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Sample records for icrp task group

  1. The work of the ICRP dose calculational task group: Issues in implementation of the ICRP dosimetric methodology

    Energy Technology Data Exchange (ETDEWEB)

    Eckerman, K.F. [Oak Ridge National Lab., TN (United States)

    1999-01-01

    Committee 2 of the International Commission on Radiological Protection (ICRP) has had efforts underway to provide the radiation protection community with age-dependent dose coefficients, i.e.g, the dose per unit intake. The Task Group on Dose Calculations, chaired by the author, is responsible for the computation of these coefficients. The Task Group, formed in 1974 to produce ICRP Publication 30, is now international in its membership and its work load has been distributed among the institutions represented on the task group. This paper discusses: (1) recent advances in biokinetic modeling; (2) the recent changes in the dosimetric methodology; (3) the novel computational problems with some of the ICRP quantities; and (4) quality assurance issues which the Task Group has encountered. Potential future developments of the dosimetric framework which might strengthen the relationships with the emerging understanding of radiation risk will also be discussed.

  2. Report of ICRP Task Group 80: 'radiological protection in geological disposal of long-lived solid radioactive waste'.

    Science.gov (United States)

    Weiss, W

    2012-01-01

    The report of International Commission on Radiological Protection (ICRP) Task Group 80 entitled 'Radiological protection in geological disposal of long-lived solid radioactive waste' updates and consolidates previous ICRP recommendations related to solid waste disposal (ICRP Publications 46, 77, and 81). The recommendations given in this report apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the 2007 system of radiological protection, described in ICRP Publication 103, can be applied in the context of the geological disposal of long-lived solid radioactive waste. The report is written as a self-standing document. It describes the different stages in the lifetime of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences application of the protection system over the different phases in the lifetime of a disposal facility is the level of oversight that is present. The level of oversight affects the capability to reduce or avoid exposures. Three main time frames have to be considered for the purpose of radiological protection: time of direct oversight when the disposal facility is being implemented and active oversight is taking place; time of indirect oversight when the disposal facility is sealed and indirect oversight is being exercised to provide additional assurance on behalf of the population; and time of no oversight when oversight is no longer exercised because memory is lost. Copyright © 2012. Published by Elsevier Ltd.

  3. The respiratory tract deposition model proposed by the ICRP Task Group

    Energy Technology Data Exchange (ETDEWEB)

    James, A.C.; Briant, J.K. (Pacific Northwest Lab., Richland, WA (USA)); Stahlhofen, W.; Rudolf, G. (Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Frankfurt am Main (Germany, F.R.). Abt. fuer Biophysikalische Strahlenforschung); Egan, M.J.; Nixon, W. (AEA Safety and Reliability, Culcheth (UK)); Gehr, P. (Bern Univ. (Switzerland). Anatomisches Inst.)

    1990-11-01

    The Task Group has developed a new model of the deposition of inhaled aerosols in each anatomical region of the respiratory tract. The model is used to evaluate the fraction of airborne activity that is deposited in respiratory regions having distinct retention characteristics and clearance pathways: the anterior nares, the extrathoracic airways of the naso- and oropharynx and larynx, the bronchi, the bronchioles, and the alveolated airways of the lung. Drawn from experimental data on total and regional deposition in human subjects, the model is based on extrapolation of these data by means of a detailed theoretical model of aerosol transport and deposition within the lung. The Task Group model applies to all practical conditions, and for aerosol particles and vapors from atomic size up to very coarse aerosols with an activity median aerodynamic diameter of 100 {mu}m. The model is designed to predict regional deposition in different subjects, including adults of either sex, children of various ages, and infants, and also to account for anatomical differences among Caucasian and non-Caucasian subjects. The Task Group model represents aerosol inhalability and regional deposition in different subjects by algebraic expressions of aerosol size, breathing rates, standard lung volumes, and scaling factors for airway dimensions. 35 refs., 13 figs., 2 tabs.

  4. Innovative characteristics of the new dosimetric model for the human respiratory tract studied by the ICRP appointed Task Group of Committee 2

    CERN Document Server

    Melandri, C; Tarroni, G

    1991-01-01

    In 1984, the ICRP appointed a Task Group of Committee 2 to review and revise, as necessary, the current lung dosimetric model. On the basis of the knowledge acquired during the past 20 years, the Task Group's approach has been to review, in depth, the morphology and physiology of the human respiratory tract, inspirability of aerosols and regional deposition of inhaled particles as functions of aerosol size and breathing parameters, clearance of deposited materials, nature and specific sites of damage to the respiratory system caused by inhaled radioactive substances. In the proposed model, clearance from the three regions of the respiratory tract (extrathoracic ET, fast-clearing thoracic T sub f and slow-clearing thoracic T sub s , comprising lymph nodes) is described in terms of competition between the mechanical processes moving particles, which do not depend on the substances, and those of absorption into the blood, determined solely by the material. A Task Group report will also include models for calcula...

  5. ACCEPTABILITY EVALUATION FOR USING ICRP TISSUE WEIGHTING FACTORS TO CALCULATE EFFECTIVE DOSE VALUE FOR SEPARATE GENDER-AGE GROUPS OF RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    L. V. Repin

    2013-01-01

    Full Text Available An article describes radiation risk factors for several gender-age population groups according to Russian statistical and medical-demographic data, evaluates the lethality rate for separate nosologic forms of malignant neoplasms based on Russian cancer registries according to the method of the International Agency for Cancer Research. Relative damage factors are calculated for the gender-age groups under consideration. The tissue weighting factors recommended by ICRP to calculate effective doses are compared with relative damage factors calculated by ICRP for the nominal population and with similar factors calculated in this work for separate population cohorts in theRussian Federation. The significance of differences and the feasibility of using tissue weighting factors adapted for the Russian population in assessing population risks in cohorts of different gender-age compositions have been assessed.

  6. Overview of ICRP Committee 4: application of the Commission's recommendations.

    Science.gov (United States)

    Cool, D A

    2016-06-01

    Committee 4 develops principles and recommendations on radiological protection of people in all exposure situations. The committee meeting in 2014 was hosted by GE Healthcare in Arlington Heights, IL, USA on 27 July-1 August 2014. The programme of work of Committee 4 encompasses several broad areas, including a series of reports covering various aspects of existing exposure situations, leading the efforts of the International Commission on Radiological Protection (ICRP) to update and elaborate recommendations in light of the accident at Fukushima Daiichi nuclear power plant for emergencies and living in contaminated areas, elaborating the underpinnings of the system of radiological protection, and developing focussed reports on specific topic areas in consultation with ICRP's special liaison organisations. Committee 4 has six active Task Groups working on naturally occurring radioactive material; cosmic radiation in aviation; updates of ICRP Publications 109 and 111; ethics of radiological protection; surface and near-surface disposal of solid radioactive waste; and exposures resulting from contaminated sites from past industrial, military, and nuclear activities. In addition, there is a Working Party on tolerability of risk, and ongoing work with the various special liaison organisations of ICRP.

  7. Overview of the ICRP/ICRU adult reference computational phantoms and dose conversion coefficients for external idealised exposures

    CERN Document Server

    Endo, A; Zankl, M; Bolch, W E; Eckerman, K F; Hertel, N E; Hunt, J G; Pelliccioni, M; Schlattl, H; Menzel, H-G

    2014-01-01

    This paper reviews the ICRP Publications 110 and 116 describing the reference computational phantoms and dose conversion coefficients for external exposures. The International Commission on Radiological Protection (ICRP) in its 2007 Recommendations made several revisions to the methods of calculation of the protection quantities. In order to implement these recommendations, the DOCAL task group of the ICRP developed computational phantoms representing the reference adult male and female and then calculated a set of dose conversion coefficients for various types of idealised external exposures. This paper focuses on the dose conversion coefficients for neutrons and investigates their relationship with the conversion coefficients of the protection and operational quantities of ICRP Publication 74. Contributing factors to the differences between these sets of conversion coefficients are discussed in terms of the changes in phantoms employed and the radiation and tissue weighting factors.

  8. The ICRP 2007 recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Streffer, C. [Chairman of ICRP Committee 2, Institute of Science and Ethics, University Duisburg-Essen, 45117 Essen (Germany)

    2007-07-01

    The last comprehensive International Commission on Radiological Protection (ICRP) recommendations have been published in 1991(1). Since that time new data in physics and biology that are relevant for radiological protection have appeared in the scientific literature. Also, the general thinking about safety standards at the workplace as well as for the protection of the public has developed. Thus, a review of the recommendations is needed. However, as the present standards have worked well, these new recommendations should build on the present ones. Only a process of further development should take place allowing for the following key points: - new biological and physical information and trends in the setting of safety standards; - improvement in the presentation of the recommendations; as much stability in the recommendations as is consistent with the new information and environmental aspects will be included. The fundamental principles of radiological protection will remain the same as they have been described in ICRP publication 60(1): Justification: Actions involving new exposures or changes in exposures of individuals have to be justified in advance. A positive net benefit must result. Optimisation: Exposures should be as low as reasonably achievable and should be optimised in relation to with dose constraints. Dose limits: The values will not to be changed from Publication 60. Dose constraints: Development of the concept proposed in Publication 60 will be explained. The ICRP Committees have prepared foundation documents in the fields for which they are responsible and their members have the corresponding expertise. These foundation documents will support the decisions and explain the various statements of the Main Commission in a broader sense. Some of them will be published as Annexes to the recommendations (Annex A: Biological and Epidemiological Information on Health Risks Attributable to Ionising Radiation; Annex B: Quantities used in Radiological

  9. Development of skeletal system for mesh-type ICRP reference adult phantoms

    Science.gov (United States)

    Yeom, Yeon Soo; Wang, Zhao Jun; Tat Nguyen, Thang; Kim, Han Sung; Choi, Chansoo; Han, Min Cheol; Kim, Chan Hyeong; Lee, Jai Ki; Chung, Beom Sun; Zankl, Maria; Petoussi-Henss, Nina; Bolch, Wesley E.; Lee, Choonsik

    2016-10-01

    The reference adult computational phantoms of the international commission on radiological protection (ICRP) described in Publication 110 are voxel-type computational phantoms based on whole-body computed tomography (CT) images of adult male and female patients. The voxel resolutions of these phantoms are in the order of a few millimeters and smaller tissues such as the eye lens, the skin, and the walls of some organs cannot be properly defined in the phantoms, resulting in limitations in dose coefficient calculations for weakly penetrating radiations. In order to address the limitations of the ICRP-110 phantoms, an ICRP Task Group has been recently formulated and the voxel phantoms are now being converted to a high-quality mesh format. As a part of the conversion project, in the present study, the skeleton models, one of the most important and complex organs of the body, were constructed. The constructed skeleton models were then tested by calculating red bone marrow (RBM) and endosteum dose coefficients (DCs) for broad parallel beams of photons and electrons and comparing the calculated values with those of the original ICRP-110 phantoms. The results show that for the photon exposures, there is a generally good agreement in the DCs between the mesh-type phantoms and the original voxel-type ICRP-110 phantoms; that is, the dose discrepancies were less than 7% in all cases except for the 0.03 MeV cases, for which the maximum difference was 14%. On the other hand, for the electron exposures (⩽4 MeV), the DCs of the mesh-type phantoms deviate from those of the ICRP-110 phantoms by up to ~1600 times at 0.03 MeV, which is indeed due to the improvement of the skeletal anatomy of the developed skeleton mesh models.

  10. ICRP recommendations deal with the aftermath of the accident at Fukushima: some preliminary lessons; Las recomendaciones de la ICRP frente a las secuelas del accidente de Fukushima: algunas lecciones preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A. J.

    2012-07-01

    The International Commission on Radiological Protection (ICRP) established the Task Group 84 Initial Lessons Learned from the NPP Accident in Japan vis-a-vis the ICRP System of Radiological Protection. This TG 84 Will compile lessons learned related to the efforts carried out to protect people against radiation exposure during and after the emergency exposure situation caused by the accident. In light of these lessons, the report of the TG will consider the suitability of ad hoc recommendations for the ICRP system of radiological protection for dealing with this type of emergency exposure. This paper describes the author opinion about the main aspects the TG 84 is examining. the intention is not to advance the findings and conclusions of the TG 84, but only to make a review of some of the radiation protection issues the are being discussed. (Author) 23 refs.

  11. Comparisons of calculated respiratory tract deposition of particles based on the NCRP/ITRI model and the new ICRP66 model

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Hsu-Chi; Phalen, R.F. [Univ. of California, Irvine, CA (United States); Chang, I. [Lovelace Inst., Albuquerque, NM (United States)] [and others

    1995-12-01

    The National Council on Radiation Protection and Measurements (NCRP) in the United States and the International Commission on Radiological Protection (ICRP) have been independently reviewing and revising respiratory tract dosimetry models for inhaled radioactive aerosols. The newly proposed NCRP respiratory tract dosimetry model represents a significant change in philosophy from the old ICRP Task Group model. The proposed NCRP model describes respiratory tract deposition, clearance, and dosimetry for radioactive substances inhaled by workers and the general public and is expected to be published soon. In support of the NCRP proposed model, ITRI staff members have been developing computer software. Although this software is still incomplete, the deposition portion has been completed and can be used to calculate inhaled particle deposition within the respiratory tract for particle sizes as small as radon and radon progeny ({approximately} 1 nm) to particles larger than 100 {mu}m. Recently, ICRP published their new dosimetric model for the respiratory tract, ICRP66. Based on ICRP66, the National Radiological Protection Board of the UK developed PC-based software, LUDEP, for calculating particle deposition and internal doses. The purpose of this report is to compare the calculated respiratory tract deposition of particles using the NCRP/ITRI model and the ICRP66 model, under the same particle size distribution and breathing conditions. In summary, the general trends of the deposition curves for the two models were similar.

  12. Translation of dose coefficients From ICRP 53 to ICRP 80.

    Science.gov (United States)

    Moussa, Hanna M; Melanson, Mark A

    2013-02-01

    The effective dose coefficients tabulated in Publication 80 of the International Commission on Radiological Protection (ICRP) for the radiopharmaceuticals addressed earlier in ICRP Publication 53 are based on the tissue weighting factors of ICRP Publication 60. Presumably these values are derived from the tissue dose coefficients tabulated in Publication 53; however, no details regarding their derivation are provided. The tissue weighting factors of Publication 60 explicitly address tissue for which no dose coefficients were tabulated in Publication 53; for example, esophagus and a number of tissues comprising the remainder. In the absence of guidance, the authors have defined a set of rules for the translation and have undertaken an effort to derive the effective dose coefficients of Publication 80 starting with the organ/tissue dose coefficient of Publication 53.

  13. Use of Group Tasks in Teaching English

    OpenAIRE

    Bharti Rathore

    2012-01-01

    In the modern education system, there have been revolutionary changes in education. Technology has changed the overall outlook of schooling. Now teacher is acting as resource person rather than a traditional classroom teacher with chalk and blackboard. Ne Key words: Group task, teaching method, English teaching

  14. Gender, Group Composition, and Task Type in Small Task Groups Using Computer-Mediated Communication.

    Science.gov (United States)

    Savicki, Victor; And Others

    1996-01-01

    To investigate gender effects on computer-mediated communication, undergraduate psychology students were put in small groups (males, females, or mixed) and were assigned feminine content (decision making) and masculine content (intellective) task types. Groups of females, regardless of task, sent more words per e-mail message, were more satisfied…

  15. The revised International Commission on Radiological Protection (ICRP) dosimetric model for the human respiratory tract

    Energy Technology Data Exchange (ETDEWEB)

    Bair, W.J.

    1992-05-01

    A task group has revised the dosimetric model of the respiratory tract used to calculate annual limits on intake of radionuclides. The revised model can be used to project respiratory tract doses for workers and members of the public from airborne radionuclides and to assess past exposures. Doses calculated for specific extrathoracic and thoracic tissues can be adjusted to account for differences in radiosensitivity and summed to yield two values of dose for the respiratory tract that are applicable to the ICRP tissue weighted dosimetry system.

  16. Grouping of Tasks for Cooperative Product Development

    Directory of Open Access Journals (Sweden)

    Takeshi Murayama

    2015-04-01

    Full Text Available A lot of members from various disciplines are involved in the development of complex products, and this brings about large-scale, complicated cooperation among them. Such cooperation causes the following problems: • the time consumption for achieving a consensus among them increases; and • the management of product development becomes difficult. In order to develop the products efficiently, this paper proposes a method for dividing the product development activity into several work groups on an appropriate scale, in each of which some of the members can cooperate with each other without the problems mentioned above. In this method, the product development activity is represented by a directed graph, each of which nodes expresses a task and each of which arcs expresses the flow of data/information between the tasks. ISM (Interpretive Structural Modeling identifies strongly connected sub-graphs, in each of which the members should cooperate with each other. However, if a strongly connected sub-graph is large, the problems mentioned above still exist. In this case, we use Bottleneck Method to divide the sub-graph into several smaller sub-graphs, each of which corresponds to a work group. The effectiveness of the method is demonstrated by showing an example of constructing the work groups.

  17. Incorporation of ICRP-116 eye model into ICRP reference polygonal surface phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thang Tat; Yeom, Yeon Soo; Han, Min Cheol; Wang, Zhao Jun; Kim, Han Sung; Kim, Chan Hyeong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of)

    2015-04-15

    The ICRP adopted a detailed stylized eye model developed by Behrens et al. for evaluation of lens dose coefficients released in ICRP publication 116. However, the dose coefficients were calculated with the stylized eye model modelled into the head of mathematical phantoms not the ICRP reference phantoms, which may cause inconsistency in lens dose assessment. In order to keep consistency in the lens dose assessment, the present study incorporates the ICRP-116 eye model into the currently developing polygonal-mesh-type ICRP reference phantoms which are being converted from the voxel-type ICRP reference phantoms. Then, lens dose values were calculated and compared with those calculated with the mathematical phantom to see how it affects lens doses. The present study incorporated the ICRP-116 eye model into the currently developing polygonal-mesh-type ICRP reference phantoms and showed significant dose differences when compared with ICRP-116 data calculated with the mathematical phantom. We believe that the ICRP reference phantoms including the detailed eye model provide more consistent assessment for eye lens dose.

  18. Analysis of the criteria used by the international commission on radiological protection (ICRP) to justify the setting of numerical reference values. Report No. 277

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, C.; Schneider, T.; Lochard, J.; Crouail, P.

    2005-05-15

    Following its Publication 60, ICRP has proposed nine reports specifying quantified values for dose constraints, action levels, etc. Some 25 values have been identified in all these publications. Since a few years, ICRP is preparing new recommendations in order to provide 'a more coherent and comprehensible system'. The objective of ICRP is to propose to select among the existing quantified values, a few values that could encompass all the other ones. These values are not intended to replace the currently recommended values which remain valid. In this perspective, IRSN has asked CEPN to make a review of all the values introduced in the ICRP publications in order to obtain a broad view of the rationalities proposed by ICRP in the determination of these values. The following Publications of ICRP have been reviewed: - ICRP 60 - 1990 - 1990 Recommendations of ICRP, - ICRP 62 - 1992 - Radiological protection in biomedical research, - ICRP 63 - 1992 - Principles for intervention for protection of the public in a radiological emergency, - ICRP 64 - 1993 - Protection from potential exposure: a conceptual framework, - ICRP 65 - 1993 - Protection against radon-222 at home and at work, - ICRP 68 - 1994 - Dose coefficients for intakes of radionuclides by workers, - ICRP 75 - 1997 - General principles for the radiation protection of workers, - ICRP 77 - 1997 - Radiological protection policy for the disposal of radioactive waste, - ICRP 81 - 2000 - Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste, - ICRP 82 - 2000 - Protection of the public in situations of prolonged radiation exposure. The different quantitative values found in these publications are presented in this report, grouped by type of value: individual dose limits, 'maximum' individual dose, dose constraints, exemption, action and intervention levels. The rationalities proposed by ICRP for setting these values are presented, mainly based on the

  19. ICRP Publication 116—the first ICRP/ICRU application of the male and female adult reference computational phantoms

    CERN Document Server

    Petoussi-Henss, Nina; Eckerman, Keith F; Endo, Akira; Hertel, Nolan; Hunt, John; Menzel, Hans G; Pelliccioni, Maurizio; Schlattl, Helmut; Zankl, Maria

    2014-01-01

    ICRP Publication 116 on `Conversion coefficients for radiological protection quantities for external radiation exposures', provides fluence-to-dose conversion coefficients for organ-absorbed doses and effective dose for various types of external exposures (ICRP 2010 ICRP Publication 116). The publication supersedes the ICRP Publication 74 (ICRP 1996 ICRP Publication 74, ICRU 1998 ICRU Report 57), including new particle types and expanding the energy ranges considered. The coefficients were calculated using the ICRP/ICRU computational phantoms (ICRP 2009 ICRP Publication 110) representing the reference adult male and reference adult female (ICRP 2002 ICRP Publication 89), together with a variety of Monte Carlo codes simulating the radiation transport in the body. Idealized whole-body irradiation from unidirectional and rotational parallel beams as well as isotropic irradiation was considered for a large variety of incident radiations and energy ranges. Comparison of the effective doses with operational quantit...

  20. Overview of ICRP Committee 5: protection of the environment.

    Science.gov (United States)

    Larsson, C-M

    2016-06-01

    Protection of the environment is integral to the system of radiological protection, as outlined in the 2007 Recommendations of the International Commission on Radiological Protection (ICRP, Publication 103). The Commission's activities in this area are mainly pursued by Committee 5 and its associated Task Groups. Publication 91 broadly outlines the approach to radiological protection of the environment, and its alignment with approaches to environmental protection from hazardous substances in general. Publications 108 and 114 provide the cornerstones of the environmental protection system and relevant databases. Publication 124 considers its application in planned, existing, and emergency exposure situations. The system centres on 12 Reference Animals and Plants (RAPs) with broad relevance for environmental protection based on their ubiquity and significance as well as other criteria, as described in Publication 108 The databases comprise general biology of the RAPs, transfer parameters, dose conversion coefficients, and effects data. Derived Consideration Reference Levels (DCRLs) were established for each RAP; a DCRL represents a band of dose rates that might result in some deleterious effects in individuals of that type of RAP. Newly established Task Group 99 will compile the RAP-specific reference information into monographs, with the view of updating information and improving the applicability of the system in different exposure situations. For certain scenarios, more precise and ecosystem-specific protection benchmarks may be justified, which would have to be informed by consideration of representative organisms (i.e. representative of a particular ecosystem and relevant to the specific scenario; Publication 124). Committee 5 will explore this further, making use of a limited number of case studies.

  1. Influences of Task Type on Interaction under Group Work Setting

    Institute of Scientific and Technical Information of China (English)

    刘晓萍

    2005-01-01

    Interaction between learners under group work setting is considered to be signifieantly influenced by task types. The present empirical study was designed to explore interaction characteristics under convergent tasks and divergent tasks from three aspects: language production, meaning negotiation and attention to form while performing different types of tasks. The results reveal that there was significant statistical difference in the total language production between two types of tasks. In terms of the occurrence of meaning negotiation and the extent to which students paid attention to language form, there were no significant difference between the two task types.

  2. Life Cycles of Ad Hoc Task Groups

    Science.gov (United States)

    1983-10-01

    solving development raises some final questions. If groups are normally preoccupied with different issues at different times, if their capabilities change...context, and group across the group’s life cycle? If such modifications normally occur, there could be substantial implications, both for our theoretical...This, and Diane’s impatient question "What are we accomplishing then?" suggest the Iroup’s need to stop trying to coax the attractive first solucion

  3. Group Motivation and Group Task Performance: The Expectancy-Valence Theory Approach.

    Science.gov (United States)

    Nakanishi, Masayuki

    1988-01-01

    Investigated effects of group motivation on group task performance. Created two levels of valence, expectancy and instrumentality. Valence variable reflected on group productivity on unstructured and task persistence measures. Expectancy variable's effect was on task persistence measure. Instrumentality affected group productivity on structured…

  4. Sex Differences in Group Interaction and Task Performance.

    Science.gov (United States)

    Wood, Wendy; And Others

    Research on gender differences in group performance suggests that males excel at brainstorming while females excel at human relations and integration. To investigate the relations among gender, interaction style, and task performance, 264 college students (130 female, 134 male) worked in three person same sex groups on a production task which…

  5. Dynamic Task Performance, Cohesion, and Communications in Human Groups.

    Science.gov (United States)

    Giraldo, Luis Felipe; Passino, Kevin M

    2016-10-01

    In the study of the behavior of human groups, it has been observed that there is a strong interaction between the cohesiveness of the group, its performance when the group has to solve a task, and the patterns of communication between the members of the group. Developing mathematical and computational tools for the analysis and design of task-solving groups that are not only cohesive but also perform well is of importance in social sciences, organizational management, and engineering. In this paper, we model a human group as a dynamical system whose behavior is driven by a task optimization process and the interaction between subsystems that represent the members of the group interconnected according to a given communication network. These interactions are described as attractions and repulsions among members. We show that the dynamics characterized by the proposed mathematical model are qualitatively consistent with those observed in real-human groups, where the key aspect is that the attraction patterns in the group and the commitment to solve the task are not static but change over time. Through a theoretical analysis of the system we provide conditions on the parameters that allow the group to have cohesive behaviors, and Monte Carlo simulations are used to study group dynamics for different sets of parameters, communication topologies, and tasks to solve.

  6. Innovation in Accounting Tasks: Empirical Study in Two Professional Groups

    Directory of Open Access Journals (Sweden)

    Célia Cristina da Silva Vicente

    2016-09-01

    Full Text Available The aim of this study is to contribute to the knowledge on innovation in accounting tasks, from the point of view of two professional groups. Its goals are: evaluating the importance given by the professionals to accounting tasks; identifying whether there is convergence between the two professional groups, regarding the importance of the tasks; examining whether there is an association between the professionals’ individual characteristics and the importance they attach to the tasks. Two professional groups were surveyed: 105 financial officers of the top 500 Portuguese companies; and 412 Chartered Accountants. The results obtained allowed us to conclude that the respondents attach more importance to the traditional tasks, linked to the concept of a monetary-oriented accountant, and less importance to the more innovative tasks, related to business strategy; there is no convergence between the two professional groups in terms of the importance of the accountants’ participation in the strategic tasks. Regarding the association between individual characteristics and the level of importance assigned to the accounting tasks, we found an influence of the following characteristics: gender; academic degree of the professionals; and the institution where that degree was obtained.

  7. Group cohesion, task performance, and the experimenter expectancy effect.

    NARCIS (Netherlands)

    Hoogstraten, J.; Vorst, H.C.M.

    1978-01-01

    Studied the effects of cohesion on task fulfillment and explored the influence of task fulfillment on the initial level of cohesion. Within 4-person groups of undergraduates, cohesion was manipulated successfully by a triple procedure. The level of cohesion was ascertained directly after the inducti

  8. Group Activities in Task-based Communicative Classroom

    Institute of Scientific and Technical Information of China (English)

    邓一琳; 王宇澄

    2005-01-01

    In a task-based communicative classroom, group activities are effective ways to devdop students' 4 basic language skills. However, not all group activities can reach the expected results. English teachers should pay attention to some aspects in organizing a classroom group activity.

  9. ICRP Publication 84 of the ICRP. Pregnancy and medical irradiation; ICRP publication 84 de la CIPR. Grossesse et irradiation medicale

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    In this volume, the ICRP answers questions relative to medical irradiation of pregnant women, that without responses could lead to unappropriated behaviours. It gives the circumstances for a women to be irradiated, the radiation doses delivered by the radiological procedures for a diagnosis and for a therapy. The risks for the fetus and the woman are tackled, their part in the general risks of the pregnancy and the information to give to the future mother. (N.C.)

  10. The Emergence of Individual and Collective Leadership in Task Groups

    DEFF Research Database (Denmark)

    Paunova, Minna

    2015-01-01

    leader emergence in task groups as influenced by individual traits, states, and behaviors. However, current approaches to leadership in groups rely on functional achievement explanations of how collective leadership emerges, influenced by positive states and behaviors. Attention to ascription...... reviews research on individual leader emergence, structured around two identified theoretical mechanisms—one of leadership achievement (i.e., based on functional behaviors) and another of leadership ascription (i.e., based on nominal characteristics). These approaches compete to elucidate individual...

  11. Minimal Groups Increase Young Children's Motivation and Learning on Group-Relevant Tasks

    Science.gov (United States)

    Master, Allison; Walton, Gregory M.

    2013-01-01

    Three experiments ("N" = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the…

  12. Task group to develop list of environmental standards

    Science.gov (United States)

    A new task group designed to develop a list of existing and potential standards that are applicable to environmental contamination problems in soil, rock, and groundwater has been established by the American Society for Testing a n d Materials (ASTM) Subcommittee on Geotechnics of Waste Management. The list currently includes over 60 existing and draft ASTM standards from ASTM committees in the areas of site characterization, construction evaluation, and geosynthetics.

  13. The IUGS/IAGC Task Group on Global Geochemical Baselines

    Institute of Scientific and Technical Information of China (English)

    David B.Smith; Shaun Reeder; Alecos Demetriades

    2012-01-01

    The Task Group on Global Geochemical Baselines,operating under the auspices of both the International Union of Geological Sciences(IUGS) and the International Association of Geochemistry(IAGC),has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements in the Earth's surface or near-surface environment.The database and accompanying element distribution maps represent a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognized and quantified.In order to accomplish this long-term goal,the activities of the Task Group include:(1) developing partnerships with countries conducting broad-scale geochemical mapping studies;(2) providing consultation and training in the form of workshops and short courses;(3) organizing periodic international symposia to foster communication among the geochemical mapping community;(4) developing criteria for certifying those projects whose data are acceptable in a global geochemical database;(5) acting as a repository for data collected by those projects meeting the criteria for standardization;(6) preparing complete metadata for the certified projects;and(7) preparing,ultimately,a global geochemical database.This paper summarizes the history and accomplishments of the Task Group since its first predecessor project was established in 1988.

  14. The IUGS/IAGC Task Group on Global Geochemical Baselines

    Science.gov (United States)

    Smith, David B.; Wang, Xueqiu; Reeder, Shaun; Demetriades, Alecos

    2012-01-01

    The Task Group on Global Geochemical Baselines, operating under the auspices of both the International Union of Geological Sciences (IUGS) and the International Association of Geochemistry (IAGC), has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements in the Earth’s surface or near-surface environment. The database and accompanying element distribution maps represent a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognized and quantified. In order to accomplish this long-term goal, the activities of the Task Group include: (1) developing partnerships with countries conducting broad-scale geochemical mapping studies; (2) providing consultation and training in the form of workshops and short courses; (3) organizing periodic international symposia to foster communication among the geochemical mapping community; (4) developing criteria for certifying those projects whose data are acceptable in a global geochemical database; (5) acting as a repository for data collected by those projects meeting the criteria for standardization; (6) preparing complete metadata for the certified projects; and (7) preparing, ultimately, a global geochemical database. This paper summarizes the history and accomplishments of the Task Group since its first predecessor project was established in 1988.

  15. Minimal groups increase young children's motivation and learning on group-relevant tasks.

    Science.gov (United States)

    Master, Allison; Walton, Gregory M

    2013-01-01

    Three experiments (N = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the "puzzles child" or children in a control condition. Experiment 2 showed that this boost in motivation occurred only when the group was associated with the task. In Experiment 3, children assigned to a minimal group associated with word learning learned more words than children assigned an analogous individual identity. The studies demonstrate that fostering shared motivations may be a powerful means by which to shape young children's academic outcomes.

  16. Introduction to the IWA task group on biofilm modeling.

    Science.gov (United States)

    Noguera, D R; Morgenroth, E

    2004-01-01

    An International Water Association (IWA) Task Group on Biofilm Modeling was created with the purpose of comparatively evaluating different biofilm modeling approaches. The task group developed three benchmark problems for this comparison, and used a diversity of modeling techniques that included analytical, pseudo-analytical, and numerical solutions to the biofilm problems. Models in one, two, and three dimensional domains were also compared. The first benchmark problem (BM1) described a monospecies biofilm growing in a completely mixed reactor environment and had the purpose of comparing the ability of the models to predict substrate fluxes and concentrations for a biofilm system of fixed total biomass and fixed biomass density. The second problem (BM2) represented a situation in which substrate mass transport by convection was influenced by the hydrodynamic conditions of the liquid in contact with the biofilm. The third problem (BM3) was designed to compare the ability of the models to simulate multispecies and multisubstrate biofilms. These three benchmark problems allowed identification of the specific advantages and disadvantages of each modeling approach. A detailed presentation of the comparative analyses for each problem is provided elsewhere in these proceedings.

  17. A Demands-Resources Model of Work Pressure in IT Student Task Groups

    Science.gov (United States)

    Wilson, E. Vance; Sheetz, Steven D.

    2010-01-01

    This paper presents an initial test of the group task demands-resources (GTD-R) model of group task performance among IT students. We theorize that demands and resources in group work influence formation of perceived group work pressure (GWP) and that heightened levels of GWP inhibit group task performance. A prior study identified 11 factors…

  18. Steam Generator Group Project. Task 6. Channel head decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.P.; Clark, R.L.; Reece, W.D.

    1984-08-01

    The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described.

  19. Characteristics of work groups and their relationship with social and task cohesion in student teams.

    Science.gov (United States)

    Forrester, William R; Tashchian, Armen

    2004-08-01

    Results of an exploratory study of relationships between work-group characteristics and the social and task cohesion of 18 business students engaged in team class projects. Regression analysis of scores on workload sharing, team spirit, task flexibility, and team cohesiveness for scales of the Work Group Characteristics Inventory indicated sharing of the workload was significantly associated with both task and social cohesion; team spirit with task cohesion but not social cohesion; and task flexibility with social cohesion but not task cohesion.

  20. Effects of Training on Computer-Mediated Communication in Single or Mixed Gender Small Task Groups.

    Science.gov (United States)

    Savicki, Victor; Kelley, Merle; Ammon, Benjamin

    2002-01-01

    Investigates group gender composition and communication styles in small task groups involved in computer-mediated communication. Describes a study that tried to train small task groups in the use of one communication style and suggests further research in the area of communication training for online task groups. (Author/LRW)

  1. TU-AB-BRD-00: Task Group 100

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk-based quality management program for intensity-modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program. Learning Objectives: Learn how to design a process map for a radiotherapy process Learn how to

  2. Synchrotron radiation shielding design and ICRP radiological protection quantities.

    Science.gov (United States)

    Bassey, Bassey; Moreno, Beatriz; Chapman, Dean

    2015-06-01

    Protection and operational quantities as defined by the International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU) are the two sets of quantities recommended for use in radiological protection for external radiation. Since the '80s, the protection quantities have evolved from the concept of dose equivalent to effective dose equivalent to effective dose, and the associated conversion coefficients have undergone changes. In this work, the influence of three different versions of ICRP photon dose conversion coefficients in the synchrotron radiation shielding calculations of an experimental enclosure has been examined. The versions are effective dose equivalent (ICRP Publication 51), effective dose (ICRP Publication 74), and effective dose (ICRP Publication 116) conversion coefficients. The sources of the synchrotron radiation white beam into the enclosure were a bending magnet, an undulator and a wiggler. The ranges of photons energy from these sources were 10-200 keV for the bending magnet and undulator, and 10-500 keV for the wiggler. The design criterion aimed a radiation leakage less than 0.5 µSv h(-1) from the enclosure. As expected, larger conversion coefficients in ICRP Publication 51 lead to higher calculated dose rates. However, the percentage differences among the calculated dose rates get smaller once shielding is added, and the choice of conversion coefficients set did not affect the final shielding decision.

  3. Fundamental ICRP recommendations at the start of the 21{sup st} century: status of the revision of ICRP publication 60

    Energy Technology Data Exchange (ETDEWEB)

    Valentin, J. [International Commission on Radiological Protection (ICRP), Stockholm (Sweden)

    2002-02-01

    The basic recommendations of the International Commission on Radiological Protection, ICRP, are either re-stated or revised at intervals of about 15 years, most recently in ICRP Publication 60, adopted in 1990. ICRP plan to issue its next recommendations around 2005. Through extensive consultation, the active participation of the radiological protection community was recruited already at the conceptual stage. Based on the vast input received, ICRP is currently preparing draft recommendations. These are likely to emphasise egalitarian values more than utilitarian ones, to be holistic rather than anthropocentric, and to be formatted as a relatively concise set of actual recommendations underpinned by separate publications with more detail. The draft will again be circulated worldwide and comments will be discussed in 2004 with a view to approval of the recommendations in 2005 and publication in 2005 or 2006. Thus, integration into legislation would be possible sometime between 2006 and 2010, say. (orig.) [German] Die grundlegenden Empfehlungen der Iinternationalen Strahlenschutzkommission, ICRP, werden in Abstaenden von ca. 15 Jahren entweder neu festgelegt oder revidiert. Dies geschah zuletzt mit der ICRP Veroeffentlichung 60, die 1990 angenommen wurde. Die ICRP plant die Herausgabe ihrer naechsten Empfehlungen um das Jahr 2005. Durch ausfuehrliche Beratung wurde die aktive Teilnahme der Strahlenschutzgemeinschaft schon im Planungsstadium sichergestellt. Aufgrund der vielen Eingaben, die die ICRP enthalten hat, bereitet sie derzeit den Entwurf der neuen Empfehlungen vor. Wie es scheint, werden diese hauptsaechlich die Gleichheitsgedanken vor den praktischen Werten beruecksichtigen, um eher ganzheitlich als auf den Einzelnen ausgerichtet zu sein, und sie werden als eine relativ zusammenfassende Reihe von aktuellen Empfehlungen herrauskommen, die durch einzelne ausfuehrliche Veroeffentlichungen unterstuetzt werden. Der Entwurf wird wieder weltweit zirkulieren und die

  4. ICRP PUBLICATION 120: Radiological protection in cardiology.

    Science.gov (United States)

    Cousins, C; Miller, D L; Bernardi, G; Rehani, M M; Schofield, P; Vañó, E; Einstein, A J; Geiger, B; Heintz, P; Padovani, R; Sim, K-H

    2013-02-01

    Cardiac nuclear medicine, cardiac computed tomography (CT), interventional cardiology procedures, and electrophysiology procedures are increasing in number and account for an important share of patient radiation exposure in medicine. Complex percutaneous coronary interventions and cardiac electrophysiology procedures are associated with high radiation doses. These procedures can result in patient skin doses that are high enough to cause radiation injury and an increased risk of cancer. Treatment of congenital heart disease in children is of particular concern. Additionally, staff(1) in cardiac catheterisation laboratories may receive high doses of radiation if radiological protection tools are not used properly. The Commission provided recommendations for radiological protection during fluoroscopically guided interventions in Publication 85, for radiological protection in CT in Publications 87 and 102, and for training in radiological protection in Publication 113 (ICRP, 2000b,c, 2007a, 2009). This report is focused specifically on cardiology, and brings together information relevant to cardiology from the Commission's published documents. There is emphasis on those imaging procedures and interventions specific to cardiology. The material and recommendations in the current document have been updated to reflect the most recent recommendations of the Commission. This report provides guidance to assist the cardiologist with justification procedures and optimisation of protection in cardiac CT studies, cardiac nuclear medicine studies, and fluoroscopically guided cardiac interventions. It includes discussions of the biological effects of radiation, principles of radiological protection, protection of staff during fluoroscopically guided interventions, radiological protection training, and establishment of a quality assurance programme for cardiac imaging and intervention. As tissue injury, principally skin injury, is a risk for fluoroscopically guided interventions

  5. The new ICRP respiratory model for radiation protection (ICRP 66) : applications and comparative evaluations; Nuovo modello polmonare della ICRP per radioprotezione (ICRP 66)azioni e confronti con la modellistica precedenteIl

    Energy Technology Data Exchange (ETDEWEB)

    Castellani, C.; Luciani, A. [ENEA, Centro Ricerche Bologna (Italy). Dip. Ambiente

    1996-02-01

    The aim of this report is to present the New ICRP Respiratory Model Tract for Radiological Protection. The model allows considering anatomical and physiological characteristics, giving reference values for children aged 3 months, 1, 5,10, and 15 years for adults; it also takes into account aerosol and gas characteristics. After a general description of the model structure, deposition, clearance and dosimetric models are presented. To compare the new and previous model (ICRP 30), dose coefficients (committed effective dose for unit intake) foe inhalation of radionuclides by workers are calculated considering aerosol granulometries with activity median aerodynamic of 1 and 5 {mu}m, reference values for the respective publications. Dose coefficients and annual limits of intakes concerning respective dose limits (50 and 20 mSv respectively for ICRP 26 and 60) for workers and for members of population in case of dispersion of fission products aerosols, are finally calculated.

  6. A Task Group Practitioner's Response to Waldo and Bauman's Article on Regrouping the Categorization of Group Work.

    Science.gov (United States)

    Keel, Linda P.

    1998-01-01

    Argues that Waldo and Bauman's Goals and Process (GAP) matrix does not include task/work groups. Claims that it is not in the best interest of group work to undo or rework the Association for Specialists in Group Work's four core groups as a model. States that the field of group work needs a commonly shared framework/categorization from which to…

  7. Promoting oral interaction in large groups through task-based learning

    OpenAIRE

    Forero Rocha, Yolima

    2009-01-01

    This research project attempts to show the way a group of five teachers used task-based learning with a group of 50 seventh graders to improve oral interaction. The students belonged to Isabel II School. They took an active part in the implementation of tasks and were asked to answer two questionnaires. Some English classes were observed and recorded; finally, an evaluation was taken by students to test their improvement. Key words: Task-based learning, oral interaction, large groups, hig...

  8. Comparing Pair and Small Group Interactions on Oral Tasks

    Science.gov (United States)

    Lasito,; Storch, Neomy

    2013-01-01

    Although pair and small group activities are commonly used in second language (L2) classrooms, there are very few studies which can inform teachers about whether it is best to have students work in pairs or in small groups. In this study, conducted in a junior high school in Indonesia with learners of English as a Foreign Language (EFL), we…

  9. Comparing Pair and Small Group Interactions on Oral Tasks

    Science.gov (United States)

    Lasito,; Storch, Neomy

    2013-01-01

    Although pair and small group activities are commonly used in second language (L2) classrooms, there are very few studies which can inform teachers about whether it is best to have students work in pairs or in small groups. In this study, conducted in a junior high school in Indonesia with learners of English as a Foreign Language (EFL), we…

  10. Improvement of skeleton conversion in ICRP reference phantom conversion project

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhao Jun; Yeom, Yeon Soo; Thang, Nguyen Tat; Kim, Han Sung; Han, Min Cheol; Kim, Chan Hyeong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of); Kim, Seong Hoon [Dept. of Radiation Oncology, College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2014-11-15

    In the previous skeleton conversion, most bones were directly converted from the ICRP voxel phantoms by using the 3D rendering method whereas several complex-shape bones (cranium, ribs, spines, feet, and hands) were not able to be directly converted. We alternatively employed the corresponding well-defined polygonal models and attempted to adjust them to match the voxel models. However, this approach was unsatisfactory. The shapes of the alternative models were significantly different from those of the voxel models, making it virtually impossible to exactly match the voxel models as shown in Fig. 3 (left). In order to overcome the difficulty in the complex bone conversion, the present study developed a new conversion method and converted these complex bones voxel models of the ICRP male phantom to polygonal models. The present study developed the new conversion method and successfully improved polygonal models for cranium, ribs, and spines for the ICRP male phantom. The new conversion method will be also applied to the complex bone conversion for the ICRP female phantom as well as other complex organ conversion in the future.

  11. 76 FR 21073 - NASA Advisory Council; Task Group of the Science Committee; Meeting

    Science.gov (United States)

    2011-04-14

    ... SPACE ADMINISTRATION NASA Advisory Council; Task Group of the Science Committee; Meeting AGENCY... Administration (NASA) announces a meeting of the Task Group of the NASA Advisory Council (NAC) Science Committee... meeting will take place telephonically and by WebEx. Any interested person may call the USA toll...

  12. 76 FR 26771 - NASA Advisory Council; Task Group of the Science Committee; Meeting

    Science.gov (United States)

    2011-05-09

    ... SPACE ADMINISTRATION NASA Advisory Council; Task Group of the Science Committee; Meeting AGENCY... Administration (NASA) announces a meeting of the Task Group of the NASA Advisory Council (NAC) Science Committee... meeting will take place telephonically and by WebEx. Any interested person may call the USA toll...

  13. The Role of Communication in Group Decision-Making Efficacy: A Task-Contingency Perspective.

    Science.gov (United States)

    Hirokawa, Randy Y.

    1990-01-01

    Argues importance of communication for group decision-making performance and its impact on such performance are function of three task characteristics: structure, information requirement, and evaluation demand. Identifies task circumstances in which group communication can be expected to play role in determining decision-making performance, as…

  14. Report of the task group on fermentation technology.

    CSIR Research Space (South Africa)

    Andrews, RJ

    1978-09-01

    Full Text Available An ad hoc meeting held in Bloemfontein on 29th November, 1976, identified a need for greater contact between South African research groups involved in fermentation technology. The meeting also suggested that the stimulation of research and training...

  15. Development of skeleton model for use in polygonal-mesh-type ICRP reference phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thang Tat; Yeom, Yeon Soo; Han, Min Cheol; Wang, Zhao Jun; Kim, Han Sung; Kim, Chan Hyeong [Dept.of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of)

    2015-04-15

    In order to overcome the limitations, we are currently developing the polygonal-mesh versions of the ICRP reference phantoms by converting the ICRP reference voxel phantoms to polygonal-mesh format. As a part of the ICRP reference phantom conversion project, the present study completed the conversion of skeleton, which is a very complex framework of the body, while addressing some critical problems of the skeleton of the ICRP reference voxel phantoms. The converted skeleton models were also evaluated by comparing dose values of RBM and endosteum with those of the ICRP reference voxel phantoms. As a part of the ICRP reference phantom conversion project, the present study successfully completed skeleton conversion of the ICRP reference adult male and female phantoms to polygonal-mesh format. A comprehensive study of dosimetric effects by the skeleton conversion will be performed in the future.

  16. Preliminary evaluation of specific absorbed fraction (SAF) in ICRP reference phantom conversion project

    Energy Technology Data Exchange (ETDEWEB)

    Thang, Nguyen Tat; Yeom, Yeon Soo; Han, Min Cheol; Jun, Wang Zhao; Kim, Han Sung; Kim, Seong Hoon; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of)

    2014-11-15

    The ICRP reference phantoms, due to their low voxel resolutions, provide incorrect dose values for weakly penetrating radiations. To overcome the limitations, we are now converting the ICRPvoxel phantoms to polygonal surface models in order to develop the polygonal surface version of the ICRP reference phantoms. The ultimate goal of the conversion project is to develop a set of polygonal surface ICRP phantoms which provide correct dose values for weakly penetrating radiations while providing identical dose values with those of the ICRP reference phantoms for highly penetrating radiations. It was confirmed that indeed the current ICRP male polygonal phantom showed generally good agreement with the ICRP male voxel phantom following the objective of the ICRP phantom conversion project. However, relatively large discrepancies were found in the colon doses at 0.03 MeV. We believe that the discrepancies could be sufficiently reduced by adjusting the colon polygonal model to be more similar to the voxel model in the further study.

  17. Perceptual grouping by similarity of surface roughness in haptics: the influence of task difficulty.

    Science.gov (United States)

    Van Aarsen, V; Overvliet, K E

    2016-08-01

    We investigated grouping by similarity of surface roughness in the context of task difficulty. We hypothesized that grouping yields a larger benefit at higher levels of task complexity, because efficient processing is more helpful when more cognitive resources are needed to execute a task. Participants searched for a patch of a different roughness as compared to the distractors in two strips of similar or dissimilar roughness values. We reasoned that if the distractors could be grouped based on similar roughness values, exploration time would be shorter and fewer errors would occur. To manipulate task complexity, we varied task difficulty (high target saliency equalling low task difficulty), and we varied the fingers used to explore the display (two fingers of one hand being more cognitive demanding than two fingers of opposite hands). We found much better performance in the easy condition as compared to the difficult condition (in both error rates and mean search slopes). Moreover, we found a larger effect for the similarity manipulation in the difficult condition as compared to the easy condition. Within the difficult condition, we found a larger effect for the one-hand condition as compared to the two-hand condition. These results show that haptic search is accelerated by the use of grouping by similarity of surface roughness, especially when the task is relatively complex. We conclude that the effect of perceptual grouping is more prominent when more cognitive resources are needed to perform a task.

  18. Effects of Gender and Communication Content on Leadership Emergence in Small Task-Oriented Groups.

    Science.gov (United States)

    Hawkins, Katherine W.

    A study examined the role played by gender and communication content in the leadership emergence process in small, task-oriented groups. Six hours of transcribed group interaction from a sample of the group deliberations of 6 mixed-sex groups of college students (n=27) engaged in a 4-month-long decision-making project served as the database for…

  19. Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

    Science.gov (United States)

    Demeter, S; Applegate, K E; Perez, M

    2016-06-01

    The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations. © The International Society for Prosthetics and Orthotics.

  20. Board advice following publication of the 1990 Recommendations of ICRP

    CERN Document Server

    United Kingdom. At. Energy Res. Establ. Nat. Radiolog. Protect. Board. Harwell

    1991-01-01

    The International Commission on Radiological Protection (ICRP) has published new Recommendations and the board has a statutory duty to advise Government and those with responsibilities for radiation protection on the acceptability to and the applicability in the UK of those Recommendations. The Board wishes to consult widely before finalising the advice which is proposed in this document. In general, the Board endorses the conceptual framework for radiological protection recommended by ICRP. In particular, the distinction between practices and intervention is useful and is consistent with the way in which the Board has presented its recent advice. A major new concept is that of a constraint. The Board believes that the introduction of constraints provides a powerful method for improving protection against ionising radiation. The advice in this consultative document is for maximum generic values of dose constraints for both workers and the public. Finally the Board proposes to endorse the use of the radiologic...

  1. The pernicious effects of unstable work group membership : How work group changes undermine unique task contributions and newcomer acceptance

    NARCIS (Netherlands)

    Rink, Floor; Ellemers, Naomi

    2015-01-01

    This research demonstrates that group membership instability tends to raise self-related concerns that make it less likely that people value and accept constructive task contributions offered by newcomers. In Study 1 (N = 88), unstable group membership heightened self-related concerns. Participants

  2. Comparison of ICRP2 and ICRP30 for estimating the dose and adverse health effects from potential radionuclide releases from a geologic waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Runkle, G.E.; Soldat, J.K.

    1982-01-01

    This paper presents a comparison of the calculated risk of adverse health effects from the radionuclides considered in the inventory of a high-level waste repository using the ICRP2 and ICRP30 internal dosimetry models. A CRPC (cancer risk per curie) index was calculated to compare the two models. The CRPC indices for the ICRP30 model are approximately 2 to 20 times higher than the ICRP2 indices for most radionuclides for ingestion intakes. However, the /sup 237/Np index is approximately 200 times greater for the ICRP30 model and the /sup 228/Ra and /sup 226/Ra indices are approximately 30 to 90 times greater for the ICRP2 model. Generally, there is closer agreement of the CRPC indices for the inhalation intakes. A scenario that considers a U-tube effect and withdrawal of water from wells downdip from the repository was analyzed. This analysis, based on a hypothetical waste disposal site, considered groundwater transport and environmental transport with subsequent uptake by the human via ingestion and inhalation. The ICRP30 risks are higher by approximately 20 at 10,000 years post closure for the ingestion pathway. However, the ICRP2 risks are higher by factors of approximately 2 to 10 at times greater than 50,000 years. Differences in the mathematical modeling assumptions, gut uptakes and other metabolic parameters between the two models account for most of the variability in the risk estimates.

  3. The radiological protection system emanating from the basic recommendations of ICRP-103; El sistema de proteccion radiologica de las recomendaciones basicas de la ICRP-103

    Energy Technology Data Exchange (ETDEWEB)

    Amor Calvo, I.

    2010-07-01

    The International Commission for Radiological Protection has issued its ICRP-103 recommendations, which modify, enlarge upon and update those contained in document ICRP-60. The changes are analysed and evaluated here, along with the actions that will have to be taken by the regulatory authorities to adapt to the novelties introduced. (Author)

  4. Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency

    NARCIS (Netherlands)

    Kirschner, Femke; Paas, Fred; Kirschner, Paul A.

    2009-01-01

    Kirschner, F., Paas, F., & Kirschner, P. (2009). Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency. Computers in Human Behavior, 25, 306-314.

  5. Development of polygonal-surface version of ICRP reference phantoms: Lymphatic node modeling

    Energy Technology Data Exchange (ETDEWEB)

    Thang, Ngyen Tat; Yeom, Yeon Soo; Han, Min Cheol; Kim, Chan Hyeong [Hanyang University, Seoul (Korea, Republic of)

    2014-04-15

    Among radiosensitive organs/tissues considered in ICRP Publication 103, lymphatic nodes are many small size tissues and widely distributed in the ICRP reference phantoms. It is difficult to directly convert lymphatic nodes of ICRP reference voxel phantoms to polygonal surfaces. Furthermore, in the ICRP reference phantoms lymphatic nodes were manually drawn only in six lymphatic node regions and the reference number of lymphatic nodes reported in ICRP Publication 89 was not considered. To address aforementioned limitations, the present study developed a new lymphatic node modeling method for the polygonal-surface version of ICRP reference phantoms. By using the developed method, lymphatic nodes were modelled in the preliminary version of ICRP male polygonal-surface phantom. Then, lymphatic node dose values were calculated and compared with those of the ICRP reference male voxel phantom to validate the developed modeling method. The present study developed the new lymphatic node modeling method and successfully modeled lymphatic nodes in the preliminary version of the ICRP male polygonal-surface phantom. From the results, it was demonstrated that the developed modeling method can be used to model lymphatic nodes in polygonal-surface version of ICRP reference phantoms.

  6. Validating an important aspect of the new ICRP biokinetic model of thorium.

    Science.gov (United States)

    Roth, P; Höllriegl, V; Li, W B; Oeh, U; Schramel, P

    2005-03-01

    The daily urinary excretion of Th (Th) was estimated in 11 adult German subjects who were not exposed occupationally to thorium and its related compounds. Thirty-one urine samples were collected over 24-h periods on different occasions from these subjects and were analyzed using high resolution sector field inductively coupled plasma mass spectrometry (HR-SF-ICP-MS). Using this instrument a limit of detection of 20 pg L for thorium in the reagent blank was achieved. The median (mean) daily urinary thorium excretion was obtained as 1.0 (1.8) ng. This was in good agreement with the mean value of 1.5 ng Th (6 microBq) reported by another group for German population, but is significantly lower in comparison to the daily excretion range of 3.6 to 105 ng reported from other countries. The expected daily urinary excretion of thorium for the adult German population was also calculated by applying the new ICRP biokinetic model of thorium assuming reference intake values. The expected urinary thorium excretion rate for this age group is about 0.1 ng per day. Even if a small contribution from the inhalation is considered, the calculated value will be much lower than the measured values. The reason for the disagreement appears to be the use of a low gastrointestinal absorption factor (f1) of 5 x 10 in the ICRP model. Based on the present study, a higher f1 factor might be proposed separately for dietary incorporated thorium.

  7. Test-Retest Reliability in fMRI of Language: Group and Task Effects

    Science.gov (United States)

    Chen, E. Elinor; Small, Steven L.

    2007-01-01

    This paper explores how the test-retest reliability is modulated by different groups of participants and experimental tasks. A group of 12 healthy participants and a group of nine stroke patients performed the same language imaging experiment twice, test and retest, on different days. The experiment consists of four conditions, one audio condition…

  8. Positioning during Group Work on a Novel Task in Algebra II

    Science.gov (United States)

    DeJarnette, Anna F.; González, Gloriana

    2015-01-01

    Given the prominence of group work in mathematics education policy and curricular materials, it is important to understand how students make sense of mathematics during group work. We applied techniques from Systemic Functional Linguistics to examine how students positioned themselves during group work on a novel task in Algebra II classes. We…

  9. The ICRP protection policy. The conceptual framework of radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, R.H. [National Radiological Protection Board, Chilton, Didcot (United Kingdom)

    1997-08-01

    Within twelve months of the discovery of X-rays in 1895, it was reported that large doses of radioation were harmful to living human tissues. The first radiation protection standards were set to avoid the early effects of acute irradiation. By the 1950s, evidence was mounting for late somatic effects - mainly a small excess of cancers - in irradiated populations. In the late 1980s, sufficient human epidemiological and had been accumulated to allow a comprehensive assessment of carcinogenic radiation risks following the delivery of moderately high doses. Workers and the public are exposed to lower doses and dose-rates that the groups from whom good data are available so that risks have had to be estimated for protection purposes. However, in the 1990s, some confirmation of these risk factors has been derived from occupationally exposed populations. If an estimate is made of the risk per unit dose, then in order to restrict the doses that people receive, levels of acceptable risk must be estabilished for both workers and the public. There has been and continues to be a debate about the definitions of `acceptable`, `unacceptable` and `tolerable` and the attributing of numerical values to these definitions. The values differ as between normal operations, the potential for accidents, recovery of contaminated land, and for workers or the public. This paper discusses the issues involved in the quantification of these terms and the way in which the International Commission on Radiological Protection has used acceptability of risk in setting its new standards for protection. (orig.) [Deutsch] Innerhalb von zwoelf Monaten nach der Entdeckung der radioaktiven Strahlung im Jahre 1895 wurde deren schaedigende Wirkung auf menschliche Organismen festgestellt. Die ersten Strahlenschutzstandards wurden aufgestellt, um Schaeden durch eine unmittelbare Bestrahlung vorzubeugen. In den fuenfziger Jahren wurden Gesundheitsrisiken von Strahlung ausgesetzten Bevoelkerungsschichten

  10. The Effects of Dual Task on Healthy Adults Balance Index in Age and Gender groups

    Directory of Open Access Journals (Sweden)

    Sona Abedi

    2012-10-01

    Full Text Available Background and Aim: Falls are the leading cause of accidental death among older adults. Recent studies have demonstrated that an impaired ability to maintain balance while simultaneously performing cognitive tasks is associated with increased rates of adverse outcomes, such as falls in elderly people. Because interventions designed to improve dual-task balance performance have the potential to reduce falling rate and functional decline, they are a critical health care need.Material & Methods: 60 healthy adults in four equal groups (mean age in: young men=22.1±1.9, old men =68.3±4.1, young women =22.6±1.8, old women =66.9±2.6 participated in this study. All subjects experienced four test conditions including: single- task with eyes open (O1, single- task with eyes closed (C1, dual-task with eyes open (O2 and dual-task with eyes closed (C2. Postural task in this study included standing on 8 instability level of biodex balance SD machine plate and cognitive task was backward counting by three.Results: balance index mean in older group was significantly higher in comparison with young group in all test conditions (O1 P=.000, C1 P=.003, O2 P=.000, C2 P=.000. There are not any significant differences between gender groups balance index mean, in test conditions. In Young women group O2 overall (OL, antroposterior (AP and mediolateral (ML balance indexes means were significantly higher than corresponding amounts in C2 (OL P=.014, AP P=.030, ML P=.017. In old women group C2 ML balance index mean was significantly higher than O2 ML balance index mean (P=.034. There are not significant differences between single- and dual-task conditions in other within group comparisons.Conclusion: In young men, young women and old women balance index means are different between single and dual eyes closed condition. Older adults balance index in single- and dual-task conditions is higher than young adults balance index. There is not any difference between men and

  11. Vocal turn-taking patterns in groups of children performing collaborative tasks: an exploratory study

    NARCIS (Netherlands)

    Kim, Jaebok; Truong, Khiet Phuong; Charisi, Vasiliki; Zaga, Cristina; Lohse, M.; Heylen, Dirk K.J.; Evers, Vanessa

    Since children (5-9 years old) are still developing their emotional and social skills, their social interactional behaviors in small groups might differ from adults' interactional behaviors. In order to develop a robot that is able to support children performing collaborative tasks in small groups,

  12. A review of the work of the Task Group on Behind Armour Blunt Trauma

    NARCIS (Netherlands)

    Anderson, I.B.; Knudsen, P.J.T.; Sarron, J.C.; Bree, J.L.M.J. van; Gotts, P.; Waclawik, S.

    2002-01-01

    Over the past four years several countries and national laboratories have collaborated within the North Atlantic Treaty Organization’s Research and Technology Organization as a Task Group. The purpose was to continue the research of an earlier NATO sponsored group and so explain the pathophysiology

  13. Quality assurance for nonradiographic radiotherapy localization and positioning systems: report of Task Group 147.

    Science.gov (United States)

    Willoughby, Twyla; Lehmann, Joerg; Bencomo, Jose A; Jani, Shirish K; Santanam, Lakshmi; Sethi, Anil; Solberg, Timothy D; Tome, Wolfgang A; Waldron, Timothy J

    2012-04-01

    New technologies continue to be developed to improve the practice of radiation therapy. As several of these technologies have been implemented clinically, the Therapy Committee and the Quality Assurance and Outcomes Improvement Subcommittee of the American Association of Physicists in Medicine commissioned Task Group 147 to review the current nonradiographic technologies used for localization and tracking in radiotherapy. The specific charge of this task group was to make recommendations about the use of nonradiographic methods of localization, specifically; radiofrequency, infrared, laser, and video based patient localization and monitoring systems. The charge of this task group was to review the current use of these technologies and to write quality assurance guidelines for the use of these technologies in the clinical setting. Recommendations include testing of equipment for initial installation as well as ongoing quality assurance. As the equipment included in this task group continues to evolve, both in the type and sophistication of technology and in level of integration with treatment devices, some of the details of how one would conduct such testing will also continue to evolve. This task group, therefore, is focused on providing recommendations on the use of this equipment rather than on the equipment itself, and should be adaptable to each user's situation in helping develop a comprehensive quality assurance program.

  14. Hierarchical Clustering Multi-Task Learning for Joint Human Action Grouping and Recognition.

    Science.gov (United States)

    Liu, An-An; Su, Yu-Ting; Nie, Wei-Zhi; Kankanhalli, Mohan

    2017-01-01

    This paper proposes a hierarchical clustering multi-task learning (HC-MTL) method for joint human action grouping and recognition. Specifically, we formulate the objective function into the group-wise least square loss regularized by low rank and sparsity with respect to two latent variables, model parameters and grouping information, for joint optimization. To handle this non-convex optimization, we decompose it into two sub-tasks, multi-task learning and task relatedness discovery. First, we convert this non-convex objective function into the convex formulation by fixing the latent grouping information. This new objective function focuses on multi-task learning by strengthening the shared-action relationship and action-specific feature learning. Second, we leverage the learned model parameters for the task relatedness measure and clustering. In this way, HC-MTL can attain both optimal action models and group discovery by alternating iteratively. The proposed method is validated on three kinds of challenging datasets, including six realistic action datasets (Hollywood2, YouTube, UCF Sports, UCF50, HMDB51 & UCF101), two constrained datasets (KTH & TJU), and two multi-view datasets (MV-TJU & IXMAS). The extensive experimental results show that: 1) HC-MTL can produce competing performances to the state of the arts for action recognition and grouping; 2) HC-MTL can overcome the difficulty in heuristic action grouping simply based on human knowledge; 3) HC-MTL can avoid the possible inconsistency between the subjective action grouping depending on human knowledge and objective action grouping based on the feature subspace distributions of multiple actions. Comparison with the popular clustered multi-task learning further reveals that the discovered latent relatedness by HC-MTL aids inducing the group-wise multi-task learning and boosts the performance. To the best of our knowledge, ours is the first work that breaks the assumption that all actions are either

  15. Gender and Group Composition in Small Task Groups Using Computer-Mediated Communication.

    Science.gov (United States)

    Savicki, Victor; And Others

    1996-01-01

    Gender and group composition variables in a computer-mediated communication context are examined. Subjects were 36 undergraduate male and female psychology students. Findings are analyzed in terms of choice of language; participation; satisfaction; and interpersonal conflict. Ten tables present study results. (Author/AEF)

  16. Interactional Concerns in Implementing Group Tasks: Addressing Silence, Dominance, and Off-Task Talk in an Academic Writing Class

    Science.gov (United States)

    Sharma, Bal Krishna

    2015-01-01

    This study investigates the teacher role in mediating the task and the learner in an advanced academic writing class. Having identified three verbal (non-)participation patterns of students in collaborative tasks (silence, dominance, and off-task talk), I examine how these interactional concerns are understood and addressed by English as a second…

  17. Interactional Concerns in Implementing Group Tasks: Addressing Silence, Dominance, and Off-Task Talk in an Academic Writing Class

    Science.gov (United States)

    Sharma, Bal Krishna

    2015-01-01

    This study investigates the teacher role in mediating the task and the learner in an advanced academic writing class. Having identified three verbal (non-)participation patterns of students in collaborative tasks (silence, dominance, and off-task talk), I examine how these interactional concerns are understood and addressed by English as a second…

  18. IEA SHC Task 42/ECES Annex 29–Working Group B

    DEFF Research Database (Denmark)

    van Helden, Wim; Yamaha, Motoi; Rathgeber, Christoph

    2016-01-01

    The IEA joint Task 42 / Annex 29 is aimed at developing compact thermal energy storage materials and systems. In Working Group B, experts are working on the development of compact thermal energy storage applications, in the areas cooling, domestic heating and hot water and industry. The majority ...

  19. Task Groups in the School Setting: Promoting Children's Social and Emotional Learning

    Science.gov (United States)

    Van Velsor, Patricia

    2009-01-01

    Through social and emotional learning (SEL), individuals develop skill in negotiating relationships successfully and expressing emotions appropriately. The socially and emotionally intelligent child reaps benefits in school and later life. Counselors are best qualified to promote children's SEL and the task group in the classroom provides an…

  20. QA for helical tomotherapy: report of the AAPM Task Group 148.

    Science.gov (United States)

    Langen, Katja M; Papanikolaou, Niko; Balog, John; Crilly, Richard; Followill, David; Goddu, S Murty; Grant, Walter; Olivera, Gustavo; Ramsey, Chester R; Shi, Chengyu

    2010-09-01

    Helical tomotherapy is a relatively new modality with integrated treatment planning and delivery hardware for radiation therapy treatments. In view of the uniqueness of the hardware design of the helical tomotherapy unit and its implications in routine quality assurance, the Therapy Physics Committee of the American Association of Physicists in Medicine commissioned Task Group 148 to review this modality and make recommendations for quality assurance related methodologies. The specific objectives of this Task Group are: (a) To discuss quality assurance techniques, frequencies, and tolerances and (b) discuss dosimetric verification techniques applicable to this unit. This report summarizes the findings of the Task Group and aims to provide the practicing clinical medical physicist with the insight into the technology that is necessary to establish an independent and comprehensive quality assurance program for a helical tomotherapy unit. The emphasis of the report is to describe the rationale for the proposed QA program and to provide example tests that can be performed, drawing from the collective experience of the task group members and the published literature. It is expected that as technology continues to evolve, so will the test procedures that may be used in the future to perform comprehensive quality assurance for helical tomotherapy units.

  1. An Agent-Based Model of Status Construction in Task Focused Groups

    NARCIS (Netherlands)

    Grow, André; Flache, Andreas; Wittek, Rafael

    2015-01-01

    Status beliefs link social distinctions, such as gender and race, to assumptions about competence and social worth. Recent modeling work in status construction theory suggests that interactions in small, task focused groups can lead to the spontaneous emergence and diffusion of such beliefs in large

  2. Attention to Form in Collaborative Writing Tasks: Comparing Pair and Small Group Interaction

    Science.gov (United States)

    Dobao, Ana Fernández

    2014-01-01

    This study examines the opportunities that a collaborative writing task completed in pairs and in small groups offers for attention to form. Previous research suggests that collaborative writing activities encourage learners to focus their attention on language and to collaborate in the resolution of their language-related problems in ways that…

  3. National facilities study. Volume 2: Task group on aeronautical research and development facilities report

    Science.gov (United States)

    1994-01-01

    The Task Group on Aeronautics R&D Facilities examined the status and requirements for aeronautics facilities against the competitive need. Emphasis was placed on ground-based facilities for subsonic, supersonic and hypersonic aerodynamics, and propulsion. Subsonic and transonic wind tunnels were judged to be most critical and of highest priority. Results of the study are presented.

  4. A Consensus-Based Grouping Algorithm for Multi-agent Cooperative Task Allocation with Complex Requirements.

    Science.gov (United States)

    Hunt, Simon; Meng, Qinggang; Hinde, Chris; Huang, Tingwen

    2014-01-01

    This paper looks at consensus algorithms for agent cooperation with unmanned aerial vehicles. The foundation is the consensus-based bundle algorithm, which is extended to allow multi-agent tasks requiring agents to cooperate in completing individual tasks. Inspiration is taken from the cognitive behaviours of eusocial animals for cooperation and improved assignments. Using the behaviours observed in bees and ants inspires decentralised algorithms for groups of agents to adapt to changing task demand. Further extensions are provided to improve task complexity handling by the agents with added equipment requirements and task dependencies. We address the problems of handling these challenges and improve the efficiency of the algorithm for these requirements, whilst decreasing the communication cost with a new data structure. The proposed algorithm converges to a conflict-free, feasible solution of which previous algorithms are unable to account for. Furthermore, the algorithm takes into account heterogeneous agents, deadlocking and a method to store assignments for a dynamical environment. Simulation results demonstrate reduced data usage and communication time to come to a consensus on multi-agent tasks.

  5. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats.

    Science.gov (United States)

    Hulgard, Katrine; Ratcliffe, John M

    2016-02-09

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group.

  6. Communication Effects on Small Group Decision-Making: Homogeneity and Task as Moderators of the Communication-Performance Relationship.

    Science.gov (United States)

    Salazar, Abran J.

    1997-01-01

    Investigates circumstances under which communication variables contribute significantly to the constitution of group decisions. Postulates two variables, homogeneity of task-relevant information possessed by group members and task demonstrability, to moderate the impact of communication and group member ability on quality of group outcomes.…

  7. Role of Gestalt grouping in selective attention: evidence from the Stroop task.

    Science.gov (United States)

    Lamers, Martijn J M; Roelofs, Ardi

    2007-11-01

    Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover, removing both the color and the word simultaneously reduces interference less than does removing the color only (La Heij, van der Heijden, & Plooij, 2001). These findings could also be attributed to Gestalt grouping principles, such as common fate. We report three experiments in which the role of Gestalt grouping was further investigated. Experiment I replicated the reduced interference, using words and color patches. In Experiment 2, the color patch was not removed but only repositioned (Gestalt grouping in selective attention.

  8. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats

    DEFF Research Database (Denmark)

    Hulgard, K.; Ratcliffe, J. M.

    2016-01-01

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach...... to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking...... stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially...

  9. National facilities study. Volume 5: Space research and development facilities task group

    Science.gov (United States)

    1994-01-01

    With the beginnings of the U.S. space program, there was a pressing need to develop facilities that could support the technology research and development, testing, and operations of evolving space systems. Redundancy in facilities that was once and advantage in providing flexibility and schedule accommodation is instead fast becoming a burden on scarce resources. As a result, there is a clear perception in many sectors that the U.S. has many space R&D facilities that are under-utilized and which are no longer cost-effective to maintain. At the same time, it is clear that the U.S. continues to possess many space R&D facilities which are the best -- or among the best -- in the world. In order to remain world class in key areas, careful assessment of current capabilities and planning for new facilities is needed. The National Facility Study (NFS) was initiated in 1992 to develop a comprehensive and integrated long-term plan for future aerospace facilities that meets current and projected government and commercial needs. In order to assess the nation's capability to support space research and development (R&D), a Space R&D Task Group was formed. The Task Group was co-chaired by NASA and DOD. The Task Group formed four major, technologically- and functionally- oriented working groups: Human and Machine Operations; Information and Communications; Propulsion and Power; and Materials, Structures, and Flight Dynamics. In addition to these groups, three supporting working groups were formed: Systems Engineering and Requirements; Strategy and Policy; and Costing Analysis. The Space R&D Task Group examined several hundred facilities against the template of a baseline mission and requirements model (developed in common with the Space Operations Task Group) and a set of excursions from the baseline. The model and excursions are described in Volume 3 of the NFS final report. In addition, as a part of the effort, the group examined key strategic issues associated with space R

  10. Infinite Shift-invariant Grouped Multi-task Learning for Gaussian Processes

    CERN Document Server

    Wang, Yuyang; Protopapas, Pavlos

    2012-01-01

    Multi-task learning leverages shared information among data sets to improve the learning performance of individual tasks. The paper applies this framework for data where each task is a phase-shifted periodic time series. In particular, we develop a novel Bayesian nonparametric model capturing a mixture of Gaussian processes where each task is a sum of a group-specific function and a component capturing individual variation, in addition to each task being phase shifted. We develop an efficient \\textsc{em} algorithm to learn the parameters of the model. As a special case we obtain the Gaussian mixture model and \\textsc{em} algorithm for phased-shifted periodic time series. Furthermore, we extend the proposed model by using a Dirichlet Process prior and thereby leading to an infinite mixture model that is capable of doing automatic model selection. A Variational Bayesian approach is developed for inference in this model. Experiments in regression, classification and class discovery demonstrate the performance of...

  11. Cortisol responses to a group public speaking task for adolescents: variations by age, gender, and race.

    Science.gov (United States)

    Hostinar, Camelia E; McQuillan, Mollie T; Mirous, Heather J; Grant, Kathryn E; Adam, Emma K

    2014-12-01

    Laboratory social stress tests involving public speaking challenges are widely used for eliciting an acute stress response in older children, adolescents, and adults. Recently, a group protocol for a social stress test (the Trier Social Stress Test for Groups, TSST-G) was shown to be effective in adults and is dramatically less time-consuming and resource-intensive compared to the single-subject version of the task. The present study sought to test the feasibility and effectiveness of an adapted group public speaking task conducted with a racially diverse, urban sample of U.S. adolescents (N=191; 52.4% female) between the ages of 11 and 18 (M=14.4 years, SD=1.93). Analyses revealed that this Group Public Speaking Task for Adolescents (GPST-A) provoked a significant increase in cortisol production (on average, approximately 60% above baseline) and in self-reported negative affect, while at the same time avoiding excessive stress responses that would raise ethical concerns or provoke substantial participant attrition. Approximately 63.4% of participants exhibited an increase in cortisol levels in response to the task, with 59.2% of the total sample showing a 10% or greater increase from baseline. Results also suggested that groups of five adolescents might be ideal for achieving more uniform cortisol responses across various serial positions for speech delivery. Basal cortisol levels increased with age and participants belonging to U.S. national minorities tended to have either lower basal cortisol or diminished cortisol reactivity compared to non-Hispanic Whites. This protocol facilitates the recruitment of larger sample sizes compared to prior research and may show great utility in answering new questions about adolescent stress reactivity and development.

  12. ON NEW RECOMMENDATIONS OF THE INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION (ICRP PART 1: RADIATION SAFETY BASIS.

    Directory of Open Access Journals (Sweden)

    I. K. Romanovich

    2008-01-01

    Full Text Available ICRP Publication 103 was issued in November, 2007.  The new approaches of ICRP to maintenance radiation protection are formulated in this publication. These recommendations are the further development of the previous document - the ICRP 60 Publication. The new data, allowing to specify or reconsider quantitative protection criteria have appeared after 1990. ICRP suggests to use a number of new ideas and concepts as base principles of radiation protection maintenance. Taking into account that the standard of radiating safety of Russia (RSSR [3] which is used in Russian Federation since 1999 have been developed in a view of the 60 publication and other international publications, and also in a view of national experience of radiation safety maintenance. It is very important to study and comprehend innovations of ICRP, and also to estimate an opportunity and an acceptability of their realization by development of new edition of RSSR. In the first and second parts of present article the review of the new ICRP Recommendations and some judgments concerning an opportunity of the refraction of Publication ICRP positions in the future RSSR is given.

  13. Incorporation of current ICRP recommendations in the GENMOD internal dosimetry code

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, R.B.; Dunford, D.W

    1998-07-01

    Genmod was initially developed by Johnson and Dunford to perform internal dose assessments and evaluate bioassay data using the methods described by the ICRP in Publications 26 and 30. The mainframe code, Genmod-MF was modified to implement the ICRP's new lung model, new weighting factors and new values for specific effective energy (SEE) available from M. Cristy and K.F. Eckerman, Oak Ridge Laboratories. Organ equivalent doses and effective dose for selected radionuclides employing the ICRP 30 general organ model have been verified, for ingestion and inhalation cases, against current ICRP publications, the internal dosimetry code LUDEP and mainframe codes. The PC version of Genmod has been rewritten to operate under the MS-Windows 95 system. A demonstration package has been developed that calculates doses and provides graphics for radionuclides where the ICRP's general organ model is appropriate. Data will be presented showing the differences and similarities in dose conversion factors using the ICRP 26/30 methodology and recommendations in ICRP Publication 60 onwards. (author)

  14. Incorporation of current ICRP recommendations in the Genmod internal dosimetry code

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, R.B.; Dunford, D.W

    1998-07-01

    Genmod was initially developed by Johnson and Dunford to perform internal dose assessments and evaluate bioassay data using the methods described by the ICRP in Publications 26 and 30. The mainframe code, Genmod-MF was modified to implement the ICRP's new lung model, new weighting factors and new values for specific effective energy (SEE) available from M. Cristy and K. F. Eckerman, Oak Ridge Laboratories. Organ equivalent doses and effective dose for selected radionuclides employing the ICRP 30 general organ model have been verified, for ingestion and inhalation cases, against current ICRP publications, the internal dosimetry code LUDEP and mainframe codes. The PC version of Genmod has been rewritten to operate under the MS-Windows95 system. A demonstration package has been developed that calculates doses and provides graphics for radionuclides where the ICRP's general organ model is appropriate. Data will be presented showing the differences and similarities in dose conversion factors using the ICRP 26/30 methodology and recommendations in ICRP Publication 60 onwards. (author)

  15. Report of the Task Group on Electrical Safety of Department of Energy facilities

    Energy Technology Data Exchange (ETDEWEB)

    None

    1993-01-01

    The Task Group on Electrical Safety at DOE Facilities (Task Group), which was formally established on October 27, 1992. The Task Group reviewed the electrical safety-related occurrence history of, and conducted field visits to, seven DOE sites chosen to represent a cross section of the Department`s electrical safety activities. The purpose of the field visits was to review, firsthand, electrical safety programs and practices and to gain greater insight to the root causes and corrective actions taken for recently reported incidents. The electrical safety environment of the DOE complex is extremely varied, ranging from common office and industrial electrical systems to large high-voltage power distribution systems (commercial transmission line systems). It includes high-voltage/high-power systems associated with research programs such as linear accelerators and experimental fusion confinement systems. Age, condition, and magnitude of the facilities also varies, with facilities dating from the Manhattan Project, during World War II, to the most modem complexes. The complex is populated by Federal (DOE and other agencies) and contractor employees engaged in a wide variety of occupations and activities in office, research and development, and industrial settings. The sites visited included all of these variations and are considered by the Task Group to offer a valid representation of the Department`s electrical safety issues. The sites visited were Oak Ridge National Laboratory (ORNL), Stanford Linear Accelerator Center (SLAC), Idaho National Engineering Laboratory (INEL), Nevada Test Site (NTS), Savannah River Site (SRS), Hanford Reservation (Hanford), and the Uranium Mill Tailings Remedial Action Project (UMTRA) located at Grand Junction, Colorado.

  16. User's manual to the ICRP Code: a series of computer programs to perform dosimetric calculations for the ICRP Committee 2 report

    Energy Technology Data Exchange (ETDEWEB)

    Watson, S.B.; Ford, M.R.

    1980-02-01

    A computer code has been developed that implements the recommendations of ICRP Committee 2 for computing limits for occupational exposure of radionuclides. The purpose of this report is to describe the various modules of the computer code and to present a description of the methods and criteria used to compute the tables published in the Committee 2 report. The computer code contains three modules of which: (1) one computes specific effective energy; (2) one calculates cumulated activity; and (3) one computes dose and the series of ICRP tables. The description of the first two modules emphasizes the new ICRP Committee 2 recommendations in computing specific effective energy and cumulated activity. For the third module, the complex criteria are discussed for calculating the tables of committed dose equivalent, weighted committed dose equivalents, annual limit of intake, and derived air concentration.

  17. Comparison in the calculation of committed effective dose using the ICRP 30 and ICRP 60 models for a repeated incorporation by inhalation of I-125; Comparacion en el calculo de la dosis efectiva comprometida usando los modelos del ICRP 30 y del ICRP 60 para una incorporacion repetida por inhalacion de I-125

    Energy Technology Data Exchange (ETDEWEB)

    Carreno P, A.L.; Cortes C, A. [CNSNS, Dr. Barragan 779, Col. Narvarte, Mexico D.F. (Mexico); Alonso V, G.; Serrano P, F. [IPN, Edificio de Fisica Avanzada Zacatenco, 07300 Mexico D.F. (Mexico)

    2005-07-01

    Presently work, a comparison in the calculation of committed effective dose using the models of the ICRP 30 and those of the ICRP 60 for the analysis of internal dose due to repeated incorporation of I-125 is shown. The estimations of incorporated activity are obtained starting from the proportionate data for an exercise of inter comparison, with which it should be determined the internal dose later on. For to estimate the initial activity incorporated by repeated dose was assumed that this it was given through of multiple individual incorporations which happened in the middle points of the monitoring periods. The results using the models of the ICRP 30 and of the ICRP 60 are compared and the causes of the differences are analyzed. (Author)

  18. Evaluation of the effect of change in the radiosensitive tissue weights listed in the ICRP in estimate of effective dose

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Jose W.; Leal Neto, Viriato; Lopes Filho, Ferdinand J.; Lima Filho, Jose M.; Santana, Ivan E., E-mail: jose.wilson@recife.ifpe.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco, (IFPE), Recife, PE (Brazil); Andrade, Pedro H.A.; Cabral, Manuela O.M. [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Lima, Vanildo J.M. [Universidade Federal de Pernambuco (DA/UFPE), Recife, PE (Brazil). Departamento de Anatomia; Lima, Fernando R.A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN/CNEN-NE), Recife, PE (Brazil)

    2015-07-01

    For photons and electrons, the effective dose by gender is a weighted sum of the absorbed doses in radiosensitive organs and tissue of the human body. Effective dose is estimated using Exposure Computational Models (ECM) of both genders for the same age group. The FSTA and MSTA ECMs were developed by researchers from DEN/UFPE and consist of voxel phantoms representing adults coupled to EGSnrc Monte Carlo Code, which, in the folder designed for users of EGS, codes were added to simulate some radioactive sources. The reports 60 and 103 of the ICRP provide the factors that weigh the radiosensitivity of organs and tissues (W{sub T}) required to estimate the effective dose. The two lists were placed in the FSTA and MSTA to simulate radiodiagnostic examination in different regions of the body (cranium, abdomen and thorax). The dosimetric data produced allowed an analysis of the effect of the change in the w{sub T} from the report 60 to the 103. The highest mean percent relative error, 64.3%, occurred in the results for the cranium due to the increase of the w{sub T} for most of the organs and tissues in the head and trunk in the updated list. In this case, it can be concluded that the values of the effective dose with the wT of the ICRP 60 were underestimated. Other types of simulators of radioactive sources can be used in investigating this problem and other variables related to the phantom can be considered for that proposes a W{sub T}'s list specific for the Brazilian population or recommend unrestricted use the ICRP data. (author)

  19. Seminar Cum Meeting Report: Codata Task Group for Exchangeable Material Data Representation to Support Research and Education

    Directory of Open Access Journals (Sweden)

    T Ashino

    2008-11-01

    Full Text Available On March 4-5, 2008, the CODATA Task Group for Exchangeable Material Data Representation to Support Research and Education held a two day seminar cum meeting at the National Physical Laboratory (NPL, New Delhi, India, with NPL materials researchers and task group members representing material activities and databases from seven countries: European Union (The Czech Republic, France, and the Netherlands, India, Korea, Japan, and the United States. The NPL seminar included presentations about the researchers' work. The Task Group meeting included presentations about current data related activities of the members. Joint discussions between NPL researchers and CODATA task group members began an exchange of viewpoints among materials data producers, users, and databases developers. The seminar cum meeting included plans to continue and expand Task Group activities at the 2008 CODATA 21st Meeting in Kyiv, Ukraine.

  20. Report of the Task Group 186 on model-based dose calculation methods in brachytherapy beyond the TG-43 formalism: Current status and recommendations for clinical implementation

    Energy Technology Data Exchange (ETDEWEB)

    Beaulieu, Luc [Departement de Radio-Oncologie et Centre de Recherche en Cancerologie de l' Universite Laval, Centre hospitalier universitaire de Quebec, Quebec, Quebec G1R 2J6 (Canada) and Departement de Physique, de Genie Physique et d' Optique, Universite Laval, Quebec, Quebec G1R 2J6 (Canada); Carlsson Tedgren, Asa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linkoeping University, SE-581 85 Linkoeping (Sweden) and Swedish Radiation Safety Authority, SE-171 16 Stockholm (Sweden); Carrier, Jean-Francois [Departement de radio-oncologie, CRCHUM, Centre hospitalier de l' Universite de Montreal, Montreal, Quebec H2L 4M1 (Canada) and Departement de physique, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); and others

    2012-10-15

    The charge of Task Group 186 (TG-186) is to provide guidance for early adopters of model-based dose calculation algorithms (MBDCAs) for brachytherapy (BT) dose calculations to ensure practice uniformity. Contrary to external beam radiotherapy, heterogeneity correction algorithms have only recently been made available to the BT community. Yet, BT dose calculation accuracy is highly dependent on scatter conditions and photoelectric effect cross-sections relative to water. In specific situations, differences between the current water-based BT dose calculation formalism (TG-43) and MBDCAs can lead to differences in calculated doses exceeding a factor of 10. MBDCAs raise three major issues that are not addressed by current guidance documents: (1) MBDCA calculated doses are sensitive to the dose specification medium, resulting in energy-dependent differences between dose calculated to water in a homogeneous water geometry (TG-43), dose calculated to the local medium in the heterogeneous medium, and the intermediate scenario of dose calculated to a small volume of water in the heterogeneous medium. (2) MBDCA doses are sensitive to voxel-by-voxel interaction cross sections. Neither conventional single-energy CT nor ICRU/ICRP tissue composition compilations provide useful guidance for the task of assigning interaction cross sections to each voxel. (3) Since each patient-source-applicator combination is unique, having reference data for each possible combination to benchmark MBDCAs is an impractical strategy. Hence, a new commissioning process is required. TG-186 addresses in detail the above issues through the literature review and provides explicit recommendations based on the current state of knowledge. TG-43-based dose prescription and dose calculation remain in effect, with MBDCA dose reporting performed in parallel when available. In using MBDCAs, it is recommended that the radiation transport should be performed in the heterogeneous medium and, at minimum, the dose to

  1. NASA Engineering Safety Center NASA Aerospace Flight Battery Systems Working Group 2007 Proactive Task Status

    Science.gov (United States)

    Manzo, Michelle A.

    2007-01-01

    In 2007, the NASA Engineering Safety Center (NESC) chartered the NASA Aerospace Flight Battery Systems Working Group to bring forth and address critical battery-related performance/manufacturing issues for NASA and the aerospace community. A suite of tasks identifying and addressing issues related to Ni-H2 and Li-ion battery chemistries was submitted and selected for implementation. The current NESC funded are: (1) Wet Life of Ni-H2 Batteries (2) Binding Procurement (3) NASA Lithium-Ion Battery Guidelines (3a) Li-Ion Performance Assessment (3b) Li-Ion Guidelines Document (3b-i) Assessment of Applicability of Pouch Cells for Aerospace Missions (3b-ii) High Voltage Risk Assessment (3b-iii) Safe Charge Rates for Li-Ion Cells (4) Availability of Source Material for Li-Ion Cells (5) NASA Aerospace Battery Workshop This presentation provides a brief overview of the tasks in the 2007 plan and serves as an introduction to more detailed discussions on each of the specific tasks.

  2. The impacts of hypnotic susceptibility on chaotic dynamics of EEG signals during standard tasks of Waterloo-Stanford Group Scale.

    Science.gov (United States)

    Yargholi, Elahe'; Nasrabadi, Ali Motie

    2013-05-01

    Chaotic features of hypnotic EEG (electroencephalograph), recorded during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility (WSGS), were used to investigate the underlying dynamic of tasks and analyse the effect of hypnotic depth and concentration on EEG signals. Results demonstrate: (1) More efficiency of Higuchi dimension in comparison with Correlation dimension to distinguish subjects from different hypnotizable groups, (2) Channels with significantly different chaotic features among people from various hypnotizability levels in tasks, (3) High level of consistency among discriminating channels of tasks with function of brain's lobes, (4) Most affectability of medium hypnotizable subjects and (5) Rise in fractal dimensions due to increase in hypnosis depth.

  3. Waste Area Grouping 2 Remedial Investigation Phase 1 Seep Task data report: Contaminant source area assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, D.S.

    1996-03-01

    This report presents the findings of the Waste Area Grouping (WAG) 2, Phase 1 Remedial Investigation (RI) Seep Task efforts during 1993 and 1994 at Oak Ridge National Laboratory (ORNL). The results presented here follow results form the first year of sampling, 1992, which are contained in the Phase 1 RI report for WAG 2 (DOE 1995a). The WAG 2 Seep Task efforts focused on contaminants in seeps, tributaries, and main streams within the White Oak Creek (WOC) watershed. This report is designed primarily as a reference for contaminants and a resource for guiding remedial decisions. Additional in-depth assessments of the Seep Task data may provide clearer understandings of contaminant transport from the different source areas in the WOC watershed. WAG 2 consists of WOC and its tributaries downstream of the ORNL main plant area, White Oak Lake, the White Oak Creek Embayment of the Clinch River, and the associated flood plains and subsurface environment. The WOC watershed encompasses ORNL and associated WAGs. WAG 2 acts as an integrator for contaminant releases from the contaminated sites at ORNL and as the conduit transporting contaminants to the Clinch River. The main objectives of the Seep Task were to identify and characterize seeps, tributaries and source areas that are responsible for the contaminant releases to the main streams in WAG 2 and to quantify their input to the total contaminant release from the watershed at White Oak Dam (WOD). Efforts focused on {sup 90}Sr, {sup 3}H, and {sup 137}Cs because these contaminants pose the greatest potential human health risk from water ingestion at WOD. Bimonthly sampling was conducted throughout the WOC watershed beginning in March 1993 and ending in August 1994. Samples were also collected for metals, anions, alkalinity, organics, and other radionuclides.

  4. Mindfulness Training Improves Attentional Task Performance in Incarcerated Youth: A Group Randomized Controlled Intervention Trial

    Directory of Open Access Journals (Sweden)

    Noelle R Leonard

    2013-11-01

    Full Text Available We investigated the impact of cognitive behavioral therapy and mindfulness training (CBT/MT on attentional task performance in incarcerated adolescents. Attention is a cognitive system necessary for managing cognitive demands and regulating emotions. Yet persistent and intensive demands, such as those experienced during high-stress intervals like incarceration and the events leading to incarceration, may deplete attention resulting in cognitive failures, emotional disturbances, and impulsive behavior. We hypothesized that CBT/MT may mitigate these deleterious effects of high stress and protect against degradation in attention over the high-stress interval of incarceration. Using a group randomized controlled trial design, we randomly assigned dormitories of incarcerated youth, ages 16 to 18, to a CBT/MT intervention (youth n = 147 or an active control intervention (youth n = 117. Both arms received approximately 750 minutes of intervention in a small-group setting over a 3-5 week period. Youth in the CBT/MT arm also logged the amount of out-of-session time spent practicing MT exercises. The Attention Network Test was used to index attentional task performance at baseline and 4 months post-baseline. Overall, task performance degraded over time in all participants. The magnitude of performance degradation was significantly less in the CBT/MT vs. control arm. Further, within the CBT/MT arm, performance degraded over time in those with no outside-of-class practice time, but remained stable over time in those who practiced mindfulness exercises outside of the session meetings. Thus, these findings suggest that sufficient CBT/MT practice may protect against functional attentional impairments associated with high-stress intervals. Keywords: adolescent development, incarcerated adolescents, detained adolescents, stress, attention, mindfulness meditation.

  5. TU-EF-210-04: AAPM Task Groups in Interventional Ultrasound Imaging and Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Farahani, K. [National Cancer Institute (United States)

    2015-06-15

    The use of therapeutic ultrasound to provide targeted therapy is an active research area that has a broad application scope. The invited talks in this session will address currently implemented strategies and protocols for both hyperthermia and ablation applications using therapeutic ultrasound. The role of both ultrasound and MRI in the monitoring and assessment of these therapies will be explored in both pre-clinical and clinical applications. Katherine Ferrara: High Intensity Focused Ultrasound, Drug Delivery, and Immunotherapy Rajiv Chopra: Translating Localized Doxorubicin Delivery to Pediatric Oncology using MRI-guided HIFU Elisa Konofagou: Real-time Ablation Monitoring and Lesion Quantification using Harmonic Motion Imaging Keyvan Farahani: AAPM Task Groups in Interventional Ultrasound Imaging and Therapy Learning Objectives: Understand the role of ultrasound in localized drug delivery and the effects of immunotherapy when used in conjunction with ultrasound therapy. Understand potential targeted drug delivery clinical applications including pediatric oncology. Understand the technical requirements for performing targeted drug delivery. Understand how radiation-force approaches can be used to both monitor and assess high intensity focused ultrasound ablation therapy. Understand the role of AAPM task groups in ultrasound imaging and therapies. Chopra: Funding from Cancer Prevention and Research Initiative of Texas (CPRIT), Award R1308 Evelyn and M.R. Hudson Foundation; Research Support from Research Contract with Philips Healthcare; COI are Co-founder of FUS Instruments Inc Ferrara: Supported by NIH, UCDavis and California (CIRM and BHCE) Farahani: In-kind research support from Philips Healthcare.

  6. Promoting Oral Interaction in Large Groups through Task-Based Learning

    Directory of Open Access Journals (Sweden)

    Yolima Forero Rocha

    2005-10-01

    Full Text Available This research project attempts to show the way a group of five teachers used task-based learning with a group of 50 seventh graders to improve oral interaction. The students belonged to Isabel II School. They took an active part in the implementation of tasks and were asked to answer two questionnaires. Some English classes were observed and recorded; finally, an evaluation was taken by students to test their improvement.Este proyecto de investigación trata de mostrar la forma como un grupo de cinco profesoras usaron el método de aprendizaje basado en tareas con un grupo de 50 estudiantes del grado séptimo, con el fin de mejorar la interacción oral. Los estudiantes pertenecían al Colegio Isabel II y fueron parte activa en la implementación de las tareas. Respondieron dos cuestionarios, se les observó y se grabaron en video algunas clases; finalmente, se hizo una evaluación para poner a prueba el avance de los estudiantes.

  7. Friendship group identification, multidimensional self-concept, and experience of developmental tasks in adolescence.

    Science.gov (United States)

    Tarrant, Mark; MacKenzie, Liam; Hewitt, Lisa A

    2006-08-01

    This study applied a social identity perspective to the study of adolescent self-concept and social development. British adolescents aged 14-15 years (N=114) completed a questionnaire which asked them to: (i) rate their degree of identification with a school-based friendship group; (ii) complete a measure of multi-dimensional self-concept; and (iii) report their experiences of a variety of personal, relational and socio-institutional (e.g., achieving economic independence) developmental tasks. Compared to low identifiers, participants who were highly identified with a friendship group reported highest levels of self-esteem; and these differences were most marked in non-academic domains of self. High identifiers also displayed higher levels of general self-esteem and reported more positive experiences of personal and relational developmental tasks. The discussion focuses on the potential benefits to understanding of social developmental processes that can be derived from a consideration of adolescents' subjective appraisals of their peer relations.

  8. Using Group Learning Activities in the Task-based Composition Class

    Institute of Scientific and Technical Information of China (English)

    Anita M. Copeland Kess; Joseph F. Kess

    2001-01-01

    @@ Research in general education has pointed to the effectiveness of task-based language teaching (TBLT). Task-based syllabi focus on tasks which require students to use the language for communication, but more specifically, on tasks which will be used outside of the classroom.

  9. ICRP 2015. International symposium on the radiation protection system. Report and reflection on a significant symposium; ICRP 2015. 3. Internationales Symposium zum System des Strahlenschutzes. Bericht und Reflexion ueber ein bedeutsames Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Bernd

    2016-08-01

    The ICRP international symposium on the radiation protection system provides always extensive information on new developments in radiation protection. The ICRP 2105 discussed the following issues: radiation effects of low dose irradiation, dose coefficients for internal and external exposures, radiation protection in nuclear medicine, application of ICRP recommendations, environmental protection, studies on existing exposure situations, medical radiation protection today, science behind radiation doses, new developments in radiation effects, and ethics in radiation protection.

  10. Biokinetic of plutonium in human beings. Analysis and modification of ICRP 67 model; Biocinetica del plutonio nell'organismo umano. Analisi e modifica del modello ICRP 67

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, A.; Castellani, C.M. [ENEA, Divisione Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche Ezio Clementel, Bologna (Italy)

    2001-07-01

    A preliminary research of the available data and empirical functions for the plutonium excretion after injection was carried out. The ICRP model presented in the Publication no. 67 was then analyzed comparing its predictions for the activity in urine and, at a lesser extent, in feces and blood, with the collected data and empirical curves. The model was modified and an optimized age-related compartmental model was developed. A new skeletal model recently developed was also introduced and age depending bone remodelling rates were assumed on the basis of the ICRP Publication 70. This model provides a better agreement with measured urinary excretion data than the current ICRP 67 model, avoiding unphysiological assumptions such as the transfer of activity from soft tissue to urinary bladder, that were part of the ICRP model. The new optimized model predictions of the activity in faeces and in blood after an injection are also closer to the available data than the ICRP 67 estimations. A good agreement with the partitioning factor of plutonium between skeleton and liver obtained from different autopsy studies was also observed. [Italian] E' stata effettuata preliminarmente una ricerca bibliografica dei dati e delle funzioni di escrezione del plutonio attualmente disponibili in letteratura. Sulla base dei risultati di tale ricerca e' stato verificato il modello proposto dall'ICRP nella Pubblicazione n. 67. Tale modello e' stato quindi modificato al fine non solo di avere una piu' realistica descrizione dei valori predetti per l'escrezione urinaria, ma anche di modellare la cinetica del plutonio evitando quelle assunzioni introdotte appositamente nel modello dell'ICRP per correggere le previsini del modello ma che mancano di una chiara spiegazione di carattere fisiologico. Esso fornisce valutazioni piu' realistiche anche per l'attivita' nelle feci e nel sangue. Il modello sviluppato comprende un modello scheletrico

  11. The birth of NASA the work of the Space Task Group, America's first true space pioneers

    CERN Document Server

    von Ehrenfried, Dutch

    2016-01-01

    This is the story of the work of the original NASA space pioneers; men and women who were suddenly organized in 1958 from the then National Advisory Committee on Aeronautics (NACA) into the Space Task Group. A relatively small group, they developed the initial mission concept plans and procedures for the U. S. space program. Then they boldly built hardware and facilities to accomplish those missions. The group existed only three years before they were transferred to the Manned Spacecraft Center in Houston, Texas, in 1962, but their organization left a large mark on what would follow. Von Ehrenfried's personal experience with the STG at Langley uniquely positions him to describe the way the group was structured and how it reacted to the new demands of a post-Sputnik era. He artfully analyzes how the growing space program was managed and what techniques enabled it to develop so quickly from an operations perspective. The result is a fascinating window into history, amply backed up by first person documentation ...

  12. When sad groups expect to meet again : Interactive affective sharing and future interaction expectation as determinants of work groups' analytical and creative task performance

    NARCIS (Netherlands)

    Klep, Annefloor H. M.; Wisse, Barbara; van der Flier, Henk

    2013-01-01

    The present study examines the moderating role of future interaction expectation in the relationship between affective sharing and work groups' task performance. We argue that group affect, a group defining characteristic, becomes more salient to its members when it is interactively shared, and that

  13. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151.

    Science.gov (United States)

    Jones, A Kyle; Heintz, Philip; Geiser, William; Goldman, Lee; Jerjian, Khachig; Martin, Melissa; Peck, Donald; Pfeiffer, Douglas; Ranger, Nicole; Yorkston, John

    2015-11-01

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  14. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org; Geiser, William [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Heintz, Philip [Department of Radiology, University of New Mexico, Albuquerque, New Mexico 87104 (United States); Goldman, Lee [Hartford Hospital, Hartford, Connecticut 06102 (United States); Jerjian, Khachig [Hoag Memorial Hospital, Newport Beach, California 92658 (United States); Martin, Melissa [Therapy Physics, Inc., Gardena, California 90248 (United States); Peck, Donald [Henry Ford Health System, Detroit, Michigan 48202 (United States); Pfeiffer, Douglas [Boulder Community Foothills Hospital, Boulder, Colorado 80303 (United States); Ranger, Nicole [Landauer, Inc., Glenwood, Illinois 60425 (United States); Yorkston, John [Carestream Health, Inc., Rochester, New York 14615 (United States)

    2015-11-15

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  15. An Agent-Based Simulation for Investigating the Impact of Stereotypes on Task-Oriented Group Formation

    Science.gov (United States)

    Maghami, Mahsa; Sukthankar, Gita

    In this paper, we introduce an agent-based simulation for investigating the impact of social factors on the formation and evolution of task-oriented groups. Task-oriented groups are created explicitly to perform a task, and all members derive benefits from task completion. However, even in cases when all group members act in a way that is locally optimal for task completion, social forces that have mild effects on choice of associates can have a measurable impact on task completion performance. In this paper, we show how our simulation can be used to model the impact of stereotypes on group formation. In our simulation, stereotypes are based on observable features, learned from prior experience, and only affect an agent's link formation preferences. Even without assuming stereotypes affect the agents' willingness or ability to complete tasks, the long-term modifications that stereotypes have on the agents' social network impair the agents' ability to form groups with sufficient diversity of skills, as compared to agents who form links randomly. An interesting finding is that this effect holds even in cases where stereotype preference and skill existence are completely uncorrelated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Matuszak, M; Feng, M [University of Michigan, Ann Arbor, MI (United States); Moran, J [Univ Michigan Medical Center, Ann Arbor, MI (United States); Xiao, Y [Thomas Jefferson University, Philadelphia, PA (United States); Mayo, C; Miller, R [Mayo Clinic, Rochester, MN (United States); Bosch, W [Washington Univ, Saint Louis, MO (United States); Popple, R [Univ Alabama Birmingham, Birmingham, AL (United States); Marks, L [UNC School of Medicine, Chapel Hill, NC (United States); Wu, Q [Duke University Medical Center, Durham, NC (United States); Molineu, A; Martel, M [UT MD Anderson Cancer Center, Houston, TX (United States); Yock, T [Massachusetts General Hospital, Boston, MA (United States); McNutt, T [Johns Hopkins University, Severna Park, MD (United States); Brown, N [Baptist Medical Center, Jacksonville, FL (United States); Purdie, T [Princess Margaret Hospital, Toronto, ON (Canada); Yorke, E [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Santanam, L [Washington University School of Medicine, St.louis, MO (United States); Gabriel, P [University of Pennsylvania, Philadelphia, PA (United States); Michalski, J [Washington University, Saint Louis, MO (United States); 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

  17. Conversion of ICRP male reference phantom to polygon-surface phantom

    Science.gov (United States)

    Yeom, Yeon Soo; Han, Min Cheol; Kim, Chan Hyeong; Jeong, Jong Hwi

    2013-10-01

    The International Commission on Radiological Protection (ICRP) reference phantoms, developed based on computed tomography images of human bodies, provide much more realism of human anatomy than the previously used MIRD5 (Medical Internal Radiation Dose) mathematical phantoms. It has been, however, realized that the ICRP reference phantoms have some critical limitations showing a considerable amount of holes for the skin and wall organs mainly due to the nature of voxels of which the phantoms are made, especially due to their low voxel resolutions. To address this problem, we are planning to develop the polygon-surface version of ICRP reference phantoms by directly converting the ICRP reference phantoms (voxel phantoms) to polygon-surface phantoms. The objective of this preliminary study is to see if it is indeed possible to construct the high-quality polygon-surface phantoms based on the ICRP reference phantoms maintaining identical organ morphology and also to identify any potential issues, and technologies to address these issues, in advance. For this purpose, in the present study, the ICRP reference male phantom was roughly converted to a polygon-surface phantom. Then, the constructed phantom was implemented in Geant4, Monte Carlo particle transport code, for dose calculations, and the calculated dose values were compared with those of the original ICRP reference phantom to see how much the calculated dose values are sensitive to the accuracy of the conversion process. The results of the present study show that it is certainly possible to convert the ICRP reference phantoms to surface phantoms with enough accuracy. In spite of using relatively less resources (<2 man-months), we were able to construct the polygon-surface phantom with the organ masses perfectly matching the ICRP reference values. The analysis of the calculated dose values also implies that the dose values are indeed not very sensitive to the detailed morphology of the organ models in the phantom

  18. [Social participation processes, task-oriented participation and learning as antecedents of group cohesion. A longitudinal perspective].

    Science.gov (United States)

    Picazo Lahiguera, Carmen; Zornoza Abad, Ana; Peiró Silla, José M

    2009-05-01

    The aim of this paper is to analyze the effect of changes in social participation and task- and learning-oriented processes on the development of cohesion (social and task-focused) in new groups. Cohesion has been considered one of the most important constructs in small groups, and its influence on team performance and efficacy has been highlighted. However, there are few papers that analyze the processes and the variables that precede the construct and that affect its evolution. Results of the longitudinal study show the importance of changes in participation processes on the development of task cohesion and social cohesion.

  19. Picture Novelty Influences Response Selection and Inhibition: The Role of the In-Group Bias and Task-Difficulty

    Science.gov (United States)

    Zinchenko, Artyom; Mahmud, Waich; Alam, Musrura Mefta; Kabir, Nadia; Al-Amin, Md. Mamun

    2016-01-01

    The human visual system prioritizes processing of novel information, leading to faster detection of novel stimuli. Novelty facilitates conflict resolution through the enhanced early perceptual processing. However, the role of novel information processing during the conflict-related response selection and inhibition remains unclear. Here, we used a face-gender classification version of the Simon task and manipulated task-difficulty and novelty of task-relevant information. The novel quality of stimuli was made task-irrelevant, and an in-group bias was tightly controlled by manipulation of a gender of picture stimuli. We found that the in-group bias modulated the role of novelty in executive control. Novel opposite-sex stimuli facilitated response inhibition only when the task was not demanding. By contrast, novelty enhanced response selection irrespective of the in-group factor when task-difficulty was increased. These findings support the in-group bias mechanism of visual processing, in cases when attentional resources are not limited by a demanding task. The results are further discussed along the lines of the attentional load theory and neural mechanisms of response-inhibition and locomotor activity. In conclusion, our data showed that processing of novel information may enhance executive control through facilitated response selection and inhibition. PMID:27788213

  20. Examining the Impact of Novel Pre-activity Tasks on Macroskills: The Case of Group Discussion on Writing Ability

    Directory of Open Access Journals (Sweden)

    Hooshang Khoshsima

    2016-02-01

    Full Text Available The main concern of most researchers in the field of second and foreign language teaching is lessening the problems and eliminating the hinders on the way of learning a language. Writing is considered as one of the most challenging and complicated tasks for learners to perform particularly when they have to write in a second or foreign language. Numerous studies were done on the importance of the pre-writing stage and activities which are directly and indirectly related to the theme of the writing. Accordingly, the main aim of this study was to examine the effects of group discussion as a pre- activity task on writing ability. To this aim, 27 Iranian EFL learners, who were at the same level –intermediate- studying at Shokuh and Safir Institutes, Birjand, Iran were chosen randomly. Two groups- one control and one experimental group- were studied. In control group the conventional method was used in teaching writing, while in experimental group, group discussion pre-activity task was administered. After 16 sessions, the obtained data of the pretests and posttests was analyzed by SPSS software. According to the results, researcher strongly concluded that group discussion has no significant effect on writing ability of Iranian intermediate learners. This study can help teachers and syllabus designers in choosing and applying an effective pre-activity task. Keywords: writing ability, pre-activity task, group discussion, EFL learners

  1. How Knowledge Worker Teams Deal Effectively with Task Uncertainty: The Impact of Transformational Leadership and Group Development.

    Science.gov (United States)

    Leuteritz, Jan-Paul; Navarro, José; Berger, Rita

    2017-01-01

    The purpose of this paper is to clarify how leadership is able to improve team effectiveness, by means of its influence on group processes (i.e., increasing group development) and on the group task (i.e., decreasing task uncertainty). Four hundred and eight members of 107 teams in a German research and development (R&D) organization completed a web-based survey; they provided measures of transformational leadership, group development, 2 aspects of task uncertainty, task interdependence, and team effectiveness. In 54 of these teams, the leaders answered a web-based survey on team effectiveness. We tested the model with the data from team members, using structural equations modeling. Group development and a task uncertainty measurement that refers to unstable demands from outside the team partially mediate the effect of transformational leadership on team effectiveness in R&D organizations (p transformational leaders reduce unclarity of goals (p transformational leadership and team processes on team effectiveness considering the task characteristics uncertainty and interdependence.

  2. How Knowledge Worker Teams Deal Effectively with Task Uncertainty: The Impact of Transformational Leadership and Group Development

    Directory of Open Access Journals (Sweden)

    Jan-Paul Leuteritz

    2017-08-01

    Full Text Available The purpose of this paper is to clarify how leadership is able to improve team effectiveness, by means of its influence on group processes (i.e., increasing group development and on the group task (i.e., decreasing task uncertainty. Four hundred and eight members of 107 teams in a German research and development (R&D organization completed a web-based survey; they provided measures of transformational leadership, group development, 2 aspects of task uncertainty, task interdependence, and team effectiveness. In 54 of these teams, the leaders answered a web-based survey on team effectiveness. We tested the model with the data from team members, using structural equations modeling. Group development and a task uncertainty measurement that refers to unstable demands from outside the team partially mediate the effect of transformational leadership on team effectiveness in R&D organizations (p < 0.05. Although transformational leaders reduce unclarity of goals (p < 0.05, this seems not to contribute to team effectiveness. The data provided by the leaders was used to assess common source bias, which did not affect the interpretability of the results. Limitations include cross-sectional data and a lower than expected variance of task uncertainty across different job types. This paper contributes to understanding how knowledge worker teams deal effectively with task uncertainty and confirms the importance of group development in this context. This is the first study to examine the effects of transformational leadership and team processes on team effectiveness considering the task characteristics uncertainty and interdependence.

  3. Recommendations for clinical electron beam dosimetry: supplement to the recommendations of Task Group 25.

    Science.gov (United States)

    Gerbi, Bruce J; Antolak, John A; Deibel, F Christopher; Followill, David S; Herman, Michael G; Higgins, Patrick D; Huq, M Saiful; Mihailidis, Dimitris N; Yorke, Ellen D; Hogstrom, Kenneth R; Khan, Faiz M

    2009-07-01

    The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of.Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at 60Co energy, N60Co(D,w), together with the theoretical beam quality conversion coefficient k(Q) for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high-energy electron beams. The use of

  4. Comparison between Brazilian radiation protection norm and ICRP recommendations published in 2007

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S.; Py Junior, Delcy de A., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Servico de Radioprotecao. Grupo Multidisciplinar de Radioprotecao; Pereira, Juliana R. de S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil). Campus Pocos de Caldas; Kelecom, Alphonse, E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (GETA/LARARA-PLS/UFF), Niteroi, RJ (Brazil). Laboratorio de Radiobiologia e Radiometria Pedro Lopes dos Santos. Grupo de Estudos em Temas Ambientais; Mortagua, Valter, E-mail: Valter@inb.gov.br [Usina de lnterlagos (USIN), Sao Paulo, SP (Brazil). Coordenacao

    2013-07-01

    In the year 2007, ICRP published a set of recommendations (The 2007 Recommendations of the International Commission on Radiological Protection, Publication 103), which changed some important concepts. This work aims to compare the Brazilian radiation protection basic norm with the new ICRP recommendations, by checking the existing differences. The main difference between ICRP publication 60 and ICRP publication 103 is the changing of the concept of protection based on process, by using the concepts of practice and intervention, to the protection based in the exposition situation, by using the concepts of planned exposure, emergency and existing situation. Other important difference lies in the values of the radiation and tissue weighting factors, in the quantities equivalent and effective dose, and updating the radiation detriment based on the latest available scientific information of the biology and physics of radiation exposure. At last, the demonstration of the environment radiation protection must be clear, and this concept is not found in Brazilian nuclear legislation. Also some similarities were found. The fundamental principles of the Brazilian norms are the same as that of ICRP 103, which are the justification principle, the optimization principle and the application of dose limits. The individual effective dose limit of Brazilian norm is the same of the ICRP 103, established as 20 mSv per year. In order to adequate the Brazilian norm it is necessary to change its concept of protection and the values of radiation and tissue weighting, and updating the radiation detriment, besides making clear the concept of protection of the environment. It is important to notice that although the Brazilian norm is not in complete agreement with all international recommendations, it must be completely followed as the norm which is in use in the country. (author)

  5. When sad groups expect to meet again: interactive affective sharing and future interaction expectation as determinants of work groups' analytical and creative task performance.

    Science.gov (United States)

    Klep, Annefloor H M; Wisse, Barbara; van der Flier, Henk

    2013-12-01

    The present study examines the moderating role of future interaction expectation in the relationship between affective sharing and work groups' task performance. We argue that group affect, a group defining characteristic, becomes more salient to its members when it is interactively shared, and that the anticipation of future interaction may strengthen the effects of group defining characteristics on subsequent group member behaviour. As a consequence, interactive sharing (vs. non-interactive sharing) of negative affect is more likely to influence work group outcomes when group members expect to meet again. Results from a laboratory experiment with 66 three-person work groups indeed show that interactively shared (vs. non-interactively shared) negative affect facilitated work groups' analytical task performance, whereas it inhibited performance on a creative fluency task when groups have expectations of future interaction and not when they do not have such expectations. The discussion focuses on how these results add to theory on group affect and contribute to insights in the effects of future interaction expectation.

  6. Towards mainstreaming of biodiversity data publishing: recommendations of the GBIF Data Publishing Framework Task Group

    Directory of Open Access Journals (Sweden)

    Moritz Tom

    2011-12-01

    'data publishing framework' that can address sociocultural, technical-infrastructural, policy, political and legal constraints, as well as addressing issues of sustainability and financial support. To address these aspects of a data publishing framework - a systematic, standard approach to the formal definition and public disclosure of data - in the context of biodiversity data, the Global Biodiversity Information Facility (GBIF, the single inter-governmental body most clearly mandated to undertake such an effort convened a Data Publishing Framework Task Group. We conceive this data publishing framework as an environment conducive to ensure free and open access to world's biodiversity data. Here, we present the recommendations of that Task Group, which are intended to encourage free and open access to the worlds' biodiversity data.

  7. Towards mainstreaming of biodiversity data publishing: recommendations of the GBIF Data Publishing Framework Task Group

    Science.gov (United States)

    2011-01-01

    can address sociocultural, technical-infrastructural, policy, political and legal constraints, as well as addressing issues of sustainability and financial support. To address these aspects of a data publishing framework - a systematic, standard approach to the formal definition and public disclosure of data - in the context of biodiversity data, the Global Biodiversity Information Facility (GBIF, the single inter-governmental body most clearly mandated to undertake such an effort) convened a Data Publishing Framework Task Group. We conceive this data publishing framework as an environment conducive to ensure free and open access to world's biodiversity data. Here, we present the recommendations of that Task Group, which are intended to encourage free and open access to the worlds' biodiversity data. PMID:22373150

  8. Bay of Bengal Monsoon Experiment (BOBMEX) — A component of the Indian Climate Research Programme (ICRP)

    Indian Academy of Sciences (India)

    D R Sikka; P Sanjeeva Rao

    2000-06-01

    The Indian Climate Research Programme (ICRP) focuses on the study of climate variability and its impact on agriculture. To address the role of the Bay of Bengal in monsoon variability, a process study was organised during July-August 1999, deploying research ships, buoys, INSAT, coastal radar and conventional observational systems to collect information about the coupled ocean-atmosphere system over the warm waters of the Bay of Bengal. The paper gives the background of the ICRP and the organisation and implementation of the Bay of Bengal Monsoon Experiment (BOBMEX) in its field phase.

  9. Using a Random Dependent Group Contingency to Increase On-Task Behaviors of High School Students with High Incidence Disabilities

    Science.gov (United States)

    Williamson, Brenda D.; Campbell-Whatley, Gloria D.; Lo, Ya-yu

    2009-01-01

    Group contingencies have the advantages of encouraging individual students to collectively feel responsible for appropriate and inappropriate classroom behaviors and have shown effectiveness in improving students' behavior. The purpose of this study was to investigate the effects of a random dependent group contingency on the on-task behaviors of…

  10. Analysis of Heart Rate Variability in Chinese PLA Navy Global Visiting Task Group

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-sheng; CHU Li-yun; GONG Ting

    2014-01-01

    Objective: To analyze the heart rate variability in Chinese PLA navy global visiting task group. Methods:We analyzed the heart rate variability in Holter in 77 men and 4 women for 5-15 days before voyage, and 65-75 and 115-125 days after voyage, and 29 men and 3 women for 5-15 days after having finished voyage. Results:NN50 and VLF were lower in 77 men and 4 women for 65-75 days after voyage than that was 5-15 days before voyage (P<0.01). SDANN was lower in 77 men and 4 women for 115-125 days after voyage than that was 65-75 days after voyage (P<0.01). SDNN, SDANN, SDNN index, RMSSD, NN50, PNN50,Triangular index, VLF, HLF, VAI and VLI were lower in 77 men and 4 women for 65-75 days after voyage than that was 5-15 days before voyage (P<0.01).Conclusion: These findings suggest that voyage may reduce heart rate variability for a long time.

  11. Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

    Science.gov (United States)

    Serago, Christopher F; Adnani, Nabil; Bank, Morris I; BenComo, Jose A; Duan, Jun; Fairobent, Lynne; Freedman, D Jay; Halvorsen, Per H; Hendee, William R; Herman, Michael G; Morse, Richard K; Mower, Herbert W; Pfeiffer, Douglas E; Root, William J; Sherouse, George W; Vossler, Matthew K; Wallace, Robert E; Walters, Barbara

    2009-01-01

    A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24-A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4-B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5-C); Guidelines for Ethical Practice for Medical Physicists (PP 8-D); and Ethics Complaint Procedure (PP 21-A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008.

  12. Radiation dosimetry in digital breast tomosynthesis: Report of AAPM Tomosynthesis Subcommittee Task Group 223

    Energy Technology Data Exchange (ETDEWEB)

    Sechopoulos, Ioannis, E-mail: isechop@emory.edu [Departments of Radiology and Imaging Sciences, Hematology and Medical Oncology and Winship Cancer Institute, Emory University, 1701 Uppergate Drive Northeast, Suite 5018, Atlanta, Georgia 30322 (United States); Sabol, John M. [GE Healthcare, Global Diagnostic X-Ray, Mailstop W-701, 3000 North Grandview Boulevard, Waukesha, Wisconsin 53188 (United States); Berglund, Johan [Research and Development, Philips Women' s Healthcare, Solna (Sweden); Bolch, Wesley E. [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Brateman, Libby [University of Florida, Gainesville, Florida 32611 (United States); Christodoulou, Emmanuel; Goodsitt, Mitchell [Department of Radiology, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109 (United States); Flynn, Michael [Department of Radiology, Henry Ford Health System, Radiology Research 2F, 1 Ford Place, Detroit, Michigan 48202 (United States); Geiser, William [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States); Kyle Jones, A. [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Lo, Joseph Y.; Paul Segars, W. [Department of Radiology, Medical Physics Graduate Program, and Department of Biomedical Engineering, Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Maidment, Andrew D. A. [Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4206 (United States); Nishino, Kazuyoshi [R and D X-ray Products Group, Shimadzu Corporation, Tokyo (Japan); Nosratieh, Anita [Biomedical Engineering Graduate Group, Department of Radiology, University of California, Davis, California 95817 (United States); and others

    2014-09-15

    The radiation dose involved in any medical imaging modality that uses ionizing radiation needs to be well understood by the medical physics and clinical community. This is especially true of screening modalities. Digital breast tomosynthesis (DBT) has recently been introduced into the clinic and is being used for screening for breast cancer in the general population. Therefore, it is important that the medical physics community have the required information to be able to understand, estimate, and communicate the radiation dose levels involved in breast tomosynthesis imaging. For this purpose, the American Association of Physicists in Medicine Task Group 223 on Dosimetry in Tomosynthesis Imaging has prepared this report that discusses dosimetry in breast imaging in general, and describes a methodology and provides the data necessary to estimate mean breast glandular dose from a tomosynthesis acquisition. In an effort to maximize familiarity with the procedures and data provided in this Report, the methodology to perform the dose estimation in DBT is based as much as possible on that used in mammography dose estimation.

  13. Radiation dosimetry in digital breast tomosynthesis: report of AAPM Tomosynthesis Subcommittee Task Group 223.

    Science.gov (United States)

    Sechopoulos, Ioannis; Sabol, John M; Berglund, Johan; Bolch, Wesley E; Brateman, Libby; Christodoulou, Emmanuel; Flynn, Michael; Geiser, William; Goodsitt, Mitchell; Jones, A Kyle; Lo, Joseph Y; Maidment, Andrew D A; Nishino, Kazuyoshi; Nosratieh, Anita; Ren, Baorui; Segars, W Paul; Von Tiedemann, Miriam

    2014-09-01

    The radiation dose involved in any medical imaging modality that uses ionizing radiation needs to be well understood by the medical physics and clinical community. This is especially true of screening modalities. Digital breast tomosynthesis (DBT) has recently been introduced into the clinic and is being used for screening for breast cancer in the general population. Therefore, it is important that the medical physics community have the required information to be able to understand, estimate, and communicate the radiation dose levels involved in breast tomosynthesis imaging. For this purpose, the American Association of Physicists in Medicine Task Group 223 on Dosimetry in Tomosynthesis Imaging has prepared this report that discusses dosimetry in breast imaging in general, and describes a methodology and provides the data necessary to estimate mean breast glandular dose from a tomosynthesis acquisition. In an effort to maximize familiarity with the procedures and data provided in this Report, the methodology to perform the dose estimation in DBT is based as much as possible on that used in mammography dose estimation.

  14. Development of internal dosimetry protocols using the code MCNPx and voxelized phantoms of Reference of ICRP 110; Desenvolvimento de protocolos de dosimetria interna empregando o codigo MCNPx e fantomas voxelizados de referencia da ICRP 110

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, B.M.; Fonseca, T.C.F., E-mail: bmm@cdtn.br [Centro de esenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Trindade, B.M.; Campos, T.P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-04-01

    The objective of this work was to perform internal dosimetry calculations for {sup 18}F-FDG employing the MCNPx code and ICRP 110 voxelized reference phantoms (RCP{sub A}F and RCP{sub A}M). The methodologies developed and validated here represent protocols of internal dosimetry holding a better anthropomorphic and anthropometric representation of the human model in which heterogeneous distributions of the emissions can be adopted, useful in the study of new radiopharmaceuticals and internal contamination cases. The reference phantoms were implemented to run on MCNPx. Biodistribution data of {sup 18}F-FDG radiopharmaceutical provided in ICRP 128 were used in the simulations. The organs average absorbed doses and the effective doses were calculated for each model. The values obtained were compared with two reference works available in the literature for validation purposes. The means of the difference of our values and Zankl et al., 2012 reference values were -0.3% for RCP{sub A}M and -0.4% for RCP{sub A}F. Considering Hadid et al., 2013 reference values, the means of the deviation were -2.9% and -2.2% for RCP{sub A}M and RCP{sub A}F respectively. No statistically significant differences were observed (p <0.01) between the reference values and the values calculated by the internal dosimetry protocols developed by our group. Considering the {sup 18}F-FDG validation study performed in this work, the internal dosimetry protocols developed by our group have produced suitable dosimetry data. (author)

  15. Collaborative Writing Tasks in the L2 Classroom: Comparing Group, Pair, and Individual Work

    Science.gov (United States)

    Dobao, Ana Fernandez

    2012-01-01

    This study investigates the benefits of collaborative writing tasks. Previous research from the perspective of the sociocultural theory of mind suggests that writing tasks completed in pairs offer learners an opportunity to collaborate in the solution of their language-related problems, co-construct new language knowledge, and produce…

  16. Role of Gestalt grouping in selective attention: Evidence from the Stroop task

    NARCIS (Netherlands)

    Lamers, M.J.M.; Roelofs, A.P.A.

    2007-01-01

    Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover,

  17. Feel Like You Belong: On the Bidirectional Link Between Emotional Fit and Group Identification in Task Groups

    Directory of Open Access Journals (Sweden)

    Ellen eDelvaux

    2015-08-01

    Full Text Available Three studies investigated the association between members’ group identification and the emotional fit with their group. In the first study, a cross-sectional study in a large organization, we replicated earlier research by showing that group identification and emotional fit are positively associated, using a broader range of emotions and using profile correlations to measure group members’ emotional fit. In addition, in two longitudinal studies, where groups of students were followed at several time points during their collaboration on a project, we tested the directionality of the relationship between group identification and emotional fit. The results showed a bidirectional, positive link between group identification and emotional fit, such that group identification and emotional fit either mutually reinforce or mutually dampen each other over time. We discuss how these findings increase insights in group functioning and how they may be used to change group processes for better or worse.

  18. Applicability of dose conversion coefficients of ICRP 74 to Asian adult males: Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choonsik [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611-8300 (United States)]. E-mail: choonsiklee@gmail.com; Lee, Choonik [Anderson Cancer Center Orlando, Orlando, FL 32806 (United States); Lee, Jai-Ki [Department of Nulcear Engineering, Hanyang University, Haengdang, Sungdong 133-791 (Korea, Republic of)

    2007-05-15

    International Commission on Radiological Protection (ICRP) reported comprehensive dose conversion coefficients for adult population, which is exposed to external photon sources in the Publication 74. However, those quantities were calculated from so-called stylized (or mathematical) phantoms composed of simplified mathematical surface equations so that the discrepancy between the phantoms and real human anatomy has been investigated by several authors using Caucasian-based voxel phantoms. To address anatomical and racial limitations of the stylized phantoms, several Asian-based voxel phantoms have been developed by Korean and Japanese investigators, independently. In the current study, photon dose conversion coefficients of ICRP 74 were compared with those from a total of five Asian-based male voxel phantoms, whose body dimensions were almost identical. Those of representative radio-sensitive organs (testes, red bone marrow, colon, lungs, and stomach), and effective dose conversion coefficients were obtained for comparison. Even though organ doses for testes, colon and lungs, and effective doses from ICRP 74 agreed well with those from Asian voxel phantoms within 10%, absorbed doses for red bone marrow and stomach showed significant discrepancies up to 30% which was mainly attributed to difference of phantom description between stylized and voxel phantoms. This study showed that the ICRP 74 dosimetry data, which have been reported to be unrealistic compared to those from Caucasian-based voxel phantoms, are also not appropriate for Asian population.

  19. Activities of the task group 8 on thin film PV module reliability (Conference Presentation)

    Science.gov (United States)

    Dhere, Neelkanth G.

    2016-09-01

    Photovoltaic (PV) modules and systems are being used increasingly to provide renewable energy to schools, residences, small businesses and utilities. At this time, the home owners and small businesses have considerable difficulty in detecting module and/or system degradation and especially enforcing warranty. It needs to be noted that IEC 61215-1 (test req.), -2 (test proc.) and -1-1 (c-Si) are forecasted to be circulated end of Feb 2016 and only editorial changes would be possible. 61215 series does include thin film technologies and would be replacing 61646. Moreover, IEC 61215-1, section 7.2 power output and electric circuitry does contain significant changes to acceptance criteria regarding rated label values, particularly rated power. Even though it is believed that consensus could be achieved within IEC TC82 WG2, some of the smaller players that do not participate actively in IEC TC82 - may not be surprised and must be informed. The other tech specific parts 61215-1-2 (CdTe), -1-3 (a-Si, µc-Si) and -1-4 (CIS, CIGS) are out for comments. The IEC closing date was January 29, 2016. The additions alternative damp heat (DH) test proposed Solar Frontier is being reviewed. In the past, only 600 V systems were permitted in the grid-connected residential and commercial systems in the US. The US commercial systems can now use higher voltage (1,000-1500V) in order to reduce BOS component costs. It is believed that there would not be any problems. The Task Group 8 is collecting data on higher voltage systems.

  20. Supplement to the 2004 update of the AAPM Task Group No. 43 Report.

    Science.gov (United States)

    Rivard, Mark J; Butler, Wayne M; DeWerd, Larry A; Huq, M Saiful; Ibbott, Geoffrey S; Meigooni, Ali S; Melhus, Christopher S; Mitch, Michael G; Nath, Ravinder; Williamson, Jeffrey F

    2007-06-01

    Since publication of the 2004 update to the American Association of Physicists in Medicine (AAPM) Task Group No. 43 Report (TG-43U1), several new low-energy photon-emitting brachytherapy sources have become available. Many of these sources have satisfied the AAPM prerequisites for routine clinical use as of January 10, 2005, and are posted on the Joint AAPM/RPC Brachytherapy Seed Registry. Consequently, the AAPM has prepared this supplement to the 2004 AAPM TG-43 update. This paper presents the AAPM-approved consensus datasets for these sources, and includes the following 125I sources: Amersham model 6733, Draximage model LS-1, Implant Sciences model 3500, IBt model 1251L, IsoAid model IAI-125A, Mentor model SL-125/ SH-125, and SourceTech Medical model STM1251. The Best Medical model 2335 103Pd source is also included. While the methodology used to determine these data sets is identical to that published in the AAPM TG-43U1 report, additional information and discussion are presented here on some questions that arose since the publication of the TG-43U1 report. Specifically, details of interpolation and extrapolation methods are described further, new methodologies are recommended, and example calculations are provided. Despite these changes, additions, and clarifications, the overall methodology, the procedures for developing consensus data sets, and the dose calculation formalism largely remain the same as in the TG-43U1 report. Thus, the AAPM recommends that the consensus data sets and resultant source-specific dose-rate distributions included in this supplement be adopted by all end users for clinical treatment planning of low-energy photon-emitting brachytherapy sources. Adoption of these recommendations may result in changes to patient dose calculations, and these changes should be carefully evaluated and reviewed with the radiation oncologist prior to implementation of the current protocol.

  1. Dosimetric effects caused by couch tops and immobilization devices: report of AAPM Task Group 176.

    Science.gov (United States)

    Olch, Arthur J; Gerig, Lee; Li, Heng; Mihaylov, Ivaylo; Morgan, Andrew

    2014-06-01

    The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch top or immobilization devices is often overlooked. These devices also increase skin dose, an effect which is also often ignored or underestimated. These concerns have grown recently due to the increased use of monolithic carbon fiber couch tops which are optimal for imaging for patient position verification but cause attenuation and increased skin dose compared to the "tennis racket" style couch top they often replace. Also, arc delivery techniques have replaced stationary gantry techniques which cause a greater fraction of the dose to be delivered from posterior angles. A host of immobilization devices are available and used to increase patient positioning reproducibility, and these also have attenuation and skin dose implications which are often ignored. This report of Task Group 176 serves to present a survey of published data that illustrates the magnitude of the dosimetric effects of a wide range of devices external to the patient. The report also provides methods for modeling couch tops in treatment planning systems so the physicist can accurately compute the dosimetric effects for indexed patient treatments. Both photon and proton beams are considered. A discussion on avoidance of high density structures during beam planning is also provided. An important aspect of this report are the recommendations the authors make to clinical physicists, treatment planning system vendors, and device vendors on how to make measurements of surface dose and attenuation and how to report these values. For the vendors, an appeal is made to work together to provide accurate couch top

  2. Dosimetric effects caused by couch tops and immobilization devices: Report of AAPM Task Group 176

    Energy Technology Data Exchange (ETDEWEB)

    Olch, Arthur J., E-mail: aolch@chla.usc.edu [Radiation Oncology Department, University of Southern California and Children' s Hospital Los Angeles, Los Angeles, California 90027 (United States); Gerig, Lee [Department of Physics, Ottawa Hospital Regional Cancer Centre, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1N 6N5 (Canada); Li, Heng [Department of Radiation Physics, UT MD Anderson Cancer Center, Houston, Texas 77030 (United States); Mihaylov, Ivaylo [Department of Radiation Oncology Department, University of Miami, Miami, Florida 33136 (United States); Morgan, Andrew [The Beacon Centre, Musgrove Park Hospital, Taunton TA1 5DA (United Kingdom)

    2014-06-15

    The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch top or immobilization devices is often overlooked. These devices also increase skin dose, an effect which is also often ignored or underestimated. These concerns have grown recently due to the increased use of monolithic carbon fiber couch tops which are optimal for imaging for patient position verification but cause attenuation and increased skin dose compared to the “tennis racket” style couch top they often replace. Also, arc delivery techniques have replaced stationary gantry techniques which cause a greater fraction of the dose to be delivered from posterior angles. A host of immobilization devices are available and used to increase patient positioning reproducibility, and these also have attenuation and skin dose implications which are often ignored. This report of Task Group 176 serves to present a survey of published data that illustrates the magnitude of the dosimetric effects of a wide range of devices external to the patient. The report also provides methods for modeling couch tops in treatment planning systems so the physicist can accurately compute the dosimetric effects for indexed patient treatments. Both photon and proton beams are considered. A discussion on avoidance of high density structures during beam planning is also provided. An important aspect of this report are the recommendations the authors make to clinical physicists, treatment planning system vendors, and device vendors on how to make measurements of surface dose and attenuation and how to report these values. For the vendors, an appeal is made to work together to provide accurate couch top

  3. Comparison of the ICRP 30 models with the new models of ICRP 66 and 69 on the basis of the results of thorium incorporation monitoring of gas mantle manufactory workers by quarterly urinary bioassays; Ein Vergleich der ICRP 30 Modelle mit den Modellen der ICRP 66 und 69 anhand der Ergebnisse von Inkorporationsueberwachungen auf Thorium bei Beschaeftigten der Gasgluehkoerperproduktion durch vierteljaehrliche Urinuntersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, W. [Freie Univ. Berlin (Germany). Universitaetsklinikum Benjamin Franklin - Radiologische Diagnostik und Nuklearmedizin

    1998-12-31

    The worker in gas mantle manufacturing may be assumed to be subjected to the risk of chronic Thorium incorporation. The annual committed dose or intake, resp. may be determined from the mean intake rate determined from mean daily urinary excretion which should be derived from repeated samplings per year. The excretion data were interpretated using the excretion rates of `Retex` computer code applying the ICRP 30 model. The results basing on the ICRP 66 respiratory tract model and the biokinetic model and data of the ICRP 69 were obtained from the computer code established in the Institute of Radiation Hygiene of the Federal Board of Radiation Protection. Assuming the more soluble classes the differences between effective dose equivalent and effective dose proved to be negligible with the exception of the results for one worker but in one year. Assuming class Y or S aerosols the differences may be vary by the factor of up to four. Comparing the results of both dose sizes throughout the classes substantially extensive differences were observed. (orig.) [Deutsch] Die Umganszyklen der Beschaeftigten in der Gasgluehkoerperproduktion lassen die vereinfachende Annahme eines gleichbleibenden Inkorporationsrisikos mit dem entsprechenden chronischen Zufuhrmodell fuer die Interpretation als gerechtfertigt erscheinen. Die jaehrliche Zufuhr entspricht dem Mittelwert der aus wiederholten Messungen der Ausscheidungsrate im Urin ermittelten Zufuhrrate. Die Zufuhrermittlung aus den Messdaten entsprechend den Modellen der ICRP Veroeff. 30 erfolgt nach dem `Retex`-Computer Programm Code. Die Interpretation der Messdaten entsprechend den neuen Modellen der ICRP fuer den Atemtrakt und fuer das biokinetische Verhalten des Thoriums und seine Folgeprodukte erfolgt nach einem im Institut fuer Strahlenhygiene beim Bundesamt fuer Strahlenschutz entwickelten Computerprogramm. Die Unterschiede von effektiver Aequivalentdosis und Effektiver Dosis fuer die weniger loesliche Verbindungsklasse

  4. S values for 131I based on the ICRP adult voxel phantoms

    Science.gov (United States)

    Lamart, Stephanie; Simon, Steven L.; Bouville, Andre; Moroz, Brian E.; Lee, Choonsik

    2016-01-01

    To improve the estimates of organ doses from nuclear medicine procedures using 131I, the authors calculated a comprehensive set of 131I S values, defined as absorbed doses in target tissues per unit of nuclear transition in source regions, for different source and target combinations. The authors used the latest reference adult male and female voxel phantoms published by the International Commission on Radiological Protection (ICRP Publication 110) and the 131I photon and electron spectra from the ICRP Publication 107 to perform Monte Carlo radiation transport calculations using MCNPX2.7 to compute the S values. For each phantom, the authors simulated 55 source regions with an assumed uniform distribution of 131I. They computed the S values for 42 target tissues directly, without calculating specific absorbed fractions. From these calculations, the authors derived a comprehensive set of S values for 131I for 55 source regions and 42 target tissues in the ICRP male and female voxel phantoms. Compared with the stylised phantoms from Oak Ridge National Laboratory (ORNL) that consist of 22 source regions and 24 target regions, the new data set includes 1662 additional S values corresponding to additional combinations of source–target tissues that are not available in the stylised phantoms. In a comparison of S values derived from the ICRP and ORNL phantoms, the authors found that the S values to the radiosensitive tissues in the ICRP phantoms were 1.1 (median, female) and 1.3 (median, male) times greater than the values based on the ORNL phantoms. However, for several source–target pairs, the difference was up to 10-fold. The new set of S values can be applied prospectively or retrospectively to the calculation of radiation doses in adults internally exposed to 131I, including nuclear medicine patients treated for thyroid cancer or hyperthyroidism. PMID:25829162

  5. Factors Influencing Iranian Untrained EFL Raters' Rating Group Oral Discussion Tasks: A Mixed Methods Design

    Directory of Open Access Journals (Sweden)

    Nasimeh Nouhi Jadesi

    2016-07-01

    Full Text Available Using a mixed methods design, the present study attempted to identify the factors influencing Iranian untrained EFL raters in rating group oral discussion tasks. To fulfil this aim, 16 language learners of varying proficiency levels were selected and randomly assigned to groups of four and performed a group discussion task. Thirty two untrained raters were also selected based on their volunteer participations. They listened to the audio files of the group discussions and assigned a score of one to six to each language learners based on their own judgments. They also provided comments on each language learners’ performance pointing to why they assigned such scores. The researchers had an interview with the raters after the rating session as well. The quantitative phase investigated whether linguistic features of accuracy, fluency, complexity and amount of talk were attended to by the raters in terms of having any relationship to the scores the raters assigned. Speech rate as an index of fluency and amount of talk turned out to be significantly correlated with the scores. Of more importance was the qualitative phase with the aim of identifying other factors that may account for the scores. The comments provided by the raters on each score and the interviews were codified based on Content Analysis (CA approach. It was found that the raters attend not only to the linguistic features in rating oral group discussions, but they are also sensitive to the interactional features like the roles the participants take in groups tasks and the overall interaction patterns of the groups. The findings of this study may shed light on group oral assessment in terms of training the raters rating group oral tests and developing rating scales specific for group oral assessment. Persian Abstract:پژوهش حاضر، با بهره گیری از روش تحقیق ترکیبی به بررسی عوامل مؤثر بر ارزیابان آموزش ندیده

  6. Summary report for MEGAPIE R+D Task Group X9: Neutronic and nuclear assessment

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, L

    2005-12-15

    The comprehensive work performed by the R+D task group X9 since the beginning of the MEGAPIE initiative is described in this summary report. The list of topics covered by this group is large and covers many of the essential aspects of an innovative system such as the MEGAPIE target. The X9 group worked on the neutronic and nuclear related aspects of the target design, as summarized in the following. The main tool in the neutronic design of a spallation neutron target is a reliable particle transport code, and nowadays the Monte Carlo technique is widely adopted in this field. There are several codes which are more or less extensively used in the nuclear physics community; at the beginning of the project a benchmark exercise was performed among several institutes using different Monte Carlo codes. The aim of the benchmark was to perform a code intercomparison by looking at the different predictions of several important quantities, as described later in the report. The benchmark results were first compiled in two separate reports. The results are critically discussed here. Based on the obtained results, and considering also other factors such as the code maintenance, the codes FLUKA and MCNPX were indicated as the most recommended ones to be used in the continuation of the X9 work. Proton and neutron fluxes in the MEGAPIE target were calculated. Detailed models of he MEGAPIE target and of the surrounding SINQ facility were developed, as well as of the present solid SINQ target. A comparison between the neutron flux with MEGAPIE and the SINQ solid target showed that the MEGAPIE target sill deliver 40% to 50% more thermal neutrons to the instruments served by SINQ as compared to the SINQ Mark 3 target. Calculations of the beam power deposition distributions are essential as input for the thermohydraulics CFD analysis of the lower target. Power deposition was calculated with FLUKA and MCNPX. The results from the two codes agree within 5%. Approximately 85% of the beam

  7. Examining Preschoolers' Nutrition Knowledge Using a Meal Creation and Food Group Classification Task: Age and Gender Differences

    Science.gov (United States)

    Holub, Shayla C.; Musher-Eizenman, Dara R.

    2010-01-01

    Eating behaviours begin to develop during early childhood, but relatively little is known about preschoolers' nutrition knowledge. The current study examined age and gender differences in this knowledge using two tasks: food group classification and the creation of unhealthy, healthy and preferred meals. Sixty-nine three- to six-year-old children…

  8. Examining Preschoolers' Nutrition Knowledge Using a Meal Creation and Food Group Classification Task: Age and Gender Differences

    Science.gov (United States)

    Holub, Shayla C.; Musher-Eizenman, Dara R.

    2010-01-01

    Eating behaviours begin to develop during early childhood, but relatively little is known about preschoolers' nutrition knowledge. The current study examined age and gender differences in this knowledge using two tasks: food group classification and the creation of unhealthy, healthy and preferred meals. Sixty-nine three- to six-year-old children…

  9. Estimates of committed effective dose and annual limit on intake for radioactive dusts using the new ICRP respiratory tract model

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, R.S. [Australian Radiation Lab., Melbourne, VIC (Australia)

    1996-01-01

    This paper discusses some of the implications of using the new ICRP 66 respiratory tract model for calculation of the committed effective dose(CED), for a period of 50 years post-intake, together with the annual limit on intake(ALI), for radioactive dusts encountered in the uranium and mineral sand mining and processing industries. Some of the differences between the old ICRP 30 respiratory tract model and the LUDEP 1.1 computer code, which is based on the new ICRP 66 respiratory tract model, are discussed and a comparison of values obtained using both models is given. 4 figs; 8 tabs; 16 refs.

  10. Fairness, Teachers' Non-Task Behavior and Alumni Satisfaction: The Influence of Group Commitment

    Science.gov (United States)

    de Lara, Pablo Zoghbi Manrique

    2008-01-01

    Purpose--The purpose of this study is to examine the relationship between interactional justice, as a type of organizational justice that reflects the teachers' perceived fairness of supervisor treatment, and their non-task behavior in terms of organizational citizenship behavior (OCB) and deviant workplace behavior (DWB).…

  11. ICRP PUBLICATION 122: radiological protection in geological disposal of long-lived solid radioactive waste.

    Science.gov (United States)

    Weiss, W; Larsson, C-M; McKenney, C; Minon, J-P; Mobbs, S; Schneider, T; Umeki, H; Hilden, W; Pescatore, C; Vesterlind, M

    2013-06-01

    This report updates and consolidates previous recommendations of the International Commission on Radiological Protection (ICRP) related to solid waste disposal (ICRP, 1985, 1997b, 1998). The recommendations given apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the ICRP system of radiological protection described in Publication 103 (ICRP, 2007) can be applied in the context of the geological disposal of long-lived solid radioactive waste. Although the report is written as a standalone document, previous ICRP recommendations not dealt with in depth in the report are still valid. The 2007 ICRP system of radiological protection evolves from the previous process-based protection approach relying on the distinction between practices and interventions by moving to an approach based on the distinction between three types of exposure situation: planned, emergency and existing. The Recommendations maintains the Commission's three fundamental principles of radiological protection namely: justification, optimisation of protection and the application of dose limits. They also maintain the current individual dose limits for effective dose and equivalent dose from all regulated sources in planned exposure situations. They re-enforce the principle of optimisation of radiological protection, which applies in a similar way to all exposure situations, subject to restrictions on individual doses: constraints for planned exposure situations, and reference levels for emergency and existing exposure situations. The Recommendations also include an approach for developing a framework to demonstrate radiological protection of the environment. This report describes the different stages in the life time of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that

  12. Measuring Group Work Dynamics and Its Relation with L2 Learners' Task Motivation and Language Production

    Science.gov (United States)

    Poupore, Glen

    2016-01-01

    While learners of a second language (L2) are increasingly interacting in small groups as part of a communicative methodological paradigm, very few studies have investigated the social dynamics that occur in such groups. The aim of this study is to introduce a group work dynamic measuring instrument and to investigate the relationship between group…

  13. Application of Multi-task Sparse Group Lasso Feature Extraction and Support Vector Machine Regression in the Stellar Atmospheric Parametrization

    Science.gov (United States)

    Gao, W.; Li, X. R.

    2016-07-01

    The multi-task learning puts the multiple tasks together to analyse and calculate for discovering the correlation between them, which can improve the accuracy of analysis results. This kind of methods have been widely studied in machine learning, pattern recognition, computer vision, and other related fields. This paper investigates the application of multi-task learning in estimating the effective temperature (T_{eff}), surface gravity (lg g), and chemical abundance ([Fe/H]). Firstly, the spectral characteristics of the three atmospheric physical parameters are extracted by using the multi-task Sparse Group Lasso algorithm, and then the support vector machine is used to estimate the atmospheric physical parameters. The proposed scheme is evaluated on both Sloan stellar spectra and theoretical spectra computed from Kurucz's New Opacity Distribution Function (NEWODF) model. The mean absolute errors (MAEs) on the Sloan spectra are: 0.0064 for lg (T_{eff}/K), 0.1622 for lg (g/(cm\\cdot s^{-2})), and 0.1221 dex for [Fe/H]; The MAEs on synthetic spectra are 0.0006 for lg (T_{eff}/K), 0.0098 for lg (g/(cm\\cdot s^{-2})), and 0.0082 dex for [Fe/H]. Experimental results show that the proposed scheme is excellent for atmospheric parameter estimation.

  14. Getting behind the Scenes of Fleetwood Mac's "Rumours": Using a Documentary on the Making of a Music Album to Learn about Task Groups

    Science.gov (United States)

    Comer, Debra R.; Holbrook, Robert L., Jr.

    2012-01-01

    The authors present an efficient and easy-to-implement experiential exercise that reinforces for students key concepts about task groups (i.e., group cohesiveness, conflict within groups, group effectiveness, group norms, and group roles). The exercise, which uses a documentary about the making of Fleetwood Mac's "Rumours" album to demonstrate the…

  15. Group-level spatio-temporal pattern recovery in MEG decoding using multi-task joint feature learning.

    Science.gov (United States)

    Kia, Seyed Mostafa; Pedregosa, Fabian; Blumenthal, Anna; Passerini, Andrea

    2017-06-15

    The use of machine learning models to discriminate between patterns of neural activity has become in recent years a standard analysis approach in neuroimaging studies. Whenever these models are linear, the estimated parameters can be visualized in the form of brain maps which can aid in understanding how brain activity in space and time underlies a cognitive function. However, the recovered brain maps often suffer from lack of interpretability, especially in group analysis of multi-subject data. To facilitate the application of brain decoding in group-level analysis, we present an application of multi-task joint feature learning for group-level multivariate pattern recovery in single-trial magnetoencephalography (MEG) decoding. The proposed method allows for recovering sparse yet consistent patterns across different subjects, and therefore enhances the interpretability of the decoding model. Our experimental results demonstrate that the mutli-task joint feature learning framework is capable of recovering more meaningful patterns of varying spatio-temporally distributed brain activity across individuals while still maintaining excellent generalization performance. We compare the performance of the multi-task joint feature learning in terms of generalization, reproducibility, and quality of pattern recovery against traditional single-subject and pooling approaches on both simulated and real MEG datasets. These results can facilitate the usage of brain decoding for the characterization of fine-level distinctive patterns in group-level inference. Considering the importance of group-level analysis, the proposed approach can provide a methodological shift towards more interpretable brain decoding models. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Separation of Scaptotrigona postica workers into defined task groups by the chemical profile on their epicuticle wax layer.

    Science.gov (United States)

    Poiani, Silvana B; Morgan, E David; Drijfhout, Falko P; da Cruz-Landim, Carminda

    2014-04-01

    During evolution, the cuticle surface of insects acquired functions in communication, such as inter- and intra-specific recognition, identification of gender, physiological state, and fertility. In eusocial bees, the information in the cuticular surface is important not only to discriminate nestmates from non-nestmates but also to identify an individual's class, life phase or task. A comparative study of the cuticular surface chemical profile of workers of Scaptotrigona postica in different phases of life, i.e., newly emerged workers (NE), brood comb area workers (CA), and forager workers (FO) was undertaken by gas chromatography linked to mass spectrometry. Multivariate statistical analysis was performed to verify how workers are grouped according to their chemical profile and to determine which compounds are responsible for separating them into groups. The cuticle surface of workers contains mainly hydrocarbons and a small amount of oxygenated compounds. Multivariate statistical analysis showed qualitative and quantitative variation in relation to the life phases/tasks performed, and all groups were distinct. The most abundant compound found in NE and CA was n-heptacosane, while in FO, it was (Z)-9-heptacosene. The compounds that differentiate NE from other groups are n-tricosane and n-hexacosane. A (Z)-X-octacosene and n-nonacosane are the chemicals that distinguish CA from NE and FO, while 11- and 13-methylpentacosane, (Z)-X-hexacosene, and (Z)-9-heptacosene characterize FO as distinct from NE and CA. The probable function of alkenes is nestmate recognition, mainly in FO. The results show that the cuticle surfaces of workers are characteristic of the phase of life/task performed by workers, allowing intra-colonial recognition.

  17. Minimal intervention dentistry for managing dental caries - a review: report of a FDI task group.

    Science.gov (United States)

    Frencken, Jo E; Peters, Mathilde C; Manton, David J; Leal, Soraya C; Gordan, Valeria V; Eden, Ece

    2012-10-01

    This publication describes the history of minimal intervention dentistry (MID) for managing dental caries and presents evidence for various carious lesion detection devices, for preventive measures, for restorative and non-restorative therapies as well as for repairing rather than replacing defective restorations. It is a follow-up to the FDI World Dental Federation publication on MID, of 2000. The dental profession currently is faced with an enormous task of how to manage the high burden of consequences of the caries process amongst the world population. If it is to manage carious lesion development and its progression, it should move away from the 'surgical' care approach and fully embrace the MID approach. The chance for MID to be successful is thought to be increased tremendously if dental caries is not considered an infectious but instead a behavioural disease with a bacterial component. Controlling the two main carious lesion development related behaviours, i.e. intake and frequency of fermentable sugars, to not more than five times daily and removing/disturbing dental plaque from all tooth surfaces using an effective fluoridated toothpaste twice daily, are the ingredients for reducing the burden of dental caries in many communities in the world. FDI's policy of reducing the need for restorative therapy by placing an even greater emphasis on caries prevention than is currently done, is therefore, worth pursuing.

  18. Solvent Extraction of Yttrium by Task-specific Ionic Liquids Bearing Carboxylic Group

    Institute of Scientific and Technical Information of China (English)

    王威; 刘郁; 徐爱梅; 杨华玲; 崔红敏; 陈继

    2012-01-01

    A new kind of hydrophobic ionic liquids [1-alkyl-3-(1-carboxylpropyl)im][PF6] has been synthesized, and their extraction.properties for Y(III) in the nitric acid medium was also investigated. The effects of extractant concentration, equilibrium pH of aqueous phase, salt concentration, temperature etc. were discussed. The results show that this kind of Task-Specific Ionic Liquid (TSIL) needs to be saponified before being used for the Y(III) extraction, and the extraction is-acid dependent,-and the extraction efficiency increases with the aqueous phase acldity decreasing. Furthermore, the loaded organic phase is easy to be stripped; more than 95% Y(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol-L-1. The slope analysis technique is used to investigate the extraction mechanism, and a possible cation-exchange extraction mechanism is proposed in the oresent extraction system.

  19. The Effects of Group Relaxation Training/Large Muscle Exercise, and Parental Involvement on Attention to Task, Impulsivity, and Locus of Control among Hyperactive Boys.

    Science.gov (United States)

    Porter, Sally S.; Omizo, Michael M.

    1984-01-01

    The study examined the effects of group relaxation training/large muscle exercise and parental involvement on attention to task, impulsivity, and locus of control among 34 hyperactive boys. Following treatment both experimental groups recorded significantly higher attention to task, lower impulsivity, and lower locus of control scores. (Author/CL)

  20. Facilitating Group Analysis of Two Case Studies Utilising Peer Tutoring: Comparison of Tasks and Outcomes

    Science.gov (United States)

    Fong, Lin Siew

    2016-01-01

    Peer-tutoring sessions of two groups of advanced diploma in financial accounting students with mixed proficiency were analysed thoroughly in this study. Numerous studies in peer tutoring have produced favourable results to both tutors and tutees due to the scaffolding process which promotes effective learning. However, there is a lack of studies…

  1. Group Tasks, Activities, Dynamics, and Interactions in Collaborative Robotics Projects with Elementary and Middle School Children

    Science.gov (United States)

    Yuen, Timothy T.; Boecking, Melanie; Stone, Jennifer; Tiger, Erin Price; Gomez, Alvaro; Guillen, Adrienne; Arreguin, Analisa

    2014-01-01

    Robotics provide the opportunity for students to bring their individual interests, perspectives and areas of expertise together in order to work collaboratively on real-world science, technology, engineering and mathematics (STEM) problems. This paper examines the nature of collaboration that manifests in groups of elementary and middle school…

  2. The report of Task Group 100 of the AAPM: Application of risk analysis methods to radiation therapy quality management.

    Science.gov (United States)

    Huq, M Saiful; Fraass, Benedick A; Dunscombe, Peter B; Gibbons, John P; Ibbott, Geoffrey S; Mundt, Arno J; Mutic, Sasa; Palta, Jatinder R; Rath, Frank; Thomadsen, Bruce R; Williamson, Jeffrey F; Yorke, Ellen D

    2016-07-01

    The increasing complexity of modern radiation therapy planning and delivery challenges traditional prescriptive quality management (QM) methods, such as many of those included in guidelines published by organizations such as the AAPM, ASTRO, ACR, ESTRO, and IAEA. These prescriptive guidelines have traditionally focused on monitoring all aspects of the functional performance of radiotherapy (RT) equipment by comparing parameters against tolerances set at strict but achievable values. Many errors that occur in radiation oncology are not due to failures in devices and software; rather they are failures in workflow and process. A systematic understanding of the likelihood and clinical impact of possible failures throughout a course of radiotherapy is needed to direct limit QM resources efficiently to produce maximum safety and quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and has developed a framework for designing QM activities, based on estimates of the probability of identified failures and their clinical outcome through the RT planning and delivery process. The Task Group has chosen a specific radiotherapy process required for "intensity modulated radiation therapy (IMRT)" as a case study. The goal of this work is to apply modern risk-based analysis techniques to this complex RT process in order to demonstrate to the RT community that such techniques may help identify more effective and efficient ways to enhance the safety and quality of our treatment processes. The task group generated by consensus an example quality management program strategy for the IMRT process performed at the institution of one of the authors. This report describes the methodology and nomenclature developed, presents the process maps, FMEAs, fault trees, and QM programs developed, and makes suggestions on how this information could be used in the clinic. The development and implementation of risk-assessment techniques will make radiation therapy

  3. Simulation of the respiratory model of tract of Publication 66 of the ICRP and their use in biological analysis; Simulacion del modelo de tracto respiratorio de la Publicacion 66 de la ICRP y su utilizacion en bioanalisis

    Energy Technology Data Exchange (ETDEWEB)

    Puerta, A. [Universidad Nacional de Colombia, Medellin (Colombia). Facultad de Ciencias. Dept. de Fisica; Bertelli, L.; Lipsztein, J. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    2001-07-01

    The International Commission Radiological Protection, ICRP in its publications 67, 68, 69 and 71 provides the loss of systematic activity of the radioactive materials by the routes of excretion and recirculation, as well as effective dose by incorporation unit coefficient, using the model of respiratory tract proposed by the ICRP, in its Publication 66, but it does not provide information on as these models in biological analysis are used. There are some specific studies for inhalation of uranium compounds made by Bertelli and collaborators using the new model of the lung. In this work it have been done a simulation of the model of respiratory tract of ICRP 66 of such form that it can be used in-vitro and in-vivo biological analysis. In order to verify the simulation were used systemic models for adult of planuin, lead, uranium, bismuth and their respective descendants and the comparison with the coefficients of dose provided by the ICRP. Finally, it shows the estimation of the temporary distribution of activity in devices and the excrete of these radionuclides and in addition the model for gases and steam in the conditions is verified that the ICRP proposes.

  4. Quality assurance of U.S.-guided external beam radiotherapy for prostate cancer: report of AAPM Task Group 154.

    Science.gov (United States)

    Molloy, Janelle A; Chan, Gordon; Markovic, Alexander; McNeeley, Shawn; Pfeiffer, Doug; Salter, Bill; Tome, Wolfgang A

    2011-02-01

    Task Group 154 (TG154) of the American Association of Physicists in Medicine (AAPM) was created to produce a guidance document for clinical medical physicists describing recommended quality assurance (QA) procedures for ultrasound (U.S.)-guided external beam radiotherapy localization. This report describes the relevant literature, state of the art, and briefly summarizes U.S. imaging physics. Simulation, treatment planning and treatment delivery considerations are presented in order to improve consistency and accuracy. User training is emphasized in the report and recommendations regarding peer review are included. A set of thorough, yet practical, QA procedures, frequencies, and tolerances are recommended. These encompass recommendations to ensure both spatial accuracy and image quality.

  5. Dose estimate of inhaled hafnium tritide using the ICRP 66 lung model.

    Science.gov (United States)

    Cheng, Yung-Sung; Zhou, Yue; Wang, Yang-Sheng; Inkret, William C; Wermer, Joseph R

    2002-06-01

    Metal tritide is widely used for research, purification, compression, and storage of tritium. The current understanding of metal tritide and its radiation dosimetry for internal exposure is limited, and ICRP publications do not provide the tritium dosimetry for hafnium tritide. The current radiation protection guidelines for metal tritide particles (including hafnium tritide) are based on the assumption that their biological behavior is similar to tritiated water, which is completely absorbed by the body. However, the solubility of metal tritide particles depends on the chemical form of the material. The biological half-live of hafnium tritide particles and the dosimetry of an inhalation exposure to those particles could be quite different from tritiated water. This paper describes experiments on the dissolution rate of hafnium tritide particles in a simulated lung fluid. The results showed that less than 1% of the tritium was dissolved in the simulated lung fluid for hafnium tritide particles after 215 d. The short-term and long-term dissolution half times were 46 and 4.28 x 10(5) d, respectively. This indicates that hafnium tritide is an extremely insoluble material. Self-absorption of beta rays in the hafnium tritide particles was estimated by a numerical method. The dose coefficients were calculated as a function of particle size using in vitro solubility data and a calculated self-absorption factor. The dose coefficient decreased with aerodynamic diameters in the range of 0.25 to 10 microm, mainly because the self-absorption factor decreased with increasing particle size. For a particle 1 microm in aerodynamic diameter, the dose coefficient of a hafnium tritide particle was about 10 times higher than that of tritiated water but was about 1.4 times lower than that calculated by ICRP Publication 71 for Type S tritiated particles. The ICRP estimate did not include a self-absorption factor and thus might have overestimated the dose. This finding has significant

  6. The ICRP protection quantities, equivalent and effective dose: their basis and application

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, J.D. [Health Protection Agency, Radiation Protection Division, Chilton, Didcot, Oxon OX11 0RQ (United Kingdom); Streffer, C. [Institute for Science and Ethics, University Duisburg-Essen, 45117 Essen (Germany)

    2007-07-01

    Equivalent and effective dose are protection quantities defined by the The International Commission on Radiological Protection (ICRP). They are frequently referred to simply as dose and may be misused. They provide a method for the summation of doses received from external sources and from intakes of radionuclides for comparison with dose limits and constraints, set to limit the risk of cancer and hereditary effects. For the assessment of internal doses, ICRP provides dose coefficients (Sv Bq{sup -1}) for the ingestion or inhalation of radionuclides by workers and members of the public, including children. Dose coefficients have also been calculated for in utero exposures following maternal intakes and for the transfer of radionuclides in breast milk. In each case, values are given of committed equivalent doses to organs and tissues and committed effective dose. Their calculation involves the use of defined biokinetic and dosimetric models, including the use of reference phantoms representing the human body. Radiation weighting factors are used as a simple representation of the different effectiveness of different radiations in causing stochastic effects at low doses. A single set of tissue weighting factors is used to take account of the contribution of individual organs and tissues to overall detriment from cancer and hereditary effects, despite age- and gender-related differences in estimates of risk and contributions to risk. The results are quantities that are not individual specific but are reference values for protection purposes, relating to doses to phantoms. The ICRP protection quantities are not intended for detailed assessments of dose and risk to individuals. They should not be used in epidemiological analyses or the assessment of the possibility of occurrence and severity of tissue reactions (deterministic effects) at higher doses. Dose coefficients are published as reference values and as such have no associated uncertainty. Assessments of

  7. Selected organ dose conversion coefficients for external photons calculated using ICRP adult voxel phantoms and Monte Carlo code FLUKA.

    Science.gov (United States)

    Patni, H K; Nadar, M Y; Akar, D K; Bhati, S; Sarkar, P K

    2011-11-01

    The adult reference male and female computational voxel phantoms recommended by ICRP are adapted into the Monte Carlo transport code FLUKA. The FLUKA code is then utilised for computation of dose conversion coefficients (DCCs) expressed in absorbed dose per air kerma free-in-air for colon, lungs, stomach wall, breast, gonads, urinary bladder, oesophagus, liver and thyroid due to a broad parallel beam of mono-energetic photons impinging in anterior-posterior and posterior-anterior directions in the energy range of 15 keV-10 MeV. The computed DCCs of colon, lungs, stomach wall and breast are found to be in good agreement with the results published in ICRP publication 110. The present work thus validates the use of FLUKA code in computation of organ DCCs for photons using ICRP adult voxel phantoms. Further, the DCCs for gonads, urinary bladder, oesophagus, liver and thyroid are evaluated and compared with results published in ICRP 74 in the above-mentioned energy range and geometries. Significant differences in DCCs are observed for breast, testis and thyroid above 1 MeV, and for most of the organs at energies below 60 keV in comparison with the results published in ICRP 74. The DCCs of female voxel phantom were found to be higher in comparison with male phantom for almost all organs in both the geometries.

  8. Development of derived limits for radiological protection against ionizing radiation based on ICRP-60 recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Jang, S. Y.; Lee, B. S. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1999-07-01

    Derived limits such as the Annual Limit on Intake (ALI), Derived Air Concentration (DAC) and Effluent Concentration Limit (ECL) for radiological protection against ionizing radiation based on ICRP-60 recommendations were calculated using dose limits and committed effective dose coefficients of the basic Safety Standards of IAEA (i.e. safety series 115; BSS-96). Derived limits regarding occupational exposure were derived using methodologies of ICRP-61 and dose limit stated in ICRP -60. ECL in air and water for the control of radioactive discharge into the environment were derived using methodologies of 10 CFR part 20 and dose limit stated in ICRP-60. In order to analyze the impact of implementing derived limits on nuclear facilities, the derived values in this study were compared with those prescribed in 10 CFR part 20 as well as the Maximum Permissible Concentrations (MPC) of Notice No. 98-12 of the Ministry of Science and Technology (MOST). According to the comparison results, ECLs in air and water for the control of radioactive discharge into the environment in this study are shown to have lower values (i.e. more conservative), for most part, than those in Notice No. 98-12. These differences are due to the reduction of dose limit, adoption of a weighting factor for age-dependency in dose coefficients, and application of new respiratory tract model and bio-kinetics model. Especially, for uranium elements (i.e., {sup 235}U, {sup 238}U, etc.), which are governing ones in the nuclear fuel industries, ECLs in water are approximately a magnitude in the order of two lower than those in Notice No. 98-12. These are attributable to the adoption of a weighting factor for age-dependency in dose coefficients, newly recommended dose coefficients for ingestion pathway, and reduction of dose limit. It was found out that the differences in ECLs in water for uranium elements originated mostly from ingestion dose coefficients recommended by BSS-96. (author). 6 refs., 2 tabs., 5

  9. Range Commanders Council Meteorology Group 88th Meeting: NASA Marshall Space Flight Center Task Report, 2004

    Science.gov (United States)

    Roberts, Barry C.

    2004-01-01

    Supported Return-to-Flight activities by providing surface climate data from Kennedy Space Center used primarily for ice and dew formation studies, and upper air wind analysis primarily used for ascent loads analyses. The MSFC Environments Group's Terrestrial and Planetary Environments Team documented Space Shuttle day-of-launch support activities by publishing a document in support of SSP Return-to-Flight activities entitled "Space Shuttle Program Flight Operations Support". The team also formalized the Shuttle Natural Environments Technical Panel and chaired the first special session of the SSP Natural Environments Panel meeting at KSC, November 4-7,2003.58 participants from NASA, DOD and other government agencies from across the country attended the meeting.

  10. Adapting the Crossmodal Congruency Task for Measuring the Limits of Visual-Tactile Interactions Within and Between Groups.

    Science.gov (United States)

    Poole, Daniel; Couth, Samuel; Gowen, Emma; Warren, Paul A; Poliakoff, Ellen

    2015-01-01

    The crossmodal congruency task (CCT) is a commonly used paradigm for measuring visual-tactile interactions and how these may be influenced by discrepancies in space and time between the tactile target and visual distractors. The majority of studies which have used this paradigm have neither measured, nor attempted to control, individual variability in unisensory (tactile) performance. We have developed a version of the CCT in which unisensory baseline performance is constrained to enable comparisons within and between participant groups. Participants were instructed to discriminate between single and double tactile pulses presented to their dominant hand, at their own approximate threshold level. In Experiment 1, visual distractors were presented at -30 ms, 100 ms, 200 ms and 400 ms stimulus onset asynchronies. In Experiment 2, ipsilateral visual distractors were presented 0 cm, 21 cm, and 42 cm vertically from the target hand, and 42 cm in a symmetrical, contralateral position. Distractors presented -30 ms and 0 cm from the target produced a significantly larger congruency effect than at other time points and spatial locations. Thus, the typical limits of visual-tactile interactions were replicated using a version of the task in which baseline performance can be constrained. The usefulness of this approach is supported by the observation that tactile thresholds correlated with self-reported autistic traits in this non-clinical sample. We discuss the suitability of this adapted version of the CCT for measuring visual-tactile interactions in populations where unisensory tactile ability may differ within and between groups.

  11. Two Paths from the Same Place: Task Driven and Human Centered Evolution of a Group Information Surface

    Science.gov (United States)

    Russell, Daniel M.; Trimble, Jay; Wales, Roxana; Clancy, Daniel (Technical Monitor)

    2003-01-01

    This is the tale of two different implementations of a collaborative information tool, that started from the same design source. The Blueboard, developed at IBM Research, is a tool for groups to use in exchanging information in a lightweight, informal collaborative way. It began as a large display surface for walk-by use in a corporate setting and has evolved in response to task demands and user needs. At NASA, the MERBoard is being designed to support surface operations for the upcoming Mars Exploration Rover Missions. The MERBoard is a tool that was inspired by the Blueboard design, extending this design to support the collaboration requirements for viewing, annotating, linking and distributing information for the science and engineering teams that will operate two rovers on the surface of Mars. The ways in which each group transformed the system reflects not only technical requirements, but also the needs of users in each setting and embedding of the system within the larger socio-technical environment. Lessons about how task requirements, information flow requirements and work practice drive the evolution of a system are illustrated.

  12. Summary report for MEGAPIE R+D Task Group X4: Fluid dynamics and structure mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B. L

    2006-03-15

    The document chronicles, and draws summary conclusions from, the activities of the X4 R+D Support Group from the start of the project on January 1, 2000 to the time of the Technical Review Meeting in Mol: 27-29 June, 2005. The objectives to be accomplished were set out in a Baseline document. These were: to define the lower target flow configuration, within the geometric constraints imposed by the physical boundary conditions (geometrical confinement, lead- bismuth eutectic (LBE) inventory, pump capacities, target heat exchanger (THX) power, etc.); to identify, and evaluate, optimum target window design to minimise thermal loads and pressure drops, and to avoid hot-spots and flow instabilities; to demonstrate reliable cooling of the lower target enclosure (LTE); to demonstrate the structural integrity of the lower section of the Iiquid-metal container LMC) and its internal components, and that of the LTE; to provide best-estimate safety margins on target coolability and structural integrity under operational flow conditions; to investigate, quantify, and make recommendations regarding, abnormal target operation including possible accident scenarios). The time-scale set for MEGAPIE was always such that much of the design work needed to be carried out at the same time as the R+D support. Often, the target design was changing faster than the time required to perform the detailed computer simulations. As a consequence, many of the simulations reported or referenced in this document do not refer to the very latest target design, and in many respects the results and conclusions must be regarded as generic in nature. Nonetheless, very valuable work has been carried out by the various organisations, and better understanding of the expected temperature distributions and stress levels in the operating MEGAPIE target has been gained, and direct feed-back to the design team on various aspects of the design details has taken place as a consequence of this work. As the design

  13. Extrapolating Accelerated UV Weathering Data: Perspective From PVQAT Task Group 5 (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.; Annigoni, E.; Ballion, A.; Bokria, J.; Bruckman, L.; Burns, D.; Elliott, L.; French, R.; Fowler, S.; Gu, X.; Honeker, C.; Khonkar, H.; Kohl, M.; Krommenhoek, P.; Peret-Aebi, L.; Phillips, N.; Scott, K.; Sculati-Meillaud, F.; Shioda, T.

    2015-02-01

    Taskgroup 5 (TG5) is concerned with a accelerated aging standard incorporating factors including ultraviolet radiation, temperature, and moisture. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for the TG5 interlaboratory study being directed out of the USA. Qualitative preliminary data from the experiment is presented. To date, the encapsulation transmittance experiment has: replicated behaviors of fielded materials (including specimen location- and formulation additive-specific discoloration); demonstrated coupling between UV aging and temperature; demonstrated that degradation in EVA results from UV- aging; and obtained good qualitative comparison between Xe and UVA-340 sources for EVA. To date, the encapsulation adhesion experiment (using the compressive shear test to quantify strength of attachment) has demonstrated that attachment strength can decrease drastically (>50%) with age; however, early results suggest significant factor (UV, T, RH) dependence. Much remains to be learned about adhesion.

  14. Waste area Grouping 2 Phase I task data report: Human health risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Purucker, S.T.; Douthat, D.M.

    1996-06-01

    This report is one of five reports issued in 1996 that provide follow- up information to the Phase 1 Remedial Investigation (RI) Report for Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL). The five reports address areas of concern that could cause potential human health risk and ecological risk within WAG2 at ORNL. The purpose of this report is to present a summary of the human health risk assessment results based on the data collected for the WAG 2 Phase 1 RI. Estimates of risk are provided based on measured concentrations in the surface water, floodplain soil, and sediment of White Oak Creek, Melton Branch, and their tributaries. The human health risk assessment methodology used in this risk assessment is based on Risk Assessment Guidance for Superfund (RAGS). First, the data for the different media are elevated to determine usability for risk assessment. Second, through the process of selecting chemicals of potential concern (COPCs), contaminants to be considered in the risk assessment are identified for each assessment of exposure potential is performed, and exposure pathways are identified. Subsequently, exposure is estimated quantitatively, and the toxicity of each of the COPCs is determined. The results of these analyses are combined and summarized in a risk characterization.

  15. Radiation safety concerns for pregnant or breast feeding patients. The positions of the NCRP and the ICRP

    Energy Technology Data Exchange (ETDEWEB)

    Meinhold, C.B. [Brookhaven National Lab., Upton, NY (United States)

    1997-01-01

    For many years, protecting the fetus has been a concern of the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP). Early recommendations focused on the possibility of a wide variety of detrimental developmental effects while later recommendations focused on the potential for severe mental retardation and/or reduction in the intelligence quotient (I.Q.). The latest recommendations also note that the risk of cancer for the fetus is probably two to three times greater per Sv than in the adult. For all these reasons, the NCRP and the ICRP have provided guidance to physicians on taking all reasonable steps to ascertain whether any woman requiring a radiological or nuclear medicine procedure is pregnant or nursing a child. The NCRP and the ICRP also advise the clinician to postpone such procedures until after delivery or cessation of nursing, if possible.

  16. Monte Carlo based water/medium stopping-power ratios for various ICRP and ICRU tissues.

    Science.gov (United States)

    Fernández-Varea, José M; Carrasco, Pablo; Panettieri, Vanessa; Brualla, Lorenzo

    2007-11-07

    Water/medium stopping-power ratios, s(w,m), have been calculated for several ICRP and ICRU tissues, namely adipose tissue, brain, cortical bone, liver, lung (deflated and inflated) and spongiosa. The considered clinical beams were 6 and 18 MV x-rays and the field size was 10 x 10 cm(2). Fluence distributions were scored at a depth of 10 cm using the Monte Carlo code PENELOPE. The collision stopping powers for the studied tissues were evaluated employing the formalism of ICRU Report 37 (1984 Stopping Powers for Electrons and Positrons (Bethesda, MD: ICRU)). The Bragg-Gray values of s(w,m) calculated with these ingredients range from about 0.98 (adipose tissue) to nearly 1.14 (cortical bone), displaying a rather small variation with beam quality. Excellent agreement, to within 0.1%, is found with stopping-power ratios reported by Siebers et al (2000a Phys. Med. Biol. 45 983-95) for cortical bone, inflated lung and spongiosa. In the case of cortical bone, s(w,m) changes approximately 2% when either ICRP or ICRU compositions are adopted, whereas the stopping-power ratios of lung, brain and adipose tissue are less sensitive to the selected composition. The mass density of lung also influences the calculated values of s(w,m), reducing them by around 1% (6 MV) and 2% (18 MV) when going from deflated to inflated lung.

  17. Internal Dose Calculations with the New Biokinetic Models of the ICRP

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, I.; Shamai, Y.; Schlesinger, T.; Biran, T

    1999-07-01

    During the past decade, the ICRP made major revisions in its recommendations regarding protection from ionising radiation and advised the use of new models for estimating doses due to intake of radionuclides. A new Internal Dosimetry code (InDose) is presented which employs all the new biokinetic models together with the new respiratory tract (RT) model and the gastrointestinal tract (GI) model. The code makes use of a generalised form of these new biokinetic models which enables the use of any of them. The code has been used to assess intakes and doses for the 3rd European Intercomparison Exercise on Internal Dose Assessment. A detailed study of one of the test cases of this exercise is presented. Our code using the new plutonium biokinetic model and LUDEP gave similar results. InDose, however, provides a way to insert consistent changes in the models in orderto make estimations under non-standard conditions. The new biokinetic model has been found to give better agreement with measured data than the old (ICRP 30) model. (author)

  18. Accumulation of plutonium in mammalian wildlife tissues: comparison of recent data with the ICRP distribution models

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, M.; Child, D.; Davis, E.; Hotchkis, M.; Payne, T. [Australian Nuclear Science and Technology Org. (Australia); Ikeda-Ohno, A. [University of New South Wales (Australia); Twining, J. [Austral Radioecology (Australia)

    2014-07-01

    We examined the distribution of plutonium (Pu) in the tissues of mammalian wildlife to address the paucity of such data under environmental exposure conditions. Pu activity concentrations were measured in Macropus rufus (red kangaroo), Oryctolagus cuniculus (European rabbit), and Pseudomys hermannsburgensis (sandy inland mouse)inhabiting the relatively undisturbed, semi-arid conditions at the former Taranaki weapons test site at Maralinga, Australia. Of the absorbed Pu (distributed via circulatory and lymph systems) accumulation was foremost in bone (83% ±10% SD), followed by muscle (9% ±10%), liver (7% ±7%), kidneys (0.5% ±0.3%), and heart (0.4% ±0.4%). The bone values are higher than those reported in ICRP 19 and 48 (45-50% bone), while the liver values are lower than ICRP values (30-45% liver). The ICRP values were based on data dominated by relatively soluble forms of Pu, including prepared solutions and single-atom ions produced by decay following the volatilisation of uranium during nuclear detonation (fallout Pu, ICRP 1986). In contrast, the Maralinga data relates to low-soluble forms of Pu used in tests designed to simulate accidental release and dispersal. We measured Pu in lung, GI-tract and the skin and fur as distinct from the absorbed Pu in bone, liver, muscle, and kidneys. Compared with the mean absorbed activity concentrations, the results for lung tissues were higher by up to one order of magnitude, and those in the GI tract contents and the washed skin/fur were higher by more than two orders of magnitude. These elevated levels are consistent with the presence of low-soluble Pu, including particulate forms, which pass through, or adhere upon, certain organs, but are not readily absorbed into the bloodstream. This more transitory Pu can provide dose to the lung and GI tract organs, as well as provide potential transfer of contamination when consumed in predator-prey food chains, or during human foodstuff consumption. For example, activity

  19. Fuel Hedging Task Group

    Science.gov (United States)

    2004-03-01

    scandals such as Enron are possible. • Government is already “self-hedged”: – OMB considers the federal government to be “self-hedged” on...this approach should involve none of the potential political embarrassment associated with comparisons to Enron and payment of hedging fees to

  20. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, John P., E-mail: john.gibbons@marybird.com [Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana 70809 (United States); Antolak, John A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Followill, David S. [Department of Radiation Physics, UT M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Klein, Eric E. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Lam, Kwok L. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Palta, Jatinder R. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Roback, Donald M. [Department of Radiation Oncology, Cancer Centers of North Carolina, Raleigh, North Carolina 27607 (United States); Reid, Mark [Department of Medical Physics, Fletcher-Allen Health Care, Burlington, Vermont 05401 (United States); Khan, Faiz M. [Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-03-15

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D{sub 0}{sup ′}, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D{sub 0}{sup ′} = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D{sub 0}{sup ′} ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of d{sub m}, with D{sub 0}{sup ′} = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  1. SU-E-T-273: Do Task Group External Beam QA Recommendations Guarantee Accurate Treatment Plan Dose Delivery?

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, A; Liao, Y; Redler, G; Zhen, H [Rush University Medical Center, Chicago, IL (United States)

    2015-06-15

    Purpose: AAPM task groups 40/142 have provided an invaluable set of goals for physicists designing QA programs, attempting to standardize what would otherwise likely be a highly variable phenomenon across institutions. However, with the complexity of modalities such as VMAT, we hypothesize that following these guidelines to the letter might still allow unacceptable dose discrepancies. To explore this hypothesis we simulated machines bordering on QA acceptability, and calculated the effect on patient plans. Methods: Two errant machines were simulated in Aria/Eclipse, each just within task group criteria for output, percent depth dose, beam profile, gantry and collimator rotations, and jaw and MLC positions. One machine minimized dose to the PTV (machine A) and the other maximized dose to the OARs (machine B). Clinical treatment plans (3-phase prostate, n=3; hypofractionated lung, n=1) were calculated on these machines and the dose distributions compared. A prostate case was examined for contribution of error sources and evaluated using delivery QA data. Results: The prostate plans showed mean decreases in target D95 of 9.9% of prescription dose on machine A. On machine B, The rectal and bladder V70Gy each increased by 7.1 percentage points, while their V45Gy increased by 16.2% and 15.0% respectively. In the lung plan, the target D95 decreased by 12.8% and the bronchial tree Dmax increased by 21% of prescription dose, on machines A and B. One prostate plan showed target dose errors of 3.8% from MLC changes, 2% from output, ∼3% from energy and ∼0.5% from other factors. This plan achieved an 88.4% gamma passing rate using 3%/3mm using ArcCHECK. Conclusion: In the unlikely event that a machine exhibits all maximum errors allowed by TG 40/142, unacceptably large changes in dose delivered are possible especially in highly modulated VMAT plans, despite the machine passing routine QA.

  2. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71.

    Science.gov (United States)

    Gibbons, John P; Antolak, John A; Followill, David S; Huq, M Saiful; Klein, Eric E; Lam, Kwok L; Palta, Jatinder R; Roback, Donald M; Reid, Mark; Khan, Faiz M

    2014-03-01

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D'0, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D'0 = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D'0 ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D'0 = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  3. Towards a coherent conceptual framework for emergency preparedness/response and rehabilitation - the application of the new ICRP recommendations given in ICRP 103

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W., E-mail: wweiss@bfs.d [Federal Office for Radiation Protection, Department Radiation Protection and Health, 85764 Oberschleissheim (Germany)

    2009-12-15

    In the past, most emphasis in planning for and response to an emergency situation has been placed on selected protective measures in the early phase of an emergency to keep the doses received below levels where severe deterministic health effects can be excluded and/or where the risk of stochastic effects in the population is considered 'acceptable'. Less emphasis has been placed on the development of comprehensive protection strategies which include considerations of the consequences of all exposure pathways and all phases, e.g. long-term rehabilitation. In its new publication 103, ICRP proposed a coherent conceptual framework for protection in all types of exposure situations including 'emergency exposure situations' and 'existing exposure situations'. In the context of developing protection strategies for these exposure situations, the Commission recommends that national authorities set reference levels between, typically, 20 mSv and 100 mSv annual effective dose (emergency exposure situation) and 1 mSv and 20 mSv (existing exposure situation). In order to optimise protection strategies, it is necessary to identify the dominant exposure pathways, the timescales over which the dose will be received, and the effectiveness of available protection options. The characteristics of the development and implementation of such protection strategies is described.

  4. Influences of parameter uncertainties within the ICRP 66 respiratory tract model: particle deposition.

    Science.gov (United States)

    Bolch, W E; Farfán, E B; Huh, C; Huston, T E; Bolch, W E

    2001-10-01

    Risk assessment associated with the inhalation of radioactive aerosols requires as an initial step the determination of particle deposition within the various anatomic regions of the respiratory tract. The model outlined in ICRP Publication 66 represents to date one of the most complete overall descriptions of not only particle deposition, but of particle clearance and local radiation dosimetry of lung tissues. In this study, a systematic review of the deposition component within the ICRP 66 respiratory tract model was conducted in which probability density functions were assigned to all input parameters. These distributions were subsequently incorporated within a computer code LUDUC (LUng Dose Uncertainty Code) in which Latin hypercube sampling techniques are used to generate multiple (e.g., 1,000) sets of input vectors (i.e., trials) for all of the model parameters needed to assess particle deposition within the extrathoracic (anterior and posterior), bronchial, bronchiolar, and alveolar-interstitial regions of the ICRP 66 respiratory tract model. Particle deposition values for the various trial simulations were shown to be well described by lognormal probability distributions. Geometric mean deposition fractions from LUDUC were found to be within approximately +/- 10% of the single-value estimates from the LUDEP computer code for each anatomic region and for particle diameters ranging from 0.001 to 50 microm. In all regions of the respiratory tract, LUDUC simulations for an adult male at light exertion show that uncertainties in particle deposition fractions are distributed only over a range of about a factor of approximately 2-4 for particle sizes between 0.005 to 0.2 microm. Below 0.005 microm, uncertainties increase only for deposition within the alveolar region. At particle sizes exceeding 1 microm, uncertainties in the deposition fraction within the extrathoracic regions are relatively small, but approach a factor of 20 for deposition in the bronchial

  5. ICRP 67 Biokinetic Models for AM-241 Applied to Nonhuman Primates.

    Science.gov (United States)

    Alomairy, Nada A; Brey, Richard R; Guilmette, Raymond A

    2017-05-01

    Between 1960 and 1985, Patricia Durbin and colleagues performed studies on the distribution of intravenously and intramuscularly injected Am citrate with dosages ranging from 16 to 32 kBq kg in 30 male and female non-human primates (NHP). Dr. Durbin died unexpectedly in March of 2009, leaving much of the extensive serial blood, bioassay, and autopsy data from these NHP studies unanalyzed. As part of the experimental design, serial blood samples were taken, and urine and feces samples were collected separately for the duration of the study. The measurements of urine, fecal excretion, blood samples, and organ burden data obtained from the animals were used to evaluate the transfer rates of the ICRP 67 biokinetic model for Am. Seven cases, in which the primates were administered Am citrate by intravenous injection, were evaluated using the ICRP 67 systemic model. There were differences ranging from 51.4% underestimated to 102.7% overestimated activity between the predicted intake, which was calculated using IMBA Professional Plus software and based upon the urine bioassay data and the actual activity. The difference between the predicted activity at the time of death in the liver and skeleton using IMBA professional software and the value of the measured activity at the time of death were also compared. Generally, the ratios of predicted activity in the liver and skeleton at the time of death to the measured activity were consistently more than 1. However, the ratios were less than 1 in the skeleton for animals that were sacrificed 2,199 and 973 d post injection. The posterior probability distributions for model parameters derived using WeLMoS method were inconsistent with the ICRP 67 default parameters. The prediction made based on the posterior probability distributions for model parameters derived using WeLMoS gave the best fit to these data; however, the modified parameters overestimated the activity in almost all cases. The difference between the predicted Am

  6. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K., E-mail: tarun.podder@uhhospitals.org [Department of Radiation Oncology, University Hospitals, Case Western Reserve University, Cleveland, Ohio 44122 (United States); Beaulieu, Luc [Department of Radiation Oncology, Centre Hospitalier Univ de Quebec, Quebec G1R 2J6 (Canada); Caldwell, Barrett [Schools of Industrial Engineering and Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Cormack, Robert A. [Department of Radiation Oncology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Crass, Jostin B. [Department of Radiation Oncology, Vanderbilt University, Nashville, Tennessee 37232 (United States); Dicker, Adam P.; Yu, Yan [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Fenster, Aaron [Department of Imaging Research, Robarts Research Institute, London, Ontario N6A 5K8 (Canada); Fichtinger, Gabor [School of Computer Science, Queen’s University, Kingston, Ontario K7L 3N6 (Canada); Meltsner, Michael A. [Philips Radiation Oncology Systems, Fitchburg, Wisconsin 53711 (United States); Moerland, Marinus A. [Department of Radiotherapy, University Medical Center Utrecht, Utrecht, 3508 GA (Netherlands); Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Salcudean, Tim [Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Song, Danny Y. [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Thomadsen, Bruce R. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-10-15

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  7. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: report of Task Group 192.

    Science.gov (United States)

    Podder, Tarun K; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A; Crass, Jostin B; Dicker, Adam P; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A; Moerland, Marinus A; Nath, Ravinder; Rivard, Mark J; Salcudean, Tim; Song, Danny Y; Thomadsen, Bruce R; Yu, Yan

    2014-10-01

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy & Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3-6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests should

  8. Superheated-drop (bubble) neutron detectors and their compliance with ICRP-60

    Energy Technology Data Exchange (ETDEWEB)

    d' Errico, F. (Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari Istituto Nazionale di Fisica Nucleare, Pisa (Italy)); Alberts, W.G. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany))

    1994-01-01

    Several devices based on superheated-drop detector technology have become available almost simultaneously with the release of new ICRP and ICRU publications. Given this circumstance, a study of the characteristics of the system has been undertaken by the authors considering the revised recommendations for neutron dosimetry. The dose equivalent response in free air has been examined experimentally as a function of energy from thermal up to 70 MeV neutrons, and its dependence on the angle of incidence has been tested on a phantom at 0.57 MeV. Some results are discussed with respect to lower limit of detection, temperature sensitivity, [gamma] discrimination, batch-to-batch uniformity, and reproducibility. Some conclusions in terms of advantages, limitations and possible applications of the system are presented. (author).

  9. Status Report on Activities of the Systems Assessment Task Force, OECD-NEA Expert Group on Accident Tolerant Fuels for LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, Shannon Michelle [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    The Organization for Economic Cooperation and Development /Nuclear Energy Agency (OECD/NEA) Nuclear Science Committee approved the formation of an Expert Group on Accident Tolerant Fuel (ATF) for LWRs (EGATFL) in 2014. Chaired by Kemal Pasamehmetoglu, INL Associate Laboratory Director for Nuclear Science and Technology, the mandate for the EGATFL defines work under three task forces: (1) Systems Assessment, (2) Cladding and Core Materials, and (3) Fuel Concepts. Scope for the Systems Assessment task force (TF1) includes definition of evaluation metrics for ATF, technology readiness level definition, definition of illustrative scenarios for ATF evaluation, and identification of fuel performance and system codes applicable to ATF evaluation. The Cladding and Core Materials (TF2) and Fuel Concepts (TF3) task forces will identify gaps and needs for modeling and experimental demonstration; define key properties of interest; identify the data necessary to perform concept evaluation under normal conditions and illustrative scenarios; identify available infrastructure (internationally) to support experimental needs; and make recommendations on priorities. Where possible, considering proprietary and other export restrictions (e.g., International Traffic in Arms Regulations), the Expert Group will facilitate the sharing of data and lessons learned across the international group membership. The Systems Assessment task force is chaired by Shannon Bragg-Sitton (Idaho National Laboratory [INL], U.S.), the Cladding Task Force is chaired by Marie Moatti (Electricite de France [EdF], France), and the Fuels Task Force is chaired by a Masaki Kurata (Japan Atomic Energy Agency [JAEA], Japan). The original Expert Group mandate was established for June 2014 to June 2016. In April 2016 the Expert Group voted to extend the mandate one additional year to June 2017 in order to complete the task force deliverables; this request was subsequently approved by the Nuclear Science Committee. This

  10. Modification of male adult simulator posture of ICRP 110 reference; Modificacao da postura do simulador adulto masculino (AM) de referencia da ICRP 110

    Energy Technology Data Exchange (ETDEWEB)

    Galeano, Diego C.; Souza, Divanizia N.; Santos, Willian S.; Carvalho Junior, Alberico B., E-mail: galeano88@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica

    2014-07-01

    Voxel simulators are usually constructed based on computed tomography and magnetic resonance, so the supine position (lying) is the most used. This may result in a overestimated or underestimated the radiation dose, depending on the exposure scenario adopted. Thus, the objective was to change the attitude of the male adult simulator reference ICRP 110, AM (Adult Male), to a sitting posture. For change of posture were possible, it was necessary increasing the number of slices that comprise AM simulator by reducing the height of the voxel of 8.0 mm to 2.0 mm, thus making each voxel approximately cubic. A subroutine was created in Visual Monte Carlo software (VMC) to rotate the thigh region of the simulator and position it between the region of the leg and trunk. The ScionImage software was used to rebuild and soften the contours of the knee and hip of the simulator in a sitting posture, and 3D visualization of the simulator was used VolView software. The AM simulator in the seated position has the same anatomical features of the simulator in the standing posture. Using the MCNPX code [ref] was carried out the conversion coefficients for calculating the AP irradiation geometry (anteroposterior) comparing the AM simulator standing and sitting in order to evaluate the difference scattering and absorption of radiation by the two simulators. The result shows a difference up to 100% in the fluency conversion coefficients in nearby organs located in the pelvic region and in organs with distribution in the whole body (such as skin, muscle, lymph nodes and skeletal)

  11. Three-dimensional, task-specific robot therapy of the arm after stroke: a multicentre, parallel-group randomised trial.

    Science.gov (United States)

    Klamroth-Marganska, Verena; Blanco, Javier; Campen, Katrin; Curt, Armin; Dietz, Volker; Ettlin, Thierry; Felder, Morena; Fellinghauer, Bernd; Guidali, Marco; Kollmar, Anja; Luft, Andreas; Nef, Tobias; Schuster-Amft, Corina; Stahel, Werner; Riener, Robert

    2014-02-01

    Arm hemiparesis secondary to stroke is common and disabling. We aimed to assess whether robotic training of an affected arm with ARMin--an exoskeleton robot that allows task-specific training in three dimensions-reduces motor impairment more effectively than does conventional therapy. In a prospective, multicentre, parallel-group randomised trial, we enrolled patients who had had motor impairment for more than 6 months and moderate-to-severe arm paresis after a cerebrovascular accident who met our eligibility criteria from four centres in Switzerland. Eligible patients were randomly assigned (1:1) to receive robotic or conventional therapy using a centre-stratified randomisation procedure. For both groups, therapy was given for at least 45 min three times a week for 8 weeks (total 24 sessions). The primary outcome was change in score on the arm (upper extremity) section of the Fugl-Meyer assessment (FMA-UE). Assessors tested patients immediately before therapy, after 4 weeks of therapy, at the end of therapy, and 16 weeks and 34 weeks after start of therapy. Assessors were masked to treatment allocation, but patients, therapists, and data analysts were unmasked. Analyses were by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT00719433. Between May 4, 2009, and Sept 3, 2012, 143 individuals were tested for eligibility, of whom 77 were eligible and agreed to participate. 38 patients assigned to robotic therapy and 35 assigned to conventional therapy were included in analyses. Patients assigned to robotic therapy had significantly greater improvements in motor function in the affected arm over the course of the study as measured by FMA-UE than did those assigned to conventional therapy (F=4.1, p=0.041; mean difference in score 0.78 points, 95% CI 0.03-1.53). No serious adverse events related to the study occurred. Neurorehabilitation therapy including task-oriented training with an exoskeleton robot can enhance improvement of

  12. Commissioning specialist diabetes services for adults with diabetes: summary of a Diabetes UK Task and Finish group report.

    Science.gov (United States)

    Goenka, N; Turner, B; Vora, J

    2011-12-01

    The increasing prevalence of diabetes, the drive to develop community services for diabetes and the Quality and Outcomes Framework for diabetes have led to improvements in the management of diabetes in primary care settings, with services traditionally provided only in specialist care now provided for many patients with diabetes by non-specialists. Consequently, there is a need to redefine roles, responsibilities and components of a specialist diabetes service to provide for the needs of patients in the National Health Service (NHS) today. The delivery of diabetes care is complex and touches on almost every aspect of the health service. It is the responsibility of those working within commissioning and specialist provider roles to work together with people with diabetes to develop, organize and deliver a full range of integrated diabetes care services. The local delivery model agreed within the local diabetes network, comprising specialist teams, primary care teams, commissioners and people with diabetes, should determine how the diabetes specialist services are organizsed. It should identify the roles and responsibilities of provider organizations to ensure that the right person provides the right care, at the right time, and in the right place. We summarize a report entitled 'Commissioning Diabetes Specialist Services for Adults with Diabetes', which has been produced, as a 'Task and Finish' group activity within Diabetes UK, to assist managers, commissioners and healthcare professionals to provide advice on the structure, roles and components of specialist diabetes services for adults. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

  13. Reexamining the validity and reliability of the clinical version of the Iowa gambling task: Evidence from a normal subject group

    Directory of Open Access Journals (Sweden)

    Ching-Hung eLin

    2013-05-01

    Full Text Available Over past decade, the Iowa gambling task (IGT has been utilized to test various decision deficits induced by neurological damage or psychiatric disorders. The IGT has recently been standardized for identifying 13 different neuropsychological disorders. Neuropsychological patients choose bad decks frequently, and normal subjects prefer good EV decks. However, the IGT has several validity and reliability problems. Some research groups have pointed out that the validity of IGT is influenced by the personality and emotional state of subjects. Additionally, several other studies have proposed that the prominent deck B phenomenon (PDB phenomenon – that is, normal subjects preferring bad deck B – may be the most serious problem confronting IGT validity. Specifically, deck B offers a high frequency of gains but negative EV. In the standard IGT administration, choice behavior can be understood with reference to gain-loss frequency (GLF rather than inferred future consequences (EV, the basic assumption of IGT. Furthermore, using two different criteria (basic assumption vs. professional norm results in significantly different classification results. Therefore, we recruited 72 normal subjects to test the validity and reliability of IGT. Each subject performed three runs of the computer-based clinical IGT version. The PDB phenomenon has been observed to a significant degree in the first and second stages of the clinical IGT version. Obviously, validity, reliability and the practice effect were unstable between two given stages. The present form of the clinical IGT version has only one stage, so its use should be reconsidered for examining normal decision makers; results from patient groups must also be interpreted with great care. GLF could be the main factor to be considered in establishing the constructional validity and reliability of the clinical IGT version.

  14. Monte Carlo reference data sets for imaging research: Executive summary of the report of AAPM Research Committee Task Group 195.

    Science.gov (United States)

    Sechopoulos, Ioannis; Ali, Elsayed S M; Badal, Andreu; Badano, Aldo; Boone, John M; Kyprianou, Iacovos S; Mainegra-Hing, Ernesto; McMillan, Kyle L; McNitt-Gray, Michael F; Rogers, D W O; Samei, Ehsan; Turner, Adam C

    2015-10-01

    The use of Monte Carlo simulations in diagnostic medical imaging research is widespread due to its flexibility and ability to estimate quantities that are challenging to measure empirically. However, any new Monte Carlo simulation code needs to be validated before it can be used reliably. The type and degree of validation required depends on the goals of the research project, but, typically, such validation involves either comparison of simulation results to physical measurements or to previously published results obtained with established Monte Carlo codes. The former is complicated due to nuances of experimental conditions and uncertainty, while the latter is challenging due to typical graphical presentation and lack of simulation details in previous publications. In addition, entering the field of Monte Carlo simulations in general involves a steep learning curve. It is not a simple task to learn how to program and interpret a Monte Carlo simulation, even when using one of the publicly available code packages. This Task Group report provides a common reference for benchmarking Monte Carlo simulations across a range of Monte Carlo codes and simulation scenarios. In the report, all simulation conditions are provided for six different Monte Carlo simulation cases that involve common x-ray based imaging research areas. The results obtained for the six cases using four publicly available Monte Carlo software packages are included in tabular form. In addition to a full description of all simulation conditions and results, a discussion and comparison of results among the Monte Carlo packages and the lessons learned during the compilation of these results are included. This abridged version of the report includes only an introductory description of the six cases and a brief example of the results of one of the cases. This work provides an investigator the necessary information to benchmark his/her Monte Carlo simulation software against the reference cases included here

  15. Automated recording of individual performance and hand preference during joystick-task acquisition in group-living bonnet macaques (Macaca radiata).

    Science.gov (United States)

    Andrews, M W; Rosenblum, L A

    1994-12-01

    A microchip that provided a unique identification number was injected into each forearm of all 8 members of a bonnet macaque (Macaca radiata) social group. The group was then given computer-controlled joystick tasks of increasing difficulty. The identification number of the arm used on each trial was input into the computer and used to determine individual performance and hand preference in more than 23,000 trials. Three subjects reversed hand preference as task difficulty was increased over time. All subjects exhibited nearly exclusive use of a single hand on the most difficult task; 6 used the right hand, and 2 used the left. Daily patterns of joystick activity for the group members differed somewhat from that of our individually housed monkeys.

  16. A group-based tasks allocation algorithm for the optimization of long leave opportunities in academic departments

    Science.gov (United States)

    Eyono Obono, S. D.; Basak, Sujit Kumar

    2011-12-01

    The general formulation of the assignment problem consists in the optimal allocation of a given set of tasks to a workforce. This problem is covered by existing literature for different domains such as distributed databases, distributed systems, transportation, packets radio networks, IT outsourcing, and teaching allocation. This paper presents a new version of the assignment problem for the allocation of academic tasks to staff members in departments with long leave opportunities. It presents the description of a workload allocation scheme and its algorithm, for the allocation of an equitable number of tasks in academic departments where long leaves are necessary.

  17. Age and gender diversity as determinants of performance and health in a public organization: the role of task complexity and group size.

    Science.gov (United States)

    Wegge, Jürgen; Roth, Carla; Neubach, Barbara; Schmidt, Klaus-Helmut; Kanfer, Ruth

    2008-11-01

    The influence of age and gender composition on group performance and self-reported health disorders was examined with data from 4,538 federal tax employees working in 222 natural work unit groups. As hypothesized, age diversity correlated positively with performance only in groups solving complex decision-making tasks, and this finding was replicated when analyzing performance data collected 1 year later. Age diversity was also positively correlated with health disorders--but only in groups working on routine decision-making tasks. Gender composition also had a significant effect on group performance, such that groups with a high proportion of female employees performed worse and reported more health disorders than did gender-diverse teams. As expected, effects of gender composition were most pronounced in large groups. Effects of age diversity were found when controlling for gender diversity and vice versa. Thus, age and gender diversity seem to play a unique role in performance and well-being. The moderating role of task complexity for both effects of age diversity and the moderating role of group size for both effects of gender diversity further suggest that the impact of these 2 variables depends on different group processes (e.g., knowledge exchange, variation in gender salience).

  18. Clinical implementation of an electron monitor unit dosimetry system based on task group 71 report and a commercial calculation program

    Directory of Open Access Journals (Sweden)

    Huijun Xu

    2016-01-01

    Full Text Available Many clinics still use monitor unit (MU calculations for electron treatment planning and/or quality assurance (QA. This work (1 investigates the clinical implementation of a dosimetry system including a modified American Association of Physicists in Medicine-task group-71 (TG-71-based electron MU calculation protocol (modified TG-71 electron [mTG-71E] and an independent commercial calculation program and (2 provides the practice recommendations for clinical usage. Following the recently published TG-71 guidance, an organized mTG-71E databook was developed to facilitate data access and subsequent MU computation according to our clinical need. A recently released commercial secondary calculation program - Mobius3D (version 1.5.1 Electron Quick Calc (EQC (Mobius Medical System, LP, Houston, TX, USA, with inherent pencil beam algorithm and independent beam data, was used to corroborate the calculation results. For various setups, the calculation consistency and accuracy of mTG-71E and EQC were validated by their cross-comparison and the ion chamber measurements in a solid water phantom. Our results show good agreement between mTG-71E and EQC calculations, with average 2% difference. Both mTG-71E and EQC calculations match with measurements within 3%. In general, these differences increase with decreased cutout size, increased extended source to surface distance, and lower energy. It is feasible to use TG71 and Mobius3D clinically as primary and secondary electron MU calculations or vice versa. We recommend a practice that only requires patient-specific measurements in rare cases when mTG-71E and EQC calculations differ by 5% or more.

  19. Dosimetric evaluation of a commercial 3D treatment planning system using the AAPM Task Group 23 test package.

    Science.gov (United States)

    Casanova Borca, Valeria; Pasquino, Massimo; Bresciani, Sara; Catuzzo, Paola; Ozzello, Franca; Tofani, Santi

    2005-03-01

    The accuracy of the dose calculation algorithm is one of the most critical steps in assessing the radiotherapy treatment to achieve the 5% accuracy in dose delivery, which represents the suggested limit to increase the complication-free local control of tumor. We have used the AAPM Task Group 23 (TG-23) test package for clinical photon external beam therapy to evaluate the accuracy of the new version of the PLATO TPS algorithm. The comparison between tabulated values and calculated ones has been performed for 266 and 297 dose values for the 4 and 18 MV photon beams, respectively. Dose deviations less than 2% were found in the 98.5%- and 90.6% analyzed dose points for the two considered energies, respectively. Larger deviations were obtained for both energies, in large dose gradients, such as the build-up region or near the field edges and blocks. As far as the radiological field width is concerned, 64 points were analyzed for both the energies: 53 points (83%) and 64 points (100%) were within +/-2 millimeters for the 4 and 18 MV photon beams, respectively. The results show the good accuracy of the algorithm either in simple geometry beam conditions or in complex ones, in homogeneous medium, and in the presence of inhomogeneities, for low and high energy beams. Our results fit well the data reported by several authors related to the calculation accuracy of different treatment planning systems (TPSs) (within a mean value of 0.7% and 1.2% for 4 and 18 MV respectively). The TG-23 test package can be considered a powerful instrument to evaluate dose calculation accuracy, and as such may play an important role in a quality assurance program related to the commissioning of a new TPS.

  20. Verification of monitor unit calculations for non-IMRT clinical radiotherapy: report of AAPM Task Group 114.

    Science.gov (United States)

    Stern, Robin L; Heaton, Robert; Fraser, Martin W; Goddu, S Murty; Kirby, Thomas H; Lam, Kwok Leung; Molineu, Andrea; Zhu, Timothy C

    2011-01-01

    The requirement of an independent verification of the monitor units (MU) or time calculated to deliver the prescribed dose to a patient has been a mainstay of radiation oncology quality assurance. The need for and value of such a verification was obvious when calculations were performed by hand using look-up tables, and the verification was achieved by a second person independently repeating the calculation. However, in a modern clinic using CT/MR/PET simulation, computerized 3D treatment planning, heterogeneity corrections, and complex calculation algorithms such as convolution/superposition and Monte Carlo, the purpose of and methodology for the MU verification have come into question. In addition, since the verification is often performed using a simpler geometrical model and calculation algorithm than the primary calculation, exact or almost exact agreement between the two can no longer be expected. Guidelines are needed to help the physicist set clinically reasonable action levels for agreement. This report addresses the following charges of the task group: (1) To re-evaluate the purpose and methods of the "independent second check" for monitor unit calculations for non-IMRT radiation treatment in light of the complexities of modern-day treatment planning. (2) To present recommendations on how to perform verification of monitor unit calculations in a modern clinic. (3) To provide recommendations on establishing action levels for agreement between primary calculations and verification, and to provide guidance in addressing discrepancies outside the action levels. These recommendations are to be used as guidelines only and shall not be interpreted as requirements.

  1. Development of the approaches to the classification and groups of the tasks fulfilling by the internal auditors

    OpenAIRE

    Шалімова, Наталія Станіславівна; Андрощук, Ірина Іванівна

    2015-01-01

    The aim of the article is critical rethinking and revision of types of tasks that can be performed within internal audit, given the development of internationally recognized professional organizations in this area, including the Institute of Internal Auditors.It is proved a necessity of classification of tasks performed within internal audit based on international standards of professional practice of internal auditing, developed by the Institute of Internal Auditors, using requirements of In...

  2. Status Report on Activities of the Systems Assessment Task Force, OECD-NEA Expert Group on Accident Tolerant Fuels for LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, Shannon Michelle [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The Organization for Economic Cooperation and Development /Nuclear Energy Agency (OECD/NEA) Nuclear Science Committee approved the formation of an Expert Group on Accident Tolerant Fuel (ATF) for LWRs (EGATFL) in 2014. Chaired by Kemal Pasamehmetoglu, INL Associate Laboratory Director for Nuclear Science and Technology, the mandate for the EGATFL defines work under three task forces: (1) Systems Assessment, (2) Cladding and Core Materials, and (3) Fuel Concepts. Scope for the Systems Assessment task force includes definition of evaluation metrics for ATF, technology readiness level definition, definition of illustrative scenarios for ATF evaluation, parametric studies, and selection of system codes. The Cladding and Core Materials and Fuel Concepts task forces will identify gaps and needs for modeling and experimental demonstration; define key properties of interest; identify the data necessary to perform concept evaluation under normal conditions and illustrative scenarios; identify available infrastructure (internationally) to support experimental needs; and make recommendations on priorities. Where possible, considering proprietary and other export restrictions (e.g., International Traffic in Arms Regulations), the Expert Group will facilitate the sharing of data and lessons learned across the international group membership. The Systems Assessment Task Force is chaired by Shannon Bragg-Sitton (INL), while the Cladding Task Force will be chaired by a representative from France (Marie Moatti, Electricite de France [EdF]) and the Fuels Task Force will be chaired by a representative from Japan (Masaki Kurata, Japan Atomic Energy Agency [JAEA]). This report provides an overview of the Systems Assessment Task Force charter and status of work accomplishment.

  3. ICRP118关于辐射诱导组织反应内容的部分修改建议%Revision recommendations of tissue reaction induced by radiation in ICRP118

    Institute of Scientific and Technical Information of China (English)

    刘强; 王彦

    2013-01-01

    国际辐射防护委员会(ICRP)自2007年以来发布了一系列放射防护出版物的修订建议,以替代之前的版本.ICRP在2012年发布的118号建议书中,非常重视辐射的非致癌因素对健康的损害,并将之前的“确定性效应”更倾向于称之为“组织反应”.该建议书主要关注了正常组织的辐射效应和各个器官的剂量阈值.%International Commission on Radiological Protection(ICRP)issued new recommendations on radiological protection in 2012 which formally replaced the previous recommendations.In the new recommendation 118,which issued in 2012,ICRP included consideration of the detriment arising from non-cancer effects of radiation on health.These effects,previously called deterministic effects,are now referred to as tissue reactions.The commission considered the effects of radiation in normal tissues and organs-threshold doses for tissue reactions in a radiation protection context.

  4. Dose coefficients for radionuclides produced in high energy proton accelerator facilities. Coefficients for radionuclides not listed in ICRP publications

    CERN Document Server

    Kawai, K; Noguchi, H

    2002-01-01

    Effective dose coefficients, the committed effective dose per unit intake, by inhalation and ingestion have been calculated for 304 nuclides, including (1) 230 nuclides with half-lives >= 10 min and their daughters that are not listed in ICRP Publications and (2) 74 nuclides with half-lives < 10 min that are produced in a spallation target. Effective dose coefficients for inhalation of soluble or reactive gases have been calculated for 21 nuclides, and effective dose rates for inert gases have been calculated for 9 nuclides. Dose calculation was carried out using a general-purpose nuclear decay database DECDC developed at JAERI and a decay data library newly compiled from the ENSDF for the nuclides abundantly produced in a spallation target. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The effective dose rates were calculated by considering both external irradiation from the surrounding cloud and irradiation of the lun...

  5. Inclusion of thin target and source regions in alimentary and respiratory tract systems of mesh-type ICRP adult reference phantoms

    Science.gov (United States)

    Kim, Han Sung; Yeom, Yeon Soo; Tat Nguyen, Thang; Choi, Chansoo; Han, Min Cheol; Lee, Jai Ki; Kim, Chan Hyeong; Zankl, Maria; Petoussi-Henss, Nina; Bolch, Wesley E.; Lee, Choonsik; Qiu, Rui; Eckerman, Keith; Chung, Beom Sun

    2017-03-01

    It is not feasible to define very small or complex organs and tissues in the current voxel-type adult reference computational phantoms of the International Commission on Radiological Protection (ICRP), which limit dose coefficients for weakly penetrating radiations. To address the problem, the ICRP is converting the voxel-type reference phantoms into mesh-type phantoms. In the present study, as a part of the conversion project, the micrometer-thick target and source regions in the alimentary and respiratory tract systems as described in ICRP Publications 100 and 66 were included in the mesh-type ICRP reference adult male and female phantoms. In addition, realistic lung airway models were simulated to represent the bronchial (BB) and bronchiolar (bb) regions. The electron specific absorbed fraction (SAF) values for the alimentary and respiratory tract systems were then calculated and compared with the values calculated with the stylized models of ICRP Publications 100 and 66. The comparisons show generally good agreement for the oral cavity, oesophagus, and BB, whereas for the stomach, small intestine, large intestine, extrathoracic region, and bb, there are some differences (e.g. up to ~9 times in the large intestine). The difference is mainly due to anatomical difference in these organs between the realistic mesh-type phantoms and the simplified stylized models. The new alimentary and respiratory tract models in the mesh-type ICRP reference phantoms preserve the topology and dimensions of the voxel-type ICRP phantoms and provide more reliable SAF values than the simplified models adopted in previous ICRP Publications.

  6. Collaboration or Confrontation? An Investigation into the Role of Prior Experiences in the Completion of Collaborative Group Tasks by Student Teachers

    Science.gov (United States)

    Crichton, Hazel; Templeton, Brian

    2013-01-01

    This paper describes research which investigated how a group of 23 postgraduate student teachers from a wide variety of international backgrounds with a broad range of previous experience perceived the significance of their own and others' prior experience in accomplishing directed collaborative tasks, related to their coursework, in…

  7. Survey of the ICRP 103 detriment-model; Untersuchung und Bewertung des Detrimentbegriffs im Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Emami, S.; Buermeyer, J.; Spruck, K.; Breckow, J. [Technische Hochschule Mittelhessen (THM), Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2016-07-01

    The detriment of ICRP 103 is roughly defined as the product of the (organ specific) risk coefficient and the ''damage'' that may be associated with a (organ specific) cancer or hereditary effect, respectively. This is to indicate a weighted risk according to the radiation sensitivity of the different organs and the severity of damage that may possibly arise. Whereas the risk coefficients refer to radiation exposure parameters, the scale or degree of damage is independent of these parameters. The radiation independent parameters are the lethality, the loss of quality of life and the reduced life expectancy, which are considered as quantities associated with the severity of disease or damage, respectively. These parameters may change gradually, on the one hand possibly due to an increase of cancer becoming a common disease within the population. On the other hand, possibly to a decrease of cancer due to the progress in medical diagnostics and treatments that allow patients to survive or at least maintain a higher life quality standard. The damage and therefore the detriment appears to be mostly affected by the lethality. The lethality is the quotient of mortality to incidence. The investigation of the detriment presented in this paper focuses on the influence of the lethality on the detriment from 1980-2012 in Germany and USA.

  8. ICRP publication 82 on protection against prolonged exposure - application in accident situations

    Energy Technology Data Exchange (ETDEWEB)

    Hedemann Jensen, P. [Risoe National Laboratory, Roskilde (Denmark)

    2003-06-01

    In the past 15 years, two events have occurred that cover a conceivable range of emergencies involving extensive post-emergency phase response, namely the Chernobyl and Goiania accidents. Large amounts of {sup 137}Cs were released to the environment during these accidents, leading to a prolonged or quasi-prolonged exposure of the affected populations. The experience gained from these accidents and others have revealed that there is a need for an updated and fully integrated system of guidance on implementation of countermeasures. A revised system must have a sound technical basis but must also be understandable, explainable and acceptable to the public and the decisionmakers. Once all protective actions have been undertaken, the situation should be considered 'normal' again with no further restriction being imposed. Therefore a common language explanation should be developed for the public and public officials that clearly state the risks of radiation exposure and what actions are appropriate and inappropriate, and what is 'safe'. The concepts of 'safe' and 'return to normality' should be developed together with intervention criteria, disengaged from the linear non-threshold risk hypothesis. Within this context, the application of the recommendations in ICRP Publication 82 for application in post-accident situations is briefly summarized with reference to observations and lessons learned from the Chernobyl and Goiania accidents. (orig.)

  9. Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem.

    Science.gov (United States)

    Guillén, J; Beresford, N A; Baeza, A; Izquierdo, M; Wood, M D; Salas, A; Muñoz-Serrano, A; Corrales-Vázquez, J M; Muñoz-Muñoz, J G

    2017-09-14

    A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CRwo, were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CRwo values estimated from these data are compared to those reported in international compilations and databases. Copyright © 2017. Published by Elsevier Ltd.

  10. Examining the Impact of Novel Pre-Activity Tasks on Macroskills: The Case of Group Discussion on Writing Ability

    Science.gov (United States)

    Khoshsima, Hooshang; Zare-Behtash, Esmail; Khosravani, Mahboobeh

    2016-01-01

    The main concern of most researchers in the field of second and foreign language teaching is lessening the problems and eliminating the hinders on the way of learning a language. Writing is considered as one of the most challenging and complicated tasks for learners to perform particularly when they have to write in a second or foreign language.…

  11. Classification and evaluation strategies of auto-segmentation approaches for PET: Report of AAPM task group No. 211.

    Science.gov (United States)

    Hatt, Mathieu; Lee, John A; Schmidtlein, Charles R; Naqa, Issam El; Caldwell, Curtis; De Bernardi, Elisabetta; Lu, Wei; Das, Shiva; Geets, Xavier; Gregoire, Vincent; Jeraj, Robert; MacManus, Michael P; Mawlawi, Osama R; Nestle, Ursula; Pugachev, Andrei B; Schöder, Heiko; Shepherd, Tony; Spezi, Emiliano; Visvikis, Dimitris; Zaidi, Habib; Kirov, Assen S

    2017-06-01

    on advanced image analysis paradigms provide generally more accurate segmentation than approaches based on PET activity thresholds, particularly for realistic configurations. However, this may not be the case for simple shape lesions in situations with a narrower range of parameters, where simpler methods may also perform well. Recent algorithms which employ some type of consensus or automatic selection between several PET-AS methods have potential to overcome the limitations of the individual methods when appropriately trained. In either case, accuracy evaluation is required for each different PET scanner and scanning and image reconstruction protocol. For the simpler, less robust approaches, adaptation to scanning conditions, tumor type, and tumor location by optimization of parameters is necessary. The results from the method evaluation stage can be used to estimate the contouring uncertainty. All PET-AS contours should be critically verified by a physician. A standard test, i.e., a benchmark dedicated to evaluating both existing and future PET-AS algorithms needs to be designed, to aid clinicians in evaluating and selecting PET-AS algorithms and to establish performance limits for their acceptance for clinical use. The initial steps toward designing and building such a standard are undertaken by the task group members. © 2017 American Association of Physicists in Medicine.

  12. Generic Screening Models for Assessing Exposures to the Public and ICRP Reference Animals and Plants

    Energy Technology Data Exchange (ETDEWEB)

    Yankovich, Tamara L.; Proehl, Gerhard; Telleria, Diego [International Atomic Energy Agency, P.O. Box 100, 1400 Vienna (Austria); Berkovskyy, Volodymyr [Ukrainian Radiation Protection Institute (RPI), 53, Melnikova Street, 04050, Kiev (Ukraine)

    2014-07-01

    Exposure', and 'Generic Models for Use in Assessing the Impact of Radioactive Discharges', respectively. Volume 3 is currently being drafted and will provide coefficients that enable screening assessments for the ICRP Reference Animals and Plants (RAPs), based on the models presented in ICRP publications 108 and 114. Through the application of the same models for dispersion of radionuclides in the atmosphere and in water bodies, standardized input parameters, assumptions and approaches that are being applied to develop screening coefficients, an integrated approach is being established that can be used to estimate exposures to people and the environment and to demonstrate protection, in accordance with SF-1. This integrated approach will allow the establishment of relationships of exposures to people, and to flora and fauna for the same levels of environmental radioactivity. This paper provides an update of the current status of the SRS 19 update. (authors)

  13. Radiological Protection in Cone Beam Computed Tomography (CBCT). ICRP Publication 129.

    Science.gov (United States)

    Rehani, M M; Gupta, R; Bartling, S; Sharp, G C; Pauwels, R; Berris, T; Boone, J M

    2015-07-01

    The objective of this publication is to provide guidance on radiological protection in the new technology of cone beam computed tomography (CBCT). Publications 87 and 102 dealt with patient dose management in computed tomography (CT) and multi-detector CT. The new applications of CBCT and the associated radiological protection issues are substantially different from those of conventional CT. The perception that CBCT involves lower doses was only true in initial applications. CBCT is now used widely by specialists who have little or no training in radiological protection. This publication provides recommendations on radiation dose management directed at different stakeholders, and covers principles of radiological protection, training, and quality assurance aspects. Advice on appropriate use of CBCT needs to be made widely available. Advice on optimisation of protection when using CBCT equipment needs to be strengthened, particularly with respect to the use of newer features of the equipment. Manufacturers should standardise radiation dose displays on CBCT equipment to assist users in optimisation of protection and comparisons of performance. Additional challenges to radiological protection are introduced when CBCT-capable equipment is used for both fluoroscopy and tomography during the same procedure. Standardised methods need to be established for tracking and reporting of patient radiation doses from these procedures. The recommendations provided in this publication may evolve in the future as CBCT equipment and applications evolve. As with previous ICRP publications, the Commission hopes that imaging professionals, medical physicists, and manufacturers will use the guidelines and recommendations provided in this publication for implementation of the Commission's principle of optimisation of protection of patients and medical workers, with the objective of keeping exposures as low as reasonably achievable, taking into account economic and societal factors, and

  14. Resting-state BOLD networks versus task-associated functional MRI for distinguishing Alzheimer's disease risk groups.

    Science.gov (United States)

    Fleisher, Adam S; Sherzai, Ayesha; Taylor, Curtis; Langbaum, Jessica B S; Chen, Kewei; Buxton, Richard B

    2009-10-01

    To assess the ability of resting-state functional magnetic resonance imaging to distinguish known risk factors for AD, we evaluated 17 cognitively normal individuals with a family history of AD and at least one copy of the apolipoprotein e4 allele compared to 12 individuals who were not carriers of the APOE4 gene and did not have a family history of AD. Blood oxygen level dependent fMRI was performed evaluating encoding-associated signal and resting-state default mode network signal differences between the two risk groups. Neurocognitive testing revealed that the high risk group performed worse on category fluency testing, but the groups were equivalent on all other cognitive measures. During encoding of novel face-name pairs, there were no regions of encoding-associated BOLD activations that were different in the high risk group. Encoding-associated deactivations were greater in magnitude in the low risk group in the medial and right lateral parietal cortex, similar to findings in AD studies. The resting-state DMN analysis demonstrated nine regions in the prefrontal, orbital frontal, temporal and parietal lobes that distinguished the two risk groups. Resting-state DMN analysis could distinguish risk groups with an effect size of 3.35, compared to an effect size of 1.39 using encoding-associated fMRI techniques. Imaging of the resting state avoids performance related variability seen in activation fMRI, is less complicated to acquire and standardize, does not require radio-isotopes, and may be more effective at identifying functional pathology associated with AD risk compared to non-resting fMRI techniques.

  15. Dose calculation formalisms and consensus dosimetry parameters for intravascular brachytherapy dosimetry: recommendations of the AAPM Therapy Physics Committee Task Group No. 149.

    Science.gov (United States)

    Chiu-Tsao, Sou-Tung; Schaart, Dennis R; Soares, Christopher G; Nath, Ravinder

    2007-11-01

    Since the publication of AAPM Task Group 60 report in 1999, a considerable amount of dosimetry data for the three coronary brachytherapy systems in use in the United States has been reported. A subgroup, Task Group 149, of the AAPM working group on Special Brachytherapy Modalities (Bruce Thomadsen, Chair) was charged to develop recommendations for dose calculation formalisms and the related consensus dosimetry parameters. The recommendations of this group are presented here. For the Cordis 192Ir and Novoste 90Sr/90Y systems, the original TG-43 formalism in spherical coordinates should be used along with the consensus values of the dose rate constant, geometry function, radial dose function, and anisotropy function for the single seeds. Contributions from the single seeds should be added linearly for the calculation of dose distributions from a source train. For the Guidant 32P wire system, the modified TG-43 formalism in cylindrical coordinates along with the recommended data for the 20 and 27 mm wires should be used. Data tables for the 6, 10, 14, 18, and 22 seed trains of the Cordis system, 30, 40, and 60 mm seed trains of the Novoste system, and the 20 and 27 mm wires of the Guidant system are presented along with our rationale and methodology for selecting the consensus data. Briefly, all available datasets were compared with each other and the consensus dataset was either an average of available data or the one obtained from the most densely populated study; in most cases this was a Monte Carlo calculation.

  16. A metaanalysis of perceptual organization in schizophrenia, schizotypy, and other high-risk groups based on variants of the Embedded Figures Task.

    Directory of Open Access Journals (Sweden)

    Kirsten Rebecca Panton

    2016-02-01

    Full Text Available Current research on perceptual organization in schizophrenia frequently employs shapes with regularly sampled contours (fragmented stimuli, in noise fields composed of similar elements, to elicit visual abnormalities. However, perceptual organization is multi-factorial and, in earlier studies, continuous contours have also been employed in tasks assessing the ability to extract shapes from a background. We conducted a systematic review and meta-analysis of studies using closed-contour stimuli, including the Embedded Figures Test (EFT and related tasks, both in people with schizophrenia and in healthy schizotypes and relatives, considered at increased risk for psychosis. Eleven studies met the selection criteria for inclusion in the meta-analysis, including six that used a between-groups study design (i.e. perceptual organization abilities of schizophrenia/high-risk groups were compared to healthy or clinical controls, and five that treated schizophrenia symptoms or schizotypy traits and indices of perceptual organization as continuous variables. Effect sizes and heterogeneity statistics were calculated, and the risk of publication bias was explored. A significant, moderate effect for EFT performance was found with studies that compared performance of schizophrenia/high-risk groups to a healthy or patient comparison group (d = -.523, p<.001. However, significant heterogeneity was also found amongst the schizotypy, but not schizophrenia studies, as well as studies using accuracy, but not reaction time as a measure of performance. A non-significant correlation was found for the studies that examined schizophrenia symptoms or schizotypy traits as continuous variables (r = .012, p = .825. These results suggest that deficits in perceptual organization of non-fragmented stimuli are found when differences between schizophrenia/high-risk groups and comparison groups are maximized. These findings should motivate further investigation of perceptual

  17. Internal dosimetry with the Monte Carlo code GATE: validation using the ICRP/ICRU female reference computational model

    Science.gov (United States)

    Villoing, Daphnée; Marcatili, Sara; Garcia, Marie-Paule; Bardiès, Manuel

    2017-03-01

    The purpose of this work was to validate GATE-based clinical scale absorbed dose calculations in nuclear medicine dosimetry. GATE (version 6.2) and MCNPX (version 2.7.a) were used to derive dosimetric parameters (absorbed fractions, specific absorbed fractions and S-values) for the reference female computational model proposed by the International Commission on Radiological Protection in ICRP report 110. Monoenergetic photons and electrons (from 50 keV to 2 MeV) and four isotopes currently used in nuclear medicine (fluorine-18, lutetium-177, iodine-131 and yttrium-90) were investigated. Absorbed fractions, specific absorbed fractions and S-values were generated with GATE and MCNPX for 12 regions of interest in the ICRP 110 female computational model, thereby leading to 144 source/target pair configurations. Relative differences between GATE and MCNPX obtained in specific configurations (self-irradiation or cross-irradiation) are presented. Relative differences in absorbed fractions, specific absorbed fractions or S-values are below 10%, and in most cases less than 5%. Dosimetric results generated with GATE for the 12 volumes of interest are available as supplemental data. GATE can be safely used for radiopharmaceutical dosimetry at the clinical scale. This makes GATE a viable option for Monte Carlo modelling of both imaging and absorbed dose in nuclear medicine.

  18. Dose coefficients for intakes of radionuclides by workers: Coefficients for radionuclides not listed in ICRP Publication 68

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-12-01

    Dose coefficients, the committed effective dose per unit intake, have been calculated for 149 radionuclides with half-lives {>=} 10 min that are not listed in ICRP Publication 68 (Publ. 68). Effective dose rates for inert gas have been calculated for 2 radionuclides. The dose coefficients were calculated with the computer program LUDEP that calculates internal doses using the respiratory tract model of ICRP Publ. 66 and the biokinetic models of Publ. 30. Nuclear decay data used for the calculation were newly compiled from decay data sets of the Evaluated Nuclear Structure Data File (ENSDF). In the calculation of the effective dose rates, external irradiation from the surrounding cloud and irradiation of the lung from the gas within it were considered. The calculated results are presented in tables, which are the same forms as those in Publ. 68. The range of the differences in the dose coefficients due to the biokinetic models and nuclear decay data employed was also discussed by comparing the dose coefficients between LUDEP and Publ. 68. The dose coefficients and the effective dose rates will be used for dose calculation for radionuclides produced in high-energy proton accelerator and fusion reactor facilities. (author)

  19. Using Different Methods to Access the Difficult Task of Delimiting Species in a Complex Neotropical Hyperdiverse Group

    Science.gov (United States)

    Costa-Silva, Guilherme J.; Rodriguez, Mónica S.; Roxo, Fábio F.; Foresti, Fausto; Oliveira, Claudio

    2015-01-01

    The genus Rineloricaria is a Neotropical freshwater fish group with a long and problematic taxonomic history, attributed to the large number of species and the pronounced similarity among them. In the present work, taxonomic information and different molecular approaches were used to identify species boundaries and characterize independent evolutionary units. We analyzed 228 samples assembled in 53 distinct morphospecies. A general mixed yule-coalescent (GMYC) analysis indicated the existence of 70 entities, while BOLD system analyses showed the existence of 56 distinct BINs. When we used a new proposed integrative taxonomy approach, mixing the results obtained by each analysis, we identified 73 OTUs. We suggest that Rineloricaria probably has some complexity in the known species and several species not formally described yet. Our data suggested that other hyperdiverse fish groups with wide distributions can be further split into many new evolutionary taxonomic units. PMID:26332320

  20. Report on the joint meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, K.L. (ed.)

    1985-10-01

    This report of the Joint Meeting of the Division of Development and Technology Plasma/Wall Interaction and High Heat Flux Materials and Components Task Groups contains contributing papers in the following areas: Plasma/Materials Interaction Program and Technical Assessment, High Heat Flux Materials and Components Program and Technical Assessment, Pumped Limiters, Ignition Devices, Program Planning Activities, Compact High Power Density Reactor Requirements, Steady State Tokamaks, and Tritium Plasma Experiments. All these areas involve the consideration of High Heat Flux on Materials and the Interaction of the Plasma with the First Wall. Many of the Test Facilities are described as well. (LSP)

  1. Does the mask govern the mind?: effects of arbitrary gender representation on quantitative task performance in avatar-represented virtual groups.

    Science.gov (United States)

    Lee, Jong-Eun Roselyn; Nass, Clifford I; Bailenson, Jeremy N

    2014-04-01

    Virtual environments employing avatars for self-representation-including the opportunity to represent or misrepresent social categories-raise interesting and intriguing questions as to how one's avatar-based social category shapes social identity dynamics, particularly when stereotypes prevalent in the offline world apply to the social categories visually represented by avatars. The present experiment investigated how social category representation via avatars (i.e., graphical representations of people in computer-mediated environments) affects stereotype-relevant task performance. In particular, building on and extending the Proteus effect model, we explored whether and how stereotype lift (i.e., a performance boost caused by the awareness of a domain-specific negative stereotype associated with outgroup members) occurred in virtual group settings in which avatar-based gender representation was arbitrary. Female and male participants (N=120) were randomly assigned either a female avatar or a male avatar through a process masked as a random drawing. They were then placed in a numerical minority status with respect to virtual gender-as the only virtual female (male) in a computer-mediated triad with two opposite-gendered avatars-and performed a mental arithmetic task either competitively or cooperatively. The data revealed that participants who were arbitrarily represented by a male avatar and competed against two ostensible female avatars showed strongest performance compared to others on the arithmetic task. This pattern occurred regardless of participants' actual gender, pointing to a virtual stereotype lift effect. Additional mediation tests showed that task motivation partially mediated the effect. Theoretical and practical implications for social identity dynamics in avatar-based virtual environments are discussed.

  2. Quality assurance in radiotherapy: the importance of medical physics staffing levels. Recommendations from an ESTRO/EFOMP joint task group.

    Science.gov (United States)

    Belletti, S; Dutreix, A; Garavaglia, G; Gfirtner, H; Haywood, J; Jessen, K A; Lamm, I L; Mijnheer, B; Noël, A; Nüsslin, F; Rosenow, U; Schneider, P; Seelentag, W; Sheriff, S; Svensson, H; Thwaites, D

    1996-10-01

    The safe application of ionising radiation for diagnosis and therapy requires a high level of knowledge of the underlying processes and of quality assurance. Sophisticated modern equipment can be used effectively for complicated diagnostic and therapeutic techniques only with adequate physics support. In the light of recent analyses and recommendations by national and international societies a joint working group of representatives from ESTRO (European Society for Therapeutic Radiology and Oncology) and from EFOMP (European Federation of Organisations for Medical Physics) was set up to assess the necessary staffing levels for physics support to radiotherapy. The method used to assess the staffing levels, the resulting recommendations and examples of their practical application are described.

  3. Group task-specific circuit training for patients discharged home after stroke may be as effective as individualised physiotherapy in improving mobility.

    Science.gov (United States)

    Dean, Catherine

    2012-01-01

    Does task oriented circuit training improve mobility in patients with stroke compared with individualised physiotherapy? Randomised, controlled trial with concealed allocation and blinded outcome assessment. Nine outpatient rehabilitation centres in the Netherlands. Patients with a stroke who had been discharged home and who could walk 10 m without assistance were included. Cognitive deficits and inability to communicate were key exclusion criteria. Randomisation of 250 participants allocated 126 to task oriented circuit training and 124 to individualised physiotherapy. The task oriented circuit training group trained for 90 min twice-weekly for 12 weeks supervised by physiotherapists and sports trainers as they completed 8 mobility-related stations in groups of 2 to 8 participants. Individualised outpatient physiotherapy was designed to improve balance, physical conditioning, and walking. The primary outcome was the mobility domain of the stroke impact scale measured at 12 weeks and 24 weeks. The domain includes 9 questions about a patient's perceived mobility competence and is scored from 0 to 100 with higher scores indicating better mobility. Secondary outcome measures included other domains of the stroke impact scale, the Nottingham extended ADL scale, the falls efficacy scale, the hospital anxiety and depression scale, comfortable walking speed, 6-minute walk distance, and a stairs test. 242 participants completed the study. There were no differences in the mobility domain of the stroke impact scale between the groups at 12 weeks (mean difference (MD) -0.05 units, 95% CI -1.4 to 1.3 units) or 24 weeks (MD -0.6, 95% CI -1.8 to 0.5). Comfortable walking speed (MD 0.09 m/s, 95% CI 0.04 to 0.13), 6-minute walk distance (MD 20 m, 95% CI 35.3 to 34.7), and stairs test (MD -1.6s, 95% CI -2.9 to -0.3) improved a little more in the circuit training group than the control group at 12 weeks. The memory and thinking domain of the stroke impact scale (MD -1.6 units, 95% CI

  4. The IUGS Task Group on Global Geoscience Professionalism - promoting professional skills professionalism in the teaching, research and application of geoscience for the protection and education of the public

    Science.gov (United States)

    Allington, Ruth; Fernandez-Fuentes, Isabel

    2013-04-01

    A new IUGS Task Group entitled the Task Group on Global Geoscience Professionalism was formed in 2012 and launched at a symposium at the 341GC in Brisbane on strengthening communication between fundamental and applied geosciences and between geoscientists and public. The Task Group aims to ensure that the international geoscience community is engaged in a transformation of its profession so as to embed the need for a professional skills base alongside technical and scientific skills and expertise, within a sound ethical framework in all arenas of geoscience practice. This needs to be established during training and education and reinforced as CPD throughout a career in geoscience as part of ensuring public safety and effective communication of geoscience concepts to the public. The specific objective of the Task Group on Global Geoscience Professionalism that is relevant to this poster session is: • To facilitate a more 'joined up' geoscience community fostering better appreciation by academics and teachers of the professional skills that geoscientists need in the workplace, and facilitate better communication between academic and applied communities leading to more effective application of research findings and technology to applied practitioners and development of research programmes that truly address urgent issues. Other Task Group objectives are: • To provide a specific international forum for discussion of matters of common concern and interest among geoscientists and geoscientific organizations involved in professional affairs, at the local, national and international level; • To act as a resource to IUGS on professional affairs in the geosciences as they may influence and impact "Earth Science for the Global Community" in general - both now and in the future; • To offer and provide leadership and knowledge transfer services to countries and geoscientist communities around the world seeking to introduce systems of professional governance and self

  5. Accuracy and calibration of integrated radiation output indicators in diagnostic radiology: A report of the AAPM Imaging Physics Committee Task Group 190.

    Science.gov (United States)

    Lin, Pei-Jan P; Schueler, Beth A; Balter, Stephen; Strauss, Keith J; Wunderle, Kevin A; LaFrance, M Terry; Kim, Don-Soo; Behrman, Richard H; Shepard, S Jeff; Bercha, Ishtiaq H

    2015-12-01

    Due to the proliferation of disciplines employing fluoroscopy as their primary imaging tool and the prolonged extensive use of fluoroscopy in interventional and cardiovascular angiography procedures, "dose-area-product" (DAP) meters were installed to monitor and record the radiation dose delivered to patients. In some cases, the radiation dose or the output value is calculated, rather than measured, using the pertinent radiological parameters and geometrical information. The AAPM Task Group 190 (TG-190) was established to evaluate the accuracy of the DAP meter in 2008. Since then, the term "DAP-meter" has been revised to air kerma-area product (KAP) meter. The charge of TG 190 (Accuracy and Calibration of Integrated Radiation Output Indicators in Diagnostic Radiology) has also been realigned to investigate the "Accuracy and Calibration of Integrated Radiation Output Indicators" which is reflected in the title of the task group, to include situations where the KAP may be acquired with or without the presence of a physical "meter." To accomplish this goal, validation test protocols were developed to compare the displayed radiation output value to an external measurement. These test protocols were applied to a number of clinical systems to collect information on the accuracy of dose display values in the field.

  6. Accuracy and calibration of integrated radiation output indicators in diagnostic radiology: A report of the AAPM Imaging Physics Committee Task Group 190

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Pei-Jan P., E-mail: Pei-Jan.Lin@vcuhealth.org [Virginia Commonwealth University Medical Center, Richmond, Virginia 23298 (United States); Schueler, Beth A. [Mayo Clinic, Rochester, Minnesota 55905 (United States); Balter, Stephen [Columbia University Medical Center, New York, New York 10032 (United States); Strauss, Keith J. [Children’s Hospital Medical Center, Cincinnati, Ohio 45229 (United States); Wunderle, Kevin A. [Cleveland Clinic Foundation, Cleveland, Ohio 44195 (United States); LaFrance, M. Terry [Baystate Health Systems, Inc., Springfield, Massachusetts 01199 (United States); Kim, Don-Soo [Children’s Hospital Boston, Boston, Massachusetts 02115 (United States); Behrman, Richard H. [Boston University Medical Center, Boston, Massachusetts 02118 (United States); Shepard, S. Jeff [University of Texas MD Anderson Cancer Center, Houston, Texas 77096 (United States); Bercha, Ishtiaq H. [Children’s Hospital Colorado, Aurora, Colorado 80045 (United States)

    2015-12-15

    Due to the proliferation of disciplines employing fluoroscopy as their primary imaging tool and the prolonged extensive use of fluoroscopy in interventional and cardiovascular angiography procedures, “dose-area-product” (DAP) meters were installed to monitor and record the radiation dose delivered to patients. In some cases, the radiation dose or the output value is calculated, rather than measured, using the pertinent radiological parameters and geometrical information. The AAPM Task Group 190 (TG-190) was established to evaluate the accuracy of the DAP meter in 2008. Since then, the term “DAP-meter” has been revised to air kerma-area product (KAP) meter. The charge of TG 190 (Accuracy and Calibration of Integrated Radiation Output Indicators in Diagnostic Radiology) has also been realigned to investigate the “Accuracy and Calibration of Integrated Radiation Output Indicators” which is reflected in the title of the task group, to include situations where the KAP may be acquired with or without the presence of a physical “meter.” To accomplish this goal, validation test protocols were developed to compare the displayed radiation output value to an external measurement. These test protocols were applied to a number of clinical systems to collect information on the accuracy of dose display values in the field.

  7. Impact of ICRP 117 recommendations in the operational protection of vascular radiology unit; Impacto de las recomendaciones de ICRP 117 en la proteccion operacional de una unidad de radiologia vascular

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Pablo Luis; Fernandez, Manuel; Verde, Jose Maria; Perez, Maria Esperanza; Gomez, Nuria, E-mail: pablog11@eresmas.com [Hospital Universitario de Salamanca (Spain). Servicio de Radio fisica y Proteccion Radiologica

    2013-07-01

    This paper lists and discusses the results obtained in the teams of the different specialties: traumatology, gastroenterology, hemodynamics, vascular radiology and neurosurgery at different care centres with various care portfolios and notable differences of technical resources. The results show a noticeable difference between the equipment used in gastroenterology, vascular radiology and hemodynamic reference services with other services and disciplines. Taking into account the recent 117 of ICRP publication it has been initiated a procedure for the estimation of dose of foot and ankle of the vascular radiologists and in crystalline. This paper shows the results obtained as well as the correlations between the mentioned area dose and values of dose of lapel, wrist, ankles and crystalline of the professionals.

  8. An image-based skeletal dosimetry model for the ICRP reference adult female—internal electron sources

    Science.gov (United States)

    O'Reilly, Shannon E.; DeWeese, Lindsay S.; Maynard, Matthew R.; Rajon, Didier A.; Wayson, Michael B.; Marshall, Emily L.; Bolch, Wesley E.

    2016-12-01

    An image-based skeletal dosimetry model for internal electron sources was created for the ICRP-defined reference adult female. Many previous skeletal dosimetry models, which are still employed in commonly used internal dosimetry software, do not properly account for electron escape from trabecular spongiosa, electron cross-fire from cortical bone, and the impact of marrow cellularity on active marrow self-irradiation. Furthermore, these existing models do not employ the current ICRP definition of a 50 µm bone endosteum (or shallow marrow). Each of these limitations was addressed in the present study. Electron transport was completed to determine specific absorbed fractions to both active and shallow marrow of the skeletal regions of the University of Florida reference adult female. The skeletal macrostructure and microstructure were modeled separately. The bone macrostructure was based on the whole-body hybrid computational phantom of the UF series of reference models, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 years-old female cadaver. The active and shallow marrow are typically adopted as surrogate tissue regions for the hematopoietic stem cells and osteoprogenitor cells, respectively. Source tissues included active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume, and cortical bone surfaces. Marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. All other sources were run at the defined ICRP Publication 70 cellularity for each bone site. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or analytically modeled. The method of combining skeletal macrostructure and microstructure absorbed fractions assessed using MCNPX electron transport was found to yield results similar to those determined with the PIRT model applied to the UF adult male skeletal dosimetry model. Calculated

  9. Comparison of ICRP 67 and Other Plutonium Systemic Model Predictions with the Biokinetic Data from Nonhuman Primates.

    Science.gov (United States)

    Poudel, Deepesh; Krage, Eric Stephen; Brey, Richard Ray; Guilmette, Raymond A

    2016-04-01

    Despite the presence of a relatively large amount of human data available on the metabolism of plutonium, the experimental animal data is still important in constructing and parameterizing the biokinetic models. Recognizing this importance, the biokinetic data obtained from studies done by P.W. Durbin in nonhuman primates (NHP) were evaluated against the ICRP 67 systemic model and the two human models developed thereafter. The default transfer rates recommended for adult humans in these models predict the urinary excretion in NHP to a certain extent. However, they were unable to describe the fecal excretion rates several days post intake and the activities in skeleton and liver at the time of the death. These inconsistencies between the human reference models and the NHP biokinetic data are the result of metabolic and physiological differences between the species, as demonstrated by early biokinetic studies.

  10. Compilation of nuclear decay data used for dose calculation. Revised data for radionuclides listed in ICRP Publication 38

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    New nuclear decay data used for dose calculation have been compiled for 817 radionuclides that are listed in ICRP Publication 38 (Publ. 38) and for 6 additional isomers. The decay data were prepared using decay data sets from the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Basic nuclear properties in the decay data sets that are particularly important for calculating energies and intensities of emissions were examined and updated by referring to NUBASE, the database for nuclear and decay properties of nuclides. The reviewed and updated data were half-life, decay mode and its branching ratio, spin and parity of the ground and isomeric states, excitation energy of isomers, and Q value. In addition, possible revisions of partial and incomplete decay data sets were done for their format and syntax errors, level schemes, normalization records, and so on. After that, the decay data sets were processed by EDISTR in order to compute the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformation. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were prepared in two different types of format: Publ. 38 and NUCDECAY formats. Comparison of the compiled decay data with those in Publ. 38 was also presented. The decay data will be widely used for internal and external dose calculations in radiation protection and will be beneficial to a future revision of ICRP Publ. 38. (author)

  11. Tarefa N-back auditiva: desempenho entre diferentes grupos etários Auditory N-back task: different age groups performance

    Directory of Open Access Journals (Sweden)

    Tatiana De Nardi

    2013-01-01

    Full Text Available Um dos instrumentos mais utilizados internacionalmente para avaliação da Memória de Trabalho (MT é a Tarefa N-back Auditiva. Recursos para avaliação desse sistema são escassos no Brasil. O presente estudo objetiva observar o desempenho da Tarefa N-back Auditiva em indivíduos de diferentes faixas etárias: 27 crianças, 22 pré-adolescentes, 26 adultos e 27 idosos. Os resultados mostram que o grupo etário influencia no desempenho da Tarefa N-back Auditiva. A acurácia foi aumentando na transição da infância para a pré-adolescência e seguiu em crescimento até a adultez. Observou-se um declínio no desempenho de idosos. Os dados da Tarefa N-back Auditiva corrobora a trajetória desenvolvimental, sugerindo que essa tarefa possa ser utilizada no contexto experimental. Pesquisas de normatização contribuirão para melhor compreensão dessa tarefa.One of the most internationally used instruments for evaluation of Working Memory (WM is the Auditory N-Back Task. In Brazil, resources to evaluate this system are scarce. The aim of this study is to investigate the performance of different age subjects in auditory n-back tasks. We divided the 102 subjects in four groups: 27 children, 22 adolescents, 26 young adults and 27 older adults. The results demonstrate an age-related difference in the n-back task performance. The accuracy increased in the transition from childhood to adolescence and kept growing from adolescence to adulthood. We also found a decrease in the performance of aged subjects. The Auditory N-Back Task results are in agreement with WM development trajectory, and so, it demonstrates to be an adjusted instrument to evaluate this system in experimental setting.

  12. Defining a roadmap for harmonizing quality indicators in Laboratory Medicine: a consensus statement on behalf of the IFCC Working Group "Laboratory Error and Patient Safety" and EFLM Task and Finish Group "Performance specifications for the extra-analytical phases".

    Science.gov (United States)

    Sciacovelli, Laura; Panteghini, Mauro; Lippi, Giuseppe; Sumarac, Zorica; Cadamuro, Janne; Galoro, César Alex De Olivera; Pino Castro, Isabel Garcia Del; Shcolnik, Wilson; Plebani, Mario

    2017-08-28

    The improving quality of laboratory testing requires a deep understanding of the many vulnerable steps involved in the total examination process (TEP), along with the identification of a hierarchy of risks and challenges that need to be addressed. From this perspective, the Working Group "Laboratory Errors and Patient Safety" (WG-LEPS) of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) is focusing its activity on implementation of an efficient tool for obtaining meaningful information on the risk of errors developing throughout the TEP, and for establishing reliable information about error frequencies and their distribution. More recently, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has created the Task and Finish Group "Performance specifications for the extra-analytical phases" (TFG-PSEP) for defining performance specifications for extra-analytical phases. Both the IFCC and EFLM groups are working to provide laboratories with a system to evaluate their performances and recognize the critical aspects where improvement actions are needed. A Consensus Conference was organized in Padova, Italy, in 2016 in order to bring together all the experts and interested parties to achieve a consensus for effective harmonization of quality indicators (QIs). A general agreement was achieved and the main outcomes have been the release of a new version of model of quality indicators (MQI), the approval of a criterion for establishing performance specifications and the definition of the type of information that should be provided within the report to the clinical laboratories participating to the QIs project.

  13. Comparison between Brazilian radiation protection standard and the recommendation of the International Commission on Radiological Protection published in 2007; Comparacao entre a norma brasileira de radioprotecao e a recomendacao da International Commission on Radiological Protection - ICRP, publicadas em 2007

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S. [Industrias Nucleares do Brasil (INB), Itatiaia, RJ (Brazil). Fabrica do Combustivel Nuclear. Servico de Radioprotecao; Kelecom, A. [Universidade Federal Fluminense (LARARA-PLS/GETA/UFF), Niteroi, RJ (Brazil). Grupo de Estudos em Temas Ambientais. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Pereira, J.R.S. [Universidade Veiga de Almeida (UVA), Rio de Janeiro, RJ (Brazil). Curso de Graduacao em Direito

    2015-07-01

    This study aims to evaluate the differences between the CNEN's standard and the publication of ICRP-103, analyzing the philosophy for radiation protection, dose limits and other relevant aspects of radiation protection.

  14. Radiation Protection in Brachytherapy. Report of the SEFM Task Group on Brachytherapy; Proteccion radiologica en Braquiterapia. Informe del grupo de trabajo de Braquiterapia de la SEFM

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Calatayud, J.; Corredoira Silva, E.; Crispin Contreras, V.; Eudaldo Puell, T.; Frutos Baraja, J. de; Pino Sorroche, F.; Pujades Claumarchirant, M. C.; Richart Sancho, J.

    2015-07-01

    This document presents the report of the Brachytherapy Task Group of the Spanish Society of Medical Physics. It is dedicated to the radiation protection aspects involved in brachytherapy. The aim of this work is to include the more relevant aspects related to radiation protection issues that appear in clinical practice, and for the current equipment in Spain. Basically this report focuses on the typical contents associated with high dose rate brachytherapy with {sup 1}92Ir and {sup 6}0Co sources, and permanent seed implants with {sup 1}25I, {sup 1}03Pd and {sup 1}31Cs, which are the most current and widespread modalities. Ophthalmic brachytherapy (COMS with {sup 1}25I, {sup 1}06Ru, {sup 9}0Sr) is also included due to its availability in a significant number of spanish hospitals. The purpose of this report is to assist to the medical physicist community in establishing a radiation protection program for brachytherapy procedures, trying to solve some ambiguities in the application of legal requirements and recommendations in clinical practice. (Author)

  15. Results of the second Round Robin on opening-load measurement conducted by ASTM Task Group E24.04.04 on crack closure measurement and analysis

    Science.gov (United States)

    Phillips, E. P.

    1993-01-01

    A second experimental Round Robin on the measurement of the crack opening load in fatigue crack growth tests has been completed by the ASTM Task Group E24.04.04 on Crack Closure Measurement and Analysis. Fourteen laboratories participated in the testing of aluminum alloy compact tension specimens. Opening-load measurements were made at three crack lengths during constant Delta K, constant stress ratio tests by most of the participants. Four participants made opening-load measurements during threshold tests. All opening-load measurements were based on the analysis of specimens compliance behavior, where the displacement/strain was measured either at the crack mouth or the mid-height back face location. The Round Robin data were analyzed for opening load using two non-subjective analysis methods: the compliance offset and the correlation coefficient methods. The scatter in the opening load results was significantly reduced when some of the results were excluded from the analysis population based on an accept/reject criterion for raw data quality. The compliance offset and correlation coefficient opening load analysis methods produced similar results for data populations that had been screened to eliminate poor quality data.

  16. Compilation of nuclear decay data used for dose calculations. Data for radionuclides not listed in ICRP publication 38

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Akira; Yamaguchi, Yasuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Tamura, Tsutomu

    1999-07-01

    Nuclear decay data used for dose calculations were compiled for 162 nuclides with half-lives greater than or equal to 10 min that are not listed in ICRP Publication 38 (Publ. 38) and their 28 daughter nuclides. Additional 14 nuclides that are considered to be important in fusion reactor facilities were also included. The data were compiled using decay data sets of the Evaluated Nuclear Structure Data File (ENSDF), the latest version in August 1997. Investigations of the data sets were performed to check their consistency by referring to recent literature and NUBASE, the database for nuclear and decay properties of nuclides, and by using the utility programs of ENSDF. Possible revisions of the data sets were made for their format and syntax errors, level schemes, normalization records, and so on. The revised data sets were processed by EDISTR in order to calculate the energies and intensities of {alpha} particles, {beta} particles, {gamma} rays including annihilation photons, internal conversion electrons, X rays, and Auger electrons emitted in nuclear transformations of the radionuclides. For spontaneously fissioning nuclides, the average energies and intensities of neutrons, fission fragments, prompt {gamma} rays, delayed {gamma} rays, and {beta} particles were also calculated. The compiled data were presented in two types of format; Publ. 38 and NUCDECAY formats. This report provides the decay data in the Publ. 38 format along with decay scheme drawings. The data will be widely used for internal and external dose calculations in radiation protection. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.

    2003-09-10

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

  18. A comparison of radiological risk assessment models: Risk assessment models used by the BEIR V Committee, UNSCEAR, ICRP, and EPA (for NESHAP)

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, L.E.

    1994-03-01

    Radiological risk assessments and resulting risk estimates have been developed by numerous national and international organizations, including the National Research Council`s fifth Committee on the Biological Effects of Ionizing Radiations (BEIR V), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the International Commission on Radiological Protection (ICRP). A fourth organization, the Environmental Protection Agency (EPA), has also performed a risk assessment as a basis for the National Emission Standards for Hazardous Air Pollutants (NESHAP). This paper compares the EPA`s model of risk assessment with the models used by the BEIR V Committee, UNSCEAR, and ICRP. Comparison is made of the values chosen by each organization for several model parameters: populations used in studies and population transfer coefficients, dose-response curves and dose-rate effects, risk projection methods, and risk estimates. This comparison suggests that the EPA has based its risk assessment on outdated information and that the organization should consider adopting the method used by the BEIR V Committee, UNSCEAR, or ICRP.

  19. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  20. Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris; Shay, Jerry; Topol, Eric; Torry, Michael; Weier, Heinz-Ulrich G.; Tse, Iris; Lin, Su-Ju; Miller, Richard

    2007-11-14

    The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the potential to impact upon multiple body systems in ways that appear to accelerate the rates at which those systems age (Bernhard 2007). To document the role of chance events on aging, one must rigorously control both the genetic composition of an organism and its environment. This has been done to a remarkable degree in a species of nematodes, Caenorhabditis elegans (Vanfleteren 1998). The results confirm hundreds of previous studies with a wide range of species, especially those with inbred rodents housed under apparently identical but less well controlled environments. One

  1. Toward a standard for the evaluation of PET-Auto-Segmentation methods following the recommendations of AAPM task group No. 211: Requirements and implementation.

    Science.gov (United States)

    Berthon, Beatrice; Spezi, Emiliano; Galavis, Paulina; Shepherd, Tony; Apte, Aditya; Hatt, Mathieu; Fayad, Hadi; De Bernardi, Elisabetta; Soffientini, Chiara D; Ross Schmidtlein, C; El Naqa, Issam; Jeraj, Robert; Lu, Wei; Das, Shiva; Zaidi, Habib; Mawlawi, Osama R; Visvikis, Dimitris; Lee, John A; Kirov, Assen S

    2017-08-01

    The aim of this paper is to define the requirements and describe the design and implementation of a standard benchmark tool for evaluation and validation of PET-auto-segmentation (PET-AS) algorithms. This work follows the recommendations of Task Group 211 (TG211) appointed by the American Association of Physicists in Medicine (AAPM). The recommendations published in the AAPM TG211 report were used to derive a set of required features and to guide the design and structure of a benchmarking software tool. These items included the selection of appropriate representative data and reference contours obtained from established approaches and the description of available metrics. The benchmark was designed in a way that it could be extendable by inclusion of bespoke segmentation methods, while maintaining its main purpose of being a standard testing platform for newly developed PET-AS methods. An example of implementation of the proposed framework, named PETASset, was built. In this work, a selection of PET-AS methods representing common approaches to PET image segmentation was evaluated within PETASset for the purpose of testing and demonstrating the capabilities of the software as a benchmark platform. A selection of clinical, physical, and simulated phantom data, including "best estimates" reference contours from macroscopic specimens, simulation template, and CT scans was built into the PETASset application database. Specific metrics such as Dice Similarity Coefficient (DSC), Positive Predictive Value (PPV), and Sensitivity (S), were included to allow the user to compare the results of any given PET-AS algorithm to the reference contours. In addition, a tool to generate structured reports on the evaluation of the performance of PET-AS algorithms against the reference contours was built. The variation of the metric agreement values with the reference contours across the PET-AS methods evaluated for demonstration were between 0.51 and 0.83, 0.44 and 0.86, and 0.61 and 1

  2. Manitoba Task Force on Francophone Schools Governance. Report = Groupe de travail manitobain sur la gestion des ecoles franco-manitobaines. Le rapport.

    Science.gov (United States)

    Manitoba Dept. of Education and Training, Winnipeg.

    Findings of a task force on introduction of a school governance system for Manitoba's (Canada) francophone minority population are reported. The document outlines the background--i.e., the Canadian context--of this report, principles and procedures, the resulting recommended structure for governance, and suggestions for addressing such issues as…

  3. Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations.

    Science.gov (United States)

    Granlund, Christina; Thilander-Klang, Anne; Ylhan, Betȕl; Lofthag-Hansen, Sara; Ekestubbe, Annika

    2016-10-01

    During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19-75 μSv, depending on the panoramic equipment used. The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk-benefit profile of this technique must be assessed for the individual patient. The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used.

  4. Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS.

    Science.gov (United States)

    Chiu-Tsao, Sou-Tung; Astrahan, Melvin A; Finger, Paul T; Followill, David S; Meigooni, Ali S; Melhus, Christopher S; Mourtada, Firas; Napolitano, Mary E; Nath, Ravinder; Rivard, Mark J; Rogers, D W O; Thomson, Rowan M

    2012-10-01

    Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions. Recent Monte Carlo (MC)-based eye-plaque dosimetry simulations have demonstrated that the perturbation effects of heterogeneous materials in eye plaques, including the gold-alloy backing and Silastic insert, can be calculated with reasonable accuracy. Even additional levels of complexity introduced through the use of gold foil "seed-guides" and custom-designed plaques can be calculated accurately using modern MC techniques. Simulations accounting for the aforementioned complexities indicate dose discrepancies exceeding a factor of ten to selected critical structures compared to conventional dose calculations. Task Group 129 was formed to review the literature; re-examine the current dosimetry calculation formalism; and make recommendations for eye-plaque dosimetry, including evaluation of brachytherapy source dosimetry parameters and heterogeneity correction factors. A literature review identified modern assessments of dose calculations for Collaborative Ocular Melanoma Study (COMS) design plaques, including MC analyses and an intercomparison of treatment planning systems (TPS) detailing differences between homogeneous and heterogeneous plaque calculations using the American Association of Physicists in Medicine (AAPM) TG-43U1 brachytherapy dosimetry formalism and MC techniques. This review identified that a commonly used prescription dose of 85 Gy at 5 mm depth in homogeneous medium delivers about 75 Gy and 69 Gy at the same 5 mm depth for specific (125)I and (103)Pd sources, respectively, when accounting for COMS plaque heterogeneities. Thus, the adoption of

  5. Task A, High Energy Physics Program experiment and theory: Task B, High Energy Physics Program numerical simulation of quantum field theories. [Particle Physics Group, Physics Dept. , The Florida State Univ. , Tallahassee

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The effort of the experimental group has been concentrated on the CERN ALEPH and FERMILAB D0 collider experiments and completion of two fixed target experiments. The BNL fixed target experiment 771 took the world's largest sample of D(1285) and E/iota(1420) events, using pion, kaon and antiproton beams. Observing the following resonances: 0[sup [minus plus

  6. Novice supervisors' tasks and training

    DEFF Research Database (Denmark)

    Nielsen, Jan; Jacobsen, Claus Haugaard; Mathiesen, Birgit Bork

    2012-01-01

    were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least...... parallel to, the first supervisor tasks, preparing the novice supervisors for the often complicated tasks they are meeting....

  7. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons

    Science.gov (United States)

    Hadid, L.; Desbrée, A.; Schlattl, H.; Franck, D.; Blanchardon, E.; Zankl, M.

    2010-07-01

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  8. Application of the ICRP/ICRU reference computational phantoms to internal dosimetry: calculation of specific absorbed fractions of energy for photons and electrons.

    Science.gov (United States)

    Hadid, L; Desbrée, A; Schlattl, H; Franck, D; Blanchardon, E; Zankl, M

    2010-07-07

    The emission of radiation from a contaminated body region is connected with the dose received by radiosensitive tissue through the specific absorbed fractions (SAFs) of emitted energy, which is therefore an essential quantity for internal dose assessment. A set of SAFs were calculated using the new adult reference computational phantoms, released by the International Commission on Radiological Protection (ICRP) together with the International Commission on Radiation Units and Measurements (ICRU). Part of these results has been recently published in ICRP Publication 110 (2009 Adult reference computational phantoms (Oxford: Elsevier)). In this paper, we mainly discuss the results and also present them in numeric form. The emission of monoenergetic photons and electrons with energies ranging from 10 keV to 10 MeV was simulated for three source organs: lungs, thyroid and liver. SAFs were calculated for four target regions in the body: lungs, colon wall, breasts and stomach wall. For quality assurance purposes, the simulations were performed simultaneously at the Helmholtz Zentrum München (HMGU, Germany) and at the Institute for Radiological Protection and Nuclear Safety (IRSN, France), using the Monte Carlo transport codes EGSnrc and MCNPX, respectively. The comparison of results shows overall agreement for photons and high-energy electrons with differences lower than 8%. Nevertheless, significant differences were found for electrons at lower energy for distant source/target organ pairs. Finally, the results for photons were compared to the SAF values derived using mathematical phantoms. Significant variations that can amount to 200% were found. The main reason for these differences is the change of geometry in the more realistic voxel body models. For electrons, no SAFs have been computed with the mathematical phantoms; instead, approximate formulae have been used by both the Medical Internal Radiation Dose committee (MIRD) and the ICRP due to the limitations imposed

  9. Feasibility of an individual surveillance program on contamination with direct measurement methods based on the criteria established in the ICRP publication 54

    CERN Document Server

    Melandri, C

    1990-01-01

    If different methods of adequate sensitivity are available ICRP Publication 54, 'Individual Monitoring for Intakes-of Radionuclides by Workers: Design and Interpretations', recommends the use of direct measurements in individual monitoring for intakes of radionuclides. This report analyses the possibility to perform the different controls on the basis of the proposed Derived Reference Levels, respecting the accuracy requirement in evaluation of individual intake and dose. Therefore, general operative criteria are defined by analysing the potentialities and limitations of the different Whole Body Counters utilizable for the measurement with regard to the chemical, physical and metabolic characteristics of some radionuclides of particular interest in Radiation Protection. These criteria are useful for monitoring planning wherever a radiocontamination risk is possible.

  10. Fluence-to-dose conversion coefficients based on the posture modification of Adult Male (AM) and Adult Female (AF) reference phantoms of ICRP 110

    Science.gov (United States)

    Galeano, D. C.; Santos, W. S.; Alves, M. C.; Souza, D. N.; Carvalho, A. B.

    2016-04-01

    The aim of this work was to modify the standing posture of the anthropomorphic reference phantoms of ICRP publication 110, AM (Adult Male) and AF (Adult Female), to the sitting posture. The change of posture was performed using the Visual Monte Carlo software (VMC) to rotate the thigh region of the phantoms and position it between the region of the leg and trunk. Scion Image software was used to reconstruct and smooth the knee and hip contours of the phantoms in a sitting posture. For 3D visualization of phantoms, the VolView software was used. In the change of postures, the organ and tissue masses were preserved. The MCNPX was used to calculate the equivalent and effective dose conversion coefficients (CCs) per fluence for photons for six irradiation geometries suggested by ICRP publication 110 (AP, PA, RLAT, LLAT, ROT and ISO) and energy range 0.010-10 MeV. The results were compared between the standing and sitting postures, for both sexes, in order to evaluate the differences of scattering and absorption of radiation for different postures. Significant differences in the CCs for equivalent dose were observed in the gonads, colon, prostate, urinary bladder and uterus, which are present in the pelvic region, and in organs distributed throughout the body, such as the lymphatic nodes, muscle, skeleton and skin, for the phantoms of both sexes. CCs for effective dose showed significant differences of up to 16% in the AP irradiation geometry, 27% in the PA irradiation geometry and 13% in the ROT irradiation geometry. These results demonstrate the importance of using phantoms in different postures in order to obtain more precise conversion coefficients for a given exposure scenario.

  11. 基于遗传算法的导弹编队攻击任务优化分配策略%Strategy of Task Optimization Allocation for Missile Group-attack Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    白军; 刘新学; 郭峰; 高娟

    2011-01-01

    导弹编队攻击目标时,在确定打击目标和需求导弹数量后,如何把发射任务科学合理、高效地分配给相应的发射器,完成对目标的打击,在控制自身火力消耗最小的情况下实现作战效能最大是一个组合优化问题。针对导弹编队攻击任务分配问题,提出了基于遗传算法的优化分配策略。在理论上为常规导弹编队攻击目标时任务分配提供策略支持,对提高导弹部队任务分配决策能力和作战效能具有实际意义。%While missile group-assault target after determining the attack target and the number of needed missile,how to allocate the launch task to launcher in scientific,reasonable and efficient pattern so as to complete the attack for target is a combination optimization problem that makes operation effect be maximum under the condition of minimum in controlling itself force consumption.Aimed at the puzzle of task allocation in missile group-assault,the paper proposed the optimization strategy based on genetic algorithm.It can theoretically provide the strategy support for task allocation while missile group-assault target,and it is of actual significance to improve the efficiency of decision making and missile launching.for conventional missile troops.

  12. Potential hazard due to induced radioactivity secondary to radiotherapy: the report of task group 136 of the American Association of Physicists in Medicine.

    Science.gov (United States)

    Thomadsen, Bruce; Nath, Ravinder; Bateman, Fred B; Farr, Jonathan; Glisson, Cal; Islam, Mohammad K; LaFrance, Terry; Moore, Mary E; George Xu, X; Yudelev, Mark

    2014-11-01

    followed only if these actions are considered reasonable and practical in the individual clinics. Therapists working with proton beam and neutron beam units handle treatment devices that do become radioactive, and they should wear extremity monitors and make handling apertures and boluses their last task upon entering the room following treatment. Personnel doses from neutron-beam units can approach regulatory limits depending on the number of patients and beams, and strategies to reduce doses should be followed.

  13. Can it be better? Review of the Task Group ENINA of the Emission Registration; Kan het beter? Review van de taakgroep ENINA van de Emissieregistratie

    Energy Technology Data Exchange (ETDEWEB)

    Volkers, C.H.; Smekens, K.E.L. [ECN Beleidsstudies, Petten (Netherlands)

    2008-12-15

    This report presents the process and conclusions of a review process performed on the ENINA task force within the Dutch Emission Registration (ER). The review consisted of interviews with users of the emission data in the ER and of two sample checks of specific greenhouse gas emission calculation methods (for waste incineration and from other industrial gases). Since the interviews did not give any specific reason for further detailed investigation, the review was focussed on the process within ENINA itself. Although envisaged from the outline of the review, no clear points for improvement or simplification of the current process could be identified. However, some elements in the emission calculation process seemed redundant, like separate t-1 and t-2 emission estimates, determination of complementary emissions to the individual ones as well as total emission level estimates and a double checking of the data in the individual environmental reports. It became clear that for each of these points, valid reasons exist why they occur and hence there is no justification to reduce them. Technically the ENINA process proved to be sound and efficient, but on the communication - both internal as external - and documentation side improvements are certainly possible. For instance, reference documents or calculation factors are not always available and the used Protocols are not always up to date, complete or consistently reported. With small efforts, this could be brought on the same high level as with which the emission calculations take place. [Dutch] Dit rapport beschrijft de bevindingen van de review van de taakgroep ENINA van de Emissie-Registratie (ER). Deze review had tot doel om na te gaan of het proces van ENINA verbeterd vereenvoudigd of verbeterd kon worden. Tevens werd van twee werkvelden een sample check uitgevoerd waarbij werd gekeken of de berekende broeikasgasemissies konden worden nagerekend. Tijdens de analyse van het werkproces van de taakgroep ENINA zijn

  14. Proposal of Setting Up a Joint ESC / EAEE Working (Task Group on Updating of the Concept of Seismic Intensity and of the Seismic Intensity Scales

    Directory of Open Access Journals (Sweden)

    Horea SANDI

    2010-07-01

    Full Text Available The proposal presented subsequently was forwarded by the author, in August 2010, on the eve of the 14th European Conference on Earthquake Engineering, to:- Prof. Atilla Ansal, Secretary General, EAEE;- Dr. Mariano García-Fernández, Secretary General, ESC.This proposal was to a high extent a follow up of the project “Quantification of seismic action on structures” (2005-2008, in which research groups of institutes of Romania (coordination, Russian Federation and Republic Moldova were involved. A summary outcome of the project referred to is represented by the volume [Sandi & al., 2010a]. A brief presentation of the volume referred to is given in its foreword, reproduced in Annex II. The correspondence related to the submission of the proposal is reproduced in Annex III. A paper on this subject, [Sandi & al., 2010b], presented at the 14th European Conference on Earthquake Engineering, is also reproduced in this issue of the journal.

  15. 基于任务驱动和项目引领的小组协作Java教学模式研究%A Research on Java Teaching Pattern of Group Collaboration Based on Task Driven and Project Lead

    Institute of Scientific and Technical Information of China (English)

    李洁

    2015-01-01

    Aiming at the problems existing in Java teaching,this paper presents the thought and analysis of the method of solving problems. It also puts forward Java teaching pattern of group collaboration based on task driven and project lead which is always in a proj⁃ect throughout the course,takes task driven as the main content and considers group collaboration as the main way. The application shows that this method can improve and fully stimulate students’learning initiative.%针对Java教学中存在的问题,对问题解决方法进行了思考和分析,提出一种基于任务驱动和项目引领的小组协作Java教学模式,以一个项目贯穿课程始终,以任务驱动为主要环节,以小组协作为主要方式。实施应用表明,该方法能提高并充分调动学生的学习主动性。

  16. Overview on the dosimetric uncertainty analysis for photon-emitting brachytherapy sources, in the light of the AAPM Task Group No 138 and GEC-ESTRO report

    Science.gov (United States)

    DeWerd, Larry A.; Venselaar, Jack L. M.; Ibbott, Geoffrey S.; Meigooni, Ali S.; Stump, Kurt E.; Thomadsen, Bruce R.; Rivard, Mark J.

    2012-10-01

    In 2011, the American Association of Physicists in Medicine (AAPM) and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) published a report pertaining to uncertainties in brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization's Guide to the Expression of Uncertainty in Measurement and Technical Note 1297 by the National Institute of Standards and Technology are taken as reference standards for uncertainty formalism. Uncertainties involved in measurements or Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is given with uncertainties in each of the brachytherapy dosimetry parameters of the AAPM TG-43 dose-calculation formalism. For low-energy and high-energy brachytherapy sources of low dose-rate and high dose-rate, a combined dosimetric uncertainty AAPM and GEC-ESTRO for their members, and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for conventional brachytherapy sources used in routine clinical treatments.

  17. Waste area grouping 2 Phase I task data report: Ecological risk assessment and White Oak Creek watershed screening ecological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Efroymson, R.A.; Jackson, B.L.; Jones, D.S. [and others

    1996-05-01

    This report presents an ecological risk assessment for Waste Area Grouping (WAG) 2 based on the data collected in the Phase I remedial investigation (RI). It serves as an update to the WAG 2 screening ecological risk assessment that was performed using historic data. In addition to identifying potential ecological risks in WAG 2 that may require additional data collection, this report serves to determine whether there are ecological risks of sufficient magnitude to require a removal action or some other expedited remedial process. WAG 2 consists of White Oak Creek (WOC) and its tributaries downstream of the Oak Ridge National Laboratory (ORNL) main plant area, White Oak Lake (WOL), the White Oak Creek Embayment of the Clinch River, associated flood plains, and the associated groundwater. The WOC system drains the WOC watershed, an area of approximately 16.8 km{sup 2} that includes ORNL and associated WAGs. The WOC system has been exposed to contaminants released from ORNL and associated operations since 1943 and continues to receive contaminants from adjacent WAGs.

  18. Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167.

    Science.gov (United States)

    Nath, Ravinder; Rivard, Mark J; DeWerd, Larry A; Dezarn, William A; Thompson Heaton, H; Ibbott, Geoffrey S; Meigooni, Ali S; Ouhib, Zoubir; Rusch, Thomas W; Siebert, Frank-André; Venselaar, Jack L M

    2016-06-01

    Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved. The physicist's role, along with physician colleagues, in this process is highlighted for innovative brachytherapy devices and applications and includes evaluation of (1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, (2) risks and benefits from a regulatory and safety perspective, and (3) resource assessment and preparedness. Further, it is suggested that any developed calibration methods be traceable to a primary standards dosimetry laboratory (PSDL) such as the National Institute of Standards and Technology in the U.S. or to other PSDLs located elsewhere such as in Europe. Clinical users should follow standards as approved by their country's regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the Accredited Dosimetry Calibration Laboratories in the U.S. is encouraged before a source is introduced into widespread routine clinical use. The American Association of Physicists in Medicine and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) have developed guidelines for the safe and consistent application of brachytherapy using innovative devices and

  19. Report of the results of the fiscal 1997 regional consortium R and D project. Regional consortium energy field / R and D of a task adaptation type group architecture transfer robot system, TRIPTERS (first fiscal year); 1997 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium energy bun`ya / task tekigogata gun kosei hanso robot system TRIPTERS no kaihatsu kenkyu (daiichi nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper stated the fiscal 1997 result of the development of a task adaptation type group architecture transfer robot system (TRIPTERS) which can cope with changes in carrying task rapidly and flexibly. R and D were conducted mainly of various functional modules, the operation management technology which enables group architecture, and the basic design of a standardized transfer robot. As to the positioning, studied were the construction of the basic hardware of laser position measuring device, and the application method. Concerning the cooperative carrying, conducted were securing of positioning accuracy of matters to be carried, high speed heavy transfer control, and design of dead reckoning system. Relating to the operation management, passable areas were divided into more than one zones, and the effective path reservation method was constructed so that one and the same zone is not occupied. As to the environmental recognition/obstacle avoidance, developed were actual hour/distance acquisition equipment, and autonomous cars running according to the directions of the color sign recognition system by stereo CCD camera. Also conducted were the development of methods to recognize the distance to obstacles and to discriminate areas, the development of mobile sensor, and the basic experiment on running of the demonstration machine. 44 refs., 153 figs., 15 tabs.

  20. Game Analysis of Relationships between Emotion Conflicts and Tasks Perform Conflicts in Project Group%项目团队中情感与履行任务冲突关系博弈分析

    Institute of Scientific and Technical Information of China (English)

    万涛

    2011-01-01

    针对项目团队中存在冲突影响团队有效构建与和谐发展的问题,在现有的项目团队冲突经济行为研究成果基础上引进非经济行为分析,利用博弈论构建任务履行冲突(经济行为)与情感冲突(非经济行为)的关系理论模型,实例研究表明,该理论研究符合实际运作,为构建和谐的项目团队提供了理论依据.%Conflicts in project group are important factors affecting the effective establishment and harmonious development of project group. Non - economic behavior conflicts were analysed based on the research achievement of economic behavior conflicts in the existing project group. The relationship theoretical models were set up using tasks perform conflicts ( economic behaviors) and emotion conflicts ( non - economic behaviors) by game theory. The case indicates that the result accords with the practical operation;consequently it gives a basis for theory to establish the harmonious project group.

  1. NATO Task Group on Information Fusion

    Science.gov (United States)

    2004-04-01

    examples taken from a course in Intelligence for OOTW given by WO1 Dave Steer, Defence Intelligence and Security Centre , Chicksands, UK. All names and...Crissy BARNEY was seen by the Enterprise Centre , GR 7101 3523. She was alone. • 6 May at 142011rs, Allan KAUGNOT and Sean KAUGNOT were seen by CCTV sat...Mk 15 Mor 14 Jul Shoot 7 May //X/X//Mk 15 Mor 5 May WEAPONS A llan K A U G N O T A lly M O R R IS R obert K O K S Jim M cC BA LE Brian BY R R IS D

  2. Assessment of uncertainties in the lung activity measurement of low-energy photon emitters using Monte Carlo simulation of ICRP male thorax voxel phantom.

    Science.gov (United States)

    Nadar, M Y; Akar, D K; Rao, D D; Kulkarni, M S; Pradeepkumar, K S

    2015-12-01

    Assessment of intake due to long-lived actinides by inhalation pathway is carried out by lung monitoring of the radiation workers inside totally shielded steel room using sensitive detection systems such as Phoswich and an array of HPGe detectors. In this paper, uncertainties in the lung activity estimation due to positional errors, chest wall thickness (CWT) and detector background variation are evaluated. First, calibration factors (CFs) of Phoswich and an array of three HPGe detectors are estimated by incorporating ICRP male thorax voxel phantom and detectors in Monte Carlo code 'FLUKA'. CFs are estimated for the uniform source distribution in lungs of the phantom for various photon energies. The variation in the CFs for positional errors of ±0.5, 1 and 1.5 cm in horizontal and vertical direction along the chest are studied. The positional errors are also evaluated by resizing the voxel phantom. Combined uncertainties are estimated at different energies using the uncertainties due to CWT, detector positioning, detector background variation of an uncontaminated adult person and counting statistics in the form of scattering factors (SFs). SFs are found to decrease with increase in energy. With HPGe array, highest SF of 1.84 is found at 18 keV. It reduces to 1.36 at 238 keV. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Cardiac CT: are we underestimating the dose? A radiation dose study utilizing the 2007 ICRP tissue weighting factors and a cardiac specific scan volume

    Energy Technology Data Exchange (ETDEWEB)

    Gosling, O., E-mail: Oliver.gosling@pms.ac.u [Plymouth Hospitals NHS Trust, Derriford Hospital, Plymouth, Devon (United Kingdom); Loader, R.; Venables, P.; Rowles, N.; Morgan-Hughes, G. [Plymouth Hospitals NHS Trust, Derriford Hospital, Plymouth, Devon (United Kingdom); Roobottom, C. [Peninsula College of Medicine and Dentistry, University of Plymouth, Devon (United Kingdom)

    2010-12-15

    Aim: To calculate the effective dose from cardiac multidetector computed tomography (MDCT) using a computer-based model utilizing the latest International Commission on Radiation Protection (ICRP) 103 tissue-weighting factors (2007), to compare this dose with those calculated with previously published chest conversion factors and to produce a conversion factor specific for cardiac MDCT. Materials and methods: An observational study of 152 patients attending for cardiac MDCT as part of their usual clinical care in a university teaching hospital. The dose for each examination was calculated using the computer-based anthropomorphic ImPACT model (the imaging performance assessment of CT scanners) and this was compared with the dose derived from the dose-length product (DLP) and a chest conversion factor. Results: The median effective dose calculated using the ImPACT calculator (4.5 mSv) was significantly higher than the doses calculated with the chest conversion factors (2.2-3 mSv). Conclusion: The use of chest conversion factors significantly underestimates the effective dose when compared to the dose calculated using the ImPACT calculator. A conversion factor of 0.028 would give a better estimation of the effective dose from prospectively gated cardiac MDCT.

  4. Functionality and operation of fluoroscopic automatic brightness control/automatic dose rate control logic in modern cardiovascular and interventional angiography systems: a report of Task Group 125 Radiography/Fluoroscopy Subcommittee, Imaging Physics Committee, Science Council.

    Science.gov (United States)

    Rauch, Phillip; Lin, Pei-Jan Paul; Balter, Stephen; Fukuda, Atsushi; Goode, Allen; Hartwell, Gary; LaFrance, Terry; Nickoloff, Edward; Shepard, Jeff; Strauss, Keith

    2012-05-01

    Task Group 125 (TG 125) was charged with investigating the functionality of fluoroscopic automatic dose rate and image quality control logic in modern angiographic systems, paying specific attention to the spectral shaping filters and variations in the selected radiologic imaging parameters. The task group was also charged with describing the operational aspects of the imaging equipment for the purpose of assisting the clinical medical physicist with clinical set-up and performance evaluation. Although there are clear distinctions between the fluoroscopic operation of an angiographic system and its acquisition modes (digital cine, digital angiography, digital subtraction angiography, etc.), the scope of this work was limited to the fluoroscopic operation of the systems studied. The use of spectral shaping filters in cardiovascular and interventional angiography equipment has been shown to reduce patient dose. If the imaging control algorithm were programmed to work in conjunction with the selected spectral filter, and if the generator parameters were optimized for the selected filter, then image quality could also be improved. Although assessment of image quality was not included as part of this report, it was recognized that for fluoroscopic imaging the parameters that influence radiation output, differential absorption, and patient dose are also the same parameters that influence image quality. Therefore, this report will utilize the terminology "automatic dose rate and image quality" (ADRIQ) when describing the control logic in modern interventional angiographic systems and, where relevant, will describe the influence of controlled parameters on the subsequent image quality. A total of 22 angiography units were investigated by the task group and of these one each was chosen as representative of the equipment manufactured by GE Healthcare, Philips Medical Systems, Shimadzu Medical USA, and Siemens Medical Systems. All equipment, for which measurement data were

  5. SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms

    Science.gov (United States)

    Cros, Maria; Joemai, Raoul M. S.; Geleijns, Jacob; Molina, Diego; Salvadó, Marçal

    2017-08-01

    This study aims to develop and test software for assessing and reporting doses for standard patients undergoing computed tomography (CT) examinations in a 320 detector-row cone-beam scanner. The software, called SimDoseCT, is based on the Monte Carlo (MC) simulation code, which was developed to calculate organ doses and effective doses in ICRP anthropomorphic adult reference computational phantoms for acquisitions with the Aquilion ONE CT scanner (Toshiba). MC simulation was validated by comparing CTDI measurements within standard CT dose phantoms with results from simulation under the same conditions. SimDoseCT consists of a graphical user interface connected to a MySQL database, which contains the look-up-tables that were generated with MC simulations for volumetric acquisitions at different scan positions along the phantom using any tube voltage, bow tie filter, focal spot and nine different beam widths. Two different methods were developed to estimate organ doses and effective doses from acquisitions using other available beam widths in the scanner. A correction factor was used to estimate doses in helical acquisitions. Hence, the user can select any available protocol in the Aquilion ONE scanner for a standard adult male or female and obtain the dose results through the software interface. Agreement within 9% between CTDI measurements and simulations allowed the validation of the MC program. Additionally, the algorithm for dose reporting in SimDoseCT was validated by comparing dose results from this tool with those obtained from MC simulations for three volumetric acquisitions (head, thorax and abdomen). The comparison was repeated using eight different collimations and also for another collimation in a helical abdomen examination. The results showed differences of 0.1 mSv or less for absolute dose in most organs and also in the effective dose calculation. The software provides a suitable tool for dose assessment in standard adult patients undergoing CT

  6. Validation of the ICRP model for caesium intake by lactating mothers with Italian data after the Chernobyl fallout.

    Science.gov (United States)

    Giussani, Augusto; Risica, Serena

    2012-02-01

    In the aftermath of the Chernobyl nuclear power plant accident, a research group of the Italian National Institute of Health (Istituto Superiore di Sanità) carried out two research programmes on maternal milk. One concerned the transfer of caesium radionuclides from the diet to breast milk. In the other, the activity concentrations of (137)Cs were also determined in urine and placenta. The first study estimated the mothers' average (137)Cs dietary intake, in the second study the intake was evaluated individually for each subject. In 2004, the International Commission on Radiological Protection published modified systemic biokinetic models which also account for transfer to breast milk. The model for caesium radionuclides was implemented and tested by the authors with the experimental data described above. A good agreement was obtained between measured data and model simulations of (137)Cs activity concentration in human milk. The model, however, tends to systematically overestimate (137)Cs activity concentration in urine, in which case the agreement is to be considered satisfactory in terms of order of magnitude.

  7. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  8. Application of Multi-task Sparse Group Lasso Feature Extraction and Support Vector Machine Regression in the Stellar Atmospheric Parametrization%多任务Sparse Group Lasso特征提取与支持向量机回归在恒星大气物理参量估计中的应用∗

    Institute of Scientific and Technical Information of China (English)

    高伟; 李乡儒

    2016-01-01

    The multi-task learning puts the multiple tasks together to analyse and calculate for discovering the correlation between them, which can improve the accu-racy of analysis results. This kind of methods have been widely studied in machine learning, pattern recognition, computer vision, and other related fields. This paper investigates the application of multi-task learning in estimating the effective tempera-ture (Teff ), surface gravity (lg g), and chemical abundance ([Fe/H]). Firstly, the spectral characteristics of the three atmospheric physical parameters are extracted by using the multi-task Sparse Group Lasso algorithm, and then the support vector machine is used to estimate the atmospheric physical parameters. The proposed scheme is evaluated on both Sloan stellar spectra and theoretical spectra computed from Kurucz’s New Opacity Distribution Function (NEWODF) model. The mean absolute errors (MAEs) on the Sloan spectra are: 0.0064 for lg (Teff/K), 0.1622 for lg (g/(cm · s−2)), and 0.1221 dex for [Fe/H];The MAEs on synthetic spectra are 0.0006 for lg (Teff/K), 0.0098 for lg (g/(cm · s−2)), and 0.0082 dex for [Fe/H]. Experimental results show that the proposed scheme is excellent for atmospheric parameter estimation.%多任务学习(Multi-task Learning, MTL)就是把多个问题一起进行分析、计算,以发掘不同问题之间的相关性,提高分析结果的精度,该类方法已被广泛地应用于机器学习、模式识别、计算机视觉等领域.使用多任务学习方案研究了恒星大气物理参数中表面温度(Teff )、表面重力加速度(lg g)、化学丰度([Fe/H])的估计问题.首先使用多任务Sparse Group Lasso算法提取对3个大气物理参数均有预测能力的光谱特征;然后使用支持向量机估计恒星大气物理参数.该方案在Sloan实测恒星光谱和理论光谱上均做了测试.在实测光谱上的平均绝对误差分别为:0.0064(lg (Teff/K)),0.1622(lg (g/(cm·s−2))),0.1221 dex

  9. World Association of Sleep Medicine (WASM) 2016 standards for recording and scoring leg movements in polysomnograms developed by a joint task force from the International and the European Restless Legs Syndrome Study Groups (IRLSSG and EURLSSG).

    Science.gov (United States)

    Ferri, R; Fulda, S; Allen, R P; Zucconi, M; Bruni, O; Chokroverty, S; Ferini-Strambi, L; Frauscher, B; Garcia-Borreguero, D; Hirshkowitz, M; Högl, B; Inoue, Y; Jahangir, A; Manconi, M; Marcus, C L; Picchietti, D L; Plazzi, G; Winkelman, J W; Zak, R S

    2016-10-01

    This report presents the results of the work by a joint task force of the International and European Restless Legs Syndrome Study Groups and World Association of Sleep Medicine that revised and updated the current standards for recording and scoring leg movements (LM) in polysomnographic recordings (PSG). First, the background of the decisions made and the explanations of the new rules are reported and then specific standard rules are presented for recording, detecting, scoring and reporting LM activity in PSG. Each standard rule has been classified with a level of evidence. At the end of the paper, Appendix 1 provides algorithms to aid implementation of these new standards in software tools. There are two main changes introduced by these new rules: 1) Candidate LM (CLM), are any monolateral LM 0.5-10 s long or bilateral LM 0.5-15 s long; 2) periodic LM (PLM) are now defined by runs of at least four consecutive CLM with an intermovement interval ≥10 and ≤ 90 s without any CLM preceded by an interval  0.5 s regardless of duration, otherwise the technician scores the LM as for the old standards. There is a new criterion for the morphology of LM that applies only to computerized LM detection to better match expert visual detection. Available automatic scoring programs will incorporate all the new rules so that the new standards should reduce technician burden for scoring PLMS. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Group Anonymity

    CERN Document Server

    Chertov, Oleg; 10.1007/978-3-642-14058-7_61

    2010-01-01

    In recent years the amount of digital data in the world has risen immensely. But, the more information exists, the greater is the possibility of its unwanted disclosure. Thus, the data privacy protection has become a pressing problem of the present time. The task of individual privacy-preserving is being thoroughly studied nowadays. At the same time, the problem of statistical disclosure control for collective (or group) data is still open. In this paper we propose an effective and relatively simple (wavelet-based) way to provide group anonymity in collective data. We also provide a real-life example to illustrate the method.

  11. Task-specificity of balance training.

    Science.gov (United States)

    Giboin, Louis-Solal; Gruber, Markus; Kramer, Andreas

    2015-12-01

    Despite much research on balance training, it is still unclear whether balance training leads to highly task-specific adaptations or rather non-specific adaptations. Hence, in this study we examined whether balance training increased performance only in the balance task that was trained or also in non-trained tasks. Forty healthy participants (28 m 12 f, 25 ± 4 years, 177 ± 10 cm, 73 ± 14 kg) were assigned to one of two training groups (TGs) or a control group. Both TGs completed six sessions over 2 weeks, only the training device differed. Before and after the training, performance in the trained task as well as in additional untrained tasks was recorded. ANOVAs showed that each TG outperformed the other groups only in the task they had trained (e.g., task trained by TG1: +225% in TG1, only +41% and +30% in TG2 and control, group*time interaction, pbalance training resulted in highly task-specific effects, no transfer even to very similar tasks was observed. Therefore, we recommend identifying and training exactly those tasks that need improvement, and test the efficacy of training programs using specific tests instead of general tests with limited functional relevance.

  12. "Task" as Research Construct

    Science.gov (United States)

    Seedhouse, Paul

    2005-01-01

    The article examines "task" as research construct as predominantly conceived in terms of task-as-workplan in the task-based learning/second language acquisition literature. It is suggested that "task" has weak construct validity and ontology in an overwhelmingly quantitative paradigm because the construct has a "split personality."…

  13. Recalling academic tasks

    Science.gov (United States)

    Draper, Franklin Gno

    This study was focused on what students remembered about five middle school science tasks when they were juniors and seniors in high school. Descriptions of the five tasks were reconstructed from available artifacts and teachers' records, notes and recollections. Three of the five tasks were "authentic" in the sense that students were asked to duplicate the decisions practitioners make in the adult world. The other two tasks were more typical school tasks involving note taking and preparation for a quiz. All five tasks, however, involved use of computers. Students were interviewed to examine what and how well they recalled the tasks and what forms or patterns of recall existed. Analysis of their responses indicated that different kinds of tasks produced different levels of recall. Authentically situated tasks were remembered much better than routine school tasks. Further, authentic tasks centered on design elements were recalled better than those for which design was not as pivotal. Patterns of recall indicated that participants most often recalled the decisions they made, the scenarios of the authentically situated tasks, the consequences of their tasks and the social contexts of the classroom. Task events, in other words, appeared to form a framework upon which students constructed stories of the tasks. The more salient the events, the richer the story, the deeper and more detailed the recall of the task. Thus, authentic tasks appeared to lend themselves to creating stories better than regular school tasks and therefore such tasks were recalled better. Implications of these patterns of recall are discussed with respect to issues of school learning and assessment.

  14. Kokkos? Task DAG Capabilities.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Harold C.; Ibanez, Daniel Alejandro

    2017-09-01

    This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

  15. Task Allocation Strategy Based on Game Theory in Group Computing%群体计算中基于博弈论的任务分配策略❋

    Institute of Scientific and Technical Information of China (English)

    刘鸣; 彭成; 满君丰; 刘美博; 杜坤

    2016-01-01

    The rapid development of big data promotes the progress of economy and technology,but the features,low value density,bring challenges to the big data.These features make that it need urgently complex cognitive reasoning,which is effectively solved by human-machine collaboration based crowd computing.However,crowd computing’s task allocation strategy is not maturity completely.some scholars have come up with a theme-aware task assignment framework,which solves task allocation to different professional background and knowledge level,but it does not deal with task allocation invol-ving same knowledge level and professional background,which makes higher computational efficiency.To deal with this problem,it propose a task allocation algorithm based on game theory,which detects the accuracy with same professional and knowledge level.The task allocation algorithm based on game theory,compared with randomly task allocation,shows the accuracy of game theory algorithm.%大数据的快速发展,推动了社会经济和科技的发展,但大数据的价值密度低等特点为其发展带来了挑战。大数据的这些特点使得大数据迫切需要复杂认知的推理技术,而人机协作的群体计算成为了复杂认知推理技术的有效途径,但其任务分配策略还尚未完善。尽管已经有学者提出了基于用户主题感知的任务分配策略,解决了涉及不同专业背景及不同知识水平的任务分配,但并未解决处于同层次知识水平和专业背景的用户如何分配任务,使得计算效率更高。针对此问题,提出了基于博弈论的任务分配算法,检测相同专业背景和知识水平的人群完成任务的准确率,与任务随机分配相比较,突出博弈论算法的准确性。

  16. The Impact of Task Complexity and Strategic Planning Time on EFL Learners’Accuracy and Fluency in Written Task Production

    National Research Council Canada - National Science Library

    Salimi, Asghar; Alavinia, Parviz; Hosseini, Parvin; Shafaei, Ali

    2012-01-01

    ... in the literature on the joint effects of task complexity and types of pre-task planning on L2 learners’ performance. The present study investigates the effects of strategic pre-task planning time and task complexity on a group of L2 learners...

  17. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  18. Launching Complex Tasks

    Science.gov (United States)

    Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.

    2012-01-01

    Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…

  19. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching fr

  20. Tackling obesity in areas of high social deprivation: clinical effectiveness and cost-effectiveness of a task-based weight management group programme - a randomised controlled trial and economic evaluation.

    Science.gov (United States)

    McRobbie, Hayden; Hajek, Peter; Peerbux, Sarrah; Kahan, Brennan C; Eldridge, Sandra; Trépel, Dominic; Parrott, Steve; Griffiths, Chris; Snuggs, Sarah; Myers Smith, Katie

    2016-10-01

    An increasing number of people require help to manage their weight. The NHS recommends weight loss advice by general practitioners and/or a referral to a practice nurse. Although this is helpful for some, more effective approaches that can be disseminated economically on a large scale are needed. To assess whether or not a task-based weight management programme [Weight Action Programme (WAP)] has better long-term effects than a 'best practice' intervention provided in primary care by practice nurses. Randomised controlled trial with cost-effectiveness analysis. General practices in east London, UK. Three hundred and thirty adults with a body mass index (BMI) of ≥ 30 kg/m(2) or a BMI of ≥ 28 kg/m(2) plus comorbidities were recruited from local general practices and via media publicity. Those who had a BMI of > 45 kg/m(2), had lost > 5% of their body weight in the previous 6 months, were currently pregnant or taking psychiatric medications were excluded. Participants were randomised (2 : 1) to the WAP or nurse arms. The WAP intervention was delivered in eight weekly group sessions that combined dietary and physical activity, advice and self-monitoring in a group-oriented intervention. The initial course was followed by 10 monthly group maintenance sessions open to all participants in this study arm. The practice nurse intervention (best usual care) consisted of four one-to-one sessions delivered over 8 weeks, and included standard advice on diet and physical activity based on NHS 'Change4Life' materials and motivational support. The primary outcome measure was weight change at 12 months. Secondary outcome measures included change in BMI, waist circumference and blood pressure, and proportion of participants losing at least 5% and 10% of baseline body weight. Staff collecting measurements at the 6- and 12-month follow-ups were blinded to treatment allocation. The primary outcome measure was analysed according to the intention-to-treat principle

  1. Cohesiveness and Performance on an Additive Task: Evidence for Multidimensionality.

    Science.gov (United States)

    Zaccaro, Stephen J.; Lowe, Charles A.

    1988-01-01

    Presents a study designed to contrast the effects of task-based and interpersonal cohesiveness on group performance of students. Concludes that high task cohesion helped group performance, while interpersonal attraction had no apparent effect. Finding that increased interpersonal cohesion improved task commitment, the authors suggest that…

  2. Relative contributions of task-relevant and task-irrelevant dimensions in priming of pop-out.

    Science.gov (United States)

    Michal, Audrey L; Lleras, Alejandro; Beck, Diane M

    2014-10-13

    Intertrial effects such as priming of pop-out (PoP) often occur for task-irrelevant dimensions as well as task-relevant dimensions, though to a weaker extent. Here we test the hypothesis that increased priming for task-relevant dimensions is due to greater passive build-up of priming for the task-relevant dimension rather than to an active filtering of task-irrelevant dimensions; if this is the case, then we should observe a positive correlation between the magnitude of task-relevant and task-irrelevant priming. We tested this hypothesis using a pop-out search task in which the task-relevant dimension was orientation and the task-irrelevant dimension was color. We found a strong, positive association between task-relevant and task-irrelevant priming across a large group of participants (N = 100); additionally, we observed increased priming over consecutive repetitions for the task-relevant dimension, whereas task-irrelevant priming was constant across multiple repetitions. As further evidence against an active filtering account, task-irrelevant priming showed no systematic relationship with visual short-term memory capacity, which has been shown to correlate with filtering ability. Together, our results suggest that task-irrelevant dimensions are co-selected rather than filtered out during target search. Further, increased task-relevant priming may reflect an enhanced representation of the task-relevant dimension that is reinforced over consecutive repetitions. © 2014 ARVO.

  3. Error Sonification of a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Riener Robert

    2011-12-01

    Full Text Available Visual information is mainly used to master complex motor tasks. Thus, additional information providing augmented feedback should be displayed in other modalities than vision, e.g. hearing. The present work evaluated the potential of error sonification to enhance learning of a rowing-type motor task. In contrast to a control group receiving self-controlled terminal feedback, the experimental group could not significantly reduce spatial errors. Thus, motor learning was not enhanced by error sonification, although during the training the participant could benefit from it. It seems that the motor task was too slow, resulting in immediate corrections of the movement rather than in an internal representation of the general characteristics of the motor task. Therefore, further studies should elaborate the impact of error sonification when general characteristics of the motor tasks are already known.

  4. Learning redundant motor tasks with and without overlapping dimensions: facilitation and interference effects.

    Science.gov (United States)

    Ranganathan, Rajiv; Wieser, Jon; Mosier, Kristine M; Mussa-Ivaldi, Ferdinando A; Scheidt, Robert A

    2014-06-11

    Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills.

  5. Musical expertise has minimal impact on dual task performance.

    Science.gov (United States)

    Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

    2017-05-01

    Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

  6. Overview of the ID, EPI and REL tasks of BioNLP Shared Task 2011

    Directory of Open Access Journals (Sweden)

    Pyysalo Sampo

    2012-06-01

    Full Text Available Abstract We present the preparation, resources, results and analysis of three tasks of the BioNLP Shared Task 2011: the main tasks on Infectious Diseases (ID and Epigenetics and Post-translational Modifications (EPI, and the supporting task on Entity Relations (REL. The two main tasks represent extensions of the event extraction model introduced in the BioNLP Shared Task 2009 (ST'09 to two new areas of biomedical scientific literature, each motivated by the needs of specific biocuration tasks. The ID task concerns the molecular mechanisms of infection, virulence and resistance, focusing in particular on the functions of a class of signaling systems that are ubiquitous in bacteria. The EPI task is dedicated to the extraction of statements regarding chemical modifications of DNA and proteins, with particular emphasis on changes relating to the epigenetic control of gene expression. By contrast to these two application-oriented main tasks, the REL task seeks to support extraction in general by separating challenges relating to part-of relations into a subproblem that can be addressed by independent systems. Seven groups participated in each of the two main tasks and four groups in the supporting task. The participating systems indicated advances in the capability of event extraction methods and demonstrated generalization in many aspects: from abstracts to full texts, from previously considered subdomains to new ones, and from the ST'09 extraction targets to other entities and events. The highest performance achieved in the supporting task REL, 58% F-score, is broadly comparable with levels reported for other relation extraction tasks. For the ID task, the highest-performing system achieved 56% F-score, comparable to the state-of-the-art performance at the established ST'09 task. In the EPI task, the best result was 53% F-score for the full set of extraction targets and 69% F-score for a reduced set of core extraction targets, approaching a level

  7. What Task Designers Do.

    Science.gov (United States)

    Johnson, Keith

    2000-01-01

    Describes a research project that is concerned with the design procedures followed by those engaged in designing pedagogic tasks for use in classrooms. Focuses on the part of the project that involves actual observation of designers in the process of developing one specific task for class use. Findings are presented under three headers: control…

  8. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is fragme......There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, and recommendations, and supporting exploratory search to sensemaking and analytics, UI and UX design pose an overconstrained challenge. How do we know that our approach is any good? Supporting complex search task requires new collaborations across the whole field of IR, and the proposed workshop will bring together...

  9. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo;

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  10. Improving multi-tasking ability through action videogames.

    Science.gov (United States)

    Chiappe, Dan; Conger, Mark; Liao, Janet; Caldwell, J Lynn; Vu, Kim-Phuong L

    2013-03-01

    The present study examined whether action videogames can improve multi-tasking in high workload environments. Two groups with no action videogame experience were pre-tested using the Multi-Attribute Task Battery (MATB). It consists of two primary tasks; tracking and fuel management, and two secondary tasks; systems monitoring and communication. One group served as a control group, while a second played action videogames a minimum of 5 h a week for 10 weeks. Both groups returned for a post-assessment on the MATB. We found the videogame treatment enhanced performance on secondary tasks, without interfering with the primary tasks. Our results demonstrate action videogames can increase people's ability to take on additional tasks by increasing attentional capacity.

  11. Task-baseret kommunikativ sprogundervisning

    DEFF Research Database (Denmark)

    Pedersen, Michael Svendsen

    2015-01-01

    Definition af task-baseret sprogundervisning, kriterier for task. Forskning i Second Language Acquisition med brug af task, tilrettelæggelse af task-baseret kommunikativ undervisning. Begrænsninger i og perspektiver for videreudvikling af task-baseret sprogundervising-......Definition af task-baseret sprogundervisning, kriterier for task. Forskning i Second Language Acquisition med brug af task, tilrettelæggelse af task-baseret kommunikativ undervisning. Begrænsninger i og perspektiver for videreudvikling af task-baseret sprogundervising-...

  12. Single-Task and Dual-Task Gait Among Collegiate Athletes of Different Sport Classifications: Implications for Concussion Management.

    Science.gov (United States)

    Howell, David R; Oldham, Jessie R; DiFabio, Melissa; Vallabhajosula, Srikant; Hall, Eric E; Ketcham, Caroline J; Meehan, William P; Buckley, Thomas A

    2017-02-01

    Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.

  13. Reconsideration of the simulated work task situation

    DEFF Research Database (Denmark)

    Borlund, Pia; Schneider, Jesper Wiborg

    2010-01-01

    The present paper reports on the initial study and the preliminary findings of how the concept of simulated work task situation is reported used in the research literature. The overall objective of the study is in a systematic manner to learn how and for what types of evaluations the concept...... is applied. In particular we are interested to learn whether the recommendations for how to apply simulated work task situations are followed. The preliminary findings indicate a need for clarifications of the recommendations of how to use simulated work task situations. Particularly with respect to ‘realism......’ of the simulated work task situations, which is emphasised through the need for tailoring of the simulated work task situations towards the group of study participant to ensure the depicted situations are realistic and interesting from the participants’ point of view. Likewise it seems that the recommendation...

  14. Task-specific dystonia: pathophysiology and management.

    Science.gov (United States)

    Sadnicka, Anna; Kassavetis, Panagiotis; Pareés, Isabel; Meppelink, Anne Marthe; Butler, Katherine; Edwards, Mark

    2016-09-01

    Task-specific dystonia is a form of isolated focal dystonia with the peculiarity of being displayed only during performance of a specific skilled motor task. This distinctive feature makes task-specific dystonia a particularly mysterious and fascinating neurological condition. In this review, we cover phenomenology and its increasingly broad-spectrum risk factors for the disease, critically review pathophysiological theories and evaluate current therapeutic options. We conclude by highlighting the unique features of task-specific dystonia within the wider concept of dystonia. We emphasise the central contribution of environmental risk factors, and propose a model by which these triggers may impact on the motor control of skilled movement. By viewing task-specific dystonia through this new lens which considers the disorder a modifiable disorder of motor control, we are optimistic that research will yield novel therapeutic avenues for this highly motivated group of patients.

  15. Supporting Teachers in Structuring Mathematics Lessons Involving Challenging Tasks

    Science.gov (United States)

    Sullivan, Peter; Askew, Mike; Cheeseman, Jill; Clarke, Doug; Mornane, Angela; Roche, Anne; Walker, Nadia

    2015-01-01

    The following is a report on an investigation into ways of supporting teachers in converting challenging mathematics tasks into classroom lessons and supporting students in engaging with those tasks. Groups of primary and secondary teachers, respectively, were provided with documentation of ten lessons built around challenging tasks. Teachers…

  16. Task Engagement: A Turning Point in Foreign Language Development.

    Science.gov (United States)

    Platt, Elizabeth J.; Brooks, Frank B.

    2002-01-01

    Uses a sociocultural framework to suggest task engagement as a viable construct in second language learning research. Examines second language learner data to identify task engagement as it emerges, unfolds in dialogic activity, and becomes associated with he transformation of task, self, and group. (Author/VWL)

  17. Small Group Inquiry.

    Science.gov (United States)

    Koller, Martin M.

    Learning in small groups is a practical way to bring about behavior change. The inquiry learning process is perceived to be the most natural and scientific way of learning. Skills developed include those of problem-solving task analysis, decision-making, value formation and adaptability. The art of small group interaction is developed. Factual…

  18. Fuel oil quality task force

    Energy Technology Data Exchange (ETDEWEB)

    Laisy, J.; Turk, V. [R.W. Beckett Corp., Elyria, OH (United States)

    1997-09-01

    In April, 1996, the R.W. Beckett Corporation became aware of a series of apparently unrelated symptoms that made the leadership of the company concerned that there could be a fuel oil quality problem. A task force of company employees and industry consultants was convened to address the topic of current No. 2 heating oil quality and its effect on burner performance. The task force studied changes in fuel oil specifications and trends in properties that have occurred over the past few years. Experiments were performed at Beckett and Brookhaven National Laboratory to understand the effect of changes in some fuel oil properties. Studies by other groups were reviewed, and field installations were inspected to gain information about the performance of fuel oil that is currently being used in the U.S. and Canada. There was a special concern about the use of red dye in heating oils and the impact of sulfur levels due to the October, 1993 requirement of low sulfur (<0.05%) for on-highway diesel fuel. The results of the task force`s efforts were published in July, 1996. The primary conclusion of the task force was that there is not a crisis or widespread general problem with fuel oil quality. Localized problems that were seen may have been related to refinery practices and/or non-traditional fuel sources. System cleanliness is very important and the cause of many oil burner system problems. Finally, heating oil quality should get ongoing careful attention by Beckett engineering personnel and heating oil industry groups.

  19. Testing the Automatization Deficit Hypothesis of Dyslexia via a Dual-Task Paradigm.

    Science.gov (United States)

    Yap, Regina L.; van der Leij, Aryan

    1994-01-01

    Fourteen Dutch children with dyslexia were compared with controls on automatic processing under a dual task (motor balance task and auditory choice task) model. Results indicated the dyslexic group was more impaired in the dual task condition than in the single task condition, compared with controls. Findings support the automatization deficit…

  20. Is Distributed Cognition Group Level Cognition?

    Directory of Open Access Journals (Sweden)

    Ludwig Kirk

    2015-09-01

    Full Text Available This paper shows that recent arguments from group problem solving and task performance to emergent group level cognition that rest on the social parity and related principles are invalid or question begging. The paper shows that standard attributions of problem solving or task performance to groups require only multiple agents of the outcome, not a group agent over and above its members, whether or not any individual member of the group could have accomplished the task independently.

  1. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lighting – Lighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...

  2. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    Civil servants conduct the work which makes welfare states functions on an everyday bases: Police men police, school teachers teach, and tax inspectors inspect. Focus in this paper is on the core tasks of tax inspectors. The paper argues that their core task of securing the collection of revenue...... has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  3. [The effect of reading tasks on learning from multiple texts].

    Science.gov (United States)

    Kobayashi, Keiichi

    2014-06-01

    This study examined the effect of reading tasks on the integration of content and source information from multiple texts. Undergraduate students (N = 102) read five newspaper articles about a fictitious incident in either a summarization task condition or an evaluation task condition. Then, they performed an integration test and a source choice test, which assessed their understanding of a situation described in the texts and memory for the sources of text information. The results indicated that the summarization and evaluation task groups were not significantly different in situational understanding. However, the summarization task group significantly surpassed the evaluation task group for source memory. No significant correlation between the situational understanding and the source memory was found for the summarization group, whereas a significant positive correlation was found for the evaluation group. The results are discussed in terms of the documents model framework.

  4. Classroom Interactions in a Cooperative Translation Task

    Directory of Open Access Journals (Sweden)

    Hui chuan Wang

    2013-03-01

    Full Text Available For the past decade, translation learning has become one of the main foci for university language students in Taiwan. However, many studies have shown that translation teachers tend to adopt traditional teaching methods without considering class dynamics and student interactions. This paper therefore looks into the interactions in the researcher’s designed cooperative translation task, the Cooperative Translation Task, to see how these interactions helped or hindered students’ translation learning. A small class of 25 translation students and two translation teachers were participants. Videotaping and interviews were conducted in order to investigate the interaction modes and student participants’ perspectives toward each interaction mode. Six interaction modes were found in this task: within group, between group, translator group and comment-giver group, instructor and students, guest teacher and students, and instructor and guest teacher. Based on the results and participants’ responses, suggested teaching guidelines are provided.

  5. Effects of Variations in Task Design on Mathematics Teachers' Learning Experiences: A Case of a Sorting Task

    Science.gov (United States)

    Koichu, Boris; Zaslavsky, Orit; Dolev, Lea

    2016-01-01

    The goal of the study presented in this article was to examine how variations in task design may affect mathematics teachers' learning experiences. The study focuses on sorting tasks, i.e., learning tasks that require grouping a given set of mathematical items, in as many ways as possible, according to different criteria suggested by the learners.…

  6. Influences of parameter uncertainties within the ICRP-66 respiratory tract model: regional tissue doses for 239PuO2 and 238UO2/238U3O8.

    Science.gov (United States)

    Farfán, Eduardo B; Huston, Thomas E; Bolch, W Emmett; Vernetson, William G; Bolch, Wesley E

    2003-04-01

    This paper extends an examination of the influence of parameter uncertainties on regional doses to respiratory tract tissues for short-ranged alpha particles using the ICRP-66 respiratory tract model. Previous papers examined uncertainties in the deposition and clearance aspects of the model. The critical parameters examined in this study included target tissue depths, thicknesses, and masses, particularly within the thoracic or lung regions of the respiratory tract. Probability density functions were assigned for the parameters based on published data. The probabilistic computer code LUDUC (Lung Dose Uncertainty Code) was used to assess regional and total lung doses from inhaled aerosols of 239PuO2 and 238UO2/238U3O8. Dose uncertainty was noted to depend on the particle aerodynamic diameter. Additionally, dose distributions were found to follow a lognormal distribution pattern. For 239PuO2 and 238UO2/238U3O8, this study showed that the uncertainty in lung dose increases by factors of approximately 50 and approximately 70 for plutonium and uranium oxides, respectively, over the particle size range from 0.1 to 20 microm. For typical exposure scenarios involving both radionuclides, the ratio of the 95% dose fractile to the 5% dose fractile ranged from approximately 8-10 (corresponding to a geometric standard deviation, or GSD, of about 1.7-2) for particle diameters of 0.1 to 1 microm. This ratio increased to about 370 for plutonium oxide (GSD approximately 4.5) and to about 600 for uranium oxide (GSD approximately 5) as the particle diameter approached 20 microm. However, thoracic tissue doses were quite low at larger particle sizes because most of the deposition occurred in the extrathoracic airways. For 239PuO2, median doses from LUDUC were found be in general agreement with those for Reference Man (via deterministic LUDEP 2.0 calculations) in the particle range of 0.1 to 5 microm. However, median doses to the basal cell nuclei of the bronchial airways (BB

  7. Dual task performance in normal aging: a comparison of choice reaction time tasks.

    Directory of Open Access Journals (Sweden)

    Eleftheria Vaportzis

    Full Text Available This study examined dual task performance in 28 younger (18-30 years and 28 older (>60 years adults using two sets of choice reaction time (RT tasks paired with digit tasks. Set one paired simple choice RT with digit forward; set two paired complex choice RT with digit backward. Each task within each set had easy and hard conditions. For the simple choice RT, participants viewed single letters and pressed a specified keyboard key if the letter was X or Z or a different key for other letters (easy. For the hard condition, there were 4 target letters (X, Z, O, Y. Digit forward consisted of 4 (easy or 5 (hard digits. For the complex choice RT, participants viewed 4×4 matrices of Xs and Os, and indicated whether four Xs (easy or four Xs or four Os (hard appeared in a row. Digit backward consisted of 3 (easy or 4 (hard digits. Within each set, participants performed every possible combination of tasks. We found that in the simple choice RT tasks older adults were significantly slower than, but as accurate as younger adults. In the complex choice RT tasks, older adults were significantly less accurate, but as fast as younger adults. For both age groups and both dual task sets, RT decreased and error rates increased with greater task difficulty. Older adults had greater dual task costs for error rates in the simple choice RT, whereas in the complex choice RT, it was the younger group that had greater dual task costs. Findings suggest that younger and older adults may adopt differential behavioral strategies depending on complexity and difficulty of dual tasks.

  8. Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

    Science.gov (United States)

    Lien, Mei-Ching; Ruthruff, Eric

    2004-01-01

    This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

  9. Group Problem Solving

    CERN Document Server

    Laughlin, Patrick R

    2011-01-01

    Experimental research by social and cognitive psychologists has established that cooperative groups solve a wide range of problems better than individuals. Cooperative problem solving groups of scientific researchers, auditors, financial analysts, air crash investigators, and forensic art experts are increasingly important in our complex and interdependent society. This comprehensive textbook--the first of its kind in decades--presents important theories and experimental research about group problem solving. The book focuses on tasks that have demonstrably correct solutions within mathematical

  10. Affordances and synchronization in collective creative construction tasks

    DEFF Research Database (Denmark)

    Tylén, Kristian; Fusaroli, Riccardo

    to the affordances of the task at hand. We also show that during collective, but not individual tasks, within group synchronization grows over time. Finally, we discuss how these measures of synchronization relate to the participants’ engagement in the tasks at hand and to the end products (LEGO models......: the affordances of the task at hand and the gradual consolidation of collaborative practices. Six groups of participants were instructed to construct LEGO models of six abstract notions (“responsibility”, “knowledge”, “justice” etc.), both individually and in groups. We combine video analysis and heart rate...... measurements and employ recurrence analysis techniques to quantify the mutual adaptability of heart rates among the participants in the different tasks. We show that during individual tasks individual heart rates synchronize both within and between groups (but not with controls) plausibly due...

  11. Motor skill experience modulates executive control for task switching.

    Science.gov (United States)

    Yu, Qiuhua; Chan, Chetwyn C H; Chau, Bolton; Fu, Amy S N

    2017-09-15

    This study aimed to investigate the effect of types of motor skills, including open and closed skills on enhancing proactive and reactive controls for task switching. Thirty-six athletes in open (n=18) or closed (n=18) sports and a control group (n=18) completed the task-switching paradigm and the simple reaction task. The task-switching paradigm drew on the proactive and reactive control of executive functions, whereas the simple reaction task assessed the processing speed. Significant Validity×Group effect revealed that the participants with open skills had a lower switch cost of response time compared to the other two groups when the task cue was 100% valid; whereas the participants regardless of motor skills had a lower switch cost of response time compared to the control group when the task cue was 50% valid. Hierarchical stepwise regression analysis further confirmed these findings. For the simple reaction task, there were no differences found among the three groups. These findings suggest that experience in open skills has benefits of promoting both proactive and reactive controls for task switching, which corresponds to the activity context exposed by the participants. In contrast, experience in closed skills appears to only benefit development of reactive control for task switching. The neural mechanisms for the proactive and reactive controls of executive functions between experts with open and closed skills call for future study. Copyright © 2017. Published by Elsevier B.V.

  12. The current status of diabetes professional educational standards and competencies in the UK--a position statement from the Diabetes UK Healthcare Professional Education Competency Framework Task and Finish Group.

    Science.gov (United States)

    Walsh, N; George, S; Priest, L; Deakin, T; Vanterpool, G; Karet, B; Simmons, D

    2011-12-01

    Diabetes is a significant health concern, both in the UK and globally. Management can be complex, often requiring high levels of knowledge and skills in order to provide high-quality and safe care. The provision of good, safe, quality care lies within the foundations of healthcare education, continuing professional development and evidence-based practice, which are inseparable and part of a continuum during the career of any health professional. Sound education provides the launch pad for effective clinical management and positive patient experiences. This position paper reviews and discusses work undertaken by a Working Group under the auspices of Diabetes UK with the remit of considering all health professional educational issues for people delivering care to people with diabetes. This work has scoped the availability of education for those within the healthcare system who may directly or indirectly encounter people with diabetes and reviews alignment to existing competency frameworks within the UK's National Health Service.

  13. Board Task Performance

    DEFF Research Database (Denmark)

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

    2012-01-01

    This paper addresses recent calls to narrow the micro–macro gap in management research (Bamberger, 2008), by incorporating a macro-level context variable (country) in exploring micro-level determinants of board effectiveness. Following the integrated model proposed by Forbes and Milliken (1999), we...... identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings...... influence board tasks, and how the context moderates the relationship between processes and tasks. Our hypotheses are tested on a survey-based dataset of 535 medium-sized and large industrial firms in Italy and Norway, which are considered to substantially differ along legal and cultural dimensions...

  14. Goal orientation, perceived task outcome and task demands in mathematics tasks: effects on students' attitude in actual task settings.

    Science.gov (United States)

    Seegers, Gerard; van Putten, Cornelis M; de Brabander, Cornelis J

    2002-09-01

    In earlier studies, it has been found that students' domain-specific cognitions and personal learning goals (goal orientation) influence task-specific appraisals of actual learning tasks. The relations between domain-specific and task-specific variables have been specified in the model of adaptive learning. In this study, additional influences, i.e., perceived task outcome on a former occasion and variations in task demands, were investigated. The purpose of this study was to identify personality and situational variables that mediate students' attitude when confronted with a mathematics task. Students worked on a mathematics task in two subsequent sessions. Effects of perceived task outcome at the first session on students' attitude at the second session were investigated. In addition, we investigated how differences in task demands influenced students' attitude. Variations in task demands were provoked by different conditions in task-instruction. In one condition, students were told that the result on the test would add to their mark on mathematics. This outcome orienting condition was contrasted with a task-orienting condition where students were told that the results on the test would not be used to give individual grades. Participants were sixth grade students (N = 345; aged 11-12 years) from 14 primary schools. Multivariate and univariate analyses of (co)variance were applied to the data. Independent variables were goal orientation, task demands, and perceived task outcome, with task-specific variables (estimated competence for the task, task attraction, task relevance, and willingness to invest effort) as the dependent variables. The results showed that previous perceived task outcome had a substantial impact on students' attitude. Additional but smaller effects were found for variation in task demands. Furthermore, effects of previous perceived task outcome and task demands were related to goal orientation. The resulting pattern confirmed that, in general

  15. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  16. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 3-5, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  17. Task-Based Learning: The Interaction between Tasks and Learners.

    Science.gov (United States)

    Murphy, Jacky

    2003-01-01

    Investigates the relationship between tasks and learners in task-based learning. Findings suggest that manipulation of task characteristics and conditions may not achieve the intended pedagogic outcomes, and that new ways are needed to focus learners' attention of form without sacrificing the meaning-driven principles of task-based learning.…

  18. Characterization of task-free and task-performance brain states via functional connectome patterns.

    Science.gov (United States)

    Zhang, Xin; Guo, Lei; Li, Xiang; Zhang, Tuo; Zhu, Dajiang; Li, Kaiming; Chen, Hanbo; Lv, Jinglei; Jin, Changfeng; Zhao, Qun; Li, Lingjiang; Liu, Tianming

    2013-12-01

    Both resting state fMRI (R-fMRI) and task-based fMRI (T-fMRI) have been widely used to study the functional activities of the human brain during task-free and task-performance periods, respectively. However, due to the difficulty in strictly controlling the participating subject's mental status and their cognitive behaviors during R-fMRI/T-fMRI scans, it has been challenging to ascertain whether or not an R-fMRI/T-fMRI scan truly reflects the participant's functional brain states during task-free/task-performance periods. This paper presents a novel computational approach to characterizing and differentiating the brain's functional status into task-free or task-performance states, by which the functional brain activities can be effectively understood and differentiated. Briefly, the brain's functional state is represented by a whole-brain quasi-stable connectome pattern (WQCP) of R-fMRI or T-fMRI data based on 358 consistent cortical landmarks across individuals, and then an effective sparse representation method was applied to learn the atomic connectome patterns (ACPs) of both task-free and task-performance states. Experimental results demonstrated that the learned ACPs for R-fMRI and T-fMRI datasets are substantially different, as expected. A certain portion of ACPs from R-fMRI and T-fMRI data were overlapped, suggesting some subjects with overlapping ACPs were not in the expected task-free/task-performance brain states. Besides, potential outliers in the T-fMRI dataset were further investigated via functional activation detections in different groups, and our results revealed unexpected task-performances of some subjects. This work offers novel insights into the functional architectures of the brain.

  19. A Daunting Task Still

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2010-01-01

    @@ Despite steady economic growth for three decades, China is still a developing country facing daunting poverty alleviation tasks. According to the poverty line of 1,196 yuan ($176) per capita net income in a year set in March 2009, the country still has a poverty population of more than 40 million, mainly living in rural areas.

  20. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  1. Can tasks be inherently boring?

    Science.gov (United States)

    Charney, Evan

    2013-12-01

    Kurzban et al. argue that the experiences of "effort," "boredom," and "fatigue" are indications that the costs of a task outweigh its benefits. Reducing the costs of tasks to "opportunity costs" has the effect of rendering tasks costless and of denying that they can be inherently boring or tedious, something that "vigilance tasks" were intentionally designed to be.

  2. Set shifting training with categorization tasks.

    Directory of Open Access Journals (Sweden)

    Anna Soveri

    Full Text Available The very few cognitive training studies targeting an important executive function, set shifting, have reported performance improvements that also generalized to untrained tasks. The present randomized controlled trial extends set shifting training research by comparing previously used cued training with uncued training. A computerized adaptation of the Wisconsin Card Sorting Test was utilized as the training task in a pretest-posttest experimental design involving three groups of university students. One group received uncued training (n = 14, another received cued training (n = 14 and the control group (n = 14 only participated in pre- and posttests. The uncued training group showed posttraining performance increases on their training task, but neither training group showed statistically significant transfer effects. Nevertheless, comparison of effect sizes for transfer effects indicated that our results did not differ significantly from the previous studies. Our results suggest that the cognitive effects of computerized set shifting training are mostly task-specific, and would preclude any robust generalization effects with this training.

  3. ACC/AHA Special Report: Clinical Practice Guideline Implementation Strategies: A Summary of Systematic Reviews by the NHLBI Implementation Science Work Group: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.

    Science.gov (United States)

    Chan, Wiley V; Pearson, Thomas A; Bennett, Glen C; Cushman, William C; Gaziano, Thomas A; Gorman, Paul N; Handler, Joel; Krumholz, Harlan M; Kushner, Robert F; MacKenzie, Thomas D; Sacco, Ralph L; Smith, Sidney C; Stevens, Victor J; Wells, Barbara L; Castillo, Graciela; Heil, Susan K R; Stephens, Jennifer; Vann, Julie C Jacobson

    2017-02-28

    In 2008, the National Heart, Lung, and Blood Institute convened an Implementation Science Work Group to assess evidence-based strategies for effectively implementing clinical practice guidelines. This was part of a larger effort to update existing clinical practice guidelines on cholesterol, blood pressure, and overweight/obesity. Review evidence from the published implementation science literature and identify effective or promising strategies to enhance the adoption and implementation of clinical practice guidelines. This systematic review was conducted on 4 critical questions, each focusing on the adoption and effectiveness of 4 intervention strategies: (1) reminders, (2) educational outreach visits, (3) audit and feedback, and (4) provider incentives. A scoping review of the Rx for Change database of systematic reviews was used to identify promising guideline implementation interventions aimed at providers. Inclusion and exclusion criteria were developed a priori for each question, and the published literature was initially searched up to 2012, and then updated with a supplemental search to 2015. Two independent reviewers screened the returned citations to identify relevant reviews and rated the quality of each included review. Audit and feedback and educational outreach visits were generally effective in improving both process of care (15 of 21 reviews and 12 of 13 reviews, respectively) and clinical outcomes (7 of 12 reviews and 3 of 5 reviews, respectively). Provider incentives showed mixed effectiveness for improving both process of care (3 of 4 reviews) and clinical outcomes (3 reviews equally distributed between generally effective, mixed, and generally ineffective). Reminders showed mixed effectiveness for improving process of care outcomes (27 reviews with 11 mixed and 3 generally ineffective results) and were generally ineffective for clinical outcomes (18 reviews with 6 mixed and 9 generally ineffective results). Educational outreach visits (2 of 2

  4. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    . Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do......In the paper, we deal with how to organize work for cross-professional knowledge sharing. We do so inspired by relational coordination theory, which is affiliated with positive organizational scholarship. Relational coordination theory is constituted by a combination of relationships marked...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  5. Community hoarding task forces: a comparative case study of five task forces in the United States.

    Science.gov (United States)

    Bratiotis, Christiana

    2013-05-01

    During the past decade, many community task forces have formed to address hoarding problems that come to public attention. Such task forces provide a societal-level intervention to assist people with the most severe cases of hoarding, who do not voluntarily seek or want help for their hoarding behaviour. This qualitative study of five U.S. hoarding task forces included sites selected for their diversity of purpose, approaches to hoarding intervention and community geography, composition and resources. Data were collected during the period of September 2007-March 2008. The case study methodology used multiple forms of data, including semi-structured interviews, analysis of documents, small group interviews and investigator observation. This study captured the perspectives of public and private sector service providers such as mental health, housing, social service, public health agencies and community enforcement organisations (fire, police, legal, animal control) to examine how task forces organise and operate and the emerging practice and policy changes. Study findings suggest that structural factors (e.g. leadership, purpose, funding and membership) impact hoarding task force viability, that participation on a task force influences practice and policy decisions about hoarding, and that social work can expand its role in task force leadership. Task forces may be a mechanism for improving community policies about hoarding and mechanisms for addressing other social problems across multiple sectors.

  6. Features or tasks?

    DEFF Research Database (Denmark)

    Heilesen, Simon

    In this paper for the Workshop on Human-computer interaction and e-learning, NordiCHI 2002, the author argues that in developing innovative E-learning systems, especially if constructivist pedagogy is to be applied, it will be useful to model the user interface on the often complex tasks...... that the user has to perform rather than just focusing on technical features (and adapting system use to them)....

  7. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  8. Estimation of specific absorbed fractions for selected organs due to photons emitted by activity deposited in the human respiratory tract using ICRP/ICRU male voxel phantom in FLUKA.

    Science.gov (United States)

    Patni, H K; Akar, D K; Nadar, M Y; Ghare, V P; Rao, D D; Sarkar, P K

    2013-01-01

    The ICRP/ICRU adult male reference voxel phantom incorporated in Monte Carlo code FLUKA is used for estimating specific absorbed fractions (SAFs) for photons due to the presence of internal radioactive contamination in the human respiratory tract (RT). The compartments of the RT, i.e. extrathoracic (ET1 and ET2) and thoracic (bronchi, bronchioles, alveolar interstitial) regions, lymph nodes of both regions and lungs are considered as the source organs. The nine organs having high tissue weighting factors such as colon, lungs, stomach wall, breast, testis, urinary bladder, oesophagus, liver and thyroid and the compartments of the RT are considered as target organs. Eleven photon energies in the range of 15 keV to 4 MeV are considered for each source organ and the computed SAF values are presented in the form of tables. For the target organs in the proximity of the source organ including the source organ itself, the SAF values are relatively higher and decrease with increase in energy. As the distance between source and target organ increases, SAF values increase with energy and reach maxima depending on the position of the target organ with respect to the source organ. The SAF values are relatively higher for the target organs with smaller masses. Large deviations are seen in computed SAF values from the existing MIRD phantom data for most of the organs. These estimated SAF values play an important role in the estimation of equivalent dose to various target organs of a worker due to intake by inhalation pathway.

  9. A Comparative Study of Task-based vs. Task- supported Teaching Approaches in an EFL Context

    Directory of Open Access Journals (Sweden)

    Mahdieh Shafipoor

    2015-09-01

    Full Text Available In spite of the numerous merits of task-based language instruction as claimed by its supporters in the last few decades, task-supported teaching approach as an alternative was introduced. Since then, there have been controversial debates over the superiority of each of these two approaches. Thus, in the current research project, the purpose was to consider these two teaching approaches in the scope of English language teaching, with the purpose of exploring the most efficient one in an Iranian EFL context. To this end, 120 sophomore students, majoring in English language translation course at Islamic Azad University, Shar-e-Qods branch were selected among 4 intact reading comprehension II classes. Next, they were divided into two experimental groups. The first experimental group received task-based instruction and for the second experimental group, task-trusted teaching approach was applied. The results of the data analyses turned out that task-trusted teaching approach was superior to task-based teaching in teaching reading to EFL learners.

  10. Effects of Gait and Cognitive Task Difficulty on Cognitive-Motor Interference in Aging

    Directory of Open Access Journals (Sweden)

    Prudence Plummer-D'Amato

    2012-01-01

    Full Text Available Although gait-related dual-task interference in aging is well established, the effect of gait and cognitive task difficulty on dual-task interference is poorly understood. The purpose of this study was to examine the effect of gait and cognitive task difficulty on cognitive-motor interference in aging. Fifteen older adults (72.1 years, SD 5.2 and 20 young adults (21.7 years, SD 1.6 performed three walking tasks of varying difficulty (self-selected speed, fast speed, and fast speed with obstacle crossing under single- and dual-task conditions. The cognitive tasks were the auditory Stroop task and the clock task. There was a significant Group × Gait Task × Cognitive Task interaction for the dual-task effect on gait speed. After adjusting for education, there were no significant effects of gait or cognitive task difficulty on the dual-task effects on cognitive task performance. The results of this study provide evidence that gait task difficulty influences dual-task effects on gait speed, especially in older adults. Moreover, the effects of gait task difficulty on dual-task interference appear to be influenced by the difficulty of the cognitive task. Education is an important factor influencing cognitive-motor interference effects on cognition, but not gait.

  11. Report of the heavy-ion fusion task group

    Energy Technology Data Exchange (ETDEWEB)

    Sawyer, G.A.; Booth, L.A.; Henderson, D.B.; Jameson, R.A.; Kindel, J.M.; Knapp, E.A.; Pollock, R.; Talbert, W.L.; Thode, L.E.; Williams, J.M.

    1980-02-01

    An assessment of heavy-ion fusion has been completed. Energetic heavy ions, for example 10-GeV uranium, provided by an rf linac or an induction linac, are used as alternatives to laser light to drive inertial confinement fusion pellets. The assessment has covered accelerator technology, transport of heavy-ion beams, target interaction physics, civilian power issues, and military applications. It is concluded that particle accelerators promise to be efficient pellet drivers, but that there are formidable technical problems to be solved. It is recommended that a moderate level research program on heavy-ion fusion be pursued and that LASL should continue to work on critical issues in accelerator development, beam transport, reactor systems studies, and target physics over the next few years.

  12. Task Group on Strengthening the DoD Enterprise Governance

    Science.gov (United States)

    2008-07-01

    studies and academic publications, including: – Business Roundtable, Principles of Corporate Governance (2005) – McKinsey Quarterly, Organizing for...could be made in the Department’s corporate governance based upon the above observations? Other: 14. Are there any other people that have

  13. Peer support in small group EFL writing tasks

    Directory of Open Access Journals (Sweden)

    JESÚS DAVID GUERRA LYONS

    2016-01-01

    Full Text Available Este artículo se basa en una investigación de aula enfocada en la temática del apoyo en tareas de escritura en grupos pequeños al interior de un curso de inglés como lengua extranjera. Se buscó analizar la forma como los aprendices estructuran distintas formas de apoyo según su conciencia intersubjetiva de las necesidades y objetivos de sus pares, las cuales fueron comparadas con las ofrecidas por el docente con el fin de identificar similitudes y contrastes. Se encontró que los aprendices ofrecen al menos tres tipos de apoyo: cognitivo, estratégico y evaluativo. En cada uno de ellos se encontraron dinámicas intersubjetivas particulares a medida que los aprendices interpretaban las necesidades y objetivos que surgían durante la tarea. Se observó que el apoyo del docente fue principalmente estratégico, es decir, orientado al desarrollo de la tarea. Además, se observa que el apoyo del docente a menudo no corresponde con las necesidades de los aprendices debido a una falta de espacios para el establecimiento de terreno intersubjetivo común. Al final se discuten implicaciones pedagógicas e investigativas de estos hallazgos.

  14. Unique Signal mathematical analysis task group FY03 status report.

    Energy Technology Data Exchange (ETDEWEB)

    Baty, Roy Stuart (Los Alamos National Laboratory, Los Alamos, NM); Johnston, Anna Marie; Hart, Elizabeth (Utah State University, Logan, UT); White, Allan (NASA, Langley Research Center, Hampton, VA); Cooper, James Arlin

    2003-12-01

    The Unique Signal is a key constituent of Enhanced Nuclear Detonation Safety (ENDS). Although the Unique Signal approach is well prescribed and mathematically assured, there are numerous unsolved mathematical problems that could help assess the risk of deviations from the ideal approach. Some of the mathematics-based results shown in this report are: 1. The risk that two patterns with poor characteristics (easily generated by inadvertent processes) could be combined through exclusive-or mixing to generate an actual Unique Signal pattern has been investigated and found to be minimal (not significant when compared to the incompatibility metric of actual Unique Signal patterns used in nuclear weapons). 2. The risk of generating actual Unique Signal patterns with linear feedback shift registers is minimal, but the patterns in use are not as invulnerable to inadvertent generation by dependent processes as previously thought. 3. New methods of testing pair-wise incompatibility threats have resulted in no significant problems found for the set of Unique Signal patterns currently used. Any new patterns introduced would have to be carefully assessed for compatibility with existing patterns, since some new patterns under consideration were found to be deficient when associated with other patterns in use. 4. Markov models were shown to correspond to some of the engineered properties of Unique Signal sequences. This gives new support for the original design objectives. 5. Potential dependence among events (caused by a variety of communication protocols) has been studied. New evidence has been derived of the risk associated with combined communication of multiple events, and of the improvement in abnormal-environment safety that can be achieved through separate-event communication.

  15. Multicultural Leader Behaviors in Ethnically Mixed Task Groups.

    Science.gov (United States)

    1980-03-15

    Deficit, difference, and bicultural models of Afro-American behavior. Harvard Educational Review, 1971, 41, (2), 137-157. Vasconcellos, J. La raza ...cosmica (4th ed.). Mexico, D.F.: Espasa-Calpe Mexicana, S. A., 1976. Zea, L. Dependencia y liberacion en la cultura latinoamericana. Mexico, D.F

  16. Task Dynamics in a College Biology Course for Prospective Elementary Teachers.

    Science.gov (United States)

    Moscovici, Hedy

    2001-01-01

    Explores the dynamic profile of a task as interpreted by a group of six prospective elementary teachers enrolled in a college biology course. Describes the shift from a planned task to a transitional task and finally an enacted task. (Author/MM)

  17. Task Dynamics in a College Biology Course for Prospective Elementary Teachers.

    Science.gov (United States)

    Moscovici, Hedy

    2001-01-01

    Explores the dynamic profile of a task as interpreted by a group of six prospective elementary teachers enrolled in a college biology course. Describes the shift from a planned task to a transitional task and finally an enacted task. (Author/MM)

  18. Task Dominance Determines Backward Inhibition in Task Switching

    Directory of Open Access Journals (Sweden)

    Kerstin Jost

    2017-05-01

    Full Text Available Switching between tasks is assumed to be accompanied by inhibiting currently irrelevant, but competing tasks. A dominant task that strongly interferes with performing a weaker task may receive especially strong inhibition. We tested this prediction by letting participants switch among three tasks that differ in dominance: a location discrimination task with strong stimulus–response bindings (responding with left-hand and right-hand button presses to stimuli presented left or right to the fixation cross was combined with a color/pattern and a shape discrimination task, for which stimulus–response mappings were arbitrary (e.g., left-hand button press mapped to a red stimulus. Across three experiments, the dominance of the location task was documented by faster and more accurate responses than in the other tasks. This even held for incompatible stimulus–response mappings (i.e., right-hand response to a left-presented stimulus and vice versa, indicating that set-level compatibility (i.e., “dimension overlap” was sufficient for making this location task dominant. As a behavioral marker for backward inhibition, we utilized n-2 repetition costs that are defined by higher reaction times for a switch back to a just abandoned and thus just inhibited task (ABA sequence than for a switch to a less recently inhibited task (CBA, n-2 non-repetition. Reliable n-2 task repetition costs were obtained for all three tasks. Importantly, these costs were largest for the location task, suggesting that inhibition indeed was stronger for the dominant task. This finding adds to other evidence that the amount of inhibition is adjusted in a context-sensitive way.

  19. The Variety of Group Learning

    Institute of Scientific and Technical Information of China (English)

    HaoYanyan; YuZhihao

    2004-01-01

    With the rapid enrollment expansion in the recent years,the author feels it urgent to reform the traditional group work,and therefore to form a new and more effective pattern of group learning. The new of group word is based on the principles of cooperation and that of the task with the more flexible marking system.

  20. The Impact of Task Complexity and Strategic Planning Time on EFL Learners’ Accuracy and Fluency in Written Task Production

    Directory of Open Access Journals (Sweden)

    Asghar Salimi

    2012-11-01

    Full Text Available The past twenty years has witnessed a remarkable increase in the number of studies investigating different aspects and features of tasks in the second and foreign language class and their effects on learners’ oral and written task performance. Building up on a review of the studies conducted in the field of task-based language teaching a gap was revealed in the literature on the joint effects of task complexity and types of pre-task planning on L2 learners’ performance. The present study investigates the effects of strategic pre-task planning time and task complexity on a group of L2 learners’ written performance in terms of accuracy and fluency. The means of accuracy and fluency of 50 intermediate English language learners, both male and female, chosen randomly from Iran National Language Institute, Miandoab Branch were compared using T-test as the statistical means of analysis. The findings revealed a positive influence of pre-task strategic planning time in both simple and complex tasks, suggesting significant implications for syllabus and task designers, language teachers, and SLA researchers. Keywords: Task-based language teaching, Planning time, Strategic planning, Task complexity, Accuracy, Fluency

  1. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  2. Impact of reduced dose limits on NRC licensed activities. Major issues in the implementation of ICRP/NCRP dose limit recommendations: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meinhold, C.B. [Brookhaven National Lab., Upton, NY (United States)

    1995-05-01

    This report summarizes information required to estimate, at least qualitatively, the potential impacts of reducing occupational dose limits below those given in 10 CFR 20 (Revised). For this study, a questionnaire was developed and widely distributed to the radiation protection community. The resulting data together with data from existing surveys and sources were used to estimate the impact of three dose-limit options; 10 mSv yr{sup {minus}1} (1 rem yr{sup {minus}1}), 20 mSv yr{sup {minus}1} (2 rem yr{sup {minus}1}), and a combination of an annual limit of 50 mSv yr{sup {minus}1} (5 rem yr{sup {minus}1}) coupled with a cumulative limit, in rem, equal to age in years. Due to the somewhat small number of responses and the lack of data in some specific areas, a working committee of radiation protection experts from a variety of licensees was employed to ensure the exposure data were representative. The following overall conclusions were reached: (1) although 10 mSv yr{sup {minus}1} is a reasonable limit for many licensees, such a limit could be extraordinarily difficult to achieve and potentially destructive to the continued operation of some licensees, such as nuclear power, fuel fabrication, and medicine; (2) twenty mSv yr{sup {minus}1} as a limit is possible for some of these groups, but for others it would prove difficult. (3) fifty mSv yr{sup {minus}1} and age in 10s of mSv appear reasonable for all licensees, both in terms of the lifetime risk of cancer and severe genetic effects to the most highly exposed workers, and the practicality of operation.

  3. Plasticity of executive control through task switching training in adolescents

    Directory of Open Access Journals (Sweden)

    Katharina eZinke

    2012-03-01

    Full Text Available Research has shown that cognitive training can enhance performance in executive control tasks. Current study was designed to explore whether executive control can also be trained in adolescents, what particular aspects of executive control may underlie training and transfer effects, and whether acute bouts of exercise directly prior to cognitive training enhance training effects. For that purpose, a task switching training was employed that has been shown to be effective in other age groups. A group of adolescents (10-14 years, n = 20 that received a three-week TS training was compared to a group (n = 20 that received the same TS training but who exercised on a stationary bike before each training session. Additionally, a no-contact and an exercise-only control group were included (both ns = 20. Analyses indicated that both training groups significantly reduced their switching costs over the course of the training sessions and also reduced their mixing costs in a near transfer task. The reduction in mixing costs in the near transfer task was larger in the trained groups than in the non-trained control groups. Far transfer of cognitive training was limited to a choice reaction time task and a tendency for faster reaction times in an updating task. Findings indicate that executive control can be enhanced in adolescents through training and that updating may be of particular relevance for the effects of task switching training.

  4. Calorimetry Task Force Report

    CERN Document Server

    Abdullin, Salavat; Banerjee, Sunanda; Beauceron, Stephanie; Beaudette, Florian; Bhatti, Anwar; Chlebana, Frank; Cossutti, Fabio; Hirschauer, James; Ivanchenko, V; Jang, Dong Wook; Jun, Soon Yung; Kunori, Shuichi; Kroeger, Rob; Liu, Yanwen; Moeller, Anthony; Paulini, Manfred; Piperov, Stefan; Rahmat, Rahmat; Rovelli, Chiara; Safronov, Grigory; Sharma, Seema; Spiropulu, Maria; Yetkin, Taylan

    2010-01-01

    In this note we summarize the progress made by the calorimeter simulation task force (CaloTF) over the past year. The CaloTF was established in February 2008 in order to understand and reconcile the discrepancies observed between the CMS calorimetry simulation and test beam data recorded during 2004 and 2006. The simulation has been significantly improved by using a newer version of Geant4 and an improved physics list for the full CMS detector simulation. Simulation times have been reduced by introducing flexible parameterizations to describe showering in the calorimeter (using a Gflash-like approach) which have been tuned to the test beam data.

  5. Quarternary tectonics, Task 1

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1993-09-30

    Activities conducted for the evaluation of the geology and seismotectonics stability of Yucca Mountain as a potential site for the underground disposal of high-level radioactive wastes continued. Tasks concerned with quaternary tectonics include: scheduling of photography of Little Skull Mountain area; the collection and dating of rock varnish samples from the 1932 Cedar Mountain earthquake area for carbon 14 AMS and cation-ratio analysis; collection of samples for thermoluminescence dating from the 1932 Cedar Mountain earthquake area; mapping of the northern area of Crater Flat; and surveying of the May 17, 1993 Eureka the Valley earthquake area.

  6. On the contingent nature of language‐learning tasks

    OpenAIRE

    Hellermann, John; Pekarek Doehler, Simona

    2013-01-01

    Using methods from conversation analysis, this paper explores ways that teacher‐designed language‐learning task interactions can vary in their performance due to the nature of face‐to‐face interaction. The analysis describes three task interactions from language‐learning classrooms, showing how the contingencies that are necessitated by learners working in small groups provide for different task performance as well as different potentials for language learning. The video‐recorded interactions...

  7. Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.

  8. Social Loafing in a Co-operative Classroom Task.

    Science.gov (United States)

    North, Adrian C.; Linley, P. Alex; Hargreaves, David J.

    2000-01-01

    Investigates whether social loafing (the tendency for individuals to reduce their input when performing as part of a group) existed in a collaborative educational task employing groups of three and eight participants. Indicates that individuals working in smaller groups were more productive than those working in larger groups. (CMK)

  9. Principles of Communicative Task Design.

    Science.gov (United States)

    Nunan, David

    The use of the learning task as a basic planning and instructional tool for communicative second language instruction is discussed, and considerations and procedures for designing such tasks are outlined. A task is defined as a piece of classroom work that involves learners in comprehending, manipulating, producing, or interacting in the target…

  10. TASK: Let's Have a Party!

    Science.gov (United States)

    Rees, James

    2012-01-01

    In this article, the author describes a creative way to demystify contemporary art for students. TASK is artist Oliver Herring's creation, where participants actively interpret instructions found on little pieces of paper--what he calls "tasks." An art classroom has all the key ingredients for a TASK event: (1) people; (2) materials; (3) space;…

  11. TASK: Let's Have a Party!

    Science.gov (United States)

    Rees, James

    2012-01-01

    In this article, the author describes a creative way to demystify contemporary art for students. TASK is artist Oliver Herring's creation, where participants actively interpret instructions found on little pieces of paper--what he calls "tasks." An art classroom has all the key ingredients for a TASK event: (1) people; (2) materials; (3) space;…

  12. Formal language models for finding groups of experts

    NARCIS (Netherlands)

    S. Liang; M. de Rijke

    2016-01-01

    The task of finding groups or teams has recently received increased attention, as a natural and challenging extension of search tasks aimed at retrieving individual entities. We introduce a new group finding task: given a query topic, we try to find knowledgeable groups that have expertise on that t

  13. Modeling Cognitive Strategies during Complex Task Performing Process

    Science.gov (United States)

    Mazman, Sacide Guzin; Altun, Arif

    2012-01-01

    The purpose of this study is to examine individuals' computer based complex task performing processes and strategies in order to determine the reasons of failure by cognitive task analysis method and cued retrospective think aloud with eye movement data. Study group was five senior students from Computer Education and Instructional Technologies…

  14. A Task that Elicits Reasoning: A Dual Analysis

    Science.gov (United States)

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  15. A Task that Elicits Reasoning: A Dual Analysis

    Science.gov (United States)

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  16. Does a Speaking Task Affect Second Language Comprehensibility?

    Science.gov (United States)

    Crowther, Dustin; Trofimovich, Pavel; Isaacs, Talia; Saito, Kazuya

    2015-01-01

    The current study investigated task effects on listener perception of second language (L2) comprehensibility (ease of understanding). Sixty university-level adult speakers of English from 4 first language (L1) backgrounds (Chinese, Romance, Hindi, Farsi), with 15 speakers per group, were recorded performing 2 tasks (IELTS long-turn speaking task…

  17. Validating the Electric Maze Task as a Measure of Planning

    Science.gov (United States)

    Sheppard, Kelly W.; Cheatham, Carol L.

    2017-01-01

    The Electric Maze Task (EMT) is a novel planning task designed to allow flexible testing of planning abilities across a broad age range and to incorporate manipulations to test underlying planning abilities, such as working-memory and inhibitory control skills. The EMT was tested in a group of 63 typically developing 7- to 12-year-olds.…

  18. IEA SHC Task 42/ECES Annex 29 WG A1

    DEFF Research Database (Denmark)

    Ristić, Alenka; Furbo, Simon; Moser, Christoph

    2016-01-01

    An overview on the recent results on the engineering and characterization of sorption materials, PCMs and TCMs investigated in the working group WG A1 “Engineering and processing of TES materials” of IEA SHC Task 42 / ECES Annex 29 (Task 4229) entitled “Compact Thermal Energy Storage” is presented....

  19. Emergent Power Hierarchies and Group Performance.

    Science.gov (United States)

    Frauendorfer, Denise; Schmid Mast, Marianne; Sanchez-Cortes, Dairazalia; Gatica-Perez, Daniel

    2015-10-01

    In newly formed groups, informal hierarchies emerge automatically and readily. In this study, we argue that emergent group hierarchies enhance group performance (Hypothesis 1) and we assume that the more the power hierarchy within a group corresponds to the task-competence differences of the individual group members, the better the group performs (Hypothesis 2). Twelve three-person groups and 28 four-person groups were investigated while solving the Winter Survival Task. Results show that emerging power hierarchies positively impact group performance but the alignment between task-competence and power hierarchy did not affect group performance. Thus, emergent power hierarchies are beneficial for group performance and although they were on average created around individual group members' competence, this correspondence was not a prerequisite for better group performance.

  20. Adaptive group coordination and role differentiation.

    Directory of Open Access Journals (Sweden)

    Michael E Roberts

    Full Text Available Many real world situations (potluck dinners, academic departments, sports teams, corporate divisions, committees, seminar classes, etc. involve actors adjusting their contributions in order to achieve a mutually satisfactory group goal, a win-win result. However, the majority of human group research has involved situations where groups perform poorly because task constraints promote either individual maximization behavior or diffusion of responsibility, and even successful tasks generally involve the propagation of one correct solution through a group. Here we introduce a group task that requires complementary actions among participants in order to reach a shared goal. Without communication, group members submit numbers in an attempt to collectively sum to a randomly selected target number. After receiving group feedback, members adjust their submitted numbers until the target number is reached. For all groups, performance improves with task experience, and group reactivity decreases over rounds. Our empirical results provide evidence for adaptive coordination in human groups, and as the coordination costs increase with group size, large groups adapt through spontaneous role differentiation and self-consistency among members. We suggest several agent-based models with different rules for agent reactions, and we show that the empirical results are best fit by a flexible, adaptive agent strategy in which agents decrease their reactions when the group feedback changes. The task offers a simple experimental platform for studying the general problem of group coordination while maximizing group returns, and we distinguish the task from several games in behavioral game theory.

  1. Lessons Learned from Crowdsourcing Complex Engineering Tasks.

    Science.gov (United States)

    Staffelbach, Matthew; Sempolinski, Peter; Kijewski-Correa, Tracy; Thain, Douglas; Wei, Daniel; Kareem, Ahsan; Madey, Gregory

    2015-01-01

    Crowdsourcing is the practice of obtaining needed ideas, services, or content by requesting contributions from a large group of people. Amazon Mechanical Turk is a web marketplace for crowdsourcing microtasks, such as answering surveys and image tagging. We explored the limits of crowdsourcing by using Mechanical Turk for a more complicated task: analysis and creation of wind simulations. Our investigation examined the feasibility of using crowdsourcing for complex, highly technical tasks. This was done to determine if the benefits of crowdsourcing could be harnessed to accurately and effectively contribute to solving complex real world engineering problems. Of course, untrained crowds cannot be used as a mere substitute for trained expertise. Rather, we sought to understand how crowd workers can be used as a large pool of labor for a preliminary analysis of complex data. We compared the skill of the anonymous crowd workers from Amazon Mechanical Turk with that of civil engineering graduate students, making a first pass at analyzing wind simulation data. For the first phase, we posted analysis questions to Amazon crowd workers and to two groups of civil engineering graduate students. A second phase of our experiment instructed crowd workers and students to create simulations on our Virtual Wind Tunnel website to solve a more complex task. With a sufficiently comprehensive tutorial and compensation similar to typical crowd-sourcing wages, we were able to enlist crowd workers to effectively complete longer, more complex tasks with competence comparable to that of graduate students with more comprehensive, expert-level knowledge. Furthermore, more complex tasks require increased communication with the workers. As tasks become more complex, the employment relationship begins to become more akin to outsourcing than crowdsourcing. Through this investigation, we were able to stretch and explore the limits of crowdsourcing as a tool for solving complex problems.

  2. Lessons Learned from Crowdsourcing Complex Engineering Tasks.

    Directory of Open Access Journals (Sweden)

    Matthew Staffelbach

    Full Text Available Crowdsourcing is the practice of obtaining needed ideas, services, or content by requesting contributions from a large group of people. Amazon Mechanical Turk is a web marketplace for crowdsourcing microtasks, such as answering surveys and image tagging. We explored the limits of crowdsourcing by using Mechanical Turk for a more complicated task: analysis and creation of wind simulations.Our investigation examined the feasibility of using crowdsourcing for complex, highly technical tasks. This was done to determine if the benefits of crowdsourcing could be harnessed to accurately and effectively contribute to solving complex real world engineering problems. Of course, untrained crowds cannot be used as a mere substitute for trained expertise. Rather, we sought to understand how crowd workers can be used as a large pool of labor for a preliminary analysis of complex data.We compared the skill of the anonymous crowd workers from Amazon Mechanical Turk with that of civil engineering graduate students, making a first pass at analyzing wind simulation data. For the first phase, we posted analysis questions to Amazon crowd workers and to two groups of civil engineering graduate students. A second phase of our experiment instructed crowd workers and students to create simulations on our Virtual Wind Tunnel website to solve a more complex task.With a sufficiently comprehensive tutorial and compensation similar to typical crowd-sourcing wages, we were able to enlist crowd workers to effectively complete longer, more complex tasks with competence comparable to that of graduate students with more comprehensive, expert-level knowledge. Furthermore, more complex tasks require increased communication with the workers. As tasks become more complex, the employment relationship begins to become more akin to outsourcing than crowdsourcing. Through this investigation, we were able to stretch and explore the limits of crowdsourcing as a tool for solving complex

  3. Nicotine improves antisaccade task performance without affecting prosaccades.

    Science.gov (United States)

    Larrison, Abigail L; Briand, Kevin A; Sereno, Anne B

    2004-08-01

    Although there is ample evidence for a cognitive-attentional benefit of the stimulant nicotine, the source of this benefit is not as well understood. One approach is to address what aspects of performance nicotine affects at a functional systems level. It is currently debated whether the benefits produced by nicotine are the effect of enhanced higher cognitive function or reflect an overall increase in general arousal. In order to address this question, the effects of nicotine on two simple eye movement tasks were studied: the saccade (S) and antisaccade (AS) tasks. Because the S and AS tasks utilize identical sensory stimuli (peripheral targets) and require identical motor responses (eye movements) but differ significantly in their cognitive demands, the use of these two tasks should enable a parsing of nicotine effects on cognitive versus sensory-motor processes. In this study, the S and AS tasks were performed by two experimental groups, task naïve subjects and highly practised subjects. For the first group, that of the task naïve subjects, nicotine gum administration resulted in a decrease in AS errors. For the second group, that of two experienced subjects tested repeatedly over a 3 week period, nicotine also produced a significant decrease in AS task errors, as well as resulting in a significant decrease in AS response times. Neither task naïve nor experienced subjects showed any effects of nicotine on the S task. Examining the effects of nicotine on highly controlled and constrained tasks such as the S and AS task may provide another level of insight into the mechanisms underlying the beneficial cognitive effects of nicotine. Copyright 2004 John Wiley & Sons, Ltd.

  4. Brain network adaptability across task states.

    Directory of Open Access Journals (Sweden)

    Elizabeth N Davison

    2015-01-01

    Full Text Available Activity in the human brain moves between diverse functional states to meet the demands of our dynamic environment, but fundamental principles guiding these transitions remain poorly understood. Here, we capitalize on recent advances in network science to analyze patterns of functional interactions between brain regions. We use dynamic network representations to probe the landscape of brain reconfigurations that accompany task performance both within and between four cognitive states: a task-free resting state, an attention-demanding state, and two memory-demanding states. Using the formalism of hypergraphs, we identify the presence of groups of functional interactions that fluctuate coherently in strength over time both within (task-specific and across (task-general brain states. In contrast to prior emphases on the complexity of many dyadic (region-to-region relationships, these results demonstrate that brain adaptability can be described by common processes that drive the dynamic integration of cognitive systems. Moreover, our results establish the hypergraph as an effective measure for understanding functional brain dynamics, which may also prove useful in examining cross-task, cross-age, and cross-cohort functional change.

  5. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician)…

  6. Pregnancy and medical radiation, ICRP Publication 84

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-01

    Thousands of pregnant patients and radiation workers are exposed to ionising radiation each year. Lack of knowledge is responsible for great anxiety and probably unnecessary termination of pregnancies. For many patients, the exposure is appropriate, while for others the exposure may be inappropriate, placing the unborn child at increased risk. Prenatal doses from most properly done diagnostic procedures present no measurably increased risk of prenatal death, malformation, or impairment of mental development over the background incidence of these entities. Higher doses, such as those involved in therapeutic procedures, can result in significant fetal harm. The pregnant patient or worker has a right to know the magnitude and type of potential radiation effects that might result from in utero exposure. Almost always, if a diagnostic radiology examination is medically indicated, the risk to the mother of not doing the procedure is greater than is the risk of potential harm to the fetus. Most nuclear medicine procedures do not cause large fetal doses. However, some radiopharmaceuticals that are used in nuclear medicine can pose significant fetal risks. It is important to ascertain whether a female patient is pregnant prior to radiotherapy. In pregnant patients, cancers that are remote from the pelvis usually can be heated with radiotherapy. This however requires careful planning. Cancers in the pelvis cannot be adequately treated during pregnancy without severe or lethal consequences for the fetus. The basis for the control of the occupational exposure of women who are not pregnant is the same as that for men. However, if a woman is, or may be, pregnant, additional controls have to be considered to protect the unborn child. In many countries, radiation exposure of pregnant females in biomedical research is not specifically prohibited. However, their involvement in such research is very rare and should be discouraged. Termination of pregnancy is an individual decision affected by many factors. Fetal doses below 100 mGy should not be considered a reason for terminating a pregnancy. At fetal doses above this level, informed decisions should be made based upon individual circumstances.

  7. Task conflicts and exclusive professionalism in nursing in South Korea.

    Science.gov (United States)

    Jung, Minsoo

    2014-01-01

    Task conflicts among medical professions are essential problems to be solved in health care organizations. This study examined job conflicts between practical nurses (PNs) and registered nurses (RNs) in their duties and tasks with representative panelists from South Korea. This qualitative study used the Dacum Task Analysis process. Subject-matter experts in practical nursing were recruited utilizing stratified sampling: Ten experts developed job descriptions of PNs, and 20 validated the descriptions. The on-site tasks and duties of the PNs were measured by means of Dacum, and the results were reviewed by RNs using 3 focus-group interviews. The job description of PNs consisted of 10 duties and 117 tasks, overlapping with some tasks of RNs. Core tasks performed by PNs, such as invasive activities, led to task conflicts between the 2 groups, as these activities were regarded as the inherent duty of nursing professions. Thus, the RNs did not concede the expanded job scope of the PNs in terms of exclusive professionalism. To reduce task conflict, there is a need for the balanced development of nursing professionalism.

  8. Predicting Satisfaction with Group Work Assignments

    Science.gov (United States)

    Burdett, Jane; Hastie, Brianne

    2009-01-01

    Universities are increasingly using group based assessment tasks; however, as with work-place teams, such tasks often elicit mixed feelings from participants. This study investigated factors that may predict student satisfaction with group work at university. Final-year business students completed a questionnaire addressing experiences of group…

  9. Expert group formation using facility location analysis

    NARCIS (Netherlands)

    Neshati, Mahmood; Beigy, Hamid; Hiemstra, Djoerd

    2014-01-01

    In this paper, we propose an optimization framework to retrieve an optimal group of experts to perform a multi-aspect task. While a diverse set of skills are needed to perform a multi-aspect task, the group of assigned experts should be able to collectively cover all these required skills. We consid

  10. Children's construction task performance and spatial ability: controlling task complexity and predicting mathematics performance.

    Science.gov (United States)

    Richardson, Miles; Hunt, Thomas E; Richardson, Cassandra

    2014-12-01

    This paper presents a methodology to control construction task complexity and examined the relationships between construction performance and spatial and mathematical abilities in children. The study included three groups of children (N = 96); ages 7-8, 10-11, and 13-14 years. Each group constructed seven pre-specified objects. The study replicated and extended previous findings that indicated that the extent of component symmetry and variety, and the number of components for each object and available for selection, significantly predicted construction task difficulty. Results showed that this methodology is a valid and reliable technique for assessing and predicting construction play task difficulty. Furthermore, construction play performance predicted mathematical attainment independently of spatial ability.

  11. Task Prioritization in Dual-Tasking: Instructions versus Preferences

    Science.gov (United States)

    Jansen, Reinier J.; van Egmond, René; de Ridder, Huib

    2016-01-01

    The role of task prioritization in performance tradeoffs during multi-tasking has received widespread attention. However, little is known on whether people have preferences regarding tasks, and if so, whether these preferences conflict with priority instructions. Three experiments were conducted with a high-speed driving game and an auditory memory task. In Experiment 1, participants did not receive priority instructions. Participants performed different sequences of single-task and dual-task conditions. Task performance was evaluated according to participants’ retrospective accounts on preferences. These preferences were reformulated as priority instructions in Experiments 2 and 3. The results showed that people differ in their preferences regarding task prioritization in an experimental setting, which can be overruled by priority instructions, but only after increased dual-task exposure. Additional measures of mental effort showed that performance tradeoffs had an impact on mental effort. The interpretation of these findings was used to explore an extension of Threaded Cognition Theory with Hockey’s Compensatory Control Model. PMID:27391779

  12. Challenges Facing Group Work Online

    Science.gov (United States)

    Chang, Bo; Kang, Haijun

    2016-01-01

    Online group work can be complicated because of its asynchronous characteristics and lack of physical presence, and its requirements for skills in handling technology, human relationships, and content-related tasks. This study focuses on the administrative, logistical and relationship-related challenges in online group work. Challenges in areas…

  13. Time constraints in the alcohol purchase task.

    Science.gov (United States)

    Kaplan, Brent A; Reed, Derek D; Murphy, James G; Henley, Amy J; Reed, Florence D DiGennaro; Roma, Peter G; Hursh, Steven R

    2017-06-01

    Hypothetical purchase tasks have advanced behavioral economic evaluations of demand by circumventing practical and ethical restrictions associated with delivering drug reinforcers to participants. Numerous studies examining the reliability and validity of purchase task methodology suggest that it is a valuable method for assessing demand that warrants continued use and evaluation. Within the literature examining purchase tasks, the alcohol purchase task (APT) has received the most investigation, and currently represents the most experimentally validated variant. However, inconsistencies in purchase task methodology between studies exist, even within APT studies, and, to date, none have assessed the influence of experimental economic constraints on responding. This study examined changes in Q0 (reported consumption when drinks are free), breakpoint (price that suppresses consumption), and α (rate of change in demand elasticity) in the presence of different hypothetical durations of access to alcohol in an APT. One hundred seventy-nine participants (94 males, 85 females) from Amazon Mechanical Turk completed 3 APTs that varied in the duration of time at a party (i.e., access to alcoholic beverages) as described in the APT instructions (i.e., vignette). The 3 durations included 5-hr (used by Murphy et al., 2013), 1-hr, and 9-hr time frames. We found that hypothetical duration of access was significantly related to Q0 and breakpoint at the individual level. Additionally, group-level mean α decreased significantly with increases in duration of access, thus indicating relatively higher demand for alcohol with longer durations of access. We discuss implications for conducting hypothetical purchase task research and alcohol misuse prevention efforts. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Large solar energy systems within IEA task 14

    NARCIS (Netherlands)

    Geus, A.C. de; Isakson, P.; Bokhoven, T.P.; Vanoli, K.; Tepe, R.

    1996-01-01

    Within IEA Task 14 (Advanced Solar Systems) a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design and construction of advanced large solar systems.

  15. Large solar energy systems within IEA task 14

    NARCIS (Netherlands)

    Geus, A.C. de; Isakson, P.; Bokhoven, T.P.; Vanoli, K.; Tepe, R.

    1996-01-01

    Within IEA Task 14 (Advanced Solar Systems) a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design and construction of advanced large solar systems.

  16. Task Analyses for Difficult-to-Assess Collective Tasks

    Science.gov (United States)

    2014-02-01

    Counterintelligence and Human Intelligence Analysis and Production (34-4-1305) • Conduct Counterintelligence and Human Intelligence Analysis (34-4...Research Product 2014-05 Task Analyses for Difficult-to-Assess Collective Tasks Jonathan J. Bryson Rachel D. Barney...Christina K. Curnow Trevor M. Conrad Arnold L. Leonard Heidi Keller-Glaze ICF International Jennifer S. Tucker Christopher L. Vowels

  17. New Developments in the Optimisation Principle Broadening the Process

    Energy Technology Data Exchange (ETDEWEB)

    Wolfgang Weiss; Mary Clark; Ted Lazo; Jean-Fran is Lecomte; Jacques Lochard; Xia Yihua [ICRP Secretariat, Stockholm (Sweden)

    2006-07-01

    On October 20, 2001 the Main Commission of the International Commission on Radiological Protection (ICRP) approved the formation of a new Task Group, reporting to Committee 4, to develop guidance on the principle and application of the optimization of radiological protection. As stated in the terms of reference, the objective of the Task Group was to review the principle of optimization and the requirements for its implementation in relation to the revised ICRP general recommendations. In this perspective, particular attention had to be given to the role of constraints, the distribution of individual exposures, stakeholder involvement and application in regulation and operation. (N.C.)

  18. Evaluation of individual neutron dosimetry by a working group in the French nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Rannou, A. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Clech, A. [Compagnie Generale des Matieres Nucleaires (COGEMA), 30 - Bagnols-sur-Ceze (France). Etablissement de Marcoule; Devita, A. [CEA Centre de Marcoule, 30 - Bagnols-sur-Ceze (France); Dollo, R. [Electricite de France (EDF), 75 - Paris (France). Comite de Radioprotection; Pescayre, G. [CEA Centre d`Etudes de Valduc, 21 - Is-sur-Tille (France)

    1997-09-01

    The difficulty of properly measuring neutron doses received by the workers in the nuclear industry is becoming more acute in the context of the revised recommendations of the ICRP Publication 60. A working group composed of representatives of the French nuclear industry was set up at the end of 1992 with the aim of assessing the extent of this problem and looking for appropriate solutions. The aims were (i) to define the needs as far as neutron dosimetry is concerned, (ii) to examine the different techniques used or currently available, and (iii) to draw up the specifications for the individual dosemeter which would ideally satisfy all the technical and practical requirements. This paper is intended as a first review of the analysis made. (author).

  19. A Study on Affective Decision -making of Children with Different Aggression/Victim Groups by Gambling Task,%运用赌博任务测查不同攻击/受欺类别儿童的情感决策过程

    Institute of Scientific and Technical Information of China (English)

    李亚真; 桑标

    2012-01-01

    攻击行为认知研究存在的一个重要问题是忽视情感对儿童认知加工的影响。考虑了情绪-认知整合过程的儿童行为决策更能全面而真实地反映社会信息加工情境下的攻击/受欺行为卷入过程。情感决策的赌博任务范式被认为能诱发类似于个人真实生活决策的表现,本研究运用计算机程序编制的标准赌博任务,以过程的视角考察了不同攻击/受欺儿童的情感决策特点。结果发现,不同类型儿童的有利-不利选择净分数、对有利-不利选择及奖惩频数的决策偏向存在显著差异。研究结果反映未卷入儿童在赌博任务上的整体表现优于其他类型儿童,攻击-受欺儿童仅次于未卷入儿童;直接攻击、攻击-受欺、未卷入儿童呈现惩罚定向的决策风格,但这三类儿童也表现出截然不同的趋势。%Aggressive behavior has been a hot topic in the field of developmental psychology. One of the important problems in the study of aggressive behavior is that researchers neglect the influence of emotion on children's cognitive procession. In addition, there were few studies that probed the characteristics of decision-making of the children involved in the aggression/victim situation. If researchers took the integrated process of emotion and cognition into consideration when exploring children's decision-making, the results would reflect more truly and comprehensively the involved process of aggression/victim in social information processing. The gambling task paradigm of affective decision-making is believed to induce performance similar to the individual decision-making behavior in real life. A self-designed computer program of standard gambling task, in which 80 test items were divided into four blocks, was used to compare the decision-making achievement of the children belonging to different aggression/victim groups in different periods from the process perspective to reveal the

  20. Efficacy of Mirror Therapy Containing Functional Tasks in Poststroke Patients

    OpenAIRE

    Lim, Kil-Byung; Lee, Hong-Jae; Yoo, JeeHyun; Yun, Hyun-Ju; Hwang, Hye-Jung

    2016-01-01

    Objective To investigate the effect of mirror therapy containing functional tasks on upper extremity function and activities of daily living in patients with subacute stroke. Methods The subjects were randomly divided into two groups: the mirror therapy group (30 patients) and the sham therapy group (30 patients). The mirror therapy group underwent a mirror therapy program together with conventional therapy for 20 minutes per day on 5 days per week for 4 weeks. The control group received a sh...

  1. Eliminating dual-task costs by minimizing crosstalk between tasks: The role of modality and feature pairings.

    Science.gov (United States)

    Göthe, Katrin; Oberauer, Klaus; Kliegl, Reinhold

    2016-05-01

    We tested the independent influences of two content-based factors on dual-task costs, and on the parallel processing ability: The pairing of S-R modalities and the pairing of relevant features between stimuli and responses of two tasks. The two pairing factors were realized across four dual-task groups. Within each group the two tasks comprised two different stimulus modalities (visual and auditory), two different relevant stimulus features (spatial and verbal) and two response modalities (manual and vocal). Pairings of S-R modalities (standard: visual-manual and auditory-vocal, non-standard: visual-vocal and auditory-manual) and feature pairings (standard: spatial-manual and verbal-vocal, non-standard: spatial-vocal and verbal-manual) varied across groups. All participants practiced their respective dual-task combination in a paradigm with simultaneous stimulus onset before being transferred to a psychological refractory period paradigm varying stimulus-onset asynchrony. A comparison at the end of practice revealed similar dual-task costs and similar pairing effects in both paradigms. Dual-task costs depended on modality and feature pairings. Groups training with non-standard feature pairings (i.e., verbal stimulus features mapped to spatially separated response keys, or spatial stimulus features mapped to verbal responses) and non-standard modality pairings (i.e., auditory stimulus mapped to manual response, or visual stimulus mapped to vocal responses) had higher dual-task costs than respective standard pairings. In contrast, irrespective of modality pairing dual-task costs virtually disappeared with standard feature pairings after practice in both paradigms. The results can be explained by crosstalk between feature-binding processes for the two tasks. Crosstalk was present for non-standard but absent for standard feature pairings. Therefore, standard feature pairings enabled parallel processing at the end of practice.

  2. Group X

    Energy Technology Data Exchange (ETDEWEB)

    Fields, Susannah

    2007-08-16

    This project is currently under contract for research through the Department of Homeland Security until 2011. The group I was responsible for studying has to remain confidential so as not to affect the current project. All dates, reference links and authors, and other distinguishing characteristics of the original group have been removed from this report. All references to the name of this group or the individual splinter groups has been changed to 'Group X'. I have been collecting texts from a variety of sources intended for the use of recruiting and radicalizing members for Group X splinter groups for the purpose of researching the motivation and intent of leaders of those groups and their influence over the likelihood of group radicalization. This work included visiting many Group X websites to find information on splinter group leaders and finding their statements to new and old members. This proved difficult because the splinter groups of Group X are united in beliefs, but differ in public opinion. They are eager to tear each other down, prove their superiority, and yet remain anonymous. After a few weeks of intense searching, a list of eight recruiting texts and eight radicalizing texts from a variety of Group X leaders were compiled.

  3. Caffeine improves anticipatory processes in task switching

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Wijnen, Jasper G.; Lorist, Monicque M.; Ridderinkhof, K. Richard

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials

  4. Caffeine improves anticipatory processes in task switching

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Wijnen, Jasper G.; Lorist, Monicque M.; Ridderinkhof, K. Richard

    2006-01-01

    We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e

  5. Cognitive impairments of aphasics in picture sorting and matching tasks.

    Science.gov (United States)

    Cohen, R; Glöckner-Rist, A; Lutz, M; Maier, T; Meier, E

    1982-01-01

    On the basis of earlier experiments showing a differential deficit of aphasics in picture sorting and matching tasks, two experiments were conducted to test the conjecture of a specific deficit of aphasics in the analytical appraisal of individual features. Broca's and Wernicke's aphasics--according to clinical diagnoses and the Aachener Aphasie Test--were compared with patients having right-hemisphere lesions or left-hemisphere lesions without aphasia. Both groups of aphasics differed from the control groups in the sorting task, irrespective of the sorting criterion, but the differences were small. The picture matching task did not discriminate between groups. Obviously, the basic assumption has to be modified with respect to specific conditions of task requirements. The experimental literature is reviewed.

  6. Modeling of Task Planning for Multirobot System Using Reputation Mechanism

    Directory of Open Access Journals (Sweden)

    Zhiguo Shi

    2014-01-01

    Full Text Available Modeling of task planning for multirobot system is developed from two parts: task decomposition and task allocation. In the part of task decomposition, the conditions and processes of decomposition are elaborated. In the part of task allocation, the collaboration strategy, the framework of reputation mechanism, and three types of reputations are defined in detail, which include robot individual reputation, robot group reputation, and robot direct reputation. A time calibration function and a group calibration function are designed to improve the effectiveness of the proposed method and proved that they have the characteristics of time attenuation, historical experience related, and newly joined robot reward. Tasks attempt to be assigned to the robot with higher overall reputation, which can help to increase the success rate of the mandate implementation, thereby reducing the time of task recovery and redistribution. Player/Stage is used as the simulation platform, and three biped-robots are established as the experimental apparatus. The experimental results of task planning are compared with the other allocation methods. Simulation and experiment results illustrate the effectiveness of the proposed method for multi-robot collaboration system.

  7. Decision paths in complex tasks

    Science.gov (United States)

    Galanter, Eugene

    1991-01-01

    Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

  8. Putting Mathematical Tasks into Context

    Science.gov (United States)

    Nagle, Courtney R.; Styers, Jodie L.

    2015-01-01

    Although many factors affect students' mathematical activity during a lesson, the teacher's selection and implementation of tasks is arguably the most influential in determining the level of student engagement. Mathematical tasks are intended to focus students' attention on a particular mathematical concept and it is the careful developing and…

  9. Human-System task integration

    NARCIS (Netherlands)

    Schraagen, J.M.C.

    2005-01-01

    The Dutch Ministry of Defence research programme Human-System Task Integration aims at acquiring knowledge for the optimal cooperation between human and computer, under the following constraints: freedom of choice in decisions to automate and multiple, dynamic task distributions. This paper describe

  10. Designing for dynamic task allocation

    NARCIS (Netherlands)

    Dongen, C.J.G. van; Maanen, P.P. van

    2005-01-01

    Future platforms are envisioned in which human-machine teams are able to share and trade tasks as demands in situations change. It seems that human-machine coordination has not received the attention it deserves by past and present approaches to task allocation. In this paper a simple way to make co

  11. Creativity, Overinclusion, and Everyday Tasks

    Science.gov (United States)

    Ottemiller, Dylan D.; Elliott, Colette Seter; Giovannetti, Tania

    2014-01-01

    This study examined relations between creative thinking and performance on routine, everyday tasks. Results were considered in light of past research on the putative relation between creativity and schizophrenia/psychotic thinking. Thirty healthy undergraduates completed the Alternative Uses Task, a measure of divergent thinking, and the 2 × 3…

  12. Task modeling for collaborative authoring

    NARCIS (Netherlands)

    Veer, van der Gerrit; Kulyk, Olga; Vyas, Dhaval; Kubbe, Onno; Ebert, Achim; Dittmar, A.; Forbrig, P.

    2011-01-01

    Motivation –Task analysis for designing modern collaborative work needs a more fine grained approach. Especially in a complex task domain, like collaborative scientific authoring, when there is a single overall goal that can only be accomplished only by collaboration between multiple roles, each req

  13. EFFORTS Sub-task report on task 4.1: Experimental Techniques

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Bay, Niels

    1998-01-01

    Task 4.1 is a sub-task of task 4: Physical modelling validation. In sub-task 4.1 the existing experimental techniques has been conditioned to the tasks ahead in physical modelling.......Task 4.1 is a sub-task of task 4: Physical modelling validation. In sub-task 4.1 the existing experimental techniques has been conditioned to the tasks ahead in physical modelling....

  14. Ergonomic factors on task performance in laparoscopic surgery training.

    Science.gov (United States)

    Xiao, D J; Jakimowicz, Jack J; Albayrak, A; Goossens, R H M

    2012-05-01

    This paper evaluates the effect of ergonomic factors on task performance and trainee posture during laparoscopic surgery training. Twenty subjects without laparoscopic experience were allotted into 2 groups. Group 1 was trained under the optimal ergonomic simulation setting according to current ergonomic guidelines (Condition A). Group 2 was trained under non-optimal ergonomic simulation setting that can often be observed during training in a skills lab (Condition B). Posture analysis showed that the subjects held a much more neutral posture under Condition A than under Condition B (poptimal ergonomic simulation setting leads to better task performance. In addition, no significant differences of task performance, for Groups 1 and 2 using the same test setting were found. However, better performance was observed for Group 1. It can be concluded that the optimal and non-optimal training setting have different learning effects on trainees' skill learning.

  15. Group morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2000-01-01

    In its original form, mathematical morphology is a theory of binary image transformations which are invariant under the group of Euclidean translations. This paper surveys and extends constructions of morphological operators which are invariant under a more general group TT, such as the motion group

  16. Evolution of Self-Organized Task Specialization in Robot Swarms.

    Directory of Open Access Journals (Sweden)

    Eliseo Ferrante

    2015-08-01

    Full Text Available Division of labor is ubiquitous in biological systems, as evidenced by various forms of complex task specialization observed in both animal societies and multicellular organisms. Although clearly adaptive, the way in which division of labor first evolved remains enigmatic, as it requires the simultaneous co-occurrence of several complex traits to achieve the required degree of coordination. Recently, evolutionary swarm robotics has emerged as an excellent test bed to study the evolution of coordinated group-level behavior. Here we use this framework for the first time to study the evolutionary origin of behavioral task specialization among groups of identical robots. The scenario we study involves an advanced form of division of labor, common in insect societies and known as "task partitioning", whereby two sets of tasks have to be carried out in sequence by different individuals. Our results show that task partitioning is favored whenever the environment has features that, when exploited, reduce switching costs and increase the net efficiency of the group, and that an optimal mix of task specialists is achieved most readily when the behavioral repertoires aimed at carrying out the different subtasks are available as pre-adapted building blocks. Nevertheless, we also show for the first time that self-organized task specialization could be evolved entirely from scratch, starting only from basic, low-level behavioral primitives, using a nature-inspired evolutionary method known as Grammatical Evolution. Remarkably, division of labor was achieved merely by selecting on overall group performance, and without providing any prior information on how the global object retrieval task was best divided into smaller subtasks. We discuss the potential of our method for engineering adaptively behaving robot swarms and interpret our results in relation to the likely path that nature took to evolve complex sociality and task specialization.

  17. Divergent Perceptions of Telecollaborative Language Learning Tasks: Task-as-Workplan vs. Task-as-Process

    National Research Council Canada - National Science Library

    Dooly, Melinda

    2011-01-01

    ... place. The task design and its implementation are key elements for efficient language learning to develop--a carefully designed task or activity that requires off- and online co-construction of knowledge not only provides opportunities for target language practice, it also helps integrate language use as the means for shared knowledge-build...

  18. University Students' Emotion During Online Search Task: A Multiple Achievement Goal Perspective.

    Science.gov (United States)

    Zhou, Mingming

    2016-07-03

    Endorsing a multiple goal perspective, students' academic emotions were examined with different goal profiles while solving learning tasks online. One hundred and seven Chinese undergraduates were classified based on the 2 × 2 achievement goal framework into three groups: Mastery-approach-focused, Approach-oriented, and Avoidance-oriented group. Participants' emotional states were assessed immediately prior to the task and following the task. Prior to the task, the Avoidance-oriented group reported significantly higher levels of deactivated negative emotion (i.e., bored and confused) than the Approach-oriented group. The Mastery-approach-focused group reported significantly higher levels of activated positive emotions (i.e., excited and eager) than the Avoidance-oriented group after the task. Within each group, all three groups followed a similar emotion change pattern prior versus after the search task in deactivated positive emotion, with a significant increase. In addition, the Mastery-approach-focused group also reported a significantly higher level of happiness after completing the task, whereas the other two groups did not report much change. The Avoidance-oriented group also reported a significant drop in the feeling of excitement, eagerness, anxiety, and nervousness; whereas, the Approach-oriented group reported a significantly higher level of confusion after the task was finished. Implications of the findings are further discussed.

  19. 75 FR 16902 - Aviation Rulemaking Advisory Committee; Transport Airplane and Engine Issue Area-New Task

    Science.gov (United States)

    2010-04-02

    ... working group will be expected to provide a report that addresses the following low speed alerting... working group will be also be expected to provide a report that addresses the following low speed alerting... the existing Avionics Systems Harmonization Working Group. The Task ARAC is initially tasked...

  20. Postural Adaptations to a Suprapostural Memory Task among Children with and without Developmental Coordination Disorder

    Science.gov (United States)

    Chen, Fu-Chen; Tsai, Chia-Liang; Stoffregen, Thomas A.; Chang, Chihu-Hui; Wade, Michael G.

    2012-01-01

    Aim: The present study investigated the effects of varying the cognitive demands of a memory task (a suprapostural task) while recording postural motion on two groups of children, one diagnosed with developmental coordination disorder (DCD) and an age-matched group of typically developing children. Method: Two groups, each comprising 38 child…

  1. Task Management in the New ATLAS Production System

    CERN Document Server

    De, K; The ATLAS collaboration; Klimentov, A; Potekhin, M; Vaniachine, A

    2014-01-01

    The ATLAS Production System is the top level workflow manager which translates physicists' needs for production level processing into actual workflows executed across about a hundred processing sites used globally by ATLAS. As the production workload increased in volume and complexity in recent years (the ATLAS production tasks count is above one million, with each task containing hundreds or thousands of jobs) there is a need to upgrade the Production System to meet the challenging requirements of the next LHC run while minimizing the operating costs. Providing a front-end and a management layer for petascale data processing and analysis, the new Production System contains generic subsystems that can be used in a wider range of applications. The main subsystems are the Database Engine for Tasks (DEFT) and the Job Execution and Definition Interface (JEDI). Based on users' requests, the DEFT subsystem manages inter-dependent groups of tasks (Meta-Tasks) and generates corresponding data processing workflows. Th...

  2. Task Management in the New ATLAS Production System

    CERN Document Server

    De, K; The ATLAS collaboration; Klimentov, A; Potekhin, M; Vaniachine, A

    2013-01-01

    The ATLAS Production System is the top level workflow manager which translates physicists' needs for production level processing into actual workflows executed across about a hundred processing sites used globally by ATLAS. As the production workload increased in volume and complexity in recent years (the ATLAS production tasks count is above one million, with each task containing hundreds or thousands of jobs) there is a need to upgrade the Production System to meet the challenging requirements of the next LHC run while minimizing the operating costs. Providing a front-end and a management layer for petascale data processing and analysis, the new Production System contains generic subsystems that can be used in a wider range of applications. The main subsystems are the Database Engine for Tasks (DEFT) and the Job Execution and Definition Interface (JEDI). Based on users' requests, the DEFT subsystem manages inter-dependent groups of tasks (Meta-Tasks) and generates corresponding data processing workflows. Th...

  3. Age-related differences in multiple task monitoring.

    Directory of Open Access Journals (Sweden)

    Ivo Todorov

    Full Text Available Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men exceeded women in multitasking, measured as monitoring accuracy. Individual differences in executive functioning and spatial ability were independent predictors of young adults' monitoring accuracy, but only spatial ability was related to sex differences. For older adults, age and executive functioning, but not spatial ability, predicted multitasking performance. These results suggest that executive functions contribute to multiple task performance across the adult life span and that reliance on spatial skills for coordinating deadlines is modulated by age.

  4. Age-related differences in multiple task monitoring.

    Science.gov (United States)

    Todorov, Ivo; Del Missier, Fabio; Mäntylä, Timo

    2014-01-01

    Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men exceeded women in multitasking, measured as monitoring accuracy. Individual differences in executive functioning and spatial ability were independent predictors of young adults' monitoring accuracy, but only spatial ability was related to sex differences. For older adults, age and executive functioning, but not spatial ability, predicted multitasking performance. These results suggest that executive functions contribute to multiple task performance across the adult life span and that reliance on spatial skills for coordinating deadlines is modulated by age.

  5. The classical task

    DEFF Research Database (Denmark)

    Gillis, Steven; Souman, Agnita; Dhollander, Sim

    of the experiment will give a picture of how children's knowledge develops over time and how well the dimensions ‘suffix predictability' and ‘stem transparency' are able to account for children's behavior.   Method Subjects: For each of the four languages, 20 subjects were tested in 7 age groups, ranging from 3...... the test words were found in child addressed speech, see the longitudinal data.   Predictions: Given that the model underlying the design of the experiment was identical for each language, we predicted that the outcome would be identical for each language. More specifically, the following predictions were...... picture shows two (or more) instances of X and the test leader says: "Here are two/a lot of ...." and the child is expected to provide the plural form of X. Stimuli: The target words used in the experiment were easily picturable and judged to be known even by the youngest participants. Moreover, all...

  6. The classical task

    DEFF Research Database (Denmark)

    Gillis, Steven; Souman, Agnita; Dhollander, Sim

    the test words were found in child addressed speech, see the longitudinal data.   Predictions: Given that the model underlying the design of the experiment was identical for each language, we predicted that the outcome would be identical for each language. More specifically, the following predictions were...... articulated: Prediction 1: a global analysis of the plural forms provided by the subjects is expected to show an increase of the correct responses as children grow older. Prediction 2: As to suffix selection, we expect that the plural of nouns selecting a fully predictable suffix will be more readily mastered......, be ‘easier' (more correct scores) and will be earlier acquired. Stimuli in the right cell at the bottom will be the hardest in each age group, and will be acquired later than the stimuli in any other cell.   Results: On the whole the results are in agreement with the predictions, in that for each language...

  7. Simulations for EBS Task Force BMT 1

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. [Marintel Ky, Turku (Finland)

    2006-12-15

    The Aespoe HRL International Joint Committee has set up a Task Force on Engineered Barrier Systems (EBS). Its long time objective is to develop effective tools for analysis of THM(C) behaviour of buffer and backfill. The idea of the Task Force is to offer a forum to develop the tools of the work groups. This BMT has two parts: BMT 1.1 and BMT 1.2 based on the performance of THM mock-up experiments on MX-80 bentonite by CEA and FEBEX bentonite by CIEMAT, respectively. Simulation results are presented here. These simulations are performed with Freefem++ software, which is a high-level programming language for solving partiel differential equations with finite element method. The mathematical model used is based on continuum thermodynamics. The simulations repeat the evolution of relevant THM variables of the experiments fairly well, but some modificatios of parameters is needed, especially in hydraulic behaviour. (orig.)

  8. The modality effect of ego depletion: Auditory task modality reduces ego depletion.

    Science.gov (United States)

    Li, Qiong; Wang, Zhenhong

    2016-08-01

    An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion.

  9. Group devaluation and group identification

    NARCIS (Netherlands)

    Leach, C.W.; Rodriguez Mosquera, P.M.; Vliek, M.L.W.; Hirt, E.

    2010-01-01

    In three studies, we showed that increased in-group identification after (perceived or actual) group devaluation is an assertion of a (preexisting) positive social identity that counters the negative social identity implied in societal devaluation. Two studies with real-world groups used order manip

  10. Theory of Mind in Williams Syndrome Assessed Using a Nonverbal Task

    Science.gov (United States)

    Porter, Melanie A.; Coltheart, Max; Langdon, Robyn

    2008-01-01

    This study examined Theory of Mind in Williams syndrome (WS) and in normal chronological age-matched and mental age-matched control groups, using a picture sequencing task. This task assesses understanding of pretence, intention and false belief, while controlling for social-script knowledge and physical cause-and-effect reasoning. The task was…

  11. A task dependent change in the medium latency component of the soleus stretch reflex

    DEFF Research Database (Denmark)

    Grey, Michael James; Larsen, Birgit; Sinkjær, Thomas

    2002-01-01

    In comparison to the H-reflex, the task dependency of the human stretch reflex during locomotive and postural tasks has not received a great deal of attention in the literature. The few studies on reflex task dependency that have been performed to date have concentrated on either the group Ia...

  12. DECOVALEX ll PROJECT. Technical Report Task 1C

    Energy Technology Data Exchange (ETDEWEB)

    Jing, L.; Stephansson, O. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Civil and Environmental Engineering; Knight, L.J. [United Kingdom Nirex Ltd., Harwell (United Kingdom); Kautsky, F. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Tsang, C-F. [Lawrence Berkeley National Lab., Berkeley, CA (United States). Earth Science Division

    1999-05-01

    The DECOVALEX II project is an international co-operative research project supported by eleven funding organizations from seven countries. The project studied four tasks: Task 1: numerical simulation of the RCF3 pump test at Sellafield, UK; Task 2: numerical simulation if the in situ T-H-M experiment at Kamaishi Mine, Japan; Task 3: monitoring of current development in rock fracture research; and Task 4: report on treatment of T-H-M processes in Performance Assessment works for nuclear waste repositories. The project started in 1995 and is scheduled to be finalised in June 1999. This report concerns the Task 1 of the DECOVALEX 11 project. Task 1 consists of three subtasks: i) Task 1 A - the blind numerical prediction to the hydraulic response of the rock mass of the in-situ RCF3 pump test in the Borrowdale Volcanic Group (BVG) at Sellafield, UK; ii) Task 1B -calibration of the numerical models of Task 1A against measured results of the RCF3 pump test; iii) Task 1C - the numerical predictions of the hydro-mechanical effects of the BVG rock mass to the excavation of a shaft along the axis of the RCF3 borehole, without actual excavation of the shaft and associated experiments and measurements. The aim of the subtasks 1 (A+B) was to characterise the hydro-mechanical property field of the fractured rock mass at the RCF3 test site, which could then be used to predict the hydro-mechanical responses of the rock mass to the excavation of a shaft centred on the RCF3 borehole. Task 1C involves a numerical simulation of an assumed excavation of a single shaft on the line of the RCF3 borehole used for Task 1 (A+B). The subtask is basically a generic prediction, with realistic site geology and hydrogeology data but without feedback from an actual excavation of the shaft and associated measurements. A model calibration is not possible due to lack of measured results. On the other hand, some additional components were introduced into the subtask, such as studies of EDZ formation

  13. Differences in dual-task performance and prefrontal cortex activation between younger and older adults

    Directory of Open Access Journals (Sweden)

    Ohsugi Hironori

    2013-01-01

    Full Text Available Abstract Background The purpose of this study was to examine task-related changes in prefrontal cortex (PFC activity during a dual-task in both healthy young and older adults and compare patterns of activation between the age groups. We also sought to determine whether brain activation during a dual-task relates to executive/attentional function and how measured factors associated with both of these functions vary between older and younger adults. Results Thirty-five healthy volunteers (20 young and 15 elderly participated in this study. Near-infrared spectroscopy (NIRS was employed to measure PFC activation during a single-task (performing calculations or stepping and dual-task (performing both single-tasks at once. Cognitive function was assessed in the older patients with the Trail-making test part B (TMT-B. Major outcomes were task performance, brain activation during task (oxygenated haemoglobin: Oxy-Hb measured by NIRS, and TMT-B score. Mixed ANOVAs were used to compare task factors and age groups in task performance. Mixed ANOVAs also compared task factors, age group and time factors in task-induced changes in measured Oxy-Hb. Among the older participants, correlations between the TMT-B score and Oxy-Hb values measured in each single-task and in the dual-task were examined using a Pearson correlation coefficient. Oxy-Hb values were significantly increased in both the calculation task and the dual-task within patients in both age groups. However, the Oxy-Hb values associated with there were higher in the older group during the post-task period for the dual-task. Also, there were significant negative correlations between both task-performance accuracy and Oxy-Hb values during the dual-task and participant TMT-B scores. Conclusions Older adults demonstrated age-specific PFC activation in response to dual-task challenge. There was also a significant negative correlation between PFC activation during dual-task and executive

  14. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam;

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged...... in large-N studies is therefore to define the concept of an interest group and to determine which classification scheme to use for different group types. After reviewing the existing literature, this article sets out to compare different approaches to defining and classifying interest groups with a sample...

  15. Drug and alcohol task force

    Energy Technology Data Exchange (ETDEWEB)

    Gordey, T. [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Sunstrum, M. [Enform, Calgary, AB (Canada)

    2006-07-01

    Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs.

  16. Task Space Tracking for Manipulators

    Directory of Open Access Journals (Sweden)

    Olav Egeland

    1985-04-01

    Full Text Available For the purpose of controlling a manipulator in the task space, a linear model with task space position and velocity as state variables can be developed. This is done by means of exact compensation of the state-space model non-linearities using non-linear feedback. In this paper, feedback control for this linear state space model is developed using optimal control theory. Integral action is included to compensate for unmodeled forces and torques. In the resulting control system, the problem of transforming the task space trajectory to the joint space is avoided, and the controller parameters can be chosen to satisfy requirements specified in the task space. Simulation experiments show promising results.

  17. Tasking and sharing sensing assets using controlled natural language

    Science.gov (United States)

    Preece, Alun; Pizzocaro, Diego; Braines, David; Mott, David

    2012-06-01

    We introduce an approach to representing intelligence, surveillance, and reconnaissance (ISR) tasks at a relatively high level in controlled natural language. We demonstrate that this facilitates both human interpretation and machine processing of tasks. More specically, it allows the automatic assignment of sensing assets to tasks, and the informed sharing of tasks between collaborating users in a coalition environment. To enable automatic matching of sensor types to tasks, we created a machine-processable knowledge representation based on the Military Missions and Means Framework (MMF), and implemented a semantic reasoner to match task types to sensor types. We combined this mechanism with a sensor-task assignment procedure based on a well-known distributed protocol for resource allocation. In this paper, we re-formulate the MMF ontology in Controlled English (CE), a type of controlled natural language designed to be readable by a native English speaker whilst representing information in a structured, unambiguous form to facilitate machine processing. We show how CE can be used to describe both ISR tasks (for example, detection, localization, or identication of particular kinds of object) and sensing assets (for example, acoustic, visual, or seismic sensors, mounted on motes or unmanned vehicles). We show how these representations enable an automatic sensor-task assignment process. Where a group of users are cooperating in a coalition, we show how CE task summaries give users in the eld a high-level picture of ISR coverage of an area of interest. This allows them to make ecient use of sensing resources by sharing tasks.

  18. Annual Progress report - General Task

    Energy Technology Data Exchange (ETDEWEB)

    Wesnousky, S.G.

    1993-09-30

    This report provides a summary of progress for the project {open_quotes}Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI).{close_quotes} A similar report was previously provided for the period of 1 October 1991 to 30 September 1992. The report initially covers the activities of the General Task and is followed by sections that describe the progress of the other ongoing tasks.

  19. Emotional reactivity and awareness of task performance in Alzheimer's disease.

    Science.gov (United States)

    Mograbi, Daniel C; Brown, Richard G; Salas, Christian; Morris, Robin G

    2012-07-01

    Lack of awareness about performance in tasks is a common feature of Alzheimer's disease. Nevertheless, clinical anecdotes have suggested that patients may show emotional or behavioural responses to the experience of failure despite reporting limited awareness, an aspect which has been little explored experimentally. The current study investigated emotional reactions to success or failure in tasks despite unawareness of performance in Alzheimer's disease. For this purpose, novel computerised tasks which expose participants to systematic success or failure were used in a group of Alzheimer's disease patients (n=23) and age-matched controls (n=21). Two experiments, the first with reaction time tasks and the second with memory tasks, were carried out, and in each experiment two parallel tasks were used, one in a success condition and one in a failure condition. Awareness of performance was measured comparing participant estimations of performance with actual performance. Emotional reactivity was assessed with a self-report questionnaire and rating of filmed facial expressions. In both experiments the results indicated that, relative to controls, Alzheimer's disease patients exhibited impaired awareness of performance, but comparable differential reactivity to failure relative to success tasks, both in terms of self-report and facial expressions. This suggests that affective valence of failure experience is processed despite unawareness of task performance, which might indicate implicit processing of information in neural pathways bypassing awareness. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Normative Feedback Effects on Learning a Timing Task

    Science.gov (United States)

    Wulf, Gabriele; Chiviacowsky, Suzete; Lewthwaite, Rebecca

    2010-01-01

    This study investigated the influence of normative feedback on learning a sequential timing task. In addition to feedback about their performance per trial, two groups of participants received bogus normative feedback about a peer group's average block-to-block improvement after each block of 10 trials. Scores indicated either greater (better…

  1. Task-Oriented Gaming for Transfer to Prosthesis Use

    NARCIS (Netherlands)

    van Dijk, Ludger; Sluis, van der Corry K.; van Dijk, Hylke W.; Bongers, Raoul M.

    2016-01-01

    The aim of this study is to establish the effect of task-oriented video gaming on using a myoelectric prosthesis in a basic activity of daily life (ADL). Forty-one able-bodied right-handed participants were randomly assigned to one of four groups. In three of these groups the participants trained to

  2. Groups and symmetry

    CERN Document Server

    Farmer, David W

    1995-01-01

    In most mathematics textbooks, the most exciting part of mathematics-the process of invention and discovery-is completely hidden from the reader. The aim of Groups and Symmetry is to change all that. By means of a series of carefully selected tasks, this book leads readers to discover some real mathematics. There are no formulas to memorize; no procedures to follow. The book is a guide: Its job is to start you in the right direction and to bring you back if you stray too far. Discovery is left to you. Suitable for a one-semester course at the beginning undergraduate level, there are no prerequ

  3. Examining the Effect of Task Complexity and Sequence on Speaking Ability of Iranian EFL Learners

    Directory of Open Access Journals (Sweden)

    Masoumeh Alipour Madarsara

    2015-01-01

    Full Text Available The impetus of the present study was to examine the effect of task complexity and sequence on speaking according to performance data collected from 60 intermediate Iranian EFL learners on two tasks (a map task and a car task. In order to examine the effects of task sequence and complexity in enhancing EFL learners’ speaking ability in three different areas including accuracy, fluency and complexity, descriptive statistics as well as independent samples T-tests were run to the results of each sections of the speaking test for both control and experimental groups in posttest. It was found that task sequence and complexity had significant effects on Iranian intermediate EFL learners’ speaking ability. The findings of the study also revealed that the participants in the experimental group, who practiced task sequence and complexity, far outweighed the control group in complexity and fluency than the other area of the speaking test.

  4. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

    Science.gov (United States)

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10) and in patients suffering from chronic stroke (−0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (−0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive–motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings. PMID:28356727

  5. Task-based incidental vocabulary learning in L2 Arabic: The role of proficiency and task performance

    Directory of Open Access Journals (Sweden)

    Ayman A. Mohamed

    2016-03-01

    Full Text Available This study tests the claim that word learning in a second language are contingent upon a task’s involvement load (i.e. the amount of need, search, and evaluation it imposes, as proposed by Laufer and Hulstijn (2001. Fifty-three English-speaking learners of Arabic were assigned to one of three vocabulary learning tasks that varied in the degree of involvement: reading comprehension with glosses (low, fill-in-the-gap task (medium, and sentence writing (high. Ten words, selected based on a pretest, were targeted in the tasks. Results showed a main effect of task, with the sentence writing task yielding the highest rates of vocabulary learning, followed by the gap-fill task, and finally the reading comprehension task. A significant correlation was found between accuracy of performance across participants and their subsequent vocabulary acquisition in the immediate posttest. Within groups, only the performance of the writing group correlated significantly with their posttest scores. Results of the present study validate the hypothesis and point to multiple factors at play in incidental vocabulary acquisition. The study provides further arguments to refine the hypothesis and implement pedagogical practices that accommodate incidental learning in foreign language settings.

  6. Characterizing "fibrofog": Subjective appraisal, objective performance, and task-related brain activity during a working memory task.

    Science.gov (United States)

    Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L; Rayhan, Rakib; VanMeter, John W; Gracely, Richard H

    2016-01-01

    The subjective experience of cognitive dysfunction ("fibrofog") is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, "fibrofog" appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks.

  7. Form-based Approaches vs. Task-Based Approaches

    Directory of Open Access Journals (Sweden)

    Zahra Talebi

    2015-07-01

    Full Text Available This study aimed at investigating whether task-based approaches bear any superiority to that of more traditional ones evident in presentation-practice- and production phase .to fulfill the purpose of the study, the participants within the age range of 11-19, took part in the study. Following a pretest, treatment, and a posttest, the obtained data was analyzed using analysis of covariance (ANCOVA to examine the effects of the variables. The results of the analysis showed that participants in the PPP group did significantly better in the grammar recognition of the posttest than that of the task group. However, their counterparts in the task group gained better scores in the writing section of the test .this research study provided evidence in support of task proponents' claim in the merit of task-based activity in raising learners' implicit knowledge claiming to play the primary role in spontaneous speech.Keywords: Task-based language teaching, PPP model, focus on form, focus on meaning

  8. Effects of a no-go Task 2 on Task 1 performance in dual - tasking: From benefits to costs.

    Science.gov (United States)

    Janczyk, Markus; Huestegge, Lynn

    2017-04-01

    When two tasks are combined in a dual-task experiment, characteristics of Task 2 can influence Task 1 performance, a phenomenon termed the backward crosstalk effect (BCE). Besides instances depending on the (spatial) compatibility of both responses, a particularly interesting example was introduced by Miller (2006): If Task 2 was a no-go task (i.e., one not requiring any action at all), responses were slowed in Task 1. Subsequent work, however, also reported the opposite result-that is, faster Task 1 responses in cases of no-go Task 2 trials. We report three experiments aiming to more precisely identify the conditions under which a no-go Task 2 facilitates or impedes Task 1 performance. The results suggest that an adverse no-go BCE is only observed when the Task 2 response(s) are sufficiently prepared in advance, yielding strong inhibitory control demands for Task 2 that eventually hamper Task 1 processing as well (i.e., inhibitory costs). If this is not the case, encountering a no-go Task 2 trial facilitates Task 1 performance, suggesting that the underlying task representation is reduced to a single - task. These results are discussed in the context of other recent work on BCEs and of recently suggested accounts of the no-go BCE.

  9. Physical Demands Study - Focus Groups

    Science.gov (United States)

    2015-10-26

    and the rounds in the boxes weigh 35 lb, which is lighter than equipment handled in the other physically demanding job tasks already identified...and standards. Ergonomics . 53: 858-871. 40 Appendix A: Questionnaires Completed by Volunteers prior to each Focus Group Interview 1 2 3 4a 4b 5

  10. Algebraic Groups

    DEFF Research Database (Denmark)

    2007-01-01

    The workshop continued a series of Oberwolfach meetings on algebraic groups, started in 1971 by Tonny Springer and Jacques Tits who both attended the present conference. This time, the organizers were Michel Brion, Jens Carsten Jantzen, and Raphaël Rouquier. During the last years, the subject...... of algebraic groups (in a broad sense) has seen important developments in several directions, also related to representation theory and algebraic geometry. The workshop aimed at presenting some of these developments in order to make them accessible to a "general audience" of algebraic group......-theorists, and to stimulate contacts between participants. Each of the first four days was dedicated to one area of research that has recently seen decisive progress: \\begin{itemize} \\item structure and classification of wonderful varieties, \\item finite reductive groups and character sheaves, \\item quantum cohomology...

  11. Group Grammar

    Science.gov (United States)

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  12. MUYANG GROUP

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research&development.project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.

  13. Relato histórico y categorías de inscripción pública del compromiso: aproximaciones al quehacer militante de los líderes de un grupo Historical narrative and categories of public‐registration: approximations of militancy tasks and know how's from leaders of a group

    Directory of Open Access Journals (Sweden)

    Melina Vázquez

    2012-12-01

    active occupation, how they develop their activist careers and how activist socialization takes place regarding leadership positions. In connection with this general purpose, the article analyzes one of the main tasks performed by the leaders; their role as spokespersons of the group. To do this, the investigation approaches a set of primary sources, especially, a political calendar elaborated in occasion of the seventh anniversary of an Unoccupied Workers Movement located in the south area of the Great Buenos Aires. The investigation seeks to show how the objectification of the group is performed through the development a historical narrative about the genesis of the group and categories of public-registration, such as "unemployed worker" and "autonomy".

  14. Polishing a Data Task: Seeking Better Assessment.

    Science.gov (United States)

    Zawojewski, Judith S.

    1996-01-01

    Shares a teacher's stages of selecting and revising a performance-assessment task focusing on data handling. Discusses selection and revision criteria, examining student work, reflecting on the task, and revising the final task. (MKR)

  15. Abelian groups

    CERN Document Server

    Fuchs, László

    2015-01-01

    Written by one of the subject’s foremost experts, this book focuses on the central developments and modern methods of the advanced theory of abelian groups, while remaining accessible, as an introduction and reference, to the non-specialist. It provides a coherent source for results scattered throughout the research literature with lots of new proofs. The presentation highlights major trends that have radically changed the modern character of the subject, in particular, the use of homological methods in the structure theory of various classes of abelian groups, and the use of advanced set-theoretical methods in the study of undecidability problems. The treatment of the latter trend includes Shelah’s seminal work on the undecidability in ZFC of Whitehead’s Problem; while the treatment of the former trend includes an extensive (but non-exhaustive) study of p-groups, torsion-free groups, mixed groups, and important classes of groups arising from ring theory. To prepare the reader to tackle these topics, th...

  16. Task-irrelevant perceptual expertise.

    Science.gov (United States)

    Wong, Yetta K; Folstein, Jonathan R; Gauthier, Isabel

    2011-12-05

    Perceptual learning (PL) and perceptual expertise (PE) are two fields of visual training studies that investigate how practice improves visual performance. However, previous research suggests that PL can be acquired in a task-irrelevant manner while PE cannot and that PL is highly specific to the training objects and conditions while PE generalizes. These differences are difficult to interpret since PL and PE studies tend to differ on multiple dimensions. We designed a training study with novel objects to compare PL and PE while varying only the training task, such that the training objects, visual field, training duration, and type of learning assessment were kept constant. Manipulations of the training task sufficed to produce the standard effects obtained in PE and PL. In contrast to prior studies, we demonstrated that some degree of PE can be acquired in a task-irrelevant manner, similar to PL. Task-irrelevant PE resulted in similar shape matching ability compared to the directly trained PE. In addition, learning in both PE and PL generalizes to different untrained conditions, which does not support the idea that PE generalizes while PL is specific. Degrees of generalization can be explained by considering the psychological space of the stimuli used for training and the test of transfer.

  17. Task-shifting: experiences and opinions of health workers in Mozambique and Zambia

    OpenAIRE

    Ferrinho Paulo; Sidat Mohsin; Goma Fastone; Dussault Gilles

    2012-01-01

    Abstract Background This paper describes the task-shifting taking place in health centres and district hospitals in Mozambique and Zambia. The objectives of this study were to identify the perceived causes and factors facilitating or impeding task-shifting, and to determine both the positive and negative consequences of task-shifting for the service users, for the services and for health workers. Methods Data collection involved individual and group interviews and focus group discussions with...

  18. Incidental Vocabulary Learning Through Information-Loaded and Negotiation-Oriented Tasks

    OpenAIRE

    Roya Khoii; Somaye Ashuri

    2016-01-01

    The present study aimed to investigate the effects of implementing two innovative speaking tasks, namely, information-loaded and negotiation-oriented tasks, on the incidental vocabulary acquisition of advanced Iranian EFL learners. To this end, an experimental research was conducted in an English language institute with 30 homogeneous advanced EFL learners randomly divided into two experimental groups. Experimental group I performed some information-loaded tasks using thirty five texts as spe...

  19. Central as well as peripheral attentional bottlenecks in dual-task performance activate lateral prefrontal cortices

    Directory of Open Access Journals (Sweden)

    Andre J Szameitat

    2016-03-01

    Full Text Available Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage as well as peripheral limitations (i.e., bottleneck at response initiation both demand executive functions located in the lateral prefrontal cortex. For this, we re-analysed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP during fMRI. In one study (N=17, the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group. In the other study (N=16, the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group. Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect. Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices. Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns suggest that the executive functions resolving

  20. IEA Wind Task 36 Forecasting

    Science.gov (United States)

    Giebel, Gregor; Cline, Joel; Frank, Helmut; Shaw, Will; Pinson, Pierre; Hodge, Bri-Mathias; Kariniotakis, Georges; Sempreviva, Anna Maria; Draxl, Caroline

    2017-04-01

    Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Wind Power Forecasting tries to organise international collaboration, among national weather centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, UK MetOffice, …) and operational forecaster and forecast users. The Task is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets for verification. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts aiming at industry and forecasters alike. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions, especially probabilistic ones. The Operating Agent is Gregor Giebel of DTU, Co-Operating Agent is Joel Cline of the US Department of Energy. Collaboration in the task is solicited from everyone interested in the forecasting business. We will collaborate with IEA Task 31 Wakebench, which developed the Windbench benchmarking platform, which this task will use for forecasting benchmarks. The task runs for three years, 2016-2018. Main deliverables are an up-to-date list of current projects and main project results, including datasets which can be used by researchers around the world to improve their own models, an IEA Recommended Practice on performance evaluation of probabilistic forecasts, a position paper regarding the use of probabilistic forecasts

  1. Number & operations task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the number & operations concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are problems involving place value, fractions, addition, subtraction and using money. The combined task & drill sheets offer spac

  2. Modelling the exposure of wildlife to radiation: key findings and activities of IAEA working groups

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, Nicholas A. [NERC Centre for Ecology and Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster, LA1 4AP (United Kingdom); School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Vives i Batlle, Jordi; Vandenhove, Hildegarde [Belgian Nuclear Research Centre, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Beaugelin-Seiller, Karine [Institut de Radioprotection et de Surete Nucleaire (IRSN), PRP-ENV, SERIS, LM2E, Cadarache (France); Johansen, Mathew P. [ANSTO Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Menai, NSW (Australia); Goulet, Richard [Canadian Nuclear Safety Commission, Environmental Risk Assessment Division, 280 Slater, Ottawa, K1A0H3 (Canada); Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Ruedig, Elizabeth [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins (United States); Stark, Karolina; Bradshaw, Clare [Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-10691 (Sweden); Andersson, Pal [Swedish Radiation Safety Authority, SE-171 16, Stockholm (Sweden); Copplestone, David [Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom); Yankovich, Tamara L.; Fesenko, Sergey [International Atomic Energy Agency, Vienna International Centre, 1400, Vienna (Austria)

    2014-07-01

    In total, participants from 14 countries, representing 19 organisations, actively participated in the model application/inter-comparison activities of the IAEA's EMRAS II programme Biota Modelling Group. A range of models/approaches were used by participants (e.g. the ERICA Tool, RESRAD-BIOTA, the ICRP Framework). The agreed objectives of the group were: 'To improve Member State's capabilities for protection of the environment by comparing and validating models being used, or developed, for biota dose assessment (that may be used) as part of the regulatory process of licensing and compliance monitoring of authorised releases of radionuclides.' The activities of the group, the findings of which will be described, included: - An assessment of the predicted unweighted absorbed dose rates for 74 radionuclides estimated by 10 approaches for five of the ICRPs Reference Animal and Plant geometries assuming 1 Bq per unit organism or media. - Modelling the effect of heterogeneous distributions of radionuclides in sediment profiles on the estimated exposure of organisms. - Model prediction - field data comparisons for freshwater ecosystems in a uranium mining area and a number of wetland environments. - An evaluation of the application of available models to a scenario considering radioactive waste buried in shallow trenches. - Estimating the contribution of {sup 235}U to dose rates in freshwater environments. - Evaluation of the factors contributing to variation in modelling results. The work of the group continues within the framework of the IAEA's MODARIA programme, which was initiated in 2012. The work plan of the MODARIA working group has largely been defined by the findings of the previous EMRAS programme. On-going activities of the working group, which will be described, include the development of a database of dynamic parameters for wildlife dose assessment and exercises involving modelling the exposure of organisms in the marine coastal

  3. COMPARATIVE STUDY BETWEEN TASK SPECIFIC MOTOR IMAGERY WITH MENTAL PRACTICE VERSUS TASK SPECIFIC MIRROR THERAPY ON UPPER LIMB FUNCTIONS FOR SUB ACUTE HEMIPLEGIA

    Directory of Open Access Journals (Sweden)

    Thara. N

    2015-10-01

    Full Text Available Background: Task specific training of upper limb may result in learning of new motor task through transfer after repeated practice. Mirror therapy and motor imagery are effective emerging techniques used as an adjunct in rehabilitation of upper limb function in hemiplegia. The purpose of the study is to find comparative effects of task specific motor imagery with mental practice over task specific mirror therapy on upper limb functional activities for subjects with sub acute hemiplegia. Method: An experimental study design with two groups conducted on 30 subjects with sub-acute hemiplegic. Thirty subjects randomised, 15 subjects into group A and 15 into group B. Group A subjects received task specific motor imagery with mental practice thrice a week for 10 weeks and Group B received task specific mirror therapy thrice a week for 10 weeks. In both groups, each session consisted of 60 minutes. The outcome measure such as Action Research Arm Test (ARAT was measured before and after 10 weeks of intervention. Results: Comparison of post intervention means of ARAT using Independent t test and Mann-Whitney Test showed that there is no statistically significant difference in grasp and gross movement between the groups and there is a statistically significant difference in grip, pinch and total score between the groups. Conclusion: The present study concludes that 10 weeks of task specific motor imagery with mental practice and task specific mirror therapy both shown significant effect on improvement of upper extremity function. However, greater percentage of improvement was found using task specific motor imagery with mental practice in hand function when compared to task specific mirror therapy.

  4. Nicotine reduces antisaccade errors in task impaired schizophrenic subjects.

    Science.gov (United States)

    Larrison-Faucher, Abigail L; Matorin, Anu A; Sereno, Anne B

    2004-05-01

    Nicotine and/or smoking have been shown to reduce various cognitive deficits associated with schizophrenia. Here, we examine the effects of nicotine gum on repeated performance on a simple eye movement task. Eight schizophrenic subjects and eight controls participated in three days of testing on saccade (S) and antisaccade (AS) tasks. On each testing day, subjects participated in four testing sessions and received both of two nicotine gum treatments (4 and 6 mg) and both of two control conditions (placebo gum and no gum), each followed by a recovery period. Overall, schizophrenics showed significant impairments on the AS task. However, upon individual examination only four schizophrenics showed significant differences in AS errors or reaction times (RTs) when compared to controls. The other four schizophrenic subjects showed control level performance. All schizophrenic subjects showed normal and better than control level performance on the simple S task. Furthermore, no effects of nicotine were seen on the simple S task. There were significant treatment effects on the AS task. Nicotine treatment significantly decreased errors in the task impaired schizophrenic group and this effect was most pronounced at the 6 mg level. No nicotine effects were demonstrated for non-impaired schizophrenic subjects or controls. This study demonstrates a benefit of short exposure to nicotine in cognitively impaired schizophrenic subjects. These results support previous findings of cognitive benefits of nicotine in schizophrenics.

  5. Dual task and postural control in Alzheimer's and Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Larissa Pires de Andrade

    2014-03-01

    Full Text Available Patients with neurodegenerative diseases are required to use cognitive resources while maintaining postural control. The aim of this study was to investigate the effects of a frontal cognitive task on postural control in patients with Alzheimer, Parkinson and controls. Thirty-eight participants were instructed to stand upright on a force platform in two experimental conditions: single and dual task. Participants with Parkinson's disease presented an increase in the coefficient of variation greater than 100% in the dual task as compared to the single task for center of pressure (COP area and COP path. In addition, patients with Parkinson's and Alzheimer's disease had a higher number of errors during the execution of the cognitive task when compared to the group of elderly without neurodegenerative diseases. The motor cortex, which is engaged in postural control, does not seem to compete with frontal brain regions in the performance of the cognitive task. However, patients with Parkinson's and Alzheimer's disease presented worsened performance in cognitive task.

  6. Informal groups

    NARCIS (Netherlands)

    E. van den Berg; P. van Houwelingen; J. de Hart

    2011-01-01

    Original title: Informele groepen Going out running with a group of friends, rather than joining an official sports club. Individuals who decide to take action themselves rather than giving money to good causes. Maintaining contact with others not as a member of an association, but through an Inter

  7. Anxiety, emotional distraction, and attentional control in the Stroop task.

    Science.gov (United States)

    Kalanthroff, Eyal; Henik, Avishai; Derakshan, Nazanin; Usher, Marius

    2016-04-01

    Using a Stroop task, we investigated the effect of task-irrelevant emotional distractors on attentional proactive control and its interaction with trait anxiety. On the basis of recent findings showing opposed neural responses in the dorsal-executive versus the ventral-emotional systems in response to emotional distractors and of the attentional control theory (Eysenck, Derakshan, Santos, & Calvo, 2007), we hypothesized that negative distractors will result in a reduction of proactive task control in the executive system, especially for high-trait-anxious individuals. Using a computational model of the Stroop task, we derive 2 specific behavioral predictions of reduced proactive task control: increased Stroop interference and reversed Stroop facilitation. Twenty-five high- and 25 low-trait-anxious participants completed a Stroop task in which the target stimuli were preceded by brief (neutral vs. aversive) emotional distractors. While no effects of picture valence on proactive control was found in the low-anxious group, the predicted signatures of reduced proactive control were observed in the high-anxiety group. These results indicate that trait anxiety influences the interaction between irrelevant emotional stimuli and proactive control.

  8. Game elements improve performance in a working memory training task

    Directory of Open Access Journals (Sweden)

    Manuel Ninaus

    2015-02-01

    Full Text Available The utilization of game elements in a non-game context is currently used in a vast range of different domains. However, research on game elements’ effects in cognitive tasks is still sparse. Thus, in this study we implemented three game elements, namely, progress bar, level indicator, and a thematic setting, in a working memory training task. We evaluated the impact of game elements on user performance and perceived state of flow when compared to a conventional version of the task. Participants interacting with game elements showed higher scores in the working memory training task than participants from a control group who completed the working memory training task without the game elements. Moreover, game elements facilitated the individuals’ performance closer to their maximum working memory capacity. Finally, the perceived flow did not differ between the two groups, which indicates that game elements can induce better performance without changing the perception of being “in the zone”, that is without an increase in anxiety or boredom. This empirical study indicates that certain game elements can improve the performance and efficiency in a working memory task by increasing users’ ability and willingness to train at their optimal performance level. 

  9. Compensatory mechanisms underlie intact task-switching performance in schizophrenia.

    Science.gov (United States)

    Jamadar, S; Michie, P; Karayanidis, F

    2010-04-01

    Individuals with schizophrenia tend to perform poorly on many measures of cognitive control. However, recent task-switching studies suggest that they show intact task-switching performance, despite the fact that the regions involved in task-switching are known to be structurally and functionally impaired in the disorder. Behavioral, event-related potential (ERP) and functional magnetic resonance imaging (fMRI) measures were used to compare the temporal and spatial dynamics of task-switching performance in individuals with schizophrenia and controls. Consistent with previous studies, reaction time (RT) switch cost and its reduction with anticipatory preparation did not differ between groups. There were also no group differences on cue-locked ERP components associated with anticipatory preparation processes. However, both stimulus- and response-locked ERPs were significantly disrupted in schizophrenia, suggesting difficulty with task-set implementation. fMRI analyses indicated that individuals with schizophrenia showed hyperactivity in the dorsolateral prefrontal cortex and posterior parietal cortex. RT-fMRI and ERP-fMRI associations suggested that individuals with schizophrenia employ compensatory mechanisms to overcome difficulties in task-set implementation and thereby achieve the same behavioral outcomes as controls.

  10. International Energy Agency Ocean Energy Systems Task 10 Wave Energy Converter Modeling Verification and Validation

    DEFF Research Database (Denmark)

    Wendt, Fabian F.; Yu, Yi-Hsiang; Nielsen, Kim

    2017-01-01

    This is the first joint reference paper for the Ocean Energy Systems (OES) Task 10 Wave Energy Converter modeling verification and validation group. The group is established under the OES Energy Technology Network program under the International Energy Agency. OES was founded in 2001 and Task 10 ...

  11. The Task Manager for the LHCb On-Line Farm

    CERN Document Server

    Bonifazi, F; Carbone, A; Galli, D; Gregori, D; Marconi, U; Peco, G; Vagnoni, V

    2004-01-01

    The Task Manager is a utility to start, stop and list processes on the on-line farm. Each process started by the Task Manager has a string environment variable set, named UTGID (User defined unique Thread Group Identifier) which allows to identify the process. The Task Manager uses the UTGID to list the running processes and to identify the processes to be stopped. It has also the ability to start a process using a particular user name and to set the scheduler type and the priority for the process itself. The Task Manager package includes a Linux DIM server (tmSrv), four Linux command line DIM clients (tmStart, tmLs, tmKill and tmStop) and a JCOP (Joint Control Project) PVSS client.

  12. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  13. Scientists and the Selection Task.

    Science.gov (United States)

    Griggs, Richard A.; Ransdell, Sarah E.

    1986-01-01

    Presents findings of a study of scientists on the Wason four-card selection task, finding little understanding of the effect of disconfirmatory data in assessing conditionals. Found performance influenced by problem content. Explains performance as memory-cueing plus reasoning-by-analogy. (JM)

  14. Computer-Related Task Performance

    DEFF Research Database (Denmark)

    Longstreet, Phil; Xiao, Xiao; Sarker, Saonee

    2016-01-01

    The existing information system (IS) literature has acknowledged computer self-efficacy (CSE) as an important factor contributing to enhancements in computer-related task performance. However, the empirical results of CSE on performance have not always been consistent, and increasing an individua...

  15. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  16. Use cases versus task descriptions

    DEFF Research Database (Denmark)

    Lauesen, Søren; Kuhail, Mohammad Amin

    2011-01-01

    to specify require-ments for the same project: Acquire a new system to support a hotline. [Princi-pal ideas/results] Among the 15 replies, eight used traditional use cases that specified a dialog between users and system. Seven used a related technique, task description, which specified the customer's needs...

  17. Task-Based Writing Instruction

    Science.gov (United States)

    Bantis, Alexandros

    2010-01-01

    The purpose of this study was to investigate the impact of task-based writing instruction, a communicative language-teaching method, on second language acquisition and differentiation of instruction for English language learners during the independent work time instructional component of the Open Court Reading program. Through student-teacher…

  18. On the Tasks of Translation

    Institute of Scientific and Technical Information of China (English)

    王晓菊

    2012-01-01

      Many linguists, translators, and theorists have been arguing over the approaches on translation. While putting these into use a translator may experience many pleasure and problems as well. The purpose of this article is to discuss the tasks of translation and the way of choosing the proper translation approaches according to the author’s own experience of practice.

  19. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group, established at the start of 2010, has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure There are now 55 CMS Centres worldwide that are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS offline and computing operations, hosting dedicated analysis efforts such as during the CMS Heavy Ion lead-lead running. With a majority of CMS sub-detectors now operating in a “shifterless” mode, many monitoring operations are now routinely performed from there, rather than in the main Control Room at P5. The CMS Communications Group, CERN IT and the EVO team are providing excellent videoconferencing support for the rapidly-increasing number of CMS meetings. In parallel, CERN IT and ...

  20. Lego Group

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Pedersen, Torben; Slepniov, Dmitrij

    2010-01-01

    The last years’ rather adventurous journey from 2004 to 2009 had taught the fifth-largest toy-maker in the world - the LEGO Group - the importance of managing the global supply chain effectively. In order to survive the largest internal financial crisis in its roughly 70 years of existence......, the management had, among many initiatives, decided to offshore and outsource a major chunk of its production to Flextronics. In this pursuit of rapid cost-cutting sourcing advantages, the LEGO Group planned to license out as much as 80 per cent of its production besides closing down major parts...... of the production in high cost countries. Confident with the prospects of the new partnership, the company signed a long-term contract with Flextronics. This decision eventually proved itself to have been too hasty, however. Merely three years after the contracts were signed, LEGO management announced that it would...

  1. Group play

    DEFF Research Database (Denmark)

    Tychsen, Anders; Hitchens, Michael; Brolund, Thea

    2008-01-01

    of group dynamics, the influence of the fictional game characters and the comparative play experience between the two formats. The results indicate that group dynamics and the relationship between the players and their digital characters, are integral to the quality of the gaming experience in multiplayer......Role-playing games (RPGs) are a well-known game form, existing in a number of formats, including tabletop, live action, and various digital forms. Despite their popularity, empirical studies of these games are relatively rare. In particular there have been few examinations of the effects...... of the various formats used by RPGs on the gaming experience. This article presents the results of an empirical study, examining how multi-player tabletop RPGs are affected as they are ported to the digital medium. Issues examined include the use of disposition assessments to predict play experience, the effect...

  2. The Validity of Grammaticality Judgment Task on Saudi EFL Learners

    Directory of Open Access Journals (Sweden)

    Sami Alanazi

    2015-11-01

    Full Text Available The purpose of this paper is to shed light on the validity of the controversial data-gathering tool Grammaticality Judgment Task on measuring the grammatical competency of Saudi EFL learners. Despite the widespread use of GJT in SLA research, it is surrounded by a great deal of criticism. The present paper is part of a larger study investigating the acquisition of past verb forms by Saudi EFL learners. Thirty-six Saudi EFL learners took part in the study and were divided into three groups as follows: guided-planning group, semi-guided planning group, and control group. The task used in the study consisted of twenty test items: 10 control test items, and 10 experimental test items. The results did not reveal significant statistical differences between the three groups. Also, the results did not reflect the actual grammatical competency of the participants.

  3. Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

    Directory of Open Access Journals (Sweden)

    David M Sanbonmatsu

    Full Text Available The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

  4. The Importance of Context in Task Selection

    Science.gov (United States)

    Weiland, Travis

    2017-01-01

    Context is at the core of any statistical investigation, yet many statistics tasks barely require students to go beyond superficial consideration of the contexts the tasks are situated in. In this article, I discuss a framework for evaluating the level of interaction with context a task requires of students and how to modify tasks to increase the…

  5. Tasks for Easily Modifiable Virtual Environments

    Science.gov (United States)

    Swier, Robert

    2014-01-01

    Recent studies of learner interaction in virtual worlds have tended to select basic tasks involving open-ended communication. There is evidence that such tasks are supportive of language acquisition, however it may also be beneficial to consider more complex tasks. Research in task-based learning has identified features such as non-linguistic…

  6. Cosmetology: Task Analyses. Competency-Based Education.

    Science.gov (United States)

    Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum Center.

    These task analyses are designed to be used in combination with the "Trade and Industrial Education Service Area Resource" in order to implement competency-based education in the cosmetology program in Virginia. The task analysis document contains the task inventory, suggested task sequence lists, and content outlines for the secondary…

  7. The Importance of Context in Task Selection

    Science.gov (United States)

    Weiland, Travis

    2017-01-01

    Context is at the core of any statistical investigation, yet many statistics tasks barely require students to go beyond superficial consideration of the contexts the tasks are situated in. In this article, I discuss a framework for evaluating the level of interaction with context a task requires of students and how to modify tasks to increase the…

  8. Priming in word stem completion tasks: comparison with previous results in word fragment completion tasks.

    Science.gov (United States)

    Soler, María J; Dasí, Carmen; Ruiz, Juan C

    2015-01-01

    This study investigates priming in an implicit word stem completion (WSC) task by analyzing the effect of linguistic stimuli characteristics on said task. A total of 305 participants performed a WSC task in two phases (study and test). The test phase included 63 unique-solution stems and 63 multiple-solution stems. Analysis revealed that priming (mean = 0.22) was stronger in the case of multiple-solution stems, indicating that they were not a homogeneous group of stimuli. Thus, further analyses were performed only for the data of the unique-solution stems. Correlations between priming and familiarity, frequency of use, and baseline completion were significant. The less familiar words, which were less frequent, had higher priming values. At the same time, the stems with lower baseline completion generated more priming. A regression analysis showed that baseline completion was the only significant predictor of priming, suggesting that the previous processing of the stimuli had a greater impact on the stimuli with low baseline performance. At the same time, baseline completion showed significant positive correlations with familiarity and frequency of use, and a negative correlation with length. When baseline completion was the dependent variable in the regression analysis, the significant variables in the regression were familiarity and length. These results were compared with those obtained in a study using word fragment completion (WFC) by Soler et al. (2009), in which the same words and procedure were employed. Analysis showed that the variables that correlated with priming were the same as in the WSC task, and that completion baseline was the variable that showed the greatest predictive power of priming. This coincidence of results obtained with WFC and WSC tasks highlights the importance of controlling the characteristics of the stimuli used when exploring the nature of priming.

  9. Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke

    Science.gov (United States)

    Rosenfeldt, Anson B.; Dey, Tanujit; Alberts, Jay L.

    2017-01-01

    OBJECTIVE. To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice. METHOD. Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only. RESULTS. Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice–only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement. CONCLUSION. People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice. PMID:28218596

  10. Dual-Task Interference: The Effects of Verbal Cognitive Tasks on Upright Postural Stability in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    J. D. Holmes

    2010-01-01

    Full Text Available Although dual-task interference has previously been demonstrated to have a significant effect on postural control among individuals with Parkinson's disease, the impact of speech complexity on postural control has not been demonstrated using quantitative biomechanical measures. The postural stability of twelve participants with idiopathic Parkinson's disease and twelve healthy age-matched controls was evaluated under three conditions: (1 without a secondary task, (2 performing a rote repetition task and (3 generating a monologue. Results suggested a significant effect of cognitive load on biomechanical parameters of postural stability. Although both groups increased their postural excursion, individuals with Parkinson's disease demonstrated significantly reduced excursion as compared with that of healthy age-matched controls. This suggests that participants with Parkinson's disease may be overconstraining their postural adjustments in order to focus attention on the cognitive tasks without losing their balance. Ironically, this overconstraint may place the participant at greater risk for a fall.

  11. Group Connections: Whole Group Teaching.

    Science.gov (United States)

    Griffiths, Dorothy

    2002-01-01

    A learner-centered approach to adult group instruction involved learners in investigating 20th-century events. The approach allowed learners to concentrate on different activities according to their abilities and gave them opportunities to develop basic skills and practice teamwork. (SK)

  12. Visual Motor and Perceptual Task Performance in Astigmatic Students

    Directory of Open Access Journals (Sweden)

    Erin M. Harvey

    2017-01-01

    Full Text Available Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D or bilateral astigmatism group (right and left eye ≥ 1.00 D based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI and Visual Perception (VMIp. Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88. Mean VMI score in corrected astigmats did not differ from the control group (p=0.829. Uncorrected astigmats had lower VMI scores than the control group (p=0.038 and corrected astigmats (p=0.007. Mean VMIp scores for uncorrected (p=0.209 and corrected astigmats (p=0.124 did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p=0.003. Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

  13. Declarative and nondeclarative sequence learning tasks: closed-head injured patients versus control participants.

    Science.gov (United States)

    Vakil, E; Gordon, Y; Birnstok, S; Aberbuch, S; Groswasser, Z

    2001-04-01

    Patients who sustained closed-head injury (CHI) have been shown to have impaired memory for temporal order when measured under intentional, but not incidental, retrieval conditions. A group of 26 patients who sustained CHI and a matched control group of 26 individuals were tested on a declarative sequence learning task--"Chain Making" (CM), and a nondeclarative sequence learning task--Tower of Hanoi puzzle (TOHP). The TOHP is a problem solving task that requires planning and a strategic approach. The latter are cognitive processes known to be impaired following frontal lobe damage, as has been frequently documented in CHI patients. The goal of the present study was to test whether CHI patients' nondeclarative learning as measured by the TOHP task is preserved, as seen in amnesic patients, or impaired, as would be predicted following frontal lobe damage. Half of the participants in each group underwent active training, and the other half went through passive training of the tasks. The results demonstrate that the control group outperformed the CHI group (in most measures) in both declarative and nondeclarative sequence learning tasks. The effect of type of training differed for the two tasks: while performance of the control group on the TOHP was better under passive training (CHI patients did not improve on either one of the training modes), performance on the CM task was better under active training for both groups. The results are discussed in light of the role of the frontal lobes in memory generally, and in sequence learning particularly.

  14. Task-independent effects are potential confounders in longitudinal imaging studies of learning in schizophrenia.

    Science.gov (United States)

    Korostil, Michele; Fatima, Zainab; Kovacevic, Natasha; Menon, Mahesh; McIntosh, Anthony Randal

    2016-01-01

    Learning impairment is a core deficit in schizophrenia that impacts on real-world functioning and yet, elucidating its underlying neural basis remains a challenge. A key issue when interpreting learning-task experiments is that task-independent changes may confound interpretation of task-related signal changes in neuroimaging studies. The nature of these task-independent changes in schizophrenia is unknown. Therefore, we examined task-independent "time effects" in a group of participants with schizophrenia contrasted with healthy participants in a longitudinal fMRI learning-experiment designed to allow for examination of non-specific effects of time. Flanking the learning portions of the experiment with a task-of-no-interest allowed us to extract task-independent BOLD changes. Task-independent effects occurred in both groups, but were more robust in the schizophrenia group. There was a significant interaction effect between group and time in a distributed activity pattern that included inferior and superior temporal regions, frontal areas (left anterior insula and superior medial gyri), and parietal areas (posterior cingulate cortices and precuneus). This pattern showed task-independent linear decrease in BOLD amplitude over the two scanning sessions for the schizophrenia group, but showed either opposite effect or no activity changes for the control group. There was a trend towards a correlation between task-independent effects and the presence of more negative symptoms in the schizophrenia group. The strong interaction between group and time suggests that both the scanning experience as a whole and the transition between task-types evokes a different response in persons with schizophrenia and may confound interpretation of learning-related longitudinal imaging experiments if not explicitly considered.

  15. Task-independent effects are potential confounders in longitudinal imaging studies of learning in schizophrenia

    Science.gov (United States)

    Korostil, Michele; Fatima, Zainab; Kovacevic, Natasha; Menon, Mahesh; McIntosh, Anthony Randal

    2015-01-01

    Learning impairment is a core deficit in schizophrenia that impacts on real-world functioning and yet, elucidating its underlying neural basis remains a challenge. A key issue when interpreting learning-task experiments is that task-independent changes may confound interpretation of task-related signal changes in neuroimaging studies. The nature of these task-independent changes in schizophrenia is unknown. Therefore, we examined task-independent “time effects” in a group of participants with schizophrenia contrasted with healthy participants in a longitudinal fMRI learning-experiment designed to allow for examination of non-specific effects of time. Flanking the learning portions of the experiment with a task-of-no-interest allowed us to extract task-independent BOLD changes. Task-independent effects occurred in both groups, but were more robust in the schizophrenia group. There was a significant interaction effect between group and time in a distributed activity pattern that included inferior and superior temporal regions, frontal areas (left anterior insula and superior medial gyri), and parietal areas (posterior cingulate cortices and precuneus). This pattern showed task-independent linear decrease in BOLD amplitude over the two scanning sessions for the schizophrenia group, but showed either opposite effect or no activity changes for the control group. There was a trend towards a correlation between task-independent effects and the presence of more negative symptoms in the schizophrenia group. The strong interaction between group and time suggests that both the scanning experience as a whole and the transition between task-types evokes a different response in persons with schizophrenia and may confound interpretation of learning-related longitudinal imaging experiments if not explicitly considered. PMID:26759790

  16. Thrive or overload? The effect of task complexity on novices' simulation-based learning.

    Science.gov (United States)

    Haji, Faizal A; Cheung, Jeffrey J H; Woods, Nicole; Regehr, Glenn; de Ribaupierre, Sandrine; Dubrowski, Adam

    2016-09-01

    Fidelity is widely viewed as an important element of simulation instructional design based on its purported relationship with transfer of learning. However, higher levels of fidelity may increase task complexity to a point at which novices' cognitive resources become overloaded. In this experiment, we investigate the effects of variations in task complexity on novices' cognitive load and learning during simulation-based procedural skills training. Thirty-eight medical students were randomly assigned to simulation training on a simple or complex lumbar puncture (LP) task. Participants completed four practice trials on this task (skill acquisition). After 10 days of rest, all participants completed one additional trial on their assigned task (retention) and one trial on a 'very complex' simulation designed to be similar to the complex task (transfer). We assessed LP performance and cognitive load on each trial using multiple measures. In both groups, LP performance improved significantly during skill acquisition (p ≤ 0.047, f = 0.29-0.96) and was maintained at retention. The simple task group demonstrated superior performance compared with the complex task group throughout these phases (p ≤ 0.002, d = 1.13-2.31). Cognitive load declined significantly in the simple task group (p task group during skill acquisition, and remained lower at retention (p ≤ 0.024, d = 0.78-1.39). Between retention and transfer, LP performance declined and cognitive load increased in the simple task group, whereas both remained stable in the complex task group. At transfer, no group differences were observed in LP performance and cognitive load, except that the simple task group made significantly fewer breaches of sterility (p = 0.023, d = 0.80). Reduced task complexity was associated with superior LP performance and lower cognitive load during skill acquisition and retention, but mixed results on transfer to a more complex task. These results indicate that task

  17. Task allocation in a distributed computing system

    Science.gov (United States)

    Seward, Walter D.

    1987-01-01

    A conceptual framework is examined for task allocation in distributed systems. Application and computing system parameters critical to task allocation decision processes are discussed. Task allocation techniques are addressed which focus on achieving a balance in the load distribution among the system's processors. Equalization of computing load among the processing elements is the goal. Examples of system performance are presented for specific applications. Both static and dynamic allocation of tasks are considered and system performance is evaluated using different task allocation methodologies.

  18. Evolution of Task Partitioning in Swarm Robotics

    OpenAIRE

    Ferrante, Eliseo,; Duenez-Guzman, E.; Turgut, A. E.; Wenseleers, Tom

    2013-01-01

    International audience; Task-partitioning refers to the process whereby a task is divided into two or more sub-tasks. Through task partitioning both efficiency and effectiveness can be improved provided the right environmental conditions. We synthesize self-organized task partitioning behaviors for a swarm of mobile robots using artificial evolution. Through validation experiments, we show that the synthesized behaviors exploits behavioral specialization despite being based on homogeneous ind...

  19. Individual Differences in Secondary Task Performance.

    Science.gov (United States)

    1980-09-01

    task similar to that used by Atkinson and Shiffrin (1968). The spatial task in- volved holding in memory a random pattern of plus signs. In all cases...may serve to attenuate the easy-to-hard correlation. I *1,~ __ __ _ Secondary Task Performance 33 References Atkinson , R. C., & Shiffrin , R. M. Human...aIde if nec.eaar, and Identify by block number) ability, attention, dual task, information processing, individual differences memory , secondary task

  20. Incidental Vocabulary Learning Through Information-Loaded and Negotiation-Oriented Tasks

    Directory of Open Access Journals (Sweden)

    Roya Khoii

    2016-11-01

    Full Text Available The present study aimed to investigate the effects of implementing two innovative speaking tasks, namely, information-loaded and negotiation-oriented tasks, on the incidental vocabulary acquisition of advanced Iranian EFL learners. To this end, an experimental research was conducted in an English language institute with 30 homogeneous advanced EFL learners randomly divided into two experimental groups. Experimental group I performed some information-loaded tasks using thirty five texts as speaking aids for implementing multicultural experiences, and experimental group II performed some negotiation-oriented tasks utilizing seven argumentative sentences for each topic to promote divergent thinking processes. At the end of the treatment, a vocabulary post-test and a questionnaire were administered to measure the effects of the treatments on the students’ incidental vocabulary knowledge and attitude to the performed tasks in each group. The statistical analysis of the data revealed that the information-loaded tasks group had significantly outperformed the negotiation-oriented tasks group on the vocabulary post-test and had a significantly more positive attitude to the tasks they performed in their class. This study offers some implications for the development of a sizable and profound knowledge of vocabulary in an effortless and pleasant manner. It also fulfils the need of EFL teachers and material developers in their search for some effective activities and techniques that can help to improve EFL learners’ incidental vocabulary knowledge. Keywords: Incidental vocabulary learning; Information-gap tasks; Information-loaded tasks; Negotiation-oriented tasks; Opinion-gap tasks

  1. Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study.

    Science.gov (United States)

    Fernandes, Ângela; Rocha, Nuno; Santos, Rubim; Tavares, João Manuel R S

    2015-01-01

    The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

  2. Can task-switching training enhance executive control functioning in children with attention deficit/-hyperactivity disorder?

    Directory of Open Access Journals (Sweden)

    Jutta eKray

    2012-01-01

    Full Text Available The key cognitive impairments of children with attention deficit/-hyperactivity disorder (ADHD include executive control functions such as inhibitory control, task switching, and working memory. In this training study we examined whether task-switching training leads to improvements in these functions. Twenty children with combined type ADHD and stable methylphenidate medication performed a single-task and a task-switching training in a crossover training design. The children were randomly assigned to one of two groups. One group started with the single-task training and then performed the task-switching training and the other group vice versa. The effectiveness of the task-switching training was measured as performance improvements (relative to the single-task training on a structurally similar but new switching task and on other executive control tasks measuring inhibitory control and verbal working memory as well as on fluid intelligence (reasoning. The children in both groups showed improvements in task switching, that is, a reduction of switching costs, but not in performing the single tasks across four training sessions. Moreover, the task-switching training lead to selective enhancements in task-switching performance, that is, the reduction of task-switching costs was found to be larger after task-switching than after single-task training. Similar selective improvements were observed for inhibitory control and verbal working memory, but not for reasoning. Results of this study suggest that task-switching training is an effective cognitive intervention that helps to enhance executive control functioning in children with ADHD.

  3. Multi-robot Task Allocation for Search and Rescue Missions

    Science.gov (United States)

    Hussein, Ahmed; Adel, Mohamed; Bakr, Mohamed; Shehata, Omar M.; Khamis, Alaa

    2014-12-01

    Many researchers from academia and industry are attracted to investigate how to design and develop robust versatile multi-robot systems by solving a number of challenging and complex problems such as task allocation, group formation, self-organization and much more. In this study, the problem of multi-robot task allocation (MRTA) is tackled. MRTA is the problem of optimally allocating a set of tasks to a group of robots to optimize the overall system performance while being subjected to a set of constraints. A generic market-based approach is proposed in this paper to solve this problem. The efficacy of the proposed approach is quantitatively evaluated through simulation and real experimentation using heterogeneous Khepera-III mobile robots. The results from both simulation and experimentation indicate the high performance of the proposed algorithms and their applicability in search and rescue missions.

  4. Field dependence and stimulus complexity in a figure copying task.

    Science.gov (United States)

    Coté, Carol A; O'Donnell, Angela M

    2007-12-01

    Field dependence is often associated with studies of cognitive style from Witkin's laboratory but Piaget also considered the concept a fundamental factor in the development of visuoperceptual analysis. Assessment has traditionally relied on two measures, the Rod-and-Frame Test and the Embedded Figures Test. A new task was developed, based on the Rod-and-Frame Test, in which a target stimulus is drawn within a misleading frame. Misleading frames significantly influenced the orientation of drawings created by 36 kindergartners in Exp. 1, and the drawing of more complex stimulus figures was influenced by the frames for a group of 65 adults in Exp. 2. Field-dependent behavior is related to the complexity of the task and to age. The correlation of scores on the Embedded Figures Test with performance on this task was low for both groups.

  5. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2011-01-01

    The CMS Communications Group has been busy in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The 55 CMS Centres worldwide are well used by physicists working on remote CMS shifts, Computing operations, data quality monitoring, data analysis and outreach. The CMS Centre@CERN in Meyrin, is the centre of the CMS Offline and Computing operations, and a number of subdetector shifts can now take place there, rather than in the main Control Room at P5. A new CMS meeting room has been equipped for videoconferencing in building 42, next to building 40. Our building 28 meeting room and the facilities at P5 will be refurbished soon and plans are underway to steadily upgrade the ageing equipment in all 15 CMS meeting rooms at CERN. The CMS evaluation of the Vidyo tool indicates that it is not yet ready to be considered as a potential replacement for EVO. The Communications Group provides the CMS-TV (web) cha...

  6. COMMUNICATIONS GROUP

    CERN Multimedia

    L. Taylor

    2010-01-01

    The CMS Communications Group, established at the start of 2010, has been strengthening the activities in all three areas of its responsibility: (1) Communications Infrastructure, (2) Information Systems, and (3) Outreach and Education. Communications Infrastructure The Communications Group has invested a lot of effort to support the operations needs of CMS. Hence, the CMS Centres where physicists work on remote CMS shifts, Data Quality Monitoring, and Data Analysis are running very smoothly. There are now 55 CMS Centres worldwide, up from just 16 at the start of CMS data-taking. The latest to join are Imperial College London, the University of Iowa, and the Università di Napoli. The CMS Centre@CERN in Meyrin, which is now full repaired after the major flooding at the beginning of the year, has been at the centre of CMS offline and computing operations, most recently hosting a large fraction of the CMS Heavy Ion community during the lead-lead run. A number of sub-detector shifts can now take pla...

  7. Reliability of novel postural sway task test

    Directory of Open Access Journals (Sweden)

    Milan Sedliak

    2013-07-01

    Full Text Available The purpose of this study was to examine the reliability of parameters obtained from a novel postural sway task test based on body movements controlled by visual feedback. Fifty-nine volunteers were divided into two groups. The first group consisted of young (n = 32, 16 females and 16 males, age: 25.2 ± 3.4 years and the second group of elderly individuals (n = 27, 17 females and 10 males, age: 75.7 ± 6.9 years. Participants stood in parallel on a computer based stabilographic platform with the feet approximately a shoulder width apart, the toes slightly pointing outwards, the hands placed on the hips. The computer screen was placed approximately 1.5 meter from the platform at a height of subjects’ eyes. An instantaneous visual feedback of participant’s centre of pressure (COP was given in a form of a blue cross visible on the screen. Participants were instructed to keep the blue cross driven by movements of their hips as close as possible to a predefined curve flowing on the screen. Out of the 6 parameters studied, only the average distance of COP from the curve line and the sum of the COP crossings through the curve line showed high reliability. Correlation between these two highly reliable parameters was -0.89. There was also a statistical difference (p<0.001 between young and elderly in both the average distance of COP from the curve line and the sum of the COP crossings through the curve. To conclude, the novel postural sway task provides a simple tool with relatively low time burden needed for testing. The suggested output parameters measured are highly reliable and easy to interpret.

  8. Framing Effects: Dynamics and Task Domains

    Science.gov (United States)

    Wang

    1996-11-01

    The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life-death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life-death choice problems than facing the counterpart problems presented in the other two task domains. Subjects' risk preference varied categorically along the group size dimension in the life-death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame-risk aversion and negative frame-risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. A bidirectional framing effect involves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, a unidirectional framing effect refers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable

  9. Novel Peritonsillar Abscess Task Simulator.

    Science.gov (United States)

    Taylor, Steven R; Chang, C W David

    2014-07-01

    The management of peritonsillar abscesses is a skill developed early in residency training. Although drainage is not technically complicated, the procedure is intimidating to the neophyte. Task simulators have become increasingly common to provide training opportunities in a controlled environment. The authors designed a peritonsillar abscess simulator using a latex moulage of the oral cavity and other common materials. Twelve medical professionals of various levels of experience were instructed to expose, anesthetize, aspirate, and drain the simulated abscess. After completion, a questionnaire was completed by each volunteer. Initial impressions were positive that the model adequately replicated the tasks requisite for abscess drainage and was suitable as an instructional device. The initial construct cost was approximately 10 dollars, with disposables costing roughly 25 cents. Further research is under way to formally assess the simulator for face, content, and construct validity.

  10. Computer task performance by subjects with Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Malheiros SRP

    2015-12-01

    Full Text Available Silvia Regina Pinheiro Malheiros,1 Talita Dias da Silva,2 Francis Meire Favero,2 Luiz Carlos de Abreu,1 Felipe Fregni,3 Denise Cardoso Ribeiro,4 Carlos Bandeira de Mello Monteiro1,4,5 1School of Medicine of ABC, Santo Andre, Brazil; 2Department of Medicine, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil; 3Center for Neurosciences, University of São Paulo, São Paulo, Brazil; 4Post-graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of São Paulo, São Paulo, Brazil; 5School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil Aims: Two specific objectives were established to quantify computer task performance among people with Duchenne muscular dystrophy (DMD. First, we compared simple computational task performance between subjects with DMD and age-matched typically developing (TD subjects. Second, we examined correlations between the ability of subjects with DMD to learn the computational task and their motor functionality, age, and initial task performance.Method: The study included 84 individuals (42 with DMD, mean age of 18±5.5 years, and 42 age-matched controls. They executed a computer maze task; all participants performed the acquisition (20 attempts and retention (five attempts phases, repeating the same maze. A different maze was used to verify transfer performance (five attempts. The Motor Function Measure Scale was applied, and the results were compared with maze task performance.Results: In the acquisition phase, a significant decrease was found in movement time (MT between the first and last acquisition block, but only for the DMD group. For the DMD group, MT during transfer was shorter than during the first acquisition block, indicating improvement from the first acquisition block to transfer. In addition, the TD group showed shorter MT than the DMD group across the study.Conclusion: DMD participants improved their performance after practicing

  11. Measuring Multi-tasking Ability

    Science.gov (United States)

    2003-07-01

    research. Table 2. Candidate MT Jobs Emergency Room Nurse Emergency Medical Technician Emergency Room Physician Intensive Care Nurse Floor Nurse Waitress ...the ICU and floor nurses, chefs, Army combat leaders, LCAC Craftmasters and LCAC Navigators who educated us about multi- tasking in the working world...different for intensive care nurses than for floor nurses. Hence, individuals were interviewed who had performed a variety of food preparation

  12. Visual Motor and Perceptual Task Performance in Astigmatic Students.

    Science.gov (United States)

    Harvey, Erin M; Twelker, J Daniel; Miller, Joseph M; Leonard-Green, Tina K; Mohan, Kathleen M; Davis, Amy L; Campus, Irene

    2017-01-01

    Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism VMI) and Visual Perception (VMIp). Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88). Mean VMI score in corrected astigmats did not differ from the control group (p = 0.829). Uncorrected astigmats had lower VMI scores than the control group (p = 0.038) and corrected astigmats (p = 0.007). Mean VMIp scores for uncorrected (p = 0.209) and corrected astigmats (p = 0.124) did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p = 0.003). Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

  13. 78 FR 63208 - UPDATE-Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-10-23

    ... Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of... Force (Task Force). The in-person Task Force meeting is being replaced by an abbreviated conference call... necessary scientific and logistical support for the meeting. The Task Force is an independent,......

  14. 78 FR 2996 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-01-15

    ... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health... Prevention (CDC) announces the next meeting of the Community Preventive Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally known leaders in public...

  15. 77 FR 56845 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2012-09-14

    ... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health... Prevention (CDC) announces the next meeting of the Community Preventive Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally known leaders in public...

  16. 78 FR 59939 - Meeting of the Community Preventive Services Task Force (Task Force)

    Science.gov (United States)

    2013-09-30

    ... Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention (CDC), Department of Health..., announcing the next meeting of the Community Preventive Services Task Force (Task Force). The document did... inability to attend the Task Force meeting due to the strict security regulations on federal...

  17. Learner-Learner Interaction during Collaborative Pragmatic Tasks: The Role of Cognitive and Pragmatic Task Demands

    Science.gov (United States)

    Kim, YouJin; Taguchi, Naoko

    2016-01-01

    Previous task complexity studies have suggested that learners produce more negotiation of meaning opportunities during complex tasks than simple tasks (Robinson, 2011). The present study builds on the existing task complexity literature by examining the impact of task complexity and pragmatic situational demands on the number of learning…

  18. What makes a 'good group'? Exploring the characteristics and performance of undergraduate student groups.

    Science.gov (United States)

    Channon, S B; Davis, R C; Goode, N T; May, S A

    2017-03-01

    Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a 'good group' through considering three aspects of group success: the task, the individuals, and the team. We employed a mixed methodology, combining demographic data with qualitative observations and task and peer evaluation scores. We determined associations between group dynamic and behaviour, demographic composition, member personalities and attitudes towards one another, and task success. We also employed a cluster analysis to create a model outlining the attributes of a good small group learning team in veterinary education. This model highlights that student groups differ in measures of their effectiveness as teams, independent of their task performance. On the basis of this, we suggest that groups who achieve high marks in tasks cannot be assumed to have acquired team working skills, and therefore if these are important as a learning outcome, they must be assessed directly alongside the task output.

  19. What would you do? The effect of verbal persuasion on task choice.

    Science.gov (United States)

    Lamarche, Larkin; Gionfriddo, Alicia M; Cline, Lindsay E; Gammage, Kimberley L; Adkin, Allan L

    2014-01-01

    Verbal persuasion has been shown to influence psychological and behavioral outcomes. The present study had two objectives: (1) to examine the effect of verbal persuasion on task choice in a balance setting and (2) to evaluate the use of verbal persuasion as an approach to experimentally induce mismatches between perceived and actual balance. Healthy young adults (N=68) completed an 8-m tandem walk task without vision and then were randomly assigned to a feedback group (good, control, or poor), regardless of actual balance. Following the feedback, participants chose to perform the task in one of three conditions differing in level of challenge and also were required to perform the task under the same pre-feedback conditions. Balance efficacy and perceived stability were rated before and after each pre- and post-feedback task, respectively. Balance performance measures were also collected. Following the feedback, participants in the good group were more likely to choose the most challenging task while those in the poor group were more likely to choose the least challenging task. Following the feedback, all groups showed improved balance performance. However, balance efficacy and perceived stability increased for the good and control groups but balance efficacy decreased and perceived stability was unchanged for the poor group. Thus, these findings demonstrate that verbal persuasion can influence task choice and may be used as an approach to experimentally create mismatches between perceived and actual balance. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. 78 FR 49595 - Aviation Rulemaking Advisory Committee-New Task

    Science.gov (United States)

    2013-08-14

    ... Maintenance Reliability Program Working Group. FOR FURTHER INFORMATION CONTACT: Paul K. Pitts, Federal... assigned and ARAC has accepted this task and will establish the Maintenance Reliability Program Working... maintenance in reliability program control mechanisms recognized by the FAA. Specifically, it requested the...