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Sample records for received prior craniospinal

  1. Lymphopenia caused by cranial irradiation in children receiving craniospinal radiotherapy

    International Nuclear Information System (INIS)

    Harisiadis, L.; Kopelson, G.; Chang, C.H.

    1977-01-01

    The peripheral blood changes were studied in 67 children who received craniospinal irradiation for posterior fossa tumors. At the completion of a cranial dose of about 3500 rad to the whole brain port, the lymphocytes were reduced to 858/mm 3 from 3084/mm 3 preoperatively. The counts of the remaining leukocytes stayed at a level somewhat higher than preoperatively; the eosinophils rose to 288/mm 3 from 125/mm 3 . With the initiation of the spinal field irradiation, which included a large proportion of the total bone marrow, the numbers of all the leukocytes decreased rapidly; the observed leukopenia was mainly secondary to neutropenia. A mechanism that was operating to restore the number of leukocytes became manifest immediately after the completion of radiotherapy, though the number of lymphocytes had not been totally restored to the preoperative level 6 years later. Irradiation of the lymphocytes that circulate through the vascular bed can explain the lymphopenia observed during cranial radiotherapy. Mild leukopenia observed in patients receiving radiotherapy through a relatively small port may be secondary to lymphopenia, and this does not necessarily indicate impaired bone marrow reserves

  2. The technique of craniospinal irradiation of paediatric patients in supine position

    International Nuclear Information System (INIS)

    Slampa, P.; Seneklova, Z.; Simicek, J.; Soumarova, R.; Burkon, P.; Burianova, L.

    2001-01-01

    Background. Postoperative radiation therapy has significant impact on local control and overall survival of paediatric patients with brain tumours but an irradiated volume is often a controversial issue. Our aim was to describe a new technique of craniospinal irradiation as a postoperative treatment in patients with the risk of relapse of brain tumours as well as to estimate the side effects of such craniospinal irradiation. Patients and methods. In the last 4 years, 17 paediatric patients under 15 years of age with medulloblastoma (8) ependymoma (6) and glioblastoma (3) received postoperative craniospinal axis radiotherapy by a new technique developed in our departments. This technique is based on irradiation in supine position with the use of asymmetric jaws of the linear accelerator. Results. Radiotherapy was well tolerated and dose-reduction was not needed in any case. Skin reactions were mild in all patients. The gastrointestinal and haematological toxicity was mild to moderate (WHO grade I-II). Conclusion. The proposed new technique of craniospinal irradiation is advantageous in terms of side effects and could be recommended to be widely used. Craniospinal irradiation in supine position is an alternative method to the treatment in prone position. The evaluation of the effectiveness was limited by a short follow-up interval. (author)

  3. Craniospinal radiotherapy in adult medulloblastoma

    International Nuclear Information System (INIS)

    Selek, U.; Zorlu, F.; Hurmuz, P.; Cengiz, M.; Gurkaynak, M.; Turker, A.; Soylemezoglu, F.

    2007-01-01

    Purpose: To evaluate the outcome and prognostic factors of adult patients with medulloblastoma. Patients and Methods: 26 adult medulloblastoma patients with a median age of 27 were subjected to craniospinal radiotherapy. A dose of 30.6 Gy with 1.8 Gy/fraction/day was prescribed to M0 patients, while 36 Gy were to be applied in patients with positive cerebrospinal liquor findings. The posterior fossa was boosted to 54 Gy. While 20 patients underwent external-beam radiotherapy alone, only six received sequential adjuvant chemotherapy. Results: Male/female ratio was 1.2. Preradiotherapy Karnofsky performance status was recorded as median 100%. 50% were classified as poor risk (n = 10, subtotal resection; n = 3, M+). The median follow-up time was 46.5 months. The 5-year actuarial survival rates for recurrence-free, distant metastasis-free, disease-free, and overall survival were 82.5%, 90.8%, 73.5%, and 89.7%, respectively. Patient characteristics, treatment factors and tumor characteristics failed to show any significance in univariate analysis. Grade 3 or 4 late morbidities were not observed. Conclusion: Yet, the current standard of care seems to remain craniospinal irradiation after maximal surgical resection of the primary neoplasm without clear indications for adjuvant chemotherapy. (orig.)

  4. Craniospinal Germinomas in Patient with Down Syndrome Successfully Treated with Standard-Dose Chemotherapy and Craniospinal Irradiation: Case Report and Literature Review.

    Science.gov (United States)

    Miyake, Yohei; Adachi, Jun-Ichi; Suzuki, Tomonari; Mishima, Kazuhiko; Sasaki, Atsushi; Nishikawa, Ryo

    2017-12-01

    Patients with Down syndrome (DS) are more likely to develop chemotherapy-related complications. The standard treatment for these patients with cancer has not yet been established, and the risks of standard chemotherapy are unclear. In this paper, a rare case of multiple craniospinal germinomas in a patient with DS, which was successfully treated with standard-dose chemotherapy combined with craniospinal irradiation, is reported. The authors report a case of multiple craniospinal germinomas in a DS patient who presented with bilateral oculomotor and facial nerve palsy and hearing loss. The patient underwent 3 courses of combination chemotherapy using a standard dose of carboplatin and etoposide and 23.4 Gy of concurrent craniospinal irradiation. Posttreatment magnetic resonance imaging showed reduction of the tumors. Both fluorodeoxyglucose- and methionine-positron emission tomography demonstrated no uptake in the residual tumors. Follow-up magnetic resonance imaging and positron emission tomography did not reveal tumor recurrence for 18 months. As far as we know, this is the first case of multiple craniospinal germinomas in a patient with DS who achieved a successful treatment result without fatal adverse events. The literature review indicated that disseminated germinomas may need intensive treatment to reduce recurrence risk. However, intensive chemotherapy using a combination of 3 or more anticancer drugs can increase the rate of treatment-related death during the early stage. Our case indicated that multiple craniospinal germinoma of DS patients could be treated with a standard dose of carboplatin and etoposide regimen with concurrent craniospinal irradiation along with appropriate supportive therapy and careful observation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Hypothyroidism in children with medulloblastoma: a comparison of 3600 and 2340 cGy craniospinal radiotherapy

    International Nuclear Information System (INIS)

    Paulino, Arnold C.

    2002-01-01

    Purpose: To determine if low-dose craniospinal irradiation (2340 cGy) with chemotherapy is associated with a lower incidence of hypothyroidism compared to standard dose (3600 cGy) with or without chemotherapy in children with medulloblastoma. Patients and Methods: Between 1980 and 1999, 32 patients ≤20 years old survived after craniospinal irradiation with or without chemotherapy. Twenty patients received 3600 cGy craniospinal irradiation (CSI), whereas 12 had 2340 cGy CSI; all patients received a posterior fossa boost to a total dose 5040-5580 cGy. The median ages at the time of CSI for those receiving 2340 cGy and 3600 cGy were 7.2 and 10.2 years, respectively. Chemotherapy (CT) was employed in 22 children. All children who received 2340 cGy had CT consisting of vincristine, CCNU, and either cisplatin or cyclophosphamide. Ten of 20 (50%) patients receiving 3600 cGy had CT; the most common regimen was vincristine, CCNU, and prednisone. Serum-free thyroxine and thyroid-stimulating hormone concentrations were measured in all children at variable times after radiotherapy. Thyroid-stimulating hormone responses to i.v. thyrotrophin-releasing hormone were assessed in those suspected of having central hypothyroidism. Median follow-up for children receiving 2340 cGy was 5 years (range: 2-11.2 years), whereas for those receiving 3600 cGy, follow-up was 12.5 years (range: 2.4-20 years). Results: Eighteen patients (56%) developed hypothyroidism at a median time after radiotherapy of 41 months (range: 10 months to 18 years). Primary hypothyroidism was more common than central hypothyroidism (38% and 19%). All 7 children 10 years had hypothyroidism (p<0.001). Hypothyroidism was documented in 10 of 12 (83%) who had 2340 cGy + CT, 6 of 10 (60%) who had 3600 cGy + CT, and 2 of 10 (20%) who had 3600 cGy without CT (p<0.025). Conclusions: Current treatment regimens consisting of chemotherapy and 2340 cGy craniospinal irradiation followed by a posterior fossa boost for

  6. [Anti-emetic effect of granisetron in patients undergoing cranial and craniospinal radiotherapy].

    Science.gov (United States)

    Yamasaki, Fumiyuki; Watanabe, Yosuke; Nosaka, Ryo; Kenjo, Masahiro; Nakamura, Kazuhiro; Takayasu, Takeshi; Saito, Taiichi; Tominaga, Atsushi; Sugiyama, Kazuhiko; Kurisu, Kaoru

    2014-01-01

    Approximately 30-59% of patients undergoing cranial or craniospinal radiotherapy experience nausea and/or vomiting. Here, we evaluated the effectiveness of granisetron for controlling emesis in patients treated with cranial or craniospinal radiotherapy. Between December 2011 and January 2013, 34 patients(19 males, 15 females;age range, 3-80 years)received cranial or craniospinal radiotherapy at our department. All but one male patient, who developed meningitis during the irradiation period were enrolled in this retrospective study. Patients who experienced irradiation-induced vomiting(grade 1)or nausea(grade 2)were treated with granisetron as a rescue anti-emetic. Episodes were graded as(1)no vomiting, no nausea, no anti-emetic;(2)no vomiting, nausea, no anti-emetic;(3)no vomiting, nausea with anti-emetic;and(4)vomiting. Of the 9 patients who underwent whole-brain or whole neural-axis irradiation, 5(55.6%)experienced grade 2 nausea or vomiting. Two of 6 patients(33.3%)treated with whole ventricle irradiation experienced grade 2 nausea or vomiting. Three of 18 patients(16.7%)who underwent local-field irradiation experienced grade 2 nausea or vomiting. Patients who underwent wide-field irradiation experienced nausea, vomiting, and anorexia(pgranisetron. Four of 9 patients(44.4%)treated with granisetron experienced constipation(grade 1 or 2);its administration had no major adverse effects in our study population. Rescue therapy with granisetron is safe and effective to treat nausea and vomiting in patients subjected to cranial or craniospinal irradiation.

  7. Anti-emetic effect of granisetron in patients undergoing cranial and craniospinal radiotherapy

    International Nuclear Information System (INIS)

    Yamasaki, Fumiyuki; Watanabe, Yosuke; Nosaka, Ryo

    2014-01-01

    Approximately 30-59% of patients undergoing cranial or craniospinal radiotherapy experience nausea and/or vomiting. Here, we evaluated the effectiveness of granisetron for controlling emesis in patients treated with cranial or craniospinal radiotherapy. Between December 2011 and January 2013, 34 patients (19 males, 15 females; age range, 3-80 years) received cranial or craniospinal radiotherapy at our department. All but one male patient, who developed meningitis during the irradiation period were enrolled in this retrospective study. Patients who experienced irradiation-induced vomiting (grade 1) or nausea (grade 2) were treated with granisetron as a rescue anti-emetic. Episodes were graded as no vomiting, no nausea, no anti-emetic; no vomiting, nausea, no anti-emetic; no vomiting, nausea with anti-emetic; and vomiting. Of the 9 patients who underwent whole-brain or whole neural-axis irradiation, 5 (55.6%) experienced grade 2 nausea or vomiting. Two of 6 patients (33.3%) treated with whole ventricle irradiation experienced grade 2 nausea or vomiting. Three of 18 patients (16.7%) who underwent local-field irradiation experienced grade 2 nausea or vomiting. Patients who underwent wide-field irradiation experienced nausea, vomiting, and anorexia (p<0.05). Complete response (no vomiting, no additional rescue anti-emetic, and no nausea) was observed in 5 of 9 patients treated with granisetron. Four of 9 patients (44.4%) treated with granisetron experienced constipation (grade 1 or 2); its administration had no major adverse effects in our study population. Rescue therapy with granisetron is safe and effective to treat nausea and vomiting in patients subjected to cranial or craniospinal irradiation. (author)

  8. A Simple Technique of Supine Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Munshi, Anusheel; Jalali, Rakesh

    2008-01-01

    We describe a simple procedure of craniospinal irradiation in supine position. The procedure was carried out with a 100-cm isocenter linear accelerator and compatible simulator. Treatment was with a 1 or 2 posteroanterior (PA)-directed spinal fields abutting lateral-directed cranial fields. Abutment of the fields was established by placement of markers on the neck of the patient, which provided a measure of the divergence of the spinal field. The precision and reproducibility of this technique, including the placement of junctions, appeared to be as good as for treatment in the prone position. The same could be verified with port films. We conclude that this new technique of supine craniospinal treatment is a simple and convenient alternative to traditional treatment in the prone position

  9. Standard and Nonstandard Craniospinal Radiotherapy Using Helical TomoTherapy

    International Nuclear Information System (INIS)

    Parker, William; Brodeur, Marylene; Roberge, David; Freeman, Carolyn

    2010-01-01

    Purpose: To show the advantages of planning and delivering craniospinal radiotherapy with helical TomoTherapy (TomoTherapy Inc., Madison, WI) by presenting 4 cases treated at our institution. Methods and Materials: We first present a standard case of craniospinal irradiation in a patient with recurrent myxopapillary ependymoma (MPE) and follow this with 2 cases requiring differential dosing to multiple target volumes. One of these, a patient with recurrent medulloblastoma, required a lower dose to be delivered to the posterior fossa because the patient had been previously irradiated to the full dose, and the other required concurrent boosts to leptomeningeal metastases as part of his treatment for newly diagnosed MPE. The final case presented is a patient with pronounced scoliosis who required spinal irradiation for recurrent MPE. Results: The four cases presented were planned and treated successfully with Helical Tomotherapy. Conclusions: Helical TomoTherapy delivers continuous arc-based intensity-modulated radiotherapy that gives high conformality and excellent dose homogeneity for the target volumes. Increased healthy tissue sparing is achieved at higher doses albeit at the expense of larger volumes of tissue receiving lower doses. Helical TomoTherapy allows for differential dosing of multiple targets, resulting in very elegant dose distributions. Daily megavoltage computed tomography imaging allows for precision of patient positioning, permitting a reduction in planning margins and increased healthy tissue sparing in comparison with standard techniques.

  10. Verification techniques and dose distribution for computed tomographic planned supine craniospinal radiation therapy

    International Nuclear Information System (INIS)

    Chang, Eric L.; Wong Peifong; Forster, Kenneth M.; Petru, Mark D.; Kowalski, Alexander V.; Maor, Moshe H.

    2003-01-01

    A modified 3-field technique was designed with opposed cranial fields and a single spinal field encompassing the entire spinal axis. Two methods of plan verifications were performed before the first treatment. First, a system of orthogonal rulers plus the thermoplastic head holder was used to visualize the light fields at the craniospinal junction. Second, film phantom measurements were taken to visualize the gap between the fields at the level of the spinal cord. Treatment verification entailed use of a posterior-anterior (PA) portal film and placement of radiopaque wire on the inferior border of the cranial field. More rigorous verification required a custom-fabricated orthogonal film holder. The isocenter positions of both fields when they matched were recorded using a record-and-verify system. A single extended distance spinal field collimated at 42 degree sign encompassed the entire spinal neuraxis. Data were collected from 40 fractions of craniospinal irradiation (CSI). The systematic error observed for the actual daily treatments was -0.5 mm (underlap), while the stochastic error was represented by a standard deviation of 5.39 mm. Measured data across the gapped craniospinal junction with junction shifts included revealed a dose ranging from 89.3% to 108%. CSI can be performed without direct visualization of the craniospinal junction by using the verification methods described. While the use of rigorous film verification for supine technique may have reduced the systematic error, the inability to visualize the supine craniospinal junction on skin appears to have increased the stochastic error compared to published data on such errors associated with prone craniospinal irradiation

  11. Large intradural craniospinal arachnoid cyst: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Souvagya Panigrahi

    2012-01-01

    Full Text Available Presence of an arachnoid cyst at craniospinal junction is not very common. This is a very rare anatomic site, with only seven other cases reported in the literature. We report a case of large intradural craniospinal arachnoid cyst presenting with obstructive hydrocephalus and cranial nerve palsy. A 39-year-old male presented with 8-month history of neck pain, headache, vomiting, visual disturbances, diminished taste sensation, and numbness of face. He had bilateral papilledema on ophthalmoscopy. Magnetic resonance imaging (MRI revealed a posterior fossa arachnoid cyst extending down to the lower border of C5 vertebra. Posterior decompression was done through C5 laminectomy. He made a full recovery and was asymptomatic at 6-month follow-up examination. The clinical features, diagnosis, and management of these rare craniospinal arachnoid cysts are discussed.

  12. Supine proton beam craniospinal radiotherapy using a novel tabletop adapter

    International Nuclear Information System (INIS)

    Buchsbaum, Jeffrey C.; Besemer, Abby; Simmons, Joseph; Hoene, Ted; Simoneaux, Victor; Sandefur, Amy; Wolanski, Mark; Li, Zhao; Cheng, Chee-Wei

    2013-01-01

    To develop a device that allows supine craniospinal proton and photon therapy to the vast majority of proton and photon facilities currently experiencing limitations as a result of couch design issues. Plywood and carbon fiber were used for the development of a prototype unit. Once this was found to be satisfactory after all design issues were addressed, computer-assisted design (CAD) was used and carbon fiber tables were built to our specifications at a local manufacturer of military and racing car carbon fiber parts. Clinic-driven design was done using real-time team discussion for a prototype design. A local machinist was able to construct a prototype unit for us in <2 weeks after the start of our project. Once the prototype had been used successfully for several months and all development issues were addressed, a custom carbon fiber design was developed in coordination with a carbon fiber manufacturer in partnership. CAD methods were used to design the units to allow oblique fields from head to thigh on patients up to 200 cm in height. Two custom-designed carbon fiber craniospinal tabletop designs now exist: one long and one short. Four are in successful use in our facility. Their weight tolerance is greater than that of our robot table joint (164 kg). The long unit allows for working with taller patients and can be converted into a short unit as needed. An affordable, practical means of doing supine craniospinal therapy with protons or photons can be used in most locations via the use of these devices. This is important because proton therapy provides a much lower integral dose than all other therapy methods for these patients and the supine position is easier for patients to tolerate and for anesthesia delivery. These units have been successfully used for adult and pediatric supine craniospinal therapy, proton therapy using oblique beams to the low pelvis, treatment of various spine tumors, and breast-sparing Hodgkin's therapy

  13. Supine proton beam craniospinal radiotherapy using a novel tabletop adapter

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, Jeffrey C., E-mail: jbuchsba@iupui.edu [IU Health Proton Therapy Center, Bloomington, IN (United States); Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN (United States); Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN (United States); Besemer, Abby; Simmons, Joseph; Hoene, Ted; Simoneaux, Victor; Sandefur, Amy [IU Health Proton Therapy Center, Bloomington, IN (United States); Wolanski, Mark; Li, Zhao; Cheng, Chee-Wei [IU Health Proton Therapy Center, Bloomington, IN (United States); Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States)

    2013-04-01

    To develop a device that allows supine craniospinal proton and photon therapy to the vast majority of proton and photon facilities currently experiencing limitations as a result of couch design issues. Plywood and carbon fiber were used for the development of a prototype unit. Once this was found to be satisfactory after all design issues were addressed, computer-assisted design (CAD) was used and carbon fiber tables were built to our specifications at a local manufacturer of military and racing car carbon fiber parts. Clinic-driven design was done using real-time team discussion for a prototype design. A local machinist was able to construct a prototype unit for us in <2 weeks after the start of our project. Once the prototype had been used successfully for several months and all development issues were addressed, a custom carbon fiber design was developed in coordination with a carbon fiber manufacturer in partnership. CAD methods were used to design the units to allow oblique fields from head to thigh on patients up to 200 cm in height. Two custom-designed carbon fiber craniospinal tabletop designs now exist: one long and one short. Four are in successful use in our facility. Their weight tolerance is greater than that of our robot table joint (164 kg). The long unit allows for working with taller patients and can be converted into a short unit as needed. An affordable, practical means of doing supine craniospinal therapy with protons or photons can be used in most locations via the use of these devices. This is important because proton therapy provides a much lower integral dose than all other therapy methods for these patients and the supine position is easier for patients to tolerate and for anesthesia delivery. These units have been successfully used for adult and pediatric supine craniospinal therapy, proton therapy using oblique beams to the low pelvis, treatment of various spine tumors, and breast-sparing Hodgkin's therapy.

  14. Phase I study of temozolomide in paediatric patients with advanced cancer. United Kingdom Children's Cancer Study Group.

    Science.gov (United States)

    Estlin, E. J.; Lashford, L.; Ablett, S.; Price, L.; Gowing, R.; Gholkar, A.; Kohler, J.; Lewis, I. J.; Morland, B.; Pinkerton, C. R.; Stevens, M. C.; Mott, M.; Stevens, R.; Newell, D. R.; Walker, D.; Dicks-Mireaux, C.; McDowell, H.; Reidenberg, P.; Statkevich, P.; Marco, A.; Batra, V.; Dugan, M.; Pearson, A. D.

    1998-01-01

    A phase I study of temozolomide administered orally once a day, on 5 consecutive days, between 500 and 1200 mg m(-2) per 28-day cycle was performed. Children were stratified according to prior craniospinal irradiation or nitrosourea therapy. Sixteen of 20 patients who had not received prior craniospinal irradiation or nitrosourea therapy were evaluable. Myelosuppression was dose limiting, with Common Toxicity Criteria (CTC) grade 4 thrombocytopenia occurring in one of six patients receiving 1000 mg m(-2) per cycle, and two of four patients treated at 1200 mg m(-2) per cycle. Therefore, the maximum-tolerated dose (MTD) was 1000 mg m(-2) per cycle. The MTD was not defined for children with prior craniospinal irradiation because of poor recruitment. Plasma pharmacokinetic analyses showed temozolomide to be rapidly absorbed and eliminated, with linear increases in peak plasma concentrations and systemic exposure with increasing dose. Responses (CR and PR) were seen in two out of five patients with high-grade astrocytomas, and one patient had stable disease. One of ten patients with diffuse intrinsic brain stem glioma achieved a long-term partial response, and a further two patients had stable disease. Therefore, the dose recommended for phase II studies in patients who have not received prior craniospinal irradiation or nitrosoureas is 1000 mg m(-2) per cycle. Further evaluation in diffuse intrinsic brain stem gliomas and other high-grade astrocytomas is warranted. Images Figure 5 p658-b Figure 6 p659-b PMID:9744506

  15. Craniospinal Irradiation for Trilateral Retinoblastoma Following Ocular Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Lawrence B.; Bentel, Gunilla; Sherouse, George W.; Spencer, David P.; Light, Kim

    2015-01-15

    A case study is presented. Craniospinal radiotherapy and a three-field pineal boost for trilateral retinoblastoma were delivered to a patient previously irradiated for ocular retinoblastoma. The availability of CT-based three-dimensional treatment planning provided the capability of identifying the previously irradiated volume as a three-dimensional anatomic structure and of designing a highly customized set of treatment beams that minimized reirradiation of that volume.

  16. Inter-Institutional Comparison of Personalized Risk Assessments for Second Malignant Neoplasms for a 13-Year-Old Girl Receiving Proton versus Photon Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Taddei, Phillip J., E-mail: pt06@aub.edu.lb [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Unit 1202, 1515 Holcombe Blvd, Houston, TX 77030 (United States); The University of Texas Graduate School of Biomedical Sciences at Houston, P.O. Box 20334, Houston, TX 77225 (United States); Department of Radiation Oncology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020 (Lebanon); Khater, Nabil [Department of Radiation Oncology, Hôtel-Dieu de France Hospital, University of St. Joseph, P.O. Box 166830, Alfred Naccache Blvd, Beirut (Lebanon); Zhang, Rui [Medical Physics Program, Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Dr., Baton Rouge, LA 70803 (United States); Department of Physics, Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA 70809 (United States); Geara, Fady B. [Department of Radiation Oncology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020 (Lebanon); Mahajan, Anita [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Unit 1202, 1515 Holcombe Blvd, Houston, TX 77030 (United States); The University of Texas Graduate School of Biomedical Sciences at Houston, P.O. Box 20334, Houston, TX 77225 (United States); Jalbout, Wassim [Department of Radiation Oncology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020 (Lebanon); Pérez-Andújar, Angélica [Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Unit 1202, 1515 Holcombe Blvd, Houston, TX 77030 (United States); Youssef, Bassem [Department of Radiation Oncology, American University of Beirut Medical Center, P.O. Box 11-0236, Riad El Solh, Beirut 1107 2020 (Lebanon); Newhauser, Wayne D. [Medical Physics Program, Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Dr., Baton Rouge, LA 70803 (United States); Department of Physics, Mary Bird Perkins Cancer Center, 4950 Essen Lane, Baton Rouge, LA 70809 (United States)

    2015-03-10

    Children receiving radiotherapy face the probability of a subsequent malignant neoplasm (SMN). In some cases, the predicted SMN risk can be reduced by proton therapy. The purpose of this study was to apply the most comprehensive dose assessment methods to estimate the reduction in SMN risk after proton therapy vs. photon therapy for a 13-year-old girl requiring craniospinal irradiation (CSI). We reconstructed the equivalent dose throughout the patient’s body from therapeutic and stray radiation and applied SMN incidence and mortality risk models for each modality. Excluding skin cancer, the risk of incidence after proton CSI was a third of that of photon CSI. The predicted absolute SMN risks were high. For photon CSI, the SMN incidence rates greater than 10% were for thyroid, non-melanoma skin, lung, colon, stomach, and other solid cancers, and for proton CSI they were non-melanoma skin, lung, and other solid cancers. In each setting, lung cancer accounted for half the risk of mortality. In conclusion, the predicted SMN risk for a 13-year-old girl undergoing proton CSI was reduced vs. photon CSI. This study demonstrates the feasibility of inter-institutional whole-body dose and risk assessments and also serves as a model for including risk estimation in personalized cancer care.

  17. Inter-Institutional Comparison of Personalized Risk Assessments for Second Malignant Neoplasms for a 13-Year-Old Girl Receiving Proton versus Photon Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Taddei, Phillip J.; Khater, Nabil; Zhang, Rui; Geara, Fady B.; Mahajan, Anita; Jalbout, Wassim; Pérez-Andújar, Angélica; Youssef, Bassem; Newhauser, Wayne D.

    2015-01-01

    Children receiving radiotherapy face the probability of a subsequent malignant neoplasm (SMN). In some cases, the predicted SMN risk can be reduced by proton therapy. The purpose of this study was to apply the most comprehensive dose assessment methods to estimate the reduction in SMN risk after proton therapy vs. photon therapy for a 13-year-old girl requiring craniospinal irradiation (CSI). We reconstructed the equivalent dose throughout the patient’s body from therapeutic and stray radiation and applied SMN incidence and mortality risk models for each modality. Excluding skin cancer, the risk of incidence after proton CSI was a third of that of photon CSI. The predicted absolute SMN risks were high. For photon CSI, the SMN incidence rates greater than 10% were for thyroid, non-melanoma skin, lung, colon, stomach, and other solid cancers, and for proton CSI they were non-melanoma skin, lung, and other solid cancers. In each setting, lung cancer accounted for half the risk of mortality. In conclusion, the predicted SMN risk for a 13-year-old girl undergoing proton CSI was reduced vs. photon CSI. This study demonstrates the feasibility of inter-institutional whole-body dose and risk assessments and also serves as a model for including risk estimation in personalized cancer care

  18. Predicted risks of second malignant neoplasm incidence and mortality due to secondary neutrons in a girl and boy receiving proton craniospinal irradiation

    International Nuclear Information System (INIS)

    Taddei, Phillip J; Mirkovic, Dragan; Zhang Rui; Giebeler, Annelise; Harvey, Mark; Newhauser, Wayne D; Mahajan, Anita; Kornguth, David; Woo, Shiao

    2010-01-01

    The purpose of this study was to compare the predicted risks of second malignant neoplasm (SMN) incidence and mortality from secondary neutrons for a 9-year-old girl and a 10-year-old boy who received proton craniospinal irradiation (CSI). SMN incidence and mortality from neutrons were predicted from equivalent doses to radiosensitive organs for cranial, spinal and intracranial boost fields. Therapeutic proton absorbed dose and equivalent dose from neutrons were calculated using Monte Carlo simulations. Risks of SMN incidence and mortality in most organs and tissues were predicted by applying risks models from the National Research Council of the National Academies to the equivalent dose from neutrons; for non-melanoma skin cancer, risk models from the International Commission on Radiological Protection were applied. The lifetime absolute risks of SMN incidence due to neutrons were 14.8% and 8.5%, for the girl and boy, respectively. The risks of a fatal SMN were 5.3% and 3.4% for the girl and boy, respectively. The girl had a greater risk for any SMN except colon and liver cancers, indicating that the girl's higher risks were not attributable solely to greater susceptibility to breast cancer. Lung cancer predominated the risk of SMN mortality for both patients. This study suggests that the risks of SMN incidence and mortality from neutrons may be greater for girls than for boys treated with proton CSI.

  19. Technique for sparing previously irradiated critical normal structures in salvage proton craniospinal irradiation

    International Nuclear Information System (INIS)

    McDonald, Mark W; Wolanski, Mark R; Simmons, Joseph W; Buchsbaum, Jeffrey C

    2013-01-01

    Cranial reirradiation is clinically appropriate in some cases but cumulative radiation dose to critical normal structures remains a practical concern. The authors developed a simple technique in 3D conformal proton craniospinal irradiation (CSI) to block organs at risk (OAR) while minimizing underdosing of adjacent target brain tissue. Two clinical cases illustrate the use of proton therapy to provide salvage CSI when a previously irradiated OAR required sparing from additional radiation dose. The prior radiation plan was coregistered to the treatment planning CT to create a planning organ at risk volume (PRV) around the OAR. Right and left lateral cranial whole brain proton apertures were created with a small block over the PRV. Then right and left lateral “inverse apertures” were generated, creating an aperture opening in the shape of the area previously blocked and blocking the area previously open. The inverse aperture opening was made one millimeter smaller than the original block to minimize the risk of dose overlap. The inverse apertures were used to irradiate the target volume lateral to the PRV, selecting a proton beam range to abut the 50% isodose line against either lateral edge of the PRV. Together, the 4 cranial proton fields created a region of complete dose avoidance around the OAR. Comparative photon treatment plans were generated with opposed lateral X-ray fields with custom blocks and coplanar intensity modulated radiation therapy optimized to avoid the PRV. Cumulative dose volume histograms were evaluated. Treatment plans were developed and successfully implemented to provide sparing of previously irradiated critical normal structures while treating target brain lateral to these structures. The absence of dose overlapping during irradiation through the inverse apertures was confirmed by film. Compared to the lateral X-ray and IMRT treatment plans, the proton CSI technique improved coverage of target brain tissue while providing the least

  20. SU-F-T-515: Increased Skin Dose in Supine Craniospinal Irradiation Due to Carbon Fiber Couch and Vacuum Bag Immobilization Device

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, D; Zhao, Z; Wang, X; Yang, J [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To measure the surface dose for supine craniospinal irradiation employing posterior beams, treating through an imaging couch and BlueBag immobilization device. Methods: The percentage depth dose (PDD) in the buildup region of a clinical 6 MV photon beam was measured using an Advanced Markus parallel plate ionization chamber in a solid water phantom. The PDD from a 10×10 cm{sup 2} anterior beam was measured at 100 cm SSD, simulating a traditional prone craniospinal technique. The measurements were compared to commissioning and treatment planning system data. The PDD was also measured in a posterior setup with the phantom surface laying directly on the Brainlab carbon fiber imaging couch, with the phantom surface 100 cm from the source, simulating a supine craniospinal setup. The posterior measurements were repeated with a BlueBag vacuum immobilization device between the couch and phantom, with thicknesses of 1.7 cm and 5 cm. The PDD from a 10×10 cm{sup 2} field and a typical 6×30 cm{sup 2} craniospinal field were also compared. The PDDs were normalized at 5 cm to reflect typical craniospinal prescription dose normalization. Results: The measured PDD curve from the anterior setup agreed well with commissioning and treatment planning data, with surface doses of 19.9%, 28.8% and 27.7%, respectively. The surface doses of the 10×10 cm{sup 2} and 6×30 cm{sup 2} fields delivered through the imaging couch were both 122.4%. The supine setup yielded surface doses of 122.4%, 121.6%, and 119.6% for the couch only, 1.7 cm bag, and 5 cm bag setups, respectively. Conclusion: Delivering craniospinal irradiation through a carbon fiber couch removes the majority of skin sparing. The addition of a vacuum bag immobilization device restores some skin sparing, but the magnitude of this effect is negligible.

  1. Comprehensive Craniospinal Radiation for Controlling Central Nervous System Leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Gary V.; Shihadeh, Ferial [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kantarjian, Hagop [Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rondon, Gabriela; Kebriaei, Partow [Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); O' Brien, Susan [Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kedir, Aziza; Said, Mustefa; Grant, Jonathan D. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Thomas, Deborah A. [Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gidley, Paul W. [Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Arzu, Isidora; Pinnix, Chelsea; Reed, Valerie [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dabaja, Bouthaina S., E-mail: bdabaja@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-12-01

    Purpose: To determine the benefit of radiation therapy (RT) in resolution of neurologic symptoms and deficits and whether the type of RT fields influences central nervous system (CNS) control in adults with CNS leukemia. Methods and Materials: A total of 163 adults from 1996 to 2012 were retrospectively analyzed. Potential associations between use of radiation and outcome were investigated by univariate and multivariate analysis. Results: The median survival time was 3.8 months after RT. Common presenting symptoms were headache in 79 patients (49%), cranial nerve VII deficit in 46 (28%), and cranial nerve II deficit in 44 (27%). RT was delivered to the base of skull in 48 patients (29%), to the whole brain (WB) in 67 (41%), and to the craniospinal axis (CS) in 48 (29%). Among 149 patients with a total of 233 deficits, resolution was observed in 34 deficits (15%), improvement in 126 deficits (54%), stability in 34 deficits (15%), and progression in 39 deficits (17%). The 12-month CNS progression-free survival was 77% among those receiving CS/WB and 51% among those receiving base of skull RT (P=.02). On multivariate analysis, patients who did not undergo stem cell transplantation after RT and base of skull RT were associated with worse CNS progression-free survival. Conclusions: Improvement or resolution of symptoms occurred in two thirds of deficits after RT. Comprehensive radiation to the WB or CS seems to offer a better outcome, especially in isolated CNS involvement.

  2. Comprehensive Craniospinal Radiation for Controlling Central Nervous System Leukemia

    International Nuclear Information System (INIS)

    Walker, Gary V.; Shihadeh, Ferial; Kantarjian, Hagop; Allen, Pamela; Rondon, Gabriela; Kebriaei, Partow; O'Brien, Susan; Kedir, Aziza; Said, Mustefa; Grant, Jonathan D.; Thomas, Deborah A.; Gidley, Paul W.; Arzu, Isidora; Pinnix, Chelsea; Reed, Valerie; Dabaja, Bouthaina S.

    2014-01-01

    Purpose: To determine the benefit of radiation therapy (RT) in resolution of neurologic symptoms and deficits and whether the type of RT fields influences central nervous system (CNS) control in adults with CNS leukemia. Methods and Materials: A total of 163 adults from 1996 to 2012 were retrospectively analyzed. Potential associations between use of radiation and outcome were investigated by univariate and multivariate analysis. Results: The median survival time was 3.8 months after RT. Common presenting symptoms were headache in 79 patients (49%), cranial nerve VII deficit in 46 (28%), and cranial nerve II deficit in 44 (27%). RT was delivered to the base of skull in 48 patients (29%), to the whole brain (WB) in 67 (41%), and to the craniospinal axis (CS) in 48 (29%). Among 149 patients with a total of 233 deficits, resolution was observed in 34 deficits (15%), improvement in 126 deficits (54%), stability in 34 deficits (15%), and progression in 39 deficits (17%). The 12-month CNS progression-free survival was 77% among those receiving CS/WB and 51% among those receiving base of skull RT (P=.02). On multivariate analysis, patients who did not undergo stem cell transplantation after RT and base of skull RT were associated with worse CNS progression-free survival. Conclusions: Improvement or resolution of symptoms occurred in two thirds of deficits after RT. Comprehensive radiation to the WB or CS seems to offer a better outcome, especially in isolated CNS involvement

  3. Acute toxicity profile of craniospinal irradiation with intensity-modulated radiation therapy in children with medulloblastoma: A prospective analysis

    International Nuclear Information System (INIS)

    Cox, Maurice C.; Kusters, Johannes M.; Gidding, Corrie E.; Schieving, Jolanda H.; Lindert, Erik J. van; Kaanders, Johannes H.; Janssens, Geert O.

    2015-01-01

    To report on the acute toxicity in children with medulloblastoma undergoing intensity-modulated radiation therapy (IMRT) with daily intrafractionally modulated junctions. Newly diagnosed patients, aged 3–21, with standard-risk (SR) or high-risk (HR) medulloblastoma were eligible. A dose of 23.4 or 36.0Gy in daily fractions of 1.8Gy was prescribed to the craniospinal axis, followed by a boost to the primary tumor bed (54 or 55.8Gy) and metastases (39.6–55.8Gy), when indicated. Weekly, an intravenous bolus of vincristine was combined for patients with SR medulloblastoma and patients participating in the COG-ACNS-0332 study. Common toxicity criteria (CTC, version 2.0) focusing on skin, alopecia, voice changes, conjunctivitis, anorexia, dysphagia, gastro-intestinal symptoms, headache, fatigue and hematological changes were scored weekly during radiotherapy. From 2010 to 2014, data from 15 consecutive patients (SR, n = 7; HR, n = 8) were collected. Within 72 h from onset of treatment, vomiting (66 %) and headache (46 %) occurred. During week 3 of treatment, a peak incidence in constipation (33 %) and abdominal pain/cramping (40 %) was observed, but only in the subgroup of patients (n = 9) receiving vincristine (constipation: 56 vs 0 %, P = .04; pain/cramping: 67 vs 0 %, P = .03). At week 6, 73 % of the patients developed faint erythema of the cranial skin with dry desquamation (40 %) or moist desquamation confined to the skin folds of the auricle (33 %). No reaction of the skin overlying the spinal target volume was observed. Headache at onset and gastro-intestinal toxicity, especially in patients receiving weekly vincristine, were the major complaints of patients with medulloblastoma undergoing craniospinal irradiation with IMRT

  4. Disparities in Diagnoses Received Prior to a Diagnosis of Autism Spectrum Disorder

    Science.gov (United States)

    Mandell, David S.; Ittenbach, Richard F.; Levy, Susan E.; Pinto-Martin, Jennifer A.

    2007-01-01

    This study estimated differences by ethnicity in the diagnoses assigned prior to the diagnosis of autism. In this sample of 406 Medicaid-eligible children, African-Americans were 2.6 times less likely than white children to receive an autism diagnosis on their first specialty care visit. Among children who did not receive an autism diagnosis on…

  5. Critical combinations of radiation dose and volume predict intelligence quotient and academic achievement scores after craniospinal irradiation in children with medulloblastoma.

    Science.gov (United States)

    Merchant, Thomas E; Schreiber, Jane E; Wu, Shengjie; Lukose, Renin; Xiong, Xiaoping; Gajjar, Amar

    2014-11-01

    To prospectively follow children treated with craniospinal irradiation to determine critical combinations of radiation dose and volume that would predict for cognitive effects. Between 1996 and 2003, 58 patients (median age 8.14 years, range 3.99-20.11 years) with medulloblastoma received risk-adapted craniospinal irradiation followed by dose-intense chemotherapy and were followed longitudinally with multiple cognitive evaluations (through 5 years after treatment) that included intelligence quotient (estimated intelligence quotient, full-scale, verbal, and performance) and academic achievement (math, reading, spelling) tests. Craniospinal irradiation consisted of 23.4 Gy for average-risk patients (nonmetastatic) and 36-39.6 Gy for high-risk patients (metastatic or residual disease >1.5 cm(2)). The primary site was treated using conformal or intensity modulated radiation therapy using a 2-cm clinical target volume margin. The effect of clinical variables and radiation dose to different brain volumes were modeled to estimate cognitive scores after treatment. A decline with time for all test scores was observed for the entire cohort. Sex, race, and cerebrospinal fluid shunt status had a significant impact on baseline scores. Age and mean radiation dose to specific brain volumes, including the temporal lobes and hippocampi, had a significant impact on longitudinal scores. Dichotomized dose distributions at 25 Gy, 35 Gy, 45 Gy, and 55 Gy were modeled to show the impact of the high-dose volume on longitudinal test scores. The 50% risk of a below-normal cognitive test score was calculated according to mean dose and dose intervals between 25 Gy and 55 Gy at 10-Gy increments according to brain volume and age. The ability to predict cognitive outcomes in children with medulloblastoma using dose-effects models for different brain subvolumes will improve treatment planning, guide intervention, and help estimate the value of newer methods of irradiation. Copyright © 2014

  6. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    International Nuclear Information System (INIS)

    Schoenfeld, Gordon O.; Amdur, Robert J.; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-01-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element

  7. Postoperative craniospinal radiotherapy of medulloblastoma in children and young adults

    Directory of Open Access Journals (Sweden)

    Golubičić Ivana V.

    2003-01-01

    Full Text Available PURPOSE The aim of this study was: 1. to evaluate treatment results of combined therapy (surgery, postoperative craniospinal radiotherapy with or without chemotherapy and 2. to assess factors affecting prognosis (extend of tumor removal, involvement of the brain stem, extent of disease postoperative meningitis, shunt placement, age, sex and time interval from surgery to start of postoperative radiotherapy. PATIENTS AND METHODS During the period 1986-1996, 78 patients with medulloblastoma, aged 1-22 years (median 8.6 years, were treated with combined modality therapy and 72 of them were evaluable for the study end-points. Entry criteria were histologically proven diagnosis, age under 22 years, and no history of previous malignant disease. The main characteristics of the group are shown in Table 1. Twenty-nine patients (37.2% have total, 8 (10.3% near total and 41 (52.5% partial removal. Seventy-two of 78 patients were treated with curative intent and received postoperative craniospinal irradiation. Radiotherapy started 13-285 days after surgery (median 36 days. Only 13 patients started radiotherapy after 60 days following surgery. Adjuvant chemotherapy was applied in 63 (80.7% patients. The majority of them (46 73% received chemotherapy with CCNU and Vincristine. The survival rates were calculated with the Kaplan-Meier method and the differences in survival were analyzed using the Wilcoxon test and log-rank test. RESULTS The follow-up period ranged from 1-12 years (median 3 years. Five-year overall survival (OS was 51% and disease-free survival (DFS 47% (Graph 1. During follow-up 32 relapses occurred. Patients having no brain stem infiltration had significantly better survival (p=0.0023 (Graph 2. Patients with positive myelographic findings had significantly poorer survival compared to dose with negative myelographic findings (p=0.0116. Significantly poorer survival was found in patients with meningitis developing in the postoperative period

  8. Critical Combinations of Radiation Dose and Volume Predict Intelligence Quotient and Academic Achievement Scores After Craniospinal Irradiation in Children With Medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Schreiber, Jane E. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu, Shengjie [Department of Biostatistcs, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Lukose, Renin [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Xiong, Xiaoping [Department of Biostatistcs, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Gajjar, Amar [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2014-11-01

    Purpose: To prospectively follow children treated with craniospinal irradiation to determine critical combinations of radiation dose and volume that would predict for cognitive effects. Methods and Materials: Between 1996 and 2003, 58 patients (median age 8.14 years, range 3.99-20.11 years) with medulloblastoma received risk-adapted craniospinal irradiation followed by dose-intense chemotherapy and were followed longitudinally with multiple cognitive evaluations (through 5 years after treatment) that included intelligence quotient (estimated intelligence quotient, full-scale, verbal, and performance) and academic achievement (math, reading, spelling) tests. Craniospinal irradiation consisted of 23.4 Gy for average-risk patients (nonmetastatic) and 36-39.6 Gy for high-risk patients (metastatic or residual disease >1.5 cm{sup 2}). The primary site was treated using conformal or intensity modulated radiation therapy using a 2-cm clinical target volume margin. The effect of clinical variables and radiation dose to different brain volumes were modeled to estimate cognitive scores after treatment. Results: A decline with time for all test scores was observed for the entire cohort. Sex, race, and cerebrospinal fluid shunt status had a significant impact on baseline scores. Age and mean radiation dose to specific brain volumes, including the temporal lobes and hippocampi, had a significant impact on longitudinal scores. Dichotomized dose distributions at 25 Gy, 35 Gy, 45 Gy, and 55 Gy were modeled to show the impact of the high-dose volume on longitudinal test scores. The 50% risk of a below-normal cognitive test score was calculated according to mean dose and dose intervals between 25 Gy and 55 Gy at 10-Gy increments according to brain volume and age. Conclusions: The ability to predict cognitive outcomes in children with medulloblastoma using dose-effects models for different brain subvolumes will improve treatment planning, guide intervention, and help

  9. Critical Combinations of Radiation Dose and Volume Predict Intelligence Quotient and Academic Achievement Scores After Craniospinal Irradiation in Children With Medulloblastoma

    International Nuclear Information System (INIS)

    Merchant, Thomas E.; Schreiber, Jane E.; Wu, Shengjie; Lukose, Renin; Xiong, Xiaoping; Gajjar, Amar

    2014-01-01

    Purpose: To prospectively follow children treated with craniospinal irradiation to determine critical combinations of radiation dose and volume that would predict for cognitive effects. Methods and Materials: Between 1996 and 2003, 58 patients (median age 8.14 years, range 3.99-20.11 years) with medulloblastoma received risk-adapted craniospinal irradiation followed by dose-intense chemotherapy and were followed longitudinally with multiple cognitive evaluations (through 5 years after treatment) that included intelligence quotient (estimated intelligence quotient, full-scale, verbal, and performance) and academic achievement (math, reading, spelling) tests. Craniospinal irradiation consisted of 23.4 Gy for average-risk patients (nonmetastatic) and 36-39.6 Gy for high-risk patients (metastatic or residual disease >1.5 cm 2 ). The primary site was treated using conformal or intensity modulated radiation therapy using a 2-cm clinical target volume margin. The effect of clinical variables and radiation dose to different brain volumes were modeled to estimate cognitive scores after treatment. Results: A decline with time for all test scores was observed for the entire cohort. Sex, race, and cerebrospinal fluid shunt status had a significant impact on baseline scores. Age and mean radiation dose to specific brain volumes, including the temporal lobes and hippocampi, had a significant impact on longitudinal scores. Dichotomized dose distributions at 25 Gy, 35 Gy, 45 Gy, and 55 Gy were modeled to show the impact of the high-dose volume on longitudinal test scores. The 50% risk of a below-normal cognitive test score was calculated according to mean dose and dose intervals between 25 Gy and 55 Gy at 10-Gy increments according to brain volume and age. Conclusions: The ability to predict cognitive outcomes in children with medulloblastoma using dose-effects models for different brain subvolumes will improve treatment planning, guide intervention, and help estimate

  10. TH-C-BRD-12: Robust Intensity Modulated Proton Therapy Plan Can Eliminate Junction Shifts for Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Liao, L; Jiang, S; Li, Y; Wang, X; Li, H; Zhu, X; Sahoo, N; Gillin, M; Mahajan, A; Grosshans, D; Zhang, X; Lim, G

    2014-01-01

    Purpose: The passive scattering proton therapy (PSPT) technique is the commonly used radiotherapy technique for craniospinal irradiation (CSI). However, PSPT involves many numbers of junction shifts applied over the course of treatment to reduce the cold and hot regions caused by field mismatching. In this work, we introduced a robust planning approach to develop an optimal and clinical efficient techniques for CSI using intensity modulated proton therapy (IMPT) so that junction shifts can essentially be eliminated. Methods: The intra-fractional uncertainty, in which two overlapping fields shift in the opposite directions along the craniospinal axis, are incorporated into the robust optimization algorithm. Treatment plans with junction sizes 3,5,10,15,20,25 cm were designed and compared with the plan designed using the non-robust optimization. Robustness of the plans were evaluated based on dose profiles along the craniospinal axis for the plans applying 3 mm intra-fractional shift. The dose intra-fraction variations (DIV) at the junction are used to evaluate the robustness of the plans. Results: The DIVs are 7.9%, 6.3%, 5.0%, 3.8%, 2.8% and 2.2%, for the robustly optimized plans with junction sizes 3,5,10,15,20,25 cm. The DIV are 10% for the non-robustly optimized plans with junction size 25 cm. The dose profiles along the craniospinal axis exhibit gradual and tapered dose distribution. Using DIVs less than 5% as maximum acceptable intrafractional variation, the overlapping region can be reduced to 10 cm, leading to potential reduced number of the fields. The DIVs are less than 5% for 5 mm intra-fractional shifts with junction size 25 cm, leading to potential no-junction-shift for CSI using IMPT. Conclusion: This work is the first report of the robust optimization on CSI based on IMPT. We demonstrate that robust optimization can lead to much efficient carniospinal irradiation by eliminating the junction shifts

  11. Craniospinal irradiation with concurrent temozolomide for primary metastatic pediatric high-grade or diffuse intrinsic pontine gliomas. A first report from the GPOH-HIT-HGG Study Group

    International Nuclear Information System (INIS)

    Mueller, K.; Schlamann, A.; Pietschmann, S.; Kortmann, R.D.; Guckenberger, M.; Warmuth-Metz, M.; Glueck, A.; Wawer, A.; Kramm, C.; Bueren, A.O. von

    2014-01-01

    High-grade (HGG) and diffuse intrinsic pontine gliomas (DIPG) with primary metastatic spread are extremely rare and have a dismal prognosis. Analogous to simultaneous radiochemotherapy in non-metastatic HGG and DIPG, concurrent craniospinal irradiation (CSI) and metronomic temozolomide (metroTMZ) may represent a reasonable therapeutic approach. However, the antitumor efficacy and toxicity of this treatment still have to be investigated. Between March 2007 and December 2012, six children with primary metastatic HGG (n=4) or DIPG (n=2) received CSI and concurrent metroTMZ based on individual treatment recommendations and, in some cases, within the HIT-HGG 2007 multicenter trial. Outcome and treatment-related toxicities were evaluated. All patients received irradiation to the entire craniospinal axis (35.2 Gy, n=5; 36 Gy, n=1:) and 5 received a local boost to macroscopic tumor deposits. Simultaneously, metroTMZ (75 mg/m 2 /day, n=5; 60 mg/m 2 /day, n=1) was administered. Additionally, 1 patient received nimotuzumab once per week. Within a median follow-up of 10.0 months (range 6.5-18.7 months), all patients experienced disease progression and 5 patients died. Median progression-free survival was 4.0±0.8 months (range 2.4-10.7 months) and median overall survival was 7.6±3.5 months (range 4.0-17.6 months). Acute myelosuppression most severely limited application of this aggressive treatment strategy. Severe hematotoxicities (= grade 3) occurred in all patients and metroTMZ had to be interrupted or discontinued in 4 out of 6 cases. Concurrent CSI and metroTMZ might represent a feasible treatment approach for primary metastatic HGG and DIPG. On the basis of our experience, severe but manageable acute hematotoxicity has to be expected. An international effort is warranted to reassess the efficacy and toxicity of this approach within a prospective study. (orig.)

  12. Craniospinal irradiation with concurrent temozolomide for primary metastatic pediatric high-grade or diffuse intrinsic pontine gliomas. A first report from the GPOH-HIT-HGG Study Group

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, K.; Schlamann, A.; Pietschmann, S.; Kortmann, R.D. [University Medical Center Leipzig, Department of Radiation Oncology, Leipzig (Germany); Guckenberger, M. [University Medical Center Wuerzburg, Department of Radiation Oncology, Wuerzburg (Germany); Warmuth-Metz, M. [University Medical Center Wuerzburg, Department of Neuroradiology, Wuerzburg (Germany); Glueck, A. [Clinic for Radiation Oncology Schwabing, Muenchen (Germany); Wawer, A. [University Medical Center Muenchen Schwabing, Department of Pediatric Hematology and Oncology, Muenchen (Germany); Kramm, C.; Bueren, A.O. von [University Medical Center Goettingen, Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Goettingen (Germany)

    2014-04-15

    High-grade (HGG) and diffuse intrinsic pontine gliomas (DIPG) with primary metastatic spread are extremely rare and have a dismal prognosis. Analogous to simultaneous radiochemotherapy in non-metastatic HGG and DIPG, concurrent craniospinal irradiation (CSI) and metronomic temozolomide (metroTMZ) may represent a reasonable therapeutic approach. However, the antitumor efficacy and toxicity of this treatment still have to be investigated. Between March 2007 and December 2012, six children with primary metastatic HGG (n=4) or DIPG (n=2) received CSI and concurrent metroTMZ based on individual treatment recommendations and, in some cases, within the HIT-HGG 2007 multicenter trial. Outcome and treatment-related toxicities were evaluated. All patients received irradiation to the entire craniospinal axis (35.2 Gy, n=5; 36 Gy, n=1:) and 5 received a local boost to macroscopic tumor deposits. Simultaneously, metroTMZ (75 mg/m{sup 2}/day, n=5; 60 mg/m{sup 2}/day, n=1) was administered. Additionally, 1 patient received nimotuzumab once per week. Within a median follow-up of 10.0 months (range 6.5-18.7 months), all patients experienced disease progression and 5 patients died. Median progression-free survival was 4.0±0.8 months (range 2.4-10.7 months) and median overall survival was 7.6±3.5 months (range 4.0-17.6 months). Acute myelosuppression most severely limited application of this aggressive treatment strategy. Severe hematotoxicities (= grade 3) occurred in all patients and metroTMZ had to be interrupted or discontinued in 4 out of 6 cases. Concurrent CSI and metroTMZ might represent a feasible treatment approach for primary metastatic HGG and DIPG. On the basis of our experience, severe but manageable acute hematotoxicity has to be expected. An international effort is warranted to reassess the efficacy and toxicity of this approach within a prospective study. (orig.)

  13. A mono isocentric radiotherapy technique for craniospinal irradiation using asymmetric jaws

    International Nuclear Information System (INIS)

    Isin, G; Oezyar, E.; Guerdalli, S.; Arslan, G.; Uzal, D.; Atahan, I. L.

    1995-01-01

    Dose distribution across the junction of matching of craniospinal fields (lateral cranial fields and posterior spinal field) is important as severe complications may result if the beams overlap or disease may recurs if the gapping is too conservative. Various techniques have been used to achieve an effective transverse plane match and half-beam block technique is one of these techniques. Here, we describe a mono isocentric technique for the treatment of craniospinal fields using the asymmetric jaws of our linear accelerator (Philips SL-25). Before the clinical application of this non-standard technique, basic dosimetry parameters are evaluated. Asymmetric collimator dose distributions for various asymmetric field sizes were obtained and compared with symmetric dose distributions for 6 MV x-ray. A computerized 3-D water phantom with a pair of ionization chambers (reference and field) was used for dose profiles, isodose distributions and Percentage Depth Dose (PDD) for various asymmetric field sizes and different off axis distances. The measured values of off axis ratios for the interested depths were used in MU calculations. This new mono isocentric technique provides an ideal dose distribution at match-line as there is no need to move the patient during treatment. Use of heavy secondary cerrobend blocks (beam splitters) is eliminated. This technique provides the ease of consequent daily set-up's and fulfills the requirements for a conformal radiotherapy

  14. The influence of body position on cerebrospinal fluid pressure gradient and movement in cats with normal and impaired craniospinal communication.

    Science.gov (United States)

    Klarica, Marijan; Radoš, Milan; Erceg, Gorislav; Petošić, Antonio; Jurjević, Ivana; Orešković, Darko

    2014-01-01

    Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF) pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension.

  15. The influence of body position on cerebrospinal fluid pressure gradient and movement in cats with normal and impaired craniospinal communication.

    Directory of Open Access Journals (Sweden)

    Marijan Klarica

    Full Text Available Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension.

  16. 26 CFR 1.668(a)-1 - Amounts treated as received in prior taxable years; inclusion in gross income.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Amounts treated as received in prior taxable years; inclusion in gross income. 1.668(a)-1 Section 1.668(a)-1 Internal Revenue INTERNAL REVENUE... treated as received in prior taxable years; inclusion in gross income. (a) Section 668(a) provides that...

  17. Functional modeling of the craniospinal system for in-vitro parameter studies on the pathogenesis of NPH

    Directory of Open Access Journals (Sweden)

    Benninghaus Anne

    2017-09-01

    Full Text Available Normal Pressure Hydrocephalus (NPH has become a common disease in the elderly coming along with typical symptoms of dementia, gait ataxia and urinary incontinence, which make the differential diagnosis with other forms of dementia difficult. Furthermore the pathogenesis of NPH is still not understood. About 10% of all demented patients might be suffering from NPH [1]. Many hypotheses suggest that modified biomechanical boundary conditions affect the craniospinal dynamics inducing the pathogenesis of NPH. We present a novel approach for an in-vitro model of the craniospinal system to investigate important hydrodynamic influences on the system such as (dynamic compliance of the vascular system and especially the spinal subarachnoid space (SAS as well as reabsorption and hydrostatics. The experimental set-up enables the individual adjustment of relevant parameters for sensitivity analyses regarding the impact of resulting CSF dynamics on the pathogenesis of NPH.

  18. Survival and Neurocognitive Outcomes After Cranial or Craniospinal Irradiation Plus Total-Body Irradiation Before Stem Cell Transplantation in Pediatric Leukemia Patients With Central Nervous System Involvement

    International Nuclear Information System (INIS)

    Hiniker, Susan M.; Agarwal, Rajni; Modlin, Leslie A.; Gray, Christine C.; Harris, Jeremy P.; Million, Lynn; Kiamanesh, Eileen F.; Donaldson, Sarah S.

    2014-01-01

    Purpose: To evaluate survival and neurocognitive outcomes in pediatric acute lymphoblastic leukemia (ALL) patients with central nervous system (CNS) involvement treated according to an institutional protocol with stem cell transplantation (SCT) and a component of craniospinal irradiation (CSI) in addition to total-body irradiation (TBI) as preparative regimen. Methods and Materials: Forty-one pediatric ALL patients underwent SCT with TBI and received additional cranial irradiation or CSI because of CNS leukemic involvement. Prospective neurocognitive testing was performed before and after SCT in a subset of patients. Cox regression models were used to determine associations of patient and disease characteristics and treatment methods with outcomes. Results: All patients received a cranial radiation boost; median total cranial dose was 24 Gy. Eighteen patients (44%) received a spinal boost; median total spinal dose for these patients was 18 Gy. Five-year disease-free survival (DFS) for all patients was 67%. Those receiving CSI had a trend toward superior DFS compared with those receiving a cranial boost alone (hazard ratio 3.23, P=.14). Patients with isolated CNS disease before SCT had a trend toward superior DFS (hazard ratio 3.64, P=.11, 5-year DFS 74%) compared with those with combined CNS and bone marrow disease (5-year DFS 59%). Neurocognitive testing revealed a mean post-SCT overall intelligence quotient of 103.7 at 4.4 years. Relative deficiencies in processing speed and/or working memory were noted in 6 of 16 tested patients (38%). Pre- and post-SCT neurocognitive testing revealed no significant change in intelligence quotient (mean increase +4.7 points). At a mean of 12.5 years after transplant, 11 of 13 long-term survivors (85%) had completed at least some coursework at a 2- or 4-year college. Conclusion: The addition of CSI to TBI before SCT in pediatric ALL with CNS involvement is effective and well-tolerated. Craniospinal irradiation plus TBI is worthy

  19. Survival and Neurocognitive Outcomes After Cranial or Craniospinal Irradiation Plus Total-Body Irradiation Before Stem Cell Transplantation in Pediatric Leukemia Patients With Central Nervous System Involvement

    Energy Technology Data Exchange (ETDEWEB)

    Hiniker, Susan M. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Agarwal, Rajni [Section of Stem Cell Transplantation, Department of Pediatrics, Stanford University, Stanford, California (United States); Modlin, Leslie A. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Gray, Christine C. [Division of Child and Adolescent Psychiatry, Department of Psychiatry, Stanford University, Stanford, California (United States); Harris, Jeremy P.; Million, Lynn [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Kiamanesh, Eileen F. [Cancer Clinical Trials Office, Stanford Cancer Institute, Stanford University, Stanford, California (United States); Donaldson, Sarah S., E-mail: sarah2@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California (United States)

    2014-05-01

    Purpose: To evaluate survival and neurocognitive outcomes in pediatric acute lymphoblastic leukemia (ALL) patients with central nervous system (CNS) involvement treated according to an institutional protocol with stem cell transplantation (SCT) and a component of craniospinal irradiation (CSI) in addition to total-body irradiation (TBI) as preparative regimen. Methods and Materials: Forty-one pediatric ALL patients underwent SCT with TBI and received additional cranial irradiation or CSI because of CNS leukemic involvement. Prospective neurocognitive testing was performed before and after SCT in a subset of patients. Cox regression models were used to determine associations of patient and disease characteristics and treatment methods with outcomes. Results: All patients received a cranial radiation boost; median total cranial dose was 24 Gy. Eighteen patients (44%) received a spinal boost; median total spinal dose for these patients was 18 Gy. Five-year disease-free survival (DFS) for all patients was 67%. Those receiving CSI had a trend toward superior DFS compared with those receiving a cranial boost alone (hazard ratio 3.23, P=.14). Patients with isolated CNS disease before SCT had a trend toward superior DFS (hazard ratio 3.64, P=.11, 5-year DFS 74%) compared with those with combined CNS and bone marrow disease (5-year DFS 59%). Neurocognitive testing revealed a mean post-SCT overall intelligence quotient of 103.7 at 4.4 years. Relative deficiencies in processing speed and/or working memory were noted in 6 of 16 tested patients (38%). Pre- and post-SCT neurocognitive testing revealed no significant change in intelligence quotient (mean increase +4.7 points). At a mean of 12.5 years after transplant, 11 of 13 long-term survivors (85%) had completed at least some coursework at a 2- or 4-year college. Conclusion: The addition of CSI to TBI before SCT in pediatric ALL with CNS involvement is effective and well-tolerated. Craniospinal irradiation plus TBI is worthy

  20. Nuclear-magnetic tomography in the differential diagnosis of syringobulbia and craniospinal tumors

    International Nuclear Information System (INIS)

    Akhadov, T.A.; Belov, S.A.; Kravtsov, A.K.; Panov, V.O.; Sachkova, I.Yu.

    1993-01-01

    Studies carried out in 43 patients helped distinguish the NMT symptoms most characteristic of syringobulbia: a centrally located echo signal zone in the medulla oblongata and the cord, increased transverse size of the medulla oblongata and the spinal cord, dilated volumes of the basal cysterns. A craniospinal condition resultant from a tumor process is characterized by detection of a bulky formation with a heterologus structure in the medulla oblongata involving the cervical portion of the cord and the cerebellar

  1. 26 CFR 1.668(a)-1A - Amounts treated as received in prior taxable years; inclusion in gross income.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Amounts treated as received in prior taxable years; inclusion in gross income. 1.668(a)-1A Section 1.668(a)-1A Internal Revenue INTERNAL REVENUE... treated as received in prior taxable years; inclusion in gross income. (a) Section 668(a) provides that...

  2. SU-E-T-371: Validation of Organ Doses Delivered During Craniospinal Irradiation with Helical Tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Andujar, A; Chen, J; Garcia, A; Haas-Kogan, D [University of San Francisco, San Francisco, CA (United States)

    2014-06-01

    Purpose: New techniques have been developed to deliver more conformal treatments to the craniospinal axis. One concern, however, is the widespread low dose delivered and implications for possible late effects. The purpose of this work is for the first time to validate the organ doses calculated by the treatment planning system (TPS), including out-of-field doses for a pediatric craniospinal treatment (CSI). Methods: A CSI plan prescribed to 23.4 Gy and a posterior fossa boost plan to 30.6 Gy (total dose 54.0 Gy) was developed for a pediatric anthropomorphic phantom representing a 13 yearold- child. For the CSI plan, the planning target volumes (PTV) consisted of the brain and spinal cord with 2 mm and 5 mm expansions, respectively. Organs at risk (OAR) were contoured and included in the plan optimization. The plans were delivered on a helical tomotherapy unit. Thermoluminescent dosimeters (TLDs) were used to measure the dose at 54 positions within the PTV and OARs. Results: For the CSI treatment, the mean percent difference between TPS dose calculations and measurements was 5% for the PTV and 10% for the OARs. For the boost, the average was 3% for the PTV. The percent difference for the OARs, which lie outside the field and received a small fraction of the prescription dose, varied from 15% to 200%. However in terms of absolute dose, the average difference between measurement and TPS per treatment Gy was 2 cGy/Gy and 3 mGy/Gy for the CSI and boost plans, respectively. Conclusion: There was good agreement between doses calculated by the TPS and measurements for the CSI treatment. Higher percent differences were observed for out-of-field doses in the boost plan, but absolute dose differences were very small compared to the prescription dose. These findings can help in the estimation of late effects after radiotherapy for pediatric patients.

  3. SU-E-T-229: Craniospinal Radiotherapy Planning with VMAT, Two First Years Experience

    Energy Technology Data Exchange (ETDEWEB)

    Lliso, F; Carmona, V; Gimeno, J; Candela-Juan, C; Bautista, J [La Fe University and Polytechnic Hospital, Valencia, Valencia (Spain); Richart, J [ITIC, Hospital Clinica Benidorm, Benidorm, Alicante (Spain); Perez-Calatayud, J [La Fe University and Polytechnic Hospital, Valencia, Valencia (Spain); ITIC, Hospital Clinica Benidorm, Benidorm, Alicante (Spain)

    2015-06-15

    Purpose: To describe how we moved to VMAT in the craniospinal radiotherapy planning process, the actual procedure details, and the results for the patients treated. Methods: Twelve patients underwent craniospinal irradiation with the new procedure, based on the paper by Lee et al. (IJROBP 82, 2012), with some additional modifications. Patients were treated in supine position in Varian Clinac iX linacs with 6 MV RapidArc; prescription doses ranged from 23.4 to 40 Gy (13 to 20 fractions); depending on the PTV length, 2 or 3 isocenters were used, all coordinates being equal except the longitudinal one, setting a few centimeter-long overlapping region; 2 arcs (RA) sharing isocentre for the cranial region, RA1 encompassing cranium and superior spinal region, and RA2 intended to improve conformity, only for cranium; for spine, 1 or 2 isocenters were employed; optimization was performed with Eclipse (V 13.0) using AAA algorithm, establishing sets of optimization parameters to give high conformity while sparing OAR. In pediatric patients, homogeneous irradiation of the vertebrae was also required.Conformity (CI) and heterogeneity (HI) indices (same as Lee et al.), and mean and maximum doses for OAR were calculated. Several pre-treatment verification methods were used: Octavius4D (PTW) for each isocentre, point dose at the junction region, Portal Dosimetry (when possible), and independent MU verification software (Diamond, PTW). Results: CI median value was 1.02 (0.99–1.07) and HI, 1.07 (1.06–1.09); a great reduction was observed for CI and OAR mean doses with respect to Lee et al. data; median maximum eye lens dose was 7.3 Gy (4.0–12.0); mean LungV20Gy was 1.9%; in children, vertebrae were homogeneously irradiated (D95%=20.8 Gy, Dmean= 23.2 Gy).All pre-treatment verifications were found within our action levels except for Portal Dosimetry. Conclusion: A RapidArc planning process for craniospinal axis irradiation has been implemented with significant advantages on

  4. CNS germinoma: disease control and long-term functional outcome for 12 children treated with craniospinal irradiation

    International Nuclear Information System (INIS)

    Merchant, Thomas E.; Sherwood, Scot H.; Mulhern, Raymond K.; Rose, Susan R.; Thompson, Stephen J.; Sanford, Robert A.; Kun, Larry E.

    2000-01-01

    Purpose: To provide evidence that radiation therapy alone in the form of craniospinal irradiation (CSI) and a boost to the primary site of disease provides effective disease control and limited additional morbidity for patients with CNS germinoma. Methods and Materials: Twelve patients with a median age of 12 years (range 9-16 years) with CNS germinoma were treated with CSI (median 25.6 Gy, range 23.4-32 Gy) and a boost to the primary site of disease (50.4 Gy, range 45-54 Gy) between January 1987 and June 1998. All patients were biopsied prior to radiation therapy and none received chemotherapy. No patients were lost to follow-up and the majority had long-term (> 45 month) pre- and postirradiation endocrine and psychology assessment. Results: All 12 patients are alive and no failures have occurred with a median follow-up of 69 months (range 14-143 months). Preirradiation endocrine deficiencies were present in 6 of 6 suprasellar tumors and 1 of 6 pineal tumors; with follow-up there was no substantial difference between age and gender adjusted pre- and postirradiation stature and weight. With long-term follow-up, there were no significant differences between pre- and postirradiation full-scale, verbal, and performance IQ scores. Conclusions: This study confirms the ability of radiation therapy alone to achieve disease control with a high rate of success in pediatric patients and demonstrates that the treatment toxicity faced by these patients may be less than anticipated. Because these patients present with substantial preexisting morbidity at diagnosis and may be of an age where the potential for radiation-related side effects is relatively small, the superiority of treatment alternatives may be difficult to prove

  5. Craniospinal treatment with IMRT multi-isocentric and image-guided linear accelerator based on Gantry

    International Nuclear Information System (INIS)

    Sanz Beltran, M.; Caballero Perea, B.; Rodriguez Rodriguez, C.; Arminio Diaz, E.; Lopez Fernandez, A.; Gomez Fervienza, J. R.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.; Gomez Fervienza, J. r.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.

    2011-01-01

    The objective is the realization of craniospinal treatment with a linear accelerator equipped with gantry based on MLC, carbon fiber table and Image Guided capability. The great length of treatment (patient l,80m in height) was a great difficulty for want of full length of the longitudinal movement of the table to adequately cover the PTV, plus free metallic screws fastening the head of the table extender preventing further incidents.

  6. Cognitive functioning in long-term survivors of childhood leukemia: A prospective analysis

    International Nuclear Information System (INIS)

    Rubenstein, C.L.; Varni, J.W.; Katz, E.R.

    1990-01-01

    Treatment-related cognitive impairments have been reported for survivors of childhood leukemia following prophylactic central nervous system (CNS) treatment with 2400 cGy craniospinal irradiation and intrathecal chemotherapy. The present study was designed to prospectively evaluate cognitive functioning of 24 children prior to CNS prophylaxis of 1800 cGy of craniospinal irradiation and intrathecal drugs, and at intervals of 1 and 4-5 years. At diagnosis, prior to CNS treatment, all 24 subjects performed in the average range of intelligence, as measured by the Wechsler Intelligence Scales. Subjects continued to perform in the average range with no significant declines at the 1-year follow-up. Significant declines in cognitive functioning, however, were found at the 4- to 5-year follow-up period, with five subjects (21%) performing in the low average or borderline levels of intelligence. Of the 19 subjects performing in the average range, five showed significant discrepancies between Verbal and Performance IQ scores. Nine subjects exhibited poor performance on a subtest cluster assessing perceptual and attentional processes. With regard to school experiences, 50% of the subjects had received some type of special education services. The findings indicate the need for annual evaluations of cognitive functioning in long-term survivors of childhood leukemia who received 1800 cGy craniospinal irradiation, to identify potential cognitive late effects of treatment requiring appropriate special education services

  7. Supine Craniospinal Irradiation Using Intrafractional Junction Shifts and Field-in-Field Dose Shaping: Early Experience at Methodist Hospital

    International Nuclear Information System (INIS)

    South, Michael C.; Chiu, J. Kam; Teh, Bin S.; Bloch, Charles; Schroeder, Thomas M.; Paulino, Arnold C.

    2008-01-01

    Purpose: To describe our preliminary experience with supine craniospinal irradiation. The advantages of the supine position for craniospinal irradiation include patient comfort, easier access to maintain an airway for anesthesia, and reduced variability of the head tilt in the face mask. Methods and Materials: The cranial fields were treated with near lateral fields and a table angle to match their divergence to the superior edge of the spinal field. The collimator was rotated to match the divergence from the superior spinal field. The spinal fields were treated using a source to surface distance (SSD) technique with the couch top at 100 cm. When a second spinal field was required, the table and collimator were rotated 90 o to allow for the use of the multileaf collimator and so the gantry could be rotated to match the divergence of the superior spinal field. The multileaf collimator was used for daily dynamic featherings and field-in-field dose control. Results: With a median follow-up of 20.2 months, five documented failures and no cases of radiation myelitis occurred in 23 consecutive patients. No failures occurred in the junctions of the spine-spine or brain-spine fields. Two failures occurred in the primary site alone, two in the spinal axis alone, and one primary site failure plus distant metastasis. The median time to recurrence was 17 months. Conclusion: The results of our study have shown that supine approach for delivering craniospinal irradiation is not associated with increased relapses at the field junctions. To date, no cases of radiation myelitis have developed

  8. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort.

    Science.gov (United States)

    Mah, K; Danjoux, C E; Manship, S; Makhani, N; Cardoso, M; Sixel, K E

    1998-07-15

    To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of > or =5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization.

  9. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort

    International Nuclear Information System (INIS)

    Mah, Katherine; Danjoux, Cyril E.; Manship, Sharan; Makhani, Nadiya; Cardoso, Marlene; Sixel, Katharina E.

    1998-01-01

    Purpose: To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. Methods and Materials: A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Results: Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was <10 min in all cases. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of ≥5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Conclusions: Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall

  10. Postponed Is Not Canceled: Role of Craniospinal Radiation Therapy in the Management of Recurrent Infant Medulloblastoma—An Experience From the HIT-REZ 1997 and 2005 Studies

    Energy Technology Data Exchange (ETDEWEB)

    Müller, Klaus, E-mail: Klaus.Mueller@medizin.uni-leipzig.de [Department of Radiation Oncology, University of Leipzig Medical Center, Leipzig (Germany); Mynarek, Martin [Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Zwiener, Isabella [Institute for Medical Biostatistics, Epidemiology and Informatics, University of Mainz Medical Center, Mainz (Germany); Siegler, Nele [University Hospital of Essen, Pediatrics III, Essen (Germany); Zimmermann, Martina [Department of Pediatric Hematology and Oncology, Children' s Hospital, University Hospital of Bonn, Bonn (Germany); Christiansen, Hans [Department of Radiotherapy, Hannover Medical School, Hannover (Germany); Budach, Wilfried [Clinic and Policlinic for Radiation Therapy and Radiooncology, University of Düsseldorf, Düsseldorf (Germany); Henke, Guido [Department of Radiation Oncology, Kantonsspital St. Gallen, St. Gallen (Switzerland); Warmuth-Metz, Monika [Department of Neuroradiology, University of Würzburg, Würzburg (Germany); Pietsch, Torsten [Department of Neuropathology, University of Bonn Medical Center, Bonn (Germany); Hoff, Katja von [Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Bueren, Andre von [Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Göttingen (Germany); Bode, Udo [Department of Pediatric Hematology and Oncology, Children' s Hospital, University Hospital of Bonn, Bonn (Germany); and others

    2014-04-01

    Purpose: To evaluate the efficacy of craniospinal irradiation (CSI) in the management of recurrent infant medulloblastoma after surgery and chemotherapy alone. Methods and Materials: Seventeen pediatric medulloblastoma patients registered in the HIT-REZ 1997 and 2005 studies underwent CSI as salvage treatment at first recurrence. All patients had achieved complete remission after first-line treatment consisting of surgery and chemotherapy. Eleven patients showed metastatic disease at relapse. Five patients underwent surgery prior to radiation therapy, which resulted in complete resection in 1 case. In 1 patient, complete resection of the residual tumor was performed after CSI. Eleven patients received chemotherapy prior, 6 patients during and 8 patients after CSI. All patients received CSI with a median total dose of 35.2 Gy, and all but 1 received a boost to the posterior fossa (median total dose, 55.0 Gy). Metastases were boosted with an individual radiation dose, depending on their location and extent. Results: During a median follow-up time of 6.2 years since recurrence, 11 patients showed progressive disease and died. Median progression-free (overall) survival was 2.9 ± 1.1 (3.8 ± 0.8) years. Progression-free survival (PFS) rates at 1, 3, and 5 years were 88% ± 8%, 46% ± 12%, and 40% ± 12%, respectively. Overall survival (OS) rates at 1, 3, and 5 years were 94% ± 6%, 58% ± 12%, and 39% ± 12%, respectively. For 11 patients with classic medulloblastoma, 3-year (and 5-year) PFS and OS were 62% ± 15% and 72% ± 14% (52% ± 16% and 51% ± 16%), respectively. On univariate analysis, metastatic disease was not associated with poorer progression-free and overall survival. Conclusions: Our results suggest that salvage treatment of relapsed medulloblastomas consisting of CSI and chemotherapy offers a second chance for cure, even for patients with classic histological findings. Metastatic disease at relapse did not have an impact

  11. Radiotherapy in metastatic diseases of the cervical spine and the craniospinal region

    International Nuclear Information System (INIS)

    Mende, U.; Braun, A.; Reiden, K.; Voth, D.; Glees, P.

    1987-01-01

    The results of large autopsy studies indicate that 20 to 30% of all patients with carcinoma will develop sooner or later bone metastases. According to the incidence of the primary tumor itself as well as to its tendency to metastasize into the skeletal system more than 80% of all bone metastases are due to neoplasms of the breast, prostate, bronchus, kidney and thyroid. Most of the metastases are found in the red marrow with an unequivocal preference to the axial skeleton. This article discusses radiotherapy in metastatic diseases of the cervical spine and the craniospinal region

  12. Determination of the inferior border of the thecal sac using magnetic resonance imaging: implications on craniospinal irradiation

    International Nuclear Information System (INIS)

    Scharf, Carole B.; Goldberg, Kenneth; Paulino, Arnold C.

    1996-01-01

    Purpose: Craniospinal irradiation (CSI) is employed in medulloblastoma and other intracranial malignancies that can seed the neuro axis. Care must be taken to adequately cover the entire craniospinal axis, including the distal thecal sac. The inferior border of the craniospinal field has traditionally been placed at the bottom of the S2 vertebra. The purpose of this study is to review the level of thecal sac termination in children undergoing CSI using Magnetic Resonance Imaging (MRI). Methods and Materials: From (12(87)) to (10(95)), 22 children were treated with CSI at one institution. All underwent pre-treatment MRI of the spine with Gadolinium as part of their evaluation. The median age was 9 years (range, 31 months to 18 years), and there were 14 males and 8 females. The diagnosis was medulloblastoma in 14 patients, primitive neuroectodermal tumor of the cerebrum in 3, germinoma in 2, pineoblastoma in 1, leptomeningeal gliomatosis in 1 and glioblastoma multiform in 1. All spinal MRIs were reviewed by both neuro radiologist and radiation oncologist to accurately determine the level of thecal sac termination which was obtained by drawing a horizontal line from the lower limit of the spinal theca to the corresponding adjacent vertebral body. Results: The thecal sac termination varied from mid S1 to lower S3. It was located at mid S1 in 1 patient, lower S1 in 3, S1-2 junction in 3, upper S2 in 5, mid S2 in 3, lower S2 in 3, S2-3 junction in 2, upper S3 in 1 and lower S3 in 1. Only (2(22)) patients (9%) had thecal sac terminations below the S2-3 junction. Eight patients had spinal axis involvement and their thecal sac terminations were all above the S2-3 junction. There was no correlation between the level of termination and age, gender or histology. Conclusions: The majority of patients (91%) will have termination of the thecal sac above S3, and therefore placement of the inferior border of the spinal field at the S2-3 junction with a 1 cm caudal margin will be

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

    International Nuclear Information System (INIS)

    Merchant, Thomas E.; Kun, Larry E.; Krasin, Matthew J.; Wallace, Dana; Chintagumpala, Murali M.; Woo, Shiao Y.; Ashley, David M.; Sexton, Maree; Kellie, Stewart J.; Ahern, Verity M.B.B.S.; Gajjar, Amar

    2008-01-01

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

  14. Updated results of a pilot study of low dose craniospinal irradiation plus chemotherapy for children under five with cerebellar primitive neuroectodermal tumors (medulloblastoma)

    International Nuclear Information System (INIS)

    Goldwein, Joel W.; Radcliffe, Jerilynn; Johnson, James; Moshang, Thomas; Packer, Roger J.; Sutton, Leslie N.; Rorke, Lucy B.; D'Angio, Giulio J.

    1996-01-01

    velocities during the follow-up period, while the others grew normally. Three patients have received growth hormone, and none have required thyroid replacement. Conclusions: These data suggest that medulloblastoma patients can be cured with chemotherapy and reduced doses of craniospinal irradiation. The low doses of CSART given by us in conjunction with cis-platin-based chemotherapy produce minimal neurocognitive damage. Growth velocities in very young children so treated are, however, dramatically reduced. Better means of improving the therapeutic ratio are still needed

  15. A comparison of optic nerve dosimetry in craniospinal radiotherapy planned and treated with conventional and intensity modulated techniques

    International Nuclear Information System (INIS)

    Rene, Nicholas J.; Brodeur, Marylene; Parker, William; Roberge, David; Freeman, Carolyn

    2010-01-01

    Background and purpose: Some CNS tumours present leptomeningeal dissemination. Craniospinal radiotherapy is complex and recurrences may occur at sites of target volume underdosage. IMRT, being highly conformal to the target, could theoretically underdose the optic nerves if they are not specifically targeted leading to optic nerve recurrences. We analyzed optic nerve dosimetry when they are not specifically targeted. Materials and methods: We designed 3D-conformal and tomotherapy plans for our last five patients treated to the craniospinal axis, not including the optic nerves in the target volume. We analyzed the dose delivered to the optic nerves, to the anterior and posterior half of the optic nerves, and to a theoretical optic nerve-PTV. Results: The dose delivered to the optic nerves was similar for both plans in all patients (V95% close to 100%) except one in whom tomotherapy considerably underdosed the anterior optic nerves. The dose to the optic nerve-PTV was lower with tomotherapy in all patients. Conclusion: Despite not intentionally targeting the optic nerves, the dose to the optic nerves with IMRT was similar to 3D-conformal plans in most cases but left no margin for setup error. In individual cases the anterior half of the optic nerves could be significantly underdosed.

  16. Management Strategies and Outcomes for VHL-related Craniospinal Hemangioblastomas

    Directory of Open Access Journals (Sweden)

    Christ Ordookhanian

    2017-08-01

    Full Text Available Hemangioblastomas are rare and benign tumors accounting for less than 2% of all central nervous system (CNS tumors. The vast majority of hemangioblastomas occur sporadically, whereas a small number of cases, especially in younger patients, are associated with Von Hippel–Lindau (VHL syndrome. It is thought that loss of tumor suppressor function of the VHL gene results in stabilization of hypoxia-inducible factor alpha with downstream activation of cellular proliferative and angiogenic genes that promote tumorigenesis. VHL-related hemangioblastomas predominantly occur in the cerebellum and spine. Lesions are often diagnosed on contrast-enhanced craniospinal MRIs, and the diagnosis of VHL occurs through assessment for germline VHL mutations. Surgical resection remains the primary treatment modality for symptomatic or worrisome lesions, with excellent local control rates and neurological outcomes. Stereotactic radiotherapy can be employed in patients who are deemed high risk for surgery, have multiple lesions, or have non-resectable lesions. Given the tendency for development of either new or multiple lesions, close radiographic surveillance is often recommended for asymptomatic lesions.

  17. Late effects of craniospinal irradiation for standard risk medulloblastoma in paediatric patients: A comparison of treatment techniques

    International Nuclear Information System (INIS)

    Leman, J.

    2016-01-01

    Background: Survival rates for standard risk medulloblastoma are favourable, but craniospinal irradiation (CSI) necessary to eradicate microscopic spread causes life limiting late effects. Aims: The aim of this paper is to compare CSI techniques in terms of toxicity and quality of life for survivors. Methods and materials: A literature search was conducted using synonyms of ‘medulloblastoma’, ’craniospinal’, ‘radiotherapy’ and ‘side effects’ to highlight 29 papers that would facilitate this discussion. Results and discussion: Intensity modulated radiotherapy (IMRT), tomotherapy and protons all provide CSI which can reduce dose to normal tissue, however photon methods cannot eliminate exit dose as well as protons can. Research for each technique requires longer term follow up in order to prove that survival rates remain high whilst reducing late effects. Findings/conclusion: Proton therapy is the superior method of CSI in term of late effects, but more research is needed to evidence this. Until proton therapy is available in the UK IMRT should be utilised. - Highlights: • Craniospinal irradiation is vital in the treatment of medulloblastoma. • Survivors often suffer long term side effects which reduce quality of life. • Tomotherapy, IMRT and proton therapy reduce late effects by sparing normal tissue. • Proton therapy offers superior dose distribution but further research is necessary. • IMRT should be employed for photon radiotherapy.

  18. Physiologic and Radiographic Evidence of the Distal Edge of the Proton Beam in Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Krejcarek, Stephanie C.; Grant, P. Ellen; Henson, John W.; Tarbell, Nancy J.; Yock, Torunn I.

    2007-01-01

    Purpose: Fatty replacement of bone marrow resulting from radiation therapy can be seen on T1-weighted magnetic resonance (MR) images. We evaluated the radiographic appearance of the vertebral bodies in children treated with proton craniospinal irradiation (CSI) to illustrate the distal edge effect of proton radiotherapy. Methods and Materials: The study cohort consisted of 13 adolescents aged 12-18 years who received CSI with proton radiotherapy at Massachusetts General Hospital. Ten of these patients had reached maximal or near-maximal growth. Proton beam radiation for these 10 patients was delivered to the thecal sac and exiting nerve roots only, whereas the remaining 3 patients had a target volume that included the thecal sac, exiting nerve roots, and entire vertebral bodies. Median CSI dose was 27 [range, 23.4-36] cobalt gray equivalent (CGE) given in 1.8-CGE fractions. Magnetic resonance images of the spine were obtained after completion of radiotherapy. Results: Magnetic resonance images of patients who received proton radiotherapy to the thecal sac only demonstrate a sharp demarcation of hyperintense T1-weighted signal in the posterior aspects of the vertebral bodies, consistent with radiation-associated fatty marrow replacement. Magnetic resonance images of the patients prescribed proton radiotherapy to the entire vertebral column had corresponding hyperintense T1-weighted signal involving the entire vertebral bodies. Conclusion: The sharp delineation of radiation-associated fatty marrow replacement in the vertebral bodies demonstrates the rapid decrease in energy at the edge of the proton beam. This provides evidence for a sharp fall-off in radiation dose and supports the premise that proton radiotherapy spares normal tissues unnecessary irradiation

  19. Comparison of risk of radiogenic second cancer following photon and proton craniospinal irradiation for a pediatric medulloblastoma patient

    Science.gov (United States)

    Zhang, Rui; Howell, Rebecca M.; Giebeler, Annelise; Taddei, Phillip J.; Mahajan, Anita; Newhauser, Wayne D.

    2013-02-01

    Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose-risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose-risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.

  20. Pre-travel advice concerning vector-borne diseases received by travelers prior to visiting Cuzco, Peru.

    Science.gov (United States)

    Mejia, Christian R; Centeno, Emperatriz; Cruz, Briggitte; Cvetkovic-Vega, Aleksandar; Delgado, Edison; Rodriguez-Morales, Alfonso J

    2016-01-01

    Peru is an increasingly popular tourist destination that poses a risk to travelers due to endemic vector-borne diseases (VBDs). The objective of our study was to determine which factors are associated with receiving pre-travel advice (PTA) for VBDs among travelers visiting Cuzco, Peru. A cross-sectional secondary analysis based on data from a survey among travelers departing Cuzco at Alejandro Velazco Astete International Airport during the period January-March 2012 was conducted. From the 1819 travelers included in the original study, 1717 were included in secondary data analysis. Of these participants, 42.2% received PTA and 2.9% were informed about vector-borne diseases, including yellow fever (1.8%), malaria (1.6%) and dengue fever (0.1%). Receiving information on VBDs was associated with visiting areas endemic to yellow fever and dengue fever in Peru. The only disease travelers received specific recommendations for before visiting an endemic area for was yellow fever. Only 1 in 30 tourists received information on VBD prevention; few of those who traveled to an endemic area were warned about specific risks for infectious diseases prior to their trip. These important findings show that most tourists who travel to Peru do not receive PTA for the prevention of infectious and VBD, which can affect not only the travelers but their countries of origin as well. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  1. Frontal recurrence of medulloblastoma five years after excision and craniospinal irradiation

    Directory of Open Access Journals (Sweden)

    Roka Y

    2009-07-01

    Full Text Available Medulloblastomas were originally classified under gliomas of the cerebellum until Bailey and Cushing in 1925 named these tumors as medulloblastoma. At present these tumors are classified under primitive neuroectodermal tumor. Surgical excision followed by craniospinal irradiation is the treatment of choice. A 13-year-old-girl operated for posterior fossa medulloblastoma 5 years ago presented with history of headache and vomiting on and off for 4 days in late August 2008. The MRI showed left frontal tumor which on excision was reported as medulloblastoma. Even after optimal treatment reports of recurrence abound in literature. The most common location is in the posterior fossa, followed by spinal, supratentorial, and uncommonly, systemic metastases. We conclude that medulloblastomas are highly aggressive tumor with high local recurrences if the initial excision is incomplete and that recurrence in the supratentorial area although uncommon is still a possibility. This mandates regular follow up of these children till adulthood to catch early recurrences and metastatic disease.

  2. Response to growth hormone treatment and final height after cranial or craniospinal irradiation

    International Nuclear Information System (INIS)

    Sulmont, V.; Brauner, R.; Fontoura, M.; Rappaport, R.

    1990-01-01

    Growth hormone (GH) deficiency (GHD) induced by cranial irradiation has become a frequent indication of hGH substitutive therapy. This study analyses the growth response to hGH therapy and the factors involved in the decrease in growth velocity observed after cranial irradiation. One hundred children given cranial radiation for pathology distant from the hypothalamo-pituitary area were studied. Fifty-six of them received hGH therapy for GHD resulting in decreased growth velocity. The initial annual height gain in the cranial-irradiated group was comparable to that of patients treated for idiopathic GHD; additional spinal irradiation significantly reduced the growth response. Twenty-eight hGH-treated patients reached final heights which were compared to those of 2 untreated irradiated groups, one with GHD (n=27) and the other with normal GH secretion (n=17). The height SD score changes observed in hGH therapy were +0.3 in the cranial (n=10) and -1.2 SD in the craniospinal (n=18) groups. GH deficiency had contributed to a mean height loss of 1 SD and spinal irradiation to a loss of 1.4SD. The small effect of hGH therapy on final height is probably linked to the small bone age retardation at onset of hGH therapy and to the fact that irradiated children entered puberty at a younger age in terms of chronological age and bone age than the idiopathic GHD patients. These data suggest that the results of gGH therapy in irradiated children might be improved with higher and more fractionated hGH doses and, in some patients, by delaying puberty using luteinizing hormone releasing hormone analogs

  3. Response to growth hormone treatment and final height after cranial or craniospinal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sulmont, V.; Brauner, R.; Fontoura, M.; Rappaport, R. (Hospital des Enfants Malades, Paris (France). Pediatric Endocrinology Unit and INSERM U30)

    1990-01-01

    Growth hormone (GH) deficiency (GHD) induced by cranial irradiation has become a frequent indication of hGH substitutive therapy. This study analyses the growth response to hGH therapy and the factors involved in the decrease in growth velocity observed after cranial irradiation. One hundred children given cranial radiation for pathology distant from the hypothalamo-pituitary area were studied. Fifty-six of them received hGH therapy for GHD resulting in decreased growth velocity. The initial annual height gain in the cranial-irradiated group was comparable to that of patients treated for idiopathic GHD; additional spinal irradiation significantly reduced the growth response. Twenty-eight hGH-treated patients reached final heights which were compared to those of 2 untreated irradiated groups, one with GHD (n=27) and the other with normal GH secretion (n=17). The height SD score changes observed in hGH therapy were +0.3 in the cranial (n=10) and -1.2 SD in the craniospinal (n=18) groups. GH deficiency had contributed to a mean height loss of 1 SD and spinal irradiation to a loss of 1.4SD. The small effect of hGH therapy on final height is probably linked to the small bone age retardation at onset of hGH therapy and to the fact that irradiated children entered puberty at a younger age in terms of chronological age and bone age than the idiopathic GHD patients. These data suggest that the results of gGH therapy in irradiated children might be improved with higher and more fractionated hGH doses and, in some patients, by delaying puberty using luteinizing hormone releasing hormone analogs.

  4. A modified technique for craniospinal irradiation in children designed to reduce acute and late radiation toxicity

    International Nuclear Information System (INIS)

    Phillips, Claire; Sexton, Maree

    2004-01-01

    Craniospinal irradiation is an important technique for the treatment of a number of paediatric malignancies. The conventional technique uses photons for all fields and does not exploit the benefits of CT and computer planning systems. The present paper describes a modification of the conventional technique in which both photons and electrons are used for the spinal field (mixed-beam technique). Computed tomography images and a planning computer are used for the selection of field junctions, electron beam energy and dosimetry. The intention of the technique is to reduce radiotherapy toxicity. A discussion of the potential benefits is presented Copyright (2004) Blackwell Publishing Asia Pty Ltd

  5. Field-In-Field Technique With Intrafractionally Modulated Junction Shifts for Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Yom, Sue S.; Frija, Erik K. C.; Mahajan, Anita; Chang, Eric; Klein, Kelli C.; Shiu, Almon; Ohrt, Jared; Woo, Shiao

    2007-01-01

    Purpose: To plan craniospinal irradiation with 'field-in-field' (FIF) homogenization in combination with daily, intrafractional modulation of the field junctions, to minimize the possibility of spinal cord overdose. Methods and Materials: Lateral cranial fields and posterior spinal fields were planned using a forward-planned, step-and-shoot FIF technique. Field junctions were automatically modulated and custom-weighted for maximal homogeneity within each treatment fraction. Dose-volume histogram analyses and film dosimetry were used to assess results. Results: Plan inhomogeneity improved with FIF. Planning with daily modulated junction shifts provided consistent dose delivery during each fraction of treatment across the junctions. Modulation minimized the impact of a 5-mm setup error at the junction. Film dosimetry confirmed that no point in the junction exceeded the anticipated dose. Conclusions: Field-in-field planning and modulated junction shifts improve the homogeneity and consistency of daily dose delivery, simplify treatment, and reduce the impact of setup errors

  6. Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

    International Nuclear Information System (INIS)

    Ricardi, Umberto; Corrias, Andrea; Einaudi, Silvia; Genitori, Lorenzo; Sandri, Alessandro; Cordero Di Montezemolo, Luca; Besenzon, Luigi; Madon, Enrico; Urgesi, Alessandro

    2001-01-01

    Purpose: Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury. Methods and Materials: The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n=20 patients) vs. hyperfractionated radiotherapy (Group B, n=12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET). Results: The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p<0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients. Conclusions: The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction

  7. SU-E-T-522: A Multi-Isocenter VMAT Technique for Cranio-Spinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Aristophanous, M; Chi, P; Tung, S; Pinnix, C; Dabaja, B [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: Develop a matching VMAT field technique and investigate planning feasibility for treating the entire central nervous system (CNS) using Cranio-Spinal Irradiation (CSI) . Methods: Two patients diagnosed with acute myeloid leukemia (AML) presented with CNS involvement, received CSI, and were included in this study. The patients were treated with the traditional CSI technique: prone position, opposing lateral brain fields, two posterior fields (upper and lower spine), and 5mm junction shifts to improve dose uniformity. The patients were retrospectively re-planned using volumetric arc therapy (VMAT). The spine and brain were contoured to create the clinical target volume (CTV) as well as normal tissues including kidneys, lung and heart for optimization. Three isocenters were used for planning: brain, upper and lower spine. The beams were allowed to overlap by approximately 10cm. Entire 360 degree rotations were used for the brain fields and posterior 120 degree arcs were used for the spine fields. The dosimetric coverage of the target between the VMAT and traditional plans was compared, as well as the dose to normal tissues. Results: Both VMAT plans achieved improved dose uniformity in the CTV (standard deviation < 2%), and reduced hot spots (<110%). Dose to the heart was reduced, with the V10 being 12.7% and 28.2%, compared to 44.6% and 50.2%, respectively, for the traditional plan. Dose to the total lung V5 increased for the VMAT plans for both patients (21.6% and 27.8% compared to 12% and 13% respectively). The results for the kidneys were mixed with the mean dose increasing for one patient and decreasing for the other . Conclusion: The efficacy of planning CSI treatments using a matching VMAT technique was demonstrated. The developed technique has the potential to improve dose uniformity to the target while at the same time reduce the risk of under or over dosing the spine.

  8. Outcome of Children With Metastatic Medulloblastoma Treated With Carboplatin During Craniospinal Radiotherapy: A Children's Oncology Group Phase I/II Study

    Science.gov (United States)

    Jakacki, Regina I.; Burger, Peter C.; Zhou, Tianni; Holmes, Emiko J.; Kocak, Mehmet; Onar, Arzu; Goldwein, Joel; Mehta, Minesh; Packer, Roger J.; Tarbell, Nancy; Fitz, Charles; Vezina, Gilbert; Hilden, Joanne; Pollack, Ian F.

    2012-01-01

    Purpose We evaluated the feasibility of administering carboplatin as a radiosensitizer during craniospinal radiation therapy (CSRT) to patients with high-risk medulloblastomas (MBs) and supratentorial primitive neuroectodermal tumors, and we report the outcome in the subset with metastatic (M+) MB. Patients and Methods After surgery, patients received 36 Gy CSRT with boosts to sites of disease. During radiation, patients received 15 to 30 doses of carboplatin (30-45 mg/m2/dose), along with vincristine (VCR) once per week for 6 weeks. Patients on regimen A received 6 months of maintenance chemotherapy (MC) with cyclophosphamide and VCR. Once the recommended phase II dose (RP2D) of carboplatin was determined, cisplatin was added to the MC (regimen B). Results In all, 161 eligible patients (median age, 8.7 years; range, 3.1 to 21.6 years) were enrolled. Myelosuppression was dose limiting and 35 mg/m2/dose × 30 was determined to be the RP2D of carboplatin. Twenty-nine (36%) of 81 patients with M+ MB had diffuse anaplasia. Four patients were taken off study within 11 months of completing radiotherapy for presumed metastatic progression and are long-term survivors following palliative chemotherapy. Excluding these four patients, 5-year overall survival ± SE and progression-free survival ± SE for M+ patients treated at the RP2D on regimen A was 82% ± 9% and 71% ± 11% versus 68% ± 10% and 59% ± 10% on regimen B (P = .36). There was no difference in survival by M stage. Anaplasia was a negative predictor of outcome. Conclusion The use of carboplatin as a radiosensitizer is a promising strategy for patients with M+ MB. Early progression should be confirmed by biopsy. PMID:22665539

  9. Effects of central-nervous-system irradiation on neuropsychologic functioning of children with acute lymphocytic leukemia

    International Nuclear Information System (INIS)

    Soni, S.S.; Marten, G.W.; Pitner, S.E.; Duenas, D.A.; Powazek, M.

    1975-01-01

    Two neuropsychologic studies were performed to determine the long-term effects of ''prophylactic'' cranial or craniospinal irradiation on the psychologic and neurologic functions of children with acute lymphocytic leukemia. In a prospective study, 34 patients with leukemia who received either craniospinal irradiation or cranial irradiation combined with intrathecal methotrexate were evaluated by standardized neurologic and psychologic examinations before and after irradiation. Their performance was compared with that of 27 controls who received irradiation to parts of the body other than the cranium. In a retrospective study, 11 patients with leukemia receiving prophylactic craniospinal irradiation and 12 controls with the disease not receiving such therapy were followed from the second year after either irradiation or the initial hematologic remission. Eighteen months after irradiation in the prospective study and four years after irradiation in the retrospective study, no noteworthy neurologic or psychologic differences were found between subjects and controls

  10. Craniospinal axis irradiation: an improved electron technique for irradiation of the spinal axis

    International Nuclear Information System (INIS)

    Chun Li; Vijayakumar, S.; Myrianthopoulos, L.C.; Kuchnir, F.T.; Muller-Runkel, R.

    1994-01-01

    The authors review dosimetric features of craniospinal axis irradiation in the areas of matching cranial and spinal fields, with reference to normal structures within the spinal field. The implications of the use of photon or electron modalities for the spinal port were evaluated. A novel method of matching the cranial photon and the spinal electron fields involving a computer-aided junction design is presented, involving moving the photon beam in three steps to degrade its penumbra to match that of the electron field. Thermoluminescent dosimetry in a Rando phantom and computed tomography-based dose-volume histogram study for an illustrative paediatric case were used to compare dose to normal structures within the spinal field. Results show that the use of electrons for the spinal field leads to better sparing of deep seated normal structures. For bone marrow, the use of a customized bolus for the spinal field results in an improved dose distribution, making electrons potentially superior to photons for radiobiological reasons. (author)

  11. Supine craniospinal irradiation in pediatric patients by proton pencil beam scanning.

    Science.gov (United States)

    Farace, Paolo; Bizzocchi, Nicola; Righetto, Roberto; Fellin, Francesco; Fracchiolla, Francesco; Lorentini, Stefano; Widesott, Lamberto; Algranati, Carlo; Rombi, Barbara; Vennarini, Sabina; Amichetti, Maurizio; Schwarz, Marco

    2017-04-01

    Proton therapy is the emerging treatment modality for craniospinal irradiation (CSI) in pediatric patients. Herein, special methods adopted for CSI at proton Therapy Center of Trento by pencil beam scanning (PBS) are comprehensively described. Twelve pediatric patients were treated by proton PBS using two/three isocenters. Special methods refer to: (i) patient positioning in supine position on immobilization devices crossed by the beams; (ii) planning field-junctions via the ancillary-beam technique; (iii) achieving lens-sparing by three-beams whole-brain-irradiation; (iv) applying a movable-snout and beam-splitting technique to reduce the lateral penumbra. Patient-specific quality assurance (QA) program was performed using two-dimensional ion chamber array and γ-analysis. Daily kilovoltage alignment was performed. PBS allowed to obtain optimal target coverage (mean D98%>98%) with reduced dose to organs-at-risk. Lens sparing was obtained (mean D1∼730cGyE). Reducing lateral penumbra decreased the dose to the kidneys (mean Dmean4cm (mean γ>95%) than at depths<4cm. The reported methods allowed to effectively perform proton PBS CSI. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Local Setup Reproducibility of the Spinal Column When Using Intensity-Modulated Radiation Therapy for Craniospinal Irradiation With Patient in Supine Position

    International Nuclear Information System (INIS)

    Stoiber, Eva Maria; Giske, Kristina; Schubert, Kai; Sterzing, Florian; Habl, Gregor; Uhl, Matthias; Herfarth, Klaus; Bendl, Rolf; Debus, Jürgen

    2011-01-01

    Purpose: To evaluate local positioning errors of the lumbar spine during fractionated intensity-modulated radiotherapy of patients treated with craniospinal irradiation and to assess the impact of rotational error correction on these uncertainties for one patient setup correction strategy. Methods and Materials: 8 patients (6 adults, 2 children) treated with helical tomotherapy for craniospinal irradiation were retrospectively chosen for this analysis. Patients were immobilized with a deep-drawn Aquaplast head mask. Additionally to daily megavoltage control computed tomography scans of the skull, once-a-week positioning of the lumbar spine was assessed. Therefore, patient setup was corrected by a target point correction, derived from a registration of the patient's skull. The residual positioning variations of the lumbar spine were evaluated applying a rigid-registration algorithm. The impact of different rotational error corrections was simulated. Results: After target point correction, residual local positioning errors of the lumbar spine varied considerably. Craniocaudal axis rotational error correction did not improve or deteriorate these translational errors, whereas simulation of a rotational error correction of the right–left and anterior–posterior axis increased these errors by a factor of 2 to 3. Conclusion: The patient fixation used allows for deformations between the patient's skull and spine. Therefore, for the setup correction strategy evaluated in this study, generous margins for the lumbar spinal target volume are needed to prevent a local geographic miss. With any applied correction strategy, it needs to be evaluated whether or not a rotational error correction is beneficial.

  13. Local Setup Reproducibility of the Spinal Column When Using Intensity-Modulated Radiation Therapy for Craniospinal Irradiation With Patient in Supine Position

    Energy Technology Data Exchange (ETDEWEB)

    Stoiber, Eva Maria, E-mail: eva.stoiber@med.uni-heidelberg.de [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany); Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Giske, Kristina [Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Schubert, Kai; Sterzing, Florian; Habl, Gregor; Uhl, Matthias; Herfarth, Klaus [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany); Bendl, Rolf [Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Medical Informatics, Heilbronn University, Heilbronn (Germany); Debus, Juergen [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany)

    2011-12-01

    Purpose: To evaluate local positioning errors of the lumbar spine during fractionated intensity-modulated radiotherapy of patients treated with craniospinal irradiation and to assess the impact of rotational error correction on these uncertainties for one patient setup correction strategy. Methods and Materials: 8 patients (6 adults, 2 children) treated with helical tomotherapy for craniospinal irradiation were retrospectively chosen for this analysis. Patients were immobilized with a deep-drawn Aquaplast head mask. Additionally to daily megavoltage control computed tomography scans of the skull, once-a-week positioning of the lumbar spine was assessed. Therefore, patient setup was corrected by a target point correction, derived from a registration of the patient's skull. The residual positioning variations of the lumbar spine were evaluated applying a rigid-registration algorithm. The impact of different rotational error corrections was simulated. Results: After target point correction, residual local positioning errors of the lumbar spine varied considerably. Craniocaudal axis rotational error correction did not improve or deteriorate these translational errors, whereas simulation of a rotational error correction of the right-left and anterior-posterior axis increased these errors by a factor of 2 to 3. Conclusion: The patient fixation used allows for deformations between the patient's skull and spine. Therefore, for the setup correction strategy evaluated in this study, generous margins for the lumbar spinal target volume are needed to prevent a local geographic miss. With any applied correction strategy, it needs to be evaluated whether or not a rotational error correction is beneficial.

  14. Comparison of a new noncoplanar intensity-modulated radiation therapy technique for craniospinal irradiation with 3 coplanar techniques

    DEFF Research Database (Denmark)

    Hansen, Anders T; Lukacova, Slavka; Lassen-Ramshad, Yasmin A.

    2015-01-01

    When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar...... patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanar volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique...... substantially reduced the mean dose to organs at risk compared with the standard radiation technique. The 2 other coplanar techniques also reduced the mean dose to some of the critical organs. However, this reduction was not as substantial as the reduction obtained by the noncoplanar technique. Furthermore...

  15. Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning.

    Science.gov (United States)

    Myers, Pamela A; Mavroidis, Panayiotis; Papanikolaou, Nikos; Stathakis, Sotirios

    2014-09-08

    Currently, radiotherapy treatment plan acceptance is based primarily on dosimetric performance measures. However, use of radiobiological analysis to assess benefit in terms of tumor control and harm in terms of injury to normal tissues can be advantageous. For pediatric craniospinal axis irradiation (CSI) patients, in particular, knowing the technique that will optimize the probabilities of benefit versus injury can lead to better long-term outcomes. Twenty-four CSI pediatric patients (median age 10) were retrospectively planned with three techniques: three-dimensional conformal radiation therapy (3D CRT), volumetric-modulated arc therapy (VMAT), and helical tomotherapy (HT). VMAT plans consisted of one superior and one inferior full arc, and tomotherapy plans were created using a 5.02cm field width and helical pitch of 0.287. Each plan was normalized to 95% of target volume (whole brain and spinal cord) receiving prescription dose 23.4Gy in 13 fractions. Using an in-house MATLAB code and DVH data from each plan, the three techniques were evaluated based on biologically effective uniform dose (D=), the complication-free tumor control probability (P+), and the width of the therapeutically beneficial range. Overall, 3D CRT and VMAT plans had similar values of D= (24.1 and 24.2 Gy), while HT had a D= slightly lower (23.6 Gy). The average values of the P+ index were 64.6, 67.4, and 56.6% for 3D CRT, VMAT, and HT plans, respectively, with the VMAT plans having a statistically significant increase in P+. Optimal values of D= were 28.4, 33.0, and 31.9 Gy for 3D CRT, VMAT, and HT plans, respectively. Although P+ values that correspond to the initial dose prescription were lower for HT, after optimizing the D= prescription level, the optimal P+ became 94.1, 99.5, and 99.6% for 3D CRT, VMAT, and HT, respectively, with the VMAT and HT plans having statistically significant increases in P+. If the optimal dose level is prescribed using a radiobiological evaluation method, as

  16. Survival of very young children with medulloblastoma (primitive neuroectodermal tumor of the posterior fossa) treated with craniospinal irradiation

    International Nuclear Information System (INIS)

    Saran, Frank H.; Driever, Pablo Herniz; Thilmann, Christoph; Mose, Stephan; Wilson, Paula; Sharpe, Geoff; Adamietz, Irenaeus A.; Boettcher, Heinz D.

    1998-01-01

    Purpose: Very young children with medulloblastoma are considered to have a worse prognosis than older children. As radiotherapy remains an important part of the treatment, the adverse prognosis could be due to inadequate radiation treatment rather than biological factors. We analyzed the published literature to examine the impact of radiotherapy on survival in this group. Methods and Materials: A Medline search was performed and we reviewed studies of treatment of medulloblastoma where radiotherapy was delivered using megavoltage equipment and the minimum follow-up allowed the calculation of 5-year survival rates. Results: Thirty-nine studies were published between 1979 and 1996 with a treatment including craniospinal irradiation and boost to the posterior fossa. Eleven studies comprising 1366 patients analyzed survival by age at diagnosis. Eight of 11 studies showed a worse 5-year survival for the younger patient group which reached statistical significance in two. There is also a suggestion of a higher proportion of children with metastatic disease at presentation in the very young age group. The usual policy in younger children was to give a lower dose of radiotherapy to the craniospinal axis (CSA) and posterior fossa (PF) with reduction of dose in the range of 15 to 25% compared to standard treatment. As dose reduction to the posterior fossa is associated with worse survival and local recurrence is the predominant site of failure, the major determinant of worse survival in very young children with medulloblastoma may be suboptimal radiotherapy. Protocols including postoperative chemotherapy with delayed, omitted, or only local tumor irradiation do not reach survival rates of protocols with standard radiotherapy, also suggesting a continued importance for irradiation. Conclusion: Very young children with medulloblastoma have a worse prognosis than older children. Inadequate radiation dose and technique to the primary tumor region may be a major contributing

  17. Craniospinal treatment with IMRT multi-isocentric and image-guided linear accelerator based on Gantry; Tratamiento craneoespinal multi-isocentrico con IMRT y guiado por imagen en acelerador lineal basado en Gantry

    Energy Technology Data Exchange (ETDEWEB)

    Sanz Beltran, M.; Caballero Perea, B.; Rodriguez Rodriguez, C.; Arminio Diaz, E.; Lopez Fernandez, A.; Gomez Fervienza, J. R.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.; Gomez Fervienza, J. r.; Crespo Diez, P.; Cantarero Valenzuela, N.; Alvarez Sanchez, M.; Martin Martin, G.

    2011-07-01

    The objective is the realization of craniospinal treatment with a linear accelerator equipped with gantry based on MLC, carbon fiber table and Image Guided capability. The great length of treatment (patient l, 80m in height) was a great difficulty for want of full length of the longitudinal movement of the table to adequately cover the PTV, plus free metallic screws fastening the head of the table extender preventing further incidents.

  18. Proton Beam Craniospinal Irradiation Reduces Acute Toxicity for Adults With Medulloblastoma

    International Nuclear Information System (INIS)

    Brown, Aaron P.; Barney, Christian L.; Grosshans, David R.; McAleer, Mary Frances; Groot, John F. de; Puduvalli, Vinay K.; Tucker, Susan L.; Crawford, Cody N.; Khan, Meena; Khatua, Soumen; Gilbert, Mark R.; Brown, Paul D.; Mahajan, Anita

    2013-01-01

    Purpose: Efficacy and acute toxicity of proton craniospinal irradiation (p-CSI) were compared with conventional photon CSI (x-CSI) for adults with medulloblastoma. Methods and Materials: Forty adult medulloblastoma patients treated with x-CSI (n=21) or p-CSI (n=19) at the University of Texas MD Anderson Cancer Center from 2003 to 2011 were retrospectively reviewed. Median CSI and total doses were 30.6 and 54 Gy, respectively. The median follow-up was 57 months (range 4-103) for x-CSI patients and 26 months (range 11-63) for p-CSI. Results: p-CSI patients lost less weight than x-CSI patients (1.2% vs 5.8%; P=.004), and less p-CSI patients had >5% weight loss compared with x-CSI (16% vs 64%; P=.004). p-CSI patients experienced less grade 2 nausea and vomiting compared with x-CSI (26% vs 71%; P=.004). Patients treated with x-CSI were more likely to have medical management of esophagitis than p-CSI patients (57% vs 5%, P<.001). p-CSI patients had a smaller reduction in peripheral white blood cells, hemoglobin, and platelets compared with x-CSI (white blood cells 46% vs 55%, P=.04; hemoglobin 88% vs 97%, P=.009; platelets 48% vs 65%, P=.05). Mean vertebral doses were significantly associated with reductions in blood counts. Conclusions: This report is the first analysis of clinical outcomes for adult medulloblastoma patients treated with p-CSI. Patients treated with p-CSI experienced less treatment-related morbidity including fewer acute gastrointestinal and hematologic toxicities

  19. Comparison of supine and prone craniospinal irradiation in children with medulloblastoma.

    Science.gov (United States)

    Verma, Jonathan; Mazloom, Ali; Teh, Bin S; South, Michael; Butler, E Brian; Paulino, Arnold C

    2015-01-01

    To compare port film rejection and treatment outcome according to craniospinal irradiation (CSI) position for medulloblastoma. We retrospectively searched for patients ≤19 years treated with CSI for medulloblastoma at 1 department. We collected the following data: age; sex; risk group; need for general anesthesia; radiation therapy (RT) dose and fractionation; and the acceptance or rejection of weekly port films during treatment. We also collected data on outcomes, including neuraxis recurrence and possible complications such as myelitis. Of 46 children identified, 23 were treated prone (median age, 8.1 years) and 23 supine (median age, 7.2 years). High-risk disease was seen in 26% of prone and 35% of supine patients (P = .25). There was no difference in use of general anesthesia between those treated prone versus supine (57% vs 61%). The rejection rate of cranial port films in the prone position was 35%, which was significantly higher than the rate of 8% in patients treated supine (P < .0001). The 5-year progression-free (P = .37) and overall survival (P = .18) rates were 62% and 67% for prone and 76% and 84% for supine patients. There were no isolated junctional failures or radiation myelitis in either CSI position. The supine position for CSI was found to have similar survival outcomes compared with the prone position. A higher proportion of rejected cranial port films was seen in children treated in the prone position. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  20. Craniospinal irradiation in patients with central nervous system tumors

    International Nuclear Information System (INIS)

    Skowronska-Gardas, A.; Chojnacka, M.; Pedziwiatr, K.; Morawska-Kaczynska, M.; Dabrowski, R.; Semaniak, A.

    2000-01-01

    The paper presents the experience of the Department of Radiotherapy (Cancer Centre in Warsaw) in conformal craniospinal radiotherapy (CSR) with CT-based 3D treatment planning. The entire brain (including the cribrum and the meninges) and spinal cord are rendered on CT scans as the clinical target volume (CTV), together with the primary tumour bed with 1.5-2 cm margin as CTV for boost irradiation. The caudal border of the CTV is determined basing on MRI. According to our treatment protocol the entire brain and the upper part of the spinal cord to the level of C3-C4 are treated with two isocentric lateral 6 MV photon fields, with collimator rotation and customised blocks. Spinal cord irradiation is usually performed with posterior 18-21 MeV electron or, rarely, with 4-6 MeV photon fields. Tissue compensators (boluses) are used often. The junctions between the fields are moved at least 1 cm after half of the total dose has been delivered. The primary tumour bed with its margin is boosted with two opposed, two oblique or three noncoplanar 15 MeV photon beams with customised blocks. High dose uniformity all over the target (SD <2%) and acceptable dose levels are achieved in vital structures (pituitary, thyroid gland, cochlea, eyes). For instance the dose to the lens usually does not exceed 15%. Dose evaluation revealed that the average doses to the heart and the thyroid gland are diminished at least by half when the spinal cord is irradiated with electrons, than in the case of photons. CT-based 3D treatment planning of CSR provides the potential to visualise and irradiate the target itself, while avoiding so-called ''geographical'' errors and decreasing the risk of tumour relapse. Irradiation of the spinal cord with electrons decreases the risk of late effects, above all that of hypothyroidism. Between 1.01.1998 and 31.12.1999, 40 children (24 boys and 16 girls; aged between 3 and 15 years; median age 7 years) had undergone CSR according to the described method. (author)

  1. CT simulation technique for craniospinal irradiation in supine position

    International Nuclear Information System (INIS)

    Lee, Suk; Kim, Yong Bae; Chu, Sung Sil; Suh, Chang Ok; Kwon, Soo Il

    2002-01-01

    In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetric image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was performed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. CSI in the supine position was successfully performed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The difference between the DRRs and the portal films were less than 3 mm in the vertebral contour. CSI in the supine position is feasible in patients who cannot lie on

  2. CT simulation technique for craniospinal irradiation in supine position

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Suk; Kim, Yong Bae; Chu, Sung Sil; Suh, Chang Ok [Yonsei Cancer Center, College of Medicine, Yonsei University, Seoul (Korea, Republic of); Kwon, Soo Il [Kyonggi University, Seoul (Korea, Republic of)

    2002-06-15

    In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetric image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was performed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. CSI in the supine position was successfully performed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The difference between the DRRs and the portal films were less than 3 mm in the vertebral contour. CSI in the supine position is feasible in patients who cannot

  3. Technical study of craniospinal irradiation in pediatric patients with patient position and field matching

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Masanori; Ise, Toshihide; Umezu, Mikio [Kangawa Children' s Medical Center, Yokohama (Japan); Hioki, Minoru

    2000-05-01

    Craniospinal irradiation (CSI) in leukemia and medulloblastoma patients is usually a three-field technique that involves parallel-opposed lateral cranial fields adjacent and orthogonal to a posterior spinal field. Since sedation is often necessary for pediatric patients, the supine position is more favorable than the prone position for respiratory monitoring. We practiced CSI in the supine position in one case of leukemia and three cases of medulloblastoma. Each location of the isocenter was determined by moving the couch to fit the center of the CSI on the basis of incisura intertragica. The angles of collimator rotation and couch rotation were calculated according to each treatment field size. The junction was also moved 2 cm day by day during the course of treatment so that over- and underdose at the junction would be prevented. The supine position did not allow us to visually confirm the proper junction between the lateral cranial fields and the spinal field. However, we succeeded in practicing complete conjunction between the fields by proper collimator and couch rotations on the assessment of the film-dose method. CSI in the supine position is naturally comfortable for pediatric patients and seems effective in pediatric treatments, which often require respiratory monitoring for sedation. (author)

  4. Bowel sparing in pediatric cranio-spinal radiotherapy: a comparison of combined electron and photon and helical TomoTherapy techniques to a standard photon method

    International Nuclear Information System (INIS)

    Harron, Elizabeth; Lewis, Joanne

    2012-01-01

    The aim of this study was to compare the dose to organs at risk (OARs) from different craniospinal radiotherapy treatment approaches available at the Northern Centre for Cancer Care (NCCC), with a particular emphasis on sparing the bowel. Method: Treatment plans were produced for a pediatric medulloblastoma patient with inflammatory bowel disease using 3D conformal 6-MV photons (3DCP), combined 3D 6-MV photons and 18-MeV electrons (3DPE), and helical photon TomoTherapy (HT). The 3DPE plan was a modification of the standard 3DCP technique, using electrons to treat the spine inferior to the level of the diaphragm. The plans were compared in terms of the dose-volume data to OARs and the nontumor integral dose. Results: The 3DPE plan was found to give the lowest dose to the bowel and the lowest nontumor integral dose of the 3 techniques. However, the coverage of the spine planning target volume (PTV) was least homogeneous using this technique, with only 74.6% of the PTV covered by 95% of the prescribed dose. HT was able to achieve the best coverage of the PTVs (99.0% of the whole-brain PTV and 93.1% of the spine PTV received 95% of the prescribed dose), but delivered a significantly higher integral dose. HT was able to spare the heart, thyroid, and eyes better than the linac-based techniques, but other OARs received a higher dose. Conclusions: Use of electrons was the best method for reducing the dose to the bowel and the integral dose, at the expense of compromised spine PTV coverage. For some patients, HT may be a viable method of improving dose homogeneity and reducing selected OAR doses.

  5. Radiation therapy for intracranial ependymomas: impact of age on outcome

    International Nuclear Information System (INIS)

    Pham, Houng T.; Sneed, Penny K.; Wara, William M.; Edwards, Michael S.; Wilson, Charles B.; Larson, David A.

    1997-01-01

    Purpose: The records of patients with intracranial ependymoma who received radiation therapy at UCSF were reviewed retrospectively to evaluate the impact of Karnofsky performance status (KPS), age, histology, and treatment on outcome. Materials and Methods: Between 1978 and 1996, 45 patients with intracranial ependymoma received postoperative radiation therapy. Overall survival (OS) and progression free survival (PFS) were calculated from the date of diagnosis. Median follow up for surviving patients was 72 months. Ages ranged from 4 months to 56 years, with a median of 8 years. The tumor was infratentorial in 35 and supratentorial in 10. All patients had either biopsy (3), subtotal resection (30), or gross total resection (12). There were 29 low grade and 16 anaplastic ependymomas. Thirty-seven patients received standard fractionation to a median dose of 54 Gy. Eight patients received hyperfractionation at 1.0 Gy BID to a median dose of 72 Gy. Thirty-eight patients had partial brain irradiation and seven had craniospinal irradiation. Twenty-three patients received adjuvant chemotherapy. For the infants ≤ 3 years old (n=12), all but one had a subtotal resection and most received chemotherapy prior to radiation therapy. Seven infants received radiation therapy at the time of disease progression and five had radiation therapy prior to progression. Most of the patients > 3 years old were irradiated prior to progression. Results: The five-year actuarial OS and PFS were 65% and 46% for the whole group. Histology and treatment factors such as extent of resection, hyperfractionation, and adjuvant chemotherapy did not significantly affect outcome. Overall, (25(45)) patients had disease progression. Only two patients failed in the brain outside the primary site. Six patients developed leptomeningeal spread (four concurrent with local failure and two subsequent to local failure). Five-year OS for patients ≤ 3 years old was 21% versus 80% for patients > 3 years old (p=0

  6. Craniospinal radiotherapy in children: Electron- or photon-based technique of spinal irradiation

    International Nuclear Information System (INIS)

    Chojnacka, M.; Skowronska-Gardas, A.; Pedziwiatr, K.; Morawska-Kaczynska, M.; Zygmuntowicz-Pietka, A.; Semaniak, A.

    2010-01-01

    Background: The prone position and electron-based technique for craniospinal irradiation (CSI) have been standard in our department for many years. But this immobilization is difficult for the anaesthesiologist to gain airway access. The increasing number of children treated under anaesthesia led us to reconsider our technique. Aim: The purpose of this study is to report our new photon-based technique for CSI which could be applied in both the supine and the prone position and to compare this technique with our electron-based technique. Materials and methods: Between November 2007 and May 2008, 11 children with brain tumours were treated in the prone position with CSI. For 9 patients two treatment plans were created: the first one using photons and the second one using electron beams for spinal irradiation. We prepared seven 3D-conformal photon plans and four forward planned segmented field plans. We compared 20 treatment plans in terms of target dose homogeneity and sparing of organs at risk. Results: In segmented field plans better dose homogeneity in the thecal sac volume was achieved than in electron-based plans. Regarding doses in organs at risk, in photon-based plans we obtained a lower dose in the thyroid but a higher one in the heart and liver. Conclusions: Our technique can be applied in both the supine and prone position and it seems to be more feasible and precise than the electron technique. However, more homogeneous target coverage and higher precision of dose delivery for photons are obtained at the cost of slightly higher doses to the heart and liver. (authors)

  7. Dosimetric comparison between proton and photon beams in the moving gap region in cranio-spinal irradiation (CSI)

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chee-Wai; Das, Indra J.; Zhao, Li; Wolanski, Mark; Johnstone, Peter A.S.; Buchsbaum, Jeffrey C. [IU Health Proton Therapy Center, Bloomington (United States); Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States)], e-mail: ccheng1@iuhealth.org; Srivastava, Shiv P. [Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States); Dept. of Radiation Oncology, Reid Hospital, Richmond (United States); Simmons, Joseph [IU Health Proton Therapy Center, Bloomington (United States)

    2013-04-15

    Purpose: To investigate the moving gap region dosimetry in proton beam cranio-spinal irradiation (CSI) to provide optimal dose uniformity across the treatment volume. Material and methods: Proton beams of ranges 11.6 cm and 16 cm are used for the spine and the brain fields, respectively. Beam profiles for a 30 cm snout are first matched at the 50% level (hot match) on the computer. Feathering is simulated by shifting the dose profiles by a known distance two successive times to simulate a 2 x feathering scheme. The process is repeated for 2 mm and 4 mm gaps. Similar procedures are used to determine the dose profiles in the moving gap for a series of gap widths, 0-10 mm, and feathering step sizes, 4-10 mm, for a Varian iX 6MV beam. The proton and photon dose profiles in the moving gap region are compared. Results: The dose profiles in the moving gap exhibit valleys and peaks in both proton and photon beam CSI. The dose in the moving gap for protons is around 100% or higher for 0 mm gap, for both 5 and 10 mm feathering step sizes. When the field gap is comparable or larger than the penumbra, dose minima as low as 66% is obtained. The dosimetric characteristics for 6 MV photon beams can be made similar to those of the protons by appropriately combining gap width and feathering step size. Conclusion: The dose in the moving gap region is determined by the lateral penumbras, the width of the gap and the feathering step size. The dose decreases with increasing gap width or decreasing feathering step size. The dosimetric characteristics are similar for photon and proton beams. However, proton CSI has virtually no exit dose and is beneficial for pediatric patients, whereas with photon beams the whole lung and abdomen receive non-negligible exit dose.

  8. Intensity Modulated Proton Therapy for Craniospinal Irradiation: Organ-at-Risk Exposure and a Low-Gradient Junctioning Technique

    International Nuclear Information System (INIS)

    Stoker, Joshua B.; Grant, Jonathan; Zhu, X. Ronald; Pidikiti, Rajesh; Mahajan, Anita; Grosshans, David R.

    2014-01-01

    Purpose: To compare field junction robustness and sparing of organs at risk (OARs) during craniospinal irradiation (CSI) using intensity modulated proton therapy (IMPT) to conventional passively scattered proton therapy (PSPT). Methods and Materials: Ten patients, 5 adult and 5 pediatric patients, previously treated with PSPT-based CSI were selected for comparison. Anterior oblique cranial fields, using a superior couch rotation, and posterior spinal fields were used for IMPT planning. To facilitate low-gradient field junctioning along the spine, the inverse-planning IMPT technique was divided into 3 stages. Dose indices describing target coverage and normal tissue dose, in silico error modeling, and film dosimetry were used to assess plan quality. Results: Field junction robustness along the spine was improved using the staged IMPT planning technique, reducing the worst case impact of a 4-mm setup error from 25% in PSPT to <5% of prescription dose. This was verified by film dosimetry for clinical delivery. Exclusive of thyroid dose in adult patients, IMPT plans demonstrated sparing of organs at risk as good or better than PSPT. Coverage of the cribriform plate for pediatric (V95% [percentage of volume of the target receiving at least 95% of the prescribed dose]; 87 ± 11 vs 92 ± 7) and adult (V95%; 94 ± 7 vs 100 ± 1) patients and the clinical target in pediatric (V95%; 98 ± 2 vs 100 ± 1) and adult (V95%; 100 ± 1 vs 100 ± 1) patients for PSPT and IMPT plans, respectively, were comparable or improved. For adult patients, IMPT target dose inhomogeneity was increased, as determined by heterogeneity index (HI) and inhomogeneity coefficient (IC). IMPT lowered maximum spinal cord dose, improved spinal dose homogeneity, and reduced exposure to other OARs. Conclusions: IMPT has the potential to improve CSI plan quality and the homogeneity of intrafractional dose at match lines. The IMPT approach developed may also simplify treatments and reduce

  9. A review of dosimetric and toxicity modeling of proton versus photon craniospinal irradiation for pediatrics medulloblastoma.

    Science.gov (United States)

    Ho, Evangeline S Q; Barrett, Sarah A; Mullaney, Laura M

    2017-08-01

    Craniospinal irradiation (CSI) is the standard radiation therapy treatment for medulloblastoma. Conventional CSI photon therapy (Photon-CSI) delivers significant dose to surrounding normal tissue (NT). Research into pediatric CSI with proton therapy (Proton-CSI) has increased, with the aim of exploiting the potential to reduce NT dose and associated post-treatment complications. This review aims to compare treatment outcomes of pediatric medulloblastoma patients between Proton- and Photon-CSI treatments. A search and review of studies published between 1990 and 2016 comparing pediatric (2-18 years) medulloblastoma Proton- and Photon-CSI in three aspects - normal organ sparing and target coverage; normal organ dysfunction and second malignancy risks - was completed. Fifteen studies were selected for review and the results were directly compared. Proton-CSI reported improved out-of-field organ sparing while target coverage improvements were inconsistent. Normal organ dysfunction risks were predicted to be lower following Proton-CSI. Secondary malignancy risks (SMRs) were generally lower with Proton-CSI based on several different risk models. Proton-CSI conferred better treatment outcomes than Photon-CSI for pediatric medulloblastoma patients. This review serves to compare the current literature in the absence of long-term data from prospective studies.

  10. SU-E-T-226: Junction Free Craniospinal Irradiation in Linear Accelerator Using Volumetric Modulated Arc Therapy : A Novel Technique Using Dose Tapering

    International Nuclear Information System (INIS)

    Sarkar, B; Roy, S; Paul, S; Munshi, A; Roy, Shilpi; Jassal, K; Ganesh, T; Mohanti, BK

    2014-01-01

    Purpose: Spatially separated fields are required for craniospinal irradiation due to field size limitation in linear accelerator. Field junction shits are conventionally done to avoid hot or cold spots. Our study was aimed to demonstrate the feasibility of junction free irradiation plan of craniospinal irradiation (CSI) for Meduloblastoma cases treated in linear accelerator using Volumetric modulated arc therapy (VMAT) technique. Methods: VMAT was planned using multiple isocenters in Monaco V 3.3.0 and delivered in Elekta Synergy linear accelerator. A full arc brain and 40° posterior arc spine fields were planned using two isocentre for short (<1.3 meter height ) and 3 isocentres for taller patients. Unrestricted jaw movement was used in superior-inferior direction. Prescribed dose to PTV was achieved by partial contribution from adjacent beams. A very low dose gradient was generated to taper the isodoses over a long length (>10 cm) at the conventional field junction. Results: In this primary study five patients were planned and three patients were delivered using this novel technique. As the dose contribution from the adjacent beams were varied (gradient) to create a complete dose distribution, therefore there is no specific junction exists in the plan. The junction were extended from 10–14 cm depending on treatment plan. Dose gradient were 9.6±2.3% per cm for brain and 7.9±1.7 % per cm for spine field respectively. Dose delivery error due to positional inaccuracy was calculated for brain and spine field for ±1mm, ±2mm, ±3mm and ±5 mm were 1%–0.8%, 2%–1.6%, 2.8%–2.4% and 4.3%–4% respectively. Conclusion: Dose tapering in junction free CSI do not require a junction shift. Therefore daily imaging for all the field is also not essential. Due to inverse planning dose to organ at risk like thyroid kidney, heart and testis can be reduced significantly. VMAT gives a quicker delivery than Step and shoot or dynamic IMRT

  11. SU-E-T-226: Junction Free Craniospinal Irradiation in Linear Accelerator Using Volumetric Modulated Arc Therapy : A Novel Technique Using Dose Tapering

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, B; Roy, S; Paul, S; Munshi, A; Roy, Shilpi; Jassal, K; Ganesh, T; Mohanti, BK [Fortis Memorial Research Institute, Gurgaon (India)

    2014-06-01

    Purpose: Spatially separated fields are required for craniospinal irradiation due to field size limitation in linear accelerator. Field junction shits are conventionally done to avoid hot or cold spots. Our study was aimed to demonstrate the feasibility of junction free irradiation plan of craniospinal irradiation (CSI) for Meduloblastoma cases treated in linear accelerator using Volumetric modulated arc therapy (VMAT) technique. Methods: VMAT was planned using multiple isocenters in Monaco V 3.3.0 and delivered in Elekta Synergy linear accelerator. A full arc brain and 40° posterior arc spine fields were planned using two isocentre for short (<1.3 meter height ) and 3 isocentres for taller patients. Unrestricted jaw movement was used in superior-inferior direction. Prescribed dose to PTV was achieved by partial contribution from adjacent beams. A very low dose gradient was generated to taper the isodoses over a long length (>10 cm) at the conventional field junction. Results: In this primary study five patients were planned and three patients were delivered using this novel technique. As the dose contribution from the adjacent beams were varied (gradient) to create a complete dose distribution, therefore there is no specific junction exists in the plan. The junction were extended from 10–14 cm depending on treatment plan. Dose gradient were 9.6±2.3% per cm for brain and 7.9±1.7 % per cm for spine field respectively. Dose delivery error due to positional inaccuracy was calculated for brain and spine field for ±1mm, ±2mm, ±3mm and ±5 mm were 1%–0.8%, 2%–1.6%, 2.8%–2.4% and 4.3%–4% respectively. Conclusion: Dose tapering in junction free CSI do not require a junction shift. Therefore daily imaging for all the field is also not essential. Due to inverse planning dose to organ at risk like thyroid kidney, heart and testis can be reduced significantly. VMAT gives a quicker delivery than Step and shoot or dynamic IMRT.

  12. SU-F-T-504: Non-Divergent Planning Method for Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, N; Bogue, J; Parsai, E [University of Toledo Medical Center, Toledo, OH (United States)

    2016-06-15

    Purpose: Traditional Craniospinal Irradiation (CSI) planning techniques require careful field placement to allow optimal divergence and field overlap at depth, and measurement of skin gap. The result of this is a necessary field overlap resulting in dose heterogeneity in the spinal canal. A novel, nondivergent field matching method has been developed to allow simple treatment planning and delivery without the need to measure skin gap. Methods: The CSI patient was simulated in the prone, and a plan was developed. Bilateral cranial fields were designed with couch and collimator rotation to eliminate divergence with the upper spine field and minimize anterior divergence into the lenses. Spinal posterior-to-anterior fields were designed with the couch rotated to 90 degrees to allow gantry rotation to eliminate divergence at the match line, and the collimator rotated to 90 degrees to allow appropriate field blocking with the MLCs. A match line for the two spinal fields was placed and the gantry rotated to equal angles in opposite directions about the match line. Jaw positions were then defined to allow 1mm overlap at the match line to avoid cold spots. A traditional CSI plan was generated using diverging spinal fields, and a comparison between the two techniques was generated. Results: The non-divergent treatment plan was able to deliver a highly uniform dose to the spinal cord with a cold spot of only 95% and maximum point dose of 115.8%, as compared to traditional plan cold spots of 87% and hot spots of 132% of the prescription dose. Conclusion: A non-divergent method for planning CSI patients has been developed and clinically implemented. Planning requires some geometric manipulation in order to achieve an adequate dose distribution, however, it can help to manage cold spots and simplify the shifts needed between spinal fields.

  13. SU-F-T-504: Non-Divergent Planning Method for Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Sperling, N; Bogue, J; Parsai, E

    2016-01-01

    Purpose: Traditional Craniospinal Irradiation (CSI) planning techniques require careful field placement to allow optimal divergence and field overlap at depth, and measurement of skin gap. The result of this is a necessary field overlap resulting in dose heterogeneity in the spinal canal. A novel, nondivergent field matching method has been developed to allow simple treatment planning and delivery without the need to measure skin gap. Methods: The CSI patient was simulated in the prone, and a plan was developed. Bilateral cranial fields were designed with couch and collimator rotation to eliminate divergence with the upper spine field and minimize anterior divergence into the lenses. Spinal posterior-to-anterior fields were designed with the couch rotated to 90 degrees to allow gantry rotation to eliminate divergence at the match line, and the collimator rotated to 90 degrees to allow appropriate field blocking with the MLCs. A match line for the two spinal fields was placed and the gantry rotated to equal angles in opposite directions about the match line. Jaw positions were then defined to allow 1mm overlap at the match line to avoid cold spots. A traditional CSI plan was generated using diverging spinal fields, and a comparison between the two techniques was generated. Results: The non-divergent treatment plan was able to deliver a highly uniform dose to the spinal cord with a cold spot of only 95% and maximum point dose of 115.8%, as compared to traditional plan cold spots of 87% and hot spots of 132% of the prescription dose. Conclusion: A non-divergent method for planning CSI patients has been developed and clinically implemented. Planning requires some geometric manipulation in order to achieve an adequate dose distribution, however, it can help to manage cold spots and simplify the shifts needed between spinal fields.

  14. Cognitive Behavioral Therapy for Psychosis (CBT-p) Delivered in a Community Mental Health Setting: A Case Comparison of Clients Receiving CBT Informed Strategies by Case Managers Prior to Therapy.

    Science.gov (United States)

    Sivec, Harry J; Montesano, Vicki L; Skubby, David; Knepp, Kristen A; Munetz, Mark R

    2017-02-01

    This exploratory case comparison examines the influence of case management activities on engagement and progress in psychotherapy for clients with schizophrenia. Six clients were recruited to participate in ten sessions of Cognitive Behavioral Therapy for psychosis (CBT-p). Three clients who had received Cognitive Behavioral techniques for psychosis (CBt-p, a low-intensity case management intervention) prior to receiving therapy were selected from referrals. A comparison group of three clients who had received standard case management services was selected from referrals. Cases within and across groups were compared on outcome measures and observations from case review were offered to inform future research. Delivering CBT-p services on a continuum from low- to high-intensity is discussed.

  15. Non-pineal supratentorial primitive neuro-ectodermal tumors (sPNET) in teenagers and young adults: Time to reconsider cisplatin based chemotherapy after cranio-spinal irradiation?

    Science.gov (United States)

    Biswas, Swethajit; Burke, Amos; Cherian, Sheen; Williams, Denise; Nicholson, James; Horan, Gail; Jefferies, Sarah; Williams, Michael; Earl, Helena M; Burnet, Neil G; Hatcher, Helen

    2009-07-01

    Supratentorial PNET (sPNET) are rare CNS tumors of embryonal origin arising in children and adults. The treatment of sPNET for all age groups at our cancer center has been based on the management of medulloblastoma (MB), involving neurosurgical debulking followed by cranio-spinal irradiation (CSI) and systemic chemotherapy. Medical records were reviewed to gather demographic and clinical data about all embryonal CNS tumors in children and adults from 2001 to 2007. Tumor pathology, clinical management and survival data were also assessed, particularly as regards those patients who received the Packer chemotherapy regimen for either sPNET or MB. Eleven patients (five children and six adults) were identified with non-pineal sPNET, three children with pineal sPNET, and 19 patients (18 children and 1 adult) with MB. There was no difference in overall survival (OS) rates between pediatric and adult sPNET. When all sPNET were compared to all MB, 5-year OS was 14% versus 73%, respectively, but was only 9% for non-pineal sPNET. When only considering those patients treated with the Packer chemotherapy regimen, the 5-year OS was 12% for sPNET versus 79% for MB. This retrospective study demonstrates that non-pineal sPNET are clinically distinct from MB and are resistant to the Packer chemotherapy regimen. We suggest that it is time to reconsider the use of this regimen in teenage and young adult non-pineal sPNET and to investigate the utility of alternative approaches. (c) 2009 Wiley-Liss, Inc.

  16. Universal field matching in craniospinal irradiation by a background-dose gradient-optimized method.

    Science.gov (United States)

    Traneus, Erik; Bizzocchi, Nicola; Fellin, Francesco; Rombi, Barbara; Farace, Paolo

    2018-01-01

    The gradient-optimized methods are overcoming the traditional feathering methods to plan field junctions in craniospinal irradiation. In this note, a new gradient-optimized technique, based on the use of a background dose, is described. Treatment planning was performed by RayStation (RaySearch Laboratories, Stockholm, Sweden) on the CT scans of a pediatric patient. Both proton (by pencil beam scanning) and photon (by volumetric modulated arc therapy) treatments were planned with three isocenters. An 'in silico' ideal background dose was created first to cover the upper-spinal target and to produce a perfect dose gradient along the upper and lower junction regions. Using it as background, the cranial and the lower-spinal beams were planned by inverse optimization to obtain dose coverage of their relevant targets and of the junction volumes. Finally, the upper-spinal beam was inversely planned after removal of the background dose and with the previously optimized beams switched on. In both proton and photon plans, the optimized cranial and the lower-spinal beams produced a perfect linear gradient in the junction regions, complementary to that produced by the optimized upper-spinal beam. The final dose distributions showed a homogeneous coverage of the targets. Our simple technique allowed to obtain high-quality gradients in the junction region. Such technique universally works for photons as well as protons and could be applicable to the TPSs that allow to manage a background dose. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  17. Retrospective multi-institutional study of radiotherapy for intracranial non-germinomatous germ cell tumors

    International Nuclear Information System (INIS)

    Aoyama, H.; Shirato, H.; Miyasaka, K.; Yoshida, H.; Hareyama, M.; Nishio, M.; Yanagisawa, T.; Kakuto, Y.; Watarai, J.; Inakoshi, H.

    1998-01-01

    The treatment outcome of 24 patients with pathologically-proven non-germinomatous germ cell tumor was retrospectively investigated to determine the effectiveness of radiotherapy. The patients were divided into three groups as follows: group 1, five patients with mature teratoma with or without germinoma; group 2, six patients with immature teratoma with or without germinoma; group 3, 13 patients with other highly malignant tumors. The overall actuarial survival and relapse-free rates at 5 years were 82% and 59%, respectively, with a median follow-up period of 62 months. The actuarial relapse-free rate at 5 years was 100% for group 1, 63% for group 2 and 44% for group 3. There was no difference in the relapse-free rates between total resection and partial resection. Usage of chemotherapy was adversely related to survival probably due to selection bias. No local failure was observed with 10 Gy or more for group 1, 40 Gy or more for group 2 and 54 Gy or more for group 3. In groups 1 and 2, there was no spinal relapses without craniospinal irradiation. In group 3, three of eight patients who did not receive craniospinal irradiation and none of five patients who received craniospinal irradiation experienced spinal relapse. In conclusion, highly malignant GCTs show a high incidence of spinal metastasis and craniospinal irradiation may reduce the risk of spinal metastasis. Radiation dose and volume are to be determined according to the histopathological aggressiveness. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. A simple planning technique of craniospinal irradiation in the eclipse treatment planning system

    Directory of Open Access Journals (Sweden)

    Hemalatha Athiyaman

    2014-01-01

    Full Text Available A new planning method for Craniospinal Irradiation by Eclipse treatment planning system using Field alignment, Field-in-Field technique was developed. Advantage of this planning method was also studied retrospectively for previously treated five patients of medulloblastoma with variable spine length. Plan consists of half beam blocked parallel opposed cranium, and a single posterior cervicospine field was created by sharing the same isocenter, which obviates divergence matching. Further, a single symmetrical field was created to treat remaining Lumbosacral spine. Matching between a inferior diverging edge of cervicospine field and superior diverging edge of a Lumbosacral field was done using the field alignment option. ′Field alignment′ is specific option in the Eclipse Treatment Planning System, which automatically matches the field edge divergence as per field alignment rule. Multiple segments were applied in both the spine field to manage with hot and cold spots created by varying depth of spinal cord. Plan becomes fully computerized using this field alignment option and multiple segments. Plan evaluation and calculated mean modified Homogeneity Index (1.04 and 0.1 ensured that dose to target volume is homogeneous and critical organ doses were within tolerance. Dose variation at the spinal field junction was verified using ionization chamber array (I′MatriXX for matched, overlapped and gap junction spine fields; the delivered dose distribution confirmed the ideal clinical match, over exposure and under exposure at the junction, respectively. This method is simple to plan, executable in Record and Verify mode and can be adopted for various length of spinal cord with only two isocenter in shorter treatment time.

  19. Cryogenic microwave channelized receiver

    International Nuclear Information System (INIS)

    Rauscher, C.; Pond, J.M.; Tait, G.B.

    1996-01-01

    The channelized receiver being presented demonstrates the use of high temperature superconductor technology in a microwave system setting where superconductor, microwave-monolithic-integrated-circuit, and hybrid-integrated-circuit components are united in one package and cooled to liquid-nitrogen temperatures. The receiver consists of a superconducting X-band four-channel demultiplexer with 100-MHz-wide channels, four commercial monolithically integrated mixers, and four custom-designed hybrid-circuit detectors containing heterostructure ramp diodes. The composite receiver unit has been integrated into the payload of the second-phase NRL high temperature superconductor space experiment (HTSSE-II). Prior to payload assembly, the response characteristics of the receiver were measured as functions of frequency, temperature, and drive levels. The article describes the circuitry, discusses the key issues related to design and implementation, and summarizes the experimental results

  20. Quality of life of lung cancer patients receiving outpatient chemotherapy

    OpenAIRE

    MATSUDA, AYAKO; KOBAYASHI, MIKA; SAKAKIBARA, YUMI; TAMAOKA, MEIYO; FURUIYE, MASASHI; INASE, NAOHIKO; MATSUSHIMA, EISUKE

    2011-01-01

    An increasing number of cancer patients receive outpatient chemotherapy as an alternative to inpatient chemotherapy. The aim of this study was to investigate whether quality of life (QOL) during outpatient chemotherapy was better than QOL prior to hospital discharge, and to explore possible related factors prior to hospital discharge that affected the QOL of lung cancer patients who received outpatient chemotherapy. Lung cancer inpatients who were scheduled for outpatient chemotherapy were as...

  1. Do Managers Manipulate Earnings Prior to Management Buyouts?

    NARCIS (Netherlands)

    Mao, Y.; Renneboog, L.D.R.

    2013-01-01

    Abstract: To address the question as to whether managers manipulate accounting numbers downwards prior to management buyouts (MBOs), we implement an industry-adjusted buyout-specific approach and receive an affirmative answer. In UK buyout companies, negative earnings manipulation (understating the

  2. A single-gradient junction technique to replace multiple-junction shifts for craniospinal irradiation treatment

    International Nuclear Information System (INIS)

    Hadley, Austin; Ding, George X.

    2014-01-01

    Craniospinal irradiation (CSI) requires abutting fields at the cervical spine. Junction shifts are conventionally used to prevent setup error–induced overdosage/underdosage from occurring at the same location. This study compared the dosimetric differences at the cranial-spinal junction between a single-gradient junction technique and conventional multiple-junction shifts and evaluated the effect of setup errors on the dose distributions between both techniques for a treatment course and single fraction. Conventionally, 2 lateral brain fields and a posterior spine field(s) are used for CSI with weekly 1-cm junction shifts. We retrospectively replanned 4 CSI patients using a single-gradient junction between the lateral brain fields and the posterior spine field. The fields were extended to allow a minimum 3-cm field overlap. The dose gradient at the junction was achieved using dose painting and intensity-modulated radiation therapy planning. The effect of positioning setup errors on the dose distributions for both techniques was simulated by applying shifts of ± 3 and 5 mm. The resulting cervical spine doses across the field junction for both techniques were calculated and compared. Dose profiles were obtained for both a single fraction and entire treatment course to include the effects of the conventional weekly junction shifts. Compared with the conventional technique, the gradient-dose technique resulted in higher dose uniformity and conformity to the target volumes, lower organ at risk (OAR) mean and maximum doses, and diminished hot spots from systematic positioning errors over the course of treatment. Single-fraction hot and cold spots were improved for the gradient-dose technique. The single-gradient junction technique provides improved conformity, dose uniformity, diminished hot spots, lower OAR mean and maximum dose, and one plan for the entire treatment course, which reduces the potential human error associated with conventional 4-shifted plans

  3. Retrospective Audit: Does Prior Assessment by Oral and Maxillofacial Surgeons Reduce the Risk of Osteonecrosis of The Jaw in Patients Receiving Bone-Targeted Therapies for Metastatic Cancers to the Skeleton?--Part II.

    Science.gov (United States)

    Turner, Bruce; Ali, Sacha; Pati, Jhumur; Nargund, Vinod; Ali, Enamul; Cheng, Leo; Wells, Paula

    2016-01-01

    Men who receive bone-targeted therapy for metastatic prostate cancer are at increased risk of osteonecrosis of the jaw (ONJ). Development of ONJ has been associated with the administration of bone-targeted therapies in association with other risk factors. ONJ can be distressing for a patient because it can cause pain, risk of jaw fracture, body image disturbance, difficultly eating, and difficulty maintaining good oral hygiene. The aim of this article is to report results of an audit of prior assessment by oral and maxillofacial surgeons (OMFS) before initiation of bone-targeted therapies and whether it may reduce the risk of ONJ in patients receiving bone-targeted therapies for advanced cancers.

  4. Receiver Operating Characteristic Analysis for Classification Based on Various Prior Probabilities of Groups with an Application to Breath Analysis

    Science.gov (United States)

    Cimermanová, K.

    2009-01-01

    In this paper we illustrate the influence of prior probabilities of diseases on diagnostic reasoning. For various prior probabilities of classified groups characterized by volatile organic compounds of breath profile, smokers and non-smokers, we constructed the ROC curve and the Youden index with related asymptotic pointwise confidence intervals.

  5. SU-E-T-372: Dosimetric Comparison of Craniospinal Irradiation Using Different Tomotherapy Techniques

    International Nuclear Information System (INIS)

    Zhang, X; Penagaricano, J; Han, E; Liang, X; Morrill, S; Hardee, M; Gupta, S; Vaneerat, R

    2014-01-01

    Purpose: TomoHDA can treat with fixed jaws, dynamic jaws, and fixed gantry using either 3DCRT or IMRT. This study compares PTV coverage, OAR sparing, and beam-on-time (BOT) among these techniques for craniospinal irradiation (CSI). Methods: This study includes ten CSI patients treated to 23.4 Gy/13 fractions with Hi-Art 3.0 unit (HT-IMRT fixed 5 cm jaw). New plans were regenerated with 5 cm jaw for TomoHDA Hi-Art 5.0 using dynamic jaw (HD-IMRT), TomoDirect-IMRT (TD-IMRT), and Helical Tomotherapy 3DCRT (HT-3DCRT using 5 cm and 2.5 cm jaws with various pitches). Studied parameters include PTV mean dose, D95 (dose covering 95% of PTV), Paddick's conformity index (CI) and homogeneity index (HI – standard deviation of PTV dose/average PTV dose), BOT, and average OAR doses. Results: PTV coverage from these techniques were comparable (p>0.05). The main differences were in OAR sparing; HDIMRT reduced more OAR doses for lenses, bladder and rectum compared to HT-IMRT. For the sparing of visceral organs: liver, lung, heart, and kidneys, the three IMRT techniques gave comparable results. HD-IMRT gave best heart sparing; HT-IMRT best kidney sparing. Liver and lung doses were best reduced by TD-IMRT. All three IMRT techniques gave comparable BOT. OARs sparing was achieved for jaw size of 2.5 cm. HI was also improved but with doubling of BOT. Increasing the pitch number from 0.2 to 0.43 produced no significant improvement in OAR sparing but CI and HI did improve. Conclusion: HT-3DCRT, HT-IMRT, HD-IMRT or TD-IMRT techniques give comparable PTV coverage but the three IMRT plans better spared OARs compared with 3DCRT plans. Dynamic jaw plan is superior to fixed jaw plan to spare more OAR doses at field edge. TD-IMRT cannot reduce BOT for CSI patient but for sparing certain OAR, TD-IMRT may be used to avoid the beam going through the structures of interest

  6. Hyperfractionated craniospinal radiotherapy and adjuvant chemotherapy for children with newly diagnosed medulloblastoma and other primitive neuroectodermal tumors

    International Nuclear Information System (INIS)

    Allen, Jeffrey C.; Donahue, Bernadine; DaRosso, Robert; Nirenberg, Anita

    1996-01-01

    Purpose: This single-institution Phase I/II study conducted from 1989 to 1995 evaluates the feasibility of a multi-modality protocol combining hyperfractionated craniospinal radiotherapy (HFRT) followed by adjuvant chemotherapy in 23 patients with newly diagnosed primitive neuroectodermal tumors (PNET) arising in the central nervous system. Methods and Materials: All 23 patients had a histologically confirmed PNET and were over 3 years of age at diagnosis. The eligibility criteria for PNET patients with cerebellar primaries (medulloblastoma) included either a high T stage (T3b or 4) or high M stage (M1-3). All patients with noncerebellar primaries were eligible regardless of T or M stage. The median age of the 23 patients was 9 years (mean 3-25); 11 were female. The primary tumor arose in the cerebellum in 19. Of these medulloblastoma patients, 15 had high T stages (T3b or T4) with large locally invasive tumors and no evidence of metastases (M0), constituting Group 1. Thirteen (86%) of these patients had gross total resections. Four other medulloblastoma patients had both high T and high M stages, constituting Group 2. Group 3 consisted of four other patients with exocerebellar primaries (two brain, one brain stem, and one cauda equina), three of whom were M3. Hyperfractionated radiotherapy was administered within 4 weeks of surgery. Twice-daily 1-Gy fractions were administered separated by 4-6 h. The total dose to the primary intracranial tumor and other areas of measurable intracranial disease was 72 Gy. The prophylactic craniospinal axis dose was 36 Gy, and boosts of 44-56 Gy were administered to metastatic spinal deposits. Following radiotherapy, monthly courses of multiagent chemotherapy were administered sequentially (cyclophosphamide-vincristine followed by cisplatin-etoposide followed by carboplatin-vincristine) for a total of 9 months. Results: All patients completed radiotherapy as planned. Only three patients lost >10% of their body weight. One patient

  7. Outcomes After Radical Prostatectomy in Men Receiving Prior Pelvic Radiation for Non-Prostate Malignancies

    Science.gov (United States)

    Masterson, Timothy A.; Wedmid, Alexei; Sandhu, Jaspreet S.; Eastham, James A.

    2010-01-01

    Purpose Morbidity associated with salvage radical prostatectomy for locally recurrent prostate cancer after primary radiotherapy is well documented, but little is known about the impact on surgical difficulty and outcomes for radical prostatectomy in men who have had prior pelvic radiotherapy for non-prostate malignancies. We report functional outcomes of 9 patients treated at our institution. Materials and Methods From 1993 to 2007, 9 patients underwent radical prostatectomy following external beam radiotherapy for testicular seminoma (6), anorectal cancer (2), and colon cancer (1). Clinical information was obtained from a prospective prostate cancer database. Results Radical prostatectomy was completed without identifiable injury to adjacent structures in all 9 patients. Four patients had significant pelvic fibrosis, 3 required bilateral neurovascular bundle resection. Neurovascular bundle preservation was performed in the remaining 6 patients, 4 with good preoperative erectile function. However, no patient recovered erectile function postoperatively at a median follow-up time of 75 months (range 12 to 172). Of preoperatively continent men, 57% required ≤1 pad daily and 43% were completely dry, achieving complete urinary control at a median follow-up time of 7.5 months (range 2 to 20). Two patients developed anastomotic stricture, one being associated with concomitant ureteral stricture. Conclusions Radical prostatectomy after pelvic radiotherapy for non-prostate malignancies was not associated with increased intraoperative morbidity. However, rates of anastomotic stricture, erectile dysfunction, and urinary incontinence appear to be higher than those observed after radical prostatectomy in men with no prior radiotherapy and comparable to those seen in the salvage radical prostatectomy setting. PMID:19239447

  8. Sets of priors reflecting prior-data conflict and agreement

    NARCIS (Netherlands)

    Walter, G.M.; Coolen, F.P.A.; Carvalho, J.P.; Lesot, M.-J.; Kaymak, U.; Vieira, S.; Bouchon-Meunier, B.; Yager, R.R.

    2016-01-01

    Bayesian inference enables combination of observations with prior knowledge in the reasoning process. The choice of a particular prior distribution to represent the available prior knowledge is, however, often debatable, especially when prior knowledge is limited or data are scarce, as then

  9. SU-E-T-337: Treatment Planning Study of Craniospinal Irradiation with Spot Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Tasson, A; Beltran, C; Laack, N; Childs, S; Tryggestad, E; Whitaker, T

    2014-01-01

    Purpose: To develop a treatment planning technique that achieves optimal robustness against systematic position and range uncertainties, and interfield position errors for craniospinal irradiation (CSI) using spot scanning proton radiotherapy. Methods: Eighteen CSI patients who had previously been treated using photon radiation were used for this study. Eight patients were less than 10 years old. The prescription dose was 23.4Gy in 1.8Gy fractions. Two different field arrangement types were investigated: 1 posterior field per isocenter and 2 posterior oblique fields per isocenter. For each field type, two delivery configurations were used: 5cm bolus attached to the treatment table and a 4.5cm range shifter located inside the nozzle. The target for each plan was the whole brain and thecal sac. For children under the age of 10, all plan types were repeated with an additional dose of 21Gy prescribed to the vertebral bodies. Treatment fields were matched by stepping down the dose in 10% increments over 9cm. Robustness against 3% and 3mm uncertainties, as well as a 3mm inter-field error was analyzed. Dose coverage of the target and critical structure sparing for each plan type will be considered. Ease of planning and treatment delivery was also considered for each plan type. Results: The mean dose volume histograms show that the bolus plan with posterior beams gave the best overall plan, and all proton plans were comparable to or better than the photon plans. The plan type that was the most robust against the imposed uncertainties was also the bolus plan with posterior beams. This is also the plan configuration that is the easiest to deliver and plan. Conclusion: The bolus plan with posterior beams achieved optimal robustness against systematic position and range uncertainties, as well as inter-field position errors

  10. Receiving more than data - a signal model, theory and implementation of a cognitive IEEE 802.15.4 receiver

    Directory of Open Access Journals (Sweden)

    Tim Esemann

    2016-09-01

    Full Text Available Standard medium access schemes sense the channel immediately prior transmission, but are blind during the transmission. Therefore, standard transceivers have limited cognitive capabilities which are important for operation in heterogeneous radio environments. Specifically, mobile interferers move gradually into the reception range before actually causing collisions. These gradual interferences cannot yet be detected, and upcoming collisions cannot be predicted. We present a theoretical analysis of the received and demodulated signal. This analysis and the derived signal model verifies that the received signal contains more than transmitted data exclusively. Enhanced signal processing extracts signal components of an interference at the receiver and enables advanced interference detection to provide information about approaching mobile interferers. Our theoretical analysis is evaluated by simulations and experiments with an IEEE 802.15.4 transmitter and an extended cognitive receiver.

  11. A Descriptive Analysis of Care Provided by Law Enforcement Prior to EMS Arrival in the United States.

    Science.gov (United States)

    Klassen, Aaron B; Core, S Brent; Lohse, Christine M; Sztajnkrycer, Matthew D

    2018-04-01

    Study Objectives Law enforcement is increasingly viewed as a key component in the out-of-hospital chain of survival, with expanded roles in cardiac arrest, narcotic overdose, and traumatic bleeding. Little is known about the nature of care provided by law enforcement prior to the arrival of Emergency Medical Services (EMS) assets. The purpose of the current study was to perform a descriptive analysis of events reported to a national EMS database. This study was a descriptive analysis of the 2014 National Emergency Medical Services Information System (NEMSIS) public release research data set, containing EMS emergency response data from 41 states. Code E09_02 1200 specifically identifies care provided by law enforcement prior to EMS arrival. A total of 25,835,729 unique events were reported. Of events in which pre-arrival care was documented, 2.0% received prior aid by law enforcement. Patients receiving law enforcement care prior to EMS arrival were more likely to be younger (52.8 [SD=23.3] years versus 58.7 [SD=23.3] years), male (54.8% versus 46.7%), and white (80.3% versus 77.5%). Basic Life Support (BLS) EMS response was twice as likely in patients receiving prior aid by law enforcement. Multiple-casualty incidents were five times more likely with prior aid by law enforcement. Compared with prior aid by other services, law enforcement pre-arrival care was more likely with motor vehicle accidents, firearm assaults, knife assaults, blunt assaults, and drug overdoses, and less likely at falls and childbirths. Cardiac arrest was significantly more common in patients receiving prior aid by law enforcement (16.5% versus 2.6%). Tourniquet application and naloxone administration were more common in the law enforcement prior aid group. Where noted, law enforcement pre-arrival care occurs in 2.0% of EMS patient encounters. The majority of cases involve cardiac arrest, motor vehicle accidents, and assaults. Better understanding of the nature of law enforcement care is

  12. Prior Elicitation, Assessment and Inference with a Dirichlet Prior

    Directory of Open Access Journals (Sweden)

    Michael Evans

    2017-10-01

    Full Text Available Methods are developed for eliciting a Dirichlet prior based upon stating bounds on the individual probabilities that hold with high prior probability. This approach to selecting a prior is applied to a contingency table problem where it is demonstrated how to assess the prior with respect to the bias it induces as well as how to check for prior-data conflict. It is shown that the assessment of a hypothesis via relative belief can easily take into account what it means for the falsity of the hypothesis to correspond to a difference of practical importance and provide evidence in favor of a hypothesis.

  13. Determination of the inferior border of the thecal sac using magnetic resonance imaging: implications on radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Scharf, Carole B.; Paulino, Arnold C.; Goldberg, Kenneth N.

    1998-01-01

    Purpose: To determine whether the traditional teaching of placing the caudal border of the spinal field at the S2-S3 interspace in children receiving craniospinal irradiation (CSI) is appropriate. Methods and Materials: Twenty-three children had magnetic resonance imaging (MRI) of the spine with gadolinium prior to craniospinal irradiation at one institution. Thecal sac termination using MRI was determined by drawing a perpendicular line from the point of convergence of dural margins to the corresponding vertebral body. Results: Location of thecal sac termination varied from mid-S1 to low S3 vertebral body, with the most frequent site at the upper S2 vertebral level. Only 2 of 23 (8.7%) children had thecal sac terminations below the S2-S3 interspace. For the nine patients with neuraxis disease, none had thecal sac terminations below the S2-S3 interspace. In seven of the nine patients who had neuraxis seeding at initial presentation, MRI of the spine after CSI was performed and showed that thecal sac termination was lower after radiation therapy in two children, higher in one, and the same in four. Conclusions: In 2 of 23 children (8.7%), placement of the inferior border at the bottom of the S2 vertebral body would have missed the entire thecal sac. Treatment to the entire neuraxis with adequate coverage of distal spinal theca can be achieved by using MRI. Individualized spinal fields using the MRI may help minimize radiation scatter to the gonads while adequately covering the target volume

  14. Intrathecal trastuzumab in the management of HER2+ breast leptomeningeal disease: a single institution experience.

    Science.gov (United States)

    Figura, Nicholas B; Long, Wendy; Yu, Michael; Robinson, Timothy J; Mokhtari, Sepideh; Etame, Arnold B; Tran, Nam D; Diaz, Roberto; Soliman, Hatem; Han, Heather S; Sahebjam, Solmaz; Forsyth, Peter A; Ahmed, Kamran A

    2018-06-01

    Leptomeningeal disease is a rare and devastating presentation of advanced stage metastatic breast cancer with historically poor overall survival. We assessed the safety and feasibility of intrathecal (IT) trastuzumab in HER2+ leptomeningeal disease. A total of 13 patients were treated at our institution with IT trastuzumab beginning November 2012 and followed until November 2017. Outcomes including craniospinal progression as well as overall survival (OS) following initiation of IT trastuzumab were assessed from review of the clinical chart and radiologic examinations. The median age of patients was 48 (range 29-75). Median time from breast cancer diagnosis to development of brain metastases was 87.7 months with a median of 4.6 months from brain metastases diagnosis to the development of leptomeningeal disease. Previous whole brain radiotherapy was received by the majority of patients (92%) and prior surgery for brain metastases was performed in 23%. Median duration of IT trastuzumab treatment was 6.4 months. Median time from IT trastuzumab start to craniospinal progression was 5.7 months with 6- and 12-month Kaplan-Meier rates of 41 and 21%, respectively. Sustained responses > 6 months were achieved in 4 patients. Median survival from the start of IT trastuzumab was 10.6 months with 6- and 12-month OS rates of 68 and 47%, respectively. IT trastuzumab was well tolerated with one patient developing ventriculitis, which resolved with IV antibiotics. IT trastuzumab was well tolerated with prolongation of OS over historical controls. IT trastuzumab should be considered for management of HER2+ leptomeningeal disease patients.

  15. 29 CFR 779.248 - Purchase or receive “goods for resale.”

    Science.gov (United States)

    2010-07-01

    ... section 3(s)(1) of the prior Act if they are purchased or received with the intention of being resold... purchased or received by the enterprise with the intention of reselling them in the same form or after... 29 Labor 3 2010-07-01 2010-07-01 false Purchase or receive âgoods for resale.â 779.248 Section 779...

  16. Evaluation of localization errors for craniospinal axis irradiation delivery using volume modulated arc therapy and proposal of a technique to minimize such errors

    International Nuclear Information System (INIS)

    Myers, Pamela; Stathakis, Sotirios; Mavroidis, Panayiotis; Esquivel, Carlos; Papanikolaou, Niko

    2013-01-01

    Purpose: To dosimetrically evaluate the effects of improper patient positioning in the junction area of a VMAT cranio-spinal axis irradiation technique consisting of one superior and one inferior arc and propose a solution to minimize these patient setup errors. Methods: Five (n = 5) cranio-spinal axis irradiation patients were planned with 2 arcs: one superior and one inferior. In order to mimic patient setup errors, the plans were recalculated with the inferior isocenter shifted by: 1, 2, 5, and 10 mm superiorly, and 1, 2, 5, and 10 mm inferiorly. The plans were then compared with the corresponding original, non-shifted arc plans on the grounds of target metrics such as conformity number and homogeneity index, as well as several normal tissue dose descriptors. “Gradient-optimized” plans were then created for each patient in an effort to reduce dose discrepancies due to setup errors. Results: Percent differences were calculated in order to compare each of the eight shifted plans with the original non-shifted arc plan, which corresponds to the ideal patient setup. The conformity number was on average lower by 0.9%, 2.7%, 5.8%, and 9.1% for the 1, 2, 5, and 10 mm inferiorly-shifted plans and 0.4%, 0.8%, 2.8%, and 6.0% for the respective superiorly-shifted plans. The homogeneity indices were, averaged among the five patients and they indicated less homogeneous dose distributions by 0.03%, 0.3%, 1.0%, and 2.8% for the inferior shifts and 0.2%, 1.2%, 6.3%, and 15.3% for the superior shifts. Overall, the mean doses to the organs at risk deviate by less than 2% for the 1, 2, and 5 mm shifted plans. The 10 mm shifted plans, however, showed average percent differences, over all studied organs, from the original plan of up to 5.6%. Using “gradient-optimized” plans, the average dose differences were reduced by 0.2%, 0.5%, 1.2%, and 2.1% for 1, 2, 5, and 10 mm shifts, respectively compared to the originally optimized plans, and the maximum dose differences were

  17. Preparing learners with partly incorrect intuitive prior knowledge for learning

    Directory of Open Access Journals (Sweden)

    Andrea eOhst

    2014-07-01

    Full Text Available Learners sometimes have incoherent and fragmented intuitive prior knowledge that is (partly ‘incompatible’ with the to-be-learned contents. Such knowledge in pieces can cause conceptual disorientation and cognitive overload while learning. We hypothesized that a pre-training intervention providing a generalized schema as a structuring framework for such knowledge in pieces would support (reorganizing-processes of prior knowledge and thus reduce unnecessary cognitive load during subsequent learning. Fifty-six student teachers participated in the experiment. A framework group underwent a pre-training intervention providing a generalized, categorical schema for categorizing primary learning strategies and related but different strategies as a cognitive framework for (re-organizing their prior knowledge. Our control group received comparable factual information but no framework. Afterwards, all participants learned about primary learning strategies. The framework group claimed to possess higher levels of interest and self-efficacy, achieved higher learning outcomes, and learned more efficiently. Hence, providing a categorical framework can help overcome the barrier of incorrect prior knowledge in pieces.

  18. Preparing learners with partly incorrect intuitive prior knowledge for learning

    Science.gov (United States)

    Ohst, Andrea; Fondu, Béatrice M. E.; Glogger, Inga; Nückles, Matthias; Renkl, Alexander

    2014-01-01

    Learners sometimes have incoherent and fragmented intuitive prior knowledge that is (partly) “incompatible” with the to-be-learned contents. Such knowledge in pieces can cause conceptual disorientation and cognitive overload while learning. We hypothesized that a pre-training intervention providing a generalized schema as a structuring framework for such knowledge in pieces would support (re)organizing-processes of prior knowledge and thus reduce unnecessary cognitive load during subsequent learning. Fifty-six student teachers participated in the experiment. A framework group underwent a pre-training intervention providing a generalized, categorical schema for categorizing primary learning strategies and related but different strategies as a cognitive framework for (re-)organizing their prior knowledge. Our control group received comparable factual information but no framework. Afterwards, all participants learned about primary learning strategies. The framework group claimed to possess higher levels of interest and self-efficacy, achieved higher learning outcomes, and learned more efficiently. Hence, providing a categorical framework can help overcome the barrier of incorrect prior knowledge in pieces. PMID:25071638

  19. Efficacy and toxicity of rectal cancer reirradiation using IMRT for patients who have received prior pelvic radiation therapy

    Directory of Open Access Journals (Sweden)

    Fady F. Youssef, MS

    2016-04-01

    Conclusions: Rectal cancer reirradiation using IMRT is well-tolerated in the setting of prior pelvic radiation therapy. Given significant risk of local progression, further dose escalation may be warranted for patients with life expectancy exceeding 1 year.

  20. Paediatric medulloblastoma: patterns of care and radiotherapy quality assurance in Australia

    International Nuclear Information System (INIS)

    Ahern, V.; Koh, E-S.; Gebski, V.; Sathiyaseelan, Y.

    2007-01-01

    Full text: The purpose of this study was to document how children in Australia with medulloblastoma are being treated and to evaluate the quality of radiotherapy (RT) delivered. The Radiotherapy Database of the Australian and New Zealand Children's Haematology and Oncology Group was used to identify 46 children with medulloblastoma younger than the age of 15 years treated with radical intent by craniospinal irradiation between 1997 and 1999 inclusively. Twenty-six patients had completely resected disease without evidence of disease spread. Of these, 16 patients received a craniospinal RT dose of <25 Gy in addition to chemotherapy. RT treatment immobilization methods varied, as did planning methods. RT dose to critical structures was recorded on treatment plans for only 15% of patients. The average systematic error in shield placement at the posterior orbit was 5.2 mm, and two-thirds of patients were 'overshielded' at this site. Adequate coverage of the distal end of the thecal sac was achieved in fewer than 50% of on-treatment verification films for 21 of 45 patients. With a reduction in RT dose to the craniospinal axis for paediatric medulloblastoma, greater attention is needed for patient immobilization, documentation of RT dose to critical structures and the placement and reproducibility of shielding

  1. The Effect of Prior Caffeine Consumption on Neuropsychological Test Performance: A Placebo-Controlled Study.

    Science.gov (United States)

    Walters, Elizabeth R; Lesk, Valerie E

    2016-01-01

    The aim of this study was to investigate whether the prior consumption of 200 mg of pure caffeine affected neuropsychological test scores in a group of elderly participants aged over 60 years. Using a double-blind placebo versus caffeine design, participants were randomly assigned to receive 200 mg of caffeine or placebo. A neuropsychological assessment testing the domains of general cognitive function, processing speed, semantic memory, episodic memory, executive function, working memory and short-term memory was carried out. Significant interaction effects between age, caffeine and scores of executive function and processing speed were found; participants who had received caffeine showed a decline in performance with increasing age. This effect was not seen for participants who received placebo. The results highlight the need to consider and control prior caffeine consumption when scoring neuropsychological assessments in the elderly, which is important for accuracy of diagnosis and corresponding normative data. © 2016 S. Karger AG, Basel.

  2. Long-term effects of treatment on endocrine function in children with brain tumors

    International Nuclear Information System (INIS)

    Duffner, P.K.; Cohen, M.E.; Anderson, S.W.; Voorhess, M.L.; MacGillivray, M.H.; Panahon, A.; Brecher, M.L.

    1983-01-01

    Fourteen children with brain tumors received endocrine evaluations at least one year following completion of cranial irradiation. Treatment consisted of operation (13 patients), craniospinal irradiation (6), whole brain irradiation (5), posterior fossa irradiation (3), and chemotherapy (10). Endocrine evaluation included bone age roentgenography and measurement of growth hormone (using sequential arginine and insulin stimulation), thyroxine, thyroid-stimulating hormone, plasma cortisol, testosterone, prolactin, and urinary follicle-stimulating hormone and luteinizing hormone. Ten of 12 children (83%) had abnormal responses to both tests of growth hormone stimulation. All growth hormone-deficient patients treated prior to puberty and tested at least 2 years following completion of cranial irradiation had decelerated linear growth. Results of thyroid function tests were abnormal in 4 patients: 2 patients had evidence of primary hypothyroidism, and 2 showed secondary or tertiary hypothyroidism. Two patients had inadequate cortisol responses to insulin hypoglycemia. Urinary follicle-stimulating hormone and luteinizing hormone, serum prolactin, and serum testosterone levels were appropriate for age in all patients

  3. Employment Interventions for Individuals with ASD: The Relative Efficacy of Supported Employment With or Without Prior Project SEARCH Training.

    Science.gov (United States)

    Schall, Carol M; Wehman, Paul; Brooke, Valerie; Graham, Carolyn; McDonough, Jennifer; Brooke, Alissa; Ham, Whitney; Rounds, Rachael; Lau, Stephanie; Allen, Jaclyn

    2015-12-01

    This paper presents findings from a retrospective observational records review study that compares the outcomes associated with implementation of supported employment (SE) with and without prior Project SEARCH with ASD Supports (PS-ASD) on wages earned, time spent in intervention, and job retention. Results suggest that SE resulted in competitive employment for 45 adults with ASD. Twenty-five individuals received prior intervention through PS-ASD while the other 20 individuals received SE only. Individuals in this sample who received PS-ASD required fewer hours of intervention. Additionally, individuals in the PS-ASD group achieved a mean higher wage and had higher retention rates than their peers who received SE only. Further research with a larger sample is needed to confirm these findings.

  4. Impact of prior therapies on everolimus activity: an exploratory analysis of RADIANT-4.

    Science.gov (United States)

    Buzzoni, Roberto; Carnaghi, Carlo; Strosberg, Jonathan; Fazio, Nicola; Singh, Simron; Herbst, Fabian; Ridolfi, Antonia; Pavel, Marianne E; Wolin, Edward M; Valle, Juan W; Oh, Do-Youn; Yao, James C; Pommier, Rodney

    2017-01-01

    Recently, everolimus was shown to improve median progression-free survival (PFS) by 7.1 months in patients with advanced, progressive, well-differentiated, nonfunctional neuroendocrine tumors (NET) of lung or gastrointestinal (GI) tract compared with placebo (HR, 0.48; 95% CI, 0.35-0.67; P <0.00001) in the Phase III, RADIANT-4 study. This post hoc analysis evaluates the impact of prior therapies (somatostatin analogs [SSA], chemotherapy, and radiotherapy) on everolimus activity. ClinicalTrials.gov identifier: NCT01524783. Patients were randomized (2:1) to everolimus 10 mg/day or placebo, both with best supportive care. Subgroups of patients who received prior SSA, chemotherapy, or radiotherapy (including peptide receptor radionuclide therapy) were analyzed and reported. A total of 302 patients were enrolled, of whom, 163 (54%) had any prior SSA use (mostly for tumor control), 77 (25%) received chemotherapy, and 63 (21%) were previously exposed to radiotherapy. Patients who received everolimus had longer median PFS compared with placebo, regardless of previous SSA (with SSA: 11.1 vs 4.5 months [HR, 0.56 {95% CI, 0.37-0.85}]; without SSA: 9.5 vs 3.7 months [0.57 {0.36-0.89}]), chemotherapy (with chemotherapy: 9.2 vs 2.1 months [0.35 {0.19-0.64}]; without chemotherapy: 11.2 vs 5.4 months [0.60 {0.42-0.86}]), or radiotherapy (with radiotherapy: 9.2 vs 3.0 months [0.47 {0.24-0.94}]; without radiotherapy: 11 vs 5.1 months [0.59 {0.42-0.83}]) exposure. The most frequent drug-related adverse events included stomatitis (59%-65%), fatigue (27%-35%), and diarrhea (24%-34%) among the subgroups. These results suggest that everolimus improves PFS in patients with advanced, progressive lung or GI NET, regardless of prior therapies. Safety findings were consistent with the known safety profile of everolimus in NET.

  5. Radiation doses to normal tissues during craniospinal irradiation ...

    African Journals Online (AJOL)

    Mohamed Farouk Mostafa

    2011-10-15

    Oct 15, 2011 ... not in the center of the brain as this shows lower doses to eyes and lenses. ª 2011 Alexandria .... dose plan function was used to check the dose coverage of the .... maximum dose received by the right and left lens were listed.

  6. Guanfacine extended release for children and adolescents with attention-deficit/hyperactivity disorder: efficacy following prior methylphenidate treatment

    Directory of Open Access Journals (Sweden)

    Huss M

    2016-05-01

    Full Text Available Michael Huss,1 Vanja Sikirica,2 Amaia Hervas,3,4 Jeffrey H Newcorn,5 Valerie Harpin,6 Brigitte Robertson71Child and Adolescent Psychiatry, Johannes Gutenberg University Mainz, Mainz, Germany; 2Global Health Economics, Outcomes Research and Epidemiology, Shire, Wayne, PA, USA; 3Child and Adolescent Mental Health Unit, University Hospital Mútua de Terressa, Barcelona, Spain; 4Developmental Disorders Unit (UETD, Hospital San Juan de Dios, Barcelona, Spain; 5Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; 6Ryegate Children’s Centre, Sheffield Children’s NHS Foundation Trust, Sheffield, UK; 7Global Clinical Development, Shire, Wayne, PA, USAAbstract: Guanfacine extended release (GXR and atomoxetine (ATX are nonstimulant treatments for attention-deficit/hyperactivity disorder (ADHD. As nonstimulant treatments are often used after stimulants in ADHD, GXR was assessed relative to prior stimulant treatment in a randomized controlled trial (RCT, in which ATX was included as a reference arm, and in the open-label phase of a randomized-withdrawal study (RWS. Participants were 6–17 years old with ADHD Rating Scale version IV (ADHD-RS-IV scores ≥32 and Clinical Global Impressions – Severity scores ≥4. RCT participants received dose-optimized GXR (1–7 mg/day, ATX (10–100 mg/day, or placebo for 10–13 weeks. RWS participants received dose-optimized GXR (1–7 mg/day for 13 weeks. Participants’ last stimulant medication prior to enrolment, and reasons for stopping this medication, were collected at baseline. Change from baseline ADHD-RS-IV score and the proportion of responders were assessed by prior stimulant exposure. Of 163 RCT and 296 RWS participants who had previously received stimulant treatment, 142 and 224, respectively, had received methylphenidate (MPH; due to the low number of participants and the heterogeneity of non-MPH treatments, we only report data for prior MPH treatment. The most

  7. External Prior Guided Internal Prior Learning for Real-World Noisy Image Denoising

    Science.gov (United States)

    Xu, Jun; Zhang, Lei; Zhang, David

    2018-06-01

    Most of existing image denoising methods learn image priors from either external data or the noisy image itself to remove noise. However, priors learned from external data may not be adaptive to the image to be denoised, while priors learned from the given noisy image may not be accurate due to the interference of corrupted noise. Meanwhile, the noise in real-world noisy images is very complex, which is hard to be described by simple distributions such as Gaussian distribution, making real noisy image denoising a very challenging problem. We propose to exploit the information in both external data and the given noisy image, and develop an external prior guided internal prior learning method for real noisy image denoising. We first learn external priors from an independent set of clean natural images. With the aid of learned external priors, we then learn internal priors from the given noisy image to refine the prior model. The external and internal priors are formulated as a set of orthogonal dictionaries to efficiently reconstruct the desired image. Extensive experiments are performed on several real noisy image datasets. The proposed method demonstrates highly competitive denoising performance, outperforming state-of-the-art denoising methods including those designed for real noisy images.

  8. Effects of prior aversive experience upon retrograde amnesia induced by hypothermia.

    Science.gov (United States)

    Jensen, R A; Riccio, D C; Gehres, L

    1975-08-01

    Two experiments examined the extent to which retrograde amnesia (RA) is attenuated by prior learning experiences. In Experiment 1, rats initially received either passive avoidance training in a step-through apparatus, exposure to the apparatus, or noncontingent footshock. When training on a second but different passive avoidance task was followed by hypothermia treatment, RA was obtained only in the latter two groups. In Experiment 2, one-way active avoidance training, yoked noncontingent shocks, or apparatus exposure constituted the initial experience. Subsequent step-down passive avoidance training and amnestic treatment resulted in memory loss for the prior apparatus exposure group, but not for either of the preshocked conditions. These experiments demonstrate that certain types of prior aversive experience can substantially modify the magnitude of RA, and, in conjunction with other familiarization studies, emphasize a paradox for interpretations of RA based solely upon CNS disruption. The possibility that hypothermia treatment serves as an important contextual or encoding cue necessary for memory retrieval was considered. It was suggested that prior experience may block RA by enabling rats to differentiate training and treatment conditions.

  9. Refractory status epilepticus in children with and without prior epilepsy or status epilepticus.

    Science.gov (United States)

    Sánchez Fernández, Iván; Jackson, Michele C; Abend, Nicholas S; Arya, Ravindra; Brenton, James N; Carpenter, Jessica L; Chapman, Kevin E; Gaillard, William D; Gaínza-Lein, Marina; Glauser, Tracy A; Goldstein, Joshua L; Goodkin, Howard P; Helseth, Ashley; Kapur, Kush; McDonough, Tiffani L; Mikati, Mohamad A; Peariso, Katrina; Riviello, James; Tasker, Robert C; Topjian, Alexis A; Wainwright, Mark S; Wilfong, Angus; Williams, Korwyn; Loddenkemper, Tobias

    2017-01-24

    To compare refractory convulsive status epilepticus (rSE) management and outcome in children with and without a prior diagnosis of epilepsy and with and without a history of status epilepticus (SE). This was a prospective observational descriptive study performed from June 2011 to May 2016 on pediatric patients (1 month-21 years of age) with rSE. We enrolled 189 participants (53% male) with a median (25th-75th percentile) age of 4.2 (1.3-9.6) years. Eighty-nine (47%) patients had a prior diagnosis of epilepsy. Thirty-four (18%) patients had a history of SE. The time to the first benzodiazepine was similar in participants with and without a diagnosis of epilepsy (15 [5-60] vs 16.5 [5-42.75] minutes, p = 0.858). Patients with a diagnosis of epilepsy received their first non-benzodiazepine (BZD) antiepileptic drug (AED) later (93 [46-190] vs 50.5 [28-116] minutes, p = 0.002) and were less likely to receive at least one continuous infusion (35/89 [39.3%] vs 57/100 [57%], p = 0.03). Compared to patients with no history of SE, patients with a history of SE received their first BZD earlier (8 [3.5-22.3] vs 20 [5-60] minutes, p = 0.0073), although they had a similar time to first non-BZD AED (76.5 [45.3-124] vs 65 [32.5-156] minutes, p = 0.749). Differences were mostly driven by the patients with an out-of-hospital rSE onset. Our study establishes that children with rSE do not receive more timely treatment if they have a prior diagnosis of epilepsy; however, a history of SE is associated with more timely administration of abortive medication. © 2016 American Academy of Neurology.

  10. Cryptococcal infections in two patients receiving ibrutinib therapy for chronic lymphocytic leukemia.

    Science.gov (United States)

    Stankowicz, Matthew; Banaszynski, Megan; Crawford, Russell

    2018-01-01

    Cryptococcal infections are responsible for significant morbidity and mortality in immunocompromised patients. Reports of these infections in patients on small molecular kinase inhibitors have not been widely reported in clinical trials. We describe one case of cryptococcal meningoencephalitis and one case of cryptococcal pneumonia in two patients who were receiving ibrutinib for chronic lymphocytic leukemia. Despite different sites of cryptococcal infection, both patients had similar presentations of acute illness. Patient 1 was worked up for health care-associated pneumonia, as well as acute sinusitis prior to the diagnosis of cryptococcal meningoencephalitis. He also had a more complex past medical history than patient 2. Patient 2 developed atrial fibrillation from ibrutinib prior to admission for presumed health care-associated pneumonia. Cryptococcal antigen testing was done sooner in this patient due to patient receiving high-dose steroids for the treatment of underlying hemolytic anemia. We conclude that patients who develop acute illness while receiving ibrutinib should be considered for cryptococcal antigen testing.

  11. Lessons learned: the effect of prior technology use on Web-based interventions.

    Science.gov (United States)

    Carey, Joanne C; Wade, Shari L; Wolfe, Christopher R

    2008-04-01

    This study examined the role of regular prior technology use in treatment response to an online family problem-solving (OFPS) intervention and an Internet resource intervention (IRI) for pediatric traumatic brain injury (TBI). Participants were 150 individuals in 40 families of children with TBI randomly assigned to OFPS intervention or an IRI. All families received free computers and Internet access to TBI resources. OFPS families received Web-based sessions and therapist-guided synchronous videoconferences focusing on problem solving, communication skills, and behavior management. All participants completed measures of depression, anxiety, and computer usage. OFPS participants rated treatment satisfaction, therapeutic alliance, and Web site and technology comfort. With the OFPS intervention, depression and anxiety improved significantly more among technology using parents (n = 14) than nontechnology users (n = 6). Technology users reported increasing comfort with technology over time, and this change was predictive of depression at followup. Satisfaction and ease-of-use ratings did not differ by technology usage. Lack of regular prior home computer usage and nonadherence were predictive of anxiety at followup. The IRI was not globally effective. However, controlling for prior depression, age, and technology at work, there was a significant effect of technology at home for depression. Families with technology experience at home (n = 11) reported significantly greater improvements in depression than families without prior technology experience at home (n = 8). Although Web-based OFPS was effective in improving caregiver functioning, individuals with limited computer experience may benefit less from an online intervention due to increased nonadherence.

  12. Radiation doses to normal tissues during craniospinal irradiation ...

    African Journals Online (AJOL)

    Objective: This dosimetric study is aiming to report the results of the analysis of doses received by target volumes and organs outside the target volumes during the treatment of medulloblastoma patients. And also by comparing the doses reaching the eyes and the lens with the use of different shielding methods.

  13. Craniospinal versus whole brain irradiation in Medulloblastoma patients, with introduction of utilizing a simple immobilization device

    Directory of Open Access Journals (Sweden)

    Haddad P

    2001-05-01

    Full Text Available Craniospinal irradiation plus posterior fossa boost (CS1 is the standard modality of post-operative treatment of patient with medulloblastoma, but considering the technical difficulties and limited facilities, often whole- brain irradiation plus posterior fossa boost (WBI had been used in our institution until 1991. Tust a retrospective study was undertaken to compare the patients treated by By WBI and CSI for recurrences and disease-free survival (DFS. Files of all medullobalstoma patients treated post-operatively in our department in the 10 – year period of 1986-1996 were reviewed. To obtain the best possible follow- up, a formal inquiry letter was mailed to all patients’ addresses.Total of 72 patients had been treated, with a mean age of 14.7 years and male-to-female ratio of 1.5:1 Thirty –seven patients had been treated by WBI and 35 by CS. A simple wooden device designed and made in our department was used for CSI patients’ set-up and immobilization. Mean radiation dose to posterior fossa was 4, 765 cGy in WBT and 5, 071 cGY in CSI (180-200 cGy fractions. Sixty-two patients (85% came back for follow-up, with 24 recurrences. Only 24% of CSI patients had recurrences, versus 51% in WBI Nearly all Wbi recurrences versus half of the CSI recurrences were spinal. DFS was 39 months in CSI and 26 months in WBI (P<0.001 . in multi-factorial analysis, only the extent of radiation (CSI versus WBI, P<0.001 was statistically significant. Mean age in our patients was higher than what is commonly reported in literature. The immobilization device introduce was a simple and useful accessory to CSI. Considering DFS, CSI in our department was acceptabley comparable to literature results and significantly superior to WBI. With regard to relatively high spinal recurrence rate even in CSI, the importance of suitable spinal cytological and imaging evaluation is again emphasized.

  14. Web-Based Alcohol Intervention in First-Year College Students: Efficacy of Full-Program Administration Prior to Second Semester.

    Science.gov (United States)

    Gilbertson, Rebecca J; Norton, Tina R; Beery, Susan H; Lee, Kassandra R

    2018-05-12

    Commercially available, web-based interventions for the prevention of alcohol use are being adopted for universal use with first-year college students, yet few have received empirical evaluation. This randomized controlled trial investigated the effectiveness of a novel, commercially available, personalized web-based alcohol intervention, Alcohol-Wise (version 4.0, 3 rd Millennium Classrooms), on multiple measures of alcohol consumption, alcohol consequences, alcohol expectancies, academic achievement, and adaptation to college in first-year students. Participants received Alcohol-Wise either prior to first semester or were waitlisted and received the intervention second semester. As longitudinal effectiveness was of interest, follow-up surveys were conducted 10 weeks (n = 76) and 24 weeks (n = 64) following the web-based alcohol intervention. Completion of Alcohol-Wise had effects on academic achievement. Specifically, at the 24 week follow-up, academic achievement was higher in participants who received the intervention first semester of their freshman year as compared to the waitlist control. The incremental rise in heavy episodic drinking during the first semester of college was also reduced in waitlisted participants by Alcohol-Wise administration prior to second semester. Conclusion/Importance: Implications for the timing of web-based alcohol interventions to include administration prior to both first and second semesters of the freshman year are discussed.

  15. Murine immune responses to oral BCG immunization in the presence or absence of prior BCG sensitization.

    Science.gov (United States)

    Cross, Martin L; Lambeth, Matthew R; Aldwell, Frank E

    2010-02-01

    Oral delivery of live Mycobacterium bovis BCG in a lipid matrix invokes cell-mediated immune (CMI) responses in mice and consequent protection against pulmonary challenge with virulent mycobacteria. To investigate the influence of prior BCG sensitization on oral vaccine efficacy, we assessed CMI responses and BCG colonization of the alimentary tract lymphatics 5 months after oral vaccination, in both previously naive mice and in mice that had been sensitized to BCG by injection 6 months previously. CMI responses did not differ significantly between mice that received subcutaneous BCG followed by oral BCG and those that received either injected or oral BCG alone. In vivo BCG colonization was predominant in the mesenteric lymph nodes after oral vaccination; this colonizing ability was not influenced by prior BCG sensitization. From this murine model study, we conclude that although prior parenteral-route BCG sensitization does not detrimentally affect BCG colonization after oral vaccination, there is no significant immune-boosting effect of the oral vaccine either.

  16. Reasons for receiving or not receiving HPV vaccination in primary schoolgirls in Tanzania: a case control study.

    Science.gov (United States)

    Watson-Jones, Deborah; Tomlin, Keith; Remes, Pieter; Baisley, Kathy; Ponsiano, Riziki; Soteli, Selephina; de Sanjosé, Silvia; Changalucha, John; Kapiga, Saidi; Hayes, Richard J

    2012-01-01

    There are few data on factors influencing human papillomavirus (HPV) vaccination uptake in sub-Saharan Africa. We examined the characteristics of receivers and non-receivers of HPV vaccination in Tanzania and identified reasons for not receiving the vaccine. We conducted a case control study of HPV vaccine receivers and non-receivers within a phase IV cluster-randomised trial of HPV vaccination in 134 primary schools in Tanzania. Girls who failed to receive vaccine (pupil cases) and their parents/guardians (adult cases) and girls who received dose 1 (pupil controls) of the quadrivalent vaccine (Gardasil™) and their parents/guardians (adult controls) were enrolled from 39 schools in a 1∶1 ratio and interviewed about cervical cancer, HPV vaccine knowledge and reasons why they might have received or not received the vaccine. Conditional logistic regression was used to determine factors independently associated with not receiving HPV vaccine. We interviewed 159 pupil/adult cases and 245 pupil/adult controls. Adult-factors independently associated with a daughter being a case were older age, owning fewer household items, not attending a school meeting about HPV vaccine, and not knowing anyone with cancer. Pupil-factors for being a case included having a non-positive opinion about the school de-worming programme, poor knowledge about the location of the cervix, and not knowing that a vaccine could prevent cervical cancer. Reasons for actively refusing vaccination included concerns about side effects and infertility. Most adult and pupil cases reported that they would accept the HPV vaccine if it were offered again (97% and 93% respectively). Sensitisation messages, especially targeted at older and poorer parents, knowledge retention and parent meetings are critical for vaccine acceptance in Tanzania. Vaccine side effects and fertility concerns should be addressed prior to a national vaccination program. Parents and pupils who initially decline vaccination should be

  17. Poster - Thur Eve - 57: Craniospinal irradiation with jagged-junction IMRT approach without beam edge matching for field junctions.

    Science.gov (United States)

    Cao, F; Ramaseshan, R; Corns, R; Harrop, S; Nuraney, N; Steiner, P; Aldridge, S; Liu, M; Carolan, H; Agranovich, A; Karva, A

    2012-07-01

    Craniospinal irradiation were traditionally treated the central nervous system using two or three adjacent field sets. A intensity-modulated radiotherapy (IMRT) plan (Jagged-Junction IMRT) which overcomes problems associated with field junctions and beam edge matching, improves planning and treatment setup efficiencies with homogenous target dose distribution was developed. Jagged-Junction IMRT was retrospectively planned on three patients with prescription of 36 Gy in 20 fractions and compared to conventional treatment plans. Planning target volume (PTV) included the whole brain and spinal canal to the S3 vertebral level. The plan employed three field sets, each with a unique isocentre. One field set with seven fields treated the cranium. Two field sets treated the spine, each set using three fields. Fields from adjacent sets were overlapped and the optimization process smoothly integrated the dose inside the overlapped junction. For the Jagged-Junction IMRT plans vs conventional technique, average homogeneity index equaled 0.08±0.01 vs 0.12±0.02, and conformity number equaled 0.79±0.01 vs 0.47±0.12. The 95% isodose surface covered (99.5±0.3)% of the PTV vs (98.1±2.0)%. Both Jagged-Junction IMRT plans and the conventional plans had good sparing of the organs at risk. Jagged-Junction IMRT planning provided good dose homogeneity and conformity to the target while maintaining a low dose to the organs at risk. Jagged-Junction IMRT optimization smoothly distributed dose in the junction between field sets. Since there was no beam matching, this treatment technique is less likely to produce hot or cold spots at the junction in contrast to conventional techniques. © 2012 American Association of Physicists in Medicine.

  18. Comparison of therapeutic dosimetric data from passively scattered proton and photon craniospinal irradiations for medulloblastoma

    Directory of Open Access Journals (Sweden)

    Howell Rebecca M

    2012-07-01

    Full Text Available Abstract Background For many decades, the standard of care radiotherapy regimen for medulloblastoma has been photon (megavoltage x-rays craniospinal irradiation (CSI. The late effects associated with CSI are well-documented in the literature and are in-part attributed to unwanted dose to healthy tissue. Recently, there is growing interest in using proton therapy for CSI in pediatric and adolescent patients to reduce this undesirable dose. Previous comparisons of dose to target and non-target organs from conventional photon CSI and passively scattered proton CSI have been limited to small populations (n ≤ 3 and have not considered the use of age-dependent target volumes in proton CSI. Methods Standard of care treatment plans were developed for both photon and proton CSI for 18 patients. This cohort included both male and female medulloblastoma patients whose ages, heights, and weights spanned a clinically relevant and representative spectrum (age 2–16, BMI 16.4–37.9 kg/m2. Differences in plans were evaluated using Wilcoxon signed rank tests for various dosimetric parameters for the target volumes and normal tissue. Results Proton CSI improved normal tissue sparing while also providing more homogeneous target coverage than photon CSI for patients across a wide age and BMI spectrum. Of the 24 parameters (V5, V10, V15, and V20 in the esophagus, heart, liver, thyroid, kidneys, and lungs Wilcoxon signed rank test results indicated 20 were significantly higher for photon CSI compared to proton CSI (p ≤ 0.05 . Specifically, V15 and V20 in all six organs and V5, V10 in the esophagus, heart, liver, and thyroid were significantly higher with photon CSI. Conclusions Our patient cohort is the largest, to date, in which CSI with proton and photon therapies have been compared. This work adds to the body of literature that proton CSI reduces dose to normal tissue compared to photon CSI for pediatric patients who are at substantial risk for

  19. Comparison of therapeutic dosimetric data from passively scattered proton and photon craniospinal irradiations for medulloblastoma

    International Nuclear Information System (INIS)

    Howell, Rebecca M; Giebeler, Annelise; Koontz-Raisig, Wendi; Mahajan, Anita; Etzel, Carol J; D’Amelio, Anthony M Jr; Homann, Kenneth L

    2012-01-01

    For many decades, the standard of care radiotherapy regimen for medulloblastoma has been photon (megavoltage x-rays) craniospinal irradiation (CSI). The late effects associated with CSI are well-documented in the literature and are in-part attributed to unwanted dose to healthy tissue. Recently, there is growing interest in using proton therapy for CSI in pediatric and adolescent patients to reduce this undesirable dose. Previous comparisons of dose to target and non-target organs from conventional photon CSI and passively scattered proton CSI have been limited to small populations (n ≤ 3) and have not considered the use of age-dependent target volumes in proton CSI. Standard of care treatment plans were developed for both photon and proton CSI for 18 patients. This cohort included both male and female medulloblastoma patients whose ages, heights, and weights spanned a clinically relevant and representative spectrum (age 2–16, BMI 16.4–37.9 kg/m2). Differences in plans were evaluated using Wilcoxon signed rank tests for various dosimetric parameters for the target volumes and normal tissue. Proton CSI improved normal tissue sparing while also providing more homogeneous target coverage than photon CSI for patients across a wide age and BMI spectrum. Of the 24 parameters (V 5 , V 10 , V 15 , and V 20 in the esophagus, heart, liver, thyroid, kidneys, and lungs) Wilcoxon signed rank test results indicated 20 were significantly higher for photon CSI compared to proton CSI (p ≤ 0.05) . Specifically, V 15 and V 20 in all six organs and V 5 , V 10 in the esophagus, heart, liver, and thyroid were significantly higher with photon CSI. Our patient cohort is the largest, to date, in which CSI with proton and photon therapies have been compared. This work adds to the body of literature that proton CSI reduces dose to normal tissue compared to photon CSI for pediatric patients who are at substantial risk for developing radiogenic late effects. Although the present study

  20. Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Green, Daniel M., E-mail: daniel.green@stjude.org [Department of Epidemiology and Cancer Control, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Billups, Catherine A. [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Stokes, Dennis C. [Department of Pediatrics, University of Tennessee School of Medicine, Memphis, Tennessee (United States); Broniscer, Alberto [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Bartels, Ute [Department of Haematology and Oncology, The Hospital for Sick Children, Toronto, Ontario (Canada); Chintagumpala, Murali [Department of Pediatric Medicine, Texas Children' s Cancer and Hematology Centers, Baylor College of Medicine, Houston, Texas (United States); Hassall, Timothy E. [Department of Haematology and Oncology, Royal Children' s Hospital, Brisbane (Australia); Gururangan, Sridharan [Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (United States); McCowage, Geoffrey B. [Department of Pediatrics, Children' s Hospital at Westmead, Sydney (Australia); Heath, John A. [Children' s Cancer Center, Royal Children' s Hospital Melbourne, Melbourne (Australia); Cohn, Richard J. [Department of Clinical Oncology, Sydney Children' s Hospital, Sydney (Australia); Fisher, Michael J. [Department of Pediatrics, Children' s Hospital of Philadelphia, Philadelphia, Pennsylvania (United States); Srinivasan, Ashok [Department of Bone Marrow Transplantation & Cellular Therapy, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Robinson, Giles W.; Gajjar, Amar [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2015-09-01

    Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV{sub 1}] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO{sub corr}]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m{sup 2} (IQR, 15.7-16.0 g/m{sup 2}). At 24 and 60 months ACT, DLCO{sub corr} was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV{sub 1} was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO{sub corr} was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO{sub corr} were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI

  1. Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Green, Daniel M.; Merchant, Thomas E.; Billups, Catherine A.; Stokes, Dennis C.; Broniscer, Alberto; Bartels, Ute; Chintagumpala, Murali; Hassall, Timothy E.; Gururangan, Sridharan; McCowage, Geoffrey B.; Heath, John A.; Cohn, Richard J.; Fisher, Michael J.; Srinivasan, Ashok; Robinson, Giles W.; Gajjar, Amar

    2015-01-01

    Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV 1 ] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO corr ]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m 2 (IQR, 15.7-16.0 g/m 2 ). At 24 and 60 months ACT, DLCO corr was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV 1 was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO corr was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO corr were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI. Continued monitoring of this cohort

  2. Impact of imatinib interruption and duration of prior hydroxyurea on the treatment outcome in patients with chronic myeloid leukemia: Single institution experience

    International Nuclear Information System (INIS)

    Edesa, W.A.; Abdel-malek, R.R.

    2015-01-01

    Background: Optimal response requires that patients should be maintained on the drug continuously. Objectives: To evaluate the influence of imatinib interruption and prior hydroxyurea use on the outcome of patients with chronic myeloid leukemia. Materials and methods: Between January 2010 and November 2013, patients with chronic phase who received imatinib at the Kasr Al-ainy Center of Clinical Oncology were included. Results: Sixty patients were included in this study, thirty three patients (55%) received imatinib upfront, while 27 (45%) received imatinib post hydroxyurea. Imatinib was not given regularly in 50% of patients. In terms of response, only major molecular response and complete molecular response were statistically significant in favor of patients who were receiving imatinib regularly compared to those who had interruption (ρ < 0.001, ρ < 0.001, respectively) , while there was no difference in patients stratified according to prior hydroxyurea. The median progression free survival was 30.3 months (95% CI 24.3–36.3). Among the group of patients who received imatinib regularly, progression free survival was longer (ρ = 0.049), there was no difference between those who received prior hydroxyurea versus those who did not (ρ = 0.67). Conclusion: Duration of prior hydroxyurea had no impact on response or progression free survival, while patients regular on imatinib had statistically significant difference with respect to major molecular response, complete molecular response and progression free survival compared to those who had periods of drug interruption, thus we need more governmental support to supply the drug without interruption to improve the outcome of therapy

  3. Receiving right/wrong feedback: consequences for learning.

    Science.gov (United States)

    Fazio, Lisa K; Huelser, Barbie J; Johnson, Aaron; Marsh, Elizabeth J

    2010-04-01

    Prior work suggests that receiving feedback that one's response was correct or incorrect (right/wrong feedback) does not help learners, as compared to not receiving any feedback at all (Pashler, Cepeda, Wixted, & Rohrer, 2005). In three experiments we examined the generality of this conclusion. Right/wrong feedback did not aid error correction, regardless of whether participants learned facts embedded in prose (Experiment 1) or translations of foreign vocabulary (Experiment 2). While right/wrong feedback did not improve the overall retention of correct answers (Experiments 1 and 2), it facilitated retention of low-confidence correct answers (Experiment 3). Reviewing the original materials was very useful to learners, but this benefit was similar after receiving either right/wrong feedback or no feedback (Experiments 1 and 2). Overall, right/wrong feedback conveys some information to the learner, but is not nearly as useful as being told the correct answer or having the chance to review the to-be-learned materials.

  4. Outcome of patients with intracranial non-germinomatous germ cell tumors-lessons from the SIOP-CNS-GCT-96 trial.

    Science.gov (United States)

    Calaminus, Gabriele; Frappaz, Didier; Kortmann, Rolf Dieter; Krefeld, Barbara; Saran, Frank; Pietsch, Torsten; Vasiljevic, Alexandre; Garre, Maria Luisa; Ricardi, Umberto; Mann, Jillian R; Göbel, Ulrich; Alapetite, Claire; Murray, Matthew J; Nicholson, James C

    2017-11-29

    Following promising results to increase survival and reduce treatment burden in intracranial non-germinomatous germ cell tumors (NGGCTs), we conducted a European study using dose-intense chemotherapy followed by risk-adapted radiotherapy. All patients received 4 courses of cisplatin/etoposide/ifosfamide. Non-metastatic patients then received focal radiotherapy only (54 Gy); metastatic patients received 30 Gy craniospinal radiotherapy with 24 Gy boost to primary tumor and macroscopic metastatic sites. Patients with localized malignant NGGCT (n = 116) demonstrated 5-year progression-free survival (PFS) and overall survival (OS) of 0.72 ± 0.04 and 0.82 ± 0.04, respectively. Primary tumor sites were: 67 pineal, 35 suprasellar, 5 bifocal, 9 others. One patient died postsurgery in clinical remission; 3 patients progressed during treatment and 27 (23%) relapsed afterward. Fourteen were local, 6 combined, and 7 distant relapses (outside radiation field). Seventeen of the 27 relapsed patients died of disease. Patients with metastatic disease (n = 33) demonstrated 5-year PFS and OS of 0.68 ± 0.09 and 0.75 ± 0.08, respectively; 1 patient died following progression on treatment and 9 (27%) relapsed afterward (5 local, 1 combined, 3 distant). Only one metastatic patient with recurrence was salvaged. Multivariate analysis identified diagnostic alpha-fetoprotein level (serum and/or cerebrospinal fluid level >1000 ng/mL, 19/149 patients, of whom 11 relapsed; P < 0.0003) and residual disease following treatment, including after second-look surgery (n = 52/145 evaluable patients, 26 relapsed; P = 0.0002) as significant prognostic indicators in this cohort. In localized malignant NGGCT, craniospinal radiotherapy could be avoided without increased relapses outside the radiotherapy field. Chemotherapy and craniospinal radiotherapy remain the gold standard for metastatic disease. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro

  5. Constrained noninformative priors

    International Nuclear Information System (INIS)

    Atwood, C.L.

    1994-10-01

    The Jeffreys noninformative prior distribution for a single unknown parameter is the distribution corresponding to a uniform distribution in the transformed model where the unknown parameter is approximately a location parameter. To obtain a prior distribution with a specified mean but with diffusion reflecting great uncertainty, a natural generalization of the noninformative prior is the distribution corresponding to the constrained maximum entropy distribution in the transformed model. Examples are given

  6. Anxiety and depression in patients receiving radiotherapy. Prospective study

    International Nuclear Information System (INIS)

    Chaturvedi, S.K.; Chandra, P.S.; Channabasavanna, S.M.; Anantha, N.; Reddy, B.K.M.; Sharma, S.

    1994-01-01

    The objective of this study was to detect the prevalence of anxiety and depressive disorders using the Hospital Anxiety and Depression Scale (HADS) prospectively in patients receiving Radiotherapy (RT) during and after treatment. 140 consecutive cancer patients referred for radiotherapy and their care givers were included. All patients were administered the Hospital Anxiety and Depression Scale (HADS) conducted at intake, just before starting RT, after finishing the course of RT, and at 3-4 months follow-up. Anxiety and depression are detected frequently in patients receiving RT both prior to treatment and later during follow-up

  7. Complete Versus Incomplete Angiography Prior to Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction.

    Science.gov (United States)

    Stiver, Kevin; Gao, Xu; Shreenivas, Satya; Boudoulas, Konstantinos Dean; Mazzaferri, Ernie; Makki, Nader; Lilly, Scott M

    2017-08-01

    Shorter reperfusion times in ST-elevation myocardial infarction (STEMI) are associated with improved survival. Prehospital strategies have been developed to minimize door-to-balloon (DTB) time, but few strategies within the catheterization laboratory itself have been evaluated. Incomplete angiography (IA) prior to percutaneous coronary intervention (PCI) is undertaken in clinical practice as a means to further reduce DTB time. We sought to determine whether or not those with STEMI who underwent IA prior to PCI had different preprocedural characteristics or post-PCI outcomes. We retrospectively reviewed patients presenting to our institution between March 2013 and December 2015. Clinical, demographic, and angiographic data were reviewed. The frequency, predictors, and outcomes among those who received IA vs complete angiography (CA) prior to PCI were compared with analysis of variance. Two hundred fifty-six patients were identified; 68 patients (26.6%) underwent IA and 188 patients (73.4%) had CA prior to PCI. Patients who received IA were younger, but no other preprocedural factors were predictive of IA. The practice of IA did vary by operator (range, 0%-47%; P<.01). DTB times were shorter in the IA group (28.1 min vs 37.3 min; P<.01). Overall outcomes, including peak troponin values, length of stay, in-hospital mortality, and discharge ejection fraction did not differ between the groups. IA is associated with shorter DTB times, although in this population was not associated with improvements in short-term outcomes.

  8. Enhanced cis-platinum ototoxicity in children with brain tumours who have received simultaneous or prior cranial irradiation

    International Nuclear Information System (INIS)

    Walker, D.A.; Pillow, J.; Waters, K.D.; Keir, E.

    1989-01-01

    We report on four children who received cis-platinum simultaneously with, or in one case 10 months after, cranial irradiation and experienced exaggerated ototoxicity affecting all audible frequencies. The hearing loss was severe, affecting the critical areas for speech perception, and necessitated the provision of bilateral hearing aids. The audiograms of these patients are shown and compared to those of four children who had received cis-platinum as part of their treatment for neuroblastoma but without cranial irradiation. The precipitation of the exaggerated hearing loss with the administration of cis-platinum in one patient 10 months after finishing cranial irradiation suggests that care should be taken in the timing of cis-platinum administration in relation to concurrent or previous cranial irradiation

  9. Pre-Irradiation Chemotherapy in High Risk Medulloblastoma

    International Nuclear Information System (INIS)

    Abd-El-Aal, H.

    2006-01-01

    Rationale: The present study evaluates the effect of pre-irradiation chemotherapy in pediatric patients with high risk medulloblastoma. Twenty-four (24) pediatric patients attended the pediatric unit of Kasr-EI-Aini Center of Radiation Oncology and Nuclear Medicine (NEMROCK) from January 2000 to January 2003. Patients and Methods: Our patients were 13 boys and II girls aged 3-12 years with a median of 6.5 years. According to Chang staging system 6 cases had T2, 14 cases had T3 A and 4 cases had T3 B, 20 cases were M0, 3 cases were M I and I case was M2. All patients were treated by initial surgery, 2 cycles of pre-irradiation chemotherapy followed by craniospinal radiation then by 4 cycles of post-radiation chemotherapy. Results: Fifteen out of the 20 patients with M0 had objective response (10CR + 5PR) and no one had disease progression after pre-irradiation chemotherapy. Among 4 patients with M0 disease, 2 patients had PR and 2 had S.D. There was no disease progression among patients who received pre-irradiation chemotherapy. The 3-year overall survival and 3-year progression-free survival; (PFS) were 50% and 51 %, respectively, Myelosuppression was the main toxic effect observed during pre-irradiation chemotherapy; however, there was no delay or interruption of craniospinal irradiation. Conclusion: Pre-irradiation chemotherapy is effective in high risk medulloblastoma and is associated with acceptable side effects. The delay in craniospinal irradiation (CSI) for about 5 weeks to receive 2 courses of chemotherapy will not significantly increase disease progression. Multiple cycles of post-irradiation chemotherapy can be given safely after C51. A larger number of patients and longer follow-up is needed to confirm the results

  10. Reasons for receiving or not receiving HPV vaccination in primary schoolgirls in Tanzania: a case control study.

    Directory of Open Access Journals (Sweden)

    Deborah Watson-Jones

    Full Text Available There are few data on factors influencing human papillomavirus (HPV vaccination uptake in sub-Saharan Africa. We examined the characteristics of receivers and non-receivers of HPV vaccination in Tanzania and identified reasons for not receiving the vaccine.We conducted a case control study of HPV vaccine receivers and non-receivers within a phase IV cluster-randomised trial of HPV vaccination in 134 primary schools in Tanzania. Girls who failed to receive vaccine (pupil cases and their parents/guardians (adult cases and girls who received dose 1 (pupil controls of the quadrivalent vaccine (Gardasil™ and their parents/guardians (adult controls were enrolled from 39 schools in a 1∶1 ratio and interviewed about cervical cancer, HPV vaccine knowledge and reasons why they might have received or not received the vaccine. Conditional logistic regression was used to determine factors independently associated with not receiving HPV vaccine.We interviewed 159 pupil/adult cases and 245 pupil/adult controls. Adult-factors independently associated with a daughter being a case were older age, owning fewer household items, not attending a school meeting about HPV vaccine, and not knowing anyone with cancer. Pupil-factors for being a case included having a non-positive opinion about the school de-worming programme, poor knowledge about the location of the cervix, and not knowing that a vaccine could prevent cervical cancer. Reasons for actively refusing vaccination included concerns about side effects and infertility. Most adult and pupil cases reported that they would accept the HPV vaccine if it were offered again (97% and 93% respectively.Sensitisation messages, especially targeted at older and poorer parents, knowledge retention and parent meetings are critical for vaccine acceptance in Tanzania. Vaccine side effects and fertility concerns should be addressed prior to a national vaccination program. Parents and pupils who initially decline vaccination

  11. Measured Neutron Spectra and Dose Equivalents From a Mevion Single-Room, Passively Scattered Proton System Used for Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Rebecca M., E-mail: rhowell@mdanderson.org [Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Burgett, Eric A.; Isaacs, Daniel [Department of Nuclear Engineering, Idaho State University, Pocatello, Idaho (United States); Price Hedrick, Samantha G.; Reilly, Michael P.; Rankine, Leith J.; Grantham, Kevin K.; Perkins, Stephanie; Klein, Eric E. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States)

    2016-05-01

    Purpose: To measure, in the setting of typical passively scattered proton craniospinal irradiation (CSI) treatment, the secondary neutron spectra, and use these spectra to calculate dose equivalents for both internal and external neutrons delivered via a Mevion single-room compact proton system. Methods and Materials: Secondary neutron spectra were measured using extended-range Bonner spheres for whole brain, upper spine, and lower spine proton fields. The detector used can discriminate neutrons over the entire range of the energy spectrum encountered in proton therapy. To separately assess internally and externally generated neutrons, each of the fields was delivered with and without a phantom. Average neutron energy, total neutron fluence, and ambient dose equivalent [H* (10)] were calculated for each spectrum. Neutron dose equivalents as a function of depth were estimated by applying published neutron depth–dose data to in-air H* (10) values. Results: For CSI fields, neutron spectra were similar, with a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate continuum between the evaporation and thermal peaks. Neutrons in the evaporation peak made the largest contribution to dose equivalent. Internal neutrons had a very low to negligible contribution to dose equivalent compared with external neutrons, largely attributed to the measurement location being far outside the primary proton beam. Average energies ranged from 8.6 to 14.5 MeV, whereas fluences ranged from 6.91 × 10{sup 6} to 1.04 × 10{sup 7} n/cm{sup 2}/Gy, and H* (10) ranged from 2.27 to 3.92 mSv/Gy. Conclusions: For CSI treatments delivered with a Mevion single-gantry proton therapy system, we found measured neutron dose was consistent with dose equivalents reported for CSI with other proton beamlines.

  12. Association of prior HPV vaccination with reduced preterm birth: A population based study.

    Science.gov (United States)

    Lawton, Beverley; Howe, Anna S; Turner, Nikki; Filoche, Sara; Slatter, Tania; Devenish, Celia; Hung, Noelyn Anne

    2018-01-02

    Emerging evidence suggests that HPV infection is associated with negative pregnancy outcomes such as preterm birth (PTB), and pre-eclampsia. We aimed to determine if prior HPV vaccination reduced adverse pregnancy outcomes. A New Zealand population-based retrospective study linking first pregnancy outcome data (2008-2014 n = 35,646) with prior quadrivalent HPV vaccination status. Primary outcomes were likelihood (odds ratios, ORs) of PTB, pre-eclampsia, and stillbirth. Exposure groups were based on HPV vaccination. Adjusted ORs were calculated for each outcome, controlling for mother's age at delivery, ethnicity, socioeconomic status, health board region at time of delivery, and body mass index and smoking status at time of registration with maternity care provider. Mother's mean age at delivery was 19 (SD 2.1) years. Of 34,994 the pregnancies included in the final study analyses 62.3% of women were unvaccinated, 11.0% vaccinated with one or two doses and 27.7% vaccinated with three doses prior to pregnancy. PTB (OR: 0.87; CI 0.78, 0.96)) was significantly lower for women who previously received the HPV vaccine. A dose response effect was found with each successive dose received decreasing the likelihood of PTB. No associations between the vaccinated and unvaccinated groups were shown for pre-eclampsia or stillbirth. Prior receipt of the quadrivalent HPV vaccine was associated with a significant reduction in PTB (13%); suggesting that HPV vaccination may be effective in reducing PTB. The potential global public health impact is considerable and there is urgency to undertake further research to replicate and explore these findings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Prior exposure to interpersonal violence and long-term treatment response for boys with a disruptive behavior disorder.

    Science.gov (United States)

    Shenk, Chad E; Dorn, Lorah D; Kolko, David J; Rausch, Joseph R; Insana, Salvatore P

    2014-10-01

    Interpersonal violence (IPV) is common in children with a disruptive behavior disorder (DBD) and increases the risk for greater DBD symptom severity, callous-unemotional (CU) traits, and neuroendocrine disruption. Thus, IPV may make it difficult to change symptom trajectories for families receiving DBD interventions given these relationships. The current study examined whether IPV prior to receiving treatment for a DBD predicted trajectories of a variety of associated outcomes, specifically DBD symptoms, CU traits, and cortisol concentrations. Boys with a DBD diagnosis (N = 66; age range = 6-11 years; 54.5% of whom experienced IPV prior to treatment) of either oppositional defiant disorder or conduct disorder participated in a randomized clinical trial and were assessed 3 years following treatment. Multilevel modeling demonstrated that prior IPV predicted smaller rates of change in DBD symptoms, CU traits, and cortisol trajectories, indicating less benefit from intervention. The effect size magnitudes of IPV were large for each outcome (d = 0.88-1.07). These results suggest that IPV is a predictor of the long-term treatment response for boys with a DBD. Including trauma-focused components into existing DBD interventions may be worth testing to improve treatment effectiveness for boys with a prior history of IPV. Copyright © 2014 International Society for Traumatic Stress Studies.

  14. Quality of assessment of prior learning in university programmes : Perceptions of candidates, tutors and assessors

    NARCIS (Netherlands)

    Desirée Joosten-ten Brinke; W. Jochems; Dominique Sluijsmans

    2009-01-01

    Formal diplomas and certificates have been accepted as proof that students may receive exemption for parts of their educational programme. Nowadays, though, it is socially desirable that informal and non-formal learning experiences are also recognised. Assessment of prior learning (APL) addresses

  15. Compressed Sensing-Based Direct Conversion Receiver

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas; Larsen, Torben

    2012-01-01

    Due to the continuously increasing computational power of modern data receivers it is possible to move more and more processing from the analog to the digital domain. This paper presents a compressed sensing approach to relaxing the analog filtering requirements prior to the ADCs in a direct......-converted radio signals. As shown in an experiment presented in the article, when the proposed method is used, it is possible to relax the requirements for the quadrature down-converter filters. A random sampling device and an additional digital signal processing module is the price to pay for these relaxed...

  16. Impact of imatinib interruption and duration of prior hydroxyurea on the treatment outcome in patients with chronic myeloid leukemia: Single institution experience.

    Science.gov (United States)

    Edesa, Wael Abdelgawad; Abdel-malek, Raafat Ragaey

    2015-06-01

    Optimal response requires that patients should be maintained on the drug continuously. To evaluate the influence of imatinib interruption and prior hydroxyurea use on the outcome of patients with chronic myeloid leukemia. Between January 2010 and November 2013, patients with chronic phase who received imatinib at the Kasr Al-ainy Center of Clinical Oncology were included. Sixty patients were included in this study, thirty three patients (55%) received imatinib upfront, while 27 (45%) received imatinib post hydroxyurea. Imatinib was not given regularly in 50% of patients. In terms of response, only major molecular response and complete molecular response were statistically significant in favor of patients who were receiving imatinib regularly compared to those who had interruption (phydroxyurea. The median progression free survival was 30.3 months (95% CI 24.3-36.3). Among the group of patients who received imatinib regularly, progression free survival was longer (p=0.049), there was no difference between those who received prior hydroxyurea versus those who did not (p=0.67). Duration of prior hydroxyurea had no impact on response or progression free survival, while patients regular on imatinib had statistically significant difference with respect to major molecular response, complete molecular response and progression free survival compared to those who had periods of drug interruption, thus we need more governmental support to supply the drug without interruption to improve the outcome of therapy. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  17. SU-F-T-435: Helical Tomotherapy for Craniospinal Irradiation: What We Have Learned from a Multi-Institutional Study

    Energy Technology Data Exchange (ETDEWEB)

    Du, D; Kaprealian, T; Low, D; Qi, X [University of California Los Angeles, Los Angeles, CA (United States); Han, C [City of Hope National Medical Center, Los Angeles, CA (United States); Chen, J; Perez-Andujar, A [University of California San Francisco, Lafayette, CA (United States); Lee, B [University of California, Los Angeles, Los Angeles, CA (United States)

    2016-06-15

    Purpose: To report cranio-spinal irradiation (CSI) planning experience, compare dosimetric quality and delivery efficiency with Tomotherapy from different institutions, and to investigate effect of planning parameters on plan quality and treatment time. Methods: Clinical helical tomotherapy IMRT plans for thirty-nine CSI cases from three academic institutions were retrospectively evaluated. The planning parameters: field width (FW), pitch, modulation factor (MF), and achieved dosimetric endpoints were cross-compared. A fraction-dose-delivery-timing index (FDTI), defined as treatment time per fraction dose per PTV length, was utilized to evaluate plan delivery efficiency. A lower FDTI indicates higher delivery efficiency. We studied the correlation between planning quality, treatment time and planning parameters by grouping the plans under specific planning parameters. Additionally, we created new plans using 5cm jaw for a subset of plans that used 2.5cm jaw to exam if treatment efficiency can be improved without sacrificing plan quality. Results: There were significant dosimetric differences for organ at risks (OARs) among different institutions (A,B,C). Using the lowest average MF (1.9±0.4) and 5cm field width, C had the highest lung, heart, kidney, liver mean doses and maximum doses for lens. Using the same field width of 5cm, but higher MF (2.6±0.6), B had lower doses to the OARs in the thorax and abdomen area. Most of A’s plans were planned with 2.5cm jaw, the plans yielded better PTV coverage, higher OAR doses and slightly shorter FDTI compared to institution B. The replanned 5cm jaw plans achieved comparable PTV coverage and OARs sparing, while saving up to 44.7% treatment time. Conclusion: Plan quality and delivery efficiency could vary significantly in CSI planning on Tomotheapy due to choice of different planning parameters. CSI plans using a 5cm jaw, with proper selection of pitch and MF, can achieve comparable/ better plan quality with shorter

  18. SU-F-T-429: Craniospinal Irradiation by VMAT Technique: Impact of FFF Beam and High Resolution MLC On Plan Quality

    Energy Technology Data Exchange (ETDEWEB)

    Ganesh, T; Sarkar, B; Munshi, A; Mohanti, B [Fortis Memorial Research Institute, Gurgaon, Haryana (India)

    2016-06-15

    Purpose: Objective of this study was to evaluate the impact of using flattening filter free (FFF) beam with 0.5 cm multileaf collimator (MLC) leaves over conventional flattened beam with 1 cm leaf width MLC on the treatment plan quality in cranio-spinal irradiation (CSI). Methods: For five medulloblastoma cases (3 males and 2 females), who were previously treated by volumetric modulated arc therapy (VMAT) technique using conventional flattened beam shaped by 1 cm width MLC leaves, four test plans were generated and compared against the delivered plan. These retrospective plans consisted of four different combinations of flattened and FFF beams from Elekta’s Agility treatment head with 0.5 cm width MLC leaves. Sparing of organs at risks (OAR) in terms of dose to 5%, 50%, 75% and 90% volumes, mean and maximum dose were evaluated. Results: All plans satisfied the planning objective of covering 95% of PTV by at least 95% of prescription dose. Marginal variation of dose spillage was observed between different VMAT plans at very low dose range (1–5 Gy). Variation in dose statistics for PTVs and OARs were within 1% or 1 Gy. Amongst the five plans, the plan with flattened beam with 1 cm MLC had the highest number of MUs, 2.13 times higher than the plan with Agility MLC with FFF beam that had the least number of MUs. No statistically significant difference (p≥0.05) was observed between the reference plan and the retrospectively generated plans in terms of PTV coverage, cold spot, hot spot and organ at risk doses. Conclusion: In the treatment of CSI cases by VMAT technique, FFF beams and/or finer width MLC did not exhibit advantage over the flattened beams or wider MLC in terms of plan quality except for reduction in MUs.

  19. Impact of Fluoroquinolone Exposure Prior to Tuberculosis Diagnosis on Clinical Outcomes in Immunocompromised Patients.

    Science.gov (United States)

    Lee, Ju Young; Lee, Hyun Jung; Kim, Yong Kyun; Yu, Shinae; Jung, Jiwon; Chong, Yong Pil; Lee, Sang-Oh; Choi, Sang-Ho; Shim, Tae Sun; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

    2016-07-01

    There have been concerns about an association of fluoroquinolone (FQ) use prior to tuberculosis (TB) diagnosis with adverse outcomes. However, FQ use might prevent clinical deterioration in missed TB patients, especially in those who are immunocompromised, until they receive definitive anti-TB treatment. All adult immunocompromised patients with smear-negative and culture-positive TB at a tertiary care hospital in Korea over a 2-year period were included in this study. Long-term FQ (≥7 days) use was defined as exposure to FQ for at least 7 days prior to TB diagnosis. A total of 194 patients were identified: 33 (17%) in the long-term FQ group and 161 (83%) in the comparator, including a short-term FQ group (n = 23), non-FQ group (n = 78), and a group receiving no antibiotics (n = 60). Patients in the long-term FQ group presented with atypical chest radiologic pattern more frequently than those in the comparator (77% [24/31] versus 46% [63/138]; P = 0.001). The median time from mycobacterial test to positive mycobacterial culture appeared to be longer in the long-term FQ group (8.1 weeks versus 7.7 weeks; P = 0.09), although the difference was not statistically significant. Patients in the long-term FQ group were less likely to receive empirical anti-TB treatment (55% versus 74%; P = 0.03). The median time from mycobacterial test to anti-TB therapy was longer in the long-term FQ group (4.6 weeks versus 2.2 weeks; P 0.99) or in the 30-day (6% versus 6%; P > 0.99) or 90-day (12% versus 12%; P > 0.99) mortality rate between the two groups. FQ exposure (≥7 days) prior to TB diagnosis in immunocompromised patients appears not to be associated with adverse outcomes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  20. Outcomes and Acute Toxicities of Proton Therapy for Pediatric Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System

    International Nuclear Information System (INIS)

    McGovern, Susan L.; Okcu, M. Fatih; Munsell, Mark F.; Kumbalasseriyil, Nancy; Grosshans, David R.; McAleer, Mary F.; Chintagumpala, Murali; Khatua, Soumen; Mahajan, Anita

    2014-01-01

    Purpose: Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a rare cancer primarily affecting children younger than 5 years old. Because patients are young and receive intensive chemotherapy, there is concern regarding late radiation toxicity, particularly as survival rates improve. Therefore, there is interest in using proton therapy to treat these tumors. This study was undertaken to investigate outcomes and acute toxicities associated with proton therapy for AT/RT. Methods and Materials: The records of 31 patients with AT/RT treated with proton radiation from October 2008 to August 2013 were reviewed. Demographics, treatment characteristics, and outcomes were recorded and analyzed. Results: Median age at diagnosis was 19 months (range, 4-55 months), with a median age at radiation start of 24 months (range, 6-62 months). Seventeen patients received local radiation with a median dose of 50.4 GyRBE (range, 9-54 GyRBE). Fourteen patients received craniospinal radiation; half received 24 GyRBE or less, and half received 30.6 GyRBE or more. For patients receiving craniospinal radiation, the median tumor dose was 54 GyRBE (range, 43.2-55.8 GyRBE). Twenty-seven patients (87%) completed the planned radiation. With median follow-up of 24 months for all patients (range, 3-53 months), median progression-free survival was 20.8 months and median overall survival was 34.3 months. Five patients (16%) developed clinical findings and imaging changes in the brainstem 1 to 4 months after radiation, consistent with radiation reaction; all cases resolved with steroids or bevacizumab. Conclusions: This is the largest report of children with AT/RT treated with proton therapy. Preliminary survival outcomes in this young pediatric population are encouraging compared to historic results, but further study is warranted

  1. Outcomes and Acute Toxicities of Proton Therapy for Pediatric Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    McGovern, Susan L., E-mail: slmcgove@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Okcu, M. Fatih [Texas Children' s Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kumbalasseriyil, Nancy; Grosshans, David R.; McAleer, Mary F. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chintagumpala, Murali [Texas Children' s Hematology and Oncology Centers, Department of Pediatrics, Baylor College of Medicine, Houston, Texas (United States); Khatua, Soumen [Department of Pediatrics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mahajan, Anita [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2014-12-01

    Purpose: Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system is a rare cancer primarily affecting children younger than 5 years old. Because patients are young and receive intensive chemotherapy, there is concern regarding late radiation toxicity, particularly as survival rates improve. Therefore, there is interest in using proton therapy to treat these tumors. This study was undertaken to investigate outcomes and acute toxicities associated with proton therapy for AT/RT. Methods and Materials: The records of 31 patients with AT/RT treated with proton radiation from October 2008 to August 2013 were reviewed. Demographics, treatment characteristics, and outcomes were recorded and analyzed. Results: Median age at diagnosis was 19 months (range, 4-55 months), with a median age at radiation start of 24 months (range, 6-62 months). Seventeen patients received local radiation with a median dose of 50.4 GyRBE (range, 9-54 GyRBE). Fourteen patients received craniospinal radiation; half received 24 GyRBE or less, and half received 30.6 GyRBE or more. For patients receiving craniospinal radiation, the median tumor dose was 54 GyRBE (range, 43.2-55.8 GyRBE). Twenty-seven patients (87%) completed the planned radiation. With median follow-up of 24 months for all patients (range, 3-53 months), median progression-free survival was 20.8 months and median overall survival was 34.3 months. Five patients (16%) developed clinical findings and imaging changes in the brainstem 1 to 4 months after radiation, consistent with radiation reaction; all cases resolved with steroids or bevacizumab. Conclusions: This is the largest report of children with AT/RT treated with proton therapy. Preliminary survival outcomes in this young pediatric population are encouraging compared to historic results, but further study is warranted.

  2. Recall of UVB-induced erythema in breast cancer patient receiving multiple drug chemotherapy

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Lindskov, R

    1984-01-01

    One day after sunbathing, a breast cancer patient received intravenous methotrexate, cyclophosphamide and 5-fluorouracil and had a recall of her UV erythema over the following week. Phototesting with UVA and UVB prior to and after a subsequent chemotherapy treatment showed a UVB-induced recall...

  3. Secukinumab treatment of moderate to severe plaque psoriasis in routine clinical care: real-life data of prior and concomitant use of psoriasis treatments from the PROSPECT study.

    Science.gov (United States)

    Körber, A; Thaçi, D; von Kiedrowski, R; Bachhuber, T; Melzer, N; Kasparek, T; Kraehn-Senftleben, G; Amon, U; Augustin, M

    2018-03-01

    Secukinumab, a fully human anti-interleukin-17A monoclonal antibody, has demonstrated efficacy and safety in patients with moderate to severe psoriasis. However, as per study protocols, transition periods from prior psoriasis treatments of a defined minimal length were required and use of concomitant psoriasis medication was prohibited. There is therefore a lack of data on the effect of shorter transition periods and concomitant psoriasis treatment with other pharmacologically active substances on the effectiveness and safety of secukinumab in routine clinical practice. The PROSPECT study was designed to assess prior and concomitant use of psoriasis treatments in subjects receiving secukinumab and the duration of transition periods from prior treatments to secukinumab. Here, we report the baseline characteristics and the duration of transition period in an interim analysis of the first 805 subjects. PROSPECT is an ongoing 24-week, single-cohort, non-interventional study. Subjects with moderate to severe psoriasis with a decision to receive secukinumab were included. The majority of subjects were male (491/796, 61.7%), with a mean age of 47.7 years (SD 13.7). The baseline Psoriasis Area and Severity Index (PASI) was available for 92.4% (744/805) of subjects, and mean baseline PASI was 17.5 (SD 13.1); 93.4% (752/805) of subjects had signs of high disease severity. Use of concomitant treatment increased with the number of signs. Within the last 12 months prior to inclusion, 10%, 40%, and 28% of subjects had received topical, conventional systemic, or biologic treatments as their last prior psoriasis therapy, respectively, and 22% of subjects had not received any psoriasis therapy. Discontinuation of prior treatment due to adverse events was high in subjects with conventional systemic treatment (93/413, 22.5%) compared to biologic treatment (5/210, 2.4%). The median duration of the transition period was 14.0, 30.5, and 38.0 days for prior topical, conventional systemic

  4. A Simulation of Pell Grant Awards and Costs Using Prior-Prior Year Financial Data

    Science.gov (United States)

    Kelchen, Robert; Jones, Gigi

    2015-01-01

    We examine the likely implications of switching from a prior year (PY) financial aid system, the current practice in which students file the Free Application for Federal Student Aid (FAFSA) using income data from the previous tax year, to prior-prior year (PPY), in which data from two years before enrollment is used. While PPY allows students to…

  5. Ovarian function in survivors of childhood medulloblastoma: Impact of reduced dose craniospinal irradiation and high-dose chemotherapy with autologous stem cell rescue.

    Science.gov (United States)

    Balachandar, Sadana; Dunkel, Ira J; Khakoo, Yasmin; Wolden, Suzanne; Allen, Jeffrey; Sklar, Charles A

    2015-02-01

    Data on ovarian function (OvF) in medulloblastoma (MB) survivors is limited, with most studies describing outcomes in survivors treated with craniospinal irradiation (CSI) doses >24 Gy ± standard chemotherapy. The objective of the current study is to report on OvF: (i) across a range of CSI doses; and (ii) following high-dose chemotherapy with autologous stem cell rescue (ASCR). Retrospective review of female MB survivors who were diagnosed in childhood and followed at Memorial Sloan Kettering Cancer Center. Patients were divided into three groups: (i) CSI ≤24 Gy +/- standard chemotherapy; (ii) CSI ≥35 Gy +/- standard chemotherapy; and (iii) high-dose chemotherapy with ASCR +/- CSI. Primary ovarian dysfunction (POD) occurred in 2/17 subjects in group 1, 3/9 subjects in group 2 and 5/5 subjects in group 3 (P < 0.01). Normalization of function was noted in four subjects with POD. Persistent POD requiring hormone replacement (POF) was observed in 1/17 subjects in group 1, 2/9 in group 2, and 3/5 in group 3 (P = 0.02). Neither age at treatment nor type of standard chemotherapy correlated with risk of POD or POF. Both POD and POF appear to occur in a small proportion of patients who are treated with contemporary doses of CSI +/- standard chemotherapy. However, ovarian dysfunction requiring hormone replacement therapy is common following high-dose chemotherapy associated with ASCR. These findings will assist clinicians in counseling patients regarding fertility preservation and risk of impaired ovarian function/future fertility. Pediatr Blood Cancer 2015;62:317-321. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  6. Electronic warfare receivers and receiving systems

    CERN Document Server

    Poisel, Richard A

    2014-01-01

    Receivers systems are considered the core of electronic warfare (EW) intercept systems. Without them, the fundamental purpose of such systems is null and void. This book considers the major elements that make up receiver systems and the receivers that go in them.This resource provides system design engineers with techniques for design and development of EW receivers for modern modulations (spread spectrum) in addition to receivers for older, common modulation formats. Each major module in these receivers is considered in detail. Design information is included as well as performance tradeoffs o

  7. SU-F-T-446: Improving Craniospinal Irradiation Technique Using Volumetric Modulated Arc Therapy (VMAT) Planning and Its Dosimetric Verification

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X; Tejani, M; Jiang, X; Elder, E; Dhabaan, A [Emory University, Atlanta, GA (United States)

    2016-06-15

    Purpose: The purpose of this study is to investigate a volumetric modulated arc therapy (VMAT) treatment planning technique for supine craniospinal irradiation (CSI). Evaluate the suitability of VMAT for CSI with dosimetric measurements and compare it to 3D conformal planning using specific plan metrics such as dose conformity, homogeneity, and dose of organs at risk (OAR). Methods: Ten CSI patients treated with conventional 3D technique were re-planned with VMAT. The PTV was contoured to include the whole contents of the brain and spinal canal with a uniform margin of 5 mm. VMAT plans were generated with two partial arcs covering the brain, two partial arcs for the superior portion of the spinal cord and two partial arcs covering the remaining inferior portion of the spinal cord. Conformity index (CI), heterogeneity indexes (HI) and max and mean doses of OAR were compared to 3D plans. VMAT plans were delivered onto an anthropomorphic phantom loaded with Gafchromic films and OSLDs placed at specific positions to evaluate the plan dose at the junctions and as well as the plan dose distributions. Results: This VMAT technique was validated with a clinical study of 10 patients. The average CI was 1.03±0.02 for VMAT plans and 1.96±0.32 for conformal plans. And the average HI was 1.15±0.01 for VMAT plans and 1.51±0.21 for conformal plans. The mean and max doses to the all OARs for VMAT plans were significantly lower than conformal plans. The measured dose in phantom for VAMT plans was comparable to the calculated dose in Eclipse and the doses at junctions were verified. Conclusion: VMAT CSI was able to achieve better dose conformity and heterogeneity as well as significantly reducing the dose to Heart, esophagus and larynx. VMAT CSI appears to be a dosimterically advantageous, faster delivery, has better reproducibility CSI treatment.

  8. Combining inter-source seismic interferometry and source-receiver interferometry for deep local imaging

    NARCIS (Netherlands)

    Liu, Y.; Arntsen, B.; Wapenaar, C.P.A.; Van der Neut, J.R.

    2014-01-01

    The virtual source method has been applied successfully to retrieve the impulse response between pairs of receivers in the subsurface. This method is further improved by an updown separation prior to the crosscorrelation to suppress the reflections from the overburden and the free surface. In a

  9. Use of prior mammograms in the classification of benign and malignant masses

    International Nuclear Information System (INIS)

    Varela, Celia; Karssemeijer, Nico; Hendriks, Jan H.C.L.; Holland, Roland

    2005-01-01

    The purpose of this study was to determine the importance of using prior mammograms for classification of benign and malignant masses. Five radiologists and one resident classified mass lesions in 198 mammograms obtained from a population-based screening program. Cases were interpreted twice, once without and once with comparison of previous mammograms, in a sequential reading order using soft copy image display. The radiologists' performances in classifying benign and malignant masses without and with previous mammograms were evaluated with receiver operating characteristic (ROC) analysis. The statistical significance of the difference in performances was calculated using analysis of variance. The use of prior mammograms improved the classification performance of all participants in the study. The mean area under the ROC curve of the readers increased from 0.763 to 0.796. This difference in performance was statistically significant (P = 0.008)

  10. Thrombolysis outcomes in acute ischemic stroke patients with prior stroke and diabetes mellitus

    DEFF Research Database (Denmark)

    Mishra, N K; Ahmed, N; Davalos, A

    2011-01-01

    BACKGROUND: Patients with concomitant diabetes mellitus (DM) and prior stroke (PS) were excluded from European approval of alteplase in stroke. We examined the influence of DM and PS on the outcomes of patients who received thrombolytic therapy (T; data from Safe Implementation of Thrombolysis......,986), or concomitant DM and PS (OR 1.23 [0.996-1.52], p = 0.05, n = 1,136), all CMH p treatment (tissue...

  11. Influence of a CIDR prior to bull breeding on pregnancy rates and subsequent calving distribution.

    Science.gov (United States)

    Lamb, G C; Dahlen, C R; Vonnahme, K A; Hansen, G R; Arseneau, J D; Perry, G A; Walker, R S; Clement, J; Arthington, J D

    2008-11-01

    We determined whether insertion of a CIDR for 7 days prior to the breeding season enhanced pregnancy rates and altered the date of conception in suckled beef cows mated naturally. Suckled beef cows (n=2033) from 15 locations were randomly assigned to one of two treatments: (1) cows received a CIDR 7 days prior to the breeding season for 7 days (CIDR; n=999); (2) cows received no treatment (Control; n=1034). On the first day of the breeding season bulls were introduced to herds at a rate of 15-25 cows per yearling bull or 20-30 cows per mature bull. Pregnancy status and the date of conception were determined via transrectal ultrasonography at 56 and 120 days after initiation of the breeding season. Overall pregnancy rates ranged from 59.3 to 98.9% among the 15 locations. The percentage of cows becoming pregnant during the first 30 days of the breeding season was similar between CIDR (68.2%) and Control (66.7%) cows, and overall pregnancy rates were similar between CIDR (88.9%) and Control (88.6%) cows. The average day of conception after initiation of the breeding season was shorter (Pbody condition score and nor parity affected pregnancy rates or days to conception, whereas pregnancy rates and days to conception were affected (Pconception were greater for cows that calved within 40 days (31.6+/-1.2 days) of initiation of the breeding season compared to cows calving between 40 and 50 days (25.3+/-1.2 days) prior to initiation of the breeding season, which were greater than those cows calving between 50-60 days (20.0+/-0.8 days) and 60-70 days (21.3+/-1.0 days) prior to initiation of the breeding season. Cows calving greater than 70 days (17.3+/-1.5 days) from initiation of the breeding season had the shortest interval to conception. We concluded that insertion of a CIDR prior to the breeding season failed to increase overall pregnancy rates, but did influence the average day of conception.

  12. Sportmen’s experiences at a somatology clinic receiving a sport message

    Directory of Open Access Journals (Sweden)

    Karien Jooste

    2013-06-01

    Full Text Available Sportsmen are increasingly visiting somatology clinics for massages prior to an aerobic sports event. Massage is frequently utilised prior to an athletic activity, as a means of enhancing performance. Massage is known to have both calming and stimulating properties, thereby possessing the potential to benefit performance in numerous different circumstances. In the context of sportsmen visiting somatology clinics, it is unclear how men experienced the benefits of a massage by a therapist in the somatology environment, prior to participating in an aerobic sports event. The purpose of this qualitative, exploratory, descriptive and contextual study was to explore and describe the experiences of men regarding sports massage in a somatology clinic prior to an aerobic sports event. Purposive sampling was used to select eight (8 men, aged between 25 and 50 years, who received two massages within two weeks prior to participating in an aerobic sports event. The data were collected through in-depth, unstructured, individual interviews and field notes until saturation of data was achieved. Trustworthiness was ensured by utilising the principles of Lincoln and Guba’s model. The men experienced the sports massage as relaxing and giving perceived holistic beneficial effects. They described their experience during the massage and during and after participation in an aerobic sports event. A sports massage brings about psychological, physical, and spiritual effects during and after participation in an aerobic sports event.

  13. Does prior coronary artery bypass surgery alter the gender gap in patients presenting with acute coronary syndrome? A 20-year retrospective cohort study.

    Science.gov (United States)

    Al-Aqeedi, Rafid Fayadh; Al Suwaidi, Jassim; Singh, Rajvir; Al Binali, Hajar A

    2012-01-01

    Previous studies demonstrated women presenting with acute coronary syndrome (ACS) have poor outcomes when compared with men 'the gender gap phenomenon'. The impact of prior coronary artery bypass graft (CABG) on women presenting with ACS is unknown. We hypothesised that the gender gap is altered in ACS patients with prior CABG. The aim of this study was to evaluate patients presenting with ACS according to their gender and history of prior CABG. Retrospective, observational (cohort) study. Data were collected from hospital-based registry of patients hospitalised with ACS in Doha, Qatar, from 1991 through 2010. The data were analysed according to their gender and history of prior CABG. A total of 16 750 consecutive patients with ACS were studied. In total, 693 (4.3%) patients had prior CABG; among them 125 (18%) patients were women. Comparisons of clinical characteristics, inhospital treatment, and outcomes, including inhospital mortality and stroke were made. Women with or without prior CABG were older, less likely to be smokers, but more likely to have diabetes mellitus (DM), hypertension and renal impairment than men (p=0.001). Women were less likely to receive reperfusion and early invasive therapies. When compared with men, women without prior CABG carried higher inhospital mortality (11% vs 4.9%; p=0.001) and stroke rates (0.9% vs 0.3%; p=0.001). Female gender was independent predictor of poor outcome. Among prior CABG patients, despite the fact that women had worse baseline characteristics and were less likely to receive evidence-based therapy, there were no significant differences in mortality or stroke rates between the two groups. Consistent with the world literature, women presenting with ACS and without prior CABG had higher death rates compared with men. Patients with prior CABG had comparable death rates regardless of the gender status.

  14. Chromosomal differences between acute nonlymphocytic leukemia in patients with prior solid tumors and prior hematologic malignancies. A study of 14 cases with prior breast cancer

    International Nuclear Information System (INIS)

    Mamuris, Z.; Dumont, J.; Dutrillaux, B.; Aurias, A.

    1989-01-01

    A cytogenetic study of 14 patients with secondary acute nonlymphocytic leukemia (S-ANLL) with prior treatment for breast cancer is reported. The chromosomes recurrently involved in numerical or structural anomalies are chromosomes 7, 5, 17, and 11, in decreasing order of frequency. The distribution of the anomalies detected in this sample of patients is similar to that observed in published cases with prior breast or other solid tumors, though anomalies of chromosome 11 were not pointed out, but it significantly differs from that of the S-ANLL with prior hematologic malignancies. This difference is principally due to a higher involvement of chromosome 7 in patients with prior hematologic malignancies and of chromosomes 11 and 17 in patients with prior solid tumors. A genetic determinism involving abnormal recessive alleles located on chromosomes 5, 7, 11, and 17 uncovered by deletions of the normal homologs may be a cause of S-ANLL. The difference between patients with prior hematologic malignancies or solid tumors may be explained by different constitutional mutations of recessive genes in the two groups of patients

  15. Detection of architectural distortion in prior screening mammograms using Gabor filters, phase portraits, fractal dimension, and texture analysis

    International Nuclear Information System (INIS)

    Rangayyan, Rangaraj M.; Prajna, Shormistha; Ayres, Fabio J.; Desautels, J.E.L.

    2008-01-01

    Mammography is a widely used screening tool for the early detection of breast cancer. One of the commonly missed signs of breast cancer is architectural distortion. The purpose of this study is to explore the application of fractal analysis and texture measures for the detection of architectural distortion in screening mammograms taken prior to the detection of breast cancer. A method based on Gabor filters and phase portrait analysis was used to detect initial candidates for sites of architectural distortion. A total of 386 regions of interest (ROIs) were automatically obtained from 14 ''prior mammograms'', including 21 ROIs related to architectural distortion. From the corresponding set of 14 ''detection mammograms'', 398 ROIs were obtained, including 18 related to breast cancer. For each ROI, the fractal dimension and Haralick's texture features were computed. The fractal dimension of the ROIs was calculated using the circular average power spectrum technique. The average fractal dimension of the normal (false-positive) ROIs was significantly higher than that of the ROIs with architectural distortion (p = 0.006). For the ''prior mammograms'', the best receiver operating characteristics (ROC) performance achieved, in terms of the area under the ROC curve, was 0.80 with a Bayesian classifier using four features including fractal dimension, entropy, sum entropy, and inverse difference moment. Analysis of the performance of the methods with free-response receiver operating characteristics indicated a sensitivity of 0.79 at 8.4 false positives per image in the detection of sites of architectural distortion in the ''prior mammograms''. Fractal dimension offers a promising way to detect the presence of architectural distortion in prior mammograms. (orig.)

  16. Accommodating Uncertainty in Prior Distributions

    Energy Technology Data Exchange (ETDEWEB)

    Picard, Richard Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vander Wiel, Scott Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-19

    A fundamental premise of Bayesian methodology is that a priori information is accurately summarized by a single, precisely de ned prior distribution. In many cases, especially involving informative priors, this premise is false, and the (mis)application of Bayes methods produces posterior quantities whose apparent precisions are highly misleading. We examine the implications of uncertainty in prior distributions, and present graphical methods for dealing with them.

  17. External-beam boost prior to total-body irradiation in relapsed NHL transplant patients

    Energy Technology Data Exchange (ETDEWEB)

    Monson, Jedidiah M; Neuberg, Donna; Freedman, Arnold S; Tarbell, Nancy J; Nadler, Lee M; Mauch, Peter

    1995-07-01

    PURPOSE: To determine the impact of an external beam boost (EBB) on the outcome, relapse pattern and normal tissue toxicities of patients undergoing total-body irradiation (TBI) prior to bone marrow transplantation (BMT) for relapsed NHL. MATERIALS AND METHODS: Between 1982 and 1994, 299 patients at our institution underwent BMT for relapsed NHL. Patients underwent induction chemotherapy (CT) followed by conditioning with cyclophosphamide and 12 Gy TBI delivered in 6 fractions over 3 days. A total of 77 patients had persistent gross disease, defined as 2 cm or greater, after induction CT and received an EBB prior to BMT (EBB cohort). The median EBB dose was 28.8 Gy (range, 5-63), the median field size was 13 cm{sup 2} (range, 5-29.4) and the median time from EBB to BMT was 3 weeks (range, 1-20). A total of 222 patients were free of measurable disease or had disease measuring <2cm after CT and did not receive EBB (no-EBB cohort). To assess normal tissue toxicity, patients' simulation films and/or treatment records were reviewed for all 77 patients treated with local EBB and estimates were made of the percentage lung, heart and kidney in the radiation field. RESULTS: A total of 79 of 222 patients (36%) in the no-EBB cohort have relapsed; 33 of 77 patients (43%) in the EBB cohort have relapsed (p=0.28, by Fisher exact test). Median time to relapse after BMT was 54 months for the no-EBB cohort and 38 months for the EBB cohort (p=0.26, by log-rank test). The 3-year actuarial freedom from relapse (deaths in remission censored) was 59% for the no-EBB cohort (90% CI: 52-66%) and 51% for the EBB cohort (90% CI: 40-62%). Data on site of relapse was available for 101 of the 112 relapses (75 no-EBB, 26 EBB). For the no-EBB cohort 33 of 75 relapses (44%) were in sites of prior nodal disease only. For the EBB cohort, 12 of 26 relapses (46%) were in sites of prior nodal disease only, of these, only 6 (23%) were within the EBB treatment field. A total of 26 patients had thoracic

  18. Receiver gain function: the actual NMR receiver gain

    OpenAIRE

    Mo, Huaping; Harwood, John S.; Raftery, Daniel

    2010-01-01

    The observed NMR signal size depends on the receiver gain parameter. We propose a receiver gain function to characterize how much the raw FID is amplified by the receiver as a function of the receiver gain setting. Although the receiver is linear for a fixed gain setting, the actual gain of the receiver may differ from what the gain setting suggests. Nevertheless, for a given receiver, we demonstrate that the receiver gain function can be calibrated. Such a calibration enables accurate compar...

  19. Complex treatment of primary brain neuroblastoma with four local recurrences for period of 5 years -clinical case from our practice

    International Nuclear Information System (INIS)

    Marinova, L.; Georgiev, R.; Mihaylova, I.; Belcheva, M.

    2017-01-01

    We present a clinical case of 17 years old girl with primary brain neuroblastoma (supratentorial primitive neuro-ectodermal tumor - PNET in right temporo-parietal brain region). Complex treatment has been applied, including subtotal operation, standard fractioned cranio-spinal external beam radiotherapy with boost up to 56 Gy in the locus of the tumor remnant and 6 courses of adjuvant chemotherapy with Carboplatin and Etoposide. Despite the applied local treatment methods (radical surgery, standard fractioned cranio-spinal external beam radiotherapy and radio-surgery with single total dose of 14 Gy), four recurrences have appeared for period of 5 years in the locus of the primary tumor. The risk of appearance of local recurrences, necessitating re-operations, chemotherapy, bone marrow transplantation of stem cells and radio-surgery was discussed. We are also discussing the radio sensitivity of the PNET and the possibilities for overcoming it with implementation of hyper fractioned cranio-spinal external beam radiotherapy in combination with chemotherapy, followed by bone marrow transplantation of stem cells. Key words: Primary Brain Neuroblastoma. Radio Sensitivity. Cranio-Spinal External Beam Radiotherapy. Adjuvant Chemotherapy [bg

  20. Iterated random walks with shape prior

    DEFF Research Database (Denmark)

    Pujadas, Esmeralda Ruiz; Kjer, Hans Martin; Piella, Gemma

    2016-01-01

    the parametric probability density function. Then, random walks is performed iteratively aligning the prior with the current segmentation in every iteration. We tested the proposed approach with natural and medical images and compared it with the latest techniques with random walks and shape priors......We propose a new framework for image segmentation using random walks where a distance shape prior is combined with a region term. The shape prior is weighted by a confidence map to reduce the influence of the prior in high gradient areas and the region term is computed with k-means to estimate....... The experiments suggest that this method gives promising results for medical and natural images....

  1. Acute coronary syndrome in patients with prior coronary artery bypass surgery: observations from a 20-year registry in a middle-eastern country.

    Directory of Open Access Journals (Sweden)

    Rafid Al-Aqeedi

    Full Text Available OBJECTIVES: Clinical characteristics and trends in the outcome of acute coronary syndrome (ACS in patients with prior coronary artery bypass graft surgery (CABG are unclear. The aim of this study was to evaluate clinical characteristics, in-hospital treatment, and outcomes in patients presented with ACS with or without a history of prior CABG over 2 decades. METHODS: Data were derived from hospital-based study for collected data from 1991 through 2010 of patients hospitalized with ACS in Doha, Qatar. Data were analyzed according to their history of prior CABG. Baseline clinical characteristics, in-hospital treatment, and outcome were compared. RESULTS: A total 16,750 consecutive patients with ACS were studied, of which 693 (4.1% had prior CABG. Patients with prior CABG were older (mean 60.5±11 vs. 53±12 years; P = 0.001, more likely to be females and have more cardiovascular risk factors than the non-CABG group. Prior CABG patients had larger infarct size, were less likely to receive reperfusion therapy, early invasive therapy and more likely to receive evidence-based therapies when compared to non-CABG patients. In-hospital mortality and stroke rates were comparable between the 2 groups. Over 2 decades, there was reduction in the in-hospital mortality rates and stroke rates in both groups (CABG, death; 13.2% to 4%, stroke; 1.9% to 0.0%, non-CABG, death; 10% to 3.2%, stroke 1.0% to 0.1%; all, p = 0.001. CONCLUSION: Significant reduction in-hospital morbidity and mortality among ACS patients with prior CABG over a 20-year period.

  2. The Prior-project

    DEFF Research Database (Denmark)

    Engerer, Volkmar Paul; Roued-Cunliffe, Henriette; Albretsen, Jørgen

    digitisation of Arthur Prior’s Nachlass kept in the Bodleian Library, Oxford. The DH infrastructure in question is the Prior Virtual Lab (PVL). PVL was established in 2011 in order to provide researchers in the field of temporal logic easy access to the papers of Arthur Norman Prior (1914-1969), and officially......In this paper, we present a DH research infrastructure which relies heavily on a combination of domain knowledge with information technology. The general goal is to develop tools to aid scholars in their interpretations and understanding of temporal logic. This in turn is based on an extensive...

  3. Effect of Wind Flow on Convective Heat Losses from Scheffler Solar Concentrator Receivers

    Science.gov (United States)

    Nene, Anita Arvind; Ramachandran, S.; Suyambazhahan, S.

    2018-05-01

    Receiver is an important element of solar concentrator system. In a Scheffler concentrator, solar rays get concentrated at focus of parabolic dish. While radiation losses are more predictable and calculable since strongly related to receiver temperature, convective looses are difficult to estimate in view of additional factors such as wind flow direction, speed, receiver geometry, prior to current work. Experimental investigation was carried out on two geometries of receiver namely cylindrical and conical with 2.7 m2 Scheffler to find optimum condition of tilt to provide best efficiency. Experimental results showed that as compared to cylindrical receiver, conical receiver gave maximum efficiency at 45° tilt angle. However effect of additional factors like wind speed, wind direction on especially convective losses could not be separately seen. The current work was undertaken to investigate further the same two geometries using computation fluid dynamics using FLUENT to compute convective losses considering all variables such at tilt angle of receiver, wind velocity and wind direction. For cylindrical receiver, directional heat transfer coefficient (HTC) is remarkably high to tilt condition meaning this geometry is critical to tilt leading to higher convective heat losses. For conical receiver, directional average HTC is remarkably less to tilt condition leading to lower convective heat loss.

  4. Radiotherapy of the neuroaxis for palliative treatment of leptomeningeal carcinomatosis

    International Nuclear Information System (INIS)

    Hermann, B.; Hueltenschmidt, B.; Sautter-Bihl, M.L.

    2001-01-01

    Background: Leptomeningeal carcinomatosis occurs in about 5% of solid tumors and may seriously compromise quality of life. Aim of the present study was to evaluate the feasibility of craniospinal irradiation with and without intrathecal chemotherapy and its efficacy with regard to symptom palliation and survival. Patients and Methods: 16 patients (mean age 46 years; nine breast cancers, five lung cancers, one renal cell cancer, one tumor of unknown primary site) with leptomeningeal carcinomatosis occurring after a median interval from primary tumor diagnosis of 5 months (0-300 months) received craniospinal irradiation between October 1995 and May 2000. The median total dose was 36 Gy (a 1.6-2.0 Gy). Ten patients were additionally treated with intrathecal methotrexate (15 mg per cycle, 2-8 cycles). Results: Median survival was 12 weeks, 8 weeks after radiotherapy alone, 16 weeks after combined modality treatment. 14 patients died from disease. Eleven patients (68%) experienced regression of their neurological symptoms during or soon after completion of radiotherapy. Seven patients regained their ability to walk, six had pain reduction, three regression of bladder and bowel incontinence. In three patients symptom progression and in two patients no change occurred. Side effects were: Myelosuppression (CTC) Grade I: n=2, Grade II: n=4, Grade III: n=4 patients and Grade IV: n=1. Nine patients had dysphagia, seven mucositis, three suffered from nausea. No late toxicity was observed. Conclusion: Craniospinal radiotherapy is feasible and effective for palliative treatment of leptomeningeal carcinomatosis. As far as the small patient number permits any definite conclusions, combined modality treatment seems superior to irradiation alone. (orig.) [de

  5. Acute toxicity and treatment interruption related to electron and photon craniospinal irradiation in pediatric patients treated at the University of Texas M. D. Anderson Cancer Center

    International Nuclear Information System (INIS)

    Chang, Eric L.; Allen, Pamela; Wu, Catherine; Ater, Joann; Kuttesch, John; Maor, Moshe H.

    2002-01-01

    Purpose: To determine the incidence of acute toxicity and treatment interruption associated with electron and photon craniospinal irradiation (CSI) in children treated with or without chemotherapy. Methods and Materials: A retrospective study involving a computerized search of the radiotherapy database at the University of Texas M. D. Anderson Cancer Center identified a total of 79 eligible patients ≤18 years old who had received electron (n=46) or photon (n=33) CSI from October 1980 to March 2000. Acute toxicity was graded according to the 1998 National Cancer Institute Common Toxicity Criteria. Chemotherapy sequencing was categorized as before or after CSI or no chemotherapy. The incidences of weight loss and skin toxicity were recorded and differences in treatment interruption and hematologic values with respect to modality used (electron vs. photon), age (≤6 or >6 years), and sequencing of chemotherapy were compared using chi-square tests. Results: The median age of the electron group was lower than that of the photon group (6.7 years and 11.7 years, respectively). The two groups were otherwise well matched in terms of median spinal dose (31.1 vs. 33.3 Gy), fraction size (1.57 vs. 1.63 Gy), and total treatment time (32.4 vs. 30.7 days). Only 2 patients in each group (photon and electron) had a treatment break (>3 days). The mean number of days interrupted was 0.94 (photon) and 1.1 (electron) (p=0.72). The electron and photon groups were well balanced in terms of receiving pre-CSI chemotherapy (37% vs. 41%, p=0.776). Chemotherapy given before radiotherapy vs. after or not at all was associated with an increased incidence of Grade 3-4 leukopenia (76% vs. 49%, p=0.02), thrombocytopenia (90% vs. 10%, p=0), and neutropenia (50% vs. 15%, p=0.005). A younger age was associated with Grade 3-4 thrombocytopenia (29% vs. 8.7%, p=0.034), and decreased hemoglobin (29% vs. 6.5%, p=0.014). The incidence of leukocyte depression of Grade 3-4 toxicity was 62% in the electron

  6. Development and implementation of an anthropomorphic pediatric spine phantom for the assessment of craniospinal irradiation procedures in proton therapy

    Directory of Open Access Journals (Sweden)

    Dana J Lewis

    2014-03-01

    analysis criterion for the film planes.--------------------------------------Cite this article as: Lewis DJ, Summers PA, Followill DS, Sahoo N, Mahajan A, Stingo FC, Kry SF. Development and implementation of an anthropomorphic pediatric spine phantom for the assessment of craniospinal irradiation procedures in proton therapy. Int J Cancer Ther Oncol 2014; 2(2:020227. DOI: 10.14319/ijcto.0202.27

  7. The Influence of Prior Knowledge on the Retrieval-Directed Function of Note Taking in Prior Knowledge Activation

    Science.gov (United States)

    Wetzels, Sandra A. J.; Kester, Liesbeth; van Merrienboer, Jeroen J. G.; Broers, Nick J.

    2011-01-01

    Background: Prior knowledge activation facilitates learning. Note taking during prior knowledge activation (i.e., note taking directed at retrieving information from memory) might facilitate the activation process by enabling learners to build an external representation of their prior knowledge. However, taking notes might be less effective in…

  8. Outcome and prognostic factors of desmoplastic medulloblastoma treated within a multidisciplinary treatment concept

    International Nuclear Information System (INIS)

    Rieken, Stefan; Gaiser, Timo; Mohr, Angela; Welzel, Thomas; Witt, Olaf; Kulozik, Andreas E; Wick, Wolfgang; Debus, Jürgen; Combs, Stephanie E

    2010-01-01

    Desmoplasia in medulloblastoma is often diagnosed in adult patients and was repeatedly associated with improved results. Today, all medulloblastoma patients receive intensive multimodal treatment including surgery, radiotherapy and chemotherapy. This study was set up to investigate treatment outcome and prognostic factors after radiation therapy in patients with desmoplastic medulloblastomas. Twenty patients treated for desmoplastic medulloblastoma in the Department of Radiation Oncology at the University of Heidelberg between 1984 and 2007 were included. Data were collected retrospectively. Tumor resection was performed in all patients. All patients underwent postsurgical radiotherapy (RT). Two patients underwent whole brain radiotherapy (WBRT), and 18 patients received craniospinal irradiation (CSI). In all patients, an additional boost was delivered to the posterior fossa. The median dose to the whole brain and the craniospinal axis was 35.2 Gray (Gy), and 54.4 Gy to the posterior fossa. Fourteen patients received chemotherapy, including seven who were treated with combined radiochemotherapy and twelve who received adjuvant chemotherapy. Statistical analysis was performed using the log-rank test and the Kaplan-Meier method. Median follow-up was 59 months. Overall (OS), local (LPFS) and distant progression-free survival (DPFS) was 80%, 71.2%, and 83.3% at 60 months. Patients who suffered from local or distant relapses had significantly worse outcome. Five patients died from recurrent medulloblastoma. Treatment-associated toxicity was acceptable. Multimodal approaches with surgical resection followed by chemoirradiation achieved high response rates with long OS in desmoplastic medulloblastoma patients. Staging parameters expected to predict for poor prognosis did not significantly influence outcome. However, success of any first line regimen had strong impact on disease control, and remission was achieved in no patient with relapsing disease. Multimodal concepts

  9. A final report on the Phase 1 testing of a molten-salt cavity receiver

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, J M [ed.; Smith, D C [Babcock and Wilcox Co., Barberton, OH (United States). Nuclear Equipment Div.

    1992-05-01

    This report describes the design, construction, and testing of a solar central receiver using molten nitrate salt as a heat exchange fluid. Design studies for large commercial plants (30--100 MWe) have shown molten salt to be an excellent fluid for solar thermal plants as it allows for efficient thermal storage. Plant design studies concluded that an advanced receiver test was required to address uncertainties not covered in prior receiver tests. This recommendation led to the current test program managed by Sandia National Laboratories for the US Department of Energy. The 4.5 MWt receiver is installed at Sandia National Laboratories' Central Receiver Test Facility in Albuquerque, New Mexico. The receiver incorporates features of large commercial receiver designs. This report describes the receiver's configuration, heat absorption surface (design and sizing), the structure and supporting systems, and the methods for control. The receiver was solar tested during a six-month period at the Central Receiver Test Facility in Albuquerque, NM. The purpose of the testing was to characterize the operational capabilities of the receiver under a number of solar operating and stand-by conditions. This testing consisted of initial check-out of the systems, followed by steady-state performance, transient receiver operation, receiver operation in clouds, receiver thermal loss testing, receiver start-up operation, and overnight thermal conditioning tests. This report describes the design, fabrication, and results of testing of the receiver.

  10. Varying prior information in Bayesian inversion

    International Nuclear Information System (INIS)

    Walker, Matthew; Curtis, Andrew

    2014-01-01

    Bayes' rule is used to combine likelihood and prior probability distributions. The former represents knowledge derived from new data, the latter represents pre-existing knowledge; the Bayesian combination is the so-called posterior distribution, representing the resultant new state of knowledge. While varying the likelihood due to differing data observations is common, there are also situations where the prior distribution must be changed or replaced repeatedly. For example, in mixture density neural network (MDN) inversion, using current methods the neural network employed for inversion needs to be retrained every time prior information changes. We develop a method of prior replacement to vary the prior without re-training the network. Thus the efficiency of MDN inversions can be increased, typically by orders of magnitude when applied to geophysical problems. We demonstrate this for the inversion of seismic attributes in a synthetic subsurface geological reservoir model. We also present results which suggest that prior replacement can be used to control the statistical properties (such as variance) of the final estimate of the posterior in more general (e.g., Monte Carlo based) inverse problem solutions. (paper)

  11. Growth and growth hormone secretion in children following treatment of brain tumours with radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Darendeliler, F.; Livesey, E.A.; Hindmarsh, P.C.; Brook, C.G.D. (Endocrine Unit, The Middlesex Hospital, London (UK))

    1990-01-01

    We have studied the growth of 144 children after treatment of brain tumours distant from the hypothalamo-pituitary axis. All had cranial irradiation and 87 spinal irradiation. In 56 patients observed without intervention for 3 years, height SDS in the cranial (CR) group (n=20) declined from 0.02 to -0.44 and in the craniospinal (CS) group (n=36) from -0.28 to -1.11. Failure of spinal growth had a marked effect in the CS group. The onset of puberty was slightly but not significantly advanced; median ages at onset of puberty were 10.3 years in girls and 12.1 years in boys. Of the total group 86.4% had clinical and biochemical evidence of growth hormone insufficiency. Fifty-two children, 33 (28 CS; 5 CR) of whome were prepubertal, received biosynthetic human growth hormone, in a dose of 15 mU/m{sup 2}/week by daily injection for a period of one year. Height velocity SDS increased significantly in both groups from -2.74 to +1.90 (CS) and from -1.0 to +4.26 (CR). Spinal response to GH treatment was restricted in the craniospinal group. (authors).

  12. Growth and growth hormone secretion in children following treatment of brain tumours with radiotherapy

    International Nuclear Information System (INIS)

    Darendeliler, F.; Livesey, E.A.; Hindmarsh, P.C.; Brook, C.G.D.

    1990-01-01

    We have studied the growth of 144 children after treatment of brain tumours distant from the hypothalamo-pituitary axis. All had cranial irradiation and 87 spinal irradiation. In 56 patients observed without intervention for 3 years, height SDS in the cranial (CR) group (n=20) declined from 0.02 to -0.44 and in the craniospinal (CS) group (n=36) from -0.28 to -1.11. Failure of spinal growth had a marked effect in the CS group. The onset of puberty was slightly but not significantly advanced; median ages at onset of puberty were 10.3 years in girls and 12.1 years in boys. Of the total group 86.4% had clinical and biochemical evidence of growth hormone insufficiency. Fifty-two children, 33 (28 CS; 5 CR) of whome were prepubertal, received biosynthetic human growth hormone, in a dose of 15 mU/m 2 /week by daily injection for a period of one year. Height velocity SDS increased significantly in both groups from -2.74 to +1.90 (CS) and from -1.0 to +4.26 (CR). Spinal response to GH treatment was restricted in the craniospinal group. (authors)

  13. The Prior Internet Resources 2017

    DEFF Research Database (Denmark)

    Engerer, Volkmar Paul; Albretsen, Jørgen

    2017-01-01

    The Prior Internet Resources (PIR) are presented. Prior’s unpublished scientific manuscripts and his wast letter correspondence with fellow researchers at the time, his Nachlass, is now subject to transcription by Prior-researchers worldwide, and form an integral part of PIR. It is demonstrated...

  14. Patient Self-Report of Prior Laser Treatment Reliably Indicates Presence of Severe Diabetic Retinopathy

    Science.gov (United States)

    GRASSI, MICHAEL A.; MAZZULLA, D. ANTHONY; KNUDTSON, MICHAEL D.; HUANG, WENDY W.; LEE, KRISTINE E.; KLEIN, BARBARA E.; NICOLAE, DAN L.; KLEIN, RONALD

    2009-01-01

    PURPOSE To determine whether patient self-report of prior laser treatment can be used as a reliable tool for assessing the presence of severe diabetic retinopathy. DESIGN This was a retrospective study on two groups of diabetic subjects. METHODS One hundred patients with diabetes were recruited from the general eye and retina clinics at the University of Chicago Hospitals. The patients were asked, “Have you ever received laser treatment for your diabetic eye disease (DED)?” A chart review was then conducted noting if the patient had received either focal laser treatment for diabetic macular edema or panretinal photocoagulation for proliferative diabetic retinopathy. Data from the Wisconsin Epidemiological Study of Diabetic Retinopathy (WESDR) were also analyzed. Participant responses to the question “Have you had laser photocoagulation treatment for your eyes?” were analyzed with documentation of photocoagulation scars determined by grading seven-standard field color fundus photographs. RESULTS In the University of Chicago group, 96 of 100 (96%) of patients were accurate in reporting whether they had received previous laser treatment for DED (sensitivity 95.8%, specificity 96.1%, and positive predictive value 88.5%). In the WESDR analysis, 2,329 of 2,348 (99%) of participants were accurate in reporting whether they had prior laser treatment for DED (sensitivity 96.0%, specificity 99.5%, and positive predictive value 95.6%). CONCLUSIONS The high sensitivity and specificity of our results validate the use of patient self-report as a useful tool in assessing past laser treatment for severe diabetic retinopathy. Patient self-report may be a useful surrogate to clinical examination or medical record review to determine the presence of severe diabetic retinopathy. PMID:19054495

  15. Gorlin-Goltz syndrome and neoplasms: a case study.

    Science.gov (United States)

    Lopes, Nilza N F; Caran, Eliana M; Lee, Maria Lucia; Silva, Nasjla Saba; Rocha, André Caroli; Macedo, Carla R D

    2010-01-01

    Gorlin syndrome is a rare autosomal dominant disorder exhibiting high penetrance and variable expressivity. It is characterized by facial dysmorphism, skeletal anomalies, multiple basal cell carcinomas, odontogenic keratocysts (OKC), palmar and plantar pits, bifid ribs, vertebral anomalies and a variety of other malformations. Various neoplasms, such as medulloblastomas, meningiomas, ovarian and cardiac fibromas are also found in this syndrome. To describe a twelve-year-old patient with Gorlin-Goltz syndrome, with basal cell carcinomas and promyelocytic leukemia developed after receiving craniospinal radiation for a medulloblastoma. Bifid ribs as well as mandibular and maxillar OKC were also diagnosed Conclusion: The patient with Gorlin-Goltz syndrome should receive close follow-up for early detection of malformations nd malignant neoplasias.

  16. Incidence of meningeal involvement by rhabdomyosarcoma of the head and neck in children. A report of the Intergroup Rhabdomyosarcoma Study (IRS)

    International Nuclear Information System (INIS)

    Tefft, M.; Fernandez, C.; Donaldson, M.; Newton, W.; Moon, T.E.

    1978-01-01

    One hundred and forty-one patients with embryonal rhabdomyosarcoma (RMS) of the head and neck are reviewed. 57/141 had lesions of para-meningeal sites. 20/57 (35%) developed evidence of direct meningeal extension. 18/20 (90%) died of this complication. Radiation portals and doses were limited in 42% and 32%, respectively. All patients had chemotherapy for 6 weeks prior to radiation. The significance of the adequacy of radiation factors and the timing of chemotherapy are reviewed. Recommendations for managing these patients include earlier use of radiation and increased coverage of adjacent meninges by radiation including total craniospinal axis radiation when brain meningeal involvement exists

  17. Radiation in the treatment of meningeal leukemia

    International Nuclear Information System (INIS)

    Jenkin, R.D.

    1979-01-01

    At the present time, a successful regimen for the eradication of occult meningeal leukemia is the combination of cranial radiotherapy in a dose of 1800 rads in 10 fractions in 12 to 14 days with six doses of intrathecal methotrexate. This regimen, when given with prednisone and vincristine can be expected to give a relapse rate for isolated meningeal leukemia of approximately 5% during the first 2 years of follow-up. A modification of this regimen utilizing craniospinal radiation with prior and concurrent intrathecal methotrexate is given for the treatment of overt meningeal leukemia at diagnosis or for an isolated first relapse with meningeal leukemia. Radiation technique and morbidity are discussed

  18. Penalised Complexity Priors for Stationary Autoregressive Processes

    KAUST Repository

    Sø rbye, Sigrunn Holbek; Rue, Haavard

    2017-01-01

    The autoregressive (AR) process of order p(AR(p)) is a central model in time series analysis. A Bayesian approach requires the user to define a prior distribution for the coefficients of the AR(p) model. Although it is easy to write down some prior, it is not at all obvious how to understand and interpret the prior distribution, to ensure that it behaves according to the users' prior knowledge. In this article, we approach this problem using the recently developed ideas of penalised complexity (PC) priors. These prior have important properties like robustness and invariance to reparameterisations, as well as a clear interpretation. A PC prior is computed based on specific principles, where model component complexity is penalised in terms of deviation from simple base model formulations. In the AR(1) case, we discuss two natural base model choices, corresponding to either independence in time or no change in time. The latter case is illustrated in a survival model with possible time-dependent frailty. For higher-order processes, we propose a sequential approach, where the base model for AR(p) is the corresponding AR(p-1) model expressed using the partial autocorrelations. The properties of the new prior distribution are compared with the reference prior in a simulation study.

  19. Penalised Complexity Priors for Stationary Autoregressive Processes

    KAUST Repository

    Sørbye, Sigrunn Holbek

    2017-05-25

    The autoregressive (AR) process of order p(AR(p)) is a central model in time series analysis. A Bayesian approach requires the user to define a prior distribution for the coefficients of the AR(p) model. Although it is easy to write down some prior, it is not at all obvious how to understand and interpret the prior distribution, to ensure that it behaves according to the users\\' prior knowledge. In this article, we approach this problem using the recently developed ideas of penalised complexity (PC) priors. These prior have important properties like robustness and invariance to reparameterisations, as well as a clear interpretation. A PC prior is computed based on specific principles, where model component complexity is penalised in terms of deviation from simple base model formulations. In the AR(1) case, we discuss two natural base model choices, corresponding to either independence in time or no change in time. The latter case is illustrated in a survival model with possible time-dependent frailty. For higher-order processes, we propose a sequential approach, where the base model for AR(p) is the corresponding AR(p-1) model expressed using the partial autocorrelations. The properties of the new prior distribution are compared with the reference prior in a simulation study.

  20. Difference between received and expected knowledge of patients undergoing knee or hip replacement in seven European countries.

    Science.gov (United States)

    Klemetti, Seija; Leino-Kilpi, Helena; Cabrera, Esther; Copanitsanou, Panagiota; Ingadottir, Brynja; Istomina, Natalja; Katajisto, Jouko; Papastavrou, Evridiki; Unosson, Mitra; Valkeapää, Kirsi

    2015-12-01

    The purpose of the study was to examine received and expected knowledge of patients with knee/hip arthroplasty in seven European countries. The goal was to obtain information for developing empowering patient education. The data were collected (during 2009-2012) from patients (n = 943) with hip/knee arthroplasty prior to scheduled preoperative education and before discharge with the Received Knowledge of hospital patient scale (RKhp) and Expected Knowledge of hospital patient scale (EKhp). Patients' knowledge expectations were high but the level of received knowledge did not correspond to expectations. The difference between received and expected knowledge was higher in Greece and Sweden compared with Finland (p European countries. © The Author(s) 2014.

  1. Books Received

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Books Received. Articles in Resonance – Journal of Science Education. Volume 1 Issue 1 January 1996 pp 118-118 Books Received. Books Received · More Details Fulltext PDF. Volume 1 Issue 2 February 1996 pp 120-120 Books Received. Books Received.

  2. The effect of pre-course e-learning prior to advanced life support training: a randomised controlled trial.

    Science.gov (United States)

    Perkins, Gavin D; Fullerton, James N; Davis-Gomez, Nicole; Davies, Robin P; Baldock, Catherine; Stevens, Harry; Bullock, Ian; Lockey, Andrew S

    2010-07-01

    The role of e-learning in contemporary healthcare education is quickly developing. The aim of this study was to examine the relationship between the use of an e-learning simulation programme (Microsim, Laerdal, UK) prior to attending an Advanced Life Support (ALS) course and the subsequent relationship to candidate performance. An open label, multi-centre randomised controlled study was conducted. The control group received a course manual and pre-course MCQ four weeks prior to the face to face course. The intervention group in addition received the Microsim programme on a CD. The primary outcome was performance during a simulated cardiac arrest at the end of the course. Secondary outcomes were performance during multiple choice exams, resuscitation skills assessments and feedback to Microsim programme. 572 participants were randomised (287 Microsim, 285 control). There were no significant differences in the primary outcome (performance during a standard cardiac arrest simulation) or secondary outcomes. User evaluations were favorable. 79% would recommend it to colleagues. 9% stated Microsim could replace the entire ALS course, 25% parts. Over 70% of participants' perceived that Microsim improved their understanding of the key learning domains of the ALS course. Distributing Microsim to healthcare providers prior to attending an ALS courses did not improve either cognitive or psychomotor skills performance during cardiac arrest simulation testing. The challenge that lies ahead is to identify the optimal way to use e-learning as part of a blended approach to learning for this type of training programme.

  3. Generalized Bayesian inference with sets of conjugate priors for dealing with prior-data conflict : course at Lund University

    NARCIS (Netherlands)

    Walter, G.

    2015-01-01

    In the Bayesian approach to statistical inference, possibly subjective knowledge on model parameters can be expressed by so-called prior distributions. A prior distribution is updated, via Bayes’ Rule, to the so-called posterior distribution, which combines prior information and information from

  4. The Importance of Prior Knowledge.

    Science.gov (United States)

    Cleary, Linda Miller

    1989-01-01

    Recounts a college English teacher's experience of reading and rereading Noam Chomsky, building up a greater store of prior knowledge. Argues that Frank Smith provides a theory for the importance of prior knowledge and Chomsky's work provided a personal example with which to interpret and integrate that theory. (RS)

  5. Comparison of proton therapy techniques for treatment of the whole brain as a component of craniospinal radiation.

    Science.gov (United States)

    Dinh, Jeffrey; Stoker, Joshua; Georges, Rola H; Sahoo, Narayan; Zhu, X Ronald; Rath, Smruti; Mahajan, Anita; Grosshans, David R

    2013-12-17

    For treatment of the entire cranium using passive scattering proton therapy (PSPT) compensators are often employed in order to reduce lens and cochlear exposure. We sought to assess the advantages and consequences of utilizing compensators for the treatment of the whole brain as a component of craniospinal radiation (CSI) with PSPT. Moreover, we evaluated the potential benefits of spot scanning beam delivery in comparison to PSPT. Planning computed tomography scans for 50 consecutive CSI patients were utilized to generate passive scattering proton therapy treatment plans with and without Lucite compensators (PSW and PSWO respectively). A subset of 10 patients was randomly chosen to generate scanning beam treatment plans for comparison. All plans were generated using an Eclipse treatment planning system and were prescribed to a dose of 36 Gy(RBE), delivered in 20 fractions, to the whole brain PTV. Plans were normalized to ensure equal whole brain target coverage. Dosimetric data was compiled and statistical analyses performed using a two-tailed Student's t-test with Bonferroni corrections to account for multiple comparisons. Whole brain target coverage was comparable between all methods. However, cribriform plate coverage was superior in PSWO plans in comparison to PSW (V95%; 92.9 ± 14 vs. 97.4 ± 5, p left; 24.8 ± 0.8 vs. 22.2 ± 0.7, p right; 25.2 ± 0.8 vs. 22.8 ± 0.7, p vs. PSWO (mean cochlea dose Gy(RBE): 36.4 ± 0.2 vs. 36.7 ± 0.1, p = NS). Moreover, dose homogeneity was inferior in PSW plans in comparison to PSWO plans as reflected by significant alterations in both whole brain and brainstem homogeneity index (HI) and inhomogeneity coefficient (IC). In comparison to both PSPT techniques, multi-field optimized intensity modulated (MFO-IMPT) spot scanning treatment plans displayed superior sparing of both lens and cochlea (max lens: 12.5 ± 0.6 and 12.9 ± 0.7 right and left respectively; mean cochlea 28.6

  6. Comparison of proton therapy techniques for treatment of the whole brain as a component of craniospinal radiation

    International Nuclear Information System (INIS)

    Dinh, Jeffrey; Stoker, Joshua; Georges, Rola H; Sahoo, Narayan; Zhu, X Ronald; Rath, Smruti; Mahajan, Anita; Grosshans, David R

    2013-01-01

    For treatment of the entire cranium using passive scattering proton therapy (PSPT) compensators are often employed in order to reduce lens and cochlear exposure. We sought to assess the advantages and consequences of utilizing compensators for the treatment of the whole brain as a component of craniospinal radiation (CSI) with PSPT. Moreover, we evaluated the potential benefits of spot scanning beam delivery in comparison to PSPT. Planning computed tomography scans for 50 consecutive CSI patients were utilized to generate passive scattering proton therapy treatment plans with and without Lucite compensators (PSW and PSWO respectively). A subset of 10 patients was randomly chosen to generate scanning beam treatment plans for comparison. All plans were generated using an Eclipse treatment planning system and were prescribed to a dose of 36 Gy(RBE), delivered in 20 fractions, to the whole brain PTV. Plans were normalized to ensure equal whole brain target coverage. Dosimetric data was compiled and statistical analyses performed using a two-tailed Student’s t-test with Bonferroni corrections to account for multiple comparisons. Whole brain target coverage was comparable between all methods. However, cribriform plate coverage was superior in PSWO plans in comparison to PSW (V95%; 92.9 ± 14 vs. 97.4 ± 5, p < 0.05). As predicted, PSWO plans had significantly higher lens exposure in comparison to PSW plans (max lens dose Gy(RBE): left; 24.8 ± 0.8 vs. 22.2 ± 0.7, p < 0.05, right; 25.2 ± 0.8 vs. 22.8 ± 0.7, p < 0.05). However, PSW plans demonstrated no significant cochlear sparing vs. PSWO (mean cochlea dose Gy(RBE): 36.4 ± 0.2 vs. 36.7 ± 0.1, p = NS). Moreover, dose homogeneity was inferior in PSW plans in comparison to PSWO plans as reflected by significant alterations in both whole brain and brainstem homogeneity index (HI) and inhomogeneity coefficient (IC). In comparison to both PSPT techniques, multi-field optimized intensity modulated (MFO-IMPT) spot

  7. Prior oral conditions in patients undergoing heart valve surgery.

    Science.gov (United States)

    Silvestre, Francisco-Javier; Gil-Raga, Irene; Martinez-Herrera, Mayte; Lauritano, Dorina; Silvestre-Rangil, Javier

    2017-11-01

    Patients scheduled for heart valve surgery should be free of any oral infectious disorders that might pose a risk in the postoperative period. Few studies have been made on the dental conditions of such patients prior to surgery. The present study describes the most frequent prior oral diseases in this population group. A prospective, observational case-control study was designed involving 60 patients (30 with heart valve disease and 30 controls, with a mean age of 71 years in both groups). A dental exploration was carried out, with calculation of the DMFT (decayed, missing and filled teeth) index and recording of the periodontal parameters (plaque index, gingival bleeding index, periodontal pocket depth, and attachment loss). The oral mucosa was also examined, and panoramic X-rays were used to identify possible intrabony lesions. Significant differences in bacterial plaque index were observed between the two groups ( p <0.05), with higher scores in the patients with valve disease. Probing depth and the presence of moderate pockets were also greater in the patients with valve disease than among the controls ( p <0.01). Sixty percent of the patients with valve disease presented periodontitis. Patients scheduled for heart valve surgery should be examined for possible active periodontitis before the operation. Those individuals found to have periodontal disease should receive adequate periodontal treatment before heart surgery. Key words: Valve disease, aortic, mitral, heart surgery, periodontitis.

  8. In-hospital management and outcomes of acute coronary syndromes in relation to prior history of heart failure.

    Science.gov (United States)

    Zhang, Hanfei; Goodman, Shaun G; Yan, Raymond T; Steg, Ph Gabriel; Kornder, Jan M; Gyenes, Gabor T; Grondin, Francois R; Brieger, David; DeYoung, J Paul; Gallo, Richard; Yan, Andrew T

    2016-06-01

    The prognostic significance of prior heart failure in acute coronary syndromes has not been well studied. Accordingly, we evaluated the baseline characteristics, management patterns and clinical outcomes in patients with acute coronary syndromes who had prior heart failure. The study population consisted of acute coronary syndrome patients in the Global Registry of Acute Coronary Events, expanded Global Registry of Acute Coronary Events and Canadian Registry of Acute Coronary Events between 1999 and 2008. Of the 13,937 eligible patients (mean age 66±13 years, 33% female and 28.3% with ST-elevation myocardial infarction), 1498 (10.7%) patients had a history of heart failure. Those with prior heart failure tended to be older, female and had lower systolic blood pressure, higher Killip class and creatinine on presentation. Prior heart failure was also associated with significantly worse left ventricular systolic function and lower rates of cardiac catheterization and coronary revascularization. The group with previous heart failure had significantly higher rates of acute decompensated heart failure, cardiogenic shock, myocardial (re)infarction and mortality in hospital. In multivariable analysis, prior heart failure remained an independent predictor of in-hospital mortality (odds ratio 1.48, 95% confidence interval 1.08-2.03, p=0.015). Prior heart failure was associated with high risk features on presentation and adverse outcomes including higher adjusted in-hospital mortality in acute coronary syndrome patients. However, acute coronary syndrome patients with prior heart failure were less likely to receive evidence-based therapies, suggesting potential opportunities to target more intensive treatment to improve their outcome. © The European Society of Cardiology 2015.

  9. Savings for visuomotor adaptation require prior history of error, not prior repetition of successful actions.

    Science.gov (United States)

    Leow, Li-Ann; de Rugy, Aymar; Marinovic, Welber; Riek, Stephan; Carroll, Timothy J

    2016-10-01

    When we move, perturbations to our body or the environment can elicit discrepancies between predicted and actual outcomes. We readily adapt movements to compensate for such discrepancies, and the retention of this learning is evident as savings, or faster readaptation to a previously encountered perturbation. The mechanistic processes contributing to savings, or even the necessary conditions for savings, are not fully understood. One theory suggests that savings requires increased sensitivity to previously experienced errors: when perturbations evoke a sequence of correlated errors, we increase our sensitivity to the errors experienced, which subsequently improves error correction (Herzfeld et al. 2014). An alternative theory suggests that a memory of actions is necessary for savings: when an action becomes associated with successful target acquisition through repetition, that action is more rapidly retrieved at subsequent learning (Huang et al. 2011). In the present study, to better understand the necessary conditions for savings, we tested how savings is affected by prior experience of similar errors and prior repetition of the action required to eliminate errors using a factorial design. Prior experience of errors induced by a visuomotor rotation in the savings block was either prevented at initial learning by gradually removing an oppositely signed perturbation or enforced by abruptly removing the perturbation. Prior repetition of the action required to eliminate errors in the savings block was either deprived or enforced by manipulating target location in preceding trials. The data suggest that prior experience of errors is both necessary and sufficient for savings, whereas prior repetition of a successful action is neither necessary nor sufficient for savings. Copyright © 2016 the American Physiological Society.

  10. Overcoming the Challenges of BeiDou Receiver Implementation

    Directory of Open Access Journals (Sweden)

    Mohammad Zahidul H. Bhuiyan

    2014-11-01

    Full Text Available Global Navigation Satellite System (GNSS-based positioning is experiencing rapid changes. The existing GPS and the GLONASS systems are being modernized to better serve the current challenging applications under harsh signal conditions. These modernizations include increasing the number of transmission frequencies and changes to the signal components. In addition, the Chinese BeiDou Navigation Satellite system (BDS and the European Galileo are currently under development for global operation. Therefore, in view of these new upcoming systems the research and development of GNSS receivers has been experiencing a new upsurge. In this article, the authors discuss the main functionalities of a GNSS receiver in view of BDS. While describing the main functionalities of a software-defined BeiDou receiver, the authors also highlight the similarities and differences between the signal characteristics of the BeiDou B1 open service signal and the legacy GPS L1 C/A signal, as in general they both exhibit similar characteristics. In addition, the authors implement a novel acquisition technique for long coherent integration in the presence of NH code modulation in BeiDou D1 signal. Furthermore, a simple phase-preserved coherent integration based acquisition scheme is implemented for BeiDou GEO satellite acquisition. Apart from the above BeiDou-specific implementations, a novel Carrier-to-Noise-density ratio estimation technique is also implemented in the software receiver, which does not necessarily require bit synchronization prior to estimation. Finally, the authors present a BeiDou-only position fix with the implemented software-defined BeiDou receiver considering all three satellite constellations from BDS. In addition, a true multi-GNSS position fix with GPS and BDS systems is also presented while comparing their performances for a static stand-alone code phase-based positioning.

  11. Divergent Priors and well Behaved Bayes Factors

    NARCIS (Netherlands)

    R.W. Strachan (Rodney); H.K. van Dijk (Herman)

    2011-01-01

    textabstractDivergent priors are improper when defined on unbounded supports. Bartlett's paradox has been taken to imply that using improper priors results in ill-defined Bayes factors, preventing model comparison by posterior probabilities. However many improper priors have attractive properties

  12. Motivational interviewing: a part of the weight loss program for overweight and obese women prior to fertility treatment.

    Science.gov (United States)

    Karlsen, Kamilla; Humaidan, Peter; Sørensen, Lise H; Alsbjerg, Birgit; Ravn, Pernille

    2013-09-01

    This is a retrospective study to investigate whether motivational interviewing increases weight loss among obese or overweight women prior to fertility treatment. Women with body mass index (BMI) > 30 kg/m(2) approaching the Fertility Clinic, Regional Hospital Skive, were given advice about diet and physical activity with the purpose of weight loss. In addition, they were asked if they wanted to receive motivational interviewing. Among other data, age, height and weight were obtained. Main outcomes were weight loss measured in kg and decrease in BMI. We studied 187 women: 110 received sessions of motivational interviewing (intervention group, n = 110), 64 received motivational support by phone or e-mail only and 13 women did not wish any motivational support (control group, n = 77). The mean weight loss and decrease in BMI was greater in the intervention group compared with the control group (9.3 kg versus 7.3 kg, difference p = 0.01, 3.3 kg/m(2) versus 2.6 kg/m(2), difference p = 0.02). The mean period of intervention was comparable in the two groups, 7.9 month and 7.3 month, respectively, (difference non significant: NS). The study indicates that motivational interviewing may be a valuable tool in weight loss programs for obese and overweight women prior to fertility treatment.

  13. Evaluating Prior Scholarship in Literature Reviews of Research Articles: A Comparative Study of Practices in Two Research Paradigms

    Science.gov (United States)

    Kwan, Becky S. C.; Chan, Hang; Lam, Colin

    2012-01-01

    Evaluations of prior scholarship play a crucial role in the literature review (LR) of a research article by showing how the boundary of an area of inquiry can be further advanced by the writer's work. Yet, many inexperienced writers find evaluating others' work a major challenge. Although the task has received some attention in research and…

  14. The role of adjuvant platinum-based chemotherapy in esophagogastric cancer patients who received neoadjuvant chemotherapy prior to definitive surgery.

    Science.gov (United States)

    Saunders, John H; Bowman, Christopher R; Reece-Smith, Alex M; Pang, Vincent; Dorrington, Matthew S; Mumtaz, Errum; Soomro, Irshad; Kaye, Philip; Madhusudan, Srinivasan; Parsons, Simon L

    2017-06-01

    For patients with operable esophagogastric cancer, peri-operative chemotherapy confers a significant overall survival benefit compared to surgery alone, however only 30-40% of patients demonstrate histopathological response. It is unclear whether those with no neoadjuvant chemotherapy response should go onto receive adjuvant chemotherapy, as no further benefit may be conferred. Esophagogastric cancers were prospectively captured with associated histopathological tumor regression grades following neoadjuvant chemotherapy. This cohort was then interrogated for clinico-pathological and survival outcomes. Following neoadjuvant chemotherapy and surgery, patients with chemotherapy responsive cancers, who were administered adjuvant chemotherapy gained a significant overall survival benefit. Multivariate Cox analysis, demonstrated a final adjusted hazard ratio for adjuvant therapy of 0.509; (95%CI 0.28-0.93); P = 0.028. In contrast, patients with non-responsive tumors, who underwent adjuvant chemotherapy, did not show any survival benefit. Chemotherapy toxicity was prevalent and contributed to only half of patients receiving adjuvant chemotherapy. These results suggest the benefit of the adjuvant portion of chemotherapy is limited to those who demonstrate a histopathological response to neoadjuvant chemotherapy. The administration of the adjuvant portion of chemotherapy to patients without a response to neoadjuvant chemotherapy may not provide any survival benefit, while potentially causing increased morbidity. © 2017 Wiley Periodicals, Inc.

  15. Impact of prior therapies on everolimus activity: an exploratory analysis of RADIANT-4

    Directory of Open Access Journals (Sweden)

    Buzzoni R

    2017-10-01

    Full Text Available Roberto Buzzoni,1 Carlo Carnaghi,2 Jonathan Strosberg,3 Nicola Fazio,4 Simron Singh,5 Fabian Herbst,6 Antonia Ridolfi,7 Marianne E Pavel,8 Edward M Wolin,9 Juan W Valle,10 Do-Youn Oh,11 James C Yao,12 Rodney Pommier13 1IRCCS Foundation, National Institute of Tumors, Milan, Italy; 2Humanitas Clinical and Research Center, Rozzano, Italy; 3Moffitt Cancer Center, Tampa, FL, USA; 4European Institute of Oncology, Milan, Italy; 5Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 6Novartis AG, Basel, Switzerland; 7Novartis Pharma S.A.S., Rueil-Malmaison, France; 8Medizinische Klinik 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany; 9Montefiore Einstein Center for Cancer Care, Bronx, NY, USA; 10Institute of Cancer Sciences, University of Manchester, The Christie Hospital, Manchester, UK; 11Seoul National University Hospital, Seoul, Republic of Korea; 12University of Texas M.D. Anderson Cancer Center, Houston, TX, USA; 13Oregon Health & Science University, Portland, OR, USA Background: Recently, everolimus was shown to improve median progression-free survival (PFS by 7.1 months in patients with advanced, progressive, well-differentiated, nonfunctional neuroendocrine tumors (NET of lung or gastrointestinal (GI tract compared with placebo (HR, 0.48; 95% CI, 0.35–0.67; P<0.00001 in the Phase III, RADIANT-4 study. This post hoc analysis evaluates the impact of prior therapies (somatostatin analogs [SSA], chemotherapy, and radiotherapy on everolimus activity. Trial registration: ClinicalTrials.gov identifier: NCT01524783. Patients and methods: Patients were randomized (2:1 to everolimus 10 mg/day or placebo, both with best supportive care. Subgroups of patients who received prior SSA, chemotherapy, or radiotherapy (including peptide receptor radionuclide therapy were analyzed and reported. Results: A total of 302 patients were enrolled, of whom, 163 (54% had any prior SSA use (mostly for tumor control, 77 (25% received

  16. Prior knowledge in recalling arguments in bioethical dilemmas

    Directory of Open Access Journals (Sweden)

    Hiemke Katharina Schmidt

    2015-09-01

    Full Text Available Prior knowledge is known to facilitate learning new information. Normally in studies confirming this outcome the relationship between prior knowledge and the topic to be learned is obvious: the information to be acquired is part of the domain or topic to which the prior knowledge belongs. This raises the question as to whether prior knowledge of various domains facilitates recalling information. In this study 79 eleventh-grade students completed a questionnaire on their prior knowledge of seven different domains related to the bioethical dilemma of prenatal diagnostics. The students read a text containing arguments for and arguments against prenatal diagnostics. After one week and again 12 weeks later they were asked to write down all the arguments they remembered. Prior knowledge helped them recall the arguments one week (r = .350 and 12 weeks (r = .316 later. Prior knowledge of three of the seven domains significantly helped them recall the arguments one week later (correlations between r = .194 to r = .394. Partial correlations with interest as a control item revealed that interest did not explain the relationship between prior knowledge and recall. Prior knowledge of different domains jointly supports the recall of arguments related to bioethical topics.

  17. Spiritual well-being among outpatients with cancer receiving concurrent oncologic and palliative care.

    Science.gov (United States)

    Rabow, Michael W; Knish, Sarah J

    2015-04-01

    Spiritual well-being is threatened by cancer, but its correlation with other illness symptoms and the efficacy of palliative care (PC) to ameliorate spiritual suffering are not well understood. We conducted a retrospective study using a convenience sample of oncology patients at a comprehensive cancer center who received concurrent oncologic and palliative care between 2008 and 2011 and completed ESAS, QUAL-E, and Steinhauser Spiritual well-being survey questions was conducted. Descriptive, correlation, and t test statistics. Eight hundred eighty-three patients surveyed had an average age of 65.6 years, with 54.1 % female, 69.3 % white, and 49.3 % married. Half (452, 51.2 %) had metastatic disease. Religious affiliation was reported as Christian by 20.3 %, Catholic by 18.7 %, and "none" by 39.0 %. Baseline spiritual well-being was not significantly correlated with age, gender, race, cancer stage, marital status, insurance provider, or having a religious affiliation. Greater spiritual well-being was correlated with greater quality of life (well-being (spiritual well-being and anxiety, depression, fatigue, and quality of life (R (2) = 0.677). Spiritual well-being improved comparing mean scores immediately prior to initial PC consultation with those at first follow-up (2.89 vs. 3.23 on a 1-5 scale, p = 0.005). Among patients with cancer receiving concurrent oncologic and palliative care, spiritual well-being was not associated with patient age, gender, or race, or disease stage. It was correlated with physical and emotional symptoms. Spiritual well-being scores improved from just prior to the initial PC consultation to just prior to the first PC follow-up visit.

  18. Testability evaluation using prior information of multiple sources

    Institute of Scientific and Technical Information of China (English)

    Wang Chao; Qiu Jing; Liu Guanjun; Zhang Yong

    2014-01-01

    Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR) and fault isolation rate (FIR), which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testabil-ity demonstration test data (TDTD) such as low evaluation confidence and inaccurate result, a test-ability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF), and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

  19. Effects of prophylactic treatment of central nervous system leukemia in children

    International Nuclear Information System (INIS)

    Abe, Yukiko; Asakura, Akio; Endo, Norio

    1982-01-01

    Thirty-five children with previously untreated ALL or AUL who received CNS prophylatic therapy with 3 treatment regiments were analyzed. After eutering complete remission, patients received CNS-prophylaxis with one of the following regimens: Goup A- cyclic high dose multichemotherapy plus intermittent intra-thecal methotrexate (MTX); Group B-craniospinal irradiation plus intermittent intrathecal MTX; Group C-intermittent high dose intravenous MTX. Incidence of CNS-leukemia and bone marrow relapse was less frequent in Group B. EEG abnormalities were seen in 38.5% of Group A, 40% of Group B, and 28.6% of Group C respectively, but the abnormalities were transient. IQs of three groups were above 100, but IQs of CNS-leukemia patients, especially VIQs had a tendency to be low. (author)

  20. Waste Receiving and Processing Module 2A waste certification strategy

    International Nuclear Information System (INIS)

    LeClair, M.D.; Pottmeyer, J.A.; Hyre, R.A.

    1994-01-01

    This document addresses the certification of Mixed Low Level Waste (MLLW) that will be treated in the Waste Receiving and Processing Facility Module 2A (WRAP 2A) and is destined for disposal in the MLLW trench of the Low Level Burial Grounds (LLBG). The MLLW that will be treated in WRAP 2A contains land disposal restricted and radioactive constituents. Certification of the treated waste is dependent on numerous waste management activities conducted throughout the WRAP 2A operation. These activities range from waste treatability testing conducted prior to WRAP 2A waste acceptance to overchecking final waste form quality prior to transferring waste to disposal. This document addresses the high level strategies and methodologies for certifying the final waste form. Integration among all design and verification activities that support final waste form quality assurance is also discussed. The information generated from this effort may directly support other ongoing activities including the WRAP 2A Waste Characterization Study, WRAP 2A Waste Analysis Plan development, Sample Plan development, and the WRAP 2A Data Management System functional requirements definition

  1. Can natural selection encode Bayesian priors?

    Science.gov (United States)

    Ramírez, Juan Camilo; Marshall, James A R

    2017-08-07

    The evolutionary success of many organisms depends on their ability to make decisions based on estimates of the state of their environment (e.g., predation risk) from uncertain information. These decision problems have optimal solutions and individuals in nature are expected to evolve the behavioural mechanisms to make decisions as if using the optimal solutions. Bayesian inference is the optimal method to produce estimates from uncertain data, thus natural selection is expected to favour individuals with the behavioural mechanisms to make decisions as if they were computing Bayesian estimates in typically-experienced environments, although this does not necessarily imply that favoured decision-makers do perform Bayesian computations exactly. Each individual should evolve to behave as if updating a prior estimate of the unknown environment variable to a posterior estimate as it collects evidence. The prior estimate represents the decision-maker's default belief regarding the environment variable, i.e., the individual's default 'worldview' of the environment. This default belief has been hypothesised to be shaped by natural selection and represent the environment experienced by the individual's ancestors. We present an evolutionary model to explore how accurately Bayesian prior estimates can be encoded genetically and shaped by natural selection when decision-makers learn from uncertain information. The model simulates the evolution of a population of individuals that are required to estimate the probability of an event. Every individual has a prior estimate of this probability and collects noisy cues from the environment in order to update its prior belief to a Bayesian posterior estimate with the evidence gained. The prior is inherited and passed on to offspring. Fitness increases with the accuracy of the posterior estimates produced. Simulations show that prior estimates become accurate over evolutionary time. In addition to these 'Bayesian' individuals, we also

  2. Example-driven manifold priors for image deconvolution.

    Science.gov (United States)

    Ni, Jie; Turaga, Pavan; Patel, Vishal M; Chellappa, Rama

    2011-11-01

    Image restoration methods that exploit prior information about images to be estimated have been extensively studied, typically using the Bayesian framework. In this paper, we consider the role of prior knowledge of the object class in the form of a patch manifold to address the deconvolution problem. Specifically, we incorporate unlabeled image data of the object class, say natural images, in the form of a patch-manifold prior for the object class. The manifold prior is implicitly estimated from the given unlabeled data. We show how the patch-manifold prior effectively exploits the available sample class data for regularizing the deblurring problem. Furthermore, we derive a generalized cross-validation (GCV) function to automatically determine the regularization parameter at each iteration without explicitly knowing the noise variance. Extensive experiments show that this method performs better than many competitive image deconvolution methods.

  3. A prospective neurocognitive evaluation of children treated with additional chemotherapy and craniospinal irradiation following isolated central nervous system relapse in acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Kumar, Parvesh; Mulhern, Raymond K.; Regine, William F.; Rivera, Gaston K.; Kun, Larry E.

    1995-01-01

    Purpose: A prospective assessment of neurocognitive performance was conducted in children with acute lymphoblastic leukemia (ALL) following isolated central nervous system (CNS) relapse to evaluate the impact of additional systemic/intrathecal (IT) chemotherapy and craniospinal irradiation (CSI) upon long-term intellectual function. Methods and Materials: Twenty-one children with ALL manifesting an isolated CNS relapse between 1984 through 1989 underwent serial evaluations of intellectual function. Neurocognitive function was measured by the full-scale intelligence quotient (FSIQ) as determined by the age-appropriate Wechsler Intelligence Scale and by achievement in reading, math, and spelling as assessed by the Wide Range Achievement Test (WRAT). Intelligence testing was initiated following isolated CNS relapse after clearance of cerebrospinal fluid (CSF) cytology but prior to CSI and continued at annual intervals for a minimum of 4 years postmeningeal failure. Protocol treatment for isolated CNS relapse consisted of reinduction and maintenance systemic therapy, intrathecal (IT) triple-agent chemotherapy, and early CSI (cranium to 24 Gy and spine to 15 Gy at 1.5 Gy/fraction) as outlined on the institutional 'Total XI' trial. Results: All 21 children attained secondary CNS remission and underwent the planned additional systemic/IT chemotherapy and CSI. Fourteen of the 21 children remain in secondary continuous remission, while the remaining 7 experienced a second relapse and were removed from further neurocognitive assessment. For the eight female and six male long-term survivors, mean ages at original diagnosis and at CSI were 5.7 years (range = 0.6-16.2) and 7.0 years (range = 1.8-17.0), respectively. At a median follow-up interval of 4.6 years (ranges 1.7-6.8) post-CNS relapse, comparison of group mean initial to final FSIQs revealed no statistically significant difference between the two measures (94.5 vs. 95.9, respectively, n = 11, p = 0.52). None of the

  4. Testability evaluation using prior information of multiple sources

    Directory of Open Access Journals (Sweden)

    Wang Chao

    2014-08-01

    Full Text Available Testability plays an important role in improving the readiness and decreasing the life-cycle cost of equipment. Testability demonstration and evaluation is of significance in measuring such testability indexes as fault detection rate (FDR and fault isolation rate (FIR, which is useful to the producer in mastering the testability level and improving the testability design, and helpful to the consumer in making purchase decisions. Aiming at the problems with a small sample of testability demonstration test data (TDTD such as low evaluation confidence and inaccurate result, a testability evaluation method is proposed based on the prior information of multiple sources and Bayes theory. Firstly, the types of prior information are analyzed. The maximum entropy method is applied to the prior information with the mean and interval estimate forms on the testability index to obtain the parameters of prior probability density function (PDF, and the empirical Bayesian method is used to get the parameters for the prior information with a success-fail form. Then, a parametrical data consistency check method is used to check the compatibility between all the sources of prior information and TDTD. For the prior information to pass the check, the prior credibility is calculated. A mixed prior distribution is formed based on the prior PDFs and the corresponding credibility. The Bayesian posterior distribution model is acquired with the mixed prior distribution and TDTD, based on which the point and interval estimates are calculated. Finally, examples of a flying control system are used to verify the proposed method. The results show that the proposed method is feasible and effective.

  5. Attentional and Contextual Priors in Sound Perception.

    Science.gov (United States)

    Wolmetz, Michael; Elhilali, Mounya

    2016-01-01

    Behavioral and neural studies of selective attention have consistently demonstrated that explicit attentional cues to particular perceptual features profoundly alter perception and performance. The statistics of the sensory environment can also provide cues about what perceptual features to expect, but the extent to which these more implicit contextual cues impact perception and performance, as well as their relationship to explicit attentional cues, is not well understood. In this study, the explicit cues, or attentional prior probabilities, and the implicit cues, or contextual prior probabilities, associated with different acoustic frequencies in a detection task were simultaneously manipulated. Both attentional and contextual priors had similarly large but independent impacts on sound detectability, with evidence that listeners tracked and used contextual priors for a variety of sound classes (pure tones, harmonic complexes, and vowels). Further analyses showed that listeners updated their contextual priors rapidly and optimally, given the changing acoustic frequency statistics inherent in the paradigm. A Bayesian Observer model accounted for both attentional and contextual adaptations found with listeners. These results bolster the interpretation of perception as Bayesian inference, and suggest that some effects attributed to selective attention may be a special case of contextual prior integration along a feature axis.

  6. Total Variability Modeling using Source-specific Priors

    DEFF Research Database (Denmark)

    Shepstone, Sven Ewan; Lee, Kong Aik; Li, Haizhou

    2016-01-01

    sequence of an utterance. In both cases the prior for the latent variable is assumed to be non-informative, since for homogeneous datasets there is no gain in generality in using an informative prior. This work shows in the heterogeneous case, that using informative priors for com- puting the posterior......, can lead to favorable results. We focus on modeling the priors using minimum divergence criterion or fac- tor analysis techniques. Tests on the NIST 2008 and 2010 Speaker Recognition Evaluation (SRE) dataset show that our proposed method beats four baselines: For i-vector extraction using an already...... trained matrix, for the short2-short3 task in SRE’08, five out of eight female and four out of eight male common conditions, were improved. For the core-extended task in SRE’10, four out of nine female and six out of nine male common conditions were improved. When incorporating prior information...

  7. Quantitative Evidence Synthesis with Power Priors

    NARCIS (Netherlands)

    Rietbergen, C.|info:eu-repo/dai/nl/322847796

    2016-01-01

    The aim of this thesis is to provide the applied researcher with a practical approach for quantitative evidence synthesis using the conditional power prior that allows for subjective input and thereby provides an alternative tgbgo deal with the difficulties as- sociated with the joint power prior

  8. Multimodality therapy for medulloblastoma

    International Nuclear Information System (INIS)

    Thomas, P.R.M.; Duffner, P.K.; Cohen, M.E.; Sinks, L.F.; Tebbi, C.; Freeman, A.I.

    1980-01-01

    Eight patients with recurrent medulloblastoma were treated with a chemotherapy regimen consisting of vincristine, BCNU, dexamethasone and intrathecal and intermediate dose intravenous methotrexate (500 mg/m 2 ). Five also received local low dose radiotherapy (RT). All 8 patients responded to treatment; 6 completely and 2 partially. These latter 2 were in their second and third recurrences. Three remain in remission. The median duration of response was 18.8 months, and median time from start of chemotherapy to death was 32 months using the Kaplan-Meier technique. In addition, 9 other patients with newly diagnosed medulloblastoma were treated with craniospinal radiation and the same adjuvant chemotherapy as above. The first 5 patients also received intraventricular methotrexate and/or intravenous BCNU during radiotherapy. The toxicity in the 5 patients was very severe. There were three toxic deaths, one death from cancer; one patient survives disease-free, but he is demented. With the discontinuance of intraventricular methotrexate and the postponement of myelosuppressive chemotherapy until after the completion of radiotherapy, the regimen has been well tolerated. All 4 patients treated this way remain alive, well, and disease-free at intervals up to 36 months. We conclude that recurrent medulloblastomas are sensitive to multiagent chemotherapy and that prolonged remissions may occur. With primary adjuvant chemotherapy, extreme caution with myelosuppressive drugs must be exercised during the period of craniospinal radiotherapy. We also do not recommend the use of intraventricular methotrexate. When these two criteria were followed, the preliminary results with adjuvant chemotherapy appear encouraging

  9. Patterns of pharmacotherapy and health care utilization and costs prior to total hip or total knee replacement in patients with osteoarthritis.

    Science.gov (United States)

    Berger, Ariel; Bozic, Kevin; Stacey, Brett; Edelsberg, John; Sadosky, Alesia; Oster, Gerry

    2011-08-01

    To examine patterns of pharmacotherapy and health care utilization and costs prior to total knee replacement (TKR) or total hip replacement (THR) in patients with osteoarthritis (OA). Using a large US health insurance claims database, we identified all patients with OA who were ages ≥40 years and had undergone TKR or THR between January 1, 2006 and December 31, 2007. Patients with care utilization and costs over the 2-year period preceding surgery. A total of 16,527 patients met all study entry criteria. Their mean ± SD age was 56.6 ± 6.1 years, and 56% of them were women. In the 2 years preceding surgery, 55% of patients received prescription nonsteroidal antiinflammatory drugs, 58% received opioids, and 50% received injections of corticosteroids. The numbers of patients receiving these drugs increased steadily during the presurgery period. The mean ± SD total health care costs in the 2 years preceding surgery were $19,466 ± 29,869, of which outpatient care, inpatient care, and pharmacotherapy represented 45%, 20%, and 20%, respectively. Costs increased from $2,094 in the eighth calendar quarter prior to surgery to $3,100 in the final quarter. Patients with OA who undergo THR or TKR have relatively high levels of use of pain-related pharmacotherapy and high total health care costs in the 2-year period preceding surgery. Levels of utilization and cost increase as the date of surgery approaches. Copyright © 2011 by the American College of Rheumatology.

  10. Recruiting for Prior Service Market

    Science.gov (United States)

    2008-06-01

    perceptions, expectations and issues for re-enlistment • Develop potential marketing and advertising tactics and strategies targeted to the defined...01 JUN 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Recruiting for Prior Service Market 5a. CONTRACT NUMBER 5b. GRANT...Command First Handshake to First Unit of Assignment An Army of One Proud to Be e e to Serve Recruiting for Prior Service Market MAJ Eric Givens / MAJ Brian

  11. PET image reconstruction using multi-parametric anato-functional priors

    Science.gov (United States)

    Mehranian, Abolfazl; Belzunce, Martin A.; Niccolini, Flavia; Politis, Marios; Prieto, Claudia; Turkheimer, Federico; Hammers, Alexander; Reader, Andrew J.

    2017-08-01

    In this study, we investigate the application of multi-parametric anato-functional (MR-PET) priors for the maximum a posteriori (MAP) reconstruction of brain PET data in order to address the limitations of the conventional anatomical priors in the presence of PET-MR mismatches. In addition to partial volume correction benefits, the suitability of these priors for reconstruction of low-count PET data is also introduced and demonstrated, comparing to standard maximum-likelihood (ML) reconstruction of high-count data. The conventional local Tikhonov and total variation (TV) priors and current state-of-the-art anatomical priors including the Kaipio, non-local Tikhonov prior with Bowsher and Gaussian similarity kernels are investigated and presented in a unified framework. The Gaussian kernels are calculated using both voxel- and patch-based feature vectors. To cope with PET and MR mismatches, the Bowsher and Gaussian priors are extended to multi-parametric priors. In addition, we propose a modified joint Burg entropy prior that by definition exploits all parametric information in the MAP reconstruction of PET data. The performance of the priors was extensively evaluated using 3D simulations and two clinical brain datasets of [18F]florbetaben and [18F]FDG radiotracers. For simulations, several anato-functional mismatches were intentionally introduced between the PET and MR images, and furthermore, for the FDG clinical dataset, two PET-unique active tumours were embedded in the PET data. Our simulation results showed that the joint Burg entropy prior far outperformed the conventional anatomical priors in terms of preserving PET unique lesions, while still reconstructing functional boundaries with corresponding MR boundaries. In addition, the multi-parametric extension of the Gaussian and Bowsher priors led to enhanced preservation of edge and PET unique features and also an improved bias-variance performance. In agreement with the simulation results, the clinical results

  12. Prior elicitation and Bayesian analysis of the Steroids for Corneal Ulcers Trial.

    Science.gov (United States)

    See, Craig W; Srinivasan, Muthiah; Saravanan, Somu; Oldenburg, Catherine E; Esterberg, Elizabeth J; Ray, Kathryn J; Glaser, Tanya S; Tu, Elmer Y; Zegans, Michael E; McLeod, Stephen D; Acharya, Nisha R; Lietman, Thomas M

    2012-12-01

    To elicit expert opinion on the use of adjunctive corticosteroid therapy in bacterial corneal ulcers. To perform a Bayesian analysis of the Steroids for Corneal Ulcers Trial (SCUT), using expert opinion as a prior probability. The SCUT was a placebo-controlled trial assessing visual outcomes in patients receiving topical corticosteroids or placebo as adjunctive therapy for bacterial keratitis. Questionnaires were conducted at scientific meetings in India and North America to gauge expert consensus on the perceived benefit of corticosteroids as adjunct treatment. Bayesian analysis, using the questionnaire data as a prior probability and the primary outcome of SCUT as a likelihood, was performed. For comparison, an additional Bayesian analysis was performed using the results of the SCUT pilot study as a prior distribution. Indian respondents believed there to be a 1.21 Snellen line improvement, and North American respondents believed there to be a 1.24 line improvement with corticosteroid therapy. The SCUT primary outcome found a non-significant 0.09 Snellen line benefit with corticosteroid treatment. The results of the Bayesian analysis estimated a slightly greater benefit than did the SCUT primary analysis (0.19 lines verses 0.09 lines). Indian and North American experts had similar expectations on the effectiveness of corticosteroids in bacterial corneal ulcers; that corticosteroids would markedly improve visual outcomes. Bayesian analysis produced results very similar to those produced by the SCUT primary analysis. The similarity in result is likely due to the large sample size of SCUT and helps validate the results of SCUT.

  13. The influence of prior knowledge on the retrieval-directed function of note taking in prior knowledge activation

    NARCIS (Netherlands)

    Wetzels, Sandra; Kester, Liesbeth; Van Merriënboer, Jeroen; Broers, Nick

    2010-01-01

    Wetzels, S. A. J., Kester, L., Van Merriënboer, J. J. G., & Broers, N. J. (2011). The influence of prior knowledge on the retrieval-directed function of note taking in prior knowledge activation. British Journal of Educational Psychology, 81(2), 274-291. doi: 10.1348/000709910X517425

  14. Craniospinal irradiation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scarlatescu, Ioana, E-mail: scarlatescuioana@gmail.com; Avram, Calin N. [Faculty of Physics, West University of Timisoara, Bd. V. Parvan 4, 300223 Timisoara (Romania); Virag, Vasile [County Hospital “Gavril Curteanu” - Oradea (Romania)

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  15. Prior Sensitivity Analysis in Default Bayesian Structural Equation Modeling.

    Science.gov (United States)

    van Erp, Sara; Mulder, Joris; Oberski, Daniel L

    2017-11-27

    Bayesian structural equation modeling (BSEM) has recently gained popularity because it enables researchers to fit complex models and solve some of the issues often encountered in classical maximum likelihood estimation, such as nonconvergence and inadmissible solutions. An important component of any Bayesian analysis is the prior distribution of the unknown model parameters. Often, researchers rely on default priors, which are constructed in an automatic fashion without requiring substantive prior information. However, the prior can have a serious influence on the estimation of the model parameters, which affects the mean squared error, bias, coverage rates, and quantiles of the estimates. In this article, we investigate the performance of three different default priors: noninformative improper priors, vague proper priors, and empirical Bayes priors-with the latter being novel in the BSEM literature. Based on a simulation study, we find that these three default BSEM methods may perform very differently, especially with small samples. A careful prior sensitivity analysis is therefore needed when performing a default BSEM analysis. For this purpose, we provide a practical step-by-step guide for practitioners to conducting a prior sensitivity analysis in default BSEM. Our recommendations are illustrated using a well-known case study from the structural equation modeling literature, and all code for conducting the prior sensitivity analysis is available in the online supplemental materials. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Atezolizumab in Platinum-treated Locally Advanced or Metastatic Urothelial Carcinoma: Outcomes by Prior Number of Regimens.

    Science.gov (United States)

    Perez-Gracia, Jose Luis; Loriot, Yohann; Rosenberg, Jonathan E; Powles, Thomas; Necchi, Andrea; Hussain, Syed A; Morales-Barrera, Rafael; Retz, Margitta M; Niegisch, Günter; Durán, Ignacio; Théodore, Christine; Grande, Enrique; Shen, Xiaodong; Wang, Jingjing; Nelson, Betty; Derleth, Christina L; van der Heijden, Michiel S

    2017-12-19

    Patients with metastatic urothelial carcinoma (mUC) who progress after platinum-based chemotherapy have had few treatment options and uniformly poor outcomes. Atezolizumab (anti-programmed death-ligand 1) was approved in the USA for cisplatin-ineligible and platinum-treated mUC based on IMvigor210, a phase 2, single-arm, two-cohort study. To evaluate the efficacy and safety of atezolizumab by the number of prior lines of systemic therapy in patients with pretreated mUC. IMvigor210 enrolled 315 patients with mUC with progression during or following platinum-based therapy at 70 international sites between May 2014 and November 2014. Key inclusion criteria included age ≥18 yr, creatinine clearance ≥30ml/min, and Eastern Cooperative Oncology Group performance status 0-1, with no limit on prior lines of treatment. Patients in this cohort received atezolizumab 1200mg intravenously every 3 wk until loss of clinical benefit. Centrally assessed Response Evaluation Criteria In Solid Tumors v1.1 objective response rate (ORR), median duration of response, overall survival (OS), and adverse events were evaluated by prior treatment. Potential differences between subgroups were evaluated using log-rank (for OS) and chi-square (for ORR and adverse events frequencies) testing. Three hundred and ten patients were efficacy and safety evaluable (median follow-up, 21 mo). Objective responses and prolonged OS occurred across all prespecified subgroups; median duration of response was not reached in most subgroups. In patients without prior systemic mUC therapy (first-line subgroup), ORR was 25% (95% confidence interval: 14-38), and median OS was 9.6 mo (95% confidence interval: 5.9-15.8). No significant differences in efficacy or toxicity by therapy line were observed. Atezolizumab demonstrated comparable efficacy and safety in previously treated patients with mUC across all lines of therapy evaluated. We investigated effects of previous treatment in patients with metastatic

  17. Phase II Study of Bevacizumab in Patients With HIV-Associated Kaposi's Sarcoma Receiving Antiretroviral Therapy

    Science.gov (United States)

    Uldrick, Thomas S.; Wyvill, Kathleen M.; Kumar, Pallavi; O'Mahony, Deirdre; Bernstein, Wendy; Aleman, Karen; Polizzotto, Mark N.; Steinberg, Seth M.; Pittaluga, Stefania; Marshall, Vickie; Whitby, Denise; Little, Richard F.; Yarchoan, Robert

    2012-01-01

    Purpose Alternatives to cytotoxic agents are desirable for patients with HIV-associated Kaposi's sarcoma (KS). Vascular endothelial growth factor-A (VEGF-A) contributes to KS pathogenesis. We evaluated the humanized anti–VEGF-A monoclonal antibody, bevacizumab, in patients with HIV-KS. Patients and Methods Patients with HIV-KS who either experienced progression while receiving highly active antiretroviral therapy (HAART) for at least 1 month or did not regress despite HAART for at least 4 months were administered bevacizumab 15 mg/kg intravenously on days 1 and 8 and then every 3 weeks. The primary objective was assessment of antitumor activity using modified AIDS Clinical Trial Group (ACTG) criteria for HIV-KS. HIV-uninfected patients were also eligible and observed separately. Results Seventeen HIV-infected patients were enrolled. Fourteen patients had been receiving effective HAART for at least 6 months (median, 1 year). Thirteen patients had advanced disease (ACTG T1), 13 patients had received prior chemotherapy for KS, and seven patients had CD4 count less than 200 cells/μL. Median number of cycles was 10 (range, 1 to 37 cycles); median follow-up was 8.3 months (range, 3 to 36 months). Of 16 assessable patients, best tumor responses observed were complete response (CR) in three patients (19%), partial response (PR) in two patients (12%), stable disease in nine patients (56%), and progressive disease in two patients (12%). Overall response rate (CR + PR) was 31% (95% CI, 11% to 58.7%). Four of five responders had received prior chemotherapy for KS. Over 202 cycles, grade 3 to 4 adverse events at least possibly attributed to therapy included hypertension (n = 7), neutropenia (n = 5), cellulitis (n = 3), and headache (n = 2). Conclusion Bevacizumab is tolerated in patients with HIV-KS and has activity in a subset of patients. PMID:22430271

  18. Attenuation of muscle damage by preconditioning with muscle hyperthermia 1-day prior to eccentric exercise.

    Science.gov (United States)

    Nosaka, K; Muthalib, M; Lavender, A; Laursen, P B

    2007-01-01

    This study investigated the hypothesis that muscle damage would be attenuated in muscles subjected to passive hyperthermia 1 day prior to exercise. Fifteen male students performed 24 maximal eccentric actions of the elbow flexors with one arm; the opposite arm performed the same exercise 2-4 weeks later. The elbow flexors of one arm received a microwave diathermy treatment that increased muscle temperature to over 40 degrees C, 16-20 h prior to the exercise. The contralateral arm acted as an untreated control. Maximal voluntary isometric contraction strength (MVC), range of motion (ROM), upper arm circumference, muscle soreness, plasma creatine kinase activity and myoglobin concentration were measured 1 day prior to exercise, immediately before and after exercise, and daily for 4 days following exercise. Changes in the criterion measures were compared between conditions (treatment vs. control) using a two-way repeated measures ANOVA with a significance level of P < 0.05. All measures changed significantly following exercise, but the treatment arm showed a significantly faster recovery of MVC, a smaller change in ROM, and less muscle soreness compared with the control arm. However, the protective effect conferred by the diathermy treatment was significantly less effective compared with that seen in the second bout performed 4-6 weeks after the initial bout by a subgroup of the subjects (n = 11) using the control arm. These results suggest that passive hyperthermia treatment 1 day prior to eccentric exercise-induced muscle damage has a prophylactic effect, but the effect is not as strong as the repeated bout effect.

  19. Offending prior to first psychiatric contact

    DEFF Research Database (Denmark)

    Stevens, H; Agerbo, E; Dean, K

    2012-01-01

    There is a well-established association between psychotic disorders and subsequent offending but the extent to which those who develop psychosis might have a prior history of offending is less clear. Little is known about whether the association between illness and offending exists in non-psychot......-psychotic disorders. The aim of this study was to determine whether the association between mental disorder and offending is present prior to illness onset in psychotic and non-psychotic disorders.......There is a well-established association between psychotic disorders and subsequent offending but the extent to which those who develop psychosis might have a prior history of offending is less clear. Little is known about whether the association between illness and offending exists in non...

  20. Terminology for pregnancy loss prior to viability

    DEFF Research Database (Denmark)

    Kolte, A M; Bernardi, L A; Christiansen, O B

    2015-01-01

    Pregnancy loss prior to viability is common and research in the field is extensive. Unfortunately, terminology in the literature is inconsistent. The lack of consensus regarding nomenclature and classification of pregnancy loss prior to viability makes it difficult to compare study results from...... different centres. In our opinion, terminology and definitions should be based on clinical findings, and when possible, transvaginal ultrasound. With this Early Pregnancy Consensus Statement, it is our goal to provide clear and consistent terminology for pregnancy loss prior to viability....

  1. Bootstrap-based procedures for inference in nonparametric receiver-operating characteristic curve regression analysis.

    Science.gov (United States)

    Rodríguez-Álvarez, María Xosé; Roca-Pardiñas, Javier; Cadarso-Suárez, Carmen; Tahoces, Pablo G

    2018-03-01

    Prior to using a diagnostic test in a routine clinical setting, the rigorous evaluation of its diagnostic accuracy is essential. The receiver-operating characteristic curve is the measure of accuracy most widely used for continuous diagnostic tests. However, the possible impact of extra information about the patient (or even the environment) on diagnostic accuracy also needs to be assessed. In this paper, we focus on an estimator for the covariate-specific receiver-operating characteristic curve based on direct regression modelling and nonparametric smoothing techniques. This approach defines the class of generalised additive models for the receiver-operating characteristic curve. The main aim of the paper is to offer new inferential procedures for testing the effect of covariates on the conditional receiver-operating characteristic curve within the above-mentioned class. Specifically, two different bootstrap-based tests are suggested to check (a) the possible effect of continuous covariates on the receiver-operating characteristic curve and (b) the presence of factor-by-curve interaction terms. The validity of the proposed bootstrap-based procedures is supported by simulations. To facilitate the application of these new procedures in practice, an R-package, known as npROCRegression, is provided and briefly described. Finally, data derived from a computer-aided diagnostic system for the automatic detection of tumour masses in breast cancer is analysed.

  2. Remote tracking of a magnetic receiver using low frequency beacons

    International Nuclear Information System (INIS)

    Sheinker, Arie; Ginzburg, Boris; Salomonski, Nizan; Frumkis, Lev; Kaplan, Ben-Zion

    2014-01-01

    Low frequency magnetic fields feature high penetration ability, which allows communication, localization, and tracking in environments where radio or acoustic waves are blocked or distorted by multipath interferences. In the present work, we propose a method for tracking a magnetic receiver using beacons of low frequency magnetic field, where the receiver includes a tri-axial search-coil magnetometer. Measuring the beacons’ magnetic fields and calculating the total-field signals enables localization without restrictions on magnetometer orientation, allowing on-the-move tracking. The total-field signals are used by a global search method, e.g., simulated annealing (SA) algorithm, to localize the receiver. The magnetic field produced by each beacon has a dipole structure and is governed by the beacon’s position and magnetic moment. We have investigated two different methods for estimating beacons’ magnetic moments prior to localization. The first method requires directional measurements, whereas for the second method the total-field signal is used. Effectiveness of these methods has been proved in numerous field tests. In the present work, we introduce a method for tracking a moving receiver by successive localizations. Using previous localization as a starting point of the search method for the next localization can reduce execution time and chances for divergence. The proposed method has been tested using numerous computer simulations. Successful system operation has been verified in field conditions. The good tracking capability together with simple implementation makes the proposed method attractive for real-time, low power field applications, such as mobile robots navigation. (paper)

  3. Radiation therapy for pineal tumors: 30-year experience at Thomas Jefferson University Hospital

    International Nuclear Information System (INIS)

    Dickerson, G.A.; Tupchong, L.; Moylan, D.J.; Kramer, S.

    1987-01-01

    Eighteen tumors of the pineal region were treated at Thomas Jefferson University Hospital since 1957. Preoperative evaluation included CT scan in 11 patients and cerebrospinal fluid cytology in four. Histologic diagnosis was obtained in nine patients. Diagnosis in two other patients was based on CT scan response at 2,000 cGY. Fifteen patients received whole-brain irradiation with a boost, one each with limited-field and whole-brain irradiation only. One patient with melanoma received craniospinal irradiation. Median pineal dose was 55 Gy; range, 50-60 Gy. Five treatment failures occurred, four local and one distant. Actuarial survival was 80%, 70%, and 65% at 5, 10, and 20 years. Median follow-up was 8.8 years. Cranial radiotherapy alone appears to control the majority of pineal tumors

  4. Postpartum wound and bleeding complications in women who received peripartum anticoagulation.

    Science.gov (United States)

    Limmer, Jane S; Grotegut, Chad A; Thames, Elizabeth; Dotters-Katz, Sarah K; Brancazio, Leo R; James, Andra H

    2013-07-01

    The objective of this study was to compare wound and bleeding complications between women who received anticoagulation after cesarean delivery due to history of prior venous thromboembolic disease, arterial disease, or being a thrombophilia carrier with adverse pregnancy outcome, to women not receiving anticoagulation. Women in the Duke Thrombosis Center Registry who underwent cesarean delivery during 2003-2011 and received postpartum anticoagulation (anticoagulation group, n=77), were compared with a subset of women who delivered during the same time period, but did not receive anticoagulation (no anticoagulation group, n=77). The no anticoagulation group comprised women who were matched to the anticoagulation group by age, body mass index, type of cesarean (no labor vs. labor), and date of delivery. Bleeding and wound complications were compared between the two groups. A multivariable logistic regression model was constructed to determine if anticoagulation was an independent predictor of wound complication. Women who received anticoagulation during pregnancy had a greater incidence of wound complications compared to those who did not (30% vs. 8%, p<0.001). Using multivariable logistic regression, while controlling for race, diabetes, chorioamnionitis, and aspirin use, anticoagulation predicted the development of any wound complication (OR 5.8, 95% CI 2.2, 17.6), but there were no differences in the mean estimated blood loss at delivery (782 vs. 778 ml, p=0.91), change in postpartum hematocrit (5.4 vs. 5.2%, p=0.772), or percent of women receiving blood products (6.5 vs. 1.3%, p=0.209) between the two groups. Anticoagulation following cesarean delivery is associated with an increased risk of post-cesarean wound complications, but not other postpartum bleeding complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. HEMATOPOIETIC PROGENITOR CELLS AS A PREDICTIVE OF CD34+ ENUMERATION PRIOR TO PERIPHERAL BLOOD STEM CELLS HARVESTING

    Directory of Open Access Journals (Sweden)

    Z. Zulkafli

    2014-09-01

    Full Text Available Background: To date, the CD34+ cell enumeration has relied predominantly on flow cytometry technique. However, flow cytometry is time consuming and operator dependent. The application of the hematopoietic progenitor cells (HPCs channel in Sysmex XE-2100, a fully automated hematology analyzer offers an alternative approach, which is with minimal sample manipulation and less operator dependent. This study evaluates the utility of HPC counts as a predictive of CD34+ enumeration prior to peripheral blood stem cells harvesting. Materials and methods: HPC, CD34+, white blood cell (WBC, reticulocytes (retic, immature platelet fraction (IPF and immature reticulocyte fraction (IRF were determined in 61 samples from 19 patients with hematological malignancies (15 lymphoma and 4 multiple myeloma patients at Hospital Universiti Sains Malaysia (Hospital USM who had received granulocyte-colony stimulating factor (G-CSF and planned for autologous transplantation. Results: CD34+ count showed strong and significant correlation with HPC. The receiver operating characteristics (ROC curve analysis revealed that HPC count > 21.5 x 106 / L can predicts a pre harvest CD34+ count of >20 x 106 / L with sensitivity of 77%, specificity of 64% and area under the curve (AUC of 0.802. Conclusion: We concluded that HPC count can be a useful potential parameter in optimizing timing for CD34+ enumeration prior to leukapheresis.

  6. A comparative study on the risks of radiogenic second cancers and cardiac mortality in a set of pediatric medulloblastoma patients treated with photon or proton craniospinal irradiation

    International Nuclear Information System (INIS)

    Zhang, Rui; Howell, Rebecca M.; Taddei, Phillip J.; Giebeler, Annelise; Mahajan, Anita; Newhauser, Wayne D.

    2014-01-01

    Purpose: To compare the risks of radiogenic second cancers and cardiac mortality in 17 pediatric medulloblastoma patients treated with passively scattered proton or field-in-field photon craniospinal irradiation (CSI). Material/methods: Standard of care photon or proton CSI treatment plans were created for all 17 patients in a commercial treatment planning system (TPS) (Eclipse version 8.9; Varian Medical Systems, Palo Alto, CA) and prescription dose was 23.4 or 23.4 Gy (RBE) to the age specific target volume at 1.8 Gy/fraction. The therapeutic doses from proton and photon CSI plans were estimated from TPS. Stray radiation doses were determined from Monte Carlo simulations for proton CSI and from measurements and TPS for photon CSI. The Biological Effects of Ionization Radiation VII report and a linear model based on childhood cancer survivor data were used for risk predictions of second cancer and cardiac mortality, respectively. Results: The ratios of lifetime attributable risk (RLARs) (proton/photon) ranged from 0.10 to 0.22 for second cancer incidence and ranged from 0.20 to 0.53 for second cancer mortality, respectively. The ratio of relative risk (RRR) (proton/photon) of cardiac mortality ranged from 0.12 to 0.24. The RLARs of both cancer incidence and mortality decreased with patient’s age at exposure (e), while the RRRs of cardiac mortality increased with e. Girls had a significantly higher RLAR of cancer mortality than boys. Conclusion: Passively scattered proton CSI provides superior predicted outcomes by conferring lower predicted risks of second cancer and cardiac mortality than field-in-field photon CSI for all medulloblastoma patients in a large clinically representative sample in the United States, but the magnitude of superiority depends strongly on the patients’ anatomical development status

  7. Evaluating a Collaborative Approach to Improve Prior Authorization Efficiency in the Treatment of Hepatitis C Virus.

    Science.gov (United States)

    Dunn, Emily E; Vranek, Kathryn; Hynicka, Lauren M; Gripshover, Janet; Potosky, Darryn; Mattingly, T Joseph

    A team-based approach to obtaining prior authorization approval was implemented utilizing a specialty pharmacy, a clinic-based pharmacy technician specialist, and a registered nurse to work with providers to obtain approval for medications for hepatitis C virus (HCV) infection. The objective of this study was to evaluate the time to approval for prescribed treatment of HCV infection. A retrospective observational study was conducted including patients treated for HCV infection by clinic providers who received at least 1 oral direct-acting antiviral HCV medication. Patients were divided into 2 groups, based on whether they were treated before or after the implementation of the team-based approach. Student t tests were used to compare average wait times before and after the intervention. The sample included 180 patients, 68 treated before the intervention and 112 patients who initiated therapy after. All patients sampled required prior authorization approval by a third-party payer to begin therapy. There was a statistically significant reduction (P = .02) in average wait time in the postintervention group (15.6 ± 12.1 days) once adjusted using dates of approval. Pharmacy collaboration may provide increases in efficiency in provider prior authorization practices and reduced wait time for patients to begin treatment.

  8. Reproducing kernel Hilbert spaces of Gaussian priors

    NARCIS (Netherlands)

    Vaart, van der A.W.; Zanten, van J.H.; Clarke, B.; Ghosal, S.

    2008-01-01

    We review definitions and properties of reproducing kernel Hilbert spaces attached to Gaussian variables and processes, with a view to applications in nonparametric Bayesian statistics using Gaussian priors. The rate of contraction of posterior distributions based on Gaussian priors can be described

  9. Prior Knowledge Assessment Guide

    Science.gov (United States)

    2014-12-01

    assessment in a reasonable amount of time. Hands-on assessments can be extremely diverse in makeup and administration depending on the subject matter...DEVELOPING AND USING PRIOR KNOWLEDGE ASSESSMENTS TO TAILOR TRAINING D-3 ___ Brush and scrub ___ Orchards ___ Rice

  10. Fractional Gaussian noise: Prior specification and model comparison

    KAUST Repository

    Sørbye, Sigrunn Holbek

    2017-07-07

    Fractional Gaussian noise (fGn) is a stationary stochastic process used to model antipersistent or persistent dependency structures in observed time series. Properties of the autocovariance function of fGn are characterised by the Hurst exponent (H), which, in Bayesian contexts, typically has been assigned a uniform prior on the unit interval. This paper argues why a uniform prior is unreasonable and introduces the use of a penalised complexity (PC) prior for H. The PC prior is computed to penalise divergence from the special case of white noise and is invariant to reparameterisations. An immediate advantage is that the exact same prior can be used for the autocorrelation coefficient ϕ(symbol) of a first-order autoregressive process AR(1), as this model also reflects a flexible version of white noise. Within the general setting of latent Gaussian models, this allows us to compare an fGn model component with AR(1) using Bayes factors, avoiding the confounding effects of prior choices for the two hyperparameters H and ϕ(symbol). Among others, this is useful in climate regression models where inference for underlying linear or smooth trends depends heavily on the assumed noise model.

  11. Fractional Gaussian noise: Prior specification and model comparison

    KAUST Repository

    Sø rbye, Sigrunn Holbek; Rue, Haavard

    2017-01-01

    Fractional Gaussian noise (fGn) is a stationary stochastic process used to model antipersistent or persistent dependency structures in observed time series. Properties of the autocovariance function of fGn are characterised by the Hurst exponent (H), which, in Bayesian contexts, typically has been assigned a uniform prior on the unit interval. This paper argues why a uniform prior is unreasonable and introduces the use of a penalised complexity (PC) prior for H. The PC prior is computed to penalise divergence from the special case of white noise and is invariant to reparameterisations. An immediate advantage is that the exact same prior can be used for the autocorrelation coefficient ϕ(symbol) of a first-order autoregressive process AR(1), as this model also reflects a flexible version of white noise. Within the general setting of latent Gaussian models, this allows us to compare an fGn model component with AR(1) using Bayes factors, avoiding the confounding effects of prior choices for the two hyperparameters H and ϕ(symbol). Among others, this is useful in climate regression models where inference for underlying linear or smooth trends depends heavily on the assumed noise model.

  12. Learning priors for Bayesian computations in the nervous system.

    Directory of Open Access Journals (Sweden)

    Max Berniker

    Full Text Available Our nervous system continuously combines new information from our senses with information it has acquired throughout life. Numerous studies have found that human subjects manage this by integrating their observations with their previous experience (priors in a way that is close to the statistical optimum. However, little is known about the way the nervous system acquires or learns priors. Here we present results from experiments where the underlying distribution of target locations in an estimation task was switched, manipulating the prior subjects should use. Our experimental design allowed us to measure a subject's evolving prior while they learned. We confirm that through extensive practice subjects learn the correct prior for the task. We found that subjects can rapidly learn the mean of a new prior while the variance is learned more slowly and with a variable learning rate. In addition, we found that a Bayesian inference model could predict the time course of the observed learning while offering an intuitive explanation for the findings. The evidence suggests the nervous system continuously updates its priors to enable efficient behavior.

  13. Predictors of Receiving a Prosthesis for Adults With Above-Knee Amputations in a Well-Defined Population.

    Science.gov (United States)

    Mundell, Benjamin F; Kremers, Hilal Maradit; Visscher, Sue; Hoppe, Kurtis M; Kaufman, Kenton R

    2016-08-01

    Prior studies have identified age as a factor in determining an individual's likelihood of receiving a prosthesis following a lower limb amputation. These studies are limited to specific subsets of the general population and are unable to account for preamputation characteristics within their study populations. Our study seeks to determine the effect of preamputation characteristics on the probability of receiving a prosthesis for the general population in the United States. To identify preamputation characteristics that predict of the likelihood of receiving a prosthesis following an above-knee amputation. A retrospective, population-based cohort study. Olmsted County, Minnesota (2010 population: 144,248). Individuals (n = 93) over the age of 18 years who underwent an above-knee amputation, that is, knee disarticulation or transfemoral amputation, while residing in Olmsted County, MN, between 1987 and 2013. Characteristics affecting the receipt of a prosthesis were analyzed using a logistic regression and a random forest algorithm for classification trees. Preamputation characteristics included age, gender, amputation etiology, year of amputation, mobility, cognitive ability, comorbidities, and time between surgery and the prosthesis decision. The association of preamputation characteristics with the receipt of a prosthesis following an above-knee amputation. Twenty-four of the participants received a prosthesis. The odds of receiving a prosthesis were almost 30 times higher in those able to walk independently prior to an amputation relative to those who could not walk independently. A 10-year increase in age was associated with a 53.8% decrease in the likelihood of being fit for a prosthesis (odds ratio = 0.462, P =.030). Time elapsed between surgery and the prosthesis decision was associated with a rise in probability of receiving a prosthesis for the first 3 months in the random forest algorithm. No other observed characteristics were associated with receipt

  14. Valid MR imaging predictors of prior knee arthroscopy

    International Nuclear Information System (INIS)

    Discepola, Federico; Le, Huy B.Q.; Park, John S.; Clopton, Paul; Knoll, Andrew N.; Austin, Matthew J.; Resnick, Donald L.

    2012-01-01

    To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. κ statistics were used to analyze inter-observer agreement. Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p ≥ 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy. (orig.)

  15. Valid MR imaging predictors of prior knee arthroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Discepola, Federico; Le, Huy B.Q. [McGill University Health Center, Jewsih General Hospital, Division of Musculoskeletal Radiology, Montreal, Quebec (Canada); Park, John S. [Annapolis Radiology Associates, Division of Musculoskeletal Radiology, Annapolis, MD (United States); Clopton, Paul; Knoll, Andrew N.; Austin, Matthew J.; Resnick, Donald L. [University of California San Diego (UCSD), Division of Musculoskeletal Radiology, San Diego, CA (United States)

    2012-01-15

    To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. {kappa} statistics were used to analyze inter-observer agreement. Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p {>=} 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy. (orig.)

  16. Stereotactic Ablative Radiosurgery for Locally-Advanced or Recurrent Skull Base Malignancies with Prior External Beam Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Karen Mann Xu

    2015-03-01

    Full Text Available Purpose: Stereotactic ablative radiotherapy (SABR is an attractive modality to treat malignancies invading the skull base as it can deliver a highly conformal dose with minimal toxicity. However, variation exists in the prescribed dose and fractionation. The purpose of our study is to examine the local control, survival and toxicities in SABR for the treatment of malignant skull base tumors. Methods and Materials: A total of 31 patients and 40 locally-advanced or recurrent head and neck malignancies involving the skull base treated with a common SABR regimen which delivers a radiation dose of 44 Gy in 5 fractions from January 1st, 2004 to December 31st, 2013 were retrospectively reviewed. The local control rate (LC, progression-free survival rate (PFS, overall survival rate (OS and toxicities were reported.Results: The median follow-up time of all patients was 11.4 months (range: 0.6-67.2 months. The median tumor volume was 27 cm3 (range: 2.4-205 cm3. All patients received prior EBRT with a median radiation dose of 64 Gy (range: 24-75.6 Gy delivered in 12 to 42 fractions. 20 patients had surgeries prior to SABR. 19 patients received chemotherapy. Specifically, 8 patients received concurrent cetuximab (ErbituxTM with SABR. The median time-to-progression (TTP was 3.3 months (range: 0-16.9 months. For the 29 patients (93.5% who died, the median time from the end of first SABR to death was 10.3 months (range: 0.5-41.4 months. The estimated 1-year overall survival (OS rate was 35%. The estimated 2-year OS rate was 12%. Treatment was well-tolerated without grade 4 or 5 treatment-related toxicities.Conclusions: SABR has been shown to achieve low toxicities in locally-advanced or recurrent, previously irradiated head and neck malignancies invading the skull base.

  17. Generalized multiple kernel learning with data-dependent priors.

    Science.gov (United States)

    Mao, Qi; Tsang, Ivor W; Gao, Shenghua; Wang, Li

    2015-06-01

    Multiple kernel learning (MKL) and classifier ensemble are two mainstream methods for solving learning problems in which some sets of features/views are more informative than others, or the features/views within a given set are inconsistent. In this paper, we first present a novel probabilistic interpretation of MKL such that maximum entropy discrimination with a noninformative prior over multiple views is equivalent to the formulation of MKL. Instead of using the noninformative prior, we introduce a novel data-dependent prior based on an ensemble of kernel predictors, which enhances the prediction performance of MKL by leveraging the merits of the classifier ensemble. With the proposed probabilistic framework of MKL, we propose a hierarchical Bayesian model to learn the proposed data-dependent prior and classification model simultaneously. The resultant problem is convex and other information (e.g., instances with either missing views or missing labels) can be seamlessly incorporated into the data-dependent priors. Furthermore, a variety of existing MKL models can be recovered under the proposed MKL framework and can be readily extended to incorporate these priors. Extensive experiments demonstrate the benefits of our proposed framework in supervised and semisupervised settings, as well as in tasks with partial correspondence among multiple views.

  18. Calibrated birth-death phylogenetic time-tree priors for bayesian inference.

    Science.gov (United States)

    Heled, Joseph; Drummond, Alexei J

    2015-05-01

    Here we introduce a general class of multiple calibration birth-death tree priors for use in Bayesian phylogenetic inference. All tree priors in this class separate ancestral node heights into a set of "calibrated nodes" and "uncalibrated nodes" such that the marginal distribution of the calibrated nodes is user-specified whereas the density ratio of the birth-death prior is retained for trees with equal values for the calibrated nodes. We describe two formulations, one in which the calibration information informs the prior on ranked tree topologies, through the (conditional) prior, and the other which factorizes the prior on divergence times and ranked topologies, thus allowing uniform, or any arbitrary prior distribution on ranked topologies. Although the first of these formulations has some attractive properties, the algorithm we present for computing its prior density is computationally intensive. However, the second formulation is always faster and computationally efficient for up to six calibrations. We demonstrate the utility of the new class of multiple-calibration tree priors using both small simulations and a real-world analysis and compare the results to existing schemes. The two new calibrated tree priors described in this article offer greater flexibility and control of prior specification in calibrated time-tree inference and divergence time dating, and will remove the need for indirect approaches to the assessment of the combined effect of calibration densities and tree priors in Bayesian phylogenetic inference. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  19. Effect of bystander CPR initiation prior to the emergency call on ROSC and 30day survival-An evaluation of 548 emergency calls.

    Science.gov (United States)

    Viereck, Søren; Palsgaard Møller, Thea; Kjær Ersbøll, Annette; Folke, Fredrik; Lippert, Freddy

    2017-02-01

    This study aimed at evaluating if time for initiation of bystander cardiopulmonary resuscitation (CPR) - prior to the emergency call (CPR prior ) versus during the emergency call following dispatcher-assisted CPR (CPR during ) - was associated with return of spontaneous circulation (ROSC) and 30-day survival. The secondary aim was to identify predictors of CPR prior . This observational study evaluated out-of-hospital cardiac arrests (OHCA) occurring in the Capital Region of Denmark from 01.01.2013 to 31.12.2013. OHCAs were linked to emergency medical dispatch centre records and corresponding emergency calls were evaluated. Multivariable logistic regression analyses were applied to evaluate the association between time for initiation of bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of CPR prior . The study included 548 emergency calls for OHCA patients receiving bystander CPR, 34.9% (n=191) in the CPR prior group and 65.1% (n=357) in the CPR during group. Multivariable analyses showed no difference in ROSC (OR=0.88, 95% CI: 0.56-1.38) or 30-day survival (OR=1.14, 95% CI: 0.68-1.92) between CPR prior and CPR during . Predictors positively associated with CPR prior included witnessed OHCA and healthcare professional bystanders. Predictors negatively associated with CPR prior included residential location, solitary bystanders, and bystanders related to the patient. The majority of bystander CPR (65%) was initiated during the emergency call, following dispatcher-assisted CPR instructions. Whether bystander CPR was initiated prior to emergency call versus during the emergency call following dispatcher-assisted CPR was not associated with ROSC or 30-day survival. Dispatcher-assisted CPR was especially beneficial for the initiation of bystander CPR in residential areas. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  20. Hydrology of the Chicod Creek basin, North Carolina, prior to channel improvements

    Science.gov (United States)

    Simmons, Clyde E.; Aldridge, Mary C.

    1980-01-01

    Extensive modification and excavation of stream channels in the 6-square mile Chicod Creek basin began in mid-1979 to reduce flooding and improve stream runoff conditions. The effects of channel improvements on this Coastal Pain basin 's hydrology will be determined from data collected prior to, during, and for several years following channel alternations. This report summarizes the findings of data collected prior to these improvements. During the 3-year study period, flow data collected from four stream gaging stations in the basin show that streams are dry approximately 10 percent of the time. Chemical analyses of water samples from the streams and from eight shallow groundwater observation wells indicate that water discharge from the surficial aquifer is the primary source of streamflow during rainless periods. Concentrations of Kjeldahl nitrogen, total nitrogen, and total phosphorus were often 5 to 10 times greater at Chicod Creek sites than those at nearby baseline sites. It is probable that runoff from farming and livestock operations contributes significantly to these elevated concentrations in Chicod Creek. The only pesticides detected in stream water were low levels of DDT and dieldrin, which occurred during storm runoff. A much wider range of pesticides, however, are found associated with streambed materials. The ratio of fecal coliform counts to those of fecal streptococcus indicate that the streams receive fecal wastes from livestock and poultry operations.

  1. Factors associated with contingency management adoption among opioid treatment providers receiving a comprehensive implementation strategy.

    Science.gov (United States)

    Becker, Sara J; Kelly, Lourah M; Kang, Augustine W; Escobar, Katherine I; Squires, Daniel D

    2018-03-29

    Contingency management (CM) is an evidence-based behavioral intervention for opioid use disorders (OUDs); however, CM adoption in OUD treatment centers remains low due to barriers at patient, provider, and organizational levels. In a recent trial, OUD treatment providers who received the Science to Service Laboratory (SSL), a multilevel implementation strategy developed by a federally funded addiction training center, had significantly greater odds of CM adoption than providers who received training as usual. This study examined whether CM adoption frequency varied as a function of provider sociodemographic characteristics (i.e., age, race/ethnicity, licensure) and perceived barriers to adoption (i.e., patient-, provider-, organization-level) among providers receiving the SSL in an opioid treatment program. Thirty-nine providers (67% female, 77% non-Hispanic white, 72% with specialty licensure, M age = 42 [SD = 11.46]) received the SSL, which consisted of didactic training, performance feedback, specialized training of internal change champions, and external coaching. Providers completed a comprehensive baseline assessment and reported on their adoption of CM biweekly for 52 weeks. Providers reported using CM an average of nine 2-week intervals (SD = 6.35). Hierarchical multiple regression found that providers identifying as younger, non-Hispanic white, and without addiction-related licensure all had higher levels of CM adoption frequency. Higher perceived patient-level barriers predicted lower levels of CM adoption frequency, whereas provider- and organization-level barriers were not significant predictors. The significant effect of age on CM adoption frequency was consistent with prior research on predictors of evidence-based practice adoption, whereas the effect of licensure was counter to prior research. The finding that CM adoption frequency was lower among racially/ethnically diverse providers was not expected and suggests that the SSL may require adaptation

  2. Improving Open Access through Prior Learning Assessment

    Science.gov (United States)

    Yin, Shuangxu; Kawachi, Paul

    2013-01-01

    This paper explores and presents new data on how to improve open access in distance education through using prior learning assessments. Broadly there are three types of prior learning assessment (PLAR): Type-1 for prospective students to be allowed to register for a course; Type-2 for current students to avoid duplicating work-load to gain…

  3. Training shortest-path tractography: Automatic learning of spatial priors

    DEFF Research Database (Denmark)

    Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde

    2016-01-01

    Tractography is the standard tool for automatic delineation of white matter tracts from diffusion weighted images. However, the output of tractography often requires post-processing to remove false positives and ensure a robust delineation of the studied tract, and this demands expert prior...... knowledge. Here we demonstrate how such prior knowledge, or indeed any prior spatial information, can be automatically incorporated into a shortest-path tractography approach to produce more robust results. We describe how such a prior can be automatically generated (learned) from a population, and we...

  4. Acquisition of multiple prior distributions in tactile temporal order judgment

    Directory of Open Access Journals (Sweden)

    Yasuhito eNagai

    2012-08-01

    Full Text Available The Bayesian estimation theory proposes that the brain acquires the prior distribution of a task and integrates it with sensory signals to minimize the effect of sensory noise. Psychophysical studies have demonstrated that our brain actually implements Bayesian estimation in a variety of sensory-motor tasks. However, these studies only imposed one prior distribution on participants within a task period. In this study, we investigated the conditions that enable the acquisition of multiple prior distributions in temporal order judgment (TOJ of two tactile stimuli across the hands. In Experiment 1, stimulation intervals were randomly selected from one of two prior distributions (biased to right hand earlier and biased to left hand earlier in association with color cues (green and red, respectively. Although the acquisition of the two priors was not enabled by the color cues alone, it was significant when participants shifted their gaze (above or below in response to the color cues. However, the acquisition of multiple priors was not significant when participants moved their mouths (opened or closed. In Experiment 2, the spatial cues (above and below were used to identify which eye position or retinal cue position was crucial for the eye-movement-dependent acquisition of multiple priors in Experiment 1. The acquisition of the two priors was significant when participants moved their gaze to the cues (i.e., the cue positions on the retina were constant across the priors, as well as when participants did not shift their gazes (i.e., the cue positions on the retina changed according to the priors. Thus, both eye and retinal cue positions were effective in acquiring multiple priors. Based on previous neurophysiological reports, we discuss possible neural correlates that contribute to the acquisition of multiple priors.

  5. Tolerance and effectiveness of two methods for colonic preparation prior to surgery: Fosfoda® vs Solución Evacuante Bohm®

    Directory of Open Access Journals (Sweden)

    Silvia C. Egea González

    2004-12-01

    Full Text Available An adequate mechanical colon preparation prior to abdominal surgery is mandatory in order to prevent infectious and mechanical complications after surgery. The standard strategies for mechanical bowel preparation are based in the use of oral solutions.Aim: To compare effectiveness, security and tolerance of two methods for mechanical bowel preparation (Fosfosoda® and Solución Evacuante Bohm®.Methodology: Descriptive study of the prospective cohort of patients admitted for surgery requiring previous bowel preparation in the Fundación Hospital Alcorcón (Madrid, between October 01 and June 02 Results: Within patients who received Fosfosoda® as preparative solution (24/47%, 66% did not experience associated symthomatology at all, but 5 (21% experienced vomiting. The bowel cleaning quality was classified as good or excellent in 92% of them according to nursing evaluation and as excellent in 70% according to surgeon evaluation. Due to an inadequate bowel cleaning 2 patients (8% required an enema administration prior to surgery. Within patients who were treated with Solución Evacuante Bohm® (27/53%, 57% experienced no associated symthoms, 2 of them (7,5% experienced vomiting, the bowel cleaning quality was classified as good/excellent in 85% by nurses and as excellent in 73% by surgeons. Within this group 3 (11% patients required an enema administration prior to surgery.Conclusions: Bowel cleaning was slightly better in patients who were treated with Fosfoda®, nevertheless the tolerance was better within patients who received Solution Evacuante Bohm®.

  6. Novel use of pleural ultrasound can identify malignant entrapped lung prior to effusion drainage.

    Science.gov (United States)

    Salamonsen, Matthew R; Lo, Ada K C; Ng, Arnold C T; Bashirzadeh, Farzad; Wang, William Y S; Fielding, David I K

    2014-11-01

    The presence of entrapped lung changes the appropriate management of malignant pleural effusion from pleurodesis to insertion of an indwelling pleural catheter. No methods currently exist to identify entrapped lung prior to effusion drainage. Our objectives were to develop a method to identify entrapped lung using tissue movement and deformation (strain) analysis with ultrasonography and compare it to the existing technique of pleural elastance (PEL). Prior to drainage, 81 patients with suspected malignant pleural effusion underwent thoracic ultrasound using an echocardiogram machine. Images of the atelectatic lower lobe were acquired during breath hold, allowing motion and strain related to the cardiac impulse to be analyzed using motion mode (M mode) and speckle-tracking imaging, respectively. PEL was measured during effusion drainage. The gold-standard diagnosis of entrapped lung was the consensus opinion of two interventional pulmonologists according to postdrainage imaging. Participants were randomly divided into development and validation sets. Both total movement and strain were significantly reduced in entrapped lung. Using data from the development set, the area under the receiver-operating curves for the diagnosis of entrapped lung was 0.86 (speckle tracking), 0.79 (M mode), and 0.69 (PEL). Using respective cutoffs of 6%, 1 mm, and 19 cm H2O on the validation set, the sensitivity/specificity was 71%/85% (speckle tracking), 50%/85% (M mode), and 40%/100% (PEL). This novel ultrasound technique can identify entrapped lung prior to effusion drainage, which could allow appropriate choice of definitive management (pleurodesis vs indwelling catheter), reducing the number of interventions required to treat malignant pleural effusion.

  7. Locally advanced cervix cancer: chemotherapy prior to definitive surgery or radiotherapy. A single institutional experience

    International Nuclear Information System (INIS)

    MacLeod, C.; O'Donnell, A.; Tattersall, M.H.N.; Dalrymple, C.; Firth, I.

    2001-01-01

    Primary or neoadjuvant chemotherapy prior to definitive local therapy has potential advantages for locally advanced cervix cancer. It can down stage a cancer and allow definitive local therapy to be technically possible (surgery), or potentially more effective (radiotherapy). It can also eradicate subclinical systemic metastases. This report reviews a single institution's experience of neoadjuvant chemotherapy prior to definitive local therapy for cervix cancer over a 13-year period. One hundred and six patients were treated with this intent. The patients were analysed for their response to chemotherapy, treatment received, survival, relapse and toxicity. The chemotherapy was feasible and the majority of patients had a complete or partial response (58.5%). Eight patients did not proceed to local treatment. Forty-six patients had definitive surgery and 52 had definitive radiotherapy. The 5-year overall survival was 27% and the majority of patients died with disease. The first site of relapse was usually in the pelvis (46.2%). Late complications that required ongoing medical therapy (n = 6) or surgical intervention (n = 2) were recorded in eight patients (7.5%). On univariate analysis stage (P= 0.04), tumour size (P = 0.01), lymph node status (P=0.003), response to chemotherapy (P = 0.045) and treatment (P = 0.003) were all significant predictors of survival. On multivariate analysis, tumour size (P < 0.0001) and nodal status (P = 0.02) were significant predictors of survival. Despite the impressive responses to chemotherapy of advanced cervix cancer, there is evidence from randomized trials that it does not improve or compromise survival prior to radiotherapy. As its role prior to surgery remains unclear, it should not be used in this setting outside a prospective randomized trial. Copyright (2001) Blackwell Science Pty Ltd

  8. Prospective pre- and post-race evaluation of biochemical, electrophysiologic, and echocardiographic indices in 30 racing thoroughbred horses that received furosemide.

    Science.gov (United States)

    Gunther-Harrington, Catherine T; Arthur, Rick; Estell, Krista; Martinez Lopez, Beatriz; Sinnott, Alexandra; Ontiveros, Eric; Varga, Anita; Stern, Joshua A

    2018-01-18

    Exercise induced cardiac fatigue (EICF) and cardiac dysrhythmias are well described conditions identified in high-level human athletes that increase in frequency with intensity and duration of exercise. Identification of these conditions requires an understanding of normal pre- and post-race cardiac assessment values. The objectives of this study were to (1) characterize selected indices of cardiac function, electrophysiologic parameters, and biochemical markers of heart dysfunction prior to and immediately after high level racing in Thoroughbred horses receiving furosemide; and (2) create pre- and post-race reference values in order to make recommendations on possible screening practices for this population in the future. Thirty Thoroughbred horses were enrolled in the study with an age range of 3-6 years. All horses received furosemide prior to racing. Physical exams, ECGs, and echocardiograms were performed prior to racing (T0) and within 30-60 min following the race (T1). Blood samples were obtained at T0, T1, 4 h post-race (T4) and 24 h after the race (T24). Electrolytes, hematocrit, cardiac troponin I, and partial pressure CO2 values were obtained at all time points. Heart rate was significantly increased post-race compared to baseline value with a median difference of 49 bpm, 95% CI [31,58],(P horses demonstrating regurgitation through the aorta and AV valves was noted. Systolic function measured by fractional shortening increased significantly with a mean difference of 7.9%, 95% CI [4.8, 10.9], (P horse served as its own control, as such the possible effect of regression to the mean cannot be ruled out. The reference intervals generated in this study may be used to identify selected echocardiographic and electrocardiographic abnormalities in racing horses receiving furosemide.

  9. Prior-based artifact correction (PBAC) in computed tomography

    International Nuclear Information System (INIS)

    Heußer, Thorsten; Brehm, Marcus; Ritschl, Ludwig; Sawall, Stefan; Kachelrieß, Marc

    2014-01-01

    Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data

  10. Impact of preoperative patient characteristics on posturethroplasty recurrence: The significance of stricture length and prior treatments

    Directory of Open Access Journals (Sweden)

    Jibril Oyekunle Bello

    2016-01-01

    Full Text Available Introduction: Urethral strictures are common in urologic practice of Sub-Saharan Africa including Nigeria. We determine the rate of stricture recurrence following urethroplasty for anterior urethral strictures and evaluate preoperative variables that predict of stricture recurrence in our practice. Subjects and Methods: Thirty-six men who had urethroplasty for proven anterior urethral stricture disease between February 2012 and January 2015 were retrospectively analyzed. Preoperative factors including age, socioeconomic factors, comorbidities, etiology of strictures, stricture location, stricture length, periurethral spongiofibrosis, and prior stricture treatments were assessed for independent predictors of stricture recurrence. Results: The median age was 49.5 years (range 21-90, median stricture length was 4 cm (range 1-18 cm and the overall recurrence rate was 27.8%. Postinfectious strictures, pan urethral strictures or multiple strictures involving the penile and bulbar urethra were more common. Most patients had penile circular fasciocutaneous flap urethroplasty. Following univariate analysis of potential preoperative predictors of stricture recurrence, stricture length, and prior treatments with dilations or urethrotomies were found to be significantly associated with stricture recurrence. On multivariate analysis, they both remained statistically significant. Patients who had prior treatments had greater odds of having a recurrent stricture (odds ratio 18, 95% confidence interval [CI] 1.4-224.3. Stricture length was dichotomized based on receiver operating characteristic (ROC analysis, and strictures of length ≥5 cm had significantly greater recurrence (area under ROC curve of 0.825, 95% CI 0.690-0.960, P = 0.032. Conclusion: Patients who had prior dilatations or urethrotomies and those with long strictures particularly strictures ≥5 cm have significantly greater odds of developing a recurrence following urethroplasty in Nigerian

  11. Web-Based Education Prior to Outpatient Orthopaedic Surgery Enhances Early Patient Satisfaction Scores: A Prospective Randomized Controlled Study.

    Science.gov (United States)

    van Eck, Carola F; Toor, Aneet; Banffy, Michael B; Gambardella, Ralph A

    2018-01-01

    A good patient-surgeon relationship relies on adequate preoperative education and counseling. Several multimedia resources, such as web-based education tools, have become available to enhance aspects of perioperative care. The purpose of this study was to evaluate the effect of an interactive web-based education tool on perioperative patient satisfaction scores after outpatient orthopaedic surgery. It was hypothesized that web-based education prior to outpatient orthopaedic surgery enhances patient satisfaction scores. Randomized controlled trial; Level of evidence, 1. All patients undergoing knee arthroscopy with meniscectomy, chondroplasty, or anterior cruciate ligament reconstruction or shoulder arthroscopy with rotator cuff repair were eligible for inclusion and were randomized to the study or control group. The control group received routine education by the surgeon, whereas the study group received additional web-based education. At the first postoperative visit, all patients completed the OAS CAHPS (Outpatient and Ambulatory Surgery Consumer Assessment of Healthcare Providers and Systems) survey. Differences in patient satisfaction scores between the study and control groups were determined with an independent t test. A total of 177 patients were included (104 [59%] males; mean age, 42 ± 14 years); 87 (49%) patients were randomized to receive additional web-based education. Total patient satisfaction score was significantly higher in the study group (97 ± 5) as compared with the control group (94 ± 8; P = .019), specifically for the OAS CAHPS core measure "recovery" (92 ± 13 vs 82 ± 23; P = .001). Age, sex, race, workers' compensation status, education level, overall health, emotional health, procedure type and complexity, and addition of a video did not influence patient satisfaction scores. Supplemental web-based patient education prior to outpatient orthopaedic surgery enhances patient satisfaction scores.

  12. Diversity receiver

    NARCIS (Netherlands)

    2005-01-01

    The invention is directed to the reception of high rate radio signals (for example DVB-T signals) while the receiver is moving at a high speed (for example in or with a car). Two or more antennas (12, 16) are closely spaced and arranged behind each other in the direction of motion (v) for receiving

  13. Estimating Functions with Prior Knowledge, (EFPK) for diffusions

    DEFF Research Database (Denmark)

    Nolsøe, Kim; Kessler, Mathieu; Madsen, Henrik

    2003-01-01

    In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction of a...... of an estimating function. It may be useful when the full Bayesian analysis is difficult to carry out for computational reasons. This is almost always the case for diffusions, which is the focus of this paper, though the method applies in other settings.......In this paper a method is formulated in an estimating function setting for parameter estimation, which allows the use of prior information. The main idea is to use prior knowledge of the parameters, either specified as moments restrictions or as a distribution, and use it in the construction...

  14. Arthur Prior and 'Now'

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Jørgensen, Klaus Frovin

    2016-01-01

    ’s search led him through the work of Castañeda, and back to his own work on hybrid logic: the first made temporal reference philosophically respectable, the second made it technically feasible in a modal framework. With the aid of hybrid logic, Prior built a bridge from a two-dimensional UT calculus...

  15. Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisherTM magnetic particle processor prior to genome sequencing

    International Nuclear Information System (INIS)

    Maekinen, Johanna; Marttila, Harri; Viljanen, Matti K.

    2001-01-01

    Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher TM magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher TM magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification

  16. Self-prior strategy for organ reconstruction in fluorescence molecular tomography.

    Science.gov (United States)

    Zhou, Yuan; Chen, Maomao; Su, Han; Luo, Jianwen

    2017-10-01

    The purpose of this study is to propose a strategy for organ reconstruction in fluorescence molecular tomography (FMT) without prior information from other imaging modalities, and to overcome the high cost and ionizing radiation caused by the traditional structural prior strategy. The proposed strategy is designed as an iterative architecture to solve the inverse problem of FMT. In each iteration, a short time Fourier transform (STFT) based algorithm is used to extract the self-prior information in the space-frequency energy spectrum with the assumption that the regions with higher fluorescence concentration have larger energy intensity, then the cost function of the inverse problem is modified by the self-prior information, and lastly an iterative Laplacian regularization algorithm is conducted to solve the updated inverse problem and obtains the reconstruction results. Simulations and in vivo experiments on liver reconstruction are carried out to test the performance of the self-prior strategy on organ reconstruction. The organ reconstruction results obtained by the proposed self-prior strategy are closer to the ground truth than those obtained by the iterative Tikhonov regularization (ITKR) method (traditional non-prior strategy). Significant improvements are shown in the evaluation indexes of relative locational error (RLE), relative error (RE) and contrast-to-noise ratio (CNR). The self-prior strategy improves the organ reconstruction results compared with the non-prior strategy and also overcomes the shortcomings of the traditional structural prior strategy. Various applications such as metabolic imaging and pharmacokinetic study can be aided by this strategy.

  17. Heuristics as Bayesian inference under extreme priors.

    Science.gov (United States)

    Parpart, Paula; Jones, Matt; Love, Bradley C

    2018-05-01

    Simple heuristics are often regarded as tractable decision strategies because they ignore a great deal of information in the input data. One puzzle is why heuristics can outperform full-information models, such as linear regression, which make full use of the available information. These "less-is-more" effects, in which a relatively simpler model outperforms a more complex model, are prevalent throughout cognitive science, and are frequently argued to demonstrate an inherent advantage of simplifying computation or ignoring information. In contrast, we show at the computational level (where algorithmic restrictions are set aside) that it is never optimal to discard information. Through a formal Bayesian analysis, we prove that popular heuristics, such as tallying and take-the-best, are formally equivalent to Bayesian inference under the limit of infinitely strong priors. Varying the strength of the prior yields a continuum of Bayesian models with the heuristics at one end and ordinary regression at the other. Critically, intermediate models perform better across all our simulations, suggesting that down-weighting information with the appropriate prior is preferable to entirely ignoring it. Rather than because of their simplicity, our analyses suggest heuristics perform well because they implement strong priors that approximate the actual structure of the environment. We end by considering how new heuristics could be derived by infinitely strengthening the priors of other Bayesian models. These formal results have implications for work in psychology, machine learning and economics. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Prospective regularization design in prior-image-based reconstruction

    International Nuclear Information System (INIS)

    Dang, Hao; Siewerdsen, Jeffrey H; Stayman, J Webster

    2015-01-01

    Prior-image-based reconstruction (PIBR) methods leveraging patient-specific anatomical information from previous imaging studies and/or sequences have demonstrated dramatic improvements in dose utilization and image quality for low-fidelity data. However, a proper balance of information from the prior images and information from the measurements is required (e.g. through careful tuning of regularization parameters). Inappropriate selection of reconstruction parameters can lead to detrimental effects including false structures and failure to improve image quality. Traditional methods based on heuristics are subject to error and sub-optimal solutions, while exhaustive searches require a large number of computationally intensive image reconstructions. In this work, we propose a novel method that prospectively estimates the optimal amount of prior image information for accurate admission of specific anatomical changes in PIBR without performing full image reconstructions. This method leverages an analytical approximation to the implicitly defined PIBR estimator, and introduces a predictive performance metric leveraging this analytical form and knowledge of a particular presumed anatomical change whose accurate reconstruction is sought. Additionally, since model-based PIBR approaches tend to be space-variant, a spatially varying prior image strength map is proposed to optimally admit changes everywhere in the image (eliminating the need to know change locations a priori). Studies were conducted in both an ellipse phantom and a realistic thorax phantom emulating a lung nodule surveillance scenario. The proposed method demonstrated accurate estimation of the optimal prior image strength while achieving a substantial computational speedup (about a factor of 20) compared to traditional exhaustive search. Moreover, the use of the proposed prior strength map in PIBR demonstrated accurate reconstruction of anatomical changes without foreknowledge of change locations in

  19. GENERAL ASPECTS REGARDING THE PRIOR DISCIPLINARY RESEARCH

    Directory of Open Access Journals (Sweden)

    ANDRA PURAN (DASCĂLU

    2012-05-01

    Full Text Available Disciplinary research is the first phase of the disciplinary action. According to art. 251 paragraph 1 of the Labour Code no disciplinary sanction may be ordered before performing the prior disciplinary research.These regulations provide an exception: the sanction of written warning. The current regulations in question, kept from the old regulation, provides a protection for employees against abuses made by employers, since sanctions are affecting the salary or the position held, or even the development of individual employment contract. Thus, prior research of the fact that is a misconduct, before a disciplinary sanction is applied, is an essential condition for the validity of the measure ordered. Through this study we try to highlight some general issues concerning the characteristics, processes and effects of prior disciplinary research.

  20. Bayesian Prior Probability Distributions for Internal Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G.; Inkret, W.C.; Little, T.T.; Martz, H.F.; Schillaci, M.E

    2001-07-01

    The problem of choosing a prior distribution for the Bayesian interpretation of measurements (specifically internal dosimetry measurements) is considered using a theoretical analysis and by examining historical tritium and plutonium urine bioassay data from Los Alamos. Two models for the prior probability distribution are proposed: (1) the log-normal distribution, when there is some additional information to determine the scale of the true result, and (2) the 'alpha' distribution (a simplified variant of the gamma distribution) when there is not. These models have been incorporated into version 3 of the Bayesian internal dosimetric code in use at Los Alamos (downloadable from our web site). Plutonium internal dosimetry at Los Alamos is now being done using prior probability distribution parameters determined self-consistently from population averages of Los Alamos data. (author)

  1. Spectrally Consistent Satellite Image Fusion with Improved Image Priors

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Aanæs, Henrik; Jensen, Thomas B.S.

    2006-01-01

    Here an improvement to our previous framework for satellite image fusion is presented. A framework purely based on the sensor physics and on prior assumptions on the fused image. The contributions of this paper are two fold. Firstly, a method for ensuring 100% spectrally consistency is proposed......, even when more sophisticated image priors are applied. Secondly, a better image prior is introduced, via data-dependent image smoothing....

  2. Bayesian Inference for Structured Spike and Slab Priors

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

    2014-01-01

    Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...

  3. Legal Regulation of Civil Servants in Russia and Germany Receiving Gifts

    Directory of Open Access Journals (Sweden)

    Svetlana Zimneva

    2015-01-01

    Full Text Available The article deals with the conflict between the provisions of the Criminal Code of the Russian Federation, where the minimum amount of the bribe is not defined, and the provision of the Federal Law ‘On State Civil Service of the Russian Federation,’ which, on the one hand, contains an absolute ban on civil servants receiving gifts and other types of remuneration, while, on the other hand, Art. 575 of the Civil Code of the Russian Federation admits a possibility for civil servants to receive gifts of an amount not exceeding 3,000 rubles in the performance of their official duties. This legal conflict necessitates conceptual clarification of such notions as ‘gift’ and ‘bribe.’The authors underline that a determining factor for establishing the legitimacy of the customary gifts given to government officials is whether the gifts were accepted by the officials, while executing their duties, without a prior agreement for an action or inaction. It is noted that the limitation of a gift’s maximum value to 3,000 rubles, as stated in the Civil Code of the Russian Federation, creates an opportunity to abuse or evade the law.The article presents a comparative study of European laws, more specifically dealing with the institute of donation, and Russian legislation regarding the possibility of civil servants receiving gifts. German law does not single out ‘customary gifts;’ it simply does not admit the possibility of giving gifts or the right to receive gifts by German civil servants.The authors have developed proposals to improve the legal regulation concerning the giving of gifts to government officials in Russia.

  4. Solar energy receiver

    Science.gov (United States)

    Schwartz, Jacob

    1978-01-01

    An improved long-life design for solar energy receivers provides for greatly reduced thermally induced stress and permits the utilization of less expensive heat exchanger materials while maintaining receiver efficiencies in excess of 85% without undue expenditure of energy to circulate the working fluid. In one embodiment, the flow index for the receiver is first set as close as practical to a value such that the Graetz number yields the optimal heat transfer coefficient per unit of pumping energy, in this case, 6. The convective index for the receiver is then set as closely as practical to two times the flow index so as to obtain optimal efficiency per unit mass of material.

  5. PET reconstruction via nonlocal means induced prior.

    Science.gov (United States)

    Hou, Qingfeng; Huang, Jing; Bian, Zhaoying; Chen, Wufan; Ma, Jianhua

    2015-01-01

    The traditional Bayesian priors for maximum a posteriori (MAP) reconstruction methods usually incorporate local neighborhood interactions that penalize large deviations in parameter estimates for adjacent pixels; therefore, only local pixel differences are utilized. This limits their abilities of penalizing the image roughness. To achieve high-quality PET image reconstruction, this study investigates a MAP reconstruction strategy by incorporating a nonlocal means induced (NLMi) prior (NLMi-MAP) which enables utilizing global similarity information of image. The present NLMi prior approximates the derivative of Gibbs energy function by an NLM filtering process. Specially, the NLMi prior is obtained by subtracting the current image estimation from its NLM filtered version and feeding the residual error back to the reconstruction filter to yield the new image estimation. We tested the present NLMi-MAP method with simulated and real PET datasets. Comparison studies with conventional filtered backprojection (FBP) and a few iterative reconstruction methods clearly demonstrate that the present NLMi-MAP method performs better in lowering noise, preserving image edge and in higher signal to noise ratio (SNR). Extensive experimental results show that the NLMi-MAP method outperforms the existing methods in terms of cross profile, noise reduction, SNR, root mean square error (RMSE) and correlation coefficient (CORR).

  6. Safety and utility of kyphoplasty prior to spine stereotactic radiosurgery for metastatic tumors: a clinical and dosimetric analysis.

    Science.gov (United States)

    Barzilai, Ori; DiStefano, Natalie; Lis, Eric; Yamada, Yoshiya; Lovelock, D Michael; Fontanella, Andrew N; Bilsky, Mark H; Laufer, Ilya

    2018-01-01

    OBJECTIVE The aim of this study was to evaluate the safety and efficacy of kyphoplasty treatment prior to spine stereotactic radiosurgery (SRS) in patients with spine metastases. METHODS A retrospective review of charts, radiology reports, and images was performed for all patients who received SRS (single fraction; either standalone or post-kyphoplasty) at a large tertiary cancer center between January 2012 and July 2015. Patient and tumor variables were documented, as well as treatment planning data and dosimetry. To measure the photon scatter due to polymethyl methacrylate, megavolt photon beam attenuation was determined experimentally as it passed through a kyphoplasty cement phantom. Corrected electron density values were recalculated and compared with uncorrected values. RESULTS Of 192 treatment levels in 164 unique patients who underwent single-fraction SRS, 17 (8.8%) were treated with kyphoplasty prior to radiation delivery to the index level. The median time from kyphoplasty to SRS was 22 days. Four of 192 treatments (2%) demonstrated local tumor recurrence or progression at the time of analysis. Of the 4 local failures, 1 patient had kyphoplasty prior to SRS. This recurrence occurred 18 months after SRS in the setting of widespread systemic disease and spinal tumor progression. Dosimetric review demonstrated a lower than average treatment dose for this case compared with the rest of the cohort. There were no significant differences in dosimetry analysis between the group of patients who underwent kyphoplasty prior to SRS and the remaining patients in the cohort. A preliminary analysis of polymethyl methacrylate showed that dosimetric errors due to uncorrected electron density values were insignificant. CONCLUSIONS In cases without epidural spinal cord compression, stabilization with cement augmentation prior to SRS is safe and does not alter the efficacy of the radiation or preclude physicians from adhering to SRS planning and contouring guidelines.

  7. Predictors for occlusion of cerebral AVMs following radiation therapy. Radiation dose and prior embolization, but not Spetzler-Martin grade

    Energy Technology Data Exchange (ETDEWEB)

    Knippen, Stefan; Putz, Florian; Semrau, Sabine; Lambrecht, Ulrike; Knippen, Arzu; Fietkau, Rainer [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Radiation Oncology, Erlangen (Germany); Buchfelder, Michael; Schlaffer, Sven [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany); Struffert, Tobias [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Neuroradiology, Erlangen (Germany)

    2017-03-15

    Intracranial arteriovenous malformations (AVMs) may show a harmful development. AVMs are treated by surgery, embolization, or radiation therapy. This study investigated obliteration rates and side effects in patients with AVMs treated by radiation therapy. A total of 40 cases treated between 2005 and 2013 were analyzed. Single-dose stereotactic radiosurgery (SRS) was received by 13 patients and 27 received hypofractionated stereotactic radiation therapy (HSRT). In 20 patients, endovascular embolization had been performed prior to irradiation and 24 patients (60 %) had a history of previous intracranial hemorrhage. Treatment resulted in complete obliteration (CO) in 23/40 cases and partial obliteration in 8/40. CO was achieved in 85 % of patients receiving SRS compared to 44 % of those receiving HSRT. In the HSRT group, a first indication of an influence of AVM volume on obliteration rate was found. Equivalent 2 Gy fraction doses (EQD2) >70 Gy showed an obliteration rate of 50 %. Prior embolization was significantly associated with a higher portion of CO (p = 0.032). Median latency period (24.2 vs. 26 months) until CO was similar in both groups (SRS vs. HSRT). The rate of intracranial hemorrhage in patients with no prior bleeding events was 0 %. Excellent obliteration rates were achieved by SRS. Consistent with the literature, this data analysis suggests that the results of HSRT are volume-dependent. Furthermore, regimens with EQD2 doses >70 Gy appear more likely to achieve obliteration than schemes with lower doses. The findings indicate that radiation therapy does not increase the risk of bleeding. Prior embolization may have a good prognostic impact. (orig.) [German] Intrakranielle arteriovenoese Malformationen (AVM) koennen einen komplikationsbehafteten Verlauf zeigen. AVMs sind mittels Operation, Embolisation oder Strahlentherapie behandelbar. Die Studie untersucht Obliterationsraten und Nebenwirkungen bestrahlter AVM-Patienten. Analysiert wurden 40 Faelle, die

  8. Bayesian Image Restoration Using a Large-Scale Total Patch Variation Prior

    Directory of Open Access Journals (Sweden)

    Yang Chen

    2011-01-01

    Full Text Available Edge-preserving Bayesian restorations using nonquadratic priors are often inefficient in restoring continuous variations and tend to produce block artifacts around edges in ill-posed inverse image restorations. To overcome this, we have proposed a spatial adaptive (SA prior with improved performance. However, this SA prior restoration suffers from high computational cost and the unguaranteed convergence problem. Concerning these issues, this paper proposes a Large-scale Total Patch Variation (LS-TPV Prior model for Bayesian image restoration. In this model, the prior for each pixel is defined as a singleton conditional probability, which is in a mixture prior form of one patch similarity prior and one weight entropy prior. A joint MAP estimation is thus built to ensure the iteration monotonicity. The intensive calculation of patch distances is greatly alleviated by the parallelization of Compute Unified Device Architecture(CUDA. Experiments with both simulated and real data validate the good performance of the proposed restoration.

  9. Is neoadjuvant chemotherapy prior to radio-chemotherapy beneficial in T4 anal carcinoma?

    Science.gov (United States)

    Moureau-Zabotto, L; Viret, F; Giovaninni, M; Lelong, B; Bories, E; Delpero, J R; Pesenti, C; Caillol, F; de Chaisemartin, C; Minsat, M; Monges, G; Sarran, A; Resbeut, M

    2011-07-01

    This study retrospectively describes the outcome of a series of 38 patients (pts) with T4 anal carcinoma exclusively treated by radio and chemotherapy. From 1992 to 2007, 38 pts with UST4-N0-2-M0 anal carcinoma were treated with exclusive radiotherapy and chemotherapy. All patients received external beam radiotherapy (EBRT) (median dose 45 Gy) with a concomitant chemotherapy (5-fluorouracil-cisplatin). Eleven patients received neo-adjuvant chemotherapy (5-fluorouracil-cisplatin). After 2-8 weeks, a 15-20 Gy boost was delivered either with EBRT (20 pts) or interstitial (192)Ir brachytherapy (18 pts). Mean follow-up was 66 months. After chemoradiation therapy (CRT), 13 pts (34%) had a complete response, 23 pts (60%) a response >50% (2 pts were not evaluated). The 5-year-disease-free survival was 79.2 ± 6.5%, and the 5-year overall survival was 83.9 ± 6%. Eight patients developed tumor progression (mean delay 8.8 months), six of them requiring a salvage surgery with definitive colostomy for local relapse. Late severe complication requiring colostomy was observed in 2 pts. The 5-year-colostomy-free survival was 78 ± 6.9%. Patients who received primary chemotherapy had a statistically significant better 5-year colostomy-free survival (100% vs. 38 ± 16.4%, P = 0.0006). T4 anal carcinoma can be treated with a curative intent using a sphincter-sparing approach of CRT, and neo-adjuvant chemotherapy should be considered prior to radiotherapy. Copyright © 2011 Wiley-Liss, Inc.

  10. Neutrino mass priors for cosmology from random matrices

    Science.gov (United States)

    Long, Andrew J.; Raveri, Marco; Hu, Wayne; Dodelson, Scott

    2018-02-01

    Cosmological measurements of structure are placing increasingly strong constraints on the sum of the neutrino masses, Σ mν, through Bayesian inference. Because these constraints depend on the choice for the prior probability π (Σ mν), we argue that this prior should be motivated by fundamental physical principles rather than the ad hoc choices that are common in the literature. The first step in this direction is to specify the prior directly at the level of the neutrino mass matrix Mν, since this is the parameter appearing in the Lagrangian of the particle physics theory. Thus by specifying a probability distribution over Mν, and by including the known squared mass splittings, we predict a theoretical probability distribution over Σ mν that we interpret as a Bayesian prior probability π (Σ mν). Assuming a basis-invariant probability distribution on Mν, also known as the anarchy hypothesis, we find that π (Σ mν) peaks close to the smallest Σ mν allowed by the measured mass splittings, roughly 0.06 eV (0.1 eV) for normal (inverted) ordering, due to the phenomenon of eigenvalue repulsion in random matrices. We consider three models for neutrino mass generation: Dirac, Majorana, and Majorana via the seesaw mechanism; differences in the predicted priors π (Σ mν) allow for the possibility of having indications about the physical origin of neutrino masses once sufficient experimental sensitivity is achieved. We present fitting functions for π (Σ mν), which provide a simple means for applying these priors to cosmological constraints on the neutrino masses or marginalizing over their impact on other cosmological parameters.

  11. Estimating security betas using prior information based on firm fundamentals

    NARCIS (Netherlands)

    Cosemans, M.; Frehen, R.; Schotman, P.C.; Bauer, R.

    2010-01-01

    This paper proposes a novel approach for estimating time-varying betas of individual stocks that incorporates prior information based on fundamentals. We shrink the rolling window estimate of beta towards a firm-specific prior that is motivated by asset pricing theory. The prior captures structural

  12. Stenting Prior to Cystectomy is an Independent Risk Factor for Upper Urinary Tract Recurrence.

    Science.gov (United States)

    Kiss, Bernhard; Furrer, Marc A; Wuethrich, Patrick Y; Burkhard, Fiona C; Thalmann, George N; Roth, Beat

    2017-12-01

    Patients with bladder cancer who present with hydronephrosis may require drainage of the affected kidney before receiving further cancer treatment. Drainage can be done by retrograde stenting or percutaneously. However, retrograde stenting carries the risk of tumor cell spillage to the upper urinary tract. The aim of this study was to evaluate whether patients with bladder cancer are at higher risk for upper urinary tract recurrence if retrograde stenting has been performed prior to radical cystectomy. We retrospectively analyzed the records of 1,005 consecutive patients with bladder cancer who underwent radical cystectomy at our department between January 2000 and June 2016. Negative intraoperative ureteral margins were mandatory for study inclusion. Patients received regular followup according to our institutional protocol, including imaging of the upper urinary tract and urine cytology. Preoperative drainage of the upper urinary tract was performed in 114 of the 1,005 patients (11%), including in 53 (46%) by Double-J® stenting and in 61 (54%) by percutaneous nephrostomy. Recurrence developed in the upper urinary tract in 31 patients (3%) at a median of 17 months after cystectomy, including 7 of 53 (13%) in the Double-J group, 0% in the nephrostomy group and 24 of 891 (3%) in the no drainage group. Multivariate regression analysis revealed a higher risk of upper urinary tract recurrence if patients underwent Double-J stenting (HR 4.54, 95% CI 1.43-14.38, p = 0.01) and preoperative intravesical instillations (HR 2.94, 95% CI 1.40-6.16, p = 0.004). Patients who undergo Double-J stenting prior to radical cystectomy are at higher risk for upper urinary tract recurrence. If preoperative upper urinary tract drainage is required, percutaneous drainage might be recommended. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  13. Waste Receiving and Processing Facility, Module 1: Volume 5, Engineering studies

    International Nuclear Information System (INIS)

    1992-03-01

    The WRAP facility at Hanford will retrieve, process, certify transuranic, mixed, and low level radioactive wastes for disposal/either on-site or at the WIPP. The Conceptual Design Report for the Waste Receiving And Processing Facility, Module 1 (WRAP 1), established the technical benchmark. The UE ampersand C Engineering Proposal/Work Plan proposed twenty Evaluation/Optimization Engineering Studies to evaluate design alternatives and critically examine functional performance requirements prior to commencement of Preliminary Design. Of these twenty studies, one has been eliminated as unnecessary (The Use of Scintered Metal Filters) due mainly to the lack of National Standards and to the fact that standard HEPA type filters are totally adequate for WRAP application. This report presents an executive summary of the remaining nineteen studies

  14. 34 CFR 303.403 - Prior notice; native language.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Prior notice; native language. 303.403 Section 303.403... TODDLERS WITH DISABILITIES Procedural Safeguards General § 303.403 Prior notice; native language. (a... file a complaint and the timelines under those procedures. (c) Native language. (1) The notice must be...

  15. Intra-articular steroid injection for osteoarthritis of the hip prior to total hip arthroplasty : is it safe? a systematic review.

    Science.gov (United States)

    Pereira, L C; Kerr, J; Jolles, B M

    2016-08-01

    Using a systematic review, we investigated whether there is an increased risk of post-operative infection in patients who have received an intra-articular corticosteroid injection to the hip for osteoarthritis prior to total hip arthroplasty (THA). Studies dealing with an intra-articular corticosteroid injection to the hip and infection following subsequent THA were identified from databases for the period between 1990 to 2013. Retrieved articles were independently assessed for their methodological quality. A total of nine studies met the inclusion criteria. Two recommended against a steroid injection prior to THA and seven found no risk with an injection. No prospective controlled trials were identified. Most studies were retrospective. Lack of information about the methodology was a consistent flaw. The literature in this area is scarce and the evidence is weak. Most studies were retrospective, and confounding factors were poorly defined or not addressed. There is thus currently insufficient evidence to conclude that an intra-articular corticosteroid injection administered prior to THA increases the rate of infection. High quality, multicentre randomised trials are needed to address this issue. Cite this article: Bone Joint J 2016;98-B:1027-35. ©2016 The British Editorial Society of Bone & Joint Surgery.

  16. Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

    International Nuclear Information System (INIS)

    Giantsoudi, Drosoula; Seco, Joao; Eaton, Bree R.; Simeone, F. Joseph; Kooy, Hanne; Yock, Torunn I.; Tarbell, Nancy J.; DeLaney, Thomas F.; Adams, Judith; Paganetti, Harald; MacDonald, Shannon M.

    2017-01-01

    Purpose: At present, proton craniospinal irradiation (CSI) for growing children is delivered to the whole vertebral body (WVB) to avoid asymmetric growth. We aimed to demonstrate the feasibility and potential clinical benefit of delivering vertebral body sparing (VBS) versus WVB CSI with passively scattered (PS) and intensity modulated proton therapy (IMPT) in growing children treated for medulloblastoma. Methods and Materials: Five plans were generated for medulloblastoma patients, who had been previously treated with CSI PS proton radiation therapy: (1) single posteroanterior (PA) PS field covering the WVB (PS-PA-WVB); (2) single PA PS field that included only the thecal sac in the target volume (PS-PA-VBS); (3) single PA IMPT field covering the WVB (IMPT-PA-WVB); (4) single PA IMPT field, target volume including thecal sac only (IMPT-PA-VBS); and (5) 2 posterior-oblique (−35°, +35°) IMPT fields, with the target volume including the thecal sac only (IMPT2F-VBS). For all cases, 23.4 Gy (relative biologic effectiveness [RBE]) was prescribed to 95% of the spinal canal. The dose, linear energy transfer, and variable-RBE-weighted dose distributions were calculated for all plans using the tool for particle simulation, version 2, Monte Carlo system. Results: IMPT VBS techniques efficiently spared the anterior vertebral bodies (AVBs), even when accounting for potential higher variable RBE predicted by linear energy transfer distributions. Assuming an RBE of 1.1, the V10 Gy(RBE) decreased from 100% for the WVB techniques to 59.5% to 76.8% for the cervical, 29.9% to 34.6% for the thoracic, and 20.6% to 25.1% for the lumbar AVBs, and the V20 Gy(RBE) decreased from 99.0% to 17.8% to 20.0% for the cervical, 7.2% to 7.6% for the thoracic, and 4.0% to 4.6% for the lumbar AVBs when IMPT VBS techniques were applied. The corresponding percentages for the PS VBS technique were higher. Conclusions: Advanced proton techniques can sufficiently reduce the dose to the vertebral

  17. Evaluating Intensity Modulated Proton Therapy Relative to Passive Scattering Proton Therapy for Increased Vertebral Column Sparing in Craniospinal Irradiation in Growing Pediatric Patients

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, Drosoula, E-mail: dgiantsoudi@mgh.harvard.edu; Seco, Joao; Eaton, Bree R.; Simeone, F. Joseph; Kooy, Hanne; Yock, Torunn I.; Tarbell, Nancy J.; DeLaney, Thomas F.; Adams, Judith; Paganetti, Harald; MacDonald, Shannon M.

    2017-05-01

    Purpose: At present, proton craniospinal irradiation (CSI) for growing children is delivered to the whole vertebral body (WVB) to avoid asymmetric growth. We aimed to demonstrate the feasibility and potential clinical benefit of delivering vertebral body sparing (VBS) versus WVB CSI with passively scattered (PS) and intensity modulated proton therapy (IMPT) in growing children treated for medulloblastoma. Methods and Materials: Five plans were generated for medulloblastoma patients, who had been previously treated with CSI PS proton radiation therapy: (1) single posteroanterior (PA) PS field covering the WVB (PS-PA-WVB); (2) single PA PS field that included only the thecal sac in the target volume (PS-PA-VBS); (3) single PA IMPT field covering the WVB (IMPT-PA-WVB); (4) single PA IMPT field, target volume including thecal sac only (IMPT-PA-VBS); and (5) 2 posterior-oblique (−35°, +35°) IMPT fields, with the target volume including the thecal sac only (IMPT2F-VBS). For all cases, 23.4 Gy (relative biologic effectiveness [RBE]) was prescribed to 95% of the spinal canal. The dose, linear energy transfer, and variable-RBE-weighted dose distributions were calculated for all plans using the tool for particle simulation, version 2, Monte Carlo system. Results: IMPT VBS techniques efficiently spared the anterior vertebral bodies (AVBs), even when accounting for potential higher variable RBE predicted by linear energy transfer distributions. Assuming an RBE of 1.1, the V10 Gy(RBE) decreased from 100% for the WVB techniques to 59.5% to 76.8% for the cervical, 29.9% to 34.6% for the thoracic, and 20.6% to 25.1% for the lumbar AVBs, and the V20 Gy(RBE) decreased from 99.0% to 17.8% to 20.0% for the cervical, 7.2% to 7.6% for the thoracic, and 4.0% to 4.6% for the lumbar AVBs when IMPT VBS techniques were applied. The corresponding percentages for the PS VBS technique were higher. Conclusions: Advanced proton techniques can sufficiently reduce the dose to the vertebral

  18. Highly Conformal Craniospinal Radiotherapy Techniques Can Underdose the Cranial Clinical Target Volume if Leptomeningeal Extension through Skull Base Exit Foramina is not Contoured.

    Science.gov (United States)

    Noble, D J; Ajithkumar, T; Lambert, J; Gleeson, I; Williams, M V; Jefferies, S J

    2017-07-01

    Craniospinal irradiation (CSI) remains a crucial treatment for patients with medulloblastoma. There is uncertainty about how to manage meningeal surfaces and cerebrospinal fluid (CSF) that follows cranial nerves exiting skull base foramina. The purpose of this study was to assess plan quality and dose coverage of posterior cranial fossa foramina with both photon and proton therapy. We analysed the radiotherapy plans of seven patients treated with CSI for medulloblastoma and primitive neuro-ectodermal tumours and three with ependymoma (total n = 10). Four had been treated with a field-based technique and six with TomoTherapy™. The internal acoustic meatus (IAM), jugular foramen (JF) and hypoglossal canal (HC) were contoured and added to the original treatment clinical target volume (Plan_CTV) to create a Test_CTV. This was grown to a test planning target volume (Test_PTV) for comparison with a Plan_PTV. Using Plan_CTV and Plan_PTV, proton plans were generated for all 10 cases. The following dosimetry data were recorded: conformity (dice similarity coefficient) and homogeneity index (D 2  - D 98 /D 50 ) as well as median and maximum dose (D 2% ) to Plan_PTV, V 95% and minimum dose (D 99.9% ) to Plan_CTV and Test_CTV and Plan_PTV and Test_PTV, V 95% and minimum dose (D 98% ) to foramina PTVs. Proton and TomoTherapy™ plans were more conformal (0.87, 0.86) and homogeneous (0.07, 0.04) than field-photon plans (0.79, 0.17). However, field-photon plans covered the IAM, JF and HC PTVs better than proton plans (P = 0.002, 0.004, 0.003, respectively). TomoTherapy™ plans covered the IAM and JF better than proton plans (P = 0.000, 0.002, respectively) but the result for the HC was not significant. Adding foramen CTVs/PTVs made no difference for field plans. The mean D min dropped 3.4% from Plan_PTV to Test_PTV for TomoTherapy™ (not significant) and 14.8% for protons (P = 0.001). Highly conformal CSI techniques may underdose meninges and CSF in the dural

  19. Highly Sensitive Optical Receivers

    CERN Document Server

    Schneider, Kerstin

    2006-01-01

    Highly Sensitive Optical Receivers primarily treats the circuit design of optical receivers with external photodiodes. Continuous-mode and burst-mode receivers are compared. The monograph first summarizes the basics of III/V photodetectors, transistor and noise models, bit-error rate, sensitivity and analog circuit design, thus enabling readers to understand the circuits described in the main part of the book. In order to cover the topic comprehensively, detailed descriptions of receivers for optical data communication in general and, in particular, optical burst-mode receivers in deep-sub-µm CMOS are presented. Numerous detailed and elaborate illustrations facilitate better understanding.

  20. Receiver Test Selection Criteria

    Science.gov (United States)

    2015-03-12

    The DOT requests that GPS manufacturers submit receivers for test in the following TWG categories: - Aviation (non-certified), cellular, general location/navigation, high precision, timing, networks, and space-based receivers - Each receiver should b...

  1. Diabetes patients requiring glucose-lowering therapy and nondiabetics with a prior myocardial infarction carry the same cardiovascular risk: a population study of 3.3 million people

    DEFF Research Database (Denmark)

    Schramm, Tina Ken; Gislason, Gunnar H; Køber, Lars

    2008-01-01

    BACKGROUND: Previous studies reveal major differences in the estimated cardiovascular risk in diabetes mellitus, including uncertainty about the risk in young patients. Therefore, large studies of well-defined populations are needed. METHODS AND RESULTS: All residents in Denmark > or = 30 years...... of age were followed up for 5 years (1997 to 2002) by individual-level linkage of nationwide registers. Diabetes patients receiving glucose-lowering medications and nondiabetics with and without a prior myocardial infarction were compared. At baseline, 71 801 (2.2%) had diabetes mellitus and 79 575 (2.......4%) had a prior myocardial infarction. Regardless of age, age-adjusted Cox proportional-hazard ratios for cardiovascular death were 2.42 (95% confidence interval [CI], 2.35 to 2.49) in men with diabetes mellitus without a prior myocardial infarction and 2.44 (95% CI, 2.39 to 2.49) in nondiabetic men...

  2. Tandem high-dose chemotherapy and auto-SCT for malignant brain tumors in children under 3 years of age.

    Science.gov (United States)

    Sung, K W; Lim, D H; Lee, S H; Yoo, K H; Koo, H H; Kim, J H; Suh, Y-L; Joung, Y S; Shin, H J

    2013-07-01

    In an effort to improve survival and reduce late adverse effects of radiation therapy (RT), 25 children SCT following six cycles of induction chemotherapy. RT was either not given or deferred until 3 years of age if the patient was in CR after tandem HDCT/auto-SCT. Tumors relapsed or progressed in nine patients (five during induction treatment), and two of these patients survived after receiving salvage treatment, including RT. Two patients died due to toxicities during tandem HDCT/auto-SCT. A total of 16 patients survived to a median follow-up period of 52 months (range 18-96) from the time of diagnosis. Four of these patients did not receive RT, two received local RT (L-RT), three received craniospinal RT (CSRT), and seven received both L-RT and CSRT. The 5-year OS and EFS rates were 67.8±9.4% and 55.5±10.0%, respectively. Neuroendocrine and neurocognitive functions evaluated 3 years after tandem HDCT/auto-SCT were acceptable. Our results indicate that tandem HDCT/auto-SCT may improve survival in young children with malignant brain tumors with an acceptable level of risk of long-term toxicity.

  3. 30 CFR 872.29 - What are prior balance replacement funds?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false What are prior balance replacement funds? 872... § 872.29 What are prior balance replacement funds? “Prior balance replacement funds” are moneys we must... general funds of the United States Treasury that are otherwise unappropriated. Under section 411(h)(1) of...

  4. Radiation-induced osteochondroma of the T4 vertebra causing spinal cord compression

    Energy Technology Data Exchange (ETDEWEB)

    Gorospe, Luis; Madrid-Muniz, Carmen; Royo, Aranzazu; Garcia-Raya, Pilar [Department of Radiology, La Paz University Hospital, Madrid (Spain); Alvarez-Ruiz, Fernando [Department of Neurosurgery, La Paz University Hospital, Madrid (Spain); Lopez-Barea, Fernando [Department of Pathology, La Paz University Hospital, Madrid (Spain)

    2002-04-01

    A case of a radiation-induced osteochondroma arising from the vertebral body of T4 in an 18-year-old man is reported. The patient presented with a history of progressive left lower extremity weakness. At 7 years of age, he had undergone resection of a cerebellar medulloblastoma and received adjunctive craniospinal irradiation and systemic chemotherapy. Both CT and MR imaging revealed an extradural mass contiguous with the posteroinferior endplate of the T4 vertebral body. This case indicates that radiation-induced osteochondroma should be considered in the differential diagnosis of patients with symptoms of myelopathy or nerve root compression and a history of radiation therapy involving the spine in childhood. (orig.)

  5. Prior opportunities to identify abuse in children with abusive head trauma.

    Science.gov (United States)

    Letson, Megan M; Cooper, Jennifer N; Deans, Katherine J; Scribano, Philip V; Makoroff, Kathi L; Feldman, Kenneth W; Berger, Rachel P

    2016-10-01

    Infants with minor abusive injuries are at risk for more serious abusive injury, including abusive head trauma (AHT). Our study objective was to determine if children with AHT had prior opportunities to detect abuse and to describe the opportunities. All AHT cases from 7/1/2009 to 12/31/2011 at four tertiary care children's hospitals were included. A prior opportunity was defined as prior evaluation by either a medical or child protective services (CPS) professional when the symptoms and/or referral could be consistent with abuse but the diagnosis was not made and/or an alternate explanation was given and accepted. Two-hundred-thirty-two children with AHT were identified; median age (IQR) was 5.40 (3.30, 14.60) months. Ten percent (22/232) died. Of the 232 patients diagnosed with AHT, 31% (n=73) had a total of 120 prior opportunities. Fifty-nine children (25%) had at least one prior opportunity to identify abuse in a medical setting, representing 98 prior opportunities. An additional 14 (6%) children had 22 prior opportunities through previous CPS involvement. There were no differences between those with and without a prior opportunity based on age, gender, race, insurance, mortality, or institution. Children with prior opportunities in a medical setting were more likely to have chronic subdural hemorrhage (48 vs. 17%, p<0.01) and healing fractures (31 vs. 19%, p=0.05). The most common prior opportunities included vomiting 31.6% (38/120), prior CPS contact 20% (24/120), and bruising 11.7% (14/120). Improvements in earlier recognition of AHT and subsequent intervention might prevent additional injuries and reduce mortality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Variational segmentation problems using prior knowledge in imaging and vision

    DEFF Research Database (Denmark)

    Fundana, Ketut

    This dissertation addresses variational formulation of segmentation problems using prior knowledge. Variational models are among the most successful approaches for solving many Computer Vision and Image Processing problems. The models aim at finding the solution to a given energy functional defined......, prior knowledge is needed to obtain the desired solution. The introduction of shape priors in particular, has proven to be an effective way to segment objects of interests. Firstly, we propose a prior-based variational segmentation model to segment objects of interest in image sequences, that can deal....... Many objects have high variability in shape and orientation. This often leads to unsatisfactory results, when using a segmentation model with single shape template. One way to solve this is by using more sophisticated shape models. We propose to incorporate shape priors from a shape sub...

  7. Prior and present evidence: how prior experience interacts with present information in a perceptual decision making task.

    Directory of Open Access Journals (Sweden)

    Muhsin Karim

    Full Text Available Vibrotactile discrimination tasks have been used to examine decision making processes in the presence of perceptual uncertainty, induced by barely discernible frequency differences between paired stimuli or by the presence of embedded noise. One lesser known property of such tasks is that decisions made on a single trial may be biased by information from prior trials. An example is the time-order effect whereby the presentation order of paired stimuli may introduce differences in accuracy. Subjects perform better when the first stimulus lies between the second stimulus and the global mean of all stimuli on the judged dimension ("preferred" time-orders compared to the alternative presentation order ("nonpreferred" time-orders. This has been conceptualised as a "drift" of the first stimulus representation towards the global mean of the stimulus-set (an internal standard. We describe the influence of prior information in relation to the more traditionally studied factors of interest in a classic discrimination task.Sixty subjects performed a vibrotactile discrimination task with different levels of uncertainty parametrically induced by increasing task difficulty, aperiodic stimulus noise, and changing the task instructions whilst maintaining identical stimulus properties (the "context".The time-order effect had a greater influence on task performance than two of the explicit factors-task difficulty and noise-but not context. The influence of prior information increased with the distance of the first stimulus from the global mean, suggesting that the "drift" velocity of the first stimulus towards the global mean representation was greater for these trials.Awareness of the time-order effect and prior information in general is essential when studying perceptual decision making tasks. Implicit mechanisms may have a greater influence than the explicit factors under study. It also affords valuable insights into basic mechanisms of information

  8. The Prior Can Often Only Be Understood in the Context of the Likelihood

    Directory of Open Access Journals (Sweden)

    Andrew Gelman

    2017-10-01

    Full Text Available A key sticking point of Bayesian analysis is the choice of prior distribution, and there is a vast literature on potential defaults including uniform priors, Jeffreys’ priors, reference priors, maximum entropy priors, and weakly informative priors. These methods, however, often manifest a key conceptual tension in prior modeling: a model encoding true prior information should be chosen without reference to the model of the measurement process, but almost all common prior modeling techniques are implicitly motivated by a reference likelihood. In this paper we resolve this apparent paradox by placing the choice of prior into the context of the entire Bayesian analysis, from inference to prediction to model evaluation.

  9. Quantum steganography using prior entanglement

    International Nuclear Information System (INIS)

    Mihara, Takashi

    2015-01-01

    Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography

  10. Quantum steganography using prior entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, Takashi, E-mail: mihara@toyo.jp

    2015-06-05

    Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography.

  11. Crowdsourcing prior information to improve study design and data analysis.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Chrabaszcz

    Full Text Available Though Bayesian methods are being used more frequently, many still struggle with the best method for setting priors with novel measures or task environments. We propose a method for setting priors by eliciting continuous probability distributions from naive participants. This allows us to include any relevant information participants have for a given effect. Even when prior means are near-zero, this method provides a principle way to estimate dispersion and produce shrinkage, reducing the occurrence of overestimated effect sizes. We demonstrate this method with a number of published studies and compare the effect of different prior estimation and aggregation methods.

  12. Formulating informative, data-based priors for failure probability estimation in reliability analysis

    International Nuclear Information System (INIS)

    Guikema, Seth D.

    2007-01-01

    Priors play an important role in the use of Bayesian methods in risk analysis, and using all available information to formulate an informative prior can lead to more accurate posterior inferences. This paper examines the practical implications of using five different methods for formulating an informative prior for a failure probability based on past data. These methods are the method of moments, maximum likelihood (ML) estimation, maximum entropy estimation, starting from a non-informative 'pre-prior', and fitting a prior based on confidence/credible interval matching. The priors resulting from the use of these different methods are compared qualitatively, and the posteriors are compared quantitatively based on a number of different scenarios of observed data used to update the priors. The results show that the amount of information assumed in the prior makes a critical difference in the accuracy of the posterior inferences. For situations in which the data used to formulate the informative prior is an accurate reflection of the data that is later observed, the ML approach yields the minimum variance posterior. However, the maximum entropy approach is more robust to differences between the data used to formulate the prior and the observed data because it maximizes the uncertainty in the prior subject to the constraints imposed by the past data

  13. Finding A Minimally Informative Dirichlet Prior Using Least Squares

    International Nuclear Information System (INIS)

    Kelly, Dana

    2011-01-01

    In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straightforward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson λ, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in the form of a standard distribution (e.g., beta, gamma), and so a beta distribution is used as an approximation in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial model for common-cause failure, must be estimated from data that are often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.

  14. A Noninformative Prior on a Space of Distribution Functions

    Directory of Open Access Journals (Sweden)

    Alexander Terenin

    2017-07-01

    Full Text Available In a given problem, the Bayesian statistical paradigm requires the specification of a prior distribution that quantifies relevant information about the unknowns of main interest external to the data. In cases where little such information is available, the problem under study may possess an invariance under a transformation group that encodes a lack of information, leading to a unique prior—this idea was explored at length by E.T. Jaynes. Previous successful examples have included location-scale invariance under linear transformation, multiplicative invariance of the rate at which events in a counting process are observed, and the derivation of the Haldane prior for a Bernoulli success probability. In this paper we show that this method can be extended, by generalizing Jaynes, in two ways: (1 to yield families of approximately invariant priors; and (2 to the infinite-dimensional setting, yielding families of priors on spaces of distribution functions. Our results can be used to describe conditions under which a particular Dirichlet Process posterior arises from an optimal Bayesian analysis, in the sense that invariances in the prior and likelihood lead to one and only one posterior distribution.

  15. Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations

    Science.gov (United States)

    Mantz, A.; Allen, S. W.

    2011-01-01

    Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this information takes the form of particular parametrized functions used to describe the cluster gas density and temperature profiles. In this paper, we investigate the implicit priors on hydrostatic masses that result from this fully parametric approach, and the implications of such priors for scaling relations formed from those masses. We show that the application of such fully parametric models of the ICM naturally imposes a prior on the slopes of the derived scaling relations, favoring the self-similar model, and argue that this prior may be influential in practice. In contrast, this bias does not exist for techniques which adopt an explicit prior on the form of the mass profile but describe the ICM non-parametrically. Constraints on the slope of the cluster mass-temperature relation in the literature show a separation based the approach employed, with the results from fully parametric ICM modeling clustering nearer the self-similar value. Given that a primary goal of scaling relation analyses is to test the self-similar model, the application of methods subject to strong, implicit priors should be avoided. Alternative methods and best practices are discussed.

  16. The Clinical Impact of Cardiology Consultation Prior to Major Vascular Surgery.

    Science.gov (United States)

    Davis, Frank M; Park, Yeo June; Grey, Scott F; Boniakowski, Anna E; Mansour, M Ashraf; Jain, Krishna M; Nypaver, Timothy; Grossman, Michael; Gurm, Hitinder; Henke, Peter K

    2018-01-01

    To understand statewide variation in preoperative cardiology consultation prior to major vascular surgery and to determine whether consultation was associated with differences in perioperative myocardial infarction (poMI). Medical consultation prior to major vascular surgery is obtained to reduce perioperative risk. Despite perceived benefit of preoperative consultation, evidence is lacking specifically for major vascular surgery on the effect of preoperative cardiac consultation. Patient and clinical data were obtained from a statewide vascular surgery registry between January 2012 and December 2014. Patients were risk stratified by revised cardiac risk index category and compared poMI between patients who did or did not receive a preoperative cardiology consultation. We then used logistic regression analysis to compare the rate of poMI across hospitals grouped into quartiles by rate of preoperative cardiology consultation. Our study population comprised 5191 patients undergoing open peripheral arterial bypass (n = 3037), open abdominal aortic aneurysm repair (n = 332), or endovascular aneurysm repair (n = 1822) at 29 hospitals. At the patient level, after risk-stratification by revised cardiac risk index category, there was no association between cardiac consultation and poMI. At the hospital level, preoperative cardiac consultation varied substantially between hospitals (6.9%-87.5%, P 66%) had a reduction in poMI (OR, 0.52; confidence interval: 0.28-0.98; P cardiology consultation for vascular surgery varies greatly between institutions, and does not appear to impact poMI at the patient level. However, reduction of poMI was noted at the hospitals with the highest rate of preoperative cardiology consultation as well as a variety of medical services, suggesting that other hospital culture effects play a role.

  17. Superposing pure quantum states with partial prior information

    Science.gov (United States)

    Dogra, Shruti; Thomas, George; Ghosh, Sibasish; Suter, Dieter

    2018-05-01

    The principle of superposition is an intriguing feature of quantum mechanics, which is regularly exploited in many different circumstances. A recent work [M. Oszmaniec et al., Phys. Rev. Lett. 116, 110403 (2016), 10.1103/PhysRevLett.116.110403] shows that the fundamentals of quantum mechanics restrict the process of superimposing two unknown pure states, even though it is possible to superimpose two quantum states with partial prior knowledge. The prior knowledge imposes geometrical constraints on the choice of input states. We discuss an experimentally feasible protocol to superimpose multiple pure states of a d -dimensional quantum system and carry out an explicit experimental realization for two single-qubit pure states with partial prior information on a two-qubit NMR quantum information processor.

  18. On the prior probabilities for two-stage Bayesian estimates

    International Nuclear Information System (INIS)

    Kohut, P.

    1992-01-01

    The method of Bayesian inference is reexamined for its applicability and for the required underlying assumptions in obtaining and using prior probability estimates. Two different approaches are suggested to determine the first-stage priors in the two-stage Bayesian analysis which avoid certain assumptions required for other techniques. In the first scheme, the prior is obtained through a true frequency based distribution generated at selected intervals utilizing actual sampling of the failure rate distributions. The population variability distribution is generated as the weighed average of the frequency distributions. The second method is based on a non-parametric Bayesian approach using the Maximum Entropy Principle. Specific features such as integral properties or selected parameters of prior distributions may be obtained with minimal assumptions. It is indicated how various quantiles may also be generated with a least square technique

  19. Form of prior for constrained thermodynamic processes with uncertainty

    Science.gov (United States)

    Aneja, Preety; Johal, Ramandeep S.

    2015-05-01

    We consider the quasi-static thermodynamic processes with constraints, but with additional uncertainty about the control parameters. Motivated by inductive reasoning, we assign prior distribution that provides a rational guess about likely values of the uncertain parameters. The priors are derived explicitly for both the entropy-conserving and the energy-conserving processes. The proposed form is useful when the constraint equation cannot be treated analytically. The inference is performed using spin-1/2 systems as models for heat reservoirs. Analytical results are derived in the high-temperatures limit. An agreement beyond linear response is found between the estimates of thermal quantities and their optimal values obtained from extremum principles. We also seek an intuitive interpretation for the prior and the estimated value of temperature obtained therefrom. We find that the prior over temperature becomes uniform over the quantity kept conserved in the process.

  20. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    International Nuclear Information System (INIS)

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-01-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p ≤ 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  1. Progressive ototoxicity after combined modality treatment of medulloblastoma

    International Nuclear Information System (INIS)

    Dutton, S.C.; Neault, M.; Billett, A.E.; LaVally, B.; Scott, R.M.; Sallan, S.E.; Tarbell, N.J.

    1996-01-01

    Objective: Prospective study to evaluate the response rate, survival and toxicity of pre-irradiation chemotherapy in the treatment of children with seeding CNS tumors. Materials and Methods: Forty-two patients with medulloblastoma were enrolled on a prospective pre-irradiation chemotherapy protocol between 1984 and 1990. Patients (Median age 9.5 years; 29 males, 13 females) received post-operative chemotherapy [cisplatinum 100 mg/m2 q 3 weeks) and vincristine (1.5 mg/m2 weekly) for 9 weeks. Infants (4 patients) received nitrogen mustard (6 mg/m2), procarbazine (100 mg/m2) and vincristine (1.5 mg/m2) until age two followed by craniospinal radiation (CSI). Forty-one patients received CSI with ≥ 50 Gy to the posterior fossa (PF). The median doses to the whole brain, PF, and spine were 33.8 Gy, 55.3 Gy, 27.8 Gy, respectively. Results: Five-year overall survival was 86% and event-free survival was 65% (median follow-up for survivors, 61 months). Thirteen of 15 patients with complete surgical resection documented by post-operative imaging remained free of disease during chemotherapy (CT), and were considered unevaluable for response to CT. The response rate (complete plus partial) to pre-irradiation CT was 45% ((13(29))). Ten patients had stable disease and 6 had progressive disease (PD). Three of 6 patients with PD were long-term survivors after CSI. Thirteen patients relapsed with a median time to failure of 14.5 months. Sites of failure were PF (5 pts), spinal cord (3 pts), CNS/meninges (3 pts), PF/spinal cord (1 pt), and bone metastasis (1 pt). Ototoxicity analysis was performed using 24 patients who had normal hearing in the better ear before chemotherapy and at least one follow-up audiogram for comparison after therapy. 17 patients had an audiogram immediately after CT, and 71% of pts ((12(17))) had high frequency hearing impairment beginning in 3000-8000 Hz range. 18% ((3(17))) had hearing loss in the 500-2000 Hz range necessitating a hearing aid post-CT. 22

  2. Inverse problems with non-trivial priors: efficient solution through sequential Gibbs sampling

    DEFF Research Database (Denmark)

    Hansen, Thomas Mejer; Cordua, Knud Skou; Mosegaard, Klaus

    2012-01-01

    Markov chain Monte Carlo methods such as the Gibbs sampler and the Metropolis algorithm can be used to sample solutions to non-linear inverse problems. In principle, these methods allow incorporation of prior information of arbitrary complexity. If an analytical closed form description of the prior...... is available, which is the case when the prior can be described by a multidimensional Gaussian distribution, such prior information can easily be considered. In reality, prior information is often more complex than can be described by the Gaussian model, and no closed form expression of the prior can be given....... We propose an algorithm, called sequential Gibbs sampling, allowing the Metropolis algorithm to efficiently incorporate complex priors into the solution of an inverse problem, also for the case where no closed form description of the prior exists. First, we lay out the theoretical background...

  3. SUSPENSION OF THE PRIOR DISCIPLINARY INVESTIGATION ACCORDING TO LABOR LAW

    Directory of Open Access Journals (Sweden)

    Nicolae, GRADINARU

    2014-11-01

    Full Text Available In order to conduct the prior disciplinary investigation, the employee shall be convoked in writing by the person authorized by the employer to carry out the research, specifying the subject, date, time and place of the meeting. For this purpose the employer shall appoint a committee charged with conducting the prior disciplinary investigation. Prior disciplinary research cannot be done without the possibility of the accused person to defend himself. It would be an abuse of the employer to violate these provisions. Since the employee is entitled to formulate and sustain defence in proving innocence or lesser degree of guilt than imputed, it needs between the moment were disclosed to the employee and the one of performing the prior disciplinary investigation to be a reasonable term for the employee to be able to prepare a defence in this regard. The employee's failure to present at the convocation, without an objective reason entitles the employer to dispose the sanctioning without making the prior disciplinary investigation. The objective reason which makes the employee, that is subject to prior disciplinary investigation, unable to present to the preliminary disciplinary investigation, should be at the time of the investigation in question.

  4. Available online Efficiency potential of indirectly heated solar reforming with different types of solar air receivers

    International Nuclear Information System (INIS)

    Storch, Henrik von; Roeb, Martin; Stadler, Hannes; Sattler, Christian; Hoffschmidt, Bernhard

    2016-01-01

    Highlights: • A process for indirectly heated solar reforming of natural gas with air as heat transfer fluid is proposed. • Different solar receivers are modeled and implemented into the reforming process. • The overall efficiency of the process with different solar receivers is determined. • Optimum solar receiver characteristics for application in a solar reforming process are determined. - Abstract: In solar reforming, the heating value of natural gas is increased by utilization of concentrated solar radiation. Hence, it is a process for storing solar energy in a stable and transportable form that also permits further conversion into liquid fuels like methanol. This process has the potential to significantly decrease the natural gas consumption and the associated CO_2-emissions of methanol production with only few open questions to be addressed prior to commercialization. In the medium and long term, it has the potential to generate methanol as an environmentally friendly fuel for both transport as well as flexible electricity production in combined cycle gas turbines, when biogas is used as reactant. In a previous study the high potential of indirectly heated solar reforming with solar air receivers was shown; however, the efficiency is limited when using state of the art open volumetric receivers. Therefore, different types of air receivers are implemented into an indirectly heated solar reforming process and the overall efficiency potential is assessed in the present study. The implemented receivers are an open volumetric cavity receiver, a closed volumetric cavity receiver and a tubular cavity receiver. The open volumetric cavity receiver and tubular cavity receiver achieve the best results due to their capability of operating efficiently at temperatures well above 700 °C. For these receivers peak efficiencies up to 29% and 27% respectively are predicted. As the utilization of an open volumetric cavity receiver constitutes an open heat transfer

  5. Anxiety, depression in patients receiving chemotherapy for solid tumors

    International Nuclear Information System (INIS)

    Mansoor, S.; Jehangir, S.

    2015-01-01

    To determine the frequency of anxiety and depression in patients undergoing chemotherapy for solid tumors using Hospital Anxiety Depression Scale (HADS). Study Design: Cross sectional descriptive study. Place and Duration of Study: Out-patient department of Armed Forces Institute of Mental Health, Rawalpindi from June 2011 to December 2011. Methodology: Consecutive non probability sampling technique was used to select patients of age (25-70 years), male or female, who had received atleast 03 cycles of chemotherapy for solid tumors. Those with history of prior psychiatric illness, current use of psychotropic medication or psychoactive substance use, and any major bereavement in past one year were excluded from the study. After taking informed consent, relevant socio- demographic data was collected and HADS was administered. HADS-A cut off score of 7 was taken as significant anxiety while a HADS-D cut off score of 7 was taken as significant depression. Results: The total number of participants was 209. The mean age of patients was 42.9 years, with 55.5% males and 44.5% females. Overall 33/209 (15.8%) patients had anxiety while 56/209 (26.8%) were found to have depression. There was a higher frequency of anxiety and depression in younger patients (less than age 40 years), females, patients who were single or divorced, and patients receiving chemotherapy for pancreatic carcinoma. Conclusion: Patients undergoing chemotherapy suffer from considerable levels of anxiety and depression, thus highlighting the need for specialized interventions. (author)

  6. Adaptive estimation of multivariate functions using conditionally Gaussian tensor-product spline priors

    NARCIS (Netherlands)

    Jonge, de R.; Zanten, van J.H.

    2012-01-01

    We investigate posterior contraction rates for priors on multivariate functions that are constructed using tensor-product B-spline expansions. We prove that using a hierarchical prior with an appropriate prior distribution on the partition size and Gaussian prior weights on the B-spline

  7. DOE final report phase one startup, Waste Receiving and Processing Facility (WRAP)

    International Nuclear Information System (INIS)

    Jasen, W.G.

    1998-01-01

    This document is to validate that the WRAP facility is physically ready to start up phase 1, and that the managers and operators are prepared to safely manage and operate the facility when all pre-start findings have been satisfactorily corrected. The DOE Readiness Assessment (RA) team spent a week on-site at Waste Receiving and Processing Module 1 (WRAP-1) to validate the readiness for phase 1 start up of facility. The Contractor and DOE staff were exceptionally cooperative and contributed significantly to the overall success of the RA. The procedures and Conduct of Operations areas had significant discrepancies, many of which should have been found by the contractor review team. In addition the findings of the contractor review team should have led the WRAP-1 management team to correcting the root causes of the findings prior to the DOE RA team review. The findings and observations include many issues that the team believes should have been found by the contractor review and corrective actions taken. A significantly improved Operational Readiness Review (ORR) process and corrective actions of root causes must be fully implemented by the contractor prior to the performance of the contractor ORR for phase 2 operations. The pre-start findings as a result of this independent DOE Readiness Assessment are presented

  8. Adaptive nonparametric Bayesian inference using location-scale mixture priors

    NARCIS (Netherlands)

    Jonge, de R.; Zanten, van J.H.

    2010-01-01

    We study location-scale mixture priors for nonparametric statistical problems, including multivariate regression, density estimation and classification. We show that a rate-adaptive procedure can be obtained if the prior is properly constructed. In particular, we show that adaptation is achieved if

  9. Assessment of prior learning in vocational education and training

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    ’ knowledge, skills and competences during the students’ performances and the methods that the teachers apply in order to assess the students’ prior learning in relation to the regulations of the current VET-program. In particular the study focuses on how to assess not only the students’ explicated knowledge......The article deals about the results of a study of the assessment of prior learning among adult workers who want to obtain formal qualifications as skilled workers. The study contributes to developing methods for assessing prior learning including both the teachers’ ways of eliciting the students...... and skills but also their competences, i.e. the way the students use their skills and knowledge to perform in practice. Based on a description of the assessment procedures the article discusses central issues in relation to the assessment of prior learning. The empirical data have been obtained in the VET...

  10. A flexible WLAN receiver

    NARCIS (Netherlands)

    Schiphorst, Roelof; Hoeksema, F.W.; Slump, Cornelis H.

    2003-01-01

    Flexible radio receivers are also called Software Defined Radios (SDRs) [1], [2]. The focus of our SDR project [3] is on designing the front end, from antenna to demodulation in bits, of a °exible, multi-standard WLAN receiver. We try to combine an instance of a (G)FSK receiver (Bluetooth) with an

  11. Incidence of Clostridium difficile infection in patients receiving high-risk antibiotics with or without a proton pump inhibitor.

    Science.gov (United States)

    Gordon, D; Young, L R; Reddy, S; Bergman, C; Young, J D

    2016-02-01

    Considering the incidence and severity of Clostridium difficile infection (CDI), risk reduction strategies are crucial. Prior studies suggest that proton pump inhibitor (PPI) use can increase the risk of CDI over antibiotics alone; however, data and guidelines have been conflicting. The aim was to compare CDI incidence in patients receiving high-risk antibiotics, comparing rates in those prescribed a PPI versus those without overlapping PPI exposure. This retrospective cohort study assessed the incidence of CDI in veterans receiving high-risk antibiotics over an approximately three-year period. High-risk antibiotics were defined as: ciprofloxacin, levofloxacin, moxifloxacin, clindamycin, ceftriaxone, cefotaxime, ceftazidime, or cefixime. We identified subjects who were prescribed any high-risk antibiotic, finding 3513 on a concomitant PPI and 6149 not taking a PPI. Of these subjects, 111 were diagnosed with CDI and met inclusion criteria. Baseline characteristics, CDI severity, length of hospitalization and antibiotic therapy prior to infection were similar in both groups. The incidence of CDI was significantly higher in patients prescribed a PPI (odds ratio: 2.2; 95% confidence interval: 1.52-3.23; P=0.0001). A strong association was found between concurrent PPI use with fluoroquinolones (P=0.005) and clindamycin (P=0.045). The use of PPIs together with high-risk antibiotics was associated with a significantly higher incidence of CDI. Our study provides further support for the CDI prevention strategy of judicious PPI use, especially in patients receiving high-risk antibiotics. Prudent avoidance of PPIs may reduce the incidence of CDI, a major cause of morbidity and mortality worldwide. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  12. Complications in skin grafts when continuing antithrombotic therapy prior to cutaneous surgery requiring skin grafting

    DEFF Research Database (Denmark)

    Jarjis, Reem Dina; Jørgensen, Lone; Finnerup, Kenneth

    2015-01-01

    Abstract The risk of postoperative bleeding and wound healing complications in skin grafts among anticoagulated patients undergoing cutaneous surgery has not been firmly established. The objective was to examine the literature and assess the risk of postoperative bleeding or wound healing...... complications in skin grafts among anticoagulated patients, compared with patients who discontinue or patients who are not receiving antithrombotic therapy prior to cutaneous surgery requiring skin grafting. A systematic review examining the effect of antithrombotic therapy on cutaneous surgery was performed...... studies were of prospective and retrospective design. Most of the reviewed studies suggest that the use of antithrombotic therapy can increase the risk of bleeding complications in skin grafts. These complications are only wound threatening and not life threatening. Therefore, this is of concern mostly...

  13. Random template placement and prior information

    International Nuclear Information System (INIS)

    Roever, Christian

    2010-01-01

    In signal detection problems, one is usually faced with the task of searching a parameter space for peaks in the likelihood function which indicate the presence of a signal. Random searches have proven to be very efficient as well as easy to implement, compared e.g. to searches along regular grids in parameter space. Knowledge of the parameterised shape of the signal searched for adds structure to the parameter space, i.e., there are usually regions requiring to be densely searched while in other regions a coarser search is sufficient. On the other hand, prior information identifies the regions in which a search will actually be promising or may likely be in vain. Defining specific figures of merit allows one to combine both template metric and prior distribution and devise optimal sampling schemes over the parameter space. We show an example related to the gravitational wave signal from a binary inspiral event. Here the template metric and prior information are particularly contradictory, since signals from low-mass systems tolerate the least mismatch in parameter space while high-mass systems are far more likely, as they imply a greater signal-to-noise ratio (SNR) and hence are detectable to greater distances. The derived sampling strategy is implemented in a Markov chain Monte Carlo (MCMC) algorithm where it improves convergence.

  14. Personality, depressive symptoms and prior trauma exposure of new ...

    African Journals Online (AJOL)

    Background. Police officers are predisposed to trauma exposure. The development of depression and post-traumatic stress disorder (PTSD) may be influenced by personality style, prior exposure to traumatic events and prior depression. Objectives. To describe the personality profiles of new Metropolitan Police Service ...

  15. Uncertainty plus prior equals rational bias: an intuitive Bayesian probability weighting function.

    Science.gov (United States)

    Fennell, John; Baddeley, Roland

    2012-10-01

    Empirical research has shown that when making choices based on probabilistic options, people behave as if they overestimate small probabilities, underestimate large probabilities, and treat positive and negative outcomes differently. These distortions have been modeled using a nonlinear probability weighting function, which is found in several nonexpected utility theories, including rank-dependent models and prospect theory; here, we propose a Bayesian approach to the probability weighting function and, with it, a psychological rationale. In the real world, uncertainty is ubiquitous and, accordingly, the optimal strategy is to combine probability statements with prior information using Bayes' rule. First, we show that any reasonable prior on probabilities leads to 2 of the observed effects; overweighting of low probabilities and underweighting of high probabilities. We then investigate 2 plausible kinds of priors: informative priors based on previous experience and uninformative priors of ignorance. Individually, these priors potentially lead to large problems of bias and inefficiency, respectively; however, when combined using Bayesian model comparison methods, both forms of prior can be applied adaptively, gaining the efficiency of empirical priors and the robustness of ignorance priors. We illustrate this for the simple case of generic good and bad options, using Internet blogs to estimate the relevant priors of inference. Given this combined ignorant/informative prior, the Bayesian probability weighting function is not only robust and efficient but also matches all of the major characteristics of the distortions found in empirical research. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  16. Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging.

    Science.gov (United States)

    Zhang, Shuanghui; Liu, Yongxiang; Li, Xiang; Bi, Guoan

    2016-04-28

    This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR) algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP) estimation and the maximum likelihood estimation (MLE) are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT) and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

  17. Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging

    Directory of Open Access Journals (Sweden)

    Shuanghui Zhang

    2016-04-01

    Full Text Available This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP estimation and the maximum likelihood estimation (MLE are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

  18. The Role of Prior Knowledge in International Franchise Partner Recruitment

    OpenAIRE

    Wang, Catherine; Altinay, Levent

    2006-01-01

    Purpose To investigate the role of prior knowledge in the international franchise partner recruitment process and to evaluate how cultural distance influences the role of prior knowledge in this process. Design/Methodology/Approach A single embedded case study of an international hotel firm was the focus of the enquiry. Interviews, observations and document analysis were used as the data collection techniques. Findings Findings reveal that prior knowledge of the franchisor enab...

  19. HIT'91 (prospective, co-operative study for the treatment of malignant brain tumors in childhood): accuracy and acute toxicity of the irradiation of the craniospinal axis

    International Nuclear Information System (INIS)

    Kortmann, R.D.; Timmermann, B.; Bamberg, M.; Kuehl, J.; Willich, N.; Flentje, M.; Meisner, C.

    1999-01-01

    Background: It was the aim of the quality control program of the randomized trial HIT '91 (intensive chemotherapy before irradiation versus maintenance chemotherapy after irradiation) to assess prospectively the quality of neuroaxis irradiation with respect to the protocol guidelines and to evaluate acute toxicity with respect to treatment arm. Patients, Materials and Methods: Data of 134 patients undergoing irradiation of the craniospinal axis were available. Positioning aids, shielding techniques, treatment machines, choice of energy, total dose and fractionation were evaluated. A total of 651 simulation and verification films were analyzed to assess the coverage of the clinical target volume (whole brain, posterior fossa, sacral nerve roots) and deviations of field alignment between simulation and verification of first treatment. Field matching between whole brain and adjacent cranial spinal fields was analyzed with respect to site and width of junction. Acute maximal side effects were evaluated according to a modified WHO score for neurotoxicity, infections, skin, mucosa and myelotoxicity. Results: In 91.3% of patients contemporary positioning aids and individualized shielding techniques were used to assure a reproducible treatment. In 98 patients (73.1%) linear accelerators and in 36 patients (26.8%) 60 Cobalt machines were used. Single and total dose were administered according to the protocol guidelines in more than 90% of patients. In 20.2% of patients the cribriform plate, in 1.4% the middle cranial fossa and in 21.1% the posterior fossa and in 4.5% the 2nd sacral segment were incompletely encompassed by the treatment portals. Ninety-five percent of deviations of field alignment were less than 13.0 mm (whole brain) and 12 mm (cranial spinal field) with a random error between 4.9 and 7.6 mm (whole brain) and 6.9 mm and 9.9 mm (spinal canal), respectively. In 77.5% of patients the junctions between whole brain and cranial spinal fields were placed without a

  20. A state-space model for estimating detailed movements and home range from acoustic receiver data

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Weng, Kevin

    2013-01-01

    We present a state-space model for acoustic receiver data to estimate detailed movement and home range of individual fish while accounting for spatial bias. An integral part of the approach is the detection function, which models the probability of logging tag transmissions as a function of dista......We present a state-space model for acoustic receiver data to estimate detailed movement and home range of individual fish while accounting for spatial bias. An integral part of the approach is the detection function, which models the probability of logging tag transmissions as a function...... that the location error scales log-linearly with detection range and movement speed. This result can be used as guideline for designing network layout when species movement capacity and acoustic environment are known or can be estimated prior to network deployment. Finally, as an example, the state-space model...... is used to estimate home range and movement of a reef fish in the Pacific Ocean....

  1. Advanced prior modeling for 3D bright field electron tomography

    Science.gov (United States)

    Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.

    2015-03-01

    Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.

  2. ASTRID© - Advanced Solar Tubular ReceIver Design: A powerful tool for receiver design and optimization

    Science.gov (United States)

    Frantz, Cathy; Fritsch, Andreas; Uhlig, Ralf

    2017-06-01

    In solar tower power plants the receiver is one of the critical components. It converts the solar radiation into heat and must withstand high heat flux densities and high daily or even hourly gradients (due to passage of clouds). For this reason, the challenge during receiver design is to find a reasonable compromise between receiver efficiency, reliability, lifetime and cost. There is a strong interaction between the heliostat field, the receiver and the heat transfer fluid. Therefore, a proper receiver design needs to consider these components within the receiver optimization. There are several design and optimization tools for receivers, but most of them focus only on the receiver, ignoring the heliostat field and other parts of the plant. During the last years DLR developed the ASTRIDcode for tubular receiver concept simulation. The code comprises both a high and a low-detail model. The low-detail model utilizes a number of simplifications which allow the user to screen a high number of receiver concepts for optimization purposes. The high-detail model uses a FE model and is able to compute local absorber and salt temperatures with high accuracy. One key strength of the ASTRIDcode is its interface to a ray tracing software which simulates a realistic heat flux distributions on the receiver surface. The results generated by the ASTRIDcode have been validated by CFD simulations and measurement data.

  3. Understanding sleep disturbance in athletes prior to important competitions.

    Science.gov (United States)

    Juliff, Laura E; Halson, Shona L; Peiffer, Jeremiah J

    2015-01-01

    Anecdotally many athletes report worse sleep in the nights prior to important competitions. Despite sleep being acknowledged as an important factor for optimal athletic performance and overall health, little is understood about athlete sleep around competition. The aims of this study were to identify sleep complaints of athletes prior to competitions and determine whether complaints were confined to competition periods. Cross-sectional study. A sample of 283 elite Australian athletes (129 male, 157 female, age 24±5 y) completed two questionnaires; Competitive Sport and Sleep questionnaire and the Pittsburgh Sleep Quality Index. 64.0% of athletes indicated worse sleep on at least one occasion in the nights prior to an important competition over the past 12 months. The main sleep problem specified by athletes was problems falling asleep (82.1%) with the main reasons responsible for poor sleep indicated as thoughts about the competition (83.5%) and nervousness (43.8%). Overall 59.1% of team sport athletes reported having no strategy to overcome poor sleep compared with individual athletes (32.7%, p=0.002) who utilised relaxation and reading as strategies. Individual sport athletes had increased likelihood of poor sleep as they aged. The poor sleep reported by athletes prior to competition was situational rather than a global sleep problem. Poor sleep is common prior to major competitions in Australian athletes, yet most athletes are unaware of strategies to overcome the poor sleep experienced. It is essential coaches and scientists monitor and educate both individual and team sport athletes to facilitate sleep prior to important competitions. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  4. Nudging toward Inquiry: Awakening and Building upon Prior Knowledge

    Science.gov (United States)

    Fontichiaro, Kristin, Comp.

    2010-01-01

    "Prior knowledge" (sometimes called schema or background knowledge) is information one already knows that helps him/her make sense of new information. New learning builds on existing prior knowledge. In traditional reporting-style research projects, students bypass this crucial step and plow right into answer-finding. It's no wonder that many…

  5. 5 CFR 6201.103 - Prior approval for outside employment.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Prior approval for outside employment. 6201.103 Section 6201.103 Administrative Personnel EXPORT-IMPORT BANK OF THE UNITED STATES SUPPLEMENTAL STANDARDS OF ETHICAL CONDUCT FOR EMPLOYEES OF THE EXPORT-IMPORT BANK OF THE UNITED STATES § 6201.103 Prior...

  6. Prevention of dimethylsulfoxide-related nausea and vomiting by prophylactic administration of ondansetron for patients receiving autologous cryopreserved peripheral blood stem cells.

    Science.gov (United States)

    Eisenberg, Seth; Wickline, Mihkaila; Linenberger, Michael; Gooley, Ted; Holmberg, Leona

    2013-05-01

    To evaluate the effectiveness of ondansetron for the prevention of nausea and vomiting from dimethylsulfoxide (DMSO) during autologous stem cell transplantation (ASCT) infusion. Nonrandomized cohort using historical control. Comprehensive cancer center outpatient infusion department. 50 patients receiving ASCT in the outpatient setting. Patients were assessed for nausea and vomiting on their infusion day using the Multinational Association of Supportive Care in Cancer Antiemesis Tool (MAT) at arrival, pre-ASCT infusion, pre-ondansetron administration, prior to the first bag, and after each bag of stem cells. A standard script was used to ensure consistency. Ondansetron, 16 mg IV, was administered 30-90 minutes prior to each ASCT infusion. Number and volume of stem cells bags, as well as infusion rate and emesis episodes, were recorded. Nausea scores and vomiting episodes were compared to historical data. Subjectivity of nausea, potential Hawthorne Effect. Forty-five percent of patients had an MAT score greater than 2 on arrival, decreasing to 18% after receiving ondansetron before the first bag. Twenty-four percent had MAT increases of more than two points by infusion end compared to 58% in the historic control group. Eighteen percent of patients vomited compared to 28% of historic controls. The administration of 16 mg of IV ondansetron significantly reduced DMSO-related nausea and episodes of vomiting in patients receiving ASCT. Prophylactic administration of ondansetron had a positive effect on reducing nausea symptoms and episodes of vomiting during ASCT infusions. These results prompted a change in clinical practice. More research is required to determine whether the inclusion of other antiemetic agents would provide even greater benefit. To date, no other published studies have explored the benefits of premedicating patients with ondansetron prior to ASCT infusions. This study is the first to establish efficacy of ondansetron for an unlabeled indication. These

  7. Results of subionospheric radio LF monitoring prior to the Tokachi (M=8, Hokkaido, 25 September 2003 earthquake

    Directory of Open Access Journals (Sweden)

    A. V. Shvets

    2004-01-01

    Full Text Available Results of simultaneous LF subionospheric monitoring over two different propagation paths prior to the very strong Tokachi earthquake (near the east coast of Hokkaido Island, 25 September 2003 of magnitude 8.3 are presented firstly. Nighttime amplitude fluctuations of the Japanese Time Standard Transmitter (JG2AS, 40kHz signal received at Moshiri (Japan, 142°E, 44°N and at Petropavlovsk-Kamchatski (Russia, 158°E, 53°N were analyzed. As a possible precursory signature we observed synchronous intensification of quasi periodical 16-day variations of the dispersion in the signals received at both observation stations before the earthquake. The strongest deviations observed as a rule were depletions of signal amplitude probably connected with increase of loss in the ionosphere by the enhancement of turbulence. This is due to dissipation of internal gravity waves (IGW at the lower ionosphere heights. A scheme for seismo-IGW-planetary waves (PW interconnection has been justified to explain the observed connection with strong earthquakes. It considers the seasonal variability in the signal.

  8. The chemotherapeutic agent paclitaxel selectively impairs reversal learning while sparing prior learning, new learning and episodic memory.

    Science.gov (United States)

    Panoz-Brown, Danielle; Carey, Lawrence M; Smith, Alexandra E; Gentry, Meredith; Sluka, Christina M; Corbin, Hannah E; Wu, Jie-En; Hohmann, Andrea G; Crystal, Jonathon D

    2017-10-01

    Chemotherapy is widely used to treat patients with systemic cancer. The efficacy of cancer therapies is frequently undermined by adverse side effects that have a negative impact on the quality of life of cancer survivors. Cancer patients who receive chemotherapy often experience chemotherapy-induced cognitive impairment across a variety of domains including memory, learning, and attention. In the current study, the impact of paclitaxel, a taxane derived chemotherapeutic agent, on episodic memory, prior learning, new learning, and reversal learning were evaluated in rats. Neurogenesis was quantified post-treatment in the dentate gyrus of the same rats using immunostaining for 5-Bromo-2'-deoxyuridine (BrdU) and Ki67. Paclitaxel treatment selectively impaired reversal learning while sparing episodic memory, prior learning, and new learning. Furthermore, paclitaxel-treated rats showed decreases in markers of hippocampal cell proliferation, as measured by markers of cell proliferation assessed using immunostaining for Ki67 and BrdU. This work highlights the importance of using multiple measures of learning and memory to identify the pattern of impaired and spared aspects of chemotherapy-induced cognitive impairment. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Novel joint TOA/RSSI-based WCE location tracking method without prior knowledge of biological human body tissues.

    Science.gov (United States)

    Ito, Takahiro; Anzai, Daisuke; Jianqing Wang

    2014-01-01

    This paper proposes a novel joint time of arrival (TOA)/received signal strength indicator (RSSI)-based wireless capsule endoscope (WCE) location tracking method without prior knowledge of biological human tissues. Generally, TOA-based localization can achieve much higher localization accuracy than other radio frequency-based localization techniques, whereas wireless signals transmitted from a WCE pass through various kinds of human body tissues, as a result, the propagation velocity inside a human body should be different from one in free space. Because the variation of propagation velocity is mainly affected by the relative permittivity of human body tissues, instead of pre-measurement for the relative permittivity in advance, we simultaneously estimate not only the WCE location but also the relative permittivity information. For this purpose, this paper first derives the relative permittivity estimation model with measured RSSI information. Then, we pay attention to a particle filter algorithm with the TOA-based localization and the RSSI-based relative permittivity estimation. Our computer simulation results demonstrates that the proposed tracking methods with the particle filter can accomplish an excellent localization accuracy of around 2 mm without prior information of the relative permittivity of the human body tissues.

  10. GNSS Software Receiver for UAVs

    DEFF Research Database (Denmark)

    Olesen, Daniel Madelung; Jakobsen, Jakob; von Benzon, Hans-Henrik

    2016-01-01

    This paper describes the current activities of GPS/GNSS Software receiver development at DTU Space. GNSS Software receivers have received a great deal of attention in the last two decades and numerous implementations have already been presented. DTU Space has just recently started development of ...... of our own GNSS software-receiver targeted for mini UAV applications, and we will in in this paper present our current progress and briefly discuss the benefits of Software Receivers in relation to our research interests....

  11. Source Localization by Entropic Inference and Backward Renormalization Group Priors

    Directory of Open Access Journals (Sweden)

    Nestor Caticha

    2015-04-01

    Full Text Available A systematic method of transferring information from coarser to finer resolution based on renormalization group (RG transformations is introduced. It permits building informative priors in finer scales from posteriors in coarser scales since, under some conditions, RG transformations in the space of hyperparameters can be inverted. These priors are updated using renormalized data into posteriors by Maximum Entropy. The resulting inference method, backward RG (BRG priors, is tested by doing simulations of a functional magnetic resonance imaging (fMRI experiment. Its results are compared with a Bayesian approach working in the finest available resolution. Using BRG priors sources can be partially identified even when signal to noise ratio levels are up to ~ -25dB improving vastly on the single step Bayesian approach. For low levels of noise the BRG prior is not an improvement over the single scale Bayesian method. Analysis of the histograms of hyperparameters can show how to distinguish if the method is failing, due to very high levels of noise, or if the identification of the sources is, at least partially possible.

  12. Stacked Transformer for Driver Gain and Receive Signal Splitting

    Science.gov (United States)

    Driscoll, Kevin R.

    2013-01-01

    In a high-speed signal transmission system that uses transformer coupling, there is a need to provide increased transmitted signal strength without adding active components. This invention uses additional transformers to achieve the needed gain. The prior art uses stronger drivers (which require an IC redesign and a higher power supply voltage), or the addition of another active component (which can decrease reliability, increase power consumption, reduce the beneficial effect of serializer/deserializer preemphasis or deemphasis, and/or interfere with fault containment mechanisms), or uses a different transformer winding ratio (which requires redesign of the transformer and may not be feasible with high-speed signals that require a 1:1 winding ratio). This invention achieves the required gain by connecting the secondaries of multiple transformers in series. The primaries of these transformers are currently either connected in parallel or are connected to multiple drivers. There is also a need to split a receive signal to multiple destinations with minimal signal loss. Additional transformers can achieve the split. The prior art uses impedance-matching series resistors that cause a loss of signal. Instead of causing a loss, most instantiations of this invention would actually provide gain. Multiple transformers are used instead of multiple windings on a single transformer because multiple windings on the same transformer would require a redesign of the transformer, and may not be feasible with high-speed transformers that usually require a bifilar winding with a 1:1 ratio. This invention creates the split by connecting the primaries of multiple transformers in series. The secondary of each transformer is connected to one of the intended destinations without the use of impedance-matching series resistors.

  13. Solar advanced internal film receiver

    International Nuclear Information System (INIS)

    Torre Cabezas, M. de la

    1990-01-01

    In a Solar Central Internal Film Receiver, the heat absorbing fluid (a molten nitrate salt) flows in a thin film down over the non illuminated side of an absorber panel. Since the molten salt working fluid is not contained in complicated tube manifolds, the receiver design is simples than a conventional tube type-receiver resulting in a lower cost and a more reliable receiver. The Internal Film Receiver can be considered as an alternative to the Direct Absorption Receiver, in the event that the current problems of the last one can not be solved. It also describes here the test facility which will be used for its solar test, and the test plans foreseen. (Author) 17 refs

  14. Customizable Digital Receivers for Radar

    Science.gov (United States)

    Moller, Delwyn; Heavey, Brandon; Sadowy, Gregory

    2008-01-01

    Compact, highly customizable digital receivers are being developed for the system described in 'Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets' (NPO-43962), NASA Tech Briefs, Vol. 31, No. 7 (August 2007), page 72. The receivers are required to operate in unison, sampling radar returns received by the antenna elements in a digital beam-forming (DBF) mode. The design of these receivers could also be adapted to commercial radar systems. At the time of reporting the information for this article, there were no commercially available digital receivers capable of satisfying all of the operational requirements and compact enough to be mounted directly on the antenna elements. A provided figure depicts the overall system of which the digital receivers are parts. Each digital receiver includes an analog-to-digital converter (ADC), a demultiplexer (DMUX), and a field-programmable gate array (FPGA). The ADC effects 10-bit band-pass sampling of input signals having frequencies up to 3.5 GHz. The input samples are demultiplexed at a user-selectable rate of 1:2 or 1:4, then buffered in part of the FPGA that functions as a first-in/first-out (FIFO) memory. Another part of the FPGA serves as a controller for the ADC, DMUX, and FIFO memory and as an interface between (1) the rest of the receiver and (2) a front-panel data port (FPDP) bus, which is an industry-standard parallel data bus that has a high data-rate capability and multichannel configuration suitable for DBF. Still other parts of the FPGA in each receiver perform signal-processing functions. The digital receivers can be configured to operate in a stand-alone mode, or in a multichannel mode as needed for DBF. The customizability of the receiver makes it applicable to a broad range of system architectures. The capability for operation of receivers in either a stand-alone or a DBF mode enables the use of the receivers in an unprecedentedly wide variety of radar systems.

  15. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  16. Identification of subsurface structures using electromagnetic data and shape priors

    Energy Technology Data Exchange (ETDEWEB)

    Tveit, Svenn, E-mail: svenn.tveit@uni.no [Uni CIPR, Uni Research, Bergen 5020 (Norway); Department of Mathematics, University of Bergen, Bergen 5020 (Norway); Bakr, Shaaban A., E-mail: shaaban.bakr1@gmail.com [Department of Mathematics, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Uni CIPR, Uni Research, Bergen 5020 (Norway); Lien, Martha, E-mail: martha.lien@octio.com [Uni CIPR, Uni Research, Bergen 5020 (Norway); Octio AS, Bøhmergaten 44, Bergen 5057 (Norway); Mannseth, Trond, E-mail: trond.mannseth@uni.no [Uni CIPR, Uni Research, Bergen 5020 (Norway); Department of Mathematics, University of Bergen, Bergen 5020 (Norway)

    2015-03-01

    We consider the inverse problem of identifying large-scale subsurface structures using the controlled source electromagnetic method. To identify structures in the subsurface where the contrast in electric conductivity can be small, regularization is needed to bias the solution towards preserving structural information. We propose to combine two approaches for regularization of the inverse problem. In the first approach we utilize a model-based, reduced, composite representation of the electric conductivity that is highly flexible, even for a moderate number of degrees of freedom. With a low number of parameters, the inverse problem is efficiently solved using a standard, second-order gradient-based optimization algorithm. Further regularization is obtained using structural prior information, available, e.g., from interpreted seismic data. The reduced conductivity representation is suitable for incorporation of structural prior information. Such prior information cannot, however, be accurately modeled with a gaussian distribution. To alleviate this, we incorporate the structural information using shape priors. The shape prior technique requires the choice of kernel function, which is application dependent. We argue for using the conditionally positive definite kernel which is shown to have computational advantages over the commonly applied gaussian kernel for our problem. Numerical experiments on various test cases show that the methodology is able to identify fairly complex subsurface electric conductivity distributions while preserving structural prior information during the inversion.

  17. PIRPLE: a penalized-likelihood framework for incorporation of prior images in CT reconstruction

    International Nuclear Information System (INIS)

    Stayman, J Webster; Dang, Hao; Ding, Yifu; Siewerdsen, Jeffrey H

    2013-01-01

    Over the course of diagnosis and treatment, it is common for a number of imaging studies to be acquired. Such imaging sequences can provide substantial patient-specific prior knowledge about the anatomy that can be incorporated into a prior-image-based tomographic reconstruction for improved image quality and better dose utilization. We present a general methodology using a model-based reconstruction approach including formulations of the measurement noise that also integrates prior images. This penalized-likelihood technique adopts a sparsity enforcing penalty that incorporates prior information yet allows for change between the current reconstruction and the prior image. Moreover, since prior images are generally not registered with the current image volume, we present a modified model-based approach that seeks a joint registration of the prior image in addition to the reconstruction of projection data. We demonstrate that the combined prior-image- and model-based technique outperforms methods that ignore the prior data or lack a noise model. Moreover, we demonstrate the importance of registration for prior-image-based reconstruction methods and show that the prior-image-registered penalized-likelihood estimation (PIRPLE) approach can maintain a high level of image quality in the presence of noisy and undersampled projection data. (paper)

  18. Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

    Science.gov (United States)

    Rossi, Carmine; Shrier, Ian; Marshall, Lee; Cnossen, Sonya; Schwartzman, Kevin; Klein, Marina B; Schwarzer, Guido; Greenaway, Chris

    2012-01-01

    International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV). We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2%) and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%). HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million) are estimated to be chronically infected with HBV. The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of international migrants can become an important component of HBV

  19. Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Carmine Rossi

    Full Text Available BACKGROUND: International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV. We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. METHODS AND FINDINGS: Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2% and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%. HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million are estimated to be chronically infected with HBV. CONCLUSIONS: The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of

  20. Comparative Evaluation of Serotonin Toxicity among Veterans Affairs Patients Receiving Linezolid and Vancomycin

    Science.gov (United States)

    Patel, N.; Rivera, A.; Tristani, L.; Lazariu, V.; Vandewall, H.; McNutt, L. A.

    2013-01-01

    Despite the theoretical risk of serotonin toxicity (ST) with linezolid, “real-world” clinical evaluations of the risk of ST in patients receiving linezolid have been limited to case reports and noncomparator studies. An observational, matched-cohort study was conducted to evaluate the risk of ST among hospitalized patients who received linezolid or vancomycin at the Upstate New York Veterans Affairs Healthcare Network (Veterans Integrated Service Network 2 [VISN-2]). Matching criteria included VISN-2 hospital, hospital ward, prior hospital length of stay, age, and baseline platelet counts. The patients' electronic medical records were evaluated for symptoms consistent with ST and the Hunter serotonin toxicity criteria (HSTC) using an intensive, natural word search algorithm. The study included 251 matched pairs. Demographics and comorbidities were similar between groups. Over half of the study population received at least one concurrent medication with serotonergic activity. Receipt of agents with serotonergic activity was more pronounced in the vancomycin group, and the higher frequency was due to concomitant antihistamine and antiemetic use. Antidepressant use, including selective serotonin reuptake inhibitors (SSRIs), was similar between groups. No patients in either group were found to meet the criteria using the word search algorithm for ST. Fewer linezolid patients than vancomycin patients met the HSTC overall (3.2% versus 8.8%) and when stratified by receipt of a concurrent serotonergic agent (4.3% versus 12.4%). Of the patients meeting the HSTC, most had past or present comorbidities that may have contributed to or overlapped the HSTC. This study of hospitalized patients revealed comparably low frequencies of adverse events potentially related to ST among patients who received linezolid or vancomycin. PMID:24041888

  1. Prevalence of prior HIV testing and associated factors among MSM in Zhejiang Province, China: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Runhua Li

    2016-11-01

    Full Text Available Abstract Background Men who have sex with men (MSM have become one of high-risk population for human immunodeficiency virus (HIV infection, due to their multiple sex partners and unprotected anal intercourse. Promoting HIV testing is an effective strategy for the prevention and control of HIV infection. We assessed the factors associated with a prior HIV testing history, which could provide guidance for implementation of future HIV intervention programs. Methods A cross-sectional study was conducted in three cities of Zhejiang Province, namely, Hangzhou, Ningbo and Wenzhou, using respondent-driven sampling, between December 2013 and June 2014. A face-to-face questionnaire survey was employed to collect relevant information about HIV testing. Univariate and multivariate logistic regression analyses were used to identify the factors associated with a prior HIV testing history. Results The adjusted rate of prior HIV testing among MSM in Zhejiang Province was 55.9 %. The adjusted rates of HIV and syphilis infections among MSM in Zhejiang Province were 14.0 % and 11.4 %, respectively. A weighted multivariate analysis showed that MSM of older age were more likely to be tested, as were MSM with higher level of education, self-reported homosexuality and a higher frequency of receiving AIDS/sexually transmitted infections educational intervention in the past year. MSM with suicidal inclination and self-perceived lower possibility of HIV infection were less likely to report ever having undergone an HIV test. Conclusions The prevalence of prior HIV testing among MSM in Zhejiang Province, China is low. Effective and more frequent interventional measures should be adopted to improve risk awareness and psychosocial support for younger, less educated MSM, and to encourage more MSM to undergo HIV testing.

  2. Incorporating priors for EEG source imaging and connectivity analysis

    Directory of Open Access Journals (Sweden)

    Xu eLei

    2015-08-01

    Full Text Available Electroencephalography source imaging (ESI is a useful technique to localize the generators from a given scalp electric measurement and to investigate the temporal dynamics of the large-scale neural circuits. By introducing reasonable priors from other modalities, ESI reveals the most probable sources and communication structures at every moment in time. Here, we review the available priors from such techniques as magnetic resonance imaging (MRI, functional MRI (fMRI, and positron emission tomography (PET. The modality's specific contribution is analyzed from the perspective of source reconstruction. For spatial priors, such as EEG-correlated fMRI, temporally coherent networks and resting-state fMRI are systematically introduced in the ESI. Moreover, the fiber tracking (diffusion tensor imaging, DTI and neuro-stimulation techniques (transcranial magnetic stimulation, TMS are also introduced as the potential priors, which can help to draw inferences about the neuroelectric connectivity in the source space. We conclude that combining EEG source imaging with other complementary modalities is a promising approach towards the study of brain networks in cognitive and clinical neurosciences.

  3. Results of a phase I dose escalation study of eltrombopag in patients with advanced soft tissue sarcoma receiving doxorubicin and ifosfamide

    International Nuclear Information System (INIS)

    Chawla, Sant P; Staddon, Arthur; Hendifar, Andrew; Messam, Conrad A; Patwardhan, Rita; Kamel, Yasser Mostafa

    2013-01-01

    The objective of this Phase I dose escalation study was to explore the safety and tolerability of eltrombopag, an oral, nonpeptide, thrombopoietin receptor agonist, in patients with advanced soft tissue sarcoma (STS) and thrombocytopenia due to treatment with doxorubicin and ifosfamide (AI) combination chemotherapy. Patients aged 18 or older with histologically confirmed, locally advanced or metastatic STS were treated with 1 cycle of AI followed by AI with eltrombopag starting at Cycle 2, using 2 different dosing schedules. The study design included an eltrombopag dose escalation phase starting at 75 mg daily to determine the optimal biological dose (OBD). Eighteen patients were enrolled and 15 received at least 1 dose of chemotherapy; 3 patients withdrew prior to receiving eltrombopag. Seven, 4, and 1 patients received 75 mg, 100 mg, and 150 mg eltrombopag daily, respectively. No dose-limiting toxicities were reported. Due to slow recruitment, the study was closed prior to identifying an OBD. The most common hematologic adverse events (AEs) were thrombocytopenia (80%), neutropenia (73%), and anemia (67%). The most common nonhematologic AEs were fatigue (53%), alanine aminotransferase increased, constipation, and nausea (47% each). Eleven of 12 patients who received eltrombopag completed at least 2 chemotherapy cycles; all had increased platelet counts on Day 1 of Cycle 2 (cycle with eltrombopag) compared to Day 1 of Cycle 1 (cycle without eltrombopag). Although data are limited, safety data were consistent with the known toxicities of AI combination chemotherapy or the side effect profile of eltrombopag seen in other studies. Available data suggest a potential pre- and post-chemotherapy dosing scheme for eltrombopag when administered with AI chemotherapy, and support further investigation of eltrombopag treatment in patients with chemotherapy-induced thrombocytopenia

  4. Early Cognitive Outcomes Following Proton Radiation in Pediatric Patients With Brain and Central Nervous System Tumors

    International Nuclear Information System (INIS)

    Pulsifer, Margaret B.; Sethi, Roshan V.; Kuhlthau, Karen A.; MacDonald, Shannon M.; Tarbell, Nancy J.; Yock, Torunn I.

    2015-01-01

    Purpose: To report, from a longitudinal study, cognitive outcome in pediatric patients treated with proton radiation therapy (PRT) for central nervous system (CNS) tumors. Methods and Materials: Sixty patients receiving PRT for medulloblastoma (38.3%), gliomas (18.3%), craniopharyngioma (15.0%), ependymoma (11.7%), and other CNS tumors (16.7%) were administered age-appropriate measures of cognitive abilities at or near PRT initiation (baseline) and afterward (follow-up). Patients were aged ≥6 years at baseline to ensure consistency in neurocognitive measures. Results: Mean age was 12.3 years at baseline; mean follow-up interval was 2.5 years. Treatment included prior surgical resection (76.7%) and chemotherapy (61.7%). Proton radiation therapy included craniospinal irradiation (46.7%) and partial brain radiation (53.3%). At baseline, mean Wechsler Full Scale IQ was 104.6; means of all 4 Index scores were also in the average range. At follow-up, no significant change was observed in mean Wechsler Full Scale IQ, Verbal Comprehension, Perceptual Reasoning/Organization, or Working Memory. However, Processing Speed scores declined significantly (mean 5.2 points), with a significantly greater decline for subjects aged <12 years at baseline and those with the highest baseline scores. Cognitive outcome was not significantly related to gender, extent of radiation, radiation dose, tumor location, histology, socioeconomic status, chemotherapy, or history of surgical resection. Conclusions: Early cognitive outcomes after PRT for pediatric CNS tumors are encouraging, compared with published outcomes from photon radiation therapy

  5. Early Cognitive Outcomes Following Proton Radiation in Pediatric Patients With Brain and Central Nervous System Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Pulsifer, Margaret B., E-mail: mpulsifer@mgh.harvard.edu [Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts (United States); Sethi, Roshan V. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Kuhlthau, Karen A. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); MacDonald, Shannon M.; Tarbell, Nancy J.; Yock, Torunn I. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2015-10-01

    Purpose: To report, from a longitudinal study, cognitive outcome in pediatric patients treated with proton radiation therapy (PRT) for central nervous system (CNS) tumors. Methods and Materials: Sixty patients receiving PRT for medulloblastoma (38.3%), gliomas (18.3%), craniopharyngioma (15.0%), ependymoma (11.7%), and other CNS tumors (16.7%) were administered age-appropriate measures of cognitive abilities at or near PRT initiation (baseline) and afterward (follow-up). Patients were aged ≥6 years at baseline to ensure consistency in neurocognitive measures. Results: Mean age was 12.3 years at baseline; mean follow-up interval was 2.5 years. Treatment included prior surgical resection (76.7%) and chemotherapy (61.7%). Proton radiation therapy included craniospinal irradiation (46.7%) and partial brain radiation (53.3%). At baseline, mean Wechsler Full Scale IQ was 104.6; means of all 4 Index scores were also in the average range. At follow-up, no significant change was observed in mean Wechsler Full Scale IQ, Verbal Comprehension, Perceptual Reasoning/Organization, or Working Memory. However, Processing Speed scores declined significantly (mean 5.2 points), with a significantly greater decline for subjects aged <12 years at baseline and those with the highest baseline scores. Cognitive outcome was not significantly related to gender, extent of radiation, radiation dose, tumor location, histology, socioeconomic status, chemotherapy, or history of surgical resection. Conclusions: Early cognitive outcomes after PRT for pediatric CNS tumors are encouraging, compared with published outcomes from photon radiation therapy.

  6. Communications receivers principles and design

    CERN Document Server

    Rohde, Ulrich L; Zahnd, Hans

    2017-01-01

    This thoroughly updated guide offers comprehensive explanations of the science behind today’s radio receivers along with practical guidance on designing, constructing, and maintaining real-world communications systems. You will explore system planning, antennas and antenna coupling, amplifiers and gain control, filters, mixers, demodulation, digital communication, and the latest software defined radio (SDR) technology. Written by a team of telecommunication experts, Communications Receivers: Principles and Design, Fourth Edition, features technical illustrations, schematic diagrams, and detailed examples. Coverage includes: • Basic radio considerations • Radio receiver characteristics • Receiver system planning • Receiver implementation considerations • RF and baseband techniques for Software-Defined Radios • Transceiver SDR considerations • Antennas and antenna coupling • Mixers • Frequency sources and control • Ancillary receiver circuits • Performance measurement

  7. Penalising Model Component Complexity: A Principled, Practical Approach to Constructing Priors

    KAUST Repository

    Simpson, Daniel

    2017-04-06

    In this paper, we introduce a new concept for constructing prior distributions. We exploit the natural nested structure inherent to many model components, which defines the model component to be a flexible extension of a base model. Proper priors are defined to penalise the complexity induced by deviating from the simpler base model and are formulated after the input of a user-defined scaling parameter for that model component, both in the univariate and the multivariate case. These priors are invariant to repa-rameterisations, have a natural connection to Jeffreys\\' priors, are designed to support Occam\\'s razor and seem to have excellent robustness properties, all which are highly desirable and allow us to use this approach to define default prior distributions. Through examples and theoretical results, we demonstrate the appropriateness of this approach and how it can be applied in various situations.

  8. Penalising Model Component Complexity: A Principled, Practical Approach to Constructing Priors

    KAUST Repository

    Simpson, Daniel; Rue, Haavard; Riebler, Andrea; Martins, Thiago G.; Sø rbye, Sigrunn H.

    2017-01-01

    In this paper, we introduce a new concept for constructing prior distributions. We exploit the natural nested structure inherent to many model components, which defines the model component to be a flexible extension of a base model. Proper priors are defined to penalise the complexity induced by deviating from the simpler base model and are formulated after the input of a user-defined scaling parameter for that model component, both in the univariate and the multivariate case. These priors are invariant to repa-rameterisations, have a natural connection to Jeffreys' priors, are designed to support Occam's razor and seem to have excellent robustness properties, all which are highly desirable and allow us to use this approach to define default prior distributions. Through examples and theoretical results, we demonstrate the appropriateness of this approach and how it can be applied in various situations.

  9. On Bayesian reliability analysis with informative priors and censoring

    International Nuclear Information System (INIS)

    Coolen, F.P.A.

    1996-01-01

    In the statistical literature many methods have been presented to deal with censored observations, both within the Bayesian and non-Bayesian frameworks, and such methods have been successfully applied to, e.g., reliability problems. Also, in reliability theory it is often emphasized that, through shortage of statistical data and possibilities for experiments, one often needs to rely heavily on judgements of engineers, or other experts, for which means Bayesian methods are attractive. It is therefore important that such judgements can be elicited easily to provide informative prior distributions that reflect the knowledge of the engineers well. In this paper we focus on this aspect, especially on the situation that the judgements of the consulted engineers are based on experiences in environments where censoring has also been present previously. We suggest the use of the attractive interpretation of hyperparameters of conjugate prior distributions when these are available for assumed parametric models for lifetimes, and we show how one may go beyond the standard conjugate priors, using similar interpretations of hyper-parameters, to enable easier elicitation when censoring has been present in the past. This may even lead to more flexibility for modelling prior knowledge than when using standard conjugate priors, whereas the disadvantage of more complicated calculations that may be needed to determine posterior distributions play a minor role due to the advanced mathematical and statistical software that is widely available these days

  10. Prior surgical intervention and tumor size impact clinical outcome after precision radiotherapy for the treatment of optic nerve sheath meningiomas (ONSM)

    International Nuclear Information System (INIS)

    Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Debus, Jürgen; Combs, Stephanie E

    2011-01-01

    We analyzed our long-term experience with fractionated stereotactic radiotherapy (FSRT) in patients with meningioma of the optic nerve sheath (ONSM). Between January 1991 and January 2010, 40 patients with ONSM were treated using FSRT. Of these, 19 patients received radiotherapy as primary treatment, and 21 patients were treated after surgical resection. The median target volume was 9.2 ml, median total dose was 54 Gy in median single fractions of 1,8 Gy. Local progression-free survival was 100%. Median survival after FSRT was 60 months (range 4-228 months). In all patients overall toleration of FSRT was very good. Acute toxicity was mild. Prior to RT, 29 patients complained about any kind of visual impairment including visual field deficits, diplopia or amaurosis. Prior surgical resection was identified as a negative prognostic factor for visual outcome, whereas patients with larger tumor volumes demonstrated a higher number of patients with improvement of pre-existing visual deficits. Long-term outcome after FSRT for ONSM shows improved vision in patients not treated surgically prior to RT; moreover, the best improvement of visual deficits are observed in patients with larger target volumes. The absence of tumor recurrences supports that FSRT is a strong alternative to surgical resection especially in small tumors without extensive compression of normal tissue structures

  11. Action priors for learning domain invariances

    CSIR Research Space (South Africa)

    Rosman, Benjamin S

    2015-04-01

    Full Text Available behavioural invariances in the domain, by identifying actions to be prioritised in local contexts, invariant to task details. This information has the effect of greatly increasing the speed of solving new problems. We formalise this notion as action priors...

  12. Finding a minimally informative Dirichlet prior distribution using least squares

    International Nuclear Information System (INIS)

    Kelly, Dana; Atwood, Corwin

    2011-01-01

    In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straightforward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson λ, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in the form of a standard distribution (e.g., beta, gamma), and so a beta distribution is used as an approximation in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial model for common-cause failure, must be estimated from data that are often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.

  13. Finding a Minimally Informative Dirichlet Prior Distribution Using Least Squares

    International Nuclear Information System (INIS)

    Kelly, Dana; Atwood, Corwin

    2011-01-01

    In a Bayesian framework, the Dirichlet distribution is the conjugate distribution to the multinomial likelihood function, and so the analyst is required to develop a Dirichlet prior that incorporates available information. However, as it is a multiparameter distribution, choosing the Dirichlet parameters is less straight-forward than choosing a prior distribution for a single parameter, such as p in the binomial distribution. In particular, one may wish to incorporate limited information into the prior, resulting in a minimally informative prior distribution that is responsive to updates with sparse data. In the case of binomial p or Poisson, the principle of maximum entropy can be employed to obtain a so-called constrained noninformative prior. However, even in the case of p, such a distribution cannot be written down in closed form, and so an approximate beta distribution is used in the case of p. In the case of the multinomial model with parametric constraints, the approach of maximum entropy does not appear tractable. This paper presents an alternative approach, based on constrained minimization of a least-squares objective function, which leads to a minimally informative Dirichlet prior distribution. The alpha-factor model for common-cause failure, which is widely used in the United States, is the motivation for this approach, and is used to illustrate the method. In this approach to modeling common-cause failure, the alpha-factors, which are the parameters in the underlying multinomial aleatory model for common-cause failure, must be estimated from data that is often quite sparse, because common-cause failures tend to be rare, especially failures of more than two or three components, and so a prior distribution that is responsive to updates with sparse data is needed.

  14. Impact of prior treatment status and reasons for discontinuation on the efficacy and safety of fingolimod: Subgroup analyses of the Fingolimod Research Evaluating Effects of Daily Oral Therapy in Multiple Sclerosis (FREEDOMS) study.

    Science.gov (United States)

    Kremenchutzky, Marcelo; O'Connor, Paul; Hohlfeld, Reinhard; Zhang-Auberson, Lixin; von Rosenstiel, Philipp; Meng, Xiangyi; Grinspan, Augusto; Hashmonay, Ron; Kappos, Ludwig

    2014-05-01

    Fingolimod is a once-daily, oral sphingosine 1-phosphate receptor modulator approved for the treatment of relapsing multiple sclerosis. This post-hoc analysis of phase 3 FREEDOMS data assessed whether the effects of fingolimod are consistent among subgroups of patients defined by prior treatment history. Annualized relapse rate and safety profile of treatment with fingolimod 0.5mg, 1.25mg, or placebo once-daily for 24 months were analyzed in 1272 relapsing multiple sclerosis patients, by subgroups based on disease-modifying therapy history (treatment-naive; prior interferon-β or glatiramer acetate), reason for discontinuation of prior disease-modifying therapy (unsatisfactory therapeutic response or adverse events), and prior disease-modifying therapy duration. Both fingolimod doses significantly reduced annualized relapse rate in patients that received prior interferon-β or glatiramer acetate, discontinued prior disease-modifying therapy owing to unsatisfactory therapeutic effect, were treatment-naive, or had prior disease-modifying therapy duration of >1-3 years (P≤0.0301 for all comparisons vs placebo). Fingolimod 1.25mg resulted in greater reductions in annualized relapse rate in patients that discontinued prior disease-modifying therapy for adverse events or had prior disease-modifying therapy duration of ≤1 year or >3 years (P≤0.0194 vs placebo). Fingolimod demonstrated similar efficacy in relapsing multiple sclerosis patients regardless of prior treatment history. Clinicaltrials.gov identifier: NCT00289978. © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Active Prior Tactile Knowledge Transfer for Learning Tactual Properties of New Objects

    Directory of Open Access Journals (Sweden)

    Di Feng

    2018-02-01

    Full Text Available Reusing the tactile knowledge of some previously-explored objects (prior objects helps us to easily recognize the tactual properties of new objects. In this paper, we enable a robotic arm equipped with multi-modal artificial skin, like humans, to actively transfer the prior tactile exploratory action experiences when it learns the detailed physical properties of new objects. These experiences, or prior tactile knowledge, are built by the feature observations that the robot perceives from multiple sensory modalities, when it applies the pressing, sliding, and static contact movements on objects with different action parameters. We call our method Active Prior Tactile Knowledge Transfer (APTKT, and systematically evaluated its performance by several experiments. Results show that the robot improved the discrimination accuracy by around 10 % when it used only one training sample with the feature observations of prior objects. By further incorporating the predictions from the observation models of prior objects as auxiliary features, our method improved the discrimination accuracy by over 20 % . The results also show that the proposed method is robust against transferring irrelevant prior tactile knowledge (negative knowledge transfer.

  16. Figure-ground segmentation based on class-independent shape priors

    Science.gov (United States)

    Li, Yang; Liu, Yang; Liu, Guojun; Guo, Maozu

    2018-01-01

    We propose a method to generate figure-ground segmentation by incorporating shape priors into the graph-cuts algorithm. Given an image, we first obtain a linear representation of an image and then apply directional chamfer matching to generate class-independent, nonparametric shape priors, which provide shape clues for the graph-cuts algorithm. We then enforce shape priors in a graph-cuts energy function to produce object segmentation. In contrast to previous segmentation methods, the proposed method shares shape knowledge for different semantic classes and does not require class-specific model training. Therefore, the approach obtains high-quality segmentation for objects. We experimentally validate that the proposed method outperforms previous approaches using the challenging PASCAL VOC 2010/2012 and Berkeley (BSD300) segmentation datasets.

  17. Prior Exposure and Educational Environment towards Entrepreneurial Intention

    Directory of Open Access Journals (Sweden)

    Karla Soria-Barreto

    2017-07-01

    Full Text Available This research is based on the responses to a questionnaire applied to 351 students of business management in Chile and Colombia. Through the analysis of structural equations on Ajzen’s model, we found that entrepreneurial education, the University environment, and the prior entrepreneurial exposure are mediated by the factors of the Ajzen`s model to generate entrepreneurial intention in higher education students. The results show that entrepreneurial education strengthens the perceived control of behavior and, with it, albeit in a differentiated way, the entrepreneurial intention of men and women. University environment affects entrepreneurial intention through attitude towards entrepreneurship; and finally, the work experience, used as one of the variables that measure prior entrepreneurial exposure, explains the entrepreneurial intention inversely through the subjective norms. We found that gender has a moderate effect on perceived control of behavior and entrepreneurial education. The scarce studies on the impact of the University environment and the mixed results of the entrepreneurial education and prior entrepreneurial exposure toward entrepreneurial intention show the necessity for further research. A second contribution is the opportunity to present new evidence about the relationship between University environment, entrepreneurial education and prior exposure to developing countries of South America, including the gender effect (moderator for entrepreneurial intention. It is important to note that most of the research in this area applies to developed countries, and some scholars suggest that extrapolating the results is not convenient.

  18. Prior elicitation: Interactive spreadsheet graphics with sliders can be fun, and informative

    OpenAIRE

    Jones, G; Johnson, WO

    2014-01-01

    There are several approaches to setting priors in Bayesian data analysis. Some attempt to minimize the impact of the prior on the posterior, allowing the data to "speak for themselves," or to provide Bayesian inferences that have good frequentist properties. In contrast, this note focuses on priors where scientific knowledge is used, possibly partially informative. There are many articles on the use of such subjective information. We focus on using standard software for eliciting priors from ...

  19. In a randomized trial, the live attenuated tetravalent dengue vaccine TV003 is well-tolerated and highly immunogenic in subjects with flavivirus exposure prior to vaccination.

    Directory of Open Access Journals (Sweden)

    Stephen S Whitehead

    2017-05-01

    Full Text Available Infection caused by the four serotypes of dengue virus (DENV-1-4 is a leading cause of mosquito-borne disease. Clinically-severe dengue disease is more common when secondary dengue infection occurs following prior infection with a heterologous dengue serotype. Other flaviviruses such as yellow fever virus, Japanese encephalitis virus, and Zika virus, can also elicit antibodies which are cross-reactive to DENV. As candidate dengue vaccines become available in endemic settings and for individuals who have received other flavivirus vaccines, it is important to examine vaccine safety and immunogenicity in these flavivirus-experienced populations. We performed a randomized, controlled trial of the National Institutes of Health live attenuated tetravalent dengue vaccine candidate (TV003 in fifty-eight individuals with prior exposure to flavivirus infection or vaccine. As in prior studies of this vaccine in flavivirus-naive volunteers, flavivirus-experienced subjects received two doses of vaccine six months apart and were followed closely for clinical events, laboratory changes, viremia, and neutralizing antibody titers. TV003 was well tolerated with few adverse events other than rash, which was predominately mild. Following one dose, 87% of vaccinees had an antibody response to all four serotypes (tetravalent response, suggesting a robust immune response. In addition, 76% of vaccinees were viremic; mean peak titers ranged from 0.68–1.1 log10 PFU/mL and did not differ by serotype. The second dose of TV003 was not associated with viremia, rash, or a sustained boost in antibody titers indicating that a single dose of the vaccine is likely sufficient to prevent viral replication and thus protect against disease. In comparison to the viremia and neutralizing antibody response elicited by TV003 in flavivirus-naïve subjects from prior studies, we found that subjects who were flavivirus-exposed prior to vaccination exhibited slightly higher DENV-3 viremia

  20. Bayesian image reconstruction in SPECT using higher order mechanical models as priors

    International Nuclear Information System (INIS)

    Lee, S.J.; Gindi, G.; Rangarajan, A.

    1995-01-01

    While the ML-EM (maximum-likelihood-expectation maximization) algorithm for reconstruction for emission tomography is unstable due to the ill-posed nature of the problem, Bayesian reconstruction methods overcome this instability by introducing prior information, often in the form of a spatial smoothness regularizer. More elaborate forms of smoothness constraints may be used to extend the role of the prior beyond that of a stabilizer in order to capture actual spatial information about the object. Previously proposed forms of such prior distributions were based on the assumption of a piecewise constant source distribution. Here, the authors propose an extension to a piecewise linear model--the weak plate--which is more expressive than the piecewise constant model. The weak plate prior not only preserves edges but also allows for piecewise ramplike regions in the reconstruction. Indeed, for the application in SPECT, such ramplike regions are observed in ground-truth source distributions in the form of primate autoradiographs of rCBF radionuclides. To incorporate the weak plate prior in a MAP approach, the authors model the prior as a Gibbs distribution and use a GEM formulation for the optimization. They compare quantitative performance of the ML-EM algorithm, a GEM algorithm with a prior favoring piecewise constant regions, and a GEM algorithm with the weak plate prior. Pointwise and regional bias and variance of ensemble image reconstructions are used as indications of image quality. The results show that the weak plate and membrane priors exhibit improved bias and variance relative to ML-EM techniques

  1. 'Chaos' in superregenerative receivers

    International Nuclear Information System (INIS)

    Commercon, Jean-Claude; Badard, Robert

    2005-01-01

    The superregenerative principle has been known since the early 1920s. The circuit is extremely simple and extremely sensitive. Today, superheterodyne receivers generally supplant superregenerative receivers in most applications because there are several undesirable characteristics: poor selectivity, reradiation, etc. Superregenerative receivers undergo a revival in recent papers for wireless systems, where low cost and very low power consumption are relevant: house/building meters (such as water, energy, gas counter), personal computer environment (keyboard, mouse), etc. Another drawback is the noise level which is higher than that of a well-designed superheterodyne receiver; without an antenna input signal, the output of the receiver hears in an earphone as a waterfall noise; this sound principally is the inherent input noise amplified and detected by the circuit; however, when the input noise is negligible with respect of an antenna input signal, we are faced to an other source of 'noise' self-generated by the superregenerative working. The main objective of this paper concerns this self-generated noise coming from an exponential growing followed by a re-injection process for which the final state is a function of the phase of the input signal

  2. Physical examination prior to initiating hormonal contraception: a systematic review.

    Science.gov (United States)

    Tepper, Naomi K; Curtis, Kathryn M; Steenland, Maria W; Marchbanks, Polly A

    2013-05-01

    Provision of contraception is often linked with physical examination, including clinical breast examination (CBE) and pelvic examination. This review was conducted to evaluate the evidence regarding outcomes among women with and without physical examination prior to initiating hormonal contraceptives. The PubMed database was searched from database inception through March 2012 for all peer-reviewed articles in any language concerning CBE and pelvic examination prior to initiating hormonal contraceptives. The quality of each study was assessed using the United States Preventive Services Task Force grading system. The search did not identify any evidence regarding outcomes among women screened versus not screened with CBE prior to initiation of hormonal contraceptives. The search identified two case-control studies of fair quality which compared women who did or did not undergo pelvic examination prior to initiating oral contraceptives (OCs) or depot medroxyprogesterone acetate (DMPA). No differences in risk factors for cervical neoplasia, incidence of sexually transmitted infections, incidence of abnormal Pap smears or incidence of abnormal wet mount findings were observed. Although women with breast cancer should not use hormonal contraceptives, there is little utility in screening prior to initiation, due to the low incidence of breast cancer and uncertain value of CBE among women of reproductive age. Two fair quality studies demonstrated no differences between women who did or did not undergo pelvic examination prior to initiating OCs or DMPA with respect to risk factors or clinical outcomes. In addition, pelvic examination is not likely to detect any conditions for which hormonal contraceptives would be unsafe. Published by Elsevier Inc.

  3. 46 CFR 221.111 - Status of prior transactions-controlling dates.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Status of prior transactions-controlling dates. 221.111 Section 221.111 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS AFFECTING... MARITIME INTERESTS Savings Provisions § 221.111 Status of prior transactions—controlling dates. (a) The...

  4. On the use of a pruning prior for neural networks

    DEFF Research Database (Denmark)

    Goutte, Cyril

    1996-01-01

    We address the problem of using a regularization prior that prunes unnecessary weights in a neural network architecture. This prior provides a convenient alternative to traditional weight-decay. Two examples are studied to support this method and illustrate its use. First we use the sunspots...

  5. New Riemannian Priors on the Univariate Normal Model

    Directory of Open Access Journals (Sweden)

    Salem Said

    2014-07-01

    Full Text Available The current paper introduces new prior distributions on the univariate normal model, with the aim of applying them to the classification of univariate normal populations. These new prior distributions are entirely based on the Riemannian geometry of the univariate normal model, so that they can be thought of as “Riemannian priors”. Precisely, if {pθ ; θ ∈ Θ} is any parametrization of the univariate normal model, the paper considers prior distributions G( θ - , γ with hyperparameters θ - ∈ Θ and γ > 0, whose density with respect to Riemannian volume is proportional to exp(−d2(θ, θ - /2γ2, where d2(θ, θ - is the square of Rao’s Riemannian distance. The distributions G( θ - , γ are termed Gaussian distributions on the univariate normal model. The motivation for considering a distribution G( θ - , γ is that this distribution gives a geometric representation of a class or cluster of univariate normal populations. Indeed, G( θ - , γ has a unique mode θ - (precisely, θ - is the unique Riemannian center of mass of G( θ - , γ, as shown in the paper, and its dispersion away from θ - is given by γ.  Therefore, one thinks of members of the class represented by G( θ - , γ as being centered around θ - and  lying within a typical  distance determined by γ. The paper defines rigorously the Gaussian distributions G( θ - , γ and describes an algorithm for computing maximum likelihood estimates of their hyperparameters. Based on this algorithm and on the Laplace approximation, it describes how the distributions G( θ - , γ can be used as prior distributions for Bayesian classification of large univariate normal populations. In a concrete application to texture image classification, it is shown that  this  leads  to  an  improvement  in  performance  over  the  use  of  conjugate  priors.

  6. Prior indigenous technological species

    Science.gov (United States)

    Wright, Jason T.

    2018-01-01

    One of the primary open questions of astrobiology is whether there is extant or extinct life elsewhere the solar system. Implicit in much of this work is that we are looking for microbial or, at best, unintelligent life, even though technological artefacts might be much easier to find. Search for Extraterrestrial Intelligence (SETI) work on searches for alien artefacts in the solar system typically presumes that such artefacts would be of extrasolar origin, even though life is known to have existed in the solar system, on Earth, for eons. But if a prior technological, perhaps spacefaring, species ever arose in the solar system, it might have produced artefacts or other technosignatures that have survived to present day, meaning solar system artefact SETI provides a potential path to resolving astrobiology's question. Here, I discuss the origins and possible locations for technosignatures of such a prior indigenous technological species, which might have arisen on ancient Earth or another body, such as a pre-greenhouse Venus or a wet Mars. In the case of Venus, the arrival of its global greenhouse and potential resurfacing might have erased all evidence of its existence on the Venusian surface. In the case of Earth, erosion and, ultimately, plate tectonics may have erased most such evidence if the species lived Gyr ago. Remaining indigenous technosignatures might be expected to be extremely old, limiting the places they might still be found to beneath the surfaces of Mars and the Moon, or in the outer solar system.

  7. Prior information in structure estimation

    Czech Academy of Sciences Publication Activity Database

    Kárný, Miroslav; Nedoma, Petr; Khailova, Natalia; Pavelková, Lenka

    2003-01-01

    Roč. 150, č. 6 (2003), s. 643-653 ISSN 1350-2379 R&D Projects: GA AV ČR IBS1075102; GA AV ČR IBS1075351; GA ČR GA102/03/0049 Institutional research plan: CEZ:AV0Z1075907 Keywords : prior knowledge * structure estimation * autoregressive models Subject RIV: BC - Control Systems Theory Impact factor: 0.745, year: 2003 http://library.utia.cas.cz/separaty/historie/karny-0411258.pdf

  8. Assessment of Prior Learning in Adult Vocational Education and Training

    Directory of Open Access Journals (Sweden)

    Vibe Aarkrog

    2015-04-01

    Full Text Available The article deals about the results of a study of school-based Assessment of Prior Learning of adults who have enrolled as students in a VET college in order to qualify for occupations as skilled workers. Based on examples of VET teachers’ methods for assessing the students’ prior learning in the programs for gastronomes, respectively child care assistants the article discusses two issues in relation to Assessment of Prior Learing: the encounter of practical experience and school-based knowledge and the validity and reliability of the assessment procedures. Through focusing on the students’ knowing that and knowing why the assessment is based on a scholastic perception of the students’ needs for training, reflecting one of the most important challenges in Assessment of Prior Learning: how can practical experience be transformed into credits for the knowledge parts of the programs? The study shows that by combining several Assessment of Prior Learning methods and comparing the teachers’ assessments the teachers respond to the issues of validity and reliability. However, validity and reliability might be even further strengthened, if the competencies are well defined, if the education system is aware of securing a reasonable balance between knowing how, knowing that, and knowing why, and if the teachers are adequately trained for the assessment procedures.

  9. Sportmen’s experiences at a somatology clinic receiving a sport message

    Directory of Open Access Journals (Sweden)

    Karien Jooste

    2013-06-01

    Full Text Available Sportsmen are increasingly visiting somatology clinics for massages prior to an aerobic sports event. Massage is frequently utilised prior to an athletic activity, as a means of enhancing performance. Massage is known to have both calming and stimulating properties, thereby possessing the potential to benefit performance in numerous different circumstances. In the context of sportsmen visiting somatology clinics, it is unclear how men experienced the benefits of a massage by a therapist in the somatology environment, prior to participating in an aerobic sports event. The purpose of this qualitative, exploratory, descriptive and contextual study was to explore and describe the experiences of men regarding sports massage in a somatology clinic prior to an aerobic sports event. Purposive sampling was used to select eight (8 men, aged between 25 and 50 years, who received two massages within two weeks prior to participating in an aerobic sports event. The data were collected through in-depth, unstructured, individual interviews and field notes until saturation of data was achieved. Trustworthiness was ensured by utilising the principles of Lincoln and Guba’s model. The men experienced the sports massage as relaxing and giving perceived holistic beneficial effects. They described their experience during the massage and during and after participation in an aerobic sports event. A sports massage brings about psychological, physical, and spiritual effects during and after participation in an aerobic sports event. Sportsmanne besoek toenemend somatologieklinieke vir masserings voor ’n aërobiese sportsbyeenkoms as ’n manier om prestasie te bevorder. Massering is bekend vir beide die kalmerende en stimulerende eienskappe daarvan, en daarom beskik dit oor potensiële voordele vir prestasie in verskeie omstandighede. In die konteks van sportsmanne wat somatologieklinieke besoek, is dit steeds onduidelik hoe mans die voordele van ’n massering by

  10. Validity in assessment of prior learning

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    2015-01-01

    , the article discusses the need for specific criteria for assessment. The reliability and validity of the assessment procedures depend on whether the competences are well-defined, and whether the teachers are adequately trained for the assessment procedures. Keywords: assessment, prior learning, adult...... education, vocational training, lifelong learning, validity...

  11. Prior authorisation schemes: trade barriers in need of scientific justification

    NARCIS (Netherlands)

    Meulen, van der B.M.J.

    2010-01-01

    Case C-333/08 Commission v. French Republic ‘processing aids’ [2010] ECR-0000 French prior authorisation scheme for processing aids in food production infringes upon Article 34 TFEU** 1. A prior authorisation scheme not complying with the principle of proportionality, infringes upon Article 34 TFEU.

  12. Problems of radiotherapy on the brain tumors in children less than two years of age

    Energy Technology Data Exchange (ETDEWEB)

    Miyagami, Mitsusuke; Tsubokawa, Takashi (Nihon Univ., Tokyo (Japan). School of Medicine); Nishimoto, Hiroshi; Ueno, Yuhichi

    1990-06-01

    Impaired growth and mental or developmental disturbance due to radiotherapy for 10 cases of brain tumors in the children ages less than 2 years old were evaluated. Six cases of brain tumor which did not involve the hypothalamic-pituitary axis, were followed more than 2 years after cranial or craniospinal irradiation. Four cases irradiated greater than 2900 rad to the whole brain all revealed markedly lower body heights than -2 SD of the medium. Growth impairment was found to be progressive over time, and markedly evident after 2 years following cranial or craniospinal radiotherapy. Somatomedin C in the blood was measured in 8 cases of brain tumors in childhood receiving radiotherapy. The measurement of Somatomedin C showed markedly low values measuring 0.19 to 0.54 U/ml (medium; 0.36 U/ml) in children having lower body height than -2 SD. Mental retardation or developmental disturbances were found in IQ or DQ tests in all of 5 infants or children younger than 2 years with brain tumors who got radiotherapy over 2900 rad to the whole brain. A case of craniopharyngioma, which had 5400 rad for tumor localization at the hypothalamus-pituitary axis and showed markedly low height, was given growth hormone and grew to normal height without distinct side effects. It was suggested that radiotherapy for brain tumors in infants or children should have special care in deciding the dose, field and time of radiation. If low height due to radiotherapy results, growth hormone therapy should be used for its treatment in childhood. (author).

  13. The stability of a terahertz receiver based on a superconducting integrated receiver

    International Nuclear Information System (INIS)

    Ozhegov, R V; Gorshkov, K N; Gol'tsman, G N; Kinev, N V; Koshelets, V P

    2011-01-01

    We present the results of stability testing of a terahertz radiometer based on a superconducting receiver with a SIS tunnel junction as the mixer and a flux-flow oscillator as the local oscillator. In the continuum mode, the receiver with a noise temperature of 95 K at 510 GHz measured over the intermediate frequency (IF) passband of 4-8 GHz offered a noise equivalent temperature difference of 10 ± 1 mK at an integration time of 1 s. We offer a method to significantly increase the integration time without the use of complex measurement equipment. The receiver observed a strong signal over a final detection bandwidth of 4 GHz and offered an Allan time of 5 s.

  14. The stability of a terahertz receiver based on a superconducting integrated receiver

    Energy Technology Data Exchange (ETDEWEB)

    Ozhegov, R V; Gorshkov, K N; Gol' tsman, G N [Department of Physics, Moscow State Pedagogical University, Moscow 119992 (Russian Federation); Kinev, N V; Koshelets, V P, E-mail: Ozhegov@rplab.ru [Institute of Radio Engineering and Electronics, 125009 Moscow (Russian Federation)

    2011-03-15

    We present the results of stability testing of a terahertz radiometer based on a superconducting receiver with a SIS tunnel junction as the mixer and a flux-flow oscillator as the local oscillator. In the continuum mode, the receiver with a noise temperature of 95 K at 510 GHz measured over the intermediate frequency (IF) passband of 4-8 GHz offered a noise equivalent temperature difference of 10 {+-} 1 mK at an integration time of 1 s. We offer a method to significantly increase the integration time without the use of complex measurement equipment. The receiver observed a strong signal over a final detection bandwidth of 4 GHz and offered an Allan time of 5 s.

  15. Generalized species sampling priors with latent Beta reinforcements

    Science.gov (United States)

    Airoldi, Edoardo M.; Costa, Thiago; Bassetti, Federico; Leisen, Fabrizio; Guindani, Michele

    2014-01-01

    Many popular Bayesian nonparametric priors can be characterized in terms of exchangeable species sampling sequences. However, in some applications, exchangeability may not be appropriate. We introduce a novel and probabilistically coherent family of non-exchangeable species sampling sequences characterized by a tractable predictive probability function with weights driven by a sequence of independent Beta random variables. We compare their theoretical clustering properties with those of the Dirichlet Process and the two parameters Poisson-Dirichlet process. The proposed construction provides a complete characterization of the joint process, differently from existing work. We then propose the use of such process as prior distribution in a hierarchical Bayes modeling framework, and we describe a Markov Chain Monte Carlo sampler for posterior inference. We evaluate the performance of the prior and the robustness of the resulting inference in a simulation study, providing a comparison with popular Dirichlet Processes mixtures and Hidden Markov Models. Finally, we develop an application to the detection of chromosomal aberrations in breast cancer by leveraging array CGH data. PMID:25870462

  16. Natural priors, CMSSM fits and LHC weather forecasts

    International Nuclear Information System (INIS)

    Allanach, Benjamin C.; Cranmer, Kyle; Lester, Christopher G.; Weber, Arne M.

    2007-01-01

    Previous LHC forecasts for the constrained minimal supersymmetric standard model (CMSSM), based on current astrophysical and laboratory measurements, have used priors that are flat in the parameter tan β, while being constrained to postdict the central experimental value of M Z . We construct a different, new and more natural prior with a measure in μ and B (the more fundamental MSSM parameters from which tan β and M Z are actually derived). We find that as a consequence this choice leads to a well defined fine-tuning measure in the parameter space. We investigate the effect of such on global CMSSM fits to indirect constraints, providing posterior probability distributions for Large Hadron Collider (LHC) sparticle production cross sections. The change in priors has a significant effect, strongly suppressing the pseudoscalar Higgs boson dark matter annihilation region, and diminishing the probable values of sparticle masses. We also show how to interpret fit information from a Markov Chain Monte Carlo in a frequentist fashion; namely by using the profile likelihood. Bayesian and frequentist interpretations of CMSSM fits are compared and contrasted

  17. Ground receiving station (GRS) of UMS - receiving and processing the electromagnetic wave data from satellite

    International Nuclear Information System (INIS)

    Mohammad Syahmi Nordin; Fauziah Abdul Aziz

    2007-01-01

    The low resolution Automatic Picture Transmission (APT) data from the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites Advanced Very High Resolution Radiometer (AVHRR) is being received and recorded in real-time mode at ground receiving station in School of Science and Technology, Universiti Malaysia Sabah. The system is suitable for the developing and undeveloped countries in south and Southeast Asia and is said to be acceptable for engineering, agricultural, climatological and environmental applications. The system comprises a personal computer attached with a small APT receiver. The data transmission between the ground receiving station and NOAA satellites is using the electromagnetic wave. The relation for receiving and processing the electromagnetic wave in the transmission will be discussed. (Author)

  18. Clinical effects of prior trastuzumab on combination eribulin mesylate plus trastuzumab as first-line treatment for human epidermal growth factor receptor 2 positive locally recurrent or metastatic breast cancer: results from a Phase II, single-arm, multicenter study

    Directory of Open Access Journals (Sweden)

    Puhalla S

    2016-12-01

    Full Text Available Shannon Puhalla,1 Sharon Wilks,2 Adam M Brufsky,1 Joyce O’Shaughnessy,3 Lee S Schwartzberg,4 Erhan Berrak,5 James Song,5 Linda Vahdat6 1Department of Hematology and Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA, 2Department of Hematology Oncology, US Oncology-Cancer Care Centers of South Texas, San Antonio, TX, 3Department of Medical Oncology, Texas Oncology-Baylor Charles A. Sammons Cancer Center US Oncology, Dallas, TX, 4Department of Hematology/Oncology, West Cancer Center, University of Tennessee Health Science Center, Memphis, TN, 5Department of Medical Affairs, Formerly of Eisai Inc., Woodcliff Lake, NJ, 6Department of Medicine, Weill Cornell Medical College, New York, NY, USA Abstract: Eribulin mesylate, a novel nontaxane microtubule dynamics inhibitor in the halichondrin class of antineoplastic drugs, is indicated for the treatment of patients with metastatic breast cancer who previously received ≥2 chemotherapy regimens in the metastatic setting. Primary data from a Phase II trial for the first-line combination of ­eribulin plus trastuzumab in human epidermal growth factor receptor 2 positive patients showed a 71% objective response rate and tolerability consistent with the known profile of these agents. Here, we present prespecified analyses of efficacy of this combination based on prior trastuzumab use. Patients received eribulin mesylate 1.4 mg/m2 (equivalent to 1.23 mg/m2 eribulin [expressed as free base] intravenously on days 1 and 8 plus trastuzumab (8 mg/kg intravenously/cycle 1, then 6 mg/kg on day 1 of each 21-day cycle. Objective response rates, progression-free survival, and tolerability were assessed in patients who had and had not received prior adjuvant or neoadjuvant (neo/adjuvant trastuzumab treatment. Fifty-two patients (median age: 59.5 years received eribulin/trastuzumab for a median treatment duration of ~31 weeks; 40.4% (n=21 had been previously treated with neo/adjuvant trastuzumab prior to

  19. Neutrino masses and their ordering: global data, priors and models

    Science.gov (United States)

    Gariazzo, S.; Archidiacono, M.; de Salas, P. F.; Mena, O.; Ternes, C. A.; Tórtola, M.

    2018-03-01

    We present a full Bayesian analysis of the combination of current neutrino oscillation, neutrinoless double beta decay and Cosmic Microwave Background observations. Our major goal is to carefully investigate the possibility to single out one neutrino mass ordering, namely Normal Ordering or Inverted Ordering, with current data. Two possible parametrizations (three neutrino masses versus the lightest neutrino mass plus the two oscillation mass splittings) and priors (linear versus logarithmic) are exhaustively examined. We find that the preference for NO is only driven by neutrino oscillation data. Moreover, the values of the Bayes factor indicate that the evidence for NO is strong only when the scan is performed over the three neutrino masses with logarithmic priors; for every other combination of parameterization and prior, the preference for NO is only weak. As a by-product of our Bayesian analyses, we are able to (a) compare the Bayesian bounds on the neutrino mixing parameters to those obtained by means of frequentist approaches, finding a very good agreement; (b) determine that the lightest neutrino mass plus the two mass splittings parametrization, motivated by the physical observables, is strongly preferred over the three neutrino mass eigenstates scan and (c) find that logarithmic priors guarantee a weakly-to-moderately more efficient sampling of the parameter space. These results establish the optimal strategy to successfully explore the neutrino parameter space, based on the use of the oscillation mass splittings and a logarithmic prior on the lightest neutrino mass, when combining neutrino oscillation data with cosmology and neutrinoless double beta decay. We also show that the limits on the total neutrino mass ∑ mν can change dramatically when moving from one prior to the other. These results have profound implications for future studies on the neutrino mass ordering, as they crucially state the need for self-consistent analyses which explore the

  20. Estimation and analysis of the short-term variations of multi-GNSS receiver differential code biases using global ionosphere maps

    Science.gov (United States)

    Li, Min; Yuan, Yunbin; Wang, Ningbo; Liu, Teng; Chen, Yongchang

    2017-12-01

    -term intervals should be finished prior to estimate daily multi-GNSS receiver DCB products.

  1. Ibrutinib for chronic graft-versus-host disease after failure of prior therapy.

    Science.gov (United States)

    Miklos, David; Cutler, Corey S; Arora, Mukta; Waller, Edmund K; Jagasia, Madan; Pusic, Iskra; Flowers, Mary E; Logan, Aaron C; Nakamura, Ryotaro; Blazar, Bruce R; Li, Yunfeng; Chang, Stephen; Lal, Indu; Dubovsky, Jason; James, Danelle F; Styles, Lori; Jaglowski, Samantha

    2017-11-23

    Chronic graft-versus-host disease (cGVHD) is a serious complication of allogeneic stem cell transplantation with few effective options available after failure of corticosteroids. B and T cells play a role in the pathophysiology of cGVHD. Ibrutinib inhibits Bruton tyrosine kinase in B cells and interleukin-2-inducible T-cell kinase in T cells. In preclinical models, ibrutinib reduced severity of cGVHD. This multicenter, open-label study evaluated the safety and efficacy of ibrutinib in patients with active cGVHD with inadequate response to corticosteroid-containing therapies. Forty-two patients who had failed 1 to 3 prior treatments received ibrutinib (420 mg) daily until cGVHD progression. The primary efficacy end point was cGVHD response based on 2005 National Institutes of Health criteria. At a median follow-up of 13.9 months, best overall response was 67%; 71% of responders showed a sustained response for ≥20 weeks. Responses were observed across involved organs evaluated. Most patients with multiple cGVHD organ involvement had a multiorgan response. Median corticosteroid dose in responders decreased from 0.29 mg/kg per day at baseline to 0.12 mg/kg per day at week 49; 5 responders discontinued corticosteroids. The most common adverse events were fatigue, diarrhea, muscle spasms, nausea, and bruising. Plasma levels of soluble factors associated with inflammation, fibrosis, and cGVHD significantly decreased over time with ibrutinib. Ibrutinib resulted in clinically meaningful responses with acceptable safety in patients with ≥1 prior treatments for cGVHD. Based on these results, ibrutinib was approved in the United States for treatment of adult patients with cGVHD after failure of 1 or more lines of systemic therapy. This trial was registered at www.clinicaltrials.gov as #NCT02195869. © 2017 by The American Society of Hematology.

  2. Prior Authorization of PMDs Demonstration - Status Update

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS implemented a Prior Authorization process for scooters and power wheelchairs for people with Fee-For-Service Medicare who reside in seven states with high...

  3. Short Report Biochemical derangements prior to emergency ...

    African Journals Online (AJOL)

    MMJ VOL 29 (1): March 2017. Biochemical derangements prior to emergency laparotomy at QECH 55. Malawi Medical Journal 29 (1): March 2017 ... Venepuncture was performed preoperatively for urgent cases, defined as those requiring.

  4. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  5. 29 CFR 553.23 - Agreement or understanding prior to performance of work.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Agreement or understanding prior to performance of work... understanding prior to performance of work. (a) General. (1) As a condition for use of compensatory time in lieu... reached prior to the performance of work. This can be accomplished pursuant to a collective bargaining...

  6. 7 CFR 4290.480 - Prior approval of changes to RBIC's business plan.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Prior approval of changes to RBIC's business plan... § 4290.480 Prior approval of changes to RBIC's business plan. Without the Secretary's prior written approval, no change in your business plan, upon which you were selected and licensed as a RBIC, may take...

  7. Drunkorexia: Calorie Restriction Prior to Alcohol Consumption among College Freshman

    Science.gov (United States)

    Burke, Sloane C.; Cremeens, Jennifer; Vail-Smith, Karen; Woolsey, Conrad

    2010-01-01

    Using a sample of 692 freshmen at a southeastern university, this study examined caloric restriction among students prior to planned alcohol consumption. Participants were surveyed for self-reported alcohol consumption, binge drinking, and caloric intake habits prior to drinking episodes. Results indicated that 99 of 695 (14%) of first year…

  8. Wideband CMOS receivers

    CERN Document Server

    Oliveira, Luis

    2015-01-01

    This book demonstrates how to design a wideband receiver operating in current mode, in which the noise and non-linearity are reduced, implemented in a low cost single chip, using standard CMOS technology.  The authors present a solution to remove the transimpedance amplifier (TIA) block and connect directly the mixer’s output to a passive second-order continuous-time Σ∆ analog to digital converter (ADC), which operates in current-mode. These techniques enable the reduction of area, power consumption, and cost in modern CMOS receivers.

  9. HIGH-EFFICIENCY INFRARED RECEIVER

    Directory of Open Access Journals (Sweden)

    A. K. Esman

    2016-01-01

    Full Text Available Recent research and development show promising use of high-performance solid-state receivers of the electromagnetic radiation. These receivers are based on the low-barrier Schottky diodes. The approach to the design of the receivers on the basis of delta-doped low-barrier Schottky diodes with beam leads without bias is especially actively developing because for uncooled receivers of the microwave radiation these diodes have virtually no competition. The purpose of this work is to improve the main parameters and characteristics that determine the practical relevance of the receivers of mid-infrared electromagnetic radiation at the operating room temperature by modifying the electrodes configuration of the diode and optimizing the distance between them. Proposed original design solution of the integrated receiver of mid-infrared radiation on the basis of the low-barrier Schottky diodes with beam leads allows to effectively adjust its main parameters and characteristics. Simulation of the electromagnetic characteristics of the proposed receiver by using the software package HFSS with the basic algorithm of a finite element method which implemented to calculate the behavior of electromagnetic fields on an arbitrary geometry with a predetermined material properties have shown that when the inner parts of the electrodes of the low-barrier Schottky diode is performed in the concentric elliptical convex-concave shape, it can be reduce the reflection losses to -57.75 dB and the standing wave ratio to 1.003 while increasing the directivity up to 23 at a wavelength of 6.09 μm. At this time, the rounded radii of the inner parts of the anode and cathode electrodes are equal 212 nm and 318 nm respectively and the gap setting between them is 106 nm. These parameters will improve the efficiency of the developed infrared optical-promising and electronic equipment for various purposes intended for work in the mid-infrared wavelength range. 

  10. Anemia prevalence and treatment practice in patients with non-myeloid tumors receiving chemotherapy

    International Nuclear Information System (INIS)

    Merlini, Laura; Cartenì, Giacomo; Iacobelli, Stefano; Stelitano, Caterina; Airoldi, Mario; Balcke, Peter; Keil, Felix; Haslbauer, Ferdinand; Belton, Laura; Pujol, Beatriz

    2013-01-01

    To describe the prevalence and management of anemia in cancer patients. This cross-sectional, observational survey was conducted in Italy and Austria. Centers prespecified one day, during a 4-month enrollment window, to report specific data collected during normal clinical practice for patients with non-myeloid tumors attending for chemotherapy (±radiotherapy) treatment. The primary endpoint was the prevalence of anemia as determined using a prespecified algorithm: hemoglobin (Hb) ≤10 g/dL on/within 3 days prior to visit; ongoing anemia treatment; physician diagnosis of anemia, together with ≥1 anemia symptom. Between November 18, 2010 and March 18, 2011, data for 1412 patients were collected (Italy n = 1130; Austria n = 282). Most patients (n = 1136; 80%) had solid tumors; 809 (57%) had received ≤3 chemotherapy cycles. The prevalence of anemia was 32% (95% confidence interval: 29.4%–34.2%); 196 patients (14%) were deemed anemic based on Hb ≤10 g/dL, 131 (9%) on ongoing anemia treatment, and 121 (9%) on physician diagnosis/anemia symptom. Overall, 1153 patients (82%) had Hb data; mean (standard deviation [SD]) Hb levels were 11.7 (1.7) g/dL. In total, 456 patients (32%) had anemia symptoms: fatigue (n = 392; 28%), depression (n = 122; 9%), and dyspnea (n = 107; 8%) were most common. Fifty-one patients (4%) had had their current chemotherapy cycle delayed due to anemia. On visit day, or ≤28 days prior, 91 (6%), 188 (13%), and 81 patients (6%) had evidence of whole blood/red blood cell transfusion, erythropoiesis-stimulating agent use, or iron use, respectively. On the prespecified study day, one-third of patients with non-myeloid tumors undergoing chemotherapy were found to be anemic and 13% had evidence of erythropoiesis-stimulating agent use then or in the 28 days prior

  11. Prior knowledge processing for initial state of Kalman filter

    Czech Academy of Sciences Publication Activity Database

    Suzdaleva, Evgenia

    2010-01-01

    Roč. 24, č. 3 (2010), s. 188-202 ISSN 0890-6327 R&D Projects: GA ČR(CZ) GP201/06/P434 Institutional research plan: CEZ:AV0Z10750506 Keywords : Kalman filtering * prior knowledge * state-space model * initial state distribution Subject RIV: BC - Control Systems Theory Impact factor: 0.729, year: 2010 http://library.utia.cas.cz/separaty/2009/AS/suzdaleva-prior knowledge processing for initial state of kalman filter.pdf

  12. Avoiding the known prior acts exclusion when insuring newly acquired entities.

    Science.gov (United States)

    Gasior, J P; Passannante, W G

    1998-09-01

    Adding a new entity to an organization's existing insurance program can be problematic if the existing policy contains a known prior acts exclusion clause. By purportedly excluding claims that a policyholder "could have reasonably foreseen or discovered," the known prior acts exclusion allows the insurer to reject those claims after a lawsuit has been filed policyholders should have known prior acts exclusion clauses removed from their policies or work with their insurers on language that will clarify the policy regarding this exclusion.

  13. Apples and oranges: avoiding different priors in Bayesian DNA sequence analysis

    Directory of Open Access Journals (Sweden)

    Posch Stefan

    2010-03-01

    Full Text Available Abstract Background One of the challenges of bioinformatics remains the recognition of short signal sequences in genomic DNA such as donor or acceptor splice sites, splicing enhancers or silencers, translation initiation sites, transcription start sites, transcription factor binding sites, nucleosome binding sites, miRNA binding sites, or insulator binding sites. During the last decade, a wealth of algorithms for the recognition of such DNA sequences has been developed and compared with the goal of improving their performance and to deepen our understanding of the underlying cellular processes. Most of these algorithms are based on statistical models belonging to the family of Markov random fields such as position weight matrix models, weight array matrix models, Markov models of higher order, or moral Bayesian networks. While in many comparative studies different learning principles or different statistical models have been compared, the influence of choosing different prior distributions for the model parameters when using different learning principles has been overlooked, and possibly lead to questionable conclusions. Results With the goal of allowing direct comparisons of different learning principles for models from the family of Markov random fields based on the same a-priori information, we derive a generalization of the commonly-used product-Dirichlet prior. We find that the derived prior behaves like a Gaussian prior close to the maximum and like a Laplace prior in the far tails. In two case studies, we illustrate the utility of the derived prior for a direct comparison of different learning principles with different models for the recognition of binding sites of the transcription factor Sp1 and human donor splice sites. Conclusions We find that comparisons of different learning principles using the same a-priori information can lead to conclusions different from those of previous studies in which the effect resulting from different

  14. Epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge in Japan: An exploratory descriptive study using a nationwide claims database.

    Science.gov (United States)

    Okumura, Yasuyuki; Sakata, Nobuo; Takahashi, Kunihiko; Nishi, Daisuke; Tachimori, Hisateru

    2017-08-01

    Little is known about the nationwide epidemiology of the annual rate, causative substance, and clinical course of overdose-related admission. We aimed to describe the epidemiology of overdose episodes from the period prior to hospitalization for drug poisoning until discharge to home. We assessed all cases of admission due to overdose (21,663 episodes) in Japan from October 2012 through September 2013 using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. The annual rate of overdose admission was 17.0 per 100,000 population. Women exhibited two peaks in admission rates at 19-34 years (40.9 per 100,000) and ≥75 years (27.8 per 100,000). Men exhibited one peak in the admission rate at ≥75 years (23.7 per 100,000). Within 90 days prior to overdose, ≥60% and ≥9% of patients aged 19-49 years received a prescription for benzodiazepines and barbiturates, respectively. In addition, 59% of patients aged ≥75 years received a prescription for benzodiazepines prior to overdose, 47% had a history of congestive heart failure, and 24% had a diagnosis of poisoning by cardiovascular drugs. The proportion of patients with recent psychiatric treatments decreased with age (65.1% in those aged 35-49 years and 13.9% in those aged ≥75 years). The findings emphasize the need for overdose prevention programs that focus on psychiatric patients aged 19-49 years who are prescribed benzodiazepines or barbiturates and on non-psychiatric patients aged ≥75 years who are prescribed benzodiazepines or digitalis. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  15. Satellite Infrared Radiation Measurements Prior to the Major Earthquakes

    Science.gov (United States)

    Ouzounov, Dimitar; Pulintes, S.; Bryant, N.; Taylor, Patrick; Freund, F.

    2005-01-01

    This work describes our search for a relationship between tectonic stresses and increases in mid-infrared (IR) flux as part of a possible ensemble of electromagnetic (EM) phenomena that may be related to earthquake activity. We present and &scuss observed variations in thermal transients and radiation fields prior to the earthquakes of Jan 22, 2003 Colima (M6.7) Mexico, Sept. 28 .2004 near Parkfield (M6.0) in California and Northern Sumatra (M8.5) Dec. 26,2004. Previous analysis of earthquake events has indicated the presence of an IR anomaly, where temperatures increased or did not return to its usual nighttime value. Our procedures analyze nighttime satellite data that records the general condtion of the ground after sunset. We have found from the MODIS instrument data that five days before the Colima earthquake the IR land surface nighttime temperature rose up to +4 degrees C in a 100 km radius around the epicenter. The IR transient field recorded by MODIS in the vicinity of Parkfield, also with a cloud free environment, was around +1 degree C and is significantly smaller than the IR anomaly around the Colima epicenter. Ground surface temperatures near the Parkfield epicenter four days prior to the earthquake show steady increase. However, on the night preceding the quake, a significant drop in relative humidity was indicated, process similar to those register prior to the Colima event. Recent analyses of continuous ongoing long- wavelength Earth radiation (OLR) indicate significant and anomalous variability prior to some earthquakes. The cause of these anomalies is not well understood but could be the result of a triggering by an interaction between the lithosphere-hydrosphere and atmospheric related to changes in the near surface electrical field and/or gas composition prior to the earthquake. The OLR anomaly usually covers large areas surrounding the main epicenter. We have found strong anomalies signal (two sigma) along the epicentral area signals on Dec 21

  16. More Efficient Solar Thermal-Energy Receiver

    Science.gov (United States)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  17. 29 CFR 452.40 - Prior office holding.

    Science.gov (United States)

    2010-07-01

    ... DISCLOSURE ACT OF 1959 Candidacy for Office; Reasonable Qualifications § 452.40 Prior office holding. A.... 26 26 Wirtz v. Hotel, Motel and Club Employees Union, Local 6, 391 U.S. 492 at 504. The Court stated...

  18. Evaluation of the macula prior to cataract surgery.

    Science.gov (United States)

    McKeague, Marta; Sharma, Priya; Ho, Allen C

    2018-01-01

    To describe recent evidence regarding methods of evaluation of retinal structure and function prior to cataract surgery. Studies in patients with cataract but no clinically detectable retinal disease have shown that routine use of optical coherence tomography (OCT) prior to cataract surgery can detect subtle macular disease, which may alter the course of treatment or lead to modification of consent. The routine use of OCT has been especially useful in patients being considered for advanced-technology intraocular lenses (IOLs) as subtle macular disease can be a contraindication to the use of these lenses. The cost-effectiveness of routine use of OCT prior to cataract surgery has not been studied. Other technologies that assess retinal function rather than structure, such as microperimetry and electroretinogram (ERG) need further study to determine whether they can predict retinal potential in cataract patients. There is growing evidence for the importance of more detailed retinal evaluation of cataract patients even with clinically normal exam. OCT has been the most established and studied method for retinal evaluation in cataract patients, but other technologies such as microperimetry and ERG are beginning to be studied.

  19. Use of Piggyback Electrolytes for Patients Receiving Individually Prescribed vs Premixed Parenteral Nutrition.

    Science.gov (United States)

    Busch, Rebecca A; Curtis, Caitlin S; Leverson, Glen E; Kudsk, Kenneth A

    2015-07-01

    Parenteral nutrition (PN) is available as individualized prescriptions frequently prepared with an automated compounding device or as commercially prepared premixed solutions. Our institution exclusively used individualized PN until an amino acid shortage forced a temporary switch to premixed solutions. In general, premixed solutions contain lower electrolyte levels than individualized formulations prescribed for patients with normal organ function. We aimed to quantify supplemental intravenous piggyback (IVPB) electrolyte use in adult patients receiving individualized and premixed PN and to quantify any effect on difference in the cost of therapy. We compared use of supplemental IVPB electrolytes administered to patients receiving PN during consecutive periods prior to and during the amino acid shortage. Electrolyte IVPBs tabulated were potassium chloride, 10 and 20 mEq; magnesium sulfate, 2 g and 4 g; potassium phosphate, 7.5 and 15 mmol; and sodium phosphate, 7.5 and 15 mmol IVPB. There was no statistical difference in the number of PN formulations administered per day during each period (14.7 ± 3.9 vs 14.0 ± 2.6, individualized vs premixed, respectively). Total IVPB electrolytes prescribed per day increased significantly from the individualized PN period to the premixed PN period (7.03 ± 3.8 vs 13.8 ± 6.8; P Parenteral and Enteral Nutrition.

  20. Clinical utility of carotid duplex ultrasound prior to cardiac surgery.

    Science.gov (United States)

    Lin, Judith C; Kabbani, Loay S; Peterson, Edward L; Masabni, Khalil; Morgan, Jeffrey A; Brooks, Sara; Wertella, Kathleen P; Paone, Gaetano

    2016-03-01

    Clinical utility and cost-effectiveness of carotid duplex examination prior to cardiac surgery have been questioned by the multidisciplinary committee creating the 2012 Appropriate Use Criteria for Peripheral Vascular Laboratory Testing. We report the clinical outcomes and postoperative neurologic symptoms in patients who underwent carotid duplex ultrasound prior to open heart surgery at a tertiary institution. Using the combined databases from our clinical vascular laboratory and the Society of Thoracic Surgery, a retrospective analysis of all patients who underwent carotid duplex ultrasound within 13 months prior to open heart surgery from March 2005 to March 2013 was performed. The outcomes between those who underwent carotid duplex scanning (group A) and those who did not (group B) were compared. Among 3233 patients in the cohort who underwent cardiac surgery, 515 (15.9%) patients underwent a carotid duplex ultrasound preoperatively, and 2718 patients did not (84.1%). Among the patients who underwent carotid screening vs no screening, there was no statistically significant difference in the risk factors of cerebrovascular disease (10.9% vs 12.7%; P = .26), prior stroke (8.2% vs 7.2%; P = .41), and prior transient ischemic attack (2.9% vs 3.3%; P = .24). For those undergoing isolated coronary artery bypass grafting (CABG), 306 (17.8%) of 1723 patients underwent preoperative carotid duplex ultrasound. Among patients who had carotid screening prior to CABG, the incidence of carotid disease was low: 249 (81.4%) had minimal or mild stenosis (duplex scanning and those who did not. Primary outcomes of patients who underwent open heart surgery also showed no difference in the perioperative mortality (5.1% vs 6.9%; P = .14) and stroke (2.6% vs 2.4%; P = .85) between patients undergoing preoperative duplex scanning and those who did not. Operative intervention of severe carotid stenosis prior to isolated CABG occurred in 2 of the 17 patients (11.8%) identified who

  1. An Adaptively Accelerated Bayesian Deblurring Method with Entropy Prior

    Directory of Open Access Journals (Sweden)

    Yong-Hoon Kim

    2008-05-01

    Full Text Available The development of an efficient adaptively accelerated iterative deblurring algorithm based on Bayesian statistical concept has been reported. Entropy of an image has been used as a “prior” distribution and instead of additive form, used in conventional acceleration methods an exponent form of relaxation constant has been used for acceleration. Thus the proposed method is called hereafter as adaptively accelerated maximum a posteriori with entropy prior (AAMAPE. Based on empirical observations in different experiments, the exponent is computed adaptively using first-order derivatives of the deblurred image from previous two iterations. This exponent improves speed of the AAMAPE method in early stages and ensures stability at later stages of iteration. In AAMAPE method, we also consider the constraint of the nonnegativity and flux conservation. The paper discusses the fundamental idea of the Bayesian image deblurring with the use of entropy as prior, and the analytical analysis of superresolution and the noise amplification characteristics of the proposed method. The experimental results show that the proposed AAMAPE method gives lower RMSE and higher SNR in 44% lesser iterations as compared to nonaccelerated maximum a posteriori with entropy prior (MAPE method. Moreover, AAMAPE followed by wavelet wiener filtering gives better result than the state-of-the-art methods.

  2. Comparison of Attitudes Toward Death Between University Students Who Receive Nursing Education and Who Receive Religious Education.

    Science.gov (United States)

    Bakan, Ayse Berivan; Arli, Senay Karadag

    2018-03-22

    This study aims to compare attitudes toward death between university students who receive nursing education and who receive religious education. This study is cross-sectional in nature. It was conducted with the participation of 197 university students in a university located in the Eastern part of Turkey between June and August, 2017. Data were collected using the socio-demographic form and Turkish form of Death Attitudes Profile-Revised. Of all the students participating in the study, 52.8% received nursing education and 47.2% received religious education. It was found that majority of both groups had no education about death, or found the education they received insufficient. Besides, no significant differences were found between the students who received nursing education and who received religious education in terms of their attitudes toward death (p > 0.05). Results showed that students who received nursing education and who received religious education had similar attitudes toward death. In conclusion, the education given to students about the religious or health aspects of death in accordance with the curriculum seemed to have no effects on students' developing positive attitudes toward death.

  3. Modeling and validating Bayesian accrual models on clinical data and simulations using adaptive priors.

    Science.gov (United States)

    Jiang, Yu; Simon, Steve; Mayo, Matthew S; Gajewski, Byron J

    2015-02-20

    Slow recruitment in clinical trials leads to increased costs and resource utilization, which includes both the clinic staff and patient volunteers. Careful planning and monitoring of the accrual process can prevent the unnecessary loss of these resources. We propose two hierarchical extensions to the existing Bayesian constant accrual model: the accelerated prior and the hedging prior. The new proposed priors are able to adaptively utilize the researcher's previous experience and current accrual data to produce the estimation of trial completion time. The performance of these models, including prediction precision, coverage probability, and correct decision-making ability, is evaluated using actual studies from our cancer center and simulation. The results showed that a constant accrual model with strongly informative priors is very accurate when accrual is on target or slightly off, producing smaller mean squared error, high percentage of coverage, and a high number of correct decisions as to whether or not continue the trial, but it is strongly biased when off target. Flat or weakly informative priors provide protection against an off target prior but are less efficient when the accrual is on target. The accelerated prior performs similar to a strong prior. The hedging prior performs much like the weak priors when the accrual is extremely off target but closer to the strong priors when the accrual is on target or only slightly off target. We suggest improvements in these models and propose new models for future research. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Inhibition of vicariously learned fear in children using positive modeling and prior exposure.

    Science.gov (United States)

    Askew, Chris; Reynolds, Gemma; Fielding-Smith, Sarah; Field, Andy P

    2016-02-01

    One of the challenges to conditioning models of fear acquisition is to explain how different individuals can experience similar learning events and only some of them subsequently develop fear. Understanding factors moderating the impact of learning events on fear acquisition is key to understanding the etiology and prevention of fear in childhood. This study investigates these moderators in the context of vicarious (observational) learning. Two experiments tested predictions that the acquisition or inhibition of fear via vicarious learning is driven by associative learning mechanisms similar to direct conditioning. In Experiment 1, 3 groups of children aged 7 to 9 years received 1 of 3 inhibitive information interventions-psychoeducation, factual information, or no information (control)-prior to taking part in a vicarious fear learning procedure. In Experiment 2, 3 groups of children aged 7 to 10 years received 1 of 3 observational learning interventions-positive modeling (immunization), observational familiarity (latent inhibition), or no prevention (control)-before vicarious fear learning. Results indicated that observationally delivered manipulations inhibited vicarious fear learning, while preventions presented via written information did not. These findings confirm that vicarious learning shares some of the characteristics of direct conditioning and can explain why not all individuals will develop fear following a vicarious learning event. They also suggest that the modality of inhibitive learning is important and should match the fear learning pathway for increased chances of inhibition. Finally, the results demonstrate that positive modeling is likely to be a particularly effective method for preventing fear-related observational learning in children. (c) 2016 APA, all rights reserved).

  5. Evaluation of cognitive function in patients with limited small cell lung cancer prior to and shortly following prophylactic cranial irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Komaki, Ritsuko; Meyers, Christina A; Shin, Dong M; Garden, Adam S; Byrne, Kevin; Nickens, Judy A; Cox, James D

    1995-08-30

    Purpose: Cognitive deficits after treatment for small cell lung cancer (SCLC) have been attributed to prophylactic cranial irradiation (PCI). A prospective study of neuropsychological function was undertaken to document the evolution and magnitude of neuropsychologic deficits. Methods and Materials: Thirty patients with limited stage SCLC who responded well (29 complete response (CR), 1 partial response (PR)) to combination chemotherapy plus thoracic irradiation or resection were studied with neuropsychological tests in the cognitive domains of intelligence, frontal lobe function, language, memory, visual-perception, and motor dexterity prior to a planned course of PCI. Nine patients had a neurologic history that could influence testing. Results: An unexpected 97% (29 out of 30) of patients had evidence of cognitive dysfunction prior to PCI. The most frequent impairment was verbal memory, followed by frontal lobe dysfunction, and fine motor incoordination. Of the patients with no prior neurologic or substance abuse history, 20 out of 21 (95%) had impairments on neuropsychological assessment. This neurologically normal group was just as impaired as the group with such a history with respect to delayed verbal memory and frontal lobe executive function. Eleven patients had neuropsychological testing 6 to 20 months after PCI; no significant differences were found from their pretreatment tests. Conclusions: A high proportion of neurologically normal patients with limited SCLC and favorable responses to combination chemotherapy have specific cognitive deficits before receiving PCI. Short-term (6 to 20 months) observations after PCI have shown no significant deterioration.

  6. Evaluation of cognitive function in patients with limited small cell lung cancer prior to and shortly following prophylactic cranial irradiation

    International Nuclear Information System (INIS)

    Komaki, Ritsuko; Meyers, Christina A.; Shin, Dong M.; Garden, Adam S.; Byrne, Kevin; Nickens, Judy A.; Cox, James D.

    1995-01-01

    Purpose: Cognitive deficits after treatment for small cell lung cancer (SCLC) have been attributed to prophylactic cranial irradiation (PCI). A prospective study of neuropsychological function was undertaken to document the evolution and magnitude of neuropsychologic deficits. Methods and Materials: Thirty patients with limited stage SCLC who responded well (29 complete response (CR), 1 partial response (PR)) to combination chemotherapy plus thoracic irradiation or resection were studied with neuropsychological tests in the cognitive domains of intelligence, frontal lobe function, language, memory, visual-perception, and motor dexterity prior to a planned course of PCI. Nine patients had a neurologic history that could influence testing. Results: An unexpected 97% (29 out of 30) of patients had evidence of cognitive dysfunction prior to PCI. The most frequent impairment was verbal memory, followed by frontal lobe dysfunction, and fine motor incoordination. Of the patients with no prior neurologic or substance abuse history, 20 out of 21 (95%) had impairments on neuropsychological assessment. This neurologically normal group was just as impaired as the group with such a history with respect to delayed verbal memory and frontal lobe executive function. Eleven patients had neuropsychological testing 6 to 20 months after PCI; no significant differences were found from their pretreatment tests. Conclusions: A high proportion of neurologically normal patients with limited SCLC and favorable responses to combination chemotherapy have specific cognitive deficits before receiving PCI. Short-term (6 to 20 months) observations after PCI have shown no significant deterioration

  7. Receiver-exciter controller design

    Science.gov (United States)

    Jansma, P. A.

    1982-01-01

    A description of the general design of both the block 3 and block 4 receiver-exciter controllers for the Deep Space Network (DSN) Mark IV-A System is presented along with the design approach. The controllers are designed to enable the receiver-exciter subsystem (RCV) to be configured, calibrated, initialized and operated from a central location via high level instructions. The RECs are designed to be operated under the control of the DMC subsystem. The instructions are in the form of standard subsystem blocks (SSBs) received via the local area network (LAN). The centralized control provided by RECs and other DSCC controllers in Mark IV-A is intended to reduce DSN operations costs from the Mark III era.

  8. Distress among women receiving uninformative BRCA1/2 results: 12-month outcomes.

    Science.gov (United States)

    O'Neill, Suzanne C; Rini, Christine; Goldsmith, Rachel E; Valdimarsdottir, Heiddis; Cohen, Lawrence H; Schwartz, Marc D

    2009-10-01

    Few data are available regarding the long-term psychological impact of uninformative BRCA1/2 test results. This study examines change in distress from pretesting to 12-months post-disclosure, with medical, family history, and psychological variables, such as pretesting perceived risk of carrying a deleterious mutation prior to testing and primary and secondary appraisals, as predictors. Two hundred and nine women with uninformative BRCA1/2 test results completed questionnaires at pretesting and 1-, 6-, and 12-month post-disclosure, including measures of anxiety and depression, cancer-specific and genetic testing distress. We used a mixed models approach to predict change in post-disclosure distress. Distress declined from pretesting to 1-month post-disclosure, but remained stable thereafter. Primary appraisals predicted all types of distress at 1-month post-disclosure. Primary and secondary appraisals predicted genetic testing distress at 1-month as well as change over time. Receiving a variant of uncertain clinical significance and entering testing with a high expectation for carrying a deleterious mutation predicted genetic testing distress that persisted through the year after testing. As a whole, women receiving uninformative BRCA1/2 test results are a resilient group. For some women, distress experienced in the month after testing does not dissipate. Variables, such as heightened pretesting perceived risk and cognitive appraisals, predict greater likelihood for sustained distress in this group and could be amenable to intervention.

  9. Estimation of radiation dose received by the radiation workers during radiographic testing

    International Nuclear Information System (INIS)

    Mohammed, N. A. H. O.

    2013-08-01

    This study was conducted primarily to evaluate occupational radiation dose in industrial radiography during radiographic testing at Balil-Hadida, with the aim of building up baseline data on radiation exposure in the industrial radiography practice in Sudan. Dose measurements during radiographic testing were performed and compared with IAEA reference dose. In this research the doses measured by using hand held radiation survey meter and personal monitoring dosimeter. The results showed that radiation doses ranged between minimum (0.448 mSv/ 3 month) , and maximum (1.838 mSv / 3 month), with an average value (0.778 mSv/ 3 month), and the standard deviation 0.292 for the workers used gamma mat camera. The analysis of data showed that the radiation dose for all radiation worker are receives less than annual limit for exposed workers 20 mSv/ year and compare with other study found that the dose received while body doses ranging from 0.1 to 9.4 mSv/ year, work area design in all the radiography site followed the three standard rules namely putting radiation signs, reducing access to control area and making of boundaries. Thus the accidents arising from design faults not likely to occur at these site. Results suggest that adequate fundamental training of radiation workers in general radiography prior to industrial radiography work will further improve the standard of personnel radiation protection. (Author)

  10. Effects of prior information on decoding degraded speech: an fMRI study.

    Science.gov (United States)

    Clos, Mareike; Langner, Robert; Meyer, Martin; Oechslin, Mathias S; Zilles, Karl; Eickhoff, Simon B

    2014-01-01

    Expectations and prior knowledge are thought to support the perceptual analysis of incoming sensory stimuli, as proposed by the predictive-coding framework. The current fMRI study investigated the effect of prior information on brain activity during the decoding of degraded speech stimuli. When prior information enabled the comprehension of the degraded sentences, the left middle temporal gyrus and the left angular gyrus were activated, highlighting a role of these areas in meaning extraction. In contrast, the activation of the left inferior frontal gyrus (area 44/45) appeared to reflect the search for meaningful information in degraded speech material that could not be decoded because of mismatches with the prior information. Our results show that degraded sentences evoke instantaneously different percepts and activation patterns depending on the type of prior information, in line with prediction-based accounts of perception. Copyright © 2012 Wiley Periodicals, Inc.

  11. Prior entanglement between senders enables perfect quantum network coding with modification

    International Nuclear Information System (INIS)

    Hayashi, Masahito

    2007-01-01

    We find a protocol transmitting two quantum states crossly in the butterfly network only with prior entanglement between two senders. This protocol requires only one qubit transmission or two classical bits (cbits) transmission in each channel in the butterfly network. It is also proved that it is impossible without prior entanglement. More precisely, an upper bound of average fidelity is given in the butterfly network when prior entanglement is not allowed. The presented result concerns only the butterfly network, but our techniques can be applied to a more general graph

  12. Forecasting economy with Bayesian autoregressive distributed lag model: choosing optimal prior in economic downturn

    OpenAIRE

    Bušs, Ginters

    2009-01-01

    Bayesian inference requires an analyst to set priors. Setting the right prior is crucial for precise forecasts. This paper analyzes how optimal prior changes when an economy is hit by a recession. For this task, an autoregressive distributed lag (ADL) model is chosen. The results show that a sharp economic slowdown changes the optimal prior in two directions. First, it changes the structure of the optimal weight prior, setting smaller weight on the lagged dependent variable compared to varia...

  13. Optimization of Evacuation Warnings Prior to a Hurricane Disaster

    Directory of Open Access Journals (Sweden)

    Dian Sun

    2017-11-01

    Full Text Available The key purpose of this paper is to demonstrate that optimization of evacuation warnings by time period and impacted zone is crucial for efficient evacuation of an area impacted by a hurricane. We assume that people behave in a manner consistent with the warnings they receive. By optimizing the issuance of hurricane evacuation warnings, one can control the number of evacuees at different time intervals to avoid congestion in the process of evacuation. The warning optimization model is applied to a case study of Hurricane Sandy using the study region of Brooklyn. We first develop a model for shelter assignment and then use this outcome to model hurricane evacuation warning optimization, which prescribes an evacuation plan that maximizes the number of evacuees. A significant technical contribution is the development of an iterative greedy heuristic procedure for the nonlinear formulation, which is shown to be optimal for the case of a single evacuation zone with a single evacuee type case, while it does not guarantee optimality for multiple zones under unusual circumstances. A significant applied contribution is the demonstration of an interface of the evacuation warning method with a public transportation scheme to facilitate evacuation of a car-less population. This heuristic we employ can be readily adapted to the case where response rate is a function of evacuation number in prior periods and other variable factors. This element is also explored in the context of our experiment.

  14. Dish/stirling hybrid-receiver

    Science.gov (United States)

    Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

    2002-01-01

    A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through the array to give up additional heat to the receiver, and an inner surface covered with an extension of the heat-pipe wick, a pin-fin shroud sealed to the burner and exhaust plenums, an end seal, a flue-gas diversion tube and a flue-gas valve for use at off-design conditions to limit the temperature of the pre-heated air and fuel mixture, preventing pre-ignition.

  15. Prior exercise and antioxidant supplementation: effect on oxidative stress and muscle injury

    Directory of Open Access Journals (Sweden)

    Schilling Brian K

    2007-10-01

    Full Text Available Abstract Background Both acute bouts of prior exercise (preconditioning and antioxidant nutrients have been used in an attempt to attenuate muscle injury or oxidative stress in response to resistance exercise. However, most studies have focused on untrained participants rather than on athletes. The purpose of this work was to determine the independent and combined effects of antioxidant supplementation (vitamin C + mixed tocopherols/tocotrienols and prior eccentric exercise in attenuating markers of skeletal muscle injury and oxidative stress in resistance trained men. Methods Thirty-six men were randomly assigned to: no prior exercise + placebo; no prior exercise + antioxidant; prior exercise + placebo; prior exercise + antioxidant. Markers of muscle/cell injury (muscle performance, muscle soreness, C-reactive protein, and creatine kinase activity, as well as oxidative stress (blood protein carbonyls and peroxides, were measured before and through 48 hours of exercise recovery. Results No group by time interactions were noted for any variable (P > 0.05. Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P Conclusion There appears to be no independent or combined effect of a prior bout of eccentric exercise or antioxidant supplementation as used here on markers of muscle injury in resistance trained men. Moreover, eccentric exercise as used in the present study results in minimal blood oxidative stress in resistance trained men. Hence, antioxidant supplementation for the purpose of minimizing blood oxidative stress in relation to eccentric exercise appears unnecessary in this population.

  16. Effectiveness of furosemide in attenuating exercise-induced pulmonary haemorrhage in horses when administered at 4- and 24-h prior to high-speed training.

    Science.gov (United States)

    Knych, H K; Wilson, W D; Vale, A; Kass, P H; Arthur, R M; Jones, J H

    2018-05-01

    Due to the high prevalence of EIPH in racehorses and its potential impact on the horse's health, furosemide administration is permitted up to 4-h prior to post time in most North American racing jurisdictions. Anecdotal reports suggest that administration of furosemide 24-h prior to strenuous exercise may be equally effective in decreasing the severity of EIPH. To 1) compare the efficacy of furosemide in reducing the presence and severity of EIPH when administered 4- or 24-h prior to strenuous exercise 2) characterise electrolyte and blood parameters following administration of furosemide at 4- and 24-h prior to exercise. 3-way crossover. Fifteen Thoroughbred racehorses received 5 mL of 0.9% NaCl or 250 mg of furosemide either 4- or 24-h prior to a 5-furlong simulated race. Blood samples were collected prior to and post-run for determination of furosemide, lactate, haemoglobin and electrolyte concentrations. One-hour post-race, an endoscopic exam and bronchoalveolar lavage (BAL) were performed. Horses were assigned an EIPH score based on predetermined criteria and the number of red blood cells in BAL fluid was determined. Endoscopic EIPH scores were lower in the 4-h vs. the 24-h (P = 0.03) furosemide groups. RBC counts in BAL fluid were lower in the 4-h furosemide vs. saline treatment groups (P = 0.01) but no difference was noted between the saline and 24-h furosemide groups (P = 0.3), nor between the 4- and 24-h groups (P = 0.5). Small sample size and large range of running times for the 5-furlong work. While none of the treatments prevented EIPH, endoscopic scores and RBC counts in BAL fluid support the efficacy of furosemide in reducing the severity of EIPH. Endoscopic scores were lower in the 4-h furosemide group compared with 24-h administration. Red blood cell counts were lower in the 4-h furosemide group compared with saline treatment. © 2017 EVJ Ltd.

  17. Primary gonadal damage following treatment of brain tumors in childhood

    International Nuclear Information System (INIS)

    Ahmed, S.R.; Shalet, S.M.; Campbell, R.H.; Deakin, D.P.

    1983-01-01

    Gonadal function was studied in two groups of children previously treated for medulloblastoma with surgery followed by postoperative craniospinal irradiation. In group 1 but not in group 2, the children also received adjuvant chemotherapy for one to two years. All children in group 1 received a nitrosourea (BCNU or CCNU), plus vincristine in four and procarbazine in three patients. The nine children in group 1 showed clinical and biochemical evidence of gonadal damage with elevated serum FSH concentrations and, in the boys, small testes for their stage of pubertal development. In group 2 (n . 8), each child had completed pubertal development normally, the boys had adult sized testes and the girls regular menses. Gonadotropin values were normal in all eight children. We conclude that nitrosoureas were responsible for the gonadal damage in the children in group 1, with procarbazine also contributing to the damage in the three children who received this drug. In view of the limited proved value of adjuvant chemotherapy with nitrosoureas in the treatment of medulloblastoma, recognition of this serious complication of cytotoxic drug therapy may necessitate reassessing in which subgroups of children with medulloblastoma the benefits of adjuvant chemotherapy outweigh the complications

  18. Statistical Learning Is Not Affected by a Prior Bout of Physical Exercise.

    Science.gov (United States)

    Stevens, David J; Arciuli, Joanne; Anderson, David I

    2016-05-01

    This study examined the effect of a prior bout of exercise on implicit cognition. Specifically, we examined whether a prior bout of moderate intensity exercise affected performance on a statistical learning task in healthy adults. A total of 42 participants were allocated to one of three conditions-a control group, a group that exercised for 15 min prior to the statistical learning task, and a group that exercised for 30 min prior to the statistical learning task. The participants in the exercise groups cycled at 60% of their respective V˙O2 max. Each group demonstrated significant statistical learning, with similar levels of learning among the three groups. Contrary to previous research that has shown that a prior bout of exercise can affect performance on explicit cognitive tasks, the results of the current study suggest that the physiological stress induced by moderate-intensity exercise does not affect implicit cognition as measured by statistical learning. Copyright © 2015 Cognitive Science Society, Inc.

  19. Incorporating prior knowledge induced from stochastic differential equations in the classification of stochastic observations.

    Science.gov (United States)

    Zollanvari, Amin; Dougherty, Edward R

    2016-12-01

    In classification, prior knowledge is incorporated in a Bayesian framework by assuming that the feature-label distribution belongs to an uncertainty class of feature-label distributions governed by a prior distribution. A posterior distribution is then derived from the prior and the sample data. An optimal Bayesian classifier (OBC) minimizes the expected misclassification error relative to the posterior distribution. From an application perspective, prior construction is critical. The prior distribution is formed by mapping a set of mathematical relations among the features and labels, the prior knowledge, into a distribution governing the probability mass across the uncertainty class. In this paper, we consider prior knowledge in the form of stochastic differential equations (SDEs). We consider a vector SDE in integral form involving a drift vector and dispersion matrix. Having constructed the prior, we develop the optimal Bayesian classifier between two models and examine, via synthetic experiments, the effects of uncertainty in the drift vector and dispersion matrix. We apply the theory to a set of SDEs for the purpose of differentiating the evolutionary history between two species.

  20. Effect of bystander CPR initiation prior to the emergency call on ROSC and 30day survival

    DEFF Research Database (Denmark)

    Viereck, Søren; Palsgaard Møller, Thea; Kjær Ersbøll, Annette

    2017-01-01

    BACKGROUND: This study aimed at evaluating if time for initiation of bystander cardiopulmonary resuscitation (CPR) - prior to the emergency call (CPRprior) versus during the emergency call following dispatcher-assisted CPR (CPRduring) - was associated with return of spontaneous circulation (ROSC...... and corresponding emergency calls were evaluated. Multivariable logistic regression analyses were applied to evaluate the association between time for initiation of bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of CPRprior. RESULTS: The study...... included 548 emergency calls for OHCA patients receiving bystander CPR, 34.9% (n=191) in the CPRpriorgroup and 65.1% (n=357) in the CPRduringgroup. Multivariable analyses showed no difference in ROSC (OR=0.88, 95% CI: 0.56-1.38) or 30-day survival (OR=1.14, 95% CI: 0.68-1.92) between CPRpriorand CPRduring...

  1. 30 CFR 77.1712 - Reopening mines; notification; inspection prior to mining.

    Science.gov (United States)

    2010-07-01

    ... to mining. 77.1712 Section 77.1712 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... prior to mining. Prior to reopening any surface coal mine after it has been abandoned or declared... an authorized representative of the Secretary before any mining operations in such mine are...

  2. Prior Visual Experience Modulates Learning of Sound Localization Among Blind Individuals.

    Science.gov (United States)

    Tao, Qian; Chan, Chetwyn C H; Luo, Yue-Jia; Li, Jian-Jun; Ting, Kin-Hung; Lu, Zhong-Lin; Whitfield-Gabrieli, Susan; Wang, Jun; Lee, Tatia M C

    2017-05-01

    Cross-modal learning requires the use of information from different sensory modalities. This study investigated how the prior visual experience of late blind individuals could modulate neural processes associated with learning of sound localization. Learning was realized by standardized training on sound localization processing, and experience was investigated by comparing brain activations elicited from a sound localization task in individuals with (late blind, LB) and without (early blind, EB) prior visual experience. After the training, EB showed decreased activation in the precuneus, which was functionally connected to a limbic-multisensory network. In contrast, LB showed the increased activation of the precuneus. A subgroup of LB participants who demonstrated higher visuospatial working memory capabilities (LB-HVM) exhibited an enhanced precuneus-lingual gyrus network. This differential connectivity suggests that visuospatial working memory due to the prior visual experience gained via LB-HVM enhanced learning of sound localization. Active visuospatial navigation processes could have occurred in LB-HVM compared to the retrieval of previously bound information from long-term memory for EB. The precuneus appears to play a crucial role in learning of sound localization, disregarding prior visual experience. Prior visual experience, however, could enhance cross-modal learning by extending binding to the integration of unprocessed information, mediated by the cognitive functions that these experiences develop.

  3. Prior image constrained image reconstruction in emerging computed tomography applications

    Science.gov (United States)

    Brunner, Stephen T.

    Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

  4. Prior Knowledge Facilitates Mutual Gaze Convergence and Head Nodding Synchrony in Face-to-face Communication.

    Science.gov (United States)

    Thepsoonthorn, C; Yokozuka, T; Miura, S; Ogawa, K; Miyake, Y

    2016-12-02

    As prior knowledge is claimed to be an essential key to achieve effective education, we are interested in exploring whether prior knowledge enhances communication effectiveness. To demonstrate the effects of prior knowledge, mutual gaze convergence and head nodding synchrony are observed as indicators of communication effectiveness. We conducted an experiment on lecture task between lecturer and student under 2 conditions: prior knowledge and non-prior knowledge. The students in prior knowledge condition were provided the basic information about the lecture content and were assessed their understanding by the experimenter before starting the lecture while the students in non-prior knowledge had none. The result shows that the interaction in prior knowledge condition establishes significantly higher mutual gaze convergence (t(15.03) = 6.72, p < 0.0001; α = 0.05, n = 20) and head nodding synchrony (t(16.67) = 1.83, p = 0.04; α = 0.05, n = 19) compared to non-prior knowledge condition. This study reveals that prior knowledge facilitates mutual gaze convergence and head nodding synchrony. Furthermore, the interaction with and without prior knowledge can be evaluated by measuring or observing mutual gaze convergence and head nodding synchrony.

  5. Mind wandering during film comprehension: The role of prior knowledge and situational interest.

    Science.gov (United States)

    Kopp, Kristopher; Mills, Caitlin; D'Mello, Sidney

    2016-06-01

    This study assessed the occurrence and factors that influence mind wandering (MW) in the domain of film comprehension. The cascading model of inattention assumes that a stronger mental representation (i.e., a situation model) during comprehension results in less MW. Accordingly, a suppression hypothesis suggests that MW would decrease as a function of having the knowledge of the plot of a film prior to viewing, because the prior-knowledge would help to strengthen the situation model during comprehension. Furthermore, an interest-moderation hypothesis would predict that the suppression effect of prior-knowledge would only emerge when there was interest in viewing the film. In the current experiment, 108 participants either read a short story that depicted the plot (i.e., prior-knowledge condition) or read an unrelated story of equal length (control condition) prior to viewing the short film (32.5 minutes) entitled The Red Balloon. Participants self-reported their interest in viewing the film immediately before the film was presented. MW was tracked using a self-report method targeting instances of MW with metacognitive awareness. Participants in the prior-knowledge condition reported less MW compared with the control condition, thereby supporting the suppression hypothesis. MW also decreased over the duration of the film, but only for those with prior-knowledge of the film. Finally, prior-knowledge effects on MW were only observed when interest was average or high, but not when interest was low.

  6. l0 Sparsity for Image Denoising with Local and Global Priors

    Directory of Open Access Journals (Sweden)

    Xiaoni Gao

    2015-01-01

    Full Text Available We propose a l0 sparsity based approach to remove additive white Gaussian noise from a given image. To achieve this goal, we combine the local prior and global prior together to recover the noise-free values of pixels. The local prior depends on the neighborhood relationships of a search window to help maintain edges and smoothness. The global prior is generated from a hierarchical l0 sparse representation to help eliminate the redundant information and preserve the global consistency. In addition, to make the correlations between pixels more meaningful, we adopt Principle Component Analysis to measure the similarities, which can be both propitious to reduce the computational complexity and improve the accuracies. Experiments on the benchmark image set show that the proposed approach can achieve superior performance to the state-of-the-art approaches both in accuracy and perception in removing the zero-mean additive white Gaussian noise.

  7. Evolution of Industry Knowledge in the Public Domain: Prior Art Searching for Software Patents

    Directory of Open Access Journals (Sweden)

    Jinseok Park

    2005-03-01

    Full Text Available Searching prior art is a key part of the patent application and examination processes. A comprehensive prior art search gives the inventor ideas as to how he can improve or circumvent existing technology by providing up to date knowledge on the state of the art. It also enables the patent applicant to minimise the likelihood of an objection from the patent office. This article explores the characteristics of prior art associated with software patents, dealing with difficulties in searching prior art due to the lack of resources, and considers public contribution to the formation of prior art databases. It addresses the evolution of electronic prior art in line with technological development, and discusses laws and practices in the EPO, USPTO, and the JPO in relation to the validity of prior art resources on the Internet. This article also investigates the main features of searching sources and tools in the three patent offices as well as non-patent literature databases. Based on the analysis of various searching databases, it provides some strategies of efficient prior art searching that should be considered for software-related inventions.

  8. Factors associated with interest in receiving prison-based methadone maintenance therapy in Malaysia.

    Science.gov (United States)

    Mukherjee, Trena I; Wickersham, Jeffrey A; Desai, Mayur M; Pillai, Veena; Kamarulzaman, Adeeba; Altice, Frederick L

    2016-07-01

    Methadone maintenance therapy (MMT) is crucial for HIV prevention and treatment in people who inject opioids. In Malaysia, a large proportion of the prison population is affected by both HIV and opioid use disorders. This study assessed individual preferences and factors associated with interest in receiving MMT among male prisoners meeting criteria for opioid dependence in Malaysia. A convenience sample of 96 HIV-positive and 104 HIV-negative incarcerated men who met pre-incarceration criteria for opioid dependence was interviewed using a structured questionnaire to examine participant characteristics and attitudes toward MMT. Factors associated with interest in prison-based MMT initiation were identified using logistic regression analysis. Among all participants, 85 (42.5%) were interested in receiving MMT within prison. Independent correlates of interest in prison-based MMT were being previously married (AOR=4.15, 95% CI: 1.15, 15.02), previously incarcerated (AOR=5.68, 95% CI: 1.54, 21.02), depression (AOR=3.66, 95% CI: 1.68, 7.98), daily heroin use in the 30days prior to incarceration (AOR=5.53, 95% CI: 1.65, 18.58), and more favorable attitudes toward MMT (AOR=19.82, 95% CI: 6.07, 64.74). Overall, interest in receiving prison-based MMT was low, and was associated with adverse social, mental health, and drug use consequences. Incarceration provides a unique opportunity to initiate MMT for those who need it, however, optimal scale-up efforts must be systemic and address modifiable factors like improving attitudes toward and motivation for MMT. Informed or shared decision-making tools may be useful in improving expectations and acceptability of MMT. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Prior trauma exposure and serious illness at end of life: A national study of children in the US foster care system from 2005 to 2015.

    Science.gov (United States)

    Lindley, Lisa C; Slayter, Elspeth M

    2018-06-08

    Children in foster care suffer with serious illness at end of life. However, the relationship between prior trauma exposure and serious illness has received little empirical attention. The objectives were to examine the prevalence and type of trauma exposure, and investigate the relationship between prior trauma and serious illness among foster children at end of life. We used national longitudinal foster care data. We included children who were less than 18 years with residence in the United States. Serious illness (i.e., physical health, mental/behavioral health, developmental disabilities) was measured via the foster care files. Three measures of prior trauma exposure (i.e., maltreatment, drug/alcohol exposure, psychosocial stressors) were created. Using multivariate logistic regressions, we evaluated the influence of prior trauma on serious illness at end of life, while controlling for demographic, geographic, and foster care support characteristics. Sixty-eight percent of children experienced maltreatment, 28% exposure to parental drug/alcohol misuse, and 39% psychosocial stressors prior to entering foster care. Maltreatment was positively associated with physical health and developmental disabilities, while parental drug/alcohol exposure was inversely related to developmental disabilities. Psychosocial stressors contributed to the prediction of poor physical, mental, and developmental health. These findings suggest that trauma-informed end-of-life care may be a critical need among children in foster care with serious illness. Future directions are discussed, including collaboration between end-of-life clinicians and social service workers and the importance of future research to understand and improve the quality of health at end of life for this underserved population. Copyright © 2018. Published by Elsevier Inc.

  10. 25 CFR 11.303 - Notification of rights prior to custodial interrogation.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Notification of rights prior to custodial interrogation. 11.303 Section 11.303 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER... to custodial interrogation. Prior to custodial interrogation, the suspect shall be advised of the...

  11. Survey of rheumatologists on the use of the Philippine Guidelines on the Screening for Tuberculosis prior to use of Biologic Agents.

    Science.gov (United States)

    Aquino-Villamin, Melissa; Tankeh-Torres, Sandra; Lichauco, Juan Javier

    2016-11-01

    The use of biologic agents has become an important option in treating patients with rheumatoid arthritis. However, these drugs have been associated with an increased risk of tuberculosis (TB) reactivation. Local guidelines for TB screening prior to the use of biologic agents were developed to address this issue. This study is a survey describing the compliance of Filipino rheumatologists to these guidelines. Eighty-seven rheumatologists in the Philippines were given the questionnaire and responses from 61 rheumatologists were included in the analysis. All respondents agree that patients should be screened prior to giving the biologic agents. Local guidelines recommend screening with tuberculin skin test (TST) and chest radiograph. However, cut-off values considered for a positive TST and timing of initiation of biologic agents after starting TB prophylaxis and treatment varied among respondents. In addition, screening of close household contacts were only performed by 41 (69.5%) respondents. There were 11 respondents who reported 16 patients developing TB during or after receiving biologic agents, despite adherence to the guidelines. This survey describes the compliance rate of Filipino rheumatologists in applying current local recommendations for TB screening prior to initiating biologic agents. The incidence of new TB cases despite the current guidelines emphasizes the importance of compliance and the need to revise the guidelines based on updated existing literature. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  12. Metabolic Testing for Adults in a State Medicaid Program Receiving Antipsychotics: Remaining Barriers to Achieving Population Health Prevention Goals.

    Science.gov (United States)

    Morrato, Elaine H; Campagna, Elizabeth J; Brewer, Sarah E; Dickinson, L Miriam; Thomas, Deborah S K; Miller, Benjamin F; Dearing, James; Druss, Benjamin G; Lindrooth, Richard C

    2016-07-01

    Medicaid quality indicators track diabetes mellitus and cardiovascular disease screening in adults receiving antipsychotics and/or those with serious mental illness. To inform performance improvement interventions by evaluating the relative importance of patient, prescriber, and practice factors affecting metabolic testing. A retrospective cohort study was conducted using Missouri Medicaid administrative claims data (January 1, 2010, to December 31, 2012) linked with prescriber market data. The analysis included 9316 adults (age, 18-64 years) who were starting antipsychotic medication. Secondary analysis included the subset of adults (n = 1813) for whom prescriber knowledge, attitudes, and behavior survey data were available. Generalized estimating equations were performed to identify factors associated with failure to receive annual testing during antipsychotic treatment (adjusted odds ratio [OR], 6 encounters vs none; 0.33 [0.28-0.39]). Analysis incorporating prescriber practice information found lower failure to receive glucose testing if the patient received care at a CMHC (0.74 [0.64-0.85]) or if the initiating prescriber was a primary care practitioner (0.81 [0.66-1.00]). However, the initiating prescriber specialty-setting was not associated with lipid testing. Compared with prior reports, progress has been made to improve diabetes screening, but lipid screening remains particularly underutilized. Medicaid performance improvement initiatives should target all prescriber settings and not just behavioral health.

  13. Impact of Bayesian Priors on the Characterization of Binary Black Hole Coalescences.

    Science.gov (United States)

    Vitale, Salvatore; Gerosa, Davide; Haster, Carl-Johan; Chatziioannou, Katerina; Zimmerman, Aaron

    2017-12-22

    In a regime where data are only mildly informative, prior choices can play a significant role in Bayesian statistical inference, potentially affecting the inferred physics. We show this is indeed the case for some of the parameters inferred from current gravitational-wave measurements of binary black hole coalescences. We reanalyze the first detections performed by the twin LIGO interferometers using alternative (and astrophysically motivated) prior assumptions. We find different prior distributions can introduce deviations in the resulting posteriors that impact the physical interpretation of these systems. For instance, (i) limits on the 90% credible interval on the effective black hole spin χ_{eff} are subject to variations of ∼10% if a prior with black hole spins mostly aligned to the binary's angular momentum is considered instead of the standard choice of isotropic spin directions, and (ii) under priors motivated by the initial stellar mass function, we infer tighter constraints on the black hole masses, and in particular, we find no support for any of the inferred masses within the putative mass gap M≲5  M_{⊙}.

  14. A case-control study on the association between bladder cancer and prior bladder calculus.

    Science.gov (United States)

    Chung, Shiu-Dong; Tsai, Ming-Chieh; Lin, Ching-Chun; Lin, Herng-Ching

    2013-03-15

    Bladder calculus is associated with chronic irritation and inflammation. As there is substantial documentation that inflammation can play a direct role in carcinogenesis, to date the relationship between stone formation and bladder cancer (BC) remains unclear. This study aimed to examine the association between BC and prior bladder calculus using a population-based dataset. This case-control study included 2,086 cases who had received their first-time diagnosis of BC between 2001 and 2009 and 10,430 randomly selected controls without BC. Conditional logistic regressions were employed to explore the association between BC and having been previously diagnosed with bladder calculus. Of the sampled subjects, bladder calculus was found in 71 (3.4%) cases and 105 (1.1%) controls. Conditional logistic regression analysis revealed that the odds ratio (OR) of having been diagnosed with bladder calculus before the index date for cases was 3.42 (95% CI = 2.48-4.72) when compared with controls after adjusting for monthly income, geographic region, hypertension, diabetes, coronary heart disease, and renal disease, tobacco use disorder, obesity, alcohol abuse, and schistosomiasis, bladder outlet obstruction, and urinary tract infection. We further analyzed according to sex and found that among males, the OR of having been previously diagnosed with bladder calculus for cases was 3.45 (95% CI = 2.39-4.99) that of controls. Among females, the OR was 3.05 (95% CI = 1.53-6.08) that of controls. These results add to the evidence surrounding the conflicting reports regarding the association between BC and prior bladder calculus and highlight a potential target population for bladder cancer screening.

  15. The search for Infrared radiation prior to major earthquakes

    Science.gov (United States)

    Ouzounov, D.; Taylor, P.; Pulinets, S.

    2004-12-01

    This work describes our search for a relationship between tectonic stresses and electro-chemical and thermodynamic processes in the Earth and increases in mid-IR flux as part of a possible ensemble of electromagnetic (EM) phenomena that may be related to earthquake activity. Recent analysis of continuous ongoing long- wavelength Earth radiation (OLR) indicates significant and anomalous variability prior to some earthquakes. The cause of these anomalies is not well understood but could be the result of a triggering by an interaction between the lithosphere-hydrosphere and atmospheric related to changes in the near surface electrical field and gas composition prior to the earthquake. The OLR anomaly covers large areas surrounding the main epicenter. We have use the NOAA IR data to differentiate between the global and seasonal variability and these transient local anomalies. Indeed, on the basis of a temporal and spatial distribution analysis, an anomaly pattern is found to occur several days prior some major earthquakes. The significance of these observations was explored using data sets of some recent worldwide events.

  16. Effects of prior knowledge on decisions made under perceptual vs. categorical uncertainty

    Directory of Open Access Journals (Sweden)

    Kathleen eHansen

    2012-11-01

    Full Text Available Humans use prior knowledge to bias decisions made under uncertainty. In this fMRI study we predicted that different brain dynamics play a role when prior knowledge is added to decisions made under perceptual vs. categorical uncertainty. Subjects decided whether shapes belonged to Category S – smoother – or Category B – bumpier – under both uncertainty conditions, with or without prior knowledge cues. When present, the prior knowledge cue, 80/20 or 50/50, indicated that 80% and 20% (or 50% and 50% were the chances that responding "S" and "B" (or vice versa would be correct. During perceptual uncertainty, shapes were degraded with noise. During categorical uncertainty, shapes were ambiguous. Adding the 80/20 cue increased activation during perceptual uncertainty in bilateral lateral occipital cortex and left middle frontal gyrus (MidFG, and decreased activity in bilateral lateral occipital cortex during categorical uncertainty. Right MidFG and other frontoparietal regions were active in all conditions. The results demonstrate that left MidFG shows activation changes, suggestive of an influence on visual cortex, that depend on the factor that makes the decisions difficult. When sensory evidence is difficult to perceive, prior knowledge increases visual cortical activity. When the sensory evidence is easy to perceive but difficult to interpret, prior knowledge decreases visual cortical activity.

  17. Contribution of Prior Semantic Knowledge to New Episodic Learning in Amnesia

    Science.gov (United States)

    Kan, Irene P.; Alexander, Michael P.; Verfaellie, Mieke

    2009-01-01

    We evaluated whether prior semantic knowledge would enhance episodic learning in amnesia. Subjects studied prices that are either congruent or incongruent with prior price knowledge for grocery and household items and then performed a forced-choice recognition test for the studied prices. Consistent with a previous report, healthy controls'…

  18. Cortical plasticity as a mechanism for storing Bayesian priors in sensory perception.

    Science.gov (United States)

    Köver, Hania; Bao, Shaowen

    2010-05-05

    Human perception of ambiguous sensory signals is biased by prior experiences. It is not known how such prior information is encoded, retrieved and combined with sensory information by neurons. Previous authors have suggested dynamic encoding mechanisms for prior information, whereby top-down modulation of firing patterns on a trial-by-trial basis creates short-term representations of priors. Although such a mechanism may well account for perceptual bias arising in the short-term, it does not account for the often irreversible and robust changes in perception that result from long-term, developmental experience. Based on the finding that more frequently experienced stimuli gain greater representations in sensory cortices during development, we reasoned that prior information could be stored in the size of cortical sensory representations. For the case of auditory perception, we use a computational model to show that prior information about sound frequency distributions may be stored in the size of primary auditory cortex frequency representations, read-out by elevated baseline activity in all neurons and combined with sensory-evoked activity to generate a perception that conforms to Bayesian integration theory. Our results suggest an alternative neural mechanism for experience-induced long-term perceptual bias in the context of auditory perception. They make the testable prediction that the extent of such perceptual prior bias is modulated by both the degree of cortical reorganization and the magnitude of spontaneous activity in primary auditory cortex. Given that cortical over-representation of frequently experienced stimuli, as well as perceptual bias towards such stimuli is a common phenomenon across sensory modalities, our model may generalize to sensory perception, rather than being specific to auditory perception.

  19. The associations among prior drinking consequences, subjective evaluations, and subsequent alcohol outcomes.

    Science.gov (United States)

    Zaso, Michelle J; Park, Aesoon; Kim, Jueun; Gellis, Les A; Kwon, Hoin; Maisto, Stephen A

    2016-05-01

    Although the many positive and negative psychosocial consequences of alcohol use are well documented, evidence of the association between prior drinking consequences and subsequent alcohol-related outcomes is mixed. Social learning theory highlights that cognitive appraisals of prior drinking consequences play a crucial intermediate role in the relation of prior drinking consequences with subsequent alcohol-related outcomes. This prospective study was designed to test the mediating effects of subjective evaluations (i.e., perceived valence and controllability) in the association of prior drinking consequences with change in binge drinking and drinking consequences over time. Participants were 171 college students (69% female, 74% White, M age = 18.95 years, SD = 1.35) who completed 2 online surveys, with an average interval of 68 days (SD = 10.22) between assessments. Path analyses of the data did not support mediational effects of perceived valence or controllability of prior drinking consequences on subsequent alcohol-related outcomes. Specifically, greater frequency of negative consequences was associated with lower perceived valence and controllability, and greater frequency of positive consequences was associated with lower perceived controllability of the experienced consequences. However, perceptions of valence and controllability were not in turn associated with subsequent binge drinking and drinking consequences. Instead, greater frequency of positive consequences was directly associated with greater subsequent frequency of binge drinking. Findings highlight the importance of prior positive consequences in the escalation of binge drinking over a short period of time, although this relation may not be accounted for by perceptions of valence and controllability of the prior drinking consequences. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. 49 CFR 393.88 - Television receivers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Television receivers.