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Sample records for hypo-fractionated conformal radiation

  1. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed after Segmental Mastectomy

    Science.gov (United States)

    2007-07-01

    include area code) tandard Form 298 (Rev. 8-98) •rescribed by ANSI SW. Z39.18 "able of Contents ntroduction tody Cev Research Accomplishments...protocols. Int J Radiat Oncol Biol Phys. 2005 July :62(3):943-944. Formenti SC. Wernicke AG, DeWyngaert JK. External beam partial-breast radiotherapy...friendly regimen than the nandard 5-7 weeks of Dostoperative radiotherapy (RT) has ecenilv become an area of intense research, because in :enain

  2. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy

    Science.gov (United States)

    2005-07-01

    invasive breast cancer. Menopause was defined as at least 2 years without menstrual periods. In patients who had undergone prior hysterectomy, follicle... Recovery kinetics deduced from continuous low 73. Vicini FA, Kestin L, Chen P, et al. Limited-field radiation dose-rate experiments. Radiother Oncol...xx: © 2005 Elsevier Inc. All rights reserved. "A A though most studies treating patientswith partial-breast will require the procedure to be aborted , as

  3. Hypo-fractionated radiation, magnetic nanoparticle hyperthermia and a viral immunotherapy treatment of spontaneous canine cancer

    Science.gov (United States)

    Hoopes, P. Jack; Moodie, Karen L.; Petryk, Alicia A.; Petryk, James D.; Sechrist, Shawntel; Gladstone, David J.; Steinmetz, Nicole F.; Veliz, Frank A.; Bursey, Alicea A.; Wagner, Robert J.; Rajan, Ashish; Dugat, Danielle; Crary-Burney, Margaret; Fiering, Steven N.

    2017-02-01

    It has recently been shown that cancer treatments such as radiation and hyperthermia, which have conventionally been viewed to have modest immune based anti-cancer effects, may, if used appropriately stimulate a significant and potentially effective local and systemic anti-cancer immune effect (abscopal effect) and improved prognosis. Using eight spontaneous canine cancers (2 oral melanoma, 3 oral amelioblastomas and 1 carcinomas), we have shown that hypofractionated radiation (6 x 6 Gy) and/or magnetic nanoparticle hyperthermia (2 X 43°C / 45 minutes) and/or an immunogenic virus-like nanoparticle (VLP, 2 x 200 μg) are capable of delivering a highly effective cancer treatment that includes an immunogenic component. Two tumors received all three therapeutic modalities, one tumor received radiation and hyperthermia, two tumors received radiation and VLP, and three tumors received only mNP hyperthermia. The treatment regimen is conducted over a 14-day period. All patients tolerated the treatments without complication and have had local and distant tumor responses that significantly exceed responses observed following conventional therapy (surgery and/or radiation). The results suggest that both hypofractionated radiation and hyperthermia have effective immune responses that are enhanced by the intratumoral VLP treatment. Molecular data from these tumors suggest Heat Shock Protein (HSP) 70/90, calreticulin and CD47 are targets that can be exploited to enhance the local and systemic (abscopal effect) immune potential of radiation and hyperthermia cancer treatment.

  4. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy

    National Research Council Canada - National Science Library

    Formenti, Silvia C

    2005-01-01

    ... (5 fractions in 2 weeks) directed to the original tumor bed with margins in a selected subset of post-menopausal women with breast cancer with a very low risk for local recurrence elsewhere in the breast...

  5. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed after Segmental Mastectomy

    National Research Council Canada - National Science Library

    Formenti, Silvia C

    2007-01-01

    ... (5 fractions in 2 weeks)directed to the original tumor bed with margins in a selected subset of post-menopausal women with breast cancer with a very low risk for local risk for local recurrence elsewhere in the breast...

  6. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed After Segmental Mastectomy

    Science.gov (United States)

    2004-07-01

    breast conserving surgery for early-stage breast cancer. San Antonio Breast Cancer Symposium. San Antonio , Texas; 2003. 5. Ellerin BE SJ, Formenti SC...surgery for early-stage breast cancer., San Antonio Breast Cancer Symposium. San Antonio , Texas, 2003 2. Ellerin BE SJ, Formenti SC.: A systematic...cancer. J Clin Oncol 2001; 19:1993-2001. 78. Formenti SC, Lucas G, Ibarra JA, et al. Initial brachytherapy in the 69. Perera F, Engel J, Holliday R, et al

  7. Hypo fractionated prostate treatment by volumearcotherapy modulated; Tratamiento hipofraccionado de prostata mediante arcoterapia volumetria modulada

    Energy Technology Data Exchange (ETDEWEB)

    Clemente Gutierrez, F.; Perez Vara, C.; Prieto Villacorta, M.

    2013-07-01

    Several studies have been proposed over the years schemes of hypo-fractionated treatment for prostate cancer. Such schemes have been designed in order to increase local control of the disease and reduce complications. They are in addition a clear improvement from the point of view logistical and organizational for treatment centres and the patient. the hypo-fractionated treatments are possible because the ratio a/b for prostate carcinoma is comparable, and even below, the surrounding healthy tissues. This work presents the scheme adopted in our Center for the hypo-fractionated treatment of the cancer of prostate by arco therapy volumetric modulated. (Author)

  8. SU-E-T-776: Use of Quality Metrics for a New Hypo-Fractionated Pre-Surgical Mesothelioma Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, S; Mehta, V [Swedish Cancer Institute, Seattle, WA (United States)

    2015-06-15

    Purpose: The “SMART” (Surgery for Mesothelioma After Radiation Therapy) approach involves hypo-fractionated radiotherapy of the lung pleura to 25Gy over 5 days followed by surgical resection within 7. Early clinical results suggest that this approach is very promising, but also logistically challenging due to the multidisciplinary involvement. Due to the compressed schedule, high dose, and shortened planning time, the delivery of the planned doses were monitored for safety with quality metric software. Methods: Hypo-fractionated IMRT treatment plans were developed for all patients and exported to Quality Reports™ software. Plan quality metrics or PQMs™ were created to calculate an objective scoring function for each plan. This allows for an objective assessment of the quality of the plan and a benchmark for plan improvement for subsequent patients. The priorities of various components were incorporated based on similar hypo-fractionated protocols such as lung SBRT treatments. Results: Five patients have been treated at our institution using this approach. The plans were developed, QA performed, and ready within 5 days of simulation. Plan Quality metrics utilized in scoring included doses to OAR and target coverage. All patients tolerated treatment well and proceeded to surgery as scheduled. Reported toxicity included grade 1 nausea (n=1), grade 1 esophagitis (n=1), grade 2 fatigue (n=3). One patient had recurrent fluid accumulation following surgery. No patients experienced any pulmonary toxicity prior to surgery. Conclusion: An accelerated course of pre-operative high dose radiation for mesothelioma is an innovative and promising new protocol. Without historical data, one must proceed cautiously and monitor the data carefully. The development of quality metrics and scoring functions for these treatments allows us to benchmark our plans and monitor improvement. If subsequent toxicities occur, these will be easy to investigate and incorporate into the

  9. Tcp and NTCP radiobiological models: conventional and hypo fractionated treatments in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A.; Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Resendiz G, G.; Posadas V, A. [Hospital Angeles Lomas, Av. Vialidad de la Barranca s/n, Col. Valle de las Palmas, 52763 Huixquilucan de Degallado, Estado de Mexico (Mexico); Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan, Esq. Jesus Carranza s/n, Col. Moderna de la Cruz, 50180 Toluca, Estado de Mexico (Mexico); Rodriguez L, A.; Flores C, J. M., E-mail: armando.astudillo@inin.gob.mx [Hospital Medica Sur, Puente de Piedra 150, Col. Toriello Guerra, 14050 Tlalpan, Mexico D. F. (Mexico)

    2015-10-15

    The hypo and conventional fractionated schedules performance were compared in terms of the tumor control and the normal tissue complications. From the records of ten patients, treated for adenocarcinoma and without mastectomy, the dose-volume histogram was used. Using radiobiological models the probabilities for tumor control and normal tissue complications were calculated. For both schedules the tumor control was approximately the same. However, the damage in the normal tissue was larger in conventional fractionated schedule. This is important because patients assistance time to their fractions (15 fractions/25 fractions) can be optimized. Thus, the hypo fractionated schedule has suitable characteristics to be implemented. (Author)

  10. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP; Tratamiento hipofraccionado en radioterapia: modelos radiobiologicos TCP y NTCP

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A. J.; Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Resendiz G, G., E-mail: lydia.paredes@inin.gob.mx [Hospital Medica Sur, Departamento de Radioterapia, Puente de Piedra 150, Col. Toriello Guerra, 14050 Mexico D. F. (Mexico)

    2014-08-15

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  11. Advanced Small Animal Conformal Radiation Therapy Device.

    Science.gov (United States)

    Sharma, Sunil; Narayanasamy, Ganesh; Przybyla, Beata; Webber, Jessica; Boerma, Marjan; Clarkson, Richard; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J

    2017-02-01

    We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made "gantry" and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

  12. SU-F-T-196: Hypo-Fractionation with Intensity Modulated Proton Therapy for Unilateral Metallic Prosthesis Prostate Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Rana, S; Park, S [McLaren Proton Therapy Center, Karmanos Cancer Institute at McLaren-Flint, Flint, MI (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States); Zhang, Y [University of Cincinnati Medical Center, Liberty Township, OH (United States); Pokharel [21st Century Oncology, Estero, FL (United States); Cheng, C [Vantage Oncology, West Hills, CA (United States)

    2016-06-15

    Purpose: The purpose of this study is to investigate the dosimetric feasibility of hypo-fractionated intensity modulated proton therapy (IMPT) for unilateral metallic prosthesis prostate cancer patients based on proton collaborative group (PCG)-GU002-10 (NCT01230866) protocol criteria. Methods: A total of five unilateral metallic prosthesis prostate cancer cases were included in this retrospective study. For each case, IMPT plans were generated for treatment to be delivered with 7.6 Gy[RBE] per fraction in 5 fractions per week for a total dose of 38 Gy(RBE). Each plan was generated using two anterior-oblique beams and one lateral beam. Treatment plans were optimized with an objective meeting PCG-GU002-10 (NCT01230866) protocol criteria: (i) planning target volume (PTV): D99.5% > 36.1 Gy[RBE], (ii) rectum: V24 < 35%, V33.6 < 10%, (iii) bladder: V39 < 8 cc, and (iv) femoral head: V23 < 1cc. Results: All five cases satisfied PTV D99.5% (average=36.82 Gy[RBE]; range, 36.36–37.13 Gy[RBE]). PTV D95% ranged from 36.66 Gy[RBE] to 38.65 Gy[RBE] and PTV V100 ranged from 95.47% to 97.95%. For the rectum, V24 was less than 35% (average=14.07 Gy[RBE]; range, 6.22–18.42%, whereas V33.6 Gy[RBE] was less than 10% (average=6.83; range, 3.06 – 9.15%). Rectal mean dose ranged from 4.22 Gy[RBE] to 9.97 Gy[RBE]. For the bladder, V39 was found to be less than 8 cc (average=3.69 cc; range, 0.19–7.68 cc). Bladder mean dose ranged from 4.22 Gy[RBE] to 18.83 Gy[RBE]. For the femoral head, V23 was 0 in all five cases. Conclusion: All five unilateral metallic prosthesis prostate cancer IMPT plans generated with one lateral and two anterior-oblique beams satisfied the dosimetric criteria of PCG-GU002-10 (NCT01230866) protocol.

  13. Hypo-fractionated stereotactic radiotherapy of five fractions with linear accelerator for vestibular schwannomas: A systematic review and meta-analysis.

    Science.gov (United States)

    Nguyen, Thien; Duong, Courtney; Sheppard, John P; Lee, Seung Jin; Kishan, Amar U; Lee, Percy; Tenn, Stephen; Chin, Robert; Kaprealian, Tania B; Yang, Isaac

    2018-03-01

    Vestibular schwannomas (VS) are benign tumors stemming from the eighth cranial nerve. Treatment options for VS include conservative management, microsurgery, stereotactic radiosurgery, and fractionated radiotherapy. Though microsurgery has been the standard of care for larger lesions, hypo-fractionated stereotactic radiotherapy (hypo-FSRT) is an emerging modality. However, its clinical efficacy and safety have yet to be established. We conducted a systematic review and meta-analysis of manuscripts indexed in PubMed, Scopus, Web of Science, Embase, and Cochrane databases reporting outcomes of VS cases treated with hypo-FSRT. Five studies representing a total of 228 patients were identified. Across studies, the pooled rates of tumor control, hearing, facial nerve, and trigeminal nerve preservation were 95%, 37%, 97%, and 98%. No instances of malignant induction were observed at median follow-up of 34.8 months. Complications included trigeminal neuropathy (n = 3), maxillary paresthesia (n = 1), neuralgia (n = 1), vestibular dysfunction (n = 1), radionecrosis (n = 1), and hydrocephalus (n = 1). Hypo-FSRT may be another useful approach to manage VS, but studies with extended follow-up times are required to establish long-term safety. Copyright © 2018. Published by Elsevier B.V.

  14. Radical hypo-fractionated radiotherapy with volumetric modulated arc therapy in lung cancer. A retrospective study of elderly patients with stage III disease

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, D. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Istituto Clinico Humanitas Cancer Center, Rozzano (Milan) (Italy); De Rose, F.; Navarria, P.; Clerici, E.; Franzese, C.; Comito, T.; Tozzi, A.; Iftode, C.; D' Agostino, G. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Cozzi, L.; Sorsetti, M. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Humanitas University, Department of Biomedical Sciences, Milan (Italy)

    2017-05-15

    This study aimed to analyse the feasibility and acute toxicity of radical hypo-fractionated radiotherapy (RT) for elderly patients with non-small-cell lung cancer (NSCLC). We conducted a retrospective evaluation of treatment with volumetric modulated arc therapy (VMAT) of elderly patients affected by stage III inoperable NSCLC. The dose prescription was 56 Gy in 20 fractions, 55 Gy in 22 fractions, or 50 Gy in 20 fractions. Target volume included only the primary lesion and the infiltrated lymph nodes. The primary end point was acute and late toxicity, while secondary end points were progression-free survival (PFS), and overall survival (OS). In all, 41 patients were included in this analysis. The mean age of the patients was 78.6 years, and 22 patients had staged IIIA while 19 patients had stage IIIB disease. All but one patient had pathological nodal involvement; 15 patients received chemotherapy before RT. Acute grade 1-2 toxicity was recorded in 25 (61%) patients. Late toxicity was recorded in 13 (32%) patients. No cases of G3 or G4 toxicity were recorded. Complete response was obtained in two (5%) patients, 26 (63%) showed a partial response, and two (5%) experience disease progression. At a mean follow-up of 9.9 months (range, 1.1-25.4), 17 patients had died from disease progression, one died from other causes, and 23 were alive. Median OS was 13.7 ± 1.5 months (95% CI: 10.7-16.7), OS at 12 and 18 months was 51.3 ± 9.5% and 35.1 ± 10.1%, respectively. Median PFS was 13.7 ± 2.3 months (95% CI: 9.1-18.2), and PFS at 12 and 18 months was 50.1 ± 9.9% and 38.9 ± 10.4%, respectively. Radical hypo-fractionated VMAT is a promising treatment for locally advanced NSCLC in the elderly. The use of hypo-fractionated radiotherapy for lung cancer in older patients can be considered a valuable approach, particularly for patients with poor performance status or refusing other treatment approaches. (orig.) [German] Durchfuehrbarkeit und Nebenwirkungen der radikalen

  15. Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy; Doses aux organes a risque cerebraux: optimisation par radiotherapie stereotaxique robotisee et atlas de segmentation automatique versus radiotherapie conformationnelle tridimensionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S. [Centre Antoine-Lacassagne, 06 - Nice (France); Malandain, G. [Institut National de Recherche en Informatique et en Automatique (INRIA), Sophia-Antipolis, 06 - Nice (France)

    2007-11-15

    The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

  16. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Luxemburgo Hospital, Mario Penna Institute, Belo Horizonte, MG (Brazil)

    2015-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  17. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Instituto Mario Penna, Minas Gerais, MG (Brazil). Hospital Luxemburgo

    2013-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  18. Exclusive radiotherapy and concurrent endocrine therapy for the management of elderly breast cancer patients: Case study and review of hypo-fractionated schemes; Hormonoradiotherapie exclusive dans la prise en charge du cancer du sein de la personne agee: cas clinique et revue de la litterature des schemas hypofractionnes

    Energy Technology Data Exchange (ETDEWEB)

    Auberdiac, P.; Cartier, L.; Malkoun, N.; Chauleur, C.; De Laroche, G.; Magne, N. [Departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard de Port-Royal, 75230 Paris cedex 5 (France); Melis, A.; Jacquin, J.P. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France)

    2011-12-15

    Normo-fractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using hypo-fractionated radiotherapy and endocrine therapy. We report a case of a patient treated with exclusive endocrine and radiotherapy and address the state of the art on hypo-fractionated schemes for the management of elderly breast cancer patients. While hypo-fractionated radiotherapy does not compromise the oncologic or cosmetic outcome, there is no prospective data that assesses the place of radiotherapy for the exclusive treatment of elderly patients. This strategy should be further assessed in clinical randomized trial. (authors)

  19. Conformal proton radiation therapy for pediatric low-grade astrocytomas

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    Hug, E.B. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Radiation Medicine; Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Pediatrics and Dept. of Pathology; Darthmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States). Section of Radiation Oncology; Muenter, M.W.; Archambeau, J.O.; DeVries, A.; Loredo, L.N.; Grove, R.I.; Slater, J.D. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Radiation Medicine; Liwnicz, B. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Pathology

    2002-01-01

    Background: To evaluate the safety and efficacy of proton radiation therapy (PRT) for intracranial low-grade astrocytomas, the authors analyzed the first 27 pediatric patients treated at Loma Linda University Medical Center (LLUMC). Patients and Method: Between September 1991 and August 1997, 27 patients (13 female, 14 male) underwent fractionated proton radiation therapy for progressive or recurrent low-grade astrocytoma. Age at time of treatment ranged from 2 to 18 years (mean: 8.7 years). Tumors were located centrally (diencephatic) in 15 patients, in the cerebral and cerebellar hemispheres in seven patients, and in the brainstem in five patients. 25/27 patients (92%) were treated for progressive, unresectable, or residual disease following subtotal resection. Tissue diagnosis was available in 23/27 patients (85%). Four patients with optic pathway tumors were treated without histologic confirmation. Target doses between 50.4 and 63.0 CGE (cobalt gray equivalent, mean: 55.2 CGE) were prescribed at 1.8 CGE per fraction, five treatments per week. Results: At a mean follow-up period of 3.3 years (0.6-6.8 years), 6/27 patients experienced local failure (all located within the irradiated field), and 4/27 patients had died. By anatomic site these data translated into rates of local control and survival of 87% (13/15 patients) and 93% (14/15 patients) for central tumors, 71% (5/7 patients) and 86% (6/7 patients) for hemispheric tumors, and 60% (3/5 patients) and 60% (3/5 patients) for tumors located in the brainstem. Proton radiation therapy was generally well tolerated. All children with local control maintained their performance status. One child with associated neurofibromatosis, Type 1, developed Moyamoya disease. All six patients with optic pathway tumors and useful vision maintained or improved their visual status. Conclusions: This report on pediatric low-grade astrocytomas confirms proton radiation therapy as a safe and efficacious 3-D conformal treatment

  20. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

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    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham [Andrew Love Cancer Centre, Geelong Hospital, Geelong, Victoria (Australia)

    2013-12-15

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

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

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    Manley, Stephen, E-mail: stephen.manley@ncahs.health.nsw.gov.au; Last, Andrew; Fu, Kenneth; Greenham, Stuart; Kovendy, Andrew; Shakespeare, Thomas P [North Coast Cancer Institute, Lismore, New South Wales (Australia)

    2015-06-15

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

  2. Three dimensional conformal radiation therapy may improve the therapeutic ratio of radiation therapy after pneumonectomy for lung cancer

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    Trouette, R.; Causse, N.; Elkhadri, M.; Caudry, M.; Maire, J.P.; Houlard, J.P.; Racaldini, L.; Demeaux, H.

    1995-12-01

    Three dimensional conformal radiation therapy would allow to decrease the normal tissue dose while maintaining the same target dose as standard treatment. To evaluate the feasibility of normal tissue dose reduction for ten patients with pneumonectomy for lung cancer, we determined the dose distribution to the normal tissue with 3-dimensional conformal radiation therapy (3-DCRT) and conventional treatment planning (CTP). Dose-volume histograms for target and normal tissue (lung, heart) were used for comparison of the different treatment planning. The mean percentages of lung and heart volumes which received 40 Gy with 3-DCRT were respectively 63% and 37% of the mean percentage of lung and volumes which received the same dose with CTP. These preliminary results suggest that conformal therapy may improve the therapeutic ratio by reducing risk to normal tissue.

  3. Hypofractionation does not increase radiation pneumonitis risk with modern conformal radiation delivery techniques

    DEFF Research Database (Denmark)

    Vogelius, Ivan R; Westerly, David C; Cannon, George M

    2010-01-01

    To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models.......To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models....

  4. A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sol Min; Song, Seong Chan; Hyun, Sung Eun; Park, Heung Deuk; Lee, Jaegi; Kim, Young Suk; Kim, Gwi Eon [Dept. of Radiation Oncology, Jeju National University Hospital, Jeju (Korea, Republic of)

    2016-06-15

    A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma For the lower extremity soft tissue sarcoma, volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy were evaluated to compare these three treatment planning technique. The mean doses to the planning target volume and the femur were calculated to evaluate target coverage and the risk of bone fracture during radiation therapy. Volumetric modulated arc therapy can reduce the dose to the femur without compromising target coverage and reduce the treatment time compared with intensity modulated radiation therapy.

  5. Performances study of UWB monopole antennas using half-elliptic radiator conformed on elliptical surface

    Energy Technology Data Exchange (ETDEWEB)

    Djidel, S.; Bouamar, M.; Khedrouche, D., E-mail: dkhedrouche@yahoo.com [LASS (Laboratoired’Analyse des Signaux et Systèmes), Department of Electronics, University of M’sila BP.166, Route Ichebilia, M’sila, 28000 Algeria (Algeria)

    2016-04-21

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  6. Three dimensional conformal radiation therapy in prostate adenocarcinoma: Survival and rectal toxicity

    Directory of Open Access Journals (Sweden)

    Kannan V

    2005-01-01

    Full Text Available Technological advances in radiation beam planning and linear accelerator based radiation delivery have led to the development of three dimensional conformal radiation therapy (3D-CRT. The 3D-CRT clinical treatment in our hospital was started in September 1998 and till December 2002, 51 patients with M0 stage prostate carcinoma were treated. Treatment method consisted of pelvis and leg immobilization, planning CT scan, marking of planning target volume and organs at risk and 3D beam plan using multileaf collimated beam shaping through beam′s eye view display. Network controlled 3D conformal radiation therapy was delivered with portal image verification. The median 3D-CRT dose was 72 Gy. Of the 51 patients, 35 were followed-up till December 2002 (minimum follow-up 2 years in whom 32 were disease free and 3 had progressive disease. Eleven patients died, 8 of progressive disease, one due to second malignancy and two of intercurrent illness. Five patients were lost for follow up during 0 - 29 months period, after 3D-CRT. The acute rectal reaction (RTOG criteria in 51 patients was grade 0 in 4, grade I in 31 and grade II in 16. None had greater than grade II rectal toxicity. The late rectal toxicity in 49 patients who had a minimum 6 months follow-up was grade 0 in 41, grade I in 3 and grade II in 5. Our experience suggests that a dose of 72 Gy by 3D-CRT can be safely delivered to the prostate and gastrointestinal tolerance during treatment and follow-up period was excellent.

  7. Radiation and scattering from cylindrically conformal printed antennas. Ph.D. Thesis Final Report

    Science.gov (United States)

    Kempel, Leo C.; Volakis, John L.

    1994-01-01

    Microstrip patch antennas offer considerable advantages in terms of weight, aerodynamic drag, cost, flexibility, and observables over more conventional protruding antennas. These flat patch antennas were first proposed over thirty years ago by Deschamps in the United States and Gutton and Baisinot in France. Such antennas have been analyzed and developed for planar as well as curved platforms. However, the methods used in these designs employ gross approximations, suffer from extreme computational burden, or require expensive physical experiments. The goal of this thesis is to develop accurate and efficient numerical modeling techniques which represent actual antenna structures mounted on curved surfaces with a high degree of fidelity. In this thesis, the finite element method is extended to cavity-backed conformal antenna arrays embedded in a circular, metallic, infinite cylinder. Both the boundary integral and absorbing boundary mesh closure conditions will be used for terminating the mesh. These two approaches will be contrasted and used to study the scattering and radiation behavior of several useful antenna configurations. An important feature of this study will be to examine the effect of curvature and cavity size on the scattering and radiation properties of wraparound conformal antenna arrays.

  8. Evaluation of flexible and rigid (class solution) radiation therapy conformal prostate planning protocols.

    Science.gov (United States)

    Coburn, Natalie; Beldham-Collins, Rachael; Westling, Jelene; Trovato, Jenny; Gebski, Val

    2012-01-01

    Protocols commonly implemented in radiotherapy work areas may be classified as being either rigid (class solution) or flexible. Because formal evaluation of these protocol types has not occurred within the literature, we evaluated the efficiency of a rigid compared with flexible prostate planning protocol by assessing a series of completed 3D conformal prostate plans. Twenty prostate cancer patients with an average age of 70 years (range, 52-77) and sizes comprising 8 small, 10 medium, and 2 large were planned on the Phillips Pinnacle treatment planning system 6 times by radiation therapists with 5 years of experience using a rigid and flexible protocol. Plans were critiqued using critical organ doses, confirmation numbers, and conformity index. Plans were then classified as being acceptable or not. Plans produced with the flexible protocol were 53% less likely to require modification (OR 0.47, 95% CI: 0.26, 0.84, p = 0.01). Planners with >5 years of experience were 78% more likely to produce plans requiring modification (OR 1.78, 95% CI: 1.12, 2.83, P = 0.02). Plans according to the flexible protocol took longer (112 min) compared with the time taken using a rigid protocol (68 min) (p plan is not reached, then flexibility should be given to improve the plan to meet the desired results. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  9. [Doses to organs at risk in conformational and stereotactic body radiation therapy: Liver].

    Science.gov (United States)

    Debbi, K; Janoray, G; Scher, N; Deutsch, É; Mornex, F

    2017-10-01

    The liver is an essential organ that ensures many vital functions such as metabolism of bilirubin, glucose, lipids, synthesis of coagulation factors, destruction of many toxins, etc. The hepatic parenchyma can be irradiated during the management of digestive tumors, right basithoracic, esophagus, abdomen in toto or TBI. In addition, radiotherapy of the hepatic area, which is mainly stereotactic, now occupies a central place in the management of primary or secondary hepatic tumors. Irradiation of the whole liver, or part of it, may be complicated by radiation-induced hepatitis. It is therefore necessary to respect strict dosimetric constraints both in stereotactic and in conformational irradiation in order to limit the undesired irradiation of the hepatic parenchyma which may vary according to the treatment techniques, the basic hepatic function or the lesion size. The liver is an organ with a parallel architecture, so the average tolerable dose in the whole liver should be considered rather than the maximum tolerable dose at one point. The purpose of this article is to propose a development of dose recommendations during conformation or stereotactic radiotherapy of the liver. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  10. Classically conformal radiative neutrino model with gauged B−L symmetry

    Directory of Open Access Journals (Sweden)

    Hiroshi Okada

    2016-09-01

    Full Text Available We propose a classically conformal model in a minimal radiative seesaw, in which we employ a gauged B−L symmetry in the standard model that is essential in order to work the Coleman–Weinberg mechanism well that induces the B−L symmetry breaking. As a result, nonzero Majorana mass term and electroweak symmetry breaking simultaneously occur. In this framework, we show a benchmark point to satisfy several theoretical and experimental constraints. Here theoretical constraints represent inert conditions and Coleman–Weinberg condition. Experimental bounds come from lepton flavor violations (especially μ→eγ, the current bound on the Z′ mass at the CERN Large Hadron Collider, and neutrino oscillations.

  11. Evaluation of flexible and rigid (class solution) radiation therapy conformal prostate planning protocols

    Energy Technology Data Exchange (ETDEWEB)

    Coburn, Natalie, E-mail: natalie.coburn@swahs.health.nsw.gov.au [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Beldham-Collins, Rachael [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Radiation Oncology Network, Westmead Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Westling, Jelene; Trovato, Jenny [Radiation Oncology Network, Nepean Cancer Care Centre, University of Sydney, Sydney, New South Wales (Australia); Gebski, Val [National Health and Medical Research Council Clinical Trials Centre, University of Sydney, Sydney, New South Wales (Australia)

    2012-04-01

    Protocols commonly implemented in radiotherapy work areas may be classified as being either rigid (class solution) or flexible. Because formal evaluation of these protocol types has not occurred within the literature, we evaluated the efficiency of a rigid compared with flexible prostate planning protocol by assessing a series of completed 3D conformal prostate plans. Twenty prostate cancer patients with an average age of 70 years (range, 52-77) and sizes comprising 8 small, 10 medium, and 2 large were planned on the Phillips Pinnacle treatment planning system 6 times by radiation therapists with <2 years, 2-5 years, and >5 years of experience using a rigid and flexible protocol. Plans were critiqued using critical organ doses, confirmation numbers, and conformity index. Plans were then classified as being acceptable or not. Plans produced with the flexible protocol were 53% less likely to require modification (OR 0.47, 95% CI: 0.26, 0.84, p = 0.01). Planners with >5 years of experience were 78% more likely to produce plans requiring modification (OR 1.78, 95% CI: 1.12, 2.83, P = 0.02). Plans according to the flexible protocol took longer (112 min) compared with the time taken using a rigid protocol (68 min) (p < 0.001). The results suggest that further studies are needed; however, we propose that all radiation therapy planners should start with the same limitations, and if an acceptable plan is not reached, then flexibility should be given to improve the plan to meet the desired results.

  12. Disease Control After Reduced Volume Conformal and Intensity Modulated Radiation Therapy for Childhood Craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Kun, Larry E.; Hua, Chia-Ho [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Wu, Shengjie; Xiong, Xiaoping [St Jude Children' s Research Hospital, Biostatistics, Memphis, Tennessee (United States); Sanford, Robert A.; Boop, Frederick A. [Semmes Murphey Neurologic and Spine Institute, Neurosurgery, Memphis, Tennessee (United States)

    2013-03-15

    Purpose: To estimate the rate of disease control after conformal radiation therapy using reduced clinical target volume (CTV) margins and to determine factors that predict for tumor progression. Methods and Materials: Eighty-eight children (median age, 8.5 years; range, 3.2-17.6 years) received conformal or intensity modulated radiation therapy between 1998 and 2009. The study group included those prospectively treated from 1998 to 2003, using a 10-mm CTV, defined as the margin surrounding the solid and cystic tumor targeted to receive the prescription dose of 54 Gy. The CTV margin was subsequently reduced after 2003, yielding 2 groups of patients: those treated with a CTV margin greater than 5 mm (n=26) and those treated with a CTV margin less than or equal to 5 mm (n=62). Disease progression was estimated on the basis of additional variables including sex, race, extent of resection, tumor interventions, target volume margins, and frequency of weekly surveillance magnetic resonance (MR) imaging during radiation therapy. Median follow-up was 5 years. Results: There was no difference between progression-free survival rates based on CTV margins (>5 mm vs ≤5 mm) at 5 years (88.1% ± 6.3% vs 96.2% ± 4.4% [P=.6386]). There were no differences based on planning target volume (PTV) margins (or combined CTV plus PTV margins). The PTV was systematically reduced from 5 to 3 mm during the time period of the study. Factors predictive of superior progression-free survival included Caucasian race (P=.0175), no requirement for cerebrospinal fluid shunting (P=.0066), and number of surveillance imaging studies during treatment (P=.0216). Patients whose treatment protocol included a higher number of weekly surveillance MR imaging evaluations had a lower rate of tumor progression. Conclusions: These results suggest that targeted volume reductions for radiation therapy using smaller margins are feasible and safe but require careful monitoring. We are currently investigating

  13. Emotional and Behavioral Functioning After Conformal Radiation Therapy for Pediatric Ependymoma

    Energy Technology Data Exchange (ETDEWEB)

    Willard, Victoria W.; Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Boop, Frederick A. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Department of Neurosurgery, Semmes-Murphey Neurologic and Spine Institute, Memphis, Tennessee (United States); Wu, Shengjie [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2014-03-15

    Purpose: The standard of care for pediatric patients with ependymoma involves postoperative radiation therapy. Prior research suggests that conformal radiation therapy (CRT) is associated with relative sparing of cognitive and academic functioning, but little is known about the effect of CRT on emotional and behavioral functioning. Methods and Materials: A total of 113 patients with pediatric ependymoma underwent CRT using photons as part of their enrollment on an institutional trial. Patients completed annual evaluations of neurocognitive functioning during the first 5 years after CRT. Emotional and behavioral functioning was assessed via the Child Behavior Checklist. Results: Before CRT, emotional and behavioral functioning were commensurate with those of the normative population and within normal limits. After 5 years, means remained within normal limits but were significantly below the normative mean. Linear mixed models revealed a significant increase in attention problems over time. These problems were associated with age at diagnosis/CRT, tumor location, and extent of resection. A higher-than-expected incidence of school problems was present at all assessment points after baseline. Conclusions: The use of photon CRT for ependymoma is associated with relatively stable emotional and behavioral functioning during the first 5 years after treatment. The exception is an increase in attention problems. Results suggest that intervening earlier in the survivorship period—during the first year posttreatment—may be beneficial.

  14. Conformal image-guided microbeam radiation therapy at the ESRF biomedical beamline ID17.

    Science.gov (United States)

    Donzelli, Mattia; Bräuer-Krisch, Elke; Nemoz, Christian; Brochard, Thierry; Oelfke, Uwe

    2016-06-01

    Upcoming veterinary trials in microbeam radiation therapy (MRT) demand for more advanced irradiation techniques than in preclinical research with small animals. The treatment of deep-seated tumors in cats and dogs with MRT requires sophisticated irradiation geometries from multiple ports, which impose further efforts to spare the normal tissue surrounding the target. This work presents the development and benchmarking of a precise patient alignment protocol for MRT at the biomedical beamline ID17 of the European Synchrotron Radiation Facility (ESRF). The positioning of the patient prior to irradiation is verified by taking x-ray projection images from different angles. Using four external fiducial markers of 1.7  mm diameter and computed tomography-based treatment planning, a target alignment error of less than 2  mm can be achieved with an angular deviation of less than 2(∘). Minor improvements on the protocol and the use of smaller markers indicate that even a precision better than 1  mm is technically feasible. Detailed investigations concerning the imaging dose lead to the conclusion that doses for skull radiographs lie in the same range as dose reference levels for human head radiographs. A currently used online dose monitor for MRT has been proven to give reliable results for the imaging beam. The ESRF biomedical beamline ID17 is technically ready to apply conformal image-guided MRT from multiple ports to large animals during future veterinary trials.

  15. Characterisation of Conformational and Ligand Binding Properties of Membrane Proteins Using Synchrotron Radiation Circular Dichroism (SRCD).

    Science.gov (United States)

    Hussain, Rohanah; Siligardi, Giuliano

    Membrane proteins are notoriously difficult to crystallise for use in X-ray crystallographic structural determination, or too complex for NMR structural studies. Circular dichroism (CD) is a fast and relatively easy spectroscopic technique to study protein conformational behaviour in solution. The advantage of synchrotron radiation circular dichroism (SRCD) measured with synchrotron beamlines compared to the CD from benchtop instruments is the extended spectral far-UV region that increases the accuracy of secondary structure estimations, in particular under high ionic strength conditions. Membrane proteins are often available in small quantities, and for this SRCD measured at the Diamond B23 beamline has successfully facilitated molecular recognition studies. This was done by probing the local tertiary structure of aromatic amino acid residues upon addition of chiral or non-chiral ligands using long pathlength cells (1-5 cm) of small volume capacity (70 μl-350 μl). In this chapter we describe the use of SRCD to qualitatively and quantitatively screen ligand binding interactions (exemplified by Sbma, Ace1 and FsrC proteins); to distinguish between functionally similar drugs that exhibit different mechanisms of action towards membrane proteins (exemplified by FsrC); and to identify suitable detergent conditions to observe membrane protein-ligand interactions using stabilised proteins (exemplified by inositol transporters) as well as the stability of membrane proteins (exemplified by GalP, Ace1). The importance of the in solution characterisation of the conformational behaviour and ligand binding properties of proteins in both far- andnear-UV regions and the use of high-throughput CD (HT-CD) using 96- and 384-well multiplates to study the folding effects in various protein crystallisation buffers are also discussed.

  16. Target volume delineation and field setup. A practical guide for conformal and intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nancy Y. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States). Radiation Oncology; Lu, Jiade J. (eds.) [National Univ. Health System, Singapore (Singapore). Dept. of Radiation Oncology; National Univ. of Singapore (Singapore). Dept. of Medicine

    2013-03-01

    Practical handbook on selection and delineation of tumor volumes and fields for conformal radiation therapy, including IMRT. Helpful format facilitating use on a step-by-step basis in daily practice. Designed to ensure accurate coverage of commonly encountered tumors along their routes of spread. This handbook is designed to enable radiation oncologists to appropriately and confidently delineate tumor volumes/fields for conformal radiation therapy, including intensity-modulated radiation therapy (IMRT), in patients with commonly encountered cancers. The orientation of this handbook is entirely practical, in that the focus is on the illustration of clinical target volume (CTV) delineation for each major malignancy. Each chapter provides guidelines and concise knowledge on CTV selection for a particular disease, explains how the anatomy of lymphatic drainage shapes the selection of the target volume, and presents detailed illustrations of volumes, slice by slice, on planning CT images. While the emphasis is on target volume delineation for three-dimensional conformal therapy and IMRT, information is also provided on conventional radiation therapy field setup and planning for certain malignancies for which IMRT is not currently suitable.

  17. Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

    NARCIS (Netherlands)

    Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

    2014-01-01

    AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

  18. Learning and Memory Following Conformal Radiation Therapy for Pediatric Craniopharyngioma and Low-Grade Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Di Pinto, Marcos [Department of Pediatric Psychology, Children' s Hospital of Orange County, Orange, California (United States); Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Li, Chenghong [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2012-11-01

    Purpose: The primary objective of this study was to examine whether children with low-grade glioma (LGG) or craniopharyngioma had impaired learning and memory after conformal radiation therapy (CRT). A secondary objective was to determine whether children who received chemotherapy before CRT, a treatment often used to delay radiation therapy in younger children with LGG, received any protective benefit with respect to learning. Methods and Materials: Learning and memory in 57 children with LGG and 44 children with craniopharyngioma were assessed with the California Verbal Learning Test-Children's Version and the Visual-Auditory Learning tests. Learning measures were administered before CRT, 6 months later, and then yearly for a total of 5 years. Results: No decline in learning scores after CRT was observed when patients were grouped by diagnosis. For children with LGG, chemotherapy before CRT did not provide a protective effect on learning. Multiple regression analyses, which accounted for age and tumor volume and location, found that children treated with chemotherapy before CRT were at greater risk of decline on learning measures than those treated with CRT alone. Variables predictive of learning and memory decline included hydrocephalus, shunt insertion, younger age at time of treatment, female gender, and pre-CRT chemotherapy. Conclusions: This study did not reveal any impairment or decline in learning after CRT in overall aggregate learning scores. However, several important variables were found to have a significant effect on neurocognitive outcome. Specifically, chemotherapy before CRT was predictive of worse outcome on verbal learning in LGG patients. In addition, hydrocephalus and shunt insertion in craniopharyngioma were found to be predictive of worse neurocognitive outcome, suggesting a more aggressive natural history for those patients.

  19. Investigating verbal and visual auditory learning after conformal radiation therapy for childhood ependymoma.

    Science.gov (United States)

    Di Pinto, Marcos; Conklin, Heather M; Li, Chenghong; Xiong, Xiaoping; Merchant, Thomas E

    2010-07-15

    The primary objective of this study was to determine whether children with localized ependymoma experience a decline in verbal or visual-auditory learning after conformal radiation therapy (CRT). The secondary objective was to investigate the impact of age and select clinical factors on learning before and after treatment. Learning in a sample of 71 patients with localized ependymoma was assessed with the California Verbal Learning Test (CVLT-C) and the Visual-Auditory Learning Test (VAL). Learning measures were administered before CRT, at 6 months, and then yearly for a total of 5 years. There was no significant decline on measures of verbal or visual-auditory learning after CRT; however, younger age, more surgeries, and cerebrospinal fluid shunting did predict lower scores at baseline. There were significant longitudinal effects (improved learning scores after treatment) among older children on the CVLT-C and children that did not receive pre-CRT chemotherapy on the VAL. There was no evidence of global decline in learning after CRT in children with localized ependymoma. Several important implications from the findings include the following: (1) identification of and differentiation among variables with transient vs. long-term effects on learning, (2) demonstration that children treated with chemotherapy before CRT had greater risk of adverse visual-auditory learning performance, and (3) establishment of baseline and serial assessment as critical in ascertaining necessary sensitivity and specificity for the detection of modest effects. Copyright 2010 Elsevier Inc. All rights reserved.

  20. A novel modified dynamic conformal arc technique for treatment of peripheral lung tumors using stereotactic body radiation therapy.

    Science.gov (United States)

    Ross, Christopher C; Kim, John J; Chen, Zhe J; Grew, David J; Chang, Bryan W; Decker, Roy H

    2011-01-01

    To describe and compare a novel, modified dynamic conformal arc (MDCA) technique for lung stereotactic body radiation therapy with the standard noncoplanar beam (NCB) technique based on stereotactic body radiation therapy (SBRT) coverage, dose conformality, normal tissue constraints, and treatment time. Twenty consecutive medically inoperable patients with early stage, peripheral, non-small cell lung cancer treated with SBRT using an NCB technique were re-planned with a novel MDCA technique. Treatment plans were compared based on Radiation Therapy Oncology Group (RTOG) 0236 criteria for planning treatment volume (PTV) coverage and normal tissue dose constraints, as well as high- and moderate-dose conformality. Treatment times necessary to deliver the NCB plans were compared with the times of a separate group of 12 consecutive patients treated with the MDCA technique at our institution. The MDCA technique resulted in improved coverage of the cranial and caudal regions of the PTV and generated plans that were significantly more conformal by all high-dose criteria proposed by the RTOG protocol. In terms of moderate-dose criteria, MDCA plans had a significantly lower maximum dose (2 cm from the PTV), whereas the ratio of the 50% dose volume to the volume of the PTV was equivalent between the 2 techniques. All normal tissue dose constraints proposed in the RTOG 0236 protocol were met by each plan, although the median lung V20 and mean lung dose were slightly higher in the MDCA plans, whereas the chest wall dose was slightly lower. A 42% reduction in treatment time was observed when patients treated with the NCB technique were compared with a separate cohort of 12 patients treated with the MDCA technique (P NCB technique. Copyright © 2011 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  1. Longitudinal analysis of quality of life in patients receiving conformal radiation therapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans; Thamm, Reinhard; Scholz, Christian; Heinrich, Christine; Prause, Nina; Kerndl, Simone; Molls, Michael; Zimmermann, Frank B. [Dept. of Radiotherapy and Radiooncology, Technische Univ. Muenchen (Germany); Keller, Monika [Psychooncology Section, Dept. of Psychosomatic and General Clinical Medicine, Univ. Hospital, Heidelberg (Germany); Busch, Raymonde [Inst. of Medical Statistics and Epidemiology, Technische Univ. Muenchen (Germany)

    2010-01-15

    Purpose: To prospectively assess quality of life (QoL) in patients receiving conformal radiation therapy (CRT) for prostate cancer. Patients and Methods: 78 men with definitive CRT for prostate cancer were entered into the study. Patients were assessed before CRT, at 40 and 60 Gy, and 2, 12 and 24 months after the end of treatment. QoL was assessed using the EORTC Quality of Life Questionnaire C30 and the prostate module PR25. Changes in mean QoL scores with time of {>=} 10 points were considered clinically relevant. Results: Global QoL did not change statistically significant during CRT and was slightly above baseline levels during follow-up. CRT had a statistically significant negative short-term impact on role functioning, fatigue, and PR25 urinary symptoms. The scores recovered within 2 months to 1 year after CRT. Emotional functioning and social functioning scores slightly increased during and after CRT. Role functioning decreased by > 10 points at 60 Gy and urinary symptoms decreased by > 10 points at 40 and 60 Gy. All other differences were < 10 points. A high number of concomitant diseases and having no children were negative pretreatment predictors for long-term global QoL. Conclusion: Definitive CRT for prostate cancer does not compromise global QoL during therapy and up to 2 years after treatment. It has a limited negative effect on role functioning, urinary symptoms and, to a lesser extent, on fatigue with restitution within 2 months to 1 year after treatment. (orig.)

  2. Conformal radiation therapy with or without intensity modulation in the treatment of localized prostate cancer; La radiotherapie de conformation avec et sans modulation d'intensite dans le traitement du cancer localise de la prostate

    Energy Technology Data Exchange (ETDEWEB)

    Maingon, P.; Truc, G.; Bosset, M.; Peignaux, K.; Ammor, A. [Centre Georges-Francois-Leclerc, Dept. Radiotherapie, 21 - Dijon (France); Bolla, M. [Centre Hospitalier Universitaire de Grenoble, Service de Radiotherapie-Oncologie, 38 - Grenoble (France)

    2005-11-15

    Conformal radiation therapy has now to be considered as a standard treatment of localized prostatic adenocarcinomas. Using conformational methods and intensity modulated radiation therapy requires a rigorous approach for their implementation in routine, focused on the reproducibility of the treatment, target volume definitions, dosimetry, quality control, setup positioning. In order to offer to the largest number of patients high-dose treatment, the clinicians must integrate as prognostic factors accurate definition of microscopic extension as well as the tolerance threshold of critical organs. High-dose delivery is expected to be most efficient in intermediary risks and locally advanced diseases. Intensity modulated radiation therapy is specifically dedicated to dose escalation. Perfect knowledge of classical constraints of conformal radiation therapy is required. Using such an approach in routine needs a learning curve including the physicists and a specific quality assurance program. (author)

  3. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2000-08-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, ``conformal infinity'' is related with almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved out of physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation and how it lends itself very naturally to solve radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  4. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2004-01-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, 'conformal infinity' is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  5. Clinical applications of image guided-intensity modulated radiation therapy (IG-IMRT) for conformal avoidance of normal tissue

    Science.gov (United States)

    Gutierrez, Alonso Navar

    2007-12-01

    Recent improvements in imaging technology and radiation delivery have led to the development of advanced treatment techniques in radiotherapy which have opened the door for novel therapeutic approaches to improve the efficacy of radiation cancer treatments. Among these advances is image-guided, intensity modulated radiation therapy (IG-IMRT), in which imaging is incorporated to aid in inter-/intra-fractional target localization and to ensure accurate delivery of precise and highly conformal dose distributions. In principle, clinical implementation of IG-IMRT should improve normal tissue sparing and permit effective biological dose escalation thus widening the radiation therapeutic window and lead to increases in survival through improved local control of primary neoplastic diseases. Details of the development of three clinical applications made possible solely with IG-IMRT radiation delivery techniques are presented: (1) Laparoscopically implanted tissue expander radiotherapy (LITE-RT) has been developed to enhance conformal avoidance of normal tissue during the treatment of intra-abdominopelvic cancers. LITE-RT functions by geometrically displacing surrounding normal tissue and isolating the target volume through the interfractional inflation of a custom-shaped tissue expander throughout the course of treatment. (2) The unique delivery geometry of helical tomotherapy, a novel form of IG-IMRT, enables the delivery of composite treatment plan m which whole brain radiotherapy (WBRT) with hippocampal avoidance, hypothesized to reduce the risk of memory function decline and improve the patient's quality of life, and simultaneously integrated boost to multiple brain metastases to improve intracranial tumor control is achieved. (3) Escalation of biological dose to targets through integrated, selective subvolume boosts have been shown to efficiently increase tumor dose without significantly increasing normal tissue dose. Helical tomotherapy was used to investigate the

  6. Potential for improved intelligence quotient using volumetric modulated arc therapy compared with conventional 3-dimensional conformal radiation for whole-ventricular radiation in children.

    Science.gov (United States)

    Qi, X Sharon; Stinauer, Michelle; Rogers, Brion; Madden, Jennifer R; Wilkening, Greta N; Liu, Arthur K

    2012-12-01

    To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Potential for Improved Intelligence Quotient Using Volumetric Modulated Arc Therapy Compared With Conventional 3-Dimensional Conformal Radiation for Whole-Ventricular Radiation in Children

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States); Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Stinauer, Michelle; Rogers, Brion [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Madden, Jennifer R. [Department of Neuro-Oncology, The Children' s Hospital, Aurora, Colorado (United States); Wilkening, Greta N. [Department of Pediatrics, The Children' s Hospital, Aurora, Colorado (United States); Liu, Arthur K. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

    2012-12-01

    Purpose: To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Method and Materials: Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Results: Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. Conclusion: For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children.

  8. A novel conformity index for intensity modulated radiation therapy plan evaluation.

    Science.gov (United States)

    Cheung, Fion W K; Law, Maria Y Y

    2012-09-01

    Intensity modulated radiation therapy (IMRT) has gained popularity in the treatment of cancers. Manual evaluation of IMRT plans for head-and-neck cancers has been especially challenging necessitating efficient and objective assessment tools. In this work, the authors address this issue by developing a personalized conformity index (CI) for comparison of IMRT plans for head-and-neck cancers and evaluating its plan quality discerning power in comparison with other widely used CIs. A two-dimensional CI with dose and distance incorporated (CI(DD)) was developed using the MATLAB program language, to quantify the planning target volume (PTV) coverage. Valuable information contained in the digital imaging and communication in medicine (DICOM) RT objects were harvested for computation of each of the CI(DD) components. Apart from the dose penalty factor, a distance-based exponential function was employed by varying the penalty weight associated with the location of cold spots within the PTV. With the goal of deriving a customized penalty factor, the distances between individual pixel and its nearest PTV boundary was found. Using the exponential function, the impact of distance penalty was substantially larger for cold spots closer to the PTV centroid but petered out quickly wherever they were situated in the vicinity of PTV border. In order to evaluate the CI(DD) scoring system, three CT image data sets of nasopharyngeal carcinoma (NPC) patients were collected. Ten IMRT plans with degrading qualities were generated from each dataset and were ranked based on CI(DD) and other existing indices. The coefficient of variance was calculated for each dataset to compare the degree of variation. The CI(DD) scoring system that considered spatial importance of each voxel within the PTV was successfully developed. The results demonstrated that the CI(DD) including four discrete factors could provide accurate rankings of plan quality by examining the relative importance of each cold spot

  9. Radiation-Induced Liver Injury in Three-Dimensional Conformal Radiation Therapy (3D-CRT) for Postoperative or Locoregional Recurrent Gastric Cancer: Risk Factors and Dose Limitations.

    Science.gov (United States)

    Li, Guichao; Wang, Jiazhou; Hu, Weigang; Zhang, Zhen

    2015-01-01

    This study examined the status of radiation-induced liver injury in adjuvant or palliative gastric cancer radiation therapy (RT), identified risk factors of radiation-induced liver injury in gastric cancer RT, analysed the dose-volume effects of liver injury, and developed a liver dose limitation reference for gastric cancer RT. Data for 56 post-operative gastric cancer patients and 6 locoregional recurrent gastric cancer patients treated with three-dimensional conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) from Sep 2007 to Sep 2009 were analysed. Forty patients (65%) were administered concurrent chemotherapy. Pre- and post-radiation chemotherapy were given to 61 patients and 43 patients, respectively. The radiation dose was 45-50.4 Gy in 25-28 fractions. Clinical parameters, including gender, age, hepatic B virus status, concurrent chemotherapy, and the total number of chemotherapy cycles, were included in the analysis. Univariate analyses with a non-parametric rank test (Mann-Whitney test) and logistic regression test and a multivariate analysis using a logistic regression test were completed. We also analysed the correlation between RT and the changes in serum chemistry parameters [including total bilirubin, (TB), direct bilirubin (D-TB), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and serum albumin (ALB)] after RT. The Child-Pugh grade progressed from grade A to grade B after radiotherapy in 10 patients. A total of 16 cases of classic radiation-induced liver disease (RILD) were observed, and 2 patients had both Child-Pugh grade progression and classic RILD. No cases of non-classic radiation liver injury occurred in the study population. Among the tested clinical parameters, the total number of chemotherapy cycles correlated with liver function injury. V35 and ALP levels were significant predictive factors for radiation liver injury. In 3D-CRT for gastric cancer patients

  10. A 5-Year Investigation of Children's Adaptive Functioning Following Conformal Radiation Therapy for Localized Ependymoma

    Energy Technology Data Exchange (ETDEWEB)

    Netson, Kelli L.; Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu Shengjie; Xiong Xiaoping [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2012-09-01

    Purpose: Conformal and intensity modulated radiation therapies have the potential to preserve cognitive outcomes in children with ependymoma; however, functional behavior remains uninvestigated. This longitudinal investigation prospectively examined intelligence quotient (IQ) and adaptive functioning during the first 5 years after irradiation in children diagnosed with ependymoma. Methods and Materials: The study cohort consisted of 123 children with intracranial ependymoma. Mean age at irradiation was 4.60 years (95% confidence interval [CI], 3.85-5.35). Serial neurocognitive evaluations, including an age-appropriate IQ measure and the Vineland Adaptive Behavior Scales (VABS), were completed before irradiation, 6 months after treatment, and annually for 5 years. A total of 579 neurocognitive evaluations were included in these analyses. Results: Baseline IQ and VABS were below normative means (P<.05), although within the average range. Linear mixed models revealed stable IQ and VABS across the follow-up period, except for the VABS Communication Index, which declined significantly (P=.015). Annual change in IQ (-.04 points) did not correlate with annual change in VABS (-.90 to +.44 points). Clinical factors associated with poorer baseline performance (P<.05) included preirradiation chemotherapy, cerebrospinal fluid shunt placement, number and extent of surgical resections, and younger age at treatment. No clinical factors significantly affected the rate of change in scores. Conclusions: Conformal and intensity modulated radiation therapies provided relative sparing of functional outcomes including IQ and adaptive behaviors, even in very young children. Communication skills remained vulnerable and should be the target of preventive and rehabilitative interventions.

  11. Studying the efficacy of escalated dose conformal radiation therapy in prostate carcinoma – Pakistan experience

    Directory of Open Access Journals (Sweden)

    Asad Zamir

    2017-11-01

    Conclusion: Our data were comparable to international studies of dose escalation using 3D and beneficial as compared to conventional radiation therapy delivered by 2D in terms of biochemical failure rate and treatment related toxicity.

  12. NIR Laser Radiation Induced Conformational Changes and Tunneling Lifetimes of High-Energy Conformers of Amino Acids in Low-Temperature Matrices

    Science.gov (United States)

    Bazso, Gabor; Najbauer, Eszter E.; Magyarfalvi, Gabor; Tarczay, Gyorgy

    2013-06-01

    We review our recent results on combined matrix isolation FT-IR and NIR laser irradiation studies on glycine alanine, and cysteine. The OH and the NH stretching overtones of the low-energy conformers of these amino acids deposited in Ar, Kr, Xe, and N_{2} matrices were irradiated. At the expense of the irradiated conformer, other conformers were enriched and new, high-energy, formerly unobserved conformers were formed in the matrices. This enabled the separation and unambiguous assignment of the vibrational transitions of the different conformers. The main conversion paths and their efficiencies are described qualitatively showing that there are significant differences in different matrices. It was shown that the high-energy conformer decays in the matrix by H-atom tunneling. The lifetimes of the high-energy conformers in different matrices were measured. Based on our results we conclude that some theoretically predicted low-energy conformers of amino acids are likely even absent in low-energy matrices due to fast H-atom tunneling. G. Bazso, G. Magyarfalvi, G. Tarczay J. Mol. Struct. 1025 (Light-Induced Processes in Cryogenic Matrices Special Issue) 33-42 (2012). G. Bazso, G. Magyarfalvi, G. Tarczay J. Phys. Chem. A 116 (43) 10539-10547 (2012). G. Bazso, E. E. Najbauer, G. Magyarfalvi, G. Tarczay J. Phys. Chem. A in press, DOI: 10.1021/jp400196b. E. E. Najbauer, G. Bazso, G. Magyarfalvi, G. Tarczay in preparation.

  13. Preliminary study of the 270 Bloom Fricke xylenol gel phantom performance for 3D conformal radiotherapy using multiple radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (DIRF/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes; Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagens; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Servico de Radioterapia

    2011-07-01

    The complex cancer treatment techniques require rigorous quality control (QC). The Fricke xylenol gel (FXG) dosimeter has been studied to be applied as a three-dimensional (3D) dosimeter since it is possible to produce 3D FXG phantoms of various shapes and sizes. In this preliminary study, the performance of the FXG spherical phantom developed at IPEN, prepared using 270 Bloom gelatin from porcine skin made in Brazil, was evaluated using magnetic resonance imaging technique, aiming to use this phantom to 3D conformal radiotherapy (3DCRT) with multiple radiation fields and clinical photon beams. The obtained results indicate that for all magnetic resonance images of the FXG phantom irradiated with 6 MV clinical photon beam can be observed clearly the target volume and, in the case of coronal image, can also be observed the radiation beam projection and the overlap of different radiation fields used. The Fricke xylenol gel phantom presented satisfactory results for 3DCRT and clinical photon beams in this preliminary study. These results encourage the additional tests using complex treatment techniques and indicate the viability of applying the phantom studied to routine quality control measurements and in 3DCRT and intensity modulated radiotherapy treatment planning. (author)

  14. Digestive toxicities after palliative three-dimensional conformal radiation therapy (3D-CRT) for cervico-thoracic spinal metastases.

    Science.gov (United States)

    Peyraga, Guillaume; Caron, Delphine; Lizee, Thibaut; Metayer, Yann; Septans, Anne-Lise; Pointreau, Yoann; Denis, Fabrice; Ganem, Gerard; Lafond, Cedrik; Roche, Sophie; Dupuis, Olivier

    2017-12-23

    The palliative treatment for cervico-thoracic spinal metastases is based on a three-dimensional conformal radiation therapy (3D-CRT). Digestive toxicities are common and cause a clinical impact frequently underestimated in patients. We performed a retrospective study of digestive side effects occurring after palliative 3D-CRT for cervico-thoracic spinal metastases. All patients receiving palliative 3D-CRT at Jean Bernard Center from January 2013 to December 2014 for spinal metastases between the 5th cervical vertebra (C5) and the 12th thoracic vertebra (T12) were eligible. Three-dimensional conformal RT was delivered by a linear accelerator (CLINAC, Varian). Premedication to prevent digestive toxicities was not used. Adverse events ("esophagitis" and "nausea and/or vomiting") were evaluated according to the NCI-CTCae (version 4). From January 2013 to December 2014, 128 patients met the study criteria. The median age was 68.6 years [31.8; 88.6]. Most patients (84.4%) received 30 Gy in 10 fractions. The median overall time of treatment was 13 days [3-33]. Forty patients (31.3%) suffered from grade ≥ 2 of "esophagitis" (35 grade 2 (27.4%) and 5 grade 3 (3.9%)). Eight patients (6.3%) suffered from grade ≥ 2 of "nausea and/or vomiting" (6 grade 2 (4.7%), 1 grade 3 (0.8%), and 1 grade 4 (0.8%)). The high incidence of moderate to severe digestive toxicities after palliative 3D-CRT for cervico-thoracic spinal metastases led to consider static or dynamic intensity-modulated radiation therapy (IMRT) to reduce the dose to organ at risk (the esophagus and stomach). Dosimetric studies and implementation in the clinic should be the next steps.

  15. The Rapid Response Radiation Survey (R3S) Mission Using the HiSat Conformal Satellite Architecture

    Science.gov (United States)

    Miller, Nathanael A.; Norman, Ryan B.; Soto, Hector L.; Stewart, Victor A.; Jones, Mark L.; Kowalski, Matthew C.; Ben Shabat, Adam; Gough, Kerry M.; Stavely, Rebecca L.; Shim, Alex C.; hide

    2015-01-01

    The Rapid Response Radiation Survey (R3S) experiment, designed as a quick turnaround mission to make radiation measurements in Low Earth Orbit (LEO), will fly as a hosted payload in partnership with NovaWurks using their Hyper-integrated Satlet (HISat) architecture. The need for the mission arises as the Nowcast of Atmospheric Ionization Radiation for Aviation Safety (NAIRAS) model moves from a research effort into an operational radiation assessment tool. Currently, airline professionals are the second largest demographic of radiation workers and to date their radiation exposure is undocumented in the USA. The NAIRAS model seeks to fill this information gap. The data collected by R3S, in addition to the complementary data from a NASA Langley Research Center (LaRC) atmospheric balloon mission entitled Radiation Dosimetry Experiment (RaD-X), will validate exposure prediction capabilities of NAIRAS. The R3S mission collects total dose and radiation spectrum measurements using a Teledyne µDosimeter and a Liulin-6SA2 LED spectrometer. These two radiation sensors provide a cross correlated radiometric measurement in combination with the Honeywell HMR2300 Smart Digital Magnetometer. The magnetometer assesses the Earth's magnetic field in the LEO environment and allows radiation dose to be mapped as a function of the Earth's magnetic shielding. R3S is also unique in that the radiation sensors will be exposed on the outer surface of the spacecraft, possibly making this the first measurements of the LEO radiation environment with bare sensors. Viability of R3S as an extremely fast turnaround mission is due, in part, to the nature of the robust, well-defined interfaces of the conformal satellite HiSat Architecture. The HiSat architecture, which was developed with the support of the Defense Advanced Research Projects Agency's (DARPA's) Phoenix Program, enabled the R3S system to advance from the first concept to delivery of preliminary design review (PDR) level documents in

  16. Late Side Effects After Image Guided Intensity Modulated Radiation Therapy Compared to 3D-Conformal Radiation Therapy for Prostate Cancer: Results From 2 Prospective Cohorts

    Energy Technology Data Exchange (ETDEWEB)

    Wortel, Ruud C.; Incrocci, Luca [Department of Radiation Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Pos, Floris J.; Heide, Uulke A. van der; Lebesque, Joos V. [Department of Radiation Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Aluwini, Shafak [Department of Radiation Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Witte, Marnix G. [Department of Radiation Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Heemsbergen, Wilma D., E-mail: w.heemsbergen@nki.nl [Department of Radiation Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

    2016-06-01

    Purpose: Technical developments in the field of external beam radiation therapy (RT) enabled the clinical introduction of image guided intensity modulated radiation therapy (IG-IMRT), which improved target conformity and allowed reduction of safety margins. Whether this had an impact on late toxicity levels compared to previously applied three-dimensional conformal radiation therapy (3D-CRT) is currently unknown. We analyzed late side effects after treatment with IG-IMRT or 3D-CRT, evaluating 2 prospective cohorts of men treated for localized prostate cancer to investigate the hypothesized reductions in toxicity. Methods and Materials: Patients treated with 3D-CRT (n=189) or IG-IMRT (n=242) to 78 Gy in 39 fractions were recruited from 2 Dutch randomized trials with identical toxicity scoring protocols. Late toxicity (>90 days after treatment) was derived from self-assessment questionnaires and case report forms, according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG-EORTC) scoring criteria. Grade ≥2 endpoints included gastrointestinal (GI) rectal bleeding, increased stool frequency, discomfort, rectal incontinence, proctitis, and genitourinary (GU) obstruction, increased urinary frequency, nocturia, urinary incontinence, and dysuria. The Cox proportional hazards regression model was used to compare grade ≥2 toxicities between both techniques, adjusting for other modifying factors. Results: The 5-year cumulative incidence of grade ≥2 GI toxicity was 24.9% for IG-IMRT and 37.6% following 3D-CRT (adjusted hazard ratio [HR]: 0.59, P=.005), with significant reductions in proctitis (HR: 0.37, P=.047) and increased stool frequency (HR: 0.23, P<.001). GU grade ≥2 toxicity levels at 5 years were comparable with 46.2% and 36.4% following IG-IMRT and 3D-CRT, respectively (adjusted HR: 1.19, P=.33). Other strong predictors (P<.01) of grade ≥2 late toxicity were baseline complaints, acute toxicity, and age

  17. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Preoperative Treatment of Extremity Soft Tissue Sarcomas

    Energy Technology Data Exchange (ETDEWEB)

    Richard, Patrick, E-mail: patrjr@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Phillips, Mark; Smith, Wade [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Davidson, Darin [Department of Orthopedic Surgery, University of Washington, Seattle, Washington (United States); Kim, Edward; Kane, Gabrielle [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States)

    2016-07-01

    Purpose: Create a cost-effectiveness model comparing preoperative intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3DCRT) for extremity soft tissue sarcomas. Methods and Materials: Input parameters included 5-year local recurrence rates, rates of acute wound adverse events, and chronic toxicities (edema, fracture, joint stiffness, and fibrosis). Health-state utilities were used to calculate quality-adjusted life years (QALYs). Overall treatment costs per QALY or incremental cost-effectiveness ratio (ICER) were calculated. Roll-back analysis was performed using average costs and utilities to determine the baseline preferred radiation technique. One-way, 2-way, and probabilistic sensitivity analyses (PSA) were performed for input parameters with the largest impact on the ICER. Results: Overall treatment costs were $17,515.58 for 3DCRT compared with $22,920.51 for IMRT. The effectiveness was higher for IMRT (3.68 QALYs) than for 3DCRT (3.35 QALYs). The baseline ICER for IMRT was $16,842.75/QALY, making it the preferable treatment. The ICER was most sensitive to the probability of local recurrence, upfront radiation costs, local recurrence costs, certain utilities (no toxicity/no recurrence, grade 1 toxicity/no local recurrence, grade 4 toxicity/no local recurrence), and life expectancy. Dominance patterns emerged when the cost of 3DCRT exceeded $15,532.05 (IMRT dominates) or the life expectancy was under 1.68 years (3DCRT dominates). Furthermore, preference patterns changed based on the rate of local recurrence (threshold: 13%). The PSA results demonstrated that IMRT was the preferred cost-effective technique for 64% of trials compared with 36% for 3DCRT. Conclusions: Based on our model, IMRT is the preferred technique by lowering rates of local recurrence, severe toxicities, and improving QALYs. From a third-party payer perspective, IMRT should be a supported approach for extremity soft tissue sarcomas.

  18. Involved-Site Image-Guided Intensity Modulated Versus 3D Conformal Radiation Therapy in Early Stage Supradiaphragmatic Hodgkin Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Filippi, Andrea Riccardo, E-mail: andreariccardo.filippi@unito.it [Department of Oncology, University of Torino, Torino (Italy); Ciammella, Patrizia [Radiation Therapy Unit, Department of Oncology and Advanced Technology, ASMN Hospital IRCCS, Reggio Emilia (Italy); Piva, Cristina; Ragona, Riccardo [Department of Oncology, University of Torino, Torino (Italy); Botto, Barbara [Hematology, Città della Salute e della Scienza, Torino (Italy); Gavarotti, Paolo [Hematology, University of Torino and Città della Salute e della Scienza, Torino (Italy); Merli, Francesco [Hematology Unit, ASMN Hospital IRCCS, Reggio Emilia (Italy); Vitolo, Umberto [Hematology, Città della Salute e della Scienza, Torino (Italy); Iotti, Cinzia [Radiation Therapy Unit, Department of Oncology and Advanced Technology, ASMN Hospital IRCCS, Reggio Emilia (Italy); Ricardi, Umberto [Department of Oncology, University of Torino, Torino (Italy)

    2014-06-01

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows for margin reduction and highly conformal dose distribution, with consistent advantages in sparing of normal tissues. The purpose of this retrospective study was to compare involved-site IG-IMRT with involved-site 3D conformal RT (3D-CRT) in the treatment of early stage Hodgkin lymphoma (HL) involving the mediastinum, with efficacy and toxicity as primary clinical endpoints. Methods and Materials: We analyzed 90 stage IIA HL patients treated with either involved-site 3D-CRT or IG-IMRT between 2005 and 2012 in 2 different institutions. Inclusion criteria were favorable or unfavorable disease (according to European Organization for Research and Treatment of Cancer criteria), complete response after 3 to 4 cycles of an adriamycin- bleomycin-vinblastine-dacarbazine (ABVD) regimen plus 30 Gy as total radiation dose. Exclusion criteria were chemotherapy other than ABVD, partial response after ABVD, total radiation dose other than 30 Gy. Clinical endpoints were relapse-free survival (RFS) and acute toxicity. Results: Forty-nine patients were treated with 3D-CRT (54.4%) and 41 with IG-IMRT (45.6%). Median follow-up time was 54.2 months for 3D-CRT and 24.1 months for IG-IMRT. No differences in RFS were observed between the 2 groups, with 1 relapse each. Three-year RFS was 98.7% for 3D-CRT and 100% for IG-IMRT. Grade 2 toxicity events, mainly mucositis, were recorded in 32.7% of 3D-CRT patients (16 of 49) and in 9.8% of IG-IMRT patients (4 of 41). IG-IMRT was significantly associated with a lower incidence of grade 2 acute toxicity (P=.043). Conclusions: RFS rates at 3 years were extremely high in both groups, albeit the median follow-up time is different. Acute tolerance profiles were better for IG-IMRT than for 3D-CRT. Our preliminary results support the clinical safety and efficacy of advanced RT planning and delivery techniques in patients affected with early stage HL, achieving complete

  19. Radiation induced chromatin conformation changes analysed by fluorescent localization microscopy, statistical physics, and graph theory.

    Directory of Open Access Journals (Sweden)

    Yang Zhang

    Full Text Available It has been well established that the architecture of chromatin in cell nuclei is not random but functionally correlated. Chromatin damage caused by ionizing radiation raises complex repair machineries. This is accompanied by local chromatin rearrangements and structural changes which may for instance improve the accessibility of damaged sites for repair protein complexes. Using stably transfected HeLa cells expressing either green fluorescent protein (GFP labelled histone H2B or yellow fluorescent protein (YFP labelled histone H2A, we investigated the positioning of individual histone proteins in cell nuclei by means of high resolution localization microscopy (Spectral Position Determination Microscopy = SPDM. The cells were exposed to ionizing radiation of different doses and aliquots were fixed after different repair times for SPDM imaging. In addition to the repair dependent histone protein pattern, the positioning of antibodies specific for heterochromatin and euchromatin was separately recorded by SPDM. The present paper aims to provide a quantitative description of structural changes of chromatin after irradiation and during repair. It introduces a novel approach to analyse SPDM images by means of statistical physics and graph theory. The method is based on the calculation of the radial distribution functions as well as edge length distributions for graphs defined by a triangulation of the marker positions. The obtained results show that through the cell nucleus the different chromatin re-arrangements as detected by the fluorescent nucleosomal pattern average themselves. In contrast heterochromatic regions alone indicate a relaxation after radiation exposure and re-condensation during repair whereas euchromatin seemed to be unaffected or behave contrarily. SPDM in combination with the analysis techniques applied allows the systematic elucidation of chromatin re-arrangements after irradiation and during repair, if selected sub-regions of

  20. Erectile dysfunction after prostate three-dimensional conformal radiation therapy. Correlation with the dose to the penile bulb

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    Magli, A.; Ceschia, T.; Titone, F.; Parisi, G.; Fongione, S. [University Hospital Udine (Italy). Dept. of Radiation Oncology; Giangreco, M. [Udine Univ. (Italy). Hygiene and Epidemiology Inst.; Crespi, M.; Negri, A. [University Hospital Udine (Italy). Dept. of Medical Physics; De Giorgi, G. [University Hospital Udine (Italy). Dept. of Urology

    2012-11-15

    Purpose: Erectile dysfunction is associated with all the common treatment options for prostate cancer. The aim of this research was to evaluate the relationship between erectile function and radiation dose to the penile bulb (PB) and other proximal penile structures in men receiving conformal radiotherapy (CRT) without hormonal therapy (HT) for prostate cancer, whose sexual function was known before treatment. Patients and methods: The study included 19 patients treated with 3D-CRT for localized prostate cancer at our department, who were self-reported to be potent before treatment, had not received HT, and had complete follow-up data available. Our evaluation was based on the International Index of Erectile Function (IIEF-5). Dose-volume histograms (DVHs) were used to evaluate the dose to the PB. Statistical analysis was performed with an unconditional logistic regression model. Results: All patients reported change in potency after radiation. Eight patients (42%) remained potent but showed a decrease of 1 or 2 levels of potency, as defined by the IIEF-5 questionnaire (reduced potency group), while 11 patients (58%) reported a change of higher levels and revealed a severe erectile dysfunction after 2 years (impotence group). Multivariate analysis of morphological and dosimetric variables yielded significance for the mean dose (p = 0.05 with an odds ratio of 1.14 and 95% CI 1-1.30). Patients receiving a mean dose of less than 50 Gy to the PB appear to have a much greater likelihood of maintaining potency. Conclusion: Our data suggest a possible existence of a dose-volume correlation between the dose applied to the PB and radiation-induced impotence. (orig.)

  1. A dosimetric comparison of 3D conformal vs intensity modulated vs volumetric arc radiation therapy for muscle invasive bladder cancer

    Directory of Open Access Journals (Sweden)

    Foroudi Farshad

    2012-07-01

    Full Text Available Abstract Background To compare 3 Dimensional Conformal radiotherapy (3D-CRT with Intensity Modulated Radiotherapy (IMRT with Volumetric-Modulated Arc Therapy (VMAT for bladder cancer. Methods Radiotherapy plans for 15 patients with T2-T4N0M0 bladder cancer were prospectively developed for 3-DCRT, IMRT and VMAT using Varian Eclipse planning system. The same radiation therapist carried out all planning and the same clinical dosimetric constraints were used. 10 of the patients with well localised tumours had a simultaneous infield boost (SIB of the primary tumour planned for both IMRT and VMAT. Tumour control probabilities and normal tissue complication probabilities were calculated. Results Mean planning time for 3D-CRT, IMRT and VMAT was 30.0, 49.3, and 141.0 minutes respectively. The mean PTV conformity (CI index for 3D-CRT was 1.32, for IMRT 1.05, and for VMAT 1.05. The PTV Homogeneity (HI index was 0.080 for 3D-CRT, 0.073 for IMRT and 0.086 for VMAT. Tumour control and normal tissue complication probabilities were similar for 3D-CRT, IMRT and VMAT. The mean monitor units were 267 (range 250–293 for 3D-CRT; 824 (range 641–1083 for IMRT; and 403 (range 333–489 for VMAT (P  Conclusions VMAT is associated with similar dosimetric advantages as IMRT over 3D-CRT for muscle invasive bladder cancer. VMAT is associated with faster delivery times and less number of mean monitor units than IMRT. SIB is feasible in selected patients with localized tumours.

  2. Dose computation in conformal radiation therapy including geometric uncertainties: Methods and clinical implications

    Science.gov (United States)

    Rosu, Mihaela

    The aim of any radiotherapy is to tailor the tumoricidal radiation dose to the target volume and to deliver as little radiation dose as possible to all other normal tissues. However, the motion and deformation induced in human tissue by ventilatory motion is a major issue, as standard practice usually uses only one computed tomography (CT) scan (and hence one instance of the patient's anatomy) for treatment planning. The interfraction movement that occurs due to physiological processes over time scales shorter than the delivery of one treatment fraction leads to differences between the planned and delivered dose distributions. Due to the influence of these differences on tumors and normal tissues, the tumor control probabilities and normal tissue complication probabilities are likely to be impacted upon in the face of organ motion. In this thesis we apply several methods to compute dose distributions that include the effects of the treatment geometric uncertainties by using the time-varying anatomical information as an alternative to the conventional Planning Target Volume (PTV) approach. The proposed methods depend on the model used to describe the patient's anatomy. The dose and fluence convolution approaches for rigid organ motion are discussed first, with application to liver tumors and the rigid component of the lung tumor movements. For non-rigid behavior a dose reconstruction method that allows the accumulation of the dose to the deforming anatomy is introduced, and applied for lung tumor treatments. Furthermore, we apply the cumulative dose approach to investigate how much information regarding the deforming patient anatomy is needed at the time of treatment planning for tumors located in thorax. The results are evaluated from a clinical perspective. All dose calculations are performed using a Monte Carlo based algorithm to ensure more realistic and more accurate handling of tissue heterogeneities---of particular importance in lung cancer treatment planning.

  3. Two-Year and Lifetime Cost-Effectiveness of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Head-and-Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, Racquel E. [Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Sheets, Nathan C. [Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, North Carolina (United States); Wheeler, Stephanie B. [Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Nutting, Chris [Royal Marsden Hospital, London, United Kindom (United Kingdom); Hall, Emma [Clinical Trials and Statistics Unit, Division of Clinical Studies, Institute of Cancer Research, London (United Kingdom); Chera, Bhishamjit S., E-mail: bchera@med.unc.edu [Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, North Carolina (United States)

    2013-11-15

    Purpose: To assess the cost-effectiveness of intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of head-and neck-cancer (HNC). Methods and Materials: We used a Markov model to simulate radiation therapy-induced xerostomia and dysphagia in a hypothetical cohort of 65-year-old HNC patients. Model input parameters were derived from PARSPORT (CRUK/03/005) patient-level trial data and quality-of-life and Medicare cost data from published literature. We calculated average incremental cost-effectiveness ratios (ICERs) from the US health care perspective as cost per quality-adjusted life-year (QALY) gained and compared our ICERs with current cost-effectiveness standards whereby treatment comparators less than $50,000 per QALY gained are considered cost-effective. Results: In the first 2 years after initial treatment, IMRT is not cost-effective compared with 3D-CRT, given an average ICER of $101,100 per QALY gained. However, over 15 years (remaining lifetime on the basis of average life expectancy of a 65-year-old), IMRT is more cost-effective at $34,523 per QALY gained. Conclusion: Although HNC patients receiving IMRT will likely experience reduced xerostomia and dysphagia symptoms, the small quality-of-life benefit associated with IMRT is not cost-effective in the short term but may be cost-effective over a patient's lifetime, assuming benefits persist over time and patients are healthy and likely to live for a sustained period. Additional data quantifying the long-term benefits of IMRT, however, are needed.

  4. Practical aspects of inverse-planned intensity-modulated radiation therapy for prostate cancer: a radiation treatment planner's perspective.

    Science.gov (United States)

    Parker, William; Patrocinio, Horacio

    2005-06-01

    From a radiation treatment planner perspective, in the treatment of prostate cancer, inverse-planned intensity-modulated radiation therapy (IMRT) differs considerably from conventional, conformal, and forward-planned IMRT. In this work we aim to discuss the rationale behind the use of inverse-planned IMRT for the treatment of prostate cancer, as well as some of the practical aspects, including the differences in planning strategies, dose fractionation and issues in plan evaluation. The primary motivation behind the use of inverse-planned IMRT for prostate cancer radiotherapy is to attempt further dose escalation while maintaining critical structure and healthy tissue sparing at an acceptable level. The sparing of normal tissues is largely dependent on the size of the planning target volume (PTV) defined, and if the PTV overlaps critical structures. Depending on how the PTV is defined it may be impossible to achieve the desired healthy tissue sparing even with IMRT. A second role for the use of IMRT in the treatment of prostate cancer may be to conform the isodose distribution to a complex PTV, such as one that includes the seminal vesicles or the pelvic lymph nodes in the treatment volume. Finally, inverse planned IMRT may be useful in the planning and delivery of simultaneous integrated boosts where different parts of the target structures receive different daily doses. This again has applications for the simultaneous treatment of pelvic lymph nodes with the prostate treatment volume, and presents interesting opportunities for hypo-fractionation. All of these options of course require careful plan evaluation with respect to isodose distributions and dose-volume constraints as well as the radiobiological consequences of using unconventional fractionation. IMRT seems to be the most effective modality for treating complex target geometries and for delivering simultaneous integrated boosts. In particular for prostate cancer, the simultaneous treatment of the prostate

  5. Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the hypofractionated treatment of high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Yartsev Slav

    2008-01-01

    Full Text Available Abstract Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p dose, 1–3 Gy over 5/10 dose points; p Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.

  6. Comparison of 3D conformal radiotherapy vs. intensity modulated radiation therapy (IMRT) of a stomach cancer treatment;Comparacion dosimetrica de radioterapia conformal 3D versus radioterapia de intensidad modulada (IMRT) de un tratamiento de cancer de estomago

    Energy Technology Data Exchange (ETDEWEB)

    Bernui de V, Maria Giselle; Cardenas, Augusto; Vargas, Carlos [Hospital Nacional Carlos Alberto Seguin Escobedo (ESSALUD), Arequipa (Peru). Servicio de Radioterapia

    2009-07-01

    The purpose of this work was to compare the dosimetry in 3D Conformal Radiotherapy with Intensity Modulated Radiation Therapy (IMRT) in a treatment of stomach cancer. For this comparison we selected a patient who underwent subtotal gastrectomy and D2 dissection for a T3N3 adenocarcinoma Mx ECIIIB receiving treatment under the scheme Quimio INT 0116 - in adjuvant radiotherapy. In the treatment plan was contouring the Clinical Target Volume (CTV) and the Planning Target Volume (PTV) was generated from the expansion of 1cm of the CTV, the risky organs contouring were: the liver, kidneys and spinal cord, according to the consensus definition of volumes in gastric cancer. The 3D Conformal Radiotherapy planning is carried out using 6 half beams following the Leong Trevol technique; for the IMRT plan was used 8 fields, the delivery technique is step-and-shoot. In both cases the fields were coplanar, isocentric and the energy used was 18 MV. Intensity Modulated Radiation Therapy (IMRT), in this case has proved to be a good treatment alternative to the technique of 3D Conformal Radiotherapy; the dose distributions with IMRT have better coverage of PTV and positions of the hot spots, as well as the kidneys volume that received higher doses to 2000 cGy is lower, but the decrease in dose to the kidneys is at the expense of increased dose in other organs like the liver. (author)

  7. A comparison of out-of-field dose and its constituent components for intensity-modulated radiation therapy versus conformal radiation therapy: implications for carcinogenesis.

    Science.gov (United States)

    Ruben, Jeremy D; Lancaster, Craig M; Jones, Phillip; Smith, Ryan L

    2011-12-01

    To investigate differences in scatter and leakage between 6-MV intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT); to describe the relative contributions of internal patient scatter, collimator scatter, and head leakage; and to discuss implications for second cancer induction. Dose was measured at increasing distances from the field edge in a water bath with a sloping wall (1) under full scatter conditions, (2) with the field edge abutting but outside the bath to prevent internal (water) scatter, and (3) with the beam aperture plugged to reflect leakage only. Internal patient scatter from IMRT is 11% lower than 3DCRT, but collimator scatter and head leakage are five and three times higher, respectively. Ultimately, total scattered dose is 80% higher with IMRT; however this difference is small in absolute terms, being 0.14% of prescribed dose. Secondary dose from 3DCRT is mostly due to internal patient scatter, which contributes 70% of the total and predominates until 25 cm from the field edge. For IMRT, however, machine scatter/leakage is the dominant source, contributing 65% of the secondary dose. Internal scatter predominates for just the first 10 cm from field edge, collimator scatter for the next 10 cm, and head leakage thereafter. Out-of-field dose is 80% higher with IMRT, but differences are tiny in absolute terms. Reductions in internal patient scatter with IMRT are outweighed by increased machine scatter and leakage, at least for small fields. Reductions from IMRT in dose to tissues within the portals and in internal scatter, which predominates close to the field edge, means that calculations based solely on dose to distant tissues may overestimate carcinogenic risks. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  8. The changing costs of radiation treatment for early prostate cancer in Ontario: a comparison between conventional and conformal external beam radiotherapy.

    Science.gov (United States)

    Poon, Ian; Pintilie, Melania; Potvin, Mark; McGowan, Tom

    2004-02-01

    Prostate cancer represents a large part of the workload for radiation oncology departments in Canada. Recent evidence suggests that conformal external beam radiotherapy improves results. The planning and treatment process for conformal patients requires a greater amount of resources that are in short supply in Ontario. An understanding of these differences is important to provide an accurate estimate of future radiation needs of the province. These differences can be quantified in a cost model that portrays the direct costs of delivering external beam radiotherapy in Ontario. With a developed cost model, a prospective direct cost comparison between standard four field external beam radiotherapy versus conformal radiotherapy in early stage prostate carcinoma was designed. Activity based costing has been used to create a model of radiotherapy related costs for prostate cancer. A process map was developed which separated the process in five activities for conventional radiotherapy and six activities for dose escalated conformal radiotherapy. Time was recognized as the important cost driver within each activity. The time required for pre-treatment preparation (CT planning, dosimetry, simulation, and other preparatory work) and actual treatment times were collected prospectively. Treatment times were collected in 414 patients. The annual costs of capital equipment purchase costs and specialized construction of hospital space for radiotherapy equipment were amortized using a 6% discount rate plus the cost of annual maintenance. Indirect costs were not included in this cost analysis. An activity based costing model using time as the primary cost driver reflects the additional costs of conformal over conventional external beam radiotherapy. The costs of single phase and double phase six field conformal therapy with 42 fractions delivered was 7867 Canadian dollars and 8227 Canadian dollars per patient. Four field single phase conformal therapy with 28 fractions costs 5723

  9. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    OpenAIRE

    Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael; Gebski, Val

    2013-01-01

    Introduction A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. Methods CT data set...

  10. Investigation of conformal and intensity-modulated radiation therapy techniques to determine the absorbed fetal dose in pregnant patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Öğretici, Akın, E-mail: akinogretici@gmail.com; Akbaş, Uğur; Köksal, Canan; Bilge, Hatice

    2016-07-01

    The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for breast cancers. An Alderson Rando phantom was chosen to simulate a pregnant patient with breast cancer who is receiving radiation therapy. This phantom was irradiated using the Varian Clinac DBX 600 system (Varian Medical System, Palo Alto, CA) linear accelerator, according to the standard treatment plans of both three-dimensional conformal radiation therapy (3-D CRT) and IMRT techniques. Thermoluminescent dosimeters were used to measure the irradiated phantom's virtually designated uterus area. Thermoluminescent dosimeter measurements (in the phantom) revealed that the mean cumulative fetal dose for 3-D CRT is 1.39 cGy and for IMRT it is 8.48 cGy, for a pregnant breast cancer woman who received radiation treatment of 50 Gy. The fetal dose was confirmed to increase by 70% for 3-D CRT and 40% for IMRT, if it is closer to the irradiated field by 5 cm. The mean fetal dose from 3-D CRT is 1.39 cGy and IMRT is 8.48 cGy, consistent with theoretic calculations. The IMRT technique causes the fetal dose to be 5 times more than that of 3-D CRT. Theoretic knowledge concerning the increase in the peripheral doses as the measurements approached the beam was also practically proven.

  11. Conformational Transformations of Hemoglobin Molecules During in vivo Blood Irradiation by Low-Intensity Laser Radiation in the Red and Near IR Ranges

    Science.gov (United States)

    Zalesskaya, G. A.

    2014-07-01

    The effect of in vivo blood irradiation by low-intensity laser radiation on electronic-conformational interactions in hemoglobin molecules has been studied experimentally. The changes in the electronic and IR absorption spectra were followed for blood samples drawn at specific times during intravenous and supravascular irradiation, and also after dark reactions have occurred. The nature of the spectral changes observed is discussed. It is shown that the reversible photodissociation of hemoglobin-ligand complexes, initiated by blood irradiation, changes the oxyhemoglobin and deoxyhemoglobin levels, which leads to changes in the electronic absorption spectra of the blood and erythrocytes, and all the conformational transitions in the hemoglobin macromolecules accompanying ligand detachment and addition are responsible for the changes in their IR spectra.

  12. The role of Cobalt-60 source in Intensity Modulated Radiation Therapy: From modeling finite sources to treatment planning and conformal dose delivery

    Science.gov (United States)

    Dhanesar, Sandeep Kaur

    Cobalt-60 (Co-60) units played an integral role in radiation therapy from the mid-1950s to the 1970s. Although they continue to be used to treat cancer in some parts of the world, their role has been significantly reduced due to the invention of medical linear accelerators. A number of groups have indicated a strong potential for Co-60 units in modern radiation therapy. The Medical Physics group at the Cancer Center of the Southeastern Ontario and Queen's University has shown the feasibility of Intensity Modulated Radiation Therapy (IMRT) via simple conformal treatment planning and dose delivery using a Co-60 unit. In this thesis, initial Co-60 tomotherapy planning investigations on simple uniform phantoms are extended to actual clinical cases based on patient CT data. The planning is based on radiation dose data from a clinical Co-60 unit fitted with a multileaf collimator (MLC) and modeled in the EGSnrc Monte Carlo system. An in house treatment planning program is used to calculate IMRT dose distributions. Conformal delivery in a single slice on a uniform phantom based on sequentially delivered pencil beams is verified by Gafchromic film. Volumetric dose distributions for Co-60 serial tomotherapy are then generated for typical clinical sites that had been treated at our clinic by conventional 6MV IMRT using Varian Eclipse treatment plans. The Co-60 treatment plans are compared with the clinical IMRT plans using conventional matrices such as dose volume histograms (DVH). Dose delivery based on simultaneously opened MLC leaves is also explored and a novel MLC segmentation method is proposed. In order to increase efficiency of dose calculations, a novel convolution based fluence model for treatment planning is also proposed. The ion chamber measurements showed that the Monte Carlo modeling of the beam data under the MIMiC MLC is accurate. The film measurements from the uniform phantom irradiations confirm that IMRT plans from our in-house treatment planning system

  13. Predictive factors for Child-Pugh score elevation in hepatocellular carcinoma patients treated with conformal radiation therapy: dose-volume histogram analysis.

    Science.gov (United States)

    Yu, Jeong Il; Park, Hee Chul; Lim, Do Hoon; Park, Woo Yoon

    2013-01-01

    We designed the study to identify the clinical and dose-volumetric parameters associated with the risk of Child-Pugh score elevation in hepatocellular carcinoma patients treated with conformal radiation therapy. All 161 hepatocellular carcinoma patients in the study underwent 4D-computed tomography simulation, and a dose-volume histogram was generated after radiotherapy planning. Patients who had an elevated Child-Pugh (e-CP) score of 2 or more without progressive disease within 3 months were defined as e-CP positive. Twenty-six of 142 patients without progressive disease were e-CP positive. Pretreatment Child-Pugh class, further treatment within 30 days of radiotherapy, lymph node metastasis, mean liver dose, V(20 Gy), V(25 Gy), and V(30 Gy) were significantly correlated with e-CP positivity. The e-CP developed in 13 of 106 patients (12.3%) with V(30 Gy) of ≤28.1% and in 13 of 36 patients (36.1%) with V(30 Gy) >28.1% (P = 0.001). Our data demonstrate that mean liver dose, V(10 Gy), V(20 Gy), V(25 Gy), and V(30 Gy) are independent dose-volumetric predictors for e-CP positivity in hepatocellular carcinoma patients treated with conformal radiation therapy. V(30 Gy) should be limited to less than 28.1% to minimize the risk of e-CP.

  14. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    Energy Technology Data Exchange (ETDEWEB)

    Small, Katherine [Nepean Cancer Care Centre, Penrith, New South Wales 2750 (Australia); Kelly, Chris; Beldham-Collins, Rachael [Nepean Cancer Care Centre, Penrith, New South Wales 2750 (Australia); The Crown Princess Mary Cancer Centre, Westmead, New South Wales 2145 (Australia); Gebski, Val [NHMRC Clinical Trials Centre, University of Sydney, Sydney, New South Wales 2050 (Australia); Nepean Cancer Care Centre, Penrith, New South Wales 2750 (Australia)

    2013-03-15

    A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.

  15. Whole breast and excision cavity radiotherapy plan comparison: Conformal radiotherapy with sequential boost versus intensity-modulated radiation therapy with a simultaneously integrated boost

    Science.gov (United States)

    Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael; Gebski, Val

    2013-01-01

    Introduction A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. Methods CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy in 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. Results CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). Conclusion IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation. PMID:26229603

  16. Radiation-induced radicals in different polymorphic modifications of D-mannitol: Structure, conformations and dosimetric implications

    Science.gov (United States)

    Sosulin, Ilya S.; Shiryaeva, Ekaterina S.; Feldman, Vladimir I.

    2015-12-01

    The structure and conformation of radicals produced by X-ray irradiation of three polymorphic forms of D-mannitol were investigated using EPR spectroscopy. In all the cases, primary species were identified as radicals resulting from hydrogen abstraction from position 3 or 4 of the mannitol molecule. It was found that molecular packing in crystals of different polymorphic modifications had noticeable effect on the conformation of radicals observed after irradiation at room temperature and the dehydration of the primary radicals occurring at 400 K. The radicals trapped in stable modifications (β- and δ-forms) were found to be very stable at room temperature. Relatively high radical yields and remarkable stability of radicals suggest that D-mannitol can be used as an EPR dosimeter or irradiation marker.

  17. Prevention of normal tissue complications in radiation therapy of head and neck cancer : the role of 3D conformal radiation therapy (3DCRT)

    NARCIS (Netherlands)

    O.B. Wijers (Oda)

    2002-01-01

    textabstractIn The Netherlands. head and neck cancer (3.9%) ranks the eighth most frequemly diagnoscd malignant tumor. Radiation therapy (IIT) plays an important role in the treatmem of patients with head and neck cancer, as they constitute approximately 6% of those treated in a routine radiation

  18. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  19. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT)

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen, E-mail: stephen.avery@uphs.upenn.edu

    2014-07-01

    With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V{sub 18} {sub Gy}), stomach (mean and V{sub 20} {sub Gy}), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V{sub 18} {sub Gy}), liver (mean dose), total bowel (V{sub 20} {sub Gy} and mean dose), and small bowel (V{sub 15} {sub Gy} absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose

  20. Conformal house

    DEFF Research Database (Denmark)

    Ryttov, Thomas Aaby; Sannino, Francesco

    2010-01-01

    fixed point. As a consistency check we recover the previously investigated bounds of the conformal windows when restricting to a single matter representation. The earlier conformal windows can be imagined to be part now of the new conformal house. We predict the nonperturbative anomalous dimensions...... at the infrared fixed points. We further investigate the effects of adding mass terms to the condensates on the conformal house chiral dynamics and construct the simplest instanton induced effective Lagrangian terms...

  1. Three-dimensional conformal radiation for esophageal squamous cell carcinoma with involved-field irradiation may deliver considerable doses of incidental nodal irradiation

    Directory of Open Access Journals (Sweden)

    Ji Kai

    2012-11-01

    Full Text Available Abstract Background To quantify the incidental irradiation dose to esophageal lymph node stations when irradiating T1-4N0M0 thoracic esophageal squamous cell carcinoma (ESCC patients with a dose of 60 Gy/30f. Methods Thirty-nine patients with medically inoperable T1–4N0M0 thoracic ESCC were treated with three-dimensional conformal radiation (3DCRT with involved-field radiation (IFI. The conformal clinical target volume (CTV was re-created using a 3-cm margin in the proximal and distal direction beyond the barium esophagogram, endoscopic examination and CT scan defined the gross tumor volume (GTV and a 0.5-cm margin in the lateral and anteroposterior directions of the CT scan-defined GTV. The PTV encompassed 1-cm proximal and distal margins and 0.5-cm radial margin based on the CTV. Nodal regions were delineated using the Japanese Society for Esophageal Diseases (JSED guidelines and an EORTC-ROG expert opinion. The equivalent uniform dose (EUD and other dosimetric parameters were calculated for each nodal station. Nodal regions with a metastasis rate greater than 5% were considered a high-risk lymph node subgroup. Results Under a 60 Gy dosage, the median Dmean and EUD was greater than 40 Gy in most high-risk nodal regions except for regions of 104, 106tb-R in upper-thoracic ESCC and 101, 104-R, 105, 106rec-L, 2, 3&7 in middle-thoracic ESCC and 107, 3&7 in lower-thoracic ESCC. In the regions with an EUD less than 40Gy, most incidental irradiation doses were significantly associated with esophageal tumor length and location. Conclusions Lymph node stations near ESCC receive considerable incidental irradiation doses with involved-field irradiation that may contribute to the elimination of subclinical lesions.

  2. Biological Modeling Based Outcome Analysis (BMOA) in 3D Conformal Radiation Therapy (3DCRT) Treatments for Lung and Breast Cancers

    Science.gov (United States)

    Pyakuryal, Anil; Chen, Chiu-Hao; Dhungana, Sudarshan

    2010-03-01

    3DCRT treatments are the most commonly used techniques in the treatment of lung and breast cancers. The purpose of this study was to perform the BMOA of the 3DCRT plans designed for the treatment of breast and lung cancers utilizing HART program (Med. Phys. 36, p.2547(2009)). The BMOA parameters include normal tissue complication probability (NTCP), tumor control probability (TCP), and the complication-free tumor control probability (P+). The 3DCRT plans were designed for (i) the palliative treatment of 8 left lung cancer patients (CPs) at early stage (m=8), (ii) the curative treatment of 8 left lung CPs at stages II and III (k=8), and (iii) the curative treatment of 8 left breast CPs (n=8). The NTCPs were noticeably small (<2%) for heart, lungs and cord in both types of treatments except for the esophagus in lung CPs (k=8). Assessments of the TCPs and P+s also indicated good improvements in local tumor control in all plans. Homogeneous target coverage and improved dose conformality were the major advantages of such techniques in the treatment of breast cancer. These achievements support the efficacy of the 3DCRT techniques for the efficient treatment of various types of cancer.

  3. Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy.

    Science.gov (United States)

    Martínez-Arribas, C M; González-San Segundo, C; Cuesta-Álvaro, P; Calvo-Manuel, F A

    2017-06-15

    To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors. A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance. The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy. The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy. Copyright © 2017 AEU. Publicado por Elsevier España, S

  4. Analysis of Intensity-Modulated Radiation Therapy (IMRT), Proton and 3D Conformal Radiotherapy (3D-CRT) for Reducing Perioperative Cardiopulmonary Complications in Esophageal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Ted C.; Slater, Jerry M.; Nookala, Prashanth; Mifflin, Rachel; Grove, Roger; Ly, Anh M.; Patyal, Baldev; Slater, Jerry D.; Yang, Gary Y., E-mail: gyang@llu.edu [Department of Radiation Medicine, Loma Linda University Medical Center, 11234 Anderson Street, A875, Loma Linda, CA 92354 (United States)

    2014-12-05

    Background. While neoadjuvant concurrent chemoradiotherapy has improved outcomes for esophageal cancer patients, surgical complication rates remain high. The most frequent perioperative complications after trimodality therapy were cardiopulmonary in nature. The radiation modality utilized can be a strong mitigating factor of perioperative complications given the location of the esophagus and its proximity to the heart and lungs. The purpose of this study is to make a dosimetric comparison of Intensity-Modulated Radiation Therapy (IMRT), proton and 3D conformal radiotherapy (3D-CRT) with regard to reducing perioperative cardiopulmonary complications in esophageal cancer patients. Materials. Ten patients with esophageal cancer treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using proton radiotherapy, IMRT, and 3D-CRT modalities were created for each patient. Dose-volume histograms were calculated and analyzed to compare plans between the three modalities. The organs at risk (OAR) being evaluated in this study are the heart, lungs, and spinal cord. To determine statistical significance, ANOVA and two-tailed paired t-tests were performed for all data parameters. Results. The proton plans showed decreased dose to various volumes of the heart and lungs in comparison to both the IMRT and 3D-CRT plans. There was no difference between the IMRT and 3D-CRT plans in dose delivered to the lung or heart. This finding was seen consistently across the parameters analyzed in this study. Conclusions. In patients receiving radiation therapy for esophageal cancer, proton plans are technically feasible while achieving adequate coverage with lower doses delivered to the lungs and cardiac structures. This may result in decreased cardiopulmonary toxicity and less morbidity to esophageal cancer patients.

  5. Analysis of Intensity-Modulated Radiation Therapy (IMRT, Proton and 3D Conformal Radiotherapy (3D-CRT for Reducing Perioperative Cardiopulmonary Complications in Esophageal Cancer Patients

    Directory of Open Access Journals (Sweden)

    Ted C. Ling

    2014-12-01

    Full Text Available Background. While neoadjuvant concurrent chemoradiotherapy has improved outcomes for esophageal cancer patients, surgical complication rates remain high. The most frequent perioperative complications after trimodality therapy were cardiopulmonary in nature. The radiation modality utilized can be a strong mitigating factor of perioperative complications given the location of the esophagus and its proximity to the heart and lungs. The purpose of this study is to make a dosimetric comparison of Intensity-Modulated Radiation Therapy (IMRT, proton and 3D conformal radiotherapy (3D-CRT with regard to reducing perioperative cardiopulmonary complications in esophageal cancer patients. Materials. Ten patients with esophageal cancer treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using proton radiotherapy, IMRT, and 3D-CRT modalities were created for each patient. Dose-volume histograms were calculated and analyzed to compare plans between the three modalities. The organs at risk (OAR being evaluated in this study are the heart, lungs, and spinal cord. To determine statistical significance, ANOVA and two-tailed paired t-tests were performed for all data parameters. Results. The proton plans showed decreased dose to various volumes of the heart and lungs in comparison to both the IMRT and 3D-CRT plans. There was no difference between the IMRT and 3D-CRT plans in dose delivered to the lung or heart. This finding was seen consistently across the parameters analyzed in this study. Conclusions. In patients receiving radiation therapy for esophageal cancer, proton plans are technically feasible while achieving adequate coverage with lower doses delivered to the lungs and cardiac structures. This may result in decreased cardiopulmonary toxicity and less morbidity to esophageal cancer patients.

  6. Five-year outcomes, cosmesis, and toxicity with 3-dimensional conformal external beam radiation therapy to deliver accelerated partial breast irradiation.

    Science.gov (United States)

    Rodríguez, Núria; Sanz, Xavier; Dengra, Josefa; Foro, Palmira; Membrive, Ismael; Reig, Anna; Quera, Jaume; Fernández-Velilla, Enric; Pera, Óscar; Lio, Jackson; Lozano, Joan; Algara, Manuel

    2013-12-01

    To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (Pbreast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Size reduction and radiation pattern shaping of multi-fed DCC slot antennas used in conformal microwave array hyperthermia applicators

    Science.gov (United States)

    Maccarini, Paolo F.; Arunachalam, Kavitha; Martins, Carlos D.; Stauffer, Paul R.

    2009-02-01

    The use of conformal antenna array in the treatment of superficial diseases can significantly increase patient comfort while enhancing the local control of large treatment area with irregular shapes. Originally a regular square multi-fed slot antenna (Dual Concentric Conductor - DCC) was proposed as basic unit cell of the array. The square DCC works well when the outline of the treatment area is rectangular such as in the main chest or back area but is not suitable to outline diseases spreading along the armpit and neck area. In addition as the area of the patch increases, the overall power density decreases affecting the efficiency and thus the ability to deliver the necessary thermal dose with medium power amplifier (area while increasing the perimeter of the slot, thus increasing the antenna efficiency and the power density. The simulation performed with several commercial packages (Ansoft HFSS, Imst Empire, SemcadX and CST Microwave Studio) show that the size reducing method can be applied to several shapes and for different frequencies. The SAR measurements of several DCCs are performed using an in-house high resolution scanning system with tumor equivalent liquid phantom both at 915 MHz for superficial hyperthermia systems in US) and 433 MHz (Europe). The experimental results are compared with the expected theoretical predictions and both simulated and measured patterns of single antennas of various size and shapes are then summed in various combinations using Matlab to show possible treatment irregular contours of complex diseases. The local control is expected to significantly improve while maintaining the patient comfort.

  8. A decision model to estimate the cost-effectiveness of intensity modulated radiation therapy (IMRT) compared to three dimensional conformal radiation therapy (3DCRT) in patients receiving radiotherapy to the prostate bed.

    Science.gov (United States)

    Carter, Hannah E; Martin, Andrew; Schofield, Deborah; Duchesne, Gillian; Haworth, Annette; Hornby, Colin; Sidhom, Mark; Jackson, Michael

    2014-08-01

    Intensity modulated radiation therapy (IMRT) is a radiation therapy technology that facilitates the delivery of an improved dose distribution with less dose to surrounding critical structures. This study estimates the longer term effectiveness and cost-effectiveness of IMRT in patients post radical prostatectomy. A Markov decision model was developed to calculate the incremental quality adjusted life years (QALYs) and costs of IMRT compared with three dimensional conformal radiation therapy (3DCRT). Costs were estimated from the perspective of the Australian health care system. IMRT was both more effective and less costly than 3DCRT over 20 years, with an additional 20 QALYs gained and over $1.1 million saved per 1000 patients treated. This result was robust to plausible levels of uncertainty. IMRT was estimated to have a modest long term advantage over 3DCRT in terms of both improved effectiveness and reduced cost. This result was reliant on clinical judgement and interpretation of the existing literature, but provides quantitative guidance on the cost effectiveness of IMRT whilst long term trial evidence is awaited. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Transportation Conformity

    Science.gov (United States)

    This section provides information on: current laws, regulations and guidance, policy and technical guidance, project-level conformity, general information, contacts and training, adequacy review of SIP submissions

  10. Intraoperative radiation therapy in combination with conformation radiation therapy for localized unresectable pancreatic carcinoma; An analysis of 13 patients survived for more than one year

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Atsutake; Tsuruta, Kohji; Tanaka, Yoshiaki (Tokyo Metropolitan Komagome Hospital (Japan)); Onodera, Tokio

    1992-04-01

    The present report is a retrospective analysis of the effect of intraoperative radiation therapy (IORT) for localized but unresectable pancreatic carcinoma. Thirteen of 30 patients treated by IORT in combination with external beam radiation therapy (EBRT) survived for more than one year. The longest survival period, attained by two patients, was 20 months. The 1, and 1.5-year survival rates were 46.5% and 20.8%, respectively, with a median survival of 11 months, whereas the 1-year survival rate was 0%, with a median survival of 6.2 months for the 16 patients treated by IORT alone (N=16). There was a statistically significant difference in survival rate between the two groups (p<0.01). Therefore, additional EBRT may be indispensable for prolongation of the survival period. Moreover, IORT conferred the palliative benefit of relief of pain in more than half of the patients with severe pain. In postmortem examination of seven patients who survived for more than one year, the tumors were replaced by fibrous and hyalinized tissue, as a result of the effect of IORT, and degeneration and necrosis of tumor cells were seen in the center of the tumor, while viable tumor cells remained in the periphery, spreading to the retroperitoneal tissues or neighboring organs. These histopathological findings are distinctive features of carcinoma of the pancreas treated by IORT. (author).

  11. Stereotactic Ablative Body Radiation Therapy for Primary Kidney Cancer: A 3-Dimensional Conformal Technique Associated With Low Rates of Early Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Daniel, E-mail: daniel.pham@petermac.org [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Victoria (Australia); Thompson, Ann [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Foroudi, Farshad [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Department of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Kolsky, Michal Schneider [Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Victoria (Australia); Devereux, Thomas; Lim, Andrew [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Siva, Shankar [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Department of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)

    2014-12-01

    Purpose: To describe our 3-dimensional conformal planning approaches and report early toxicities with stereotactic body radiation therapy for the management of primary renal cell carcinoma. Methods and Materials: This is an analysis of a phase 1 trial of stereotactic body radiation therapy for primary inoperable renal cell carcinoma. A dose of 42 Gy/3 fractions was prescribed to targets ≥5 cm, whereas for <5 cm 26 Gy/1 fraction was used. All patients underwent a planning 4-dimensional CT to generate a planning target volume (PTV) from a 5-mm isotropic expansion of the internal target volume. Planning required a minimum of 8 fields prescribing to the minimum isodose surrounding the PTV. Intermediate dose spillage at 50% of the prescription dose (R50%) was measured to describe the dose gradient. Early toxicity (<6 months) was scored using the Common Terminology Criteria for Adverse Events (v4.0). Results: From July 2012 to August 2013 a total of 20 patients (median age, 77 years) were recruited into a prospective clinical trial. Eleven patients underwent fractionated treatment and 9 patients a single fraction. For PTV targets <100 cm{sup 3} the median number of beams used was 8 (2 noncoplanar) to achieve an average R50% of 3.7. For PTV targets >100 cm{sup 3} the median beam number used was 10 (4 noncoplanar) for an average R50% value of 4.3. The R50% was inversely proportional to decreasing PTV volume (r=−0.62, P=.003) and increasing total beams used (r=−0.51, P=.022). Twelve of 20 patients (60%) suffered grade ≤2 early toxicity, whereas 8 of 20 patients (40%) were asymptomatic. Nausea, chest wall pain, and fatigue were the most common toxicities reported. Conclusion: A 3-dimensional conformal planning technique of 8-10 beams can be used to deliver highly tolerable stereotactic ablation to primary kidney targets with minimal early toxicities. Ongoing follow-up is currently in place to assess long-term toxicities and cancer control.

  12. Workers’ Conformism

    Directory of Open Access Journals (Sweden)

    Nikolay Ivantchev

    2013-10-01

    Full Text Available Conformism was studied among 46 workers with different kinds of occupations by means of two modified scales measuring conformity by Santor, Messervey, and Kusumakar (2000 – scale for perceived peer pressure and scale for conformism in antisocial situations. The hypothesis of the study that workers’ conformism is expressed in a medium degree was confirmed partly. More than a half of the workers conform in a medium degree for taking risk, and for the use of alcohol and drugs, and for sexual relationships. More than a half of the respondents conform in a small degree for anti-social activities (like a theft. The workers were more inclined to conform for risk taking (10.9%, then – for the use of alcohol, drugs and for sexual relationships (8.7%, and in the lowest degree – for anti-social activities (6.5%. The workers who were inclined for the use of alcohol and drugs tended also to conform for anti-social activities.

  13. Treatment-Related Morbidity in Prostate Cancer: A Comparison of 3-Dimensional Conformal Radiation Therapy With and Without Image Guidance Using Implanted Fiducial Markers

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jasmeet, E-mail: drsingh.j@gmail.com [Calvary Mater Newcastle, Newcastle (Australia); Greer, Peter B. [School of Physical and Mathematical Sciences, University of Newcastle, Newcastle (Australia); White, Martin A. [School of Medicine and Public Health, University of Newcastle, Newcastle (Australia); Parker, Joel; Patterson, Jackie [Calvary Mater Newcastle, Newcastle (Australia); Tang, Colin I.; Capp, Anne; Wratten, Christopher; Denham, James W. [Calvary Mater Newcastle, Newcastle (Australia); School of Medicine and Public Health, University of Newcastle, Newcastle (Australia)

    2013-03-15

    Purpose: To estimate the prevalence of rectal and urinary dysfunctional symptoms using image guided radiation therapy (IGRT) with fiducials and magnetic resonance planning for prostate cancer. Methods and Materials: During the implementation stages of IGRT between September 2008 and March 2010, 367 consecutive patients were treated with prostatic irradiation using 3-dimensional conformal radiation therapy with and without IGRT (non-IGRT). In November 2010, these men were asked to report their bowel and bladder symptoms using a postal questionnaire. The proportions of patients with moderate to severe symptoms in these groups were compared using logistic regression models adjusted for tumor and treatment characteristic variables. Results: Of the 282 respondents, the 154 selected for IGRT had higher stage tumors, received higher prescribed doses, and had larger volumes of rectum receiving high dosage than did the 128 selected for non-IGRT. The follow-up duration was 8 to 26 months. Compared with the non-IGRT group, improvement was noted in all dysfunctional rectal symptoms using IGRT. In multivariable analyses, IGRT improved rectal pain (odds ratio [OR] 0.07 [0.009-0.7], P=.02), urgency (OR 0.27 [0.11-0.63], P=<.01), diarrhea (OR 0.009 [0.02-0.35], P<.01), and change in bowel habits (OR 0.18 [0.06-0.52], P<.010). No correlation was observed between rectal symptom levels and dose-volume histogram data. Urinary dysfunctional symptoms were similar in both treatment groups. Conclusions: In comparison with men selected for non-IGRT, a significant reduction of bowel dysfunctional symptoms was confirmed in men selected for IGRT, even though they had larger volumes of rectum treated to higher doses.

  14. On-line estimations of delivered radiation doses in three-dimensional conformal radiotherapy treatments of carcinoma uterine cervix patients in linear accelerator

    Directory of Open Access Journals (Sweden)

    Suman Kumar Putha

    2016-01-01

    Full Text Available Transmission of radiation fluence through patient′s body has a correlation to the planned target dose. A method to estimate the delivered dose to target volumes was standardized using a beam level 0.6 cc ionization chamber (IC positioned at electronic portal imaging device (EPID plane from the measured transit signal (S t in patients with cancer of uterine cervix treated with three-dimensional conformal radiotherapy (3DCRT. The IC with buildup cap was mounted on linear accelerator EPID frame with fixed source to chamber distance of 146.3 cm, using a locally fabricated mount. S t s were obtained for different water phantom thicknesses and radiation field sizes which were then used to generate a calibration table against calculated midplane doses at isocenter (D iso,TPS , derived from the treatment planning system. A code was developed using MATLAB software which was used to estimate the in vivo dose at isocenter (D iso,Transit from the measured S t s. A locally fabricated pelvic phantom validated the estimations of D iso,Transit before implementing this method on actual patients. On-line dose estimations were made (3 times during treatment for each patient in 24 patients. The D iso,Transit agreement with D iso,TPS in phantom was within 1.7% and the mean percentage deviation with standard deviation is −1.37% ±2.03% (n = 72 observed in patients. Estimated in vivo dose at isocenter with this method provides a good agreement with planned ones which can be implemented as part of quality assurance in pelvic sites treated with simple techniques, for example, 3DCRT where there is a need for documentation of planned dose delivery.

  15. Comparison of Toxicity between Intensity-Modulated Radiation Therapy and 3-Dimensional Conformal Radiotherapy for Locally Advanced Non-Small Cell Lung Cancer

    Science.gov (United States)

    Ling, Diane C.; Hess, Clayton B.; Chen, Allen M.; Daly, Megan E.

    2015-01-01

    Background The role of intensity-modulated radiation therapy (IMRT) in reducing treatment-related toxicity for locally advanced non-small cell lung cancer (NSCLC) remains incompletely defined. We compared acute toxicity and oncologic outcomes in a large cohort of patients treated with IMRT or 3D conformal radiation therapy (3DCRT), with or without elective nodal irradiation (ENI). Methods A single-institution retrospective review was performed evaluating 145 consecutive patients with histologically-confirmed stage III NSCLC treated with definitive chemoradiation. Sixty-five (44.8%) were treated with 3DCRT using ENI, 43 (30.0%) with 3DCRT using involved-field radiotherapy (IFRT), and 37 (25.5%) with IMRT using IFRT. All patients received concurrent chemotherapy. Comparison of acute toxicities by treatment technique (IMRT vs. 3DCRT) and extent of nodal irradiation (3DCRT-IFRT vs. 3DCRT-ENI) was performed for grade ≥2 esophagitis or pneumonitis, number of acute hospitalizations, incidence of opioid requirement, PEG utilization, and percent weight loss during treatment. Local control and overall survival were analyzed with the Kaplan-Meier method. Results We identified no significant differences in any measures of acute toxicity by treatment technique or extent of nodal irradiation. There was a trend toward lower rates of grade ≥2 pneumonitis among IMRT patients compared to 3DCRT patients (5.4% vs. 23.0%, p=0.065). Local control and overall survival were similar between cohorts. Conclusions Acute and sub-acute toxicities were similar for patients treated with IMRT and with 3DCRT ± ENI, with a non-significant trend toward a reduction in pneumonitis with IMRT. Larger studies are needed to better define which patients will benefit from IMRT. PMID:26303127

  16. Predictors of grade {>=}2 and grade {>=}3 radiation pneumonitis in patients with locally advanced non-small cell lung cancer treated with three-dimensional conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Jun; Li, Guang; Ma, Lianghua; Han, Chong; Zhang, Shuo; Yao, Lei [Dept. of Radiation Oncology, The First Hospital of China Medical Univ., Shenyang (China)], e-mail: gl1963516@yahoo.cn; Diao, Rao [Dept. of Experimental Technology Center, China Medical Univ., Shenyang (China); Zang, Shuang [Dept. of Nursing, China Medical Univ., Shenyang (China)

    2013-08-15

    Grade {>=}3 radiation pneumonitis (RP) is generally severe and life-threatening. Predictors of grade {>=}2 are usually used for grade {>=}3 RP prediction, but it is unclear whether these predictors are appropriate. In this study, predictors of grade {>=}2 and grade {>=}3 RP were investigated separately. The increased risk of severe RP in elderly patients compared with younger patients was also evaluated. Material and methods: A total of 176 consecutive patients with locally advanced non-small cell lung cancer were followed up prospectively after three-dimensional conformal radiotherapy. RP was graded according to Common Terminology Criteria for Adverse Events version 3.0. Results: Mean lung dose (MLD), mean heart dose, ratio of planning target volume to total lung volume (PTV/Lung), and dose-volume histogram comprehensive value of both heart and lung were associated with both grade {>=}2 and grade {>=}3 RP in univariate analysis. In multivariate logistic regression analysis, age and MLD were predictors of both grade {>=}2 RP and grade {>=}3 RP; receipt of chemotherapy predicted grade {>=}3 RP only; and sex and PTV/Lung predicted grade {>=}2 RP only. Among patients who developed high-grade RP, MLD and PTV/Lung were significantly lower in patients aged {>=}70 years than in younger patients (p<0.05 for both comparisons). Conclusions: The predictors were not completely consistent between grade {>=}2 RP and grade {>=}3 RP. Elderly patients had a higher risk of severe RP than younger patients did, possibly due to lower tolerance of radiation to the lung.

  17. Acute Toxicity After Image-Guided Intensity Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy in Prostate Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Wortel, Ruud C.; Incrocci, Luca [Department of Radiation Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Pos, Floris J.; Lebesque, Joos V.; Witte, Marnix G.; Heide, Uulke A. van der; Herk, Marcel van [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands); Heemsbergen, Wilma D., E-mail: w.heemsbergen@nki.nl [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands)

    2015-03-15

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows significant dose reductions to organs at risk in prostate cancer patients. However, clinical data identifying the benefits of IG-IMRT in daily practice are scarce. The purpose of this study was to compare dose distributions to organs at risk and acute gastrointestinal (GI) and genitourinary (GU) toxicity levels of patients treated to 78 Gy with either IG-IMRT or 3D-CRT. Methods and Materials: Patients treated with 3D-CRT (n=215) and IG-IMRT (n=260) receiving 78 Gy in 39 fractions within 2 randomized trials were selected. Dose surface histograms of anorectum, anal canal, and bladder were calculated. Identical toxicity questionnaires were distributed at baseline, prior to fraction 20 and 30 and at 90 days after treatment. Radiation Therapy Oncology Group (RTOG) grade ≥1, ≥2, and ≥3 endpoints were derived directly from questionnaires. Univariate and multivariate binary logistic regression analyses were applied. Results: The median volumes receiving 5 to 75 Gy were significantly lower (all P<.001) with IG-IMRT for anorectum, anal canal, and bladder. The mean dose to the anorectum was 34.4 Gy versus 47.3 Gy (P<.001), 23.6 Gy versus 44.6 Gy for the anal canal (P<.001), and 33.1 Gy versus 43.2 Gy for the bladder (P<.001). Significantly lower grade ≥2 toxicity was observed for proctitis, stool frequency ≥6/day, and urinary frequency ≥12/day. IG-IMRT resulted in significantly lower overall RTOG grade ≥2 GI toxicity (29% vs 49%, respectively, P=.002) and overall GU grade ≥2 toxicity (38% vs 48%, respectively, P=.009). Conclusions: A clinically meaningful reduction in dose to organs at risk and acute toxicity levels was observed in IG-IMRT patients, as a result of improved technique and tighter margins. Therefore reduced late toxicity levels can be expected as well; additional research is needed to quantify such reductions.

  18. An investigation of intensity-modulated radiation therapy versus conventional two-dimensional and 3D-conformal radiation therapy for early stage larynx cancer

    Directory of Open Access Journals (Sweden)

    Gomez Daniel

    2010-08-01

    Full Text Available Abstract Introduction Intensity modulated radiation therapy (IMRT has been incorporated at several institutions for early stage laryngeal cancer (T1/T2N0M0, but its utility is controversial. Methods In three representative patients, multiple plans were generated: 1 Conventional 2D planning, with the posterior border placed at either the anterior aspect ("tight" plan or the mid-vertebral body ("loose" plan, 2 3D planning, utilizing both 1.0 and 0.5 cm margins for the planning target volume (PTV, and 3 IMRT planning, utilizing the same margins as the 3D plans. A dosimetric comparison was performed for the target volume, spinal cord, arytenoids, and carotid arteries. The prescription dose was 6300 cGy (225 cGy fractions, and the 3D and IMRT plans were normalized to this dose. Results For PTV margins of 1.0 cm and 0.5 cm, the D95 of the 2D tight/loose plans were 3781/5437 cGy and 5372/5869 cGy, respectively (IMRT/3D plans both 6300 cGy. With a PTV margin of 1.0 cm, the mean carotid artery dose was 2483/5671/5777/4049 cGy in the 2D tight, 2D loose, 3D, and IMRT plans, respectively. When the PTV was reduced to 0.5 cm, the the mean carotid artery dose was 2483/5671/6466/2577 cGy to the above four plans, respectively. The arytenoid doses were similar between the four plans, and spinal cord doses were well below tolerance. Conclusions IMRT provides a more ideal dose distribution compared to 2D treatment and 3D planning in regards to mean carotid dose. We therefore recommend IMRT in select cases when the treating physician is confident with the GTV.

  19. Five-Year Outcomes, Cosmesis, and Toxicity With 3-Dimensional Conformal External Beam Radiation Therapy to Deliver Accelerated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Núria, E-mail: nrodriguez@parcdesalutmar.cat [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Sanz, Xavier [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Dengra, Josefa [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Foro, Palmira [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Membrive, Ismael; Reig, Anna [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Quera, Jaume [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Fernández-Velilla, Enric; Pera, Óscar; Lio, Jackson; Lozano, Joan [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Algara, Manuel [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain)

    2013-12-01

    Purpose: To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). Methods and Materials: 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. Results: The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. Conclusions: APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with

  20. In vivo dosimetry with optically stimulated luminescent dosimeters for conformal and intensity-modulated radiation therapy: A 2-year multicenter cohort study.

    Science.gov (United States)

    Riegel, Adam C; Chen, Yu; Kapur, Ajay; Apicello, Laura; Kuruvilla, Abraham; Rea, Anthony J; Jamshidi, Abolghassem; Potters, Louis

    Optically stimulated luminescent dosimeters (OSLDs) are utilized for in vivo dosimetry (IVD) of modern radiation therapy techniques such as intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). Dosimetric precision achieved with conventional techniques may not be attainable. In this work, we measured accuracy and precision for a large sample of clinical OSLD-based IVD measurements. Weekly IVD measurements were collected from 4 linear accelerators for 2 years and were expressed as percent differences from planned doses. After outlier analysis, 10,224 measurements were grouped in the following way: overall, modality (photons, electrons), treatment technique (3-dimensional [3D] conformal, field-in-field intensity modulation, inverse-planned IMRT, and VMAT), placement location (gantry angle, cardinality, and central axis positioning), and anatomical site (prostate, breast, head and neck, pelvis, lung, rectum and anus, brain, abdomen, esophagus, and bladder). Distributions were modeled via a Gaussian function. Fitting was performed with least squares, and goodness-of-fit was assessed with the coefficient of determination. Model means (μ) and standard deviations (σ) were calculated. Sample means and variances were compared for statistical significance by analysis of variance and the Levene tests (α = 0.05). Overall, μ ± σ was 0.3 ± 10.3%. Precision for electron measurements (6.9%) was significantly better than for photons (10.5%). Precision varied significantly among treatment techniques (P < .0001) with field-in-field lowest (σ = 7.2%) and IMRT and VMAT highest (σ = 11.9% and 13.4%, respectively). Treatment site models with goodness-of-fit greater than 0.90 (6 of 10) yielded accuracy within ±3%, except for head and neck (μ = -3.7%). Precision varied with treatment site (range, 7.3%-13.0%), with breast and head and neck yielding the best and worst precision, respectively. Placement on the central axis of cardinal gantry

  1. Rapid Arc, helical tomotherapy, sliding window intensity modulated radiotherapy and three dimensional conformal radiation for localized prostate cancer: A dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Rajesh A Kinhikar

    2014-01-01

    Full Text Available Objective: The objective of this study was to investigate the potential role of RapidArc (RA compared with helical tomotherapy (HT, sliding window intensity modulated radiotherapy (SW IMRT and three-dimensional conformal radiation therapy (3D CRT for localized prostate cancer. Materials and Methods: Prescription doses ranged from 60 Gy to planning target volume (PTV and 66.25 Gy for clinical target volume prostate (CTV-P over 25-30 fractions. PTV and CTV-P coverage were evaluated by conformity index (CI and homogeneity index (HI. Organ sparing comparison was done with mean doses to rectum and bladder. Results: CI 95 were 1.0 ± 0.01 (RA, 0.99 ± 0.01 (HT, 0.97 ± 0.02 (IMRT, 0.98 ± 0.02 (3D CRT for PTV and 1.0 ± 0.00 (RA, HT, SW IMRT and 3D CRT for CTV-P. HI was 0.11 ± 0.03 (RA, 0.16 ± 0.08 (HT, 0.12 ± 0.03 (IMRT, 0.06 ± 0.01 (3D CRT for PTV and 0.03 ± 0.00 (RA, 0.05 ± 0.01 (HT, 0.03 ± 0.01 (SW IMRT and 3D CRT for CTV-P. Mean dose to bladder were 23.68 ± 13.23 Gy (RA, 24.55 ± 12.51 Gy (HT, 19.82 ± 11.61 Gy (IMRT and 23.56 ± 12.81 Gy (3D CRT, whereas mean dose to rectum was 36.85 ± 12.92 Gy (RA, 33.18 ± 11.12 Gy (HT, IMRT and 38.67 ± 12.84 Gy (3D CRT. Conclusion: All studied intensity-modulated techniques yield treatment plans of significantly improved quality when compared with 3D CRT, with HT providing best organs at risk sparing and RA being the most efficient treatment option, reducing treatment time to 1.45-3.7 min and monitor unit to <400 for a 2 Gy fraction.

  2. General Conformity

    Science.gov (United States)

    The General Conformity requirements ensure that the actions taken by federal agencies in nonattainment and maintenance areas do not interfere with a state’s plans to meet national standards for air quality.

  3. Maintenance of Sorafenib following combined therapy of three-dimensional conformal radiation therapy/intensity-modulated radiation therapy and transcatheter arterial chemoembolization in patients with locally advanced hepatocellular carcinoma: a phase I/II study

    Directory of Open Access Journals (Sweden)

    Chen Zhen

    2010-02-01

    Full Text Available Abstract Background Three-dimensional conformal radiation therapy (3DCRT/intensity-modulated radiation therapy (IMRT combined with or without transcatheter arterial chemoembolization (TACE for locally advanced hepatocellular carcinoma (HCC has shown favorable outcomes in local control and survival of locally advanced HCC. However, intra-hepatic spreading and metastasis are still the predominant treatment failure patterns. Sorafenib is a multikinase inhibitor with effects against tumor proliferation and angiogenesis. Maintenance Sorafenib would probably prevent or delay the intrahepatic and extrahepatic spread of HCC after radiotherapy, which provides the rationale for the combination of these treatment modalities. Methods and design Patients with solitary lesion (bigger than 5 cm in diameter histologically or cytologically confirmed HCC receive TACE (1-3 cycles plus 3DCRT/IMRT 4-6 weeks later. Maintenance Sorafenib will be administered only for the patients with non-progression disease 4 to 6 weeks after the completion of radiotherapy. The dose will be 400 mg, p.o., twice a day. Sorafenib will be continuously given for 12 months unless intolerable toxicities and/or tumor progression. If no more than 3 patients discontinue Sorafenib treatment who experience dose-limiting toxicity after necessary dose modification and delay and/or radiation-induced liver disease in the first 15 enrolled patients, the study will recruit second fifteen patients for further evaluating safety and efficacy of treatment. Hypothesis of the current study is that Sorafenib as a maintenance therapy after combined therapy of 3DCRT/IMRT and TACE is safe and superior to radiotherapy combined with TACE alone in terms of time to progression (TTP, progression-free survival (PFS and overall survival (OS in comparison to historical data. Discussion A recent meta-analysis showed TACE in combination with radiotherapy, improved the survival and the tumor response of patients, and was

  4. The relationship between working memory and cerebral white matter volume in survivors of childhood brain tumors treated with conformal radiation therapy.

    Science.gov (United States)

    Jacola, Lisa M; Ashford, Jason M; Reddick, Wilburn E; Glass, John O; Ogg, Robert J; Merchant, Thomas E; Conklin, Heather M

    2014-08-01

    Survivors of childhood brain tumors (BTs) treated with CNS-directed therapy show changes in cerebral white matter that are related to neurocognitive late effects. We examined the association between white matter volume and working memory ability in survivors treated with conformal radiation therapy (CRT). Fifty survivors (25 males, age at assessment = 13.14 ± 2.88, age at CRT = 7.41 ± 3.41 years) completed Digit Span from the Wechsler Intelligence Scales for Children, 4th Edition and experimental Self-Ordered Search (SOS) tasks as measures of working memory. Caregiver ratings were obtained using the Behavior Rating Inventory of Executive Function. MRI exams were acquired on a 1.5 T scanner. Volumes of normal appearing white matter (NAWM) were quantified using a well-validated automated segmentation and classification program. Correlational analyses demonstrated that NAWM volumes were significantly larger in males and participants with tumors located in the infratentorial space. Correlations between NAWM volume and Digit Span Backward were distributed across anterior and posterior regions, with evidence for greater right hemisphere involvement (r = .32-.34, p ≤ .05). Correlations between NAWM volume with Digit Span Backward (r = .44-.52; p ≤ .05) and NAWM volume with SOS-Object Total (r = .45-.52, p ≤ .05) were of greater magnitude in females. No relationship was found between NAWM volume and caregiver report. Working memory performance in survivors of pediatric BTs treated with CRT are related to regionally specific NAWM volume. Developmental differences in cerebral myelination may explain findings of greater risk for neurocognitive late effects in female survivors. Future studies are needed to better isolate vulnerable white matter pathways, thus facilitating the development of neuroprotective interventions.

  5. Impact of Gemcitabine Chemotherapy and 3-Dimensional Conformal Radiation Therapy/5-Fluorouracil on Quality of Life of Patients Managed for Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Short, Michala [Discipline of Medical Radiation Sciences, University of Sydney, Sydney, New South Wales (Australia); Western Australia Centre for Cancer and Palliative Care/Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia (Australia); Goldstein, David [Department of Medical Oncology, Prince of Wales Hospital, Sydney, New South Wales (Australia); Halkett, Georgia [Western Australia Centre for Cancer and Palliative Care/Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia (Australia); Reece, William [Covance Asia Pacific, Sydney, New South Wales (Australia); Borg, Martin [Adelaide Radiotherapy Centre, Adelaide, South Australia (Australia); Zissiadis, Yvonne [Department of Radiation Oncology, Royal Perth Hospital, Perth, Western Australia (Australia); Kneebone, Andrew [Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Spry, Nigel, E-mail: Nigel.Spry@health.wa.gov.au [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia (Australia); Faculty of Medicine, University of Western Australia, Perth, Western Australia (Australia)

    2013-01-01

    Purpose: To report quality of life (QOL) results for patients receiving chemoradiation therapy for pancreatic cancer. Methods and Materials: Eligible patients (n=41 locally advanced, n=22 postsurgery) entered the B9E-AY-S168 study and received 1 cycle of induction gemcitabine (1000 mg/m{sup 2} weekly Multiplication-Sign 3 with 1-week break) followed by 3-dimensional conformal radiation therapy (RT) (54 Gy locally advanced and 45 Gy postsurgery) and concomitant continuous-infusion 5-fluorouracil (5FU) (200 mg/m{sup 2}/d throughout RT). After 4 weeks, patients received an additional 3 cycles of consolidation gemcitabine chemotherapy. Patients completed the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-PAN26 questionnaires at baseline, before RT/5FU, at end of RT/5FU, before consolidation gemcitabine, and at treatment completion. Results: The patterns of change in global QOL scores differed between groups. In the locally advanced group global QOL scores were +13, +8, +3, and +1 compared with baseline before RT/5FU (P=.008), at end of RT/5FU, before consolidation gemcitabine, and at treatment completion, respectively. In the postsurgery group, global QOL scores were -3, +4, +15, and +17 compared with baseline at the same time points, with a significant improvement in global QOL before consolidation gemcitabine (P=.03). No significant declines in global QOL were reported by either cohort. Conclusions: This study demonstrates that global QOL and associated function and symptom profiles for pancreatic chemoradiation therapy differ between locally advanced and postsurgery patients, likely owing to differences in underlying disease status. For both groups, the treatment protocol was well tolerated and did not have a negative impact on patients' global QOL.

  6. Late radiation side effects, cosmetic outcomes and pain in breast cancer patients after breast-conserving surgery and three-dimensional conformal radiotherapy : Risk-modifying factors.

    Science.gov (United States)

    Hille-Betz, Ursula; Vaske, Bernhard; Bremer, Michael; Soergel, Philipp; Kundu, Sudip; Klapdor, Rüdiger; Hillemanns, Peter; Henkenberens, Christoph

    2016-01-01

    The purpose of this work was to identify parameters influencing the risk of late radiation side effects, fair or poor cosmetic outcomes (COs) and pain in breast cancer patients after breast-conserving therapy (BCT) and three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2013, 159 patients were treated at the Hannover Medical School. Physician-rated toxicity according to the LENT-SOMA criteria, CO and pain were assessed by multivariate analysis. LENT-SOMA grade 1-4 toxicity was observed as follows: fibrosis 10.7 %, telangiectasia 1.2 %, arm oedema 8.8 % and breast oedema 5.0 %. In addition, 15.1 % of patients reported moderate or severe breast pain, and 21.4 % complained about moderate or severe pain in the arm or shoulder. In multivariate analysis, axillary clearing (AC) was significantly associated with lymphoedema of the arm [odds ratio (OR) 4.37, p = 0.011, 95 % confidence interval (CI) 1.4-13.58]. Breast oedema was also highly associated with AC (OR 10.59, p = 0.004, 95 % CI 2.1-53.36), a ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C (OR 5.34, p = 0.029, 95 % CI 1.2-24.12). A ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C were the parameters significantly associated with an unfavourable CO (OR 3.19, p = 0.019, 95 % CI 1.2-8.4). Concerning chronic breast pain, we found a trend related to the prescribed radiation dose including boost (OR 1.077, p = 0.060, 95 % CI 0.997-1.164). Chronic shoulder or arm pain was statistically significantly associated with lymphoedema of the arm (OR 3.9, p = 0.027, 95 % CI 1.17-13.5). Chronic arm and breast oedema were significantly influenced by the extent of surgery (AC). Ptotic and large breasts were significantly associated with unfavourable COs and chronic breast oedema. Late toxicities exclusive breast pain were not associated with radiotherapy parameters.

  7. Verification of hypo-fractionated treatments in helical tomotherapy; Verificacion de tratamientos hipofraccionados de tomoterapia helicoidal

    Energy Technology Data Exchange (ETDEWEB)

    Pinto Monedero, M.; Rodriguez Romero, R.; Sanchez Rubio, P.

    2013-07-01

    The objective of this work consists of evaluating the representativeness of rescaled dose checks and study the feasibility of the use of the green channel of the EBT2 films to verify treatment dose fraction exceeding 8 Gy, thus avoiding the need to of rescaling. (Author)

  8. Modelling the correlation between EGFr expression and tumour cell radiosensitivity, and combined treatments of radiation and monoclonal antibody EGFr inhibitors

    Directory of Open Access Journals (Sweden)

    Pedicini Piernicola

    2012-06-01

    Full Text Available Abstract Purpose To estimate the effects of heterogeneity on tumour cell sensitivity to radiotherapy combined with radiosensitizing agents attributable to differences in expression levels of Epidermal Growth Factor Receptor (EGFr. Materials and methods Differences in radiosensitivity are not limited to cells of different cancer histotypes but also occur within the same cancer, or appear during radiotherapy if radiosensitizing drugs are combined with ionizing radiation. A modified biologically effective dose (MBED, has been introduced to account for changes in radiosensitivity parameters (α and α/β rather than changes in dose/fraction or total dose as normally done with standard biologically effective dose (BED. The MBED approach was applied to cases of EGFr over-expression and cases where EGFr inhibitors were combined with radiation. Representative examples in clinical practice were considered. Results Assuming membrane EGFr over-expression corresponds to reduced radiosensitivity (αH = 0.15 Gy-1 and αH/βH = 7.5 Gy relative to normal radiosensitivity (α = 0.2 Gy-1 and α/β = 10 Gy, an increased dose per fraction of 2.42 Gy was obtained through the application of MBED, which is equivalent to the effect of a reference schedule with 30 fractions of 2 Gy. An equivalent hypo-fractionated regime with a dose per fraction of 2.80 Gy is obtained if 25 fractions are set. Dose fractionations modulated according to drug pharmacokinetics are estimated for combined treatments with biological drugs. Soft and strong modulated equivalent hypo-fractionations result from subtraction of 5 or 10 fractions, respectively. Conclusions During this computational study, a new radiobiological tool has been introduced. The MBED allows the required dose per fraction to be estimated when tumour radiosensitivity is reduced because EGFr is over-expressed. If radiotherapy treatment is combined with EGFr inhibitors, MBED suggests new treatment strategies

  9. Radiobiological mechanisms of stereotactic body radiation therapy and stereotactic radiation surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Kim, Won Woo; Park, In Hwan; Kim, Hee Jong; Lee, Eun Jin; Jung, Jae Hoon [Research Center for Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Cho, Lawrence Chin Soo; Song, Chang W. [Dept. of Radiation Oncology, University of Minnesota Medical School, Minneapolis (United States)

    2015-12-15

    Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.

  10. Late radiation side effects, cosmetic outcomes and pain in breast cancer patients after breast-conserving surgery and three-dimensional conformal radiotherapy. Risk-modifying factors

    Energy Technology Data Exchange (ETDEWEB)

    Hille-Betz, Ursula; Soergel, Philipp; Kundu, Sudip; Klapdor, Ruediger; Hillemanns, Peter [Hannover Medical School, Department of Obstetrics and Gynaecology, Hannover (Germany); Vaske, Bernhard [Hannover Medical School, Institute of Medical Biometry and Informatics, Hannover (Germany); Bremer, Michael; Henkenberens, Christoph [Hannover Medical School, Department of Radiation Oncology and Special Oncology, Hannover (Germany)

    2016-01-15

    The purpose of this work was to identify parameters influencing the risk of late radiation side effects, fair or poor cosmetic outcomes (COs) and pain in breast cancer patients after breast-conserving therapy (BCT) and three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2013, 159 patients were treated at the Hannover Medical School. Physician-rated toxicity according to the LENT-SOMA criteria, CO and pain were assessed by multivariate analysis. LENT-SOMA grade 1-4 toxicity was observed as follows: fibrosis 10.7 %, telangiectasia 1.2 %, arm oedema 8.8 % and breast oedema 5.0 %. In addition, 15.1 % of patients reported moderate or severe breast pain, and 21.4 % complained about moderate or severe pain in the arm or shoulder. In multivariate analysis, axillary clearing (AC) was significantly associated with lymphoedema of the arm [odds ratio (OR) 4.37, p = 0.011, 95 % confidence interval (CI) 1.4-13.58]. Breast oedema was also highly associated with AC (OR 10.59, p = 0.004, 95 % CI 2.1-53.36), a ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C (OR 5.34, p = 0.029, 95 % CI 1.2-24.12). A ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C were the parameters significantly associated with an unfavourable CO (OR 3.19, p = 0.019, 95 % CI 1.2-8.4). Concerning chronic breast pain, we found a trend related to the prescribed radiation dose including boost (OR 1.077, p = 0.060, 95 % CI 0.997-1.164). Chronic shoulder or arm pain was statistically significantly associated with lymphoedema of the arm (OR 3.9, p = 0.027, 95 % CI 1.17-13.5). Chronic arm and breast oedema were significantly influenced by the extent of surgery (AC). Ptotic and large breasts were significantly associated with unfavourable COs and chronic breast oedema. Late toxicities exclusive breast pain were not associated with radiotherapy parameters. (orig.) [German] Ziel dieser Arbeit war es, Parameter zu identifizieren, die Spaetschaeden nach Radiotherapie, ein unguenstiges

  11. Non-conformable, partial and conformable transposition

    DEFF Research Database (Denmark)

    König, Thomas; Mäder, Lars Kai

    2013-01-01

    Although member states are obliged to transpose directives into domestic law in a conformable manner and receive considerable time for their transposition activities, we identify three levels of transposition outcomes for EU directives: conformable, partially conformable and non-conformable...... and the Commission regarding a directive’s outcome, play a much more strategic role than has to date acknowledged in the transposition literature. Whereas disagreement of a member state delays conformable transposition, it speeds up non-conformable transposition. Disagreement of the Commission only prolongs...

  12. Comparison study of the partial-breast irradiation techniques: Dosimetric analysis of three-dimensional conformal radiation therapy, electron beam therapy, and helical tomotherapy depending on various tumor locations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Joo; Park, So-Hyun [Department of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Son, Seok-Hyun; Cheon, Keum-Seong; Choi, Byung-Ock [Department of Radiation Oncology, Seoul St. Mary’s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of); Suh, Tae-Suk, E-mail: suhsanta@catholic.ac.kr [Department of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of)

    2013-10-01

    The partial-breast irradiation (PBI) technique, an alternative to whole-breast irradiation, is a beam delivery method that uses a limited range of treatment volume. The present study was designed to determine the optimal PBI treatment modalities for 8 different tumor locations. Treatment planning was performed on computed tomography (CT) data sets of 6 patients who had received lumpectomy treatments. Tumor locations were classified into 8 subsections according to breast quadrant and depth. Three-dimensional conformal radiation therapy (3D-CRT), electron beam therapy (ET), and helical tomotherapy (H-TOMO) were utilized to evaluate the dosimetric effect for each tumor location. Conformation number (CN), radical dose homogeneity index (rDHI), and dose delivered to healthy tissue were estimated. The Kruskal-Wallis, Mann-Whitney U, and Bonferroni tests were used for statistical analysis. The ET approach showed good sparing effects and acceptable target coverage for the lower inner quadrant—superficial (LIQ-S) and lower inner quadrant—deep (LIQ-D) locations. The H-TOMO method was the least effective technique as no evaluation index achieved superiority for all tumor locations except CN. The ET method is advisable for treating LIQ-S and LIQ-D tumors, as opposed to 3D-CRT or H-TOMO, because of acceptable target coverage and much lower dose applied to surrounding tissue.

  13. Three dimensional conformal postoperative radiotherapy for ...

    African Journals Online (AJOL)

    Azza Helal

    2013-06-17

    Jun 17, 2013 ... Abbreviations: 3DCRT, three dimensional conformal radiotherapy;. OARs, organs at risk; DVPs, dose volume parameters; PTV, planning target volume; RT, radiation therapy; ACOD, Alexandria Clinical. Oncology Department; CT, computed tomography; ICRU, Interna- tional Commission on Radiation Units; ...

  14. Impact on quality of life of IMRT versus 3-D conformal radiation therapy in head and neck cancer patients: A case control study

    Directory of Open Access Journals (Sweden)

    Edvard Abel, MD

    2017-07-01

    Conclusions: This study further supports the hypothesis that the introduction of IMRT has improved the long-term quality of life of HN cancer patients who have been treated with radiation therapy, but might cause more acute side effects. Longer follow-up is needed to study late complications.

  15. Late Toxicity and Patient Self-Assessment of Breast Appearance/Satisfaction on RTOG 0319: A Phase 2 Trial of 3-Dimensional Conformal Radiation Therapy-Accelerated Partial Breast Irradiation Following Lumpectomy for Stages I and II Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chafe, Susan, E-mail: susan.chafe@albertahealthservices.ca [Department of Radiation Oncology, Cross Cancer Institute-University of Alberta, Edmonton, Alberta (Canada); Moughan, Jennifer [Department of Radiation Oncology, RTOG Statistical Center, Philadelphia, Pennsylvania (United States); McCormick, Beryl [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); Pass, Helen [Womens' Breast Center, Stamford Hospital, Stamford, Connecticut (United States); Rabinovitch, Rachel [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Arthur, Douglas W. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Petersen, Ivy [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); White, Julia [Department of Radiation Oncology, Ohio State University, Columbus, Ohio (United States); Vicini, Frank A. [Michigan Healthcare Professionals/21st Century Oncology, Farmington Hills, Michigan (United States)

    2013-08-01

    Purpose: Late toxicities and cosmetic analyses of patients treated with accelerated partial breast irradiation (APBI) on RTOG 0319 are presented. Methods and Materials: Patients with stages I to II breast cancer ≤3 cm, negative margins, and ≤3 positive nodes were eligible. Patients received three-dimensional conformal external beam radiation therapy (3D-CRT; 38.5 Gy in 10 fractions twice daily over 5 days). Toxicity and cosmesis were assessed by the patient (P), the radiation oncologist (RO), and the surgical oncologist (SO) at 3, 6, and 12 months from the completion of treatment and then annually. National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to grade toxicity. Results: Fifty-two patients were evaluable. Median follow-up was 5.3 years (range, 1.7-6.4 years). Eighty-two percent of patients rated their cosmesis as good/excellent at 1 year, with rates of 64% at 3 years. At 3 years, 31 patients were satisfied with the treatment, 5 were not satisfied but would choose 3D-CRT again, and none would choose standard radiation therapy. The worst adverse event (AE) per patient reported as definitely, probably, or possibly related to radiation therapy was 36.5% grade 1, 50% grade 2, and 5.8% grade 3 events. Grade 3 AEs were all skin or musculoskeletal-related. Treatment-related factors were evaluated to potentially establish an association with observed toxicity. Surgical bed volume, target volume, the number of beams used, and the use of bolus were not associated with late cosmesis. Conclusions: Most patients enrolled in RTOG 0319 were satisfied with their treatment, and all would choose to have the 3D-CRT APBI again.

  16. On conformally related -waves

    Indian Academy of Sciences (India)

    Conformal transformations; conformal Killing vectors; -waves. Abstract. Brinkmann [1] has shown that conformally related distinct Ricci flat solutions are -waves. Brinkmann's result has been generalized to include the conformally invariant source terms. It has been shown that [4] if g i k and g ¯ i k ( = − 2 g i k , : a ...

  17. Proton Beam Therapy Versus Conformal Photon Radiation Therapy for Childhood Craniopharyngioma: Multi-institutional Analysis of Outcomes, Cyst Dynamics, and Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Andrew J. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Greenfield, Brad [Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas (United States); Mahajan, Anita [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Paulino, Arnold C. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas (United States); Okcu, M. Fatih [Department of Pediatrics, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Chintagumpala, Murali [Department of Pediatrics, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Kahalley, Lisa S. [Section of Psychology, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); McAleer, Mary F.; McGovern, Susan L. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Whitehead, William E. [Department of Neurosurgery, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States)

    2014-10-01

    Purpose: We compared proton beam therapy (PBT) with intensity modulated radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease control, cyst dynamics, and toxicity. Methods and Materials: We reviewed records from 52 children treated with PBT (n=21) or IMRT (n=31) at 2 institutions from 1996-2012. Endpoints were overall survival (OS), disease control, cyst dynamics, and toxicity. Results: At 59.6 months' median follow-up (PBT 33 mo vs IMRT 106 mo; P<.001), the 3-year outcomes were 96% for OS, 95% for nodular failure-free survival and 76% for cystic failure-free survival. Neither OS nor disease control differed between treatment groups (OS P=.742; nodular failure-free survival P=.546; cystic failure-free survival P=.994). During therapy, 40% of patients had cyst growth (20% requiring intervention); immediately after therapy, 17 patients (33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs 19% PBT; P=.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT; P=.353), with intervention required in 40%. Toxicity did not differ between groups. On multivariate analysis, cyst growth was related to visual and hypothalamic toxicity (P=.009 and .04, respectively). Patients given radiation as salvage therapy (for recurrence) rather than adjuvant therapy had higher rates of visual and endocrine (P=.017 and .024, respectively) dysfunction. Conclusions: Survival and disease-control outcomes were equivalent for PBT and IMRT. Cyst growth is common, unpredictable, and should be followed during and after therapy, because it contributes to late toxicity. Delaying radiation therapy until recurrence may result in worse visual and endocrine function.

  18. Predictors of High-grade Esophagitis After Definitive Three-dimensional Conformal Therapy, Intensity-modulated Radiation Therapy, or Proton Beam Therapy for Non-small cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Daniel R., E-mail: dgomez@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Martel, Mary K.; Mohan, Radhe; Balter, Peter A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lopez Guerra, Jose Luis [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Hospitales Universitarios Virgen del Rocio, Seville (Spain); Liu Hongmei; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-11-15

    Introduction: We analyzed the ability of various patient- and treatment-related factors to predict radiation-induced esophagitis (RE) in patients with non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or proton beam therapy (PBT). Methods and Materials: Patients were treated for NSCLC with 3D-CRT, IMRT, or PBT at MD Anderson from 2000 to 2008 and had full dose-volume histogram (DVH) data available. The endpoint was severe (grade {>=}3) RE. The Lyman-Kutcher-Burman (LKB) model was used to analyze RE as a function of the fractional esophageal DVH, with clinical variables included as dose-modifying factors. Results: Overall, 652 patients were included: 405 patients were treated with 3D-CRT, 139 with IMRT, and 108 with PBT; corresponding rates of grade {>=}3 RE were 8%, 28%, and 6%, respectively, with a median time to onset of 42 days (range, 11-93 days). A fit of the fractional DVH LKB model demonstrated that the fractional effective dose was significantly different (P=.046) than 1 (fractional mean dose) indicating that high doses to small volumes are more predictive than mean esophageal dose. The model fit was better for 3D-CRT and PBT than for IMRT. Including receipt of concurrent chemotherapy as a dose-modifying factor significantly improved the LKB model (P=.005), and the model was further improved by including a variable representing treatment with >30 fractions. Examining individual types of chemotherapy agents revealed a trend toward receipt of concurrent taxanes and increased risk of RE (P=.105). Conclusions: Fractional dose (dose rate) and number of fractions (total dose) distinctly affect the risk of severe RE, estimated using the LKB model, and concurrent chemotherapy improves the model fit. This risk of severe RE is underestimated by this model in patients receiving IMRT.

  19. Radiation-induced Liver Injury after 3D-conformal Radiotherapy for Hepatocellular Carcinoma: Quantitative Assessment Using Gd-EOB-DTPA-enhanced MRI.

    Science.gov (United States)

    Fukugawa, Yoshiyuki; Namimoto, Tomohiro; Toya, Ryo; Saito, Tetsuo; Yuki, Hideaki; Matsuyama, Tomohiko; Ikeda, Osamu; Yamashita, Yasuyuki; Oya, Natsuo

    2017-02-01

    Focal liver reaction (FLR) appears in the hepatobiliary-phase images of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) following radiotherapy (RT). We investigated the threshold dose (TD) for FLR development in 13 patients with hepatocellular carcinoma (HCC) who underwent three-dimensional conformal radiotherapy (3D-CRT) with 45 Gy in 15 fractions. FLR volumes (FLRVs) were calculated based on planning CT images by referring to fused hepatobiliary- phase images. We also calculated the TD and the irradiated volumes (IVs) of the liver parenchyma at a given dose of every 5 Gy (IVdose) based on a dose-volume histogram (DVH). The median TD was 35.2 Gy. The median IV20, IV25, IV30, IV35, IV40, and IV45 values were 371.1, 274.8, 233.4, 188.6, 145.8, and 31.0 ml, respectively. The median FLRV was 144.9 ml. There was a significant difference between the FLRV and IV20, IV25, and IV45 (p<0.05), but no significant differences between the FLRV and IV30, IV35, or IV40. These results suggest that the threshold dose of the FLR is approx. 35 Gy in HCC patients who undergo 3D-CRT in 15 fractions. The percentage of the whole liver volume receiving a dose of more than 30-40 Gy (V30-40) is a potential candidate optimal DVH parameter for this fractionation schedule.

  20. Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

    Energy Technology Data Exchange (ETDEWEB)

    De Wagter, C. [ed.

    1995-12-01

    The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions.

  1. Viscous conformal gauge theories

    DEFF Research Database (Denmark)

    Toniato, Arianna; Sannino, Francesco; Rischke, Dirk H.

    2017-01-01

    We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories.......We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories....

  2. Superspace conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  3. Conformational effects in photoelectron circular dichroism

    Science.gov (United States)

    Turchini, S.

    2017-12-01

    Photoelectron circular dichroism (PECD) is a novel type of spectroscopy, which presents surprising sensitivity to conformational effects in chiral systems. While classical photoelectron spectroscopy mainly responds to conformational effects in terms of energy level shifts, PECD provides a rich and detailed response to tiny changes in electronic and structural properties by means of the intensity dispersion of the circular dichroism as a function of photoelectron kinetic energy. In this work, the basics of PECD will be outlined, emphasizing the role of interference from the l,l+/- 1 outgoing partial wave of the photoelectron in the PECD transition matrix element, which is responsible for the extreme sensitivity to conformational effects. Examples using molecular systems and interfaces will shed light on the powerful application of PECD to classical conformational effects such as group substitution, isomerism, conformer population and clustering. Moreover, the PECD results will be reported in challenging new fields where conformations play a key role, such as vibrational effects, transient chirality and time- resolved experiments. To date, PECD has mostly been based on synchrotron radiation facilities, but it also has a future as a table-top lab experiment by means of multiphoton ionization. An important application of PECD as an analytical tool will be reported. The aim of this review is to illustrate that in PECD, the presence of conformational effects is essential for understanding a wide range of effects from a new perspective, making it different from classical spectroscopy.

  4. Intensity-modulated radiation therapy and xerostomia

    National Research Council Canada - National Science Library

    Chambers, Mark S; Weber, Randal S; Garden, Adam S

    2006-01-01

    Conformal radiation with intensity-modulated radiation therapy, IMRT, is a radiation technique that potentially can minimize the dose to salivary glands and thereby decrease the incidence of xerostomia...

  5. Design of conformal lens by drilling holes materials using quasi-conformal transformation optics.

    Science.gov (United States)

    Li, Shouliang; Zhang, Zhan; Wang, Junhong; He, Xianshi

    2014-10-20

    In this paper, based on quasi-conformal transformation optics, a 3D conformal lens made of isotropic and non-resonant metamaterial is designed, which can make a cylindrical conformal array behave similarly to a uniform linear array. After discussion and simplification in the two-dimensional model, we realize the proposed lens by utilizing drilling-hole material in the three-dimensional structure. The ring-like shape and forward-only radiation make it possible to equip the lens on a cylindrical device.

  6. Conformal Carroll groups

    OpenAIRE

    Duval, C.; Gibbons, G W; Horvathy, P. A.

    2014-01-01

    Conformal extensions of Levy-Leblond's Carroll group, based on geometric properties analogous to those of Newton-Cartan space-time are proposed. The extensions are labelled by an integer $k$. This framework includes and extends our recent study of the Bondi-Metzner-Sachs (BMS) and Newman-Unti (NU) groups. The relation to Conformal Galilei groups is clarified. Conformal Carroll symmetry is illustrated by "Carrollian photons". Motion both in the Newton-Cartan and Carroll spaces may be related t...

  7. Conformational stability of calreticulin

    DEFF Research Database (Denmark)

    Jørgensen, Charlotte S; Trandum, Christa; Larsen, Nanna Brink

    2005-01-01

    The conformational stability of calreticulin was investigated. Apparent unfolding temperatures (Tm) increased from 31 degrees C at pH 5 to 51 degrees C at pH 9, but electrophoretic analysis revealed that calreticulin oligomerized instead of unfolding. Structural analyses showed that the single C......-terminal alpha-helix was of major importance to the conformational stability of calreticulin....

  8. Conformational stability of calreticulin

    DEFF Research Database (Denmark)

    Jørgensen, C.S.; Trandum, C.; Larsen, N.

    2005-01-01

    The conformational stability of calreticulin was investigated. Apparent unfolding temperatures (T-m) increased from 31 degrees C at pH 5 to 51 degrees C at pH 9, but electrophoretic analysis revealed that calreticulin oligomerized instead of unfolding. Structural analyses showed that the single C......-terminal a-helix was of major importance to the conformational stability of calreticulin....

  9. Conformal expansions and renormalons

    CERN Document Server

    Brodsky, S J; Grunberg, G; Rathsman, J; Brodsky, Stanley J.; Gardi, Einan; Grunberg, Georges; Rathsman, Johan

    2001-01-01

    The coefficients in perturbative expansions in gauge theories are factoriallyincreasing, predominantly due to renormalons. This type of factorial increaseis not expected in conformal theories. In QCD conformal relations betweenobservables can be defined in the presence of a perturbative infraredfixed-point. Using the Banks-Zaks expansion we study the effect of thelarge-order behavior of the perturbative series on the conformal coefficients.We find that in general these coefficients become factorially increasing.However, when the factorial behavior genuinely originates in a renormalonintegral, as implied by a postulated skeleton expansion, it does not affect theconformal coefficients. As a consequence, the conformal coefficients willindeed be free of renormalon divergence, in accordance with previousobservations concerning the smallness of these coefficients for specificobservables. We further show that the correspondence of the BLM method with theskeleton expansion implies a unique scale-setting procedure. Th...

  10. Conformal expansions and renormalons

    CERN Document Server

    Gardi, E; Gardi, Einan; Grunberg, Georges

    2001-01-01

    The large-order behaviour of QCD is dominated by renormalons. On the other hand renormalons do not occur in conformal theories, such as the one describing the infrared fixed-point of QCD at small beta_0 (the Banks--Zaks limit). Since the fixed-point has a perturbative realization, all-order perturbative relations exist between the conformal coefficients, which are renormalon-free, and the standard perturbative coefficients, which contain renormalons. Therefore, an explicit cancellation of renormalons should occur in these relations. The absence of renormalons in the conformal limit can thus be seen as a constraint on the structure of the QCD perturbative expansion. We show that the conformal constraint is non-trivial: a generic model for the large-order behaviour violates it. We also analyse a specific example, based on a renormalon-type integral over the two-loop running-coupling, where the required cancellation does occur.

  11. Group Size and Conformity

    OpenAIRE

    Bond, Rod

    2005-01-01

    Abstract This paper reviews theory and research on the relationship between group size and conformity and presents a meta-analysis of 125 Asch-type conformity studies. It questions the assumption of a single function made in formal models of social influence and proposes instead that the function will vary depending on which social influence process predominates. It is argued that normative influence is lik...

  12. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  13. Quantum massive conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    Faria, F.F. [Universidade Estadual do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil)

    2016-04-15

    We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard first order canonical quantization method. It is shown that quantum massive conformal gravity is renormalizable but has ghost states. A possible decoupling of these ghost states at high energies is discussed. (orig.)

  14. Delineating the conformal window

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Pickup, Thomas; Teper, Michael

    2011-01-01

    We identify and characterise the conformal window in gauge theories relevant for beyond the standard model building, e.g. Technicolour, using the criteria of metric confinement and causal analytic couplings, which are known to be consistent with the phase diagram of supersymmetric QCD from Seiberg...... duality. Using these criteria we find perturbation theory to be consistent throughout the predicted conformal window for several of these gauge theories and we discuss recent lattice results in the light of our findings....

  15. Conformal invariance of curvature perturbation

    CERN Document Server

    Gong, Jinn-Ouk; Park, Wan Il; Sasaki, Misao; Song, Yong-Seon

    2011-01-01

    We show that in the single component situation all perturbation variables in the comoving gauge are conformally invariant to all perturbation orders. Generally we identify a special time slicing, the uniform-conformal transformation slicing, where all perturbations are again conformally invariant to all perturbation orders. We apply this result to the delta N formalism, and show its conformal invariance.

  16. Conformal invariance of curvature perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jinn-Ouk [Theory Division, CERN, CH-1211 Genève 23 (Switzerland); Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Park, Wan Il; Sasaki, Misao; Song, Yong-Seon, E-mail: jinn-ouk.gong@cern.ch, E-mail: jchan@knu.ac.kr, E-mail: wipark@kias.re.kr, E-mail: misao@yukawa.kyoto-u.ac.jp, E-mail: ysong@kias.re.kr [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)

    2011-09-01

    We show that in the single component situation all perturbation variables in the comoving gauge are conformally invariant to all perturbation orders. Generally we identify a special time slicing, the uniform-conformal transformation slicing, where all perturbations are again conformally invariant to all perturbation orders. We apply this result to the δN formalism, and show its conformal invariance.

  17. Normal tissue tolerance to external beam radiation therapy: Spinal cord; Tolerance a l'irradiation des tissus sains: moelle epiniere

    Energy Technology Data Exchange (ETDEWEB)

    Habrand, J.L. [Departement de radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France); Centre de protontherapie, institut Curie, 91 - Orsay (France); Drouet, F. [Departement de radiotherapie, centre Rene-Gauducheau, 44 - Nantes (France)

    2010-07-15

    Radiation myelopathy is one of the most dreadful complications of radiation therapy. Despite multiple animal experiments and human autopsic series, its pathogenesis remains largely unknown. In most instances, the classical aspect of myelomalacia combines glial and vascular injuries in various sequences. Recent studies point out the role of oligo-dendrocytes and their precursors, as well as of intercellular mediators (cytokines and stress molecules). The clinical presentation comprises a spectrum of non specific neurological symptoms whose evolution is sometimes regressive but more commonly progressive and life-threatening. Usually, it occurs following a latent period of six months to two years after irradiation of the cervical, thoracic or upper lumbar spine to a dose in excess of 50 Gy, conventionally fractionated. Nonetheless, these typical features can be altered by extrinsic factors, such as hypo fractionation/acceleration of the dose, multiple surgical procedures, chemotherapy especially mega therapy, or neurotoxic drugs. Conversely, hyperfractionated regimens that take into account protracted half-time repair of sublethal damages to the CNS, as well as sophisticated estimates of the dose to the cord and QA programs during the treatment course minimize such risks. (authors)

  18. Hot Conformal Gauge Theories

    DEFF Research Database (Denmark)

    Mojaza, Matin; Pica, Claudio; Sannino, Francesco

    2010-01-01

    in such a way that the theory develops a perturbative stable infrared fixed point at zero temperature. Due to large distance conformality we trade the coupling constant with its fixed point value and define a reduced free energy which depends only on the number of flavors, colors and matter representation. We...... show that the reduced free energy changes sign, at the second, fifth and sixth order in the coupling, when decreasing the number of flavors from the upper end of the conformal window. If the change in sign is interpreted as signal of an instability of the system then we infer a critical number...... of flavors. Surprisingly this number, if computed to the order g^2, agrees with previous predictions for the lower boundary of the conformal window for nonsupersymmetric gauge theories. The higher order results tend to predict a higher number of critical flavors. These are universal properties, i...

  19. Galilean conformal and superconformal symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Lukierski, J., E-mail: lukier@ift.uni.wroc.pl [University of Wroclaw, Institute for Theoretical Physics (Poland)

    2012-10-15

    Firstly we discuss briefly three different algebras named as nonrelativistic (NR) conformal: Schroedinger, Galilean conformal, and infinite algebra of local NR conformal isometries. Further we shall consider in some detail Galilean conformal algebra (GCA) obtained in the limit c{yields}{infinity} from relativistic conformal algebraO(d+1, 2) (d-number of space dimensions). Two different contraction limits providing GCA and some recently considered realizations will be briefly discussed. Finally by considering NR contraction of D = 4 superconformal algebra the Galilei conformal superalgebra (GCSA) is obtained, in the formulation using complexWeyl supercharges.

  20. Transportation Conformity Training and Presentations

    Science.gov (United States)

    EPA's OTAQ has provided multiple conformity training sessions in the past to assist state and local governments in implementing conformity requirements. As training information is prepared for other venues, it will be posted on this page.

  1. Dynamical spacetimes in conformal gravity

    National Research Council Canada - National Science Library

    Hongsheng Zhang; Yi Zhang; Xin-Zhou Li

    2017-01-01

    The conformal gravity remarkably boosts our prehension of gravity theories. We find a series of dynamical solutions in the W2-conformal gravity, including generalized Schwarzschild–Friedmann–Robertson–Walker (GSFRW...

  2. Multiscale conformal pattern transfer

    Science.gov (United States)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  3. Multiscale conformal pattern transfer.

    Science.gov (United States)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-22

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  4. Conformal boundaries of warped products

    DEFF Research Database (Denmark)

    Kokkendorff, Simon Lyngby

    2006-01-01

    In this note we prove a result on how to determine the conformal boundary of a type of warped product of two length spaces in terms of the individual conformal boundaries. In the situation, that we treat, the warping and conformal distortion functions are functions of distance to a base point....... The result is applied to produce examples of CAT(0)-spaces, where the conformal and ideal boundaries differ in interesting ways....

  5. Conformal block study and bounding OPE in conformal field theories

    CERN Document Server

    Yvernay, Pierre

    2015-01-01

    During the past few years, the re-emergence of conformal bootstrap as a numerical tool to solve conformal field theory allowed more precise estimation of several presumed conformal field theory among which we could cite the 3D Ising model. This work intends to provide insight on conformal blocks which are elementary objects in the conformal bootstrap approach. These are considered in Euclidian space where we study fields of all equal dimension. This study allows us to improve bounds derived in \\cite{OPEconv}.

  6. Polymer Conformation under Confinement

    Directory of Open Access Journals (Sweden)

    Stavros Bollas

    2017-02-01

    Full Text Available The conformation of polymer chains under confinement is investigated in intercalated polymer/layered silicate nanocomposites. Hydrophilic poly(ethylene oxide/sodium montmorillonite, PEO/Na+-MMT, hybrids were prepared utilizing melt intercalation with compositions where the polymer chains are mostly within the ~1 nm galleries of the inorganic material. The polymer chains are completely amorphous in all compositions even at temperatures where the bulk polymer is highly crystalline. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR is utilized to investigate the conformation of the polymer chains over a broad range of temperatures from below to much higher than the bulk polymer melting temperature. A systematic increase of the gauche conformation relatively to the trans is found with decreasing polymer content both for the C–C and the C–O bonds that exist along the PEO backbone indicating that the severe confinement and the proximity to the inorganic surfaces results in a more disordered state of the polymer.

  7. Conformal Janus on Euclidean sphere

    Energy Technology Data Exchange (ETDEWEB)

    Bak, Dongsu [Physics Department, University of Seoul,Seoul 02504 (Korea, Republic of); B.W. Lee Center for Fields, Gravity & Strings, Institute for Basic Sciences,Daejeon 34047 (Korea, Republic of); Gustavsson, Andreas [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Rey, Soo-Jong [School of Physics & Astronomy and Center for Theoretical Physics,Seoul National University,Seoul 08826 (Korea, Republic of); Center for Theoretical Physics, College of Physical Sciences, Sichuan University,Chengdu 610064 P.R. (China); B.W. Lee Center for Fields, Gravity & Strings, Institute for Basic Sciences,Daejeon 34047 (Korea, Republic of)

    2016-12-07

    We interpret Janus as an interface in a conformal field theory and study its properties. The Janus is created by an exactly marginal operator and we study its effect on the interface conformal field theory on the Janus. We do this by utilizing the AdS/CFT correspondence. We compute the interface free energy both from leading correction to the Euclidean action in the dual gravity description and from conformal perturbation theory in the conformal field theory. We find that the two results agree each other and that the interface free energy scales precisely as expected from the conformal invariance of the Janus interface.

  8. Cosmological Perturbations in Conformal Gravity

    CERN Document Server

    Mannheim, Philip D

    2011-01-01

    We present the first steps needed for an analysis of the perturbations that occur in the cosmology associated with the conformal gravity theory. We discuss the implications of conformal invariance for perturbative coordinate gauge choices, and show that in the conformal theory the trace of the metric fluctuation kinematically decouples from the first-order gravitational fluctuation equations. We determine the equations that describe first-order metric fluctuations around the illustrative conformally flat de Sitter background. Via a conformal transformation we show that such fluctuations can be constructed from fluctuations around a flat background, even though the fluctuations themselves are associated with a perturbative geometry that is not itself conformal to flat. We extend the analysis to fluctuations around other cosmologically relevant backgrounds, such as the conformally-flat Robertson-Walker background, and find tensor fluctuations that grow far more rapidly than those that occur in the analogous sta...

  9. WIZARD: AI in conformational analysis

    Science.gov (United States)

    Dolata, Daniel P.; Leach, Andrew R.; Prout, Keith

    1987-04-01

    A program which utilizes the techniques of Artificial Intelligence and Expert Systems to solve problems in the area of Conformational Analysis is described. The program searches conformational space in a systematic fashion, based on the technique known as heuristic state-space search. The program proceeds by recognizing conformational units, assigning one or more conformational templates to each unit, and joining them to form conformational suggestions. These suggestions are criticized to discover logical inconsistencies, and any resulting stresses are resolved. The resulting conformational suggestions are sometimes accurate enough for immediate use, or may be further refined by a numerical program. The latter combination is shown to be quite efficient compared to purely numerical conformational search techniques.

  10. Asians with localized prostate cancer treated with 3-dimensional conformal radiation therapy and adjuvant hormonal therapy: comparing Phoenix and American Society of Therapeutic Radiology and Oncology (ASTRO) definitions in an Asian population.

    Science.gov (United States)

    Ramalingam, Mohan; Lau, Weber; Tan, Terence; Fook, Stephanie; Ngoi, Francis; Cheng, Christopher

    2008-03-01

    Conformal radiotherapy with adjuvant androgen suppression is used in our center to treat localized prostate cancer. We compare Phoenix as an alternative to American Society of Therapeutic Radiology and Oncology (ASTRO) for defining biochemical failure. Our primary aim was to assess the Phoenix and ASTRO definitions of biochemical failure in a population of mainly Asian men with early localized prostate cancer treated with conformal radiotherapy with and without androgen ablation. We retrospectively analyzed 141 patients who were treated for T1/T2 cancer of the prostate in our center from January 1997 to June 2002 with a mean duration of follow-up of 62 months. Outcomes were analyzed by using both Phoenix and ASTRO definitions of biochemical failure as well as clinical failure. The Phoenix definition of biochemical failure was superior as measured by sensitivity, specificity, positive and negative predictive values, accuracy, and a greater concordance with clinical outcome as measured by Kappa analysis. The ASTRO definition helped to standardize reporting of biochemical failures post-radiotherapy but inadequacies have been identified especially when adjuvant hormone therapy has been given. The Phoenix definition has been noted to be a more accurate and precise description of biochemical failure in international series, and we find this to be true in our Asian population as well.

  11. Conformance and Deviance

    DEFF Research Database (Denmark)

    Gjerdrum Pedersen, Esben Rahbek; Neergaard, Peter; Thusgaard Pedersen, Janni

    2013-01-01

    This paper analyses how large Danish companies are responding to new governmental regulation which requires them to report on corporate social responsibility (CSR). The paper is based on an analysis of 142 company annual reports required by the new Danish regulation regarding CSR reporting, plus ...... in CSR reporting practices. Finally, it is argued that non-conformance with the new regulatory requirements is not solely about conscious resistance but may also be caused by, for example, lack of awareness, resource limitations, misinterpretations, and practical difficulties....

  12. Black hole evaporation in conformal gravity

    Science.gov (United States)

    Bambi, Cosimo; Modesto, Leonardo; Porey, Shiladitya; Rachwał, Lesław

    2017-09-01

    We study the formation and the evaporation of a spherically symmetric black hole in conformal gravity. From the collapse of a spherically symmetric thin shell of radiation, we find a singularity-free non-rotating black hole. This black hole has the same Hawking temperature as a Schwarzschild black hole with the same mass, and it completely evaporates either in a finite or in an infinite time, depending on the ensemble. We consider the analysis both in the canonical and in the micro-canonical statistical ensembles. Last, we discuss the corresponding Penrose diagram of this physical process.

  13. Supergravitational conformal Galileons

    Science.gov (United States)

    Deen, Rehan; Ovrut, Burt

    2017-08-01

    The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and "bouncing" cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory, but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios

  14. Unruh Effect Revisited: Poincare {theta}-Vacua as Coherent States of Conformal Zero Modes

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, M [Departamento de Matematica Aplicada, Universidad de Granada, Facultad de Ciencias, Campus de Fuentenueva, 18071 Granada (Spain); Perez-Romero, E; Aldaya, V, E-mail: calixto@ugr.es [Instituto de Astrofisica de Andalucia (IAA-CSIC), Apartado Postal 3004, 18080 Granada (Spain)

    2011-09-22

    We report on a group-theoretical revision of the Unruh effect based on the conformal group SO (4, 2), which has been developed by the authors and collaborators. Special Conformal Transformations (SCT) are interpreted as transitions to relativistic uniformly accelerated frames. Poincare invariant {theta}-vacua (which turn out to be coherent states of conformal zero modes) are destabilized by SCT and radiate as a black body.

  15. Quality of coverage: conformity measures for stereotactic radiosurgery.

    Science.gov (United States)

    Wu, Q-R Jackie; Wessels, B W; Einstein, D B; Maciunas, R J; Kim, E Y; Kinsella, T J

    2003-01-01

    In radiosurgery, conformity indices are often used to compare competing plans, evaluate treatment techniques, and assess clinical complications. Several different indices have been reported to measure the conformity of the prescription isodose to the target volume. The PITV recommended in the Radiation Therapy Oncology Group (RTOG) radiosurgery guidelines, defined as the ratio of the prescription isodose volume (PI) over the target volume (TV), is probably the most frequently quoted. However, these currently used conformity indices depend on target size and shape complexity. The objectives of this study are to systematically investigate the influence of target size and shape complexity on existing conformity indices, and to propose a different conformity index-the conformity distance index (CDI). The CDI is defined as the average distance between the target and the prescription isodose line. This study examines five case groups with volumes of 0.3, 1.0, 3.0, 10.0, and 30.0 cm(3). Each case group includes four simulated shapes: a sphere, a moderate ellipsoid, an extreme ellipsoid, and a concave "C" shape. Prescription dose coverages are generated for three simplified clinical scenarios, i.e., the PI completely covers the TV with 1 and 2 mm margins, and the PI over-covers one half of the TV with a 1 mm margin and under-covers the other half with a 1 mm margin. Existing conformity indices and the CDI are calculated for these five case groups as well as seven clinical cases. When these values are compared, the RTOG PITV conformity index and other similar conformity measures have much higher values than the CDI for smaller and more complex shapes. With the same quality of prescription dose coverage, the CDI yields a consistent conformity measure. For the seven clinical cases, we also find that the same PITV values can be associated with very different conformity qualities while the CDI predicts the conformity quality accurately. In summary, the proposed CDI provides

  16. Conformal Methods in General Relativity

    Science.gov (United States)

    Valiente Kroon, Juan A.

    2016-07-01

    List of symbols; Preface; 1. Introduction; Part I. Geometric Tools: 2. Differential Geometry; 3. Spacetime spinors; 4. Space spinors; 5. Conformal Geometry; Part II. General Relativity and Conformal Geometry: 6. Conformal extensions of exact solutions; 7. Asymptotic simplicity; 8. The conformal Einstein field equations; 9. Matter models; 10. Asymptotics; Part III. Methods of PDE Theory: 11. The conformal constraint equations; 12. Methods of the theory of hyperbolic differential equations; 13. Hyperbolic reductions; 14. Causality and the Cauchy problem in General Relativity; Part IV. Applications: 15. De Sitter-like spacetimes; 16. Minkowski-like spacetimes; 17. Anti-de Sitter-like spacetimes; 18. Characteristic problems for the conformal field equations; 19. Static solutions; 20. Spatial infinity; 21. Perspectives; References; Index.

  17. First Order Electroweak Phase Transition from (Non)Conformal Extensions of the Standard Model

    DEFF Research Database (Denmark)

    Sannino, Francesco; Virkajärvi, Jussi

    2015-01-01

    We analyse and compare the finite-temperature electroweak phase transition properties of classically (non)conformal extensions of the Standard Model. In the classically conformal scenarios the breaking of the electroweak symmetry is generated radiatively. The models feature new scalars coupled co...... the associated models are testable at the upcoming Large Hadron Collider run two experiments....

  18. Tracing conformational changes in proteins

    OpenAIRE

    Haspel, Nurit; Moll, Mark; Baker, Matthew L; Chiu, Wah; Kavraki, Lydia E.

    2010-01-01

    Background Many proteins undergo extensive conformational changes as part of their functionality. Tracing these changes is important for understanding the way these proteins function. Traditional biophysics-based conformational search methods require a large number of calculations and are hard to apply to large-scale conformational motions. Results In this work we investigate the application of a robotics-inspired method, using backbone and limited side chain representation and a coarse grain...

  19. Conformal Fermi Coordinates

    CERN Document Server

    Dai, Liang; Schmidt, Fabian

    2015-01-01

    Fermi Normal Coordinates (FNC) are a useful frame for isolating the locally observable, physical effects of a long-wavelength spacetime perturbation. Their cosmological application, however, is hampered by the fact that they are only valid on scales much smaller than the horizon. We introduce a generalization that we call Conformal Fermi Coordinates (CFC). CFC preserve all the advantages of FNC, but in addition are valid outside the horizon. They allow us to calculate the coupling of long- and short-wavelength modes on all scales larger than the sound horizon of the cosmological fluid, starting from the epoch of inflation until today, by removing the complications of the second order Einstein equations to a large extent, and eliminating all gauge ambiguities. As an application, we present a calculation of the effect of long-wavelength tensor modes on small scale density fluctuations. We recover previous results, but clarify the physical content of the individual contributions in terms of locally measurable ef...

  20. Reflections on conformal spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungrok; Kravchuk, Petr [Walter Burke Institute for Theoretical Physics, Caltech,Pasadena, California 91125 (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, New Jersey 08540 (United States); Ooguri, Hirosi [Walter Burke Institute for Theoretical Physics, Caltech,Pasadena, California 91125 (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, New Jersey 08540 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI),University of Tokyo,Kashiwa 277-8583 (Japan)

    2016-04-29

    We use modular invariance and crossing symmetry of conformal field theory to reveal approximate reflection symmetries in the spectral decompositions of the partition function in two dimensions in the limit of large central charge and of the four-point function in any dimension in the limit of large scaling dimensions Δ{sub 0} of external operators. We use these symmetries to motivate universal upper bounds on the spectrum and the operator product expansion coefficients, which we then derive by independent techniques. Some of the bounds for four-point functions are valid for finite Δ{sub 0} as well as for large Δ{sub 0}. We discuss a similar symmetry in a large spacetime dimension limit. Finally, we comment on the analogue of the Cardy formula and sparse light spectrum condition for the four-point function.

  1. Conformal (In)Equality

    Science.gov (United States)

    Hyun, Young-Hwan; Kim, Yoonbai; Lee, Seokcheon

    2018-01-01

    The current accelerating expansion of the Universe is explained either by dark energy or by modified gravity theories. Both of them can explain exactly the same background evolution of the Universe, however this degeneracy may be broken when the observation of large scale structure formation is taken into account. Two observables are parameterized by the so-called dark energy equation of state, ω and the growth index parameter, γ. From these observed parameters, one may reconstruct the model parameters of the so-called scalar-tensor gravity theory, one of the modified gravity theories. Especially, the scalar-tensor gravity theory is described both in Jordan frame and in Einstein frame. If cosmological observations are interpreted in one frame, then all of the observables should also be interpreted in that frame. This explicitly shows conformal inequality of cosmological observables.

  2. Conformal (InEquality

    Directory of Open Access Journals (Sweden)

    Hyun Young-Hwan

    2018-01-01

    Full Text Available The current accelerating expansion of the Universe is explained either by dark energy or by modified gravity theories. Both of them can explain exactly the same background evolution of the Universe, however this degeneracy may be broken when the observation of large scale structure formation is taken into account. Two observables are parameterized by the so-called dark energy equation of state, ω and the growth index parameter, γ. From these observed parameters, one may reconstruct the model parameters of the so-called scalar-tensor gravity theory, one of the modified gravity theories. Especially, the scalar-tensor gravity theory is described both in Jordan frame and in Einstein frame. If cosmological observations are interpreted in one frame, then all of the observables should also be interpreted in that frame. This explicitly shows conformal inequality of cosmological observables.

  3. Reflections on Conformal Spectra

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    We use modular invariance and crossing symmetry of conformal field theory to reveal approximate reflection symmetries in the spectral decompositions of the partition function in two dimensions in the limit of large central charge and of the four-point function in any dimension in the limit of large scaling dimensions Δ0 of external operators. We use these symmetries to motivate universal upper bounds on the spectrum and the operator product expansion coefficients, which we then derive by independent techniques. Some of the bounds for four-point functions are valid for finite Δ0 as well as for large Δ0. We discuss a similar symmetry in a large spacetime dimension limit. Finally, we comment on the analogue of the Cardy formula and sparse light spectrum condition for the four-point function. (based on 1510.08772 with Kim & Ooguri). This seminar will be given via videolink

  4. Replacement between conformity and counter-conformity in consumption decisions.

    Science.gov (United States)

    Chou, Ting-Jui; Chang, En-Chung; Dai, Qi; Wong, Veronica

    2013-02-01

    This study assessed, in a Chinese context, how self-esteem interacts with perceived similarity and uniqueness to yield cognitive dissonance, and whether the dissonance leads to self-reported conformity or counter-conformity behavior. Participants were 408 respondents from 4 major Chinese cities (M age = 33.0 yr., SD = 4.3; 48% men). Self-perceptions of uniqueness, similarity, cognitive dissonance, self-esteem and need to behave in conformity or counter-conformity were measured. A theoretical model was assessed in four situations, relating the ratings of self-esteem and perceived similarity/uniqueness to the way other people at a wedding were dressed, and the resultant cognitive dissonance and conformity/ counter-conformity behavior. Regardless of high or low self-esteem, all participants reported cognitive dissonance when they were told that they were dressed extremely similarly to or extremely differently from the other people attending the wedding. However, the conforming/counter-conforming strategies used by participants to resolve the cognitive dissonance differed. When encountering dissonance induced by the perceived extreme uniqueness of dress, participants with low self-esteem tended to say they would dress next time so as to conform with the way others were dressed, while those with high self-esteem indicated they would continue their counter-conformity in attire. When encountering dissonance induced by the perceived extreme similarity to others, both those with high and low self-esteem tended to say they would dress in an unorthodox manner to surprise other people in the future.

  5. Recent advancements in conformal gravity

    Science.gov (United States)

    O'Brien, James G.; Chaykov, Spasen S.; Dentico, Jeremy; Stulge, Modestas; Stefanski, Brian; Moss, Robert J.

    2017-05-01

    In recent years, due to the lack of direct observed evidence of cold dark matter, coupled with the shrinking parameter space to search for new dark matter particles, there has been increased interest in Alternative Gravitational theories. This paper, addresses three recent advances in conformal gravity, a fourth order renormalizable metric theory of gravitation originally formulated by Weyl, and later advanced by Mannheim and Kazanas. The first section of the paper applies conformal gravity to the rotation curves of the LITTLE THINGS survey, extending the total number of rotation curves successfully fit by conformal gravity to well over 200 individual data sets without the need for additional dark matter. Further, in this rotation curve study, we show how MOND and conformal gravity compare for each galaxy in the sample. Second, we look at the original Zwicky problem of applying the virial theorem to the Coma cluster in order to get an estimate for the cluster mass. However, instead of using the standard Newtonian potential, here we use the weak field approximation of conformal gravity. We show that in the conformal case we can get a much smaller mass estimate and thus there is no apparent need to include dark matter. We then show that this calculation is in agreement with the observational data from other well studied clusters. Last, we explore the calculation of the deflection of starlight through conformal gravity, as a first step towards applying conformal gravity to gravitaitonal lensing.

  6. Solvent Induced Conformational Kinetics (SICK)

    NARCIS (Netherlands)

    Jonkman, Leffert; Kommandeur, Jan

    1970-01-01

    Specific conformations of molecules may be induced by the solvent when a large free volume is associated with the oonformational change. The conformational energy barrier is then a property of the solvent, rather than of the molecule. Such effects are reported for several substituted

  7. Counselor Identity: Conformity or Distinction?

    Science.gov (United States)

    McLaughlin, Jerry E.; Boettcher, Kathryn

    2009-01-01

    The authors explore 3 debates in other disciplines similar to counseling's identity debate in order to learn about common themes and outcomes. Conformity, distinction, and cohesion emerged as common themes. They conclude that counselors should retain their distinctive, humanistic approach rather than conforming to the dominant, medical approach.

  8. Dosimetric Coverage of the External Anal Sphincter by 3-Dimensional Conformal Fields in Rectal Cancer Patients Receiving Neoadjuvant Chemoradiation: Implications for the Concept of Sphincter-Preserving Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Yi-Jen Chen

    2014-01-01

    Full Text Available Background. We evaluated the anatomic location of the external anal sphincter (EAS to pelvic bony landmarks related to 3-dimensional conformal radiotherapy (3DRT and studied the dosimetric coverage of the EAS in patients undergoing neoadjuvant chemoradiation for rectal cancer. Methods. Sixty-four consecutive rectal cancer patients treated with neoadjuvant chemoradiation were included. All patients were treated in a prone position on a bellyboard by 3DRT. The inferior border of the RT fields was at least 3–5 cm inferior to the gross tumorous volume (GTV or at the inferior border of the obturator foramen (IBOF, whichever was more inferior. The EAS was contoured and dose distributions were determined using dose-volume histograms. Results. In 53 out of 64 cases (82.8%, the EAS was completely inferior to the IBOF. In the remaining 11 cases, the EAS was either overlapping the IBOF (10 cases; 15.6% or completely superior to the IBOF (1 case; 1.7%. The average mean dose delivered to the EAS was 2795 cGy. Lower mean doses were delivered to the EAS when the center of the EAS was located more distant from the GTV. Conclusions. Meticulous planning to define the inferior border of the RT field is recommended to avoid irradiating the EAS.

  9. Recursion Relations for Conformal Blocks

    CERN Document Server

    Penedones, João; Yamazaki, Masahito

    2016-09-12

    In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

  10. Imaging of conformational changes

    Energy Technology Data Exchange (ETDEWEB)

    Michl, Josef [Univ. of Colorado, Boulder, CO (United States)

    2016-03-13

    Control of intramolecular conformational change in a small number of molecules or even a single one by an application of an outside electric field defined by potentials on nearby metal or dielectric surfaces has potential applications in both 3-D and 2-D nanotechnology. Specifically, the synthesis, characterization, and understanding of designed solids with controlled built-in internal rotational motion of a dipole promises a new class of materials with intrinsic dielectric, ferroelectric, optical and optoelectronic properties not found in nature. Controlled rotational motion is of great interest due to its expected utility in phenomena as diverse as transport, current flow in molecular junctions, diffusion in microfluidic channels, and rotary motion in molecular machines. A direct time-resolved observation of the dynamics of motion on ps or ns time scale in a single molecule would be highly interesting but is also very difficult and has yet to be accomplished. Much can be learned from an easier but still challenging comparison of directly observed initial and final orientational states of a single molecule, which is the basis of this project. The project also impacts the understanding of surface-enhanced Raman spectroscopy (SERS) and single-molecule spectroscopic detection, as well as the synthesis of solid-state materials with tailored properties from designed precursors.

  11. Conformal solids and holography

    Science.gov (United States)

    Esposito, A.; Garcia-Saenz, S.; Nicolis, A.; Penco, R.

    2017-12-01

    We argue that a SO( d) magnetic monopole in an asymptotically AdS space-time is dual to a d-dimensional strongly coupled system in a solid state. In light of this, it would be remiss of us not to dub such a field configuration solidon. In the presence of mixed boundary conditions, a solidon spontaneously breaks translations (among many other symmetries) and gives rise to Goldstone excitations on the boundary — the phonons of the solid. We derive the quadratic action for the boundary phonons in the probe limit and show that, when the mixed boundary conditions preserve conformal symmetry, the longitudinal and transverse sound speeds are related to each other as expected from effective field theory arguments. We then include backreaction and calculate the free energy of the solidon for a particular choice of mixed boundary conditions, corresponding to a relevant multi-trace deformation of the boundary theory. We find such free energy to be lower than that of thermal AdS. This suggests that our solidon undergoes a solid-to-liquid first order phase transition by melting into a Schwarzschild-AdS black hole as the temperature is raised.

  12. Locally conformal symplectic manifolds

    Directory of Open Access Journals (Sweden)

    Izu Vaisman

    1985-01-01

    Full Text Available A locally conformal symplectic (l. c. s. manifold is a pair (M2n,Ω where M2n(n>1 is a connected differentiable manifold, and Ω a nondegenerate 2-form on M such that M=⋃αUα (Uα- open subsets. Ω/Uα=eσαΩα, σα:Uα→ℝ, dΩα=0. Equivalently, dΩ=ω∧Ω for some closed 1-form ω. L. c. s. manifolds can be seen as generalized phase spaces of Hamiltonian dynamical systems since the form of the Hamilton equations is, in fact, preserved by homothetic canonical transformations. The paper discusses first Hamiltonian vector fields, and infinitesimal automorphisms (i. a. on l. c. s. manifolds. If (M,Ω has an i. a. X such that ω(X≠0, we say that M is of the first kind and Ω assumes the particular form Ω=dθ−ω∧θ. Such an M is a 2-contact manifold with the structure forms (ω,θ, and it has a vertical 2-dimensional foliation V. If V is regular, we can give a fibration theorem which shows that M is a T2-principal bundle over a symplectic manifold. Particularly, V is regular for some homogeneous l. c. s, manifolds, and this leads to a general construction of compact homogeneous l. c. s, manifolds. Various related geometric results, including reductivity theorems for Lie algebras of i. a. are also given. Most of the proofs are adaptations of corresponding proofs in symplectic and contact geometry. The paper ends with an Appendix which states an analogous fibration theorem in Riemannian geometry.

  13. Tomographic patient registration and conformal avoidance tomotherapy

    Science.gov (United States)

    Aldridge, Jennifer Stacy

    Development of tomotherapy has led to the emergence of several processes, providing the basis for many unique investigative opportunities. These processes include setup verification, tomographic verification, megavoltage dose reconstruction, and conformal avoidance tomotherapy. Setup verification and conformal avoidance tomotherapy, in particular, are two closely intertwined matters. In order to avoid critical structures located within or adjacent to indistinct tumor regions, accurate patient positioning from fraction to fraction must be ensured. With tomographic patient registration, a higher level of assurance is offered than with traditional positioning methods. Translational and rotational offsets are calculated directly from projection data using cross- correlation or fast Fourier transforms. Experiments assessing the algorithm's ability to calculate individual offsets were conducted using the University of Wisconsin's Tomotherapy Benchtop. These experiments indicate statistical errors within +/-1 mm for offsets up to approximately 20 mm, with maximum offset errors of about +/-2 mm for displacements up to 35 mm. The angular offset component is within +/-2°. To evaluate the registration process as a whole, experimental results from a few multi-parameter examples are also analyzed. With the development of tomographic patient registration in projection space, efforts to promote further sparing of critical structures are justified. Conformal avoidance tomotherapy has as its objective to treat an indistinct tumor region while conformally avoiding any normal critical structures in that region. To demonstrate the advantages of conformal avoidance tomotherapy, conventional and tomotherapy treatments are contrasted for both nasopharyngeal and breast carcinoma cases. For initial research efforts, computed tomography data sets of a human male and female were obtained via the ``Visible Human Project''. Since these data sets are on the order of hundreds of megabytes, both

  14. Logarithmic conformal field theory

    Science.gov (United States)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  15. Some Progress in Conformal Geometry

    Directory of Open Access Journals (Sweden)

    Sun-Yung A. Chang

    2007-12-01

    Full Text Available This is a survey paper of our current research on the theory of partial differential equations in conformal geometry. Our intention is to describe some of our current works in a rather brief and expository fashion. We are not giving a comprehensive survey on the subject and references cited here are not intended to be complete. We introduce a bubble tree structure to study the degeneration of a class of Yamabe metrics on Bach flat manifolds satisfying some global conformal bounds on compact manifolds of dimension 4. As applications, we establish a gap theorem, a finiteness theorem for diffeomorphism type for this class, and diameter bound of the $sigma_2$-metrics in a class of conformal 4-manifolds. For conformally compact Einstein metrics we introduce an eigenfunction compactification. As a consequence we obtain some topological constraints in terms of renormalized volumes.

  16. Steady states in conformal theories

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    A novel conjecture regarding the steady state behavior of conformal field theories placed between two heat baths will be presented. Some verification of the conjecture will be provided in the context of fluid dynamics and holography.

  17. Conformity Adequacy Review: Region 5

    Science.gov (United States)

    Resources are for air quality and transportation government and community leaders. Information on the conformity SIP adequacy/inadequacy of state implementation plans (SIPs) in EPA Region 5 (IL, IN, MI, OH, WI) is provided here.

  18. Quality of life study in prostate cancer patients treated with three-dimensional conformal radiation therapy: comparing late bowel and bladder quality of life symptoms to that of the normal population.

    Science.gov (United States)

    Hanlon, A L; Watkins Bruner, D; Peter, R; Hanks, G E

    2001-01-01

    The goals of this study were twofold. First, differences were quantified for symptoms that impact bowel and bladder quality of life (QOL) in prostate cancer patients treated with three-dimensional conformal radiotherapy (3DCRT) alone to the prostate vs. whole pelvis with prostate boost. Second, bowel and bladder QOL measures for these patients were compared to those of the normal population of men with a similar age distribution. Two health status surveys evaluating bowel and bladder functioning, along with the AUA Symptom Problem Index and the BPH Impact Index, were mailed to 195 prostate cancer patients treated with 3DCRT between 12/92 and 11/95 at Fox Chase Cancer Center by a single clinician (GH). No patient received hormonal management as part of his treatment. Ninety-five patients had pretreatment PSA levels or =10 ng/ml, T2B/T3 tumors, Gleason scores 7-10, or perineural invasion. These patients were treated to the whole pelvis followed by a boost to the prostate and are referred to as Group II. Frequencies were tabulated, and differences in percentages for the two groups were evaluated using the two-tailed Fisher's Exact Test. Overall percentages were compared to those for equivalent measures reported by Litwin (1999) based on a normal population of men with a mean age of 73 years (range 47-86). Comparisons to the normal population were also evaluated using two-tailed Fisher's Exact p values. The mailing yielded a high response rate of 71% (n = 139, 66 in Group I and 73 in Group II). The mean age was 67 (range 49-82), and the median ICRU dose levels for Groups I and II were 73 and 76 Gy, respectively. Responses relating to bladder symptoms were similar for Groups I and II, except for the degree of bother associated with trouble in urination over the last month. Percentages for no bother at all were 66% and 56% for Groups I and II, respectively. Observed differences in bowel functioning related to rectal urgency over the past year (22% vs. 40% for Groups I

  19. Falsification of Mannheim's conformal gravity

    CERN Document Server

    Yoon, Youngsub

    2013-01-01

    We show that Mannheim's conformal gravity, whose potential has a term proportional to $1/r$ and another term proportional to $r$, doesn't reduce to Newtonian gravity at short distances. Therefore, despite the claim that it successfully explains galaxy rotation curves, it seems falsified by numerous Cavendish-type experiments performed at laboratories on Earth whose work haven't found any deviations from Newton's theory. Moreover, when Mannheim used his potential to fit the galaxy rotation curve, he used the Newtonian formula to calculate the effects of the term proportional to $1/r$, not the conformal gravity one. So, he lacked consistency. After all, he would not have been able to use the conformal gravity one either since it deviates so much from the Newtonian one, which the conformal gravity one should reduce to. We also give a couple of other similar reasons why Mannheim's conformal gravity is wrong. For example, the gravitational potential of conformal gravity doesn't reduce to the Newtonian one even in ...

  20. Dual integrated overprinting hypo fractionation (2xSIB) for glioblastoma multiform; Hipofraccionamiento de doble sobreimpresion integrada (2xSIB) para el flioblastoma multiforme

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Miranda, S.; Munoz Carmona, D. M.

    2011-07-01

    Glioblastoma multiform e is characterized by being of a proliferative cell type and radiobiological behavior corresponding to an alpha / beta low. This tells us that we will have more success if we deal with fractions of higher doses than the standard treatment, and that shortening the total time is essential to reduce the effects of proliferation.

  1. CONFORMANCE IMPROVEMENT USING GELS

    Energy Technology Data Exchange (ETDEWEB)

    Randall S. Seright

    2003-09-01

    This report describes work performed during the second year of the project, ''Conformance Improvement Using Gels.'' The project has two objectives. The first objective is to identify gel compositions and conditions that substantially reduce flow through fractures that allow direct channeling between wells, while leaving secondary fractures open so that high fluid injection and production rates can be maintained. The second objective is to optimize treatments in fractured production wells, where the gel must reduce permeability to water much more than that to oil. Pore-level images from X-ray computed microtomography were re-examined for Berea sandstone and porous polyethylene. This analysis suggests that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than a gel-ripping mechanism. This finding helps to explain why aqueous gels can reduce permeability to water more than to oil. We analyzed a Cr(III)-acetate-HPAM gel treatment in a production well in the Arbuckle formation. The availability of accurate pressure data before, during, and after the treatment was critical for the analysis. After the gel treatment, water productivity was fairly constant at about 20% of the pre-treatment value. However, oil productivity was stimulated by a factor of 18 immediately after the treatment. During the six months after the treatment, oil productivity gradually decreased to approach the pre-treatment value. To explain this behavior, we proposed that the fracture area open to oil flow was increased substantially by the gel treatment, followed by a gradual closing of the fractures during subsequent production. For a conventional Cr(III)-acetate-HPAM gel, the delay between gelant preparation and injection into a fracture impacts the placement, leakoff, and permeability reduction behavior. Formulations placed as partially formed gels showed relatively low pressure gradients during placement, and yet substantially reduced the

  2. CONFORMANCE IMPROVEMENT USING GELS

    Energy Technology Data Exchange (ETDEWEB)

    Randall S. Seright

    2004-09-30

    This report describes work performed during the third and final year of the project, ''Conformance Improvement Using Gels.'' Corefloods revealed throughput dependencies of permeability reduction by polymers and gels that were much more prolonged during oil flow than water flow. This behavior was explained using simple mobility ratio arguments. A model was developed that quantitatively fits the results and predicts ''clean up'' times for oil productivity when production wells are returned to service after application of a polymer or gel treatment. X-ray computed microtomography studies of gels in strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene suggested that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than gel-ripping or gel-displacement mechanisms. In contrast, analysis of data from the University of Kansas suggests that the gel-ripping or displacement mechanisms are more important in more permeable, strongly water-wet sandpacks. These findings help to explain why aqueous gels can reduce permeability to water more than to oil under different conditions. Since cement is the most commonly used material for water shutoff, we considered when gels are preferred over cements. Our analysis and experimental results indicated that cement cannot be expected to completely fill (top to bottom) a vertical fracture of any width, except near the wellbore. For vertical fractures with apertures less than 4 mm, the cement slurry will simply not penetrate very far into the fracture. For vertical fractures with apertures greater than 4 mm, the slurry may penetrate a substantial distance into the bottom part of the fracture. However, except near the wellbore, the upper part of the fracture will remain open due to gravity segregation. We compared various approaches to plugging fractures using gels, including (1) varying polymer content, (2) varying placement (extrusion) rate

  3. To conform or not to conform: spontaneous conformity diminishes the sensitivity to monetary outcomes.

    Science.gov (United States)

    Yu, Rongjun; Sun, Sai

    2013-01-01

    When people have different opinions in a group, they often adjust their own attitudes and behaviors to match the group opinion, known as social conformity. The affiliation account of normative conformity states that people conform to norms in order to 'fit in', whereas the accuracy account of informative conformity posits that the motive to learn from others produces herding. Here, we test another possibility that following the crowd reduces the experienced negative emotion when the group decision turns out to be a bad one. Using event related potential (ERP) combined with a novel group gambling task, we found that participants were more likely to choose the option that was predominately chosen by other players in previous trials, although there was little explicit normative pressure at the decision stage and group choices were not informative. When individuals' choices were different from others, the feedback related negativity (FRN), an ERP component sensitive to losses and errors, was enhanced, suggesting that being independent is aversive. At the outcome stage, the losses minus wins FRN effect was significantly reduced following conformity choices than following independent choices. Analyses of the P300 revealed similar patterns both in the response and outcome period. Our study suggests that social conformity serves as an emotional buffer that protects individuals from experiencing strong negative emotion when the outcomes are bad.

  4. To conform or not to conform: spontaneous conformity diminishes the sensitivity to monetary outcomes.

    Directory of Open Access Journals (Sweden)

    Rongjun Yu

    Full Text Available When people have different opinions in a group, they often adjust their own attitudes and behaviors to match the group opinion, known as social conformity. The affiliation account of normative conformity states that people conform to norms in order to 'fit in', whereas the accuracy account of informative conformity posits that the motive to learn from others produces herding. Here, we test another possibility that following the crowd reduces the experienced negative emotion when the group decision turns out to be a bad one. Using event related potential (ERP combined with a novel group gambling task, we found that participants were more likely to choose the option that was predominately chosen by other players in previous trials, although there was little explicit normative pressure at the decision stage and group choices were not informative. When individuals' choices were different from others, the feedback related negativity (FRN, an ERP component sensitive to losses and errors, was enhanced, suggesting that being independent is aversive. At the outcome stage, the losses minus wins FRN effect was significantly reduced following conformity choices than following independent choices. Analyses of the P300 revealed similar patterns both in the response and outcome period. Our study suggests that social conformity serves as an emotional buffer that protects individuals from experiencing strong negative emotion when the outcomes are bad.

  5. Conformal Window and Correlation Functions in Lattice Conformal QCD

    CERN Document Server

    Iwasaki, Y

    2012-01-01

    We discuss various aspects of Conformal Field Theories on the Lattice. We investigate the SU(3) gauge theory with Nf fermions in the fundamental representation. First we make a brief review of our previous works on the phase structure of lattice gauge theories in terms of the gauge coupling constant and the quark mass. We thereby clarify the reason why we conjecture that the conformal window is 7 = 1 exhibit the characteristics of the conformal function with IR cutoff, an exponential damping with power correction. Investigating our numerical data by a new method, the "micro-analysis" of propagators, we observe that our data are consistent with the picture that the Nf=7 case and the Nf=2 at T ~ 2Tc case are close to the meson unparticle model. On the other hand, the Nf=16 case and the Nf=2 at T= 10^2 ~10^5 Tc cases are close to the fermion unparticle model.

  6. 40 CFR 93.154 - Conformity analysis.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Conformity analysis. 93.154 Section 93...) DETERMINING CONFORMITY OF FEDERAL ACTIONS TO STATE OR FEDERAL IMPLEMENTATION PLANS Determining Conformity of General Federal Actions to State or Federal Implementation Plans § 93.154 Conformity analysis. Any Federal...

  7. CED: a conformational epitope database

    Directory of Open Access Journals (Sweden)

    Huang Jian

    2006-04-01

    Full Text Available Abstract Background Antigen epitopes provide valuable information useful for disease prevention, diagnosis, and treatment. Recently, more and more databases focusing on different types of epitopes have become available. Conformational epitopes are an important form of epitope formed by residues that are sequentially discontinuous but close together in three-dimensional space. These epitopes have implicit structural information, making them attractive for both theoretical and applied biomedical research. However, most existing databases focus on linear rather than conformational epitopes. Description We describe CED, a special database of well defined conformational epitopes. CED provides a collection of conformational epitopes and related information including the residue make up and location of the epitope, the immunological property of the epitope, the source antigen and corresponding antibody of the epitope. All entries in this database are manually curated from articles published in peer review journals. The database can be browsed or searched through a user-friendly web interface. Most epitopes in CED can also be viewed interactively in the context of their 3D structures. In addition, the entries are also hyperlinked to various databases such as Swiss-Prot, PDB, KEGG and PubMed, providing wide background information. Conclusion A conformational epitope database called CED has been developed as an information resource for investigators involved in both theoretical and applied immunology research. It complements other existing specialised epitope databases. The database is freely available at http://web.kuicr.kyoto-u.ac.jp/~ced

  8. Conformal geometry and quasiregular mappings

    CERN Document Server

    Vuorinen, Matti

    1988-01-01

    This book is an introduction to the theory of spatial quasiregular mappings intended for the uninitiated reader. At the same time the book also addresses specialists in classical analysis and, in particular, geometric function theory. The text leads the reader to the frontier of current research and covers some most recent developments in the subject, previously scatterd through the literature. A major role in this monograph is played by certain conformal invariants which are solutions of extremal problems related to extremal lengths of curve families. These invariants are then applied to prove sharp distortion theorems for quasiregular mappings. One of these extremal problems of conformal geometry generalizes a classical two-dimensional problem of O. Teichmüller. The novel feature of the exposition is the way in which conformal invariants are applied and the sharp results obtained should be of considerable interest even in the two-dimensional particular case. This book combines the features of a textbook an...

  9. Logarithmic exotic conformal Galilean algebras

    Energy Technology Data Exchange (ETDEWEB)

    Henkel, Malte, E-mail: Malte.henkel@univ-lorraine.fr [Groupe de Physique Statistique, Institut Jean Lamour (CNRS UMR 7198), Université de Lorraine Nancy, B.P. 70239, F-54506 Vandoeuvre-lès-Nancy Cedex (France); Hosseiny, Ali, E-mail: al_hosseiny@sbu.ac.ir [Department of Physics, Shahid Beheshti University, G.C. Evin, Tehran 19839 (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Rouhani, Shahin, E-mail: rouhani@ipm.ir [Department of Physics, Sharif University of Technology, P.O. Box 11165-9161, Tehran (Iran, Islamic Republic of); School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2014-02-15

    Logarithmic representations of the conformal Galilean algebra (CGA) and the Exotic Conformal Galilean algebra (ECGA) are constructed. This can be achieved by non-decomposable representations of the scaling dimensions or the rapidity indices, specific to conformal Galilean algebras. Logarithmic representations of the non-exotic CGA lead to the expected constraints on scaling dimensions and rapidities and also on the logarithmic contributions in the co-variant two-point functions. On the other hand, the ECGA admits several distinct situations which are distinguished by different sets of constraints and distinct scaling forms of the two-point functions. Two distinct realisations for the spatial rotations are identified as well. This is the first concrete example of a reducible, but non-decomposable representation, without logarithmic terms. Such cases had been anticipated before.

  10. Social influence: compliance and conformity.

    Science.gov (United States)

    Cialdini, Robert B; Goldstein, Noah J

    2004-01-01

    This review covers recent developments in the social influence literature, focusing primarily on compliance and conformity research published between 1997 and 2002. The principles and processes underlying a target's susceptibility to outside influences are considered in light of three goals fundamental to rewarding human functioning. Specifically, targets are motivated to form accurate perceptions of reality and react accordingly, to develop and preserve meaningful social relationships, and to maintain a favorable self-concept. Consistent with the current movement in compliance and conformity research, this review emphasizes the ways in which these goals interact with external forces to engender social influence processes that are subtle, indirect, and outside of awareness.

  11. Epigenetic dominance of prion conformers.

    Directory of Open Access Journals (Sweden)

    Eri Saijo

    2013-10-01

    Full Text Available Although they share certain biological properties with nucleic acid based infectious agents, prions, the causative agents of invariably fatal, transmissible neurodegenerative disorders such as bovine spongiform encephalopathy, sheep scrapie, and human Creutzfeldt Jakob disease, propagate by conformational templating of host encoded proteins. Once thought to be unique to these diseases, this mechanism is now recognized as a ubiquitous means of information transfer in biological systems, including other protein misfolding disorders such as those causing Alzheimer's and Parkinson's diseases. To address the poorly understood mechanism by which host prion protein (PrP primary structures interact with distinct prion conformations to influence pathogenesis, we produced transgenic (Tg mice expressing different sheep scrapie susceptibility alleles, varying only at a single amino acid at PrP residue 136. Tg mice expressing ovine PrP with alanine (A at (OvPrP-A136 infected with SSBP/1 scrapie prions propagated a relatively stable (S prion conformation, which accumulated as punctate aggregates in the brain, and produced prolonged incubation times. In contrast, Tg mice expressing OvPrP with valine (V at 136 (OvPrP-V136 infected with the same prions developed disease rapidly, and the converted prion was comprised of an unstable (U, diffusely distributed conformer. Infected Tg mice co-expressing both alleles manifested properties consistent with the U conformer, suggesting a dominant effect resulting from exclusive conversion of OvPrP-V136 but not OvPrP-A136. Surprisingly, however, studies with monoclonal antibody (mAb PRC5, which discriminates OvPrP-A136 from OvPrP-V136, revealed substantial conversion of OvPrP-A136. Moreover, the resulting OvPrP-A136 prion acquired the characteristics of the U conformer. These results, substantiated by in vitro analyses, indicated that co-expression of OvPrP-V136 altered the conversion potential of OvPrP-A136 from the S to

  12. Youth Conformity Regarding Institutions and Media

    Directory of Open Access Journals (Sweden)

    Nikolay Ivantchev

    2012-10-01

    Full Text Available An experiment on conformity was carried out. The participants were 95 youths. The scale “Conformity – Autonomy” from I. Karagiozov’s questionnaire for locus of control (1998 was also used. The results indicated the prevalence of youth conformity regarding institutions and media. The different types of conformity were related to each other. The subjects’ gender and the experimentators’ gender mediated the connections between the both types of conformity. The female youths conformed more with institutions than the male youths, but there were not any significant gender differences in their conform behavior regarding media (magazines. More male youths conformed for the magazines when the experimentator was a woman. More female youths conformed for the magazines when the experimentator was a man.

  13. Defects in conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Billò, Marco [Dipartimento di Fisica, Università di Torino, and Istituto Nazionale di Fisica Nucleare - sezione di Torino,Via P. Giuria 1 I-10125 Torino (Italy); Gonçalves, Vasco [Centro de Física do Porto,Departamento de Física e Astronomia Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); ICTP South American Institute for Fundamental Research Instituto de Física Teórica,UNESP - University Estadual Paulista,Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil); Lauria, Edoardo [Institute for Theoretical Physics, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Meineri, Marco [Perimeter Institute for Theoretical Physics,Waterloo, Ontario, N2L 2Y5 (Canada); Scuola Normale Superiore, and Istituto Nazionale di Fisica Nucleare - sezione di Pisa,Piazza dei Cavalieri 7 I-56126 Pisa (Italy)

    2016-04-15

    We discuss consequences of the breaking of conformal symmetry by a flat or spherical extended operator. We adapt the embedding formalism to the study of correlation functions of symmetric traceless tensors in the presence of the defect. Two-point functions of a bulk and a defect primary are fixed by conformal invariance up to a set of OPE coefficients, and we identify the allowed tensor structures. A correlator of two bulk primaries depends on two cross-ratios, and we study its conformal block decomposition in the case of external scalars. The Casimir equation in the defect channel reduces to a hypergeometric equation, while the bulk channel blocks are recursively determined in the light-cone limit. In the special case of a defect of codimension two, we map the Casimir equation in the bulk channel to the one of a four-point function without defect. Finally, we analyze the contact terms of the stress-tensor with the extended operator, and we deduce constraints on the CFT data. In two dimensions, we relate the displacement operator, which appears among the contact terms, to the reflection coefficient of a conformal interface, and we find unitarity bounds for the latter.

  14. Conformation analysis of oligomeric flavanoids

    Science.gov (United States)

    Jan P. Steynberg; E. Vincent Brandt; Daneel Ferreira; Carin A. Helfer; Wayne L. Mattice; Dominika Gornik; Richard W. Hemingway

    1995-01-01

    The profisetinidins are the most important polyflavanoids of commerce, making up the major constituents of wattle and quebracho tannins. Within the dimeric profisetinidins, substantial complexity exists because of stereo-, regio, rotational and conformational isomers. Definition of the stereochemistry of the upper and lower flavan units, the location of the...

  15. Conformal symmetry and holographic cosmology

    NARCIS (Netherlands)

    Bzowski, A.W.

    2013-01-01

    This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of

  16. Free fructose is conformationally locked.

    Science.gov (United States)

    Cocinero, Emilio J; Lesarri, Alberto; Écija, Patricia; Cimas, Álvaro; Davis, Benjamin G; Basterretxea, Francisco J; Fernández, José A; Castaño, Fernando

    2013-02-20

    Fructose has been examined under isolation conditions using a combination of UV ultrafast laser vaporization and Fourier-transform microwave (FT-MW) spectroscopy. The rotational spectra for the parent, all (six) monosubstituted (13)C species, and two single D species reveal unambiguously that the free hexoketose is conformationally locked in a single dominant β-pyranose structure. This six-membered-chair skeleton adopts a (2)C(5) configuration (equivalent to (1)C(4) in aldoses). The free-molecule structure sharply contrasts with the furanose form observed in biochemically relevant polysaccharides, like sucrose. The structure of free fructose has been determined experimentally using substitution and effective structures. The enhanced stability of the observed conformation is primarily attributed to a cooperative network of five intramolecular O-H···O hydrogen bonds and stabilization of both endo and exo anomeric effects. Breaking a single intramolecular hydrogen bond destabilizes the free molecule by more than 10 kJ mol(-1). The structural results are compared to ribose, recently examined with rotational resolution, where six different conformations coexist with similar conformational energies. In addition, several DFT and ab initio methods and basis sets are benchmarked with the experimental data.

  17. Exceptional and Spinorial Conformal Windows

    DEFF Research Database (Denmark)

    Mojaza, Matin; Pica, Claudio; Ryttov, Thomas

    2012-01-01

    We study the conformal window of gauge theories containing fermionic matter fields, where the gauge group is any of the exceptional groups with the fermions transforming according to the fundamental and adjoint representations and the orthogonal groups where the fermions transform according...

  18. Anomalous Dimensions of Conformal Baryons

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2016-01-01

    We determine the anomalous dimensions of baryon operators for the three color theory as function of the number of massless flavours within the conformal window to the maximum known order in perturbation theory. We show that the anomalous dimension of the baryon is controllably small, within...

  19. Solution conformation of the response regulator proteins from Deinococcus radiodurans studied by SAXS

    Science.gov (United States)

    Li, Li-Qin; Liu, Ying; Liu, Peng; Dong, Yu-Hui

    2011-10-01

    In this paper the solution conformation of the response regulator proteins from Deinococcus radiodurans was studied by small-angle X-ray scattering (SAXS). The SAXS curves of Dr-rrA in solutions were obtained at Beamline 1W2A of Beijing Synchrotron Radiation Facility (BSRF). Two possible conformations of the response regulator proteins, compact and incompact conformations, have been represented by the known crystallographic structures. And theoretical solution scattering curves of the two possible conformations were calculated and fitted to the experimental scattering curve of Dr-rrA, respectively. The result indicates that the solution conformation of the response regulator proteins is inclined to the compact one, which is in agreement with the result of biochemical experiments.

  20. Effect of intra-fraction motion on the accumulated dose for free-breathing MR-guided stereotactic body radiation therapy of renal-cell carcinoma

    Science.gov (United States)

    Stemkens, Bjorn; Glitzner, Markus; Kontaxis, Charis; de Senneville, Baudouin Denis; Prins, Fieke M.; Crijns, Sjoerd P. M.; Kerkmeijer, Linda G. W.; Lagendijk, Jan J. W.; van den Berg, Cornelis A. T.; Tijssen, Rob H. N.

    2017-09-01

    Stereotactic body radiation therapy (SBRT) has shown great promise in increasing local control rates for renal-cell carcinoma (RCC). Characterized by steep dose gradients and high fraction doses, these hypo-fractionated treatments are, however, prone to dosimetric errors as a result of variations in intra-fraction respiratory-induced motion, such as drifts and amplitude alterations. This may lead to significant variations in the deposited dose. This study aims to develop a method for calculating the accumulated dose for MRI-guided SBRT of RCC in the presence of intra-fraction respiratory variations and determine the effect of such variations on the deposited dose. For this, RCC SBRT treatments were simulated while the underlying anatomy was moving, based on motion information from three motion models with increasing complexity: (1) STATIC, in which static anatomy was assumed, (2) AVG-RESP, in which 4D-MRI phase-volumes were time-weighted, and (3) PCA, a method that generates 3D volumes with sufficient spatio-temporal resolution to capture respiration and intra-fraction variations. Five RCC patients and two volunteers were included and treatments delivery was simulated, using motion derived from subject-specific MR imaging. Motion was most accurately estimated using the PCA method with root-mean-squared errors of 2.7, 2.4, 1.0 mm for STATIC, AVG-RESP and PCA, respectively. The heterogeneous patient group demonstrated relatively large dosimetric differences between the STATIC and AVG-RESP, and the PCA reconstructed dose maps, with hotspots up to 40% of the D99 and an underdosed GTV in three out of the five patients. This shows the potential importance of including intra-fraction motion variations in dose calculations.

  1. Experimental demonstration of conformal phased array antenna via transformation optics.

    Science.gov (United States)

    Lei, Juan; Yang, Juxing; Chen, Xi; Zhang, Zhiya; Fu, Guang; Hao, Yang

    2018-02-28

    Transformation Optics has been proven a versatile technique for designing novel electromagnetic devices and it has much wider applicability in many subject areas related to general wave equations. Among them, quasi-conformal transformation optics (QCTO) can be applied to minimize anisotropy of transformed media and has opened up the possibility to the design of broadband antennas with arbitrary geometries. In this work, a wide-angle scanning conformal phased array based on all-dielectric QCTO lens is designed and experimentally demonstrated. Excited by the same current distribution as such in a conventional planar array, the conformal system in presence of QCTO lens can preserve the same radiation characteristics of a planar array with wide-angle beam-scanning and low side lobe level (SLL). Laplace's equation subject to Dirichlet-Neumann boundary conditions is adopted to construct the mapping between the virtual and physical spaces. The isotropic lens with graded refractive index is realized by all-dielectric holey structure after an effective parameter approximation. The measurements of the fabricated system agree well with the simulated results, which demonstrate its excellent wide-angle beam scanning performance. Such demonstration paves the way to a robust but efficient array synthesis, as well as multi-beam and beam forming realization of conformal arrays via transformation optics.

  2. Conformal Bootstrap in Mellin Space

    Science.gov (United States)

    Gopakumar, Rajesh; Kaviraj, Apratim; Sen, Kallol; Sinha, Aninda

    2017-02-01

    We propose a new approach towards analytically solving for the dynamical content of conformal field theories (CFTs) using the bootstrap philosophy. This combines the original bootstrap idea of Polyakov with the modern technology of the Mellin representation of CFT amplitudes. We employ exchange Witten diagrams with built-in crossing symmetry as our basic building blocks rather than the conventional conformal blocks in a particular channel. Demanding consistency with the operator product expansion (OPE) implies an infinite set of constraints on operator dimensions and OPE coefficients. We illustrate the power of this method in the ɛ expansion of the Wilson-Fisher fixed point by reproducing anomalous dimensions and, strikingly, obtaining OPE coefficients to higher orders in ɛ than currently available using other analytic techniques (including Feynman diagram calculations). Our results enable us to get a somewhat better agreement between certain observables in the 3D Ising model and the precise numerical values that have been recently obtained.

  3. Conformal FDTD modeling wake fields

    Energy Technology Data Exchange (ETDEWEB)

    Jurgens, T.; Harfoush, F.

    1991-05-01

    Many computer codes have been written to model wake fields. Here we describe the use of the Conformal Finite Difference Time Domain (CFDTD) method to model the wake fields generated by a rigid beam traveling through various accelerating structures. The non- cylindrical symmetry of some of the problems considered here requires the use of a three dimensional code. In traditional FDTD codes, curved surfaces are approximated by rectangular steps. The errors introduced in wake field calculations by such an approximation can be reduced by increasing the mesh size, therefore increasing the cost of computing. Another approach, validated here, deforms Ampere and Faraday contours near a media interface so as to conform to the interface. These improvements of the FDTD method result in better accuracy of the fields at asymptotically no computational cost. This method is also capable of modeling thin wires as found in beam profile monitors, and slots and cracks as found in resistive wall motions. 4 refs., 5 figs.

  4. Conformal gravity and "gravitational bubbles"

    CERN Document Server

    Berezin, V A; Eroshenko, Yu N

    2015-01-01

    We describe the general structure of the spherically symmetric solutions in the Weyl conformal gravity. The corresponding Bach equations are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions, consisting of two classes, is found. The first one contains the solutions with constant two-dimensional curvature scalar, and the representatives are the famous Robertson--Walker metrics. We called one of them the "gravitational bubbles", which is compact and with zero Weyl tensor. These "gravitational bubbles" are the pure vacuum curved space-times (without any material sources, including the cosmological constant), which are absolutely impossible in General Relativity. This phenomenon makes it easier to create the universe from "nothing". The second class consists of the solutions with varying curvature scalar. We found its representative as the one-parameter family, which can be conformally covered by the thee-para...

  5. Gel dosimetry for conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G. [Department of Physics of the University and INFN, Milan (Italy)]. e-mail: grazia.gambarini@mi.infn.it

    2005-07-01

    With the continuum development of conformal radio therapies, aimed at delivering high dose to tumor tissue and low dose to the healthy tissue around, the necessities has appeared of suitable improvement of dosimetry techniques giving the possibility of obtaining dose images to be compared with diagnostic images. Also if wide software has been developed for calculating dose distributions in the fields of various radiotherapy units, experimental verifications are necessary, in particular in the case of complex geometries in conformal radiotherapy. Gel dosimetry is a promising method for imaging the absorbed dose in tissue-equivalent phantoms, with the possibility of 3D reconstruction of the spatial dose distribution, with milli metric resolution. Optical imaging of gel dosimeters, based on visible light absorbance analysis, has shown to be a reliable technique for achieving dose distributions. (Author)

  6. Conformal methods in general relativity

    CERN Document Server

    Valiente Kroon, Juan A

    2016-01-01

    This book offers a systematic exposition of conformal methods and how they can be used to study the global properties of solutions to the equations of Einstein's theory of gravity. It shows that combining these ideas with differential geometry can elucidate the existence and stability of the basic solutions of the theory. Introducing the differential geometric, spinorial and PDE background required to gain a deep understanding of conformal methods, this text provides an accessible account of key results in mathematical relativity over the last thirty years, including the stability of de Sitter and Minkowski spacetimes. For graduate students and researchers, this self-contained account includes useful visual models to help the reader grasp abstract concepts and a list of further reading, making this the perfect reference companion on the topic.

  7. Gluon Amplitudes as 2d Conformal Correlators

    OpenAIRE

    Pasterski, Sabrina; Shao, Shu-Heng; Strominger, Andrew

    2017-01-01

    Recently, spin-one wavefunctions in four dimensions that are conformal primaries of the Lorentz group SL(2,C) were constructed. We compute low-point, tree-level gluon scattering amplitudes in the space of these conformal primary wavefunctions. The answers have the same conformal covariance as correlators of spin-one primaries in a 2d CFT. The BCFW recursion relation between three- and four-point gluon amplitudes is recast into this conformal basis.

  8. Integrability of conformal fishnet theory

    Science.gov (United States)

    Gromov, Nikolay; Kazakov, Vladimir; Korchemsky, Gregory; Negro, Stefano; Sizov, Grigory

    2018-01-01

    We study integrability of fishnet-type Feynman graphs arising in planar four-dimensional bi-scalar chiral theory recently proposed in arXiv:1512.06704 as a special double scaling limit of gamma-deformed N = 4 SYM theory. We show that the transfer matrix "building" the fishnet graphs emerges from the R-matrix of non-compact conformal SU(2 , 2) Heisenberg spin chain with spins belonging to principal series representations of the four-dimensional conformal group. We demonstrate explicitly a relationship between this integrable spin chain and the Quantum Spectral Curve (QSC) of N = 4 SYM. Using QSC and spin chain methods, we construct Baxter equation for Q-functions of the conformal spin chain needed for computation of the anomalous dimensions of operators of the type tr( ϕ 1 J ) where ϕ 1 is one of the two scalars of the theory. For J = 3 we derive from QSC a quantization condition that fixes the relevant solution of Baxter equation. The scaling dimensions of the operators only receive contributions from wheel-like graphs. We develop integrability techniques to compute the divergent part of these graphs and use it to present the weak coupling expansion of dimensions to very high orders. Then we apply our exact equations to calculate the anomalous dimensions with J = 3 to practically unlimited precision at any coupling. These equations also describe an infinite tower of local conformal operators all carrying the same charge J = 3. The method should be applicable for any J and, in principle, to any local operators of bi-scalar theory. We show that at strong coupling the scaling dimensions can be derived from semiclassical quantization of finite gap solutions describing an integrable system of noncompact SU(2 , 2) spins. This bears similarities with the classical strings arising in the strongly coupled limit of N = 4 SYM.

  9. Objective interpretation as conforming interpretation

    Directory of Open Access Journals (Sweden)

    Lidka Rodak

    2011-12-01

    Full Text Available The practical discourse willingly uses the formula of “objective interpretation”, with no regards to its controversial nature that has been discussed in literature.The main aim of the article is to investigate what “objective interpretation” could mean and how it could be understood in the practical discourse, focusing on the understanding offered by judicature.The thesis of the article is that objective interpretation, as identified with textualists’ position, is not possible to uphold, and should be rather linked with conforming interpretation. And what this actually implies is that it is not the virtue of certainty and predictability – which are usually associated with objectivity- but coherence that makes the foundation of applicability of objectivity in law.What could be observed from the analyses, is that both the phenomenon of conforming interpretation and objective interpretation play the role of arguments in the interpretive discourse, arguments that provide justification that interpretation is not arbitrary or subjective. With regards to the important part of the ideology of legal application which is the conviction that decisions should be taken on the basis of law in order to exclude arbitrariness, objective interpretation could be read as a question “what kind of authority “supports” certain interpretation”? that is almost never free of judicial creativity and judicial activism.One can say that, objective and conforming interpretation are just another arguments used in legal discourse.

  10. Electrophysiological precursors of social conformity.

    Science.gov (United States)

    Shestakova, Anna; Rieskamp, Jörg; Tugin, Sergey; Ossadtchi, Alexey; Krutitskaya, Janina; Klucharev, Vasily

    2013-10-01

    Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment.

  11. Electrophysiological precursors of social conformity

    Science.gov (United States)

    Rieskamp, Jörg; Tugin, Sergey; Ossadtchi, Alexey; Krutitskaya, Janina; Klucharev, Vasily

    2013-01-01

    Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment. PMID:22683703

  12. Conformational Study of Dibenzyl Ether

    Science.gov (United States)

    Hernandez-Castillo, Alicia O.; Abeysekera, Chamara; Hewett, Daniel M.; Zwier, Timothy S.

    2017-06-01

    Understanding the initial stages of polycyclic aromatic hydrocarbon (PAH) aggregation, the onset of soot formation, is an important goal on the pathway to cleaner combustion processes. PAHs with short alkyl chains, present in fuel-rich combustion environments, can undergo reactions that will chemically link aromatic rings together. One such example of a linked diaryl compound is dibenzyl ether, C_{6}H_{5}-CH_{2}-O-CH_{2}-C_{6}H_{5}. The -CH_{2}-O-CH_{2}- linkage has a length and flexibility well-suited to forming a π-stacked conformation between the two phenyl rings. In this talk, we will explore the single-conformation spectroscopy of dibenzyl ether under jet-cooled conditions in the gas phase. Laser-induced fluorescence, chirped pulse Fourier transform microwave (8-18 GHz region), and single-conformation infrared spectroscopy in the alkyl CH stretch region were all carried out on the molecule, thereby interrogating its full array of electronic, vibrational and rotational degrees of freedom. This work is the first step in a broader study to determine the extent of π-stacking in linked aryl compounds as a function of linkage and PAH size.

  13. Reinforcement learning signal predicts social conformity.

    NARCIS (Netherlands)

    Klucharev, V.; Hytonen, K.A.; Rijpkema, M.J.P.; Smidts, A.; Fernandez, G.S.E.

    2009-01-01

    We often change our decisions and judgments to conform with normative group behavior. However, the neural mechanisms of social conformity remain unclear. Here we show, using functional magnetic resonance imaging, that conformity is based on mechanisms that comply with principles of reinforcement

  14. Herding, Social Preferences and (Non-) Conformity

    OpenAIRE

    Luca Corazzini; Ben Greiner

    2005-01-01

    We study the role of social preferences and conformity in explaining herding behavior in anonymous risky environments. In an experiment similar to information cascade settings, but with no private information, we find no evidence for conformity. On the contrary, we observe a significant amount of non-conforming behavior, which cannot be attributed to errors.

  15. 40 CFR 52.2133 - General conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false General conformity. 52.2133 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) South Carolina § 52.2133 General conformity. The General Conformity regulations adopted into the South Carolina State Implementation Plan which...

  16. Conformity in Christ | Waaijman | Acta Theologica

    African Journals Online (AJOL)

    This essay investigates the notion of conformity in Christ as it is part of a comprehensive, multilayered process of transformation. In the first part it focuses on the process of transformation in creation, re-creation, conformity, love and glory. In the second part it discusses transformation in Christ by looking at conformation and ...

  17. 40 CFR 52.938 - General conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false General conformity. 52.938 Section 52...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.938 General conformity. The General Conformity regulations were submitted on November 10, 1995, and adopted into the Kentucky State...

  18. CONFORMITY IN CHRIST 1. THE TRANSFORMATION PROCESS

    African Journals Online (AJOL)

    This essay investigates the notion of conformity in Christ as it is part of a compre- hensive, multilayered process of transformation. In the first part it focuses on the process of transformation in creation, re-creation, conformity, love and glory. In the second part it discusses transformation in Christ by looking at conformation and ...

  19. 40 CFR 51.854 - Conformity analysis.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Conformity analysis. 51.854 Section 51... FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Determining Conformity of General Federal Actions to State or Federal Implementation Plans § 51.854 Conformity analysis. Link to an...

  20. Mapping the conformational landscape of a dynamic enzyme by multitemperature and XFEL crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Keedy, Daniel A.; Kenner, Lillian R.; Warkentin, Matthew; Woldeyes, Rahel A.; Hopkins, Jesse B.; Thompson, Michael C.; Brewster, Aaron S.; Van Benschoten, Andrew H.; Baxter, Elizabeth L.; Uervirojnangkoorn, Monarin; McPhillips, Scott E.; Song, Jinhu; Alonso-Mori, Roberto; Holton, James M.; Weis, William I.; Brunger, Axel T.; Soltis, S. Michael; Lemke, Henrik; Gonzalez, Ana; Sauter, Nicholas K.; Cohen, Aina E.; van den Bedem, Henry; Thorne, Robert E.; Fraser, James S.

    2015-09-30

    Determining the interconverting conformations of dynamic proteins in atomic detail is a major challenge for structural biology. Conformational heterogeneity in the active site of the dynamic enzyme cyclophilin A (CypA) has been previously linked to its catalytic function, but the extent to which the different conformations of these residues are correlated is unclear. Here we compare the conformational ensembles of CypA by multitemperature synchrotron crystallography and fixed-target X-ray free-electron laser (XFEL) crystallography. The diffraction-before-destruction nature of XFEL experiments provides a radiation-damage-free view of the functionally important alternative conformations of CypA, confirming earlier synchrotron-based results. We monitored the temperature dependences of these alternative conformations with eight synchrotron datasets spanning 100-310 K. Multiconformer models show that many alternative conformations in CypA are populated only at 240 K and above, yet others remain populated or become populated at 180 K and below. These results point to a complex evolution of conformational heterogeneity between 180-–240 K that involves both thermal deactivation and solvent-driven arrest of protein motions in the crystal. The lack of a single shared conformational response to temperature within the dynamic active-site network provides evidence for a conformation shuffling model, in which exchange between rotamer states of a large aromatic ring in the middle of the network shifts the conformational ensemble for the other residues in the network. Together, our multitemperature analyses and XFEL data motivate a new generation of temperature- and time-resolved experiments to structurally characterize the dynamic underpinnings of protein function.

  1. Radiation Therapy

    Science.gov (United States)

    ... Be extra careful not to spend time with children or pregnant women. Internal Radiation Therapy Makes You Give Off Radiation With systemic radiation, your body fluids ( urine , sweat, and saliva ) will give off radiation for a while. With ...

  2. Radiation enteritis

    Science.gov (United States)

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  3. The solutions of time and space conformable fractional heat equations with conformable Fourier transform

    Directory of Open Access Journals (Sweden)

    Çenesiz Yücel

    2015-12-01

    Full Text Available In this paper our aim is to find the solutions of time and space fractional heat differential equations by using new definition of fractional derivative called conformable fractional derivative. Also based on conformable fractional derivative definition conformable Fourier Transform is defined. Fourier sine and Fourier cosine transform definitions are given and space fractional heat equation is solved by conformable Fourier transform.

  4. Different Approaches in Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Rolf-Dieter eKortmann

    2011-12-01

    Full Text Available Radiation therapy is a cornerstone in the therapeutic management of craniopharyngioma. The close proximity to neighbouring eloquent structures pose a particular challenge to radiation therapy. Modern treatment technologies including fractionated 3-d conformal radiotherapy, intensity modulated radiation therapy and recently proton therapy are able to precisely cover the target while preserving surrounding tissue,Tumour controls between 80 and in access of 90 % can be achieved. Alternative treatments consisting of radiosurgery, intracavitary application of isotopes and brachytherapy also offer an acceptable tumour control and might be given in selected cases. More research is needed to establish the role of each treatment modality.

  5. Conformal symmetry inheritance in null fluid spacetimes

    CERN Document Server

    Tupper, B O J; Hall, G S; Coley, Alan A; Carot, J

    2003-01-01

    We define inheriting conformal Killing vectors for null fluid spacetimes and find the maximum dimension of the associated inheriting Lie algebra. We show that for non-conformally flat null fluid spacetimes, the maximum dimension of the inheriting algebra is seven and for conformally flat null fluid spacetimes the maximum dimension is eight. In addition, it is shown that there are two distinct classes of non-conformally flat generalized plane wave spacetimes which possess the maximum dimension, and one class in the conformally flat case.

  6. Hawking radiation of five-dimensional charged black holes with scalar fields

    Directory of Open Access Journals (Sweden)

    Yan-Gang Miao

    2017-09-01

    Full Text Available We investigate the Hawking radiation cascade from the five-dimensional charged black hole with a scalar field coupled to higher-order Euler densities in a conformally invariant manner. We give the semi-analytic calculation of greybody factors for the Hawking radiation. Our analysis shows that the Hawking radiation cascade from this five-dimensional black hole is extremely sparse. The charge enhances the sparsity of the Hawking radiation, while the conformally coupled scalar field reduces this sparsity.

  7. A Cylindrical Wideband Conformal Fractal Antenna for GPS Application

    Directory of Open Access Journals (Sweden)

    R. Sahoo

    2017-10-01

    Full Text Available In this paper, a novel wideband conformal fractal antenna is proposed for GPS application. The concepts of fractal and partial ground are used in conformal antenna design for miniaturization and bandwidth enhancement. It comprises of Minkowski fractal patch on a substrate of Rogers RT/duroid 5880 with permittivity 2.2 and thickness of 0.787mm with microstrip inset feed. The proposed conformal antenna has a patch dimension about 0.39λmm×0.39λmm, and partial ground plane size is 29mm×90mm.The proposed antenna is simulated, fabricated and measured for both planar and conformal geometry, with good agreement between measurements and simulations. The size of the fractal patch is reduced approximately by 32% as compared with conventional patch. It is observed that the conformal antenna exhibits a fractional bandwidth(for the definition of -10dB of 43.72% operating from 1.09 to 1.7GHz, which is useful for L1(1.56-1.58GHz, L2(1.21-1.23GHz, L3(1.37-1.39GHz, L4(1.36-1.38GHz, and L5(1.16-1.18 GHz in GPS and Galileo frequencies: E=1589.742MHz(4MHzbandwidth, E2=1561. 098MHz(4MHzbandwidth, E5a=1176.45MHz(=L5,E5b= 1207.14MHz, and E6=1278.75MHz(40MHz bandwidth. The radiation pattern exhibits an omnidirectional pattern, and gain of proposed antenna is 2.3dBi to 3.5dBi within operating frequency range.

  8. Families and degenerations of conformal field theories

    Energy Technology Data Exchange (ETDEWEB)

    Roggenkamp, D.

    2004-09-01

    In this work, moduli spaces of conformal field theories are investigated. In the first part, moduli spaces corresponding to current-current deformation of conformal field theories are constructed explicitly. For WZW models, they are described in detail, and sigma model realizations of the deformed WZW models are presented. The second part is devoted to the study of boundaries of moduli spaces of conformal field theories. For this purpose a notion of convergence of families of conformal field theories is introduced, which admits certain degenerated conformal field theories to occur as limits. To such a degeneration of conformal field theories, a degeneration of metric spaces together with additional geometric structures can be associated, which give rise to a geometric interpretation. Boundaries of moduli spaces of toroidal conformal field theories, orbifolds thereof and WZW models are analyzed. Furthermore, also the limit of the discrete family of Virasoro minimal models is investigated. (orig.)

  9. The Biological Bases of Conformity

    Science.gov (United States)

    Morgan, T. J. H.; Laland, K. N.

    2012-01-01

    Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favor adaptive learning strategies that facilitate effective copying and decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behavior in non-human animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history, and ontogeny of conformity, and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behavior conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subjects’ behavior is the result of both social and asocial influences, the resultant behavior may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for effective social learning. PMID:22712006

  10. Gauge choice in conformal gravity

    Science.gov (United States)

    Sultana, Joseph; Kazanas, Demosthenes

    2017-04-01

    In a recent paper, K. Horne examined the effect of a conformally coupled scalar field (referred to as Higgs field) on the Mannheim-Kazanas metric gμν, i.e. the static spherically symmetric metric within the context of conformal gravity, and studied its effect on the rotation curves of galaxies. He showed that for a Higgs field of the form S(r) = S0a/(r + a), where a is a radial length-scale, the equivalent Higgs-frame Mannheim-Kazanas metric \\tilde{g}_{μ ν } = Ω ^2 g_{μ ν }, with Ω = S(r)/S0, lacks the linear γr term, which has been employed in the fitting of the galactic rotation curves without the need to invoke dark matter. In this brief note, we point out that the representation of the Mannheim-Kazanas metric in a gauge, where it lacks the linear term, has already been presented by others, including Mannheim and Kazanas themselves, without the need to introduce a conformally coupled Higgs field. Furthermore, Horne argues that the absence of the linear term resolves the issue of light bending in the wrong direction, i.e. away from the gravitating mass, if γr > 0 in the Mannheim-Kazanas metric, a condition necessary to resolve the galactic dynamics in the absence of dark matter. In this case, we also point out that the elimination of the linear term is not even required because the sign of the γr term in the metric can be easily reversed by a simple gauge transformation, and also that the effects of this term are indeed too small to be observed.

  11. The Biological Bases of Conformity

    Directory of Open Access Journals (Sweden)

    Thomas Joshau Henry Morgan

    2012-06-01

    Full Text Available Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favour adaptive learning strategies that facilitate effective use of social information in decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behaviour in nonhuman animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history and ontogeny of conformity and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behaviour conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subject’s behaviour is the result of both social and asocial influences, the resultant behaviour may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for

  12. The biological bases of conformity.

    Science.gov (United States)

    Morgan, T J H; Laland, K N

    2012-01-01

    Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favor adaptive learning strategies that facilitate effective copying and decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behavior in non-human animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history, and ontogeny of conformity, and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behavior conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subjects' behavior is the result of both social and asocial influences, the resultant behavior may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for effective social learning.

  13. 3D Pattern Synthesis of Time-Modulated Conformal Arrays with a Multiobjective Optimization Approach

    Directory of Open Access Journals (Sweden)

    Wentao Li

    2014-01-01

    Full Text Available This paper addresses the synthesis of the three-dimensional (3D radiation patterns of the time-modulated conformal arrays. Due to the nature of periodic time modulation, harmonic radiation patterns are generated at the multiples of the modulation frequency in time-modulated arrays. Thus, the optimization goal of the time-modulated conformal array includes the optimization of the sidelobe level at the operating frequency and the sideband levels (SBLs at the harmonic frequency, and the design can be regarded as a multiobjective problem. The multiobjective particle swarm optimization (MOPSO is applied to optimize the switch-on instants and pulse durations of the time-modulated conformal array. To significantly reduce the optimization variables, the modified Bernstein polynomial is employed in the synthesis process. Furthermore, dual polarized patch antenna is designed as radiator to achieve low cross-polarization level during the beam scanning. A 12 × 13 (156-element conical conformal microstrip array is simulated to demonstrate the proposed synthesis mechanism, and good results reveal the promising ability of the proposed algorithm in solving the synthesis of the time-modulated conformal arrays problem.

  14. Long-Term Update of NRG Oncology RTOG 0319: A Phase 1 and 2 Trial to Evaluate 3-Dimensional Conformal Radiation Therapy Confined to the Region of the Lumpectomy Cavity for Stage I and II Breast Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Rabinovitch, Rachel, E-mail: rachel.rabinovitch@ucdenver.edu [Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Moughan, Jennifer [NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania (United States); Vicini, Frank [Radiation Oncology, St Joseph Mercy Oakland, Pontiac, Michigan (United States); Pass, Helen [Surgery, Stamford Hospital, Stamford, Connecticut (United States); Wong, John [Medical Physics, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Chafe, Susan [Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta (Canada); Petersen, Ivy [Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Arthur, Douglas W. [Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); White, Julia [Radiation Oncology, The Ohio State University Medical Center, Columbus, Ohio (United States)

    2016-12-01

    Purpose: NRG Oncology RTOG 0319 was the first cooperative group trial in the United States to evaluate 3-dimensional conformal radiation therapy (3D-CRT) accelerated partial breast irradiation (APBI). This report updates secondary endpoints of toxicity and efficacy. Methods and Materials: Patients with stage I or II invasive breast cancer (tumor size ≤3 cm, ≤3 positive lymph nodes, negative margins) were eligible for 3D-CRT APBI: 38.5 Gy in 10 twice-daily fractions. Patient characteristics and treatment details have previously been reported. Adverse events were graded with CTCAE v3.0 (National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0). This analysis updates the rates of ipsilateral breast recurrence (IBR), contralateral breast recurrence, ipsilateral node recurrence (INR), metastatic sites (distant metastases [DM]), mastectomy, disease-free survival, mastectomy-free survival, and overall survival. Results: Of 58 enrolled patients, 52 were eligible, with a median age of 61 years; 94% had stage I cancer and 83% had estrogen receptor positive disease. The median follow-up period was 8 years (minimum-maximum, 1.7-9.0 years). The 7-year estimate of isolated IBR (no DM) was 5.9%. The 7-year estimates of all IBRs, INR, mastectomy rate, and DM were 7.7%, 5.8%, 7.7%, and 7.7%, respectively. All 4 IBRs were invasive, of which 3 had a component within the planning target volume. The patterns of failure were as follows: 3 IBRs, 1 INR, 2 DM, 1 INR plus DM, and 1 IBR plus INR plus DM. The 7-year estimates of mastectomy-free survival, disease-free survival, and overall survival were 71.2%, 71.2%, and 78.8%, respectively. Thirteen patients died: 3 of breast cancer and 10 of other causes. Grade 3 (G3) treatment-related adverse events were reported by 4 patients (7.7%). No G3 pain or pulmonary or cardiac toxicities were reported. Conclusions: This phase 1 and 2 trial of 3D-CRT APBI continues to show durable tumor control and minimal G3

  15. Conformal ghosts on the sphere

    Energy Technology Data Exchange (ETDEWEB)

    Vogeler, Kirsten

    2010-07-16

    This thesis is about the relation of geometry and logarithmic conformal field theories. I consider two different geometric settings: in part I the topological A-model with embedding x:R x S{sup 1}{yields}CP{sup 1}, and in part II conformal, fermionic ghosts on the torus. The A-model can be transformed such that the path integral yields a {delta} distribution on the moduli space of instantons. Integrating out the dependency on S{sup 1}, one obtains Morse theory on the universal cover LCP{sup 1} of loop space. Its low-energy state space can be derived perturbatively in cells of this manifold, and can be modelled by the representations of the chiral de Rham complex. Assuming that the representation theory of the A-model and the chiral de Rham complex are identical, I consider the chiral de Rham complex in the following. The state spaces are local, induced representations of the symmetry generated by the gradient vector field of the Morse function. According to a conjecture of E. Frenkel, A. Losev and N. Nekrasov, a generalization of these local representations as distributions on LCP{sup 1} leads to nonperturbative states of the theory. On these states, the Hamiltonian must be corrected by additional terms. I discuss the representation theory of the nonperturbative states and determine the terms which deform the Hamiltonian. They have a geometric significance as cohomology operators in a complex of globally extended local representation spaces. Eventually, I prove that a logarithmic extension of the chiral de Rham complex corresponds the additional terms in the Hamiltonian. The conformal, fermionic ghosts of part II transform in irreducible representations of the monodromy group Z{sub 2}. I show that the conformal field theory of these fields has to be logarithmically extended as soon as the representations of the monodromy group are allowed to move freely on the parameter space CP{sup 1} backslash {l_brace}0,1,{infinity}{r_brace} of the torus. The triplet model

  16. Conformal Lightweight Antenna Structures for Aeronautical Communication Technologies

    Science.gov (United States)

    Meador, Mary Ann

    2017-01-01

    This project is to develop antennas which enable beyond line of sight (BLOS) command and control for UAVs. We will take advantage of newly assigned provisional Ku-band spectrum for UAVs and use unique antenna designs to avoid interference with ground systems. This will involve designing antennas with high isotropic effective radiated power (EIRP) and ultra-low sidelobes. The antennas will be made with polymer aerogel as a substrate to both reduce weight and improve performance, as demonstrated in an Aero Seedling. In addition, designing the antennas to be conformal to the aircraft fuselage will reduce drag.

  17. Focused conformational sampling in proteins

    Science.gov (United States)

    Bacci, Marco; Langini, Cassiano; Vymětal, Jiří; Caflisch, Amedeo; Vitalis, Andreas

    2017-11-01

    A detailed understanding of the conformational dynamics of biological molecules is difficult to obtain by experimental techniques due to resolution limitations in both time and space. Computer simulations avoid these in theory but are often too short to sample rare events reliably. Here we show that the progress index-guided sampling (PIGS) protocol can be used to enhance the sampling of rare events in selected parts of biomolecules without perturbing the remainder of the system. The method is very easy to use as it only requires as essential input a set of several features representing the parts of interest sufficiently. In this feature space, new states are discovered by spontaneous fluctuations alone and in unsupervised fashion. Because there are no energetic biases acting on phase space variables or projections thereof, the trajectories PIGS generates can be analyzed directly in the framework of transition networks. We demonstrate the possibility and usefulness of such focused explorations of biomolecules with two loops that are part of the binding sites of bromodomains, a family of epigenetic "reader" modules. This real-life application uncovers states that are structurally and kinetically far away from the initial crystallographic structures and are also metastable. Representative conformations are intended to be used in future high-throughput virtual screening campaigns.

  18. Conformal Gauge Transformations in Thermodynamics

    Directory of Open Access Journals (Sweden)

    Alessandro Bravetti

    2015-09-01

    Full Text Available In this work, we show that the thermodynamic phase space is naturally endowed with a non-integrable connection, defined by all of those processes that annihilate the Gibbs one-form, i.e., reversible processes. We argue that such a connection is invariant under re-scalings of the connection one-form, whilst, as a consequence of the non-integrability of the connection, its curvature is not and, therefore, neither is the associated pseudo-Riemannian geometry. We claim that this is not surprising, since these two objects are associated with irreversible processes. Moreover, we provide the explicit form in which all of the elements of the geometric structure of the thermodynamic phase space change under a re-scaling of the connection one-form. We call this transformation of the geometric structure a conformal gauge transformation. As an example, we revisit the change of the thermodynamic representation and consider the resulting change between the two metrics on the thermodynamic phase space, which induce Weinhold’s energy metric and Ruppeiner’s entropy metric. As a by-product, we obtain a proof of the well-known conformal relation between Weinhold’s and Ruppeiner’s metrics along the equilibrium directions. Finally, we find interesting properties of the almost para-contact structure and of its eigenvectors, which may be of physical interest.

  19. A quantitative measure for protein conformational heterogeneity.

    Science.gov (United States)

    Lyle, Nicholas; Das, Rahul K; Pappu, Rohit V

    2013-09-28

    Conformational heterogeneity is a defining characteristic of proteins. Intrinsically disordered proteins (IDPs) and denatured state ensembles are extreme manifestations of this heterogeneity. Inferences regarding globule versus coil formation can be drawn from analysis of polymeric properties such as average size, shape, and density fluctuations. Here we introduce a new parameter to quantify the degree of conformational heterogeneity within an ensemble to complement polymeric descriptors. The design of this parameter is guided by the need to distinguish between systems that couple their unfolding-folding transitions with coil-to-globule transitions and those systems that undergo coil-to-globule transitions with no evidence of acquiring a homogeneous ensemble of conformations upon collapse. The approach is as follows: Each conformation in an ensemble is converted into a conformational vector where the elements are inter-residue distances. Similarity between pairs of conformations is quantified using the projection between the corresponding conformational vectors. An ensemble of conformations yields a distribution of pairwise projections, which is converted into a distribution of pairwise conformational dissimilarities. The first moment of this dissimilarity distribution is normalized against the first moment of the distribution obtained by comparing conformations from the ensemble of interest to conformations drawn from a Flory random coil model. The latter sets an upper bound on conformational heterogeneity thus ensuring that the proposed measure for intra-ensemble heterogeneity is properly calibrated and can be used to compare ensembles for different sequences and across different temperatures. The new measure of conformational heterogeneity will be useful in quantitative studies of coupled folding and binding of IDPs and in de novo sequence design efforts that are geared toward controlling the degree of heterogeneity in unbound forms of IDPs.

  20. Conformal antenna array for ultra-wideband direction-of-arrival estimation

    NARCIS (Netherlands)

    Liberal, I.; Caratelli, D.; Yarovoy, A.

    2011-01-01

    The design and full-wave analysis of an antenna system for ultra-wideband radio direction finding applications is presented. The elliptical dipole antenna is selected as antenna element due to its robust circuital and radiation properties. The influence of the conformal deformation on the antenna

  1. Conformal basis for flat space amplitudes

    Science.gov (United States)

    Pasterski, Sabrina; Shao, Shu-Heng

    2017-09-01

    We study solutions of the Klein-Gordon, Maxwell, and linearized Einstein equations in R1 ,d +1 that transform as d -dimensional conformal primaries under the Lorentz group S O (1 ,d +1 ). Such solutions, called conformal primary wavefunctions, are labeled by a conformal dimension Δ and a point in Rd, rather than an on-shell (d +2 )-dimensional momentum. We show that the continuum of scalar conformal primary wavefunctions on the principal continuous series Δ ∈d/2 +i R of S O (1 ,d +1 ) spans a complete set of normalizable solutions to the wave equation. In the massless case, with or without spin, the transition from momentum space to conformal primary wavefunctions is implemented by a Mellin transform. As a consequence of this construction, scattering amplitudes in this basis transform covariantly under S O (1 ,d +1 ) as d -dimensional conformal correlators.

  2. Reinforcement learning signal predicts social conformity.

    Science.gov (United States)

    Klucharev, Vasily; Hytönen, Kaisa; Rijpkema, Mark; Smidts, Ale; Fernández, Guillén

    2009-01-15

    We often change our decisions and judgments to conform with normative group behavior. However, the neural mechanisms of social conformity remain unclear. Here we show, using functional magnetic resonance imaging, that conformity is based on mechanisms that comply with principles of reinforcement learning. We found that individual judgments of facial attractiveness are adjusted in line with group opinion. Conflict with group opinion triggered a neuronal response in the rostral cingulate zone and the ventral striatum similar to the "prediction error" signal suggested by neuroscientific models of reinforcement learning. The amplitude of the conflict-related signal predicted subsequent conforming behavioral adjustments. Furthermore, the individual amplitude of the conflict-related signal in the ventral striatum correlated with differences in conforming behavior across subjects. These findings provide evidence that social group norms evoke conformity via learning mechanisms reflected in the activity of the rostral cingulate zone and ventral striatum.

  3. Conformational changes in glycine tri- and hexapeptide

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2006-01-01

    conformations and calculated the energy barriers for transitions between them. Using a thermodynamic approach, we have estimated the times of the characteristic transitions between these conformations. The results of our calculations have been compared with those obtained by other theoretical methods...... also investigated the influence of the secondary structure of polypeptide chains on the formation of the potential energy landscape. This analysis has been performed for the sheet and the helix conformations of chains of six amino acids....

  4. Challenges of Agro-Food Standards Conformity

    DEFF Research Database (Denmark)

    Bolwig, Simon; Riisgaard, Lone; Gibbon, Peter

    2013-01-01

    a variety of programmes and projects aimed at supporting standards development and conformity. This article contributes to the critical literature discussing the challenges and potentials of standards conformity and supplies policy recommendations for future interventions. It reports the results...... of a research programme on standards conformity in East Africa. These demonstrate that most interventions underestimate the nature of the challenges faced and that significant impacts are achieved only under rather restricted conditions. The solutions lay not only in more selective support to standard...

  5. Novel conformation of an RNA structural switch.

    Science.gov (United States)

    Kennedy, Scott D; Kierzek, Ryszard; Turner, Douglas H

    2012-11-20

    The RNA duplex, (5'GACGAGUGUCA)(2), has two conformations in equilibrium. The nuclear magnetic resonance solution structure reveals that the major conformation of the loop, 5'GAGU/3'UGAG, is novel and contains two unusual Watson-Crick/Hoogsteen GG pairs with G residues in the syn conformation, two A residues stacked on each other in the center of the helix with inverted sugars, and two bulged-out U residues. The structure provides a benchmark for testing approaches for predicting local RNA structure and a sequence that allows the design of a unique arrangement of functional groups and/or a conformational switch into nucleic acids.

  6. Rotational Spectroscopy Unveils Eleven Conformers of Adrenaline

    Science.gov (United States)

    Cabezas, C.; Cortijo, V.; Mata, S.; Lopez, J. C.; Alonso, J. L.

    2013-06-01

    Recent improvements in our LA-MB-FTMW instrumentation have allowed the characterization of eleven and eight conformers for the neurotransmitters adrenaline and noradrenaline respectively. The observation of this rich conformational behavior is in accordance with the recent observation of seven conformers for dopamine and in sharp contrast with the conformational reduction proposed for catecholamines. C. Cabezas, I. Peña, J. C. López, J. L. Alonso J. Phys. Chem. Lett. 2013, 4, 486. H. Mitsuda, M. Miyazaki, I. B. Nielsen, P. Carcabal,C. Dedonder, C. Jouvet, S. Ishiuchi, M. Fujii J. Phys. Chem. Lett. 2010, 1, 1130.

  7. A Framework for Online Conformance Checking

    DEFF Research Database (Denmark)

    Burattin, Andrea; Carmona, Josep

    2017-01-01

    Conformance checking – a branch of process mining – focuses on establishing to what extent actual executions of a process are in line with the expected behavior of a reference model. Current conformancechecking techniques only allow for a-posteriori analysis: the amount of (non-)conformant behavior...... is quantified after the completion of the process instance. In this paper we propose a framework for online conformance checking: not only do we quantify (non-)conformant behavior as the execution is running, we also restrict the computation to constant time complexity per event analyzed, thus enabling...

  8. Radiation Therapy

    Science.gov (United States)

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  9. Conformable eddy current array delivery

    Science.gov (United States)

    Summan, Rahul; Pierce, Gareth; Macleod, Charles; Mineo, Carmelo; Riise, Jonathan; Morozov, Maxim; Dobie, Gordon; Bolton, Gary; Raude, Angélique; Dalpé, Colombe; Braumann, Johannes

    2016-02-01

    The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path was designed using the KUKA|PRC path planning software. Custom software was then written to interface measurement acquisition from the Eddyfi hardware with the motion control of the robot. Preliminary results and analysis are presented from scanning two canisters.

  10. Technidilaton at the conformal edge

    Science.gov (United States)

    Hashimoto, Michio; Yamawaki, Koichi

    2011-01-01

    Technidilaton (TD) was proposed long ago in the technicolor near criticality/conformality. To reveal the critical behavior of TD, we explicitly compute the nonperturbative contributions to the scale anomaly ⟨θμμ⟩ and to the technigluon condensate ⟨αGμν2⟩, which are generated by the dynamical mass m of the technifermions. Our computation is based on the (improved) ladder Schwinger-Dyson equation, with the gauge coupling α replaced by the two-loop running coupling α(μ) having the Caswell-Banks-Zaks infrared fixed point α*: α(μ)≃α=α* for the infrared region mHaba-Matsuzaki-Yamawaki. The decoupled TD can be a candidate of dark matter.

  11. Approaching Conformality with Ten Flavors

    Energy Technology Data Exchange (ETDEWEB)

    Appelquist, Thomas; Brower, Richard C.; Buchoff, Michael I.; Cheng, Michael; Cohen, Saul D.; Fleming, George T.; Kiskis, Joe; Lin, Meifeng; Na, Heechang; Neil, Ethan T.; Osborn, James C.

    2012-04-01

    We present first results for lattice simulations, on a single volume, of the low-lying spectrum of an SU(3) Yang-Mills gauge theory with N{sub f} = 10 light fermions in the fundamental representation. Fits to the fermion mass dependence of various observables are found to be globally consistent with the hypothesis that this theory is within or just outside the strongly-coupled edge of the conformal window, with mass anomalous dimension {gamma}* {approx} 1 over the range of scales simulated. We stress that we cannot rule out the possibility of spontaneous chiral-symmetry breaking at scales well below our infrared cutoff. We discuss important systematic effects, including finite-volume corrections, and consider directions for future improvement.

  12. Gravitomagnetic effects in conformal gravity

    CERN Document Server

    Said, Jackson Levi; Adami, Kristian Zarb

    2014-01-01

    Gravitomagnetic effects are characterized by two phenomena: first, the geodetic effect which describes the precession of the spin of a gyroscope in a free orbit around a massive object, second, the Lense-Thirring effect which describes the precession of the orbital plane about a rotating source mass. We calculate both these effects in the fourth-order theory of conformal Weyl gravity for the test case of circular orbits. We show that for the geodetic effect a linear term arises which may be interesting for high radial orbits, whereas for the Lense-Thirring effect the additional term has a diminishing effect for most orbits. Circular orbits are also considered in general leading up to a generalization of Kepler's third law.

  13. Radiation dosimetry

    CERN Document Server

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  14. SU-E-T-767: Treatment Planning Study of Prostate Cancer by CyberKnife with Respect to the Urethral Dose

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, H; Mizuno, H; Sumida, I; Otani, Y; Yagi, M; Takashina, M; Suzuki, O; Yoshioka, Y; Koizumi, M; Ogawa, K [Osaka University, Suita, Osaka (Japan)

    2015-06-15

    Purpose: Hypo-fractionated stereotactic body radiation therapy (SBRT) with intensity modulated radiation therapy (IMRT) is nowadays one of the treatment strategies for prostate cancer. There are few reports on planning study of prostate cancer by CyberKnife with respect to the urethral dose because of the invisibility in CT. We have investigated a planning method using fixed collimators with considering dose homogeneity, conformity and urethral dose. Methods: Radiotherapy treatment planning of prostate cancer were under a clinical trial approved by the institutional review board. The prescription dose of 35 Gy were delivered to the PTV in five fractions with the urethral catheter. Urethra position was identified by pretreatment CT and catheter, which was inserted before treatment planning CT and released after the treatment. All plans agreed to the criteria as shown in table 1, and the following constraints were recommended as well: the prescribed iso-dose line should be from 70% to 90%; the total MU should be below 50,000 MU; the minimum MU per beam should be larger than 15 MU; the estimated delivery time (excluding patient setup time) by Multiplan with image time interval of 60 s should be less than 35 min. Collimator size and position were decided as shown in figure 1. Fixed collimator of 15 mm was positioned around urethra and PTV for avoiding high dose of urethra and achieving conformity, and fixed collimator of 30 or 40 were positioned around PTV for achieving dose homogeneity. Results: With this method, all constraints were achieved. (Table 1, Figure 2) Max dose of urethra was ranging from 103.9% to 114.2%, because urethra position was identified by pretreatment CT and urethral catheter. Conclusion: Hypo-fractionated SBRT with IMRT utilizing urethral catheter could be a promising new treatment option for prostate cancer. This work was supported by JSPS Core-to-Core program Number 23003.

  15. Conformations and Conformational Processes of Hexahydrobenzazocines by NMR and DFT Studies.

    Science.gov (United States)

    Musielak, Bogdan; Holak, Tad A; Rys, Barbara

    2015-09-18

    Conformational processes that occur in hexahydrobenzazocines have been studied with the (1)H and (13)C dynamic nuclear magnetic resonance (DNMR) spectroscopy. The coalescence effects are assigned to two different conformational processes: the ring-inversion of the ground-state conformations and the interconversion between two different conformers. The barriers for these processes are in the range of 42-52 and 42-43 kJ mol(-1), respectively. Molecular modeling on the density functional theory (DFT) level and the gauge invariant atomic orbitals (GIAO)-DFT calculations of isotropic shieldings and coupling constants for the set of low-energy conformations were compared with the experimental NMR data. The ground-state of all compounds in solution is the boat-chair (BC) conformation. The BC form adopts two different conformations because the nitrogen atom can be in the boat or chair parts of the BC structure. These two conformers are engaged in the interconversion process.

  16. Spontaneous breaking of conformal invariance in theories of conformally coupled matter and Weyl gravity

    OpenAIRE

    Edery, A.; Fabbri, Luca; Paranjape, M. B.

    2006-01-01

    We study the theory of Weyl conformal gravity with matter degrees of freedom in a conformally invariant interaction. Specifically, we consider a triplet of scalar fields and SO(3) non-abelian gauge fields, i.e. the Georgi-Glashow model conformally coupled to Weyl gravity. We show that the equations of motion admit solutions spontaneously breaking the conformal symmetry and the gauge symmetry, providing a mechanism for supplying a scale in the theory. The vacuum solution corresponds to anti-de...

  17. The butane condensed matter conformational problem

    NARCIS (Netherlands)

    Weber, A.C.J.; de Lange, C.A.; Meerts, W.L.; Burnell, E.E.

    2010-01-01

    From the dipolar couplings of orientationally ordered n-butane obtained by NMR spectroscopy we have calculated conformer probabilities using the modified Chord (Cd) and Size-and-Shape (CI) models to estimate the conformational dependence of the order matrix. All calculation methods make use of

  18. Conformity to Peer Pressure in Preschool Children

    Science.gov (United States)

    Haun, Daniel B. M.; Tomasello, Michael

    2011-01-01

    Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2 and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously erroneous but unanimous…

  19. Group Cohesiveness, Deviation, Stress, and Conformity

    Science.gov (United States)

    1993-08-11

    productivity. ~ Relations, I. 599-519 . Blake , R. R., & Mouton , J. 5, (1961) . Conformity. resistance, and conversion. In I. A. Berg , & B. M. Bass...conversion ( Blake & HoutQn. 1961). Conformity without a true change in private acceptance has been termed compliance (Kiesler, 1969 ; Kiesler

  20. Chaotropes trigger conformational rearrangements differently in ...

    Indian Academy of Sciences (India)

    SHREYASI ASTHANA

    Abstract. Concanavalin A (ConA) is a plant lectin having industrial and biological applications. Concanavalin. A changes conformation upon exposure to different stress conditions, like exposure to sodium dodecyl sulphate, guanidine hydrochloride, varying hydronium ion potential, etc. The conformational changes were ...

  1. Asymptotic symmetry algebra of conformal gravity

    Science.gov (United States)

    Irakleidou, Maria; Lovrekovic, Iva

    2017-11-01

    We compute asymptotic symmetry algebras of conformal gravity. Due to more general boundary conditions allowed in conformal gravity in comparison to those in Einstein gravity, we can classify the corresponding algebras. The highest algebra for nontrivial boundary conditions is five dimensional and it leads to global geon solution with nonvanishing charges.

  2. Conformity to the Surviving Sepsis Campaign International ...

    African Journals Online (AJOL)

    They had moderate conformity rates for blood cultures prior to administering antibiotics (57%) and administration of antibiotics within first hour of recognition of septic shock (54%). There was high conformity rate to the glucose control policy (81%), use of protective lung strategy in acute lung injury/Acute respiratory distress ...

  3. Conformation of hindered piperidines: Spectroscopic evidence for ...

    Indian Academy of Sciences (India)

    Administrator

    C NMR; conformational analysis; boat forms. 1. Introduction. Many piperidine derivatives are found to possess pharmacological activity and form an essential part of the molecular structure of important drugs. 1. Most of the piperidine precursors are known to exist in chair conformation. Electron withdrawing groups. (–NO ...

  4. Conformational changes to deamidated wheat gliadins and b-casein upon adsorption to oil-water emulsion interfaces

    DEFF Research Database (Denmark)

    Wong, Benjamin T.; Zhai, Jiali; Hoffmann, Søren Vrønning

    2012-01-01

    The conformation of deamidated gliadins and b-casein in solution and adsorbed at the interface of oil-inwater emulsions was studied using synchrotron radiation circular dichroism (SRCD) and front-facefluorescence spectroscopy. Deamidation led to partial unfolding of gliadins in solution. The a...... in the adsorbed state. Our results demonstrate that conformational re-arrangement of proteins upon adsorption to emulsion interfaces is dependent not only on the hydrophobicity of the oil phase, but more importantly on the conformational flexibility of the protein....

  5. Wormholes in conformal gravity arXiv

    CERN Document Server

    Hohmann, Manuel; Raidal, Martti; Veermäe, Hardi

    We present a new class of solutions for static spherically symmetric wormhole spacetimes in conformal gravity and outline a detailed method for their construction. As an explicit example, we construct a class of traversable and non-traversable wormholes that are locally conformal to Schwarzschild-(anti) de Sitter spacetimes. These wormhole spacetimes are exact vacuum solutions in, but not being limited to, Weyl gravity and conformal scalar-tensor theories. Importantly, the method implies that every conformal gravity theory with local field equations will trivially contain wormholes without the need for exotic matter. Applying those results on gravitational theories that possess conformal symmetry in the ultraviolet regime, the central singularities of black holes can be replaced with wormhole throats. We speculate on possible phenomenological consequences.

  6. Conformational structures in dry ionomers

    Science.gov (United States)

    Allahyarov, Elshad; Taylor, Philip

    2007-03-01

    The molecular architecture of polymer electrolyte membranes (PEM), which consist of hydrophobic and hydrophilic segments, leads to its own self-assembled structure through a partial phase segregation. Controlling these structures is necessary for improving the performance of fuel cells. We have used computer simulation to analyze the relationship between the hydrophilic cluster structure and the parameters describing the pendant side chains in dry Nafion-like materials. We investigate the morphology of a dry PEM system within different coarse-grained models: a free-proton model, a dipolar model for side chains, and a branched-chain model. We conclude that the free-proton model, where the proton-proton correlations are decoupled from the sulfonate-sulfonate correlations, has the potential to explain the experimentally observed conformational structures of PEM. We find that the geometry of domains with a high concentration of sulfonate groups depends only weakly on the form of the distance-dependent dielectric permittivity, but strongly depends on the partial charge and monomeric unit sequence distribution along the ionomer chain. We predict a nanophase separation with a lamellar-like morphology in ionomers carrying a divalent salt.

  7. 47 CFR 2.1072 - Limitation on Declaration of Conformity.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Limitation on Declaration of Conformity. 2.1072... Conformity § 2.1072 Limitation on Declaration of Conformity. (a) The Declaration of Conformity signifies that...'s rules. (b) A Declaration of Conformity by the responsible party is effective until a termination...

  8. PubChem3D: Similar conformers

    Directory of Open Access Journals (Sweden)

    Bolton Evan E

    2011-05-01

    Full Text Available Abstract Background PubChem is a free and open public resource for the biological activities of small molecules. With many tens of millions of both chemical structures and biological test results, PubChem is a sizeable system with an uneven degree of available information. Some chemical structures in PubChem include a great deal of biological annotation, while others have little to none. To help users, PubChem pre-computes "neighboring" relationships to relate similar chemical structures, which may have similar biological function. In this work, we introduce a "Similar Conformers" neighboring relationship to identify compounds with similar 3-D shape and similar 3-D orientation of functional groups typically used to define pharmacophore features. Results The first two diverse 3-D conformers of 26.1 million PubChem Compound records were compared to each other, using a shape Tanimoto (ST of 0.8 or greater and a color Tanimoto (CT of 0.5 or greater, yielding 8.16 billion conformer neighbor pairs and 6.62 billion compound neighbor pairs, with an average of 253 "Similar Conformers" compound neighbors per compound. Comparing the 3-D neighboring relationship to the corresponding 2-D neighboring relationship ("Similar Compounds" for molecules such as caffeine, aspirin, and morphine, one finds unique sets of related chemical structures, providing additional significant biological annotation. The PubChem 3-D neighboring relationship is also shown to be able to group a set of non-steroidal anti-inflammatory drugs (NSAIDs, despite limited PubChem 2-D similarity. In a study of 4,218 chemical structures of biomedical interest, consisting of many known drugs, using more diverse conformers per compound results in more 3-D compound neighbors per compound; however, the overlap of the compound neighbor lists per conformer also increasingly resemble each other, being 38% identical at three conformers and 68% at ten conformers. Perhaps surprising is that the average

  9. C-metric solution for conformal gravity with a conformally coupled scalar field

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Kun, E-mail: mengkun@tjpu.edu.cn [School of Science, Tianjin Polytechnic University, Tianjin 300387 (China); Zhao, Liu, E-mail: lzhao@nankai.edu.cn [School of Physics, Nankai University, Tianjin 300071 (China)

    2017-02-15

    The C-metric solution of conformal gravity with a conformally coupled scalar field is presented. The solution belongs to the class of Petrov type D spacetimes and is conformal to the standard AdS C-metric appeared in vacuum Einstein gravity. For all parameter ranges, we identify some of the physically interesting static regions and the corresponding coordinate ranges. The solution may contain a black hole event horizon, an acceleration horizon, either of which may be cut by the conformal infinity or be hidden behind the conformal infinity. Since the model is conformally invariant, we also discussed the possible effects of the conformal gauge choices on the structure of the spacetime.

  10. Efficiency of Stereotactic Conformal Radiotherapy in Lung Metastases with Active Breathing Control

    Directory of Open Access Journals (Sweden)

    Olga Yu. Anikeeva, PhD

    2013-06-01

    Full Text Available Twenty four patients with lung metastases underwent radiosurgery treatment between October 2010 and December 2012. Stereotactic conformal high-dose radiation therapy with Active Breathing Control (ABC was conducted using the volumetric modulated arc therapy (VMAT technique. The median overall follow-up was 18 months (range 6-24 months, overall survival was 75%, and local control rate was 92%. The median time to progression was 4 months (range 1-18 months.There have been no cases of leucopenia, radiation esophagitis, mediastinitis or severe acute radiation pneumonitis. The late radiation effects Grade 2, according to the LENT SOMA scales, was observed in one patient (4%. The results of this study indicate that the usage of the stereotactic high-dose radiation therapy with ABC is safe and effective in the treatment of lung metastases.

  11. Conformational Properties of β-PrP*

    Science.gov (United States)

    Hosszu, Laszlo L. P.; Trevitt, Clare R.; Jones, Samantha; Batchelor, Mark; Scott, David J.; Jackson, Graham S.; Collinge, John; Waltho, Jonathan P.; Clarke, Anthony R.

    2009-01-01

    Prion propagation involves a conformational transition of the cellular form of prion protein (PrPC) to a disease-specific isomer (PrPSc), shifting from a predominantly α-helical conformation to one dominated by β-sheet structure. This conformational transition is of critical importance in understanding the molecular basis for prion disease. Here, we elucidate the conformational properties of a disulfide-reduced fragment of human PrP spanning residues 91–231 under acidic conditions, using a combination of heteronuclear NMR, analytical ultracentrifugation, and circular dichroism. We find that this form of the protein, which similarly to PrPSc, is a potent inhibitor of the 26 S proteasome, assembles into soluble oligomers that have significant β-sheet content. The monomeric precursor to these oligomers exhibits many of the characteristics of a molten globule intermediate with some helical character in regions that form helices I and III in the PrPC conformation, whereas helix II exhibits little evidence for adopting a helical conformation, suggesting that this region is a likely source of interaction within the initial phases of the transformation to a β-rich conformation. This precursor state is almost as compact as the folded PrPC structure and, as it assembles, only residues 126–227 are immobilized within the oligomeric structure, leaving the remainder in a mobile, random-coil state. PMID:19369250

  12. Conformational properties of beta-PrP.

    Science.gov (United States)

    Hosszu, Laszlo L P; Trevitt, Clare R; Jones, Samantha; Batchelor, Mark; Scott, David J; Jackson, Graham S; Collinge, John; Waltho, Jonathan P; Clarke, Anthony R

    2009-08-14

    Prion propagation involves a conformational transition of the cellular form of prion protein (PrPC) to a disease-specific isomer (PrPSc), shifting from a predominantly alpha-helical conformation to one dominated by beta-sheet structure. This conformational transition is of critical importance in understanding the molecular basis for prion disease. Here, we elucidate the conformational properties of a disulfide-reduced fragment of human PrP spanning residues 91-231 under acidic conditions, using a combination of heteronuclear NMR, analytical ultracentrifugation, and circular dichroism. We find that this form of the protein, which similarly to PrPSc, is a potent inhibitor of the 26 S proteasome, assembles into soluble oligomers that have significant beta-sheet content. The monomeric precursor to these oligomers exhibits many of the characteristics of a molten globule intermediate with some helical character in regions that form helices I and III in the PrPC conformation, whereas helix II exhibits little evidence for adopting a helical conformation, suggesting that this region is a likely source of interaction within the initial phases of the transformation to a beta-rich conformation. This precursor state is almost as compact as the folded PrPC structure and, as it assembles, only residues 126-227 are immobilized within the oligomeric structure, leaving the remainder in a mobile, random-coil state.

  13. On functional representations of the conformal algebra

    Energy Technology Data Exchange (ETDEWEB)

    Rosten, Oliver J.

    2017-07-15

    Starting with conformally covariant correlation functions, a sequence of functional representations of the conformal algebra is constructed. A key step is the introduction of representations which involve an auxiliary functional. It is observed that these functionals are not arbitrary but rather must satisfy a pair of consistency equations corresponding to dilatation and special conformal invariance. In a particular representation, the former corresponds to the canonical form of the exact renormalization group equation specialized to a fixed point whereas the latter is new. This provides a concrete understanding of how conformal invariance is realized as a property of the Wilsonian effective action and the relationship to action-free formulations of conformal field theory. Subsequently, it is argued that the conformal Ward Identities serve to define a particular representation of the energy-momentum tensor. Consistency of this construction implies Polchinski's conditions for improving the energy-momentum tensor of a conformal field theory such that it is traceless. In the Wilsonian approach, the exactly marginal, redundant field which generates lines of physically equivalent fixed points is identified as the trace of the energy-momentum tensor. (orig.)

  14. Spectra of conformal sigma models

    Energy Technology Data Exchange (ETDEWEB)

    Tlapak, Vaclav

    2015-04-15

    In this thesis the spectra of conformal sigma models defined on (generalized) symmetric spaces are analysed. The spaces where sigma models are conformal without the addition of a Wess-Zumino term are supermanifolds, in other words spaces that include fermionic directions. After a brief review of the general construction of vertex operators and the background field expansion, we compute the diagonal terms of the one-loop anomalous dimensions of sigma models on semi-symmetric spaces. We find that the results are formally identical to the symmetric case. However, unlike for sigma models on symmetric spaces, off diagonal terms that lead to operator mixing are also present. These are not computed here. We then present a detailed analysis of the one-loop spectrum of the supersphere S{sup 3} {sup vertical} {sup stroke} {sup 2} sigma model as one of the simplest examples. The analysis illustrates the power and simplicity of the construction. We use this data to revisit a duality with the OSP(4 vertical stroke 2) Gross-Neveu model that was proposed by Candu and Saleur. With the help of a recent all-loop result for the anomalous dimension of (1)/(2)BPS operators of Gross-Neveu models, we are able to recover the entire zero-mode spectrum of the supersphere model. We also argue that the sigma model constraints and its equations of motion are implemented correctly in the Gross-Neveu model, including the one-loop data. The duality is further supported by a new all-loop result for the anomalous dimension of the ground states of the sigma model. However, higher-gradient operators cannot be completely recovered. It is possible that this discrepancy is related to a known instability of the sigma model. The instability of sigma models is due to symmetry preserving high-gradient operators that become relevant at arbitrarily small values of the coupling. This feature has been observed long ago in one-loop calculations of the O(N)-vector model and soon been realized to be a generic

  15. Multiresolution Computation of Conformal Structures of Surfaces

    Directory of Open Access Journals (Sweden)

    Xianfeng Gu

    2003-10-01

    Full Text Available An efficient multiresolution method to compute global conformal structures of nonzero genus triangle meshes is introduced. The homology, cohomology groups of meshes are computed explicitly, then a basis of harmonic one forms and a basis of holomorphic one forms are constructed. A progressive mesh is generated to represent the original surface at different resolutions. The conformal structure is computed for the coarse level first, then used as the estimation for that of the finer level, by using conjugate gradient method it can be refined to the conformal structure of the finer level.

  16. Conformal field theory with gauge symmetry

    CERN Document Server

    Ueno, Kenji

    2008-01-01

    This book presents a systematic approach to conformal field theory with gauge symmetry from the point of view of complex algebraic geometry. After presenting the basic facts of the theory of compact Riemann surfaces and the representation theory of affine Lie algebras in Chapters 1 and 2, conformal blocks for pointed Riemann surfaces with coordinates are constructed in Chapter 3. In Chapter 4 the sheaf of conformal blocks associated to a family of pointed Riemann surfaces with coordinates is constructed, and in Chapter 5 it is shown that this sheaf supports a projective flat connection-one of

  17. Conformable Fractional Nikiforov—Uvarov Method

    Science.gov (United States)

    Karayer, H.; Demirhan, D.; Büyükkılıç, F.

    2016-07-01

    We introduce conformable fractional Nikiforov—Uvarov (NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solutions of Schrödinger equation (SE) for certain potentials in quantum mechanics, this method is carried into the domain of fractional calculus to obtain the solutions of fractional SE. In order to demonstrate the applicability of the conformable fractional NU method, we solve fractional SE for harmonic oscillator potential, Woods—Saxon potential, and Hulthen potential.

  18. Conformal Gravity: Dark Matter and Dark Energy

    Directory of Open Access Journals (Sweden)

    Robert K. Nesbet

    2013-01-01

    Full Text Available This short review examines recent progress in understanding dark matter, dark energy, and galactic halos using theory that departs minimally from standard particle physics and cosmology. Strict conformal symmetry (local Weyl scaling covariance, postulated for all elementary massless fields, retains standard fermion and gauge boson theory but modifies Einstein–Hilbert general relativity and the Higgs scalar field model, with no new physical fields. Subgalactic phenomenology is retained. Without invoking dark matter, conformal gravity and a conformal Higgs model fit empirical data on galactic rotational velocities, galactic halos, and Hubble expansion including dark energy.

  19. The decomposition of global conformal invariants

    CERN Document Server

    Alexakis, Spyros

    2012-01-01

    This book addresses a basic question in differential geometry that was first considered by physicists Stanley Deser and Adam Schwimmer in 1993 in their study of conformal anomalies. The question concerns conformally invariant functionals on the space of Riemannian metrics over a given manifold. These functionals act on a metric by first constructing a Riemannian scalar out of it, and then integrating this scalar over the manifold. Suppose this integral remains invariant under conformal re-scalings of the underlying metric. What information can one then deduce about the Riemannian scalar? Dese

  20. Conformal invariance in quantum field theory

    CERN Document Server

    Todorov, Ivan T; Petkova, Valentina B

    1978-01-01

    The present volume is an extended and up-to-date version of two sets of lectures by the first author and it reviews more recent work. The notes aim to present a self-contained exposition of a constructive approach to conformal invariant quantum field theory. Other parts in application of the conformal group to quantum physics are only briefly mentioned. The relevant mathematical material (harmonic analysis on Euclidean conformal groups) is briefly summarized. A new exposition of physical applications is given, which includes an explicit construction of the vacuum operator product expansion for the free zero mass fields.

  1. Static validation of licence conformance policies

    DEFF Research Database (Denmark)

    Hansen, Rene Rydhof; Nielson, Flemming; Nielson, Hanne Riis

    2008-01-01

    Policy conformance is a security property gaining importance due to commercial interest like Digital Rights Management. It is well known that static analysis can be used to validate a number of more classical security policies, such as discretionary and mandatory access control policies, as well...... as communication protocols using symmetric and asymmetric cryptography. In this work we show how to develop a Flow Logic for validating the conformance of client software with respect to a licence conformance policy. Our approach is sufficiently flexible that it extends to fully open systems that can admit new...

  2. Scalar scattering via conformal higher spin exchange

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Euihun [School of Physics and Astronomy,Seoul National University, Seoul 151-747 (Korea, Republic of); Gauge, Gravity & Strings, Center for Theoretical Physics of the Universe,Institute for Basic Sciences, Daejeon 34047 (Korea, Republic of); Nakach, Simon; Tseytlin, Arkady A. [Theoretical physics group, Blackett Laboratory,Imperial College London, SW7 2AZ (United Kingdom)

    2016-02-18

    Theories containing infinite number of higher spin fields require a particular definition of summation over spins consistent with their underlying symmetries. We consider a model of massless scalars interacting (via bilinear conserved currents) with conformal higher spin fields in flat space. We compute the tree-level four-scalar scattering amplitude using a natural prescription for summation over an infinite set of conformal higher spin exchanges and find that it vanishes. Independently, we show that the vanishing of the scalar scattering amplitude is, in fact, implied by the global conformal higher spin symmetry of this model. We also discuss one-loop corrections to the four-scalar scattering amplitude.

  3. Conformal treatment planning for interstitial brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, G. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Hebbinghaus, D. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Dennert, P. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Kohr, P. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Wilhelm, R. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie); Kimmig, B. [Kiel Univ. (Germany). Klinik fuer Strahlentherapie (Radioonkologie)

    1996-09-01

    Quality of a brachytherapy application depends on the choice of the target volume, on the dose distribution homogeneity and radiation injury on critical tissue, which should be postulated by advanced brachytherapy treatment planning systems. Basic imaging method for conformal treatment planning is the cross-sectional imaging. The clinical applicatibility of a new type 3D planning system using CT and/or MRT-simulation or US-simulation for planning purposes was studied. The planning system developed at Kiel University differs from usual brachytherapy planning systems because of the obligatory use of cross-sectional imaging as basic imaging method for reconstruction of structures of interest. Dose distribution and normal anatomy can be visualized on each CT/MRT/US slice as well as coronal, sagittal, axial and free chosen reconstructions (3D), as well as dose-volume histogram curves and special colour-coded visualization of dose homogeneity in the target can be analyzed. Because of the experience in the clinical routine, as well as on the base of 30 simultaneous planning procedures on both 2D (semi-3D) and 3D planning systems we observed similar time consumption. Advantages of 3D planning were the better interpretation of target delineation, delineation of critical structures as well as dose distribution, causing more accurate volume optimisation of dose distribution. Conformal brachytherapy treatment planning for interstitial brachytherapy means significant advantages for the clinical routine compared to 2D or semi-3D methods. (orig.) [Deutsch] Die Qualitaet einer Brachytherapieapplikation ist abhaengig von der Zielvolumenwahl, der homogenen Dosisverteilung und der Schonung kritischer Organe. Diese Voraussetzungen koennen am besten mit Hilfe eines 3D-Planungssystem erfuellt werden. Als Planungsvorlage fuer die Konformationstherapieplanung sind am besten Schnittbilder (CT, MRT, US) geeignet. Es wurde die Anwendbarkeit eines auf CT- (oder MRT-)Simulation oder geeignete

  4. Radiation Therapy: Professions in Radiation Therapy

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Professions in Radiation Therapy Radiation Oncologist Therapeutic Medical Physicist Radiation Therapist Dosimetrist Radiation Oncology Nurse Social Worker Dietitian Radiation Oncologist Radiation oncologists are physicians who oversee the ...

  5. Nonconformal Fluctuations in Radiation Dominated Anisotropic ...

    Indian Academy of Sciences (India)

    tribpo

    the non-conformal quantum fluctuations (of expansion and shear) and axisymmetric singularity case in radiation dominated anisotropic cosmology. We show that near the classical singularity the quantum fluctuations tend to diverge. Key words. Quantum Cosmology—Anisotropic universes. 1. Introduction. It has been ...

  6. Aluminized fiberglass insulation conforms to curved surfaces

    Science.gov (United States)

    1966-01-01

    Layers of fiber glass with outer reflective films of vacuum-deposited aluminum or other reflective metal, provide thermal insulation which conforms to curved surfaces. This insulation has good potential for cryogenic systems.

  7. Timed Safety Automata and Logic Conformance

    National Research Council Canada - National Science Library

    Young, Frank

    1999-01-01

    Timed Logic Conformance (TLC) is used to verify the behavioral and timing properties of detailed digital circuits against abstract circuit specifications when both are modeled as Timed Safety Automata (TSA...

  8. Conformal Carroll groups and BMS symmetry

    OpenAIRE

    Duval, C.; Gibbons, G W; Horvathy, P. A.

    2014-01-01

    The Bondi-Metzner-Sachs (BMS) group is shown to be the conformal extension of Levy-Leblond's "Carroll" group. Further extension to the Newman-Unti (NU) group is also discussed in the Carroll framework.

  9. General Information for Transportation and Conformity

    Science.gov (United States)

    Transportation conformity is required by the Clean Air Act section 176(c) (42 U.S.C. 7506(c)) to ensure that federal funding and approval are given to highway and transit projects that are consistent with SIP.

  10. A probabilistic model of RNA conformational space

    DEFF Research Database (Denmark)

    Frellsen, Jes; Moltke, Ida; Thiim, Martin

    2009-01-01

    The increasing importance of non-coding RNA in biology and medicine has led to a growing interest in the problem of RNA 3-D structure prediction. As is the case for proteins, RNA 3-D structure prediction methods require two key ingredients: an accurate energy function and a conformational sampling...... procedure. Both are only partly solved problems. Here, we focus on the problem of conformational sampling. The current state of the art solution is based on fragment assembly methods, which construct plausible conformations by stringing together short fragments obtained from experimental structures. However...... efficient sampling of RNA conformations in continuous space, and with associated probabilities. We show that the model captures several key features of RNA structure, such as its rotameric nature and the distribution of the helix lengths. Furthermore, the model readily generates native-like 3-D...

  11. Social conformity despite individual preferences for distinctiveness.

    Science.gov (United States)

    Smaldino, Paul E; Epstein, Joshua M

    2015-03-01

    We demonstrate that individual behaviours directed at the attainment of distinctiveness can in fact produce complete social conformity. We thus offer an unexpected generative mechanism for this central social phenomenon. Specifically, we establish that agents who have fixed needs to be distinct and adapt their positions to achieve distinctiveness goals, can nevertheless self-organize to a limiting state of absolute conformity. This seemingly paradoxical result is deduced formally from a small number of natural assumptions and is then explored at length computationally. Interesting departures from this conformity equilibrium are also possible, including divergence in positions. The effect of extremist minorities on these dynamics is discussed. A simple extension is then introduced, which allows the model to generate and maintain social diversity, including multimodal distinctiveness distributions. The paper contributes formal definitions, analytical deductions and counterintuitive findings to the literature on individual distinctiveness and social conformity.

  12. Reciprocity Outperforms Conformity to Promote Cooperation.

    Science.gov (United States)

    Romano, Angelo; Balliet, Daniel

    2017-10-01

    Evolutionary psychologists have proposed two processes that could give rise to the pervasiveness of human cooperation observed among individuals who are not genetically related: reciprocity and conformity. We tested whether reciprocity outperformed conformity in promoting cooperation, especially when these psychological processes would promote a different cooperative or noncooperative response. To do so, across three studies, we observed participants' cooperation with a partner after learning (a) that their partner had behaved cooperatively (or not) on several previous trials and (b) that their group members had behaved cooperatively (or not) on several previous trials with that same partner. Although we found that people both reciprocate and conform, reciprocity has a stronger influence on cooperation. Moreover, we found that conformity can be partly explained by a concern about one's reputation-a finding that supports a reciprocity framework.

  13. Film dosimetry in conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Danciu, C.; Proimos, B.S. [Patras Univ. (Greece). Dept. of Medical Physics

    1995-12-01

    Dosimetry, through a film sandwiched in a transverse cross-section of a solid phantom, is a method of choice in Conformal Radiotherapy because: (a) the blackness (density) of the film at each point offers a measure of the total dose received at that point, and (b) the film is easily calibrated by exposing a film strip in the same cross-section, through a stationary field. The film must therefore have the following properties: (a) it must be slow, in order not to be overexposed, even at a therapeutic dose of 200 cGy, and (b) the response of the film (density versus dose curve) must be independent of the photon energy spectrum. A few slow films were compared. It was found that the Kodak X-Omat V for therapy verification was the best choice. To investigate whether the film response was independent of the photon energy, response curves for six depths, starting from the depth of maximum dose to the depth of 25 cm, in solid phantom were derived. The vertical beam was perpendicular to the anterior surface of the phantom, which was at the distance of 100 cm from the source and the field was 15x15 cm at that distance. This procedure was repeated for photon beams emitted by a Cobalt-60 unit, two 6 MV and 15 MV Linear Accelerators, as well as a 45 MV Betatron. For each of those four different beams the film response was the same for all six depths. The results, as shown in the diagrams, are very satisfactory. The response curve under a geometry similar to that actually applied, when the film is irradiated in a transverse cross-section of the phantom, was derived. The horizontal beam was almost parallel (angle of 85) to the plane of the film. The same was repeated with the central ray parallel to the film (angle 90) and at a distance of 1.5 cm from the horizontal film. The field size was again 15x15 at the lateral entrance surface of the beam. The response curves remained the same, as when the beam was perpendicular to the films.

  14. A novel conformational switch for electron transfer

    Indian Academy of Sciences (India)

    Administrator

    The soluble fraction of the sub-unit II cloned and over-expressed in E. coli has been studied as a model of the electron entry site (CuA) of cytochrome oxidase. The CuA site in the sub-unit II was found to exist in a pH induced conformational equilibrium with a high pH conformer being preferred at elevated temperatures.

  15. Does gender diversity promote non-conformity?

    OpenAIRE

    Amini, Makan; Ekström, Mathias; Ellingsen, Tore; Johannesson, Magnus; Strömsten, Fredrik

    2015-01-01

    Failure to express minority views may distort the behavior of company boards, committees, juries, and other decision-making bodies. Devising a new experimental procedure to measure such conformity in a judgment task, we compare the degree of conformity in groups with varying gender composition. Overall, our experiments offer little evidence that gender composition affects expression of minority views. A robust finding is that a subject's lack of ability predicts both a true propensity to acce...

  16. The research of conformal optical design

    Science.gov (United States)

    Li, Lin; Li, Yan; Huang, Yi-fan; Du, Bao-lin

    2009-07-01

    Conformal optical domes are characterized as having external more elongated optical surfaces that are optimized to minimize drag, increased missile velocity and extended operational range. The outer surface of the conformal domes typically deviate greatly from spherical surface descriptions, so the inherent asymmetry of conformal surfaces leads to variations in the aberration content presented to the optical sensor as it is gimbaled across the field of regard, which degrades the sensor's ability to properly image targets of interest and then undermine the overall system performance. Consequently, the aerodynamic advantages of conformal domes cannot be realized in practical systems unless the dynamic aberration correction techniques are developed to restore adequate optical imaging capabilities. Up to now, many optical correction solutions have been researched in conformal optical design, including static aberrations corrections and dynamic aberrations corrections. There are three parts in this paper. Firstly, the combination of static and dynamic aberration correction is introduced. A system for correcting optical aberration created by a conformal dome has an outer surface and an inner surface. The optimization of the inner surface is regard as the static aberration correction; moreover, a deformable mirror is placed at the position of the secondary mirror in the two-mirror all reflective imaging system, which is the dynamic aberration correction. Secondly, the using of appropriate surface types is very important in conformal dome design. Better performing optical systems can result from surface types with adequate degrees of freedom to describe the proper corrector shape. Two surface types and the methods of using them are described, including Zernike polynomial surfaces used in correct elements and user-defined surfaces used in deformable mirror (DM). Finally, the Adaptive optics (AO) correction is presented. In order to correct the dynamical residual aberration

  17. Effective Conformal Descriptions of Black Hole Entropy

    Directory of Open Access Journals (Sweden)

    Steven Carlip

    2011-07-01

    Full Text Available It is no longer considered surprising that black holes have temperatures and entropies. What remains surprising, though, is the universality of these thermodynamic properties: their exceptionally simple and general form, and the fact that they can be derived from many very different descriptions of the underlying microscopic degrees of freedom. I review the proposal that this universality arises from an approximate conformal symmetry, which permits an effective “conformal dual” description that is largely independent of the microscopic details.

  18. Divergence-type theory of conformal fields

    OpenAIRE

    Peralta-Ramos, J.; Calzetta, E.

    2009-01-01

    We present a nonlinear hydrodynamical description of a conformal plasma within the framework of divergence-type theories (DTTs), which are not based on a gradient expansion. We compare the equations of the DTT and the second-order theory (based on conformal invariants), for the case of Bjorken ow. The approach to ideal hydrodynamics is faster in the DTT, indicating that our results can be useful in the study of early-time dynamics in relativistic heavy-ion collisions.

  19. On being loud and proud: non-conformity and counter-conformity to group norms.

    Science.gov (United States)

    Hornsey, Matthew J; Majkut, Louise; Terry, Deborah J; McKimmie, Blake M

    2003-09-01

    Most experiments on conformity have been conducted in relation to judgments of physical reality; surprisingly few papers have experimentally examined the influence of group norms on social issues with a moral component. In response to this, participants were told that they were either in a minority or in a majority relative to their university group in terms of their attitudes toward recognition of gay couples in law (Expt 1: N = 205) and a government apology to Aborigines (Expt 2: N = 110). In both experiments, it was found that participants who had a weak moral basis for their attitude conformed to the group norm on private behaviours. In contrast, those who had a strong moral basis for their attitude showed non-conformity on private behaviours and counter-conformity on public behaviours. Incidences of non-conformity and counter-conformity are discussed with reference to theory and research on normative influence.

  20. Conformational proofreading: the impact of conformational changes on the specificity of molecular recognition.

    Directory of Open Access Journals (Sweden)

    Yonatan Savir

    Full Text Available To perform recognition, molecules must locate and specifically bind their targets within a noisy biochemical environment with many look-alikes. Molecular recognition processes, especially the induced-fit mechanism, are known to involve conformational changes. This raises a basic question: Does molecular recognition gain any advantage by such conformational changes? By introducing a simple statistical-mechanics approach, we study the effect of conformation and flexibility on the quality of recognition processes. Our model relates specificity to the conformation of the participant molecules and thus suggests a possible answer: Optimal specificity is achieved when the ligand is slightly off target; that is, a conformational mismatch between the ligand and its main target improves the selectivity of the process. This indicates that deformations upon binding serve as a conformational proofreading mechanism, which may be selected for via evolution.

  1. Conformal field theories and tensor categories. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Chengming [Nankai Univ., Tianjin (China). Chern Institute of Mathematics; Fuchs, Juergen [Karlstad Univ. (Sweden). Theoretical Physics; Huang, Yi-Zhi [Rutgers Univ., Piscataway, NJ (United States). Dept. of Mathematics; Kong, Liang [Tsinghua Univ., Beijing (China). Inst. for Advanced Study; Runkel, Ingo; Schweigert, Christoph (eds.) [Hamburg Univ. (Germany). Dept. of Mathematics

    2014-08-01

    First book devoted completely to the mathematics of conformal field theories, tensor categories and their applications. Contributors include both mathematicians and physicists. Some long expository articles are especially suitable for beginners. The present volume is a collection of seven papers that are either based on the talks presented at the workshop ''Conformal field theories and tensor categories'' held June 13 to June 17, 2011 at the Beijing International Center for Mathematical Research, Peking University, or are extensions of the material presented in the talks at the workshop. These papers present new developments beyond rational conformal field theories and modular tensor categories and new applications in mathematics and physics. The topics covered include tensor categories from representation categories of Hopf algebras, applications of conformal field theories and tensor categories to topological phases and gapped systems, logarithmic conformal field theories and the corresponding non-semisimple tensor categories, and new developments in the representation theory of vertex operator algebras. Some of the papers contain detailed introductory material that is helpful for graduate students and researchers looking for an introduction to these research directions. The papers also discuss exciting recent developments in the area of conformal field theories, tensor categories and their applications and will be extremely useful for researchers working in these areas.

  2. The ABC of protein kinase conformations.

    Science.gov (United States)

    Möbitz, Henrik

    2015-10-01

    Due to their involvement in human diseases, protein kinases are an important therapeutic target class. Conformation is a key concept for understanding how functional activity, inhibition and sequence are linked. We assemble and annotate the mammalian structural kinome from the Protein Data Bank on the basis of a universal residue nomenclature. We identify a torsion angle around the Gly of the DFG-motif whose sharp distribution profile corresponds to three eclipsed conformations. This allows the definition a small set of clusters whose distribution shows a bias for the active conformation. A common rationale links the active and inactive state: stabilization of the active conformation, as well as inactivation by displacement of helix-αC or the DFG-motif is governed by the interaction between helix-αC and the DFG motif. In particular, the conformation of the DFG-motif is tightly correlated with the propensity of helix-αC displacement. Our analysis reveals detailed mechanisms for the displacement of helix-αC and the DFG and improves our understanding of the role of individual residues. By pooling conformations from the whole structural kinome, the energetic contributions of sequence and extrinsic factors can be estimated in free energy analyses. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Analytical halo model of galactic conformity

    Science.gov (United States)

    Pahwa, Isha; Paranjape, Aseem

    2017-09-01

    We present a fully analytical halo model of colour-dependent clustering that incorporates the effects of galactic conformity in a halo occupation distribution framework. The model, based on our previous numerical work, describes conformity through a correlation between the colour of a galaxy and the concentration of its parent halo, leading to a correlation between central and satellite galaxy colours at fixed halo mass. The strength of the correlation is set by a tunable 'group quenching efficiency', and the model can separately describe group-level correlations between galaxy colour (1-halo conformity) and large-scale correlations induced by assembly bias (2-halo conformity). We validate our analytical results using clustering measurements in mock galaxy catalogues, finding that the model is accurate at the 10-20 per cent level for a wide range of luminosities and length-scales. We apply the formalism to interpret the colour-dependent clustering of galaxies in the Sloan Digital Sky Survey (SDSS). We find good overall agreement between the data and a model that has 1-halo conformity at a level consistent with previous results based on an SDSS group catalogue, although the clustering data require satellites to be redder than suggested by the group catalogue. Within our modelling uncertainties, however, we do not find strong evidence of 2-halo conformity driven by assembly bias in SDSS clustering.

  4. Controlling complex networks with conformity behavior

    Science.gov (United States)

    Wang, Xu-Wen; Nie, Sen; Wang, Wen-Xu; Wang, Bing-Hong

    2015-09-01

    Controlling complex networks accompanied by common conformity behavior is a fundamental problem in social and physical science. Conformity behavior that individuals tend to follow the majority in their neighborhood is common in human society and animal communities. Despite recent progress in understanding controllability of complex networks, the existent controllability theories cannot be directly applied to networks associated with conformity. Here we propose a simple model to incorporate conformity-based decision making into the evolution of a network system, which allows us to employ the exact controllability theory to explore the controllability of such systems. We offer rigorous theoretical results of controllability for representative regular networks. We also explore real networks in different fields and some typical model networks, finding some interesting results that are different from the predictions of structural and exact controllability theory in the absence of conformity. We finally present an example of steering a real social network to some target states to further validate our controllability theory and tools. Our work offers a more realistic understanding of network controllability with conformity behavior and can have potential applications in networked evolutionary games, opinion dynamics and many other complex networked systems.

  5. RADIATION ACOUSTICS

    OpenAIRE

    Lyamshev, L.

    1990-01-01

    Radiation acoustics is a new branch of acoustics. Its' fundamentals are lying in the research of acoustical effects due to the interaction of a radiation with matter. The sound excitation in liquids and solids by modulated or pulsed particle beams (electron, proton, ion beams, γ-radiation and single high-energy elementary particles) and some practical applications are discussed.

  6. A novel correction factor based on extended volume to complement the conformity index.

    Science.gov (United States)

    Jin, F; Wang, Y; Wu, Y-Z

    2012-08-01

    We propose a modified conformity index (MCI), based on extended volume, that improves on existing indices by correcting for the insensitivity of previous conformity indices to reference dose shape to assess the quality of high-precision radiation therapy and present an evaluation of its application. In this paper, the MCI is similar to the conformity index suggested by Paddick (CI(Paddick)), but with a different correction factor. It is shown for three cases: with an extended target volume, with an extended reference dose volume and without an extended volume. Extended volume is generated by expanding the original volume by 0.1-1.1 cm isotropically. Focusing on the simulation model, measurements of MCI employ a sphere target and three types of reference doses: a sphere, an ellipsoid and a cube. We can constrain the potential advantage of the new index by comparing MCI with CI(Paddick). The measurements of MCI in head-neck cancers treated with intensity-modulated radiation therapy and volumetric-modulated arc therapy provide a window on its clinical practice. The results of MCI for a simulation model and clinical practice are presented and the measurements are corrected for limited spatial resolution. The three types of MCI agree with each other, and comparisons between the MCI and CI(Paddick) are also provided. The results from our analysis show that the proposed MCI can provide more objective and accurate conformity measurement for high-precision radiation therapy. In combination with a dose-volume histogram, it will be a more useful conformity index.

  7. [Radiotherapy Techniques and Radiation Pneumonitis: A Lot To A Little Or A Little To A Lot?].

    Science.gov (United States)

    Yu, Bingqi; Wang, Jin; Xu, Yujin; Su, Feng; Shan, Guoping; Chen, Ming

    2015-12-01

    Radiotherapy is one of the main treatment for patients with lung cancer. Three-dimensional conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) are widely used to deliver radiation. Here, we focus on the correlations between dose distribution in lung and radiation pneumonitis according to the analysis about radiotherapy for lung cancer: A lot to a little or a little to a lot, which is the main cause of radiation pneumonitis?

  8. S-Adenosylmethionine conformations in solution and in protein complexes: Conformational influences of the sulfonium group

    DEFF Research Database (Denmark)

    Markham, George D.; Norrby, Per-Ola; Bock, Charles W.

    2002-01-01

    calculations. Nuclear Overhauser effect measurements and computational results for AdoMet indicate a predominantly anti conformation about the glycosidic bond with a variety of conformations about the methionyl C-alpha-C-beta and C-beta-C-gamma bonds. An AdoMet conformation in which the positively charged....... In 20 reported structures of AdoMet-protein complexes, both anti and syn glycosidic torsional angles are found. The methionyl group typically adopts an extended conformation in complexes with enzymes that transfer the methyl group from the sulfonium center, but is more folded in complexes with proteins...

  9. Radiation hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Pomraning, G.C.

    1982-12-31

    This course was intended to provide the participant with an introduction to the theory of radiative transfer, and an understanding of the coupling of radiative processes to the equations describing compressible flow. At moderate temperatures (thousands of degrees), the role of the radiation is primarily one of transporting energy by radiative processes. At higher temperatures (millions of degrees), the energy and momentum densities of the radiation field may become comparable to or even dominate the corresponding fluid quantities. In this case, the radiation field significantly affects the dynamics of the fluid, and it is the description of this regime which is generally the charter of radiation hydrodynamics. The course provided a discussion of the relevant physics and a derivation of the corresponding equations, as well as an examination of several simplified models. Practical applications include astrophysics and nuclear weapons effects phenomena.

  10. Comparative analysis of dose-volume histograms between 3D conformal and conventional non-conformal radiotherapy planning for prostate cancer; Analise comparativa dos histogramas de dose e volume entre planejamentos tridimensionais conformados e convencionais nao conformados na radioterapia do cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Feitosa, Silvia Moreira; Giordani, Adelmo Jose; Dias, Rodrigo Sousa; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil)], e-mail: silviamfeitosa@yahoo.com.br

    2009-03-15

    Objective: The present study was aimed at comparing conformal and non-conformal radiotherapy plans designed for patients with prostate cancer, by analyzing radiation doses in target volumes and organs at risk. Materials and methods: Radiotherapy plans for 40 patients with prostate cancer were analyzed. Conformal, conformal isocentric and non-conformal plans utilizing the source-surface distance were simulated for each of the patients for comparison of radiation dose in target volumes and organs at risk. For comparison purposes, dose-volume histograms for target volumes and organs at risk were analyzed. Results: Median doses were significantly lower in the conformal planning, with 25%, 40% and 60% volumes in the rectum and 30% and 60% in the bladder. The median doses were significantly lower in the conformal planning analyzing the right and left coxofemoral joints. Maximum, mean and median doses in the clinical target volume and in the planned target volume were significantly higher in the conformal planning. Conclusion: The present study has demonstrated that the conformal radiotherapy planning for prostate cancer allows the delivery of higher doses to the target volume and lower doses to adjacent healthy tissues. (author)

  11. Purification of recombinant growth hormone by clear native gels for conformational analyses: preservation of conformation and receptor binding.

    Science.gov (United States)

    Chen, Wei-Qiang; Salmazo, Anita; Myllykoski, Matti; Sjöblom, Björn; Bidlingmaier, Martin; Pollak, Arnold; Baumgärtel, Peter; Djinovic-Carugo, Kristina; Kursula, Petri; Lubec, Gert

    2010-08-01

    Most protein preparations require purification steps prior to biophysical analysis assessing protein stability, secondary structure and degree of folding. It was, therefore, the aim of this study to develop a system to separate and purify a protein from a commercially available medicinal product, recombinant human growth hormone (rhGH) and show preservation of conformation and function following the gel-based procedure. The rhGH was run on clear native (CN) gels and recovered from the gels by electroelution using D-Tube Dialyzer Midi under rigorous cooling. Melting point studies indicated preservation of the structural integrity. This finding was confirmed by synchrotron radiation circular dichroism spectroscopy (SRCD) revealing an identical folding pattern for the sample before and after electrophoretic separation and purification. Synchrotron small-angle X-ray scattering (SAXS) indicated that the sample was folded and monomeric, both before and after separation and purification, and that its shape corresponded well to the known crystal structure of GH. Binding properties of rhGH to a receptor-model system before and after clear native electrophoresis were comparable. This analytical and preparative approach to purify and concentrate a protein preserving conformation and function may be helpful for many applications in analytical, protein and stereochemistry.

  12. FlexyDos3D: a deformable anthropomorphic 3D radiation dosimeter: radiation properties

    DEFF Research Database (Denmark)

    De Deene, Yves; Skyt, Peter Sandegaard; Hill, Robin

    2015-01-01

    Three dimensional radiation dosimetry has received growing interest with the implementation of highly conformal radiotherapy treatments. The radiotherapy community faces new challenges with the commissioning of image guided and image gated radiotherapy treatments (IGRT) and deformable image...... and oxygen concentration has also been investigated. The radiophysical properties of this new dosimeter are discussed including stability, spatial integrity, temperature dependence of the dosimeter during radiation, readout and storage, dose rate dependence and tissue equivalence....

  13. Conformal optical elements for correcting wavefront distortions in YAG : Nd{sup 3+} active elements

    Energy Technology Data Exchange (ETDEWEB)

    Korolkov, V P; Nasyrov, R K; Poleshchuk, A G; Arapov, Yu D; Ivanov, A F

    2013-02-28

    Correction of the wavefront is studied for the light beam passing wide-aperture YAG : Nd3+ single-crystal rods, which are used as active elements in high-power solid-state lasers. A nonideal character of the crystal structure is responsible for the deformation of the wavefront of passing radiation. By using the halftone technology we have developed conformal aberration correctors capable of compensating rod nonuniformities and reducing the laser radiation divergence by an order of magnitude. The results obtained make it possible to employ optically nonuniform active elements in laser constructions. (laser optics 2012)

  14. Structures of W(2.2 Lie conformal algebra

    Directory of Open Access Journals (Sweden)

    Yuan Lamei

    2016-01-01

    . In this paper, we study conformal derivations, central extensions and conformal modules for this Lie conformal algebra. Also, we compute the cohomology of this Lie conformal algebra with coefficients in its modules. In particular, we determine its cohomology with trivial coefficients both for the basic and reduced complexes.

  15. Application of Conformational Space Search in Drug Action | Adikwu ...

    African Journals Online (AJOL)

    The role of conformational space in drug action is presented. Two examples of molecules in different therapeutic groups are presented. Conformational space search will lead to isolating the exact conformation with the desired medicinal properties. Many conformations of a plant isolate may exist which are active, weakly ...

  16. A note on fashion cycles, novelty and conformity

    OpenAIRE

    Alberti, Federica

    2013-01-01

    We develop a model in which novelty and conformity motivate fashion behavior. Fashion cycles occur if conformity is not too high. The duration of fashion cycles depends on individual-specific conformity, novelty, and the number of available styles. The use of individual-specific novelty and conformity allows us to also identify fashion leaders.

  17. 40 CFR 91.106 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 91.106... Provisions § 91.106 Certificate of conformity. (a) Every manufacturer of a new marine SI engine produced... obtain a certificate of conformity covering each engine family. The certificate of conformity must be...

  18. 47 CFR 68.320 - Supplier's Declaration of Conformity.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Supplier's Declaration of Conformity. 68.320... Approval § 68.320 Supplier's Declaration of Conformity. (a) Supplier's Declaration of Conformity is a... Supplier's Declaration of Conformity attaches to all items subsequently marketed by the responsible party...

  19. 47 CFR 2.906 - Declaration of Conformity.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Declaration of Conformity. 2.906 Section 2.906... Conformity. (a) A Declaration of Conformity is a procedure where the responsible party, as defined in § 2.909... of Conformity attaches to all items subsequently marketed by the responsible party which are...

  20. 21 CFR 26.70 - Conformity assessment bodies.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Conformity assessment bodies. 26.70 Section 26.70...Frameworkâ Provisions § 26.70 Conformity assessment bodies. Each party recognizes that the conformity... conformity in relation to its requirements as specified in subpart B of this part. The parties shall specify...

  1. Atoms, Radiation, and Radiation Protection

    CERN Document Server

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  2. Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

    Science.gov (United States)

    Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

    2017-08-01

    The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

  3. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  4. Conformal blocks and generalized Selberg integrals

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, A., E-mail: mironov@lpi.r [Lebedev Physics Institute (Russian Federation); ITEP, Moscow (Russian Federation); Morozov, Al., E-mail: morozov@itep.r [ITEP, Moscow (Russian Federation); Morozov, And., E-mail: andrey.morozov@itep.r [ITEP, Moscow (Russian Federation); Physics Department, Moscow State University, Moscow (Russian Federation)

    2011-02-11

    Operator product expansion (OPE) of two operators in two-dimensional conformal field theory includes a sum over Virasoro descendants of other operator with universal coefficients, dictated exclusively by properties of the Virasoro algebra and independent of choice of the particular conformal model. In the free field model, these coefficients arise only with a special 'conservation' relation imposed on the three dimensions of the operators involved in OPE. We demonstrate that the coefficients for the three unconstrained dimensions arise in the free field formalism when additional Dotsenko-Fateev integrals are inserted between the positions of the two original operators in the product. If such coefficients are combined to form an n-point conformal block on Riemann sphere, one reproduces the earlier conjectured {beta}-ensemble representation of conformal blocks. The statement can also be regarded as a relation between the 3j-symbols of the Virasoro algebra and the slightly generalized Selberg integrals I{sub Y}, associated with arbitrary Young diagrams. The conformal blocks are multilinear combinations of such integrals and the AGT conjecture relates them to the Nekrasov functions which have exactly the same structure.

  5. Evolution of Conformity in Social Dilemmas.

    Directory of Open Access Journals (Sweden)

    Yali Dong

    Full Text Available People often deviate from their individual Nash equilibrium strategy in game experiments based on the prisoner's dilemma (PD game and the public goods game (PGG, whereas conditional cooperation, or conformity, is supported by the data from these experiments. In a complicated environment with no obvious "dominant" strategy, conformists who choose the average strategy of the other players in their group could be able to avoid risk by guaranteeing their income will be close to the group average. In this paper, we study the repeated PD game and the repeated m-person PGG, where individuals' strategies are restricted to the set of conforming strategies. We define a conforming strategy by two parameters, initial action in the game and the influence of the other players' choices in the previous round. We are particularly interested in the tit-for-tat (TFT strategy, which is the well-known conforming strategy in theoretical and empirical studies. In both the PD game and the PGG, TFT can prevent the invasion of non-cooperative strategy if the expected number of rounds exceeds a critical value. The stability analysis of adaptive dynamics shows that conformity in general promotes the evolution of cooperation, and that a regime of cooperation can be established in an AllD population through TFT-like strategies. These results provide insight into the emergence of cooperation in social dilemma games.

  6. Conformal blocks and generalized Selberg integrals

    Science.gov (United States)

    Mironov, A.; Morozov, Al.; Morozov, And.

    2011-02-01

    Operator product expansion (OPE) of two operators in two-dimensional conformal field theory includes a sum over Virasoro descendants of other operator with universal coefficients, dictated exclusively by properties of the Virasoro algebra and independent of choice of the particular conformal model. In the free field model, these coefficients arise only with a special “conservation” relation imposed on the three dimensions of the operators involved in OPE. We demonstrate that the coefficients for the three unconstrained dimensions arise in the free field formalism when additional Dotsenko-Fateev integrals are inserted between the positions of the two original operators in the product. If such coefficients are combined to form an n-point conformal block on Riemann sphere, one reproduces the earlier conjectured β-ensemble representation of conformal blocks. The statement can also be regarded as a relation between the 3j-symbols of the Virasoro algebra and the slightly generalized Selberg integrals I, associated with arbitrary Young diagrams. The conformal blocks are multilinear combinations of such integrals and the AGT conjecture relates them to the Nekrasov functions which have exactly the same structure.

  7. Arcjet Testing of Advanced Conformal Ablative TPS

    Science.gov (United States)

    Gasch, Matthew; Beck, Robin; Agrawal, Parul

    2014-01-01

    A conformable TPS over a rigid aeroshell has the potential to solve a number of challenges faced by traditional rigid TPS materials (such as tiled Phenolic Impregnated Carbon Ablator (PICA) system on MSL. The compliant (high strain to failure) nature of the conformable ablative materials will allow integration of the TPS with the underlying aeroshell structure much easier and enable monolithic-like configuration and larger segments (or parts) to be used. In May of 2013 the CA250 project executed an arcjet test series in the Ames IHF facility to evaluate a phenolic-based conformal system (named Conformal-PICA) over a range of test conditions from 40-400Wcm2. The test series consisted of four runs in the 13-inch diameter nozzle. Test models were based on SPRITE configuration (a 55-deg sphere cone), as it was able to provide a combination of required heat flux, pressure and shear within a single entry. The preliminary in-depth TC data acquired during that test series allowed a mid-fidelity thermal response model for conformal-PICA to be created while testing of seam models began to address TPS attachment and joining of multiple segments for future fabrication of large-scale aeroshells. Discussed in this paper are the results.

  8. Evolution of Conformity in Social Dilemmas.

    Science.gov (United States)

    Dong, Yali; Li, Cong; Tao, Yi; Zhang, Boyu

    2015-01-01

    People often deviate from their individual Nash equilibrium strategy in game experiments based on the prisoner's dilemma (PD) game and the public goods game (PGG), whereas conditional cooperation, or conformity, is supported by the data from these experiments. In a complicated environment with no obvious "dominant" strategy, conformists who choose the average strategy of the other players in their group could be able to avoid risk by guaranteeing their income will be close to the group average. In this paper, we study the repeated PD game and the repeated m-person PGG, where individuals' strategies are restricted to the set of conforming strategies. We define a conforming strategy by two parameters, initial action in the game and the influence of the other players' choices in the previous round. We are particularly interested in the tit-for-tat (TFT) strategy, which is the well-known conforming strategy in theoretical and empirical studies. In both the PD game and the PGG, TFT can prevent the invasion of non-cooperative strategy if the expected number of rounds exceeds a critical value. The stability analysis of adaptive dynamics shows that conformity in general promotes the evolution of cooperation, and that a regime of cooperation can be established in an AllD population through TFT-like strategies. These results provide insight into the emergence of cooperation in social dilemma games.

  9. Is non-conformity WEIRD? Cultural variation in adults' beliefs about children's competency and conformity.

    Science.gov (United States)

    Clegg, Jennifer M; Wen, Nicole J; Legare, Cristine H

    2017-03-01

    Cross-cultural comparisons provide critical insight into variation in reasoning about intelligence. In two studies, the authors used a novel methodology based on multivocal ethnography to assess the role of conformity in U.S. and Ni-Vanuatu adults' judgments of children's intelligence and, as a comparison trait, good behavior. In Study 1, there were cultural differences in the impact of conformity on U.S. and Ni-Vanuatu adults' judgments of children's intelligence and good behavior. When evaluating U.S. children only, U.S. adults were less likely to endorse high conformity children as intelligent, often citing creativity as a justification for their judgments. In contrast, Ni-Vanuatu adults were more likely to endorse Ni-Vanuatu high conformity children as intelligent. Ni-Vanuatu adults were also more likely to endorse high conformity children as well-behaved than U.S. adults. In Study 2, there were no effects of socioeconomic status on U.S. adults' evaluations of conformity. U.S. adults were less likely to endorse high conformity children as intelligent than Ni-Vanuatu adults. Taken together, the data demonstrate that beliefs about the relations between intelligence, conformity, and creativity vary within and across cultures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. ConformRank: A conformity-based rank for finding top-k influential users

    Science.gov (United States)

    Wang, Qiyao; Jin, Yuehui; Cheng, Shiduan; Yang, Tan

    2017-05-01

    Finding influential users is a hot topic in social networks. For example, advertisers identify influential users to make a successful campaign. Retweeters forward messages from original users, who originally publish messages. This action is referred to as retweeting. Retweeting behaviors generate influence. Original users have influence on retweeters. Whether retweeters keep the same sentiment as original users is taken into consideration in this study. Influence is calculated based on conformity from emotional perspective after retweeting. A conformity-based algorithm, called ConformRank, is proposed to find top-k influential users, who make the most users keep the same sentiment after retweeting messages. Emotional conformity is introduced to denote how users conform to original users from the emotional perspective. Conforming weights are introduced to denote how two users keep the same sentiment after retweeting messages. Emotional conformity is applied for users and conforming weights are used for relations. Experiments were conducted on Sina Weibo. Experimental results show that users have larger influence when they publish positive messages.

  11. Spontaneous breaking of conformal invariance in theories of conformally coupled matter and Weyl gravity

    Energy Technology Data Exchange (ETDEWEB)

    Edery, A [Department of Physics, Bishop' s University, Lennoxville, QC J1M 1Z7 (Canada); Fabbri, Luca [Theory Group, INFN Section of Bologna, Department of physics, University of Bologna, Via Irnerio 46, C.A.P. 40126, Bologna (Italy); Paranjape, M B [Groupe de physique des particules, Universite de Montreal, C.P. 6128, succ. centre-ville, Montreal, QC H3C 3J7 (Canada)

    2006-11-21

    We study the theory of Weyl conformal gravity with matter degrees of freedom in a conformally invariant interaction. Specifically, we consider a triplet of scalar fields and SO(3) non-Abelian gauge fields, i.e. the Georgi-Glashow model conformally coupled to Weyl gravity. We show that the equations of motion admit solutions spontaneously breaking the conformal symmetry and the gauge symmetry, providing a mechanism for supplying a scale in the theory. The vacuum solution corresponds to anti-de Sitter spacetime, while localized soliton solutions correspond to magnetic monopoles in asymptotically anti-de Sitter spacetime. This mechanism strengthens the reasons for considering conformally invariant matter-gravity theory, which has shown promising indications concerning the problem of missing matter in galactic rotation curves.

  12. Radiation carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk.

  13. The conforming brain and deontological resolve.

    Directory of Open Access Journals (Sweden)

    Melanie Pincus

    Full Text Available Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules.

  14. A mass-independent conformal quantum cloak

    Science.gov (United States)

    Lin, De-Hone

    2017-11-01

    An obstacle to constructing a quantum cloak with the transformation design method for steering a matter wave is the device involving the anisotropic modulation of the particle mass. It is the purpose of this paper to show that a narrow-acceptance-angle quantum cloak generated by a kind of conformal mapping could be mass-independent. This greatly simplifies the construction of the device since it can now be finished only by applying a potential field to a region of the shell. As demonstrations of the conclusion, an elliptical and a parabolic conformal quantum cloak are designed from the elliptical and parabolic coordinate systems. Their performance is inspected by probability currents. It is shown that the conformal devices can serve as novel splitters for a 2D matter wave. Finally, we discuss the difficulty of constructing a steering device from the hyperbolic coordinate system.

  15. Understanding Modern Magnets through Conformal Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Halbach, K.

    1989-10-27

    When I had to choose, within some narrow range, the topic of this paper, I received great help from a colleague in Berkeley and from Prof. Little when it was suggested that I should pick among the possible subjects of my talk the subject that Prof. Bloch would have enjoyed most. Since Prof. Bloch would prefer a scalpel over a sword every time, I hope and think that most people will approve my choice. When one intends to talk about a subject that is as old as conformal mapping and one does not want to lose the audience in a very short time, it is advisable to start by explaining both the motivation for the talk as well as the goals one has in mind when giving the talk. This particular talk has been motivated by the increasing frequency with which one hears, from people that ought to know better, statements like: 'Conformal mapping is really a thing of the past because of all the marvelous computer programs that we now have'. Even though, or more likely because, I have been intimately involved in the development of some large and widely used computer codes, I am deeply disturbed by such statements since they indicate a severe lack of understanding of the purpose of conformal mapping techniques, computers, and computer codes. In my view, conformal mapping can be an extremely powerful computational technique, and the easy availability of computers has made that aspect even more important now than it has been in the past. Additionally, and more importantly, conformal mapping can give very deep and unique insight into problems, giving often solutions to problems that can not be obtained with any other method, in particular not with computers. Wanting to demonstrate in particular the latter part, I set myself two goals for this talk: (1) I want to show with the help of a number of examples that conformal mapping is a unique and enormously powerful tool for thinking about, and solving, problems. Usually one has to write down only a few equations, and sometimes

  16. Multi-field conformal cosmological attractors

    Science.gov (United States)

    Kallosh, Renata; Linde, Andrei

    2013-12-01

    We describe a broad class of multi-field inflationary models with spontaneously broken conformal invariance. It generalizes the recently discovered class of cosmological attractors with a single inflaton field [1]. In the new multi-field theories, just as in the single-field models of [1], the moduli space has a boundary (Kähler cone) in terms of the original homogeneous conformal variables. Upon spontaneous breaking of the conformal invariance and switching to the Einstein frame, this boundary moves to infinity in terms of the canonically normalized inflaton field. This results in the exponential stretching and flattening of scalar potentials in the vicinity of the boundary of the moduli space, which makes even very steep potentials perfectly suitable for the slow-roll inflation. These theories, just like their single-field versions, typically lead to inflationary perturbations with ns = 1-2/N and r = 12/N2, where N is the number of e-foldings.

  17. Black holes in massive conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    Myung, Yun Soo, E-mail: ysmyung@inje.ac.kr

    2014-03-07

    We analyze the classical stability of Schwarzschild black hole in massive conformal gravity which was recently proposed for another massive gravity model. This model in the Jordan frame is conformally equivalent to the Einstein–Weyl gravity in the Einstein frame. The coupled linearized Einstein equation is decomposed into the traceless and trace equation when one chooses 6m{sup 2}φ=δR. Solving the traceless equation exhibits unstable modes featuring the Gregory–Laflamme s-mode instability of five-dimensional black string, while we find no unstable modes when solving the trace equation. It is shown that the instability of the black hole in massive conformal gravity arises from the massiveness where the geometry of extra dimension trades for mass.

  18. Anisotropic stellar models admitting conformal motion

    Science.gov (United States)

    Banerjee, Ayan; Banerjee, Sumita; Hansraj, Sudan; Ovgun, Ali

    2017-04-01

    We address the problem of finding static and spherically symmetric anisotropic compact stars in general relativity that admit conformal motions. The study is framed in the language of f( R) gravity theory in order to expose opportunity for further study in the more general theory. Exact solutions of compact stars are found under the assumption that spherically symmetric spacetimes admit conformal motion with anisotropic matter distribution in nature. In this work, two cases have been studied for the existence of such solutions: first, we consider the model given by f(R)=R and then f(R)=aR+b . Finally, specific characteristics and physical properties have been explored analytically along with graphical representations for conformally symmetric compact stars in f( R) gravity.

  19. Causality Constraints in Conformal Field Theory

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Causality places nontrivial constraints on QFT in Lorentzian signature, for example fixing the signs of certain terms in the low energy Lagrangian. In d-dimensional conformal field theory, we show how such constraints are encoded in crossing symmetry of Euclidean correlators, and derive analogous constraints directly from the conformal bootstrap (analytically). The bootstrap setup is a Lorentzian four-point function corresponding to propagation through a shockwave. Crossing symmetry fixes the signs of certain log terms that appear in the conformal block expansion, which constrains the interactions of low-lying operators. As an application, we use the bootstrap to rederive the well known sign constraint on the (∂φ)4 coupling in effective field theory, from a dual CFT. We also find constraints on theories with higher spin conserved currents. Our analysis is restricted to scalar correlators, but we argue that similar methods should also impose nontrivial constraints on the interactions of spinni...

  20. Conformal transformation route to gravity's rainbow

    Science.gov (United States)

    He, Miao; Li, Ping; Wang, Zi-Liang; Ding, Jia-Cheng; Deng, Jian-Bo

    2018-02-01

    Conformal transformation as a mathematical tool has been used in many areas of gravitational physics. In this paper, we consider gravity's rainbow, in which the metric can be treated as a conformal rescaling of the original metric. By using the conformal transformation technique, we get a specific form of a modified Newton's constant and cosmological constant in gravity's rainbow, which implies that the total vacuum energy is dependent on probe energy. Moreover, the result shows that Einstein gravity's rainbow can be described by energy-dependent f(E,\\tilde{R}) gravity. At last, we study the f( R) gravity, when gravity's rainbow is considered, which can also be described as energy-dependent \\tilde{f}(E,\\tilde{R}) gravity.

  1. On conformal supergravity and harmonic superspace

    Energy Technology Data Exchange (ETDEWEB)

    Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands)

    2016-03-16

    This paper describes a fully covariant approach to harmonic superspace. It is based on the conformal superspace description of conformal supergravity and involves extending the supermanifold M{sup 4|8} by the tangent bundle of ℂP{sup 1}. The resulting superspace M{sup 4|8}×TℂP{sup 1} can be identified in a certain gauge with the conventional harmonic superspace M{sup 4|8}×S{sup 2}. This approach not only makes the connection to projective superspace transparent, but simplifies calculations in harmonic superspace significantly by eliminating the need to deal directly with supergravity prepotentials. As an application of the covariant approach, we derive from harmonic superspace the full component action for the sigma model of a hyperkähler cone coupled to conformal supergravity. Further applications are also sketched.

  2. Hawking radiation

    Science.gov (United States)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  3. GRAVITATIONAL RADIATION

    Directory of Open Access Journals (Sweden)

    Metin SALTIK

    1996-03-01

    Full Text Available According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated.

  4. Conformal interfaces between free boson orbifold theories

    Science.gov (United States)

    Becker, Melanie; Cabrera, Yaniel; Robbins, Daniel

    2017-09-01

    We construct a large class of conformal interfaces between two-dimensional c = 1 conformal field theories describing compact free bosons and their Z_2 orbifolds. The interfaces are obtained by constructing boundary states in the corresponding c = 2 product theories and applying the unfolding procedure. We compute the fusion products for all of these defects, and identify the invertible topological interfaces associated to global symmetries, the interfaces corresponding to marginal deformations, and the interfaces which map the untwisted sector of an orbifold to the invariant states of the parent theory.

  5. Conformity to peer pressure in preschool children

    OpenAIRE

    Haun, D.; Tomasello, M

    2011-01-01

    Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2 and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously erroneous but unanimous public judgments right before them. A follow-up study with 18 groups of 4 children between 4;0 and 4;6 years of age revealed that children did not chang...

  6. Spherical conformal models for compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Takisa, P.M.; Maharaj, S.D.; Manjonjo, A.M.; Moopanar, S. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)

    2017-10-15

    We consider spherical exact models for compact stars with anisotropic pressures and a conformal symmetry. The conformal symmetry condition generates an integral relationship between the gravitational potentials. We solve this condition to find a new anisotropic solution to the Einstein field equations. We demonstrate that the exact solution produces a relativistic model of a compact star. The model generates stellar radii and masses consistent with PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. A detailed physical examination shows that the model is regular, well behaved and stable. The mass-radius limit and the surface red shift are consistent with observational constraints. (orig.)

  7. Geometry and conformations of benzenecarboxylic acids

    Directory of Open Access Journals (Sweden)

    IVAN GUTMAN

    2004-11-01

    Full Text Available The geometry, conformations and energy of mono-, di-, and tri-carboxylic derivatives of benzene were studied by means of the AM1 molecular-orbital method. Whereas the species having no carboxylic groups in the ortho-position (benzoic, isophthalic, terephthalic, and trimesic acids are planar in all their (stable conformations, those possessing carboxylic groups in the ortho-position (phthalic, 1,2,3-benzenetricarboxylic, and 1,2,4-benzenetricarboxylic acids assume a non-planar geometry, with one carboxyl group almost orthogonal to the plane of the benzene ring. Various rotamers of each of the studied benzenecarboxylic acids have nearly the same energy.

  8. Singularities, horizons, firewalls, and local conformal symmetry

    CERN Document Server

    Hooft, Gerard 't

    2015-01-01

    The Einstein-Hilbert theory of gravity can be rephrased by focusing on local conformal symmetry as an exact, but spontaneously broken symmetry of nature. The conformal component of the metric field is then treated as a dilaton field with only renormalizable interactions. This imposes constraints on the theory, which can also be viewed as demanding regularity of the action as the dilaton field variable tends to 0. In other words, we have constraints on the small distance behaviour. Our procedure appears to turn a black hole into a regular, topologically trivial soliton without singularities, horizons of firewalls, but many questions remain.

  9. Game Theory and Social Psychology: Conformity Games

    Science.gov (United States)

    Alessio, Danielle; Kilgour, D. Marc

    2011-11-01

    Game models can contribute to understanding of how social biases and pressures to conform can lead to puzzling behaviour in social groups. A model of the psychological biases false uniqueness and false consensus is set out. The model predicts the phenomenon of pluralistic ignorance, which is well-studied in social psychology, showing how it arises as a result of the prevalence of false uniqueness and the desire to conform. An efficient method is developed for finding Nash equilibria of the model under certain restrictions.

  10. Correct light deflection in Weyl conformal gravity

    Science.gov (United States)

    Cattani, Carlo; Scalia, Massimo; Laserra, Ettore; Bochicchio, Ivana; Nandi, Kamal K.

    2013-02-01

    The conformal gravity fit to observed galactic rotation curves requires γ>0. On the other hand, the conventional method for light deflection by galaxies gives a negative contribution to the Schwarzschild value for γ>0, which is contrary to observation. Thus, it is very important that the contribution to bending should in principle be positive, no matter how small its magnitude is. Here we show that the Rindler-Ishak method gives a positive contribution to Schwarzschild deflection for γ>0, as desired. We also obtain the exact local coupling term derived earlier by Sereno. These results indicate that conformal gravity can potentially test well against all astrophysical observations to date.

  11. Conformal invariants topics in geometric function theory

    CERN Document Server

    Ahlfors, Lars V

    2010-01-01

    Most conformal invariants can be described in terms of extremal properties. Conformal invariants and extremal problems are therefore intimately linked and form together the central theme of this classic book which is primarily intended for students with approximately a year's background in complex variable theory. The book emphasizes the geometric approach as well as classical and semi-classical results which Lars Ahlfors felt every student of complex analysis should know before embarking on independent research. At the time of the book's original appearance, much of this material had never ap

  12. Conformal metamaterial absorber for curved surface.

    Science.gov (United States)

    Jang, Youngsoo; Yoo, Minyeong; Lim, Sungjoon

    2013-10-07

    In this paper, three different unit cells are designed on the basis split-ring-cross resonators, and each unit cell has an absorption rate greater than 90% at incident angles of 0°, 30°, and 45°, respectively. They are non-periodically placed in three different zones on the curved surface. Therefore, the proposed conformal metamaterial absorber can achieve a high absorption rate. The performance of the proposed absorber is compared with that of a metallic curved surface and a conformal metamaterial absorber with the same unit cells.

  13. Raising a gender non-conforming child.

    Science.gov (United States)

    Wisnowski, Deborah L

    2011-10-01

    This article overviews the challenges parents face raising gender non-conforming children. The author is the mother of a fifteen year old gender non-conforming (GNC) child and co-founder of Stepping Stones Support Group which organizes support programs for families of GNC. The article discusses social challenges, educational challenges and internal conflicts the author has experienced while raising her child. The author also discusses the process of founding Stepping Stones and the importance having support has played in her and her child's life.

  14. Wilson loop invariants from WN conformal blocks

    Directory of Open Access Journals (Sweden)

    Oleg Alekseev

    2015-12-01

    Full Text Available Knot and link polynomials are topological invariants calculated from the expectation value of loop operators in topological field theories. In 3D Chern–Simons theory, these invariants can be found from crossing and braiding matrices of four-point conformal blocks of the boundary 2D CFT. We calculate crossing and braiding matrices for WN conformal blocks with one component in the fundamental representation and another component in a rectangular representation of SU(N, which can be used to obtain HOMFLY knot and link invariants for these cases. We also discuss how our approach can be generalized to invariants in higher-representations of WN algebra.

  15. Modern Radiation Therapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim; Illidge, Tim

    2014-01-01

    Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced...... on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy......, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom...

  16. Radiation Protection

    Energy Technology Data Exchange (ETDEWEB)

    Loos, M

    2002-04-01

    Major achievements of SCK-CEN's Radiation Protection Department in 2001 are described. The main areas for R and D of the department are enviromnental remediation, emergency planning, radiation protection research, low-level radioactvity measurements, safeguards and physics measurements, decision strategy research and policy support and social sciences in nuclear research. Main achievements for 2001 in these areas are reported.

  17. Holographic applications of logarithmic conformal field theories

    NARCIS (Netherlands)

    Grumiller, D.; Riedler, W.; Rosseel, J.; Zojer, T.

    2013-01-01

    We review the relations between Jordan cells in various branches of physics, ranging from quantum mechanics to massive gravity theories. Our main focus is on holographic correspondences between critically tuned gravity theories in anti-de Sitter space and logarithmic conformal field theories in

  18. A Formal Approach to Conformance Testing

    NARCIS (Netherlands)

    Tretmans, G.J.

    1992-01-01

    In order to assure successful communication between computer systems from different manufacturers, standardized communication protocols are being developed and specified. As a next step implementations of these protocols are needed that conform to these specifications. Testing is a way to check

  19. NMR studies of dynamic biomolecular conformational ensembles.

    Science.gov (United States)

    Torchia, Dennis A

    2015-02-01

    Multidimensional heteronuclear NMR approaches can provide nearly complete sequential signal assignments of isotopically enriched biomolecules. The availability of assignments together with measurements of spin relaxation rates, residual spin interactions, J-couplings and chemical shifts provides information at atomic resolution about internal dynamics on timescales ranging from ps to ms, both in solution and in the solid state. However, due to the complexity of biomolecules, it is not possible to extract a unique atomic-resolution description of biomolecular motions even from extensive NMR data when many conformations are sampled on multiple timescales. For this reason, powerful computational approaches are increasingly applied to large NMR data sets to elucidate conformational ensembles sampled by biomolecules. In the past decade, considerable attention has been directed at an important class of biomolecules that function by binding to a wide variety of target molecules. Questions of current interest are: "Does the free biomolecule sample a conformational ensemble that encompasses the conformations found when it binds to various targets; and if so, on what time scale is the ensemble sampled?" This article reviews recent efforts to answer these questions, with a focus on comparing ensembles obtained for the same biomolecules by different investigators. A detailed comparison of results obtained is provided for three biomolecules: ubiquitin, calmodulin and the HIV-1 trans-activation response RNA. Published by Elsevier B.V.

  20. Chaotropes trigger conformational rearrangements differently in ...

    Indian Academy of Sciences (India)

    However, the mechanism of denaturation varied with the studied conditions, like different SDS concentrations and hydronium ion potentials, wherein the proteinundergoes a conformational rearrangement from β-sheet to α-helix. Moreover, GdnHCl triggered complete denaturation of ConA into a predominantly random coil ...

  1. Black Hole Monodromy and Conformal Field Theory

    NARCIS (Netherlands)

    Castro, A.; Lapan, J.M.; Maloney, A.; Rodriguez, M.J.

    2013-01-01

    The analytic structure of solutions to the Klein-Gordon equation in a black hole background, as represented by monodromy data, is intimately related to black hole thermodynamics. It encodes the "hidden conformal symmetry" of a nonextremal black hole, and it explains why features of the inner event

  2. Attraction and Repulsion in Conformal Gravity

    CERN Document Server

    Phillips, Peter R

    2015-01-01

    We use numerical integration to solve the field equations of conformal gravity, assuming a metric that is static and spherically symmetric. Our solution is an extension of that found by Mannheim and Kazanas; it indicates, as expected, that gravitation in this model should be attractive on small scales and repulsive on large ones.

  3. Do Charge State Signatures Guarantee Protein Conformations?

    Science.gov (United States)

    Hall, Zoe; Robinson, Carol V.

    2012-07-01

    The extent to which proteins in the gas phase retain their condensed-phase structure is a hotly debated issue. Closely related to this is the degree to which the observed charge state reflects protein conformation. Evidence from electron capture dissociation, hydrogen/deuterium exchange, ion mobility, and molecular dynamics shows clearly that there is often a strong correlation between the degree of folding and charge state, with the most compact conformations observed for the lowest charge states. In this article, we address recent controversies surrounding the relationship between charge states and folding, focussing also on the manipulation of charge in solution and its effect on conformation. `Supercharging' reagents that have been used to effect change in charge state can promote unfolding in the electrospray droplet. However for several protein complexes, supercharging does not appear to perturb the structure in that unfolding is not detected. Consequently, a higher charge state does not necessarily imply unfolding. Whilst the effect of charge manipulation on conformation remains controversial, there is strong evidence that a folded, compact state of a protein can survive in the gas phase, at least on a millisecond timescale. The exact nature of the side-chain packing and secondary structural elements in these compact states, however, remains elusive and prompts further research.

  4. Conformable Pressurized Structures : Design and Analysis

    NARCIS (Netherlands)

    Geuskens, F.J.J.M.M.

    2012-01-01

    There are many applications where volume needs to be pressurised within a geometrical space for which conventional pressure vessels do not provide suitable solutions. Applications are for example found in pressure cabins for Blended Wing Body Aircraft and conformable pressure vessels for an

  5. Hydrocarbon chain conformation in an intercalated surfactant ...

    Indian Academy of Sciences (India)

    trans conformation with most of the trans chain aligned parallel to the gallery walls. On lowering the temperature, molecular plane aligns parallel, so that the methylene chain lies flat, rigid and aligned to the confining surface. In the bilayer phase ...

  6. Polymer conformation during flow in porous media

    NARCIS (Netherlands)

    Kawale, D.; Bouwman, G.W.; Sachdev, S.; Zitha, P.L.J.; Kreutzer, M.T.; Rossen, W.R.; Boukany, P.

    2017-01-01

    Molecular conformations of individual polymers during flow through porous media are directly observed by single-DNA imaging in microfluidics. As the Weissenberg number increases during flow (Wi > 1), we observe two types of elastic instabilities: (a) stationary dead-zone and (b) time-dependant

  7. Entanglement Entropy in Warped Conformal Field Theories

    NARCIS (Netherlands)

    Castro, A.; Hofman, D.M.; Iqbal, N.

    We present a detailed discussion of entanglement entropy in (1+1)-dimensional Warped Conformal Field Theories (WCFTs). We implement the Rindler method to evaluate entanglement and Renyi entropies for a single interval and along the way we interpret our results in terms of twist field correlation

  8. Surveillance and Conformity in Competitive Youth Swimming

    Science.gov (United States)

    Lang, Melanie

    2010-01-01

    Underpinned by a Foucauldian analysis of sporting practices, this paper identifies the disciplinary mechanism of surveillance at work in competitive youth swimming. It highlights the ways in which swimmers and their coaches are subject to and apply this mechanism to produce embodied conformity to normative behaviour and obedient, docile bodies.…

  9. Conformational regulation of urokinase receptor function

    DEFF Research Database (Denmark)

    Gårdsvoll, Henrik; Jacobsen, Benedikte; Kriegbaum, Mette C

    2011-01-01

    PA per se into the hydrophobic ligand binding cavity of uPAR that modulates the function of this receptor. Based on these data, we now propose a model in which the inherent interdomain mobility in uPAR plays a major role in modulating its function. Particularly one uPAR conformation, which is stabilized...

  10. Conformity of Goods in International Sales

    DEFF Research Database (Denmark)

    Henschel, Rene Franz

    The Conformity of Goods in International Sales gives a systematic analysis of Article 35 in the United Nations Convention on Contracts for the International Sale of Goods (CISG). Based on a detailed analysis of the most important cases and leading academic writing, Article 35 is described...

  11. Food Place Profiling and the Conformity Paradox

    DEFF Research Database (Denmark)

    Therkelsen, Anette; Gyimóthy, Szilvia

    Drawing on earlier research on local food, terroir, authenticity, food narratives and conformity in branding efforts, we study the place branding strategies of four Danish coastal destinations, each focusing on profiling themselves as food places for tourists. Based on analyses of online food...

  12. Synthesis and conformational features of sym , ', ...

    Indian Academy of Sciences (India)

    A one pot reaction involving sym ,'-diarylthiourea and the respective arylamine in the presence of aq. KOH in nitrobenzene at ≥ 105°C afforded sym ,',"-triarylguanidine in fair to good yield and the products have been characterized. Sym ,',"-tri(4-tolyl)guanidine possesses (7) anti-anti conformation, sym ,' ...

  13. Conformation of hindered piperidines: Spectroscopic evidence for ...

    Indian Academy of Sciences (India)

    At room temperature the (3)-benzyl-(2),(6)-bis(aryl)piperidin-4-ones 1-4 exist in only one isomeric form whereas their -nitroso derivatives 5-8 exist in two isomeric forms. The preferred conformations of both the isomeric forms of nitrosamines were determined by comparison of the spectral data with those of the ...

  14. Testing of Advanced Conformal Ablative TPS

    Science.gov (United States)

    Gasch, Matthew; Agrawal, Parul; Beck, Robin

    2013-01-01

    In support of the CA250 project, this paper details the results of a test campaign that was conducted at the Ames Arcjet Facility, wherein several novel low density thermal protection (TPS) materials were evaluated in an entry like environment. The motivation for these tests was to investigate whether novel conformal ablative TPS materials can perform under high heat flux and shear environment as a viable alternative to rigid ablators like PICA or Avcoat for missions like MSL and beyond. A conformable TPS over a rigid aeroshell has the potential to solve a number of challenges faced by traditional rigid TPS materials (such as tiled Phenolic Impregnated Carbon Ablator (PICA) system on MSL, and honeycomb-based Avcoat on the Orion Multi Purpose Crew Vehicle (MPCV)). The compliant (high strain to failure) nature of the conformable ablative materials will allow better integration of the TPS with the underlying aeroshell structure and enable monolithic-like configuration and larger segments to be used in fabrication.A novel SPRITE1 architecture, developed by the researchers at NASA Ames was used for arcjet testing. This small probe like configuration with 450 spherecone, enabled us to test the materials in a combination of high heat flux, pressure and shear environment. The heat flux near the nose were in the range of 500-1000 W/sq cm whereas in the flank section of the test article the magnitudes were about 50 of the nose, 250-500W/sq cm range. There were two candidate conformable materials under consideration for this test series. Both test materials are low density (0.28 g/cu cm) similar to Phenolic Impregnated Carbon Ablator (PICA) or Silicone Impregnated Refractory Ceramic Ablator (SIRCA) and are comprised of: A flexible carbon substrate (Carbon felt) infiltrated with an ablative resin system: phenolic (Conformal-PICA) or silicone (Conformal-SICA). The test demonstrated a successful performance of both the conformable ablators for heat flux conditions between 50

  15. Small fields: nonequilibrium radiation dosimetry.

    Science.gov (United States)

    Das, Indra J; Ding, George X; Ahnesjö, Anders

    2008-01-01

    Advances in radiation treatment with beamlet-based intensity modulation, image-guided radiation therapy, and stereotactic radiosurgery (including specialized equipments like CyberKnife, Gamma Knife, tomotherapy, and high-resolution multileaf collimating systems) have resulted in the use of reduced treatment fields to a subcentimeter scale. Compared to the traditional radiotherapy with fields > or =4 x 4 cm2, this can result in significant uncertainty in the accuracy of clinical dosimetry. The dosimetry of small fields is challenging due to nonequilibrium conditions created as a consequence of the secondary electron track lengths and the source size projected through the collimating system that are comparable to the treatment field size. It is further complicated by the prolonged electron tracks in the presence of low-density inhomogeneities. Also, radiation detectors introduced into such fields usually perturb the level of disequilibrium. Hence, the dosimetric accuracy previously achieved for standard radiotherapy applications is at risk for both absolute and relative dose determination. This article summarizes the present knowledge and gives an insight into the future procedures to handle the nonequilibrium radiation dosimetry problems. It is anticipated that new miniature detectors with controlled perturbations and corrections will be available to meet the demand for accurate measurements. It is also expected that the Monte Carlo techniques will increasingly be used in assessing the accuracy, verification, and calculation of dose, and will aid perturbation calculations of detectors used in small and highly conformal radiation beams. rican Association of Physicists in Medicine.

  16. Advances in radiation therapy dosimetry

    Directory of Open Access Journals (Sweden)

    Paliwal Bhudatt

    2009-01-01

    Full Text Available During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D conformal radiation therapy to intensity-modulated radiation therapy (IMRT treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed.

  17. Radiation shield

    Energy Technology Data Exchange (ETDEWEB)

    Nemezawa, Isao; Kimura, Tadahiro [Hitachi Ltd., Tokyo (Japan); Omori, Tetsu; Mizuochi, Akira

    1997-11-18

    A radiation shield is constituted by using a flexible bag made of a synthetic resin, a rubber plate or a composite member of them. Water is charged therein as a shielding liquid. Water injection ports are formed at the lower surface, and gas exhaustion ports are formed on the upper surface of the radiation shield. A plurality of vertical ribs made of the same material as the bag of the radiation shield are formed, integral with the bag, each at a space on the outer surface of the radiation shield. A reinforcing tube are inserted to the vertical ribs integral with the bag. The reinforcing tube may be made of an metal or non-metal material, but material having a bending strength greater than that of the bag is used. When wide surfaces are constituted in the horizontal direction as radiation shielding surfaces, a plurality of the radiation shields are used being in adjacent in the horizontal direction. The reinforcing tubes in adjacent with each other among the adjacent radiation shields are connected by connectors. (I.N.)

  18. Radiation Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  19. Single-Molecule FRET States, Conformational Interchange, and Conformational Selection by Dye Labels in Calmodulin.

    Science.gov (United States)

    DeVore, Matthew S; Braimah, Adebayo; Benson, David R; Johnson, Carey K

    2016-05-19

    We investigate the roles of measurement time scale and the nature of the fluorophores in the FRET states measured for calmodulin, a calcium signaling protein known to undergo pronounced conformational changes. The measured FRET distributions depend markedly on the measurement time scale (nanosecond or microsecond). Comparison of FRET distributions measured by donor fluorescence decay with FRET distributions recovered from single-molecule burst measurements binned over time scales of 90 μs to 1 ms reveals conformational averaging over the intervening time regimes. We find further that, particularly in the presence of saturating Ca(2+), the nature of the measured single-molecule FRET distribution depends markedly on the identity of the FRET pair. The results suggest interchange between conformational states on time scales of hundreds of microseconds or less. Interaction with a fluorophore such as the dye Texas Red alters both the nature of the measured FRET distributions and the dynamics of conformational interchange. The results further suggest that the fluorophore may not be merely a benign reporter of protein conformations in FRET studies, but may in fact alter the conformational landscape.

  20. Modifying the planning target volume to optimize the dose distribution in dynamic conformal arc therapy for large metastatic brain tumors.

    Science.gov (United States)

    Ogura, Kengo; Kosaka, Yasuhiro; Imagumbai, Toshiyuki; Ueki, Kazuhito; Narukami, Ryo; Hattori, Takayuki; Kokubo, Masaki

    2017-06-01

    When treating large metastatic brain tumors with stereotactic radiotherapy (SRT), high dose conformity to target is difficult to achieve. Employing a modified planning target volume (mPTV) instead of the original PTV may be one way to improve the dose distribution in linear accelerator-based SRT using a dynamic conformal technique. In this study, we quantitatively analyzed the impact of a mPTV on dose distribution. Twenty-four tumors with a maximum diameter of >2 cm were collected. For each tumor, two plans were created: one used a mPTV and the other did not. The mPTV was produced by shrinking or enlarging the original PTV according to the dose distribution in the original plan. The dose conformity was evaluated and compared between the plans using a two-sided paired t test. The conformity index defined by the Radiation Therapy Oncology Group was 1.34 ± 0.10 and 1.41 ± 0.13, and Paddick's conformity index was 0.75 ± 0.05 and 0.71 ± 0.06, for the plans with and without a mPTV, respectively. All of these improvements were statistically significant (P < 0.05). The use of a mPTV can improve target conformity when planning SRT for large metastatic brain tumors.

  1. Conformity Index and Homogeneity Index of the Postoperative Whole Breast Radiotherapy.

    Science.gov (United States)

    Petrova, Deva; Smickovska, Snezana; Lazarevska, Emilija

    2017-10-15

    The treatment of breast cancer involves a multidisciplinary approach in which radiotherapy plays a key role. The conformity index and the homogeneity index are two analysis tools of a treatment plan using conformal radiotherapy. The purpose of this article is an analysis of these two parameters in the assessment of the treatment plans in 58 patients undergoing postoperative radiotherapy of the whole breast. All 58 patients participating in the study had a conservatively treated early-stage breast cancer. The treatment was performed using a standard regimen of fractionation in 25 fractions up to a total dose of 50 Gy. Dose-volume histograms were generated for both plans with and without segmental fields. Pair samples t-test was used. The technique with segmental fields allowed us more homogeneity distribution when compared to standard two tangential field techniques. The HI values were 1.08 ± 0.01 and 1.09 ± 0.01 for segment and technique with two tangential fields (p conformity and the homogeneity index are important tools in the analysis of the treatment plans during radiation therapy in patients with early-stage breast cancer. Adding segment fields in the administration of radiotherapy in patients with conservatively treated breast cancer can lead to improved dosage homogeneity and conformity.

  2. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  3. Boundary conformal anomalies on hyperbolic spaces and Euclidean balls

    Science.gov (United States)

    Rodriguez-Gomez, Diego; Russo, Jorge G.

    2017-12-01

    We compute conformal anomalies for conformal field theories with free conformal scalars and massless spin 1/2 fields in hyperbolic space ℍ d and in the ball B^d , for 2≤d≤7. These spaces are related by a conformal transformation. In even dimensional spaces, the conformal anomalies on ℍ2 n and B^{2n} are shown to be identical. In odd dimensional spaces, the conformal anomaly on B^{2n+1} comes from a boundary contribution, which exactly coincides with that of ℍ2 n + 1 provided one identifies the UV short-distance cutoff on B^{2n+1} with the inverse large distance IR cutoff on ℍ2 n + 1, just as prescribed by the conformal map. As an application, we determine, for the first time, the conformal anomaly coefficients multiplying the Euler characteristic of the boundary for scalars and half-spin fields with various boundary conditions in d = 5 and d = 7.

  4. Gauge Natural Formulation of Conformal Theory of Gravity

    CERN Document Server

    Campigotto, M

    2014-01-01

    We consider conformal gravity as a gauge natural theory. We study its conservation laws and superpotentials. We also consider the Mannheim and Kazanas spherically symmetric vacuum solution and discuss conserved quantities associated to conformal and diffeomorphism symmetries.

  5. Structural selection by microsolvation: Conformational locking of tryptamine

    NARCIS (Netherlands)

    Schmitt, M.; Bohm, M.; Ratzer, C.; Vu, C.; Kalkman, L.; Meerts, W.L.

    2005-01-01

    The conformational space of tryptamine has been thoroughly investigated using rotationally resolved laser-induced fluorescence spectroscopy. Six conformers could be identified on the basis of the inertial parameters of several deuterated isotopomers. Upon attaching a single water molecule, the

  6. Conformal Killing Vectors Of Plane Symmetric Four Dimensional Lorentzian Manifolds

    CERN Document Server

    Khan, Suhail; Bokhari, Ashfaque H; Khan, Gulzar Ali; Mathematics, Department of; Peshawar, University of; Pakhtoonkhwa, Peshawar Khyber; Pakistan.,; Petroleum, King Fahd University of; Minerals,; 31261, Dhahran; Arabia, Saudi

    2015-01-01

    In this paper, we investigate conformal Killing's vectors (CKVs) admitted by some plane symmetric spacetimes. Ten conformal Killing's equations and their general forms of CKVs are derived along with their conformal factor. The existence of conformal Killing's symmetry imposes restrictions on the metric functions. The conditions imposing restrictions on these metric functions are obtained as a set of integrability conditions. Considering the cases of time-like and inheriting CKVs, we obtain spacetimes admitting plane conformal symmetry. Integrability conditions are solved completely for some known non-conformally flat and conformally flat classes of plane symmetric spacetimes. A special vacuum plane symmetric spacetime is obtained, and it is shown that for such a metric CKVs are just the homothetic vectors (HVs). Among all the examples considered, there exists only one case with a six dimensional algebra of special CKVs admitting one proper CKV. In all other examples of non-conformally flat metrics, no proper ...

  7. Bcl-2 Conformational Change as an Indicator of Chemotherapy Response

    National Research Council Canada - National Science Library

    Zhang, Xiao-kung

    2005-01-01

    .... We propose that Bcl-2 undergoes a conformational change in response to chemotherapeutic agents in breast cancer cells in vitro and in vivo and that a Bcl-2-conformation-sensitive antibody can be used...

  8. Peer influence: Neural mechanisms underlying in-group conformity

    National Research Council Canada - National Science Library

    Stallen, Mirre; Smidts, Ale; Sanfey, Alan

    2013-01-01

    .... However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI...

  9. Conformity of nurse prescribing to care needs: nurses' understanding

    National Research Council Canada - National Science Library

    Marília Silveira Faeda; Márcia Galan Perroca

    2017-01-01

    Submission: 04-07-2016 Approval: 11-02-2016 ABSTRACT Objective: investigate the understanding of nurses on nurse prescribing conformity to the care needs of hospitalized patients and factors associated with that conformity. Method...

  10. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  11. Radiation Protection

    Energy Technology Data Exchange (ETDEWEB)

    Loos, M

    2001-04-01

    Major achievements of SCK-CEN's Radiation Protection Department in 2000 are described. The main areas for R and D of the department remain neutron dosimetry and neutron activation analysis, safeguards information handling and non-destructive assay techniques. Further activities include low-level radioactivity measurements in environmental and biological samples and radiation protection research. Finally, achievements in decision strategy research and social sciences in nuclear research are reported.

  12. Conformational changes of fibrinogen after adsorption.

    Science.gov (United States)

    Clarke, Matthew L; Wang, Jie; Chen, Zhan

    2005-11-24

    The adsorption behavior of fibrinogen to two biomedical polyurethanes and a perfluorinated polymer has been investigated. Changes in the secondary structure of adsorbed fibrinogen were monitored using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and sum frequency generation vibrational spectroscopy (SFG). SFG measurements were performed in the amide I range as well as in the C-H/N-H stretching range. Amide I signals from SFG demonstrate that fibrinogen has post-adsorption conformational changes that are dependent upon the polymer surface properties. For example, strong attenuation of the amide I and N-H stretching signals with increasing residence time was observed for fibrinogen adsorbed to poly(ether urethane) but not for the other two polymers. This change is not readily observed by ATR-FTIR. Differences in the observed spectral changes for fibrinogen adsorbed to each polymer are explained by different initial binding mechanisms and post-adsorption conformational changes.

  13. Spinor product computations for protein conformations.

    Science.gov (United States)

    Chys, Pieter; Chacón, Pablo

    2012-08-05

    Spinor operators in geometric algebra (GA) can efficiently describe conformational changes of proteins by ordered products that act on individual bonds and represent their net rotations. Backward propagation through the protein backbone yields all rotational spinor axes in advance allowing the efficient computation of atomic coordinates from internal coordinates. The introduced mathematical framework enables to efficiently manipulate and generate protein conformations to any arbitrary degree. Moreover, several new formulations in the context of rigid body motions are added. Emphasis is placed on the intimate relationship between spinors and quaternions, which can be recovered from within the GA approach. The spinor methodology is implemented and tested versus the state of the art algorithms for both protein construction and coordinate updating. Spinor calculations have a smaller computational cost and turn out to be slightly faster than current alternatives. Copyright © 2012 Wiley Periodicals, Inc.

  14. Problems with Mannheim's conformal gravity program

    Science.gov (United States)

    Yoon, Youngsub

    2013-07-01

    We show that Mannheim’s conformal gravity program, whose potential has a term proportional to 1/r and another term proportional to r, does not reduce to Newtonian gravity at short distances, unless one assumes undesirable singularities of the mass density of the proton. Therefore, despite the claim that it successfully explains galaxy rotation curves, unless one assumes the singularities, it seems to be falsified by numerous Cavendish-type experiments performed at laboratories on Earth whose work have not found any deviations from Newton’s theory. Moreover, it can be shown that as long as the total mass of the proton is positive, Mannheim’s conformal gravity program leads to negative linear potential, which is problematic from the point of view of fitting galaxy rotation curves, which necessarily requires positive linear potential.

  15. The conformational musings of a medicinal chemist.

    Science.gov (United States)

    Finch, Harry

    2014-03-01

    Structure-based drug design strategies based on X-ray crystallographic data of ligands bound to biological targets or computationally derived pharmacophore models have been introduced over the past 25 years or so. These have now matured and are deeply embedded in the drug discovery process in most pharmaceutical and biotechnology companies where they continue to play a major part in the discovery of new medicines and drug candidates. Newly developed NMR methods can now provide a full description of the conformations in which ligands exist in free solution, crucially allowing those that are dominant to be identified. Integrating experimentally determined conformational information on active and inactive molecules in drug discovery programmes, alongside the existing techniques, should have a major impact on the success of drug discovery. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Conformational biosensor for diagnosis of prion diseases.

    Science.gov (United States)

    Tcherkasskaya, Olga; Davidson, Eugene A; Schmerr, Mary Jo; Orser, Cindy S

    2005-05-01

    A fluorescence technology to monitor the proliferation of amyloidogenic neurological disorders is proposed. A crude brain homogenate (0.01%) from animals infected with a transmissible spongiform encephalopathy is employed as a catalytic medium initiating conformational changes in 520 nM polypeptide biosensors (Tris/trifluoroethanol 50% mixture at pH 7). The fluorescence methods utilize pyrene residues covalently attached to the peptide ends. The coil-to-beta-strand transitions in biosensor molecules cause elevation of a distinct fluorescence band of the pyrene aggregates (i.e. excimers). This approach enables the detection of infectious prion proteins at fmol, does not require antibody binding or protease treatment. Technology might be adopted for diagnosing a large variety of conformational disorders as well as for generic high-throughput screening of the amyloidogenic potential in plasma.

  17. Intensity-Modulated Radiation Therapy Improves the Target Coverage Over 3-D Planning While Meeting Lung Tolerance Doses for All Patients With Malignant Pleural Mesothelioma.

    Science.gov (United States)

    Ulger, Sukran; Cetin, Eren; Catli, Serap; Sarac, Hilal; Kilic, Diclehan; Bora, Huseyin

    2017-06-01

    To investigate high conformality on target coverage and the ability on creating strict lung dose limitation of intensity-modulated radiation therapy in malignant pleural mesothelioma. Twenty-four radiation therapy plannings were evaluated and compared with dosimetric outcomes of conformal radiation therapy and intensity-modulated radiation therapy. Hemithoracal radiation therapy was performed on 12 patients with a fraction of 1.8 Gy to a total dose of 50.4 Gy. All organs at risk were contoured. Radiotherapy plannings were differed according to the technique; conformal radiation therapy was planned with conventionally combined photon-electron fields, and intensity-modulated radiation therapy was planned with 7 to 9 radiation beam angles optimized in inverse planning. Strict dose-volume constraints were applied. Intensity-modulated radiation therapy was statistically superior in target coverage and dose homogeneity (intensity-modulated radiation therapy-planning target volume 95 mean 100%; 3-dimensional conformal radiation therapy-planning target volume 95 mean 71.29%, P = .0001; intensity-modulated radiation therapy-planning target volume 105 mean 11.14%; 3-dimensional conformal radiation therapy-planning target volume 105 mean 35.69%, P = .001). The dosimetric results of the remaining lung was below the limitations on intensity-modulated radiation therapy planning data (intensity-modulated radiation therapy-lung mean dose mean 7.5 [range: 5.6%-8.5%]; intensity-modulated radiation therapy-lung V5 mean 55.55% [range: 47%-59.9%]; intensity-modulated radiation therapy-lung V20 mean 4.5% [range: 0.5%-9.5%]; intensity-modulated radiation therapy-lung V13 mean 13.43% [range: 4.2%-22.9%]). With a complex and large target volume of malignant pleural mesothelioma, intensity-modulated radiation therapy has the ability to deliver efficient tumoricidal radiation dose within the safe dose limits of the remaining lung tissue.

  18. Probing RNA native conformational ensembles with structural constraints

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; van den Bedem, Henry; Bernauer, Julie

    2016-01-01

    substates, which are difficult to characterize experimentally and computationally. Here, we present an innovative, entirely kinematic computational procedure to efficiently explore the native ensemble of RNA molecules. Our procedure projects degrees of freedom onto a subspace of conformation space defined...... by distance constraints in the tertiary structure. The dimensionality reduction enables efficient exploration of conformational space. We show that the conformational distributions obtained with our method broadly sample the conformational landscape observed in NMR experiments. Compared to normal mode...

  19. A Dynamic Epistemic Framework for Conformant Planning

    Directory of Open Access Journals (Sweden)

    Quan Yu

    2016-06-01

    Full Text Available In this paper, we introduce a lightweight dynamic epistemic logical framework for automated planning under initial uncertainty. We reduce plan verification and conformant planning to model checking problems of our logic. We show that the model checking problem of the iteration-free fragment is PSPACE-complete. By using two non-standard (but equivalent semantics, we give novel model checking algorithms to the full language and the iteration-free language.

  20. Conformal Dynamics of Precursors to Fracture

    OpenAIRE

    Barra, Felipe; Herrera, Mauricio; Procaccia, Itamar

    2002-01-01

    An exact integro-differential equation for the conformal map from the unit circle to the boundary of an evolving cavity in a stressed 2-dimensional solid is derived. This equation provides an accurate description of the dynamics of precursors to fracture when surface diffusion is important. The solution predicts the creation of sharp grooves that eventually lead to material failure via rapid fracture. Solutions of the new equation are demonstrated for the dynamics of an elliptical cavity and ...

  1. Redox-Dependent Conformational Switching of Diphenylacetylenes

    Directory of Open Access Journals (Sweden)

    Ian M. Jones

    2014-07-01

    Full Text Available Herein we describe the design and synthesis of a redox-dependent single-molecule switch. Appending a ferrocene unit to a diphenylacetylene scaffold gives a redox-sensitive handle, which undergoes reversible one-electron oxidation, as demonstrated by cyclic voltammetry analysis. 1H-NMR spectroscopy of the partially oxidized switch and control compounds suggests that oxidation to the ferrocenium cation induces a change in hydrogen bonding interactions that results in a conformational switch.

  2. Theoretical studies on the conformations of selenamides

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Ab initio HF/6-31+G*, MP2/6-31+G*, B3LYP/6-31+G* level calculations have been performed on HSe–NH2 to estimate the Se–N rotational barriers and. N-inversion barriers. Two conformers have been found with syn and anti arrangement of the NH2 hydrogens with respect to Se–H bond. The N inversion barriers ...

  3. The Relationship of Conformity and Memory

    OpenAIRE

    Rogayeh Mohammadi, Gholam Hossein Javanmard

    2015-01-01

    Some theorists believe that the brain was evolved under the influence of the community and for the community. So it seems that social function has priority on pure cognitive in the brain. The purpose of this research was to study the relationship between conformity and general memory. The current study is a descriptive-correlational research by using prediction (regression) method. For doing this, 167 students were selected via the multistage cluster method from Bonab and Tabriz Payam Noor un...

  4. Abelian conformal field theory and determinant bundles

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Ueno, K.

    2007-01-01

    are up to a scale the same as the curvature of the connections constructed in [14, 16]. We study the sewing construction for nodal curves and its explicit relation to the constructed connections. Finally we construct preferred holomorphic sections of these line bundles and analyze their behaviour near...... nodal curves. These results are used in [4] to construct modular functors form the conformal field theories given in [14, 16] by twisting with an appropriate factional power of this Abelian theory....

  5. Conformational Dynamics and Allostery in Pyruvate Kinase.

    Science.gov (United States)

    Donovan, Katherine A; Zhu, Shaolong; Liuni, Peter; Peng, Fen; Kessans, Sarah A; Wilson, Derek J; Dobson, Renwick C J

    2016-04-22

    Pyruvate kinase catalyzes the final step in glycolysis and is allosterically regulated to control flux through the pathway. Two models are proposed to explain how Escherichia coli pyruvate kinase type 1 is allosterically regulated: the "domain rotation model" suggests that both the domains within the monomer and the monomers within the tetramer reorient with respect to one another; the "rigid body reorientation model" proposes only a reorientation of the monomers within the tetramer causing rigidification of the active site. To test these hypotheses and elucidate the conformational and dynamic changes that drive allostery, we performed time-resolved electrospray ionization mass spectrometry coupled to hydrogen-deuterium exchange studies followed by mutagenic analysis to test the activation mechanism. Global exchange experiments, supported by thermostability studies, demonstrate that fructose 1,6-bisphosphate binding to the allosteric domain causes a shift toward a globally more dynamic ensemble of conformations. Mapping deuterium exchange to peptides within the enzyme highlight site-specific regions with altered conformational dynamics, many of which increase in conformational flexibility. Based upon these and mutagenic studies, we propose an allosteric mechanism whereby the binding of fructose 1,6-bisphosphate destabilizes an α-helix that bridges the allosteric and active site domains within the monomeric unit. This destabilizes the β-strands within the (β/α)8-barrel domain and the linked active site loops that are responsible for substrate binding. Our data are consistent with the domain rotation model but inconsistent with the rigid body reorientation model given the increased flexibility at the interdomain interface, and we can for the first time explain how fructose 1,6-bisphosphate affects the active site. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Conformational Dynamics and Allostery in Pyruvate Kinase*

    Science.gov (United States)

    Donovan, Katherine A.; Zhu, Shaolong; Liuni, Peter; Peng, Fen; Kessans, Sarah A.; Wilson, Derek J.

    2016-01-01

    Pyruvate kinase catalyzes the final step in glycolysis and is allosterically regulated to control flux through the pathway. Two models are proposed to explain how Escherichia coli pyruvate kinase type 1 is allosterically regulated: the “domain rotation model” suggests that both the domains within the monomer and the monomers within the tetramer reorient with respect to one another; the “rigid body reorientation model” proposes only a reorientation of the monomers within the tetramer causing rigidification of the active site. To test these hypotheses and elucidate the conformational and dynamic changes that drive allostery, we performed time-resolved electrospray ionization mass spectrometry coupled to hydrogen-deuterium exchange studies followed by mutagenic analysis to test the activation mechanism. Global exchange experiments, supported by thermostability studies, demonstrate that fructose 1,6-bisphosphate binding to the allosteric domain causes a shift toward a globally more dynamic ensemble of conformations. Mapping deuterium exchange to peptides within the enzyme highlight site-specific regions with altered conformational dynamics, many of which increase in conformational flexibility. Based upon these and mutagenic studies, we propose an allosteric mechanism whereby the binding of fructose 1,6-bisphosphate destabilizes an α-helix that bridges the allosteric and active site domains within the monomeric unit. This destabilizes the β-strands within the (β/α)8-barrel domain and the linked active site loops that are responsible for substrate binding. Our data are consistent with the domain rotation model but inconsistent with the rigid body reorientation model given the increased flexibility at the interdomain interface, and we can for the first time explain how fructose 1,6-bisphosphate affects the active site. PMID:26879751

  7. Boundary conditions in conformal and integrable theories

    CERN Document Server

    Petkova, V B

    2000-01-01

    The study of boundary conditions in rational conformal field theories is not only physically important. It also reveals a lot on the structure of the theory ``in the bulk''. The same graphs classify both the torus and the cylinder partition functions and provide data on their hidden ``quantum symmetry''. The Ocneanu triangular cells -- the 3j-symbols of these symmetries, admit various interpretations and make a link between different problems.

  8. Opinion Dynamics and Wisdom under Conformity

    OpenAIRE

    Buechel, Berno; Hellmann, Tim; Kölßner, Stefan

    2014-01-01

    We present a model of opinion formation where individuals repeatedly engage in discussion and update their opinion in a social network similarly to the DeGroot model. Abstracting from the standard assumption that individuals always report their opinion truthfully, agents in our model may state an opinion that differs from their true opinion. The incentive to do so is induced by agents' preferences for conformity. We model opinion formation as a dynamic process and identify conditions for conv...

  9. Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy.

    Science.gov (United States)

    Goggin, L M; Descovich, M; McGuinness, C; Shiao, S; Pouliot, J; Park, C

    2016-06-01

    Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter

  10. Scale factor duality for conformal cyclic cosmologies

    Energy Technology Data Exchange (ETDEWEB)

    Silva, University Camara da; Lima, A.L. Alves; Sotkov, G.M. [Departamento de Física - CCE,Universidade Federal de Espirito Santo, 29075-900, Vitoria ES (Brazil)

    2016-11-16

    The scale factor duality is a symmetry of dilaton gravity which is known to lead to pre-big-bang cosmologies. A conformal time version of the scale factor duality (SFD) was recently implemented as a UV/IR symmetry between decelerated and accelerated phases of the post-big-bang evolution within Einstein gravity coupled to a scalar field. The problem investigated in the present paper concerns the employment of the conformal time SFD methods to the construction of pre-big-bang and cyclic extensions of these models. We demonstrate that each big-bang model gives rise to two qualitatively different pre-big-bang evolutions: a contraction/expansion SFD model and Penrose’s Conformal Cyclic Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving certain gauged Kähler sigma models minimally coupled to Einstein gravity are studied. We also describe the specific SFD features of the thermodynamics and the conditions for validity of the generalized second law in the case of Gauss-Bonnet (GB) extension of these selected CCC models.

  11. Implications of conformal invariance in momentum space

    Science.gov (United States)

    Bzowski, Adam; McFadden, Paul; Skenderis, Kostas

    2014-03-01

    We present a comprehensive analysis of the implications of conformal invariance for 3-point functions of the stress-energy tensor, conserved currents and scalar operators in general dimension and in momentum space. Our starting point is a novel and very effective decomposition of tensor correlators which reduces their computation to that of a number of scalar form factors. For example, the most general 3-point function of a conserved and traceless stress-energy tensor is determined by only five form factors. Dilatations and special conformal Ward identities then impose additional conditions on these form factors. The special conformal Ward identities become a set of first and second order differential equations, whose general solution is given in terms of integrals involving a product of three Bessel functions (`triple- K integrals'). All in all, the correlators are completely determined up to a number of constants, in agreement with well-known position space results. In odd dimensions 3-point functions are finite without renormalisation while in even dimensions non-trivial renormalisation in required. In this paper we restrict ourselves to odd dimensions. A comprehensive analysis of renormalisation will be discussed elsewhere. This paper contains two parts that can be read independently of each other. In the first part, we explain the method that leads to the solution for the correlators in terms of triple- K integrals while the second part contains a self-contained presentation of all results. Readers interested only in results may directly consult the second part of the paper.

  12. Spherically symmetric conformal gravity and "gravitational bubbles"

    CERN Document Server

    Berezin, V A; Eroshenko, Yu N

    2016-01-01

    The general structure of the spherically symmetric solutions in the Weyl conformal gravity is described. The corresponding Bach equation are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions is found. It consists of two classes. The first one contains the solutions with constant two-dimensional curvature scalar of our specific metrics, and the representatives are the famous Robertson-Walker metrics. One of them we called the "gravitational bubbles", which is compact and with zero Weyl tensor. The second class is more general, with varying curvature scalar. We found its representative as the one-parameter family. It appears that it can be conformally covered by the thee-parameter Mannheim-Kazanas solution. We also investigated the general structure of the energy-momentum tensor in the spherical conformal gravity and constructed the vectorial equation that reveals clearly the same features of non-vacuum solu...

  13. Compact conformations of human protein disulfide isomerase.

    Directory of Open Access Journals (Sweden)

    Shang Yang

    Full Text Available Protein disulfide isomerase (PDI composed of four thioredoxin-like domains a, b, b', and a', is a key enzyme catalyzing oxidative protein folding in the endoplasmic reticulum. Large scale molecular dynamics simulations starting from the crystal structures of human PDI (hPDI in the oxidized and reduced states were performed. The results indicate that hPDI adopts more compact conformations in solution than in the crystal structures, which are stabilized primarily by inter-domain interactions, including the salt bridges between domains a and b' observed for the first time. A prominent feature of the compact conformations is that the two catalytic domains a and a' can locate close enough for intra-molecular electron transfer, which was confirmed by the characterization of an intermediate with a disulfide between the two domains. Mutations, which disrupt the inter-domain interactions, lead to decreased reductase activity of hPDI. Our molecular dynamics simulations and biochemical experiments reveal the intrinsic conformational dynamics of hPDI and its biological impact.

  14. Scale factor duality for conformal cyclic cosmologies

    Science.gov (United States)

    Camara da Silva, U.; Alves Lima, A. L.; Sotkov, G. M.

    2016-11-01

    The scale factor duality is a symmetry of dilaton gravity which is known to lead to pre-big-bang cosmologies. A conformal time version of the scale factor duality (SFD) was recently implemented as a UV/IR symmetry between decelerated and accelerated phases of the post-big-bang evolution within Einstein gravity coupled to a scalar field. The problem investigated in the present paper concerns the employment of the conformal time SFD methods to the construction of pre-big-bang and cyclic extensions of these models. We demonstrate that each big-bang model gives rise to two qualitatively different pre-big-bang evolutions: a contraction/expansion SFD model and Penrose's Conformal Cyclic Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving certain gauged Kähler sigma models minimally coupled to Einstein gravity are studied. We also describe the specific SFD features of the thermodynamics and the conditions for validity of the generalized second law in the case of Gauss-Bonnet (GB) extension of these selected CCC models.

  15. Deep Inelastic Scattering in Conformal QCD

    CERN Document Server

    Cornalba, Lorenzo; Penedones, Joao

    2010-01-01

    We consider the Regge limit of a CFT correlation function of two vector and two scalar operators, as appropriate to study small-x deep inelastic scattering in N=4 SYM or in QCD assuming approximate conformal symmetry. After clarifying the nature of the Regge limit for a CFT correlator, we use its conformal partial wave expansion to obtain an impact parameter representation encoding the exchange of a spin j Reggeon for any value of the coupling constant. The CFT impact parameter space is the three-dimensional hyperbolic space H3, which is the impact parameter space for high energy scattering in the dual AdS space. We determine the small-x structure functions associated to the exchange of a Reggeon. We discuss unitarization from the point of view of scattering in AdS and comment on the validity of the eikonal approximation. We then focus on the weak coupling limit of the theory where the amplitude is dominated by the exchange of the BFKL pomeron. Conformal invariance fixes the form of the vector impact factor a...

  16. An event-based account of conformity.

    Science.gov (United States)

    Kim, Diana; Hommel, Bernhard

    2015-04-01

    People often change their behavior and beliefs when confronted with deviating behavior and beliefs of others, but the mechanisms underlying such phenomena of conformity are not well understood. Here we suggest that people cognitively represent their own actions and others' actions in comparable ways (theory of event coding), so that they may fail to distinguish these two categories of actions. If so, other people's actions that have no social meaning should induce conformity effects, especially if those actions are similar to one's own actions. We found that female participants adjusted their manual judgments of the beauty of female faces in the direction consistent with distracting information without any social meaning (numbers falling within the range of the judgment scale) and that this effect was enhanced when the distracting information was presented in movies showing the actual manual decision-making acts. These results confirm that similarity between an observed action and one's own action matters. We also found that the magnitude of the standard conformity effect was statistically equivalent to the movie-induced effect. © The Author(s) 2015.

  17. Salmon calcitonin: conformational changes and stabilizer effects

    Directory of Open Access Journals (Sweden)

    Shan-Yang Lin

    2015-11-01

    Full Text Available The therapeutic activity of peptides or protein drugs is highly dependent on their conformational structure. The protein structure is flexible and responds to external conditions, which may compromise the protein's native conformation and influence its physical and chemical stability. The physical and chemical stability of peptides or protein drugs are important characteristics of biopharmaceutical products. Calcitonin (CT is a polypeptide hormone that participates in diverse physiological functions in humans; therefore, it is a potentially useful protein for investigations of different aspects of pharmacology and drug delivery systems. Of the different types of CT available for clinical use, salmon CT (sCT is one of the most potent. In this review article, the commercially available sCT was selected as a suitable peptide candidate for the discussion of its stability and conformational changes in the aqueous and solid states using Fourier transform infrared (FTIR spectroscopic analysis under different external conditions, including pH, temperature, drying method, and added excipients. Particularly, excipients that have been optimized as stabilizers of sCT in aqueous solution and as lyophilized and spray-dried drug formulations are also discussed.

  18. The herding hormone: Oxytocin stimulates in-group conformity

    NARCIS (Netherlands)

    Stallen, M.; de Dreu, C.K.W.; Shalvi, S.; Smidts, A.; Sanfey, A.G.

    2012-01-01

    People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one’s in-group is altered by oxytocin, a neuropeptide often implicated in social

  19. The herding hormone: Oxytocin stimulates in-group conformity

    NARCIS (Netherlands)

    Stallen, M.; Dreu, C.K.W. de; Shalvi, S.; Smidts, A.; Sanfey, A.G.

    2012-01-01

    People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one's in-group is altered by oxytocin, a neuropeptide often implicated in social

  20. A Mediated Moderation Model of Conformative Peer Bullying

    Science.gov (United States)

    Cho, Yoonju; Chung, Ock-Boon

    2012-01-01

    We investigated the relationship between conformative peer bullying and issues of peer conformity among adolescents. This relationship is examined through the establishment of a mediated moderation model for conformative peer bullying using structural equation modeling in a sample of 391 second-year middle school students in Seoul, South Korea. We…

  1. Peer influence: neural mechanisms underlying in-group conformity

    NARCIS (Netherlands)

    Stallen, M.; Smidts, A.; Sanfey, A.G.

    2013-01-01

    People often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI). Participants completed

  2. 45 CFR 1355.34 - Criteria for determining substantial conformity.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Criteria for determining substantial conformity... GENERAL § 1355.34 Criteria for determining substantial conformity. (a) Criteria to be satisfied. ACF will determine a State's substantial conformity with title IV-B and title IV-E State plan requirements based on...

  3. 40 CFR 89.105 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 89.105... and Certification Provisions § 89.105 Certificate of conformity. Every manufacturer of a new nonroad compression-ignition engine must obtain a certificate of conformity covering the engine family, as described...

  4. Standing in the Hallway Improves Students' Understanding of Conformity

    Science.gov (United States)

    Lawson, Timothy J.; Haubner, Richard R.; Bodle, James H.

    2013-01-01

    To help beginning psychology students understand how they are influenced by social pressures to conform, we developed a demonstration designed to elicit their conformity to a small group of students standing in the hallway before class. Results showed the demonstration increased students' recognition of their own tendency to conform, knowledge of…

  5. 40 CFR 86.407-78 - Certificate of conformity required.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Certificate of conformity required. 86... Regulations for 1978 and Later New Motorcycles, General Provisions § 86.407-78 Certificate of conformity... conformity issued pursuant to this subpart, except as specified in paragraph (b) of this section, or...

  6. 14 CFR 21.130 - Statement of conformity.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Statement of conformity. 21.130 Section 21... conformity. Each holder or licensee of a type certificate only, for a product manufactured in the United... Administrator a statement of conformity (FAA Form 317). This statement must be signed by an authorized person...

  7. 40 CFR 90.106 - Certificate of conformity.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Certificate of conformity. 90.106... Standards and Certification Provisions § 90.106 Certificate of conformity. (a)(1) Except as provided in § 90... certificate of conformity covering such engines; however, engines manufactured during an annual production...

  8. 14 CFR 21.53 - Statement of conformity.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Statement of conformity. 21.53 Section 21... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.53 Statement of conformity. Link to an... conformity (FAA Form 317) to the Administrator for each aircraft engine and propeller presented to the...

  9. 20 CFR 604.6 - Conformity and substantial compliance.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Conformity and substantial compliance. 604.6... FOR ELIGIBILITY FOR UNEMPLOYMENT COMPENSATION § 604.6 Conformity and substantial compliance. (a) In... for the administration of its UC program. (b) Resolving Issues of Conformity and Substantial...

  10. Peer influence: Neural mechanisms underlying in-group conformity

    NARCIS (Netherlands)

    M. Stallen (Mirre); A. Smidts (Ale); A.G. Sanfey (Alan)

    2013-01-01

    textabstractPeople often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI).

  11. 75 FR 14259 - Transportation Conformity Rule PM2.5

    Science.gov (United States)

    2010-03-24

    ... Protection Agency 40 CFR Part 93 Transportation Conformity Rule PM2.5 and PM10 Amendments; Final Rule #0;#0...; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 93 RIN 2060-AP29 Transportation Conformity Rule PM 2.5 and PM 10... amending the transportation conformity rule to finalize provisions that were proposed on May 15, 2009...

  12. 49 CFR 577.9 - Conformity to statutory requirements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Conformity to statutory requirements. 577.9 Section 577.9 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... NOTIFICATION § 577.9 Conformity to statutory requirements. A notification that does not conform to the...

  13. Ras conformational switching: simulating nucleotide-dependent conformational transitions with accelerated molecular dynamics.

    Directory of Open Access Journals (Sweden)

    Barry J Grant

    2009-03-01

    Full Text Available Ras mediates signaling pathways controlling cell proliferation and development by cycling between GTP- and GDP-bound active and inactive conformational states. Understanding the complete reaction path of this conformational change and its intermediary structures is critical to understanding Ras signaling. We characterize nucleotide-dependent conformational transition using multiple-barrier-crossing accelerated molecular dynamics (aMD simulations. These transitions, achieved for the first time for wild-type Ras, are impossible to observe with classical molecular dynamics (cMD simulations due to the large energetic barrier between end states. Mapping the reaction path onto a conformer plot describing the distribution of the crystallographic structures enabled identification of highly populated intermediate structures. These structures have unique switch orientations (residues 25-40 and 57-75 intermediate between GTP and GDP states, or distinct loop3 (46-49, loop7 (105-110, and alpha5 C-terminus (159-166 conformations distal from the nucleotide-binding site. In addition, these barrier-crossing trajectories predict novel nucleotide-dependent correlated motions, including correlations of alpha2 (residues 66-74 with alpha3-loop7 (93-110, loop2 (26-37 with loop10 (145-151, and loop3 (46-49 with alpha5 (152-167. The interconversion between newly identified Ras conformations revealed by this study advances our mechanistic understanding of Ras function. In addition, the pattern of correlated motions provides new evidence for a dynamic linkage between the nucleotide-binding site and the membrane interacting C-terminus critical for the signaling function of Ras. Furthermore, normal mode analysis indicates that the dominant collective motion that occurs during nucleotide-dependent conformational exchange, and captured in aMD (but absent in cMD simulations, is a low-frequency motion intrinsic to the structure.

  14. Exploring the conformational space of cysteine by matrix isolation spectroscopy combined with near-infrared laser induced conformational change.

    Science.gov (United States)

    Najbauer, Eszter E; Bazsó, Gábor; Góbi, Sándor; Magyarfalvi, Gábor; Tarczay, György

    2014-02-27

    Six conformers of α-cysteine were identified by matrix isolation IR spectroscopy combined with NIR laser irradiation. Five of these conformers are identical with the five out of six conformers that have recently been identified by microwave spectroscopy. The sixth conformer observed in the present study is a short-lived conformer, which decays by H-atom tunneling; its half-life in a 12 K N2 matrix is (1.1 ± 0.5) × 10(3) s. This study proves that matrix isolation IR spectroscopy combined with NIR laser irradiation is a suitable method to identify conformers of a complex system for which computations predict several dozens of conformers, and that the reliability of this method for conformational assignment is comparable to that of microwave spectroscopy.

  15. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  16. Radiation Therapy (For Parents)

    Science.gov (United States)

    ... Giving Teens a Voice in Health Care Decisions Radiation Therapy KidsHealth > For Parents > Radiation Therapy Print A ... have many questions and concerns about it. About Radiation Therapy In radiation therapy, high-energy radiation from ...

  17. Abdominal radiation - discharge

    Science.gov (United States)

    Radiation - abdomen - discharge; Cancer - abdominal radiation; Lymphoma - abdominal radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after radiation treatment starts, you might notice changes ...

  18. The Coleman-Weinberg mechanism in a conformal (Weyl) invariant theory: application to a magnetic monopole

    Science.gov (United States)

    Edery, Ariel; Graham, Noah

    2015-05-01

    We consider a massless conformally (Weyl) invariant classical action consisting of a magnetic monopole coupled to gravity in an anti-de Sitter background spacetime. We implement quantum corrections and this breaks the conformal (Weyl) symmetry, introduces a length scale via the process of renormalization and leads to the trace anomaly. We calculate the one-loop effective potential and determine from it the vacuum expectation value (VEV). Spontaneous symmetry breaking is radiatively induced a la Coleman-Weinberg and the scalar coupling constant is exchanged for the dimensionful VEV via dimensional transmutation. An important result is that the Ricci scalar of the AdS background spacetimeis determined entirely by the value of the VEV.

  19. Big bounce, slow-roll inflation, and dark energy from conformal gravity

    Science.gov (United States)

    Gegenberg, Jack; Rahmati, Shohreh; Seahra, Sanjeev S.

    2017-02-01

    We examine the cosmological sector of a gauge theory of gravity based on the SO(4,2) conformal group of Minkowski space. We allow for conventional matter coupled to the spacetime metric as well as matter coupled to the field that gauges special conformal transformations. An effective vacuum energy appears as an integration constant, and this allows us to recover the late time acceleration of the Universe. Furthermore, gravitational fields sourced by ordinary cosmological matter (i.e. dust and radiation) are significantly weakened in the very early Universe, which has the effect of replacing the big bang with a big bounce. Finally, we find that this bounce is followed by a period of nearly exponential slow roll inflation that can last long enough to explain the large scale homogeneity of the cosmic microwave background.

  20. Logarithmic conformal field theory: beyond an introduction

    Science.gov (United States)

    Creutzig, Thomas; Ridout, David

    2013-12-01

    This article aims to review a selection of central topics and examples in logarithmic conformal field theory. It begins with the remarkable observation of Cardy that the horizontal crossing probability of critical percolation may be computed analytically within the formalism of boundary conformal field theory. Cardy’s derivation relies on certain implicit assumptions which are shown to lead inexorably to indecomposable modules and logarithmic singularities in correlators. For this, a short introduction to the fusion algorithm of Nahm, Gaberdiel and Kausch is provided. While the percolation logarithmic conformal field theory is still not completely understood, there are several examples for which the formalism familiar from rational conformal field theory, including bulk partition functions, correlation functions, modular transformations, fusion rules and the Verlinde formula, has been successfully generalized. This is illustrated for three examples: the singlet model \\mathfrak {M} (1,2), related to the triplet model \\mathfrak {W} (1,2), symplectic fermions and the fermionic bc ghost system; the fractional level Wess-Zumino-Witten model based on \\widehat{\\mathfrak {sl}} \\left( 2 \\right) at k=-\\frac{1}{2}, related to the bosonic βγ ghost system; and the Wess-Zumino-Witten model for the Lie supergroup \\mathsf {GL} \\left( 1 {\\mid} 1 \\right), related to \\mathsf {SL} \\left( 2 {\\mid} 1 \\right) at k=-\\frac{1}{2} and 1, the Bershadsky-Polyakov algebra W_3^{(2)} and the Feigin-Semikhatov algebras W_n^{(2)}. These examples have been chosen because they represent the most accessible, and most useful, members of the three best-understood families of logarithmic conformal field theories. The logarithmic minimal models \\mathfrak {W} (q,p), the fractional level Wess-Zumino-Witten models, and the Wess-Zumino-Witten models on Lie supergroups (excluding \\mathsf {OSP} \\left( 1 {\\mid} 2n \\right)). In this review, the emphasis lies on the representation theory

  1. Radiation related basic cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hoon; Yoo, Young Do; Hong, Seok Il [and others

    2000-04-01

    We studied the mechanism of radiation-induced apoptosis, the factors involved signaling, and the establishment of radiation-resistant cell lines in this study. During the TGF beta-stimulated epithelial mesenchymal transition(EMT), actin rearrangement occurred first and fibronectin matrix assembly followed. These two events were considered independent since cytochalasin-D did not inhibit TGF stimulated matrix assembly and fibronectin supplementation did not induce EMT. During EMT, alpha 5 beta 1 integrin and alpha v integrin have increased but MMP activation was not accompanied, which suggest that induction of extracellular matrix and activation of integrins may be main contributor for the EMT. Serum depriving induced apoptosis of HUVECs was prevented by vascular endothelial growth factor(VEGF) and PMA. The apoptosis prevention by VEGF and PMA were conformed by DNA fragmentation assay. The p53 expression level was down regulated by VEGF and PMA compared with serum deprived HUVECs. However, VEGF and PMA induces c-Myc expression level on these cells. We made the 5 radiation-resistant clones from breast, lung and cervical cancer cells. More than 70%, 100% and 50% increased resistance was detected in breast cancer cells, lung cancer cells, and cervical cells, respectively. We carried out differential display-PCR to clone the radiation-resistant genes. 9 out of 10 genes were analyzed their sequence.

  2. Radiation myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, I.A.; Myers, S.J.

    1976-02-01

    Myelopathy secondary to radiation is a relatively uncommon entity which was reported initially in 1941 by Ahlbom. From a total of 65 patients who were seen in our spinal injury clinic during the past four years, three patients have received a diagnosis of radiation myelopathy. This is 4.6 percent of the total number. The case histories of two patients with radiation myelopathy are presented. The clinical and pathologic features are discussed. Since the three patients with this diagnosis whose cases are followed in the clinic are still alive, the second case that is reported is taken from the files of the pathology department so that autopsy and histologic data also can be presented.

  3. Directional radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  4. Conformal Microwave Array (CMA) Applicators for Hyperthermia of Diffuse Chestwall Recurrence

    Science.gov (United States)

    Stauffer, Paul R.; Maccarini, Paolo; Arunachalam, Kavitha; Craciunescu, Oana; Diederich, Chris; Juang, Titania; Rossetto, Francesca; Schlorff, Jaime; Milligan, Andrew; Hsu, Joe; Sneed, Penny; Vujaskovic, Zeljko

    2010-01-01

    Purpose This article summarizes the evolution of microwave array applicators for heating large area chestwall disease as an adjuvant to external beam radiation, systemic chemotherapy, and potentially simultaneous brachytherapy. Methods Current devices used for thermotherapy of chestwall recurrence are reviewed. The largest conformal array applicator to date is evaluated in four studies: i) ability to conform to the torso is demonstrated with a CT scan of a torso phantom and MR scan of the conformal waterbolus component on a mastectomy patient; ii) Specific Absorption Rate (SAR) and temperature distributions are calculated with electromagnetic and thermal simulation software for a mastectomy patient; iii). SAR patterns are measured with a scanning SAR probe in liquid muscle phantom for a buried coplanar waveguide CMA; and iv) heating patterns and patient tolerance of CMA applicators are characterized in a clinical pilot study with 13 patients. Results CT and MR scans demonstrate excellent conformity of CMA applicators to contoured anatomy. Simulations demonstrate effective control of heating over contoured anatomy. Measurements confirm effective coverage of large treatment areas with no gaps. In 42 hyperthermia treatments, CMA applicators provided well-tolerated effective heating of up to 500cm2 regions, achieving target temperatures of Tmin=41.4±0.7°C, T90=42.1±0.6°C, Tave=42.8±0.6°C, and Tmax=44.3±0.8°C as measured in an average of 90 points per treatment. Summary The CMA applicator is an effective thermal therapy device for heating large-area superficial disease such as diffuse chestwall recurrence. It is able to cover over three times the treatment area of conventional hyperthermia devices while conforming to typical body contours. PMID:20849262

  5. Actors conform, observers react: the effects of behavioral synchrony on conformity.

    Science.gov (United States)

    Dong, Ping; Dai, Xianchi; Wyer, Robert S

    2015-01-01

    Engaging in synchronous behavior can induce a more general disposition to copy others, which increases the tendency to conform to others' preferences in an unrelated choice situation. In contrast, observing others perform synchronous behavior can induce psychological reactance and decrease conformity to others' preferences. Five experiments confirmed these different effects and circumscribed the conditions in which they occurred. Actors typically focus their attention on the goal to which their synchronous behavior is directed, inducing a copying-others mindset that generalizes to later situations. In contrast, observers focus on the actors' behavior independently of the goal to which it pertains. Consequently, they become sensitive to the restrictions on freedom that synchronous behavior requires and experience reactance. However, changing the relative attention that actors and observers pay to these factors can reverse the effects of the actors' synchronous behavior on conformity. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  6. Ligand-induced conformational changes: Improved predictions of ligand binding conformations and affinities

    DEFF Research Database (Denmark)

    Frimurer, T.M.; Peters, Günther H.J.; Iversen, L.F.

    2003-01-01

    A computational docking strategy using multiple conformations of the target protein is discussed and evaluated. A series of low molecular weight, competitive, nonpeptide protein tyrosine phosphatase inhibitors are considered for which the x-ray crystallographic structures in complex with protein...... tyrosine phosphatase 1 B (PTP1B) are known. To obtain a quantitative measure of the impact of conformational changes induced by the inhibitors, these were docked to the active site region of various structures of PTP1B using the docking program FlexX. Firstly, the inhibitors were docked to a PTP1B crystal...... predicted binding energy and a correct docking mode. Thirdly, to improve the predictability of the docking procedure in the general case, where only a single target protein structure is known, we evaluate an approach which takes possible protein side-chain conformational changes into account. Here, side...

  7. Peer influence: Neural mechanisms underlying in-group conformity

    Directory of Open Access Journals (Sweden)

    Mirre eStallen

    2013-03-01

    Full Text Available People often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI. Participants completed a perceptual decision-making task while undergoing fMRI, during which they were exposed to the judgments of both in-group and out-group members. Our data suggest that conformity to the in-group is mediated by both positive affect as well as the cognitive capacity of perspective taking. Examining the processes that drive in-group conformity by utilizing a basic decision-making paradigm combined with neuroimaging methods provides important insights into the potential mechanisms of conformity. These results may provide an integral step in developing more effective campaigns using group conformity as a tool for behavioral change.

  8. Invariant classification of second-order conformally flat superintegrable systems

    Science.gov (United States)

    Capel, J. J.; Kress, J. M.

    2014-12-01

    In this paper we continue the work of Kalnins et al in classifying all second-order conformally-superintegrable (Laplace-type) systems over conformally flat spaces, using tools from algebraic geometry and classical invariant theory. The results obtained show, through Stäckel equivalence, that the list of known nondegenerate superintegrable systems over three-dimensional conformally flat spaces is complete. In particular, a seven-dimensional manifold is determined such that each point corresponds to a conformal class of superintegrable systems. This manifold is foliated by the nonlinear action of the conformal group in three dimensions. Two systems lie in the same conformal class if and only if they lie in the same leaf of the foliation. This foliation is explicitly described using algebraic varieties formed from representations of the conformal group. The proof of these results rely heavily on Gröbner basis calculations using the computer algebra software packages Maple and Singular.

  9. An explicit-solvent conformation search method using open software

    Directory of Open Access Journals (Sweden)

    Kari Gaalswyk

    2016-05-01

    Full Text Available Computer modeling is a popular tool to identify the most-probable conformers of a molecule. Although the solvent can have a large effect on the stability of a conformation, many popular conformational search methods are only capable of describing molecules in the gas phase or with an implicit solvent model. We have developed a work-flow for performing a conformation search on explicitly-solvated molecules using open source software. This method uses replica exchange molecular dynamics (REMD to sample the conformational states of the molecule efficiently. Cluster analysis is used to identify the most probable conformations from the simulated trajectory. This work-flow was tested on drug molecules α-amanitin and cabergoline to illustrate its capabilities and effectiveness. The preferred conformations of these molecules in gas phase, implicit solvent, and explicit solvent are significantly different.

  10. Peer influence: neural mechanisms underlying in-group conformity.

    Science.gov (United States)

    Stallen, Mirre; Smidts, Ale; Sanfey, Alan G

    2013-01-01

    People often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI). Participants completed a perceptual decision-making task while undergoing fMRI, during which they were exposed to the judgments of both in-group and out-group members. Our data suggest that conformity to the in-group is mediated by both positive affect as well as the cognitive capacity of perspective taking. Examining the processes that drive in-group conformity by utilizing a basic decision-making paradigm combined with neuroimaging methods provides important insights into the potential mechanisms of conformity. These results may provide an integral step in developing more effective campaigns using group conformity as a tool for behavioral change.

  11. Patterns and conformations in molecularly thin films

    Science.gov (United States)

    Basnet, Prem B.

    Molecularly thin films have been a subject of great interest for the last several years because of their large variety of industrial applications ranging from micro-electronics to bio-medicine. Additionally, molecularly thin films can be used as good models for biomembrane and other systems where surfaces are critical. Many different kinds of molecules can make stable films. My research has considered three such molecules: a polymerizable phospholipid, a bent-core molecules, and a polymer. One common theme of these three molecules is chirality. The phospolipid molecules studied here are strongly chiral, which can be due to intrinsically chiral centers on the molecules and also due to chiral conformations. We find that these molecules give rise to chiral patterns. Bent-core molecules are not intrinsically chiral, but individual molecules and groups of molecules can show chiral structures, which can be changed by surface interactions. One major, unconfirmed hypothesis for the polymer conformation at surface is that it forms helices, which would be chiral. Most experiments were carried out at the air/water interface, in what are called Langmuir films. Our major tools for studying these films are Brewster Angle Microscopy (BAM) coupled with the thermodynamic information that can be deduced from surface pressure isotherms. Phospholipids are one of the important constituents of liposomes -- a spherical vesicle com-posed of a bilayer membrane, typically composed of a phospholipid and cholesterol bilayer. The application of liposomes in drug delivery is well-known. Crumpling of vesicles of polymerizable phospholipids has been observed. With BAM, on Langmuir films of such phospholipids, we see novel spiral/target patterns during compression. We have found that both the patterns and the critical pressure at which they formed depend on temperature (below the transition to a i¬‘uid layer). Bent-core liquid crystals, sometimes knows as banana liquid crystals, have drawn

  12. Induction and Processing of the Radiation-Induced Gamma-H2AX Signal and Its Link to the Underlying Pattern of DSB: A Combined Experimental and Modelling Study.

    Directory of Open Access Journals (Sweden)

    Francesco Tommasino

    , experiments performed at high doses are of relevance in the context of radiation therapy, where hypo-fractionated schemes become increasingly popular.

  13. Development of clinical application of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun [and others

    2000-04-01

    The aim is to develop the clinical radiation therapy techniques, which increase local control and cure rate of cancer. The contents were 1. technique of stereotactic radiotherapy 2. technique of intraoperative radiation therapy(IORT) 3. technique of fractionated radiotherapy 4. technique of 3D conformal therapy 5. chemoradiotherapy in lung cancer, rectal cancer and biliopancreatic cancer 6. network based information communication system of radiation oncology 7. animal studies for the best application of chemoradiotherapy and for elucidating mechanism of slide effect in radiotherapy. The results were 1. completion of quality assurance protocol, frame and mounting system 2. completion of applicator of IORT 3. clinical protocol of fractionated radiotherapy 4. clinical protocol of 3D conformal therapy for brain, head and neck, breast and lung cancer 5. completion of multimodality treatment protocol for lung, rectal and biliopancreatic cancer 6. completion of database system for patient information and simulation image 7. standardization of estimation for radiation induced pneumonitis in animal model. Future plans are (1) developed fractionated stereotactic radiotherapy system will be commercialized (2) developed applicator of brachytherapy for IORT will be commercialized (3) 3D conformal therapy will increase local control rate for brain tumor and decrease complications such as zerostomia after treatment for nasopharygeal cancer (4) training manpower and skills for randomized clinical trial (5) suggest possibility of clinical usefulness of oral 5-fluorouracil (6) to provide basic technique for electric chart (7) promote developing database system for image information (8) also in view of double edge sword effect of NO, it is possible to modify the NO production from irradiation to increase the tolerance to radiation.

  14. Conformal refinement of unstructured quadrilateral meshes

    Energy Technology Data Exchange (ETDEWEB)

    Garmella, Rao [Los Alamos National Laboratory

    2009-01-01

    We present a multilevel adaptive refinement technique for unstructured quadrilateral meshes in which the mesh is kept conformal at all times. This means that the refined mesh, like the original, is formed of only quadrilateral elements that intersect strictly along edges or at vertices, i.e., vertices of one quadrilateral element do not lie in an edge of another quadrilateral. Elements are refined using templates based on 1:3 refinement of edges. We demonstrate that by careful design of the refinement and coarsening strategy, we can maintain high quality elements in the refined mesh. We demonstrate the method on a number of examples with dynamically changing refinement regions.

  15. Energy of knots and conformal geometry

    CERN Document Server

    O'Hara, Jun

    2003-01-01

    Energy of knots is a theory that was introduced to create a "canonical configuration" of a knot - a beautiful knot which represents its knot type. This book introduces several kinds of energies, and studies the problem of whether or not there is a "canonical configuration" of a knot in each knot type. It also considers this problems in the context of conformal geometry. The energies presented in the book are defined geometrically. They measure the complexity of embeddings and have applications to physical knotting and unknotting through numerical experiments. Contents: In Search of the "Optima

  16. Holographic collisions in non-conformal theories

    Science.gov (United States)

    Attems, Maximilian; Casalderrey-Solana, Jorge; Mateos, David; Santos-Oliván, Daniel; Sopuerta, Carlos F.; Triana, Miquel; Zilhão, Miguel

    2017-01-01

    We numerically simulate gravitational shock wave collisions in a holographic model dual to a non-conformal four-dimensional gauge theory. We find two novel effects associated to the non-zero bulk viscosity of the resulting plasma. First, the hydrodynamization time increases. Second, if the bulk viscosity is large enough then the plasma becomes well described by hydrodynamics before the energy density and the average pressure begin to obey the equilibrium equation of state. We discuss implications for the quark-gluon plasma created in heavy ion collision experiments.

  17. Charged C-metric in conformal gravity

    CERN Document Server

    Lim, Yen-Kheng

    2016-01-01

    Using a C-metric-type ansatz, we obtain an exact solution to conformal gravity coupled to a Maxwell electromagnetic field. The solution resembles a C-metric spacetime carrying an electromagnetic charge. The metric is cast in a factorised form which allows us to study the domain structure of its static coordinate regions. This metric reduces to the well-known Mannheim-Kazanas metric under an appropriate limiting procedure, and also reduces to the (Anti-)de Sitter C-metric of Einstein gravity for a particular choice of parameters.

  18. Conformable fractional Dirac system on time scales.

    Science.gov (United States)

    Gulsen, Tuba; Yilmaz, Emrah; Goktas, Sertac

    2017-01-01

    We study the conformable fractional (CF) Dirac system with separated boundary conditions on an arbitrary time scale [Formula: see text]. Then we extend some basic spectral properties of the classical Dirac system to the CF case. Eventually, some asymptotic estimates for the eigenfunction of the CF Dirac eigenvalue problem are obtained on [Formula: see text]. So, we provide a constructive procedure for the solution of this problem. These results are important steps to consolidate the link between fractional calculus and time scale calculus in spectral theory.

  19. DEFECT ASSESSMENT USING CONFORMABLE ARRAY DATA

    Energy Technology Data Exchange (ETDEWEB)

    Alfred E. Crouch; Todd H. Goyen

    2003-12-01

    This report covers the design and fabrication of a conformable eddy current array useful for the mapping and measurement of external corrosion on a transmission pipeline. The feasibility of the basic measuring approach was demonstrated and the general guidelines for sensor design were disclosed in a previous project. This project was concerned with design of a practical array, development of interface electronics, and design of the operation and analysis software. A prototype system was constructed, checked out, and demonstrated on natural corrosion in a field environment.

  20. Liver late effects of ionizing radiation; Effets tardifs des radiations sur le foie

    Energy Technology Data Exchange (ETDEWEB)

    Mornex, F.; Ramuz, O. [Centre Hospitalier Universitaire Lyon-Sud, 69 - Pierre-Benite (France); Gerard, F. [Laboratoire Marcel-Merieux, 69 - Lyon (France); Van Houtte, P. [Institut Bordet, Brussels (Belgium)

    1997-12-01

    Until recently, the liver was classified as a radioresistant organ, although it is in fact highly radiosensitive. The realization that the whole liver could be treated safety only with low doses of radiation led to the conclusion that radiation therapy had an extremely limited role in the treatment of intrahepatic malignancies. A resurgence of interest has been observed with the advent of conformal radiotherapy and the introduction of bone marrow transplantation with total body irradiation. The radiation-induced liver disease, often called radiation hepatitis, is a syndrome characterized by the development of anicteric ascites, approximately 2 weeks to 4 months after hepatic irradiation. Immediate tolerance is generally surprisingly good, and the subacute radiation injury is followed by a complete asymptomatic healing, although the late lesions may be associated with signs of chronic radiation hepatitis. Radiation hepatitis must be distinguished from chemo-radiation-induced-hepatitis occurring in patients undergoing bone marrow transplantation and total body irradiation. Both syndromes demonstrate the same pathological lesion: veno-occlusive disease. The main treatment for radiation hepatitis is diuretics, although soma advocate steroids for severe cases. (authors)

  1. Introduction to Radiotherapy with Photon and Electron Beams and Treatment Planning from Conformal Radiotherapy to IMRT

    Science.gov (United States)

    Wilkens, Jan J.

    2007-11-01

    Besides surgery and chemotherapy, radiation therapy is one of the three main treatment options for cancer patients. This paper provides an introduction to the basic principles of radiotherapy with photons and electrons. It includes a brief summary of the physical properties for photon and electron beams as well as a description of treatment machines used to create these beams. The second part introduces the treatment planning process as it is commonly employed in radiotherapy. It covers dose calculation algorithms, conventional planning strategies for three-dimensional conformal radiotherapy, and optimization techniques for intensity modulated radiotherapy (IMRT).

  2. Radiation oncology in the era of precision medicine

    DEFF Research Database (Denmark)

    Baumann, Michael; Krause, Mechthild; Overgaard, Jens

    2016-01-01

    with preservation of health-related quality of life can be achieved in many patients. Two major strategies, acting synergistically, will enable further widening of the therapeutic window of radiation oncology in the era of precision medicine: technology-driven improvement of treatment conformity, including advanced...

  3. [Dynamics of biomacromolecules in coherent electromagnetic radiation field].

    Science.gov (United States)

    Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I

    2014-01-01

    It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.

  4. [Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

    Science.gov (United States)

    Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

    2017-10-01

    Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  5. CONSERVATIVE TREATMENT IN LOCALLY AND LOCALLY-ADVANCED PROSTATE CANCER USING CONFORMAL RADIOTHERAPY

    Directory of Open Access Journals (Sweden)

    Tkachev Sergey Ivanovich

    2013-01-01

    Full Text Available The combination of androgen deprivation and radiotherapy increase the probability of diseases full regresses and survival rate. Modern technical and technological opportunities of 3D CRT allow to increase total dose to prostate up to 72-76Gy vs. radiotherapy of 66-70Gy. In this study we compare the rates of post radiation toxicity and the efficiency of treatment for the patients receiving conventional radiotherapy and 3D CRT. The use of 3D CRT has not only result to increase of 10-years recurrence free survival rate from 74% (I grope to 86,5% (II grope, р=0,01, but also to increase of 10-years overall survival, 70% versus 78,4% (р=0,04. The proposed version of conformal 3D CRT radiation therapy made ​​it possible compared to conventional 2D RT radiation therapy by increasing SOD radiation to the tumor, accuracy and compliance with the quality assurance of radiation therapy significantly reduce rates of recurrence and significantly increase the performance of 10-year overall and disease-free survival.

  6. Conformal Antennas, Research Program Review and Workshop Held at Crystal City, Arlington, Virginia, on 15-16 April 1975

    Science.gov (United States)

    1975-04-01

    Panel Members Professor Alexander Hessel , Polytechnic Institute of N.Y. Dr. W.H. Kummer. Hughes Aircraft Co. Mr. B. Sheleg, Naval Research Laboratory...Arrays, Studies and Experiment 25 A.T. Villeneuve, Hughes Aircraft Company Surface Ray Analysis of Conformal Arrays 51 A. Hessel , J. Shmoys...curvature on the radiation patterns of sources on cones. (Shmoys Sc Hessel , 1974) However, as presently applied, the geometric theory of diffrac- tion

  7. Drawing conformal diagrams for a fractal landscape

    Science.gov (United States)

    Winitzki, Sergei

    2005-06-01

    Generic models of cosmological inflation and the recently proposed scenarios of a recycling universe and the string theory landscape predict spacetimes whose global geometry is a stochastic, self-similar fractal. To visualize the complicated causal structure of such a universe, one usually draws a conformal (Carter-Penrose) diagram. I develop a new method for drawing conformal diagrams, applicable to arbitrary 1+1-dimensional spacetimes. This method is based on a qualitative analysis of intersecting lightrays and thus avoids the need for explicit transformations of the spacetime metric. To demonstrate the power and simplicity of this method, I present derivations of diagrams for spacetimes of varying complication. I then apply the lightray method to three different models of an eternally inflating universe (scalar-field inflation, recycling universe, and string theory landscape) involving the nucleation of nested asymptotically flat, de Sitter and/or anti-de Sitter bubbles. I show that the resulting diagrams contain a characteristic fractal arrangement of lines.

  8. Conformational transitions of a weak polyampholyte

    KAUST Repository

    Nair, Arun Kumar Narayanan

    2014-10-07

    Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.

  9. QCD-instantons and conformal inversion symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Klammer, D.

    2006-07-15

    Instantons are an essential and non-perturbative part of Quantum Chromodynamics, the theory of strong interactions. One of the most relevant quantities in the instanton calculus is the instanton-size distribution, which can be described on the one hand within the framework of instanton perturbation theory and on the other hand investigated numerically by means of lattice computations. A rapid onset of a drastic discrepancy between these respective results indicates that the underlying physics is not yet well understood. In this work we investigate the appealing possibility of a symmetry under conformal inversion of space-time leading to this deviation. The motivation being that the lattice data seem to be invariant under an inversion of the instanton size. Since the instanton solution of a given size turns into an anti-instanton solution having an inverted size under conformal inversion of space-time, we ask in a first investigation, whether this property is transferred to the quantum level. In order to introduce a new scale, which is indicated by the lattice data and corresponds to the average instanton size as inversion radius, we project the instanton calculus onto the four-dimensional surface of a five-dimensional sphere via stereographic projection. The radius of this sphere is associated with the average instanton size. The result for the instanton size-distribution projected onto the sphere agrees surprisingly well with the lattice data at qualitative level. The resulting symmetry under an inversion of the instanton size is almost perfect. (orig.)

  10. Hyperbolic theory of relativistic conformal dissipative fluids

    Science.gov (United States)

    Lehner, Luis; Reula, Oscar A.; Rubio, Marcelo E.

    2018-01-01

    We develop a complete description of the class of conformal relativistic dissipative fluids of divergence form, following the formalism described in [R. Geroch and L. Lindblom, Phys. Rev. D 41, 1855 (1990), 10.1103/PhysRevD.41.1855, S. Pennisi, Some considerations on a non linear approach to extended thermodynamics and in Proceedings of Symposium of Kinetic Theory and Extended Thermodynamics, Bologna, 1987.]. This type of theory is fully described in terms of evolution variables whose dynamics are governed by total divergence-type conservation laws. Specifically, we give a characterization of the whole family of conformal fluids in terms of a single master scalar function defined up to second-order corrections in dissipative effects, which we explicitly find in general form. This allows us to identify the equilibrium states of the theory and derive constitutive relations and a Fourier-like law for the corresponding first-order theory heat flux. Finally, we show that among this class of theories—and near equilibrium configurations—there exist symmetric hyperbolic ones, implying that for them one can define well-posed initial value problems.

  11. Twisted geometries, twistors and conformal transformations

    CERN Document Server

    Långvik, Miklos

    2016-01-01

    The twisted geometries of spin network states are described by simple twistors, isomorphic to null twistors with a time-like direction singled out. The isomorphism depends on the Immirzi parameter, and reduces to the identity when the parameter goes to infinity. Using this twistorial representation we study the action of the conformal group SU(2,2) on the classical phase space of loop quantum gravity, described by twisted geometry. The generators of translations and conformal boosts do not preserve the geometric structure, whereas the dilatation generator does. It corresponds to a 1-parameter family of embeddings of T*SL(2,C) in twistor space, and its action preserves the intrinsic geometry while changing the extrinsic one - that is the boosts among polyhedra. We discuss the implication of this action from a dynamical point of view, and compare it with a discretisation of the dilatation generator of the continuum phase space, given by the Lie derivative of the group character. At leading order in the continuu...

  12. Psychologists' social representations of conformity: Conformity – birth or death of individuality

    Directory of Open Access Journals (Sweden)

    Janez Bečaj

    2005-12-01

    Full Text Available When discussing conformity, modern social psychological literature draws its conclusions mostly from the classical sources written by the mid twentieth century authors such as Muzafer and CarolynSherif, Leon Festinger, Solomon Asch, Morton Deutsch, and Harold B. Gerard. A detailed scrutiny of these texts, however, reveals that many of today's widely accepted "findings" from that era are in fact not supported by the classical literature. Surprisingly, this analysis also shows that from the three metatheoretical orientations that coexisted at the time, namely the social-interactionistic, the interindividual, and the individualistic, only the latter survived to the present time, despite the fact that the authors pertaining to this orientation never really dealt with conformity, let alone defined it. Today, as a consequence, conformity is generally understood as a clash between the individual and society, although it is not at all clear which theoretical positions and empirical data could support such a view. It seems rather obvious that conformity will sooner or later have to be based on a new theoretical perspective and redefined.

  13. Conformation dependent monoclonal antibodies distinguish different replicating strains or conformers of prefibrillar Aβ oligomers

    Directory of Open Access Journals (Sweden)

    Yeung Stephen

    2010-12-01

    Full Text Available Abstract Background Age-related neurodegenerative diseases share a number of important pathological features, such as accumulation of misfolded proteins as amyloid oligomers and fibrils. Recent evidence suggests that soluble amyloid oligomers and not the insoluble amyloid fibrils may represent the primary pathological species of protein aggregates. Results We have produced several monoclonal antibodies that specifically recognize prefibrillar oligomers and do not recognize amyloid fibrils, monomer or natively folded proteins. Like the polyclonal antisera, the individual monoclonals recognize generic epitopes that do not depend on a specific linear amino acid sequence, but they display distinct preferences for different subsets of prefibrillar oligomers. Immunological analysis of a number of different prefibrillar Aβ oligomer preparations show that structural polymorphisms exist in Aβ prefibrillar oligomers that can be distinguished on the basis of their reactivity with monoclonal antibodies. Western blot analysis demonstrates that the conformers defined by the monoclonal antibodies have distinct size distributions, indicating that oligomer structure varies with size. The different conformational types of Aβ prefibrillar oligomers can serve as they serve as templates for monomer addition, indicating that they seed the conversion of Aβ monomer into more prefibrillar oligomers of the same type. Conclusions These results indicate that distinct structural variants or conformers of prefibrillar Aβ oligomers exist that are capable of seeding their own replication. These conformers may be analogous to different strains of prions.

  14. Tetrazole acetic acid: Tautomers, conformers, and isomerization

    Energy Technology Data Exchange (ETDEWEB)

    Araujo-Andrade, C. [Unidad Académica de Física de la Universidad Autónoma de Zacatecas, Zacatecas (Mexico); Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Reva, I., E-mail: reva@qui.uc.pt; Fausto, R. [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal)

    2014-02-14

    Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0–8 kJ mol{sup −1} energy range and should be appreciably populated at the sublimation temperature (∼330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol{sup −1}) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol{sup −1}). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm{sup −1}, where the first OH stretching overtone

  15. Selection for conformation and conformational homogeneity of litters in the German shepherd dog.

    Science.gov (United States)

    Stock, K F; Dammann, M; Distl, O

    2012-04-01

    Breeding standards of most dog breeds specify tolerable ranges of certain conformation traits. In the German shepherd dog (GSD), current means for withers height (WH) and BW are close to the upper breed limits. Therefore, strategies to avoid a further increase in size and to maximize the proportion of dogs fitting the breeding standard with respect to WH and BW should be compared. Body measurements were available for 14,416 male and 21,612 female GSD from 26,155 litters. Withers height and body mass index (BMI; i.e., BW/WH(2)) were considered direct selection traits. Using information on 17,154 GSD from litters with at least 2 dogs with conformation data, we defined within-litter variances of WH (vWH) and BMI (vBMI) as traits to select for the conformational homogeneity of litters. Officially recorded scores for canine hip dysplasia (CHD) of all dogs were used to monitor possible side effects of conformation selection on CHD. Genetic parameters were estimated multivariately in linear animal models by using Gibbs sampling. Heritabilities ranged between 0.19 and 0.34 for all traits, and additive genetic correlations between WH and vWH were -0.11 and those between BMI and vBMI were 0.11. The expected selection response was studied using the relative breeding values (RBV) of parents, assuming exclusion of sires, dams, or both with RBV larger than 120 and comparing means of WH, BMI, and CHD scores between offspring of all and selected parents. Concurrent selection for small WH and vWH was found to reduce the mean WH in males and females most efficiently while having little effect on CHD distributions. Multiple-trait selection for WH, vWH, BMI, and vBMI was hindered by the negative genetic correlations between the traits, and it tended to interfere with improvement of CHD status. Use of the RBV for WH and vWH for conformation selection is therefore recommended to maximize breeding success with regard to conformation and conformational homogeneity in the GSD.

  16. Conformal geodesics in spherically symmetric vacuum spacetimes with cosmological constant

    Science.gov (United States)

    García-Parrado Gómez-Lobo, A.; Gasperín, E.; Valiente Kroon, J. A.

    2018-02-01

    An analysis of conformal geodesics in the Schwarzschild–de Sitter and Schwarzschild–anti-de Sitter families of spacetimes is given. For both families of spacetimes we show that initial data on a spacelike hypersurface can be given such that the congruence of conformal geodesics arising from this data cover the whole maximal extension of canonical conformal representations of the spacetimes without forming caustic points. For the Schwarzschild–de Sitter family, the resulting congruence can be used to obtain global conformal Gaussian systems of coordinates of the conformal representation. In the case of the Schwarzschild–anti-de Sitter family, the natural parameter of the curves only covers a restricted time span so that these global conformal Gaussian systems do not exist.

  17. Conformable heat equation on a radial symmetric plate

    Directory of Open Access Journals (Sweden)

    Avci Derya

    2017-01-01

    Full Text Available The conformable heat equation is defined in terms of a local and limit-based definition called conformable derivative which provides some basic properties of integer order derivative such that conventional fractional derivatives lose some of them due to their non-local structures. In this paper, we aim to find the fundamental solution of a conformable heat equation acting on a radial symmetric plate. Moreover, we give a comparison between the new conformable and the existing Grunwald-Letnikov solutions of heat equation. The computational results show that conformable formulation is quite successful to show the sub-behaviors of heat process. In addition, conformable solution can be obtained by a analytical method without the need of a numerical scheme and any restrictions on the problem formulation. This is surely a significant advantageous compared to the Grunwald-Letnikov solution.

  18. A Projective-to-Conformal Fefferman-Type Construction

    Science.gov (United States)

    Hammerl, Matthias; Sagerschnig, Katja; Šilhan, Josef; Taghavi-Chabert, Arman; Zádník, Vojtĕch

    2017-10-01

    We study a Fefferman-type construction based on the inclusion of Lie groups SL(n+1) into Spin(n+1,n+1). The construction associates a split-signature (n,n)-conformal spin structure to a projective structure of dimension n. We prove the existence of a canonical pure twistor spinor and a light-like conformal Killing field on the constructed conformal space. We obtain a complete characterisation of the constructed conformal spaces in terms of these solutions to overdetermined equations and an integrability condition on the Weyl curvature. The Fefferman-type construction presented here can be understood as an alternative approach to study a conformal version of classical Patterson-Walker metrics as discussed in recent works by Dunajski-Tod and by the authors. The present work therefore gives a complete exposition of conformal Patterson-Walker metrics from the viewpoint of parabolic geometry.

  19. Social anxiety, stress type, and conformity among adolescents

    Directory of Open Access Journals (Sweden)

    Peng eZhang

    2016-05-01

    Full Text Available Social anxiety and stress type can influence strong conformity among adolescents; however, the interaction between them is not clear. In this study, 152 adolescents were recruited and assigned one of two conditions: an interaction and a judgment condition. In the interaction condition, adolescents with high social anxiety were less likely to conform when completing a modified Asch task, compared to adolescents who had low social anxiety. In the judgment condition, adolescents with high social anxiety were more likely to conform to the opinions from the unanimous majority. The results suggest that adolescents with high social anxiety may show different styles of strong conformity with the change of stress type. We believe that socially anxious adolescents avoid potential social situations with weaker conformity, while avoiding negative evaluations from others with stronger conformity. These findings contribute to a better understanding of the social dysfunctions among adolescents with high social anxiety and provide a new direction for clinical interventions.

  20. Social Anxiety, Stress Type, and Conformity among Adolescents.

    Science.gov (United States)

    Zhang, Peng; Deng, Yanhe; Yu, Xue; Zhao, Xin; Liu, Xiangping

    2016-01-01

    Social anxiety and stress type can influence strong conformity among adolescents; however, the interaction between them is not clear. In this study, 152 adolescents were recruited and assigned one of two conditions: an interaction and a judgment condition. In the interaction condition, adolescents with high social anxiety (HSA) were less likely to conform when completing a modified Asch task, compared to adolescents who had low social anxiety. In the judgment condition, adolescents with HSA were more likely to conform to the opinions from the unanimous majority. The results suggest that adolescents with HSA may show different styles of strong conformity with the change of stress type. We believe that socially anxious adolescents avoid potential social situations with weaker conformity, while avoiding negative evaluations from others with stronger conformity. These findings contribute to a better understanding of the social dysfunctions among adolescents with HSA and provide a new direction for clinical interventions.

  1. Nonperturbative results for two-index conformal windows

    DEFF Research Database (Denmark)

    Bergner, Georg; Ryttov, Thomas A.; Sannino, Francesco

    2015-01-01

    Via large and small $N_c$ relations we derive nonperturbative results about the conformal window of two-index theories. Using Schwinger-Dyson methods as well as four-loops results we estimate subleading corrections and show that naive large number of colors extrapolations are unreliable when $N......_c$ is less than about six. Nevertheless useful nonperturbative inequalities for the size of the conformal windows, for any number of colors, can be derived. By further observing that the adjoint conformal window is independent of the number of colors we argue, among other things, that: The large $N_c$ two......-index conformal window is twice the conformal window of the adjoint representation (which can be determined at small $N_c$) expressed in terms of Dirac fermions; Lattice results for adjoint matter can be used to provide independent information on the conformal dynamics of two-index theories such as SU...

  2. Space Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, William R.

    1968-01-01

    This booklet discusses three kinds of space radiation, cosmic rays, Van Allen Belts, and solar plasma. Cosmic rays are penetrating particles that we cannot see, hear or feel, which come from distant stars. Van Allen Belts, named after their discoverer are great belts of protons and electrons that the earth has captured in its magnetic trap. Solar plasma is a gaseous, electrically neutral mixture of positive and negative ions that the sun spews out from convulsed regions on its surface.

  3. Radiation Engineering for Designers

    Science.gov (United States)

    Pellish, Jonathan A.

    2015-01-01

    This tutorial provides an overview of the natural space radiation environment, an introduction to radiation effect types, an overview of EEE parts selection, scrubbing, and radiation mitigation, and an introduction to radiation testing.

  4. Risk Factors: Radiation

    Science.gov (United States)

    Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

  5. Acute Radiation Syndrome

    Science.gov (United States)

    ... Matters Information on Specific Types of Emergencies Acute Radiation Syndrome (ARS): A Fact Sheet for the Public ... is called the radiation dose. People exposed to radiation will get ARS only if: The radiation dose ...

  6. Chest radiation - discharge

    Science.gov (United States)

    Radiation - chest - discharge; Cancer - chest radiation; Lymphoma - chest radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after your first treatment: It may be hard ...

  7. Three dimensional conformal postoperative radiotherapy for ...

    African Journals Online (AJOL)

    Azza Helal

    2013-06-17

    Jun 17, 2013 ... the risk of oral mucositis, xerostomia, and hearing deficits on the irradiated side. Objectives: The aim of this study was to compare radiation doses received by target volume and different surrounding OARs using three different parotid irradiation techniques aiming to achieve the optimum technique which ...

  8. Double conformal space-time algebra

    Science.gov (United States)

    Easter, Robert Benjamin; Hitzer, Eckhard

    2017-01-01

    The Double Conformal Space-Time Algebra (DCSTA) is a high-dimensional 12D Geometric Algebra G 4,8that extends the concepts introduced with the Double Conformal / Darboux Cyclide Geometric Algebra (DCGA) G 8,2 with entities for Darboux cyclides (incl. parabolic and Dupin cyclides, general quadrics, and ring torus) in spacetime with a new boost operator. The base algebra in which spacetime geometry is modeled is the Space-Time Algebra (STA) G 1,3. Two Conformal Space-Time subalgebras (CSTA) G 2,4 provide spacetime entities for points, flats (incl. worldlines), and hyperbolics, and a complete set of versors for their spacetime transformations that includes rotation, translation, isotropic dilation, hyperbolic rotation (boost), planar reflection, and (pseudo)spherical inversion in rounds or hyperbolics. The DCSTA G 4,8 is a doubling product of two G 2,4 CSTA subalgebras that inherits doubled CSTA entities and versors from CSTA and adds new bivector entities for (pseudo)quadrics and Darboux (pseudo)cyclides in spacetime that are also transformed by the doubled versors. The "pseudo" surface entities are spacetime hyperbolics or other surface entities using the time axis as a pseudospatial dimension. The (pseudo)cyclides are the inversions of (pseudo)quadrics in rounds or hyperbolics. An operation for the directed non-uniform scaling (anisotropic dilation) of the bivector general quadric entities is defined using the boost operator and a spatial projection. DCSTA allows general quadric surfaces to be transformed in spacetime by the same complete set of doubled CSTA versor (i.e., DCSTA versor) operations that are also valid on the doubled CSTA point entity (i.e., DCSTA point) and the other doubled CSTA entities. The new DCSTA bivector entities are formed by extracting values from the DCSTA point entity using specifically defined inner product extraction operators. Quadric surface entities can be boosted into moving surfaces with constant velocities that display the length

  9. Study of polymer molecules and conformations with a nanopore

    Energy Technology Data Exchange (ETDEWEB)

    Golovchenko, Jene A.; Li, Jiali; Stein, Derek; Gershow, Marc H.

    2013-03-12

    The invention features methods for evaluating the conformation of a polymer, for example, for determining the conformational distribution of a plurality of polymers and to detect binding or denaturation events. The methods employ a nanopore which the polymer, e.g., a nucleic acid, traverses. As the polymer traverses the nanopore, measurements of transport properties of the nanopore yield data on the conformation of the polymer.

  10. Study of polymer molecules and conformations with a nanopore

    Energy Technology Data Exchange (ETDEWEB)

    Golovchenko, Jene A; Li, Jiali; Stein, Derek; Gershow, Marc H

    2015-03-03

    The invention features methods for evaluating the conformation of a polymer, for example, for determining the conformational distribution of a plurality of polymers and to detect binding or denaturation events. The methods employ a nanopore which the polymer, e.g., a nucleic acid, traverses. As the polymer traverses the nanopore, measurements of transport properties of the nanopore yield data on the conformation of the polymer.

  11. Flat connection, conformal field theory and quantum group

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Mitsuhiro.

    1989-07-01

    General framework of linear first order differential equation for four-point conformal block is studied by using flat connection. Integrability and SL{sub 2} invariance restrict possible form of flat connection. Under a special ansatz classical Yang-Baxter equation appears as an integrability condition and the WZW model turns to be unique conformal field theory in that case. Monodromy property of conformal block can be easily determined by the flat connection. 11 refs.

  12. Solid state conformational classification of eight-membered rings

    DEFF Research Database (Denmark)

    Pérez, J.; García, L.; Kessler, M.

    2005-01-01

    A statistical classification of the solid state conformation in the title complexes using data retrieved from the Cambridge Structural Database (CSD) has been made. Phosphate and phosphinate complexes show a chair conformation preferably. In phosphonate complexes, the most frequent conformations ...... are found to be boat–chair, chair and boat–boat; in all the boat–chair cases, the phosphorus atoms appear connected by a bridging carbon atom....

  13. Study of polymer molecules and conformations with a nanopore

    Science.gov (United States)

    Golovchenko, Jene A.; Li, Jiali; Stein, Derek; Gershow, Marc H.

    2010-12-07

    The invention features methods for evaluating the conformation of a polymer, for example, for determining the conformational distribution of a plurality of polymers and to detect binding or denaturation events. The methods employ a nanopore which the polymer, e.g., a nucleic acid, traverses. As the polymer traverses the nanopore, measurements of transport properties of the nanopore yield data on the conformation of the polymer.

  14. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Clayton B. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Thompson, Holly M. [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Benedict, Stanley H. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Seibert, J. Anthony [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Wong, Kenneth [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States); Vaughan, Andrew T. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Chen, Allen M., E-mail: allenmchen@yahoo.com [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States)

    2016-04-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning—a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of “gentle IGRT.”.

  15. Knowledge-Based Conformer Generation Using the Cambridge Structural Database.

    Science.gov (United States)

    Cole, Jason C; Korb, Oliver; McCabe, Patrick; Read, Murray; Taylor, Robin

    2018-02-09

    Fast generation of plausible molecular conformations is central to molecular modelling. This paper presents an approach to conformer generation that makes extensive use of the information available in the Cambridge Structural Database. By using geometric distributions derived from the Cambridge Structural Database, it is possible to create biologically relevant conformations in the majority of cases analysed. The paper compares the performance of the approach with previously published evaluations, and presents some cases where the method fails. The method appears to show significantly improved performance in reproduction of the conformations of structures observed in the Cambridge Structural Database and the Protein Data Bank as compared to other published methods of a similar speed.

  16. Discovering conformational sub-states relevant to protein function.

    Directory of Open Access Journals (Sweden)

    Arvind Ramanathan

    2011-01-01

    Full Text Available Internal motions enable proteins to explore a range of conformations, even in the vicinity of native state. The role of conformational fluctuations in the designated function of a protein is widely debated. Emerging evidence suggests that sub-groups within the range of conformations (or sub-states contain properties that may be functionally relevant. However, low populations in these sub-states and the transient nature of conformational transitions between these sub-states present significant challenges for their identification and characterization.To overcome these challenges we have developed a new computational technique, quasi-anharmonic analysis (QAA. QAA utilizes higher-order statistics of protein motions to identify sub-states in the conformational landscape. Further, the focus on anharmonicity allows identification of conformational fluctuations that enable transitions between sub-states. QAA applied to equilibrium simulations of human ubiquitin and T4 lysozyme reveals functionally relevant sub-states and protein motions involved in molecular recognition. In combination with a reaction pathway sampling method, QAA characterizes conformational sub-states associated with cis/trans peptidyl-prolyl isomerization catalyzed by the enzyme cyclophilin A. In these three proteins, QAA allows identification of conformational sub-states, with critical structural and dynamical features relevant to protein function.Overall, QAA provides a novel framework to intuitively understand the biophysical basis of conformational diversity and its relevance to protein function.

  17. Conformal Ultracapacitor Power Source Technology for the Miniature Kill Vehicle

    National Research Council Canada - National Science Library

    2004-01-01

    .... The conformal ultracapacitor power source will be attached to the inside available surface of the individual miniature kill vehicle, The ultracapacitor will be charged through a charging system...

  18. Peer influence: neural mechanisms underlying in-group conformity

    OpenAIRE

    Stallen, Mirre; Smidts, Ale; Sanfey, Alan G.

    2013-01-01

    People often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI). Participants completed a perceptual decision-making task while undergoing fMRI, during which they were exposed to the judgments of both in-group and out-group members. Our data suggest that conformity to the in-group is ...

  19. Invariants for minimal conformal supergravity in six dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Novak, Joseph; Theisen, Stefan [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Golm (Germany)

    2016-12-15

    We develop a new off-shell formulation for six-dimensional conformal supergravity obtained by gauging the 6D N=(1,0) superconformal algebra in superspace. This formulation is employed to construct two invariants for 6D N=(1,0) conformal supergravity, which contain C{sup 3} and C◻C terms at the component level. Using a conformal supercurrent analysis, we prove that these exhaust all such invariants in minimal conformal supergravity. Finally, we show how to construct the supersymmetric F◻F invariant in curved superspace.

  20. An Efficient Null Model for Conformational Fluctuations in Proteins

    DEFF Research Database (Denmark)

    Harder, Tim Philipp; Borg, Mikael; Bottaro, Sandro

    2012-01-01

    Protein dynamics play a crucial role in function, catalytic activity, and pathogenesis. Consequently, there is great interest in computational methods that probe the conformational fluctuations of a protein. However, molecular dynamics simulations are computationally costly and therefore are often...... limited to comparatively short timescales. TYPHON is a probabilistic method to explore the conformational space of proteins under the guidance of a sophisticated probabilistic model of local structure and a given set of restraints that represent nonlocal interactions, such as hydrogen bonds or disulfide...... on conformational fluctuations that is in correspondence with experimental measurements. TYPHON provides a flexible, yet computationally efficient, method to explore possible conformational fluctuations in proteins....