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Sample records for radiation standards complex

  1. US Army primary radiation standards complex

    SciTech Connect

    Rogers, S.C.

    1993-12-31

    This paper describes the U.S. Army Primary Radiation Standards Complex (PRSC) to be constructed at Redstone Arsenal, Alabama. The missions of the organizations to be located in the PRSC are described. The health physics review of the facility design is discussed. The radiation sources to be available in the PRSC and the resulting measurement capabilities of the Army Primary Standards Laboratory Nucleonics section are specified. Influence of the National Voluntary Laboratory Accrediation Program (NVLAP) accreditation criteria on facility design and source selection is illustrated.

  2. Radiation protection standards in space.

    PubMed

    Sinclair, W K

    1986-01-01

    Radiation protection standards for the individual exposed to ionizing radiation in his/her daily work have evolved over more than 50 years since the first recommendations on limits by the NCRP and the ICRP. Initial standards were based on the absence of observable harm, notably skin erythema, but have since been modified as other concerns, such as leukemia and genetic effects, became more important. More recently, the general carcinogenic effect of radiation has become the principal concern at low doses. Genetic effects are also of concern in the younger individual. Modern radiation protection practices take both of these risks into account. Quantification of these risks improves as new information emerges. The study of the Japanese survivors of the atomic bombs continues to yield new information and the recent revisions in the dosimetry are about to be completed. The special circumstances of space travel suggest approaches to limits not unlike those for radiation workers on the ground. One approach is to derive a career limit based on the risks of accident faced by many nonradiation workers in a lifetime. The career limit can be apportioned according to the type of mission. The NCRP is considering this and other approaches to the specification of radiation standards in space.

  3. Development of radiation protection standards

    SciTech Connect

    Edwards, M. )

    1991-07-01

    Radiation protection standards are based on the best available knowledge, caution, and perception. Dose limits for occupational exposure have decreased as knowledge was gained about radiation effects: from 0.6 Sv (60 rem)/year for 1900-1930 to 50 mSv (5 rem)/year in 1958 (the level still used as of 1990). Current dose limits for public exposure range from 1 mSv to 5 mSv, depending on frequency of exposure. For the embryo and fetus, dose limits are 0.5 mSv/mo and 5 mSv for the entire gestation. In the 1970s, the concept of acceptable risk and that of a non-threshold dose-response relationship became the basis for setting dose limits. Three principles of radiation protection are that (a) dose levels should not exceed acceptable levels, (b) optimal dose levels should be as low as reasonably achievable, and (c) radiation should not be used unless it produces a positive net benefit. Although no dose limits have been set for patients undergoing diagnostic and therapeutic radiologic procedures, such measures must provide a net benefit to patients at optimal dose levels.

  4. New Standards for Ultraviolet Radiation

    NASA Technical Reports Server (NTRS)

    Sliney, D. H.

    1971-01-01

    Guidelines covering safe levels for exposure to ultraviolet radiation in an occupational environment are reported. The guidelines clarify the spectral radiant exposure doses and relative spectral effectiveness of ultraviolet radiation required to elicit adverse biologic effects.

  5. Viewpoint on proposed radiation-protection standards

    SciTech Connect

    Auxier, J.A.

    1982-01-01

    The proposed revision of 10CFR20 is discussed from a personal perspective. A brief historical review of the development of radiation standards is presented, and arguments against the proposed de minimis level elaborated upon. (ACR)

  6. A standard for ultraviolet radiation.

    NASA Technical Reports Server (NTRS)

    Fisher, G. B.; Spicer, W. E.; Mckernan, P. C.; Pereskok, V. F.; Wanner, S. J.

    1973-01-01

    Photoemission diode standards for accurately measuring monochromatic ultraviolet light intensity (3000 A-1100 A) are described that are also blind to visible light. The standard uses an opaque photocathode of Cs2Te and is unique because of its combination of thinness (19 mm), high sensitivity, time stability, and uniformity of response. Design criteria, construction methods, and difficulties overcome in obtaining a stable, uniform, high yield photocathode responses are discussed. Cs2Te is discussed in terms of a model for high yield photoemitters.

  7. Meeting Standard 10: Reading Complex Text

    ERIC Educational Resources Information Center

    Hiebert, Elfrieda H.; Mesmer, Heidi Anne E.

    2013-01-01

    Most principals know about the Common Core State Standards, but they may not be aware that they are different from previous standards in one essential way: they emphasize students' capacity to understand complex texts. Standard 10 puts an unprecedented focus on texts and will fundamentally change assessments, textbooks, and teaching at the…

  8. 41 CFR 50-204.36 - Radiation standards for mining.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Department of Labor, Radiation Safety and Health Standards (41 CFR 50-204.36). You should preserve this... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Radiation standards for... CONTRACTS Radiation Standards § 50-204.36 Radiation standards for mining. (a) For the purpose of...

  9. 41 CFR 50-204.36 - Radiation standards for mining.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Department of Labor, Radiation Safety and Health Standards (41 CFR 50-204.36). You should preserve this... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Radiation standards for... CONTRACTS Radiation Standards § 50-204.36 Radiation standards for mining. (a) For the purpose of...

  10. 41 CFR 50-204.36 - Radiation standards for mining.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Department of Labor, Radiation Safety and Health Standards (41 CFR 50-204.36). You should preserve this... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Radiation standards for... CONTRACTS Radiation Standards § 50-204.36 Radiation standards for mining. (a) For the purpose of...

  11. 41 CFR 50-204.36 - Radiation standards for mining.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Department of Labor, Radiation Safety and Health Standards (41 CFR 50-204.36). You should preserve this... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Radiation standards for... CONTRACTS Radiation Standards § 50-204.36 Radiation standards for mining. (a) For the purpose of...

  12. 41 CFR 50-204.36 - Radiation standards for mining.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Department of Labor, Radiation Safety and Health Standards (41 CFR 50-204.36). You should preserve this... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Radiation standards for... CONTRACTS Radiation Standards § 50-204.36 Radiation standards for mining. (a) For the purpose of...

  13. Standardizing Naming Conventions in Radiation Oncology

    SciTech Connect

    Santanam, Lakshmi; Hurkmans, Coen; Mutic, Sasa; Vliet-Vroegindeweij, Corine van; Brame, Scott; Straube, William; Galvin, James; Tripuraneni, Prabhakar; Michalski, Jeff; Bosch, Walter

    2012-07-15

    Purpose: The aim of this study was to report on the development of a standardized target and organ-at-risk naming convention for use in radiation therapy and to present the nomenclature for structure naming for interinstitutional data sharing, clinical trial repositories, integrated multi-institutional collaborative databases, and quality control centers. This taxonomy should also enable improved plan benchmarking between clinical institutions and vendors and facilitation of automated treatment plan quality control. Materials and Methods: The Advanced Technology Consortium, Washington University in St. Louis, Radiation Therapy Oncology Group, Dutch Radiation Oncology Society, and the Clinical Trials RT QA Harmonization Group collaborated in creating this new naming convention. The International Commission on Radiation Units and Measurements guidelines have been used to create standardized nomenclature for target volumes (clinical target volume, internal target volume, planning target volume, etc.), organs at risk, and planning organ-at-risk volumes in radiation therapy. The nomenclature also includes rules for specifying laterality and margins for various structures. The naming rules distinguish tumor and nodal planning target volumes, with correspondence to their respective tumor/nodal clinical target volumes. It also provides rules for basic structure naming, as well as an option for more detailed names. Names of nonstandard structures used mainly for plan optimization or evaluation (rings, islands of dose avoidance, islands where additional dose is needed [dose painting]) are identified separately. Results: In addition to its use in 16 ongoing Radiation Therapy Oncology Group advanced technology clinical trial protocols and several new European Organization for Research and Treatment of Cancer protocols, a pilot version of this naming convention has been evaluated using patient data sets with varying treatment sites. All structures in these data sets were

  14. Radiative effects in the standard model extension

    NASA Astrophysics Data System (ADS)

    Zhukovsky, V. Ch.; Lobanov, A. E.; Murchikova, E. M.

    2006-03-01

    The possibility of radiative effects induced by the Lorentz and CPT noninvariant interaction term for fermions in the standard model extension is investigated. In particular, electron-positron photo production and photon emission by electrons and positrons are studied. The rates of these processes are calculated in the Furry picture. It is demonstrated that the rates obtained in the framework of the model adopted strongly depend on the polarization states of the particles involved. As a result, ultrarelativistic particles produced should occupy states with a preferred spin orientation, i.e., photons have the sign of polarization opposite to the sign of the effective potential, while charged particles are preferably in the state with the helicity coinciding with the sign of the effective potential. This leads to evident spatial asymmetries which may have certain consequences observable at high energy accelerators, and in astrophysical and cosmological studies.

  15. Radiative Effects in the Standard Model Extension

    NASA Astrophysics Data System (ADS)

    Zhukovsky, V. Ch.; Lobanov, A. E.; Murchikova, E. M.

    2006-10-01

    The possibility of radiative effects that are due to interaction of fermions with the constant axial-vector background in the standard model extension is investigated. Electron-positron photo-production and photon emission by electrons and positrons were studied. The rates of these processes were calculated in the Furry picture. It was demonstrated that the rates obtained strongly depend on the polarization states of the particles involved. In consequence of this fact ultra-relativistic particles should occupy states with a preferred spin orientation, i.e., photons have the sign of polarization opposite to the sign of the effective potential, while charged particle are preferably in the state with the helicity coinciding with the sign of the effective potential. This leads to evident spatial asymmetries.

  16. Review of standards for limitation of radiation dose to radiation workers and members of the public

    SciTech Connect

    Kocher, D.C.

    1992-01-01

    Topics covered in the review include: current radiation protection standards for workers; current radiation protection standards for the routine exposures of the public; environmental radiation standards for specific practices or sources; protective action guides for accidental releases of radioactivity to the environment; de minimis dose, exempt levels of radioactivity, and below regulatory concern.

  17. Review of standards for limitation of radiation dose to radiation workers and members of the public

    SciTech Connect

    Kocher, D.C.

    1992-07-01

    Topics covered in the review include: current radiation protection standards for workers; current radiation protection standards for the routine exposures of the public; environmental radiation standards for specific practices or sources; protective action guides for accidental releases of radioactivity to the environment; de minimis dose, exempt levels of radioactivity, and below regulatory concern.

  18. Radiation protection and shielding standards for the 1980s

    SciTech Connect

    Trubey, D.K.

    1982-01-01

    The American Nuclear Society (ANS) is a standards-writing organization member of the American National Standards Institute (ANSI). The ANS Standards Committee has a subcommittee denoted ANS-6, Radiation Protection and Shielding, whose charge is to develop standards for radiation protection and shield design, to provide shielding information to other standards-writing groups, and to develop standard reference shielding data and test problems. This paper is a progress report of this subcommittee. Significant progress has been made since the last comprehensive report to the Society.

  19. Revision of the ISO and EN radiation sterilization standards

    NASA Astrophysics Data System (ADS)

    Miller, Arne; Hansen, Joyce

    2002-03-01

    The radiation sterilization standards, ISO 11137 and EN 552, are now being revised under "ISO lead", with the aim of producing only one international standard, although in four parts: (1) requirements, (2) dose-setting methods, (3) dose-substantiation methods and (4) dosimetry. Several aspects of the old standards that have caused problems, when they were used in practice, are addressed in the revision. Input from users of the standards is necessary in order that the standards be developed as useful tools in the documentation of radiation sterilization.

  20. Radiation standards and A-bomb survivors

    SciTech Connect

    Alvarez, R.

    1984-10-01

    For more than 33 years, the US government has supported the Life Span Study of Japanese survivors as a follow-up of the 1945 nuclear bombings of Hiroshima and Nagasaki. Since 1975, the study has been funded jointly by the United States and Japan under the auspices of the Radiation Effects Research Foundation. In the May issue of this bulletin radiation epidemiologists Dr. Alice Stewart and George Kneale raise perhaps the most fundamental question of all: Does the Japanese A-bomb survivor study have any value in deriving risk estimates for low-level radiation. On the basis of data published by the Radiation Effects Research Foundation in 1978, Stewart and Kneale suggest that Foundation analysts have confused long-term effects of tissue-destructive high doses with single-cell low-dose effects. If they are correct, the method of linear extrapolation from high-dose studies for low-level radiation risk estimates is invalid. The author feels the A-bomb survivors study should be opened up to an independent peer review process.

  1. Radiation damage to DNA-protein complexes

    NASA Astrophysics Data System (ADS)

    Spotheim-Maurizot, M.; Davídková, M.

    2011-01-01

    We review here the advances in understanding the effects of ionizing radiations on DNA, proteins and their complexes, resulting from the collaboration of the authors' teams. It concerns the preponderant indirect effect of low LET ionizing radiations, thus the attack of the macromolecules in aqueous solution by the most aggressive product of water radiolysis, the hydroxyl radical. A model of simulation of the reaction of these radicals with the macromolecules (called RADACK) was developed and was used for calculating the probabilities of damage of each constituent of DNA or proteins (nucleotide or amino-acid). The calculations allowed to draw conclusions from electrophoresis, mutagenesis, spectroscopic (fluorescence, circular dichroïsm) and mass spectrometry experiments. Thus we have shown that the extent and location of the lesions are strongly dependent on the 3D structure of the macromolecules, which in turns is modulated by their sequence and by the binding of some ligands. Molecular dynamics simulation completed our studies in showing the consequences of each lesion on the stability and structure of the proteins and their complexes with DNA.

  2. History, current status, and trends of radiation protection standards.

    PubMed

    Hendee, W R

    1993-01-01

    Quantitative standards for protection against exposure to ionizing radiation were first formulated in the 1930s. Since that time, standards have been restated periodically in different radiation units and conceptual frameworks that reflect improved understanding of the biological effects of radiation interactions and their consequences for human health. In the 1970s the expression of protection standards shifted from a dose- to a risk-based approach, with dose limits established to yield risks to radiation workers comparable with those for workers in other "safe" industries. Over the years, radiation protection standards have exhibited a downward trend to more rigorous limits that require increased commitments of personnel and resources for their enforcement. There are several reasons for this trend, including increased recognition of the long-term health effects of radiation, improved protection measures that permit radiation use at lower levels of exposure, growing numbers of persons exposed occupationally to radiation, and probably a greater intolerance to involuntary risks in society, with radiation targeted as a highly visible source of involuntary risks in the form of nuclear power plants and radioactive waste sites. In the past few years, reports of the Radiation Effects Research Foundation, United Nations Scientific Committee on the Effects of Atomic Radiation, and the National Research Council of the U.S. National Academy of Sciences have presented increased risk estimates for radiation exposure as a consequence of ongoing epidemiological analyses of human populations exposed to ionizing radiation. These risk estimates have enhanced public concern about radiation exposure and set the stage for discussions about the desirability of further reductions in exposure standards for radiation workers and members of the public. Such reductions would directly affect the professional activities, educational responsibilities, and administrative burdens of most medical

  3. IEC International Standards Under Development For Radiation-Generating Devices

    SciTech Connect

    Voytchev, M; Radev, R; Chiaro, P; Thomson, I; Dray, C; Li, J

    2007-12-06

    The International Electrotechnical Commission (IEC) is the leading and oldest global organization with over 100 years history of developing and publishing international standards for all electrical, electronic and related technologies, including radiation detection instrumentation. Subcommittee 45B 'Radiation Protection Instrumentation' of the IEC has recently started the development of two standards on radiation-generating devices. IEC 62463 'Radiation protection instrumentation--X-ray Systems for the Screening of Persons for Security and the Carrying of Illicit Items' is applicable to X-ray systems designed for screening people to detect if they are carrying objects such as weapons, explosives, chemical and biological agents and other concealed items that could be used for criminal purposes, e.g. terrorist use, drug smuggling, etc. IEC 62523 'Radiation protection instrumentation--Cargo/Vehicle radiographic inspection systems' applies to cargo/vehicle imaging inspection systems using accelerator produced X-ray or gamma radiation to obtain images of the screened objects (e.g. cargo containers, transport and passenger vehicles and railroad cars). The objective of both standards is to specify standard requirements and general characteristics and test procedures, as well as, radiation, electrical, environmental, mechanical, and safety requirements and to provide examples of acceptable methods to test these requirements. In particular the standards address the design requirements as they relate to the radiation protection of the people being screened, people who are in the vicinity of the equipment and the operators. The standard IEC 62463 does not deal with the performance requirements for the quality of the object detection. Compliance with the standards requirements will provide the manufacturers with internationally acceptable specifications and the device users with assurance of the rigorous quality and accuracy of the measurements in relation to the radiological

  4. Twenty new ISO standards on dosimetry for radiation processing

    NASA Astrophysics Data System (ADS)

    Farrar, H., IV

    2000-03-01

    Twenty standards on essentially all aspects of dosimetry for radiation processing were published as new ISO standards in December 1998. The standards are based on 20 standard practices and guides developed over the past 14 years by Subcommittee E10.01 of the American Society for Testing and Materials (ASTM). The transformation to ISO standards using the 'fast track' process under ISO Technical Committee 85 (ISO/TC85) commenced in 1995 and resulted in some overlap of technical information between three of the new standards and the existing ISO Standard 11137 Sterilization of health care products — Requirements for validation and routine control — Radiation sterilization. Although the technical information in these four standards was consistent, compromise wording in the scopes of the three new ISO standards to establish precedence for use were adopted. Two of the new ISO standards are specifically for food irradiation applications, but the majority apply to all forms of gamma, X-ray, and electron beam radiation processing, including dosimetry for sterilization of health care products and the radiation processing of fruit, vegetables, meats, spices, processed foods, plastics, inks, medical wastes, and paper. Most of the standards provide exact procedures for using individual dosimetry systems or for characterizing various types of irradiation facilities, but one covers the selection and calibration of dosimetry systems, and another covers the treatment of uncertainties using the new ISO Type A and Type B evaluations. Unfortunately, nine of the 20 standards just adopted by the ISO are not the most recent versions of these standards and are therefore already out of date. To help solve this problem, efforts are being made to develop procedures to coordinate the ASTM and ISO development and revision processes for these and future ASTM-originating dosimetry standards. In the meantime, an additional four dosimetry standards have recently been published by the ASTM but

  5. Ultraviolet Radiation Dose National Standard of México

    NASA Astrophysics Data System (ADS)

    Cardoso, R.; Rosas, E.

    2006-09-01

    We present the Ultraviolet (UV) Radiation Dose National Standard for México. The establishment of this measurement reference at Centro Nacional de Metrología (CENAM) eliminates the need of contacting foreign suppliers in the search for traceability towards the SI units when calibrating instruments at 365 nm. Further more, the UV Radiation Dose National Standard constitutes a highly accurate and reliable source for the UV radiation dose measurements performed in medical and cosmetic treatments as in the the food and pharmaceutics disinfection processes, among other.

  6. Environmental radiation protection: philosophy, monitoring and standards.

    PubMed

    Janssens, Augustin

    2004-01-01

    The Euratom Treaty confers important powers to the European Commission with regard to monitoring and assessment of levels of radioactivity in the environment and discharges with effluents (Articles 35-37 of the Euratom Treaty). Current developments in the area relate to harmonised reporting of environmental data and to harmonisation of effluent monitoring data. Both developments relate to the requirement under the new Basic Safety Standards (BSS) for a realistic assessment of population exposure. Guidance to this effect is being prepared by the Article 31 Group of Experts. In the context of Article 36 intercomparison exercises for radionuclides measurements in environmental samples are organised. New challenges for environmental monitoring result from the requirement under the BSS to regulate also industries processing NORM materials. Also the international move towards extending the scope of environmental radioactivity to the protection of biota opens new perspectives.

  7. Transport and radiation in complex LTE mixtures

    NASA Astrophysics Data System (ADS)

    Janssen, Jesper; Peerenboom, Kim; Suijker, Jos; Gnybida, Mykhailo; van Dijk, Jan

    2014-10-01

    Complex LTE mixtures are for example encountered in re-entry, welding, spraying and lighting. These mixtures typically contain a rich chemistry in combination with large temperature gradients. LTE conditions are also interesting because they can aid in the validation of NLTE algorithms. An example is the calculation of transport properties. In this work a mercury free high intensity discharge lamp is considered. The investigation focusses on using salts like InI or SnI as a buffer species. By using these species a dominant background gas like mercury is no longer present. As a consequence the diffusion algorithms based on Fick's law are no longer applicable and the Stefan-Maxwell equations must be solved. This system of equations is modified with conservation rules to set a coldspot pressure for saturated species and enforce the mass dosage for unsaturated species. The radiative energy transport is taken into account by raytracing. Quantum mechanical simulations have been used to calculate the potential curves and the transition dipole moments for indium with iodine and tin with iodine. The results of these calculations have been used to predict the quasistatic broadening by iodine. The work was supported by the project SCHELP from the Belgium IWT (Project Number 110003) and the CATRENE SEEL Project (CA502).

  8. On the complexity of triggering evolutionary radiations.

    PubMed

    Bouchenak-Khelladi, Yanis; Onstein, Renske E; Xing, Yaowu; Schwery, Orlando; Linder, H Peter

    2015-07-01

    Recent developments in phylogenetic methods have made it possible to reconstruct evolutionary radiations from extant taxa, but identifying the triggers of radiations is still problematic. Here, we propose a conceptual framework to explore the role of variables that may impact radiations. We classify the variables into extrinsic conditions vs intrinsic traits, whether they provide background conditions, trigger the radiation, or modulate the radiation. We used three clades representing angiosperm phylogenetic and structural diversity (Ericaceae, Fagales and Poales) as test groups. We located radiation events, selected variables potentially associated with diversification, and inferred the temporal sequences of evolution. We found 13 shifts in diversification regimes in the three clades. We classified the associated variables, and determined whether they originated before the relevant radiation (backgrounds), originated simultaneously with the radiations (triggers), or evolved later (modulators). By applying this conceptual framework, we establish that radiations require both extrinsic conditions and intrinsic traits, but that the sequence of these is not important. We also show that diversification drivers can be detected by being more variable within a radiation than conserved traits that only allow occupation of a new habitat. This framework facilitates exploration of the causative factors of evolutionary radiations.

  9. Radiation hardness of Efratom M-100 rubidium frequency standard

    NASA Technical Reports Server (NTRS)

    English, T. C.; Vorwerk, H.; Rudie, N. J.

    1983-01-01

    The effects of nuclear radiation on rubidium gas cell frequency standards and components are presented, including the results of recent tests where a continuously operating rubidium frequency standard (Effratom, Model M-100) was subjected to simultaneous neutron/gamma radiation. At the highest neutron fluence 7.5 10 to the 12th power n/sq cm and total dose 11 krad(Si) tested, the unit operated satisfactorily; the total frequency change over the 2 1/2 hour test period due to all causes, including repeated retraction from and insertion into the reactor, was less than 1 x 10 to the -10th power. The effects of combined neutron/gamma radiation on rubidium frequency standard physics package components were also studied, and the results are presented.

  10. Setting standards for radiation protection: A time for change

    SciTech Connect

    Patterson, H.W.; Hickman, D.P.

    1996-01-01

    In 1950, the International Commission on Radiation Protection (ICRP) recommended that ``certain radiation effects are irreversible and cumulative.`` Furthermore, the ICRP ``strongly recommended that every effort be made to reduce exposures to all types of ionizing radiations to the lowest possible level.`` Then in 1954, the ICRP published its assumption that human response to ionizing radiation was linear with dose, together with the recommendation that exposures be kept as low as practicable. These concepts are still the foundation of radiation protection policy today, even though, as Evans has stated, ``The linear non-threshold (LNT) model was adopted specifically on a basis of mathematical simplicity, not from radio-biological data.... Groups responsible for setting standards for radiation protection should be abreast of new developments and new data as they are published; however, this does not seem to be the case. For example, there have been many reports in scientific, peer-reviewed, and other publications during the last three decades that have shown the LNT model and the policy of As Low As Reasonably Achievable (ALARA) to be invalid. However, none of these reports has been refuted or even discussed by standard-setting groups. We believe this mandates a change in the standard-setting process.

  11. Radiation therapy: model standards for determination of need

    SciTech Connect

    Lagasse, L.G.; Devins, T.B.

    1982-03-01

    Contents: Health planning process; Health care requirements (model for projecting need for megavoltage radiation therapy); Operational objectives (manpower, megavoltage therapy and treatment planning equipment, support services, management and evaluation of patient care, organization and administration); Compliance with other standards imposed by law; Financial feasibility and capability; Reasonableness of expenditures and costs; Relative merit; Environmental impact.

  12. Radiative breaking of conformal symmetry in the Standard Model

    NASA Astrophysics Data System (ADS)

    Arbuzov, A. B.; Nazmitdinov, R. G.; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.

    2016-02-01

    Radiative mechanism of conformal symmetry breaking in a comformal-invariant version of the Standard Model is considered. The Coleman-Weinberg mechanism of dimensional transmutation in this system gives rise to finite vacuum expectation values and, consequently, masses of scalar and spinor fields. A natural bootstrap between the energy scales of the top quark and Higgs boson is suggested.

  13. Evolution of radiation resistance in a complex microenvironment

    NASA Astrophysics Data System (ADS)

    Kim, So Hyun; Austin, Robert; Mehta, Monal; Kahn, Atif

    2013-03-01

    Radiation treatment responses in brain cancers are typically associated with short progression-free intervals in highly lethal malignancies such as glioblastomas. Even as patients routinely progress through second and third line salvage therapies, which are usually empirically selected, surprisingly little information exists on how cancer cells evolve resistance. We will present experimental results showing how in the presence of complex radiation gradients evolution of resistance to radiation occurs. Sponsored by the NCI/NIH Physical Sciences Oncology Centers

  14. The Common Core State Standards' Quantitative Text Complexity Trajectory: Figuring out How Much Complexity Is Enough

    ERIC Educational Resources Information Center

    Williamson, Gary L.; Fitzgerald, Jill; Stenner, A. Jackson

    2013-01-01

    The Common Core State Standards (CCSS) set a controversial aspirational, quantitative trajectory for text complexity exposure for readers throughout the grades, aiming for all high school graduates to be able to independently read complex college and workplace texts. However, the trajectory standard is presented without reference to how the…

  15. International Standardization of the Clinical Dosimetry of Beta Radiation Brachytherapy Sources: Progress of an ISO Standard

    NASA Astrophysics Data System (ADS)

    Soares, Christopher

    2006-03-01

    In 2004 a new work item proposal (NWIP) was accepted by the International Organization for Standardization (ISO) Technical Committee 85 (TC85 -- Nuclear Energy), Subcommittee 2 (Radiation Protection) for the development of a standard for the clinical dosimetry of beta radiation sources used for brachytherapy. To develop this standard, a new Working Group (WG 22 - Ionizing Radiation Dosimetry and Protocols in Medical Applications) was formed. The standard is based on the work of an ad-hoc working group initiated by the Dosimetry task group of the Deutsches Insitiut für Normung (DIN). Initially the work was geared mainly towards the needs of intravascular brachytherapy, but with the decline of this application, more focus has been placed on the challenges of accurate dosimetry for the concave eye plaques used to treat ocular melanoma. Guidance is given for dosimetry formalisms, reference data to be used, calibrations, measurement methods, modeling, uncertainty determinations, treatment planning and reporting, and clinical quality control. The document is currently undergoing review by the ISO member bodies for acceptance as a Committee Draft (CD) with publication of the final standard expected by 2007. There are opportunities for other ISO standards for medical dosimetry within the framework of WG22.

  16. Status of the ESA Standard Radiation Environment Monitor (SREM) products

    NASA Astrophysics Data System (ADS)

    Nieminen, Petteri; Anastasiadis, A.; Bühler, P.; Daglis, I.; Daly, E.; Desorgher, L.; Evans, H.; Hajdas, W.; Lyons, J.; Marinov, D.; Nieminen, P.; Sandberg, I.; Siegl, M.; Tziotziou, K.; Zadeh, A.

    The ESA Standard Radiation Environment Monitor (SREM) is thus far succesfully flying and producing radiation data on Proba-1, INTEGRAL, Rosetta, Giove-B, Herschel and Planck missions, with the environments covering LEO, MEO, highly elliptical orbit, L2, and the in-terplanetary space. This presentation will outline the main SREM results to date from these various missions, and will give an overview of the present efforts taken to process the SREM data from raw particle count rates to proton and electron fluxes. Interfaces to various envi-ronment modelling activities and other higher level products are also discussed. Lessons learnt from the SREM programme will be summarised with the aim of facilitating future radiation monitor development and data processing / utilisation efforts.

  17. Monochromator-Based Absolute Calibration of a Standard Radiation Thermometer

    NASA Astrophysics Data System (ADS)

    Mantilla, J. M.; Hernanz, M. L.; Campos, J.; Martín, M. J.; Pons, A.; del Campo, D.

    2014-04-01

    Centro Español de Metrología (CEM) is disseminating the International Temperature Scale (ITS-90), at high temperatures, by using the fixed points of Ag and Cu and a standard radiation thermometer. However, the future mise-en-pratique for the definition of the kelvin ( MeP-K) will include the dissemination of the kelvin by primary methods and by indirect approximations capable of exceptionally low uncertainties or increased reliability. Primary radiometry is, at present, able to achieve uncertainties competitive with the ITS-90 above the silver point with one of the possible techniques the calibration for radiance responsivity of an imaging radiometer (radiance method). In order to carry out this calibration, IO-CSIC (Spanish Designated Institute for luminous intensity and luminous flux) has collaborated with CEM, allowing traceability to its cryogenic radiometer. A monochromator integrating sphere-based spectral comparator facility has been used to calibrate one of the CEM standard radiation thermometers. The absolute calibrated standard radiation thermometer has been used to determine the temperatures of the fixed points of Cu, Co-C, Pt-C, and Re-C. The results obtained are 1357.80 K, 1597.10 K, 2011.66 K, and 2747.64 K, respectively, with uncertainties ranging from 0.4 K to 1.1 K.

  18. Environmental Radiation Protection Standards for Yucca Mountain, Nevada

    SciTech Connect

    Clark, R. L.

    2002-02-27

    The Environmental Protection Agency (EPA) has issued radiation protection standards for the potential spent nuclear fuel and high-level radioactive waste disposal system in Yucca Mountain, Nevada. These standards are found in Part 197 of Title 40 of the Code of Federal Regulations (40 CFR Part 197). The Energy Policy Act of 1992 directed, and gave the authority to, EPA to take this action based upon input from the National Academy of Sciences (NAS). The final standards were published in the Federal Register (66 FR 32073) on 13 June 2001. The 40 CFR Part 197 standards have four major parts: (1) individual-protection during storage activities; (2) individual-protection following closure of the repository; (3) human-intrusion; and (4) ground-water protection. The storage standard is 150 microsieverts (Sv) annual committed effective dose equivalent (CEDE) to any member of the general public. The disposal standards are: (1) 150 Sv annual CEDE for the reasonably maximally exposed individual (RMEI) for 10,000 years after disposal; (2) 150 Sv received by the RMEI within 10,000 years after disposal as a result of human intrusion; and (3) the levels of radionuclides in the ground water cannot exceed 40 Sv from beta and gamma emitters, 5 picocuries per liter (pCi/L) of radium-226 and -228, and 15 pCi/L of gross alpha activity. There are also requirements related to the post-10,000-year period, the basis of compliance judgments, and performance assessments. The Agency has published its responses to the comments received, its technical background document, and its economic impact analysis. In addition to printed form, the documents are available on the World Wide Web at http://www.epa.gov/radiation/yucca/index.html.

  19. Radiation safety standards: space hazards vs. terrestrial hazards.

    PubMed

    Sinclair, W K

    1983-01-01

    The standards currently recommended for use in space travel were perhaps the first risk derived recommendations for dose limitations developed for quasi-occupational circumstances. They were based on data, considerations, and philosophy existing prior to 1970 and considered carcinogenesis primarily. In the intervening twelve years, not only has radiation risk information improved markedly but considerations relating to risk in general have become better known. The earlier recommendations have been examined with respect to changes in risk estimation and it is noted that the same philosophy used today, would probably lead to different dose limitations. However, other philosophies might be used; in particular a comparison of risks between terrestrial occupational radiation circumstances and also with fatal accident rates in a range of industries can be made and might be used in a modified philosophy with respect to risks from carcinogenesis. Developments have also taken place with respect to the knowledge of the biological effects of HZE particles but whether these effects are limiting as compared with radiation induced carcinogenesis is not yet clear. More studies on the effects of HZE particles, now becoming available, are needed. It is recommended that an in depth reexamination be undertaken of the biological effectiveness of space radiations and the philosophy of dose limitations in comparison with other risks.

  20. Absorbed dose to water: Standards and traceability for radiation oncology

    SciTech Connect

    Almond, P.R.

    1995-12-31

    Although the need for appropriate quantities and units for ionizing radiation has existed since shortly after discovery of X-rays, the quantities and units in general use today were not completely formalized until about 15 years ago. The development of appropriate national and international standards have also been ongoing. For many years the quantity, exposure, measured in units of roentgen was the national standard and they were also the quantity and units in which radiotherapy was described. With the introduction of megavoltage X-ray and electron-beam equipment and the adoption of the quantity {open_quotes}absorbed-dose{close_quotes} measured in units of rad (or gray) different approaches to calibrating these beams were needed. This was especially the case since the national standard in terms of exposure at a maximum photon energy for {sup 60}Co gamma rays was only available. Since the late 1960s various machine calibration protocols have been published. These protocols have to accommodate changes in modality, energy, quantities and units between the national standard and the user. Because of this, a new definition of traceability is proposed to accommodate the present system. By recording all intercomparisons and parameters used, an auditable calibration chain can be maintained. Even with the introduction of calibration protocols based upon national absorbed dose standards, the proposed traceability definition will still be needed.

  1. Robotic Delivery of Complex Radiation Volumes for Small Animal Research

    PubMed Central

    Matinfar, Mohammad; Iordachita, Iulian; Wong, John; Kazanzides, Peter

    2011-01-01

    The Small Animal Radiation Research Platform (SARRP) is a novel and complete system capable of delivering multidirectional (focal), kilo-voltage radiation fields to targets in small animals under robotic control using cone-beam CT (CBCT) image guidance. The capability of the SARRP to deliver highly focused beams to multiple animal models provides new research opportunities that more realistically bridge laboratory research and clinical translation. This paper describes the design and operation of the SARRP for precise radiation delivery. Different delivery procedures are presented which enable the system to radiate through a series of points, representative of a complex shape. A particularly interesting case is shell dose irradiation, where the goal is to deliver a high dose of radiation to the shape surface, with minimal dose to the shape interior. The ability to deliver a dose shell allows mechanistic research of how a tumor interacts with its microenvironment to sustain its growth and lead to its resistance or recurrence. PMID:21643448

  2. Robotic Delivery of Complex Radiation Volumes for Small Animal Research.

    PubMed

    Matinfar, Mohammad; Iordachita, Iulian; Wong, John; Kazanzides, Peter

    2010-07-15

    The Small Animal Radiation Research Platform (SARRP) is a novel and complete system capable of delivering multidirectional (focal), kilo-voltage radiation fields to targets in small animals under robotic control using cone-beam CT (CBCT) image guidance. The capability of the SARRP to deliver highly focused beams to multiple animal models provides new research opportunities that more realistically bridge laboratory research and clinical translation. This paper describes the design and operation of the SARRP for precise radiation delivery. Different delivery procedures are presented which enable the system to radiate through a series of points, representative of a complex shape. A particularly interesting case is shell dose irradiation, where the goal is to deliver a high dose of radiation to the shape surface, with minimal dose to the shape interior. The ability to deliver a dose shell allows mechanistic research of how a tumor interacts with its microenvironment to sustain its growth and lead to its resistance or recurrence.

  3. 21 CFR 14.120 - Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Radiation Safety Standards Committee (TEPRSSC). 14.120 Section 14.120 Food and Drugs FOOD AND DRUG... Technical Electronic Products Radiation Safety Standards Committee § 14.120 Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC). The Technical Electronic Product...

  4. 21 CFR 14.120 - Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Radiation Safety Standards Committee (TEPRSSC). 14.120 Section 14.120 Food and Drugs FOOD AND DRUG... Technical Electronic Products Radiation Safety Standards Committee § 14.120 Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC). The Technical Electronic Product...

  5. 21 CFR 14.120 - Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Radiation Safety Standards Committee (TEPRSSC). 14.120 Section 14.120 Food and Drugs FOOD AND DRUG... Technical Electronic Products Radiation Safety Standards Committee § 14.120 Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC). The Technical Electronic Product...

  6. 21 CFR 14.120 - Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Radiation Safety Standards Committee (TEPRSSC). 14.120 Section 14.120 Food and Drugs FOOD AND DRUG... Technical Electronic Products Radiation Safety Standards Committee § 14.120 Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC). The Technical Electronic Product...

  7. 21 CFR 14.120 - Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Radiation Safety Standards Committee (TEPRSSC). 14.120 Section 14.120 Food and Drugs FOOD AND DRUG... Technical Electronic Products Radiation Safety Standards Committee § 14.120 Establishment of the Technical Electronic Product Radiation Safety Standards Committee (TEPRSSC). The Technical Electronic Product...

  8. 78 FR 21120 - Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... regulatory issues associated with radiation standards. Member agencies include the EPA; Nuclear Regulatory... AGENCY Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards AGENCY... Agency (EPA) will host a meeting of the Interagency Steering Committee on Radiation Standards (ISCORS)...

  9. 75 FR 66092 - Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-27

    ... AGENCY Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards AGENCY... (EPA) will host a meeting of the Interagency Steering Committee on Radiation Standards (ISCORS) on... of regulatory issues associated with radiation standards. Agencies represented as members of...

  10. 76 FR 70130 - Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-10

    ... AGENCY Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards AGENCY... (EPA) will host a meeting of the Interagency Steering Committee on Radiation Standards (ISCORS) on... of regulatory issues associated with radiation standards. Agencies represented as members of...

  11. 78 FR 54248 - Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-03

    ... of regulatory issues associated with radiation standards. Member agencies include: EPA; the Nuclear... AGENCY Notice of Public Meeting of the Interagency Steering Committee on Radiation Standards AGENCY... Agency (EPA) will host a meeting of the Interagency Steering Committee on Radiation Standards (ISCORS)...

  12. A novel approach to characterize information radiation in complex networks

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyang; Wang, Ying; Zhu, Lin; Li, Chao

    2016-06-01

    The traditional research of information dissemination is mostly based on the virus spreading model that the information is being spread by probability, which does not match very well to the reality, because the information that we receive is always more or less than what was sent. In order to quantitatively describe variations in the amount of information during the spreading process, this article proposes a safety information radiation model on the basis of communication theory, combining with relevant theories of complex networks. This model comprehensively considers the various influence factors when safety information radiates in the network, and introduces some concepts from the communication theory perspective, such as the radiation gain function, receiving gain function, information retaining capacity and information second reception capacity, to describe the safety information radiation process between nodes and dynamically investigate the states of network nodes. On a micro level, this article analyzes the influence of various initial conditions and parameters on safety information radiation through the new model simulation. The simulation reveals that this novel approach can reflect the variation of safety information quantity of each node in the complex network, and the scale-free network has better "radiation explosive power", while the small-world network has better "radiation staying power". The results also show that it is efficient to improve the overall performance of network security by selecting nodes with high degrees as the information source, refining and simplifying the information, increasing the information second reception capacity and decreasing the noises. In a word, this article lays the foundation for further research on the interactions of information and energy between internal components within complex systems.

  13. On a radiative origin of the Standard Model from trinification

    NASA Astrophysics Data System (ADS)

    Camargo-Molina, José Eliel; Morais, António P.; Pasechnik, Roman; Wessén, Jonas

    2016-09-01

    In this work, we present a trinification-based grand unified theory incorporating a global SU(3) family symmetry that after a spontaneous breaking leads to a left-right symmetric model. Already at the classical level, this model can accommodate the matter content and the quark Cabbibo mixing in the Standard Model (SM) with only one Yukawa coupling at the unification scale. Considering the minimal low-energy scenario with the least amount of light states, we show that the resulting effective theory enables dynamical breaking of its gauge group down to that of the SM by means of radiative corrections accounted for by the renormalisation group evolution at one loop. This result paves the way for a consistent explanation of the SM breaking scale and fermion mass hierarchies.

  14. Radiation damage to nucleoprotein complexes in macromolecular crystallography

    PubMed Central

    Bury, Charles; Garman, Elspeth F.; Ginn, Helen Mary; Ravelli, Raimond B. G.; Carmichael, Ian; Kneale, Geoff; McGeehan, John E.

    2015-01-01

    Significant progress has been made in macromolecular crystallography over recent years in both the understanding and mitigation of X-ray induced radiation damage when collecting diffraction data from crystalline proteins. In contrast, despite the large field that is productively engaged in the study of radiation chemistry of nucleic acids, particularly of DNA, there are currently very few X-ray crystallographic studies on radiation damage mechanisms in nucleic acids. Quantitative comparison of damage to protein and DNA crystals separately is challenging, but many of the issues are circumvented by studying pre-formed biological nucleoprotein complexes where direct comparison of each component can be made under the same controlled conditions. Here a model protein–DNA complex C.Esp1396I is employed to investigate specific damage mechanisms for protein and DNA in a biologically relevant complex over a large dose range (2.07–44.63 MGy). In order to allow a quantitative analysis of radiation damage sites from a complex series of macromolecular diffraction data, a computational method has been developed that is generally applicable to the field. Typical specific damage was observed for both the protein on particular amino acids and for the DNA on, for example, the cleavage of base-sugar N1—C and sugar-phosphate C—O bonds. Strikingly the DNA component was determined to be far more resistant to specific damage than the protein for the investigated dose range. At low doses the protein was observed to be susceptible to radiation damage while the DNA was far more resistant, damage only being observed at significantly higher doses. PMID:25723923

  15. Physical and biological properties of U. S. standard endotoxin EC after exposure to ionizing radiation

    SciTech Connect

    Csako, G.; Elin, R.J.; Hochstein, H.D.; Tsai, C.M.

    1983-07-01

    Techniques that reduce the toxicity of bacterial endotoxins are useful for studying the relationship between structure and biological activity. We used ionizing radiation to detoxify a highly refined endotoxin preparation. U.S. standard endotoxin EC. Dose-dependent changes occurred by exposure to /sup 60/Co-radiation in the physical properties and biological activities of the endotoxin. Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis showed gradual loss of the polysaccharide components (O-side chain and R-core) from the endotoxin molecules. In contrast, although endotoxin revealed a complex absorption pattern in the UV range, radiation treatment failed to modify that pattern. Dose-related destruction of the primary toxic component, lipid A, was suggested by the results of activity tests: both the pyrogenicity and limulus reactivity of the endotoxin were destroyed by increasing doses of radiation. The results indicate that the detoxification is probably due to multiple effects of the ionizing radiation on bacterial lipopolysaccharides, and the action involves (i) the destruction of polysaccharide moieties and possibly (ii) the alteration of lipid A component of the endotoxin molecule.

  16. In situ TEM of radiation effects in complex ceramics.

    PubMed

    Lian, Jie; Wang, L M; Sun, Kai; Ewing, Rodney C

    2009-03-01

    In situ transmission electron microscopy (TEM) has been extensively applied to study radiation effects in a wide variety of materials, such as metals, ceramics and semiconductors and is an indispensable tool in obtaining a fundamental understanding of energetic beam-matter interactions, damage events, and materials' behavior under intense radiation environments. In this article, in situ TEM observations of radiation effects in complex ceramics (e.g., oxides, silicates, and phosphates) subjected to energetic ion and electron irradiations have been summarized with a focus on irradiation-induced microstructural evolution, changes in microchemistry, and the formation of nanostructures. New results for in situ TEM observation of radiation effects in pyrochlore, A(2)B(2)O(7), and zircon, ZrSiO(4), subjected to multiple beam irradiations are presented, and the effects of simultaneous irradiations of alpha-decay and beta-decay on the microstructural evolution of potential nuclear waste forms are discussed. Furthermore, in situ TEM results of radiation effects in a sodium borosilicate glass subjected to electron-beam exposure are introduced to highlight the important applications of advanced analytical TEM techniques, including Z-contrast imaging, energy filtered TEM (EFTEM), and electron energy loss spectroscopy (EELS), in studying radiation effects in materials microstructural evolution and microchemical changes. By combining ex situ TEM and advanced analytical TEM techniques with in situ TEM observations under energetic beam irradiations, one can obtain invaluable information on the phase stability and response behaviors of materials under a wide range of irradiation conditions.

  17. 10 CFR 71.47 - External radiation standards for all packages.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CFR 20.1502. (c) For shipments made under the provisions of paragraph (b) of this section, the shipper... 10 Energy 2 2014-01-01 2014-01-01 false External radiation standards for all packages. 71.47... MATERIAL Package Approval Standards § 71.47 External radiation standards for all packages. (a) Except...

  18. 10 CFR 71.47 - External radiation standards for all packages.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... CFR 20.1502. (c) For shipments made under the provisions of paragraph (b) of this section, the shipper... 10 Energy 2 2012-01-01 2012-01-01 false External radiation standards for all packages. 71.47... MATERIAL Package Approval Standards § 71.47 External radiation standards for all packages. (a) Except...

  19. 10 CFR 71.47 - External radiation standards for all packages.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CFR 20.1502. (c) For shipments made under the provisions of paragraph (b) of this section, the shipper... 10 Energy 2 2013-01-01 2013-01-01 false External radiation standards for all packages. 71.47... MATERIAL Package Approval Standards § 71.47 External radiation standards for all packages. (a) Except...

  20. 10 CFR 71.47 - External radiation standards for all packages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CFR 20.1502. (c) For shipments made under the provisions of paragraph (b) of this section, the shipper... 10 Energy 2 2010-01-01 2010-01-01 false External radiation standards for all packages. 71.47... MATERIAL Package Approval Standards § 71.47 External radiation standards for all packages. (a) Except...

  1. 10 CFR 71.47 - External radiation standards for all packages.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CFR 20.1502. (c) For shipments made under the provisions of paragraph (b) of this section, the shipper... 10 Energy 2 2011-01-01 2011-01-01 false External radiation standards for all packages. 71.47... MATERIAL Package Approval Standards § 71.47 External radiation standards for all packages. (a) Except...

  2. Formation of Complex Molecules via radiative association reactions

    NASA Astrophysics Data System (ADS)

    Acharyya, Kinsuk; Herbst, Eric

    2016-07-01

    The detection of increasing numbers of complex organic molecules in the various phases of star formation plays a key role since they follow the same chemical rules of carbon-based chemistry that are observed in our planet Earth. Many of these molecules are believed to be formed on the surfaces of grains, and can then be released to the gas phase when these grains are heated. This is evident when we observe a rich chemistry in hot core regions. However, recently complex organic molecules have also been observed in cold clouds. Therefore, it is necessary to re-examine various pathways for the formation of these molecules in the gas phase. In this presentation, I will discuss role of radiative association reactions in the formation of complex molecules in the gas phase and at low temperature. We will compare abundance of assorted molecules with and without new radiative association reactions and will show that the abundance of a few complex molecules such as HCOOCH3, CH3OCH3 etc. can go up due to introduction of these reactions, which can help to explain their observed abundances.

  3. Standards for Radiation Effects Testing: Ensuring Scientific Rigor in the Face of Budget Realities and Modern Device Challenges

    NASA Technical Reports Server (NTRS)

    Lauenstein, J M.

    2015-01-01

    An overview is presented of the space radiation environment and its effects on electrical, electronic, and electromechanical parts. Relevant test standards and guidelines are listed. Test standards and guidelines are necessary to ensure best practices, minimize and bound systematic and random errors, and to ensure comparable results from different testers and vendors. Test standards are by their nature static but exist in a dynamic environment of advancing technology and radiation effects research. New technologies, failure mechanisms, and advancement in our understanding of known failure mechanisms drive the revision or development of test standards. Changes to standards must be weighed against their impact on cost and existing part qualifications. There must be consensus on new best practices. The complexity of some new technologies exceeds the scope of existing test standards and may require development of a guideline specific to the technology. Examples are given to illuminate the value and limitations of key radiation test standards as well as the challenges in keeping these standards up to date.

  4. Electron acceleration and radiation in evolving complex active regions

    NASA Astrophysics Data System (ADS)

    Anastasiadis, A.; Gontikakis, C.; Vilmer, N.; Vlahos, L.

    2004-07-01

    We present a model for the acceleration and radiation of solar energetic particles (electrons) in evolving complex active regions. The spatio - temporal evolution of active regions is calculated using a cellular automaton model, based on self-organized criticality. The acceleration of electrons is due to the presence of randomly placed, localized electric fields produced by the energy release process, simulated by the cellular automaton model. We calculate the resulting kinetic energy distributions of the particles and their emitted X-ray radiation spectra using the thick target approximation, and we perform a parametric study with respect to number of electric fields present and thermal temperature of the injected distribution. Finally, comparing our results with the existing observations, we find that they are in a good agreement with the observed X-ray spectra in the energy range 100-1000 keV.

  5. RNA protects a nucleoprotein complex against radiation damage

    PubMed Central

    Bury, Charles S.; McGeehan, John E.; Antson, Alfred A.; Carmichael, Ian; Gerstel, Markus; Shevtsov, Mikhail B.; Garman, Elspeth F.

    2016-01-01

    Radiation damage during macromolecular X-ray crystallographic data collection is still the main impediment for many macromolecular structure determinations. Even when an eventual model results from the crystallographic pipeline, the manifestations of radiation-induced structural and conformation changes, the so-called specific damage, within crystalline macromolecules can lead to false interpretations of biological mechanisms. Although this has been well characterized within protein crystals, far less is known about specific damage effects within the larger class of nucleoprotein complexes. Here, a methodology has been developed whereby per-atom density changes could be quantified with increasing dose over a wide (1.3–25.0 MGy) range and at higher resolution (1.98 Å) than the previous systematic specific damage study on a protein–DNA complex. Specific damage manifestations were determined within the large trp RNA-binding attenuation protein (TRAP) bound to a single-stranded RNA that forms a belt around the protein. Over a large dose range, the RNA was found to be far less susceptible to radiation-induced chemical changes than the protein. The availability of two TRAP molecules in the asymmetric unit, of which only one contained bound RNA, allowed a controlled investigation into the exact role of RNA binding in protein specific damage susceptibility. The 11-fold symmetry within each TRAP ring permitted statistically significant analysis of the Glu and Asp damage patterns, with RNA binding unexpectedly being observed to protect these otherwise highly sensitive residues within the 11 RNA-binding pockets distributed around the outside of the protein molecule. Additionally, the method enabled a quantification of the reduction in radiation-induced Lys and Phe disordering upon RNA binding directly from the electron density. PMID:27139628

  6. On the planetary and Milne problems in complex radiative transfer

    NASA Astrophysics Data System (ADS)

    Viik, T.

    2016-11-01

    In this paper we consider two classical problems in radiative transfer - the planetary and the Milne problems - in an isotropic homogeneous optically semi-infinite medium where the albedo of single scattering may be defined anywhere in the complex plane. It appeared that the method of approximating the kernel in the integral equation for the Sobolev resolvent function can be used even in such a case. This approach allows to express almost all the relevant functions of transfer for those problems by simply determinable auxiliary functions.

  7. Provisional standards of radiation safety of flight personnel and passengers in air transport of the civil aviation

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Provisional standards for radiation affecting passenger aircraft are considered. Agencies responsible for seeing that the regulations are enforced are designated while radiation sources and types of radiation are defined. Standard levels of permissible radiation are given and conditions for radiation safety are discussed. Dosimetric equipment on board aircraft is delineated and regulation effective dates are given.

  8. Solar Origin of Solar Particle Events Detected by the Standard Radiation Environment Monitor of ESA

    NASA Astrophysics Data System (ADS)

    Tziotziou, K.; Sandberg, I.; Anastasiadis, A.; Daglis, I. A.; Panagopoulos, I.; Mavromichalaki, H.; Papaioannou, A.; Gerontidou, M.; Nieminen, P.; Glover, A.

    2010-07-01

    Solar Particle Events (SPEs) of the 23rd Solar Cycle detected by the ESA Standard Radiation Environment Monitor (SREM) onboard the INTEGRAL satellite have been studied in order to find their connection to solar sources. X-ray, optical and radio data of solar flares that were observed by several space-based instruments during the aforementioned solar cycle have been selected. The data were reduced and thoroughly analyzed in order to establish the corresponding solar origin of the selected SPEs. The extensive scientific analysis has produced clear correlations with X class solar flares for the events of the October-November 2003, January 2005 and December 2006 periods while for the events that occurred during September 2005, correlations with X class flares are possible but not straightforward due to the complexity of the registered solar particle fluxes.

  9. Radiation scales on which standard values of the solar constant and solar spectral irradiance are based

    NASA Technical Reports Server (NTRS)

    Thekaekara, M. P.

    1972-01-01

    The question of radiation scales is critically examined. There are two radiation scales which are of fundamental validity and there are several calibration standards and radiation scales which have been set up for practical convenience. The interrelation between these scales is investigated. It is shown that within the limits of accuracy of irradiance measurements in general and solar irradiance measurements in particular, the proposed standard values of the solar constant and solar spectrum should be considered to be on radiation scales of fundamental validity; those based on absolute electrical units and on the thermodynamic Kelvin temperature scale.

  10. National Education Standards: The Complex Challenge for Educational Leaders.

    ERIC Educational Resources Information Center

    Faidley, Ray; Musser, Steven

    1991-01-01

    National standards for education are important elements in the excellence process, but standards imposed by a central authority simply do not work in the Information Era. It would be wise to increase teachers' decision-making role in establishing and implementing local level excellence standards and train teachers to employ the Japanese "kaizen"…

  11. Numerical simulation of radiation fog in complex terrain

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Musson-Genon, L.; Carissimo, B.; Dupont, E.

    2009-09-01

    The interest for micro-scale modeling of the atmosphere is growing for environmental applications related, for example, to energy production, transport and urban development. The turbulence in the stable layers where pollutant dispersion is low and can lead to strong pollution events. This could be further complicated by the presence of clouds or fog and is specifically difficult in urban or industrial area due to the presence of buildings. In this context, radiation fog formation and dissipation over complex terrain were therefore investigated with a state-of-the-art model. This study is divided into two phases. The first phase is a pilot stage, which consist of employing a database from the ParisFog campaign which took place in the south of Paris during winter 2006-07 to assess the ability of the cloud model to reproduce the detailed structure of radiation fog. The second phase use the validated model for the study of influence of complex terrain on fog evolution. Special attention is given to the detailed and complete simulations and validation technique used is to compare the simulated results using the 3D cloud model of computational fluid dynamical software Code_Saturne with one of the best collected in situ data during the ParisFog campaign. Several dynamical, microphysical parameterizations and simulation conditions have been described. The resulting 3D cloud model runs at a horizontal resolution of 30 m and a vertical resolution comparable to the 1D model. First results look very promising and are able to reproduce the spatial distribution of fog. The analysis of the behavior of the different parameterized physical processes suggests that the subtle balance between the various processes is achieved.

  12. Regional cancer centre demonstrates voluntary conformity with the national Radiation Oncology Practice Standards.

    PubMed

    Manley, Stephen; Last, Andrew; Fu, Kenneth; Greenham, Stuart; Kovendy, Andrew; Shakespeare, Thomas P

    2015-06-01

    Radiation Oncology Practice Standards have been developed over the last 10 years and were published for use in Australia in 2011. Although the majority of the radiation oncology community supports the implementation of the standards, there has been no mechanism for uniform assessment or governance. North Coast Cancer Institute's public radiation oncology service is provided across three main service centres on the north coast of NSW. With a strong focus on quality management, we embraced the opportunity to demonstrate conformity with the Radiation Oncology Practice Standards. The Local Health District's Clinical Governance units were engaged to perform assessments of our conformity with the standards and this was signed off as complete on 16 December 2013. The process of demonstrating conformity with the Radiation Oncology Practice Standards has enhanced the culture of quality in our centres. We have demonstrated that self-assessment utilising trained auditors is a viable method for centres to demonstrate conformity. National implementation of the Radiation Oncology Practice Standards will benefit individual centres and the broader radiation oncology community to improve the service delivered to our patients.

  13. Regional cancer centre demonstrates voluntary conformity with the national Radiation Oncology Practice Standards

    SciTech Connect

    Manley, Stephen Last, Andrew; Fu, Kenneth; Greenham, Stuart; Kovendy, Andrew; Shakespeare, Thomas P

    2015-06-15

    Radiation Oncology Practice Standards have been developed over the last 10 years and were published for use in Australia in 2011. Although the majority of the radiation oncology community supports the implementation of the standards, there has been no mechanism for uniform assessment or governance. North Coast Cancer Institute's public radiation oncology service is provided across three main service centres on the north coast of NSW. With a strong focus on quality management, we embraced the opportunity to demonstrate conformity with the Radiation Oncology Practice Standards. The Local Health District's Clinical Governance units were engaged to perform assessments of our conformity with the standards and this was signed off as complete on 16 December 2013. The process of demonstrating conformity with the Radiation Oncology Practice Standards has enhanced the culture of quality in our centres. We have demonstrated that self-assessment utilising trained auditors is a viable method for centres to demonstrate conformity. National implementation of the Radiation Oncology Practice Standards will benefit individual centres and the broader radiation oncology community to improve the service delivered to our patients.

  14. Regional cancer centre demonstrates voluntary conformity with the national Radiation Oncology Practice Standards

    PubMed Central

    Manley, Stephen; Last, Andrew; Fu, Kenneth; Greenham, Stuart; Kovendy, Andrew; Shakespeare, Thomas P

    2015-01-01

    Radiation Oncology Practice Standards have been developed over the last 10 years and were published for use in Australia in 2011. Although the majority of the radiation oncology community supports the implementation of the standards, there has been no mechanism for uniform assessment or governance. North Coast Cancer Institute's public radiation oncology service is provided across three main service centres on the north coast of NSW. With a strong focus on quality management, we embraced the opportunity to demonstrate conformity with the Radiation Oncology Practice Standards. The Local Health District's Clinical Governance units were engaged to perform assessments of our conformity with the standards and this was signed off as complete on 16 December 2013. The process of demonstrating conformity with the Radiation Oncology Practice Standards has enhanced the culture of quality in our centres. We have demonstrated that self-assessment utilising trained auditors is a viable method for centres to demonstrate conformity. National implementation of the Radiation Oncology Practice Standards will benefit individual centres and the broader radiation oncology community to improve the service delivered to our patients. PMID:26229680

  15. US Department of Energy standardized radiation safety training

    SciTech Connect

    Trinoskey, P.A.

    1997-02-01

    The following working groups were formed under the direction of a radiological training coordinator: managers, supervisors, DOE auditors, ALARA engineers/schedulers/planners, radiological control personnel, radiation-generating device operators, emergency responders, visitors, Pu facilities, U facilities, tritium facilities, accelerator facilities, biomedical researchers. General courses for these groups are available, now or soon, in the form of handbooks.

  16. Student Reading Growth Illuminates the Common Core Text-Complexity Standard: Raising Both Bars

    ERIC Educational Resources Information Center

    Williamson, Gary L.; Fitzgerald, Jill; Stenner, Jackson A.

    2014-01-01

    The Common Core State Standards (CCSS) establish a challenging text-complexity standard for all high school graduates to read at college and workplace text-complexity levels. We argue that implementation of the CCSS standard requires concurrent examination of historical student reading-growth trends. An example of a historical student average…

  17. Radiation of complex and noisy sources within enclosures

    NASA Astrophysics Data System (ADS)

    Gradoni, Gabriele; Creagh, Stephen; Tanner, Gregor

    Predicting the radiation of complex electromagnetic sources inside semi-open cavities and resonators with arbitrary geometry is a challenging topic both for physics and for engineering. We have exploited a Perron-Frobenius operator to propagate field-field correlation functions of complex and extended sources in free-space. The formula is based on a phase-space picture of the electromagnetic field, using the Wigner distribution function, and naturally captures evanescent as well as diffracted waves. This approach can be extended to study the propagation of correlation functions within cavities, with the ray-dynamical map given by the geometry of the cord connecting a point of the boundary to another. While ray methods provide an efficient way to predict average values of the correlation matrix elements, the use of random matrix theory approaches allows efficient characterisation of statistical fluctuations around these averages. Universal relations are derived and tested in the presence of dissipation for quantum maps and billiard systems. The use of this formalism is discussed in the contexts of open systems with surface roughness. The theory and achieved results are of interest in the simulation of next-generation of wireless communications. Work supported by the UK Engineering and Physical Sciences Research Council.

  18. Standard Practice for Dosimetry of Proton Beams for use in Radiation Effects Testing of Electronics

    SciTech Connect

    McMahan, Margaret A.; Blackmore, Ewart; Cascio, Ethan W.; Castaneda, Carlos; von Przewoski, Barbara; Eisen, Harvey

    2008-07-25

    Representatives of facilities that routinely deliver protons for radiation effect testing are collaborating to establish a set of standard best practices for proton dosimetry. These best practices will be submitted to the ASTM International for adoption.

  19. EVOLUTION OF THE IEC AND EN STANDARDS FOR INDIVIDUAL MONITORING OF IONISING RADIATION.

    PubMed

    Voytchev, M; Behrens, R; Ambrosi, P; Radev, R; Chiaro, P

    2016-09-01

    This article presents the evolution of the International Electrotechnical Commission (IEC) and the European standards for individual monitoring of ionising radiation issued, respectively, from the committees IEC/Sub Committee 45B and European Committee for Electro-technical Standardization/Technical Committee 45B 'Radiation protection instrumentation'. Standards for passive individual photon and beta dosimetry systems as well as those for active individual monitors are discussed. A neutron ambient dose equivalent (rate) meter standard and a technical report concerning the determination of uncertainty in measurement are also covered. PMID:26443545

  20. Radiation Standards: The Last Word or at Least a Definitive One

    ERIC Educational Resources Information Center

    Gillette, Robert

    1972-01-01

    Discusses the report of the National Academy of Science Committee on the Biological Effects of Ionizing Radiation, with particular reference to the possibilities for lowering maximum permissible standards for exposure to man-made radiation. The excessive use of diagnostic X-rays is considered. (AL)

  1. Untangling complex processes within Earth's radiation belts with the Radiation Belt Storm Probes (RBSP) mission

    NASA Astrophysics Data System (ADS)

    Mauk, B. H.; Fox, N. J.; Sibeck, D. G.; Kanekal, S. G.; Kessel, R.

    2011-12-01

    Progress towards developing a predictive understanding of Earth's dynamic radiation belts requires that we: 1) better understand individual transport and energization mechanisms, and 2) better understand how these mechanisms act together to yield the complex behaviors that are observed. An example of the former imperative is to understand the extent to which non-linearities modify the role that whistler mode waves play in exchanging energy with and scattering radiation belt electrons. However, the latter imperative represents a greater challenge. What is the relationship between processes that supply electron source populations and those that generate the Ultra Low Frequency waves that can help transport those particles? What is the role of substorm injections in creating or modifying the global electric fields that transport and redistribute the injected plasma populations? How dependent is the wave activity that energizes radiation belt electrons on the global electric field that creates the conditions for wave generation? Two characteristics of the Radiation Belt Storm Probes (RBSP) mission will enable researchers to address these interdependent mechanisms. First, the payload complement is unusually comprehensive, measuring all of the particle (electrons, ions, ion composition), fields (E and B), and wave distributions (dE and dB) needed to address the most critical science questions. However, the ability of the two RBSP spacecraft to make multiple, identical, and simultaneous measurements over a wide range of spatial scales is even more critical. RBSP comprises two spacecraft making in situ measurements for at least 2 years in nearly the same highly elliptical, low inclination orbits (1.1 x 5.8 RE, 10 degrees). The orbits are slightly different so that 1 spacecraft laps the other spacecraft about every 2.5 months, allowing separation of spatial from temporal affects over spatial scales ranging from ~0.1 to 5 RE. Here we discuss how the unique capabilities of

  2. Standard value for the radiation length in air

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    The radiation length in air, was studied. Calculations were finished and give new values for t sub o in atomic oxygen and nitrogen which are entirely free of dependence on the Thomas-Fermi approximate model. With the usual small corrections for atmospheric A and CO2, these give t sub o air = 37.15 g cm/2, in close agreement with a value recommended, but in contrast to t sub o air = 36.66 g cm/2 obtained using the Thomas-Fermi approximation.

  3. Blackbody radiation shift in the {sup 87}Rb frequency standard

    SciTech Connect

    Safronova, M. S.; Jiang Dansha; Safronova, U. I.

    2010-08-15

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature, of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in {sup 87}Rb using the relativistic all-order method and carried out a detailed evaluation of the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly excited states. Our predicted value for the Stark coefficient, k{sub S}=-1.240(4)x10{sup -10} Hz/(V/m){sup 2}, is three times more accurate than the previous calculation [E. J. Angstman, V. A. Dzuba, and V. V. Flambaum, Phys. Rev. A 74, 023405 (2006)].

  4. Standardization of terminology in field of ionizing radiations and their measurements

    NASA Astrophysics Data System (ADS)

    Yudin, M. F.; Karaveyev, F. M.

    1984-03-01

    A new standard terminology was introduced on 1 January 1982 by the Scientific-Technical Commission on All-Union State Standards to cover ionizing radiations and their measurements. It is based on earlier standards such as GOST 15484-74/81, 18445-70/73, 19849-74, 22490-77 as well as the latest recommendations by international committees. One hundred eighty-six terms and definitions in 14 paragraphs are contained. Fundamental concepts, sources and forms of ionizing radiations, characteristics and parameters of ionizing radiations, and methods of measuring their characteristics and parameters are covered. New terms have been added to existing ones. The equivalent English, French, and German terms are also given. The terms measurement of ionizing radiation and transfer of ionizing particles (equivalent of particle fluence of energy fluence) are still under discussion.

  5. A Terahertz Blackbody Radiation Standard Based on Emissivity Measurements and a Monte-Carlo Simulation

    NASA Astrophysics Data System (ADS)

    Monte, C.; Gutschwager, B.; Adibekyan, A.; Hollandt, J.

    2014-08-01

    Blackbody radiators are commonly used metrological standards of spectral radiance and radiation temperature according to Planck's law of thermal radiation. In a well defined geometry of observation they also provide calculable irradiance for the calibration of radiation detectors. Here we describe the metrological characterization of a vacuum variable-temperature blackbody to serve as a source standard for FIR- and THz radiation from 5 μm to 200 μm (60 THz to 1.5 THz). The key quantity of the characterization is the effective spectral emissivity of its cavity. This is determined by angular resolved directional spectral emissivity and directional spectral reflectivity measurements of its wall coating, Aeroglaze Z306. From the reflectivity measurements the diffusity is determined. Spectral emissivity and diffusity in combination with the well known cavity geometry allow the determination of the effective spectral cavity emissivity via a Monte-Carlo ray tracing simulation.

  6. Effects of ionizing and particle radiation on precision frequency sources (Proposal for IEEE Standards Project P1193). Technical report

    SciTech Connect

    Vig, J.R.; Audoin, C.; Cutler, L.S.; Driscoll, M.M.; EerNisse, E.P.

    1992-07-04

    The susceptibility of quartz oscillators and atomic frequency standards to natural and enhanced ionizing and particle radiation is an important parameter in predicting the short and long term performances of these standards in spacecraft. Characterization of the response of frequency standards to ionizing and particle radiation should be based on a thorough understanding of the radiation environment (proton, electron, neutron and flash x-ray radiation and single event upset) and radiation scenarios (dose/anneal cycle, combined environments). The document will present, in detail, the various forms of radiation existing or produced in the low-earth orbit and enhanced environments. In particular, emphasis will be placed on flux, fluence and dose rate levels and interaction mechanisms as pertaining to realistic radiation exposure scenarios. In addition to a discussion of radiation environments (proton, electron, neutron, flash x-ray, gamma and single event upset), selection criteria for radiation sources are presented including dosimetry and procedures for the radiation testing of frequency standards.

  7. Complex Squeezing and Force Measurement Beyond the Standard Quantum Limit

    NASA Astrophysics Data System (ADS)

    Buchmann, L. F.; Schreppler, S.; Kohler, J.; Spethmann, N.; Stamper-Kurn, D. M.

    2016-07-01

    A continuous quantum field, such as a propagating beam of light, may be characterized by a squeezing spectrum that is inhomogeneous in frequency. We point out that homodyne detectors, which are commonly employed to detect quantum squeezing, are blind to squeezing spectra in which the correlation between amplitude and phase fluctuations is complex. We find theoretically that such complex squeezing is a component of ponderomotive squeezing of light through cavity optomechanics. We propose a detection scheme called synodyne detection, which reveals complex squeezing and allows the accounting of measurement backaction. Even with the optomechanical system subject to continuous measurement, such detection allows the measurement of one component of an external force with sensitivity only limited by the mechanical oscillator's thermal occupation.

  8. The development of practice standards for radiation oncology in Australia: a tripartite approach.

    PubMed

    Kron, T; Dwyer, M; Smith, L; MacDonald, A; Pawsey, M; Raik, E; Arnold, A; Hill, B; Duchesne, G M

    2015-06-01

    In many areas of health care, practice standards have become an accepted method for professions to assess and improve the quality of care delivery. The aim of this work is to present the development of practice standards for radiation oncology in Australia, highlighting critical points and lessons learned. Following a review of radiotherapy services in Australia, a multidisciplinary group with support from the Australian Government developed practice standards for radiation oncology in Australia. The standards were produced in a multistep process including a nationwide survey of radiotherapy centres and piloting of the standards in a representative subset of all Australian radiotherapy centres. The standards are grouped into three sections: Facility management (covering staffing, data management, equipment and processes); Treatment planning and delivery (providing more detailed guidance on prescription, planning and delivery); Safety and quality management (including radiation safety, incident monitoring and clinical trials participation). Each of the 16 standards contains specific criteria, a commentary and suggestions for the evidence required to demonstrate compliance. The development of the standards was challenging and time consuming, but the collaborative efforts of the professions resulted in standards applicable throughout Australia and possibly further afield.

  9. Cost Accounting Standards: An Overview of Compliance with These Complex Standards.

    ERIC Educational Resources Information Center

    Bruce, Janet D.

    1993-01-01

    A discussion of federal cost accounting standards (CAS) chronicles briefly the history of CAS, notes other pertinent regulations applicable to higher education, summarizes the initial standards drafted for colleges and universities, and examines disclosure statement requirements and implications of noncompliance. (MSE)

  10. Radon in the Workplace: the Occupational Safety and Health Administration (OSHA) Ionizing Radiation Standard.

    PubMed

    Lewis, Robert K

    2016-10-01

    On 29 December 1970, the Occupational Safety and Health Act of 1970 established the Occupational Safety and Health Administration (OSHA). This article on OSHA, Title 29, Part 1910.1096 Ionizing Radiation standard was written to increase awareness of the employer, the workforce, state and federal governments, and those in the radon industry who perform radon testing and radon mitigation of the existence of these regulations, particularly the radon relevant aspect of the regulations. This review paper was also written to try to explain what can sometimes be complicated regulations. As the author works within the Radon Division of the Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection, the exclusive focus of the article is on radon. The 1910.1096 standard obviously covers many other aspects of radiation and radiation safety in the work place. PMID:27575350

  11. Radon in the Workplace: the Occupational Safety and Health Administration (OSHA) Ionizing Radiation Standard.

    PubMed

    Lewis, Robert K

    2016-10-01

    On 29 December 1970, the Occupational Safety and Health Act of 1970 established the Occupational Safety and Health Administration (OSHA). This article on OSHA, Title 29, Part 1910.1096 Ionizing Radiation standard was written to increase awareness of the employer, the workforce, state and federal governments, and those in the radon industry who perform radon testing and radon mitigation of the existence of these regulations, particularly the radon relevant aspect of the regulations. This review paper was also written to try to explain what can sometimes be complicated regulations. As the author works within the Radon Division of the Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection, the exclusive focus of the article is on radon. The 1910.1096 standard obviously covers many other aspects of radiation and radiation safety in the work place.

  12. Feasibility of EBT Gafchromic films for comparison exercises among standard beta radiation fields.

    PubMed

    Benavente, J A; Meira-Belo, L C; Reynaldo, S R; da Silva, T A

    2012-12-01

    The feasibility of using radiochromic films to verify the metrological coherence among standard beta radiation fields was evaluated. Exercises were done between two Brazilian metrology laboratories in beta fields from (90)Sr/(90)Y, (85)Kr and (147)Pm radiation sources. Results showed that the radiochromic film was useful for field mapping aiming uniformity and alignment verification and it was not reliable for absorbed dose measurements only for (147)Pm beta field.

  13. Risk estimates for radiation-induced cancer and radiation protection standards

    SciTech Connect

    Sinclair, W.K. )

    1989-11-01

    At low doses, the primary biological effects of concern are stochastic in nature, i.e., they are more probable at higher doses, but their severity is independent of the dose. In the last decade, a new epidemiological information on radiation-induced cancer in humans has become available. In the Japanese survivors three new cycles of data (11 yr of experience) have accumulated, and a revised dosimetry system (DS86) has been introduced. UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) reevaluated the risk of cancer from all human sources, which include other human populations such as those treated for ankylosing spondylitis and for cancer of the cervix. UNSCEAR has also evaluated the cancer risk for each of nine organs. For radiation protection purposes (low doses and dose rates, adult populations mainly), nominal values of risk since the 1977-80 period have been {approximately}1%/Sv. This value will need to be increased in the light of the new estimates. Also, risk estimates for various tissues must be reconsidered, and weighting factors used by International Commission on Radiological Protection need to be reexamined. Recommendations on occupational and public dose limits must also be reconsidered. The National Council on Radiation Protection and Measurements is in a comparatively good position with a recently produced set of recommendations that had higher cancer risk estimates in mind.

  14. Solar particle event analysis using the standard radiation environment monitors: applying the neutron monitor's experience

    NASA Astrophysics Data System (ADS)

    Papaioannou, A.; Mavromichalaki, H.; Gerontidou, M.; Souvatzoglou, G.; Nieminen, P.; Glover, A.

    2011-01-01

    The Standard Radiation Environment Monitor (SREM) is a particle detector developed by the European Space Agency for satellite applications with the main purpose to provide radiation hazard alarms to the host spacecraft. SREM units have been constructed within a radiation hardening concept and therefore are able to register extreme solar particle events (SPEs). Large SPEs are registered at Earth, by ground based detectors as neutron monitors, in the form of Ground Level Enhancements of solar cosmic rays. In this work, a feasibility study of a possible radiation alert, deduced by SREM measurements was implemented for the event of 20 January 2005. Taking advantage of the neutron monitor's experience, the steps of the GLE alert algorithm were put into practice on SREM measurements. The outcome was that SREM units did register the outgoing SPE on-time and that these could serve as indicators of radiation hazards, leading to successful alerts.

  15. Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation

    SciTech Connect

    Hazawa, Masaharu; Tomiyama, Kenichi; Saotome-Nakamura, Ai; Obara, Chizuka; Yasuda, Takeshi; Gotoh, Takaya; Tanaka, Izumi; Yakumaru, Haruko; Ishihara, Hiroshi; Tajima, Katsushi

    2014-04-18

    Highlights: • Radiation increases cellular uptake of exosomes. • Radiation induces colocalization of CD29 and CD81. • Exosomes selectively bind the CD29/CD81 complex. • Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation. - Abstract: Exosomes mediate intercellular communication, and mesenchymal stem cells (MSC) or their secreted exosomes affect a number of pathophysiologic states. Clinical applications of MSC and exosomes are increasingly anticipated. Radiation therapy is the main therapeutic tool for a number of various conditions. The cellular uptake mechanisms of exosomes and the effects of radiation on exosome–cell interactions are crucial, but they are not well understood. Here we examined the basic mechanisms and effects of radiation on exosome uptake processes in MSC. Radiation increased the cellular uptake of exosomes. Radiation markedly enhanced the initial cellular attachment to exosomes and induced the colocalization of integrin CD29 and tetraspanin CD81 on the cell surface without affecting their expression levels. Exosomes dominantly bound to the CD29/CD81 complex. Knockdown of CD29 completely inhibited the radiation-induced uptake, and additional or single knockdown of CD81 inhibited basal uptake as well as the increase in radiation-induced uptake. We also examined possible exosome uptake processes affected by radiation. Radiation-induced changes did not involve dynamin2, reactive oxygen species, or their evoked p38 mitogen-activated protein kinase-dependent endocytic or pinocytic pathways. Radiation increased the cellular uptake of exosomes through CD29/CD81 complex formation. These findings provide essential basic insights for potential therapeutic applications of exosomes or MSC in combination with radiation.

  16. Cosmic strings in hidden sectors: 1. Radiation of standard model particles

    SciTech Connect

    Long, Andrew J.; Hyde, Jeffrey M.; Vachaspati, Tanmay E-mail: jmhyde@asu.edu

    2014-09-01

    In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant cosmic strings to Standard Model particles. We calculate the spectrum of radiation emitted by these ''dark strings'' in the form of Higgs bosons, Z bosons, and Standard Model fermions assuming that string tension is above the TeV scale. We also calculate the scattering cross sections of Standard Model fermions on dark strings due to the Aharonov-Bohm interaction. These radiation and scattering calculations will be applied in a subsequent paper to study the cosmological evolution and observational signatures of dark strings.

  17. A complex standard for protein identification, designed by evolution.

    PubMed

    Vaudel, Marc; Burkhart, Julia M; Breiter, Daniela; Zahedi, René P; Sickmann, Albert; Martens, Lennart

    2012-10-01

    Shotgun proteomic investigations rely on the algorithmic assignment of mass spectra to peptides. The quality of these matches is therefore a cornerstone in the analysis and has been the subject of numerous recent developments. In order to establish the benefits of novel algorithms, they are applied to reference samples of known content. However, these were recently shown to be either too simple to resemble typical real-life samples or as leading to results of lower accuracy as the method itself. Here, we describe how to use the proteome of Pyrococcus furiosus , a hyperthermophile, as a standard to evaluate proteomics identification workflows. Indeed, we prove that the Pyrococcus furiosus proteome provides a valid method for detecting random hits, comparable to the decoy databases currently in popular use, but we also prove that the Pyrococcus furiosus proteome goes squarely beyond the decoy approach by also providing many hundreds of highly reliable true positive hits. Searching the Pyrococcus furiosus proteome can thus be used as a unique test that provides the ability to reliably detect both false positives as well as proteome-scale true positives, allowing the rigorous testing of identification algorithms at the peptide and protein level.

  18. Visualization of a Deterministic Radiation Transport Model Using Standard Visualization Tools

    SciTech Connect

    James A. Galbraith; L. Eric Greenwade

    2004-05-01

    Output from a deterministic radiation transport code running on a CRAY SV1 is imported into a standard distributed, parallel, visualization tool for analysis. Standard output files, consisting of tetrahedral meshes, are imported to the visualization tool through the creation of a application specific plug-in module. Visualization samples are included, providing visualization of steady state results. Different plot types and operators are utilized to enhance the analysis and assist in reporting the results of the analysis.

  19. Two-loop stability of a complex singlet extended standard model

    NASA Astrophysics Data System (ADS)

    Costa, Raul; Morais, António P.; Sampaio, Marco O. P.; Santos, Rui

    2015-07-01

    Motivated by the dark matter and the baryon asymmetry problems, we analyze a complex singlet extension of the Standard Model with a Z2 symmetry (which provides a dark matter candidate). After a detailed two-loop calculation of the renormalization group equations for the new scalar sector, we study the radiative stability of the model up to a high energy scale (with the constraint that the 126 GeV Higgs boson found at the LHC is in the spectrum) and find it requires the existence of a new scalar state mixing with the Higgs with a mass larger than 140 GeV. This bound is not very sensitive to the cutoff scale as long as the latter is larger than 1010 GeV . We then include all experimental and observational constraints/measurements from collider data, from dark matter direct detection experiments, and from the Planck satellite and in addition force stability at least up to the grand unified theory scale, to find that the lower bound is raised to about 170 GeV, while the dark matter particle must be heavier than about 50 GeV.

  20. On the standard conjecture of Lefschetz type for complex projective threefolds. II

    NASA Astrophysics Data System (ADS)

    Tankeev, Sergei G.

    2011-10-01

    We show that Grothendieck's standard conjecture of Lefschetz type on the algebraicity of the operators \\ast and \\Lambda of Hodge theory holds for all smooth complex projective threefolds of Kodaira dimension \\varkappa<3.

  1. Generating Automated Text Complexity Classifications That Are Aligned with Targeted Text Complexity Standards. Research Report. ETS RR-10-28

    ERIC Educational Resources Information Center

    Sheehan, Kathleen M.; Kostin, Irene; Futagi, Yoko; Flor, Michael

    2010-01-01

    The Common Core Standards call for students to be exposed to a much greater level of text complexity than has been the norm in schools for the past 40 years. Textbook publishers, teachers, and assessment developers are being asked to refocus materials and methods to ensure that students are challenged to read texts at steadily increasing…

  2. Complex Text and New Common Standards in the United States: Pedagogical Implications for English Learners

    ERIC Educational Resources Information Center

    Bunch, George C.; Walqui, Aída; Pearson, P. David

    2014-01-01

    In the United States, new common state standards in English language arts and disciplinary literacy require K-12 students to "read and comprehend complex literary and informational texts independently and proficiently." Issues of text complexity have spurred debates in the mainstream literacy, educational practice, and policy…

  3. Challenging the Research Base of the Common Core State Standards: A Historical Reanalysis of Text Complexity

    ERIC Educational Resources Information Center

    Gamson, David A.; Lu, Xiaofei; Eckert, Sarah Anne

    2013-01-01

    The widely adopted Common Core State Standards (CCSS) call for raising the level of text complexity in textbooks and reading materials used by students across all grade levels in the United States; the authors of the English Language Arts component of the CCSS build their case for higher complexity in part upon a research base they say shows a…

  4. Radiation method for determining brine tolerant surfactants in complex mixtures

    SciTech Connect

    Schmitt, K. D.

    1984-12-11

    This invention provides a method for determining the concentration of a brine tolerant sulfonate surfactant in a complex mixture containing, in addition to said brine tolerant sulfonate surfactant, lignosulfonates, crude oil, salts, and water and, optionally, petroleum sulfonates and alcohols, that comprises incorporating into the brine tolerant sulfonate surfactant molecule a small amount of tritium prior to addition to the complex mixture and determining the concentration of the brine tolerant sulfonate surfactant by measuring its radioactivity.

  5. Evaluation of Breast Sentinel Lymph Node Coverage by Standard Radiation Therapy Fields

    SciTech Connect

    Rabinovitch, Rachel Ballonoff, Ari; Newman, Francis M.S.; Finlayson, Christina

    2008-04-01

    Background: Biopsy of the breast sentinel lymph node (SLN) is now a standard staging procedure for early-stage invasive breast cancer. The anatomic location of the breast SLN and its relationship to standard radiation fields has not been described. Methods and Materials: A retrospective review of radiotherapy treatment planning data sets was performed in patients with breast cancer who had undergone SLN biopsy, and those with a surgical clip at the SLN biopsy site were identified. The location of the clip was evaluated relative to vertebral body level on an anterior-posterior digitally reconstructed radiograph, treated whole-breast tangential radiation fields, and standard axillary fields in 106 data sets meeting these criteria. Results: The breast SLN varied in vertebral body level position, ranging from T2 to T7 but most commonly opposite T4. The SLN clip was located below the base of the clavicle in 90%, and hence would be excluded from standard axillary radiotherapy fields where the inferior border is placed at this level. The clip was within the irradiated whole-breast tangent fields in 78%, beneath the superior-posterior corner multileaf collimators in 12%, and outside the tangent field borders in 10%. Conclusions: Standard axillary fields do not encompass the lymph nodes at highest risk of containing tumor in breast cancer patients. Elimination of the superior-posterior corner MLCs from the tangent field design would result in inclusion of the breast SLN in 90% of patients treated with standard whole-breast irradiation.

  6. Standardization Process for Space Radiation Models Used for Space System Design

    NASA Technical Reports Server (NTRS)

    Barth, Janet; Daly, Eamonn; Brautigam, Donald

    2005-01-01

    The space system design community has three concerns related to models of the radiation belts and plasma: 1) AP-8 and AE-8 models are not adequate for modern applications; 2) Data that have become available since the creation of AP-8 and AE-8 are not being fully exploited for modeling purposes; 3) When new models are produced, there is no authorizing organization identified to evaluate the models or their datasets for accuracy and robustness. This viewgraph presentation provided an overview of the roadmap adopted by the Working Group Meeting on New Standard Radiation Belt and Space Plasma Models.

  7. Development of a proposed international standard for certification of aircraft to High Intensity Radiated Fields (HIRF)

    NASA Technical Reports Server (NTRS)

    Sargent, Noel B.

    1993-01-01

    Avionic systems performing critical functions in modern aircraft are potentially susceptible to the hazards of electromagnetic radiation from ground and airborne transmitters. The Federal Aviation Administration (FAA) requested that the Society of Automotive Engineers (SAE) coordinate the development of procedures and guidance material which can be used during the aircraft certification process to ensure adequate protection against high intensity radiated fields (HIRF). This paper addresses both the technical challenge of drafting a certification procedure and guidance standard as well as the management process used by the SAE subcommittee AE4R to converge a diverse range of opinions by its international membership in the shortest possible time.

  8. 76 FR 4944 - Ionizing Radiation Standard; Extension of the Office of Management and Budget's (OMB) Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-27

    .... 3506 et seq.) and Secretary of Labor's Order No. 4-2010 (75 FR 55355). Signed at Washington, DC, on... Occupational Safety and Health Administration Ionizing Radiation Standard; Extension of the Office of... requirements specified in the Ionizing Radiation Standard (29 CFR 1910.1096). The information...

  9. Toxic variability and radiation potentiation by Rh(III) complexes in Salmonella typhimurium cells

    SciTech Connect

    Richmond, R.C.; O'Hara, J.; Picker, D.H.; Douple, E.B.

    1986-12-01

    Stationary-phase cells of Salmonella typhimurium were irradiated in phosphate-buffered saline in the presence of rhodium complexes to test for the potentiation of radiation-induced cell killing. Eleven Rh complexes, two Rh(I) and nine Rh(III), were tested. Seven Rh(III) complexes were found to be radiation potentiators; six potentiate only under hypoxic conditions, and one potentiates under both hypoxic and oxic conditions. Four of these seven Rh(III) complexes demonstrate potentiation that is 2 to 13 times greater than the sensitization caused by oxygen. Irradiating cells in Ham's F-12 culture medium rather than in phosphate-buffered saline eliminates this latter hypoxic radiation potentiation. None of the seven Rh(III) radiation potentiators are directly toxic to cells. However, four complexes were tested for hypoxic radiation-induced cytocidal toxicity, and three were found to be toxic after irradiation. The efficiency of this toxicity is not sufficient to account for the observed radiation potentiation. It is suggested that both reductive and oxidative free radical events are involved in the spectrum of Rh(III) potentiation observed.

  10. Impact of complexity and computer control on errors in radiation therapy.

    PubMed

    Fraass, B A

    2012-01-01

    A number of recent publications in both the lay and scientific press have described major errors in patient radiation treatments, and this publicity has galvanised much work to address and mitigate potential safety issues throughout the radiation therapy planning and delivery process. The complexity of modern radiotherapy techniques and equipment, including computer-controlled treatment machines and treatment management systems, as well as sophisticated treatment techniques that involve intensity-modulated radiation therapy, image-guided radiation therapy, stereotactic body radiation therapy, volumetric modulated arc therapy, respiratory gating, and others, leads to concern about safety issues related to that complexity. This article illustrates the relationship between complexity and computer control, and various safety problems and errors that have been reported, and describes studies that address the issue of these modern techniques and whether their complexity does, in fact, result in more errors or safety-related problems. Clinical implications of these results are discussed, as are some of the ways in which the field should respond to the ongoing concerns about errors and complexity in radiation therapy. PMID:23089018

  11. Wave field synthesis of moving virtual sound sources with complex radiation properties.

    PubMed

    Ahrens, Jens; Spors, Sascha

    2011-11-01

    An approach to the synthesis of moving virtual sound sources with complex radiation properties in wave field synthesis is presented. The approach exploits the fact that any stationary sound source of finite spatial extent radiates spherical waves at sufficient distance. The angular dependency of the radiation properties of the source under consideration is reflected by the amplitude and phase distribution on the spherical wave fronts. The sound field emitted by a uniformly moving monopole source is derived and the far-field radiation properties of the complex virtual source under consideration are incorporated in order to derive a closed-form expression for the loudspeaker driving signal. The results are illustrated via numerical simulations of the synthesis of the sound field of a sample moving complex virtual source.

  12. Methods of treating complex space vehicle geometry for charged particle radiation transport

    NASA Technical Reports Server (NTRS)

    Hill, C. W.

    1973-01-01

    Current methods of treating complex geometry models for space radiation transport calculations are reviewed. The geometric techniques used in three computer codes are outlined. Evaluations of geometric capability and speed are provided for these codes. Although no code development work is included several suggestions for significantly improving complex geometry codes are offered.

  13. [Active radiation telethermometry in the complex diagnosis of ovarian tumors].

    PubMed

    Hozhenko, A I; Peresun'ko, O P; Orenchuk, V S; Vysochyna, K V

    1999-07-01

    An active remote radiation thermometry was used in the diagnosis and differential diagnosis of ovarian tumours by determining the heat flow from the area of projection of the ovaries and control background. Overall fourty three patients with ovarian tumours were examined by this method. Significance of the results secured was verified during the histological technique-aided operation. The authors have come to the conclusion that remote thermometry involving loading tests is a simple supplementary method of investigation that is helpful in diagnosing of both benign and malignant ovarian tumours.

  14. Design of organic scintillators for non-standard radiation field dosimetry: experimental setup.

    PubMed

    Norman H, Machado R; Maximiliano, Trujillo T; Javier E, García G; Diana C, Narvaez G; Paula A, Marín M; Róbinson A, Torres V

    2013-01-01

    This paper describes an experimental setup designed for sensing the luminescent light coming from an organic plastic scintillator stimulated with ionizing radiation. This device is intended to be a part of a complete dosimeter system for characterization of small radiation fields which is the project of the doctoral thesis of the medical physicist at the Radiation Oncology facility of Hospital San Vicente Fundación in conjunction with the Universidad de Antioquia of Medellín Colombia. Some preliminary results predict a good performance of the unit, but further studies must be conducted in order to have a completed evaluation of the system. This is the first step in the development of an accuracy tool for measurement of non-standard fields in the Radiotherapy or Radiosurgery processes. PMID:24110369

  15. Cooling systems and hybrid A/C systems using an electromagnetic radiation-absorbing complex

    DOEpatents

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    2015-05-19

    A method for powering a cooling unit. The method including applying electromagnetic (EM) radiation to a complex, where the complex absorbs the EM radiation to generate heat, transforming, using the heat generated by the complex, a fluid to vapor, and sending the vapor from the vessel to a turbine coupled to a generator by a shaft, where the vapor causes the turbine to rotate, which turns the shaft and causes the generator to generate the electric power, wherein the electric powers supplements the power needed to power the cooling unit

  16. Modern Palliative Radiation Treatment: Do Complexity and Workload Contribute to Medical Errors?

    SciTech Connect

    D'Souza, Neil; Holden, Lori; Robson, Sheila; Mah, Kathy; Di Prospero, Lisa; Wong, C. Shun; Chow, Edward; Spayne, Jacqueline

    2012-09-01

    Purpose: To examine whether treatment workload and complexity associated with palliative radiation therapy contribute to medical errors. Methods and Materials: In the setting of a large academic health sciences center, patient scheduling and record and verification systems were used to identify patients starting radiation therapy. All records of radiation treatment courses delivered during a 3-month period were retrieved and divided into radical and palliative intent. 'Same day consultation, planning and treatment' was used as a proxy for workload and 'previous treatment' and 'multiple sites' as surrogates for complexity. In addition, all planning and treatment discrepancies (errors and 'near-misses') recorded during the same time frame were reviewed and analyzed. Results: There were 365 new patients treated with 485 courses of palliative radiation therapy. Of those patients, 128 (35%) were same-day consultation, simulation, and treatment patients; 166 (45%) patients had previous treatment; and 94 (26%) patients had treatment to multiple sites. Four near-misses and 4 errors occurred during the audit period, giving an error per course rate of 0.82%. In comparison, there were 10 near-misses and 5 errors associated with 1100 courses of radical treatment during the audit period. This translated into an error rate of 0.45% per course. An association was found between workload and complexity and increased palliative therapy error rates. Conclusions: Increased complexity and workload may have an impact on palliative radiation treatment discrepancies. This information may help guide the necessary recommendations for process improvement for patients who require palliative radiation therapy.

  17. Influence of inhomogeneous damping distribution on sound radiation properties of complex vibration modes in rectangular plates

    NASA Astrophysics Data System (ADS)

    Unruh, Oliver

    2016-09-01

    In order to reduce noise emitted by vibrating structures additional damping treatments such as constraint layer damping or embedded elastomer layers can be used. To save weight and cost, the additional damping is often placed at some critical locations of the structure, what leads to spatially inhomogeneous distribution of damping. This inhomogeneous distribution of structural damping leads to an occurrence of complex vibration modes, which are no longer dominated by pure standing waves, but by a superposition of travelling and standing waves. The existence of complex vibration modes raises the question about their influence on sound radiation. Previous studies on the sound radiation of complex modes of rectangular plates reveal, that, depending on the direction of travelling waves, the radiation efficiency of structural modes can slightly decrease or significantly increase. These observations have been made using a rectangular plate with a simple inhomogeneous damping configuration which includes a single plate boundary with a higher structural damping ratio. In order to answer the question about the influence of other possible damping configurations on the sound radiation properties, this paper addresses the self- and mutual-radiation efficiencies of the resulting complex vibration modes. Numerical simulations are used for the calculation of complex structural modes of different inhomogeneous damping configurations with varying geometrical form and symmetry. The evaluation of self- and mutual-radiation efficiencies reveals that primarily the symmetry properties of the inhomogeneous damping distribution affect the sound radiation characteristics. Especially the asymmetric distributions of inhomogeneous damping show a high influence on the investigated acoustic metrics. The presented study also reveals that the acoustic cross-coupling between structural modes, which is described by the mutual-radiation efficiencies, generally increases with the presence of

  18. ANSI and IEC standards for, and evaluation of, radiation detection instrumentation

    SciTech Connect

    Chiaro Jr, Peter John

    2008-01-01

    During the last quarter of 2002, an effort was started to develop performance requirements for radiation instrumentation used for the detection of illicit trafficking of radioactive material. Coordinated by the US National Institute of Science and Technology (NIST), a team was formed to establish writing committees for the development of these requirements as American National Standards Institute (ANSI) standards. The core of the new area was developed as ANSI N42, Homeland Security Instruments. A series of standards were developed followed by testing and evaluation (T&E) protocols that would be used for specific testing. Four US National Laboratories provided T&E support and work commenced to test instruments provided by manufacturers at no cost. During this time, discussions began regarding the formation of a new work group within the International Electrotechnical Commission (IEC). This new work group would be located within technical committee (TC) 45 which addresses nuclear instrumentation. This new work group, 15B, also began developing international standards to address the same instrument types. Following development of ANSI standards, the testing and evaluation process began, running for two distinct rounds. The results of the work was consolidated by NIST and released back to individual companies as well as the user community in a controlled manner. This document will provide details regarding the standards and their basis and status, as well as some information regarding the T&E process used in the USA.

  19. MO-G-9A-01: Imaging Refresher for Standard of Care Radiation Therapy

    SciTech Connect

    Labby, Z; Sensakovic, W; Hipp, E; Altman, M

    2014-06-15

    Imaging techniques and technology which were previously the domain of diagnostic medicine are becoming increasingly integrated and utilized in radiation therapy (RT) clinical practice. As such, there are a number of specific imaging topics that are highly applicable to modern radiation therapy physics. As imaging becomes more widely integrated into standard clinical radiation oncology practice, the impetus is on RT physicists to be informed and up-to-date on those imaging modalities relevant to the design and delivery of therapeutic radiation treatments. For example, knowing that, for a given situation, a fluid attenuated inversion recovery (FLAIR) image set is most likely what the physician would like to import and contour is helpful, but may not be sufficient to providing the best quality of care. Understanding the physics of how that pulse sequence works and why it is used could help assess its utility and determine if it is the optimal sequence for aiding in that specific clinical situation. It is thus important that clinical medical physicists be able to understand and explain the physics behind the imaging techniques used in all aspects of clinical radiation oncology practice. This session will provide the basic physics for a variety of imaging modalities for applications that are highly relevant to radiation oncology practice: computed tomography (CT) (including kV, MV, cone beam CT [CBCT], and 4DCT), positron emission tomography (PET)/CT, magnetic resonance imaging (MRI), and imaging specific to brachytherapy (including ultrasound and some brachytherapy specific topics in MR). For each unique modality, the image formation process will be reviewed, trade-offs between image quality and other factors (e.g. imaging time or radiation dose) will be clarified, and typically used cases for each modality will be introduced. The current and near-future uses of these modalities and techniques in radiation oncology clinical practice will also be discussed. Learning

  20. Analysis of thermal radiation in ion traps for optical frequency standards

    NASA Astrophysics Data System (ADS)

    Doležal, M.; Balling, P.; Nisbet-Jones, P. B. R.; King, S. A.; Jones, J. M.; Klein, H. A.; Gill, P.; Lindvall, T.; Wallin, A. E.; Merimaa, M.; Tamm, C.; Sanner, C.; Huntemann, N.; Scharnhorst, N.; Leroux, I. D.; Schmidt, P. O.; Burgermeister, T.; Mehlstäubler, T. E.; Peik, E.

    2015-12-01

    In many of the high-precision optical frequency standards with trapped atoms or ions that are under development to date, the ac Stark shift induced by thermal radiation leads to a major contribution to the systematic uncertainty. We present an analysis of the inhomogeneous thermal environment experienced by ions in various types of ion traps. Finite element models which allow the determination of the temperature of the trap structure and the temperature of the radiation were developed for five ion trap designs, including operational traps at PTB and NPL and further optimized designs. Models were refined based on comparison with infrared camera measurement until an agreement of better than 10% of the measured temperature rise at critical test points was reached. The effective temperature rises of the radiation seen by the ion range from 0.8 K to 2.1 K at standard working conditions. The corresponding fractional frequency shift uncertainties resulting from the uncertainty in temperature are in the 10-18 range for optical clocks based on the Sr+ and Yb+ E2 transitions, and even lower for Yb+ E3, In+ and Al+. Issues critical for heating of the trap structure and its predictability were identified and design recommendations developed.

  1. Standard thermodynamic functions of Co2+ complexation with glycine and L-histidine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2016-02-01

    The enthalpies of the reactions between solutions of Co(NO3)2 and solutions of glycine (Gly) and L-histidine (His) are determined via direct calorimetry at different pH values and metal: ligand ratios using KNO3 as a background electrolyte ( T = 298.15 K, I = 0.2-1.0). The enthalpy changes upon the formation of cobalt glycinate complexes and Co2+ mixed-ligand complex, viz., glycine-L-histidine, were calculated. The standard thermodynamic parameters (Δr H°, Δr G°, Δr S°) of complexation are determined. The CoGlyHis complex is shown to be stable toward decomposition into homogeneous complexes.

  2. The Relationship between Students' Performance on Conventional Standardized Mathematics Assessments and Complex Mathematical Modeling Problems

    ERIC Educational Resources Information Center

    Kartal, Ozgul; Dunya, Beyza Aksu; Diefes-Dux, Heidi A.; Zawojewski, Judith S.

    2016-01-01

    Critical to many science, technology, engineering, and mathematics (STEM) career paths is mathematical modeling--specifically, the creation and adaptation of mathematical models to solve problems in complex settings. Conventional standardized measures of mathematics achievement are not structured to directly assess this type of mathematical…

  3. Average radiation dose in standard CT examinations of the head: results of the 1990 NEXT survey.

    PubMed

    Conway, B J; McCrohan, J L; Antonsen, R G; Rueter, F G; Slayton, R J; Suleiman, O H

    1992-07-01

    In 1990, as part of the Nationwide Evaluation of X-ray Trends (NEXT) program, 252 computed tomographic (CT) systems were evaluated to measure radiation doses associated with standard head CT in adults. The multiple-scan average dose (MSAD) was used as the dose descriptor. For most of the systems, the MSAD at the midpoint on the central axis of a standard dosimetry phantom was between 34 and 55 mGy. Doses were as high as 140 mGy, and dose sometimes varied by a factor of two or more for identical CT units. This range indicates that dose can potentially be reduced by careful selection of standard CT techniques. Users of CT systems should be aware of radiation dose delivered with CT, dose ranges associated with different systems, and doses delivered with their particular unit, which requires that dose performance of CT systems be assessed by means of a protocol that allows comparison of data collected for identical and/or different units.

  4. Standard thermodynamic functions of complex formation between Cu2+ and glycine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2013-05-01

    Heat effects of the interaction of copper(II) solutions with aminoacetic acid (glycine) are measured by the direct calorimetry at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against a background of potassium nitrate. Standard enthalpy values for reactions of the formation of aminoacetic acid copper complexes in aqueous solutions are obtained using an equation with a single individual parameter by extrapolating it to zero ionic strength. The standard thermodynamic characteristics of complex formation in the Cu2+-glycine system are calculated. It is shown that glycine-like coordination is most likely in Cu(II) complexes with L-asparagine, L-glutamine, and L-valine.

  5. Radiated radiofrequency immunity testing of automated external defibrillators - modifications of applicable standards are needed

    PubMed Central

    2011-01-01

    Background We studied the worst-case radiated radiofrequency (RF) susceptibility of automated external defibrillators (AEDs) based on the electromagnetic compatibility (EMC) requirements of a current standard for cardiac defibrillators, IEC 60601-2-4. Square wave modulation was used to mimic cardiac physiological frequencies of 1 - 3 Hz. Deviations from the IEC standard were a lower frequency limit of 30 MHz to explore frequencies where the patient-connected leads could resonate. Also testing up to 20 V/m was performed. We tested AEDs with ventricular fibrillation (V-Fib) and normal sinus rhythm signals on the patient leads to enable testing for false negatives (inappropriate "no shock advised" by the AED). Methods We performed radiated exposures in a 10 meter anechoic chamber using two broadband antennas to generate E fields in the 30 - 2500 MHz frequency range at 1% frequency steps. An AED patient simulator was housed in a shielded box and delivered normal and fibrillation waveforms to the AED's patient leads. We developed a technique to screen ECG waveforms stored in each AED for electromagnetic interference at all frequencies without waiting for the long cycle times between analyses (normally 20 to over 200 s). Results Five of the seven AEDs tested were susceptible to RF interference, primarily at frequencies below 80 MHz. Some induced errors could cause AEDs to malfunction and effectively inhibit operator prompts to deliver a shock to a patient experiencing lethal fibrillation. Failures occurred in some AEDs exposed to E fields between 3 V/m and 20 V/m, in the 38 - 50 MHz range. These occurred when the patient simulator was delivering a V-Fib waveform to the AED. Also, we found it is not possible to test modern battery-only-operated AEDs for EMI using a patient simulator if the IEC 60601-2-4 defibrillator standard's simulated patient load is used. Conclusions AEDs experienced potentially life-threatening false-negative failures from radiated RF, primarily

  6. Beyond the Standard Curriculum: A Review of Available Opportunities for Medical Students to Prepare for a Career in Radiation Oncology

    SciTech Connect

    Agarwal, Ankit; DeNunzio, Nicholas J.; Ahuja, Divya; Hirsch, Ariel E.

    2014-01-01

    Purpose: To review currently available opportunities for medical students to supplement their standard medical education to prepare for a career in radiation oncology. Methods and Materials: Google and PubMed were used to identify existing clinical, health policy, and research programs for medical students in radiation oncology. In addition, results publicly available by the National Resident Matching Program were used to explore opportunities that successful radiation oncology applicants pursued during their medical education, including obtaining additional graduate degrees. Results: Medical students can pursue a wide variety of opportunities before entering radiation oncology. Several national specialty societies, such as the American Society for Radiation Oncology and the Radiological Society of North America, offer summer internships for medical students interested in radiation oncology. In 2011, 30% of allopathic senior medical students in the United States who matched into radiation oncology had an additional graduate degree, including PhD, MPH, MBA, and MA degrees. Some medical schools are beginning to further integrate dedicated education in radiation oncology into the standard 4-year medical curriculum. Conclusions: To the authors' knowledge, this is the first comprehensive review of available opportunities for medical students interested in radiation oncology. Early exposure to radiation oncology and additional educational training beyond the standard medical curriculum have the potential to create more successful radiation oncology applicants and practicing radiation oncologists while also promoting the growth of the field. We hope this review can serve as guide to radiation oncology applicants and mentors as well as encourage discussion regarding initiatives in radiation oncology opportunities for medical students.

  7. Hypofractionated Versus Standard Radiation Therapy With or Without Temozolomide for Older Glioblastoma Patients

    SciTech Connect

    Arvold, Nils D.; Aizer, Ayal A.; Chiocca, E. Antonio

    2015-06-01

    Purpose: Older patients with newly diagnosed glioblastoma have poor outcomes, and optimal treatment is controversial. Hypofractionated radiation therapy (HRT) is frequently used but has not been compared to patients receiving standard fractionated radiation therapy (SRT) and temozolomide (TMZ). Methods and Materials: We conducted a retrospective analysis of patients ≥65 years of age who received radiation for the treatment of newly diagnosed glioblastoma from 1994 to 2013. The distribution of clinical covariates across various radiation regimens was analyzed for possible selection bias. Survival was calculated using the Kaplan-Meier method. Comparison of hypofractionated radiation (typically, 40 Gy/15 fractions) versus standard fractionation (typically, 60 Gy/30 fractions) in the setting of temozolomide was conducted using Cox regression and propensity score analysis. Results: Patients received SRT + TMZ (n=57), SRT (n=35), HRT + TMZ (n=34), or HRT (n=9). Patients receiving HRT were significantly older (median: 79 vs 69 years of age; P<.001) and had worse baseline performance status (P<.001) than those receiving SRT. On multivariate analysis, older age (adjusted hazard ratio [AHR]: 1.06; 95% confidence interval [CI]: 1.01-1.10, P=.01), lower Karnofsky performance status (AHR: 1.02; 95% CI: 1.01-1.03; P=.01), multifocal disease (AHR: 2.11; 95% CI: 1.23-3.61, P=.007), and radiation alone (vs SRT + TMZ; SRT: AHR: 1.72; 95% CI: 1.06-2.79; P=.03; HRT: AHR: 3.92; 95% CI: 1.44-10.60, P=.007) were associated with decreased overall survival. After propensity score adjustment, patients receiving HRT with TMZ had similar overall survival compared with those receiving SRT with TMZ (AHR: 1.10, 95% CI: 0.50-2.4, P=.82). Conclusions: With no randomized data demonstrating equivalence between HRT and SRT in the setting of TMZ for glioblastoma, significant selection bias exists in the implementation of HRT. Controlling for this bias, we observed similar overall

  8. National Institute of Standards and Technology Synchrotron Radiation Facilities for Materials Science

    PubMed Central

    Long, Gabrielle G.; Allen, Andrew J.; Black, David R.; Burdette, Harold E.; Fischer, Daniel A.; Spal, Richard D.; Woicik, Joseph C.

    2001-01-01

    Synchrotron Radiation Facilities, supported by the Materials Science and Engineering Laboratory of the National Institute of Standards and Technology, include beam stations at the National Synchrotron Light Source at Brookhaven National Laboratory and at the Advanced Photon Source at Argonne National Laboratory. The emphasis is on materials characterization at the microstructural and at the atomic and molecular levels, where NIST scientists, and researchers from industry, universities and government laboratories perform state-of-the-art x-ray measurements on a broad range of materials. PMID:27500070

  9. Atomic and Molecular Complex Resonances from Real Eigenvalues Using Standard (Hermitian) Electronic Structure Calculations.

    PubMed

    Landau, Arie; Haritan, Idan; Kaprálová-Žd'ánská, Petra Ruth; Moiseyev, Nimrod

    2016-05-19

    Complex eigenvalues, resonances, play an important role in a large variety of fields in physics and chemistry. For example, in cold molecular collision experiments and electron scattering experiments, autoionizing and predissociative metastable resonances are generated. However, the computation of complex resonance requires modifications of standard electronic structure codes and methods, which are not always straightforward, in addition, application of complex codes requires more computational efforts. Here we show how resonance eigenvalues, positions and widths, can be calculated using the standard, widely used, electronic-structure packages. Our method enables the calculations of the complex resonance eigenvalues by using analytical continuation procedures (such as Padé). The key point in our approach is the existence of narrow analytical passages from the real axis to the complex energy plane. In fact, the existence of these analytical passages relies on using finite basis sets. These passages become narrower as the basis set becomes more complete, whereas in the exact limit, these passages to the complex plane are closed. As illustrative numerical examples we calculated the autoionization Feshbach resonances of helium, hydrogen anion, and hydrogen molecule. We show that our results are in an excellent agreement with the results obtained by other theoretical methods and with available experimental results.

  10. Kolmogorov Complexity Spectrum for Use in Analysis of Uv-B Radiation Time Series

    NASA Astrophysics Data System (ADS)

    Mihailović, Dragutin T.; Malinović-Milićević, Slavica; Arsenić, Ilija; Drešković, Nusret; Bukosa, Beata

    2013-10-01

    In this paper, we have used the Kolmogorov complexity and sample entropy measures to estimate the complexity of the UV-B radiation time series in the Vojvodina region (Serbia) for the period 1990-2007. We have defined the Kolmogorov complexity spectrum and have introduced the Kolmogorov complexity spectrum highest value (KCH). We have established the UV-B radiation time series on the basis of their daily sum (dose) for seven representative places in this region using: (i) measured data, (ii) data calculated via a derived empirical formula and (iii) data obtained by a parametric UV radiation model. We have calculated the Kolmogorov complexity (KC) based on the Lempel-Ziv algorithm (LZA), KCH and sample entropy (SE) values for each time series. We have divided the period 1990-2007 into two subintervals: (i) 1990-1998 and (ii) 1999-2007 and calculated the KC, KCH and SE values for the various time series in these subintervals. It is found that during the period 1999-2007, there is a decrease in the KC, KCH and SE, compared to the period 1990-1998. This complexity loss may be attributed to (i) the increased human intervention in the post civil war period causing increase of the air pollution and (ii) the increased cloudiness due to climate changes.

  11. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., App. F Appendix F to Part 75—Standards for Licensing Radiographers, Nuclear Medicine Technologists... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  12. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., App. F Appendix F to Part 75—Standards for Licensing Radiographers, Nuclear Medicine Technologists... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  13. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., App. F Appendix F to Part 75—Standards for Licensing Radiographers, Nuclear Medicine Technologists... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  14. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., App. F Appendix F to Part 75—Standards for Licensing Radiographers, Nuclear Medicine Technologists... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  15. 42 CFR Appendix F to Part 75 - Standards for Licensing Radiographers, Nuclear Medicine Technologists, and Radiation Therapy...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Medicine Technologists, and Radiation Therapy Technologists F Appendix F to Part 75 Public Health PUBLIC..., App. F Appendix F to Part 75—Standards for Licensing Radiographers, Nuclear Medicine Technologists... licensed as Radiographers, Nuclear Medicine Technologists, or Radiation Therapy Technologists. 2....

  16. Scaling and parameterization of clear-sky solar radiation over complex topography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solar radiation at the land surface is influenced by slope, aspect, shadows, and obstruction of the sky, all of which vary over a wide range of length scales in regions of complex topography, with important consequences for the surface energy balance. Atmospheric models, however, generally assume t...

  17. Combined micro-and standard percutaneous nephrolithotomy for complex renal calculi

    PubMed Central

    Buldu, İbrahim; Tepeler, Abdulkadir; Karatağ, Tuna; İnan, Ramazan; Armağan, Abdullah; İstanbulluoğlu, Okan

    2016-01-01

    Objective We aimed to present the technique of combination of standard percutaneous nephrolithotomy (PNL) with microperc for achieving higher success rates without increasing complication rates in the management of complex renal calculi. Material and methods The patients who underwent microperc procedure as a complementary procedure to standard PNL for complex kidney stones in two reference hospitals between 2013 and 2015, were evaluated retrospectively. Results All patients underwent a total of two accesses one for standard PNL and one for microperc. The mean stone size was measured as 54.3 mm. The procedures were completed after an average operative time of 88.2 minutes and fluoroscopy time of 5.3 minutes. Stone free status was achieved in 18 cases (78.2%) and small residual fragments (≤4 mm) were detected in 3 cases (13.1%). Complications were seen in three patients (13%) as hemorrhage in one and postoperative fever in two patients. Conclusion Despite the limitations of this study, the combination of standard PNL and microperc might reduce the complication rates and increase the success rates when treating complex kidney stones. Future prospective and comparative studies are needed. PMID:27635289

  18. Combined micro-and standard percutaneous nephrolithotomy for complex renal calculi

    PubMed Central

    Buldu, İbrahim; Tepeler, Abdulkadir; Karatağ, Tuna; İnan, Ramazan; Armağan, Abdullah; İstanbulluoğlu, Okan

    2016-01-01

    Objective We aimed to present the technique of combination of standard percutaneous nephrolithotomy (PNL) with microperc for achieving higher success rates without increasing complication rates in the management of complex renal calculi. Material and methods The patients who underwent microperc procedure as a complementary procedure to standard PNL for complex kidney stones in two reference hospitals between 2013 and 2015, were evaluated retrospectively. Results All patients underwent a total of two accesses one for standard PNL and one for microperc. The mean stone size was measured as 54.3 mm. The procedures were completed after an average operative time of 88.2 minutes and fluoroscopy time of 5.3 minutes. Stone free status was achieved in 18 cases (78.2%) and small residual fragments (≤4 mm) were detected in 3 cases (13.1%). Complications were seen in three patients (13%) as hemorrhage in one and postoperative fever in two patients. Conclusion Despite the limitations of this study, the combination of standard PNL and microperc might reduce the complication rates and increase the success rates when treating complex kidney stones. Future prospective and comparative studies are needed.

  19. Toxic variability and radiation sensitization by dichlorodiammineplatinum(II) complexes in Salmonella typhimurium cells

    SciTech Connect

    Richmond, R.C.

    1984-09-01

    The oxidative coordination compound cis-dichlorodiammineplatinum(II) (cis-DDP) is again shown to be a hypoxic cell radiation sensitizer. The mechanism of cis-DDP-induced radiation sensitization is complex. Results here indicate that cis-DDP sensitization operates in part through reactive free radicals, in part through the interactions of radiation-induced reactive Pt(I) intermediates, and in part through the involvement of thermodynamic and kinetic aspects of Pt(II)-DNA binding during irradiation. For the first time, radiation sensitization by trans-DDP is compared with a sensitizing concentration of cis-DDP within the same study. Both analogs are sensitizers, but with significant differences. Further, irradiated hypoxic solutions of cis-DDP are found to be more toxic than unirradiated solutions.

  20. Organisational standards for the delivery of intensity-modulated radiation therapy in Ontario.

    PubMed

    Whitton, A; Warde, P; Sharpe, M; Oliver, T K; Bak, K; Leszczynski, K; Etheridge, S; Fleming, K; Gutierrez, E; Favell, L; Green, E

    2009-04-01

    By minimising the effect of irradiation on surrounding tissue, intensity-modulated radiation therapy (IMRT) can deliver higher, more effective doses to the targeted tumour site, minimising treatment-related morbidity and possibly improving cancer control and cure. A multidisciplinary IMRT Expert Panel was convened to develop the organisational standards for the delivery of IMRT. The systematic literature search used MEDLINE, EMBASE, the Cochrane Database, the National Guidelines Clearing House and the Health Technology Assessment Database. An environmental scan of unpublished literature used the Google search engine to review the websites of key organisations, cancer agencies/centres and vendor sites in Canada, the USA, Australia and Europe. In total, 22 relevant guidance documents were identified; 12 from the published literature and 10 from the environmental scan. Professional and organisational standards for the provision of IMRT were developed through the analysis of this evidence and the consensus opinion of the IMRT Expert Panel. The resulting standards address the following domains: planning of new IMRT programmes, practice setting requirements, tools, devices and equipment requirements; professional training requirements; role of personnel; and requirements for quality assurance and safety. Here the IMRT Expert Panel offers organisational and professional standards for the delivery of IMRT, with the intent of promoting innovation, improving access and enhancing patient care.

  1. Quantification of beam complexity in intensity-modulated radiation therapy treatment plans

    SciTech Connect

    Du, Weiliang Cho, Sang Hyun; Zhang, Xiaodong; Kudchadker, Rajat J.; Hoffman, Karen E.

    2014-02-15

    Purpose: Excessive complexity in intensity-modulated radiation therapy (IMRT) plans increases the dose uncertainty, prolongs the treatment time, and increases the susceptibility to changes in patient or target geometry. To date, the tools for quantitative assessment of IMRT beam complexity are still lacking. In this study, The authors have sought to develop metrics to characterize different aspects of beam complexity and investigate the beam complexity for IMRT plans of different disease sites. Methods: The authors evaluated the beam complexity scores for 65 step-and-shoot IMRT plans from three sites (prostate, head and neck, and spine) and 26 volumetric-modulated arc therapy (VMAT) plans for the prostate. On the basis of the beam apertures and monitor unit weights of all segments, the authors calculated the mean aperture area, extent of aperture shape irregularity, and degree of beam modulation for each beam. Then the beam complexity values were averaged to obtain the complexity metrics of the IMRT plans. The authors studied the correlation between the beam complexity metrics and the quality assurance (QA) results. Finally, the effects of treatment planning parameters on beam complexity were studied. Results: The beam complexity scores were not uniform among the prostate IMRT beams from different gantry angles. The lateral beams had larger monitor units and smaller shape irregularity, while the anterior-posterior beams had larger modulation values. On average, the prostate IMRT plans had the smallest aperture irregularity, beam modulation, and normalized monitor units; the head and neck IMRT plans had large beam irregularity and beam modulation; and the spine stereotactic radiation therapy plans often had small beam apertures, which may have been associated with the relatively large discrepancies between planned and QA measured doses. There were weak correlations between the beam complexity scores and the measured dose errors. The prostate VMAT beams showed

  2. The standard enthalpies of combustion and formation of crystalline cobalt tetrakis(4-metoxyphenyl)porphin complex

    NASA Astrophysics Data System (ADS)

    Tarasov, R. P.; Volkov, A. V.; Bazanov, M. I.; Semeikin, A. S.

    2009-05-01

    The energy of combustion of cobalt tetrakis(4-metoxyphenyl)porphin was determined in an isothermic-shell liquid calorimeter with a stationary calorimetric bomb. The standard enthalpies of combustion and formation of the complex were calculated, -Δ c H o = 27334.06 ± 50.98 kJ/mol and Δf H o = 3062.90 ± 50.97 kJ/mol.

  3. Heritability and complex segregation analysis of hypoadrenocorticism in the standard poodle.

    PubMed

    Famula, T R; Belanger, J M; Oberbauer, A M

    2003-01-01

    The heritability of hypoadrenocorticism (Addison's disease) was evaluated in 778 standard poodles with known Addisonian phenotypes. Addisonian status was confirmed clinically by adrenocorticotropic hormone (ACTH) challenge and 8.6 per cent of the poodles enrolled in the study were classified as being Addisonian. Hypoadrenocorticism affected both sexes with equal probability (P > 0.1). The most common coat colours had a negligible effect on the incidence of hypoadrenocorticism (P > 0.09), although red coat colour had a significant impact on the disease, probably due to the relatively small numbers of dogs with that coat colour. The heritability of hypoadrenocorticism in the standard poodle was estimated to be 0.75. Complex segregation analyses suggested that hypoadrenocorticism in the breed is influenced by an autosomal recessive locus. Clarification of both the heritability and mode of inheritance of hypoadrenocorticism in the standard poodle allows for better-informed breeding decisions.

  4. Influence of complex impurity centres on radiation damage in wide-gap metal oxides

    NASA Astrophysics Data System (ADS)

    Lushchik, A.; Lushchik, Ch.; Popov, A. I.; Schwartz, K.; Shablonin, E.; Vasil'chenko, E.

    2016-05-01

    Different mechanisms of radiation damage of wide-gap metal oxides as well as a dual influence of impurity ions on the efficiency of radiation damage have been considered on the example of binary ionic MgO and complex ionic-covalent Lu3Al5O12 single crystals. Particular emphasis has been placed on irradiation with ∼2 GeV heavy ions (197Au, 209Bi, 238U, fluence of 1012 ions/cm2) providing extremely high density of electronic excitations within ion tracks. Besides knock-out mechanism for Frenkel pair formation, the additional mechanism through the collapse of mobile discrete breathers at certain lattice places (e.g., complex impurity centres) leads to the creation of complex defects that involve a large number of host atoms. The experimental manifestations of the radiation creation of intrinsic and impurity antisite defects (Lu|Al or Ce|Al - a heavy ion in a wrong cation site) have been detected in LuAG and LuAG:Ce3+ single crystals. Light doping of LuAG causes a small enhancement of radiation resistance, while pair impurity centres (for instance, Ce|Lu-Ce|Al or Cr3+-Cr3+ in MgO) are formed with a rise of impurity concentration. These complex impurity centres as well as radiation-induced intrinsic antisite defects (Lu|Al strongly interacting with Lu in a regular site) tentatively serve as the places for breathers collapse, thus decreasing the material resistance against dense irradiation.

  5. Revised standards for protection against radiation; minor amendments--NRC. Final rule: minor corrective and conforming amendments.

    PubMed

    1992-12-01

    This final rule makes a number of minor corrective and conforming amendments to the NRC's revised standards for protection against radiation. The final rule is necessary to correct recently discovered errors in the text of the revised standards, to conform portions of regulatory text to the Commission's decision to defer mandatory implementation of the revised standards until 1994, and to reflect the recent OMB approval of the use of NRC Forms 4 and 5.

  6. Assessing Interpersonal and Communication Skills in Radiation Oncology Residents: A Pilot Standardized Patient Program

    SciTech Connect

    Ju, Melody; Berman, Abigail T.; Hwang, Wei-Ting; LaMarra, Denise; Baffic, Cordelia; Suneja, Gita; Vapiwala, Neha

    2014-04-01

    Purpose: There is a lack of data for the structured development and evaluation of communication skills in radiation oncology residency training programs. Effective communication skills are increasingly emphasized by the Accreditation Council for Graduate Medical Education and are critical for a successful clinical practice. We present the design of a novel, pilot standardized patient (SP) program and the evaluation of communication skills among radiation oncology residents. Methods and Materials: Two case scenarios were developed to challenge residents in the delivery of “bad news” to patients: one scenario regarding treatment failure and the other regarding change in treatment plan. Eleven radiation oncology residents paired with 6 faculty participated in this pilot program. Each encounter was scored by the SPs, observing faculty, and residents themselves based on the Kalamazoo guidelines. Results: Overall resident performance ratings were “good” to “excellent,” with faculty assigning statistically significant higher scores and residents assigning lower scores. We found inconsistent inter rater agreement among faculty, residents, and SPs. SP feedback was also valuable in identifying areas of improvement, including more collaborative decision making and less use of medical jargon. Conclusions: The program was well received by residents and faculty and regarded as a valuable educational experience that could be used as an annual feedback tool. Poor inter rater agreement suggests a need for residents and faculty physicians to better calibrate their evaluations to true patient perceptions. High scores from faculty members substantiate the concern that resident evaluations are generally positive and nondiscriminating. Faculty should be encouraged to provide honest and critical feedback to hone residents' interpersonal skills.

  7. Acoustic radiation force expressed using complex phase shifts and momentum-transfer cross sections.

    PubMed

    Zhang, Likun; Marston, Philip L

    2016-08-01

    Acoustic radiation force is expressed using complex phase shifts of partial wave scattering functions and the momentum-transfer cross section, herein incorporated into acoustics from quantum mechanisms. Imaginary parts of the phase shifts represent dissipation in the object and/or in the boundary layer adjacent to the object. The formula simplifies the force as summation of functions of complex phase shifts of adjacent partial waves involving differences of real parts and sums of imaginary parts, providing an efficient way of exploring the force parameter-space. The formula for the force is proportional to a generalized momentum-transfer cross section for plane waves and no dissipation. PMID:27586777

  8. Polarized radiative transfer in two-dimensional scattering medium with complex geometries by natural element method

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Kim, Yong-Jun; Yi, Hong-Liang; Xie, Ming; Tan, He-Ping

    2016-08-01

    The natural element method (NEM) is extended to solve the polarized radiative transfer problem in a two-dimensional scattering medium with complex geometries, in which the angular space is discretized by the discrete-ordinates approach, and the spatial discretization is conducted by the Galerkin weighted residuals approach. The Laplace interpolation scheme is adopted to obtain the shape functions used in the Galerkin weighted residuals approach. The NEM solution to the vector radiative transfer in a square enclosure filled with a Mie scattering medium is first examined to validate our program. We then study the polarized radiative transfer in two kinds of geometries filled with scattering medium which is equivalent to a suspension of latex spheres in water. Three sizes of spheres are considered. The results for non-dimensional polarized radiative flux along the boundaries and the angular distributions of the Stokes vector at specific positions are presented and discussed. For the complex geometry bounded by the square and circular object, numerical solutions are presented for the cases both with Lambertian (diffuse) reflection and with Fresnel reflection. Some interesting phenomenon are found and analyzed.

  9. Radiation thermometry standards at NMIJ from −30 °C to 2800 °C

    SciTech Connect

    Ishii, J.; Yamada, Y.; Sasajima, N.; Shimizu, Y.

    2013-09-11

    NMIJ has established a national standard scale in radiation thermometry from −30 °C to 2800 °C. At low temperatures from 160 °C down to −30 °C large aperture fluid-bath blackbodies have been constructed for the calibration of thermal infrared thermometers. In the range from 160 °C to 420 °C, the standard scale has been realized on 1.6 μm thermometers calibrated against In, Sn, and Zn blackbodies. A variable temperature blackbody using an air-bath furnace has recently been developed for direct comparison measurements of a 10 μm thermometer with a 1.6 μm thermometers up to 500 °C. In the higher range of the temperature scale, dissemination consists of three schemes: the range from 400 °C to 1100 °C by Zn, Al, Ag and Cu fixed-point blackbodies: above the Ag point by 0.9 μm and 0.65 μm thermometers: and above the Cu point by metal-carbon high-temperature fixed points.

  10. Investigation into the effects of VHF and UHF band radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    NASA Technical Reports Server (NTRS)

    Dickens, Andrew

    1995-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards. Tests carried out on the basis of these reports show that sources of VHF and UHF radiation such as two-way hand held police communications devices do cause reproducible adverse effects. This investigation examines reproducible effects and explores possible causes.

  11. Investigation into the effects of VHF and UHF band radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    NASA Astrophysics Data System (ADS)

    Dickens, Andrew

    1995-05-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards. Tests carried out on the basis of these reports show that sources of VHF and UHF radiation such as two-way hand held police communications devices do cause reproducible adverse effects. This investigation examines reproducible effects and explores possible causes.

  12. Assessing software upgrades, plan properties and patient geometry using intensity modulated radiation therapy (IMRT) complexity metrics

    SciTech Connect

    McGarry, Conor K.; Chinneck, Candice D.; O'Toole, Monica M.; O'Sullivan, Joe M; Prise, Kevin M.; Hounsell, Alan R.

    2011-04-15

    Purpose: The aim of this study is to compare the sensitivity of different metrics to detect differences in complexity of intensity modulated radiation therapy (IMRT) plans following upgrades, changes to planning parameters, and patient geometry. Correlations between complexity metrics are also assessed. Method: A program was developed to calculate a series of metrics used to describe the complexity of IMRT fields using monitor units (MUs) and multileaf collimator files: Modulation index (MI), modulation complexity score (MCS), and plan intensity map variation (PIMV). Each metric, including the MUs, was used to assess changes in beam complexity for six prostate patients, following upgrades in the inverse planning optimization software designed to incorporate direct aperture optimization (DAO). All beams were delivered to a 2D ionization chamber array and compared to those calculated using gamma analysis. Each complexity metric was then calculated for all beams, on a different set of six prostate IMRT patients, to assess differences between plans calculated using different minimum field sizes and different maximum segment numbers. Different geometries, including CShape, prostate, and head and neck phantoms, were also assessed using the metrics. Correlations between complexity metrics were calculated for 20 prostate IMRT patients. Results: MU, MCS, MI, and PIMV could all detect reduced complexity following an upgrade to the optimization leaf sequencer, although only MI and MCS could detect a reduction in complexity when one-step optimization (DAO) was employed rather than two-step optimization. All metrics detected a reduction in complexity when the minimum field size was increased from 1 to 4 cm and all apart from PIMV detected reduced complexity when the number of segments was significantly reduced. All metrics apart from MI showed differences in complexity depending on the treatment site. Significant correlations exist between all metrics apart from MI and PIMV for

  13. On the standard conjecture of Lefschetz type for complex projective threefolds

    NASA Astrophysics Data System (ADS)

    Tankeev, Sergei G.

    2010-02-01

    Under certain natural assumptions on cohomology of a complex projective fibred threefold with semi-stable degenerations, we prove the Grothendieck standard conjecture B(X) of Lefschetz type on the algebraicity of the operators \\Lambda and *. In particular, B(X) is true if at least one of the following conditions holds: 1) the generic fibre of some 1-parameter holomorphic family \\pi\\colon X\\to C is birationally equivalent to either a ruled surface, an Enriques surface, or a K3-surface, 2) all the fibres of \\pi are smooth surfaces of Kodaira dimension \\varkappa\\le0.

  14. Patterns of speciation in the Yucca moths: parallel species radiations within the Tegeticula yuccasella species complex.

    PubMed

    Althoff, David M; Segraves, Kari A; Leebens-Mack, James; Pellmyr, Olle

    2006-06-01

    The interaction between yuccas and yucca moths has been central to understanding the origin and loss of obligate mutualism and mutualism reversal. Previous systematic research using mtDNA sequence data and characters associated with genitalic morphology revealed that a widespread pollinator species in the genus Tegeticula was in fact a complex of pollinator species that differed in host use and the placement of eggs into yucca flowers. Within this mutualistic clade two nonpollinating "cheater" species evolved. Cheaters feed on yucca seeds but lack the tentacular mouthparts necessary for yucca pollination. Previous work suggested that the species complex formed via a rapid radiation within the last several million years. In this study, we use an expanded mtDNA sequence data set and AFLP markers to examine the phylogenetic relationships among this rapidly diverging clade of moths and compare these relationships to patterns in genitalic morphology. Topologies obtained from analyses of the mtDNA and AFLP data differed significantly. Both data sets, however, corroborated the hypothesis of a rapid species radiation and suggested that there were likely two independent species radiations. Morphological analyses based on oviposition habit produced species groupings more similar to the AFLP topology than the mtDNA topology and suggested the two radiations coincided with differences in oviposition habit. The evolution of cheating was reaffirmed to have evolved twice and the closest pollinating relative for one cheater species was identified by both mtDNA and AFLP markers. For the other cheater species, however, the closest pollinating relative remains ambiguous, and mtDNA, AFLP, and morphological data suggest this cheater species may be diverged based on host use. Much of the divergence in the species complex can be explained by geographic isolation associated with the evolution of two oviposition habits. PMID:16684719

  15. Addition of Bevacizumab to Standard Radiation Therapy and Daily Temozolomide Is Associated With Minimal Toxicity in Newly Diagnosed Glioblastoma Multiforme

    SciTech Connect

    Vredenburgh, James J.; Desjardins, Annick; Kirkpatrick, John P.; Reardon, David A.; Peters, Katherine B.; Herndon, James E.; Marcello, Jennifer; Bailey, Leighann; Threatt, Stevie; Sampson, John; Friedman, Allan; Friedman, Henry S.

    2012-01-01

    Purpose: To determine the safety of the addition of bevacizumab to standard radiation therapy and daily temozolomide for newly diagnosed glioblastoma multiforme (GBM). Methods and Materials: A total of 125 patients with newly diagnosed GBM were enrolled in the study, and received standard radiation therapy and daily temozolomide. All patients underwent a craniotomy and were at least 2 weeks postoperative. Radiation therapy was administered in 1.8-Gy fractions, with the clinical target volume for the primary course treated to a dose of 45 to 50.4 Gy, followed by a boost of 9 to 14.4 Gy, to a total dose of 59.4 Gy. Patients received temozolomide at 75 mg/m{sup 2} daily throughout the course of radiation therapy. Bevacizumab was given at 10 mg/kg intravenously every 14 days, beginning a minimum of 4 weeks postoperatively. Results: Of the 125 patients, 120 (96%) completed the protocol-specified radiation therapy. Five patients had to stop the protocol therapy, 2 patients with pulmonary emboli, and 1 patient each with a Grade 2 central nervous system hemorrhage, Grade 4 pancytopenia, and wound dehiscence requiring surgical intervention. All 5 patients ultimately finished the radiation therapy. After radiation therapy, 3 patients had progressive disease, 2 had severe fatigue and decreased performance status, 1 patient had a colonic perforation, and 1 had a rectal fissure; these 7 patients therefore did not proceed with the protocol-specified adjuvant temozolomide, bevacizumab, and irinotecan. However, 113 patients (90%) were able to continue on study. Conclusions: The addition of bevacizumab to standard radiation therapy and daily temozolomide was found to be associated with minimal toxicity in patients newly diagnosed with GBM.

  16. [Complex radiation diagnosis of retroperitoneal tumors and tumor-like states].

    PubMed

    Vlasov, P V; Kotliarov, P M

    1998-01-01

    The paper presents the results of complex radiation diagnosis of 118 cases of retroperitoneal tumors and tumor-like states, including 71 patients with tumors of mesenchymal origin, 7 with those of neurogenic origin, 6 with cysts, 9 with lymphogranulomatosis, 8 with retroperitoneal fibrosis, 12 with metastases, and 5 with hematomas. A wide complex of routine and up-to-date high-technology radiation diagnostic techniques was used to study the patients. The authors show the merits and dismerits of each technique. Greatest attention is given to the assessment of current techniques, primarily to ultrasonography (US) and computed tomography (CT). The studies have indicated that despite some specific features, many retroperitoneal tumors and tumor-like states bear similarities when various radiation methods are employed. The authors describe some syndromes which can be used to make a diagnosis. Despite the high capacities of US and CT in studying the normal and pathological structures of the human body, there are still great difficulties in differentiating different abnormalities when even the latest techniques are applied, these cases need paracentic aspiration or open biopsy.

  17. Radiation Protection. Measurement of radioactivity in the environment - Air- radon 222. A proposed ISO standard.

    NASA Astrophysics Data System (ADS)

    Gillmore, G.; Woods, M.

    2009-04-01

    Radon isotopes (222, 220, 219) are radioactive gases produced by the disintegration of radium isotopes 226, 224 and 223, which are decay products of uranium238, thorium232 and uranium235 respectively. All are found in the earth's crust. Solid elements, also radioactive, are produced by radon disintegration. Radon is classed as a rare gas in the periodic table of elements, along with helium, argon, neon, krypton and xenon. When disintegrating, radon emits alpha particles and generates solid decay products, which are also radioactive (polonium, bismuth, lead etc.). The potential danger of radon lies in its solid decay products rather than the gas itself. Whether or not they are attached aerosols, radon decay products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size. Radon today is considered to be the main source of human exposure to natural radiation. At the international level, radon accounts for 52% of global average exposure to natural radiation. Isotope 222 (48%) is far more significant than isotope 220 (4%), whilst isotope 219 is considered as negligible. Exposure to radon varies considerably from one region to another, depending on factors such as weather conditions, and underlying geology. Activity concentration can therefore vary by a factor of 10 or even a 100 from one period of time to the next and from one area to another. There are many ways of measuring the radon 222 activity concentration and the potential alpha energy concentration of its short-lived decay products. Measuring techniques fall into three categories: - spot measurement methods; continuous measurement; integrated measurement. The proposed ISO (International Organisation for Standardisation) document suggests guidelines for measuring radon222 activity concentration and the potential alpha energy concentration of its short-lived decay products in a free (environment) and confined (buildings) atmosphere. The target date for availability of

  18. Toward Standardized Acoustic Radiation Force (ARF)-Based Ultrasound Elasticity Measurements With Robotic Force Control

    PubMed Central

    Kumar, Shalki; Lily, Kuo; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter

    2016-01-01

    Objective Acoustic radiation force (ARF)-based approaches to measure tissue elasticity require transmission of a focused high-energy acoustic pulse from a stationary ultrasound probe and ultrasound-based tracking of the resulting tissue displacements to obtain stiffness images or shear wave speed estimates. The method has established benefits in biomedical applications such as tumor detection and tissue fibrosis staging. One limitation, however, is the dependence on applied probe pressure, which is difficult to control manually and prohibits standardization of quantitative measurements. To overcome this limitation, we built a robot prototype that controls probe contact forces for shear wave speed quantification. Methods The robot was evaluated with controlled force increments applied to a tissue-mimicking phantom and in vivo abdominal tissue from three human volunteers. Results The root-mean-square error between the desired and measured forces was 0.07 N in the phantom and higher for the fatty layer of in vivo abdominal tissue. The mean shear wave speeds increased from 3.7 to 4.5 m/s in the phantom and 1.0 to 3.0 m/s in the in vivo fat for compressive forces ranging from 2.5 to 30 N. The standard deviation of shear wave speeds obtained with the robotic approach were low in most cases (< 0.2 m/s) and comparable to that obtained with a semiquantitative landmark-based method. Conclusion Results are promising for the introduction of robotic systems to control the applied probe pressure for ARF-based measurements of tissue elasticity. Significance This approach has potential benefits in longitudinal studies of disease progression, comparative studies between patients, and large-scale multidimensional elasticity imaging. PMID:26552071

  19. Complex ray analysis of radiation from large apertures with tapered illumination

    NASA Astrophysics Data System (ADS)

    Ghione, G.; Felsen, L. B.; Montrosset, I.

    1984-07-01

    An attempt is made to model the initial distribution of radiation emitted by an antenna feed in terms of a building-block approach. Attention is given to both near and far field calculations for large apertures with tapered illumination. Generalized one-dimensional tapered profiles expressed in terms of the wavenumber and the aperture coordinate are used to handle profiles ranging from gaussian to rectangular. The analysis covers complex ray tracing from the aperture plane to the observer. The inclusion of all relevant rays is assured by a saddle point analysis of the exact field integral. The ray tracing procedure is demonstrated to be effective without reference to an aperture integral. Several field radiation patterns are calculated as examples.

  20. Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

    SciTech Connect

    Martin, P.R.

    1993-12-31

    This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards.

  1. Alanine-EPR as a transfer standard dosimetry system for low energy X radiation

    NASA Astrophysics Data System (ADS)

    Khoury, H. J.; da Silva, E. J.; Mehta, K.; de Barros, V. S.; Asfora, V. K.; Guzzo, P. L.; Parker, A. G.

    2015-11-01

    The purpose of this paper is to evaluate the use of alanine-EPR as a transfer standard dosimetry system for low energy X radiation, such as that in RS-2400, which operates in the range from 25 to 150 kV and 2 to 45 mA. Two types of alanine dosimeters were investigated. One is a commercial alanine pellets from Aérial-Centre de Ressources Technologiques, France and one was prepared in our laboratory (LMRI-DEN/UFPE). The EPR spectra of the irradiated dosimeters were recorded in the Nuclear Energy Department of UFPE, using a Bruker EMX10 EPR spectrometer operating in the X-band. The alanine-EPR dosimetry system was calibrated in the range of 20-220 Gy in this X-ray field, against an ionization chamber calibrated at the relevant X-ray energy with traceability to PTB. The results showed that both alanine dosimeters presented a linear dose response the same sensitivity, when the EPR signal was normalized to alanine mass. The total uncertainty in the measured dose was estimated to be about 3%. The results indicate that it is possible to use the alanine-EPR dosimetry system for validation of a low-energy X ray irradiator, such as RS-2400.

  2. Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme.

    PubMed

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Kulkarni, M S; Tomar, B S

    2016-02-01

    A standardization of (134)Cs and (131)I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision.

  3. Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme.

    PubMed

    Kulkarni, D B; Anuradha, R; Joseph, Leena; Kulkarni, M S; Tomar, B S

    2016-02-01

    A standardization of (134)Cs and (131)I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision. PMID:26678524

  4. Radiation injury is a potentially serious complication to fluoroscopically-guided complex interventions

    PubMed Central

    Wagner, LK

    2007-01-01

    Radiation-induced injury to skin is an infrequent but potentially serious complication to complex fluoroscopically-guided interventional procedures. Due to a lack of experience with such injuries, the medical community has found fluoroscopically-induced injuries difficult to diagnose. Injuries have occurred globally in many countries. Serious injuries most frequently occur on the back but have also occurred on the neck, buttocks and anterior of the chest. Severities of injuries range from skin rashes and epilation to necrosis of the skin and its underlying structures. This article reviews the characteristics of these injuries and some actions that can be taken to reduce their likelihood or seriousness. PMID:21614271

  5. Second cancer incidence risk estimates using BEIR VII models for standard and complex external beam radiotherapy for early breast cancer

    SciTech Connect

    Donovan, E. M.; James, H.; Bonora, M.; Yarnold, J. R.; Evans, P. M.

    2012-10-15

    Purpose: To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer.Method: Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermoluminescent dosimeter measurements in an anthropomorphic phantom in which the positions of radiosensitive organs were delineated. Five treatment deliveries were investigated: (i) conventional tangential field whole breast radiotherapy (WBRT), (ii) noncoplanar conformal delivery applicable to accelerated partial beast irradiation (APBI), (iii) two-volume simultaneous integrated boost (SIB) treatment, (iv) forward planned three-volume SIB, and (v) inverse-planned three volume SIB. Conformal and intensity modulated radiotherapy methods were used to plan the complex treatments. Techniques spanned the range from simple methods appropriate for patient cohorts with a low cancer recurrence risk to complex plans relevant to cohorts with high recurrence risk. Delineated organs at risk included brain, salivary glands, thyroid, contralateral breast, left and right lung, esophagus, stomach, liver, colon, and bladder. Biological Effects of Ionizing Radiation (BEIR) VII cancer incidence models were applied to the measured mean organ doses to determine lifetime attributable risk (LAR) for ages at exposure from 35 to 80 yr according to radiotherapy techniques, and included dose from the CBCT imaging. Results: All LAR decreased with age at exposure and were lowest for brain, thyroid, liver, and bladder (<0.1%). There was little dependence of LAR on radiotherapy technique for these organs and for colon and stomach. LAR values for the lungs for the three SIB techniques were two to three times those from WBRT and APBI. Uncertainties in the LAR models outweigh any differences in lung LAR between the SIB methods. Constraints in the planning of the SIB methods ensured that

  6. Validation testing of ANSI/IEEE n42.49 standard requirements for personal emergency radiation detectors.

    PubMed

    Pibida, L; Minniti, R; O'Brien, M

    2010-04-01

    Various radiation detectors including electronic personal emergency radiation detectors (PERDs), radiochromic film cards and thermoluminescent dosimeters (TLDs) were used to validate a subset of the radiological test requirements listed in the American National Standards Institute/The Institute of Electrical and Electronic Engineers (ANSI/IEEE) N42.49 standard. The subset of tests included the following: comparing the readout of the detectors with the value given at the National Institute of Standards and Technology (NIST); testing of the alarm settings (when applicable) in air-kerma (or exposure) and air-kerma rate (or exposure rate) mode; and investigating the effect of testing the detectors mounted on a phantom and free in air. The purpose of this work was not to test the performance of the sample of detectors used. Instead, the detectors were used to validate the requirements of the written standard being developed. For this purpose, the performance and response of these instruments were recorded when placed in (137)Cs, and x-ray beams at different air-kerma rates and test conditions. The measurements described in this report were performed at the NIST x-ray and gamma-ray radiation calibration facilities. The data in this report provide a benchmark in support of the development of the ANSI/IEEE N42.49 standard.

  7. Opportunities for radiation-dose optimization through standardized analytics and decision support.

    PubMed

    Reiner, Bruce I

    2014-11-01

    Although the potential for adverse clinical outcomes related to medical radiation have been well documented for over a century, several relatively recent trends have increased awareness of radiation safety in medical imaging. These include expanded CT applications and utilization, increased patient attention on radiation carcinogenesis, and a wide array of legislative and societal radiation initiatives, created partly in response to media reports of CT-induced radiation complications. With this heightened radiation awareness and scrutiny comes a unique and timely opportunity for the collective medical-imaging community to incorporate comparative radiation metrics and analysis directly into routine workflow and reporting. If properly performed, a number of benefits could in theory be derived, including improved clinical outcomes, creation of data-driven best practice guidelines, opportunities for enhanced education and research, dose-reduction technology innovation, and reversal of existing commoditization trends. PMID:25163408

  8. Opportunities for radiation-dose optimization through standardized analytics and decision support.

    PubMed

    Reiner, Bruce I

    2014-11-01

    Although the potential for adverse clinical outcomes related to medical radiation have been well documented for over a century, several relatively recent trends have increased awareness of radiation safety in medical imaging. These include expanded CT applications and utilization, increased patient attention on radiation carcinogenesis, and a wide array of legislative and societal radiation initiatives, created partly in response to media reports of CT-induced radiation complications. With this heightened radiation awareness and scrutiny comes a unique and timely opportunity for the collective medical-imaging community to incorporate comparative radiation metrics and analysis directly into routine workflow and reporting. If properly performed, a number of benefits could in theory be derived, including improved clinical outcomes, creation of data-driven best practice guidelines, opportunities for enhanced education and research, dose-reduction technology innovation, and reversal of existing commoditization trends.

  9. Standardized Whole-Blood Transcriptional Profiling Enables the Deconvolution of Complex Induced Immune Responses.

    PubMed

    Urrutia, Alejandra; Duffy, Darragh; Rouilly, Vincent; Posseme, Céline; Djebali, Raouf; Illanes, Gabriel; Libri, Valentina; Albaud, Benoit; Gentien, David; Piasecka, Barbara; Hasan, Milena; Fontes, Magnus; Quintana-Murci, Lluis; Albert, Matthew L

    2016-09-01

    Systems approaches for the study of immune signaling pathways have been traditionally based on purified cells or cultured lines. However, in vivo responses involve the coordinated action of multiple cell types, which interact to establish an inflammatory microenvironment. We employed standardized whole-blood stimulation systems to test the hypothesis that responses to Toll-like receptor ligands or whole microbes can be defined by the transcriptional signatures of key cytokines. We found 44 genes, identified using Support Vector Machine learning, that captured the diversity of complex innate immune responses with improved segregation between distinct stimuli. Furthermore, we used donor variability to identify shared inter-cellular pathways and trace cytokine loops involved in gene expression. This provides strategies for dimension reduction of large datasets and deconvolution of innate immune responses applicable for characterizing immunomodulatory molecules. Moreover, we provide an interactive R-Shiny application with healthy donor reference values for induced inflammatory genes. PMID:27568558

  10. Experimental and theoretical study of organometallic radiation-protective materials adapted to radiation sources with a complex isotopic composition

    SciTech Connect

    Russkikh, I. M.; Seleznev, E. N.; Tashlykov, O. L. Shcheklein, S. E.

    2015-12-15

    The significance of optimizing the content of components of a radiation-protective material, which is determined by the isotopic composition of radioactive contamination, depending on the reactor type, operating time, and other factors is demonstrated. The results of computational and experimental investigation of the gamma-radiation attenuation capacity of homogenous radiation-protective materials with different fillers are reported.

  11. Upping the Ante of Text Complexity in the Common Core State Standards: Examining Its Potential Impact on Young Readers

    ERIC Educational Resources Information Center

    Hiebert, Elfrieda H.; Mesmer, Heidi Anne E.

    2013-01-01

    The Common Core Standards for the English Language Arts (CCSS) provide explicit guidelines matching grade-level bands (e.g., 2-3, 4-5) with targeted text complexity levels. The CCSS staircase accelerates text expectations for students across Grades 2-12 in order to close a gap in the complexity of texts typically used in high school and those of…

  12. 42 CFR Appendix E to Part 75 - Standards for Accreditation of Educational Programs for Radiation Therapy Technologists

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...; (j) Radiation physics; (k) Radiation protection; (l) Radiation oncology technique; (m) Radiographic... knowledge of radiation physics in radiation interactions and radiation protection techniques; (f) Provide...) Successful completion or challenge of courses in the following prerequisite content areas: —Radiation...

  13. 42 CFR Appendix E to Part 75 - Standards for Accreditation of Educational Programs for Radiation Therapy Technologists

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; (j) Radiation physics; (k) Radiation protection; (l) Radiation oncology technique; (m) Radiographic... knowledge of radiation physics in radiation interactions and radiation protection techniques; (f) Provide...) Successful completion or challenge of courses in the following prerequisite content areas: —Radiation...

  14. 42 CFR Appendix E to Part 75 - Standards for Accreditation of Educational Programs for Radiation Therapy Technologists

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; (j) Radiation physics; (k) Radiation protection; (l) Radiation oncology technique; (m) Radiographic... knowledge of radiation physics in radiation interactions and radiation protection techniques; (f) Provide...) Successful completion or challenge of courses in the following prerequisite content areas: —Radiation...

  15. 42 CFR Appendix E to Part 75 - Standards for Accreditation of Educational Programs for Radiation Therapy Technologists

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; (j) Radiation physics; (k) Radiation protection; (l) Radiation oncology technique; (m) Radiographic... knowledge of radiation physics in radiation interactions and radiation protection techniques; (f) Provide...) Successful completion or challenge of courses in the following prerequisite content areas: —Radiation...

  16. Spectrophotometric study of complexation equilibria with H-point standard addition and H-point curve isolation methods.

    PubMed

    Abdollahi, H; Zeinali, S

    2004-01-01

    The use of H-point curve isolation (HPCIM) and H-point standard addition methods (HPSAM) for spectrophotometric studies of complex formation equilibria are proposed. One step complex formation, two successive stepwise and mononuclear complex formation systems, and competitive complexation systems are studied successfully by the proposed methods. HPCIM is used for extracting the spectrum of complex or sum of complex species and HPSAM is used for calculation of equilibrium concentrations of ligand for each sample. The outputs of these procedures are complete concentration profiles of equilibrium system, spectral profile of intermediate components, and good estimation of conditional formation constants. The reliability of the method is evaluated using model data. Spectrophotometric studies of murexide-calcium, dithizone-nickel, methyl thymol blue (MTB)-copper, and competition of murexide and sulfate ions for complexation with zinc, are used as experimental model systems with different complexation stoichiometries and spectral overlapping of involved components.

  17. Both Complexity and Location of DNA Damage Contribute to Cellular Senescence Induced by Ionizing Radiation

    PubMed Central

    Zhang, Xurui; Ye, Caiyong; Sun, Fang; Wei, Wenjun; Hu, Burong; Wang, Jufang

    2016-01-01

    Persistent DNA damage is considered as a main cause of cellular senescence induced by ionizing radiation. However, the molecular bases of the DNA damage and their contribution to cellular senescence are not completely clear. In this study, we found that both heavy ions and X-rays induced senescence in human uveal melanoma 92–1 cells. By measuring senescence associated-β-galactosidase and cell proliferation, we identified that heavy ions were more effective at inducing senescence than X-rays. We observed less efficient repair when DNA damage was induced by heavy ions compared with X-rays and most of the irreparable damage was complex of single strand breaks and double strand breaks, while DNA damage induced by X-rays was mostly repaired in 24 hours and the remained damage was preferentially associated with telomeric DNA. Our results suggest that DNA damage induced by heavy ion is often complex and difficult to repair, thus presents as persistent DNA damage and pushes the cell into senescence. In contrast, persistent DNA damage induced by X-rays is preferentially associated with telomeric DNA and the telomere-favored persistent DNA damage contributes to X-rays induced cellular senescence. These findings provide new insight into the understanding of high relative biological effectiveness of heavy ions relevant to cancer therapy and space radiation research. PMID:27187621

  18. Evaluation of digital breast tomosynthesis reconstruction algorithms using synchrotron radiation in standard geometry

    SciTech Connect

    Bliznakova, K.; Kolitsi, Z.; Speller, R. D.; Horrocks, J. A.; Tromba, G.; Pallikarakis, N.

    2010-04-15

    Purpose: In this article, the image quality of reconstructed volumes by four algorithms for digital tomosynthesis, applied in the case of breast, is investigated using synchrotron radiation. Methods: An angular data set of 21 images of a complex phantom with heterogeneous tissue-mimicking background was obtained using the SYRMEP beamline at ELETTRA Synchrotron Light Laboratory, Trieste, Italy. The irradiated part was reconstructed using the multiple projection algorithm (MPA) and the filtered backprojection with ramp followed by hamming windows (FBR-RH) and filtered backprojection with ramp (FBP-R). Additionally, an algorithm for reducing the noise in reconstructed planes based on noise mask subtraction from the planes of the originally reconstructed volume using MPA (MPA-NM) has been further developed. The reconstruction techniques were evaluated in terms of calculations and comparison of the contrast-to-noise ratio (CNR) and artifact spread function. Results: It was found that the MPA-NM resulted in higher CNR, comparable with the CNR of FBP-RH for high contrast details. Low contrast objects are well visualized and characterized by high CNR using the simple MPA and the MPA-NM. In addition, the image quality of the reconstructed features in terms of CNR and visual appearance as a function of the initial number of projection images and the reconstruction arc was carried out. Slices reconstructed with more input projection images result in less reconstruction artifacts and higher detail CNR, while those reconstructed from projection images acquired in reduced angular range causes pronounced streak artifacts. Conclusions: Of the reconstruction algorithms implemented, the MPA-NM and MPA are a good choice for detecting low contrast objects, while the FBP-RH, FBP-R, and MPA-NM provide high CNR and well outlined edges in case of microcalcifications.

  19. MDP: A Deinococcus Mn2+-Decapeptide Complex Protects Mice from Ionizing Radiation

    PubMed Central

    Smith, Joan T.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Grichenko, Olga; Knollmann-Ritschel, Barbara; Daly, Michael J.; Kiang, Juliann G.

    2016-01-01

    The radioprotective capacity of a rationally-designed Mn2+-decapeptide complex (MDP), based on Mn antioxidants in the bacterium Deinococcus radiodurans, was investigated in a mouse model of radiation injury. MDP was previously reported to be extraordinarily radioprotective of proteins in the setting of vaccine development. The peptide-component (DEHGTAVMLK) of MDP applied here was selected from a group of synthetic peptides screened in vitro for their ability to protect cultured human cells and purified enzymes from extreme damage caused by ionizing radiation (IR). We show that the peptides accumulated in Jurkat T-cells and protected them from 100 Gy. MDP preserved the activity of T4 DNA ligase exposed to 60,000 Gy. In vivo, MDP was nontoxic and protected B6D2F1/J (female) mice from acute radiation syndrome. All irradiated mice treated with MDP survived exposure to 9.5 Gy (LD70/30) in comparison to the untreated mice, which displayed 63% lethality after 30 days. Our results show that MDP provides early protection of white blood cells, and attenuates IR-induced damage to bone marrow and hematopoietic stem cells via G-CSF and GM-CSF modulation. Moreover, MDP mediated the immunomodulation of several cytokine concentrations in serum including G-CSF, GM-CSF, IL-3 and IL-10 during early recovery. Our results present the necessary prelude for future efforts towards clinical application of MDP as a promising IR countermeasure. Further investigation of MDP as a pre-exposure prophylactic and post-exposure therapeutic in radiotherapy and radiation emergencies is warranted. PMID:27500529

  20. ["Epistemic Negotiations" and the Pluralism of the Radiation Protection Regime: The Determination of Radiation Protection Standards for the General Population in the Early Years After World War II].

    PubMed

    Higuchi, Toshihiro

    2015-10-01

    Radiation protection standards for the general population have constituted one of the most controversial subjects in the history of atomic energy uses. This paper reexamines the process in which the first such standards evolved in the early postwar period. While the existing literature has emphasized a "collusion" between the standard-setters and users, the paper seeks to examine the horizontal relationship among the standard-setters. It first examines a series of expert consultations between the United States and the United Kingdom. Representing a different configuration of power and interest, the two failed to agree on the assessment of genetic damage and cancer induction whose occurrence might have no threshold and therefore be dependent on the population size. This stalemate prevented the International Commission on Radiological Protection (ICRP), established in 1950, from formulating separate guidelines for the general public. Situations radically changed when the Bikini incident in 1954 led to the creation of more scientific panels. One such panel under the U.S. Academy of Sciences enabled the geneticists to bridge their internal divide, unanimously naming 100 mSv as the genetically permissible dose for the general population. Not to be outdone, ICRP publicized its own guidelines for the same purpose. The case examined in this paper shows that the standard-setting process is best understood as a series of "epistemic negotiations" among and within the standard-setters, whose agendas were determined from the outset but whose outcomes were not.

  1. Locoregional Outcomes of Inflammatory Breast Cancer Patients Treated With Standard Fractionation Radiation and Daily Skin Bolus in the Taxane Era

    SciTech Connect

    Damast, Shari; Ho, Alice Y.; Montgomery, Leslie; Fornier, Monica N.; Ishill, Nicole; Elkin, Elena; Beal, Kathryn; McCormick, Beryl

    2010-07-15

    Purpose: To assess locoregional outcomes of inflammatory breast cancer (IBC) patients who received standard fractionation radiation with daily skin bolus and taxanes as part of combined-modality therapy (CMT). Methods and Materials: We retrospectively reviewed the charts of 107 patients diagnosed with IBC between January 1995 and March 2006 who presented to our department for adjuvant radiation therapy (RT). Results: All patients received chemotherapy (95% anthracycline and 95% taxane), modified radical mastectomy, and RT to the chest wall and regional lymphatics using standard fractionation to 50 Gy and daily skin bolus. The RT to the chest wall was delivered via electrons (55%) or photons (45%) in daily fractions of 180 cGy (73%) or 200 cGy (27%). Scar boost was performed in 11%. A majority (84%) of patients completed the prescribed treatment. Median follow-up was 47 months (range, 10-134 months). Locoregional control (LRC) at 3 years and 5 years was 90% and 87%, respectively. Distant metastases-free survival (DMFS) at 3 years and 5 years was 61% and 47%, respectively. Conclusions: Excellent locoregional control was observed in this population of IBC patients who received standard fractionation radiation with daily skin bolus and taxanes as part of combined-modality therapy. Distant metastases-free survival remains a significant therapeutic challenge.

  2. Generics Substitution, Bioequivalence Standards, and International Oversight: Complex Issues Facing the FDA.

    PubMed

    Bate, Roger; Mathur, Aparna; Lever, Harry M; Thakur, Dinesh; Graedon, Joe; Cooperman, Tod; Mason, Preston; Fox, Erin R

    2016-03-01

    The regulations for assessing the quality of generic drugs and their bioequivalence to innovator products are outdated and need to be substantially modernized. There are multiple reasons why these changes are needed, including: (i) the regulations remain largely unchanged since the passage of the Hatch-Waxman Act in 1984; (ii) medication therapies have become substantially more complex over the three decades since the passage of the Act; (iii) a switch from an innovator drug to a generic drug, or switching from one generic to another, is not a benign process - there is substantial clinical professional judgment involved and in some instances these decisions should be better informed; and (iv) pharmaceutical ingredients for finished products, whether innovator or generic, are from multiple sources of supply, adding variability in their production, and which may not be accounted for in specification tolerances. When these elements are viewed together, they clearly suggest that more transparency of responsible manufacturers in product labels and updated standards for bioequivalence are required. PMID:26687297

  3. The concept of a unified modeling of optical radiation propagation in complex turbid media

    NASA Astrophysics Data System (ADS)

    Meglinski, I.; Kirillin, M.; Kuzmin, V. L.

    2008-09-01

    Multipurpose unified Monte Carlo (MC) based model is developed for adequate simulation of various aspects of optical/ laser radiation propagation within biological tissues. The modeling is aimed to provide predictive information to optimize clinical/biomedical optical diagnostic systems and improve interpretation of the experimental results in biomedical diagnostics. Complex structure of biological tissues in terms of scattering and absorption is presented on the example of human skin. Validation and verification are performed against the tabulated data, theoretical predictions, and experiments. We demonstrate the use of the model to imitate 2-D polarization-sensitive OCT images with non-planar boundaries of layers in the medium like a human skin. The performances of the model are demonstrated both for conventional and polarization-sensitive OCT modalities.

  4. Numerical simulation of acoustofluidic manipulation by radiation forces and acoustic streaming for complex particles.

    PubMed

    Hahn, Philipp; Leibacher, Ivo; Baasch, Thierry; Dual, Jurg

    2015-11-21

    The numerical prediction of acoustofluidic particle motion is of great help for the design, the analysis, and the physical understanding of acoustofluidic devices as it allows for a simple and direct comparison with experimental observations. However, such a numerical setup requires detailed modeling of the acoustofluidic device with all its components and thorough understanding of the acoustofluidic forces inducing the particle motion. In this work, we present a 3D trajectory simulation setup that covers the full spectrum, comprising a time-harmonic device model, an acoustic streaming model of the fluid cavity, a radiation force simulation, and the calculation of the hydrodynamic drag. In order to make quantitatively accurate predictions of the device vibration and the acoustic field, we include the viscous boundary layer damping. Using a semi-analytical method based on Nyborg's calculations, the boundary-driven acoustic streaming is derived directly from the device simulation and takes into account cavity wall vibrations which have often been neglected in the literature. The acoustic radiation forces and the hydrodynamic drag are calculated numerically to handle particles of arbitrary shape, structure, and size. In this way, complex 3D particle translation and rotation inside experimental microdevices can be predicted. We simulate the rotation of a microfiber in an amplitude-modulated 2D field and analyze the results with respect to experimental observations. For a quantitative verification, the motion of an alumina microdisk is compared to a simple experiment. Demonstrating the potential of the simulation setup, we compute the trajectory of a red blood cell inside a realistic microdevice under the simultaneous effects of acoustic streaming and radiation forces. PMID:26448531

  5. Numerical simulation of acoustofluidic manipulation by radiation forces and acoustic streaming for complex particles.

    PubMed

    Hahn, Philipp; Leibacher, Ivo; Baasch, Thierry; Dual, Jurg

    2015-11-21

    The numerical prediction of acoustofluidic particle motion is of great help for the design, the analysis, and the physical understanding of acoustofluidic devices as it allows for a simple and direct comparison with experimental observations. However, such a numerical setup requires detailed modeling of the acoustofluidic device with all its components and thorough understanding of the acoustofluidic forces inducing the particle motion. In this work, we present a 3D trajectory simulation setup that covers the full spectrum, comprising a time-harmonic device model, an acoustic streaming model of the fluid cavity, a radiation force simulation, and the calculation of the hydrodynamic drag. In order to make quantitatively accurate predictions of the device vibration and the acoustic field, we include the viscous boundary layer damping. Using a semi-analytical method based on Nyborg's calculations, the boundary-driven acoustic streaming is derived directly from the device simulation and takes into account cavity wall vibrations which have often been neglected in the literature. The acoustic radiation forces and the hydrodynamic drag are calculated numerically to handle particles of arbitrary shape, structure, and size. In this way, complex 3D particle translation and rotation inside experimental microdevices can be predicted. We simulate the rotation of a microfiber in an amplitude-modulated 2D field and analyze the results with respect to experimental observations. For a quantitative verification, the motion of an alumina microdisk is compared to a simple experiment. Demonstrating the potential of the simulation setup, we compute the trajectory of a red blood cell inside a realistic microdevice under the simultaneous effects of acoustic streaming and radiation forces.

  6. Combined radiation pressure and thermal modelling of complex satellites: Algorithms and on-orbit tests

    NASA Astrophysics Data System (ADS)

    Ziebart, M.; Adhya, S.; Sibthorpe, A.; Edwards, S.; Cross, P.

    In an era of high resolution gravity field modelling the dominant error sources in spacecraft orbit determination are non-conservative spacecraft surface forces. These forces can be difficult to characterise a priori because they require detailed modelling of: spacecraft geometry and surface properties; attitude behaviour; the spatial and temporal variations of the incident radiation and particle fluxes and the interaction of these fluxes with the surfaces. The conventional approach to these problems is to build simplified box-and-wing models of the satellites and to estimate empirically factors that account for the inevitable mis-modelling. Over the last few years the authors have developed a suite of software utilities that model analytically three of the main effects: solar radiation pressure, thermal forces and the albedo/earthshine effects. The techniques are designed specifically to deal with complex spacecraft structures, no structural simplifications are made and the method can be applied to any spacecraft. Substantial quality control measures are used during computation to both avoid and trap errors. The paper presents the broad basis of the modelling techniques for each of the effects, and gives the results of recent tests applied to GPS Block IIR satellites and the low Earth orbit satellite altimeter JASON-1.

  7. Bond Fission and Non-Radiative Decay in Iridium(III) Complexes.

    PubMed

    Zhou, Xiuwen; Burn, Paul L; Powell, Benjamin J

    2016-06-01

    We investigate the role of metal-ligand bond fission in the nonradiative decay of excited states in iridium(III) complexes with applications in blue organic light-emitting diodes (OLEDs). We report density functional theory (DFT) calculations of the potential energy surfaces upon lengthening an iridium-nitrogen (Ir-N) bond. In all cases we find that for bond lengths comparable to those of the ground state the lowest energy state is a triplet with significant metal-to-ligand change transfer character ((3)MLCT). But, as the Ir-N bond is lengthened there is a sudden transition to a regime where the lowest excited state is a triplet with significant metal centered character ((3)MC). Time-dependent DFT relativistic calculations including spin-orbit coupling perturbatively show that the radiative decay rate from the (3)MC state is orders of magnitude slower than that from the (3)MLCT state. The calculated barrier height between the (3)MLCT and (3)MC regimes is clearly correlated with previously measured nonradiative decay rates, suggesting that thermal population of the (3)MC state is the dominant nonradiative decay process at ambient temperature. In particular, fluorination both drives the emission of these complexes to a deeper blue color and lowers the (3)MLCT-(3)MC barrier. If the Ir-N bond is shortened in the (3)MC state another N atom is pushed away from the Ir, resulting in the breaking of this bond, suggesting that once the Ir-N bond breaks the damage to the complex is permanent-this will have important implications for the lifetimes of devices using this type of complex as the active material. The consequences of these results for the design of more efficient blue phosphors for OLED applications are discussed. PMID:27175618

  8. Low-dose ionizing radiation induces mitochondrial fusion and increases expression of mitochondrial complexes I and III in hippocampal neurons

    PubMed Central

    Chang, Chuang-Rung; Kao, Mou-Chieh; Chen, Kuan-Wei; Chiu, Shih-Che; Hsu, Ming-Ling; Hsiang, I-Chou; Chen, Yu-Jen; Chen, Linyi

    2015-01-01

    High energy ionizing radiation can cause DNA damage and cell death. During clinical radiation therapy, the radiation dose could range from 15 to 60 Gy depending on targets. While 2 Gy radiation has been shown to cause cancer cell death, studies also suggest a protective potential by low dose radiation. In this study, we examined the effect of 0.2-2 Gy radiation on hippocampal neurons. Low dose 0.2 Gy radiation treatment increased the levels of MTT. Since hippocampal neurons are post-mitotic, this result reveals a possibility that 0.2 Gy irradiation may increase mitochondrial activity to cope with stimuli. Maintaining neural plasticity is an energy-demanding process that requires high efficient mitochondrial function. We thus hypothesized that low dose radiation may regulate mitochondrial dynamics and function to ensure survival of neurons. Our results showed that five days after 0.2 Gy irradiation, no obvious changes on neuronal survival, neuronal synapses, membrane potential of mitochondria, reactive oxygen species levels, and mitochondrial DNA copy numbers. Interestingly, 0.2 Gy irradiation promoted the mitochondria fusion, resulting in part from the increased level of a mitochondrial fusion protein, Mfn2, and inhibition of Drp1 fission protein trafficking to the mitochondria. Accompanying with the increased mitochondrial fusion, the expressions of complexes I and III of the electron transport chain were also increased. These findings suggest that, hippocampal neurons undergo increased mitochondrial fusion to modulate cellular activity as an adaptive mechanism in response to low dose radiation. PMID:26415228

  9. Collaborative study for the establishment of the 2(nd) International Standard for Bleomycin Complex A2/B2.

    PubMed

    Jorajuria, S; Raphalen, C; Dujardin, V; Daas, A

    2015-01-01

    Organization (WHO) International Standard (IS) for bleomycin complex A2/B2. Eight laboratories from different countries participated. Potencies of the candidate material were estimated by microbiological assays with sensitive micro-organisms. To ensure continuity between consecutive batches, the 1(st) IS for bleomycin complex A2/B2 was used as a reference. Based on the results of the study, the 2(nd) IS for bleomycin complex A2/B2 was adopted at the meeting of the WHO Expert Committee for Biological Standardization (ECBS) in 2014 with an assigned potency of 12 500 International Units (IU) per vial. The 2(nd) IS for bleomycin complex A2/B2 is available from the European Directorate for the Quality of Medicines & HealthCare (EDQM).

  10. Evaluation of human exposure to complex waveform magnetic fields generated by arc-welding equipment according to European safety standards.

    PubMed

    Zoppetti, Nicola; Bogi, Andrea; Pinto, Iole; Andreuccetti, Daniele

    2015-02-01

    In this paper, a procedure is described for the assessment of human exposure to magnetic fields with complex waveforms generated by arc-welding equipment. The work moves from the analysis of relevant guidelines and technical standards, underlining their strengths and their limits. Then, the procedure is described with particular attention to the techniques used to treat complex waveform fields. Finally, the procedure is applied to concrete cases encountered in the workplace. The discussion of the results highlights the critical points in the procedure, as well as those related to the evolution of the technical and exposure standards.

  11. Evaluation of human exposure to complex waveform magnetic fields generated by arc-welding equipment according to European safety standards.

    PubMed

    Zoppetti, Nicola; Bogi, Andrea; Pinto, Iole; Andreuccetti, Daniele

    2015-02-01

    In this paper, a procedure is described for the assessment of human exposure to magnetic fields with complex waveforms generated by arc-welding equipment. The work moves from the analysis of relevant guidelines and technical standards, underlining their strengths and their limits. Then, the procedure is described with particular attention to the techniques used to treat complex waveform fields. Finally, the procedure is applied to concrete cases encountered in the workplace. The discussion of the results highlights the critical points in the procedure, as well as those related to the evolution of the technical and exposure standards. PMID:24936022

  12. Immediate Reconstruction of the Radiated Breast- Recent Trends Contrary to Traditional Standards

    PubMed Central

    Agarwal, Shailesh; Kidwell, Kelley M.; Farberg, Aaron; Kozlow, Jeffrey H.; Chung, Kevin C; Momoh, Adeyiza O.

    2016-01-01

    BACKGROUND Immediate, implant-only breast reconstruction is traditionally discouraged in patients who receive radiation. It is not clear however, whether this widely-recognized mantra of breast reconstruction is observed in practice. The aim of this study is to evaluate reconstruction trends and practices in patients who have undergone mastectomy and radiation therapy. METHODS Female patients with unilateral breast cancer who required radiation in addition to mastectomy were extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2000 through 2010. Patients who underwent immediate reconstruction were identified and analyzed. Univariable and multiple logistic regression analyses were performed to study the odds of implant or combined implant-tissue reconstruction over tissue only reconstruction based on demographic and oncologic characteristics. RESULTS A total of 5,481 female patients who underwent radiation and breast reconstruction were included for analysis. The reconstruction rate among patients requiring radiation increased from 13.6% to 25.1%. The percentage of reconstructed patients who had implant only reconstruction increased from 27% to 52% (p<0.001) with a decrease in tissue only reconstruction from 56% to 32% (, p<0.001); combined implant-tissue reconstructions remained stable at an average of 13%. In regression analysis, the odds of implant reconstruction over autologous reconstruction increased each year by an odds ratio of 1.13 (95% CI 1.10–1.15). CONCLUSIONS The frequency of immediate reconstruction continues to increase in the setting of radiation therapy with a larger proportion of patients undergoing immediate implant-based reconstruction, contrary to traditional recommendations. These findings likely reflect changing attitudes towards implant reconstruction in the setting of radiation. LEVEL OF EVIDENCE I PMID:25564172

  13. Combined radiation pressure and thermal modelling of complex satellites: algorithms and on-orbit tests

    NASA Astrophysics Data System (ADS)

    Ziebart, M.; Adhya, S.; Sibthorpe, A.; Edwards, S.; Cross, P.

    In an era of high resolution gravity field modelling the dominant error sources in spacecraft orbit determination are non-conservative spacecraft surface forces. These forces include: solar radiation pressure, thermal re-radiation forces, the forces due to radiation both reflected and emitted by the Earth and atmospheric drag effects. All of these forces can be difficult to characterise a priori because they require detailed modelling of the spacecraft geometry and surface properties, its attitude behaviour, the incident flux spatial and temporal variations and the interaction of these fluxes with the surface. The conventional approach to overcoming these problems is to build simplified box-and-wing models of the satellites and to estimate empirically factors that account for the inevitable mis-modelling. Over the last five years the authors have developed a suite of software utilities that model analytically the first three effects in the list above: solar radiation pressure, thermal forces and the albedo/earthshine force. The techniques are designed specifically to deal with complex spacecraft structures, no structural simplifications are made and the method can be applied to any spacecraft. Substantial quality control measures are used during computation to both avoid and trap errors. The paper presents the broad basis of the modelling techniques for each of the effects. Two operational tests of the output models, using the medium earth orbit satellite GPS Block IIR and the low earth orbit Jason-1, are presented. Model tests for GPS IIR are based on predicting the satellite orbit using the dynamic models alone (with no empirical scaling or augmentation) and comparing the integrated trajectory with precise, post-processed orbits. Using one month's worth of precise orbits, and all available Block IIR satellites, the RMS difference between the predicted orbits and the precise orbits over 12 hours are: 0.14m (height), 0.07m across track and 0.51m (along track). The

  14. A standard dose of radiation for microscopic disease is not appropriate

    SciTech Connect

    Marks, L.B. )

    1990-12-15

    Elective irradiation of sites of potential occult tumor spread is often part of a patient's radiation therapy program. The required radiation dose (D) depends on the probability that occult disease exists (P(occ)), the number of sites at risk (A), the number of tumor clonogens present (Ni), their radiation sensitivity, and the desired control rate. An exponential model of cell survival is used to quantify the importance of these factors. Control Probability = (1 - Pocc x (1 - e-Ni x (SF2)D/2))A; SF2 = surviving fraction after 2 Gy. Implications for clinical radiation therapy include: 1. Since the number of clonogens in an occult site may vary from 10 degrees to 10(8), Ni is the major determinant of the required dose. The intrinsic radiation sensitivity of the clonogens (SF2) is also extremely important in determining the dose. Other factors are less influential since they vary less. 2. The variability of Ni (8 logs) is larger than the variation in cell number seen with gross disease (1 cm3 versus 1000 cm3, 3 logs). When Ni approximately 10(8), the required dose approaches that needed for small volume gross disease (10(9) cells, 1 cm3). 3. The dose prescribed to elective sites should reflect the risk of occult disease based on the primary tumor site, stage, and grade. 4. Regions where clinicoradiologic evaluation is difficult (e.g., pelvis and obese neck) require higher doses because macroscopic tumor deposits may exist. 5. Relatively low doses (10 to 30 Gy) are often thought to be inadequate for microscopic tumor. However, similar doses have been reported to sterilize microscopic tumor in ovarian, rectal, bladder, breast, and head and neck carcinomas. Relatively low doses should not be discounted since they may be useful in select cases when normal tissue tolerances and/or previous irradiation treatment limit the radiation dose.

  15. Nanoantenna enhanced emission of light-harvesting complex 2: the role of resonance, polarization, and radiative and non-radiative rates.

    PubMed

    Wientjes, Emilie; Renger, Jan; Curto, Alberto G; Cogdell, Richard; van Hulst, Niek F

    2014-12-01

    Nanoantennae show potential for photosynthesis research for two reasons; first by spatially confining light for experiments which require high spatial resolution, and second by enhancing the photon emission of single light-harvesting complexes. For effective use of nanoantennae a detailed understanding of the interaction between the nanoantenna and the light-harvesting complex is required. Here we report how the excitation and emission of multiple purple bacterial LH2s (light-harvesting complex 2) are controlled by single gold nanorod antennae. LH2 complexes were chemically attached to such antennae, and the antenna length was systematically varied to tune the resonance with respect to the LH2 absorption and emission. There are three main findings. (i) The polarization of the LH2 emission is fully controlled by the resonant nanoantenna. (ii) The largest fluorescence enhancement, of 23 times, is reached for excitation with light at λ = 850 nm, polarized along the long antenna-axis of the resonant antenna. The excitation enhancement is found to be 6 times, while the emission efficiency is increased 3.6 times. (iii) The fluorescence lifetime of LH2 depends strongly on the antenna length, with shortest lifetimes of ∼40 ps for the resonant antenna. The lifetime shortening arises from an 11 times resonant enhancement of the radiative rate, together with a 2-3 times increase of the non-radiative rate, compared to the off-resonant antenna. The observed length dependence of radiative and non-radiative rate enhancement is in good agreement with simulations. Overall this work gives a complete picture of how the excitation and emission of multi-pigment light-harvesting complexes are influenced by a dipole nanoantenna.

  16. Natural element method for solving radiative transfer with or without conduction in three-dimensional complex geometries

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Ma, Yu; Yi, Hong-Liang; Tan, He-Ping

    2013-11-01

    A meshless method called as the natural element method (NEM) is developed for solving radiative heat transfer problem in 3D complex enclosures filled with an absorbing, emitting and scattering medium. The boundary surfaces are supposed to be opaque, diffuse as well as gray. The shape functions used in NEM are constructed by the natural neighbor interpolations, which are strictly interpolant and the essential boundary conditions can be imposed directly. The NEM solutions dealing with the radiative heat transfer with or without conduction are validated by comparison with some cases reported by the literature. Furthermore, the radiative heat transfer in cubic enclosures with or without an inner hollow sphere, cylinder and elliptical cylinder is also examined to demonstrate the applicability of the present method towards various three-dimensional geometries. For pure radiative transfer, both the cases of radiative non-equilibrium and radiative equilibrium are investigated. For combined conduction and radiation heat transfer, effects of various parameters such as the conduction-radiation parameter, the scattering albedo, the extinction coefficient, and the boundary emissivity are analyzed on the temperature distributions.

  17. Standard thermodynamic functions of complexation between copper(II) and glycine and L-histidine in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2016-09-01

    The Cu2+-glycine-L-histidine system is studied calorimetrically at 298.15 K and an ionic strength of 0.2, 0.5, and 1.0 in aqueous solutions containing potassium nitrate. The standard thermodynamic parameters (Δr H°, Δr G°, Δr S°) of complexation processes are determined.

  18. A Standard Setting Method Designed for Complex Performance Assessments with Multiple Performance Categories: Categorical Assignments of Student Work.

    ERIC Educational Resources Information Center

    Plake, Barbara S.; Hambleton, Ronald K.

    This paper reports on a standard-setting method designed for complex performance assessments with multiple performance categories. The method studied, the Analytical Judgment Method, involves panelists' making analytical classification decisions for each of the test's components individually. It also allows for discussion and reconsideration of…

  19. Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation

    SciTech Connect

    Csako, G.; Suba, E.A.; Ahlgren, A.; Tsai, C.M.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified US reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.

  20. Analysis of weekly complete blood counts in patients receiving standard fractionated partial body radiation therapy

    SciTech Connect

    Yang, F.E.; Ignacio, L.; Houghton, A.

    1995-10-15

    Hematopoiesis is among the most sensitive systems in the body to radiation. Routine complete blood counts (CBCs) are common in clinical radiotherapy practice. Only a few studies have attempted to characterize the behavior of peripheral blood levels during partial body radiation therapy with field sizes smaller than those used in hemibody or total nodal irradiation. Such information is needed to identify which patients are at risk for cytopenia and require close monitoring. Low CBC levels during radiation therapy are likely to be the result of other medical problems that cancer patients face. Regional irradiation with small field sizes (<40% of total body marrow) typically used in clinical radiotherapy is unlikely to be the cause of marrow depression significant enough to warrant medical intervention. Blood levels taken during the first week of treatment (Week 1) can be used to determine risks of developing critical nadirs. Localized breast and prostate cancer patients are unlikely to require routine CBCs if initial levels are normal. Routine CBC levels on all radiation oncology patients without other reasons for hematopoietic depression requires reevaluation, as millions of dollars are spent on unnecessary testing. If weekly CBC blood levels are avoided in localized breast and prostate cancer patients, this alone could potentially results in a savings of as much as $40 million a year nationally. 35 refs., 4 figs., 3 tabs.

  1. An EGS4 based mathematical phantom for radiation protection calculations using standard man

    SciTech Connect

    Wise, K.N.

    1994-11-01

    This note describes an Electron Gamma Shower code (EGS4) Monte Carlo program for calculating radiation transport in adult males and females from internal or external electron and gamma sources which requires minimal knowledge of organ geometry. Calculations of the dose from planar gamma fields and from computerized tomography illustrate two applications of the package. 25 refs., 5 figs.

  2. The JCMT Gould Belt Survey: evidence for radiative heating and contamination in the W40 complex

    NASA Astrophysics Data System (ADS)

    Rumble, D.; Hatchell, J.; Pattle, K.; Kirk, H.; Wilson, T.; Buckle, J.; Berry, D. S.; Broekhoven-Fiene, H.; Currie, M. J.; Fich, M.; Jenness, T.; Johnstone, D.; Mottram, J. C.; Nutter, D.; Pineda, J. E.; Quinn, C.; Salji, C.; Tisi, S.; Walker-Smith, S.; Francesco, J. Di; Hogerheijde, M. R.; Ward-Thompson, D.; Bastien, P.; Bresnahan, D.; Butner, H.; Chen, M.; Chrysostomou, A.; Coude, S.; Davis, C. J.; Drabek-Maunder, E.; Duarte-Cabral, A.; Fiege, J.; Friberg, P.; Friesen, R.; Fuller, G. A.; Graves, S.; Greaves, J.; Gregson, J.; Holland, W.; Joncas, G.; Kirk, J. M.; Knee, L. B. G.; Mairs, S.; Marsh, K.; Matthews, B. C.; Moriarty-Schieven, G.; Mowat, C.; Rawlings, J.; Richer, J.; Robertson, D.; Rosolowsky, E.; Sadavoy, S.; Thomas, H.; Tothill, N.; Viti, S.; White, G. J.; Wouterloot, J.; Yates, J.; Zhu, M.

    2016-08-01

    We present SCUBA-2 450 μm and 850 μm observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby star-forming regions. We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index, β = 1.8, and a beam convolution kernel to achieve a common 14.8 arcsec resolution. We identify 82 clumps ranging between 10 and 36 K with a mean temperature of 20 ± 3 K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust. We identify 31 clumps that have cores with densities greater than 105cm-3. 13 of these cores contain embedded Class 0/I protostars. Many cores are associated with bright-rimmed clouds seen in Herschel 70 μm images. From JCMT HARP observations of the 12CO 3-2 line, we find contamination of the 850 μm band of up to 20 per cent. We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact H II regions using archival VLA data and find the contribution is limited to individual stars, accounting for 9 per cent of flux per beam at 450 μm or 12 per cent at 850 μm in these cases. We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region, favouring Jeans stable clouds in the warm east and fragmentation in the cool west.

  3. Environmental standards for ionizing radiation: theoretical basis for dose-response curves.

    PubMed

    Upton, A C

    1983-10-01

    The types of injury attributable to ionizing radiation are subdivided, for purposes of risk assessment and radiological protection, into two broad categories: stochastic effects and nonstochastic effects. Stochastic effects are viewed as probablistic phenomena, varying in frequency but not severity as a function of the dose, without any threshold; nonstochastic effects are viewed as deterministic phenomena, varying in both frequency and severity as a function of the dose, with clinical thresholds. Included among stochastic effects are heritable effects (mutations and chromosome aberrations) and carcinogenic effects. Both types of effects are envisioned as unicellular phenomena which can result from nonlethal injury of individual cells, without the necessity of damage to other cells. For the induction of mutations and chromosome aberrations in the low-to-intermediate dose range, the dose-response curve with high-linear energy transfer (LET) radiation generally conforms to a linear nonthreshold relationship and varies relatively little with the dose rate. In contrast, the curve with low-LET radiation generally conforms to a linear-quadratic relationship, rising less steeply than the curve with high-LET radiation and increasing in slope with increasing dose and dose rate. The dose-response curve for carcinogenic effects varies widely from one type of neoplasm to another in the intermediate-to-high dose range, in part because of differences in the way large doses of radiation can affect the promotion and progression of different neoplasms. Information about dose-response relations for low-level irradiation is fragmentary but consistent, in general, with the hypothesis that the neoplastic transformation may result from mutation, chromosome aberration or genetic recombination in a single susceptible cell.

  4. Clinical comparison of brachytherapy versus hypofractionated external beam radiation versus standard fractionation external beam radiation for non-melanomatous skin cancers

    PubMed Central

    Haseltine, Justin M; Parker, Matthew; Wernicke, A. Gabriella; Nori, Dattatreyudu; Wu, Xian

    2016-01-01

    Purpose Non-melanomatous skin cancer (NMSC) is the single most common cancer in the US. Radiation therapy is an excellent treatment alternative to surgery. High-dose-rate (HDR) brachytherapy and external beam radiotherapy (EBRT) are commonly used radiation treatment modalities but little data is published comparing these modalities. We present our institution's experience and outcomes with these therapeutic options. Material and methods From June 2005 to March 2013, 61 patients were treated with HDR brachytherapy (n = 9), hypofractionated EBRT (n = 30), or standard fractionation EBRT (n = 22) for NMSC. The primary outcome measure was local control at most remote follow-up and secondary outcome measures were overall survival, cosmetic outcome, and toxicity. Univariate analysis was performed to compare outcomes between treatment modalities. Kaplan-Meier analysis and log-rank test were used to compare overall survival. Results Median follow-up was 30 months. The most common histologies were BCC (47%) and SCC (44%); mean patient age was 83.3 years. Local control was 81% and 2-year actuarial overall survival was 89%. There was no statistical difference in local control or overall survival between treatment modalities. There was no statistical difference in cosmetic outcome or toxicity between treatment modalities, although five of six “poor” cosmetic outcomes and the only grade 3 toxic events were found in the standard fractionation EBRT group. Conclusions All modalities investigated represent effective treatments for NMSC and have good cosmetic outcomes and acceptable toxicity profiles. The finding of higher grade toxicity and a greater portion of patients experiencing toxicity among standard fractionation therapy is counter to expectations. There was no statistical significance to the finding and it is not likely to be meaningful. PMID:27504127

  5. Low-intensity laser radiation in complex treatment of inflammatory diseases of parodontium

    NASA Astrophysics Data System (ADS)

    Sokolova, Irina A.; Erina, Stanislava V.

    1995-04-01

    The problem of complex treatment of inflammatory disease of parodontium has become very acute and actual at the moment. The diseases of inflammatory nature are considered to be the most vital issues of the day. The state of the local immune system of oral cavity plays the most important role in the complicated mechanism of inflammatory process development in the tissues of parodontium. Recently physical factors have become predominant in the system of complex therapy of parodontitis. The application of low-intense laser radiation (LLR) is considered to be the most important and up-to-date method in the preventive dentistry. There were 60 patients of average damage rate suffering from chronic generalizing parodontitis at the age of 25 up to 55 under observation. The major goal of examination was to get the objective results of the following methods' application: parodontium index (Russel, 1956), hygiene index (Fyodorov, Volodkina, 1971), Bacterioscopy of dental-gingival pockets content, simple and broadened stomatoscopy (Kunin, 1970), SIgA level determination in mixed saliva (Manchini et all, 1965) and R-protein level in gingival blood (Kulberg, 1990). All the patients were split into 2 groups. The first group (30 patients) has undergone the laser therapy course while the second group of 30 patients couldn't get it (LLR). Despite the kind of therapy they have undergone, all the patients have got the local anti-inflammatory medicamental therapy. The results of clinical observations have proved the fact that laser therapy application makes it possible to shorten the course of treatment in 1.5 times. The shifts of oral cavity local resistance take place in case of chronic generalizing parodontitis. The direct immunostimulating effect could be observed as a result of LLR- therapy application. The close connection of both anti-inflammatory medicamental and LLR-therapy has proved the possibility of purposeful local immune status correction in case of parodontitis.

  6. Investigation of vesicle-capsular plague antigen complex formation by elastic laser radiation scattering

    NASA Astrophysics Data System (ADS)

    Guseva, N. P.; Maximova, Irina S.; Romanov, Sergey V.; Shubochkin, L. P.; Tatarintsev, Sergey N.

    1991-05-01

    Recently a great deal of attention has been given to the investigation artificial lipid liposomes, due to their application as "containers" for directed transport of biologically active compounds into particular cells, organs and tissues for prophylaxis and therapy of infectious diseases. The use of traditional methods of liposome investigation, such as sedimentation, electrophoresis and chromatography is impeded by low liposome resistivity to different deformations. In conjunction with this, optical methods of laser light scattering are promising as they allow nondisturbing, precise and quick investigations. This paper describes the investigation of vesicle systems prepared from egg lecithin of Serva Corporation and their complexes with the capsular antigen of the plague microbe. The capsular antigen Fl was obtained from EV plague microbe grown at 37° C on Huttinger agar. Fl was isolated by gel-filtration on ASA-22 followed by freeze drying of the preparation. Angular dependences of polarized radiation scattering were measured for several liposome suspension samples in a saline solution before and after the interaction with the plague microbe capsular antigen. The aim of the investigation was to analyze the nature of mutual antigen arrangement in a liposome and to develop methods for measuring its inclusion percentage.

  7. Integrating Map Algebra and Statistical Modeling for Spatio-Temporal Analysis of Monthly Mean Daily Incident Photosynthetically Active Radiation (PAR) over a Complex Terrain

    PubMed Central

    Evrendilek, Fatih

    2007-01-01

    This study aims at quantifying spatio-temporal dynamics of monthly mean daily incident photosynthetically active radiation (PAR) over a vast and complex terrain such as Turkey. The spatial interpolation method of universal kriging, and the combination of multiple linear regression (MLR) models and map algebra techniques were implemented to generate surface maps of PAR with a grid resolution of 500 × 500 m as a function of five geographical and 14 climatic variables. Performance of the geostatistical and MLR models was compared using mean prediction error (MPE), root-mean-square prediction error (RMSPE), average standard prediction error (ASE), mean standardized prediction error (MSPE), root-mean-square standardized prediction error (RMSSPE), and adjusted coefficient of determination (R2adj.). The best-fit MLR- and universal kriging-generated models of monthly mean daily PAR were validated against an independent 37-year observed dataset of 35 climate stations derived from 160 stations across Turkey by the Jackknifing method. The spatial variability patterns of monthly mean daily incident PAR were more accurately reflected in the surface maps created by the MLR-based models than in those created by the universal kriging method, in particular, for spring (May) and autumn (November). The MLR-based spatial interpolation algorithms of PAR described in this study indicated the significance of the multifactor approach to understanding and mapping spatio-temporal dynamics of PAR for a complex terrain over meso-scales.

  8. [Levels of radiation exposure and radiation risk in flights aboard the orbital complex "Mir" and the International space station].

    PubMed

    Shafirkin, A V; Kolomenskiĭ, A V; Petrov, V M

    2001-01-01

    The paper presents results of calculating mean daily values of absorbed and equivalent doses from galactic cosmic rays (GCR) and Earth's radiation belts (ERB) to crew members on orbital missions aboard Mir and the International space station during solar minimum and maximum. Calculated doses were corrected in accordance with the dosimetric and spectrometric data from Mir missions 18 through to 23 that took place in the period of solar minimum. Contribution of local and albedo neutrons to equivalent dose was also taken into account. Presented are calculated total radiation risk and tumor risk over life time for Mir and ISS crews following missions of varying duration, and predictions for reduction in life span in view of recent dosimetric data. PMID:11840866

  9. History of the development of radiation protection standards for space activities

    SciTech Connect

    Sinclair, W.K.

    1997-04-30

    Initial recommendations for limitations on radiation exposures in space were made in 1970 by the Radiobiological Advisory Panel of the Committee on Space Medicine, National Academy of Sciences/National Research Council (NAS/NRC). Using a risk-based approach and taking into consideration a range of factors, the Panel recommended an overall career limit of 4 Sv. Because it was assumed that only small numbers of people would be involved, most of whom would be in excess of 30 y of age, the question of genetic effects did not appear to be of concern. On the basis of subsequent epidemiological findings, the values of the risk coefficients were increased. As a result of this and other considerations, NASA in the early 1980s asked the NCRP to re-examine both the risks and the philosophy for protecting astronauts. In undertaking this task, the NCRP decided to treat the radiation exposures of crew members and payload specialists as an occupational hazard and to evaluate their risks in terms of those to radiation workers and to workers in other industries. Noting that in the less safe but not the most hazardous occupations, workers had an average lifetime risk of mortality of about three percent, the NCRP concluded that a reasonable career limit for astronauts should be based on a lifetime absolute excess risk of mortality of three percent. Using this as a base, the NCRP recommended a career limit for 25 y olds of 1 Sv for females and 1.5 Sv for males. Since the risk decreases the older the age at which the exposures begin, the limits culminated with a career limit of 3 Sv for females and 4 Sv for males whose initial exposure occurred at age 55. These recommendations were based on an assumed nominal value of a lifetime risk of fatal cancers for all ages of about 2 {times} 10{sup -2} Sv{sup -1}.

  10. Viable dark matter via radiative symmetry breaking in a scalar singlet Higgs portal extension of the standard model.

    PubMed

    Steele, T G; Wang, Zhi-Wei; Contreras, D; Mann, R B

    2014-05-01

    We consider the generation of dark matter mass via radiative electroweak symmetry breaking in an extension of the conformal standard model containing a singlet scalar field with a Higgs portal interaction. Generating the mass from a sequential process of radiative electroweak symmetry breaking followed by a conventional Higgs mechanism can account for less than 35% of the cosmological dark matter abundance for dark matter mass M(s)>80 GeV. However, in a dynamical approach where both Higgs and scalar singlet masses are generated via radiative electroweak symmetry breaking, we obtain much higher levels of dark matter abundance. At one-loop level we find abundances of 10%-100% with 106 GeV80 GeV detection region of the next generation XENON experiment.

  11. Polyethylene as a Radiation Shielding Standard in SimulatedCosmic-Ray Environments

    SciTech Connect

    Guetersloh, Stephen B.; Zeitlin, Cary; Heilbronn, Lawrence H.; Miller, Jack; Komiyama, Tatsudo; Fukumura, A.; Iwata, Y.; Murakami, T.; Bhattacharya M.

    2006-08-19

    Radiation risk management for human space missions dependson accurate modeling of high-energy heavy ion transport in matter. Theprocess of nuclear fragmentation can play a key role in reducing both thephysical dose and the biological effectiveness of the radiationencountered in deep space. Hydrogenous materials and light elements areexpected to be more effective shields against the deleterious effects ofGalactic Cosmic Rays (GCR) than aluminum, which is used in currentspacecraft hulls. NASA has chosen polyethylene, CH2, as the referencematerial for accelerator-based radiation testing of multi-functioncomposites that are currently being developed. A detailed discussion ofthe shielding properties of polyethylene under a variety of relevantexperimental conditions is presented, along with Monte Carlo simulationsof the experiments and other Monte Carlo calculations in which the entireGCR flux is simulated. The Monte Carlo results are compared to theaccelerator data and we assess the usefulness of 1 GeV/amu 56Fe as aproxy for GCR heavy ions. We conclude that additional accelerator-basedmeasurements with higher beam energies would be useful.

  12. Application of ISO standard 27048: dose assessment for the monitoring of workers for internal radiation exposure.

    PubMed

    Henrichs, K

    2011-03-01

    Besides ongoing developments in the dosimetry of incorporated radionuclides, there are various efforts to improve the monitoring of workers for potential or real intakes of radionuclides. The disillusioning experience with numerous intercomparison projects identified substantial differences between national regulations, concepts, applied programmes and methods, and dose assessment procedures. Measured activities were not directly comparable because of significant differences between measuring frequencies and methods, but also results of case studies for dose assessments revealed differences of orders of magnitude. Besides the general common interest in reliable monitoring results, at least the cross-border activities of workers (e.g. nuclear power plant services) require consistent approaches and comparable results. The International Standardization Organization therefore initiated projects to standardise programmes for the monitoring of workers, the requirements for measuring laboratories and the processes for the quantitative evaluation of monitoring results in terms of internal assessed doses. The strength of the concepts applied by the international working group consists in a unified approach defining the requirements, databases and processes. This paper is intended to give a short introduction into the standardization project followed by a more detailed description of the dose assessment standard, which will be published in the very near future. PMID:21212077

  13. Neuropsychological Outcome of Children Treated for Standard Risk Medulloblastoma in the PNET4 European Randomized Controlled Trial of Hyperfractionated Versus Standard Radiation Therapy and Maintenance Chemotherapy

    SciTech Connect

    Câmara-Costa, Hugo; Resch, Anika; Kieffer, Virginie; Lalande, Clémence; Poggi, Geraldina; Kennedy, Colin; Bull, Kim; Calaminus, Gabriele; Grill, Jacques; Doz, François; Rutkowski, Stefan; Massimino, Maura; Kortmann, Rolf-Dieter; Lannering, Birgitta; Dellatolas, Georges; Chevignard, Mathilde

    2015-08-01

    Purpose: In the European HIT-SIOP PNET4 randomized controlled trial, children with standard risk medulloblastoma were allocated to hyperfractionated radiation therapy (HFRT arm, including a partially focused boost) or standard radiation therapy (STRT arm), followed, in both arms, by maintenance chemotherapy. Event-free survival was similar in both arms. Previous work showed that the HFRT arm was associated with worse growth and better questionnaire-based executive function, especially in children <8 years of age at diagnosis. Therefore, the aim of this study was to compare performance-based cognitive outcomes between treatment arms. Methods and Materials: Neuropsychological data were collected prospectively in 137 patients. Using the Wechsler Intelligence Scales, Kaufman Assessment Battery for Children, and Raven's Progressive Matrices, we estimated full-scale intelligence quotient (FSIQ) and, when available, verbal IQ (VIQ), performance IQ (PIQ), working memory index (WMI), and processing speed index (PSI). Results: Among the 137 participants (HFRT arm n=71, STRT arm n=66, 63.5% males), mean (±SD) ages at diagnosis and assessment respectively were 9.3 (±3.2) years of age (40.8% < 8 years of age at diagnosis) and 14.6 (±4.3) years of age. Mean (±SD) FSIQ was 88 (±19), and mean intergroup difference was 3.88 (95% confidence interval: −2.66 to 10.42, P=.24). No significant differences were found in children >8 years of age at diagnosis. In children <8 years of age at diagnosis, a marginally significant trend toward higher VIQ was found in those treated in the HFRT arm; a similar trend was found for PSI but not for PIQ, WMI, or FSIQ (mean intergroup differences were: 12.02 for VIQ [95% CI: 2.37-21.67; P=.02]; 3.77 for PIQ [95% CI: −5.19 to 12.74; P>.10]; 5.20 for WMI [95% CI: −2.07 to 12.47; P>.10]; 10.90 for PSI [95% CI: −1.54 to 23.36; P=.08]; and 5.28 for FSIQ [95% CI: −4.23 to 14.79; P>.10]). Conclusions: HFRT was associated with marginally

  14. The diverse and complex roles of radiation on cancer treatment: therapeutic target and genome maintenance

    PubMed Central

    Baskar, Rajamanickam; Yap, Swee Peng; Chua, Kevin Lee Min; Itahana, Koji

    2012-01-01

    Cancer is a genetic disease, grows exponentially with the development of intrinsic and acquired treatment resistance. Past decade has witnessed a considerable progress towards the treatment and understanding of proposed hallmarks of cancer and together with advances in early detection and various treatment modalities. Radiation therapy is an integral part of cancer treatment armamentarium. In developed countries more than half of all cancer patients receive radiation therapy during their course of illness. Although radiation damages both cancer and normal cells, the goal of radiation therapy is to maximize the radiation dose to abnormal cancer cells while minimizing exposure to normal cells, which is adjacent to cancer cells or in the path of radiation. In recent years, life expectancy increases among cancer patients and this increase is due to the results of early diagnosis, screening efforts, improved treatments and with less late effects mostly secondary cancer development. Therefore, cancer survivorship issues have been gaining prominence in the area of radiation oncology research. Understanding the tradeoff between the expected decreases in normal tissue toxicity resulting from an improved radiation dose distribution to the targeted site is an increasingly pertinent, yet needed attention and research in the area of radiation oncology. In recent years, a number of potential molecular targets that involve either with radiation increased tumor cell killing or protecting normal cells have been identified. For clinical benefits, translating these findings to maximize the toxicity of radiation on tumor cells while safeguarding early or late normal cell toxicities using molecular targeted radioprotectors will be useful in radiation treatment. PMID:22860229

  15. Average radiation doses in a standard head examination for 250 CT systems

    SciTech Connect

    McCrohan, J.L.; Patterson, J.F.; Gagne, R.M.; Goldstein, H.A.

    1987-04-01

    Approximately 250 computed tomography (CT) systems were surveyed in a nationwide study to determine the average radiation dose resulting from a typical adult head procedure. The multiple scan average dose (MSAD) was selected as the dose descriptor. For the typical adult CT head procedure, the MSAD was generally within 2.2-6.8 rads (22-68 mGy). Variations in dose by a factor of two or more were often seen for a given manufacturer and model. These dose ranges indicate a potential to reduce dose by carefully selecting imaging techniques. Overall, variations in dose can result from differences in the user's choice of technique (desired image quality) or from actual differences in scanner performance (caused by differences in collimation, filtration, or geometry). To use CT appropriately, a facility should consider dose as well as image quality in selecting optimal techniques for typical modes of operation.

  16. Average radiation doses in a standard head examination for 250 CT systems.

    PubMed

    McCrohan, J L; Patterson, J F; Gagne, R M; Goldstein, H A

    1987-04-01

    Approximately 250 computed tomography (CT) systems were surveyed in a nationwide study to determine the average radiation dose resulting from a typical adult head procedure. The multiple scan average dose (MSAD) was selected as the dose descriptor. For the typical adult CT head procedure, the MSAD was generally within 2.2-6.8 rads (22-68 mGy). Variations in dose by a factor of two or more were often seen for a given manufacturer and model. These dose ranges indicate a potential to reduce dose by carefully selecting imaging techniques. Overall, variations in dose can result from differences in the user's choice of technique (desired image quality) or from actual differences in scanner performance (caused by differences in collimation, filtration, or geometry). To use CT appropriately, a facility should consider dose as well as image quality in selecting optimal techniques for typical modes of operation.

  17. Investigation of plague lipopolysaccharide complex formation with artificial phospholipid vesicles by elastic laser radiation scattering

    NASA Astrophysics Data System (ADS)

    Gusev, V. V.; Guseva, N. P.; Tatarintsev, S. N.

    1995-01-01

    This paper describes the investigation of incorporation processes of the plague lipopolysaccharide (LPS) into artificial phospholipid vesicles (PLV) on the basis of elastic laser radiation scattering. For this purpose, the angular light scattering dependencies of PLV suspensions, containing various LPS concentrations (0 - 5 mg/ml), were measured using the polarization nephelometer. The design of the polarization nephelometer and the measurement technique are described in detail. Measuring results are compared with electron microscopy data. The most pronounced variation as a result of LPS incorporation into PLV appeared to be the light scattering integral intensity (LSII) at angles exceeding 100. It is shown that the LPS adding into the PLV suspension causes the LSII to increase by a factor 2 - 6 for a LPS concentration range from 0.5 to 5 mg/ml as compared with `empty' PLV. Proceeding from the electron microscopy data it was found that the LSII increase, in general case, is conditioned by variation of the PLV membrane refraction index and formation of PLV aggregates. It was shown that the LSII measurement for the PLV suspension containing LPS can be used as a qualitative express analysis for the LPS incorporation into PLV as well as procedure for determination of the aggregate formation stage from PLV. The LPS of the plague, which as determinants being common for various gram-negative bacteria, is of great interest from the viewpoint of creating preparations for prophylactic measures against the endotoxin infections. However, the LPS toxicity due to the lipid A presence is a disadvantage of this weak antigen. Incorporation of the LPS int bilayer phospholipid membranes leads to its lower toxicity and higher immunization ability. The immunization ability and toxicity of the LPS complexes with bilayer membranes depend essentially on the LPS quantity sorbed in the membrane, as well as on the shapes and sizes of aggregates formed by the LPS and membranes in water

  18. The development of a single molecule fluorescence standard and its application in estimating the stoichiometry of the nuclear pore complex.

    PubMed

    Tie, Hieng Chiong; Madugula, Viswanadh; Lu, Lei

    2016-09-30

    We report here an image-based method to quantify the stoichiometry of diffraction-limited sub-cellular protein complexes in vivo under spinning disk confocal microscopy. A GFP single molecule fluorescence standard was first established by immobilizing His-tagged GFP molecules onto the glass surface via nickel nitrilotriacetic acid functionalized polyethylene glycol. When endogenous nucleoporins were knocked down and replaced by the exogenously expressed and knockdown-resistant GFP-nucleoporins, the stoichiometry of the nucleoporin was estimated by the ratio of its fluorescence intensity to that of the GFP single molecules. Our measured stoichiometry of Nup35, Nup93, Nup133 and Nup88 is 23, 18, 14 and 9 and there are possibly16 copies of Nup107-160 complex per nuclear pore complex.

  19. The development of a single molecule fluorescence standard and its application in estimating the stoichiometry of the nuclear pore complex.

    PubMed

    Tie, Hieng Chiong; Madugula, Viswanadh; Lu, Lei

    2016-09-30

    We report here an image-based method to quantify the stoichiometry of diffraction-limited sub-cellular protein complexes in vivo under spinning disk confocal microscopy. A GFP single molecule fluorescence standard was first established by immobilizing His-tagged GFP molecules onto the glass surface via nickel nitrilotriacetic acid functionalized polyethylene glycol. When endogenous nucleoporins were knocked down and replaced by the exogenously expressed and knockdown-resistant GFP-nucleoporins, the stoichiometry of the nucleoporin was estimated by the ratio of its fluorescence intensity to that of the GFP single molecules. Our measured stoichiometry of Nup35, Nup93, Nup133 and Nup88 is 23, 18, 14 and 9 and there are possibly16 copies of Nup107-160 complex per nuclear pore complex. PMID:27613095

  20. SU-E-P-22: AAPM Task Group 263 Tackling Standardization of Nomenclature for Radiation Therapy

    SciTech Connect

    Matuszak, M; Feng, M; Moran, J; Xiao, Y; Mayo, C; Miller, R; Bosch, W; Popple, R; Marks, L; Wu, Q; Molineu, A; Martel, M; Yock, T; McNutt, T; Brown, N; Purdie, T; Yorke, E; Santanam, L; Gabriel, P; Michalski, J; and others

    2015-06-15

    Purpose: There is growing recognition of need for increased clarity and consistency in the nomenclatures used for body and organ structures, DVH metrics, toxicity, dose and volume units, etc. Standardization has multiple benefits; e.g. facilitating data collection for clinical trials, enabling the pooling of data between institutions, making transfers (i.e. hand-offs) between centers safer, and enabling vendors to define “default” settings. Towards this goal, the American Association of Physicists in Medicine (AAPM) formed a task group (TG263) in July of 2014, operating under the Work Group on Clinical Trials to develop consensus statements. Guiding principles derived from the investigation and example nomenclatures will be presented for public feedback. Methods: We formed a multi-institutional and multi-vendor collaborative group of 39 physicists, physicians and others involved in clinical use and electronic transfer of information. Members include individuals from IROC, NRG, IHE-RO, DICOM WG-7, ASTRO and EORTC groups with overlapping interests to maximize the quality of the consensus and increase the likelihood of adoption. Surveys of group and NRG members were used to define current nomenclatures and requirements. Technical requirements of vendor systems and the proposed DICOM standards were examined. Results: There is a marked degree of inter and intra institutional variation in current approaches, resulting from inter-vendor differences in capabilities, clinic specific conceptualizations and inconsistencies. Using a consensus approach, the group defined optimal formats for the naming of targets and normal structures. A formal objective assessment of 13 existing clinically-used software packages show that all had capabilities to accommodate these recommended nomenclatures. Conclusions: A multi-stakeholder effort is making significant steps forward in developing a standard nomenclature that will work across platforms. Our current working list includes > 550

  1. Chaos and Complexities Theories. Superposition and Standardized Testing: Are We Coming or Going?

    ERIC Educational Resources Information Center

    Erwin, Susan

    2005-01-01

    The purpose of this paper is to explore the possibility of using the principle of "superposition of states" (commonly illustrated by Schrodinger's Cat experiment) to understand the process of using standardized testing to measure a student's learning. Comparisons from literature, neuroscience, and Schema Theory will be used to expound upon the…

  2. Impact of ASTM Standard E722 update on radiation damage metrics.

    SciTech Connect

    DePriest, Kendall Russell

    2014-06-01

    The impact of recent changes to the ASTM Standard E722 is investigated. The methodological changes in the production of the displacement kerma factors for silicon has significant impact for some energy regions of the 1-MeV(Si) equivalent fluence response function. When evaluating the integral over all neutrons energies in various spectra important to the SNL electronics testing community, the change in the response results in an increase in the total 1-MeV(Si) equivalent fluence of 2 7%. Response functions have been produced and are available for users of both the NuGET and MCNP codes.

  3. Radiation

    NASA Video Gallery

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  4. Biological Complexities in Radiation Carcinogenesis and Cancer Radiotherapy: Impact of New Biological Paradigms

    PubMed Central

    Mozdarani, Hossein

    2012-01-01

    Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity). It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation therapy, all these

  5. Variations in the radiation sensitivity of foodborne pathogens associated with complex ready-to-eat food products

    NASA Astrophysics Data System (ADS)

    Sommers, Christopher H.; Boyd, Glenn

    2006-07-01

    Foodborne illness outbreaks and product recalls are occasionally associated with ready-to-eat (RTE) sandwiches and other "heat and eat" multi-component RTE products. Ionizing radiation can inactivate foodborne pathogens on meat and poultry, fruits and vegetables, seafood, and RTE meat products. However, less data are available on the ability of low-dose ionizing radiation, doses under 5 kGy typically used for pasteurization purposes, to inactivate pathogenic bacteria on complex multi-component food products. In this study, the efficacy of ionizing radiation to inactivate Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Yersinia enterocolitica on RTE foods including a "frankfurter on a roll", a "beef cheeseburger on a bun" and a "vegetarian cheeseburger on a bun" was investigated. The average D-10 values, the radiation dose needed to inactivate 1 log 10 of pathogen, by bacterium species, were 0.61, 0.54, 0.47, 0.36 and 0.15 kGy for Salmonella spp., S. aureus, L. monocytogenes, E. coli O157:H7, and Y. enterocolitica, respectively when inoculated onto the three product types. These results indicate that irradiation may be an effective means for inactivating common foodborne pathogens including Salmonella spp, S. aureus, L. monocytogenes, E. coli O157:H7 and Y. enterocolitica in complex RTE food products such as 'heat and eat" sandwich products.

  6. Ethylene vinyl acetate based radiation grafted hydrophilic matrices: Process parameter standardization, grafting kinetics and characterization

    NASA Astrophysics Data System (ADS)

    Chaudhari, C. V.; Mondal, R. K.; Dubey, K. A.; Grover, V.; Panicker, L.; Bhardwaj, Y. K.; Varshney, L.

    2016-08-01

    A transparent, elastomeric, grafted matrix for several potential applications was synthesized by single-step simultaneous radiation grafting of methacrylic acid onto ethylene vinyl acetate (EVA). CuSO4 was found to be the most suitable homo-polymerization inhibitor among different inhibitors tried. The grafting kinetics was found to be a strong function of dose rate (D) and monomer content (M) and an equation relating grafting rate Rg=Kg [M]1.13D0.23 was deduced. Crystallinity of the grafted matrices as assessed from XRD and DSC measurements indicated decrease in crystalline content with increase in grafting yield, suggesting crystalline domain of EVA get disrupted on grafting. Elastic modulus increased linearly with the increase in grafting yield, though elongation at break decreased precipitously from 900% to 30% at even ~9% grafting. Thermo-gravimetric analysis showed three step weight loss of the grafted EVA matrix. The grafting of MAA resulted in increase in surface energy mainly due to enhanced polar component.

  7. Station coordinates in the standard earth 3 system and radiation-pressure perturbations from ISAGEX camera data

    NASA Technical Reports Server (NTRS)

    Gaposchkin, E. M.; Latimer, J.; Mendes, G.

    1975-01-01

    Simultaneous and individual camera observations of GEOS 1, GEOS 2, Pageos, and Midas 4 obtained during the International Satellite Geodesy Experiment are utilized to determine station coordinates. The Smithsonian Astrophysical Observatory Standard Earth III system of coordinates is used to tie the geometrical network to a geocentric system and as a reference for calculating satellite orbits. A solution for coordinates combining geometrical and dynamical methods is obtained, and a comparison between the solutions and terrestrial data is made. The radiation-pressure and earth-albedo perturbations for Pageos are very large, and Pageos' orbits are used to evaluate the analytical treatment of these perturbations. Residual effects, which are probably of interest to aeronomists, remain in the Pageos orbits.

  8. Beryllium Sampling and Analysis Within the DOE Complex and Opportunities for Standardization

    SciTech Connect

    BRISSON, MICHAEL

    2005-01-25

    Since the U. S. Department of Energy (DOE) published the DOE Beryllium Rule (10 CFR 850) in 1999, DOE sites have been required to measure beryllium on air filters and wipes for worker protection and for release of materials from beryllium-controlled areas. Measurements in the nanogram range on a filter or wipe are typically required. Industrial hygiene laboratories have applied methods from various analytical compendia, and a number of issues have emerged with sampling and analysis practices. As a result, a committee of analytical chemists, industrial hygienists, and laboratory managers was formed in November 2003 to address the issues. The committee developed a baseline questionnaire and distributed it to DOE sites and other agencies in the U.S. and U.K. The results of the questionnaire are presented in this paper. These results confirmed that a wide variety of practices were in use in the areas of sampling, sample preparation, and analysis. Additionally, although these laboratories are generally accredited by the American Industrial Hygiene Association (AIHA), there are inconsistencies in performance among accredited labs. As a result, there are significant opportunities for development of standard methods that could improve consistency. The current availabilities and needs for standard methods are further discussed in a companion paper.

  9. COOMET regional comparison of national measurement standards of air kerma for 137Cs γ radiation at protection level

    NASA Astrophysics Data System (ADS)

    Büermann, L.; Oborin, A. V.; Milevsky, V. S.; Walwyn Salas, G.; Sukhishvili, S.; Ginga, I.; Ivanov, R.; Gudelis, A.; Gomola, I.

    2014-01-01

    Results are presented of the COOMET supplementary comparison of the national measurement standards for air kerma in 137Cs γ radiation at protection level (~10 mGy/h). Ten National Metrology Institutes from the COOMET organization and the International Atomic Energy Agency participated in this COOMET project no. 445. The PTB acted as pilot laboratory. Two of the participants, the SMU (Slovakia) and the NSC-'IM' (Ukraine) participated in the measurements but did not submit a valid report of results. The comparison reference value (CRV) was obtained as the mean result of the PTB and the VNIIM, both of which had previously taken part in the key comparison BIPM-RI(I)-K5. The degree of equivalence with the CRV was evaluated. The results were consistent within the relative standard uncertainties of the comparison ranging from 0.28% to 1.3% and deviated from the CRV by less than 1%. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. Prediction of radiation ratio and sound transmission of complex extruded panel using wavenumber domain Unite element and boundary element methods

    NASA Astrophysics Data System (ADS)

    Kim, H.; Ryue, J.; Thompson, D. J.; Müller, A. D.

    2016-09-01

    Recently, complex shaped aluminium panels have been adopted in many structures to make them lighter and stronger. The vibro-acoustic behaviour of these complex panels has been of interest for many years but conventional finite element and boundary element methods are not efficient to predict their performance at higher frequencies. Where the cross-sectional properties of the panels are constant in one direction, wavenumber domain numerical analysis can be applied and this becomes more suitable for panels with complex cross-sectional geometries. In this paper, a coupled wavenumber domain finite element and boundary element method is applied to predict the sound radiation from and sound transmission through a double-layered aluminium extruded panel, having a typical shape used in railway carriages. The predicted results are compared with measured ones carried out on a finite length panel and good agreement is found.

  11. Development and Use of Engineering Standards for Computational Fluid Dynamics for Complex Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Lee, Hyung B.; Ghia, Urmila; Bayyuk, Sami; Oberkampf, William L.; Roy, Christopher J.; Benek, John A.; Rumsey, Christopher L.; Powers, Joseph M.; Bush, Robert H.; Mani, Mortaza

    2016-01-01

    Computational fluid dynamics (CFD) and other advanced modeling and simulation (M&S) methods are increasingly relied on for predictive performance, reliability and safety of engineering systems. Analysts, designers, decision makers, and project managers, who must depend on simulation, need practical techniques and methods for assessing simulation credibility. The AIAA Guide for Verification and Validation of Computational Fluid Dynamics Simulations (AIAA G-077-1998 (2002)), originally published in 1998, was the first engineering standards document available to the engineering community for verification and validation (V&V) of simulations. Much progress has been made in these areas since 1998. The AIAA Committee on Standards for CFD is currently updating this Guide to incorporate in it the important developments that have taken place in V&V concepts, methods, and practices, particularly with regard to the broader context of predictive capability and uncertainty quantification (UQ) methods and approaches. This paper will provide an overview of the changes and extensions currently underway to update the AIAA Guide. Specifically, a framework for predictive capability will be described for incorporating a wide range of error and uncertainty sources identified during the modeling, verification, and validation processes, with the goal of estimating the total prediction uncertainty of the simulation. The Guide's goal is to provide a foundation for understanding and addressing major issues and concepts in predictive CFD. However, this Guide will not recommend specific approaches in these areas as the field is rapidly evolving. It is hoped that the guidelines provided in this paper, and explained in more detail in the Guide, will aid in the research, development, and use of CFD in engineering decision-making.

  12. Aspects of Radiation Budget, Subsurface Lateral Moisture Exchange, and Vegetation Function in Areas of Complex Topography.

    NASA Astrophysics Data System (ADS)

    Ivanov, V. Y.; Bras, R. L.; Istanbulluoglu, E.; Vivoni, E. R.

    2004-12-01

    There is evidence that topography strongly affects the state, function, and distribution of vegetation by controlling incoming solar radiation and lateral redistribution of soil moisture. However, numerical experiments studying the effects that a topography can have on vegetation have oversimplified the treatment of topography and/or the representation of vegetation. We investigate the control of topography on vegetation state and stress via detailed modeling of radiation and soil moisture budgets across the varied terrain of a watershed. A detailed vegetation-hydrology model parameterizes the processes of canopy radiative transfer and rainfall interception and couples the processes of infiltration and evapotranspiration to photosynthesis via moisture uptake through a root systems with varied profiles. The model is applied on a continuous basis to synthetic watersheds of topography dominated by either convex or concave hillslopes. The numerical analysis is carried out for several plant functional types and soils. Inferences from the spatially-distributed dynamics are used to examine topographic niches favorable to vegetation.

  13. SU-E-T-353: Decoding the Beam Complexity in Intensity-Modulated Radiation Therapy Plans

    SciTech Connect

    Du, W; Cho, S; Zhang, X; Hoffman, K; Kudchadker, R

    2014-06-01

    Purpose: Modern IMRT relies on computers to generate treatment plans of varied complexity. A highly complex treatment plan may use a large number of small and irregular beam apertures in order to achieve high dose conformity. However, excessive beam complexity can increase dosimetric uncertainty, prolong treatment time, and increase susceptibility to target or organ motion. In this study we sought to develop metrics to assess the complexity of IMRT beams and plans. Methods: Based the information of leaf positions and MU for each beam segment, we calculated the following beam complexity metrics: aperture area, shape irregularity, and beam modulation. Then these beam complexity metrics were averaged to obtain the corresponding plan complexity metrics, using the beam MUs as weighting factors. We evaluated and compared the beam and plan complexity scores for 65 IMRT plans from 3 sites (prostate, head and neck, and spine). We also studied how the plan complexity scores were affected by adjusting inverse planning parameters. Results: For prostate IMRT, the lateral beams had large MUs and smaller shape irregularity, while the anterior or posterior beams had larger modulation values. On average, the prostate IMRT plans had the smallest shape irregularity and beam modulation; the HN IMRT plans had the largest aperture area, shape irregularity, and beam modulation; and the spine stereotactic IMRT plans often had small aperture area, which may be associated with relatively large discrepancies between calculated and measures doses. The plan complexity increased as the number of optimization iterations and the number of beam segments increased and as the minimum segment area decreased. Conclusion: Complexity of IMRT beams and plans were quantified in terms of aperture area, shape irregularity and beam modulation. The complexity metrics varied among IMRT plans for different disease sites and were affected when the planning parameters were adjusted.

  14. Using Next Generation Science Standards (NGSS) Practices to Address Scientific Misunderstandings Around Complex Environmental Issues

    NASA Astrophysics Data System (ADS)

    Turrin, M.; Kenna, T. C.

    2014-12-01

    The new NGSS provide an important opportunity for scientists to develop curriculum that links the practice of science to research-based data in order to improve understanding in areas of science that are both complex and confusing. Our curriculum focuses in particular on the fate and transport of anthropogenic radionuclides. Radioactivity, both naturally occurring and anthropogenic, is highly debated and largely misunderstood, and for large sections of the population is a source of scientific misunderstanding. Developed as part of the international GEOTRACES project which focuses on identifying ocean processes and quantifying fluxes that control the distributions of selected trace elements and isotopes in the ocean, and on establishing the sensitivity of these distributions to changing environmental conditions, the curriculum topic fits nicely into the applied focus of NGSS with both environmental and topical relevance. Our curriculum design focuses on small group discussion driven by questions, yet unlike more traditional curriculum pieces these are not questions posed to the students, rather they are questions posed by the students to facilitate their deeper understanding. Our curriculum design challenges the traditional question/answer memorization approach to instruction as we strive to develop an educational approach that supports the practice of science as well as the NGSS Cross Cutting Concepts and the Science & Engineering Practices. Our goal is for students to develop a methodology they can employ when faced with a complex scientific issue. Through background readings and team discussions they identify what type of information is important for them to know and where to find a reliable source for that information. Framing their discovery around key questions such as "What type of radioactive decay are we dealing with?", "What is the potential half-life of the isotope?", and "What are the pathways of transport of radioactivity?" allows students to evaluate a

  15. Regulation of ionizing radiation-induced apoptosis by a manganese porphyrin complex

    SciTech Connect

    Lee, Jin Hyup; Lee, You Mie; Park, Jeen-Woo . E-mail: parkjw@knu.ac.kr

    2005-08-26

    Ionizing radiation induces the production of reactive oxygen species, which play an important causative role in apoptotic cell death. Therefore, compounds that scavenge reactive oxygen species may confer regulatory effects on apoptosis. Superoxide dismutase (SOD) mimetics have been shown to be protective against cell injury caused by reactive oxygen species. We investigated the effects of the manganese (III) tetrakis(N-methyl-2-pyridyl)porphyrin (MnTMPyP), a cell-permeable SOD mimetic, on ionizing radiation-induced apoptosis. Upon exposure to 2 Gy of {gamma}-irradiation, there was a distinct difference between the control cells and the cells pre-treated with 5 {mu}M MnTMPyP for 2 h with regard to apoptotic parameters, cellular redox status, mitochondria function, and oxidative damage to cells. MnTMPyP effectively suppressed morphological evidence of apoptosis and DNA fragmentation in U937 cells exposed to ionizing radiation. The [GSSG]/[GSH + GSSG] ratio and the generation of intracellular reactive oxygen species were higher and the [NADPH]/[NADP{sup +} + NADPH] ratio was lower in control cells compared to MnTMPyP-treated cells. The ionizing radiation-induced mitochondrial damage reflected by the altered mitochondrial permeability transition, the increase in the accumulation of reactive oxygen species, and the reduction of ATP production were significantly higher in control cells compared to MnTMPyP-treated cells. MnTMPyP pre-treated cells showed significant inhibition of apoptotic features such as activation of caspase-3, up-regulation of Bax and p53, and down-regulation of Bcl-2 compared to control cells upon exposure to ionizing radiation. This study indicates that MnTMPyP may play an important role in regulating the apoptosis induced by ionizing radiation presumably through scavenging of reactive oxygen species.

  16. Computing the complex : Dusty plasmas in the presence of magnetic fields and UV radiation

    NASA Astrophysics Data System (ADS)

    Land, V.

    2007-12-01

    About 90% of the visible universe is plasma. Interstellar clouds, stellar cores and atmospheres, the Solar wind, the Earth's ionosphere, polar lights, and lightning are all plasma; ionized gases, consisting of electrons, ions, and neutrals. Not only many industries, like the microchip and solar cell industry, but also future fusion power stations, rely heavily on the use of plasma. More and more, home appliances include plasma technologies, like compact fluorescent light sources, and plasma screens. Dust particles, which can disrupt plasma processes, enter these plasmas, through chemical reactions in the plasma, or through interactions between plasma and walls. For instance, during microchip fabrication, dust particles can destroy the tiny, nanometre-sized structures on the surface of these chips. On the other hand, dust particles orbiting Young Stellar Objects coagulate and form the seeds of planets. In order to understand fundamental processes, such as planet formation, or to optimize industrial plasma processes, a thorough description of dusty plasma is necessary. Dust particles immersed in plasma collect ions and electrons from the plasma and charge up electrically. Therefore, the presence of dust changes plasma, while at the same time many forces start acting on the dust. Therefore, the dust and plasma become coupled, making dusty plasma a very complex medium to describe, in which many length and time scales play a role, from the Debye length to the length of the electrodes, and from the inverse plasma frequencies to the dust transport times. Using a self-consistent fluid model, we simulate these multi-scale dusty plasmas in radio frequency discharges under micro-gravity. We show that moderate non-linear scattering of ions by the dust particles is the most important aspect in the calculation of the ion drag force. This force is also responsible for the formation of a dust-free 'void' in dusty plasma under micro-gravity, caused by ions moving from the centre of

  17. [The necessity of complex use of radiation and endoscopic techniques in the differential diagnosis of gastric ulcerations].

    PubMed

    Gorshkov, A N; Meshkov, V M; Gracheva, N I; Biakhov, M Iu; Timchenko, I V; Meshkov, M V

    2002-01-01

    The results of examination of 156 patients were used to consider whether radiation and endoscopic techniques might be used in the differential diagnosis of gastric ulcerations. The necessity of their complex use is shown. Evidence is provided for that the understanding of intramural changes at the site of ulceration should underlie the interpretation of visual changes in the gastric mucosa. An algorithm has been developed for the rational and effective use of radiation and endoscopic techniques in the differential diagnosis of gastric ulcerations. The algorithm is shown to be highly effective in the correct interpretation of the pattern of an identified ulceration (98.4% specificity). Ultrasound and computed tomographic semiotics of benign and malignant gastric ulcerations is presented.

  18. Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Wei; Steele, T. G.; Hanif, T.; Mann, R. B.

    2016-08-01

    We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model's couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ ≈ 0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F , which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

  19. A comparative study of methods for computing the diffuse radiation viewfactors for complex structures

    NASA Technical Reports Server (NTRS)

    Emery, A. F.; Johansson, O.; Lobo, M.; Abrous, A.

    1988-01-01

    Several different numerical methods for calculating diffuse radiation viewfactors are described. Each is applied to a range of surface configurations, from almost completely unobstructed to a dense set of intersecting surfaces. The speed, accuracy and unique characteristics are discussed in order to define optimal methods for different surface geometries.

  20. The seismic spectrum, radiated energy, and the Savage and Wood inequality for complex earthquakes

    NASA Astrophysics Data System (ADS)

    Smith, Kenneth D.; Brune, James N.; Priestley, Keith F.

    1991-03-01

    We have integrated velocity squared spectra in order to determine the seismic energy radiated during fault rupture. The high frequency spectral fall-off and the shape of the spectrum at the corner frequency are critical to the energy calculation. High frequency spectral fall-offs of ω-2 beyond the corner frequency, in a Brune (1970) source model, return radiated energies approximately equal to that of an Orowan (1960) type fault failure, where the final stress level is equal to the dynamic frictional stress. Any spectra with an extended intermediate slope of ω-1 would therefore result in higher radiated energies. Savage and Wood (1971) proposed a model in which the final stress level was less than the dynamic stress level and that this was the result of "overshoot". They based their model on the observation that the ratio of twice the apparent stress to the stress drop was typically around 0.3. We show that for such a ratio to exist high frequency spectral fall-offs of ≈ ω-3 would be required. Composite spectra have been constructed for several moderate to large earthquakes, these spectra have been compared to that predicted by the Haskell (1966) model and velocity squared spectra have been integrated to determine the radiated energy. In all cases this ratio, twice the apparent stress to the stress drop, is greater than or equal to one, violating the Savage and Wood (1971) inequality, and provides evidence against "overshoot" as a source model.

  1. Neurobehavioral radiation mitigation to standard brain cancer therapy regimens by Mn(III) n-butoxyethylpyridylporphyrin-based redox modifier.

    PubMed

    Weitzel, Douglas H; Tovmasyan, Artak; Ashcraft, Kathleen A; Boico, Alina; Birer, Samuel R; Roy Choudhury, Kingshuk; Herndon, James; Rodriguiz, Ramona M; Wetsel, William C; Peters, Katherine B; Spasojevic, Ivan; Batinic-Haberle, Ines; Dewhirst, Mark W

    2016-06-01

    Combinations of radiotherapy (RT) and chemotherapy have shown efficacy toward brain tumors. However, therapy-induced oxidative stress can damage normal brain tissue, resulting in both progressive neurocognitive loss and diminished quality of life. We have recently shown that MnTnBuOE-2-PyP(5+) (Mn(III)meso-tetrakis(N-n-butoxyethylpyridinium -2-yl)porphyrin) rescued RT-induced white matter damage in cranially-irradiated mice. Radiotherapy is not used in isolation for treatment of brain tumors; temozolomide is the standard-of-care for adult glioblastoma, whereas cisplatin is often used for treatment of pediatric brain tumors. Therefore, we evaluated the brain radiation mitigation ability of MnTnBuOE-2-PyP(5+) after either temozolomide or cisplatin was used singly or in combination with 10 Gy RT. MnTnBuOE-2-PyP(5+) accumulated in brains at low nanomolar levels. Histological and neurobehavioral testing showed a drastic decrease (1) of axon density in the corpus callosum and (2) rotorod and running wheel performance in the RT only treatment group, respectively. MnTnBuOE-2-PyP(5+) completely rescued this phenotype in irradiated animals. In the temozolomide groups, temozolomide/ RT treatment resulted in further decreased rotorod responses over RT alone. Again, MnTnBuOE-2-PyP(5+) treatment rescued the negative effects of both temozolomide ± RT on rotorod performance. While the cisplatin-treated groups did not give similar results as the temozolomide groups, inclusion of MnTnBuOE-2-PyP(5+) did not negatively affect rotorod performance. Additionally, MnTnBuOE-2-PyP(5+) sensitized glioblastomas to either RT ± temozolomide in flank tumor models. Mice treated with both MnTnBuOE-2-PyP(5+) and radio-/chemo-therapy herein demonstrated brain radiation mitigation. MnTnBuOE-2-PyP(5+) may well serve as a normal tissue radio-/chemo-mitigator adjuvant therapy to standard brain cancer treatment regimens. Environ. Mol. Mutagen. 57:372-381, 2016. © 2016 Wiley Periodicals, Inc.

  2. Radiation and scattering by thin-wire structures in the complex frequency domain. [electromagnetic theory for thin-wire antennas

    NASA Technical Reports Server (NTRS)

    Richmond, J. H.

    1974-01-01

    Piecewise-sinusoidal expansion functions and Galerkin's method are employed to formulate a solution for an arbitrary thin-wire configuration in a homogeneous conducting medium. The analysis is performed in the real or complex frequency domain. In antenna problems, the solution determines the current distribution, impedance, radiation efficiency, gain and far-field patterns. In scattering problems, the solution determines the absorption cross section, scattering cross section and the polarization scattering matrix. The electromagnetic theory is presented for thin wires and the forward-scattering theorem is developed for an arbitrary target in a homogeneous conducting medium.

  3. Evaluation of the WIPP Project`s compliance with the EPA radiation protection standards for disposal of transuranic waste

    SciTech Connect

    Neill, R.H.; Chaturvedi, L.; Rucker, D.F.; Silva, M.K.; Walker, B.A.; Channell, J.K.; Clemo, T.M. |

    1998-03-01

    The US Environmental Protection Agency`s (EPA) proposed rule to certify that the Waste Isolation Pilot Plant (WIPP) meets compliance with the long-term radiation protection standards for geologic repositories (40CFR191 Subparts B and C), is one of the most significant milestones to date for the WIPP project in particular, and for the nuclear waste issue in general. The Environmental Evaluation Group (EEG) has provided an independent technical oversight for the WIPP project since 1978, and is responsible for many improvements in the location, design, and testing of various aspects of the project, including participation in the development of the EPA standards since the early 1980s. The EEG reviewed the development of documentation for assessing the WIPP`s compliance by the Sandia National Laboratories following the 1985 promulgation by EPA, and provided many written and verbal comments on various aspects of this effort, culminating in the overall review of the 1992 performance assessment. For the US Department of Energy`s (DOE) compliance certification application (CCA), the EEG provided detailed comments on the draft CCA in March, 1996, and additional comments through unpublished letters in 1997 (included as Appendices 8.1 and 8.2 in this report). Since the October 30, 1997, publication of the EPA`s proposed rule to certify WIPP, the EEG gave presentations on important issues to the EPA on December 10, 1997, and sent a December 31, 1997 letter with attachments to clarify those issues (Appendix 8.3). The EEG has raised a number of questions that may have an impact on compliance. In spite of the best efforts by the EEG, the EPA reaction to reviews and suggestions has been slow and apparently driven by legal considerations. This report discusses in detail the questions that have been raised about containment requirements. Also discussed are assurance requirements, groundwater protection, individual protection, and an evaluation of EPA`s responses to EEG`s comments.

  4. [Complex pathogenetic treatment schemes of vascular dyscirculatory disorders in the remote period after exposure to low dose radiation].

    PubMed

    Holodova, N B; Zhavoronkova, L A; Ryzhov, B N

    2013-01-01

    Complex studies including modern methods of investigation of structures and functions of nervous system: electroencephalograsphy (EEG), coherent analysis, neuropsychological study and methods of neuroimaging were performed in 517 participants in liquidation of consequences of the accident (LCA) at the Chernobyl NPP in 1986-1987. Dyscirculatory metabolic encephalopathy was revealed to be the main pathology with the etiological mechanism based on dyscirculatorhypoxic and metabolic disorders. Complexity of the revealed symptoms testified to an early organism aging in remote periods after exposure to low dose radiation. Pathogenetic schemes were developed for treatment of dyscirculatory encephalopathy in liquidators, which include drugs improving blood supply, antiaggregants, antioxidants and metabolites of the brains in various combinations. Taking into consideration that early appearance of vascular dyscirculatory disorders observed in liquidators is the sign of early aging of the organism, geroprotectors were added to treatment schemes.

  5. Radiation effects and annealing kinetics in crystalline silicates, phosphates and complex Nb-Ta-Ti oxides. FInal Report

    SciTech Connect

    Ewing, R.C.

    1987-08-10

    Interaction of heavy particles (alpha-recoil nuclei, fission fragments, implanted ions) with ceramics is complex because they have a wide range of structure types, complex compositions and chemical bonding is variable. Radiation damage can produce diverse results, but most commonly, crystalline periodic materials become either polycrystalline or aperiodic (metamict state). We studied the transition from crystalline to aperiodic state in natural materials that have been damaged by alpha recoil nuclei in the U and Th decay series and in synthetic, analogous structure types which have been amorphized by ion implantation. Transition from crystalline to aperiodic was followed by analysis of XRD, high resolution TEM, and EXAFS/XANE spectroscopy. Use of these techniques with increasing dose provided data on an increasing finer scale as the damage process progressed.

  6. Radiative heat transfer in two-dimensional complex enclosures using the modified discrete ordinates method

    SciTech Connect

    Sakami, M.; Charette, A.

    1999-07-01

    Radiative transfer is the dominant mode of heat transfer in many applications. Examples of such applications include combustion chambers, space, greenhouses, rocket plume sensing, to name only a few. However, due to the difficulty in finding an exact analytical solution to the integro-differential radiative transfer equation (RTE) in general absorbing-emitting-scattering media, a diversity of numerical methods have been worked out over the last forty years. In this work, an extension of a modified discrete ordinates method recently proposed by other researchers is presented. It is intended to counter the ray effect inherent in this method. The media analyzed are absorbing, emitting and isotropically or anisotropically scattering and the enclosure geometry is arbitrary. Cases where obstructions are present are also treated. The radiative intensity is broken into two parts: the wall-related intensity and the medium-related intensity. The former is treated separately by rigorous integration over the entire solid boundary. The new differencing scheme recently developed by the authors and based on triangular grids is used for the treatment of the medium-related intensity. Results confirm that the proposed method is a good general remedy for anomalies caused by the ray effect due to the geometry.

  7. Quality of Survival and Growth in Children and Young Adults in the PNET4 European Controlled Trial of Hyperfractionated Versus Conventional Radiation Therapy for Standard-Risk Medulloblastoma

    SciTech Connect

    Kennedy, Colin; Bull, Kim; Chevignard, Mathilde; Culliford, David; Dörr, Helmuth G.; Doz, François; Kortmann, Rolf-Dieter; Lannering, Birgitta; Massimino, Maura; Navajas Gutiérrez, Aurora; Rutkowski, Stefan; Spoudeas, Helen A.; Calaminus, Gabriele

    2014-02-01

    Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life.

  8. Conservation laws, radiative decay rates, and excited state localization in organometallic complexes with strong spin-orbit coupling.

    PubMed

    Powell, B J

    2015-01-01

    There is longstanding fundamental interest in 6-fold coordinated d(6) (t(2g)(6)) transition metal complexes such as [Ru(bpy)3](2+) and Ir(ppy)3, particularly their phosphorescence. This interest has increased with the growing realisation that many of these complexes have potential uses in applications including photovoltaics, imaging, sensing, and light-emitting diodes. In order to design new complexes with properties tailored for specific applications a detailed understanding of the low-energy excited states, particularly the lowest energy triplet state, T1, is required. Here we describe a model of pseudo-octahedral complexes based on a pseudo-angular momentum representation and show that the predictions of this model are in excellent agreement with experiment - even when the deviations from octahedral symmetry are large. This model gives a natural explanation of zero-field splitting of T1 and of the relative radiative rates of the three sublevels in terms of the conservation of time-reversal parity and total angular momentum modulo two. We show that the broad parameter regime consistent with the experimental data implies significant localization of the excited state. PMID:26123864

  9. Conservation laws, radiative decay rates, and excited state localization in organometallic complexes with strong spin-orbit coupling.

    PubMed

    Powell, B J

    2015-06-30

    There is longstanding fundamental interest in 6-fold coordinated d(6) (t(2g)(6)) transition metal complexes such as [Ru(bpy)3](2+) and Ir(ppy)3, particularly their phosphorescence. This interest has increased with the growing realisation that many of these complexes have potential uses in applications including photovoltaics, imaging, sensing, and light-emitting diodes. In order to design new complexes with properties tailored for specific applications a detailed understanding of the low-energy excited states, particularly the lowest energy triplet state, T1, is required. Here we describe a model of pseudo-octahedral complexes based on a pseudo-angular momentum representation and show that the predictions of this model are in excellent agreement with experiment - even when the deviations from octahedral symmetry are large. This model gives a natural explanation of zero-field splitting of T1 and of the relative radiative rates of the three sublevels in terms of the conservation of time-reversal parity and total angular momentum modulo two. We show that the broad parameter regime consistent with the experimental data implies significant localization of the excited state.

  10. On Influence of Neutrals on Dust Particle Charging in Complex Plasmas in the Presence of Electromagnetic Radiation

    SciTech Connect

    Kopnin, S. I.; Morzhakova, A. A.; Popel, S. I.; Shukla, P. K.

    2011-11-29

    Effects associated with neutral component of complex (dusty) ionospheric plasmas which affect dust particle charging are studied. Microscopic ion currents on dust particles with taking into account ion-neutral interaction are presented. Calculations are performed both for the case of negative charges of dust particles, when the influence of Solar radiation on dust particle charging processes is negligible, and for the case of positive charges which is realized in the presence of sufficiently intensive UV or X-ray radiation. We also carry out investigation of the electron heating due to the photoelectric effect. We show that the efficiency of electron heating depends on the density of neutral component of the plasma. As result, we determine altitudes where the influence of the neutral plasma component on dust particle charging processes as well as the electron heating effect are significant and should be taken into account under consideration of the ionospheric complex plasmas. In particular, we show that the effects considered could be important for the description of noctilucent clouds, polar mesosphere summer echoes, and some other physical phenomena associated with dust particles in the ionosphere.

  11. Context dependence in complex adaptive landscapes: frequency and trait-dependent selection surfaces within an adaptive radiation of Caribbean pupfishes.

    PubMed

    Martin, Christopher H

    2016-06-01

    The adaptive landscape provides the foundational bridge between micro- and macroevolution. One well-known caveat to this perspective is that fitness surfaces depend on ecological context, including competitor frequency, traits measured, and resource abundance. However, this view is based largely on intraspecific studies. It is still unknown how context-dependence affects the larger features of peaks and valleys on the landscape which ultimately drive speciation and adaptive radiation. Here, I explore this question using one of the most complex fitness landscapes measured in the wild in a sympatric pupfish radiation endemic to San Salvador Island, Bahamas by tracking survival and growth of laboratory-reared F2 hybrids. I present new analyses of the effects of competitor frequency, dietary isotopes, and trait subsets on this fitness landscape. Contrary to expectations, decreasing competitor frequency increased survival only among very common phenotypes, whereas less common phenotypes rarely survived despite few competitors, suggesting that performance, not competitor frequency, shapes large-scale features of the fitness landscape. Dietary isotopes were weakly correlated with phenotype and growth, but did not explain additional survival variation. Nonlinear fitness surfaces varied substantially among trait subsets, revealing one-, two-, and three-peak landscapes, demonstrating the complexity of selection in the wild, even among similar functional traits. PMID:27130447

  12. Aligning "TextEvaluator"® Scores with the Accelerated Text Complexity Guidelines Specified in the Common Core State Standards. Research Report. ETS RR-15-21

    ERIC Educational Resources Information Center

    Sheehan, Kathleen M.

    2015-01-01

    The "TextEvaluator"® text analysis tool is a fully automated text complexity evaluation tool designed to help teachers, curriculum specialists, textbook publishers, and test developers select texts that are consistent with the text complexity guidelines specified in the Common Core State Standards.This paper documents the procedure used…

  13. The Standard European Vector Architecture (SEVA): a coherent platform for the analysis and deployment of complex prokaryotic phenotypes.

    PubMed

    Silva-Rocha, Rafael; Martínez-García, Esteban; Calles, Belén; Chavarría, Max; Arce-Rodríguez, Alejandro; de Las Heras, Aitor; Páez-Espino, A David; Durante-Rodríguez, Gonzalo; Kim, Juhyun; Nikel, Pablo I; Platero, Raúl; de Lorenzo, Víctor

    2013-01-01

    The 'Standard European Vector Architecture' database (SEVA-DB, http://seva.cnb.csic.es) was conceived as a user-friendly, web-based resource and a material clone repository to assist in the choice of optimal plasmid vectors for de-constructing and re-constructing complex prokaryotic phenotypes. The SEVA-DB adopts simple design concepts that facilitate the swapping of functional modules and the extension of genome engineering options to microorganisms beyond typical laboratory strains. Under the SEVA standard, every DNA portion of the plasmid vectors is minimized, edited for flaws in their sequence and/or functionality, and endowed with physical connectivity through three inter-segment insulators that are flanked by fixed, rare restriction sites. Such a scaffold enables the exchangeability of multiple origins of replication and diverse antibiotic selection markers to shape a frame for their further combination with a large variety of cargo modules that can be used for varied end-applications. The core collection of constructs that are available at the SEVA-DB has been produced as a starting point for the further expansion of the formatted vector platform. We argue that adoption of the SEVA format can become a shortcut to fill the phenomenal gap between the existing power of DNA synthesis and the actual engineering of predictable and efficacious bacteria.

  14. Quantification of Complex Polycyclic Aromatic Hydrocarbon Mixtures in Standard Reference Materials Using GC×GC/ToF-MS

    PubMed Central

    Manzano, Carlos; Hoh, Eunha; Massey Simonich, Staci L.

    2014-01-01

    This research is the first to quantify complex PAH mixtures in NIST SRMs using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/ToF-MS), with and without extract cleanup, and reports previously unidentified PAH isomers in the NIST SRMs. We tested a novel, high orthogonality GC column combination (LC-50×NSP-35), as well as with a commonly used column combination (Rtx-5ms×Rxi-17) for the quantification of a complex mixture of 85 different PAHs, including parent (PAHs), alkyl- (MPAHs), nitro- (NPAHs), oxy- (OPAHs), thio- (SPAHs), bromo- (BrPAHs), and chloro-PAHs (ClPAHs) in extracts from two standard reference materials: NIST SRM1650b (diesel particulate matter), with cleanup and NIST SRM1975 (diesel particulate extract), with and without extract cleanup. The LC-50×NSP-35 column combination resulted in an average absolute percent difference of 33.8%, 62.2% and 30.8% compared to the NIST certified PAH concentrations for NIST SRM1650b, NIST SRM1975 with cleanup and NIST SRM1975 without cleanup, while the Rtx-5ms×Rxi-17 resulted in an absolute percent difference of 38.6%, 67.2% and 79.6% for NIST SRM1650b, NIST SRM1975 with cleanup and NIST SRM1975 without cleanup, respectively. This GC×GC/ToF-MS method increases the number of PAHs detected and quantified in complex environmental extracts using a single chromatographic run. Without clean-up, 7 additional compounds were detected and quantified in NIST SRM1975 using the LC-50×NSP-35 column combination. These results suggest that the use of the LC-50×NSP-35 column combination in GC×GC/ToF-MS not only results in better chromatographic resolution and greater orthogonality for the separation of complex PAH mixtures, but can also be used for the accurate quantification of complex PAH mixtures in environmental extracts without cleanup. PMID:23932031

  15. Disentangling regular and chaotic motion in the standard map using complex network analysis of recurrences in phase space.

    PubMed

    Zou, Yong; Donner, Reik V; Thiel, Marco; Kurths, Jürgen

    2016-02-01

    Recurrence in the phase space of complex systems is a well-studied phenomenon, which has provided deep insights into the nonlinear dynamics of such systems. For dissipative systems, characteristics based on recurrence plots have recently attracted much interest for discriminating qualitatively different types of dynamics in terms of measures of complexity, dynamical invariants, or even structural characteristics of the underlying attractor's geometry in phase space. Here, we demonstrate that the latter approach also provides a corresponding distinction between different co-existing dynamical regimes of the standard map, a paradigmatic example of a low-dimensional conservative system. Specifically, we show that the recently developed approach of recurrence network analysis provides potentially useful geometric characteristics distinguishing between regular and chaotic orbits. We find that chaotic orbits in an intermittent laminar phase (commonly referred to as sticky orbits) have a distinct geometric structure possibly differing in a subtle way from those of regular orbits, which is highlighted by different recurrence network properties obtained from relatively short time series. Thus, this approach can help discriminating regular orbits from laminar phases of chaotic ones, which presents a persistent challenge to many existing chaos detection techniques. PMID:26931601

  16. Disentangling regular and chaotic motion in the standard map using complex network analysis of recurrences in phase space.

    PubMed

    Zou, Yong; Donner, Reik V; Thiel, Marco; Kurths, Jürgen

    2016-02-01

    Recurrence in the phase space of complex systems is a well-studied phenomenon, which has provided deep insights into the nonlinear dynamics of such systems. For dissipative systems, characteristics based on recurrence plots have recently attracted much interest for discriminating qualitatively different types of dynamics in terms of measures of complexity, dynamical invariants, or even structural characteristics of the underlying attractor's geometry in phase space. Here, we demonstrate that the latter approach also provides a corresponding distinction between different co-existing dynamical regimes of the standard map, a paradigmatic example of a low-dimensional conservative system. Specifically, we show that the recently developed approach of recurrence network analysis provides potentially useful geometric characteristics distinguishing between regular and chaotic orbits. We find that chaotic orbits in an intermittent laminar phase (commonly referred to as sticky orbits) have a distinct geometric structure possibly differing in a subtle way from those of regular orbits, which is highlighted by different recurrence network properties obtained from relatively short time series. Thus, this approach can help discriminating regular orbits from laminar phases of chaotic ones, which presents a persistent challenge to many existing chaos detection techniques.

  17. The analysis of complex mixed-radiation fields using near real-time imaging.

    PubMed

    Beaumont, Jonathan; Mellor, Matthew P; Joyce, Malcolm J

    2014-10-01

    A new mixed-field imaging system has been constructed at Lancaster University using the principles of collimation and back projection to passively locate and assess sources of neutron and gamma-ray radiation. The system was set up at the University of Manchester where three radiation sources: (252)Cf, a lead-shielded (241)Am/Be and a (22)Na source were imaged. Real-time discrimination was used to find the respective components of the neutron and gamma-ray fields detected by a single EJ-301 liquid scintillator, allowing separate images of neutron and gamma-ray emitters to be formed. (252)Cf and (22)Na were successfully observed and located in the gamma-ray image; however, the (241)Am/Be was not seen owing to surrounding lead shielding. The (252)Cf and (241)Am/Be neutron sources were seen clearly in the neutron image, demonstrating the advantage of this mixed-field technique over a gamma-ray-only image where the (241)Am/Be source would have gone undetected.

  18. [Corrective effects of electromagnetic radiation in a millimeter wavelength range on the parameters of oxidative stress after standard anti-helicobacterial therapy in patients with ulcer disease].

    PubMed

    Ivanishkina, E V; Podoprigorova, V G

    2012-01-01

    We assessed the possibilities of correction of oxidative stress parameters in the serum and gastroduodenal mucosa using electromagnetic radiation in a millimeter wavelength range in 127 patients with gastric and duodenal ulcer after eradication therapy. Control group included 230 healthy subjects. Parameter of lipid oxidation by free radicals were measured by direct methods (hemiluminescence and EPR-spectroscopy). The results show that standard eradication therapy does not influence parameters of oxidative stress. More pronounced effect of electromagnetic radiation in a millimeter wavelength range may be due to the correction of prooxidant-antioxidant and antioxidant disbalance. This observation provides pathogenetic substantiation for the inclusion of this physical method in modern therapeutic modalities.

  19. Chemical Partition of the Radiative Decay Rate of Luminescence of Europium Complexes

    PubMed Central

    Lima, Nathalia B. D.; Dutra, José Diogo L.; Gonçalves, Simone M. C.; Freire, Ricardo O.; Simas, Alfredo M.

    2016-01-01

    The spontaneous emission coefficient, Arad, a global molecular property, is one of the most important quantities related to the luminescence of complexes of lanthanide ions. In this work, by suitable algebraic transformations of the matrices involved, we introduce a partition that allows us to compute, for the first time, the individual effects of each ligand on Arad, a property of the molecule as a whole. Such a chemical partition thus opens possibilities for the comprehension of the role of each of the ligands and their interactions on the luminescence of europium coordination compounds. As an example, we applied the chemical partition to the case of repeating non-ionic ligand ternary complexes of europium(III) with DBM, TTA, and BTFA, showing that it allowed us to correctly order, in an a priori manner, the non-obvious pair combinations of non-ionic ligands that led to mixed-ligand compounds with larger values of Arad. PMID:26892900

  20. Chemical Partition of the Radiative Decay Rate of Luminescence of Europium Complexes

    NASA Astrophysics Data System (ADS)

    Lima, Nathalia B. D.; Dutra, José Diogo L.; Gonçalves, Simone M. C.; Freire, Ricardo O.; Simas, Alfredo M.

    2016-02-01

    The spontaneous emission coefficient, Arad, a global molecular property, is one of the most important quantities related to the luminescence of complexes of lanthanide ions. In this work, by suitable algebraic transformations of the matrices involved, we introduce a partition that allows us to compute, for the first time, the individual effects of each ligand on Arad, a property of the molecule as a whole. Such a chemical partition thus opens possibilities for the comprehension of the role of each of the ligands and their interactions on the luminescence of europium coordination compounds. As an example, we applied the chemical partition to the case of repeating non-ionic ligand ternary complexes of europium(III) with DBM, TTA, and BTFA, showing that it allowed us to correctly order, in an a priori manner, the non-obvious pair combinations of non-ionic ligands that led to mixed-ligand compounds with larger values of Arad.

  1. Radiation and diversification within the Ligularia-Cremanthodium-Parasenecio complex (Asteraceae) triggered by uplift of the Qinghai-Tibetan Plateau.

    PubMed

    Liu, Jian-Quan; Wang, Yu-Jing; Wang, Ai-Lan; Hideaki, Ohba; Abbott, Richard J

    2006-01-01

    The Ligularia-Cremanthodium-Parasenecio (L-C-P) complex of the Tussilagininae (Asteraceae: Senecioneae) contains more than 200 species that are endemic to the Qinghai-Tibetan Plateau in eastern Asia. These species are morphologically distinct; however, their relationships appear complex. A phylogenetic analysis of members of the complex and selected taxa of the tribe Senecioneae was conducted using chloroplast (ndhF and trnL-F) and nuclear (ITS) sequences. Phylogenetic trees were constructed from individual and combined datasets of the three different sequences. All analyses suggested that Doronicum, a genus that has been included in the Tussilagininae, should be excluded from this subtribe and placed at the base of the tribe Senecioneae. In addition, the Tussilagininae should be broadly circumscribed to include the Tephroseridinae. Within the expanded Tussilagininae containing all 13 genera occurring in eastern Asia, Tussilago and Petasites diverged early as a separate lineage, while the remaining 11 genera comprise an expanded L-C-P complex clade. We suggest that the L-C-P clade, which is largely unresolved, most likely originated as a consequence of an explosive radiation. The few monophyletic subclades identified in the L-C-P clade with robust support further suggest that some genera of Tussilagininae from eastern Asia require generic re-circumscriptions given the occurrence of subclades containing species of the same genus in different parts of the phylogentic tree due to homoplasy of important morphological characters used to delimit them. Molecular-clock analyses suggest that the explosive radiation of the L-C-P complex occurred mostly within the last 20 million years, which falls well within the period of recent major uplifts of the Qinghai-Tibetan Plateau between the early Miocene to the Pleistocene. It is proposed that significant increases in geological and ecological diversity that accompanied such uplifting, most likely promoted rapid and continuous

  2. Preparation and Evaluation of Phospholipid-Based Complex of Standardized Centella Extract (SCE) for the Enhanced Delivery of Phytoconstituents.

    PubMed

    Saoji, Suprit D; Raut, Nishikant A; Dhore, Pradip W; Borkar, Chandrashekhar D; Popielarczyk, Michael; Dave, Vivek S

    2016-01-01

    In the present study, a phospholipid-based complex of standardized Centella extract (SCE) was developed with a goal of improving the bioavailability of its phytoconstituents. The SCE-phospholipid complex was prepared by solvent evaporation method and characterized for its physicochemical and functional properties. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), photomicroscopy, and powder x-ray diffraction (PXRD) were used to confirm the formation of Centella naturosome (CN). The prepared complex was functionally evaluated by apparent solubility, in vitro drug release, ex vivo permeation, and in vivo efficacy studies. The prepared CN exhibited a significantly higher (12-fold) aqueous solubility (98.0 ± 1.4 μg/mL), compared to the pure SCE (8.12 ± 0.44 μg/mL), or the physical mixture of SCE and the phospholipid (13.6 ± 0.4 μg/mL). The in vitro dissolution studies revealed a significantly higher efficiency of CN in releasing the SCE (99.2 ± 4.7, % w/w) in comparison to the pure SCE (39.2 ± 2.3, % w/w), or the physical mixture (42.8 ± 2.09, % w/w). The ex vivo permeation studies with the everted intestine method showed that the prepared CN significantly improved the permeation of SCE (82.8 ± 3.7, % w/w), compared to the pure SCE (26.8 ± 2.4, % w/w), or the physical mixture (33.0 ± 2.7, % w/w). The in vivo efficacy studies using the Morris Water Maze test indicated a significant improvement of the spatial learning and memory in aged mice treated with CN. Thus, drug-phospholipid complexation appears to be a promising strategy to improve the aqueous solubility and bioavailability of bioactive phytoconstituents.

  3. The SIBERIA dedicated synchrotron radiation source: status report on the storage rings complex at the Kurchatov Institute for Atomic Energy

    NASA Astrophysics Data System (ADS)

    Artemiev, A. N.; Akhmedzhanov, S. M.; Vasilyev, A. A.; Gritsuk, G. M.; Dozorov, A. V.; Doronkin, Yu. V.; Zabelin, A. V.; Klimenko, M. N.; Kotov, S. A.; Krylov, Yu. V.; Lebedev, V. A.; Lipilin, A. V.; Nagornyh, I. M.; Nikulin, O. N.; Odintsov, D. G.; Pashkov, S. D.; Pesterev, S. G.; Prosvetov, V. K.; Rybakov, V. N.; Samorukov, M. M.; Treshchin, V. A.; Ushkov, V. L.; Tsup, A. R.; Chaikin, E. M.; Yupinov, Yu. L.

    1991-10-01

    This paper reviews the status of the SIBERIA storage rings complex. The parameters of the linac, booster synchrotron and main ring are given. The transfer of the SIBERIA-1 storage ring to its new site is described. The main parameters of the engineering systems for the SIBERIA complex are presented. The assembly of the SIBERIA-2 storage ring is planned to be finished in 1991. The SIBERIA storage rings complex has been constructed at the Kurchatov Institute for Atomic Energy (IAE) and is the first dedicated synchrotron radiation source in the USSR. The facility includes the SIBERIA-1 450 MeV electron storage ring, the SIBERIA-2 2.5 GeV electron storage ring, two electron transport lines EOC-1 and EOC-2, and an 80-100 MeV electron linac which serves as the injector. The general layout of SIBERIA is shown in fig. 1. All accelerators of the SIBERIA facility are designed and manufactured at the Institute of Nuclear Physics (INP) at Novosibirsk.

  4. Water binding energies of [Pb(amino acid-H)H2O]+ complexes determined by blackbody infrared radiative dissociation.

    PubMed

    Burt, Michael B; Decker, Sarah G A; Fridgen, Travis D

    2012-11-21

    The water binding energies (E(0)) of eight deprotonated Pb(2+)-amino acid (Aa) complexes of the form [Pb(Aa-H)H(2)O](+) (Aa = Gly, Ala, Val, Leu, Ile, Phe, Glu, and Lys) were determined using blackbody infrared radiative dissociation (BIRD). A Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer was used to trap ions generated by electrospray ionization (ESI) in a "zero"-pressure (~10(-10) torr) cell where dissociation can only occur by absorption of thermally generated photons. Since the [Pb(Aa-H)H(2)O](+) complexes have relatively few vibrational degrees of freedom (36-78) and are within the slow-exchange kinetic limit, the master equation was solved to extract meaningful threshold dissociation energies and thermal unimolecular dissociation rate constants (k(uni)). The master equation analysis uses variable reaction coordinate transition state theory (VRC-TST) to minimize the Rice-Ramsperger-Kassel-Marcus (RRKM) dissociation rate constants. The determined water binding energies range from 76.6 to 113.6 kJ mol(-1), and agree well with 0 K dissociation energies calculated using the B3LYP/6-31+G(d,p) and MP2(full)/6-311++G(2d,2p)//B3LYP/6-31+G(d,p) methods. The relative strengths of the binding energies reflect the known structural isomers (A-, B-, C-, and D-type) of these [Pb(Aa-H)H(2)O](+) complexes.

  5. Probing Ionic Complexes of Ethylene and Acetylene with Vacuum-Ultraviolet Radiation.

    PubMed

    Bandyopadhyay, Biswajit; Stein, Tamar; Fang, Yigang; Kostko, Oleg; White, Alec; Head-Gordon, Martin; Ahmed, Musahid

    2016-07-14

    Mixed complexes of acetylene-ethylene are studied using vacuum-ultraviolet (VUV) photoionization mass spectrometry and theoretical calculations. These complexes are produced and ionized at different distances from the exit of a continuous nozzle followed by reflectron time-of-flight mass spectrometry detection. Acetylene, with a higher ionization energy (11.4 eV) than ethylene (10.6 eV), allows for tuning the VUV energy and initializing reactions either from a C2H2(+) or a C2H4(+) cation. Pure acetylene and ethylene expansions are separately carried out to compare, contrast, and hence identify products from the mixed expansion: these are C3H3(+) (m/z = 39), C4H5(+) (m/z = 53), and C5H5(+) (m/z = 65). Intensity distributions of C2H2, C2H4, their dimers and reactions products are plotted as a function of ionization distance. These distributions suggest that association mechanisms play a crucial role in product formation closer to the nozzle. Photoionization efficiency (PIE) curves of the mixed complexes demonstrate rising edges closer to both ethylene and acetylene ionization energies. We use density functional theory (ωB97X-V/aug-cc-pVTZ) to study the structures of the neutral and ionized dimers, calculate their adiabatic and vertical ionization energies, as well as the energetics of different isomers on the potential energy surface (PES). Upon ionization, vibrationally excited clusters can use the extra energy to access different isomers on the PES. At farther ionization distances from the nozzle, where the number densities are lower, unimolecular decay is expected to be the dominant mechanism. We discuss the possible decay pathways from the different isomers on the PES and examine the ones that are energetically accessible. PMID:26983013

  6. Hawking radiation for twisted complex scalar fields on the Reissner-Nordström black holes and Dirac monopoles

    NASA Astrophysics Data System (ADS)

    Goncharov, Yu. P.; Firsova, N. E.

    1997-02-01

    We study, both analytically and numerically, the contribution of the twisted topologically inequivalent configurations (TICs) of complex scalar fields on the Reissner-Nordström black holes to the Hawking radiation. Physically this contribution is conditioned by the natural presence of the Dirac monopoles on the black holes. When neglecting the own (external) electric field of black hole it is established that while increasing the black hole electric charge Q to the extremal value Q = M (M is the black hole mass), the given contribution to the total luminosity (summed up over all the TICs) of the black hole decreases (from the one of order 17% at Q = 0) up to 0. At this value the total luminosity itself tends to 0.

  7. Polysaccharide protein complex isolated from mushroom Phellinus rimosus (berk.) Pilat alleviates γ radiation-induced toxicity in mice.

    PubMed

    Joseph, Jini; Smina, Thozhuthum Parambil Pathmanabhan; Janardhanan, Kainoor Krishnankutty

    2011-06-01

    Ionizing radiations generate reactive oxygen species in irradiated tissue that induces several pathophysiological changes in the body. Radiotherapy induced toxicity is a major dose-limiting factor in anticancer treatments. Radioprotective agents are of significant importance in medical, industrial, environmental, military, and space applications. Radioprotective effect of polysaccharide protein complex (PPC-Pr) isolated from mushroom, Phellinus rimosus, was evaluated in Swiss albino mice. PPC-Pr (5 and 10 mg/kg bwt, i.p.) significantly increased leukocyte count, bone marrow cellularity, glutathione content, and activities of antioxidant enzymes such as catalase, superoxide dismutase, and glutathione peroxidase in blood as well as intestinal mucosa when compared with the irradiated control group. Histopathological observation of intestinal jejunal mucosa revealed the tissue protective effects of PPC-Pr. Further radioprotective activity of PPC-Pr was in a dose-dependent manner. The findings suggest potential radioprotective efficacy of PPC-Pr.

  8. Complex responses of intertidal molluscan embryos to a warming and acidifying ocean in the presence of UV radiation.

    PubMed

    Davis, Andrew R; Coleman, Daniel; Broad, Allison; Byrne, Maria; Dworjanyn, Symon A; Przeslawski, Rachel

    2013-01-01

    Climate change and ocean acidification will expose marine organisms to synchronous multiple stressors, with early life stages being potentially most vulnerable to changing environmental conditions. We simultaneously exposed encapsulated molluscan embryos to three abiotic stressors-acidified conditions, elevated temperate, and solar UV radiation in large outdoor water tables in a multifactorial design. Solar UV radiation was modified with plastic filters, while levels of the other factors reflected IPCC predictions for near-future change. We quantified mortality and the rate of embryonic development for a mid-shore littorinid, Bembicium nanum, and low-shore opisthobranch, Dolabrifera brazieri. Outcomes were consistent for these model species with embryos faring significantly better at 26°C than 22°C. Mortality sharply increased at the lowest temperature (22°C) and lowest pH (7.6) examined, producing a significant interaction. Under these conditions mortality approached 100% for each species, representing a 2- to 4-fold increase in mortality relative to warm (26°C) non-acidified conditions. Predictably, development was more rapid at the highest temperature but this again interacted with acidified conditions. Development was slowed under acidified conditions at the lowest temperature. The presence of UV radiation had minimal impact on the outcomes, only slowing development for the littorinid and not interacting with the other factors. Our findings suggest that a warming ocean, at least to a threshold, may compensate for the effects of decreasing pH for some species. It also appears that stressors will interact in complex and unpredictable ways in a changing climate.

  9. Complex Responses of Intertidal Molluscan Embryos to a Warming and Acidifying Ocean in the Presence of UV Radiation

    PubMed Central

    Davis, Andrew R.; Coleman, Daniel; Broad, Allison; Byrne, Maria; Dworjanyn, Symon A.; Przeslawski, Rachel

    2013-01-01

    Climate change and ocean acidification will expose marine organisms to synchronous multiple stressors, with early life stages being potentially most vulnerable to changing environmental conditions. We simultaneously exposed encapsulated molluscan embryos to three abiotic stressors—acidified conditions, elevated temperate, and solar UV radiation in large outdoor water tables in a multifactorial design. Solar UV radiation was modified with plastic filters, while levels of the other factors reflected IPCC predictions for near-future change. We quantified mortality and the rate of embryonic development for a mid-shore littorinid, Bembicium nanum, and low-shore opisthobranch, Dolabrifera brazieri. Outcomes were consistent for these model species with embryos faring significantly better at 26°C than 22°C. Mortality sharply increased at the lowest temperature (22°C) and lowest pH (7.6) examined, producing a significant interaction. Under these conditions mortality approached 100% for each species, representing a 2- to 4-fold increase in mortality relative to warm (26°C) non-acidified conditions. Predictably, development was more rapid at the highest temperature but this again interacted with acidified conditions. Development was slowed under acidified conditions at the lowest temperature. The presence of UV radiation had minimal impact on the outcomes, only slowing development for the littorinid and not interacting with the other factors. Our findings suggest that a warming ocean, at least to a threshold, may compensate for the effects of decreasing pH for some species. It also appears that stressors will interact in complex and unpredictable ways in a changing climate. PMID:23405238

  10. Particle acceleration and radiation in flaring complex solar active regions modeled by cellular automata

    NASA Astrophysics Data System (ADS)

    Dauphin, C.; Vilmer, N.; Anastasiadis, A.

    2007-06-01

    Context: We study the acceleration and radiation of electrons and ions interacting with multiple small-scale dissipation regions resulting from the magnetic energy release process. Aims: We aim to calculate the distribution functions of the kinetic energy of the particles and the X-ray spectra and γ-ray fluxes produced by the accelerated particles. Methods: The evolution of the magnetic energy released in an active region is mimicked by a cellular automaton model based on the concept of self-organized criticality. Each burst of magnetic energy release is associated with a reconnecting current sheet (RCS) in which the particles are accelerated by a direct electric field. Results: We calculate the energy gain of the particles (ions and electrons) for three different magnetic configurations of the RCS after their interactions with a given number of RCS. We finally compare our results with existing observations. Conclusions: The results of our simulation can reproduce several properties of the observations such as variable electron and ion energy contents and γ-ray line ratio. Even if very flat X-ray spectra have been reported in a few events, the X-ray spectra produced in this model are too flat when compared to most X-ray observations.

  11. Complex composite engineering architectures for nuclear and high-radiation environments

    SciTech Connect

    Kornreich, Drew E; Vaidya, Rajendra U; Ammerman, Curtt N

    2010-01-01

    Integrated Computational Materials Engineering (ICME) is a novel overarching approach to bridge length and time scales in computational materials science and engineering. This approach integrates all elements of multi-scale modeling (including various empirical and science-based models) with materials informatics to provide users the opportunity to tailor material selections based on stringent application needs. Typically, materials engineering has focused on structural requirements (stress, strain, modulus, fracture toughness etc.) while multi-scale modeling has been science focused (mechanical threshold strength model, grain-size models, solid-solution strengthening models etc.). Materials informatics (mechanical property inventories) on the other hand, is extensively data focused. All of these elements are combined within the framework of ICME to create architecture for the development, selection and design new composite materials for challenging environments. We propose development of the foundations for applying ICME to composite materials development for nuclear and high-radiation environments (including nuclear-fusion energy reactors, nuclear-fission reactors, and accelerators). We expect to combine all elements of current material models (including thermo-mechanical and finite-element models) into the ICME framework. This will be accomplished through the use of a various mathematical modeling constructs. These constructs will allow the integration of constituent models, which in tum would allow us to use the adaptive strengths of using a combinatorial scheme (fabrication and computational) for creating new composite materials. A sample problem where these concepts are used is provided in this summary.

  12. EDITORIAL Complexity of advanced radiation therapy necessitates multidisciplinary inquiry into dose reconstruction and risk assessment Complexity of advanced radiation therapy necessitates multidisciplinary inquiry into dose reconstruction and risk assessment

    NASA Astrophysics Data System (ADS)

    Newhauser, Wayne

    2010-07-01

    The availability of low-cost, high-performance computing is rapidly transforming the landscape of cancer research. Computational techniques are playing an increasingly important role and have become the third major method of scientific inquiry, supplementing traditional methods of observation and theory. This evolution began in the 1940s when high-performance computing techniques were developed for military applications, including radiation transport calculations. These same basic methods are still widely utilized in a broad spectrum of computational problems in medicine, including radiation cancer therapy (Rogers 2006, Spezi 2010) and radiologic diagnostic imaging (Doi 2006, Kalender 2006). Supercomputing is also now being used to study the genetics and genomics of cancer (Geurts van Kessel 2010), with application to gene sequencing (Mardis 2008), genome-wide association studies (Pearson and Manolio 2008), biomolecular dynamics (Sanbonmatsu and Tung 2007) and systems biology (Wolkenhauer et al 2010). The extensive and growing body of literature is evidence of a remarkable expansion of activity and enormous boost to cancer research from the application of high-performance computing. Early successes were facilitated by inexpensive computing resources and advances in modeling algorithms. Many contemporary models require extensive approximations and phenomenological approaches. In fact, many critical problems remain computationally intractable; the underlying physical and biological processes are simply too complex to model with contemporary theory and computing capacity. In the future, a vast stream of new insights will flow from studies that use increasingly exact models and first-principles approaches. Hence, in the war on cancer the present status of computational research could be summarized as the beginning of the beginning. For these reasons, there is a vital need for scientists and clinicians to periodically discuss progress and future plans regarding

  13. Modification of the chemical composition and structure of the US Reference Standard Endotoxin (RSE) by /sup 60/Co radiation

    SciTech Connect

    Csako, G.; Tsai, C.M.; Slomiany, B.L.; Herp, A.; Elin, R.J.

    1986-03-01

    A highly purified bacterial lipopolysaccharide (LPS) preparation was exposed in water to megadoses of ionizing radiation from a /sup 60/Co source. As evidenced by electrophoresis, the radiation treatment progressively degraded the lipopolysaccharide molecules by removing first the O-side chain units and then components of the R-core. Chemical analysis of the irradiated (LPS) preparations showed that, in accord with the structural changes, the most profound effects of ionizing radiation occurred in the hydrophilic oligo/polysaccharide moieties (R-core and O-side chain). Progressively higher doses of radiation degraded the simple sugars in decreasing order of galactose, galactosamine, glucosamine, glucose, and heptose. The R-core component 2-keto-3-deoxyoctonate was the most resistant sugar derivative to ionizing radiation. Due to its central position in the LPS aggregates in water, even at comparatively high doses of radiation the hydrophobic lipid A moiety of endotoxin was less affected than the sugar components. Of the fatty acids of lipid A, however, either partial conversion of beta-hydroxymyristic acid into myristic acid or selective loss of the former occurred. The observed structural and chemical changes of LPS are consistent with the effect of active oxygen radicals of radiolysis. In addition, the extensive physicochemical changes explain the altered biological reactivity of radiation-treated endotoxins.

  14. On the standard conjecture and the existence of a Chow-Lefschetz decomposition for complex projective varieties

    NASA Astrophysics Data System (ADS)

    Tankeev, S. G.

    2015-02-01

    We prove the Grothendieck standard conjecture B(X) of Lefschetz type on the algebraicity of the operators * and Λ of Hodge theory for a smooth complex projective variety X if at least one of the following conditions holds: X is a compactification of the Néron minimal model of an Abelian scheme of relative dimension 3 over an affine curve, and the generic scheme fibre of the Abelian scheme has reductions of multiplicative type at all infinite places; X is an irreducible holomorphic symplectic (hyperkähler) 4-dimensional variety that coincides with the Altman-Kleiman compactification of the relative Jacobian variety of a family C\\to P^2 of hyperelliptic curves of genus 2 with weak degenerations, and the canonical projection X\\to P^2 is a Lagrangian fibration. We also show that a Chow-Lefschetz decomposition exists for every smooth projective 3-dimensional variety X which has the structure of a 1-parameter non-isotrivial family of K3-surfaces (with degenerations) or a family of regular surfaces of arbitrary Kodaira dimension \\varkappa with strong degenerations.

  15. Absolute quantification of allergens from complex mixtures: a new sensitive tool for standardization of allergen extracts for specific immunotherapy.

    PubMed

    Seppälä, Ulla; Dauly, Claire; Robinson, Sarah; Hornshaw, Martin; Larsen, Jørgen Nedergaard; Ipsen, Henrik

    2011-04-01

    Products for specific diagnosis and immunotherapy of IgE-mediated allergies are currently based on natural extracts. Quantification of major allergen content is an important aspect of standardization as important allergens particularly impact vaccine potency. The aim of the study was to develop a mass spectrometry (MS) based assay for absolute quantification of Timothy (Phleum pratense) pollen allergens Phl p 1 and Phl p 5 in P. pratense extract. High-resolution and accurate mass (HRAM) MS was selected for its ability to detect peptides with high selectivity and mass accuracy (<3 ppm). Isotope labeled heavy peptides were used for absolute quantification of specific isoallergens of Phl p 1 and Phl p 5 at low femtomole level in P. pratense extract. Robustness and linearity of the method was demonstrated with intra day precision ≤ 5% (n = 3). Phl p 1b was shown to be 5 times less abundant than its variant Phl p 1a and Phl p 5b was shown to be 9 times more abundant than the Phl p 5a. The present study shows that allergen, and/or isoallergen specific, surrogate signature peptides analyzed with HRAM MS is a sensitive and accurate tool for identification and quantification of allergens from complex allergen sources.

  16. Exploiting Radiation Damage to Map Proteins in Nucleoprotein Complexes: The Internal Structure of Bacteriophage T7

    PubMed Central

    Cheng, Naiqian; Wu, Weimin; Watts, Norman R.; Steven, Alasdair C.

    2014-01-01

    In the final stage of radiation damage in cryo-electron microscopy of proteins, bubbles of hydrogen gas are generated. Proteins embedded in DNA bubble sooner than free-standing proteins and DNA does not bubble under the same conditions. These properties make it possible to distinguish protein from DNA. Here we explored the scope of this technique (“bubblegram imaging”) by applying it to bacteriophage T7, viewed as a partially defined model system. T7 has a thin-walled icosahedral capsid, 60 nm in diameter, with a barrel-shaped protein core under one of its twelve vertices (the portal vertex). The core is densely wrapped with DNA but details of their interaction and how their injection into a host bacterium is coordinated are lacking. With short (10 sec) intervals between exposures of 17 electrons/Å2 each, bubbling starts in the third exposure, with 1 – 4 bubbles nucleating in the core: in subsequent exposures, these bubbles grow and merge. A 3D reconstruction from fifth-exposure images depicts a bipartite cylindrical gas cloud in the core. In its portal-proximal half, the axial region is gaseous whereas in the portal-distal half, it is occupied by a 3 nm-wide dense rod. We propose that they respectively represent core protein and an end of the packaged genome, poised for injection into a host cell. Single bubbles at other sites may represent residual scaffolding protein. Thus, bubbling depends on dose rate, protein amount, and tightness of the DNA seal. PMID:24345345

  17. The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities.

    PubMed

    Bilski, P; Blomgren, J; d'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2007-01-01

    The European Commission is funding within its Sixth Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organisational framework for this project is provided by the European Radiation Dosimetry Group EURADOS. One task within the CONRAD project, Work Package 6 (WP6), was to provide a report outlining research needs and research activities within Europe to develop new and improved methods and techniques for the characterisation of complex radiation fields at workplaces around high-energy accelerators, but also at the next generation of thermonuclear fusion facilities. The paper provides an overview of the report, which will be available as CERN Yellow Report.

  18. An empirical method for the determination of the complex refractive index of size-fractionated atmospheric aerosols for radiative transfer calculations.

    SciTech Connect

    Marley, N. A.; Gaffney, J. S.; Baird, J. C.; Drayton, P. J.; Frederick, J. E.; Environmental Research; Univ. of Chicago

    2001-06-01

    To adequately assess the effects of atmospheric aerosols on climate, their optical constants (scattering and absorption coefficients) must be known. The absorption and scattering coefficients of the aerosols are derived from the real and imaginary parts of the complex refractive index and are dependent on their size and chemical composition. Because aerosol properties vary significantly with location, it is difficult to assign values for the absorption and scattering of solar radiation by aerosols in models of global climate change. This study reports a new method of collecting size-fractionated atmospheric aerosol samples for the purpose of directly measuring their transmission and reflectance spectra followed by the determination of the complex refractive index across the entire atmospherically relevant spectral range. The samples were collected with a modified Sierra high-volume cascade impactor with the usual filter collection surfaces replaced with Teflon sheets machined to hold quartz (ultraviolet [UV]/visible transparent) and/or silver chloride (infrared transparent) sample collection plates. Reflectance and transmission spectra can be obtained on the aerosol samples directly as a function of wavelength, from 280 nm to 2.5 m, with an integrating sphere coupled to an UV/visible or a Fourier transform infrared (FTIR) spectrophotometer. The effective real and imaginary components of the refractive index of the bulk sample material can then be approximated, as a function of wavelength, from the sample spectra. Preliminary results are presented for carbon soot samples generated in the laboratory and for standard diesel soot samples in the UV/visible spectral range. These are compared to results obtained for size-fractionated atmospheric aerosol samples collected near Pasco, WA, West Mesa, AZ, and Argonne, IL.

  19. Complexity and accuracy of image registration methods in SPECT-guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Yin, L. S.; Tang, L.; Hamarneh, G.; Gill, B.; Celler, A.; Shcherbinin, S.; Fua, T. F.; Thompson, A.; Liu, M.; Duzenli, C.; Sheehan, F.; Moiseenko, V.

    2010-01-01

    The use of functional imaging in radiotherapy treatment (RT) planning requires accurate co-registration of functional imaging scans to CT scans. We evaluated six methods of image registration for use in SPECT-guided radiotherapy treatment planning. Methods varied in complexity from 3D affine transform based on control points to diffeomorphic demons and level set non-rigid registration. Ten lung cancer patients underwent perfusion SPECT-scans prior to their radiotherapy. CT images from a hybrid SPECT/CT scanner were registered to a planning CT, and then the same transformation was applied to the SPECT images. According to registration evaluation measures computed based on the intensity difference between the registered CT images or based on target registration error, non-rigid registrations provided a higher degree of accuracy than rigid methods. However, due to the irregularities in some of the obtained deformation fields, warping the SPECT using these fields may result in unacceptable changes to the SPECT intensity distribution that would preclude use in RT planning. Moreover, the differences between intensity histograms in the original and registered SPECT image sets were the largest for diffeomorphic demons and level set methods. In conclusion, the use of intensity-based validation measures alone is not sufficient for SPECT/CT registration for RTTP. It was also found that the proper evaluation of image registration requires the use of several accuracy metrics.

  20. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the NIM, China and the BIPM in 60Co gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D.; Wang, K.; Fan, Y.; Jin, S.; Yang, X.

    2016-01-01

    An indirect comparison of the standards for air kerma of the National Institute of Metrology (NIM), China and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in November 2015. The comparison result, evaluated as a ratio of the NIM and the BIPM standards for air kerma, is 0.9997 with a combined standard uncertainty of 2.7 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  1. Key comparison BIPM.RI(I)-K5 of the air kerma standards of the NIM, China, and the BIPM in 137Cs gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D. T.; Li, D.; Wang, P.

    2015-01-01

    A direct comparison of the standards for air kerma of the National Institute of Metrology (NIM), Beijing, China, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in September 2014. The comparison result, evaluated as a ratio of the NIM and the BIPM standards for air kerma, is 0.9967 with a combined standard uncertainty of 2.1 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  2. Euroforgen-NoE collaborative exercise on LRmix to demonstrate standardization of the interpretation of complex DNA profiles.

    PubMed

    Prieto, L; Haned, H; Mosquera, A; Crespillo, M; Alemañ, M; Aler, M; Alvarez, F; Baeza-Richer, C; Dominguez, A; Doutremepuich, C; Farfán, M J; Fenger-Grøn, M; García-Ganivet, J M; González-Moya, E; Hombreiro, L; Lareu, M V; Martínez-Jarreta, B; Merigioli, S; Milans Del Bosch, P; Morling, N; Muñoz-Nieto, M; Ortega-González, E; Pedrosa, S; Pérez, R; Solís, C; Yurrebaso, I; Gill, P

    2014-03-01

    There has been very little work published on the variation of reporting practices of mixtures between laboratories, but it has been previously demonstrated that there is little consistency. This is because there is no current uniformity of practice, so different laboratories will operate using different rules. The interpretation of mixtures is not solely a matter of using some software to provide 'an answer'. An assessment of a case will usually begin with a consideration of the circumstances of a crime. Assumptions made about the numbers of contributors follow from an examination of the electropherogram(s)--and these may differ between the prosecution and the defence hypotheses. There may be a necessity to evaluate several sets of hypotheses for any given case if the circumstances are uncertain. Once the hypotheses are formulated, the mathematical analysis is complex and can only be accomplished by the use of specialist software. In order to obtain meaningful results, it is essential that scientists are trained, not only in the use of the software, but also in the methodology to understand the likelihood ratio concept that is used. The Euroforgen-NoE initiative has developed a training course that utilizes the LRmix program to carry out the calculations. This software encompasses the recommendations of the ISFG DNA commissions on mixture interpretation and is able to interpret samples that may come from two or more contributors and may also be partial profiles. Recently, eighteen different laboratories were trained in the methodology. Afterwards they were asked to independently analyze two different cases with partial mixture DNA evidence and to write a statement court-report. We show that by introducing a structured training programme, it is possible to demonstrate, for the first time, that a high degree of standardization, leading to uniformity of results can be achieved by participating laboratories.

  3. Understanding the complexities of private standards in global agri-food chains as they impact developing countries.

    PubMed

    Henson, Spencer; Humphrey, John

    2010-01-01

    The increasing prevalence of private standards governing food safety, food quality and environmental and social impacts of agri-food systems has raised concerns about the effects on developing countries, as well as the governance of agri-food value chains more broadly. It is argued that current debates have been 'clouded' by a failure to recognise the diversity of private standards in terms of their institutional form, who develops and adopts these standards and why. In particular, there is a need to appreciate the close inter-relationships between public regulations and private standards and the continuing ways in which private standards evolve.

  4. [Improved results of the trachea scar stenosis treatment by inclusion in the complex therapy of combined application diprospan and low-intensity infrared laser radiation].

    PubMed

    Israfilova, S B; Gasymov, É M

    2013-09-01

    The experience of treating 61 patients over the rumen of stenosis of the trachea was summarizes. To improve the results suggested inclusion complex diprospan treatment in combination with low intensity infrared laser radiation. The advantages of the proposed method of treatment of tracheal stenosis scarring are reduced severity of chronic inflammation, reducing the proliferation of granulation tissue.

  5. Radiation hybrid maps of D-genome of Aegilops tauschii and their application in sequence assembly of large and complex plant genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The large and complex genome of bread wheat (Triticum aestivum L., ~17 Gb) requires high-resolution genome maps saturated with ordered markers to assist in anchoring and orienting BAC contigs/ sequence scaffolds for whole genome sequence assembly. Radiation hybrid (RH) mapping has proven to be an e...

  6. EDITORIAL Complexity of advanced radiation therapy necessitates multidisciplinary inquiry into dose reconstruction and risk assessment Complexity of advanced radiation therapy necessitates multidisciplinary inquiry into dose reconstruction and risk assessment

    NASA Astrophysics Data System (ADS)

    Newhauser, Wayne

    2010-07-01

    The availability of low-cost, high-performance computing is rapidly transforming the landscape of cancer research. Computational techniques are playing an increasingly important role and have become the third major method of scientific inquiry, supplementing traditional methods of observation and theory. This evolution began in the 1940s when high-performance computing techniques were developed for military applications, including radiation transport calculations. These same basic methods are still widely utilized in a broad spectrum of computational problems in medicine, including radiation cancer therapy (Rogers 2006, Spezi 2010) and radiologic diagnostic imaging (Doi 2006, Kalender 2006). Supercomputing is also now being used to study the genetics and genomics of cancer (Geurts van Kessel 2010), with application to gene sequencing (Mardis 2008), genome-wide association studies (Pearson and Manolio 2008), biomolecular dynamics (Sanbonmatsu and Tung 2007) and systems biology (Wolkenhauer et al 2010). The extensive and growing body of literature is evidence of a remarkable expansion of activity and enormous boost to cancer research from the application of high-performance computing. Early successes were facilitated by inexpensive computing resources and advances in modeling algorithms. Many contemporary models require extensive approximations and phenomenological approaches. In fact, many critical problems remain computationally intractable; the underlying physical and biological processes are simply too complex to model with contemporary theory and computing capacity. In the future, a vast stream of new insights will flow from studies that use increasingly exact models and first-principles approaches. Hence, in the war on cancer the present status of computational research could be summarized as the beginning of the beginning. For these reasons, there is a vital need for scientists and clinicians to periodically discuss progress and future plans regarding

  7. Relation of structure to function for the US reference standard endotoxin after exposure to /sup 60/Co radiation, Interim report, September 1984-December 1985

    SciTech Connect

    Suba, E.A.; Elin, R.J.

    1986-01-01

    The structure and function of the highly purified U.S. reference standard endotoxin (RSE) were studied after exposure to ionizing radiation from a /sup 60/Co source. With increasing doses of radiation, the trilaminar ribbon-like structure of untreated endotoxin exhibited focal swelling, after which only spherical particles were seen by electron microscopy. These morphological changes were paralleled by the respective loss of O-side chain-repeating units and pieces of the R-core from the lipopolysaccharide molecules, as demonstrated by electrophoresis. The biologic function of the irradiated endotoxin was assessed with a variety of tests. At higher doses of radiation, a direct relation was observed between the degradation of the molecular and supramolecular structure and the loss of biologic function. At lower doses of radiation, however, there was variability among the functional assays in their rate of change with progressive irradiation of the RSE. The results suggest that the carbohydrate moiety plays an important role both in determining the supramolecular structure and in modulating certain biologic activities of bacterial endotoxins.

  8. Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Okuda, Kengo; Svendsen, Erik Robert; Kunugita, Naoki

    2015-05-01

    The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no deaths or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious diseases. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered.

  9. Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant

    PubMed Central

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Okuda, Kengo; Svendsen, Erik Robert; Kunugita, Naoki

    2015-01-01

    The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no deaths or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious diseases. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered. PMID:25413928

  10. Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant.

    PubMed

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Okuda, Kengo; Svendsen, Erik Robert; Kunugita, Naoki

    2015-05-01

    The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no deaths or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious diseases. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered. PMID:25413928

  11. An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    SciTech Connect

    Iselin, L.H.

    1992-12-31

    The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

  12. Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the PTB, Germany and the BIPM in 60Co gamma radiation

    NASA Astrophysics Data System (ADS)

    Kessler, C.; Burns, D. T.; Kapsch, R.-P.; Krauss, A.

    2016-01-01

    An indirect comparison has been made of the standards for absorbed dose to water in 60Co radiation of the Physikalisch-Technische Bundesanstalt, (PTB), Germany and of the Bureau International des Poids et Mesures (BIPM). The measurements at the BIPM were carried out in October 2015. The comparison result, based on the calibration coefficients for two transfer standards and evaluated as a ratio of the PTB and the BIPM standards for absorbed dose to water, is 0.9977 with a combined standard uncertainty of 3.8 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  13. 42 CFR Appendix E to Part 75 - Standards for Accreditation of Educational Programs for Radiation Therapy Technologists

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... clinical education center is used, each must meet the standards of a major cancer management center. 3. When didactic preparation and supervised clinical education are not provided in the same institution... accredited institution and each clinical education center, clearly defining the responsibilities...

  14. 18FDG PET-CT standardized uptake value for the prediction of radiation pneumonitis in patients with lung cancer receiving radiotherapy

    PubMed Central

    ZHANG, YONG; YU, YONGHUA; YU, JINMING; FU, ZHENG; LIU, TONGHAI; GUO, SHOUFANG

    2015-01-01

    The present study aimed to determine if the standardized uptake value (SUV) determined with 18F-FDG PET-CT can be used to predict radiation pneumonitis (RP) in lung cancer patients who receive radiotherapy. A total of 40 patients with non-small cell lung cancer received 18F-FDG PET-CT examinations prior to and following radiotherapy. The average SUV of lung tissue prior to and following radiation were measured at differing radiation doses. SUV differences between patients with and without RP, and the SUV ratio of the irradiated lung tissues compared with that of non-irradiated lung tissues (L/B) were compared. There were no differences in the mean SUV between the RP and no RP groups prior to radiotherapy. There were also no significant differences in the mean SUV of lung tissue within groups or between the no RP and RP groups with radiation doses of <5 Gy, 5 to ≤14.9 Gy and 15 to ≤34.9 Gy (all P>0.05) following radiotherapy. There were, however, statistically significant differences in the mean SUV of lung tissue within groups or between the no RP and RP groups with doses of ≥60 Gy prior to therapy and 35 to ≤59.9 Gy and ≥60 Gy following therapy (all P<0.05). When the L/B ratio was ≥3, the incidence of RP was 50%, and when the L/B ratio was ≥2.5 the incidence was 40.7%. When the L/B ratio was <2, there were no cases of RP. In conclusion, the present study indicates that 18F-FDG PET-CT can be used to predict RP by L/B ratio. PMID:26722262

  15. Real-time dual-mode standard/complex Fourier-domain OCT system using graphics processing unit accelerated 4D signal processing and visualization

    NASA Astrophysics Data System (ADS)

    Zhang, Kang; Kang, Jin U.

    2011-03-01

    We realized a real-time dual-mode standard/complex Fourier-domain optical coherence tomography (FD-OCT) system using graphics processing unit (GPU) accelerated 4D (3D+time) signal processing and visualization. For both standard and complex FD-OCT modes, the signal processing tasks were implemented on a dual-GPUs architecture that included λ-to-k spectral re-sampling, fast Fourier transform (FFT), modified Hilbert transform, logarithmic-scaling, and volume rendering. The maximum A-scan processing speeds achieved are >3,000,000 line/s for the standard 1024-pixel-FD-OCT, and >500,000 line/s for the complex 1024-pixel-FD-OCT. Multiple volumerendering of the same 3D data set were preformed and displayed with different view angles. The GPU-acceleration technique is highly cost-effective and can be easily integrated into most ultrahigh speed FD-OCT systems to overcome the 3D data processing and visualization bottlenecks.

  16. Standard and goal-oriented adaptive mesh refinement applied to radiation transport on 2D unstructured triangular meshes

    SciTech Connect

    Yaqi Wang; Jean C. Ragusa

    2011-02-01

    Standard and goal-oriented adaptive mesh refinement (AMR) techniques are presented for the linear Boltzmann transport equation. A posteriori error estimates are employed to drive the AMR process and are based on angular-moment information rather than on directional information, leading to direction-independent adapted meshes. An error estimate based on a two-mesh approach and a jump-based error indicator are compared for various test problems. In addition to the standard AMR approach, where the global error in the solution is diminished, a goal-oriented AMR procedure is devised and aims at reducing the error in user-specified quantities of interest. The quantities of interest are functionals of the solution and may include, for instance, point-wise flux values or average reaction rates in a subdomain. A high-order (up to order 4) Discontinuous Galerkin technique with standard upwinding is employed for the spatial discretization; the discrete ordinates method is used to treat the angular variable.

  17. Elementally specific electron-positron annihilation radiation emitted from ion cores of group-V impurity-vacancy complexes in germanium

    NASA Astrophysics Data System (ADS)

    Arutyunov, N. Yu.; Emtsev, V. V.

    2007-12-01

    High-momentum component (HMC) of the electron-positron annihilation has been detected by the angular correlation of annihilation radiation (ACAR) technique in order to obtain elementally specific information about the ion cores of the donor-vacancy complexes (DV) formed by irradiation with 60Co γ-rays at Tirr.≈280 K in oxygen-lean n-Ge doped with group-V donors (D=As, Sb, and Bi). The probability of annihilation of positrons with the core electrons of DV complexes reconstructed from ACAR spectra increases in passing from AsV to SbV and BiV complexes. This increase correlates with the shift of the D atom from its regular position towards the vacancy site predicted by the results of spin-density functional modeling study. The data obtained suggest inward relaxation of the ion cores of DV complexes (including the one directed inward towards the vacancy).

  18. Stoichiometry determination of the MP1-p14 complex using a novel and cost-efficient method to produce an equimolar mixture of standard peptides.

    PubMed

    Holzmann, Johann; Pichler, Peter; Madalinski, Mathias; Kurzbauer, Robert; Mechtler, Karl

    2009-12-15

    Determination of protein complex stoichiometry can be achieved by absolute quantification of the interacting constituents based on isotope dilution mass spectrometry. Current available platforms for the generation of standard peptides are cost-intensive and deliver variable results concerning the equimolarity of the standard peptides. Here we describe a novel and cost-efficient method to generate an equimolar mixture of standard peptides, which we call the equimolarity through equalizer peptide (EtEP) strategy. The rationale of the strategy allows equalization of internal standard peptides and absolute quantification of any protein of interest via a single peptide, from which the exact amount was determined by amino acid analysis. This and the use of the mTRAQ reagent significantly decrease the costs of absolute quantification and stoichiometry determination. We used the EtEP strategy to determine the MP1-p14 complex stoichiometry of two different concentrations, one simulating a condition following tandem affinity purification. Absolute quantification of MP1-p14 was performed on two different mass spectrometers, and the 1:1 stoichiometry was confirmed with high accuracy and precision. On the basis of the quantification of MP1-p14, we demonstrate the importance to assess completeness of protein digestion and discuss the use of peptides containing labile amino acids and the choice of instrumentation.

  19. Establishment of an x-ray standard calibration curve by conventional dicentric analysis as prerequisite for accurate radiation dose assessment.

    PubMed

    Beinke, Christina; Braselmann, Herbert; Meineke, Viktor

    2010-02-01

    The dicentric assay was established to carry out cytogenetic biodosimetry after suspected radiation overexposure, including a comprehensive documentation system to record the processing of the specimen, all data, results, and stored information. As an essential prerequisite for retrospective radiation dose assessment, a dose-response curve for dicentric induction by in vitro x-ray irradiation of peripheral blood samples was produced. The accelerating potential was 240 kV (maximum photon energy: 240 keV). A total of 8,377 first-division metaphases of four healthy volunteers were analyzed after exposure to doses ranging from 0.2 to 4.0 Gy at a dose rate of 1.0 Gy min. The background level of aberrations at 0-dose was determined by the analysis of 14,522 first-division metaphases obtained from unirradiated blood samples of 10 healthy volunteers. The dose-response relationship follows a linear-quadratic equation, Y = c + alphaD + betaD, with the coefficients c = 0.0005 +/- 0.0002, alpha = 0.043 +/- 0.006, and beta = 0.063 +/- 0.004. The technical competence and the quality of the calibration curve were assessed by determination of the dose prediction accuracy in an in vitro experiment simulating whole-body exposures within a range of 0.2 to 2.0 Gy. Dose estimations were derived by scoring up to 500-1,000 metaphase spreads or more (full estimation mode) and by evaluating only 50 metaphase spreads (triage mode) per subject. The triage mode was applied by performing manifold evaluations of the full estimation data in order to test the robustness of the curve for triage purposes and to assess possible variations among the estimated doses referring to a single exposure and preparation.

  20. Noise-immune complex correlation for vasculature imaging based on standard and Jones-matrix optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Li, En; Miura, Masahiro; Yasuno, Yoshiaki

    2016-03-01

    A new optical coherence angiography (OCA) method, called correlation mapping OCA (cmOCA), is presented by using the SNR-corrected complex correlation. An SNR-correction theory for the complex correlation calculation is presented. The method also integrates a motion-artifact-removal method for the sample motion induced decorrelation artifact. The theory is further extended to compute more reliable correlation by using multi- channel OCT systems, such as Jones-matrix OCT. The high contrast vasculature imaging of in vivo human posterior eye has been obtained. Composite imaging of cmOCA and degree of polarization uniformity indicates abnormalities of vasculature and pigmented tissues simultaneously.

  1. Crafting Coherence from Complex Policy Messages: Educators' Perceptions of Special Education and Standards-Based Accountability Policies

    ERIC Educational Resources Information Center

    Russell, Jennifer Lin; Bray, Laura E.

    2013-01-01

    Federal special education and accountability policies requires that educators individualize instruction for students with disabilities, while simultaneously ensuring that the vast majority of these students meet age-based grade-level standards and assessment targets. In this paper, we examine this dynamic interplay between policies through…

  2. Estimation of a Self-Consistent Set of Radiobiological Parameters From Hypofractionated Versus Standard Radiation Therapy of Prostate Cancer

    SciTech Connect

    Pedicini, Piernicola; Strigari, Lidia; Benassi, Marcello

    2013-04-01

    Purpose: To determine a self-consistent set of radiobiological parameters in prostate cancer. Methods and Materials: A method to estimate intrinsic radiosensitivity (α), fractionation sensitivity (α/β), repopulation doubling time, number of clonogens, and kick-off time for accelerated repopulation of prostate cancer has been developed. Based on the generalized linear-quadratic model and without assuming the isoeffective hypothesis, the potential applications of the method were investigated using the clinical outcome of biochemical relapse-free survival recently reviewed in the literature. The strengths and limitations of the method, regarding the fitted parameters and 95% confidence intervals (CIs), are also discussed. Results: Our best estimate of α/β is 2.96 Gy (95% CI 2.41-3.53 Gy). The corresponding α value is 0.16 Gy{sup −1} (95% CI 0.14-0.18 Gy{sup −1}), which is compatible with a realistic number of clonogens: 6.5 × 10{sup 6} (95% CI 1.5 × 10{sup 6}-2.1 × 10{sup 7}). The estimated cell doubling time is 5.1 days (95% CI 4.2-7.2 days), very low if compared with that reported in the literature. This corresponds to the dose required to offset the repopulation occurring in 1 day of 0.52 Gy/d (95% CI 0.32-0.68 Gy/d). However, a long kick-off time of 31 days (95% CI 22-41 days) from the start of radiation therapy was found. Conclusion: The proposed analytic/graphic method has allowed the fitting of clinical data, providing a self-consistent set of radiobiological parameters for prostate cancer. With our analysis we confirm a low value for α/β with a correspondingly high value of intrinsic radiosensitivity, a realistic average number of clonogens, a long kick-off time for accelerated repopulation, and a surprisingly fast repopulation that suggests the involvement of subpopulations of specifically tumorigenic stem cells during continuing radiation therapy.

  3. Influence of instability of laser radiation on accuracy of record and reading of the information of diagnostic complex Intest 1

    NASA Astrophysics Data System (ADS)

    Moguilnaia, T. Y.; Botikov, A.; Agibalov, A. A.; Kosenkov, E.

    2005-09-01

    The theoretical and the experimental researches of spectra of absent-minded radiation in medium containing viruses of the influenza, the hepatitis C and smallpox of the rabbit were carried out. The noises arising at a stage of generation of radiation in biological structure of a virus have been investigated. It has been shown, that the intensity of the parasitic luminescence is the least if solvent is alcohol and the greatest if solvent is water.

  4. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography

    PubMed Central

    Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Miura, Masahiro; Yasuno, Yoshiaki

    2016-01-01

    This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients’ eyes can be obtained. PMID:27446673

  5. [Substantiation of a complex of radiation-hygienic approaches to the management of very low-level waste].

    PubMed

    Korenkov, I P; Lashchenova, T N; Shandala, N K

    2015-01-01

    In the article there are presented materials on radiation-hygienic approaches to the treatment of very low level radioactive waste (VLLW) and industrial waste containing radionuclides. There is done detailed information on radiation-hygienic principles and criteria for the assurance ofradiation safety in the collection, transportation, storage and processing of VLLW as a category of radioactive waste.. Particular attention is paid to the problem of designing VLLW landfill site choice, system of radiation monitoring in operation and decommissioning of the landfill. There are presented data about the criteria for the release of VLLW buried at the site, from regulatory control. Also there are considered in detail the radiation-hygienic requirements for radiation safety of industrial waste containing radionuclides for which there is assumed unlimited and limited use of solid materials in economic activity, based on the requirements ofthe revised Basic Sanitary Rules for Radiation Safety - 99/2010. There are considered basic requirements for the organization of industrial waste landfill. As an example, there-are presented the hygiene requirements for industrial waste management and results of waste categorization in Northern Federal Enterprise for Radioactive Waste Management. PMID:26031036

  6. The radiative leptonic decays D0 -> e+ e-γ ,μ ^+μ ^-γ in the standard model and beyond

    NASA Astrophysics Data System (ADS)

    Fajfer, S.; Singer, P.; Zupan, J.

    2003-03-01

    We present a calculation of the rare decay modes D^0 to e^+ e^- γ and D^0 to μ^+μ^- γ in the framework of the standard model. For the short distance part we have derived QCD corrections to the Wilson coefficients involved, including C9. The latter is found to be strongly suppressed by the corrections, leading to diminished values for the cto u l^+l^- branching ratios in the 10-10 range. Within SM the exclusive decays are dominated by long distance effects. Non-resonant contributions are estimated using heavy quark and chiral symmetries to be at the level of 10%, compared to the contributions arising from D^0to V γto l^+l^- γ, with V = ρ, ω, φ. The total SM branching ratio is predicted to be in the range (1-3)× 10^{-9}. We also consider contributions coming from MSSM with and without R parity conservation. The effects from MSSM are significant only for the R parity violating case. Such contributions enhance the branching ratio D^0 to μ^+μ^- γ to lesssim 0.5 × 10^{-7}, based on appropriately allowed values for C9 and C10. This selects D^0 to μ^+μ^- γ as a possible probe of new physics.

  7. An internal standard approach for homogeneous TR-FRET immunoassays facilitates the detection of bacteria, biomarkers, and toxins in complex matrices.

    PubMed

    Cohen, Noam; Zahavy, Eran; Zichel, Ran; Fisher, Morly

    2016-07-01

    The recent development of a homogeneous time-resolved Förster resonance energy transfer (TR-FRET) immunoassay enables one-step, rapid (minutes), and direct detection compared to the multistep, time-consuming (hours), heterogeneous ELISA-type immunoassays. The use of the time-resolved effect of a donor lanthanide complex with a delay time of microseconds and large Stokes shift enables the separation of positive signals from the background autofluorescence of the sample. However, this study shows that the sample matrices directly interfere with donor fluorescence and that interference cannot be eliminated by time-resolved settings alone. Moreover, the reduction in donor emission did not appear to be equivalent to the reduction in acceptor emission, resulting in incorrect FRET signal measurements. To overcome this limitation, an internal standard approach was developed using an isotype control antibody. This new approach was used to develop TR-FRET assays for rapid detection (15-30 min) of Bacillus anthracis spores and botulinum toxin (type E) in beverages, which are major concerns in bioterrorism involving deliberate food contamination. Additionally, we demonstrate the detection of B. anthracis-secreted protective antigen (PA) and the Yersinia pestis-secreted markers F1 and LcrV in blood cultures, which are early markers of bacteremia in infected hosts following a possible bioterror attack. The use of an internal standard enables the calculation of correct ΔF values without the need for an external standard. Thus, the use of the internal standard approach in homogeneous immunoassays facilitates the examination of any sample regardless of its origin, and therefore expands the applicability of TR-FRET assays for complex matrices. PMID:27236318

  8. Approximate method for calculating the radiation from a moving charge in the presence of a complex object.

    PubMed

    Belonogaya, Ekaterina S; Tyukhtin, Andrey V; Galyamin, Sergey N

    2013-04-01

    An approximate method for calculating the radiation from a moving charge in the presence of a dielectric object is developed. The method is composed of two steps. The first step is calculation of the field in the medium without considering the external boundaries of the object, and the second step is an approximate (ray-optical) calculation of the wave propagation outside the object. As a test problem, we consider the case of a charge crossing a dielectric plate. Computations of the field are performed using exact and approximate methods. It is shown that the results agree well. Additionally, we apply the method under consideration to the case of a cone-shaped object with a vacuum channel. The radiation energy spectral density as a function of the location of the observation point and the problem's parameters is given. In particular, the convergent radiation effect is described. PMID:23679539

  9. Complex Parts, Complex Data: Why You Need to Understand What Radiation Single Event Testing Data Does and Doesn't Show and the Implications Thereof

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.; Berg, Melanie D.

    2015-01-01

    Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks from single particle event testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means. Its all about understanding actual risks and not making assumptions.

  10. Complex Parts, Complex Data: Why You Need to Understand What Radiation Single Event Testing Data Does and Doesn't Show and the Implications Thereof

    NASA Technical Reports Server (NTRS)

    Label, Kenneth A.; Berg, Melanie D.

    2016-01-01

    Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks from single particle event testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means. Its all about understanding actual risks and not making assumptions.

  11. Functional analysis via standardized whole-blood stimulation systems defines the boundaries of a healthy immune response to complex stimuli.

    PubMed

    Duffy, Darragh; Rouilly, Vincent; Libri, Valentina; Hasan, Milena; Beitz, Benoit; David, Mikael; Urrutia, Alejandra; Bisiaux, Aurélie; Labrie, Samuel T; Dubois, Annick; Boneca, Ivo G; Delval, Cécile; Thomas, Stéphanie; Rogge, Lars; Schmolz, Manfred; Quintana-Murci, Lluis; Albert, Matthew L

    2014-03-20

    Standardization of immunophenotyping procedures has become a high priority. We have developed a suite of whole-blood, syringe-based assay systems that can be used to reproducibly assess induced innate or adaptive immune responses. By eliminating preanalytical errors associated with immune monitoring, we have defined the protein signatures induced by (1) medically relevant bacteria, fungi, and viruses; (2) agonists specific for defined host sensors; (3) clinically employed cytokines; and (4) activators of T cell immunity. Our results provide an initial assessment of healthy donor reference values for induced cytokines and chemokines and we report the failure to release interleukin-1α as a common immunological phenotype. The observed naturally occurring variation of the immune response may help to explain differential susceptibility to disease or response to therapeutic intervention. The implementation of a general solution for assessment of functional immune responses will help support harmonization of clinical studies and data sharing.

  12. Acid phosphatase complex from the freshwater snail Viviparus viviparus L. under standard conditions and intoxication by cadmium ions.

    PubMed

    Tsvetkov, I L; Popov, A P; Konichev, A S

    2003-12-01

    Acid phosphatases differing in both subcellular localization and substrate specificity were isolated for the first time from the liver of the freshwater snail Viviparus viviparus L. by preparative isoelectrofocusing. One of five characterized phosphatases is highly specific to ADP and the others can hydrolyze (at variable rate) a series of natural substrates. A scheme is proposed for the involvement of the studied phosphatases in carbohydrate metabolism. We have also studied some peculiarities of the effect of Cd2+ in vitro and in vivo on the activities of individual components of the acid phosphatase complex and corresponding changes in metabolism of the freshwater snail as a new test-object allowing the estimation of toxicity in water.

  13. Expression of BRC repeats in breast cancer cells disrupts the BRCA2-Rad51 complex and leads to radiation hypersensitivity and loss of G(2)/M checkpoint control.

    PubMed

    Chen, C F; Chen, P L; Zhong, Q; Sharp, Z D; Lee, W H

    1999-11-12

    BRCA2 is a breast tumor suppressor with a potential function in the cellular response to DNA damage. BRCA2 binds to Rad51 through its BRC repeats. In support of the biological significance of this interaction, we found that the complex of BRCA2 and Rad51 in breast cancer MCF-7 cells was diminished upon conditional expression of a wild-type, but not a mutated, BRC4 repeat using the tetracycline-inducible system. Cells expressing a wild-type BRC4 repeat showed hypersensitivity to gamma-irradiation, an inability to form Rad51 radiation-induced foci, and a failure of radiation-induced G(2)/M, but not G(1)/S, checkpoint control. These results strongly suggest that the interaction between BRCA2 and Rad51 mediated by BRC repeats is critical for the cellular response to DNA damage.

  14. Theoretical Insights into the Photo-Deactivation of Emitting Triplet Excited State of (C^N)Pt(O^O) Complexes: Radiative and Nonradiative Decay Processes.

    PubMed

    Xu, Yanyan; Luo, Yafei; Li, Ming; He, Rongxing; Shen, Wei

    2016-09-01

    In this study, density functional theory (DFT) and time-dependent DFT were employed to elucidate the photo-deactivation mechanisms of (C^N)Pt(O^O) complexes 1-4 (where C^N = 2-phenylpyridine derivatives, O^O = dipivolylmethanoate). To make thorough understanding of the radiative decay, the singlet-triplet splitting energies ΔE(Sn-T1) (n = 1, 2, 3, 4, ...), transition dipole moment μ(Sn) for S0-Sn transitions and the spin-orbit coupling (SOC) matrix elements ⟨T1|HSOC|Sn⟩ were all calculated. Moreover, the spin-orbit coupling between T1 and S0 ⟨T1|HSOC|S0⟩ and Huang-Rhys factors were calculated to estimate the temperature-independent nonradiative decay processes. Meanwhile, the thermal deactivation via metal-centered (3)MC was described to analyze the temperature-dependent nonradiative decay processes. As a result, the effective SOC interaction between the lowest triplet and singlet excited states successfully rationalize why complexes 1 and 3 have higher radiative decay rate constant than that of complex 2, while the larger ⟨T1|HSOC|S0⟩ and lower energy barrier for thermal deactivation in 3 reasonably explains why 3 has larger nonradiative rate than that of 1 and 2. Consequently, it can be concluded that it is the ⟨T1|HSOC|S0⟩ and thermal population of (3)MC that account for the nonemissive behavior of (C^N)Pt(O^O) complexes, and controlling π-conjugation is an efficient method for tuning phosphorescence properties of transition-metal complexes. PMID:27517617

  15. Bcl2 inhibits recruitment of Mre11 complex to DNA double-strand breaks in response to high-linear energy transfer radiation

    PubMed Central

    Xie, Maohua; Park, Dongkyoo; You, Shuo; Li, Rui; Owonikoko, Taofeek K.; Wang, Ya; Doetsch, Paul W.; Deng, Xingming

    2015-01-01

    High-linear energy transfer ionizing radiation, derived from high charge (Z) and energy (E) (HZE) particles, induces clustered/complex DNA double-strand breaks (DSBs) that include small DNA fragments, which are not repaired by the non-homologous end-joining (NHEJ) pathway. The homologous recombination (HR) DNA repair pathway plays a major role in repairing DSBs induced by HZE particles. The Mre11 complex (Mre11/Rad50/NBS1)-mediated resection of DSB ends is a required step in preparing for DSB repair via the HR DNA repair pathway. Here we found that expression of Bcl2 results in decreased HR activity and retards the repair of DSBs induced by HZE particles (i.e. 56iron and 28silicon) by inhibiting Mre11 complex activity. Exposure of cells to 56iron or 28silicon promotes Bcl2 to interact with Mre11 via the BH1 and BH4 domains. Purified Bcl2 protein directly suppresses Mre11 complex-mediated DNA resection in vitro. Expression of Bcl2 reduces the ability of Mre11 to bind DNA following exposure of cells to HZE particles. Our findings suggest that, after cellular exposure to HZE particles, Bcl2 may inhibit Mre11 complex-mediated DNA resection leading to suppression of the HR-mediated DSB repair in surviving cells, which may potentially contribute to tumor development. PMID:25567982

  16. On application of the complex demodulation procedure for VLBI data analysis: consistecy check with the standard approach using the long periodic EOP components

    NASA Astrophysics Data System (ADS)

    Brzezinski, Aleksander; Wielgosz, Agata; Boehm, Sigrid

    2014-05-01

    In the recent work (Boehm et al., J. Geodynamics, 62 (2012) 56-68) we demonstrated the application of the complex demodulation technique to VLBI parameter estimation for determination of the Earth orientation parameters (EOP). This technique enables simultaneous estimation of the long period components of polar motion (x,y), dUT1 (=UT1-UTC) and nutation (celestial pole offsets dX,dY) as well as the high frequency (diurnal, semidiurnal, ...) components of polar motion and dUT1. In this work we address the problem of consistency of the complex demodulation with the conventional approach to the EOP estimation. For this purpose we perform an analysis of the long periodic time series x, y, dUT1, dX, dY derived by the complex demodulation algorithm implemented in the Vienna VLBI Software (VieVS). Next, we compare those series to the EOP series derived by the standard VieVS run as well as to the other available EOP data sets.

  17. Experimental approach and atomistic simulations to investigate the radiation tolerance of complex oxides: Application to the amorphization of pyrochlores

    NASA Astrophysics Data System (ADS)

    Sattonnay, G.; Thomé, L.; Sellami, N.; Monnet, I.; Grygiel, C.; Legros, C.; Tetot, R.

    2014-05-01

    Both experimental approach and atomistic simulations are performed in order to investigate the influence of the composition of pyrochlores on their radiation tolerance. Therefore, Gd2Ti2O7 and Gd2Zr2O7 were irradiated with 4 MeV Au and 92 MeV Xe ions in order to study the structural changes induced by low and high-energy irradiations. XRD results show that, for both irradiations, the structural modifications are strongly dependent on the sample composition: Gd2Ti2O7 is readily amorphized, whereas Gd2Zr2O7 is transformed into a radiation-resistant anion-deficient fluorite structure. Using atomistic simulations with new interatomic potentials derived from the SMTB-Q model, the lattice properties and the defect formation energies were calculated in Gd2Ti2O7 and Gd2Zr2O7. Calculations show that titanates have a more covalent character than zirconates. Moreover, in Gd2Ti2O7 the formation of cation antisite defects leads to strong local distortions around Ti-defects and to a decrease of the Ti coordination number, which are not observed in Gd2Zr2O7. Thus, the radiation resistance is related to the defect stability: the accumulation of structural distortions around Ti-defects could drive the Gd2Ti2O7 amorphization induced by irradiation.

  18. Searching the Inclusive Lepton + Photon + Missing E(T) + b-quark Signature for Radiative Top Quark Decay and Non-Standard-Model Processes

    SciTech Connect

    Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-06-01

    In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton ({ell}), a photon ({gamma}), significant transverse momentum imbalance (E{sub T}), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at {radical}s = 1.96 TeV corresponding to 1.9 fb{sup -1} of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 {ell}{gamma}bE{sub T} events versus an expectation of 31.0{sub -3.5}{sup +4.1} events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, t{bar t} + {gamma}. In the data we observe 16 t{bar t}{gamma} candidate events versus an expectation from non-top-quark SM sources of 11.2{sub -2.1}{sup +2.3}. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the t{bar t} cross section to be 0.15 {+-} 0.08 pb.

  19. KEY COMPARISON: COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation

    NASA Astrophysics Data System (ADS)

    Büermann, L.; Oborin, A. V.; Dobrovosky, J.; Milevsky, V. S.; Walwyn Salas, G.; Lapenas, A.

    2009-01-01

    Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Distilling Complex Model Results into Simple Models for use in Assessing Compliance with Performance Standards for Low Level Waste Disposal Facilities

    SciTech Connect

    Arthur S. Rood

    2007-02-01

    Assessing the long term performance of waste disposal facility requires numerical simulation of saturated and unsaturated groundwater flow and contaminant transport. Complex numerical models have been developed to try to realistically simulate subsurface flow and transport processes. These models provide important information about system behavior and identify important processes, but may not be practical for demonstrating compliance with performance standards because of excessively long computer simulation times and input requirements. Two approaches to distilling the behavior of a complex model into simpler formulations that are practical for demonstrating compliance with performance objectives are examined in this paper. The first approach uses the information obtained from the complex model to develop a simple model that mimics the complex model behavior for stated performance objectives. The simple model may need to include essential processes that are important to assessing performance, such as time-variable infiltration and waste emplacement rates, subsurface heterogeneity, sorption, decay, and radioactive ingrowth. The approach was applied to a Low-Level Waste disposal site at the Idaho National Laboratory where a complex three dimensional vadose zone model was developed first to understand system behavior and important processes. The complex model was distilled down to a relatively simple one-dimensional vadose zone model and three-dimensional aquifer transport model. Comparisons between the simple model and complex model of vadose zone fluxes and groundwater concentrations showed relatively good agreement between the models for both fission and activation products (129I, 36Cl, 99Tc) and actinides (238U, 239Pu, 237Np). Application of the simple model allowed for Monte Carlo uncertainty analysis and simulations of numerous disposal and release scenarios. The second approach investigated was the response surface model. In the response surface model approach

  1. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge method

    SciTech Connect

    Ramadhar, Timothy R.; Zheng, Shao-Liang; Chen, Yu-Sheng

    2015-01-01

    This report describes complete practical guidelines and insights for the crystalline sponge method, which have been derived through the first use of synchrotron radiation on these systems, and includes a procedure for faster synthesis of the sponges. These guidelines will be applicable to crystal sponge data collected at synchrotrons or in-house facilities, and will allow researchers to obtain reliable high-quality data and construct chemically and physically sensible models for guest structural determination. A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal–organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collection times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine

  2. Quality Control of Biomedicinal Allergen Products – Highly Complex Isoallergen Composition Challenges Standard MS Database Search and Requires Manual Data Analyses

    PubMed Central

    Spiric, Jelena; Engin, Anna M.; Karas, Michael; Reuter, Andreas

    2015-01-01

    Allergy against birch pollen is among the most common causes of spring pollinosis in Europe and is diagnosed and treated using extracts from natural sources. Quality control is crucial for safe and effective diagnosis and treatment. However, current methods are very difficult to standardize and do not address individual allergen or isoallergen composition. MS provides information regarding selected proteins or the entire proteome and could overcome the aforementioned limitations. We studied the proteome of birch pollen, focusing on allergens and isoallergens, to clarify which of the 93 published sequence variants of the major allergen, Bet v 1, are expressed as proteins within one source material in parallel. The unexpectedly complex Bet v 1 isoallergen composition required manual data interpretation and a specific design of databases, as current database search engines fail to unambiguously assign spectra to highly homologous, partially identical proteins. We identified 47 non-allergenic proteins and all 5 known birch pollen allergens, and unambiguously proved the existence of 18 Bet v 1 isoallergens and variants by manual data analysis. This highly complex isoallergen composition raises questions whether isoallergens can be ignored or must be included for the quality control of allergen products, and which data analysis strategies are to be applied. PMID:26561299

  3. Competitive inhibition of carcinogen-activating CYP1A1 and CYP1B1 enzymes by a standardized complex mixture of PAH extracted from coal tar

    SciTech Connect

    Mahadevan, B.; Marston, C.P.; Luch, A.; Dashwood, W.M.; Brooks, E.; Pereira, C.; Doehmer, J.; Baird, W.M.

    2007-03-15

    A complex mixture of polycyclic aromatic hydrocarbons (PAH) extracted from coal tar, the Standard Reference Material (SRM) 1597, was recently shown to decrease the levels of DNA binding of the 2 strong carcinogens benzo(a)pyrene (BP) and dibenzo(a,l)pyrene (DBP) in the human mammary carcinoma-derived cell line MCF-7. The present study was designed to further elucidate the biochemical mechanisms involved in this inhibition process. We examined the effects of SRM 1597 on the metabolic activation of BP and DBP toward DNA-binding derivatives in Chinese hamster cells expressing either human cytochrome P450 (CYP) 1A1 or CYP1B1. The data obtained from biochemical experiments revealed that SRM 1597 competitively inhibited the activity of both human enzymes as analyzed by 7-ethoxyresorufin O-deethylation assays. While the Michaelis-Menten constant (K-M) was {lt} 0.4 {mu}M in the absence of SRM 1597, this value increased up to 1.12 (CYP1A1) or 4.45 {mu}M (CYP1B1) in the presence of 0.1 {mu} g/ml SRM 1597. Hence the inhibitory effects of the complex mixture on human CYP1B1 were much stronger when compared to human CYP1A1 Taken together, the decreases in PAH-DNA adduct formation on co-treatment with SRM 1597 revealed inhibitory effects on the CYP enzymes that convert carcinogenic PAH into DNA-binding metabolites. The implications for the tumorigenicity of complex environmental PAR mixtures are discussed.

  4. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge method.

    PubMed

    Ramadhar, Timothy R; Zheng, Shao Liang; Chen, Yu Sheng; Clardy, Jon

    2015-01-01

    A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal-organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collection times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine occupancies, discussion of the proper use of geometric and anisotropic displacement parameter restraints and constraints, and whether to perform solvent squeezing/masking. The single-crystal-to-single-crystal transformation process for the crystal sponges is also discussed. The presented general guidelines will be invaluable for researchers interested in using the crystalline sponge method at in-house diffraction or synchrotron facilities, will facilitate the collection and analysis of reliable high-quality data

  5. Randomized Noninferiority Trial of Reduced High-Dose Volume Versus Standard Volume Radiation Therapy for Muscle-Invasive Bladder Cancer: Results of the BC2001 Trial (CRUK/01/004)

    SciTech Connect

    Huddart, Robert A.; Hall, Emma; Hussain, Syed A.; Jenkins, Peter; Rawlings, Christine; Tremlett, Jean; Crundwell, Malcolm; Adab, Fawzi A.; Sheehan, Denise; Syndikus, Isabel; Hendron, Carey; Lewis, Rebecca; Waters, Rachel; James, Nicholas D.

    2013-10-01

    Purpose: To test whether reducing radiation dose to uninvolved bladder while maintaining dose to the tumor would reduce side effects without impairing local control in the treatment of muscle-invasive bladder cancer. Methods and Materials: In this phase III multicenter trial, 219 patients were randomized to standard whole-bladder radiation therapy (sRT) or reduced high-dose volume radiation therapy (RHDVRT) that aimed to deliver full radiation dose to the tumor and 80% of maximum dose to the uninvolved bladder. Participants were also randomly assigned to receive radiation therapy alone or radiation therapy plus chemotherapy in a partial 2 × 2 factorial design. The primary endpoints for the radiation therapy volume comparison were late toxicity and time to locoregional recurrence (with a noninferiority margin of 10% at 2 years). Results: Overall incidence of late toxicity was less than predicted, with a cumulative 2-year Radiation Therapy Oncology Group grade 3/4 toxicity rate of 13% (95% confidence interval 8%, 20%) and no statistically significant differences between groups. The difference in 2-year locoregional recurrence free rate (RHDVRT − sRT) was 6.4% (95% confidence interval −7.3%, 16.8%) under an intention to treat analysis and 2.6% (−12.8%, 14.6%) in the “per-protocol” population. Conclusions: In this study RHDVRT did not result in a statistically significant reduction in late side effects compared with sRT, and noninferiority of locoregional control could not be concluded formally. However, overall low rates of clinically significant toxicity combined with low rates of invasive bladder cancer relapse confirm that (chemo)radiation therapy is a valid option for the treatment of muscle-invasive bladder cancer.

  6. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: Practical guidelines for the crystalline sponge method

    DOE PAGESBeta

    Ramadhar, Timothy R.; Zheng, Shao -Liang; Chen, Yu -Sheng; Clardy, Jon

    2015-01-01

    A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal–organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collectionmore » times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine occupancies, discussion of the proper use of geometric and anisotropic displacement parameter restraints and constraints, and whether to perform solvent squeezing/masking. The single-crystal-to-single-crystal transformation process for the crystal sponges is also discussed. The presented general guidelines will be invaluable for researchers interested in using the crystalline sponge method at in-house diffraction or synchrotron facilities, will facilitate the collection and analysis of reliable high

  7. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: Practical guidelines for the crystalline sponge method

    SciTech Connect

    Ramadhar, Timothy R.; Zheng, Shao -Liang; Chen, Yu -Sheng; Clardy, Jon

    2015-01-01

    A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal–organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collection times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine occupancies, discussion of the proper use of geometric and anisotropic displacement parameter restraints and constraints, and whether to perform solvent squeezing/masking. The single-crystal-to-single-crystal transformation process for the crystal sponges is also discussed. The presented general guidelines will be invaluable for researchers interested in using the crystalline sponge method at in-house diffraction or synchrotron facilities, will facilitate the collection and analysis of

  8. Comparative effectiveness of a complex Ayurvedic treatment and conventional standard care in osteoarthritis of the knee – study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    Background Traditional Indian Ayurvedic medicine uses complex treatment approaches, including manual therapies, lifestyle and nutritional advice, dietary supplements, medication, yoga, and purification techniques. Ayurvedic strategies are often used to treat osteoarthritis (OA) of the knee; however, no systematic data are available on their effectiveness in comparison with standard care. The aim of this study is to evaluate the effectiveness of complex Ayurvedic treatment in comparison with conventional methods of treating OA symptoms in patients with knee osteoarthritis. Methods and design In a prospective, multicenter, randomized controlled trial, 150 patients between 40 and 70 years, diagnosed with osteoarthritis of the knee, following American College of Rheumatology criteria and an average pain intensity of ≥40 mm on a 100 mm visual analog scale in the affected knee at baseline will be randomized into two groups. In the Ayurveda group, treatment will include tailored combinations of manual treatments, massages, dietary and lifestyle advice, consideration of selected foods, nutritional supplements, yoga posture advice, and knee massage. Patients in the conventional group will receive self-care advice, pain medication, weight-loss advice (if overweight), and physiotherapy following current international guidelines. Both groups will receive 15 treatment sessions over 12 weeks. Outcomes will be evaluated after 6 and 12 weeks and 6 and 12 months. The primary endpoint is a change in the score on the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) after 12 weeks. Secondary outcome measurements will use WOMAC subscales, a pain disability index, a visual analog scale for pain and sleep quality, a pain experience scale, a quality-of-life index, a profile of mood states, and Likert scales for patient satisfaction, patient diaries, and safety. Using an adapted PRECIS scale, the trial was identified as lying mainly in the middle of the efficacy

  9. Toxicity of cobalt-complexed cyanide to Oncorhynchus mykiss, Daphnia magna, and Ceriodaphnia dubia: Potentiation by ultraviolet radiation and attenuation by dissolved organic carbon and adaptive UV tolerance

    USGS Publications Warehouse

    Little, E.E.; Calfee, R.D.; Theodorakos, P.; Brown, Z.A.; Johnson, C.A.

    2007-01-01

    Background. Cobalt cyanide complexes often result when ore is treated with cyanide solutions to extract gold and other metals. These have recently been discovered in low but significant concentrations in effluents from gold leach operations. This study was conducted to determine the potential toxicity of cobalt-cyanide complexes to freshwater organisms and the extent to which ultraviolet radiation (UV) potentiates this toxicity. Tests were also conducted to determine if humic acids or if adaptation to UV influenced sensitivity to the cyanide complexes. Methods. Rainbow trout (Oncorhynchus mykiss), Daphnia magna, and Ceriodaphnia dubia were exposed to potassium hexacyanocobaltate in the presence and absence of UV radiation, in the presence and absence of humic acids. Cyano-cobalt exposures were also conducted with C. dubia from cultures adapted to elevated UV. Results. With an LC50 concentration of 0.38 mg/L, cyanocobalt was over a 1000 times more toxic to rainbow trout in the presence of UV at a low, environmentally relevant irradiance level (4 ??W/cm2 as UVB) than exposure to this compound in the absence of UV with an LC50 of 112.9 mg/L. Toxicity was immediately apparent, with mortality occurring within an hour of the onset of exposure at the highest concentration. Fish were unaffected by exposure to UV alone. Weak-acid dissociable cyanide concentrations were observed in irradiated aqueous solutions of cyanocobaltate within hours of UV exposure and persisted in the presence of UV for at least 96 hours, whereas negligible concentrations were observed in the absence of UV. The presence of humic acids significantly diminished cyanocobalt toxicity to D. magna and reduced mortality from UV exposure. Humic acids did not significantly influence survival among C. dubia. C. dubia from UV-adapted populations were less sensitive to metallocyanide compounds than organisms from unadapted populations. Conclusions. The results indicate that metallocyanide complexes may pose a

  10. Time-resolved radiation chemistry: Dynamics of electron attachment to uracil following UV excitation of iodide-uracil complexes

    SciTech Connect

    King, Sarah B.; Yandell, Margaret A.; Stephansen, Anne B.; Neumark, Daniel M.

    2014-12-14

    Electron attachment to uracil was investigated by applying time-resolved photoelectron imaging to iodide-uracil (I{sup –}U) complexes. In these studies, an ultraviolet pump pulse initiated charge transfer from the iodide to the uracil, and the resulting dynamics of the uracil temporary negative ion were probed. Five different excitation energies were used, 4.00 eV, 4.07 eV, 4.14 eV, 4.21 eV, and 4.66 eV. At the four lowest excitation energies, which lie near the vertical detachment energy of the I{sup –}U complex (4.11 eV), signatures of both the dipole bound (DB) as well as the valence bound (VB) anion of uracil were observed. In contrast, only the VB anion was observed at 4.66 eV, in agreement with previous experiments in this higher energy range. The early-time dynamics of both states were highly excitation energy dependent. The rise time of the DB anion signal was ∼250 fs at 4.00 eV and 4.07 eV, ∼120 fs at 4.14 eV and cross-correlation limited at 4.21 eV. The VB anion rise time also changed with excitation energy, ranging from 200 to 300 fs for excitation energies 4.00–4.21 eV, to a cross-correlation limited time at 4.66 eV. The results suggest that the DB state acts as a “doorway” state to the VB anion at 4.00–4.21 eV, while direct attachment to the VB anion occurs at 4.66 eV.

  11. Randomized, Multicenter Trial on the Effect of Radiation Therapy on Plantar Fasciitis (Painful Heel Spur) Comparing a Standard Dose With a Very Low Dose: Mature Results After 12 Months' Follow-Up

    SciTech Connect

    Niewald, Marcus; Micke, Oliver; Graeber, Stefan; Schaefer, Vera; Scheid, Christine; Fleckenstein, Jochen; Licht, Norbert; Ruebe, Christian

    2012-11-15

    Purpose: To conduct a randomized trial of radiation therapy for painful heel spur, comparing a standard dose with a very low dose. Methods and Materials: Sixty-six patients were randomized to receive radiation therapy either with a total dose of 6.0 Gy applied in 6 fractions of 1.0 Gy twice weekly (standard dose) or with a total dose of 0.6 Gy applied in 6 fractions of 0.1 Gy twice weekly (low dose). In all patients lateral opposing 4- to 6-MV photon beams were used. The results were measured using a visual analogue scale, the Calcaneodynia score, and the SF12 health survey. The fundamental phase of the study ended after 3 months, and the follow-up was continued up to 1 year. Patients with insufficient pain relief after 3 months were offered reirradiation with the standard dosage at any time afterward. Results: Of 66 patients, 4 were excluded because of withdrawal of consent or screening failures. After 3 months the results in the standard arm were highly significantly superior compared with those in the low-dose arm (visual analogue scale, P=.001; Calcaneodynia score, P=.027; SF12, P=.045). The accrual of patients was stopped at this point. Further evaluation after 12 months' follow-up showed the following results: (1) highly significant fewer patients were reirradiated in the standard arm compared with the low-dose arm (P<.001); (2) the results of patients in the low-dose arm who were reirradiated were identical to those in the standard arm not reirradiated (reirradiation as a salvage therapy if the lower dose was ineffective); (3) patients experiencing a favorable result after 3 months showed this even after 12 months, and some results even improved further between 3 and 12 months. Conclusions: This study confirms the superior analgesic effect of radiation therapy with 6-Gy doses on painful heel spur even for a longer time period of at least 1 year.

  12. Phylogeography of the Indo-West Pacific maskrays (Dasyatidae, Neotrygon): a complex example of chondrichthyan radiation in the Cenozoic.

    PubMed

    Puckridge, Melody; Last, Peter R; White, William T; Andreakis, Nikos

    2013-02-01

    Maskrays of the genus Neotrygon (Dasyatidae) have dispersed widely in the Indo-West Pacific being represented largely by an assemblage of narrow-ranging coastal endemics. Phylogenetic reconstruction methods reproduced nearly identical and statistically robust topologies supporting the monophyly of the genus Neotrygon within the family Dasyatidae, the genus Taeniura being consistently basal to Neotrygon, and Dasyatis being polyphyletic to the genera Taeniurops and Pteroplatytrygon. The Neotrygon kuhlii complex, once considered to be an assemblage of color variants of the same biological species, is the most derived and widely dispersed subgroup of the genus. Mitochondrial (COI, 16S) and nuclear (RAG1) phylogenies used in synergy with molecular dating identified paleoclimatic fluctuations responsible for periods of vicariance and dispersal promoting population fragmentation and speciation in Neotrygon. Signatures of population differentiation exist in N. ningalooensis and N. annotata, yet a large-scale geological event, such as the collision between the Australian and Eurasian Plates, coupled with subsequent sea-level falls, appears to have separated a once homogeneous population of the ancestral form of N. kuhlii into southern Indian Ocean and northern Pacific taxa some 4-16 million years ago. Repeated climatic oscillations, and the subsequent establishment of land and shallow sea connections within and between Australia and parts of the Indo-Malay Archipelago, have both promoted speciation and established zones of secondary contact within the Indian and Pacific Ocean basins.

  13. Phylogeography of the Indo-West Pacific maskrays (Dasyatidae, Neotrygon): a complex example of chondrichthyan radiation in the Cenozoic

    PubMed Central

    Puckridge, Melody; Last, Peter R; White, William T; Andreakis, Nikos

    2013-01-01

    Maskrays of the genus Neotrygon (Dasyatidae) have dispersed widely in the Indo-West Pacific being represented largely by an assemblage of narrow-ranging coastal endemics. Phylogenetic reconstruction methods reproduced nearly identical and statistically robust topologies supporting the monophyly of the genus Neotrygon within the family Dasyatidae, the genus Taeniura being consistently basal to Neotrygon, and Dasyatis being polyphyletic to the genera Taeniurops and Pteroplatytrygon. The Neotrygon kuhlii complex, once considered to be an assemblage of color variants of the same biological species, is the most derived and widely dispersed subgroup of the genus. Mitochondrial (COI, 16S) and nuclear (RAG1) phylogenies used in synergy with molecular dating identified paleoclimatic fluctuations responsible for periods of vicariance and dispersal promoting population fragmentation and speciation in Neotrygon. Signatures of population differentiation exist in N. ningalooensis and N. annotata, yet a large-scale geological event, such as the collision between the Australian and Eurasian Plates, coupled with subsequent sea-level falls, appears to have separated a once homogeneous population of the ancestral form of N. kuhlii into southern Indian Ocean and northern Pacific taxa some 4–16 million years ago. Repeated climatic oscillations, and the subsequent establishment of land and shallow sea connections within and between Australia and parts of the Indo-Malay Archipelago, have both promoted speciation and established zones of secondary contact within the Indian and Pacific Ocean basins. PMID:23467194

  14. Cytogenetic analysis of Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) with Xyp sex determination system using standard staining, C-bands, NOR and synaptonemal complex microspreading techniques.

    PubMed

    De Almeida, M C; Zacaro, A A; Cella, D M

    2000-01-01

    The mitotic and meiotic chromosomes of the beetles Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) were analysed using standard staining, C-banding and silver impregnation techniques. We determine the diploid and haploid chromosome numbers, the sex determination system and describe the chromosomal morphology, the C-banding pattern and the chromosome(s) bearing NORs (nucleolar organizer regions). Both species shown 2n = 20 chromosomes, the chromosomal meioformula 9 + Xyp, and regular chromosome segregation during anaphases I and II. The chromosomes of E. atomaria are basically metacentric or submetacentric and P. dermestoides chromosomes are submetacentric or subtelocentric. In both beetles the constitutive heterochromatin is located in the pericentromeric region in all autosomes and in the Xp chromosome; additional C-bands were observed in telomeric region of the short arm in some autosomes in P. dermestoides. The yp chromosome did not show typical C-bands in these species. As for the synaptonemal complex, the nucleolar material is associated to the 7th bivalent in E. atomaria and 3rd and 7th bivalents in P. dermestoides. Strong silver impregnated material was observed in association with Xyp in light and electron microscopy preparations in these species and this material was interpreted to be related to nucleolar material.

  15. Cytogenetic analysis of Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) with Xyp sex determination system using standard staining, C-bands, NOR and synaptonemal complex microspreading techniques.

    PubMed

    De Almeida, M C; Zacaro, A A; Cella, D M

    2000-01-01

    The mitotic and meiotic chromosomes of the beetles Epicauta atomaria (Meloidae) and Palembus dermestoides (Tenebrionidae) were analysed using standard staining, C-banding and silver impregnation techniques. We determine the diploid and haploid chromosome numbers, the sex determination system and describe the chromosomal morphology, the C-banding pattern and the chromosome(s) bearing NORs (nucleolar organizer regions). Both species shown 2n = 20 chromosomes, the chromosomal meioformula 9 + Xyp, and regular chromosome segregation during anaphases I and II. The chromosomes of E. atomaria are basically metacentric or submetacentric and P. dermestoides chromosomes are submetacentric or subtelocentric. In both beetles the constitutive heterochromatin is located in the pericentromeric region in all autosomes and in the Xp chromosome; additional C-bands were observed in telomeric region of the short arm in some autosomes in P. dermestoides. The yp chromosome did not show typical C-bands in these species. As for the synaptonemal complex, the nucleolar material is associated to the 7th bivalent in E. atomaria and 3rd and 7th bivalents in P. dermestoides. Strong silver impregnated material was observed in association with Xyp in light and electron microscopy preparations in these species and this material was interpreted to be related to nucleolar material. PMID:11338427

  16. [An experimental study of a microbiological index in the complex setting of standards for lead, copper and zinc in the soil].

    PubMed

    Balabanov, Ts; Chipilska, L

    1997-01-01

    Anthropological pollutions falling in the soil by different routes evolve multitude unfavourable consequences for human being and health. The present publication considers a laboratory survey on the influence of lead, copper and zinc by their combined presence in soil onto soil autocleaning ability. The results from the experiments will serve the goals of complex hygiene standards of these three soil pollutants. A number of micro-organisms, relating to soil as an ecological compartment, are tested by two hygienic microbiological methods. The results from experiments point out as maximum permissible concentration (MPC) the following combination of concentrations within the range of the microbiological index: lead--54 mg/kg, copper--90 mg/kg, zinc--165 mg/kg. Concentrations over the above-mentioned have an oppressive effect on saprophytic microflora in higher rate than the observed impact of pathogenic micro-organisms. In conditions of MPC higher than the reached ones the autocleaning ability of the soil is threatened and thus a basis with unfavourable epidemiological indicators is established.

  17. Clinical quality standards for radiotherapy

    PubMed Central

    2012-01-01

    Aim of the study The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author. Material and methods In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy. Results As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 – organizational standards; 2 – physico-technical standards and 3 – clinical standards. Conclusion Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:23788854

  18. Effect of Brain Stem and Dorsal Vagus Complex Dosimetry on Nausea and Vomiting in Head and Neck Intensity-Modulated Radiation Therapy

    SciTech Connect

    Ciura, Katherine; McBurney, Michelle; Nguyen, Baongoc; Pham, Mary; Rebueno, Neal; Fuller, Clifton D.; Guha-Thakurta, Nandita; Rosenthal, David I.

    2011-04-01

    Intensity-modulated radiation therapy (IMRT) is becoming the treatment of choice for many head and neck cancer patients. IMRT reduces some toxicities by reducing radiation dose to uninvolved normal tissue near tumor targets; however, other tissues not irradiated using previous 3D techniques may receive clinically significant doses, causing undesirable side effects including nausea and vomiting (NV). Irradiation of the brainstem, and more specifically, the area postrema and dorsal vagal complex (DVC), has been linked to NV. We previously reported preliminary hypothesis-generating dose effects associated with NV in IMRT patients. The goal of this study is to relate brainstem dose to NV symptoms. We retrospectively studied 100 consecutive patients that were treated for oropharyngeal cancer with IMRT. We contoured the brainstem, area postrema, and DVC with the assistance of an expert diagnostic neuroradiologist. We correlated dosimetry for the 3 areas contoured with weekly NV rates during IMRT. NV rates were significantly higher for patients who received concurrent chemotherapy. Post hoc analysis demonstrated that chemoradiation cases exhibited a trend towards the same dose-response relationship with both brainstem mean dose (p = 0.0025) and area postrema mean dose (p = 0.004); however, both failed to meet statistical significance at the p {<=} 0.002 level. Duration of toxicity was also greater for chemoradiation patients, who averaged 3.3 weeks with reported Common Terminology Criteria for Adverse Events (CTC-AE), compared with an average of 2 weeks for definitive RT patients (p = 0.002). For definitive RT cases, no dose-response trend could be ascertained. The mean brainstem dose emerged as a key parameter of interest; however, no one dose parameter (mean/median/EUD) best correlated with NV. This study does not address extraneous factors that would affect NV incidence, including the use of antiemetics, nor chemotherapy dose schedule specifics before and during RT. A

  19. Radiation Nanomedicine for EGFR-Positive Breast Cancer: Panitumumab-Modified Gold Nanoparticles Complexed to the β-Particle-Emitter, (177)Lu.

    PubMed

    Yook, Simmyung; Cai, Zhongli; Lu, Yijie; Winnik, Mitchell A; Pignol, Jean-Philippe; Reilly, Raymond M

    2015-11-01

    Our objective was to construct a novel radiation nanomedicine for treatment of breast cancer (BC) expressing epidermal growth factor receptors (EGFR), particularly triple-negative tumors (TNBC). Gold nanoparticles (AuNP; 30 nm) were modified with polyethylene glycol (PEG) chains (4 kDa) derivatized with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelators for complexing the β-emitter, (177)Lu and with PEG chains (5 kDa) linked to panitumumab for targeting BC cells expressing EGFR. The AuNP were further coated with PEG chains (2 kDa) to stabilize the particles to aggregation. The binding and internalization of EGFR-targeted AuNP ((177)Lu-T-AuNP) into BC cells was studied and compared to nontargeted (177)Lu-NT-AuNP. The cytotoxicity of (177)Lu-T-AuNP and (177)Lu-NT-AuNP was measured in clonogenic assays using BC cells with widely different EGFR densities: MDA-MB-468 (10(6) receptors/cell), MDA-MB-231 (10(5) receptors/cell), and MCF-7 cells (10(4) receptors/cell). Radiation absorbed doses to the cell nucleus of MDA-MB-468 cells were estimated based on subcellular distribution. Darkfield and fluorescence microscopy as well as radioligand binding assays revealed that (177)Lu-T-AuNP were specifically bound by BC cells dependent on their EGFR density whereas the binding and internalization of (177)Lu-NT-AuNP was significantly lower. The affinity of binding of (177)Lu-T-AuNP to MDA-MB-468 cells was reduced by 2-fold compared to (123)I-labeled panitumumab (KD = 1.3 ± 0.2 nM vs 0.7 ± 0.4 nM, respectively). The cytotoxicity of (177)Lu-T-AuNP was dependent on the amount of radioactivity incubated with BC cells, their EGFR density and the radiosensitivity of the cells. The clonogenic survival (CS) of MDA-MB-468 cells overexpressing EGFR was reduced to <0.001% at the highest amount of (177)Lu-T-AuNP tested (4.5 MBq; 6 × 10(11) AuNP per 2.5 × 10(4)-1.2 × 10(5) cells). (177)Lu-T-AuNP were less effective for killing MDA-MB-231 cells or MCF-7 cells with

  20. Radiation Nanomedicine for EGFR-Positive Breast Cancer: Panitumumab-Modified Gold Nanoparticles Complexed to the β-Particle-Emitter, (177)Lu.

    PubMed

    Yook, Simmyung; Cai, Zhongli; Lu, Yijie; Winnik, Mitchell A; Pignol, Jean-Philippe; Reilly, Raymond M

    2015-11-01

    Our objective was to construct a novel radiation nanomedicine for treatment of breast cancer (BC) expressing epidermal growth factor receptors (EGFR), particularly triple-negative tumors (TNBC). Gold nanoparticles (AuNP; 30 nm) were modified with polyethylene glycol (PEG) chains (4 kDa) derivatized with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelators for complexing the β-emitter, (177)Lu and with PEG chains (5 kDa) linked to panitumumab for targeting BC cells expressing EGFR. The AuNP were further coated with PEG chains (2 kDa) to stabilize the particles to aggregation. The binding and internalization of EGFR-targeted AuNP ((177)Lu-T-AuNP) into BC cells was studied and compared to nontargeted (177)Lu-NT-AuNP. The cytotoxicity of (177)Lu-T-AuNP and (177)Lu-NT-AuNP was measured in clonogenic assays using BC cells with widely different EGFR densities: MDA-MB-468 (10(6) receptors/cell), MDA-MB-231 (10(5) receptors/cell), and MCF-7 cells (10(4) receptors/cell). Radiation absorbed doses to the cell nucleus of MDA-MB-468 cells were estimated based on subcellular distribution. Darkfield and fluorescence microscopy as well as radioligand binding assays revealed that (177)Lu-T-AuNP were specifically bound by BC cells dependent on their EGFR density whereas the binding and internalization of (177)Lu-NT-AuNP was significantly lower. The affinity of binding of (177)Lu-T-AuNP to MDA-MB-468 cells was reduced by 2-fold compared to (123)I-labeled panitumumab (KD = 1.3 ± 0.2 nM vs 0.7 ± 0.4 nM, respectively). The cytotoxicity of (177)Lu-T-AuNP was dependent on the amount of radioactivity incubated with BC cells, their EGFR density and the radiosensitivity of the cells. The clonogenic survival (CS) of MDA-MB-468 cells overexpressing EGFR was reduced to <0.001% at the highest amount of (177)Lu-T-AuNP tested (4.5 MBq; 6 × 10(11) AuNP per 2.5 × 10(4)-1.2 × 10(5) cells). (177)Lu-T-AuNP were less effective for killing MDA-MB-231 cells or MCF-7 cells with

  1. 40 CFR 190.10 - Standards for normal operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROTECTION PROGRAMS ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR NUCLEAR POWER OPERATIONS Environmental Standards for the Uranium Fuel Cycle § 190.10 Standards for normal operations. Operations covered by...

  2. [{sup 18}F]FDG-PET Standard Uptake Value as a Metabolic Predictor of Bone Marrow Response to Radiation: Impact on Acute and Late Hematological Toxicity in Cervical Cancer Patients Treated With Chemoradiation Therapy

    SciTech Connect

    Elicin, Olgun; Callaway, Sharon; Prior, John O.; Bourhis, Jean; Ozsahin, Mahmut; Herrera, Fernanda G.

    2014-12-01

    Purpose: To quantify the relationship between bone marrow (BM) response to radiation and radiation dose by using {sup 18}F-labeled fluorodeoxyglucose positron emission tomography [{sup 18}F]FDG-PET standard uptake values (SUV) and to correlate these findings with hematological toxicity (HT) in cervical cancer (CC) patients treated with chemoradiation therapy (CRT). Methods and Materials: Seventeen women with a diagnosis of CC were treated with standard doses of CRT. All patients underwent pre- and post-therapy [{sup 18}F]FDG-PET/computed tomography (CT). Hemograms were obtained before and during treatment and 3 months after treatment and at last follow-up. Pelvic bone was autosegmented as total bone marrow (BM{sub TOT}). Active bone marrow (BM{sub ACT}) was contoured based on SUV greater than the mean SUV of BM{sub TOT}. The volumes (V) of each region receiving 10, 20, 30, and 40 Gy (V{sub 10}, V{sub 20}, V{sub 30}, and V{sub 40}, respectively) were calculated. Metabolic volume histograms and voxel SUV map response graphs were created. Relative changes in SUV before and after therapy were calculated by separating SUV voxels into radiation therapy dose ranges of 5 Gy. The relationships among SUV decrease, radiation dose, and HT were investigated using multiple regression models. Results: Mean relative pre-post-therapy SUV reductions in BM{sub TOT} and BM{sub ACT} were 27% and 38%, respectively. BM{sub ACT} volume was significantly reduced after treatment (from 651.5 to 231.6 cm{sup 3}, respectively; P<.0001). BM{sub ACT} V{sub 30} was significantly correlated with a reduction in BM{sub ACT} SUV (R{sup 2}, 0.14; P<.001). The reduction in BM{sub ACT} SUV significantly correlated with reduction in white blood cells (WBCs) at 3 months post-treatment (R{sup 2}, 0.27; P=.04) and at last follow-up (R{sup 2}, 0.25; P=.04). Different dosimetric parameters of BM{sub TOT} and BM{sub ACT} correlated with long-term hematological outcome. Conclusions: The volumes of BM

  3. Standards not that standard.

    PubMed

    Vilanova, Cristina; Tanner, Kristie; Dorado-Morales, Pedro; Villaescusa, Paula; Chugani, Divya; Frías, Alba; Segredo, Ernesto; Molero, Xavier; Fritschi, Marco; Morales, Lucas; Ramón, Daniel; Peña, Carlos; Peretó, Juli; Porcar, Manuel

    2015-01-01

    There is a general assent on the key role of standards in Synthetic Biology. In two consecutive letters to this journal, suggestions on the assembly methods for the Registry of standard biological parts have been described. We fully agree with those authors on the need of a more flexible building strategy and we highlight in the present work two major functional challenges standardization efforts have to deal with: the need of both universal and orthogonal behaviors. We provide experimental data that clearly indicate that such engineering requirements should not be taken for granted in Synthetic Biology. PMID:26435739

  4. Report on Performance Standards in Mathematics and English: Results from the New Standards Project, Big Sky Scoring Conference. Project 2.3: Complex Performance Assessments: Expanding the Scope and Approaches to Assessment.

    ERIC Educational Resources Information Center

    Resnick, Lauren; And Others

    The New Standards Project (NSP) is an effort to create a state- and district-based assessment and professional development system to serve as a catalyst for major educational reform. As part of a professional development strategy tied to assessment, 114 teachers, curriculum supervisors, and assessment directors, representing 23 states and…

  5. ULTRA SECURE HIGH RELIABILITY WIRELESS RADIATION MONITOR

    SciTech Connect

    Cordaro, J.; Shull, D.; Farrar, M.; Reeves, G.

    2011-08-03

    Radiation monitoring in nuclear facilities is essential to safe operation of the equipment as well as protecting personnel. In specific, typical air monitoring of radioactive gases or particulate involves complex systems of valves, pumps, piping and electronics. The challenge is to measure a representative sample in areas that are radioactively contaminated. Running cables and piping to these locations is very expensive due to the containment requirements. Penetration into and out of an airborne or containment area is complex and costly. The process rooms are built with thick rebar-enforced concrete walls with glove box containment chambers inside. Figure 1 shows high temperature radiation resistance cabling entering the top of a typical glove box. In some case, the entire processing area must be contained in a 'hot cell' where the only access into the chamber is via manipulators. An example is shown in Figure 2. A short range wireless network provides an ideal communication link for transmitting the data from the radiation sensor to a 'clean area', or area absent of any radiation fields or radioactive contamination. Radiation monitoring systems that protect personnel and equipment must meet stringent codes and standards due to the consequences of failure. At first glance a wired system would seem more desirable. Concerns with wireless communication include latency, jamming, spoofing, man in the middle attacks, and hacking. The Department of Energy's Savannah River National Laboratory (SRNL) has developed a prototype wireless radiation air monitoring system that address many of the concerns with wireless and allows quick deployment in radiation and contamination areas. It is stand alone and only requires a standard 120 VAC, 60 Hz power source. It is designed to be mounted or portable. The wireless link uses a National Security Agency (NSA) Suite B compliant wireless network from Fortress Technologies that is considered robust enough to be used for classified data

  6. Standardized CT protocols and nomenclature: better, but not yet there.

    PubMed

    Singh, Sarabjeet; Kalra, Mannudeep K

    2014-10-01

    Radiation dose associated with CT is an important safety concern in patient care, especially in children. Technical advancements in multidetector-row CT scanner technology offer several advantages for clinical applications; these advancements have considerably increased CT utilization and enhanced the complexity of CT scanning protocols. Furthermore there are several scan manufacturers spearheading these technical advancements, leading to different commercial names causing confusion among the users, especially at imaging sites with scanners from different vendors. Several scientific studies and the National Council on Radiation Protection and Measurements (NCRP) have shown variation in CT radiation doses for same body region and similar scanning protocols. Therefore there is a need for standardization of scanning protocols and nomenclature of scan parameters. The following material reviews the status and challenges in standardization of CT scanning and nomenclature. PMID:25304702

  7. Phase II Study of the Addition of Bevacizumab to Standard Chemoradiation for Loco-regionally Advanced Nasopharyngeal Carcinoma: Radiation Therapy Oncology Group (RTOG) Trial 0615

    PubMed Central

    Lee, Nancy Y.; Zhang, Ed; Pfister, David. G.; Kim, John; Garden, Adam. S.; Mechalakos, James; Hu, Kenneth; Le, Quynh T.; Colevas, A. Dimitrios; Glisson, Bonnie S.; Chan, Anthony T.C.; Ang, K. Kian

    2016-01-01

    Purpose We sought to improve the outcomes for loco-regionally advanced nasopharyngeal carcinoma (NPC) by testing the feasibility/safety of adding bevacizumab to chemoradiation. Patients/Methods Eligible patients with ≥T2b and/or positive node(s) were prescribed 3 cycles of bevacizumab (15 mg/kg) and cisplatin (100 mg/m2) both given on days 1, 22, and 43 of radiation (70 Gy) using IMRT delivered over 33 days on a daily basis, Monday through Friday. This is followed by 3 cycles of bevacizumab (15 mg/kg), cisplatin (80 mg/m2) both were given on days 64, 85, and 106 and fluorouracil (1000 mg/m2/d) on days 64–67, 85–88, 106–109 after radiation. The primary endpoint was to evaluate the safety of the addition of bevacizumab to chemoradiation, specifically looking at treatment-related Grade 4 hemorrhage and/or any Grade 5 adverse event in the first year. Toxicity during and after treatment were collected along with tumor control endpoints. The analysis was done per protocol. This protocol has completed its target accrual. Results There were a total of 46 patients enrolled in this study of whom 44 patients were eligible for analysis. No grade 3–4 hemorrhage or grade 5 adverse events were observed; 9 patients (20.5%) experienced grade 1–2 hemorrhage. Grade 4 adverse events were experienced by the following numbers of patients: leukopenia NOS – 6; lymphopenia – 5; neutrophil count – 5; pharyngolaryngeal pain – 2; hemoglobin – 1; infection with grade 3–4 neutrophils (blood) – 1; infection with grade 3–4 neutrophils [skin (cellulitis)] – 1; tinnitus – 1; thrombosis – 1; radiation mucositis – 1. The most common grade 3 adverse events were radiation mucositis – 33; dysphagia – 25; and mucositis/stomatitis (clinical exam) (pharynx) – 15. Two patients experienced late grade 3 xerostomia. Other late grade 3 adverse events were: dysphagia – 5; hearing impaired – 3; neuralgia NOS – 2; constitutional symptoms (other) – 1; dehydration

  8. Topical Hyaluronic Acid vs. Standard of Care for the Prevention of Radiation Dermatitis After Adjuvant Radiotherapy for Breast Cancer: Single-Blind Randomized Phase III Clinical Trial

    SciTech Connect

    Pinnix, Chelsea; Perkins, George H.; Strom, Eric A.; Tereffe, Welela; Woodward, Wendy; Oh, Julia L.; Arriaga, Lisa; Munsell, Mark F.; Kelly, Patrick; Hoffman, Karen E.; Smith, Benjamin D.; Buchholz, Thomas A.; Yu, T. Kuan

    2012-07-15

    Purpose: To determine the efficacy of an emulsion containing hyaluronic acid to reduce the development of {>=}Grade 2 radiation dermatitis after adjuvant breast radiation compared with best supportive care. Methods and Materials: Women with breast cancer who had undergone lumpectomy and were to receive whole-breast radiotherapy to 50 Gy with a 10- to 16-Gy surgical bed boost were enrolled in a prospective randomized trial to compare the effectiveness of a hyaluronic acid-based gel (RadiaPlex) and a petrolatum-based gel (Aquaphor) for preventing the development of dermatitis. Each patient was randomly assigned to use hyaluronic acid gel on the medial half or the lateral half of the irradiated breast and to use the control gel on the other half. Dermatitis was graded weekly according to the Common Terminology Criteria v3.0 by the treating physician, who was blinded as to which gel was used on which area of the breast. The primary endpoint was development of {>=}Grade 2 dermatitis. Results: The study closed early on the basis of a recommendation from the Data and Safety Monitoring Board after 74 of the planned 92 patients were enrolled. Breast skin treated with the hyaluronic acid gel developed a significantly higher rate of {>=}Grade 2 dermatitis than did skin treated with petrolatum gel: 61.5% (40/65) vs. 47.7% (31/65) (p = 0.027). Only 1ne patient developed Grade 3 dermatitis using either gel. A higher proportion of patients had worse dermatitis in the breast segment treated with hyaluronic acid gel than in that treated with petrolatum gel at the end of radiotherapy (42% vs. 14%, p = 0.003). Conclusion: We found no benefit from the use of a topical hyaluronic acid-based gel for reducing the development of {>=}Grade 2 dermatitis after adjuvant radiotherapy for breast cancer. Additional studies are needed to determine the efficacy of hyaluronic acid-based gel in controlling radiation dermatitis symptoms after they develop.

  9. Complexation of Optoelectronic Systems

    NASA Astrophysics Data System (ADS)

    Boreisho, A. S.; Il‧in, M. Yu.; Konyaev, M. A.; Mikhailenko, A. S.; Morozov, A. V.; Strakhov, S. Yu.

    2016-05-01

    Problems of increasing the efficiency and the functionality of complex optoelectronic systems for monitoring real atmospheric conditions and of their use are discussed. It is shown by the example of a meteorological complex comprising an infrared wind-sensing lidar and an X-range Doppler radar that the complexation of probing systems working in different electromagnetic-radiation ranges opens up new opportunities for determining the meteorological parameters of a turbulent atmosphere and investigating the interaction of radiation with it.

  10. Consumption of the Soluble Dietary Fibre Complex PolyGlycopleX® Reduces Glycaemia and Increases Satiety of a Standard Meal Postprandially

    PubMed Central

    Solah, Vicky A.; O’Mara-Wallace, Babette; Meng, Xingqiong; Gahler, Roland J.; Kerr, Deborah A.; James, Anthony P.; Fenton, Haelee K.; Johnson, Stuart K.; Wood, Simon

    2016-01-01

    The effect of consumption of PolyGlycopleX® (PGX®) was compared to wheat dextrin (WD) in combination with a standard meal, on postprandial satiety and glycaemia in a double-blind, randomised crossover trial, of 14 healthy subjects trained as a satiety panel. At each of six two-hour satiety sessions, subjects consumed one of three different test meals on two separate occasions. The test meals were: a standard meal plus 5 g PGX; a standard meal plus 4.5 g of PGX as softgels; and a standard meal plus 5 g of WD. Subjects recorded fullness using a labelled magnitude scale at 0, 15, 30, 45, 60, 90, and 120 min and the total area under the curve (AUC), mean fullness vs. time was calculated. The meals with PGX (in granular and softgel form) gave higher satiety (AUC) (477 ± 121 and 454 ± 242 cm·min), than the meal with WD (215 ± 261 cm·min) (p < 0.001). Subjects had blood glucose levels measured after the meals with PGX (granules) and WD. Glucose response (AUC) was significantly lower (p < 0.001) after the PGX meal than for the WD meal.  The high viscosity reported for PGX is a likely mechanism behind the significant satiety and blood glucose modulating effects observed in this study. PMID:27164135

  11. How Much Confidence Can We Have in EU-SILC? Complex Sample Designs and the Standard Error of the Europe 2020 Poverty Indicators

    ERIC Educational Resources Information Center

    Goedeme, Tim

    2013-01-01

    If estimates are based on samples, they should be accompanied by appropriate standard errors and confidence intervals. This is true for scientific research in general, and is even more important if estimates are used to inform and evaluate policy measures such as those aimed at attaining the Europe 2020 poverty reduction target. In this article I…

  12. Toward Reliable Industrial Radiation Thermometry

    NASA Astrophysics Data System (ADS)

    Yamada, Y.; Ishii, J.

    2015-08-01

    Application of radiation thermometry in industrial scenes is rapidly increasing with the widespread use of low-cost infrared thermometers and thermal imagers. However, their performances are not always up to the users' expectations. This is often due to lack of appropriate information on the limitations of the instrument performance and of radiation thermometry itself. In this article, these limitations are disclosed, namely the targeting capabilities of the thermometers including the size-of-source effect of thermal imagers, reflection errors, and unknown emissivity of the measurement object. Attempts made at the NMIJ are introduced, which aim at alleviating the effect of these difficulties. Two-color radiation thermometers have been neglected from the traceability chain and from standardization efforts due to their technical complexity. Recent activities to incorporate them effectively in the calibration chain and to establish international standards are presented. Calibration of low-cost thermometers with a fixed instrumental emissivity setting has been an issue for calibration laboratories. Simple apparatus that enables calibration of such instruments is described. Methods to compensate for unknown emissivities are presented utilizing auxiliary sources to realize a blackbody condition, which is applied to thermal imagers to overcome the problem of the size-of-source effect and reflection error at the same time. Extensions of the technique to objects with specular and scattering surfaces are described. Such efforts are encouraged in the thermometry community since they are essential in establishing an unbroken chain of traceability to the industrial front.

  13. KEY COMPARISON: Final report on APMP key comparison of local realization of ITS-90 above the silver point using radiation thermometers as transfer standards, APMP-T-K5-97

    NASA Astrophysics Data System (ADS)

    Sakuma, Fumihiro

    2010-01-01

    In key comparison APMP.T-K5, a radiation thermometer was used as a transfer standard for radiance temperature measurements at a blackbody radiation source or a standard lamp at nominal temperatures Tnom from 962 °C to 2800 °C. The transfer standard was hand-carried from the pilot laboratory, NMIJ (Japan), to a participant where it was compared with the participant's standard within the range from 962 °C to 2800 °C and was returned to the pilot laboratory. In the case of the blackbody comparison, a copper-point blackbody was carried along with the thermometer to ensure the thermometer stability. The pilot calibrated the thermometer before and after each transport. Seven institutes joined the comparison: KRISS, NIM, NMIA, NMIJ, A*STAR, KIM-LIPI and CMS/ITRI. Five institutes participated in both key comparisons CCT-K5 and APMP.T-K5, and among them four institutes acted as the linking laboratories: KRISS, NIM, NMIA and NMIJ. The linkage process is described in the Addendum of the APMP-T-K5 Final Report. The degree of equivalence of each laboratory with respect to the CCT-K5 key comparison reference value, TR, is given by a pair of terms: Di = (Ti - TR) and Ui, its expanded uncertainty (at 95% confidence level), both expressed in kelvin. This uncertainty includes the uncertainties in the original laboratory calibrations, the standard deviation of the average difference, the uncertainties of the key comparison reference values and of the link between the APMP and CCT key comparison from 962 °C to 1700 °C. From 1800 °C to 2800 °C the APMP reference value was determined from the average of the participating laboratories including the pilot. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition

  14. Phase function, backscatter, extinction, and absorption for standard radiation atmosphere and El Chichon aerosol models at visible and near-infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Suttles, J. T.; Lecroy, S. R.

    1985-01-01

    Tabular values of phase function, Legendre polynominal coefficients, 180 deg backscatter, and extinction cross section are given for eight wavelengths in the atmospheric windows between 0.4 and 2.2 microns. Also included are single scattering albedo, asymmetry factor, and refractive indices. These values are based on Mie theory calculations for the standard rediation atmospheres (continental, maritime, urban, unperturbed stratospheric, volcanic, upper atmospheric, soot, oceanic, dust, and water-soluble) assest measured volcanic aerosols at several time intervals following the El Chichon eruption. Comparisons of extinction to 180 deg backscatter for different aerosol models are presented and related to lidar data.

  15. Comparison of two treatment strategies for irradiation of regional lymph nodes in patients with breast cancer: Lymph flow guided portals versus standard radiation fields

    PubMed Central

    Novikov, Sergey Nikolaevich; Kanaev, Sergey Vasilevich; Semiglazov, Vladimir Fedorovich; Jukova, Ludmila Alekseevna; Krzhivitckiy, Pavel Ivanovich

    2014-01-01

    Aim and Background Radiotherapy being an essential part of breast cancer treatment, we evaluate various radiotherapy strategies in patients with breast cancer. Materials and methods Lymph node (LN) scintigraphy was performed in 172 primary patients with BC. LN visualization started 30–360 min after intratumoral injection of 75–150 MBq of 99mTc-nanocolloids. Our standard recommendation for postoperative radiotherapy in patients with LN invasion by BC were as follows: for patients with external localization of tumour – breast + axillary (Ax) + sub-supraclavicular (SSCL) regions; with internal localization – all above + internal mammary nodes (IM). Proposed strategy of lymph flow guided radiotherapy is based on the assumption that only regions that contain ‘hot’ LNs must be included in a treatment volume. Results Among 110 patients with external localization of BC, Ax LNs were visualized in all cases and in 62 patients it was the only region with ‘hot’ LN. Twenty-three patients (20.9%) had drainage to Ax + SSCL, 12 (10.9%) – Ax + IM, 13 (11.8%) – Ax + SSCL + IM regions. After the visualization of lymph flow patterns, standard treatment volume was changed in 87/110 cases (79.1%): in 56.4%, reduced, in 22.7%, enlarged or changed. In 62 patients with tumours in internal quadrants, we revealed the following patterns of lymph-flow: only to the Ax region in 23 (37.1%); Ax + IM, 13 (21%); Ax + SSCL, 15 (24.2%); Ax + IM + ISSCL, 11 (17.7%) cases. After lymph-flow visualization, the standard irradiation volume was reduced in 53/62 (85.5%) cases. Conclusion Visualization of an individual lymph flow pattern from BC can be used for the optimization of standard fields used for irradiation of regional LNs. PMID:25535581

  16. Microwave Radiation Detector

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.

    1984-01-01

    Direct photon detector responds to microwave frequencies. Method based on trapped-ion frequency-generation standards proposed to detect radio-frequency (RF) radiation at 40.5 GHz. Technique used for directdetection (RF) communication, radar, and radio astronomy.

  17. Standards in Mathematics Teaching.

    ERIC Educational Resources Information Center

    Brookes, Bill

    1978-01-01

    This article is based on a lecture given at the 1978 Easter Course at Padgate College of Higher Education. The lecture is an analysis of the complexity of mathematics teaching and the setting of teaching standards. (MN)

  18. Radiation treatment of pharmaceuticals

    NASA Astrophysics Data System (ADS)

    Dám, A. M.; Gazsó, L. G.; Kaewpila, S.; Maschek, I.

    1996-03-01

    Product specific doses were calculated for pharmaceuticals to be radiation treated. Radio-pasteurization dose were determined for some heat sensitive pharmaceutical basic materials (pancreaton, neopancreatin, neopancreatin USP, duodenum extract). Using the new recommendation (ISO standards, Method 1) dose calculations were performed and radiation sterilization doses were determined for aprotinine and heparine Na.

  19. Effects of Complex Interplanetary Structures on the Dynamics of the Earth's Outer Radiation Belt During the 16-30 September 2014 Period: II) Corotating Solar Wind Stream

    NASA Astrophysics Data System (ADS)

    Souza, V. M. C. E. S.; Da Silva, L. A.; Sibeck, D. G.; Alves, L. R.; Jauer, P. R.; Dias Silveira, M. V.; Medeiros, C.; Marchezi, J.; Rockenbach, M.; Baker, D. N.; Kletzing, C.; Kanekal, S. G.; Georgiou, M.; Mendes, O., Jr.; Dal Lago, A.; Vieira, L. E. A.

    2015-12-01

    We present a case study describing the dynamics of the outer radiation belt for two different solar wind conditions. First, we discuss a dropout of outer belt energetic electron fluxes corresponding to the arrival of an interplanetary coronal mass ejection (ICME) followed by a corotating stream in September 2014. Second, we discuss the reformation of the outer radiation belt that began on September 22nd. We find that the arrival of the ICME and the corotating interaction region that preceded the stream cause a long-duration (many day) dropout of high-energy electrons. The recovery in radiation belt fluxes only begins when the high-speed stream begins to develop IMF Bz fluctuations and auroral activity resumes. Furthermore, during periods in which several consecutive solar wind structures appear, the first structure primes the outer radiation belt prior to the interaction of the subsequent solar wind structures with the magnetosphere. Consequently, the evolution of the outer radiation belt through the solar cycle is significantly affected by the dominant structure of each phase of the cycle. We use energetic electron and magnetic field observations provided by the Van Allen Probes, THEMIS, and GOES missions.

  20. Shortwave Radiation

    NASA Technical Reports Server (NTRS)

    Klassen, Steve; Bugbee, Bruce

    2005-01-01

    Accurate shortwave radiation data is critical to evapotranspiration (ET) models used for developing irrigation schedules to optimize crop production while saving water, minimizing fertilizer, herbicide, and pesticide applications, reducing soil erosion, and protecting surface and ground water quality. Low cost silicon cell pyranometers have proven to be sufficiently accurate and robust for widespread use in agricultural applications under unobstructed daylight conditions. More expensive thermopile pyranometers are required for use as calibration standards and measurements under light with unique spectral properties (electric lights, under vegetation, in greenhouses and growth chambers). Routine cleaning, leveling, and annual calibration checks will help to ensure the integrity of long-term data.

  1. Radiation health research, 1986 - 1990

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A collection of 225 abstracts of radiation research sponsored by NASA during the period 1986 through 1990 is reported. Each abstract was categorized within one of four discipline areas: physics, biology, risk assessment, and microgravity. Topic areas within each discipline were assigned as follows: Physics - atomic physics, nuclear science, space radiation, radiation transport and shielding, and instrumentation; Biology - molecular biology, cellular radiation biology, tissue, organs and organisms, radioprotectants, and plants; Risk assessment - radiation health and epidemiology, space flight radiation health physics, inter- and intraspecies extrapolation, and radiation limits and standards; and Microgravity. When applicable subareas were assigned for selected topic areas. Keywords and author indices are provided.

  2. Intensity-Modulated Radiotherapy Reduces Radiation-Induced Morbidity and Improves Health-Related Quality of Life: Results of a Nonrandomized Prospective Study Using a Standardized Follow-Up Program

    SciTech Connect

    Vergeer, Marije R. Doornaert, Patricia A.H.; Rietveld, Derek H.F.; Leemans, C. Rene; Langendijk, Johannes A.

    2009-05-01

    Purpose: The purpose of this study was to compare intensity-modulated radiation therapy (IMRT) and three-dimensional conventional radiotherapy (3D-CRT) with regard to patient-rated xerostomia, Radiation Therapy Oncology Group (RTOG) acute and late xerostomia and health-related quality of life (HRQoL) among patients with head and neck squamous cell carcinoma (HNSCC). Methods and Materials: Included were 241 patients with HNSCC treated with bilateral irradiation {+-} chemotherapy. Since 2000, all patients treated with HNSCC were included in a program, which prospectively assessed acute and late morbidity according to the RTOG and HRQoL on a routine basis at regular intervals. Before October 2004, all patients were treated with 3D-CRT (N = 150). After clinical implementation in October 2004, 91 patients received IMRT. In this study, the differences regarding RTOG toxicity, xerostomia, and other items of HRQoL were analyzed. Results: The use of IMRT resulted in a significant reduction of the mean dose of the parotid glands (27 Gy vs. 43 Gy (p < 0.001). During radiation, Grade 2 RTOG xerostomia was significantly less with IMRT than with 3D-CRT. At 6 months, the prevalence of patient-rated moderate to severe xerostomia and Grade 2 or higher RTOG xerostomia was significantly lower after IMRT versus 3D-CRT. Treatment with IMRT also had a positive effect on several general and head and neck cancer-specific HRQoL dimensions. Conclusions: IMRT results in a significant reduction of patient- and observer-rated xerostomia, as well as other head and neck symptoms, compared with standard 3D-CRT. These differences translate into a significant improvement of the more general dimensions of HRQoL.

  3. Mitotic regulator Nlp interacts with XPA/ERCC1 complexes and regulates nucleotide excision repair (NER) in response to UV radiation.

    PubMed

    Ma, Xiao-Juan; Shang, Li; Zhang, Wei-Min; Wang, Ming-Rong; Zhan, Qi-Min

    2016-04-10

    Cellular response to DNA damage, including ionizing radiation (IR) and UV radiation, is critical for the maintenance of genomic fidelity. Defects of DNA repair often result in genomic instability and malignant cell transformation. Centrosomal protein Nlp (ninein-like protein) has been characterized as an important cell cycle regulator that is required for proper mitotic progression. In this study, we demonstrate that Nlp is able to improve nucleotide excision repair (NER) activity and protects cells against UV radiation. Upon exposure of cells to UVC, Nlp is translocated into the nucleus. The C-terminus (1030-1382) of Nlp is necessary and sufficient for its nuclear import. Upon UVC radiation, Nlp interacts with XPA and ERCC1, and enhances their association. Interestingly, down-regulated expression of Nlp is found to be associated with human skin cancers, indicating that dysregulated Nlp might be related to the development of human skin cancers. Taken together, this study identifies mitotic protein Nlp as a new and important member of NER pathway and thus provides novel insights into understanding of regulatory machinery involved in NER.

  4. Mitotic regulator Nlp interacts with XPA/ERCC1 complexes and regulates nucleotide excision repair (NER) in response to UV radiation.

    PubMed

    Ma, Xiao-Juan; Shang, Li; Zhang, Wei-Min; Wang, Ming-Rong; Zhan, Qi-Min

    2016-04-10

    Cellular response to DNA damage, including ionizing radiation (IR) and UV radiation, is critical for the maintenance of genomic fidelity. Defects of DNA repair often result in genomic instability and malignant cell transformation. Centrosomal protein Nlp (ninein-like protein) has been characterized as an important cell cycle regulator that is required for proper mitotic progression. In this study, we demonstrate that Nlp is able to improve nucleotide excision repair (NER) activity and protects cells against UV radiation. Upon exposure of cells to UVC, Nlp is translocated into the nucleus. The C-terminus (1030-1382) of Nlp is necessary and sufficient for its nuclear import. Upon UVC radiation, Nlp interacts with XPA and ERCC1, and enhances their association. Interestingly, down-regulated expression of Nlp is found to be associated with human skin cancers, indicating that dysregulated Nlp might be related to the development of human skin cancers. Taken together, this study identifies mitotic protein Nlp as a new and important member of NER pathway and thus provides novel insights into understanding of regulatory machinery involved in NER. PMID:26805762

  5. Radiation enteritis

    MedlinePlus

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  6. A modified Wright-Fisher model that incorporates Ne: A variant of the standard model with increased biological realism and reduced computational complexity.

    PubMed

    Zhao, Lei; Gossmann, Toni I; Waxman, David

    2016-03-21

    The Wright-Fisher model is an important model in evolutionary biology and population genetics. It has been applied in numerous analyses of finite populations with discrete generations. It is recognised that real populations can behave, in some key aspects, as though their size that is not the census size, N, but rather a smaller size, namely the effective population size, Ne. However, in the Wright-Fisher model, there is no distinction between the effective and census population sizes. Equivalently, we can say that in this model, Ne coincides with N. The Wright-Fisher model therefore lacks an important aspect of biological realism. Here, we present a method that allows Ne to be directly incorporated into the Wright-Fisher model. The modified model involves matrices whose size is determined by Ne. Thus apart from increased biological realism, the modified model also has reduced computational complexity, particularly so when Ne⪡N. For complex problems, it may be hard or impossible to numerically analyse the most commonly-used approximation of the Wright-Fisher model that incorporates Ne, namely the diffusion approximation. An alternative approach is simulation. However, the simulations need to be sufficiently detailed that they yield an effective size that is different to the census size. Simulations may also be time consuming and have attendant statistical errors. The method presented in this work may then be the only alternative to simulations, when Ne differs from N. We illustrate the straightforward application of the method to some problems involving allele fixation and the determination of the equilibrium site frequency spectrum. We then apply the method to the problem of fixation when three alleles are segregating in a population. This latter problem is significantly more complex than a two allele problem and since the diffusion equation cannot be numerically solved, the only other way Ne can be incorporated into the analysis is by simulation. We have

  7. Video Display Terminals: Radiation Issues.

    ERIC Educational Resources Information Center

    Murray, William E.

    1985-01-01

    Discusses information gathered in past few years related to health effects of video display terminals (VDTs) with particular emphasis given to issues raised by VDT users. Topics covered include radiation emissions, health concerns, radiation surveys, occupational radiation exposure standards, and long-term risks. (17 references) (EJS)

  8. A standardized set of 260 pictures for Turkish: norms of name and image agreement, age of acquisition, visual complexity, and conceptual familiarity.

    PubMed

    Raman, Ilhan; Raman, Evren; Mertan, Biran

    2014-06-01

    In the present study, normative data in Turkish are presented for the 260 color versions of the original Snodgrass and Vanderwart (1980) picture set for the first time. Norms are reported for name and image agreement, age of acquisition (AoA), visual complexity, and conceptual familiarity, together with written word frequency, and numbers of letters and syllables. We collected data from 277 native Turkish adults in a variety of tasks. The results indicated that, whilst several measures displayed language-specific variation, we also reported what seem to be language-independent-that is, universal-measures that show a systematic relationship across several languages. The implications of the reported measures in the domain of psycholinguistic research in Turkish and for wider cross-linguistic comparisons are discussed.

  9. A standardized set of 260 pictures for Turkish: norms of name and image agreement, age of acquisition, visual complexity, and conceptual familiarity.

    PubMed

    Raman, Ilhan; Raman, Evren; Mertan, Biran

    2014-06-01

    In the present study, normative data in Turkish are presented for the 260 color versions of the original Snodgrass and Vanderwart (1980) picture set for the first time. Norms are reported for name and image agreement, age of acquisition (AoA), visual complexity, and conceptual familiarity, together with written word frequency, and numbers of letters and syllables. We collected data from 277 native Turkish adults in a variety of tasks. The results indicated that, whilst several measures displayed language-specific variation, we also reported what seem to be language-independent-that is, universal-measures that show a systematic relationship across several languages. The implications of the reported measures in the domain of psycholinguistic research in Turkish and for wider cross-linguistic comparisons are discussed. PMID:23943583

  10. Energetic neutron and gamma-ray spectra under the earth radiation belts according to "SALYUT-7" [correction of "SALUTE-7"]-"KOSMOS-1686" orbital complex and "CORONAS-I" satellite data.

    PubMed

    Bogomolov, A V; Dmitriev, A V; Myagkova, I N; Ryumin, S P; Smirnova, O N; Sobolevsky, I M

    1998-01-01

    The spectra of neutrons >10 MeV and gamma-rays 1.5-100 MeV under the Earth Radiation Belts, restored from the data, obtained onboard orbital complex "SALYUT-7" [correction of "SALUTE-7"]-"KOSMOS-1686", are presented. The spectra shapes are similar to those for albedo neutrons and gamma-rays, but absolute values of their fluxes (0.2 cm-2 s-1 for neutrons, 0.8 cm-2 s-1 for gamma-rays at the equator and 1.2 cm-2 s-1, 1.9 cm-2 s-1, accordingly, at L=1.9) are several times as large. It is possibly explained by the fact that most of the detected particles were produced by the cosmic ray interactions with the orbital complex matter. Neutron and gamma-ray fluxes obtained from "CORONAS-1" data are near those for albedo particles. PMID:11542904

  11. Energetic neutron and gamma-ray spectra under the earth radiation belts according to "SALYUT-7" [correction of "SALUTE-7"]-"KOSMOS-1686" orbital complex and "CORONAS-I" satellite data.

    PubMed

    Bogomolov, A V; Dmitriev, A V; Myagkova, I N; Ryumin, S P; Smirnova, O N; Sobolevsky, I M

    1998-01-01

    The spectra of neutrons >10 MeV and gamma-rays 1.5-100 MeV under the Earth Radiation Belts, restored from the data, obtained onboard orbital complex "SALYUT-7" [correction of "SALUTE-7"]-"KOSMOS-1686", are presented. The spectra shapes are similar to those for albedo neutrons and gamma-rays, but absolute values of their fluxes (0.2 cm-2 s-1 for neutrons, 0.8 cm-2 s-1 for gamma-rays at the equator and 1.2 cm-2 s-1, 1.9 cm-2 s-1, accordingly, at L=1.9) are several times as large. It is possibly explained by the fact that most of the detected particles were produced by the cosmic ray interactions with the orbital complex matter. Neutron and gamma-ray fluxes obtained from "CORONAS-1" data are near those for albedo particles.

  12. Determination of complex permittivity from propagation constant measurement with planar transmission lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new two-standard calibration procedure is outlined for determining the complex permittivity of materials from the propagation constant measured with planar transmission lines. Once calibrated, a closed-form expression for the material permittivity is obtained. The effects of radiation and conducto...

  13. Tests of Exoplanet Atmospheric Radiative Transfer Codes

    NASA Astrophysics Data System (ADS)

    Harrington, Joseph; Challener, Ryan; DeLarme, Emerson; Cubillos, Patricio; Blecic, Jasmina; Foster, Austin; Garland, Justin

    2016-10-01

    Atmospheric radiative transfer codes are used both to predict planetary spectra and in retrieval algorithms to interpret data. Observational plans, theoretical models, and scientific results thus depend on the correctness of these calculations. Yet, the calculations are complex and the codes implementing them are often written without modern software-verification techniques. In the process of writing our own code, we became aware of several others with artifacts of unknown origin and even outright errors in their spectra. We present a series of tests to verify atmospheric radiative-transfer codes. These include: simple, single-line line lists that, when combined with delta-function abundance profiles, should produce a broadened line that can be verified easily; isothermal atmospheres that should produce analytically-verifiable blackbody spectra at the input temperatures; and model atmospheres with a range of complexities that can be compared to the output of other codes. We apply the tests to our own code, Bayesian Atmospheric Radiative Transfer (BART) and to several other codes. The test suite is open-source software. We propose this test suite as a standard for verifying current and future radiative transfer codes, analogous to the Held-Suarez test for general circulation models. This work was supported by NASA Planetary Atmospheres grant NX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

  14. [Radiation protection agents to provide the radiation safety of astronauts].

    PubMed

    Ushakov, I B; Ivanov, A A

    2013-01-01

    Taking into consideration the complexity of radiation factors and stressogenic factors of non-radiation nature in cosmic flights and prognostic difficulties of radiation situation, the authors propose to distinguish several stages of pharmacological protection for cosmonauts. The preparatory stage is realized on the Earth. The next stage is monitoring and correction of radioresistance during a flight. A possible stage consists of treatment of the radiation damage using a traditional protocol. The permanent stage includes pharmacological prevention of the distant consequences of irradiation.

  15. Estimates of cosmic radiation exposure on Tunisian passenger aircraft.

    PubMed

    Zarrouk, Neïla; Bennaceur, Raouf

    2008-01-01

    Radiation field produced by cosmic radiations in the earth's atmosphere is very complex and is significantly different from that found in the nuclear industry and other environments at ground level. Aircraft crew and frequent flyers are exposed to high levels of cosmic radiations of galactic and solar origin and to secondary radiation produced in the atmosphere. Following recommendations of the International Commission on Radiological Protection in publication 60, the European Union introduced a revised Basic Safety Standard Directive, which included exposure to natural sources of ionising radiations, including cosmic radiation, as occupational exposure. We computed the dose received by some Tunisian flights, using CARI-6, EPCARD, PCAIRE, and SIEVERT codes. Calculations performed during the year 2007, on mostly regular passenger flights of the Nouvelair Tunisian Company, indicate a mean effective dose rate ranging between 3 and 4 microSv/h. We give the general background and details, focusing on the situation in Tunisia with respect to radiation protection aspects of the cosmic radiation exposure. As far as we know, such a study has not previously been carried out.

  16. Practical Applications of Radioactivity and Nuclear Radiations

    NASA Astrophysics Data System (ADS)

    Lowenthal, Gerhart; Airey, Peter

    2005-09-01

    1. Atoms, nuclides and radionuclides; 2. Units and standards for radioactivity and radiation dosimetry and rules for radiation protection; 3. Properties of radiations emitted from radionuclides; 4. Nuclear radiations from a user's perspective; 5. Ionising radiation detectors; 6. Radioactivity and countrate measurements and the presentation of results; 7. Industrial applications of radioisotopes and radiation; 8. Application of tracer technology to industry and the environment; 9. Radionuclides to protect the environment.

  17. Practical Applications of Radioactivity and Nuclear Radiations

    NASA Astrophysics Data System (ADS)

    Lowenthal, Gerhart; Airey, Peter

    2001-08-01

    1. Atoms, nuclides and radionuclides; 2. Units and standards for radioactivity and radiation dosimetry and rules for radiation protection; 3. Properties of radiations emitted from radionuclides; 4. Nuclear radiations from a user's perspective; 5. Ionising radiation detectors; 6. Radioactivity and countrate measurements and the presentation of results; 7. Industrial applications of radioisotopes and radiation; 8. Application of tracer technology to industry and the environment; 9. Radionuclides to protect the environment.

  18. Evaluation of arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Nievergall, O.; Wendell, J.; Albee, R.

    2011-08-01

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  19. Evaluation of Arctic broadband surface radiation measurements

    NASA Astrophysics Data System (ADS)

    Matsui, N.; Long, C. N.; Augustine, J.; Halliwell, D.; Uttal, T.; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-02-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  20. Evaluation of Arctic Broadband Surface Radiation Measurements

    SciTech Connect

    Matsui, N.; Long, Charles N.; Augustine, J. A.; Halliwell, D.; Uttal, Taneil; Longenecker, D.; Niebergale, J.; Wendell, J.; Albee, R.

    2012-02-24

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that rotate sensors and shading devices that track the sun. High quality measurements require striking a balance between locating sensors in a pristine undisturbed location free of artificial blockage (such as buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data include solar tracker malfunctions, rime/frost/snow deposition on the instruments and operational problems due to limited operator access in extreme weather conditions. In this study, a comparison is made between the global and component sum (direct [vertical component] + diffuse) shortwave measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both shortwave and longwave measurements. Solutions to these operational problems are proposed that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols.

  1. Many-body radiative heat transfer theory.

    PubMed

    Ben-Abdallah, Philippe; Biehs, Svend-Age; Joulain, Karl

    2011-09-01

    In this Letter, an N-body theory for the radiative heat exchange in thermally nonequilibrated discrete systems of finite size objects is presented. We report strong exaltation effects of heat flux which can be explained only by taking into account the presence of many-body interactions. Our theory extends the standard Polder and van Hove stochastic formalism used to evaluate heat exchanges between two objects isolated from their environment to a collection of objects in mutual interaction. It gives a natural theoretical framework to investigate the photon heat transport properties of complex systems at the mesoscopic scale. PMID:22026672

  2. 40 CFR 191.03 - Standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Standards. 191.03 Section 191.03... ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL, HIGH-LEVEL AND TRANSURANIC RADIOACTIVE WASTES Environmental Standards for Management and Storage § 191.03 Standards....

  3. 40 CFR 191.04 - Alternative standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Alternative standards. 191.04 Section... PROGRAMS ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL....04 Alternative standards. (a) The Administrator may issue alternative standards from those...

  4. 40 CFR 191.04 - Alternative standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Alternative standards. 191.04 Section... PROGRAMS ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL....04 Alternative standards. (a) The Administrator may issue alternative standards from those...

  5. 14 CFR 25.1023 - Oil radiators.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Oil radiators. 25.1023 Section 25.1023... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1023 Oil radiators. (a) Each oil radiator... would be subjected in operation. (b) Each oil radiator air duct must be located so that, in case of...

  6. 14 CFR 25.1023 - Oil radiators.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil radiators. 25.1023 Section 25.1023... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1023 Oil radiators. (a) Each oil radiator... would be subjected in operation. (b) Each oil radiator air duct must be located so that, in case of...

  7. 14 CFR 25.1023 - Oil radiators.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil radiators. 25.1023 Section 25.1023... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1023 Oil radiators. (a) Each oil radiator... would be subjected in operation. (b) Each oil radiator air duct must be located so that, in case of...

  8. 14 CFR 25.1023 - Oil radiators.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil radiators. 25.1023 Section 25.1023... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1023 Oil radiators. (a) Each oil radiator... would be subjected in operation. (b) Each oil radiator air duct must be located so that, in case of...

  9. Infrastructure Standardization.

    ERIC Educational Resources Information Center

    Yow, Donna

    2002-01-01

    Describes the development of technological design standards for a 35-school construction/renovation effort by Guilford County Schools in North Carolina. The standards encompassed the physical infrastructure, telephone systems, and paging systems. (EV)

  10. Standardized Radiation Shield Design Methods: 2005 HZETRN

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Tripathi, Ram K.; Badavi, Francis F.; Cucinotta, Francis A.

    2006-01-01

    Research committed by the Langley Research Center through 1995 resulting in the HZETRN code provides the current basis for shield design methods according to NASA STD-3000 (2005). With this new prominence, the database, basic numerical procedures, and algorithms are being re-examined with new methods of verification and validation being implemented to capture a well defined algorithm for engineering design processes to be used in this early development phase of the Bush initiative. This process provides the methodology to transform the 1995 HZETRN research code into the 2005 HZETRN engineering code to be available for these early design processes. In this paper, we will review the basic derivations including new corrections to the codes to insure improved numerical stability and provide benchmarks for code verification.

  11. Radiation Therapy

    MedlinePlus

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  12. Radiation Therapy

    MedlinePlus

    ... people who have radiation therapy may feel more tired than usual, not feel hungry, or lose their ... of radiation therapy include: Fatigue. Fatigue, or feeling tired, is the most common side effect of radiation ...

  13. Radiation therapy

    MedlinePlus

    ... Because radiation is most harmful to quickly growing cells, radiation therapy damages cancer cells more than normal cells. ... cells from growing and dividing, and leads to cell death. Radiation therapy is used to fight many types of ...

  14. Performance Standards.

    ERIC Educational Resources Information Center

    Conley, David T.

    1997-01-01

    Standards-based systems generally require students to meet the performance level specified in order to proceed or be certified. This issue of the Oregon School Study Council (OSSC) Bulletin surveys the types of standards currently being proposed. After an introductory chapter, chapter 2 describes eight components of standards, illustrated with a…

  15. 40 CFR 191.03 - Standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Standards. 191.03 Section 191.03 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL, HIGH-LEVEL AND TRANSURANIC RADIOACTIVE WASTES...

  16. RADIATION DOSIMETER

    DOEpatents

    Balkwell, W.R. Jr.; Adams, G.D. Jr.

    1960-05-10

    An improvement was made in the determination of amounts of ionizing radiation, particularly low-energy beta particles of less than 1000 rad total dose by means of fluid-phase dosimeter employing a stabilized-- sensitized ferrous-ferric colorimetric system in a sulphuric acid medium. The improvement in the dosimeter consists of adding to the ferrous-ferric system in concentrations of 10/sub -2/ to 10/sup -4/M an organic compound having one or more carboxylic or equivalent groups, such compounds being capable of chelating or complexing the iron ions in the solution. Suitable sensitizing and stabilizing agents are benzoic, phthalic, salicylic, malonic, lactic, maleic, oxalic, citric, succinic, phenolic tartaric, acetic, and adipic acid, as well as other compounds which are added to the solution alone or in certain combinations. As in conventional fluid-phase dosimeters, the absorbed dosage is correlated with a corresponding change in optical density at particular wavelengths of the solution.

  17. Auditing radiation sterilization facilities

    NASA Astrophysics Data System (ADS)

    Beck, Jeffrey A.

    The diversity of radiation sterilization systems available today places renewed emphasis on the need for thorough Quality Assurance audits of these facilities. Evaluating compliance with Good Manufacturing Practices is an obvious requirement, but an effective audit must also evaluate installation and performance qualification programs (validation_, and process control and monitoring procedures in detail. The present paper describes general standards that radiation sterilization operations should meet in each of these key areas, and provides basic guidance for conducting QA audits of these facilities.

  18. Disentangling the complex evolutionary history of the Western Palearctic blue tits (Cyanistes spp.) - phylogenomic analyses suggest radiation by multiple colonization events and subsequent isolation.

    PubMed

    Stervander, Martin; Illera, Juan Carlos; Kvist, Laura; Barbosa, Pedro; Keehnen, Naomi P; Pruisscher, Peter; Bensch, Staffan; Hansson, Bengt

    2015-05-01

    Isolated islands and their often unique biota continue to play key roles for understanding the importance of drift, genetic variation and adaptation in the process of population differentiation and speciation. One island system that has inspired and intrigued evolutionary biologists is the blue tit complex (Cyanistes spp.) in Europe and Africa, in particular the complex evolutionary history of the multiple genetically distinct taxa of the Canary Islands. Understanding Afrocanarian colonization events is of particular importance because of recent unconventional suggestions that these island populations acted as source of the widespread population in mainland Africa. We investigated the relationship between mainland and island blue tits using a combination of Sanger sequencing at a population level (20 loci; 12 500 nucleotides) and next-generation sequencing of single population representatives (>3 200 000 nucleotides), analysed in coalescence and phylogenetic frameworks. We found (i) that Afrocanarian blue tits are monophyletic and represent four major clades, (ii) that the blue tit complex has a continental origin and that the Canary Islands were colonized three times, (iii) that all island populations have low genetic variation, indicating low long-term effective population sizes and (iv) that populations on La Palma and in Libya represent relicts of an ancestral North African population. Further, demographic reconstructions revealed (v) that the Canary Islands, conforming to traditional views, hold sink populations, which have not served as source for back colonization of the African mainland. Our study demonstrates the importance of complete taxon sampling and an extensive multimarker study design to obtain robust phylogeographical inferences.

  19. 40 CFR 197.25 - What standard must DOE meet?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Section 197.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS PUBLIC HEALTH AND ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR YUCCA MOUNTAIN, NEVADA Public Health and Environmental Standards for Disposal Human-Intrusion Standard § 197.25 What standard must...

  20. 40 CFR 197.25 - What standard must DOE meet?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Section 197.25 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS PUBLIC HEALTH AND ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR YUCCA MOUNTAIN, NEVADA Public Health and Environmental Standards for Disposal Human-Intrusion Standard § 197.25 What standard must...

  1. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. )

    1991-01-01

    Studies of atmospheric radiative processes are summarized for the period 1987-1990. Topics discussed include radiation modeling; clouds and radiation; radiative effects in dynamics and climate; radiation budget and aerosol effects; and gaseous absorption, particulate scattering and surface reflection. It is concluded that the key developments of the period are a defining of the radiative forcing to the climate system by trace gases and clouds, the recognition that cloud microphysics and morphology need to be incorporated not only into radiation models but also climate models, and the isolation of a few important unsolved theoretical problems in atmospheric radiation.

  2. Standard interface file handbook

    SciTech Connect

    Shapiro, A.; Huria, H.C. )

    1992-10-01

    This handbook documents many of the standard interface file formats that have been adopted by the US Department of Energy to facilitate communications between and portability of, various large reactor physics and radiation transport software packages. The emphasis is on those files needed for use of the VENTURE/PC diffusion-depletion code system. File structures, contents and some practical advice on use of the various files are provided.

  3. Disentangling the complex evolutionary history of the Western Palearctic blue tits (Cyanistes spp.) - phylogenomic analyses suggest radiation by multiple colonization events and subsequent isolation.

    PubMed

    Stervander, Martin; Illera, Juan Carlos; Kvist, Laura; Barbosa, Pedro; Keehnen, Naomi P; Pruisscher, Peter; Bensch, Staffan; Hansson, Bengt

    2015-05-01

    Isolated islands and their often unique biota continue to play key roles for understanding the importance of drift, genetic variation and adaptation in the process of population differentiation and speciation. One island system that has inspired and intrigued evolutionary biologists is the blue tit complex (Cyanistes spp.) in Europe and Africa, in particular the complex evolutionary history of the multiple genetically distinct taxa of the Canary Islands. Understanding Afrocanarian colonization events is of particular importance because of recent unconventional suggestions that these island populations acted as source of the widespread population in mainland Africa. We investigated the relationship between mainland and island blue tits using a combination of Sanger sequencing at a population level (20 loci; 12 500 nucleotides) and next-generation sequencing of single population representatives (>3 200 000 nucleotides), analysed in coalescence and phylogenetic frameworks. We found (i) that Afrocanarian blue tits are monophyletic and represent four major clades, (ii) that the blue tit complex has a continental origin and that the Canary Islands were colonized three times, (iii) that all island populations have low genetic variation, indicating low long-term effective population sizes and (iv) that populations on La Palma and in Libya represent relicts of an ancestral North African population. Further, demographic reconstructions revealed (v) that the Canary Islands, conforming to traditional views, hold sink populations, which have not served as source for back colonization of the African mainland. Our study demonstrates the importance of complete taxon sampling and an extensive multimarker study design to obtain robust phylogeographical inferences. PMID:25753616

  4. Variability of the infrared complex refractive index of African mineral dust: experimental estimation and implications for radiative transfer and satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Di Biagio, C.; Boucher, H.; Caquineau, S.; Chevaillier, S.; Cuesta, J.; Formenti, P.

    2014-04-01

    Experimental estimations of the infrared refractive index of African mineral dust have been retrieved from laboratory measurements of particle transmission spectra in the wavelength range 2.5-25 μm. Five dust samples collected at Banizoumbou (Niger) and Tamanrasset (Algeria) during dust events originated from different Western Saharan and Sahelian areas have been investigated. The obtained real (n) and imaginary (k) parts of the refractive index for the different dust cases vary in the range 1.1-2.7 and 0.05-1.0, respectively, and appear to be strongly sensitive to the mineralogical composition of the particles, especially in the 8-12 μm and 17-25 μm spectral intervals. Dust absorption is controlled mainly by clays, and, in minor fraction, by quartz and Ca-rich minerals. Size distribution, and the coarse fraction in particular, plays also a role in determining the refractive index. Significant differences are obtained when comparing our results with existing experimental estimations available in the literature, and with the values of the OPAC (Optical Properties of Aerosols and Clouds) database. The different datasets appear comparable in magnitude, with our values of n and k falling in the range of variability of past studies. However, literature data fail in accurately reproducing the spectral signatures of main minerals, in particular clays, and they significantly overestimate the contribution of quartz. We also found that the real and the imaginary parts of the refractive index from part of literature studies do not verify Kramers-Kronig relations, thus resulting theoretically incorrect. The comparison between our results, from Western Africa, and literature data, from different locations in Europe, Africa, and the Caribbean, nonetheless, confirms the expected large variability of the infrared refractive index of dust, thus highlighting the necessity for an extended systematic investigation. Aerosol intensive optical properties relevant to radiative transfer

  5. Variability of the infrared complex refractive index of African mineral dust: experimental estimation and implications for radiative transfer and satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Di Biagio, C.; Boucher, H.; Caquineau, S.; Chevaillier, S.; Cuesta, J.; Formenti, P.

    2014-10-01

    radiative transfer (mass extinction efficiency, kext, single scattering albedo, ω, and asymmetry factor, g) have been calculated, by using the Mie theory, based on the estimated refractive index and measured particle size distribution. The optical properties show a large sample-to-sample variability, with kext, ω, and g varying in the range 0.05-0.35, 0.25-1.0, and 0.05-0.75. This variability is expected to significantly impact satellite retrievals of atmospheric and surface parameters (e.g. from the Infrared Atmospheric Sounding Interferometer, IASI) and estimates of the dust radiative forcing.

  6. Pelvic radiation - discharge

    MedlinePlus

    Radiation of the pelvis - discharge; Cancer treatment - pelvic radiation; Prostate cancer - pelvic radiation; Ovarian cancer - pelvic radiation; Cervical cancer - pelvic radiation; Uterine cancer - pelvic radiation; Rectal cancer - ...

  7. Syntactic Complexity as an Aspect of Text Complexity

    ERIC Educational Resources Information Center

    Frantz, Roger S.; Starr, Laura E.; Bailey, Alison L.

    2015-01-01

    Students' ability to read complex texts is emphasized in the Common Core State Standards (CCSS) for English Language Arts and Literacy. The standards propose a three-part model for measuring text complexity. Although the model presents a robust means for determining text complexity based on a variety of features inherent to a text as well as…

  8. [The method based on generalized dosimetric function for estimation of cosmonauts' radiation hazard during long-term space missions].

    PubMed

    Shafirkin, A V; Grigor'ev, Iu G

    2002-01-01

    This paper presents a method of assessment of radiation hazard for cosmonauts. The method is based on a new dosimetric function, which enables a complicated nature of space radiation exposure to be reduced to the condition of a standard irradiation on Earth. It can be obtained on the basis of mean-tissue absorbed dose values calculated for each space radiation source, and transmission coefficients. The transmission coefficients define relative biological effectiveness of radiation and assess the influence on the radiobiological effects of the complex spatial and temporal distribution of the absorbed dose in the cosmonaut's body. The combination of cosmic ionizing radiation with other non-radiation nature factors in flight can be accounted. PMID:12449821

  9. Estimation of a cosmonaut's radiation hazard during long-term space missions on the basis of a generalized dosimetric function.

    PubMed

    Shafirkin, A V; Petrov, V M

    2002-01-01

    This paper presents a new concept of radiation hazard assessment for spacecraft crew members during long term space missions on the basis of a generalized dosimetric function. This new dosimetric function enables a complicated nature of space radiation exposure to be reduced to the conditions of a standard irradiation. It can be obtained on the basis of mean-tissue equivalent dose values calculated for each space radiation source and transmission coefficients describing the influence of the complex spatial and temporal distribution of the absorbed dose in the cosmonaut's body on the radiobiological effects. The combination of cosmic ionizing radiation with other non-radiation nature factors in flight can also be accounted for. In terms of the generalized dose, it is possible to assess the nature and extent of lowering a crew working capacity, as well as radiation risk, both during a flight and post flight period. PMID:12539776

  10. Setting Environmental Standards

    ERIC Educational Resources Information Center

    Fishbein, Gershon

    1975-01-01

    Recent court decisions have pointed out the complexities involved in setting environmental standards. Environmental health is composed of multiple causative agents, most of which work over long periods of time. This makes the cause-and-effect relationship between health statistics and environmental contaminant exposures difficult to prove in…

  11. Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose

    PubMed Central

    Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

    2015-01-01

    Objectives To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. Methods 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Results Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Conclusion Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels. PMID:26288186

  12. Space Radiation Risk Assessment

    NASA Astrophysics Data System (ADS)

    Blakely, E.

    Evaluation of potential health effects from radiation exposure during and after deep space travel is important for the future of manned missions To date manned missions have been limited to near-Earth orbits with the moon our farthest distance from earth Historical space radiation career exposures for astronauts from all NASA Missions show that early missions involved total exposures of less than about 20 mSv With the advent of Skylab and Mir total career exposure levels increased to a maximum of nearly 200 mSv Missions in deep space with the requisite longer duration of the missions planned may pose greater risks due to the increased potential for exposure to complex radiation fields comprised of a broad range of radiation types and energies from cosmic and unpredictable solar sources The first steps in the evaluation of risks are underway with bio- and physical-dosimetric measurements on both commercial flight personnel and international space crews who have experience on near-earth orbits and the necessary theoretical modeling of particle-track traversal per cell including the contributing effects of delta-rays in particle exposures An assumption for biologic effects due to exposure of radiation in deep space is that they differ quantitatively and qualitatively from that on earth The dose deposition and density pattern of heavy charged particles are very different from those of sparsely ionizing radiation The potential risks resulting from exposure to radiation in deep space are cancer non-cancer and genetic effects Radiation from

  13. Evaluation of conductive, radiative, chemical, and convective heat transfer in complex systems using a fast-running, implicit, lumped-capacitance formulation

    SciTech Connect

    Benjamin, A.S.; Beraun, R.; Brown, N.N.; Sherman, M.P.

    1995-05-01

    Accurate finite-element simulation of 3-D nonlinear heat transfer in complex systems may require meshes composed of tens of thousands of finite elements and hours of CPU time on today`s fastest computers. To treat applications in which thousands of calculations may be necessary such as for risk assessment or design of high-temperature manufacturing processes, methods are needed which can solve these problems far more efficiently and maintain an acceptably high degree of accuracy. For this purpose, we developed the Thermal Evaluation and Matching Program for Risk Applications (TEMPRA). The primary differentiator between TEMPRA and comparable codes is its numerical formulation, which is designed to be unconditionally stable even with very large time steps, to afford good accuracy even with relatively coarse meshing, and to facilitate benchmarking/calibration through the use of adjustable parameters. Analysis for a sample problem shows that TEMPRA can obtain temperature response solutions with errors of less than 10% using approximately 1/1000 of the computer time required by a typical finite element code.

  14. ARM Standards Policy Committee Report

    SciTech Connect

    Cialella, A; Jensen, M; Koontz, A; McFarlane, S; McCoy, R; Monroe, J; Palanisamy, G; Perez, R; Sivaraman, C

    2012-09-19

    Data and metadata standards promote the consistent recording of information and are necessary to ensure the stability and high quality of Atmospheric Radiation Measurement (ARM) Climate Research Facility data products for scientific users. Standards also enable automated routines to be developed to examine data, which leads to more efficient operations and assessment of data quality. Although ARM Infrastructure agrees on the utility of data and metadata standards, there is significant confusion over the existing standards and the process for allowing the release of new data products with exceptions to the standards. The ARM Standards Policy Committee was initiated in March 2012 to develop a set of policies and best practices for ARM data and metadata standards.

  15. American College of Radiology (ACR) and American Society for Radiation Oncology (ASTRO) Practice Guideline for Intensity-modulated Radiation Therapy (IMRT).

    PubMed

    Hartford, Alan C; Galvin, James M; Beyer, David C; Eichler, Thomas J; Ibbott, Geoffrey S; Kavanagh, Brian; Schultz, Christopher J; Rosenthal, Seth A

    2012-12-01

    Intensity-modulated radiation therapy (IMRT) is a complex technique for the delivery of radiation therapy preferentially to target structures while minimizing doses to adjacent normal critical structures. It is widely utilized in the treatment of a variety of clinical indications in radiation oncology, including tumors of the central nervous system, head and neck, breast, prostate, gastrointestinal tract, and gynecologic organs, as well as in situations where previous radiation therapy has been delivered, and has allowed for significant therapeutic advances in many clinical areas. IMRT treatment planning and delivery is a complex process. Safe and reliable delivery of IMRT requires appropriate process design and adherence to quality assurance (QA) standards. A collaborative effort of the American College of Radiology and American Society for Therapeutic Radiation Oncology has produced a practice guideline for IMRT. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist, dosimetrist, and radiation therapist. Factors with respect to the QA of the treatment planning system, treatment-planning process, and treatment-delivery process are discussed, as are issues related to the utilization of volumetric modulated arc therapy. Patient-specific QA procedures are presented. Successful IMRT programs involve integration of many processes: patient selection, patient positioning/immobilization, target definition, treatment plan development, and accurate treatment delivery. Appropriate QA procedures, including patient-specific QA procedures, are essential to ensure quality in an IMRT program and to assure patient safety.

  16. American College of Radiology (ACR) and American Society for Radiation Oncology (ASTRO) Practice Guideline for Intensity-modulated Radiation Therapy (IMRT).

    PubMed

    Hartford, Alan C; Galvin, James M; Beyer, David C; Eichler, Thomas J; Ibbott, Geoffrey S; Kavanagh, Brian; Schultz, Christopher J; Rosenthal, Seth A

    2012-12-01

    Intensity-modulated radiation therapy (IMRT) is a complex technique for the delivery of radiation therapy preferentially to target structures while minimizing doses to adjacent normal critical structures. It is widely utilized in the treatment of a variety of clinical indications in radiation oncology, including tumors of the central nervous system, head and neck, breast, prostate, gastrointestinal tract, and gynecologic organs, as well as in situations where previous radiation therapy has been delivered, and has allowed for significant therapeutic advances in many clinical areas. IMRT treatment planning and delivery is a complex process. Safe and reliable delivery of IMRT requires appropriate process design and adherence to quality assurance (QA) standards. A collaborative effort of the American College of Radiology and American Society for Therapeutic Radiation Oncology has produced a practice guideline for IMRT. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist, dosimetrist, and radiation therapist. Factors with respect to the QA of the treatment planning system, treatment-planning process, and treatment-delivery process are discussed, as are issues related to the utilization of volumetric modulated arc therapy. Patient-specific QA procedures are presented. Successful IMRT programs involve integration of many processes: patient selection, patient positioning/immobilization, target definition, treatment plan development, and accurate treatment delivery. Appropriate QA procedures, including patient-specific QA procedures, are essential to ensure quality in an IMRT program and to assure patient safety. PMID:23165357

  17. The program RADLST (Radiation Listing)

    SciTech Connect

    Burrows, T.W.

    1988-02-29

    The program RADLST (Radiation Listing) is designed to calculate the nuclear and atomic radiations associated with the radioactive decay of nuclei. It uses as its primary input nuclear decay data in the Evaluated Nuclear Structure Data File (ENSDF) format. The code is written in FORTRAN 77 and, with a few exceptions, is consistent with the ANSI standard. 65 refs.

  18. Space Radiation

    NASA Technical Reports Server (NTRS)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  19. The standard model

    SciTech Connect

    Marciano, W.J.

    1994-03-01

    In these lectures, my aim is to provide a survey of the standard model with emphasis on its renormalizability and electroweak radiative corrections. Since this is a school, I will try to be somewhat pedagogical by providing examples of loop calculations. In that way, I hope to illustrate some of the commonly employed tools of particle physics. With those goals in mind, I have organized my presentations as follows: In Section 2, renormalization is discussed from an applied perspective. The technique of dimensional regularization is described and used to define running couplings and masses. The utility of the renormalization group for computing leading logs is illustrated for the muon anomalous magnetic moment. In Section 3 electroweak radiative corrections are discussed. Standard model predictions are surveyed and used to constrain the top quark mass. The S, T, and U parameters are introduced and employed to probe for ``new physics``. The effect of Z{prime} bosons on low energy phenomenology is described. In Section 4, a detailed illustration of electroweak radiative corrections is given for atomic parity violation. Finally, in Section 5, I conclude with an outlook for the future.

  20. 24 CFR 51.203 - Safety standards.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ENVIRONMENTAL CRITERIA AND STANDARDS Siting of HUD-Assisted Projects Near Hazardous Operations Handling... standards shall be used in determining the acceptable separation distance of a proposed HUD-assisted project from a hazard: (a) Thermal Radiation Safety Standard. Projects shall be located so that: (1)...

  1. 24 CFR 51.203 - Safety standards.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ENVIRONMENTAL CRITERIA AND STANDARDS Siting of HUD-Assisted Projects Near Hazardous Operations Handling... standards shall be used in determining the acceptable separation distance of a proposed HUD-assisted project from a hazard: (a) Thermal Radiation Safety Standard. Projects shall be located so that: (1)...

  2. EOS standards

    SciTech Connect

    Greeff, Carl W

    2011-01-12

    An approach to creating accurate EOS for pressure standards is described. Applications to Cu, Au, and Ta are shown. Extension of the method to high compressions using DFT is illustrated. Comparisons with modern functionals show promise.

  3. Radiation: Balancing the record

    SciTech Connect

    Mann, C.C.

    1994-01-28

    This article reviews the radioactivity experiments performed on humans during the cold war, and examines the ethics of the experiments. The radiation experiments can be broadly classified into three groups: researchers knowingly inflicted potential harm, using methods questionable even by the then-current standards; the investigations involved good work by any standards with appropriate safeguards taken; and a third group which falls between the other two, the experiments provided useful information but had ethical flaws. The article also examines the experiments in the light of changing knowledge and moral standards.

  4. (Terminology standardization)

    SciTech Connect

    Strehlow, R.A.

    1990-10-19

    Terminological requirements in information management was but one of the principal themes of the 2nd Congress on Terminology and Knowledge Engineering. The traveler represented the American Society for Testing and Materials' Committee on Terminology, of which he is the Chair. The traveler's invited workshop emphasized terminology standardization requirements in databases of material properties as well as practical terminology standardizing methods. The congress included six workshops in addition to approximately 82 lectures and papers from terminologists, artificial intelligence practitioners, and subject specialists from 18 countries. There were approximately 292 registrants from 33 countries who participated in the congress. The congress topics were broad. Examples were the increasing use of International Standards Organization (ISO) Standards in legislated systems such as the USSR Automated Data Bank of Standardized Terminology, the enhanced Physics Training Program based on terminology standardization in Physics in the Chinese province of Inner Mongolia, and the technical concept dictionary being developed at the Japan Electronic Dictionary Research Institute, which is considered to be the key to advanced artificial intelligence applications. The more usual roles of terminology work in the areas of machine translation. indexing protocols, knowledge theory, and data transfer in several subject specialties were also addressed, along with numerous special language terminology areas.

  5. Radiation dosimetry and biophysical models of space radiation effects

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wu, Honglu; Shavers, Mark R.; George, Kerry

    2003-01-01

    Estimating the biological risks from space radiation remains a difficult problem because of the many radiation types including protons, heavy ions, and secondary neutrons, and the absence of epidemiology data for these radiation types. Developing useful biophysical parameters or models that relate energy deposition by space particles to the probabilities of biological outcomes is a complex problem. Physical measurements of space radiation include the absorbed dose, dose equivalent, and linear energy transfer (LET) spectra. In contrast to conventional dosimetric methods, models of radiation track structure provide descriptions of energy deposition events in biomolecules, cells, or tissues, which can be used to develop biophysical models of radiation risks. In this paper, we address the biophysical description of heavy particle tracks in the context of the interpretation of both space radiation dosimetry and radiobiology data, which may provide insights into new approaches to these problems.

  6. Radiation dosimetry and biophysical models of space radiation effects.

    PubMed

    Cucinotta, Francis A; Wu, Honglu; Shavers, Mark R; George, Kerry

    2003-06-01

    Estimating the biological risks from space radiation remains a difficult problem because of the many radiation types including protons, heavy ions, and secondary neutrons, and the absence of epidemiology data for these radiation types. Developing useful biophysical parameters or models that relate energy deposition by space particles to the probabilities of biological outcomes is a complex problem. Physical measurements of space radiation include the absorbed dose, dose equivalent, and linear energy transfer (LET) spectra. In contrast to conventional dosimetric methods, models of radiation track structure provide descriptions of energy deposition events in biomolecules, cells, or tissues, which can be used to develop biophysical models of radiation risks. In this paper, we address the biophysical description of heavy particle tracks in the context of the interpretation of both space radiation dosimetry and radiobiology data, which may provide insights into new approaches to these problems. PMID:12959127

  7. Head Resistance Due to Radiators

    NASA Technical Reports Server (NTRS)

    Kleinschmidt, R V; Parsons, S R

    1920-01-01

    Part 1 deals with the head resistance of a number of common types of radiator cores at different speeds in free air, as measured in the wind tunnel at the bureau of standards. This work was undertaken to determine the characteristics of various types of radiator cores, and in particular to develop the best type of radiator for airplanes. Some 25 specimens of core were tested, including practically all the general types now in use, except the flat plate type. Part 2 gives the results of wind tunnel tests of resistance on a model fuselage with a nose radiator. Part 3 presents the results of preliminary tests of head resistance of a radiator enclosed in a streamlined casing. Special attention is given to the value of wing radiator and of the radiator located in the open, especially when it is provided with a properly designed streamlined casing.

  8. DOE standard: Radiological control

    SciTech Connect

    Not Available

    1999-07-01

    The Department of Energy (DOE) has developed this Standard to assist line managers in meeting their responsibilities for implementing occupational radiological control programs. DOE has established regulatory requirements for occupational radiation protection in Title 10 of the Code of Federal Regulations, Part 835 (10 CFR 835), ``Occupational Radiation Protection``. Failure to comply with these requirements may lead to appropriate enforcement actions as authorized under the Price Anderson Act Amendments (PAAA). While this Standard does not establish requirements, it does restate, paraphrase, or cite many (but not all) of the requirements of 10 CFR 835 and related documents (e.g., occupational safety and health, hazardous materials transportation, and environmental protection standards). Because of the wide range of activities undertaken by DOE and the varying requirements affecting these activities, DOE does not believe that it would be practical or useful to identify and reproduce the entire range of health and safety requirements in this Standard and therefore has not done so. In all cases, DOE cautions the user to review any underlying regulatory and contractual requirements and the primary guidance documents in their original context to ensure that the site program is adequate to ensure continuing compliance with the applicable requirements. To assist its operating entities in achieving and maintaining compliance with the requirements of 10 CFR 835, DOE has established its primary regulatory guidance in the DOE G 441.1 series of Guides. This Standard supplements the DOE G 441.1 series of Guides and serves as a secondary source of guidance for achieving compliance with 10 CFR 835.

  9. Survivors and scientists: Hiroshima, Fukushima, and the Radiation Effects Research Foundation, 1975-2014.

    PubMed

    Lindee, Susan

    2016-04-01

    In this article, I reflect on the Radiation Effects Research Foundation and its ongoing studies of long-term radiation risk. Originally called the Atomic Bomb Casualty Commission (1947-1975), the Radiation Effects Research Foundation has carried out epidemiological research tracking the biomedical effects of radiation at Hiroshima and Nagasaki for almost 70 years. Radiation Effects Research Foundation scientists also played a key role in the assessment of populations exposed at Chernobyl and are now embarking on studies of workers at the Fukushima Daiichi Nuclear Power Plant. I examine the role of estimating dosimetry in post-disaster epidemiology, highlight how national identity and citizenship have mattered in radiation risk networks, and track how participants interpreted the relationships between nuclear weapons and nuclear energy. Industrial interests in Japan and the United States sought to draw a sharp line between the risks of nuclear war and the risks of nuclear power, but the work of the Radiation Effects Research Foundation (which became the basis of worker protection standards for the industry) and the activism of atomic bomb survivors have drawn these two nuclear domains together. This is so particularly in the wake of the Fukushima disaster, Japan's 'third atomic bombing'. The Radiation Effects Research Foundation is therefore a critical node in a complex global network of scientific institutions that adjudicate radiation risk and proclaim when it is present and when absent. Its history, I suggest, can illuminate some properties of modern disasters and the many sciences that engage with them.

  10. Survivors and scientists: Hiroshima, Fukushima, and the Radiation Effects Research Foundation, 1975-2014.

    PubMed

    Lindee, Susan

    2016-04-01

    In this article, I reflect on the Radiation Effects Research Foundation and its ongoing studies of long-term radiation risk. Originally called the Atomic Bomb Casualty Commission (1947-1975), the Radiation Effects Research Foundation has carried out epidemiological research tracking the biomedical effects of radiation at Hiroshima and Nagasaki for almost 70 years. Radiation Effects Research Foundation scientists also played a key role in the assessment of populations exposed at Chernobyl and are now embarking on studies of workers at the Fukushima Daiichi Nuclear Power Plant. I examine the role of estimating dosimetry in post-disaster epidemiology, highlight how national identity and citizenship have mattered in radiation risk networks, and track how participants interpreted the relationships between nuclear weapons and nuclear energy. Industrial interests in Japan and the United States sought to draw a sharp line between the risks of nuclear war and the risks of nuclear power, but the work of the Radiation Effects Research Foundation (which became the basis of worker protection standards for the industry) and the activism of atomic bomb survivors have drawn these two nuclear domains together. This is so particularly in the wake of the Fukushima disaster, Japan's 'third atomic bombing'. The Radiation Effects Research Foundation is therefore a critical node in a complex global network of scientific institutions that adjudicate radiation risk and proclaim when it is present and when absent. Its history, I suggest, can illuminate some properties of modern disasters and the many sciences that engage with them. PMID:27263236

  11. Radiation Exposure

    MedlinePlus

    Radiation is energy that travels in the form of waves or high-speed particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a ...

  12. Paediatric radiation oncology in the care of childhood cancer: A position paper by the International Paediatric Radiation Oncology Society (PROS).

    PubMed

    Kortmann, Rolf-Dieter; Freeman, Carolyn; Marcus, Karen; Claude, Line; Dieckmann, Karin; Halperin, Edward; Esiashvili, Natia; Paulino, Arnold; Mahajan, Anita; Seiersen, Klaus; Ahern, Verity; Ricardi, Umberto; Carrie, Christian

    2016-05-01

    Paediatric malignancies are a challenge for the radiation oncologist due to their rarity, the great variety of histological types, and the complexity of treatment concepts that evolve over time. The Paediatric Radiation Oncology Society (PROS) is the only internationally operating society for paediatric radiation oncology. The objectives of PROS are to set a world-wide standard of excellence with respect to radiation oncology aspects in curing children and adolescents with cancer, to provide a forum for communication between radiation oncologists, and to exchange information with all professionals involved in the management of paediatric and adolescent cancer. Challenges include the need to promote education and support practice in low and middle income countries (LMIC) as well as the cost and availability of modern treatment technologies for all but most especially these countries. Collaborations with other societies that include for example the education programmes provided jointly with ESTRO, and the upgraded technical platform of the PROS web site offer new possibilities to enhance the efficacy of PROS in education and support of paediatric radiation oncology practice world-wide. PROS has made an important contribution to the management of childhood malignancies over the past decade and new and developing collaborations between PROS and other societies or organizations will ultimately lead to a reduction in world-wide health care inequalities. PMID:27106553

  13. Radiation physics, biophysics, and radiation biology

    SciTech Connect

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  14. Complexity in Picture Books

    ERIC Educational Resources Information Center

    Sierschynski, Jarek; Louie, Belinda; Pughe, Bronwyn

    2015-01-01

    One of the key requirements of Common Core State Standards (CCSS) in English Language Arts is that students are able to read and access complex texts across all grade levels. The CCSS authors emphasize both the limitations and lack of accuracy in the current CCSS model of text complexity, calling for the development of new frameworks. In response…

  15. Radiation Proctopathy

    PubMed Central

    Grodsky, Marc B.; Sidani, Shafik M.

    2015-01-01

    Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options. PMID:26034407

  16. Radiation proctopathy.

    PubMed

    Grodsky, Marc B; Sidani, Shafik M

    2015-06-01

    Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options. PMID:26034407

  17. 47 CFR 95.635 - Unwanted radiation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Unwanted radiation. 95.635 Section 95.635... SERVICES Technical Regulations Technical Standards § 95.635 Unwanted radiation. Link to an amendment... Unwanted radiation. (d) * * * (1) * * * (v) Are more than 2.5 MHz outside of the 2360-2400 MHz band...

  18. 14 CFR 29.1023 - Oil radiators.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil radiators. 29.1023 Section 29.1023... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1023 Oil radiators. (a) Each oil radiator must be able to withstand any vibration, inertia, and oil pressure loads to which it would...

  19. 14 CFR 29.1023 - Oil radiators.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Oil radiators. 29.1023 Section 29.1023... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1023 Oil radiators. (a) Each oil radiator must be able to withstand any vibration, inertia, and oil pressure loads to which it would...

  20. 14 CFR 29.1023 - Oil radiators.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil radiators. 29.1023 Section 29.1023... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1023 Oil radiators. (a) Each oil radiator must be able to withstand any vibration, inertia, and oil pressure loads to which it would...

  1. 14 CFR 29.1023 - Oil radiators.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil radiators. 29.1023 Section 29.1023... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1023 Oil radiators. (a) Each oil radiator must be able to withstand any vibration, inertia, and oil pressure loads to which it would...

  2. 14 CFR 25.1023 - Oil radiators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil radiators. 25.1023 Section 25.1023... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1023 Oil radiators. (a) Each oil radiator must be able to withstand, without failure, any vibration, inertia, and oil pressure load to which...

  3. 14 CFR 23.1023 - Oil radiators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil radiators. 23.1023 Section 23.1023... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1023 Oil radiators. Each oil radiator and its supporting structures must be able to withstand the vibration,...

  4. 14 CFR 29.1023 - Oil radiators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil radiators. 29.1023 Section 29.1023... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1023 Oil radiators. (a) Each oil radiator must be able to withstand any vibration, inertia, and oil pressure loads to which it would...

  5. ANS shielding standards for light-water reactors

    SciTech Connect

    Trubey, D.K.

    1982-01-01

    The purpose of the American Nuclear Society Standards Subcommittee, ANS-6, Radiation Protection and Shielding, is to develop standards for radiation protection and shield design, to provide shielding information to other standards-writing groups, and to develop standard reference shielding data and test problems. A total of seven published ANS-6 standards are now current. Additional projects of the subcommittee, now composed of nine working groups, include: standard reference data for multigroup cross sections, gamma-ray absorption coefficients and buildup factors, additional benchwork problems for shielding problems and energy spectrum unfolding, power plant zoning design for normal and accident conditions, process radiation monitors, and design for postaccident radiological conditions.

  6. [Radiation protection agents to provide the radiation safety of astronauts].

    PubMed

    2013-01-01

    Taking into consideration the complexity of radiation factors and stressogenic factors of non-radiation nature in cosmic flights and prognostic difficulties of radiation situation, the authors propose to distinguish several stages of pharmacological protection for cosmonauts. The preparatory stage is realized on the Earth. The next stage is monitoring and correction of radioresistance during a flight. A possible stage consists of treatment of the radiation damage using a traditional protocol. The permanent stage includes pharmacological prevention of the distant consequences of irradiation. PMID:25507772

  7. [Radiation protection agents to provide the radiation safety of astronauts].

    PubMed

    Ushakov, I B; Ivanov, A A

    2013-01-01

    Taking into consideration the complexity of radiation factors and stressogenic factors of non-radiation nature in cosmic flights and prognostic difficulties of radiation situation, the authors propose to distinguish several stages of pharmacological protection for cosmonauts. The preparatory stage is realized on the Earth. The next stage is monitoring and correction of radioresistance during a flight. A possible stage consists of treatment of the radiation damage using a traditional protocol. The permanent stage includes pharmacological prevention of the distant consequences of irradiation. PMID:25434174

  8. ISO WD 1856. Guideline for radiation exposure of nonmetallic materials. Present status

    NASA Astrophysics Data System (ADS)

    Briskman, B. A.

    In the framework of the International Organization for Standardization (ISO) activity we started development of international standard series for space environment simulation at on-ground tests of materials. The proposal was submitted to ISO Technical Committee 20 (Aircraft and Space Vehicles), Subcommittee 14 (Space Systems and Operations) and was approved as Working Draft 15856 at the Los-Angeles meeting (1997). A draft of the first international standard "Space Environment Simulation for Radiation Tests of Materials" (1st version) was presented at the 7th International Symposium on Materials in Space Environment (Briskman et al, 1997). The 2nd version of the standard was limited to nonmetallic materials and presented at the 20th Space Simulation Conference (Briskman and Borson, 1998). It covers the testing of nonmetallic materials embracing also polymer composite materials including metal components (metal matrix composites) to simulated space radiation. The standard does not cover semiconductor materials. The types of simulated radiation include charged particles (electrons and protons), solar ultraviolet radiation, and soft X-radiation of solar flares. Synergistic interactions of the radiation environment are covered only for these natural and some induced environmental effects. This standard outlines the recommended methodology and practices for the simulation of space radiation on materials. Simulation methods are used to reproduce the effects of the space radiation environment on materials that are located on surfaces of space vehicles and behind shielding. It was discovered that the problem of radiation environment simulation is very complex and the approaches of different specialists and countries to the problem are sometimes quite opposite. To the present moment we developed seven versions of the standard. The last version is a compromise between these approaches. It was approved at the last ISO TC20/SC14/WG4 meeting in Houston, October 2002. At a

  9. Radiation Chemistry

    NASA Astrophysics Data System (ADS)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  10. Radiation Safety System for Stanford Synchrotron Radiation Laboratory

    SciTech Connect

    Liu, J

    2004-03-12

    Radiation Safety System (RSS) at the Stanford Synchrotron Radiation Laboratory is summarized and reviewed. The RSS, which is designed to protect people from prompt radiation hazards from accelerator operation, consists of the Access Control System (ACS) and the Beam Containment System (BCS). The ACS prevents people from being exposed to the lethal radiation level inside the shielding housing (called a PPS area at SLAC). The ACS for a PPS area consists of the shielding housing, beam inhibiting devices, and a standard entry module at each entrance. The BCS protects people from the prompt radiation hazards outside a PPS area under both normal and abnormal beam loss situations. The BCS consists of the active power (current/energy) limiting devices, beam stoppers, shielding, and an active radiation monitor system. The policies and practices in setting up the RSS at SLAC are illustrated.

  11. 40 CFR 197.20 - What standard must DOE meet?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS PUBLIC HEALTH AND ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR YUCCA MOUNTAIN, NEVADA Public... committed effective dose equivalent from releases from the undisturbed Yucca Mountain disposal system:...

  12. 40 CFR 197.20 - What standard must DOE meet?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS PUBLIC HEALTH AND ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR YUCCA MOUNTAIN, NEVADA Public... assessment must include all potential pathways of radionuclide transport and exposure....

  13. Radiative equilibrium in Monte Carlo radiative transfer using frequency distribution adjustment

    NASA Astrophysics Data System (ADS)

    Baes, Maarten; Stamatellos, Dimitris; Davies, Jonathan I.; Whitworth, Anthony P.; Sabatini, Sabina; Roberts, Sarah; Linder, Suzanne M.; Evans, Rhodri

    2005-06-01

    The Monte Carlo method is a powerful tool for performing radiative equilibrium calculations, even in complex geometries. The main drawback of the standard Monte Carlo radiative equilibrium methods is that they require iteration, which makes them numerically very demanding. Bjorkman and Wood recently proposed a frequency distribution adjustment scheme, which allows radiative equilibrium Monte Carlo calculations to be performed without iteration, by choosing the frequency of each re-emitted photon such that it corrects for the incorrect spectrum of the previously re-emitted photons. Though, the method appears to yield correct results, we argue that its theoretical basis is not completely transparent, and that it is not completely clear whether this technique is an exact rigorous method, or whether it is just a good and convenient approximation. We critically study the general problem of how an already sampled distribution can be adjusted to a new distribution by adding data points sampled from an adjustment distribution. We show that this adjustment is not always possible, and that it depends on the shape of the original and desired distributions, as well as on the relative number of data points that can be added. Applying this theorem to radiative equilibrium Monte Carlo calculations, we provide a firm theoretical basis for the frequency distribution adjustment method of Bjorkman and Wood, and we demonstrate that this method provides the correct frequency distribution through the additional requirement of radiative equilibrium. We discuss the advantages and limitations of this approach, and show that it can easily be combined with the presence of additional heating sources and the concept of photon weighting. However, the method may fail if small dust grains are included, or if the absorption rate is estimated from the mean intensity of the radiation field.

  14. The Effects of Radiation on Imagery Sensors in Space

    NASA Technical Reports Server (NTRS)

    Mathis, Dylan

    2007-01-01

    Recent experience using high definition video on the International Space Station reveals camera pixel degradation due to particle radiation to be a much more significant problem with high definition cameras than with standard definition video. Although it may at first appear that increased pixel density on the imager is the logical explanation for this, the ISS implementations of high definition suggest a more complex causal and mediating factor mix. The degree of damage seems to vary from one type of camera to another, and this variation prompts a reconsideration of the possible factors in pixel loss, such as imager size, number of pixels, pixel aperture ratio, imager type (CCD or CMOS), method of error correction/concealment, and the method of compression used for recording or transmission. The problem of imager pixel loss due to particle radiation is not limited to out-of-atmosphere applications. Since particle radiation increases with altitude, it is not surprising to find anecdotal evidence that video cameras subject to many hours of airline travel show an increased incidence of pixel loss. This is even evident in some standard definition video applications, and pixel loss due to particle radiation only stands to become a more salient issue considering the continued diffusion of high definition video cameras in the marketplace.

  15. Radiator technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1993-01-01

    Radiator technology is discussed in the context of the Civilian Space Technology Initiative's (CSTI's) high capacity power-thermal management project. The CSTI project is a subset of a project to develop a piloted Mars nuclear electric propulsion (NEP) vehicle. The following topics are presented in vugraph form: advanced radiator concepts; heat pipe codes and testing; composite materials; radiator design and integration; and surface morphology.

  16. Hawking radiation

    NASA Astrophysics Data System (ADS)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  17. Fabric space radiators

    SciTech Connect

    Antoniak, Z.I.; Krotiuk, W.J.; Webb, B.J.; Prater, J.T.; Bates, J.M.

    1988-01-01

    Future Air Force space missions will require thermal radiators that both survive in the hostile space environment and stow away for minimal bulk during launch. Advances in all aspects of radiator design, construction, and analysis will be necessary to enable such future missions. Currently, the best means for obtaining high strength along with flexibility is through structures known as fabrics. The development of new materials and bonding techniques has extended the application range of fabrics into areas traditionally dominated by monolithic and/or metallic structures. Given that even current spacecraft heat rejection considerations tend to dominate spacecraft design and mass, the larger and more complex designs of the future face daunting challenges in thermal control. Ceramic fabrics bonded to ultra-thin metal liners (foils) have the potential of achieving radiator performance levels heretofore unattainable, and of readily matching the advances made in other branches of spacecraft design. The research effort documented here indicates that both pumped loops and heat pipes constructed in ceramic fabrics stand to benefit in multiple ways. Flexibility and low mass are the main advantages exhibited by fabric radiators over conventional metal ones. We feel that fabric radiators have intrinsic merits not possessed by any other radiator design and need to be researched further. 26 refs., 16 figs., 17 tabs.

  18. Radiation protection of the public: Past, present, and future

    SciTech Connect

    Kocher, D.C.

    1990-01-01

    This paper discusses the historical development of radiation protection standards for the public, the present system in the United States for limiting radiation exposures of the public primarily by means of environmental radiation standards for specific practices or sources, and recent developments that may affect future standards and policies for radiation protection of the public. The radiobiological and epidemiological basis for radiation protection standards and policies is emphasized. Difficulties associated with the current regulatory framework are discussed, and proposal for addressing these difficulties are presented. 16 refs., 1 tab.

  19. REDUCTION OF ECHO DECORRELATION VIA COMPLEX PRINCIPAL COMPONENT FILTERING

    PubMed Central

    Mauldin, F. William; Viola, Francesco; Walker, William F.

    2009-01-01

    Ultrasound motion estimation is a fundamental component of clinical and research techniques that include color flow Doppler, spectral Doppler, radiation force imaging and ultrasound-based elasticity estimation. In each of these applications, motion estimates are corrupted by signal decorrelation that originates from nonuniform target motion across the acoustic beam. In this article, complex principal component filtering (PCF) is demonstrated as a filtering technique for dramatically reducing echo decorrelation in blood flow estimation and radiation force imaging. We present simulation results from a wide range of imaging conditions that illustrate a dramatic improvement over simple bandpass filtering in terms of overall echo decorrelation (≤99.9% reduction), root mean square error (≤97.3% reduction) and the standard deviation of displacement estimates (≤97.4% reduction). A radiation force imaging technique, termed sonorheometry, was applied to fresh whole blood during coagulation, and complex PCF operated on the returning echoes. Sonorheometry was specifically chosen as an example radiation force imaging technique in which echo decorrelation corrupts motion estimation. At 2 min after initiation of blood coagulation, the average echo correlation for sonorheometry improved from 0.996 to 0.9999, which corresponded to a 41.0% reduction in motion estimation variance as predicted by the Cramer-Rao lower bound under reasonable imaging conditions. We also applied complex PCF to improve blood velocity estimates from the left carotid artery of a healthy 23-year-old male. At the location of peak blood velocity, complex PCF improved the correlation of consecutive echo signals from an average correlation of 0.94 to 0.998. The improved echo correlation for both sonorheometry and blood flow estimation yielded motion estimates that exhibited more consistent responses with less noise. Complex PCF reduces speckle decorrelation and improves the performance of ultrasonic motion

  20. 2015 Space Radiation Standing Review Panel

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan

    2015-01-01

    The 2015 Space Radiation Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 8 - 9, 2015. The SRP met with representatives from the Space Radiation Element and members of the Human Research Program (HRP) to review the updated research plan for the Risk of Radiation Carcinogenesis Cancer Risk. The SRP also reviewed the newly revised Evidence Reports for the Risk of Acute Radiation Syndromes Due to Solar Particle Events (SPEs) (Acute Risk), the Risk of Acute (In-flight) and Late Central Nervous System Effects from Radiation Exposure (CNS Risk), and the Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation (Degen Risk), as well as a status update on these Risks. The SRP would like to commend Dr. Simonsen, Dr. Huff, Dr. Nelson, and Dr. Patel for their detailed presentations. The Space Radiation Element did a great job presenting a very large volume of material. The SRP considers it to be a strong program that is well-organized, well-coordinated and generates valuable data. The SRP commended the tissue sharing protocols, working groups, systems biology analysis, and standardization of models. In several of the discussed areas the SRP suggested improvements of the research plans in the future. These include the following: It is important that the team has expanded efforts examining immunology and inflammation as important components of the space radiation biological response. This is an overarching and important focus that is likely to apply to all aspects of the program including acute, CVD, CNS, cancer and others. Given that the area of immunology/inflammation is highly complex (and especially so as it relates to radiation), it warrants the expansion of investigators expertise in immunology and inflammation to work with the individual research projects and also the NASA Specialized Center of Research (NSCORs). Historical data on radiation injury to be entered into the Watson

  1. Stochastic Radiative transfer and real cloudiness

    SciTech Connect

    Evans, F.

    1995-09-01

    Plane-parallel radiative transfer modeling of clouds in GCMs is thought to be an inadequate representation of the effects of real cloudiness. A promising new approach for studying the effects of cloud horizontal inhomogeneity is stochastic radiative transfer, which computes the radiative effects of ensembles of cloud structures described by probability distributions. This approach is appropriate because cloud information is inherently statistical, and it is the mean radiative effect of complex 3D cloud structure that is desired. 2 refs., 1 fig.

  2. Standards Laboratory environments

    SciTech Connect

    Braudaway, D.W.

    1990-09-01

    Standards Laboratory environments need to be carefully selected to meet the specific mission of each laboratory. The mission of the laboratory depends on the specific work supported, the measurement disciplines required and the level of uncertainty required in the measurements. This document reproduces the contents of the Sandia National Laboratories Primary Standards Laboratory Memorandum Number 3B (PSLM-3B) which was issued on May 16, 1988, under the auspices of the Department of Energy, Albuquerque Operations Office, to guide the laboratories of the Nuclear Weapons Complex in selecting suitable environments. Because of both general interest and specific interest in Standards Laboratory environments this document is being issued in a more available form. The purpose of this document is to provide guidance in selection of laboratory environments suitable for standards maintenance and calibration operations. It is not intended to mandate a specific environment for a specific calibration but to direct selection of the environment and to offer suggestions on how to extend precision in an existing and/or achievable (practical) environment. Although this documents pertains specifically to standards laboratories, it can be applied to any laboratory requiring environmental control.

  3. Understanding Radiation.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    Radiation is a natural energy force that has been a part of the environment since the Earth was formed. It takes various forms, none of which can be smelled, tasted, seen, heard, or felt. Nevertheless, scientists know what it is, where it comes from, how to measure and detect it, and how it affects people. Cosmic radiation from outer space and…

  4. Formation of complex organic molecules in methanol and methanol-carbon monoxide ices exposed to ionizing radiation--a combined FTIR and reflectron time-of-flight mass spectrometry study.

    PubMed

    Maity, Surajit; Kaiser, Ralf I; Jones, Brant M

    2015-02-01

    The radiation induced chemical processing of methanol and methanol-carbon monoxide ices at 5.5 K exposed to ionizing radiation in the form of energetic electrons and subsequent temperature programmed desorption is reported in this study. The endogenous formation of complex organic molecules was monitored online and in situ via infrared spectroscopy in the solid state and post irradiation with temperature programmed desorption (TPD) using highly sensitive reflectron time-of-flight (ReTOF) mass spectrometry coupled with single photoionization at 10.49 eV. Infrared spectroscopic analysis of the processed ice systems resulted in the identification of simple molecules including the hydroxymethyl radical (CH2OH), formyl radical (HCO), methane (CH4), formaldehyde (H2CO), carbon dioxide (CO2), ethylene glycol (HOCH2CH2OH), glycolaldehyde (HOCH2CHO), methyl formate (HCOOCH3), and ketene (H2CCO). In addition, ReTOF mass spectrometry of subliming molecules following temperature programmed desorption definitely identified several closed shell C/H/O bearing organics including ketene (H2CCO), acetaldehyde (CH3COH), ethanol (C2H5OH), dimethyl ether (CH3OCH3), glyoxal (HCOCOH), glycolaldehyde (HOCH2CHO), ethene-1,2-diol (HOCHCHOH), ethylene glycol (HOCH2CH2OH), methoxy methanol (CH3OCH2OH) and glycerol (CH2OHCHOHCH2OH) in the processed ice systems. Additionally, an abundant amount of molecules yet to be specifically identified were observed sublimating from the irradiated ices including isomers with the formula C3H(x=4,6,8)O, C4H(x=8,10)O, C3H(x=4,6,8)O2, C4H(x=6,8)O2, C3H(x=4,6)O3, C4H8O3, C4H(x=4,6,8)O4, C5H(x=6,8)O4 and C5H(x=6,8)O5. The last group of molecules containing four to five oxygen atoms observed sublimating from the processed ice samples include an astrobiologically important class of sugars relevant to RNA, phospholipids and energy storage. Experiments are currently being designed to elucidate their chemical structure. In addition, several reaction pathways were

  5. Interaction of CO 2 laser radiation with glasses

    NASA Astrophysics Data System (ADS)

    Kozhukharov, V.; Dimitrov, D.; Tonchev, D.

    1989-05-01

    An illustration of an interaction of pulsed multimode TEA CO 2 laser radiation, through or without a mask, as well as of a laser scanning process of a frequency Q-modulated cw CO 2 laser beam on glass surfaces has been shown. As an object of investigation glass articles with composition as a standard industrial potassium-boron silicate glass, we have used. A complex of investigations shows that the laser treatment leads to qualitative constant changes (well defined peeling structure) depending on the time surface treatment, defocusing and the pulse length of the laser output.

  6. Radiative accidental matter

    NASA Astrophysics Data System (ADS)

    Sierra, D. Aristizabal; Simoes, C.; Wegman, D.

    2016-07-01

    Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that μ → eγ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below 5×105 GeV, a value (naturally) assured by the radiative suppression mechanism. Sizeable τ → μγ branching fractions within SuperKEKB sensitivity are possible for lower lepton-number breaking scales. We thus point out that these scenarios can be tested not only in direct searches but also in lepton flavor-violating experiments.

  7. Radiation effects in materials

    NASA Astrophysics Data System (ADS)

    Dauphin, J.

    1994-01-01

    In contrast to electronic components, materials are, in general, quite resistant to the conditions encountered in space from the point of view of radiation effects. There exist however some groups of materials which can cause concern, particularly when they are used on the outside of spacecraft. These include fluorinated polymers, oxide glasses and paints. Normally only very sensitive properties like the thermo-optical ones may be significantly degraded in near earth space. The extremely used geostationary orbit is the most dangerous in this respect. Another characteristic of materials is that degration is a complex phenomenon, of which particulate radiation is not the only cause. Synergistic effects are the rule and the influence of the complete space environment including temperature, UV radiation, particles, contamination, etc. must be assessed. This strongly complicates the ground simulation experiments.

  8. Space radiation protection issues.

    PubMed

    Kronenberg, Amy; Cucinotta, Francis A

    2012-11-01

    The complex charged particle environments in space pose considerable challenges with regard to potential health consequences that can impact mission design and crew selection. The lack of knowledge of the biological effects of different ions in isolation and in combination is a particular concern because the risk uncertainties are very high for both cancer and non-cancer late effects. Reducing the uncertainties is of high priority. Two principal components of space radiation each raise different concerns. Solar particle events (SPE) occur sporadically and are comprised primarily of low- to moderate-energy protons. Galactic cosmic radiation (GCR) is isotropic and relatively invariant in dose rate. GCR is also dominated by protons, but the energy range is wider than in SPE. In addition, the contribution of other light and heavy ions to the health risks from GCR must be addressed. This paper will introduce the principal issues under consideration for space radiation protection. PMID:23032885

  9. Radiation detector

    DOEpatents

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  10. Radiation detector

    DOEpatents

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  11. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  12. Standardizing Immunohistochemistry

    PubMed Central

    Sompuram, Seshi R.; Vani, Kodela; Tracey, Brian; Kamstock, Debra A.

    2015-01-01

    A new standardized immunohistochemistry (IHC) control for breast cancer testing comprises formalin-fixed human epidermal growth factor receptor 2, estrogen receptor, or progesterone receptor peptide antigens covalently attached to 8-µm glass beads. The antigen-coated beads are suspended in a liquid matrix that hardens upon pipetting onto a glass microscope slide. The antigen-coated beads remain in place through deparaffinization, antigen retrieval, and immunostaining. The intensity of the beads’ stain provides feedback regarding the efficacy of both antigen retrieval and immunostaining. As a first report, we tested the sensitivity and specificity of the new IHC controls (“IHControls”). To evaluate sensitivity, various staining problems were simulated. IHControls detected primary and secondary reagent degradation similarly to tissue controls. This first group of IHControls behaved similarly to tissue controls expressing high concentrations of the antigen. The IHControls were also able to detect aberrations in antigen retrieval, as simulated by sub-optimal times or temperatures. Specificity testing revealed that each antigen-coated bead was specific for its cognate IHC test antibody. The data support the conclusion that, like tissue controls, IHControls are capable of verifying the analytic components of an immunohistochemical stain. Unlike tissue controls, IHControls are prepared in large bulk lots, fostering day-to-day reproducibility that can be standardized across laboratories. PMID:25940339

  13. Engineered and Administrative Safety Systems for the Control of Prompt Radiation Hazards at Accelerator Facilities

    SciTech Connect

    Liu, James C.; Vylet, Vashek; Walker, Lawrence S.; /SLAC

    2007-12-17

    The ANSI N43.1 Standard, currently in revision (ANSI 2007), sets forth the requirements for accelerator facilities to provide adequate protection for the workers, the public and the environment from the hazards of ionizing radiation produced during and from accelerator operations. The Standard also recommends good practices that, when followed, provide a level of radiation protection consistent with those established for the accelerator communities. The N43.1 Standard is suitable for all accelerator facilities (using electron, positron, proton, or ion particle beams) capable of producing radiation, subject to federal or state regulations. The requirements (see word 'shall') and recommended practices (see word 'should') are prescribed in a graded approach that are commensurate with the complexity and hazard levels of the accelerator facility. Chapters 4, 5 and 6 of the N43.1 Standard address specially the Radiation Safety System (RSS), both engineered and administrative systems, to mitigate and control the prompt radiation hazards from accelerator operations. The RSS includes the Access Control System (ACS) and Radiation Control System (RCS). The main requirements and recommendations of the N43.1 Standard regarding the management, technical and operational aspects of the RSS are described and condensed in this report. Clearly some aspects of the RSS policies and practices at different facilities may differ in order to meet the practical needs for field implementation. A previous report (Liu et al. 2001a), which reviews and summarizes the RSS at five North American high-energy accelerator facilities, as well as the RSS references for the 5 labs (Drozdoff 2001; Gallegos 1996; Ipe and Liu 1992; Liu 1999; Liu 2001b; Rokni 1996; TJNAF 1994; Yotam et al. 1991), can be consulted for the actual RSS implementation at various laboratories. A comprehensive report describing the RSS at the Stanford Linear Accelerator Center (SLAC 2006) can also serve as a reference.

  14. DNA Damage by Ionizing Radiation: Tandem Double Lesions by Charged Particles

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Chaban, Galina M.; Wang, Dunyou; Dateo, Christopher E.

    2005-01-01

    Oxidative damages by ionizing radiation are the source of radiation-induced carcinogenesis, damage to the central nervous system, lowering of the immune response, as well as other radiation-induced damages to human health. Monte Carlo track simulations and kinetic modeling of radiation damages to the DNA employ available molecular and cellular data to simulate the biological effect of high and low LET radiation io the DNA. While the simulations predict single and double strand breaks and base damages, so far all complex lesions are the result of stochastic coincidence from independent processes. Tandem double lesions have not yet been taken into account. Unlike the standard double lesions that are produced by two separate attacks by charged particles or radicals, tandem double lesions are produced by one single attack. The standard double lesions dominate at the high dosage regime. On the other hand, tandem double lesions do not depend on stochastic coincidences and become important at the low dosage regime of particular interest to NASA. Tandem double lesions by hydroxyl radical attack of guanine in isolated DNA have been reported at a dosage of radiation as low as 10 Gy. The formation of two tandem base lesions was found to be linear with the applied doses, a characteristic of tandem lesions. However, tandem double lesions from attack by a charged particle have not been reported.

  15. Radiation flux tables for ICRCCM using the GLA GCM radiation codes

    NASA Technical Reports Server (NTRS)

    HARSHVARDHAN

    1986-01-01

    Tabulated values of longwave and shortwave radiation fluxes and also cooling and heating rates in the atmosphere for standard atmospheric profiles are presented. The radiation codes used in the Goddard general circulation model were employed for the computations. These results were obtained for an international intercomparison projected called Intercomparison of Radiation Codes in Climate Models (ICRCCM).

  16. 10 CFR 20.1101 - Radiation protection programs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Radiation protection programs. 20.1101 Section 20.1101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Radiation Protection Programs § 20.1101 Radiation protection programs. (a) Each licensee shall develop, document, and...

  17. 10 CFR 20.1101 - Radiation protection programs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Radiation protection programs. 20.1101 Section 20.1101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Radiation Protection Programs § 20.1101 Radiation protection programs. (a) Each licensee shall develop, document, and...

  18. 10 CFR 20.1004 - Units of radiation dose.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Units of radiation dose. 20.1004 Section 20.1004 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1004 Units of radiation dose. (a) Definitions. As used in this part, the units of radiation dose are:...

  19. 10 CFR 20.1004 - Units of radiation dose.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Units of radiation dose. 20.1004 Section 20.1004 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1004 Units of radiation dose. (a) Definitions. As used in this part, the units of radiation dose are:...

  20. 10 CFR 20.1101 - Radiation protection programs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Radiation protection programs. 20.1101 Section 20.1101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Radiation Protection Programs § 20.1101 Radiation protection programs. (a) Each licensee shall develop, document, and...

  1. 10 CFR 20.1101 - Radiation protection programs.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Radiation protection programs. 20.1101 Section 20.1101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Radiation Protection Programs § 20.1101 Radiation protection programs. (a) Each licensee shall develop, document, and...

  2. 10 CFR 20.1101 - Radiation protection programs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Radiation protection programs. 20.1101 Section 20.1101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Radiation Protection Programs § 20.1101 Radiation protection programs. (a) Each licensee shall develop, document, and...

  3. 10 CFR 20.1004 - Units of radiation dose.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Units of radiation dose. 20.1004 Section 20.1004 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1004 Units of radiation dose. (a) Definitions. As used in this part, the units of radiation dose are:...

  4. Quality Indicators in Radiation Oncology

    SciTech Connect

    Albert, Jeffrey M.; Das, Prajnan

    2013-03-15

    Oncologic specialty societies and multidisciplinary collaborative groups have dedicated considerable effort to developing evidence-based quality indicators (QIs) to facilitate quality improvement, accreditation, benchmarking, reimbursement, maintenance of certification, and regulatory reporting. In particular, the field of radiation oncology has a long history of organized quality assessment efforts and continues to work toward developing consensus quality standards in the face of continually evolving technologies and standards of care. This report provides a comprehensive review of the current state of quality assessment in radiation oncology. Specifically, this report highlights implications of the healthcare quality movement for radiation oncology and reviews existing efforts to define and measure quality in the field, with focus on dimensions of quality specific to radiation oncology within the “big picture” of oncologic quality assessment efforts.

  5. 40 CFR 192.22 - Supplemental standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Supplemental standards. 192.22 Section 192.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM AND THORIUM MILL TAILINGS...

  6. 40 CFR 192.22 - Supplemental standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Supplemental standards. 192.22 Section 192.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM AND THORIUM MILL TAILINGS...

  7. 40 CFR 192.22 - Supplemental standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Supplemental standards. 192.22 Section 192.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM AND THORIUM MILL TAILINGS...

  8. 40 CFR 192.22 - Supplemental standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Supplemental standards. 192.22 Section 192.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS HEALTH AND ENVIRONMENTAL PROTECTION STANDARDS FOR URANIUM AND THORIUM MILL TAILINGS...

  9. 42 CFR 493.1423 - Standard; Testing personnel qualifications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1423 Standard; Testing personnel... implementing all standard laboratory procedures; (C) The skills required for performing each test method...

  10. Radiation dosimeter

    DOEpatents

    Fox, Richard J.

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  11. Radiation dosimeter

    DOEpatents

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  12. Radiation from Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Sol, H.; Medvedev, M.; Zhang, B.; Nordlund, A.; Frederiksen, J. T.; Fishman, G. J.; Preece, R.

    2008-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electron-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the presence of relativistic jets, instabilities such as the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability create collisionless shocks, which are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons in small-scale magnetic fields has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation, a case of diffusive synchrotron radiation, may be important to understand the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  13. Radiation Hydrodynamics

    SciTech Connect

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is to distinguish

  14. 77 FR 66650 - Proposed Revisions to Radiation Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Proposed Revisions to Radiation Protection AGENCY: Nuclear Regulatory Commission. ACTION: Standard... Nuclear Power Plants: LWR Edition,'' Section 12.1, ``Assuring that Occupational Radiation Exposures Are...

  15. High-definition computed tomography for coronary artery stents: image quality and radiation doses for low voltage (100 kVp) and standard voltage (120 kVp) ECG-triggered scanning.

    PubMed

    Lee, Ji Won; Kim, Chang Won; Lee, Han Cheol; Wu, Ming-Ting; Hwangbo, Lee; Choo, Ki Seok; Kim, June Hong; Lee, Ki-Nam; Kim, Jin You; Jeong, Yeon Joo

    2015-06-01

    The noninvasive assessment of coronary stents by coronary CT angiography (CCTA) is an attractive method. However, the radiation dose associated with CCTA remains a concern for patients. The purpose of this study is to compare the radiation doses and image qualities of CCTA performed using tube voltages of 100 or 120 kVp for the evaluation of coronary stents. After receiving institutional review board approval, 53 consecutive patients with previously implanted stents (101 stents) underwent 64-slice CCTA. Patients were divided into three different protocol groups, namely, prospective ECG triggering at 100 kVp, prospective ECG triggering at 120 kVp, or retrospective gating at 100 kVp. Two reviewers qualitatively scored the quality of the resulting images for coronary stents and determined levels of artificial lumen narrowing (ALN), stent lumen attenuation increase ratio (SAIR), image noise, and radiation dose parameters. No significant differences were found between the three protocol groups concerning qualitative image quality or SAIR. Coronary lumen attenuation and in-stent attenuation of 100 kVp prospective CCTA (P-CCTA) were higher than in the 120 kVp P-CCTA protocol (all Ps < 0.001). Mean ALN was significantly lower for 100 kVp P-CCTA than for 100 kVp retrospective CCTA (R-CCTA, P = 0.007). The mean effective radiation dose was significantly lower (P < 0.001) for 100 kVp P-CCTA (3.3 ± 0.4 mSv) than for the other two protocols (100 kVp R-CCTA 6.7 ± 1.0 mSv, 120 kVp P-CCTA 4.6 ± 1.2 mSv). We conclude that the use of 100 kVp P-CCTA can reduce radiation doses for patients while maintaining the imaging quality of 100 kVp R-CCTA and 120 kVp P-CCTA for the evaluation of coronary stents. PMID:26022439

  16. Polar firn layering in radiative transfer models

    NASA Astrophysics Data System (ADS)

    Linow, Stefanie; Hoerhold, Maria

    2016-04-01

    For many applications in the geosciences, remote sensing is the only feasible method of obtaining data from large areas with limited accessibility. This is especially true for the cryosphere, where light conditions and cloud coverage additionally limit the use of optical sensors. Here, instruments operating at microwave frequencies become important, for instance in polar snow parameters / SWE (snow water equivalent) mapping. However, the interaction between snow and microwave radiation is a complex process and still not fully understood. RT (radiative transfer) models to simulate snow-microwave interaction are available, but they require a number of input parameters such as microstructure and density, which are partly ill-constrained. The layering of snow and firn introduces an additional degree of complexity, as all snow parameters show a strong variability with depth. Many studies on RT modeling of polar firn deal with layer variability by using statistical properties derived from previous measurements, such as the standard deviations of density and microstructure, to configure model input. Here, the variability of microstructure parameters, such as density and particle size, are usually assumed to be independent of each other. However, in the case of the firn pack of the polar ice sheets, we observe that microstructure evolution depends on environmental parameters, such as temperature and snow deposition. Accordingly, density and microstructure evolve together within the snow and firn. Based on CT (computer tomography) microstructure measurements of antarctic firn, we can show that: first, the variability of density and effective grain size are linked and can thus be implemented in the RT models as a coupled set of parameters. Second, the magnitude of layering is captured by the measured standard deviation. Based on high-resolution density measurements of an Antarctic firn core, we study the effect of firn layering at different microwave wavelengths. By means of

  17. Healthful radiation.

    PubMed

    Agard, E T

    1997-01-01

    This title of this article sounds paradoxical to most people because the general public is not fully aware of the many benefits radiation has brought to people's healthcare. Radiation has provided the most effective means of noninvasive diagnosis of many diseases, thus reducing the need for exploratory surgery, at significantly reduced risks. Furthermore, radiotherapy has been effective in treating many diseases without surgical removal of the diseased part. The breast is one excellent example of the benefits of radiation in both diagnosis and treatment with preservation. Yet the public still regards radiation as mysterious and dangerous, while trained experts regard it as beneficial with manageable risks. This article suggests ways of presenting this material to the public in a manner that is interesting and informative. PMID:8972833

  18. Radiation sickness

    MedlinePlus

    ... process so that they do not cause radiation injury to others. This may complicate the first aid and resuscitation process. Check the person's breathing and pulse. Start CPR , if necessary. Remove the person's clothing and place ...

  19. Healthful radiation

    SciTech Connect

    Agard, E.T.

    1997-01-01

    This title of this article sounds paradoxical to most people because the general public is not fully aware of the many benefits radiation has brought to people`s healthcare. Radiation has provided the most effective means of noninvasive diagnosis of many diseases, thus reducing the need for exploratory surgery, at significantly reduced risks. Furthermore, radiotherapy has been effective in treating many diseases without surgical removal of the diseased part. The breast is one excellent example of the benefits of radiation in both diagnosis and treatment with preservation. Yet the public still regards radiation as mysterious and dangerous, while trained experts regard it as beneficial with manageable risks. This article suggests ways of presenting this material to the public in a manner that is interesting and informative. 11 refs.

  20. Radiation Therapy

    MedlinePlus

    ... Radiation (also called x-rays, gamma rays, or photons) either kills tumor cells directly or interferes with ... treatment per day, five days a week, for two to seven weeks. Potiential Side Effects Most people ...