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Sample records for pictorial essay mammography

  1. Fetal MRI: A pictorial essay

    PubMed Central

    Rathee, Sapna; Joshi, Priscilla; Kelkar, Abhimanyu; Seth, Nagesh

    2016-01-01

    Ultrasonography (USG) is the primary method for antenatal fetal evaluation. However, fetal magnetic resonance imaging (MRI) has now become a valuable adjunct to USG in confirming/excluding suspected abnormalities and in the detection of additional abnormalities, thus changing the outcome of pregnancy and optimizing perinatal management. With the development of ultrafast sequences, fetal MRI has made remarkable progress in recent times. In this pictorial essay, we illustrate a spectrum of structural abnormalities affecting the central nervous system, thorax, genitourinary and gastrointestinal tract, as well as miscellaneous anomalies. Anomalies in twin gestations and placental abnormalities have also been included. PMID:27081224

  2. Imaging the Endometrium: A Pictorial Essay.

    PubMed

    Sadro, Claudia T

    2016-08-01

    Female gynaecologic conditions arising from the endometrium are common and depend on a woman's age, her menstrual history, and the use of medications such as hormone replacement and tamoxifen. Both benign and malignant conditions affect the endometrium. Benign conditions must be distinguished from malignant and premalignant conditions. The most commonly used imaging modality for evaluating the endometrium is pelvic ultrasound with transabdominal and transvaginal techniques. Additional imaging methods include hysterosonography and magnetic resonance imaging. This pictorial essay will review the normal and abnormal appearance of the endometrium and diagnostic algorithms to evaluate abnormal vaginal bleeding and abnormal endometrial thickness. PMID:27090929

  3. Malignant hyperechoic breast lesions at ultrasound: A pictorial essay.

    PubMed

    Tiang, Stephen; Metcalf, Cecily; Dissanayake, Deepthi; Wylie, Elizabeth

    2016-08-01

    Malignant breast lesions are typically hypoechoic at sonography. However, a small subgroup of hyperechoic malignant breast lesions is encountered in clinical practice. We present a pictorial essay of a number of different hyperechoic breast malignancies with mammographic, sonographic and histopathologic correlation. Suspicious sonographic features in a hyperechoic lesion include inhomogeneity in echogenic pattern, an irregular margin, posterior acoustic shadowing and internal vascularity. A hyperechoic lesion at ultrasound does not discount the need to undertake histological assessment of a mammographically suspicious lesion. PMID:27216965

  4. Anatomy of the ankle ligaments: a pictorial essay.

    PubMed

    Golanó, Pau; Vega, Jordi; de Leeuw, Peter A J; Malagelada, Francesc; Manzanares, M Cristina; Götzens, Víctor; van Dijk, C Niek

    2016-04-01

    Understanding the anatomy of the ankle ligaments is important for correct diagnosis and treatment. Ankle ligament injury is the most frequent cause of acute ankle pain. Chronic ankle pain often finds its cause in laxity of one of the ankle ligaments. In this pictorial essay, the ligaments around the ankle are grouped, depending on their anatomic orientation, and each of the ankle ligaments is discussed in detail. PMID:27052302

  5. Characteristic imaging features of body packers: a pictorial essay.

    PubMed

    Ab Hamid, Suzana; Abd Rashid, Saiful Nizam; Mohd Saini, Suraini

    2012-06-01

    The drug-trafficking business has risen tremendously because of the current increased demand for illegal narcotics. The smugglers conceal the drugs in their bodies (body packers) in order to bypass the tight security at international borders. A suspected body packer will normally be sent to the hospital for imaging investigations to confirm the presence of drugs in the body. Radiologists, therefore, need to be familiar with and able to identify drug packets within the human body because they shoulder the legal responsibilities. This pictorial essay describes the characteristic imaging features of drug packets within the gastrointestinal tract. PMID:22415809

  6. Extrafetal Findings on Fetal Magnetic Resonance Imaging: A Pictorial Essay.

    PubMed

    Epelman, Monica; Merrow, Arnold C; Guimaraes, Carolina V; Victoria, Teresa; Calvo-Garcia, Maria A; Kline-Fath, Beth M

    2015-12-01

    Although US is the mainstay of fetal imaging, magnetic resonance imaging (MRI) has become an invaluable adjunct in recent years. MRI offers superb soft tissue contrast that allows for detailed evaluation of fetal organs, particularly the brain, which enhances understanding of disease severity. MRI can yield results that are similar to or even better than those of US, particularly in cases of marked oligohydramnios, maternal obesity, or adverse fetal positioning. Incidentally detected extrafetal MRI findings are not uncommon and may affect clinical care. Physicians interpreting fetal MRI studies should be aware of findings occurring outside the fetus, including those structures important for the pregnancy. A systematic approach is necessary in the reading of such studies. This helps to ensure that important findings are not missed, appropriate clinical management is implemented, and unnecessary follow-up examinations are avoided. In this pictorial essay, the most common extrafetal abnormalities are described and illustrated. PMID:26614136

  7. MRI of Uncommon Lesions of the Large Bowel: A Pictorial Essay

    PubMed Central

    Lee, Christine U; Glockner, James F

    2014-01-01

    This pictorial essay briefly discusses methods for optimizing bowel imaging with magnetic resonance imaging (MRI) and illustrates the MRI appearance of a variety of unusual lesions involving or related specifically to the large bowel. PMID:25806129

  8. Radiologic manifestations of colloid cysts: a pictorial essay.

    PubMed

    Algin, Oktay; Ozmen, Evrim; Arslan, Halil

    2013-02-01

    Colloid cysts are among rare benign tumours of the third ventricle. Although the most frequent symptoms are headache and syncope, arrest hydrocephalus or sudden death could appear with colloid cysts. The aim of this pictorial essay was to increase awareness of the clinical presentation, computed tomography (CT) and magnetic resonance (MR) imaging spectrum, and treatment options of the colloid cysts. The data of 11 patients with histopathologically and/or clinically proven colloid cyst were analysed, retrospectively; and the neuroradiologic appearances of the cysts were evaluated. The CT and MR appearance of colloid cysts may change, depending on the viscosity or the cholesterol content of the cysts. However, the cystic content is the most important factor that could affect the success of treatment. Cysts that are especially rich in protein and cholesterol tend to be hyperdense on CT, hypointense on T2-weighted sequences and hyperintense on T1-weighted sequences. These cysts are viscous, and the success of aspiration is significantly low. In the diagnosis and evaluation of small-sized cysts that have an ingredient similar to cerebrospinal fluid, 3-dimensional sequences might be useful. The radiologic appearances of colloid cysts could play an important role in directing these patients to alternative surgical modalities, including resection. PMID:22575594

  9. Pictorial essay: Role of ultrasound in failed carpal tunnel decompression

    PubMed Central

    Botchu, Rajesh; Khan, Aman; Jeyapalan, Kanagaratnam

    2012-01-01

    USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression. PMID:22623813

  10. Incidentally Detected Mediastinal Vascular Anatomical Variants on PET-CT: A Pictorial Essay

    PubMed Central

    Paidipati, Kathyayini Gopalkrishna Murthy; Kashyap, Raghava; Tadimeti, Hima; Peyyeti, Mahidhar

    2015-01-01

    Positron emission tomography with computed tomography (PET–CT) is an integral part of oncology practice in the current-day scenario. The hybrid anatomical and metabolic imaging information in this imaging modality provides access to a wealth of incidental findings which can have implications in the management of the patient, especially when surgical options are being considered. In this pictorial essay, we present incidentally detected mediastinal vascular anomalies on PET–CT, along with a review of associated literature. PMID:25883859

  11. Pictorial essay: CT scan of appendicitis and its mimics causing right lower quadrant pain

    PubMed Central

    Sharma, Monika; Agrawal, Anjali

    2008-01-01

    CT scanning is widely used in the diagnostic workup of right lower quadrant pain. While appendicitis remains the most frequent cause, a majority of patients referred for suspected appendicitis turn out to have alternative diagnoses or a normal CT study. The purpose of our pictorial essay is to present an overview of the CT findings of appendicitis and its common mimics and to highlight the features that provide clues to alternative diagnoses.

  12. Pictorial essay of radiological features of benign intrathoracic masses

    PubMed Central

    Suut, Syahminan; Al-Ani, Zeid; Allen, Carolyn; Rajiah, Prabhakar; Durr-e-Sabih; AL-Harbi, Abdullah; AL-Jahdali, Hamdan; Khan, Ali Nawaz

    2015-01-01

    With increased exposure of patients to routine imaging, incidental benign intrathoracic masses are frequently recognized. Most have classical imaging features, which are pathognomonic for their benignity. The aim of this pictorial review is to educate the reader of radiological features of several types of intrathoracic masses. The masses are categorized based on their location/origin and are grouped into parenchymal, pleural, mediastinal, or bronchial. Thoracic wall masses that invade the thorax such as neurofibromas and lipomas are included as they may mimic intrathoracic masses. All examples are illustrated and include pulmonary hamartoma, pleural fibroma, sarcoidosis, bronchial carcinoid, and bronchoceles together with a variety of mediastinal cysts on plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI). Sometimes a multimodality approach would be needed to confirm the diagnosis in atypical cases. The study would include the incorporation of radionuclide studies and relevant discussion in a multidisciplinary setting. PMID:26664560

  13. Pictorial essay of radiological features of benign intrathoracic masses.

    PubMed

    Suut, Syahminan; Al-Ani, Zeid; Allen, Carolyn; Rajiah, Prabhakar; Durr-E-Sabih; Al-Harbi, Abdullah; Al-Jahdali, Hamdan; Khan, Ali Nawaz

    2015-01-01

    With increased exposure of patients to routine imaging, incidental benign intrathoracic masses are frequently recognized. Most have classical imaging features, which are pathognomonic for their benignity. The aim of this pictorial review is to educate the reader of radiological features of several types of intrathoracic masses. The masses are categorized based on their location/origin and are grouped into parenchymal, pleural, mediastinal, or bronchial. Thoracic wall masses that invade the thorax such as neurofibromas and lipomas are included as they may mimic intrathoracic masses. All examples are illustrated and include pulmonary hamartoma, pleural fibroma, sarcoidosis, bronchial carcinoid, and bronchoceles together with a variety of mediastinal cysts on plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI). Sometimes a multimodality approach would be needed to confirm the diagnosis in atypical cases. The study would include the incorporation of radionuclide studies and relevant discussion in a multidisciplinary setting. PMID:26664560

  14. Acute pancreatitis due to ascariasis: a sonographic pictorial essay on four cases.

    PubMed

    Lynser, Donboklang; Thangkhiew, R S; Laloo, Demitrost; Hek, M D; Marbaniang, Evarisalin; Tariang, Satisfy

    2016-06-01

    Ascariasis is the commonest helminthic disease to infect humans. Due to their wandering nature, the roundworms from the second part of the duodenum migrate through the biliary opening into the hepatobiliary and pancreatic ducts. Ascariasis is the most common parasitic cause of pancreatitis in endemic region. Pancreatitis can result due to pancreatic ascariasis, biliary ascariasis or both. Pancreatitis due to ascariasis can be severe and life-threatening. We present a pictorial essay of acute pancreatitis due to ascariasis on four cases. PMID:27059341

  15. Computed tomography (CT) of bowel and mesenteric injury in blunt abdominal trauma: a pictorial essay.

    PubMed

    Hassan, Radhiana; Abd Aziz, Azian; Mohamed, Siti Kamariah Che

    2012-08-01

    Computed tomography (CT) is currently the diagnostic modality of choice in the evaluation of clinically stable patients with blunt abdominal trauma, including the assessment of blunt bowel and mesenteric injuries. CT signs of bowel and/or mesenteric injuries are bowel wall defect, free air, oral contrast material extravasation, extravasation of contrast material from mesenteric vessels, mesenteric vascular beading, abrupt termination of mesenteric vessels, focal bowel wall thickening, mesenteric fat stranding, mesenteric haematoma and intraperitoneal or retroperitoneal fluid. This pictorial essay illustrates CT features of bowel and/or mesenteric injuries in patients with blunt abdominal trauma. Pitfalls in interpretation of images are emphasized in proven cases. PMID:23082464

  16. Imaging of carcinoma of the external auditory canal: a pictorial essay

    PubMed Central

    Ong, Cheng K.; Pua, Uei

    2008-01-01

    Abstract Carcinoma of the external auditory canal presents a challenge in management, largely due to limited experience in treating this rare disease and the lack of a universally accepted staging system. Prognosis is most dependent on the extent of local disease at presentation, while resection margin status is also a strong determinant of survival in post-operative patients. The intent of this pictorial essay is to review the pattern of tumour spread and highlight the value of imaging, particularly magnetic resonance imaging in pre-operative tumour mapping. PMID:18940738

  17. Multidetector computed tomography imaging of congenital anomalies of major airways: A pictorial essay.

    PubMed

    Sundarakumar, Dinesh Kumar; Bhalla, Ashu Seith; Sharma, Raju; Gupta, Arun Kumar; Kabra, Susheel Kumar; Jagia, Priya

    2011-12-28

    Congenital airway anomalies can be asymptomatic or may cause severe respiratory distress requiring immediate treatment. These anomalies can present early in life, or may be just incidental findings. It is important to recognize these entities to realize their clinical significance and to avoid false diagnosis. In this article, the various congenital airway anomalies and their imaging features by multidetector computed tomography (MDCT) are reviewed in order of occurrence during the embryological timeline. This pictorial essay reviews the various distinct congenital airway lesions and their MDCT manifestations. It also provides insight into the embryological basis of the congenital airway lesions encountered. PMID:22224177

  18. Tc-99m macro aggregated albumin scintigraphy – indications other than pulmonary embolism: A pictorial essay

    PubMed Central

    Gandhi, Sunny J; Babu, Sanjay; Subramanyam, Padma; Shanmuga Sundaram, Palaniswamy

    2013-01-01

    Introduction: Tc-99m macro aggregated albumin (MAA) is synonymous for lung perfusion scintigraphy and is part of the study in the evaluation of pulmonary thromboembolism. We wanted to highlight the utilities of Tc-99m MAA other than pulmonary embolism as a pictorial assay. Materials and Methods: Patients referred for Tc-99m MAA scintigraphy under various indications were included in this pictorial essay. Commercially available TechneScan LyoMAA cold kit from Mallinckrodt Medical B.V., Holland was used. Acquisition protocols for different indications are described in this article. Different clinical indications (e.g., pulmonary artery stenosis, hepatopulmonary syndrome, FEV1 calculation in lung surgery planning, selective internal radiation therapy planning, venography for deep venous thrombosis, left to right cardiac shunts, etc.) where Tc-99m MAA scintigraphy was asked for; how it helped in different clinical scenarios and how it can be used clinically is explained with unique and interesting case examples and images. We also reviewed the literature to look for certain remote indications of MAA imaging for the sake of completion like – (shunt scintigraphy, peritoneopleural communication, etc.) Conclusion: Tc-99m MAA is a very useful radiopharmaceutical, which can be used for many other indications apart from the commonly used indication of lung perfusion scan in pulmonary embolism. It can provide useful clinical information in other indications, which we try to highlight in this article. PMID:24250023

  19. DSA volumetric 3D reconstructions of intracranial aneurysms: A pictorial essay

    PubMed Central

    Cieściński, Jakub; Serafin, Zbigniew; Strześniewski, Piotr; Lasek, Władysław; Beuth, Wojciech

    2012-01-01

    Summary A gold standard of cerebral vessel imaging remains the digital subtraction angiography (DSA) performed in three projections. However, in specific clinical cases, many additional projections are required, or a complete visualization of a lesion may even be impossible with 2D angiography. Three-dimensional (3D) reconstructions of rotational angiography were reported to improve the performance of DSA significantly. In this pictorial essay, specific applications of this technique are presented in the management of intracranial aneurysms, including: preoperative aneurysm evaluation, intraoperative imaging, and follow-up. Volumetric reconstructions of 3D DSA are a valuable tool for cerebral vessels imaging. They play a vital role in the assessment of intracranial aneurysms, especially in evaluation of the aneurysm neck and the aneurysm recanalization. PMID:22844309

  20. Magnetic Resonance Imaging of Non-ischemic Cardiomyopathies: A Pictorial Essay.

    PubMed

    Olivas-Chacon, Cristina I; Mullins, Carola; Stewart, Kevan; Akle, Nassim; Calleros, Jesus E; Ramos-Duran, Luis R

    2015-01-01

    Non-ischemic cardiomyopathies are defined as either primary or secondary diseases of the myocardium resulting in cardiac dysfunction. While primary cardiomyopathies are confined to the heart and can be genetic or acquired, secondary cardiomyopathies show involvement of the heart as a manifestation of an underlying systemic disease including metabolic, inflammatory, granulomatous, infectious, or autoimmune entities. Non-ischemic cardiomyopathies are currently classified as hypertrophic, dilated, restrictive, or unclassifiable, including left ventricular non-compaction. Cardiovascular Magnetic Resonance Imaging (CMRI) not only has the capability to assess cardiac morphology and function, but also the ability to detect edema, hemorrhage, fibrosis, and intramyocardial deposits, providing a valuable imaging tool in the characterization of non-ischemic cardiomyopathies. This pictorial essay shows some of the most important non-ischemic cardiomyopathies with an emphasis on magnetic resonance imaging features. PMID:26199786

  1. Hydatid Disease Involving Some Rare Locations in the Body: a Pictorial Essay

    PubMed Central

    Demirpolat, Gulen; Sever, Ahmet; Bakaris, Sevgi; Bulbuloglu, Ertan; Elmas, Nevra

    2007-01-01

    Hydatid disease (HD) is an endemic illness in many countries, and it poses an important public health problem that's influenced by peoples' socioeconomic status and migration that spreads this disease. Although rare, it may occur in any organ or tissue. The most common site is the liver (59-75%), followed in frequency by lung (27%), kidney (3%), bone (1-4%) and brain (1-2%). Other sites such as the heart, spleen, pancreas and muscles are very rarely affected. Unusual sites for this disease can cause diagnostic problems. This pictorial essay illustrates various radiological findings of HD in the liver, spleen, kidney, pancreas, peritoneal cavity, omentum, adrenal, ovary, lung, mediastinum and retroperitoneum. Familiarity with the imaging findings of HD may be helpful in making an accurate diagnosis and preventing potential complications. PMID:18071284

  2. Mammography

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z Mammography Mammography is a specific type of breast imaging ... What are the limitations of Mammography? What is Mammography? Mammography is specialized medical imaging that uses a ...

  3. Mammography

    MedlinePlus

    ... first test. TYPES OF MAMMOGRAPHY Traditional mammography uses film, similar to routine x-rays. Digital mammography is ... risk of dying of breast cancer compared to film mammography. Three-dimensional (3D) mammography is a type ...

  4. Helical CT Angiography of Abdominal Aortic Aneurysms Treated with Suprarenal Stent Grafting: A Pictorial Essay

    SciTech Connect

    Sun Zhonghua

    2003-06-15

    The endovascular repair of abdominal aorticaneurysm (AAA) with stent grafts is rapidly becoming an important alternative to open repair. Suprarenal stent grafting, recently modified from conventional infrarenal stent grafting, is a technique for the purpose of treating patients with inappropriate aneurysm necks.Unlike open repair, the success of endoluminal repair cannot be ascertained by means of direct examination and thus relies on imaging results. The use of conventional angiography for arterial imaging has become less dominant, while helical computed tomography angiography(CTA) has become the imaging modality of choice for both preoperative assessment and postoperative followup after treatment with stent graft implants. There is an increasing likelihood that radiologists will become more and more involved in the procedure of aortic stent grafting and in giving the radiological report on these patients treated with stent grafts. It is necessary for radiologists to be familiar with the imaging findings, including common and uncommon appearances following aortic stent grafting. The purpose of this pictorial essay is to describe and present normal and abnormal imaging appearances following aortic stent grafting based on helical CTA.

  5. Pictorial essay: USG of lumps and bumps of the foot and ankle

    PubMed Central

    Botchu, Rajesh; Khan, Aman; Bhatt, Raj

    2010-01-01

    USG is a cost-effective and dynamic way to interrogate superficial lumps and bumps. We present a pictorial review of the USG findings in various “lumps and bumps” of the foot and ankle. PMID:20607019

  6. Anatomy of the distal tibiofibular syndesmosis in adults: a pictorial essay with a multimodality approach

    PubMed Central

    Hermans, John J; Beumer, Annechien; de Jong, Ton A W; Kleinrensink, Gert-Jan

    2010-01-01

    talocrural joint, understanding of the exact anatomy of both the osseous and ligamentous structures is essential in interpreting plain radiographs, CT and MR images, in ankle arthroscopy and in therapeutic management. With this pictorial essay we try to fill the hiatus in anatomic knowledge and provide a detailed anatomic description of the syndesmotic bones with the incisura fibularis, the syndesmotic recess, synovial fold and tibiofibular contact zone and the four syndesmotic ligaments. Each section describes a separate syndesmotic structure, followed by its clinical relevance and discussion of remaining questions. PMID:21108526

  7. Digital breast tomosynthesis (3D-mammography) screening: A pictorial review of screen-detected cancers and false recalls attributed to tomosynthesis in prospective screening trials.

    PubMed

    Houssami, Nehmat; Lång, Kristina; Bernardi, Daniela; Tagliafico, Alberto; Zackrisson, Sophia; Skaane, Per

    2016-04-01

    This pictorial review highlights cancers detected only at tomosynthesis screening and screens falsely recalled in the course of breast tomosynthesis screening, illustrating both true-positive (TP) and false-positive (FP) detection attributed to tomosynthesis. Images and descriptive data were used to characterise cases of screen-detection with tomosynthesis, sourced from prospective screening trials that performed standard (2D) digital mammography (DM) and tomosynthesis (3D-mammography) in the same screening participants. Exemplar cases from four trials highlight common themes of relevance to screening practice including: the type of lesions frequently made more conspicuous or perceptible by tomosynthesis (spiculated masses, and architectural distortions); the histologic findings (both TP and FP) of tomosynthesis-only detection; and the need to extend breast work-up protocols (additional imaging including ultrasound and MRI, and tomosynthesis-guided biopsy) if tomosynthesis is adopted for primary screening. PMID:27017251

  8. Mammography

    PubMed Central

    Samuels, Taube H.

    1992-01-01

    The combination of mammography and clinical examination provides the best means available to detect breast cancer. This article attempts to familiarize the family physician with mammographic terms and to clarify the role of mammography in detecting breast cancer. ImagesFigure 1Figure 2Figures 3-4Figure 5Figure 5Figure 6 PMID:21229125

  9. Imaging of common breast implants and implant-related complications: A pictorial essay

    PubMed Central

    Shah, Amisha T; Jankharia, Bijal B

    2016-01-01

    The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer. PMID:27413269

  10. From Grey Scale B-Mode to Elastosonography: Multimodal Ultrasound Imaging in Meningioma Surgery—Pictorial Essay and Literature Review

    PubMed Central

    Moiraghi, Alessandro; Casali, Cecilia; Legnani, Federico Giuseppe; Perin, Alessandro; Mattei, Luca; Richetta, Carla; Saini, Marco

    2015-01-01

    The main goal in meningioma surgery is to achieve complete tumor removal, when possible, while improving or preserving patient neurological functions. Intraoperative imaging guidance is one fundamental tool for such achievement. In this regard, intra-operative ultrasound (ioUS) is a reliable solution to obtain real-time information during surgery and it has been applied in many different aspect of neurosurgery. In the last years, different ioUS modalities have been described: B-mode, Fusion Imaging with pre-operative acquired MRI, Doppler, contrast enhanced ultrasound (CEUS), and elastosonography. In this paper, we present our US based multimodal approach in meningioma surgery. We describe all the most relevant ioUS modalities and their intraoperative application to obtain precise and specific information regarding the lesion for a tailored approach in meningioma surgery. For each modality, we perform a review of the literature accompanied by a pictorial essay based on our routinely use of ioUS for meningioma resection. PMID:26101779

  11. Thyroid calcifications: a pictorial essay.

    PubMed

    Lacout, Alexis; Chevenet, Carole; Thariat, Juliette; Marcy, Pierre Yves

    2016-05-01

    Incidental diagnosis of thyroid nodules is very common on adult neck ultrasonography examination. Thyroid calcifications are encountered in benign thyroid nodules and goiters as well as in thyroid malignancy. Depiction and characterization of such calcifications within a thyroid nodule may be a key element in the thyroid nodule diagnosis algorithm. The goal of this paper is to display typical radio-pathological correlations of various thyroid pathologies of benign and malignant conditions in which the calcification type diagnosis can play a key role in the final diagnosis of the thyroid nodule. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:245-251, 2016. PMID:26891122

  12. Neonatal neurosonography: A pictorial essay

    PubMed Central

    Bhat, Venkatraman; Bhat, Varun

    2014-01-01

    Neurosonography is a simple, established non-invasive technique for the intracranial assessment of preterm neonate. Apart from established indication in the evaluation of periventricular haemorrhage, it provides clue to wide range of pathology. This presentation provides a quick roadmap to the technique, imaging anatomy and spectrum of pathological imaging appearances encountered in neonates. PMID:25489132

  13. Integrated (18)F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging ((18)F-FDG PET/MRI), a multimodality approach for comprehensive evaluation of dementia patients: A pictorial essay.

    PubMed

    Jena, Amarnath; Renjen, Pushpendra Nath; Taneja, Sangeeta; Gambhir, Aashish; Negi, Pradeep

    2015-01-01

    Dementia, caused by irreversible neurodegenerative disorders such as Alzheimer's disease or reversible non-degenerative conditions, is rapidly becoming one of the most alarming health problems in our aging society. This cognitive disorder associated with a multitude of clinical differentials with overlapping clinical, pathological, and imaging features is difficult to diagnose and treat, as it often presents late after significant neuronal damage has already occurred. Novel disease-modifying treatments being developed will have to be corroborated with innovative imaging biomarkers so that earlier reliable diagnosis can be made and treatment initiated upon. Along with new specific PET radiotracers, integrated PET/MRI with combined methodological advantage and simultaneously acquired structural-cum-functional information may help achieve this goal. The present pictorial essay details our experiences with PET/MRI in dementing disorders, along with reviewing recent advances and future scope. PMID:26752814

  14. Integrated 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging (18F-FDG PET/MRI), a multimodality approach for comprehensive evaluation of dementia patients: A pictorial essay

    PubMed Central

    Jena, Amarnath; Renjen, Pushpendra Nath; Taneja, Sangeeta; Gambhir, Aashish; Negi, Pradeep

    2015-01-01

    Dementia, caused by irreversible neurodegenerative disorders such as Alzheimer's disease or reversible non-degenerative conditions, is rapidly becoming one of the most alarming health problems in our aging society. This cognitive disorder associated with a multitude of clinical differentials with overlapping clinical, pathological, and imaging features is difficult to diagnose and treat, as it often presents late after significant neuronal damage has already occurred. Novel disease-modifying treatments being developed will have to be corroborated with innovative imaging biomarkers so that earlier reliable diagnosis can be made and treatment initiated upon. Along with new specific PET radiotracers, integrated PET/MRI with combined methodological advantage and simultaneously acquired structural-cum-functional information may help achieve this goal. The present pictorial essay details our experiences with PET/MRI in dementing disorders, along with reviewing recent advances and future scope. PMID:26752814

  15. [Congenital gastrointestinal tract obstructions (pictorial essay)].

    PubMed

    Coşkun, Abdulhakim; Sevinç, Halil

    2004-03-01

    A wide spectrum of congenital anomalies may cause obstruction in the upper and lower gastrointestinal tract. Neonates with complete upper intestinal obstruction do not usually require further radiological evaluation after radiography. Barium studies are sometimes needed. Barium studies and other comprehensive methods such as ultrasonography, computed tomography and magnetic resonance imaging are usually complementary procedures which are not usually helpful and may even delay surgery, resulting in some complications and death. The decision to perform a given imaging examination should be considered carefully to avoid unnecessary radiation exposure to the patient. The diagnosis of low intestinal obstruction is usually apparent at abdominal radiography because of the presence of many dilated loops. The differentiation between ileal and colonic obstruction can be made with a contrast enema study. Dilute ionic, water-soluble contrast agents and non-balloon tip catheter of appropriate size is preferred for neonatal contrast enemas. Barium sulphate suspensions typically should not be used because of their potential to exacerbate the impaction of meconium plugs in meconium ileus, whereas water-soluble enemas can be therapeutic. PMID:15054709

  16. [Pulmonary aspergillosis: variable appearances (pictorial essay)].

    PubMed

    Yildirim, Nalan; Topal, Uğur

    2004-06-01

    Pulmonary aspergillosis can present in different clinical, pathological and radiological forms depending on the patient's immunological status and underlying pulmonary disease. Allergic bronchopulmonary aspergillosis, aspergilloma, invasive and semi-invasive forms can be recognized. In this article, we review the radiological findings of different forms of pulmonary aspergillosis. PMID:15236126

  17. MDCT evaluation of sternal variations: Pictorial essay

    PubMed Central

    Duraikannu, Chary; Noronha, Olma V; Sundarrajan, Pushparajan

    2016-01-01

    Sternal variations and anomalies have been identified in the past during autopsy or cadaveric studies. Recently, an increasing number of minor sternal variations have been reported with the advent of multidetector computed tomography (CT). Although there are many sternal variations that occur with varying appearance and prevalence, most of them are not recognized or are underreported during routine imaging of thorax. Identification of sternal variations is important to differentiate from pathological conditions and to prevent fatal complications prior to sternal interventions like marrow aspiration or acupuncture. This article aims to describe the minor and asymptomatic sternal variations by multidetector CT and their clinical significance. PMID:27413263

  18. Bone tumor mimickers: A pictorial essay

    PubMed Central

    Mhuircheartaigh, Jennifer Ni; Lin, Yu-Ching; Wu, Jim S

    2014-01-01

    Focal lesions in bone are very common and many of these lesions are not bone tumors. These bone tumor mimickers can include numerous normal anatomic variants and non-neoplastic processes. Many of these tumor mimickers can be left alone, while others can be due to a significant disease process. It is important for the radiologist and clinician to be aware of these bone tumor mimickers and understand the characteristic features which allow discrimination between them and true neoplasms in order to avoid unnecessary additional workup. Knowing which lesions to leave alone or which ones require workup can prevent misdiagnosis and reduce patient anxiety. PMID:25114385

  19. Pediatric stress fractures: a pictorial essay

    PubMed Central

    Shelat, Nirav H.; El-Khoury, Georges Y.

    2016-01-01

    More children are participating in organized and recreational athletics at a younger age. It has been well documented that increased athletic specialization and year-round activities have resulted in higher incidences of overuse injuries, including stress fractures and stress reactions. Initially, stress fractures can be radiographically occult. Continued stress on the injured bone or cartilage can lead to progressive radiographic changes. Because of the prevalence of these injuries, both orthopedic surgeons and radiologists should be aware of the radiographic and magnetic resonance imaging (MRI) features of common stress fractures in children. This article reviews frequently encountered stress fractures involving various bones in the pediatric population. PMID:27528851

  20. Imaging of skull base: Pictorial essay

    PubMed Central

    Raut, Abhijit A; Naphade, Prashant S; Chawla, Ashish

    2012-01-01

    The skull base anatomy is complex. Numerous vital neurovascular structures pass through multiple channels and foramina located in the base skull. With the advent of computerized tomography (CT) and magnetic resonance imaging (MRI), accurate preoperative lesion localization and evaluation of its relationship with adjacent neurovascular structures is possible. It is imperative that the radiologist and skull base surgeons are familiar with this complex anatomy for localizing the skull base lesion, reaching appropriate differential diagnosis, and deciding the optimal surgical approach. CT and MRI are complementary to each other and are often used together for the demonstration of the full disease extent. This article focuses on the radiological anatomy of the skull base and discusses few of the common pathologies affecting the skull base. PMID:23833423

  1. Valuing Essays: Essaying Values

    ERIC Educational Resources Information Center

    Badley, Graham

    2010-01-01

    The essay regularly comes under attack. It is criticised for being rigidly linear rather than flexible and reflective. I first challenge this view by examining reasons why the essay should be valued as an important genre. Secondly, I propose that in using the essay form students and academics necessarily exemplify their own critical values. Essays…

  2. Pictorial Superiority Effect

    ERIC Educational Resources Information Center

    Nelson, Douglas L.; And Others

    1976-01-01

    Pictures generally show superior recognition relative to their verbal labels. This experiment was designed to link this pictorial superiority effect to sensory or meaning codes associated with the two types of symbols. (Editor)

  3. Aspiration pneumonia in children: an iconographic essay*

    PubMed Central

    de Oliveira, Gabriel Antonio; Pessanha, Laís Bastos; Guerra, Luiz Felipe Alves; Martins, Diego Lima Nava; Rondina, Ronaldo Garcia; Silva, Jamine Ronacher Passos

    2015-01-01

    In most cases of aspiration pneumonia in children, the disease is specific to this age group. Clinical and radiological correlation is essential for the diagnosis. The present pictorial essay is aimed at showing typical images of the most common etiologies. PMID:26811557

  4. Reaching into Pictorial Spaces

    NASA Astrophysics Data System (ADS)

    Volcic, Robert; Vishwanath, Dhanraj; Domini, Fulvio

    2014-02-01

    While binocular viewing of 2D pictures generates an impression of 3D objects and space, viewing a picture monocularly through an aperture produces a more compelling impression of depth and the feeling that the objects are "out there", almost touchable. Here, we asked observers to actually reach into pictorial space under both binocular- and monocular-aperture viewing. Images of natural scenes were presented at different physical distances via a mirror-system and their retinal size was kept constant. Targets that observers had to reach for in physical space were marked on the image plane, but at different pictorial depths. We measured the 3D position of the index finger at the end of each reach-to-point movement. Observers found the task intuitive. Reaching responses varied as a function of both pictorial depth and physical distance. Under binocular viewing, responses were mainly modulated by the different physical distances. Instead, under monocular viewing, responses were modulated by the different pictorial depths. Importantly, individual variations over time were minor, that is, observers conformed to a consistent pictorial space. Monocular viewing of 2D pictures thus produces a compelling experience of an immersive space and tangible solid objects that can be easily explored through motor actions.

  5. FDA Certified Mammography Facilities

    MedlinePlus

    ... Products Radiation-Emitting Products Home Radiation-Emitting Products Mammography Quality Standards Act and Program Consumer Information (MQSA) ... it Email Print This list of FDA Certified Mammography Facilities is updated weekly. If you click on ...

  6. Fatty lesions in and around the heart: a pictorial review

    PubMed Central

    Restrepo, C S; Ocazionez, D; Suby-Long, T; Vargas, D

    2015-01-01

    A wide variety of fat-containing entities occur in and near the heart. These findings are often encountered by radiologists and may be incidental or the reason for the patient's clinical presentation. Cross-sectional imaging helps to characterize the extent of these lesions and to formulate a differential diagnosis, which varies by lesion location, imaging features and patient demographics. The purpose of this pictorial essay is to familiarize radiologists with these fat-containing lesions and to help avoid misdiagnosis and errors in management. This pictorial review will discuss the normal fatty structures in and around the heart. A range of common and uncommon fat-containing lesions will then be reviewed based upon lesion location. PMID:25950727

  7. Diogene pictorial drift chamber

    SciTech Connect

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive).

  8. The ultrasonographic diagnosis of cystic cervical lesions: a pictorial essay.

    PubMed

    Lenghel, Lavinia Manuela; Băciuţ, Grigore; Băciuţ, Mihaela; Rotaru, Horaţiu; Bran, Simion; Dinu, Cristian; Botar-Jid, Carolina; Gersak, Mirela; Dudea, Sorin M

    2016-06-01

    The importance of ultrasonographic (US) examination in the evaluation of the superficial structures of the head and neck region is increasing due to the widespread availability of modern equipment (such as high-frequency transducers) and modern techniques. In the case of a cervical lesion, ultrasound is usually the first imaging method used to assess the changes. First of all, US is capable of differentiating between cystic and solid structures, and based on the US appearance correlated with the age of the patient, location and growing pattern, the appropriate diagnosis is possible with a high accuracy. The aim of the present paper is to describe the US features of the most common cystic lesions encountered in the head and neck region. PMID:27239661

  9. Revised Atlanta Classification for Acute Pancreatitis: A Pictorial Essay.

    PubMed

    Foster, Bryan R; Jensen, Kyle K; Bakis, Gene; Shaaban, Akram M; Coakley, Fergus V

    2016-01-01

    The 2012 revised Atlanta classification is an update of the original 1992 Atlanta classification, a standardized clinical and radiologic nomenclature for acute pancreatitis and associated complications based on research advances made over the past 2 decades. Acute pancreatitis is now divided into two distinct subtypes, necrotizing pancreatitis and interstitial edematous pancreatitis (IEP), based on the presence or absence of necrosis, respectively. The revised classification system also updates confusing and sometimes inaccurate terminology that was previously used to describe pancreatic and peripancreatic collections. As such, use of the terms acute pseudocyst and pancreatic abscess is now discouraged. Instead, four distinct collection subtypes are identified on the basis of the presence of pancreatic necrosis and time elapsed since the onset of pancreatitis. Acute peripancreatic fluid collections (APFCs) and pseudocysts occur in IEP and contain fluid only. Acute necrotic collections (ANCs) and walled-off necrosis (WON) occur only in patients with necrotizing pancreatitis and contain variable amounts of fluid and necrotic debris. APFCs and ANCs occur within 4 weeks of disease onset. After this time, APFCs or ANCs may either resolve or persist, developing a mature wall to become a pseudocyst or a WON, respectively. Any collection subtype may become infected and manifest as internal gas, though this occurs most commonly in necrotic collections. In this review, the authors present a practical image-rich guide to the revised Atlanta classification system, with the goal of fostering implementation of the revised system into radiology practice, thereby facilitating accurate communication among clinicians and reinforcing the radiologist's role as a key member of a multidisciplinary team in treating patients with acute pancreatitis. (©)RSNA, 2016. PMID:27163588

  10. Pictorial essay: Ultrasonography in ‘tennis leg’

    PubMed Central

    Shah, Jeshil R; Shah, Bipin R; Shah, Ankit B

    2010-01-01

    Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term ‘tennis leg’. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up. PMID:21577246

  11. Imaging and interventions in idiopathic intracranial hypertension: A pictorial essay.

    PubMed

    Sivasankar, Rajeev; Pant, Rochan; Indrajit, Inna K; Negi, Raj S; Sahu, Samresh; Hashim, P I; D'Souza, John

    2015-01-01

    Intracranial hypertension is a syndrome of elevated intracranial pressure that can be primary or secondary. The primary form, now termed idiopathic intracranial hypertension (IIH), was in the past a disease of exclusion and imaging played a limited role of excluding organic causes of raised intracranial pressure. However imaging markers have been described with patients with IIH at the orbit, sella and cerebral venous system. We wish to reiterate the characteristic imaging features of this poorly understood disease and also emphasise that stenting of the transverse sinus in select cases of IIH is an efficacious option. PMID:26752823

  12. Imaging and interventions in idiopathic intracranial hypertension: A pictorial essay

    PubMed Central

    Sivasankar, Rajeev; Pant, Rochan; Indrajit, Inna K; Negi, Raj S; Sahu, Samresh; Hashim, PI; D’Souza, John

    2015-01-01

    Intracranial hypertension is a syndrome of elevated intracranial pressure that can be primary or secondary. The primary form, now termed idiopathic intracranial hypertension (IIH), was in the past a disease of exclusion and imaging played a limited role of excluding organic causes of raised intracranial pressure. However imaging markers have been described with patients with IIH at the orbit, sella and cerebral venous system. We wish to reiterate the characteristic imaging features of this poorly understood disease and also emphasise that stenting of the transverse sinus in select cases of IIH is an efficacious option. PMID:26752823

  13. Imaging Spectrum of Cerebellar Pathologies: A Pictorial Essay

    PubMed Central

    Arora, Richa

    2015-01-01

    Summary The cerebellum is a crucial structure of hindbrain which helps in maintaining motor tone, posture, gait and also coordinates skilled voluntary movements including eye movements. Cerebellar abnormalities have different spectrum, presenting symptoms and prognosis as compared to supratentorial structures and brainstem. This article intends to review the various pathological processes involving the cerebellum along with their imaging features on MR, which are must to know for all radiologists, neurologists and neurosurgeons for their prompt diagnosis and management. PMID:25806100

  14. Conflicts, snapping and instability of the tendons. Pictorial essay

    PubMed Central

    Fantino, Olivier; Borne, J.; Bordet, Bertrand

    2012-01-01

    Conflicts, snapping and instability of the tendons are common, and ultrasound (US) is the method of choice for evidencing these conditions thanks to the possibility to perform dynamic maneuvers during imaging studies. A conflict can occur between a tendon and a bone structure, other tendons, the retinacula or pulleys. Snapping can occur due to instability caused by rupture of the retinaculum, conflict between a thickened retinaculum and a bone prominence or due to an abnormal position of the tendon. Instability can occur due to insufficient ability of the retinaculum to keep the tendons in the bone groove or its failure to hold the tendons applied to the bone. The technique for evidencing conflicts, snapping and instability of the tendons is very demanding because it requires a thorough knowledge of the US appearance and dynamic maneuvers. However, at the present time US examination completed with dynamic maneuvers is the investigation of choice for evidencing these disorders and providing the clinicians with the necessary information. PMID:23396604

  15. Pictorial essay: B-scan ultrasonography in ocular abnormalities

    PubMed Central

    Aironi, VD; Gandage, SG

    2009-01-01

    B-scan ultrasonography (USG) is a simple, noninvasive tool for diagnosing lesions of the posterior segment of the eyeball. Common conditions such as cataract, vitreous degeneration, retinal detachment, ocular trauma, choroidal melanoma, and retinoblastoma can be accurately evaluated with this modality. B-scan USG is cost-effective, which is an important consideration in the rural setting. In addition, it is noninvasive and easily available and the results are reproducible. PMID:19881064

  16. Uncommon Causes of Acute Abdominal Pain – A Pictorial Essay

    PubMed Central

    Hariharan, Mahesh; Balasubramaniam, Rajan; Shetty, Sharath Kumar; Yadavalli, Shanthala; Ahetasham, Mohammed; Devarapalli, Sravya

    2016-01-01

    Acute abdomen is one of the most common clinical conditions requiring a radiological investigation. Ultrasound is the primary modality of choice which can diagnose some of the common causes of acute abdomen. However, sometimes the underlying cause for the pain is far more complicated than expected mandating a high degree of suspicion to suggest further investigation with contrast enhanced computed tomography or magnetic resonance imaging. Here, we have compiled a comprehensive series of selected cases to highlight the conditions which can be easily overlooked unless carefully sought for. This article also emphasizes the importance of multimodality approach to arrive at the final diagnosis with an increased overall diagnostic accuracy which in turn improves patient management and prognosis. PMID:27014500

  17. Uncommon presentations of common pancreatic neoplasms: a pictorial essay.

    PubMed

    D'Onofrio, Mirko; De Robertis, Riccardo; Capelli, Paola; Tinazzi Martini, Paolo; Crosara, Stefano; Gobbo, Stefano; Butturini, Giovanni; Salvia, Roberto; Barbi, Emilio; Girelli, Roberto; Bassi, Claudio; Pederzoli, Paolo

    2015-08-01

    Pancreatic neoplasms are a wide group of solid and cystic lesions with different and often characteristic imaging features, clinical presentations, and management. Among solid tumors, ductal adenocarcinoma is the most common: it arises from exocrine pancreas, comprises about 90% of all pancreatic neoplasms, and generally has a bad prognosis; its therapeutic management must be multidisciplinary, involving surgeons, oncologists, gastroenterologists, radiologists, and radiotherapists. The second most common solid pancreatic neoplasms are neuroendocrine tumors: they can be divided into functioning or non-functioning and present different degrees of malignancy. Cystic pancreatic neoplasms comprise serous neoplasms, which are almost always benign, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms, which can vary from benign to frankly malignant lesions, and solid pseudopapillary tumors. Other pancreatic neoplasms, such as lymphoma, metastases, or pancreatoblastoma, are rarely seen in clinical practice and have different and sometimes controversial managements. Rare clinical presentations and imaging appearance of the most common pancreatic neoplasms, both solid and cystic, are more frequently seen and clinically relevant than rare pancreatic tumors; their pathologic and radiologic appearances must be known to improve their management. The purpose of this paper is to present some rare or uncommon clinical and radiological presentations of common pancreatic neoplasms providing examples of multi-modality imaging approach with pathologic correlations, thus describing the histopathological bases that can explain the peculiar imaging features, in order to avoid relevant misdiagnosis and to improve lesion management. PMID:25772002

  18. Scholarly Essays.

    ERIC Educational Resources Information Center

    American Education, 1983

    1983-01-01

    A selection of essays by 12 1983 Presidential Scholars entitled Opportunity in America; Under the Influence of High Fashion; Law and Human Freedom; The Effects of Computers in Education; Prejudice, Cultural Heritage, and National Unity; The Visual Artist in a Technological Society; Dorothy Meets Schopenhauer; Rise Above; and Mathematics as a…

  19. The design of pictorial instruments

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.

    1995-01-01

    An historical overview of the development and design of pictorial displays is presented with particular emphasis on the research related to civilian aerospace applications carried out at the Ames Research Center. The use of geometric and symbolic enhancements to counteract the inherent ambiguities in perspective projections is discussed with reference to an aircraft traffic display application. Current design and perceptual issues related to head-mounted systems for virtual environment simulation and telepresence displays are also discussed. Finally, the importance of incorporating error display and control in the design of pictorial displays is addressed in the context of an orbital maneuver planning application.

  20. Pictorial Analogies XII: Stoichiometric Calculations.

    ERIC Educational Resources Information Center

    Fortman, John J.

    1994-01-01

    Pictorial analogies that demonstrate concepts of amounts allow instructors to teach that in stoichiometric problems, the number--or moles--of molecules of a chemical is what matters, even though it must be measured in masses or volumes. Analogies to stoichiometric relationships include the ratio of four wheels to one body in making wagons and…

  1. Frequently Asked Questions about Digital Mammography

    MedlinePlus

    ... Consumer Information (MQSA) Frequently Asked Questions About Digital Mammography Share Tweet Linkedin Pin it More sharing options ... mammography exams, such as DBT? What is digital mammography? Full field digital mammography (FFDM, also known simply ...

  2. Regulatory Compliance in Mammography.

    PubMed

    Loesch, Jennifer

    2016-03-01

    Although the Mammography Quality Standards Act (MQSA) passed when analog mammography and film processors were used across the United States, now most health care facilities have full-field digital mammography. This article reviews MQSA requirements including qualifications for personnel, the clinical image evaluation process, and components of a quality control program. In light of technological advances, the U.S. Food and Drug Administration's extension certificate for digital breast tomosynthesis is discussed, along with the American College of Radiology's Breast Imaging Center of Excellence designation and laws regarding density notification. PMID:26952076

  3. Pictorial communication: Pictures and the synthetic universe

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.

    1989-01-01

    Principles for the design of dynamic spatial instruments for communicating quantitative information to viewers are considered through a brief review of the history of pictorial communication. Pictorial communication is seen to have two directions: (1) from the picture to the viewer; and (2) from the viewer to the picture. Optimization of the design of interactive instruments using pictorial formats requires an understanding of the manipulative, perceptual, and cognitive limitations of human viewers.

  4. The Essay Canon.

    ERIC Educational Resources Information Center

    Bloom, Lynn Z.

    1999-01-01

    Explores the relation of essays to canon theory, explains why the only essay canon to be publicly identified in the 20th century is a powerful teaching canon. Shows "where essays live," how they arrive in the teaching canon, and why they stay there. Examines how essays are taught. Looks at the future of the essay canon. (SR)

  5. An Intelligent Pictorial Information System

    NASA Astrophysics Data System (ADS)

    Lee, Edward T.; Chang, B.

    1987-05-01

    In examining the history of computer application, we discover that early computer systems were developed primarily for applications related to scientific computation, as in weather prediction, aerospace applications, and nuclear physics applications. At this stage, the computer system served as a big calculator to perform, in the main, manipulation of numbers. Then it was found that computer systems could also be used for business applications, information storage and retrieval, word processing, and report generation. The history of computer application is summarized in Table I. The complexity of pictures makes picture processing much more difficult than number and alphanumerical processing. Therefore, new techniques, new algorithms, and above all, new pictorial knowledge, [1] are needed to overcome the limitatins of existing computer systems. New frontiers in designing computer systems are the ways to handle the representation,[2,3] classification, manipulation, processing, storage, and retrieval of pictures. Especially, the ways to deal with similarity measures and the meaning of the word "approximate" and the phrase "approximate reasoning" are an important and an indispensable part of an intelligent pictorial information system. [4,5] The main objective of this paper is to investigate the mathematical foundation for the effective organization and efficient retrieval of pictures in similarity-directed pictorial databases, [6] based on similarity retrieval techniques [7] and fuzzy languages [8]. The main advantage of this approach is that similar pictures are stored logically close to each other by using quantitative similarity measures. Thus, for answering queries, the amount of picture data needed to be searched can be reduced and the retrieval time can be improved. In addition, in a pictorial database, very often it is desired to find pictures (or feature vectors, histograms, etc.) that are most similar to or most dissimilar [9] to a test picture (or feature

  6. A Photographic Essay of Apache Children in Early Times, Volume 2-Part C.

    ERIC Educational Resources Information Center

    Thompson, Doris; Jacobs, Ben

    As part of a series of guides designed for instruction of American Indian children and youth, this resource guide constitutes a pictorial essay on life of the Apache child from 1880 to the early 20th century. Each of the 12 photographs is accompanied by an historical narrative which describes one or more cultural aspects of Apache childhood.…

  7. A Photographic Essay of the San Carlos Apache Indians, Volume 2-Part A.

    ERIC Educational Resources Information Center

    Soto, Ed; And Others

    As part of a series of guides designed for instruction of American Indian children and youth, this resource guide constitutes a pictorial essay on the San Carlos Apache Reservation founded in the late 1800's and located in Arizona's Gila County. An historical narrative and discussion questions accompany each of the 12 photographs. Photographic…

  8. A Photographic Essay of Apache Chiefs and Warriors, Volume 2-Part B.

    ERIC Educational Resources Information Center

    Barkan, Gerald; Jacobs, Ben

    As part of a series designed for instruction of American Indian children and youth, this resource guide constitutes a pictorial essay describing forts, Indian agents, and Apache chiefs, warriors, and scouts of the 19th century. Accompanying each picture is a brief historical-biographical narrative. Focus is on Apache resistance to the reservation.…

  9. A Photographic Essay of Apache Clothing, War Charms, and Weapons, Volume 2-Part D.

    ERIC Educational Resources Information Center

    Thompson, Doris; Jacobs, Ben

    As part of a series of guides designed for instruction of American Indian children and youth, this resource guide constitutes a pictorial essay on Apache clothing, war charms, and weaponry. A brief historical introduction is followed by 21 question suggestions for classroom use. Each of the 12 photographic topics is accompanied by a descriptive…

  10. Generalized Instruction following with Pictorial Prompts

    ERIC Educational Resources Information Center

    Phillips, Cara L.; Vollmer, Timothy R.

    2012-01-01

    The benefits of permanent pictorial prompts in enhancing maintenance and generalization are likely dependent on their degree of stimulus control and the extent to which their use is generalized. Although several studies on the use of pictorial prompts have demonstrated their efficacy (e.g., Pierce & Schreibman, 1994; Wacker & Berg, 1983; Wacker,…

  11. Soft tissue attenuation in middle ear on HRCT: Pictorial review

    PubMed Central

    Anbarasu, Arangasamy; Chandrasekaran, Kiruthika; Balakrishnan, Sivasubramanian

    2012-01-01

    Middle ear disease is a common clinical entity; imaging, especially High resolution Computed Tomography (HRCT), plays a crucial role in diagnosis and assessing the disease extent, helping to decide appropriate management. Temporal bone imaging is challenging and involves thorough understanding of the anatomy, especially in relation to HRCT imaging. Most of the middle ear pathologies appear as “soft tissue” on imaging. Careful analysis of the soft tissue on the HRCT is crucial in achieving the right diagnosis; clinical information is essential and the imaging findings need correlation with clinical presentation and otoscopic findings. The purpose of this pictorial essay is to enlist the pathologies that present as soft tissue in middle ear and to provide a structured and practical imaging approach that will serve as a guide for confident reporting in daily practice. PMID:23833422

  12. Primary Essay Tests

    ERIC Educational Resources Information Center

    Veal, L. Ramon; Biesbrock, Edieann F.

    1971-01-01

    Reports the development of an experimental essay test for use with young children based on the now-obsolete STEP Essay Tests. The child's essay on an assigned topic is rated in comparison with previously rated and scaled essays which serve as performance models. (Author)

  13. Mammography technology overview.

    PubMed

    Yohe, C W

    2001-01-01

    As you can see, there are many options in mammography units. This article is not meant to recommend one unit or manufacturer over another, but rather to inform consumers that all units have assets to help technologists acquire the perfect mammogram. This article is meant to make you think about the pros and cons as you consider purchasing new mammography equipment. Though it may seem wise and certainly easier to equip your multiple-unit site(s) with one manufacturer's equipment or even one model, it might truly be wise to have a little variety; this addresses shortcomings of a particular unit. If you provide technologists with a mammography system with which they are comfortable and feel they can address any issues-accommodating disabled patients, patients with breast implants or patients with dense breast tissue-you will see the perfect mammograms you desire. PMID:11431847

  14. Controversies in Screening Mammography.

    PubMed

    Swain, Monique; Jeudy, Myrlene; Pearlman, Mark D

    2016-06-01

    The utility and effectiveness of screening mammography in diagnosing breast cancer at earlier stages and reducing disease-specific mortality remain controversial especially as to when to start and stop routine mammographic screening, and whether mammograms should be performed annually or biennially in average-risk women. This manuscript will analyze the available moderate and high-quality data to analyze both the benefits (lives saved and life-years saved) and inconveniences/harms (additional views, extra biopsies/overdiagnosis, and overtreatment of ductal carcinoma in situ) of different mammography screening guidelines to assist the practitioner in counseling their patients in clinical practice. PMID:27101240

  15. Mammography: What You Need to Know

    MedlinePlus

    ... Products For Consumers Home For Consumers Consumer Updates Mammography: What You Need to Know Share Tweet Linkedin ... Lerner, FDA medical officer in the Division of Mammography Quality Standards, discusses the importance of mammography and ...

  16. Beta Pictoris planet finally imaged?

    NASA Astrophysics Data System (ADS)

    2008-11-01

    A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc. With a projected distance from the star of only 8 times the Earth-Sun distance, this object is most likely the giant planet suspected from the peculiar shape of the disc and the previously observed infall of comets onto the star. It would then be the first image of a planet that is as close to its host star as Saturn is to the Sun. Sharpening Up Jupiter ESO PR Photo 42a/08 Beta Pictoris as seen in infrared light The hot star Beta Pictoris is one of the best-known examples of stars surrounded by a dusty 'debris' disc. Debris discs are composed of dust resulting from collisions among larger bodies like planetary embryos or asteroids. They are a bigger version of the zodiacal dust in our Solar System. Its disc was the first to be imaged -- as early as 1984 -- and remains the best-studied system. Earlier observations showed a warp of the disc, a secondary inclined disc and infalling comets onto the star. "These are indirect, but tell-tale signs that strongly suggest the presence of a massive planet lying between 5 and 10 times the mean Earth-Sun distance from its host star," says team leader Anne-Marie Lagrange. "However, probing the very inner region of the disc, so close to the glowing star, is a most challenging task." In 2003, the French team used the NAOS-CONICA instrument (or NACO [1]), mounted on one of the 8.2 m Unit Telescopes of ESO's Very Large Telescope (VLT), to benefit from both the high image quality provided by the Adaptive Optics system at infrared wavelengths and the good dynamics offered by the detector, in order to study the immediate surroundings of Beta Pictoris. Recently, a member of the team re-analysed the data in a different way to seek the trace of a companion to the star. Infrared wavelengths are indeed very well suited for such searches. "For this, the real challenge

  17. The Formula Essay Reconsidered

    ERIC Educational Resources Information Center

    Haluska, Jan

    2012-01-01

    Bruce Pirie offers the following criticism about formula essays: "What does a five-paragraph essay teach about writing? It teaches that there are rules, and that those rules take the shape of a preordained form, like a cookie-cutter, into which we can pour ideas and expect them to come out well shaped." He goes on to discredit such essays as being…

  18. Multi-detector computed tomography imaging of large airway pathology: A pictorial review

    PubMed Central

    Jugpal, Tejeshwar Singh; Garg, Anju; Sethi, Gulshan Rai; Daga, Mradul Kumar; Kumar, Jyoti

    2015-01-01

    The tracheobronchial tree is a musculo-cartilagenous framework which acts as a conduit to aerate the lungs and consequently the entire body. A large spectrum of pathological conditions can involve the trachea and bronchial airways. These may be congenital anomalies, infections, post-intubation airway injuries, foreign body aspiration or neoplasms involving the airway. Appropriate management of airway disease requires an early and accurate diagnosis. In this pictorial essay review, we will comprehensively describe the various airway pathologies and their imaging findings by multi-detector computed tomography. PMID:26753061

  19. Positron emission mammography imaging

    SciTech Connect

    Moses, William W.

    2003-10-02

    This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and x-ray mammography, as well as PEM and x-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

  20. Mammography accreditation program

    SciTech Connect

    Wilcox, P.

    1993-12-31

    In the mid-1980`s, the movement toward the use of dedicated mammography equipment provided significant improvement in breast cancer detection. However, several studies demonstrated that this change was not sufficient to ensure optimal image quality at a low radiation dose. In particular, the 1985 Nationwide Evaluation of X-ray Trends identified the wide variations in image quality and radiation dose, even from dedicated units. During this time period, the American Cancer Society (ACS) launched its Breast Cancer Awareness Screening Campaign. However, there were concerns about the ability of radiology to respond to the increased demand for optimal screening examinations that would result from the ACS program. To respond to these concerns, the ACS and the American College of Radiology (ACR) established a joint committee on mammography screening in 1986. After much discussion, it was decided to use the ACR Diagnostic Practice Accreditation Program as a model for the development of a mammography accreditation program. However, some constraints were required in order to make the program meet the needs of the ACS. This voluntary, peer review program had to be timely and cost effective. It was determined that the best way to address these needs would be to conduct the program by mail. Finally, by placing emphasis on the educational nature of the program, it would provide an even greater opportunity for improving mammographic quality. The result of this effort was that, almost six years ago, in May 1987, the pilot study for the ACR Mammography Accreditation Program (MAP) began, and in August of that year, the first applications were received. In November 1987, the first 3-year accreditation certificates were awarded.

  1. Patient Dosimetry for Mammography

    SciTech Connect

    Michielsen, K.; Jacobs, J.; Bosmans, H.

    2007-11-26

    We describe a method to conduct a dose study for mammography screening units using established methods and conversion factors. We establish a dose reference curve, giving a dose reference level for different sizes of breasts instead of establishing one reference level for an average size breast so we can compare the results with the achievable and acceptable dose levels from the European guidelines. We notice that, especially for smaller breasts, work is needed to get doses in Belgium below acceptable European levels.

  2. Local shape of pictorial relief

    PubMed Central

    Koenderink, Jan; van Doorn, Andrea; Wagemans, Johan

    2014-01-01

    How is pictorial relief represented in visual awareness? Certainly not as a “depth map,” but perhaps as a map of local surface attitudes (Koenderink & van Doorn, 1995). Here we consider the possibility that observers might instead, or concurrently, represent local surface shape, a geometrical invariant with respect to motions. Observers judge local surface shape, in a picture of a piece of sculpture, on a five-point categorical scale. Categories are cap–ridge–saddle–rut–cup–flat, where “flat” denotes the absence of shape. We find that observers readily perform such a task, with full resolution of a shape index scale (cap–ridge–saddle–rut–cup), and with excellent self-consistency over days. There exist remarkable inter-observer differences. Over a group of 10 naive observers we find that the dispersion of judgments peaks at the saddle category. There may be a relation of this finding to the history of the topic—Alberti's (1827) omission of the saddle category in his purportedly exhaustive catalog of local surface shapes. PMID:25469225

  3. Rank order scaling of pictorial depth

    PubMed Central

    van Doorn, Andrea; Koenderink, Jan; Wagemans, Johan

    2011-01-01

    We address the topic of “pictorial depth” in cases of pictures that are unlike photographic renderings. The most basic measure of “depth” is no doubt that of depth order. We establish depth order through the pairwise depth-comparison method, involving all pairs from a set of 49 fiducial points. The pictorial space for this study was evoked by a capriccio (imaginary landscape) by Francesco Guardi (1712–1793). In such a drawing pictorial space is suggested by the artist through a small set of conventional depth cues. As a result typical Western observers tend to agree largely in their visual awareness when looking at such art. We rank depths for locations that are not on a single surface and far apart in pictorial space. We find that observers resolve about 40 distinct depth layers and agree largely in this. From a previous experiment we have metrical data for the same observers. The rank correlations between the results are high. Perhaps surprisingly, we find no correlation between the number of distinct depth layers and the total metrical depth range. Thus, the relation between subjective magnitude and discrimination threshold fails to hold for pictorial depth. PMID:23145256

  4. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Pictorial, graphic, and... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or... utility or design patent will not affect the registrability of a claim in an original work of...

  5. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Pictorial, graphic, and... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or... utility or design patent will not affect the registrability of a claim in an original work of...

  6. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Pictorial, graphic, and... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or... utility or design patent will not affect the registrability of a claim in an original work of...

  7. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Pictorial, graphic, and... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or... utility or design patent will not affect the registrability of a claim in an original work of...

  8. Introductory pictorial atlas of 3D tomosynthesis.

    PubMed

    Cohen, Stuart L; Margolies, Laurie R; Szabo, Janet R; Patel, Neesha S; Hermann, George

    2014-01-01

    Mammography is an essential tool for early detection of breast cancer. Breast imaging based on three-dimensional digital breast tomosynthesis (DBT) is a new method for breast cancer screening and diagnosis that uses three-dimensional digital images to allow separation of overlapping breast structures, which may allow for improved visualization of potentially significant findings. This article will highlight the utility of DBT as a tool for the detection of breast pathology; it will demonstrate normal findings as well as breast pathology on DBT and two-dimensional conventional mammography. DBT is a very promising modality, which may decrease the false-positive rate of mammography and find additional abnormalities not seen on two-dimensional mammography. PMID:24113063

  9. The Age of β Pictoris

    NASA Astrophysics Data System (ADS)

    Barrado y Navascués, David; Stauffer, John R.; Song, Inseok; Caillault, J.-P.

    1999-08-01

    We have reanalyzed data for the proposed moving group associated with β Pictoris in order to determine if the group (or part of it) is real and, if so, to derive an improved age estimate for β Pic. By using new, more accurate proper motions from PPM and Hipparcos and a few new radial velocities, we conclude that on kinematic grounds, most of the proposed members of the moving group are not, in fact, associated with β Pic. However, two M dwarfs--or three, actually, since one of them is a nearly equal mass binary--have space motions that coincide with that of β Pic to within 1 km s-1 with small error bars. Based on a color-magnitude diagram derived from accurate photometry and Hipparcos parallaxes, these two possible proper-motion companions to β Pic are very young; we derive an age of ~20 Myr by comparison with theoretical tracks from F. D'Antona & I. Mazzitelli. In fact, the proposed β Pic companions comprise two of the three youngest M dwarfs in the sample of 160 dM stars for which we have data. The chromospheric and coronal activities of these two stars also confirm that they are quite young. We argue that the probability that two of the three youngest nearby M dwarfs would accurately share the space motion of β Pic by chance is quite small, and therefore we believe that β Pic and the two M dwarfs (GL 799 and GL 803) were formed together. The estimated age for β Pic is then 20+/-10 Myr, where the uncertainty in the age arises primarily from possible errors in the pre-main-sequence isochrones and in the conversion from color to effective temperature. This young age for β Pic supports the contention that the IR excess for the Vega-like stars is age dependent. Based on observations collected by the Hipparcos satellite.

  10. The Dreaded Essay Exam

    ERIC Educational Resources Information Center

    Sommer, Robert; Sommer, Barbara A.

    2009-01-01

    Surveys in 2 undergraduate psychology classes (N = 86) found that students felt less comfortable taking all-essay tests than taking multiple-choice or short-answer tests. The dominant examination format for students in university and in high school had been multiple-choice tests. We describe measures to encourage essay writing in large classes.…

  11. Automated Essay Scoring

    ERIC Educational Resources Information Center

    Dikli, Semire

    2006-01-01

    The impacts of computers on writing have been widely studied for three decades. Even basic computers functions, i.e. word processing, have been of great assistance to writers in modifying their essays. The research on Automated Essay Scoring (AES) has revealed that computers have the capacity to function as a more effective cognitive tool (Attali,…

  12. Essays on Career Education.

    ERIC Educational Resources Information Center

    Long, Thomas E., Ed.

    The monograph presents a series of essays written by well known educators sharing their perceptions, problems, and projects and documenting some of the practical, philosophical, situational, and theoretical aspects of career education. The essays include: The Case for Career Education, by Kenneth B. Hoyt; Basic Constructs of the School-Based…

  13. Rubric Sorting Astronomy Essays

    NASA Astrophysics Data System (ADS)

    Len, P. M.

    2014-07-01

    Student essays on introductory astronomy exams can be consistently and efficiently graded by a single instructor, or by multiple graders for a large class. This is done by constructing a robust outcome rubric while sorting exams into separate stacks, then checking each stack for consistency. Certain online resources readily provide primary source prompts for writing astronomy exam essay questions.

  14. Comprehension of Disaster Pictorials across Cultures

    ERIC Educational Resources Information Center

    Blees, Gerda J.; Mak, Willem M.

    2012-01-01

    In different countries, the use of pictorial information symbols to convey warnings and instructions is becoming more common. An important reason for this is that people from a variety of cultures can understand graphical symbols. However, symbols developed in one culture may not have the same meaning for people from other cultures. This study…

  15. Ultrasonography of the Kidney: A Pictorial Review

    PubMed Central

    Hansen, Kristoffer Lindskov; Nielsen, Michael Bachmann; Ewertsen, Caroline

    2015-01-01

    Ultrasonography of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys are easily examined, and most pathological changes in the kidneys are distinguishable with ultrasound. In this pictorial review, the most common findings in renal ultrasound are highlighted. PMID:26838799

  16. Does Pictorial Elucidation Foster Recollection of Idioms?

    ERIC Educational Resources Information Center

    Boers, Frank; Piquer Piriz, Ana Maria; Stengers, Helene; Eyckmans, June

    2009-01-01

    Experimental evidence suggests that pictorial elucidation helps learners comprehend and remember the meaning of second language (L2) idioms. In this article we address the question whether it also helps retention of the form of idioms, i.e. their precise lexical composition. In a small-scale experiment, the meaning of English idioms was clarified…

  17. Children's Understanding of Pictorial and Mental Representations.

    ERIC Educational Resources Information Center

    Slaughter, Virginia

    1998-01-01

    Two studies demonstrated dissociation between preschoolers' understanding of pictorial and mental representations. Results showed that false picture tasks were significantly easier than false belief tasks. There was no correlation between performance on the two. Children were trained on false belief, false picture, or number conservation tasks;…

  18. Differential Cognitive Cues in Pictorial Depth Perception.

    ERIC Educational Resources Information Center

    Omari, Issa M.; Cook, Harold

    The experiment described in this report investigates the effects of various cognitive cues in questions asked regarding the relationship of elements in pictorial depth perception. The subjects of this study are 40 third grade Black and Puerto Rican children. They are confronted with four pictures from the Hudson Depth Perception Tests and asked to…

  19. Improving Achievement Via Essay Exams.

    ERIC Educational Resources Information Center

    Milton, Ohmer

    1979-01-01

    The benefits of using essay tests rather than objective tests in professional education programs are discussed. Essay tests offer practice in writing, creativity and formal communications. Guidelines for using and scoring a sample essay test in biology are presented. (BH)

  20. REVIEW: The development of mammography

    NASA Astrophysics Data System (ADS)

    Law, J.

    2006-07-01

    This review traces the development of mammography physics over the last 50 years, concentrating mainly on technological changes and their inter-relations. It has been written for physicists with no specific mammography experience but a general interest in radiology, as much as for those with recent involvement in mammography. Topics covered include industrial film, xerography, intensifying screens, x-ray tube developments, image quality test objects, patient dose and performance checks. Some of these developments were necessary before population screening of healthy women could be considered, while others have resulted from increased opportunities for equipment manufactures which screening programmes created. The standpoint of this review is that of a physicist with long experience in a UK centre where mammography was performed on dedicated equipment well over 40 years ago and where screening has been performed continuously for 30 years.

  1. A circumstellar disk around Beta Pictoris

    NASA Technical Reports Server (NTRS)

    Smith, B. A.; Terrile, R. J.

    1984-01-01

    A circumstellar disk has been observed optically around the fourth-magnitude star Beta Pictoris. First detected in the infrared by the Infrared Astronomy Satellite last year, the disk is seen to extend to more than 400 astronomical units from the star, or more than twice the distance measured in the infrared by the Infrared Astronomy Satellite. The disk is presented to earth almost edge-on and is composed of solid particles in nearly coplanar orbits. The observed change in surface brightness with distance from the star implies that the mass density of the disk falls off with approximately the third power of the radius. Because the circumstellar material is in the form of a highly flattened disk rather than a spherical shell, it is presumed to be associated with planet formation. It seems likely that the system is relatively young and that planet formation either is occurring now around Beta Pictoris or has recently been completed.

  2. Decoding the Inner Disk about - Pictoris

    NASA Astrophysics Data System (ADS)

    Schultz, Alfred

    1996-07-01

    The FOS will be used to study the UV emission linecharacteristics of the inner disk about Beta Pictoris at adistance of 1.3" from the star. Our goal is to investigatethe proposed infall and subsequent sublimation of comet-likebodies into beta Pictoris and to study the composition ofinner disk material. Due to the favorable edge-on orientationof the disk, the gaseous component of the disk has beendetected in absorption. The inner disk gases are excited, dissociated, and ionized by stellar photons. The detection ofemissions from the gaseous disk in the vicinity of the star,possibly cometary in nature (eg., CS 2576 Angstrom, OH 3064Angstrom), would unequivocally establish the sublimation ofcomet-like bodies or possibly volatiles from grains within thecircumstellar disk. Our ultimate goal is to ascertain thecomposition of the inner disk.The GHRS will be employed to acquire the bright targets(alpha and beta Pictoris) followed by slewing the telescope toposition the targets into the FOS aperture. The core of the PSFwill be positioned behind the space separating the FOS 0.5-PAIRapertures. Spectra using the G190H and G270H gratings, spectralinterval 1573 - 3301 Angstrom, will be obtained of both sidesof the disk. Cycle 6 is the last opportunity to assess the spectralcharacteristics of the inner disk material in this wavelength region.

  3. Synchrotron Radiation Mammography: Clinical Experimentation

    SciTech Connect

    Arfelli, Fulvia; Dreossi, Diego; Longo, Renata; Rokvic, Tatjana; Castelli, Edoardo; Abrami, Alessandro; Chenda, Valentina; Menk, Ralf-Hendrik; Quai, Elisa; Tromba, Giuliana; Bregant, Paola; De Guarrini, Fabio; Cova, Maria A.; Tonutti, Maura; Zanconati, Fabrizio

    2007-01-19

    For several years a large variety of in-vitro medical imaging studies were carried out at the SYRMEP (Synchrotron Radiation for Medical Physics) beamline of the synchrotron radiation facility ELETTRA (Trieste, Italy) utilizing phase sensitive imaging techniques. In particular low dose Phase Contrast (PhC) in planar imaging mode and computed tomography were utilized for full field mammography. The results obtained on in-vitro samples at the SYRMEP beamline in PhC breast imaging were so encouraging that a clinical program on a limited number of patients selected by radiologists was launched to validate the improvements of synchrotron radiation in mammography. PhC mammography with conventional screen-film systems is the first step within this project. A digital system is under development for future applications. During the last years the entire beamline has been deeply modified and a medical facility dedicated to in-vivo mammography was constructed. The facility for PhC synchrotron radiation mammography is now operative in patient mode. The system reveals a prominent increase in image quality with respect to conventional mammograms even at lower delivered dose.

  4. Quality Imaging - Comparison of CR Mammography with Screen-Film Mammography

    SciTech Connect

    Gaona, E.; Azorin Nieto, J.; Iran Diaz Gongora, J. A.; Arreola, M.; Casian Castellanos, G.; Perdigon Castaneda, G. M.; Franco Enriquez, J. G.

    2006-09-08

    The aim of this work is a quality imaging comparison of CR mammography images printed to film by a laser printer with screen-film mammography. A Giotto and Elscintec dedicated mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in screen-film mammography. Four CR mammography units from two different manufacturers and three dedicated x-ray mammography units with fully automatic exposure and a nominal large focal spot size of 0.3 mm were used for the image acquisition of phantoms in CR mammography. The tests quality image included an assessment of system resolution, scoring phantom images, Artifacts, mean optical density and density difference (contrast). In this study, screen-film mammography with a quality control program offers a significantly greater level of quality image relative to CR mammography images printed on film.

  5. The Effectiveness of Teaching Science with Pictorial Analogies.

    ERIC Educational Resources Information Center

    Lin, Huann-shyang; And Others

    1996-01-01

    This study uses a conceptual problem-solving test to investigate the effect of a series of pictorial analogies on the concepts of density, pressure, and atmospheric pressure in Year Eight classrooms. Findings indicate that students taught with the pictorial analogies scored significantly higher than their counterparts. Low achievers were the most…

  6. Social Interactions Sparked by Pictorial Warnings on Cigarette Packs

    PubMed Central

    Hall, Marissa G.; Peebles, Kathryn; Bach, Laura E.; Noar, Seth M.; Ribisl, Kurt M.; Brewer, Noel T.

    2015-01-01

    The Message Impact Framework suggests that social interactions may offer smokers the opportunity to process pictorial warnings on cigarette packs more deeply. We aimed to describe adult smokers’ social interactions about pictorial cigarette pack warnings in two longitudinal pilot studies. In Pilot Study 1, 30 smokers used cigarette packs with one of nine pictorial warnings for two weeks. In Pilot Study 2, 46 smokers used cigarette packs with one of five pictorial warnings for four weeks. Nearly all smokers (97%/96% in Pilot Study 1/2) talked about the warnings with other people, with the most common people being friends (67%/87%) and spouses/significant others (34%/42%). Pilot Study 2 found that 26% of smokers talked about the warnings with strangers. Discussions about the health effects of smoking and quitting smoking were more frequent during the first week of exposure to pictorial warnings than in the week prior to beginning the study (both p < 0.05). Pictorial warnings sparked social interactions about the warnings, the health effects of smoking, and quitting smoking, indicating that pictorial warnings may act as a social intervention reaching beyond the individual. Future research should examine social interactions as a potential mediator of the impact of pictorial warnings on smoking behavior. PMID:26506363

  7. "Mid-Week Pictorial": Pioneer American Photojournalism Magazine.

    ERIC Educational Resources Information Center

    Kenney, Keith

    In 1914 (22 years before the inception of "Life" magazine), the "New York Times" began publishing "Mid-Week Pictorial" to absorb a flood of war pictures pouring in from Europe. Several sociological and technological forces shaped "Mid-Week Pictorial" as a pioneer of American photojournalism magazines, including the development of the halftone…

  8. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... sculptural works. 202.10 Section 202.10 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or sculptural work, the work must embody some creative authorship in its delineation or form. The...

  9. Elementary School Students' Perceptions of Technology in their Pictorial Representations

    ERIC Educational Resources Information Center

    Eristi, Suzan Duygu; Kurt, Adile Askim

    2011-01-01

    The current study aimed to reveal elementary school students' perceptions of technology through their pictorial representations and their written expressions based on their pictorial representations. Content analysis based on the qualitative research method along with art-based inquiry was applied. The "coding system for the concepts revealed from…

  10. Social Interactions Sparked by Pictorial Warnings on Cigarette Packs.

    PubMed

    Hall, Marissa G; Peebles, Kathryn; Bach, Laura E; Noar, Seth M; Ribisl, Kurt M; Brewer, Noel T

    2015-10-01

    The Message Impact Framework suggests that social interactions may offer smokers the opportunity to process pictorial warnings on cigarette packs more deeply. We aimed to describe adult smokers' social interactions about pictorial cigarette pack warnings in two longitudinal pilot studies. In Pilot Study 1, 30 smokers used cigarette packs with one of nine pictorial warnings for two weeks. In Pilot Study 2, 46 smokers used cigarette packs with one of five pictorial warnings for four weeks. Nearly all smokers (97%/96% in Pilot Study 1/2) talked about the warnings with other people, with the most common people being friends (67%/87%) and spouses/significant others (34%/42%). Pilot Study 2 found that 26% of smokers talked about the warnings with strangers. Discussions about the health effects of smoking and quitting smoking were more frequent during the first week of exposure to pictorial warnings than in the week prior to beginning the study (both p < 0.05). Pictorial warnings sparked social interactions about the warnings, the health effects of smoking, and quitting smoking, indicating that pictorial warnings may act as a social intervention reaching beyond the individual. Future research should examine social interactions as a potential mediator of the impact of pictorial warnings on smoking behavior. PMID:26506363

  11. Essays on symmetry

    NASA Astrophysics Data System (ADS)

    Ismael, Jenann Tareq

    1997-04-01

    Structures of many different sorts arise in physics, e.g., the concrete structures of material bodies, the structure exemplified by the spatiotemporal configuration of a set of bodies, the structures of more abstract objects like states, state-spaces, laws, and so on. To each structure of any of these types there corresponds a set of transformations which map it onto itself. These are its symmetries. Increasingly ubiquitous in theoretical discussions in physics, the notion of symmetry is also at the root of some time-worn philosophical debates. This dissertation consists of a set of essays on topics drawn from places where the two fields overlap. The first essay is an informal introduction to the mathematical study of symmetry. The second essay defends a famous principle of Pierre Curie which states that the symmetries of a cause are always symmetries of its effect. The third essay takes up the case of reflection in space in the context of a controversy stemming from one of Kant's early arguments for the substantivality of space. The fourth essay is a discussion of the general conditions under which an asymmetry in a phenomenon suggests an asymmetry in the laws which govern it. The case of reflection in time-specifically, the theoretical strategy used in statistical mechanics to subsume the time-asymmetric phenomena of Thermodynamics under the time-symmetric classical dynamical laws-is used to illustrate the general points. The philosophical heart of the thesis lies in its fifth essay. Here a somewhat novel way of conceiving scientific theorizing is articulated, one suggested by the abstract mathematical perspective of symmetry.

  12. Document image database indexing with pictorial dictionary

    NASA Astrophysics Data System (ADS)

    Akbari, Mohammad; Azimi, Reza

    2010-02-01

    In this paper we introduce a new approach for information retrieval from Persian document image database without using Optical Character Recognition (OCR).At first an attribute called subword upper contour label is defined then, a pictorial dictionary is constructed based on this attribute for the subwords. By this approach we address two issues in document image retrieval: keyword spotting and retrieval according to the document similarities. The proposed methods have been evaluated on a Persian document image database. The results have proved the ability of this approach in document image information retrieval.

  13. A search for Beta Pictoris analogs

    NASA Technical Reports Server (NTRS)

    Cheng, Kwang-Ping; Grady, C. A.; Bruhweiler, Frederick C.; Kondo, Yoji

    1990-01-01

    The results are presented of the survey of known shell stars detected by the Infrared Astronomy Satellite (IRAS) at sufficient bandpasses to permit evaluation of the nature of the infrared excess, and having archival International Ultraviolet Explorer (IUE) high dispersion spectra suitable for identifying stars with infalling circumstellar plasma. Detection of infall in shell stars with infrared signatures of circumstellar dust is described. One star which shows infalling plasma, but apparently no circumstellar dust is described. The implications for the understanding of Beta Pictoris and similar systems are discussed.

  14. Marking Advanced Essays

    ERIC Educational Resources Information Center

    Donley, Michael

    1978-01-01

    A list of points to aid essay writers is suggested as the basis of a marking system for the teacher of English as a foreign language. The checklist, obtained from a book on higher education by Ruth Beard, can be adapted to the English as a foreign language situation. (SW)

  15. A Personal Essay.

    ERIC Educational Resources Information Center

    Zawacki, Terry Myers

    The personal essay does not rely on the straight, even rows of a carefully laid out vegetable garden, on strings pulled tight to connect beginnings to ends. Instead it meanders, pulls from here and there, thinks out loud, asks questions, and proceeds leisurely through disconnections to make connections, as an ever-changing flower garden in which…

  16. Essays on Character & Opportunity

    ERIC Educational Resources Information Center

    Center on Children and Families at Brookings, 2014

    2014-01-01

    These essays provide richer set of writings on the philosophical, empirical and practical issues raised by a focus on character, and in particular its relationship to questions of opportunity. Each one is an intellectual pemmican: sharp and to the point. Two scholars draw attention to the gendered nature of character formation (Segal and Lexmond);…

  17. Rethinking the Argumentative Essay

    ERIC Educational Resources Information Center

    Schneer, David

    2014-01-01

    This article investigates the construction of the argumentative essay as it is commonly presented in academic writing textbooks and classrooms for English language learners. The author first examines the traditional three-stage structure (thesis-argument-conclusion) and then problematizes it within a genre-based approach to academic writing. He…

  18. The Centennial Essay.

    ERIC Educational Resources Information Center

    Keeshan, Bob

    1991-01-01

    In this essay, the star of "Captain Kangaroo" points out that more than 20 percent of America's children live below the poverty line. School boards, administrators, and teachers need to make a commitment to address the needs of the whole child. Schools have an opportunity to play a critical role in saving our children. (MLF)

  19. The psychosocial consequences of mammography.

    PubMed

    Rimer, B K; Bluman, L G

    1997-01-01

    Increasing numbers of mammograms being performed in the United States will be accompanied inevitably by an increasing number of false positives. According to reliable estimates from a survey of radiology facilities, U.S. women in their forties experience close to one million false positive mammograms every year. To determine the impact of false positive mammograms and the broader psychological impact of mammography, we conducted literature searches of Medline, CancerLit, and PsycInfo. We identified nine studies examining the impact of false positive mammograms. Most found short-term increases in such psychological measures as anxiety, distress, and intrusive thoughts. One study found substantial effects on these measures three months after an abnormal mammogram. Another study found an 18-month impact on anxiety. Few studies have used behavioral outcomes, but one reported overpractice of breast self-exam among women who had received false positive results. Another found no reduction in adherence to mammography among women who have had an abnormal test. The more general mammography literature suggests that many women are anxious about mammography before the exam; women with lower levels of education, African Americans, and women with a family history of breast cancer may be more vulnerable to distress. Unfortunately, this literature suffers major limitations, such as small sample sizes, inconsistent and sometimes inappropriate measures, variations in the time frames for measurement, few studies with women aged 40-49, and a paucity of U.S. research. More research is needed to characterize at-risk women and to test interventions designed to reduce the negative impact of abnormal mammograms. Improved communication is also needed throughout the entire mammography process. PMID:9709289

  20. Writing Your College Application Essay.

    ERIC Educational Resources Information Center

    Pett, Stephen

    1999-01-01

    Advice to American Indian students on writing a college application essay focuses on conveying an honest portrayal of significant aspects of their lives. Distinctive stories grounded in Native American experience are likely to catch the interest of the admissions officer. A sample essay and representative essay questions are included. (SV)

  1. Breast Cancer and Mammography: Summary of the Educational Impact of a Low-Cost Mammography Program.

    ERIC Educational Resources Information Center

    Gresham, Louise S.; And Others

    1988-01-01

    A mammography public education program which used newspaper press releases, local talk shows, news segments, and announcements, flyers, advertisements, and presentations to companies and select populations increased public awareness and decreased misconceptions about mammography. (CB)

  2. Falling Evaporating Bodies around Beta Pictoris

    NASA Astrophysics Data System (ADS)

    Beust, H.

    2014-09-01

    The edge-on orientation of the beta Pictoris disk as viewed from the Earth enabled the detection of its gaseous counterpart by absorption spectroscopy. This was done as early as 1985 (Vidal-Madjar et al.). Surprisingly, the detected circumstellar absorptions in Ca II, Mg II, etc... lines appeared to often present, next to a central stable component, highly time- variable additional features, Doppler shifted by a few tens, sometimes up to a few hundreds km/s. A huge sample of such features, sometimes presenting very different shapes, has been recorded since that time, especially in the last 10 years thanks to the survey by the HARPS spectrograph. Modeling work in the late 1980's led to propose that these transient spectral events could be due to star-grazing, evaporating planetesimals arising from the disk, that cross the line of sight close to periastron. The absorption components would be due to the gaseous coma around the object, and the Doppler shift to the projection of its velocity onto the line of sight. This model has been thus termed the ÓFalling Evaporating BodiesÓ (FEB) model. Detailed modeling and simulations (Beust et al. 1990, 1996; Karmann et al. 2001, 2003; Fernandez et al. 2006) helped to constrain the physics of the phenomenon and to specify the characteristics of the suspected FEBs, which number may be as large as several hundreds per year. The large number of available data enabled a statistical approach of these events and of their characteristics. It rapidly turned out that the infall of FEBs towards beta Pictoris from the disk was not isotropic. This raised the issue of the dynamical origin of this phenomenon. In the late 1990's, Beust & Morbidelli (1996, 2000) proposed that FEBs could originate from 4:1 and 3:1 mean-motion resonances with a hypothetical giant planet, and fall towards the star thanks to a drastic increase of their eccentricities thanks to the resonances. Exhaustive dynamical simulations led to propose that the suspected

  3. Neonatal head ultrasound: systematic approach to congenital Central Nervous System anomalies. A pictorial essay.

    PubMed

    Yoon, Hye-Kyung; Cho, Seong Whi

    2016-09-01

    Brain ultrasound is widely used for the screening of prematurely born babies. Although the best imaging modality for the central nervous system anomaly is brain MRI, the first imaging study in the post-natal period is brain ultrasonography in most cases. Anomalies could be found incidentally on screening ultrasound, or in those cases already suspected on prenatal ultrasound. In order not to miss congenital structural abnormalities of the brain on screening ultrasound, systematic approaches would be very helpful. The ventricles and sylvian fissures are very important structures to suspect central nervous system anomalies: they are symmetric structures so we should look for any asymmetry or maldevelopment. And then, on sagittal images, the midline structures including the corpus callosum and cerebellar vermis should be observed carefully. Finally, we should look for any abnormality in gyration or cortical development. Skull defect with herniation of intracranial contents, a spectrum of encephalo-meningocele, could be also identified on ultrasound. Congenital infections such as cytomegalovirus infection may show ventriculomegaly and malformation of the cortical development on imaging studies. PMID:27622417

  4. Amplatzer vascular plug as an embolic agent in different vascular pathologies: A pictorial essay.

    PubMed

    Tresley, Jonathan; Bhatia, Shivank; Kably, Issam; Poozhikunnath Mohan, Prasoon; Salsamendi, Jason; Narayanan, Govindarajan

    2016-01-01

    The Amplatzer Vascular Plug (AVP) is a cylindrical plug made of self-expanding nitinol wire mesh with precise delivery control, which can be used for a variety of vascular pathologies. An AVP is an ideal vascular occlusion device particularly in high-flow vessels, where there is high risk of migration and systemic embolization with traditional occlusion devices. We performed 28 embolizations using the AVP from 2009 to 2014 and achieved complete occlusion without complications. PMID:27413276

  5. Imaging of tarsal navicular stress injury with a focus on MRI: A pictorial essay.

    PubMed

    Harris, Guy; Harris, Craig

    2016-06-01

    Predominantly diagnosed in athletes, stress fracture of the tarsal navicular is becoming increasingly recognised by clinicians as a cause of midfoot pain. Delayed diagnosis can increase the significant morbidity associated with this condition. Consequently the role of MRI is increasing, given the potential to identify a stress reaction in the navicular prior to the development of a discrete stress fracture. It is necessary for radiologists to be familiar with the typical and atypical appearances of this important condition. PMID:26748622

  6. [The role of the interventional radiologist in central venous catheter dysfunction (pictorial essay)].

    PubMed

    Altunel, Ekrem; Oran, Ismail; Parildar, Mustafa; Memiş, Ahmet

    2004-03-01

    Failure to aspirate blood from the lumen of venous catheters, inadequate blood flow and/or high resistance pressures during hemodialysis were accepted as catheter dysfunction. Other correctable problems such as residual lumen thrombus, external fibrin catheter sheath or malpositioned catheter tip were identified by contrast injection. Catheter malpositions were corrected by snare-mediated catheter repositioning or by exchange of the catheter over a guidewire. Catheters of inadequate length were exchanged over a guidewire to the appropriate position or replaced. Treatment of fibrin sheath formation included fibrin sheath stripping, guidewire catheter exchange, and urokinase infusion. Early catheter dysfunction is frequently due to mechanical problems such as inadequate positioning, kinking, or constriction. Delayed dysfunction usually results from thrombus formation, either within the lumen, around the catheter ("fibrin sleeve"), or in the host vein. In the management of catheter malfunctions and complications, interventional radiological techniques are safe and effective alternatives to standard surgical techniques. PMID:15054708

  7. Multislice CT virtual intravascular endoscopy of aortic dissection: A pictorial essay

    PubMed Central

    Sun, Zhonghua; Cao, Yan

    2010-01-01

    AIM: To present our experience of using 3D virtual intravascular endoscopy (VIE) to characterize and evaluate the intraluminal appearances of aortic dissection. METHODS: Ten patients with known aortic dissection underwent dual-source computed tomography angiography and were included in the study. In addition to 2D axial and multiplanar reformatted images as well as 3D reconstructions, VIE images were created in each patient to demonstrate intraluminal views of the aorta and its branches, origin of artery branches and artery branch involvement by aortic dissection. RESULTS: Stanford A dissection was found in 8 patients and B dissection in the remaining 2 patients. VIE images were successfully generated in all of the patients with excellent visualization of the normal anatomical structures, intimal flap and intimal entrance tear, communication between true and false lumens, as well as assessment of the extent of aortic dissection. CONCLUSION: Our preliminary experience suggests that VIE could be used as a complementary tool to assist radiologists accurately evaluate aortic dissection so that better patient management can be achieved. PMID:21179312

  8. Hepatobiliary and pancreatic ascariasis-sonographic pictorial essay on four pediatric cases with acute biliary colic.

    PubMed

    Lynser, Donboklang; Marbaniang, Evarisalin

    2016-04-01

    Hepatobiliary and pancreatic ascariasis occur due to migration of the round worm ascaris lumbricoides through the bile duct orifice finally reaching the common bile duct, main pancreatic duct, intrahepatic ducts or gallbladder. These resulted in acute epigastric and right hypochondriac region colicky pain. Ultrasound is the investigation of choice in hepatobiliary ascariasis. We present here sonographic images on four pediatric patients with acute biliary colic. PMID:26690772

  9. Congenital and Acquired Abnormalities of the Corpus Callosum: A Pictorial Essay

    PubMed Central

    Krupa, Katarzyna; Bekiesinska-Figatowska, Monika

    2013-01-01

    The purpose of this review is to illustrate the wide spectrum of lesions in the corpus callosum, both congenital and acquired: developmental abnormalities, phakomatoses, neurometabolic disorders, demyelinating diseases, infection and inflammation, vascular lesions, neoplasms, traumatic and iatrogenic injury, and others. Cases include fetuses, children, and adults with rich iconography from the authors' own archive. PMID:24027754

  10. MRI evaluation of pathologies affecting the corpus callosum: A pictorial essay

    PubMed Central

    Kazi, Aamish Z; Joshi, Priscilla C; Kelkar, Abhimanyu B; Mahajan, Mangal S; Ghawate, Amit S

    2013-01-01

    The corpus callosum is a midline cerebral structure and has a unique embryological development pattern. In this article, we describe the pathophysiology and present imaging findings of various typical/atypical conditions affecting the corpus callosum. Since many of these pathologies have characteristic appearances on magnetic resonance imaging (MRI) and their therapeutic approaches are poles apart, ranging from medical to surgical, the neuroradiologist should be well aware of them. PMID:24604936

  11. Pictorial Essay: Exploring Strategies to Develop More Inclusive Approaches to Actor-Training

    ERIC Educational Resources Information Center

    Aita, Sean

    2012-01-01

    In 1975 a new definition of disability, challenging the conventional medical model, was proposed by the Union of the Physically Impaired Against Segregation (UPIAS) and the Disability Alliance. Subsequently extended to cover all impairments, this definition considers disability to be the "disadvantage or restriction caused by a contemporary social…

  12. Xanthogranulomatous cholecystitis: sonographic and CT features and differentiation from gallbladder carcinoma: a pictorial essay.

    PubMed

    Shetty, Gurucharan S; Abbey, Pooja; Prabhu, Shailesh M; Narula, Mahender K; Anand, Rama

    2012-07-01

    The imaging features of xanthogranulomatous cholecystitis closely resemble those of gallbladder carcinoma, especially those of the wall-thickening variety. There is an overlap between these two conditions with respect to the clinical features and certain imaging findings. However, certain finer details like the presence of intramural hypoattenuating nodules and the type of mucosal enhancement may help to differentiate these two conditions. In this article, we have highlighted some of these imaging features. The importance of making an accurate diagnosis lies in the significant difference between the prognosis and the surgical management of the two disease entities. PMID:22488612

  13. Review of ultrasound appearance in inflammatory breast cancer: A pictorial essay.

    PubMed

    Abeywardhana, Dilupani Y; Nascimento, Vinicius C; Dissanayake, Deepthi; Taylor, Donna; Metcalf, Cecily; Saunders, Christobel; Wylie, Elizabeth

    2016-02-01

    Inflammatory breast cancer (IBC) is a rare malignancy accounting for 1-2% of breast cancers. It has an aggressive clinical presentation and poor prognosis. The sonographic findings in 41 patients with a clinical diagnosis of IBC and biopsy-proven breast malignancy are presented in this study. The most common finding was the presence of skin thickening (92%). Multiple small anechoic spaces within the dermis, correlating with the presence of dermal lymphatic invasion by tumour emboli on histopathology were noted in approximately one-third of cases. Other sonographic findings included single or multiple masses, parenchymal oedema, axillary lymphadenopathy, echogenic foci consistent with microcalcifications and increased vascularity. PMID:26631841

  14. Cysts and cystic-appearing lesions of the knee: A pictorial essay

    PubMed Central

    Telischak, Nicholas A; Wu, Jim S; Eisenberg, Ronald L

    2014-01-01

    Cysts and cystic-appearing lesions around the knee are common and can be divided into true cysts (synovial cysts, bursae, ganglia, and meniscal cysts) and lesions that mimic cysts (hematomas, seromas, abscesses, vascular lesions, and neoplasms). The specific anatomic location of the cystic lesion often permits the correct diagnosis. In difficult cases, identifying a cystic mass in an atypical location and/or visualizing internal solid contrast enhancement on magnetic resonance imaging (MRI) should raise concern for a neoplasm and the need for further evaluation and intervention. PMID:25024531

  15. Amplatzer vascular plug as an embolic agent in different vascular pathologies: A pictorial essay

    PubMed Central

    Tresley, Jonathan; Bhatia, Shivank; Kably, Issam; Poozhikunnath Mohan, Prasoon; Salsamendi, Jason; Narayanan, Govindarajan

    2016-01-01

    The Amplatzer Vascular Plug (AVP) is a cylindrical plug made of self-expanding nitinol wire mesh with precise delivery control, which can be used for a variety of vascular pathologies. An AVP is an ideal vascular occlusion device particularly in high-flow vessels, where there is high risk of migration and systemic embolization with traditional occlusion devices. We performed 28 embolizations using the AVP from 2009 to 2014 and achieved complete occlusion without complications. PMID:27413276

  16. Sonographic Tracking of the Lower Limb Peripheral Nerves: A Pictorial Essay and Video Demonstration.

    PubMed

    Hung, Chen-Yu; Hsiao, Ming-Yen; Özçakar, Levent; Chang, Ke-Vin; Wu, Chueh-Hung; Wang, Tyng-Guey; Chen, Wen-Shiang

    2016-09-01

    Compared with the upper limbs, sonographic tracking of peripheral nerves in the lower limbs is more challenging. The overlying muscles are larger, hindering visualization of the deeply embedded nerves by using a linear transducer. The use of a curvilinear transducer-providing an extended view with better penetration for the field of interest-may be useful for scanning the nerves in the hip and thigh. Application of the Doppler mode helps localization of the target nerve by identifying the accompanying vessels. Aiming to demonstrate the relevant tracking techniques, the present article comprises a series of ultrasound images and videos showing how to scan the nerves in the lower limb, that is, femoral, obturator, pudendal, lateral femoral cutaneous, sciatic, saphenous, sural, tibial, and peroneal nerves. PMID:26945217

  17. Pictorial essay of developmental thyroid anomalies identified by Technetium thyroid scintigraphy

    PubMed Central

    Subramanyam, Padma; Palaniswamy, Shanmuga Sundaram

    2015-01-01

    Developmental anomalies and anatomic variations of the thyroid gland in the general population with no known thyroid dysfunction usually goes unnoticed. Only those patients with neck swellings, incidentally detected hypo or hyperthyroidism, and those with a maternal history of hypothyroidism undergo screening for the thyroid gland. Neck ultrasound and scintigraphic techniques are the imaging tools routinely used to identify these anomalies. We present interesting technetium (Pertechnetate and sestaMIBI) scintigraphic images of adults and children who presented to our department with thyroid dysfunction showing developmental anomalies of the thyroid. PMID:26430316

  18. Multimodality imaging following 90Y radioembolization: a comprehensive review and pictorial essay.

    PubMed

    Atassi, Bassel; Bangash, Affaan K; Bahrani, Ammar; Pizzi, Giuseppi; Lewandowski, Robert J; Ryu, Robert K; Sato, Kent T; Gates, Vanessa L; Mulcahy, Mary F; Kulik, Laura; Miller, Frank; Yaghmai, Vahid; Murthy, Ravi; Larson, Andrew; Omary, Reed A; Salem, Riad

    2008-01-01

    Radioembolization with yttrium 90 (90Y) microspheres represents an emerging transarterial therapy for the treatment of liver malignancies that continues to generate interest in the medical community. The classic indication of treatment response is a reduction in tumor size; however, parenchymal changes (eg, necrosis, lack of enhancement, specific findings at positron emission tomography and functional magnetic resonance imaging) and other benign findings (pleural effusions, perivascular edema, contralateral hypertrophy, ring enhancement, perihepatic fluid, fibrosis) may occur following treatment, requiring proper image interpretation. With classic imaging findings and surrogates (time to progression, duration of response, disease-free interval), response rates range from 20% to 80% in patients treated for hepatocellular carcinoma or metastatic disease to the liver. Complications of 90Y radioembolization include cholecystitis, abscess, and bilomas and should be recognized early in the imaging follow-up of these patients. Radiologists who are involved in the posttreatment assessment of patients undergoing 90Y radioembolization should be familiar with the imaging findings and potential imaging pitfalls associated with this therapy. PMID:18203932

  19. Imaging features of primary tumors of the spine: A pictorial essay

    PubMed Central

    Patnaik, Sujata; Jyotsnarani, Y; Uppin, Shantiveer G; Susarla, Rammurti

    2016-01-01

    Primary tumors of spine are rare accounting for less than 5% of new bone tumors diagnosed every year. These tumors may exhibit characteristic imaging features that can help in early diagnosis and improved prognosis. Plasmacytoma/multiple myeloma and lymphoproliferative tumors are the most common malignant primary spinal tumors. Hemangioma is the most common benign tumor of the spine. Computed tomography is useful to assess tumor matrix and osseous change. Magnetic resonance is useful to study associated soft tissue extension, marrow infiltration, and intraspinal extension. Confusing one tumor with the other based on only imaging findings is not uncommon. However, radiologic manifestations of these tumors need to be correlated with the age, sex, location, and presentation to arrive at a close clinical diagnosis. PMID:27413280

  20. Are Irregular Hypoechoic Breast Masses on Ultrasound Always Malignancies?: A Pictorial Essay

    PubMed Central

    Kim, Youe Ree; Kim, Hun Soo

    2015-01-01

    Irregular hypoechoic masses in the breast do not always indicate malignancies. Many benign breast diseases present with irregular hypoechoic masses that can mimic carcinoma on ultrasonography. Some of these diseases such as inflammation and trauma-related breast lesions could be suspected from a patient's symptoms and personal history. Careful ultrasonographic examination and biopsy could help to differentiate these from malignancies. PMID:26576116

  1. High-resolution computed tomography and histopathological findings in hypersensitivity pneumonitis: a pictorial essay*

    PubMed Central

    Torres, Pedro Paulo Teixeira e Silva; Moreira, Marise Amaral Rebouças; Silva, Daniela Graner Schuwartz Tannus; da Gama, Roberta Rodrigues Monteiro; Sugita, Denis Masashi; Moreira, Maria Auxiliadora do Carmo

    2016-01-01

    Hypersensitivity pneumonitis is a diffuse interstitial and granulomatous lung disease caused by the inhalation of any one of a number of antigens. The objective of this study was to illustrate the spectrum of abnormalities in high-resolution computed tomography and histopathological findings related to hypersensitivity pneumonitis. We retrospectively evaluated patients who had been diagnosed with hypersensitivity pneumonitis (on the basis of clinical-radiological or clinical-radiological-pathological correlations) and had undergone lung biopsy. Hypersensitivity pneumonitis is clinically divided into acute, subacute, and chronic forms; high-resolution computed tomography findings correlate with the time of exposure; and the two occasionally overlap. In the subacute form, centrilobular micronodules, ground-glass opacities, and air trapping are characteristic high-resolution computed tomography findings, whereas histopathology shows lymphocytic inflammatory infiltrates, bronchiolitis, variable degrees of organizing pneumonia, and giant cells. In the chronic form, high-resolution computed tomography shows traction bronchiectasis, honeycombing, and lung fibrosis, the last also being seen in the biopsy sample. A definitive diagnosis of hypersensitivity pneumonitis can be made only through a multidisciplinary approach, by correlating clinical findings, exposure history, high-resolution computed tomography findings, and lung biopsy findings. PMID:27141134

  2. Physician and dictator: a pictorial essay on Luigi Carlo Farini (1812-1866) in his homeland.

    PubMed

    Borghi, Luca

    2013-01-01

    Luigi Carlo Farini (1812-1866) was one of the leading figures in the Italian unification, the Risorgimento. As a physician he always took care of the health problems of its people with a broadminded attitude, promoting for example extensive campaigns of Jennerian vaccination or experimenting the effects of electricity on tetanus. As a political leader - he was proclaimed "Dictator" in 1859 - he made possible the annexation of the Adriatic regions of Emilia and Romagna to the Kingdom of Vittorio Emanuele II of Savoy that later, in March 1861, was to become the new Kingdom of Italy. This article, in connection with the project "Himetop - The History of Medicine Topographical Database", offers a brief photographic survey of the location and condition of the monuments and memories of the physician-dictator in his homeland, two hundred years after his birth. Not only the tormented history of his monument in Ravenna, but also his birthplace, hospital, tomb, etc., testify that Farini's memory is well preserved among the people he served as a physician and as a statesman. PMID:24304112

  3. A practical primer on PI-RADS version 2: a pictorial essay.

    PubMed

    Horn, Gary Lloyd; Hahn, Peter Florin; Tabatabaei, Shahin; Harisinghani, Mukesh

    2016-05-01

    Multiparametric magnetic resonance imaging has become an established method for evaluating the prostate for clinically significant prostate adenocarcinoma. Criteria have been developed for categorizing MRI findings, the most frequently used of which is the PI-RADS system. The PI-RADS V2 document provides separate image interpretation and clinical grading sections. Within this article we give an overview of the integrated, algorithmic way, we approach prostate MRI, show images corresponding to each PI-RADS category, and provide several illustrative cases. PMID:26984751

  4. High-resolution computed tomography and histopathological findings in hypersensitivity pneumonitis: a pictorial essay.

    PubMed

    Torres, Pedro Paulo Teixeira E Silva; Moreira, Marise Amaral Rebouças; Silva, Daniela Graner Schuwartz Tannus; da Gama, Roberta Rodrigues Monteiro; Sugita, Denis Masashi; Moreira, Maria Auxiliadora do Carmo

    2016-01-01

    Hypersensitivity pneumonitis is a diffuse interstitial and granulomatous lung disease caused by the inhalation of any one of a number of antigens. The objective of this study was to illustrate the spectrum of abnormalities in high-resolution computed tomography and histopathological findings related to hypersensitivity pneumonitis. We retrospectively evaluated patients who had been diagnosed with hypersensitivity pneumonitis (on the basis of clinical-radiological or clinical-radiological-pathological correlations) and had undergone lung biopsy. Hypersensitivity pneumonitis is clinically divided into acute, subacute, and chronic forms; high-resolution computed tomography findings correlate with the time of exposure; and the two occasionally overlap. In the subacute form, centrilobular micronodules, ground-glass opacities, and air trapping are characteristic high-resolution computed tomography findings, whereas histopathology shows lymphocytic inflammatory infiltrates, bronchiolitis, variable degrees of organizing pneumonia, and giant cells. In the chronic form, high-resolution computed tomography shows traction bronchiectasis, honeycombing, and lung fibrosis, the last also being seen in the biopsy sample. A definitive diagnosis of hypersensitivity pneumonitis can be made only through a multidisciplinary approach, by correlating clinical findings, exposure history, high-resolution computed tomography findings, and lung biopsy findings. PMID:27141134

  5. Congenital anatomic variants of the kidney and ureter: a pictorial essay.

    PubMed

    Srinivas, M R; Adarsh, K M; Jeeson, Riya; Ashwini, C; Nagaraj, B R

    2016-03-01

    Congenital renal parenchymal and pelvicalyceal abnormalities have a wide spectrum. Most of them are asymptomatic, like that of ectopia, cross fused kidney, horseshoe kidney, etc., while a few of them become complicated, leading to renal failure and death. It is very important for the radiologist to identify these anatomic variants and guide the clinicians for surgical and therapeutic procedures. Cross-sectional imaging with a volume rendered technique/maximum intensity projection has overcome ultrasonography and IVU for identification and interpretation of some of these variants. PMID:26747433

  6. What Makes a Good Mammography Image?

    SciTech Connect

    Brandan, Maria-Ester

    2007-11-26

    The early detection of breast cancer requires a high quality image, which is provided by mammography. The main indicators of technical image quality, contrast, spatial resolution, noise and absence of artifacts, are described, as well as the elements responsible for their values in a mammography unit. Since screening mammography is applied to asymptomatic subjects, the optimization of the imparted dose compatible with required image quality is of importance.

  7. Digital mammography: current state and future aspects.

    PubMed

    Fischer, U; Hermann, K P; Baum, F

    2006-01-01

    The introduction of digital technique in mammography has been the last step in completing the process of digitalization in diagnostic imaging. Meanwhile, some different digital techniques as well as a couple of different digital mammography systems were developed and have already been available for some years. In this review article, the relevant data of key studies are reported, the current status is defined, and perspectives of digital mammography are described. PMID:16132935

  8. Tracking debris disks within the Beta Pictoris Moving Group

    NASA Astrophysics Data System (ADS)

    Debes, J.

    2014-09-01

    Beta Pictoris represents a stunning example of a young planetary system with a debris disk, moving through local space with a host of other co-eval companion stars. These fellow travelers provide additional understanding for placing the Beta Pictoris disk into a proper context with regards to planet formation throughout the galaxy and our own Solar System. I will review the members of the Beta Pictoris moving group and catalog the latest results regarding the presence and understanding of debris disks around these other systems. Since these stars are close and very young, they represent an excellent opportunity for understanding the structure, composition, and grain properties of debris disks.

  9. Pilot performance with a simulated ILS independence pictorial display

    NASA Technical Reports Server (NTRS)

    Palmer, E.; Wempe, T.

    1972-01-01

    As part of a general investigation of the effectiveness of pictorial displays for manual control and monitoring of aircraft approaches and landings, a simulator study was conducted in which pilot performance with three pictorial displays was evaluated. These displays differed in the type of guidance symbology added to the basic perspective runway display. The effect of decreased resolution and update rate of the runway image on pilot performance was also determined. The results indicate that for pictorial displays with added guidance symbology, there was a marked improvement in pilot performance compared to results of a previous study in which the display consisted of only a runway image and aircraft attitude.

  10. Essays in microeconomics

    NASA Astrophysics Data System (ADS)

    Davies, Tim

    This dissertation consists of three essays in applied microeconomics. Each essay explores a different issue of economic interest. The essay in Chapter 2 describes an experiment designed to investigate if using assets with an intrinsic value that increases over time leads to persistent undervaluation in laboratory asset trading markets. This question has not previously been investigated by researchers. Results from ten sessions are reported. Three used assets with an intrinsic value that decreased over time. The results from these sessions are consistent with the findings by prior researchers who frequently observed price bubbles in laboratory asset trading experiments. The remaining seven sessions used assets with an intrinsic value that increased over time. In all these sessions trading generally occurred at prices below the asset's intrinsic value. In Chapter 3, in an essay co-authored with Adrian Stoian, we study road running races. Tournaments, where ordinal position determines rewards, are an important component of our economy. By studying sporting tournaments, we hope to shed light on the nature of other economically significant tournaments where data may be less readily available. We separately quantify the sorting and incentive effects of tournament prizes by employing a novel two-part model which we apply to a unique data set of road running race results. We present a counterfactual example of how a hypothetical change in prizes would be predicted to change race participation and speed. In Chapter 4, in an essay co-authored with Jedidiah Brewer and Joseph Cullen, we examine the combined effects of the locations and the brands of retail gasoline outlets in Tucson, Arizona on market prices. We apply an innovative approach to model the impact of competing gas stations that avoids limiting analysis to predetermined nearby locations. We show that increased brand diversity is associated with higher prices and that gas stations affiliated with mass

  11. Rayleigh imaging in spectral mammography

    NASA Astrophysics Data System (ADS)

    Berggren, Karl; Danielsson, Mats; Fredenberg, Erik

    2016-03-01

    Spectral imaging is the acquisition of multiple images of an object at different energy spectra. In mammography, dual-energy imaging (spectral imaging with two energy levels) has been investigated for several applications, in particular material decomposition, which allows for quantitative analysis of breast composition and quantitative contrast-enhanced imaging. Material decomposition with dual-energy imaging is based on the assumption that there are two dominant photon interaction effects that determine linear attenuation: the photoelectric effect and Compton scattering. This assumption limits the number of basis materials, i.e. the number of materials that are possible to differentiate between, to two. However, Rayleigh scattering may account for more than 10% of the linear attenuation in the mammography energy range. In this work, we show that a modified version of a scanning multi-slit spectral photon-counting mammography system is able to acquire three images at different spectra and can be used for triple-energy imaging. We further show that triple-energy imaging in combination with the efficient scatter rejection of the system enables measurement of Rayleigh scattering, which adds an additional energy dependency to the linear attenuation and enables material decomposition with three basis materials. Three available basis materials have the potential to improve virtually all applications of spectral imaging.

  12. 4. Photocopy of 1855 engraving from B. J. Lossing, Pictorial ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Photocopy of 1855 engraving from B. J. Lossing, Pictorial Field-Book of the Revolution, volume 2, 1855 SOUTH FRONT FROM WEST - Waynesborough, 2049 Waynesborough Road (Easttown Township), Paoli, Chester County, PA

  13. 4. Photocopy of engraving (From Gleason's Pictorial Drawing Room Companion, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Photocopy of engraving (From Gleason's Pictorial Drawing Room Companion, 1854) Photographer unknown, Date unknown GENERAL EXTERIOR VIEW FROM EAST - Antioch College, Main Hall, Livermore Street & North College Avenue, Yellow Springs, Greene County, OH

  14. 4. Historic American Buildings Survey, From Benjamin J. Lossing, Pictorial ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey, From Benjamin J. Lossing, Pictorial Field Book of the American Revolution, 1855, page 169, EXTERIOR SKETCH, 1855. - Birmingham Friends Meetinghouse, Birmingham & Meetinghouse Roads, Birmingham, Chester County, PA

  15. Part and Whole in Pictorial Relief

    PubMed Central

    Koenderink, Jan; van Doorn, Andrea

    2015-01-01

    What are “natural parts” of pictorial reliefs? Intuitively, and suggested by common lore from the visual arts, they are the bulges that stick out toward the observer. Each such bulge contains a (locally) nearest point and is bounded by one or (usually) more curvilinear ruts. The latter meet in “passes” or saddle points. This divides the relief into “natural districts”. From a formal analysis one knows that reliefs can be divided into “hill districts” or “dale districts”, these two “natural” parcellations being fully distinct. We report empirical results that strongly suggest that visual awareness is based on a partition in bulges, which are mutually only weakly connected. Such a notion immediately explains why inverted reliefs or surfaces illuminated from below appear so different as to be mutually not recognizable. PMID:27551359

  16. Barriers to Mammography among Inadequately Screened Women

    ERIC Educational Resources Information Center

    Stoll, Carolyn R. T.; Roberts, Summer; Cheng, Meng-Ru; Crayton, Eloise V.; Jackson, Sherrill; Politi, Mary C.

    2015-01-01

    Mammography use has increased over the past 20 years, yet more than 30% of women remain inadequately screened. Structural barriers can deter individuals from screening, however, cognitive, emotional, and communication barriers may also prevent mammography use. This study sought to identify the impact of number and type of barriers on mammography…

  17. Essays in applied economics

    NASA Astrophysics Data System (ADS)

    Arano, Kathleen

    Three independent studies in applied economics are presented. The first essay looks at the US natural gas industrial sector and estimates welfare effects associated with the changes in natural gas regulatory policy over the past three decades. Using a disequilibrium model suited to the natural gas industry, welfare transfers and deadweight losses are calculated. Results indicate that deregulation policies, beginning with the NGPA of 1978, have caused the industry to become more responsive to market conditions. Over time, regulated prices converge toward the estimated equilibrium prices. As a result of this convergence, deadweight losses associated with regulation are also diminished. The second essay examines the discounted utility model (DU), the standard model used for intertemporal decision-making. Prior empirical studies challenge the descriptive validity of the model. This essay addresses the four main inconsistencies that have been raised: domain dependence, magnitude effects, time effects, and gain/loss asymmetries. These inconsistencies, however, may be the result of the implicit assumption of linear utility and not a failure of the DU model itself. In order to test this hypothesis, data was collected from in-class surveys of economics classes at Mississippi State University. A random effects model for panel data estimation which accounts for individual specific effects was then used to impute discount rates measured in terms of dollars and utility. All four inconsistencies were found to be present when the dollar measures were used. Using utility measures of the discount rate resolved the inconsistencies in some cases. The third essay brings together two perspectives in the study of religion and economics: modeling religious behavior using economic tools and variables, and modeling economic behavior using religious variables. A system of ordered probit equations is developed to simultaneously model religious activities and economic outcomes. Using data

  18. Essays on strategy VII

    SciTech Connect

    Gill, T.C.

    1990-01-01

    Revolutionary developments in Europe and their global reverberations since 1989 have affected certain aspects of our national strategy. This volume presents nine essays dealing imaginatively with the issues of the post-Cold War period. One of them addresses general US strategy for the 1990s. Three focus on high-level strategic matters: the future of flexible response, antisatellite weapons, and forward, mobile defenses. The others address US chemical weapons policy, use of civilian aircraft for defense airlift, neutrality of the Panama Canal after 1999, arms sales by China, and strategic defense at reduced cost.

  19. Three Essays on Macroeconomics

    NASA Astrophysics Data System (ADS)

    Doda, Lider Baran

    This dissertation consists of three independent essays in macroeconomics. The first essay studies the transition to a low carbon economy using an extension of the neoclassical growth model featuring endogenous energy efficiency, exhaustible energy and explicit climate-economy interaction. I derive the properties of the laissez faire equilibrium and compare them to the optimal allocations of a social planner who internalizes the climate change externality. Three main results emerge. First, the exhaustibility of energy generates strong market based incentives to improve energy efficiency and reduce CO 2 emissions without any government intervention. Second, the market and optimal allocations are substantially different suggesting a role for the government. Third, high and persistent taxes are required to implement the optimal allocations as a competitive equilibrium with taxes. The second essay focuses on coal fired power plants (CFPP) - one of the largest sources of CO2 emissions globally - and their generation efficiency using a macroeconomic model with an embedded CFPP sector. A key feature of the model is the endogenous choice of production technologies which differ in their energy efficiency. After establishing four empirical facts about the CFPP sector, I analyze the long run quantitative effects of energy taxes. Using the calibrated model, I find that sector-specific coal taxes have large effects on generation efficiency by inducing the use of more efficient technologies. Moreover, such taxes achieve large CO2 emissions reductions with relatively small effects on consumption and output. The final essay studies the procyclicality of fiscal policy in developing countries, which is a well-documented empirical observation seemingly at odds with Neoclassical and Keynesian policy prescriptions. I examine this issue by solving the optimal fiscal policy problem of a small open economy government when the interest rates on external debt are endogenous. Given an

  20. Sensitivity of 5- and 7-Month-Old Infants to Pictorial Depth Information.

    ERIC Educational Resources Information Center

    Kaufmann, Ruth; And Others

    1981-01-01

    An Ames static trapezoidal window was used to test infants' responsiveness to pictorial depth. Sensitivity to the pictorial information for depth that is present in the trapezoidal window appears to develop after the age of 22 weeks. (Author/DB)

  1. [Evaluation of radiation doses in mammography].

    PubMed

    Lee, S K; Hwang, S K; Lee, L N; Lou, G C; Wang, C A; Hsu, W J

    1993-03-01

    A dedicated X-ray mammography was introduced to our hospital from 1987 and an imaging receptor of xeroradiography was applied. We reported previously that the average air exposure was 0.79R and that the absorption dose of skin was 1.00 rad. These data are similar to literature reports. Screen-film mammography was introduced recently. To select the best breast imaging and the least radiation exposure, diverse methods were investigated. A dosimetry (Capintec model 192) and a PS-033 parallel ionization chamber were applied to compare the absorption dose on polystyrene phantom between various exposure factors, the application of breast clamp and the size of exposure field. Retrospective estimation of the radiation dose was obtained from the exposure factors of previous mammography since July, 1990 to May, 1992. There were 1035 xeromammographic examinations and 358 examinations with medium-speed screen-film mammography. Another 61 craniocaudal and 96 mediolateral projections with high-speed screen-film mammography were recruited during the recent two months. An ionization chamber (Exradin, Shonka-Wyckoff A5) with an electrometer (Keithley 617) wer selected to obtain the dose equivalent from air exposure between selected exposure factors. The radiation dose of mammography is linearly correlated with voltage/kV and current/mAs. The application of a breast clump reduces 10% of the skin dose. The average exposure factors of xeromammography are 45.6 kV, 163.5 mAs. These results remain the same as in our previous report. Xeromammography has a greater exposure to air, estimated average glandular dose and absorbed dose than screen-film mammography. The mean exposure factor of rapid screen-film mammography gains half the value of medium screen-film mammography, ie. 26.6 kV, 87.0 mAs vs. 26.0 kV, 164.5 mAs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8490794

  2. Do Appalachian Women Attending a Mobile Mammography Program Differ from Those Visiting a Stationary Mammography Facility?

    PubMed Central

    Madhavan, Suresh; Kelly, Kimberly; Metzger, Aaron; Schreiman, Judith; Remick, Scot

    2016-01-01

    To compare the characteristics (demographic, access to care, health-related behavioral, self and family medical history, psychosocial) of women aged 40 years and above who utilize a mobile mammography unit with those women aged 40 years and above who obtain mammography screening at a stationary facility. A cross-sectional study design was used with participant cohorts comprised of women age 40 years and above throughout West Virginia (WV) who utilized mobile mammography unit to get mammogram and those who had mammography screening at the stationary facility and completed the Mammography Screening and Preventive Care Survey. A total of 1,161 women who utilized the mobile mammography unit and 1,104 women who utilized stationary facility were included in the analysis. In logistic regression after adjusting for all the variables, women who utilized mobile mammography unit were more likely to be in age group 40–49, with lower income, with no health insurance coverage, not visit doctor or obstetrician/gynecologist (OB/GYN) in the past year, not adherent to clinical breast exam and mammography screening guidelines, with lower perceived five-year risk of developing breast cancer and with high knowledge about mammography screening. Women who utilize mobile unit are not adherent to mammography screening guidelines thereby suggesting that the mobile mammography unit is indeed reaching a rural vulnerable population who may not routinely access preventive health services. Financial and insurance constraints, as well as access to medical care, restricted WV women from receiving mammography screening from the stationary screening facilities. PMID:23504266

  3. Pictorial communication in virtual and real environments

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R. (Editor)

    1991-01-01

    Papers about the communication between human users and machines in real and synthetic environments are presented. Individual topics addressed include: pictorial communication, distortions in memory for visual displays, cartography and map displays, efficiency of graphical perception, volumetric visualization of 3D data, spatial displays to increase pilot situational awareness, teleoperation of land vehicles, computer graphics system for visualizing spacecraft in orbit, visual display aid for orbital maneuvering, multiaxis control in telemanipulation and vehicle guidance, visual enhancements in pick-and-place tasks, target axis effects under transformed visual-motor mappings, adapting to variable prismatic displacement. Also discussed are: spatial vision within egocentric and exocentric frames of reference, sensory conflict in motion sickness, interactions of form and orientation, perception of geometrical structure from congruence, prediction of three-dimensionality across continuous surfaces, effects of viewpoint in the virtual space of pictures, visual slant underestimation, spatial constraints of stereopsis in video displays, stereoscopic stance perception, paradoxical monocular stereopsis and perspective vergence. (No individual items are abstracted in this volume)

  4. Imaging in childhood scoliosis: a pictorial review.

    PubMed

    Musson, Rachel E; Warren, Daniel J; Bickle, Ian; Connolly, Daniel J; Griffiths, Paul D

    2010-07-01

    Childhood scoliosis is a common clinical entity with a number of different causes. In the majority of cases, the scoliosis is idiopathic, but it may be the manifestation of an occult spinal pathology. The clinical history and examination may elicit certain worrying features such as pain, neurological symptoms or an atypical curve pattern. These findings should prompt advanced imaging, as early and accurate detection of an underlying cause allows optimal planning and timing of surgery and helps reduce associated risks. The most common occult pathologies detected by advanced imaging are Arnold Chiari malformations, syringohydromyelia and closed spinal dysraphism such as diastematomyelia. Advanced imaging techniques, in particular multiplanar MRI, are also increasingly requested in children with known congenital scoliosis associated with spinal dysraphism and developmental causes of scoliosis such as neurofibromatosis and Klippel-Feil syndrome, as it allows superior delineation of the spinal column without the radiation risk. This review aims to examine the different imaging techniques currently used in the evaluation of scoliosis and provide a pictorial summary of the more common causes and associations. PMID:20634252

  5. Digital Mammography and Digital Breast Tomosynthesis.

    PubMed

    Moseley, Tanya W

    2016-06-01

    Breast imaging technology has advanced significantly from the 1930s until the present. American women have a 1 in 8 chance of developing breast cancer. Mammography has been proven in multiple clinical trials to reduce breast cancer mortality. Although a mainstay of breast imaging and improved from film-screen mammography, digital mammography is not a perfect examination. Overlapping obscuring breast tissue limits mammographic interpretation. Breast digital tomosynthesis reduces and/or eliminates overlapping obscuring breast tissue. Although there are some disadvantages with digital breast tomosynthesis, this relatively lost-cost technology may be used effectively in the screening and diagnostic settings. PMID:27101241

  6. The Effectiveness of Textbook, Student Generated, and Pictorial Versions of Presenting Mathematical Problems.

    ERIC Educational Resources Information Center

    Kulm, Gerald; And Others

    The study sought to determine the relationship between problem solving ability and problem presentation stimuli of textbook (T), student generated (S), pictorial (P), textbook and pictorial (TP), and student generated and pictorial (SP). Ten problems for each stimulus were presented to ninth grade algebra students randomly assigned within IQ…

  7. Teaching Science Through Pictorial Models During Read-Alouds

    NASA Astrophysics Data System (ADS)

    Oliveira, Alandeom W.; Rivera, Seema; Glass, Rory; Mastroianni, Michael; Wizner, Francine; Amodeo, Vincent

    2013-03-01

    This study examines how three elementary teachers refer to pictorial models (photographs, drawings, and cartoons) during science read-alouds. While one teacher used realistic photographs for the purpose of visually verifying facts about crystals, another employed analytical diagrams as heuristic tools to help students visualize complex target systems (rainbow formation and human eye functioning). Another teacher used fictional cartoons to engage students in analogical storytelling, communicating animal camouflage as analogous to human "blending in." However, teachers did not always explicitly convey the representational nature of pictorial models (analog and target as separate entities). It is argued that teachers need to become more aware of how they refer to pictorial models in children's science books and how to promote student visual literacy.

  8. Essays in applied microeconomics

    NASA Astrophysics Data System (ADS)

    Davis, Lucas William

    2005-11-01

    The first essay measures the impact of an outbreak of pediatric leukemia on local housing values. A model of residential location choice is used to describe conditions under which the gradient of the hedonic price function with respect to health risk is equal to household marginal willingness to pay to avoid pediatric leukemia risk. This equalizing differential is estimated using property-level sales records from a county in Nevada where residents have recently experienced a severe increase in pediatric leukemia. Housing values are compared before and after the increase with a nearby county acting as a control group. The results indicate that housing values decreased 15.6% during the period of maximum risk. Results are similar for alternative measures of risk and across houses of different sizes. With risk estimates derived using a Bayesian learning model the results imply a statistical value of pediatric leukemia of $5.6 million. The results from the paper provide some of the first market-based estimates of the value of health for children. The second essay evaluates the cost-effectiveness of public incentives that encourage households to purchase high-efficiency durable goods. The demand for durable goods and the demand for energy and other inputs are modeled jointly as the solution to a household production problem. The empirical analysis focuses on the case of clothes washers. The production technology and utilization decision are estimated using household-level data from field trials in which participants received front-loading clothes washers free of charge. The estimation strategy exploits this quasi-random replacement of washers to derive robust estimates of the utilization decision. The results indicate a price elasticity, -.06, that is statistically different from zero across specifications. The parameters from the utilization decision are used to estimate the purchase decision using data from the Consumer Expenditure Survey, 1994-2002. Households

  9. β Pictoris, a young planetary system? A review

    NASA Astrophysics Data System (ADS)

    Vidal-Madjar, A.; Lecavelier des Etangs, A.; Ferlet, R.

    1998-02-01

    β Pictoris is a bright southern hemisphere star observed in 1983 by the IRAS satellite as presenting a large and unexpected IR excess. This excess was called the Vega-like phenomenon and quickly identified as due to circumstellar dust. Subsequently in 1984, using stellar coronography, dust was also directly seen as an edge-on disk extended to several hundreds of AUs. Since then, β Pictoris has been continuously observed. We present here a review of our present understanding of the β Pictoris circumstellar environment which still appears unique in the solar neighborhood. The circumstellar dust disk is predominantly made of relatively large particles (one micron or more) extending outward to more than 1000 AU and presenting a clearer (dust free) central region away to about 35 AU from the star. The gas is detected through stable and variable spectroscopic signatures revealing a permanent gas disk with sporadic inflows and also a few outflows. These are partially interpreted in terms of evaporation of kilometer-sized bodies very close to the star. Evaporation or destruction through collisions of kilometer-sized bodies seems to be needed also to explain both the dust as well as the very presence of the CO molecule detected in the circumstellar gas. Several indirect arguments along with the observation of a very peculiar photometric variation of the star suggests that even giant planets may have already formed in the β Pictoris system. β Pictoris is thus possibly the missing link between young stellar objects presenting proto-planetary circumstellar disks and much more evolved systems in which planets (at least giant ones) are already formed. β Pictoris is probably a unique place where we may now observe planetary formation as well as other phenomena that have taken place in the first 10 8 years of a young stellar system.

  10. Assessing elements of women's decisions about mammography.

    PubMed

    Rakowski, W; Dube, C E; Marcus, B H; Prochaska, J O; Velicer, W F; Abrams, D B

    1992-01-01

    We investigated motivational and cognitive processes of behavior change with respect to mammography screening. One hundred forty-two women (ages 40 and older) recruited from three worksites answered a 41-item questionnaire consisting of statements based on constructs from the transtheoretical model of behavior change. Principal-components analysis identified two factors: a six-item component representing positive perceptions of mammography (Pros) and a six-item component representing avoidance of mammography (Cons). Analysis of variance showed that Pros, Cons, and a derived Decisional Balance measure (Pros minus Cons) were associated with stage of mammography adoption. Results are consistent with applications of the model to smoking cessation. The model is also discussed as it relates to other theories of behavior change and as a general strategy for analyzing perceptual data pertinent to health-related actions and intentions for behavioral change. PMID:1582379

  11. Teaching Students with Severe Intellectual Disabilities Non-Representational Art Using a New Pictorial and Musical Programme.

    ERIC Educational Resources Information Center

    Riddoch, Jane V.; Waugh, Russell F.

    2003-01-01

    A recently developed pictorial and musical program was used to teach abstract art to 12 elementary students with severe intellectual disabilities and 12 controls. There was a significant main instructional effect favoring pictorial with classical music over both pictorial only and pictorial with rock music. (Contains references.) (Author/CR)

  12. Infrared Observations of beta Pictoris Analogs

    NASA Astrophysics Data System (ADS)

    Fajardo-Acosta, S. B.; Knacke, R. F.; Telesco, C. M.

    1993-12-01

    We searched for 10 microns silicate emission from circumstellar dust in 13 main-sequence stars that possibly exemplify the beta Pictoris phenomenon. We have previously detected the silicate feature in 51 Oph (Fajardo-Acosta, Telesco, & Knacke 1993, ApJ, in press) through mid-IR narrowband spectrophotometry (FWHM ~ 1 microns) with the MSFC Big Mac camera and the 2--30 microns Facility bolometer at the IRTF. We are using the same instrumentation in our survey of other Vega-type disks. These observations were motivated by the detection of the silicate feature in beta Pic (Telesco & Knacke 1991, ApJ, 372, L29). We followed the detections in beta Pic and 51 Oph with 2.9--13.5 microns intermediate-resolution (lambda /Delta lambda ~ 50) spectroscopy with the Aerospace Corp. Infrared Spectrograph. The higher resolution data confirmed the analogy of the silicate features in beta Pic (Knacke et al. 1993, ApJ, in press) and 51 Oph (Russell et al. 1993, in prep.) to similar features in Solar System cometary spectra. Among the Vega-type stars we recently observed, beta UMa, zeta Lep, sigma Her, and gamma Oph exhibit significant dust emission at 10 microns (>= 0.15 Jy). We expect to resolve whether silicate emission is present with the higher spectral resolution available with the Aerospace Spectrograph. We have compared the spectrum of beta Pic with those in the data compilation of the IRAS Low Resolution Spectrograph. Of the 5425 sources, 88 exhibit 10 microns silicate emission features that match beta Pic's reasonably well. Many of these sources do not have known associations; those that do are typically low-mass giant branch Miras or massive supergiants. We are investigating at least 5 possible associations with early-type main-sequence stars. This research was sponsored by the NASA Origins of Solar Systems Research Program under grant NAGW-2334.

  13. [Malthus's Essay and Newton's Principia].

    PubMed

    Nakanishi, Y

    1989-05-01

    The author examines a natural scientific approach to demography using the example of Malthus's "Essay on the Principle of Population." The work is analyzed and compared to Newton's "Philosophiae Naturalis Principia Mathematica." PMID:12342767

  14. Preventing the pack size effect: exploring the effectiveness of pictorial and non-pictorial serving size recommendations.

    PubMed

    Versluis, Iris; Papies, Esther K; Marchiori, David

    2015-04-01

    People eat more from large than from small packs, which is known as the pack size effect. We hypothesized that providing a serving size recommendation would reduce the influence of the pack size on consumption and would thus diminish the pack size effect. Moreover, we hypothesized that a pictorial serving size recommendation, displaying food amounts visually, would be more effective than a non-pictorial recommendation that communicates the recommended amount in grams only. We tested these hypotheses in two online experiments (N = 317 and N = 324) and in one lab experiment (N = 89). In the online experiments, participants were shown a small or a large pack of unhealthy snacks, with or without a serving size recommendation. The main outcome measure was expected consumption. Replicating the pack size effect in an online setting, we found that participants expected to consume more food from large than from small packs. Furthermore, the pack size effect was considerably stronger for men than for women. Importantly, when including portion size preferences as a covariate, the pictorial serving size recommendation significantly reduced expected consumption, especially when placed on a large pack, as hypothesized. The non-pictorial serving size recommendation had no effect. In the lab experiment, students received a large bag of M&M's which did or did not contain the pictorial serving size recommendation. We again included general portion size preferences as a covariate. The serving size recommendation significantly lowered the amount of M&M's that participants served themselves, but only when participants reported to have noticed the serving size recommendation. We conclude that providing a pictorial serving size recommendation can be an effective intervention strategy to reduce the pack size effect, if it attracts sufficient attention. PMID:25528692

  15. Three essays on contingent valuation

    NASA Astrophysics Data System (ADS)

    Beatty, Timothy Kenneth Munro

    2001-07-01

    This dissertation consists of three essays on the contingent valuation methodology. The first essay develops a theoretical model of how agents respond to willingness to pay questions in a survey context. In particular, this essay focuses on the difference between a voluntary contribution mechanism and a mandatory contribution mechanism. The second essay applies this theory to a survey of willingness to pay for renewable energy by varying the mechanism by which the public good is supplied. The third essay proposes a methodology for choosing the number, location and range of contributions or bid levels in dichotomous choice contingent valuation surveys. The first essay, "Mandatory vs. Voluntary Payment to a Public Good" models the differing incentive effects of two different payment mechanisms in contingent valuations surveys. It is shown that under rationed voluntary payment (where each agent can contribute either a fixed amount or nothing) there exists a Nash equilibrium in which the level of public good provided is strictly below the level provided under a mandatory provision rule. This result is generalized to hypothetical valuation surveys and a set of condition ranking willingness to pay under each mechanism is described. The second essay "Valuing a Public Good" describes the result of a survey designed to test the above theory. This essay considers willingness to pay for renewable energy. In order to test the theory, a split sample survey of over fifteen hundred respondents was conducted. One half of the sample was asked whether they would volunteer to pay for green power and the other half was asked whether they would vote to support a program in which the entire population was required to contribute towards the provision of the public good. On average, respondents' willingness to pay was higher for the public good provided by the mandatory provision mechanism. The third essay describes the literature on how the contribution or bid levels can be chosen to

  16. Family/Friend Recommendations and Mammography Intentions: The Roles of Perceived Mammography Norms and Support

    ERIC Educational Resources Information Center

    Molina, Yamile; Ornelas, India J.; Doty, Sarah L.; Bishop, Sonia; Beresford, Shirley A. A.; Coronado, Gloria D.

    2015-01-01

    Identifying factors that increase mammography use among Latinas is an important public health priority. Latinas are more likely to report mammography intentions and use, if a family member or friend recommends that they get a mammogram. Little is known about the mechanisms underlying the relationship between social interactions and mammography…

  17. Mammography

    SciTech Connect

    Letreut, A.; Dilhuydy, M.H.

    1990-01-01

    This book interprets screen/film mammograms, covering a wide range of clinical situations. It is divided into four sections: radiologic technology, diagnosis, use of mammograms in special conditions, and general considerations.

  18. Using Voice and Audience in Essay Examinations.

    ERIC Educational Resources Information Center

    Donlan, Dan

    Students dislike writing essay examinations as much as teachers dislike reading them. Perhaps no alternatives to the essay exam exist, but certainly the task can be lessened by altering the format of the essay exam. In an education class at a California university, students select in advance one essay question from a list of several, and field…

  19. The Encoding of Pictorial Information in Children and Adults.

    ERIC Educational Resources Information Center

    Ward, William C.; Naus, Mary J.

    Age and instructional differences in the representation of pictorial information were investigated in a recognition memory task. A total of 56 nursery school and 40 college-age subjects observed pictures under name labeling, color labeling, imaging, and no label instructions. Subjects were then tested for retention of object identity and color…

  20. How Pictorial Knowledge Representations Mediate Collaborative Knowledge Construction in Groups

    ERIC Educational Resources Information Center

    Naykki, Piia; Jarvela, Sanna

    2008-01-01

    This study investigates the process of collaborative knowledge construction when technology and pictorial knowledge representations are used for visualizing individual and groups' shared ideas. The focus of the study is on how teacher-students contribute to the group's collaborative knowledge construction and use each other's ideas and tools as an…

  1. Imaging of Adult Ocular and Orbital Pathology - a Pictorial Review

    PubMed Central

    Grech, Reuben; Cornish, Kurt Spiteri; Galvin, Patrick Leo; Grech, Stephan; Looby, Seamus; O’Hare, Alan; Mizzi, Adrian; Thornton, John; Brennan, Paul

    2014-01-01

    Orbital pathology often presents a diagnostic challenge to the reporting radiologist. The aetiology is protean, and clinical input is therefore often necessary to narrow the differential diagnosis. With this manuscript, we provide a pictorial review of adult ocular and orbital pathology. PMID:24967016

  2. Pictorial Analogies XI: Concentrations and Acidity of Solutions.

    ERIC Educational Resources Information Center

    Fortman, John J.

    1994-01-01

    Presents pictorial analogies of several concepts relating to solutions for chemistry students. These include concentration of solution, strength of solution, supersaturated solution, and conjugate acid-base pairs. Among the examples are comparison of acid strength to percentage of strong soldiers or making supersaturated solution analogous to a…

  3. The Interaction of Color Realism and Pictorial Recall Memory.

    ERIC Educational Resources Information Center

    Berry, Louis H.

    This study investigated the interaction of variations in color realism on pictorial recall memory in order to better understand the effects of variations in color realism, and to draw comparisons between visual recall memory and visual recognition memory in terms of color information processing. Stimulus materials used were three sets of slides,…

  4. Teaching Science through Pictorial Models during Read-Alouds

    ERIC Educational Resources Information Center

    Oliveira, Alandeom W.; Rivera, Seema; Glass, Rory; Mastroianni, Michael; Wizner, Francine; Amodeo, Vincent

    2013-01-01

    This study examines how three elementary teachers refer to pictorial models (photographs, drawings, and cartoons) during science read-alouds. While one teacher used realistic photographs for the purpose of visually verifying facts about crystals, another employed analytical diagrams as heuristic tools to help students visualize complex target…

  5. Mammography calibration qualities establishment in a Mo- Mo clinical system

    NASA Astrophysics Data System (ADS)

    Corrêa, E. L.; dos Santos, L. R.; Vivolo, V.; Potiens, M. P. A.

    2016-07-01

    In this study the mammography calibration qualities were established in a clinical mammography system. The objective is to provide the IPEN instruments calibration laboratory with both mammography calibration methods (using a clinical and an industrial system). The results showed a good behavior of mammography equipment, in terms of kVp, PPV and exposure time. The additional filtration of molybdenum is adequate, air-kerma rates were determined and spectra were obtained.

  6. Essays in public economics

    NASA Astrophysics Data System (ADS)

    Seligman, Jason Scott

    2002-01-01

    Three essays in the field of public economics are included in this thesis. Chapter 1 begins this work with an introduction to public economics and places the remaining chapters in context. Like all economic agents, the government must manage its cash position. Chapter 2 considers this activity. Short-term financial requirements cause the government to solicit the market for bills not previously scheduled (Cash Management Bills). Using data from the US Treasury's Proprietary Domestic Finance Database, this chapter shows that these bills have higher costs than normal bills, suggesting that both Treasury and financial markets appreciate that demand is more inelastic for these instruments. In addition, this research identifies several factors that increase finance costs for Treasury in meeting short-term financial need. Chapter 3 explores location choices for generation investment in a re-regulated electricity market. Recently, there have been significant changes in the regulation of electricity in the State of California. These changes may affect generation investment behavior within the State, an important consideration for policy makers. This work identifies the impact of public sector regulatory change on private sector investment outcomes, by comparing the location and scope of electricity generation projects before and after two specific regulatory changes in air quality management and transmission tariff charges, while controlling for expected population growth patterns within the State. Significant changes in location preference are identified using factors for the northern and southern transmission zones, NP15 and SP15, the intermediate zone ZP26, and for areas outside of ISO control. Chapter 4 considers Disability Insurance and individual public pension investment accounts. Current debate on the Social Security Administration's long-term finance of benefits includes proposals for independent private investment via individual accounts. The author investigates

  7. Implicit Motivational Impact of Pictorial Health Warning on Cigarette Packs

    PubMed Central

    Volchan, Eliane; David, Isabel A.; Tavares, Gisella; Nascimento, Billy M.; Oliveira, Jose M.; Gleiser, Sonia; Szklo, Andre; Perez, Cristina; Cavalcante, Tania; Pereira, Mirtes G.; Oliveira, Leticia

    2013-01-01

    Objective The use of pictorial warning labels on cigarette packages is one of the provisions included in the first ever global health treaty by the World Health Organization against the tobacco epidemic. There is substantial evidence demonstrating the effectiveness of graphic health warning labels on intention to quit, thoughts about health risks and engaging in cessation behaviors. However, studies that address the implicit emotional drives evoked by such warnings are still underexplored. Here, we provide experimental data for the use of pictorial health warnings as a reliable strategy for tobacco control. Methods Experiment 1 pre-tested nineteen prototypes of pictorial warnings to screen for their emotional impact. Participants (n = 338) were young adults balanced in gender, smoking status and education. Experiment 2 (n = 63) tested pictorial warnings (ten) that were stamped on packs. We employed an innovative set-up to investigate the impact of the warnings on the ordinary attitude of packs’ manipulation, and quantified judgments of warnings’ emotional strength and efficacy against smoking. Findings Experiment 1 revealed that women judged the warning prototypes as more aversive than men, and smokers judged them more aversive than non-smokers. Participants with lower education judged the prototypes more aversive than participants with higher education. Experiment 2 showed that stamped warnings antagonized the appeal of the brands by imposing a cost to manipulate the cigarette packs, especially for smokers. Additionally, participants’ judgments revealed that the more aversive a warning, the more it is perceived as effective against smoking. Conclusions Health warning labels are one of the key components of the integrated approach to control the global tobacco epidemic. The evidence presented in this study adds to the understanding of how implicit responses to pictorial warnings may contribute to behavioral change. PMID:23977223

  8. Breast dosimetry in clinical mammography

    NASA Astrophysics Data System (ADS)

    Benevides, Luis Alberto Do Rego

    The objective of this study was show that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. In the study, AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The protocol proposes the use of a fiber-optic coupled (FOCD) or Metal Oxide Semiconductor Field Effect Transistor (MOSFET) dosimeter to measure the entrance skin exposure at the time of the mammogram without interfering with diagnostic information of the mammogram. The study showed that FOCD had sensitivity with less than 7% energy dependence, linear in all tube current-time product stations, and was reproducible within 2%. FOCD was superior to MOSFET dosimeter in sensitivity, reusability, and reproducibility. The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. In addition, the study population anthropometric

  9. US of breast masses categorized as BI-RADS 3, 4, and 5: pictorial review of factors influencing clinical management.

    PubMed

    Raza, Sughra; Goldkamp, Allison L; Chikarmane, Sona A; Birdwell, Robyn L

    2010-09-01

    The Breast Imaging Reporting and Data System (BI-RADS) lexicon for ultrasonography (US) is based on the established lexicon used successfully in mammography and attempts to provide a common language to avoid ambiguity in interpreting, reporting, and teaching breast US. Proper and consistent use of the BI-RADS US lexicon has numerous advantages, including facilitating (a) communication of final assessment categories that clearly indicate management recommendations, (b) data tracking for self-audits, and (c) clinical review of outcome summaries. However, the literature to date does not include sufficient data on outcomes to validate clinical use of the BI-RADS US lexicon. In this article, a pictorial review of the BI-RADS US lexicon descriptors is provided, and specific cases from a retrospective review are used to highlight the challenges in using the BI-RADS US lexicon. With these examples, suggestions are offered for greater clarity in the use of this lexicon. The technical challenges in follow-up US imaging are described. The challenges in assigning final assessment categories are detailed, as well as the clinical factors that may influence decision making and the management of certain lesions. PMID:20833845

  10. Elasto-Mammography: Elastic Property Reconstruction in Breast Tissues

    SciTech Connect

    Wang, Z. G.; Liu, Y.; Wang, G.; Sun, L. Z.

    2008-02-15

    Mammography is the primary method for screening and detecting breast cancers. However, it frequently fails to detect small tumors and is not quite specific in terms of tumor benignity and malignancy. The objective of this paper is to develop a new imaging modality called elasto-mammography that generates the modulus elastograms based on conventional mammographs. A new elastic reconstruction method is described based on elastography and mammography for breast tissues. Elastic distribution can be reconstructed through the measurement of displacement provided by mammographic projection. It is shown that the proposed elasto-mammography provides higher sensitivity and specificity than the conventional mammography on its own for breast cancer diagnosis.

  11. An Encyclopedic Undertaking. Essay Review.

    ERIC Educational Resources Information Center

    Altbach, Philip G.

    1985-01-01

    Reviews the 10-volume "International Encyclopedia of Education: Research and Studies," edited by Torsten Husen and T. Neville Postlethwaite. Discusses useful features, organizational framework, clusters of educational themes, bias toward English-language sources, articles on specific national educational systems, theme essays concerning…

  12. Essays in Education and Macroeconomics

    ERIC Educational Resources Information Center

    Herrington, Christopher M.

    2013-01-01

    This dissertation consists of three essays on education and macroeconomics. The first chapter analyzes whether public education financing systems can account for large differences among developed countries in earnings inequality and intergenerational earnings persistence. I first document facts about public education in the U.S. and Norway, which…

  13. Halley's Comet: A Bibliographic Essay.

    ERIC Educational Resources Information Center

    Gallant, Stephen L.

    1985-01-01

    This bibliographic essay evaluates six books on Halley's Comet as science writings that fall into three categories: middle school and junior high-level books; senior high to adult-level books; and advanced level. Author, number of pages, publication date, price, International Standard Book Number, and publisher information are provided. (EJS)

  14. Three Essays on College Quality

    ERIC Educational Resources Information Center

    Seki, Mai

    2012-01-01

    This dissertation consists of three essays on adolescents' post secondary education choices and labor market returns. The first chapter analyzes returns to selectivity of four-year colleges by different post-bachelor's degree schooling paths. The second chapter documents the role of family income in college application and enrollment…

  15. Two Essays in Economic Education

    ERIC Educational Resources Information Center

    Evans, Brent A.

    2013-01-01

    Prior researchers (Anderson et al. 1994; Ballard & Johnson 2004; Hoag & Benedict 2010) have shown that different math abilities do not equally correlate with success in economics, yet no research has specifically compared algebra and geometry skills as predictors of economics success. In the first essay, I find that students' standardized…

  16. Sequential Effects in Essay Ratings

    ERIC Educational Resources Information Center

    Attali, Yigal

    2011-01-01

    Contrary to previous research on sequential ratings of student performance, this study found that professional essay raters of a large-scale standardized testing program produced ratings that were drawn toward previous ratings, creating an assimilation effect. Longer intervals between the two adjacent ratings and higher degree of agreement with…

  17. Two Essays on Shared Governance.

    ERIC Educational Resources Information Center

    Doud, Robert E.

    These two essays present philosophical ideas on the development of shared governance in academic institutions. What philosophy has to contribute to governance is the very level of generality on which it "thinks." Philosophy places value on general principles and long-term goals, rather than particular cases and practical solutions. Philosophy also…

  18. Women's Studies: A Bibliographic Essay.

    ERIC Educational Resources Information Center

    Kirtland, Monika

    The essay section provides a definition and short history of women's studies and explores the implications in regard to the administration and teaching of such courses. The bibliography lists and annotates material useful for all levels of education. Information sources covered include government agencies and societies, reference sources (such as…

  19. Emotions in context: pictorial influences on affective attributions.

    PubMed

    Marian, Diane E; Shimamura, Arthur P

    2012-04-01

    The visual illusion Terror Subterra, by Roger Shepard (1990), depicts a seemingly large creature chasing another in a tunnel, yet both creatures are physically identical. In addition to this visual illusion, the two creatures also appear to exhibit different emotions, as the background creature (the pursuer) appears angry whereas the foreground creature (the pursued) appears fearful. We explored this context effect by first establishing the magnitude of the emotional bias effect. We then modified the original drawing in various ways, such as equating for perceived size, removing one creature from the scene, and removing the pictorial context altogether. Findings suggest that the emotional bias is due to the pictorial setting and to the perceived social-emotional relationship between the two creatures. These results highlight the importance of both perceptual and social-emotional influences in driving affective attributions. PMID:22201243

  20. Improving the timeliness of written patient notification of mammography results by mammography centers.

    PubMed

    Boudreau, Robert M; McNally, Colleen; Rensing, Edna M; Campbell, Miriam K

    2004-01-01

    Timely reporting of mammogram results helps to reduce anxiety for women with negative results and speeds up diagnosis or treatment in the case of abnormal results. The goal of this project was to improve the rate at which Virginia mammography centers provide a written report to women in lay terms within 30 days of a mammogram. The project included six intervention and five control mammography centers. The baseline period was prior to when new regulations in the Mammography Quality Standards Act (MQSA) took effect in April 1999. The re-measurement period was after April 1999. Data were obtained from abstraction of mammography reports and patient notification letters from a sample of patients with negative and abnormal mammography results at each mammography center. Each intervention mammography center received a notebook that included numerous tools on systems for patient notification and tracking, baseline notification rates and other abstracted information, biopsy recommendations, sample results letters, and a copy of the MQSA. For negative mammograms, the intervention group in aggregate increased from 24% at baseline to 79% at re-measurement in their rate of notification within 30 days. The control group increased from 25% to 46%. For abnormal mammograms, increases were from 35% to 85% and from 25% to 58%, respectively. The intervention group's increases were considerably higher, suggesting an effect due to the interventions that involved technical assistance, education, and system change. All increases were statistically significant (p < 0.01). At baseline, three intervention centers and two controls had policies for written notification. All 11 had policies at re-measurement. However, only two of the five control centers could provide clear supporting documentation for dates of notification at re-measurement. Mammography centers can benefit from guidance in the form of intervention materials specifically designed to address the MQSA sections that apply to

  1. Does Gender Discrimination Impact Regular Mammography Screening? Findings from the Race Differences in Screening Mammography Study

    PubMed Central

    DAILEY, AMY B.; KASL, STANISLAV V.; JONES, BETH A.

    2011-01-01

    Objective To determine if gender discrimination, conceptualized as a negative life stressor, is a deterrent to adherence to mammography screening guidelines. Methods African American and white women (1451) aged 40–79 years who obtained an index screening mammogram at one of five urban hospitals in Connecticut between October 1996 and January 1998 were enrolled in this study. This logistic regression analysis includes the 1229 women who completed telephone interviews at baseline and follow-up (average 29.4 months later) and for whom the study outcome, nonadherence to age-specific mammography screening guidelines, was determined. Gender discrimination was measured as lifetime experience in seven possible situations. Results Gender discrimination, reported by nearly 38% of the study population, was significantly associated with nonadherence to mammography guidelines in women with annual family incomes of ≥$50,000 (OR 1.99, 95% CI 1.33, 2.98) and did not differ across racial/ethnic group. Conclusions Our findings suggest that gender discrimination can adversely influence regular mammography screening in some women. With nearly half of women nonadherent to screening mammography guidelines in this study and with decreasing mammography rates nationwide, it is important to address the complexity of nonadherence across subgroups of women. Life stressors, such as experiences of gender discrimination, may have considerable consequences, potentially influencing health prevention prioritization in women. PMID:18321171

  2. Two families of exocomets in the β Pictoris system.

    PubMed

    Kiefer, F; des Etangs, A Lecavelier; Boissier, J; Vidal-Madjar, A; Beust, H; Lagrange, A-M; Hébrard, G; Ferlet, R

    2014-10-23

    The young planetary system surrounding the star β Pictoris harbours active minor bodies. These asteroids and comets produce a large amount of dust and gas through collisions and evaporation, as happened early in the history of our Solar System. Spectroscopic observations of β Pictoris reveal a high rate of transits of small evaporating bodies, that is, exocomets. Here we report an analysis of more than 1,000 archival spectra gathered between 2003 and 2011, which provides a sample of about 6,000 variable absorption signatures arising from exocomets transiting the disk of the parent star. Statistical analysis of the observed properties of these exocomets allows us to identify two populations with different physical properties. One family consists of exocomets producing shallow absorption lines, which can be attributed to old exhausted (that is, strongly depleted in volatiles) comets trapped in a mean motion resonance with a massive planet. Another family consists of exocomets producing deep absorption lines, which may be related to the recent fragmentation of one or a few parent bodies. Our results show that the evaporating bodies observed for decades in the β Pictoris system are analogous to the comets in our own Solar System. PMID:25341784

  3. Pictorial approaches for measuring time use in rural Ethiopia

    PubMed Central

    Masuda, Yuta J.; Fortmann, Lea; Gugerty, Mary Kay; Smith-Nilson, Marla; Cook, Joseph

    2014-01-01

    Time use researchers working in least developed countries (LDCs) face difficulties collecting data from illiterate populations who may conceptualize time differently than those in industrialized countries. We identify existing gaps in time use data collection methods and discuss two novel, pictorial methods to collect time use data from these populations. The first method is a modified recall interview modeled on participatory rural appraisal (PRA) methods that asks respondents to place macaroni on pictures of activity categories in proportion to the amount of time spent on that activity during the previous day. The second is a simplified pictorial time diary that uses a timer and sequentially-numbered stickers to re-create the temporal order of activities in 30-minute increments. The latter method also avoids recall bias problems. We present time use data collected in 2009 using these methods in a study examining the impacts of water infrastructure on women and children’s time use in rural Ethiopia. In total, we collected information using the first method from 263 household members over age 10, including 167 water collectors, and pilot-tested the pictorial diary approach with 10 adult respondents. PMID:25620832

  4. Enriching Automated Essay Scoring Using Discourse Marking.

    ERIC Educational Resources Information Center

    Burstein, Jill; Kukich, Karen; Wolff, Susanne; Lu, Chi; Chodorow, Martin

    Electronic Essay Rater (e-rater) is a prototype automated essay scoring system built at Educational Testing Service that uses discourse marking in addition to syntactic information and topical content vector analyses to assign essay scores automatically. This paper gives a general description of e-rater as a whole, but its emphasis is on the…

  5. A Reflective Essaying Model for Higher Education

    ERIC Educational Resources Information Center

    Badley, Graham

    2009-01-01

    Purpose: The purpose of this paper is to outline a reflective essaying model as a useful way of encouraging learning in higher education. It aims to define reflective essaying as the free and serious play of mind on an interesting topic in an attempt to learn. Design/methodology/approach: Reflective essaying is first introduced as a unifying…

  6. Going Further: Essays in Further Education.

    ERIC Educational Resources Information Center

    Flint, Colin, Ed.; Austin, Michael, Ed.

    This volume contains 16 essays on Further Education (FE) in the context of its changing status and role in the educational and economic life of Great Britain. The essays are grouped around four main themes: (1) FE and mission; (2) managerial responsibilities; (3) context; and (4) diversity. The essays are: "FE Makes Itself Indispensable" (Tony…

  7. In Defense of the Formula Essay

    ERIC Educational Resources Information Center

    Haluska, Jan Charles

    2007-01-01

    In 1970, the author learned a simple step in making essays from his advisor. His advisor used a drawing of the Parthenon to illustrate the creation of a five-paragraph essay. It was obvious that his advisor was hesitant on teaching them a very simple concept of essay writing because it was pretty mechanical. Like his advisor, a lot of teachers…

  8. Restructuring for Urban Student Success: Essay Collection.

    ERIC Educational Resources Information Center

    Jackson, Barbara, Ed.; Levine, Jodi, Ed.; Patton, Judy, Ed.

    This publication presents essays by members of Restructuring for Urban Student Success (RUSS) and other faculty, administrators, staff, and graduate students on participating campuses. The essays describe the work of RUSS and document curricular restructuring and reform efforts occurring at RUSS partner institutions. Part 1 includes essays by RUSS…

  9. The Rise of the Essay Coach

    ERIC Educational Resources Information Center

    Gose, Ben

    2007-01-01

    College admissions essay coaches have been hanging out shingles since the early 1990s. The business has grown sharply over the past decade thanks to the ease of editing via the Internet and students' desire to gain any possible edge as many colleges have become more selective. The companies, with names like Cambridge Essay Service, EssayEdge,…

  10. Essays on Dynamic Competition and Academic Entrepreneurship

    ERIC Educational Resources Information Center

    Pham, Huyen T.

    2012-01-01

    My dissertation focuses on dynamic firm competition and academic entrepreneurship. The first essay studies the dynamics and equilibrium outcomes of a duopoly in which firms make decisions about both capacity expansion and cost reduction. The second essay is an extension of the framework used in the first essay to study the strategic roles of…

  11. The mammography project at the SYRMEP beamline.

    PubMed

    Dreossi, D; Abrami, A; Arfelli, F; Bregant, P; Casarin, K; Chenda, V; Cova, M A; Longo, R; Menk, R-H; Quai, E; Quaia, E; Rigon, L; Rokvic, T; Sanabor, D; Tonutti, M; Tromba, G; Vascotto, A; Zanconati, F; Castelli, E

    2008-12-01

    A clinical program for X-ray phase contrast (PhC) mammography with synchrotron radiation (SR) has been started in March 2006 at the SYRMEP beamline of Elettra, the SR facility in Trieste, Italy. The original beamline layout has been modified substantially and a clinical facility has been realized. In order to fulfill all security requirements, dedicated systems have been designed and implemented, following redundancy criteria and "fail safe" philosophy. Planar radiographic images are obtained by scanning simultaneously the patient and the detector through the stationary and laminar SR beam. In this first phase of the project a commercial screen-film system has been used as image receptor. Upon approval by the respective authorities, the mammography program is about half way to conclusion. Up to now about 50 patients have been examined. The patients are volunteers recruited by the radiologist after conventional examinations at the hospital resulted in an uncertain diagnosis. As an example one case of PhC SR mammography is shown and compared to conventional digital mammography. Preliminary analysis shows the high diagnostic quality of the PhC SR images that were acquired with equal or less delivered dose compared to the conventional ones. PMID:18617344

  12. Beyond the mammography debate: a moderate perspective

    PubMed Central

    Kaniklidis, C

    2015-01-01

    After some decades of contention, one can almost despair and conclude that (paraphrasing) “the mammography debate you will have with you always.” Against that sentiment, in this review I argue, after reflecting on some of the major themes of this long-standing debate, that we must begin to move beyond the narrow borders of claim and counterclaim to seek consensus on what the balance of methodologically sound and critically appraised evidence demonstrates, and also to find overlooked underlying convergences; after acknowledging the reality of some residual and non-trivial harms from mammography, to promote effective strategies for harm mitigation; and to encourage deployment of new screening modalities that will render many of the issues and concerns in the debate obsolete. To these ends, I provide a sketch of what this looking forward and beyond the current debate might look like, leveraging advantages from abbreviated breast magnetic resonance imaging technologies (such as the ultrafast and twist protocols) and from digital breast tomosynthesis—also known as three-dimensional mammography. I also locate the debate within the broader context of mammography in the real world as it plays out not for the disputants, but for the stakeholders themselves: the screening-eligible patients and the physicians in the front lines who are charged with enabling both the acts of screening and the facts of screening at their maximally objective and patient-accessible levels to facilitate informed decisions. PMID:26089721

  13. Physical measures of image quality in mammography

    NASA Astrophysics Data System (ADS)

    Chakraborty, Dev P.

    1996-04-01

    A recently introduced method for quantitative analysis of images of the American College of Radiology (ACR) mammography accreditation phantom has been extended to include signal- to-noise-ratio (SNR) measurements, and has been applied to survey the image quality of 54 mammography machines from 17 hospitals. Participants sent us phantom images to be evaluated for each mammography machine at their hospital. Each phantom was loaned to us for obtaining images of the wax insert plate on a reference machine at our institution. The images were digitized and analyzed to yield indices that quantified the image quality of the machines precisely. We have developed methods for normalizing for the variation of the individual speck sizes between different ACR phantoms, for the variation of the speck sizes within a microcalcification group, and for variations in overall speeds of the mammography systems. In terms of the microcalcification SNR, the variability of the x-ray machines was 40.5% when no allowance was made for phantom or mAs variations. This dropped to 17.1% when phantom variability was accounted for, and to 12.7% when mAs variability was also allowed for. Our work shows the feasibility of practical, low-cost, objective and accurate evaluations, as a useful adjunct to the present ACR method.

  14. Development Of A Digital Mammography System

    NASA Astrophysics Data System (ADS)

    Yaffe, M. J.; Nishikawa, R. M.; Maidment, A. D. A.; Fenster, A.

    1988-06-01

    A digital breast imaging system is under development to provide improved detectability of breast cancer. In previous work, the limitations of screen-film mammography were studied using both theoretical and experimental techniques. Important limitations were found in both the acquisition and the display components of imaging. These have been addressed in the design of a scanned-projection digital mammography system. A high resolution x-ray image intensifier (XRII), optically coupled to a self-scanned linear photodiode array, is used to record the image. Pre- and post-patient collimation virtually eliminates scattered radiation and veiling glare of the XRII with only a 20% increase in dose due to penumbra. Geometric magnification of 1.6 times is employed to achieve limiting spatial resolution of 7 1p/mm. For low-contrast objects as small as 0.1 mm in diameter, the digital system is capable of producing images with higher contrast and signal-to-noise ratio than optimally-exposed conventional film-screen mammography systems. Greater latitude is obtainable on the digital system because of its wide dynamic range and linearity. The slit system is limited due to long image acquisition times, and poor quantum efficiency. This motivated our current work on a slot beam digital mammography system which is based on a fiber-optic x-ray detector. Preliminary results of this system will be presented.

  15. Barriers to mammography among inadequately screened women.

    PubMed

    Stoll, Carolyn R T; Roberts, Summer; Cheng, Meng-Ru; Crayton, Eloise V; Jackson, Sherrill; Politi, Mary C

    2015-02-01

    Mammography use has increased over the past 20 years, yet more than 30% of women remain inadequately screened. Structural barriers can deter individuals from screening, however, cognitive, emotional, and communication barriers may also prevent mammography use. This study sought to identify the impact of number and type of barriers on mammography screening status, and to examine whether number and type of barriers are different for never-screened and off-schedule women. A total of 182 women aged 40 years or older completed a computer kiosk facilitated survey as part of a larger patient navigator intervention. Logistic regression analysis indicated that breast cancer knowledge predicted whether a woman had ever had a mammogram (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.02-1.06, p = .0003), while the number of emotional, structural, and communication barriers predicted whether a woman was on-schedule for mammograms (OR = 0.79, 95% CI = 0.65-0.95, p = .0127). The results suggest that to increase the use of mammography at recommended regular intervals, interventions should be tailored toward current screening status. PMID:24722216

  16. Beyond the mammography debate: a moderate perspective.

    PubMed

    Kaniklidis, C

    2015-06-01

    After some decades of contention, one can almost despair and conclude that (paraphrasing) "the mammography debate you will have with you always." Against that sentiment, in this review I argue, after reflecting on some of the major themes of this long-standing debate, that we must begin to move beyond the narrow borders of claim and counterclaim to seek consensus on what the balance of methodologically sound and critically appraised evidence demonstrates, and also to find overlooked underlying convergences; after acknowledging the reality of some residual and non-trivial harms from mammography, to promote effective strategies for harm mitigation; and to encourage deployment of new screening modalities that will render many of the issues and concerns in the debate obsolete. To these ends, I provide a sketch of what this looking forward and beyond the current debate might look like, leveraging advantages from abbreviated breast magnetic resonance imaging technologies (such as the ultrafast and twist protocols) and from digital breast tomosynthesis-also known as three-dimensional mammography. I also locate the debate within the broader context of mammography in the real world as it plays out not for the disputants, but for the stakeholders themselves: the screening-eligible patients and the physicians in the front lines who are charged with enabling both the acts of screening and the facts of screening at their maximally objective and patient-accessible levels to facilitate informed decisions. PMID:26089721

  17. Screening Mammography in Older Women: A Review

    PubMed Central

    Walter, Louise C.; Schonberg, Mara A.

    2015-01-01

    Importance Guidelines recommend individualizing screening mammography decisions for women 75 and older. However, little pragmatic guidance is available to inform this approach. Objective To provide an evidence-based approach to individualizing decision-making about screening mammography that considers older women's risk of breast cancer and the potential benefits and harms of screening in the context of varying life expectancies and preferences. Evidence Acquisition We searched PubMed for English-language studies in peer-reviewed journals published from January 1, 1990 to February 1, 2014 to identify risk factors for late-life breast cancer in women 65 and older and to quantify the benefits and harms of screening mammography for women 75 and older. Findings Age is the major risk factor for late-life breast cancer. In general, traditional breast cancer risk factors (e.g., age at first birth, age at menarche) that represent hormonal exposures in the distant past are less predictive of late-life breast cancer than factors indicating recent exposure to endogenous hormones (e.g., bone mass, obesity). None of the randomized trials of screening mammography included women over age 74, such that it is uncertain whether screening mammography is beneficial in these women. Observational data favor extending screening mammography to older women who have a life expectancy > 5-10 years. Modeling studies suggest approximately 2 fewer women per 1,000 die from breast cancer if women in their 70's continue biennial screening for 10 years, versus stopping screening at age 69. Potential benefits must be weighed with potential harms of continued screening over ten years, which include false-positive mammograms (~200 per 1,000 women screened) and overdiagnosis (~13 per 1,000 women screened). Providing these frequencies both verbally and graphically may help inform older women's decision-making. Conclusions and Relevance For women with less than a 5-10 year life expectancy

  18. 2D vs. 3D mammography observer study

    NASA Astrophysics Data System (ADS)

    Fernandez, James Reza F.; Hovanessian-Larsen, Linda; Liu, Brent

    2011-03-01

    Breast cancer is the most common type of non-skin cancer in women. 2D mammography is a screening tool to aid in the early detection of breast cancer, but has diagnostic limitations of overlapping tissues, especially in dense breasts. 3D mammography has the potential to improve detection outcomes by increasing specificity, and a new 3D screening tool with a 3D display for mammography aims to improve performance and efficiency as compared to 2D mammography. An observer study using a mammography phantom was performed to compare traditional 2D mammography with this ne 3D mammography technique. In comparing 3D and 2D mammography there was no difference in calcification detection, and mass detection was better in 2D as compared to 3D. There was a significant decrease in reading time for masses, calcifications, and normals in 3D compared to 2D, however, as well as more favorable confidence levels in reading normal cases. Given the limitations of the mammography phantom used, however, a clearer picture in comparing 3D and 2D mammography may be better acquired with the incorporation of human studies in the future.

  19. The Color of Leadership. Essays

    ERIC Educational Resources Information Center

    Jansen, Jonathan D.

    2005-01-01

    On July 1, 2000, the author became the first black dean of Education in the almost 100 year existence of the formidable University of Pretoria, South Africa. This essay offers a set of meditations on being a black dean in a white university at the birth of a post-apartheid democracy. There are many sides to this narrative. It is a story of leading…

  20. A Systematic Characterization of Cognitive Techniques for Learning from Textual and Pictorial Representations

    ERIC Educational Resources Information Center

    Ploetzner, Rolf; Lowe, Richard; Schlag, Sabine

    2013-01-01

    Pictorial representations can play a pivotal role in both printed and digital learning material. Although there has been extensive research on cognitive techniques and strategies for learning from text, the same cannot be said for static and dynamic pictorial representations. In this paper we propose a systematic characterization of cognitive…

  1. From Implicit to Explicit Representation in Children's Response to Pictorial Humor

    ERIC Educational Resources Information Center

    Puche-Navarro, Rebeca

    2009-01-01

    Two experiments examined pictorial humor as an unusual but legitimate way to approach the study of children's representational activity and the transition from implicit to explicit knowledge. In both experiments, the participants were 3- and 4-year-old children. Experiment 1 studied the understanding of two pictorial jokes using two conditions,…

  2. Mammography-oncogenecity at low doses.

    PubMed

    Heyes, G J; Mill, A J; Charles, M W

    2009-06-01

    Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 +/- 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 +/- 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

  3. Establishing a statewide mammography database in Arkansas: overcoming the barriers.

    PubMed

    Jazieh, Abdul Rahman

    2003-01-01

    To determine patterns of mammography utilization in Arkansas, the Arkansas Mammography Data Collection Project (MDCP) was established. The project's objective was to compile into one database statewide information about mammograms performed. All mammography centers were invited to participate in the project. Many barriers were encountered that were center related, data related, or personnel related; different interventions were implemented for each barrier. At the conclusion of the project, 92 out of 112 centers (82%) participated in the project, creating a database of 157,976 mammography data sets. Identifying and overcoming many of the barriers were crucial steps in the project's success. PMID:12552932

  4. Screening mammography. A risk versus risk decision

    SciTech Connect

    Ritenour, E.R.; Hendee, W.R.

    1989-01-01

    The potential risk of a radiologic procedure often is compared with the potential benefit of the procedure. While risk vs. benefit analysis has been useful as a step toward increased communication and understanding among radiologists, referring physicians, and the general public, it has the disadvantage that risk and benefit are fundamentally different quantities. Hence, their juxtaposition for purposes of comparison presents contextual difficulties. In this article, the concept is presented of comparing the risk of doing a procedure with the risk of choosing not to do the procedure. An example of risk vs. risk analysis of screening mammography for women over the age of 50 is given, with the conclusion that the risk of having yearly mammograms is less than 1/10 the risk of early death caused by failure to diagnose breast cancer by x-ray mammography. This approach to risk analysis would yield interesting data for examinations that are part of more complicated diagnostic pathways.19 references.

  5. Toward Clinically Compatible Phase-Contrast Mammography

    PubMed Central

    Scherer, Kai; Willer, Konstantin; Gromann, Lukas; Birnbacher, Lorenz; Braig, Eva; Grandl, Susanne; Sztrókay-Gaul, Anikó; Herzen, Julia; Mayr, Doris; Hellerhoff, Karin; Pfeiffer, Franz

    2015-01-01

    Phase-contrast mammography using laboratory X-ray sources is a promising approach to overcome the relatively low sensitivity and specificity of clinical, absorption-based screening. Current research is mostly centered on identifying potential diagnostic benefits arising from phase-contrast and dark-field mammography and benchmarking the latter with conventional state-of-the-art imaging methods. So far, little effort has been made to adjust this novel imaging technique to clinical needs. In this article, we address the key points for a successful implementation to a clinical routine in the near future and present the very first dose-compatible and rapid scan-time phase-contrast mammograms of both a freshly dissected, cancer-bearing mastectomy specimen and a mammographic accreditation phantom. PMID:26110618

  6. A glass-ceramic plate for mammography.

    SciTech Connect

    Johnson, J. A.; Schweizer, S.; Lubinsky, A. R.; Nuclear Engineering Division; Univ. of Paderborn; State Univ. of New York at Stony Brook

    2007-01-01

    We developed translucent glass-ceramic image plates for digital mammography. The glass ceramics are based on europium-doped fluorozirconate glasses, which were additionally doped with chlorine to initiate the nucleation of barium chloride nanoparticles therein. The X-ray image is stored in the form of stable electron-hole pairs, which can be read out afterwards with a scanning laser beam in a 'photostimulated luminescence' (PSL) process. Measurements of the required stimulating exposure, integrated PSL signal, and optical light spreading of the stimulating laser light were performed to allow projection of the detective quantum efficiency (DQE) for the proposed X-ray storage phosphor system. The projected DQE is compared with commercially available electronic mammography systems.

  7. Digital Mammography: Improvements in Breast Cancer Diagnostic

    SciTech Connect

    Montano Zetina, Luis Manuel

    2006-01-06

    X-ray mammography is the most sensitive imaging technique for early detection of breast cancer (diagnostics). It is performed by a radiological system equipped with a rotating molybdenum (Mo) anode tube with an additional Mo filter. In the production of X-ray, bremsstrahlung photons produce an intense diffuse radiation, affecting the contrast between normal and cancerous tissue. So it is known that a good mammographic imaging can help to detect cancer in the first stages avoiding surgery, amputation or even death. In the last years there has been some developments in new imaging techniques to improve the contrast spatial resolution between different tissues: digital imaging, or the so call digital mammography. Digital mammographic imaging is considered an improvement in the prevention of breast cancer due to the advantages it offers.

  8. The current approach to the diagnosis of vascular anomalies of the head and neck: A pictorial essay

    PubMed Central

    Gupta, Swati; Singh, Aarti; Prakash, Anjali; Ghosh, Sujoy; Narang, Poonam; Gupta, Sunita

    2015-01-01

    Throughout the years, various classifications have evolved for the diagnosis of vascular anomalies. However, it remains difficult to classify a number of such lesions. Because all hemangiomas were previously considered to involute, if a lesion with imaging and clinical characteristics of hemangioma does not involute, then there is no subclass in which to classify such a lesion, as reported in one of our cases. The recent classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA, 2014) has solved this problem by including non-involuting and partially involuting hemangioma in the classification. We present here five cases of vascular anomalies and discuss their diagnosis in accordance with the ISSVA (2014) classification. A non-involuting lesion should not always be diagnosed as a vascular malformation. A non-involuting lesion can be either a hemangioma or a vascular malformation depending upon its clinicopathologic and imaging characteristics. PMID:26125008

  9. Formation of ghost images due to metal objects on the surface of the patient's face: A pictorial essay.

    PubMed

    Ramos, Bárbara Couto; da Silva Izar, Bruna Raquel; Pereira, Jéssica Lourdes Costa; Souza, Priscilla Sena; Valerio, Claudia Scigliano; Tuji, Fabrício Mesquita; Manzi, Flávio Ricardo

    2016-03-01

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case n order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses. PMID:27051642

  10. Uncinate Process Variations and Their Relationship with Ostiomeatal Complex: A Pictorial Essay of Multidedector Computed Tomography (MDCT) Findings.

    PubMed

    Güngör, Gülay; Okur, Nazan; Okur, Erdoğan

    2016-01-01

    The ostiomeatal complex (OMC) is a key area for the drainage and ventilation of the paranasal sinuses. Stenosis created by inflammation and anatomic variations in this region causes an ideal ground for parasanal sinus infections, by preventing the drainage and ventilation of the sinuses. In today's diagnostics of paranasal sinus infections, the role of evaluation of OMC anatomical variations and soft tissue pathology has increased.. Knowing the anatomical details is important in terms of directing both medical and surgical treatment. The uncinate process (UP) constitutes the most important structure of the ostiomeatal complex, playing a role in mucociliary activity. UP variations can cause mucociliary drainage and ventilation problems, causing complications during surgery. Therefore, knowing and identifying their appearances in multidetector computed tomography (MDCT), the most frequently used radiological imaging method for these variations, becomes a very important consideration. PMID:27158282

  11. Ultrasound in obstructive lung diseases: the effect of airway obstruction on diaphragm kinetics. A short pictorial essay.

    PubMed

    Zanforlin, Alessandro; Smargiassi, Andrea; Inchingolo, Riccardo; Valente, Salvatore; Ramazzina, Emilio

    2015-12-01

    The ultrasound study of the chest is showing a continuous development. This technique could be helpful in managing several chest diseases, but it is limited to the acoustic windows provided by intercostal spaces and by the inability to study healthy lung parenchyma and all intra-parenchymal diseases such as chronic obstructive lung disease (COPD), because the interaction between ventilated lung and ultrasound generates only artifacts. Currently, there are few applications of ultrasound that are useful in COPD, with recent studies providing some innovation potentially useful in clinical practice. The similarity of the trend between the time/volume curve of spirometry and the M-mode representation of diaphragm during forced breath allowed to identify the M-mode Index of Obstruction (MIO), an index obtained from the ratio between forced diaphragmatic excursion in the first second (FEDE1, cm) and the maximal expiratory diaphragmatic excursion (EDEMax, cm). MIO has shown a linear correlation with the ratio between forced expiratory volume in the first second (FEV1) and vital capacity (VC), used in spirometry to identify airways obstruction. The value of MIO seems to be lower in patients affected by airways obstruction as showed by a recent study. The technique is easy to learn and fast to perform and the analysis could be provided with any ultrasound machine equipped with M-mode. In conclusion, these findings, if confirmed by other studies, could suggest a new add-on screening tool for obstructive lung diseases, in particular COPD, that could be performed during a routine abdominal ultrasound exam. PMID:26550063

  12. Uncinate Process Variations and Their Relationship with Ostiomeatal Complex: A Pictorial Essay of Multidedector Computed Tomography (MDCT) Findings

    PubMed Central

    Güngör, Gülay; Okur, Nazan; Okur, Erdoğan

    2016-01-01

    Summary The ostiomeatal complex (OMC) is a key area for the drainage and ventilation of the paranasal sinuses. Stenosis created by inflammation and anatomic variations in this region causes an ideal ground for parasanal sinus infections, by preventing the drainage and ventilation of the sinuses. In today’s diagnostics of paranasal sinus infections, the role of evaluation of OMC anatomical variations and soft tissue pathology has increased.. Knowing the anatomical details is important in terms of directing both medical and surgical treatment. The uncinate process (UP) constitutes the most important structure of the ostiomeatal complex, playing a role in mucociliary activity. UP variations can cause mucociliary drainage and ventilation problems, causing complications during surgery. Therefore, knowing and identifying their appearances in multidetector computed tomography (MDCT), the most frequently used radiological imaging method for these variations, becomes a very important consideration. PMID:27158282

  13. Extranodal involvement in lymphoma – A Pictorial Essay and Retrospective Analysis of 281 PET/CT studies

    PubMed Central

    Das, Jayanta; Ray, Soumendranath; Sen, Saugata; Chandy, Mammen

    2014-01-01

    Objective(s): The aim of this study is to evaluate the role of PET-CT in identification of different patterns of extranodal involvement in Hodgkin’s disease (HD) and Non-Hodgkin’s Lymphoma (NHL) and to enlist the common sites of extranodal involvement in each histological type and compare our results with the existing literature. Methods: In this retrospective study of 281 cases of lymphomas of various histologies, we illustrate the spectrum of PET/CT features of extranodal lymphoma (ENL) of commonly involved organs and compare our result with the literature. Result: Extranodal appearance in lymphoma is strikingly varied. Diffuse large B cell lymphoma (DLBCL) is the commonest histological subtype and gastrointestinal tract is the commonest anatomical subsite in NHL. Skeletal system is the commonest site for involvement in HD. Conclusion: A broad spectrum of extranodal organs is involved in various subtype of lymphoma which can be depicted in PET-CT in the most appropriate manner. Familiarity with the pattern of involvement is essential for comprehensive management. PMID:27408858

  14. Formation of ghost images due to metal objects on the surface of the patient's face: A pictorial essay

    PubMed Central

    Ramos, Bárbara Couto; da Silva Izar, Bruna Raquel; Pereira, Jéssica Lourdes Costa; Souza, Priscilla Sena; Valerio, Claudia Scigliano; Tuji, Fabrício Mesquita

    2016-01-01

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case n order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses. PMID:27051642

  15. Aural, visual, and pictorial stimulus formats in false recall.

    PubMed

    Beauchamp, Heather M

    2002-12-01

    The present investigation is an initial simultaneous examination of the influence of three stimulus formats on false memories. Several pilot tests were conducted to develop new category associate stimulus lists. 73 women and 26 men (M age=21.1 yr.) were in one of three conditions: they either heard words, were shown words, or were shown pictures highly related to critical nonpresented items. As expected, recall of critical nonpresented stimuli was significantly greater for aural lists than for visually presented words and pictorial images. These findings demonstrate that the accuracy of memory is influenced by the format of the information encoded. PMID:12530749

  16. Imaging of Retrosternal Space Lesions - A Pictorial Review.

    PubMed

    Chandrashekhara, S H; Rahul, Kumar; Handa, Nayha; Panda, Ananya

    2016-01-01

    The retrosternal region (RSS) can be involved by diverse lesions. The RSS is the region behind the sternum and anterior to the ascending aorta. It normally is less than 3 cm deep. Chest X-ray is usually the first imaging modality to raise a suspicion of RSS pathology; however computed tomography is the mainstay to delineate and characterize lesions in this location. Lesions in this location include thyroid, thymic and lymph node lesions; germ cell tumors and vascular lesions. Lesions arising from the sternum, lungs as well as the pleura can also involve this space. The pictorial review depicts the diverse spectrum of lesions in this location. PMID:27504144

  17. Extragenital endometriosis: assessment with MR imaging. A pictorial review.

    PubMed

    Menni, Katiuscia; Facchetti, Luca; Cabassa, Paolo

    2016-04-01

    Endometriosis is a gynaecologic disease characterized by endometrial tissue outside the uterine cavity. Commonly it affects the pelvic organs. When endometrial nodules or plaques are localized in sites other than the uterus or ovaries, it is termed extragenital endometriosis. Adequate pre-operative assessment is essential for treatment planning. MRI is a non-invasive method with high spatial resolution that allows the multiplanar evaluation of genital and extragenital endometriosis. Herein, we present a pictorial review of a variety of extragenital endometriosis cases, all of which can be encountered in clinical practice. PMID:26846303

  18. Imaging of Retrosternal Space Lesions – A Pictorial Review

    PubMed Central

    Chandrashekhara, S.H.; Rahul, Kumar; Handa, Nayha; Panda, Ananya

    2016-01-01

    Summary The retrosternal region (RSS) can be involved by diverse lesions. The RSS is the region behind the sternum and anterior to the ascending aorta. It normally is less than 3 cm deep. Chest X-ray is usually the first imaging modality to raise a suspicion of RSS pathology; however computed tomography is the mainstay to delineate and characterize lesions in this location. Lesions in this location include thyroid, thymic and lymph node lesions; germ cell tumors and vascular lesions. Lesions arising from the sternum, lungs as well as the pleura can also involve this space. The pictorial review depicts the diverse spectrum of lesions in this location. PMID:27504144

  19. Ground control failures. A pictorial view of case studies

    SciTech Connect

    Peng, S.S.

    2007-07-01

    The book shows, in pictorial views, many forms and/or stages of types of failures in mines, for instance, cutter, roof falls, and cribs. In each case, the year of occurrence is stated in the beginning so that the environment or technological background under which it occurred are reflected. The narrative than begins with the mining and geological conditions, followed by a description of the ground control problems and recommended solutions and results, if any. The sections cover failure of pillars, roof falls, longwall, roof bolting, multiple-seam mining, floor heave, longwall, flooding and weathering of coal, old workings, and shortwall and thin-seam plow longwall.

  20. Radiographic signs of gastrointestinal perforation in children: A pictorial review

    PubMed Central

    Awolaran, Olugbenga T.

    2015-01-01

    Plain abdominal radiographs remain an important aid for clinicians in the diagnosis of gastrointestinal perforation, especially in neonates and very sick children where clinical features of peritonitis may not be as prominent. Suggestive radiographic features are not always very obvious, especially when taken in the supine position and may lead to delayed or missed diagnosis. Through a pictorial review of plain radiographs, this article highlights a number of documented features of gastrointestinal perforation on X-ray in the paediatric setting, which increases the accuracy of diagnosis. PMID:26612119

  1. Authenticity and integrity of digital mammography images.

    PubMed

    Zhou, X Q; Huang, H K; Lou, S L

    2001-08-01

    Data security becomes more and more important in telemammography which uses a public high-speed wide area network connecting the examination site with the mammography expert center. Generally, security is characterized in terms of privacy, authenticity and integrity of digital data. Privacy is a network access issue and is not considered in this paper. We present a method, authenticity and integrity of digital mammography, here which can meet the requirements of authenticity and integrity for mammography image (IM) transmission. The authenticity and integrity for mammography (AIDM) consists of the following four modules. 1) Image preprocessing: To segment breast pixels from background and extract patient information from digital imaging and communication in medicine (DICOM) image header. 2) Image hashing: To compute an image hash value of the mammogram using the MD5 hash algorithm. 3) Data encryption: To produce a digital envelope containing the encrypted image hash value (digital signature) and corresponding patient information. 4) Data embedding: To embed the digital envelope into the image. This is done by replacing the least significant bit of a random pixel of the mammogram by one bit of the digital envelope bit stream and repeating for all bits in the bit stream. Experiments with digital IMs demonstrate the following. 1) In the expert center, only the user who knows the private key can open the digital envelope and read the patient information data and the digital signature of the mammogram transmitted from the examination site. 2) Data integrity can be verified by matching the image hash value decrypted from the digital signature with that computed from the transmitted image. 3) No visual quality degradation is detected in the embedded image compared with the original. Our preliminary results demonstrate that AIDM is an effective method for image authenticity and integrity in telemammography application. PMID:11513029

  2. Quantitative mammography contrast threshold test tool.

    PubMed

    Wagner, A J; Frey, G D

    1995-02-01

    Mammographic contrast is commonly evaluated by visualizing small objects of varying size or mass divided by projected area. These qualitative contrast determinations are commonly performed by imaging a phantom like the American College of Radiology accreditation phantom at clinical mammographic settings. However, this contrast assessment does not take into account the kVp of the machine. This work describes a quantitative mammography contrast threshold test tool which examines light object contrast on a uniform background for a contrast range of 0.32% to 1.38% at 25 kVp. For this mammography contrast threshold test tool, contrast is defined by delta I/I = loge (psi O/ psi b), where psi O is the target energy flux, and psi b is the background energy flux. Contrast threshold is defined as the lowest contrast value for which the objects are visible. Unlike traditional assessments of mammographic contrast, this measurement of contrast threshold is kVp corrected. The mammography contrast threshold test tool is constructed out of common plastics and provides a quantitative means of assessing contrast threshold for individual mammographic units and total mammographic systems. PMID:7565343

  3. [Film-screen combinations for mammography].

    PubMed

    Säbel, M; Aichinger, H

    1991-05-01

    Optimizing and standardizing mammography as well as its quality assurance are gaining in importance with regard to the screening programmes that are being initiated for the early detection of breast cancer. In Germany, the guidelines of the Bundesärztekammer, the directives implementing section 4 and section 16 of the Röntgenverordnung and the standards DIN 6868, Part 7 and 52 are available. The data in these standards concerning tolerances and guide values for physical variables of the imaging system are only partially consistent. This also applies to the comparison with the document "Quality criteria for x-ray exposures in medical diagnostics" of the Commission of the European Communities. The different statements concerning the switch-off value of the dose in particular, reflect an uncertainty as to how unsharpness and noise of the image receptor impair the medical value of the images. With regard to the increased demands for visual resolution capacity, it can be stated that the "Medical quality requirements" and the "Radiographic guide-lines" harmonize with one another only inadequately. Contrast is one of the most important image quality parameters in mammography. Practically no statement is made on this in the available documents. One reason for the present unsatisfactory situation is certainly the especially high demands placed on image quality in mammography. In the present paper, these points of criticism are discussed in detail and proposals for closer specification and better delineation of the physical image quality parameters are submitted. PMID:1878377

  4. Optimized exposure control in digital mammography

    NASA Astrophysics Data System (ADS)

    Shramchenko, Nataliya; Blin, Philippe; Mathey, Claude; Klausz, Remy

    2004-05-01

    A method for the determination of optimal operating points of digital mammography systems is described. The digital mammography equipment uses a flat panel detector and a bi-metal molybdenum/rhodium x-ray tube. An operating point is defined by the selection of the x-ray tube target material, x-ray filtration, kVp and detector entrance dose. Breast thickness and composition are estimated from a low dose pre-exposure, then used to index tables containing sets of operating points. The operating points are determined using a model of the image chain, which computes contrast to noise ratio (CNR) and average glandular dose (AGD) for all possible exposure conditions and breast thickness and composition combinations. The selected operating points are those which provide the required CNR for the lowest AGD. An AGD reduction of 30% to 50% can be achieved for comparable Image Quality, relative to current operating points. Resulting from the optimization process, the rhodium target is used in more than 75% of cases. Measurements of CNR and AGD have been performed on various tissue equivalent materials with good agreement between calculated and measured values. The proposed method provides full Image Quality benefit of digital mammography while minimizing dose to patients in a controlled and predictive way.

  5. Promoting screening mammography: insight or uptake?

    PubMed

    Keen, John D

    2010-01-01

    The US Preventive Services Task Force has emphasized individualized decision-making regarding participation in screening mammography for women ages 40 to 49. Positive public opinion regarding screening mammography is understandable given that screening advocates have heavily promoted the slogan "early detection saves lives" while ignoring screening harms. The goal of mammography screening advocates is to increase screening participation or uptake. The purpose of this paper is to promote physician and patient insight by presenting the age-related benefit and harms of screening. At age 50, routine screening saves approximately 1 woman per 1000 over 10 years. The life-saving proportion of screen-detected cancers is 5%, which means mammograms must detect 21 cancers to save one life. Almost half of screen-detected cancers represent pseudo-disease and would never become symptomatic yet alone lethal during a woman's lifetime. Consequently, 40- and 50-year-old women are 10 times more likely to experience overdiagnosis and overtreatment than to have their lives saved. Analysis of events and outcomes per single screening round for women ages 40 to 49 show that approximately 9600 screening mammograms, 960 diagnostic exams, and 90 to 140 biopsies are required to save one life. Given the substantial harms of screening, advocates should refocus their priority from promoting uptake to promoting insight. PMID:21057074

  6. Measuring pictorial balance perception at first glance using Japanese calligraphy.

    PubMed

    Gershoni, Sharon; Hochstein, Shaul

    2011-01-01

    According to art theory, pictorial balance acts to unify picture elements into a cohesive composition. For asymmetrical compositions, balancing elements is thought to be similar to balancing mechanical weights in a framework of symmetry axes. Assessment of preference for balance (APB), based on the symmetry-axes framework suggested in Arnheim R, 1974 Art and Visual Perception: A Psychology of the Creative Eye (Berkeley, CA: University of California Press), successfully matched subject balance ratings of images of geometrical shapes over unlimited viewing time. We now examine pictorial balance perception of Japanese calligraphy during first fixation, isolated from later cognitive processes, comparing APB measures with results from balance-rating and comparison tasks. Results show high between-task correlation, but low correlation with APB. We repeated the rating task, expanding the image set to include five rotations of each image, comparing balance perception of artist and novice participant groups. Rotation has no effect on APB balance computation but dramatically affects balance rating, especially for art experts. We analyze the variety of rotation effects and suggest that, rather than depending on element size and position relative to symmetry axes, first fixation balance processing derives from global processes such as grouping of lines and shapes, object recognition, preference for horizontal and vertical elements, closure, and completion, enhanced by vertical symmetry. PMID:23145242

  7. Painting cracks: A way to investigate the pictorial matter

    NASA Astrophysics Data System (ADS)

    Giorgiutti-Dauphiné, Frédérique; Pauchard, Ludovic

    2016-08-01

    An old painting generally exhibits a wide variety of crack patterns. From a strictly aesthetic point of view, cracks are undesirable; nevertheless, they can be seen as the fingerprints of the painting and provide valuable knowledge about the art piece. Precisely, the morphology of crack patterns can be related to the mechanical properties of the pictorial matter or they can reveal information about the methods used by the artist or the conditions of conservation. In the present paper, we show how drying dispersions of colloidal particles in a volatile solvent on a non-porous substrate provides a good candidate to study crack formation in a solid layer. We recover the crack patterns observed in paintings, and we investigate the role of the substrate, e.g., the sub-layer, and of the thickness of the layer in the crack spacing. We show how to deduce mechanical properties of a sub-layer, provided the thickness and the elastic modulus of the layer are known. These experiments aim to propose a potentially non-invasive method to deduce quantitative information about mechanical properties of a pictorial matter which could be of great interest for cultural heritage.

  8. Deficiency of molecular hydrogen in the disk of beta Pictoris.

    PubMed

    Lecavelier des Etangs, A; Vidal-Madjar, A; Roberge, A; Feldman, P D; Deleuil, M; André, M; Blair, W P; Bouret, J C; Désert, J M; Ferlet, R; Friedman, S; Hébrard, G; Lemoine, M; Moos, H W

    2001-08-16

    Molecular hydrogen (H2) is by far the most abundant material from which stars, protoplanetary disks and giant planets form, but it is difficult to detect directly. Infrared emission lines from H2 have recently been reported towards beta Pictoris, a star harbouring a young planetary system. This star is surrounded by a dusty 'debris disk' that is continuously replenished either by collisions between asteroidal objects or by evaporation of ices on Chiron-like objects. A gaseous disk has also been inferred from absorption lines in the stellar spectrum. Here we present the far-ultraviolet spectrum of beta Pictoris, in which H2 absorption lines are not seen. This allows us to set a very low upper limit on the column density of H2: N(H2) 6 x 10-4. As CO would be destroyed under ambient conditions in about 200 years (refs 9, 11), our result demonstrates that the CO in the disk arises from evaporation of planetesimals. PMID:11507632

  9. How Children's Mentalistic Theory Widens their Conception of Pictorial Possibilities.

    PubMed

    Gilli, Gabriella M; Ruggi, Simona; Gatti, Monica; Freeman, Norman H

    2016-01-01

    An interpretative theory of mind enables young children to grasp that people fulfill varying intentions when making pictures. We tested the hypothesis that in middle childhood a unifunctional conception of artists' intention to produce a picture widens to include artists' intention to display their pictures to others. Children aged between 5 and 10 years viewed a brief video of an artist deliberately hiding her picture but her intention was thwarted when her picture was discovered and displayed. By 8 years of age children were almost unanimous that a picture-producer without an intention to show her work to others cannot be considered to be an artist. Further exploratory studies centered on aspects of picture-display involving normal public display as well as the contrary intentions of hiding an original picture and of deceitfully displaying a forgery. Interviews suggested that the concept of exhibition widened to take others' minds into account viewers' critical judgments and effects of forgeries on viewers' minds. The approach of interpolating probes of typical possibilities between atypical intentions generated evidence that in middle childhood the foundations are laid for a conception of communication between artists' minds and viewers' minds via pictorial display. The combination of hypothesis-testing and exploratory opening-up of the area generates a new testable hypothesis about how an increasingly mentalistic approach enables children to understand diverse possibilities in the pictorial domain. PMID:26955360

  10. Screening Mammography Utilization in Tennessee Women: The Association with Residence

    ERIC Educational Resources Information Center

    Brown, Kathleen C.; Fitzhugh, Eugene C.; Neutens, James J.; Klein, Diane A.

    2009-01-01

    Context: Approximately 70% of US women over age 40 report mammography screening within 2 years. However, rates are likely to vary by age, income, educational level, and residence. Purpose: To describe the prevalence of screening mammography and associated factors in women living in rural and urban areas of Tennessee. Methods: Using pooled data…

  11. Psychosocial variables, external barriers, and stage of mammography adoption.

    PubMed

    Lauver, Diane Ruth; Henriques, Jeffrey B; Settersten, Lori; Bumann, Mary Carson

    2003-11-01

    Guided by H. Triandis's (1980) theory of behavior and the transtheoretical model, the study purpose was to examine differences in psychosocial variables and external conditions by stage of mammography adoption. Sampled from a statewide population, participants (N=509) were women aged 51-80. They had been contacted by telephone, screened for eligibility (e.g., no history of cancer or recent mammogram), and interviewed 3-6 months later. Higher utility beliefs, social influences, and practitioner interactions about mammography were associated with improved stage of adoption, as were lower negative affect and external barriers regarding mammography. Higher decisional balance scores, with and without negative affect toward mammography were associated with improved stage. Controlling for variables reflecting pros and cons, negative affect toward mammography further distinguished among stages. A richer set of pros and cons measures could explain screening more fully. PMID:14640864

  12. TL dosimetry for quality control of CR mammography imaging systems

    NASA Astrophysics Data System (ADS)

    Gaona, E.; Nieto, J. A.; Góngora, J. A. I. D.; Arreola, M.; Enríquez, J. G. F.

    The aim of this work is to estimate the average glandular dose with thermoluminescent (TL) dosimetry and comparison with quality imaging in computed radiography (CR) mammography. For a measuring dose, the Food and Drug Administration (FDA) and the American College of Radiology (ACR) use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, full field digital mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium flourohalideE We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated X-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose greater than 3.0 mGy without demonstrating improved image quality. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement for X-rays with a HVL (0.35-0.38 mmAl) and kVp (24-26) used in quality control procedures with ACR Mammography Accreditation Phantom.

  13. Essays on La Mujer. Anthology No. 1.

    ERIC Educational Resources Information Center

    Sanchez, Rosaura, Ed.; Cruz, Rosa Martinez, Ed.

    The 10 essays introduce some concepts and topics of particular concern and interest to those wishing to analyze the situation of the Chicana within her particular historical, social and economical context. Topics of the essays are: (1) the Chicana labor force; (2) the role of the Chicana within the student movement; (3) the Chicana and the Chicano…

  14. Essays on the Economics of Higher Education

    ERIC Educational Resources Information Center

    Tang, Hui-Hsuan

    2012-01-01

    This dissertation is comprised of two essays that broadly consider the role human capital plays in the matching process between individuals and institutions and builds on prior education literature that has found growing evidence that economic choices and opportunities are inextricably linked to human capital investment. The essays in this…

  15. Constitution 200: A Bicentennial Collection of Essays.

    ERIC Educational Resources Information Center

    Hepburn, Mary A., Ed.; And Others

    Constitutional essays which formed the basis of public assemblies throughout three states are compiled in this book. The first three essays consider the U.S. government principles of federalism, judicial review, and the separation of powers. Michael L. Benedict proposes that the question of ultimate sovereignty has been answered differently by…

  16. The "New" Age: A Bibliographic Essay.

    ERIC Educational Resources Information Center

    Chandler, Daniel Ross

    This bibliographic essay describes and discusses important books in a variety of thematic areas associated with the New Age Movement, which is a distinctive communicative phenomenon characterized by unconventional beliefs and activities. The essay argues that the single subject pervading the peculiar phenomena and puzzling thoughtful critics is…

  17. Dialects in Culture: Essays in General Dialectology.

    ERIC Educational Resources Information Center

    McDavid, Raven I., Jr.

    This is a collection of 60 essays on dialectology written in the period from 1942 to 1979. The essays fall into the categories of theoretical, applied, and critical dialectology. Some of the more recent titles include: "System and Variety in American English,""Dialect Differences and Social Differences in an Urban Society,""Dialectology and the…

  18. Essays on Industrial Organization and Political Economy

    ERIC Educational Resources Information Center

    Camara, Odilon Roberto VG de a

    2009-01-01

    This thesis presents three essays on industrial organization and political economy. In the first essay, I show how the attributes of a managerial workforce affect firms' placement decisions and wage offers, and managers' quit decisions. My OLG model features two division managers and a CEO, where each executive may be at a different point in his…

  19. 2012 Cliff Weiss Memorial Essay Contest Winners

    ERIC Educational Resources Information Center

    Techniques: Connecting Education and Careers (J3), 2012

    2012-01-01

    This article presents the winners of the 2012 Cliff Weiss Memorial Essay Contest. They are Naim Owens from Washington, DC, and Colissa Menke from Warrensburg, Missouri. The 2012 essay topic is "How do you feel CTE prepares individuals, including yourself, for a future career?"

  20. Students' Experiences with an Automated Essay Scorer

    ERIC Educational Resources Information Center

    Scharber, Cassandra; Dexter, Sara; Riedel, Eric

    2008-01-01

    The purpose of this research is to analyze preservice teachers' use of and reactions to an automated essay scorer used within an online, case-based learning environment called ETIPS. Data analyzed include post-assignment surveys, a user log of students' actions within the cases, instructor-assigned scores on final essays, and interviews with four…

  1. Framing the Past; Essays on Art Education.

    ERIC Educational Resources Information Center

    Soucy, Donald, Ed.; Stankiewicz, Mary Ann, Ed.

    This collection of essays presents the history of art education from a variety of perspectives. Traditional and revisionist issues are seen from broad overviews and through specific concerns. Textual analysis, cultural transmission, and prominent philosophies are discussed. Thirteen essays include: (1) "A History of Art Education Histories"…

  2. Mammography Screening – as of 2013

    PubMed Central

    Heywang-Koebrunner, S.; Bock, K.; Heindel, W.; Hecht, G.; Regitz-Jedermann, L.; Hacker, A.; Kaeaeb-Sanyal, V.

    2013-01-01

    Introduction: Since 2008 the German Mammography Screening Programme has been available throughout Germany to all women aged between 50 and 69. The programme strictly follows the European Guidelines. There are controversial discussions in the media as well as in the specialised press. Materials and Methods: Overview of the available data with regard to an evaluation of randomised studies and with regard to quality-assured screening programmes in accordance with EU Guidelines (including data from 18 screening countries). Results: Positive effects of screening: reduction in mortality, less invasive treatment. Negative effects: False-positive diagnoses and biopsy recommendations, so-called overdiagnoses, radiation dose. Limits of screening: Interval carcinomas, incomplete reduction in mortality. A mathematical synopsis of the latest publications from the European screening programmes with the diagnosis rates in Germany determined from > 4.6 million screening examinations produces the following: a total of 10 000 mammograms are created for 1000 women (P) taking part in the Mammography Screening Programme (each of whom undergoes 10 mammograms in 20 years). Overall, the risk of triggering breast cancer through a mammogram is very clearly below the annual natural risk of suffering from breast cancer. In the German screening, of these 1000 women, an average of 288 women are called back once in 20 years as a result of changes that are ultimately benign (< 3 % per cycle). Of these, 74 of the 288 women undergo a biopsy due to a benign change (false-positive biopsy recommendations, usually punch or vacuum biopsies). According to EUROSCREEN, 71 carcinomas develop among participants (56 are discovered in the screening, 15 in the interval), and 67 carcinomas among non-participants (N-P) (in some cases, several years later) during this period. The 4 additional diagnoses among the Ps are referred to as overdiagnoses, as they do not contribute to a reduction in mortality

  3. A mathematical model for spatial orientation from pictorial perspective displays

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.; Smith, Stephen

    1988-01-01

    A previously formulated mathematical model, describing how observers reconstruct three-dimensional spatial layouts from perspective projections, has been extended to more complex situations. The model assumes that the observer has a priori knowledge of certain characteristics of the viewed objects, like size, shape, or parallelism or perpendicularity of lines or planes. These assumptions are used in a three-dimensional process to reconstruct a spatial layout that `best matches' the perceived lines of sight to the object coordinates. Sources of errors and biases in this process are specified and their effects on model outputs are discussed. An experiment, in which eight subjects judged the relative direction of one object with respect to another, has been conducted to validate the model. The model has been found to generally reproduce the systematic trends of the experimental results and also has provided an analytical explanation for them. The mathematical model is expected to be a useful tool in analyzing and developing pictorial perspective flight displays.

  4. BETA PICTORIS DISK HIDES GIANT ELLIPTICAL RING SYSTEM

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA Hubble Space Telescope false-color, visible-light picture of one side of the edge-on dust disk around the star Beta Pictoris. Knots in the disk (marked A,B,C,D) are interpreted as rings of dust, seen edge-on. Image credit: NASA and Paul Kalas (Space Telescope Science Institute) A still frame from a computer simulation, which shows a circumstellar dust disk highly perturbed by the gravitational pull of a bypassing star. The gray solid area represents the initial shape and size of the undisturbed disk. In the simulation, the gravity of the passing star rearranges the orbit of each particle, setting up an elliptical ring system that may have survived for the last 100,000 years since the impact occurred.

  5. Formation and dynamical history of the beta Pictoris system

    NASA Astrophysics Data System (ADS)

    Wyatt, M.

    2014-09-01

    The structure of the beta Pic disk holds many clues to its formation and dynamical history. In particular there is strong evidence for sculpting by the beta Pic-b planet. For example, a warp in the disk at 80au is thought to be driven by the secular perturbations of that planet, and scattering of comets by beta Pic-b is thought to be the origin of the Falling Evaporating Bodies. A clump in the disk coincident with the warp, also at ~80au, provides clues to the outer planetary system which for now is poorly constrained. One possible origin for the clump is in trapping of comets into resonance with an outer planet currently at ~60au, with an alternative scenario being a giant impact between planetary embryos. This talk will consider the various disk structures and what they tell us about the formation and dynamical history of the beta Pictoris system.

  6. United States radiological health activities: inspection results of mammography facilities

    PubMed Central

    Spelic, DC; Kaczmarek, RV; Hilohi, M; Belella, S

    2007-01-01

    Purpose: The Mammography Quality Standards Act (MQSA) was enacted in 1992 to set national standards for high-quality mammography, including standards for mammographic X-ray equipment, patient dose, clinical image quality, and related technical parameters. The MQSA also requires minimum qualifications for radiologic technologists, interpreting physicians and medical physicists, mandates acceptable practices for quality-control, quality-assurance, and requires processes to audit medical outcomes. This paper presents the findings of MQSA inspections of facilities, which characterize significant factors affecting mammography quality in the United States. Materials and Methods: Trained inspectors collected data regarding X-ray technical factors, made exposure measurements for the determination of mean glandular dose (MGD), evaluated image quality, and inspected the quality of the film-processing environment. The average annual facility and total U.S. screening exam workloads were computed using workload data reported by facilities. Results: Mammography facilities have made technical improvements as evidenced by a narrower distribution of doses, higher phantom-film background optical densities associated with higher phantom image-quality scores, and better film processing. It is estimated that approximately 36 million screening mammography exams were conducted in 2006, a rate that is almost triple the exam volume estimated for 1997. Digital mammography (DM) is now in use at approximately 14% (1,191 of 8,834) of MQSA-certified mammography facilities. The results indicate that DM can offer lower dose to the patient while providing comparable or better image quality. PMID:21614276

  7. Three essays on access pricing

    NASA Astrophysics Data System (ADS)

    Sydee, Ahmed Nasim

    In the first essay, a theoretical model is developed to determine the time path of optimal access price in the telecommunications industry. Determining the optimal access price is an important issue in the economics of telecommunications. Setting a high access price discourages potential entrants; a low access price, on the other hand, amounts to confiscation of private property because the infrastructure already built by the incumbent is sunk. Furthermore, a low access price does not give the incumbent incentives to maintain the current network and to invest in new infrastructures. Much of the existing literature on access pricing suffers either from the limitations of a static framework or from the assumption that all costs are avoidable. The telecommunications industry is subject to high stranded costs and, therefore, to address this issue a dynamic model is imperative. This essay presents a dynamic model of one-way access pricing in which the compensation involved in deregulatory taking is formalized and then analyzed. The short run adjustment after deregulatory taking has occurred is carried out and discussed. The long run equilibrium is also analyzed. A time path for the Ramsey price is shown as the correct dynamic price of access. In the second essay, a theoretical model is developed to determine the time path of optimal access price for an infrastructure that is characterized by congestion and lumpy investment. Much of the theoretical literature on access pricing of infrastructure prescribes that the access price be set at the marginal cost of the infrastructure. In proposing this rule of access pricing, the conventional analysis assumes that infrastructure investments are infinitely divisible so that it makes sense to talk about the marginal cost of investment. Often it is the case that investments in infrastructure are lumpy and can only be made in large chunks, and this renders the marginal cost concept meaningless. In this essay, we formalize a model of

  8. The geographic distribution of mammography resources in Mississippi

    PubMed Central

    Nichols, Elizabeth N.; Bradley, Denae L.; Zhang, Xu; Faruque, Fazlay; Duhé, Roy J.

    2014-01-01

    OBJECTIVE: To determine whether the availability of mammography resources affected breast cancer incidence rates, stage of disease at initial diagnosis, mortality rates and/or mortality-to-incidence ratios throughout Mississippi. METHODS: Mammography facilities were geocoded and the numbers of residents residing within a thirty minute drive of a mammography facility were calculated. Other data were extracted from the Mississippi Cancer Registry, the U.S. Census, and the Mississippi Behavioral Risk Factor Surveillance Survey (BRFSS). RESULTS & DISCUSSION: There were no statistically-significant differences between breast cancer incidence rates in Black versus White females in Mississippi; however, there were significant differences in the use of mammography, percentages of advanced-stage initial diagnoses, mortality rates, and mortality-to-incidence ratios, where Black females fared worse in each category. No statistically-significant correlations were observed between breast cancer outcomes and the availability of mammography facilities. The use of mammography was negatively correlated with advanced stage of disease at initial diagnosis. By combining Black and White subsets, a correlation between mammography use and improved survival was detected; this was not apparent in either subset alone. There was also a correlation between breast cancer mortality-to-incidence ratios and the percentage of the population living below the poverty level. CONCLUSIONS: The accessibility and use of mammography resources has a greater impact on breast cancer in Mississippi than does the geographic resource distribution per se. Therefore, intensified mammography campaigns to reduce the percentage of advanced-stage breast cancers initially diagnosed in Black women, especially in communities with high levels of poverty, are warranted in Mississippi. PMID:24678379

  9. Pictorial cigarette pack warnings: a meta-analysis of experimental studies

    PubMed Central

    Noar, Seth M; Hall, Marissa G; Francis, Diane B; Ribisl, Kurt M; Pepper, Jessica K; Brewer, Noel T

    2016-01-01

    Objective To inform international research and policy, we conducted a meta-analysis of the experimental literature on pictorial cigarette pack warnings. Data sources We systematically searched 7 computerised databases in April 2013 using several search terms. We also searched reference lists of relevant articles. Study selection We included studies that used an experimental protocol to test cigarette pack warnings and reported data on both pictorial and text-only conditions. 37 studies with data on 48 independent samples (N=33 613) met criteria. Data extraction and synthesis Two independent coders coded all study characteristics. Effect sizes were computed from data extracted from study reports and were combined using random effects meta-analytic procedures. Results Pictorial warnings were more effective than text-only warnings for 12 of 17 effectiveness outcomes (all p<0.05). Relative to text-only warnings, pictorial warnings (1) attracted and held attention better; (2) garnered stronger cognitive and emotional reactions; (3) elicited more negative pack attitudes and negative smoking attitudes and (4) more effectively increased intentions to not start smoking and to quit smoking. Participants also perceived pictorial warnings as being more effective than text-only warnings across all 8 perceived effectiveness outcomes. Conclusions The evidence from this international body of literature supports pictorial cigarette pack warnings as more effective than text-only warnings. Gaps in the literature include a lack of assessment of smoking behaviour and a dearth of theory-based research on how warnings exert their effects. PMID:25948713

  10. Preliminary experience with monoenergetic photon mammography

    SciTech Connect

    Johnston, R.E.; Washburn, D.; Pisano, E.; Thomlinson, W.C.; Chapman, D.; Gmur, N.F.; Zhong, Zhong; Sayers, D.

    1995-12-31

    We are using a beam port at the National Synchrotron Light Source facility at Brookhaven National Laboratory as a source of monoenergetic photons. The photon source is radiation from a bending magnet on the X-ray storage ring and provides a usable X-ray spectrum from 5 keV to over 50 keV. A tunable crystal monochromotor is used for energy selection. The beam is 79mm wide and 0.5 mm high. We imaged the ACR mammography phantom and a contrast-detail phantom using a phosphor plate as the unaging detector. Phantom images were obtained at 16, 18, 20 and 22 keV. Phantom thickness varied from 15 mm to 82 mm. These images were compared to images obtained with a conventional dedicated mammography unit. Subjective preliminary results show that image contrast of the monoenergetic images is similar to those obtained from the conventional x-ray source with somewhat sharper and cleaner images from the monoenergetic source. Quantitative analysis shows that the monoenergetic images have improved contrast compared to the polyenergetic derived images. Entrance skin dose measurements show a factor of 5 to 10 times less radiation for the monoenergetic images with equivalent or better contrast Although there remain a number of technical problems to be addressed and much more work to be done, we are encouraged to further explore the use of monoenergetic imaging.

  11. An assessment of American Indian women's mammography experiences

    PubMed Central

    2010-01-01

    Background Mortality from breast cancer has increased among American Indian/Alaskan Native (AI/AN) women. Despite this alarming reality, AI/AN women have some of the lowest breast cancer screening rates. Only 37% of eligible AI/AN women report a mammogram within the last year and 52% report a mammogram within the last two years compared to 57% and 72% for White women. The experiences and satisfaction surrounding mammography for AI/AN women likely are different from that of women of other racial/ethnic groups, due to cultural differences and limited access to Indian Health Service sponsored mammography units. The overall goals of this study are to identify and understand the mammography experiences and experiential elements that relate to satisfaction or dissatisfaction with mammography services in an AI/AN population and to develop a culturally-tailored AI/AN mammography satisfaction survey. Methods and Design The three project aims that will be used to guide this work are: 1) To compare the mammography experiences and satisfaction with mammography services of Native American/Alaska Native women with that of Non-Hispanic White, Hispanic, and Black women, 2) To develop and validate the psychometric properties of an American Indian Mammography Survey, and 3) To assess variation among AI/AN women's assessments of their mammography experiences and mammography service satisfaction. Evaluations of racial/ethnic differences in mammography patient satisfaction have received little study, particularly among AI/AN women. As such, qualitative study is uniquely suited for an initial examination of their experiences because it will allow for a rich and in-depth identification and exploration of satisfaction elements. Discussion This formative research is an essential step in the development of a validated and culturally tailored AI/AN mammography satisfaction assessment. Results from this project will provide a springboard from which a maximally effective breast cancer

  12. CR mammography: Design and implementation of a quality control program

    SciTech Connect

    Moreno-Ramirez, A.; Brandan, M. E.; Villasenor-Navarro, Y.; Galvan, H. A.; Ruiz-Trejo, C.

    2012-10-23

    Despite the recent acquisition of significant quantities of computed radiography CR equipment for mammography, Mexican regulations do not specify the performance requirements for digital systems such as those of CR type. The design of a quality control program QCP specific for CR mammography systems was thus considered relevant. International protocols were taken as reference to define tests, procedures and acceptance criteria. The designed QCP was applied in three CR mammography facilities. Important deficiencies in spatial resolution, noise, image receptor homogeneity, artifacts and breast thickness compensation were detected.

  13. ``Water Drops'' Essays Available for Public Radio

    NASA Astrophysics Data System (ADS)

    Black, Peter E.

    2007-11-01

    ``Water Drops'' are 90-second essays on water science, hydrology, culture, history, organizations, law, and policy that have aired weekly on radio station WRVO-FM in Oswego, N.Y., since January 2006. Created for the lay public with a basic understanding of Earth science, the 133 essays now are available on Public Radio Exchange (http://www.prx.org) for free use by public radio stations, according to terms set forth at the Exchange Web site that include citing appropriate credits. If aired weekly, there are enough essays for 2.5 years of radio programming.

  14. A proposal for a national mammography database: content, purpose, and value.

    PubMed

    Osuch, J R; Anthony, M; Bassett, L W; DeBor, M; D'Orsi, C; Hendrick, R E; Linver, M; Smith, R

    1995-06-01

    A national mammography database is a centralized, computerized method of data collection consisting of two possible parts: a national mammography audit and a system for monitoring and tracking patients. A national mammography audit refers to collecting and analyzing medical audit data of individual mammography practices at a national level and is a critical step in improving the interpretive component of mammography. The monitoring and tracking component refers to a centralized system that provides women and physicians with a recruitment and follow-up mechanism to optimize participation in mammography services. Both parts of a national mammography database represent important components in the improvement of mammography quality. However, unique scientific, legal, and fiscal concerns are important to consider before establishing a national mammography database. PMID:7754870

  15. The negative impact of MQSA (Mammography Quality Standards Act) on rural mammography programs.

    PubMed

    Inman, M

    1998-01-01

    Since Roentgen's discovery in 1895, physicians and scientists have found ways to use x-ray to evaluate and diagnose disease. In 1960, Dr. Richard Egan modified an x-ray machine to image the breast, for example. In 1982, one study found that deaths from breast cancer could be reduced 40 percent by using screening mammography. In 1991, Congress appropriated $90 million for breast cancer research, a figure that rose to $406 million several years later. The Mammography Quality Standards Act (MQSA), passed in 1992, requires all mammography facilities to meet minimum quality standards for equipment, radiologists, physicists and technologists. Regulations require extensive records of medical audit and outcome analysis, personnel qualification and medical reporting. Inspection and certification are now the responsibility of the Food and Drug Administration (FDA). Although they ensure compliance with the law, these inspections cost each facility $1,549 annually and the average cost to reach compliance with MQSA is $18,000. These fees are easily absorbed by high-volume centers but are burdensome for smaller, lower volume centers. Screening exams, to be useful, must be simple, accessible and cost-effective. MQSA's regulations have added significant costs and in most cases, the smaller centers will be forced to raise prices or discontinue offering mammography for a segment of the population with little or no other recourse for screening. The FDA should look for ways to perform more cost-effective inspections that still enforce regulations and monitor quality. Inspections should be unannounced and fines raised for violations. Implementation costs must be more realistic and the amount of paperwork reduced. PMID:10181470

  16. Digital mammography, cancer screening: Factors important for image compression

    NASA Technical Reports Server (NTRS)

    Clarke, Laurence P.; Blaine, G. James; Doi, Kunio; Yaffe, Martin J.; Shtern, Faina; Brown, G. Stephen; Winfield, Daniel L.; Kallergi, Maria

    1993-01-01

    The use of digital mammography for breast cancer screening poses several novel problems such as development of digital sensors, computer assisted diagnosis (CAD) methods for image noise suppression, enhancement, and pattern recognition, compression algorithms for image storage, transmission, and remote diagnosis. X-ray digital mammography using novel direct digital detection schemes or film digitizers results in large data sets and, therefore, image compression methods will play a significant role in the image processing and analysis by CAD techniques. In view of the extensive compression required, the relative merit of 'virtually lossless' versus lossy methods should be determined. A brief overview is presented here of the developments of digital sensors, CAD, and compression methods currently proposed and tested for mammography. The objective of the NCI/NASA Working Group on Digital Mammography is to stimulate the interest of the image processing and compression scientific community for this medical application and identify possible dual use technologies within the NASA centers.

  17. A novel method to assess incompleteness of mammography reports.

    PubMed

    Gimenez, Francisco J; Wu, Yirong; Burnside, Elizabeth S; Rubin, Daniel L

    2014-01-01

    Mammography has been shown to improve outcomes of women with breast cancer, but it is subject to inter-reader variability. One well-documented source of such variability is in the content of mammography reports. The mammography report is of crucial importance, since it documents the radiologist's imaging observations, interpretation of those observations in terms of likelihood of malignancy, and suggested patient management. In this paper, we define an incompleteness score to measure how incomplete the information content is in the mammography report and provide an algorithm to calculate this metric. We then show that the incompleteness score can be used to predict errors in interpretation. This method has 82.6% accuracy at predicting errors in interpretation and can possibly reduce total diagnostic errors by up to 21.7%. Such a method can easily be modified to suit other domains that depend on quality reporting. PMID:25954448

  18. A Novel Method to Assess Incompleteness of Mammography Reports

    PubMed Central

    Gimenez, Francisco J.; Wu, Yirong; Burnside, Elizabeth S.; Rubin, Daniel L.

    2014-01-01

    Mammography has been shown to improve outcomes of women with breast cancer, but it is subject to inter-reader variability. One well-documented source of such variability is in the content of mammography reports. The mammography report is of crucial importance, since it documents the radiologist’s imaging observations, interpretation of those observations in terms of likelihood of malignancy, and suggested patient management. In this paper, we define an incompleteness score to measure how incomplete the information content is in the mammography report and provide an algorithm to calculate this metric. We then show that the incompleteness score can be used to predict errors in interpretation. This method has 82.6% accuracy at predicting errors in interpretation and can possibly reduce total diagnostic errors by up to 21.7%. Such a method can easily be modified to suit other domains that depend on quality reporting. PMID:25954448

  19. Influence of advertisement on women's attitudes toward mammography screening.

    PubMed

    Collins, C; Davis, L S; Rentz, K; Vannoy, D

    1997-01-01

    This project represents an effort to incorporate a feminist perspective into research on mammography screening. The purpose of this study was to assess women's attitudes toward four advertisements designed to encourage mammography screening. The goal was to create awareness about women's attitudes toward mammography advertisements in order to encourage the development of more effective and responsive motivational materials. The results indicated that each ad communicated different messages about the seriousness of breast cancer and the efficacy of mammography in detecting early breast cancer. Each ad also affected women differently regarding their feelings of control over breast cancer, their perceived loss of sex appeal resulting from a breast cancer diagnosis, and their general fear of breast cancer. PMID:9384078

  20. Variability and errors when applying the BIRADS mammography classification.

    PubMed

    Boyer, Bruno; Canale, Sandra; Arfi-Rouche, Julia; Monzani, Quentin; Khaled, Wassef; Balleyguier, Corinne

    2013-03-01

    To standardize mammographic reporting, the American College of Radiology mammography developed the Breast Imaging Reporting and Data System (BIRADS) lexicon. However, wide variability is observed in practice in the application of the BIRADS terminology and this leads to classification errors. This review analyses the reasons for variations in BIRADS mammography, describes the types of errors made by readers with illustrated examples, and details BIRADS category 3 which is the most difficult category to use in practice. PMID:22483607

  1. Three essays on utility regulation

    NASA Astrophysics Data System (ADS)

    Hlasny, Vladimir

    To induce utilities in the gas distribution market to operate efficiently, US states have deployed consumer choice programs, price caps, and variations of sliding scale plans. My first essay studies the impact of these restructuring and deregulation efforts on consumer rates, using panel data from a custom survey of state commissions and the Department of Energy. I estimate the residential, small commercial and industrial price equations jointly, and use instrumental variables to control for the potentially endogenous demand and status of deregulation. Consumer choice programs lower the prices by 2.2-20.1% compared to the rate of return regulation, benefiting industrial consumers the most and households the least. These effects appear even one to two years prior to the programs' implementation, and become stronger over time. Price caps lower all prices by 0.0-20.0%, with the same ranking. The impacts of sliding scale plans are close to zero, between -2.6% and +4.0% The second paper evaluates health damages caused by air concentrations of SO2 under three alternative environmental policies leading to identical aggregate emissions: emission caps, a nationwide emission tax, and a system of tradable emission allowances such as the one currently used in the US. The numerical model of the industry finds generators' output, participation in energy trade and SO2 abatement effort under each policy. The resulting SO2 concentrations are used to derive the aggregate health damages using estimates in the medical literature. SO2 concentrations vary across policies even when the aggregate emissions are the same. These variations translate into substantially different losses for any individual state, and, nationwide, to hundreds of millions of dollars of difference in aggregate damages. Emission caps are found to lead to the lowest damages, outperforming the currently used system of allowances by 452 million. A uniform emission tax leads to very similar damages as the system of

  2. X-ray source for mammography

    DOEpatents

    Logan, C.M.

    1994-12-20

    An x-ray source is described utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms. 6 figures.

  3. Characterizing mammography reports for health analytics

    SciTech Connect

    Rojas, Carlos C; Patton, Robert M; Beckerman, Barbara G

    2010-01-01

    As massive collections of digital health data are becoming available, the opportunities for large scale automated analysis increase. In particular, the widespread collection of detailed health information is expected to help realize a vision of evidence-based public health and patient-centric health care. Within such a framework for large scale health analytics we describe several methods to characterize and analyze free-text mammography reports, including their temporal dimension, using information retrieval, supervised learning, and classical statistical techniques. We present experimental results with a large collection of mostly unlabeled reports that demonstrate the validity and usefulness of the approach, since these results are consistent with the known features of the data and provide novel insights about it.

  4. X-ray source for mammography

    DOEpatents

    Logan, Clinton M.

    1994-01-01

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  5. Contrast-Enhanced Digital Mammography and Angiogenesis

    SciTech Connect

    Rosado-Mendez, I.; Palma, B. A.; Villasenor, Y.; Benitez-Bribiesca, L.; Brandan, M. E.

    2007-11-26

    Angiogenesis could be a means for pouring contrast media around tumors. In this work, optimization of radiological parameters for contrast-enhanced subtraction techniques in mammography has been performed. A modification of Lemacks' analytical formalism was implemented to model the X-ray absorption in the breast with contrast medium and detection by a digital image receptor. Preliminary results of signal-to-noise ratio analysis show the advantage of subtracting two images taken at different energies, one prior and one posterior to the injection of contrast medium. Preliminary experimental results using a custom-made phantom have shown good agreement with calculations. A proposal is presented for the clinical application of the optimized technique, which aims at finding correlations between angiogenesis indicators and dynamic variables of contrast medium uptake.

  6. Image toggling saves time in mammography.

    PubMed

    Drew, Trafton; Aizenman, Avi M; Thompson, Matthew B; Kovacs, Mark D; Trambert, Michael; Reicher, Murray A; Wolfe, Jeremy M

    2016-01-01

    When two images are perfectly aligned, even subtle differences are readily detected when the images are "toggled" back and forth in the same location. However, substantial changes between two photographs can be missed if the images are misaligned ("change blindness"). Nevertheless, recent work from our lab, testing nonradiologists, suggests that toggling misaligned photographs leads to superior performance compared to side-by-side viewing (SBS). In order to determine if a benefit of toggling misaligned images may be observed in clinical mammography, we developed an image toggling technique where pairs of new and prior breast imaging exam images could be efficiently toggled back and forth. Twenty-three radiologists read 10 mammograms evenly divided in toggle and SBS modes. The toggle mode led to a 6-s benefit in reaching a decision [[Formula: see text], [Formula: see text

  7. Instrumentation optimization for positron emission mammography

    SciTech Connect

    Moses, William W.; Qi, Jinyi

    2003-06-05

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast.

  8. [Future of mammography-based imaging].

    PubMed

    Schulz-Wendtland, R; Wittenberg, T; Michel, T; Hartmann, A; Beckmann, M W; Rauh, C; Jud, S M; Brehm, B; Meier-Meitinger, M; Anton, G; Uder, M; Fasching, P A

    2014-03-01

    Mammography is the central diagnostic method for clinical diagnostics of breast cancer and the breast cancer screening program. In the clinical routine complementary methods, such as ultrasound, tomosynthesis and optional magnetic resonance imaging (MRI) are already combined for the diagnostic procedure. Future developments will utilize investigative procedures either as a hybrid (combination of several different imaging modalities in one instrument) or as a fusion method (the technical fusion of two or more of these methods) to implement fusion imaging into diagnostic algorithms. For screening there are reasonable hypotheses to aim for studies that individualize the diagnostic process within the screening procedure. Individual breast cancer risk prediction and individualized knowledge about sensitivity and specificity for certain diagnostic methods could be tested. The clinical implementation of these algorithms is not yet in sight. PMID:24570108

  9. Triple-energy contrast enhanced digital mammography

    NASA Astrophysics Data System (ADS)

    Puong, Sylvie; Milioni de Carvalho, Pablo; Muller, Serge

    2010-04-01

    With the injection of iodine, Contrast Enhanced Digital Mammography (CEDM) provides functional information about breast tumour angiogenesis that can potentially help in cancer diagnosis. In order to generate iodine images in which the gray level is proportional to the iodine thickness, temporal and dual-energy approaches have already been considered. The dual-energy method offers the advantage of less patient motion artifacts and better comfort during the exam. However, this approach requires knowledge of the breast thickness at each pixel. Generally, as compression is applied, the breast thickness at each pixel is taken as the compression thickness. Nevertheless, in the breast border region, this assumption is not correct anymore and this causes inaccuracies in the iodine image. Triple-Energy CEDM could overcome these limitations by providing supplemental information in the form of a third image acquired with a different spectrum than the other two. This precludes the need of a priori knowledge of the breast thickness. Moreover, with Triple-Energy CEDM, breast thickness and glandularity maps could potentially be derived. In this study, we first focused on the method to recombine the three images in order to generate the iodine image, analyzing the performance of either quadratic, cubic or conic recombination functions. Then, we studied the optimal acquisition spectra in order to maximize the iodine SDNR in the recombined image for a given target total glandular dose. The concept of Triple-Energy CEDM was validated on simulated textured images and poly-energetic images acquired with a conventional X-ray mammography tube.

  10. Vascular anomalies: A pictorial review of nomenclature, diagnosis and treatment

    PubMed Central

    Nosher, John L; Murillo, Philip G; Liszewski, Mark; Gendel, Vyacheslav; Gribbin, Christopher E

    2014-01-01

    Vascular anomalies, including vascular malformations and tumors, are frequently straightforward to detect; however, accurate diagnosis and appropriate treatment are often challenging. Misdiagnosis of these lesions can lead clinicians in the wrong direction when treating these patients, which can have unfavorable results. This review presents an overview of the classification systems that have been developed for the diagnosis of vascular lesions with a focus on the imaging characteristics. Pictorial examples of each lesion on physical examination, as well as non-invasive and minimally invasive imaging are presented. An overview of the endovascular treatment of these lesions is also given. In some cases, vascular anomalies may be associated with an underlying syndrome and several of the most commonly encountered syndromes are discussed. Understanding of the classification systems, familiarity with the treatment options and knowledge of the associated syndromes are essential for all physicians working with this patient population. The approach to the described entities necessitates an organized multi-disciplinary team effort, with diagnostic imaging playing an increasingly important role in the proper diagnosis and a combined interventional radiologic and surgical treatment method showing promising results. PMID:25276311

  11. Haptics disambiguates vision in the perception of pictorial relief

    NASA Astrophysics Data System (ADS)

    Wijntjes, M. W. A.; Volcic, R.; Pont, S. C.; Koenderink, J. J.; Kappers, A. M. L.

    2009-02-01

    In this study we demonstrate that touch decreases the ambiguity in a visual image. It has been previously found that visual perception of three-dimensional shape is subject to certain variations. These variations can be described by the affine transformation. While the visual system thus seems unable to capture the Euclidean structure of a shape, touch could potentially be a useful source to disambiguate the image. Participants performed a so-called 'attitude task' from which the structure of the perceived three-dimensional shape was calculated. One group performed the task with only vision and a second group could touch the stimulus while viewing it. We found that the consistency within the haptics+vision group was higher than in the vision-only group. Thus, haptics decreases the visual ambiguity. Furthermore, we found that the touched shape was consistently perceived as having more relief than the untouched the shape. It was also found that the direction of affine shear differences within the two groups was more consistent when touch was used. We thus show that haptics has a significant influence on the perception of pictorial relief.

  12. Braking the Gas in the β Pictoris Disk

    NASA Astrophysics Data System (ADS)

    Fernández, Rodrigo; Brandeker, Alexis; Wu, Yanqin

    2006-05-01

    The star β Pictoris hosts the best studied circumstellar disk to date. Nonetheless, a long-standing puzzle has been around since the detection of metallic gas in the disk: radiation pressure from the star should blow the gas away, yet the observed motion is consistent with Keplerian rotation. In this work we search for braking mechanisms that can resolve this discrepancy. We find that all species affected by radiation force are largely ionized and dynamically coupled into a single fluid by Coulomb collisions, reducing the radiation force on species feeling the strongest acceleration. For a gas of solar composition, the effective radiation force still exceeds gravity, while a gas of enhanced carbon abundance could be self-braking. We also explore two other braking agents: collisions with dust grains and neutral gas. Grains surrounding β Pic are photoelectrically charged to a positive electrostatic potential. If a significant fraction of the grains are carbonaceous (10% in the midplane and larger at higher altitudes), ions can be slowed down to satisfy the observed velocity constraints. For neutral gas to brake the ion fluid, we find a minimum required mass ~0.03 M⊕, consistent with observed upper limits on the hydrogen column density and substantially reduced relative to previous estimates. Our results favor a scenario in which metallic gas is generated by grain evaporation in the disk, perhaps during grain-grain collisions. We exclude a primordial origin for the gas but cannot rule out its production by falling evaporating bodies near the star.

  13. Development of a stereo 3-D pictorial primary flight display

    NASA Technical Reports Server (NTRS)

    Nataupsky, Mark; Turner, Timothy L.; Lane, Harold; Crittenden, Lucille

    1989-01-01

    Computer-generated displays are becoming increasingly popular in aerospace applications. The use of stereo 3-D technology provides an opportunity to present depth perceptions which otherwise might be lacking. In addition, the third dimension could also be used as an additional dimension along which information can be encoded. Historically, the stereo 3-D displays have been used in entertainment, in experimental facilities, and in the handling of hazardous waste. In the last example, the source of the stereo images generally has been remotely controlled television camera pairs. The development of a stereo 3-D pictorial primary flight display used in a flight simulation environment is described. The applicability of stereo 3-D displays for aerospace crew stations to meet the anticipated needs for 2000 to 2020 time frame is investigated. Although, the actual equipment that could be used in an aerospace vehicle is not currently available, the lab research is necessary to determine where stereo 3-D enhances the display of information and how the displays should be formatted.

  14. The Beta Pictoris Circumstellar Disk (5202; 2ND Visit)

    NASA Astrophysics Data System (ADS)

    Trauger, John

    1994-01-01

    We propose new methods to examine the circumstellar disk around Beta Pictoris in order to determine its radial profile, and hence (in combination with IRAS data) to fix its albedo and temperature profile. These observations will extend previous extensive ground based coronagraphic observations, and models by members of the science team. The data will enable us to understand better the central clearing in the disk and whether it is caused by sublimation or possible planet formation. They will also constrain the geometric propertie of the disk including its inclination angle, vertical thickness and radial profile. Such observations limit models for the dynamics of the disk, includin its velocity dispersion and hence mass distribution, and radial mass transport mechanisms. If density waves or clear zones are observed, they will give indirect evidence for the presence of massive bodies (planets) in the disk. Th observations involve a combination of roll deconvolution, polarizers and PSF modelling in order to allow the central stellar image and associated scattered light to be subtracted. Ultraviolet observations will constrain the particle size distribution and the composition of the disk. The observations require the new capabilities in WFPC2 provided by the absence of bleeding across columns, as well as its UV capabilities.

  15. Space Telescope Imaging Spectrograph Coronagraphic Observations of β Pictoris

    NASA Astrophysics Data System (ADS)

    Heap, Sara R.; Lindler, Don J.; Lanz, Thierry M.; Cornett, Robert H.; Hubeny, Ivan; Maran, S. P.; Woodgate, Bruce

    2000-08-01

    We present new coronagraphic images of β Pictoris obtained with the Space Telescope Imaging Spectrograph (STIS) in 1997 September. The high-resolution images (0.1") clearly detect the circumstellar disk as close to the star as 0.75", corresponding to a projected radius of 15 AU. The images define the warp in the disk with greater precision and at closer radii to β Pic than do previous observations. They show that the warp can be modeled by the projection of two components: the main disk and a fainter component, which is inclined to the main component by 4°-5° and extends only as far as ~4" from the star. We interpret the main component as arising primarily in the outer disk and the tilted component as defining the inner region of the disk. The observed properties of the warped inner disk are inconsistent with a driving force from stellar radiation. However, warping induced by the gravitational potential of one or more planets is consistent with the data. Using models of planet-warped disks constructed by Larwood & Papaloizou, we derive possible masses of the perturbing object. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  16. Two Essays in Financial Economics

    NASA Astrophysics Data System (ADS)

    Putnam, Kyle J.

    The following dissertation contains two distinct empirical essays which contribute to the overall field of Financial Economics. Chapter 1, entitled "The Determinants of Dynamic Dependence: An Analysis of Commodity Futures and Equity Markets," examines the determinants of the dynamic equity-commodity return correlations between five commodity futures sub-sectors (energy, foods and fibers, grains and oilseeds, livestock, and precious metals) and a value-weighted equity market index (S&P 500). The study utilizes the traditional DCC model, as well as three time-varying copulas: (i) the normal copula, (ii) the student's t copula, and (iii) the rotated-gumbel copula as dependence measures. Subsequently, the determinants of these various dependence measures are explored by analyzing several macroeconomic, financial, and speculation variables over different sample periods. Results indicate that the dynamic equity-commodity correlations for the energy, grains and oilseeds, precious metals, and to a lesser extent the foods and fibers, sub-sectors have become increasingly explainable by broad macroeconomic and financial market indicators, particularly after May 2003. Furthermore, these variables exhibit heterogeneous effects in terms of both magnitude and sign on each sub-sectors' equity-commodity correlation structure. Interestingly, the effects of increased financial market speculation are found to be extremely varied among the five sub-sectors. These results have important implications for portfolio selection, price formation, and risk management. Chapter 2, entitled, "US Community Bank Failure: An Empirical Investigation," examines the declining, but still pivotal role, of the US community banking industry. The study utilizes survival analysis to determine which accounting and macroeconomic variables help to predict community bank failure. Federal Deposit Insurance Corporation and Federal Reserve Bank data are utilized to compare 452 community banks which failed between

  17. 37 CFR 253.8 - Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural works. 253.8 Section 253.8 Patents... BROADCASTING § 253.8 Terms and rates of royalty payments for the use of published pictorial, graphic,...

  18. 37 CFR 253.8 - Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural works. 253.8 Section 253.8 Patents... BROADCASTING § 253.8 Terms and rates of royalty payments for the use of published pictorial, graphic,...

  19. 37 CFR 253.8 - Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Terms and rates of royalty payments for the use of published pictorial, graphic, and sculptural works. 253.8 Section 253.8 Patents... BROADCASTING § 253.8 Terms and rates of royalty payments for the use of published pictorial, graphic,...

  20. Young Children's Knowledge of the Representational Function of Pictorial Symbols: Development across the Preschool Years in Three Cultures

    ERIC Educational Resources Information Center

    Callaghan, Tara C.; Rochat, Philippe; Corbit, John

    2012-01-01

    Three- to 5-year-old children's knowledge that pictures have a representational function for others was investigated using a pictorial false-belief task. In Study 1, children passed the task at around 4 years old, and performance was correlated with standard false-belief and pictorial symbol tasks. In Study 2, the performance of children from two…

  1. Technology-Aided Pictorial Cues to Support the Performance of Daily Activities by Persons with Moderate Alzheimer's Disease

    ERIC Educational Resources Information Center

    Lancioni, Giulio E.; Perilli, Viviana; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Cassano, Germana; Pinto, Katia; Minervini, Mauro G.; Oliva, Doretta

    2012-01-01

    We developed a technology-aided intervention strategy relying on pictorial cues alone or in combination with verbal instructions and assessed these two versions of the strategy with three persons with moderate Alzheimer's disease. In Section I of the study, the strategy version with pictorial cues plus verbal instructions was compared with an…

  2. Three essays in energy and environmental economics

    NASA Astrophysics Data System (ADS)

    Redlinger, Michael

    This thesis exploits the boom in U.S. oil and gas production to explore several empirical questions in environmental and energy economics. In the first essay, statistical techniques are employed to evaluate learning-by-doing in the Bakken Shale Play. Furthermore, the essay demonstrates organizational forgetting and knowledge spillovers among firms. The results show rates of learning in an important sector the U.S. economy and may have broader lessons for productivity gains and losses. The second essay investigates interfirm learning economies in oil well drilling in terms of productivity improvements and increases in environmental safety. The empirical results improve our understanding of how interfirm relationships influence productivity as well as the drivers of environmental incidents. Lastly, the third essay analyzes the impacts of stricter environmental regulations on oil production and well drilling in North Dakota. The results have particular relevance for policymakers seeking to understand the trade-offs between resource development and environmental quality. These three essays ultimately expand our knowledge of how learning economies occur and the effects of environmental regulations on economic activity.

  3. Do Social Network Characteristics Predict Mammography Screening Practices?

    PubMed Central

    Allen, Jennifer D.; Stoddard, Anne M.; Sorensen, Glorian C.

    2010-01-01

    Background Many breast cancer screening programs are based on the assumption that dissemination of information through social networks and the provision of social support are effective strategies for promoting mammography use. This paper examines the prospective relationship between social network characteristics and breast cancer screening practices among employed women. Methods Women age 40 and over employed in 26 worksites participating in a randomized intervention trial completed baseline and two-year follow-up assessments. These analyses include women in the embedded cohort (n = 1,475). Measures included social network characteristics (size, social influences and support), breast cancer screening practices, and socio-demographic characteristics. Adherence to screening guidelines at follow-up (mammogram within the past two years) was modeled as a function of social network characteristics at baseline. Results The majority of women in this sample were adherent with mammography screening guidelines at baseline. Baseline adherence explained the vast majority of variation in screening practices at follow-up. Only after removing the effects of previous mammography screening did we find statistically significant relationships between network characteristics and screening status. Specifically, among women age 40–51, subjective norms and encouragement by family/friends to have a mammogram at baseline were each significantly associated with screening adherence at follow-up (OR = 2.20 and 1.18, respectively). For women age 52+, the perception that screening was normative among one’s peers was associated with increased likelihood of recent mammography at follow-up (OR = 1.46). Conclusions Previous mammography use is strongly predictive of future screening. Among employed women with high baseline screening rates, the impact of social network characteristics was modest. As previous use of screening is highly associated with future use, programs should focus on reaching

  4. Essays on Macroeconomics and Oil

    NASA Astrophysics Data System (ADS)

    Cakir, Nida

    In these essays, I examine (i) the empirical methods that are widely used in the literature to measure total factor productivity growth and (ii) the impact of nationalization on productivity in the oil industry. The first chapter, which is an ongoing work with SHI, Wei, investigates two empirical measures, quantity-based (primal) measure and price-based (dual) measure, of total factor productivity growth. My co-author and I analyze how these two measures are affected by output market imperfection or variable capacity utilization. We find that under constant-returns-to-scale production function assumption, existence of the imperfect competition in the output market creates a gap between the measured TFP growth and the true TFP growth, no matter which method is used. However, theoretically, it does not affect the equivalence between the two measures. Under variable capacity utilization, we show that constant-returns-to-scale assumption is almost enough to guarantee the validity of the two methods in correctly capturing the true TFP growth. In the second and third chapters, I analyze the link between nationalization and productivity. The second chapter documents the trends in expropriation acts, and evaluates the impact of expropriations on labor productivity of resource-rich developing countries in the oil industry. In the first part of this chapter, I investigate the trends in the expropriation acts that took place in 102 developing countries during the period 1922-2006. I find that more than half of the acts occurred between 1970 and 1976, there has been an increase in the number of expropriations in recent years, and the extractive sector including petroleum is more likely to be expropriated. Motivated by these facts, in the second part, I examine the oil industry in a period of widespread expropriations, the 1970s. In a sample of major oil-producing countries including OPEC and non-OPEC members, I show that losses in relative labor productivity after

  5. Three essays on auction markets

    NASA Astrophysics Data System (ADS)

    Shunda, Nicholas James

    This dissertation contains a series of theoretical investigations of auction markets. The essays it contains cover wholesale electricity markets, a popular selling mechanism on eBay, and supplier entry into multi-unit procurement auctions. The study in Chapter 1 compares the procurement cost-minimizing and productive efficiency performance of the auction mechanism used by independent system operators in wholesale electricity auction markets in the U.S. with that of a proposed alternative. The current practice allocates energy contracts as if the auction featured a discriminatory final payment method when, in fact, the markets are uniform price auctions. The proposed alternative explicitly accounts for the market-clearing price during the allocation phase. We find that the proposed alternative largely outperforms the current practice on the basis of procurement costs in the context of simple auction markets featuring both day-ahead and real-time auctions and that the procurement cost advantage of the alternative is complete when we simulate the effects of increased competition. We also find that a tradeoff between the objectives of procurement cost minimization and productive efficiency emerges in our simple auction markets and persists in the face of increased competition. The study in Chapter 2 considers a possible rationale for an auction with a buy price. In an auction with a buy price, the seller provides bidders with an option to end the auction early by accepting a transaction at a posted price. The "Buy-It-Now" option on eBay is a leading example of an auction with a buy price. The study develops a model of an auction with a buy price in which bidders use the auction's reserve price and buy price to formulate a reference price. The model both explains why a revenue-maximizing seller would want to augment her auction with a buy price and demonstrates that the seller sets a higher reserve price when she can affect the bidders' reference price through the

  6. 42 CFR 405.535 - Special rule for nonparticipating physicians and suppliers furnishing screening mammography...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... suppliers furnishing screening mammography services before January 1, 2002. 405.535 Section 405.535 Public... Special rule for nonparticipating physicians and suppliers furnishing screening mammography services before January 1, 2002. The provisions in this section apply for screening mammography services...

  7. 42 CFR 405.534 - Limitation on payment for screening mammography services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Limitation on payment for screening mammography... for Determining Reasonable Charges § 405.534 Limitation on payment for screening mammography services... January 1, 1991 until December 31, 2001. Screening mammography services provided after December 31,...

  8. 42 CFR 413.123 - Payment for screening mammography performed by hospitals on an outpatient basis.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Payment for screening mammography performed by... SKILLED NURSING FACILITIES Specific Categories of Costs § 413.123 Payment for screening mammography... mammographies performed by hospitals. (b) Payment to hospitals for outpatient services. Payment to hospitals...

  9. The Assessment of the Likelihood of Mammography Usage with Relevant Factors among Women with Disabilities

    ERIC Educational Resources Information Center

    Kung, Pei-Tseng; Tsai, Wen-Chen; Chiou, Shang-Jyh

    2012-01-01

    Research that identifies the determinants of low mammography use among disabled people is scant. This study examines the determining factors related to the low usage of mammography among women with disabilities. To identify the barriers that prevent women with disabilities from participating in mammography screening can help authorities conceive…

  10. 42 CFR 405.535 - Special rule for nonparticipating physicians and suppliers furnishing screening mammography...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... suppliers furnishing screening mammography services before January 1, 2002. 405.535 Section 405.535 Public... Special rule for nonparticipating physicians and suppliers furnishing screening mammography services before January 1, 2002. The provisions in this section apply for screening mammography services...

  11. 42 CFR 405.535 - Special rule for nonparticipating physicians and suppliers furnishing screening mammography...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... suppliers furnishing screening mammography services before January 1, 2002. 405.535 Section 405.535 Public... Special rule for nonparticipating physicians and suppliers furnishing screening mammography services before January 1, 2002. The provisions in this section apply for screening mammography services...

  12. 42 CFR 405.534 - Limitation on payment for screening mammography services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Limitation on payment for screening mammography... for Determining Reasonable Charges § 405.534 Limitation on payment for screening mammography services... January 1, 1991 until December 31, 2001. Screening mammography services provided after December 31,...

  13. 42 CFR 413.123 - Payment for screening mammography performed by hospitals on an outpatient basis.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Payment for screening mammography performed by... SKILLED NURSING FACILITIES Specific Categories of Costs § 413.123 Payment for screening mammography... mammographies performed by hospitals. (b) Payment to hospitals for outpatient services. Payment to hospitals...

  14. 42 CFR 413.123 - Payment for screening mammography performed by hospitals on an outpatient basis.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Payment for screening mammography performed by... SKILLED NURSING FACILITIES Specific Categories of Costs § 413.123 Payment for screening mammography... mammographies performed by hospitals. (b) Payment to hospitals for outpatient services. Payment to hospitals...

  15. 42 CFR 405.534 - Limitation on payment for screening mammography services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Limitation on payment for screening mammography... for Determining Reasonable Charges § 405.534 Limitation on payment for screening mammography services... January 1, 1991 until December 31, 2001. Screening mammography services provided after December 31,...

  16. 42 CFR 413.123 - Payment for screening mammography performed by hospitals on an outpatient basis.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Payment for screening mammography performed by... SKILLED NURSING FACILITIES Specific Categories of Costs § 413.123 Payment for screening mammography... mammographies performed by hospitals. (b) Payment to hospitals for outpatient services. Payment to hospitals...

  17. 42 CFR 405.534 - Limitation on payment for screening mammography services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Limitation on payment for screening mammography... for Determining Reasonable Charges § 405.534 Limitation on payment for screening mammography services... January 1, 1991 until December 31, 2001. Screening mammography services provided after December 31,...

  18. 42 CFR 405.535 - Special rule for nonparticipating physicians and suppliers furnishing screening mammography...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... suppliers furnishing screening mammography services before January 1, 2002. 405.535 Section 405.535 Public... Special rule for nonparticipating physicians and suppliers furnishing screening mammography services before January 1, 2002. The provisions in this section apply for screening mammography services...

  19. 75 FR 70011 - Guidance for Industry, Mammography Quality Standards Act Inspectors, and Food and Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ...The Food and Drug Administration (FDA) is announcing the availability of the guidance entitled ``The Mammography Quality Standards Act Final Regulations: Modifications and Additions to Policy Guidance Help System 13.'' This document is intended to assist mammography facilities and their personnel in meeting the requirements of the Mammography Quality Standards Act (MQSA)...

  20. Mammography screening. Benefits, harms, and informed choice.

    PubMed

    Jørgensen, Karsten Juhl

    2013-04-01

    The rationale for breast cancer screening with mammography is deceptively simple: catch it early and reduce mortality from the disease and the need for mastectomies. But breast cancer is a complex problem, and complex problems rarely have simple solutions. Breast screening brings forward the time of diagnosis only slightly compared to the lifetime of a tumour, and screen-detected tumours have a size where metastases are possible. A key question is if screening can prevent metastases, and if the screen-detected tumours are small enough to allow breast conserving surgery rather than mastectomy. A mortality reduction can never justify a medical intervention in its own right, but must be weighed against the harms. Overdiagnosis is the most important harm of breast screening, but has gained wider recognition only in recent years. Screening leads to the detection and treatment of breast cancers that would otherwise never have been detected because they grow very slowly or not at all and would not have been detected in the woman's lifetime in the absence of screening. Screening therefore turns women into cancer patients unnecessarily, with life-long physical and psychological harms. The debate about the justification of breast screening is therefore not a simple question of whether screening reduces breast cancer mortality. This dissertation quantifies the primary benefits and harms of screening mammography. Denmark has an unscreened "control group" because only two geographical regions offered screening over a long time-period, which is unique in an international context. This was used to study breast cancer mortality, overdiagnosis, and the use of mastectomies. Also, a systematic review of overdiagnosis in five other countries allowed us to show that about half of the screen-detected breast cancers are overdiagnosed. An effect on breast cancer mortality is doubtful in today's setting, and overdiagnosis causes an increase in the use of mastectomies. These findings are

  1. Optimizing Imaging Instruments for Emission Mammography

    NASA Astrophysics Data System (ADS)

    Weinberg, Irving N.

    1996-05-01

    Clinical studies have demonstrated that radiotracer methods can noninvasively detect breast cancers in vivo(L.P. Adler, J.P.Crowe, N.K. Al-Kaisis, et al, Radiology 187,743-750 (1993)) (I. Khalkhali, I. Mena, E. Jouanne, et al, J. Am. Coll. Surg. 178, 491-497 (1994)). Due to spatial resolution and count efficiency considerations, users of conventional nuclear medicine instruments have had difficulty in detecting subcentimeter cancers. This limitation is unfortunate, since cancer therapy is generally most efficacious when tumor diameter at detection is less than a centimeter. A more subtle limitation of conventional nuclear medicine imaging instruments is that they are poorly suited to guiding interventions. With the assistance of C.J. Thompson from McGill University, and the CEBAF Detector Physics Group, we have explored the possibility of configuring detectors for nuclear medicine imaging devices into geometries that resemble conventional x-ray mammography cameras(I.N. Weinberg, U.S.Patent 5,252,830 (1993)). Phantom and pilot clinical studies suggest that applying breast compression within such geometries may offer several advantages(C.J. Thompson, K. Murthy, I.N. Weinberg, et al, Med. Physics 21, 259-538 (1994)): For coincident detection of positron emitters, efficiency and spatial resolution are improved by bringing the detectors very close to the source (the breast tumor). For single-photon detection, attenuation due to overlying tissue is reduced. Since, for a high-efficiency collimator, spatial resolution worsens with increasing source to collimator distance, adoption of compression allows more efficient collimators to be employed. Economics are favorable in that detectors can be deployed in the region of interest, rather than around the entire body, and that such detectors can be mounted in conventional mammographic gantries. The application of conventional mammographic geometry promises to assist physicians in conducting radiotracer-guided biopsies, and in

  2. Satellite teleradiology test bed for digital mammography

    NASA Astrophysics Data System (ADS)

    Barnett, Bruce G.; Dudding, Kathryn E.; Abdel-Malek, Aiman A.; Mitchell, Robert J.

    1996-05-01

    Teleradiology offers significant improvement in efficiency and patient compliance over current practices in traditional film/screen-based diagnosis. The increasing number of women who need to be screened for breast cancer, including those in remote rural regions, make the advantages of teleradiology especially attractive for digital mammography. At the same time, the size and resolution of digital mammograms are among the most challenging to support in a cost effective teleradiology system. This paper will describe a teleradiology architecture developed for use with digital mammography by GE Corporate Research and Development in collaboration with Massachusetts General Hospital under National Cancer Institute (NCI/NIH) grant number R01 CA60246-01. The testbed architecture is based on the Digital Imaging and Communications in Medicine (DICOM) standard, created by the American College of Radiology and National Electrical Manufacturers Association. The testbed uses several Sun workstations running SunOS, which emulate a rural examination facility connected to a central diagnostic facility, and uses a TCP-based DICOM application to transfer images over a satellite link. Network performance depends on the product of the bandwidth times the round- trip time. A satellite link has a round trip of 513 milliseconds, making the bandwidth-delay a significant problem. This type of high bandwidth, high delay network is called a Long Fat Network, or LFN. The goal of this project was to quantify the performance of the satellite link, and evaluate the effectiveness of TCP over an LFN. Four workstations have Sun's HSI/S (High Speed Interface) option. Two are connected by a cable, and two are connected through a satellite link. Both interfaces have the same T1 bandwidth (1.544 Megabits per second). The only difference was the round trip time. Even with large window buffers, the time to transfer a file over the satellite link was significantly longer, due to the bandwidth-delay. To

  3. Essays on refining markets and environmental policy

    NASA Astrophysics Data System (ADS)

    Oladunjoye, Olusegun Akintunde

    This thesis is comprised of three essays. The first two essays examine empirically the relationship between crude oil price and wholesale gasoline prices in the U.S. petroleum refining industry while the third essay determines the optimal combination of emissions tax and environmental research and development (ER&D) subsidy when firms organize ER&D either competitively or as a research joint venture (RJV). In the first essay, we estimate an error correction model to determine the effects of market structure on the speed of adjustment of wholesale gasoline prices, to crude oil price changes. The results indicate that market structure does not have a strong effect on the dynamics of price adjustment in the three regional markets examined. In the second essay, we allow for inventories to affect the relationship between crude oil and wholesale gasoline prices by allowing them to affect the probability of regime change in a Markov-switching model of the refining margin. We find that low gasoline inventory increases the probability of switching from the low margin regime to the high margin regime and also increases the probability of staying in the high margin regime. This is consistent with the predictions of the competitive storage theory. In the third essay, we extend the Industrial Organization R&D theory to the determination of optimal environmental policies. We find that RJV is socially desirable. In comparison to competitive ER&D, we suggest that regulators should encourage RJV with a lower emissions tax and higher subsidy as these will lead to the coordination of ER&D activities and eliminate duplication of efforts while firms internalize their technological spillover externality.

  4. Blue Marble Space Institute essay contest

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-04-01

    The Blue Marble Space Institute of Science, based in Seattle, Wash., is inviting college students to participate in its essay contest. Essays need to address the question, "In the next 100 years, how can human civilization prepare for the long-term changes to the Earth system that will occur over the coming millennium?" According to the institute, the purpose of the contest is "to stimulate creative thinking relating to space exploration and global issues by exploring how changes in the Earth system will affect humanity's future."

  5. Influence of Detector Radiation Damage on CR Mammography Quality Control.

    PubMed

    Moriwaki, Atsumi; Ishii, Mie; Terazono, Shiho; Arao, Keiko; Ishii, Rie; Sanada, Taizo; Yoshida, Akira

    2016-05-01

    Recently, radiation damage to the detector apparatus employed in computed radiography (CR) mammography has become problematic. The CR system and the imaging plate (IP) applied to quality control (QC) program were also used in clinical mammography in our hospital, and the IP to which radiation damage has occurred was used for approximately 5 years (approximately 13,000 exposures). We considered using previously acquired QC image data, which is stored in a server, to investigate the influence of radiation damage to an IP. The mammography unit employed in this study was a phase contrast mammography (PCM) Mermaid (KONICA MINOLTA) system. The QC image was made newly, and it was output in the film, and thereafter the optical density of the step-phantom image was measured. An input (digital value)-output (optical density) conversion curve was plotted using the obtained data. The digital values were then converted to optical density values using a reference optical density vs. digital value curve. When a high radiation dose was applied directly, radiation damage occurred at a position on the IP where no object was present. Daily QC for mammography is conducted using an American College of Radiology (ACR) accreditation phantom and acrylic disc, and an environmental background density measurement is performed as one of the management indexes. In this study, the radiation damage sustained by the acrylic disc was shown to differ from that of the background. Thus, it was revealed that QC results are influenced by radiation damage. PMID:27211088

  6. Response costs of mammography adherence: Iranian women’s perceptions

    PubMed Central

    Khodayarian, Mahsa; Mazloomi-Mahmoodabad, Seyed Saied; Lamyian, Minoor; Morowatisharifabad, Mohammad Ali; Tavangar, Hossein

    2016-01-01

    Background: Mammography as the most common secondary prevention method has known to be helpful in detecting breast cancer at the early stages. Low level of participation among women toward mammography uptake due to cultural beliefs is a great concern. This study aimed at exploring the perceptions of women about response costs of mammography adherence (MA) in Yazd, Iran. Methods: A qualitative study using semi-structured interviews was performed. Fourteen women,one oncology nurse, and a breast cancer survivor were purposefully interviewed. Interviews were transcribed verbatim and analyzed by directed content analysis method based on protection motivation theory (PMT). Results: One main theme was emerged from the analysis namely called "response costs".Two main categories were also emerged from the data; (1) psychological barriers with six subcategories including "embarrassment," "worry about being diagnosed with cancer," "preoccupation with underlying disease," "misconception about mammography," "need for an accompanying person," and "internalizing the experiences of the others," and (2) maladaptive coping modes which encompassed three subcategories: "religious faith," "fatalism," and"avoidance and denial." Conclusion: Useful information was provided about the response costs of mammography utilization based on the perceptions of women. Cognitive barriers may be decreased by conducting modifications in women’s awareness and attitude toward MA as well as changing the national health system infrastructures. Incorporating religious and cultural belief systems into MA educational programs through motivational messages is recommended. PMID:27386423

  7. Scatter radiation intensities around full-field digital mammography units.

    PubMed

    Judge, M A; Keavey, E; Phelan, N

    2013-01-01

    The aim of this study was to investigate the scatter radiation intensity around digital mammography systems and apply these data to standard shielding calculations to reveal whether shielding design of existing breast screening rooms is adequate for the use of digital mammography systems. Three digital mammography systems from GE Healthcare, Hologic and Philips were employed in the study. A breast-equivalent phantom was imaged under clinical workload conditions and scatter radiation intensities around the digital mammography systems were measured for a range of angles in three planes using an ionisation chamber. The results were compared with those from previous studies of film-screen systems. It may be deduced from the results that scattering in the backward direction is significant for all three systems, while scattering in the forward direction can be significant for some planes around the GE and Hologic systems. Measurements at typical clinical settings on each system revealed the Philips system to have markedly lower scatter radiation intensities than the other systems. Substituting the measured scattered radiation intensity into shielding calculations yielded barrier requirements similar to those already in place at the screening centres operating these systems. Current radiation protection requirements based on film-screen technology remain sufficient when applied to rooms with digital mammography installations and no alteration is required to the structural shielding. PMID:23239693

  8. On the Power of Fine Arts Pictorial Imagery in Science Education

    NASA Astrophysics Data System (ADS)

    Galili, Igal

    2013-08-01

    The paper describes and illustrates the potential of using pictorial artistic images in supporting teaching scientific concepts and the nature of science. In the first part, the case of Giotto's fresco of stigmatization of St. Francis is described within the interpretation of relationship between the figures as between an object and its mirror image. Educational implications of this case study are suggested. The second part presents several pictorial images that can be used in classroom teaching of science for facilitation of hermeneutic discussion in science classes addressing the nature of scientific knowledge changed in the course of history.

  9. Lithium Depletion in the Beta Pictoris Moving Group

    NASA Astrophysics Data System (ADS)

    Yee, Jennifer C.; Jensen, E. L.; Reaser, B. E.

    2006-12-01

    We present a study of lithium depletion in twelve late-type pre-main-sequence stars in the coeval Beta Pictoris Moving Group (BPMG). The age of this group ( 12 Myr) is well constrained because all of the stars in the sample have Hipparcos distances. We have determined Li abundances for these K and M stars using equivalent width measurements of the 6707.8 Angstrom Li I line from new high-resolution, high-S/N echelle spectra, and we compare these abundances to models of pre-main-sequence Li depletion by Baraffe et al. (1998), D'Antona & Mazzitelli (1997, 1998), and Siess, Dufour, & Forestini (2000). Significantly more lithium depletion is observed in the sample than is predicted for a group of this age. In particular, the discrepancy between the predicted and the observed lithium abundances increases with decreasing effective temperature, suggesting a problem with theories describing pre-main-sequence lithium depletion. Our data indicate that M stars deplete lithium more rapidly than predicted, which could make M-type post-T-Tauri stars difficult to identify. In addition, we compare our results to the work of Song, Bessell, & Zuckerman (2002) on HIP 112312. In contrast to that work, we did not observe the lithium depletion boundary of the BPMG; none of the three M4.5 stars in the sample showed evidence of lithium (log N(Li) < -0.5), indicating a lithium depletion boundary later than M4.5, further underscoring the gap between age estimates from lithium depletion and those from theoretical evolutionary tracks. We gratefully acknowledge the support of the National Science Foundation through grant AST-0307830.

  10. Herschel detects oxygen in the β Pictoris debris disk

    NASA Astrophysics Data System (ADS)

    Brandeker, A.; Cataldi, G.; Olofsson, G.; Vandenbussche, B.; Acke, B.; Barlow, M. J.; Blommaert, J. A. D. L.; Cohen, M.; Dent, W. R. F.; Dominik, C.; Di Francesco, J.; Fridlund, M.; Gear, W. K.; Glauser, A. M.; Greaves, J. S.; Harvey, P. M.; Heras, A. M.; Hogerheijde, M. R.; Holland, W. S.; Huygen, R.; Ivison, R. J.; Leeks, S. J.; Lim, T. L.; Liseau, R.; Matthews, B. C.; Pantin, E.; Pilbratt, G. L.; Royer, P.; Sibthorpe, B.; Waelkens, C.; Walker, H. J.

    2016-06-01

    The young star β Pictoris is well known for its dusty debris disk produced through collisional grinding of planetesimals, kilometre-sized bodies in orbit around the star. In addition to dust, small amounts of gas are also known to orbit the star; this gas is likely the result of vaporisation of violently colliding dust grains. The disk is seen edge on and from previous absorption spectroscopy we know that the gas is very rich in carbon relative to other elements. The oxygen content has been more difficult to assess, however, with early estimates finding very little oxygen in the gas at a C/O ratio that is 20 × higher than the cosmic value. A C/O ratio that high is difficult to explain and would have far-reaching consequences for planet formation. Here we report on observations by the far-infrared space telescope Herschel, using PACS, of emission lines from ionised carbon and neutral oxygen. The detected emission from C+ is consistent withthat previously reported observed by the HIFI instrument on Herschel, while the emission from O is hard to explain without assuming a higher density region in the disk, perhaps in the shape of a clump or a dense torus required to sufficiently excite the O atoms. A possible scenario is that the C/O gas is produced by the same process responsible for the CO clump recently observed by the Atacama Large Millimeter/submillimeter Array in the disk and that the redistribution of the gas takes longer than previously assumed. A more detailed estimate of the C/O ratio and the mass of O will have to await better constraints on the C/O gas spatial distribution. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  11. Exposing the Gas Braking Mechanism of the β Pictoris Disk

    NASA Astrophysics Data System (ADS)

    Brandeker, Alexis

    2011-03-01

    Ever since the discovery of the edge-on circumstellar (CS) disk around β Pictoris, a standing question has been why the gas observed against the star in absorption is not rapidly expelled by the strong radiation pressure from the star. A solution to the puzzle has been suggested to be that the neutral elements that experience the radiation force also are rapidly ionized, and so are only able to accelerate to an average limiting velocity v ion. Once ionized, the elements are rapidly braked by C II, which is observed to be at least 20× overabundant in the disk with respect to other species. A prediction from this scenario is that different neutral elements should reach different v ion, depending on the ionization thresholds and strengths of driving line transitions. In particular, neutral Fe and Na are predicted to reach the radial velocities 0.5 and 3.3 km s-1, respectively, before being ionized. In this paper, we study the absorption profiles of Fe and Na from the CS gas disk around β Pic, as obtained by HARPS at the ESO 3.6 m telescope. We find that the Fe and Na velocity profiles are indeed shifted with respect to each other, confirming the model. The absence of an extended blue wing in the profile of Na, however, indicates that there must be some additional braking on the neutrals. We explore the possibility that the ion gas (dominated by C II) can brake the neutrals and conclude that about 2-5× more C than previously estimated is needed for the predicted line profile to be consistent with the observed one. Based on observations made with ESO Telescopes at the La Silla Observatory.

  12. On the age of the β Pictoris moving group

    NASA Astrophysics Data System (ADS)

    Mamajek, Eric E.; Bell, Cameron P. M.

    2014-12-01

    Binks & Jeffries and Malo et al. have recently reported Li depletion boundary (LDB) ages for the β Pictoris moving group (BPMG) which are twice as old as the oft-cited kinematic age of ˜12 Myr. In this study, we present (1) a new evaluation of the internal kinematics of the BPMG using the revised Hipparcos astrometry and best available published radial velocities, and assess whether a useful kinematic age can be derived, and (2) derive an isochronal age based on the placement of the A-, F-, and G-type stars in the colour-magnitude diagram (CMD). We explore the kinematics of the BPMG looking at velocity trends along Galactic axes, and conducting traceback analyses assuming linear trajectories, epicyclic orbit approximation, and orbit integration using a realistic gravitational potential. None of the methodologies yield a kinematic age with small uncertainties using modern velocity data. Expansion in the Galactic X and Y directions is significant only at the 1.7σ and 2.7σ levels, and together yields an overall kinematic age with a wide range (13-58 Myr; 95 per cent CL). The A-type members are all on the zero-age main sequence, suggestive of an age of >20 Myr, and the loci of the CMD positions for the late-F- and G-type pre-main-sequence BPMG members have a median isochronal age of 22 Myr (± 3 Myr statistical, ±1 Myr systematic) when considering four sets of modern theoretical isochrones. The results from recent LDB and isochronal age analyses are now in agreement with a median BPMG age of 23 ± 3 Myr (overall 1σ uncertainty, including ±2 Myr statistical and ±2 Myr systematic uncertainties).

  13. Wavelet processing techniques for digital mammography

    NASA Astrophysics Data System (ADS)

    Laine, Andrew F.; Song, Shuwu

    1992-09-01

    This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Similar to traditional coarse to fine matching strategies, the radiologist may first choose to look for coarse features (e.g., dominant mass) within low frequency levels of a wavelet transform and later examine finer features (e.g., microcalcifications) at higher frequency levels. In addition, features may be extracted by applying geometric constraints within each level of the transform. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet representations, enhanced by linear, exponential and constant weight functions through scale space. By improving the visualization of breast pathology we can improve the chances of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).

  14. Advantages and Disadvantages of Mammography Screening

    PubMed Central

    Heywang-Köbrunner, Sylvia H.; Hacker, Astrid; Sedlacek, Stefan

    2011-01-01

    Summary Mammography screening is the only method presently considered appropriate for mass screening of asymptomatic women. Its frequent use, however, warrants diligent analysis of potential side effects. Radiation risk is far below the natural yearly risk of breast cancer and should not be used as an argument against screening. False-positive calls lead to additional imaging or histopathological assessment, mainly percutaneous breast biopsy. These measures are tolerated and accepted fairly well. Their number is limited by strict quality assurance and constant training. Interval cancers represent a limitation of breast screening that should prompt further research for optimization. Evaluation of overdiagnosis is a highly debated topic in the literature. According to the probably most realistic available calculations, overdiagnosis is acceptable as it is compensated by the potential mortality reduction. Nonetheless, this potential side effect warrants optimal adjustment of therapy to the patient's individual risk. The mortality reduction seen in randomized studies was confirmed by results from national screening programs. A recent case referent study indicated that improvements in mortality reduction run parallel to improved mammographic techniques. Use of less aggressive therapies is another valuable effect of screening. Awareness of potential problems, strict quality assurance, and further research should help to further develop screening programs. PMID:21779225

  15. Digital mammography: tradeoffs between 50- and 100-micron pixel size

    NASA Astrophysics Data System (ADS)

    Freedman, Matthew T.; Steller Artz, Dorothy E.; Jafroudi, Hamid; Lo, Shih-Chung B.; Zuurbier, Rebecca A.; Katial, Raj; Hayes, Wendelin S.; Wu, Chris Y.; Lin, Jyh-Shyan; Steinman, Richard M.; Tohme, Walid G.; Mun, Seong K.

    1995-05-01

    Improvements in mammography equipment related to a decrease in pixel size of digital mammography detectors raise questions of the possible effects of these new detectors. Mathematical modeling suggested that the benefits of moving from 100 to 50 micron detectors were slight and might not justify the cost of these new units. Experiments comparing screen film mammography, a storage phosphor 100 micron digital detector, a 50 micron digital breast spot device, 100 micron film digitization and 50 micron film digitization suggests that object conspicuity should be better for digital compared to conventional systems, but that there seemed to be minimal advantage to going from 100 to 50 microns. The 50 micron pixel system appears to provide a slight advantage in object contrast and perhaps in shape definition, but did not allow smaller objects to be detected.

  16. Essays on Legal and Illegal Immigration.

    ERIC Educational Resources Information Center

    Pozo, Susan, Ed.

    Major issues of the debate that led to the passage of an immigration reform bill are discussed and analyzed in this collection of six papers that were delivered as public lectures at Western Michigan University during the 1984-85 academic year. The essays reflect a broad range of views on the effects of immigration on the United States economy and…

  17. Education, Training and Contexts: Studies and Essays.

    ERIC Educational Resources Information Center

    Lauglo, Jon

    This volume provides an overview of some of the outstanding features of the work of the Norwegian sociologist and comparative educationist, Jon Lauglo. After an introduction, "'It Ain't Necessarily So!': Theories and Observations in Jon Lauglo's World of Education and Training" (Se-Yung Lim and Klaus Schaack), essays and studies are presented in…

  18. Beyond the Five-Paragraph Essay

    ERIC Educational Resources Information Center

    Campbell, Kimberly Hill

    2014-01-01

    Although using the five-paragraph formula to teach essay writing is a ubiquitous practice--and many K-12 teachers defend it--Campbell argues that having students write according to this formula does more harm than good. The formula's tight structure stops the very critical thinking students need to do to strengthen their cognition and their…

  19. Art for Many Purposes: A Photo Essay.

    ERIC Educational Resources Information Center

    Corwin, Sylvia K.

    1985-01-01

    An interdisciplinary art and science program for talented inner-city 11th graders is described through a photo essay. Students are involved in activities such as painting outdoors, rendering instructional charts for use in science classes, illustrating seasonal calendars, gardening, identifying insects, and learning about weather forecasting. (RM)

  20. Toward More Substantively Meaningful Automated Essay Scoring

    ERIC Educational Resources Information Center

    Ben-Simon, Anat; Bennett, Randy Elliott

    2007-01-01

    This study evaluated a "substantively driven" method for scoring NAEP writing assessments automatically. The study used variations of an existing commercial program, e-rater[R], to compare the performance of three approaches to automated essay scoring: a "brute-empirical" approach in which variables are selected and weighted solely according to…

  1. An Analysis of Correctional Education GED Essays.

    ERIC Educational Resources Information Center

    Monahan, Michael P.; Schumacker, Randall E.

    Three judges rated General Educational Development (GED) student essays that had been written by nine incarcerated youths. If judge's ratings were not consistent, students would receive a biased average rating. Traditional classical measurement theory computes an intraclass reliability coefficient to determine if judges' ratings are reliable. In…

  2. Two Essays on the Learning Paradigm.

    ERIC Educational Resources Information Center

    Doud, Robert E.

    This document contains two essays, both of which discuss the ascendancy of the learning paradigm over the teaching paradigm. "Philosophy and the Learning Paradigm" reviews the effects of post-modernism on student learning with regard to loss of authority in the classroom, lack of academic standards in writing, and perceptions of professors as…

  3. Reconstructing Deweyan Pragmatism: A Review Essay

    ERIC Educational Resources Information Center

    Neubert, Stefan

    2009-01-01

    In this essay Stefan Neubert argues that John Dewey was a philosopher of reconstruction and that the best use we can make of him today is to reconstruct his work in and for our own contexts. Neubert distinguishes three necessary and equally important components of the overall project of reconstructing Deweyan pragmatism: first, to make strong and…

  4. Perspectives on the Community College: Essays.

    ERIC Educational Resources Information Center

    Lombardi, John; Cohen, Arthur M., Ed.

    The essays in this collection were written by John Lombardi during the 1970s while he was a resident scholar at the ERIC Clearinghouse for Junior Colleges. Following a foreword on Lombardi's life and work by a son and two daughters, John V., Mary Luciana, and Janice P. Lombardi, is an introduction by Arthur M. Cohen giving highlights of Lombardi's…

  5. An Overview of Automated Scoring of Essays

    ERIC Educational Resources Information Center

    Dikli, Semire

    2006-01-01

    Automated Essay Scoring (AES) is defined as the computer technology that evaluates and scores the written prose (Shermis & Barrera, 2002; Shermis & Burstein, 2003; Shermis, Raymat, & Barrera, 2003). AES systems are mainly used to overcome time, cost, reliability, and generalizability issues in writing assessment (Bereiter, 2003; Burstein,…

  6. Accountability of Colleges and Universities: An Essay.

    ERIC Educational Resources Information Center

    Graham, Patricia Albjerg; And Others

    This essay presents the results of a study of the means that colleges and universities should use to assure proper accountability within the institution in regard to teaching and learning. It discusses the basis of institutional accountability, public perceptions of accountability (or lack thereof), the role of governments and market forces, the…

  7. Essays on Neighborhood Transition and Housing Markets

    ERIC Educational Resources Information Center

    Casey, Marcus D.

    2009-01-01

    This dissertation presents new evidence on neighborhood transition and its impact on housing markets using a novel micro-level dataset on housing transactions. It focuses on three issues: the neighborhood effect, housing discrimination, and stable integration. The first essay examines the relationship between increased minority composition and…

  8. Review Essay: Inclusive Practices in Australia.

    ERIC Educational Resources Information Center

    Carroll, AnneMaree

    2002-01-01

    This essay reviews "Special Education: A Matter of Choice" (Josephine Jenkinson), a book that discusses the major issues and changes that have occurred in special education in the various states and territories of Australia over the past 30 years. It is concluded that the book is an extremely useful guide. (CR)

  9. The Vision of Sequoyah: A Bibliographic Essay.

    ERIC Educational Resources Information Center

    Wagner, Elaine

    In 1821, Sequoyah, a Cherokee Indian, presented to his tribal council a syllabary of the Cherokee language--an invention that enabled a previously illiterate people to read and write in their own language. This document includes a brief essay describing Sequoyah's life and accomplishment and a bibliography of further resources. Sequoyah was born…

  10. Degrees of Disenchantment: A Review Essay

    ERIC Educational Resources Information Center

    Brenneman, Mark; Margonis, Frank

    2012-01-01

    In this review essay, Mark Brenneman and Frank Margonis address three recent book-length contributions to the ongoing discussion around cosmopolitanism and educational thought: Mark Olssen's "Liberalism, Neoliberalism, Social Democracy: Thin Communitarian Perspectives on Political Philosophy and Education," Sharon Todd's "Toward an Imperfect…

  11. Three Essays on the Economics of Education

    ERIC Educational Resources Information Center

    Herrmann, Mariesa Ann

    2012-01-01

    This dissertation consists of essays on three inputs into the educational production function: curriculum, peers, and teachers. The chapters are linked by their focus on understanding the importance of these inputs for student achievement and by their exploitation of the exact timing of events (i.e., student mobility, receipt of special education…

  12. French Higher Education: A Cartoon Essay

    ERIC Educational Resources Information Center

    Hall, Matthew Henry

    2012-01-01

    In this cartoon essay, the author shares his experience from a travel to Paris to see the French higher education system. From his travel, he learned that in France, "degree" inflation may be an issue, but not grade inflation. On the flight home, the author reflects how French and American academics answer one question about the state of higher…

  13. The Nature of Automated Essay Scoring Feedback

    ERIC Educational Resources Information Center

    Dikli, Semire

    2010-01-01

    The purpose of this study is to explore the nature of feedback that English as a Second Language (ESL) students received on their writings either from an automated essay scoring (AES) system or from the teacher. The participants were 12 adult ESL students who were attending an intensive English center at a university in Florida. The drafts of the…

  14. Electronic Scoring of Essays: Does Topic Matter?

    ERIC Educational Resources Information Center

    James, Cindy L.

    2008-01-01

    The scoring of student essays by computer has generated much debate and subsequent research. The majority of the research thus far has focused on validating the automated scoring tools by comparing the electronic scores to human scores of writing or other measures of writing skills, and exploring the predictive validity of the automated scores.…

  15. Automated Essay Scoring: Psychometric Guidelines and Practices

    ERIC Educational Resources Information Center

    Ramineni, Chaitanya; Williamson, David M.

    2013-01-01

    In this paper, we provide an overview of psychometric procedures and guidelines Educational Testing Service (ETS) uses to evaluate automated essay scoring for operational use. We briefly describe the e-rater system, the procedures and criteria used to evaluate e-rater, implications for a range of potential uses of e-rater, and directions for…

  16. Audiotape Feedback for Essays in Distance Education.

    ERIC Educational Resources Information Center

    Kirschner, Paul A.; And Others

    1991-01-01

    Twelve students writing essays for a photochemistry course at the Open University of the Netherlands received either audiocasette or written feedback. Time spent in recording versus writing feedback differed minimally. Recorded feedback was considerably greater in amount. Students' final grades did not differ, but recorded feedback was more…

  17. Starting with "I": Personal Essays by Teenagers.

    ERIC Educational Resources Information Center

    Estepa, Andrea, Ed.; Kay, Philip, Ed.

    In personal essays, teenagers express their views on serious subjects like violence, racism, and teen parenting, and discuss common teen experiences like dating, getting a job, and starting college. This collection contains the following: (1) "Brotherly Love" (Jessica Vicuna); (2) "How To Survive Shopping with Mom" (Chris Kanarick); (3) "A…

  18. Social Responsibility in Librarianship: Essays on Equality.

    ERIC Educational Resources Information Center

    MacCann, Donnarae, Ed.

    In a culturally complex world, librarians can best work toward the equalization of library services if they understand their institutions in the light of cultural history. The six essays in this book highlight problems that affect unempowered populations, and address a variety of cultural problems and biases--problems that contribute to the…

  19. The Theory of the Novel: New Essays.

    ERIC Educational Resources Information Center

    Halperin, John, Ed.

    This collection, containing essays by contemporary critics, analyzes such aspects of the novel as structure, history, point of view, techniques, and its future. Included are "What is Exposition?" by Meir Sternberg; "Notes Toward a Comic Fiction" by Robert B. Martin; "The Aesthetics of the Supra-Novel" by Irving H. Buchen; "The Genre of 'Ulysses'"…

  20. Learning Dilemmas in Undergraduate Student Independent Essays

    ERIC Educational Resources Information Center

    Wendt, Maria; Åse, Cecilia

    2015-01-01

    Essay-writing is generally viewed as the primary learning activity to foster independence and analytical thinking. In this article, we show that independent research projects do not necessarily lead to critical thinking. University-level education on conducting independent projects can, in several respects, counteract enhanced analytical skills.…

  1. A Bibliographic Essay Pertaining to Navajo Indians.

    ERIC Educational Resources Information Center

    Harrison, Scott

    Introduced by a discussion of the fact that most of the works cited describe Navajos as they "used to be" and an admonition against the common practice of placing all Navajos, or all Indians, under one stereotype, this bibliographic essay traces the history of Navajo contact with the white man and emphasizes efforts at educational development. Six…

  2. Quantification of breast arterial calcification using full field digital mammography

    SciTech Connect

    Molloi, Sabee; Xu Tong; Ducote, Justin; Iribarren, Carlos

    2008-04-15

    Breast arterial calcification is commonly detected on some mammograms. Previous studies indicate that breast arterial calcification is evidence of general atherosclerotic vascular disease and it may be a useful marker of coronary artery disease. It can potentially be a useful tool for assessment of coronary artery disease in women since mammography is widely used as a screening tool for early detection of breast cancer. However, there are currently no available techniques for quantification of calcium mass using mammography. The purpose of this study was to determine whether it is possible to quantify breast arterial calcium mass using standard digital mammography. An anthropomorphic breast phantom along with a vessel calcification phantom was imaged using a full field digital mammography system. Densitometry was used to quantify calcium mass. A calcium calibration measurement was performed at each phantom thickness and beam energy. The known (K) and measured (M) calcium mass on 5 and 9 cm thickness phantoms were related by M=0.964K-0.288 mg (r=0.997 and SEE=0.878 mg) and M=1.004K+0.324 mg (r=0.994 and SEE=1.32 mg), respectively. The results indicate that accurate calcium mass measurements can be made without correction for scatter glare as long as careful calcium calibration is made for each breast thickness. The results also indicate that composition variations and differences of approximately 1 cm between calibration phantom and breast thickness introduce only minimal error in calcium measurement. The uncertainty in magnification is expected to cause up to 5% and 15% error in calcium mass for 5 and 9 cm breast thicknesses, respectively. In conclusion, a densitometry technique for quantification of breast arterial calcium mass was validated using standard full field digital mammography. The results demonstrated the feasibility and potential utility of the densitometry technique for accurate quantification of breast arterial calcium mass using standard digital

  3. Monte Carlo simulation studies of backscatter factors in mammography

    SciTech Connect

    Chan, H.P.; Doi, K.

    1981-04-01

    Experimentally determined backscatter factors in mammography can contain significant systematic errors due to the energy response, dimensions, and location of the dosimeter used. In this study, the Monte Carlo method was applied to simulate photon scattering in tissue-equivalent media and to determine backscatter factors without the interference of a detector. The physical processes of measuring backscatter factors with a lithium fluoride thermoluminescent dosimeter (TLD) and an ideal tissue-equivalent detector were also simulated. Computed results were compared with the true backscatter factors and with measured values reported by other investigators. It was found that the TLD method underestimated backscatter factors in mammography by as much as 10% at high energies.

  4. Convolutional neural networks for mammography mass lesion classification.

    PubMed

    Arevalo, John; Gonzalez, Fabio A; Ramos-Pollan, Raul; Oliveira, Jose L; Guevara Lopez, Miguel Angel

    2015-08-01

    Feature extraction is a fundamental step when mammography image analysis is addressed using learning based approaches. Traditionally, problem dependent handcrafted features are used to represent the content of images. An alternative approach successfully applied in other domains is the use of neural networks to automatically discover good features. This work presents an evaluation of convolutional neural networks to learn features for mammography mass lesions before feeding them to a classification stage. Experimental results showed that this approach is a suitable strategy outperforming the state-of-the-art representation from 79.9% to 86% in terms of area under the ROC curve. PMID:26736382

  5. Cost as a barrier to screening mammography among underserved women

    PubMed Central

    McAlearney, Ann Scheck; Reeves, Katherine W.; Tatum, Cathy; Paskett, Electra D.

    2015-01-01

    Background Breast cancer is a troublesome health problem, particularly among underserved and minority women. Early detection through screening mammography can reduce the impact of this disease, yet it remains underused. Objective We examined cost as a barrier to screening mammography and studied the accuracy of women’s perceptions of the cost of a mammogram among a rural, low-income, tri-racial (white, Native American and African American) population in need of a mammogram. Design We interviewed 897 women age 40 and older, asking about cost as a barrier to mammography and perceptions about the actual costs of a screening mammogram. Face-to-face interviews were conducted between 1998 and 2000 among women participating in a randomized, controlled study to evaluate a health education intervention to improve mammography screening rates in an underserved population. All data used in these analyses were from the baseline interviews. Results Cost acted as a barrier to screening mammography for a majority of the participants (53%). More than half of these women (52%), however, overestimated the cost of a screening mammogram, and overestimation of the cost was significantly related to mentioning cost as a barrier (OR 1.56, 95% CI 1.04–2.33). Higher estimates of out-of-pocket costs were associated with reporting cost as a barrier to mammography (OR 2.25, 95% CI 1.43–3.52 for $1–50 and OR 12.64, 95% CI 6.61–24.17 for > $50). Factors such as race, income and employment status were not related to reporting cost as a barrier to screening mammography. Conclusions Among a group of tri-racial, low-income, rural women who were in need of a mammogram, cost was a common barrier. Overestimating the cost, however, was significantly and positively associated with reporting cost as a barrier. Providing information about the actual cost women have to pay for mammograms may lessen the role of cost as a barrier to mammography screening, especially for underserved women, potentially

  6. Mammography use and mode of detection among breast cancer patients in Estonia.

    PubMed

    Innos, Kaire; Valvere, Vahur; Padrik, Peeter; Eelma, Evelyn; Kütner, Riina; Lehtsaar, Jaak; Tekkel, Mare

    2016-01-01

    The aim of this study was to examine past mammography use and mode of detection among breast cancer (BC) patients in Estonia, a country that has low screening coverage and high BC mortality. Women newly diagnosed with primary BC in Estonia in 2008-2010 were interviewed. Determinants of past mammography use and the detection of BC by mammography were studied using multivariate logistic regression. Among 977 participants, almost half reported no mammograms prior to the detection of BC. Overall, 22% of the cases were detected by mammography (16% by screening mammography). Detection by mammography was strongly related to age, past mammography use, and obesity. Among cases detected by mammography, 10% were stage III/IV at diagnosis (32% among cases detected by other modes). This study showed low mammography utilization and high rate of self-detection of BC in Estonia. Increased detection by mammography would help diagnose the disease at an earlier stage and consequently avoid premature BC deaths. Efforts should be undertaken to increase participation in screening and improve the availability of mammography among older and high-risk women. The results are likely to be relevant for other countries and population groups with low screening coverage. PMID:26327255

  7. Comparison of Image Quality Criteria between Digital Storage Phosphor Plate in Mammography and Full-Field Digital Mammography in the Detection of Breast Cancer

    PubMed Central

    Thevi Rajendran, Pushpa; Krishnapillai, Vijayalakshmi; Tamanang, Sulaiman; Kumari Chelliah, Kanaga

    2012-01-01

    Background: Digital mammography is slowly replacing screen film mammography. In digital mammography, 2 methods are available in acquiring images: digital storage phosphor plate and full-field digital mammography. The aim of this study was to compare the image quality acquired from the 2 methods of digital mammography in the detection of breast cancer. Methods: The study took place at the National Cancer Society, Kuala Lumpur, and followed 150 asymptomatic women for the duration of 1 year. Participating women gave informed consent and were exposed to 4 views from each system. Two radiologists independently evaluated the printed images based on the image quality criteria in mammography. McNemar’s test was used to compare the image quality criteria between the systems. Results: The agreement between the radiologists for the digital storage phosphor plate was к = 0.551 and for full-field digital mammography was к = 0.523. Full-field digital mammography was significantly better compared with the digital storage phosphor plate in right and left mediolateral oblique views (P < 0.05) in the detection of microcalcifications, which are early signs of breast cancer. However, both systems were comparable in all other aspects of image quality. Conclusion: Digital mammography is a useful screening tool for the detection of early breast cancer and ensures better prognosis and quality of life. PMID:22977375

  8. The Interactive Effects of Color and Cognitive Style on a Pictorial Recognition Memory Task.

    ERIC Educational Resources Information Center

    Wieckowski, Theodora J.

    A study was conducted to determine if there was a relationship between the cognitive styles of learners and their ability to correctly identify previously seen pictorial materials presented in color or black and white. Fifty-three third and fourth grade students from the Pittsburgh Public School System served as subjects for the study. Testing…

  9. Use of Pictorial Evaluations to Measure Knowledge Gained by Hispanic Landscape Workers Receiving Safety Training

    ERIC Educational Resources Information Center

    Bauske, Ellen M.; Fuhrman, Nicholas E.; Martinez-Espinoza, Alfredo D.; Orellana, Rolando

    2013-01-01

    Landscape work is dangerous. In the Southeast, Hispanic workers predominate in landscape industries. The incidence of functional illiteracy in this group of workers is high. A pictorial knowledge-based evaluation instrument was developed to measure the effectiveness of the trainings. No reading skills were required to take the evaluation. The…

  10. Veridical and False Pictorial Memory in Individuals with and without Mental Retardation

    ERIC Educational Resources Information Center

    Carlin, Michael T.; Toglia, Michael P.; Wakeford, Yvonne; Jakway, Allison; Sullivan, Kate; Hasel, Lisa

    2008-01-01

    Veridical and false pictorial recognition were assessed in individuals with mental retardation; groups were matched for MA and CA. Pictures were viewed in either a generative or static format at acquisition. The individuals with mental retardation and those in the MA-matched group had higher rates of false memories for critical items and lower hit…

  11. Cognitive Load in Percentage Change Problems: Unitary, Pictorial, and Equation Approaches to Instruction

    ERIC Educational Resources Information Center

    Ngu, Bing Hiong; Yeung, Alexander Seeshing; Tobias, Stephen

    2014-01-01

    Eighth grade students in Australia (N = 60) participated in an experiment on learning how to solve percentage change problems in a regular classroom in three conditions: unitary, pictorial, and equation approaches. The procedure involved a pre-test, an acquisition phase, and a post-test. The main goal was to test the relative merits of the three…

  12. 14. Photocopy of drawing (from: Lossing, Benson, J. Pictorial FieldBook ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of drawing (from: Lossing, Benson, J. Pictorial Field-Book of the Revolution. (New York: Harper & Brothers, 1855), Vol. 2, p. 180.) ca. 1855, delineator unknown WEST SIDE AND SOUTH FRONT - John Chad House, State Route 100, U.S. Route 1 vicinity, Chadds Ford, Delaware County, PA

  13. Following the Wrong Footsteps: Fixation Effects of Pictorial Examples in a Design Problem-Solving Task

    ERIC Educational Resources Information Center

    Chrysikou, Evangelia G.; Weisberg, Robert W.

    2005-01-01

    Two experiments examined possible negative transfer in nonexperts from the use of pictorial examples in a laboratory design problem-solving situation. In Experiment 1, 89 participants were instructed to "think aloud" and were assigned to 1 of 3 conditions: (a) control (standard instructions), (b) fixation (inclusion of a problematic example,…

  14. Earth: Man's Home. A Beginning Geography Unit. Pupil Workbook and Pictorial Test and Teacher Manual.

    ERIC Educational Resources Information Center

    Imperatore, William

    This conceptual unit in geography at the kindergarten level consists of a student Workbook and Pictorial Test, and a Teacher Manual. The objective of the unit is to develop the concept labeled "habitat", or the idea that the earth is man's home. Teaching strategies include questioning techniques, an analysis of pictures, classroom discussion,…

  15. A Novel Pictorial Approach to Teaching Molecular Motions in Polyatomic Molecules.

    ERIC Educational Resources Information Center

    Verkade, John G.

    1987-01-01

    Describes a procedure for teaching the "generator orbital" (GO) approach of molecular orbital bonding in polyatomic molecules. Explains how the GO can be utilized with students in generating the vibrational, rotational, and translational modes of molecules in a completely pictorial manner. (ML)

  16. Pictorial Aids for Learning by Doing in a Multimedia Geology Simulation Game.

    ERIC Educational Resources Information Center

    Mayer, Richard E.; Mautone, Patricia; Prothero, William

    2002-01-01

    The task was to survey an area of a planet's surface to identify the presence of various geological features such as a trench, ridge, or basin. Students who received prior pictorial representations of features performed more accurately than students who did not, but there was no significant effect for including verbal statements about strategies…

  17. The Effects of Varying Pictorial Detail and Presentation Strategy on Concept Formation.

    ERIC Educational Resources Information Center

    Gorman, Don A.

    The purpose of this study is to determine the effects of varying pictorial detail and presentation strategy on learners of varying grade levels in a visually transmitted concept formation task. Specifically, line drawings containing only relevant details and halftones containing relevant and irrelevant detail were presented successively and…

  18. Near, yet so Far: The Effect of Pictorial Cues on Spatial Attention

    ERIC Educational Resources Information Center

    Nicholls, Michael E. R.; Forte, Jason D.; Loetscher, Tobias; Orr, Catherine A.; Yates, Mark J.; Bradshaw, John L.

    2011-01-01

    Distinct cognitive and neural mechanisms underlie perception and action in near (within-reach) and far (outside-reach) space. Objects in far space can be brought into the brain's near-space through tool-use. We determined whether a near object can be pushed into far space by changing the pictorial context in which it occurs. Participants (n = 372)…

  19. The Didactic Organization of Pictorial Reality in the New Language Teaching Media.

    ERIC Educational Resources Information Center

    Fleming, Gerald; And Others

    1967-01-01

    High on the list of today's educational priorities is the effective programing of pictorial stimuli as language teaching tools. The value of any image depends on its content of information, and essential for clear comprehension of any picture are the principles of causality, parallelism, and contrast or negative comparison. Both artist and teacher…

  20. Interaction of Learner Characteristics with Pictorial Adjuncts in Learning from Science Text.

    ERIC Educational Resources Information Center

    Koran, Mary Lou; Koran, John J., Jr.

    1980-01-01

    Investigates whether placement of pictorial adjuncts before or after related textual material enhances instructional effectiveness for learners of varying ability. Junior high students (N=84) were randomly assigned to one or three treatments in which a diagram of the hydrologic cycle was inserted before, after, or omitted from the text. (CS)

  1. Examining Pictorial Models and Virtual Manipulatives for Third-Grade Fraction Instruction

    ERIC Educational Resources Information Center

    Moyer-Packenham, Patricia S.; Ulmer, Lori A.; Anderson, Katie L.

    2012-01-01

    The purpose of this study was to examine pictorial representations, whether in static or dynamic modalities, and their impact on student learning in a classroom with low-achieving students. The investigation emerged from a classroom teacher's action research project. During a three-week fraction unit, nineteen third-grade low-achieving students…

  2. Cognitive Differences in Pictorial Reasoning between High-Functioning Autism and Asperger's Syndrome

    ERIC Educational Resources Information Center

    Sahyoun, Cherif P.; Soulieres, Isabelle; Belliveau, John W.; Mottron, Laurent; Mody, Maria

    2009-01-01

    We investigated linguistic and visuospatial processing during pictorial reasoning in high-functioning autism (HFA), Asperger's syndrome (ASP), and age and IQ-matched typically developing participants (CTRL), using three conditions designed to differentially engage linguistic mediation or visuospatial processing (visuospatial, V; semantic, S;…

  3. Recognition of Pictorial Material As A Function of Experiential Deprivation and Age.

    ERIC Educational Resources Information Center

    Misra, Girishwar; Shukla, Aradhana

    1984-01-01

    Investigated relative effects of chronological age and experiential deprivation upon pictorial recognition. Four age levels (ages four to five, five to six, six to seven, and seven to eight years) and two levels of deprivation were manipulated. The 50 subjects in each factorial cell performed tasks individually. (Author/RH)

  4. Children's Independent Exploration of a Natural Phenomenon by Using a Pictorial Computer-Based Simulation.

    ERIC Educational Resources Information Center

    Kangassalo, Marjatta.

    1994-01-01

    Examines children's understanding of the variation of sunlight and heat of the sun as experienced on the earth related to the positions of the earth and the sun in space, while using a pictorial computer simulation of the phenomenon. Suggests that, through the exploration of the program, children seemed to follow a correctly directed conceptual…

  5. Pictorial Apprenticeship Program Handbook: A Project Planning Strategy for Preliterate Communities. Women in Development.

    ERIC Educational Resources Information Center

    Bloom, Evan; Reed, Sue

    Intended for community development professionals and volunteers who work with preliterate communities, this illustrated handbook accompanies a library of visual aids that allow rural people to formulate their own projects. (The curriculum, called Pictorial Apprenticeship, transfers the process of project design into visual forms that literate and…

  6. Pedagogy and Pictorial Evidence: Interpreting Post-Reformation English Prints in Context

    ERIC Educational Resources Information Center

    Ormond, Barbara

    2011-01-01

    This article discusses the increasing emphasis on using pictorial sources in teaching, learning and assessment in history and asserts that pedagogies for interpreting visual imagery need to be purposefully aligned in relation to the particular media or production contexts under study. Expecting students to be able to glean meaning from images…

  7. Simulating Observations of the beta-Pictoris System with the JWST/MIRI Instrument

    NASA Astrophysics Data System (ADS)

    Lagage, P.-O.; Boccaletti, A.; Baudoz, P.; Bouchet, P.

    2014-09-01

    The MIRI instrument of the James Webb Space Telescope (JWST), scheduled to be launched in 2018, offers the potentiality to address the lack of observations of the beta Pictoris b exoplanet beyond 5 microns. Thanks to the large size of the JWST (diameter of 6.5m), MIRI will provide an unprecedented sensitivity. The angular resolution between the beta-Pictoris star and its planet (about 300-400 mas) is at the limit of what can be achieved at 10 microns with a 6.5 m telescope. Thanks to its four quadrant phase mask coronagraphic mode, MIRI observations at low inner angles (down to lambda/D) will be possible at three wavelengths: 10.65, 11.4 and 15.5 microns (Boccaletti et al. 2005, 2014). Detailed simulations are needed to assess the question of the detectability of the beta-Pictoris b planet with MIRI and of the photometric precision achievable. The first results of such simulations will be presented. Observations of the beta-Pictoris disk with the Low Resolution Spectroscopic (LRS) mode of MIRI, as well as with the MIRI Integral Field Unit Medium Resolution Spectrometer (MRS) will also be discussed.

  8. The Effectiveness of Electronic Text and Pictorial Graphic Organizers to Improve Comprehension Related to Functional Skills

    ERIC Educational Resources Information Center

    Douglas, Karen H.; Ayres, Kevin M.; Langone, John; Bramlett, Virginia Bell

    2011-01-01

    This study evaluated the effects of a computer-based instructional program to assist three students with mild to moderate intellectual disabilities in using pictorial graphic organizers as aids for increasing comprehension of electronic text-based recipes. Student comprehension of recipes was measured by their ability to verbally retell recipe…

  9. On the Power of Fine Arts Pictorial Imagery in Science Education

    ERIC Educational Resources Information Center

    Galili, Igal

    2013-01-01

    The paper describes and illustrates the potential of using pictorial artistic images in supporting teaching scientific concepts and the nature of science. In the first part, the case of Giotto's fresco of stigmatization of St. Francis is described within the interpretation of relationship between the figures as between an object and its…

  10. The Pictorial Fire Stroop: A Measure of Processing Bias for Fire-Related Stimuli

    ERIC Educational Resources Information Center

    Gallagher-Duffy, Joanne; MacKay, Sherri; Duffy, Jim; Sullivan-Thomas, Meara; Peterson-Badali, Michele

    2009-01-01

    Fire interest is a risk factor for firesetting. This study tested whether a fire-specific emotional Stroop task can effectively measure an information-processing bias for fire-related stimuli. Clinic-referred and nonreferred adolescents (aged 13-16 years) completed a pictorial "Fire Stroop," as well as a self-report fire interest questionnaire and…

  11. Do Adults with Mental Retardation Show Pictorial Superiority Effects in Recall and Recognition?

    ERIC Educational Resources Information Center

    Cherry, Katie E.; Applegate, Heather; Reese, Celinda M.

    2002-01-01

    A study examined memory for pictures and words in 16 adults with mental retardation and 24 controls. Pictorial superiority effects occurred in free recall and recognition for both intelligence-level groups. Correlational analyses indicated working memory span was primarily related to recall performance, irrespective of stimulus format. (Contains…

  12. Memory for Pictures, Words, and Spatial Location in Older Adults: Evidence for Pictorial Superiority.

    ERIC Educational Resources Information Center

    Park, Denise Cortis; And Others

    1983-01-01

    Tested recognition memory for items and spatial location by varying picture and word stimuli across four slide quadrants. Results showed a pictorial superiority effect for item recognition and a greater ability to remember the spatial location of pictures versus words for both old and young adults (N=95). (WAS)

  13. The Effects of Pictorial Complexity and Cognitive Style on Visual Recall Memory.

    ERIC Educational Resources Information Center

    Jesky, Romaine R.; Berry, Louis H.

    The effect of the interaction between cognitive style differences (field dependence/field independence) and various degrees of visual complexity on pictorial recall memory was explored using three sets of visuals in three different formats--line drawing, black and white, and color. The subjects were 86 undergraduate students enrolled in two core…

  14. Essaying the essay: nursing scholarship and the hegemony of the laboratory.

    PubMed

    Gardner, Lyn; Rolfe, Gary

    2013-01-01

    It might appear odd or even perverse to be arguing for the essay as a vehicle for academic thought and writing, particularly given the current emphasis on scientific research and evidence-based practice. In fact, the scholarly essay has virtually ceased to exist as an academic form in practice disciplines such as nursing, excluded by what we will identify and refer to as the hegemony of the laboratory. In a practical as well as an intellectual attempt to reinstate it, this paper is structured in the form of two consecutive short essays. In the first, we identify the character, features and purpose of the scholarly essay and examine its demise as an academic form. In the second, we explore some possible reasons why the essay never became fully accepted as an academic form in nursing. We suggest that the essay is thematically eclectic and stylistically promiscuous, drawing from a broad range of cultural, disciplinary and academic reference points. As such, it presents a challenge to the dominant technical rational approach to academic nursing in both its form and its content, particularly in its disregard for the rigidly imposed genres and structures increasingly demanded by academic nursing journals. PMID:22079481

  15. The Primal Screen: Essays on Film and Related Subjects.

    ERIC Educational Resources Information Center

    Sarris, Andrew

    This book is a collection of essays by the author on film criticism. An auteurist and historical approach is taken to the primarily American films discussed. The essays are organized by basic theme: "Critical Credos and Causes,""Personal Styles,""Genres,""Politics,""Odes and Obits," and "Arts and Letters." Each essay centers either on an important…

  16. Lincoln Era Essay Contest: Seventh Annual Winners, 1988.

    ERIC Educational Resources Information Center

    Cagle, William, Ed.

    The seventh annual Lincoln Era Essay Contest's theme was "Lincoln and the Elections of 1860 and 1864." The contest was open to students in grades 6 through 12 throughout the state of Indiana. This booklet includes all the winning essays. The junior high/middle school essays include: "Abraham Lincoln Journals for the 1860 and 1864 Elections" (C.…

  17. Twenty Years In: An Essay in Two Parts

    ERIC Educational Resources Information Center

    Heilker, Paul

    2006-01-01

    Part I of this essay traces the evolution of my understanding of the exploratory essay as a discursive form and a genre for teaching writing. Part II explores my motivations for advocating a polarized definition of the essay and then concludes with a call to expand the purview of composition beyond first-year courses.

  18. Using Literature to Teach the Non-Literary Research Essay.

    ERIC Educational Resources Information Center

    Wess, Robert C.

    The controversial uses of the generic research essay and literature in the composition class fuse together as one issue when one considers the use of literature to teach the research essay in the freshman composition class. This pedagogical approach requires that students read a novel, selected by the teacher, write several essays about it, and…

  19. Conceptualizing Essay Tests' Reliability and Validity: From Research to Theory

    ERIC Educational Resources Information Center

    Badjadi, Nour El Imane

    2013-01-01

    The current paper on writing assessment surveys the literature on the reliability and validity of essay tests. The paper aims to examine the two concepts in relationship with essay testing as well as to provide a snapshot of the current understandings of the reliability and validity of essay tests as drawn in recent research studies. Bearing in…

  20. The Essay Scoring and Scorer Reliability in TOEFL CBT.

    ERIC Educational Resources Information Center

    Lee, Yong-Won

    An essay test is now an integral part of the computer based Test of English as a Foreign Language (TOEFL-CBT). This paper provides a brief overview of the current TOEFL-CBT essay test, describes the operational procedures for essay scoring, including the Online Scoring Network (OSN) of the Educational Testing Service (ETS), and discusses major…

  1. Text Structure of Korean Speakers' Argumentative Essays in English.

    ERIC Educational Resources Information Center

    Choi, Yeon Hee

    1988-01-01

    Examines text structure of argumentative writing in English by Korean speakers as compared with native speakers'(NS) writing in Korean and NS writing in English. Interactive text analysis showed English essays had a clear structural pattern that the Korean essays lacked. Sample essays and questionnaires are included in Appendix. (Author/LMO)

  2. Comparison of Dimension Reduction Methods for Automated Essay Grading

    ERIC Educational Resources Information Center

    Kakkonen, Tuomo; Myller, Niko; Sutinen, Erkki; Timonen, Jari

    2008-01-01

    Automatic Essay Assessor (AEA) is a system that utilizes information retrieval techniques such as Latent Semantic Analysis (LSA), Probabilistic Latent Semantic Analysis (PLSA), and Latent Dirichlet Allocation (LDA) for automatic essay grading. The system uses learning materials and relatively few teacher-graded essays for calibrating the scoring…

  3. Rooted in the Land: Essays on Community and Place.

    ERIC Educational Resources Information Center

    Vitek, William, Ed.; Jackson, Wes, Ed.

    This collection of 31 essays examines the idea of community rooted in a particular place, usually a small town or rural place. Many essays comment on the role of education in promoting the transient materialistic lifestyle or suggest ways in which education could foster place attachment and community building. Essays specifically focused on…

  4. The Computer Moves into Essay Grading: Updating the Ancient Test.

    ERIC Educational Resources Information Center

    Page, Ellis; Petersen, Nancy S.

    1995-01-01

    Computers may someday replace teachers at essay grading. In recent research, a blind test has demonstrated that a computer can simulate the judgment of a group of human judges on a brand-new set of essays. Moreover, the PEG (Project Essay Grade) program can do a better (and more cost-effective) job than the usual two human readers while providing…

  5. VLT imaging of the β Pictoris gas disk

    NASA Astrophysics Data System (ADS)

    Nilsson, R.; Brandeker, A.; Olofsson, G.; Fathi, K.; Thébault, Ph.; Liseau, R.

    2012-08-01

    Context. Circumstellar debris disks older than a few Myr should be largely devoid of primordial gas remaining from the protoplanetary disk phase. Tracing the origin of observed atomic gas in Keplerian rotation in the edge-on debris disk surrounding the ~12 Myr old star β Pictoris requires more detailed information about its spatial distribution than has previously been acquired by limited slit spectroscopy. Especially indications of asymmetries and presence of Ca ii gas at high disk latitudes call for additional investigation to exclude or confirm its connection to observed dust structures or suggested cometary bodies on inclined eccentric orbits. Aims: We set out to recover a complete image of the Fe i and Ca ii gas emission around β Pic by spatially resolved, high-resolution spectroscopic observations to better understand the morphology and origin of the gaseous disk component. Methods: The multiple fiber facility FLAMES/GIRAFFE at the Very Large Telescope (VLT), with the large integral-field-unit ARGUS, was used to obtain spatially resolved optical spectra (from 385.9 to 404.8 nm) in four regions covering the northeast and southwest side of the disk. Emission lines from Fe i (at 386.0 nm) and Ca ii (at 393.4 and 396.8 nm) were mapped and could be used to fit a parametric function for the disk gas distribution, using a gas-ionisation code for gas-poor debris disks. Results: Both Fe i and Ca ii emission are clearly detected, with the former dominating along the disk midplane, and the latter revealing vertically more extended gas. The surface intensity of the Fe i emission is lower but more extended in the northeast (reaching the 210 AU limit of our observations) than in the southwest, while Ca ii shows the opposite asymmetry. The modelled Fe gas disk profile shows a linear increase in scale height with radius, and a vertical profile that suggests dynamical interaction with the dust. We also qualitatively demonstrate that the Ca ii emission profile can be

  6. Physical and orbital properties of β Pictoris b

    NASA Astrophysics Data System (ADS)

    Bonnefoy, M.; Marleau, G.-D.; Galicher, R.; Beust, H.; Lagrange, A.-M.; Baudino, J.-L.; Chauvin, G.; Borgniet, S.; Meunier, N.; Rameau, J.; Boccaletti, A.; Cumming, A.; Helling, C.; Homeier, D.; Allard, F.; Delorme, P.

    2014-07-01

    The intermediate-mass star β Pictoris is known to be surrounded by a structured edge-on debris disk within which a gas giant planet was discovered orbiting at 8-10 AU. The physical properties of β Pic b were previously inferred from broad- and narrow-band 0.9-4.8 μm photometry. We used commissioning data of the Gemini Planet Imager (GPI) to obtain new astrometry and a low-resolution (R ~ 35-39) J-band (1.12-1.35 μm) spectrum of the planet. We find that the planet has passed the quadrature. We constrain its semi-major axis to ≤10 AU (90% prob.) with a peak at 8.9+0.4-0.6 AU. The joint fit of the planet astrometry and the most recent radial velocity measurements of the star yields a planet dynamical mass lower than 20 MJup (≥96% prob.). The extracted spectrum of β Pic b is similar to those of young L1-1.5+1 dwarfs. We used the spectral type estimate to revise the planet luminosity to log (L/L⊙) = -3.90 ± 0.07. The 0.9-4.8 μm photometry and spectrum are reproduced for Teff = 1650 ± 150 K and a log g ≤ 4.7 dex by 12 grids of PHOENIX-based and LESIA atmospheric models. For the most recent system age estimate (21 ± 4 Myr), the bolometric luminosity and the constraints on the dynamical mass of β Pic b are only reproduced by warm- and hot-start tracks with initial entropies Si> 10.5 kB/baryon. These initial conditions may result from an inefficient accretion shock and/or a planetesimal density at formation higher than in the classical core-accretion model. Considering a younger age for the system or a conservative formation time for β Pic b does not change these conclusions. Appendices are available in electronic form at http://www.aanda.org

  7. Disclosing Harmful Mammography Errors to Patients1

    PubMed Central

    Gallagher, Thomas H.; Cook, Andrea J.; Brenner, R. James; Carney, Patricia A.; Miglioretti, Diana L.; Geller, Berta M.; Kerlikowske, Karla; Onega, Tracy L.; Rosenberg, Robert D.; Yankaskas, Bonnie C.; Lehman, Constance D.; Elmore, Joann G.

    2009-01-01

    Purpose: To assess radiologists’ attitudes about disclosing errors to patients by using a survey with a vignette involving an error interpreting a patient's mammogram, leading to a delayed cancer diagnosis. Materials and Methods: We conducted an institutional review board–approved survey of 364 radiologists at seven geographically distinct Breast Cancer Surveillance Consortium sites that interpreted mammograms from 2005 to 2006. Radiologists received a vignette in which comparison screening mammograms were placed in the wrong order, leading a radiologist to conclude calcifications were decreasing in number when they were actually increasing, delaying a cancer diagnosis. Radiologists were asked (a) how likely they would be to disclose this error, (b) what information they would share, and (c) their malpractice attitudes and experiences. Results: Two hundred forty-three (67%) of 364 radiologists responded to the disclosure vignette questions. Radiologists’ responses to whether they would disclose the error included “definitely not” (9%), “only if asked by the patient” (51%), “probably” (26%), and “definitely” (14%). Regarding information they would disclose, 24% would “not say anything further to the patient,” 31% would tell the patient that “the calcifications are larger and are now suspicious for cancer,” 30% would state “the calcifications may have increased on your last mammogram, but their appearance was not as worrisome as it is now,” and 15% would tell the patient “an error occurred during the interpretation of your last mammogram, and the calcifications had actually increased in number, not decreased.” Radiologists’ malpractice experiences were not consistently associated with their disclosure responses. Conclusion: Many radiologists report reluctance to disclose a hypothetical mammography error that delayed a cancer diagnosis. Strategies should be developed to increase radiologists’ comfort communicating with

  8. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  9. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  10. [How would plain packaging and pictorial warning impact on smoking reduction, cessation and initiation?].

    PubMed

    Mannocci, Alice; Colamesta, Vittoria; Mipatrini, Daniele; Boccia, Antonio; Terzano, Claudio; La Torre, Giuseppe

    2013-01-01

    The European Commission has proposed a review of the directive on tobacco products on labeling and packaging of tobacco products by introducing warning text with pictorial warning that occupies 75% of the cigarette packages. The aim of the survey was to assess the impact of plain packaging and pictorial warning in smoking reduction, cessation and initiation among a sample of adult. The cross-sectional study was conducted in Rome between September and November 2012. The questionnaires administered were 227, with a response rate of 82.4%. 35.8% (No. 67) of the respondents considered the image of the gangrene the most effective in communicating smoking-related damages, followed by the image on lung cancer (No. 60; 32.1%). Distinguishing between smokers and non-smokers (both former and never smokers), the picture on lung cancer was the most effective for smokers (No. 22; 38.6%); if cigarette packages have pictorial warnings like the ones shown, more than half (No. 33; 57.9%) of smokers would change brand; 66.7% (No. 38) of them would feel uncomfortable in showing the package. Comparing the 3 packagings, classic packaging, plain packaging with textual warning, and plain packaging with both textual and pictorial warning, the majority of people declared that the third is the most effective in preventing smoking initiation (No. 169; 90.9%), in motivating to quit (No. 158; 84.9%), and in changing smoking habits (No. 149; 80.5%). The survey, although its small sample size and being not representative of all strata of Italian population, shows that the plain packaging with pictorial warning is the most convincing in the three outcomes considered. PMID:24548838

  11. A Topic-Independent Method for Scoring Student Essay Content

    NASA Astrophysics Data System (ADS)

    Nagata, Ryo; Kakegawa, Jun-Ichi; Yabuta, Yukiko

    This paper proposes a topic-independent method for automatically scoring essay content. Unlike conventional topic-dependent methods, it predicts the human-assigned score of a given essay without training essays written to the same topic as the target essay. To achieve this, this paper introduces a new measure called MIDF that measures how important and relevant a word is in a given essay. The proposed method predicts the score relying on the distribution of MIDF. Surprisingly, experiments show that the proposed method achieves an accuracy of 0.848 and performs as well as or even better than conventional topic-dependent methods.

  12. Implications of Overdiagnosis: Impact on Screening Mammography Practices

    PubMed Central

    Morris, Elizabeth; Feig, Stephen A.; Drexler, Madeline

    2015-01-01

    Abstract This review article explores the issue of overdiagnosis in screening mammography. Overdiagnosis is the screen detection of a breast cancer, histologically confirmed, that might not otherwise become clinically apparent during the lifetime of the patient. While screening mammography is an imperfect tool, it remains the best tool we have to diagnose breast cancer early, before a patient is symptomatic and at a time when chances of survival and options for treatment are most favorable. In 2015, an estimated 231,840 new cases of breast cancer (excluding ductal carcinoma in situ) will be diagnosed in the United States, and some 40,290 women will die. Despite these data, screening mammography for women ages 40–69 has contributed to a substantial reduction in breast cancer mortality, and organized screening programs have led to a shift from late-stage diagnosis to early-stage detection. Current estimates of overdiagnosis in screening mammography vary widely, from 0% to upwards of 30% of diagnosed cancers. This range reflects the fact that measuring overdiagnosis is not a straightforward calculation, but usually one based on different sets of assumptions and often biased by methodological flaws. The recent development of tomosynthesis, which creates high-resolution, three-dimensional images, has increased breast cancer detection while reducing false recalls. Because the greatest harm of overdiagnosis is overtreatment, the key goal should not be less diagnosis but better treatment decision tools. (Population Health Management 2015;18:S3–S11) PMID:26414384

  13. An equivalent relative utility metric for evaluating screening mammography

    PubMed Central

    Abbey, Craig K.; Eckstein, Miguel P.; Boone, John M.

    2009-01-01

    Comparative studies of performance in screening mammography are often ambiguous. A new method will frequently show a higher sensitivity or detection rate than an existing standard with a concomitant increase in false positives or recalls. We propose an equivalent relative utility (ERU) metric based on signal detection theory to quantify screening performance in such comparisons. The metric is defined as the relative utility, as defined in classical signal detection theory, needed to make two systems equivalent. ERU avoids the problem of requiring a predefined putative relative utility, which has limited application of utility theory in ROC analysis. The metric can be readily estimated from recall and detection rates commonly reported in comparative clinical studies. An important practical advantage of ERU is that in prevalence matched populations, the measure can be estimated without an independent estimate of disease prevalence. Thus estimating ERU does not require a study with long term follow up to find cases of missed disease. The approach is applicable to any comparative screening study that reports results in terms of recall and detection rates, although we focus exclusively on screening mammography in this work. We derive the ERU from the definition of utility given in classical treatments of signal detection theory. We also investigate reasonable values of relative utility in screening mammography for use in interpreting ERU using data from a large clinical study. As examples of application of ERU, we re-analyze two recently published reports using recall and detection rates in screening mammography. PMID:19706880

  14. Study of signal-to-noise ratio in digital mammography

    NASA Astrophysics Data System (ADS)

    Kato, Yuri; Fujita, Naotoshi; Kodera, Yoshie

    2009-02-01

    Mammography techniques have recently advanced from those using analog systems (the screen-film system) to those using digital systems; for example, computed radiography (CR) and flat-panel detectors (FPDs) are nowadays used in mammography. Further, phase contrast mammography (PCM)-a digital technique by which images with a magnification of 1.75× can be obtained-is now available in the market. We studied the effect of the air gap in PCM and evaluated the effectiveness of an antiscatter x-ray grid in conventional mammography (CM) by measuring the scatter fraction ratio (SFR) and relative signal-to-noise ratio (rSNR) and comparing them between PCM and the digital CM. The results indicated that the SFRs for the CM images obtained with a grid were the lowest and that these ratios were almost the same as those for the PCM images. In contrast, the rSNRs for the PCM images were the highest, which means that the scattering of x-rays was sufficiently reduced by the air gap without the loss of primary x-rays.

  15. Evaluation of image quality in computed radiography based mammography systems

    NASA Astrophysics Data System (ADS)

    Singh, Abhinav; Bhwaria, Vipin; Valentino, Daniel J.

    2011-03-01

    Mammography is the most widely accepted procedure for the early detection of breast cancer and Computed Radiography (CR) is a cost-effective technology for digital mammography. We have demonstrated that CR mammography image quality is viable for Digital Mammography. The image quality of mammograms acquired using Computed Radiography technology was evaluated using the Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). The measurements were made using a 28 kVp beam (RQA M-II) using 2 mm of Al as a filter and a target/filter combination of Mo/Mo. The acquired image bit depth was 16 bits and the pixel pitch for scanning was 50 microns. A Step-Wedge phantom (to measure the Contrast-to-noise ratio (CNR)) and the CDMAM 3.4 Contrast Detail phantom were also used to assess the image quality. The CNR values were observed at varying thickness of PMMA. The CDMAM 3.4 phantom results were plotted and compared to the EUREF acceptable and achievable values. The effect on image quality was measured using the physics metrics. A lower DQE was observed even with a higher MTF. This could be possibly due to a higher noise component present due to the way the scanner was configured. The CDMAM phantom scores demonstrated a contrast-detail comparable to the EUREF values. A cost-effective CR machine was optimized for high-resolution and high-contrast imaging.

  16. Physicians' recommendations for mammography: do tailored messages make a difference?

    PubMed Central

    Skinner, C S; Strecher, V J; Hospers, H

    1994-01-01

    OBJECTIVES. Message tailoring, based on individual needs and circumstances, is commonly used to enhance face-to-face patient counseling. Only recently has individual tailoring become feasible for printed messages. This study sought to determine whether printed tailored recommendations addressing women's specific screening and risk status and perceptions about breast cancer and mammography are more effective than standardized printed recommendations. METHODS. Computer-assisted telephone interviews were conducted with 435 women, aged 40 to 65 years, who had visited family practice groups within the previous 2 years. Subjects were randomly allocated to receive individually tailored or standardized mammography recommendation letters mailed from physicians to patients' homes. Follow-up interviews were conducted 8 months later. RESULTS. Tailored letter recipients were more likely to remember and to have read more of their letters than standardized version recipients. After controlling for baseline status, tailored letter receipt was associated with more favorable follow-up mammography status for women with incomes below $26,000 and for Black women. CONCLUSIONS. Tailored messages are a more effective medium for physicians' mammography recommendations; tailoring may be especially important for women of low socioeconomic status. PMID:8279610

  17. Reactions to Uncertainty and the Accuracy of Diagnostic Mammography

    PubMed Central

    Yi, Joyce P.; Abraham, Linn A.; Miglioretti, Diana L.; Aiello, Erin J.; Gerrity, Martha S.; Reisch, Lisa; Berns, Eric A.; Sickles, Edward A.; Elmore, Joann G.

    2007-01-01

    Background Reactions to uncertainty in clinical medicine can affect decision making. Objective To assess the extent to which radiologists’ reactions to uncertainty influence diagnostic mammography interpretation. Design Cross-sectional responses to a mailed survey assessed reactions to uncertainty using a well-validated instrument. Responses were linked to radiologists’ diagnostic mammography interpretive performance obtained from three regional mammography registries. Participants One hundred thirty-two radiologists from New Hampshire, Colorado, and Washington. Measurement Mean scores and either standard errors or confidence intervals were used to assess physicians’ reactions to uncertainty. Multivariable logistic regression models were fit via generalized estimating equations to assess the impact of uncertainty on diagnostic mammography interpretive performance while adjusting for potential confounders. Results When examining radiologists’ interpretation of additional diagnostic mammograms (those after screening mammograms that detected abnormalities), a 5-point increase in the reactions to uncertainty score was associated with a 17% higher odds of having a positive mammogram given cancer was diagnosed during follow-up (sensitivity), a 6% lower odds of a negative mammogram given no cancer (specificity), a 4% lower odds (not significant) of a cancer diagnosis given a positive mammogram (positive predictive value [PPV]), and a 5% higher odds of having a positive mammogram (abnormal interpretation). Conclusion Mammograms interpreted by radiologists who have more discomfort with uncertainty have higher likelihood of being recalled. PMID:17356992

  18. Screening mammography intervals among postmenopausal hormone therapy users and nonusers

    PubMed Central

    Onega, Tracy; MacKenzie, Todd; Weiss, Julia; Goodrich, Martha; Titus-Ernstoff, Linda

    2013-01-01

    Background The recent decline in US breast cancer incidence rates has been attributed to the marked reduction in use of postmenopausal hormone therapy (HT). An alternative explanation is that women who are not routinely seeking medical care to renew HT prescriptions may be less adherent to recommendations for mammographic screening. To investigate the latter possibility, we compared mammographic intervals according to HT use. Methods Using data (1995–2007) from the New Hampshire Mammography Network (NHMN), a state-based mammography registry, we assessed mammographic intervals corresponding to HT use or nonuse among postmenopausal women. We used linear mixed effects models to assess whether the length of screening mammogram intervals differed according to HT use. Results A total of 310,185 mammograms, representing 76,192 postmenopausal women and 319,353 person-years of screening, were included in the analysis. The median screening interval corresponding to HT use overall was 13.0 months (interquartile range: 12.4–15.1) and for nonuse was 13.1 (interquartile range: 12.4–15.8). Virtually, all screening mammograms occurred within a 2-year interval regardless of HT use or nonuse (98.5 and 98.1%, respectively). Conclusions Our findings indicate that screening mammography intervals are similar whether or not women are using HT. Thus, reduced utilization of screening mammography is unlikely to account for the decrease in breast cancer incidence seen soon after the WHI report. PMID:19844798

  19. What is the point: will screening mammography save my life?

    PubMed Central

    2009-01-01

    Background We analyzed the claim "mammography saves lives" by calculating the life-saving absolute benefit of screening mammography in reducing breast cancer mortality in women ages 40 to 65. Methods To calculate the absolute benefit, we first estimated the screen-free absolute death risk from breast cancer by adjusting the Surveillance, Epidemiology and End Results Program 15-year cumulative breast cancer mortality to account for the separate effects of screening mammography and improved therapy. We calculated the absolute risk reduction (reduction in absolute death risk), the number needed to screen assuming repeated screening, and the survival percentages without and with screening. We varied the relative risk reduction from 10%–30% based on the randomized trials of screening mammography. We developed additional variations of the absolute risk reduction for a screening intervention, including the average benefit of a single screen, as well as the life-saving proportion among patients with earlier cancer detection. Results Because the screen-free absolute death risk is approximately 1% overall but rises with age, the relative risk reduction from repeated screening mammography is about 100 times the absolute risk reduction between the starting ages of 50 and 60. Assuming a base case 20% relative risk reduction, repeated screening starting at age 50 saves about 1.8 (overall range, 0.9–2.7) lives over 15 years for every 1000 women screened. The number needed to screen repeatedly is 1000/1.8, or 570. The survival percentage is 99.12% without and 99.29% with screening. The average benefit of a single screening mammogram is 0.034%, or 2970 women must be screened once to save one life. Mammography saves 4.3% of screen-detectable cancer patients' lives starting at age 50. This means 23 cancers must be found starting at age 50, or 27 cancers at age 40 and 21 cancers at age 65, to save one life. Conclusion The life-saving absolute benefit of screening mammography

  20. Nuclear winter: the continuing debate. Student essay

    SciTech Connect

    Nida, A.V.

    1987-03-23

    This essay examines the debate over the climatic consequences of global nuclear war as related in the so-called Nuclear Winter hypothesis. This review examines the major components of the theory and traces development of the scientific knowledge leading to a second phase of the controversy two years after the first hypothesis. The conclusions of the essay are that the original nuclear winter findings have been altered by later scientific study and, therefore, the political conclusions drawn by Carl Sagan in 1983 can no longer be supported by theory or facts. Continued use of the Crutzen-Birks (Ambio, 1982) and TTAPS (Science, December 1983) studies worst-case evidence from NCAR (Foreign Affairs, Summer 86) represents selective science. Arguing for strategic policy changes based on nuclear winter risks constitutes anti-nuclear rhetoric and not scientific reasoning.

  1. Essays in renewable energy and emissions trading

    NASA Astrophysics Data System (ADS)

    Kneifel, Joshua D.

    Environmental issues have become a key political issue over the past forty years and has resulted in the enactment of many different environmental policies. The three essays in this dissertation add to the literature of renewable energy policies and sulfur dioxide emissions trading. The first essay ascertains which state policies are accelerating deployment of non-hydropower renewable electricity generation capacity into a states electric power industry. As would be expected, policies that lead to significant increases in actual renewable capacity in that state either set a Renewables Portfolio Standard with a certain level of required renewable capacity or use Clean Energy Funds to directly fund utility-scale renewable capacity construction. A surprising result is that Required Green Power Options, a policy that merely requires all utilities in a state to offer the option for consumers to purchase renewable energy at a premium rate, has a sizable impact on non-hydro renewable capacity in that state. The second essay studies the theoretical impacts fuel contract constraints have on an electricity generating unit's compliance costs of meeting the emissions compliance restrictions set by Phase I of the Title IV SO2 Emissions Trading Program. Fuel contract constraints restrict a utility's degrees of freedom in coal purchasing options, which can lead to the use of a more expensive compliance option and higher compliance costs. The third essay analytically and empirically shows how fuel contract constraints impact the emissions allowance market and total electric power industry compliance costs. This paper uses generating unit-level simulations to replicate results from previous studies and show that fuel contracts appear to explain a large portion (65%) of the previously unexplained compliance cost simulations. Also, my study considers a more appropriate plant-level decisions for compliance choices by analytically analyzing the plant level decision-making process to

  2. Digital Mammography in Young Women: Is a Single View Sufficient?

    PubMed Central

    2016-01-01

    Introduction Single view mammography may be a less time consuming, more comfortable and radiation reduced alternative for young women, but there are no studies examining this approach after the implementation of digital mammography into clinical practice. Materials and Methods Retrospective analysis of all mammographies performed in women younger than 40 years during a 24 month period. The sample consisted of 109 women with 212 examined breasts. All patients initially received standard two- view mammography. In the study setting the MLO- views were read by a single viewer and compared to a composite reference standard. Results In this sample 7 malignant findings were present and the review of the MLO-view detected 6 of them (85%). In patients with dense breasts 4 out of 5 malignant findings were found on the single-view (sensitivity 80%) and all 2 malignant findings were detected in patients with low breast density (sensitivity 100%). There were 7 false positive findings (3.3%). i.e. in total 8 out of 212 examined breasts were therefore misinterpreted (3.8%). Conclusion Single view digital mammography detects the vast majority of malignant findings, especially in low density breast tissue and the rate of false-positive findings is within acceptable limits. Therefore this approach may be used in different scenarios (for example in increasing patient throughput, in resource poor settings, reducing radiation burden in the young or in combination with ultrasound to use the strengths of both methods). More research on this topic is needed to establish its potential role in breast imaging. PMID:27134963

  3. Predicting Malignancy from Mammography Findings and Surgical Biopsies

    PubMed Central

    Ferreira, Pedro; Fonseca, Nuno A.; Dutra, Inês; Woods, Ryan; Burnside, Elizabeth

    2013-01-01

    Breast screening is the regular examination of a woman’s breasts to find breast cancer earlier. The sole exam approved for this purpose is mammography. Usually, findings are annotated through the Breast Imaging Reporting and Data System (BIRADS) created by the American College of Radiology. The BIRADS system determines a standard lexicon to be used by radiologists when studying each finding. Although the lexicon is standard, the annotation accuracy of the findings depends on the experience of the radiologist. Moreover, the accuracy of the classification of a mammography is also highly dependent on the expertise of the radiologist. A correct classification is paramount due to economical and humanitarian reasons. The main goal of this work is to produce machine learning models that predict the outcome of a mammography from a reduced set of annotated mammography findings. In the study we used a data set consisting of 348 consecutive breast masses that underwent image guided or surgical biopsy performed between October 2005 and December 2007 on 328 female subjects. The main conclusions are threefold: (1) automatic classification of a mammography, independent on information about mass density, can reach equal or better results than the classification performed by a physician; (2) mass density seems to be a good indicator of malignancy, as previous studies suggested; (3) a machine learning model can predict mass density with a quality as good as the specialist blind to biopsy, which is one of our main contributions. Our model can predict malignancy in the absence of the mass density attribute, since we can fill up this attribute using our mass density predictor. PMID:24363962

  4. Postmortem validation of breast density using dual-energy mammography

    SciTech Connect

    Molloi, Sabee Ducote, Justin L.; Ding, Huanjun; Feig, Stephen A.

    2014-08-15

    Purpose: Mammographic density has been shown to be an indicator of breast cancer risk and also reduces the sensitivity of screening mammography. Currently, there is no accepted standard for measuring breast density. Dual energy mammography has been proposed as a technique for accurate measurement of breast density. The purpose of this study is to validate its accuracy in postmortem breasts and compare it with other existing techniques. Methods: Forty postmortem breasts were imaged using a dual energy mammography system. Glandular and adipose equivalent phantoms of uniform thickness were used to calibrate a dual energy basis decomposition algorithm. Dual energy decomposition was applied after scatter correction to calculate breast density. Breast density was also estimated using radiologist reader assessment, standard histogram thresholding and a fuzzy C-mean algorithm. Chemical analysis was used as the reference standard to assess the accuracy of different techniques to measure breast composition. Results: Breast density measurements using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean algorithm, and dual energy were in good agreement with the measured fibroglandular volume fraction using chemical analysis. The standard error estimates using radiologist reader assessment, standard histogram thresholding, fuzzy C-mean, and dual energy were 9.9%, 8.6%, 7.2%, and 4.7%, respectively. Conclusions: The results indicate that dual energy mammography can be used to accurately measure breast density. The variability in breast density estimation using dual energy mammography was lower than reader assessment rankings, standard histogram thresholding, and fuzzy C-mean algorithm. Improved quantification of breast density is expected to further enhance its utility as a risk factor for breast cancer.

  5. Predicting Malignancy from Mammography Findings and Surgical Biopsies.

    PubMed

    Ferreira, Pedro; Fonseca, Nuno A; Dutra, Inês; Woods, Ryan; Burnside, Elizabeth

    2011-11-01

    Breast screening is the regular examination of a woman's breasts to find breast cancer earlier. The sole exam approved for this purpose is mammography. Usually, findings are annotated through the Breast Imaging Reporting and Data System (BIRADS) created by the American College of Radiology. The BIRADS system determines a standard lexicon to be used by radiologists when studying each finding. Although the lexicon is standard, the annotation accuracy of the findings depends on the experience of the radiologist. Moreover, the accuracy of the classification of a mammography is also highly dependent on the expertise of the radiologist. A correct classification is paramount due to economical and humanitarian reasons. The main goal of this work is to produce machine learning models that predict the outcome of a mammography from a reduced set of annotated mammography findings. In the study we used a data set consisting of 348 consecutive breast masses that underwent image guided or surgical biopsy performed between October 2005 and December 2007 on 328 female subjects. The main conclusions are threefold: (1) automatic classification of a mammography, independent on information about mass density, can reach equal or better results than the classification performed by a physician; (2) mass density seems to be a good indicator of malignancy, as previous studies suggested; (3) a machine learning model can predict mass density with a quality as good as the specialist blind to biopsy, which is one of our main contributions. Our model can predict malignancy in the absence of the mass density attribute, since we can fill up this attribute using our mass density predictor. PMID:24363962

  6. Automated Analysis of Mammography Phantom Images

    NASA Astrophysics Data System (ADS)

    Brooks, Kenneth Wesley

    The present work stems from the hypothesis that humans are inconsistent when making subjective analyses of images and that human decisions for moderately complex images may be performed by a computer with complete objectivity, once a human acceptance level has been established. The following goals were established to test the hypothesis: (1) investigate observer variability within the standard mammographic phantom evaluation process; (2) evaluate options for high-resolution image digitization and utilize the most appropriate technology for standard mammographic phantom film digitization; (3) develop a machine-based vision system for evaluating standard mammographic phantom images to eliminate effects of human variabilities; and (4) demonstrate the completed system's performance against human observers for accreditation and for manufacturing quality control of standard mammographic phantom images. The following methods and procedures were followed to achieve the goals of the research: (1) human variabilities in the American College of Radiology accreditation process were simulated by observer studies involving 30 medical physicists and these were compared to the same number of diagnostic radiologists and untrained control group of observers; (2) current digitization technologies were presented and performance test procedures were developed; three devices were tested which represented commercially available high, intermediate and low-end contrast and spatial resolution capabilities; (3) optimal image processing schemes were applied and tested which performed low, intermediate and high-level computer vision tasks; and (4) the completed system's performance was tested against human observers for accreditation and for manufacturing quality control of standard mammographic phantom images. The results from application of the procedures were as follows: (1) the simulated American College of Radiology mammography accreditation program phantom evaluation process demonstrated

  7. Breast cancer and mammography: knowledge, attitudes, practices and patient satisfaction post-mammography at the San Fernando General Hospital, Trinidad.

    PubMed

    Gosein, Maria A; Pinto Pereira, Snehal M; Narinesingh, Dylan; Ameeral, Anthony

    2014-02-01

    Self-administered questionnaires were completed by 314 Trinidadian women, 40 years and older, to ascertain their breast cancer knowledge, attitudes, and practices. Those with higher education had greater knowledge of the benefits of early breast cancer detection (p < .01) and knew that an abnormal mammography result (p = .01) or recall (p < .01) was not necessarily indicative of breast cancer. Inaccurate beliefs particularly that breast compression causes cancer were more likely among those with the least education (p = .04). Obesity and alcohol were identified as risk factors by 29.3% and 12.4%, respectively. Over two-thirds (70%) of mammograms were primarily the doctor's decision. Over 90% of women were satisfied post-mammography, most (94.6%) with plans for future use. Some (15.6%) reported pain and 48.7% reported discomfort, with over 70% of these finding the examination less painful than anticipated. Targeted culturally sensitive awareness campaigns are needed. Clinicians must be sensitized to their importance in recommending mammography. Data on patient satisfaction and pain perception can be publicized to encourage women who are hesitant about mammography. PMID:24509017

  8. Essays on environmental policies, corruption, and energy

    NASA Astrophysics Data System (ADS)

    Baksi, Soham

    This thesis consists of four essays. The first essay looks at pollution taxation under capital mobility, and analyzes the role of pre-commitment by countries to their pollution tax rate. A polluting firm sells its product in two countries, and can locate and produce in a single country or in both countries. Due to the discrete-choice nature of the firm's location problem, the countries' welfare functions are discontinuous in their pollution tax rate. We show that when the countries cannot pre-commit to their pollution tax, the firm can still engender tax competition between them by strategically locating in both the countries. Moreover, pre-commitment pollution taxation may not be welfare improving for the countries, although it always makes the firm better off. The second essay studies the effect of liberalization on corruption. Corruptible inspectors enforce an environmental regulation on firms, and are monitored by an honest regulator. Liberalization not only increases the variety of goods and the marginal utility of accepting a bribe, but also puts pressure on the regulator to curb corruption. The interaction of these two effects can cause corruption to initially increase with liberalization, and then decrease beyond a threshold. Moreover, equilibrium corruption is lower when the regulator is able to pre-commit to her monitoring frequency. The third essay analyzes optimal labeling (information revelation) procedures for hidden attributes of credence goods. Consumers are heterogeneous in their preference for the hidden attribute, and producers can either self-label their products, or have them certified by a third party. The government can impose self or third-party labeling requirements on either the "green" or the "brown" producers. When corrupt producers can affix spurious labels, the government needs to monitor them. A mandatory self-labeling policy is shown to generally dominate mandatory third-party labeling. The fourth essay develops formulas for

  9. Three essays on energy efficiency policy

    NASA Astrophysics Data System (ADS)

    Kabiri, Maryam

    This thesis is comprised of three essays which explore selected aspects of demand side energy efficiency policy of International Energy Conservation Codes (IECC). The first essay models the adoption of IECC in the U.S. between 1998 and 2010. An ordered probit model with IECC adoption as the dependent variable is used to test if a set of socio-economics, political, spatial, and environmental factors predict the residential building energy code adoption. The results show that higher energy price, relative political extraction, climate extremes, pollution level, and population growth predict IECC adoption in the sample. The diffusion variable (share of neighbor states with IECC) is shown to have large impacts on the probability of IECC adoption. The next two essays examine the effect of IECC on residential electricity consumption. The second essay investigates the impact of International Energy Conservation Codes (IECC) on per-capita residential electricity consumption for 44 U.S. states from 1981-2008. Applying the pooled mean group (PMG) model developed by Pesaran et al. (1999), and controlling for energy specific demand factors such as: prices, income, heating degree days, and cooling degree days, I find that there is an overall 2% decrease in new residential buildings per-capita electricity consumption in the states which adopted any version of IECC. The new residential buildings per-capita electricity consumption has decreased by about 2.5% and 5% in the states with IECC 2000 and IECC 2003 respectively. The third essay examines the impact of building energy code on the household electricity consumption in three states in U.S. To do so; I construct a pseudo panel using household level data from the American Community Survey (ACS) over the period 2005-2010. By constructing pseudo panel, we are able to track cohorts of relatively homogeneous individuals over time, and control for cohort unobserved heterogeneity that may bias the results of cross sectional estimates

  10. Experience with a proposed teleradiology system for digital mammography

    NASA Astrophysics Data System (ADS)

    Saulnier, Emilie T.; Mitchell, Robert J.; Abdel-Malek, Aiman A.; Dudding, Kathryn E.

    1995-05-01

    Teleradiology offers significant improvement in efficiency and effectiveness over current practices in traditional film/screen-based diagnosis. In the context of digital mammography, the increasing number of women who need to be screened for breast cancer, including those in remote rural regions, make the advantages of teleradiology especially attractive for digital mammography. At the same time, the size and resolution of digital mammograms are among the most challenging to support in a cost effective teleradiology system. This paper describes a teleradiology architecture developed for use with digital mammography by GE Corporate Research and Development in collaboration with Massachusetts General Hospital under National Cancer Institute (NCI/NIH) grant number R01 CA60246-01. Experience with a testbed prototype is described. The telemammography architecture is intended to consist of a main mammography diagnostic site serving several remote screening sites. As patient exams become available, they are forwarded by an image server to the diagnostic site over a WAN communications link. A radiologist at the diagnostic site views a patient exam as it arrives, interprets it, and then relays a report back to the technician at the remote site. A secondary future scenario consists of mobile units which forward images to a remote site, which then forwards them to the main diagnostic site. The testbed architecture is based on the Digital Imaging and Communications in Medicine (DICOM) standard, created by the American College of Radiology (ACR) and National Electrical Manufacturers Association (NEMA). A specification of vendor-independent data formats and data transfer services for digital medical images, DICOM specifies a protocol suite starting at the application layer downward, including the TCP/IP layers. The current DICOM definition does not provide an information element that is specifically tailored to mammography, so we have used the DICOM secondary capture data format

  11. CJS debate: Is mammography useful in average-risk screening for breast cancer?

    PubMed Central

    Brackstone, Muriel; Latosinsky, Steven; Saettler, Elizabeth; George, Ralph

    2016-01-01

    Summary Given the recent debate over breast cancer screening that was reignited by the 25-year follow-up data from the Canadian National Breast Screening Study, the Canadian Journal of Surgery commissioned a group of Canadian experts to debate the value of screening mammography. We discuss the Canadian study and summarize the arguments in favour of and against screening mammography for average-risk patients. We also provide summary recommendations for the use of mammography. PMID:26574707

  12. Veridical and false pictorial memory in individuals with and without mental retardation.

    PubMed

    Carlin, Michael T; Toglia, Michael P; Wakeford, Yvonne; Jakway, Allison; Sullivan, Kate; Hasel, Lisa

    2008-05-01

    Veridical and false pictorial recognition were assessed in individuals with mental retardation; groups were matched for MA and CA. Pictures were viewed in either a generative or static format at acquisition. The individuals with mental retardation and those in the MA-matched group had higher rates of false memories for critical items and lower hit rates than did their CA-matched peers. The mental retardation group demonstrated an acquiescent response bias (i.e., high novel false-alarm rate). When data were corrected for this bias, those with mental retardation had significantly lower hit rates but equivalent false-alarm rates to the MA-matched participants. Results are discussed in terms of pictorial distinctiveness and within the frameworks of activation monitoring and fuzzy trace theory. PMID:18407722

  13. Unconscious learning processes: mental integration of verbal and pictorial instructional materials.

    PubMed

    Kuldas, Seffetullah; Ismail, Hairul Nizam; Hashim, Shahabuddin; Bakar, Zainudin Abu

    2013-12-01

    This review aims to provide an insight into human learning processes by examining the role of cognitive and emotional unconscious processing in mentally integrating visual and verbal instructional materials. Reviewed literature shows that conscious mental integration does not happen all the time, nor does it necessarily result in optimal learning. Students of all ages and levels of experience cannot always have conscious awareness, control, and the intention to learn or promptly and continually organize perceptual, cognitive, and emotional processes of learning. This review suggests considering the role of unconscious learning processes to enhance the understanding of how students form or activate mental associations between verbal and pictorial information. The understanding would assist in presenting students with spatially-integrated verbal and pictorial instructional materials as a way of facilitating mental integration and improving teaching and learning performance. PMID:23556145

  14. Molecular gas clumps from the destruction of icy bodies in the β Pictoris debris disk.

    PubMed

    Dent, W R F; Wyatt, M C; Roberge, A; Augereau, J-C; Casassus, S; Corder, S; Greaves, J S; de Gregorio-Monsalvo, I; Hales, A; Jackson, A P; Hughes, A Meredith; Lagrange, A-M; Matthews, B; Wilner, D

    2014-03-28

    Many stars are surrounded by disks of dusty debris formed in the collisions of asteroids, comets, and dwarf planets, but is gas also released in such events? Observations at submillimeter wavelengths of the archetypal debris disk around β Pictoris show that 0.3% of a Moon mass of carbon monoxide orbits in its debris belt. The gas distribution is highly asymmetric, with 30% found in a single clump 85 astronomical units from the star, in a plane closely aligned with the orbit of the inner planet, β Pictoris b. This gas clump delineates a region of enhanced collisions, either from a mean motion resonance with an unseen giant planet or from the remnants of a collision of Mars-mass planets. PMID:24603151

  15. The Influence of Emotional State and Pictorial Cues on Perceptual Judgments

    SciTech Connect

    Kimberly R. Raddatz; Abigail Werth; Tuan Q. Tran

    2007-10-01

    Perspective displays (e.g., CDTI) are commonly used as decision aids in environments characterized by periods of high emotional arousal (e.g., terrain enhanced primary flight displays). However, little attention has been devoted to understanding how emotional state, independently or in conjunction with other perceptual factors (e.g., pictorial depth cues), can impact perceptual judgments. Preliminary research suggests that induced emotional state (positive or negative) adversely impacts size comparisons in perspective displays (Tran & Raddatz, 2006). This study further investigated how size comparisons are affected by emotional state and pictorial depth cues while attenuating the limitations of the Tran & Raddatz (2006) study. Results confirmed that observers do make slower judgments under induced emotional state. However, observers under negative emotional state showed higher sensitivity (d’) and required more evidence to respond that a size difference exists (response bias) than observers under positive emotional state. Implications for display design and human performance are discussed.

  16. Initial Validation of a Brief Pictorial Measure of Caregiver Aggression: The Family Aggression Screening Tool.

    PubMed

    Cecil, Charlotte A M; McCrory, Eamon J; Viding, Essi; Holden, George W; Barker, Edward D

    2016-06-01

    In the present study, we report on the development and initial psychometric properties of the Family Aggression Screening Tool (FAST). The FAST is a brief, self-report tool that makes use of pictorial representations to assess experiences of caregiver aggression, including direct victimization and exposure to intimate partner violence. It is freely available on request and takes under 5 minutes to complete. Psychometric properties of the FAST were investigated in a sample of 168 high-risk youth aged 16 to 24 years. For validation purposes, maltreatment history was assessed using the Childhood Trauma Questionnaire; levels of current psychiatric symptoms were also assessed. Internal consistency of the FAST was good. Convergent validity was supported by strong and discriminative associations with corresponding Childhood Trauma Questionnaire subscales. The FAST also correlated significantly with multi-informant reports of psychiatric symptomatology. Initial findings provide support for the reliability and validity of the FAST as a brief, pictorial screening tool of caregiver aggression. PMID:26085494

  17. Radiography of Cardiac Conduction Devices: A Pictorial Review of Pacemakers and Implantable Cardioverter Defibrillators

    PubMed Central

    Torres-Ayala, Stephanie C; Santacana-Laffitte, Guido; Maldonado, José

    2014-01-01

    Cardiac conduction devices (CCDs) depend on correct anatomic positioning to function properly. Chest radiography is the preferred imaging modality to evaluate CCD's anatomic location, lead wire integrity, and help in identifying several complications. In this pictorial review, our goal is to familiarize radiologists with CCD implantation techniques, appropriate positioning of the device, common causes of malfunction, methods to improve report accuracy, and assure maximal therapeutic benefit. PMID:25806132

  18. Exocomet Circumstellar Fe I Absorption in the Beta Pictoris Gas Disk

    NASA Astrophysics Data System (ADS)

    Welsh, Barry Y.; Montgomery, Sharon

    2016-06-01

    We present an archival study of 27 circumstellar Fe i (λ3860 Å) and Ca ii (λ3933 Å) absorption spectra of the β Pictoris system recorded over the 2003–2014 timeframe. We have detected several transient absorption events at velocities red-shifted by >+20 km s‑1 from the main central absorption line profiles of both Fe i and Ca ii. Such events can be attributed to the presence of kilometer-sized infalling evaporating bodies (i.e., exocomets) on their grazing approach to the central star. The majority of the transient absorption events detected in the Fe i profiles occur at velocities in the +35 to +50 km s‑1 range. This is consistent with that found for Ca ii gas that has been sublimated from the “D” family of β Pictoris exocomets recently found by Kiefer et al. These spectra also reveal that the strength of the main component of the Fe i absorption line at V helio ∼ +21 km s‑1 has weakened by ∼30% since 2011. Since neutrals, when ionized, are the main source of the ion-braking mechanism of Brandeker for circumstellar gas in the β Pictoris system, then this may have some measurable effect on the size and/or location of the main circumstellar gas disk. Finally we note that we have failed to detect any circumstellar Fe i absorption in our previously reported spectra of similar gas disks surrounding 28 young A-type stars. Thus, it would appear that the β Pictoris is anomalous with regards to circumstellar Fe i absorption.

  19. Mammographic density is the main correlate of tumors detected on ultrasound but not on mammography.

    PubMed

    Häberle, Lothar; Fasching, Peter A; Brehm, Barbara; Heusinger, Katharina; Jud, Sebastian M; Loehberg, Christian R; Hack, Carolin C; Preuss, Caroline; Lux, Michael P; Hartmann, Arndt; Vachon, Celine M; Meier-Meitinger, Martina; Uder, Michael; Beckmann, Matthias W; Schulz-Wendtland, Rüdiger

    2016-11-01

    Although mammography screening programs do not include ultrasound examinations, some diagnostic units do provide women with both mammography and ultrasonography. This article is concerned with estimating the risk of a breast cancer patient diagnosed in a hospital-based mammography unit having a tumor that is visible on ultrasound but not on mammography. A total of 1,399 women with invasive breast cancer from a hospital-based diagnostic mammography unit were included in this retrospective study. For inclusion, mammograms from the time of the primary diagnosis had to be available for computer-assisted assessment of percentage mammographic density (PMD), as well as Breast Imaging Reporting and Data System (BIRADS) assessment of mammography. In addition, ultrasound findings were available for the complete cohort as part of routine diagnostic procedures, regardless of any patient or imaging characteristics. Logistic regression analyses were conducted to identify predictors of mammography failure, defined as BIRADS assessment 1 or 2. The probability that the visibility of a tumor might be masked at diagnosis was estimated using a regression model with the identified predictors. Tumors were only visible on ultrasound in 107 cases (7.6%). PMD was the strongest predictor for mammography failure, but age, body mass index and previous breast surgery also influenced the risk, independently of the PMD. Risk probabilities ranged from 1% for a defined low-risk group up to 40% for a high-risk group. These findings might help identify women who should be offered ultrasound examinations in addition to mammography. PMID:27389655

  20. Three essays on "making" electric power markets

    NASA Astrophysics Data System (ADS)

    Kench, Brian Thomas

    2000-10-01

    Technological change over the past three decades has altered most of the basic conditions in the electric power industry. Because of technical progress, the dominant paradigm has shifted from the provision of electric power by regulated and vertically integrated local natural monopolies to competition and vertical separation. In the first essay I provide a historical context of the electric industry's power current deregulation debate. Then a dynamic model of induced institutional change is used to investigate how endogenous technological advancements have induced radical institutional change in the generation and transmission segments of the electric power industry. Because the Federal Energy Regulatory Commission (FERC) ordered regulated utilities to provide open access to their transmission networks and to separate their generation and transmission functions, transmission networks have been used more intensively and in much different ways then in the past. The second essay tests experimentally the predictions of neoclassical theory for a radial electric power market under two alternative deregulated transmission institutions: financial transmission rights and physical transmission rights. Experimental evidence presented there demonstrates that an electric power market with physical transmission rights governing its transmission network generates more "right" market signals relative to a transmission network governed by financial transmission rights. The move to a greater reliance on markets for electric power is an idea that has animated sweeping and dramatic changes in the traditional business of electric power. The third essay examines two of the most innovative and complex initiatives of making electric power markets in the United States: California and PJM. As those markets mature and others are made, they must revise their governance mechanisms to eliminate rules that create inefficiency and adopt rules that work efficiently elsewhere. I argue that

  1. [Essay on the myth of oedipus].

    PubMed

    Costa, Néstor E

    2012-01-01

    Jung conceptualized the collective unconscious as the locus of the myths, the absolutely genuine and primary patterns of thinking and feeling of humanity. The legend of Oedipus or myth of incest is a irrefutable proof of its eternal validity. The present essay is an attempt to take an alternative look to a history that belong to all of us. Situations that are developed in this drama, like the characters involved in it may charge significance as an archetypal and essentially symbolic interpretation. PMID:23145377

  2. Essays on consequences of economic integration

    NASA Astrophysics Data System (ADS)

    Chintrakarn, Pandej

    2007-12-01

    Economic integration is a term used to describe how different aspects between economies are integrated. As economic integration increases, the barriers of trade between markets diminishes. The most integrated economy today, between independent nations, is the European Union and its euro zone. This dissertation consists of three essays which examine consequences of economic integration. The debate over the environmental consequences of free trade is not only quite heated, but also entails significant policy ramifications. Recently, cross-sectional analysis at the country level has made use of exogenous determinants of trade to identify the causal effect of trade on the environment, finding moderate evidence of a beneficial impact of expanded trade on environmental quality. Given the stakes involved, the first essay revisits this finding using subnational data on 'trade' flows across US states and several measures of pollution. Not only does the analysis shed further light on the debate at the international level, but also addresses a heretofore unexamined question: Does greater inter-regional commerce at the subnational level harm the environment? The findings are striking, providing further evidence against a negative environmental impact of trade for the majority of measures analyzed. However, several sources of heterogeneity arise that are noteworthy. The second essay investigates the effect of the euro on trade among EMU members. Using various semi-nonparametric methods based on matching, the results suggest that the euro has a statistical and economic impact on trade. The results show that two countries sharing the euro currency trade somewhere between 9% and 14% more than other country-pairs. In addition, there is no evidence of trade diversion due to the euro. In one strand of research, analysts examine trends in and the determinants of energy usage and intensity. In a second strand, researchers analyze the impact of trade flows on environmental outcomes

  3. ESSAYS ON SCIENCE AND SOCIETY: Taking Responsibility.

    PubMed

    Rotblat, J

    2000-08-01

    Joseph Rotblat was born in Warsaw in 1908. He trained in nuclear physics and later specialized in radiation biology. He was awarded the Nobel Peace Prize in 1995, with the Pugwash Conferences on Science and World Affairs, "for their efforts to diminish the part played by nuclear arms in international politics and in the longer run to eliminate such arms." In this essay, he reflects on his experiences and recounts how he has applied his ethical principles to his work as a scientist and educator in Poland, the United Kingdom, and the world. He urges other scientists to apply ethical considerations for the survival of humankind above all others. PMID:17819567

  4. Imitation is the sincerest form of flattery: is 49 Ceti the new Beta Pictoris?

    NASA Astrophysics Data System (ADS)

    Welsh, Barry; Montgomery, S. L.; Alu, D.; Lallement, R.

    2014-01-01

    The young (40Myr) A1-type star 49 Ceti is thought to possess many of the same physical characteristics as Beta Pictoris, whose circumstellar gas and debris dust disks are the most well-studied of all exoplanet systems. As part of a campaign to monitor circumstellar activity in the gas disk(s) surrounding 49 Ceti, we present ground-based high spectral resolution observations (R ~ 60,000) of the visible circumstellar absorption lines recorded in conjunction with ultraviolet observations using the STIS instrument on HST in August 2013 (see presentation by Roberge et al at this conference). Our data, which spans a 6-week observational period, reveals significant variability in the properties of the circumstellar gas absorption which can be attributed to evaporating ionized Ca gas liberated by Kuiper Belt-like objects as they fall towards the central star. Similar behavior has been routinely observed towards Beta Pictoris. However, unlike Beta Pictoris we have observed anomalous behavior of the NaI and CaII IR-triplet lines in this extremely ‘active” debris disk system of 49 Ceti.

  5. Lessons from New Zealand's introduction of pictorial health warnings on tobacco packaging.

    PubMed

    Hoek, Janet; Wilson, Nick; Allen, Matthew; Edwards, Richard; Thomson, George; Li, Judy

    2010-11-01

    While international evidence suggests that featuring pictorial health warnings on tobacco packaging is an effective tobacco control intervention, the process used to introduce these new warnings has not been well documented. We examined relevant documents and interviewed officials responsible for this process in New Zealand. We found that, despite tobacco companies' opposition to pictorial health warnings and the resource constraints facing health authorities, the implementation process was generally robust and successful. Potential lessons for other countries planning to introduce or refresh existing pictorial health warnings include: (i) strengthening the link between image research and policy; (ii) requiring frequent image development and refreshment; (iii) using larger pictures (e.g. 80% of the front of the packet); (iv) developing themes that recognize concerns held by different smoker sub-groups; and (v) running integrated mass media campaigns when the warnings are introduced. All countries could also support moves by the World Health Organization Framework Convention on Tobacco Control's Secretariat to develop an international bank of copyright-free warnings. PMID:21076568

  6. Perceptually relevant evaluation of noise power spectra in adaptive pictorial systems

    NASA Astrophysics Data System (ADS)

    Jenkin, Robin B.; Keelan, Brian W.

    2011-01-01

    Noise Power Spectra (NPS) are traditionally measured using uniform areas of tone. Adaptive algorithms, such as noise reduction, demosaicing, and sharpening, can modify their behavior based on underlying image structure. In particular, noise reduction algorithms may suppress noise more strongly in perfectly uniform areas than they would in those with modest variations, as found in actual pictorial images, and so yield unrepresentative NPS. This phenomenon would be similar in nature to the susceptibility of high-contrast-edges to adaptive sharpening and the subsequent over-estimation of effective pictorial modulation transfer function by some targets. Experimentation is described that examines the effect of modern adaptive noise reduction algorithms on the NPS of images containing ramps of varying gradient. Gradients are chosen based on a survey of consumer images from areas where noise is typically noticeable, such as blue sky, walls and faces. Although loss in performance of adaptive noise reduction is observed as gradients increase, the effect is perceptually small when weighted according to the frequency of occurrence of the gradients in pictorial imaging. The significant additional complexity of measuring gradient-based NPS does not appear to be justified; measuring NPS from uniform areas of tone should suffice for most perceptual work.

  7. Recent research results in stereo 3-D pictorial displays at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Parrish, Russell V.; Busquets, Anthony M.; Williams, Steven P.

    1990-01-01

    Recent results from a NASA-Langley program which addressed stereo 3D pictorial displays from a comprehensive standpoint are reviewed. The program dealt with human factors issues and display technology aspects, as well as flight display applications. The human factors findings include addressing a fundamental issue challenging the application of stereoscopic displays in head-down flight applications, with the determination that stereoacuity is unaffected by the short-term use of stereo 3D displays. While stereoacuity has been a traditional measurement of depth perception abilities, it is a measure of relative depth, rather than actual depth (absolute depth). Therefore, depth perception effects based on size and distance judgments and long-term stereo exposure remain issues to be investigated. The applications of stereo 3D to pictorial flight displays within the program have repeatedly demonstrated increases in pilot situational awareness and task performance improvements. Moreover, these improvements have been obtained within the constraints of the limited viewing volume available with conventional stereo displays. A number of stereo 3D pictorial display applications are described, including recovery from flight-path offset, helicopter hover, and emulated helmet-mounted display.

  8. A SMACK Model of Colliding Planetesimals in the β Pictoris Debris Disk

    NASA Astrophysics Data System (ADS)

    Nesvold, Erika R.; Kuchner, Marc J.

    2015-12-01

    We present a new model of the β Pictoris disk-and-planet system that simulates both the planetesimal collisions and the dynamics of the resulting dust grains, allowing us to model features and asymmetries in both thermal and scattered light images of the disk. Our two-part model first simulates the collisional and dynamical evolution of the planetesimals with the Superparticle-Method Algorithm for Collisions in Kuiper belts and then simulates the dynamical evolution of the resulting dust grains with a standard Bulirsch-Stoer N-body integrator. Given the observed inclination and eccentricity of the β Pictoris b planet, the model neatly ties together several features of the disk: the central hole in the submillimeter images, the two-disk “x”-pattern seen in scattered light, and possibly even the clumpy gas seen by ALMA. We also find that most of the dust in the β Pictoris system is likely produced outside the ring at 60-100 AU. Instead of a birth ring, this disk has a “stirring ring” at 60-100 AU where the high-velocity collisions produced by the secular wave launched by the planet are concentrated. The two-disk x-pattern arises because collisions occur more frequently at the peaks and troughs of the secular wave. The perturbations of the disk in this region create an azimuthally and vertically asymmetric spatial distribution of collisions, which could yield an azimuthal clump of gas without invoking resonances or an additional planet.

  9. Sister chromatid exchanges in peripheral lymphocytes after preoperative mammography

    SciTech Connect

    Husum, B.; Wulf, H.C.; Niebuhr, E.

    1981-09-01

    Examination of sister chromatid exchanges (SCE) in peripheral lymphocytes may be useful for evaluating in vivo exposure to chemical mutagens. In vitro exposure of human lymphocytes to low levels of ionizing radiation has failed to produce increased SCE rates. Scarcity of information about the SCE test system and in vivo exposure to radiation prompted the present study of SCE rates in peripheral lymphocytes in women investigated with mammography prior to operation because of a tumor of the breast. In 64 of a total of 131 women a mammography was performed before the operation. The two groups of patients were identical with respect to age, smoking habits, and incidence of malignancy of the mammary tumors. SCE rates were examined in 30 metaphases from each patient following cultivation of peripheral blood lymphocytes using the BrdU/Giemsa technique.

  10. Single photon counter for digital x-ray mammography tomosynthesis

    SciTech Connect

    Goldan, Amir H.; Karim, Karim S.; Rowlands, John A.

    2006-05-15

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, photon counting pixel for digital mammography tomosynthesis in 0.18 {mu}m crystalline silicon complementary metal-oxide semiconductor technology. The design comprises of a low noise, charge-integrating amplifier, a low offset voltage comparator, a decision-making unit, a mode selector, and a pseudorandom counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  11. A comparison of the performance of digital mammography systems

    SciTech Connect

    Monnin, P.; Gutierrez, D.; Bulling, S.; Guntern, D.; Verdun, F. R.

    2007-03-15

    An objective analysis of image quality parameters was performed for six digital mammography systems. The presampled modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) for the systems were determined at different doses, for 28 kVp with a Mo/Mo or W/Al target/filter combination and 2 mm of additional aluminium filtration. The flat-panel units have higher MTF and DQE in the mid to high frequency range than standard CR systems. The highest DQE, over the whole dose range, is for the slit-scanning direct photon counting system. Dual-side read CR can overcome the inherent x-ray absorption and signal collection limitations of standard CR mammography, improving the low-frequency DQE by 40%, to the same level as full-field systems, but it does not improve the poor spatial resolution of phosphor.

  12. An SVM Based Approach for the Analysis Of Mammography Images

    SciTech Connect

    Gan, X.; Kapsokalivas, L.; Skaliotis, A.; Steinhoefel, K.; Tangaro, S.

    2007-09-06

    Mammography is among the most popular imaging techniques used in the diagnosis of breast cancer. Nevertheless distinguishing between healthy and ill images is hard even for an experienced radiologist, because a single image usually includes several regions of interest (ROIs). The hardness of this classification problem along with the substantial amount of data, gathered from patients' medical history, motivates the use of a machine learning approach as part of a CAD (Computer Aided Detection) tool, aiming to assist radiologists in the characterization of mammography images. Specifically, our approach involves: i) the ROI extraction, ii) the Feature Vector extraction, iii) the Support Vector Machine (SVM) classification of ROIs and iv) the characterization of the whole image. We evaluate the performance of our approach in terms of the SVM's training and testing error and in terms of ROI specificity - sensitivity. The results show a relation between the number of features used and the SVM's performance.

  13. Motion artifacts in dual-energy contrast-enhanced mammography

    NASA Astrophysics Data System (ADS)

    Allec, Nicholas; Abbaszadeh, Shiva; Lewin, John M.; Karim, Karim S.

    2012-03-01

    Several strategies have been investigated to acquire both low- and high-energy images simultaneously for contrastenhanced mammography (CEM). However, for the dual-energy technique where the existing conventional mammography infrastructure can be leveraged, low- and high-energy images are acquired using two separate exposures and the finite time between image acquisition leads to motion artifacts in the combined image. Motion artifacts lead to greater noise in the combined image and affect image quality, however the relationship between them is not clear. In this study we examine motion artifacts in dual-energy CEM and their impact on anatomical noise in the combined image and tumor detectability. To study the impact of motion artifacts, a cascaded systems model is extended to include such motion artifacts. An ideal observer model is used to quantify the performance and CEM images from a previous clinical study are used for comparison of the extended model.

  14. A comparison of the performance of digital mammography systems.

    PubMed

    Monnin, P; Gutierrez, D; Bulling, S; Guntern, D; Verdun, F R

    2007-03-01

    An objective analysis of image quality parameters was performed for six digital mammography systems. The presampled modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) for the systems were determined at different doses, for 28 kVp with a Mo/Mo or W/Al target/filter combination and 2 mm of additional aluminium filtration. The flat-panel units have higher MTF and DQE in the mid to high frequency range than standard CR systems. The highest DQE, over the whole dose range, is for the slit-scanning direct photon counting system. Dual-side read CR can overcome the inherent x-ray absorption and signal collection limitations of standard CR mammography, improving the low-frequency DQE by 40%, to the same level as full-field systems, but it does not improve the poor spatial resolution of phosphor. PMID:17441236

  15. Mammography X-Ray Spectra Simulated with Monte Carlo

    SciTech Connect

    Vega-Carrillo, H. R.; Gonzalez, J. Ramirez; Manzanares-Acuna, E.; Hernandez-Davila, V. M.; Villasana, R. Hernandez; Mercado, G. A.

    2008-08-11

    Monte Carlo calculations have been carried out to obtain the x-ray spectra of various target-filter combinations for a mammography unit. Mammography is widely used to diagnose breast cancer. Further to Mo target with Mo filter combination, Rh/Rh, Mo/Rh, Mo/Al, Rh/Al, and W/Rh are also utilized. In this work Monte Carlo calculations, using MCNP 4C code, were carried out to estimate the x-ray spectra produced when a beam of 28 keV electrons did collide with Mo, Rh and W targets. Resulting x-ray spectra show characteristic x-rays and continuous bremsstrahlung. Spectra were also calculated including filters.

  16. [First results of mammography with a screen film (author's transl)].

    PubMed

    Paterok, E M; Säbel, M; Weishaar, J

    1979-01-01

    In order to find a convenient, "dose sparing" mammography method, 152 breasts were examined comparatively with a conventional film without intensifying screens (Definix Medical of Kodak) and with a screen film (screen: MR 50, film: Mammoray RP 3 PE FW of Agfa Gevaert). The quality of the low-dose pictures was generally satisfactory. With regard to the exposure to radiation of the breast which is considerably lower if a screen film is used, it seems necessary to develop an automatic exposure control for this method, to further ameliorate films and screens, and to optimize the technical conditions for mammography. The authors underline the possibility to use simultaneously the oblique exposure methods, which would be a further step towards a reduction of the dose. PMID:760273

  17. Nonlinear Elasto-Mammography for Characterization of Breast Tissue Properties

    PubMed Central

    Wang, Z. G.; Liu, Y.; Wang, G.; Sun, L. Z.

    2011-01-01

    Quantification of the mechanical behavior of normal and cancerous tissues has important implication in the diagnosis of breast tumor. The present work extends the authors' nonlinear elastography framework to incorporate the conventional X-ray mammography, where the projection of displacement information is acquired instead of full three-dimensional (3D) vector. The elastic parameters of normal and cancerous breast tissues are identified by minimizing the difference between the measurement and the corresponding computational prediction. An adjoint method is derived to calculate the gradient of the objective function. Simulations are conducted on a 3D breast phantom consisting of the fatty tissue, glandular tissue, and cancerous tumor, whose mechanical responses are hyperelastic in nature. The material parameters are identified with consideration of measurement error. The results demonstrate that the projective displacements acquired in X-ray mammography provide sufficient constitutive information of the tumor and prove the usability and robustness of the proposed method and algorithm. PMID:22235197

  18. An SVM Based Approach for the Analysis Of Mammography Images

    NASA Astrophysics Data System (ADS)

    Gan, X.; Kapsokalivas, L.; Skaliotis, A.; Steinhöfel, K.; Tangaro, S.

    2007-09-01

    Mammography is among the most popular imaging techniques used in the diagnosis of breast cancer. Nevertheless distinguishing between healthy and ill images is hard even for an experienced radiologist, because a single image usually includes several regions of interest (ROIs). The hardness of this classification problem along with the substantial amount of data, gathered from patients' medical history, motivates the use of a machine learning approach as part of a CAD (Computer Aided Detection) tool, aiming to assist radiologists in the characterization of mammography images. Specifically, our approach involves: i) the ROI extraction, ii) the Feature Vector extraction, iii) the Support Vector Machine (SVM) classification of ROIs and iv) the characterization of the whole image. We evaluate the performance of our approach in terms of the SVM's training and testing error and in terms of ROI specificity—sensitivity. The results show a relation between the number of features used and the SVM's performance.

  19. How should we interpret noncompliance with screening mammography?

    PubMed Central

    Bryant, H

    1996-01-01

    Primary care practitioners have an important role to play in recommending breast cancer screening to patients in the target age group. In this issue of CMAJ (see pages 1335 to 1343) Dr. Marie-Dominique Beaulieu and associates report the results of a program designed to maximize utilization of screening mammography. Only two thirds of eligible women for whom screening mammography was prescribed obtained a mammogram within the 2-month study period. However, when taken in context, this compliance rate is fairly encouraging. There are many possible reasons for noncompliance such as a need for more information or for repeated suggestions. Family physicians should not become disheartened in their efforts to increase the use of screening procedures and may find that collaboration with others in giving consistent messages will help to maximize screening rates within their patient population. PMID:8616738

  20. Screening Ultrasound in Women with Negative Mammography: Outcome Analysis

    PubMed Central

    Hwang, Ji-Young; Ko, Eun Young; Shin, Jung Hee; Hahn, Soo Yeon; Nam, Mee Young

    2015-01-01

    Purpose To show the results of an audit of screening breast ultrasound (US) in women with negative mammography in a single institution and to analyze US-detected cancers within a year and interval cancers. Materials and Methods During the year of 2006, 1974 women with negative mammography were screened with US in our screening center, and 1727 among them had pathologic results or any follow up breast examinations more than a year. We analyzed the distribution of Breast Imaging Reporting and Data System (BI-RADS) category and the performance outcome through follow up. Results Among 1727 women (age, 30-76 years, median 49.5 years), 1349 women (78.1%) showed dense breasts on mammography, 762 (44.1%) had previous breast US, and 25 women (1.4%) had a personal history of breast cancers. Test negatives were 94.2% (1.627/1727) [BI-RADS category 1 in 885 (51.2%), 2 in 742 (43.0%)]. The recall rate (=BI-RADS category 3, 4, 5) was 5.8%. Eight cancers were additionally detected with US (yield, 4.6 per 1000). The sensitivity, specificity, and positive predictive value (PPV1, PPV2) were 88.9%, 94.6%, 8.0%, and 28.0%, respectively. Eight of nine true positive cancers were stage I or in-situ cancers. One interval cancer was stage I cancer from BI-RADS category 2. Conclusion Screening US detected 4.6 additional cancers among 1000. The recall rate was 5.8%, which is in lower bound of acceptable range of mammography (5-12%), according to American College of Radiology standard. PMID:26256979

  1. Patient Care, Communication, and Safety in the Mammography Suite.

    PubMed

    Arnold, Leisa

    2016-09-01

    Producing high-quality mammograms requires excellent technical skills along with exemplary communication. Mammographers must be able to address differences in patients' mental states, body habitus, and physical ability to obtain an optimal examination. In addition, every mammographer must practice consistently with patient safety, care, and satisfaction in mind. This article discusses verbal and nonverbal communication strategies, barriers to communication, and the care and safety of patients in the mammography suite who present special challenges. PMID:27601710

  2. A task-based quality control metric for digital mammography.

    PubMed

    Bloomquist, A K Maki; Mainprize, J G; Mawdsley, G E; Yaffe, M J

    2014-11-01

    A reader study was conducted to tune the parameters of an observer model used to predict the detectability index (dʹ ) of test objects as a task-based quality control (QC) metric for digital mammography. A simple test phantom was imaged to measure the model parameters, namely, noise power spectrum,modulation transfer function and test-object contrast. These are then used ina non-prewhitening observer model, incorporating an eye-filter and internal noise, to predict dʹ. The model was tuned by measuring dʹ of discs in a four-alternative forced choice reader study. For each disc diameter, dʹ was used to estimate the threshold thicknesses for detectability. Data were obtained for six types of digital mammography systems using varying detector technologies and x-ray spectra. A strong correlation was found between measured and modeled values of dʹ, with Pearson correlation coefficient of 0.96. Repeated measurements from separate images of the test phantom show an average coefficient of variation in dʹ for different systems between 0.07 and 0.10. Standard deviations in the threshold thickness ranged between 0.001 and 0.017 mm. The model is robust and the results are relatively system independent, suggesting that observer model dʹ shows promise as a cross platform QC metric for digital mammography. PMID:25325670

  3. Behavioral Constructs and Mammography in Five Ethnic Groups

    PubMed Central

    Stewart, Susan L.; Rakowski, William; Pasick, Rena J.

    2010-01-01

    Intention, self-efficacy, perceived susceptibility, perceived benefits, and subjective norms are key constructs of health behavior theories; their predictive validity for cancer screening has not been ascertained in multiethnic populations. Participants were 1,463 African American, Chinese, Filipina, Latina, and White women aged 40 to 74 interviewed by telephone in their preferred languages. The relationship between base-line constructs and mammography 2 years later was assessed using multivariable logistic regression. Intention predicted mammography overall and among Whites (odds ratio [OR] = 5.0, 95% confidence interval [CI] = 2.4, 10), with racial/ethnic differences in association (p = .020). Self-efficacy predicted mammography overall and among Whites (OR = 3.5, 95% CI = 1.1, 11), with no racial/ethnic interaction. Perceived benefits and subjective norms were associated with screening overall and in some racial/ethnic groups. These results generally support cross-cultural applicability of four of the five constructs to screening with mixed predictive value of measures across racial/ethnic groups. Additional in-depth inquiry is required to refine assessment of constructs. PMID:19805790

  4. Toward a standard reference database for computer-aided mammography

    NASA Astrophysics Data System (ADS)

    Oliveira, Júlia E. E.; Gueld, Mark O.; de A. Araújo, Arnaldo; Ott, Bastian; Deserno, Thomas M.

    2008-03-01

    Because of the lack of mammography databases with a large amount of codified images and identified characteristics like pathology, type of breast tissue, and abnormality, there is a problem for the development of robust systems for computer-aided diagnosis. Integrated to the Image Retrieval in Medical Applications (IRMA) project, we present an available mammography database developed from the union of: The Mammographic Image Analysis Society Digital Mammogram Database (MIAS), The Digital Database for Screening Mammography (DDSM), the Lawrence Livermore National Laboratory (LLNL), and routine images from the Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen. Using the IRMA code, standardized coding of tissue type, tumor staging, and lesion description was developed according to the American College of Radiology (ACR) tissue codes and the ACR breast imaging reporting and data system (BI-RADS). The import was done automatically using scripts for image download, file format conversion, file name, web page and information file browsing. Disregarding the resolution, this resulted in a total of 10,509 reference images, and 6,767 images are associated with an IRMA contour information feature file. In accordance to the respective license agreements, the database will be made freely available for research purposes, and may be used for image based evaluation campaigns such as the Cross Language Evaluation Forum (CLEF). We have also shown that it can be extended easily with further cases imported from a picture archiving and communication system (PACS).

  5. Ultra-Fast Image Reconstruction of Tomosynthesis Mammography Using GPU

    PubMed Central

    Arefan, D.; Talebpour, A.; Ahmadinejhad, N.; Kamali Asl, A.

    2015-01-01

    Digital Breast Tomosynthesis (DBT) is a technology that creates three dimensional (3D) images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study ultra-fast image reconstruction technique for Tomosynthesis Mammography systems using Graphics Processing Unit (GPU). At first, projections of Tomosynthesis mammography have been simulated. In order to produce Tomosynthesis projections, it has been designed a 3D breast phantom from empirical data. It is based on MRI data in its natural form. Then, projections have been created from 3D breast phantom. The image reconstruction algorithm based on FBP was programmed with C++ language in two methods using central processing unit (CPU) card and the Graphics Processing Unit (GPU). It calculated the time of image reconstruction in two kinds of programming (using CPU and GPU). PMID:26171373

  6. Quality control programme in mammography: second level quality controls.

    PubMed

    Nassivera, E; Nardin, L

    1997-06-01

    Mammography is the most reliable method by which to detect lesions in the breast. Since contrast between normal and pathological areas in the breast is extremely low, mammographic image quality should reach high standards without exceeding acceptable exposure levels for the breast. A quality control programme in mammography has been implemented. This programme is subdivided into two levels. The first consists of simple daily checks of image quality and film processing, while the second deals with more complex checks of mammographic unit, screen-film system, darkroom, illuminators, viewing conditions and reference dose determination. The values of all the parameters undergoing measurement are compared with the limiting values given by National and International Protocols. This paper describes the second level controls carried out every 6 months by the medical physicist. The parameters described are only those which have been studied and analysed in detail since the quality control programme in mammography was implemented. Such parameters (kilovoltage, focal spot dimension, half value layer, tube output, automatic exposure control system, screen-film characteristic curve and mean glandular dose) were measured during the period 1991-1995 and the results summarised. The values obtained prove the constant correct functioning of the equipment. PMID:9227255

  7. Image and Dose Simulation in Support of New Mammography Modalities

    SciTech Connect

    Kuruvilla Verghese

    2002-04-05

    This report summarizes the highlights of the research performed under the 2-year NEER grant from the Department of Energy. The primary outcome of the work was a new Monte Carlo code, MCMIS-DS, for Monte Carlo for Mammography Image Simulation including Differential Sampling. The code was written to generate simulated images and dose distributions from two different new digital x-ray imaging modalities, namely, synchrotron imaging (SI) and a slot geometry digital mammography system called Fisher Senoscan. A differential sampling scheme was added to the code to generate multiple images that included variations in the parameters of the measurement system and the object in a single execution of the code. The code is to serve multiple purposes; (1) to answer questions regarding the contribution of scattered photons to images, (2) for use in design optimization studies, and (3) to do up to second-order perturbation studies to assess the effects of design parameter variations and/or physical parameters of the object (the breast) without having to re-run the code for each set of varied parameters. The accuracy and fidelity of the code were validated by a large variety of benchmark studies using published data and also using experimental results from mammography phantoms on both imaging modalities.

  8. Spectral lesion characterization on a photon-counting mammography system

    NASA Astrophysics Data System (ADS)

    Erhard, Klaus; Fredenberg, Erik; Homann, Hanno; Roessl, Ewald

    2014-03-01

    Spectral X-ray imaging allows to differentiate between two given tissue types, provided their spectral absorption characteristics differ measurably. In mammography, this method is used clinically to determine a decomposition of the breast into adipose and glandular tissue compartments, from which the glandular tissue fraction and, hence, the volumetric breast density (VBD) can be computed. Another potential application of this technique is the characterization of lesions by spectral mammography. In particular, round lesions are relatively easily detected by experienced radiologists, but are often difficult to characterize. Here, a method is described that aims at discriminating cystic from solid lesions directly on a spectral mammogram, obtained with a calibrated spectral mammography system and using a hypothesis-testing algorithm based on a maximum likelihood approach. The method includes a parametric model describing the lesion shape, compression height variations and breast composition. With the maximum likelihood algorithm, the model parameters are estimated separately under the cyst and solid hypothesis. The resulting ratio of the maximum likelihood values is used for the final tissue characterization. Initial results using simulations and phantom measurements are presented.

  9. The acceptance and completion of mammography by older black women.

    PubMed Central

    Burack, R C; Liang, J

    1989-01-01

    We assessed the relation of patient characteristics, knowledge and beliefs to the utilization of mammography in an inner-city setting by 187 Black women over the age of 50. Thirty per cent of those who were offered mammography initially declined the offer and 40 per cent were subsequently unable to complete the procedure. Patient interviews were used to derive 27 potential knowledge and health belief predictor scales. In multiple regression analysis, two health belief scales and two knowledge scales accounted for 15 per cent of the observed variance in the model of acceptance. The strongest predictor of subsequent completion was initial acceptance. The presence of breast symptoms and two health belief scales together with initial acceptance accounted for 26 per cent of variance in the model of completion. These results suggest that the successful accomplishment of mammography requires coordinated efforts at the level of the provider, patient, and setting. Health beliefs may influence the patient's behavior in this process, but their effect appears to be modest. PMID:2729469

  10. Optimization of peak kilovoltage and spectral shape for digital mammography

    NASA Astrophysics Data System (ADS)

    Fahrig, Rebecca; Maidment, Andrew D. A.; Yaffe, Martin J.

    1992-06-01

    X-ray mammography is one of the most demanding radiological techniques, simultaneously requiring excellent image quality and low dose to the breast. In current mammographic practice, both image quality and dose are found to vary over a wide range of values. Previous attempts to define the optimum operating parameters for mammography systems have been limited due to the lack of realistic attenuation coefficients and absorbed dose data. These data are now available, and have been incorporated into an energy transport model which describes the image acquisition process. The model includes measured x-ray spectra and considers beam filtration, breast thickness and composition, lesion size and composition, scatter, grid transmission, and the production and propagation of light in a phosphor-based image receptor. The applied kilovoltage for molybdenum and tungsten target x-ray sources with various spectral filters and average breast composition (50% adipose, 50% fibroglandular) has been optimized with respect to signal-to-noise ratio and absorbed dose and was found to vary between 19 and 29 kVp as breast thickness increased from 4 to 8 cm. Preliminary results for various breast compositions and lesions, and experimental verification of the model are presented. The model may be extended to include either mammographic film or new detector designs for digital mammography.

  11. A task-based quality control metric for digital mammography

    NASA Astrophysics Data System (ADS)

    Maki Bloomquist, A. K.; Mainprize, J. G.; Mawdsley, G. E.; Yaffe, M. J.

    2014-11-01

    A reader study was conducted to tune the parameters of an observer model used to predict the detectability index (dʹ ) of test objects as a task-based quality control (QC) metric for digital mammography. A simple test phantom was imaged to measure the model parameters, namely, noise power spectrum, modulation transfer function and test-object contrast. These are then used in a non-prewhitening observer model, incorporating an eye-filter and internal noise, to predict dʹ. The model was tuned by measuring dʹ of discs in a four-alternative forced choice reader study. For each disc diameter, dʹ was used to estimate the threshold thicknesses for detectability. Data were obtained for six types of digital mammography systems using varying detector technologies and x-ray spectra. A strong correlation was found between measured and modeled values of dʹ, with Pearson correlation coefficient of 0.96. Repeated measurements from separate images of the test phantom show an average coefficient of variation in dʹ for different systems between 0.07 and 0.10. Standard deviations in the threshold thickness ranged between 0.001 and 0.017 mm. The model is robust and the results are relatively system independent, suggesting that observer model dʹ shows promise as a cross platform QC metric for digital mammography.

  12. Characteristics of YouTube™ Videos Related to Mammography.

    PubMed

    Basch, Corey H; Hillyer, Grace Clarke; MacDonald, Zerlina L; Reeves, Rachel; Basch, Charles E

    2015-12-01

    With a monthly total of more than one billion unique visitors, YouTube™ is one of the Internet's most visited websites and contributes to the growing amount of health-related information on the Internet. The purpose of this study was to analyze coverage of mammography screening in popular YouTube™ videos. A total of 173 videos were included in the analysis. Compared with professionally created videos, consumer-created videos had a significantly greater number of comments (>9 comments 38.0% for consumer vs. 11.8% for professional videos, p=<0.001). Videos created by professionals more often portrayed general mammography information (97.1 vs. 88.7%) compared to those created by consumers. The vast majority of videos presented general information (93.6%) related to mammography, and almost two thirds addressed preparing for the test. Less than 20% dealt with other types of examinations. Approximately 30% discussed pain associated with the examination (35.3%) and addressed issues of anxiety (32.4%) and fear (29.5%). Nearly half of the videos presented information about the test results (46.2%). Over 25% covered medical or family history. The majority did not pertain to a specific age group. Future research should focus on analyzing the accuracy of the information in the videos. PMID:25502853

  13. Ultra-Fast Image Reconstruction of Tomosynthesis Mammography Using GPU.

    PubMed

    Arefan, D; Talebpour, A; Ahmadinejhad, N; Kamali Asl, A

    2015-06-01

    Digital Breast Tomosynthesis (DBT) is a technology that creates three dimensional (3D) images of breast tissue. Tomosynthesis mammography detects lesions that are not detectable with other imaging systems. If image reconstruction time is in the order of seconds, we can use Tomosynthesis systems to perform Tomosynthesis-guided Interventional procedures. This research has been designed to study ultra-fast image reconstruction technique for Tomosynthesis Mammography systems using Graphics Processing Unit (GPU). At first, projections of Tomosynthesis mammography have been simulated. In order to produce Tomosynthesis projections, it has been designed a 3D breast phantom from empirical data. It is based on MRI data in its natural form. Then, projections have been created from 3D breast phantom. The image reconstruction algorithm based on FBP was programmed with C++ language in two methods using central processing unit (CPU) card and the Graphics Processing Unit (GPU). It calculated the time of image reconstruction in two kinds of programming (using CPU and GPU). PMID:26171373

  14. Assessment of fetal malformations in the first trimester of pregnancy by three-dimensional ultrasonography in the rendering mode. Pictorial essay.

    PubMed

    Araujo Júnior, Edward; Rolo, Liliam Cristine; Tonni, Gabriele; Haeri, Sina; Ruano, Rodrigo

    2015-03-01

    We present our experience in the contribution of three-dimensional ultrasonography, using the rendering mode, to the prenatal diagnosis of congenital anomalies including neurological defects (acrania/anencephaly, encephalocele, holoprosencephaly), facial anomalies (cyclopia and facial clefts), abdominal wall defects (omphalocele and gastroschisis) and defects of extremities (fetal muscle-skeletal dysplasias). Three-dimensional ultrasonography may contribute to improve the prenatal diagnosis with further revision of the fetal images, allowing a better prenatal counsel to the parents. PMID:25745664

  15. MR imaging of urinary bladder cancer for T-staging: a review and a pictorial essay of diffusion-weighted imaging.

    PubMed

    Takeuchi, Mitsuru; Sasaki, Shigeru; Naiki, Taku; Kawai, Noriyasu; Kohri, Kenjiro; Hara, Masaki; Shibamoto, Yuta

    2013-12-01

    Treatment decisions for bladder cancer patients are mainly based on the depth of bladder wall invasion by the tumor. In this article, we review the conventional MRI and exhibit a recently emerged diffusion-weighted imaging (DWI) of urinary bladder cancer for T-staging. We discuss limitations of conventional MRI, scanning protocols of DWI, normal pelvic findings on DWI, determination of T-stage using DWI, and pitfalls of DWI. DWI provides high contrast between bladder cancer and background tissue because the cancer shows markedly high SI. DWI has high sensitivity for detecting the stalk seen in stage Ta or T1. An inflammatory change or fibrosis surrounding the tumor mimics the invasion of bladder cancer on T2-weighted imaging or enhanced MRI and could lead to over-staging, but DWI could differentiate them clearly because these benign changes do not show high SI on DWI. DWI is also useful for detecting ureteral, urethral, and prostatic extension by means of the urethra. DWI provides more accurate information on the extent of bladder cancer and contributes to determination of the treatment strategy. PMID:24265260

  16. Comparison of slot scanning digital mammography system with full-field digital mammography system

    SciTech Connect

    Lai, C.-J.; Shaw, Chris C.; Geiser, William; Chen, Lingyun; Arribas, Elsa; Stephens, Tanya; Davis, Paul L.; Ayyar, Geetha P.; Dogan, Basak E.; Nguyen, Victoria A.; Whitman, Gary J.; Yang, Wei T.

    2008-06-15

    The purpose of this study was to evaluate and compare microcalcification detectability of two commercial full-field digital mammography (DM) systems. The first unit was a flat panel based DM system (FFDM) which employed an anti-scatter grid method to reject scatter, and the second unit was a charge-coupled device-based DM system (SSDM) which used scanning slot imaging geometry to reduce scatter radiation. Both systems have comparable scatter-to-primary ratios. In this study, 125-160 and 200-250 {mu}m calcium carbonate grains were used to simulate microcalcifications and imaged by both DM systems. The calcium carbonate grains were overlapped with a 5-cm-thick 50% adipose/50% glandular simulated breast tissue slab and an anthropomorphic breast phantom (RMI 165, Gammex) for imaging at two different mean glandular dose levels: 0.87 and 1.74 mGy. A reading study was conducted with seven board certified mammographers with images displayed on review workstations. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (A{sub z}) was used to quantify and compare the performances of these two systems. The results showed that with the simulated breast tissue slab (uniform background), the SSDM system resulted in higher A{sub z}'s than the FFDM system at both MGD levels with the difference statistically significant at 0.87 mGy only. With the anthropomorphic breast phantom (tissue structure background), the SSDM system performed better than the FFDM system at 0.87 mGy but worse at 1.74 mGy. However, the differences were not found to be statistically significant.

  17. Comparison of slot scanning digital mammography system with full-field digital mammography system

    PubMed Central

    Lai, Chao-Jen; Shaw, Chris C.; Geiser, William; Chen, Lingyun; Arribas, Elsa; Stephens, Tanya; Davis, Paul L.; Ayyar, Geetha P.; Dogan, Basak E.; Nguyen, Victoria A.; Whitman, Gary J.; Yang, Wei T.

    2008-01-01

    The purpose of this study was to evaluate and compare microcalcification detectability of two commercial full-field digital mammography (DM) systems. The first unit was a flat panel based DM system (FFDM) which employed an anti-scatter grid method to reject scatter, and the second unit was a charge-coupled device-based DM system (SSDM) which used scanning slot imaging geometry to reduce scatter radiation. Both systems have comparable scatter-to-primary ratios. In this study, 125–160 and 200–250 μm calcium carbonate grains were used to simulate microcalcifications and imaged by both DM systems. The calcium carbonate grains were overlapped with a 5-cm-thick 50% adipose∕50% glandular simulated breast tissue slab and an anthropomorphic breast phantom (RMI 165, Gammex) for imaging at two different mean glandular dose levels: 0.87 and 1.74 mGy. A reading study was conducted with seven board certified mammographers with images displayed on review workstations. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed and the area under the ROC curve (Az) was used to quantify and compare the performances of these two systems. The results showed that with the simulated breast tissue slab (uniform background), the SSDM system resulted in higher Az’s than the FFDM system at both MGD levels with the difference statistically significant at 0.87 mGy only. With the anthropomorphic breast phantom (tissue structure background), the SSDM system performed better than the FFDM system at 0.87 mGy but worse at 1.74 mGy. However, the differences were not found to be statistically significant. PMID:18649467

  18. Solid-state dosimeters: A new approach for mammography measurements

    SciTech Connect

    Brateman, Libby F.; Heintz, Philip H.

    2015-02-15

    Purpose: To compare responses of modern commercially available solid-state dosimeters (SStDs) used in mammography medical physics surveys for two major vendors of current digital mammography units. To compare differences in dose estimates among SStD responses with ionization chamber (IC) measurements for several target/filter (TF) combinations and report their characteristics. To review scientific bases for measurements of quantities required for mammography for traditional measurement procedures and SStDs. Methods: SStDs designed for use with modern digital mammography units were acquired for evaluation from four manufacturers. Each instrument was evaluated under similar conditions with the available mammography beams provided by two modern full-field digital mammography units in clinical use: a GE Healthcare Senographe Essential (Essential) and a Hologic Selenia Dimensions 5000 (Dimensions), with TFs of Mo/Mo, Mo/Rh; and Rh/Rh and W/Rh, W/Ag, and W/Al, respectively. Measurements were compared among the instruments for the TFs over their respective clinical ranges of peak tube potentials for kVp and half-value layer (HVL) measurements. Comparisons for air kerma (AK) and their associated relative calculated average glandular doses (AGDs), i.e., using fixed mAs, were evaluated over the limited range of 28–30 kVp. Measurements were compared with reference IC measurements for AK, reference HVLs and calculated AGD, for two compression paddle heights for AK, to evaluate scatter effects from compression paddles. SStDs may require different positioning from current mammography measurement protocols. Results: Measurements of kVp were accurate in general for the SStDs (within −1.2 and +1.1 kVp) for all instruments over a wide range of set kVp’s and TFs and most accurate for Mo/Mo and W/Rh. Discrepancies between measurements and reference values were greater for HVL and AK. Measured HVL values differed from reference values by −6.5% to +3.5% depending on the SStD and

  19. Essays concerning the cellulosic biofuel industry

    NASA Astrophysics Data System (ADS)

    Rosburg, Alicia Sue

    Despite market-based incentives and mandated production, the U.S. cellulosic biofuel industry has been slow to develop. This dissertation explores the economic factors that have limited industry development along with important economic tradeoffs that will be encountered with commercial-scale production. The first essay provides an overview of the policies, potential, and challenges of the biofuel industry, with a focus on cellulosic biofuel. The second essay considers the economics of cellulosic biofuel production. Breakeven models of the local feedstock supply system and biofuel refining process are constructed to develop the Biofuel Breakeven (BioBreak) program, a stochastic, Excel-based program that evaluates the feasibility of local biofuel and biomass markets under various policy and market scenarios. An application of the BioBreak program is presented using expected market conditions for 14 local cellulosic biofuel markets that vary by feedstock and location. The economic costs of biofuel production identified from the BioBreak application are higher than frequently anticipated and raise questions about the potential of cellulosic ethanol as a sustainable and economical substitute for conventional fuels. Program results also are extended using life-cycle analysis to evaluate the cost of reducing GHG emissions by substituting cellulosic ethanol for conventional fuel. The third essay takes a closer look at the economic trade-offs within the biorefinery industry and feedstock production processes. A long-run biomass production through bioenergy conversion cost model is developed that incorporates heterogeneity of biomass suppliers within and between local markets. The model builds on previous literature by treating biomass as a non-commoditized feedstock and relaxes the common assumption of fixed biomass density and price within local markets. An empirical application is provided for switchgrass-based ethanol production within U.S. crop reporting districts

  20. Essays on regulation, institutions, and industrial organization

    NASA Astrophysics Data System (ADS)

    Bergara, Mario Esteban

    Essay I develops a comparative institutional analysis of network access price regulation and "light-handed" regulation. While the former is a specific-agency-based arrangement with higher political influence, the latter is a court-based system. Consequently, the main trade-off between both frameworks reflects the merits of having efficient political and judicial institutions. Price regulation is superior when distributional concerns are irrelevant and information asymmetries are lower. Poorly functioning political systems and high welfare costs of raising funds make price regulation less attractive. Light regulation is more attractive when potential rents are smaller, the monopolist is more risk averse, the judicial system is more efficient, and the threat of government intervention is more credible. The possibility of private transfers makes price regulation more advantageous. Higher information asymmetries among firms makes light-handed regulation more attractive. The main results are consistent with a plausible interpretation of the drastic deregulatory process in New Zealand. Essay II studies the preliminary effects of the deregulation of direct access in the New Zealand's electricity market. A slight improvement in quality standards and an overall efficiency increase took place after two years of deregulation. Retailers were able to successfully enter in large demand, dense areas, with a large proportion of industrial and commercial users, where incumbents were not distributing electricity efficiently. Pricing policies appears to be influenced by market forces (associated to economic and demographic characteristics) as expected in a light regulatory framework. Essay III focuses on the possibility of endogenous sunk costs and the introduction of new products. Firms that exert some monopoly power in one market and introduce a new good whose demand is determined by a broader set of consumers might be forced to change their competing strategies. If the new product

  1. Essays in energy economics: The electricity industry

    NASA Astrophysics Data System (ADS)

    Martinez-Chombo, Eduardo

    Electricity demand analysis using cointegration and error-correction models with time varying parameters: The Mexican case. In this essay we show how some flexibility can be allowed in modeling the parameters of the electricity demand function by employing the time varying coefficient (TVC) cointegrating model developed by Park and Hahn (1999). With the income elasticity of electricity demand modeled as a TVC, we perform tests to examine the adequacy of the proposed model against the cointegrating regression with fixed coefficients, as well as against the spuriousness of the regression with TVC. The results reject the specification of the model with fixed coefficients and favor the proposed model. We also show how some flexibility is gained in the specification of the error correction model based on the proposed TVC cointegrating model, by including more lags of the error correction term as predetermined variables. Finally, we present the results of some out-of-sample forecast comparison among competing models. Electricity demand and supply in Mexico. In this essay we present a simplified model of the Mexican electricity transmission network. We use the model to approximate the marginal cost of supplying electricity to consumers in different locations and at different times of the year. We examine how costs and system operations will be affected by proposed investments in generation and transmission capacity given a forecast of growth in regional electricity demands. Decomposing electricity prices with jumps. In this essay we propose a model that decomposes electricity prices into two independent stochastic processes: one that represents the "normal" pattern of electricity prices and the other that captures temporary shocks, or "jumps", with non-lasting effects in the market. Each contains specific mean reverting parameters to estimate. In order to identify such components we specify a state-space model with regime switching. Using Kim's (1994) filtering algorithm

  2. ON THE MISALIGNMENT OF THE DIRECTLY IMAGED PLANET {beta} PICTORIS b WITH THE SYSTEM'S WARPED INNER DISK

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Fabrycky, Daniel C.

    2011-12-10

    The vertical warp in the debris disk {beta} Pictoris-an inclined inner disk extending into a flat outer disk-has long been interpreted as the signpost of a planet on an inclined orbit. Direct images spanning 2004-2010 have revealed {beta} Pictoris b, a planet with a mass and orbital distance consistent with this picture. However, it was recently reported that the orbit of planet b is aligned with the flat outer disk, not the inclined inner disk, and thus lacks the inclination to warp the disk. We explore three scenarios for reconciling the apparent misalignment of the directly imaged planet {beta} Pictoris b with the warped inner disk of {beta} Pictoris: observational uncertainty, an additional planet, and damping of planet b's inclination. We find that, at the extremes of the uncertainties, the orbit of {beta} Pictoris b has the inclination necessary to produce the observed warp. We also find that if planet b were aligned with the flat outer disk, it would prevent another planet from creating a warp with the observed properties; therefore planet b itself must be responsible for the warp. Finally, planet b's inclination could have been damped by dynamical friction and still produce the observed disk morphology, but the feasibility of damping depends on disk properties and the presence of other planets. More precise observations of the orbit of planet b and the position angle of the outer disk will allow us to distinguish between the first and third scenarios.

  3. Workplace Literacy. Essays from the Model Literacy Project.

    ERIC Educational Resources Information Center

    Holzman, Michael, Ed.; Connolly, Olga, Ed.

    The 20 essays in this collection are based on a project undertaken by the California Conservation Corps (CCC) and the Model Literacy Project in 1983-85. (The goal of the project was to institute changes within the CCC to enhance the literacy of corpsmembers.) Essays describe innovative approaches to literacy education, analyze bureaucratic…

  4. Meet the 2008 Cliff Weiss Memorial Essay Contest Winners

    ERIC Educational Resources Information Center

    Techniques: Connecting Education and Careers (J3), 2008

    2008-01-01

    This article presents the winners of the 2008 Cliff Weiss Memorial Essay Contest and their winning essays. The winners are Spencer Terry of Tulsa, Oklahoma (secondary), and Carrie Snyder-Renfro of Oklahoma City, Oklahoma (postsecondary). The topic for secondary students is "How would you communicate the impact and importance of CTE related to your…

  5. History.edu: Essays on Teaching with Technology.

    ERIC Educational Resources Information Center

    Trinkle, Dennis A., Ed.; Merriman, Scott A., Ed.

    Intended to be equally useful to high school and college instructors, this book contains studies in history pedagogy, among them the first three published essays measuring qualitatively and quantitatively the successes and failures of "e-teaching" and distance learning. Collectively, the essays urge instructors to take the next step with computing…

  6. Performance, Feedback, and Revision: Metacognitive Approaches to Undergraduate Essay Writing

    ERIC Educational Resources Information Center

    Riddell, Jessica

    2015-01-01

    This paper explores ways in which frequent feedback and clear assessment criteria can improve students' essay writing performance in a first-year English literature course. Students (n = 68) completed a series of three scaffolded exercises over the course of a semester, where they evaluated undergraduate essays using a predetermined assessment…

  7. The Essay Test: A Look at the Advantages and Disadvantages.

    ERIC Educational Resources Information Center

    Tuckman, Bruce W.

    1993-01-01

    Essay tests are easily constructed, relatively valid assessments of higher cognitive processes but are harder to score reliably. Teachers using essay tests are advised to follow clearly designed objectives, construct all-inclusive, pilot-tested questions, develop a checklist of specific scoring points and a model answer for each question, and use…

  8. How Important Is Content in the Ratings of Essay Assessments?

    ERIC Educational Resources Information Center

    Shermis, Mark D.; Shneyderman, Aleksandr; Attali, Yigal

    2008-01-01

    This study was designed to examine the extent to which "content" accounts for variance in scores assigned in automated essay scoring protocols. Specifically it was hypothesised that certain writing genre would emphasise content more than others. Data were drawn from 1668 essays calibrated at two grade levels (6 and 8) using "e-rater[TM]", an…

  9. Automated Essay Scoring With e-rater[R] V.2

    ERIC Educational Resources Information Center

    Attali, Yigal; Burstein, Jill

    2006-01-01

    E-rater[R] has been used by the Educational Testing Service for automated essay scoring since 1999. This paper describes a new version of e-rater (V.2) that is different from other automated essay scoring systems in several important respects. The main innovations of e-rater V.2 are a small, intuitive, and meaningful set of features used for…

  10. Relevancy in Vocational Education (A Collection of Essays).

    ERIC Educational Resources Information Center

    Ediger, Marlow

    This collection of seven essays covers the subject of relevance in vocational education from several perspectives. Topics of the essays are the following: (1) vocational education and the curriculum; (2) the counselor and vocational education; (3) vocational education and employability skills; (4) student reentry into the curriculum; (5) remedying…

  11. Factor Structure of the MCAT and Pilot Essay.

    ERIC Educational Resources Information Center

    Mitchell, Karen J.; Molidor, John B.

    1986-01-01

    Research reported in this paper considered the construct validity of a trial essay administered in 1985-87 Medical College Admission Test (MCAT). The addition of the essay caused the non-science factor observed in previous MCAT research to be more strongly defined. (Author/LMO)

  12. Missing: Electronic Feedback in Egyptian EFL Essay Writing Classes

    ERIC Educational Resources Information Center

    Seliem, Soheir; Ahmed, Abdelhamid

    2009-01-01

    EFL essay writing is considered one of the most important academic courses in the teacher education programmes that should help develop students' skills to write cohesively and coherently. Teachers' feedback plays a crucial role in improving and enhancing the quality of students' written essays. The aim of the current study was to shed light on…

  13. Two-Year College English: Essays for a New Century.

    ERIC Educational Resources Information Center

    Reynolds, Mark, Ed.

    Noting that the nearly 1,400 two-year colleges in the United States enroll almost half of all students in higher education, this collection of essays discusses the students, the curriculum, and the faculty at these colleges. In essence, the collection surveys what is "on the minds" of two-year college English teachers. The essays and their authors…

  14. Automatically Scoring Short Essays for Content. CRESST Report 836

    ERIC Educational Resources Information Center

    Kerr, Deirdre; Mousavi, Hamid; Iseli, Markus R.

    2013-01-01

    The Common Core assessments emphasize short essay constructed response items over multiple choice items because they are more precise measures of understanding. However, such items are too costly and time consuming to be used in national assessments unless a way is found to score them automatically. Current automatic essay scoring techniques are…

  15. From Journals to Essays: Reading, Writing, Re-Thinking.

    ERIC Educational Resources Information Center

    Cook, Devan

    1996-01-01

    Discusses the difficulty involved in moving from writing a journal entry toward writing an essay. Uses the background of a trip to Ireland and writing an "Irish" journal as an example. Gives four strategies to use from journal to essay: double-entry notebook, defamiliarization (or "persona switching") techniques, cross-genre writing, and allowing…

  16. Teaching Composition: Twelve Bibliographical Essays. Revised and Enlarged Edition.

    ERIC Educational Resources Information Center

    Tate, Gary, Ed.

    Intended for teachers of composition courses, this book provides twelve bibliographic essays covering various aspects of composition studies. The list of essays are as follows: (1) "Recent Developments in Rhetorical Invention" (Richard Young); (2) "Structure and Form in Non-Narrative Prose" (Richard L. Larson); (3) "Approaches to the Study of…

  17. Reliability of Holistic Scoring for the 1985 MCAT Essays.

    ERIC Educational Resources Information Center

    Mitchell, Karen J.; Anderson, Judith A.

    A pilot essay was included in the 1985 Spring and Fall administrations of the Medical College Admission Test. A sample of 320 of the essays written by Fall examinees who had expressed an interest in allopathic medicine was used to calculate interrater reliability estimates. Sixteen of 20 readers who had been trained by White's suggestions for…

  18. A Crosscultural Analysis of Argumentative Strategies in Student Essays.

    ERIC Educational Resources Information Center

    Kamimura, Taeko; Oi, Kyoko

    A study of essays on a single topic (capital punishment) written by 22 American high school students and 30 second-year Japanese college students investigated: cultural differences in organizational patterns in argumentative essays; comparative use of rational and affective appeals; differences in content of rational and affective appeals;…

  19. Performance of a Generic Approach in Automated Essay Scoring

    ERIC Educational Resources Information Center

    Attali, Yigal; Bridgeman, Brent; Trapani, Catherine

    2010-01-01

    A generic approach in automated essay scoring produces scores that have the same meaning across all prompts, existing or new, of a writing assessment. This is accomplished by using a single set of linguistic indicators (or features), a consistent way of combining and weighting these features into essay scores, and a focus on features that are not…

  20. The Great Excluded: Critical Essays on Children's Literature. Volume One.

    ERIC Educational Resources Information Center

    Butler, Francelia, Ed.

    This collection of essays is intended to stimulate writing, teaching, and study of children's literature by humanists. Among the essays are: "Aesop as Litmus: The Acid Test of Children's Literature,""Children's Literature in Old English,""Children's Literature in the Middle Ages,""Pilgrim's Progress as Fairy Tale,""Out of the Ordinary Road: Locke…