Quantifying Appropriate PTV Setup Margins: Analysis of Patient Setup Fidelity and Intrafraction Motion Using Post-Treatment Megavoltage Computed Tomography Scans

International Nuclear Information System (INIS)

Drabik, Donata M.; MacKenzie, Marc A.; Fallone, Gino B.

2007-01-01

Purpose: To present a technique that can be implemented in-house to evaluate the efficacy of immobilization and image-guided setup of patients with different treatment sites on helical tomotherapy. This technique uses an analysis of alignment shifts between kilovoltage computed tomography and post-treatment megavoltage computed tomography images. The determination of the shifts calculated by the helical tomotherapy software for a given site can then be used to define appropriate planning target volume internal margins. Methods and Materials: Twelve patients underwent post-treatment megavoltage computed tomography scans on a helical tomotherapy machine to assess patient setup fidelity and net intrafraction motion. Shifts were studied for the prostate, head and neck, and glioblastoma multiforme. Analysis of these data was performed using automatic and manual registration of the kilovoltage computed tomography and post-megavoltage computed tomography images. Results: The shifts were largest for the prostate, followed by the head and neck, with glioblastoma multiforme having the smallest shifts in general. It appears that it might be more appropriate to use asymmetric planning target volume margins. Each margin value reported is equal to two standard deviations of the average shift in the given direction. Conclusion: This method could be applied using individual patient post-image scanning and combined with adaptive planning to reduce or increase the margins as appropriate

Correspondence between conventional and digitised radiographs for assessment of marginal bone.

Science.gov (United States)

Bahrami, Golnosh; Isidor, Flemming; Wenzel, Ann; Vaeth, Michael

2013-01-01

To compare reproducibility of marginal bone measurements in conventional film and digitised radiographs and to assess whether variations in reproducibility occurred in measurements taken in a longitudinal, epidemiological survey. Triplicate measurements of the marginal bone level and of remaining bone were obtained from film and digitised full-mouth radiographic surveys from 20 individuals who were examined three times at five-year intervals in a longitudinal study design. The digitalisation of the films was conducted by scanning the film with a flatbed scanner. The standard deviation (SD) of the triplicate measurements served as the statistic for reproducibility. The time spent for recording one radiographic survey, which consisted of 14 periapicals and 2 bitewings, was documented. Statistically significant differences existed in the reproducibility of marginal bone level measurements obtained at the first examination and the two subsequent examinations both for film and digitised radiographs (P < 0.05). The difference in marginal bone level measurements (film vs digitised) was 0.16 mm (SD = 0.45 mm). Similarly, the overall difference in measurements of the remaining bone was 0.12 mm (SD = 0.61 mm). Recording of a digitised survey lasted on average 5 min (SD = 1.5 min), while the recording of a film survey lasted on average 14 min (SD = 1 min). Digitising film is an acceptable method for the purpose of assessing the marginal bone level and will save time in longitudinal, epidemiological studies.

Value chain and marketing margins of cassava: An assessment of ...

African Journals Online (AJOL)

Value chain and marketing margins of cassava: An assessment of cassava marketing in ... African Journal of Food, Agriculture, Nutrition and Development ... Cassava is one of the emerging market oriented agricultural commodities with ...

Assessment of tsunami hazard to the U.S. Atlantic margin

Science.gov (United States)

ten Brink, Uri S.; Chaytor, Jason; Geist, Eric L.; Brothers, Daniel S.; Andrews, Brian D.

2014-01-01

Tsunami hazard is a very low-probability, but potentially high-risk natural hazard, posing unique challenges to scientists and policy makers trying to mitigate its impacts. These challenges are illustrated in this assessment of tsunami hazard to the U.S. Atlantic margin. Seismic activity along the U.S. Atlantic margin in general is low, and confirmed paleo-tsunami deposits have not yet been found, suggesting a very low rate of hazard. However, the devastating 1929 Grand Banks tsunami along the Atlantic margin of Canada shows that these events continue to occur. Densely populated areas, extensive industrial and port facilities, and the presence of ten nuclear power plants along the coast, make this region highly vulnerable to flooding by tsunamis and therefore even low-probability events need to be evaluated.

Energy system analyses of the marginal energy technology in life cycle assessments

DEFF Research Database (Denmark)

Mathiesen, B.V.; Münster, Marie; Fruergaard, Thilde

2007-01-01

in historical and potential future energy systems. Subsequently, key LCA studies of products and different waste flows are analysed in relation to the recom- mendations in consequential LCA. Finally, a case of increased waste used for incineration is examined using an energy system analysis model......In life cycle assessments consequential LCA is used as the “state-of-the-art” methodology, which focuses on the consequences of decisions made in terms of system boundaries, allocation and selection of data, simple and dynamic marginal technology, etc.(Ekvall & Weidema 2004). In many LCA studies...... marginal technology? How is the marginal technology identified and used today? What is the consequence of not using energy system analy- sis for identifying the marginal energy technologies? The use of the methodology is examined from three angles. First, the marginal electricity technology is identified...

Developing tools to identify marginal lands and assess their potential for bioenergy production

Science.gov (United States)

Galatsidas, Spyridon; Gounaris, Nikolaos; Dimitriadis, Elias; Rettenmaier, Nils; Schmidt, Tobias; Vlachaki, Despoina

2017-04-01

The term "marginal land" is currently intertwined in discussions about bioenergy although its definition is neither specific nor firm. The uncertainty arising from marginal land classification and quantification is one of the major constraining factors for its potential use. The clarification of political aims, i.e. "what should be supported?" is also an important constraining factor. Many approaches have been developed to identify marginal lands, based on various definitions according to the management goals. Concerns have been frequently raised regarding the impacts of marginal land use on environment, ecosystem services and sustainability. Current tools of soil quality and land potentials assessment fail to meet the needs of marginal land identification and exploitation for biomass production, due to the lack of comprehensive analysis of interrelated land functions and their quantitative evaluation. Land marginality is determined by dynamic characteristics in many cases and may therefore constitute a transitional state, which requires reassessment in due time. Also, marginal land should not be considered simply a dormant natural resource waiting to be used, since it may already provide multiple benefits and services to society relating to wildlife, biodiversity, carbon sequestration, etc. The consequences of cultivating such lands need to be fully addressed to present a balanced view of their sustainable potential for bioenergy. This framework is the basis for the development of the SEEMLA tools, which aim at supporting the identification, assessment, management of marginal lands in Europe and the decision-making for sustainable biomass production of them using appropriate bioenergy crops. The tools comprise two applications, a web-based one (independent of spatial data) and a GIS-based application (land regionalization on the basis of spatial data), which both incorporate: - Land resource characteristics, restricting the cultivation of agricultural crops but

WSEAT Shock Testing Margin Assessment Using Energy Spectra Final Report.

Energy Technology Data Exchange (ETDEWEB)

Sisemore, Carl; Babuska, Vit; Booher, Jason

2018-02-01

Several programs at Sandia National Laboratories have adopted energy spectra as a metric to relate the severity of mechanical insults to structural capacity. The purpose being to gain insight into the system's capability, reliability, and to quantify the ultimate margin between the normal operating envelope and the likely system failure point -- a system margin assessment. The fundamental concern with the use of energy metrics was that the applicability domain and implementation details were not completely defined for many problems of interest. The goal of this WSEAT project was to examine that domain of applicability and work out the necessary implementation details. The goal of this project was to provide experimental validation for the energy spectra based methods in the context of margin assessment as they relate to shock environments. The extensive test results concluded that failure predictions using energy methods did not agree with failure predictions using S-N data. As a result, a modification to the energy methods was developed following the form of Basquin's equation to incorporate the power law exponent for fatigue damage. This update to the energy-based framework brings the energy based metrics into agreement with experimental data and historical S-N data.

Quantification of the variability of diaphragm motion and implications for treatment margin construction

NARCIS (Netherlands)

Rit, Simon; van Herk, Marcel; Zijp, Lambert; Sonke, Jan-Jakob

2012-01-01

To quantify the variability of diaphragm motion during free-breathing radiotherapy of lung patients and its effect on treatment margins to account for geometric uncertainties. Thirty-three lung cancer patients were analyzed. Each patient had 5-19 cone-beam scans acquired during different treatment

On-line fatigue monitoring and margins probabilistic assessment

International Nuclear Information System (INIS)

Fournier, I.; Morilhat, P.

1993-01-01

An on-line computer aided system has been developed by Electricite de France, the French utility, for a fatigue monitoring of critical locations in the nuclear steam supply system. This tool, called fatiguemeter, includes as input data only existing plant parameters and is based on some conservative assumptions at several steps of the damage assessment (thermal boundary conditions, stress computation...). This paper presents recent developments performed toward a better assessing of margins involved in the complete analysis. The methodology is enlightened with an example showing the influence of plant parameters incertitude on the final stress computed at a PWR 900 MW unit pressurizer surge line nozzle. (author)

Market modeling for assessment of demand side programs using the marginal cost

International Nuclear Information System (INIS)

Papastamatiou, Panagiotis; Psarras, John

2000-01-01

Demand side management is nowadays considered as a functional step in the energy planning process. The criteria proposed for the assessment of the demand side programs (DSPs) are usually based on the balance between the marginal supply cost and the mean DSP cost. These criteria could not support the allotting of the invested capital to incentives for the consumers and advertising. This paper presents a methodology to support the utility planning at this point with more reliability. It proposes the expansion of the assessment criteria with the use of the marginal cost of the DSP. For the calculation of the DSP marginal cost, a dynamic model is developed and it is used for the simulation of the penetration of a DS Program. Using the 'least-cost' criterion as the decision rule for the simulation, the planner has a distribution of the available investment capital throughout the whole planning period. The use of the 'most-value' criterion supports the separation of the invested capital between incentives for the consumers and supportive expenses, e.g. advertising, marketing cost, etc. (Author)

Fracture mechanics characteristics and associated safety margins for integrity assessment; Bruchmechanische Kennwerte und zugeordnete Sicherheitsfaktoren bei Integritaetsanalysen

Energy Technology Data Exchange (ETDEWEB)

Roos, E.; Schuler, X.; Stumpfrock, L.; Silcher, H. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA)

2008-07-01

Within the integrity assessment of components and structural members of plants safety margins have to be applied, whose magnitude depend on several factors. Important factors influencing the magnitude of the safety margins are as for instance: Material behaviour (ductile / brittle behaviour), the event to be considered (local deformation / fracture), possible consequences of failure (human health, environmental damage, economic consequences) and many others. One important factor also is the fact, how precisely and reliably the appropriate material characteristics can be determined and how precisely and reliably the components behaviour can be predicted and assessed by means of this material characteristic. In contemporary safety assessment procedures by means of fracture mechanics evaluation tools (e.g. [1]) a concept of partial safety margins is proposed for application. The basic idea with this procedure is that only those sources of uncertainty have to be considered, which are relevant or may be relevant for the structure to be considered. For this purpose each source of possible uncertainty has to be quantified individually, finally only those singular safety margins are superimposed to a total safety margin which are relevant. The more the uncertainties have to be taken into account, the total safety margin to be applied, consequently will be larger. If some sources of uncertainty can be eliminated totally or can be minimized (for instance by a more reliable calculational procedure of the component loading or by more precise material characteristics), the total safety margin can be reduced. In this contribution the different procedures for the definition of safety margins within the integrity assessment by means of fracture mechanics procedures will be discussed. (orig.)

Towards intraoperative assessment of tumor margins in breast surgery using optical coherence elastography (Conference Presentation)

Science.gov (United States)

Kennedy, Brendan F.; Wijesinghe, Philip; Allen, Wes M.; Chin, Lixin; Latham, Bruce; Saunders, Christobel M.; Sampson, David D.

2016-03-01

Surgical excision of tumor is a critical factor in the management of breast cancer. The most common surgical procedure is breast-conserving surgery. The surgeon's goal is to remove the tumor and a rim of healthy tissue surrounding the tumor: the surgical margin. A major issue in breast-conserving surgery is the absence of a reliable tool to guide the surgeon in intraoperatively assessing the margin. A number of techniques have been proposed; however, the re-excision rate remains high and has been reported to be in the range 30-60%. New tools are needed to address this issue. Optical coherence elastography (OCE) shows promise as a tool for intraoperative tumor margin assessment in breast-conserving surgery. Further advances towards clinical translation are limited by long scan times and small fields of view. In particular, scanning over sufficient areas to assess the entire margin in an intraoperative timeframe has not been shown to be feasible. Here, we present a protocol allowing ~75% of the surgical margins to be assessed within 30 minutes. To achieve this, we have incorporated a 65 mm-diameter (internal), wide-aperture annular piezoelectric transducer, allowing the entire surface of the excised tumor mass to be automatically imaged in an OCT mosaic comprised of 10 × 10 mm tiles. As OCT is effective in identifying adipose tissue, our protocol uses the wide-field OCT to selectively guide subsequent local OCE scanning to regions of solid tissue which often present low contrast in OCT images. We present promising examples from freshly excised human breast tissue.

Oral antioxidant therapy for marginal dry eye.

Science.gov (United States)

Blades, K J; Patel, S; Aidoo, K E

2001-07-01

To assess the efficacy of an orally administered antioxidant dietary supplement for managing marginal dry eye. A prospective, randomised, placebo controlled trial with cross-over. Eye Clinic, Department of Vision Sciences, Glasgow Caledonian University. Forty marginal dry eye sufferers composed of 30 females and 10 males (median age 53 y; range 38-69 y). Baseline assessments were made of tear volume sufficiency (thread test), tear quality (stability), ocular surface status (conjunctival impression cytology) and dry eye symptoms (questionnaire). Each subject was administered courses of active treatment, placebo and no treatment, in random order for 1 month each and results compared to baseline. Tear stability and ocular surface status were significantly improved following active treatment (Ptreatment (P>0.05). Absolute increase in tear stability correlated with absolute change in goblet cell population density. Tear volume was not improved following any treatment period and dry eye symptom responses were subject to placebo effect. Oral antioxidants improved both tear stability and conjunctival health, although it is not yet understood whether increased ocular surface health mediates increased tear stability or vice versa. This study was supported by a PhD scholarship funded by the Department of Vision Sciences, Glasgow Caledonian University, Scotland. Antioxidant supplements and placebos were kindly donated by Vitabiotics.

The value of breast lumpectomy margin assessment as a predictor of residual tumor burden

International Nuclear Information System (INIS)

Wazer, David E.; Schmidt-Ullrich, Rupert K.; Schmid, Christopher H.; Ruthazer, Robin; Kramer, Bradley; Safaii, Homa; Graham, Roger

1997-01-01

Purpose: Margin assessment is commonly used as a guide to the relative aggressiveness of therapy for breast conserving treatment (BCT), though its value as a predictor of the presence, type, or extent of residual tumor has not been conclusively studied. Controversy continues to exist as to what constitutes a margin that is 'positive', 'close', or 'negative'. We attempt to address these issues through an analysis of re-excision specimens. Patients and Methods: As part of an institutional prospective practice approach for BCT, 265 cases with AJCC Stage I/II carcinoma with an initial excision margin that was ≤2 mm or indeterminate were subjected to re-excision. The probability of residual tumor (+RE) was evaluated with respect to tumor size, histopathologic subtype, relative closeness of the measured margin, the extent of margin positivity graded as focal, minimal, moderate, or extensive, and the extent of specimen processing as reflected in the number of cut sections per specimen volume (S:V ratio). The amount of residual tumor was graded as microscopic, small, medium, or large. The histopathologic subtype of tumor in the re-excision specimen was classified as having an invasive component (ICa) or pure DCIS (DCIS). Results: The primary excision margin was positive, >0≤1 mm, 1.1-2 mm, and indeterminate in 60%, 18%, 5%, and 17%, respectively. The predominant histopathologies in the initial excision specimens were invasive ductal (IDC) (50%) and tumors with an extensive intraductal component (EIC) (43%). The histopathology of the initial excision specimen was highly predictive of the histopathology of tumor found on re-excision, as residual DCIS was found in 60% of +RE specimens with initial histopathology of EIC compared to 26% for IDC (p 0.001). Neither the extent of margin positivity nor the extent of tumor in the re-excision were significantly related to the initial histopathologic subtype; however, a +RE was seen in 59% of EIC, 43% of IDC, and 32% of invasive

Comparison of seismic margin assessment and probabilistic risk assessment in seismic IPE

International Nuclear Information System (INIS)

Reed, J.W.; Kassawara, R.P.

1993-01-01

A comparison of technical requirements and managerial issues between seismic margin assessment (SMA) and seismic probabilistic risk assessment (SPRA) in a seismic Individual Plant Examination (IPE) is presented and related to requirements for an Unresolved Safety Issue (USI) A-46 review which is required for older nuclear power plants. Advantages and disadvantages are discussed for each approach. Technical requirements reviewed for a seismic IPE include: scope of plants covered, seismic input, scope of review, selection of equipment, required experience and training of engineers, walkdown procedure, evaluation of components, relay review, containment review, quality assurance, products, documentation requirements, and closure procedure. Managerial issues discussed include regulatory acceptability, compatibility with seismic IPE, compliance with seismic IPE requirements, ease of use by utilities, and relative cost

Seismic safety margin assessment program (Annual safety research report, JFY 2010)

International Nuclear Information System (INIS)

Suzuki, Kenichi; Iijima, Toru; Inagaki, Masakatsu; Taoka, Hideto; Hidaka, Shinjiro

2011-01-01

Seismic capacity test data, analysis method and evaluation code provided by Seismic Safety Margin Assessment Program have been utilized for the support of seismic back-check evaluation of existing plants. The summary of the program in 2010 is as follows. 1. Component seismic capacity test and quantitative seismic capacity evaluation. Many seismic capacity tests of various snubbers were conducted and quantitative seismic capacities were evaluated. One of the emergency diesel generator partial-model seismic capacity tests was conducted and quantitative seismic capacity was evaluated. Some of the analytical evaluations of piping-system seismic capacities were conducted. 2. Analysis method for minute evaluation of component seismic response. The difference of seismic response of large components such as primary containment vessel and reactor pressure vessel when they were coupled with 3-dimensional FEM building model or 1-dimensional lumped mass building model, was quantitatively evaluated. 3. Evaluation code for quantitative evaluation of seismic safety margin of systems, structures and components. As the example, quantitative evaluation of seismic safety margin of systems, structures and components were conducted for the reference plant. (author)

On-line fatigue monitoring and probabilistic assessment of margins

Energy Technology Data Exchange (ETDEWEB)

Fournier, I. [Electricite de France, 93 - Saint-Denis (France). Direction des Etudes et Recherches; Morilhat, P. [Electricite de France, 93 - Saint-Denis (France). Direction des Etudes et Recherches

1995-01-01

An on-line computer-aided system has been developed by Electricite de France, the French utility, for fatigue monitoring of critical locations in the nuclear steam supply system. This tool, called a fatigue meter, includes as input data plant parameters and is based on some conservative assumptions at several steps of the damage assessment (thermal boundary conditions, stress computation,..). In this paper we present recent developments performed towards a better assessment of margins involved in the complete analysis. The methodology is illustrated with an example showing the influence of uncertainty in plant parameters on the final stress computed at a pressurized water reactor 900MW unit pressurizer surge line nozzle. A second example is shown to illustrate the possibility of defining some transient archetypes. ((orig.)).

An assessment of seismic margins in nuclear plant piping

International Nuclear Information System (INIS)

Chen, W.P.; Jaquay, K.R.; Chokshi, N.C.; Terao, D.

1995-01-01

Interim results of an ongoing program to assist the U.S. Nuclear Regulatory Commission (NRC) in developing regulatory positions on the seismic analyses of piping and overall safety margins of piping systems are reported. Results of reviews of previous seismic testing, primarily the Electric Power Research Institute (EPRI)/NRC Piping and Fitting Dynamic Reliability Program, and assessments of the ASME Code, Section III, piping seismic design criteria as revised by the 1994 Addenda are reported. Major issues are identified herein only. Technical details are to be provided elsewhere. (author). 4 refs., 2 figs

A Pareto analysis approach to assess relevant marginal CO{sub 2} footprint for petroleum products

Energy Technology Data Exchange (ETDEWEB)

Tehrani, Nejad M. Alireza, E-mail: alireza.tehraninejad@gmail.com

2015-07-15

Recently, linear programing (LP) models have been extended to track the marginal CO{sub 2} intensity of automotive fuels at the refinery gate. The obtained CO{sub 2} data are recommended for policy making because they capture the economic and environmental tensions as well as the processing effects related to oil products. However, they are proven to be extremely sensitive to small perturbations and therefore useless in practice. In this paper, we first investigate the theoretical reasons of this drawback. Then, we develop a multiple objective LP framework to assess relevant marginal CO{sub 2} footprints that preserve both defensibility and stability at a satisfactory level of acceptance. A case study illustrates this new methodology. - Highlights: • Refining LP models have limitations to provide useful marginal CO{sub 2} footprints. • A multi objective optimization framework is developed to assess relevant CO{sub 2} data. • Within a European Refinig industry, diesel is more CO{sub 2} intensive than gasoline.

Use of response envelopes for seismic margin assessment of reinforced concrete walls and slabs

Energy Technology Data Exchange (ETDEWEB)

Ile, Nicolas; Frau, Alberto, E-mail: alberto.frau@cea.fr

2017-04-01

Highlights: • Proposal of a method for application of the elliptical envelope to RC shell elements. • Proposal of new algorithms for the seismic margin evaluation for RC shell elements. • Verification of a RC wall 3D structure, using the proposed assessment approach. - Abstract: Seismic safety evaluations of existing nuclear facilities are usually based on the assumption of structural linearity. For the design basis earthquake (DBE), it is reasonable to apply a conventional evaluation of the seismic safety of building structures and carry out a linear elastic analysis to assess the load effects on structural elements. Estimating the seismic capacity of a structural element requires an estimation of the critical combination of responses acting in this structural element and compare this combination with the capacity of the element. By exploiting the response-spectrum-based procedure for predicting the response envelopes in linear structures formulated by Menun and Der Kiureghian (2000a), algorithms are developed for the seismic margin assessment of reinforced concrete shell finite elements. These algorithms facilitate the comparison of the response-spectrum-based envelopes to prescribed capacity surfaces for the purpose of assessing the safety margin of this kind of structures. The practical application of elliptical response envelopes in case of shell finite elements is based on the use of layer models such as those developed by Marti (1990), which transfer the generalized stress field to three layers under the assumption that the two outer layers carry membrane forces and the internal layer carries only the out-of-plane shears. The utility of the assessment approach is discussed with reference to a case study of a 3D structure made of reinforced concrete walls.

Use of response envelopes for seismic margin assessment of reinforced concrete walls and slabs

International Nuclear Information System (INIS)

Ile, Nicolas; Frau, Alberto

2017-01-01

Highlights: • Proposal of a method for application of the elliptical envelope to RC shell elements. • Proposal of new algorithms for the seismic margin evaluation for RC shell elements. • Verification of a RC wall 3D structure, using the proposed assessment approach. - Abstract: Seismic safety evaluations of existing nuclear facilities are usually based on the assumption of structural linearity. For the design basis earthquake (DBE), it is reasonable to apply a conventional evaluation of the seismic safety of building structures and carry out a linear elastic analysis to assess the load effects on structural elements. Estimating the seismic capacity of a structural element requires an estimation of the critical combination of responses acting in this structural element and compare this combination with the capacity of the element. By exploiting the response-spectrum-based procedure for predicting the response envelopes in linear structures formulated by Menun and Der Kiureghian (2000a), algorithms are developed for the seismic margin assessment of reinforced concrete shell finite elements. These algorithms facilitate the comparison of the response-spectrum-based envelopes to prescribed capacity surfaces for the purpose of assessing the safety margin of this kind of structures. The practical application of elliptical response envelopes in case of shell finite elements is based on the use of layer models such as those developed by Marti (1990), which transfer the generalized stress field to three layers under the assumption that the two outer layers carry membrane forces and the internal layer carries only the out-of-plane shears. The utility of the assessment approach is discussed with reference to a case study of a 3D structure made of reinforced concrete walls.

Indigenous women's voices: marginalization and health.

Science.gov (United States)

Dodgson, Joan E; Struthers, Roxanne

2005-10-01

Marginalization may affect health care delivery. Ways in which indigenous women experienced marginalization were examined. Data from 57 indigenous women (18 to 65 years) were analyzed for themes. Three themes emerged: historical trauma as lived marginalization, biculturalism experienced as marginalization, and interacting within a complex health care system. Experienced marginalization reflected participants' unique perspective and were congruent with previous research. It is necessary for health care providers to assess the detrimental impact of marginalization on the health status of individuals and/or communities.

Setup uncertainties in linear accelerator based stereotactic radiosurgery and a derivation of the corresponding setup margin for treatment planning.

Science.gov (United States)

Zhang, Mutian; Zhang, Qinghui; Gan, Hua; Li, Sicong; Zhou, Su-min

2016-02-01

In the present study, clinical stereotactic radiosurgery (SRS) setup uncertainties from image-guidance data are analyzed, and the corresponding setup margin is estimated for treatment planning purposes. Patients undergoing single-fraction SRS at our institution were localized using invasive head ring or non-invasive thermoplastic masks. Setup discrepancies were obtained from an in-room x-ray patient position monitoring system. Post treatment re-planning using the measured setup errors was performed in order to estimate the individual target margins sufficient to compensate for the actual setup errors. The formula of setup margin for a general SRS patient population was derived by proposing a correlation between the three-dimensional setup error and the required minimal margin. Setup errors of 104 brain lesions were analyzed, in which 81 lesions were treated using an invasive head ring, and 23 were treated using non-invasive masks. In the mask cases with image guidance, the translational setup uncertainties achieved the same level as those in the head ring cases. Re-planning results showed that the margins for individual patients could be smaller than the clinical three-dimensional setup errors. The derivation of setup margin adequate to address the patient setup errors was demonstrated by using the arbitrary planning goal of treating 95% of the lesions with sufficient doses. With image guidance, the patient setup accuracy of mask cases can be comparable to that of invasive head rings. The SRS setup margin can be derived for a patient population with the proposed margin formula to compensate for the institution-specific setup errors. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Safety Margin Assessment (SM2A): Stimulation for Further Development of BEPU Approaches?

International Nuclear Information System (INIS)

Zimmermann, Martin A.

2013-01-01

During recent years, many nuclear power plants underwent significant modifications, e.g. power up-rating. While compliance with all the deterministic acceptance criteria must be shown during the licensing process, the larger core inventory and the facts that the plant response might get closer to the limits after a power up-rate, suggest an increase of the core damage frequency (CDF) and other possible risk indicators. Hence, a framework to quantitatively assess a change in plant safety margin becomes very desirable. The Committee on the Safety of Nuclear Installations (CSNI) mandated the Safety Margin Action Plan expert group (SMAP) to develop a framework for the assessment of such changes to safety margin. This framework combines PSA and the analytical techniques developed in BEPU. CSNI then mandated the SM2A expert group to especially explore the practicability of the SMAP framework. This pilot study was completed end of 2010. An increase of the (conditional) probability of exceedance for a surrogate acceptance limit (PCT) indicating core damage was successfully evaluated for the selected sequences from several initiating event trees, and it was found that only a restricted number of sequences need to be analyzed. Based on the insights gained from this study, areas of methodology improvement have been identified and related proposals for further R and D work will be discussed. (authors)

Methodology for the Assessment of Confidence in Safety Margin for Small Break Loss of Coolant Accident Sequences

Energy Technology Data Exchange (ETDEWEB)

Nagrale, D. B.; Prasad, M.; Rao, R. S.; Gaikwad, A.J., E-mail: avinashg@aerb.gov.in [Nuclear Safety Analysis Division, Atomic Energy Regulatory Board, Mumbai (India)

2014-10-15

Deterministic Safety Analysis and Probabilistic Safety Assessment (PSA) analyses are used concurrently to assess the Nuclear Power Plant (NPP) safety. The conventional deterministic analysis is conservative. The best estimate plus uncertainty analysis is increasingly being used for deterministic calculation in NPPs. The PSA methodology aims to be as realistic as possible while integrating information about accident phenomena, plant design, operating practices, component reliability and human behaviour. The peak clad temperature (PCT) distribution provides an insight into the confidence in safety margin for an initiating event. The paper deals with the concept of calculating the peak clad temperature with 95 percent confidence and 95 percent probability (PCT{sub 95/95}) in small break loss of coolant accident (SBLOCA) and methodologies for assessing safety margin. Five input parameters mainly, nominal power level, decay power, fuel clad gap conductivity, fuel thermal conductivity and discharge coefficient, were selected. A Uniform probability density function was assigned to the uncertain parameters and these uncertainties are propagated using Latin Hypercube Sampling (LHS) technique. The sampled data for 5 parameters were randomly mixed by LHS to obtain 25 input sets. A non-core damage accident sequence was selected from the SBLOCA event tree of a typical VVER study to estimate the PCTs and safety margin. A Kolmogorov– Smirnov goodness-of-fit test was carried out for PCTs. The smallest value of safety margin would indicate the robustness of the system with 95% confidence and 95% probability. Regression analysis was also carried out using 1000 sample size for the estimating PCTs. Mean, variance and finally safety margin were analysed. (author)

Outcome of wide local excision in dermatofibrosarcoma protuberans and use of radiotherapy for margin-positive disease

Directory of Open Access Journals (Sweden)

Raashid Hamid

2013-01-01

Full Text Available Purpose: Wide local excision (WLE is the preferred treatment of dermatofibrosarcoma protuberans (DFSP. The aim is to achieve negtive margins. We followed the impact of radiotherapy used postoperatively for both margin-negative and margin-positive DFSP tumors. Materials and Methods: Outcome of treatment of 36 patients of DFSP treated at our hospital was assessed. Thirty patients received radiotherapy postoperatively and six patients received radiotherapy alone. The maximum dimension of the lesion was 15 cm 2 . Patients were followed up for varying periods of time for any recurrence. Results: 10-year actuarial local control rate was determined. Local control was realized in six patients who were treated with radiotherapy alone. 30 patients were treated by radiotherapy and surgery. Out of these 30 patients, there were 6 local failures (failure rate 10%. Actuarial control rate was 82%. The failures were among patients who had positive margins. Conclusion: Radiotherapy is effective, and it decreases the recurrence rate in the treatment of DFSP. It is especially helpful in margin-positive disease. This appears true for patients treated with radiotherapy alone or radiotherapy used postoperatively.

Assessing Mediation Using Marginal Structural Models in the Presence of Confounding and Moderation

Science.gov (United States)

Coffman, Donna L.; Zhong, Wei

2012-01-01

This article presents marginal structural models with inverse propensity weighting (IPW) for assessing mediation. Generally, individuals are not randomly assigned to levels of the mediator. Therefore, confounders of the mediator and outcome may exist that limit causal inferences, a goal of mediation analysis. Either regression adjustment or IPW…

Complete removal of a breast mass by US-guided mammotome biopsy: histologic assessment by marginal sampling

International Nuclear Information System (INIS)

Kim, Youn Jeong; Choi, Hye Young; Moon, Byung In; Lee, Shi Nae

2005-01-01

The aim of this study was to assess whether the complete removal of a breast mass using ultrasound (US) guided mammotome biopsy was successful using a marginal biopsy after insuring the total visual excision of the breast mass on US images. The relationship of complete breast mass removal, and the hematoma, mass size and shape were also evaluated. A US guided mammotome biopsy was performed in a total of 136 cases in 133 patients, with marginal biopsies also added when the complete removal of breast mass had been identified by sonography. The results of the marginal biopsies were serially dividing into three groups, as follows: group I were the cases in the initial 6 months, group II after the initial 6 months and group III having undergone two marginal biopsies. The marginal biopsies were performed in four directions around the probe, with 'marginal positivity' defined as the same histopathological findings to that of the main mass in at least one direction. A statistical analysis was also used to evaluate between the marginal positivity and the hematoma, mass size and shape. The marginal positivities of groups I, II and III were 48.8, 29.4 and 45.5%, respectively. The marginal positivity of those with a lobular shaped mass was significantly higher (ρ = 0.0121) than those with round or oval shaped masses (61.5 vs 33.7 vs 50%), but showed no statistical relationship with hematoma size of the lesions. Although the lesions were removed by US using a US-guided mammotome biopsy, many residual lesions were still histologically present in the marginal samplings, especially in the lobular shaped masse

Efficacy of intra-meibomian gland injection of the anti-VEGF agent bevacizumab for the treatment of meibomian gland dysfunction with lid-margin vascularity

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Jiang X

2018-05-01

Full Text Available Xiaodan Jiang,* Yuexin Wang,* Huibin Lv, Yan Liu, Mingzhou Zhang, Xuemin Li Department of Ophthalmology, Peking University Third Hospital, Beijing, China *These authors contributed equally to this work Purpose: To investigate the efficacy of a novel treatment – intra-meibomian gland (MG injection of the anti-VEGF agent bevacizumab – for MG dysfunction (MGD with eyelid-margin vascularity. Methods: A total of 26 eyes from 13 patients diagnosed with MGD and eyelid-margin vascularity were included in our study. Patients received intra-meibomian gland injections of bevacizumab (150 µL, 2.5 mg/0.1 mL at multiple sites with a 29 G needle where telangiectasia was severe. The Ocular Surface Disease Index (OSDI, tear film, tear-breakup time (TBUT, eyelid-margin features, MG features, conjunctiva, and corneal staining were assessed at 1 day before injection and 1 week, 1 month, and 3 months after injection. Blood pressure, best-corrected visual acuity, intraocular pressure, and slit lamp examinations were performed to assure the safety of patients at 1 day before and 1 day, 1 week, 1 month, and 3 months after injection. Results: Lid-margin vascularity, conjunctival injection, expressed secretion quality, expressivity of the MG, TBUT, corneal staining, and OSDI were significantly improved 1 week, 1 month, and 3 months after injection compared to baseline values. Lid-margin vascularity, conjunctival injection, meibomian gland expressivity, TBUT, and OSDI continued to improve; the greatest improvements were observed at 1 month and sustained for 3 months. Spearman’s correlation analysis indicated that age and sex significantly influenced TBUT improvement. Females and older patients tended to have shorter baseline TBUT that followed a different trend from that of males and younger patients during postinjection visits, revealed by subgroup analysis. No local or systemic side effects were observed at follow-up visits. Conclusion: This study is the first to

Experimental validation of the van Herk margin formula for lung radiation therapy

International Nuclear Information System (INIS)

Ecclestone, Gillian; Heath, Emily; Bissonnette, Jean-Pierre

2013-01-01

Purpose: To validate the van Herk margin formula for lung radiation therapy using realistic dose calculation algorithms and respiratory motion modeling. The robustness of the margin formula against variations in lesion size, peak-to-peak motion amplitude, tissue density, treatment technique, and plan conformity was assessed, along with the margin formula assumption of a homogeneous dose distribution with perfect plan conformity.Methods: 3DCRT and IMRT lung treatment plans were generated within the ORBIT treatment planning platform (RaySearch Laboratories, Sweden) on 4DCT datasets of virtual phantoms. Random and systematic respiratory motion induced errors were simulated using deformable registration and dose accumulation tools available within ORBIT for simulated cases of varying lesion sizes, peak-to-peak motion amplitudes, tissue densities, and plan conformities. A detailed comparison between the margin formula dose profile model, the planned dose profiles, and penumbra widths was also conducted to test the assumptions of the margin formula. Finally, a correction to account for imperfect plan conformity was tested as well as a novel application of the margin formula that accounts for the patient-specific motion trajectory.Results: The van Herk margin formula ensured full clinical target volume coverage for all 3DCRT and IMRT plans of all conformities with the exception of small lesions in soft tissue. No dosimetric trends with respect to plan technique or lesion size were observed for the systematic and random error simulations. However, accumulated plans showed that plan conformity decreased with increasing tumor motion amplitude. When comparing dose profiles assumed in the margin formula model to the treatment plans, discrepancies in the low dose regions were observed for the random and systematic error simulations. However, the margin formula respected, in all experiments, the 95% dose coverage required for planning target volume (PTV) margin derivation, as

Seismic margin assessment of spanish nuclear power plants: a perspective from industry and regulators

International Nuclear Information System (INIS)

Garcia-Monge, Juan; Beltran, Francisco; Sanchez-Cabanero, Jose G.

2001-01-01

The worldwide experience with probabilistic safety analysis (PSA) of nuclear power plants shows that the risk derived from earthquakes can be a significant contributor to core damage frequency in some instances. As a consequence, no severe accident safety assessment can be considered complete without giving, due consideration to seismic risk. This fact has been recognized by some regulators. in particular, by the U.S. Nuclear Regulatory Commission (NRC), who has included seismic risk assessment in its severe accident policy. The NRC severe accident policy was adopted by the Spanish nuclear regulator. the Consejo de Seguridad Nuclear (CSN). As a result. all plants in Spain were asked to perform a seismic risk analysis according to Supplements No. 4 and 5 of Generic Letter 88-20 and NUREG-1407, which included the containment failure analysis. At present in Spain there arc nine operating reactors at seven sites: six Westinghouse-PWR, two GE-BWR and one Siemens/KW U-PWR. The vintages are very different: the oldest plant started commercial operation in 1968 and the most recent, in 1988. In this framework, the Spanish Owners Group (SOG) proposed to CSN in 1994 to carry out the seismic risk analysis of the plants using seismic margin methodologies. This kind of methods requires, as a starting point, the definition of a seismic margin earthquake (SNIE), also called review level earthquake (RLL). For this purpose, tile SOG sponsored a general Probabilistic Seismic Hazard Analysis (PSHA) for the seven Spanish sites. The results of this PSHA were used by the SOG to define tile RLE and the scope of the study for each plant (binning of plants). The proposal was submitted to the CSN for evaluation. The CSN evaluation was based on the NRC practical experience and was helped by the technical advise of US Lawrence Livermore National Laboratory. The review showed that the uncertainties on seismic hazard had not been fully captured and that it would have been justified to consider a

A new assessment method for demonstrating the sufficiency of the safety assessment and the safety margins of the geological disposal system

International Nuclear Information System (INIS)

Ohi, Takao; Kawasaki, Daisuke; Chiba, Tamotsu; Takase, Toshio; Hane, Koji

2013-01-01

A new method for demonstrating the sufficiency of the safety assessment and safety margins of the geological disposal system has been developed. The method is based on an existing comprehensive sensitivity analysis method and can systematically identify the successful conditions, under which the dose rate does not exceed specified safety criteria, using analytical solutions for nuclide migration and the results of a statistical analysis. The successful conditions were identified using three major variables. Furthermore, the successful conditions at the level of factors or parameters were obtained using relational equations between the variables and the factors or parameters making up these variables. In this study, the method was applied to the safety assessment of the geological disposal of transuranic waste in Japan. Based on the system response characteristics obtained from analytical solutions and on the successful conditions, the classification of the analytical conditions, the sufficiency of the safety assessment and the safety margins of the disposal system were then demonstrated. A new assessment procedure incorporating this method into the existing safety assessment approach is proposed in this study. Using this procedure, it is possible to conduct a series of safety assessment activities in a logical manner. (author)

Calculating radiotherapy margins based on Bayesian modelling of patient specific random errors

International Nuclear Information System (INIS)

Herschtal, A; Te Marvelde, L; Mengersen, K; Foroudi, F; Ball, D; Devereux, T; Pham, D; Greer, P B; Pichler, P; Eade, T; Kneebone, A; Bell, L; Caine, H; Hindson, B; Kron, T; Hosseinifard, Z

2015-01-01

Collected real-life clinical target volume (CTV) displacement data show that some patients undergoing external beam radiotherapy (EBRT) demonstrate significantly more fraction-to-fraction variability in their displacement (‘random error’) than others. This contrasts with the common assumption made by historical recipes for margin estimation for EBRT, that the random error is constant across patients. In this work we present statistical models of CTV displacements in which random errors are characterised by an inverse gamma (IG) distribution in order to assess the impact of random error variability on CTV-to-PTV margin widths, for eight real world patient cohorts from four institutions, and for different sites of malignancy. We considered a variety of clinical treatment requirements and penumbral widths. The eight cohorts consisted of a total of 874 patients and 27 391 treatment sessions. Compared to a traditional margin recipe that assumes constant random errors across patients, for a typical 4 mm penumbral width, the IG based margin model mandates that in order to satisfy the common clinical requirement that 90% of patients receive at least 95% of prescribed RT dose to the entire CTV, margins be increased by a median of 10% (range over the eight cohorts −19% to +35%). This substantially reduces the proportion of patients for whom margins are too small to satisfy clinical requirements. (paper)

Economic assessment of Operational Energy reduction options in a house using Marginal Benefit and Marginal Cost: A case in Bangi, Malaysia

International Nuclear Information System (INIS)

Wan Rahmah Mohd Zaki; Abdul Hadi Nawawi; Sabarinah Sh Ahmad

2010-01-01

Energy Efficient (EE) appliances such as Compact Fluorescent Light (CFL) bulbs and Renewable Energy (RE), namely solar Photovoltaic (PV) can help to reduce Operational Energy (OE) in a house. In addition, a house should also incorporate Passive Architecture (PA) design strategies which in the hot and humid tropical climate, mean avoiding direct heat gain, encouraging natural cross ventilation and optimising the abundant daylight. Nevertheless, reducing OE must also mean economic gain to households to encourage their participation. Common economic gauges such as Return on Investment, Payback Period, Cost Benefit Analysis, Life Cycle Assessment and Life Cycle Cost are not suitable to validate OE options in households. These economic gauges approach economic assessment as an end-result on the cost side of the product and may result for good intention to be shelved, primarily because EE equipment and RE have high capital cost compared with the alternatives. On the other hand, reducing OE in houses is actually a continual progression from the status quo and there is always a marginal gain in doing so. The challenge is to know how much is the marginal benefit against the marginal cost of investing in EE and RE. In Economics, the ratio of Marginal Cost (MC) and Marginal Benefits (MB) measure additional benefits of every additional costs of investment at a specific level of production and consumption; and Economists suggests that effective gain and loss should be compared to the status quo, i.e., Relative Position (RP). The Economics theories of MC, MB and RP are being adapted to measure the progression of reducing OE. The living/dining area in two types of houses: with and without PA design strategies are simulated to use conventional incandescent light bulbs and CFL as well as solar PV in lieu of the mains electricity supply. The power requirement for artificial lighting in every case is translated into monetary value and the ratio of MB against MC for each case shows

NRC Seismic Design Margins Program Plan

International Nuclear Information System (INIS)

Cummings, G.E.; Johnson, J.J.; Budnitz, R.J.

1985-08-01

Recent studies estimate that seismically induced core melt comes mainly from earthquakes in the peak ground acceleration range from 2 to 4 times the safe shutdown earthquake (SSE) acceleration used in plant design. However, from the licensing perspective of the US Nuclear Regulatory Commission, there is a continuing need for consideration of the inherent quantitative seismic margins because of, among other things, the changing perceptions of the seismic hazard. This paper discusses a Seismic Design Margins Program Plan, developed under the auspices of the US NRC, that provides the technical basis for assessing the significance of design margins in terms of overall plant safety. The Plan will also identify potential weaknesses that might have to be addressed, and will recommend technical methods for assessing margins at existing plants. For the purposes of this program, a general definition of seismic design margin is expressed in terms of how much larger that the design basis earthquake an earthquake must be to compromise plant safety. In this context, margin needs to be determined at the plant, system/function, structure, and component levels. 14 refs., 1 fig

Marginal Generation Technology in the Chinese Power Market towards 2030 Based on Consequential Life Cycle Assessment

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Guangling Zhao

2016-09-01

Full Text Available Electricity consumption is often the hotspot of life cycle assessment (LCA of products, industrial activities, or services. The objective of this paper is to provide a consistent, scientific, region-specific electricity-supply-based inventory of electricity generation technology for national and regional power grids. Marginal electricity generation technology is pivotal in assessing impacts related to additional consumption of electricity. China covers a large geographical area with regional supply grids; these are arguably equally or less integrated. Meanwhile, it is also a country with internal imbalances in regional energy supply and demand. Therefore, we suggest an approach to achieve a geographical subdivision of the Chinese electricity grid, corresponding to the interprovincial regional power grids, namely the North, the Northeast, the East, the Central, the Northwest, and the Southwest China Grids, and the China Southern Power Grid. The approach combines information from the Chinese national plans on for capacity changes in both production and distribution grids, and knowledge of resource availability. The results show that nationally, marginal technology is coal-fired electricity generation, which is the same scenario in the North and Northwest China Grid. In the Northeast, East, and Central China Grid, nuclear power gradually replaces coal-fired electricity and becomes the marginal technology. In the Southwest China Grid and the China Southern Power Grid, the marginal electricity is hydropower towards 2030.

CRBRP structural and thermal margin beyond the design base

International Nuclear Information System (INIS)

Strawbridge, L.E.

1979-01-01

Prudent margins beyond the design base have been included in the design of Clinch River Breeder Reactor Plant to further reduce the risk to the public from highly improbable occurrences. These margins include Structural Margin Beyond the Design Base to address the energetics aspects and Thermal Margin Beyond the Design Base to address the longer term thermal and radiological consequences. The assessments that led to the specification of these margins are described, along with the experimental support for those assessments. 8 refs

Life Cycle Assessment of Bioenergy from Lignocellulosic Crops Cultivated on Marginal Land in Europe

Science.gov (United States)

Rettenmaier, Nils; Schmidt, Tobias; Gärtner, Sven; Reinhardt, Guido

2017-04-01

Population growth and changing diets due to economic development lead to an additional demand for land for food and feed production. Slowly but surely turning into a mass market, also the cultivation of non-food biomass crops for fibre (bio-based products) and fuel (biofuels and bioenergy) is increasingly contributing to the pressure on global agricultural land. As a consequence, the already prevailing competition for land might even intensify over the next decades. Against this background, the possibilities of shifting the cultivation of non-food biomass crops to so-called 'marginal lands' are investigated. The EC-funded project 'Sustainable exploitation of biomass for bioenergy from marginal lands in Europe' (SEEMLA) aims at the establishment of suitable innovative land-use strategies for a sustainable production of bioenergy from lignocellulosic crops on marginal lands while improving general ecosystem services. For a complete understanding of the environmental benefits and drawbacks of the envisioned cultivation of bioenergy crops on marginal land, life cycle assessments (LCA) have proven to be a suitable and valuable tool. Thus, embedded into a comprehensive sustainability assessment, a screening LCA is carried out for the entire life cycles of the bioenergy carriers researched in SEEMLA. Investigated systems, on the one hand, include the specific field trials carried out by the SEEMLA partners in Ukraine, Greece and Germany. On the other hand, generic scenarios are investigated in order to derive reliable general statements on the environmental impacts of bioenergy from marginal lands in Europe. Investigated crops include woody and herbaceous species such as black locust, poplar, pine, willow and Miscanthus. Conversion technologies cover the use in a domestic or a district heating plant, power plant, CHP as well as the production of Fischer-Tropsch diesel (FT diesel) and lignocellulosic ethanol. Environmental impacts are compared to conventional reference

Test characteristics of high-resolution ultrasound in the preoperative assessment of margins of basal cell and squamous cell carcinoma in patients undergoing Mohs micrographic surgery.

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Jambusaria-Pahlajani, Anokhi; Schmults, Chrysalyne D; Miller, Christopher J; Shin, Daniel; Williams, Jennifer; Kurd, Shanu K; Gelfand, Joel M

2009-01-01

Noninvasive techniques to assess subclinical spread of nonmelanoma skin cancer (NMSC) may improve surgical precision. High-resolution ultrasound has shown promise in evaluating the extent of NMSC. To determine the accuracy of high-resolution ultrasound to assess the margins of basal cell (BCC) and squamous cell carcinomas (SCC) before Mohs micrographic surgery (MMS). We enrolled 100 patients with invasive SCC or BCC. Before the first stage of MMS, a Mohs surgeon delineated the intended surgical margin. Subsequently, a trained ultrasound technologist independently evaluated disease extent using the EPISCAN I-200 to evaluate tumor extent beyond this margin. The accuracy of high-resolution ultrasound was subsequently tested by comparison with pathology from frozen sections. The test characteristics of the high-resolution ultrasound were sensitivity=32%, specificity=88%, positive predictive value=47%, and negative predictive value=79%. Subgroup analyses demonstrated better test characteristics for tumors larger than the median (area>1.74 cm(2)). Qualitative analyses showed that high-resolution ultrasound was less likely to identify extension from tumors with subtle areas of extension, such as small foci of dermal invasion from infiltrative SCC and micronodular BCC. High-resolution ultrasound requires additional refinements to improve the preoperative determination of tumor extent before surgical treatment of NMSC.

Correlation of breast tissue histology and optical signatures to improve margin assessment techniques

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Kennedy, Stephanie; Caldwell, Matthew; Bydlon, Torre; Mulvey, Christine; Mueller, Jenna; Wilke, Lee; Barry, William; Ramanujam, Nimmi; Geradts, Joseph

2016-06-01

Optical spectroscopy is sensitive to morphological composition and has potential applications in intraoperative margin assessment. Here, we evaluate ex vivo breast tissue and corresponding quantified hematoxylin & eosin images to correlate optical scattering signatures to tissue composition stratified by patient characteristics. Adipose sites (213) were characterized by their cell area and density. All other benign and malignant sites (181) were quantified using a grid method to determine composition. The relationships between mean reduced scattering coefficient (), and % adipose, % collagen, % glands, adipocyte cell area, and adipocyte density were investigated. These relationships were further stratified by age, menopausal status, body mass index (BMI), and breast density. We identified a positive correlation between and % collagen and a negative correlation between and age and BMI. Increased collagen corresponded to increased variability. In postmenopausal women, was similar regardless of fibroglandular content. Contributions from collagen and glands to were independent and equivalent in benign sites; glands showed a stronger positive correlation than collagen to in malignant sites. Our data suggest that scattering could differentiate highly scattering malignant from benign tissues in postmenopausal women. The relationship between scattering and tissue composition will support improved scattering models and technologies to enhance intraoperative optical margin assessment.

Assessment of ablative margin after radiofrequency ablation for hepatocellular carcinoma; comparison between magnetic resonance imaging with ferucarbotran and enhanced CT with iodized oil deposition

International Nuclear Information System (INIS)

Koda, Masahiko; Tokunaga, Shiho; Fujise, Yuki; Kato, Jun; Matono, Tomomitsu; Sugihara, Takaaki; Nagahara, Takakazu; Ueki, Masaru; Murawaki, Yoshikazu; Kakite, Suguru; Yamashita, Eijiro

2012-01-01

Background and purpose: Our aim was to investigate whether magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation could accurately assess ablative margin when compared with enhanced computed tomography (CT) with iodized oil marking. Materials and methods: We enrolled 27 patients with 32 hepatocellular carcinomas in which iodized oil deposits were visible throughout the nodule after transcatheter arterial chemoembolization. For these nodules, radiofrequency ablation was performed after ferucarbotran administration. We then performed T2-weighted MRI after 1 week and enhanced CT after 1 month. T2-weighted MRI demonstrated the ablative margin as a low-intensity rim. We classified the margin into three grades; margin (+): high-intensity area with a continuous low-intensity rim; margin zero: high-intensity area with a discontinuous low-intensity rim; and margin (−): high-intensity area extending beyond the low-intensity rim. Results: In 28 (86%) of 32 nodules, there was agreement between MRI and CT. The overall agreement between for the two modalities in the assessment of ablative margin was good (κ = 0.759, 95% confidence interval: 0.480–1.000, p < 0.001). In four nodules, ablative margins on MRI were underestimated by one grade compared with CT. Conclusion: MRI using ferucarbotran is less invasive and allows earlier assessment than CT. The MRI technique performed similarly to enhanced CT with iodized oil marking in evaluating the ablative margin after radiofrequency ablation.

Assessment of unhealthy days of urban marginal inhabitants and effective factors in Mashhad, Iran

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Maliheh Ziaee

2016-01-01

Full Text Available Background: The concept of the quality of life (HRQOL related to health and its determinants contain aspects of quality of life that clearly affect people’s physical or mental health. One of the newest ways to assess the health and also the quality of life-related to health is the self-assessed health of the individual. The aim of the present study was assessment of unhealthy days, self-reported health status, and its influencing factors on residents of the marginalpart of Mashhad, Iran. Methods: In the current cross-sectional study, 580 citizens of the marginal regions and slum areas of Mashhad city were enrolled through cluster sampling method using governmental health care services divisions. The Persian version of the questionnaire CDC HRQOL-4 was used to measure the unhealthy days. Data was analyzed using SPSS, version 11.5, running ANOVA, chi-square, and t-tests. P-value of less than 0.05 was considered as statistically significant. Results: In the present study, 359 persons (61% were women and the mean age of participants was 32.6±11.51 years. The means of unhealthy days, physically unhealthy days, mentally unhealthy days, and days with dysfunction were found to be 7.2, 2.8, 4.1, and 1.7 days, respectively. The unhealthiest days (physical and mental were seen in unemployed people and the best to excellent health days were seen in housewives. Conclusion: Unhealthy days and days with dysfunction were reported higher in slum inhabitants, especially female, low literacy, and housewife participants. Providing the education and employment facilities for people who live in marginal city areas might decrease the unhealthy days.Keywords: Unhealthy days; Health; Urban Marginal Inhabitants; Mashhad

Assessment of Marginal Adaptation and Sealing Ability of Root Canal Sealers: An in vitro Study.

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Remy, Vimal; Krishnan, Vineesh; Job, Tisson V; Ravisankar, Madhavankutty S; Raj, C V Renjith; John, Seena

2017-12-01

This study aims to compare the marginal adaptation and sealing ability [mineral trioxide aggregate (MTA)-Fillapex, AH Plus, Endofill sealers] of root canal sealers. In the present study, the inclusion criteria include 45 single-rooted extracted mandibular premolar teeth, with single canal and complete root formation. The sectioning of the samples was done at the cementoenamel junction using a low-speed diamond disc. Step-back technique was used to prepare root canals manually. The MTA-Fillapex, AH Plus, and Endofill sealers were the three experimental sealer groups to which 45 teeth were distributed. Under scanning electron microscope (SEM), marginal gap at sealer and root dentin interface were examined at coronal and apical halves of root canal. Among the three maximum marginal adaptations were seen with AH Plus sealer (4.10 ± 0.10) which is followed by Endofill sealer (1.44 ± 0.18) and MTA-Fillapex sealer (0.80 ± 0.22). Between the coronal and apical marginal adaptation, significant statistical difference (p = 0.001) was seen in AH Plus sealer. When a Mann-Whitney U-test was done on MTA-Fillapex sealer vs AH Plus sealer and AH Plus sealer vs Endofill sealer, there was a statistically significant difference (p marginal adaptation when compared with other sealers used. For sealing space of crown wall and main cone in root canal treatment, sealers play an important role. The other advantages of sealers are that they are used to fill voids and irregularities in root channel, secondary, lateral channels, and space between applied gutta-percha cones and also act as tripper during filling.

Assessing soil quality and potential productivity - a basic approach to define and assess the marginality of land

Science.gov (United States)

Repmann, Frank; Gerwin, Werner; Freese, Dirk

2017-04-01

An ever growing demand for energy and the widely proposed switch from fossil fuels to more sustainable energy sources puts the cultivation and use of bioenergy plants into focus. However, bioenergy production on regular and fertile agricultural soils might conflict with the worldwide growing demand for food. To mitigate or omit this potential conflict, the use of low quality or marginal land for cultivation of bioenergy plants becomes favorable. Against this background the definition and assessment of land marginality and, respectively, the evaluation whether and to which extent specific areas are marginal and thus convenient for sustainable bioenergy production, becomes highly relevant. Within the framework of the EU funded Horizon 2020 project SEEMLA, we attempted to asses land marginality of designated test sites in the Ukraine, Greece and Germany by direct field survey. For that purpose, soil and site properties were investigated and evaluated by applying the Muencheberg Soil Quality Rating (SQR) method, developed at the Leibniz Centre for Agricultural Landscape Research (ZALF). The method deploys a comprehensive set of biogeophysical and chemical indicators to describe and finally evaluate the quality of the soil and site by a score ranging from 1 to 100 points. Field survey data were supported by additional laboratory tests on a representative set of soil samples. Practical field work and analysis of field and lab data from the investigated sites proved the applicability of the SQR method within the SEEMLA context. The SQR indices calculated from the field and lab data ranged from 2 to Greece and Germany, which differed considerably in respect to their characteristics. Correlating the site quality index to yield data reflecting yield estimations for common bioenergy plants such as willow (Salix sp.), black locust (Robinia pseudoacacia) and poplar (Populus sp.) cultivated at the respective test sites, revealed that SQR might additionally reflect the potential

Marginal kidney donor

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Ganesh Gopalakrishnan

2007-01-01

Full Text Available Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

Test characteristics of high frequency ultrasound in the pre-operative assessment of margins of basal cell and squamous cell carcinoma in patients undergoing Mohs micrographic surgery

Science.gov (United States)

Jambusaria-Pahlajani, Anokhi; Schmults, Chrysalyne D.; Miller, Christopher J.; Shin, Daniel; Williams, Jennifer; Kurd, Shanu K; Gelfand, Joel M.

2015-01-01

Background Non-invasive techniques to assess subclinical spread of non-melanoma skin cancer (NMSC) may improve surgical precision. High frequency ultrasound (HIFU) has shown promise to evaluate the extent of NMSC. Objective To determine the accuracy of HIFU to assess the margins of basal cell (BCC) and squamous cell carcinomas (SCC) prior to Mohs micrographic surgery (MMS). Methods We enrolled 100 patients with invasive SCC or BCC. Prior to the first stage of MMS, a Mohs surgeon delineated the intended surgical margin. Subsequently, a trained ultrasound technologist independently evaluated disease extent using the EPISCAN I-200 to evaluate tumor extent beyond this margin. The accuracy of HIFU was subsequently tested by comparison to pathology from frozen sections. Results The test characteristics of the ultrasound were sensitivity= 32%, specificity= 88%, positive predictive value= 47%, and negative predictive value=79%. Subgroup analyses demonstrated improved test characteristics for tumors larger than the median (area >1.74 cm2). Qualitative analyses showed that HIFU was less likely to identify extension from tumors with subtle areas of extension, such as small foci of dermal invasion from infiltrative SCC and micronodular BCC. Conclusions HIFU requires additional refinements to improve the preoperative determination of tumor extent prior to surgical treatment of NMSC. PMID:19018815

Assessment of Biomass Resources from Marginal Lands in APEC Economies

Energy Technology Data Exchange (ETDEWEB)

Milbrandt, A.; Overend, R. P.

2009-08-01

The goal of this study is to examine the marginal lands in Asia-Pacific Economic Cooperation (APEC) economies and evaluate their biomass productivity potential. Twelve categories of marginal lands are identified using the Global Agro-Ecological Zones system of the United Nations Food and Agriculture Organization.

Treatment of intestinal pythiosis in a dog with a combination of marginal excision, chemotherapy, and immunotherapy.

Science.gov (United States)

Schmiedt, Chad W; Stratton-Phelps, Meri; Torres, Bryan T; Bell, Dennis; Uhl, Elizabeth W; Zimmerman, Shawn; Epstein, Jason; Cornell, Karen K

2012-08-01

A 1.5-year-old mixed-breed dog was examined because of a 1-month history of anorexia, vomiting, diarrhea, and weight loss. The dog was very thin on physical examination (body condition score, 3/9). Results of all diagnostic tests were within reference limits except intestinal thickening and lymphadenopathy were identified on abdominal ultrasound examination. During exploratory laparotomy, thickening at the ileocecal-colic junction and within the transverse colon and mesenteric lymphadenopathy were identified, and the ileocecal-colic junction was resected. Histopathologic evaluation of the ileocecal-colic junction and full-thickness biopsy specimens from other sites as well as results of a serum ELISA were diagnostic for gastrointestinal Pythium insidiosum infection. Pythiosis was initially treated medically with administration of itraconazole and terbinafine by mouth, but the colonic lesion was progressive with this regimen. Two months after diagnosis, a subtotal colectomy was performed; marginal excision (0.6 cm) was obtained at the aboral margin. The dog was treated with 3 doses of a pythiosis vaccine beginning approximately 2 weeks after surgery and was continued on itraconazole and terbinafine for 5 months. Parenteral and enteral nutrition as well as considerable general supportive care were required postoperatively. Six months after treatment, the dog had a normal serum ELISA titer. Two years after treatment, the dog had returned to preoperative weight and was clinically normal. This patient had an unusually positive therapeutic response to chronic, extensive, marginally excised gastrointestinal pythiosis.

Craniocaudal Safety Margin Calculation Based on Interfractional Changes in Tumor Motion in Lung SBRT Assessed With an EPID in Cine Mode

International Nuclear Information System (INIS)

Ueda, Yoshihiro; Miyazaki, Masayoshi; Nishiyama, Kinji; Suzuki, Osamu; Tsujii, Katsutomo; Miyagi, Ken

2012-01-01

Purpose: To evaluate setup error and interfractional changes in tumor motion magnitude using an electric portal imaging device in cine mode (EPID cine) during the course of stereotactic body radiation therapy (SBRT) for non–small-cell lung cancer (NSCLC) and to calculate margins to compensate for these variations. Materials and Methods: Subjects were 28 patients with Stage I NSCLC who underwent SBRT. Respiratory-correlated four-dimensional computed tomography (4D-CT) at simulation was binned into 10 respiratory phases, which provided average intensity projection CT data sets (AIP). On 4D-CT, peak-to-peak motion of the tumor (M-4DCT) in the craniocaudal direction was assessed and the tumor center (mean tumor position [MTP]) of the AIP (MTP-4DCT) was determined. At treatment, the tumor on cone beam CT was registered to that on AIP for patient setup. During three sessions of irradiation, peak-to-peak motion of the tumor (M-cine) and the mean tumor position (MTP-cine) were obtained using EPID cine and in-house software. Based on changes in tumor motion magnitude (∆M) and patient setup error (∆MTP), defined as differences between M-4DCT and M-cine and between MTP-4DCT and MTP-cine, a margin to compensate for these variations was calculated with Stroom’s formula. Results: The means (±standard deviation: SD) of M-4DCT and M-cine were 3.1 (±3.4) and 4.0 (±3.6) mm, respectively. The means (±SD) of ∆M and ∆MTP were 0.9 (±1.3) and 0.2 (±2.4) mm, respectively. Internal target volume-planning target volume (ITV-PTV) margins to compensate for ∆M, ∆MTP, and both combined were 3.7, 5.2, and 6.4 mm, respectively. Conclusion: EPID cine is a useful modality for assessing interfractional variations of tumor motion. The ITV-PTV margins to compensate for these variations can be calculated.

Seismic Margin Assessment for Research Reactor using Fragility based Fault Tree Analysis

Energy Technology Data Exchange (ETDEWEB)

Kwag, Shinyoung; Oh, Jinho; Lee, Jong-Min; Ryu, Jeong-Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The research reactor has been often subjected to external hazards during the design lifetime. Especially, a seismic event can be one of significant threats to the failure of structure system of the research reactor. This failure is possibly extended to the direct core damage of the reactor. For this purpose, the fault tree for structural system failure leading to the core damage under an earthquake accident is developed. The failure probabilities of basic events are evaluated as fragility curves of log-normal distributions. Finally, the plant-level seismic margin is investigated by the fault tree analysis combining with fragility data and the critical path is identified. The plant-level probabilistic seismic margin assessment using the fragility based fault tree analysis was performed for quantifying the safety of research reactor to a seismic hazard. For this, the fault tree for structural system failure leading to the core damage of the reactor under a seismic accident was developed. The failure probabilities of basic events were evaluated as fragility curves of log-normal distributions.

Effect of posterior crown margin placement on gingival health.

Science.gov (United States)

Reitemeier, Bernd; Hänsel, Kristina; Walter, Michael H; Kastner, Christian; Toutenburg, Helge

2002-02-01

The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified. This study evaluated the effect of posterior crown margin placement with multivariate analysis. Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (Prisk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding. In this study, placement of crown margins was one of several parameters that affected gingival health.

Estimation of marginal costs at existing waste treatment facilities

DEFF Research Database (Denmark)

Martinez Sanchez, Veronica; Hulgaard, Tore; Hindsgaul, Claus

2016-01-01

, marginal costs were not (provided a response was initiated at the WtE to keep constant the utilized thermal capacity). Failing to systematically address and include costs in existing waste facilities in decision-making may unintendedly lead to higher overall costs at societal level. To avoid misleading...... a constant thermal load, (ii) Refused-Derived-Fuel (RDF) was included to maintain a constant thermal load, or (iii) no reaction occurred resulting in a reduced waste throughput without full utilization of the facility capacity. Results demonstrated that marginal costs of diversion from WtE were up to eleven...

Assessing mediation using marginal structural models in the presence of confounding and moderation

OpenAIRE

Coffman, Donna L.; Zhong, Wei

2012-01-01

This paper presents marginal structural models (MSMs) with inverse propensity weighting (IPW) for assessing mediation. Generally, individuals are not randomly assigned to levels of the mediator. Therefore, confounders of the mediator and outcome may exist that limit causal inferences, a goal of mediation analysis. Either regression adjustment or IPW can be used to take confounding into account, but IPW has several advantages. Regression adjustment of even one confounder of the mediator and ou...

Sci—Thur PM: Planning and Delivery — 04: Respiratory margin derivation and verification in partial breast irradiation

International Nuclear Information System (INIS)

Quirk, S; Conroy, L; Smith, WL

2014-01-01

Partial breast irradiation (PBI) following breast-conserving surgery is emerging as an effective means to achieve local control and reduce irradiated breast volume. Patients are planned on a static CT image; however, treatment is delivered while the patient is free-breathing. Respiratory motion can degrade plan quality by reducing target coverage and/or dose homogeneity. A variety of methods can be used to determine the required margin for respiratory motion in PBI. We derive geometric and dosimetric respiratory 1D margin. We also verify the adequacy of the typical 5 mm respiratory margin in 3D by evaluating plan quality for increasing respiratory amplitudes (2–20 mm). Ten PBI plans were used for dosimetric evaluation. A database of volunteer respiratory data, with similar characteristics to breast cancer patients, was used for this study. We derived a geometric 95%-margin of 3 mm from the population respiratory data. We derived a dosimetric 95%-margin of 2 mm by convolving 1D dose profiles with respiratory probability density functions. The 5 mm respiratory margin is possibly too large when 1D coverage is assessed and could lead to unnecessary normal tissue irradiation. Assessing margins only for coverage may be insufficient; 3D dosimetric assessment revealed degradation in dose homogeneity is the limiting factor, not target coverage. Hotspots increased even for the smallest respiratory amplitudes, while target coverage only degraded at amplitudes greater than 10 mm. The 5 mm respiratory margin is adequate for coverage, but due to plan quality degradation, respiratory management is recommended for patients with respiratory amplitudes greater than 10 mm

Margins for geometric uncertainty around organs at risk in radiotherapy

International Nuclear Information System (INIS)

McKenzie, Alan; Herk, Marcel van; Mijnheer, Ben

2002-01-01

Background and purpose: ICRU Report 62 suggests drawing margins around organs at risk (ORs) to produce planning organ at risk volumes (PRVs) to account for geometric uncertainty in the radiotherapy treatment process. This paper proposes an algorithm for drawing such margins, and compares the recommended margin widths with examples from clinical practice and discusses the limitations of the approach. Method: The use of the PRV defined in this way is that, despite the geometric uncertainties, the dose calculated within the PRV by the treatment planning system can be used to represent the dose in the OR with a certain confidence level. A suitable level is where, in the majority of cases (90%), the dose-volume histogram of the PRV will not under-represent the high-dose components in the OR. In order to provide guidelines on how to do this in clinical practice, this paper distinguishes types of OR in terms of the tolerance doses relative to the prescription dose and suggests appropriate margins for serial-structure and parallel-structure ORs. Results: In some instances of large and parallel ORs, the clinician may judge that the complication risk in omitting a margin is acceptable. Otherwise, for all types of OR, systematic, treatment preparation uncertainties may be accommodated by an OR→PRV margin width of 1.3Σ. Here, Σ is the standard deviation of the combined systematic (treatment preparation) uncertainties. In the case of serial ORs or small, parallel ORs, the effects of blurring caused by daily treatment execution errors (set-up and organ motion) should be taken into account. Near a region of high dose, blurring tends to shift the isodoses away from the unblurred edge as shown on the treatment planning system by an amount that may be represented by 0.5σ. This margin may be used either to increase or to decrease the margin already calculated for systematic uncertainties, depending upon the size of the tolerance dose relative to the detailed planned dose

Task Group on Safety Margins Action Plan (SMAP). Safety Margins Action Plan - Final Report

International Nuclear Information System (INIS)

Hrehor, Miroslav; Gavrilas, Mirela; Belac, Josef; Sairanen, Risto; Bruna, Giovanni; Reocreux, Michel; Touboul, Francoise; Krzykacz-Hausmann, B.; Park, Jong Seuk; Prosek, Andrej; Hortal, Javier; Sandervaag, Odbjoern; Zimmerman, Martin

2007-01-01

The international nuclear community has expressed concern that some changes in existing plants could challenge safety margins while fulfilling all the regulatory requirements. In 1998, NEA published a report by the Committee on Nuclear Regulatory Activities on Future Nuclear Regulatory Challenges. The report recognized 'Safety margins during more exacting operating modes' as a technical issue with potential regulatory impact. Examples of plant changes that can cause such exacting operating modes include power up-rates, life extension or increased fuel burnup. In addition, the community recognized that the cumulative effects of simultaneous changes in a plant could be larger than the accumulation of the individual effects of each change. In response to these concerns, CSNI constituted the safety margins action plan (SMAP) task group with the following objectives: 'To agree on a framework for integrated assessments of the changes to the overall safety of the plant as a result of simultaneous changes in plant operation / condition; To develop a CSNI document which can be used by member countries to assess the effect of plant change on the overall safety of the plant; To share information and experience.' The two approaches to safety analysis, deterministic and probabilistic, use different methods and have been developed mostly independently of each other. This makes it difficult to assure consistency between them. As the trend to use information on risk (where the term risk means results of the PSA/PRA analysis) to support regulatory decisions is growing in many countries, it is necessary to develop a method of evaluating safety margin sufficiency that is applicable to both approaches and, whenever possible, integrated in a consistent way. Chapter 2 elaborates on the traditional view of safety margins and the means by which they are currently treated in deterministic analyses. This chapter also discusses the technical basis for safety limits as they are used today

Intra-operative Cerenkov Imaging for Guiding Breast Cancer Surgery and Assessing Tumor Margins

Science.gov (United States)

2014-03-01

application, 13/492,606 • One travel award to attend WMIC in Dublin (2012) • One class taught as lead instructor ( Mechatronics system ) • Three classes...paraffin- embedded tissue: five years on. Cytometry. 1989;10:229–241. 15. Meng LJ, Fu G, Roy EJ, Suppe B, Chen CT. An ultrahigh resolution SPECT system for...residual cancer. This grant aims to develop a system to assess tumor margins during surgery, with the eventual goal of reducing re-excision surgery

Head and Neck Margin Reduction With Adaptive Radiation Therapy: Robustness of Treatment Plans Against Anatomy Changes

International Nuclear Information System (INIS)

Kranen, Simon van; Hamming-Vrieze, Olga; Wolf, Annelisa; Damen, Eugène; Herk, Marcel van; Sonke, Jan-Jakob

2016-01-01

Purpose: We set out to investigate loss of target coverage from anatomy changes in head and neck cancer patients as a function of applied safety margins and to verify a cone beam computed tomography (CBCT)–based adaptive strategy with an average patient anatomy to overcome possible target underdosage. Methods and Materials: For 19 oropharyngeal cancer patients, volumetric modulated arc therapy treatment plans (2 arcs; simultaneous integrated boost, 70 and 54.25 Gy; 35 fractions) were automatically optimized with uniform clinical target volume (CTV)–to–planning target volume margins of 5, 3, and 0 mm. We applied b-spline CBCT–to–computed tomography (CT) deformable registration to allow recalculation of the dose on modified CT scans (planning CT deformed to daily CBCT following online positioning) and dose accumulation in the planning CT scan. Patients with deviations in primary or elective CTV coverage >2 Gy were identified as candidates for adaptive replanning. For these patients, a single adaptive intervention was simulated with an average anatomy from the first 10 fractions. Results: Margin reduction from 5 mm to 3 mm to 0 mm generally led to an organ-at-risk (OAR) mean dose (D_m_e_a_n) sparing of approximately 1 Gy/mm. CTV shrinkage was mainly seen in the elective volumes (up to 10%), likely related to weight loss. Despite online repositioning, substantial systematic errors were present (>3 mm) in lymph node CTV, the parotid glands, and the larynx. Nevertheless, the average increase in OAR dose was small: maximum of 1.2 Gy (parotid glands, D_m_e_a_n) for all applied margins. Loss of CTV coverage >2 Gy was found in 1, 3, and 7 of 73 CTVs, respectively. Adaptive intervention in 0-mm plans substantially improved coverage: in 5 of 7 CTVs (in 6 patients) to 2 Gy in 0-mm plans may be identified early in treatment using dose accumulation. A single intervention with an average anatomy derived from CBCT effectively mitigates discrepancies.

Validation of micro-CT against the section method regarding the assessment of marginal leakage of sealants.

NARCIS (Netherlands)

Chen, X.; Cuijpers, V.M.J.I.; Fan, M.W.; Frencken, J.E.F.M.

2012-01-01

BACKGROUND: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface. METHODS: Pits and fissures of the occlusal surface of 10 teeth were sealed with a

Recommendations for CTV margins in radiotherapy planning for non melanoma skin cancer.

Science.gov (United States)

Khan, Luluel; Choo, Richard; Breen, Dale; Assaad, Dalal; Fialkov, Jefferey; Antonyshyn, Oleh; McKenzie, David; Woo, Tony; Zhang, Liying; Barnes, Elizabeth

2012-08-01

To provide practice guidelines for delineating clinical target volume (CTV) for radiotherapy planning of non melanoma (NMSC) skin cancers. A prospective, single arm, study. Preoperatively, a radiation oncologist outlined the boundary of a gross lesion, and drew 5-mm incremental marks in four directions from the delineated border. Under local anesthesia, the lesion was excised, and resection margins were assessed microscopically by frozen section. Once resection margins were clear, the microscopic tumor extent was calculated using the presurgical incremental markings as references. A potential relationship between the distance of microscopic tumor extension and other variables was analyzed. A total of 159 lesions in 150 consecutive patients, selected for surgical excision with frozen section assisted assessment of resection margins, were accrued. The distance of microscopic tumor extension beyond a gross lesion varied from 1mm to 15 mm, with a mean of 5.3mm. The microscopic tumor extent was positively correlated with the size of gross lesion, histology and number of surgical attempts required to obtain a clear margin. To provide a 95% or greater chance of covering microscopic disease we make the following recommendations for CTV margins; 10mm for BCC less than 2 cm, 13 mm for BCC greater than 2 cm, 11 mm for SCC less than 2 cm, and 14 mm for SCC greater than 2 cm. Tumors greater than 2 cm and SCC histology required larger margins to adequately cover the microscopic extent of disease. This information is crucial in radiation planning of NMSC. Clinicians should be cautioned, as these guidelines may not offer optimum treatment for patients with extremely large or small lesions. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Recommendations for CTV margins in radiotherapy planning for non melanoma skin cancer

International Nuclear Information System (INIS)

Khan, Luluel; Choo, Richard; Breen, Dale; Assaad, Dalal; Fialkov, Jefferey; Antonyshyn, Oleh; McKenzie, David; Woo, Tony; Zhang Liying; Barnes, Elizabeth

2012-01-01

Purpose: To provide practice guidelines for delineating clinical target volume (CTV) for radiotherapy planning of non melanoma (NMSC) skin cancers. Methods and materials: A prospective, single arm, study. Preoperatively, a radiation oncologist outlined the boundary of a gross lesion, and drew 5-mm incremental marks in four directions from the delineated border. Under local anesthesia, the lesion was excised, and resection margins were assessed microscopically by frozen section. Once resection margins were clear, the microscopic tumor extent was calculated using the presurgical incremental markings as references. A potential relationship between the distance of microscopic tumor extension and other variables was analyzed. Results: A total of 159 lesions in 150 consecutive patients, selected for surgical excision with frozen section assisted assessment of resection margins, were accrued. The distance of microscopic tumor extension beyond a gross lesion varied from 1 mm to 15 mm, with a mean of 5.3 mm. The microscopic tumor extent was positively correlated with the size of gross lesion, histology and number of surgical attempts required to obtain a clear margin. To provide a 95% or greater chance of covering microscopic disease we make the following recommendations for CTV margins; 10 mm for BCC less than 2 cm, 13 mm for BCC greater than 2 cm, 11 mm for SCC less than 2 cm, and 14 mm for SCC greater than 2 cm. Conclusions: Tumors greater than 2 cm and SCC histology required larger margins to adequately cover the microscopic extent of disease. This information is crucial in radiation planning of NMSC. Clinicians should be cautioned, as these guidelines may not offer optimum treatment for patients with extremely large or small lesions.

Addiction treatment in deprived urban areas in EU countries: Accessibility of care for people from socially marginalized groups

NARCIS (Netherlands)

Welbel, Marta; Matanov, Aleksandra; Moskalewicz, Jacek; Barros, Henrique; Canavan, Reamonn; Gabor, Edina; Gaddini, Andrea; Greacen, Tim; Kluge, Ulrike; Lorant, Vincent; Esteban Pena, Mercedes; Schene, Aart H.; Soares, Joaquim J. F.; Strassmayr, Christa; Vondrackova, Petra; Priebe, Stefan

2013-01-01

Aim: This study examines the accessibility of addiction treatment within services providing mental health care and support for people from socially marginalized groups in deprived urban areas across EU countries. Methods: Services providing mental health care and support in deprived areas of 14 EU

Radiotherapy margin design with particular consideration of high curvature CTVs

International Nuclear Information System (INIS)

Herschtal, Alan; Kron, Tomas; Fox, Chris

2009-01-01

In applying 3D conformal radiation therapy to a tumor clinical target volume (CTV), a margin is added around the CTV to account for any sources of error in the application of treatment which may result in misalignment between the CTV and the dose distribution actually delivered. The volume enclosed within the CTV plus the margin is known as the PTV, or planning target volume. The larger the errors are anticipated to be, the wider the margin will need to be to accommodate those errors. Based on the approach of van Herk et al. [''The probability of correct target dosage: Dose-population histograms for deriving treatment margins in radiotherapy,'' Int. J. Radiat. Oncol. Biol., Phys. 47(4), 1121-1135 (2000)] this paper develops the mathematical theory behind the calculation of the margin width required to ensure that the entire CTV receives sufficiently high dose with sufficiently high probability. The margin recipe developed not only considers the magnitude of the errors but also includes a term to adjust for curved CTV surfaces. In doing so, the accuracy of the margin recipe is enhanced yet remains mathematically concise enough to be readily implemented in the clinical setting. The results are particularly relevant for clinical situations in which the uncertainties in treatment are large relative to the size of the CTV.

Quantification and Assessment of Interfraction Setup Errors Based on Cone Beam CT and Determination of Safety Margins for Radiotherapy.

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Macarena Cubillos Mesías

Full Text Available To quantify interfraction patient setup-errors for radiotherapy based on cone-beam computed tomography and suggest safety margins accordingly.Positioning vectors of pre-treatment cone-beam computed tomography for different treatment sites were collected (n = 9504. For each patient group the total average and standard deviation were calculated and the overall mean, systematic and random errors as well as safety margins were determined.The systematic (and random errors in the superior-inferior, left-right and anterior-posterior directions were: for prostate, 2.5(3.0, 2.6(3.9 and 2.9(3.9mm; for prostate bed, 1.7(2.0, 2.2(3.6 and 2.6(3.1mm; for cervix, 2.8(3.4, 2.3(4.6 and 3.2(3.9mm; for rectum, 1.6(3.1, 2.1(2.9 and 2.5(3.8mm; for anal, 1.7(3.7, 2.1(5.1 and 2.5(4.8mm; for head and neck, 1.9(2.3, 1.4(2.0 and 1.7(2.2mm; for brain, 1.0(1.5, 1.1(1.4 and 1.0(1.1mm; and for mediastinum, 3.3(4.6, 2.6(3.7 and 3.5(4.0mm. The CTV-to-PTV margins had the smallest value for brain (3.6, 3.7 and 3.3mm and the largest for mediastinum (11.5, 9.1 and 11.6mm. For pelvic treatments the means (and standard deviations were 7.3 (1.6, 8.5 (0.8 and 9.6 (0.8mm.Systematic and random setup-errors were smaller than 5mm. The largest errors were found for organs with higher motion probability. The suggested safety margins were comparable to published values in previous but often smaller studies.

Comparison of marginal bone loss and implant success between axial and tilted implants in maxillary All-on-4 treatment concept rehabilitations after 5 years of follow-up.

Science.gov (United States)

Hopp, Milena; de Araújo Nobre, Miguel; Maló, Paulo

2017-10-01

There is need for more scientific and clinical information on longer-term outcomes of tilted implants compared to implants inserted in an axial position. Comparison of marginal bone loss and implant success after a 5-year follow-up between axial and tilted implants inserted for full-arch maxillary rehabilitation. The retrospective clinical study included 891 patients with 3564 maxillary implants rehabilitated according to the All-on-4 treatment concept. The follow-up time was 5 years. Linear mixed-effect models were performed to analyze the influence of implant orientation (axial/tilted) on marginal bone loss and binary logistic regression to assess the effect of patient characteristics on occurrence of marginal bone loss >2.8 mm. Only those patients with measurements of at least one axial and one tilted implant available were analyzed. This resulted in a data set of 2379 implants (1201 axial, 1178 tilted) in 626 patients (=reduced data set). Axial and tilted implants showed comparable mean marginal bone losses of 1.14 ± 0.71 and 1.19 ± 0.82 mm, respectively. Mixed model analysis indicated that marginal bone loss levels at 5 years follow up was not significantly affected by the orientation (axial/tilted) of the implants in the maxillary bone. Smoking and female gender were associated with marginal bone loss >2.8 mm in a logistic regression analysis. Five-year implant success rates were 96%. The occurrence of implant failure showed to be statistically independent from orientation. Within the limitations of this study and considering a follow-up time of 5 years, it can be concluded that tilted implants behave similarly with regards to marginal bone loss and implant success in comparison to axial implants in full-arch rehabilitation of the maxilla. Longer-term outcomes (10 years +) are needed to verify this result. © 2017 Wiley Periodicals, Inc.

Analysis of intra-fraction prostate motion and derivation of duration-dependent margins for radiotherapy using real-time 4D ultrasound

Directory of Open Access Journals (Sweden)

Eric Pei Ping Pang

2018-01-01

Full Text Available Background and purpose: During radiotherapy, prostate motion changes over time. Quantifying and accounting for this motion is essential. This study aimed to assess intra-fraction prostate motion and derive duration-dependent planning margins for two treatment techniques. Material and methods: A four-dimension (4D transperineal ultrasound Clarity® system was used to track prostate motion. We analysed 1913 fractions from 60 patients undergoing volumetric-modulated arc therapy (VMAT to the prostate. The mean VMAT treatment duration was 3.4 min. Extended monitoring was conducted weekly to simulate motion during intensity-modulated radiation therapy (IMRT treatment (an additional seven minutes. A motion-time trend analysis was conducted and the mean intra-fraction motion between VMAT and IMRT treatments compared. Duration-dependent margins were calculated and anisotropic margins for VMAT and IMRT treatments were derived. Results: There were statistically significant differences in the mean intra-fraction motion between VMAT and the simulated IMRT duration in the inferior (0.1 mm versus 0.3 mm and posterior (−0.2 versus −0.4 mm directions respectively (p ≪ 0.01. An intra-fraction motion trend inferiorly and posteriorly was observed. The recommended minimum anisotropic margins are 1.7 mm/2.7 mm (superior/inferior; 0.8 mm (left/right, 1.7 mm/2.9 mm (anterior/posterior for VMAT treatments and 2.9 mm/4.3 mm (superior/inferior, 1.5 mm (left/right, 2.8 mm/4.8 mm (anterior/posterior for IMRT treatments. Smaller anisotropic margins were required for VMAT compared to IMRT (differences ranging from 1.2 to 1.6 mm superiorly/inferiorly, 0.7 mm laterally and 1.1–1.9 mm anteriorly/posteriorly. Conclusions: VMAT treatment is preferred over IMRT as prostate motion increases with time. Larger margins should be employed in the inferior and posterior directions for both treatment durations. Duration-dependent margins should

Effect of MLC Leaf Width and PTV Margin on the Treatment Planning of Intensity-Modulated Stereotactic Radiosurgery (IMSRS) or Radiotherapy (IMSRT)

International Nuclear Information System (INIS)

Chang Jenghwa; Yenice, Kamil M.; Jiang Kailiu; Hunt, Margie; Narayana, Ashwatha

2009-01-01

We studied the effect of MLC (multileaf collimator) leaf width and PTV (planning target volume) margin on treatment planning of intensity modulated stereotactic radiosurgery (IMSRS) or radiotherapy (IMSRT). Twelve patients previously treated with IMSRS/IMSRT were retrospectively planned with 5- and 3-mm MLC leaf widths and 3- and 2-mm PTV margins using the already contoured clinical target volume and critical structures. The same beam arrangement, planning parameters, and optimization method were used in each of the 4 plans for a given patient. Each plan was normalized so that the prescription dose covered at least 99% of the PTV. Plan indices - D mean (mean dose), conformity index (CI), V 70 (volume receiving ≥ 70% of the prescription dose), and V 50 (volume receiving ≥ 50% of the prescription dose) - were calculated from the dose-volume histograms (DVHs) of the PTV, normal tissue, and organs at risk (OARs). Hypothesis testing was performed on the mean ratios of plan indices to determine the statistical significance of the relative differences. The PTV was well covered for all plans, as no significant differences were observed for D 95 , V 95 , D max , D min , and D mean of the PTV. The irradiated volume was ∼23% smaller when 2-mm instead of 3-mm PTV margin was used, but it was only reduced by ∼6% when the MLC leaf width was reduced from 5 mm to 3 mm. For normal tissue and brainstem, V 70 , V 50 , and D mean were reduced more effectively by a decrease in MLC width, while D mean of optic nerve and chiasm were more sensitive to a change in PTV margin. The DVH statistics for the PTV and normal structures from the treatment plan with 5-mm MLC and 2-mm PTV margin were equal to those with 3-mm MLC and 3-mm PTV margin. PTV margin reduction is more effective in sparing the normal tissue and OARs than a reduction in MLC leaf width. For IMSRS, where highly accurate setup and small PTV margins are routinely employed, the use of 5-mm MLC is therefore less desirable.

Risk of persistent high-grade squamous intraepithelial lesion after electrosurgical excisional treatment with positive margins: a meta-analysis

Directory of Open Access Journals (Sweden)

Caroline Alves de Oliveira

Full Text Available CONTEXT AND OBJECTIVE: Even if precursor lesions of cervical cancer are properly treated, there is a risk of persistence or recurrence. The aim here was to quantify the risks of persistence of high-grade intraepithelial squamous lesions, one and two years after cervical electrosurgical excisional treatment with positive margins. DESIGN AND SETTING: Systematic review of the literature and meta-analysis at Instituto Fernandes Figueira. METHODS: This meta-analysis was on studies published between January 1989 and July 2009 that were identified in Medline, Scopus, Embase, Cochrane, SciELO, Lilacs, Adolec, Medcarib, Paho, Wholis, Popline, ISI Web of Science and Sigle. Articles were selected if they were cohort studies on electrosurgical excisional treatment of high-grade squamous intraepithelial lesions with a minimum follow-up of one year, a histopathological outcome of persistence of these lesions and a small risk of bias. RESULTS: The search identified 7,066 articles and another 21 in the reference lists of these papers. After applying the selection and exclusion criteria, only four articles were found to have extractable data. The risk of persistence of high-grade intraepithelial lesions after one year was 11.36 times greater (95% confidence interval, CI: 5.529-23.379, P < 0.0001 in patients with positive margins and after two years, was four times greater (95% CI: 0.996-16.164, although without statistical significance. CONCLUSION: This meta-analysis confirms the importance of positive margins as an indicator of incomplete treatment after the first year of follow-up and highlights the need for appropriately chosen electrosurgical techniques based on disease location and extent, with close surveillance of these patients.

Specimen Shrinkage and Its Influence on Margin Assessment in Breast Cancer

Directory of Open Access Journals (Sweden)

Badrul H. Yeap

2007-07-01

Conclusion: Breast specimens undergo shrinkage after histological fixation, losing more than a third of their original closest free margin, whilst the tumour itself does not shrink substantially. This phenomenon has vital implications in the accuracy of margin analysis and consequent decisions on further management, including re-operation and the institution of adjuvant radiotherapy.

Seismic margin analysis technique for nuclear power plant structures

International Nuclear Information System (INIS)

Seo, Jeong Moon; Choi, In Kil

2001-04-01

In general, the Seismic Probabilistic Risk Assessment (SPRA) and the Seismic Margin Assessment(SAM) are used for the evaluation of realistic seismic capacity of nuclear power plant structures. Seismic PRA is a systematic process to evaluate the seismic safety of nuclear power plant. In our country, SPRA has been used to perform the probabilistic safety assessment for the earthquake event. SMA is a simple and cost effective manner to quantify the seismic margin of individual structural elements. This study was performed to improve the reliability of SMA results and to confirm the assessment procedure. To achieve this goal, review for the current status of the techniques and procedures was performed. Two methodologies, CDFM (Conservative Deterministic Failure Margin) sponsored by NRC and FA (Fragility Analysis) sponsored by EPRI, were developed for the seismic margin review of NPP structures. FA method was originally developed for Seismic PRA. CDFM approach is more amenable to use by experienced design engineers including utility staff design engineers. In this study, detailed review on the procedures of CDFM and FA methodology was performed

Margin estimation and disturbances of irradiation field in layer-stacking carbon-ion beams for respiratory moving targets.

Science.gov (United States)

Tajiri, Shinya; Tashiro, Mutsumi; Mizukami, Tomohiro; Tsukishima, Chihiro; Torikoshi, Masami; Kanai, Tatsuaki

2017-11-01

Carbon-ion therapy by layer-stacking irradiation for static targets has been practised in clinical treatments. In order to apply this technique to a moving target, disturbances of carbon-ion dose distributions due to respiratory motion have been studied based on the measurement using a respiratory motion phantom, and the margin estimation given by the square root of the summation Internal margin2+Setup margin2 has been assessed. We assessed the volume in which the variation in the ratio of the dose for a target moving due to respiration relative to the dose for a static target was within 5%. The margins were insufficient for use with layer-stacking irradiation of a moving target, and an additional margin was required. The lateral movement of a target converts to the range variation, as the thickness of the range compensator changes with the movement of the target. Although the additional margin changes according to the shape of the ridge filter, dose uniformity of 5% can be achieved for a spherical target 93 mm in diameter when the upward range variation is limited to 5 mm and the additional margin of 2.5 mm is applied in case of our ridge filter. Dose uniformity in a clinical target largely depends on the shape of the mini-peak as well as on the bolus shape. We have shown the relationship between range variation and dose uniformity. In actual therapy, the upper limit of target movement should be considered by assessing the bolus shape. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Is it necessary to plan with safety margins for actively scanned proton therapy?

Science.gov (United States)

Albertini, F.; Hug, E. B.; Lomax, A. J.

2011-07-01

In radiation therapy, a plan is robust if the calculated and the delivered dose are in agreement, even in the case of different uncertainties. The current practice is to use safety margins, expanding the clinical target volume sufficiently enough to account for treatment uncertainties. This, however, might not be ideal for proton therapy and in particular when using intensity modulated proton therapy (IMPT) plans as degradation in the dose conformity could also be found in the middle of the target resulting from misalignments of highly in-field dose gradients. Single field uniform dose (SFUD) and IMPT plans have been calculated for different anatomical sites and the need for margins has been assessed by analyzing plan robustness to set-up and range uncertainties. We found that the use of safety margins is a good way to improve plan robustness for SFUD and IMPT plans with low in-field dose gradients but not necessarily for highly modulated IMPT plans for which only a marginal improvement in plan robustness could be detected through the definition of a planning target volume.

Carfilzomib With or Without Rituximab in the Treatment of Waldenstrom Macroglobulinemia or Marginal Zone Lymphoma

Science.gov (United States)

2018-02-05

Marginal Zone Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Waldenstrom Macroglobulinemia; Refractory Marginal Zone Lymphoma; Refractory Waldenstrom Macroglobulinemia; Waldenstrom Macroglobulinemia

Marginal Generation Technology in the Chinese Power Market towards 2030 Based on Consequential Life Cycle Assessment

DEFF Research Database (Denmark)

Zhao, Guangling; Guerrero, Josep M.; Pei, Yingying

2016-01-01

Electricity consumption is often the hotspot of life cycle assessment (LCA) of products, industrial activities, or services. The objective of this paper is to provide a consistent, scientific, region-specific electricity-supply-based inventory of electricity generation technology for national...... and regional power grids. Marginal electricity generation technology is pivotal in assessing impacts related to additional consumption of electricity. China covers a large geographical area with regional supply grids; these are arguably equally or less integrated. Meanwhile, it is also a country with internal...

Realistic respiratory motion margins for external beam partial breast irradiation

Energy Technology Data Exchange (ETDEWEB)

Conroy, Leigh; Quirk, Sarah [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Smith, Wendy L., E-mail: wendy.smith@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Oncology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

2015-09-15

Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

Realistic respiratory motion margins for external beam partial breast irradiation

International Nuclear Information System (INIS)

Conroy, Leigh; Quirk, Sarah; Smith, Wendy L.

2015-01-01

Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

[Opinions and attitudes of clinical staff on systems for the assessment and treatment of children's pain].

Science.gov (United States)

Ullan, A M; Fernández, E; Badia, M; Lorente, F; Malmierca, F; Zapatero, I

2013-08-01

Many factors affect the assessment and treatment of pain, among them being the knowledge and attitudes of clinical staff. The goal of this work was to determine the opinions and attitudes of clinical staff from two hospitals on the different aspects of the assessment and treatment of children's pain. A cross-sectional, descriptive study was conducted using a self-administered questionnaire issued to clinical staff. The questionnaire was given to the professionals, doctors, and nursing staff of the paediatric services of two hospitals, and to an incidental sample of paediatric doctors. Of the 146 questionnaires sent out, 105 were completed. Participants indicated that standardised scales and physiological recordings were the least frequently used methods to assess children's pain. Participants considered that pharmacological techniques for the treatment of pain were used more frequently than non-pharmacological techniques, at all ages. Participants acknowledged being significantly more knowledgeable about pharmacological methods to relieve paediatric pain than about non-pharmacological methods. There is margin for improvement in systems for the assessment and treatment of children's pain as regards the more frequent and standardised use of techniques and standardised tools for the assessment of pain, and the greater administration of non-pharmacological strategies for its treatment. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Environmental integrated impact assessment for waste treatment activity: methodology and case-study application

International Nuclear Information System (INIS)

Lonati, G.; Panzeri, A.

2008-01-01

A literature method for the environmental integrated impact assessment, according to the IPPC Directive, has been critically analysed and adjusted in order to be used for the environmental performance assessment of waste treatment activities. The assessment parameters, sorted in eight treatment and combined pollution categories, have been partly redefined and re balanced. The adjusted methodology has been applied to a real case-study, a chemical- physical waste treatment plant, in order to calculate the current performance (Actual Integrated Index) and the ideal performance (Actual Integrated Index) achievable by technical and operational improvements. The adjusted methodology has also been used as a decision support system, in order to estimate the value of the expected environmental performances improvement after the execution achievable from the introduction of a single one or a set of improvement actions. The valuation of the Integrated Index percentage reduction, along with the action achievable, made the best actions able to be identified, both in comparative way and in the cost-effective one. The results, 50 as Effective Integrated Index and 42 as Ideal Integrated Index, in a 10-100 scale, show a medium impact level and point out an appreciable improvement margin on all the environmental performances, especially in air emission control and water consumption [it

Safety assessment for the passive system of the nuclear power plants (NPPs) using safety margin estimation

International Nuclear Information System (INIS)

Woo, Tae-Ho; Lee, Un-Chul

2010-01-01

The probabilistic safety assessment (PSA) for gas-cooled nuclear power plants has been investigated where the operational data are deficient, because there is not any commercial gas-cooled nuclear power plant. Therefore, it is necessary to use the statistical data for the basic event constructions. Several estimations for the safety margin are introduced for the quantification of the failure frequency in the basic event, which is made by the concept of the impact and affordability. Trend of probability of failure (TPF) and fuzzy converter (FC) are introduced using the safety margin, which shows the simplified and easy configurations for the event characteristics. The mass flow rate in the natural circulation is studied for the modeling. The potential energy in the gravity, the temperature and pressure in the heat conduction, and the heat transfer rate in the internal stored energy are also investigated. The values in the probability set are compared with those of the fuzzy set modeling. Non-linearity of the safety margin is expressed by the fuzziness of the membership function. This artificial intelligence analysis of the fuzzy set could enhance the reliability of the system comparing to the probabilistic analysis.

Treatment of Passive Component Reliability in Risk-Informed Safety Margin Characterization FY 2010 Report

Energy Technology Data Exchange (ETDEWEB)

Robert W Youngblood

2010-09-01

The Risk-Informed Safety Margin Characterization (RISMC) pathway is a set of activities defined under the U.S. Department of Energy (DOE) Light Water Reactor Sustainability Program. The overarching objective of RISMC is to support plant life-extension decision-making by providing a state-of-knowledge characterization of safety margins in key systems, structures, and components (SSCs). A technical challenge at the core of this effort is to establish the conceptual and technical feasibility of analyzing safety margin in a risk-informed way, which, unlike conventionally defined deterministic margin analysis, is founded on probabilistic characterizations of SSC performance.

Assessment of margins in resection specimens for head and neck malignancies.

Science.gov (United States)

Janjua, Omer Sefvan; Ahmed, Waseem; Qureshi, Sana Mehmood; Khan, Tariq Sarfaraz; Ahmed, Ashfaq; Alamgir, Wajiha

2013-04-01

To determine the relative frequency of clear, close and involved margins in resection specimens for head and neck malignancies. An observational study. The Department of Oral and Maxillofacial Surgery, Armed Forces Institute of Dentistry, Rawalpindi and the Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, from January 2008 to December 2010. Tumour registers and computer data bases in the department of Histopathology of Armed Forces Institute of Pathology, Rawalpindi, were analyzed for the cases of malignancies involving head and neck region that were sent for histopathological analysis after resection in the last three years. Histopathology reports were obtained. The data regarding age, gender, site, type of malignancy and margin status (clear, close or involved) was recorded on specially designed proformas for the study and later on analyzed by using SPSS version 17.0. Results were expressed. A total of 319 cases were registered in the study duration. The age of the patients ranged from 22-90 years (mean 59.5 + 14.1 years). Male to female ratio was 1.53:1. One hundred and thirty six (42.6%) were squamous cell carcinoma (SCC), 163 were basal cell carcinomas (BCC, 51.0%); the rest included 18 salivary gland malignancies (5.7%) and one carcino-sarcoma (0.31%) and chondrosarcoma each. All margins were found clear in 137 patients (42.9%); involved in 168 cases (52.7%) and close in 14 cases (4.4%). Margin clearance could not be achieved in more than 50% cases, this can lead to poor prognosis. Hence, methods should be adopted to improve the margin clearance in various head and neck malignancies.

Assessment of margins in resection specimens for head and neck malignancies

International Nuclear Information System (INIS)

Janjua, O. S.; Ahmed, W.; Ahmed, A.; Qureshi, S. M.; Khan, T. S.; Alamgir, W.

2013-01-01

Objective: To determine the relative frequency of clear, close and involved margins in resection specimens for head and neck malignancies. Study Design: An observational study. Place and Duration of Study: The Department of Oral and Maxillofacial Surgery, Armed Forces Institute of Dentistry, Rawalpindi and the Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, from January 2008 to December 2010. Methodology: Tumour registers and computer data bases in the department of Histopathology of Armed Forces Institute of Pathology, Rawalpindi, were analyzed for the cases of malignancies involving head and neck region that were sent for histopathological analysis after resection in the last three years. Histopathology reports were obtained. The data regarding age, gender, site, type of malignancy and margin status (clear, close or involved) was recorded on specially designed proformas for the study and later on analyzed by using SPSS version 17.0. Results were expressed. Results: A total of 319 cases were registered in the study duration. The age of the patients ranged from 22 - 90 years (mean 59.5 + 14.1 years). Male to female ratio was 1.53:1. One hundred and thirty six (42.6%) were squamous cell carcinoma (SCC), 163 were basal cell carcinomas (BCC, 51.0%); the rest included 18 salivary gland malignancies (5.7%) and one carcino-sarcoma (0.31%) and chondrosarcoma each. All margins were found clear in 137 patients (42.9%); involved in 168 cases (52.7%) and close in 14 cases (4.4%). Conclusion: Margin clearance could not be achieved in more than 50% cases, this can lead to poor prognosis. Hence, methods should be adopted to improve the margin clearance in various head and neck malignancies. (author)

A margin-based analysis of the dosimetric impact of motion on step-and-shoot IMRT lung plans

International Nuclear Information System (INIS)

Waghorn, Benjamin J; Shah, Amish P; Rineer, Justin M; Langen, Katja M; Meeks, Sanford L

2014-01-01

Intrafraction motion during step-and-shoot (SNS) IMRT is known to affect the target dosimetry by a combination of dose blurring and interplay effects. These effects are typically managed by adding a margin around the target. A quantitative analysis was performed, assessing the relationship between target motion, margin size, and target dosimetry with the goal of introducing new margin recipes. A computational algorithm was used to calculate 1,174 motion-encoded dose distributions and DVHs within the patient’s CT dataset. Sinusoidal motion tracks were used simulating intrafraction motion for nine lung tumor patients, each with multiple margin sizes. D 95% decreased by less than 3% when the maximum target displacement beyond the margin experienced motion less than 5 mm in the superior-inferior direction and 15 mm in the anterior-posterior direction. For target displacements greater than this, D 95% decreased rapidly. Targets moving in excess of 5 mm outside the margin can cause significant changes to the target. D 95% decreased by up to 20% with target motion 10 mm outside the margin, with underdosing primarily limited to the target periphery. Multi-fractionated treatments were found to exacerbate target under-coverage. Margins several millimeters smaller than the maximum target displacement provided acceptable motion protection, while also allowing for reduced normal tissue morbidity

A margin model to account for respiration-induced tumour motion and its variability

International Nuclear Information System (INIS)

Coolens, Catherine; Webb, Steve; Evans, Phil M; Shirato, H; Nishioka, K

2008-01-01

In order to reduce the sensitivity of radiotherapy treatments to organ motion, compensation methods are being investigated such as gating of treatment delivery, tracking of tumour position, 4D scanning and planning of the treatment, etc. An outstanding problem that would occur with all these methods is the assumption that breathing motion is reproducible throughout the planning and delivery process of treatment. This is obviously not a realistic assumption and is one that will introduce errors. A dynamic internal margin model (DIM) is presented that is designed to follow the tumour trajectory and account for the variability in respiratory motion. The model statistically describes the variation of the breathing cycle over time, i.e. the uncertainty in motion amplitude and phase reproducibility, in a polar coordinate system from which margins can be derived. This allows accounting for an additional gating window parameter for gated treatment delivery as well as minimizing the area of normal tissue irradiated. The model was illustrated with abdominal motion for a patient with liver cancer and tested with internal 3D lung tumour trajectories. The results confirm that the respiratory phases around exhale are most reproducible and have the smallest variation in motion amplitude and phase (approximately 2 mm). More importantly, the margin area covering normal tissue is significantly reduced by using trajectory-specific margins (as opposed to conventional margins) as the angular component is by far the largest contributor to the margin area. The statistical approach to margin calculation, in addition, offers the possibility for advanced online verification and updating of breathing variation as more data become available

Intraoperative monitoring of marginal mandibular nerve during neck dissection.

Science.gov (United States)

Tirelli, Giancarlo; Bergamini, Pier Riccardo; Scardoni, Alessandro; Gatto, Annalisa; Boscolo Nata, Francesca; Marcuzzo, Alberto Vito

2018-05-01

The purpose of this study was to assess the efficacy of intraoperative nerve integrity monitoring (NIM) to prevent marginal mandibular nerve injuries during neck dissection. This prospective study compared 36 patients undergoing NIM-assisted neck dissection from July 2014 to March 2015 to a cohort of 35 patients subjected to neck dissection over an identical period of time before the technique was introduced. We also assessed possible correlations between marginal mandibular nerve injuries and other factors, such as anthropometric measurements, presence of clinical neck metastases, type of neck dissection, and site of primary tumor. The incidence of marginal mandibular nerve paralyses was significantly lower among the group of patients undergoing NIM-assisted neck dissection (P = .021). There was no significant difference in the duration of the procedure, and the technique resulted in a limited increase of cost. No other factor seemed to influence the onset of marginal mandibular nerve palsy. In our opinion, NIM is a valuable aid for preventing marginal mandibular nerve injuries during neck dissection. © 2018 Wiley Periodicals, Inc.

A methodology to determine margins by EPID measurements of patient setup variation and motion as applied to immobilization devices

International Nuclear Information System (INIS)

Prisciandaro, Joann I.; Frechette, Christina M.; Herman, Michael G.; Brown, Paul D.; Garces, Yolanda I.; Foote, Robert L.

2004-01-01

Assessment of clinic and site specific margins are essential for the effective use of three-dimensional and intensity modulated radiation therapy. An electronic portal imaging device (EPID) based methodology is introduced which allows individual and population based CTV-to-PTV margins to be determined and compared with traditional margins prescribed during treatment. This method was applied to a patient cohort receiving external beam head and neck radiotherapy under an IRB approved protocol. Although the full study involved the use of an EPID-based method to assess the impact of (1) simulation technique (2) immobilization, and (3) surgical intervention on inter- and intrafraction variations of individual and population-based CTV-to-PTV margins, the focus of the paper is on the technique. As an illustration, the methodology is utilized to examine the influence of two immobilization devices, the UON TM thermoplastic mask and the Type-S TM head/neck shoulder immobilization system on margins. Daily through port images were acquired for selected fields for each patient with an EPID. To analyze these images, simulation films or digitally reconstructed radiographs (DRR's) were imported into the EPID software. Up to five anatomical landmarks were identified and outlined by the clinician and up to three of these structures were matched for each reference image. Once the individual based errors were quantified, the patient results were grouped into populations by matched anatomical structures and immobilization device. The variation within the subgroup was quantified by calculating the systematic and random errors (Σ sub and σ sub ). Individual patient margins were approximated as 1.65 times the individual-based random error and ranged from 1.1 to 6.3 mm (A-P) and 1.1 to 12.3 mm (S-I) for fields matched on skull and cervical structures, and 1.7 to 10.2 mm (L-R) and 2.0 to 13.8 mm (S-I) for supraclavicular fields. Population-based margins ranging from 5.1 to 6.6 mm (A

Positive Surgical Margins in Favorable-Stage Differentiated Thyroid Cancer.

Science.gov (United States)

Mercado, Catherine E; Drew, Peter A; Morris, Christopher G; Dziegielewski, Peter T; Mendenhall, William M; Amdur, Robert J

2018-04-16

The significance of positive margin in favorable-stage well-differentiated thyroid cancer is controversial. We report outcomes of positive-margin patients with a matched-pair comparison to a negative-margin group. A total of 25 patients with classic-histology papillary or follicular carcinoma, total thyroidectomy +/- node dissection, stage T1-3N0-1bM0, positive surgical margin at primary site, adjuvant radioactive iodine (I-131), and age older than 18 years were treated between 2003 and 2013. Endpoints were clinical and biochemical (thyroglobulin-only) recurrence-free survival. Matched-pair analysis involved a 1:1 match with negative-margin cases matched for overall stage and I-131 dose. Recurrence-free survival in positive-margin patients was 71% at 10 years. No patient was successfully salvaged with additional treatment. Only 1 patient died of thyroid cancer. Recurrence-free survival at 10 years was worse with a positive (71%) versus negative (90%) margin (P=0.140). Cure with a microscopically positive margin was suboptimal (71%) despite patients having classic-histology papillary and follicular carcinoma, favorable stage, and moderate-dose I-131 therapy.

Evaluation of motion management strategies based on required margins

International Nuclear Information System (INIS)

Sawkey, D; Svatos, M; Zankowski, C

2012-01-01

Strategies for delivering radiation to a moving lesion each require a margin to compensate for uncertainties in treatment. These motion margins have been determined here by separating the total uncertainty into components. Probability density functions for the individual sources of uncertainty were calculated for ten motion traces obtained from the literature. Motion margins required to compensate for the center of mass motion of the clinical treatment volume were found by convolving the individual sources of uncertainty. For measurements of position at a frequency of 33 Hz, system latency was the dominant source of positional uncertainty. Averaged over the ten motion traces, the motion margin for tracking with a latency of 200 ms was 4.6 mm. Gating with a duty cycle of 33% required a mean motion margin of 3.2–3.4 mm, and tracking with a latency of 100 ms required a motion margin of 3.1 mm. Feasible reductions in the effects of the sources of uncertainty, for example by using a simple prediction algorithm to anticipate the lesion position at the end of the latency period, resulted in a mean motion margin of 1.7 mm for tracking with a latency of 100 ms, 2.4 mm for tracking with a latency of 200 ms, and 2.1–2.2 mm for the gating strategies with duty cycles of 33%. A crossover tracking latency of 150 ms was found, below which tracking strategies could take advantage of narrower motion margins than gating strategies. The methods described here provide a means to guide selection of a motion management strategy for a given patient. (paper)

Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

Directory of Open Access Journals (Sweden)

Niyom Lue

Full Text Available There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS and intrinsic fluorescence spectroscopy (IFS, and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm over a wide field of view (10 cm × 10 cm, and both high spectral resolution (2 nm and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue. Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error. Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a

Margin benefit assessment of the YGN 3 cycle 1 fxy error files for COLSS and CPC overall uncertainty analyses

International Nuclear Information System (INIS)

Yoon, Rae Young; In, Wang Kee; Auh, Geun Sun; Kim, Hee Cheol; Lee, Sang Keun

1994-01-01

Margin benefits are quantitatively assessed for the Yonggwang Unit 3 (YGN 3) Cycle 1 planar radial peaking factor (Fxy) error files for each time-in-life, i.e., BOC, IOC, MOC and EOC. The generic Fxy error file (FXYMEQO) is presently used for Yonggwang Unit 3 Cycle 1 COLSS (Core Operating Limit Supervisory System) and CPC (Core Protection Calculator) Overall Uncertainty Analyses (OUA). However, because this file is more conservative than the plant/cycle specific Fxy error files, COLSS and CPC thermal margins (DNB-OPM) for the generic Fxy error file are less than those of the plant/cycle specific Fxy error file. Therefore, the YGN 3 Cycle 1 Fxy error files were generated and analyzed by the modified codes for Yonggwang Plants. The YGN 3 Cycle 1 Fxy error files gave the increased thermal margin by about 1% for COLSS and CPC, respectively

Inserting ex vivo fluorescence confocal microscopy perioperatively in Mohs micrographic surgery expedites bedside assessment of excision margins in recurrent basal cell carcinoma.

Science.gov (United States)

Longo, Caterina; Ragazzi, Moira; Castagnetti, Fabio; Gardini, Stefano; Palmieri, Tamara; Lallas, Aimilios; Moscarella, Elvira; Piana, Simonetta; Pellacani, Giovanni; Zalaudek, Iris; Argenziano, Giuseppe

2013-01-01

Mohs micrographic surgery can be employed in recurrent basal cell carcinoma, although it is a time-consuming technique. Recently, ex vivo fluorescence confocal microscopy (FCM) has been employed to obtain a fast assessment of tumor margins at the bedside. In our case we successfully employed ex vivo FCM to assess the tumor margins and we treated the persistent tumor with intensity-modulated radiation therapy. Our case demonstrates that a multidisciplinary approach is very efficient in managing complex and recurrent tumors and highlights the benefits of FCM as a new technique that can be used in the surgical theater to speed up the entire procedure.

Is perforated marginal ulcer after the surgery of gastroduodenal ulcer associated with inadequate treatment for Helicobacter pylori eradication?

Science.gov (United States)

Aydinli, Bulent; Yilmaz, Omer; Ozturk, Gurkan; Yildigan, M Ilhan; Gursan, Nesrin; Basoglu, Mahmut

2007-09-01

A marginal ulcer developing after an initial operation for gastroduodenal ulcer is a serious threat to the patient, and a challenge to surgeons. Helicobacter pylori is the primary cause of peptic ulcer disease. However, its role in ulcer recurrence, especially of marginal ulcer (MU), after peptic ulcer surgery is unclear. This study aimed to determine any association between H. pylori infection and perforated MU by comparing the prevalence of H. pylori and nonsteroidal anti-inflammatory drugs (NSAIDs) use in patients with perforated (PMU) and in those with nonperforated MU (NPMU). The study retrospectively evaluated the records of 16 patients with PMU who underwent surgical treatment and 24 patients with NPMU who underwent medical treatment in Atatürk University, School of Medicine, Department of General Surgery and Gastroenterology, between January 1995 and December 2004. The rate of H. pylori in the PMU group was significantly higher than that of the NPMU group (P PMU compared with NPMU patients (P PMU (P PMU operation especially in cases with impaired hemodynamics, severe peritoneal contamination, and/or a diameter smaller than 1 cm and avoiding the use of NSAIDs will surely reduce the risk of relapsing ulcers.

On probabilistically defined margins in radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Papiez, Lech; Langer, Mark [Department of Radiation Oncology, Indiana University, Indianapolis, IN (United States)

2006-08-21

Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

On probabilistically defined margins in radiation therapy

International Nuclear Information System (INIS)

Papiez, Lech; Langer, Mark

2006-01-01

Margins about a target volume subject to external beam radiation therapy are designed to assure that the target volume of tissue to be sterilized by treatment is adequately covered by a lethal dose. Thus, margins are meant to guarantee that all potential variation in tumour position relative to beams allows the tumour to stay within the margin. Variation in tumour position can be broken into two types of dislocations, reducible and irreducible. Reducible variations in tumour position are those that can be accommodated with the use of modern image-guided techniques that derive parameters for compensating motions of patient bodies and/or motions of beams relative to patient bodies. Irreducible variations in tumour position are those random dislocations of a target that are related to errors intrinsic in the design and performance limitations of the software and hardware, as well as limitations of human perception and decision making. Thus, margins in the era of image-guided treatments will need to accommodate only random errors residual in patient setup accuracy (after image-guided setup corrections) and in the accuracy of systems designed to track moving and deforming tissues of the targeted regions of the patient's body. Therefore, construction of these margins will have to be based on purely statistical data. The characteristics of these data have to be determined through the central limit theorem and Gaussian properties of limiting error distributions. In this paper, we show how statistically determined margins are to be designed in the general case of correlated distributions of position errors in three-dimensional space. In particular, we show how the minimal margins for a given level of statistical confidence are found. Then, how they are to be used to determine geometrically minimal PTV that provides coverage of GTV at the assumed level of statistical confidence. Our results generalize earlier recommendations for statistical, central limit theorem

Texas curve margin of safety.

Science.gov (United States)

2013-01-01

This software can be used to assist with the assessment of margin of safety for a horizontal curve. It is intended for use by engineers and technicians responsible for safety analysis or management of rural highway pavement or traffic control devices...

Seismic margin review of the Maine Yankee Atomic Power Station: Fragility analysis

International Nuclear Information System (INIS)

Ravindra, M.K.; Hardy, G.S.; Hashimoto, P.S.; Griffin, M.J.

1987-03-01

This Fragility Analysis is the third of three volumes for the Seismic Margin Review of the Maine Yankee Atomic Power Station. Volume 1 is the Summary Report of the first trial seismic margin review. Volume 2, Systems Analysis, documents the results of the systems screening for the review. The three volumes are part of the Seismic Margins Program initiated in 1984 by the Nuclear Regulatory Commission (NRC) to quantify seismic margins at nuclear power plants. The overall objectives of the trial review are to assess the seismic margins of a particular pressurized water reactor, and to test the adequacy of this review approach, quantification techniques, and guidelines for performing the review. Results from the trial review will be used to revise the seismic margin methodology and guidelines so that the NRC and industry can readily apply them to assess the inherent quantitative seismic capacity of nuclear power plants

Seismic margin review of the Maine Yankee Atomic Power Station: Fragility analysis

Energy Technology Data Exchange (ETDEWEB)

Ravindra, M. K.; Hardy, G. S.; Hashimoto, P. S.; Griffin, M. J.

1987-03-01

This Fragility Analysis is the third of three volumes for the Seismic Margin Review of the Maine Yankee Atomic Power Station. Volume 1 is the Summary Report of the first trial seismic margin review. Volume 2, Systems Analysis, documents the results of the systems screening for the review. The three volumes are part of the Seismic Margins Program initiated in 1984 by the Nuclear Regulatory Commission (NRC) to quantify seismic margins at nuclear power plants. The overall objectives of the trial review are to assess the seismic margins of a particular pressurized water reactor, and to test the adequacy of this review approach, quantification techniques, and guidelines for performing the review. Results from the trial review will be used to revise the seismic margin methodology and guidelines so that the NRC and industry can readily apply them to assess the inherent quantitative seismic capacity of nuclear power plants.

Social Support of Patients with Type 2 Diabetes in Marginalized Contexts in Mexico and Its Relation to Compliance with Treatment: A Sociocultural Approach

Science.gov (United States)

Juárez-Ramírez, Clara; Théodore, Florence L.; Villalobos, Aremis; Jiménez-Corona, Aida; Lerin, Sergio; Nigenda, Gustavo; Lewis, Sarah

2015-01-01

Objective This study aimed to describe the ways social support works in the daily life of patients with type 2 diabetes living in conditions of social and economic marginality, in order to understand how that support relates to treatment compliance. Methods Sequential mixed methods research was used. The sample of patients was obtained from primary health care units and selected considering regional representativeness, and levels of morbidity and mortality for type 2 diabetes. Results Results point to the nuclear family as the main source of support. Regardless of the area of residence, four main dimensions of support were identified: economic support, help with treatment compliance, emotional support, and material aid. Conclusions We conclude that the support network assists the patient in different ways and helps cope with the disease, but in conditions of social and economic marginality, does not guarantee the quality of attention nor enable the self-management of treatment. PMID:26545122

Sustainable food production in marginal lands—Case of GDLA member countries

Directory of Open Access Journals (Sweden)

Shabbir A. Shahid

2013-06-01

Full Text Available Sustainable food production in the changing climate and dwindling water resources in the Global Dry Land Alliance (GDLA member countries is a real challenge, especially when considering marginal lands in dryland systems. The definition of marginal land is very vague and defined from different perspectives (pragmatism about marginal lands. Dryland itself indicates "marginality" due to water stress. In general, the abandoned agriculture land where food production is not economical, and has low inherent productivity potential is considered marginal; however, a land may be marginal for agriculture but vital for grazing. In this paper attempts have been made to give review of literature (water stress, extent of marginal saline lands, marginality. Policy matters (development of soil, water and agriculture strategies that GDLA and member countries should consider for future sustainable food production in their countries, including but not limited to, assessment of land resources for agriculture potential, defining, mapping and characterizing marginal lands, and use of innovative technologies (conservation agriculture, climate smart agriculture, integrated soil reclamation program and capacity building for food production, are discussed. The international perception (FAO, UNEP, CGIAR on marginal lands is also described. An innovative approach of using national biocapacity and ecological footprint is used to assess marginality of GDLA member countries. Ecological overshoot (using 1.5 earth planets and biocapacity debtor and creditor countries are highlighted. Challenges and best management practices for food production in marginal lands are included. Other important issues, like leasing land abroad, GDLA strategic food reserves and best management practices, innovative ideas for food production are shared. Finally recommendations are drafted for actions by GDLA, its member countries and the partners.

Outcomes in breast cancer patients relative to margin status after treatment with breast-conserving surgery and radiation therapy: the University of Pennsylvania experience

International Nuclear Information System (INIS)

Peterson, Michael E.; Schultz, Delray J.; Reynolds, Carol; Solin, Lawrence J.

1999-01-01

Purpose: To evaluate the significance of final microscopic resection margin status on treatment outcomes in women with early breast cancer who are treated with breast-conserving surgery and definitive breast irradiation. Methods and Materials: An analysis was performed of 1021 consecutive women with clinical Stage I or II invasive carcinoma of the breast treated with breast-conserving surgery and definitive breast irradiation. Complete gross excision of tumor was performed in all cases, and an axillary staging procedure was performed to determine pathologic axillary lymph node status. The 1021 patients were divided into four groups based on the final microscopic margin from the tumor excision or from the re-excision if performed. These four groups were: (a) 518 patients with negative margins; (b) 124 patients with focally positive margins; (c) 96 patients with focally close margins (≤ 2 mm); and (d) 283 patients with unknown margins. Results: Local failure was not significantly different in patients with negative, focally positive, focally close or unknown final pathologic margins of resection at 8 years (8% vs. 10% vs. 17% vs. 16%, respectively, p = 0.21). The 8-year outcome also was not different among the four groups for overall survival (86% vs. 83% vs. 88% vs. 81%, respectively, p = 0.13), cause-specific survival (89% vs. 86% vs. 88% vs. 83%, respectively, p 0.14), no evidence of disease survival (81% vs. 73% vs. 86% vs. 77%, respectively, p = 0.09), and freedom from distant metastases (85% vs. 75% vs. 86% vs. 79%, respectively, p = 0.08). Conclusion: These results demonstrate that selected patients with focally positive or focally close microscopic resection margins can be treated with breast-conserving surgery and definitive breast irradiation with 8-year local control rates and survival rates that are similar to those seen in breast-conservation patients with negative or unknown final resection margins

Effect of Margin Designs on the Marginal Adaptation of Zirconia Copings.

Science.gov (United States)

Habib, Syed Rashid; Al Ajmi, Mohammed Ginan; Al Dhafyan, Mohammed; Jomah, Abdulrehman; Abualsaud, Haytham; Almashali, Mazen

2017-09-01

The aim of this in vitro study was to investigate the effect of Shoulder versus Chamfer margin design on the marginal adaptation of zirconia (Zr) copings. 40 extracted molar teeth were mounted in resin and prepared for zirconia crowns with two margin preparation designs (20=Shoulder and 20=Chamfer). The copings were manufactured by Cercon® (DeguDent GmbH, Germany) using the CAD/CAM system for each tooth. They were tried on each tooth, cemented, thermocycled, re-embedded in resin and were subsequently cross sectioned centrally into two equal mesial and distal halves. They were examined under electron microscope at 200 X magnification and the measurements were recorded at 5 predetermined points in micrometers (µm). The o verall mean marginal gap for the two groups was found to be 206.98+42.78µm with Shoulder margin design (Marginal Gap=199.50+40.72µm) having better adaptation compared to Chamfer (Marginal Gap=214.46+44.85µm). The independent-samples t-test showed a statistically non-significant difference (p=.113) between the means of marginal gap for Shoulder and Chamfer margin designs and the measurements were recorded at 5 predetermined points for the two groups. The Chamfer margin design appeared to offer the same adaptation results as the Shoulder margin design.

Identifying technology innovations for marginalized smallholders-A conceptual approach.

Science.gov (United States)

Malek, Mohammad Abdul; Gatzweiler, Franz W; Von Braun, Joachim

2017-05-01

This paper adds a contribution in the existing literature in terms of theoretical and conceptual background for the identification of idle potentials of marginal rural areas and people by means of technological and institutional innovations. The approach follows ex-ante assessment for identifying suitable technology and institutional innovations for marginalized smallholders in marginal areas-divided into three main parts (mapping, surveying and evaluating) and several steps. Finally, it contributes to the inclusion of marginalized smallholders by an improved way of understanding the interactions between technology needs, farming systems, ecological resources and poverty characteristics in the different segments of the poor, and to link these insights with productivity enhancing technologies.

SU-F-P-40: Analysis of Pelvic Lymph Node Margin Using Prostate Fiducial Markers, for SBRT Treatments

Energy Technology Data Exchange (ETDEWEB)

Torres, J; Castro Pena, P; Garrigo, E; Zunino, S; Venencia, C [Instituto de Radioterapia - Fundacion Marie Curie, Cordoba (Argentina)

2016-06-15

Purpose: The use of fiducials markers in prostate treatment allows a precise localization of this volume. Typical prostate SBRT margins with fiducials markers are 5mm in all directions, except toward the rectum, where 3mm is used. For some patients nearby pelvic lymph nodes with 5mm margin need to be irradiate assuming that its localization is linked to the prostate fiducial markers instead of bony anatomy. The purpose of this work was to analyze the geometric impact of locate the lymph node regions through the patient positioning by prostate fiducial markers. Methods: 10 patients with prostate SBRT with lymph nodes irradiation were selected. Each patient had 5 implanted titanium fiducial markers. A Novalis TX (BrainLAB-Varian) with ExacTrac and aSi1000 portal image was used. Treatment plan uses 11 beams with a dose prescription (D95%) of 40Gy to the prostate and 25Gy to the lymph node in 5 fractions. Daily positioning was carried out by ExacTrac system based on the implanted fiducials as the reference treatment position; further position verification was performed using the ExacTrac and two portal images (gantry angle 0 and 90) based on bony structures. Comparison between reference position with bony based ExacTrac and portal image localization, was done for each treatment fraction Results: A total of 50 positioning analysis were done. The average discrepancy between reference treatment position and ExacTrac based on bony anatomy (pubic area) was 4.2mm [0.3; 11.2]. The discrepancy was <5mm in 61% of the cases and <9mm in 92%. Using portal images the average discrepancy was 3.7mm [0.0; 11.1]. The discrepancy was <5mm in 69% of the cases and <9mm in 96%. Conclusion: Localizing lymph node by prostate fiducial markers may produce large discrepancy as large as 11mm compared to bony based localization. Dosimetric impact of this discrepancy should be studied.

Assessment of Long-Run Marginal Costing of Transmission and ...

African Journals Online (AJOL)

The Long-Run Marginal Costing (LRMC) technique is used as a cost-reflecting pricing method and finds useful application in the recovery of the total investment cost for the use of a transmission or distribution network. This paper reviews recent applications of this technique based on some examples from United Kingdom, ...

Pilot study of intraoperative digital imaging with the use of a mammograph for assessment of bone surgical margins in the head and neck region

International Nuclear Information System (INIS)

Ntomouchtsis, A.; Xinou, K.; Patrikidou, A.; Paraskevopoulos, K.; Kechagias, N.; Tsekos, A.; Balis, G.C.; Gerasimidou, D.; Thuau, H.; Mangoudi, D.; Vahtsevanos, K.

2013-01-01

Aim: To investigate alternative possibilities for the intraoperative evaluation of surgical margins after bone resection utilizing more conventional hospital infrastructure technologies. Materials and methods: A small pilot study was performed using digital mammograph imaging intraoperatively on 16 surgical specimens of bone tumours or malignancies with bone infiltration of the head and neck area, with the aim of evaluating the resection margins. Results: In thirteen cases the intraoperative specimen images indicated clinically complete excision. In two cases incomplete resection or close proximity of margins was detected, which required additional resection. Conclusions: The results indicated that intraoperative specimen radiography can prove useful in evaluating completeness of excision. The significance of intraoperative assessment of surgical margin is of paramount importance when immediate reconstruction is performed. This proposed method is cheap, easy to perform and fast. Its cost–benefit ratio is superior than that of any other available technique. Intraoperative analysis of specimens with digital mammography imaging can potentially become a useful tool for immediate evaluation of osseous margins after resection

Respiratory gated beam delivery cannot facilitate margin reduction, unless combined with respiratory correlated image guidance

International Nuclear Information System (INIS)

Korreman, Stine S.; Juhler-Nottrup, Trine; Boyer, Arthur L.

2008-01-01

Purpose/objective: In radiotherapy of targets moving with respiration, beam gating is offered as a means of reducing the target motion. The purpose of this study is to evaluate the safe magnitude of margin reduction for respiratory gated beam delivery. Materials/methods: The study is based on data for 17 lung cancer patients in separate protocols at Rigshospitalet and Stanford Cancer Center. Respiratory curves for external optical markers and implanted fiducials were collected using equipment based on the RPM system (Varian Medical Systems). A total of 861 respiratory curves represented external measurements over 30 fraction treatment courses for 10 patients, and synchronous external/internal measurements in single sessions for seven patients. Variations in respiratory amplitude (simulated coaching) and external/internal phase shifts were simulated by perturbation with realistic values. Variations were described by medians and standard deviations (SDs) of position distributions of the markers. Gating windows (35% duty cycle) were retrospectively applied to the respiratory data for each session, mimicking the use of commercially available gating systems. Medians and SDs of gated data were compared to those of ungated data, to assess potential margin reductions. Results: External respiratory data collected over entire treatment courses showed SDs from 1.6 to 8.1 mm, the major part arising from baseline variations. The gated data had SDs from 1.5 to 7.7 mm, with a mean reduction of 0.3 mm (6%). Gated distributions were more skewed than ungated, and in a few cases a marginal miss of gated respiration would be found even if no margin reduction was applied. Regularization of breathing amplitude to simulate coaching did not alter these results significantly. Simulation of varying phase shifts between internal and external respiratory signals showed that the SDs of gated distributions were the same as for the ungated or smaller, but the median values were markedly shifted

Patterns of failure for glioblastoma multiforme following limited-margin radiation and concurrent temozolomide

International Nuclear Information System (INIS)

Gebhardt, Brian J; Dobelbower, Michael C; Ennis, William H; Bag, Asim K; Markert, James M; Fiveash, John B

2014-01-01

To analyze patterns of failure in patients with glioblastoma multiforme (GBM) treated with limited-margin radiation therapy and concurrent temozolomide. We hypothesize that patients treated with margins in accordance with Adult Brain Tumor Consortium guidelines (ABTC) will demonstrate patterns of failure consistent with previous series of patients treated with 2–3 cm margins. A retrospective review was performed of patients treated at the University of Alabama at Birmingham for GBM between 2000 and 2011. Ninety-five patients with biopsy-proven disease and documented disease progression after treatment were analyzed. The initial planning target volume includes the T1-enhancing tumor and surrounding edema plus a 1 cm margin. The boost planning target volume includes the T1-enhancing tumor plus a 1 cm margin. The tumors were classified as in-field, marginal, or distant if greater than 80%, 20-80%, or less than 20% of the recurrent volume fell within the 95% isodose line, respectively. The median progression-free survival from the time of diagnosis to documented failure was 8 months (range 3–46). Of the 95 documented recurrences, 77 patients (81%) had an in-field component of treatment failure, 6 (6%) had a marginal component, and 27 (28%) had a distant component. Sixty-three patients (66%) demonstrated in-field only recurrence. The low rate of marginal recurrence suggests that wider margins would have little impact on the pattern of failure, validating the use of limited margins in accordance ABTC guidelines

Interaction of 2-Gy Equivalent Dose and Margin Status in Perioperative High-Dose-Rate Brachytherapy

International Nuclear Information System (INIS)

Martinez-Monge, Rafael; Cambeiro, Mauricio; Moreno, Marta; Gaztanaga, Miren; San Julian, Mikel; Alcalde, Juan; Jurado, Matias

2011-01-01

Purpose: To determine patient, tumor, and treatment factors predictive of local control (LC) in a series of patients treated with either perioperative high-dose-rate brachytherapy (PHDRB) alone (Group 1) or with PHDRB combined with external-beam radiotherapy (EBRT) (Group 2). Patient and Methods: Patients (n = 312) enrolled in several PHDRB prospective Phase I-II studies conducted at the Clinica Universidad de Navarra were analyzed. Treatment with PHDRB alone, mainly because of prior irradiation, was used in 126 patients to total doses of 32 Gy/8 b.i.d. or 40 Gy/10 b.i.d. treatments after R0 or R1 resections. Treatment with PHDRB plus EBRT was used in 186 patients to total doses of 16 Gy/4 b.i.d. or 24 Gy/6 b.i.d. treatments after R0 or R1 resections along with 45 Gy of EBRT with or without concomitant chemotherapy. Results: No dose-margin interaction was observed in Group 1 patients. In Group 2 patients there was a significant interaction between margin status and 2-Gy equivalent (Eq2Gy) dose (p = 0.002): (1) patients with negative margins had 9-year LC of 95.7% at Eq2Gy = 62.9Gy; (2) patients with close margins of >1 mm had 9-year LC of 92.4% at Eq2Gy = 72.2Gy, and (3) patients with positive/close <1-mm margins had 9-year LC of 68.0% at Eq2Gy = 72.2Gy. Conclusions: Two-gray equivalent doses ≥70 Gy may compensate the effect of close margins ≥1 mm but do not counterbalance the detrimental effect of unfavorable (positive/close <1 mm) resection margins. No dose-margin interaction is observed in patients treated at lower Eq2Gy doses ≤50 Gy with PHDRB alone.

Incorporating latitudinal and central–marginal trends in assessing genetic variation across species ranges

Science.gov (United States)

Qinfeng Guo

2012-01-01

The genetic variation across a species’ range is an important factor in speciation and conservation, yet searching for general patterns and underlying causes remains challenging. While the majority of comparisons between central and marginal populations have revealed a general central–marginal (C-M) decline in genetic diversity, others show no clear pattern. Similarly...

ATP-containing vesicles in stria vascular marginal cell cytoplasms in neonatal rat cochlea are lysosomes.

Science.gov (United States)

Liu, Jun; Liu, Wenjing; Yang, Jun

2016-02-11

We confirmed that ATP is released from cochlear marginal cells in the stria vascular but the cell organelle in which ATP stores was not identified until now. Thus, we studied the ATP-containing cell organelles and suggest that these are lysosomes. Primary cultures of marginal cells of Sprague-Dawley rats aged 1-3 days was established. Vesicles within marginal cells stained with markers were identified under confocal laser scanning microscope and transmission electron microscope (TEM). Then ATP release from marginal cells was measured after glycyl-L-phenylalanine-ß- naphthylamide (GPN) treatment using a bioluminescent assay. Quinacrine-stained granules within marginal cells were labeled with LysoTracker, a lysosome tracer, and lysosomal-associated membrane protein 1(LAMP1), but not labeled with the mitochondrial tracer MitoTracker. Furthermore, LysoTracker-labelled puncta showed accumulation of Mant-ATP, an ATP analog. Treatment with 200 μM GPN quenched fluorescently labeled puncta after incubation with LysoTracker or quinacrine, but not MitoTracker. Quinacrine-labeled organelles observed by TEM were lysosomes, and an average 27.7 percent increase in ATP luminescence was observed in marginal cells extracellular fluid after GPN treatment. ATP-containing vesicles in cochlear marginal cells of the stria vascular from neonatal rats are likely lysosomes. ATP release from marginal cells may be via Ca(2+)-dependent lysosomal exocytosis.

Extraction of data from margin calculations in prostate radiotherapy from a commercial record and verify system

International Nuclear Information System (INIS)

Fox, C.; Kron, T.; Fisher, R.; Tai, K.H.; Thompson, A.; Owen, R.

2008-01-01

Full text: Radiation therapy is a widely prescribed and effective modality for the treatment of prostate cancer.1 3 Radiation therapy relies on precise targeting of the treatment site to deliver the required dose to the tumour while sparing critical organs nearby. To achieve this, it is necessary to allow for the effects of organ and patient motion, both during and between treatment fractions. In the treatment planning process, a margin is added to the clinical target volume (CTV) to create the planning target volume (PTV) to allow for targeting uncertainties which Iare dominated by these movements.4 5 Deciding the appropriate margin size is important since an excessively large margin will result in increased damage to adjacent normal tissues while an undersized margin will leave parts of the target underdosed. With the marked improvement in technology available with new treatment machines, remote online setup correction using high quality kilovoltage images has become straightforward and widely available. Used together with implanted radio-opaque markers, remote online setup correction allows direct targeting of the prostate organ, and significant reduction in the effects of interfraction motion.6 1 1 The introduction of this technology into a therapy department makes a reduction of CTV to PTV margin size possible. There are many published works dealing with margin size calculation for prostate treatment planning. The best known and most widely cited work is that of van Herk which modelled the prostate using simple geometry to calculate a minimum dose coverage probability.13 The outcome of this modelling was a simple and easily understood formula with just the patient group random and systematic setup errors used to calculate margin size. To apply such margin recipes, the patient group's random and systematic error performance must be well known, which requires the collection of a substantial quantity of data. The aim of the project described here was to collect

Advancing optical imaging for breast margin assessment: an analysis of excisional time, cautery, and patent blue dye on underlying sources of contrast.

Directory of Open Access Journals (Sweden)

Torre M Bydlon

Full Text Available Breast conserving surgery (BCS is a recommended treatment for breast cancer patients where the goal is to remove the tumor and a surrounding rim of normal tissue. Unfortunately, a high percentage of patients return for additional surgeries to remove all of the cancer. Post-operative pathology is the gold standard for evaluating BCS margins but is limited due to the amount of tissue that can be sampled. Frozen section analysis and touch-preparation cytology have been proposed to address the surgical needs but also have sampling limitations. These issues represent an unmet clinical need for guidance in resecting malignant tissue intra-operatively and for pathological sampling. We have developed a quantitative spectral imaging device to examine margins intra-operatively. The context in which this technology is applied (intra-operative or post-operative setting is influenced by time after excision and surgical factors including cautery and the presence of patent blue dye (specifically Lymphazurin™, used for sentinel lymph node mapping. Optical endpoints of hemoglobin ([THb], fat ([β-carotene], and fibroglandular content via light scattering ( measurements were quantified from diffuse reflectance spectra of lumpectomy and mastectomy specimens using a Monte Carlo model. A linear longitudinal mixed-effects model was used to fit the optical endpoints for the cautery and kinetics studies. Monte Carlo simulations and tissue mimicking phantoms were used for the patent blue dye experiments. [THb], [β-carotene], and were affected by , and [β-carotene]/ was 40%. [β-carotene] and [β-carotene]/ were the only parameters not affected by cautery. This work demonstrates the importance of understanding the post-excision kinetics of ex-vivo tissue and the presence of cautery and patent blue dye for breast tumor margin assessment, to accurately interpret data and exploit underling sources of contrast.

Analysis of PTV margin for IMRT and VMAT techniques in prostate cancer using IGRT

International Nuclear Information System (INIS)

Sandrini, E.S.; Silveira, T.B.; Vieira, D.S.; Anjos, L.E.A.; Lopez, J.C.C.; Batista, D.V.S.

2014-01-01

Clinical radiotherapy procedures aim at high precision. However, there are many errors sources that act during treatment preparation and execution that limit its accuracy. The use of imaged-guided radiotherapy (IGRT) increases the agreement between the planned dose and the actual dose deposited in the target, at the same time allows to evaluate the uncertainties related to the setup and a possible reduction in the planning target volume (PTV) margin. Thus the aim of this study was to determine the best PTV margin to be used in radiotherapy treatment of prostate cancer using intensity modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) techniques associated with IGRT. A total of four patients with prostate daily cone beam computed tomography (CBCT) were analyzed. Systematic and random errors were calculated statistically based on the displacements couch for 128 CBCTs. It was found that a symmetric margin of 0.75 cm from clinical treatment volume (CTV) to PTV is sufficient to encompass the uncertainties inherent to the treatment applying IGRT. Besides without that and maintaining the same tumor control probability, a symmetric margin of 1,24 cm would be necessary. This study showed that using daily image verification the setup errors are reduced, which generates a lower PTV margin. (author)

Formulation, computation and improvement of steady state security margins in power systems. Part II: Results

International Nuclear Information System (INIS)

Echavarren, F.M.; Lobato, E.; Rouco, L.; Gomez, T.

2011-01-01

A steady state security margin for a particular operating point can be defined as the distance from this initial point to the secure operating limits of the system. Four of the most used steady state security margins are the power flow feasibility margin, the contingency feasibility margin, the load margin to voltage collapse, and the total transfer capability between system areas. This is the second part of a two part paper. Part I has proposed a novel framework of a general model able to formulate, compute and improve any steady state security margin. In Part II the performance of the general model is validated by solving a variety of practical situations in modern real power systems. Actual examples of the Spanish power system will be used for this purpose. The same computation and improvement algorithms outlined in Part I have been applied for the four security margins considered in the study, outlining the convenience of defining a general framework valid for the four of them. The general model is used here in Part II to compute and improve: (a) the power flow feasibility margin (assessing the influence of the reactive power generation limits in the Spanish power system), (b) the contingency feasibility margin (assessing the influence of transmission and generation capacity in maintaining a correct voltage profile), (c) the load margin to voltage collapse (assessing the location and quantity of loads that must be shed in order to be far away from voltage collapse) and (d) the total transfer capability (assessing the export import pattern of electric power between different areas of the Spanish system). (author)

Formulation, computation and improvement of steady state security margins in power systems. Part II: Results

Energy Technology Data Exchange (ETDEWEB)

Echavarren, F.M.; Lobato, E.; Rouco, L.; Gomez, T. [School of Engineering of Universidad Pontificia Comillas, C/Alberto Aguilera, 23, 28015 Madrid (Spain)

2011-02-15

A steady state security margin for a particular operating point can be defined as the distance from this initial point to the secure operating limits of the system. Four of the most used steady state security margins are the power flow feasibility margin, the contingency feasibility margin, the load margin to voltage collapse, and the total transfer capability between system areas. This is the second part of a two part paper. Part I has proposed a novel framework of a general model able to formulate, compute and improve any steady state security margin. In Part II the performance of the general model is validated by solving a variety of practical situations in modern real power systems. Actual examples of the Spanish power system will be used for this purpose. The same computation and improvement algorithms outlined in Part I have been applied for the four security margins considered in the study, outlining the convenience of defining a general framework valid for the four of them. The general model is used here in Part II to compute and improve: (a) the power flow feasibility margin (assessing the influence of the reactive power generation limits in the Spanish power system), (b) the contingency feasibility margin (assessing the influence of transmission and generation capacity in maintaining a correct voltage profile), (c) the load margin to voltage collapse (assessing the location and quantity of loads that must be shed in order to be far away from voltage collapse) and (d) the total transfer capability (assessing the export import pattern of electric power between different areas of the Spanish system). (author)

Matthew and marginality

Directory of Open Access Journals (Sweden)

Denis C. Duling

1995-12-01

Full Text Available This article explores marginality theory as it was first proposed in  the social sciences, that is related to persons caught between two competing cultures (Park; Stonequist, and, then, as it was developed in sociology as related to the poor (Germani and in anthropology as it was related to involuntary marginality and voluntary marginality (Victor Turner. It then examines a (normative scheme' in antiquity that creates involuntary marginality at the macrosocial level, namely, Lenski's social stratification model in an agrarian society, and indicates how Matthean language might fit with a sample inventory  of socioreligious roles. Next, it examines some (normative schemes' in  antiquity for voluntary margi-nality at the microsocial level, namely, groups, and examines how the Matthean gospel would fit based on indications of factions and leaders. The article ,shows that the author of the Gospel of Matthew has an ideology of (voluntary marginality', but his gospel includes some hope for (involuntary  marginals' in  the  real world, though it is somewhat tempered. It also suggests that the writer of the Gospel is a (marginal man', especially in the sense defined by the early theorists (Park; Stone-quist.

Change of Serum IgG4 in Patients with Ocular Adnexal Marginal Zone B Cell Lymphoma Associated with IgG4-Related Ophthalmic Disease After Treatment.

Science.gov (United States)

Wu, Yuan-Hung; Wang, Lei-Chi; Yen, Sang-Hue; Yu, Wei-Kuang; Kao, Shu-Ching; Kau, Hui-Chuan; Tsai, Chieh-Chih; Liu, Catherine Jui-Ling

2017-09-01

To investigate the change of serum IgG4 concentrations correlated with clinical evolution in patients with ocular adnexal marginal zone B cell lymphoma associated with IgG4-related ophthalmic disease (IgG4-ROD). Three consecutive patients with histopathologically confirmed ocular adnexal marginal zone B cell lymphoma associated with IgG4-ROD were evaluated. Two patients received radiotherapy and 1 patient received steroid therapy. Treatment outcome was evaluated by clinical symptoms, radiologic examination, and change of serum IgG4 level in these patients. All patients had elevated serum IgG4 before treatment (462, 338, and 780 mg/dL respectively.) The 2 patients who received radiotherapy achieved complete remission and the serum IgG4 decreased to 345 and 92 mg/dL, respectively. The patient who underwent systemic steroid achieved partial remission and the serum IgG4 decrease to 161 mg/dL. Our study showed elevated serum IgG4 in all patients with ocular adnexal marginal zone B cell lymphoma associated with IgG4-ROD. In addition, the elevated serum IgG4 may decrease or keep stable after treatment, accompanied by improvement in clinical symptoms and reduction of lesions.

Three-dimensional and topographic relationships between the orbital margins with reference to assessment of eyeball protrusion.

Science.gov (United States)

Shin, Kang-Jae; Lee, Shin-Hyo; Koh, Ki-Seok; Song, Wu-Chul

2017-03-01

This study investigated the topographic relationships among the eyeball and four orbital margins with the aim of identifying the correlation between orbital geometry and eyeball protrusion in Koreans. Three-dimensional (3D) volume rendering of the face was performed using serial computed-tomography images of 141 Koreans, and several landmarks on the bony orbit and the cornea were directly marked on the 3D volumes. The anterior-posterior distances from the apex of the cornea to each orbital margin and between the orbital margins were measured in both eyes. The distances from the apex of the cornea to the superior, medial, inferior, and lateral orbital margins were 5.8, 5.8, 12.0, and 17.9 mm, respectively. Differences between sides were observed in all of the orbital margins, and the distances from the apex of the cornea to the superior and inferior orbital margins were significantly greater in females than in males. The anterior-posterior distance between the superior and inferior orbital margins did not differ significantly between males (6.3 mm) and females (6.2 mm). The data obtained in this study will be useful when developing practical guidelines applicable to forensic facial reconstruction and orbitofacial surgeries.

A new method to assess the gonadal doses in women during radiation treatment

International Nuclear Information System (INIS)

Agrawal, M.S.; Pant, G.C.

1977-01-01

The relative inaccessibility of the ovaries renders direct measurement of the gonadal doses difficult. A relatively simple method is described to tackle this problem - using the upper margin of the public symphysis as a reference point. Measurement of Radiation doses were done in a Masonite human phantom using T.L.D. and a Co-60 teletherapy unit. The accompanying figures document the observations made. The distance between the lower edge of the treatment port and the reference point is denoted by 'd'. First figure relates observed ratios of the radiation doses at the ovary and the reference point to 'd' for various port sizes and the second figure shows the relationship between the area of the port and the dose ratio (ovary: reference-point) for various values of 'd'. The advantage of this documentation is that it serves as a 'Ready Reckoner' to assess the ovarian doses under different treatment situations-once the doses at the reference point is measured

Seismic margin assessment and earthquake experience based methods for WWER-440/213 type NPPs

International Nuclear Information System (INIS)

Masopust, R.

1996-01-01

This report covers the review of the already completed studies, namely, safe shutdown system identification and classification for Bohunice NPP and the comparative study of standards and criteria. It contains a report on currently ongoing studies concerning seismic margin assessment and earthquake experience based methods in application for seismic evaluation and verification of structures and equipment components of the operating WWER-440/213 type NPPs. This is based on experiences obtained from Paks NPP. The work plan for the remaining period of Benchmark CRP and the new proposals are included. These are concerned with seismic evaluation of selected safety related mechanical equipment and pipes of Paks NPP, and the actual seismic issues of the Temelin WWER-1000 type NPP

A strategy for the use of image-guided radiotherapy (IGRT) on linear accelerators and its impact on treatment margins for prostate cancer patients

International Nuclear Information System (INIS)

Nairz, Olaf; Deutschmann, Heinz; Zehentmayr, Franz; Sedlmayer, Felix; Paracelsus Medical University Salzburg; Merz, Florian; Kopp, Peter; Schoeller, Helmut; Wurstbauer, Karl; Kametriser, Gerhard

2008-01-01

In external beam radiotherapy of prostate cancer, the consideration of various systematic error types leads to wide treatment margins compromising normal tissue tolerance. We investigated if systematic set-up errors can be reduced by a set of initial image-guided radiotherapy (IGRT) sessions. 27 patients received daily IGRT resulting in a set of 882 cone-beam computed tomographies (CBCTs). After matching to bony structures, we analyzed the dimensions of remaining systematic errors from zero up to six initial IGRT sessions and aimed at a restriction of daily IGRT for 10% of all patients. For threshold definition, we determined the standard deviations (SD) of the shift corrections and selected patients out of this range for daily image guidance. To calculate total treatment margins, we demanded for a cumulative clinical target volume (CTV) coverage of at least 95% of the specified dose in 90% of all patients. The gain of accuracy was largest during the first three IGRTs. In order to match precision and workload criteria, thresholds for the SD of the corrections of 3.5 mm, 2.0 mm and 4.5 mm in the left-right (L-R), cranial-caudal (C-C), and anterior-posterior (A-P) direction, respectively, were identified. Including all other error types, the total margins added to the CTV amounted to 8.6 mm in L-R, 10.4 mm in C-C, and 14.4 mm in A-P direction. Only initially performed IGRT might be helpful for eliminating gross systematic errors especially after virtual simulation. However, even with daily IGRT performance, a substantial PTV margin reduction is only achievable by matching internal markers instead of bony anatomical structures. (orig.)

Intra-fractional bladder motion and margins in adaptive radiotherapy for urinary bladder cancer

DEFF Research Database (Denmark)

Grønborg, Caroline; Vestergaard, Anne; Høyer, Morten

2015-01-01

and to estimate population-based and patient-specific intra-fractional margins, also relevant for a future re-optimisation strategy. MATERIAL AND METHODS: Nine patients treated in a clinical phase II ART trial of daily plan selection for bladder cancer were included. In the library plans, 5 mm isotropic margins......BACKGROUND: The bladder is a tumour site well suited for adaptive radiotherapy (ART) due to large inter-fractional changes, but it also displays considerable intra-fractional motion. The aim of this study was to assess target coverage with a clinically applied method for plan selection ART...... were added to account for intra-fractional changes. Pre-treatment and weekly repeat magnetic resonance imaging (MRI) series were acquired in which a full three-dimensional (3D) volume was scanned every second min for 10 min (a total of 366 scans in 61 series). Initially, the bladder clinical target...

A gene signature in histologically normal surgical margins is predictive of oral carcinoma recurrence

International Nuclear Information System (INIS)

Reis, Patricia P; Simpson, Colleen; Goldstein, David; Brown, Dale; Gilbert, Ralph; Gullane, Patrick; Irish, Jonathan; Jurisica, Igor; Kamel-Reid, Suzanne; Waldron, Levi; Perez-Ordonez, Bayardo; Pintilie, Melania; Galloni, Natalie Naranjo; Xuan, Yali; Cervigne, Nilva K; Warner, Giles C; Makitie, Antti A

2011-01-01

Oral Squamous Cell Carcinoma (OSCC) is a major cause of cancer death worldwide, which is mainly due to recurrence leading to treatment failure and patient death. Histological status of surgical margins is a currently available assessment for recurrence risk in OSCC; however histological status does not predict recurrence, even in patients with histologically negative margins. Therefore, molecular analysis of histologically normal resection margins and the corresponding OSCC may aid in identifying a gene signature predictive of recurrence. We used a meta-analysis of 199 samples (OSCCs and normal oral tissues) from five public microarray datasets, in addition to our microarray analysis of 96 OSCCs and histologically normal margins from 24 patients, to train a gene signature for recurrence. Validation was performed by quantitative real-time PCR using 136 samples from an independent cohort of 30 patients. We identified 138 significantly over-expressed genes (> 2-fold, false discovery rate of 0.01) in OSCC. By penalized likelihood Cox regression, we identified a 4-gene signature with prognostic value for recurrence in our training set. This signature comprised the invasion-related genes MMP1, COL4A1, P4HA2, and THBS2. Over-expression of this 4-gene signature in histologically normal margins was associated with recurrence in our training cohort (p = 0.0003, logrank test) and in our independent validation cohort (p = 0.04, HR = 6.8, logrank test). Gene expression alterations occur in histologically normal margins in OSCC. Over-expression of the 4-gene signature in histologically normal surgical margins was validated and highly predictive of recurrence in an independent patient cohort. Our findings may be applied to develop a molecular test, which would be clinically useful to help predict which patients are at a higher risk of local recurrence

Role of specimen US for predicting resection margin status in breast conserving therapy.

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Moschetta, M; Telegrafo, M; Introna, T; Coi, L; Rella, L; Ranieri, V; Cirili, A; Stabile Ianora, A A; Angelelli, G

2015-01-01

To assess the diagnostic accuracy of specimen ultrasound (US) for predicting resection margin status in women undergoing breast conserving therapy for US-detected cancer, having the histological findings as the reference standard. A total of 132 consecutive patients (age range, 34-87 years; mean, 51 years) underwent breast-conserving surgery for US-detected invasive breast cancer. All surgical specimens underwent US examination. The presence of lesion within the specimen and its distance from the specimen margins were assessed considering a threshold distance between the lesion and specimen margins of 10 mm. US findings were then compared with the pathological ones and specimen US. Sensitivity, specificity, diagnostic accuracy, positive (PPV) and negative predictive values (NPV) for predicting histological margin status were evaluated, having the histological findings as the reference standard. The histological examination detected invasive ductal carcinoma in 96/132 (73%) cases, invasive lobular carcinoma in 32/132 (24%), mucinous carcinoma in 4/132 (3%). The pathological margin analysis revealed 96/132 (73%) negative margins and 36 (27%) close/positive margins. US examination detected all 132 breast lesions within the surgical specimens. 110 (83%) negative margins and 22 (17%) positive margins were found on US. Sensitivity, specificity, diagnostic accuracy, PPV and NPV of 44%, 94%, 80%, 73% and 82%, respectively, were found for specimen US. Specimen US represents a time and cost saving imaging tool for evaluating the presence of US detected-breast lesion within surgical specimen and for predicting the histological margin status.

Dual in vivo Photoacoustic and Fluorescence Imaging of HER2 Expression in Breast Tumors for Diagnosis, Margin Assessment, and Surgical Guidance

Directory of Open Access Journals (Sweden)

Azusa Maeda

2015-01-01

Full Text Available Biomarker-specific imaging probes offer ways to improve molecular diagnosis, intraoperative margin assessment, and tumor resection. Fluorescence and photoacoustic imaging probes are of particular interest for clinical applications because the combination enables deeper tissue penetration for tumor detection while maintaining imaging sensitivity compared to a single optical imaging modality. Here we describe the development of a human epidermal growth factor receptor 2 (HER2-targeting imaging probe to visualize differential levels of HER2 expression in a breast cancer model. Specifically, we labeled trastuzumab with Black Hole Quencher 3 (BHQ3 and fluorescein for photoacoustic and fluorescence imaging of HER2 overexpression, respectively. The dual-labeled trastuzumab was tested for its ability to detect HER2 overexpression in vitro and in vivo. We demonstrated an over twofold increase in the signal intensity for HER2-overexpressing tumors in vivo, compared to low–HER2-expressing tumors, using photoacoustic imaging. Furthermore, we demonstrated the feasibility of detecting tumors and positive surgical margins by fluorescence imaging. These results suggest that multimodal HER2-specific imaging of breast cancer using the BHQ3-fluorescein trastuzumab enables molecular-level detection and surgical margin assessment of breast tumors in vivo. This technique may have future clinical impact for primary lesion detection, as well as intraoperative molecular-level surgical guidance in breast cancer.

Perforated marginal ulcers after laparoscopic gastric bypass.

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Felix, Edward L; Kettelle, John; Mobley, Elijah; Swartz, Daniel

2008-10-01

Perforated marginal ulcer (PMU) after laparoscopic Roux-en-Y gastric bypass (LRYGB) is a serious complication, but its incidence and etiology have rarely been investigated. Therefore, a retrospective review of all patients undergoing LRYGB at the authors' center was conducted to determine the incidence of PMU and whether any causative factors were present. A prospectively kept database of all patients at the authors' bariatric center was retrospectively reviewed. The complete records of patients with a PMU were examined individually for accuracy and analyzed for treatment, outcome, and possible underlying causes of the marginal perforation. Between April 1999 and August 2007, 1% of the patients (35/3,430) undergoing laparoscopic gastric bypass experienced one or more perforated marginal ulcers 3 to 70 months (median, 18 months) after LRYGB. The patients with and without perforation were not significantly different in terms of mean age (37 vs 41 years), weight (286 vs 287 lb), body mass index (BMI) (46 vs 47), or female gender (89% vs 83%). Of the patients with perforations, 2 (6%) were taking steroids, 10 (29%) were receiving nonsteroidal antiinflammatory drugs (NSAIDs) at the time of the perforation, 18 (51%) were actively smoking, and 6 of the smokers also were taking NSAIDs. Eleven of the patients (31%) who perforated did not have at least one of these possible risk factors, but 4 (36%) of the 11 patients in this group had been treated after bypass for a marginal ulcer. Only 7 (20%) of the 35 patients who had laparoscopic bypass, or 7 (0.2%) in the entire group of 3,430 patients, perforated without any warning. There were no deaths, but three patients reperforated. The incidence of a marginal ulcer perforating after LRYGB was significant (>1%) and appeared to be related to smoking or the use of NSAIDs or steroids. Because only 0.2% of all patients acutely perforated without some risk factor or warning, long-term ulcer prophylaxis or treatment may be necessary

On the Margins of Pharmaceutical Citizenship: Not Taking HIV Medication in the "Treatment Revolution" Era.

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Persson, Asha; Newman, Christy E; Mao, Limin; de Wit, John

2016-09-01

With the expanding pharmaceuticalization of public health, anthropologists have begun to examine how biomedicine's promissory discourses of normalization and demarginalization give rise to new practices of and criteria for citizenship. Much of this work focuses on the biomedicine-citizenship nexus in less-developed, resource-poor contexts. But how do we understand this relationship in resource-rich settings where medicines are readily available, often affordable, and a highly commonplace response to illness? In particular, what does it mean to not use pharmaceuticals for a treatable infectious disease in this context? We are interested in these questions in relation to the recent push for early and universal treatment for HIV infection in Australia for the twin purposes of individual and community health. Drawing on Ecks's concept of pharmaceutical citizenship, we examine the implications for citizenship among people with HIV who refuse or delay recommended medication. We find that moral and normative expectations emerging in the new HIV "treatment revolution" have the capacity to both demarginalize and marginalize people with HIV. © 2016 by the American Anthropological Association.

Marginal and happy? The need for uniqueness predicts the adjustment of marginal immigrants.

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Debrosse, Régine; de la Sablonnière, Roxane; Rossignac-Milon, Maya

2015-12-01

Marginalization is often presented as the strategy associated with the worst adjustment for immigrants. This study identifies a critical variable that buffers marginal immigrants from the negative effects of marginalization on adjustment: The need for uniqueness. In three studies, we surveyed immigrants recruited on university campuses (n = 119, n = 116) and in the field (n = 61). Among marginal immigrants, a higher need for uniqueness predicted higher self-esteem (Study 1), affect (Study 2), and life satisfaction (Study 3), and marginally higher happiness (Study 2) and self-esteem (Study 3). No relationship between the need for uniqueness and adjustment was found among non-marginal immigrants. The adaptive value of the need for uniqueness for marginal immigrants is discussed. © 2015 The British Psychological Society.

SU-F-BRD-07: Empirical Derivation of Site-Specific Margin Formulas

International Nuclear Information System (INIS)

Conroy, L; Smith, W; Quirk, S

2014-01-01

Purpose: To empirically derive margin formulas from existing clinical radiotherapy plans accounting for respiratory motion and setup uncertainties. Methods: We simulated realistic treatment scenarios, including respiratory motion and setup errors. Individual probability density functions (PDF) from respiratory data were used to simulate respiratory motion. Random (σ) and systematic (Σ) setup errors were modeled as Gaussian distributions. One-dimensional dose profiles were extracted from existing radiotherapy plans and convolved with respiratory PDFs and random error distributions to produce blurred dose profiles. Each blurred dose profile was then shifted 1000 times by randomly sampling the simulated systematic error distribution. Margins were determined from the distance between the simulated treatment and the original 95% isodose level. An equation was fit for each (σ, Σ) combination to derive margin formulas for 90% of the population receiving 95% dose. This methodology can be applied to different tumor sites. Here, dose profiles were extracted from partial breast 3DCRT plans in the anterior-posterior (AP) and superior-inferior (SI) directions. Respiratory motion data was from healthy volunteers, and a clinically relevant range of random and systematic setup errors (standard deviations 1 – 4 mm) was determined from the literature. Results: The PBI margin formulas in the AP and SI directions for 95% dose coverage for 90% of the population were very similar: M= 0.68σ + 1.54Σ and M= 0.72σ + 1.50Σ, respectively. Systematic setup errors had the largest influence on required margin size, whereas realistic respiratory amplitude had minimal impact. The derived formulas resulted in a smaller systematic component than commonly-used theoretical margin recipes. Conclusion: We have demonstrated a method to derive empirical margin formulas from existing patient radiotherapy plans, incorporating realistic respiratory motion and appropriate ranges of random and

Hormesis: from marginalization to mainstream A case for hormesis as the default dose-response model in risk assessment

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Calabrese, Edward J.

2004-01-01

The paper provides an account of how the hormetic dose response has emerged in recent years as a serious dose-response model in toxicology and risk assessment after decades of extreme marginalization. In addition to providing the toxicological basis of this dose-response revival, the paper reexamines the concept of a default dose model in toxicology and risk assessment and makes the argument that the hormetic model satisfies criteria (e.g., generalizability, frequency, application to risk assessment endpoints, false positive/negative potential, requirements for hazard assessment, reliability of estimating risks, capacity for validation of risk estimates, public health implications of risk estimates) for such a default model better than its chief competitors, the threshold and linear at low dose models. The selection of the hormetic model as the default model in risk assessment for noncarcinogens and specifically for carcinogens would have a profound impact on the practice of risk assessment and its societal implications

Enhancing the diversity of breeding invertebrates within field margins of intensively managed grassland: Effects of alternative management practices.

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Fritch, Rochelle A; Sheridan, Helen; Finn, John A; McCormack, Stephen; Ó hUallacháin, Daire

2017-11-01

Severe declines in biodiversity have been well documented for many taxonomic groups due to intensification of agricultural practices. Establishment and appropriate management of arable field margins can improve the diversity and abundance of invertebrate groups; however, there is much less research on field margins within grassland systems. Three grassland field margin treatments (fencing off the existing vegetation "fenced"; fencing with rotavation and natural regeneration "rotavated" and; fencing with rotavation and seeding "seeded") were compared to a grazed control in the adjacent intensively managed pasture. Invertebrates were sampled using emergence traps to investigate species breeding and overwintering within the margins. Using a manipulation experiment, we tested whether the removal of grazing pressure and nutrient inputs would increase the abundance and richness of breeding invertebrates within grassland field margins. We also tested whether field margin establishment treatments, with their different vegetation communities, would change the abundance and richness of breeding invertebrates in the field margins. Exclusion of grazing and nutrient inputs led to increased abundance and richness in nearly all invertebrate groups that we sampled. However, there were more complex effects of field margin establishment treatment on the abundance and richness of invertebrate taxa. Each of the three establishment treatments supported a distinct invertebrate community. The removal of grazing from grassland field margins provided a greater range of overwintering/breeding habitat for invertebrates. We demonstrate the capacity of field margin establishment to increase the abundance and richness in nearly all invertebrate groups in study plots that were located on previously more depauperate areas of intensively managed grassland. These results from grassland field margins provide evidence to support practical actions that can inform Greening (Pillar 1) and agri

Risk Factors Associated With Circumferential Resection Margin Positivity in Rectal Cancer: A Binational Registry Study.

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Warrier, Satish K; Kong, Joseph Cherng; Guerra, Glen R; Chittleborough, Timothy J; Naik, Arun; Ramsay, Robert G; Lynch, A Craig; Heriot, Alexander G

2018-04-01

Rectal cancer outcomes have improved with the adoption of a multidisciplinary model of care. However, there is a spectrum of quality when viewed from a national perspective, as highlighted by the Consortium for Optimizing the Treatment of Rectal Cancer data on rectal cancer care in the United States. The aim of this study was to assess and identify predictors of circumferential resection margin involvement for rectal cancer across Australasia. A retrospective study from a prospectively maintained binational colorectal cancer database was interrogated. This study is based on a binational colorectal cancer audit database. Clinical information on all consecutive resected rectal cancer cases recorded in the registry from 2007 to 2016 was retrieved, collated, and analyzed. The primary outcome measure was positive circumferential resection margin, measured as a resection margin ≤1 mm. A total of 3367 patients were included, with 261 (7.5%) having a positive circumferential resection margin. After adjusting for hospital and surgeon volume, hierarchical logistic regression analysis identified a 6-variable model encompassing the independent predictors, including urgent operation, abdominoperineal resection, open technique, low rectal cancer, T3 to T4, and N1 to N2. The accuracy of the model was 92.3%, with an receiver operating characteristic of 0.783 (p risk associated with circumferential resection margin positivity ranged from risk factors) to 43% (6 risk factors). This study was limited by the lack of recorded long-term outcomes associated with circumferential resection margin positivity. The rate of circumferential resection margin involvement in patients undergoing rectal cancer resection in Australasia is low and is influenced by a number of factors. Risk stratification of outcome is important with the increasing demand for publicly accessible quality data. See Video Abstract at http://links.lww.com/DCR/A512.

Treatment simulations with a statistical deformable motion model to evaluate margins for multiple targets in radiotherapy for high-risk prostate cancer

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Thörnqvist, Sara; Hysing, Liv B.; Zolnay, Andras G.; Söhn, Matthias; Hoogeman, Mischa S.; Muren, Ludvig P.; Bentzen, Lise; Heijmen, Ben J.M.

2013-01-01

Background and purpose: Deformation and correlated target motion remain challenges for margin recipes in radiotherapy (RT). This study presents a statistical deformable motion model for multiple targets and applies it to margin evaluations for locally advanced prostate cancer i.e. RT of the prostate (CTV-p), seminal vesicles (CTV-sv) and pelvic lymph nodes (CTV-ln). Material and methods: The 19 patients included in this study, all had 7–10 repeat CT-scans available that were rigidly aligned with the planning CT-scan using intra-prostatic implanted markers, followed by deformable registrations. The displacement vectors from the deformable registrations were used to create patient-specific statistical motion models. The models were applied in treatment simulations to determine probabilities for adequate target coverage, e.g. by establishing distributions of the accumulated dose to 99% of the target volumes (D 99 ) for various CTV–PTV expansions in the planning-CTs. Results: The method allowed for estimation of the expected accumulated dose and its variance of different DVH parameters for each patient. Simulations of inter-fractional motion resulted in 7, 10, and 18 patients with an average D 99 >95% of the prescribed dose for CTV-p expansions of 3 mm, 4 mm and 5 mm, respectively. For CTV-sv and CTV-ln, expansions of 3 mm, 5 mm and 7 mm resulted in 1, 11 and 15 vs. 8, 18 and 18 patients respectively with an average D 99 >95% of the prescription. Conclusions: Treatment simulations of target motion revealed large individual differences in accumulated dose mainly for CTV-sv, demanding the largest margins whereas those required for CTV-p and CTV-ln were comparable

Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins

DEFF Research Database (Denmark)

Muren, Ludvig; Redpath, Anthony Thomas; Lord, Hannah

2007-01-01

: The correlation between the relative bladder volume (RBV, defined as repeat scan volume/planning scan volume) and the margins required to account for internal motion was first studied using a series of 20 bladder cancer patients with weekly repeat CT scanning during treatment. Both conformal RT (CRT) and IGRT......BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS...... these patients were given fluid intake restrictions on alternating weeks during treatment. RESULTS: IGRT gave the strongest correlation between the RBV and margin size (R(2)=0.75; p10mm were required in only 1% of the situations when the RBV1, whereas isotropic margins >10...

An Investigation of Rotorcraft Stability-Phase Margin Requirements in Hover

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Blanken, Chris L.; Lusardi, Jeff A.; Ivler, Christina M.; Tischler, Mark B.; Hoefinger, Marc T.; Decker, William A.; Malpica, Carlos A.; Berger, Tom; Tucker, George E.

2009-01-01

A cooperative study was performed to investigate the handling quality effects from reduced flight control system stability margins, and the trade-offs with higher disturbance rejection bandwidth (DRB). The piloted simulation study, perform on the NASA-Ames Vertical Motion Simulator, included three classes of rotorcraft in four configurations: a utility-class helicopter; a medium-lift helicopter evaluated with and without an external slung load; and a large (heavy-lift) civil tiltrotor aircraft. This large aircraft also allowed an initial assessment of ADS-33 handling quality requirements for an aircraft of this size. Ten experimental test pilots representing the U.S. Army, Marine Corps, NASA, rotorcraft industry, and the German Aerospace Center (DLR), evaluated the four aircraft configurations, for a range of flight control stability-margins and turbulence levels, while primarily performing the ADS-33 Hover and Lateral Reposition MTEs. Pilot comments and aircraft-task performance data were analyzed. The preliminary stability margin results suggest higher DRB and less phase margin cases are preferred as the aircraft increases in size. Extra care will need to be taken to assess the influence of variability when nominal flight control gains start with reduced margins. Phase margins as low as 20-23 degrees resulted in low disturbance-response damping ratios, objectionable oscillations, PIO tendencies, and a perception of an incipient handling qualities cliff. Pilot comments on the disturbance response of the aircraft correlated well to the DRB guidelines provided in the ADS-33 Test Guide. The A D-3S3 mid-term response-to-control damping ratio metrics can be measured and applied to the disturbance-response damping ratio. An initial assessment of LCTR yaw bandwidth shows the current Level 1 boundary needs to be relaxed to help account for a large pilot off-set from the c.g. Future efforts should continue to investigate the applicability/refinement of the current ADS-33

Energy system analysis of marginal electricity supply in consequential LCA

DEFF Research Database (Denmark)

Lund, Henrik; Mathiesen, Brian Vad; Christensen, Per

2010-01-01

Background, aim and scope This paper discusses the identification of the environmental consequences of marginal electricity supplies in consequential life cycle assessments (LCA). According to the methodology, environmental characteristics can be examined by identifying affected activities, i...... in capacity but can be characterised as a complex set of affected electricity and heat supply technologies. A long-term YAM technology is identified for the Danish BAU2030 system in the case of three different long-term marginal changes in capacity, namely coal, natural gas or wind power. Discussion Four...... of four different situations are provided. We suggest that the technology mix with the installation of natural gas or coal power plant is applied as the marginal capacity. Conclusions The environmental consequences of marginal changes in electricity supply cannot always be represented solely by long...

Consideration of margins for hypo fractionated radiotherapy

International Nuclear Information System (INIS)

Herschtal, A.; Foroudi, F.; Kron, T.

2010-01-01

Full text: Geographical misses of the tumour are of concern in radiotherapy and are typically accommodated by introducing margins around the target. However, there is a trade-off between ensuring the target receives sufficient dose and minimising the dose to surrounding normal structures. Several methods of determining margin width have been developed with the most commonly used one proposed by M. VanHerk (VanHerk UROBP 52: 1407, 2002). VanHerk's model sets margins to achieve 95% of dose coverage for the target in 90% of patients. However, this model was derived assuming an infinite number of fractions. The aim of the present work is to estimate the modifications necessary to the model if a finite number of fractions are given. Software simulations were used to determine the true probability of a patient achieving 95% target coverage if different fraction numbers are used for a given margin width. Model parameters were informed by a large data set recently acquired at our institution using daily image guidance for prostate cancer patients with implanted fiducial markers. Assuming a 3 mm penumbral width it was found that using the VanHerk model only 74 or 54% of patients receive 95% of the prescription dose if 20 or 6 fractions are given, respectively. The steep dose gradients afforded by IMRT are likely to make consideration of the effects of hypofractionation more important. It is necessary to increase the margins around the target to ensure adequate tumour coverage if hypofractionated radiotherapy is to be used for cancer treatment. (author)

The Role of Seminal Vesicle Motion in Target Margin Assessment for Online Image-Guided Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Liang Jian; Wu Qiuwen; Yan Di

2009-01-01

Purpose: For patients with intermediate- and high-risk prostate cancer, the seminal vesicles (SVs) are included in the clinical target volume (CTV). The purposes of this study are to investigate interfraction motion characteristics of the SVs and determine proper margins for online computed tomography image guidance. Methods and Materials: Twenty-four patients, each with 16 daily helical computed tomography scans, were included in this study. A binary image mask was used for image registration to determine daily organ motion. Two online image-guided radiotherapy strategies (prostate only and prostate + SVs) were simulated in a hypofractionated scheme. Three margin designs were studied for both three-dimensional conformal radiotherapy and intensity-modulated radiotherapy (IMRT). In prostate-only guidance, Margin A was uniformly applied to the whole CTV, and Margin B was applied to the SVs with a fixed 3-mm prostate margin. In prostate plus SV guidance, Margin C was uniformly applied to the CTV. The minimum margins were sought to satisfy the criterion that minimum cumulative CTV dose be more than those of the planning target volume in the plan for greater than 95% of patients. Results: The prostate and SVs move significantly more in the anterior-posterior and superior-inferior than right-left directions. The anterior-posterior motion of the prostate and SVs correlated (R 2 = 0.7). The SVs move significantly more than the prostate. The minimum margins found were 2.5 mm for three-dimensional conformal radiotherapy and 4.5, 4.5, and 3.0 mm for Margins A, B, and C for IMRT, respectively. Margins for IMRT were larger, but the irradiated volume and doses to critical structures were smaller. Minimum margins of 4.5 mm to the SVs and 3 mm to the prostate are recommended for IMRT with prostate-only guidance. Conclusions: The SVs move independently from the prostate gland, and additional margins are necessary for image-guided radiotherapy

Risk-Informed Safety Margin Characterization (RISMC): Integrated Treatment of Aleatory and Epistemic Uncertainty in Safety Analysis

International Nuclear Information System (INIS)

Youngblood, R.W.

2010-01-01

The concept of 'margin' has a long history in nuclear licensing and in the codification of good engineering practices. However, some traditional applications of 'margin' have been carried out for surrogate scenarios (such as design basis scenarios), without regard to the actual frequencies of those scenarios, and have been carried out with in a systematically conservative fashion. This means that the effectiveness of the application of the margin concept is determined in part by the original choice of surrogates, and is limited in any case by the degree of conservatism imposed on the evaluation. In the RISMC project, which is part of the Department of Energy's 'Light Water Reactor Sustainability Program' (LWRSP), we are developing a risk-informed characterization of safety margin. Beginning with the traditional discussion of 'margin' in terms of a 'load' (a physical challenge to system or component function) and a 'capacity' (the capability of that system or component to accommodate the challenge), we are developing the capability to characterize probabilistic load and capacity spectra, reflecting both aleatory and epistemic uncertainty in system response. For example, the probabilistic load spectrum will reflect the frequency of challenges of a particular severity. Such a characterization is required if decision-making is to be informed optimally. However, in order to enable the quantification of probabilistic load spectra, existing analysis capability needs to be extended. Accordingly, the INL is working on a next-generation safety analysis capability whose design will allow for much more efficient parameter uncertainty analysis, and will enable a much better integration of reliability-related and phenomenology-related aspects of margin.

Medium-term marginal costs in competitive generation power markets

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Reneses, J.; Centeno, E.; Barquin, J.

2004-01-01

The meaning and significance of medium-term marginal costs for a generation company in a competitive power market in analysed. A methodology to compute and decompose medium-term generation marginal costs in a competitive environment is proposed. The methodology is based on a market equilibrium model. The aim is to provide a useful tool for generation companies so that they can manage their resources in an optimal way, helping them with their operation, decision-making processes, asset valuations or contract assessments. (author)

Pattern of Failure After Limited Margin Radiotherapy and Temozolomide for Glioblastoma

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McDonald, Mark W.; Shu, Hui-Kuo G.; Curran, Walter J.; Crocker, Ian R.

2011-01-01

Purpose: To evaluate the pattern of failure after limited margin radiotherapy for glioblastoma. Methods and Materials: We analyzed 62 consecutive patients with newly diagnosed glioblastoma treated between 2006 and 2008 with standard fractionation to a total dose of 60Gy with concurrent temozolomide (97%) or arsenic trioxide (3%). The initial clinical target volume included postoperative T2 abnormality with a median margin of 0.7cm. The boost clinical target volume included residual T1-enhancing tumor and resection cavity with a median margin of 0.5cm. Planning target volumes added a 0.3- or 0.5-cm margin to clinical target volumes. The total boost planning target volume (PTV boost ) margin was 1cm or less in 92% of patients. The volume of recurrent tumor (new T1 enhancement) was categorized by the percent within the 60-Gy isodose line as central (>95%), infield (81-95%), marginal (20-80%), or distant ( boost with a 2.5-cm margin were created for each patient. Results: With a median follow-up of 12 months, radiographic tumor progression developed in 43 of 62 patients. Imaging was available for analysis in 41: 38 (93%) had central or infield failure, 2 (5%) had marginal failure, and 1 (2%) had distant failure relative to the 60-Gy isodose line. The treated PTV boost (median, 140cm 3 ) was, on average, 70% less than the PTV boost with a 2.5-cm margin (median, 477cm 3 ) (p boost margin of 1cm or less did not appear to increase the risk of marginal and/or distant tumor failures compared with other published series. With careful radiation planning and delivery, it appears that treatment margins for glioblastoma can be reduced.

Buccal mucosa carcinoma: surgical margin less than 3 mm, not 5 mm, predicts locoregional recurrence

Directory of Open Access Journals (Sweden)

Chiou Wen-Yen

2010-09-01

Full Text Available Abstract Background Most treatment failure of buccal mucosal cancer post surgery is locoregional recurrence. We tried to figure out how close the surgical margin being unsafe and needed further adjuvant treatment. Methods Between August 2000 and June 2008, a total of 110 patients with buccal mucosa carcinoma (25 with stage I, 31 with stage II, 11 with stage III, and 43 with Stage IV classified according to the American Joint Committee on Cancer 6th edition were treated with surgery alone (n = 32, surgery plus postoperative radiotherapy (n = 38 or surgery plus adjuvant concurrent chemoradiotherapy (n = 40. Main outcome measures: The primary endpoint was locoregional disease control. Results The median follow-up time at analysis was 25 months (range, 4-104 months. The 3-year locoregional control rates were significantly different when a 3-mm surgical margin (≤3 versus >3 mm, 71% versus 95%, p = 0.04 but not a 5-mm margin (75% versus 92%, p = 0.22 was used as the cut-off level. We also found a quantitative correlation between surgical margin and locoregional failure (hazard ratio, 2.16; 95% confidence interval, 1.14 - 4.11; p = 0.019. Multivariate analysis identified pN classification and surgical margin as independent factors affecting disease-free survival and locoregional control. Conclusions Narrow surgical margin ≤3 mm, but not 5 mm, is associated with high risk for locoregional recurrence of buccal mucosa carcinoma. More aggressive treatment after surgery is suggested.

Buccal mucosa carcinoma: surgical margin less than 3 mm, not 5 mm, predicts locoregional recurrence

International Nuclear Information System (INIS)

Chiou, Wen-Yen; Hung, Shih-Kai; Lin, Hon-Yi; Hsu, Feng-Chun; Lee, Moon-Sing; Ho, Hsu-Chueh; Su, Yu-Chieh; Lee, Ching-Chih; Hsieh, Chen-Hsi; Wang, Yao-Ching

2010-01-01

Most treatment failure of buccal mucosal cancer post surgery is locoregional recurrence. We tried to figure out how close the surgical margin being unsafe and needed further adjuvant treatment. Between August 2000 and June 2008, a total of 110 patients with buccal mucosa carcinoma (25 with stage I, 31 with stage II, 11 with stage III, and 43 with Stage IV classified according to the American Joint Committee on Cancer 6 th edition) were treated with surgery alone (n = 32), surgery plus postoperative radiotherapy (n = 38) or surgery plus adjuvant concurrent chemoradiotherapy (n = 40). Main outcome measures: The primary endpoint was locoregional disease control. The median follow-up time at analysis was 25 months (range, 4-104 months). The 3-year locoregional control rates were significantly different when a 3-mm surgical margin (≤3 versus >3 mm, 71% versus 95%, p = 0.04) but not a 5-mm margin (75% versus 92%, p = 0.22) was used as the cut-off level. We also found a quantitative correlation between surgical margin and locoregional failure (hazard ratio, 2.16; 95% confidence interval, 1.14 - 4.11; p = 0.019). Multivariate analysis identified pN classification and surgical margin as independent factors affecting disease-free survival and locoregional control. Narrow surgical margin ≤3 mm, but not 5 mm, is associated with high risk for locoregional recurrence of buccal mucosa carcinoma. More aggressive treatment after surgery is suggested

The scenario-based generalization of radiation therapy margins

International Nuclear Information System (INIS)

Fredriksson, Albin; Bokrantz, Rasmus

2016-01-01

We give a scenario-based treatment plan optimization formulation that is equivalent to planning with geometric margins if the scenario doses are calculated using the static dose cloud approximation. If the scenario doses are instead calculated more accurately, then our formulation provides a novel robust planning method that overcomes many of the difficulties associated with previous scenario-based robust planning methods. In particular, our method protects only against uncertainties that can occur in practice, it gives a sharp dose fall-off outside high dose regions, and it avoids underdosage of the target in ‘easy’ scenarios. The method shares the benefits of the previous scenario-based robust planning methods over geometric margins for applications where the static dose cloud approximation is inaccurate, such as irradiation with few fields and irradiation with ion beams. These properties are demonstrated on a suite of phantom cases planned for treatment with scanned proton beams subject to systematic setup uncertainty. (paper)

Biological impact of geometric uncertainties: what margin is needed for intra-hepatic tumors?

International Nuclear Information System (INIS)

Kuo, Hsiang-Chi; Liu, Wen-Shan; Wu, Andrew; Mah, Dennis; Chuang, Keh-Shih; Hong, Linda; Yaparpalvi, Ravi; Guha, Chandan; Kalnicki, Shalom

2010-01-01

To evaluate and compare the biological impact on different proposed margin recipes for the same geometric uncertainties for intra-hepatic tumors with different tumor cell types or clinical stages. Three different margin recipes based on tumor motion were applied to sixteen IMRT plans with a total of twenty two intra-hepatic tumors. One recipe used the full amplitude of motion measured from patients to generate margins. A second used 70% of the full amplitude of motion, while the third had no margin for motion. The biological effects of geometric uncertainty in these three situations were evaluated with Equivalent Uniform Doses (EUD) for various survival fractions at 2 Gy (SF 2 ). There was no significant difference in the biological impact between the full motion margin and the 70% motion margin. Also, there was no significant difference between different tumor cell types. When the margin for motion was eliminated, the difference of the biological impact was significant among different cell types due to geometric uncertainties. Elimination of the motion margin requires dose escalation to compensate for the biological dose reduction due to the geometric misses during treatment. Both patient-based margins of full motion and of 70% motion are sufficient to prevent serious dosimetric error. Clinical implementation of margin reduction should consider the tumor sensitivity to radiation

Importance of margin width in breast-conserving treatment of early breast cancer

DEFF Research Database (Denmark)

Bodilsen, Anne; Bjerre, Karsten; Offersen, Birgitte V

2016-01-01

in the adjusted analysis of margin width (>0 to P 4 positive lymph nodes (P = 0.008) and re......-excision (P = 0.003). A reduced risk of IBTR was observed with chemotherapy (P P = 0.023) and ER positivity (P 

"We call ourselves marginalized"

DEFF Research Database (Denmark)

Jørgensen, Nanna Jordt

2014-01-01

of the people we refer to as marginalized. In this paper, I discuss how young secondary school graduates from a pastoralist community in Kenya use and negotiate indigeneity, marginal identity, and experiences of marginalization in social navigations aimed at broadening their current and future opportunities. I...

Using Logistic Approximations of Marginal Trace Lines to Develop Short Assessments

Science.gov (United States)

Stucky, Brian D.; Thissen, David; Edelen, Maria Orlando

2013-01-01

Test developers often need to create unidimensional scales from multidimensional data. For item analysis, "marginal trace lines" capture the relation with the general dimension while accounting for nuisance dimensions and may prove to be a useful technique for creating short-form tests. This article describes the computations needed to obtain…

End points and assessments in esthetic dental treatment.

Science.gov (United States)

Ishida, Yuichi; Fujimoto, Keiko; Higaki, Nobuaki; Goto, Takaharu; Ichikawa, Tetsuo

2015-10-01

There are two key considerations for successful esthetic dental treatments. This article systematically describes the two key considerations: the end points of esthetic dental treatments and assessments of esthetic outcomes, which are also important for acquiring clinical skill in esthetic dental treatments. The end point and assessment of esthetic dental treatment were discussed through literature reviews and clinical practices. Before designing a treatment plan, the end point of dental treatment should be established. The section entitled "End point of esthetic dental treatment" discusses treatments for maxillary anterior teeth and the restoration of facial profile with prostheses. The process of assessing treatment outcomes entitled "Assessments of esthetic dental treatment" discusses objective and subjective evaluation methods. Practitioners should reach an agreement regarding desired end points with patients through medical interviews, and continuing improvements and developments of esthetic assessments are required to raise the therapeutic level of esthetic dental treatments. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Continental transform margins : state of art and future milestones

Science.gov (United States)

Basile, Christophe

2010-05-01

to be emphasized. There is not only one type of transform margins, but as for divergent margins huge changes from one margin to another in both structure and evolution. Multiple types have to be evidenced together with the various parameters that should control the variability. As for divergent margins, special attention should be paid to conjugated transform margins as a tool to assess symmetrical / asymmetrical processes in the oceanic opening. Attention should also be focused on the three-dimensional structure of the intersections between transform and divergent margins, such as the one where the giant oil field Jubilee was recently discovered. There is almost no 3D data available in these area, and their structures still have to be described. An other key point to develop is the mechanical behavior of the lithosphere in and in the vicinity of transform margins. The classical behaviors (isostasy, elastic flexure) have be tested extensively. The localization of the deformation by the transform fault, and the coupling of continental and oceanic lithosphere across the transform fault have to be adressed to understand the evolution of these margins. Again as for divergent margins, new concepts are needed to explain the variations in the post-rift and post-transform subsidence, that can not always be explained by classical subsidence models. But the most remarkable advance in our understanding of transform margins may be related to the study of interactions between the lithosphere and adjacent envelops : deep interactions with the mantle, as underplating, tectonic erosion, or possible lateral crustal flow ; surficial interactions between structural evolution, erosion and sedimentation processes in transform margins may affect the topography and bathymetry, thus the oceanic circulation with possible effects on regional and global climate.

Marginal Matter

Science.gov (United States)

van Hecke, Martin

2013-03-01

All around us, things are falling apart. The foam on our cappuccinos appears solid, but gentle stirring irreversibly changes its shape. Skin, a biological fiber network, is firm when you pinch it, but soft under light touch. Sand mimics a solid when we walk on the beach but a liquid when we pour it out of our shoes. Crucially, a marginal point separates the rigid or jammed state from the mechanical vacuum (freely flowing) state - at their marginal points, soft materials are neither solid nor liquid. Here I will show how the marginal point gives birth to a third sector of soft matter physics: intrinsically nonlinear mechanics. I will illustrate this with shock waves in weakly compressed granular media, the nonlinear rheology of foams, and the nonlinear mechanics of weakly connected elastic networks.

Marginalization of the Youth

DEFF Research Database (Denmark)

Jensen, Niels Rosendal

2009-01-01

The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization.......The article is based on a key note speach in Bielefeld on the subject "welfare state and marginalized youth", focusing upon the high ambition of expanding schooling in Denmark from 9 to 12 years. The unintended effect may be a new kind of marginalization....

Convexity and Marginal Vectors

NARCIS (Netherlands)

van Velzen, S.; Hamers, H.J.M.; Norde, H.W.

2002-01-01

In this paper we construct sets of marginal vectors of a TU game with the property that if the marginal vectors from these sets are core elements, then the game is convex.This approach leads to new upperbounds on the number of marginal vectors needed to characterize convexity.An other result is that

Sustainability assessment of advanced wastewater treatment technologies

DEFF Research Database (Denmark)

Høibye, Linda; Clauson-Kaas, Jes; Wenzel, Henrik

2007-01-01

, which includes technical, economic and environmental aspects. The technical and economic assessment is performed on 5 advanced treatment technologies: sand filtration, ozone treatment, UV exclusively for disinfection of pathogenic microorganisms, Membrane Bioreactor (MBR), and UV in combination......As a consequence of the EU Water Framwork Directive, more focus is now on discharges of hazardous substances from wastewater treatment plants and sewers. Thus, many municipalities in Denmark may have to adopt to future advenced treatment technologies. This paper describes a holistic assessment...... with advanced oxidation. The technical assessment is based on 12 hazardous substances comprising heavy metals, organic pollutants, endocrine disruptors as well as pathogenic microorganisms. The environmental assessment is performed by life cycle assessment (LCA) comprising 9 of the specific hazardous substances...

Sustainability assessment of advanced wastewater treatment technologies

DEFF Research Database (Denmark)

Høibye, Linda; Clauson-Kaas, Jes; Wenzel, Henrik

2008-01-01

, which includes technical, economical and environmental aspects. The technical and economical assessment is performed on 5 advanced treatment technologies: sand filtration, ozone treatment, UV exclusively for disinfection of pathogenic microorganisms, membrane bioreactor (MBR) and UV in combination......As a consequence of the EU Water Framework Directive more focus is now on discharges of hazardous substances from wastewater treatment plants and sewers. Thus, many municipalities in Denmark may have to adopt to future advanced treatment technologies. This paper describes a holistic assessment...... with advanced oxidation. The technical assessment is based on 12 hazardous substances comprising heavy metals, organic pollutants, endocrine disruptors as well as pathogenic microorganisms. The environmental assessment is performed by life cycle assessment (LCA) comprising 9 of the specific hazardous substances...

Contributions to knowledge of the continental margin of Uruguay. Uruguayan continental margin: Physiographic and seismic analysis

International Nuclear Information System (INIS)

Preciozzi, F

2014-01-01

This work is about the kind of continental margins such as a )Atlantic type passive margins which can be hard or soft b) An active or Pacific margins that because of the very frequent earthquakes develop a morphology dominated by tectonic processes. The Uruguayan continental margin belongs to a soft Atlantic margin

Fixing soft margins

NARCIS (Netherlands)

P. Kofman (Paul); A. Vaal, de (Albert); C.G. de Vries (Casper)

1993-01-01

textabstractNon-parametric tolerance limits are employed to calculate soft margins such as advocated in Williamson's target zone proposal. In particular, the tradeoff between softness and zone width is quantified. This may be helpful in choosing appropriate margins. Furthermore, it offers

SOCIAL MARGINALIZATION AND HEALTH

Directory of Open Access Journals (Sweden)

Marjana Bogdanović

2007-04-01

Full Text Available The 20th century was characterized by special improvement in health. The aim of WHO’s policy EQUITY IN HEALTH is to enable equal accessibility and equal high quality of health care for all citizens. More or less some social groups have stayed out of many social systems even out of health care system in the condition of social marginalization. Phenomenon of social marginalization is characterized by dynamics. Marginalized persons have lack of control over their life and available resources. Social marginalization stands for a stroke on health and makes the health status worse. Low socio-economic level dramatically influences people’s health status, therefore, poverty and illness work together. Characteristic marginalized groups are: Roma people, people with AIDS, prisoners, persons with development disorders, persons with mental health disorders, refugees, homosexual people, delinquents, prostitutes, drug consumers, homeless…There is a mutual responsibility of community and marginalized individuals in trying to resolve the problem. Health and other problems could be solved only by multisector approach to well-designed programs.

Pickering seismic safety margin

International Nuclear Information System (INIS)

Ghobarah, A.; Heidebrecht, A.C.; Tso, W.K.

1992-06-01

A study was conducted to recommend a methodology for the seismic safety margin review of existing Canadian CANDU nuclear generating stations such as Pickering A. The purpose of the seismic safety margin review is to determine whether the nuclear plant has sufficient seismic safety margin over its design basis to assure plant safety. In this review process, it is possible to identify the weak links which might limit the seismic performance of critical structures, systems and components. The proposed methodology is a modification the EPRI (Electric Power Research Institute) approach. The methodology includes: the characterization of the site margin earthquake, the definition of the performance criteria for the elements of a success path, and the determination of the seismic withstand capacity. It is proposed that the margin earthquake be established on the basis of using historical records and the regional seismo-tectonic and site specific evaluations. The ability of the components and systems to withstand the margin earthquake is determined by database comparisons, inspection, analysis or testing. An implementation plan for the application of the methodology to the Pickering A NGS is prepared

Application of the Integrated Safety Assessment methodology to safety margins. Dynamic Event Trees, Damage Domains and Risk Assessment

International Nuclear Information System (INIS)

Ibánez, L.; Hortal, J.; Queral, C.; Gómez-Magán, J.; Sánchez-Perea, M.; Fernández, I.; Meléndez, E.; Expósito, A.; Izquierdo, J.M.; Gil, J.; Marrao, H.; Villalba-Jabonero, E.

2016-01-01

The Integrated Safety Assessment (ISA) methodology, developed by the Consejo de Seguridad Nuclear, has been applied to an analysis of Zion NPP for sequences with Loss of the Component Cooling Water System (CCWS). The ISA methodology proposal starts from the unfolding of the Dynamic Event Tree (DET). Results from this first step allow assessing the sequence delineation of standard Probabilistic Safety Analysis results. For some sequences of interest of the outlined DET, ISA then identifies the Damage Domain (DD). This is the region of uncertain times and/or parameters where a safety limit is exceeded, which indicates the occurrence of certain damage situation. This paper illustrates application of this concept obtained simulating sequences with MAAP and with TRACE. From information of simulation results of sequence transients belonging to the DD and the time-density probability distributions of the manual actions and of occurrence of stochastic phenomena, ISA integrates the dynamic reliability equations proposed to obtain the sequence contribution to the global Damage Exceedance Frequency (DEF). Reported results show a slight increase in the DEF for sequences investigated following a power uprate from 100% to 110%. This demonstrates the potential use of the method to help in the assessment of design modifications. - Highlights: • This paper illustrates an application of the ISA methodology to safety margins. • Dynamic Event Trees are useful tool for verifying the standard PSA Event Trees. • The ISA methodology takes into account the uncertainties in human action times. • The ISA methodology shows the Damage Exceedance Frequency increase in power uprates.

Systematic reviews: I. The correlation between laboratory tests on marginal quality and bond strength. II. The correlation between marginal quality and clinical outcome.

Science.gov (United States)

Heintze, Siegward D

2007-01-01

An accepted principle in restorative dentistry states that restorations should be placed with the best marginal quality possible to avoid postoperative sensitivity, marginal discoloration, and secondary caries. Different laboratory methods claim to predict the clinical performance of restorative materials, for example, tests of bond strength and microleakage and gap analysis. The purpose of this review was twofold: (1) find studies that correlated the results of bond strength tests with either microleakage or gap analysis for the same materials, and (2) find studies that correlated the results of microleakage and/or gaps with the clinical parameters for the same materials. Furthermore, influencing factors on the results of the laboratory tests were reviewed and assessed. For the first question, searches for studies were conducted in the MEDLINE database and IADR/AADR abtracts online with specific search and inclusion criteria. The outcome for each study was assessed on the basis of the statistical test applied in the study, and finally the number of studies with or without correlation was compiled. For the second question, results of the quantitative marginal analysis of Class V restorations published by the University of Zürich with the same test protocol and prospective clinical trials were searched that investigated the same materials for at least 2 years in Class V cavities. Pearson correlation coefficients were calculated for pooled data of materials and clinical outcome parameters such as retention loss, marginal discoloration, marginal integrity, and secondary caries. For the correlation of dye penetration and clinical outcome, studies on Class V restorations published by the same research institute were searched in MEDLINE that examined the same adhesive systems as the selected clinical trials. For the correlation bond strength/microleakage, 30 studies were included into the review, and for the correlation bond strength/gap analysis 18 studies. For both

Breast Conservation Therapy: The Influence of Molecular Subtype and Margins

International Nuclear Information System (INIS)

Demirci, Senem; Broadwater, Gloria; Marks, Lawrence B.; Clough, Robert; Prosnitz, Leonard R.

2012-01-01

Purpose: To evaluate treatment results and prognostic factors, especially margin status and molecular subtype, in early-stage breast cancer patients treated with breast conservation therapy (BCT). Methods and Materials: The records of 1,058 Stage I or II breast cancer patients treated with BCT (surgical excision plus radiotherapy) at Duke University Medical Center, Durham, North Carolina, from 1985–2005 were retrospectively reviewed. Conventional receptor analyses were used as surrogate markers for molecular subtype classification (luminal A, luminal B, Her2 positive, and basal like). Actuarial estimates of overall survival (OS), cause-specific survival (CSS), failure-free survival, and locoregional control (LRC) were computed by use of Kaplan-Meier plots. We analyzed prognostic variables for significance using Cox proportional hazards univariate and multivariate analysis. The study was approved by the Duke University Medical Center Institutional Review Board. Results: The median age of the patients was 56 years (range, 18–89 years). Of the patients, 80% had T1 disease and 66% N0 disease pathologically. With a median follow-up of 9.8 years, an in-breast recurrence developed in 53 patients and 10 patients had nodal failure. For all patients, the 10-year CSS rate was 94%; LRC rate, 94%; and failure-free survival rate, 88%. Luminal A patients had a CSS rate of 95% and LRC rate of 99%. Basal-type patients appeared to do worse, with regard to both CSS rate (74%) and LRC rate (76%), but the numbers were small and the difference was not statistically significant. LRC rates of patients with negative margins (widely negative, close, and extent of margin not known) were virtually identical (93%, 96%, and 94%, respectively). Those with positive margins appeared to fare slightly worse based on LRC rate (88%), but again, the numbers were small and the difference was not statistically significant. Conclusions: BCT remains the treatment of choice for early-stage breast cancer

Breast Conservation Therapy: The Influence of Molecular Subtype and Margins

Energy Technology Data Exchange (ETDEWEB)

Demirci, Senem, E-mail: senem.demirci@ege.edu.tr [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Radiation Oncology, Ege University Faculty of Medicine, Izmir (Turkey); Broadwater, Gloria [Department of Biostatistics and Bioinformatics, Duke Cancer Institute, Durham, NC (United States); Cancer and Leukemia Group B Statistical Center, Duke Cancer Institute, Durham, NC (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, NC (United States); Clough, Robert; Prosnitz, Leonard R. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

2012-07-01

Purpose: To evaluate treatment results and prognostic factors, especially margin status and molecular subtype, in early-stage breast cancer patients treated with breast conservation therapy (BCT). Methods and Materials: The records of 1,058 Stage I or II breast cancer patients treated with BCT (surgical excision plus radiotherapy) at Duke University Medical Center, Durham, North Carolina, from 1985-2005 were retrospectively reviewed. Conventional receptor analyses were used as surrogate markers for molecular subtype classification (luminal A, luminal B, Her2 positive, and basal like). Actuarial estimates of overall survival (OS), cause-specific survival (CSS), failure-free survival, and locoregional control (LRC) were computed by use of Kaplan-Meier plots. We analyzed prognostic variables for significance using Cox proportional hazards univariate and multivariate analysis. The study was approved by the Duke University Medical Center Institutional Review Board. Results: The median age of the patients was 56 years (range, 18-89 years). Of the patients, 80% had T1 disease and 66% N0 disease pathologically. With a median follow-up of 9.8 years, an in-breast recurrence developed in 53 patients and 10 patients had nodal failure. For all patients, the 10-year CSS rate was 94%; LRC rate, 94%; and failure-free survival rate, 88%. Luminal A patients had a CSS rate of 95% and LRC rate of 99%. Basal-type patients appeared to do worse, with regard to both CSS rate (74%) and LRC rate (76%), but the numbers were small and the difference was not statistically significant. LRC rates of patients with negative margins (widely negative, close, and extent of margin not known) were virtually identical (93%, 96%, and 94%, respectively). Those with positive margins appeared to fare slightly worse based on LRC rate (88%), but again, the numbers were small and the difference was not statistically significant. Conclusions: BCT remains the treatment of choice for early-stage breast cancer

Scientific Ocean Drilling to Assess Submarine Geohazards along European Margins

Science.gov (United States)

Ask, M. V.; Camerlenghi, A.; Kopf, A.; Morgan, J. K.; Ocean DrillingSeismic Hazard, P. E.

2008-12-01

Submarine geohazards are some of the most devastating natural events in terms of lives lost and economic impact. Earthquakes pose a big threat to society and infrastructure, but the understanding of their episodic generation is incomplete. Tsunamis are known for their potential of striking coastlines world-wide. Other geohazards originating below the sea surface are equally dangerous for undersea structures and the coastal population: submarine landslides and volcanic islands collapse with little warning and devastating consequences. The European scientific community has a strong focus on geohazards along European and nearby continental margins, especially given their high population densities, and long historic and prehistoric record of hazardous events. For example, the Mediterranean is surrounded by very densely-populated coastline and is the World's leading holiday destination, receiving up 30% of global tourism. In addition, its seafloor is criss-crossed by hydrocarbon pipelines and telecommunication cables. However, the governing processes and recurrence intervals of geohazards are still poorly understood. Examples include, but are not limited to, earthquakes and volcanic eruptions along the active tectonic margins of the Mediterranean and Sea of Marmara, landslides on both active and passive margins, and tsunamites and seismites in the sedimentary record that suggest a long history of similar events. The development of geophysical networks, drilling, sampling and long-term monitoring are crucial to the understanding of earthquake, landslide, and tsunami processes, and to mitigate the associated risks in densely populated and industrialized regions such as Europe. Scientific drilling, particularly in the submarine setting, offers a unique tool to obtain drill core samples, borehole measurements and long-term observations. Hence, it is a critical technology to investigate past, present, and possible future influences of hazardous processes in this area. The

Indian Ocean margins

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A

in the latter two areas. Some of these fluxes are expected to be substantial in the case of Indonesian continental margins and probably also across the eastern coasts of Africa not covered in this chapter. However, a dearth of information makes these margins...

Quantification of margins and mixed uncertainties using evidence theory and stochastic expansions

International Nuclear Information System (INIS)

Shah, Harsheel; Hosder, Serhat; Winter, Tyler

2015-01-01

The objective of this paper is to implement Dempster–Shafer Theory of Evidence (DSTE) in the presence of mixed (aleatory and multiple sources of epistemic) uncertainty to the reliability and performance assessment of complex engineering systems through the use of quantification of margins and uncertainties (QMU) methodology. This study focuses on quantifying the simulation uncertainties, both in the design condition and the performance boundaries along with the determination of margins. To address the possibility of multiple sources and intervals for epistemic uncertainty characterization, DSTE is used for uncertainty quantification. An approach to incorporate aleatory uncertainty in Dempster–Shafer structures is presented by discretizing the aleatory variable distributions into sets of intervals. In view of excessive computational costs for large scale applications and repetitive simulations needed for DSTE analysis, a stochastic response surface based on point-collocation non-intrusive polynomial chaos (NIPC) has been implemented as the surrogate for the model response. The technique is demonstrated on a model problem with non-linear analytical functions representing the outputs and performance boundaries of two coupled systems. Finally, the QMU approach is demonstrated on a multi-disciplinary analysis of a high speed civil transport (HSCT). - Highlights: • Quantification of margins and uncertainties (QMU) methodology with evidence theory. • Treatment of both inherent and epistemic uncertainties within evidence theory. • Stochastic expansions for representation of performance metrics and boundaries. • Demonstration of QMU on an analytical problem. • QMU analysis applied to an aerospace system (high speed civil transport)

Convolution method and CTV-to-PTV margins for finite fractions and small systematic errors

International Nuclear Information System (INIS)

Gordon, J J; Siebers, J V

2007-01-01

The van Herk margin formula (VHMF) relies on the accuracy of the convolution method (CM) to determine clinical target volume (CTV) to planning target volume (PTV) margins. This work (1) evaluates the accuracy of the CM and VHMF as a function of the number of fractions N and other parameters, and (2) proposes an alternative margin algorithm which ensures target coverage for a wider range of parameter values. Dose coverage was evaluated for a spherical target with uniform margin, using the same simplified dose model and CTV coverage criterion as were used in development of the VHMF. Systematic and random setup errors were assumed to be normally distributed with standard deviations Σ and σ. For clinically relevant combinations of σ, Σ and N, margins were determined by requiring that 90% of treatment course simulations have a CTV minimum dose greater than or equal to the static PTV minimum dose. Simulation results were compared with the VHMF and the alternative margin algorithm. The CM and VHMF were found to be accurate for parameter values satisfying the approximate criterion: σ[1 - γN/25] 0.2, because they failed to account for the non-negligible dose variability associated with random setup errors. These criteria are applicable when σ ∼> σ P , where σ P = 0.32 cm is the standard deviation of the normal dose penumbra. (Qualitative behaviour of the CM and VHMF will remain the same, though the criteria might vary if σ P takes values other than 0.32 cm.) When σ P , dose variability due to random setup errors becomes negligible, and the CM and VHMF are valid regardless of the values of Σ and N. When σ ∼> σ P , consistent with the above criteria, it was found that the VHMF can underestimate margins for large σ, small Σ and small N. A potential consequence of this underestimate is that the CTV minimum dose can fall below its planned value in more than the prescribed 10% of treatments. The proposed alternative margin algorithm provides better margin

Systems considerations in seismic margin evaluations

International Nuclear Information System (INIS)

Buttermer, D.R.

1987-01-01

Increasing knowledge in the geoscience field has led to the understanding that, although highly unlikely, it is possible for a nuclear power plant to be subjected to earthquake ground motion greater than that for which the plant was designed. While it is recognized that there are conservatisms inherent in current design practices, interest has developed in evaluating the seismic risk of operating plants. Several plant-specific seismic probabilistic risk assessments (SPRA) have been completed to address questions related to the seismic risk of a plant. The results from such SPRAs are quite informative, but such studies may entail a considerable amount of expensive analysis of large portions of the plant. As an alternative to an SPRA, it may be more practical to select an earthquake level above the design basis for which plant survivability is to be demonstrated. The principal question to be addressed in a seismic margin evaluation is: At what ground motion levels does one have a high confidence that the probability of seismically induced core damage is sufficiently low? In a seismic margin evaluation, an earthquake level is selected (based on site-specific geoscience considerations) for which a stable, long-term safe shutdown condition is to be demonstrated. This prespecified earthquake level is commonly referred to as the seismic margin earthquake (SME). The Electric Power Research Institute is currently supporting a research project to develop procedures for use by the utilities to allow them to perform nuclear plant seismic margin evaluations. This paper describes the systems-related aspects of these procedures

Seismic Margin of 500MWe PFBR Beyond Safe Shutdown Earthquake

International Nuclear Information System (INIS)

Sajish, S.D.; Chellapandi, P.; Chetal, S.C.

2012-01-01

Summary: • Seismic design aspects of safety related systems and components of PFBR is discussed with a focus on reactor assembly components. • PFBR is situated in a low seismic area with a peak ground acceleration value of 0.156 g. • The design basis ground motion parameters for the seismic design are evaluated by deterministic method and confirmed by probabilistic seismic hazard analysis. • Review of the seismic design of various safety related systems and components indicate that margin is available to meet any demand due to an earthquake beyond SSE. • Reactor assembly vessels are the most critical components w.r.t seismic loading. • Minimum safety margin is 1.41 for plastic deformation and 1.46 against buckling. • From the preliminary investigation we come to the conclusion that PFBR can withstand an earthquake up to 0.22 g without violating any safety limits. • Additional margin can be estimated by detailed fragility analysis and seismic margin assessment methods

Lithosphere structure and subsidence evolution of the conjugate S-African and Argentine margins

Science.gov (United States)

Dressel, Ingo; Scheck-Wenderoth, Magdalena; Cacace, Mauro; Götze, Hans-Jürgen; Franke, Dieter

2016-04-01

The bathymetric evolution of the South Atlantic passive continental margins is a matter of debate. Though it is commonly accepted that passive margins experience thermal subsidence as a result of lithospheric cooling as well as load induced subsidence in response to sediment deposition it is disputed if the South Atlantic passive margins were affected by additional processes affecting the subsidence history after continental breakup. We present a subsidence analysis along the SW African margin and offshore Argentina and restore paleobathymetries to assess the subsidence evolution of the margin. These results are discussed with respect to mechanisms behind margin evolution. Therefore, we use available information about the lithosphere-scale present-day structural configuration of these margins as a starting point for the subsidence analysis. A multi 1D backward modelling method is applied to separate individual subsidence components such as the thermal- as well as the load induced subsidence and to restore paleobathymetries for the conjugate margins. The comparison of the restored paleobathymetries shows that the conjugate margins evolve differently: Continuous subsidence is obtained offshore Argentina whereas the subsidence history of the SW African margin is interrupted by phases of uplift. This differing results for both margins correlate also with different structural configurations of the subcrustal mantle. In the light of these results we discuss possible implications for uplift mechanisms.

Impact of organ shape variations on margin concepts for cervix cancer ART.

Science.gov (United States)

Seppenwoolde, Yvette; Stock, Markus; Buschmann, Martin; Georg, Dietmar; Bauer-Novotny, Kwei-Yuang; Pötter, Richard; Georg, Petra

2016-09-01

Target and organ movement motivate adaptive radiotherapy for cervix cancer patients. We investigated the dosimetric impact of margin concepts with different levels of complexity on both organ at risk (OAR) sparing and PTV coverage. Weekly CT and daily CBCT scans were delineated for 10 patients. The dosimetric impact of organ shape variations were evaluated for four (isotropic) margin concepts: two static PTVs (PTV 6mm and PTV 15mm ), a PTV based on ITV of the planning CT and CBCTs of the first treatment week (PTV ART ITV ) and an adaptive PTV based on a library approach (PTV ART Library ). Using static concepts, OAR doses increased with large margins, while smaller margins compromised target coverage. ART PTVs resulted in comparable target coverage and better sparing of bladder (V40Gy: 15% and 7% less), rectum (V40Gy: 18 and 6cc less) and bowel (V40Gy: 106 and 15cc less) compared to PTV 15mm . Target coverage evaluation showed that for elective fields a static 5mm margin sufficed. PTV ART Library achieved the best dosimetric results. However when weighing clinical benefit against workload, ITV margins based on repetitive movement evaluation during the first week also provide improvements over static margin concepts. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Topographic distribution of inguinal lymph nodes metastasis: significance in determination of treatment margin for elective inguinal lymph nodes irradiation of low pelvic tumors

International Nuclear Information System (INIS)

Wang, C.J.; Chin, Y.Y.; Leung, Stephen Wan; Chen, H.C.; Sun, L.M.; Fang, F.M.

1996-01-01

Purpose: To study the distribution of gross inguinal lymph node metastasis and, in particular, its correlation with major pelvic bony structures on a simulation film. Methods and Materials: Thirty-seven cases of low pelvic tumors having gross inguinal lymph node metastasis that were treated with radiation therapy between November 1987 and December 1992 were segregated for study. The patient's nodes were palpated and marked with lead wire before the simulation film was taken. The geometric center of the usually round or elliptical node on the film was assumed to be the origin of the previously uninfested node. A total of 84 such labeled nodes was obtained from these 37 cases. These centers were transferred to and mapped collectively on a new simulation film showing major pelvic bony structures of left hemipelvis and upper femur. Results: Distribution of gross inguinal lymph nodes was found confined to the following area, as related to major pelvic bony structure: laterally, just abutting the tangential line that passes through lateral border of the femoral head; medially: 3 cm away from the body's midline axis; superiorly: 1 cm below the line that joins both upper borders of the femoral head; inferiorly: 2.5 cm below the low borders of ischial tuberosity. According to this rectangular boundary, three nodes were out of field, nine nodes near the border less than 1 cm margin. This area adequately covered 86% (72 of 84) of the studied nodes. Conclusion: Distribution study is important in determining the treatment margin. In general, an additional 1-2 cm beyond the area described above is the recommended treatment margin for elective inguinal lymph nodes irradiation with high confidence level of coverage.

Need for a marginal methodology in assessing natural gas system methane emissions in response to incremental consumption.

Science.gov (United States)

Mac Kinnon, Michael; Heydarzadeh, Zahra; Doan, Quy; Ngo, Cuong; Reed, Jeff; Brouwer, Jacob

2018-05-17

Accurate quantification of methane emissions from the natural gas system is important for establishing greenhouse gas inventories and understanding cause and effect for reducing emissions. Current carbon intensity methods generally assume methane emissions are proportional to gas throughput so that increases in gas consumption yield linear increases in emitted methane. However, emissions sources are diverse and many are not proportional to throughput. Insights into the causal drivers of system methane emissions, and how system-wide changes affect such drivers are required. The development of a novel cause-based methodology to assess marginal methane emissions per unit of fuel consumed is introduced. The carbon intensities of technologies consuming natural gas are critical metrics currently used in policy decisions for reaching environmental goals. For example, the low-carbon fuel standard in California uses carbon intensity to determine incentives provided. Current methods generally assume methane emissions from the natural gas system are completely proportional to throughput. The proposed cause-based marginal emissions method will provide a better understanding of the actual drivers of emissions to support development of more effective mitigation measures. Additionally, increasing the accuracy of carbon intensity calculations supports the development of policies that can maximize the environmental benefits of alternative fuels, including reducing greenhouse gas emissions.

On marginal regeneration

NARCIS (Netherlands)

Stein, H.N.

1991-01-01

On applying the marginal regeneration concept to the drainage of free liquid films, problems are encountered: the films do not show a "neck" of minimum thickness at the film/border transition; and the causes of the direction dependence of the marginal regeneration are unclear. Both problems can be

Postresection CA19-9 and margin status as predictors of recurrence after adjuvant treatment for pancreatic carcinoma: Analysis of NRG oncology RTOG trial 9704

Directory of Open Access Journals (Sweden)

William F. Regine, MD

2018-04-01

Full Text Available Purpose: NRG Oncology RTOG 9704 was the first adjuvant trial to validate the prognostic value of postresection CA19-9 levels for survival in patients with pancreatic carcinoma. The data resulting from this study also provide information about predictors of recurrence that may be used to tailor individualized management in this disease setting. This secondary analysis assessed the prognostic value of postresection CA19-9 and surgical margin status (SMS in predicting patterns of disease recurrence. Methods and materials: This multicenter cooperative trial included participants who were enrolled as patients at oncology treatment sites in the United States and Canada. The study included 451 patients analyzable for SMS, of whom 385 were eligible for postresection CA19-9 analysis. Postresection CA19-9 was analyzed at cut points of 90, 180, and continuously. Patterns of disease recurrence included local/regional recurrence (LRR and distant failure (DF. Multivariable analyses included treatment, tumor size, and nodal status. To adjust for multiple comparisons, a P value of ≤ .01 was considered statistically significant and > .01 to ≤ .05 to be a trend. Results: For CA19-9, 132 (34% patients were Lewis antigen–negative (no CA19-9 expression, 200 (52% had levels <90, and 220 (57% had levels <180. A total of 188 patients (42% had negative margins, 152 (34% positive, and 111 (25% unknown. On univariate analysis, CA19-9 cut at 90 was associated with increases in LRR (trend and DF. Results were similar at the 180 cut point. SMS was not associated with an increase in LRR on univariate or multivariate analyses. On multivariable analysis, CA19-9 ≥ 90 was associated with increased LRR and DF. Results were similar at the 180 cut point. Conclusions: In this prospective evaluation, postresection CA19-9 was a significant predictor of both LRR and DF, whereas SMS was not. These findings support consideration of adjuvant radiation therapy dose

Improved statistical confirmation of margins for setpoints and transients

International Nuclear Information System (INIS)

Nutt, W.T.

2001-01-01

Framatome ANP Richland, Inc. has developed an integrated, automated, statistical methodology for Pressurized Water Reactors (PWRs). Margins for transients and calculated trips are confirmed using several new applications of probability theory. The methods used for combining statistics reduces the conservatisms inherent in conventional methods and avoids the numerical limitations and time constraints imposed by Monte Carlo techniques. The new methodology represents the state of the art in the treatment of uncertainties for reactor protection systems. It all but eliminates concerns with the calculated trips for PWRs and by improving the margin for all transients will allow for far more aggressive peaking limits and fuel management schemes. The automated nature of the bulk of this process saves Framatome ANP time and effort, minimizes the potential for errors and makes the analysis for all cycles and plants consistent. The enhanced margins remove analytical limitations from the customer and allow for more economical operation of the plant. (authors)

Safety margins associated with containment structures under dynamic loading

International Nuclear Information System (INIS)

Lu, S.C.

1978-01-01

A technical basis for assessing the true safety margins of containment structures involved with MARK I boiling water reactor reevaluation activities is presented. It is based on the results of a plane-strain, large displacement, elasto-plastic, finite-element analysis of a thin cylindrical shell subjected to external and internal pressure pulses. An analytical procedure is presented for estimating the ultimate load capacity of the thin shell structure, and subsequently, for quantifying the design margins of safety for the type of loads under consideration. For defining failure of structures, a finite strain failure criterion is derived that accounts for multiaxiality effects

Refining margins and prospects

International Nuclear Information System (INIS)

Baudouin, C.; Favennec, J.P.

1997-01-01

Refining margins throughout the world have remained low in 1996. In Europe, in spite of an improvement, particularly during the last few weeks, they are still not high enough to finance new investments. Although the demand for petroleum products is increasing, experts are still sceptical about any rapid recovery due to prevailing overcapacity and to continuing capacity growth. After a historical review of margins and an analysis of margins by regions, we analyse refining over-capacities in Europe and the unbalances between production and demand. Then we discuss the current situation concerning barriers to the rationalization, agreements between oil companies, and the consequences on the future of refining capacities and margins. (author)

Safety margins in deterministic safety analysis

International Nuclear Information System (INIS)

Viktorov, A.

2011-01-01

The concept of safety margins has acquired certain prominence in the attempts to demonstrate quantitatively the level of the nuclear power plant safety by means of deterministic analysis, especially when considering impacts from plant ageing and discovery issues. A number of international or industry publications exist that discuss various applications and interpretations of safety margins. The objective of this presentation is to bring together and examine in some detail, from the regulatory point of view, the safety margins that relate to deterministic safety analysis. In this paper, definitions of various safety margins are presented and discussed along with the regulatory expectations for them. Interrelationships of analysis input and output parameters with corresponding limits are explored. It is shown that the overall safety margin is composed of several components each having different origins and potential uses; in particular, margins associated with analysis output parameters are contrasted with margins linked to the analysis input. While these are separate, it is possible to influence output margins through the analysis input, and analysis method. Preserving safety margins is tantamount to maintaining safety. At the same time, efficiency of operation requires optimization of safety margins taking into account various technical and regulatory considerations. For this, basic definitions and rules for safety margins must be first established. (author)

Image-Guided Radiotherapy via Daily Online Cone-Beam CT Substantially Reduces Margin Requirements for Stereotactic Lung Radiotherapy

International Nuclear Information System (INIS)

Grills, Inga S.; Hugo, Geoffrey; Kestin, Larry L.; Galerani, Ana Paula; Chao, K. Kenneth; Wloch, Jennifer; Yan Di

2008-01-01

Purpose: To determine treatment accuracy and margins for stereotactic lung radiotherapy with and without cone-beam CT (CBCT) image guidance. Methods and Materials: Acquired for the study were 308 CBCT of 24 patients with solitary peripheral lung tumors treated with stereotactic radiotherapy. Patients were immobilized in a stereotactic body frame (SBF) or alpha-cradle and treated with image guidance using daily CBCT. Four (T1) or five (T2/metastatic) 12-Gy fractions were prescribed to the planning target volume (PTV) edge. The PTV margin was ≥5 mm depending on a pretreatment estimate of tumor excursion. Initial daily setup was according to SBF coordinates or tattoos for alpha-cradle cases. A CBCT was performed and registered to the planning CT using soft tissue registration of the target. The initial setup error/precorrection position, was recorded for the superior-inferior, anterior-posterior, and medial-lateral directions. The couch was adjusted to correct the tumor positional error. A second CBCT verified tumor position after correction. Patients were treated in the corrected position after the residual errors were ≤2 mm. A final CBCT after treatment assessed intrafraction tumor displacement. Results: The precorrection systematic (Σ) and random errors (σ) for the population ranged from 2-3 mm for SBF and 2-6 mm for alpha-cradle patients; postcorrection errors ranged from 0.4-1.0 mm. Calculated population margins were 9 to 13 mm (SBF) and 10-14 mm (cradle) precorrection, 1-2 mm (SBF), and 2-3 mm (cradle) postcorrection, and 2-4 mm (SBF) and 2-5 mm (cradle) posttreatment. Conclusions: Setup for stereotactic lung radiotherapy using a SBF or alpha-cradle alone is suboptimal. CBCT image guidance significantly improves target positioning and substantially reduces required target margins and normal tissue irradiation

Marginal Models for Categorial Data

NARCIS (Netherlands)

Bergsma, W.P.; Rudas, T.

2002-01-01

Statistical models defined by imposing restrictions on marginal distributions of contingency tables have received considerable attention recently. This paper introduces a general definition of marginal log-linear parameters and describes conditions for a marginal log-linear parameter to be a smooth

Robust Adaptation? Assessing the sensitivity of safety margins in flood defences to uncertainty in future simulations - a case study from Ireland.

Science.gov (United States)

Murphy, Conor; Bastola, Satish; Sweeney, John

2013-04-01

Climate change impact and adaptation assessments have traditionally adopted a 'top-down' scenario based approach, where information from different Global Climate Models (GCMs) and emission scenarios are employed to develop impacts led adaptation strategies. Due to the tradeoffs in the computational cost and need to include a wide range of GCMs for fuller characterization of uncertainties, scenarios are better used for sensitivity testing and adaptation options appraisal. One common approach to adaptation that has been defined as robust is the use of safety margins. In this work the sensitivity of safety margins that have been adopted by the agency responsible for flood risk management in Ireland, to the uncertainty in future projections are examined. The sensitivity of fluvial flood risk to climate change is assessed for four Irish catchments using a large number of GCMs (17) forced with three emissions scenarios (SRES A1B, A2, B1) as input to four hydrological models. Both uncertainty within and between hydrological models is assessed using the GLUE framework. Regionalisation is achieved using a change factor method to infer changes in the parameters of a weather generator using monthly output from the GCMs, while flood frequency analysis is conducted using the method of probability weighted moments to fit the Generalised Extreme Value distribution to ~20,000 annual maxima series. The sensitivity of design margins to the uncertainty space considered is visualised using risk response surfaces. The hydrological sensitivity is measured as the percentage change in flood peak for specified recurrence intervals. Results indicate that there is a considerable residual risk associated with allowances of +20% when uncertainties are accounted for and that the risk of exceedence of design allowances is greatest for more extreme, low frequency events with considerable implication for critical infrastructure, e.g., culverts, bridges, flood defences whose designs are normally

How does imaging frequency and soft tissue motion affect the PTV margin size in partial breast and boost radiotherapy?

International Nuclear Information System (INIS)

Harris, Emma J.; Donovan, Ellen M.; Coles, Charlotte E.; Boer, Hans C.J. de; Poynter, Andrew; Rawlings, Christine; Wishart, Gordon C.; Evans, Philip M.

2012-01-01

Purpose: This study investigates (i) the effect of verification protocols on treatment accuracy and PTV margins for partial breast and boost breast radiotherapy with short fractionation schema (15 fractions), (ii) the effect of deformation of the excision cavity (EC) on PTV margin size, (iii) the imaging dose required to achieve specific PTV margins. Methods and materials: Verification images using implanted EC markers were studied in 36 patients. Target motion was estimated for a 15 fraction partial breast regimen using imaging protocols based on on-line and off-line motion correction strategies (No Action Level (NAL) and the extended NAL (eNAL) protocols). Target motion was used to estimate a PTV margin for each protocol. To evaluate treatment errors due to deformation of the excision cavity, individual marker positions were obtained from 11 patients. The mean clip displacement and daily variation in clip position during radiotherapy were determined and the contribution of these errors to PTV margin calculated. Published imaging dose data were used to estimate total dose for each protocol. Finally the number of images required to obtain a specific PTV margin was evaluated and hence, the relationship between PTV margins and imaging dose was investigated. Results: The PTV margin required to account for excision cavity motion, varied between 10.2 and 2.4 mm depending on the correction strategy used. Average clip movement was 0.8 mm and average variation in clip position during treatment was 0.4 mm. The contribution to PTV margin from deformation was estimated to be small, less than 0.2 mm for both off-line and on-line correction protocols. Conclusion: A boost or partial breast PTV margin of ∼10 mm, is possible with zero imaging dose and workload, however, patients receiving boost radiotherapy may benefit from a margin reduction of ∼4 mm with imaging doses from 0.4 cGy to 25 cGy using an eNAL protocol. PTV margin contributions from deformation errors are likely

Effect of At-home and In-office Bleaching on Marginal Microleakage in Composite Resin Restorations using Two Adhesive Systems.

Science.gov (United States)

Klein, Celso A; da Silva, Douglas; Reston, Eduardo G; Borghetti, Diana Lb; Zimmer, Roberto

2018-03-01

The aim of this study is to assess marginal microleakage of cervical cavities restored with composite resins and two different adhesive techniques subjected to at-home and in-office bleaching. In this randomized, blind laboratory experiment, 60 bovine teeth recently extracted were collected and divided into six groups (n = 10 each group). The teeth received cervical cavity preparations (2 mm × 3 mm × 1 mm) with enamel margins. Two different adhesive systems were used (Single Bond 2 and Clearfil SE Bond), in addition to composite resin (Z250). Restored teeth received two different bleaching gels (Opalescence PF and Opalescence Boost). Teeth were thermo-cycled and analyzed under confocal laser scanning microscopy. No significant differences were observed (p > 0.05) in microleakage scores between the two groups not subjected to bleaching nor between the four groups that received bleaching treatment (p > 0.05), regardless of the gel and adhesive system employed. However, when comparing nonbleached with bleached teeth, those not subjected to bleaching showed statistically lower marginal microleakage scores (p bleaching agents used both at-home and in-office, regardless of the adhesive system employed (total-etch or self-etch). Both at-home and in-office bleaching agents have an influence on the adhesive interface of resin restorations, producing changes and inducing marginal leakage.

Distributions with given marginals and statistical modelling

CERN Document Server

Fortiana, Josep; Rodriguez-Lallena, José

2002-01-01

This book contains a selection of the papers presented at the meeting `Distributions with given marginals and statistical modelling', held in Barcelona (Spain), July 17-20, 2000. In 24 chapters, this book covers topics such as the theory of copulas and quasi-copulas, the theory and compatibility of distributions, models for survival distributions and other well-known distributions, time series, categorical models, definition and estimation of measures of dependence, monotonicity and stochastic ordering, shape and separability of distributions, hidden truncation models, diagonal families, orthogonal expansions, tests of independence, and goodness of fit assessment. These topics share the use and properties of distributions with given marginals, this being the fourth specialised text on this theme. The innovative aspect of the book is the inclusion of statistical aspects such as modelling, Bayesian statistics, estimation, and tests.

Sensitivity of postplanning target and OAR coverage estimates to dosimetric margin distribution sampling parameters.

Science.gov (United States)

Xu, Huijun; Gordon, J James; Siebers, Jeffrey V

2011-02-01

accuracy of coverage estimates depends on angular and radial DMD sampling parameters omega or omega eff and delta, as well as the employed sampling technique. Target deltaQ/ sampling parameters omega or omega eef = 20 degrees, delta =1 mm. Better accuracy (target /deltaQ sampling points decreases, the isotropic sampling method maintains better accuracy than fixed angular sampling. Coverage estimates for post-planning evaluation are essential since coverage values of targets and OARs often differ from the values implied by the static margin-based plans. Finer sampling of the DMD enables more accurate assessment of the effect of geometric uncertainties on coverage estimates prior to treatment. DMD sampling with omega or omega eff = 10 degrees and delta = 0.5 mm should be adequate for planning purposes.

Evaluation of Resection Margins in Breast Conservation Therapy: The Pathology Perspective—Past, Present, and Future

Directory of Open Access Journals (Sweden)

Rajyasree Emmadi

2012-01-01

Full Text Available Tumor surgical resection margin status is important for any malignant lesion. When this occurs in conjunction with efforts to preserve or conserve the afflicted organ, these margins become extremely important. With the demonstration of no difference in overall survival between mastectomy versus lumpectomy and radiation for breast carcinoma, there is a definite trend toward smaller resections combined with radiation, constituting “breast-conserving therapy.” Tumor-free margins are therefore key to the success of this treatment protocol. We discuss the various aspects of margin status in this setting, from a pathology perspective, incorporating the past and current practices with a brief glimpse of emerging future techniques.

The use of active breathing control (ABC) to reduce margin for breathing motion

International Nuclear Information System (INIS)

Wong, John W.; Sharpe, Michael B.; Jaffray, David A.; Kini, Vijay R.; Robertson, John M.; Stromberg, Jannifer S.; Martinez, Alavro A.

1999-01-01

. The variation of the organ positions and volumes for the different scans were quantified and compared. Results: The ABC procedure was well tolerated in the 12 patients. When ABC was applied near the end of normal expiration, the minimal duration of active breath-hold was 15 s for 1 patient with lung cancer, and 20 s or more for all other patients. The duration was greater than 40 s for 2 patients with Hodgkin's disease when ABC was applied during deep inspiration. Scan artifacts associated with normal breathing motion were not observed in the ABC scans. The analysis of the small set of intrafraction scan data indicated that with ABC, the liver volumes were reproducible at about 1%, and lung volumes to within 6%. The excursions of a 'center of target' parameter for the livers were less than 1 mm at the same respiratory phase, but were larger than 4 mm at the extremes of the breathing cycle. The inter-fraction scan study indicated that daily setup variation contributed to the uncertainty in assessing the reproducibility of organ immobilization with ABC between treatment fractions. Conclusion: The results were encouraging; ABC provides a simple means to minimize breathing motion. When applied for CT scanning and treatment, the ABC procedure requires no more than standard operation of the CT scanner or the medical accelerator. The ABC scans are void of motion artifacts commonly seen on fast spiral CT scans. When acquired at different points in the breathing cycle, these ABC scans show organ motion in three-dimension (3D) that can be used to enhance treatment planning. Reproducibility of organ immobilization with ABC throughout the course of treatment must be quantified before the procedure can be applied to reduce margin for conformal treatment

Digital Margins : How spatially and socially marginalized communities deal with digital exclusion

NARCIS (Netherlands)

Salemink, Koen

2016-01-01

The increasing importance of the Internet as a means of communication has transformed economies and societies. For spatially and socially marginalized communities, this transformation has resulted in digital exclusion and further marginalization. This book presents a study of two kinds of

On the assessment of marginal life saving costs for risk acceptance criteria

DEFF Research Database (Denmark)

Fischer, Katharina; Virguez, Edgar; Sánchez-Silva, Mauricio

2013-01-01

: The definition of the marginal life saving costs, the discount rate used for comparing costs and benefits that accrue at different points in time and the time horizon over which future consequences of the decision are taken into account. In the present paper these issues are discussed based on a clear...

Skin cancer margin analysis within minutes with full-field OCT (Conference Presentation)

Science.gov (United States)

Dalimier, Eugénie; Ogrich, Lauren; Morales, Diego; Cusack, Carrie Ann; Abdelmalek, Mark; Boccara, Claude; Durkin, John

2017-02-01

Non-melanoma skin cancer (NMSC) is the most common cancer. Treatment consists of surgical removal of the skin cancer. Traditional excision involves the removal of the visible skin cancer with a significant margin of normal skin. On cosmetically sensitive areas, Mohs micrographic tissue is the standard of care. Mohs uses intraoperative microscopic margin assessment which minimizes the surgical defect and can help reduce the recurrence rate by a factor of 3. The current Mohs technique relies on frozen section tissue slide preparation which significantly lengthens operative time and requires on-site trained histotechnicians. Full-Field Optical Coherence Tomography (FFOCT) is a novel optical imaging technique which provides a quick and efficient method to visualize cancerous areas in minutes, without any preparation or destruction of the tissue. This study aimed to evaluate the potential of FFOCT for the analysis of skin cancer margins during Mohs surgery. Over 150 images of Mohs specimens were acquired intraoperatively with FFOCT before frozen section analysis. The imaging procedure took less than 5 minutes for each specimen. No artifacts on histological preparation were found arising from FFOCT manipulation; however frozen section artifact was readily seen on FFOCT. An atlas was established with FFOCT images and corresponding histological slides to reveal FFOCT reading criteria of normal and cancerous structures. Blind analysis showed high concordance between FFOCT and histology. FFOCT can potentially reduce recurrence rates while maintaining short surgery times, optimize clinical workflow, and decrease healthcare costs. For the patient, this translates into smaller infection risk, decreased stress, and better comfort.

Impact of inter- and intrafraction deviations and residual set-up errors on PTV margins. Different alignment techniques in 3D conformal prostate cancer radiotherapy

International Nuclear Information System (INIS)

Langsenlehner, T.; Doeller, C.; Winkler, P.; Kapp, K.S.; Galle, G.

2013-01-01

The aim of this work was to analyze interfraction and intrafraction deviations and residual set-up errors (RSE) after online repositioning to determine PTV margins for 3 different alignment techniques in prostate cancer radiotherapy. The present prospective study included 44 prostate cancer patients with implanted fiducials treated with three-dimensional (3D) conformal radiotherapy. Daily localization was based on skin marks followed by marker detection using kilovoltage (kV) imaging and subsequent patient repositioning. Additionally, in-treatment megavoltage (MV) images were obtained for each treatment field. In an off-line analysis of 7,273 images, interfraction prostate motion, RSE after marker-based prostate localization, prostate position during each treatment session, and the effect of treatment time on intrafraction deviations were analyzed to evaluate PTV margins. Margins accounting for interfraction deviation, RSE and intrafraction motion were 14.1, 12.9, and 15.1 mm in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) direction for skin mark alignment and 9.6, 8.7, and 2.6 mm for bony structure alignment, respectively. Alignment to implanted markers required margins of 4.6, 2.8, and 2.5 mm. As margins to account for intrafraction motion increased with treatment prolongation PTV margins could be reduced to 3.9, 2.6, and 2.4 mm if treatment time was ≤ 4 min. With daily online correction and repositioning based on implanted fiducials, a significant reduction of PTV margins can be achieved. The use of an optimized workflow with faster treatment techniques such as volumetric modulated arc techniques (VMAT) could allow for a further decrease. (orig.)

Informing practice regarding marginalization: the application of the Koci Marginality Index.

Science.gov (United States)

Koci, Anne Floyd; McFarlane, Judith; Nava, Angeles; Gilroy, Heidi; Maddoux, John

2012-12-01

The 49th World Health Assembly of the World Health Organization (WHO) declared violence as the leading worldwide public health problem with a focus on the increase in the incidence of injuries to women. Violence against women is an international epidemic with specific instruments required to measure the impact on women's functioning. This article describes the application of the Koci Marginality Index (KMI), a 5-item scale to measure marginality, to the baseline data of a seven-year prospective study of 300 abused women: 150 first time users of a shelter and 150 first time applicants for a protection order from the justice system. Validity and reliability of the Koci Marginality Index and its usefulness for best clinical practice and for policy decisions for abused women's health are discussed. The 49th World Health Assembly of the World Health Organization (WHO) declared violence as the leading worldwide public health problem and focused on the increase in the incidence of injuries to women (Krug et al., 2002 ). Violence against women in the form of intimate partner violence (IPV) is costly in terms of dollars and health. In the United States in 2003, estimated costs of IPV approached $8.3 billion (Centers for Disease Control and Prevention [CDC], 2011). Outcomes related to severity of IPV vary but in 2003 victims suffering severe IPV lost nearly 8 million days of paid work, and greater than 5 million days of household productivity annually (CDC, 2011). Besides the evident financial cost of IPV, research confirms that exposure to IPV impacts a woman's health immediately and in the long-term (Breiding, Black, & Ryan, 2008 ; Campbell, 2002 ; CDC, 2011). Such sequela adversely affect the health of women and may increase their marginalization, a concept akin to isolation that may further increase negative effects on health outcomes. Immigrant women are at high risk for IPV (Erez, 2002 ) and those without documentation are at higher risk for marginalization (Montalvo

Whipple Resection: Concordance Between Frozen Section And Permanent Section Diagnosis Of Surgical Margins.

Science.gov (United States)

Bilal, Muhammad; Tariq, Hina; Mamoon, Nadira

2018-01-01

Margin assessment is done in Whipple procedures which are usually performed to resect tumours of head of pancreas and ampullary/periampullary region. Aims and objective of the study are to determine the concordance between frozen sections (FS) and permanent sections (PS) of surgical margins in Whipple resections. It is a retrospective study, from January 2008 to January 2015 (07 years). It includes the specimen with malignancy in final report and for which FS of pancreatic and/or CBD margin(s) were requested. Data was retrieved from Laboratory information system (LIS) database. Of the 41 bile duct margins in cases of ampullary tumours, 03 were positive on FS as well as PS, 35 were negative on FS as well as on PS. Results showed 100% sensitivity, 92.1% specificity, 50% PPV and 100% NPV. Results of 36 pancreatic margins in cases of ampullary showed 100% sensitivity, 97.1% specificity, 50% PPV and 100% NPV. In pancreatic carcinoma cases, none of CBD margins were reported as positive on FS, 02 margins reported as negative were found positive on PS, while 17 were negative on FS as well as PS. Results showed 100% specificity and 89.5% NPV. Of the 27 pancreatic margins tested in pancreatic tumours 100% sensitivity, 94.1% specificity, 88.9% PPV and 100% NPV was found. Factors such as absent prior tissue diagnosis and/or inflammatory processes make margin diagnosis difficult. However, a high concordance was observed between our FS and PS diagnosis.

Seismic margin reviews of nuclear power plants: Identification of important functions and systems

International Nuclear Information System (INIS)

Prassinos, P.G.; Moore, D.L.; Amico, P.J.

1987-01-01

The results from the review of the seven utility-sponsored seismic PRAs plus the Zion SSMRP have been used to develop some insights regarding the importance of various systems and functions to seismic margins. By taking this information and combining it with the fragility insights we can develop some functional/systemic screening guideline for margin studies. This screening approach will greatly reduce the scope of the analysis. It is possible only to come to conclusions regarding the importance of plant systems and safety functions for PWRs, for which six plants were studied. For PWRs, it is possible to categorize plant safety functions as belonging to one of two groups, one of which is important to the assessment of seismic margins and one of which is not. The important functional group involves only two functions that must be considered for estimating seismic margin. These two functions are shutting down the nuclear reaction and providing cooling to the reactor core in the time period immediately following the seismic event (that is, the injection phase or pre-residual heat removal time period). It is possible to reasonably estimate the seismic margin of the plant by performing a study only involving the analysis of the plant systems and structure which are required in order to perform the two functions. Such analysis must include an assessment of a complete set of seismic initiating events. (orig./HP)

Deoxycholic Acid and the Marginal Mandibular Nerve: A Cadaver Study.

Science.gov (United States)

Blandford, Alexander D; Ansari, Waseem; Young, Jason M; Maley, Bruce; Plesec, Thomas P; Hwang, Catherine J; Perry, Julian D

2018-06-04

One of the rare but serious complications observed with deoxycholic acid administration is damage to the marginal mandibular nerve. In this study, we evaluated if deoxycholic acid directly induces histologic damage to fresh cadaveric marginal mandibular nerve. A segment of marginal mandibular nerve was harvested from 12 hemifaces of 6 fresh cadavers. The nerve specimen was exposed to either 0.9% sterile saline for 24 h, deoxycholic acid (10 mg/ml) for 20 min, or deoxycholic acid (10 mg/ml) for 24 h. The nerve specimens were then fixed in glutaraldehyde for a minimum of 24 h. Toluidine blue stained sections were evaluated for stain intensity using light microscopy and color deconvolution image analysis. Supraplatysmal fat was harvested as a positive control and exposed to the same treatments as the marginal mandibular nerve specimens, then evaluated using transmission electron microscopy. Toluidine blue staining was less in the marginal mandibular nerve exposed to deoxycholic acid when compared to saline. The specimen exposed to deoxycholic acid for 24 h showed less toluidine blue staining than that of the nerve exposed to deoxycholic acid for 20 min. Transmission electron microscopy of submental fat exposed to deoxycholic acid revealed disruption of adipocyte cell membrane integrity and loss of cellular organelles when compared to specimens only exposed to saline. Deoxycholic acid (10 mg/ml) damages the marginal mandibular nerve myelin sheath in fresh human cadaver specimens. Direct deoxycholic acid neurotoxicity may cause marginal mandibular nerve injury clinically. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Label-free reflectance hyperspectral imaging for tumor margin assessment: a pilot study on surgical specimens of cancer patients

Science.gov (United States)

Fei, Baowei; Lu, Guolan; Wang, Xu; Zhang, Hongzheng; Little, James V.; Patel, Mihir R.; Griffith, Christopher C.; El-Diery, Mark W.; Chen, Amy Y.

2017-08-01

A label-free, hyperspectral imaging (HSI) approach has been proposed for tumor margin assessment. HSI data, i.e., hypercube (x,y,λ), consist of a series of high-resolution images of the same field of view that are acquired at different wavelengths. Every pixel on an HSI image has an optical spectrum. In this pilot clinical study, a pipeline of a machine-learning-based quantification method for HSI data was implemented and evaluated in patient specimens. Spectral features from HSI data were used for the classification of cancer and normal tissue. Surgical tissue specimens were collected from 16 human patients who underwent head and neck (H&N) cancer surgery. HSI, autofluorescence images, and fluorescence images with 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) and proflavine were acquired from each specimen. Digitized histologic slides were examined by an H&N pathologist. The HSI and classification method were able to distinguish between cancer and normal tissue from the oral cavity with an average accuracy of 90%±8%, sensitivity of 89%±9%, and specificity of 91%±6%. For tissue specimens from the thyroid, the method achieved an average accuracy of 94%±6%, sensitivity of 94%±6%, and specificity of 95%±6%. HSI outperformed autofluorescence imaging or fluorescence imaging with vital dye (2-NBDG or proflavine). This study demonstrated the feasibility of label-free, HSI for tumor margin assessment in surgical tissue specimens of H&N cancer patients. Further development of the HSI technology is warranted for its application in image-guided surgery.

Evaluation of marginal fit of two all-ceramic copings with two finish lines

Science.gov (United States)

Subasi, Gulce; Ozturk, Nilgun; Inan, Ozgur; Bozogullari, Nalan

2012-01-01

Objectives: This in-vitro study investigated the marginal fit of two all-ceramic copings with 2 finish line designs. Methods: Forty machined stainless steel molar die models with two different margin designs (chamfer and rounded shoulder) were prepared. A total of 40 standardized copings were fabricated and divided into 4 groups (n=10 for each finish line-coping material). Coping materials tested were IPS e.max Press and Zirkonzahn; luting agent was Variolink II. Marginal fit was evaluated after cementation with a stereomicroscope (Leica MZ16). Two-way analysis of variance and Tukey-HSD test were performed to assess the influence of each finish line design and ceramic type on the marginal fit of 2 all-ceramic copings (α =.05). Results: Two-way analysis of variance revealed no statistically significant differences for marginal fit relative to finish lines (P=.362) and ceramic types (P=.065). Conclusion: Within the limitations of this study, both types of all-ceramic copings demonstrated that the mean marginal fit was considered acceptable for clinical application (⩽120 μm). PMID:22509119

Repeat CT assessed CTV variation and PTV margins for short- and long-course pre-operative RT of rectal cancer

International Nuclear Information System (INIS)

Nijkamp, Jasper; Swellengrebel, Maurits; Hollmann, Birgit; Jong, Rianne de; Marijnen, Corrie; Vliet-Vroegindeweij, Corine van; Triest, Baukelien van; Herk, Marcel van; Sonke, Jan-Jakob

2012-01-01

Purpose: To quantify the inter-fraction shape variation of the CTV in rectal-cancer patients treated with 5 × 5 (SCRT) and 25 × 2 Gy (LCRT) and derive PTV margins. Methods and materials: Thirty-three SCRT with daily repeat CT scans and 30 LCRT patients with daily scans during the first week followed by weekly scans were included. The CTV was delineated on all scans and local shape variation was calculated with respect to the planning CT. Margin estimation was done using the local shape variation to assure 95% minimum dose for at least 90% of patients. Results: Using 482 CT scans, systematic and random CTV shape variation was heterogeneous, ranging from 0.2 cm close to bony structures up to 1.0 cm SD at the upper-anterior CTV region. A significant reduction in rectal volume during LCRT resulted in an average 0.5 cm posterior shift of the upper-anterior CTV. Required margins ranged from 0.7 cm close to bony structures up to 3.1 and 2.3 cm in the upper-anterior region for SCRT and LCRT, respectively. Conclusions: Heterogeneous shape variation demands anisotropic PTV margins. Required margins were substantially larger in the anterior direction compared to current clinical margins. These larger margins were, however, based on strict delineated CTVs, resulting in smaller PTVs compared to current practice.

ASSESSMENT OF THE TSUNAMIGENIC POTENTIAL ALONG THE NORTHERN CARIBBEAN MARGIN Case Study: Earthquake and Tsunamis of 12 January 2010 in Haiti.

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George Pararas-Carayannis

2010-01-01

Full Text Available The potential tsunami risk for Hispaniola, as well as for the other Greater Antilles Islands is assessed by reviewing the complex geotectonic processes and regimes along the Northern Caribbean margin, including the convergent, compressional and collisional tectonic activity of subduction, transition, shearing, lateral movements, accretion and crustal deformation caused by the eastward movement of the Caribbean plate in relation to the North American plate. These complex tectonic interactions have created a broad, diffuse tectonic boundary that has resulted in an extensive, internal deformational sliver slab - the Gonâve microplate – as well as further segmentation into two other microplates with similarly diffused boundary characteristics where tsunamigenic earthquakes have and will again occur. The Gonâve microplate is the most prominent along the Northern Caribbean margin and extends from the Cayman Spreading Center to Mona Pass, between Puerto Rico and the island of Hispaniola, where the 1918 destructive tsunami was generated. The northern boundary of this sliver microplate is defined by the Oriente strike-slip fault south of Cuba, which appears to be an extension of the fault system traversing the northern part of Hispaniola, while the southern boundary is defined by another major strike-slip fault zone where the Haiti earthquake of 12 January 2010 occurred. Potentially tsunamigenic regions along the Northern Caribbean margin are located not only along the boundaries of the Gonâve microplate’s dominant western transform zone but particularly within the eastern tectonic regimes of the margin where subduction is dominant - particularly along the Puerto Rico trench. The Haiti earthquake of 12 January 2010 and its focal mechanism are examined, as they provide additional clues of potential tsunami generation that can occur along transform zones and, more specifically, from interplate and intraplate seismic events and subsequently induced

THE STRUCTURES OF CEREBROSPINAL FLUID IN DIAGNOSTICS AND TREATMENT EFFICACY ASSESSMENT IN PATIENT WITH NEUROSYPHILIS

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S. N. Shatokhina

2016-01-01

Full Text Available Background: In the last years, there has been an increase in cases of latent and late neurosyphilis. Due to the wide implementation of antibiotics, there is a significant reduction in sensitivity of serological and general clinical tests used for diagnosis of this disease. The situations are not uncommon when it is not possible to exclude or confirm the invasion of Treponema pallidum into the nervous system structures. Absence of objective diagnostic criteria for neurosyphilis hints the timely administration of an adequate treatment aimed at prevention of an irreversible derangement of the nervous system and to the patient death. Aim: To search for new diagnostic symptoms of an injury to the brain structures caused by Treponema pallidum in patients with previous syphilis, based on a new technology of assessment of solid phase structures of cerebrospinal fluid. Materials and methods: One hundred and thirty one patient that had been treated for various forms of syphilis were recruited to this study. In addition to generally accepted clinical and laboratory assessments, including various serological methods, all patients underwent clinical and serological assessment of cerebrospinal fluid (CSF. According to the results of this assessment, all patients were categorized into three groups. Group 1 (n=27 consisted of patients with early asymptomatic neurosyphilis, group 2 (n=46, with late meningovascular neurosyphilis, group  3 (n=58, those without diagnosed neurosyphilis but with strong positive serum tests, negative CSF serology and negative VDRL test. An innovative method of marginal dehydration of biological fluids was used. The method is included into the Lithos-system diagnostic technology and allows for evaluation of the structures of CSF systems “lipid – water”, “lipid – protein – water” after their transition from liquid crystal phase into a  solid phase. These structures called anisomorphons are seen only at polarized

Impact of Millimeter-Level Margins on Peripheral Normal Brain Sparing for Gamma Knife Radiosurgery

International Nuclear Information System (INIS)

Ma, Lijun; Sahgal, Arjun; Larson, David A.; Pinnaduwage, Dilini; Fogh, Shannon; Barani, Igor; Nakamura, Jean; McDermott, Michael; Sneed, Penny

2014-01-01

Purpose: To investigate how millimeter-level margins beyond the gross tumor volume (GTV) impact peripheral normal brain tissue sparing for Gamma Knife radiosurgery. Methods and Materials: A mathematical formula was derived to predict the peripheral isodose volume, such as the 12-Gy isodose volume, with increasing margins by millimeters. The empirical parameters of the formula were derived from a cohort of brain tumor and surgical tumor resection cavity cases (n=15) treated with the Gamma Knife Perfexion. This was done by first adding margins from 0.5 to 3.0 mm to each individual target and then creating for each expanded target a series of treatment plans of nearly identical quality as the original plan. Finally, the formula was integrated with a published logistic regression model to estimate the treatment-induced complication rate for stereotactic radiosurgery when millimeter-level margins are added. Results: Confirmatory correlation between the nominal target radius (ie, R T ) and commonly used maximum target size was found for the studied cases, except for a few outliers. The peripheral isodose volume such as the 12-Gy volume was found to increase exponentially with increasing Δ/R T , where Δ is the margin size. Such a curve fitted the data (logarithmic regression, R 2 >0.99), and the 12-Gy isodose volume was shown to increase steeply with a 0.5- to 3.0-mm margin applied to a target. For example, a 2-mm margin on average resulted in an increase of 55% ± 16% in the 12-Gy volume; this corresponded to an increase in the symptomatic necrosis rate of 6% to 25%, depending on the Δ/R T values for the target. Conclusions: Millimeter-level margins beyond the GTV significantly impact peripheral normal brain sparing and should be applied with caution. Our model provides a rapid estimate of such an effect, particularly for large and/or irregularly shaped targets

A method of accurate determination of voltage stability margin

Energy Technology Data Exchange (ETDEWEB)

Wiszniewski, A.; Rebizant, W. [Wroclaw Univ. of Technology, Wroclaw (Poland); Klimek, A. [AREVA Transmission and Distribution, Stafford (United Kingdom)

2008-07-01

In the process of developing power system disturbance, voltage instability at the receiving substations often contributes to deteriorating system stability, which eventually may lead to severe blackouts. The voltage stability margin at receiving substations may be used to determine measures to prevent voltage collapse, primarily by operating or blocking the transformer tap changing device, or by load shedding. The best measure of the stability margin is the actual load to source impedance ratio and its critical value, which is unity. This paper presented an accurate method of calculating the load to source impedance ratio, derived from the Thevenin's equivalent circuit of the system, which led to calculation of the stability margin. The paper described the calculation of the load to source impedance ratio including the supporting equations. The calculation was based on the very definition of voltage stability, which says that system stability is maintained as long as the change of power, which follows the increase of admittance is positive. The testing of the stability margin assessment method was performed in a simulative way for a number of power network structures and simulation scenarios. Results of the simulations revealed that this method is accurate and stable for all possible events occurring downstream of the device location. 3 refs., 8 figs.

Management of relapsed/refractory marginal zone lymphoma: focus on ibrutinib

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Denlinger NM

2018-03-01

Full Text Available Nathan M Denlinger, Narendranath Epperla, Basem M William Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center (OSUCCC-James, The Ohio State University, Columbus, OH, USA Abstract: Marginal zone lymphomas (MZLs consist of a diverse family of malignancies, which are derived from B-cells. The disease subtypes are recognized extranodal, nodal, and splenic MZLs. The disease characteristics, clinical course, and treatment vary considerably based on the site of involvement. In 2017, the US Food and Drug Administration approved ibrutinib, a first in class Bruton’s tyrosine kinase inhibitor that revolutionized the care of chronic lymphocytic leukemia patients; for, the treatment of relapsed/refractory MZL based on pivotal open-label Phase II trial demonstrated an overall response rate of 48%, with a complete response rate of 3%, median progression-free survival of 14.2 months, and median overall survival not yet reached at a median follow-up of 19.4 months. In this review, we aim to summarize the current conundrums in the management of MZL and the evolving role of ibrutinib in the treatment of MZL. Keywords: non-Hodgkin’s lymphoma, marginal zone, ibrutinib

Lateral view dissection of the prostato-urethral junction to reduce positive apical margin in laparoscopic radical prostatectomy.

Science.gov (United States)

Sasaki, Hiroshi; Miki, Jun; Kimura, Takahiro; Sanuki, Kunitaro; Miki, Kenta; Takahashi, Hiroyuki; Egawa, Shin

2009-08-01

To assess the impact of lateral view apical dissection in laparoscopic radical prostatectomy (LRP) on the reduction of positive surgical margin rates and recovery of postoperative continence. One hundred and forty-four consecutive patients underwent LRP from October 2004 to March 2008. Lateral view dissection of the prostato-urethral junction was conducted in 76 of them (Group 2). Standard dissection was used in the remaining patients (Group 1). The effect of this technical modification on the reduction of positive surgical margin rates and postoperative recovery of urinary continence was assessed in the two groups. Overall, the incidence of positive margins decreased from 23 (35.9%) in Group 1 to 16 cases (21.9%) in Group 2 (P = 0.07). Positive margin rates in pT2 decreased from 30.6% to 6.5% (P = 0.006). Apical and dorso-apical margins were reduced from 26.5% to 4.3% (P = 0.009) and from 10.2% to 0% (P Lateral view dissection of the prostato-urethral junction is an easily applicable technical modification. It provides better visualization of apical anatomy substantially contributing to the reduction of positive surgical margin rates, especially at the level of prostatic apex.

The interrelationship between the periodontium and the margins of artificial crowns

International Nuclear Information System (INIS)

Omar, Ridwaan

1989-01-01

Opinions have changed from the assumption that only poor restorative treatment leads to periodontal disease. Presently, it is believed that even clinically sound restorations may be an important etiological factor in the initiation of periodontal disease. The two aspects which are probably most intimately related to the supporting tissues are the manner in which the restoration establishes marginal contact with the tooth and the external contour of the restoration. In this paper, the objectives of margin placement will be reviewed; features of variously proposed designs will be compared and contrasted in the light of current materials and techniques. (author)

The Provision of Services, Interest Margins and Loan Pricing in European Banking

OpenAIRE

Lepetit , Laetitia; Nys , Emmanuelle; Rous , Philippe; Tarazi , Amine

2006-01-01

This paper assesses the implications on bank interest margins of the expansion into non- traditional fee-based activities in European banking. We use a sample of 602 European commercial and cooperative banks from 1996 to 2002 and consider the total income shares of trading income and commission and fee income as measures of product diversification to explore loan pricing. Our results show that a higher income share from commission and fee activities is associated with lower margins and lower ...

Margin improvement initiatives: realistic approaches

Energy Technology Data Exchange (ETDEWEB)

Chan, P.K.; Paquette, S. [Royal Military College of Canada, Chemistry and Chemical Engineering Dept., Kingston, ON (Canada); Cunning, T.A. [Department of National Defence, Ottawa, ON (Canada); French, C.; Bonin, H.W. [Royal Military College of Canada, Chemistry and Chemical Engineering Dept., Kingston, ON (Canada); Pandey, M. [Univ. of Waterloo, Waterloo, ON (Canada); Murchie, M. [Cameco Fuel Manufacturing, Port Hope, ON (Canada)

2014-07-01

With reactor core aging, safety margins are particularly tight. Two realistic and practical approaches are proposed here to recover margins. The first project is related to the use of a small amount of neutron absorbers in CANDU Natural Uranium (NU) fuel bundles. Preliminary results indicate that the fuelling transient and subsequent reactivity peak can be lowered to improve the reactor's operating margins, with minimal impact on burnup when less than 1000 mg of absorbers is added to a fuel bundle. The second project involves the statistical analysis of fuel manufacturing data to demonstrate safety margins. Probability distributions are fitted to actual fuel manufacturing datasets provided by Cameco Fuel Manufacturing, Inc. They are used to generate input for ELESTRES and ELOCA. It is found that the fuel response distributions are far below industrial failure limits, implying that margin exists in the current fuel design. (author)

Precessional control of Sr ratios in marginal basins during the Messinian Salinity Crisis?

Science.gov (United States)

Topper, R. P. M.; Lugli, S.; Manzi, V.; Roveri, M.; Meijer, P. Th.

2014-05-01

Based on 87Sr/86Sr data of the Primary Lower Gypsum (PLG) deposits in the Vena del Gesso basin—a marginal basin of the Mediterranean during the Messinian Salinity Crisis—a correlation between 87Sr/86Sr values and precessional forcing has recently been proposed but not yet confirmed. In this study, a box model is set up to represent the Miocene Mediterranean deep basin and a connected marginal basin. Measurements of 87Sr/86Sr in the Vena del Gesso and estimated salinity extrema are used to constrain model results. In an extensive analysis with this model, we assess whether coeval 87Sr/86Sr and salinity fluctuations could have been forced by precession-driven changes in the fresh water budget. A comprehensive set of the controlling parameters is examined to assess the conditions under which precession-driven 87Sr/86Sr variations occur and to determine the most likely setting for PLG formation. Model results show that precession-driven 87Sr/86Sr and salinity fluctuations in marginal basins are produced in settings within a large range of marginal basin sizes, riverine strontium characteristics, amplitudes of precessional fresh water budget variation, and average fresh water budgets of both the marginal and deep basin. PLG deposition most likely occurred when the Atlantic-Mediterranean connection was restricted, and the average fresh water budget in the Mediterranean was significantly less negative than at present day. Considering the large range of settings in which salinities and 87Sr/86Sr fluctuate on a precessional timescale, 87Sr/86Sr variations are expected to be a common feature in PLG deposits in marginal basins of the Mediterranean.

The marginal costs of greenhouse gas emissions

International Nuclear Information System (INIS)

Tol, R.S.J.

1999-01-01

Estimates of the marginal costs of greenhouse gas emissions are on important input to the decision how much society would want to spend on greenhouse gas emission reduction. Marginal cost estimates in the literature range between $5 and $25 per ton of carbon. Using similar assumptions, the FUND model finds marginal costs of $9--23/tC, depending on the discount rate. If the aggregation of impacts over countries accounts for inequalities in income distribution or for risk aversion, marginal costs would rise by about a factor of 3. Marginal costs per region are an order of magnitude smaller than global marginal costs. The ratios between the marginal costs of CO 2 and those of CH 4 and N 2 O are roughly equal to the global warming potentials of these gases. The uncertainty about the marginal costs is large and right-skewed. The expected value of the marginal costs lies about 35% above the best guess, the 95-percentile about 250%

Impact of respiratory-correlated CT sorting algorithms on the choice of margin definition for free-breathing lung radiotherapy treatments.

Science.gov (United States)

Thengumpallil, Sheeba; Germond, Jean-François; Bourhis, Jean; Bochud, François; Moeckli, Raphaël

2016-06-01

To investigate the impact of Toshiba phase- and amplitude-sorting algorithms on the margin strategies for free-breathing lung radiotherapy treatments in the presence of breathing variations. 4D CT of a sphere inside a dynamic thorax phantom was acquired. The 4D CT was reconstructed according to the phase- and amplitude-sorting algorithms. The phantom was moved by reproducing amplitude, frequency, and a mix of amplitude and frequency variations. Artefact analysis was performed for Mid-Ventilation and ITV-based strategies on the images reconstructed by phase- and amplitude-sorting algorithms. The target volume deviation was assessed by comparing the target volume acquired during irregular motion to the volume acquired during regular motion. The amplitude-sorting algorithm shows reduced artefacts for only amplitude variations while the phase-sorting algorithm for only frequency variations. For amplitude and frequency variations, both algorithms perform similarly. Most of the artefacts are blurring and incomplete structures. We found larger artefacts and volume differences for the Mid-Ventilation with respect to the ITV strategy, resulting in a higher relative difference of the surface distortion value which ranges between maximum 14.6% and minimum 4.1%. The amplitude- is superior to the phase-sorting algorithm in the reduction of motion artefacts for amplitude variations while phase-sorting for frequency variations. A proper choice of 4D CT sorting algorithm is important in order to reduce motion artefacts, especially if Mid-Ventilation strategy is used. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Refining margins: recent trends

International Nuclear Information System (INIS)

Baudoin, C.; Favennec, J.P.

1999-01-01

Despite a business environment that was globally mediocre due primarily to the Asian crisis and to a mild winter in the northern hemisphere, the signs of improvement noted in the refining activity in 1996 were borne out in 1997. But the situation is not yet satisfactory in this sector: the low return on invested capital and the financing of environmental protection expenditure are giving cause for concern. In 1998, the drop in crude oil prices and the concomitant fall in petroleum product prices was ultimately rather favorable to margins. Two elements tended to put a damper on this relative optimism. First of all, margins continue to be extremely volatile and, secondly, the worsening of the economic and financial crisis observed during the summer made for a sharp decline in margins in all geographic regions, especially Asia. Since the beginning of 1999, refining margins are weak and utilization rates of refining capacities have decreased. (authors)

Value of the magnetic resonance imaging in the assessment of the circumferential resection margin (CRM) in patients with rectal cancer

International Nuclear Information System (INIS)

Seehaus, A.; Fatal Jaef, V.; Pietrani, M.; Ocantos, J.

2009-01-01

Purpose: To determine whether magnetic resonance imaging (MRI) can predict tumor involvement of the circumferential resection margin (CRM) in patients with rectal cancer. Materials and methods: Between april 2005 and march 2008, 70 consecutive patients (mean age 64, range 34-78 years), 40 F and 30 M, with endoscopy and biopsy- proven middle and lower rectal cancer. Non contrast enhanced MRI was performed on a Siemens Avanto 1.5 T. A phased array coil was used and T2 weighted thin section sequences (TR/TE 4200/88, slice thickness 3mm, gap 0, matrix 256 x 256, field of view 150 x 150 mm) were performed in axial, sagittal and coronal orientations. Patients received a 150 ml glycerin enema before examination. No air insufflations or intramuscular antispasmodic was used. The shortest distance from the tumor edge to the circumferential margin was measured. A distance ≤ ?2 mm, analyzed in axial slices, was considered as definition of circumferential margin involvement. Results: The CRM was 2 mm in both MRI and histopathological findings in 26 patients. In 8 cases the CRM was shorter on MRI than in histopathological sections. In 32 patients the CRM was respected in both exams and 4 patients were considered positive on histopathological findings but negative in MRI. The sensitivity, specificity, positive and negative predictive values for prediction of tumor involvement of CRM were 86%, 80%, 76% and 88%, respectively. Conclusions: MRI gives reliable information on tumor involvement of the CRM in patients with rectal cancer. This may provide accurate identification of an important prognostic risk factor in patients prior to surgical treatment. (authors) [es

Effects of oral hygiene, residual caries and cervical Marginal-gaps on the survival of proximal atraumatic restorative treatment approach restorations

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Arthur M Kemoli

2011-01-01

Full Text Available Background: Although Atraumatic restorative treatment (ART approach has been in existence for a while, the reasons for the poor performance of multisurface ART restorations are not very clear. Aim: The aim of this study is to investigate the effects of oral hygiene, residual caries and cervical marginal-gaps on survival of proximal ART restorations. Settings: Two rural divisions in Kenya were selected for the study. Design: A randomized clinical trial. Material and Methods: The 804 children in the study had their baseline- and 2-year dental plaque levels documented. Each child received one proximal restoration in a primary molar using ART approach, together with trained and pre-tested operators/assistants, three glass ionomer cements (GIC-brands and two tooth-isolation methods. The restorations were clinically evaluated soon after placement and after 2 years. Post-restorative bite-wing radiographs taken soon after restoration were also evaluated. Statistical analysis: Statistical Package for Social Sciences (SPSS version 14 computer programme was used and results tested using Pearson′s correlation, Cox Proportional Hazards regression analysis and Multiple Logistic regression models tests. Results: At baseline and after 2 years, the mean cumulative survival and plaque index changed from 94.4% to 30.8% and 2.34 (Standard Deviation, or SD of 0.46 to 1.92 (SD 2.1 respectively, with higher plaque indices associated with higher restoration failures. Of the 507 radiographs evaluated, 48 (9.5%, 63 (12.4% and 9 (1.8% restorations had residual caries (RC, cervical marginal-gaps (CMG and both RC/CMG respectively. Survival of the restorations with RC/CMG was significantly lower (p = 0.003 compared to those with RC or without RC. Conclusion: Low survival of proximal restorations in the study was associated with the presence of cervical marginal-gaps.

Accountable Accounting: Carbon-Based Management on Marginal Lands

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Tara L. DiRocco

2014-04-01

Full Text Available Substantial discussion exists concerning the best land use options for mitigating greenhouse gas (GHG emissions on marginal land. Emissions-mitigating land use options include displacement of fossil fuels via biofuel production and afforestation. Comparing C recovery dynamics under these different options is crucial to assessing the efficacy of offset programs. In this paper, we focus on forest recovery on marginal land, and show that there is substantial inaccuracy and discrepancy in the literature concerning carbon accumulation. We find that uncertainty in carbon accumulation occurs in estimations of carbon stocks and models of carbon dynamics over time. We suggest that analyses to date have been largely unsuccessful at determining reliable trends in site recovery due to broad land use categories, a failure to consider the effect of current and post-restoration management, and problems with meta-analysis. Understanding of C recovery could be greatly improved with increased data collection on pre-restoration site quality, prior land use history, and management practices as well as increased methodological standardization. Finally, given the current and likely future uncertainty in C dynamics, we recommend carbon mitigation potential should not be the only environmental service driving land use decisions on marginal lands.

System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

Science.gov (United States)

Lawton, R. M.

1996-01-01

Demonstration of safety margins for critical points (circuits) has traditionally been required since it first became a part of systems-level Electromagnetic Compatibility (EMC) requirements of MIL-E-6051C. The goal of this document is to present cost-effective guidelines for ensuring adequate Electromagnetic Effects (EME) safety margins on spacecraft critical circuits. It is for the use of NASA and other government agencies and their contractors to prevent loss of life, loss of spacecraft, or unacceptable degradation. This document provides practical definition and treatment guidance to contain costs within affordable limits.

Margin Requirements and Equity Option Returns

DEFF Research Database (Denmark)

Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant margin premium in the cross-section of equity option returns. The sign of the margin...... premium depends on demand pressure: If end-users are on the long side of the market, option returns decrease with margins, while they increase otherwise. Our results are statistically and economically significant and robust to different margin specifications and various control variables. We explain our...... findings by a model of funding-constrained derivatives dealers that require compensation for satisfying end-users’ option demand....

Margin Requirements and Equity Option Returns

DEFF Research Database (Denmark)

Hitzemann, Steffen; Hofmann, Michael; Uhrig-Homburg, Marliese

In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant "margin premium" in the cross-section of equity option returns. The sign of the margin...... premium depends on demand pressure: If end-users are on the long side of the market, option returns decrease with margins, while they increase otherwise. Our results are statistically and economically significant and robust to different margin specifications and various control variables. We explain our...... findings by a model of funding-constrained derivatives dealers that require compensation for satisfying end-users’ option demand....

Assessment of Atraumatic Restorative Treatment (ART) on the permanent dentition in a primary care setting in Nigeria.

Science.gov (United States)

Ibiyemi, Olushola; Bankole, Olubunmi Olusola; Oke, Gbemisola Aderemi

2011-02-01

To assess the acceptability of ART and to evaluate on a longitudinal basis the survival rate of single surface occlusal ART restorations in the permanent dentition. Longitudinal Study of ART restorations. Primary Oral Health Care Setting. Aged 8-19 years in a low socioeconomic community, Southwestern Nigeria. Ninety-three ART restorations were applied on single surface occlusal caries by a dentist who had undergone training on ART. Six monthly follow-up of patients to evaluate restoration retention and marginal defect was conducted by an independent evaluator. Over 90.0% of the subjects had never undergone dental treatment, yet 63.0% perceived dental treatment as painful. After undergoing the treatment as many as 98.0% admitted that ART was not painful. On the question of their willingness to make recall visits, about 95.0% responded in the affirmative and about 96.0% reported that they would encourage others to come for treatment. The cumulative survival rate of single surface occlusal ART restorations after 2 years was 93.5% (SE=2.3%). ART was shown to be acceptable and effective in the management of single surface occlusal caries in the permanent dentition in these Nigerian children and adolescents outside the traditional clinical setting. © 2011 FDI World Dental Federation.

Decoding the Margins: What Can the Fractal Geometry of Basaltic Flow Margins Tell Us?

Science.gov (United States)

Schaefer, E. I.; Hamilton, C.; Neish, C.; Beard, S. P.; Bramson, A. M.; Sori, M.; Rader, E. L.

2016-12-01

Studying lava flows on other planetary bodies is essential to characterizing eruption styles and constraining the bodies' thermal evolution. Although planetary basaltic flows are common, many key features are not resolvable in orbital imagery. We are thus developing a technique to characterize basaltic flow type, sub-meter roughness, and sediment mantling from these data. We will present the results from upcoming fieldwork at Craters of the Moon National Monument and Preserve with FINESSE (August) and at Hawai'i Volcanoes National Park (September). We build on earlier work that showed that basaltic flow margins are approximately fractal [Bruno et al., 1992; Gaonac'h et al., 1992] and that their fractal dimensions (D) have distinct `a`ā and pāhoehoe ranges under simple conditions [Bruno et al., 1994]. Using a differential GPS rover, we have recently shown that the margin of Iceland's 2014 Holuhraun flow exhibits near-perfect (R2=0.9998) fractality for ≥24 km across dm to km scales [Schaefer et al., 2016]. This finding suggests that a fractal-based technique has significant potential to characterize flows at sub-resolution scales. We are simultaneously seeking to understand how margin fractality can be modified. A preliminary result for an `a'ā flow in Hawaii's Ka'ū Desert suggests that although aeolian mantling obscures the original flow margin, the apparent margin (i.e., sediment-lava interface) remains fractal [Schaefer et al., 2015]. Further, the apparent margin's D is likely significantly modified from that of the original margin. Other factors that we are exploring include erosion, transitional flow types, and topographic confinement. We will also rigorously test the intriguing possibility that margin D correlates with the sub-meter Hurst exponent H of the flow surface, a common metric of roughness scaling [e.g., Shepard et al., 2001]. This hypothesis is based on geometric arguments [Turcotte, 1997] and is qualitatively consistent with all results so far.

In vitro analysis of the marginal adaptation and discrepancy of stainless steel crowns

Science.gov (United States)

Mulder, Riaan; Medhat, Rasha; Mohamed, Nadia

2018-01-01

Abstract Aim: The purpose of the study was to assess the marginal adaptation and discrepancy of SSC’s. Differences in adaptation and discrepancy between the four surfaces (mesial, lingual, distal, and buccal) were evaluated. Methods: The placement of stainless steel crowns were completed on a phantom head in accordance with the clinical technique. The ideal tooth preparation was made and this ‘master tooth’ duplicated to achieve a sample size of 15. The stainless steel crowns were placed, trimmed, and cemented as per the clinical technique. The cemented stainless crowns were analyzed under 100× stereomicroscope magnification. The marginal adaptation and discrepancy of each specimen was measured every 2 µm. Results: All the specimens showed marginal adaptation and discrepancy. The lingual margin had a significantly better adaptation (p steel crown adaptation and discrepancy is an essential clinical step. PMID:29536024

Toward a more rigorous application of margins and uncertainties within the nuclear weapons life cycle : a Sandia perspective

International Nuclear Information System (INIS)

Klenke, Scott Edward; Novotny, George Charles; Paulsen Robert A., Jr.; Diegert, Kathleen V.; Trucano, Timothy Guy; Pilch, Martin M.

2007-01-01

This paper presents the conceptual framework that is being used to define quantification of margins and uncertainties (QMU) for application in the nuclear weapons (NW) work conducted at Sandia National Laboratories. The conceptual framework addresses the margins and uncertainties throughout the NW life cycle and includes the definition of terms related to QMU and to figures of merit. Potential applications of QMU consist of analyses based on physical data and on modeling and simulation. Appendix A provides general guidelines for addressing cases in which significant and relevant physical data are available for QMU analysis. Appendix B gives the specific guidance that was used to conduct QMU analyses in cycle 12 of the annual assessment process. Appendix C offers general guidelines for addressing cases in which appropriate models are available for use in QMU analysis. Appendix D contains an example that highlights the consequences of different treatments of uncertainty in model-based QMU analyses

A method to select aperture margin in collimated spot scanning proton therapy

International Nuclear Information System (INIS)

Wang, Dongxu; Smith, Blake R; Gelover, Edgar; Flynn, Ryan T; Hyer, Daniel E

2015-01-01

The use of collimator or aperture may sharpen the lateral dose gradient for spot scanning proton therapy. However, to date, there has not been a standard method to determine the aperture margin for a single field in collimated spot scanning proton therapy. This study describes a theoretical framework to select the optimal aperture margin for a single field, and also presents the spot spacing limit required such that the optimal aperture margin exists. Since, for a proton pencil beam partially intercepted by collimator, the maximum point dose (spot center) shifts away from the original pencil beam central axis, we propose that the optimal margin should be equal to the maximum pencil beam center shift under the condition that spot spacing is small with respect to the maximum pencil beam center shift, which can be numerically determined based on beam modeling data. A test case is presented which demonstrates agreement with the prediction made based on the proposed methods. When apertures are applied in a commercial treatment planning system this method may be implemented. (note)

Intrafraction Prostate Translations and Rotations During Hypofractionated Robotic Radiation Surgery: Dosimetric Impact of Correction Strategies and Margins

Energy Technology Data Exchange (ETDEWEB)

Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Valli, Lorella [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Alma Mater Studiorum, Department of Physics and Astronomy, Bologna University, Bologna (Italy); Aluwini, Shafak [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands); Lanconelli, Nico [Alma Mater Studiorum, Department of Physics and Astronomy, Bologna University, Bologna (Italy); Heijmen, Ben; Hoogeman, Mischa [Erasmus MC Cancer Institute, Department of Radiation Oncology, Rotterdam (Netherlands)

2014-04-01

Purpose: To investigate the dosimetric impact of intrafraction prostate motion and the effect of robot correction strategies for hypofractionated CyberKnife treatments with a simultaneously integrated boost. Methods and Materials: A total of 548 real-time prostate motion tracks from 17 patients were available for dosimetric simulations of CyberKnife treatments, in which various correction strategies were included. Fixed time intervals between imaging/correction (15, 60, 180, and 360 seconds) were simulated, as well as adaptive timing (ie, the time interval reduced from 60 to 15 seconds in case prostate motion exceeded 3 mm or 2° in consecutive images). The simulated extent of robot corrections was also varied: no corrections, translational corrections only, and translational corrections combined with rotational corrections up to 5°, 10°, and perfect rotational correction. The correction strategies were evaluated for treatment plans with a 0-mm or 3-mm margin around the clinical target volume (CTV). We recorded CTV coverage (V{sub 100%}) and dose-volume parameters of the peripheral zone (boost), rectum, bladder, and urethra. Results: Planned dose parameters were increasingly preserved with larger extents of robot corrections. A time interval between corrections of 60 to 180 seconds provided optimal preservation of CTV coverage. To achieve 98% CTV coverage in 98% of the treatments, translational and rotational corrections up to 10° were required for the 0-mm margin plans, whereas translational and rotational corrections up to 5° were required for the 3-mm margin plans. Rectum and bladder were spared considerably better in the 0-mm margin plans. Adaptive timing did not improve delivered dose. Conclusions: Intrafraction prostate motion substantially affected the delivered dose but was compensated for effectively by robot corrections using a time interval of 60 to 180 seconds. A 0-mm margin required larger extents of additional rotational corrections than a 3

Intrafraction Prostate Translations and Rotations During Hypofractionated Robotic Radiation Surgery: Dosimetric Impact of Correction Strategies and Margins

International Nuclear Information System (INIS)

Water, Steven van de; Valli, Lorella; Aluwini, Shafak; Lanconelli, Nico; Heijmen, Ben; Hoogeman, Mischa

2014-01-01

Purpose: To investigate the dosimetric impact of intrafraction prostate motion and the effect of robot correction strategies for hypofractionated CyberKnife treatments with a simultaneously integrated boost. Methods and Materials: A total of 548 real-time prostate motion tracks from 17 patients were available for dosimetric simulations of CyberKnife treatments, in which various correction strategies were included. Fixed time intervals between imaging/correction (15, 60, 180, and 360 seconds) were simulated, as well as adaptive timing (ie, the time interval reduced from 60 to 15 seconds in case prostate motion exceeded 3 mm or 2° in consecutive images). The simulated extent of robot corrections was also varied: no corrections, translational corrections only, and translational corrections combined with rotational corrections up to 5°, 10°, and perfect rotational correction. The correction strategies were evaluated for treatment plans with a 0-mm or 3-mm margin around the clinical target volume (CTV). We recorded CTV coverage (V 100% ) and dose-volume parameters of the peripheral zone (boost), rectum, bladder, and urethra. Results: Planned dose parameters were increasingly preserved with larger extents of robot corrections. A time interval between corrections of 60 to 180 seconds provided optimal preservation of CTV coverage. To achieve 98% CTV coverage in 98% of the treatments, translational and rotational corrections up to 10° were required for the 0-mm margin plans, whereas translational and rotational corrections up to 5° were required for the 3-mm margin plans. Rectum and bladder were spared considerably better in the 0-mm margin plans. Adaptive timing did not improve delivered dose. Conclusions: Intrafraction prostate motion substantially affected the delivered dose but was compensated for effectively by robot corrections using a time interval of 60 to 180 seconds. A 0-mm margin required larger extents of additional rotational corrections than a 3-mm

TU-AB-303-06: Does Online Adaptive Radiation Therapy Mean Zero Margin for Intermediate-Risk Prostate Cancer? An Intra-Fractional Seminal Vesicles Motion Analysis

Energy Technology Data Exchange (ETDEWEB)

Sheng, Y; Li, T; Lee, W; Yin, F; Wu, Q [Duke University Medical Center, Durham, NC (United States)

2015-06-15

Purpose: To provide benchmark for seminal vesicles (SVs) margin selection to account for intra-fractional motion; and to investigate the effectiveness of two motion surrogates in predicting intra-fractional SV underdosage. Methods: 9 prostate SBRT patients were studied; each has five pairs of pre-treatment and post-treatment cone-beam CTs (CBCTs). Each pair of CBCTs was registered based on fiducial markers in the prostate. To provide “ground truth” for coverage evaluation, all pre-treatment SVs were expanded with isotropic margin of 1,2,3,5 and 8mm, and their overlap with post-treatment SVs were used to quantify intra-fractional coverage. Two commonly used motion surrogates, the center-of-mass (COM) and the border of contour (the most distal points in SI/AP/LR directions) were evaluated using Receiver-Operating Characteristic (ROC) analyses for predicting SV underdosage due to intra-fractional motion. Action threshold of determining underdosage for each surrogate was calculated by selecting the optimal balancing between sensitivity and specificity. For comparison, margin for each surrogate was also calculated based on traditional margin recipe. Results: 90% post-treatment SV coverage can be achieved in 47%, 82%, 91%, 98% and 98% fractions for 1,2,3,5 and 8mm margins. 3mm margin ensured the 90% intra-fractional SV coverage in 90% fractions when prostate was aligned. The ROC analysis indicated the AUC for COM and border were 0.88 and 0.72. The underdosage threshold was 2.9mm for COM and 4.1mm for border. The Van Herk’s margin recipe recommended 0.5, 0 and 1.8mm margin in LR, AP and SI direction based on COM and for border, the corresponding margin was 2.1, 4.5 and 3mm. Conclusion: 3mm isotropic margin is the minimum required to mitigate the intra-fractional SV motion when prostate is aligned. ROC analysis reveals that both COM and border are acceptable predictors for SV underdosage with 2.9mm and 4.1mm action threshold. Traditional margin calculation is less

TU-AB-303-06: Does Online Adaptive Radiation Therapy Mean Zero Margin for Intermediate-Risk Prostate Cancer? An Intra-Fractional Seminal Vesicles Motion Analysis

International Nuclear Information System (INIS)

Sheng, Y; Li, T; Lee, W; Yin, F; Wu, Q

2015-01-01

Purpose: To provide benchmark for seminal vesicles (SVs) margin selection to account for intra-fractional motion; and to investigate the effectiveness of two motion surrogates in predicting intra-fractional SV underdosage. Methods: 9 prostate SBRT patients were studied; each has five pairs of pre-treatment and post-treatment cone-beam CTs (CBCTs). Each pair of CBCTs was registered based on fiducial markers in the prostate. To provide “ground truth” for coverage evaluation, all pre-treatment SVs were expanded with isotropic margin of 1,2,3,5 and 8mm, and their overlap with post-treatment SVs were used to quantify intra-fractional coverage. Two commonly used motion surrogates, the center-of-mass (COM) and the border of contour (the most distal points in SI/AP/LR directions) were evaluated using Receiver-Operating Characteristic (ROC) analyses for predicting SV underdosage due to intra-fractional motion. Action threshold of determining underdosage for each surrogate was calculated by selecting the optimal balancing between sensitivity and specificity. For comparison, margin for each surrogate was also calculated based on traditional margin recipe. Results: 90% post-treatment SV coverage can be achieved in 47%, 82%, 91%, 98% and 98% fractions for 1,2,3,5 and 8mm margins. 3mm margin ensured the 90% intra-fractional SV coverage in 90% fractions when prostate was aligned. The ROC analysis indicated the AUC for COM and border were 0.88 and 0.72. The underdosage threshold was 2.9mm for COM and 4.1mm for border. The Van Herk’s margin recipe recommended 0.5, 0 and 1.8mm margin in LR, AP and SI direction based on COM and for border, the corresponding margin was 2.1, 4.5 and 3mm. Conclusion: 3mm isotropic margin is the minimum required to mitigate the intra-fractional SV motion when prostate is aligned. ROC analysis reveals that both COM and border are acceptable predictors for SV underdosage with 2.9mm and 4.1mm action threshold. Traditional margin calculation is less

Influence of artificial aging in marginal adaptation of mixed class V cavities.

Science.gov (United States)

Tonetto, Mateus Rodrigues; Bandéca, Matheus Coelho; Barud, Hélida Gomes de Oliveira; Pinto, Shelon Cristina Souza; Lima, Darlon Martins; Borges, Alvaro Henrique; de Campos, Edson Alves; de Andrade, Marcelo Ferrarezi

2013-03-01

The aim of this study was to investigate whether the artificial aging by thermal cycling had influenced the marginal adaptation of class V restorations with/without chlorhexidine application in the bond process. Twelve intact human third molars were used. Class V cavity preparations were performed on the buccal surface and the teeth received 35% phosphoric acid-etching procedure (Ultradent Products Inc., South Jordan, Utah, USA). Subsequently, the samples were divided in two groups: Untreated acid-etched dentin and chlorhexidine application as an adjunct in the bond process. The adhesive Single Bond 2 (3M ESPE, St. Paul, MN, USA) was used after 2% chlorhexidine application, and the restorations were performed with Filtek™ Z350 XT (3M ESPE) composite resin. The specimens were submitted to artificial aging by thermal cycling with 3,000 cycles. Analyzes were performed on scanning electron microscopy using replicas of marginal adaptation in percentage of continuous margin before and after the artificial aging. The data were analyzed by paired test and the results showed statistically significant differences in the percentage of continuous margin with/without chlorhexidine treatment before and after thermal cycling. This study concluded that the artificial aging by thermal cycling influenced the marginal adaptation of mixed class V composite restorations.

Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

Science.gov (United States)

van den Brand, Michiel; van Krieken, J. Han J.M.

2013-01-01

The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity. PMID:23813646

Daily Online Cone Beam Computed Tomography to Assess Interfractional Motion in Patients With Intact Cervical Cancer

International Nuclear Information System (INIS)

Tyagi, Neelam; Lewis, John H.; Yashar, Catheryn M.; Vo, Daniel; Jiang, Steve B.; Mundt, Arno J.; Mell, Loren K.

2011-01-01

Purpose: To quantify interfraction motion in patients with intact cervical cancer and assess implications for clinical target volume (CTV) coverage and required planning margins. Methods and Materials: We analyzed 10 patients undergoing external beam radiotherapy using online cone beam computed tomography (CBCT) before each fraction. CTVs were contoured on the planning CT and on each CBCT. Each CBCT was rigidly registered to the planning CT with respect to bony anatomy. The CTV from each CBCT was projected onto the planning CT and compared to the CTV from the planning CT. Uniform three-dimensional expansions were applied to the planning CTV to assess required planning margins. For each fraction, the minimum margin required to encompass the CTV was calculated, and the volume of CTV (on the CBCT) encompassed by the PTV was determined as a function of margin size. Results: A uniform CTV planning treatment volume margin of 15 mm would have failed to encompass the CTV in 32% of fractions. The mean volume of CTV missed, however, was small (4 cc). The mean planning margin (across patients and fractions) required to encompass the CTV was 15 mm. Variation in margin estimates was high, with interpatient variation being the predominant component. Increased rectal volume was associated with posterior (p < 0.0001) and superior (p = 0.0004) shifts in the CTV, whereas increased bladder volume was associated with superior shifts (p < 0.0001). Conclusions: Interfraction motion results in a high probability of missing the CTV using conventional planning margins, but the volume of CTV missed is small. Adaptive radiotherapy approaches are needed to improve treatment accuracy.

Splenic marginal zone lymphoma.

Science.gov (United States)

Piris, Miguel A; Onaindía, Arantza; Mollejo, Manuela

Splenic marginal zone lymphoma (SMZL) is an indolent small B-cell lymphoma involving the spleen and bone marrow characterized by a micronodular tumoral infiltration that replaces the preexisting lymphoid follicles and shows marginal zone differentiation as a distinctive finding. SMZL cases are characterized by prominent splenomegaly and bone marrow and peripheral blood infiltration. Cells in peripheral blood show a villous cytology. Bone marrow and peripheral blood characteristic features usually allow a diagnosis of SMZL to be performed. Mutational spectrum of SMZL identifies specific findings, such as 7q loss and NOTCH2 and KLF2 mutations, both genes related with marginal zone differentiation. There is a striking clinical variability in SMZL cases, dependent of the tumoral load and performance status. Specific molecular markers such as 7q loss, p53 loss/mutation, NOTCH2 and KLF2 mutations have been found to be associated with the clinical variability. Distinction from Monoclonal B-cell lymphocytosis with marginal zone phenotype is still an open issue that requires identification of precise and specific thresholds with clinical meaning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Categorical marginal models: quite extensive package for the estimation of marginal models for categorical data

OpenAIRE

Wicher Bergsma; Andries van der Ark

2015-01-01

A package accompanying the book Marginal Models for Dependent, Clustered, and Longitudinal Categorical Data by Bergsma, Croon, & Hagenaars, 2009. It’s purpose is fitting and testing of marginal models.

Characterizing Convexity of Games using Marginal Vectors

NARCIS (Netherlands)

van Velzen, S.; Hamers, H.J.M.; Norde, H.W.

2003-01-01

In this paper we study the relation between convexity of TU games and marginal vectors.We show that if specfic marginal vectors are core elements, then the game is convex.We characterize sets of marginal vectors satisfying this property, and we derive the formula for the minimum number of marginal

Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

International Nuclear Information System (INIS)

Chen, Wan-Yu; Kuo, Sung-Hsin; Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling; Chia-Hsien Cheng, Jason; Hong, Ruey-Long; Chen, Ya-Fang; Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping; Chong, Fok-Ching; Wang, Chun-Wei

2012-01-01

Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6–33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

Postoperative Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the External Auditory Canal and Middle Ear: Treatment Outcomes, Marginal Misses, and Perspective on Target Delineation

Energy Technology Data Exchange (ETDEWEB)

Chen, Wan-Yu [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Kuo, Sung-Hsin [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Chen, Yu-Hsuan; Lu, Szu-Huai; Tsai, Chiao-Ling [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chia-Hsien Cheng, Jason [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan (China); Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan (China); Hong, Ruey-Long [Division of Medical Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Ya-Fang [Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan (China); Hsu, Chuan-Jen; Lin, Kai-Nan; Ko, Jenq-Yuh; Lou, Pei-Jen; Wang, Cheng-Ping [Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan (China); Chong, Fok-Ching [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Wang, Chun-Wei, E-mail: cwwang@ntuh.gov.tw [Graduate Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

2012-03-15

Purpose: To report outcomes of the rare disease of squamous cell carcinoma (SCC) of the external auditory canal (EAC) and middle ear treated with surgery and postoperative intensity-modulated radiotherapy (IMRT). Failure patterns related to spatial dose distribution were also analyzed to provide insight into target delineation. Methods and Materials: A retrospective review was conducted of the records of 11 consecutive patients with SCC of the EAC and middle ear who were treated with curative surgery and postoperative IMRT at one institution between January 2007 and February 2010. The prescribed IMRT dose was 60 to 66 Gy at 2 Gy per fraction. Three patients also received concurrent cisplatin-based chemotherapy, and 1 patient received concurrent oral tegafur/uracil. The median follow-up time was 19 months (range, 6-33 months). Results: Four patients had locoregional recurrence, yielding an estimated 2-year locoregional control rate of 70.7%. Among them, 1 patient had persistent disease after treatment, and 3 had marginal recurrence. Distant metastasis occurred in 1 patient after extensive locoregional recurrence, yielding an estimated 2-year distant control rate of 85.7%. The estimated 2-year overall survival was 67.5%. The three cases of marginal recurrence were near the preauricular space and glenoid fossa of the temporomandibular joint, adjacent to the apex of the ear canal and glenoid fossa of the temporomandibular joint, and in the postauricular subcutaneous area and ipsilateral parotid nodes, respectively. Conclusions: Marginal misses should be recognized to improve target delineation. When treating SCC of the EAC and middle ear, care should be taken to cover the glenoid fossa of the temporomandibular joint and periauricular soft tissue. Elective ipsilateral parotid irradiation should be considered. The treatment planning procedure should also be refined to balance subcutaneous soft-tissue dosimetry and toxicity.

Treatment response assessment of radiofrequency ablation for hepatocellular carcinoma: Usefulness of virtual CT sonography with magnetic navigation

International Nuclear Information System (INIS)

Minami, Yasunori; Kitai, Satoshi; Kudo, Masatoshi

2012-01-01

Purpose: Virtual CT sonography using magnetic navigation provides cross sectional images of CT volume data corresponding to the angle of the transducer in the magnetic field in real-time. The purpose of this study was to clarify the value of this virtual CT sonography for treatment response of radiofrequency ablation for hepatocellular carcinoma. Patients and methods: Sixty-one patients with 88 HCCs measuring 0.5–1.3 cm (mean ± SD, 1.0 ± 0.3 cm) were treated by radiofrequency ablation. For early treatment response, dynamic CT was performed 1–5 days (median, 2 days). We compared early treatment response between axial CT images and multi-angle CT images using virtual CT sonography. Results: Residual tumor stains on axial CT images and multi-angle CT images were detected in 11.4% (10/88) and 13.6% (12/88) after the first session of RFA, respectively (P = 0.65). Two patients were diagnosed as showing hyperemia enhancement after the initial radiofrequency ablation on axial CT images and showed local tumor progression shortly because of unnoticed residual tumors. Only virtual CT sonography with magnetic navigation retrospectively showed the residual tumor as circular enhancement. In safety margin analysis, 10 patients were excluded because of residual tumors. The safety margin more than 5 mm by virtual CT sonographic images and transverse CT images were determined in 71.8% (56/78) and 82.1% (64/78), respectively (P = 0.13). The safety margin should be overestimated on axial CT images in 8 nodules. Conclusion: Virtual CT sonography with magnetic navigation was useful in evaluating the treatment response of radiofrequency ablation therapy for hepatocellular carcinoma.

Quantifying motion for pancreatic radiotherapy margin calculation

International Nuclear Information System (INIS)

Whitfield, Gillian; Jain, Pooja; Green, Melanie; Watkins, Gillian; Henry, Ann; Stratford, Julie; Amer, Ali; Marchant, Thomas; Moore, Christopher; Price, Patricia

2012-01-01

Background and purpose: Pancreatic radiotherapy (RT) is limited by uncertain target motion. We quantified 3D patient/organ motion during pancreatic RT and calculated required treatment margins. Materials and methods: Cone-beam computed tomography (CBCT) and orthogonal fluoroscopy images were acquired post-RT delivery from 13 patients with locally advanced pancreatic cancer. Bony setup errors were calculated from CBCT. Inter- and intra-fraction fiducial (clip/seed/stent) motion was determined from CBCT projections and orthogonal fluoroscopy. Results: Using an off-line CBCT correction protocol, systematic (random) setup errors were 2.4 (3.2), 2.0 (1.7) and 3.2 (3.6) mm laterally (left–right), vertically (anterior–posterior) and longitudinally (cranio-caudal), respectively. Fiducial motion varied substantially. Random inter-fractional changes in mean fiducial position were 2.0, 1.6 and 2.6 mm; 95% of intra-fractional peak-to-peak fiducial motion was up to 6.7, 10.1 and 20.6 mm, respectively. Calculated clinical to planning target volume (CTV–PTV) margins were 1.4 cm laterally, 1.4 cm vertically and 3.0 cm longitudinally for 3D conformal RT, reduced to 0.9, 1.0 and 1.8 cm, respectively, if using 4D planning and online setup correction. Conclusions: Commonly used CTV–PTV margins may inadequately account for target motion during pancreatic RT. Our results indicate better immobilisation, individualised allowance for respiratory motion, online setup error correction and 4D planning would improve targeting.

12 CFR 220.4 - Margin account.

Science.gov (United States)

2010-01-01

... Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM CREDIT BY... securities. The required margin on a net long or net short commitment in a when-issued security is the margin...) Interest charged on credit maintained in the margin account; (ii) Premiums on securities borrowed in...

Mean Field Theory, Ginzburg Criterion, and Marginal Dimensionality of Phase-Transitions

DEFF Research Database (Denmark)

Als-Nielsen, Jens Aage; Birgenau, R. J.

1977-01-01

By applying a real space version of the Ginzburg criterion, the role of fluctuations and thence the self‐consistency of mean field theory are assessed in a simple fashion for a variety of phase transitions. It is shown that in using this approach the concept of ’’marginal dimensionality’’ emerges...... in a natural way. For example, it is shown that for many homogeneous structural transformations the marginal dimensionality is two, so that mean field theory will be valid for real three‐dimensional systems. It is suggested that this simple self‐consistent approach to Landau theory should be incorporated...

Conference Report: The New Discovery of Margins: Theory-Based Excursions in Marginal Social Fields

Directory of Open Access Journals (Sweden)

Babette Kirchner

2014-05-01

Full Text Available At this year's spring conference of the Sociology of Knowledge Section of the German Sociological Association, a diverse range of theoretical concepts and multiple empirical insights into different marginal social fields were presented. As in everyday life, drawing a line between center and margin can be seen as an important challenge that must equally be faced in sociology. The socially constructed borderline appears to be highly variable. Therefore it has to be delineated or fixed somehow. The construction of margins is necessary for society in general and smaller social groupings alike to confirm one's own "normal" identity, or one's own membership on the fringes. The different contributions exemplify what was established at the beginning of the conference: Namely that society and its margins are defined differently according to the empirical as well as conceptual focus. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1402148

Planning target volumes for radiotherapy: how much margin is needed?

International Nuclear Information System (INIS)

Antolak, John A.; Rosen, Isaac I.

1999-01-01

Purpose: The radiotherapy planning target volume (PTV) encloses the clinical target volume (CTV) with anisotropic margins to account for possible uncertainties in beam alignment, patient positioning, organ motion, and organ deformation. Ideally, the CTV-PTV margin should be determined solely by the magnitudes of the uncertainties involved. In practice, the clinician usually also considers doses to abutting healthy tissues when deciding on the size of the CTV-PTV margin. This study calculates the ideal size of the CTV-PTV margin when only physical position uncertainties are considered. Methods and Materials: The position of the CTV for any treatment is assumed to be described by independent Gaussian distributions in each of the three Cartesian directions. Three strategies for choosing a CTV-PTV margin are analyzed. The CTV-PTV margin can be based on: 1. the probability that the CTV is completely enclosed by the PTV; 2. the probability that the projection of the CTV in the beam's eye view (BEV) is completely enclosed by the projection of the PTV in the BEV; and 3. the probability that a point on the edge of the CTV is within the PTV. Cumulative probability distributions are derived for each of the above strategies. Results: Expansion of the CTV by 1 standard deviation (SD) in each direction results in the CTV being entirely enclosed within the PTV 24% of the time; the BEV projection of the CTV is enclosed within the BEV projection of the PTV 39% of the time; and a point on the edge of the CTV is within the PTV 84% of the time. To have the CTV enclosed entirely within the PTV 95% of the time requires a margin of 2.8 SD. For the BEV projection of the CTV to be within the BEV projection of the PTV 95% of the time requires a margin of 2.45 SD. To have any point on the surface of the CTV be within the PTV 95% of the time requires a margin of 1.65 SD. Conclusion: In the first two strategies for selecting a margin, the probability of finding the CTV within the PTV is

Comparison of safety margins for leak-before-break assessment of 500 MWe PHWR straight pipes: using contemporary techniques

International Nuclear Information System (INIS)

Rastogi, Rohit; Bhasin, Vivek; Kushwaha, H.S.

1998-01-01

The Leak Before Break (LBB) analysis of Primary Heat Transport (PHT) Piping of 500 MWe Indian PHWR is being performed using different well established techniques like R6 method (Nuclear Electric UK) and J-Tearing based methods (USNRC). These methods show that PHT piping has required safety margins and can be qualified for LBB. These analysis also showed that the piping has high fracture toughness and plastic collapse is the dominant mode of failure. To enhance the confidence in the results obtained from the above methods, further studies were done on the PHT piping. Procedures which predicted margins against plastic collapse were used. The analysis procedures used were Modified Limit Load Method, MPA Method (both from Germany), Moments Method (from Italy) and the Z-Factor method given in ASME Boiler and Pressure Vessel Code. The safety margins obtained from these analysis satisfied the LBB requirements. A table was generated which compared the safety margins obtained using all the above mentioned procedures. This report presents the results of this study. (author)

Does insecticide drift adversely affect grasshoppers (Orthoptera: Saltatoria) in field margins? A case study combining laboratory acute toxicity testing with field monitoring data.

Science.gov (United States)

Bundschuh, Rebecca; Schmitz, Juliane; Bundschuh, Mirco; Brühl, Carsten Albrecht

2012-08-01

The current terrestrial risk assessment of insecticides regarding nontarget arthropods considers exclusively beneficial organisms, whereas herbivorous insects, such as grasshoppers, are ignored. However, grasshoppers living in field margins or meadows adjacent to crops may potentially be exposed to insecticides due to contact with or ingestion of contaminated food. Therefore, the present study assessed effects of five active ingredients of insecticides (dimethoate, pirimicarb, imidacloprid, lambda-cyhalothrin, and deltamethrin) on the survival of Chorthippus sp. grasshopper nymphs by considering two routes of exposure (contact and oral). The experiments were accompanied by monitoring field margins that neighbored cereals, vineyards, and orchards. Grasslands were used as reference sites. The laboratory toxicity tests revealed a sensitivity of grasshoppers with regard to the insecticides tested in the present study similar to that of the standard test species used in arthropod risk assessments. In the field monitoring program, increasing grasshopper densities were detected with increasing field margin width next to cereals and vineyards, but densities remained low over the whole range of field margins from 0.5 to 20 m next to orchards. Grasshopper densities equivalent to those of grassland sites were only observed in field margins exceeding 9 m in width, except for field margins next to orchards. These results may indicate that current insecticide risk assessments are insufficiently protective for grasshoppers in field margins. Copyright © 2012 SETAC.

Transformation of marginal zone lymphoma (and association with other lymphomas).

Science.gov (United States)

Casulo, Carla; Friedberg, Jonathan

Marginal zone lymphomas (MZL) are a diverse group of indolent lymphoproliferative disorders that comprise three subtypes: nodal, splenic and mucosal associated marginal zone lymphomas (MALT). Histologic transformation (HT) to an aggressive lymphoma is a rare event that can occur in any subtype, and at lower frequency compared to other indolent non Hodgkin lymphomas (NHL) like follicular lymphoma. There are few data directly associated with risk and prognosis of transformation in MZL. However, recent advances in the understanding of molecular and genetic features of MALT have contributed to an evolving appreciation of HT in this disease. Optimal treatment of HT of MZL remains unknown. Much of the approach to managing transformed MZL is extrapolated from other indolent NHLs. Copyright © 2016 Elsevier Ltd. All rights reserved.

SU-F-J-17: Patient Localization Using MRI-Guided Soft Tissue for Head-And-Neck Radiotherapy: Indication for Margin Reduction and Its Feasibility

International Nuclear Information System (INIS)

Qi, X; Yang, Y; Jack, N; Santhanam, A; Yang, L; Chen, A; Low, D

2016-01-01

Purpose: On-board MRI provides superior soft-tissue contrast, allowing patient alignment using tumor or nearby critical structures. This study aims to study H&N MRI-guided IGRT to analyze inter-fraction patient setup variations using soft-tissue targets and design appropriate CTV-to-PTV margin and clinical implication. Methods: 282 MR images for 10 H&N IMRT patients treated on a ViewRay system were retrospectively analyzed. Patients were immobilized using a thermoplastic mask on a customized headrest fitted in a radiofrequency coil and positioned to soft-tissue targets. The inter-fraction patient displacements were recorded to compute the PTV margins using the recipe: 2.5∑+0.7σ. New IMRT plans optimized on the revised PTVs were generated to evaluate the delivered dose distributions. An in-house dose deformation registration tool was used to assess the resulting dosimetric consequences when margin adaption is performed based on weekly MR images. The cumulative doses were compared to the reduced margin plans for targets and critical structures. Results: The inter-fraction displacements (and standard deviations), ∑ and σ were tabulated for MRI and compared to kVCBCT. The computed CTV-to-PTV margin was 3.5mm for soft-tissue based registration. There were minimal differences between the planned and delivered doses when comparing clinical and the PTV reduced margin plans: the paired t-tests yielded p=0.38 and 0.66 between the planned and delivered doses for the adapted margin plans for the maximum cord and mean parotid dose, respectively. Target V95 received comparable doses as planned for the reduced margin plans. Conclusion: The 0.35T MRI offers acceptable soft-tissue contrast and good spatial resolution for patient alignment and target visualization. Better tumor conspicuity from MRI allows soft-tissue based alignments with potentially improved accuracy, suggesting a benefit of margin reduction for H&N radiotherapy. The reduced margin plans (i.e., 2 mm) resulted

The marginal band system in nymphalid butterfly wings.

Science.gov (United States)

Taira, Wataru; Kinjo, Seira; Otaki, Joji M

2015-01-01

Butterfly wing color patterns are highly complex and diverse, but they are believed to be derived from the nymphalid groundplan, which is composed of several color pattern systems. Among these pattern systems, the marginal band system, including marginal and submarginal bands, has rarely been studied. Here, we examined the color pattern diversity of the marginal band system among nymphalid butterflies. Marginal and submarginal bands are usually expressed as a pair of linear bands aligned with the wing margin. However, a submarginal band can be expressed as a broken band, an elongated oval, or a single dot. The marginal focus, usually a white dot at the middle of a wing compartment along the wing edge, corresponds to the pupal edge spot, one of the pupal cuticle spots that signify the locations of color pattern organizing centers. A marginal band can be expressed as a semicircle, an elongated oval, or a pair of eyespot-like structures, which suggest the organizing activity of the marginal focus. Physical damage at the pupal edge spot leads to distal dislocation of the submarginal band in Junonia almana and in Vanessa indica, suggesting that the marginal focus functions as an organizing center for the marginal band system. Taken together, we conclude that the marginal band system is developmentally equivalent to other symmetry systems. Additionally, the marginal band is likely a core element and the submarginal band a paracore element of the marginal band system, and both bands are primarily specified by the marginal focus organizing center.

MARGINS: Toward a novel science plan

Science.gov (United States)

Mutter, John C.

A science plan to study continental margins has been in the works for the past 3 years, with almost 200 Earth scientists from a wide variety of disciplines gathering at meetings and workshops. Most geological hazards and resources are found at continental margins, yet our understanding of the processes that shape the margins is meager.In formulating this MARGINS research initiative, fundamental issues concerning our understanding of basic Earth-forming processes have arisen. It is clear that a business-as-usual approach will not solve the class of problems defined by the MARGINS program; the solutions demand approaches different from those used in the past. In many cases, a different class of experiment will be required, one that is well beyond the capability of individual principle investigators to undertake on their own. In most cases, broadly based interdisciplinary studies will be needed.

Evaluation and comparison of the marginal adaptation of two different substructure materials.

Science.gov (United States)

Karaman, Tahir; Ulku, Sabiha Zelal; Zengingul, Ali Ihsan; Guven, Sedat; Eratilla, Veysel; Sumer, Ebru

2015-06-01

In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, 24.47 ± 5.82 µm before and 35.11 ± 6.52 µm after cementation; in the laser-sintered Co-Cr structure, it was, on average, 60.45 ± 8.87 µm before and 69.33 ± 9.03 µm after cementation. A highly significant difference (Pcementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.

Conducting Systematic Outcome Assessment in Private Addictions Treatment Settings

Directory of Open Access Journals (Sweden)

Gerard J Connors

2017-07-01

Full Text Available Systematic outcome assessment is central to ascertaining the impact of treatment services and to informing future treatment initiatives. This project was designed to be conducted within the clinical operations of 4 private addictions treatment centers. A structured interview was used to assess patients’ alcohol and other drug use and related variables (on treatment entry and at 1, 3, and 6 months following treatment discharge. The primary outcomes were percentage of days abstinent (PDA from alcohol and drugs, PDA from alcohol, and PDA from other drugs. Collateral reports during follow-up also were gathered. A total of 280 patients (56% men across the 4 programs participated. Percentage of days abstinent for each outcome increased significantly from baseline to the 1-month follow-up assessment, and this change was maintained at the 3- and 6-month follow-up assessments. Collateral reports mirrored the patient follow-up reports. Secondary outcomes of patient ratings of urges/cravings, depression, anxiety, and general life functioning all indicated significant improvement from baseline over the course of the follow-up. The results suggest the feasibility of conducting systematic outcome assessment in freestanding private addictions treatment environments.

Level of Alkenylbenzenes in Parsley and Dill Based Teas and Associated Risk Assessment Using the Margin of Exposure Approach.

Science.gov (United States)

Alajlouni, Abdalmajeed M; Al-Malahmeh, Amer J; Isnaeni, Farida Nur; Wesseling, Sebastiaan; Vervoort, Jacques; Rietjens, Ivonne M C M

2016-11-16

Risk assessment of parsley and dill based teas that contain alkenylbenzenes was performed. To this end the estimated daily intake (EDI) of alkenylbenzenes resulting from use of the teas was quantified. Since most teas appeared to contain more than one alkenylbenzene, a combined risk assessment was performed based on equal potency of all alkenylbenzenes or using a so-called toxic equivalency (TEQ) approach through defining toxic equivalency factors (TEFs) for the different alkenylbenzenes. The EDI values resulting from consuming one cup of tea a day were 0.2-10.1 μg/kg bw for the individual alkenylbenzenes, 0.6-13.1 μg/kg bw for the sum of the alkenylbenzenes, and 0.3-10.7 μg safrole equiv/kg bw for the sum of alkenylbenzenes when expressed in safrole equivalents. The margin of exposure (MOE) values obtained were generally <10000, indicating a concern if the teas would be consumed on a daily basis over longer periods of time.

Reliabilityy and operating margins of LWR fuels

International Nuclear Information System (INIS)

Strasser, A.A.; Lindquist, K.O.

1977-01-01

The margins to fuel thermal operating limits under normal and accident conditions are key to plant operating flexibility and impact on availability and capacity factor. Fuel performance problems that do not result in clad breach, can reduce these margins. However, most have or can be solved with design changes. Regulatory changes have been major factors in eroding these margins. Various methods for regaining the margins are discussed

Preoperative magnetic resonance imaging assessment of circumferential resection margin predicts disease-free survival and local recurrence: 5-year follow-up results of the MERCURY study.

Science.gov (United States)

Taylor, Fiona G M; Quirke, Philip; Heald, Richard J; Moran, Brendan J; Blomqvist, Lennart; Swift, Ian R; Sebag-Montefiore, David; Tekkis, Paris; Brown, Gina

2014-01-01

The prognostic relevance of preoperative high-resolution magnetic resonance imaging (MRI) assessment of circumferential resection margin (CRM) involvement is unknown. This follow-up study of 374 patients with rectal cancer reports the relationship between preoperative MRI assessment of CRM staging, American Joint Committee on Cancer (AJCC) TNM stage, and clinical variables with overall survival (OS), disease-free survival (DFS), and time to local recurrence (LR). Patients underwent protocol high-resolution pelvic MRI. Tumor distance to the mesorectal fascia of ≤ 1 mm was recorded as an MRI-involved CRM. A Cox proportional hazards model was used in multivariate analysis to determine the relationship of MRI assessment of CRM to survivorship after adjusting for preoperative covariates. Surviving patients were followed for a median of 62 months. The 5-year OS was 62.2% in patients with MRI-clear CRM compared with 42.2% in patients with MRI-involved CRM with a hazard ratio (HR) of 1.97 (95% CI, 1.27 to 3.04; P < .01). The 5-year DFS was 67.2% (95% CI, 61.4% to 73%) for MRI-clear CRM compared with 47.3% (95% CI, 33.7% to 60.9%) for MRI-involved CRM with an HR of 1.65 (95% CI, 1.01 to 2.69; P < .05). Local recurrence HR for MRI-involved CRM was 3.50 (95% CI, 1.53 to 8.00; P < .05). MRI-involved CRM was the only preoperative staging parameter that remained significant for OS, DFS, and LR on multivariate analysis. High-resolution MRI preoperative assessment of CRM status is superior to AJCC TNM-based criteria for assessing risk of LR, DFS, and OS. Furthermore, MRI CRM involvement is significantly associated with distant metastatic disease; therefore, colorectal cancer teams could intensify treatment and follow-up accordingly to improve survival outcomes.

Work, organisational practices, and margin of manoeuver during work reintegration.

Science.gov (United States)

O'Hagan, Fergal

2017-09-29

Many individuals of working age experience cardiovascular disease and are disabled from work as a result. The majority of research in cardiac work disability has focused on individual biological and psychological factors influencing work disability despite evidence of the importance of social context in work disability. In this article, the focus is on work and organisational features influencing the leeway (margin of manoeuvre) workers are afforded during work reintegration. A qualitative method was used. A large auto manufacturing plant was selected owing to work, organisational, and worker characteristics. Workplace context was assessed through site visits and meetings with stakeholders including occupational health, human resources and union personnel and a review of collective agreement provisions relating to seniority, benefits and accommodation. Worker experience was assessed using a series of in-depth interviews with workers (n = 12) returning to work at the plant following disabling cardiac illness. Data was analysed using qualitative content analysis. Workers demonstrated variable levels of adjustment to the workplace that could be related to production expectations and work design. Policies and practices around electronic rate monitoring, seniority and accommodation, and disability management practices affected the buffer available to workers to adjust to the workplace. Work qualities and organisational resources establish a margin of manoeuver for work reintegration efforts. Practitioners need to inform themselves of the constraints on work accommodation imposed by work organisation and collective agreements. Organisations and labour need to reconsider policies and practices that creates unequal accommodation conditions for disabled workers. Implications for rehabilitation Margin of manoeuvre offers a framework for evaluating and structuring work reintegration programmes. Assessing initial conditions for productivity expectations, context and ways

Impact of Margin Status on Local Recurrence After Mastectomy for Ductal Carcinoma In Situ

International Nuclear Information System (INIS)

Childs, Stephanie K.; Chen, Yu-Hui; Duggan, Margaret M.; Golshan, Mehra; Pochebit, Stephen; Punglia, Rinaa S.; Wong, Julia S.; Bellon, Jennifer R.

2013-01-01

Purpose: To examine the rate of local recurrence according to the margin status for patients with pure ductal carcinoma in situ (DCIS) treated by mastectomy. Methods and Materials: One hundred forty-five consecutive women who underwent mastectomy with or without radiation therapy for DCIS from 1998 to 2005 were included in this retrospective analysis. Only patients with pure DCIS were eligible; patients with microinvasion were excluded. The primary endpoint was local recurrence, defined as recurrence on the chest wall; regional and distant recurrences were secondary endpoints. Outcomes were analyzed according to margin status (positive, close (≤2 mm), or negative), location of the closest margin (superficial, deep, or both), nuclear grade, necrosis, receptor status, type of mastectomy, and receipt of hormonal therapy. Results: The primary cohort consisted of 142 patients who did not receive postmastectomy radiation therapy (PMRT). For those patients, the median follow-up time was 7.6 years (range, 0.6-13.0 years). Twenty-one patients (15%) had a positive margin, and 23 patients (16%) had a close (≤2 mm) margin. The deep margin was close in 14 patients and positive in 6 patients. The superficial margin was close in 13 patients and positive in 19 patients. One patient experienced an isolated invasive chest wall recurrence, and 1 patient had simultaneous chest wall, regional nodal, and distant metastases. The crude rates of chest wall recurrence were 2/142 (1.4%) for all patients, 1/21 (4.8%) for those with positive margins, 1/23 (4.3%) for those with close margins, and 0/98 for patients with negative margins. PMRT was given as part of the initial treatment to 3 patients, 1 of whom had an isolated chest wall recurrence. Conclusions: Mastectomy for pure DCIS resulted in a low rate of local or distant recurrences. Even with positive or close mastectomy margins, the rates of chest wall recurrences were so low that PMRT is likely not warranted

[Spanish validation of the MacArthur Competence Assessment Tool for Treatment interview to assess patients competence to consent treatment].

Science.gov (United States)

Alvarez Marrodán, Ignacio; Baón Pérez, Beatriz; Navío Acosta, Mercedes; López-Antón, Raul; Lobo Escolar, Elena; Ventura Faci, Tirso

2014-09-09

To validate the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) Spanish version, which assesses the mental capacity of patients to consent treatment, by examining 4 areas (Understanding, Appreciation, Reasoning and Expressing a choice). 160 subjects (80 Internal Medicine inpatients, 40 Psychiatric inpatients and 40 healthy controls). MacCAT-T, Mini-Mental Status Examination (MMSE). Feasibility study, reliability and validity calculations (against to gold standard of clinical expert). Mean duration of the MacCAT-T interview was 18min. Inter-rater reliability: Intraclass correlation coefficient for Understanding=0.98, Appreciation=0.97, Reasoning=0.98, Expressing a choice=0.91. Internal consistency (Cronbach's alpha): Understanding=0.87, for Appreciation=0.76, for Reasoning=0.86. Patients considered to be incapable (gold standard) scored lower in all the MacCAT-T areas. Poor performance on the MacCAT-T was related to cognitive impairment assessed by MMSE. Spanish version of the MacCAT-T is feasible, reliable, and valid for assessing the capacity of patients to consent treatment. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Difference in the Set-up Margin between 2D Conventional and 3D CT Based Planning in Patients with Early Breast Cancer

International Nuclear Information System (INIS)

Jo, Sun Mi; Chun, Mi Sun; Kim, Mi Hwa; Oh, Young Taek; Noh, O Kyu; Kang, Seung Hee

2010-01-01

Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inflamammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. The use of 3D CT based planning reduced the

Difference in the Set-up Margin between 2D Conventional and 3D CT Based Planning in Patients with Early Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

Jo, Sun Mi; Chun, Mi Sun; Kim, Mi Hwa; Oh, Young Taek; Noh, O Kyu [Ajou University School of Medicine, Seoul (Korea, Republic of); Kang, Seung Hee [Inje University, Ilsan Paik Hospital, Ilsan (Korea, Republic of)

2010-11-15

Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inflamammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. The use of 3D CT based planning reduced the

A quantitative evaluation of seismic margin of typical sodium piping

International Nuclear Information System (INIS)

Morishita, Masaki

1999-05-01

It is widely recognized that the current seismic design methods for piping involve a large amount of safety margin. From this viewpoint, a series of seismic analyses and evaluations with various design codes were made on typical LMFBR main sodium piping systems. Actual capability against seismic loads were also estimated on the piping systems. Margins contained in the current codes were quantified based on these results, and potential benefits and impacts to the piping seismic design were assessed on possible mitigation of the current code allowables. From the study, the following points were clarified; 1) A combination of inelastic time history analysis and true (without margin)strength capability allows several to twenty times as large seismic load compared with the allowable load with the current methods. 2) The new rule of the ASME is relatively compatible with the results of inelastic analysis evaluation. Hence, this new rule might be a goal for the mitigation of seismic design rule. 3) With this mitigation, seismic design accommodation such as equipping with a large number of seismic supports may become unnecessary. (author)

Marginal leakage of two newer glass-ionomer-based sealant materials assessed using micro-CT.

NARCIS (Netherlands)

Chen, X.; Cuijpers, V.M.J.I.; Fan, M.; Frencken, J.E.F.M.

2010-01-01

OBJECTIVES: To test newer glass-ionomer-based materials as sealant materials. One glass-ionomer sealant was light-cured to obtain an early setting reaction. The null-hypothesis tested was: there is no difference in marginal leakage of sealants produced with high-viscosity glass-ionomer, with and

Marginal zone in femoral head avascular necrosis: scintigraphic characteristics and clinical prognostic value

International Nuclear Information System (INIS)

Milcinski, M.; Sedonja, I.; Dolinar, D.; Jevtic, V.

2002-01-01

Aim: Marginal zone, seen on magnetic resonance imaging (MRI) in femoral head avascular necrosis, consists of granulation tissue and sclerosis at the junction of necrotic and normal bone. Prognostic value of this finding is not clear. Aim of our study was to evaluate osteoblastic activity of marginal zone with bone scintigraphy and to assess prognostic importance of marginal zone for further evolution of femoral head necrosis. Material and methods: MRI was performed in 37 hips in 26 patients (17 m, 9 f, 20-64 y, mean 42,9 y) with Ficat 0-II avascular necrosis (SE T1W, STIR and SE T1W FAT.SAT after Gd DTPA in the coronal plane and GE FLASH in the sagittal plane). In 26 hips of 17 patients planar and pinhole scintigraphy with 99mTc-DPD was performed. Results: On MRI, marginal zone divided necrotic and normal bone in 26/37 (70,3%) hips, in 14/26 it was thin (2% of femoral head diameter or less), but in 12/26 it was wide (more than 2% of femoral head diameter). In 11/37 (29,7%) hips marginal zone was not seen. Pinhole scintigraphy was performed in 26 hips; in all 10/10 (100%) hips with wide marginal zone, seen on MRI, increased osteoblastic activity was detected, while only in 1/9 (11,1%) hips with thin marginal zone on MRI osteoblastic activity was increased. Patients were followed 1 to 5 years (mean 2,2 y). In hips without marginal zone no collapse of femoral head was seen until now, in 2/11 (18,2%) femoral heads MRI and clinical regression was observed. Ten of 12 lesions with wide marginal zone (83,3 %) collapsed 0,25 to 2,5 (mean 1) years after onset of pain. Two of 12 lesions with wide marginal zone (16,7%) have not collapsed until now. From lesions with thin marginal zone, 4/14 (28,6 %) collapsed 0,7 to 3 (mean 1,9) years after onset of pain, 10/14 (71,4%) did not collapse until now. Conclusion: Increased osteoblastic activity in wide marginal zone between necrotic and vital bone in hip avascular necrosis is bad prognostic factor for femoral head collapse

SU-E-J-88: Margin Reduction of Level II/III Planning Target Volume for Image-Guided Simultaneous Integrated Boost Head-And-Neck Treatment

International Nuclear Information System (INIS)

Can, S; Neylon, J; Qi, S; Santhanam, A; Low, D

2014-01-01

Purpose: To investigate the feasibility of improved normal tissue sparing for head-and-neck (H'N) image-guided radiotherapy (IGRT) by employing tighter CTV-to-PTV margins for target level II/III though a GPU-based deformable image registration and dose accumulation framework. Methods: Ten H'N simultaneous integrated boost cases treated on TomoTherapy were retrospectively analyzed. Weekly kVCT scans in addition to daily MVCT scans were acquired for each patient. Reduced margin plans were generated with 0- mm margin for level II and III PTV (while 3-5 mm margin for PTV1) and compared with the standard margin plan using 3-5mm margin to all CTV1-3 (reference plan). An in-house developed GPU-based 3D image deformation tool was used to register and deform the weekly KVCTs with the planning CT and determine the delivered mean/minimum/maximum dose, dose volume histograms (DVHs), etc. Results: Compared with the reference plans, the averaged cord maximum, the right and left parotid doses reduced by 22.7 %, 16.5 %, and 9 % respectively in the reduced margin plans. The V95 for PTV2 and PTV3 were found within 2 and 5% between the reference and tighter margin plans. For the reduced margin plans, the averaged cumulative mean doses were consistent with the planned dose for PTV1, PTV2 and PTV3 within 1.5%, 1.7% and 1.4%. Similar dose variations of the delivered dose were seen for the reference and tighter margin plans. The delivered maximum and mean doses for the cord were 3.55 % and 2.37% higher than the planned doses; a 5 % higher cumulative mean dose for the parotids was also observed for the delivered dose than the planned doses in both plans. Conclusion: By imposing tighter CTV-to-PTV margins for level II and III targets for H'N irradiation, acceptable cumulative doses were achievable when coupled with weekly kVCT guidance while improving normal structure sparing

Marginal cost application in the power industry

International Nuclear Information System (INIS)

Twardy, L.; Rusak, H.

1994-01-01

Two kind of marginal costs, the short-run and the long-run, are defined. The former are applied in conditions when the load increase is not accompanied neither by the increase of the transmission capacity not the installed capacity while the latter assume new investments to expand the power system. The long-run marginal costs be used to forecast optimized development of the system. They contain two main components: the marginal costs of capacity and the marginal costs of energy. When the long-run marginal costs are calculated, each component is considered for particular voltage levels, seasons of the year, hours of the day - selected depending on the system reliability factor as well as on its load level. In the market economy countries the long-run marginal costs can be used for setting up the electric energy tariffs. (author). 7 refs, 11 figs

What is the significance of a microscopically positive resection margin in the curative-intent treatment of rectal adenocarcinoma? A retrospective study.

Science.gov (United States)

Fekete, Z; Muntean, A; Irimie, A; Hica, S; Resiga, L; Todor, N; Nagy, V

2013-01-01

The aim of this study was to analyze the characteristics of patients with rectal cancer operated with a microscopic positive margin (R1) and thus avoid these situations or adapt treatment in these particular cases. We reviewed all the pathology data of resected specimens from patients with rectal or recto-sigmoid cancer operated with curative intent at the Institute of Oncology "Prof. Dr. Ion Chiricuta" between 2000-2011 (763 patients in 12 years) and the pathology files of patients from other institutions referred for adjuvant treatment to our hospital (318 patients). We included patients with anterior resection, Hartmann's procedure and abdomino-perineal resection, but we excluded patients with local excision and patients with R2/R1 at first, but R0 after re-resection (56 patients). We have identified 31 patients with R1, but had to exclude one case from analysis because this patient was lost to follow-up. With surgery alone the local relapse (LR) was unavoidable. In the neoadjuvant chemoradiation (CRT) group 85.7% of the patients did not develop LR despite of R1. In the adjuvant CRT cohort 50% of the patients were LR-free at 2 years after conventional radiotherapy (p<0.01). Based on these results it is concluded that a clear resection margin is extremely important for the local control of rectal cancer, because it cannot be always compensated by adjuvant CRT. In R1 cases neoadjuvant CRT seems to offer better prognosis than adjuvant CRT. To avoid R1 and its consequences a good quality control of total mesorectal excision (TME) is needed and CRT should be done before and not after surgery. R1 after primary surgery needs to be compensated by re-resection if possible, otherwise probably high dose radiotherapy with chemotherapy is needed.

Impact of Close and Positive Margins in Transoral Laser Microsurgery for Tis–T2 Glottic Cancer

Directory of Open Access Journals (Sweden)

Ivana Fiz

2017-10-01

Full Text Available IntroductionTransoral laser microsurgery (TLM represents one of the most effective treatment strategies for Tis–T2 glottic squamous cell carcinomas (SCC. The prognostic influence of close/positive margins is still debated, and the role of narrow band imaging (NBI in their intraoperative definition is still to be validated on large cohort of patients. This study analyzed the influence of margin status on recurrence-free survival (RFS and disease-specific survival (DSS.MethodsWe retrospectively studied 507 cases of pTis–T1b (Group A and 127 cases of pT2 (Group B glottic SCC. We identified the following margin status: negative (n = 232, close superficial (n = 79, close deep (CD (n = 35, positive single superficial (n = 146, positive multiple superficial (n = 94, and positive deep (n = 48 and analyzed their impact on RFS and DSS. Close margins were defined by tumor-margin distance <1 mm. Pre-TLM margins were defined by white light in 323 patients, whereas NBI was employed in 311 patients.ResultsIn Group A, DSS and RFS were reduced in positive multiple superficial and positive deep margins (DSS = 96.1 and 97%, both p < 0.05; RFS = 72%, p < 0.001 and 75.8%, p < 0.01. In Group B, DSS was reduced in positive multiple superficial margins (82.4%, p < 0.05. RFS was reduced in positive single superficial, positive multiple superficial, and positive deep margins (62.5, 41.2, and 53.3%, p < 0.01. In the entire population, RFS was reduced in CD margins (77.1%, p < 0.05. Use of NBI led to improvement in RFS and DSS.ConclusionThe study indicates that close and positive single superficial margins do not affect DSS. By contrast, all types of margin positivity predict the occurrence of relapses, albeit with different likelihood, depending on stage/margin type. CD margins should be considered as a single risk factor. Use of NBI granted better intraoperative margins definition.

Safety margin in irradiation of colorectal liver metastases: assessment of the control dose of micrometastases

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Seidensticker Max

2010-03-01

Full Text Available Abstract Backround Micrometastases of colorectal liver metastases are present in up to 50% of lesions. In this study we sought to determine the threshold dose for local control of occult micrometastases in patients undergoing CT (computed tomography-guided brachytherapy of colorectal liver metastases. Materials and methods Nineteen patients demonstrated 34 local tumor recurrences originating from micrometastases after CT-guided brachytherapy of 27 colorectal liver metastases. We considered a local tumor recurrence as originating from a micrometastasis if tumor regrowth occurred adjacent to a formerly irradiated lesion and the distance of the 3D isocenter of the new lesion was ≤ 23.5 mm from the previous tumor margin. Follow-up MRI was fused with the planning-CT and dosimetry data. Two reviewers independently indicated the dose exposure at the isocenter of the micrometastases. Statistical analysis included an analysis of variance (ANOVA using backward selection. 95% tolerance intervals with coverage of 87.5 and 75% of the data of the normal distribution were calculated. Results The median distance of the micrometastases to the margin of the originating colorectal metastases was 8.75 mm (1-21 mm. Dose exposure at the isocenter was 12.25 Gy (7-19.8 in median. We stratified according to the distance from the isocenter to the initial tumor margin: ≤ 9 mm, > 9-15 mm and > 15 mm. The median dose in the according isocenters was 13.18, 11.6 and 11.85 Gy. The threshold dose failing to prevent micrometastasis growth was sigificantly higher in a subgroup of lesions with ≤ 9 mm distance as compared to > 15 mm (13.18 vs 11.85 Gy. Adjuvant chemotherapy correlated with greater distance of micrometastasis growth to the tumor but not with the threshold dose. Conclusion To prevent loss of local tumor control by continuous growth of micrometastases a threshold dose of 15,4 Gy (single fraction should be delivered at a distance of 21 mm to the gross tumor

Workers' marginal costs of commuting

DEFF Research Database (Denmark)

van Ommeren, Jos; Fosgerau, Mogens

2009-01-01

This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour...

Assessment and Treatment of Pain during Treatment of Buruli Ulcer.

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Janine de Zeeuw

Full Text Available Buruli ulcer (BU is described as a relatively painless condition; however clinical observations reveal that patients do experience pain during their treatment. Knowledge on current pain assessment and treatment in BU is necessary to develop and implement a future guideline on pain management in BU.A mixed methods approach was used, consisting of information retrieved from medical records on prescribed pain medication from Ghana and Benin, and semi-structured interviews with health care personnel (HCP from Ghana on pain perceptions, assessment and treatment. Medical records (n = 149 of patients treated between 2008 and 2012 were collected between November 2012 and August 2013. Interviews (n = 11 were audio-taped, transcribed verbatim and qualitatively analyzed.In 113 (84% of the 135 included records, pain medication, mostly simple analgesics, was prescribed. In 48% of the prescriptions, an indication was not documented. HCP reported that advanced BU could be painful, especially after wound care and after a skin graft. They reported not be trained in the assessment of mild pain. Pain recognition was perceived as difficult, as patients were said to suppress or to exaggerate pain, and to have different expectations regarding acceptable pain levels. HCP reported a fear of side effects of pain medication, shortage and irregularities in the supply of pain medication, and time constraints among medical doctors for pain management.Professionals perceived BU disease as potentially painful, and predominantly focused on severe pain. Our study suggests that pain in BU deserves attention and should be integrated in current treatment.

Meta-Analysis of Correlations Between Marginal Bone Resorption and High Insertion Torque of Dental Implants.

Science.gov (United States)

Li, Haoyan; Liang, Yongqiang; Zheng, Qiang

2015-01-01

To evaluate correlations between marginal bone resorption and high insertion torque value (> 50 Ncm) of dental implants and to assess the significance of immediate and early/conventional loading of implants under a certain range torque value. Specific inclusion and exclusion criteria were used to retrieve eligible articles from Ovid, PubMed, and EBSCO up to December 2013. Screening of eligible studies, quality assessment, and data extraction were conducted in duplicate. The results were expressed as random/fixed-effects models using weighted mean differences for continuous outcomes with 95% confidence intervals. Initially, 154 articles were selected (11 from Ovid, 112 from PubMed, and 31 from EBSCO). After exclusion of duplicate articles and articles that did not meet the inclusion criteria, six clinical studies were selected. Assessment of P values revealed that correlations between marginal bone resorption and high insertion torque were not statistically significant and that there was no difference between immediately versus early/conventionally loaded implants under a certain range of torque. None of the meta-analyses revealed any statistically significant differences between high insertion torque and conventional insertion torque in terms of effects on marginal bone resorption.

Pathology of nodal marginal zone lymphomas.

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Pileri, Stefano; Ponzoni, Maurilio

Nodal marginal zone B cell lymphomas (NMZLs) are a rare group of lymphoid disorders part of the spectrum of marginal zone B-cell lymphomas, which encompass splenic marginal one B-cell lymphoma (SMZL) and extra nodal marginal zone of B-cell lymphoma (EMZL), often of MALT-type. Two clinicopathological forms of NMZL are recognized: adult-type and pediatric-type, respectively. NMZLs show overlapping features with other types of MZ, but distinctive features as well. In this review, we will focus on the salient distinguishing features of NMZL mostly under morphological/immunophenotypical/molecular perspectives in views of the recent acquisitions and forthcoming updated 2016 WHO classification of lymphoid malignancies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment and Treatment of Co-occurring Eating Disorders in Privately Funded Addiction Treatment Programs

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Killeen, Therese K.; Greenfield, Shelly F.; Bride, Brian E.; Cohen, Lisa; Gordon, Susan Merle; Roman, Paul M.

2011-01-01

Privately-funded addiction treatment programs were surveyed to increase understanding of assessment and current treatment options for patients with co-occurring substance use and eating disorders. Data were collected from face-to-face interviews with program administrators of a nationally representative sample of 345 private addiction treatment programs. Although the majority of programs reported screening for eating disorders, programs varied in screening instruments used. Sixty-seven percent reported admitting cases of low severity. Twenty-one percent of programs attempt to treat eating disorders. These results highlight the need for education of addiction treatment professionals in assessment, referral and treatment of eating disorders. PMID:21477048

Dosimetric properties of a novel brachytherapy balloon applicator for the treatment of malignant brain-tumor resection-cavity margins

International Nuclear Information System (INIS)

Dempsey, James F.; Williams, Jeffery A.; Stubbs, James B.; Patrick, Timothy J.; Williamson, Jeffrey F.

1998-01-01

-seed implants in several respects. Manipulation of the dosimetric properties of the device can improve its characteristics for brain tumor treatment and may make it suitable for boosting the lumpectomy margins in conservative breast cancer treatment

Therapy of radiation injuries of the rat marginal periodontium

International Nuclear Information System (INIS)

Lieske, W.; Stahlberg, N.

1987-01-01

The influence of different consistencies of food and of ionizing radiations on the marginal periodontium of female Wistar rats was studied. Microorganisms play an important part in the development of inflammatory histological reactions. Chlorhexidine and metronidazole treatment, resp., revealed a favourable effect on the inflammatory alterations of the periodontium. The evaluation was based on semiquantitative identification of plaques as well as on histological investigations of the interdental col and of the subepithelial connective tissue

Assessment of the proposed decontamination and waste treatment facility at LLNL

International Nuclear Information System (INIS)

Cohen, J.J.

1987-01-01

To provide a centralized decontamination and waste treatment facility (DWTF) at LLNL, the construction of a new installation has been planned. Objectives for this new facility were to replace obsolete, structurally and environmentally sub-marginal liquid and solid waste process facilities and decontamination facility and to bring these facilities into compliance with existing federal, state and local regulations as well as DOE orders. In a previous study, SAIC conducted a preliminary review and evaluation of existing facilities at LLNL and cost effectiveness of the proposed DWTF. This document reports on a detailed review of specific aspects of the proposed DWTF

Biodiversity and agro-ecology in field margins.

Science.gov (United States)

De Cauwer, B; Reheul, D; Nijs, I; Milbau, A

2005-01-01

This multidisciplinary study investigates agro-ecological functions (nature conservation, agriculture, environment) and implications of newly created, mown sown and unsown field margin strips installed on ex-arable land to increase biodiversity. From conservational concern, the development of species rich field margin strips was not strongly affected by the installed type of margin strip since species diversity converged over time, whether strips were sown or not. Convergence between unsown and sown margin strips occurred also in terms of species composition: unsown and sown strips became similar over time. Mowing without removal of cuttings significantly reduced species richness, yielded more grassy margin strips and delayed similarity in species composition between sown and unsown margin strips. Species richness on the longer term was not significantly affected by light regime nor by disturbance despite significant temporary effects shortly after the disturbance event. On the contrary vegetation composition in terms of importance of functional groups changed after disturbance: the share of spontaneous species within functional groups increased resulting in higher similarity between the sown and unsown vegetation. Furthermore risk of invasion was highest in the disturbed unsown community on the unshaded side of a tree lane. A positive effect of botanical diversity on insect number and diversity was found. However the effects of botanical diversity on insect number was mediated by light regime. At high light availability differences between plant communities were more pronounced compared to low light availablilty. The abundance of some insect families was dependent on the vegetation composition. Furthermore light availability significantly influenced insect diversity as well as the spatial distribution of families. From agricultural concern, installing margin strips by sowing a species mixture and a mowing regime with removal of cuttings are good practices to

Advancing Understanding of Earthquakes by Drilling an Eroding Convergent Margin

Science.gov (United States)

von Huene, R.; Vannucchi, P.; Ranero, C. R.

2010-12-01

perhaps geologically than the Nankai margin. The developing Central American countries do not have the resources to contribute to IODP but this should not deter acquiring the scientific insights proposed in CRISP considering the broader scientific benefits. Such benefits include the first sampling and instrumentation of an actively eroding plate interface and drilling near or into an earthquake asperity. Drilling an eroding margin should significantly advance understanding of subduction zone fault mechanisms and help improve assessment of future hazardous earthquakes and tsunamis.

Biomechanical Effect of Margin Convergence Techniques: Quantitative Assessment of Supraspinatus Muscle Stiffness.

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Taku Hatta

Full Text Available Although the margin convergence (MC technique has been recognized as an option for rotator cuff repair, little is known about the biomechanical effect on repaired rotator cuff muscle, especially after supplemented footprint repair. The purpose of this study was to assess the passive stiffness changes of the supraspinatus (SSP muscle after MC techniques using shear wave elastography (SWE. A 30 × 40-mm U-shaped rotator cuff tear was created in 8 cadaveric shoulders. Each specimen was repaired with 6 types of MC technique (1-, 2-, 3-suture MC with/without footprint repair, in a random order at 30° glenohumeral abduction. Passive stiffness of four anatomical regions in the SSP muscle was measured based on an established SWE method. Data were obtained from the SSP muscle at 0° abduction under 8 different conditions: intact (before making a tear, torn, and postoperative conditions with 6 techniques. MC techniques using 1-, or 2-suture combined with footprint repair showed significantly higher stiffness values than the intact condition. Passive stiffness of the SSP muscle was highest after a 1-suture MC with footprint repair for all regions when compared among all repair procedures. There was no significant difference between the intact condition and a 3-suture MC with footprint repair. MC techniques with single stitch and subsequent footprint repair may have adverse effects on muscle properties and tensile loading on repair, increasing the risk of retear of repairs. Adding more MC stitches could reverse these adverse effects.

Account for uncertainties of control measurements in the assessment of design margin factors

International Nuclear Information System (INIS)

Dementiev, V. G.; Sidorenko, V. D.; Shishkov, L. K.

2011-01-01

The paper discusses the feasibility of accounting for uncertainties of control measurements in estimation of design margin factors. The feasibility is also taken into consideration proceeding from the fact how much the processed measured data were corrected by a priori calculated data of measurable parameters. The possibility and feasibility of such data correction is demonstrated by the authors with the help of Bayes theorem famous in mathematical statistics. (Authors)

[Planning of esthetic oral rehabilitation according to correlative analysis of clinical and morphological features of the marginal gingiva].

Science.gov (United States)

Stafeev, A A; Zinov'ev, G I; Drozdov, D D

2015-01-01

The orthopedic restoration and related to its clinical stages (preparation, gingival retraction, impression) is often associated with complications which arise from the marginal gingiva. The technology of indirect ceramic restoration requires an assessment of the clinical and morphological parameters of periodontal tissues. The study outlines correlation between the type of periodontal histhology and inflammatory and degenerative complications that has been established after the analysis of morphofunctional state of periodontal tissue. Results of clinical studies and correlation analysis of clinical and morphological parameters of marginal gingiva has shown that important parameter influencing the choice of manufacturing technology are the position of restoration margin relatively to marginal gingiva and periodontal morphotype.

Erosion and marginalization in Pahuatlán municipality, Puebla: A binomial of causality?

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Rosalía Castelán Vega

2012-02-01

Full Text Available An understanding of the interaction between deterioration of the environment and marginalization of communities is essential in order to formulate public policies that will combine social and environmental objectives. The aim of the present study was to explore the relationship between erosion and marginalization in the municipality of Pahuatlán, Puebla, Mexico. The erosion was assessed by the methods developed by FAO and Ruiz et al. Marginalization was determined by the Consejo Nacional de Población (CONAPO method using Instituto Nacional de Estadística, Geografía e Informática (INEGI indicators. The relationship was established by a simple correspondence analysis and was confirmed by Pearson´s Chi-square test. Erosion could be assigned to one of three grades: moderate, severe and very severe. In the 32 towns that constitute the municipality, marginalization was moderate in 5, severe in 14 and very severe in 13. The correspondence analysis and the Chi-square test showed a causal relationship between erosion and marginalization, although it was not possible to detect with certainty which is the cause and which the effect. However, the results can contribute to the design of sustainable strategies for the municipality.

Implications of power uprates on safety margins of nuclear power plants. Report of a technical meeting

International Nuclear Information System (INIS)

2004-09-01

The safety of nuclear power plants (NPPs) is based on the defence in depth concept, which relies on successive physical barriers (fuel matrix, cladding, primary system pressure boundary and containment) and other provisions to control radioactive materials and on multiple levels of protection against damage to these barriers. Deterministic safety analysis is an important tool for conforming the adequacy and efficiency of provisions within the defence in depth concept and is used to predict the response of an NPP in predetermined operational states. This type of safety analysis applies a specific set of rules and specific acceptance criteria. Deterministic analysis is typically focused on neutronic, thermohydraulic, radiological and structural aspects, which are often analysed with different computational tools. The advanced computational tools developed for deterministic safety analysis are used for better establishment and utilization of licensing margins or safety margins in consideration of analysis results. At the same time, the existence of such margins ensures that NPPs operate safely in all modes of operation and at all times. To properly assess and address the existing margins and to be able to take advantage of unnecessary conservatisms, state of the art analytical tools intended for safety assessment have been developed. Progress made in the development and application of modern codes for safety analysis and better understanding of phenomena involved in plant design and operation enable the analysts to determine safety margins in consideration of analysis results (licensing margins) with higher precision. There is a general tendency for utilities to take advantage of unnecessarily large conservatisms in safety analyses and to utilize them for reactor power uprates, better utilization of nuclear fuel, higher operational flexibility and for justification of lifetime extension. The present publication sets forth the results of a Technical Meeting on the

Risk insights from seismic margin reviews

International Nuclear Information System (INIS)

Budnitz, R.J.

1990-01-01

This paper discusses the information that has been derived from the three seismic-margin reviews conducted so far, and the information that is potentially available from using the seismic-margin method more generally. There are two different methodologies for conducting seismic margin reviews of nuclear power plants, one developed under NRC sponsorship and one developed under sponsorship of the Electric Power Research Institute. Both methodologies will be covered in this paper. The paper begins with a summary of the steps necessary to complete a margin review, and will then outline the key technical difficulties that need to be addressed. After this introduction, the paper covers the safety and operational insights derived from the three seismic-margin reviews already completed: the NRC-sponsored review at Maine Yankee; the EPRI-sponsored review at Catawba; and the joint EPRI/NRC/utility effort at Hatch. The emphasis is on engineering insights, with attention to the aspects of the reviews that are easiest to perform and that provide the most readily available insights

Exactly marginal deformations from exceptional generalised geometry

Energy Technology Data Exchange (ETDEWEB)

Ashmore, Anthony [Merton College, University of Oxford,Merton Street, Oxford, OX1 4JD (United Kingdom); Mathematical Institute, University of Oxford,Andrew Wiles Building, Woodstock Road, Oxford, OX2 6GG (United Kingdom); Gabella, Maxime [Institute for Advanced Study,Einstein Drive, Princeton, NJ 08540 (United States); Graña, Mariana [Institut de Physique Théorique, CEA/Saclay,91191 Gif-sur-Yvette (France); Petrini, Michela [Sorbonne Université, UPMC Paris 05, UMR 7589, LPTHE,75005 Paris (France); Waldram, Daniel [Department of Physics, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom)

2017-01-27

We apply exceptional generalised geometry to the study of exactly marginal deformations of N=1 SCFTs that are dual to generic AdS{sub 5} flux backgrounds in type IIB or eleven-dimensional supergravity. In the gauge theory, marginal deformations are parametrised by the space of chiral primary operators of conformal dimension three, while exactly marginal deformations correspond to quotienting this space by the complexified global symmetry group. We show how the supergravity analysis gives a geometric interpretation of the gauge theory results. The marginal deformations arise from deformations of generalised structures that solve moment maps for the generalised diffeomorphism group and have the correct charge under the generalised Reeb vector, generating the R-symmetry. If this is the only symmetry of the background, all marginal deformations are exactly marginal. If the background possesses extra isometries, there are obstructions that come from fixed points of the moment maps. The exactly marginal deformations are then given by a further quotient by these extra isometries. Our analysis holds for any N=2 AdS{sub 5} flux background. Focussing on the particular case of type IIB Sasaki-Einstein backgrounds we recover the result that marginal deformations correspond to perturbing the solution by three-form flux at first order. In various explicit examples, we show that our expression for the three-form flux matches those in the literature and the obstruction conditions match the one-loop beta functions of the dual SCFT.

Clearing margin system in the futures markets—Applying the value-at-risk model to Taiwanese data

Science.gov (United States)

Chiu, Chien-Liang; Chiang, Shu-Mei; Hung, Jui-Cheng; Chen, Yu-Lung

2006-07-01

This article sets out to investigate if the TAIFEX has adequate clearing margin adjustment system via unconditional coverage, conditional coverage test and mean relative scaled bias to assess the performance of three value-at-risk (VaR) models (i.e., the TAIFEX, RiskMetrics and GARCH-t). For the same model, original and absolute returns are compared to explore which can accurately capture the true risk. For the same return, daily and tiered adjustment methods are examined to evaluate which corresponds to risk best. The results indicate that the clearing margin adjustment of the TAIFEX cannot reflect true risks. The adjustment rules, including the use of absolute return and tiered adjustment of the clearing margin, have distorted VaR-based margin requirements. Besides, the results suggest that the TAIFEX should use original return to compute VaR and daily adjustment system to set clearing margin. This approach would improve the funds operation efficiency and the liquidity of the futures markets.

Observations at convergent margins concerning sediment subduction, subduction erosion, and the growth of continental crust

Science.gov (United States)

von Huene, Roland E.; Scholl, D. W.

1991-01-01

subducted beneath the frontal accretionary body and its active buttress. In rounded figures the contemporary rate of solid-volume sediment subduction at convergent ocean margins (???43,500 km) is calculated to be 1.5 km3/yr. Correcting type 1 margins for high rates of terrigenous seafloor sedimentation during the past 30 m.y. or so sets the long-term rate of sediment subduction at 1.0 km3/yr. The bulk of the subducted material is derived directly or indirectly from continental denudation. Interstitial water currently expulsed from accreted and deeply subducted sediment and recycled to the ocean basins is estimated at 0.9 km3/yr. The thinning and truncation caused by subduction erosion of the margin's framework rock and overlying sedimentary deposits have been demonstrated at many convergent margins but only off northern Japan, central Peru, and northern Chile has sufficient information been collected to determine average or long-term rates, which range from 25 to 50 km3/m.y. per kilometer of margin. A conservative long-term rate applicable to many sectors of convergent margins is 30 km3/km/m.y. If applied to the length of type 2 margins, subduction erosion removes and transports approximately 0.6 km3/yr of upper plate material to greater depths. At various places, subduction erosion also affects sectors of type 1 margins bordered by small- to medium-sized accretionary prisms (for example, Japan and Peru), thus increasing the global rate by possibly 0.5 km3/yr to a total of 1.1 km3/yr. Little information is available to assess subduction erosion at margins bordered by large accretionary prisms. Mass balance calculations allow assessments to be made of the amount of subducted sediment that bypasses the prism and underthrusts the margin's rock framework. This subcrustally subducted sediment is estimated at 0.7 km3/yr. Combined with the range of terrestrial matter removed from the margin's rock framework by subduction erosion, the global volume of subcrustally subducted materia

RISK-INFORMED SAFETY MARGIN CHARACTERIZATION

International Nuclear Information System (INIS)

Dinh, Nam; Szilard, Ronaldo

2009-01-01

The concept of safety margins has served as a fundamental principle in the design and operation of commercial nuclear power plants (NPPs). Defined as the minimum distance between a system's 'loading' and its 'capacity', plant design and operation is predicated on ensuring an adequate safety margin for safety-significant parameters (e.g., fuel cladding temperature, containment pressure, etc.) is provided over the spectrum of anticipated plant operating, transient and accident conditions. To meet the anticipated challenges associated with extending the operational lifetimes of the current fleet of operating NPPs, the United States Department of Energy (USDOE), the Idaho National Laboratory (INL) and the Electric Power Research Institute (EPRI) have developed a collaboration to conduct coordinated research to identify and address the technological challenges and opportunities that likely would affect the safe and economic operation of the existing NPP fleet over the postulated long-term time horizons. In this paper we describe a framework for developing and implementing a Risk-Informed Safety Margin Characterization (RISMC) approach to evaluate and manage changes in plant safety margins over long time horizons

Assessing self-determined motivation for addiction treatment: validity of the Treatment Entry Questionnaire.

Science.gov (United States)

Urbanoski, Karen A; Wild, T Cameron

2012-07-01

Although legal, formal, and informal social controls are frequently used to pressure individuals to enter treatment, motivational consequences of using these tactics have been neglected. Self-determination theory (SDT) provides a useful perspective for understanding client experiences of social controls and highlights the importance of self-determined motivation for long-term behavior change. This study assessed the construct validity of the Treatment Entry Questionnaire (TEQ), a brief scale derived from SDT to measure identified, introjected, and external treatment motivation. Two independent samples of clients entering Canadian residential and outpatient treatment completed TEQ items (ns = 529 and 623). Exploratory and confirmatory factor analyses supported a 9-item version of the scale, with 3 factors aligning with SDT motivational subtypes. Subscales showed high internal consistency and correlated as expected with social controls and perceived coercion at treatment entry. The TEQ-9 is a valid option for assessing self-determined motivation in clinical practice and evaluating coerced addiction treatment. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of Blood Contamination on Marginal Adaptation and Surface Microstructure of Mineral Trioxide Aggregate: A SEM Study.

Science.gov (United States)

Salem Milani, Amin; Rahimi, Saeed; Froughreyhani, Mohammad; Vahid Pakdel, Mahdi

2013-01-01

In various clinical situations, mineral trioxide aggregate (MTA) may come into direct contact or even be mixed with blood. The aim of the present study was to evaluate the effect of exposure to blood on marginal adaptation and surface microstructure of MTA. Thirty extracted human single-rooted teeth were used. Standard root canal treatment was carried out. Root-ends were resected, and retrocavities were prepared. The teeth were randomly divided into two groups (n = 15): in group 1, the internal surface of the cavities was coated with fresh blood. Then, the cavities were filled with MTA. The roots were immersed in molds containing fresh blood. In group 2, the aforementioned procedures were performed except that synthetic tissue fluid (STF) was used instead of blood. To assess the marginal adaptation, "gap perimeter" and "maximum gap width" were measured under scanning electron microscope. The surface microstructure was also examined. Independent samples t-test and Mann-Whitney U test were used to analyze the data. Maximum gap width and gap perimeter in the blood-exposed group were significantly larger than those in the STF-exposed group (p < 0.01). In the blood-exposed group, the crystals tended to be more rounded and less angular compared with the STF-exposed group, and there was a general lack of needle-like crystals. Exposure to blood during setting has a negative effect on marginal adaptation of MTA, and blood-exposed MTA has a different surface microstructure compared to STF-exposed MTA.

Pathologic margin involvement and the risk of recurrence in patients treated with breast-conserving therapy

International Nuclear Information System (INIS)

Gage, Irene; Nixon, Asa J.; Schnitt, Stuart J.; Recht, Abram; Gelman, Rebecca; Silver, Barbara; Connolly, James L.; Harris, Jay R.

1995-01-01

PURPOSE: To assess the relationship between microscopic margin status and recurrence after breast-conserving therapy for tumors with or without an extensive intraductal component (EIC). MATERIALS AND METHODS: During the years 1968 to 1986, 1865 women with unilateral clinical stage I or II breast cancer were treated with radiation therapy for breast conservation. Of these, 340 received ≥60 Gy to the tumor bed and had margins that were evaluable on review of their pathologic slides; these constitute the study population. The median follow-up was 109 months. All available slides were reviewed by one of the study pathologists (SS, JC). Final radial margins of excision were classified as negative >1 mm (no invasive or ductal carcinoma in-situ within 1 mm of the inked margin), negative ≤1 mm (any carcinoma ≤1 mm of the inked margin but not at ink) or positive (any carcinoma at the inked margin). A focally positive margin was defined as any invasive or in-situ carcinoma at the margin in ≤3 LPF. The extent of positivity was not evaluable in 2 patients and the distance of the tumor from the margin was not evaluable in 48 patients with a negative margin. Thirty-nine percent of EIC-negative and 46% of EIC-positive patients underwent a re-excision and, for these, the final margin analyzed was from the re-excised specimen. The median dose to the tumor bed was 63 Gy for patients with positive margins and 62 Gy for patients with negative margins. Recurrent disease was classified as ipsilateral breast recurrence (IBR) or distant metastasis/regional nodal failure (DM/RNF). RESULTS: Five year crude rates for the first site of recurrence were calculated for 340 patients evaluable at 5 years. Results were tabulated separately for all patients, EIC-negative and EIC-positive. All p-values tested for differences in the distribution of sites of first failure. CONCLUSIONS: The risk of ipsilateral breast recurrence is equally low for patients with close (≤1 mm) or negative (>1 mm

Assessment and Treatment of Paraphilias.

Science.gov (United States)

Seligman, Linda; Hardenburg, Stephanie A.

2000-01-01

Provides a description of the category of mental disorders called "paraphilias" and guidelines for assessment of people who present with paraphillic behavior. Includes a review of inventories that can facilitate diagnosis and description of paraphilias. Discusses effective approaches to treatment of these disorders as well as personal and…

Use of Respiratory-Correlated Four-Dimensional Computed Tomography to Determine Acceptable Treatment Margins for Locally Advanced Pancreatic Adenocarcinoma

International Nuclear Information System (INIS)

Goldstein, Seth D.; Ford, Eric C.; Duhon, Mario; McNutt, Todd; Wong, John; Herman, Joseph M.

2010-01-01

Purpose: Respiratory-induced excursions of locally advanced pancreatic adenocarcinoma could affect dose delivery. This study quantified tumor motion and evaluated standard treatment margins. Methods and Materials: Respiratory-correlated four-dimensional computed tomography images were obtained on 30 patients with locally advanced pancreatic adenocarcinoma; 15 of whom underwent repeat scanning before cone-down treatment. Treatment planning software was used to contour the gross tumor volume (GTV), bilateral kidneys, and biliary stent. Excursions were calculated according to the centroid of the contoured volumes. Results: The mean ± standard deviation GTV excursion in the superoinferior (SI) direction was 0.55 ± 0.23 cm; an expansion of 1.0 cm adequately accounted for the GTV motion in 97% of locally advanced pancreatic adenocarcinoma patients. Motion GTVs were generated and resulted in a 25% average volume increase compared with the static GTV. Of the 30 patients, 17 had biliary stents. The mean SI stent excursion was 0.84 ± 0.32 cm, significantly greater than the GTV motion. The xiphoid process moved an average of 0.35 ± 0.12 cm, significantly less than the GTV. The mean SI motion of the left and right kidneys was 0.65 ± 0.27 cm and 0.77 ± 0.30 cm, respectively. At repeat scanning, no significant changes were seen in the mean GTV size (p = .8) or excursion (p = .3). Conclusion: These data suggest that an asymmetric expansion of 1.0, 0.7, and 0.6 cm along the respective SI, anteroposterior, and medial-lateral directions is recommended if a respiratory-correlated four-dimensional computed tomography scan is not available to evaluate the tumor motion during treatment planning. Surrogates of tumor motion, such as biliary stents or external markers, should be used with caution.

Splenic marginal zone lymphoma: from genetics to management.

Science.gov (United States)

Arcaini, Luca; Rossi, Davide; Paulli, Marco

2016-04-28

Splenic marginal zone lymphoma (SMZL) is a rare B-cell malignancy involving the spleen, bone marrow, and frequently the blood. SMZL lymphomagenesis involves antigen and/or superantigen stimulation and molecular deregulation of genes (NOTCH2 and KLF2) involved in the physiological differentiation of spleen marginal zone B cells. Diagnosis requires either spleen histology or, alternatively, the documentation of a typical cell morphology and immunophenotype on blood cells coupled with the detection of intrasinusoidal infiltration by CD20(+) cells in the bone marrow. Among B-cell tumors, deletion of 7q and NOTCH2 mutations are almost specific lesions of SMZL, thus representing promising diagnostic biomarkers of this lymphoma. Although the majority of SMZLs show an indolent course with a median survival of approximately 10 years, nearly 30% of patients experience a poor outcome. No randomized trials are reported for SMZL, and few prospective trials are available. A watch-and-wait approach is advisable for asymptomatic patients. Treatment options for symptomatic patients ranges from splenectomy to rituximab alone or combined with chemotherapy. In some geographic areas, a subset of patients with SMZL associates with hepatitis C virus infection, prompting virus eradication as an effective lymphoma treatment. It would be worthwhile to explore deregulated cellular programs of SMZL as therapeutic targets in the future; improved clinical and biological prognostication will be essential for identifying patients who may benefit from novel approaches. © 2016 by The American Society of Hematology.

Impact of Close and Positive Margins in Transoral Laser Microsurgery for Tis-T2 Glottic Cancer.

Science.gov (United States)

Fiz, Ivana; Mazzola, Francesco; Fiz, Francesco; Marchi, Filippo; Filauro, Marta; Paderno, Alberto; Parrinello, Giampiero; Piazza, Cesare; Peretti, Giorgio

2017-01-01

Transoral laser microsurgery (TLM) represents one of the most effective treatment strategies for Tis-T2 glottic squamous cell carcinomas (SCC). The prognostic influence of close/positive margins is still debated, and the role of narrow band imaging (NBI) in their intraoperative definition is still to be validated on large cohort of patients. This study analyzed the influence of margin status on recurrence-free survival (RFS) and disease-specific survival (DSS). We retrospectively studied 507 cases of pTis-T1b (Group A) and 127 cases of pT2 (Group B) glottic SCC. We identified the following margin status: negative ( n  = 232), close superficial ( n  = 79), close deep (CD) ( n  = 35), positive single superficial ( n  = 146), positive multiple superficial ( n  = 94), and positive deep ( n  = 48) and analyzed their impact on RFS and DSS. Close margins were defined by tumor-margin distance <1 mm. Pre-TLM margins were defined by white light in 323 patients, whereas NBI was employed in 311 patients. In Group A, DSS and RFS were reduced in positive multiple superficial and positive deep margins (DSS = 96.1 and 97%, both p  < 0.05; RFS = 72%, p  < 0.001 and 75.8%, p  < 0.01). In Group B, DSS was reduced in positive multiple superficial margins (82.4%, p  < 0.05). RFS was reduced in positive single superficial, positive multiple superficial, and positive deep margins (62.5, 41.2, and 53.3%, p  < 0.01). In the entire population, RFS was reduced in CD margins (77.1%, p  < 0.05). Use of NBI led to improvement in RFS and DSS. The study indicates that close and positive single superficial margins do not affect DSS. By contrast, all types of margin positivity predict the occurrence of relapses, albeit with different likelihood, depending on stage/margin type. CD margins should be considered as a single risk factor. Use of NBI granted better intraoperative margins definition.

Professional Commitment and Professional Marginalism in Teachers

Directory of Open Access Journals (Sweden)

Kalashnikov A.I.

2017-11-01

Full Text Available The article reviews teachers' attitudes towards the teaching profession which can be expressed both in professional commitment and in professional marginalism. The dominance of professional marginalism could affect destructively the students as well as the teacher’s personality, hence the issues related to the content of personal position of a marginal and the rate of marginalism among teachers. It was suggested that marginalism could be revealed in the study of professional commitment. The study involved 81 teachers of Sverdlovsk secondary schools aged 21—60 years with work experience ranging from 1 month to 39 years. The Professional Commitment Questionnaire was used as the study technique. The results showed that negative emotional attitude towards the profession and reluctance to leave the profession were grouped as a separate factor. The dispersion factor was 12,5%. The factor loadings ranged from 0.42 to 0.84. The study proved that professional marginalism in teachers includes dissatisfaction with work, feelings of resentment against profession and an unwillingness to leave the profession.

A quantitative analysis of transtensional margin width

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Jeanniot, Ludovic; Buiter, Susanne J. H.

2018-06-01

Continental rifted margins show variations between a few hundred to almost a thousand kilometres in their conjugated widths from the relatively undisturbed continent to the oceanic crust. Analogue and numerical modelling results suggest that the conjugated width of rifted margins may have a relationship to their obliquity of divergence, with narrower margins occurring for higher obliquity. We here test this prediction by analysing the obliquity and rift width for 26 segments of transtensional conjugate rifted margins in the Atlantic and Indian Oceans. We use the plate reconstruction software GPlates (http://www.gplates.org) for different plate rotation models to estimate the direction and magnitude of rifting from the initial phases of continental rifting until breakup. Our rift width corresponds to the distance between the onshore maximum topography and the last identified continental crust. We find a weak positive correlation between the obliquity of rifting and rift width. Highly oblique margins are narrower than orthogonal margins, as expected from analogue and numerical models. We find no relationships between rift obliquities and rift duration nor the presence or absence of Large Igneous Provinces (LIPs).

Positive Margins by Oropharyngeal Subsite in Transoral Robotic Surgery for T1/T2 Squamous Cell Carcinoma.

Science.gov (United States)

Persky, Michael J; Albergotti, William G; Rath, Tanya J; Kubik, Mark W; Abberbock, Shira; Geltzeiler, Mathew; Kim, Seungwon; Duvvuri, Umamaheswar; Ferris, Robert L

2018-04-01

Objective To compare positive margin rates between the 2 most common subsites of oropharyngeal transoral robotic surgery (TORS), the base of tongue (BOT) and the tonsil, as well as identify preoperative imaging characteristics that predispose toward positive margins. Study Design Case series with chart review. Setting Tertiary care referral center. Subjects and Methods We compared the final and intraoperative positive margin rate between TORS resections for tonsil and BOT oropharyngeal squamous cell carcinoma (OPSCC), as well as the effect of margins on treatment. A blinded neuroradiologist examined the preoperative imaging of BOT tumors to measure their dimensions and patterns of spread and provided a prediction of final margin results. Results Between January 2010 and May 2016, a total of 254 patients underwent TORS for OPSCC. A total of 140 patients who underwent TORS for T1/T2 OPSCC met inclusion criteria. A final positive margin is significantly more likely for BOT tumors than tonsil tumors (19.6% vs 4.5%, respectively, P = .004) and likewise for intraoperative margins of BOT and tonsil tumors (35.3% vs 12.4%, respectively; P = .002). A positive final margin is 10 times more likely to receive chemoradiation compared to a negative margin, controlling for extracapsular spread and nodal status (odds ratio, 9.6; 95% confidence interval, 1.6-59.6; P = .02). Preoperative imaging characteristics and subjective radiologic examination of BOT tumors did not correlate with final margin status. Conclusion Positive margins are significantly more likely during TORS BOT resections compared to tonsil resections. More research is needed to help surgeons predict which T1/T2 tumors will be difficult to completely extirpate.

Marginal overweight operating scenario for DOE's initiative I highway casks

International Nuclear Information System (INIS)

Hill, C.V.; Loud, G.C.; Heitzman, A.C.

1993-01-01

This paper assesses the potential transport of high-capacity Initiative I highway casks under development by the Office of Civilian Radioactive Waste Management (OCRWM) as permitted marginal overweight shipments that: exceed a gross vehicle weight (gvw) limit of 80,000, but weight less than 96,000 pounds; follow axle and axle group weight limits adopted by the Surface Transportation Assistance Act (STAA) of 1982; conform to dimensional restrictions to operate on most major highways; and comply with the Federal Bridge Formula. The marginal overweight tractor-trailer would operate in normal open-quotes over-the-roadclose quotes mode and comply with all laws and regulations. The vehicle would have a sleeper berth and two drivers - one to drive while the other provides escort and communications services and accumulates required off-duty time

On the evaluation of marginal expected shortfall

DEFF Research Database (Denmark)

Caporin, Massimiliano; Santucci de Magistris, Paolo

2012-01-01

In the analysis of systemic risk, Marginal Expected Shortfall may be considered to evaluate the marginal impact of a single stock on the market Expected Shortfall. These quantities are generally computed using log-returns, in particular when there is also a focus on returns conditional distribution....... In this case, the market log-return is only approximately equal to the weighed sum of equities log-returns. We show that the approximation error is large during turbulent market phases, with a subsequent impact on Marginal Expected Shortfall. We then suggest how to improve the evaluation of Marginal Expected...

[Resection margins in conservative breast cancer surgery].

Science.gov (United States)

Medina Fernández, Francisco Javier; Ayllón Terán, María Dolores; Lombardo Galera, María Sagrario; Rioja Torres, Pilar; Bascuñana Estudillo, Guillermo; Rufián Peña, Sebastián

2013-01-01

Conservative breast cancer surgery is facing a new problem: the potential tumour involvement of resection margins. This eventuality has been closely and negatively associated with disease-free survival. Various factors may influence the likelihood of margins being affected, mostly related to the characteristics of the tumour, patient or surgical technique. In the last decade, many studies have attempted to find predictive factors for margin involvement. However, it is currently the new techniques used in the study of margins and tumour localisation that are significantly reducing reoperations in conservative breast cancer surgery. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

Assessing Treatment Outcomes in Attention-Deficit/Hyperactivity Disorder: A Narrative Review

Science.gov (United States)

Weiss, Margaret D.

2012-01-01

Objective: To review measures used to assess treatment response in patients with attention-deficit/hyperactivity disorder (ADHD) across the life span. Data Sources: Keyword searches of English-language articles in the PubMed database up to and including the May 4, 2011, index date were performed with the search strings (1) (attention deficit disorder with hyperactivity [MeSH] OR ADHD) AND (outcome assessment [MeSH] OR adaptation of life skills OR executive function [MeSH]) and (2) (attention deficit disorder with hyperactivity [MeSH] OR ADHD) AND (function OR functioning OR quality of life [MeSH]). Study Selection: Articles found through this search were then selected based on relevance to the topic area; no specific quality criteria were applied. Data Extraction: Narrative review. Results: The vast majority of studies assessing ADHD treatments have measured treatment response using ADHD symptom measures. Additional domains relevant for assessing treatment response among children and adults with ADHD include functional impairment, quality of life, adaptive life skills, and executive function. Validated rating scales exist for assessing these additional domains, but there has been minimal research evaluating the sensitivity of these instruments for detecting treatment response in pediatric and adult samples. Conclusions: Assessment of treatment outcomes in ADHD should move beyond symptom assessment to incorporate measures of functioning, quality of life, adaptive skills, and executive function, especially when assessing long-term treatment response. The authors recommend a potential battery and schedule of measures that could be used to more comprehensively assess treatment response in patients with ADHD. PMID:23585986

SU-E-P-40: Dosimetric Characteristics of Field Aperture Margin Design in Stereotactic Body Radiation Therapy (SBRT)

Energy Technology Data Exchange (ETDEWEB)

Zhu, J

2015-06-15

Purpose: To characterize the dosimetric effects of field aperture margin design in Stereotactic Body Radiation Therapy (SBRT). Methods: Three artificial spherical PTVs, with diameter of 10mm, 20mm and 30mm, were created on CT images of a human body thoracic phantom. Seven non-coplanar isocentric fields were used for treatment planning. For each PTV, treatment plans with margins 0mm, 1mm, 2mm and 3mm were planned. Dosimetric comparison among plans was done considering the following parameters: prescribed isodose line for target coverage, maximum dose, mean dose as well as dose spillages of V80, V50, and V20. Results: Corresponding to aperture margins of 0mm, 1mm,2m and 3mm used in the treatment planning, the percentage of isodose line chosen for dose prescription increases from 65% to 93% for 10mm PTV, 70% to 92% for 20mm PTV, and 75% to 92% for 30mm PTV. The maximum dose decrease accordingly from 155.7% to 109.5% for 10mm PTV, 145% to 111.6% for 20mm PTV, 137% to 112.2% for 30mm PTV. The mean dose decrease from 138.% to 104.4% for 10mm PTV, 122.8% to 106.1% for 20mm PTV, 121.3% to 106% for 30mm PTV. Dose spillages (mm3) increase (V80−2.6 to 4.02, V50−4.55 to 9.3, V20–87.86 to 101.71) for 10 mm PTV, (V80−6.78 to 9.89, V50–13.46 to 20.4, V20-119.16 to 219.1) for 20 mm PTV, (V80–22.01 to 28.59, V50–41.56 to 52.66, V20-532.71 to 551.84) for 30 mm PTV. Conclusion: In SBRT treatment planning, tight field aperture margin requires prescribing dose to lower isodose line that leading to higher dose inhomogeneity and higher mean dose to PTV. Loose margin allows prescribing dose to higher isodose line, therefore improves the dose homogeneity. However, it increases dose spillages. Clinician could try different margins according to the PTV size and location of surrounding critical organs to optimize the dose delivered to the patient.

Marginal vitamin A deficiency in pigs experimentally infected with Trichuris suis

DEFF Research Database (Denmark)

Pedersen, S; Saeed, I; Jensen, S K

2001-01-01

were marginally smaller (36.7 vs 40.2 mm; P = 0.08), more orally located (section 2.9 vs 3.9; P = 0.08) and had a higher proportion of males (0.58 vs 0.50; P = 0.08) whereas there were no effects of diet treatment on fecundity. The proportion of pigs with faecal T. suis egg excretion 12 weeks post...

Clinical Significance: a Therapeutic Approach Topsychological Assessment in Treatment Planning

Directory of Open Access Journals (Sweden)

Afolabi Olusegun Emmanuel

2015-06-01

Full Text Available Psychological assessment has long been reported as a key component of clinical psychology. This paper examines the complexities surrounding the clinical significance of therapeutic approach to treatment planning. To achieve this objective, the paper searched and used the PsycINFO and PubMed databases and the reference sections of chapters and journal articles to analysed, 1 a strong basis for the usage of therapeutic approach to psychological assessment in treatment plans, 2 explained the conceptual meaning of clinical significant change in therapeutic assessment, 3 answered some of the questions regarding practicability and the clinical significance of therapeutic approach to treatment plans, particularly during or before treatment, 4 linked therapeutic assessment to change in clients’ clinical impression, functioning and therapeutic needs 5 analysed the empirically documenting clinically significant change in therapeutic assessment. Finally, the study suggested that though therapeutic assessment is not sufficient for the systematic study of psychotherapy outcome and process, it is still consistent with both the layman and professional expectations regarding treatment outcome and also provides a precise method for classifying clients as ‘changed’ or ‘unchanged’ on the basis of clinical significance criteria.

Label-free optical imaging technologies for rapid translation and use during intraoperative surgical and tumor margin assessment

Science.gov (United States)

Boppart, Stephen A.; Brown, J. Quincy; Farah, Camile S.; Kho, Esther; Marcu, Laura; Saunders, Christobel M.; Sterenborg, Henricus J. C. M.

2018-02-01

The biannual International Conference on Biophotonics was recently held on April 30 to May 1, 2017, in Fremantle, Western Australia. This continuing conference series brought together key opinion leaders in biophotonics to present their latest results and, importantly, to participate in discussions on the future of the field and what opportunities exist when we collectively work together for using biophotonics for biological discovery and medical applications. One session in this conference, entitled "Tumor Margin Identification: Critiquing Technologies," challenged invited speakers and attendees to review and critique representative label-free optical imaging technologies and their application for intraoperative assessment and guidance in surgical oncology. We are pleased to share a summary in this outlook paper, with the intent to motivate more research inquiry and investigations, to challenge these and other optical imaging modalities to evaluate and improve performance, to spur translation and adoption, and ultimately, to improve the care and outcomes of patients.

Ferritin associates with marginal band microtubules

International Nuclear Information System (INIS)

Infante, Anthony A.; Infante, Dzintra; Chan, M.-C.; How, P.-C.; Kutschera, Waltraud; Linhartova, Irena; Muellner, Ernst W.; Wiche, Gerhard; Propst, Friedrich

2007-01-01

We characterized chicken erythrocyte and human platelet ferritin by biochemical studies and immunofluorescence. Erythrocyte ferritin was found to be a homopolymer of H-ferritin subunits, resistant to proteinase K digestion, heat stable, and contained iron. In mature chicken erythrocytes and human platelets, ferritin was localized at the marginal band, a ring-shaped peripheral microtubule bundle, and displayed properties of bona fide microtubule-associated proteins such as tau. Red blood cell ferritin association with the marginal band was confirmed by temperature-induced disassembly-reassembly of microtubules. During erythrocyte differentiation, ferritin co-localized with coalescing microtubules during marginal band formation. In addition, ferritin was found in the nuclei of mature erythrocytes, but was not detectable in those of bone marrow erythrocyte precursors. These results suggest that ferritin has a function in marginal band formation and possibly in protection of the marginal band from damaging effects of reactive oxygen species by sequestering iron in the mature erythrocyte. Moreover, our data suggest that ferritin and syncolin, a previously identified erythrocyte microtubule-associated protein, are identical. Nuclear ferritin might contribute to transcriptional silencing or, alternatively, constitute a ferritin reservoir

Optimal beam margins in linac-based VMAT stereotactic ablative body radiotherapy: a Pareto front analysis for liver metastases.

Science.gov (United States)

Cilla, Savino; Ianiro, Anna; Deodato, Francesco; Macchia, Gabriella; Digesù, Cinzia; Valentini, Vincenzo; Morganti, Alessio G

2017-11-27

We explored the Pareto fronts mathematical strategy to determine the optimal block margin and prescription isodose for stereotactic body radiotherapy (SBRT) treatments of liver metastases using the volumetric-modulated arc therapy (VMAT) technique. Three targets (planning target volumes [PTVs] = 20, 55, and 101 cc) were selected. A single fraction dose of 26 Gy was prescribed (prescription dose [PD]). VMAT plans were generated for 3 different beam energies. Pareto fronts based on (1) different multileaf collimator (MLC) block margin around PTV and (2) different prescription isodose lines (IDL) were produced. For each block margin, the greatest IDL fulfilling the criteria (95% of PTV reached 100%) was considered as providing the optimal clinical plan for PTV coverage. Liver D mean , V7Gy, and V12Gy were used against the PTV coverage to generate the fronts. Gradient indexes (GI and mGI), homogeneity index (HI), and healthy liver irradiation in terms of D mean , V7Gy, and V12Gy were calculated to compare different plans. In addition, each target was also optimized with a full-inverse planning engine to obtain a direct comparison with anatomy-based treatment planning system (TPS) results. About 900 plans were calculated to generate the fronts. GI and mGI show a U-shaped behavior as a function of beam margin with minimal values obtained with a +1 mm MLC margin. For these plans, the IDL ranges from 74% to 86%. GI and mGI show also a V-shaped behavior with respect to HI index, with minimum values at 1 mm for all metrics, independent of tumor dimensions and beam energy. Full-inversed optimized plans reported worse results with respect to Pareto plans. In conclusion, Pareto fronts provide a rigorous strategy to choose clinical optimal plans in SBRT treatments. We show that a 1-mm MLC block margin provides the best results with regard to healthy liver tissue irradiation and steepness of dose fallout. Copyright © 2017 American Association of Medical Dosimetrists

Methylation patterns in marginal zone lymphoma.

Science.gov (United States)

Arribas, Alberto J; Bertoni, Francesco

Promoter DNA methylation is a major regulator of gene expression and transcription. The identification of methylation changes is important for understanding disease pathogenesis, for identifying prognostic markers and can drive novel therapeutic approaches. In this review we summarize the current knowledge regarding DNA methylation in MALT lymphoma, splenic marginal zone lymphoma, nodal marginal zone lymphoma. Despite important differences in the study design for different publications and the existence of a sole large and genome-wide methylation study for splenic marginal zone lymphoma, it is clear that DNA methylation plays an important role in marginal zone lymphomas, in which it contributes to the inactivation of tumor suppressors but also to the expression of genes sustaining tumor cell survival and proliferation. Existing preclinical data provide the rationale to target the methylation machinery in these disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Limitations of ''margin'' in qualification tests

International Nuclear Information System (INIS)

Clough, R.L.; Gillen, K.T.

1984-01-01

We have carried out investigations of polymer radiation degradation behaviors which have brought to light a number of reasons why this concept of margin can break down. First of all, we have found that dose-rate effects vary greatly in magnitude. Thus, based on high dose-rate testing, poor materials with large dose-rate effects may be selected over better materials with small effects. Also, in certain cases, material properties have been found to level out (as with PVC) or reverse trend (as with buna-n) at high doses, so that ''margin'' may be ineffective, misleading, or counterproductive. For Viton, the material properties were found to change in opposite directions at high and low dose rates, making ''margin'' inappropriate. The underlying problem with the concept of ''margin'' is that differences in aging conditions can lead to fundamental differences in degradation mechanisms

Life Cycle Assessment of Daugavgriva Waste Water Treatment Plant

OpenAIRE

Romagnoli, F; Fraga Sampaio, F; Blumberga, D

2009-01-01

This paper presents the assessment of the environmental impacts caused by the treatment of Riga’s waste water in the Daugavgriva plant with biogas energy cogeneration through the life cycle assessment (LCA). The LCA seems to be a good tool to assess and evaluate the most serious environmental impacts of a facility The results showed clearly that the impact category contributing the most to the total impact –eutrophicationcomes from the wastewater treatment stage. Cl...

Silenced, Silence, Silent: Motherhood in the Margins

Science.gov (United States)

Carpenter, Lorelei; Austin, Helena

2007-01-01

This project explores the experiences of women who mother children with ADHD. The authors use the metaphor of the text and the margin. The text is the "motherhood myth" that describes a particular sort of "good" mothering. The margin is the space beyond that text. This marginal space is inhabited by some or all of the mothers they spoke with, some…

Seismic margins and calibration of piping systems

International Nuclear Information System (INIS)

Shieh, L.C.; Tsai, N.C.; Yang, M.S.; Wong, W.L.

1985-01-01

The Seismic Safety Margins Research Program (SSMRP) is a US Nuclear Regulatory Commission-funded, multiyear program conducted by Lawrence Livermore National Laboratory (LLNL). Its objective is to develop a complete, fully coupled analysis procedure for estimating the risk of earthquake-induced radioactive release from a commercial nuclear power plant and to determine major contributors to the state-of-the-art seismic and systems analysis process and explicitly includes the uncertainties in such a process. The results will be used to improve seismic licensing requirements for nuclear power plants. In Phase I of SSMRP, the overall seismic risk assessment methodology was developed and assembled. The application of this methodology to the seismic PRA (Probabilistic Risk Assessment) at the Zion Nuclear Power Plant has been documented. This report documents the method deriving response factors. The response factors, which relate design calculated responses to best estimate values, were used in the seismic response determination of piping systems for a simplified seismic probablistic risk assessment. 13 references, 31 figures, 25 tables

Assessment of margins with respect to pressurized thermal shock for the 3 loop plants of the French program

International Nuclear Information System (INIS)

Buchalet, C.; Haussaire, P.; Houssin, B.; Vagner, J.

1983-08-01

Presentation of the FRAMATOME and EDF program on pressurized thermal shock which objectives are to demonstrate that present and older French reactor vessels have adequate safety margins and to provide recommendations of feasible plant specific modifications, both technically and economically. Phase I consists in a thorough analysis of pressure and temperature transients that the R.P.V. beltine could undergo during plant operations; phase II is the fracture mechanics analysis; phase III estimates the safety margins available during normal, upset, emergency and faulted conditions

Influence of margin status and radiation on recurrence after radical hysterectomy in Stage IB cervical cancer

International Nuclear Information System (INIS)

Viswanathan, Akila N.; Lee, Hang; Hanson, Emily; Berkowitz, Ross S.; Crum, Christopher P.

2006-01-01

Purpose: To examine the relationship between margin status and local recurrence (LR) or any recurrence after radical hysterectomy (RH) in women treated with or without radiotherapy (RT) for Stage IB cervical carcinoma. Methods and Materials: This study included 284 patients after RH with assessable margins between 1980 and 2000. Each margin was scored as negative (≥1 cm), close (>0 and <1 cm), or positive. The outcomes measured were any recurrence, LR, and relapse-free survival. Results: The crude rate for any recurrence was 11%, 20%, and 38% for patients with negative, close, and positive margins, respectively. The crude rate for LR was 10%, 11%, and 38%, respectively. Postoperative RT decreased the rate of LR from 10% to 0% for negative, 17% to 0% for close, and 50% to 25% for positive margins. The significant predictors of decreased relapse-free survival on univariate analysis were the depth of tumor invasion (hazard ratio [HR] 2.14/cm increase, p = 0.007), positive margins (HR 3.92, p = 0.02), tumor size (HR 1.3/cm increase, p = 0.02), lymphovascular invasion (HR 2.19, p = 0.03), and margin status (HR 0.002/increasing millimeter from cancer for those with close margins, p = 0.03). Long-term side effects occurred in 8% after RH and 19% after RH and RT. Conclusion: The use of postoperative RT may decrease the risk of LR in patients with close paracervical margins. Patients with other adverse prognostic factors and close margins may also benefit from the use of postoperative RT. However, RT after RH may increase the risk of long-term side effects

Assessment of Submarine Slope Stability on the Continental Margin off SW Taiwan

Science.gov (United States)

Hsu, Huai-Houh; Dong, Jia-Jyun; Cheng, Win-Bin; Su, Chih-Chieh

2017-04-01

The abundant gas hydrate reservoirs are distributed in the southwest (SW) off Taiwan. To explore this new energy, geological methods were systematically used and mainly emphasized on the storage potential evaluation. On the other hand, the correlation between gas hydrate dissociation and submarine slope stability is also an important issue. In this study, three submarine profiles on the active and passive continental margin were selected and assessed their slope stabilities by considering two influence factors (seismic forces and number of sedimentary layers). The gravity corers obtained from these three sites (Xiaoliuqiu, Yuan-An Ridge, and Pointer Ridge) to conduct soil laboratory tests. The physical property tests and isotropically consolidated undrained (CIU) triaxial tests were carried out to establish reference properties and shear strength parameters. Before the stability analysis is performed, it is also necessary to construct the seabed profile. For each submarine profile, data from P-waves and from S-waves generated by P-S conversion on reflection from airgun shots recorded along one line of ocean bottom seismometers were used to construct 2-D velocity sections. The seabed strata could be simplified to be only one sedimentary layer or to be multilayer in accordance with the velocity structure profile. Results show the safety factors (FS) of stability analysis are obviously different in considering the number of sedimentary layers, especially for a very thin layer of sediments on a steep slope. The simplified strata condition which treated all seabed strata as only one sedimentary layer might result in the FS lower than 1 and the slope was in an unstable state. On the contrary, the FS could be higher than 10 in a multilayer condition.

Significance and management of positive surgical margins at the time of radical prostatectomy.

Science.gov (United States)

Silberstein, Jonathan L; Eastham, James A

2014-10-01

Positive surgical margins (PSM) at the time of radical prostatectomy (RP) result in an increased risk of biochemical recurrence (BCR) and secondary treatment. We review current literature with a focus on stratifying the characteristics of the PSM that may define its significance, the impact of modern imaging and surgical approaches in avoidance of PSM, and management strategies when PSM do occur. We performed a review of the available literature to identify factors associated with PSM and their management. PSM have been repeatedly demonstrated to be associated with an increased risk of BCR following RP. The specific characteristics (size, number, location, Gleason score at the margin) of the PSM may influence the risk of recurrence. Novel imaging and surgical approaches are being investigated and may allow for reductions of PSM in the future. The use of adjuvant treatment for a PSM remains controversial and should be decided on an individual basis after a discussion about the risks and benefits. The goal of RP is complete resection of the tumor. PSM are associated with increased risk of BCR and secondary treatments. Of the risk factors associated with BCR after RP, a PSM is directly influenced by surgical technique.

Significance and management of positive surgical margins at the time of radical prostatectomy

Directory of Open Access Journals (Sweden)

Jonathan L. Silberstein

2014-01-01

Full Text Available Positive surgical margins (PSM at the time of radical prostatectomy (RP result in an increased risk of biochemical recurrence (BCR and secondary treatment. We review current literature with a focus on stratifying the characteristics of the PSM that may define its significance, the impact of modern imaging and surgical approaches in avoidance of PSM, and management strategies when PSM do occur. We performed a review of the available literature to identify factors associated with PSM and their management. PSM have been repeatedly demonstrated to be associated with an increased risk of BCR following RP. The specific characteristics (size, number, location, Gleason score at the margin of the PSM may influence the risk of recurrence. Novel imaging and surgical approaches are being investigated and may allow for reductions of PSM in the future. The use of adjuvant treatment for a PSM remains controversial and should be decided on an individual basis after a discussion about the risks and benefits. The goal of RP is complete resection of the tumor. PSM are associated with increased risk of BCR and secondary treatments. Of the risk factors associated with BCR after RP, a PSM is directly influenced by surgical technique.

Aspects of marginal expenditures in energy sector

International Nuclear Information System (INIS)

Stojchev, D.; Kynev, K.

1994-01-01

Technical and economical problems of marginal analysis methodology, its application procedure in energy sector and marginal expenditures determination are outlined. A comparative characteristics of the application is made for different periods of time. The differences in calculation of the marginal expenditures and prices are discussed. The operational costs, investments and inflation are analyzed. The mechanism of application of this approach in different planing horizon is outlined. The role of the change in the costs in time, the time unit, volume, the scope of application, etc. are determined. The areas of transition from one to other form of marginal expenditures are shown. 4 refs. (orig.)

Characterizing entanglement with global and marginal entropic measures

International Nuclear Information System (INIS)

Adesso, Gerardo; Illuminati, Fabrizio; De Siena, Silvio

2003-01-01

We qualify the entanglement of arbitrary mixed states of bipartite quantum systems by comparing global and marginal mixednesses quantified by different entropic measures. For systems of two qubits we discriminate the class of maximally entangled states with fixed marginal mixednesses, and determine an analytical upper bound relating the entanglement of formation to the marginal linear entropies. This result partially generalizes to mixed states the quantification of entanglement with marginal mixednesses holding for pure states. We identify a class of entangled states that, for fixed marginals, are globally more mixed than product states when measured by the linear entropy. Such states cannot be discriminated by the majorization criterion

Steel Industry Marginal Opportunity Analysis

Energy Technology Data Exchange (ETDEWEB)

none,

2005-09-01

The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

Steep microbial boundstone-dominated plaform margins

NARCIS (Netherlands)

Kenter, J.A.M.; Harris, P.M.; Della Porta, G.P.

2005-01-01

Seaward progradation of several kilometers has been documented mostly for leeward margin low-angle carbonate slope systems with a dominant platform top sediment source. However, steep and high-relief margins fronting deep basins can also prograde and as such are somewhat perplexing. Characteristics

Comparative analysis of intraoral radiographs with variation of tube angulation to detect insufficient crown margins.

Science.gov (United States)

Sailer, Benjamin F; Geibel, Margrit-Ann

2013-01-01

Variations in angulation of the x-ray tube affect the appearance of insufficient approximal crown margins on intraoral radiographs. This study examines the impact of such angular variation on the assessment of digital radiographs using three different X-ray tubes--Heliodent DS (Sirona), Gendex Expert DC (KaVo Dental) and Focus (KaVo Dental)--as well as the Gendex Visualix eHD CCD sensor (KaVo Dental). The test specimens, crowned teeth 46 from two mandibles provided by the Institute of Anatomy and Cell Biology, were examined with each tube. The results indicate great differences in the angles indicative of insufficient crown margins on X-ray images. Because of beam divergence and the crown marginal gap, the length and width of which frequently varies, it is difficult to infer any optimum angle from the data. This leads to the conclusion that at present, it is not possible to establish ideal angles for visualization of insufficient approximal crown margins.

Safety margins and retrofit. The technical calculation perspective; Sicherheitsmargen durch Nachruestung aus Sicht der technischen Berechnung

Energy Technology Data Exchange (ETDEWEB)

Daichendt, Matthias [Kraftanlagen Heidelberg GmbH, Heidelberg (Germany). Systemtechnik - Technische Berechnungen

2016-01-15

Safety margins are an essential factor of the safety philosophy for nuclear power plants. They support to cover future requirements even today. The basic safety concept is one key topic as also aspects of process engineering, the dimensioning and mechanical analysis of systems and ageing management. Calculations with today's capabilities are an integral part of the determination of safety margins. They can be used to analyse and to assess retrofit measures.

Conference Report: The New Discovery of Margins: Theory-Based Excursions in Marginal Social Fields

OpenAIRE

Kirchner, Babette; Lorenzen, Jule-Marie; Striffler, Christine

2014-01-01

At this year's spring conference of the Sociology of Knowledge Section of the German Sociological Association, a diverse range of theoretical concepts and multiple empirical insights into different marginal social fields were presented. As in everyday life, drawing a line between center and margin can be seen as an important challenge that must equally be faced in sociology. The socially constructed borderline appears to be highly variable. Therefore it has to be delineated or fixed somehow. ...

4D planning over the full course of fractionation: assessment of the benefit of tumor trailing

Science.gov (United States)

McQuaid, D.; Bortfeld, T.

2011-11-01

Tumor trailing techniques have been proposed as a method of reducing the problem of intrafraction motion in radiotherapy. However the dosimetric assessment of trailing strategies is complicated by the requirement to study dose deposition over a full fraction delivery. Common 4D planning strategies allowing assessment of dosimetric motion effects study a single cycle acquired with 4DCT. In this paper, a methodology to assess dose deposited over an entire treatment course is advanced and used to assess the potential benefit of tumor trailing strategies for lung cancer patients. Two digital phantoms mimicking patient anatomy were each programmed to follow the tumor respiratory trajectory observed from 33 lung cancer patients. The two phantoms were designed to represent the cases of a small (volume = 13.6 cm3) and large (volume = 181.7 cm3) lung lesion. Motion margins required to obtain CTV coverage by 95% of the prescription dose to 90% of the available cases were computed for a standard treatment strategy and a trailing treatment strategy. The trailing strategy facilitated a margin reduction of over 30% relative to the conventional delivery. When the dose was computed across the entire delivery for the 33 cases, the trailing strategy was found to significantly reduce the underdosage to the outlier cases and the reduced trailing margin facilitated a 15% (small lesion) and 4% (large lesion) reduction for the mean lung dose and 7% (small lesion) and 10% (large lesion) for the mean esophagus dose. Finally, for comparison an ideal continuous tracking strategy was assessed and found to further reduce the mean lung and esophagus dose. However, this improvement comes at the price of increased delivery complexity and increased reliance on tumor localization accuracy.

4D planning over the full course of fractionation: assessment of the benefit of tumor trailing

International Nuclear Information System (INIS)

McQuaid, D; Bortfeld, T

2011-01-01

Tumor trailing techniques have been proposed as a method of reducing the problem of intrafraction motion in radiotherapy. However the dosimetric assessment of trailing strategies is complicated by the requirement to study dose deposition over a full fraction delivery. Common 4D planning strategies allowing assessment of dosimetric motion effects study a single cycle acquired with 4DCT. In this paper, a methodology to assess dose deposited over an entire treatment course is advanced and used to assess the potential benefit of tumor trailing strategies for lung cancer patients. Two digital phantoms mimicking patient anatomy were each programmed to follow the tumor respiratory trajectory observed from 33 lung cancer patients. The two phantoms were designed to represent the cases of a small (volume = 13.6 cm 3 ) and large (volume = 181.7 cm 3 ) lung lesion. Motion margins required to obtain CTV coverage by 95% of the prescription dose to 90% of the available cases were computed for a standard treatment strategy and a trailing treatment strategy. The trailing strategy facilitated a margin reduction of over 30% relative to the conventional delivery. When the dose was computed across the entire delivery for the 33 cases, the trailing strategy was found to significantly reduce the underdosage to the outlier cases and the reduced trailing margin facilitated a 15% (small lesion) and 4% (large lesion) reduction for the mean lung dose and 7% (small lesion) and 10% (large lesion) for the mean esophagus dose. Finally, for comparison an ideal continuous tracking strategy was assessed and found to further reduce the mean lung and esophagus dose. However, this improvement comes at the price of increased delivery complexity and increased reliance on tumor localization accuracy.

Evaluating the marginal utility principle for long-term hydropower scheduling

International Nuclear Information System (INIS)

Zhao, Tongtiegang; Zhao, Jianshi; Liu, Pan; Lei, Xiaohui

2015-01-01

Highlights: • Analysis of one-, two- and multi-period hydropower scheduling. • Derivation of marginal cost and marginal return of carry-over storage. • Evaluation of the marginal utility principle in a case study of the Three Gorges Reservoir. - Abstract: The conversion of the potential energy of dammed water into hydropower depends on both reservoir storage and release, which are the major difficulties in hydropower reservoir operation. This study evaluates the marginal utility principle, which determines the optimal carry-over storage between periods, for long-term hydropower scheduling. Increasing marginal cost and decreasing marginal return are two important characteristics that determine the marginal utility principle in water supply. However, the notion of decreasing marginal return is inapplicable in hydropower scheduling. Instead, the carry-over storage from one period has an increasing marginal contribution to the power generation in the next period. Although carry-over storage incurs an increasing marginal cost to the power generation in the current period, the marginal return is higher than the marginal cost. The marginal return from the carry-over storage further increases in the multi-period case. These findings suggest saving as much carry-over storage as possible, which is bounded by the operational constraints of storage capacity, environmental flow, and installed capacity in actual hydropower scheduling. The marginal utility principle is evaluated for a case study of the Three Gorges Reservoir, and the effects of the constraints are discussed. Results confirm the theoretical findings and show that the marginal return from carry-over storage is larger than the marginal cost. The operational constraints help determine the optimal carry-over storage.

Necessidade de tratamento periodontal avaliada pelo CPITN e sua relação com a qualidade de acabamento cervical das restaurações Need for periodontal treatment evaluated through CPITN and its relation to the quality of the cervical margin of restorations

Directory of Open Access Journals (Sweden)

Getúlio da Rocha NOGUEIRA-FILHO

2001-03-01

Full Text Available Irregularidades do acabamento cervical de restaurações constituem fatores de retenção de placa bacteriana, dificultando o controle de placa pelos procedimentos habituais de higiene bucal, favorecendo o desenvolvimento da doença periodontal. O objetivo deste estudo foi avaliar as condições periodontais e a necessidade de tratamento em função do acabamento cervical de restaurações dentais. Foram examinados 367 dentes restaurados com classes II e V de amálgama, classe III em resina, restauração metálica fundida e próteses unitárias. Utilizando-se sonda periodontal (OMS, verificou-se a posição do término da restauração (supragengival, subgengival ou ao nível da margem gengival; a qualidade das restaurações (falta ou excesso de material restaurador e a presença de grau 2 do CPITN. Após a análise dos dados, foi possível concluir que: 1 o término supragengival ofereceu a melhor adaptação marginal e a menor freqüência de grau 2 do CPITN; 2 a falta ou excesso de material restaurador favorecem o desenvolvimento de grau 2, independentemente do material utilizado e 3 nos términos subgengivais, foi maior a freqüência de adaptação marginal incorreta, principalmente casos de excesso de material restaurador, sendo estes casos de maior ocorrência de grau 2 do CPITN.Irregularities of the cervical margin of restorations facilitate the retention of bacterial plaque, hindering plaque control through the habitual procedures of oral hygiene and favoring the development of periodontal disease. The aim of this study was to evaluate the periodontal condition and treatment needs (applying CPITN in relation to the cervical margin of dental restorations. Three hundred and sixty-seven teeth with class II and V cavities restored with amalgam, class III cavities restored with composite resin, cast metal restorations and unitary prostheses were examined. With a WHO periodontal probe, the position of the cervical margins of restorations

Assessing the relationship between child sexual abuse and marginal living conditions on HIV/AIDS-related risk behavior among women prisoners.

Science.gov (United States)

Mullings, J L; Marquart, J W; Brewer, V E

2000-05-01

There were two aims in this research. First, to examine the relationships between childhood sexual abuse and HIV drug and sexual risk taking behaviors among female prisoners, and second, to examine the relationship between a marginal adult living context and HIV drug and sexual risk taking behavior among female prisoners. The data were collected through face-to-face interviews with a random sample of 500 women at admission to prison in 1994. Differences between women who were sexually abused while growing up (n = 130) were compared to women who reported no sexual abuse (n = 370) along various demographic, and HIV drug and sexual risk taking dimensions. A history of sexual abuse while growing up was associated with increased sexual risk taking behaviors in adulthood. A marginal adult living situation also emerged as an important factor increasing the risk for HIV infection. Examining the co-occurrence of both childhood sexual abuse and adult marginal living context revealed a strong relationship between these two factors and HIV risk taking activities. The findings indicate that childhood sexual abuse may be a predictor for HIV sexual risk taking behaviors among incarcerated women. The marginal and chaotic adult living style of these women was also associated the extent of their HIV drug and sexual risk taking behaviors. Our research suggests that the co-occurrence of sexual victimization and marginality is a stronger predictor of HIV risk than each variable alone.

Marginal and internal fit of nano-composite CAD/CAM restorations

Directory of Open Access Journals (Sweden)

So-Hyun Park

2016-02-01

Full Text Available Objectives The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. Materials and Methods A full veneer crown and an mesio-occluso-distal (MOD inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU and experimental nano-composite CAD/CAM blocks (EB under the same milling parameters. To assess the marginal and internal fit, the restorations were cemented to replicas and were embedded in an acrylic mold for sectioning at 0.5 mm intervals. The measured gap data were pooled according to the block types and measuring points for statistical analysis. Results Both the block type and measuring point significantly affected gap values, and their interaction was significant (p = 0.000. In crowns and inlays made from the two blocks, gap values were significantly larger in the occlusal area than in the axial area, while gap values in the marginal area were smallest (p < 0.001. Among the blocks, the restorations milled from EB had a significantly larger gap at all measuring points than those milled from LU (p = 0.000. Conclusions The marginal and internal gaps of the two nano-composite CAD/CAM blocks differed according to the measuring points. Among the internal area of the two nano-composite CAD/CAM restorations, occlusal gap data were significantly larger than axial gap data. The EB crowns and inlays had significantly larger gaps than LU restorations.

Community mapping of sex work criminalization and violence: impacts on HIV treatment interruptions among marginalized women living with HIV in Vancouver, Canada.

Science.gov (United States)

Goldenberg, Shira M; Deering, Kathleen; Amram, Ofer; Guillemi, Silvia; Nguyen, Paul; Montaner, Julio; Shannon, Kate

2017-09-01

Despite the high HIV burden faced by sex workers, data on access and retention in antiretroviral therapy (ART) are limited. Using an innovative spatial epidemiological approach, we explored how the social geography of sex work criminalization and violence impacts HIV treatment interruptions among sex workers living with HIV in Vancouver over a 3.5-year period. Drawing upon data from a community-based cohort (AESHA, 2010-2013) and linked external administrative data on ART dispensation, GIS mapping and multivariable logistic regression with generalized estimating equations to prospectively examine the effects of spatial criminalization and violence near women's places of residence on 2-day ART interruptions. Analyses were restricted to 66 ART-exposed women who contributed 208 observations and 83 ART interruption events. In adjusted multivariable models, heightened density of displacement due to policing independently correlated with HIV treatment interruptions (AOR: 1.02, 95%CI: 1.00-1.04); density of legal restrictions (AOR: 1.30, 95%CI: 0.97-1.76) and a combined measure of criminalization/violence (AOR: 1.00, 95%CI: 1.00-1.01) were marginally correlated. The social geography of sex work criminalization may undermine access to essential medicines, including HIV treatment. Interventions to promote 'enabling environments' (e.g. peer-led models, safer living/working spaces) should be explored, alongside policy reforms to ensure uninterrupted treatment access.

From Borders to Margins

DEFF Research Database (Denmark)

Parker, Noel

2009-01-01

of entities that are ever open to identity shifts.  The concept of the margin possesses a much wider reach than borders, and focuses continual attention on the meetings and interactions between a range of indeterminate entities whose interactions may determine both themselves and the types of entity...... upon Deleuze's philosophy to set out an ontology in which the continual reformulation of entities in play in ‘post-international' society can be grasped.  This entails a strategic shift from speaking about the ‘borders' between sovereign states to referring instead to the ‘margins' between a plethora...

Mental Depreciation and Marginal Decision Making

Science.gov (United States)

Heath; Fennema

1996-11-01

We propose that individuals practice "mental depreciation," that is, they implicitly spread the fixed costs of their expenses over time or use. Two studies explore how people spread fixed costs on durable goods. A third study shows that depreciation can lead to two distinct errors in marginal decisions: First, people sometimes invest too much effort to get their money's worth from an expense (e.g., they may use a product a lot to spread the fixed expense across more uses). Second, people sometimes invest too little effort to get their money's worth: When people add a portion of the fixed cost to the current costs, their perceived marginal (i.e., incremental) costs exceed their true marginal costs. In response, they may stop investing because their perceived costs surpass the marginal benefits they are receiving. The latter effect is supported by two field studies that explore real board plan decisions by university students.

Prosthodontic rehabilitation of patient with marginal mandibular resection using attachment supported prostheses: A clinical report

Directory of Open Access Journals (Sweden)

Kailas Mundhe

2014-01-01

Full Text Available Marginal mandibular resection to treat neoplasms leads to loss of alveolar bone and teeth at the affected side. Consequently patient suffers with poor masticatory performance and esthetic disfigurement, which we need to restore with the help of prosthodontic rehabilitation. The success of rehabilitation of these patients depends on strategic treatment planning and choice of most suitable treatment modality. In this article, case of a patient has been presented who underwent marginal mandibular resection and reported with many limiting factors like obliterated buccal and lingual sulci, attachment of lingual frenum and lower lip at the level of alveolar ridge and Macroglossia. Impression making and fabrication of a retentive prosthesis were the main challenges. Therefore, a modified impression technique was used to fabricate mandibular cast partial denture with extracoronal semi precision attachments to enhance the retention of the prosthesis.

Marginal and Interaction Effects in Ordered Response Models

OpenAIRE

Debdulal Mallick

2009-01-01

In discrete choice models the marginal effect of a variable of interest that is interacted with another variable differs from the marginal effect of a variable that is not interacted with any variable. The magnitude of the interaction effect is also not equal to the marginal effect of the interaction term. I present consistent estimators of both marginal and interaction effects in ordered response models. This procedure is general and can easily be extended to other discrete choice models. I ...

Substance abuse as a way of life in marginalized gender identity disorder: a case report with review of Indian literature.

Science.gov (United States)

Goyal, Shrigopal; Deb, Koushik Sinha; Elawadhi, Deeksha; Kaw, Nanaji

2014-12-01

Persons suffering from gender identity disorder (GID) are often severely marginalized in India and mostly live outside the society as a part of a minority community called the Hijras. Although substance abuse is considered a way of life in them, such patients rarely seek treatment because of the stigma and fear of discrimination. We report a case of GID presenting to tertiary care centre for treatment of multiple substance use dependence (SUD). The case is the first to highlight the use and dependence of multiple substances in the Hijra community of India. Further, the case emphasizes that SUD treatment might be a worthwhile intervention to bring such marginalized population under treatment, when further complicated issues on gender identity can be addressed. Copyright © 2014. Published by Elsevier B.V.

Sealing of minimally invasive Class II fillings (slot) using an adhesive patch: sealant margin extension for prevention.

Science.gov (United States)

Schmidlin, Patrick R; Seemann, Rainer; Filli, Tilla; Attin, Thomas; Imfeld, Thomas

2007-01-01

A laboratory study was performed to assess the potential of an adhesive patch to seal small, unbeveled, Class II, box-only (slot) composite fillings. After minimal access cavity preparation with an 80 pm diamond bur, 40 box-only Class II cavities were prepared mesially and distally in 20 extracted human molars using a u-shaped PCS insert (EMS). One cavity per tooth was adhesively filled with a hybrid composite material in one increment. A patch, acting as an adhesive matrice, was applied to the other cavity of each tooth to seal the restoration. The margin of the patch was located in areas easily accessible to oral hygiene measures and self-cleaning. All the teeth were subjected to thermo-mechanical stress in a computer-controlled masticator device. In 10 teeth, caries was induced in a microbial-based artificial mouth model and quantitatively determined by confocal laser scanning microscopy. Microleakage was assessed in the other 10 teeth in two planar sections after immersion in 0.5% basic fuchsin solution. The results showed no demineralization at the filling margins protected with the patch. Microleakage was observed in one sample only and was limited to the enamel. In contrast, the margins of fillings without the patch application showed a mean demineralization depth of 146 +/- 42 microm and dye penetration into the dentin in five sections. This innovative approach to sealing restorative margins with an adhesive patch results in less leakage and filling margin demineralization and merits further investigation.

Riverine transport of terrestrial organic matter to the North Catalan margin, NW Mediterranean Sea

Science.gov (United States)

Sanchez-Vidal, Anna; Higueras, Marina; Martí, Eugènia; Liquete, Camino; Calafat, Antoni; Kerhervé, Philippe; Canals, Miquel

2013-11-01

Rivers are the primary pathway for organic matter transport from the terrestrial to the marine environment and, thus, river fluxes are critical in regulating the quantity of terrestrial organic matter that reaches the coastal ecosystems. Hydrodynamic processes typical of the coastal zone can lead to the transport of terrestrial organic matter across the continental shelf and beyond. Such organic matter can eventually reach the deep margin and basin ecosystems. Riverine inputs of organic matter to the sea can be a significant food source to marine ecosystems contributing to carbon cycling in these ecosystems. In order to assess the marine carbon cycle it is essential to know the biogeochemical characteristics and temporal dynamics of the fluvial organic matter input discharged by rivers to the coastal zone. In this study we present a one and a half year long (November 2008 to May 2010) assessment on organic carbon (OC) and nitrogen (N) inputs from the three main rivers discharging into the North Catalan margin (Tordera, Ter and Fluvià, from south to north). Furthermore, we investigate the characteristics of the particulate organic matter discharged by these rivers by means of stable isotopic (δ13C and δ15N) and grain size analyses. We found that the hydrological regime of the rivers is a relevant factor in regulating the quantity and mediating the quality of organic matter inputs to the North Catalan margin. Overall, the three main rivers discharging into the study area deliver 1266 and 159 tonnes of terrestrial OC and N per year, respectively, to the coastal zone. Most of the OC and N load is transported during floods, which indicates that the Mediterranean climate of the area, with a strong seasonal contrast in precipitation, determines the timing of the main inputs of OC and N to the sea. Therefore, the annual OC and N load experiences a high temporal variability associated to the number and magnitude of floods with in each hydrological year. In addition, we

Handheld optical coherence tomography-reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

Science.gov (United States)

Iftimia, Nicusor; Yélamos, Oriol; Chen, Chih-Shan J.; Maguluri, Gopi; Cordova, Miguel A.; Sahu, Aditi; Park, Jesung; Fox, William; Alessi-Fox, Christi; Rajadhyaksha, Milind

2017-07-01

We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin in vivo. A standard OCT approach (spectrometer-based) with a central wavelength of 1310 nm and 0.11 numerical aperture (NA) was combined with a standard RCM approach (830-nm wavelength and 0.9 NA) into a common path hand-held probe. Cross-sectional OCT images and enface RCM images are simultaneously displayed, allowing for three-dimensional microscopic assessment of tumor morphology in real time. Depending on the subtype and depth of the BCC tumor and surrounding skin conditions, OCT and RCM imaging are able to complement each other, the strengths of each helping overcome the limitations of the other. Four representative cases are summarized, out of the 15 investigated in a preliminary pilot study, demonstrating how OCT and RCM imaging may be synergistically combined to more accurately detect BCCs and more completely delineate margins. Our preliminary results highlight the potential benefits of combining the two technologies within a single probe to potentially guide diagnosis as well as treatment of BCCs.

Response assessment with the CXCR4-directed positron emission tomography tracer [68Ga]Pentixafor in a patient with extranodal marginal zone lymphoma of the orbital cavities.

Science.gov (United States)

Herhaus, Peter; Habringer, Stefan; Vag, Tibor; Steiger, Katja; Slotta-Huspenina, Julia; Gerngroß, Carlos; Wiestler, Benedikt; Wester, Hans-Jürgen; Schwaiger, Markus; Keller, Ulrich

2017-12-01

CXCR4 belongs to the family of chemokine receptors. Together with its sole known ligand CXCL12 (SDF-1alpha), it has a pivotal role during organogenesis and for homing of hematopoietic stem cells. CXCR4 is overexpressed in various malignancies, and this is often associated with poor prognosis. Therefore, molecular imaging of CXCR4 bears a great potential for diagnostics and selecting patients for CXCR4-directed therapies. The CXCR4-directed positron emission tomography (PET) tracer [ 68 Ga]Pentixafor has been shown to visualize CXCR4 expression in various malignancies in vivo. Whereas this tracer has limitations compared to 18 F-Fluorodeoxyglucose ([ 18 F]FDG) in diagnostic PET imaging in peripheral tumour lesions, it might add valuable information in routine diagnostics and response assessment of tumours in close proximity to the central nervous system (CNS) and malignancies within this organ. As a proof-of-concept, we performed [ 68 Ga]Pentixafor PET imaging in a patient with extranodal marginal zone lymphoma (MZL) of the orbital cavities at diagnosis and for post-therapy response assessment. Compared to routinely conducted [ 18 F]FDG PET, the lymphoma lesions determined by magnetic resonance imaging (MRI) showed high tracer accumulation at diagnosis, which decreased upon treatment. We therefore propose that imaging of CXCR4 with [ 68 Ga]Pentixafor is a potential diagnostic tool for tumours close to or within the CNS and suggest this being studied in clinical trials.

Number of fragments, margin status and thermal artifacts of conized specimens from LLETZ surgery to treat cervical intraepithelial neoplasia.

Science.gov (United States)

Bittencourt, Dulcimary Dias; Zanine, Rita Maira; Sebastião, Ana Martins; Taha, Nabiha Saadi; Speck, Neila Góis; Ribalta, Julisa Chamorro Lascasas

2012-01-01

Large loop excision of the transformation zone (LLETZ) is a nontraumatic cut and coagulation method with several advantages, but it induces thermal artifacts in the cut region. The aim here was to assess the correlations of age, number of fragments, lesion grade and degree of thermal artifacts with margin quality in conized specimens from LLETZ for cervical intraepithelial neoplasia (CIN). Cross-sectional study at Universidade Federal de São Paulo (Unifesp). The records and histopathology findings of 118 women who underwent LLETZ between 1999 and 2007 were reviewed. Age, number of fragments, lesion grade, degree of thermal artifacts and margin quality were assessed. The patients' mean age was 27.14 years; 63.6% had been diagnosed with CIN II and 36.4% with CIN III. The lesion was removed as a single fragment in 79.6% of the cases. The margins were free from intraepithelial neoplasia in 85.6% and compromised in the endocervical margin in 6.8%. Fragment damage due to artifacts occurred in 2.5%. Severe artifacts occurred in 22.8%. Women aged 30 years or over presented more cases of CIN III (P < 0.0004). Neoplastic compromising of surgical margins and severe artifacts occurred more often in cases in which two or more fragments were removed, and in patients aged 30 years or over. CIN III in women aged 30 or over, when removed in two or more fragments during LLETZ, presented a greater number of compromised margins and greater severity of thermal artifacts.

Effect of Blood Contamination on Marginal Adaptation and Surface Microstructure of Mineral Trioxide Aggregate: A SEM Study

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Amin Salem Milani

2013-08-01

Full Text Available Background and aims. In various clinical situations, mineral trioxide aggregate (MTA may come into direct contact or even be mixed with blood. The aim of the present study was to evaluate the effect of exposure to blood on marginal adaptation and surface microstructure of MTA. Materials and methods. Thirty extracted human single-rooted teeth were used. Standard root canal treatment was carried out. Root-ends were resected, and retrocavities were prepared. The teeth were randomly divided into two groups (n = 15: in group 1, the internal surface of the cavities was coated with fresh blood. Then, the cavities were filled with MTA. The roots were immersed in molds containing fresh blood. In group 2, the aforementioned procedures were performed except that synthetic tissue fluid (STF was used instead of blood. To assess the marginal adaptation, “gap perimeter” and “maximum gap width” were measured under scanning electron microscope. The surface microstructure was also examined. Independent samples t-test and Mann-Whitney U test were used to analyze the data. Results. Maximum gap width and gap perimeter in the blood-exposed group were significantly larger than those in the STF-exposed group (p < 0.01. In the blood-exposed group, the crystals tended to be more rounded and less angular compared with the STF-exposed group, and there was a general lack of needle-like crystals. Conclusion. Exposure to blood during setting has a negative effect on marginal adaptation of MTA, and blood-exposed MTA has a different surface microstructure compared to STF-exposed MTA.

Inter-treatment compensation of treatment setup variation to enhance the radiotherapeutic ratio

International Nuclear Information System (INIS)

Di, Yan; John, Wong; Michalski, Jeff; Pan, Cheng; Frazier, Arthur; Bosch, Walter; Martinez, Alvaro

1995-01-01

Purpose: In radiotherapy, treatment setup error has been one of the major causes of dose variation in the treated volume. With the data acquired from on-line electronic portal imaging, it is now possible not only to adjust the patient setup, but also to modify the treatment plan during the course of clinical treatment based on the setup error measured for each individual patient. In this work, daily clinical portal images were retrospectively analyzed to study (1) the number of initial daily portal images required to give adequate prediction of the systematic and random deviations of treatment setup, and (2) the potential therapeutic gain when the inter-treatment planning modification was established using the setup error of each individual patient. Methods and Materials: Only those patients whose treatment positions had not been adjusted during the course of treatment were selected for the retrospective study. Daily portal images of 27 lung, 25 pelvis, and 12 head and neck (h and n) cancer patients were obtained from two independent clinics with similar setup procedures. The anterior-to-posterior field was analyzed for the pelvis and lung treatments, and the right lateral field for the h and n treatments. Between 13 to 30 daily portal images were acquired for each patient and were analyzed using a 2D alignment tool. Systematic and random deviations of the treatment setup were calculated for each individual patient. The statistical confidence on the convergence of both systematic and random deviations with time were tested to determine the number of initial daily portal images needed to predict these deviations. In addition, a mean deviation for each site was also calculated using the setup errors from all patients. Two treatment planning schemes were simulated to evaluate margin design and prescription dose adjustment. Therapeutic scores were quantified in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP). In the first

Learning Convex Inference of Marginals

OpenAIRE

Domke, Justin

2012-01-01

Graphical models trained using maximum likelihood are a common tool for probabilistic inference of marginal distributions. However, this approach suffers difficulties when either the inference process or the model is approximate. In this paper, the inference process is first defined to be the minimization of a convex function, inspired by free energy approximations. Learning is then done directly in terms of the performance of the inference process at univariate marginal prediction. The main ...

Determination of acrylamide levels in potato crisps and other snacks and exposure risk assessment through a Margin of Exposure approach.

Science.gov (United States)

Esposito, Francesco; Nardone, Antonio; Fasano, Evelina; Triassi, Maria; Cirillo, Teresa

2017-10-01

Potato crisps, corn-based extruded snacks and other savoury snacks are very popular products especially among younger generations. These products could be a potential source of acrylamide (AA), a toxic compound which could develop during frying and baking processes. The purpose of this study was the assessment of the dietary intake to AA across six groups of consumers divided according to age through the consumption of potato crisps and other snacks, in order to eventually evaluate the margin of exposure (MOE) related to neurotoxic and carcinogenic critical endpoints. Different brands of potato crisps and other popular snacks were analyzed through a matrix solid-phase dispersion method followed by a bromination step and GC-MS quantification. The concentration of detected AA ranged from 21 to 3444 ng g - 1 and the highest level occurred in potato crisps samples which showed a median value of 968 ng g - 1 . The risk characterization through MOE assessment revealed that five out of six consumers groups showed higher exposure values associated with an augmented carcinogenic risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Life Cycle Assessment to Municipal Wastewater Treatment Plant

International Nuclear Information System (INIS)

Garcia, J. s.; Herrera, I.; Rodriguez, A.

2011-01-01

The evaluation was done at a Municipal Wastewater Treatment Plant (MWTP), through the application of the methodology of Life Cycle Assessment (LCA) performed by using a commercial tool called SIMAPRO. The objective of this study was to apply Life Cycle Assessment (LCA) in two systems: municipal wastewater effluent without treatment and Wastewater Treatment Plant (WTP) that is operating in poor condition and has a direct discharge to a natural body, which is a threat to the environment. A LCA was done using SIMAPRO 7, in order to determine the environmental impact in each scenery was assessed, a comparison of the impacts and propose improvements to decrease, following the steps this methodology and according to the respective standardized normative (ISO 14040/ ISO 14044). In this study, most of used data have been reported by the plant from early 2010 and some data from literature. We identified the environmental impacts generated by the treatment, making emphasis on those related to the subsequent use of the water body receiving the discharge, such as eutrophication (near to 15% reduction). Likewise, a comparative analysis between the impacts in the two systems, with and without treatment by analyzing the variation in the impact categories studied. Finally within this work, alternatives of improvements, in order to reduce the identified and quantified impacts are proposed. (Author) 33 refs.

Marginal adaptation and CAD-CAM technology: A systematic review of restorative material and fabrication techniques.

Science.gov (United States)

Papadiochou, Sofia; Pissiotis, Argirios L

2018-04-01

The comparative assessment of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and other fabrication techniques pertaining to marginal adaptation should be documented. Limited evidence exists on the effect of restorative material on the performance of a CAD-CAM system relative to marginal adaptation. The purpose of this systematic review was to investigate whether the marginal adaptation of CAD-CAM single crowns, fixed dental prostheses, and implant-retained fixed dental prostheses or their infrastructures differs from that obtained by other fabrication techniques using a similar restorative material and whether it depends on the type of restorative material. An electronic search of English-language literature published between January 1, 2000, and June 30, 2016, was conducted of the Medline/PubMed database. Of the 55 included comparative studies, 28 compared CAD-CAM technology with conventional fabrication techniques, 12 contrasted CAD-CAM technology and copy milling, 4 compared CAD-CAM milling with direct metal laser sintering (DMLS), and 22 investigated the performance of a CAD-CAM system regarding marginal adaptation in restorations/infrastructures produced with different restorative materials. Most of the CAD-CAM restorations/infrastructures were within the clinically acceptable marginal discrepancy (MD) range. The performance of a CAD-CAM system relative to marginal adaptation is influenced by the restorative material. Compared with CAD-CAM, most of the heat-pressed lithium disilicate crowns displayed equal or smaller MD values. Slip-casting crowns exhibited similar or better marginal accuracy than those fabricated with CAD-CAM. Cobalt-chromium and titanium implant infrastructures produced using a CAD-CAM system elicited smaller MD values than zirconia. The majority of cobalt-chromium restorations/infrastructures produced by DMLS displayed better marginal accuracy than those fabricated with the casting technique. Compared with copy

Spectrum estimation method based on marginal spectrum

International Nuclear Information System (INIS)

Cai Jianhua; Hu Weiwen; Wang Xianchun

2011-01-01

FFT method can not meet the basic requirements of power spectrum for non-stationary signal and short signal. A new spectrum estimation method based on marginal spectrum from Hilbert-Huang transform (HHT) was proposed. The procession of obtaining marginal spectrum in HHT method was given and the linear property of marginal spectrum was demonstrated. Compared with the FFT method, the physical meaning and the frequency resolution of marginal spectrum were further analyzed. Then the Hilbert spectrum estimation algorithm was discussed in detail, and the simulation results were given at last. The theory and simulation shows that under the condition of short data signal and non-stationary signal, the frequency resolution and estimation precision of HHT method is better than that of FFT method. (authors)

Treatment accuracy of fractionated stereotactic radiotherapy

International Nuclear Information System (INIS)

Kumar, Shaleen; Burke, Kevin; Nalder, Colin; Jarrett, Paula; Mubata, Cephas; A'Hern, Roger; Humphreys, Mandy; Bidmead, Margaret; Brada, Michael

2005-01-01

Background and purpose: To assess the geometric accuracy of the delivery of fractionated stereotactic radiotherapy (FSRT) for brain tumours using the Gill-Thomas-Cosman (GTC) relocatable frame. Accuracy of treatment delivery was measured via portal images acquired with an amorphous silicon based electronic portal imager (EPI). Results were used to assess the existing verification process and to review the current margins used for the expansion of clinical target volume (CTV) to planning target volume (PTV). Patients and methods: Patients were immobilized in a GTC frame. Target volume definition was performed on localization CT and MRI scans and a CTV to PTV margin of 5 mm (based on initial experience) was introduced in 3D. A Brown-Roberts-Wells (BRW) fiducial system was used for stereotactic coordinate definition. The existing verification process consisted of an intercomparison of the coordinates of the isocentres and anatomy between the localization and verification CT scans. Treatment was delivered with 6 MV photons using four fixed non-coplanar conformal fields using a multi-leaf collimator. Portal imaging verification consisted of the acquisition of orthogonal images centred through the treatment isocentre. Digitally reconstructed radiographs (DRRs) created from the CT localization scans were used as reference images. Semi-automated matching software was used to quantify set up deviations (displacements and rotations) between reference and portal images. Results: One hundred and twenty six anterior and 123 lateral portal images were available for analysis for set up deviations. For displacements, the total errors in the cranial/caudal direction were shown to have the largest SD's of 1.2 mm, while systematic and random errors reached SD's of 1.0 and 0.7 mm, respectively, in the cranial/caudal direction. The corresponding data for rotational errors (the largest deviation was found in the sagittal plane) was 0.7 deg. SD (total error), 0.5 deg. (systematic) and 0

Verification of the patient positioning for evaluation of PTV margins in radiotherapy of prostate cancer

International Nuclear Information System (INIS)

Frohlich, B.F.; Peron, T.M.; Scheid, A.M.; Cardoso, F.; Alves, F.; Alves, M.S.; Dias, T.M.

2016-01-01

The work aimed to verify the relative displacements between the patient and the isocenters of the device based on the reproducibility of positioning, and estimates a PTV margins of radiotherapy treatments for prostate cancer. The results of displacements were obtained from a sample of 30 patient and showed values in vertical, longitudinal and lateral directions -0.03 ± 0.48 cm, 0.12 ± 0.47 cm and 0.02 ± 0.53 cm, respectively. PTV margins were calculated resulting in 0.97 cm for vertical direction, 0.85 cm for longitudinal, and 0.98 cm for lateral. (author)

Potential for Conservation Agriculture in the Dry Marginal Zone of Central Syria: A Preliminary Assessment

Directory of Open Access Journals (Sweden)

Baqir Lalani

2018-02-01

Full Text Available This paper reports on early soil related outcomes from conservation agriculture (CA benchmark sites located within the marginal rainfed environment of agro-ecological zone 4 (annual rainfall: 200–250 mm in pre-conflict central Syria. The outcomes reported are specifically those that relate to beneficial soil quality and water retention attributes relative to conventional tillage-based soil management practices applied to the fodder barley–livestock system, the dominant system in the zone. On-farm operational research was established to examine the impact of a barley (Hordeum vulgare and vetch (Vicia sativa rotation intercropped with atriplex (Atriplex halimus and salsola (Salsola collina, under CA and conventional tillage agriculture, on the soil quality parameters and crop productivity. Preliminary results showed that CA had a positive effect on the soil quality parameters and crop performance. The soil moisture and hydraulic conductivity were higher under CA (p < 0.05, combined with improved productivity (grain and above-ground biomass under specific crop mixes. The results suggest that despite the marginal nature of the zone, the use of CA is a viable option for the future of farmers’ livelihoods within similar localities and agro-climates, given the benefits for soil moisture and grain and straw productivity. In addition, it is likely to positively impact those in marginal environments where both pastoralism and agro-pastoralism production systems co-exist and compete for crop biomass as a main source of livestock feed. The increase in grain and straw yields vis-à-vis improvements in biophysical parameters in the CA system relative to tillage agriculture does suggest, however, that the competition with livestock for biomass is likely to reduce over time, and farmers would be able to return increased levels of straw (as stubble and residue as mulch, given improved biomass yields.

The Westgate Service and Related Referral, Assessment, and Treatment Processes.

Science.gov (United States)

Bennett, Alice L

2015-12-01

The formerly named "Dangerous and Severe Personality Disorder" (DSPD) units are no longer standalone services within the criminal justice system in England and Wales. These sites now provide personality disorder treatment services in the high-security prison estate as part of the new national Offender Personality Disorder (OPD) Pathway Strategy. The OPD Pathway intends to take responsibility for the assessment, treatment, and management of offenders who are likely to have a personality disorder and who present a high risk of re-offending (men and women) and serious harm to others (men). Further PD treatment and progression services are being commissioned in lower security prisons and in the community as part of the new PD Strategy. While the suitability criteria for the two male high-security PD treatment sites are the same, the individual units have their own assessment and treatment methods. This article aims to communicate the referral, assessment, and treatment methods employed within the prison-based Westgate Personality Disorder Treatment Service, HMP Frankland. © The Author(s) 2014.

SU-F-J-102: Lower Esophagus Margin Implications Based On Rapid Computational Algorithm for SBRT

Energy Technology Data Exchange (ETDEWEB)

Cardenas, M; Mazur, T; Li, H; Mutic, S; Bradley, J; Tsien, C; Green, O [Washington University School of Medicine, Saint Louis, MO (United States)

2016-06-15

Purpose: To quantify inter-fraction esophagus-variation. Methods: Computed tomography and daily on-treatment 0.3-T MRI data sets for 7 patients were analyzed using a novel Matlab-based (Mathworks, Natick, MA) rapid computational method. Rigid registration was performed from the cricoid to the gastro-esophageal junction. CT and MR-based contours were compared at slice intervals of 3mm. Variation was quantified by “expansion,” defined as additional length in any radial direction from CT contour to MR contour. Expansion computations were performed with 360° of freedom in each axial slice. We partitioned expansions into left anterior, right anterior, right posterior, and left posterior quadrants (LA, RA, RP, and LP, respectively). Sample means were compared by analysis of variance (ANOVA) and Fisher’s Protected Least Significant Difference test. Results: Fifteen fractions and 1121 axial slices from 7 patients undergoing SBRT for primary lung cancer (3) and metastatic lung disease (4) were analyzed, generating 41,970 measurements. Mean LA, RA, RP, and LP expansions were 4.30±0.05 mm, 3.71±0.05mm, 3.17±0.07, and 3.98±0.06mm, respectively. 50.13% of all axial slices showed variation > 5 mm in one or more directions. Variation was greatest in lower esophagus with mean LA, RA, RP, and LP expansion (5.98±0.09 mm, 4.59±0.09 mm, 4.04±0.16 mm, and 5.41±0.16 mm, respectively). The difference was significant compared to mid and upper esophagus (p<.0001). The 95th percentiles of expansion for LA, RA, RP, LP were 13.36 mm, 9.97 mm, 11.29 mm, and 12.19 mm, respectively. Conclusion: Analysis of on-treatment MR imaging of the lower esophagus during thoracic SBRT suggests margin expansions of 13.36 mm LA, 9.97 mm RA, 11.29 mm RP, 12.19 mm LP would account for 95% of measurements. Our novel algorithm for rapid assessment of margin expansion for critical structures with 360° of freedom in each axial slice enables continuously adaptive patient-specific margins which may

Marginal ridge fracture resistance, microleakage and pulpal response to glass ionomer/glass cermet partial tunnel restorations.

Science.gov (United States)

Prabhu, N T; Munshi, A K; Shetty, T R

1997-01-01

Sixty sound premolars which were to be extracted for orthodontic treatment purposes were restored either with glass ionomer cement or glass cermet cements after partial tunnel preparation, and prior to the extraction after a time interval of 30 and 60 days respectively. The teeth were then subjected to marginal ridge fracture resistance, microleakage study using dye penetration and histological evaluation of the pulpal response to these materials. Both the materials exhibited increase in marginal ridge fracture resistance at 60 days, with minimal degree of microleakage and were biologically compatible with the dental pulp.

Study on structural seismic margin and probabilistic seismic risk. Development of a structural capacity-seismic risk diagram

International Nuclear Information System (INIS)

Nakajima, Masato; Ohtori, Yasuki; Hirata, Kazuta

2010-01-01

Seismic margin is extremely important index and information when we evaluate and account seismic safety of critical structures, systems and components quantitatively. Therefore, it is required that electric power companies evaluate the seismic margin of each plant in back-check of nuclear power plants in Japan. The seismic margin of structures is usually defined as a structural capacity margin corresponding to design earthquake ground motion. However, there is little agreement as to the definition of the seismic margin and we have no knowledge about a relationship between the seismic margin and seismic risk (annual failure probability) which is obtained in PSA (Probabilistic Safety Assessment). The purpose of this report is to discuss a definition of structural seismic margin and to develop a diagram which can identify a relation between seismic margin and seismic risk. The main results of this paper are described as follows: (1) We develop seismic margin which is defined based on the fact that intensity of earthquake ground motion is more appropriate than the conventional definition (i.e., the response-based seismic margin) for the following reasons: -seismic margin based on earthquake ground motion is invariant where different typed structures are considered, -stakeholders can understand the seismic margin based on the earthquake ground motion better than the response-based one. (2) The developed seismic margin-risk diagram facilitates us to judge easily whether we need to perform detailed probabilistic risk analysis or only deterministic analysis, given that the reference risk level although information on the uncertainty parameter beta is not obtained. (3) We have performed numerical simulations based on the developed method for four sites in Japan. The structural capacity-risk diagram differs depending on each location because the diagram is greatly influenced by seismic hazard information for a target site. Furthermore, the required structural capacity

Thermal margin model for transition core of KSNP

International Nuclear Information System (INIS)

Nahm, Kee Yil; Lim, Jong Seon; Park, Sung Kew; Chun, Chong Kuk; Hwang, Sun Tack

2004-01-01

The PLUS7 fuel was developed with mixing vane grids for KSNP. For the transition core partly loaded with the PLUS7 fuels, the procedure to set up the optimum thermal margin model of the transition core was suggested by introducing AOPM concept into the screening method which determines the limiting assembly. According to the procedure, the optimum thermal margin model of the first transition core was set up by using a part of nuclear data for the first transition and the homogeneous core with PLUS7 fuels. The generic thermal margin model of PLUS7 fuel was generated with the AOPM of 138%. The overpower penalties on the first transition core were calculated to be 1.0 and 0.98 on the limiting assembly and the generic thermal margin model, respectively. It is not usual case to impose the overpower penalty on reload cores. It is considered that the lack of channel flow due to the difference of pressure drop between PLUS7 and STD fuels results in the decrease of DNBR. The AOPM of the first transition core is evaluated to be about 135% by using the optimum generic thermal margin model which involves the generic thermal margin model and the total overpower penalty. The STD fuel is not included among limiting assembly candidates in the second transition core, because they have much lower pin power than PLUS7 fuels. The reduced number of STD fuels near the limiting assembly candidates the flow from the limiting assembly to increase the thermal margin for the second transition core. It is expected that cycle specific overpower penalties increase the thermal margin for the transition core. Using the procedure to set up the optimum thermal margin model makes sure that the enhanced thermal margin of PLUS7 fuel can be sufficiently applied to not only the homogeneous core but also the transition core

Reconstructing Rodinia by Fitting Neoproterozoic Continental Margins

Science.gov (United States)

Stewart, John H.

2009-01-01

Reconstructions of Phanerozoic tectonic plates can be closely constrained by lithologic correlations across conjugate margins by paleontologic information, by correlation of orogenic belts, by paleomagnetic location of continents, and by ocean floor magmatic stripes. In contrast, Proterozoic reconstructions are hindered by the lack of some of these tools or the lack of their precision. To overcome some of these difficulties, this report focuses on a different method of reconstruction, namely the use of the shape of continents to assemble the supercontinent of Rodinia, much like a jigsaw puzzle. Compared to the vast amount of information available for Phanerozoic systems, such a limited approach for Proterozoic rocks, may seem suspect. However, using the assembly of the southern continents (South America, Africa, India, Arabia, Antarctica, and Australia) as an example, a very tight fit of the continents is apparent and illustrates the power of the jigsaw puzzle method. This report focuses on Neoproterozoic rocks, which are shown on two new detailed geologic maps that constitute the backbone of the study. The report also describes the Neoproterozoic, but younger or older rocks are not discussed or not discussed in detail. The Neoproterozoic continents and continental margins are identified based on the distribution of continental-margin sedimentary and magmatic rocks that define the break-up margins of Rodinia. These Neoproterozoic continental exposures, as well as critical Neo- and Meso-Neoproterozoic tectonic features shown on the two new map compilations, are used to reconstruct the Mesoproterozoic supercontinent of Rodinia. This approach differs from the common approach of using fold belts to define structural features deemed important in the Rodinian reconstruction. Fold belts are difficult to date, and many are significantly younger than the time frame considered here (1,200 to 850 Ma). Identifying Neoproterozoic continental margins, which are primarily

Can low-fusing glass application affect the marginal misfit and bond strength of Y-TZP crowns?

Science.gov (United States)

Antunes, Monize Carelli Felipe; Miranda, Jean Soares; Carvalho, Ronaldo Luís Almeida de; Carvalho, Rodrigo Furtado de; Kimpara, Estevão Tomomitsu; Assunção E Souza, Rodrigo Othávio de; Leite, Fabíola Pessôa Pereira

2018-01-01

To evaluate the effect of different surface treatments on the marginal misfit and retentive strength between Y-TZP crowns and an epoxy resin. Forty (40) epoxy resin (G10) abutments (height: 5mm, conicity: 60, finish line: large chamfer) with equal dimensions were milled and included in polyurethane to simulate the periodontal ligament. Next, 40 Y-TZP crowns (thickness: 1mm) were milled (Cerec in Lab) and randomly divided into four groups (n=10) according to the surface treatment: GS(glaze spray), GP(glaze powder/liquid), P(zirconia primer) and RS(tribochemical silica coating). The conditioned surfaces were cemented with dual self-adhesive cement, light cured and submitted to thermomechanical cycling (2x106, 100N, 4Hz, 5°/55°C). Marginal misfit was analyzed by a stereomicroscope and SEM. Retentive strength test was performed (1mm/min) until crown debonding. Glaze layer thickness was also performed to GS and GP groups. Marginal misfit data were analyzed by Kruskal Wallis and Dunn tests; one-way ANOVA and Tukey (5%) analyzed the tensile strength data. The marginal misfit of the GS (48.6±19.9μm) and GP (65.4±42.5μm) were statistically lower than the RS (96±62.9μm) and P (156±113.3μm) (p=0.001). The retentive strength of the GP (470.5±104.1N) and GS (416.8±170.2N) were similar to the P (342.1±109.7N), but statistically higher than those of the RS (208.9±110N). The GS and GP glaze layer was 11.64μm and 9.73μm respectively. Thus, glaze application promoted lower marginal discrepancy and higher retentive strength values than conventional techniques.

Assessment, management and treatment of acute fingertip injuries.

Science.gov (United States)

Kearney, Anthony; Canty, Louise

2016-06-01

Fingertip injuries with nail bed trauma can require specialist hand surgery, depending on severity. However, most of these injuries can be managed in well-equipped emergency departments by emergency nurses with an in-depth knowledge and understanding of the anatomy and physiology of the fingernail and surrounding structures, assessment and examination, pain management and treatment. This article describes the surface and underlying anatomy and physiology of the nail, the most common mechanisms of injury, relevant diagnostic investigations, and initial assessment and management. It also discusses treatment options, referral pathways, and patient discharge advice.

Clinical outcomes assessment in clinical trials to assess treatment of femoroacetabular impingement

DEFF Research Database (Denmark)

Harris-Hayes, Marcie; McDonough, Christine M; Leunig, Michael

2013-01-01

Patient-reported outcome measures are an important component of outcomes assessment in clinical trials to assess the treatment of femoroacetabular impingement (FAI). This review of disease-specific measures and instruments used to assess the generic quality of life and physical activity levels...... developed recently and have not been established in the literature. Although currently used generic and activity-level measures have limitations, as well, they should be considered, depending on the specific goals of the study. Additional research is needed to assess the properties of these measures fully...

Specific phobias in youth: a randomized controlled trial comparing one-session treatment to a parent-augmented one-session treatment.

Science.gov (United States)

Ollendick, Thomas H; Halldorsdottir, Thorhildur; Fraire, Maria G; Austin, Kristin E; Noguchi, Ryoichi J P; Lewis, Krystal M; Jarrett, Matthew A; Cunningham, Natoshia R; Canavera, Kristin; Allen, Kristy B; Whitmore, Maria J

2015-03-01

Examine the efficacy of a parent-augmented One-Session Treatment (A-OST) in treating specific phobias (SP) in youth by comparing this novel treatment to child-focused OST, a well-established treatment. A total of 97 youth (ages 6-15, 51.5% female, 84.5% White) who fulfilled diagnostic criteria for SP were randomized to either A-OST or OST. SPs were assessed with semistructured diagnostic interviews, clinician improvement ratings, and parent and child improvement ratings. In addition, measures of treatment satisfaction and parental self-efficacy were obtained. Blind assessments were completed pretreatment, posttreatment, and 1month and 6months following treatment. Analyses were undertaken using mixed models. In addition, gender, age, internalizing/externalizing problems, parent overprotection, and parent anxiety were examined as potential predictors and moderators of treatment outcome. Both treatment conditions produced similar outcomes with approximately 50% of youth in both treatments diagnosis free and judged to be much or very much improved at posttreatment and 1-month follow-up. At 6-month follow-up, however, the treatments diverged with OST resulting in marginally superior outcomes to A-OST, contrary to predictions. Only age of child predicted treatment outcome across the two treatments (older children did better); unexpectedly, none of the variables moderated treatment outcomes. Parent augmentation of OST produced no appreciable gains in treatment outcomes. Directions for future research are highlighted. Copyright © 2014. Published by Elsevier Ltd.

Value of standard personality assessments in informing clinical decision - making in a medium secure unit.

Science.gov (United States)

Duggan, Conor; Mason, Lauren; Banerjee, Penny; Milton, John

2007-05-01

Assessing those with personality disorder for treatment in secure settings is known to be unsatisfactory. To examine the utility of a standardised assessment of offenders with personality disorder referred for treatment in secure care in a naturalistic study. A consecutive series of 89 men were assessed with a battery of four recommended instruments measuring personality and risk. Decisions on whether or not to admit were based on a multidisciplinary discussion informed by these assessments. Of the 89 comprehensively assessed referrals, 60 (67%) were offered admission. High scores on the Psychopathy Checklist-Revised (especially on Factor 1) was the only measure that was associated with rejection. Of 44 patients discharged, 29 (66%) failed to complete treatment; none of the pre-admission assessments distinguished ;completers' from ;non-completers'. Although skills were acquired on the unit, follow-up of 24 men in the community showed that this had only a marginal effect on re-offending rate (58%). Current recommended assessment methods appear unsatisfactory in identifying those who either (a) complete treatment or (b) benefit from treatment. Our results throw doubt on their value.

Margins in breast conserving surgery: The financial cost & potential savings associated with the new margin guidelines.

Science.gov (United States)

Singer, Lauren; Brown, Eric; Lanni, Thomas

2016-08-01

In this study, we compare the indications for re-excision, the findings of additional tumor in the re-excision specimen as they relate to margin status, and costs associated with re-excision based on recent new consensus statements. A retrospective analysis was performed on 462 patients with invasive breast carcinoma who underwent at least one lumpectomy between January 2011 and December 2013. Postoperative data was analyzed based on where additional disease was found, as it relates to the margin status of the initial lumpectomy and the additional direct costs associated with additional procedures. Of the 462 patients sampled, 149 underwent a re-excision surgery (32.2%). Four patients underwent mastectomy as their second operation. In the 40 patients with additional disease found on re-excision, 36 (90.0%) of them had a positive margin on their initial lumpectomy. None of the four mastectomy patients had residual disease. The mean cost of the initial lumpectomy for all 462 patients was $2118.01 plus an additional $1801.92 for those who underwent re-excision. A positive margin was most predictive of finding residual tumor on re-excision as would be expected. Using old criteria only 0.07% (4/61) of patients who had undergone re-excision with a 'clear' margin, had additional tumor found, at a total cost of $106,354.11. Thus, the new consensus guidelines will lead to less overall cost, at no clinical risk to patients while reducing a patient's surgical risk and essentially eliminating delays in adjuvant care. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of prostate set-up accuracy and margins with off-line bony anatomy corrections and online implanted fiducial-based corrections.

Science.gov (United States)

Greer, P B; Dahl, K; Ebert, M A; Wratten, C; White, M; Denham, J W

2008-10-01

The aim of the study was to determine prostate set-up accuracy and set-up margins with off-line bony anatomy-based imaging protocols, compared with online implanted fiducial marker-based imaging with daily corrections. Eleven patients were treated with implanted prostate fiducial markers and online set-up corrections. Pretreatment orthogonal electronic portal images were acquired to determine couch shifts and verification images were acquired during treatment to measure residual set-up error. The prostate set-up errors that would result from skin marker set-up, off-line bony anatomy-based protocols and online fiducial marker-based corrections were determined. Set-up margins were calculated for each set-up technique using the percentage of encompassed isocentres and a margin recipe. The prostate systematic set-up errors in the medial-lateral, superior-inferior and anterior-posterior directions for skin marker set-up were 2.2, 3.6 and 4.5 mm (1 standard deviation). For our bony anatomy-based off-line protocol the prostate systematic set-up errors were 1.6, 2.5 and 4.4 mm. For the online fiducial based set-up the results were 0.5, 1.4 and 1.4 mm. A prostate systematic error of 10.2 mm was uncorrected by the off-line bone protocol in one patient. Set-up margins calculated to encompass 98% of prostate set-up shifts were 11-14 mm with bone off-line set-up and 4-7 mm with online fiducial markers. Margins from the van Herk margin recipe were generally 1-2 mm smaller. Bony anatomy-based set-up protocols improve the group prostate set-up error compared with skin marks; however, large prostate systematic errors can remain undetected or systematic errors increased for individual patients. The margin required for set-up errors was found to be 10-15 mm unless implanted fiducial markers are available for treatment guidance.

Treatment Outcomes of Locally Advanced Squamous Cell Carcinoma of the Ethmoid Sinus Treated with Anterior Craniofacial Resection or Chemoradiotherapy

Directory of Open Access Journals (Sweden)

Takeharu Ono

2017-04-01

Full Text Available We retrospectively analyzed 14 patients with locally advanced squamous cell carcinoma of ethmoid sinus (LASCC-ES for the feasibility of anterior craniofacial resection (ACFR. Ethmoid cancer treatment comprised alternating chemoradiotherapy (ALCRT; n = 1, concomitant radiotherapy and intra-arterial cisplatin (RADPLAT; n = 4 and ACFR (n = 9. The 3- and 5-year overall survival (OS rates of patients were 47.6 and 39.6%, respectively. The 3-year local control (LC rates of chemoradiotherapy (CRT; ALCRT and RADPLAT (n = 5 and ACFR (n = 9 groups were 0 and 66.7% (p = 0.012, respectively. The 3-year progression-free survival (PFS rate of the CRT and ACFR groups were 0 and 55.6% (p = 0.018, respectively. The 3-year OS rate of the CRT and ACFR groups were 0 and 76.2% (p = 0.005, respectively. Postoperative pathological examinations confirmed positive margins in 3 (33% of 9 cases. The 3-year LC and PFS rates of cases (n = 3 with positive surgical margins were significantly poorer than those of cases (n = 6 with negative surgical margins. Although ACFR for LASCC-ES is a feasible treatment, cases with positive surgical margins were more prone to local relapse. Therefore, surgical safety margins should be thoroughly assessed.

Plasticity margin recovery during annealing after cold deformation

International Nuclear Information System (INIS)

Bogatov, A.A.; Smirnov, S.V.; Kolmogorov, V.L.

1978-01-01

Restoration of the plasticity margin in steel 20 after cold deformation and annealing at 550 - 750 C and soaking for 5 - 300 min was investigated. The conditions of cold deformation under which the metal acquires microdefects unhealed by subsequent annealing were determined. It was established that if the degree of utilization of the plasticity margin is psi < 0.5, the plasticity margin in steel 20 can be completely restored by annealing. A mathematical model of restoration of the plasticity margin by annealing after cold deformation was constructed. A statistical analysis showed good agreement between model and experiment

Outcomes and Patterns of Failure for Grade 2 Meningioma Treated With Reduced-Margin Intensity Modulated Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Press, Robert H. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Prabhu, Roshan S., E-mail: roshansprabhu@gmail.com [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Appin, Christina L.; Brat, Daniel J. [Department of Pathology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Shu, Hui-Kuo G. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Hadjipanayis, Constantinos; Olson, Jeffrey J.; Oyesiku, Nelson M. [Department of Neurosurgery, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Curran, Walter J.; Crocker, Ian [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)

2014-04-01

Purpose: The purpose of this study was to evaluate intracranial control and patterns of local recurrence (LR) for grade 2 meningiomas treated with intensity modulated radiation therapy (IMRT) with limited total margin expansions of ≤1 cm. Methods and Materials: We reviewed records of patients with a neuropathological diagnosis of grade 2 meningioma who underwent IMRT at our institution between 2002 and 2012. Actuarial rates were determined by the Kaplan-Meier method from the end of RT. LR was defined as in-field if ≥90% of the recurrence was within the prescription isodose, out-of-field (marginal) if ≥90% was outside of the prescription isodose, and both if neither criterion was met. Results: Between 2002 and 2012, a total of 54 consecutive patients underwent IMRT for grade 2 meningioma. Eight of these patients had total initial margins >1 cm and were excluded, leaving 46 patients for analysis. The median imaging follow-up period was 26.2 months (range, 7-107 months). The median dose for fractionated IMRT was 59.4 Gy (range, 49.2-61.2 Gy). Median clinical target volume (CTV), planning target volume (PTV), and total margin expansion were 0.5 cm, 0.3 cm, and 0.8 cm, respectively. LR occurred in 8 patients (17%), with 2-year and 3-year actuarial local control (LC) of 92% and 74%, respectively. Six of 8 patients (85%) had a known pattern of failure. Five patients (83%) had in-field LR; no patients had marginal LR; and 1 patient (17%) had both. Conclusions: The use of IMRT to treat grade 2 meningiomas with total initial margins (CTV + PTV) ≤1 cm did not appear to compromise outcomes or increase marginal failures compared with other modern retrospective series. Of the 46 patients who had margins ≤1 cm, none experienced marginal failure only. These results demonstrate efficacy and low risk of marginal failure after IMRT treatment of grade 2 meningiomas with reduced margins, warranting study within a prospective clinical trial.

Reporting methods of blinding in randomized trials assessing nonpharmacological treatments.

Directory of Open Access Journals (Sweden)

Isabelle Boutron

2007-02-01

Full Text Available BACKGROUND: Blinding is a cornerstone of treatment evaluation. Blinding is more difficult to obtain in trials assessing nonpharmacological treatment and frequently relies on "creative" (nonstandard methods. The purpose of this study was to systematically describe the strategies used to obtain blinding in a sample of randomized controlled trials of nonpharmacological treatment. METHODS AND FINDINGS: We systematically searched in Medline and the Cochrane Methodology Register for randomized controlled trials (RCTs assessing nonpharmacological treatment with blinding, published during 2004 in high-impact-factor journals. Data were extracted using a standardized extraction form. We identified 145 articles, with the method of blinding described in 123 of the reports. Methods of blinding of participants and/or health care providers and/or other caregivers concerned mainly use of sham procedures such as simulation of surgical procedures, similar attention-control interventions, or a placebo with a different mode of administration for rehabilitation or psychotherapy. Trials assessing devices reported various placebo interventions such as use of sham prosthesis, identical apparatus (e.g., identical but inactivated machine or use of activated machine with a barrier to block the treatment, or simulation of using a device. Blinding participants to the study hypothesis was also an important method of blinding. The methods reported for blinding outcome assessors relied mainly on centralized assessment of paraclinical examinations, clinical examinations (i.e., use of video, audiotape, photography, or adjudications of clinical events. CONCLUSIONS: This study classifies blinding methods and provides a detailed description of methods that could overcome some barriers of blinding in clinical trials assessing nonpharmacological treatment, and provides information for readers assessing the quality of results of such trials.

Internal Distraction Osteogenesis With Piezosurgery Oblique Osteotomy of Supraorbital Margin of Frontal Bone for the Treatment of Unilateral Coronal Synostosis.

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Shen, Weimin; Cui, Jie; Chen, Jianbing; Ji, Yi; Kong, Liangliang

2017-05-01

To assess the utility of internal distraction osteogenesis with Piezosurgery oblique osteotomy of supraorbital margin of frontal bone for the treatment of unilateral coronal synostosis and to study the outcome and complications of this procedure. Oblique osteotomy allows for entry into the cranial cavity, and along with parallel cut to the roof of the orbit, avoids the need to cut into the orbit which forms the frontal flap. Oblique osteotomy was performed along the supraorbital rim to do a frontal suture of the glabella (ages of patients were less than 1 year) or on the opposite side of the supraorbital rim (ages of patients were older than 1 year) after performing a suturectomy of the effected coronal suture. Two internal distraction devices were subsequently placed across the osteotomized, fused coronal suture. Finally, the cranium pieces were divided in the middle and placed in the middle of the frontal bone using biological glue. Five days after the operation, a 0.6-mm distraction was done twice daily. The distraction was removed 6 months after reaching 2 to 3 cm. Internal distraction osteogenesis with supraorbital oblique osteotomy was performed in 9 patients suffering from unilateral coronal synostosis. Eight patients had no postoperative infections around the shaft puncture wounds. One patient had infection in the rods around the distraction during the period of fixed, but was cured with antibiotic treatment. During a mean follow-up period of 12 months (5-26 months), all patients were satisfied with the cosmetic and functional results. No complications, including fixed screw displacement, penetration of the cranium and dura mater or retraction of distraction devices, occurred. The devices were exposed in 1 patient, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients. Use of this procedure avoids the need for frontal osteotomy to move the orbit forward. Adding 2 cranium strips can be used to

Reinforcing marginality? Maternal health interventions in rural Nicaragua.

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Kvernflaten, Birgit

2017-06-23

To achieve Millennium Development Goal 5 on maternal health, many countries have focused on marginalized women who lack access to care. Promoting facility-based deliveries to ensure skilled birth attendance and emergency obstetric care has become a main measure for preventing maternal deaths, so women who opt for home births are often considered 'marginal' and in need of targeted intervention. Drawing upon ethnographic data from Nicaragua, this paper critically examines the concept of marginality in the context of official efforts to increase institutional delivery amongst the rural poor, and discusses lack of access to health services among women living in peripheral areas as a process of marginalization. The promotion of facility birth as the new norm, in turn, generates a process of 're-marginalization', whereby public health officials morally disapprove of women who give birth at home, viewing them as non-compliers and a problem to the system. In rural Nicaragua, there is a discrepancy between the public health norm and women's own preferences and desires for home birth. These women live at the margins also in spatial and societal terms, and must relate to a health system they find incapable of providing good, appropriate care. Strong public pressure for institutional delivery makes them feel distressed and pressured. Paradoxically then, the aim of including marginal groups in maternal health programmes engenders resistance to facility birth.

Prediction of Marginal Mass Required for Successful Islet Transplantation

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Papas, Klearchos K.; Colton, Clark K.; Qipo, Andi; Wu, Haiyan; Nelson, Rebecca A.; Hering, Bernhard J.; Weir, Gordon C.; Koulmanda, Maria

2013-01-01

Islet quality assessment methods for predicting diabetes reversal (DR) following transplantation are needed. We investigated two islet parameters, oxygen consumption rate (OCR) and OCR per DNA content, to predict transplantation outcome and explored the impact of islet quality on marginal islet mass for DR. Outcomes in immunosuppressed diabetic mice were evaluated by transplanting mixtures of healthy and purposely damaged rat islets for systematic variation of OCR/DNA over a wide range. The probability of DR increased with increasing transplanted OCR and OCR/DNA. On coordinates of OCR versus OCR/DNA, data fell into regions in which DR occurred in all, some, or none of the animals with a sharp threshold of around 150-nmol/min mg DNA. A model incorporating both parameters predicted transplantation outcome with sensitivity and specificity of 93% and 94%, respectively. Marginal mass was not constant, depended on OCR/DNA, and increased from 2,800 to over 100,000 islet equivalents/kg body weight as OCR/DNA decreased. We conclude that measurements of OCR and OCR/DNA are useful for predicting transplantation outcome in this model system, and OCR/DNA can be used to estimate the marginal mass required for reversing diabetes. Because human clinical islet preparations in a previous study had OCR/DNA values in the range of 100–150-nmol/min mg DNA, our findings suggest that substantial improvement in transplantation outcome may accompany increasedOCR/DNAin clinical islet preparations. PMID:20233002

THE MARGINAL FIT OF MILLED-CERAMIC INLAYS – A COMPARATIVE THREE DIMENSIONAL AND MICROSCOPIC RESEARCH

Directory of Open Access Journals (Sweden)

Sorana BACIU

2017-03-01

Full Text Available Objective: The main goal of the present study is to compare two methods for evaluating the marginal fit of fixed prosthetic restorations. For this purpose we used a milled ceramic material, out of which we obtained class I inlays. The marginal gap was analyzed using micro CT and electronic microscopy. Materials and methods: After extraction of four caries-free mandibular first molars, first class inlay cavities were prepared. The marginal gap was analyzed circumferentially at the occlusal margin using a Bruker micro CT, by measuring the distance at the occlusal limit of the cavities, between the restoration and the tooth in several points for every surface of each tooth before cementing. For the second method SEM technology was used, and measurements were made at the occlusal limit of the cavities, between the restoration and the tooth in 50 microns steps. The data were compared with One–way ANOVA with Tukey’s Multiple Comparison Test performed using 5.00 for Windows (GraphPad Prism 5.00 Software, San Diego, California USA. Results and discussion: For both methods we obtained clinical acceptable values of the marginal gap for the milled ceramic inlays. The null hypothesis was rejected. We obtained statistical significant differences of the measured gaps using the two above mentioned methods. Conclusions: Both evaluation methods are reliable for measuring the marginal gap of fixed prosthetic restorations, each method having specific indications, advantages and disadvantages. They offer indispensable information which lead to improvement of the restorative treatments.

Splenic marginal zone lymphoma: a review of the clinical presentation, pathology, molecular biology, and management

Directory of Open Access Journals (Sweden)

Teixeira Mendes LS

2014-07-01

Full Text Available Larissa Sena Teixeira Mendes,1 Ming-Qing Du,2 Estella Matutes,3 Andrew Wotherspoon11Histopathology Department, Royal Marsden Hospital, London, UK; 2Molecular Malignancy Laboratory and Department of Histopathology, University Hospital NHS Foundation Trust/Division of Molecular Histopathology, Department of Pathology, University of Cambridge, Cambridge, UK; 3Hematopathology Unit, Hospital Clinic, Barcelona University, Barcelona, Spain Abstract: Splenic marginal zone lymphoma is a distinct low grade B-cell lymphoma primarily occurring in the spleen and separate from nodal marginal zone lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. It is characterized by a relative indolent course, splenomegaly, moderate lymphocytosis, and an intrasinusoidal pattern of involvement, especially in the bone marrow. It is postulated that the neoplastic clone originates from persistent antigenic stimulation of marginal zone B-cells. Molecular and cytogenetic studies have failed to show specific alterations. There is no standard criterion to initiate treatment, which may include a watch and wait policy, splenectomy, or chemo/immunotherapy. This review highlights the main features of this entity, reassessing the guidelines for diagnosis, prognostic factors, staging, and management published by the SMZL Working Group (2008. Keywords: splenectomy, villous lymphocytes, guidelines

[Eyelid hygiene for contact lens wearers with blepharitis. Comparative investigation of treatment with baby shampoo versus phospholipid solution].

Science.gov (United States)

Khaireddin, R; Hueber, A

2013-02-01

Blepharitis due to Meibom gland dysfunction (MGD) is presumed to be one of the main reasons for dry eye symptoms which occur in up to 50% of contact lens users. Thus, MGD presumably plays an important role in dry eye in contact lens wearers. In the present prospective, randomized and double blind trial the efficacy of two established treatment options for MGD and blepharitis was evaluated in symptomatic contact lens wearers. In this prospective, randomized 2-centre trial 53 symptomatic contact lens wearers suffering from blepharitis were included. Patients were randomly selected for two treatment groups: group A performed lid margin hygiene using the commonly recommended mild baby shampoo (Bübchen Kinder Shampoo-extra augenmild, Bübchen Werk Ewald Hermes Pharmazeutische Fabrik GmbH, Soest, Germany) and group B performed lid margin hygiene using a phospholipid-liposome solution specially designed for lid hygiene (Blepha Cura, Optima, Moosburg/Wang, Germany), each for 4 weeks. Before as well as 4 weeks after initiation of this study the following tests were performed: standardized subjective assessment using the ocular surface disease index, non-invasive break-up time (NIBUT) and objective evaluation of lid-parallel conjunctival folds (LIPCOF) and further lid margin criteria by double blinded evaluation of slit lamp photographs. Of the 53 symptomatic contact lens wearers suffering from blepharitis 21 (39,6%) were randomly selected for treatment group A and 32 (60.4%) for group B. In both treatment groups there was objective and subjective improvement of symptoms of dry eye in contact lens wearers. Interestingly, there was a significantly greater improvement, subjective as well as objective, in treatment group B which used the phospholipidliposome solution for lid margin hygiene compared to group A using baby shampoo. Although both therapies improved symptoms of dry eye due to blepharitis in symptomatic contact lens wearers, patients using phospholipid

On recent developments in marginal separation theory.

Science.gov (United States)

Braun, S; Scheichl, S

2014-07-28

Thin aerofoils are prone to localized flow separation at their leading edge if subjected to moderate angles of attack α. Although 'laminar separation bubbles' at first do not significantly alter the aerofoil performance, they tend to 'burst' if α is increased further or if perturbations acting upon the flow reach a certain intensity. This then either leads to global flow separation (stall) or triggers the laminar-turbulent transition process within the boundary layer flow. This paper addresses the asymptotic analysis of the early stages of the latter phenomenon in the limit as the characteristic Reynolds number [Formula: see text], commonly referred to as marginal separation theory. A new approach based on the adjoint operator method is presented that enables the fundamental similarity laws of marginal separation theory to be derived and the analysis to be extended to higher order. Special emphasis is placed on the breakdown of the flow description, i.e. the formation of finite-time singularities (a manifestation of the bursting process), and on its resolution being based on asymptotic arguments. The passage to the subsequent triple-deck stage is described in detail, which is a prerequisite for carrying out a future numerical treatment of this stage in a proper way. Moreover, a composite asymptotic model is developed in order for the inherent ill-posedness of the Cauchy problems associated with the current flow description to be resolved.

Retail margins and the effects of an integrated Nordic end user market for electricity

Energy Technology Data Exchange (ETDEWEB)

Damsgaard, Niclas; Roempoetti, Marie

2007-09-15

impact of these effects on the customers' total price has not been assessed. Furthermore, it is possible that the customers can gain from receiving offers that are more adapted to their needs since a larger market provides better possibilities for market segmentation. The starting point for this project is an assumption that the customers can gain from a common Nordic market through reduced prices (or reduced margins). The question is thus: Can we expect that an integrated Nordic retail market for electricity will decrease the retail margins? In order to answer this question we study the existing retail margins and try to explain the differences in margins. We then analyse and assess whether an integrated Nordic market is likely to affect these margins. The main assumption is than that the reduced margins would come from an increased competitive pressure. In addition to reduced margins, there are several other possible benefits for the customers, e.g. improved competition and services, reduced costs, improvements in regulations and a better functioning wholesale market. This is discussed qualitatively in an adjacent report (Elforsk report 07:48). We find that it is not likely that an integrated Nordic retail market will increase the competitive pressure and in that way substantially reduce the retail margins. There might be some possibilities for reduced margins, at least in some countries and for some customer segments but the margins are generally relatively small. More importantly, the national retail markets are not very concentrated and a Nordic retail market will not dilute market power in the same way as is the case for the wholesale market. The price benefits for the customers can thus be expected to be modest. This conclusion does however not imply that our recommendation is not to pursue an integrated Nordic end-user market for electricity, but only that reduced retail margins probably is not a particularly strong argument for this

Colorado Basin Structure and Rifting, Argentine passive margin

Science.gov (United States)

Autin, Julia; Scheck-Wenderoth, Magdalena; Loegering, Markus; Anka, Zahie; Vallejo, Eduardo; Rodriguez, Jorge; Marchal, Denis; Reichert, Christian; di Primio, Rolando

2010-05-01

The Argentine margin presents a strong segmentation with considerable strike-slip movements along the fracture zones. We focus on the volcanic segment (between the Salado and Colorado transfer zones), which is characterized by seaward dipping reflectors (SDR) all along the ocean-continent transition [e.g. Franke et al., 2006; Gladczenko et al., 1997; Hinz et al., 1999]. The segment is structured by E-W trending basins, which differs from the South African margin basins and cannot be explained by classical models of rifting. Thus the study of the relationship between the basins and the Argentine margin itself will allow the understanding of their contemporary development. Moreover the comparison of the conjugate margins suggests a particular evolution of rifting and break-up. We firstly focus on the Colorado Basin, which is thought to be the conjugate of the well studied Orange Basin [Hirsch et al., 2009] at the South African margin [e.g. Franke et al., 2006]. This work presents results of a combined approach using seismic interpretation and structural, isostatic and thermal modelling highlighting the structure of the crust. The seismic interpretation shows two rift-related discordances: one intra syn-rift and the break-up unconformity. The overlying sediments of the sag phase are less deformed (no sedimentary wedges) and accumulated before the generation of oceanic crust. The axis of the Colorado Basin trends E-W in the western part, where the deepest pre-rift series are preserved. In contrast, the basin axis turns to a NW-SE direction in its eastern part, where mainly post-rift sediments accumulated. The most distal part reaches the margin slope and opens into the oceanic basin. The general basin direction is almost orthogonal to the present-day margin trend. The most frequent hypothesis explaining this geometry is that the Colorado Basin is an aborted rift resulting from a previous RRR triple junction [e.g. Franke et al., 2002]. The structural interpretation

Midterm Follow-up of Treating Volar Marginal Rim Fractures with Variable Angle Lcp Volar Rim Distal Radius Plates.

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Goorens, Chul Ki; Geeurickx, Stijn; Wernaers, Pascal; Staelens, Barbara; Scheerlinck, Thierry; Goubau, Jean

2017-06-01

Specific treatment of the volar marginal rim fragment of distal radius fractures avoids occurance of volar radiocarpal dislocation. Although several fixation systems are available to capture this fragment, adequately maintaining internal fixation is difficult. We present our experience of the first 10 cases using the 2.4 mm variable angle LCP volar rim distal radius plate (Depuy Synthes®, West Chester, US), a low-profile volar rim-contouring plate designed for distal plate positioning and stable buttressing of the volar marginal fragment. Follow-up patient satisfaction, range of motion, grips strength, functional scoring with the QuickDASH and residual pain with a numeric rating scale were assessed. Radiological evaluation consisted in evaluating fracture consolidation, ulnar variance, volar angulation and maintenance of the volar rim fixation. The female to male ratio was 5:5 and the mean age was 52.2 (range, 17-80) years. The mean follow-up period was 11 (range, 5-19) months postoperatively. Patient satisfaction was high. The mean total flexion/extension range was 144° (range, 100-180°) compared to the contralateral uninjured side 160° (range, 95-180°). The mean total pronation/supination range was 153° (range, 140-180°) compared to the contralateral uninjured side 170° (range, 155-180°). Mean grip strength was 14 kg (range, 9-22), compared to the contralateral uninjured side 20 kg (range, 12-25 kg). Mean pre-injury level activity QuickDASH was 23 (range, 0-34.1), while post-recovery QuickDASH was 25 (range 0-43.2). Residual pain was 1.5 on the visual numerical pain rating scale. Radiological evaluation revealed in all cases fracture consolidation, satisfactory reconstruction of ulnar variance, volar angulation and volar rim. We encountered no flexor tendon complications, although plate removal was systematically performed after fracture consolidation. The 2.4 mm variable angle LCP volar rim distal radius plates is a valid treatment option for treating

Safety margins of operating reactors. Analysis of uncertainties and implications for decision making

International Nuclear Information System (INIS)

2003-01-01

Maintaining safety in the design and operation of nuclear power plants (NPPs) is a very important task under the conditions of a challenging environment, affected by the deregulated electricity market and implementation of risk informed regulations. In Member States, advanced computer codes are widely used as safety analysis tools in the framework of licensing of new NPP projects, safety upgrading programmes of existing NPPs, periodic safety reviews, renewal of operating licences, use of the safety margins for reactor power uprating, better utilization of nuclear fuel and higher operational flexibility, for justification of lifetime extensions, development of new emergency operating procedures, analysis of operational events, and development of accident management programmes. The issue of inadequate quality of safety analysis is becoming important due to a general tendency to use advanced tools for better establishment and utilization of safety margins, while the existence of such margins assure that NPPs operate safely in all modes of operation and at all times. The most important safety margins relate to physical barriers against release of radioactive material, such as fuel matrix and fuel cladding, reactor coolant system boundary, and the containment. Typically, safety margins are determined with use of computational tools for safety analysis. Advanced best estimate computer codes are suggested e.g. in the IAEA Safety Guide on Safety Assessment and Verification for Nuclear Power Plants to be used for current safety analysis. Such computer codes require their careful application to avoid unjustified reduction in robustness of the reactor safety. The issue of uncertainties in safety analyses and their impact on evaluation of safety margins is addressed in a number of IAEA guidance documents, in particular in the Safety Report on Accident Analysis for Nuclear Power Plants. It is also discussed in various technical meetings and workshops devoted to this area. The

Histopathological Validation of the Surface-Intermediate-Base Margin Score for Standardized Reporting of Resection Technique during Nephron Sparing Surgery.

Science.gov (United States)

Minervini, Andrea; Campi, Riccardo; Kutikov, Alexander; Montagnani, Ilaria; Sessa, Francesco; Serni, Sergio; Raspollini, Maria Rosaria; Carini, Marco

2015-10-01

The surface-intermediate-base margin score is a novel standardized reporting system of resection techniques during nephron sparing surgery. We validated the surgeon assessed surface-intermediate-base score with microscopic histopathological assessment of partial nephrectomy specimens. Between June and August 2014 data were prospectively collected from 40 consecutive patients undergoing nephron sparing surgery. The surface-intermediate-base score was assigned to all cases. The score specific areas were color coded with tissue margin ink and sectioned for histological evaluation of healthy renal margin thickness. Maximum, minimum and mean thickness of healthy renal margin for each score specific area grade (surface [S] = 0, S = 1 ; intermediate [I] or base [B] = 0, I or B = 1, I or B = 2) was reported. The Mann-Whitney U and Kruskal-Wallis tests were used to compare the thickness of healthy renal margin in S = 0 vs 1 and I or B = 0 vs 1 vs 2 grades, respectively. Maximum, minimum and mean thickness of healthy renal margin was significantly different among score specific area grades S = 0 vs 1, and I or B = 0 vs 1, 0 vs 2 and 1 vs 2 (p <0.001). The main limitations of the study are the low number of the I or B = 1 and I or B = 2 samples and the assumption that each microscopic slide reflects the entire score specific area for histological analysis. The surface-intermediate-base scoring method can be readily harnessed in real-world clinical practice and accurately mirrors histopathological analysis for quantification and reporting of healthy renal margin thickness removed during tumor excision. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

California Drug and Alcohol Treatment Assessment (CALDATA-1991-1993)

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U.S. Department of Health & Human Services — The California Drug and Alcohol Treatment Assessment (CALDATA) was designed to study the costs, benefits, and effectiveness of the state's alcohol and drug treatment...

Breast conservation therapy based on liberal selection criteria and less extensive surgery. Analysis of cases with positive margins

International Nuclear Information System (INIS)

Amemiya, Atsushi; Kondo, Makoto

1999-01-01

The relationship between the margin status and the risk of in-breast recurrence (IBR) is an important consideration in patients treated with breast conservation therapy but has not been defined adequately. To address this issue, 1533 clinical stage I and II patients who completed irradiation therapy between 1983 and 1998 were evaluated. Only selection criterion was whether she could be satisfied with cosmesis after lumpectomy. Size and location of the tumor, nodal status, histology and age were not primary consideration. The tumor was excised in such a way to obtain macroscopically clear margins. The breast was treated with 50 Gy of external irradiation but without boost. Margins were evaluated by serially sectioning of the specimen and the margin was judged positive only when cancer cells were present on the inked surface. Margins were also evaluated by scratch cytology. Seventy two IBR were experienced within 5 years. Only age and margin status were found to be independent risk factors. Five-year IBR rate with negative and positive margins was 3.7% and 10.0%, respectively. In patients with positive margins, number of positive site and positive cytology were independent risk factor for IBR. IBR rate among patients with focally involved margins by non-comedo, comedo and invasive ca, was 0.0%, 3.5%, and 8.7%, respectively. IBR rate in more than focal involvement by non-comedo, comedo, and invasive ca, was 4.0%, 33.0% and 30.0%, respectively. If histologically positive margin was also positive cytologically, IBR was 14.8%, whereas only 3.6% if negative cytologically. Even with liberal patient selection and less extensive local treatment, adequate local control can be obtained, provided that margins are histologically and/or cytologically negative. Focal margin involvement by DCIS or more than focal involvement by non-comedo type DCIS does not jeopardize local control. More than focal involvement by comedo DCIS or involvement by invasive ca results in high IBR rate

Limited Margin Radiation Therapy for Children and Young Adults With Ewing Sarcoma Achieves High Rates of Local Tumor Control

Energy Technology Data Exchange (ETDEWEB)

Talleur, Aimee C.; Navid, Fariba [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Spunt, Sheri L. [Department of Pediatrics, Stanford University School of Medicine, Stanford, California (United States); McCarville, M. Beth [Department of Diagnostic Imaging, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu, John; Mao, Shenghua [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Davidoff, Andrew M. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Department of Surgery, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee (United States); Neel, Michael D. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Krasin, Matthew J., E-mail: matthew.krasin@stjude.org [Department of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

2016-09-01

Purpose: To determine the rate of local failure using focal conformal, limited margin radiation therapy (RT) and dose escalation for tumors ≥8 cm (greatest dimension at diagnosis) in children and young adults with Ewing sarcoma (EWS). Methods and Materials: Eligible patients with EWS were treated on a phase 2 institutional trial of focal conformal, limited margin RT using conformal or intensity modulated techniques. The treatment volume incorporated a 1-cm constrained margin around the gross tumor. Unresected tumors, <8 cm at diagnosis, received a standard dose of 55.8 Gy and tumors ≥8 cm, an escalated dose to 64.8 Gy. Patients with microscopic residual disease after resection received adjuvant RT to 50.4 Gy. Adjuvant brachytherapy was permitted in selected patients. Results: Forty-five patients were enrolled: 26 with localized and 19 with metastatic disease. Median (range) age, tumor size, and follow-up were 13.0 years (2.9-24.7 years), 9.0 cm (2.4-17.0 cm), and 54.5 months (1.9-122.2 months), respectively. All patients received systemic chemotherapy. The median (range) RT dose for all patients was 56.1 Gy (45-65.5 Gy). Seventeen patients received adjuvant, 16 standard-dose, and 12 escalated-dose RT. Failures included 1 local, 10 distant, and 1 local/distant. The estimated 10-year cumulative incidence of local failure was 4.4% ± 3.1%, with no statistical difference seen between RT treatment groups and no local failures in the escalated-dose RT treatment group. Conclusions: Treatment with focal conformal, limited margin RT, including dose escalation for larger tumors, provides favorable local tumor control in EWS.

Limited Margin Radiation Therapy for Children and Young Adults With Ewing Sarcoma Achieves High Rates of Local Tumor Control

International Nuclear Information System (INIS)

Talleur, Aimee C.; Navid, Fariba; Spunt, Sheri L.; McCarville, M. Beth; Wu, John; Mao, Shenghua; Davidoff, Andrew M.; Neel, Michael D.; Krasin, Matthew J.

2016-01-01

Purpose: To determine the rate of local failure using focal conformal, limited margin radiation therapy (RT) and dose escalation for tumors ≥8 cm (greatest dimension at diagnosis) in children and young adults with Ewing sarcoma (EWS). Methods and Materials: Eligible patients with EWS were treated on a phase 2 institutional trial of focal conformal, limited margin RT using conformal or intensity modulated techniques. The treatment volume incorporated a 1-cm constrained margin around the gross tumor. Unresected tumors, <8 cm at diagnosis, received a standard dose of 55.8 Gy and tumors ≥8 cm, an escalated dose to 64.8 Gy. Patients with microscopic residual disease after resection received adjuvant RT to 50.4 Gy. Adjuvant brachytherapy was permitted in selected patients. Results: Forty-five patients were enrolled: 26 with localized and 19 with metastatic disease. Median (range) age, tumor size, and follow-up were 13.0 years (2.9-24.7 years), 9.0 cm (2.4-17.0 cm), and 54.5 months (1.9-122.2 months), respectively. All patients received systemic chemotherapy. The median (range) RT dose for all patients was 56.1 Gy (45-65.5 Gy). Seventeen patients received adjuvant, 16 standard-dose, and 12 escalated-dose RT. Failures included 1 local, 10 distant, and 1 local/distant. The estimated 10-year cumulative incidence of local failure was 4.4% ± 3.1%, with no statistical difference seen between RT treatment groups and no local failures in the escalated-dose RT treatment group. Conclusions: Treatment with focal conformal, limited margin RT, including dose escalation for larger tumors, provides favorable local tumor control in EWS.

The Seismicity of Two Hyperextended Margins

Science.gov (United States)

Redfield, Tim; Terje Osmundsen, Per

2013-04-01

A seismic belt marks the outermost edge of Scandinavia's proximal margin, inboard of and roughly parallel to the Taper Break. A similar near- to onshore seismic belt runs along its inner edge, roughly parallel to and outboard of the asymmetric, seaward-facing escarpment. The belts converge at both the northern and southern ends of Scandinavia, where crustal taper is sharp and the proximal margin is narrow. Very few seismic events have been recorded on the intervening, gently-tapering Trøndelag Platform. Norway's distribution of seismicity is systematically ordered with respect to 1) the structural templates of high-beta extension that shaped the thinning gradient during Late Jurassic or Early Cretaceous time, and 2) the topographically resurgent Cretaceous-Cenozoic "accommodation phase" family of escarpments that approximate the innermost limit of crustal thinning [See Redfield and Osmundsen (2012) for diagrams, definitions, discussion, and supporting citations.] Landwards from the belt of earthquake epicenters that mark the Taper Break the crust consistently thickens, and large fault arrays tend to sole out at mid crustal levels. Towards the sea the crystalline continental crust is hyperextended, pervasively faulted, and generally very thin. Also, faulting and serpentinization may have affected the uppermost parts of the distal margin's lithospheric mantle. Such contrasting structural conditions may generate a contrasting stiffness: for a given stress, more strain can be accommodated in the distal margin than in the less faulted proximal margin. By way of comparison, inboard of the Taper Break on the gently-tapered Trøndelag Platform, faulting was not penetrative. There, similar structural conditions prevail and proximal margin seismicity is negligible. Because stress concentration can occur where material properties undergo significant contrast, the necking zone may constitute a natural localization point for post-thinning phase earthquakes. In Scandinavia

The Marginal Source of Finance

OpenAIRE

Lindhe, Tobias

2002-01-01

This paper addresses the ongoingdebate on which view of equity, traditional or new, that best describes firm behavior. According to the traditional view, the marginal source of finance is new equity, whereas under to the new view, marginal financing comes from retained earnings. In the theoretical part, we set up a model where the firm faces a cost of adjusting the dividend level because of an aggravated free cash flow problem. The existence of such a cost - which has been used in arguing the...

Negative predictive value of ultrasound in predicting tumor-free margins in specimen sonography

International Nuclear Information System (INIS)

Naz, S.; Hafeez, S.; Hussain, Z.; Hilal, K.

2017-01-01

Objective: To evaluate the success of ultrasound in post-excision specimen visualization, and negative predictive value of ultrasound for estimation of tumor-free margins using histopathology as the gold standard. Study Design: Cross-sectional analytical study. Place and Duration of Study: The Aga Khan University Hospital, Karachi, Pakistan, from May 2010 till January 2013. Methodology: Sonography of all breast nodules was done before and after exicision by two female radiologists with at least five years clinical experience. All surgeries were performed by the same referring breast surgeons. All nodules were non-palpable and had histopathology as well as specimen sonography performed at AKUH. Subjects were excluded, if histopathology was not available, post-procedure sonogram not done or done in another hospital and nodules that were not seen on ultrasound. After needle localization in 47 patients using ultrasound and in 7 patients using mammogram was done, sonogram was conducted in all 54 lesions. These were then assessed by ultrasound for detection of lesion and tumor-free margins in malignant lesion. Post-excision ultrasound was performed for the evaluation of lesion whether visualized or absent with localizing needle in situ, lesion dimensions, depth measurement between the superior margin of the lesion and its edge. Results: All 54 lesions were present on post-exicison scan, out of which 28 were documented as malignant and 26 as benign. Ultrasound declared all specimens as tumor-free. On histopathology, two lesions were documented as having tumor-positive margins and were proven to be invasive lobular carcinoma. Therefore, the negative predictive value of the specimen sonography for margin detection was 26/28 (92.8%). Conclusion: Ultrasound of the excised breast tumor specimen is a simple and reliable technique for confirmation of the tumor-free margins in non-palpable breast lesions. (author)

Quantifying the margin sharpness of lesions on radiological images for content-based image retrieval

International Nuclear Information System (INIS)

Xu Jiajing; Napel, Sandy; Greenspan, Hayit; Beaulieu, Christopher F.; Agrawal, Neeraj; Rubin, Daniel

2012-01-01

. Equivalence across deformations was assessed using Schuirmann's paired two one-sided tests. Results: In simulated images, the concordance correlation between measured gradient and actual gradient was 0.994. The mean (s.d.) and standard deviation NDCG score for the retrieval of K images, K = 5, 10, and 15, were 84% (8%), 85% (7%), and 85% (7%) for CT images containing liver lesions, and 82% (7%), 84% (6%), and 85% (4%) for CT images containing lung nodules, respectively. The authors’ proposed method outperformed the two existing margin characterization methods in average NDCG scores over all K, by 1.5% and 3% in datasets containing liver lesion, and 4.5% and 5% in datasets containing lung nodules. Equivalence testing showed that the authors’ feature is more robust across all margin deformations (p < 0.05) than the two existing methods for margin sharpness characterization in both simulated and clinical datasets. Conclusions: The authors have described a new image feature to quantify the margin sharpness of lesions. It has strong correlation with known margin sharpness in simulated images and in clinical CT images containing liver lesions and lung nodules. This image feature has excellent performance for retrieving images with similar margin characteristics, suggesting potential utility, in conjunction with other lesion features, for content-based image retrieval applications.

Evaluation of LBB margin of nuclear piping systems

International Nuclear Information System (INIS)

Hwang, Il Soon; Kim, Ji Hyeon; Oh, Yeong Jin; Lim, Jun; Kim, In Seob; Kim, Yong Seon; Lee, Joo Seok

1999-04-01

Most of previous elastic-plastic fracture studies for LBB assessment of low alloy steel piping have been focused on base metals and weld metals. In contract, the heat affected zone of welded pipe has not been studied in detail primarily because the size of heat affected zone in welded pipe os too small to make specimens for mechanical properties measurement. When structural members are joined by welding, the base metal is heated to its melting point and then cooled rapidly. As a result of this very severe thermal cycle, mechanical properties in the heat affected zone can be degraded by grain coarsening, the precipitation and the segregation of trace impurities. In this study, a thermal and microstructural analysis is performed, and mechanical properties are measured for the weld heat affected zone of SA106Gr.C low allowed piping steel. In addition, inter critical annealing treatment. in two-phase (alpha+gamma) region was performed to investigate the possibilities of improving the toughness and reducing dynamic strain aging (DSA) susceptibility for giving allowable LBB safety margins. From the results, intercritical annealing is shown to give a smaller ductility loss due to DSA than the case of as-received material. Furthermore, the intercritical annealing was able to increase the impact toughness by a factor of 1.5 compared to the as-received material

Evaluation of LBB margin of nuclear piping systems

Energy Technology Data Exchange (ETDEWEB)

Hwang, Il Soon; Kim, Ji Hyeon; Oh, Yeong Jin; Lim, Jun [Seoul Nationl Univ., Seoul (Korea, Republic of); Kim, In Seob; Kim, Yong Seon; Lee, Joo Seok [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1999-04-15

Most of previous elastic-plastic fracture studies for LBB assessment of low alloy steel piping have been focused on base metals and weld metals. In contract, the heat affected zone of welded pipe has not been studied in detail primarily because the size of heat affected zone in welded pipe os too small to make specimens for mechanical properties measurement. When structural members are joined by welding, the base metal is heated to its melting point and then cooled rapidly. As a result of this very severe thermal cycle, mechanical properties in the heat affected zone can be degraded by grain coarsening, the precipitation and the segregation of trace impurities. In this study, a thermal and microstructural analysis is performed, and mechanical properties are measured for the weld heat affected zone of SA106Gr.C low allowed piping steel. In addition, inter critical annealing treatment. in two-phase (alpha+gamma) region was performed to investigate the possibilities of improving the toughness and reducing dynamic strain aging (DSA) susceptibility for giving allowable LBB safety margins. From the results, intercritical annealing is shown to give a smaller ductility loss due to DSA than the case of as-received material. Furthermore, the intercritical annealing was able to increase the impact toughness by a factor of 1.5 compared to the as-received material.

The availability and economic analyses of using marginal land for bioenergy production in China

Science.gov (United States)

Yuqi, Chen; Xudong, Guo; Chunyan, Lv

2017-04-01

In recent years, China has witnessed rapid increase in the dependence of foreign oil import. In 2015, the primary energy consumption of China is 543 million tons, of which 328 million tons was imported. The total amount of imported foreign oil increased from 49.8% in 2008 to 60.41% in 2016. To address the national energy security and GHG emission reduction, China has made considerable progress in expanding renewable energy portfolio, especially liquid biofuels. However, under the pressure of high population and vulnerable food security, China's National Development and Reform Commission (NDRC) ruled that bioenergy is only allowed to be produced using non-cereal feedstock. In addition, the energy crops can only be planted on marginal land, which is the land not suitable for growing field crops due to edaphic and/or climatic limitations, and other environmental risks. Although there have been a number of studies about estimating the marginal land for energy plants' cultivation in China, as to the different definition of marginal land and land use data, the results are quite different. Furthermore, even if there is enough marginal land suitable for energy plants' cultivation, economic viability of cultivating energy plants on marginal land is critical. In order to analyze the availability and economic analyses of the marginal land for bioenergy production strategy, firstly, by using of the latest and most authoritative land use data, this study focused on the assessment of marginal land resources and bioenergy potential by planting five species of energy plants including Cassava, Jatropha curcas, Helianthus tuberous L, Pistacia chinensis, Xanthoceras sorbifolia Bunge. The results indicate that there are 289.71 million ha marginal land can be used for these five energy plants' cultivation, which can produce 24.45 million tons bioethanol and 8.77 million tons of biodiesel. Secondly, based on field survey data and literature reviews, we found that, from the farmers

Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy

International Nuclear Information System (INIS)

Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

2016-01-01

To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1–2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85–6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins.

Tumor-related markers in histologically normal margins correlate with locally recurrent oral squamous cell carcinoma: a retrospective study.

Science.gov (United States)

Wang, Xinhong; Chen, Si; Chen, Xinming; Zhang, Cuicui; Liang, Xueyi

2016-02-01

Oral squamous cell carcinoma (OSCC) is characterized by a high rate of local recurrence (LR) even when the surgical margins are considered histopathologically 'normal'. The aim of our study was to determine the relationship between early tumor-related markers detected in histologically normal margins (HNM) and LR as well as disease-free survival in OSCC. The loss of heterozygosity (LOH) of markers on 9p21 (D9s1747, RPS6, D9s162) and 17p13 (TP53) and the immunostaining results of the corresponding mutant P53, P14, P15, and P16 proteins were assessed and correlated with LR and disease-free survival in 71 OSCC patients who had HNM. Fifteen of 71 patients with HNM developed LR. The presence of the following molecular markers in surgical margins was significantly correlated with the development of LR: LOH on chromosome 9p21 (D9s1747 + RPS6 + D9s162), any LOH, P16, and P53 (chi-square test, P tumor-related markers in histologically 'normal' resection margins may be a useful method for assessing LR in OSCC patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Risk factors for and consequences of inadequate surgical margins in oral squamous cell carcinoma

DEFF Research Database (Denmark)

Lawaetz, Mads; Homøe, Preben

2014-01-01

OBJECTIVE: The purpose of this study was to examine which factors are associated with inadequate surgical margins and to assess the postoperative consequences. STUDY DESIGN: A retrospective cohort of 110 patients with oral squamous cell carcinoma treated with surgery during a 2-year period...

Feasibility of Using the Marginal Blood Vessels as Reference Landmarks for CT Colonography

Science.gov (United States)

Wei, Zhuoshi; Yao, Jianhua; Wang, Shijun; Liu, Jiamin; Dwyer, Andrew J.; Pickhardt, Perry J.; Nowinski, Wieslaw L.; Summers, Ronald M.

2015-01-01

OBJECTIVE The purpose of this study was to show the spatial relationship of the colonic marginal blood vessels and the teniae coli on CT colonography (CTC) and the use of the marginal blood vessels for supine-prone registration of polyps and for determination of proper connectivity of collapsed colonic segments. MATERIALS AND METHODS We manually labeled the marginal blood vessels on 15 CTC examinations. Colon segmentation, centerline extraction, teniae detection, and teniae identification were automatically performed. For assessment of their spatial relationships, the distances from the marginal blood vessels to the three teniae coli and to the colon were measured. Student t tests (paired, two-tailed) were performed to evaluate the differences among these distances. To evaluate the reliability of the marginal vessels as reference points for polyp correlation, we analyzed 20 polyps from 20 additional patients who underwent supine and prone CTC. The average difference of the circumferential polyp position on the supine and prone scans was computed. Student t tests (paired, two-tailed) were performed to evaluate the supine-prone differences of the distance. We performed a study on 10 CTC studies from 10 patients with collapsed colonic segments by manually tracing the marginal blood vessels near the collapsed regions to resolve the ambiguity of the colon path. RESULTS The average distances (± SD) from the marginal blood vessels to the tenia mesocolica, tenia omentalis, and tenia libera were 20.1 ± 3.1 mm (95% CI, 18.5–21.6 mm), 39.5 ± 4.8 mm (37.1–42.0 mm), and 36.9 ± 4.2 mm (34.8–39.1 mm), respectively. Pairwise comparison showed that these distances to the tenia libera and tenia omentalis were significantly different from the distance to the tenia mesocolica (p marginal blood vessels to the colon wall was 15.3 ± 2.0 mm (14.2–16.3 mm). For polyp localization, the average difference of the circumferential polyp position on the supine and prone scans was 9

Set-up errors analyses in IMRT treatments for nasopharyngeal carcinoma to evaluate time trends, PTV and PRV margins

Energy Technology Data Exchange (ETDEWEB)

Mongioj, Valeria (Dept. of Medical Physics, Fondazione IRCCS Istituto Nazionale Tumori, Milan (Italy)), e-mail: valeria.mongioj@istitutotumori.mi.it; Orlandi, Ester (Dept. of Radiotherapy, Fondazione IRCCS Istituto Nazionale Tumori, Milan (Italy)); Palazzi, Mauro (Dept. of Radiotherapy, A.O. Niguarda Ca' Granda, Milan (Italy)) (and others)

2011-01-15

Introduction. The aims of this study were to analyze the systematic and random interfractional set-up errors during Intensity Modulated Radiation Therapy (IMRT) in 20 consecutive nasopharyngeal carcinoma (NPC) patients by means of Electronic Portal Images Device (EPID), to define appropriate Planning Target Volume (PTV) and Planning Risk Volume (PRV) margins, as well as to investigate set-up displacement trend as a function of time during fractionated RT course. Material and methods. Before EPID clinical implementation, an anthropomorphic phantom was shifted intentionally 5 mm to all directions and the EPIs were compared with the digitally reconstructed radiographs (DRRs) to test the system's capability to recognize displacements observed in clinical studies. Then, 578 clinical images were analyzed with a mean of 29 images for each patient. Results. Phantom data showed that the system was able to correct shifts with an accuracy of 1 mm. As regards clinical data, the estimated population systematic errors were 1.3 mm for left-right (L-R), 1 mm for superior-inferior (S-I) and 1.1 mm for anterior-posterior (A-P) directions, respectively. Population random errors were 1.3 mm, 1.5 mm and 1.3 mm for L-R, S-I and A-P directions, respectively. PTV margin was at least 3.4, 3 and 3.2 mm for L-R, S-I and A-P direction, respectively. PRV margins for brainstem and spinal cord were 2.3, 2 and 2.1 mm and 3.8, 3.5 and 3.2 mm for L-R, A-P and S-I directions, respectively. Set-up error displacements showed no significant changes as the therapy progressed (p>0.05), although displacements >3 mm were found more frequently when severe weight loss or tumor nodal shrinkage occurred. Discussion. These results enable us to choose margins that guarantee with sufficient accuracy the coverage of PTVs and organs at risk sparing. Collected data confirmed the need for a strict check of patient position reproducibility in case of anatomical changes

Marginal Zone Lymphoma Complicated by Protein Losing Enteropathy

Directory of Open Access Journals (Sweden)

Nadine Stanek

2016-01-01

Full Text Available Protein losing enteropathy (PLE refers to excessive intestinal protein loss, resulting in hypoalbuminemia. Underlying pathologies include conditions leading to either reduced intestinal barrier or lymphatic congestion. We describe the case of a patient with long-lasting diffuse abdominal problems and PLE. Repetitive endoscopies were normal with only minimal lymphangiectasia in biopsies. Further evaluations revealed an indolent marginal zone lymphoma with minor bone marrow infiltration. Monotherapy with rituximab decreased bone marrow infiltration of the lymphoma but did not relieve PLE. Additional treatments with steroids, octreotide, a diet devoid of long-chain fatty-acids, and parenteral nutrition did not prevent further clinical deterioration with marked weight loss (23 kg, further reduction in albumin concentrations (nadir 8 g/L, and a pronounced drop in performance status. Finally, immunochemotherapy with rituximab and bendamustine resulted in hematological remission and remarkable clinical improvement. 18 months after therapy the patient remains free of gastrointestinal complaints and has regained his body weight with normal albumin levels. We demonstrate a case of PLE secondary to indolent marginal zone lymphoma. No intestinal pathologies were detected, contrasting a severe and almost lethal clinical course. Immunochemotherapy relieved lymphoma and PLE, suggesting that a high suspicion of lymphoma is warranted in otherwise unexplained cases of PLE.

Influence of Different Implant Geometry in Clinical Longevity and Maintenance of Marginal Bone: A Systematic Review.

Science.gov (United States)

Lovatto, Sabrina Telles; Bassani, Rafaela; Sarkis-Onofre, Rafael; Dos Santos, Mateus Bertolini Fernandes

2018-03-26

To assess, through a systematic review, the influence of different implant geometries on clinical longevity and maintenance of marginal bone tissue. An electronic search was conducted in MEDLINE, Scopus, and Web of Science databases, limited to studies written in English from 1996 to 2017 using specific search strategies. Only randomized controlled trials (RCTs) that compared dental implants and their geometries were included. Two reviewers independently selected studies, extracted data, and assessed the risk of bias of included studies. From the 4006 references identified by the search, 24 were considered eligible for full-text analysis, after which 10 studies were included in this review. A similar behavior of marginal bone loss between tapered and cylindrical geometries was observed; however, implants that had micro-threads in the neck presented a slight decrease of marginal bone loss compared to implants with straight or smooth neck. Success and survival rates were high, with cylindrical implants presenting higher success and survival rates than tapered ones. Implant geometry seems to have little influence on marginal bone loss (MBL) and survival and success rates after 1 year of implant placement; however, the evidence in this systematic review was classified as very low due to limitations such as study design, sample size, and publication bias. Thus, more well-designed RCTs should be conducted to provide evidence regarding the influence of implant geometry on MBL and survival and success rates after 1 year of implant placement. © 2018 by the American College of Prosthodontists.

TREATMENT OF CANCER IN THE OLDER AGED PERSON

Directory of Open Access Journals (Sweden)

Lodovico Balducci

2010-05-01

Full Text Available

margin: 0cm 0cm 0pt;"> Cancer is a disease of aging .  Currently 50% of all malignancies occur in individuals 65 and over and by the year 2030 older individuals will account for 70% of all neoplasms.

margin: 0cm 0cm 0pt;"> With the aging of the population the management of cancer in the older person with chemotherapy is beoming increasingly common. This treatment may be  safe and effective if some appropriate measures are taken, including, an assessment of the physiologic age of each patient, modification of doses according to the renal function, use of meyelopoietic growth factors prophylactically in presence of moderately toxic chemotherapy, and provision of an adequate caregiver. Cure, prolongation of survival, and symptom palliation are universal goals of medical treatment.   Prolongation of active life expectancy  should be added to the treatment goal of the older aged person .

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Breast MR imaging for the assessment of residual disease following initial surgery for breast cancer with positive margins

Energy Technology Data Exchange (ETDEWEB)

Krammer, Julia [University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany); Memorial Sloan-Kettering Cancer Center, Breast Imaging Section, Department of Radiology, New York, NY (United States); Price, Elissa R. [University of California, San Francisco, Department of Radiology and Biomedical Imaging, Division of Women' s Imaging, San Francisco, CA (United States); Jochelson, Maxine S.; Watson, Elizabeth; Morris, Elizabeth A. [Memorial Sloan-Kettering Cancer Center, Breast Imaging Section, Department of Radiology, New York, NY (United States); Murray, Melissa P. [Memorial Sloan-Kettering Cancer Center, Department of Pathology, New York, NY (United States); Schoenberg, Stefan O. [University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany)

2017-11-15

To determine the accuracy of post-operative MR in predicting residual disease in women with positive margins, emphasizing the size thresholds at which residual disease can be confidently identified. This IRB-approved HIPAA-compliant retrospective study included 175 patients with MR after positive margins following initial surgery for breast cancer. Two expert readers independently re-evaluated MR images for evidence of residual disease at the surgical cavity and multifocal/multicentric disease. All patients underwent definitive surgery and MR findings were correlated to histopathology. 139/175 (79.4%) patients had residual disease at surgery. Average overall sensitivity, specificity, PPV and NPV for residual disease at the surgical cavity were 73%, 72%, 91% and 45%, respectively. The readers identified 42/45 (93%, reader 1) and 43/45 (95%, reader 2) patients with residual invasive disease at the cavity of ≥5 mm and 22/22 (100%, both readers) patients with disease ≥10 mm. Average sensitivity, specificity, PPV and NPV for unknown multifocal/multicentric disease were 90%, 96%, 93% and 86%, respectively. Post-operative breast MR can accurately depict ≥5-mm residual disease at the surgical cavity and unsuspected multifocal/multicentric disease. These findings have the potential to lead to more appropriate selection of second surgical procedures in women with positive margins. (orig.)

Breast MR imaging for the assessment of residual disease following initial surgery for breast cancer with positive margins

International Nuclear Information System (INIS)

Krammer, Julia; Price, Elissa R.; Jochelson, Maxine S.; Watson, Elizabeth; Morris, Elizabeth A.; Murray, Melissa P.; Schoenberg, Stefan O.

2017-01-01

To determine the accuracy of post-operative MR in predicting residual disease in women with positive margins, emphasizing the size thresholds at which residual disease can be confidently identified. This IRB-approved HIPAA-compliant retrospective study included 175 patients with MR after positive margins following initial surgery for breast cancer. Two expert readers independently re-evaluated MR images for evidence of residual disease at the surgical cavity and multifocal/multicentric disease. All patients underwent definitive surgery and MR findings were correlated to histopathology. 139/175 (79.4%) patients had residual disease at surgery. Average overall sensitivity, specificity, PPV and NPV for residual disease at the surgical cavity were 73%, 72%, 91% and 45%, respectively. The readers identified 42/45 (93%, reader 1) and 43/45 (95%, reader 2) patients with residual invasive disease at the cavity of ≥5 mm and 22/22 (100%, both readers) patients with disease ≥10 mm. Average sensitivity, specificity, PPV and NPV for unknown multifocal/multicentric disease were 90%, 96%, 93% and 86%, respectively. Post-operative breast MR can accurately depict ≥5-mm residual disease at the surgical cavity and unsuspected multifocal/multicentric disease. These findings have the potential to lead to more appropriate selection of second surgical procedures in women with positive margins. (orig.)

The homogeneous marginal utility of income assumption

NARCIS (Netherlands)

Demuynck, T.

2015-01-01

We develop a test to verify if every agent from a population of heterogeneous consumers has the same marginal utility of income function. This homogeneous marginal utility of income assumption is often (implicitly) used in applied demand studies because it has nice aggregation properties and