    Energy Technology Data Exchange (ETDEWEB)

    Afsharpour, Hossein; Beaulieu, Luc [Departement de Radio-Oncologie et Centre de recherche en cancerologie de l' Universite Laval, Centre Hospitalier Universitaire de Quebec, 11 Cote du Palais, Quebec, QC G1R 2J6 (Canada); Pignol, Jean-Philippe; Keller, Brian [Department of Radiation Oncology, Sunnybrook and Women' s Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Carrier, Jean-Francois [Departement de Radiologie, Radio-Oncologie et Medecine Nucleaire, Hopital Notre-Dame de CHUM, 1560 Sherbrooke E, Montreal, QC H2L 4M1 (Canada); Reniers, Brigitte; Verhaegen, Frank, E-mail: beaulieu@phy.ulaval.c [Department of Radiation Oncology (MAASTRO), GROW, University Hospital Maastricht, Maastricht (Netherlands)

    2010-08-21

    The impact of tissue heterogeneity and interseed attenuation is studied in post-implant evaluation of five clinical permanent breast {sup 103}Pd seed implants using the Monte Carlo (MC) dose calculation method. Dose metrics for the target (PTV) as well as an organ at risk (skin) are used to visualize the differences between a TG43-like MC method and more accurate MC methods capable of considering the breast tissue heterogeneity as well as the interseed attenuation. PTV dose is reduced when using a breast tissue model instead of water in MC calculations while the dose to the skin is increased. Furthermore, we investigate the effect of varying the glandular/adipose proportion of the breast tissue on dose distributions. The dose to the PTV (skin) decreases (increases) with the increasing adipose proportion inside the breast. In a complete geometry and compared to a TG43-like situation, the average PTV D{sub 90} reduction varies from 3.9% in a glandular breast to 35.5% when the breast consists entirely of adipose. The skin D{sub 10} increases by 28.2% in an entirely adipose breast. The results of this work show the importance of an accurate and patient-dependent breast tissue model to be used in the dosimetry for this kind of low energy implant.

  20. Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias

    DEFF Research Database (Denmark)

    Holl, Katsiaryna; Nowakowski, Andrzej M; Powell, Ned;

    2015-01-01

    Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providi...

  1. Diagnostic and therapeutic dilemma associated with atypical glandular cells on liquid-based cervical cytology.

    LENUS (Irish Health Repository)

    Chummun, K

    2012-12-01

    In 2008, the management of women in Ireland with atypical glandular cells changed to immediate referral to colposcopy. The optimal management of these women is unclear. A balance between the detection of occult disease and overtreatment is required.

  2. Capitate glandular trichomes of Paragutzlaffia henryi harbor new phytotoxic labdane diterpenoids.

    Science.gov (United States)

    Wang, Ying; Luo, Shi-Hong; Hua, Juan; Liu, Yan; Jing, Shu-Xi; Li, Xiao-Nian; Li, Sheng-Hong

    2015-11-18

    The morphology and chemical profile of the capitate glandular trichomes (CGTs) of Paragutzlaffia henryi (Acanthaceae) were investigated. Four new labdane diterpenoids named paraguhenryisins A-D (1-4), together with the known physacoztomatin (5), were localized to the CGTs using laser microdissection coupled with cryogenic (1)H NMR and HPLC analyses and were traced and isolated from the CGT extract of inflorescences. Their structures were determined by spectroscopic methods and single-crystal X-ray diffraction. Bioassays indicated significant inhibitory effect for these diterpenoids on Arabidopsis thaliana seed germination and seedling root elongation. The most potent inhibitor, paraguhenryisin C (3), was interestingly detected in both the rhizosphere soil and water rinsed inflorescences extract of P. henryi but not the roots, with average contents in the rhizosphere soil relevant to its phytotoxic EC50 values. These results suggested that phytotoxic labdane diterpenoids in the CGTs might be released into the environment as a defensive measure for P. henryi against other competitive plants. PMID:26513276

  3. Experimental evaluation of the image quality and dose in digital mammography: Influence of x-ray spectrum

    Science.gov (United States)

    Tomal, A.; Perez, A. M. M. M.; Silva, M. C.; Poletti, M. E.

    2015-11-01

    In this work, we studied experimentally the influence of x-ray spectrum on the contrast-to-noise ratio (CNR) and the average glandular dose (MDG) for two digital mammography systems: Senographe 2000D (GE Medical Systems) and Lorad Selenia (Hologic), with indirect and direct detector imaging technology, respectively. CNR and MGD were determined using PMMA phantoms simulating breasts with thicknesses of 4 cm and 6 cm. All available anode/filter combinations of the systems were evaluated for a wide range of tube voltages values. Results indicated that the Rh/Rh combination provides the highest image quality with the lower mean glandular dose for the Senographe 2000D system. For the Lorad Selenia system, the W/Ag combination at 30 kV showed the best performance, in terms of dose saving and image quality improvement in relation to all tube voltage range. The comparison between the optimal x-ray spectra and those selected by the AEC mode showed that this automatic selection mechanism could be readjusted to optimize the relationship between image quality and dose.

  4. Caracterização e ontogenia dos tricomas glandulares de Ocimum selloi Benth. - Lamiaceae Characterization and ontogeny of the glandular trichomes of Ocimum selloi Benth. (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Letícia de Almeida Gonçalves

    2010-12-01

    Full Text Available Ocimum selloi Benth. (Lamiaceae é uma espécie nativa da América do Sul e na medicina popular tem sido usada devido suas propriedades analgésica, anti-inflamatória e antiespasmódica. O objetivo do presente trabalho foi identificar os tipos de tricomas glandulares que ocorrem nos órgãos vegetativos e reprodutivos de O. selloi e determinar a ontogenia desses tricomas. Ramos laterais em início de formação, folhas totalmente expandidas, flores em diferentes estádios de diferenciação, amostras de caule e do eixo das inflorescências foram analisados em microscopias de luz e eletrônica de varredura. Tricomas glandulares do tipo peltado e capitado subséssil foram observados no caule, nas folhas, no eixo da inflorescência e na superfície adaxial das sépalas. Nas sépalas foi encontrado, além dos tricomas secretores peltados e capitados subsésseis, o tricoma glandular capitado pedunculado. A ontogenia inicia-se com a expansão de uma célula protodérmica que, de acordo com a seqüência de divisões periclinais e anticlinais (ora simétricas, ora assimétricas, dá origem aos tricomas. A diferenciação dos tricomas glandulares peltados e capitados não é sincrônica e ocorre muito cedo no desenvolvimento da folha, do caule e do eixo floral.Ocimum selloi Benth. (Lamiaceae is native to South America and in traditional medicine has been used due to its analgesic, anti-inflammatory, and antispasmodic properties. The aim of this study was to identify the types of glandular trichomes that occur on the vegetative and reproductive organs of O. selloi and to determine trichome ontogeny. Lateral branches at the initial formation phase, fully opened leaves, flowers at different differentiation stages, and stem and inflorescence axes were analyzed under light and scanning electron microscopy. Glandular trichomes of the peltate and subsessile capitate types were observed on the stem, leaves, inflorescence axis and the adaxial surface of the

  5. Next generation sequencing unravels the biosynthetic ability of Spearmint (Mentha spicata) peltate glandular trichomes through comparative transcriptomics

    OpenAIRE

    Jin, Jingjing; Panicker, Deepa; Wang, Qian; Kim, Mi Jung; Liu, Jun; Yin, Jun-Lin; Wong, Limsoon; Jang, In-Cheol; Chua, Nam-Hai; Sarojam, Rajani

    2014-01-01

    Background Plant glandular trichomes are chemical factories with specialized metabolic capabilities to produce diverse compounds. Aromatic mint plants produce valuable essential oil in specialised glandular trichomes known as peltate glandular trichomes (PGT). Here, we performed next generation transcriptome sequencing of different tissues of Mentha spicata (spearmint) to identify differentially expressed transcripts specific to PGT. Our results provide a comprehensive overview of PGT’s dynam...

  6. Higher glandular trichome density in tomato leaflets and repellence to spider mites

    Energy Technology Data Exchange (ETDEWEB)

    Maluf, Wilson Roberto; Inoue, Irene Fumi; Ferreira, Raphael de Paula Duarte; Gomes, Luiz Antonio Augusto [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Agricultura]. E-mail: wrmaluf@ufla.br; fuminoue@yahoo.com.br; raphaelufla@yahoo.com.br; laagomes@ufla.br; Castro, Evaristo Mauro de [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Biologia]. E-mail: emcastro@ufla.br; Cardoso, Maria das Gracas [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Quimica]. E-mail: mcardoso@ufla.br

    2007-09-15

    The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII), and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI) decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence) to spider mites. (author)

  7. Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

    DEFF Research Database (Denmark)

    husted, Louise; Jensen, Tim Kåre; Olsen, Susanne N.;

    2010-01-01

    Background: The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses. Results: Stomach lesions, as well as normal...... by cloning and sequencing. Mucosal lesions were found in 36/63 stomachs and included hyperplastic rugae, polypoid structures and focal erosions. None of the samples were tested positive for urease activity or for FISH using the Helicobacter genus specific probe. In samples of lesions, as well as normal...... faecium. The Enterococcus were found colonising the mucosal surface, while E. fergusonii organisms were also demonstrated intraepithelial. Conclusion: Gastric Helicobacter spp. could not be verified as being involved in lesions of the glandular stomach of the horse. Since E. fergusonii has been described...

  8. DICOM organ dose does not accurately represent calculated dose in mammography

    Science.gov (United States)

    Suleiman, Moayyad E.; Brennan, Patrick C.; McEntee, Mark F.

    2016-03-01

    This study aims to analyze the agreement between the mean glandular dose estimated by the mammography unit (organ dose) and mean glandular dose calculated using Dance et al published method (calculated dose). Anonymised digital mammograms from 50 BreastScreen NSW centers were downloaded and exposure information required for the calculation of dose was extracted from the DICOM header along with the organ dose estimated by the system. Data from quality assurance annual tests for the included centers were collected and used to calculate the mean glandular dose for each mammogram. Bland-Altman analysis and a two-tailed paired t-test were used to study the agreement between calculated and organ dose and the significance of any differences. A total of 27,869 dose points from 40 centers were included in the study, mean calculated dose and mean organ dose (+/- standard deviation) were 1.47 (+/-0.66) and 1.38 (+/-0.56) mGy respectively. A statistically significant 0.09 mGy bias (t = 69.25; p<0.0001) with 95% limits of agreement between calculated and organ doses ranging from -0.34 and 0.52 were shown by Bland-Altman analysis, which indicates a small yet highly significant difference between the two means. The use of organ dose for dose audits is done at the risk of over or underestimating the calculated dose, hence, further work is needed to identify the causal agents for differences between organ and calculated doses and to generate a correction factor for organ dose.

  9. Biochemical and histochemical localization of monoterpene biosynthesis in the glandular trichomes of spearmint (Mentha spicata)

    Energy Technology Data Exchange (ETDEWEB)

    Gershenzon, J.; Maffei, M.; Croteau, R. (Washington State Univ., Pullman (USA))

    1989-04-01

    The primary monoterpene accumulated in the glandular trichomes of spearmint (Mentha spicata) is the ketone (-)-carvone which is formed by cyclization of the C{sub 10} isoprenoid intermediate geranyl pyrophosphate to the olefin (-)-limonene, hydroxylation to (-)-trans-carveol and subsequent dehydrogenation. Selective extraction of the contents of the glandular trichomes indicated that essentially all of the cyclase and hydroxylase activities resided in these structures, whereas only about 30% of the carveol dehydrogenase was located here with the remainder located in the rest of the leaf. This distribution of carveol dehydrogenase activity was confirmed by histochemical methods. Electrophoretic analysis of the partially purified carveol dehydrogenase from extracts of both the glands and the leaves following gland removal indicated the presence of a unique carveol dehydrogenase species in the glandular trichomes, suggesting that the other dehydrogenase found throughout the leaf probably utilizes carveol only as an adventitious substrate. These results demonstrate that carvone biosynthesis takes place exclusively in the glandular trichomes in which this natural product accumulates.

  10. Peltate glandular trichomes of Colquhounia seguinii harbor new defensive clerodane diterpenoids.

    Science.gov (United States)

    Li, Chun-Huan; Liu, Yan; Hua, Juan; Luo, Shi-Hong; Li, Sheng-Hong

    2014-09-01

    Glandular trichomes produce a wide variety of secondary metabolites that are considered as major defensive chemicals against herbivore attack. The morphology and secondary metabolites of the peltate glandular trichomes of a lianoid Labiatae, Colquhounia seguinii Vaniot, were investigated. Three new clerodane diterpenoids, seguiniilactones A-C (1-3), were identified through precise trichome collection with laser microdissection, metabolic analysis with ultra performance liquid chromatography-tandem mass spectrometer, target compound isolation with classical phytochemical techniques, structure elucidation with spectroscopic methods. All compounds showed significant antifeedant activity against a generalist plant-feeding insect Spodoptera exigua. Seguiniilactone A (1) was approximately 17-fold more potent than the commercial neem oil. α-Substituted α,β-unsaturated γ-lactone functionality was found to be crucial for strong antifeedant activity of this class of compounds. Quantitative results indicated that the levels of these compounds in the peltate glandular trichomes and leaves were sufficiently high to deter the feeding by generalist insects. Moderate antifungal activity was observed for seguiniilactone C (3) against six predominant fungal species isolated from the diseased leaves of C. seguinii, while seguiniilactones A and B were generally inactive. These findings suggested that seguiniilactones A-C might be specialized secondary metabolites in peltate glandular trichomes for the plant defense against insect herbivores and pathogens. PMID:25048077

  11. Expression of nucleophosmin in glandular epithelium of non-pregnant human endometrium during the menstrual cycle

    Institute of Scientific and Technical Information of China (English)

    KUANG Ye; XU Peng; WEN Hai-xia; KONG Xian-chao; GUAN Li-li; LI Pei-ling

    2011-01-01

    Background Nucleophosmin plays a critical role in embryonic development. This study aimed to examine the expression pattern of nucleophosmin in glandular epithelium of human endometrium during the menstrual cycle.Methods Endometrial tissues used for this study were obtained from 46 non-pregnant patients who underwent hysterectomy which had been performed to treat benign diseases. Nucleophosmin expression was assessed by in situ hybridization and immunohistochemistry.Results At the early-, mid- and late-proliferative phase, nucleophosmin mRNA was highly expressed in glandular epithelium of human endometrium. At the secretory phase, the expression of nucleophosmin mRNA was reduced in glandular epithelium in early-secretory phase, and the expression in mid- and late-secretory phases was not detected.Similarly, nucleophosmin protein was strongly expressed in endometrial glands throughout the proliferative phase, but was gradually reduced during secretory phase.Conclusion Nucleophosmin mRNA and protein are expressed in glandular epithelium of human endometrium throughout the menstrual cycle.

  12. Peltate glandular trichomes of Colquhounia seguinii harbor new defensive clerodane diterpenoids

    Institute of Scientific and Technical Information of China (English)

    Chun-Huan Li; Yan Liu; Juan Hua; Shi-Hong Luo; Sheng-Hong Li

    2014-01-01

    Glandular trichomes produce a wide variety of secondary metabolites that are considered as major defen-sive chemicals against herbivore attack. The morphology and secondary metabolites of the peltate glandular trichomes of a lianoid Labiatae, Colquhounia seguinii Vaniot, were investigated. Three new clerodane diterpenoids, seguiniilac-tones A-C (1-3), were identified through precise trichome collection with laser microdissection, metabolic analysis with ultra performance liquid chromatography-tandem mass spectrometer, target compound isolation with classical phytochemical techniques, structure elucidation with spec-troscopic methods. All compounds showed significant antifeedant activity against a generalist plant-feeding insect Spodoptera exigua. Seguiniilactone A (1) was approxi-mately 17-fold more potent than the commercial neem oil. a-Substituted a,b-unsaturated g-lactone functionality was found to be crucial for strong antifeedant activity of this class of compounds. Quantitative results indicated that the levels of these compounds in the peltate glandular trichomes and leaves were sufficiently high to deter the feeding by generalist insects. Moderate antifungal activity was ob-served for seguiniilactone C (3) against six predominant fungal species isolated from the diseased leaves of C. seguinii, while seguiniilactones A and B were generally inactive. These findings suggested that seguiniilactones A-C might be specialized secondary metabolites in peltate glandular trichomes for the plant defense against insect herbivores and pathogens.

  13. Honey bee males and queens use glandular secretions to enhance sperm viability before and after storage

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Boomsma, Jacobus Jan; Baer, Boris

    2009-01-01

    Internal fertilization requires live sperm to be transferred from male to female before egg fertilization. Both males and females assist the insemination process by providing sperm with glandular secretions, which have been inferred to contain subsets of proteins that maintain sperm viability. He...

  14. Engineering of Tomato Glandular Trichomes for the Production of Specialized Metabolites.

    Science.gov (United States)

    Kortbeek, R W J; Xu, J; Ramirez, A; Spyropoulou, E; Diergaarde, P; Otten-Bruggeman, I; de Both, M; Nagel, R; Schmidt, A; Schuurink, R C; Bleeker, P M

    2016-01-01

    Glandular trichomes are specialized tissues on the epidermis of many plant species. On tomato they synthesize, store, and emit a variety of metabolites such as terpenoids, which play a role in the interaction with insects. Glandular trichomes are excellent tissues for studying the biosynthesis of specialized plant metabolites and are especially suitable targets for metabolic engineering. Here we describe the strategy for engineering tomato glandular trichomes, first with a transient expression system to provide proof of trichome specificity of selected promoters. Using microparticle bombardment, the trichome specificity of a terpene-synthase promoter could be validated in a relatively fast way. Second, we describe a method for stable expression of genes of interest in trichomes. Trichome-specific expression of another terpene-synthase promoter driving the yellow-fluorescence protein-gene is presented. Finally, we describe a case of the overexpression of farnesyl diphosphate synthase (FPS), specifically in tomato glandular trichomes, providing an important precursor in the biosynthetic pathway of sesquiterpenoids. FPS was targeted to the plastid aiming to engineer sesquiterpenoid production, but interestingly leading to a loss of monoterpenoid production in the transgenic tomato trichomes. With this example we show that trichomes are amenable to engineering though, even with knowledge of a biochemical pathway, the result of such engineering can be unexpected. PMID:27480691

  15. Caracterização e ontogenia dos tricomas glandulares de Ocimum selloi Benth. - Lamiaceae Characterization and ontogeny of the glandular trichomes of Ocimum selloi Benth. (Lamiaceae)

    OpenAIRE

    Letícia Almeida Gonçalves; Aristéa Alves Azevedo; Wagner Campos Otoni

    2010-01-01

    Ocimum selloi Benth. (Lamiaceae) é uma espécie nativa da América do Sul e na medicina popular tem sido usada devido suas propriedades analgésica, anti-inflamatória e antiespasmódica. O objetivo do presente trabalho foi identificar os tipos de tricomas glandulares que ocorrem nos órgãos vegetativos e reprodutivos de O. selloi e determinar a ontogenia desses tricomas. Ramos laterais em início de formação, folhas totalmente expandidas, flores em diferentes estádios de diferenciação, amostras de ...

  16. Forming an opinion on the average individual effective dose concept where medical imaging is concerned, and of its use in the modelling of radio-induced cancer risk?; Que faut-il penser de la notion de dose efficace individuelle moyenne pour les expositions medicales et de son utilisation dans la modelisation du risque de cancers radio-induits?

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Yves-Sebastien [Departement Scanner-IRM, Hopital prive de Parly2, 21 rue Moxouris, 78150 Le Chesnay (France)

    2011-07-15

    The IRSN/INVS report on 'Ionizing-radiation-exposure of the French population in connection with medical diagnostic acts in 2007' provides a very useful tool for the analysis of medical exposure, in particular through the raw data it contains about exposure resulting from the various usual techniques. However, this report also gives an estimate of the 'average individual effective dose', which is a misleading notion as it could result in a false assessment of the number of deadly cancers induced by medical exposure. In fact, medical exposure to ionizing radiation is very heterogeneous and varies according to the age, greatly increasing for the eldest patients, whose stochastic risk is, conversely, no longer significant. (author)

  17. Evaluation of parameters of the HDV (V20 and dose average) in radiotherapy of lung cancer with lung volumes design adapted compounds (ITV); Evaluacion de parametros del HDV (V20 Y Dmed) en radioterapia adaptada de cancer de pulmon con diseno de volumenes pulmonares compuestos (ITV)

    Energy Technology Data Exchange (ETDEWEB)

    Monroy Anton, J. L.; Solar Tortosa, M.; Lopez Munoz, M.; Navarro Bergada, A.; Estornell Gualde, M. A.; Melchor Iniguez, M.

    2013-07-01

    Our objective was to evaluate the V20 parameters and dose average compared to a single lung volume designed with a CT study in normal breathing of the patient and the corresponding to a lung volume composed, designed from three studies of CT in different phases of the respiratory cycle. Check if there are important differences in these cases that determine the necessity of creating a composite lung volume to evaluate dose volume histogram. (Author)

  18. The relationship between compression force, image quality and radiation dose in mammography

    Directory of Open Access Journals (Sweden)

    A Korf

    2009-11-01

    Full Text Available Background. Mammography aims to obtain mammograms of best possible image quality with least possible radiation dose.1 Theoretically, an increase in breast compression gives a reduction in thickness, without changing the density, resulting in improved image quality and reduced radiation dose. Aim.\tThis study aims to investigate the relationship between compression force, phantom thickness, image quality and radiation dose. The existence of a compression point beyond which increased compression gives a change in density rather than thickness is also considered. Method. Image quality is assessed with a contrast-detail phantom within Superflab phantom on a computed radiography (CR mammography unit using automatic exposure control (AEC. Image quality is determined by visual inspection and image quality figure (IQF scoring. The effect of compression and lesion depth on image quality is determined. Entrance and exit doses are calculated. The relationship between entrance dose, compression and thickness is investigated, as is the existence of a compression point beyond which a change in phantom density occurs. The average glandular dose (AGD is calculated from the scanning average level (SAL and logarithmic mean (LgM according to Koen et al,2 and compared to the allowable limit. Results.\tThe geometry effect was not observed. An improvement in image quality with increased compression was found. Entrance dose did decrease with increased compression. This trend was not observed with exit dose as AEC was used and exit dose was calculated from SAL values. The “change-in-density” point of compression was determined. Both LgM and SAL could be used successfully for AGD calculation.

  19. Histological Correlation of Glandular Abnormalities in Cervical Liquid-Based Cytology

    Directory of Open Access Journals (Sweden)

    Yosuke Kawakami

    2011-01-01

    Full Text Available Conventional Papanicolaou smear method is still commonly used for cervical cancer screening in Japan, despite the liquid-based cytology (LBC that has become a global tendency in the world recently. One of the obstacles in the way of popularization of this method seems to be the confusion as to diagnosis upon cervical glandular lesions. We performed comparison study between LBC and conventional Papanicolaou smear about cytological diagnosis using split-sample method in 4522 patients. In 13 cases analyses, which were reported with either AGC or adenocarcinoma by either method, LBC tends to be milder than that by conventional smear, however, the credibility of LBC is considered to be near to that of conventional smear with regard to screening for glandular abnormalities. These results indicate that cervical cancer screening should shift to LBC under the enough experience and appropriate dealing with the cytological diagnosis.

  20. Higher glandular trichome density in tomato leaflets and repellence to spider mites Alta densidade de tricomas glandulares em tomateiro e aumento da repelência a ácaros rajados

    Directory of Open Access Journals (Sweden)

    Wilson Roberto Maluf

    2007-09-01

    Full Text Available The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII, and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence to spider mites.O objetivo deste trabalho foi avaliar a eficiência da seleção para maior densidade de tricomas glandulares na resistência (repelência ao ácaro Tetranychus urticae, em populações de tomate derivadas do cruzamento interespecífico Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Foram avaliados 19 genótipos quanto à densidade de tricomas, que incluíram 12 derivados de populações avançadas de retrocruzamentos, obtidos a partir do cruzamento original L. esculentum x L. hirsutum var. glabratum PI 134417. Nas faces abaxial e adaxial dos folíolos, realizaram-se as contagens e os tricomas foram classificados em glandulares tipo IV e VI, outros glandulares (tipo I e VII e não glandulares. A repelência aos ácaros foi medida pela distância média, percorrida pelo

  1. Glandular odontogenic cyst associated with ameloblastoma occupying maxillary sinus: A rare case report

    Directory of Open Access Journals (Sweden)

    Riaz Abdulla

    2016-01-01

    Full Text Available The glandular odontogenic cyst (GOC is a rare entity with around 111 cases available in the literature. The occurrence of GOC with ameloblastoma as a collision tumor is rarest, and such a case poses problems in the form of diagnostic dilemma and management. The present case report describes and discusses a rare case of GOC with ameloblastomatous component occurring in right maxilla of a 54-year-old male patient with a chief complaint of painful swelling.

  2. Long acting β2-agonist and corticosteroid restore airway glandular cell function altered by bacterial supernatant

    Directory of Open Access Journals (Sweden)

    Nawrocki-Raby Béatrice

    2010-01-01

    Full Text Available Abstract Background Staphylococcus aureus releases virulence factors (VF that may impair the innate protective functions of airway cells. The aim of this study was to determine whether a long-acting β2 adrenergic receptor agonist (salmeterol hydroxynaphthoate, Sal combined with a corticosteroid (fluticasone propionate, FP was able to regulate ion content and cytokine expression by airway glandular cells after exposure to S. aureus supernatant. Methods A human airway glandular cell line was incubated with S. aureus supernatant for 1 h and then treated with the combination Sal/FP for 4 h. The expression of actin and CFTR proteins was analyzed by immunofluorescence. Videomicroscopy was used to evaluate chloride secretion and X-ray microanalysis to measure the intracellular ion and water content. The pro-inflammatory cytokine expression was assessed by RT-PCR and ELISA. Results When the cells were incubated with S. aureus supernatant and then with Sal/FP, the cellular localisation of CFTR was apical compared to the cytoplasmic localisation in cells incubated with S. aureus supernatant alone. The incubation of airway epithelial cells with S. aureus supernatant reduced by 66% the chloride efflux that was fully restored by Sal/FP treatment. We also observed that Sal/FP treatment induced the restoration of ion (Cl and S and water content within the intracellular secretory granules of airway glandular cells and reduced the bacterial supernatant-dependent increase of pro-inflammatory cytokines IL8 and TNFα. Conclusions Our results demonstrate that treatment with the combination of a corticosteroid and a long-acting β2 adrenergic receptor agonist after bacterial infection restores the airway glandular cell function. Abnormal mucus induced by defective ion transport during pulmonary infection could benefit from treatment with a combination of β2 adrenergic receptor agonist and glucocorticoid.

  3. Histological Correlation of Glandular Abnormalities in Cervical Liquid-Based Cytology

    OpenAIRE

    Yosuke Kawakami; Tamaki Toda; Toshinao Nishimura; Junichi Sakane; Kazuya Kuraoka; Kazuhiro Takehara; Tomoya Mizunoe; Kiyomi Taniyama

    2011-01-01

    Conventional Papanicolaou smear method is still commonly used for cervical cancer screening in Japan, despite the liquid-based cytology (LBC) that has become a global tendency in the world recently. One of the obstacles in the way of popularization of this method seems to be the confusion as to diagnosis upon cervical glandular lesions. We performed comparison study between LBC and conventional Papanicolaou smear about cytological diagnosis using split-sample method in 4522 patients. In 13 ca...

  4. Adhesion protein VSIG1 is required for the proper differentiation of glandular gastric epithelia.

    Directory of Open Access Journals (Sweden)

    Odgerel Oidovsambuu

    Full Text Available VSIG1, a cell adhesion protein of the immunoglobulin superfamily, is preferentially expressed in stomach, testis, and certain gastric, esophageal and ovarian cancers. Here, we describe the expression patterns of three alternatively spliced isoforms of mouse Vsig1 during pre- and postnatal development of stomach and potential function of Vsig1 in differentiation of gastric epithelia. We show that isoforms Vsig1A and Vsig1B, which differ in the 3'untranslated region, are expressed in the early stages of stomach development. Immunohistochemical analysis revealed that VSIG1 is restricted to the adherens junction of the glandular epithelium. The shorter transcript Vsig1C is restricted to the testis, encodes an N-terminal truncated protein and is presumably regulated by an internal promoter, which is located upstream of exon 1b. To determine whether the 5' flanking region of exon 1a specifically targets the expression of Vsig1 to stomach epithelia, we generated and analyzed transgenic mice. The 4.8-kb fragment located upstream of exon 1a was sufficient to direct the expression of the reporter gene to the glandular epithelia of transgenic stomach. To determine the role of VSIG1 during the development of stomach epithelia, an X-linked Vsig1 was inactivated in embryonic stem cells (ESCs. Although Vsig1(-/Y ESCs were only able to generate low coat color chimeric mice, no male chimeras transmitted the targeted allele to their progeny suggesting that the high contribution of Vsig1(-/Y cells leads to the lethality of chimeric embryos. Analysis of chimeric stomachs revealed the differentiation of VSIG1-null cells into squamous epithelia inside the glandular region. These results suggest that VSIG1 is required for the establishment of glandular versus squamous epithelia in the stomach.

  5. A computational approach to resolve cell level contributions to early glandular epithelial cancer progression

    OpenAIRE

    Park Sunwoo; Mostov Keith; Debnath Jayanta; Kim Sean HJ; Hunt C Anthony

    2009-01-01

    Abstract Background Three-dimensional (3D) embedded cell cultures provide an appropriate physiological environment to reconstruct features of early glandular epithelial cancer. Although these are orders of magnitude simpler than tissues, they too are complex systems that have proven challenging to understand. We used agent-based, discrete event simulation modeling methods to build working hypotheses of mechanisms of epithelial 3D culture phenotype and early cancer progression. Starting with a...

  6. Morphology and histochemistry of glandular trichomes of Orobanche alba Stephan ex Willd

    Directory of Open Access Journals (Sweden)

    Aneta Sulborska

    2014-04-01

    Full Text Available Orobanche alba Stephan ex Willd is an achlorophyllous root parasite rare in Poland. It prefers dry and sunny slopes, xerothermic grasslands and pastures, mountain pastures, light scrubs, and rock fissures and ledges. The hosts of O. alba include Thymus polytrichus A. ern. ex Borbás, Clinopodium vulgare L. and Origanum vulgare L. The tick and fleshy 10-70 cm high stem in this species bears an inflorescence composed of zygomorphic, white or yellow “spotted” flowers covered by purple glandular trichomes. Glandular trichomes of this type are also borne on other parts of the plant, i.e. on the stem, scaly leaves, sepals, filaments, and the style. The secondary metabolites secreted by the glandular trichomes are related to defense of plants against the attack of herbivores and pathogens or act as attractants to pollinators or for fruit dispersal. The micromorphology and histochemistry of the glandular trichomes in O. alba were examined using scanning electron and light microscopes. In order to determine the type of secondary metabolites produced by the trichomes, the flowing histochemical assays were used: Sudan III and neutral red for detection of lipophilic compounds, IKI for detection of starch, and FeCl3 for detection of phenolic compounds. The peltate glandular trichomes of O. alba were characterised by a varied length (0.15‑0.48 mm and different activity phases. The trichome was composed of one larger basal epidermal cell, 1-3 hyaline stalk cells with a striated cuticle, a neck cell with a smooth cuticle on the surface, and a globose head formed of 8-18 secretory cells arranged in a circle. Many stalk cells of the trichomes, particularly those located on the corolla, contained anthocyanins, which give the trichomes dark carmine colour. In turn, the colour of the heads was dependent on trichome age: the heads were brown in older trichomes and yellow in younger hairs. Secretion was produced by both young and older trichomes. It penetrated

  7. Characterization of fibrillar collagens and extracellular matrix of glandular benign prostatic hyperplasia nodules.

    Directory of Open Access Journals (Sweden)

    Tyler M Bauman

    Full Text Available Recent studies have associated lower urinary tract symptoms (LUTS in men with prostatic fibrosis, but a definitive link between collagen deposition and LUTS has yet to be demonstrated. The objective of this study was to evaluate ECM and collagen content within normal glandular prostate tissue and glandular BPH, and to evaluate the association of clinical parameters of LUTS with collagen content.Fibrillar collagen and ECM content was assessed in normal prostate (48 patients and glandular BPH nodules (24 patients using Masson's trichrome stain and Picrosirius red stain. Second harmonic generation (SHG imaging was used to evaluate collagen content. Additional BPH tissues (n = 47 were stained with Picrosirius red and the association between clinical parameters of BPH/LUTS and collagen content was assessed.ECM was similar in normal prostate and BPH (p = 0.44. Total collagen content between normal prostate and glandular BPH was similar (p = 0.27, but a significant increase in thicker collagen bundles was observed in BPH (p = 0.045. Using SHG imaging, collagen content in BPH (mean intensity = 62.52; SEM = 2.74 was significantly higher than in normal prostate (51.77±3.49; p = 0.02. Total collagen content was not associated with treatment with finasteride (p = 0.47 or α-blockers (p = 0.52, pre-TURP AUA symptom index (p = 0.90, prostate-specific antigen (p = 0.86, post-void residual (PVR; p = 0.32, prostate size (p = 0.21, or post-TURP PVR (p = 0.51. Collagen content was not associated with patient age in patients with BPH, however as men aged normal prostatic tissue had a decreased proportion of thick collagen bundles.The proportion of larger bundles of collagen, but not total collagen, is increased in BPH nodules, suggesting that these large fibers may play a role in BPH/LUTS. Total collagen content is independent of clinical parameters of BPH and LUTS. If fibrosis and overall ECM deposition are

  8. High-resolution spiral CT of the breast at very low dose: concept and feasibility considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A.; Beister, Marcel; Kolditz, Daniel; Vollmar, Sabrina V.; Weigel, Michaela C.C. [University Erlangen-Nuernberg, Institute of Medical Physics, Erlangen (Germany); Boone, John M. [University of California Davis Medical Center, Department of Radiology, Sacramento, CA (United States)

    2012-01-15

    Mammography, today's standard imaging approach, has deficits with respect to the superimposition of anatomical structures. Dedicated CT of the breast so far indicated that it can provide superior soft-tissue imaging, but that it still has significant limitations with respect to spatial resolution and dose. We have assessed novel dedicated breast CT technology. Based on simulations and measurements we developed novel technology which uses direct-conversion CdTe material and photon-counting electronics with 100 {mu}m detector element size for close to 100% dose efficiency. We assessed the potential for the imaging of microcalcifications of 100 to 200 {mu}m diameter and soft-tissue lesions of 1 to 5 mm diameter by simulations at dose levels between 1 and 6 mGy. Microcalcifications of 150 {mu}m and soft-tissue lesions of 2 mm diameter were found to be clearly detectable at an average glandular dose of 3 mGy. Separate displays are required for high-resolution microcalcification and for low-resolution soft-tissue analysis. Total CT data acquisition time will be below 10 s. Dedicated breast CT may eventually provide comprehensive diagnostic assessment of microcalcifications and soft-tissue structures at dose levels equivalent to or below those of two-view screening mammography. (orig.)

  9. Identifying three ecological chemotypes of Xanthium strumarium glandular trichomes using a combined NMR and LC-MS method.

    Directory of Open Access Journals (Sweden)

    Fangfang Chen

    Full Text Available Xanthanolides, as the sesquiterpene lactones, are reportedly the major components for the pharmacological properties of X. strumarium L. species. Phytochemical studies indicated that the glandular structures on the surface of plant tissues would form the primary sites for the accumulation of this class of the compounds. As the interface between plants and their natural enemies, glandular trichomes may vary with respect to which of their chemicals are sequestered against different herbivores in different ecologies. However, to date, no data are available on the chemical characterisation of X. strumarium glandular cells. In this study, the trichome secretions of the X. strumarium species originating from nineteen unique areas across eleven provinces in China, were analysed by HPLC, LC-ESI-MS and NMR. For the first time three distinct chemotypes of X. strumarium glandular trichomes were discovered along with the qualitative and quantitative evaluations of their presence of xanthanolides; these were designated glandular cell Types I, II, and III, respectively. The main xanthanolides in Type I cells were 8-epi-xanthatin and xanthumin while no xanthatin was detected. Xanthatin, 8-epi-xanthatin, and xanthumin dominated in Type II cells with comparable levels of each being present. For Type III cells, significantly higher concentrations of 8-epi-xanthatin or xanthinosin (relative to xanthatin were detected with xanthinosin only being observed in this type. Further research will focus on understanding the ecological and molecular mechanism causing these chemotype differences in X. strumarium glandular structures.

  10. Identifying three ecological chemotypes of Xanthium strumarium glandular trichomes using a combined NMR and LC-MS method.

    Science.gov (United States)

    Chen, Fangfang; Hao, Fuhua; Li, Changfu; Gou, Junbo; Lu, Dayan; Gong, Fujun; Tang, Huiru; Zhang, Yansheng

    2013-01-01

    Xanthanolides, as the sesquiterpene lactones, are reportedly the major components for the pharmacological properties of X. strumarium L. species. Phytochemical studies indicated that the glandular structures on the surface of plant tissues would form the primary sites for the accumulation of this class of the compounds. As the interface between plants and their natural enemies, glandular trichomes may vary with respect to which of their chemicals are sequestered against different herbivores in different ecologies. However, to date, no data are available on the chemical characterisation of X. strumarium glandular cells. In this study, the trichome secretions of the X. strumarium species originating from nineteen unique areas across eleven provinces in China, were analysed by HPLC, LC-ESI-MS and NMR. For the first time three distinct chemotypes of X. strumarium glandular trichomes were discovered along with the qualitative and quantitative evaluations of their presence of xanthanolides; these were designated glandular cell Types I, II, and III, respectively. The main xanthanolides in Type I cells were 8-epi-xanthatin and xanthumin while no xanthatin was detected. Xanthatin, 8-epi-xanthatin, and xanthumin dominated in Type II cells with comparable levels of each being present. For Type III cells, significantly higher concentrations of 8-epi-xanthatin or xanthinosin (relative to xanthatin) were detected with xanthinosin only being observed in this type. Further research will focus on understanding the ecological and molecular mechanism causing these chemotype differences in X. strumarium glandular structures. PMID:24098541

  11. Neutron resonance averaging

    International Nuclear Information System (INIS)

    The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

  12. The United States experience in patient dose and image quality

    International Nuclear Information System (INIS)

    In the United States the Nationwide Evaluation of X-ray Trends (NEXT), a cooperative federal-state survey programme, measures the average radiation air kerma associated with several specific diagnostic X-ray examinations. Chest radiography was surveyed in 1984 and 1986, the abdomen-L/S spine in 1987 and 1989, computed tomography in 1990, and dental radiography in 1993. Since 1984, patient exposure equivalent phantoms have been used for each annual survey. Three examinations, mammography (1985, 1988, 1992); fluoroscopy (1991), and dental radiography (1993) have incorporated image quality test objects. The surveys are comprehensive, collecting data such as screen and film type, whether a grid is used, selected X-ray tube potential, measured beam quality, the measurement of processing speed, and entrance air kerma. The trend in mammography, which has been observed for three separate surveys, shows an overall decrease in the average examination dose during this period of time, while image quality has improved. The main reason for the reduction in dose is the elimination of xerography relative to screen-film mammography. Within screen-film mammography an improvement has been observed in film processing, an improvement in beam quality, and an increase in mean glandular dose for screen-film systems. The fluoroscopy survey showed an average air kerma of 43 Gy.min-1. The image quality evaluation showed 87% of surveyed facilities able to resolve at least the 20 wire mesh (equivalent to 0.8 1p.mm-1); while 51% of facilities had a per cent contrast sensitivity greater than 4%. (Author)

  13. Averaging anisotropic cosmologies

    International Nuclear Information System (INIS)

    We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of anisotropic pressure-free models. Adopting the Buchert scheme, we recast the averaged scalar equations in Bianchi-type form and close the standard system by introducing a propagation formula for the average shear magnitude. We then investigate the evolution of anisotropic average vacuum models and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. The presence of nonzero average shear in our equations also allows us to examine the constraints that a phase of backreaction-driven accelerated expansion might put on the anisotropy of the averaged domain. We close by assessing the status of these and other attempts to define and calculate 'average' spacetime behaviour in general relativity

  14. Si-Accumulation In Artemisia annua Glandular Trichomes Increases Artemisinin Concentration, but Does Not Interfere In the Impairment of Toxoplasma gondii Growth

    Science.gov (United States)

    Rostkowska, Cristina; Mota, Caroline M.; Oliveira, Taísa C.; Santiago, Fernanda M.; Oliveira, Lilian A.; Korndörfer, Gaspar H.; Lana, Regina M. Q.; Rossi, Monica L.; Nogueira, Neusa L.; Simonnet, Xavier; Mineo, Tiago W. P.; Silva, Deise A.O.; Mineo, José R.

    2016-01-01

    Artemisia annua is used as a source of artemisinin, a potent therapeutic agent used for the treatment of infectious diseases, chiefly malaria. However, the low concentration (from 0.01 to 1.4% of dried leaf matter) of artemisinin in the plant obtained with the traditional cropping system makes it a relatively expensive drug, especially in developing countries. Considering that artemisinin and silicon (Si) are both stored in A. annua glandular trichomes, and that Si accumulation has never been investigated, this study aimed to look into Si effects on A. annua trichome artemisinin concentration, and whether leaf infusion from Si-treated A. annua plants is able to control Toxoplasma gondii growth. T. gondii is the etiologic agent of toxoplasmosis, a zoonotic parasitic disease whose traditional treatment shows significant side effects. The experimental design consisted of A. annua seedlings randomly planted in soil treated with different doses of calcium/magnesium silicate (0, 200, 400, 800, and 1600 kg ha-1). Analysis of foliar macronutrients showed significant increases of nitrogen content only at the highest dose of silicate. Foliar micronutrients, Si concentrations, and plant height were not affected by any of the silicate doses. However, the dose of 400 kg ha-1 of silicate increased the trichome size, which in turn raised artemisinin concentration in leaves and the infusion. In contrast, the 800 and 1600 kg ha-1 doses dramatically decreased artemisinin concentration. HeLa cell treatment with the infusion of A. annua grown in soil treated with 400 kg ha-1 of silicate decreased parasite proliferation in a dose-dependent manner when the treatment was carried out after or along with T. gondii infection. However, this effect was similar to A. annua grown in soil without silicate treatment. Thus, it can be concluded that, even though Si applied to the soil at 400 kg ha-1 has a positive effect on the A. annua glandular trichome size and the artemisinin concentration

  15. Dose and risk evaluation in digital mammography using computer modeling

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Samanda Cristine Arruda; Souza, Edmilson Monteiro de, E-mail: scorrea@nuclear.ufrj.b, E-mail: emonteiro@nuclear.ufrj.b [Centro Universitario Estadual da Zona Oeste (CCMAT/UEZO), Rio de Janeiro, RJ (Brazil); Silva, Humberto de Oliveira, E-mail: hbetorj@gmail.co [Universidade Federal do Rio de Janeiro IF/UFRJ, RJ (Brazil). Inst. de Fisica; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Magalhaes, Sarah Braga, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b, E-mail: smagalhaes@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2010-07-01

    Digital mammography has been introduced in several countries in the last years. The new technology requires new optimising methods considering for instance the increased possibility of changing the absorbed dose, mainly in modern mammographic systems that allow the operator to choose the beam quality by varying the tube voltage, and filter and target materials. In this work, the Monte Carlo code MCNPX is used in order to investigate how the average glandular dose vary with tube voltage (23-32 kV) and anode-filter combination (Mo-Mo,Mo-Rh and Rh-Rh) in digital mammographic examinations. Furthermore, the risk of breast cancer incidence attributable to mammography exams was estimated using the Biological Effects of Ionizing Radiations (BEIR) VII Committee Report. The results show that the risk of breast cancer incidence in women younger than 30 years of age tends to decrease significantly using Rh-Rh anode-filter combination and higher tube voltage. For women older than 50 years of age the variation of tube voltage, and anode-filter combination did not influence the risk values considerably. (author)

  16. Epithelial cell proliferation and glandular atrophy in lymphocytic gastritis: Effect of H pylori treatment

    Institute of Scientific and Technical Information of China (English)

    Johanna M. Makinen; Seppo Niemela; Tuomo Kerola; Juhani Lehtola; Tuomo J. Karttunen

    2003-01-01

    AIM: Lymphocytic gastritis is commonly ass ociated with Helicobacter pylori infection. The presence of glandular atrophy and foveolar hyperplasia in lymphocytic gastritis suggests abnormalities in cell proliferation and differentiation,forming a potential link with the suspected association with gastric cancer. Our aim was to compare epithelial cell proliferation and morphology in H pylori associated lymphocytic gastritis and H pylori gastritis without features of lymphocytic gastritis,and to evaluate the effect of H pylori treatment.METHODS: We studied 14 lymphocytic gastritis patients with H pylori infection. For controls, we selected 14 matched dyspeptic patients participating in another treatment trial whose H pylori infection had successfully been eradicated.Both groups were treated with a triple therapy and followed up with biopsies for 6-18 months (patients) or 3 months (controls). Blinded evaluation for histopathological features was carried out. To determine the cell proliferation index,the sections were labeled with Ki-67 antibody.RESULTS: Before treatment, lymphocytic gastritis was characterized by foveolar hyperplasia (P=0.001) and glandular atrophy in the body (P=0.008), and increased proliferation in both the body (P=0.001) and antrum (P=0.002). Proliferation correlated with foveolar hyperplasia and inflammation activity. After eradication therapy, the number of intraepithelial lymphocytes decreased in the body (P=0.004)and antrum (P=0.065), remaining higher than in controls (P<0.001). Simultaneously, the proliferation index decreased in the body from 0.38 to 0.15 (P=0.043), and in the antrum from 0.34 to 0.20 (P=0.069), the antral index still being higher in lymphocytic gastritis than in controls (P=0.010).Foveolar hyperplasia and glandular atrophy in the body improved (P=0.021), reaching the non-LG level.CONCLUSION: In lymphocytic gastritis, excessive epithelial cell proliferation is predominantly present in the body, where it associates with

  17. Investigation of breast dose in five screening mammography centres in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Tsapaki, V [Medical Physics Department, Konstantopoulio Hospital, Nea Ionia, 142 33, Athens (Greece); Tsalafoutas, I A [Medical Physics Department, Agios Savvas Hospital, 171 Alexandras Avenue, 115 22, Athens (Greece); Poga, V; Louizi, A; Kottou, S [Medical Physics Department, Medical School, Athens University, University of Athens, 75 Mikras Asias, 115 27, Athens (Greece); Koulentianos, E [Radiology Department, Konstantopoulio Hospital, Nea Ionia, 142 33, Athens (Greece)

    2008-09-01

    The objectives of this study were to investigate the techniques currently used for screening mammography in Greece, to estimate the mean glandular dose (MGD) for establishing a baseline radiation dose database, to analyse the effects of various factors on MGD, and to compare the results with others in the literature. Five mammographic facilities and 250 women having as a routine screening mammogram one craniocaudal (CC) and one mediolateral oblique (MLO) projection in each breast were included in the study. The parameters recorded were age, weight, compressed breast thickness (CBT), tube potential (kV), tube loading (mA s) and MLO projection angle. Large differences were observed among the different mammography facilities, mainly in terms of the tube potential setting and the MLO angle used. The average MGD per exposure was 1.4 {+-} 0.6 mGy while the respective averages separately for the CC and MLO projections were 1.2 {+-} 0.5 and 1.5 {+-} 0.7 mGy, respectively. The average MGD values recorded in this study were below the limit of 2 mGy established for the reference medium-sized breast of 4.5 cm CBT. However, the variety of techniques observed revealed the need for a nationwide survey concerning screening mammography in Greece.

  18. Report of the committee study on the dose and image quality in examination of breast cancer

    International Nuclear Information System (INIS)

    The dose and image quality were studied in 104 facilities conducting mammography and factors influencing on those were analyzed. The purpose of the study was to make the domestic system of the quality assurance/quality control (QA/QC) of mammography for examinee. Each facility irradiated the QC mamma phantom RMI-156 and fluoro-glass dosimeter GD403 provided by the present committee with X-ray generator for mammography with Mo/Mo focus/filter system at 28 kV with auto exposure control mode. The phantom, dosimeter and film were sent back to the committee. Films were analyzed by 4 experts and dose was evaluated by the average glandular dose (Dg), which was DgN(V, HVL, T, P) x R, where DgN: normalized Dg, V: tube voltage, HVL: Al half value layer, T: pressed thickness, P: fat content of the mammary gland and R: irradiation dose. Choice of appropriate imaging equipment and DPE conditions, and education concerning the mammography QA/QC were pointed out important for getting the high quality image. (K.H.)

  19. Administration of trimethoprim-sulphadimidine does not improve healing of glandular gastric ulceration in horses receiving omeprazole: a randomised, blinded, clinical study

    OpenAIRE

    Sykes, Ben W; Sykes, Katja M; Hallowell, Gayle D

    2014-01-01

    Background Interest in Equine Gastric Ulcer Syndrome (EGUS) has recently increased in part due to a growing awareness of the differences between squamous and glandular disease. The pathophysiology and epidemiology of squamous and glandular disease are different and recently it has been shown that the response of glandular gastric ulceration to monotherapy with omeprazole is poor. Given these differences it has been recommended that specific treatment guidelines be formulated for equine glandu...

  20. Morphological characterization of gland cells of the glandular sac area in the complex stomach of the Bactrian camel (Camelus bactrianus).

    Science.gov (United States)

    Eerdunchaolu; Takehana, K; Kobayashi, A; Baiyin; Cao, G F; Andrén, A; Iwasa, K; Abe, M

    1999-07-01

    The morphology of the gland cells in the glandular sac area of the Bactrian camel and the composition of secretory substances were examined by histochemical methods. It was found that the gland cells of the glandular sac area were of the same type and size as those of the cardiac glands. The composition of secretory substances from the glandular sac area was the same as that of secretory substances from the cardiac glands. Moreover, secretory substances from the gland cells of the glandular sac area contained a great deal of acid glycoconjugates, such as sialic acid, in addition to neutral saccharides (fucose, mannose, glucose, N-acetyl-D-glucosamin, galactose and N-acetyl-galactosamin). Furthermore, immunohistochemical examination showed that progastricsin was present in the gland cells of the glandular sac area and the cardiac gland. In this study, histological analysis suggested that the stomach of the Bactrian camel is a single cavity stomach, formed as a result of multiple differentiation and growth of cardiac glands through the process of evolution.

  1. Average-energy games

    OpenAIRE

    Bouyer, Patricia; Markey, Nicolas; Randour, Mickael; Larsen, Kim G.; Laursen, Simon

    2015-01-01

    Two-player quantitative zero-sum games provide a natural framework to synthesize controllers with performance guarantees for reactive systems within an uncontrollable environment. Classical settings include mean-payoff games, where the objective is to optimize the long-run average gain per action, and energy games, where the system has to avoid running out of energy. We study average-energy games, where the goal is to optimize the long-run average of the accumulated energy. We show that this ...

  2. INDUCTION OF GASTRIC INTRAEPITHELIAL NEOPLASIA OF GLANDULAR STOMACH OF MONGOLIAN GERBILS BY ELICOBACTER PYLORI

    Institute of Scientific and Technical Information of China (English)

    ZHOU Pin; GU Lian-kun; ZHOU Jing; WANG Ru-ming; ZHAO Zi-hou; DENG Da-jun

    2005-01-01

    Objective: To setup an animal model of gastric carcinogenesis by Helicobacter pylori (Hp) for basic, prevention and therapeutic research of Hp-related diseases. Methods: 22 young male Mongolian gerbils were administrated with suspension of Hp strain TN2 by intragastric gavage for 5 consecutive times (4×108 CFU/time, 1 time/4 days). 10 male gerbils were used as negative control. Two infected gerbils were killed at 10, 20, and 30 weeks, respectively, after inoculation to monitor the development of gastric lesions. Other animals were killed at 40 experimental weeks.Pathological changes of glandular stomach were examined histologically. Results: Gastric intraepithelial neoplasias (GIN) and low-grade dysplasias were observed only in the pyloric antrum of Hp-treated gerbils (3 and 2 ones,respectively), but not in control group (5/13 vs. 0/10, P<0.04). High incidence of chronic active gastritis and chronic atrophic gastritis were observed in Hp-treated animals (10/13, 76.9%). Low incidence of chronic atrophic gastritis was also detected in negative control gerbils (3/10, 30%; P<0.04). Conclusion: Hp inoculation could induce chronic inflammation and malignant lesions of the glandular stomach of Mongolian gerbils conveniently.

  3. A polynomial hyperelastic model for the mixture of fat and glandular tissue in female breast.

    Science.gov (United States)

    Calvo-Gallego, Jose L; Martínez-Reina, Javier; Domínguez, Jaime

    2015-09-01

    In the breast of adult women, glandular and fat tissues are intermingled and cannot be clearly distinguished. This work studies if this mixture can be treated as a homogenized tissue. A mechanical model is proposed for the mixture of tissues as a function of the fat content. Different distributions of individual tissues and geometries have been tried to verify the validity of the mixture model. A multiscale modelling approach was applied in a finite element model of a representative volume element (RVE) of tissue, formed by randomly assigning fat or glandular elements to the mesh. Both types of tissues have been assumed as isotropic, quasi-incompressible hyperelastic materials, modelled with a polynomial strain energy function, like the homogenized model. The RVE was subjected to several load cases from which the constants of the polynomial function of the homogenized tissue were fitted in the least squares sense. The results confirm that the fat volume ratio is a key factor in determining the properties of the homogenized tissue, but the spatial distribution of fat is not so important. Finally, a simplified model of a breast was developed to check the validity of the homogenized model in a geometry similar to the actual one. PMID:25950862

  4. Toad Glandular Secretions and Skin Extractions as Anti-Inflammatory and Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Ji Qi

    2014-01-01

    Full Text Available Toad glandular secretions and skin extractions contain many natural agents which may provide a unique resource for novel drug development. The dried secretion from the auricular and skin glands of Chinese toad (Bufo bufo gargarizans is named Chansu, which has been used in Traditional Chinese Medicine (TCM for treating infection and inflammation for hundreds of years. The sterilized hot water extraction of dried toad skin is named Huachansu (Cinobufacini which was developed for treating hepatitis B virus (HBV and several types of cancers. However, the mechanisms of action of Chansu, Huachansu, and their constituents within are not well reported. Existing studies have suggested that their anti-inflammation and anticancer potential were via targeting Nuclear Factor (NF-κB and its signalling pathways which are crucial hallmarks of inflammation and cancer in various experimental models. Here, we review some current studies of Chansu, Huachansu, and their compounds in terms of their use as both anti-inflammatory and anticancer agents. We also explored the potential use of toad glandular secretions and skin extractions as alternate resources for treating human cancers in combinational therapies.

  5. Immunohistochemical evidence: testicular and scented glandular androgen synthesis in muskrats (Ondatra zibethicus during the breeding season

    Directory of Open Access Journals (Sweden)

    Q. Li

    2011-10-01

    Full Text Available In order to elucidate the relationship between androgens and the function of the muskrat (Ondatra zibethicus scented glands during the breeding season, we investigated immunolocalization of steroidogenic enzymes P450scc, 3βHSD and P450c17 in the muskrat testes and scented glands. Nine adult muskrats were obtained in March (n=3, May (n=3 and July (n=3 2010. Steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal P450scc, human placental 3βHSD and porcine testicular P450c17. Histologically, all types of spermatogenic cells including mature–phase spermatozoa in seminiferous tubules were observed in all testes. Glandular cells, interstitial cells, epithelial cells and excretory tubules were identified in scented glands during the breeding season. P450scc, 3βHSD and P450c17 were only identified in Leydig cells during the breeding season; P450scc and P450c17 were observed in glandular cells of scented glands, however, 3βHSD was not found in scented glands during the breeding season. These novel findings provide the first evidence showing that scented glands of the muskrats are capable of locally synthesizing androgens and androgens acting via an endocrine, autocrine or paracrine manner may play an important role in scented gland function during the breeding season.

  6. Optimization of dose radiation and image quality on computed tomography of thorax in adult women

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, G. R.; Casian C, G. [Hospital Juarez de Mexico, Av. IPN No. 5160, 07760 Mexico D. F. (Mexico); Gaona, E.; Franco E, J. G.; Molina F, N., E-mail: gaen1310@correo.xoc.uam.mx [Universidad Autonoma Metropolitana, Unidad Xochimilco, Calz. del Hueso 1100, 04960 Mexico D. F. (Mexico)

    2015-10-15

    Full text: The objective of the study is the optimization of the dose (Dlp) and image quality in the exploration of adult women in studies of thorax with computed tomography (CT). The CT is a technique of exploration with high radiation doses to patients with an increase of the risk factors of developing cancer in the future, but X-rays are a very important medical diagnostic tool. We performed a retrospective survey of 50 female patients who had thorax tomography using the automatic protocol established by the manufacturer, a database of dose (Dlp), measures of patient A P and radiological parameters such as kV and m A was obtained. Subsequently, we carry out the prospective study with 30 patients with prescription of thorax tomography, scans were conducted with CT with reduced doses using manual techniques protocol of exploration while maintaining diagnostic image quality. The results show that the prospective study patients received doses lower than 30% on average. In general the dose patients were within the confidence interval of 95% of the levels of diagnostic reference (DRL) adopted by the European Community for CT and the most common value is 400 Dlp for thorax. Comparative image quality study was conducted using the protocol of the manufacturer and the manual protocol and image quality was diagnostic after dose reduction up to 30%. The reduction of radiation dose in female patients in studies of thorax CT helps to reduce risk factors of developing cancer later in life. A thorax tomography study includes the fibro-glandular tissue of the breast which is very sensitive to stochastic effects of radiation. (Author)

  7. Averaged extreme regression quantile

    OpenAIRE

    Jureckova, Jana

    2015-01-01

    Various events in the nature, economics and in other areas force us to combine the study of extremes with regression and other methods. A useful tool for reducing the role of nuisance regression, while we are interested in the shape or tails of the basic distribution, is provided by the averaged regression quantile and namely by the average extreme regression quantile. Both are weighted means of regression quantile components, with weights depending on the regressors. Our primary interest is ...

  8. On the Averaging Principle

    OpenAIRE

    Fibich, Gadi; Gavious, Arieh; Solan, Eilon

    2012-01-01

    Typically, models with a heterogeneous property are considerably harder to analyze than the corresponding homogeneous models, in which the heterogeneous property is replaced with its average value. In this study we show that any outcome of a heterogeneous model that satisfies the two properties of differentiability and interchangibility is O(\\epsilon^2) equivalent to the outcome of the corresponding homogeneous model, where \\epsilon is the level of heterogeneity. We then use this averaging pr...

  9. Average Angular Velocity

    OpenAIRE

    Van Essen, H.

    2004-01-01

    This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to th...

  10. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    1999-01-01

    In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion...

  11. General considerations of the choice of dose limits, averaging areas and weighting factors for the skin in the light of revised skin cancer risk figures and experimental data on non-stochastic effects

    International Nuclear Information System (INIS)

    Recent biological data from man and pig on the non-stochastic effects following exposure with a range of β-emitters are combined with recent epidemiological analyses of skin cancer risks in man to form a basis for suggested improved protection criteria following whole- or partial-body skin exposures. Specific consideration is given to the choice of an organ weighting factor for evaluation of effective dose-equivalent. Since stochastic and non-stochastic end-points involve different cell types at different depths in the skin, the design of an ideal physical dosemeter may depend on the proportion of the body skin exposed and the radiation penetrating power. Possible choices of design parameters for skin dosemeters are discussed. Limitation of skin exposure from small radioactive sources ('hot particles') is addressed using animal data. (author)

  12. Promoters of AaGL2 and AaMIXTA-Like1 genes of Artemisia annua direct reporter gene expression in glandular and non-glandular trichomes.

    Science.gov (United States)

    Jindal, Sunita; Longchar, Bendangchuchang; Singh, Alka; Gupta, Vikrant

    2015-01-01

    Herein, we report cloning and analysis of promoters of GLABRA2 (AaGL2) homolog and a MIXTA-Like (AaMIXTA-Like1) gene from Artemisia annua. The upstream regulatory regions of AaGL2 and AaMIXTA-Like1 showed the presence of several crucial cis-acting elements. Arabidopsis and A. annua seedlings were transiently transfected with the promoter-GUS constructs using a robust agro-infiltration method. Both AaGL2 and AaMIXTA-Like1 promoters showed GUS expression preferentially in Arabidopsis single-celled trichomes and glandular as well as T-shaped trichomes of A. annua. Transgenic Arabidopsis harboring constructs in which AaGL2 or AaMIXTA-Like1 promoters would control GFP expression, showed fluorescence emanating specifically from trichome cells. Our study provides a fast and efficient method to study trichome-specific expression, and 2 promoters that have potential for targeted metabolic engineering in plants.

  13. Promoters of AaGL2 and AaMIXTA-Like1 genes of Artemisia annua direct reporter gene expression in glandular and non-glandular trichomes.

    Science.gov (United States)

    Jindal, Sunita; Longchar, Bendangchuchang; Singh, Alka; Gupta, Vikrant

    2015-01-01

    Herein, we report cloning and analysis of promoters of GLABRA2 (AaGL2) homolog and a MIXTA-Like (AaMIXTA-Like1) gene from Artemisia annua. The upstream regulatory regions of AaGL2 and AaMIXTA-Like1 showed the presence of several crucial cis-acting elements. Arabidopsis and A. annua seedlings were transiently transfected with the promoter-GUS constructs using a robust agro-infiltration method. Both AaGL2 and AaMIXTA-Like1 promoters showed GUS expression preferentially in Arabidopsis single-celled trichomes and glandular as well as T-shaped trichomes of A. annua. Transgenic Arabidopsis harboring constructs in which AaGL2 or AaMIXTA-Like1 promoters would control GFP expression, showed fluorescence emanating specifically from trichome cells. Our study provides a fast and efficient method to study trichome-specific expression, and 2 promoters that have potential for targeted metabolic engineering in plants. PMID:26340695

  14. Impacts of radiation dose on survival in 72 patients with average-risk medulloblastoma%72例标危型髓母细胞瘤放疗剂量对生存的影响

    Institute of Scientific and Technical Information of China (English)

    甄子俊; 路素英; 夏云飞; 吴少雄; 王翦; 朱佳; 王娟; 杨群英; 孙晓非

    2015-01-01

    目的:回顾分析标危型髓母细胞瘤采用全脑全脊髓放疗剂量≤24 Gy和>24 Gy对预后的影响。方法标危型髓母细胞瘤定义为年龄>3岁、未发生转移、肿瘤全切或近全切(残留≤1�5 cm3)。2003—2013年共入组72例初治儿童、青少年标危型髓母细胞瘤患者。患者术后接受全脑全脊髓+局部瘤床放疗和8个疗程辅助化疗,化疗方案为顺铂、司莫司汀或卡莫司汀联合长春新碱。按放疗剂量≤24 Gy和>24 Gy分为A、B组(20、52例),比较两组患者复发率和生存率。 Kaplan⁃Meier法计算复发率和生存率并Logrank法检验组间差异。结果 A组接受全脑全脊髓放疗19.2~24�0 Gy,B组接受全脑全脊髓放疗24.1~30�6 Gy。放疗后66例(92%)患者完成全部辅助化疗。共11例患者复发。随访满3年患者48例,其中复发11例,死亡7例。全组3年EFS率为83%,3年OS率为86%。 A组和B组患者3年EFS率分别为84%和83%( P=0�609),3年OS率分别为85%和87%( P=0�963)。结论标危型髓母细胞瘤经规范综合治疗效果较好,其中全脑全脊髓放疗剂量减少至19.2~24�0 Gy未影响疗效。%Objective To retrospectively analyze the impacts of a craniospinal radiation dose ≤24 Gy or>24 Gy on the prognosis of patients with average⁃risk medulloblastoma. Methods Average⁃risk medulloblastoma was defined as non⁃metastatic cancer in children more than 3 years old with complete or near⁃complete ( residual tumor ≤1�5 cm3 ) resection of tumor. A total of 72 children and adolescents with newly diagnosed average⁃risk medulloblastoma were enrolled as subjects from 2003 to 2013. After radical resection of the tumor, all patients received craniospinal plus local tumor bed radiotherapy and 8 cycles of adjuvant chemotherapy using cisplatin⁃, semustine⁃, or plus vincristine⁃based regimens. Patients exposed to a radiation dose ≤24 Gy

  15. Averaging anisotropic cosmologies

    CERN Document Server

    Barrow, J D; Barrow, John D.; Tsagas, Christos G.

    2006-01-01

    We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of pressure-free Bianchi-type models. Adopting the Buchert averaging scheme, we identify the kinematic backreaction effects by focussing on spacetimes with zero or isotropic spatial curvature. This allows us to close the system of the standard scalar formulae with a propagation equation for the shear magnitude. We find no change in the already known conditions for accelerated expansion. The backreaction terms are expressed as algebraic relations between the mean-square fluctuations of the models' irreducible kinematical variables. Based on these we investigate the early evolution of averaged vacuum Bianchi type $I$ universes and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. We also discuss the possibility of accelerated expansion due to ...

  16. Average Angular Velocity

    CERN Document Server

    Essén, H

    2003-01-01

    This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to three parts: center of mass, rotational, plus the remaining internal energy relative to an optimally translating and rotating frame.

  17. On sparsity averaging

    CERN Document Server

    Carrillo, Rafael E; Wiaux, Yves

    2013-01-01

    Recent developments in Carrillo et al. (2012) and Carrillo et al. (2013) introduced a novel regularization method for compressive imaging in the context of compressed sensing with coherent redundant dictionaries. The approach relies on the observation that natural images exhibit strong average sparsity over multiple coherent frames. The associated reconstruction algorithm, based on an analysis prior and a reweighted $\\ell_1$ scheme, is dubbed Sparsity Averaging Reweighted Analysis (SARA). We review these advances and extend associated simulations establishing the superiority of SARA to regularization methods based on sparsity in a single frame, for a generic spread spectrum acquisition and for a Fourier acquisition of particular interest in radio astronomy.

  18. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    2001-01-01

    In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

  19. Radiation dose differences between digital mammography and digital breast tomosynthesis are dependent on breast thickness

    Science.gov (United States)

    Alakhras, Maram M.; Mello-Thoms, Claudia; Bourne, Roger; Rickard, Mary; Diffey, Jennifer; Brennan, Patrick C.

    2016-03-01

    Purpose To evaluate the radiation dose derived from digital mammography (DM) and digital breast tomosynthesis (DBT) at different tube current-exposure time product (mAs) and at 6 phantom thicknesses from 10 to 60 mm. Materials and Methods A total of 240 DM and DBT cranio-caudal (CC) phantom images were acquired at each thickness and at four exposure levels (the baseline mAs, 50%, 25% and 12.5% the baseline mAs). The incident Air Kerma (K) at the surface of the phantoms was measured using a solid state dosimeter. Mean Glandular Doses (MGD) were calculated for both modalities (DM and DBT). Results DBT dose was greater than that of DM for all mAs at each phantom thickness. For a breast thickness of 50 mm (close to average sized breast), the dose for DBT (2.32 mGy) was 13% higher than that for DM (2.05 mGy). The results also show that the difference in MGD between DM and DBT was less for the thicker compared with the thinner phantom, this difference being approximately a factor of 2.58 at 10 mm compared with a factor of 1.08 at 60 mm. While the MGD increased with increasing phantom thickness for both modalities, the dose increase with DBT was less than for DM, with the difference between 10 and 60 mm being a factor of 7 for DM and 3 for DBT. Conclusion The radiation dose from DBT was higher than that of DM and the difference in dose between DM and DBT decreases as phantom thickness increases.

  20. Auditing Mammographic Dose and Image Quality in the UK Breast Screening Programme

    Energy Technology Data Exchange (ETDEWEB)

    Young, K.C.; Ramsdale, M.L.; Rust, A

    1998-07-01

    A national audit of image quality and dose has been conducted across 267 mammography X ray sets in the UK Breast Screening Programme, repeating a previous survey in 1991. The main parameters were film density, film contrast, mean glandular dose to the standard breast (MGD) and image quality (IQ) measured with a TOR(MAM) test object. Film density has increased from a mean of 1.33 in 1991 to a mean of 1.61 in 1996 as a result of national guidelines. Over the same period the average MGD has increased from 1.28 to 1.36 mGy. Average film gradient ranged from 2.2 to 3.9 with a mean of 3.2. IQ ranged from 48 to 86 with a mean of 69. Causes of reduced IQ were low film densities, medium screens and older designs of mammography X ray set. Although film density and MGD were generally satisfactory, there appears to be room for further optimisation of film contrast and IQ. (author)

  1. Auditing Mammographic Dose and Image Quality in the UK Breast Screening Programme

    International Nuclear Information System (INIS)

    A national audit of image quality and dose has been conducted across 267 mammography X ray sets in the UK Breast Screening Programme, repeating a previous survey in 1991. The main parameters were film density, film contrast, mean glandular dose to the standard breast (MGD) and image quality (IQ) measured with a TOR(MAM) test object. Film density has increased from a mean of 1.33 in 1991 to a mean of 1.61 in 1996 as a result of national guidelines. Over the same period the average MGD has increased from 1.28 to 1.36 mGy. Average film gradient ranged from 2.2 to 3.9 with a mean of 3.2. IQ ranged from 48 to 86 with a mean of 69. Causes of reduced IQ were low film densities, medium screens and older designs of mammography X ray set. Although film density and MGD were generally satisfactory, there appears to be room for further optimisation of film contrast and IQ. (author)

  2. A case of glandular odontogenic cyst in the mandible treated with the dredging method.

    Science.gov (United States)

    Motooka, Naomi; Ohba, Seigo; Uehara, Masataka; Fujita, Syuichi; Asahina, Izumi

    2015-01-01

    Glandular odontogenic cyst (GOC) is a rare odontogenic cyst derived from the odontogenic epithelium. GOC shows unpredictable and potentially aggressive behavior. Although enucleation and curettage are applied in most cases, the recurrence rate remains relatively high. Because a standard care procedure for GOC has not been established, we propose a new treatment procedure for GOC. In this case report, we describe a 62-year-old Japanese woman who suffered from GOC arising at the anterior region of her mandible and who was treated using the dredging method. She underwent enucleation and curettage twice using the dredging method with preservation of the teeth, which were involved with the lesion, but the lesion recurred 2 years later. In addition to enucleation and curettage, apicoectomy of the teeth was performed with a third dredging method procedure, and prognosis has been good with no recurrence for 18 months since the last treatment. PMID:24374982

  3. Investigation of glandular trichome proteins in Artemisia annua L. using comparative proteomics.

    Directory of Open Access Journals (Sweden)

    Ting Wu

    Full Text Available Glandular secreting trichomes (GSTs are called biofactories because they are active in synthesizing, storing and secreting various types of plant secondary metabolites. As the most effective drug against malaria, artemisinin, a sesquiterpene lactone is derived from GSTs of Artemisia annua. However, low artemisinin content (0.001%~1.54% of dry weight has hindered its wide application. We investigate the GST-expressed proteins in Artemisia annua using a comparative proteomics approach, aiming for a better understanding of the trichome proteome and arteminisin metabolism. 2D-electrophoresis was employed to compare the protein profiles of GSTs and leaves. More than 700 spots were resolved for GSTs, of which ∼93 non-redundant proteins were confidently identified by searching NCBI and Artemisia EST databases. Over 70% of these proteins were highly expressed in GTSs. Functional classification of these GSTs enriched proteins revealed that many of them participate in major plant metabolic processes such as electron transport, transcription and translation.

  4. Atypical glandular cells in conventional cervical smears: Incidence and follow-up

    Directory of Open Access Journals (Sweden)

    Knolle Ulrich

    2004-07-01

    Full Text Available Abstract Background Atypical glandular cells on cervical smears are often associated with clinically significant uterine lesions. The frequency and accuracy of AGC-NOS (i.e. atypical glandular cells, not otherwise specified diagnoses, regardless of the gland cell type or the degree of suspicion, and their outcome were investigated. Methods From January 1, 1990 to December 31, 1999 a total of 261 patients had an AGC-NOS diagnosis made by conventional cervical Papanicolaou smear interpretation representing 0.05% of all Pap-smears analyzed at the national level. 191 (73.2% patients had a subsequent histological examination, 8 samples were not representative by origin and were excluded. Results Out of 183 AGC-NOS diagnosed, 56.3% (103/183 were associated with tissue-proven precancerous and/or cancerous lesions, 44% being of endocervical and 56% of endometrial origin. 75% of all AGC-patients were asymptomatic. 66.7% (6/9 of the patients with subsequent invasive endocervical adenocarcinoma (AC and 56% (28/50 of those patients with invasive endometrial AC were without clinical symptoms. 3 patients out of 9 with an invasive endocervical AC were 35 years of age or less. 10.1% and 12.3% of all 'new' tissue-proven invasive endocervical or endometrial AC respectively recorded by the national Morphologic Tumour Registry (MTR were first identified by a cytological AGC-NOS diagnosis. Conclusion Our findings emphasize the importance of the cytological AGC-category even in the absence of a precise origin or cell type specification. 56% of the AGC-diagnoses being associated with significant cancerous or precancerous conditions, a complete and careful evaluation is required.

  5. Clinical implications and histological correlation of atypical glandular cells found in cervicovaginal smears

    Directory of Open Access Journals (Sweden)

    Beliza Loos

    2014-08-01

    Full Text Available Introduction: Atypical glandular cells (AGC are carriers of insufficient nuclear abnormalities for the diagnosis of adenocarcinoma, but exceed the criteria for classification as reactive glandular cells. This is an uncommon diagnosis, which may be associated with neoplastic lesions. Objective: To evaluate the clinical significance of primary cytological diagnosis of AGC through correlation with results of subsequent cyto-histologic examination. Materials and methods: 10 years retrospective study based on cervical cytologic results indicating AGC, classified as "possibly non-neoplastic" or "cannot exclude high-grade intraepithelial lesion". It was performed cyto-histopathological correlation in cases that were submitted to subsequent histopathological examination up to two years after cervical cytology analysis. Results: AGC were reported in 380 (0.06% exams, providing 160 cases with subsequent biopsy. 85 (53.1% of these, presented benign changes and 75 (46.9% neoplastic lesions. From 114 "possibly non-neoplastic" cytological results, 71 (62.3% had benign histological changes, and 43 (37.7% neoplastic lesions, corresponding to a negative predictive value (NPV of 62.3%. In contrast, among the 46 AGC "cannot exclude high-grade intraepithelial lesion" results, 14 (30.4% presented benign changes and 32 (69.6% neoplastic lesions (positive predictive value [PPV] = 69.6%. Discussion: The high rate of cancer associated with the diagnosis of AGC reassures the importance of recognizing these atypical cells in pap smears. The classification of "possibly non-neoplastic" and "cannot exclude high-grade intraepithelial lesion" may suggest the origin of cytological changes. Conclusion: Our results reinforce the importance of adequate follow-up of patients with AGC diagnosis on cervical cytology.

  6. Glandular Proteome Identifies Antiprotease Cystatin C as a Critical Modulator of Airway Hydration and Clearance.

    Science.gov (United States)

    Evans, T Idil Apak; Joo, Nam Soo; Keiser, Nicholas W; Yan, Ziying; Tyler, Scott R; Xie, Weiliang; Zhang, Yulong; Hsiao, Jordy J; Cho, Hyung-Ju; Wright, Michael E; Wine, Jeffrey J; Engelhardt, John F

    2016-04-01

    Defects in the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel lead to viscous secretions from submucosal glands that cannot be properly hydrated and cleared by beating cilia in cystic fibrosis (CF) airways. The mechanisms by which CFTR, and the predominant epithelial sodium channel (ENaC), control the hydration and clearance of glandular secretions remain unclear. We used a proteomics approach to characterize the proteins contained in CF and non-CF submucosal gland fluid droplets and found that differentially regulated proteases (cathepsin S and H) and their antiprotease (cystatin C) influenced the equilibration of fluid on the airway surface and tracheal mucociliary clearance (MCC). Contrary to prevailing models of airway hydration and clearance, cystatin C, or raising the airway surface liquid (ASL) pH, inhibited cathepsin-dependent ENaC-mediated fluid absorption and raised the height of ASL, and yet decreased MCC velocity. Importantly, coupling of both CFTR and ENaC activities were required for effective MCC and for effective ASL height equilibration after volume challenge. Cystatin C-inhibitable cathepsins controlled initial phases of ENaC-mediated fluid absorption, whereas CFTR activity was required to prevent ASL dehydration. Interestingly, CF airway epithelia absorbed fluid more slowly owing to reduced cysteine protease activity in the ASL but became abnormally dehydrated with time. Our findings demonstrate that, after volume challenge, pH-dependent protease-mediated coupling of CFTR and ENaC activities are required for rapid fluid equilibration at the airway surface and for effective MCC. These findings provide new insights into how glandular fluid secretions may be equilibrated at the airway surface and how this process may be impaired in CF. PMID:26334941

  7. PTEN Phosphatase-Independent Maintenance of Glandular Morphology in a Predictive Colorectal Cancer Model System

    Directory of Open Access Journals (Sweden)

    Ishaan C. Jagan

    2013-11-01

    Full Text Available Organotypic models may provide mechanistic insight into colorectal cancer (CRC morphology. Three-dimensional (3D colorectal gland formation is regulated by phosphatase and tensin homologue deleted on chromosome 10 (PTEN coupling of cell division cycle 42 (cdc42 to atypical protein kinase C (aPKC. This study investigated PTEN phosphatase-dependent and phosphatase-independent morphogenic functions in 3D models and assessed translational relevance in human studies. Isogenic PTEN-expressing or PTEN-deficient 3D colorectal cultures were used. In translational studies, apical aPKC activity readout was assessed against apical membrane (AM orientation and gland morphology in 3D models and human CRC. We found that catalytically active or inactive PTEN constructs containing an intact C2 domain enhanced cdc42 activity, whereas mutants of the C2 domain calcium binding region 3 membrane-binding loop (M-CBR3 were ineffective. The isolated PTEN C2 domain (C2 accumulated in membrane fractions, but C2 M-CBR3 remained in cytosol. Transfection of C2 but not C2 M-CBR3 rescued defective AM orientation and 3D morphogenesis of PTEN-deficient Caco-2 cultures. The signal intensity of apical phospho-aPKC correlated with that of Na+/H+ exchanger regulatory factor-1 (NHERF-1 in the 3D model. Apical NHERF-1 intensity thus provided readout of apical aPKC activity and associated with glandular morphology in the model system and human colon. Low apical NHERF-1 intensity in CRC associated with disruption of glandular architecture, high cancer grade, and metastatic dissemination. We conclude that the membrane-binding function of the catalytically inert PTEN C2 domain influences cdc42/aPKC-dependent AM dynamics and gland formation in a highly relevant 3D CRC morphogenesis model system.

  8. The averaging principle

    OpenAIRE

    Fibich, Gadi; Gavious, Arieh; Solan, Eilon

    2012-01-01

    Typically, models with a heterogeneous property are considerably harder to analyze than the corresponding homogeneous models, in which the heterogeneous property is replaced with its average value. In this study we show that any outcome of a heterogeneous model that satisfies the two properties of \\emph{differentiability} and \\emph{interchangibility}, is $O(\\epsilon^2)$ equivalent to the outcome of the corresponding homogeneous model, where $\\epsilon$ is the level of heterogeneity. We then us...

  9. Glandular trichome density and essential oil composition in leaves and inflorescences of Lippia origanoides Kunth (Verbenaceae in the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Luiz R.S. Tozin

    2015-06-01

    Full Text Available The essential oils from leaves and inflorescences of Lippia origanoides Kunth present aromatic and medicinal potential and have been used to treat several diseases, including melanoma. In Brazil, L. origanoides is commonly found in campo cerrado and cerrado stricto sensu, physiognomies featured mainly by the differential light conditions to which short and medium-sized plants are subjected. Our aim was to investigate the glandular trichome density and the yield and chemical composition of the essential oils in leaves and inflorescences of L. origanoides from campo cerrado and cerrado stricto sensu. For glandular density analysis, leaves and inflorescences were processed according to conventional techniques for scanning electron microscopy. The essential oils of leaves and inflorescences were obtained by hydrodistillation and identified with gas chromatography. Bracts and sepals showed the highest glandular density, followed by petals and leaves. The glandular density in the abaxial leaf surface was higher in individuals from the campo cerrado. In both populations the essential oil yield was higher in inflorescences than in leaves. The chemical composition of the essential oils varied among individuals from different areas and inside a same population. Our results demonstrated the chemical plasticity of L. origanoides suggesting the importance of monitoring its popular use.

  10. Opposing Roles of Foliar and Glandular Trichome Volatile Components in Cultivated Nightshade Interaction with a Specialist Herbivore

    Science.gov (United States)

    Murungi, Lucy Kananu; Kirwa, Hillary; Salifu, Daisy; Torto, Baldwyn

    2016-01-01

    Plant chemistry is an important contributor to the interaction with herbivores. Here, we report on a previously unknown role for foliar and glandular trichome volatiles in their interaction with the specialist herbivore of solanaceous plants, the tomato red spider mite Tetranychus evansi. We used various bioassays and chemical analyses including coupled gas chromatography-mass spectrometry (GC/MS) and liquid chromatography coupled to quadrupole time of flight mass spectrometry (LC-QToF-MS) to investigate this interaction between cultivated African nightshades and T. evansi. We show that, whereas morphologically different cultivated African nightshade species released similar foliar volatile organic compounds (VOCs) that attracted T. evansi, VOCs released from exudates of ruptured glandular trichomes of one nightshade species influenced local defense on the leaf surface. VOCs from ruptured glandular trichomes comprising mainly saturated and unsaturated fatty acids deterred T. evansi oviposition. Of the fatty acids, the unsaturated fatty acids accounted for >40% of the oviposition deterrent activity. Our findings point to a defense strategy in a plant, based on opposing roles for volatiles released by foliar and glandular trichomes in response to attack by a specialist herbivore. PMID:27556560

  11. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  12. Cervical squamous and glandular intraepithelial neoplasia: identification and current management approaches Neoplasia intraepitelial cervical escamosa y glandular: identificación y estrategias de manejo

    Directory of Open Access Journals (Sweden)

    V Cecil Wright

    2003-01-01

    realiza mediante la biopsia de cono, y el espécimen debe tener márgenes negativos para enfermedad. La histerectomía es un tratamiento probable, a menos que la fertilidad esté siendo buscada. La escisión, particularmente por electrocirugía (loop, puede interferir con la interpretación histológica en algunos casos o de ambos, particularmente en enfermedades escamosas y adenocarcinoma in situ. En este artículo se describe ampliamente el manejo de la neoplasia intraepitelial escamosa y glandular.

  13. A detailed breast model and its application for Chinese female breast dose estimation in mammography

    International Nuclear Information System (INIS)

    The IAEA protocol for breast dosimetry is based on the calculations of Dance which used very simple models of the breast based on the western female data. In order to estimate the dose more precisely in the mammographic examination for the Chinese female, a 3D detailed breast model was constructed. This model contains the detailed structures in the breast, including skin, subcutaneous fat, Cooper's ligaments, and fibro-glandular region containing intra-glandular fat, gland, ductal system, and terminal ductal lobular units. And the size of this breast model was adjusted to represent the characteristic of Chinese female. The glandular tissue conversion coefficients were calculated using this detailed breast model with Monte Carlo code, Geant4. The comparison between the data obtained in this study and the data from Dance was carried out. The discrepancy may come from both the structure and size of the breast models

  14. Identification, functional characterization and developmental regulation of sesquiterpene synthases from sunflower capitate glandular trichomes

    Directory of Open Access Journals (Sweden)

    Ro Dae-Kyun

    2009-07-01

    Full Text Available Abstract Background Sesquiterpene lactones are characteristic metabolites of Asteraceae (or Compositae which often display potent bioactivities and are sequestered in specialized organs such as laticifers, resin ducts, and trichomes. For characterization of sunflower sesquiterpene synthases we employed a simple method to isolate pure trichomes from anther appendages which facilitated the identification of these genes and investigation of their enzymatic functions and expression patterns during trichome development. Results Glandular trichomes of sunflower (Helianthus annuus L. were isolated, and their RNA was extracted to investigate the initial steps of sesquiterpene lactone biosynthesis. Reverse transcription-PCR experiments led to the identification of three sesquiterpene synthases. By combination of in vitro and in vivo characterization of sesquiterpene synthase gene products in Escherichia coli and Saccharomyces cerevisiae, respectively, two enzymes were identified as germacrene A synthases, the key enzymes of sesquiterpene lactone biosynthesis. Due to the very low in vitro activity, the third enzyme was expressed in vivo in yeast as a thioredoxin-fusion protein for functional characterization. In in vivo assays, it was identified as a multiproduct enzyme with the volatile sesquiterpene hydrocarbon δ-cadinene as one of the two main products with α-muuorlene, β-caryophyllene, α-humulene and α-copaene as minor products. The second main compound remained unidentified. For expression studies, glandular trichomes from the anther appendages of sunflower florets were isolated in particular developmental stages from the pre- to the post-secretory phase. All three sesquiterpene synthases were solely upregulated during the biosynthetically active stages of the trichomes. Expression in different aerial plant parts coincided with occurrence and maturity of trichomes. Young roots with root hairs showed expression of the sesquiterpene synthase genes

  15. Survey of mammography practice in Croatia: equipment performance, image quality and dose.

    Science.gov (United States)

    Faj, Dario; Posedel, Dario; Stimac, Damir; Ivezic, Zdravko; Kasabasic, Mladen; Ivkovic, Ana; Kubelka, Dragan; Ilakovac, Vesna; Brnic, Zoran; Bjelac, Olivera Ciraj

    2008-01-01

    A national audit of mammography equipment performance, image quality and dose has been conducted in Croatia. Film-processing parameters, optical density (OD), average glandular dose (AGD) to the standard breast, viewing conditions and image quality were examined using TOR(MAM) test object. Average film gradient ranged from 2.6 to 3.7, with a mean of 3.1. Tube voltage used for imaging of the standard 45 mm polymethylmethacrylate phantom ranged from 24 to 34 kV, and OD ranged from 0.75 to 1.94 with a mean of 1.26. AGD to the standard breast ranged from 0.4 to 2.3 mGy with a mean of 1.1 mGy. Besides clinical conditions, the authors have imaged the standard phantom in the referent conditions with 28 kV and OD as close as possible to 1.5. Then, AGD ranged from 0.5 to 2.6 mGy with a mean of 1.3 mGy. Image viewing conditions were generally unsatisfying with ambient light up to 500 lx and most of the viewing boxes with luminance between 1000 and 2000 cd per m(2). TOR(MAM) scoring of images taken in clinical and referent conditions was done by local radiologists in local image viewing conditions and by the referent radiologist in good image viewing conditions. Importance of OD and image viewing conditions for diagnostic information were analysed. The survey showed that the main problem in Croatia is the lack of written quality assurance/quality control (QA/QC) procedures. Consequently, equipment performance, image quality and dose are unstable and activities to improve image quality or to reduce the dose are not evidence-based. This survey also had an educational purpose, introducing in Croatia the QC based on European Commission Guidelines.

  16. Higher glandular trichome density in tomato leaflets and repellence to spider mites Alta densidade de tricomas glandulares em tomateiro e aumento da repelência a ácaros rajados

    OpenAIRE

    Wilson Roberto Maluf; Irene Fumi Inoue; Raphael de Paula Duarte Ferreira; Luiz Antonio Augusto Gomes; Evaristo Mauro Castro; Maria das Graças Cardoso

    2007-01-01

    The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. h...

  17. Radiation doses in volume-of-interest breast computed tomography—A Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chao-Jen, E-mail: cjlai3711@gmail.com; Zhong, Yuncheng; Yi, Ying; Wang, Tianpeng; Shaw, Chris C. [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States)

    2015-06-15

    Purpose: Cone beam breast computed tomography (breast CT) with true three-dimensional, nearly isotropic spatial resolution has been developed and investigated over the past decade to overcome the problem of lesions overlapping with breast anatomical structures on two-dimensional mammographic images. However, the ability of breast CT to detect small objects, such as tissue structure edges and small calcifications, is limited. To resolve this problem, the authors proposed and developed a volume-of-interest (VOI) breast CT technique to image a small VOI using a higher radiation dose to improve that region’s visibility. In this study, the authors performed Monte Carlo simulations to estimate average breast dose and average glandular dose (AGD) for the VOI breast CT technique. Methods: Electron–Gamma-Shower system code-based Monte Carlo codes were used to simulate breast CT. The Monte Carlo codes estimated were validated using physical measurements of air kerma ratios and point doses in phantoms with an ion chamber and optically stimulated luminescence dosimeters. The validated full cone x-ray source was then collimated to simulate half cone beam x-rays to image digital pendant-geometry, hemi-ellipsoidal, homogeneous breast phantoms and to estimate breast doses with full field scans. 13-cm in diameter, 10-cm long hemi-ellipsoidal homogeneous phantoms were used to simulate median breasts. Breast compositions of 25% and 50% volumetric glandular fractions (VGFs) were used to investigate the influence on breast dose. The simulated half cone beam x-rays were then collimated to a narrow x-ray beam with an area of 2.5 × 2.5 cm{sup 2} field of view at the isocenter plane and to perform VOI field scans. The Monte Carlo results for the full field scans and the VOI field scans were then used to estimate the AGD for the VOI breast CT technique. Results: The ratios of air kerma ratios and dose measurement results from the Monte Carlo simulation to those from the physical

  18. Physical methods for dose determinations in mammography

    International Nuclear Information System (INIS)

    There is small but significant risk of radiation induced carcinogenesis associated with mammography. High quality mammography is the best method of early breast cancer detection. Besides, image as a basic requirement for an effective diagnosis, radiation protection principles require the radiation dose to the imaged tissue to be as low as compatible with required image quality. Glandular tissues is the most radiosensitive, thus the evaluation of Mean Glandular Dose (MGD) is the most relevant factor for estimation of radiation risk as well as the comparison of performance at different mammographic machines. MGD was estimated using Entrance Surface Air KERMA at the breast surface Kf measured free in air and appropriate conversation factors. Under evaluation were eight mammographic machines at institute of radiology, Skopje and mammographic machines at the Health's centers in Vevchani, Bitola, Prilep, Negotino and Shtip. Estimated values of MGD do not exceed the European reference level (<2mGy), but it can not be generally concluded for all mammography units in Macedonia, until their examination. In the near future all mammography units will be subject of Q C tests and dose measurements. (Author)

  19. Autofluorescence as a Signal to Sort Developing Glandular Trichomes by Flow Cytometry.

    Science.gov (United States)

    Bergau, Nick; Navarette Santos, Alexander; Henning, Anja; Balcke, Gerd U; Tissier, Alain

    2016-01-01

    The industrial relevance of a number of metabolites produced in plant glandular trichomes (GTs) has spurred research on these specialized organs for a number of years. Most of the research, however, has focused on the elucidation of secondary metabolite pathways and comparatively little has been undertaken on the development and differentiation of GTs. One way to gain insight into these developmental processes is to generate stage-specific transcriptome and metabolome data. The difficulty for this resides in the isolation of early stages of development of the GTs. Here we describe a method for the separation and isolation of intact young and mature type VI trichomes from the wild tomato species Solanum habrochaites. The final and key step of the method uses cell sorting based on distinct autofluorescence signals of the young and mature trichomes. We demonstrate that sorting by flow cytometry allows recovering pure fractions of young and mature trichomes. Furthermore, we show that the sorted trichomes can be used for transcript and metabolite analyses. Because many plant tissues or cells have distinct autofluorescence components, the principles of this method can be generally applicable for the isolation of specific cell types without prior labeling. PMID:27446176

  20. Cistitis quística glandular presentada como cistopatía quística

    Directory of Open Access Journals (Sweden)

    Claudio Orlich-Castelán

    2015-03-01

    Full Text Available Se presenta el caso de una mujer de 73 años, con historia de hematuria macroscópica de aparición reciente, con presencia de quistes en toda la extensión de la mucosa vesical, y con diagnóstico por biopsias de vejiga, de una cistitis glandular. Se habla de cistopatía quística cuando los quistes se encuentran difusamente en la vejiga, y frecuentemente coexiste con lipomatosis pélvica en pacientes obesas, como la que reportada aquí. Es considerada una lesión premaligna y por eso es importante un seguimiento cuidadoso con cistoscopias periódicas. La cistitis quística se presenta más frecuentemente en hombres y en personas de mayor edad. Macroscópicamente, se manifiesta con nódulos submucosos únicos o múltiples, y los hallazgos histológicos son la presencia de nidos uroteliales redondeados, con dilatación quística dentro de la lámina propia, y paralelos a la superficie urotelial.

  1. Single-cell analysis of glandular T cell receptors in Sjögren’s syndrome

    Science.gov (United States)

    Joachims, Michelle L.; Leehan, Kerry M.; Lawrence, Christina; Pelikan, Richard C.; Moore, Jacen S.; Pan, Zijian; Rasmussen, Astrid; Radfar, Lida; Lewis, David M.; Grundahl, Kiely M.; Kelly, Jennifer A.; Wiley, Graham B.; Shugay, Mikhail; Chudakov, Dmitriy M.; Lessard, Christopher J.; Stone, Donald U.; Scofield, R. Hal; Montgomery, Courtney G.; Sivils, Kathy L.; Thompson, Linda F.; Farris, A. Darise

    2016-01-01

    CD4+ T cells predominate in salivary gland (SG) inflammatory lesions in Sjögren’s syndrome (SS). However, their antigen specificity, degree of clonal expansion, and relationship to clinical disease features remain unknown. We used multiplex reverse-transcriptase PCR to amplify paired T cell receptor α (TCRα) and β transcripts of single CD4+CD45RA− T cells from SG and peripheral blood (PB) of 10 individuals with primary SS, 9 of whom shared the HLA DR3/DQ2 risk haplotype. TCRα and β sequences were obtained from a median of 91 SG and 107 PB cells per subject. The degree of clonal expansion and frequency of cells expressing two productively rearranged α genes were increased in SG versus PB. Expanded clones from SG exhibited complementary-determining region 3 (CDR3) sequence similarity both within and among subjects, suggesting antigenic selection and shared antigen recognition. CDR3 similarities were shared among expanded clones from individuals discordant for canonical Ro and La autoantibodies, suggesting recognition of alternative SG antigen(s). The extent of SG clonal expansion correlated with reduced saliva production and increased SG fibrosis, linking expanded SG T cells with glandular dysfunction. Knowledge of paired TCRα and β sequences enables further work toward identification of target antigens and development of novel therapies. PMID:27358913

  2. Localization of sesquiterpene lactone biosynthesis in cells of capitate glandular trichomes of Helianthus annuus (Asteraceae).

    Science.gov (United States)

    Amrehn, Evelyn; Aschenbrenner, Anna-Katharina; Heller, Annerose; Spring, Otmar

    2016-03-01

    Capitate glandular trichomes (CGT) of sunflower, Helianthus annuus, synthesize bioactive sesquiterpene lactones (STLs) within a short period of only a few days during trichome development. In the current project, the subcellular localization of H. annuus germacrene A monooxygenase (HaGAO), a key enzyme of the STL biosynthesis in sunflower CGT, was investigated. A polyclonal antibody raised against this enzyme was used for immunolabelling. HaGAO was found in secretory and stalk cells of CGT. This correlated with the appearance of smooth endoplasmic reticulum in both cell types. Stalk cells and secretory cells differed in form, size and types of plastids, but both had structures necessary for secretion. No HaGAO-specific immunoreaction was found in sunflower leaf tissue outside of CGT or in developing CGT before the secretory phase had started. Our results indicated that not only secretory cells but also nearly all cells of the CGT were involved in the biosynthesis of STL and that this process was not linked to the presence or absence of a specific type of plastid. PMID:25956500

  3. Autofluorescence as a Signal to Sort Developing Glandular Trichomes by Flow Cytometry

    Science.gov (United States)

    Bergau, Nick; Navarette Santos, Alexander; Henning, Anja; Balcke, Gerd U.; Tissier, Alain

    2016-01-01

    The industrial relevance of a number of metabolites produced in plant glandular trichomes (GTs) has spurred research on these specialized organs for a number of years. Most of the research, however, has focused on the elucidation of secondary metabolite pathways and comparatively little has been undertaken on the development and differentiation of GTs. One way to gain insight into these developmental processes is to generate stage-specific transcriptome and metabolome data. The difficulty for this resides in the isolation of early stages of development of the GTs. Here we describe a method for the separation and isolation of intact young and mature type VI trichomes from the wild tomato species Solanum habrochaites. The final and key step of the method uses cell sorting based on distinct autofluorescence signals of the young and mature trichomes. We demonstrate that sorting by flow cytometry allows recovering pure fractions of young and mature trichomes. Furthermore, we show that the sorted trichomes can be used for transcript and metabolite analyses. Because many plant tissues or cells have distinct autofluorescence components, the principles of this method can be generally applicable for the isolation of specific cell types without prior labeling. PMID:27446176

  4. Glandular odontogenic cyst mimicking ameloblastoma in a 78 year old female: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Do; Lee, Wan; Kwon, Kyung Hwan; Choi, Moon Ki; Choi, Eun Joo [College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Yoon, Jung Hoon [Dept. of Oral and Maxillofacial Pathology, College of Dentistry, Daejeon Dental Hospital, Wonkwang University, Daejeon (Korea, Republic of)

    2014-09-15

    Glandular odontogenic cyst (GOC) is a rare, potentially aggressive jaw lesion. The common radiographic features include a well-defined radiolucency with distinct borders, presenting a uni- or multilocular appearance. A cystic lesion in the posterior mandible of a 78-year-old female was incidentally found. Radiographs showed a unilocular lesion with a scalloped margin, external root resorption of the adjacent tooth, and cortical perforation. This lesion had changed from a small ovoid shape to a more expanded lesion in a period of four years. The small lesion showed unilocularity with a smooth margin and a well-defined border, but the expanded lesion produced cortical perforation and a lobulated margin. The provisional diagnosis was an ameloblastoma, whereas the histopathological examination revealed a GOC. This was a quite rare case, given that this radiographic change was observed in the posterior mandible of an elderly female. This case showed that a GOC can grow even in people in their seventies, changing from the unilocular form to an expanded, lobulated lesion. Here, we report a case of GOC with characteristic radiographic features.

  5. GEOPHYSICS, ASTRONOMY AND ASTROPHYSICS: Second-harmonic generation as a DNA malignancy indicator of prostate glandular epithelial cells

    Science.gov (United States)

    Zhuang, Zheng-Fei; Liu, Han-Ping; Guo, Zhou-Yi; Zhuo, Shuang-Mu; Yu, Bi-Ying; Deng, Xiao-Yuan

    2010-04-01

    This paper first demonstrates second-harmonic generation (SHG) in the intact cell nucleus, which acts as an optical indicator of DNA malignancy in prostate glandular epithelial cells. Within a scanning region of 2.7 μm×2.7 μm in cell nuclei, SHG signals produced from benign prostatic hyperplasia (BPH) and prostate carcinoma (PC) tissues (mouse model C57BL/6) have been investigated. Statistical analyses (t test) of a total of 405 measurements (204 nuclei from BPH and 201 nuclei from PC) show that SHG signals from BPH and PC have a distinct difference (p prostate glandular epithelial cells based upon induced biochemical and/or biophysical modifications in DNA.

  6. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Directory of Open Access Journals (Sweden)

    Allison L Speer

    Full Text Available The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10 and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b, in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22 except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  7. Dissociating Averageness and Attractiveness: Attractive Faces Are Not Always Average

    Science.gov (United States)

    DeBruine, Lisa M.; Jones, Benedict C.; Unger, Layla; Little, Anthony C.; Feinberg, David R.

    2007-01-01

    Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments…

  8. Dose assessment in contrast enhanced digital mammography using simple phantoms simulating standard model breasts

    Science.gov (United States)

    Bouwman, R. W.; van Engen, R. E.; Young, K. C.; Veldkamp, W. J. H.; Dance, D. R.

    2015-01-01

    Slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE) slabs are used to simulate standard model breasts for the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT). These phantoms are optimized for the energy spectra used in DM and DBT, which normally have a lower average energy than used in contrast enhanced digital mammography (CEDM). In this study we have investigated whether these phantoms can be used for the evaluation of AGD with the high energy x-ray spectra used in CEDM. For this purpose the calculated values of the incident air kerma for dosimetry phantoms and standard model breasts were compared in a zero degree projection with the use of an anti scatter grid. It was found that the difference in incident air kerma compared to standard model breasts ranges between -10% to +4% for PMMA slabs and between 6% and 15% for PMMA-PE slabs. The estimated systematic error in the measured AGD for both sets of phantoms were considered to be sufficiently small for the evaluation of AGD in quality control procedures for CEDM. However, the systematic error can be substantial if AGD values from different phantoms are compared.

  9. A proposal for chemical characterization and quality evaluation of botanical raw materials using glandular trichome microsampling of yacón (Polymnia sonchifolia, Asteraceae), an Andean medicinal plant

    OpenAIRE

    K. Schorr; F.B. Da Costa

    2003-01-01

    A proposal for chemical characterisation and quality evaluation of botanical raw materials by analysing the glandular trichomes from the leaves of two different populations of yacón (Polymnia sonchifolia Poeppig & Endlicher, Asteraceae) is described. This species is an Andean medicinal plant and the tea prepared with their leaves displays hypoglycemic property. The method was based on the glandular trichome microsampling using LC/DAD. Qualitative chromatographic fingerprints of the glands wer...

  10. Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images

    OpenAIRE

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Schuman, Joel S.

    2016-01-01

    Purpose Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Methods Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to...

  11. Oncoplastic Resection of Retroareolar Breast Cancer: Central Quadrantectomy and Reconstruction by Local Skin-Glandular Flap

    International Nuclear Information System (INIS)

    Background: Patients with central breast neoplasms account for 5 to 20% of breast cancer cases and, for a long time, they have been denied Breast Conservation Surgery (BCS) and conventionally treated with mastectomy. The high incidence of Nipple-Areola-Complex (NAC) involvement usually associated with these tumors necessitates nipple and areolar resection together with an adequate safety margin around the tumor, which yields an unacceptable cosmetic result. With the help of Oncoplastic Surgical Techniques, BCS can be offered to these patients. In this study central quadrantectomy and breast reconstruction by an infero-Iaterally based pedicled flap were evaluated. Patients and Methods: This study comprised 23 women with central breast tumors treated at the National Cancer Institute (NC]), Cairo University and at the Aswan Cancer Center, Egyptian Ministry of Health. Their ages ranged from 31 to 62 years (mean: 48.4±10.2 years). Twenty-two had a palpable mass, while only I had Paget's disease of the nipple without mass. The size of their tumors ranged from 4 to 33mm (mean: 16.9±8.6mm). Only 9 women showed clinical suspicion of NAC involvement in the form of nipple retraction. Seventeen cases had their tumors strictly in the retro-areolar region, while 5 had tumors extending for a maximum of I.5Cm beyond the areolar edge. All patients underwent central quadrantec-tomy with NAC resection removing a cylinder of breast tissue reaching down to the pectoral muscle together with axillary dissection. Advancement of an infero-Iaterally based skin-glandular flap was then carried out. All patients received adjuvant radiotherapy with or without chemotherapy or hormonal therapy. Results: Fourteen patients showed pathological evidence of nipple infiltration (60.8%). The free safety margin (SM) ranged from 9 to 13mm (mean: 10. 0.9mm). This could be accomplished from the first attempt in 18 patients; however, in 5 patients a second wider excision was needed to obtain an adequate

  12. Negative ion 'chip-based' nanospray tandem mass spectrometry for the analysis of flavonoids in glandular trichomes of Lychnophora ericoides Mart. (Asteraceae).

    Science.gov (United States)

    Gobbo-Neto, Leonardo; Gates, Paul J; Lopes, Norberto P

    2008-12-01

    This paper reports a method for the analysis of secondary metabolites stored in glandular trichomes, employing negative ion 'chip-based' nanospray tandem mass spectrometry. The analyses of glandular trichomes from Lychnophora ericoides, a plant endemic to the Brazilian 'cerrado' and used in traditional medicine as an anti-inflammatory and analgesic agent, led to the identification of five flavonoids (chrysin, pinocembrin, pinostrobin, pinobanksin and 3-O-acetylpinobanksin) by direct infusion of the extracts of glandular trichomes into the nanospray ionisation source. All the flavonoids have no oxidation at ring B, which resulted in a modification of the fragmentation pathways compared with that of the oxidised 3,4-dihydroflavonoids already described in the literature. The absence of the anti-inflammatory and antioxidant di-C-glucosylflavone vicenin-2, or any other flavonoid glycosides, in the glandular trichomes was also demonstrated. The use of the 'chip-based' nanospray QqTOF apparatus is a new fast and useful tool for the identification of secondary metabolites stored in the glandular trichomes, which can be useful for chemotaxonomic studies based on metabolites from glandular trichomes. PMID:18980260

  13. A computational approach to resolve cell level contributions to early glandular epithelial cancer progression

    Directory of Open Access Journals (Sweden)

    Park Sunwoo

    2009-12-01

    Full Text Available Abstract Background Three-dimensional (3D embedded cell cultures provide an appropriate physiological environment to reconstruct features of early glandular epithelial cancer. Although these are orders of magnitude simpler than tissues, they too are complex systems that have proven challenging to understand. We used agent-based, discrete event simulation modeling methods to build working hypotheses of mechanisms of epithelial 3D culture phenotype and early cancer progression. Starting with an earlier software analogue, we validated an improved in silico epithelial analogue (ISEA for cardinal features of a normally developed MDCK cyst. A set of axiomatic operating principles defined simulated cell actions. We explored selective disruption of individual simulated cell actions. New framework features enabled recording detailed measures of ISEA cell activities and morphology. Results Enabled by a small set of cell operating principles, ISEA cells multiplied and self-organized into cyst-like structures that mimicked those of MDCK cells in a 3D embedded cell culture. Selective disruption of "anoikis" or directional cell division caused the ISEA to develop phenotypic features resembling those of in vitro tumor reconstruction models and cancerous tissues in vivo. Disrupting either process, or both, altered cell activity patterns that resulted in morphologically similar outcomes. Increased disruption led to a prolonged presence of intraluminal cells. Conclusions ISEA mechanisms, behaviors, and morphological properties may have biological counterparts. To the extent that in silico-to-in vitro mappings are valid, the results suggest plausible, additional mechanisms of in vitro cancer reconstruction or reversion, and raise potentially significant implications for early cancer diagnosis based on histology. Further ISEA development and use are expected to provide a viable platform to complement in vitro methods for unraveling the mechanistic basis of

  14. Predominant Glandular Cholinergic Dysautonomia in Patients with Primary Sjögren’s Syndrome

    Science.gov (United States)

    Imrich, Richard; Alevizos, Ilias; Bebris, Lolita; Goldstein, David S.; Holmes, Courtney S.; Illei, Gabor G.; Nikolov, Nikolay P.

    2015-01-01

    Objectives The autonomic nervous system (ANS) modulates exocrine gland function. Available data show poor correlation between the degree of exocrine gland function and destruction in primary Sjögren’s syndrome (pSS) suggesting other mechanisms, such as autonomic dysfunction may be important in these patients. We performed a comprehensive analysis of sympathoneural and sympathetic cholinergic function in well-characterized patients with pSS. Methods 21 pSS patients (mean±SE age 44±3 years) and in 13 healthy controls (51±2 years) were assessed during orthostasis and intravenous injection of edrophonium (10 mg). The postganglionic sympathetic cholinergic system was evaluated by assessing sweat production by the quantitative sudomotor axon reflex test (QSART). Gastric empting testing assessed the gastro-intestinal ANS in pSS patients. Results Velocity index and acceleration index were significantly higher (p<0.05) in pSS compared to controls before and during the orthostatic and edrophonium tests. Other hemodynamic and neurochemical parameters did not differ between pSS patients and controls during the orthostasis and edrophonium test, however, edrophonium-induced saliva increment was lower in pSS (p=0.002). Abnormally low sweat production was found in four (N=4) pSS patients but in none of the controls in the QSART. Gastric empting was delayed in 53 % of pSS patients. Conclusion We observed subtle differences in several ANS domains, including gastrointestinal and sympathocholinergic system suggesting a complex ANS dysfunction in pSS. The impact was the largest on the exocrine glands with subtle differences in the cardiac parasympathetic function independent of glandular inflammation and atrophy, suggesting an alternative pathogenesis mechanism of the disease in pSS. PMID:25622919

  15. Glandular odontogenic cyst – Literature review and report of a paediatric case

    Science.gov (United States)

    Faisal, Mohammad; Ahmad, Syed Ansar; Ansari, Uzma

    2015-01-01

    Glandular odontogenic cyst (GOC) is an extremely rare lesion occurring in the jawbones. The present paper is a review of 181 cases of GOCs reported in English literature, since it was first reported by Padayache and Van Wyk in 1987. Mandible was involved in 130 cases and maxilla in 51 cases. Anterior mandible was the most common area of involvement. Radiographic appearance was that of a unilocular radiolucency in 98 of 176 reported cases. Rest presented as multilocular radiolucency. Cortical expansion was observed in 136 of the 180 reported cases while cortex breach or perforation was seen in 81 cases. The treatment of choice was that of minor procedures that included enucleation with or without curettage, peripheral ostectomy, cryotherapy, etc. in 157 of the total 177 reported cases. Marginal jaw resection, segmental mandibulectomy etc. was reported in 20 cases. Although minor surgical procedures were the treatment of choice in most studies, two major studies of Kaplan et al. and Fowler et al. involving 111 and 46 cases, recorded a recurrence rate of 35.9 and 19.6%, respectively. The age range was between 11 and 82 years. The respective mean age of patients in the above mentioned studies was 45.7 for Kaplan's and 51 years for Fowler's whereas in our study, the mean age was 45.9 years. Very rarely does GOC presents itself in a paediatric patient. The paper also reports a case of an 11-year-old child whose histopathogy came out to be a case of a GOC. PMID:26587384

  16. A breast-specific, negligible-dose scatter correction technique for dedicated cone-beam breast CT: a physics-based approach to improve Hounsfield Unit accuracy

    International Nuclear Information System (INIS)

    The purpose of this research was to develop a method to correct the cupping artifact caused from x-ray scattering and to achieve consistent Hounsfield Unit (HU) values of breast tissues for a dedicated breast CT (bCT) system. The use of a beam passing array (BPA) composed of parallel-holes has been previously proposed for scatter correction in various imaging applications. In this study, we first verified the efficacy and accuracy using BPA to measure the scatter signal on a cone-beam bCT system. A systematic scatter correction approach was then developed by modeling the scatter-to-primary ratio (SPR) in projection images acquired with and without BPA. To quantitatively evaluate the improved accuracy of HU values, different breast tissue-equivalent phantoms were scanned and radially averaged HU profiles through reconstructed planes were evaluated. The dependency of the correction method on object size and number of projections was studied. A simplified application of the proposed method on five clinical patient scans was performed to demonstrate efficacy. For the typical 10–18 cm breast diameters seen in the bCT application, the proposed method can effectively correct for the cupping artifact and reduce the variation of HU values of breast equivalent material from 150 to 40 HU. The measured HU values of 100% glandular tissue, 50/50 glandular/adipose tissue, and 100% adipose tissue were approximately 46, −35, and −94, respectively. It was found that only six BPA projections were necessary to accurately implement this method, and the additional dose requirement is less than 1% of the exam dose. The proposed method can effectively correct for the cupping artifact caused from x-ray scattering and retain consistent HU values of breast tissues. (paper)

  17. The effect of magnification on the image quality and the radiation dose in X-ray digital mammography: a Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yu-Na; Kim, Hee-Joung; Park, Hye-Suk; Lee, Chang-Lae; Cho, Hyo-Min; Lee, Seung-Wan; Ryu, Hyun-Ju [Yonsei University, Wonju (Korea, Republic of)

    2010-09-15

    There have been many efforts to advance the technology of X-ray digital mammography in order to enhance the early detection of breast pathology. The purpose of this study was to evaluate image quality and the radiation dose after magnifying X-ray digital mammography using the Geant4 Application for Tomographic Emission (GATE). In this study, we simulated a Monte Carlo model of an X-ray digital mammographic system, and we present a technique for magnification and discuss how it affects the image quality. The simulated X-ray digital mammographic system with GATE consists of an X-ray source, a compression paddle, a supporting plate, and an imaging plate (IP) of computed radiography (CR). The degree of magnification ranged from 1.0 to 2.0. We designed a semi-cylindrical phantom with a thickness of 45-mm and a radius of 50-mm in order to evaluate the image quality after magnification. The phantom was made of poly methyl methacrylate (PMMA) and contained four spherical specks with diameters of 750, 500, 250, and 100-{mu}m to simulate microcalcifications. The simulation studies were performed with an X-ray energy spectrum calculated using the spectrum processor SRS-78. A combination of a molybdenum anode and a molybdenum filter (Mo/Mo) was used for the mammographic X-ray tubes. The effects of the degree of magnification were investigated in terms of both the contrast-to-noise ratio (CNR) and the average glandular dose (AGD). The results show that the CNR increased as the degree of magnification increased and decreased as breast glandularity increased. The AGD showed only a minor increase with magnification. Based on the results, magnification of mammographic images can be used to obtain high image quality with an increased CNR. Our X-ray digital mammographic system model with GATE may be used as a basis for future studies on X-ray imaging characteristics.

  18. A breast-specific, negligible-dose scatter correction technique for dedicated cone-beam breast CT: a physics-based approach to improve Hounsfield Unit accuracy

    Science.gov (United States)

    Yang, Kai; Burkett, George, Jr.; Boone, John M.

    2014-11-01

    The purpose of this research was to develop a method to correct the cupping artifact caused from x-ray scattering and to achieve consistent Hounsfield Unit (HU) values of breast tissues for a dedicated breast CT (bCT) system. The use of a beam passing array (BPA) composed of parallel-holes has been previously proposed for scatter correction in various imaging applications. In this study, we first verified the efficacy and accuracy using BPA to measure the scatter signal on a cone-beam bCT system. A systematic scatter correction approach was then developed by modeling the scatter-to-primary ratio (SPR) in projection images acquired with and without BPA. To quantitatively evaluate the improved accuracy of HU values, different breast tissue-equivalent phantoms were scanned and radially averaged HU profiles through reconstructed planes were evaluated. The dependency of the correction method on object size and number of projections was studied. A simplified application of the proposed method on five clinical patient scans was performed to demonstrate efficacy. For the typical 10-18 cm breast diameters seen in the bCT application, the proposed method can effectively correct for the cupping artifact and reduce the variation of HU values of breast equivalent material from 150 to 40 HU. The measured HU values of 100% glandular tissue, 50/50 glandular/adipose tissue, and 100% adipose tissue were approximately 46, -35, and -94, respectively. It was found that only six BPA projections were necessary to accurately implement this method, and the additional dose requirement is less than 1% of the exam dose. The proposed method can effectively correct for the cupping artifact caused from x-ray scattering and retain consistent HU values of breast tissues.

  19. Average Convexity in Communication Situations

    NARCIS (Netherlands)

    Slikker, M.

    1998-01-01

    In this paper we study inheritance properties of average convexity in communication situations. We show that the underlying graph ensures that the graphrestricted game originating from an average convex game is average convex if and only if every subgraph associated with a component of the underlyin

  20. Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation.

    Science.gov (United States)

    Liu, Wenhui; Zheng, Xinmin; Qu, Zaiqing; Zhang, Ming; Zhou, Chun; Ma, Ling; Zhang, Yuanzhen

    2012-10-01

    This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm(2), ranging from 130 to 200 μW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 μW/cm(2), ranging from 400 to 700 μW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 μW/cm(2), ranging from 1200 to 1500 μW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (Pelectromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.

  1. Dual-energy contrast-enhanced digital mammography: patient radiation dose estimation using a Monte Carlo code

    International Nuclear Information System (INIS)

    Mammography is a standard procedure that facilitates breast cancer detection. Initial results of contrast-enhanced digital mammography (CEDM) are promising. The purpose of this study is to assess the CEDM radiation dose using a Monte Carlo code. EGSnrc MC code was used to simulate the interaction of photons with matter and estimate the glandular dose (Dg). A voxel female human phantom with a 2-8-cm breast thickness range and a breast glandular composition of 50 % was applied. Dg values ranged between 0.96 and 1.45 mGy (low and high energy). Dg values for a breast thickness of 5.0 cm and a glandular fraction of 50 % for craniocaudal and mediolateral oblique view were 1.12 (low energy image contribution is 0.98 mGy) and 1.07 (low energy image contribution is 0.95 mGy), respectively. The low kV part of CEDM is the main contributor to total glandular breast dose. (authors)

  2. The difference between alternative averages

    Directory of Open Access Journals (Sweden)

    James Vaupel

    2012-09-01

    Full Text Available BACKGROUND Demographers have long been interested in how compositional change, e.g., change in age structure, affects population averages. OBJECTIVE We want to deepen understanding of how compositional change affects population averages. RESULTS The difference between two averages of a variable, calculated using alternative weighting functions, equals the covariance between the variable and the ratio of the weighting functions, divided by the average of the ratio. We compare weighted and unweighted averages and also provide examples of use of the relationship in analyses of fertility and mortality. COMMENTS Other uses of covariances in formal demography are worth exploring.

  3. Fatty acid derivatives and dammarane triterpenes from the glandular trichome exudates of Ibicella lutea and Proboscidea louisiana.

    Science.gov (United States)

    Asai, Teigo; Hara, Noriyuki; Fujimoto, Yoshinori

    2010-06-01

    Ibicellalutea and Proboscidea louisiana, both of the Martyniaceae family, are known for rich glandular trichomes on their leaves and stems. Chemical investigations of the glandular trichome exudates on leaves of the two plants furnished three types of secondary metabolites, glycosylated fatty acids, glycerides (2-O-(3,6-diacetyloxyfattyacyl)glycerols and 2-O-(3-acetyloxyfattyacyl)glycerols) and dammarane triterpenes. The glycosylated fatty acids from I. lutea were determined to be 6(S)-(6-O-acetyl-beta-D-glucopyranosyloxy)-octadecanoic acid (1A), -eicosanoic acid (1B) and -docosanoic acid (1C), as well as their respective deacetyl congeners (2A, 2B and 2C), whereas P. louisiana furnished 8(S)-(6-O-acetyl-beta-D-glucopyranosyloxy)-eicosanoic acid (3A) and -docosanoic acid (3B) and their respective deacetyl congeners (4A and 4B), together with 2B. Both plants contained 12 identical 2-O-[(3R,6S)-3,6-diacetyloxyfattyacyl]glycerols (5A-L), in which the fatty acyl moieties contained between 17 and 21 carbon atoms. The corresponding mono-acetyloxy compounds, 2-O-[(3R)-3-acetyloxyfattyacyl]glycerols (6A-L) were detected in both plants. Among these glycerides, ten compounds (5A, 5C, 5F, 5H, 5K, 6A, 6C, 6F, 6H and 6K) had iso-fattyacyl structures and four (5E, 5J, 6E and 6J) had anteiso-fattyacyl structures. A previously unknown dammarane triterpene, betulatriterpene C 3-acetate (7), was isolated together with three known dammarane triterpenes, 24-epi-polacandrin 1,3-diacetate (8), betulatriterpene C (9) and 24-epi-polacandrin 3-acetate (10) from I. lutea, whereas 12 dammarane triterpenes, named probosciderols A-L (12-23), and the known compound betulafolienetriol (11) were isolated from P. louisiana. The structures of these compounds were elucidated by spectroscopic analysis including 2D-NMR techniques and chemical transformations. The 6-O-acetylglucosyloxy-fatty acids 1A-C (42%) and the dammarane triterpenes 7-10 (31%) were the two most abundant constituents in the

  4. Physical Theories with Average Symmetry

    CERN Document Server

    Alamino, Roberto C

    2013-01-01

    This Letter probes the existence of physical laws invariant only in average when subjected to some transformation. The concept of a symmetry transformation is broadened to include corruption by random noise and average symmetry is introduced by considering functions which are invariant only in average under these transformations. It is then shown that actions with average symmetry obey a modified version of Noether's Theorem with dissipative currents. The relation of this with possible violations of physical symmetries, as for instance Lorentz invariance in some quantum gravity theories, is briefly commented.

  5. Evidence for estrogen-dependent uterine serpin (SERPINA14) expression during estrus in the bovine endometrial glandular epithelium and lumen.

    Science.gov (United States)

    Ulbrich, Susanne E; Frohlich, Thomas; Schulke, Katy; Englberger, Eva; Waldschmitt, Nadine; Arnold, Georg J; Reichenbach, Horst-Dieter; Reichenbach, Myriam; Wolf, Eckhard; Meyer, Heinrich H D; Bauersachs, Stefan

    2009-10-01

    Uterine secretions have a dominant impact on the environment in which embryo development takes place. The uterine serpins (SERPINA14, previously known as UTMP) are found most abundantly during pregnancy in the uterus of ruminants. Although progesterone is currently assumed to be the major regulator of SERPINA14 expression, our recent study of transcriptome changes in bovine endometrium during the estrous cycle unexpectedly detected a marked upregulation of SERPINA14 mRNA levels at estrus. The present study describes the full-length mRNA sequence, genomic organization, and putative promoter elements of the SERPINA14 gene. The SERPINA14 mRNA abundance was quantified by real-time RT-PCR in intercaruncular endometrium at several time points during the estrous cycle and early pregnancy. Highest levels were found at estrus, followed by a dramatic decrease and a moderate expression during the luteal phase. Transcript levels were higher in pregnant endometrium compared with controls at Day 18. At estrus, immunoreactive protein was localized in deep glandular epithelium, and Western blotting concomitantly showed the 52-kDa form in uterine flushings. SERPINA14 mRNA was significantly upregulated in glandular endometrial cells in vitro after stimulation with estradiol-17beta and progesterone, but not after interferon-tau treatment. Our results clearly demonstrate that SERPINA14 appears distinctly in bovine endometrium during the estrus phase. A supporting role toward providing a well-prepared endometrial environment for passing gametes, especially sperm, is assumed. PMID:19494250

  6. Enjebi Island dose assessment

    International Nuclear Information System (INIS)

    We have updeated the radiological dose assessment for Enjebi Island at Enewetak Atoll using data derived from analysis of food crops grown on Enjebi. This is a much more precise assessment of potential doses to people resettling Enjebi Island than the 1980 assessment in which there were no data available from food crops on Enjebi. Details of the methods and data used to evaluate each exposure pathway are presented. The terrestrial food chain is the most significant potential exposure pathway and 137Cs is the radionuclide responsible for most of the estimated dose over the next 50 y. The doses are calculated assuming a resettlement date of 1990. The average wholebody maximum annual estimated dose equivalent derived using our diet model is 166 mremy;the effective dose equivalent is 169 mremy. The estimated 30-, 50-, and 70-y integral whole-body dose equivalents are 3.5 rem, 5.1 rem, and 6.2 rem, respectively. Bone-marrow dose equivalents are only slightly higher than the whole-body estimates in each case. The bone-surface cells (endosteal cells) receive the highest dose, but they are a less sensitive cell population and are less sensitive to fatal cancer induction than whole body and bone marrow. The effective dose equivalents for 30, 50, and 70 y are 3.6 rem, 5.3 rem, and 6.6 rem, respectively. 79 refs., 17 figs., 24 tabs

  7. Salivary gland acinar cells regenerate functional glandular structures in modified hydrogels

    Science.gov (United States)

    Pradhan, Swati

    Xerostomia, a condition resulting from irradiation of the head and neck, affects over 40,000 cancer patients each year in the United States. Direct radiation damage of the acinar cells that secrete fluid and protein results in salivary gland hypofunction. Present medical management for xerostomia for patients treated for upper respiratory cancer is largely ineffective. Patients who have survived their terminal diagnosis are often left with a diminished quality of life and are unable to enjoy the simple pleasures of eating and drinking. This project aims to ultimately reduce human suffering by developing a functional implantable artificial salivary gland. The goal was to create an extracellular matrix (ECM) modified hyaluronic acid (HA) based hydrogel culture system that allows for the growth and differentiation of salivary acinar cells into functional acini-like structures capable of secreting large amounts of protein and fluid unidirectionally and to ultimately engineer a functional artificial salivary gland that can be implanted into an animal model. A tissue collection protocol was established and salivary gland tissue was obtained from patients undergoing head and neck surgery. The tissue specimen was assessed by histology and immunohistochemistry to establish the phenotype of normal salivary gland cells including the native basement membranes. Hematoxylin and eosin staining confirmed normal glandular tissue structures including intercalated ducts, striated ducts and acini. alpha-Amylase and periodic acid schiff stain, used for structures with a high proportion of carbohydrate macromolecules, preferentially stained acinar cells in the tissue. Intercalated and striated duct structures were identified using cytokeratins 19 and 7 staining. Myoepithelial cells positive for cytokeratin 14 were found wrapped around the serous and mucous acini. Tight junction components including ZO-1 and E-cadherin were present between both ductal and acinar cells. Ductal and acinar

  8. Segmentation of the whole breast from low-dose chest CT images

    Science.gov (United States)

    Liu, Shuang; Salvatore, Mary; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2015-03-01

    The segmentation of whole breast serves as the first step towards automated breast lesion detection. It is also necessary for automatically assessing the breast density, which is considered to be an important risk factor for breast cancer. In this paper we present a fully automated algorithm to segment the whole breast in low-dose chest CT images (LDCT), which has been recommended as an annual lung cancer screening test. The automated whole breast segmentation and potential breast density readings as well as lesion detection in LDCT will provide useful information for women who have received LDCT screening, especially the ones who have not undergone mammographic screening, by providing them additional risk indicators for breast cancer with no additional radiation exposure. The two main challenges to be addressed are significant range of variations in terms of the shape and location of the breast in LDCT and the separation of pectoral muscles from the glandular tissues. The presented algorithm achieves robust whole breast segmentation using an anatomy directed rule-based method. The evaluation is performed on 20 LDCT scans by comparing the segmentation with ground truth manually annotated by a radiologist on one axial slice and two sagittal slices for each scan. The resulting average Dice coefficient is 0.880 with a standard deviation of 0.058, demonstrating that the automated segmentation algorithm achieves results consistent with manual annotations of a radiologist.

  9. "Pricing Average Options on Commodities"

    OpenAIRE

    Kenichiro Shiraya; Akihiko Takahashi

    2010-01-01

    This paper proposes a new approximation formula for pricing average options on commodities under a stochastic volatility environment. In particular, it derives an option pricing formula under Heston and an extended lambda-SABR stochastic volatility models (which includes an extended SABR model as a special case). Moreover, numerical examples support the accuracy of the proposed average option pricing formula.

  10. Quantized average consensus with delay

    NARCIS (Netherlands)

    Jafarian, Matin; De Persis, Claudio

    2012-01-01

    Average consensus problem is a special case of cooperative control in which the agents of the network asymptotically converge to the average state (i.e., position) of the network by transferring information via a communication topology. One of the issues of the large scale networks is the cost of co

  11. Gaussian moving averages and semimartingales

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas

    2008-01-01

    In the present paper we study moving averages (also known as stochastic convolutions) driven by a Wiener process and with a deterministic kernel. Necessary and sufficient conditions on the kernel are provided for the moving average to be a semimartingale in its natural filtration. Our results...... are constructive - meaning that they provide a simple method to obtain kernels for which the moving average is a semimartingale or a Wiener process. Several examples are considered. In the last part of the paper we study general Gaussian processes with stationary increments. We provide necessary and sufficient...

  12. Dosimetric characterization and organ dose assessment in digital breast tomosynthesis: Measurements and Monte Carlo simulations using voxel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Mariana, E-mail: marianabaptista@ctn.ist.utl.pt; Di Maria, Salvatore; Barros, Sílvia; Vaz, Pedro [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, Bobadela LRS 2695-066 (Portugal); Figueira, Catarina [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University, Belfast BT7 1NN (United Kingdom); Sarmento, Marta; Orvalho, Lurdes [Serviço de Imagiologia, Hospital da Luz, Avenida Lusíada, 100, Lisboa 1500-650 (Portugal)

    2015-07-15

    Purpose: Due to its capability to more accurately detect deep lesions inside the breast by removing the effect of overlying anatomy, digital breast tomosynthesis (DBT) has the potential to replace the standard mammography technique in clinical screening exams. However, the European Guidelines for DBT dosimetry are still a work in progress and there are little data available on organ doses other than to the breast. It is, therefore, of great importance to assess the dosimetric performance of DBT with respect to the one obtained with standard digital mammography (DM) systems. The aim of this work is twofold: (i) to study the dosimetric properties of a combined DBT/DM system (MAMMOMAT Inspiration Siemens{sup ®}) for a tungsten/rhodium (W/Rh) anode/filter combination and (ii) to evaluate organs doses during a DBT examination. Methods: For the first task, measurements were performed in manual and automatic exposure control (AEC) modes, using two homogeneous breast phantoms: a PMMA slab phantom and a 4 cm thick breast-shaped rigid phantom, with 50% of glandular tissue in its composition. Monte Carlo (MC) simulations were performed using Monte Carlo N-Particle eXtended v.2.7.0. A MC model was implemented to mimic DM and DBT acquisitions for a wide range of x-ray spectra (24 –34 kV). This was used to calculate mean glandular dose (MGD) and to compute series of backscatter factors (BSFs) that could be inserted into the DBT dosimetric formalism proposed by Dance et al. Regarding the second aim of the study, the implemented MC model of the clinical equipment, together with a female voxel phantom (“Laura”), was used to calculate organ doses considering a typical DBT acquisition. Results were compared with a standard two-view mammography craniocaudal (CC) acquisition. Results: Considering the AEC mode, the acquisition of a single CC view results in a MGD ranging from 0.53 ± 0.07 mGy to 2.41 ± 0.31 mGy in DM mode and from 0.77 ± 0.11 mGy to 2.28 ± 0.32 mGy in DBT mode

  13. False positive reaction due to endogenous biotin activity in glandular epithelium of decidua Reação falso positiva em epitélio glandular da decídua devido a atividade endógena de biotina

    Directory of Open Access Journals (Sweden)

    Liliana Cruz Spano

    2005-06-01

    Full Text Available Biotin-labeled probe was used in an in situ hybridisation assay to localize virus infection in formalin-fixed, paraffin embedded tissues taken from eleven abortion cases. Probes for human cytomegalovirus (HCMV, human Parvovirus B19 (B19 and human adenovirus type 2 (HAd2, were labeled with biotin-11-dUTP by nick-translation reaction. Streptavidin-alkaline-phosphatase (SAP was used to detect biotin, followed by 4-nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP solution. Positive reaction was observed in nucleus of glandular ephitelium cells of decidua either in positive or in negative control at first and second gestational trimester. The reaction was not inhibited with blocking solution for alkaline phosphatase endogenous activity and it persisted even with probes omission. The use of adequate negative control permitted to reveal the presence of nuclear biotin in glandular epithelium of decidua, responsible for false positivity in detection systems involving streptavidin biotin system (StrepABC. The stained cells resembled to cytophatic effect due to herpesvirus, which could induce further misinterpretation. The results obtained in this study strongly recommend that DNA detection by in situ hybridisation reaction in gestational endometrium should be done without using StrepABC system.Sondas marcadas com biotina foram utilizadas neste trabalho para detecção de infecção viral por hibridização in situ em tecidos fixados com formalina e embebidos em parafina de 11 casos obtidos de abortamento. Sondas para citomegalovírus humano (HCMV, parvovírus B19 humano (B19 e adenovírus humano tipo 2 (HAd2, foram marcadas com biotina-11-dUTP através da reação de nick-translation. Estreptavidina conjugada com fosfatase alcalina (SAP seguida por solução de 4-nitro-azul de tetrazolio/5-bromo-4-cloro-3-indolil fosfato (NBT/BCIP foram utilizadas para detecção da biotina após a reação de hibridização. Reação positiva foi

  14. Células glandulares atípicas e câncer de colo uterino: revisão sistemática Atypical glandular cells and cervical cancer: systematic review

    OpenAIRE

    Juliana Pedrosa de Holanda Marques; Lívia Bandeira Costa; Ana Paula de Souza e Pinto; Anacássia Fonseca de Lima; Maria Eugênia Leite Duarte; Ana Paula Fernandes Barbosa; Paloma Lys de Medeiros

    2011-01-01

    Atipias de células glandulares em esfregaços cervicovaginais é um achado citológico na rotina de rastreamento do câncer cervical, que aumentou nas últimas décadas. Sua constatação é importante clinicamente, pois é alta a percentagem de casos associados com doença cervical e endometrial de alto grau e câncer. Este trabalho avaliou, por meio de uma revisão sistemática, estudos que investigaram o perfil das lesões de colo uterino em avaliações histológicas de seguimento de pacientes já diagnosti...

  15. Power convergence of Abel averages

    OpenAIRE

    Kozitsky, Yuri; Shoikhet, David; Zemanek, Jaroslav

    2012-01-01

    Necessary and sufficient conditions are presented for the Abel averages of discrete and strongly continuous semigroups, $T^k$ and $T_t$, to be power convergent in the operator norm in a complex Banach space. These results cover also the case where $T$ is unbounded and the corresponding Abel average is defined by means of the resolvent of $T$. They complement the classical results by Michael Lin establishing sufficient conditions for the corresponding convergence for a bounded $T$.

  16. Effects of Plant Density on the Number of Glandular Trichomes and on Yield and Quality of Essential Oils from Oregano.

    Science.gov (United States)

    Tuttolomondo, Teresa; La Bella, Salvatore; Leto, Claudio; Bonsangue, Giuseppe; Leone, Raffaele; Gennaro, Maria Cristina; Virga, Giuseppe; Inguanta, Rosalinda; Licata, Mario

    2016-06-01

    Plants yields are influenced by agronomic techniques. Plant density is a complex issue and extremely important when maximizing both crop quality, and biomass and essential oil yields. Plants belonging to the Origanum vulgare subspecies hirtum (Link) Ietswaart were grown adopting four types of plant density and were characterized in biometric and chemical terms. The samples were analyzed using the ANOVA (Principal Component Analysis) statistical method regarding biometric aspects, EO yield and peltate hair density. Essential oil (EO) was extracted by hydrodistillation and analyzed using GC-FID and GC-MS. GC-FID and GC-MS analysis led to the identification of 45 compounds from the EO. Plant density affected production both in terms of biomass and EO. However, it was not found to have affected peltate glandular trichome density or EO quality. PMID:27534133

  17. Vocal attractiveness increases by averaging.

    Science.gov (United States)

    Bruckert, Laetitia; Bestelmeyer, Patricia; Latinus, Marianne; Rouger, Julien; Charest, Ian; Rousselet, Guillaume A; Kawahara, Hideki; Belin, Pascal

    2010-01-26

    Vocal attractiveness has a profound influence on listeners-a bias known as the "what sounds beautiful is good" vocal attractiveness stereotype [1]-with tangible impact on a voice owner's success at mating, job applications, and/or elections. The prevailing view holds that attractive voices are those that signal desirable attributes in a potential mate [2-4]-e.g., lower pitch in male voices. However, this account does not explain our preferences in more general social contexts in which voices of both genders are evaluated. Here we show that averaging voices via auditory morphing [5] results in more attractive voices, irrespective of the speaker's or listener's gender. Moreover, we show that this phenomenon is largely explained by two independent by-products of averaging: a smoother voice texture (reduced aperiodicities) and a greater similarity in pitch and timbre with the average of all voices (reduced "distance to mean"). These results provide the first evidence for a phenomenon of vocal attractiveness increases by averaging, analogous to a well-established effect of facial averaging [6, 7]. They highlight prototype-based coding [8] as a central feature of voice perception, emphasizing the similarity in the mechanisms of face and voice perception.

  18. Vocal attractiveness increases by averaging.

    Science.gov (United States)

    Bruckert, Laetitia; Bestelmeyer, Patricia; Latinus, Marianne; Rouger, Julien; Charest, Ian; Rousselet, Guillaume A; Kawahara, Hideki; Belin, Pascal

    2010-01-26

    Vocal attractiveness has a profound influence on listeners-a bias known as the "what sounds beautiful is good" vocal attractiveness stereotype [1]-with tangible impact on a voice owner's success at mating, job applications, and/or elections. The prevailing view holds that attractive voices are those that signal desirable attributes in a potential mate [2-4]-e.g., lower pitch in male voices. However, this account does not explain our preferences in more general social contexts in which voices of both genders are evaluated. Here we show that averaging voices via auditory morphing [5] results in more attractive voices, irrespective of the speaker's or listener's gender. Moreover, we show that this phenomenon is largely explained by two independent by-products of averaging: a smoother voice texture (reduced aperiodicities) and a greater similarity in pitch and timbre with the average of all voices (reduced "distance to mean"). These results provide the first evidence for a phenomenon of vocal attractiveness increases by averaging, analogous to a well-established effect of facial averaging [6, 7]. They highlight prototype-based coding [8] as a central feature of voice perception, emphasizing the similarity in the mechanisms of face and voice perception. PMID:20129047

  19. An audit of cervicovaginal cytology in a teaching hospital: Are atypical glandular cells under-recognised on cytological screening?

    Directory of Open Access Journals (Sweden)

    Crasta Julian

    2009-01-01

    Full Text Available Background: Cervical cytology screening for carcinoma of the cervix in India is mainly opportunistic in nature and is practiced mainly in urban centres. The effectiveness of cervical cytology screening depends on various factors. The quality of cervicovaginal cytology service is assessed by various quality indices and by cyto-histology correlation, which is the most important quality assurance measure. Aims: To describe the cervical cytology diagnoses, estimate the quality indices, and evaluate the discrepant cases on cytohistological correlation. Settings and Design: Retrospective observational study from a tertiary care centre in South India. Materials and Methods: Using a database search, all the cervicovaginal cytology reported during the period of 2002-2006 was retrieved and various diagnoses were described. The data was analysed to assess the quality indices. The cytohistologically discrepant cases were reviewed. Results: A total of 10,787 cases were retrieved, of which 98.14% were labeled negative and 1.36% were unsatisfactory for evaluation. A few (0.81% of the cases were labeled as squamous intraepithelial lesions and 0.38% as atypical squamous cells. The ASCUS: SIL ratio was 0.5. Cytohistological correlation revealed a total of ten cases with significant discrepancy. The majority of these were carcinomas that were misdiagnosed as atypical glandular cells. These cytology smears and the subsequent biopsies were reviewed to elucidate the reasons for the discrepancies. Conclusions: The cervical cytology service at our centre is well within the accepted standards. An increased awareness of cytological features, especially of glandular lesions, a good clinician-laboratory communication and a regular cytohistological review would further improve the diagnostic standards.

  20. Sparsity Averaging for Compressive Imaging

    CERN Document Server

    Carrillo, Rafael E; Van De Ville, Dimitri; Thiran, Jean-Philippe; Wiaux, Yves

    2012-01-01

    We propose a novel regularization method for sparse image reconstruction from compressive measurements. The approach relies on the conjecture that natural images exhibit strong average sparsity over multiple coherent frames. The associated reconstruction algorithm, based on an analysis prior and a reweighted $\\ell_1$ scheme, is dubbed Sparsity Averaging Reweighted Analysis (SARA). We test our prior and the associated algorithm through extensive numerical simulations for spread spectrum and Gaussian acquisition schemes suggested by the recent theory of compressed sensing with coherent and redundant dictionaries. Our results show that average sparsity outperforms state-of-the-art priors that promote sparsity in a single orthonormal basis or redundant frame, or that promote gradient sparsity. We also illustrate the performance of SARA in the context of Fourier imaging, for particular applications in astronomy and medicine.

  1. Dependability in Aggregation by Averaging

    CERN Document Server

    Jesus, Paulo; Almeida, Paulo Sérgio

    2010-01-01

    Aggregation is an important building block of modern distributed applications, allowing the determination of meaningful properties (e.g. network size, total storage capacity, average load, majorities, etc.) that are used to direct the execution of the system. However, the majority of the existing aggregation algorithms exhibit relevant dependability issues, when prospecting their use in real application environments. In this paper, we reveal some dependability issues of aggregation algorithms based on iterative averaging techniques, giving some directions to solve them. This class of algorithms is considered robust (when compared to common tree-based approaches), being independent from the used routing topology and providing an aggregation result at all nodes. However, their robustness is strongly challenged and their correctness often compromised, when changing the assumptions of their working environment to more realistic ones. The correctness of this class of algorithms relies on the maintenance of a funda...

  2. Stochastic Approximation with Averaging Innovation

    CERN Document Server

    Laruelle, Sophie

    2010-01-01

    The aim of the paper is to establish a convergence theorem for multi-dimensional stochastic approximation in a setting with innovations satisfying some averaging properties and to study some applications. The averaging assumptions allow us to unify the framework where the innovations are generated (to solve problems from Numerical Probability) and the one with exogenous innovations (market data, output of "device" $e.g.$ an Euler scheme) with stationary or ergodic properties. We propose several fields of applications with random innovations or quasi-random numbers. In particular we provide in both setting a rule to tune the step of the algorithm. At last we illustrate our results on five examples notably in Finance.

  3. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    J C Travers

    2010-11-01

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium. The most common experimental arrangements are described, including both continuous wave fibre laser systems with over 100 W pump power, and picosecond mode-locked, master oscillator power fibre amplifier systems, with over 10 kW peak pump power. These systems can produce broadband supercontinua with over 50 and 1 mW/nm average spectral power, respectively. Techniques for numerical modelling of the supercontinuum sources are presented and used to illustrate some supercontinuum dynamics. Some recent experimental results are presented.

  4. Dose limits

    International Nuclear Information System (INIS)

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  5. Michel Parameters averages and interpretation

    International Nuclear Information System (INIS)

    The new measurements of Michel parameters in τ decays are combined to world averages. From these measurements model independent limits on non-standard model couplings are derived and interpretations in the framework of specific models are given. A lower limit of 2.5 tan β GeV on the mass of a charged Higgs boson in models with two Higgs doublets can be set and a 229 GeV limit on a right-handed W-boson in left-right symmetric models (95 % c.l.)

  6. Structure and Development of Glandular Trichomes in Pelargonium fragrans%肉豆蔻天竺葵腺毛结构及其发育的研究

    Institute of Scientific and Technical Information of China (English)

    李大红; 姚雷

    2005-01-01

    肉豆蔻天竺葵是一种含有精油的植物,其精油被广泛应用于香料与化妆品.然而其精油的产生部位腺毛的结构与发育过程尚未有研究,本文应用光学显微镜、扫描电子显微镜、透视电子显微镜对肉豆蔻天竺葵腺毛结构及其发育过程进行了研究.结果表明:在肉豆蔻天竺葵叶的表皮上具有腺体毛和非腺体毛两种结构形态.在研究中发现,肉豆蔻天竺葵只有头状腺毛(由头细胞、柄细胞和基细胞三个部分组成),其头状腺毛可以分为两种类型:类型Ⅰ和类型Ⅱ.肉豆蔻天竺葵腺毛是由表皮细胞发育而来.%Pelargoniumfragrans is cultivated as a source of essential oil as well as used for food flavouring or cosmetics. However, the structure and development of the organ that produce essential oil, glandular hair, in Pelargonium fragrans is still unknown. In this study, the structure and development of the glandular trichomes in the epidermis of Pelargonium fragrans were studied by light microscopy as well as scanning and transmission electron microscopy. The surfaces of young leaves were only covered by small number of non-glandular trichomes. As the leaf fully expanding, the amount of the non-glandular trichomes increased. The glandular trichomes are cspitate ones and two morphological types could be distinguished, type Ⅰ and Ⅱ. Development of the glandular trichome started with an outgrowth of an epidermal cell.

  7. Breast dosimetry system in screen/film mammography

    OpenAIRE

    Goto, Sachiko; Azuma, Yoshiharu; Toshinori MARUYAMA; Nakagiri, Yoshitada; TAKEDA, Yoshihiro; Sugita, Katsuhiko; Kadohisa, Shigefumi

    2000-01-01

    The average glandular dose to glandular tissue m mammography is generally assumed to be a function of beam quality (HVL), x-ray tube target material, tube voltage, breast thickness, breast composition and, to a lesser extent, x-ray tube voltage waveform. The average glandular dose is generally determined from published tables with knowledge of the above function. Tables for a high frequency x-ray generator are not yet published. In our study, the lookup tables for the average glandular dose w...

  8. The evaluation of radiation dose by exposure method in digital magnification mammography

    International Nuclear Information System (INIS)

    In digital mammography, Exposure factor were automatically chosen using by measurement breast thickness and the density of mammary gland. It may cause a increase glandular dose. The purpose of this study was to investigate optimal image quality in digital magnification mammography to decrease radiation exposure of patient dose. Auto mode gives the best image quality however, AGD showed better image quality. Image quality of manual mode passed phantom test and SNR at 55% mAs of auto mode commonly used in the digital magnification mammography. Also it could reduce AGD. According to result, manual mode may reduce the unnecessary radiation exposure in digital magnification mammography

  9. The evaluation of radiation dose by exposure method in digital magnification mammography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young [Dankook Univ. Hospital, Cheonan (Korea, Republic of); Kim, Hwa Sun [Ansan Univ., Ansan (Korea, Republic of)

    2012-12-15

    In digital mammography, Exposure factor were automatically chosen using by measurement breast thickness and the density of mammary gland. It may cause a increase glandular dose. The purpose of this study was to investigate optimal image quality in digital magnification mammography to decrease radiation exposure of patient dose. Auto mode gives the best image quality however, AGD showed better image quality. Image quality of manual mode passed phantom test and SNR at 55% mAs of auto mode commonly used in the digital magnification mammography. Also it could reduce AGD. According to result, manual mode may reduce the unnecessary radiation exposure in digital magnification mammography.

  10. Utirik Atoll Dose Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Conrado, C.L.; Bogen, K.T

    1999-10-06

    On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other

  11. Monte Carlo simulations to assess the effects of tube current modulation on breast dose for multidetector CT

    OpenAIRE

    Angel, Erin; Yaghmai, Nazanin; Jude, Cecilia Matilda; Demarco, John J.; Cagnon, Christopher H.; Goldin, Jonathan G; Primak, Andrew N.; Stevens, Donna M.; Cody, Dianna D.; McCollough, Cynthia H.; McNitt-Gray, Michael F.

    2009-01-01

    Tube current modulation was designed to reduce radiation dose in CT imaging while maintaining overall image quality. This study aims to develop a method for evaluating the effects of tube current modulation (TCM) on organ dose in CT exams of actual patient anatomy. This method was validated by simulating a TCM and a fixed tube current chest CT exam on 30 voxelized patient models and estimating the radiation dose to each patient’s glandular breast tissue. This new method for estimating organ d...

  12. Loss of vitamin D receptor signaling from the mammary epithelium or adipose tissue alters pubertal glandular development.

    Science.gov (United States)

    Johnson, Abby L; Zinser, Glendon M; Waltz, Susan E

    2014-10-15

    Vitamin D₃ receptor (VDR) signaling within the mammary gland regulates various postnatal stages of glandular development, including puberty, pregnancy, involution, and tumorigenesis. Previous studies have shown that vitamin D₃ treatment induces cell-autonomous growth inhibition and differentiation of mammary epithelial cells in culture. Furthermore, mammary adipose tissue serves as a depot for vitamin D₃ storage, and both epithelial cells and adipocytes are capable of bioactivating vitamin D₃. Despite the pervasiveness of VDR in mammary tissue, individual contributions of epithelial cells and adipocytes, as well as the VDR-regulated cross-talk between these two cell types during pubertal mammary development, have yet to be investigated. To assess the cell-type specific effect of VDR signaling during pubertal mammary development, novel mouse models with mammary epithelial- or adipocyte-specific loss of VDR were generated. Interestingly, loss of VDR in either cellular compartment accelerated ductal morphogenesis with increased epithelial cell proliferation and decreased apoptosis within terminal end buds. Conversely, VDR signaling specifically in the mammary epithelium modulated hormone-induced alveolar growth, as ablation of VDR in this cell type resulted in precocious alveolar development. In examining cellular cross-talk ex vivo, we show that ligand-dependent VDR signaling in adipocytes significantly inhibits mammary epithelial cell growth in part through the vitamin D₃-dependent production of the cytokine IL-6. Collectively, these studies delineate independent roles for vitamin D₃-dependent VDR signaling in mammary adipocytes and epithelial cells in controlling pubertal mammary gland development.

  13. Identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (Helianthus annuus L., Asteraceae).

    Science.gov (United States)

    Aschenbrenner, Anna-Katharina; Kwon, Moonhyuk; Conrad, Jürgen; Ro, Dae-Kyun; Spring, Otmar

    2016-04-01

    Sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. A bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. Based on sequence similarity with a known bisabolene synthases from Arabidopsis thaliana AtTPS12, candidate genes of Helianthus were searched in EST-database and used to design specific primers. PCR experiments identified two candidates in the RNA pool of linear glandular trichomes of sunflower. Their sequences contained the typical motifs of sesquiterpene synthases and their expression in yeast functionally characterized them as bisabolene synthases. Spectroscopic analysis identified the stereochemistry of the product of both enzymes as (Z)-γ-bisabolene. The origin of the two sunflower bisabolene synthase genes from the transcripts of linear trichomes indicates that they may be involved in the synthesis of sesquiterpenes produced in these trichomes. Comparison of the amino acid sequences of the sunflower bisabolene synthases showed high similarity with sesquiterpene synthases from other Asteracean species and indicated putative evolutionary origin from a β-farnesene synthase. PMID:26880289

  14. Flexible time domain averaging technique

    Science.gov (United States)

    Zhao, Ming; Lin, Jing; Lei, Yaguo; Wang, Xiufeng

    2013-09-01

    Time domain averaging(TDA) is essentially a comb filter, it cannot extract the specified harmonics which may be caused by some faults, such as gear eccentric. Meanwhile, TDA always suffers from period cutting error(PCE) to different extent. Several improved TDA methods have been proposed, however they cannot completely eliminate the waveform reconstruction error caused by PCE. In order to overcome the shortcomings of conventional methods, a flexible time domain averaging(FTDA) technique is established, which adapts to the analyzed signal through adjusting each harmonic of the comb filter. In this technique, the explicit form of FTDA is first constructed by frequency domain sampling. Subsequently, chirp Z-transform(CZT) is employed in the algorithm of FTDA, which can improve the calculating efficiency significantly. Since the signal is reconstructed in the continuous time domain, there is no PCE in the FTDA. To validate the effectiveness of FTDA in the signal de-noising, interpolation and harmonic reconstruction, a simulated multi-components periodic signal that corrupted by noise is processed by FTDA. The simulation results show that the FTDA is capable of recovering the periodic components from the background noise effectively. Moreover, it can improve the signal-to-noise ratio by 7.9 dB compared with conventional ones. Experiments are also carried out on gearbox test rigs with chipped tooth and eccentricity gear, respectively. It is shown that the FTDA can identify the direction and severity of the eccentricity gear, and further enhances the amplitudes of impulses by 35%. The proposed technique not only solves the problem of PCE, but also provides a useful tool for the fault symptom extraction of rotating machinery.

  15. Controllable dose

    International Nuclear Information System (INIS)

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  16. Breast compression and radiation dose in two different mammographic oblique projections: 45 and 60 deg

    Energy Technology Data Exchange (ETDEWEB)

    Brnic, Zoran; Hebrang, Andrija

    2001-10-01

    Introduction: Standard mammography includes two views, craniocaudal and medio-lateral oblique. Depending on patient's body constitution, central beam angle in mediolateral oblique projection may vary, with 45 deg. being suitable for the majority of patients in routine daily practice. With continuous improvement in X-ray technology and radiographers' training, the risk of radiation induced cancerogenesis is considerably reduced and acceptable when compared to benefit. However, the risk still exists, being cumulative and directly related to absorbed glandular dose. There is no minimal dose of radiation which is absolutely harmless, and every effort to reduce the dose is welcome. In this retrospective study two different angles (45 vs. 60 deg.) of mediolateral oblique view were compared according to radiation dose and efficacy of breast compression. Patients and methods: In 52 women, additional 60 deg. oblique films were done after craniocaudal and mediolateral oblique 45 deg.-films, with the same kVp and positioning technique. Breast thickness, time-current products (mA s) and absorbed doses were compared between 45 deg. - and 60 deg.-films. Subgroups of women with large, small, prominent and pendulous breasts were analyzed separately, following the same methodology as for the whole group. Results: mA s were 11.5% lower and compression 7% better with an angle of 60 deg. than with 45 deg. In the subgroup of women with small breasts, mA s values were 13% lower and compression 9% better with 60 deg. than with 45 deg., while in the subgroup with large breasts, mA s were 9% lower and compression 5% better. In the subgroup of patients with pendulous breasts, mA s values were 12% lower and compression 10% better with 60 deg. than with 45 deg., while in the subgroup with prominent breasts, mA s values were 4% lower and compression 3% better. Absorbed glandular dose was estimated to be approximately 20% lower when an oblique mammogram was done with 60 deg. instead

  17. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis

    OpenAIRE

    Rongyan Fan; Yuanjun Li; Changfu Li; Yansheng Zhang

    2015-01-01

    The medicinal plant Xanthium strumarium L. (X. strumarium) is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs) are a class of 21-24 nucleotide (nt) non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined w...

  18. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis.

    Directory of Open Access Journals (Sweden)

    Rongyan Fan

    Full Text Available The medicinal plant Xanthium strumarium L. (X. strumarium is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs are a class of 21-24 nucleotide (nt non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined with target gene prediction, was performed to discover novel and conserved miRNAs with potential roles in regulating terpenoid biosynthesis in X. strumarium glandular trichomes. Two small RNA libraries from leaves and glandular trichomes of X. strumarium were established. In total, 1,185 conserved miRNAs and 37 novel miRNAs were identified, with 494 conserved miRNAs and 18 novel miRNAs being differentially expressed between the two tissue sources. Based on the X. strumarium transcriptome data that we recently constructed, 3,307 annotated mRNA transcripts were identified as putative targets of the differentially expressed miRNAs. KEGG (Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that some of the differentially expressed miRNAs, including miR6435, miR5021 and miR1134, might be involved in terpenoid biosynthesis in the X. strumarium glandular trichomes. This study provides the first comprehensive analysis of miRNAs in X. strumarium, which forms the basis for further understanding of miRNA-based regulation on terpenoid biosynthesis.

  19. Differential microRNA Analysis of Glandular Trichomes and Young Leaves in Xanthium strumarium L. Reveals Their Putative Roles in Regulating Terpenoid Biosynthesis.

    Science.gov (United States)

    Fan, Rongyan; Li, Yuanjun; Li, Changfu; Zhang, Yansheng

    2015-01-01

    The medicinal plant Xanthium strumarium L. (X. strumarium) is covered with glandular trichomes, which are the sites for synthesizing pharmacologically active terpenoids such as xanthatin. MicroRNAs (miRNAs) are a class of 21-24 nucleotide (nt) non-coding RNAs, most of which are identified as regulators of plant growth development. Identification of miRNAs involved in the biosynthesis of plant secondary metabolites remains limited. In this study, high-throughput Illumina sequencing, combined with target gene prediction, was performed to discover novel and conserved miRNAs with potential roles in regulating terpenoid biosynthesis in X. strumarium glandular trichomes. Two small RNA libraries from leaves and glandular trichomes of X. strumarium were established. In total, 1,185 conserved miRNAs and 37 novel miRNAs were identified, with 494 conserved miRNAs and 18 novel miRNAs being differentially expressed between the two tissue sources. Based on the X. strumarium transcriptome data that we recently constructed, 3,307 annotated mRNA transcripts were identified as putative targets of the differentially expressed miRNAs. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis suggested that some of the differentially expressed miRNAs, including miR6435, miR5021 and miR1134, might be involved in terpenoid biosynthesis in the X. strumarium glandular trichomes. This study provides the first comprehensive analysis of miRNAs in X. strumarium, which forms the basis for further understanding of miRNA-based regulation on terpenoid biosynthesis. PMID:26406988

  20. The effects of gantry tilt on breast dose and image noise in cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Michael E.; Gandhi, Diksha; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States); Foley, W. Dennis [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)

    2013-12-15

    Purpose: This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans.Methods: Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0°–30°, in 5° increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images.Results: Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30° gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%–30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%–50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles.Conclusions: Tilting the

  1. Factors necessary to produce basoapical polarity in human glandular epithelium formed in conventional and high-throughput three-dimensional culture: example of the breast epithelium

    Directory of Open Access Journals (Sweden)

    Sturgis Jennifer

    2009-11-01

    Full Text Available Abstract Background Basoapical polarity in epithelia is critical for proper tissue function, and control of proliferation and survival. Cell culture models that recapitulate epithelial tissue architecture are invaluable to unravel developmental and disease mechanisms. Although factors important for the establishment of basal polarity have been identified, requirements for the formation of apical polarity in three-dimensional tissue structures have not been thoroughly investigated. Results We demonstrate that the human mammary epithelial cell line-3522 S1, provides a resilient model for studying the formation of basoapical polarity in glandular structures. Testing three-dimensional culture systems that differ in composition and origin of substrata reveals that apical polarity is more sensitive to culture conditions than basal polarity. Using a new high-throughput culture method that produces basoapical polarity in glandular structures without a gel coat, we show that basal polarity-mediated signaling and collagen IV are both necessary for the development of apical polarity. Conclusion These results provide new insights into the role of the basement membrane, and especially collagen IV, in the development of the apical pole, a critical element of the architecture of glandular epithelia. Also, the high-throughput culture method developed in this study should open new avenues for high-content screening of agents that act on mammary tissue homeostasis and thus, on architectural changes involved in cancer development.

  2. Methylerythritol and mevalonate pathway contributions to biosynthesis of mono-, sesqui-, and diterpenes in glandular trichomes and leaves of Stevia rebaudiana Bertoni.

    Science.gov (United States)

    Wölwer-Rieck, Ursula; May, Bianca; Lankes, Christa; Wüst, Matthias

    2014-03-19

    The biosynthesis of the diterpenoid steviol glycosides rebaudioside A and stevioside in nonrooted cuttings of Stevia rebaudiana was investigated by feeding experiments using the labeled key precursors [5,5-(2)H2]-mevalonic acid lactone (d2-MVL) and [5,5-(2)H2]-1-deoxy-d-xylulose (d2-DOX). Labeled glycosides were extracted from the leaves and stems and were directly analyzed by LC-(-ESI)-MS/MS and by GC-MS after hydrolysis and derivatization of the resulting isosteviol to the corresponding TMS-ester. Additionally, the incorporation of the proffered d2-MVL and d2-DOX into volatile monoterpenes, sesquiterpenes, and diterpenes in glandular trichomes on leaves and stems was investigated by headspace-solid phase microextraction-GC-MS (HS-SPME-GC-MS). Incorporation of the labeled precursors indicated that diterpenes in leaves and monoterpenes and diterpenes in glandular trichomes are predominately biosynthesized via the methylerythritol phosphate (MEP) pathway, whereas both the MEP and mevalonate (MVA) pathways contribute to the biosynthesis of sesquiterpenes at equal rates in glandular trichomes. These findings give evidence for a transport of MEP pathway derived farnesyl diphosphate precursors from plastids to the cytosol. Contrarily, the transport of MVA pathway derived geranyl diphosphate and geranylgeranyl diphosphate precursors from the cytosol to the plastid is limited.

  3. Comparative genetics of host response to N-methyl 1-N'-nitro-N-nitrosoguanidine. I. A lack of tumor production in the glandular stomach of Swiss mouse.

    Science.gov (United States)

    Kodama, M; Kodama, T; Fukami, H; Ogiu, T; Kodama, M

    1992-01-01

    The present study investigated the effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) drink and 3 maintenance diets on both the survival and the glandular stomach morphology in a total of 480 Swiss/ICR mice. The MNNG conditioning was practised in one half of the mice for the first 8 months. The maintenance of mice on the standard (MF) diet, the rice-rich (R) diet or the rice- and salt-rich (RS) diet was continued for 12 months. The results obtained are as follows: 1) Many mice in the MNNG-conditioned groups experienced fatal bleeding into the small intestine before the termination of the feeding experiment. There was no sign of tumor formation in their digestive canals. The bleeding deaths took place more often in the MF- and RS- diet groups than in the R-diet groups, and started to appear earlier in males than in females within the MF-diet groups. 2) The tendency to gastric atophy, as assessed in terms of the wet weight of mouse glandular stomach as well as the quantitation of histological changes of the same organ in the one-year survivors, progressed in the order of the MF-diet groups, the R-diet groups and the RS-diet groups. 3) The effect of MNNG drink on the mouse glandular stomach morphology was bidirectional: it increased the incidence of advanced atrophy (and/or decreased the incidence of advanced hyperplasia) in the MF- and R-diet groups, and rather reduced the atrophy-oriented effect of the diet on stomach morphology in the RS-diet groups. 4) The above-mentioned effects of 3 maintenance diets and MNNG drink were more prominent in males than in females. 5) No neoplastic change was detected in the glandular stomachs of the one-year survivors with and without MNNG conditioning. 6) Evidence was presented to indicate that MNNG behaved as a quasi-antiandrogen in inducing the morphological changes of mouse glandular stomach.

  4. Correlation study of effect of additional filter on radiation dose and image quality in digital mammography

    International Nuclear Information System (INIS)

    Objective: To explore the effect of different additional filters on radiation dose and image quality in digital mammography. Methods: Hologic company's Selenia digital mammography machine and the post-processing workstations and 5 M high resolution medical monitor were used in this study. Mammography phantoms with the thickness from 1.6 cm to 8.6 cm were used to simulate human breast tissue. The same exposure conditions, pressure, compression thickness, the anode were employed with the additional filters of Mo and Rh under the automatic and manual exposure mode. The image kV, mAs, pressure, filter, average glandular dose (AGD), entrance surface dose (ESD), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image score according to ACR criteria were recorded for the two additional filters. Paired sample t test was performed to compare the indices of Mo and Rh groups by using SPSS 17.0. Results: AGD and ESD of Rh and Mo group were both higher with the increase of the thickness of all the phantoms. AGD, ESD and their increased value of Rh filter(1.484 ± 1.041, 7.969 ± 7.633, 0.423 ± 0.190 and 3.057 ± 2.139) were lower than those of Mo filter (1.915 ± 1.301, 12.516 ± 11.632, 0.539 ±0.246 and 4.731 ± 3.294), in all the phantoms with different thickness (t values were 4.614, 3.209, 3.396 and 3.605, P<0.05). SNR, CNR, and image score of Rh and Mo group both decreased with the increase of the thickness of all the phantoms. There were no statistical difference (P>0.05). Conclusions: Compared with Mo filter, Rh filter could reduce the radiation dose, and this advantage is more obvious in the thicker phantom when the same image quality is required. (authors)

  5. Comparative study of patient doses calculated with two methods for breast digital tomosynthesis; Estudio de los valores de dosis a pacientes en examenes de tomosintesis de mama estimados con dos metodos distintos

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, M.; Chevalier, M.; Calzado, A.; Garayo, J.; Valverde, J.

    2015-07-01

    In this study, the average glandular doses (DG) delivered in breast tomosynthesis examinations were estimated over a sample of 150 patients using two different methods. In method 1, the conversion factors air-kerma to DG used were those tabulated by Dance et al. and in method 2 were the ones from Feng et al. The protocol for the examination followed in the unit of this study consists in two views per breast, each view composed by a 2D acquisition and a tomosynthesis scan (3D). The resulting DG values from both methods present statistically significant differences (p=0.02) for the 2D modality and were similar for the 3D scan (p=0.22). The estimated median value of DG for the most frequent breasts (thicknesses between 50 and 60 mm) delivered in a single 3D acquisition is 1.7 mGy (36% and 17% higher than the value for the 2D mode estimated with each method) which lies far below the tolerances established by the Spanish Protocol Quality Control in Radiodiagnostic (2011). The total DG for a tomosynthesis examination (6.0 mGy) is a factor 2.4 higher than the dose delivered in a 2D examination with two views (method 1). (Author)

  6. Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias: Results from a European multinational epidemiological study.

    Science.gov (United States)

    Holl, Katsiaryna; Nowakowski, Andrzej M; Powell, Ned; McCluggage, W Glenn; Pirog, Edyta C; Collas De Souza, Sabrina; Tjalma, Wiebren A; Rosenlund, Mats; Fiander, Alison; Castro Sánchez, Maria; Damaskou, Vasileia; Joura, Elmar A; Kirschner, Benny; Koiss, Robert; O'Leary, John; Quint, Wim; Reich, Olaf; Torné, Aureli; Wells, Michael; Rob, Lukas; Kolomiets, Larisa; Molijn, Anco; Savicheva, Alevtina; Shipitsyna, Elena; Rosillon, Dominique; Jenkins, David

    2015-12-15

    Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type-distribution in CGN vary, providing uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type-distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461) from 17 European countries, using centralised pathology review and sensitive HPV testing. The highest HPV-positivity rates were observed in AIS (93.9%), ASC (85.6%), and usual-type ADC (90.4%), with much lower rates in rarer ADC subtypes (clear-cell: 27.6%; serous: 30.4%; endometrioid: 12.9%; gastric-type: 0%). The most common HPV types were restricted to HPV16/18/45, accounting for 98.3% of all HPV-positive ADC. There were variations in HPV prevalence and ADC type-distribution by country. Age at diagnosis differed by ADC subtype, with usual-type diagnosed in younger women (median: 43 years) compared to rarer subtypes (medians between 57 and 66 years). Moreover, HPV-positive ADC cases were younger than HPV-negative ADC. The six years difference in median age for women with AIS compared to those with usual-type ADC suggests that cytological screening for AIS may be suboptimal. Since the great majority of CGN are HPV16/18/45-positive, the incorporation of prophylactic vaccination and HPV testing in cervical cancer screening are important prevention strategies. Our results suggest that special attention should be given to certain rarer ADC subtypes as most appear to be unrelated to HPV. PMID:26096203

  7. Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

    Energy Technology Data Exchange (ETDEWEB)

    Ciraj-Bjelac, Olivera, E-mail: ociraj@vinca.rs [Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Avramova-Cholakova, Simona, E-mail: s_avramova@mail.bg [National Centre of Radiobiology and Radiation Protection (NCRRP), Ministry of Health, Sofia (Bulgaria); Beganovic, Adnan, E-mail: adnanbeg@gmail.com [University of Sarajevo, Institute of Radiology, Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegovina); Economides, Sotirios, E-mail: adnanbeg@gmail.com [Ministry of Development, Greek Atomic Energy Commission, Athens (Greece); Faj, Dario, E-mail: dariofaj@mefos.hr [University Hospital Osijek, Osijek (Croatia); Gershan, Vesna, E-mail: vgersan@gmail.com [National Commission on Radiation Protection, Institute of Radiology, Skopje, The Former Yugoslav Republic of Macedonia (Macedonia, The Former Yugoslav Republic of); Grupetta, Edward, E-mail: edward.gruppetta@gov.mt [St. Luke' s Hospital, Diagnostic Radiology Unit, Guardamangia (Malta); Kharita, M.H., E-mail: mhkharita@aec.org.sy [Atomic Energy Commission of Syria (AECS), Department of Protection and Safety, Radiation and Nuclear Regulatory Office, Damascus (Syrian Arab Republic); Milakovic, Milomir, E-mail: mmilomir@teol.net [Ministry of Health of the Republic of Srpska, Public Health Institute of Republic of Srpska, Banja Luka, Bosnia and Herzegovina (Bosnia and Herzegovina); Milu, Constantin, E-mail: milu.constantin@yahoo.com [Institute of Public Health, SSDL, Bucharest (Romania); Muhogora, Wilbroad E., E-mail: wmuhogora@yahoo.com [Tanzania Atomic Energy Commission, Arusha, Tanzania (Tanzania, United Republic of); Muthuvelu, Pirunthavany, E-mail: mpvany@gmail.com [Ministry of Health, Radiation Health Safety Branch, Putra Jaya (Malaysia); Oola, Samuel, E-mail: ooladavidson@yahoo.com [Mulago Hospital, Department of Radiology, Kampala (Uganda); Setayeshi, Saeid, E-mail: setayesh@aut.ac.ir [Ministry of Health, Treatment, and Medical Training, Tehran (Iran, Islamic Republic of); and others

    2012-09-15

    Purpose: The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. Materials and methods: This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. Results: The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59–3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. Conclusions: Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography.

  8. Dose and dose rate monitor

    International Nuclear Information System (INIS)

    The methods are discussea of measuring dose rate or dose using a scintillation counte. A plastic scintillator based on polystyrene with PBD and POPOP activators and coated with ZnS(Ag) was chosen for the projected monitor. The scintillators were cylindrical and spherical in shape and of different sizes; black polypropylene tubes were chosen as the best case for the probs. For the counter with different plastic scintillators, the statistical error 2σ for natural background was determined. For determining the suitable thickness of the ZnS(Ag) layer the energy dependence of the counter was measured. Radioisotopes 137Cs, 241Am and 109Cd were chosen as radiation sources. The best suited ZnS(Ag) thickness was found to be 0.5 μm. Experiments were carried out to determine the directional dependence of the detector response and the signal to noise ratio. The temperature dependence of the detector response and its compensation were studied, as were the time stability and fatigue manifestations of the photomultiplier. The design of a laboratory prototype of a dose rate and dose monitor is described. Block diagrams are given of the various functional parts of the instrument. The designed instrument is easiiy portable, battery powered, measures dose rates from natural background in the range of five orders, i.e., 10-2 to 103 nGy/s, and allows to determine a dose of up to 10 mGy. Accouracy of measurement in the energy range of 50 keV to 1 MeV is better than +-20%. (E.S.)

  9. Morphology and Histochemistry of the Glandular Trichomes of Isodon rubescens (Hemsley) H.Hara (Lamiaceae)%冬凌草腺毛的形态学及组织化学研究

    Institute of Scientific and Technical Information of China (English)

    刘孟奇; 杨世勇; 李寒冰

    2011-01-01

    The morphology and distribution of leaf trichomes of Isodon rubescens were studied using light microscopy. (l)Three morphologically distinct types of trichomes were observed on I. Rubescens leaf surfaces: non-glandular, peltate and capitate glandular. The glandular and non-glandular trichomes were present on both the adaxial and abaxial surfaces. Peltate and capitate glandular trichomes comprised one basal cell,one or two stalk cells and one head. The head of mature peltate glandular trichomes generally consisted of four secretory cells while that of capitate glandular hairs was composed of two cells. (2)Histochemical results indicate existence of flavnoids in both peltate and capitate glandular trichomes. In addition, terpe-noids,including monoterpenes, sesquiterpenes etc. , exist in peltate glandular trichomes. Peltate glandular trichomes are probably only site of oridonin accumulation,however,this need direct proof to clarify. High density of peltate trichomes might be considered as an important selection character for the screening of I. Rubescens with rich content of oridonin.%利用光学显微镜对药用植物冬凌草地上部分腺毛的形态、分布和组织化学进行了研究.结果表明:(1)冬凌草的叶表皮有3种形态显著不同的毛,即非腺毛、盾状腺毛和头状腺毛;盾状腺毛和头状腺毛均具1个基细胞、1个柄细胞和头部;成熟的盾状腺毛的头部一般由4个分泌细胞组成,而头状腺毛头部由2个分泌细胞组成.(2)组织化学鉴定结果显示:2种腺毛中均含有黄酮类成分,盾状腺毛中还含有单萜、倍半萜等萜类成分;冬凌草甲素可能只存在于盾状腺毛中,但需要更直接的证据证明.研究认为,高密度的盾状腺毛可以作为筛选冬凌草高甲素含量品种的一项重要依据.

  10. Establishment Of Dose Correlation During Dose Mapping On Medical Devices

    International Nuclear Information System (INIS)

    This paper explains the work done during product dose mapping in order to get the correlation between doses at MINTec-Sinagama plant. Product used was medical devices in aluminium tubes packaged in cardboard kegs packaging with average weight of 12 kg per carton. 12 cartons were loaded in every one tote to give 0.2 g/ cm3 of density. Ceric cerous dosimeters were placed at specific locations as indicated in SP14: Product Dose Mapping, QMS of MINTec-Sinagama around three planes. Three processes were made at different days as a three replicates to show the reproducibility of measurements. (author)

  11. Digital Breast Tomosynthesis: Comparison of Different Methods to Calculate Patient Doses

    International Nuclear Information System (INIS)

    Different methods have been proposed in the literature to calculate the dose to the patient's breast in 3-D mammography. The methods described by Dance et al. and Sechopoulos et al. have been compared in this study using the two tomosynthesis systems available in the authors' hospitals (Siemens and Hologic). There is a small but significant difference of 23% for the first X ray system and 13% for the second system between dose calculations performed with Dance's method and Sechopoulos' method. These differences are mainly due to the fact that the two sets of authors used different breast models for their Monte Carlo calculations. For each system, the calculated breast doses were compared with the dose values indicated on the system console. Good agreement was found when the method of Dance et al. was used for a breast glandularity based on the patient age. For the Siemens system, the calculated doses were 5% lower than the indicated dose and for the Hologic system, the calculated doses were 12% higher. Finally, the 3-D dose values were compared with the doses found in a large 2-D dosimetry study. The dose values for tomosynthesis on the Siemens system were almost double the doses in one view 2-D digital mammography. For a typical breast of thickness 45 mm, the dose of one 2-D view was 0.83 mGy and for one 3-D view 1.79 mGy. (author)

  12. Dose variation during solar minimum

    Energy Technology Data Exchange (ETDEWEB)

    Gussenhoven, M.S.; Mullen, E.G.; Brautigam, D.H. (Phillips Lab., Geophysics Directorate, Hanscom Air Force Base, MA (US)); Holeman, E. (Boston Univ., MA (United States). Dept. of Physics)

    1991-12-01

    In this paper, the authors use direct measurement of dose to show the variation in inner and outer radiation belt populations at low altitude from 1984 to 1987. This period includes the recent solar minimum that occurred in September 1986. The dose is measured behind four thicknesses of aluminum shielding and for two thresholds of energy deposition, designated HILET and LOLET. The authors calculate an average dose per day for each month of satellite operation. The authors find that the average proton (HILET) dose per day (obtained primarily in the inner belt) increased systematically from 1984 to 1987, and has a high anticorrelation with sunspot number when offset by 13 months. The average LOLET dose per day behind the thinnest shielding is produced almost entirely by outer zone electrons and varies greatly over the period of interest. If any trend can be discerned over the 4 year period it is a decreasing one. For shielding of 1.55 gm/cm{sup 2} (227 mil) Al or more, the LOLET dose is complicated by contributions from {gt} 100 MeV protons and bremsstrahlung.

  13. 7 CFR 1209.12 - On average.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false On average. 1209.12 Section 1209.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS....12 On average. On average means a rolling average of production or imports during the last two...

  14. Distinct expression pattern and post-transcriptional regulation of cell cycle genes in the glandular epithelia of avian ovarian carcinomas.

    Directory of Open Access Journals (Sweden)

    Jin-Young Lee

    Full Text Available The cell cycle system is controlled in a timely manner by three groups of cyclins, cyclin dependent kinases and cyclin dependent kinase inhibitors. Abnormal alterations of cell cycle regulatory mechanisms are a common feature of many diseases including numerous tumor types such as ovarian cancer. Although a variety of cell cycle regulatory genes are well known in mammalian species including human and mice, they are not well studied in avian species, especially in laying hens which are recognized as an excellent animal model for research relevant to human ovarian carcinogenesis. Therefore, in the present study, we focused on comparative expression and regulation of expression of candidate genes which might be involved in the cell cycle program in surface epithelial ovarian cancer in laying hens. Our current results indicate that expression levels of cell cycle gene transcripts are greater in cancerous as compared to normal ovaries. In particular, cyclin A2 (CCNA2, CCND1, CCND2, CCND3, CCNE2, cyclin dependent kinase 1 (CDK1, CDK3, CDK5, cyclin dependent kinases inhibitor 1A (CDKN1A and CDKN1B were upregulated predominantly in the glandular epithelia of cancerous ovaries from laying hens. Further, several microRNAs (miRs, specifically miR-1798, miR-1699, miR-223 and miR-1744 were discovered to influence expression of CCND1, CCNE2, CDK1, and CDK3 mRNAs, respectively, via their 3'-UTR which suggests that post-transcriptional regulation of gene expression influences their expression in laying hens. Moreover, miR-1626 influenced CDKN1A expression and miR-222, miR-1787 and miR-1812 regulated CDKN1B expression via their 3'-UTR regions. Collectively, results of the present study demonstrate increased expression of cell cycle-related genes in cancerous ovaries of laying hens and indicate that expression of these genes is post-transcriptionally regulated by specific microRNAs.

  15. Doses from radiation exposure

    CERN Document Server

    Menzel, H G

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection's (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP's 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effecti...

  16. Evaluation of bismuth shielding effectiveness in reducing breast absorbed dose during thoracic CT scan

    International Nuclear Information System (INIS)

    Computed Tomography (CT) is an essential method for tracking neoplasia and efficiently diagnosing a wide variety of thoracic diseases. CT is generally considered the most accurate choice for lung examination. Due to the growing use of CT, breast and other superficial and radiosensitive organs are unnecessarily irradiated during radiological procedures, thus requiring the development of strategies appropriate to optimize and, if possible, to reduce the radiation dose. The use of bismuth shielding to reduce radiation dose absorbed by breast during thoracic CT examinations has been the subject of many studies recently published by Brazilian and foreign authors of various fields. The purpose of this paper is both to accurately determine the glandular dose when breast is exposed to radiation and to assess the reduction in absorbed dose during thoracic CT examinations, using a set of Thermoluminescent Dosimeters, an anthropomorphic phantom and bismuth shielding. (Author)

  17. Evaluation of bismuth shielding effectiveness in reducing breast absorbed dose during thoracic CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, T. C.; Mourao, A. P.; Santana, P. C.; Silva, T. A. [Federal University of Minas Gerais, Program of Nuclear Science and Techniques, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Computed Tomography (CT) is an essential method for tracking neoplasia and efficiently diagnosing a wide variety of thoracic diseases. CT is generally considered the most accurate choice for lung examination. Due to the growing use of CT, breast and other superficial and radiosensitive organs are unnecessarily irradiated during radiological procedures, thus requiring the development of strategies appropriate to optimize and, if possible, to reduce the radiation dose. The use of bismuth shielding to reduce radiation dose absorbed by breast during thoracic CT examinations has been the subject of many studies recently published by Brazilian and foreign authors of various fields. The purpose of this paper is both to accurately determine the glandular dose when breast is exposed to radiation and to assess the reduction in absorbed dose during thoracic CT examinations, using a set of Thermoluminescent Dosimeters, an anthropomorphic phantom and bismuth shielding. (Author)

  18. Dose absorbed in adults and children thyroid due to the I{sup 123} using the dosimetry MIRD and Marinelli; Dosis absorbida en tiroides de adultos y ninos debido al I{sup 123} utilizando las dosimetrias MIRD y Marinelli

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Castillo, C.; Cabrera, C.; Sarachaga, R.; Castaneda, J. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru); Diaz, E., E-mail: marvva@hotmail.com [Universidade Federal do Rio Grande do Sul, Av. Paulo Gamma 110, Bairro Farropilhas, Porto Alegre, RS 90040-060 (Brazil)

    2014-08-15

    Using the dosimetry MIRD, and representation Cristy-Eckerman in the thyroid gland and organs of their bio-kinetics when I{sup 123} (Iodine) is used, the study demonstrates that the absorbed dose by the gland of an adult, children, and newly born, is their auto-dose, independent of the compartments number of their bio-kinetics. The dosimetric contributions of the organs of their bio-kinetics are insignificant. Their results are not significantly different to those obtained by the formalism MARINELLI (auto-dose) when it uses a sphere like glandular representation. In consequence, the kinetic model corresponding to the glandular representation decreases to a compartment, where the gland can also be represented like a sphere. (Author)

  19. Antibodies against Escherichia coli O24 and O56 O-Specific Polysaccharides Recognize Epitopes in Human Glandular Epithelium and Nervous Tissue.

    Directory of Open Access Journals (Sweden)

    Agnieszka Korzeniowska-Kowal

    Full Text Available Lipopolysaccharide (LPS, the major component of the outer membrane of Gram-negative bacteria, contains the O-polysaccharide, which is important to classify bacteria into different O-serological types within species. The O-polysaccharides of serotypes O24 and O56 of E. coli contain sialic acid in their structures, already established in our previous studies. Here, we report the isolation of specific antibodies with affinity chromatography using immobilized lipopolysaccharides. Next, we evaluated the reactivity of anti-O24 and anti-O56 antibody on human tissues histologically. The study was conducted under the assumption that the sialic acid based molecular identity of bacterial and tissue structures provides not only an understanding of the mimicry-based bacterial pathogenicity. Cross-reacting antibodies could be used to recognize specific human tissues depending on their histogenesis and differentiation, which might be useful for diagnostic purposes. The results indicate that various human tissues are recognized by anti-O24 and anti-O56 antibodies. Interestingly, only a single specific reactivity could be found in the anti-O56 antibody preparation. Several tissues studied were not reactive with either antibody, thus proving that the presence of cross-reactive antigens was tissue specific. In general, O56 antibody performed better than O24 in staining epithelial and nervous tissues. Positive staining was observed for both normal (ganglia and tumor tissue (ganglioneuroma. Epithelial tissue showed positive staining, but an epitope recognized by O56 antibody should be considered as a marker of glandular epithelium. The reason is that malignant glandular tumor and its metastasis are stained, and also epithelium of renal tubules and glandular structures of the thyroid gland are stained. Stratified epithelium such as that of skin is definitely not stained. Therefore, the most relevant observation is that the epitope recognized by anti-O56 antibodies is

  20. Averages of Values of L-Series

    OpenAIRE

    Alkan, Emre; Ono, Ken

    2013-01-01

    We obtain an exact formula for the average of values of L-series over two independent odd characters. The average of any positive moment of values at s = 1 is then expressed in terms of finite cotangent sums subject to congruence conditions. As consequences, bounds on such cotangent sums, limit points for the average of first moment of L-series at s = 1 and the average size of positive moments of character sums related to the class number are deduced.

  1. Spectral averaging techniques for Jacobi matrices

    CERN Document Server

    del Rio, Rafael; Schulz-Baldes, Hermann

    2008-01-01

    Spectral averaging techniques for one-dimensional discrete Schroedinger operators are revisited and extended. In particular, simultaneous averaging over several parameters is discussed. Special focus is put on proving lower bounds on the density of the averaged spectral measures. These Wegner type estimates are used to analyze stability properties for the spectral types of Jacobi matrices under local perturbations.

  2. Plan averaging for multicriteria navigation of sliding window IMRT and VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Craft, David, E-mail: dcraft@partners.org; Papp, Dávid; Unkelbach, Jan [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)

    2014-02-15

    Purpose: To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. Methods: The authors show that by taking an appropriately defined average of leaf trajectories of sliding window plans, the authors obtain a sliding window plan whose fluence map is the exact average of the fluence maps corresponding to the initial plans. In the case of static-beam IMRT, this also implies that the dose distribution of the averaged plan is the exact dosimetric average of the initial plans. In VMAT delivery, the dose distribution of the averaged plan is a close approximation of the dosimetric average of the initial plans. Results: The authors demonstrate the method on three Pareto optimal VMAT plans created for a demanding paraspinal case, where the tumor surrounds the spinal cord. The results show that the leaf averaged plans yield dose distributions that approximate the dosimetric averages of the precomputed Pareto optimal plans well. Conclusions: The proposed method enables the navigation of deliverable Pareto optimal plans directly, i.e., interactive multicriteria exploration of deliverable sliding window IMRT and VMAT plans, eliminating the need for a sequencing step after navigation and hence the dose degradation that is caused by such a sequencing step.

  3. A Geranylfarnesyl Diphosphate Synthase Provides the Precursor for Sesterterpenoid (C25) Formation in the Glandular Trichomes of the Mint Species Leucosceptrum canum.

    Science.gov (United States)

    Liu, Yan; Luo, Shi-Hong; Schmidt, Axel; Wang, Guo-Dong; Sun, Gui-Ling; Grant, Marcus; Kuang, Ce; Yang, Min-Jie; Jing, Shu-Xi; Li, Chun-Huan; Schneider, Bernd; Gershenzon, Jonathan; Li, Sheng-Hong

    2016-03-01

    Plant sesterterpenoids, an important class of terpenoids, are widely distributed in various plants, including food crops. However, little is known about their biosynthesis. Here, we cloned and functionally characterized a plant geranylfarnesyl diphosphate synthase (Lc-GFDPS), the enzyme producing the C25 prenyl diphosphate precursor to all sesterterpenoids, from the glandular trichomes of the woody plant Leucosceptrum canum. GFDPS catalyzed the formation of GFDP after expression in Escherichia coli. Overexpressing GFDPS in Arabidopsis thaliana also gave an extract catalyzing GFDP formation. GFDPS was strongly expressed in glandular trichomes, and its transcript profile was completely in accordance with the sesterterpenoid accumulation pattern. GFDPS is localized to the plastids, and inhibitor studies indicated its use of isoprenyl diphosphate substrates supplied by the 2-C-methyl-D-erythritol 4-phosphate pathway. Application of a jasmonate defense hormone induced GFDPS transcript and sesterterpenoid accumulation, while reducing feeding and growth of the generalist insect Spodoptera exigua, suggesting that these C25 terpenoids play a defensive role. Phylogenetic analysis suggested that GFDPS probably evolved from plant geranylgeranyl diphosphate synthase under the influence of positive selection. The isolation of GFDPS provides a model for investigating sesterterpenoid formation in other species and a tool for manipulating the formation of this group in plants and other organisms.

  4. Helicobacter pylori infection, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer and early gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Chuan Zhang; Nobutaka Yamada; Yun-Lin Wu; Min Wen; Takeshi Matsuhisa; Norio Matsukura

    2005-01-01

    AIM: To evaluate the histological features of gastric mucosa, including Helicobacter pylori infection in patients with early gastric cancer and endoscopically found superficial gastritis, gastric erosion, erosive gastritis,gastric ulcer.METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of all the patients.Giemsa staining, improved toluidine-blue staining, and H pylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of gastric mucosa inflammation, gastric glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System.RESULTS: The overall prevalence of H pylori infection in superficial gastritis was 28.7%, in erosive gastritis 57.7%,in gastric erosion 63.3%, in gastric ulcer 80.8%, in early gastric cancer 52.4%. There was significant difference (P<0.05), except for the difference between early gastric cancer and erosive gastritis. H pylori infection rate in antrum, corpus, angulus of patients with superficial gastritis was 25.9%, 26.2%, 25.2%, respectively; in patients with erosive gastritis 46.9%, 53.5%, 49.0%,respectively; in patients with gastric erosion 52.4%, 61.5%,52.4%, respectively; in patients with gastric ulcer 52.4%,61.5%, 52.4%, respectively; in patients with early gastric cancer 35.0%, 50.7%, 34.6%, respectively. No significant difference was found among the different site biopsies in superficial gastritis, but in the other diseases the detected rates were higher in corpus biopsy (P<0.05). The grades of mononuclear cell infiltration and polymorphonuclear cell infiltration, in early gastric cancer patients, were significantly higher than that in superficial gastritis patients, lower than that in gastric erosion and gastric ulcer patients (P<0.01);however, there was no significant difference compared with erosive gastritis. The grades

  5. A Geranylfarnesyl Diphosphate Synthase Provides the Precursor for Sesterterpenoid (C25) Formation in the Glandular Trichomes of the Mint Species Leucosceptrum canum.

    Science.gov (United States)

    Liu, Yan; Luo, Shi-Hong; Schmidt, Axel; Wang, Guo-Dong; Sun, Gui-Ling; Grant, Marcus; Kuang, Ce; Yang, Min-Jie; Jing, Shu-Xi; Li, Chun-Huan; Schneider, Bernd; Gershenzon, Jonathan; Li, Sheng-Hong

    2016-03-01

    Plant sesterterpenoids, an important class of terpenoids, are widely distributed in various plants, including food crops. However, little is known about their biosynthesis. Here, we cloned and functionally characterized a plant geranylfarnesyl diphosphate synthase (Lc-GFDPS), the enzyme producing the C25 prenyl diphosphate precursor to all sesterterpenoids, from the glandular trichomes of the woody plant Leucosceptrum canum. GFDPS catalyzed the formation of GFDP after expression in Escherichia coli. Overexpressing GFDPS in Arabidopsis thaliana also gave an extract catalyzing GFDP formation. GFDPS was strongly expressed in glandular trichomes, and its transcript profile was completely in accordance with the sesterterpenoid accumulation pattern. GFDPS is localized to the plastids, and inhibitor studies indicated its use of isoprenyl diphosphate substrates supplied by the 2-C-methyl-D-erythritol 4-phosphate pathway. Application of a jasmonate defense hormone induced GFDPS transcript and sesterterpenoid accumulation, while reducing feeding and growth of the generalist insect Spodoptera exigua, suggesting that these C25 terpenoids play a defensive role. Phylogenetic analysis suggested that GFDPS probably evolved from plant geranylgeranyl diphosphate synthase under the influence of positive selection. The isolation of GFDPS provides a model for investigating sesterterpenoid formation in other species and a tool for manipulating the formation of this group in plants and other organisms. PMID:26941091

  6. Thyroid absorbed dose using TLDs during mammography

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez A, M.; Melendez L, M. [IPN, Centro de Investigacion y de Estudios Avanzados, Av. IPN 2508, Col. San Pedro Zacatenco, 07360 Mexico D. F. (Mexico); Davila M, P., E-mail: biomedica.sst@gmail.com [UNEME-DEDICAM de Ciudad Victoria, Circuito Medico s/n, 87087 Ciudad Victoria, Tamaulipas (Mexico)

    2015-10-15

    Full text: In this study, the mean glandular dose (MGD) and the thyroid dose (D Thy) were measured in 200 women screened with mammography in Cranio caudal (Cc) and mediolateral oblique projections. All mammograms were performed with Giotto-Ims (6000-14-M2 Model) equipment, which was verified to meet the criteria of quality of NOM-229-Ssa-2002. During audits performance and HVL, for each anode filter combinations was measured with the camera Radcal mammography equipment 10 X 6-6M (HVL = 0.26 mm Al). D Thy measurements were performed with TLD dosimeters (LiF:Mn) , that were read with the Harshaw 3500 TLD reader. The MGD, was obtained according to the UK and European protocols for mammographic dosimetry using a plane parallel chamber (Standard Imaging, Model A-600) calibrated by a radiation beam UW-23-Mo (= 0.279 mm Al HVL). A comparative statistical analysis was carried out with the measured MGD and D thy. The thyroid mean dose was 0.063 mGy and 0.078 mGy for Cc and mediolateral oblique respectively. There is a linear correlation between the MGD and the D Thy slightly influenced by the anode-filter combination. Using a 95% for the confidence interval in MGD (1.07 mGy), the 90% of measurements are in agreement with the established uncertainty limits. The D Thy are lower than the MGD. There is no risk for cancer induction in thyroid in women due to mammography screening. (Author)

  7. Average-cost based robust structural control

    Science.gov (United States)

    Hagood, Nesbitt W.

    1993-01-01

    A method is presented for the synthesis of robust controllers for linear time invariant structural systems with parameterized uncertainty. The method involves minimizing quantities related to the quadratic cost (H2-norm) averaged over a set of systems described by real parameters such as natural frequencies and modal residues. Bounded average cost is shown to imply stability over the set of systems. Approximations for the exact average are derived and proposed as cost functionals. The properties of these approximate average cost functionals are established. The exact average and approximate average cost functionals are used to derive dynamic controllers which can provide stability robustness. The robustness properties of these controllers are demonstrated in illustrative numerical examples and tested in a simple SISO experiment on the MIT multi-point alignment testbed.

  8. Plasminogen-independent initiation of the pro-urokinase activation cascade in vivo. Activation of pro-urokinase by glandular kallikrein (mGK-6) in plasminogen-deficient mice

    DEFF Research Database (Denmark)

    List, K; Jensen, O N; Bugge, T H;

    2000-01-01

    the cascade by activating pro-uPA. The urine from Plg -/- mice contained active two-chain uPA as well as a proteinase capable of activating exogenously added pro-uPA. The active component was purified and identified by mass spectrometry-based peptide mapping as mouse glandular kallikrein mGK-6 (true tissue...... kallikrein). The pro-uPA converting activity of the mGK-6 enzyme, as well as its ability to cleave a synthetic substrate for glandular kallikrein, was inhibited by the serine proteinase inhibitor leupeptin but not by other serine proteinase inhibitors such as aprotinin, antithrombin III, or alpha(1...

  9. MEASUREMENT AND MODELLING AVERAGE PHOTOSYNTHESIS OF MAIZE

    OpenAIRE

    ZS LÕKE

    2005-01-01

    The photosynthesis of fully developed maize was investigated in the Agrometeorological Research Station Keszthely, in 2000. We used LI-6400 type measurement equipment to locate measurement points where the intensity of photosynthesis mostly nears the average. So later we could obtain average photosynthetic activities featuring the crop, with only one measurement. To check average photosynthesis of maize we used Goudriaan’s simulation model (CMSM) as well to calculate values on cloudless sampl...

  10. WIDTHS AND AVERAGE WIDTHS OF SOBOLEV CLASSES

    Institute of Scientific and Technical Information of China (English)

    刘永平; 许贵桥

    2003-01-01

    This paper concerns the problem of the Kolmogorov n-width, the linear n-width, the Gel'fand n-width and the Bernstein n-width of Sobolev classes of the periodicmultivariate functions in the space Lp(Td) and the average Bernstein σ-width, averageKolmogorov σ-widths, the average linear σ-widths of Sobolev classes of the multivariatequantities.

  11. Patient dose in neonatal units

    International Nuclear Information System (INIS)

    Lung disease represents one of the most life-threatening conditions in prematurely born children. In the evaluation of the neonatal chest, the primary and most important diagnostic study is therefore the chest radiograph. Since prematurely born children are very sensitive to radiation, those radiographs may lead to a significant radiation detriment. Hence, knowledge of the patient dose is necessary to justify the exposures. A study to assess the patient doses was started at the neonatal intensive care unit (NICU) of the Univ. Hospital in Leuven. Between September 2004 and September 2005, prematurely born babies underwent on average 10 X-ray examinations in the NICU. In this sample, the maximum was 78 X-ray examinations. For chest radiographs, the median entrance skin dose was 34 μGy and the median dose area product was 7.1 mGy.cm2. By means of conversion coefficients, the measured values were converted to organ doses. Organ doses were calculated for three different weight classes: extremely low birth weight infants (2500 g). The doses to the lungs for a single chest radiograph for infants with extremely low birth weights, low birth weights and normal birth weights were 24, 25 and 32 μGy, respectively. (authors)

  12. NOAA Average Annual Salinity (3-Zone)

    Data.gov (United States)

    California Department of Resources — The 3-Zone Average Annual Salinity Digital Geography is a digital spatial framework developed using geographic information system (GIS) technology. These salinity...

  13. Stochastic averaging of quasi-Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    朱位秋

    1996-01-01

    A stochastic averaging method is proposed for quasi-Hamiltonian systems (Hamiltonian systems with light dampings subject to weakly stochastic excitations). Various versions of the method, depending on whether the associated Hamiltonian systems are integrable or nonintegrable, resonant or nonresonant, are discussed. It is pointed out that the standard stochastic averaging method and the stochastic averaging method of energy envelope are special cases of the stochastic averaging method of quasi-Hamiltonian systems and that the results obtained by this method for several examples prove its effectiveness.

  14. Dose rate mapping of VMAT treatments.

    Science.gov (United States)

    Podesta, Mark; Popescu, I Antoniu; Verhaegen, Frank

    2016-06-01

    Human tissues exhibit a varying response to radiation dose depending on the dose rate and fractionation scheme used. Dose rate effects have been reported for different radiations, and tissue types. The literature indicates that there is not a significant difference in response for low-LET radiation when using dose rates between 1 Gy min(-1) and 12 Gy min(-1) but lower dose rates have an observable sparing effect on tissues and a differential effect between tissues. In intensity-modulated radiotherapy such as volumetric modulated arc therapy (VMAT) the dose can be delivered with a wide range of dose rates. In this work we developed a method based on time-resolved Monte Carlo simulations to quantify the dose rate frequency distribution for clinical VMAT treatments for three cancer sites, head and neck, lung, and pelvis within both planning target volumes (PTV) and normal tissues. The results show a wide range of dose rates are used to deliver dose in VMAT and up to 75% of the PTV can have its dose delivered with dose rates  <1 Gy min(-1). Pelvic plans on average have a lower mean dose rate within the PTV than lung or head and neck plans but a comparable mean dose rate within the organs at risk. Two VMAT plans that fulfil the same dose objectives and constraints may be delivered with different dose rate distributions, particularly when comparing single arcs to multiple arc plans. It is concluded that for dynamic plans, the dose rate range used varies to a larger degree than previously assumed. The effect of the dose rate range in VMAT on clinical outcome is unknown.

  15. Dose rate mapping of VMAT treatments

    Science.gov (United States)

    Podesta, Mark; Antoniu Popescu, I.; Verhaegen, Frank

    2016-06-01

    Human tissues exhibit a varying response to radiation dose depending on the dose rate and fractionation scheme used. Dose rate effects have been reported for different radiations, and tissue types. The literature indicates that there is not a significant difference in response for low-LET radiation when using dose rates between 1 Gy min-1 and 12 Gy min-1 but lower dose rates have an observable sparing effect on tissues and a differential effect between tissues. In intensity-modulated radiotherapy such as volumetric modulated arc therapy (VMAT) the dose can be delivered with a wide range of dose rates. In this work we developed a method based on time-resolved Monte Carlo simulations to quantify the dose rate frequency distribution for clinical VMAT treatments for three cancer sites, head and neck, lung, and pelvis within both planning target volumes (PTV) and normal tissues. The results show a wide range of dose rates are used to deliver dose in VMAT and up to 75% of the PTV can have its dose delivered with dose rates  <1 Gy min-1. Pelvic plans on average have a lower mean dose rate within the PTV than lung or head and neck plans but a comparable mean dose rate within the organs at risk. Two VMAT plans that fulfil the same dose objectives and constraints may be delivered with different dose rate distributions, particularly when comparing single arcs to multiple arc plans. It is concluded that for dynamic plans, the dose rate range used varies to a larger degree than previously assumed. The effect of the dose rate range in VMAT on clinical outcome is unknown.

  16. Average Transmission Probability of a Random Stack

    Science.gov (United States)

    Lu, Yin; Miniatura, Christian; Englert, Berthold-Georg

    2010-01-01

    The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower…

  17. Average sampling theorems for shift invariant subspaces

    Institute of Scientific and Technical Information of China (English)

    孙文昌; 周性伟

    2000-01-01

    The sampling theorem is one of the most powerful results in signal analysis. In this paper, we study the average sampling on shift invariant subspaces, e.g. wavelet subspaces. We show that if a subspace satisfies certain conditions, then every function in the subspace is uniquely determined and can be reconstructed by its local averages near certain sampling points. Examples are given.

  18. Average excitation potentials of air and aluminium

    NARCIS (Netherlands)

    Bogaardt, M.; Koudijs, B.

    1951-01-01

    By means of a graphical method the average excitation potential I may be derived from experimental data. Average values for Iair and IAl have been obtained. It is shown that in representing range/energy relations by means of Bethe's well known formula, I has to be taken as a continuously changing fu

  19. New results on averaging theory and applications

    Science.gov (United States)

    Cândido, Murilo R.; Llibre, Jaume

    2016-08-01

    The usual averaging theory reduces the computation of some periodic solutions of a system of ordinary differential equations, to find the simple zeros of an associated averaged function. When one of these zeros is not simple, i.e., the Jacobian of the averaged function in it is zero, the classical averaging theory does not provide information about the periodic solution associated to a non-simple zero. Here we provide sufficient conditions in order that the averaging theory can be applied also to non-simple zeros for studying their associated periodic solutions. Additionally, we do two applications of this new result for studying the zero-Hopf bifurcation in the Lorenz system and in the Fitzhugh-Nagumo system.

  20. Short-Term Auditory Memory of Above-Average and Below-Average Grade Three Readers.

    Science.gov (United States)

    Caruk, Joan Marie

    To determine if performance on short term auditory memory tasks is influenced by reading ability or sex differences, 62 third grade reading students (16 above average boys, 16 above average girls, 16 below average boys, and 14 below average girls) were administered four memory tests--memory for consonant names, memory for words, memory for…

  1. Clarifying the Relationship between Average Excesses and Average Effects of Allele Substitutions.

    Science.gov (United States)

    Alvarez-Castro, José M; Yang, Rong-Cai

    2012-01-01

    Fisher's concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance. PMID:22509178

  2. Clarifying the relationship between average excesses and average effects of allele substitutions

    Directory of Open Access Journals (Sweden)

    Jose M eÁlvarez-Castro

    2012-03-01

    Full Text Available Fisher’s concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one-locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance.

  3. Evaluation of Doses and Image Quality in Mammography with Screen-Film, CR, and DR Detectors – Application of the ACR Phantom

    Science.gov (United States)

    Ślusarczyk-Kacprzyk, Wioletta; Skrzyński, Witold; Fabiszewska, Ewa

    2016-01-01

    Summary Background Different methods of image quality evaluation are routinely used for analogue and digital mammography systems in Poland. In the present study, image quality for several screen-film (SF), computed radiography (CR), and fully digital (DR) mammography systems was compared directly with the use of the ACR mammography accreditation phantom. Material/Methods Image quality and mean glandular doses were measured and compared for 47 mammography systems in the Mazovia Voivodeship in Poland, including 26 SF systems, 12 CR systems, and 9 DR systems. The mean glandular dose for the breast simulated by 4.5 cm of PMMA was calculated with methods described in the “European guidelines for quality assurance in breast cancer screening and diagnosis”. Visibility of the structures in the image (fibers, microcalcifications, and masses) was evaluated with the mammographic accreditation ACR phantom. Results Image quality for DR systems was significantly higher than for SF and CR systems. Several SF systems failed to pass the image quality tests because of artifacts. The doses were within acceptable limits for all of the systems, but the doses for the CR systems were significantly higher than for the SF and DR systems. Conclusions The best image quality, at a reasonably low dose, was observed for the DR systems. The CR systems are capable of obtaining the same image quality as the SF systems, but only at a significantly higher dose. The ACR phantom can be routinely used to evaluate image quality for all types of mammographic systems. PMID:27617048

  4. Small scale magnetic flux-averaged magnetohydrodynamics

    International Nuclear Information System (INIS)

    By relaxing exact magnetic flux conservation below a scale λ a system of flux-averaged magnetohydrodynamic equations are derived from Hamilton's principle with modified constraints. An energy principle can be derived from the linearized averaged system because the total system energy is conserved. This energy principle is employed to treat the resistive tearing instability and the exact growth rate is recovered when λ is identified with the resistive skin depth. A necessary and sufficient stability criteria of the tearing instability with line tying at the ends for solar coronal loops is also obtained. The method is extended to both spatial and temporal averaging in Hamilton's principle. The resulting system of equations not only allows flux reconnection but introduces irreversibility for appropriate choice of the averaging function. Except for boundary contributions which are modified by the time averaging process total energy and momentum are conserved over times much longer than the averaging time τ but not for less than τ. These modified boundary contributions correspond to the existence, also, of damped waves and shock waves in this theory. Time and space averaging is applied to electron magnetohydrodynamics and in one-dimensional geometry predicts solitons and shocks in different limits

  5. Comparative study of dose estimation in the change a conventional mammography to digital mammography; Estudio comparativo de estimacion de dosis en el cambio de un mamografo convencional a un mamografo digital

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Vazquez, R.; Otero Martinez, C.; Soto Bua, M.; Santamarina Vazquez, F.; Carril Iglesias, S.; Lobato Busto, R.; Luna Vega, V.; Mosquera Sueiro, J.; Sqanchez Garcia, M.; Pombar Camean, M.

    2011-07-01

    Mammographic studies are now one of the most demanding radiological because of its effectiveness in detecting breast cancer early. The introduction of digital mammography has been a major advance because it has overcome some of the limitations of conventional systems. Due to the nature of the radiosensitive glandular tissue becomes very important control of the dose given to patients. In the present study is to analyze the variations in dosimetry that can exist between a conventional mammography and digital mammography.

  6. Chewing-gum stimulation did not reduce the absorbed dose to salivary glands during radioiodine treatment of thyroid cancer as inferred from pre-therapy 124I PET/CT imaging

    OpenAIRE

    Jentzen, Walter; Richter, Marion; Nagarajah, James; Poeppel, Thorsten Dirk; Brandau, Wolfgang; Dawes, Colin; Bockisch, Andreas; Binse, Ina

    2014-01-01

    Background The goal of this prospective study was to estimate the absorbed (radiation) doses to salivary glands in radioiodine therapy of thyroid cancer under chewing-gum stimulation using 124I positron emission tomography (PET)/computed tomography (CT) imaging. Methods Duplex ultrasonography was conducted in three test persons for visual comparison of the glandular blood flow with three different stimulation types (no stimulation, chewing tasteless gum base, sucking on lemon slices). Ten pat...

  7. Averaged Lema\\^itre-Tolman-Bondi dynamics

    CERN Document Server

    Isidro, Eddy G Chirinos; Piattella, Oliver F; Zimdahl, Winfried

    2016-01-01

    We consider cosmological backreaction effects in Buchert's averaging formalism on the basis of an explicit solution of the Lema\\^itre-Tolman-Bondi (LTB) dynamics which is linear in the LTB curvature parameter and has an inhomogeneous bang time. The volume Hubble rate is found in terms of the volume scale factor which represents a derivation of the simplest phenomenological solution of Buchert's equations in which the fractional densities corresponding to average curvature and kinematic backreaction are explicitly determined by the parameters of the underlying LTB solution at the boundary of the averaging volume. This configuration represents an exactly solvable toy model but it does not adequately describe our "real" Universe.

  8. Average-passage flow model development

    Science.gov (United States)

    Adamczyk, John J.; Celestina, Mark L.; Beach, Tim A.; Kirtley, Kevin; Barnett, Mark

    1989-01-01

    A 3-D model was developed for simulating multistage turbomachinery flows using supercomputers. This average passage flow model described the time averaged flow field within a typical passage of a bladed wheel within a multistage configuration. To date, a number of inviscid simulations were executed to assess the resolution capabilities of the model. Recently, the viscous terms associated with the average passage model were incorporated into the inviscid computer code along with an algebraic turbulence model. A simulation of a stage-and-one-half, low speed turbine was executed. The results of this simulation, including a comparison with experimental data, is discussed.

  9. Average Shape of Transport-Limited Aggregates

    Science.gov (United States)

    Davidovitch, Benny; Choi, Jaehyuk; Bazant, Martin Z.

    2005-08-01

    We study the relation between stochastic and continuous transport-limited growth models. We derive a nonlinear integro-differential equation for the average shape of stochastic aggregates, whose mean-field approximation is the corresponding continuous equation. Focusing on the advection-diffusion-limited aggregation (ADLA) model, we show that the average shape of the stochastic growth is similar, but not identical, to the corresponding continuous dynamics. Similar results should apply to DLA, thus explaining the known discrepancies between average DLA shapes and viscous fingers in a channel geometry.

  10. Averaging of Backscatter Intensities in Compounds

    Science.gov (United States)

    Donovan, John J.; Pingitore, Nicholas E.; Westphal, Andrew J.

    2002-01-01

    Low uncertainty measurements on pure element stable isotope pairs demonstrate that mass has no influence on the backscattering of electrons at typical electron microprobe energies. The traditional prediction of average backscatter intensities in compounds using elemental mass fractions is improperly grounded in mass and thus has no physical basis. We propose an alternative model to mass fraction averaging, based of the number of electrons or protons, termed “electron fraction,” which predicts backscatter yield better than mass fraction averaging. PMID:27446752

  11. Experimental Demonstration of Squeezed State Quantum Averaging

    CERN Document Server

    Lassen, Mikael; Sabuncu, Metin; Filip, Radim; Andersen, Ulrik L

    2010-01-01

    We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.

  12. Self-averaging characteristics of spectral fluctuations

    OpenAIRE

    Braun, Petr; Haake, Fritz

    2014-01-01

    The spectral form factor as well as the two-point correlator of the density of (quasi-)energy levels of individual quantum dynamics are not self-averaging. Only suitable smoothing turns them into useful characteristics of spectra. We present numerical data for a fully chaotic kicked top, employing two types of smoothing: one involves primitives of the spectral correlator, the second a small imaginary part of the quasi-energy. Self-averaging universal (like the CUE average) behavior is found f...

  13. Changing mortality and average cohort life expectancy

    DEFF Research Database (Denmark)

    Schoen, Robert; Canudas-Romo, Vladimir

    2005-01-01

    of survivorship. An alternative aggregate measure of period mortality which has been seen as less sensitive to period changes, the cross-sectional average length of life (CAL) has been proposed as an alternative, but has received only limited empirical or analytical examination. Here, we introduce a new measure......, the average cohort life expectancy (ACLE), to provide a precise measure of the average length of life of cohorts alive at a given time. To compare the performance of ACLE with CAL and with period and cohort life expectancy, we first use population models with changing mortality. Then the four aggregate...

  14. Weldon Spring historical dose estimate

    Energy Technology Data Exchange (ETDEWEB)

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.

  15. Weldon Spring historical dose estimate

    International Nuclear Information System (INIS)

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr

  16. Average Vegetation Growth 1992 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1992 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  17. Average Vegetation Growth 1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1994 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  18. Average Vegetation Growth 1991 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1991 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  19. Average Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  20. Average Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  1. Average Vegetation Growth 1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1999 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  2. Average Vegetation Growth 1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1990 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  3. Average Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  4. Sea Surface Temperature Average_SST_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface temperature collected via satellite imagery from http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.html and averaged for each region using...

  5. MN Temperature Average (1961-1990) - Polygon

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set depicts 30-year averages (1961-1990) of monthly and annual temperatures for Minnesota. Isolines and regions were created using kriging and...

  6. Average Vegetation Growth 2002 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2002 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  7. Average Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  8. Spacetime Average Density (SAD) Cosmological Measures

    CERN Document Server

    Page, Don N

    2014-01-01

    The measure problem of cosmology is how to obtain normalized probabilities of observations from the quantum state of the universe. This is particularly a problem when eternal inflation leads to a universe of unbounded size so that there are apparently infinitely many realizations or occurrences of observations of each of many different kinds or types, making the ratios ambiguous. There is also the danger of domination by Boltzmann Brains. Here two new Spacetime Average Density (SAD) measures are proposed, Maximal Average Density (MAD) and Biased Average Density (BAD), for getting a finite number of observation occurrences by using properties of the Spacetime Average Density (SAD) of observation occurrences to restrict to finite regions of spacetimes that have a preferred beginning or bounce hypersurface. These measures avoid Boltzmann brain domination and appear to give results consistent with other observations that are problematic for other widely used measures, such as the observation of a positive cosmolo...

  9. Averaging procedure in variable-G cosmologies

    CERN Document Server

    Cardone, Vincenzo F

    2008-01-01

    Previous work in the literature had built a formalism for spatially averaged equations for the scale factor, giving rise to an averaged Raychaudhuri equation and averaged Hamiltonian constraint, which involve a backreaction source term. The present paper extends these equations to include models with variable Newton parameter and variable cosmological term, motivated by the non-perturbative renormalization program for quantum gravity based upon the Einstein--Hilbert action. The coupling between backreaction and spatially averaged three-dimensional scalar curvature is found to survive, and all equations involving contributions of a variable Newton parameter are worked out in detail. Interestingly, under suitable assumptions, an approximate solution can be found where the universe tends to a FLRW model, while keeping track of the original inhomogeneities through two effective fluids.

  10. A practical guide to averaging functions

    CERN Document Server

    Beliakov, Gleb; Calvo Sánchez, Tomasa

    2016-01-01

    This book offers an easy-to-use and practice-oriented reference guide to mathematical averages. It presents different ways of aggregating input values given on a numerical scale, and of choosing and/or constructing aggregating functions for specific applications. Building on a previous monograph by Beliakov et al. published by Springer in 2007, it outlines new aggregation methods developed in the interim, with a special focus on the topic of averaging aggregation functions. It examines recent advances in the field, such as aggregation on lattices, penalty-based aggregation and weakly monotone averaging, and extends many of the already existing methods, such as: ordered weighted averaging (OWA), fuzzy integrals and mixture functions. A substantial mathematical background is not called for, as all the relevant mathematical notions are explained here and reported on together with a wealth of graphical illustrations of distinct families of aggregation functions. The authors mainly focus on practical applications ...

  11. MN Temperature Average (1961-1990) - Line

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set depicts 30-year averages (1961-1990) of monthly and annual temperatures for Minnesota. Isolines and regions were created using kriging and...

  12. Average Vegetation Growth 2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2001 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  13. Monthly snow/ice averages (ISCCP)

    Data.gov (United States)

    National Aeronautics and Space Administration — September Arctic sea ice is now declining at a rate of 11.5 percent per decade, relative to the 1979 to 2000 average. Data from NASA show that the land ice sheets...

  14. Modeling and Instability of Average Current Control

    OpenAIRE

    Fang, Chung-Chieh

    2012-01-01

    Dynamics and stability of average current control of DC-DC converters are analyzed by sampled-data modeling. Orbital stability is studied and it is found unrelated to the ripple size of the orbit. Compared with the averaged modeling, the sampled-data modeling is more accurate and systematic. An unstable range of compensator pole is found by simulations, and is predicted by sampled-data modeling and harmonic balance modeling.

  15. Nonequilibrium statistical averages and thermo field dynamics

    International Nuclear Information System (INIS)

    An extension of thermo field dynamics is proposed, which permits the computation of nonequilibrium statistical averages. The Brownian motion of a quantum oscillator is treated as an example. In conclusion it is pointed out that the procedure proposed to computation of time-dependent statistical average gives the correct two-point Green function for the damped oscillator. A simple extension can be used to compute two-point Green functions of free particles

  16. Average Bandwidth Allocation Model of WFQ

    Directory of Open Access Journals (Sweden)

    Tomáš Balogh

    2012-01-01

    Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.

  17. Disk-averaged synthetic spectra of Mars

    OpenAIRE

    Tinetti, Giovanna; Meadows, Victoria S.; Crisp, David; Fong, William; Velusamy, Thangasamy; Snively, Heather

    2004-01-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and ESA Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earth-sized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of the planet Mars to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra as a f...

  18. Verification of Internal Dose Calculations.

    Science.gov (United States)

    Aissi, Abdelmadjid

    The MIRD internal dose calculations have been in use for more than 15 years, but their accuracy has always been questionable. There have been attempts to verify these calculations; however, these attempts had various shortcomings which kept the question of verification of the MIRD data still unanswered. The purpose of this research was to develop techniques and methods to verify the MIRD calculations in a more systematic and scientific manner. The research consisted of improving a volumetric dosimeter, developing molding techniques, and adapting the Monte Carlo computer code ALGAM to the experimental conditions and vice versa. The organic dosimetric system contained TLD-100 powder and could be shaped to represent human organs. The dosimeter possessed excellent characteristics for the measurement of internal absorbed doses, even in the case of the lungs. The molding techniques are inexpensive and were used in the fabrication of dosimetric and radioactive source organs. The adaptation of the computer program provided useful theoretical data with which the experimental measurements were compared. The experimental data and the theoretical calculations were compared for 6 source organ-7 target organ configurations. The results of the comparison indicated the existence of an agreement between measured and calculated absorbed doses, when taking into consideration the average uncertainty (16%) of the measurements, and the average coefficient of variation (10%) of the Monte Carlo calculations. However, analysis of the data gave also an indication that the Monte Carlo method might overestimate the internal absorbed doses. Even if the overestimate exists, at least it could be said that the use of the MIRD method in internal dosimetry was shown to lead to no unnecessary exposure to radiation that could be caused by underestimating the absorbed dose. The experimental and the theoretical data were also used to test the validity of the Reciprocity Theorem for heterogeneous

  19. Trends in doses to radiation workers recorded on the Central Index of Dose Information

    International Nuclear Information System (INIS)

    This paper presents a preliminary analysis of the doses stored on the Central Index of Dose Information for the calendar years 1986, 1987 and 1988. Mean doses are low, and both mean doses and the proportion of workers exceeding 15 mSv in a year are decreasing with time. Underground miners are the occupational group receiving the highest doses, though in this and other relatively high dose groups the exposures are falling with time. Only 6% of workers are female and their average individual dose is about half that of men. Patterns of employment are different for women and men but there is a tendency for women to receive lower doses than men even within the same occupation. (author)

  20. Comparison of Mouse Brain DTI Maps Using K-space Average, Image-space Average, or No Average Approach

    OpenAIRE

    Sun, Shu-Wei; Mei, Jennifer; Tuel, Keelan

    2013-01-01

    Diffusion tensor imaging (DTI) is achieved by collecting a series of diffusion-weighted images (DWIs). Signal averaging of multiple repetitions can be performed in the k-space (k-avg) or in the image space (m-avg) to improve the image quality. Alternatively, one can treat each acquisition as an independent image and use all of the data to reconstruct the DTI without doing any signal averaging (no-avg). To compare these three approaches, in this study, in vivo DTI data was collected from five ...

  1. Toward high-contrast breast CT at low radiation dose.

    Science.gov (United States)

    Keyriläinen, Jani; Fernández, Manuel; Karjalainen-Lindsberg, Marja-Liisa; Virkkunen, Pekka; Leidenius, Marjut; von Smitten, Karl; Sipilä, Petri; Fiedler, Stefan; Suhonen, Heikki; Suortti, Pekka; Bravin, Alberto

    2008-10-01

    This study was approved by the local research ethics committee, and patient informed consent was obtained. The purpose of this study was to demonstrate that high-spatial-resolution low-dose analyzer-based x-ray computed tomography (CT) can substantially improve the radiographic contrast of breast tissue in vitro when compared with that attained by using diagnostic mammography and CT. An excised human breast tumor was examined by using analyzer-based x-ray imaging with synchrotron radiation. The correspondence between analyzer-based x-ray images and diagnostic mammograms, CT images, and histopathologic findings was determined. Calcifications and fine details of soft tissue, which are at the contrast detection limit on diagnostic mammograms, are clearly visible on planar analyzer-based x-ray images. Analyzer-based x-ray CT yields high contrast from smoothly varying internal structures, such as tumorous mass lesions, corresponding to information on actual structures seen at histopathologic analysis. The mean glandular dose of 1.9 mGy in analyzer-based x-ray CT is approximately equivalent to the dose administered during single-view screening mammography. The improved visibility of mammographically indistinguishable lesions in vitro suggests that analyzer-based x-ray CT may be a valuable method in radiographic evaluation of the breast, thereby justifying further investigations. PMID:18796684

  2. Patient Dosimetry in Arteriography of the Lower Limbs. Part II: Dose Conversion Coefficients, Organ Doses and Effective Dose

    International Nuclear Information System (INIS)

    X ray projection data (see Part I) and GSF phantoms ADAM and EVA were used as input for the GSF Monte Carlo transport code to calculate hitherto unavailable dose conversion coefficients (DCCs) for common projections in arteriography of the lower limbs. These DCCs served to estimate organ equivalent doses and effective dose in a study of 455 patients. The effective dose caused by percutaneous needle puncture arteriography of one leg was on average 1 mSv, by Seldinger catherisation for arteriography of both legs 4 mSv, and by intravenous digital subtraction arteriography (DSA) 5 mSv. For needle puncture and Seldinger arteriography the effective dose attributable to fluoroscopy was about 50% for male and 60% for female patients. The contribution of DSA was between 15 and 35%, that of cut films between 17 to 28%, depending on gender and procedure. The effective dose in intravenous arteriography was mainly due to DSA (91-93%). (author)

  3. Basics of averaging of the Maxwell equations

    CERN Document Server

    Chipouline, A; Tretyakov, S

    2011-01-01

    Volume or statistical averaging of the microscopic Maxwell equations (MEs), i.e. transition from microscopic MEs to their macroscopic counterparts, is one of the main steps in electrodynamics of materials. In spite of the fundamental importance of the averaging procedure, it is quite rarely properly discussed in university courses and respective books; up to now there is no established consensus about how the averaging procedure has to be performed. In this paper we show that there are some basic principles for the averaging procedure (irrespective to what type of material is studied) which have to be satisfied. Any homogenization model has to be consistent with the basic principles. In case of absence of this correlation of a particular model with the basic principles the model could not be accepted as a credible one. Another goal of this paper is to establish the averaging procedure for metamaterials, which is rather close to the case of compound materials but should include magnetic response of the inclusi...

  4. Evaluation of the usefulness for air gap technique in digital magnification mammography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young [Dept. of Diagnostic Radiology, Dankook University Hospital, Cheonan (Korea, Republic of)

    2014-06-15

    The purpose of this study was investigated optimal exposure condition in digital magnification mammography to decrease radiation dose and increase image quality of the examine. Auto mode, the average glandular dose is higher than the manual mode. Average glandular dose and image quality were many differences on between grid and air gap technique in auto mode. However, Average glandular dose and signal-to-noise ratio were not different on between grid and air gap technique in manual mode. The signal-to-noise ratio was increased when using the air-gap technique in both mode. According to result, air gap technique may reduce average glandular dose and increase signal-to-noise ratio in digital magnification mammography.

  5. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade. PMID:24416159

  6. Cosmic structure, averaging and dark energy

    CERN Document Server

    Wiltshire, David L

    2013-01-01

    These lecture notes review the theoretical problems associated with coarse-graining the observed inhomogeneous structure of the universe at late epochs, of describing average cosmic evolution in the presence of growing inhomogeneity, and of relating average quantities to physical observables. In particular, a detailed discussion of the timescape scenario is presented. In this scenario, dark energy is realized as a misidentification of gravitational energy gradients which result from gradients in the kinetic energy of expansion of space, in the presence of density and spatial curvature gradients that grow large with the growth of structure. The phenomenology and observational tests of the timescape model are discussed in detail, with updated constraints from Planck satellite data. In addition, recent results on the variation of the Hubble expansion on < 100/h Mpc scales are discussed. The spherically averaged Hubble law is significantly more uniform in the rest frame of the Local Group of galaxies than in t...

  7. Books average previous decade of economic misery.

    Directory of Open Access Journals (Sweden)

    R Alexander Bentley

    Full Text Available For the 20(th century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  8. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  9. Matrix averages relating to Ginibre ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, Peter J [Department of Mathematics and Statistics, University of Melbourne, Victoria 3010 (Australia); Rains, Eric M [Department of Mathematics, California Institute of Technology, Pasadena, CA 91125 (United States)], E-mail: p.forrester@ms.unimelb.edu.au

    2009-09-25

    The theory of zonal polynomials is used to compute the average of a Schur polynomial of argument AX, where A is a fixed matrix and X is from the real Ginibre ensemble. This generalizes a recent result of Sommers and Khoruzhenko (2009 J. Phys. A: Math. Theor. 42 222002), and furthermore allows analogous results to be obtained for the complex and real quaternion Ginibre ensembles. As applications, the positive integer moments of the general variance Ginibre ensembles are computed in terms of generalized hypergeometric functions; these are written in terms of averages over matrices of the same size as the moment to give duality formulas, and the averages of the power sums of the eigenvalues are expressed as finite sums of zonal polynomials.

  10. Stochastic Averaging and Stochastic Extremum Seeking

    CERN Document Server

    Liu, Shu-Jun

    2012-01-01

    Stochastic Averaging and Stochastic Extremum Seeking develops methods of mathematical analysis inspired by the interest in reverse engineering  and analysis of bacterial  convergence by chemotaxis and to apply similar stochastic optimization techniques in other environments. The first half of the text presents significant advances in stochastic averaging theory, necessitated by the fact that existing theorems are restricted to systems with linear growth, globally exponentially stable average models, vanishing stochastic perturbations, and prevent analysis over infinite time horizon. The second half of the text introduces stochastic extremum seeking algorithms for model-free optimization of systems in real time using stochastic perturbations for estimation of their gradients. Both gradient- and Newton-based algorithms are presented, offering the user the choice between the simplicity of implementation (gradient) and the ability to achieve a known, arbitrary convergence rate (Newton). The design of algorithms...

  11. Average Cycle Period in Asymmetrical Flashing Ratchet

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-Yan; HE Hou-Sheng; BAO Jing-Dong

    2005-01-01

    The directed motion of a Brownian particle in a flashing potential with various transition probabilities and waiting times in one of two states is studied. An expression for the average cycle period is proposed and the steady current J of the particle is calculated via Langevin simulation. The results show that the optimal cycle period rm,which takes the maximum of J, is shifted to a small value when the transition probability λ from the potential on to the potential off decreases, the maximalcurrent appears in the case of the average waiting time in the potential on being longer than in the potential off, and the direction of current depends on the ratio of the average times waiting in two states.

  12. Average Cross Section Evaluation - Room for Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Frohner, G.H. [Forschungszentrum Karlsruhe Institut fur Kern- und Energietechnik, Karlsruhe (Germany)

    2006-07-01

    Full text of publication follows: Techniques for evaluation of average nuclear cross sections are well established. Nevertheless there seems room for improvement. Heuristic expressions for average partial cross sections of the Hauser-Feshbach type with width fluctuation corrections could be replaced by the correct GOE triple integral. Transmission coefficients derived from macroscopic models (optical, single and double hump fission barrier, etc) lead to better descriptions of cross section behaviour over wide energy ranges. At higher energies (n,{gamma}n') reactions compete with radiative capture (Moldauer effect). In all cross section modeling one must distinguish properly between average S- and R-matrix parameters. The exact relationship between them is given, as well as the connection to Endf format rules. Fitting codes (e.g. FITACS) should be able to digest observed data directly, instead of only reduced data corrected already for self shielding and multiple scattering (e.g. with SESH). (author)

  13. Model averaging and muddled multimodel inferences.

    Science.gov (United States)

    Cade, Brian S

    2015-09-01

    Three flawed practices associated with model averaging coefficients for predictor variables in regression models commonly occur when making multimodel inferences in analyses of ecological data. Model-averaged regression coefficients based on Akaike information criterion (AIC) weights have been recommended for addressing model uncertainty but they are not valid, interpretable estimates of partial effects for individual predictors when there is multicollinearity among the predictor variables. Multicollinearity implies that the scaling of units in the denominators of the regression coefficients may change across models such that neither the parameters nor their estimates have common scales, therefore averaging them makes no sense. The associated sums of AIC model weights recommended to assess relative importance of individual predictors are really a measure of relative importance of models, with little information about contributions by individual predictors compared to other measures of relative importance based on effects size or variance reduction. Sometimes the model-averaged regression coefficients for predictor variables are incorrectly used to make model-averaged predictions of the response variable when the models are not linear in the parameters. I demonstrate the issues with the first two practices using the college grade point average example extensively analyzed by Burnham and Anderson. I show how partial standard deviations of the predictor variables can be used to detect changing scales of their estimates with multicollinearity. Standardizing estimates based on partial standard deviations for their variables can be used to make the scaling of the estimates commensurate across models, a necessary but not sufficient condition for model averaging of the estimates to be sensible. A unimodal distribution of estimates and valid interpretation of individual parameters are additional requisite conditions. The standardized estimates or equivalently the t

  14. Books Average Previous Decade of Economic Misery

    OpenAIRE

    R Alexander Bentley; Alberto Acerbi; Paul Ormerod; Vasileios Lampos

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is signific...

  15. An improved moving average technical trading rule

    Science.gov (United States)

    Papailias, Fotis; Thomakos, Dimitrios D.

    2015-06-01

    This paper proposes a modified version of the widely used price and moving average cross-over trading strategies. The suggested approach (presented in its 'long only' version) is a combination of cross-over 'buy' signals and a dynamic threshold value which acts as a dynamic trailing stop. The trading behaviour and performance from this modified strategy are different from the standard approach with results showing that, on average, the proposed modification increases the cumulative return and the Sharpe ratio of the investor while exhibiting smaller maximum drawdown and smaller drawdown duration than the standard strategy.

  16. A singularity theorem based on spatial averages

    Indian Academy of Sciences (India)

    J M M Senovilla

    2007-07-01

    Inspired by Raychaudhuri's work, and using the equation named after him as a basic ingredient, a new singularity theorem is proved. Open non-rotating Universes, expanding everywhere with a non-vanishing spatial average of the matter variables, show severe geodesic incompletness in the past. Another way of stating the result is that, under the same conditions, any singularity-free model must have a vanishing spatial average of the energy density (and other physical variables). This is very satisfactory and provides a clear decisive difference between singular and non-singular cosmologies.

  17. Average-case analysis of numerical problems

    CERN Document Server

    2000-01-01

    The average-case analysis of numerical problems is the counterpart of the more traditional worst-case approach. The analysis of average error and cost leads to new insight on numerical problems as well as to new algorithms. The book provides a survey of results that were mainly obtained during the last 10 years and also contains new results. The problems under consideration include approximation/optimal recovery and numerical integration of univariate and multivariate functions as well as zero-finding and global optimization. Background material, e.g. on reproducing kernel Hilbert spaces and random fields, is provided.

  18. Image quality and dose in mammographic images obtained in Mexico City hospitals

    International Nuclear Information System (INIS)

    The performance of three mammographic systems in large Mexican hospitals has been evaluated, as well as the image quality and associated dose. Quality control tests include examination of X-ray equipment, darkroom conditions, film processor, and viewboxes. Systems referred to as '1', '2', and '3' passed 50%, 75% and 75% of these tests, respectively. Quality image is assessed using five images obtained under similar nominal conditions in each X-ray equipment. System 1 generates no image of acceptable quality, while equipment 2 and 3 produce one and two, respectively. The mean glandular dose for the best images obtained in each service with an accreditation phantom has been measured, and the values are 1.4 mGy, 1.6 mGy, and 1.0 mGy, respectively. (author)

  19. Dose forming in rural settlement: family analysis

    International Nuclear Information System (INIS)

    The aim of the study is the multifactor statistic families analysis of ingestion dose in rural settlement. The hypothesis of the determining role of a family as of social system in dose forming in rural settlement, has been approved. The most significant social-demographic features of a family influencing dose forming, were detected: the number of members of the family, number of children, average age, education and occupational orientation of the family. Despite their being linked with similar features of the family on the whole, age, education, occupation and gender of master of the family, influence most the dose forming. Young families with many children in which the master is a worker, having frequent contact with forest, have high doses. The knowledge of social structure of families will allow to predict the ingestion dose distribution in rural settlement. (Author)

  20. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    Science.gov (United States)

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses. PMID:27218294

  1. Calculation of midplane dose for total body irradiation from entrance and exit dose MOSFET measurements.

    Science.gov (United States)

    Satory, P R

    2012-03-01

    This work is the development of a MOSFET based surface in vivo dosimetry system for total body irradiation patients treated with bilateral extended SSD beams using PMMA missing tissue compensators adjacent to the patient. An empirical formula to calculate midplane dose from MOSFET measured entrance and exit doses has been derived. The dependency of surface dose on the air-gap between the spoiler and the surface was investigated by suspending a spoiler above a water phantom, and taking percentage depth dose measurements (PDD). Exit and entrances doses were measured with MOSFETs in conjunction with midplane doses measured with an ion chamber. The entrance and exit doses were combined using an exponential attenuation formula to give an estimate of midplane dose and were compared to the midplane ion chamber measurement for a range of phantom thicknesses. Having a maximum PDD at the surface simplifies the prediction of midplane dose, which is achieved by ensuring that the air gap between the compensator and the surface is less than 10 cm. The comparison of estimated midplane dose and measured midplane dose showed no dependence on phantom thickness and an average correction factor of 0.88 was found. If the missing tissue compensators are kept within 10 cm of the patient then MOSFET measurements of entrance and exit dose can predict the midplane dose for the patient. PMID:22298238

  2. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  3. Average beta measurement in EXTRAP T1

    International Nuclear Information System (INIS)

    Beginning with the ideal MHD pressure balance equation, an expression for the average poloidal beta, ΒΘ, is derived. A method for unobtrusively measuring the quantities used to evaluate ΒΘ in Extrap T1 is described. The results if a series of measurements yielding ΒΘ as a function of externally applied toroidal field are presented. (author)

  4. Quantum Averaging of Squeezed States of Light

    DEFF Research Database (Denmark)

    Squeezing has been recognized as the main resource for quantum information processing and an important resource for beating classical detection strategies. It is therefore of high importance to reliably generate stable squeezing over longer periods of time. The averaging procedure for a single qu...

  5. An approximate analytical approach to resampling averages

    DEFF Research Database (Denmark)

    Malzahn, Dorthe; Opper, M.

    2004-01-01

    Using a novel reformulation, we develop a framework to compute approximate resampling data averages analytically. The method avoids multiple retraining of statistical models on the samples. Our approach uses a combination of the replica "trick" of statistical physics and the TAP approach for appr...

  6. Discontinuities and hysteresis in quantized average consensus

    NARCIS (Netherlands)

    Ceragioli, Francesca; Persis, Claudio De; Frasca, Paolo

    2011-01-01

    We consider continuous-time average consensus dynamics in which the agents’ states are communicated through uniform quantizers. Solutions to the resulting system are defined in the Krasowskii sense and are proven to converge to conditions of ‘‘practical consensus’’. To cope with undesired chattering

  7. Error estimates on averages of correlated data

    International Nuclear Information System (INIS)

    We describe how the true statistical error on an average of correlated data can be obtained with ease and efficiency by a renormalization group method. The method is illustrated with numerical and analytical examples, having finite as well as infinite range correlations. (orig.)

  8. Average utility maximization: A preference foundation

    NARCIS (Netherlands)

    A.V. Kothiyal (Amit); V. Spinu (Vitalie); P.P. Wakker (Peter)

    2014-01-01

    textabstractThis paper provides necessary and sufficient preference conditions for average utility maximization over sequences of variable length. We obtain full generality by using a new algebraic technique that exploits the richness structure naturally provided by the variable length of the sequen

  9. High average-power induction linacs

    Energy Technology Data Exchange (ETDEWEB)

    Prono, D.S.; Barrett, D.; Bowles, E.; Caporaso, G.J.; Chen, Yu-Jiuan; Clark, J.C.; Coffield, F.; Newton, M.A.; Nexsen, W.; Ravenscroft, D.

    1989-03-15

    Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs.

  10. Bayesian Model Averaging for Propensity Score Analysis

    Science.gov (United States)

    Kaplan, David; Chen, Jianshen

    2013-01-01

    The purpose of this study is to explore Bayesian model averaging in the propensity score context. Previous research on Bayesian propensity score analysis does not take into account model uncertainty. In this regard, an internally consistent Bayesian framework for model building and estimation must also account for model uncertainty. The…

  11. Bayesian Averaging is Well-Temperated

    DEFF Research Database (Denmark)

    Hansen, Lars Kai

    2000-01-01

    Bayesian predictions are stochastic just like predictions of any other inference scheme that generalize from a finite sample. While a simple variational argument shows that Bayes averaging is generalization optimal given that the prior matches the teacher parameter distribution the situation...

  12. Generalized Jackknife Estimators of Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    With the aim of improving the quality of asymptotic distributional approximations for nonlinear functionals of nonparametric estimators, this paper revisits the large-sample properties of an important member of that class, namely a kernel-based weighted average derivative estimator. Asymptotic...

  13. Independence, Odd Girth, and Average Degree

    DEFF Research Database (Denmark)

    Löwenstein, Christian; Pedersen, Anders Sune; Rautenbach, Dieter;

    2011-01-01

      We prove several tight lower bounds in terms of the order and the average degree for the independence number of graphs that are connected and/or satisfy some odd girth condition. Our main result is the extension of a lower bound for the independence number of triangle-free graphs of maximum...

  14. Bootstrapping Density-Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    Employing the "small bandwidth" asymptotic framework of Cattaneo, Crump, and Jansson (2009), this paper studies the properties of a variety of bootstrap-based inference procedures associated with the kernel-based density-weighted averaged derivative estimator proposed by Powell, Stock, and Stoker...

  15. A dynamic analysis of moving average rules

    NARCIS (Netherlands)

    C. Chiarella; X.Z. He; C.H. Hommes

    2006-01-01

    The use of various moving average (MA) rules remains popular with financial market practitioners. These rules have recently become the focus of a number empirical studies, but there have been very few studies of financial market models where some agents employ technical trading rules of the type use

  16. Assessment of subject doses in mammography and its implication in the screening practice

    International Nuclear Information System (INIS)

    The aim of this paper is to evaluate the equivalent dose to breasts and effective dose from typical mammographic procedure. To calculate the contribution to effective dose from scattered radiation was used an MIRD-type whole body phantom of adult female. In this study, transformed the original MIRD female breast model to simulate the compressed breast. To determine the size of breast, mammographic procedure data were collected from the Korea Cancer Center Hospital in Seoul. These values were applied to the geometrical modeling of compressed breast. Mammographic units chosen for modeling are GE Senographe 600T and LORAD M-IV. Dose assessment was conducted for breast material of gland, homogeneous 50:50 mixture of adipose and glandular tissue, and sole adipose. Patient doses were calculated using the general-purposed Monte Carlo code, MCNPX. The X-ray spectra provided by the SPEC 78 data library were used. The difference in breast dose due to the different breast material compositions and different units was small. The equivalent doses to the breast were decreased aat other ages to became 2.25 mSv for patients undergoing craniocaudal in their 20's and the lowest dose is 0.68 mSv undergoing craniocaudal in their 60's. Similar trend was observed in the mediolateral projections. The contribution of other organ doses to effective does is found negligible so that the effective doses were approximately one-tenth the breast dose. The result of assessment of subject doses in mammography may provide reference of screening practice and groundwork for the national health in radiology

  17. Medical exposure and effective dose

    International Nuclear Information System (INIS)

    The frequency of radiological diagnosis in Japan and individual population effective dose are reported. Questionnaire on radiological practice was delivered to selected medical facilities. The total number of X-ray diagnosis performed in 1991 was 180,000,000, being age-dependent in both men and women. The chest was the most common site to be examined. The number of X-ray films per examination was the highest for the stomach. The spread of ultrasound has decreased radiological practice in the obstetric field (approximately one sixth between 1979 and 1986). There was an 8-fold increase in the number of X-ray CT as of 1989 during the past decade. The total number of CT scanning in 1989 reached nearly 14,850,000 (about 16 times as much as that of 1979). The number of stomach X-ray screening increased to 7,800,000 which is twice as much as that in 1975. In the dental field, panoramic method brought about a 7-fold increase between 1974 and 1985. The frequency of nuclear medicine diagnosis has slightly increased, reaching 1,400,000 cases in 1992, and 99mTc was the most common nuclide. The total population effective dose of radiography and fluoroscopy was 179,000 mSv. The highest effective dose was associated with gastric X-ray. The effective dose equivalent per diagnosis was estimated to be 1.02 mSv (the total population/total number of radiological diagnosis). The population effective dose per person was 2.3 mSv (population effective dose equivalent/national population), which was equal to the world average of yearly effective dose equivalent of natural radiation. (S.Y.)

  18. Benchmark Dose Modeling

    Science.gov (United States)

    Finite doses are employed in experimental toxicology studies. Under the traditional methodology, the point of departure (POD) value for low dose extrapolation is identified as one of these doses. Dose spacing necessarily precludes a more accurate description of the POD value. ...

  19. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    Energy Technology Data Exchange (ETDEWEB)

    Belley, Matthew D.; Wang, Chu [Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Nguyen, Giao; Gunasingha, Rathnayaka [Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710 (United States); Chao, Nelson J. [Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710 and Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Chen, Benny J. [Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710 (United States); Dewhirst, Mark W. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Yoshizumi, Terry T., E-mail: terry.yoshizumi@duke.edu [Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-03-15

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.

  20. Dose in x-ray computed tomography.

    Science.gov (United States)

    Kalender, Willi A

    2014-02-01

    Radiation dose in x-ray computed tomography (CT) has become a topic of high interest due to the increasing numbers of CT examinations performed worldwide. This review aims to present an overview of current concepts for both scanner output metrics and for patient dosimetry and will comment on their strengths and weaknesses. Controversial issues such as the appropriateness of the CT dose index (CTDI) are discussed in detail. A review of approaches to patient dose assessment presently in practice, of the dose levels encountered and options for further dose optimization are also given and discussed. Patient dose assessment remains a topic for further improvement and for international consensus. All approaches presently in use are based on Monte Carlo (MC) simulations. Estimates for effective dose are established, but they are crude and not patient-specific; organ dose estimates are rarely available. Patient- and organ-specific dose estimates can be provided with adequate accuracy and independent of CTDI phantom measurements by fast MC simulations. Such information, in particular on 3D dose distributions, is important and helpful in optimization efforts. Dose optimization has been performed very successfully in recent years and even resulted in applications with effective dose values of below 1 mSv. In general, a trend towards lower dose values based on technical innovations has to be acknowledged. Effective dose values are down to clearly below 10 mSv on average, and there are a number of applications such as cardiac and pediatric CT which are performed routinely below 1 mSv on modern equipment. PMID:24434792

  1. Monte Carlo dose mapping on deforming anatomy

    Science.gov (United States)

    Zhong, Hualiang; Siebers, Jeffrey V.

    2009-10-01

    This paper proposes a Monte Carlo-based energy and mass congruent mapping (EMCM) method to calculate the dose on deforming anatomy. Different from dose interpolation methods, EMCM separately maps each voxel's deposited energy and mass from a source image to a reference image with a displacement vector field (DVF) generated by deformable image registration (DIR). EMCM was compared with other dose mapping methods: energy-based dose interpolation (EBDI) and trilinear dose interpolation (TDI). These methods were implemented in EGSnrc/DOSXYZnrc, validated using a numerical deformable phantom and compared for clinical CT images. On the numerical phantom with an analytically invertible deformation map, EMCM mapped the dose exactly the same as its analytic solution, while EBDI and TDI had average dose errors of 2.5% and 6.0%. For a lung patient's IMRT treatment plan, EBDI and TDI differed from EMCM by 1.96% and 7.3% in the lung patient's entire dose region, respectively. As a 4D Monte Carlo dose calculation technique, EMCM is accurate and its speed is comparable to 3D Monte Carlo simulation. This method may serve as a valuable tool for accurate dose accumulation as well as for 4D dosimetry QA.

  2. Averaged Extended Tree Augmented Naive Classifier

    Directory of Open Access Journals (Sweden)

    Aaron Meehan

    2015-07-01

    Full Text Available This work presents a new general purpose classifier named Averaged Extended Tree Augmented Naive Bayes (AETAN, which is based on combining the advantageous characteristics of Extended Tree Augmented Naive Bayes (ETAN and Averaged One-Dependence Estimator (AODE classifiers. We describe the main properties of the approach and algorithms for learning it, along with an analysis of its computational time complexity. Empirical results with numerous data sets indicate that the new approach is superior to ETAN and AODE in terms of both zero-one classification accuracy and log loss. It also compares favourably against weighted AODE and hidden Naive Bayes. The learning phase of the new approach is slower than that of its competitors, while the time complexity for the testing phase is similar. Such characteristics suggest that the new classifier is ideal in scenarios where online learning is not required.

  3. Grassmann Averages for Scalable Robust PCA

    DEFF Research Database (Denmark)

    Hauberg, Søren; Feragen, Aasa; Black, Michael J.

    2014-01-01

    As the collection of large datasets becomes increasingly automated, the occurrence of outliers will increase—“big data” implies “big outliers”. While principal component analysis (PCA) is often used to reduce the size of data, and scalable solutions exist, it is well-known that outliers can...... can be efficiently computed, we immediately gain scalability. GA is inherently more robust than PCA, but we show that they coincide for Gaussian data. We exploit that averages can be made robust to formulate the Robust Grassmann Average (RGA) as a form of robust PCA. Robustness can be with respect......, making it scalable to “big noisy data.” We demonstrate TGA for background modeling, video restoration, and shadow removal. We show scalability by performing robust PCA on the entire Star Wars IV movie....

  4. ANALYSIS OF THE FACTORS AFFECTING THE AVERAGE

    Directory of Open Access Journals (Sweden)

    Carmen BOGHEAN

    2013-12-01

    Full Text Available Productivity in agriculture most relevantly and concisely expresses the economic efficiency of using the factors of production. Labour productivity is affected by a considerable number of variables (including the relationship system and interdependence between factors, which differ in each economic sector and influence it, giving rise to a series of technical, economic and organizational idiosyncrasies. The purpose of this paper is to analyse the underlying factors of the average work productivity in agriculture, forestry and fishing. The analysis will take into account the data concerning the economically active population and the gross added value in agriculture, forestry and fishing in Romania during 2008-2011. The distribution of the average work productivity per factors affecting it is conducted by means of the u-substitution method.

  5. Trajectory averaging for stochastic approximation MCMC algorithms

    CERN Document Server

    Liang, Faming

    2010-01-01

    The subject of stochastic approximation was founded by Robbins and Monro [Ann. Math. Statist. 22 (1951) 400--407]. After five decades of continual development, it has developed into an important area in systems control and optimization, and it has also served as a prototype for the development of adaptive algorithms for on-line estimation and control of stochastic systems. Recently, it has been used in statistics with Markov chain Monte Carlo for solving maximum likelihood estimation problems and for general simulation and optimizations. In this paper, we first show that the trajectory averaging estimator is asymptotically efficient for the stochastic approximation MCMC (SAMCMC) algorithm under mild conditions, and then apply this result to the stochastic approximation Monte Carlo algorithm [Liang, Liu and Carroll J. Amer. Statist. Assoc. 102 (2007) 305--320]. The application of the trajectory averaging estimator to other stochastic approximation MCMC algorithms, for example, a stochastic approximation MLE al...

  6. Average Regression-Adjusted Controlled Regenerative Estimates

    OpenAIRE

    Lewis, Peter A.W.; Ressler, Richard

    1991-01-01

    Proceedings of the 1991 Winter Simulation Conference Barry L. Nelson, W. David Kelton, Gordon M. Clark (eds.) One often uses computer simulations of queueing systems to generate estimates of system characteristics along with estimates of their precision. Obtaining precise estimates, espescially for high traffic intensities, can require large amounts of computer time. Average regression-adjusted controlled regenerative estimates result from combining the two techniques ...

  7. Endogenous average cost based access pricing

    OpenAIRE

    Fjell, Kenneth; Foros, Øystein; Pal, Debashis

    2006-01-01

    We consider an industry where a downstream competitor requires access to an upstream facility controlled by a vertically integrated and regulated incumbent. The literature on access pricing assumes the access price to be exogenously fixed ex-ante. We analyze an endogenous average cost based access pricing rule, where both firms realize the interdependence among their quantities and the regulated access price. Endogenous access pricing neutralizes the artificial cost advantag...

  8. Average Drift Analysis and Population Scalability

    OpenAIRE

    He, Jun; Yao, Xin

    2013-01-01

    This paper aims to study how the population size affects the computation time of evolutionary algorithms in a rigorous way. The computation time of an evolutionary algorithm can be measured by either the expected number of generations (hitting time) or the expected number of fitness evaluations (running time) to find an optimal solution. Population scalability is the ratio of the expected hitting time between a benchmark algorithm and an algorithm using a larger population size. Average drift...

  9. On Heroes and Average Moral Human Beings

    OpenAIRE

    Kirchgässner, Gebhard

    2001-01-01

    After discussing various approaches about heroic behaviour in the literature, we first give a definition and classification of moral behaviour, in distinction to intrinsically motivated and ‘prudent' behaviour. Then, we present some arguments on the function of moral behaviour according to ‘minimal' standards of the average individual in a modern democratic society, before we turn to heroic behaviour. We conclude with some remarks on methodological as well as social problems which arise or ma...

  10. Time-dependent angularly averaged inverse transport

    OpenAIRE

    Bal, Guillaume; Jollivet, Alexandre

    2009-01-01

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured al...

  11. A Visibility Graph Averaging Aggregation Operator

    OpenAIRE

    Chen, Shiyu; Hu, Yong; Mahadevan, Sankaran; Deng, Yong

    2013-01-01

    The problem of aggregation is considerable importance in many disciplines. In this paper, a new type of operator called visibility graph averaging (VGA) aggregation operator is proposed. This proposed operator is based on the visibility graph which can convert a time series into a graph. The weights are obtained according to the importance of the data in the visibility graph. Finally, the VGA operator is used in the analysis of the TAIEX database to illustrate that it is practical and compare...

  12. Dollar-Cost Averaging: An Investigation

    OpenAIRE

    Fang, Wei

    2007-01-01

    Dollar-cost Averaging (DCA) is a common and useful systematic investment strategy for mutual fund managers, private investors, financial analysts and retirement planners. The issue of performance effectiveness of DCA is greatly controversial among academics and professionals. As a popularly recommended investment strategy, DCA is recognized as a risk reduction strategy; however, the advantage was claimed as the expense of generating higher returns. The dissertation is to intensively inves...

  13. Average Annual Rainfall over the Globe

    Science.gov (United States)

    Agrawal, D. C.

    2013-01-01

    The atmospheric recycling of water is a very important phenomenon on the globe because it not only refreshes the water but it also redistributes it over land and oceans/rivers/lakes throughout the globe. This is made possible by the solar energy intercepted by the Earth. The half of the globe facing the Sun, on the average, intercepts 1.74 ×…

  14. Geomagnetic effects on the average surface temperature

    Science.gov (United States)

    Ballatore, P.

    Several results have previously shown as the solar activity can be related to the cloudiness and the surface solar radiation intensity (Svensmark and Friis-Christensen, J. Atmos. Sol. Terr. Phys., 59, 1225, 1997; Veretenenkoand Pudovkin, J. Atmos. Sol. Terr. Phys., 61, 521, 1999). Here, the possible relationships between the averaged surface temperature and the solar wind parameters or geomagnetic activity indices are investigated. The temperature data used are the monthly SST maps (generated at RAL and available from the related ESRIN/ESA database) that represent the averaged surface temperature with a spatial resolution of 0.5°x0.5° and cover the entire globe. The interplanetary data and the geomagnetic data are from the USA National Space Science Data Center. The time interval considered is 1995-2000. Specifically, possible associations and/or correlations of the average temperature with the interplanetary magnetic field Bz component and with the Kp index are considered and differentiated taking into account separate geographic and geomagnetic planetary regions.

  15. On Backus average for generally anisotropic layers

    CERN Document Server

    Bos, Len; Slawinski, Michael A; Stanoev, Theodore

    2016-01-01

    In this paper, following the Backus (1962) approach, we examine expressions for elasticity parameters of a homogeneous generally anisotropic medium that is long-wave-equivalent to a stack of thin generally anisotropic layers. These expressions reduce to the results of Backus (1962) for the case of isotropic and transversely isotropic layers. In over half-a-century since the publications of Backus (1962) there have been numerous publications applying and extending that formulation. However, neither George Backus nor the authors of the present paper are aware of further examinations of mathematical underpinnings of the original formulation; hence, this paper. We prove that---within the long-wave approximation---if the thin layers obey stability conditions then so does the equivalent medium. We examine---within the Backus-average context---the approximation of the average of a product as the product of averages, and express it as a proposition in terms of an upper bound. In the presented examination we use the e...

  16. Spatial averaging infiltration model for layered soil

    Institute of Scientific and Technical Information of China (English)

    HU HePing; YANG ZhiYong; TIAN FuQiang

    2009-01-01

    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.

  17. Spatial averaging infiltration model for layered soil

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    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 hetero- geneity 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 overes- timate 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 hy- drological and land surface process modeling in a promising way.

  18. Unscrambling The "Average User" Of Habbo Hotel

    Directory of Open Access Journals (Sweden)

    Mikael Johnson

    2007-01-01

    Full Text Available The “user” is an ambiguous concept in human-computer interaction and information systems. Analyses of users as social actors, participants, or configured users delineate approaches to studying design-use relationships. Here, a developer’s reference to a figure of speech, termed the “average user,” is contrasted with design guidelines. The aim is to create an understanding about categorization practices in design through a case study about the virtual community, Habbo Hotel. A qualitative analysis highlighted not only the meaning of the “average user,” but also the work that both the developer and the category contribute to this meaning. The average user a represents the unknown, b influences the boundaries of the target user groups, c legitimizes the designer to disregard marginal user feedback, and d keeps the design space open, thus allowing for creativity. The analysis shows how design and use are intertwined and highlights the developers’ role in governing different users’ interests.

  19. Disk-averaged synthetic spectra of Mars

    CERN Document Server

    Tinetti, G; Fong, W; Meadows, V S; Snively, H; Velusamy, T; Crisp, David; Fong, William; Meadows, Victoria S.; Snively, Heather; Tinetti, Giovanna; Velusamy, Thangasamy

    2004-01-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and ESA Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earth-sized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of the planet Mars to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra as a function of spectral resolution and wavelength range, for both the proposed visible coronograph (TPF-C) and mid-infrared interferometer (TPF-I/Darwin) architectures. At the core of our model is a spectrum-resolving (line-by-line) atmospheric/surface radiative transfer model which uses observational data as input to generate a database of spatially-resolved synthetic spectra for a range of illumination conditions (phase angles) and viewing geometries. Results presented here include disk averaged synthetic spectra, light-cur...

  20. Binding sites for iodinated endothelin-1, endothelin-2 and endothelin-3 demonstrated on human uterine glandular epithelial cells by quantitative high-resolution autoradiography.

    Science.gov (United States)

    Davenport, A P; Cameron, I T; Smith, S K; Brown, M J

    1991-04-01

    Quantitative in-vitro receptor autoradiography has been used to localize and compare the anatomical distribution of binding sites for iodinated endothelins (ET-1, ET-2 and ET-3) in human uterus. Binding sites for the three iodinated isoforms had a similar gross anatomical distribution. The density of binding sites was significantly higher in the endometrium compared with the myometrium and greatest at the endometrial-myometrial junction. In cross-competition experiments, unlabelled ET-1, ET-2, ET-3, sarafotoxin S6b and mouse vasoactive intestinal contractor (1 mumol/l) competed for the binding sites of all the iodinated peptides suggesting that ETs may bind to the same receptor. However, preproendothelin(110-130) (endothelin-like peptide) or preproendothelin(124-130) and other non-endothelin vasoactive peptides tested as a concentration of 1 mumol/l did not compete. Micro-autoradiography revealed that high densities of iodinated ET-1, ET-2 and ET-3 binding sites were localized to glandular epithelial cells and blood vessels with lower levels in the myometrium and vascular smooth muscle, suggesting that these potent vasoactive and proliferative agents could play a role in the control of menstruation. PMID:2030325

  1. Helicobacter pylori CagA Suppresses Apoptosis through Activation of AKT in a Nontransformed Epithelial Cell Model of Glandular Acini Formation

    Directory of Open Access Journals (Sweden)

    Gabriela Vallejo-Flores

    2015-01-01

    Full Text Available H. pylori infection is the most important environmental risk to develop gastric cancer, mainly through its virulence factor CagA. In vitro models of CagA function have demonstrated a phosphoprotein activity targeting multiple cellular signaling pathways, while cagA transgenic mice develop carcinomas of the gastrointestinal tract, supporting oncogenic functions. However, it is still not completely clear how CagA alters cellular processes associated with carcinogenic events. In this study, we evaluated the capacity of H. pylori CagA positive and negative strains to alter nontransformed MCF-10A glandular acini formation. We found that CagA positive strains inhibited lumen formation arguing for an evasion of apoptosis activity of central acini cells. In agreement, CagA positive strains induced a cell survival activity that correlated with phosphorylation of AKT and of proapoptotic proteins BIM and BAD. Anoikis is a specific type of apoptosis characterized by AKT and BIM activation and it is the mechanism responsible for lumen formation of MCF-10A acini in vitro and mammary glands in vivo. Anoikis resistance is also a common mechanism of invading tumor cells. Our data support that CagA positive strains signaling function targets the AKT and BIM signaling pathway and this could contribute to its oncogenic activity through anoikis evasion.

  2. Development of an Expert System as a Diagnostic Support of Cervical Cancer in Atypical Glandular Cells, Based on Fuzzy Logics and Image Interpretation

    Directory of Open Access Journals (Sweden)

    Karem R. Domínguez Hernández

    2013-01-01

    Full Text Available Cervical cancer is the second largest cause of death among women worldwide. Nowadays, this disease is preventable and curable at low cost and low risk when an accurate diagnosis is done in due time, since it is the neoplasm with the highest prevention potential. This work describes the development of an expert system able to provide a diagnosis to cervical neoplasia (CN precursor injuries through the integration of fuzzy logics and image interpretation techniques. The key contribution of this research focuses on atypical cases, specifically on atypical glandular cells (AGC. The expert system consists of 3 phases: (1 risk diagnosis which consists of the interpretation of a patient’s clinical background and the risks for contracting CN according to specialists; (2 cytology images detection which consists of image interpretation (IM and the Bethesda system for cytology interpretation, and (3 determination of cancer precursor injuries which consists of in retrieving the information from the prior phases and integrating the expert system by means of a fuzzy logics (FL model. During the validation stage of the system, 21 already diagnosed cases were tested with a positive correlation in which 100% effectiveness was obtained. The main contribution of this work relies on the reduction of false positives and false negatives by providing a more accurate diagnosis for CN.

  3. Helicobacter pylori CagA Suppresses Apoptosis through Activation of AKT in a Nontransformed Epithelial Cell Model of Glandular Acini Formation

    Science.gov (United States)

    Vallejo-Flores, Gabriela; Torres, Javier; Sandoval-Montes, Claudia; Arévalo-Romero, Haruki; Meza, Isaura; Camorlinga-Ponce, Margarita; Torres-Morales, Julián; Chávez-Rueda, Adriana Karina; Legorreta-Haquet, María Victoria; Fuentes-Pananá, Ezequiel M.

    2015-01-01

    H. pylori infection is the most important environmental risk to develop gastric cancer, mainly through its virulence factor CagA. In vitro models of CagA function have demonstrated a phosphoprotein activity targeting multiple cellular signaling pathways, while cagA transgenic mice develop carcinomas of the gastrointestinal tract, supporting oncogenic functions. However, it is still not completely clear how CagA alters cellular processes associated with carcinogenic events. In this study, we evaluated the capacity of H. pylori CagA positive and negative strains to alter nontransformed MCF-10A glandular acini formation. We found that CagA positive strains inhibited lumen formation arguing for an evasion of apoptosis activity of central acini cells. In agreement, CagA positive strains induced a cell survival activity that correlated with phosphorylation of AKT and of proapoptotic proteins BIM and BAD. Anoikis is a specific type of apoptosis characterized by AKT and BIM activation and it is the mechanism responsible for lumen formation of MCF-10A acini in vitro and mammary glands in vivo. Anoikis resistance is also a common mechanism of invading tumor cells. Our data support that CagA positive strains signaling function targets the AKT and BIM signaling pathway and this could contribute to its oncogenic activity through anoikis evasion. PMID:26557697

  4. 子宫内膜浆乳癌及其癌前病变%Uterine papillary serous carcinoma & A putative precursor lesion of it-Endometrial glandular dysplasia

    Institute of Scientific and Technical Information of China (English)

    范文生; 于鹤; 宋磊; 陈乐真

    2009-01-01

    目的 研究子宫内膜浆乳癌(uterine papillary serpis carcinoma,UPSC)及其癌前病变-子宫内膜腺体异型增生(endometrial glandular dysplasia,EmGD)的临床病理特征及其诊治、预后.方法 对该院1993~2007年住院治疗的UPSC与EmGD病人11例进行回顾性分析.结果 主要临床表现为绝经后阴道流血,早期病人即可发生宫外病变,各期病人预后均差.结论 输卵管绝育术不能阻止宫外病变的发生,对早期病人应做分期手术并辅助放化疗,而晚期病人的治疗应强调个体化综合治疗.

  5. Effect of anatomical noise on the detectability of cone beam CT images with different slice direction, slice thickness, and volume glandular fraction.

    Science.gov (United States)

    Han, Minah; Park, Subok; Baek, Jongduk

    2016-08-22

    We investigate the effect of anatomical noise on the detectability of cone beam CT (CBCT) images with different slice directions, slice thicknesses, and volume glandular fractions (VGFs). Anatomical noise is generated using a power law spectrum of breast anatomy, and spherical objects with diameters from 1mm to 11mm are used as breast masses. CBCT projection images are simulated and reconstructed using the FDK algorithm. A channelized Hotelling observer (CHO) with Laguerre-Gauss (LG) channels is used to evaluate detectability for the signal-known-exactly (SKE) binary detection task. Detectability is calculated for various slice thicknesses in the transverse and longitudinal planes for 15%, 30% and 60% VGFs. The optimal slice thicknesses that maximize the detectability of the objects are determined. The results show that the β value increases as the slice thickness increases, but that thicker slices yield higher detectability in the transverse and longitudinal planes, except for the case of a 1mm diameter spherical object. It is also shown that the longitudinal plane with a 0.1mm slice thickness provides higher detectability than the transverse plane, despite its higher β value. With optimal slice thicknesses, the longitudinal plane exhibits better detectability for all VGFs and spherical objects. PMID:27557168

  6. Apoptotic wing degeneration and formation of an altruism-regulating glandular appendage (gemma) in the ponerine ant Diacamma sp. from Japan (Hymenoptera, Formicidae, Ponerinae).

    Science.gov (United States)

    Gotoh, A; Sameshima, S; Tsuji, K; Matsumoto, T; Miura, T

    2005-02-01

    We here show an example of morphological novelties, which have evolved from insect wings into the specific structures controlling social behaviour in an ant species. Most ant colonies consist of winged queen(s) and wingless workers. In the queenless ponerine ant Diacamma sp. from Japan, however, all female workers have a pair of small thoracic appendages, called "gemmae", which are homologous to the forewings and acts as an organ regulating altruism expression. Most workers, whose gemmae are clipped off by other colony members, become nonreproductive helpers, while only a single individual with complete gemmae becomes functionally reproductive. We examined histologically the development of gemmae, and compared it with that of functional wings in males. Female larvae had well-developed wing discs for both fore- and hindwings. At pupation, however, the wing discs started to evaginate and later degenerate. The hindwing discs completely degenerated, while the degeneration of forewing discs was incomplete, leading to the formation of gemmae. The degeneration process involved apoptotic cell death as confirmed by TUNEL assay. In addition, glandular cells differentiated from the epithelial cells of the forewing buds after completion of pupation. The mechanism of developmental transition from wing to gemma can be regarded as an evolutionary gain of new function, which can be seen in insect appendages and vertebrate limbs. PMID:15647944

  7. Ferutinin dose-dependent effects on uterus and mammary gland in ovariectomized rats.

    Science.gov (United States)

    Ferretti, Marzia; Cavani, Francesco; Manni, Paola; Carnevale, Gianluca; Bertoni, Laura; Zavatti, Manuela; Palumbo, Carla

    2014-08-01

    The present paper completes our recent study on the effects of phytoestrogen ferutinin in preventing osteoporosis and demonstrating the superior osteoprotective effect of a 2 mg/kg/day dose in ovariectomized (OVX) rats, compared to both estrogens and lower (0.5, 1 mg/kg/day) ferutinin doses. Morphological and morphometrical analyses were performed on the effects of different doses of ferutinin administrated for one month on uterus and on mammary gland of Sprague-Dawley OVX rats, evaluated in comparison with the results for estradiol benzoate. To verify whether ferutinin provides protection against uterine and breast cancer, estimations were made of both the amount of cell proliferation (by Ki-67), and the occurrence of apoptosis (by TUNEL), two processes that in unbalanced ratio form the basis for cancer onset. The results suggest that the effects of ferutinin are dose dependent and that a 2 mg/kg/day dose might offer a better protective action against the onset of both breast and uterine carcinoma compared to ferutinin in lower doses or estradiol benzoate, increasing cellular apoptosis in glandular epithelia. PMID:24510547

  8. Bayesian Model Averaging and Weighted Average Least Squares : Equivariance, Stability, and Numerical Issues

    NARCIS (Netherlands)

    De Luca, G.; Magnus, J.R.

    2011-01-01

    This article is concerned with the estimation of linear regression models with uncertainty about the choice of the explanatory variables. We introduce the Stata commands bma and wals which implement, respectively, the exact Bayesian Model Averaging (BMA) estimator and the Weighted Average Least Squa

  9. Phase-averaged transport for quasiperiodic Hamiltonians

    CERN Document Server

    Bellissard, J; Schulz-Baldes, H

    2002-01-01

    For a class of discrete quasi-periodic Schroedinger operators defined by covariant re- presentations of the rotation algebra, a lower bound on phase-averaged transport in terms of the multifractal dimensions of the density of states is proven. This result is established under a Diophantine condition on the incommensuration parameter. The relevant class of operators is distinguished by invariance with respect to symmetry automorphisms of the rotation algebra. It includes the critical Harper (almost-Mathieu) operator. As a by-product, a new solution of the frame problem associated with Weyl-Heisenberg-Gabor lattices of coherent states is given.

  10. Time-dependent angularly averaged inverse transport

    International Nuclear Information System (INIS)

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. Such measurement settings find applications in medical and geophysical imaging. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain

  11. Time-dependent angularly averaged inverse transport

    CERN Document Server

    Bal, Guillaume

    2009-01-01

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain.

  12. PROFILE OF HIRED FARMWORKERS, 1998 ANNUAL AVERAGES

    OpenAIRE

    Runyan, Jack L.

    2000-01-01

    An average of 875,000 persons 15 years of age and older did hired farmwork each week as their primary job in 1998. An additional 63,000 people did hired farmwork each week as their secondary job. Hired farmworkers were more likely than the typical U.S. wage and salary worker to be male, Hispanic, younger, less educated, never married, and not U.S. citizens. The West (42 percent) and South (31.4 percent) census regions accounted for almost three-fourths of the hired farmworkers. The rate of un...

  13. The average free volume model for liquids

    CERN Document Server

    Yu, Yang

    2014-01-01

    In this work, the molar volume thermal expansion coefficient of 59 room temperature ionic liquids is compared with their van der Waals volume Vw. Regular correlation can be discerned between the two quantities. An average free volume model, that considers the particles as hard core with attractive force, is proposed to explain the correlation in this study. A combination between free volume and Lennard-Jones potential is applied to explain the physical phenomena of liquids. Some typical simple liquids (inorganic, organic, metallic and salt) are introduced to verify this hypothesis. Good agreement from the theory prediction and experimental data can be obtained.

  14. Fluctuations of wavefunctions about their classical average

    Energy Technology Data Exchange (ETDEWEB)

    Benet, L [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico); Flores, J [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico); Hernandez-Saldana, H [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico); Izrailev, F M [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico); Leyvraz, F [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico); Seligman, T H [Centro Internacional de Ciencias, Ciudad Universitaria, Chamilpa, Cuernavaca (Mexico)

    2003-02-07

    Quantum-classical correspondence for the average shape of eigenfunctions and the local spectral density of states are well-known facts. In this paper, the fluctuations of the quantum wavefunctions around the classical value are discussed. A simple random matrix model leads to a Gaussian distribution of the amplitudes whose width is determined by the classical shape of the eigenfunction. To compare this prediction with numerical calculations in chaotic models of coupled quartic oscillators, we develop a rescaling method for the components. The expectations are broadly confirmed, but deviations due to scars are observed. This effect is much reduced when both Hamiltonians have chaotic dynamics.

  15. Fluctuations of wavefunctions about their classical average

    CERN Document Server

    Bénet, L; Hernandez-Saldana, H; Izrailev, F M; Leyvraz, F; Seligman, T H

    2003-01-01

    Quantum-classical correspondence for the average shape of eigenfunctions and the local spectral density of states are well-known facts. In this paper, the fluctuations of the quantum wavefunctions around the classical value are discussed. A simple random matrix model leads to a Gaussian distribution of the amplitudes whose width is determined by the classical shape of the eigenfunction. To compare this prediction with numerical calculations in chaotic models of coupled quartic oscillators, we develop a rescaling method for the components. The expectations are broadly confirmed, but deviations due to scars are observed. This effect is much reduced when both Hamiltonians have chaotic dynamics.

  16. Sparsity averaging for radio-interferometric imaging

    CERN Document Server

    Carrillo, Rafael E; Wiaux, Yves

    2014-01-01

    We propose a novel regularization method for compressive imaging in the context of the compressed sensing (CS) theory with coherent and redundant dictionaries. Natural images are often complicated and several types of structures can be present at once. It is well known that piecewise smooth images exhibit gradient sparsity, and that images with extended structures are better encapsulated in wavelet frames. Therefore, we here conjecture that promoting average sparsity or compressibility over multiple frames rather than single frames is an extremely powerful regularization prior.

  17. Radiological Dose Calculations for Fusion Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Abbott; Lee C. Cadwallader; David A. Petti

    2003-04-01

    This report summarizes the results and rationale for radiological dose calculations for the maximally exposed individual during fusion accident conditions. Early doses per unit activity (Sieverts per TeraBecquerel) are given for 535 magnetic fusion isotopes of interest for several release scenarios. These data can be used for accident assessment calculations to determine if the accident consequences exceed Nuclear Regulatory Commission and Department of Energy evaluation guides. A generalized yearly dose estimate for routine releases, based on 1 Terabecquerel unit releases per radionuclide, has also been performed using averaged site parameters and assumed populations. These routine release data are useful for assessing designs against US Environmental Protection Agency yearly release limits.

  18. 黏蛋白与宫颈腺上皮肿瘤性病变关系的研究进展%Research Progress in Relationship Between Mucin and Neoplastic Glandular Epithelia of Uterine Cervix

    Institute of Scientific and Technical Information of China (English)

    秦玲; 石岩; 吴丽华; 娄阁; 李娟; 刘瑾; 焦宇飞

    2013-01-01

    The expression of mucin (MUC) in human cervical tissues and the relationship between MUC and cervical glandular neoplastic lesions are reviewed and investigated,which indicates that abnormal expression of MUC in cervical tumors might be a marker to differentiate benign,premalignant and malignant lesions.MUC might play an important role in early diagnosis and prognosis for the tumors.This article reviews biological function of MUC,expression in cervical glandular neoplastic lesions and the relationship between MUC and cervical glandular neoplastic lesions.%回顾人类宫颈组织的黏蛋白表达情况,及黏蛋白与宫颈腺上皮肿瘤性病变发生、发展的关系,提示黏蛋白在宫颈肿瘤的异常表达可以作为鉴别宫颈腺上皮良性病变、癌前与恶性病变的标志物,这对肿瘤的早期诊断及预后具有重要的意义.全文就黏蛋白的生物学功能、在宫颈腺上皮肿瘤性病变中的表达,及其与宫颈腺上皮肿瘤性病变关系的研究进展作一综述.

  19. MACHINE PROTECTION FOR HIGH AVERAGE CURRENT LINACS

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Kevin; Allison, Trent; Evans, Richard; Coleman, James; Grippo, Albert

    2003-05-01

    A fully integrated Machine Protection System (MPS) is critical to efficient commissioning and safe operation of all high current accelerators. The Jefferson Lab FEL [1,2] has multiple electron beam paths and many different types of diagnostic insertion devices. The MPS [3] needs to monitor both the status of these devices and the magnet settings which define the beam path. The matrix of these devices and beam paths are programmed into gate arrays, the output of the matrix is an allowable maximum average power limit. This power limit is enforced by the drive laser for the photocathode gun. The Beam Loss Monitors (BLMs), RF status, and laser safety system status are also inputs to the control matrix. There are 8 Machine Modes (electron path) and 8 Beam Modes (average power limits) that define the safe operating limits for the FEL. Combinations outside of this matrix are unsafe and the beam is inhibited. The power limits range from no beam to 2 megawatts of electron beam power.

  20. Trajectory averaging for stochastic approximation MCMC algorithms

    KAUST Repository

    Liang, Faming

    2010-10-01

    The subject of stochastic approximation was founded by Robbins and Monro [Ann. Math. Statist. 22 (1951) 400-407]. After five decades of continual development, it has developed into an important area in systems control and optimization, and it has also served as a prototype for the development of adaptive algorithms for on-line estimation and control of stochastic systems. Recently, it has been used in statistics with Markov chain Monte Carlo for solving maximum likelihood estimation problems and for general simulation and optimizations. In this paper, we first show that the trajectory averaging estimator is asymptotically efficient for the stochastic approximation MCMC (SAMCMC) algorithm under mild conditions, and then apply this result to the stochastic approximation Monte Carlo algorithm [Liang, Liu and Carroll J. Amer. Statist. Assoc. 102 (2007) 305-320]. The application of the trajectory averaging estimator to other stochastic approximationMCMC algorithms, for example, a stochastic approximation MLE algorithm for missing data problems, is also considered in the paper. © Institute of Mathematical Statistics, 2010.

  1. Rademacher averages on noncommutative symmetric spaces

    CERN Document Server

    Merdy, Christian Le

    2008-01-01

    Let E be a separable (or the dual of a separable) symmetric function space, let M be a semifinite von Neumann algebra and let E(M) be the associated noncommutative function space. Let $(\\epsilon_k)_k$ be a Rademacher sequence, on some probability space $\\Omega$. For finite sequences $(x_k)_k of E(M), we consider the Rademacher averages $\\sum_k \\epsilon_k\\otimes x_k$ as elements of the noncommutative function space $E(L^\\infty(\\Omega)\\otimes M)$ and study estimates for their norms $\\Vert \\sum_k \\epsilon_k \\otimes x_k\\Vert_E$ calculated in that space. We establish general Khintchine type inequalities in this context. Then we show that if E is 2-concave, the latter norm is equivalent to the infimum of $\\Vert (\\sum y_k^*y_k)^{{1/2}}\\Vert + \\Vert (\\sum z_k z_k^*)^{{1/2}}\\Vert$ over all $y_k,z_k$ in E(M) such that $x_k=y_k+z_k$ for any k. Dual estimates are given when E is 2-convex and has a non trivial upper Boyd index. We also study Rademacher averages for doubly indexed families of E(M).

  2. Motional averaging in a superconducting qubit.

    Science.gov (United States)

    Li, Jian; Silveri, M P; Kumar, K S; Pirkkalainen, J-M; Vepsäläinen, A; Chien, W C; Tuorila, J; Sillanpää, M A; Hakonen, P J; Thuneberg, E V; Paraoanu, G S

    2013-01-01

    Superconducting circuits with Josephson junctions are promising candidates for developing future quantum technologies. Of particular interest is to use these circuits to study effects that typically occur in complex condensed-matter systems. Here we employ a superconducting quantum bit--a transmon--to perform an analogue simulation of motional averaging, a phenomenon initially observed in nuclear magnetic resonance spectroscopy. By modulating the flux bias of a transmon with controllable pseudo-random telegraph noise we create a stochastic jump of its energy level separation between two discrete values. When the jumping is faster than a dynamical threshold set by the frequency displacement of the levels, the initially separate spectral lines merge into a single, narrow, motional-averaged line. With sinusoidal modulation a complex pattern of additional sidebands is observed. We show that the modulated system remains quantum coherent, with modified transition frequencies, Rabi couplings, and dephasing rates. These results represent the first steps towards more advanced quantum simulations using artificial atoms. PMID:23361011

  3. Intensity contrast of the average supergranule

    CERN Document Server

    Langfellner, J; Gizon, L

    2016-01-01

    While the velocity fluctuations of supergranulation dominate the spectrum of solar convection at the solar surface, very little is known about the fluctuations in other physical quantities like temperature or density at supergranulation scale. Using SDO/HMI observations, we characterize the intensity contrast of solar supergranulation at the solar surface. We identify the positions of ${\\sim}10^4$ outflow and inflow regions at supergranulation scales, from which we construct average flow maps and co-aligned intensity and magnetic field maps. In the average outflow center, the maximum intensity contrast is $(7.8\\pm0.6)\\times10^{-4}$ (there is no corresponding feature in the line-of-sight magnetic field). This corresponds to a temperature perturbation of about $1.1\\pm0.1$ K, in agreement with previous studies. We discover an east-west anisotropy, with a slightly deeper intensity minimum east of the outflow center. The evolution is asymmetric in time: the intensity excess is larger 8 hours before the reference t...

  4. Average prime-pair counting formula

    Science.gov (United States)

    Korevaar, Jaap; Riele, Herman Te

    2010-04-01

    Taking r>0 , let π_{2r}(x) denote the number of prime pairs (p, p+2r) with p≤ x . The prime-pair conjecture of Hardy and Littlewood (1923) asserts that π_{2r}(x)˜ 2C_{2r} {li}_2(x) with an explicit constant C_{2r}>0 . There seems to be no good conjecture for the remainders ω_{2r}(x)=π_{2r}(x)- 2C_{2r} {li}_2(x) that corresponds to Riemann's formula for π(x)-{li}(x) . However, there is a heuristic approximate formula for averages of the remainders ω_{2r}(x) which is supported by numerical results.

  5. Averaged Null Energy Condition from Causality

    CERN Document Server

    Hartman, Thomas; Tajdini, Amirhossein

    2016-01-01

    Unitary, Lorentz-invariant quantum field theories in flat spacetime obey microcausality: commutators vanish at spacelike separation. For interacting theories in more than two dimensions, we show that this implies that the averaged null energy, $\\int du T_{uu}$, must be positive. This non-local operator appears in the operator product expansion of local operators in the lightcone limit, and therefore contributes to $n$-point functions. We derive a sum rule that isolates this contribution and is manifestly positive. The argument also applies to certain higher spin operators other than the stress tensor, generating an infinite family of new constraints of the form $\\int du X_{uuu\\cdots u} \\geq 0$. These lead to new inequalities for the coupling constants of spinning operators in conformal field theory, which include as special cases (but are generally stronger than) the existing constraints from the lightcone bootstrap, deep inelastic scattering, conformal collider methods, and relative entropy. We also comment ...

  6. Hedge algorithm and Dual Averaging schemes

    CERN Document Server

    Baes, Michel

    2011-01-01

    We show that the Hedge algorithm, a method that is widely used in Machine Learning, can be interpreted as a particular instance of Dual Averaging schemes, which have recently been introduced by Nesterov for regret minimization. Based on this interpretation, we establish three alternative methods of the Hedge algorithm: one in the form of the original method, but with optimal parameters, one that requires less a priori information, and one that is better adapted to the context of the Hedge algorithm. All our modified methods have convergence results that are better or at least as good as the performance guarantees of the vanilla method. In numerical experiments, our methods significantly outperform the original scheme.

  7. The Lang-Trotter Conjecture on Average

    OpenAIRE

    Baier, Stephan

    2006-01-01

    For an elliptic curve $E$ over $\\ratq$ and an integer $r$ let $\\pi_E^r(x)$ be the number of primes $p\\le x$ of good reduction such that the trace of the Frobenius morphism of $E/\\fie_p$ equals $r$. We consider the quantity $\\pi_E^r(x)$ on average over certain sets of elliptic curves. More in particular, we establish the following: If $A,B>x^{1/2+\\epsilon}$ and $AB>x^{3/2+\\epsilon}$, then the arithmetic mean of $\\pi_E^r(x)$ over all elliptic curves $E$ : $y^2=x^3+ax+b$ with $a,b\\in \\intz$, $|a...

  8. Averaging lifetimes for B hadron species

    International Nuclear Information System (INIS)

    The measurement of the lifetimes of the individual B species are of great interest. Many of these measurements are well below the 10% level of precision. However, in order to reach the precision necessary to test the current theoretical predictions, the results from different experiments need to be averaged together. Therefore, the relevant systematic uncertainties of each measurement need to be well defined in order to understand the correlations between the results from different experiments. In this paper we discuss the dominant sources of systematic errors which lead to correlations between the different measurements. We point out problems connected with the conventional approach of combining lifetime data and discuss methods which overcome these problems. (orig.)

  9. Scaling crossover for the average avalanche shape

    Science.gov (United States)

    Papanikolaou, Stefanos; Bohn, Felipe; Sommer, Rubem L.; Durin, Gianfranco; Zapperi, Stefano; Sethna, James P.

    2010-03-01

    Universality and the renormalization group claim to predict all behavior on long length and time scales asymptotically close to critical points. In practice, large simulations and heroic experiments have been needed to unambiguously test and measure the critical exponents and scaling functions. We announce here the measurement and prediction of universal corrections to scaling, applied to the temporal average shape of Barkhausen noise avalanches. We bypass the confounding factors of time-retarded interactions (eddy currents) by measuring thin permalloy films, and bypass thresholding effects and amplifier distortions by applying Wiener deconvolution. We show experimental shapes that are approximately symmetric, and measure the leading corrections to scaling. We solve a mean-field theory for the magnetization dynamics and calculate the relevant demagnetizing-field correction to scaling, showing qualitative agreement with the experiment. In this way, we move toward a quantitative theory useful at smaller time and length scales and farther from the critical point.

  10. Average transverse momentum quantities approaching the lightfront

    CERN Document Server

    Boer, Daniel

    2014-01-01

    In this contribution to Light Cone 2014, three average transverse momentum quantities are discussed: the Sivers shift, the dijet imbalance, and the $p_T$ broadening. The definitions of these quantities involve integrals over all transverse momenta that are overly sensitive to the region of large transverse momenta, which conveys little information about the transverse momentum distributions of quarks and gluons inside hadrons. TMD factorization naturally suggests alternative definitions of such integrated quantities, using Bessel-weighting and rapidity cut-offs, with the conventional definitions as limiting cases. The regularized quantities are given in terms of integrals over the TMDs of interest that are well-defined and moreover have the advantage of being amenable to lattice evaluations.

  11. Bivariate phase-rectified signal averaging

    CERN Document Server

    Schumann, Aicko Y; Bauer, Axel; Schmidt, Georg

    2008-01-01

    Phase-Rectified Signal Averaging (PRSA) was shown to be a powerful tool for the study of quasi-periodic oscillations and nonlinear effects in non-stationary signals. Here we present a bivariate PRSA technique for the study of the inter-relationship between two simultaneous data recordings. Its performance is compared with traditional cross-correlation analysis, which, however, does not work well for non-stationary data and cannot distinguish the coupling directions in complex nonlinear situations. We show that bivariate PRSA allows the analysis of events in one signal at times where the other signal is in a certain phase or state; it is stable in the presence of noise and impassible to non-stationarities.

  12. Asymmetric network connectivity using weighted harmonic averages

    Science.gov (United States)

    Morrison, Greg; Mahadevan, L.

    2011-02-01

    We propose a non-metric measure of the "closeness" felt between two nodes in an undirected, weighted graph using a simple weighted harmonic average of connectivity, that is a real-valued Generalized Erdös Number (GEN). While our measure is developed with a collaborative network in mind, the approach can be of use in a variety of artificial and real-world networks. We are able to distinguish between network topologies that standard distance metrics view as identical, and use our measure to study some simple analytically tractable networks. We show how this might be used to look at asymmetry in authorship networks such as those that inspired the integer Erdös numbers in mathematical coauthorships. We also show the utility of our approach to devise a ratings scheme that we apply to the data from the NetFlix prize, and find a significant improvement using our method over a baseline.

  13. The balanced survivor average causal effect.

    Science.gov (United States)

    Greene, Tom; Joffe, Marshall; Hu, Bo; Li, Liang; Boucher, Ken

    2013-01-01

    Statistical analysis of longitudinal outcomes is often complicated by the absence of observable values in patients who die prior to their scheduled measurement. In such cases, the longitudinal data are said to be "truncated by death" to emphasize that the longitudinal measurements are not simply missing, but are undefined after death. Recently, the truncation by death problem has been investigated using the framework of principal stratification to define the target estimand as the survivor average causal effect (SACE), which in the context of a two-group randomized clinical trial is the mean difference in the longitudinal outcome between the treatment and control groups for the principal stratum of always-survivors. The SACE is not identified without untestable assumptions. These assumptions have often been formulated in terms of a monotonicity constraint requiring that the treatment does not reduce survival in any patient, in conjunction with assumed values for mean differences in the longitudinal outcome between certain principal strata. In this paper, we introduce an alternative estimand, the balanced-SACE, which is defined as the average causal effect on the longitudinal outcome in a particular subset of the always-survivors that is balanced with respect to the potential survival times under the treatment and control. We propose a simple estimator of the balanced-SACE that compares the longitudinal outcomes between equivalent fractions of the longest surviving patients between the treatment and control groups and does not require a monotonicity assumption. We provide expressions for the large sample bias of the estimator, along with sensitivity analyses and strategies to minimize this bias. We consider statistical inference under a bootstrap resampling procedure. PMID:23658214

  14. Morphogenesis and Developmental Law of Glandular Hairs of Elsholtzia stauntoni Benth%木香薷腺毛形态结构发生发育规律的研究

    Institute of Scientific and Technical Information of China (English)

    朱广龙; 赵挺; 康冬冬; 魏学智

    2011-01-01

    采用常规石蜡切片法及扫描电镜技术对木香薷(Elsholtzia stauntoni Benth)腺毛发生发育及其规律进行了研究.结果表明:木香薷表皮上主要有两种表皮毛:无分泌细胞的表皮毛与有分泌细胞的腺毛.前者包括单细胞乳头状毛、2~3细胞管状毛、分枝状毛及多细胞管状毛;后者包括头状腺毛与盾状腺毛.成熟头状腺毛头部由1、2或4个分泌细胞构成,头部呈圆球形或半圆球形;成熟盾状腺毛头部由8~12个分泌细胞构成,分泌细胞横向扩展形成盾状头部.木香薷腺毛主要在茎端幼叶处大量发生,从茎端第一对幼叶处开始产生;从幼叶期到成熟期均有腺毛发生,大部分腺毛在幼叶期发生发育,只有极少部分在叶的成熟期进行发生发育.%The paraffin sectionning and scanning electron microscopy ( SEM ) were used to study the morphogenesis and law of development of Elsholtzia stauntoni Benth. The results showed that glandular hairs of E. Stauntoni Benth has two main types of trichomes: trichomes without secreting cells and trichomes with secreting cells. The former include: single-cell mastoid trichomes ,2-3 cells tubular trichomes ,2-3 cells ramose trichomes and multicellular tubular trichomes. The latter include peltate and capitate hairs. The mature capitate glandular hairs comprise one, two or four secretory cells and its head is spherical or half spherical. The head of mature peltate glandular hairs comprises eight to twelve secretory cells and the secretory cells expand to a shield-shaped head. The glandular hairs of E. Stauntoni Benth mainly occur gready on younger leaves and start to generate from the first pair of younger leaves of stem apex. The morphogenesis of new glandular hairs can be observed to occur from young leaves stage to mature stage, however, only a relatively small amount occurs in maturation stage.

  15. 乳腺组织瓣联合真皮帽悬吊术矫正轻中度乳房下垂%Correction of mild and moderate breast ptosis with glandular flap combined with dermal flap suspension

    Institute of Scientific and Technical Information of China (English)

    熊凌云; 孙家明; 郭能强; 杨杰

    2011-01-01

    目的 探讨乳腺组织瓣旋转联合真皮帽悬吊的垂乳上提技术矫正轻中度乳房下垂的临床效果.方法 根据乳房下垂程度设计形成真皮帽后,分离乳房皮肤和腺体,于乳腺外上方行部分腺体切除或直接纵行切开腺体,并同时形成外侧腺体瓣,掀起腺体瓣向内侧旋转固定,缩小乳房基底,再行真皮帽上提固定和乳房塑形.结果 2006年3月至2010年3月,于临床应用46例,术后效果满意,其中2例出现单侧血肿,无其他严重并发症.对40例患者随访6个月至4年,乳房外形满意,无继发下垂、乳房扁平、乳头乳晕感觉障碍等并发症.结论 乳腺组织瓣旋转联合真皮帽悬吊垂乳上提术可商塑造饱满、坚挺的乳房,术后瘢痕不明显,远期效果满意.%Objective To investigate the therapeutic effect of glandular flap combined with dermal flap suspension for correction of mild and moderate breast ptosis. Methods The dermal flap was formed according to the breast ptosis and dissection was performed between the skin and gland. The superior-lateral gland was partially resected or cutted vertically only to form the lateral glandular flap. Then the glandular flap was rotated medially and fixed to shrink the glandular base area. Then the breast was up-positioned and fixed with dermal flap to remodel the breast shape. Results From Mar. 2006 to Mar. 2010, 46 cases were treated with satisfactory result. There was no severe complication, except for 2 cases of unilateral hematoma. 40 cases were followed up for 6 months to 4 years with good breast shape. No secondary ptosis,breast flatten and NAC sensation disorder was happened. Conclusions Glandular flap combined with dermal flap suspension is a good method for mild and moderate breast ptosis with reliable long-term results.The breasts have busty appearance and good projection with inconspicious scar.

  16. Establishment of a long-term three-dimensional primary culture of mouse glandular stomach epithelial cells within the stem cell niche

    International Nuclear Information System (INIS)

    Highlights: ► We established a 3D culture system to allow long-term culture of stomach cells. ► In this culture system, gastric epithelial cells grew for about 3 months. ► The cultured cells differentiated into multi-units of the stomach. ► This culture method should be useful for elucidating the cause of gastric diseases. -- Abstract: Compared to the small intestine and colon, little is known about stem cells in the stomach because of a lack of specific stem cell markers and an in vitro system that allows long-term culture. Here we describe a long-term three-dimensional (3D) primary gastric culture system within the stem cell niche. Glandular stomach cells from neonatal mice cultured in collagen gel yielded expanding sphere-like structures for 3 months. The wall of the gastrospheres consisted of a highly polarized epithelial monolayer with an outer lining of myofibroblasts. The epithelial cells showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm as well as expression of MUC5AC, indicating differentiation into gastric surface mucous cells. These cells demonstrated the features of fully differentiated gastric surface mucous cells such as microvilli, junctional complexes, and glycogen and secretory granules. Fewer than 1% of cultured epithelial cells differentiated into enteroendocrine cells. Active proliferation of the epithelial cells and many apoptotic cells in the inner lumen revealed the rapid cell turnover in gastrospheres in vitro. This method enables us to investigate the role of signaling between cell–cell and epithelial–mesenchymal interactions in an environment that is extremely similar to the in vivo environment

  17. Establishment of a long-term three-dimensional primary culture of mouse glandular stomach epithelial cells within the stem cell niche

    Energy Technology Data Exchange (ETDEWEB)

    Katano, Takahito [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Ootani, Akifumi [Department of Gastroenterology and GI Endoscopy Center, Shin-Kokura Hospital, Federation of National Public Service Personnel Mutual Aid Associations, 1-3-1 Kanada, Kokurakita-ku, Kitakyushu 803-0816 (Japan); Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Mizoshita, Tsutomu, E-mail: tmizoshi@med.nagoya-cu.ac.jp [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Tanida, Satoshi; Tsukamoto, Hironobu; Ozeki, Keiji; Ebi, Masahide; Mori, Yoshinori; Kataoka, Hiromi; Kamiya, Takeshi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan); Toda, Shuji [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Joh, Takashi [Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601 (Japan)

    2013-03-22

    Highlights: ► We established a 3D culture system to allow long-term culture of stomach cells. ► In this culture system, gastric epithelial cells grew for about 3 months. ► The cultured cells differentiated into multi-units of the stomach. ► This culture method should be useful for elucidating the cause of gastric diseases. -- Abstract: Compared to the small intestine and colon, little is known about stem cells in the stomach because of a lack of specific stem cell markers and an in vitro system that allows long-term culture. Here we describe a long-term three-dimensional (3D) primary gastric culture system within the stem cell niche. Glandular stomach cells from neonatal mice cultured in collagen gel yielded expanding sphere-like structures for 3 months. The wall of the gastrospheres consisted of a highly polarized epithelial monolayer with an outer lining of myofibroblasts. The epithelial cells showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm as well as expression of MUC5AC, indicating differentiation into gastric surface mucous cells. These cells demonstrated the features of fully differentiated gastric surface mucous cells such as microvilli, junctional complexes, and glycogen and secretory granules. Fewer than 1% of cultured epithelial cells differentiated into enteroendocrine cells. Active proliferation of the epithelial cells and many apoptotic cells in the inner lumen revealed the rapid cell turnover in gastrospheres in vitro. This method enables us to investigate the role of signaling between cell–cell and epithelial–mesenchymal interactions in an environment that is extremely similar to the in vivo environment.

  18. Morphological Comparison on the Leaf Epidermis and Glandular Hairs in 11 Medical Plants from Labiatae%11种唇形科药用植物叶表及腺毛的形态比较

    Institute of Scientific and Technical Information of China (English)

    胡凤莲

    2009-01-01

    [目的]为利用叶表面和腺毛形态特征区分唇形科植物奠定基础.[方法] 选取11种常见的唇形科药用植物,利用扫描电镜观察比较其叶表面及腺毛的形态特征.[结果] 叶表皮细胞表面覆有一层厚度适中的角质层,有不同程度的条状纹理.下表皮细胞小于上表皮细胞.叶表面有气孔、腺毛和非腺毛,且下表面的气孔、腺毛和非腺毛比上表面多.气孔呈圆形至椭圆形,副卫细胞表面的角质层常凸起呈苞片状,气孔周围有条状纹理,且常以气孔为中心呈放射状.非腺毛分枝或不分枝;基部的条状角质纹理呈放射状或纵横交错.腺毛呈盾状或头状,腺毛的形态、大小、密度和头细胞的数目有明显的差别.[结论] 该研究为唇形科药用植物的分类和利用提供了新的依据.%[Objective]The purpose of the study was to lay a foundation for distinguishing labiatae plants on the basis of the morphological characters of leaf epidermis and glandular hairs.[Method] Eleven familiar medial plants from labiatae were selected, their morphological characters of leaf epidermis and glandular hairs were observed by scanning electron microscope and compared.[Result] There was a moderately thick cuticle covering the surface of leaf epidermis cells and it had striped texture to different degrees. The lower epidermis cells were smaller than the upper epidermis cells. There were stomata, glandular hairs and non-glandular hairs on leaf epidermis and that on the lower leaf epidermis were more than that on the upper leaf epidermis. The stomata varied from circular to ellipse, the cuticle covering the surface of subsidiary cell often bulged to be bracteal. There was striped texture around stomata and it was often radial with stomata as center. There were branches on non-glandular hairs or not and the striped cuticle textures on their bases were radial or crossing. The glandular hairs were peltate or capitate and the shape, sizes

  19. Control of average spacing of OMCVD grown gold nanoparticles

    Science.gov (United States)

    Rezaee, Asad

    using surface characterization methods such as contact angle measurements, ellipsometry, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), Rutherford backscattering spectroscopy (RBS), UV-Visible spectroscopy, and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). Keywords: Absorption, Array, Average Spacing, Binary Mixture, Density, Deposition, Dose, Fm, Gold Nanoparticle, Growth, Ion Irradiation, LSPR, Nanolithography, Nearest Neighbour Distance, OMCVD, Optical Response, OTS, Polarization, Refilling, Resist, SAM, Self-assembly, SEM Image Analysis, Sensing, Surface, Thin Film, Transparent Substrate.

  20. SU-E-T-280: Reconstructed Rectal Wall Dose Map-Based Verification of Rectal Dose Sparing Effect According to Rectum Definition Methods and Dose Perturbation by Air Cavity in Endo-Rectal Balloon

    International Nuclear Information System (INIS)

    Purpose: Dosimetric effect and discrepancy according to the rectum definition methods and dose perturbation by air cavity in an endo-rectal balloon (ERB) were verified using rectal-wall (Rwall) dose maps considering systematic errors in dose optimization and calculation accuracy in intensity-modulated radiation treatment (IMRT) for prostate cancer patients. Methods: When the inflated ERB having average diameter of 4.5 cm and air volume of 100 cc is used for patient, Rwall doses were predicted by pencil-beam convolution (PBC), anisotropic analytic algorithm (AAA), and AcurosXB (AXB) with material assignment function. The errors of dose optimization and calculation by separating air cavity from the whole rectum (Rwhole) were verified with measured rectal doses. The Rwall doses affected by the dose perturbation of air cavity were evaluated using a featured rectal phantom allowing insert of rolled-up gafchromic films and glass rod detectors placed along the rectum perimeter. Inner and outer Rwall doses were verified with reconstructed predicted rectal wall dose maps. Dose errors and extent at dose levels were evaluated with estimated rectal toxicity. Results: While AXB showed insignificant difference of target dose coverage, Rwall doses underestimated by up to 20% in dose optimization for the Rwhole than Rwall at all dose range except for the maximum dose. As dose optimization for Rwall was applied, the Rwall doses presented dose error less than 3% between dose calculation algorithm except for overestimation of maximum rectal dose up to 5% in PBC. Dose optimization for Rwhole caused dose difference of Rwall especially at intermediate doses. Conclusion: Dose optimization for Rwall could be suggested for more accurate prediction of rectal wall dose prediction and dose perturbation effect by air cavity in IMRT for prostate cancer. This research was supported by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea

  1. Dose profile in computed tomography chest scan

    International Nuclear Information System (INIS)

    For the optimization of the patient dose in computed tomography (CT), the Brazilian legislation only established the diagnostic reference levels (DRL's) in terms of Multiple Scan Average Dose (MSAD) in a typical adult as a parameter of quality control of CT scanners. Conformity to the DRL's can be verified by measuring the dose distribution in CT scans and MSAD determination. An analysis of the quality of CT scans of the metropolitan region of Belo Horizonte is necessary by conducting pertinent tests to the study that are presented in the ANVISA (National Agency of Sanitary Vigilance) Guide. The purpose of this study is to investigate, in a chest scan, the variation of dose in CT. To measure the dose profile are used lithium fluoride thermoluminescent dosimeters (TLD-100 Rod) distributed in cylinders positioned in peripheral and central regions of a phantom of polymethylmethacrylate (PMMA). The data obtained allow us to observe the variation of the dose profile inside the phantom. The peripheral region shows higher dose values than the central region. The longitudinal variation can be observed and the maximum dose was recorded at the edges of the phantom (41,58±5,10) mGy at the midpoint of the longitudinal axis. The results will contribute to disseminate the proper procedure and optimize the dosimetry and the tests of quality control in CT, as well as make a critical analysis of the DRL's. (author)

  2. Comparison of standard-dose and low-dose scanning with 16-MDCT for urinary calculi

    International Nuclear Information System (INIS)

    Objective: To explore the feasibility to diagnose ureterolithiasis by 16-multidetector spiral computed tomography (16-MDCT) at different low doses based on body mass index (BMI). Methods: A total of one hundred patients from 2009 Sep to 2010 Feb suspected of ureterolithiasis were randomly divided into 2 equal groups undergoing 16-MDCT at standard-dose (120 kV, 240 mA) or low dose (120, 80, and 50 mA, respectively) based on the body mass index (BMI). Taking the clinical diagnosis as the standard, the sensitivity level, specificity level, and positive predictive value of these groups were compared. Results: The dose length product (DLP) of the low-dose CT group and the standard dose group were (726±45.67) and (251±73.87) mGy·cm, respectively. There was significant average CT dose index (CTDIvol ) were 18.95 and 6.65 mGy, respectively. There was significant difference between the two groups (t=31.78, P<0.01). The sensitivity level, specificity level, and positive predictive value of the low-dose group were 97.1% , 94.0%, and 94.3%, respectively, all not significantly different from those of the standard-dose groups (97.3%, 96.0%, and 97.3%, respectively, P>0.05). Conclusions: It is feasible to diagnose ureterolithiasis by low-dose 16-MDCT based on BMI with the obtained image quality meeting the clinical diagnostic requirements. (authors)

  3. A new approach for Bayesian model averaging

    Institute of Scientific and Technical Information of China (English)

    TIAN XiangJun; XIE ZhengHui; WANG AiHui; YANG XiaoChun

    2012-01-01

    Bayesian model averaging (BMA) is a recently proposed statistical method for calibrating forecast ensembles from numerical weather models.However,successful implementation of BMA requires accurate estimates of the weights and variances of the individual competing models in the ensemble.Two methods,namely the Expectation-Maximization (EM) and the Markov Chain Monte Carlo (MCMC) algorithms,are widely used for BMA model training.Both methods have their own respective strengths and weaknesses.In this paper,we first modify the BMA log-likelihood function with the aim of removing the additional limitation that requires that the BMA weights add to one,and then use a limited memory quasi-Newtonian algorithm for solving the nonlinear optimization problem,thereby formulating a new approach for BMA (referred to as BMA-BFGS).Several groups of multi-model soil moisture simulation experiments from three land surface models show that the performance of BMA-BFGS is similar to the MCMC method in terms of simulation accuracy,and that both are superior to the EM algorithm.On the other hand,the computational cost of the BMA-BFGS algorithm is substantially less than for MCMC and is almost equivalent to that for EM.

  4. Calculating Free Energies Using Average Force

    Science.gov (United States)

    Darve, Eric; Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    A new, general formula that connects the derivatives of the free energy along the selected, generalized coordinates of the system with the instantaneous force acting on these coordinates is derived. The instantaneous force is defined as the force acting on the coordinate of interest so that when it is subtracted from the equations of motion the acceleration along this coordinate is zero. The formula applies to simulations in which the selected coordinates are either unconstrained or constrained to fixed values. It is shown that in the latter case the formula reduces to the expression previously derived by den Otter and Briels. If simulations are carried out without constraining the coordinates of interest, the formula leads to a new method for calculating the free energy changes along these coordinates. This method is tested in two examples - rotation around the C-C bond of 1,2-dichloroethane immersed in water and transfer of fluoromethane across the water-hexane interface. The calculated free energies are compared with those obtained by two commonly used methods. One of them relies on determining the probability density function of finding the system at different values of the selected coordinate and the other requires calculating the average force at discrete locations along this coordinate in a series of constrained simulations. The free energies calculated by these three methods are in excellent agreement. The relative advantages of each method are discussed.

  5. Industrial Applications of High Average Power FELS

    CERN Document Server

    Shinn, Michelle D

    2005-01-01

    The use of lasers for material processing continues to expand, and the annual sales of such lasers exceeds $1 B (US). Large scale (many m2) processing of materials require the economical production of laser powers of the tens of kilowatts, and therefore are not yet commercial processes, although they have been demonstrated. The development of FELs based on superconducting RF (SRF) linac technology provides a scaleable path to laser outputs above 50 kW in the IR, rendering these applications economically viable, since the cost/photon drops as the output power increases. This approach also enables high average power ~ 1 kW output in the UV spectrum. Such FELs will provide quasi-cw (PRFs in the tens of MHz), of ultrafast (pulsewidth ~ 1 ps) output with very high beam quality. This talk will provide an overview of applications tests by our facility's users such as pulsed laser deposition, laser ablation, and laser surface modification, as well as present plans that will be tested with our upgraded FELs. These upg...

  6. Flux-Averaged and Volume-Averaged Concentrations in Continuum Approaches to Solute Transport

    Science.gov (United States)

    Parker, J. C.; van Genuchten, M. Th.

    1984-07-01

    Transformations between volume-averaged pore fluid concentrations and flux-averaged concentrations are presented which show that both modes of concentration obey convective-dispersive transport equations of identical mathematical form for nonreactive solutes. The pertinent boundary conditions for the two modes, however, do not transform identically. Solutions of the convection-dispersion equation for a semi-infinite system during steady flow subject to a first-type inlet boundary condition is shown to yield flux concentrations, while solutions subject to a third-type boundary condition yield volume-averaged concentrations. These solutions may be applied with reasonable impunity to finite as well as semi-infinite media if back mixing at the exit is precluded. Implications of the distinction between resident and flux concentrations to laboratory and field studies of solute transport are discussed. It is suggested that perceived limitations of the convection-dispersion model for media with large variations in pore water velocities may in certain cases be attributable to a failure to distinguish between volume-averaged and flux-averaged concentrations.

  7. Absorbed dose measurements in mammography using Monte Carlo method and ZrO{sub 2}+PTFE dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Duran M, H. A.; Hernandez O, M. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Col. Centro, 83190 Hermosillo, Sonora (Mexico); Salas L, M. A.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Pinedo S, A.; Ventura M, J.; Chacon, F. [Hospital General de Zona No. 1, IMSS, Interior Alameda 45, 98000 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F.(Mexico)], e-mail: hduran20_1@hotmail.com

    2009-10-15

    Mammography test is a central tool for breast cancer diagnostic. In addition, programs are conducted periodically to detect the asymptomatic women in certain age groups; these programs have shown a reduction on breast cancer mortality. Early detection of breast cancer is achieved through a mammography, which contrasts the glandular and adipose tissue with a probable calcification. The parameters used for mammography are based on the thickness and density of the breast, their values depend on the voltage, current, focal spot and anode-filter combination. To achieve an image clear and a minimum dose must be chosen appropriate irradiation conditions. Risk associated with mammography should not be ignored. This study was performed in the General Hospital No. 1 IMSS in Zacatecas. Was used a glucose phantom and measured air Kerma at the entrance of the breast that was calculated using Monte Carlo methods and ZrO{sub 2}+PTFE thermoluminescent dosemeters, this calculation was completed with calculating the absorbed dose. (author)

  8. Global Average Brightness Temperature for April 2003

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Figure 1 This image shows average temperatures in April, 2003, observed by AIRS at an infrared wavelength that senses either the Earth's surface or any intervening cloud. Similar to a photograph of the planet taken with the camera shutter held open for a month, stationary features are captured while those obscured by moving clouds are blurred. Many continental features stand out boldly, such as our planet's vast deserts, and India, now at the end of its long, clear dry season. Also obvious are the high, cold Tibetan plateau to the north of India, and the mountains of North America. The band of yellow encircling the planet's equator is the Intertropical Convergence Zone (ITCZ), a region of persistent thunderstorms and associated high, cold clouds. The ITCZ merges with the monsoon systems of Africa and South America. Higher latitudes are increasingly obscured by clouds, though some features like the Great Lakes, the British Isles and Korea are apparent. The highest latitudes of Europe and Eurasia are completely obscured by clouds, while Antarctica stands out cold and clear at the bottom of the image. The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  9. Average stress-average strain tension-stiffening relationships based on provisions of design codes

    Institute of Scientific and Technical Information of China (English)

    Gintaris KAKLAUSKAS; Viktor GRIBNIAK; Rokas GIRDZIUS

    2011-01-01

    This research was aimed at deriving average stress-average strain tension-stiffening relationships in accordance with the provisions of design codes for reinforced concrete (RC) members.Using a proposed inverse technique,the tension-stiffening relationships were derived from moment-curvature diagrams of RC beams calculated by different code methods,namely Eurocode 2,ACI 318,and the Chinese standard GB 50010-2002.The derived tension-stiffening laws were applied in a numerical study using the nonlinear finite element software ATENA.The curvatures calculated by ATENA and the code methods were in good agreement.

  10. Disposition of firocoxib in equine plasma after an oral loading dose and a multiple dose regimen.

    Science.gov (United States)

    Cox, S; Villarino, N; Sommardahl, C; Kvaternick, V; Zarabadipour, C; Siger, L; Yarbrough, J; Amicucci, A; Reed, K; Breeding, D; Doherty, T

    2013-11-01

    The objective of this study was to determine if a single loading dose (LD), 3× the label dose of firocoxib oral paste, followed by nine maintenance doses at the current label dose achieves and maintains near steady state concentrations. Six healthy, adult mares were administered 0.3mg/kg of firocoxib on Day 0, and 0.1 mg/kg 24 h later on Day 1, and at 24 h intervals from Day 2 to Day 9, for a total of 10 doses. Blood samples were collected throughout the study. The mean firocoxib maximum plasma concentration and standard deviation was 199±97 ng/mL, 175±44 ng/mL and 183±50 ng/mL after the LD, and first and last maintenance doses, respectively. The minimum mean concentration (C(min)) increased from 100±23 ng/mL after the LD to 132±38 ng/mL at Day 7. Then, the C(min) remained constant until Day 9. The average concentration at steady state (C(avg)) was 150±45 ng/mL, which compares well to the C(avg) (130±36 ng/mL) reported after multiple daily doses at 0.1 mg/kg. The administration of the single LD allowed achievement of the average steady state drug concentrations faster than a multi-dose regimen without a loading dose. After the LD, firocoxib at 0.1 mg/kg every 24 h was able to maintain a relatively constant average drug concentration which should produce less variability in onset of action and efficacy. PMID:24076125

  11. Effective dose: a radiation protection quantity

    CERN Document Server

    Menzel, H G

    2012-01-01

    Modern radiation protection is based on the principles of justification, limitation, and optimisation. Assessment of radiation risks for individuals or groups of individuals is, however, not a primary objective of radiological protection. The implementation of the principles of limitation and optimisation requires an appropriate quantification of radiation exposure. The International Commission on Radiological Protection (ICRP) has introduced effective dose as the principal radiological protection quantity to be used for setting and controlling dose limits for stochastic effects in the regulatory context, and for the practical implementation of the optimisation principle. Effective dose is the tissue weighted sum of radiation weighted organ and tissue doses of a reference person from exposure to external irradiations and internal emitters. The specific normalised values of tissue weighting factors are defined by ICRP for individual tissues, and used as an approximate age- and sex-averaged representation of th...

  12. Interpreting Sky-Averaged 21-cm Measurements

    Science.gov (United States)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  13. Optimal estimation of the diffusion coefficient from non-averaged and averaged noisy magnitude data

    Science.gov (United States)

    Kristoffersen, Anders

    2007-08-01

    The magnitude operation changes the signal distribution in MRI images from Gaussian to Rician. This introduces a bias that must be taken into account when estimating the apparent diffusion coefficient. Several estimators are known in the literature. In the present paper, two novel schemes are proposed. Both are based on simple least squares fitting of the measured signal, either to the median (MD) or to the maximum probability (MP) value of the Probability Density Function (PDF). Fitting to the mean (MN) or a high signal-to-noise ratio approximation to the mean (HS) is also possible. Special attention is paid to the case of averaged magnitude images. The PDF, which cannot be expressed in closed form, is analyzed numerically. A scheme for performing maximum likelihood (ML) estimation from averaged magnitude images is proposed. The performance of several estimators is evaluated by Monte Carlo (MC) simulations. We focus on typical clinical situations, where the number of acquisitions is limited. For non-averaged data the optimal choice is found to be MP or HS, whereas uncorrected schemes and the power image (PI) method should be avoided. For averaged data MD and ML perform equally well, whereas uncorrected schemes and HS are inadequate. MD provides easier implementation and higher computational efficiency than ML. Unbiased estimation of the diffusion coefficient allows high resolution diffusion tensor imaging (DTI) and may therefore help solving the problem of crossing fibers encountered in white matter tractography.

  14. Registration of radiation doses

    International Nuclear Information System (INIS)

    In Finland the Radiation and Nuclear Safety Authority (STUK) is maintaining the register (called Dose Register) of the radiation exposure of occupationally exposed workers in order to ensure compliance with the principles of optimisation and individual protection. The guide contains a description of the Dose Register and specifies the responsibilities of the party running a radiation practice to report the relevant information to the Dose Register

  15. Evaluation of radiation doses in paediatric patients undergoing voiding cystourethrography

    International Nuclear Information System (INIS)

    To evaluate dose-area product, skin entrance dose and doses from fluoroscopy and radiography in voiding cystourethrography studies of pediatric patients. Procedures performed in 37 patients by four physicians of the institution were evaluated. Measurements were performed with an equipment including an ionization chamber directly coupled to the x-ray tube window and an electrometer (Diamentor) connected to a computer for data collection. Some procedures heterogeneity was observed and guidelines for good radiographic techniques were not followed. On average, 11 radiographs are performed for each study, with extended fluoroscopy time delivering a higher average final dose than those reported in the literature. The adoption of radiography with high kilo voltage technique and restricted utilization of fluoroscopy can result in a significant reduction of doses during this procedure, considering that the major contribution to the final dose comes from fluoroscopy. (author)

  16. Hearing Office Average Processing Time Ranking Report, April 2016

    Data.gov (United States)

    Social Security Administration — A ranking of ODAR hearing offices by the average number of hearings dispositions per ALJ per day. The average shown will be a combined average for all ALJs working...

  17. Hearing Office Average Processing Time Ranking Report, February 2016

    Data.gov (United States)

    Social Security Administration — A ranking of ODAR hearing offices by the average number of hearings dispositions per ALJ per day. The average shown will be a combined average for all ALJs working...

  18. Atmospheric radiation flight dose rates

    Science.gov (United States)

    Tobiska, W. K.

    2015-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

  19. Atypical endometrial cells and atypical glandular cells favor endometrial origin in Papanicolaou cervicovaginal tests: Correlation with histologic follow-up and abnormal clinical presentations

    Directory of Open Access Journals (Sweden)

    Longwen Chen

    2014-01-01

    Full Text Available The 2001 Bethesda system recommends further classifying atypical glandular cells (AGCs as either endocervical or endometrial origin. Numerous studies have investigated the clinical significance of AGC. In this study, we investigated the incidence of clinically significant lesions among women with liquid-based Papanicolaou cervicovaginal (Pap interpretations of atypical endometrial cells (AEMs or AGC favor endometrial origin (AGC-EM. More importantly, we correlated patients of AEM or AGC-EM with their clinical presentations to determine if AEM/AGC-EM combined with abnormal vaginal bleeding is associated with a higher incidence of significant endometrial pathology. All liquid-based Pap tests with an interpretation of AEM and AGC-EM from July, 2004 through June, 2009 were retrieved from the database. Women with an interpretation of atypical endocervical cells, AGC, favor endocervical origin or AGC, favor neoplastic were not included in the study. The most severe subsequent histologic diagnoses were recorded for each patient. During this 5-year period, we accessioned 332,470 Pap tests of which 169 (0.05% were interpreted as either AEM or AGC-EM. Of the 169 patients, 133 had histologic follow-up within the health care system. The patients ranged in age from 21 to 71 years old (mean 49.7. On follow-up histology, 27 (20.3% had neoplastic/preneoplastic uterine lesions. Among them, 20 patients were diagnosed with adenocarcinoma (18 endometrial, 1 endocervical, and 1 metastatic colorectal, 3 with atypical endometrial hyperplasia, and 4 with endometrial hyperplasia without atypia. All patients with significant endometrial pathology, except one, were over 40 years old, and 22 of 25 patients reported abnormal vaginal bleeding at the time of endometrial biopsy or curettage. This study represents a large series of women with liquid-based Pap test interpretations of AEM and AGC-EM with clinical follow-up. Significant preneoplastic or neoplastic endometrial

  20. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Science.gov (United States)

    2010-07-01

    ... average and corporate pool average sulfur level determined? 80.205 Section 80.205 Protection of... ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.205 How is the annual refinery or importer average and corporate pool average sulfur level determined? (a) The annual refinery or importer average...

  1. Derivation of dose conversion factors for tritium

    Energy Technology Data Exchange (ETDEWEB)

    Killough, G. G.

    1982-03-01

    For a given intake mode (ingestion, inhalation, absorption through the skin), a dose conversion factor (DCF) is the committed dose equivalent to a specified organ of an individual per unit intake of a radionuclide. One also may consider the effective dose commitment per unit intake, which is a weighted average of organ-specific DCFs, with weights proportional to risks associated with stochastic radiation-induced fatal health effects, as defined by Publication 26 of the International Commission on Radiological Protection (ICRP). This report derives and tabulates organ-specific dose conversion factors and the effective dose commitment per unit intake of tritium. These factors are based on a steady-state model of hydrogen in the tissues of ICRP's Reference Man (ICRP Publication 23) and equilibrium of specific activities between body water and other tissues. The results differ by 27 to 33% from the estimate on which ICRP Publication 30 recommendations are based. The report also examines a dynamic model of tritium retention in body water, mineral bone, and two compartments representing organically-bound hydrogen. This model is compared with data from human subjects who were observed for extended periods. The manner of combining the dose conversion factors with measured or model-predicted levels of contamination in man's exposure media (air, drinking water, soil moisture) to estimate dose rate to an individual is briefly discussed.

  2. LOW DOSE MAGNESIUM SULPHATE REGIME FOR ECLAMPSIA

    Directory of Open Access Journals (Sweden)

    Bangal V

    2009-09-01

    Full Text Available Pre- eclampsia is one of the commonest medical complications seen during pregnancy. It contributes significantly to maternal and perinatal morbidity and mortality. Dr.J.A.Pritchard in 1955, introduced magnesium sulphate for control of convulsions in eclampsia and is used worldwide. Considering the low body mass index of indian women, a low dose magnesium sulphate regime has been introduced by some authors. Present study was carried out at tertiary care centre in rural area. Fifty cases of eclampsia were randomly selected to find out the efficacy of low dose magnesium sulphate regime to control eclamptic convulsions. Maternal and perinatal outcome and magnesium toxicity were analyzed. It was observed that 86% cases responded to initial intravenous dose of 4 grams of 20% magnesium sulphate . Eight percent cases, who got recurrence of convulsion, were controlled by additional 2 grams of 20% magnesium sulphate. Six percent cases required shifting to standard Pritchard regime, as they did not respond to low dose magnesium sulphate regime. The average total dose of magnesium sulphate required for control of convulsions was 20 grams ie. 54.4% less than that of standard Pritchard regime. The maternal and perinatal morbidity and mortality in the present study werecomparable to those of standard Pritchard regime. The study did not find a single case of magnesium related toxicity with low dose magnesium sulphate regime. Low dose magnesium sulphate regime was found to be safe and effective in eclampsia.

  3. Dose reconstruction in deforming lung anatomy: Dose grid size effects and clinical implications

    International Nuclear Information System (INIS)

    In this study we investigated the accumulation of dose to a deforming anatomy (such as lung) based on voxel tracking and by using time weighting factors derived from a breathing probability distribution function (p.d.f.). A mutual information registration scheme (using thin-plate spline warping) provided a transformation that allows the tracking of points between exhale and inhale treatment planning datasets (and/or intermediate state scans). The dose distributions were computed at the same resolution on each dataset using the Dose Planning Method (DPM) Monte Carlo code. Two accumulation/interpolation approaches were assessed. The first maps exhale dose grid points onto the inhale scan, estimates the doses at the 'tracked' locations by trilinear interpolation and scores the accumulated doses (via the p.d.f.) on the original exhale data set. In the second approach, the 'volume' associated with each exhale dose grid point (exhale dose voxel) is first subdivided into octants, the center of each octant is mapped to locations on the inhale dose grid and doses are estimated by trilinear interpolation. The octant doses are then averaged to form the inhale voxel dose and scored at the original exhale dose grid point location. Differences between the interpolation schemes are voxel size and tissue density dependent, but in general appear primarily only in regions with steep dose gradients (e.g., penumbra). Their magnitude (small regions of few percent differences) is less than the alterations in dose due to positional and shape changes from breathing in the first place. Thus, for sufficiently small dose grid point spacing, and relative to organ motion and deformation, differences due solely to the interpolation are unlikely to result in clinically significant differences to volume-based evaluation metrics such as mean lung dose (MLD) and tumor equivalent uniform dose (gEUD). The overall effects of deformation vary among patients. They depend on the tumor location, field

  4. The monthly-averaged and yearly-averaged cosine effect factor of a heliostat field

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Elsayed, M.M. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Dept. of Thermal Engineering)

    1992-01-01

    Calculations are carried out to determine the dependence of the monthly-averaged and the yearly-averaged daily cosine effect factor on the pertinent parameters. The results are plotted on charts for each month and for the full year. These results cover latitude angles between 0 and 45[sup o]N, for fields with radii up to 50 tower height. In addition, the results are expressed in mathematical correlations to facilitate using them in computer applications. A procedure is outlined to use the present results to preliminary layout the heliostat field, and to predict the rated MW[sub th] reflected by the heliostat field during a period of a month, several months, or a year. (author)

  5. Critical metal blistering doses

    Energy Technology Data Exchange (ETDEWEB)

    Kalin, B.A.; Kirilin, N.M.; Pisarev, A.A.

    1975-08-01

    Critical He ion bombardment doses associated with blistering of Nb and stainless steel were measured. It was found that the critical doses for these materials are close together and in the range 1 to 4 x 10/sup 17/ ion/cm/sup 2/. (JRD)

  6. 人子宫内膜腺上皮和基质细胞的分离与培养%Isolation and cultivation of human endometrial glandular epithelial cells and stromal cells in vitro

    Institute of Scientific and Technical Information of China (English)

    韩冬; 王自能

    2011-01-01

    Objective To explore a convenient method of separating and culturing human endometrial glandular epithelial cells and stromal cells in vitro. Methods Human endometrial glandular epithelial cells and stromal cells from 5 cases were separated by filtrated method and gradient centrifugation. The separate cells were identified by immunocytochemical staining and laser scanning confocal microscopy. Results The expression score of CK-19 in endometrial glandular epithelial cells was 4.16 ± 0.22 , and that of Vimentin in stromal cells was 4.24 ±0.22 in cells separated by gradient centrifugation , both were significantly different from those separated by filtrated method (P < 0.05). Conclusion A simple and convenient method to separate and culture human endometrial glandular epithelial cells and stromal cells can be obtained by the modified gradient centrifugation.%目的:探索一种简便人子宫内膜腺上皮细胞和基质细胞的分离培养方法.方法:通过筛网法和差速离心法,分离培养5例子宫内膜腺上皮和基质细胞,利用免疫细胞化学染色及其激光共聚焦显微镜鉴定分离的细胞并进行图像分析.结果:用差速离心法分离子宫内膜腺上皮细胞中CK-19阳性表达积分为4.16±0.22,子宫内膜基质细胞中Vimentin阳性表达积分为4.24±0.22,与筛网法相比较差异有统计学意义(P<0.05).结论:通过改良差速离心法使腺上皮和基质细胞分离步骤简化,是一种较理想子宫内膜细胞分离培养方法.

  7. Analysis of records of external occupational dose records in Brazil; Analise dos registros de dose ocupacional externa no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Mauricio, Claudia L.P.; Silva, Herica L.R. da, E-mail: claudia@ird.gov.br, E-mail: herica@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil); Silva, Claudio Ribeiro da, E-mail: claudio@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Brazil, a continental country, with actually more than 150,000 workers under individual monitoring for ionizing radiation, has implemented in 1987 a centralized system for storage of external occupational dose. This database has been improved over the years and is now a web-based information system called Brazilian External Occupational Dose Management Database System - GDOSE. This paper presents an overview of the Brazilian external occupational dose over the years. The estimated annual average effective dose shows a decrease from 2.4 mSv in 1987 to about 0.6 mSv, having been a marked reduction from 1987 to 1990. Analyzing by type of controlled practice, one sees that the medical and dental radiology is the area with the largest number of users of individual monitors (70%); followed by education practices (8%) and the industrial radiography (7%). Additionally to photon whole body monitoring; neutron monitors are used in maintenance (36%), reactor (30%) and education (27%); and extremity monitors, in education (27%), nuclear medicine (22%) and radiology (19%). In terms of collective dose, the highest values are also found in conventional radiology, but the highest average dose values are those of interventional radiology. Nuclear medicine, R and D and radiotherapy also have average annual effective dose higher than 1 mSv. However, there is some very high dose values registered in GDOSE that give false information. This should be better analyzed in the future. Annual doses above 500 are certainly not realistic. (author)

  8. Dose response relationship at low doses

    International Nuclear Information System (INIS)

    The data that have accrued in Hiroshima and Nagasaki on the effects of ionizing radiation on the developing human brain are reviewed. Effects considered are severe mental retardation, lowered IQ scores, decline in school performance, seizures, other neuropsychological effects, and small head size. All these factors may be related to radiation doses received by the mother during pregnancy. (L.L.) 3 figs., tab., 7 refs

  9. Gonad doses in biliary tract examinations (cholecystography)

    International Nuclear Information System (INIS)

    622 single measurements of gonad doses were performed during cholecystography in patients of either sex (intravaginally in women). In oral cholecystography on an average 13 mR were revealed for men and 149 mR for women, resp. According to a minimum, medium, or maximum extent of examination, in intravenous cholecystography the data for men were 11, 17, and 24 mR, while the corresponding data for women were 93, 185, and 278 mR. Based on about 400,000 cholegraphic examinations per year in the GDR the contribution to the total gonad dose caused by radiological examinations is 6-8%. (author)

  10. 40 CFR 1033.710 - Averaging emission credits.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Averaging emission credits. 1033.710... Averaging emission credits. (a) Averaging is the exchange of emission credits among your engine families. You may average emission credits only as allowed by § 1033.740. (b) You may certify one or more...

  11. 7 CFR 51.577 - Average midrib length.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Average midrib length. 51.577 Section 51.577... STANDARDS) United States Standards for Celery Definitions § 51.577 Average midrib length. Average midrib length means the average length of all the branches in the outer whorl measured from the point...

  12. 7 CFR 760.640 - National average market price.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false National average market price. 760.640 Section 760.640....640 National average market price. (a) The Deputy Administrator will establish the National Average... average quality loss factors that are reflected in the market by county or part of a county. (c)...

  13. 40 CFR 80.67 - Compliance on average.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Compliance on average. 80.67 Section...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.67 Compliance on average. The requirements... with one or more of the requirements of § 80.41 is determined on average (“averaged gasoline”)....

  14. Eye lens dose in interventional cardiology.

    Science.gov (United States)

    Principi, S; Delgado Soler, C; Ginjaume, M; Beltran Vilagrasa, M; Rovira Escutia, J J; Duch, M A

    2015-07-01

    The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y(-1), averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y(-1). This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y(-1). Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y(-1). It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. PMID:25809107

  15. Eye lens dose in interventional cardiology

    International Nuclear Information System (INIS)

    The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y-1 , averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y-1 . This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y-1. Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y-1. It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. (authors)

  16. TU-F-17A-08: The Relative Accuracy of 4D Dose Accumulation for Lung Radiotherapy Using Rigid Dose Projection Versus Dose Recalculation On Every Breathing Phase

    International Nuclear Information System (INIS)

    Purpose: To investigate the accuracy of 4D dose accumulation using projection of dose calculated on the end-exhalation, mid-ventilation, or average intensity breathing phase CT scan, versus dose accumulation performed using full Monte Carlo dose recalculation on every breathing phase. Methods: Radiotherapy plans were analyzed for 10 patients with stage I-II lung cancer planned using 4D-CT. SBRT plans were optimized using the dose calculated by a commercially-available Monte Carlo algorithm on the end-exhalation 4D-CT phase. 4D dose accumulations using deformable registration were performed with a commercially available tool that projected the planned dose onto every breathing phase without recalculation, as well as with a Monte Carlo recalculation of the dose on all breathing phases. The 3D planned dose (3D-EX), the 3D dose calculated on the average intensity image (3D-AVE), and the 4D accumulations of the dose calculated on the end-exhalation phase CT (4D-PR-EX), the mid-ventilation phase CT (4D-PR-MID), and the average intensity image (4D-PR-AVE), respectively, were compared against the accumulation of the Monte Carlo dose recalculated on every phase. Plan evaluation metrics relating to target volumes and critical structures relevant for lung SBRT were analyzed. Results: Plan evaluation metrics tabulated using 4D-PR-EX, 4D-PR-MID, and 4D-PR-AVE differed from those tabulated using Monte Carlo recalculation on every phase by an average of 0.14±0.70 Gy, - 0.11±0.51 Gy, and 0.00±0.62 Gy, respectively. Deviations of between 8 and 13 Gy were observed between the 4D-MC calculations and both 3D methods for the proximal bronchial trees of 3 patients. Conclusions: 4D dose accumulation using projection without re-calculation may be sufficiently accurate compared to 4D dose accumulated from Monte Carlo recalculation on every phase, depending on institutional protocols. Use of 4D dose accumulation should be considered when evaluating normal tissue complication

  17. BNCT and dose fractionation

    International Nuclear Information System (INIS)

    Some portion of the radiation dose received by a patient during BNCT consists of primary and secondary gammas. The biological effect of that portion of the dose will depend upon the time history of the delivered dose. The well-known models for relating time-dose effects to clinical experience, are of questionable value in understanding dose effects in the time regime of a few hours, and for doses of less than tolerance. In order to examine the time-dose effect in the regime of interest to BNCT a simple phenomenological model was developed and normalized to the accepted body of clinical experience. The model has been applied to the question of fractionation of BNCT and the results are presented. The model is simply a linear healing model with two time constants. In other words, a first hit of radiation is assumed to wound (or potentiate) a cell. Given time, the cell will fully repair itself. If a second hit occurs before the cell has healed, the cell is killed. Apparently, there are two kinds of healing, one which occurs in 30 to 60 minutes, the other in two to four days. A small fraction of the cells will die on the first hit

  18. Radiation doses to rodents inhabiting a radioactive waste receiving area

    International Nuclear Information System (INIS)

    A study was conducted of the gamma ray doses to four species of native rodents inhabiting a low level radioactive liquid waste disposal area. Absorbed doses of radiation were measured with lithium fluoride thermoluminescent dosimeters that were implanted subcutaneously. The absorbed radiation doses and 137Cs body burdens were significantly higher for western harvest mice (Reithrodontomys megalotis) than for deer mice (Peromyscus maniculatus), pinon mice (P. truei) and the least chipmunk (Eutamias minimus), reflecting differences in mobility and habitat preferences of the respective species. The average dose received by harvest mice was 26 mrad/day, which was 26% of the highest gamma dose detected at the ground surface in the study plot, although the maximum dose received by individual mice was as high as 45% of the maximum dose rates in the plot. (author)

  19. Kinetic energy equations for the average-passage equation system

    Science.gov (United States)

    Johnson, Richard W.; Adamczyk, John J.

    1989-01-01

    Important kinetic energy equations derived from the average-passage equation sets are documented, with a view to their interrelationships. These kinetic equations may be used for closing the average-passage equations. The turbulent kinetic energy transport equation used is formed by subtracting the mean kinetic energy equation from the averaged total instantaneous kinetic energy equation. The aperiodic kinetic energy equation, averaged steady kinetic energy equation, averaged unsteady kinetic energy equation, and periodic kinetic energy equation, are also treated.

  20. Dose verification exercise at Agrosurg irradiators (India)

    International Nuclear Information System (INIS)

    Accurate dose measurements traceable to recognized national standards are essential components of industrial radiation processing. M/s Agrosurg, Vasai, India designed for source strength of 37 PBq (1000 kCi) of Cobalt-60, is a fully automatic and continuous gamma irradiation facility for sterilization of medical or surgical products and disinfestations of Agro products. Dose verification exercise for processing of poha was carried out using Ceric-cerous (3 mM) dosimeter and Alanine EPR pellet dosimeter by Agrosurg and RP and AD respectively. The Dmin and Dmax values specified for poha for insect disinfestations are 0.2 kGy and 1 kGy respectively. The overall uncertainty in dose delivered to food product, during routine food irradiation, shall not exceed ± 10 % (1σ). Dmin and Dmax values for both the boxes agree very well. The maximum difference observed between individual Agrosurg and RP and AD dose value was within 10%. The Over Dose Ratio of 1.42 measured by Agrosurg agree well with the ODR value 1.45 measured by RP and AD. As overall average dose delivered to the food product agrees within ±10 % (1σ), the Gamma Irradiation Facility viz., Agrosurg was issued license for food irradiation by the competent authority

  1. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    Energy Technology Data Exchange (ETDEWEB)

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2012-11-15

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose

  2. Radiation dose in vertebroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Mehdizade, A.; Lovblad, K.O.; Wilhelm, K.E.; Somon, T.; Wetzel, S.G.; Kelekis, A.D.; Yilmaz, H.; Abdo, G.; Martin, J.B.; Viera, J.M.; Ruefenacht, D.A. [Neuroradiology DRRI, Geneva University Hospital, Rue Micheli-du-Crest 24, 1211, Geneva 14 (Switzerland)

    2004-03-01

    We wished to measure the absorbed radiation dose during fluoroscopically controlled vertebroplasty and to assess the possibility of deterministic radiation effects to the operator. The dose was measured in 11 consecutive procedures using thermoluminescent ring dosimeters on the hand of the operator and electronic dosimeters inside and outside of the operator's lead apron. We found doses of 0.022-3.256 mGy outside and 0.01-0.47 mGy inside the lead apron. Doses on the hand were higher, 0.5-8.5 mGy. This preliminary study indicates greater exposure to the operator's hands than expected from traditional apron measurements. (orig.)

  3. Controllable dose; Dosis controlable

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Anaya M, R.A. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: jtar@nuclear.inin.mx

    2004-07-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  4. Gonadal doses from radiotherapy

    International Nuclear Information System (INIS)

    The method of calculation of gonadal doses arising from different radiotherapeutic procedures is described. The measurement of scatter factors to the gonads from superficial and deep therapy is detailed and the analytic fits to the experimental data, as a function of field position, field size and beam energy are given. The data used to calculate the gonadal doses from treatments using linear accelerators, teletherapy and sealed sources are described and the analytic fits to the data given

  5. Effects of low doses

    International Nuclear Information System (INIS)

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  6. Radiation Doses Received by the Irish Population 2014

    International Nuclear Information System (INIS)

    People are constantly exposed to a variety of sources of both natural and artificial radioactivity. The radiation dose received by the population from such sources is periodically estimated by the Radiological Protection Institute of Ireland RPII. This report is an update of a population dose assessment undertaken in 2008 and includes the most recent data available on the principal radiation exposure pathways. Wherever possible the collective dose and the resulting average annual dose to an individual living in Ireland, based on the most recently published figure for the population of Ireland, have been calculated for each of the pathways of exposure

  7. Estimation of organ doses and risk from personnel monitoring data

    International Nuclear Information System (INIS)

    The study of occupationally exposed workers to radiation has been based on recorded annual radiation doses. Personal monitoring programs in Ghana use thermoluminescent dosimeter to measure the whole body radiation dose and not the actual dose to the organs and tissues. In this study, Bayesian Statistical model has been used to estimate the annual effective doses to the organs and tissues of radiation workers including red bone marrow, female breast, thyroid, ovary, testes, lung and skin. The organ doses averaged over a cohort of occupationally exposed workers were estimated from personal monitoring data over a period of five years. The results from the study shows that the skin is more susceptible to radiation with the highest mean dose of 1.15±0.59 mSv averaged over five years followed by the thyroid and the female breast with the mean dose of 0.90±0.46 mSv and 0.72±0.38 msV averaged over five years respectively. The red bone marrow, ovary and lungs received the lowest doses with the mean dose estimate of 0.12 ± 0.11 mSv, 0.20±0.10mSv and 0.39±0.19mSv averaged over five years respectively. The statistical analysis software, SPSS was used to analyze the recorded data. The estimated mean annual cancer risks using International Commission on Radiological protection publication 103 showed low estimate's as compared to the international reference levels. The study shows that the radiation doses are within the limits for occupational exposure indicating that medical facilities and techniques used are adequate and acceptable. (au)

  8. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography

    International Nuclear Information System (INIS)

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  9. Internal individual dose monitoring and estimation of dose equivalent from workers of the development and production of radioisotopes in CIAE

    International Nuclear Information System (INIS)

    The results of internal individual dose monitoring from workers of the development and production of radioisotopes in CIAE (1995-2000) are presented. The annual average committed effective dose is 1.8 x 10-2 - 8.0 x 10-1 mSv and the collective committed effective dose is 2.9 x 10-3 - 9.8 x 10-2 man·Sv in 1995-2000. The collective committed effective dose is 1.6 x 10-1 man·Sv and the annual average committed effective dose is 1.8 x 10-1 mSv for the 873 persons from 1995-2000

  10. How to understand low dose risks

    International Nuclear Information System (INIS)

    It is well established that those who were exposed to ionizing radiation have increased risks of developing malignancies. The magnitude of the risk varies depending on not only the dose but also age at the time of exposure, gender, background incidence rate etc. In the case of atomic bomb survivors, the relative risk of cancer is linearly related to the dose, and the sex averaged relative risk (exposure age is 30, risk calculation is when they reached age 70) is 1.5 at 1 Gy. Because the increased risks below 100 to 200 mGy are too small and not statistically significant, there are arguments in interpreting the risks at the low dose range. (author)

  11. Recent advances in the development of high average power induction accelerators for industrial and environmental applications

    International Nuclear Information System (INIS)

    Short-pulse accelerator technology developed during time period from the early 60's through the late 80's is now being extended to high average power systems capable of being used in industrial and environmental applications. Processes requiring high dose levels and/or high volume throughput may require systems with beam power levels from several hundreds of kilowatts to megawatts. Processes may include chemical waste mitigation, flue gas cleanup, food pasteurization, and new forms of materials preparation and treatment. This paper will address the present status of high average power systems now in operation that use combinations of semiconductor and saturable core magnetic switches with inductive voltage adders to achieve MeV beams of electrons or x-rays over areas of 10,000 cm2 or more. Similar high average power technology is also being used below 1 MeV to drive repetitive ion beam sources for treatment of material surfaces

  12. Medical x-ray exposure doses as contaminants of atomic bomb doses.

    Science.gov (United States)

    Yamamoto, O; Antoku, S; Russell, W J; Fujita, S; Sawada, S

    1988-03-01

    Since 1967 at the times of their biennial ABCC/RERF radiological examinations, all Adult Health Study (AHS) subjects have been interviewed to determine the exposures to medical x-rays they experienced in institutions other than RERF in order to estimate the numbers of examinations and corresponding doses which they received. These data have been stored on computer tapes together with the doses these subjects received during their radiological examinations in the ABCC/RERF Department of Radiology. Thus, their medical x-ray doses are available along with their atomic bomb doses (tentative 1965 doses revised, T65DR) for assessment of the role of ionizing radiation in the development of diseases. The medical x-ray doses incurred at RERF were assessed by means of phantom dosimetry. Those at other institutions were determined using phantom dosimetry data and results of surveys for trends in radiological examinations in Hiroshima and Nagasaki. By the end of 1982, the average medical x-ray doses to the active bone marrow were 12.04 mGy for A-bomb exposed groups and 8.92 mGy for control groups (not-in-cities); to the male gonads, 2.26 mGy and 1.89 mGy, respectively; and to the female gonads, 17.45 mGy and 12.58 mGy, respectively. Results for Hiroshima and Nagasaki were similar. The main impact of medical x-ray doses was in the lowest T65DR group. Medical x-ray active bone marrow doses ranged from 0.05-500% (mean, 35%) of A-bomb doses in the 10-99 mGy T65DR group. In the 100-999 mGy T65DR group, medical x-ray active bone marrow doses ranged from 0.005-50% (mean, 5%) of their T65DR. In the greater than 1,000-mGy T65DR group, medical x-ray exposures were proportionally less. Female active bone marrow and gonad doses were similar in magnitude to the male active bone marrow doses. Medical x-ray exposures produced smaller doses to the gonads of males than to those of the females. The use of medical x-rays is steadily increasing. Careful consideration of doses from medical sources

  13. Dose evaluation in special fluoroscopy procedures: Hysterosalpingography and Dacryocystography; Avaliacao de dose em procedimentos especiais de fluoroscopia: histerossalpingografia e dacriocistografia

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Cintya Carolina Barbosa

    2006-04-15

    The hysterosalpingography (HSG) and dacryocystography (DCG) are among the special fluoroscopy procedures. The HSG is a radiodiagnostic technique used to detect uterine and tubal pathologies and it is fundamental for the investigation of infertility. The DCG is a form of lacrimal system imaging, being important to show the level of obstruction, the presence of dilatation of the lacrimal sac, as well as alterations in nearby structures. At this research, the study of skin entrance dose was evaluated for these two special fluoroscopy procedures, besides the analyses of staff doses whose performs the exams. The exams of 22 HSG patients and 8 DCG patients were evaluated using TL-100 dosimeters attached on patient' skin at anatomical landmarks evolved on each exam. In the case of HSG, the results showed that skin entrance doses varied from 0.5 mGy to 73.4 mGy, with an average value of 22.1 mGy. The estimated uterus dose was 5.5 mGy, and 6.6 mGy was the average dose estimated to the ovaries. The patient' skin entrance dose undergoing to DCG examinations varied from 2.1 mGy to 10.6 mGy, and the average eye's dose was 6.1 mGy. The results of staff dose showed that, on HSG, the average dose on doctor's right hand was 4.3 mGy per examination. This value had to the fact that the physician introduces the contrast manually while all contrast exposures. In relation of DCG, the staff's dose values were nearby background radiation, evidencing that, inside of permitted limits, there is no risk for the physicians at this procedure. (author)

  14. Average annual runoff in the United States, 1951-80

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This is a line coverage of average annual runoff in the conterminous United States, 1951-1980. Surface runoff Average runoff Surface waters United States

  15. Seasonal Sea Surface Temperature Averages, 1985-2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of four images showing seasonal sea surface temperature (SST) averages for the entire earth. Data for the years 1985-2001 are averaged to...

  16. Average American 15 Pounds Heavier Than 20 Years Ago

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160233.html Average American 15 Pounds Heavier Than 20 Years Ago ... since the late 1980s and early 1990s, the average American has put on 15 or more additional ...

  17. Analysis of the occupational doses of female radiation workers in India

    International Nuclear Information System (INIS)

    Basis for control of occupational exposures of women are same as that of men except for pregnant women. Analysis of annual and cumulative occupational doses of female radiation workers as a group has been done. The average annual dose data in the four broad categories and age wise dose distribution is presented. The average working period for female radiation workers is about 3 to 5 years which is same as that of all the radiation workers on our records. The average cumulative dose for female workers is about 3 mSv. (author). 4 refs., 4 tabs

  18. The SU(N) Wilson Loop Average in 2 Dimensions

    OpenAIRE

    Karjalainen, Esa

    1993-01-01

    We solve explicitly a closed, linear loop equation for the SU(2) Wilson loop average on a two-dimensional plane and generalize the solution to the case of the SU(N) Wilson loop average with an arbitrary closed contour. Furthermore, the flat space solution is generalized to any two-dimensional manifold for the SU(2) Wilson loop average and to any two-dimensional manifold of genus 0 for the SU(N) Wilson loop average.

  19. Average of Distribution and Remarks on Box-Splines

    Institute of Scientific and Technical Information of China (English)

    LI Yue-sheng

    2001-01-01

    A class of generalized moving average operators is introduced, and the integral representations of an average function are provided. It has been shown that the average of Dirac δ-distribution is just the well known box-spline. Some remarks on box-splines, such as their smoothness and the corresponding partition of unity, are made. The factorization of average operators is derived. Then, the subdivision algorithm for efficient computing of box-splines and their linear combinations follows.

  20. Investigating Averaging Effect by Using Three Dimension Spectrum

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The eddy current displacement sensor's averaging effect has been investigated in this paper,and thefrequency spectrum property of the averaging effect was also deduced. It indicates that the averaging effect has no influences on measuring a rotor's rotating error, but it has visible influences on measuring the rotor's profile error. According to the frequency spectrum of the averaging effect, the actual sampling data can be adjusted reasonably, thus measuring precision is improved.