Early diagnosis of acoustic neuroma by quantitative neurootological and neuroradiological tests

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Haid, C T

1983-02-01

Every patient with unilateral and sensoneural loss of hearing, independent of vertigo anamnesis or X-rays must be further examined by a vestibular test. Between 1974 and 1980, 80 acoustic neuromas could be diagnosed, including 12 early stage neuromas. This relatively high detection quote of small neuromas is due to a special diagnostical program: All 80 patients with acoustic neuroma had a pathological vestibular result. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the caloric test: 95% of the patients with a neurinoma showed a pathological result in the positional test. So every patient suffering from an unidentified unilateral and sensoneural hearing loss combined with a pathological result in the positional test must be further examined by a cisternomeatography or computerized tomography (using air-insufflation). Every fifth of these patients showed unique hints of an acoustic neuroma in the neuroradiological test.

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[Treatment of painful neuromas via end-to-side neurorraphy].

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Aszmann, O C; Moser, V; Frey, M

2010-08-01

Management of the painful neuroma has been subject to controversy since the earliest descriptions of this disabling problem. Today, treatment is limited to resection of the neuroma and implantation of the nerve in a muscle at a location where it is safe from irritation and trauma. This however is not attainable in many cases and it is our clinical experience, that nerves without a target remain a source of constant discomfort and pain. Recently we reported of the feasibility of neuroma prevention through end-to-side neurorraphy into adjacent sensory and/or motor nerves to provide a target for axons deprived of their endorgan. Here we report of our first clinical experience with this method in sixteen patients with longstanding upper and lower extremity neuromas. 16 patients were included in this study. All had neuromas of different sensory nerves of both the upper and lower extremity. 11 were of iatrogenic origin, 5 were caused by different traumas. 8 had previous attempts to surgically treat the neuroma. Finally, all were treated by end-to-side neurorraphy into adjacent nerves. Postoperatively quantitative sensorymotor testing was performed to evaluate possible changes of nerve function of the recipient nerves. Pain was evaluated by visual analogue score and changes in pain medication. In no patient a sensory or motor deficit or painful sensations were induced in the target area of the recipient nerve. Some had dysaesthesias for about 6 months, which finally subsided. All but 1 patient improved in their symptoms at a follow-up of more than 2 years. Previous experimental work and present clinical results suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented without inducing sensory or motor dysfunctions in the recipient nerve. Georg Thieme Verlag KG Stuttgart New York.

A quantitative evaluation of gross versus histologic neuroma formation in a rabbit forelimb amputation model: potential implications for the operative treatment and study of neuromas

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Kuiken Todd A

2011-10-01

Full Text Available Abstract Background Surgical treatment of neuromas involves excision of neuromas proximally to the level of grossly "normal" fascicles; however, proximal changes at the axonal level may have both functional and therapeutic implications with regard to amputated nerves. In order to better understand the retrograde "zone of injury" that occurs after nerve transection, we investigated the gross and histologic changes in transected nerves using a rabbit forelimb amputation model. Methods Four New Zealand White rabbits underwent a forelimb amputation with transection and preservation of the median, radial, and ulnar nerves. After 8 weeks, serial sections of the amputated nerves were then obtained in a distal-to-proximal direction toward the brachial plexus. Quantitative histomorphometric analysis was performed on all nerve specimens. Results All nerves demonstrated statistically significant increases in nerve cross-sectional area between treatment and control limbs at the distal nerve end, but these differences were not observed 10 mm more proximal to the neuroma bulb. At the axonal level, an increased number of myelinated fibers were seen at the distal end of all amputated nerves. The number of myelinated fibers progressively decreased in proximal sections, normalizing at 15 mm proximally, or the level of the brachial plexus. The cross-sectional area of myelinated fibers was significantly decreased in all sections of the treatment nerves, indicating that atrophic axonal changes proceed proximally at least to the level of the brachial plexus. Conclusions Morphologic changes at the axonal level extend beyond the region of gross neuroma formation in a distal-to-proximal fashion after nerve transection. This discrepancy between gross and histologic neuromas signifies the need for improved standardization among neuroma models, while also providing a fresh perspective on how we should view neuromas during peripheral nerve surgery.

[Clinical and radiological evolution of a group of untreated acoustic neuromas].

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Escorihuela-García, Vicente; Llópez-Carratalá, Ignacio; Orts-Alborch, Miguel; Marco-Algarra, Jaime

2014-01-01

The acoustic neuroma is a benign tumour that originates in the vestibular branch of the eighth cranial nerve. The main treatment is surgery, but many authors suggest that with elderly patients or in small neuromas we can opt for watchful waiting. This was a retrospective study from 2007 to 2013 that included 27 patients diagnosed of acoustic neuroma that had not been treated due to the size of the tumour, age and comorbidities, or by patient choice. We evaluated overall condition, hearing thresholds, degree of canal paresis and central disorders. After 6 years of follow up, clinical manifestations of 18 patients remained unchanged, 5 patients underwent hearing loss and developed tinnitus, 2 cases had more intense tinnitus and 2 cases had dizziness. The radiological controls by magnetic resonance imaging showed that the initial maximum diameters (5-16mm) increased by 1.7mm on average, with annual growth rates below 0.5mm. In selected cases, such as for small neuromas and in elderly patients, the conservative option of close monitoring with magnetic resonance imaging is an important alternative given that, in our cases, clinical features and radiological image did not suffer major changes. If there were any such changes, therapeutic options could be proposed. Copyright © 2013 Elsevier España, S.L. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Ultrasound-Guided Hyaluronic Acid Injection for the Management of Morton's Neuroma.

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Lee, Kang; Hwang, Il-Yeong; Ryu, Chang Hyun; Lee, Jae Woo; Kang, Seung Woo

2018-02-01

Morton's neuroma is one of the common causes of forefoot pain. In the present study, hyaluronic acid injection was performed on patients to determine the efficacy and adverse effects of hyaluronic acid in management of Morton's neuroma. Eighty-three patients with Morton's neuroma in their third intermetatarsal space with definite Mulder's click were included in the study. Those with severe forefoot deformities such as forefoot cavus or hallux valgus on plain X-rays were excluded. Ultrasound-guided hyaluronic acid injections were performed on all patients weekly for 3 weeks. Pain during walking using visual analogue scale (VAS) and AOFAS Forefoot Scale were prospectively evaluated preinjection, and at 2, 4, 6, 12 months postinjection. Significant improvement in VAS and AOFAS Forefoot Scale were seen overall at 2 months after hyaluronic acid injections ( P hyaluronic injection was clinically effective for pain relief and functional improvement for at least 12 months in patients with Morton's neuroma. However, numbness associated with Morton's neuroma should be addressed more cautiously since it may persist without much improvement. Level IV, retrospective case series.

Bilateral acoustic neuromas.

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Anand, V T; Byrnes, D P; Walby, A P; Kerr, A G

1993-10-01

This article reviews 12 patients with bilateral acoustic neuromas. The sex incidence was equal and the mean age at diagnosis was 26.2 years. The family history was positive in nine of the patients. Five patients have had incomplete surgical removal of acoustic neuromas on both sides. Two of them are completely deaf and the other three have severe sensorineural hearing loss in one ear and no hearing in the other ear. In five patients the tumour on one side has been operated on and the other side is being observed with at least short-term preservation of good hearing. The remaining two patients died of intra-cranial complications, one of them post-operatively. Four patients developed facial palsy immediately following surgery and one developed facial weakness 6 months after surgery. Guidelines are discussed for the care of these patients including the timing of surgery and alternative treatment options (observation, radio-surgery and chemotherapy). This is essentially a group of young individuals who have had multiple operations for bilateral acoustic tumours and associated manifestations and for whom the disease and the sequelae of treatment can be tragic.

Ultrasonographic features of traumatic neuromas in breast cancer patients after mastectomy

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Sung, Hwa Sung; Kim, Young Seon [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

2017-01-15

The purpose of this study was to evaluate the ultrasonographic (US) features of traumatic neuromas in breast cancer patients after mastectomy. This study was performed with approval from our Institutional Review Board, and the requirement for informed consent was waived. Six traumatic neuromas in five patients were included in this study. The US findings of traumatic neuromas were evaluated retrospectively by two radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. The final assessment was also recorded. On US, all six lesions presented as a mass within the pectoralis muscle layer (mean size, 4.8 mm; range, 3.9 to 5.5 mm). Of the six masses, four had an oval shape with a circumscribed margin, and two had an irregular shape and an indistinct margin. They were all hypoechoic. Two lesions showed a non-parallel orientation. On color Doppler examinations, two lesions showed internal vascularity. Strain elastography was performed for four neuromas, resulting in scores of 1 (n=1), 4 (n=2), and 5 (n=1). The final assessment categories were BI-RADS 3 (n=2), 4A (n=2), and 4B (n=2). On US, an oval shape, circumscribed margin, parallel orientation, and hypoechogenicity were the most frequent features of traumatic neuromas in breast cancer patients after mastectomy. Neuromas may show increased vascularity on color Doppler imaging and present as a hard mass on elastography.

Ultrasonographic features of traumatic neuromas in breast cancer patients after mastectomy

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Hwa Sung Sung

2017-01-01

Full Text Available Purpose The purpose of this study was to evaluate the ultrasonographic (US features of traumatic neuromas in breast cancer patients after mastectomy. Methods This study was performed with approval from our Institutional Review Board, and the requirement for informed consent was waived. Six traumatic neuromas in five patients were included in this study. The US findings of traumatic neuromas were evaluated retrospectively by two radiologists according to the Breast Imaging-Reporting and Data System (BI-RADS lexicon. The final assessment was also recorded. Results On US, all six lesions presented as a mass within the pectoralis muscle layer (mean size, 4.8 mm; range, 3.9 to 5.5 mm. Of the six masses, four had an oval shape with a circumscribed margin, and two had an irregular shape and an indistinct margin. They were all hypoechoic. Two lesions showed a non-parallel orientation. On color Doppler examinations, two lesions showed internal vascularity. Strain elastography was performed for four neuromas, resulting in scores of 1 (n=1, 4 (n=2, and 5 (n=1. The final assessment categories were BI-RADS 3 (n=2, 4A (n=2, and 4B (n=2. Conclusion On US, an oval shape, circumscribed margin, parallel orientation, and hypoechogenicity were the most frequent features of traumatic neuromas in breast cancer patients after mastectomy. Neuromas may show increased vascularity on color Doppler imaging and present as a hard mass on elastography.

Biliary stricture due to neuroma after an innocent blunt abdominal trauma.

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Katsinelos, P; Dimiropoulos, S; Galanis, I; Tsolkas, P; Paroutoglu, G; Arvaniti, M; Katsiba, D; Baltaglannis, S; Pilpilidis, I; Papagiannis, A; Vaslliadis, I

2002-10-01

A traumatic neuroma of the biliary tract is rarely associated with biliary obstruction. However, when it arises in the common bile duct (CBD) and is associated with obstructive jaundice, it is difficult to distinguish it from bile duct cancer. We describe a patient who developed obstructive jaundice and itching, due to CBD stricture, 8 years after innocent blunt abdominal trauma. The stricture was resected and hepatico-jejunal anastomosis was performed. Histological examination revealed a traumatic neuroma and a fibrous scar around the common bile duct. Symptoms disappeared following surgical removal of the lesion. Blunt abdominal injury may cause the late onset of a fibrous scar and traumatic neuroma in the common bile duct. To our knowledge, a traumatic neuroma of the biliary tract after blunt abdominal trauma has not been reported previously. We review the clinical picture of this relatively rare problem, along with its diagnosis, pathogenesis and treatment.

T1-nerve root neuroma presenting with apical mass and Horner's syndrome

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Podnar Simon

2007-03-01

Full Text Available Abstract Background The appearance of dumbbell neuroma of the first thoracic root is extremely rare. The extradural component of a T1-dumbbell neuroma may present as an apical mass. The diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and its intrathoracic extension demanded an extended posterior midline approach in the sitting position. Case presentation A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness in the affected forearm with some tingling in his fingers bilaterally. During the last two years the hand weakness was continuous and hypotrophy of the medial flexor and intrinsic hand muscles had become apparent. Electrophysiological studies revealed an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy in the upper extremity was negative. Repeated electrophysiological studies revealed fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed a large round apical mass on the affected side. A Horner's syndrome was noted at this point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural tumor with extension into the apex of the ipsilateral lung. The patient underwent surgery in sitting position using a left dorsal midline approach. Although the T1 root could not be preserved, the patient's neurological condition was unchanged after the surgery. Conclusion Extended posterior midline exposure described here using hemilaminectomy, unilateral facetectomy and costo-transversectomy is efficient and safe for one-stage removal of dumbbell tumors at the T1

Stereotactic radiosurgery for acoustic neuroma: a Canadian perspective

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Ross, I.B.; Tator, C.H.

1998-01-01

Stereotactically delivered radiation is now an accepted treatment for patients with acoustic neuroma. In some cases, patient preference may be the reason for its selection, while in others neurosurgeons may select it for patients who are elderly or have significant risk factors for conventional surgery. The majority of patients with acoustic neuroma treatment with stereotactic radiosurgery have been treated with the Gamma Knife, with follow ups of over 25 years in some instances. Other radiosurgical modalities utilizing the linear accelerator have been developed and appear promising, but there is no long-term: follow up. Canada does not possess a Gamma Knife facility, and its government-funded hospital and medical insurance agencies have made it difficult for patients to obtain reimbursement for Gamma Knife treatments in other countries. We review the literature to date on the various forms of radiation treatment for acoustic neuroma and discuss the current issues facing physicians and patients in Canada who wish to obtain their treatment of choice. (author)

Four cases of acoustic neuromas with normal hearing.

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Valente, M; Peterein, J; Goebel, J; Neely, J G

1995-05-01

In 95 percent of the cases, patients with acoustic neuromas will have some magnitude of hearing loss in the affected ear. This paper reports on four patients who had acoustic neuromas and normal hearing. Results from the case history, audiometric evaluation, auditory brainstem response (ABR), electroneurography (ENOG), and vestibular evaluation are reported for each patient. For all patients, the presence of unilateral tinnitus was the most common complaint. Audiologically, elevated or absent acoustic reflex thresholds and abnormal ABR findings were the most powerful diagnostic tools.

Summary and consensus in 7th International Conference on acoustic neuroma: An update for the management of sporadic acoustic neuromas

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Hao Wu

2016-12-01

Full Text Available Sporadic vestibular schwannoma (acoustic neuroma is a benign tumor arising from cochleovestibular nerve. Nowadays, various specialties and medical centers are treating this disease, and the multidisciplinary collaboration is the trend. In an effort to promote a uniform standard for reporting clinical results, even for treatment indications, the mainly controversies were posed and discussed during the 7th International Conference on acoustic neuroma, and the agreement was summarized by the Committee of this conference. The main symptoms grading and tumor stage should note its name of classification for making them comparable. The goal of the modern managements for vestibular schwannoma is to improve the quality of life with lower mortality, lower morbidity and better neurological function preservation. The experience of surgical team and their preference might be a major factor for the outcome. Because of lacking of long-term follow-up large data after radiotherapy, and with the development of microsurgery, radiotherapy is now less recommended except for recurrent cases or elderly patients. Keywords: Sporadic acoustic neuroma, Vestibular schwannoma, Management, Symptoms grading, Tumor stage, Microsurgery, Radiotherapy

''Dural tail'' adjacent to acoustic neuroma on MRI: a case report

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Lunardi, P.; Mastronardi, L.; Nardacci, B.; Acqui, M.; Fortuna, A.

1993-01-01

A 'dural tail' on Gd-DTPA-enhanced MRI has been often observed adjacent to meningiomas and considered to be useful in distinguishing meningioma of the cerebellopontine angle from acoustic neuroma. However, demonstration of a dural tail adjacent to an acoustic neuroma indicates that this sign is not specific. (orig.)

Hydroxyapatite cement cranioplasty in translabyrinthine acoustic neuroma surgery.

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Arriaga, Moisês A; Chen, Douglas A

2002-05-01

Hydroxyapatite cement cranioplasty (HAC) after translabyrinthine resection of acoustic neuroma is a promising new technique for wound reconstruction. This study reviews the efficacy of HAC for the prevention of cerebrospinal fluid (CSF) leakage and the long-term wound outcomes of HAC versus abdominal fat graft (AFG) reconstruction. This retrospective study of l08 consecutive acoustic neuromas operated on by Pittsburgh Ear Associates uses chart review, telephone interview, and mail questionnaire data. Fifty-four patients received AFG dural repair, and 54 patients received HAC. Seven AFG patients (12.5%) had CSF leaks versus 2 (3.7%) of the overall group of 54 HAC patients. However, none (0%) of the 47 HAC patients had CSF leakage with current HAC techniques. HAC also produced significantly less postauricular wound depression and superior cosmetic results in comparison with AFG. Although HAC patients experienced less postoperative discomfort, wound complications requiring medical or surgical intervention were extremely uncommon in both groups. HAC offers significant CSF leakage control and long-term cosmetic and comfort advantages over AFG alone. We recommend HAC as the standard closure technique for translabyrinthine acoustic neuroma surgery.

Traumatic facial nerve neuroma with facial palsy presenting in infancy.

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Clark, James H; Burger, Peter C; Boahene, Derek Kofi; Niparko, John K

2010-07-01

To describe the management of traumatic neuroma of the facial nerve in a child and literature review. Sixteen-month-old male subject. Radiological imaging and surgery. Facial nerve function. The patient presented at 16 months with a right facial palsy and was found to have a right facial nerve traumatic neuroma. A transmastoid, middle fossa resection of the right facial nerve lesion was undertaken with a successful facial nerve-to-hypoglossal nerve anastomosis. The facial palsy improved postoperatively. A traumatic neuroma should be considered in an infant who presents with facial palsy, even in the absence of an obvious history of trauma. The treatment of such lesion is complex in any age group but especially in young children. Symptoms, age, lesion size, growth rate, and facial nerve function determine the appropriate management.

Repeat Stereotactic Radiosurgery for Acoustic Neuromas

International Nuclear Information System (INIS)

Kano, Hideyuki; Kondziolka, Douglas; Niranjan, Ajay M.Ch.; Flannery, Thomas J.; Flickinger, John C.; Lunsford, L. Dade

2010-01-01

Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months). Results: At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS. Conclusions: With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.

Intratemporal facial nerve neuromas and their mimics: CT and MR findings

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Han, Moon Hee; Chang, Kee Hyun; Lee, Kyung Hwan; Cha, Sang Hoon; Kim, Chong Sun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Sang Joon [Chungang Gil General Hospital, Seoul (Korea, Republic of)

1992-05-15

CT and MR findings of nine cases with intra temporal facial nerve neuromas were described and compared with CT findings of 3 cases with facial nerve palsy and facial nerve canal erosion which may mimic facial nerve neuroma. The tympanic segment of the facial nerve was involved in 8 cases, mastoid segment in 7 cases and labyrinthine segment in 5 cases. The lesions were easily diagnosed with high resolution CT with bone algorithms by showing the expansion of bony structures along the course of the facial nerves. In 4 cases with large vertical segment tumors, extensive destruction of mastoid air cells and external auditory canals posed difficulty in making a diagnosis. Two out of 5 cases with labyrinthine segment involvement were presented as middle cranial fossa masses. MRI with enhancement was performed in 4 cases and was useful in characterizing the lesion as a tumor with its superior sensitivity to enhancement. Three cases of facial neuroma-mimicking lesion including post-inflammatory peri neural thickening, peri neural extension from parotid adenoid cystic carcinoma, and congenita; cholesteatoma showed irregular erosion or mild expansion of the facial nerve canal which may be helpful for differential diagnosis from neuromas.

Endobronchial neurogenic tumor: A combination of traumatic neuroma and neurofibroma

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Amit Tandon

2017-01-01

Full Text Available Traumatic neuromas are uncommon and benign lesions arising from a peripheral nerve injury during surgery. Here we describe a case with histopathologic features of both a traumatic neuroma and neurofibroma in a patient without integumentary physical exam findings nor prior surgical history. A 54 year old male was admitted for surgical debridement of a foot ulcer. During pre-operative evaluation and review of imaging multiple CT scans revealed a stable, 4 mm endobronchial lesion in the left lower lobe. Given history of nicotine abuse, bronchoscopy was performed. Bronchoscopy showed a pearly, polypoid lesion. Histopathological results showed strong positivity for S-100 protein and spindle cell proliferation. Repeat CT chest showed no new lesions in the bronchial tree. The rarity of this case is noted not only by the limited number of bronchial neurogenic tumors, but the combined features in this case of a traumatic neuroma and neurofibroma which has not been described.

Penile Traumatic Neuroma: A Late Complication of Penile Dorsal Neurotomy to Treat Premature Ejaculation

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Hyun Jun Park

2016-09-01

Conclusion: The main complications of SDN are recurrence of premature ejaculation, pain or paresthesia on the glans penis, and erectile dysfunction. However, no traumatic neuroma has been reported as a complication. We report that a traumatic neuroma can occur after SDN.

Resection planning for robotic acoustic neuroma surgery

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McBrayer, Kepra L.; Wanna, George B.; Dawant, Benoit M.; Balachandran, Ramya; Labadie, Robert F.; Noble, Jack H.

2016-03-01

Acoustic neuroma surgery is a procedure in which a benign mass is removed from the Internal Auditory Canal (IAC). Currently this surgical procedure requires manual drilling of the temporal bone followed by exposure and removal of the acoustic neuroma. This procedure is physically and mentally taxing to the surgeon. Our group is working to develop an Acoustic Neuroma Surgery Robot (ANSR) to perform the initial drilling procedure. Planning the ANSR's drilling region using pre-operative CT requires expertise and around 35 minutes' time. We propose an approach for automatically producing a resection plan for the ANSR that would avoid damage to sensitive ear structures and require minimal editing by the surgeon. We first compute an atlas-based segmentation of the mastoid section of the temporal bone, refine it based on the position of anatomical landmarks, and apply a safety margin to the result to produce the automatic resection plan. In experiments with CTs from 9 subjects, our automated process resulted in a resection plan that was verified to be safe in every case. Approximately 2 minutes were required in each case for the surgeon to verify and edit the plan to permit functional access to the IAC. We measured a mean Dice coefficient of 0.99 and surface error of 0.08 mm between the final and automatically proposed plans. These preliminary results indicate that our approach is a viable method for resection planning for the ANSR and drastically reduces the surgeon's planning effort.

Long-term mobile phone use and acoustic neuroma risk.

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Pettersson, David; Mathiesen, Tiit; Prochazka, Michaela; Bergenheim, Tommy; Florentzson, Rut; Harder, Henrik; Nyberg, Gunnar; Siesjö, Peter; Feychting, Maria

2014-03-01

There is concern about potential effects of radiofrequency fields generated by mobile phones on cancer risk. Most previous studies have found no association between mobile phone use and acoustic neuroma, although information about long-term use is limited. We conducted a population-based, nation-wide, case-control study of acoustic neuroma in Sweden. Eligible cases were persons aged 20 to 69 years, who were diagnosed between 2002 and 2007. Controls were randomly selected from the population registry, matched on age, sex, and residential area. Postal questionnaires were completed by 451 cases (83%) and 710 controls (65%). Ever having used mobile phones regularly (defined as weekly use for at least 6 months) was associated with an odds ratio (OR) of 1.18 (95% confidence interval = 0.88 to 1.59). The association was weaker for the longest induction time (≥10 years) (1.11 [0.76 to 1.61]) and for regular use on the tumor side (0.98 [0.68 to 1.43]). The OR for the highest quartile of cumulative calling time (≥680 hours) was 1.46 (0.98 to 2.17). Restricting analyses to histologically confirmed cases reduced all ORs; the OR for ≥680 hours was 1.14 (0.63 to 2.07). A similar pattern was seen for cordless land-line phones, although with slightly higher ORs. Analyses of the complete history of laterality of mobile phone revealed considerable bias in laterality analyses. The findings do not support the hypothesis that long-term mobile phone use increases the risk of acoustic neuroma. The study suggests that phone use might increase the likelihood that an acoustic neuroma case is detected and that there could be bias in the laterality analyses performed in previous studies.

Palisaded Encapsulated (Solitary Circumscribed) Neuroma of the Buccal Mucosa: a Rare Case.

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Atarbashi-Moghadam, Saede; Lotfi, Ali; Salehi Zalani, Saman; Mokhtari, Sepideh

2017-12-01

The rarity of oral soft tissue spindle cell tumors combined with overlapping microscopic patterns can make challenges in their diagnosis and treatment. Oral cavity palisaded encapsulated neuroma is an uncommon lesion which occurs often on the hard palate. It is essential for oral pathologists to be familiar with its histopathology of this lesion is essential since many lesions are probably diagnosed microscopically as neurofibroma or schwannoma. Here, we report a case of oral palisaded encapsulated (solitary circumscribed) neuroma in an unusual site.

Recurrent neuroma formation after lateral arm free flap coverage with neurorraphy to the posteroantebrachial nerve.

Science.gov (United States)

Peterson, Steven L; Gordon, Michael J

2004-09-01

We report a patient with previous wrist trauma and development of a symptomatic neuroma of the palmar cutaneous branch of the median nerve. The patient had previously been successfully treated with lateral arm free flap coverage with neurorrhaphy to a segment of the posteroantebrachial cutaneous nerve carried with the flap. Two years following this procedure the patient experienced re-onset of symptoms prompting surgical exploration of the area. At the time of operation a recurrent neuroma was found at the free distal terminus of the transferred posteroantebrachial cutaneous nerve. The neuroma was repositioned into the distal radius via a burr hole with relief of symptoms.

Novel experimental surgical strategy to prevent traumatic neuroma formation by combining a 3D-printed Y-tube with an autograft.

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Bolleboom, Anne; de Ruiter, Godard C W; Coert, J Henk; Tuk, Bastiaan; Holstege, Jan C; van Neck, Johan W

2018-02-09

OBJECTIVE Traumatic neuromas may develop after nerve injury at the proximal nerve stump, which can lead to neuropathic pain. These neuromas are often resistant to therapy, and excision of the neuroma frequently leads to recurrence. In this study, the authors present a novel surgical strategy to prevent neuroma formation based on the principle of centro-central anastomosis (CCA), but rather than directly connecting the nerve ends to an autograft, they created a loop using a 3D-printed polyethylene Y-shaped conduit with an autograft in the distal outlets. METHODS The 3D-printed Y-tube with autograft was investigated in a model of rat sciatic nerve transection in which the Y-tube was placed on the proximal sciatic nerve stump and a peroneal graft was placed between the distal outlets of the Y-tube to form a closed loop. This model was compared with a CCA model, in which a loop was created between the proximal tibial and peroneal nerves with a peroneal autograft. Additional control groups consisted of the closed Y-tube and the extended-arm Y-tube. Results were analyzed at 12 weeks of survival using nerve morphometry for the occurrence of neuroma formation and axonal regeneration in plastic semi-thin sections. RESULTS Among the different surgical groups, the Y-tube with interposed autograft was the only model that did not result in neuroma formation at 12 weeks of survival. In addition, a 13% reduction in the number of myelinated axons regenerating through the interposed autograft was observed in the Y-tube with autograft model. In the CCA model, the authors also observed a decrease of 17% in the number of myelinated axons, but neuroma formation was present in this model. The closed Y-tube resulted in minimal nerve regeneration inside the tube together with extensive neuroma formation before the entrance of the tube. The extended-arm Y-tube model clearly showed that the majority of the regenerating axons merged into the Y-tube arm, which was connected to the autograft

Novel model for end-neuroma formation in the amputated rabbit forelimb

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Kuiken Todd A

2010-03-01

Full Text Available Abstract Background The forelimb amputee poses many reconstructive challenges in the clinical setting, and there is a paucity of established surgical models for study. To further elucidate the pathogenic process in amputation neuroma formation, we created a reproducible, well-tolerated rabbit forelimb amputation model. Methods Upon approval from the Institutional Animal Care and Use Committee, 5 New Zealand White rabbits underwent left forelimb amputation. During this initial surgery, the median, radial and ulnar nerves were transected 1.6-2.5 (mean 2.0 cm distal to the brachial plexus, transposed onto the anterior chest wall and preserved at length. Six weeks subsequent to the amputation, the distal 5 mm of each neuroma was excised, and the remaining stump underwent histomorphometric analysis. Results The nerve cross sectional areas increased by factors of 1.99, 3.17, and 2.59 in the median (p = 0.077, radial (p Conclusion Given that the surgical model appears well-tolerated by the rabbits and that patterns of morphologic change are consistent and reproducible, we are encouraged to further investigate the utility of this model in the pathogenesis of neuroma formation.

Three Cycles of Radiofrequency Ablation Are More Efficacious Than Two in the Management of Morton's Neuroma.

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Brooks, David; Parr, Adam; Bryceson, William

2018-04-01

Morton's neuroma is a common cause of forefoot pain. Outcomes of conservative therapy are mixed and many patients undergo operative intervention. Radiofrequency ablation has recently gained favor as a treatment option, although the optimal regime is unknown. This study investigates the effectiveness of 2 versus 3 cycles of radiofrequency ablation for the treatment of Morton's neuroma. We surveyed a cohort of patients with Morton's neuroma who had progressed to radiofrequency ablation after failed conservative treatment. Patients received either 2 or 3 cycles of radiofrequency ablation by a single surgeon. We assessed patients based on their change in numerical pain rating scale, symptom improvement, complications, and progression to surgical excision through a series of telephone interviews. Outcomes between the 2 treatment arms were compared by parametric tests. Twenty-eight patients were included in the study. Eighteen patients with 21 neuromas received 2 cycles and 10 patients with 11 neuromas received 3 cycles. Mean time of follow-up was 12.9 months. Overall, 88% of patients were either very or moderately satisfied with their outcome. In patients who received 2 cycles mean numerical pain scores decreased from 7.9 ± 1.1 to 3.4 ± 2.4 postprocedure. Three patients progressed to operative excision. In patients who received 3 cycles, numerical pain scores decreased from 8.0 ± 1.0 to 1.5 ± 2.0 postprocedure. One patient progressed to operative excision. Patients who received 3 cycles had reduced medium-term pain postoperatively compared with 2 cycles (3.4 ± 2.4 vs 1.5 ± 2.0, P = .011). Radiofrequency ablation provides a high rate of patient satisfaction in the treatment of Morton's neuroma with few side effects. It appears that 3 cycles may be superior to 2 cycles but a randomized controlled trial will be required to confirm these results. Intervention, Level III: Comparative study without concurrent controls.

Impact of facial paralysis on patients with acoustic neuroma.

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Cross, T; Sheard, C E; Garrud, P; Nikolopoulos, T P; O'Donoghue, G M

2000-09-01

To assess the psychological distress, the ways of coping with that stress, and the self-esteem of patients with facial paralysis after acoustic neuroma surgery. Possible predictors and associations between these measures were also explored. Four validated questionnaires were completed by patients with facial paralysis after acoustic neuroma surgery: 1) the Derriford Appearance Scale (DAS) to measure psychological distress, 2) the COPE questionnaire to measure how patients cope with facial paralysis, 3) the Personal Report questionnaire to measure the self-esteem of patients, and 4) the Facial Paralysis Questionnaire (FPQ) to measure the severity of facial paralysis. One hundred three patients with facial paralysis after surgical removal of acoustic tumors. Distress spanned a wide range in these patients. There was no statistically significant association between the level of distress and the grade of facial paralysis or between time since operation and levels of distress. Women had higher levels of distress (P = .02) and a significant negative correlation was found between levels of distress and age (r = -0.28, P = .005). High levels of distress were associated with low levels of self-esteem, as shown by the significant negative correlation between level of distress and self-esteem (r = -0.59, P = .01). A significant correlation between distress and maladaptive coping (r = 0.31, P = .002) was also found. Stepwise multiple regression of the distress scores revealed that self-esteem was the most important contributing factor (standardized coefficient beta -0.60, P = .0001), followed by age (beta -0.24, P = .006) and sex (beta -0.21, P = .04). This model explained 44% of the distress variance. Clinicians must be aware of the distress felt by some patients experiencing facial palsy after acoustic neuroma surgery and that the level of distress may not be related to the clinical grade of the facial nerve paralysis. People with low self-esteem, young people, and women

Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

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Fuss, Martin; Debus, Juergen; Lohr, Frank; Huber, Peter; Rhein, Bernhard; Engenhart-Cabillic, Rita; Wannenmacher, Michael

2000-01-01

Purpose: Analysis of local tumor control and functional outcome following conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Patients and Methods: From 11/1989 to 9/1999 51 patients with acoustic neuromas have been treated by FSRT. Mean total dose was 57.6 ± 2.5 Gy. Forty-two patients have been followed for at least 12 months and were subject of an outcome analysis. Mean follow-up was 42 months. We analyzed local control, hearing preservation, and facial and trigeminal nerve functional preservation. We evaluated influences of tumor size, age, and association with neurofibromatosis Type 2 (NF2) on outcome and treatment related toxicity. Results: Actuarial 2- and 5-year tumor control rates were 100% and 97.7%, respectively. Actuarial useful hearing preservation rate was 85% at 2 and 5 years. New hearing loss was diagnosed in 4 NF2 patients. Pretreatment normal facial nerve function was preserved in all cases. Two cases of new or impaired trigeminal nerve dysesthesia required medication. No other cranial nerve deficit was observed. In Patients without NF2 tumor size or age had no influence on tumor control and cranial nerve toxicity. Diagnosis of NF2 was associated with higher risk of hearing impairment (p 0.0002), the hearing preservation rate in this subgroup was 60%. Conclusion: FSRT has been shown to be an effective means of local tumor control. Excellent hearing preservation rates and 5th and 7th nerve functional preservation rates were achieved. The results support the conclusion that FSRT can be recommended to patients with acoustic neuromas where special attention has to be taken to preserve useful hearing and normal cranial nerve function. For NF2 patients, FSRT may be the treatment of choice with superior functional outcome compared to treatment alternatives.

Traumatic neuroma after torticollis surgery: a rare occurrence

African Journals Online (AJOL)

2 Serrano Falcón C, Serrano Falcn MDM, Ruiz Villaverde R, Linares Solano J,. Serrano Ortega S. Amputation neuromas after neck surgery. Dermatol Online. J 2005; 11:2. 3 Lee IJ, Lim SY, Song HS, Park MC. Complete tight fibrous band release and resection in congenital muscular torticollis. J Plast Reconstr Aes Surg ...

Neuroma prevention by end-to-side neurorraphy: an experimental study in rats.

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Aszmann, Oskar C; Korak, Klaus J; Rab, Matthias; Grünbeck, Matthias; Lassmann, Hans; Frey, Manfred

2003-11-01

The successful treatment of painful neuromas remains a difficult goal to attain. In this report we explore the feasibility of neuroma prevention by insertion of the proximal end of a nerve through an end-to-side neurorraphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. Experiments were performed on a total of twenty 250-g Sprague-Dawley rats. Two groups of 10 animals were prepared. Group A served as an anatomic control. In group B the right saphenous nerve was transected and implanted end-to-side through an epineurial window into the tibial nerve distal to the trifurcation of the sciatic nerve. After 12 weeks the corresponding sensory neurons were identified by retrograde labeling techniques and histomorphometric analysis of the proximal and distal tibial nerve segments, and regular histology of the end-to-side site were performed. The results of the retrograde labeling of the corresponding sensory neuron pool of the saphenus nerve showed extensive labelling of the L1 to L3 spinal ganglions after intracutaneous tracer application of the planta pedis. The morphology of the end-to-side coaptation site and histomorphologic analysis prove that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwann cell tubes toward their targets. Axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or establish some type of end-organ contact so that a neuroma can be prevented. Whether these axons will lead to disturbing sensations such as paresthesia or dysesthesia in the newly found environment or remain silent codwellers, this experiment cannot answer. Long-term results of future clinical work will have to decide whether the prevention of the neuroma through end-to-side coaptation will be an appropriate therapy for this difficult problem.

Remission of severe restless legs syndrome and periodic limb movements in sleep after bilateral excision of multiple foot neuromas: a case report

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Lettau Ludwig A

2010-09-01

Full Text Available Abstract Introduction Restless legs syndrome is a sensorimotor neurological disorder characterized by an urge to move the legs in response to uncomfortable leg sensations. While asleep, 70 to 90 percent of patients with restless legs syndrome have periodic limb movements in sleep. Frequent periodic limb movements in sleep and related brain arousals as documented by polysomnography are associated with poorer quality of sleep and daytime fatigue. Restless legs syndrome in middle age is sometimes associated with neuropathic foot dysesthesias. The causes of restless legs syndrome and periodic limb movements in sleep are unknown, but the sensorimotor symptoms are hypothesized to originate in the central nervous system. We have previously determined that bilateral forefoot digital nerve impingement masses (neuromas may be a cause of both neuropathic foot dysesthesias and the leg restlessness of restless legs syndrome. To the best of our knowledge, this case is the first report of bilateral foot neuromas as a cause of periodic limb movements in sleep. Case presentation A 42-year-old Caucasian woman with severe restless legs syndrome and periodic limb movements in sleep and bilateral neuropathic foot dysesthesias was diagnosed as having neuromas in the second, third, and fourth metatarsal head interspaces of both feet. The third interspace neuromas represented regrowth (or 'stump' neuromas that had developed since bilateral third interspace neuroma excision five years earlier. Because intensive conservative treatments including repeated neuroma injections and various restless legs syndrome medications had failed, radical surgery was recommended. All six neuromas were excised. Leg restlessness, foot dysesthesias and subjective sleep quality improved immediately. Assessment after 18 days showed an 84 to 100 percent reduction of visual analog scale scores for specific dysesthesias and marked reductions of pre-operative scores of the Pittsburgh sleep

The accuracy of ultrasonography and magnetic resonance imaging for the diagnosis of Morton's neuroma: a systematic review

International Nuclear Information System (INIS)

Xu, Z.; Duan, X.; Yu, X.; Wang, H.; Dong, X.; Xiang, Z.

2015-01-01

Aim: To determine the accuracy of MRI versus ultrasound for Morton's neuroma. Materials and methods: A search was undertaken for clinical studies published in any language in PubMed up to the date of December 2013. Studies assessing the accuracy of the ultrasound or MRI for the diagnosis of Morton's neuroma were included. Data were pooled for meta-analysis. Study selection, data collection, and extraction were performed independently by two authors. Meta-disc 1.4 and Revman 5.2 software were applied for statistical analysis. Results: The study included 12 studies; 217 patients underwent MRI and 241 underwent ultrasound examinations. There appeared greater diagnostic accuracy for ultrasound than MRI for the diagnosis of Morton's neuroma (ultrasound sensitivity 90%, specificity 88%, positive likelihood ratio 2.77, negative likelihood ratio 0.16 versus MRI sensitivity 93%, specificity 68%, positive likelihood ratio 1.89, negative likelihood ratio 0.19). Conclusions: The available evidence suggests that ultrasound can provide better accuracy for the diagnosis of Morton's neuroma than MRI

The treatment for acoustic neuromas. Indication and results of gamma knife radiosurgery and surgery

International Nuclear Information System (INIS)

Iwai, Yoshiyasu; Yamanaka, Kazuhiro; Uyama, Taichi; Morikawa, Toshie; Honda, Yuji; Matsusaka, Yasuhiro; Komiyama, Masaki; Yasui, Toshihiro

2004-01-01

We evaluated the treatment results of acoustic neuromas in the era of radiosurgery. We treated acoustic neuromas using the following strategy. Small to medium size tumors (below 3 cm) were treated by gamma knife radiosurgery and large tumors (above 3 cm) were treated using a combination of surgery and radiosurgery. Using gamma knife radiosurgery we were able to achieve 96.4% of clinical tumor growth control with 0.7% incidence of trigeminal neuropathy (without new facial neuropathy). We used low dose radiosurgery (average tumor marginal dose 11.8 Gy) with a follow-up of an average of 54 months. For the 17 patients with large tumors treated by the combination of surgery and radiosurgery who could be followed up for over 24 months after radiosurgery, we were able to preserve normal facial function (House-Brackmann grade I-II) in 70.6% of the patients after subtotal removal. High clinical tumor growth control for residual tumor was achieved in 94.1% of subjects with an average of 40 months follow-up. By using this strategy, the treatment outcome for acoustic neuroma is improved from the standpoint of functional outcome and maintaining the patient's quality of life. (author)

Calculating the tumor volume of acoustic neuromas: comparison of ABC/2 formula with planimetry method.

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Yu, Yi-Lin; Lee, Meei-Shyuan; Juan, Chun-Jung; Hueng, Dueng-Yuan

2013-08-01

The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (6 ml). The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R2=0.985). Pearson correlation coefficient (r=0.993, pABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. Copyright © 2013 Elsevier B.V. All rights reserved.

CT and MRI of haemorrhage into intracranial neuromas

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Asari, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Katayama, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Itoh, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Tsuchida, S. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan)); Ohmoto, T. (Dept. of Neurological Surgery, Okayama Univ. Medical School, Okayama City (Japan))

1993-04-01

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spin-echo pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effectie than CT in detecting haemorrhage into the tumours and in staging it. (orig.)

Traumatic Neuroma in a Breast Cancer Patient After Modified Radical Mastectomy: A Case Report

International Nuclear Information System (INIS)

Kim, Eun Young; Kang, Doo Kyoung; Kim, Tae Hee; Kim, Ku Sang; Yim, Hyunee

2011-01-01

Traumatic neuromas are rare benign lesions that develop from non-neoplastic proliferation of axons, schwann cells, and fibroblasts at the proximal end of transected or injured nerves as a result of trauma or surgery. We present the case of a traumatic neuroma in a 47-year-old female who was treated with a right modified radical mastectomy for breast cancer 14 years ago. Ultrasound examination revealed an oval-shaped hypoechoic nodule at the 9-O'clock position in the right chest wall. Color Doppler imaging showed no increased blood flow and a positron emission tomography-computed tomography examination revealed no fluorodeoxyglucose uptake in this nodule. The typical histologic findings were present.

MR of acoustic neuromas

International Nuclear Information System (INIS)

Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide

1989-01-01

In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T 1 -weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author)

Vestibular Schwannoma or acoustic neuroma

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Hekmatara M

1997-04-01

Full Text Available Vestibular schwannoma is the most common tumor of the posterior fossa of the skull. Patients referred with the primary otologic symptoms such as hearing loss, tinnitus, vertigo, imbalance, and the cranial nerve palsy. Thirty-three patients were operated and treated by a team of otolaryngologist and neurosurgeon, anudiometrist, and internist. Patients'chiefcomplaint was due to 94% hearing loss and 27% tinnitus. They scarcely complain of vertigo. If a patient refers with the palsy or paralysis of facial nerve preoperation, we must think of the facial nerve schwannoma or hemangioma or congential cholestoma or malignant metastases rather than acoustic neuroma. The best way for preoperative diagnosis is audiometry, ABR (Auditory Brain Response, and SDS (speech discrimination score with 90% success, but computer Tomography (CT scan and MRI (Magnetic Resonance Image are the valuable anatomic diagnostic radiographic devices. The best method of operation is translabirynthine approach (TLA, since it has the advantages such as an easy access to nerve paths and being the nearest path to CPA (Cerebellopontine Angle. Physicians ought to talk to patients about the importance of the microscopic surgery, surgical methods, and their probable diverse effects such as hearing loss, facial nerve palsy, and intracranial problems.

Stereotactic radiosurgery using the gamma knife for acoustic neuromas

International Nuclear Information System (INIS)

Foote, Robert L.; Coffey, Robert J.; Swanson, Jerry W.; Harner, Stephen G.; Beatty, Charles W.; Kline, Robert W.; Stevens, Lorna N.; Hu, Theresa C.

1995-01-01

Purpose: To assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Methods and Materials: Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompassed within the prescribed isodose line varied from 266 to 8,667 mm 3 (median: 3,135 mm 3 ). Tumors ≤ 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. The median number of isocenters per tumor was 5 (range: 1-12). Results: At a median follow-up of 16 months (range: 2.5-36 months), all patients were alive. Thirty-five patients had follow-up imaging studies. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% ± 17.3, respectively. Conclusion: Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients

Ultrasound versus magnetic resonance imaging for Morton neuroma: systematic review and meta-analysis

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Bignotti, Bianca; Martinoli, Carlo [University of Genoa, Radiology Department, Genoa, Genova (Italy); Signori, Alessio; Sormani, Maria Pia [University of Genoa, Institute of Statistics, Department of Health Sciences, Genoa (Italy); Molfetta, Luigi [University of Genoa, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics (DINOGMI), Genoa (Italy); Tagliafico, Alberto [University of Genoa, Institute of Anatomy, Department of Experimental Medicine, Genoa (Italy)

2015-08-15

To compare ultrasound (US) and magnetic resonance imaging (MRI) in the diagnosis of Morton's neuroma. Studies that assessed the diagnostic accuracy of US and MRI for Morton's neuroma were retrieved from major medical libraries independently by two reviewers up to 1 April 2014. Predefined inclusion and exclusion criteria were adopted. 277 studies were initially found, and the meta-analysis was conducted on 14 studies. US sensitivity was studied in five studies, MRI sensitivity in three studies, and both in six studies. All studies used surgery as the reference standard. A high sensitivity (SE) of diagnostic testing was observed for both US (SE (95 % CI) = 0.91 (0.83-0.96)) and MRI (SE (95 % CI) = 0.90 (0.82-0.96)) with no significant differences between the two modalities in diagnosis (Q test p = 0.88). For MRI, specificity of test was 1.00 with a pooled estimation of 1.00 (0.73-1.00), while the pooled specificity was 0.854 (95 % CI: 0.41-1.00) for US. No differences were observed between US and MRI in study design (p = 0.76). This meta-analysis shows that the SE of US (0.91) is equal to (p = 0.88) that of MRI (0.90) for identification of Morton's neuroma. (orig.)

Traumatic Neuroma in a Breast Cancer Patient After Modified Radical Mastectomy: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Young; Kang, Doo Kyoung; Kim, Tae Hee [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of); Kim, Ku Sang [Dept. of Surgery, Ajou University School of Medicine, Suwon (Korea, Republic of); Yim, Hyunee [Dept. of Pathology, Ajou University School of Medicine, Suwon (Korea, Republic of)

2011-05-15

Traumatic neuromas are rare benign lesions that develop from non-neoplastic proliferation of axons, schwann cells, and fibroblasts at the proximal end of transected or injured nerves as a result of trauma or surgery. We present the case of a traumatic neuroma in a 47-year-old female who was treated with a right modified radical mastectomy for breast cancer 14 years ago. Ultrasound examination revealed an oval-shaped hypoechoic nodule at the 9-O'clock position in the right chest wall. Color Doppler imaging showed no increased blood flow and a positron emission tomography-computed tomography examination revealed no fluorodeoxyglucose uptake in this nodule. The typical histologic findings were present.

Dose and diameter relationships for facial, trigeminal, and acoustic neuropathies following acoustic neuroma radiosurgery

International Nuclear Information System (INIS)

Flickinger, John C.; Kondziolka, Douglas; Lunsford, L. Dade

1996-01-01

Purpose and objective: To define the relationships between dose and tumor diameter for the risks of developing trigeminal, facial, and acoustic neuropathies after acoustic neuroma radiosurgery, a large single-institution experience was analyzed. Materials and methods: Two hundred and thirty-eight patients with unilateral acoustic neuromas who underwent Gamma knife radiosurgery between 1987-1994 with 6-91 months of follow-up (median 30 months) were studied. Minimum tumor doses were 12-20 Gy (median 15 Gy). Transverse tumor diameter varied from 0.3-5.5 cm (median 2.1 cm). The relationships of dose and diameter to the development of cranial neuropathies were delineated by multivariate logistic regression. Results: The development of post-radiosurgery neuropathies affecting cranial nerves V, VII, and VIII were correlated with minimum tumor dose and transverse tumor diameter (P min for VIII where P=0.10). A comparison of the dose-diameter response curves showed the acoustic nerve to be the most sensitive to doses of 12-16 Gy and the facial nerve to be the least sensitive. Conclusion: The risks of developing trigeminal, facial, and acoustic neuropathies following acoustic neuroma radiosurgery can be predicted from the transverse tumor diameter and the minimum tumor dose using models constructed from data presently available

VESTIBULAR SCHWANNOMA (ACOUSTIC NEUROMA) MIMICKING TEMPOROMANDIBULAR DISORDERS: A CASE REPORT

Science.gov (United States)

Bisi, Maurício A.; Selaimen, Caio M. P.; Chaves, Karen D.; Bisi, Melissa C.; Grossi, Márcio L.

2006-01-01

Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma). Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI) has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case. PMID:19089251

Reexcision Perineural Invasion and Epithelial Sheath Neuroma Possibly on a Spectrum of Postinjury Reactive Hyperplasia Mediated by IL-6.

Science.gov (United States)

Wang, James Y; Nuovo, Gerard; Kline, Mitchell; Magro, Cynthia M

2017-01-01

Epithelial sheath neuroma is a rarely recognized but established entity in the medical literature. First described in 2000 by Requena et al, there have only been 7 published cases to date, mostly in female patients and presenting as symptomatic solitary lesions on the back without a known history of trauma. In 2006, Beer et al described and reviewed a dozen cases in which epithelial sheath neuroma-like features were seen in the advent of a surgical procedure, which was termed "re-excision perineural invasion" and attributed to possible eccrine duct implantation during surgery. Our case is a 66-year-old male patient who underwent an excision of a melanocytic neoplasm in which a reactive epithelial sheath neuroma was incidentally discovered in the excision specimen, adjacent to the biopsy site cicatrix. Histologically, there was benign cutaneous nerve hyperplasia with a proliferation of squamous epithelium in intimate apposition to the nerve bundles in the superficial dermis. We postulate that the process active in the formation of re-excision perineural invasion is the same as in epithelial sheath neuroma and that minor trauma not appreciable on histologic examination is responsible in the latter entity. We performed IL-6 staining and documented that IL-6 was upregulated at the interface of the nerve and reactive epithelium, but was absent in nerves distant from the site of surgery, suggesting that IL-6 may be essential to the lesion's development. The recognition of reactive epithelial sheath neuroma including the subcategory of re-excision perineural invasion is crucial for the dermatopathologist to prevent mislabeling this reactive entity as a perineural squamous cell carcinoma, which has clinical consequences for the patient such as wider re-excision and radiation treatment. Additionally, we have identified a potential pathophysiologic basis for this lesion.

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

International Nuclear Information System (INIS)

Litre, Fabien; Rousseaux, Pascal; Jovenin, Nicolas; Bazin, Arnaud; Peruzzi, Philippe; Wdowczyk, Didier; Colin, Philippe

2013-01-01

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss

Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

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Litre, Fabien [Hôpital Maison Blanche, Reims Cedex (France); Rousseaux, Pascal [Hôpital Maison Blanche, Reims Cedex (France); Jovenin, Nicolas [Institut Jean Godinot, Reims Cedex (France); Bazin, Arnaud; Peruzzi, Philippe [Hôpital Maison Blanche, Reims Cedex (France); Wdowczyk, Didier; Colin, Philippe [Institut du Cancer Reims Courlancy, Reims (France)

2013-02-15

Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss.

Clinical predictors of facial nerve outcome after translabyrinthine resection of acoustic neuromas.

Science.gov (United States)

Shamji, Mohammed F; Schramm, David R; Benoit, Brien G

2007-01-01

The translabyrinthine approach to acoustic neuroma resection offers excellent exposure for facial nerve dissection with 95% preservation of anatomic continuity. Acceptable outcome in facial asymptomatic patients is reported at 64-90%, but transient postoperative deterioration often occurs. The objective of this study was to identify preoperative clinical presentation and intraoperative surgical findings that predispose patients to facial nerve dysfunction after acoustic neuroma surgery. The charts of 128 consecutive translabyrinthine patients were examined retrospectively to identify new clinical and intraoperative predictors of facial nerve outcome. Postoperative evaluation of patients to normal function or mild asymmetry upon close inspection (House-Brackmann grades of I or II) was defined as an acceptable outcome, with obvious asymmetry to no movement (grades III to VI) defined as unacceptable. Intraoperative nerve stimulation was performed in all cases, and clinical grading was performed by a single neurosurgeon in all cases. Among patients with no preoperative facial nerve deficit, 87% had an acceptable result. Small size (P mA (P< 0.01) were reaffirmed as predictive of functional nerve preservation. Additionally, preoperative tinnitus (P = 0.03), short duration of hearing loss (P< 0. 01), and lack of subjective tumour adherence to the facial nerve (P = 0.02) were independently correlated with positive outcome. Our experience with the translabyrinthine approach reveals the previously unestablished associations of facial nerve outcome to include presence of tinnitus and duration of hypoacusis. Independent predictors of tumour size and nerve stimulation thresholds were reaffirmed, and the subjective description of tumour adherence to the facial nerve making dissection more difficult appears to be important.

Enhanced intrinsic radiosensitivity after treatment with stereotactic radiosurgery for an acoustic neuroma

International Nuclear Information System (INIS)

Adams, Gerard; Martin, Olga A.; Roos, Daniel E.; Lobachevsky, Pavel N.; Potter, Andrew E.; Zacest, Andrew C.; Bezak, Eva; Bonner, William M.; Martin, Roger F.; Leong, Trevor

2012-01-01

Enhanced radiosensitivity is an uncommon phenomenon attributable to deficient DNA repair after radiotherapy which can be assessed with the γ-H2AX assay. Reports of radiosensitivity after stereotactic radiosurgery (SRS) are uncommon. We describe a case where the clinical, radiological and laboratory findings suggest enhanced radiosensitivity after SRS for an acoustic neuroma.

Haemorrhagic acoustic neuroma with features of a vascular malformation. A case report

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Benhaiem-Sigaux, N. [Dept. of Pathology, Hopital Henri Mondor, Creteil (France); Ricolfi, F. [Dept. of Neuroradiology, Henri Mondor Hospital, Creteil (France); Torres-Diaz, A.; Keravel, Y. [Dept. of Neurosurgery, Henri Mondo Hospital, Creteil (France); Poirier, J. [Dept. of Histology, Pitie-Salpetriere Hospital, Paris (France)

1999-10-01

A 55-year-old man with hearing loss presented with vertigo and vomiting. CT tomography and MRI demonstrated a cerebellopontine angle mass with foci of haemorrhage. An angiomatous tumour, with large abnormal veins adhering to the capsule, was completely removed. Histologically, the tumour was an acoustic neuroma with abnormal vascularisation and limited intratumoral haemorrhage. (orig.)

Haemorrhagic acoustic neuroma with features of a vascular malformation. A case report

International Nuclear Information System (INIS)

Benhaiem-Sigaux, N.; Ricolfi, F.; Torres-Diaz, A.; Keravel, Y.; Poirier, J.

1999-01-01

A 55-year-old man with hearing loss presented with vertigo and vomiting. CT tomography and MRI demonstrated a cerebellopontine angle mass with foci of haemorrhage. An angiomatous tumour, with large abnormal veins adhering to the capsule, was completely removed. Histologically, the tumour was an acoustic neuroma with abnormal vascularisation and limited intratumoral haemorrhage. (orig.)

The use of multimedia as an adjunct to the informed consent process for Morton's neuroma resection surgery.

Science.gov (United States)

Wang, Calvin; Ammon, Peter; Beischer, Andrew D

2014-10-01

The purpose of this study was to assess if a computer-based multimedia education module (MEM) improved patients' comprehension when used as an adjunct to the standard verbal consent process for Morton's neuroma resection surgery. Nineteen patients (15 females and 4 males) considered candidates for Morton's neuroma resection surgery were prospectively recruited. A standardized verbal discussion was had with each patient regarding risks and benefits of surgery, alternative treatments, and the usual postoperative course. Patient understanding was then assessed with a questionnaire. Each patient subsequently viewed the MEM and the questionnaire was repeated. Patients also rated ease of understanding and satisfaction with both methods of patient education. Patients answered a significantly greater proportion of correct answers after viewing the MEM module (85%), compared to verbal discussion alone (61%) (P = .002). Patients rated both the ease of understanding of the module and amount of information provided by the module as a mean of 9.3 cm on a 10 cm Visual Analog Scale (VAS). The majority of patients (76%) rated the multimedia tool as having answered their questions about surgery as well or better than the treating surgeon. An interactive multimedia educational tool was a useful adjunct to the informed consent process for patients considering Morton's neuroma resection surgery. Level II, prospective cohort study. © The Author(s) 2014.

Acoustic neuroma: predominance of Antoni type B cells in tumors of patients with vestibular paresis.

NARCIS (Netherlands)

Stipkovits, E.M.; Graamans, K.; Jansen, G.H.; Velthof, M.A.

2001-01-01

OBJECTIVE: This study aimed to investigate whether in patients with acoustic neuroma (AN), the presence or absence of vestibular symptoms is related to the histologic characteristics of the tumor. STUDY DESIGN: The study design was a retrospective clinical study. SETTING: The study was conducted at

Calculation of cranial nerve complication probability for acoustic neuroma radiosurgery

International Nuclear Information System (INIS)

Meeks, Sanford L.; Buatti, John M.; Foote, Kelly D.; Friedman, William A.; Bova, Francis J.

2000-01-01

Purpose: Estimations of complications from stereotactic radiosurgery usually rely simply on dose-volume or dose-diameter isoeffect curves. Due to the sparse clinical data available, these curves have typically not considered the target location in the brain, target histology, or treatment plan conformality as parameters in the calculation. In this study, a predictive model was generated to estimate the probability of cranial neuropathies as a result of acoustic schwannoma radiosurgery. Methods and Materials: The dose-volume histogram reduction scheme was used to calculate the normal tissue complication probability (NTCP) from brainstem dose-volume histograms. The model's fitting parameters were optimized to provide the best fit to the observed complication data for acoustic neuroma patients treated with stereotactic radiosurgery at the University of Florida. The calculation was then applied to the remainder of the patients in the database. Results: The best fit to our clinical data was obtained using n = 0.04, m = 0.15, and no. alphano. /no. betano. = 2.1 Gy -1 . Although the fitting parameter m is relatively consistent with ranges found in the literature, both the volume parameter, n, and no. alphano. /no. betano. are much smaller than the values quoted in the literature. The fit to our clinical data indicates that brainstem, or possibly a specific portion of the brainstem, is more radiosensitive than the parameters in the literature indicate, and that there is very little volume effect; in other words, irradiation of a small fraction of the brainstem yields NTCPs that are nearly as high as those calculated for entire volume irradiation. These new fitting parameters are specific to acoustic neuroma radiosurgery, and the small volume effect that we observe may be an artifact of the fixed relationship of acoustic tumors to specific regions of the brainstem. Applying the model to our patient database, we calculate an average NTCP of 7.2% for patients who had no

A case-case study of mobile phone use and acoustic neuroma risk in Japan.

Science.gov (United States)

Sato, Yasuto; Akiba, Suminori; Kubo, Osami; Yamaguchi, Naohito

2011-02-01

Results of case-control studies of mobile phone use and acoustic neuroma have been inconsistent. We conducted a case-case study of mobile phone use and acoustic neuroma using a self-administered postal questionnaire. A total of 1589 cases identified in 22 hospitals throughout Japan were invited to participate, and 787 cases (51%) actually participated. Associations between laterality of mobile phone use prior to the reference dates (1 and 5 years before diagnosis) and tumor location were analyzed. The overall risk ratio was 1.08 (95% confidence interval (CI), 0.93-1.28) for regular mobile phone use until 1 year before diagnosis and 1.14 (95% CI, 0.96-1.40) for regular mobile phone use until 5 years before diagnosis. A significantly increased risk was identified for mobile phone use for >20 min/day on average, with risk ratios of 2.74 at 1 year before diagnosis, and 3.08 at 5 years before diagnosis. Cases with ipsilateral combination of tumor location and more frequently used ear were found to have tumors with smaller diameters, suggesting an effect of detection bias. Furthermore, analysis of the distribution of left and right tumors suggested an effect of tumor-side-related recall bias for recall of mobile phone use at 5 years before diagnosis. The increased risk identified for mobile phone users with average call duration >20 min/day should be interpreted with caution, taking into account the possibilities of detection and recall biases. However, we could not conclude that the increased risk was entirely explicable by these biases, leaving open the possibility that mobile phone use increased the risk of acoustic neuroma. Copyright © 2010 Wiley-Liss, Inc.

Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery

International Nuclear Information System (INIS)

Karpinos, Marianna; Teh, Bin S.; Zeck, Otto; Carpenter, L. Steven; Phan, Chris; Mai, W.-Y.; Lu, Hsin H.; Chiu, J. Kam; Butler, E. Brian; Gormley, William B.; Woo, Shiao Y.

2002-01-01

Purpose: Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery. Our objective was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome, and patient satisfaction. Methods and Materials: To compare radiosurgery with microsurgery, we analyzed 96 patients with unilateral acoustic neuromas treated with Leksell Gamma Knife or microsurgery at Memorial Hermann Hospital, Houston, Texas, between 1993 and 2000. Radiosurgery technique involved multiple isocenter (1-30 single fraction fixed-frame magnetic resonance imaging) image-based treatment with a mean dose prescription of 14.5 Gy. Microsurgery included translabyrinthine, suboccipital, and middle fossa approaches with intraoperative neurophysiologic monitoring. Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group. The tumors were divided into small 4.0 cm. Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months (3-84 months) vs. 24 months (3-72 months). Results: There was no statistical significance in tumor growth control between the two groups, 100% in the microsurgery group vs. 91% in the radiosurgery group (p>0.05). Radiosurgery was more effective than microsurgery in measurable hearing preservation, 57.5% vs. 14.4% (p=0.01). There was no difference in serviceable hearing preservation between the two groups. Microsurgery was associated with a greater rate of facial and trigeminal neuropathy in the immediate postoperative period and at long-term follow-up. The rate of development of facial neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (35% vs. 0%, p<0.01 in the immediate postsurgical period and 35.3% vs. 6.1%, p=0.008, at long

Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery

Energy Technology Data Exchange (ETDEWEB)

Karpinos, Marianna; Teh, Bin S; Zeck, Otto; Carpenter, L Steven; Phan, Chris; Mai, W -Y; Lu, Hsin H; Chiu, J Kam; Butler, E Brian; Gormley, William B; Woo, Shiao Y

2002-12-01

Purpose: Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery. Our objective was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome, and patient satisfaction. Methods and Materials: To compare radiosurgery with microsurgery, we analyzed 96 patients with unilateral acoustic neuromas treated with Leksell Gamma Knife or microsurgery at Memorial Hermann Hospital, Houston, Texas, between 1993 and 2000. Radiosurgery technique involved multiple isocenter (1-30 single fraction fixed-frame magnetic resonance imaging) image-based treatment with a mean dose prescription of 14.5 Gy. Microsurgery included translabyrinthine, suboccipital, and middle fossa approaches with intraoperative neurophysiologic monitoring. Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group. The tumors were divided into small <2.0 cm, medium 2.0-3.9 cm, or large >4.0 cm. Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months (3-84 months) vs. 24 months (3-72 months). Results: There was no statistical significance in tumor growth control between the two groups, 100% in the microsurgery group vs. 91% in the radiosurgery group (p>0.05). Radiosurgery was more effective than microsurgery in measurable hearing preservation, 57.5% vs. 14.4% (p=0.01). There was no difference in serviceable hearing preservation between the two groups. Microsurgery was associated with a greater rate of facial and trigeminal neuropathy in the immediate postoperative period and at long-term follow-up. The rate of development of facial neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (35% vs. 0%, p<0.01 in the immediate postsurgical period and 35

SU-E-T-14: A Comparative Study Between Forward and Inverse Planning in Gamma Knife Radiosurgery for Acoustic Neuroma Tumours

Energy Technology Data Exchange (ETDEWEB)

Gopishankar, N; Agarwal, Priyanka; Bisht, Raj Kishor; Kale, S S; Rath, G K; Chander, S; Sharma, B S [All India Institute of Medical Sciences, New Delhi (India)

2015-06-15

Purpose: To evaluate forward and inverse planning methods for acoustic neuroma cases treated in Gamma Knife Perfexion. Methods: Five patients with acoustic neuroma tumour abutting brainstem were planned twice in LGP TPS (Version 10.1) using TMR10 algorithm. First plan was entirely based on forward planning (FP) in which each shot was chosen manually. Second plan was generated using inverse planning (IP) for which planning parameters like coverage, selectivity, gradient index (GI) and beam-on time threshold were set. Number of shots in IP was automatically selected by objective function using iterative process. In both planning methods MRI MPRAGE sequence images were used for tumour localization and planning. A planning dose of 12Gy at 50% isodose level was chosen. Results and Discussion: Number of shots used in FP was greater than IP and beam-on time in FP was in average 1.4 times more than IP. One advantage of FP was that the brainstem volume subjected to 6Gy dose (25% isodose) was less in FP than IP. Our results showed use of more number of shots as in FP results in GI less than or equal to 2.55 which is close to its lower limit. Dose homogeneity index (DHI) analysis of FP and IP showed average values of 0.59 and 0.67 respectively. General trend in GK for planning in acoustic neuroma cases is to use small collimator shots to avoid dose to adjacent critical structures. More number of shots and prolonged treatment time causes inconvenience to the patients. Similarly overuse of automatic shot shaping as in IP results in increased scatter dose. A compromise is required in shot selection for these cases. Conclusion: IP method could be used in acoustic neuroma cases to decrease treatment time provided the source sector openings near brainstem are shielded or adjusted appropriately to reduce brainstem dose.

Acoustic neuromas: single dose vs fractionated therapy

Energy Technology Data Exchange (ETDEWEB)

Fuss, M; Debus, J; Lohr, F; Engenhart-Cabillic, R; Wannenmacher, M

1997-07-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Radiosurgery supported in the lineal accelerator for the acoustic neuroma treatment

International Nuclear Information System (INIS)

Santos Ortega, M.; Gutierrez Diaz, J.; Rodriguez Villaba, S.; Garcia Berrocal, I.; Samblas Garcia, J.; Bustos Perez de Salcedo, J.C.; Ortiz de Urbina, D.; Donckaster Clavero, G.; Delgado Rodriguez, J.M.; Sansivirini Valle, F.

1996-01-01

Radiosurgery becomes in a great interest technique in acoustic neuroma treatments. We present preliminary results over 74 neurinomas patients in our Unit. From August 1991 to August 1994, 74 consecutive patients with acoustic neuromas, median age 50 yrs. has been treated in our Unit. A SRS 200 radiosurgery system was employed using a 6 MV photon beam Linear Accelerator as radiation source. In every case treatment dose was lesser than 18 gy (14-16 Gy). Before treatment all patients were evaluated with MRI and neurological examination, acoustic test included. This screening was repeated each six months during the follow up. Tumoral control was defined both, as no changes or diminishing in tumoral size, observed in sequential MRI studies with gadolinium and comparable techniques. The median fallow up is 18 months. Tumor control is 88,5%. In 30 patients control means dismissing in tumoral size. In 10 patients tumoral progression was evident, in a half of their a neurofibromatosis type II was previously diagnosed. The neurological function during the follow up shown improve or estabilitation in symptoms, for 85% VII pair patients, 83% in VII pair patients, 86% in V pair patients and 83% in cerebellar disfunction patients. Although preliminaries, this dates showing the efficacy of radiosurgery in tumoral control of patients with neurinomas with doses laser than 18 Gy. This dose are safe with toxicities around 15%, mainly in transitory presentations. (Auhtor) 67 refs

[Descending hypoglossal branch-facial nerve anastomosis in treating unilateral facial palsy after acoustic neuroma resection].

Science.gov (United States)

Liang, Jiantao; Li, Mingchu; Chen, Ge; Guo, Hongchuan; Zhang, Qiuhang; Bao, Yuhai

2015-12-15

To evaluate the efficiency of the descending hypoglossal branch-facial nerve anastomosis for the severe facial palsy after acoustic neuroma resection. The clinical data of 14 patients (6 males, 8 females, average age 45. 6 years old) underwent descending hypoglossal branch-facial nerve anastomosis for treatment of unilateral facial palsy was analyzed retrospectively. All patients previously had undergone resection of a large acoustic neuroma. House-Brackmann (H-B) grading system was used to evaluate the pre-, post-operative and follow up facial nerve function status. 12 cases (85.7%) had long follow up, with an average follow-up period of 24. 6 months. 6 patients had good outcome (H-B 2 - 3 grade); 5 patients had fair outcome (H-B 3 - 4 grade) and 1 patient had poor outcome (H-B 5 grade) Only 1 patient suffered hemitongue myoparalysis owing to the operation. Descending hypoglossal branch-facial nerve anastomosis is effective for facial reanimation, and it has little impact on the function of chewing, swallowing and pronunciation of the patients compared with the traditional hypoglossal-facial nerve anastomosis.

Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: early results of a prospective clinical study

International Nuclear Information System (INIS)

Meijer, O.W.M.; Wolbers, J.G.; Baayen, J.C.; Slotman, B.J.

2000-01-01

Purpose: To prospectively assess the local control and toxicity rate in acoustic neuroma patients treated with linear accelerator-based radiosurgery and fractionated stereotactic radiation therapy. Methods and Materials: We evaluated 37 consecutive patients treated with stereotactic radiation therapy for acoustic neuroma. All patients had progressive tumors, progressive symptoms, or both. Mean tumor diameter was 2.3 cm (range 0.8-3.3) on magnetic resonance (MR) scan. Dentate patients were given a dose of 5 x 4 Gy or 5 x 5 Gy and edentate patients were given a dose of 1 x 10 Gy or 1 x 12.50 Gy prescribed to the 80% isodose. All patients were treated with a single isocenter. Results: With a mean follow-up period of 25 months (range 12-61), the actuarial local control rate at 5 years was 91% (only 1 patient failed). The actuarial rate of hearing preservation at 5 years was 66% in previously-hearing patients. The actuarial rate of freedom from trigeminal nerve toxicity was 97% at 5 years. No patient developed facial nerve toxicity or other complications. Conclusion: In this unselected series, fractionated stereotactic radiation therapy and linear accelerator-based radiosurgery give excellent local control in acoustic neuroma. It combines a high rate of preservation of hearing with a very low rate of other toxicity, although follow-up is relatively short

Accumulation of Kv7.2 channels in putative ectopic transduction zones of mice nerve-end neuromas

Directory of Open Access Journals (Sweden)

Lopez-García Jose A

2011-08-01

Full Text Available Abstract Background Modulation of M-type currents has been proposed as a new strategy for the treatment of neuropathic pain due to their role in regulating neuronal excitability. Using electrophysiological techniques we showed previously that the opening of Kv7 channels with retigabine, blocked ectopic discharges from axotomized fibers but did not alter transduction at intact skin afferents. We hypothesized that after nerve damage, accumulation of Kv7 channels in afferent fibers may increase M-type currents which then acquired a more important role at regulating fiber excitability. Findings In this study, we used an immunohistochemical approach to examine patterns of expression of Kv7.2 channels in afferent fibers after axotomy and compared them to patterns of expression of voltage gated Na+ channels (Nav which are key electrogenic elements in peripheral axons known to accumulate in experimental and human neuromas. Axotomy induced an enlargement and narrowing of the nodes of Ranvier at the proximal end of the neuroma together with a dramatic demyelination and loss of structure at its distal end in which naked accumulations of Nav were present. In addition, axotomy also induced accumulations of Kv7.2 that co-localized with those of Nav channels. Conclusions Whilst Nav channels are mandatory for initiation of action potentials, (i.e. responsible for the generation/propagation of ectopic discharges an increased accumulation of Kv7.2 channels after axotomy may represent a homeostatic compensation to over excitability in axotomized fibers, opening a window for a peripheral action of M-current modulators under conditions of neuropathy.

Management of a patient undergoing sitting position craniotomy for acoustic neuroma with co-existing interstitial lung disease

Directory of Open Access Journals (Sweden)

Deepa Suvarna

2015-01-01

Full Text Available A 38-year-old woman with acoustic neuroma associated with occupational interstitial lung disease (ILD was successfully managed for sitting position craniotomy using carefully titrated desflurane-based anaesthesia. The anaesthetic challenges included maintenance an adequate depth of anaesthesia, reducing perioperative airway events and ensuring smooth recovery. While dealing with ILD patient in sitting position, careful risk assessment is important because it will help us predict the course of the perioperative events. Balanced general anaesthesia using desflurane fulfilled the requirement of good depth and smooth recovery in this patient. Though there are reports of maintenance of anaesthesia with other inhalational agents, there are scanty reports of using desflurane in these cases.

MR of acoustic neuromas; Relationship to cranial nerves

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide [Kanazawa Univ. (Japan). School of Medicine

1989-08-01

In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T{sub 1}-weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author).

Prognostic factors for hearing preservation following observation-only versus stereotactic irradiation (STI) in patients with acoustic neuroma

International Nuclear Information System (INIS)

Sakamoto, Tooru

1998-01-01

Prognostic factors for hearing preservation following observation-only versus STI were compared in patients with acoustic neuroma. There were 48 patients with acoustic neuroma treated by fractionated STI. Between 1991 and 1997, patients were given 36 Gy in 20 fractions over 5 weeks (36 Gy/20 Fr/5 wks) to 44 Gy/22 Fr/6 wks followed by a 4 Gy boost. A linear accelerator was used for irradiation. Twenty-three patients with acoustic neuroma who were followed without any treatment (observation-only group) were selected as matched controls. The largest hearing loss was observed at the frequency of 2 kHz in the observation-only group and at 1-2 kHz in the STI group. Hearing loss at lkHz was more frequent in the STI group (p<0.01). There were no significant prognostic factors which predicted hearing preservation in the observation-only group. Stereotactic irradiation has been suggested to damage to cochlear nerve function in patients whose cochlear nerve had been impaired already. Tumor control rate of STI appeared to be as good as single fraction radiosurgery rates in the literature and better than in the observation-only group. Hearing preservation rate in the STI group was as good as in the observation-only group and appeared to be better than single fraction radiosurgery. In conclusion, because there were no factors predictive of hearing preservation in the observation-only group, it is difficult to select patients for observation only. Fractionated STI is potentially the treatment of choice, resulting in the same hearing preservation rate as achieved with observation only, although longer follow-up periods are needed. (author)

Organising haematoma mimicking tumour on MRI following resection of acoustic neuroma

International Nuclear Information System (INIS)

Higgins, J.N.P.; Pigeon, C.N.; Moseley, I.F.

1995-01-01

We describe a 26-year-old woman in whom an enhancing, intradural extramedullary mass was found at the craniocervical junction on MRI 3 years after resection of a large acoustic neuroma. The radiological appearances suggested a new tumour, raising the possibility of neurofibromatosis 2, provoking a review of family members in an attempt to confirm the diagnosis, as well as further surgery. Histology of the lesion revealed an organising haematoma, with no evidence of malignancy. The imaging features can be explained by the process by which blood clot in the subarachnoid space is resorbed. Caution is advised in interpreting CT or MRI after neurosurgery. (orig.)

Environmental risk factors for sporadic acoustic neuroma (Interphone Study Group, Germany)

DEFF Research Database (Denmark)

Schlehofer, B; Schlaefer, K; Blettner, M

2007-01-01

The only known risk factor for sporadic acoustic neuroma is high-dose ionising radiation. Environmental exposures, such as radiofrequency electromagnetic fields and noise are under discussion, as well as an association with allergic diseases. We performed a population-based case-control study.......31; 95% CI 1.15-4.66), and for hay fever (OR=2.20; 95% CI 1.09-4.45), but not for ionising radiation (OR=0.91; 95 % CI 0.51-1.61) or regular mobile phone use (OR=0.67; 95% CI 0.38-1.19). The study confirms results of recently published studies, although the pathogenetic mechanisms are still unknown....

Manual therapy in the management of a patient with a symptomatic Morton's Neuroma: A case report.

Science.gov (United States)

Sault, Josiah D; Morris, Matthew V; Jayaseelan, Dhinu J; Emerson-Kavchak, Alicia J

2016-02-01

Patients with Morton's neuroma are rarely referred to physical therapy. This case reports the resolution of pain, increase in local pressure pain thresholds, and improvement of scores on the Lower Extremity Functional Scale and Foot and Ankle Ability Measure following a course of joint based manual therapy for a patient who had failed standard conservative medical treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Risk of a second cancer from scattered radiation in acoustic neuroma treatment

Science.gov (United States)

Yoon, Myonggeun; Lee, Hyunho; Sung, Jiwon; Shin, Dongoh; Park, Sungho; Chung, Weon Kuu; Jahng, Geon-Ho; Kim, Dong Wook

2014-06-01

The present study aimed to compare the risk of a secondary cancer from scattered and leakage doses in patients receiving intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) of a secondary cancer were estimated using the corresponding secondary doses measured at various organs by using radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, liver, bowel, bladder, prostate (or ovary), and rectum were 14.6, 1.7, 0.9, 0.8, 0.6, 0.6, and 0.6 cGy, respectively, for IMRT whereas they were 19.1, 1.8, 2.0, 0.6, 0.4, 0.4, and 0.4 cGy, respectively, for VMAT, and 22.8, 4.6, 1.4, 0.7, 0.5, 0.5, and 0.5 cGy, respectively, for SRS. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A lifetime attributable risk evaluation estimated that more than 0.03% of acoustic neuroma (AN) patients would get radiation-induced cancer within 20 years of receiving radiation therapy. The organ with the highest radiation-induced cancer risk after radiation treatment for AN was the thyroid. We found that the LAR could be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

Risk of a second cancer from scattered radiation in acoustic neuroma treatment

Energy Technology Data Exchange (ETDEWEB)

Yoon, Myonggeun; Lee, Hyunho; Sung, Jiwon [Korea University, Seoul (Korea, Republic of); Shin, Dongoh [Kyung Hee University Medical Center, Seoul (Korea, Republic of); Park, Sungho [Ulsan University Hospital, Ulsan (Korea, Republic of); Chung, Weonkuu; Jahng, Geonho; Kim, Dongwook [Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of)

2014-06-15

The present study aimed to compare the risk of a secondary cancer from scattered and leakage doses in patients receiving intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) of a secondary cancer were estimated using the corresponding secondary doses measured at various organs by using radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, liver, bowel, bladder, prostate (or ovary), and rectum were 14.6, 1.7, 0.9, 0.8, 0.6, 0.6, and 0.6 cGy, respectively, for IMRT whereas they were 19.1, 1.8, 2.0, 0.6, 0.4, 0.4, and 0.4 cGy, respectively, for VMAT, and 22.8, 4.6, 1.4, 0.7, 0.5, 0.5, and 0.5 cGy, respectively, for SRS. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A lifetime attributable risk evaluation estimated that more than 0.03% of acoustic neuroma (AN) patients would get radiation-induced cancer within 20 years of receiving radiation therapy. The organ with the highest radiation-induced cancer risk after radiation treatment for AN was the thyroid. We found that the LAR could be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

Validation of the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale.

Science.gov (United States)

Lodder, Wouter L; Adan, Guleed H; Chean, Chung S; Lesser, Tristram H; Leong, Samuel C

2017-06-01

The objective of this study is to evaluate the strength of content validity within the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale and to compare how it correlates with a facial dysfunction-specific QOL instrument (Facial Clinimetric Evaluation, FaCE). The study design is online questionnaire survey. Members of the British Acoustic Neuroma Association received both PANQOL questionnaires and the FaCE scale. 158 respondents with self-identified facial paralysis or dysfunction had completed PANQOL and FaCE data sets for analysis. The mean composite PANQOL score was 53.5 (range 19.2-93.5), whilst the mean total FaCE score was 50.9 (range 10-95). The total scores of the PANQOL and FaCE correlated moderate (r = 0.48). Strong correlation (r = 0.63) was observed between the PANQOL's facial dysfunction domain and the FaCE total score. Of all the FaCE domains, social function was strongly correlated with the PANQOL facial dysfunction domain (r = 0.66), whilst there was very weak-to-moderate correlation (range 0.01-0.43) to the other FaCE domains. The current study has demonstrated a strong correlation between the facial dysfunction domains of PANQOL with a facial paralysis-specific QOL instrument.

Acoustic neuromas: single dose vs fractionated therapy

International Nuclear Information System (INIS)

Fuss, M.; Debus, J.; Lohr, F.; Engenhart-Cabillic, R.; Wannenmacher, M.

1997-01-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Intermedius nerve involvement and testing in acoustic neuromas.

Science.gov (United States)

Thomsen, J; Zilstorff, K

1975-01-01

The clinical findings in 125 patients with surgically confirmed acoustic neuromas are presented, with special regard to the involvement of the intermedius nerve in the diagnosis. In assessing the function of the intermedius nerve the examination of the nasolacrimal reflex and the sensation of taste on the anterior two-thirds of the tongue are used. The methods of investigation are described in detail. The material consisted of 20 medium-sized and 105 large tumours; no intracanalicular tumor was found. Hearing loss was the initial symptom in 85% of the patients, 10% had tinitus and 4% vertigo as the first symptom. Apart from the VIII cranial nerve symptoms, a defective nasolacrimal reflex was the most significant evidence of cerebellopontine angle pathology. The test was positive in 65% of the medium-sized tumours, in the entire material, 85%. The figures are higher than the incidence of trigeminal nerve symptoms. This in contrast to the reports of most authors. The tests described are simple and quick to perform, and it is emphasized that they should be applied to all patients with unilateral hearing loss of unknown origin.

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997-2003 and 2007-2009 and use of mobile and cordless phones.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Mild, Kjell Hansson

2013-10-01

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20-80 years, diagnosed during 1997-2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007-2009 including both men and women aged 18-75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0-4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8-21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1-2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8-4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1-2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7-26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1-2.0 increasing to OR = 8.1, 95% CI = 2.0-32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2-9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless phones. OR increased per 100 h

Acoustic neuroma risk in relation to mobile telephone use: Results of the INTERPHONE international case-control study

DEFF Research Database (Denmark)

Berg-Beckhoff, Gabi

2011-01-01

Background: The rapid increase in mobile telephone use has generated concern about possible health risks of radiofrequency electromagnetic fields from these devices. Methods: A case-control study of 1105 patients with newly diagnosed acoustic neuroma (vestibular schwannoma) and 2145 controls...... was conducted in 13 countries using a common protocol. Past mobile phone use was assessed by personal interview. In the primary analysis, exposure time was censored at one year before the reference date (date of diagnosis for cases and date of diagnosis of the matched case for controls); analyses censoring...

Hypofractionated stereotactic radiotherapy of acoustic neuroma. Volume changes and hearing results after 89-month median follow-up

International Nuclear Information System (INIS)

Kranzinger, Manfred; Fastner, Gerd; Zehentmayr, Franz; Sedlmayer, Felix; Oberascher, Gerhard; Merz, Florian; Rahim, Hassan; Nairz, Olaf

2014-01-01

The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity. In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 x 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995). No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9 %) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1 %. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4 %. Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery. (orig.) [de

SU-F-T-611: Critical Analysis and Efficacy of Linac Based (Beam Modulator) and Cyberknife Treatment Plans for Acoustic Neuroma/schwannoma

International Nuclear Information System (INIS)

KP, Karrthick; Kataria, T; Thiyagarajan, R; Selvan, T; Abhishek, A

2016-01-01

Purpose: To study the critical analysis and efficacy of Linac and Cyberknife (CK) treatment plans for acoustic neuroma/schwannoma. Methods: Twelve of acoustic neuroma/schwannoma patients were taken for these study that. Treatment plans were generated in Multiplan treatment planning system (TPS) for CK using 5,7.5 and 10mm diameter collimators. Target volumes were in the range of 0.280 cc to 9.256 cc. Prescription dose (Rx) ranges from 1150cGy to 1950cGy delivered over 1 to 3 Fractions. For same patients stereotactic Volumetric modulated arc plans were generated using Elekta Linac with MLC thickness of 4mm in Monaco TPS. Appropriate calculation algorithms and grid size were used with same Rx and organ at risk (OAR) constrains for both Linac and CK plans. Treatment plans were developed to achieve at least 95% of the target volume to receive the Rx. The dosimetric indices such as conformity index (CI), coverage, OAR dose and volume receiving 50% of Rx (V50%) were used to evaluate the plans. Results: Target volumes ranges from 0.280 cc to 3.5cc shows the CI of 1.16±0.109 and 1.53±0.360 for cyberknife and Linac plans respectively. For small volume targets, the OARs were well spared in CK plans. There are no significant differences in CI and OAR doses were observed between CK and Linac plans that have the target volume >3.5 cc. Perhaps the V50% were lesser in CK plans, and found to be 12.8± 8.4 and 22.8 ± 15.0 for CK and Linac respectively. Conclusion: The analysis shows the importance of collimator size for small volume targets. The target volumes >3.5 cc can be treated in Linac as comparable with CK. For targets <3.5cc CK plans showed superior plan quality with better CI and OAR sparing than the Linac based plans. Further studies may require evaluating the clinical advantage of CK robotic system.

Pooled analysis of case-control studies on acoustic neuroma diagnosed 1997–2003 and 2007–2009 and use of mobile and cordless phones

Science.gov (United States)

HARDELL, LENNART; CARLBERG, MICHAEL; SÖDERQVIST, FREDRIK; MILD, KJELL HANSSON

We previously conducted a case-control study of acoustic neuroma. Subjects of both genders aged 20–80 years, diagnosed during 1997–2003 in parts of Sweden, were included, and the results were published. We have since made a further study for the time period 2007–2009 including both men and women aged 18–75 years selected from throughout the country. These new results for acoustic neuroma have not been published to date. Similar methods were used for both study periods. In each, one population-based control, matched on gender and age (within five years), was identified from the Swedish Population Registry. Exposures were assessed by a self-administered questionnaire supplemented by a phone interview. Since the number of acoustic neuroma cases in the new study was low we now present pooled results from both study periods based on 316 participating cases and 3,530 controls. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index (SEI). Use of mobile phones of the analogue type gave odds ratio (OR) = 2.9, 95% confidence interval (CI) = 2.0–4.3, increasing with >20 years latency (time since first exposure) to OR = 7.7, 95% CI = 2.8–21. Digital 2G mobile phone use gave OR = 1.5, 95% CI = 1.1–2.1, increasing with latency >15 years to an OR = 1.8, 95% CI = 0.8–4.2. The results for cordless phone use were OR = 1.5, 95% CI = 1.1–2.1, and, for latency of >20 years, OR = 6.5, 95% CI = 1.7–26. Digital type wireless phones (2G and 3G mobile phones and cordless phones) gave OR = 1.5, 95% CI = 1.1–2.0 increasing to OR = 8.1, 95% CI = 2.0–32 with latency >20 years. For total wireless phone use, the highest risk was calculated for the longest latency time >20 years: OR = 4.4, 95% CI = 2.2–9.0. Several of the calculations in the long latency category were based on low numbers of exposed cases. Ipsilateral use resulted in a higher risk than contralateral for both mobile and cordless

Associação entre tamanho e potencial proliferativo em neurinomas do acústico Size and proliferative index correlation in acoustic neuromas

Directory of Open Access Journals (Sweden)

Oswaldo Inácio de Tella

2006-03-01

Full Text Available Schwanomas do acústico são os tumores mais freqüentes localizados no ângulo pontocerebelar. Os mecanismos moleculares que levam a sua geração e crescimento ainda não são bem conhecidos. Várias características clínicas, radiológicas e imuno-histoquímicas já foram estudadas e correlacionadas ao crescimento tumoral. Estudamos e correlacionamos aspectos clínicos e imuno-histoquímicos (MIB-1 de 11 schwanomas do acústico operados no Hospital São Paulo/UNIFESP. O tamanho dos tumores correlacionou-se com o índice proliferativo (Ki-67, não havendo correlação com significância estatística entre a idade dos pacientes, duração dos sintomas e índice proliferativo.Acoustic neuromas are the most common tumors in the cerebellopontine angle. The molecular mechanisms involved in generation and growth of these tumors are not completly elucidated. Many radiological, clinic and imunohistochemystry data were correlated to tumor growth. We studied 11 acoustic neuromas surgically treated at Hospital São Paulo/Unifesp and correlated clinical and radiological data with proliferative index (Ki-67. The size of the tumors were positively correlationated with proliferative index. No other correlation had statistic significativity.

Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma

Institute of Scientific and Technical Information of China (English)

LIU Bai-yun; TIAN Yong-ji; LIU Wen; LIU Shu-ling; QIAO Hui; ZHANG Jun-ting; JIA Gui-jun

2007-01-01

Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function.Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation (TCEMEP) for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed.Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis (H-B grade 3), and 5 had mild facial paralysis (H-B grade 2). In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal.Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.

Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): Long-term results in 106 patients treated in a single institution

International Nuclear Information System (INIS)

Combs, Stephanie E.; Volk, Sigrid; Schulz-Ertner, Daniela; Huber, Peter E.; Thilmann, Christoph; Debus, Juergen

2005-01-01

Purpose: To assess the long-term outcome and toxicity of fractionated stereotactic radiotherapy for acoustic neuromas in 106 patients treated in a single institution. Patients and Methods: Between October 1989 and January 2004, fractionated stereotactic radiotherapy (FSRT) was performed in 106 patients with acoustic neuroma (AN). The median total dose applied was 57.6 Gy in median single fractions of 1.8 Gy in five fractions per week. The median irradiated tumor volume was 3.9 mL (range, 2.7-30.7 mL). The median follow-up time was 48.5 months (range, 3-172 months). Results: Fractionated stereotactic radiotherapy was well tolerated in all patients. Actuarial local tumor control rates at 3- and 5- years after FSRT were 94.3% and 93%, respectively. Actuarial useful hearing preservation was 94% at 5 years. The presence of neurofibromatosis (NF-2) significantly adversely influenced hearing preservation in patients that presented with useful hearing at the initiation of RT (p = 0.00062). Actuarial hearing preservation without the diagnosis of NF-2 was 98%. In cases with NF-2, the hearing preservation rate was 64%. Cranial nerve toxicity other than hearing impairment was rare. The rate of radiation induced toxicity to the trigeminal and facial nerve was 3.4% and 2.3%, respectively. Conclusion: Fractionated stereotactic radiotherapy is safe and efficacious for the treatment of AN, with mild toxicity with regard to hearing loss and cranial nerve function. FSRT might be considered as an equieffective treatment modality compared to neurosurgery and therefore represents an interesting alternative therapy for patients with AN

Percutaneous MR-Guided Cryoablation of Morton’s Neuroma: Rationale and Technical Details After the First 20 Patients

International Nuclear Information System (INIS)

Cazzato, Roberto Luigi; Garnon, Julien; Ramamurthy, Nitin; Tsoumakidou, Georgia; Caudrelier, Jean; Thenint, Marie-Aude; Rao, Pramod; Koch, Guillaume; Gangi, Afshin

2016-01-01

ObjectivesThe purpose of this study is to discuss technical aspects and rationales of magnetic resonance (MR)-guided cryoablation (CA) of Morton’s neuroma (MN); preliminary clinical experience is also retrospectively reviewed.MethodsProcedures were performed under local anaesthesia on an outpatient basis. Lesion size and location, procedural (technical success, procedural time, complications) and clinical outcomes (patient satisfaction according to a four-point scale, residual pain according to a 0–10 visual analogue scale and instances of “stump neuroma”) were assessed via chart review and cross-sectional telephone survey after the 20th case.ResultsTwenty patients (15 female, 5 male; mean age 50.3 years) were included; 24 MN (mean size 12.7 mm) were treated. Technical success was 100 %. Mean procedural time was 40.9 ± 10.4 min (range 35–60). One minor complication (superficial cellulitis) was reported (4.2 %). Follow-up (mean 19.7 months) was available for 18/24 MN. Patient satisfaction on a per-lesion basis was as follows: “completely satisfied” in 77.7 %, “satisfied with minor reservations” in 16.6 % and “satisfied with major reservations” in 5.7 % of cases. Mean pain score at last follow-up post-CA was 3.0. No instances of “stump neuroma” were reported.ConclusionsMR-guided CA of MN is a novel therapy which appears technically feasible. Clinical advantages of the procedure are high patient satisfaction, reduced risk of “stump neuroma” syndrome and good patient tolerance on an outpatient basis. Further, prospective studies are needed to confirm these encouraging results.

Percutaneous MR-Guided Cryoablation of Morton’s Neuroma: Rationale and Technical Details After the First 20 Patients

Energy Technology Data Exchange (ETDEWEB)

Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Garnon, Julien [Hôpitaux Universitaires de Strasbourg, HUS (France); Department of Interventional Radiology, Nouvel Hôpital Civil (France); Ramamurthy, Nitin [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Tsoumakidou, Georgia; Caudrelier, Jean; Thenint, Marie-Aude; Rao, Pramod; Koch, Guillaume; Gangi, Afshin [Hôpitaux Universitaires de Strasbourg, HUS (France); Department of Interventional Radiology, Nouvel Hôpital Civil (France)

2016-10-15

ObjectivesThe purpose of this study is to discuss technical aspects and rationales of magnetic resonance (MR)-guided cryoablation (CA) of Morton’s neuroma (MN); preliminary clinical experience is also retrospectively reviewed.MethodsProcedures were performed under local anaesthesia on an outpatient basis. Lesion size and location, procedural (technical success, procedural time, complications) and clinical outcomes (patient satisfaction according to a four-point scale, residual pain according to a 0–10 visual analogue scale and instances of “stump neuroma”) were assessed via chart review and cross-sectional telephone survey after the 20th case.ResultsTwenty patients (15 female, 5 male; mean age 50.3 years) were included; 24 MN (mean size 12.7 mm) were treated. Technical success was 100 %. Mean procedural time was 40.9 ± 10.4 min (range 35–60). One minor complication (superficial cellulitis) was reported (4.2 %). Follow-up (mean 19.7 months) was available for 18/24 MN. Patient satisfaction on a per-lesion basis was as follows: “completely satisfied” in 77.7 %, “satisfied with minor reservations” in 16.6 % and “satisfied with major reservations” in 5.7 % of cases. Mean pain score at last follow-up post-CA was 3.0. No instances of “stump neuroma” were reported.ConclusionsMR-guided CA of MN is a novel therapy which appears technically feasible. Clinical advantages of the procedure are high patient satisfaction, reduced risk of “stump neuroma” syndrome and good patient tolerance on an outpatient basis. Further, prospective studies are needed to confirm these encouraging results.

Probabilistic Multiple-Bias Modeling Applied to the Canadian Data From the Interphone Study of Mobile Phone Use and Risk of Glioma, Meningioma, Acoustic Neuroma, and Parotid Gland Tumors.

Science.gov (United States)

Momoli, F; Siemiatycki, J; McBride, M L; Parent, M-É; Richardson, L; Bedard, D; Platt, R; Vrijheid, M; Cardis, E; Krewski, D

2017-10-01

We undertook a re-analysis of the Canadian data from the 13-country case-control Interphone Study (2001-2004), in which researchers evaluated the associations of mobile phone use with the risks of brain, acoustic neuroma, and parotid gland tumors. In the main publication of the multinational Interphone Study, investigators concluded that biases and errors prevented a causal interpretation. We applied a probabilistic multiple-bias model to address possible biases simultaneously, using validation data from billing records and nonparticipant questionnaires as information on recall error and selective participation. In our modeling, we sought to adjust for these sources of uncertainty and to facilitate interpretation. For glioma, when comparing those in the highest quartile of use (>558 lifetime hours) to those who were not regular users, the odds ratio was 2.0 (95% confidence interval: 1.2, 3.4). After adjustment for selection and recall biases, the odds ratio was 2.2 (95% limits: 1.3, 4.1). There was little evidence of an increase in the risk of meningioma, acoustic neuroma, or parotid gland tumors in relation to mobile phone use. Adjustments for selection and recall biases did not materially affect interpretation in our results from Canadian data. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

SU-E-T-208: Incidence Cancer Risk From the Radiation Treatment for Acoustic Neuroma Patient

Energy Technology Data Exchange (ETDEWEB)

Kim, D [Kyung Hee University International Med. Serv., Seoul (Korea, Republic of); Chung, W [Kyung Hee University Hospital at Gangdong, Seoul, Seoul (Korea, Republic of); Shin, D [Kyung Hee University Hospital, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

2014-06-01

Purpose: The present study aimed to compare the incidence risk of a secondary cancer from therapeutic doses in patients receiving intensitymodulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Methods: Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their incidnece excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were estimated using the corresponding therapeutic doses measured at various organs by radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. Results: When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, normal liver, colon, bladder, prostate (or ovary), and rectum were measured. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A LAR were estimated that more than 0.03% of AN patients would get radiation-induced cancer. Conclusion: The tyroid was highest radiation-induced cancer risk after radiation treatment for AN. We found that LAR can be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

Distal anterior inferior cerebellar artery syndrome after acoustic neuroma surgery.

Science.gov (United States)

Hegarty, Joseph L; Jackler, Robert K; Rigby, Peter L; Pitts, Lawrence H; Cheung, Steven W

2002-07-01

To define a clinicopathologic syndrome associated with persistent cerebellar dysfunction after acoustic neuroma (AN) excision. Case series derived from radiographic and clinical chart review. Tertiary referral center. In 12 patients with AN, persistent cerebellar dysfunction developed after AN removal. Each case demonstrated abnormality in the ipsilateral cerebellar peduncle on postoperative magnetic resonance imaging. Cerebellar function and ambulatory status over the first postoperative year. On magnetic resonance imaging scans, the extent of cerebellar peduncle infarcts was variable. It ranged from focal brain injury (2 cm) spanning the full thickness of the peduncle. Peduncular infarcts were associated with large tumor size (average 3.8 cm, range 2.0-5.5 cm diameter). The long-term functional outcomes (>1 yr) varied. Dysmetria was unchanged or improved in over half of the patients (6 of 11 patients). Gait recovered to normal or to preoperative levels in 5 patients. In the 6 patients with persistent impaired mobility, 2 had mild gait disturbance, 3 required regular use of a cane, and 1 has been dependent on a walker. One patient had sustained mild motor weakness. Three of 11 patients remained dependent on others for activities of daily living. Peduncle injury most likely stems from interruption of distal branches of the anterior inferior cerebellar artery (AICA). These small vessels are intimately related to the capsule of the tumor and may supply both the neoplasm and the brain parenchyma. It has long been recognized that interruption of the proximal segment of the AICA results in severe injury to the pons, with devastating neurologic sequelae. A limited AICA syndrome caused by loss of its distal ramifications seems a more plausible explanation for peduncular infarction than either venous insufficiency or direct surgical trauma.

Observations at the CNS-PNS border of ventral roots connected to a neuroma

Directory of Open Access Journals (Sweden)

Sten Remahl

2010-10-01

Full Text Available Previous studies have shown that numerous sprouts originating from a neuroma, after nerve injury in neonatal animals, can invade spinal nerve roots. In this study the border between the central and peripheral nervous system (CNS-PNS border of ventral roots in kittens was examined with both light and electron microscopy after early postnatal sciatic nerve resection. A transient ingrowth of substance P positive axons was observed into the CNS, but no spouts remained 6 weeks after the injury. Using serial sections and electron microscopy it was possible to identify small bundles of unmyelinated axons that penetrated from the root fascicles for a short distance into the CNS. These axons ended blindly, sometimes with a growth cone-like terminal swelling filled with vesicles. The axon bundles were accompanied by p75 positive cells in both the root fascicles and the pia mater, but not in the CNS. It may thus be suggested that neurotrophin presenting p75 positive cells could facilitate axonal growth into the pia mater and that the lack of such cells in the CNS compartment might contribute to the failure of growth into the CNS. A maldevelopment of myelin sheaths at the CNS-PNS border of motor axons was observed and it seems possible that this could have consequences for the propagation of action potential across this region after neonatal nerve injury.

Occupation and risk of glioma, meningioma and acoustic neuroma: results from a German case-control study (interphone study group, Germany)

DEFF Research Database (Denmark)

Samkange-Zeeb, F; Schlehofer, B; Schüz, J

2010-01-01

/electronic and transport, and the risk of glioma, meningioma and acoustic neuroma. METHODS: In a population-based case-control study involving a total of 844 cases and 1688 controls conducted from 2000 to 2003, detailed information on life-long job histories was collected during personal interviews and used to create job...... calendars for each participant. Job title, job activity, job number, and the starting and ending dates of the activity were recorded for all activities with duration of at least 1 year. Reported occupational activities were coded according to the International Standard Classification of Occupations 1988...... (ISCO 88). For the analyses we focused on six a priori defined occupational sectors, namely chemical, metal, agricultural, construction, electrical/electronic and transport. Multiple conditional logistic regression analysis was used to estimate odds ratios and their 95% confidence intervals. RESULTS...

Use of piezosurgery for internal auditory canal drilling in acoustic neuroma surgery.

Science.gov (United States)

Grauvogel, Juergen; Scheiwe, Christian; Kaminsky, Jan

2011-10-01

Piezosurgery is based on microvibrations generated by the piezoelectrical effect and has a selective bone-cutting ability with preservation of soft tissue. This study examined the applicability of Piezosurgery compared to rotating drills (RD) for internal auditory canal (IAC) opening in acoustic neuroma (AN) surgery. Piezosurgery was used in eight patients for IAC drilling in AN surgery. After exposition of the IAC and tumor, the posterior wall of the IAC was drilled using Piezosurgery instead of RD. Piezosurgery was evaluated with respect to practicability, safety, preciseness of bone cutting, preservation of cranial nerves, influences on neurophysiological monitoring, and facial nerve and hearing outcome. Piezosurgery was successfully used for selective bone cutting, while cranial nerves were structurally and functionally preserved, which could be measured by means of neuromonitoring. Piezosurgery guaranteed a safe and precise cut by removing bone layer by layer in a shaping way. Compared to RD, limited influence on neurophysiological monitoring attributable to Piezosurgery was noted, allowing for continuous neuromonitoring. No disadvantage due to microvibrations was noticed concerning hearing function. The angled tip showed better handling in right-sided than in left-sided tumors in the hands of a right-handed surgeon. The short, thick handpiece may be improved for more convenient handling. Piezosurgery is a safe tool for selective bone cutting for opening of the IAC with preservation of facial nerve and hearing function in AN surgery. Piezosurgery has the potential to replace RD for this indication because of its safe and precise bone-cutting properties.

Use of mobile phones and cordless phones is associated with increased risk for glioma and acoustic neuroma.

Science.gov (United States)

Hardell, Lennart; Carlberg, Michael; Hansson Mild, Kjell

2013-04-01

The International Agency for Research on Cancer (IARC) at WHO evaluation of the carcinogenic effect of RF-EMF on humans took place during a 24-31 May 2011 meeting at Lyon in France. The Working Group consisted of 30 scientists and categorised the radiofrequency electromagnetic fields from mobile phones, and from other devices that emit similar non-ionising electromagnetic fields (RF-EMF), as Group 2B, i.e., a 'possible', human carcinogen. The decision on mobile phones was based mainly on the Hardell group of studies from Sweden and the IARC Interphone study. We give an overview of current epidemiological evidence for an increased risk for brain tumours including a meta-analysis of the Hardell group and Interphone results for mobile phone use. Results for cordless phones are lacking in Interphone. The meta-analysis gave for glioma in the most exposed part of the brain, the temporal lobe, odds ratio (OR)=1.71, 95% confidence interval (CI)=1.04-2.81 in the ≥10 years (>10 years in the Hardell group) latency group. Ipsilateral mobile phone use ≥1640h in total gave OR=2.29, 95% CI=1.56-3.37. The results for meningioma were OR=1.25, 95% CI=0.31-4.98 and OR=1.35, 95% CI=0.81-2.23, respectively. Regarding acoustic neuroma ipsilateral mobile phone use in the latency group ≥10 years gave OR=1.81, 95% CI=0.73-4.45. For ipsilateral cumulative use ≥1640h OR=2.55, 95% CI=1.50-4.40 was obtained. Also use of cordless phones increased the risk for glioma and acoustic neuroma in the Hardell group studies. Survival of patients with glioma was analysed in the Hardell group studies yielding in the >10 years latency period hazard ratio (HR)=1.2, 95% CI=1.002-1.5 for use of wireless phones. This increased HR was based on results for astrocytoma WHO grade IV (glioblastoma multiforme). Decreased HR was found for low-grade astrocytoma, WHO grades I-II, which might be caused by RF-EMF exposure leading to tumour-associated symptoms and earlier detection and surgery with better

Test sensitivity is important for detecting variability in pointing comprehension in canines.

Science.gov (United States)

Pongrácz, Péter; Gácsi, Márta; Hegedüs, Dorottya; Péter, András; Miklósi, Adám

2013-09-01

Several articles have been recently published on dogs' (Canis familiaris) performance in two-way object choice experiments in which subjects had to find hidden food by utilizing human pointing. The interpretation of results has led to a vivid theoretical debate about the cognitive background of human gestural signal understanding in dogs, despite the fact that many important details of the testing method have not yet been standardized. We report three experiments that aim to reveal how some procedural differences influence adult companion dogs' performance in these tests. Utilizing a large sample in Experiment 1, we provide evidence that neither the keeping conditions (garden/house) nor the location of the testing (outdoor/indoor) affect a dogs' performance. In Experiment 2, we compare dogs' performance using three different types of pointing gestures. Dogs' performance varied between momentary distal and momentary cross-pointing but "low" and "high" performer dogs chose uniformly better than chance level if they responded to sustained pointing gestures with reinforcement (food reward and a clicking sound; "clicker pointing"). In Experiment 3, we show that single features of the aforementioned "clicker pointing" method can slightly improve dogs' success rate if they were added one by one to the momentary distal pointing method. These results provide evidence that although companion dogs show a robust performance at different testing locations regardless of their keeping conditions, the exact execution of the human gesture and additional reinforcement techniques have substantial effect on the outcomes. Consequently, researchers should standardize their methodology before engaging in debates on the comparative aspects of socio-cognitive skills because the procedures they utilize may differ in sensitivity for detecting differences.

Lingual nerve injury in third molar surgery I. Observations on recovery of sensation with spontaneous healing

DEFF Research Database (Denmark)

Hillerup, S; Stoltze, Kaj

2007-01-01

, thermal stimuli and location of stimulus, as well as two-point discrimination, pain and the presence of a neuroma at the lesion site. Neurogenic signs and symptoms related to the injury and their variation over time were registered. Females were more often referred than males. Most lingual nerve injuries...... exhibited a significant potential for recovery, but only a few patients made a full recovery with absence of neurogenic symptoms. The recovery rate was highest during the first 6 months. Recovery was not influenced by gender, and only slightly by age. The presence of a neuroma was associated with a more...

Point kinetics equations for subcritical systems based on the importance function associated to an external neutron source

International Nuclear Information System (INIS)

Carvalho Gonçalves, Wemerson de; Martinez, Aquilino Senra; Carvalho da Silva, Fernando

2015-01-01

Highlights: • We define the new function importance. • We calculate the kinetic parameters Λ, β, Γ and Q to: 0.95, 0.96, 0.97, 0.98 and 0.99. • We compared the results with those obtained by the main important functions. • We found that the calculated kinetic parameters are physically consistent. - Abstract: This paper aims to determine the parameters for a new set of equations of point kinetic subcritical systems, based on the concept of importance of Heuristic Generalized Perturbation Theory (HGPT). The importance function defined here is related to both the subcriticality and the external neutron source worth (which keeps the system at steady state). The kinetic parameters defined in this work are compared with the corresponding parameters when adopting the importance functions proposed by Gandini and Salvatores (2002), Dulla et al. (2006) and Nishihara et al. (2003). Furthermore, the point kinetics equations developed here are solved for two different transients, considering the parameters obtained with different importance functions. The results collected show that there is a similar behavior of the solution of the point kinetics equations, when used with the parameters obtained by the importance functions proposed by Gandini and Salvatores (2002) and Dulla et al. (2006), specially near the criticality. However, this is not verified as the system gets farther from criticality

Validation of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) for Spanish-Speaking Patients.

Science.gov (United States)

Medina, Maria Del Mar; Carrillo, Alvaro; Polo, Ruben; Fernandez, Borja; Alonso, Daniel; Vaca, Miguel; Cordero, Adela; Perez, Cecilia; Muriel, Alfonso; Cobeta, Ignacio

2017-04-01

Objective To perform translation, cross-cultural adaptation, and validation of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) to the Spanish language. Study Design Prospective study. Setting Tertiary neurotologic referral center. Subjects and Methods PANQOL was translated and translated back, and a pretest trial was performed. The study included 27 individuals diagnosed with vestibular schwannoma. Inclusion criteria were adults with untreated vestibular schwannoma, diagnosed in the past 12 months. Feasibility, internal consistency, test-retest reliability, construct validity, and ceiling and floor effects were assessed for the present study. Results The mean overall score of the PANQOL was 69.21 (0-100 scale, lowest to highest quality of life). Cronbach's α was 0.87. Intraclass correlation coefficient was performed for each item, with an overall score of 0.92. The κ coefficient scores were between moderate and almost perfect in more than 92% of patients. Anxiety and energy domains of the PANQOL were correlated with both physical and mental components of the SF-12. Hearing, balance, and pain domains were correlated with the SF-12 physical component. Facial and general domains were not significantly correlated with any component of the SF-12. Furthermore, the overall score of the PANQOL was correlated with the physical component of the SF-12. Conclusion Feasibility, internal consistency, reliability, and construct validity outcomes in the current study support the validity of the Spanish version of the PANQOL.

[The different point of view about the sanitary control of importation of psychotropic substances in Brazil].

Science.gov (United States)

Sebastião, Patrícia Cristina Antunes; Lucchese, Geraldo

2010-11-01

The purpose of this work is to analyze the process of importation, that is a part of the sanitary control of psychotropic substances, made by Brazilian National Health Surveillance Agency's ports, airports and borders. For this work, psychotropic substances are defined as active pharmaceutical raw materials present in the list B1 of Portaria nº 344/98; which need Anvisa's permission to be imported. For this purpose we used semistructured interviews with key informers and participant observation. The information were collected and systematized through the content analysis, thematic modality. The results show a very complex control which involves an intense bureaucratic process. The main identified critical points of the process were: the information system precariousness; the absence of human resources; deficiency of laboratorial support and infra-structure at customs. Anvisa's web page and the specific law are strong points of the process, but still needing improvements. We understood that despite of the progress made, there are many things to do for giving the country an efficient health control system to the importation of these substances.

Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus

International Nuclear Information System (INIS)

Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

2011-01-01

Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

Hypofractionated stereotactic radiotherapy of acoustic neuroma. Volume changes and hearing results after 89-month median follow-up

Energy Technology Data Exchange (ETDEWEB)

Kranzinger, Manfred; Fastner, Gerd [Paracelsus Medical University Clinics (PMU), University Clinic of Radiotherapy and Radio-Oncology, Salzburg County Hospital, Salzburg (Austria); Zehentmayr, Franz; Sedlmayer, Felix [Paracelsus Medical University Clinics (PMU), University Clinic of Radiotherapy and Radio-Oncology, Salzburg County Hospital, Salzburg (Austria); Salzburg County Hospital, Paracelsus Medical University Clinics, radART - Institute for Research and Development on Advanced Radiation Technologies, Salzburg (Austria); Oberascher, Gerhard [Paracelsus Medical University Clinics (PMU), University Clinic of Ear, Nose and Throat Diseases, Salzburg County Hospital, Salzburg (Austria); Merz, Florian; Rahim, Hassan [Salzburg County Hospital, Paracelsus Medical University Clinics, Medical Radiation Protection Unit, Salzburg (Austria); Nairz, Olaf [Clinic Bad Trissl, Oberaudorf (Germany)

2014-09-15

The goal of this work was to evaluate toxicity and local control following hypofractionated stereotactic radiation treatment with special focus on changes in tumor volume and hearing capacity. In all, 29 patients with unilateral acoustic neuroma were treated between 2001 and 2007 within a prospective radiation protocol (7 x 4 Gy ICRU dose). Median tumor volume was 0.9 ml. Follow-up started at 6 months and was repeated annually with MRI volumetry and audiometry. Hearing preservation was defined as preservation of Class A/B hearing according to the guidelines of the American Academy of Otolaryngology (1995). No patient had any intervention after a median imaging follow-up of 89.5 months, one patient showed radiological progression. Transient increase of tumor volume developed in 17/29 patients, whereas 22/29 patients (75.9 %) presented with a volume reduction at last follow-up. A total of 21 patients were eligible for hearing evaluation. Mean pure tone average (PTA) deteriorated from 39.3 to 65.9 dB and mean speech discrimination score (SDS) dropped from 74.3 to 38.1 %. The 5-year actuarial Class A/B hearing preservation rate was 50.0 ± 14.4 %. Radiation increases only minimally, if at all, the hearing deterioration which emerges by observation alone. Presbyacusis is not responsible for this deterioration. Transient tumor enlargement is common. Today radiation of small- and medium-sized acoustic neuroma can be performed with different highly conformal techniques as fractionated treatment or single low-dose radiosurgery with equal results regarding tumor control, hearing preservation, and side effects. Hypofractionation is more comfortable for the patient than conventional regimens and represents a serious alternative to frameless radiosurgery. (orig.) [German] Ziel der Studie war die Evaluierung der Toxizitaet und der lokalen Tumorkontrolle einer hypofraktionierten stereotaktischen Bestrahlung mit besonderem Augenmerk auf Veraenderungen von Tumorvolumen und

Important points not mentioned in 'interim report' of nuclear regulation authority

International Nuclear Information System (INIS)

Sato, Satoshi

2014-01-01

The Nuclear Regulation Authority (NRA) published the investigation and examination report on the unexplained issues raised by the National Diet Investigation Commission; 'Analysis of the TEPCO Fukushima Daiichi NPS Accident-Interim Report' in October 2014. The NRA had analyzed seven unexplained issues raised in the National Diet Investigation Commission report, and compiled the results. The author insisted the report should include related views and lessons learned and not just explain investigated and examined phenomena in order to contribute to ensuring nuclear safety in the world. As an example, the author selected the fifth of seven issues; 'operating status of the Isolation Condenser of Unit 1 (IC)'. The report concluded 'the AC-driven valve was closed since the AC power supply kept working even after DC power supply for the IC rupture detection circuit was lost. The isolation valves (2A and 2B) outside the PCV were closed, but isolation valves (1B and 4B) of the IC (system 'B') in the PCV remained open. However, the operating status (open/close) of isolation valves (1A and 4A) of the IC (system 'A') in the PCV is not clear. It is therefore necessary to continue analyses of this issue.' As related important points not mentioned in the report, the author described five points; (1) timing of functional losses of IC system, (2) obsolete aspect of equipment arrangement design (system separation), (3) single failure vulnerability, (4) rolling out issue of IC system to RCIC system (horizontal deployment) and (5) lessons learned from risk-informed 'black swan event'. (T. Tanaka)

Multistep translation and cultural adaptation of the Penn acoustic neuroma quality-of-life scale for German-speaking patients.

Science.gov (United States)

Kristin, Julia; Glaas, Marcel Fabian; Stenin, Igor; Albrecht, Angelika; Klenzner, Thomas; Schipper, Jörg; Eysel-Gosepath, Katrin

2017-11-01

Monitoring the health-related quality of life (HRQOL) for patients with vestibular schwannoma (VS) has garnered increasing interest. In German-speaking countries, there is no disease-specific questionnaire available similar to the "Penn Acoustic Neuroma Quality-of-life Scale" (PANQOL). We translated the PANQOL for German-speaking patients based on a multistep protocol that included not only a forward-backward translation but also linguistic and sociocultural adaptations. The process consists of translation, synthesis, back translation, review by an expert committee, administration of the prefinal version to our patients, submission and appraisal of all written documents by our research team. The required multidisciplinary team for translation comprised head and neck surgeons, language professionals (German and English), a professional translator, and bilingual participants. A total of 123 patients with VS underwent microsurgical procedures via different approaches at our clinic between January 2007 and January 2017. Among these, 72 patients who underwent the translabyrinthine approach participated in the testing of the German-translated PANQOL. The first German version of the PANQOL questionnaire was created by a multistep translation process. The responses indicate that the questionnaire is simple to administer and applicable to our patients. The use of a multistep process to translate quality-of-life questionnaires is complex and time-consuming. However, this process was performed properly and resulted in a version of the PANQOL for assessing the quality of life of German-speaking patients with VS.

Importance of point-by-point back projection correction for isocentric motion in digital breast tomosynthesis: Relevance to morphology of structures such as microcalcifications

International Nuclear Information System (INIS)

Chen Ying; Lo, Joseph Y.; Dobbins, James T. III

2007-01-01

Digital breast tomosynthesis is a three-dimensional imaging technique that provides an arbitrary set of reconstruction planes in the breast from a limited-angle series of projection images acquired while the x-ray tube moves. Traditional shift-and-add (SAA) tomosynthesis reconstruction is a common mathematical method to line up each projection image based on its shifting amount to generate reconstruction slices. With parallel-path geometry of tube motion, the path of the tube lies in a plane parallel to the plane of the detector. The traditional SAA algorithm gives shift amounts for each projection image calculated only along the direction of x-ray tube movement. However, with the partial isocentric motion of the x-ray tube in breast tomosynthesis, small objects such as microcalcifications appear blurred (for instance, about 1-4 pixels in blur for a microcalcification in a human breast) in traditional SAA images in the direction perpendicular to the direction of tube motion. Some digital breast tomosynthesis algorithms reported in the literature utilize a traditional one-dimensional SAA method that is not wholly suitable for isocentric motion. In this paper, a point-by-point back projection (BP) method is described and compared with traditional SAA for the important clinical task of evaluating morphology of small objects such as microcalcifications. Impulse responses at different three-dimensional locations with five different combinations of imaging acquisition parameters were investigated. Reconstruction images of microcalcifications in a human subject were also evaluated. Results showed that with traditional SAA and 45 deg. view angle of tube movement with respect to the detector, at the same height above the detector, the in-plane blur artifacts were obvious for objects farther away from x-ray source. In a human subject, the appearance of calcifications was blurred in the direction orthogonal to the tube motion with traditional SAA. With point-by-point BP, the

The importance of topographically corrected null models for analyzing ecological point processes.

Science.gov (United States)

McDowall, Philip; Lynch, Heather J

2017-07-01

Analyses of point process patterns and related techniques (e.g., MaxEnt) make use of the expected number of occurrences per unit area and second-order statistics based on the distance between occurrences. Ecologists working with point process data often assume that points exist on a two-dimensional x-y plane or within a three-dimensional volume, when in fact many observed point patterns are generated on a two-dimensional surface existing within three-dimensional space. For many surfaces, however, such as the topography of landscapes, the projection from the surface to the x-y plane preserves neither area nor distance. As such, when these point patterns are implicitly projected to and analyzed in the x-y plane, our expectations of the point pattern's statistical properties may not be met. When used in hypothesis testing, we find that the failure to account for the topography of the generating surface may bias statistical tests that incorrectly identify clustering and, furthermore, may bias coefficients in inhomogeneous point process models that incorporate slope as a covariate. We demonstrate the circumstances under which this bias is significant, and present simple methods that allow point processes to be simulated with corrections for topography. These point patterns can then be used to generate "topographically corrected" null models against which observed point processes can be compared. © 2017 by the Ecological Society of America.

Vestibular schwannoma (acoustic neuroma mimicking temporomandibular disorders: a case report Schwannoma vestibular (neurinoma do acústico imitando desordens temporomandibulares: um relato de caso

Directory of Open Access Journals (Sweden)

Maurício A. Bisi

2006-12-01

Full Text Available Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma. Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case.Aproximadamente 6 a 16% dos pacientes com sintomas de neuralgia trigeminal apresentam tumores intracranianos, sendo mais comum o schwannoma vestibular (neurinoma do acústico. Alguns sintomas relatados pelos pacientes são perda da audição, zumbido, dores de cabeça, vertigens e distúrbios trigeminais. Uma resposta muscular aumentada na musculatura associada da cabeça e do pescoço também pode ser observada, o que pode mimetizar sinais e sintomas de desordens temporomandibulares. Nestes casos é de grande valia o uso de imagem de ressonância magnética (IRM para detecção de tumores. É importante, também, a diferenciação de dores miofasciais e neurálgicas, pois ambas podem apresentar características semelhantes, mas com origens e tratamentos diferentes. O objetivo desse trabalho foi demonstrar através de relato de caso clínico a associação entre sintomas de neuralgia trigeminal, tumores intracranianos e disfunção temporomandibular.

Selective Denervation for Persistent Knee Pain After Total Knee Arthroplasty: A Report of 50 Cases.

Science.gov (United States)

Shi, Shao-Min; Meister, David W; Graner, Kelly C; Ninomiya, James T

2017-03-01

Despite the general success of total knee arthroplasty (TKA), up to 20% of patients report dissatisfaction following surgery. One potential cause of this dissatisfaction is residual pain secondary to neuroma formation in the sensory nerve branches that innervate the knee. We found, after performing a retrospective review, that up to 9.7% of patients following primary TKA and up to 21% of revision cases exhibited persistent knee pain attributable to neuroma formation. Despite the high incidence of this pathology, little is known about the effective diagnosis or treatment of neuroma formation following TKA. Between 2011 and 2014, 50 patients with persistent symptomatic neuroma pain following TKA underwent selective denervation. These patients had demonstrated the appropriate selection criteria and had failed conservative management. Patients were evaluated by the visual analog scale pain score and the Knee Society Score to determine the outcome of the described treatment. Thirty-two patients (64%) rated their outcome as excellent, 10 (20%) as good, 3 (6%) as fair, and 2 (4%) reported no change. The mean visual analog scale pain score was improved from 9.4 ± 0.8 to 1.1 ± 1.6 following surgery (P ≤ .001). The mean Knee Society Scores increased from 45.5 ± 14.3 to 94.1 ± 8.6 points (P ≤ .0001). Three patients (6%) required the second neurectomy due to recurrent pain and received excellent pain relief postoperatively. There were 2 complications of superficial skin peri-incisional hyperemia related to dressings. Average follow-up duration was 24 months (range, 16-38 months). Our study suggests that selective denervation provides an effective and long-lasting option for the management of this pathology. Copyright © 2016 Elsevier Inc. All rights reserved.

Automated gamma knife radiosurgery treatment planning with image registration, data-mining, and Nelder-Mead simplex optimization

International Nuclear Information System (INIS)

Lee, Kuan J.; Barber, David C.; Walton, Lee

2006-01-01

Gamma knife treatments are usually planned manually, requiring much expertise and time. We describe a new, fully automatic method of treatment planning. The treatment volume to be planned is first compared with a database of past treatments to find volumes closely matching in size and shape. The treatment parameters of the closest matches are used as starting points for the new treatment plan. Further optimization is performed with the Nelder-Mead simplex method: the coordinates and weight of the isocenters are allowed to vary until a maximally conformal plan specific to the new treatment volume is found. The method was tested on a randomly selected set of 10 acoustic neuromas and 10 meningiomas. Typically, matching a new volume took under 30 seconds. The time for simplex optimization, on a 3 GHz Xeon processor, ranged from under a minute for small volumes ( 30 000 cubic mm,>20 isocenters). In 8/10 acoustic neuromas and 8/10 meningiomas, the automatic method found plans with conformation number equal or better than that of the manual plan. In 4/10 acoustic neuromas and 5/10 meningiomas, both overtreatment and undertreatment ratios were equal or better in automated plans. In conclusion, data-mining of past treatments can be used to derive starting parameters for treatment planning. These parameters can then be computer optimized to give good plans automatically

Peripheral tumor and tumor-like neurogenic lesions

Energy Technology Data Exchange (ETDEWEB)

Abreu, Evandro [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France); Aubert, Sébastien, E-mail: sebastien.aubert@chru-lille.fr [Institut de Pathologie, Centre de Biologie-Pathologie, CHRU de Lille, 59037 Lille (France); Wavreille, Guillaume, E-mail: guillaume.wavreille@chru-lille.fr [Service d’Orthopédie B, Hôpital R Salengro, CHRU de Lille, 59037 Lille (France); Gheno, Ramon; Canella, Clarissa [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France); Cotten, Anne, E-mail: anne.cotten@chru-lille.fr [Service de Radiologie et Imagerie Musculosquelettique, Centre de Consultation et Imagerie de l’Appareil Locomoteur, CHRU de Lille, 59037 Lille (France)

2013-01-15

Neoplasms of neurogenic origin account for about 12% of all benign and 8% of all malignant soft tissue neoplasms. Traumatic neuroma, Morton neuroma, lipomatosis of a nerve, nerve sheath ganglion, perineurioma, benign and malignant peripheral nerve sheath tumors (PNST) are included in this group of pathologies. Clinical and radiologic evaluation of patients with neurogenic tumors and pseudotumors often reveals distinctive features. In this context, advanced imaging techniques, especially ultrasound (US) and magnetic resonance (MR) play an important role in the characterization of these lesions. Imaging findings such as location of a soft tissue mass in the region of a major nerve, nerve entering or exiting the mass, fusiform shape, abnormalities of the muscle supplied by the nerve, split-fat sign, target sign and fascicular appearance should always evoke a peripheric nerve sheath neoplasm. Although no single imaging finding or combination of findings allows definitive differentiation between benign from malign peripheric neurogenic tumors, both US and MR imaging may show useful features that can lead us to a correct diagnosis and improve patient treatment. Traumatic neuromas and Morton neuromas are commonly associated to an amputation stump or are located in the intermetatarsal space. Lipomatosis of a nerve usually appears as a nerve enlargement, with thickened nerve fascicles, embedded in evenly distributed fat. Nerve sheath ganglion has a cystic appearance and commonly occurs at the level of the knee. Intraneural perineuroma usually affects young people and manifests as a focal and fusiform nerve enlargement. In this article, we review clinical characteristics and radiologic appearances of these neurogenic lesions, observing pathologic correlation, when possible.

Hearing preservation after low dose linac radiosurgery for acoustic neuroma depends on initial hearing and time

International Nuclear Information System (INIS)

Roos, Daniel E.; Potter, Andrew E.; Zacest, Andrew C.

2011-01-01

Purpose: To assess long term outcomes and factors determining hearing preservation after low dose linac stereotactic radiosurgery (SRS) for acoustic neuroma (AN) at the Royal Adelaide Hospital using prospectively collected data. Material and methods: Between 1994 and 2010, 102 patients had SRS for AN. Five patients had neurofibromatosis type 2, six sporadic cases had relapsed after surgery, and the remaining 91 sporadic cases had primary SRS. Dose was 12 or 14 Gy. Sustained changes ⩾ 2 mm in any diameter were deemed significant, and useful hearing was defined as inter-aural pure tone average (PTA) ⩽ 50 dB. Possible prognostic factors for hearing retention were tested by dividing the patients at pre-specified cutpoints: age (60 years), maximum tumour diameter (20 mm), initial PTA (20 dB) and dose (12 vs 14 Gy). Results: Eighty-four of the 91 sporadic primary SRS cases were evaluable for tumour control with at least one post-treatment MRI. Their median follow-up was 65 mo (range 10–184 mo). Eighty-two (97.6%) were controlled, the remaining two requiring salvage surgery for progression at 5.75 and 9.75 years. Also, one of the post-operative cases required surgery at 2.1 years after SRS. For the 50 sporadic primary SRS patients with initially useful hearing, median age was 56 (range 21–76), median initial PTA 16 dB (range −11 to +45 dB) and median tumour diameter 21 mm (range 10–33 mm). Four received 14 Gy, the rest 12 Gy. After SRS, 19 patients (38%) retained useful hearing. The Kaplan–Meier estimated preservation rate at 5 years was 50% (95% CI 36–64%) but by 10 years, this had fallen to 23% (95% CI 12–41%). On univariate analysis, the only significant factor was initial PTA (P < 0.0001). The estimated risk of hearing loss after SRS for patients with initial PTA ⩾ 20 dB was 5.0 (95% CI 2.2–11.2) times that with PTA < 20 dB. Conclusions: Tumour control was excellent (99/102 = 97% freedom from surgical salvage). Hearing preservation was strongly

Neuromas

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... RAC) Information OIG Opioid and Chronic Pain Management OSHA Off-Label Use Physician Payment Sunshine Act (Open ... a treatment plan that best suits your individual case. Padding and Taping: Special padding at the ball ...

Breaking paradigms in severe epistaxis: the importance of looking for the S-point.

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Kosugi, Eduardo Macoto; Balsalobre, Leonardo; Mangussi-Gomes, João; Tepedino, Miguel Soares; San-da-Silva, Daniel Marcus; Cabernite, Erika Mucciolo; Hermann, Diego; Stamm, Aldo Cassol

Since the introduction of nasal endoscopy into the field of Otorhinolaryngology, the treatment paradigm for cases of severe epistaxis has shifted toward early and precise identification of the bleeding site. Although severe epistaxis is usually considered to arise from posterior bleeding, an arterial vascular pedicle in the superior portion of the nasal septum, around the axilla projection of the middle turbinate, posterior to the septal body, frequently has been observed. That vascular pedicle was named the Stamm's S-point. The aim of this study was to describe the S-point and report cases of severe epistaxis originating from it. A retrospective case series study was conducted. Nine patients with spontaneous severe epistaxis, where the S-point was identified as the source of bleeding, were treated between March 2016 and March 2017. Male predominance (77.8%) with age average of 59.3 years old were reported. Most cases presented comorbidities (88.9%) and were not taking acetylsalicylic acid (66.7%). A predominance of left sided involvement (55.6%) and anteroposterior bleeding being the principal initial presentation (77.8%) was seen. Six patients (66.7%) presented with hemoglobin levels below 10g/dL, and four (44.4%) required blood transfusion. Cauterization of S-point was performed in all patients, with complete resolution of bleeding. No patient experienced recurrence of severe epistaxis. The Stamm's S-point, a novel source of spontaneous severe epistaxis, is reported, and its cauterization was effective and safe. Otolaryngologists must actively seek this site of bleeding in cases of severe epistaxis. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Validation of self-reported start year of mobile phone use in a Swedish case-control study on radiofrequency fields and acoustic neuroma risk.

Science.gov (United States)

Pettersson, David; Bottai, Matteo; Mathiesen, Tiit; Prochazka, Michaela; Feychting, Maria

2015-01-01

The possible effect of radiofrequency exposure from mobile phones on tumor risk has been studied since the late 1990s. Yet, empirical information about recall of the start of mobile phone use among adult cases and controls has never been reported. Limited knowledge about recall errors hampers interpretations of the epidemiological evidence. We used network operator data to validate the self-reported start year of mobile phone use in a case-control study of mobile phone use and acoustic neuroma risk. The answers of 96 (29%) cases and 111 (22%) controls could be included in the validation. The larger proportion of cases reflects a more complete and detailed reporting of subscription history. Misclassification was substantial, with large random errors, small systematic errors, and no significant differences between cases and controls. The average difference between self-reported and operator start year was -0.62 (95% confidence interval: -1.42, 0.17) years for cases and -0.71 (-1.50, 0.07) years for controls, standard deviations were 3.92 and 4.17 years, respectively. Agreement between self-reported and operator-recorded data categorized into short, intermediate and long-term use was moderate (kappa statistic: 0.42). Should an association exist, dilution of risk estimates and distortion of exposure-response patterns for time since first mobile phone use could result from the large random errors in self-reported start year. Retrospective collection of operator data likely leads to a selection of "good reporters", with a higher proportion of cases. Thus, differential recall cannot be entirely excluded.

The prognostic value of histopathology on lingual nerve neurosensory recovery after micro-neurosurgery

DEFF Research Database (Denmark)

Hørberg, Mette; Reibel, Jesper; Kragelund, Camilla

2016-01-01

OBJECTIVE: Micro-neurosurgical repair is considered in permanent nerve damage but the outcome is unpredictable. We examined if histopathologic parameters of traumatic neuromas have a prognostic value for recovery in relation to lingual nerve micro-neurosurgery. MATERIALS AND METHODS: Retrospective...... case study on neurosensory recovery after micro-neurosurgery. Outcome variables were as follows: pain perception, two-point discrimination, and sum score of perception, before and 12 months after micro-neurosurgery. Predictive histopathology variables included size, nerve tissue, and inflammation...

Digital microwave communication engineering point-to-point microwave systems

CERN Document Server

Kizer, George

2013-01-01

The first book to cover all engineering aspects of microwave communication path design for the digital age Fixed point-to-point microwave systems provide moderate-capacity digital transmission between well-defined locations. Most popular in situations where fiber optics or satellite communication is impractical, it is commonly used for cellular or PCS site interconnectivity where digital connectivity is needed but not economically available from other sources, and in private networks where reliability is most important. Until now, no book has adequately treated all en

Acoustic Neuroma

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... below: ? Brain Tumors Brain Disorders AVMs Radiosurgery Gamma Knife Linac Radiotherapy Overview Childhood Brain Tumors Radiation Therapy Radiation Injury Treatment Day Making a Decision Centers of Excellence BRAIN TALK® ...

Morton's Neuroma

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... Search Where do you hurt? Interactive Foot Diagram Softball Injuries to the Foot and Ankle Your feet ... ankles take a beating when you are playing softball. Softball players should be aware of the following ...

Quantitative structure-property relationships for prediction of boiling point, vapor pressure, and melting point.

Science.gov (United States)

Dearden, John C

2003-08-01

Boiling point, vapor pressure, and melting point are important physicochemical properties in the modeling of the distribution and fate of chemicals in the environment. However, such data often are not available, and therefore must be estimated. Over the years, many attempts have been made to calculate boiling points, vapor pressures, and melting points by using quantitative structure-property relationships, and this review examines and discusses the work published in this area, and concentrates particularly on recent studies. A number of software programs are commercially available for the calculation of boiling point, vapor pressure, and melting point, and these have been tested for their predictive ability with a test set of 100 organic chemicals.

Finger image quality based on singular point localization

DEFF Research Database (Denmark)

Wang, Jinghua; Olsen, Martin A.; Busch, Christoph

2014-01-01

Singular points are important global features of fingerprints and singular point localization is a crucial step in biometric recognition. Moreover the presence and position of the core point in a captured fingerprint sample can reflect whether the finger is placed properly on the sensor. Therefore...... and analyze the importance of singular points on biometric accuracy. The experiment is based on large scale databases and conducted by relating the measured quality of a fingerprint sample, given by the positions of core points, to the biometric performance. The experimental results show the positions of core...

Perceived Importance of Various Job Characteristics by West Point Graduates

Science.gov (United States)

McLaughlin, Gerald W.; Butler, Richard P.

1973-01-01

This study investigates the relative importance of various job characteristics to a select group of Army officers. Additionally, the study seeks to see if a need structure posited by Maslow exists among military officers. (Author/RK)

Critical Points in Distance Learning System

Directory of Open Access Journals (Sweden)

Airina Savickaitė

2013-08-01

Full Text Available Purpose – This article presents the results of distance learning system analysis, i.e. the critical elements of the distance learning system. The critical points of distance learning are a part of distance education online environment interactivity/community process model. The most important is the fact that the critical point is associated with distance learning participants. Design/methodology/approach – Comparative review of articles and analysis of distance learning module. Findings – A modern man is a lifelong learner and distance learning is a way to be a modern person. The focus on a learner and feedback is the most important thing of learning distance system. Also, attention should be paid to the lecture-appropriate knowledge and ability to convey information. Distance system adaptation is the way to improve the learner’s learning outcomes. Research limitations/implications – Different learning disciplines and learning methods may have different critical points. Practical implications – The information of analysis could be important for both lecturers and students, who studies distance education systems. There are familiar critical points which may deteriorate the quality of learning. Originality/value – The study sought to develop remote systems for applications in order to improve the quality of knowledge. Keywords: distance learning, process model, critical points. Research type: review of literature and general overview.

Background Document on Starting Points for Sustainable Biomass. Part 1. Risks and chances with regard to the import of biomass in the Netherlands

International Nuclear Information System (INIS)

Richert, W.; Sielhorst, S.

2006-03-01

Social organizations point out the sustainability risks involved in biomass production. Upon urgent request of Dutch environmental organizations a set of sustainability criteria must be developed for imported biomass. Part 1 of this background document intends to sketch the background of the risks that are observed by the environmental organizations. Part 2, which is yet to be published, will look at the risks in the light of opportunities of energy crops for producing countries. [nl

Magnetic resonance imaging of the internal auditory canal

International Nuclear Information System (INIS)

Daniels, D.L.; Herfkins, R.; Koehler, P.R.; Millen, S.J.; Shaffer, K.A.; Williams, A.L.; Haughton, V.M.

1984-01-01

Three patients with exclusively or predominantly intracanalicular neuromas and 5 with presumably normal internal auditory canals were examined with prototype 1.4- or 1.5-tesla magnetic resonance (MR) scanners. MR images showed the 7th and 8th cranial nerves in the internal auditory canal. The intracanalicular neuromas had larger diameter and slightly greater signal strength than the nerves. Early results suggest that minimal enlargement of the nerves can be detected even in the internal auditory canal

Wall shear stress fixed points in blood flow

Science.gov (United States)

Arzani, Amirhossein; Shadden, Shawn

2017-11-01

Patient-specific computational fluid dynamics produces large datasets, and wall shear stress (WSS) is one of the most important parameters due to its close connection with the biological processes at the wall. While some studies have investigated WSS vectorial features, the WSS fixed points have not received much attention. In this talk, we will discuss the importance of WSS fixed points from three viewpoints. First, we will review how WSS fixed points relate to the flow physics away from the wall. Second, we will discuss how certain types of WSS fixed points lead to high biochemical surface concentration in cardiovascular mass transport problems. Finally, we will introduce a new measure to track the exposure of endothelial cells to WSS fixed points.

Point cloud data management (extended abstract)

NARCIS (Netherlands)

Van Oosterom, P.J.M.; Ravada, S.; Horhammer, M.; Martinez Rubi, O.; Ivanova, M.; Kodde, M.; Tijssen, T.P.M.

2014-01-01

Point cloud data are important sources for 3D geo-information. The point cloud data sets are growing in popularity and in size. Modern Big Data acquisition and processing technologies, such as laser scanning from airborne, mobile, or static platforms, dense image matching from photos, multi-beam

Characterizing fixed points

Directory of Open Access Journals (Sweden)

Sanjo Zlobec

2017-04-01

Full Text Available A set of sufficient conditions which guarantee the existence of a point x⋆ such that f(x⋆ = x⋆ is called a "fixed point theorem". Many such theorems are named after well-known mathematicians and economists. Fixed point theorems are among most useful ones in applied mathematics, especially in economics and game theory. Particularly important theorem in these areas is Kakutani's fixed point theorem which ensures existence of fixed point for point-to-set mappings, e.g., [2, 3, 4]. John Nash developed and applied Kakutani's ideas to prove the existence of (what became known as "Nash equilibrium" for finite games with mixed strategies for any number of players. This work earned him a Nobel Prize in Economics that he shared with two mathematicians. Nash's life was dramatized in the movie "Beautiful Mind" in 2001. In this paper, we approach the system f(x = x differently. Instead of studying existence of its solutions our objective is to determine conditions which are both necessary and sufficient that an arbitrary point x⋆ is a fixed point, i.e., that it satisfies f(x⋆ = x⋆. The existence of solutions for continuous function f of the single variable is easy to establish using the Intermediate Value Theorem of Calculus. However, characterizing fixed points x⋆, i.e., providing answers to the question of finding both necessary and sufficient conditions for an arbitrary given x⋆ to satisfy f(x⋆ = x⋆, is not simple even for functions of the single variable. It is possible that constructive answers do not exist. Our objective is to find them. Our work may require some less familiar tools. One of these might be the "quadratic envelope characterization of zero-derivative point" recalled in the next section. The results are taken from the author's current research project "Studying the Essence of Fixed Points". They are believed to be original. The author has received several feedbacks on the preliminary report and on parts of the project

Responsiveness and minimal clinically important change

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Frost, Poul; Falla, Deborah

2015-01-01

Study Design A prospective cohort study nested in a randomized controlled trial. Objectives To determine and compare responsiveness and minimal clinically important change of the modified Constant score (CS) and the Oxford Shoulder Score (OSS). Background The OSS and the CS are commonly used...... to assess shoulder outcomes. However, few studies have evaluated the measurement properties of the OSS and CS in terms of responsiveness and minimal clinically important change. Methods The study included 126 patients who reported having difficulty returning to usual activities 8 to 12 weeks after...... were observed for the CS and the OSS. Minimal clinically important change ROC values were 6 points for the OSS and 11 points for the CS, with upper 95% cutoff limits of 12 and 22 points, respectively. Conclusion The CS and the OSS were both suitable for assessing improvement after decompression surgery....

Detecting corner points from digital curves

International Nuclear Information System (INIS)

Sarfraz, M.

2011-01-01

Corners in digital images give important clues for shape representation, recognition, and analysis. Since dominant information regarding shape is usually available at the corners, they provide important features for various real life applications in the disciplines like computer vision, pattern recognition, computer graphics. Corners are the robust features in the sense that they provide important information regarding objects under translation, rotation and scale change. They are also important from the view point of understanding human perception of objects. They play crucial role in decomposing or describing the digital curves. They are also used in scale space theory, image representation, stereo vision, motion tracking, image matching, building mosaics and font designing systems. If the corner points are identified properly, a shape can be represented in an efficient and compact way with sufficient accuracy. Corner detection schemes, based on their applications, can be broadly divided into two categories: binary (suitable for binary images) and gray level (suitable for gray level images). Corner detection approaches for binary images usually involve segmenting the image into regions and extracting boundaries from those regions that contain them. The techniques for gray level images can be categorized into two classes: (a) Template based and (b) gradient based. The template based techniques utilize correlation between a sub-image and a template of a given angle. A corner point is selected by finding the maximum of the correlation output. Gradient based techniques require computing curvature of an edge that passes through a neighborhood in a gray level image. Many corner detection algorithms have been proposed in the literature which can be broadly divided into two parts. One is to detect corner points from grayscale images and other relates to boundary based corner detection. This contribution mainly deals with techniques adopted for later approach

Dynamic magnetic x-points

International Nuclear Information System (INIS)

Leboeuf, J.N.; Tajima, T.; Dawson, J.M.

1981-03-01

Two-and-one-half dimensional magnetostatic and electromagnetic particle simulations of time-varying magnetic x-points and the associated plasma response are reported. The stability and topology depend on the crossing angle of the field lines at the x-point, irrespective of the plasma β. The electrostatic field and finite Larmor radius effects play an important role in current penetration and shaping of the plasma flow. The snapping of the field lines, and dragging of the plasma into, and confinement of the plasma at, an o-point (magnetic island) is observed. Magnetic island coalescence with explosive growth of the coalescence mode occurs and is accompanied by a large increase of kinetic energy and temperature as well as the formation of hot tails on the distribution functions

Modeling the contribution of point sources and non-point sources to Thachin River water pollution.

Science.gov (United States)

Schaffner, Monika; Bader, Hans-Peter; Scheidegger, Ruth

2009-08-15

Major rivers in developing and emerging countries suffer increasingly of severe degradation of water quality. The current study uses a mathematical Material Flow Analysis (MMFA) as a complementary approach to address the degradation of river water quality due to nutrient pollution in the Thachin River Basin in Central Thailand. This paper gives an overview of the origins and flow paths of the various point- and non-point pollution sources in the Thachin River Basin (in terms of nitrogen and phosphorus) and quantifies their relative importance within the system. The key parameters influencing the main nutrient flows are determined and possible mitigation measures discussed. The results show that aquaculture (as a point source) and rice farming (as a non-point source) are the key nutrient sources in the Thachin River Basin. Other point sources such as pig farms, households and industries, which were previously cited as the most relevant pollution sources in terms of organic pollution, play less significant roles in comparison. This order of importance shifts when considering the model results for the provincial level. Crosschecks with secondary data and field studies confirm the plausibility of our simulations. Specific nutrient loads for the pollution sources are derived; these can be used for a first broad quantification of nutrient pollution in comparable river basins. Based on an identification of the sensitive model parameters, possible mitigation scenarios are determined and their potential to reduce the nutrient load evaluated. A comparison of simulated nutrient loads with measured nutrient concentrations shows that nutrient retention in the river system may be significant. Sedimentation in the slow flowing surface water network as well as nitrogen emission to the air from the warm oxygen deficient waters are certainly partly responsible, but also wetlands along the river banks could play an important role as nutrient sinks.

Procalcitonin as a biomarker for severe Plasmodium falciparum disease: a critical appraisal of a semi-quantitative point-of-care test in a cohort of travellers with imported malaria.

Science.gov (United States)

Hesselink, Dennis A; Burgerhart, Jan-Steven; Bosmans-Timmerarends, Hanna; Petit, Pieter; van Genderen, Perry J J

2009-09-01

Imported malaria occurs as a relatively rare event in developed countries. As a consequence, most clinicians have little experience in making clinical assessments of disease severity and decisions regarding the need for parenteral therapy or high-level monitoring. In this study, the diagnostic accuracy of procalcitonin (PCT) for severe Plasmodium falciparum disease was assessed in a cohort of 100 consecutive travellers with various species of imported malaria. In all patients, PCT was measured on admission with a semi-quantitative 'point-of-care' test. Patients with severe P. falciparum malaria had significantly higher median PCT levels on admission as compared with patients with uncomplicated P. falciparum disease. In addition, PCT levels in patients with non-falciparum malaria were also higher compared with patients with non-severe falciparum malaria but lower compared with severe P. falciparum malaria. At a cut-off point of 10 ng/mL, PCT had a sensitivity of 0,67 and a specificity of 0,94 for severe falciparum disease. However, at lower cut-off points the specificity and positive predictive value were rather poor although the sensitivity and negative predictive value remained high. Potential drawbacks in the interpretation of elevated PCT levels on admission may be caused by infections with non-falciparum species and by concomitant bacterial infections. Semi-quantitative determination of PCT on admission is of limited use in the initial clinical assessment of disease severity in travellers with imported malaria, especially in settings with limited experience with the treatment of malaria.

47 CFR 90.419 - Points of communication.

Science.gov (United States)

2010-10-01

... importance to mobile stations; or (2) Wireline communications facilities between such points are inoperative... transmitted are of immediate importance to mobile stations; or (2) Wireline communications facilities between...

Investigation on the pinch point position in heat exchangers

Science.gov (United States)

Pan, Lisheng; Shi, Weixiu

2016-06-01

The pinch point is important for analyzing heat transfer in thermodynamic cycles. With the aim to reveal the importance of determining the accurate pinch point, the research on the pinch point position is carried out by theoretical method. The results show that the pinch point position depends on the parameters of the heat transfer fluids and the major fluid properties. In most cases, the pinch point locates at the bubble point for the evaporator and the dew point for the condenser. However, the pinch point shifts to the supercooled liquid state in the near critical conditions for the evaporator. Similarly, it shifts to the superheated vapor state with the condensing temperature approaching the critical temperature for the condenser. It even can shift to the working fluid entrance of the evaporator or the supercritical heater when the heat source fluid temperature is very high compared with the absorbing heat temperature. A wrong position for the pinch point may generate serious mistake. In brief, the pinch point should be founded by the iterative method in all conditions rather than taking for granted.

Gas canalography

International Nuclear Information System (INIS)

Portela, L.A.P.

1984-01-01

The advantages and limitations of the cisternography of the cerebello-pontine angle and internal auditory canal, obtained after intrathecal injection of small amount of air (4ml), and the computed tomography, as a simple, sensitive and highly diagnostic procedure, are discussed. The diagnosis of two intracanalicular and cisternal neuromas of less than 10mm in two patients and the safe exclusion of a neuroma in 6 ears of 4 patients are presented. A brief review of the literature is made. (M.A.C.) [pt

Pilot points method for conditioning multiple-point statistical facies simulation on flow data

Science.gov (United States)

Ma, Wei; Jafarpour, Behnam

2018-05-01

We propose a new pilot points method for conditioning discrete multiple-point statistical (MPS) facies simulation on dynamic flow data. While conditioning MPS simulation on static hard data is straightforward, their calibration against nonlinear flow data is nontrivial. The proposed method generates conditional models from a conceptual model of geologic connectivity, known as a training image (TI), by strategically placing and estimating pilot points. To place pilot points, a score map is generated based on three sources of information: (i) the uncertainty in facies distribution, (ii) the model response sensitivity information, and (iii) the observed flow data. Once the pilot points are placed, the facies values at these points are inferred from production data and then are used, along with available hard data at well locations, to simulate a new set of conditional facies realizations. While facies estimation at the pilot points can be performed using different inversion algorithms, in this study the ensemble smoother (ES) is adopted to update permeability maps from production data, which are then used to statistically infer facies types at the pilot point locations. The developed method combines the information in the flow data and the TI by using the former to infer facies values at selected locations away from the wells and the latter to ensure consistent facies structure and connectivity where away from measurement locations. Several numerical experiments are used to evaluate the performance of the developed method and to discuss its important properties.

Diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury

International Nuclear Information System (INIS)

Medina, L.S.; Yaylali, Ilker; Zurakowski, David; Ruiz, Jennifer; Altman, Nolan R.; Grossman, John A.I.

2006-01-01

Detailed evaluation of a brachial plexus birth injury is important for treatment planning. To determine the diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury. Included in the study were 31 children with perinatal brachial plexus injury who underwent surgical intervention. All patients had cervical and brachial plexus MRI. The standard of reference was the combination of intraoperative (1) surgical evaluation and (2) electrophysiological studies (motor evoked potentials, MEP, and somatosensory evoked potentials, SSEP), and (3) the evaluation of histopathological neuronal loss. MRI findings of cord lesion, pseudomeningocele, and post-traumatic neuroma were correlated with the standard of reference. Diagnostic performance characteristics including sensitivity and specificity were determined. From June 2001 to March 2004, 31 children (mean age 7.3 months, standard deviation 1.6 months, range 4.8-12.1 months; 19 male, 12 female) with a brachial plexus birth injury who underwent surgical intervention were enrolled. Sensitivity and specificity of an MRI finding of post-traumatic neuroma were 97% (30/31) and 100% (31/31), respectively, using the contralateral normal brachial plexus as the control. However, MRI could not determine the exact anatomic area (i.e. trunk or division) of the post-traumatic brachial plexus neuroma injury. Sensitivity and specificity for an MRI finding of pseudomeningocele in determining exiting nerve injury were 50% and 100%, respectively, using MEP, and 44% and 80%, respectively, using SSEP as the standard of reference. MRI in infants could not image well the exiting nerve roots to determine consistently the presence or absence of definite avulsion. In children younger than 18 months with brachial plexus injury, the MRI finding of pseudomeningocele has a low sensitivity and a high specificity for nerve root avulsion. MRI and MR myelography cannot image well the exiting nerve roots to determine

Point Topography and Within-Session Learning Are Important Predictors of Pet Dogs’ (Canis lupus familiaris Performance on Human Guided Tasks

Directory of Open Access Journals (Sweden)

Dorey, Nicole R.

2013-07-01

Full Text Available Pet domestic dogs (Canis lupus familiaris are generally considered successful on object choice tasks, reliably following human points to a target. However, defining the specific topography of the point types utilized and assessing the potential for dogs to generalize their responses across similar point types has received little attention. In Experiment 1, we assessed pet dogs’ performance on an object choice task utilizing nine different point types that varied across the dimensions of movement, duration, and distance. These dimensions reliably predicted the performance of pet dogs on this task. In Experiment 2, pet dogs presented with nine different point types in the order of increasing difficulty performed better on more difficult point types than both naive dogs and dogs experiencing the nine points in the order of decreasing difficulty. In Experiment 3, we manipulated the attentional state of the experimenter (as in perspective taking studies and found that human orientation was not a strong predictor of performance on pointing tasks. The results of this study indicate that dogs do not reliably follow all point types without additional training or experience. Furthermore, dogs appear to continuously learn about the dimensions of human points, adjusting their behavior accordingly, even over the course of experimental testing. These findings bring claims of pet dogs’ spontaneous success on pointing tasks into question. The ability to learn about, and respond flexibly to, human gestures may benefit pet dogs living in human homes more than a spontaneous responsiveness to specific gesture types.

Procalcitonin as a biomarker for severe Plasmodium falciparum disease: a critical appraisal of a semi-quantitative point-of-care test in a cohort of travellers with imported malaria

Directory of Open Access Journals (Sweden)

Petit Pieter

2009-09-01

Full Text Available Abstract Background Imported malaria occurs as a relatively rare event in developed countries. As a consequence, most clinicians have little experience in making clinical assessments of disease severity and decisions regarding the need for parenteral therapy or high-level monitoring. In this study, the diagnostic accuracy of procalcitonin (PCT for severe Plasmodium falciparum disease was assessed in a cohort of 100 consecutive travellers with various species of imported malaria. Methods and results In all patients, PCT was measured on admission with a semi-quantitative 'point-of-care' test. Patients with severe P. falciparum malaria had significantly higher median PCT levels on admission as compared with patients with uncomplicated P. falciparum disease. In addition, PCT levels in patients with non-falciparum malaria were also higher compared with patients with non-severe falciparum malaria but lower compared with severe P. falciparum malaria. At a cut-off point of 10 ng/mL, PCT had a sensitivity of 0,67 and a specificity of 0,94 for severe falciparum disease. However, at lower cut-off points the specificity and positive predictive value were rather poor although the sensitivity and negative predictive value remained high. Discussion Potential drawbacks in the interpretation of elevated PCT levels on admission may be caused by infections with non-falciparum species and by concomitant bacterial infections. Conclusion Semi-quantitative determination of PCT on admission is of limited use in the initial clinical assessment of disease severity in travellers with imported malaria, especially in settings with limited experience with the treatment of malaria.

Magnetic resonance imaging of spinal tumors. A study using a 0.3 T vertical magnetic field

International Nuclear Information System (INIS)

Li Ming Hua.

1992-12-01

A total of 168 patients with spinal tumors were evaluated with MRI. The study shows that MRI is a sensitive method for demonstration of spinal tumors. MRI also provides a possibility to separate different histological types of tumors based on their morphology and signal characteristics. Intramedullary tumors (25 cases): Ependymomas (6 cases) and astrocytomas (7 cases) were most common. Ependymomas have a more irregular signal pattern than astrocytomas. Astrocytomas are more common in the upper spine and are more often completely cystic. Contrast enhancement is important for separation of cyst, edema and solid tumor. Intradural extramedullary tumors (31 cases): Neuromas (14 cases) and meningeomas (11 cases) were most common. Neuromas always had markedly increased signal intensity on T2-weighted images. Meningeomas were only hyperintense occasionally. Neuromas were more inhomogeneous than meningeomas on T1-weighted images. Contrast enhancement is valuable for delineation of small tumors. Extradural tumors (91 cases): 76 patients had metastases, 7 primary spinal tumors and 8 multiple myelomas. T1-weighted images are almost always superior to other sequences because tumor invasion in the fatty bone marrow is seen as a low signal area in contrast to the high signal from the fat. Spinal lymphomas (14 cases): May be divided into vertebral, paraspinal and epidural tumors. Most cases have all locations. Spinal neurofibromatosis (7 cases): Most patients had multiple, often bilateral neurofibromas. One patient had a meningeomas on one spinal dysplasia with meningoceles. MRI is superior to other modalities for evaluation of the full extent of the disease. The coronal view is often valuable because of the arrangement of the tumors. In addition to providing diagnosis, MRI is of great value in treatment follow-up

ACS Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2005-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes. The reason for this is that the ACS calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS images of the omega Cen standard field with all nine broadband ACS/WFC filters. This will permit the direct determination of the ACS zero points by comparison with excellent ground-based photometry, and should reduce their uncertainties to less than 0.01 magnitudes. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager. Finally, three of the filters will be repeated from my Cycle 12 observations, allowing for a measurement of any change in sensitivity.

Processing Terrain Point Cloud Data

KAUST Repository

DeVore, Ronald; Petrova, Guergana; Hielsberg, Matthew; Owens, Luke; Clack, Billy; Sood, Alok

2013-01-01

Terrain point cloud data are typically acquired through some form of Light Detection And Ranging sensing. They form a rich resource that is important in a variety of applications including navigation, line of sight, and terrain visualization

Identity Federation and Its Importance for NASA's Future: The SharePoint Extranet Pilot

Science.gov (United States)

Baturin, Rebecca R.

2013-01-01

My project at Kennedy Space Center (KSC) during the spring 2013 Project Management and Systems Engineering Internship was to functionalJy test and deploy the SharePoint Extranet system and ensure successful completion of the project's various lifecycle milestones as described by NASA Procedural Requirement (NPR) 7 120.7. I worked alongside NASA Project Managers, Systems Integration Engineers, and Information Technology (IT) Professionals to pilot this collaboration capability between NASA and its External Partners. The use of identity federation allows NASA to leverage externally-issued credentials of other federal agencies and private aerospace and defense companies, versus the traditional process of granting and maintaining full NASA identities for these individuals. This is the first system of its kind at NASA and it will serve as a pilot for the Federal Government. Recognizing the novelty of this service, NASA's initial approach for deployment included a pilot period where nearby employees of Patrick Air Force Base would assist in testing and deployment. By utilizing a credential registration process, Air Force users mapped their Air Force-issued Common Access Cards (CAC) to a NASA identity for access to the External SharePoint. Once the Air Force stands up an Active Directory Federation Services (ADFS) instance within their Data Center and establishes a direct trust with NASA, true identity federation can be established. The next partner NASA is targeting for collaboration is Lockheed Martin (LMCO), since they collaborate frequently for the ORION Program. Through the use of Exostar as an identity hub, LMCO employees will be able to access NASA data on a need to know basis, with NASA ultimately managing access. In a time when every dollar and resource is being scrutinized, this capability is an exciting new way for NASA to continue its collaboration efforts in a cost and resource effective manner.

["An Italian Court recognizes the occupational origin of a trigeminal neuroma in a mobile telephone user: a case-study of the complex relationships between science and laws"].

Science.gov (United States)

Lagorio, Susanna; Vecchia, P

2011-01-01

Scientific knowledge is essential for the resolution of disputes in law and administrative applications (such as toxic tort litigation and workers' compensation) and provides essential input for public policy decisions. There are no socially agreed-upon rules for the application of this knowledge except in the law. On a practical level, the legal system lacks the ability to assess the validity of scientific knowledge that can be used as evidence and therefore relies heavily on expert opinion. A key issue is how to ensure that professionals in any field provide judges with sound advice, based on relevant and reliable scientific evidence. The search for solutions to this problem seems particularly urgent in Italy, a country where a number of unprecedented verdicts of guilt have been pronounced in trials involving personal injuries from exposure to electromagnetic fields. An Italian Court has recently recognized the occupational origin of a trigeminal neuroma in a mobile telephone user, and ordered the Italian Workers' Compensation Authority (INAIL) to award the applicant compensation for a high degree (80%) of permanent disability. We describe and discuss the salient aspects of this sentence as a case-study in the framework of the use (and misuse) of scientific evidence in toxic-tort litigations. Based on the motivations of the verdict, it appears that the judge relied on seriously flawed expert testimonies. The "experts" who served in this particular trial were clearly inexperienced in forensic epidemiology in general, as well as in the topic at hand. Selective overviews of scientific evidence concerning cancer risks from mobile phone use were provided, along with misleading interpretations of findings from relevant epidemiologic studies (including the dismissal of the Interphone study results on the grounds of purported bias resulting from industry funding). The necessary requirements to proceed to causal inferences at individual level were not taken into account

Critical point analysis of phase envelope diagram

International Nuclear Information System (INIS)

Soetikno, Darmadi; Siagian, Ucok W. R.; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Soewono, Edy; Gunawan, Agus Y.

2014-01-01

Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab

Critical point analysis of phase envelope diagram

Energy Technology Data Exchange (ETDEWEB)

Soetikno, Darmadi; Siagian, Ucok W. R. [Department of Petroleum Engineering, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Kusdiantara, Rudy, E-mail: rkusdiantara@s.itb.ac.id; Puspita, Dila, E-mail: rkusdiantara@s.itb.ac.id; Sidarto, Kuntjoro A., E-mail: rkusdiantara@s.itb.ac.id; Soewono, Edy; Gunawan, Agus Y. [Department of Mathematics, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2014-03-24

Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

Point-of-Purchase Advertising. Learning Activity.

Science.gov (United States)

Shackelford, Ray

1998-01-01

In this technology education activity, students learn the importance of advertising, conduct a day-long survey of advertising strategies, and design and produce a tabletop point-of-purchase advertisement. (JOW)

Optimal External-Memory Planar Point Enclosure

DEFF Research Database (Denmark)

Arge, Lars; Samoladas, Vasilis; Yi, Ke

2007-01-01

.g. spatial and temporal databases, and is dual to the important and well-studied orthogonal range searching problem. Surprisingly, despite the fact that the problem can be solved optimally in internal memory with linear space and O(log N+K) query time, we show that one cannot construct a linear sized......In this paper we study the external memory planar point enclosure problem: Given N axis-parallel rectangles in the plane, construct a data structure on disk (an index) such that all K rectangles containing a query point can be reported I/O-efficiently. This problem has important applications in e...... external memory point enclosure data structure that can be used to answer a query in O(log  B N+K/B) I/Os, where B is the disk block size. To obtain this bound, Ω(N/B 1−ε ) disk blocks are needed for some constant ε>0. With linear space, the best obtainable query bound is O(log 2 N+K/B) if a linear output...

Detecting Change-Point via Saddlepoint Approximations

Institute of Scientific and Technical Information of China (English)

Zhaoyuan LI; Maozai TIAN

2017-01-01

It's well-known that change-point problem is an important part of model statistical analysis.Most of the existing methods are not robust to criteria of the evaluation of change-point problem.In this article,we consider "mean-shift" problem in change-point studies.A quantile test of single quantile is proposed based on saddlepoint approximation method.In order to utilize the information at different quantile of the sequence,we further construct a "composite quantile test" to calculate the probability of every location of the sequence to be a change-point.The location of change-point can be pinpointed rather than estimated within a interval.The proposed tests make no assumptions about the functional forms of the sequence distribution and work sensitively on both large and small size samples,the case of change-point in the tails,and multiple change-points situation.The good performances of the tests are confirmed by simulations and real data analysis.The saddlepoint approximation based distribution of the test statistic that is developed in the paper is of independent interest and appealing.This finding may be of independent interest to the readers in this research area.

The universal cardinal ordering of fixed points

International Nuclear Information System (INIS)

San Martin, Jesus; Moscoso, Ma Jose; Gonzalez Gomez, A.

2009-01-01

We present the theorem which determines, by a permutation, the cardinal ordering of fixed points for any orbit of a period doubling cascade. The inverse permutation generates the orbit and the symbolic sequence of the orbit is obtained as a corollary. Interestingly enough, it is important to point that this theorem needs no previous information about any other orbit; also the cardinal ordering is achieved automatically with no need to compare numerical values associated with every point of the orbit (as would be the case if kneading theory were used).

Interval Mathematics Applied to Critical Point Transitions

Directory of Open Access Journals (Sweden)

Benito A. Stradi

2012-03-01

Full Text Available The determination of critical points of mixtures is important for both practical and theoretical reasons in the modeling of phase behavior, especially at high pressure. The equations that describe the behavior of complex mixtures near critical points are highly nonlinear and with multiplicity of solutions to the critical point equations. Interval arithmetic can be used to reliably locate all the critical points of a given mixture. The method also verifies the nonexistence of a critical point if a mixture of a given composition does not have one. This study uses an interval Newton/Generalized Bisection algorithm that provides a mathematical and computational guarantee that all mixture critical points are located. The technique is illustrated using several example problems. These problems involve cubic equation of state models; however, the technique is general purpose and can be applied in connection with other nonlinear problems.

ACS Photometric Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2003-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes in the Johnson filters. The reason for this is that ACS observations of excellent ground-based standard fields, such as the omega Cen field used for WFPC2 calibrations, have not been obtained. Instead, the ACS photometric calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS broadband images of the omega Cen standard field with both the WFC and HRC. This will permit the direct determination of the ACS transformations, and is expected to double the accuracy to which the ACS zero points are known. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager.

Acceleration of saddle-point searches with machine learning

Energy Technology Data Exchange (ETDEWEB)

Peterson, Andrew A., E-mail: andrew-peterson@brown.edu [School of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

2016-08-21

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Acceleration of saddle-point searches with machine learning

International Nuclear Information System (INIS)

Peterson, Andrew A.

2016-01-01

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Acceleration of saddle-point searches with machine learning.

Science.gov (United States)

Peterson, Andrew A

2016-08-21

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Biosafety: degree of importance in the point of view of undergraduate dental students from Univille

OpenAIRE

Maria Dalva de S. SCHROEDER; Constanza MARIN; Fabio MIRI

2010-01-01

Introduction and objective: This study evaluated the degree ofimportance regarding biosafety in the point of view of undergraduatedental students from the University of the Region of Joinville– Univille. Material and methods: The sample was composed of142 undergraduate dental students from first to fifth year, who wereasked to sign the term of free and clarified assent in order to answera questionnaire with 13 closed-ended and 2 open-ended questionsregarding dental clinical practice and conce...

Tobacco point-of-purchase promotion: examining tobacco industry documents.

Science.gov (United States)

Lavack, Anne M; Toth, Graham

2006-10-01

In the face of increasing media restrictions around the world, point-of-purchase promotion (also called point-of-sale merchandising, and frequently abbreviated as POP or POS) is now one of the most important tools that tobacco companies have for promoting tobacco products. Using tobacco industry documents, this paper demonstrates that tobacco companies have used point-of-purchase promotion in response to real or anticipated advertising restrictions. Their goal was to secure dominance in the retail setting, and this was achieved through well-trained sales representatives who offered contracts for promotional incentive programmes to retailers, which included the use of point-of-sale displays and merchandising fixtures. Audit programmes played an important role in ensuring contract enforcement and compliance with a variety of tobacco company incentive programmes. Tobacco companies celebrated their merchandising successes, in recognition of the stiff competition that existed among tobacco companies for valuable retail display space.

MRI of lesser metatarsophalangeal joint plantar plate tears and associated adjacent interspace lesions

Energy Technology Data Exchange (ETDEWEB)

Umans, Hilary [Albert Einstein College of Medicine and Lenox Hill Radiology Imaging and Associates, Bronx, NY (United States); Srinivasan, Ramya; Elsinger, Elisabeth [Albert Einstein College of Medicine, Bronx, NY (United States); Wilde, Gregory E. [Lenox Hill Radiology Imaging and Associates, Bronx, NY (United States)

2014-10-15

To identify the variety of second and third intermetatarsal space (IS) lesions that may coexist with and without adjacent metatarsophalangeal joint (MTP) plantar plate (PP) tears. One hundred forefoot MRIs in 96 patients with metatarsalgia obtained between 30 September 2011 and 21 July 2012 using 1.5- or 3-T MRI were retrospectively reviewed in consensus by two MSK radiologists and one podiatrist (DPM). MRI was evaluated for second and third MTP PP tear and the presence/nature of second and third IS lesions. Second and third IS neuromas were measured in transverse (trans) dimension. A total of 40 PP tears were identified: 36 at the second and 4 at the third MTP. Second MTP PP tear was identified in 33 % of females and 40.5 % of males. In the 63 female feet there were 21 second MTP PP tears, all of which also had second IS lesions: pericapsular fibrosis (16), bursitis (4), and ganglion (1). In the 37 male feet there were 15 second MTP PP tears, 14 of which had second IS lesions: pericapsular fibrosis (8), bursitis (5), and ganglion (1). There was no definite second IS neuroma adjacent to any second MTP PP tear. In females without PP tear, there were 24 second (3 mm trans average) and 43 third IS neuromas (4.1 mm trans average). In males without PP tear, there were 9 second (3.4 mm trans average) and 16 third IS neuromas (4.1 mm trans average). MTP PP tears occurred in 40 % of our cases, 90 % of which occurred at the second MTP. Almost all coexisted with non-neuromatous second IS lesions. (orig.)

MRI of lesser metatarsophalangeal joint plantar plate tears and associated adjacent interspace lesions

International Nuclear Information System (INIS)

Umans, Hilary; Srinivasan, Ramya; Elsinger, Elisabeth; Wilde, Gregory E.

2014-01-01

To identify the variety of second and third intermetatarsal space (IS) lesions that may coexist with and without adjacent metatarsophalangeal joint (MTP) plantar plate (PP) tears. One hundred forefoot MRIs in 96 patients with metatarsalgia obtained between 30 September 2011 and 21 July 2012 using 1.5- or 3-T MRI were retrospectively reviewed in consensus by two MSK radiologists and one podiatrist (DPM). MRI was evaluated for second and third MTP PP tear and the presence/nature of second and third IS lesions. Second and third IS neuromas were measured in transverse (trans) dimension. A total of 40 PP tears were identified: 36 at the second and 4 at the third MTP. Second MTP PP tear was identified in 33 % of females and 40.5 % of males. In the 63 female feet there were 21 second MTP PP tears, all of which also had second IS lesions: pericapsular fibrosis (16), bursitis (4), and ganglion (1). In the 37 male feet there were 15 second MTP PP tears, 14 of which had second IS lesions: pericapsular fibrosis (8), bursitis (5), and ganglion (1). There was no definite second IS neuroma adjacent to any second MTP PP tear. In females without PP tear, there were 24 second (3 mm trans average) and 43 third IS neuromas (4.1 mm trans average). In males without PP tear, there were 9 second (3.4 mm trans average) and 16 third IS neuromas (4.1 mm trans average). MTP PP tears occurred in 40 % of our cases, 90 % of which occurred at the second MTP. Almost all coexisted with non-neuromatous second IS lesions. (orig.)

Pointing control for LDR

Science.gov (United States)

Yam, Y.; Briggs, C.

1988-01-01

One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

Histologic features of mesotherapy-induced orbital fat inflammation.

Science.gov (United States)

Nabavi, Cameron B; Minckler, Donald S; Tao, Jeremiah P

2009-01-01

A 67-year-old man developed acute orbital inflammation after receiving cosmetic mesotherapy (Lipo-Dissolve) to the inferior orbital fat compartments. The injection was intended to cause lipolysis and shrinkage of fat lobules with subsequent cosmetic improvement. Injections of a mixture of bile salts, phospholipid, and alcohol preservative bilaterally in inferior orbital fat lobules led to an acute inflammatory reaction characterized histologically 12 days later by mild lymphocytic infiltration, fat necrosis, and fibrosis in the target areas. Benign proliferation of peripheral nerve trunks consistent with a traumatic neuroma was also noted histologically on one side. Inflammation including fat necrosis and traumatic neuroma are all possible consequences of mesotherapy.

ANALISA BREAK EVENT POINT (BEP TERHADAP LABA PERUSAHAAN

Directory of Open Access Journals (Sweden)

Muhammad Yusuf

2015-09-01

Full Text Available Break event point or the break-even point can be defined as a situation where the operating company does not make a profit and not a loss. The goal is to provide the knowledge to increase knowledge about the break event point (the point of principal and its relationship with the company profit and to know how the results of the. Analysis break event point is very important for the leadership of the company to determine the production rate how much the cost will be equal to the amount of sales or in other words to determine the break event point we will determine the relationship between sales, production, selling price, cost, loss or profit, making it easier for leaders to take discretion.DOI: 10.15408/ess.v4i1.1955 

Combining different types of scale space interest points using canonical sets

NARCIS (Netherlands)

Kanters, F.M.W.; Denton, T.; Shokoufandeh, A.; Florack, L.M.J.; Haar Romenij, ter B.M.; Sgallari, F.; Murli, A.; Paragios, N.

2007-01-01

Scale space interest points capture important photometric and deep structure information of an image. The information content of such points can be made explicit using image reconstruction. In this paper we will consider the problem of combining multiple types of interest points used for image

A critical analysis of the tender points in fibromyalgia.

Science.gov (United States)

Harden, R Norman; Revivo, Gadi; Song, Sharon; Nampiaparampil, Devi; Golden, Gary; Kirincic, Marie; Houle, Timothy T

2007-03-01

To pilot methodologies designed to critically assess the American College of Rheumatology's (ACR) diagnostic criteria for fibromyalgia. Prospective, psychophysical testing. An urban teaching hospital. Twenty-five patients with fibromyalgia and 31 healthy controls (convenience sample). Pressure pain threshold was determined at the 18 ACR tender points and five sham points using an algometer (dolorimeter). The patients "algometric total scores" (sums of the patients' average pain thresholds at the 18 tender points) were derived, as well as pain thresholds across sham points. The "algometric total score" could differentiate patients with fibromyalgia from normals with an accuracy of 85.7% (P pain across sham points than across ACR tender points, sham points also could be used for diagnosis (85.7%; Ps tested vs other painful conditions. The points specified by the ACR were only modestly superior to sham points in making the diagnosis. Most importantly, this pilot suggests single points, smaller groups of points, or sham points may be as effective in diagnosing fibromyalgia as the use of all 18 points, and suggests methodologies to definitively test that hypothesis.

Point and interval estimation of pollinator importance: a study using pollination data of Silene caroliniana.

Science.gov (United States)

Reynolds, Richard J; Fenster, Charles B

2008-05-01

Pollinator importance, the product of visitation rate and pollinator effectiveness, is a descriptive parameter of the ecology and evolution of plant-pollinator interactions. Naturally, sources of its variation should be investigated, but the SE of pollinator importance has never been properly reported. Here, a Monte Carlo simulation study and a result from mathematical statistics on the variance of the product of two random variables are used to estimate the mean and confidence limits of pollinator importance for three visitor species of the wildflower, Silene caroliniana. Both methods provided similar estimates of mean pollinator importance and its interval if the sample size of the visitation and effectiveness datasets were comparatively large. These approaches allowed us to determine that bumblebee importance was significantly greater than clearwing hawkmoth, which was significantly greater than beefly. The methods could be used to statistically quantify temporal and spatial variation in pollinator importance of particular visitor species. The approaches may be extended for estimating the variance of more than two random variables. However, unless the distribution function of the resulting statistic is known, the simulation approach is preferable for calculating the parameter's confidence limits.

Obstructive acute abdomen: reviewing important points

International Nuclear Information System (INIS)

Francisco, Marina Celli; Abud, Thiago Giansante; Reibscheid, Samuel; Szejnfeld, Jacob; Lederman, Henrique Manoel; Colleone Neto, Ramiro

2008-01-01

The obstructive acute abdomen is a common presentation, for which safe and effective management depends on a fast and accurate diagnosis. Conventional radiograph remains the first choice among the imaging exams because of its availability, low cost and the possibility to be done serially to follow the patient's clinical progression. The ultrasonography does not require ionizing radiation. It is a dynamic and in realtime exam. Computed tomography is used increasingly due to the provision of essential diagnostic information not apparent from radiographs, such as the confirmation of the obstruction, degree and place of the occlusion, presence of ischemia as well as the causes of the obstruction. Magnetic resonance imaging has presented great technological advances and it may play a role in the future of obstructive acute abdomen diagnosis. The objective of this pictorial essay is to review the different imaging techniques used on diagnosing obstructive acute abdomen. (author)

The Antitriangular Factorization of Saddle Point Matrices

KAUST Repository

Pestana, J.

2014-01-01

Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle point matrices and demonstrate how it represents the common nullspace method. We show that rank-1 updates to the saddle point matrix can be easily incorporated into the factorization and give bounds on the eigenvalues of matrices important in saddle point theory. We show the relation of this factorization to constraint preconditioning and how it transforms but preserves the structure of block diagonal and block triangular preconditioners. © 2014 Society for Industrial and Applied Mathematics.

Probing multiband superconductivity by point-contact spectroscopy

International Nuclear Information System (INIS)

Daghero, D; Gonnelli, R S

2010-01-01

Point-contact spectroscopy was originally developed for the determination of the electron-phonon spectral function in normal metals. However, in the past 20 years it has become an important tool in the investigation of superconductors. As a matter of fact, point contacts between a normal metal and a superconductor can provide information on the amplitude and symmetry of the energy gap that, in the superconducting state, opens up at the Fermi level. In this paper we review the experimental and theoretical aspects of point-contact spectroscopy in superconductors, and we give an experimental survey of the most recent applications of this technique to anisotropic and multiband superconductors. (topical review)

Identification of lightning vulnerability points on complex grounded structures

OpenAIRE

Becerra Garcia, Marley; Cooray, Vernon; Hartono, Z.A

2007-01-01

The identification of the most vulnerable points on a given structure to be struck by lightning is an important issue on the design of areliable lightning protection system. Traditionally, these lightning strike points are identified using the rolling sphere method, through anempirical correlation with the prospective peak return stroke current. However, field observations in Kuala Lumpur and Singapore haveshown that the points where lightning flashes strike buildings also depend on the heigh...

Fixed point theory in metric type spaces

CERN Document Server

Agarwal, Ravi P; O’Regan, Donal; Roldán-López-de-Hierro, Antonio Francisco

2015-01-01

Written by a team of leading experts in the field, this volume presents a self-contained account of the theory, techniques and results in metric type spaces (in particular in G-metric spaces); that is, the text approaches this important area of fixed point analysis beginning from the basic ideas of metric space topology. The text is structured so that it leads the reader from preliminaries and historical notes on metric spaces (in particular G-metric spaces) and on mappings, to Banach type contraction theorems in metric type spaces, fixed point theory in partially ordered G-metric spaces, fixed point theory for expansive mappings in metric type spaces, generalizations, present results and techniques in a very general abstract setting and framework. Fixed point theory is one of the major research areas in nonlinear analysis. This is partly due to the fact that in many real world problems fixed point theory is the basic mathematical tool used to establish the existence of solutions to problems which arise natur...

Point-by-point written fiber-Bragg gratings and their application in complex grating designs.

Science.gov (United States)

Marshall, Graham D; Williams, Robert J; Jovanovic, Nemanja; Steel, M J; Withford, Michael J

2010-09-13

The point-by-point technique of fabricating fibre-Bragg gratings using an ultrafast laser enables complete control of the position of each index modification that comprises the grating. By tailoring the local phase, amplitude and spacing of the grating's refractive index modulations it is possible to create gratings with complex transmission and reflection spectra. We report a series of grating structures that were realized by exploiting these flexibilities. Such structures include gratings with controlled bandwidth, and amplitude- and phase-modulated sampled (or superstructured) gratings. A model based on coupled-mode theory provides important insights into the manufacture of such gratings. Our approach offers a quick and easy method of producing complex, non-uniform grating structures in both fibres and other mono-mode waveguiding structures.

What qualities are most important to making a point of care test desirable for clinicians and others offering sexually transmitted infection testing?

Directory of Open Access Journals (Sweden)

Yu-Hsiang Hsieh

2011-04-01

Full Text Available To investigate the possible effects of different levels of attributes of a point-of-care test (POCT on sexually transmitted infection (STI professionals' decisions regarding an ideal POCT for STI(s.An online survey was designed based on a large-scale in-depth focus discussion study among STI experts and professionals. The last section of the survey "build your own POCT" was designed by employing the discrete choice experiment approach. Practicing clinicians from two venues, STI-related international conference attendees and U.S. STD clinic clinicians were invited to participate in the survey. Conditional logistical regression modeling was used for data analysis.Overall, 256 subjects took the online survey with 218 (85% completing it. Most of the participants were STD clinic clinicians who already used some POCTs in their practice. "The time frame required" was identified as a major barrier that currently made it difficult to use STI POCTs. Chlamydia trachomatis was the organism chosen as the top priority for a new POCT, followed by a test that would diagnose early seroconversion for HIV, and a syphilis POCT. Without regard to organism type selected, sensitivity of 90-99% was always the most important attribute to be considered, followed by a cost of $20. However, when the test platform was prioritized for early HIV seroconversion or syphilis, sensitivity was still ranked as most important, but specificity was rated second most important.STI professionals preferred C. trachomatis as the top priority for a new POCT with sensitivity over 90%, low cost, and a very short completion time.

Fort Peck-Wolf Point transmission line project, Montana

International Nuclear Information System (INIS)

1992-01-01

The primary objective of the project is to replace the existing 36-mile Fort Peck-Wolf Point transmission line which has reached the end of its useful service life. Presently, the overall condition of this existing section of the 47-year-old line is poor. Frequent repairs have been required because of the absence of overhead ground wires. The continued maintenance of the line will become more expensive and customer interruptions will persist because of the damage due to lightning. The expense of replacing shell rotted poles, and the concern for the safety of the maintenance personnel because of hazards caused by severe shell rot are also of primary importance. The operational and maintenance problems coupled with power system simulation studies, demonstrate the need for improvements to the Wolf Point area to serve area loads. Western's Wolf Point Substation is an important point of interconnection for the power output from the Fort Peck Dam to area loads as far away as Williston, North Dakota. The proposed transmission line replacement would assure that there will continue to be reliable transmission capacity available to serve area electrical loads, as well as provide a reliable second high-voltage transmission path from the Fort Peck generation to back-up a loss of the Fort Peck-Wolf Point 115-kV Line No. 1

Can fisheries-induced evolution shift reference points for fisheries management?

DEFF Research Database (Denmark)

Heino, Mikko; Baulier, Loїc; Boukal, David S.

2013-01-01

Biological reference points are important tools for fisheries management. Reference points are not static, but may change when a population's environment or the population itself changes. Fisheries-induced evolution is one mechanism that can alter population characteristics, leading to “shifting...

Treatment of Acoustic Neuroma

Science.gov (United States)

... Home Learn Treatment Options Overview English English Arabic Catalan Chinese (Simplified) Chinese (Traditional) Danish French German Greek ... for delivering stereotactic radiation have improved, an increasing number of patients have chosen to receive stereotactic radiosurgery ...

Acoustic Neuroma Educational Video

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Full Text Available ... Meeting Host a Meeting Volunteer Become a Volunteer Opportunities Support Overview Patient Events Fundraising Programs Join Team ... Host a meeting Volunteer Back Volunteering with ANA Opportunities Fundraising Programs Back Join Team ANA Legacy Society ...

Acoustic Neuroma Educational Video

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Full Text Available ... Support Groups Is a support group for me? Find a Group Upcoming Events Video Library Photo Gallery ... Support ANetwork Peer Support Program Community Connections Overview Find a Meeting Host a Meeting Volunteer Become a ...

Acoustic Neuroma Educational Video

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Full Text Available ... Library Photo Gallery One-on-One Support ANetwork Peer Support Program Community Connections Overview Find a Meeting ... Photo Gallery One-on-One Support Back ANetwork Peer Support Program Community Connections Back Overview Find a ...

Acoustic Neuroma Educational Video

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Full Text Available ... Johns Hopkins Patient Event - Vanderbilt Resources Back Patient Resources Request a Patient Kit Healthcare Choosing a Healthcare Provider Related Links Healthcare Provider List Member Portal Webinar ...

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Full Text Available ... Back Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic ... 205-8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home ...

Acoustic Neuroma Educational Video

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Acoustic Neuroma Educational Video

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Full Text Available ... 8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English Arabic Catalan Chinese (Simplified) Chinese ( ...

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Full Text Available ... Research Back Keck Medicine of USC Massachusetts General Hospital University of California, Irvine A.N.S.R.S. Study Yale University Vanderbilt University Mayo Clinic Patient Registry Caregivers Public Webinars Patient Stories Keywords ...

Acoustic Neuroma Educational Video

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Full Text Available ... info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English Arabic Catalan Chinese (Simplified) Chinese ( ...

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Full Text Available ... Opportunities Support Overview Patient Events Fundraising Programs Join Team ANA Legacy Society Ways to Give Help us ... Volunteering with ANA Opportunities Fundraising Programs Back Join Team ANA Legacy Society Ways to give Help us ...

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Visual Communication in PowerPoint Presentations in Applied Linguistics

Science.gov (United States)

Kmalvand, Ayad

2014-01-01

PowerPoint knowledge presentation as a digital genre has established itself as the main software by which the findings of theses are disseminated in the academic settings. Although the importance of PowerPoint presentations is typically realized in academic settings like lectures, conferences, and seminars, the study of the visual features of…

IEEE Standard for Floating Point Numbers

Indian Academy of Sciences (India)

IAS Admin

Floating point numbers are an important data type in compu- tation which is used ... quite large! Integers are ... exp, the value of the exponent will be taken as (exp –127). The ..... bit which is truncated is 1, add 1 to the least significant bit, else.

Blue-noise remeshing with farthest point optimization

KAUST Repository

Yan, Dongming

2014-08-01

In this paper, we present a novel method for surface sampling and remeshing with good blue-noise properties. Our approach is based on the farthest point optimization (FPO), a relaxation technique that generates high quality blue-noise point sets in 2D. We propose two important generalizations of the original FPO framework: adaptive sampling and sampling on surfaces. A simple and efficient algorithm for accelerating the FPO framework is also proposed. Experimental results show that the generalized FPO generates point sets with excellent blue-noise properties for adaptive and surface sampling. Furthermore, we demonstrate that our remeshing quality is superior to the current state-of-the art approaches. © 2014 The Eurographics Association and John Wiley & Sons Ltd.

Blue-noise remeshing with farthest point optimization

KAUST Repository

Yan, Dongming; Guo, Jianwei; Jia, Xiaohong; Zhang, Xiaopeng; Wonka, Peter

2014-01-01

In this paper, we present a novel method for surface sampling and remeshing with good blue-noise properties. Our approach is based on the farthest point optimization (FPO), a relaxation technique that generates high quality blue-noise point sets in 2D. We propose two important generalizations of the original FPO framework: adaptive sampling and sampling on surfaces. A simple and efficient algorithm for accelerating the FPO framework is also proposed. Experimental results show that the generalized FPO generates point sets with excellent blue-noise properties for adaptive and surface sampling. Furthermore, we demonstrate that our remeshing quality is superior to the current state-of-the art approaches. © 2014 The Eurographics Association and John Wiley & Sons Ltd.

Application of the nudged elastic band method to the point-to-point radio wave ray tracing in IRI modeled ionosphere

Science.gov (United States)

Nosikov, I. A.; Klimenko, M. V.; Bessarab, P. F.; Zhbankov, G. A.

2017-07-01

Point-to-point ray tracing is an important problem in many fields of science. While direct variational methods where some trajectory is transformed to an optimal one are routinely used in calculations of pathways of seismic waves, chemical reactions, diffusion processes, etc., this approach is not widely known in ionospheric point-to-point ray tracing. We apply the Nudged Elastic Band (NEB) method to a radio wave propagation problem. In the NEB method, a chain of points which gives a discrete representation of the radio wave ray is adjusted iteratively to an optimal configuration satisfying the Fermat's principle, while the endpoints of the trajectory are kept fixed according to the boundary conditions. Transverse displacements define the radio ray trajectory, while springs between the points control their distribution along the ray. The method is applied to a study of point-to-point ionospheric ray tracing, where the propagation medium is obtained with the International Reference Ionosphere model taking into account traveling ionospheric disturbances. A 2-dimensional representation of the optical path functional is developed and used to gain insight into the fundamental difference between high and low rays. We conclude that high and low rays are minima and saddle points of the optical path functional, respectively.

Enhanced finite difference scheme for the neutron diffusion equation using the importance function

International Nuclear Information System (INIS)

Vagheian, Mehran; Vosoughi, Naser; Gharib, Morteza

2016-01-01

Highlights: • An enhanced finite difference scheme for the neutron diffusion equation is proposed. • A seven-step algorithm is considered based on the importance function. • Mesh points are distributed through entire reactor core with respect to the importance function. • The results all proved that the proposed algorithm is highly efficient. - Abstract: Mesh point positions in Finite Difference Method (FDM) of discretization for the neutron diffusion equation can remarkably affect the averaged neutron fluxes as well as the effective multiplication factor. In this study, by aid of improving the mesh point positions, an enhanced finite difference scheme for the neutron diffusion equation is proposed based on the neutron importance function. In order to determine the neutron importance function, the adjoint (backward) neutron diffusion calculations are performed in the same procedure as for the forward calculations. Considering the neutron importance function, the mesh points can be improved through the entire reactor core. Accordingly, in regions with greater neutron importance, density of mesh elements is higher than that in regions with less importance. The forward calculations are then performed for both of the uniform and improved non-uniform mesh point distributions and the results (the neutron fluxes along with the corresponding eigenvalues) for the two cases are compared with each other. The results are benchmarked against the reference values (with fine meshes) for Kang and Rod Bundle BWR benchmark problems. These benchmark cases revealed that the improved non-uniform mesh point distribution is highly efficient.

Roentgenographic features of neurofibromatosis von Recklinghausen

Energy Technology Data Exchange (ETDEWEB)

Galanski, M.; Vogelsang, H.; Cramer, B.M.; Thun, F.; Peters, P.E.

1983-10-01

The basic abnormality of neurofibromatosis consists not only of a maldevelopment of the neuroectoderm but also of the mesoderm. Therefore any organ or system of the body may be involved. Following a short clinical review of the central (acoustic) and peripheral type the well known and the more unusual radiographic findings are summarized. They include cranial and intracranial manifestations (orbitosphenoid dysplasia, bone defects of the skull, acoustic neuroma, glioma of the optic nerve and chiasm, meningioma), spinal lesions (scoliosis, vetebral scalloping, meningocele, neuroma, ependymoma), skeletal abnormalities (pseudarthrosis), cardiovascular manifestations, pulmonary fibrosis, tumors of the gastrointestinal and urinary tract and different endocrinopathies. Some of the roentgeologic symptoms are very characteristic and allow definitive diagnosis.

Importance of Grammar in English Teaching

Institute of Scientific and Technical Information of China (English)

赵天毓

2011-01-01

Grammar teaching is one of the most difficult and important points in the middle school. However, there exist some problems with present grammar teaching, such as students＇ poor knowledge of grammar, improper teaching methods and the ignorance of grammar

Molecular genetic approach to human meningioma: loss of genes on chromosome 22

International Nuclear Information System (INIS)

Seizinger, B.R.; De La Monte, S.; Atkins, L.; Gusella, J.F.; Martuza, R.L.

1987-01-01

A molecular genetic approach employing polymorphic DNA markers has been used to investigate the role of chromosomal aberrations in meningioma, one of the most common tumors of the human nervous system. Comparison of the alleles detected by DNA markers in tumor DNA versus DNA from normal tissue revealed chromosomal alterations present in primary surgical specimens. In agreement with cytogenetic studies of cultured meningiomas, the most frequent alteration detected was loss of heterozygosity on chromosome 22. Forty of 51 patients were constitutionally heterozygous for at least one chromosome 22 DNA marker. Seventeen of the 40 constitutionally heterozygotic patients (43%) displayed hemizygosity for the corresponding marker in their meningioma tumor tissues. Loss of heterozygosity was also detected at a significantly lower frequency for markers on several other autosomes. In view of the striking association between acoustic neuroma and meningioma in bilateral acoustic neurofibromatosis and the discovery that acoustic neuromas display specific loss of genes on chromosome 22, the authors propose that a common mechanism involving chromosome 22 is operative in the development of both tumor types. Fine-structure mapping to reveal partial deletions in meningiomas may provide the means to clone and characterize a gene (or genes) of importance for tumorigenesis in this and possibly other clinically associated tumors of the human nervous system

Wrox SharePoint 2010 SharePoint911 three-pack

CERN Document Server

Klindt, Todd; Mason, Jennifer; Rogers, Laura; Drisgill, Randy; Ross, John; Riemann, Larry; Perran, Amanda; Perran, Shane; Sanford, Jacob J; Stubbs, Paul; Caravajal, Steve

2012-01-01

The Wrox SharePoint 2010 SharePoint911 Three-Pack combines the contents of three full e-books written by the experts from SharePoint911.  That's over 1800 pages of hands-on advice from Todd Klindt, Shane Young, Laura Rogers, Randy Drisgill, Jennifer Mason, John Ross, and Larry Riemann, among others. In Beginning SharePoint 2010: Building Business Solutions with SharePoint (ISBN 978-0-470-61789-2) by Amanda Perran, Shane Perran, Jennifer Mason, and Laura Rogers, readers learn the core concepts, terminology, and features of SharePoint 2010. In Professiona

Rainfall Deduction Method for Estimating Non-Point Source Pollution Load for Watershed

OpenAIRE

Cai, Ming; Li, Huai-en; KAWAKAMI, Yoji

2004-01-01

The water pollution can be divided into point source pollution (PSP) and non-point source pollution (NSP). Since the point source pollution has been controlled, the non-point source pollution is becoming the main pollution source. The prediction of NSP load is being increasingly important in water pollution controlling and planning in watershed. Considering the monitoring data shortage of NPS in China, a practical estimation method of non-point source pollution load --- rainfall deduction met...

Introducing Nine-Point Circle to Junior High School Students

Science.gov (United States)

Fiangga, S.; Azizah, M. A. N.; Rini, R. N. K.; Hidayanti, A. N.

2018-01-01

The concept of circles is an ancient concept that has appeared since Ancient Egypt from which this concept gives many significant contributions in mathematics’ development until now. Nevertheless, the concept of circles hides many uncover mysterious features that are of applications in mathematics. One of the mysterious features is the Nine-Point Circle. This Nine-point circle is also known as Euler’s circle, six-point circle, Feuerbach’s circle, the twelve-point circle, and many others. Because of these different names, there have been misunderstand among mathematicians about the Nine-Point Circle’s history. Besides, the discussion of Nine-Point Circle can be used to be an initial material to explain elementary geometry topic in junior high school’s level curriculum of 2013. Therefore, this concept needs to be delivered to the students as a geometry introduction. A possible form of the integration historical aspect of Nine-point circle is suggested in this paper as well as its importance in the curriculum of 2013.

Zero-point vibrational effects on optical rotation

DEFF Research Database (Denmark)

Ruud, K.; Taylor, P.R.; Åstrand, P.-O.

2001-01-01

We investigate the effects of molecular vibrations on the optical rotation in two chiral molecules, methyloxirane and trans-2,3-dimethylthiirane. It is shown that the magnitude of zero-point vibrational corrections increases as the electronic contribution to the optical rotation increases....... Vibrational effects thus appear to be important for an overall estimate of the molecular optical rotation, amounting to about 20-30% of the electronic counterpart. We also investigate the special case of chirality introduced in a molecule through isotopic substitution. In this case, the zero-point vibrational...

Flash-Point prediction for binary partially miscible aqueous-organic mixtures

OpenAIRE

Liaw, Horng-Jang; Chen, Chien Tsun; Gerbaud, Vincent

2008-01-01

Flash point is the most important variable used to characterize fire and explosion hazard of liquids. Herein, partially miscible mixtures are presented within the context of liquid-liquid extraction processes and heterogeneous distillation processes. This paper describes development of a model for predicting the flash point of binary partially miscible mixtures of aqueous-organic system. To confirm the predictive efficiency of the derived flash points, the model was verified by comparing the ...

[Definition of ashi point from the view of linguistics].

Science.gov (United States)

Jiang, Shan; Zhao, Jingsheng

2017-01-12

The definition of ashi point has not been unified yet till now. Likewise, the precise explanation on its connotation has always been an elusive question in acupuncture theory. By collecting diverse definitions on ashi point in the textbooks of Acupuncture and Moxibustion , dictionaries and term standards, several rational elements in definitions with consensus were screened. With the assistance of two important theories of cognitive linguistics, such as figure-ground theory and distance iconicity theory, the concept of ashi point was newly defined. Additiona-lly, on the base of the understanding on several similar terms such as "taking the painful site as acupoint", "responding point" and "reactive point", the semanteme analytic method was used to distinguish the difference among them so that the more profound explorations on acupuncture therapy are expounded.

Ecological association between HIV and concurrency point ...

African Journals Online (AJOL)

Ecological association between HIV and concurrency point-prevalence in South Africa's ethnic groups. Chris Kenyon. Abstract. HIV prevalence between different ethnic groups within South Africa exhibits considerable variation. Numerous authors believe that elevated sexual partner concurrency rates are important in the ...

Beginning SharePoint 2010 Administration Windows SharePoint Foundation 2010 and Microsoft SharePoint Server 2010

CERN Document Server

Husman, Göran

2010-01-01

Complete coverage on the latest advances in SharePoint 2010 administration. SharePoint 2010 comprises an abundance of new features, and this book shows you how to take advantage of all SharePoint 2010's many improvements. Written by a four-time SharePoint MVP, Beginning SharePoint 2010 Administration begins with a comparison of SharePoint 2010 compared to the previous version and then examines the differences between WSS 4.0 and MSS 2010. Packed with step-by-step instructions, tips and tricks, and real-world examples, this book dives into the basics of how to install, manage, and administrate

End points and assessments in esthetic dental treatment.

Science.gov (United States)

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

2015-10-01

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

Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

Science.gov (United States)

Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

2018-01-01

Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

How Loud Is Too Loud?

Science.gov (United States)

... Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

May 2002 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains lidar point data from a strip of Southern California coastline (including water, beach, cliffs, and top of cliffs) from Dana Point to Point La...

September 2002 Lidar Point Data of Southern California Coastline: Dana Point to Point La Jolla

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains lidar point data from a strip of Southern California coastline (including water, beach, cliffs, and top of cliffs) from Dana Point to Point La...

A heuristic-based approach for reliability importance assessment of energy producers

International Nuclear Information System (INIS)

Akhavein, A.; Fotuhi Firuzabad, M.

2011-01-01

Reliability of energy supply is one of the most important issues of service quality. On one hand, customers usually have different expectations for service reliability and price. On the other hand, providing different level of reliability at load points is a challenge for system operators. In order to take reasonable decisions and obviate reliability implementation difficulties, market players need to know impacts of their assets on system and load-point reliabilities. One tool to specify reliability impacts of assets is the criticality or reliability importance measure by which system components can be ranked based on their effect on reliability. Conventional methods for determination of reliability importance are essentially on the basis of risk sensitivity analysis and hence, impose prohibitive calculation burden in large power systems. An approach is proposed in this paper to determine reliability importance of energy producers from perspective of consumers or distribution companies in a composite generation and transmission system. In the presented method, while avoiding immense computational burden, the energy producers are ranked based on their rating, unavailability and impact on power flows in the lines connecting to the considered load points. Study results on the IEEE reliability test system show successful application of the proposed method. - Research highlights: → Required reliability level at load points is a concern in modern power systems. → It is important to assess reliability importance of energy producers or generators. → Generators can be ranked based on their impacts on power flow to a selected area. → Ranking of generators is an efficient tool to assess their reliability importance.

How age affects pointing with mouse and touchpad

DEFF Research Database (Denmark)

Hertzum, Morten; Hornbæk, Kasper

2010-01-01

pointing with mouse and touchpad. The goal is to provide an integrated analysis of (a) how these three age groups differ in pointing performance, (b) how these differences are affected by the two pointing devices, and (c) how the submovement structure of cursor trajectories may explain performance...... neither more nor less errors than young and adult participants. All three age groups were slower and made more errors with the touchpad than the mouse, but the touchpad slowed down elderly participants more than young participants, who in turn were slowed down more than adult participants. Adult......Effects of age on pointing performance have become increasingly important as computers have become extensively used by still larger parts of the population. This study empirically investigates young (12-14 years), adult (25-33 years), and elderly (61-69 years) participants' performance when...

Branes, superpotentials and superconformal fixed points

International Nuclear Information System (INIS)

Aharony, O.

1997-01-01

We analyze various brane configurations corresponding to field theories in three, four and five dimensions. We find brane configurations which correspond to three-dimensional N=2 and four-dimensional N=1 supersymmetric QCD theories with quartic superpotentials, in which what appear to be ''hidden parameters'' play an important role. We discuss the construction of five-dimensional N=1 supersymmetric gauge theories and superconformal fixed points using branes, which leads to new five-dimensional N=1 superconformal field theories. The same five-dimensional theories are also used, in a surprising way, to describe new superconformal fixed points of three-dimensional N=2 supersymmetric theories, which have both ''electric'' and ''magnetic'' Coulomb branches. (orig.)

Brain tumor - primary - adults

Science.gov (United States)

... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

Pressure Points in Reading Comprehension: A Quantile Multiple Regression Analysis

Science.gov (United States)

Logan, Jessica

2017-01-01

The goal of this study was to examine how selected pressure points or areas of vulnerability are related to individual differences in reading comprehension and whether the importance of these pressure points varies as a function of the level of children's reading comprehension. A sample of 245 third-grade children were given an assessment battery…

From Point Clouds to Definitions of Architectural Space

DEFF Research Database (Denmark)

Tamke, Martin; Blümel, Ina; Ochmann, Sebastian

2014-01-01

Regarding interior building topology as an important aspect in building design and management, several approaches to indoor point cloud structuring have been introduced recently. Apart from a high-level semantic segmentation of the formerly unstructured point clouds into stories and rooms...... possible applications of these approaches in architectural design and building management and comment on the possible benefits for the building profession. While contemporary practice of spatial arrangement is predominantly based on the manual iteration of spatial topologies, we show that the segmentation...

Point cloud processing for smart systems

Directory of Open Access Journals (Sweden)

Jaromír Landa

2013-01-01

Full Text Available High population as well as the economical tension emphasises the necessity of effective city management – from land use planning to urban green maintenance. The management effectiveness is based on precise knowledge of the city environment. Point clouds generated by mobile and terrestrial laser scanners provide precise data about objects in the scanner vicinity. From these data pieces the state of the roads, buildings, trees and other objects important for this decision-making process can be obtained. Generally, they can support the idea of “smart” or at least “smarter” cities.Unfortunately the point clouds do not provide this type of information automatically. It has to be extracted. This extraction is done by expert personnel or by object recognition software. As the point clouds can represent large areas (streets or even cities, usage of expert personnel to identify the required objects can be very time-consuming, therefore cost ineffective. Object recognition software allows us to detect and identify required objects semi-automatically or automatically.The first part of the article reviews and analyses the state of current art point cloud object recognition techniques. The following part presents common formats used for point cloud storage and frequently used software tools for point cloud processing. Further, a method for extraction of geospatial information about detected objects is proposed. Therefore, the method can be used not only to recognize the existence and shape of certain objects, but also to retrieve their geospatial properties. These objects can be later directly used in various GIS systems for further analyses.

What's the point? Golden and Labrador retrievers living in kennels do not understand human pointing gestures.

Science.gov (United States)

D'Aniello, Biagio; Alterisio, Alessandra; Scandurra, Anna; Petremolo, Emanuele; Iommelli, Maria Rosaria; Aria, Massimo

2017-07-01

In many studies that have investigated whether dogs' capacities to understand human pointing gestures are aspects of evolutionary or developmental social competences, family-owned dogs have been compared to shelter dogs. However, for most of these studies, the origins of shelter dogs were unknown. Some shelter dogs may have lived with families before entering shelters, and from these past experiences, they may have learned to understand human gestures. Furthermore, there is substantial variation in the methodology and analytic approaches used in such studies (e.g. different pointing protocols, different treatment of trials with no-choice response and indoor vs. outdoor experimental arenas). Such differences in methodologies and analysis techniques used make it difficult to compare results obtained from different studies and may account for the divergent results obtained. We thus attempted to control for several parameters by carrying out a test on dynamic proximal and distal pointing. We studied eleven kennel dogs of known origin that were born and raised in a kennels with limited human interaction. This group was compared to a group of eleven dogs comparable in terms of breed, sex and age that had lived with human families since they were puppies. Our results demonstrate that pet dogs outperform kennel dogs in their comprehension of proximal and distal pointing, regardless of whether trials where no-choice was made were considered as errors or were excluded from statistical analysis, meaning that dogs living in kennels do not understand pointing gestures. Even if genetic effects of the domestication process on human-dog relationships cannot be considered as negligible, our data suggest that dogs need to learn human pointing gestures and thus underscore the importance of ontogenetic processes.

Robust tie points selection for InSAR image coregistration

Science.gov (United States)

Skanderi, Takieddine; Chabira, Boulerbah; Afifa, Belkacem; Belhadj Aissa, Aichouche

2013-10-01

Image coregistration is an important step in SAR interferometry which is a well known method for DEM generation and surface displacement monitoring. A practical and widely used automatic coregistration algorithm is based on selecting a number of tie points in the master image and looking for the correspondence of each point in the slave image using correlation technique. The characteristics of these points, their number and their distribution have a great impact on the reliability of the estimated transformation. In this work, we present a method for automatic selection of suitable tie points that are well distributed over the common area without decreasing the desired tie points' number. First we select candidate points using Harris operator. Then from these points we select tie points depending on their cornerness measure (the highest first). Once a tie point is selected, its correspondence is searched for in the slave image, if the similarity measure maximum is less than a given threshold or it is at the border of the search window, this point is discarded and we proceed to the next Harris point, else, the cornerness of the remaining candidates Harris points are multiplied by a spatially radially increasing function centered at the selected point to disadvantage the points in a neighborhood of a radius determined from the size of the common area and the desired number of points. This is repeated until the desired number of points is selected. Results of an ERS1/2 tandem pair are presented and discussed.

Gd-DTPA-enhanced MR imaging in facial nerve paralysis

International Nuclear Information System (INIS)

Tien, R.D.; Dillon, W.P.

1989-01-01

GD-DTPA-enhanced MR imaging was used to evaluate 11 patients with facial nerve paralysis (five acute idiopathic facial palsy (Bell palsy), three chronic recurrent facial palsy, one acute facial palsy after local radiation therapy, one chronic facial dyskinesia, and one facial neuroma). In eight of 11 patients, there was marked enhancement of the infratemporal facial nerve from the labyrinthine segment to the stylomastoid foramen. Two patients had additional contrast enhancement in the internal auditory canal segment. In one patient, enhancement persisted (but to a lesser degree) 8 weeks after symptoms had resolved. In one patient, no enhancement was seen 15 months after resolution of Bell palsy. The facial neuroma was seen as a focal nodular enhancement in the mastoid segment of the facial nerve

Impact Points and Their Effect on Trajectory in Soccer

Directory of Open Access Journals (Sweden)

Kaoru Kimachi

2018-02-01

Full Text Available The kick skill and its analysis are important in Soccer. To detect impact point by using virtual impact model is aim of this study. The virtual impact model was made as a surface composed of virtual markers. As the result, mean coordinate values of impact point were below; straight (Lateral: −24.0 ± 5.6 mm, Horizontal: 152.7 ± 8.4 mm, Vertical: 52.3 ± 4.0 mm, curve (Lateral: −35.6 ± 4.8 mm, Horizontal: 151.6 ± 13.7 mm, Vertical: 47.5 ± 5.2 mm, knuckle (Lateral: −33.3 ± 9.0 mm, Horizontal: 140.8 ± 10.7 mm, Vertical: 52.1 ± 2.7 mm. According to comparison of coordinate value of each trial, mean point of straight was near the center line of foot on instep, mean point of curve was located on inside of foot, mean point of knuckle was near the foot joint. We revealed difference of impact point and showed trajectory of impact point.

Address Points - COUNTY_ADDRESS_POINTS_IDHS_IN: Address Points Maintained by County Agencies in Indiana (Indiana Department of Homeland Security, Point feature class)

Data.gov (United States)

NSGIC State | GIS Inventory — COUNTY_ADDRESS_POINTS_IDHS_IN is an ESRI Geodatabase point feature class that contains address points maintained by county agencies in Indiana, provided by personnel...

Beginning SharePoint 2010 Building Business Solutions with SharePoint

CERN Document Server

Perran, Amanda; Mason, Jennifer; Rogers, Laura

2010-01-01

Two SharePoint MVPs provide the ultimate introduction to SharePoint 2010Beginning SharePoint 2010: Building Team Solutions with SharePoint provides information workers and site managers with extensive knowledge and expert advice, empowering them to become SharePoint champions within their organizations.Provides expansive coverage of SharePoint topics, as well as specialty areas such as forms, excel services, records management, and web content managementDetails realistic usage scenarios, and includes practice examples that highlight best practices for configuration and customizationIncludes de

The Closest Point Method and Multigrid Solvers for Elliptic Equations on Surfaces

KAUST Repository

Chen, Yujia; Macdonald, Colin B.

2015-01-01

© 2015 Society for Industrial and Applied Mathematics. Elliptic partial differential equations are important from both application and analysis points of view. In this paper we apply the closest point method to solve elliptic equations on general

The Tipping Point and the Adventure Advantage.

Science.gov (United States)

Prouty, Dick

1998-01-01

Insights from chaos theory--the interconnectedness of everything, nonlinear cause and effect, leverage and the "tipping point," and the importance of aligning interventions within a system--are applied to social action and illustrated via the role of adventure education in school and community interventions in the Brattleboro (Vermont) Leadership…

Fast Change Point Detection for Electricity Market Analysis

Energy Technology Data Exchange (ETDEWEB)

Berkeley, UC; Gu, William; Choi, Jaesik; Gu, Ming; Simon, Horst; Wu, Kesheng

2013-08-25

Electricity is a vital part of our daily life; therefore it is important to avoid irregularities such as the California Electricity Crisis of 2000 and 2001. In this work, we seek to predict anomalies using advanced machine learning algorithms. These algorithms are effective, but computationally expensive, especially if we plan to apply them on hourly electricity market data covering a number of years. To address this challenge, we significantly accelerate the computation of the Gaussian Process (GP) for time series data. In the context of a Change Point Detection (CPD) algorithm, we reduce its computational complexity from O($n^{5}$) to O($n^{2}$). Our efficient algorithm makes it possible to compute the Change Points using the hourly price data from the California Electricity Crisis. By comparing the detected Change Points with known events, we show that the Change Point Detection algorithm is indeed effective in detecting signals preceding major events.

How Loud Is Too Loud?

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Full Text Available ... Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

Referential Zero Point

Directory of Open Access Journals (Sweden)

Matjaž Potrč

2016-04-01

Full Text Available Perhaps the most important controversy in which ordinary language philosophy was involved is that of definite descriptions, presenting referential act as a community-involving communication-intention endeavor, thereby opposing the direct acquaintance-based and logical proper names inspired reference aimed at securing truth conditions of referential expression. The problem of reference is that of obtaining access to the matters in the world. This access may be forthcoming through the senses, or through descriptions. A review of how the problem of reference is handled shows though that one main practice is to indulge in relations of acquaintance supporting logical proper names, demonstratives, indexicals and causal or historical chains. This testifies that the problem of reference involves the zero point, and with it phenomenology of intentionality. Communication-intention is but one dimension of rich phenomenology that constitutes an agent’s experiential space, his experiential world. Zero point is another constitutive aspect of phenomenology involved in the referential relation. Realizing that the problem of reference is phenomenology based opens a new perspective upon the contribution of analytical philosophy in this area, reconciling it with continental approach, and demonstrating variations of the impossibility related to the real. Chromatic illumination from the cognitive background empowers the referential act, in the best tradition of ordinary language philosophy.

Tipping Point

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Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

Fixed point iterations for quasi-contractive maps in uniformly smooth Banach spaces

International Nuclear Information System (INIS)

Chidume, C.E.; Osilike, M.O.

1992-05-01

Two well-known fixed point iteration methods are applied to approximate fixed points of quasi-contractive maps in real uniformly smooth Banach spaces. While our theorems generalize important known results, our method is of independent interest. (author). 25 refs

The role of fasciae in Civinini–Morton's syndrome

Science.gov (United States)

Stecco, Carla; Fantoni, Ilaria; Macchi, Veronica; Del Borrello, Mario; Porzionato, Andrea; Biz, Carlo; De Caro, Raffaele

2015-01-01

This study evaluates the pathogenetic role of the perineural connective tissue and foot fasciae in Civinini–Morton's neuroma. Eleven feet (seven male, four female; mean age: 70.9 years) were dissected to analyse the anatomy of inter-metatarsal space, particularly the dorsal and plantar fasciae and metatarsal transverse ligament (DMTL). The macrosections were prepared for microscopic analysis. Ten Civinini–Morton neuromas obtained from surgery were also analysed. Magnetic resonance images (MRIs) from 40 patients and 29 controls were compared. Dissections showed that the width of the inter-metatarsal space is established by two fibrous structures: the dorsal foot fascia and the DMTL, which, together, connect the metatarsal bones and resist their splaying. Interosseous muscles spread out into the dorsal fascia of the foot, defining its basal tension. The common digital plantar nerve (CDPN) is encased in concentric layers of fibrous and loose connective tissue, continuous with the vascular sheath and deep foot fascia. Outside this sheath, fibroelastic septa, from DMTL to plantar fascia, and little fat lobules are present, further protecting the nerve against compressive stress. The MRI study revealed high inter-individual variability in the forefoot structures, although only the thickness of the dorsal fascia represented a statistically significant difference between cases and controls. It was hypothesized that alterations in foot support and altered biomechanics act on the interosseous muscles, increasing the stiffness of the dorsal fascia, particularly at the points where these muscles are inserted. Chronic rigidity of this fascia increases the stiffness of the inter-metatarsal space, leading to entrapment of the CDPN. PMID:26467241

Computing three-point functions for short operators

International Nuclear Information System (INIS)

Bargheer, Till; Institute for Advanced Study, Princeton, NJ; Minahan, Joseph A.; Pereira, Raul

2013-11-01

We compute the three-point structure constants for short primary operators of N=4 super Yang.Mills theory to leading order in 1/√(λ) by mapping the problem to a flat-space string theory calculation. We check the validity of our procedure by comparing to known results for three chiral primaries. We then compute the three-point functions for any combination of chiral and non-chiral primaries, with the non-chiral primaries all dual to string states at the first massive level. Along the way we find many cancellations that leave us with simple expressions, suggesting that integrability is playing an important role.

Computing three-point functions for short operators

Energy Technology Data Exchange (ETDEWEB)

Bargheer, Till [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Institute for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Minahan, Joseph A.; Pereira, Raul [Uppsala Univ. (Sweden). Dept. of Physics and Astronomy

2013-11-15

We compute the three-point structure constants for short primary operators of N=4 super Yang.Mills theory to leading order in 1/√(λ) by mapping the problem to a flat-space string theory calculation. We check the validity of our procedure by comparing to known results for three chiral primaries. We then compute the three-point functions for any combination of chiral and non-chiral primaries, with the non-chiral primaries all dual to string states at the first massive level. Along the way we find many cancellations that leave us with simple expressions, suggesting that integrability is playing an important role.

Exploring the reference point in prospect theory: gambles for length of life.

Science.gov (United States)

van Osch, Sylvie M C; van den Hout, Wilbert B; Stiggelbout, Anne M

2006-01-01

Attitude toward risk is an important factor determining patient preferences. Risk behavior has been shown to be strongly dependent on the perception of the outcome as either a gain or a loss. According to prospect theory, the reference point determines how an outcome is perceived. However, no theory on the location of the reference point exists, and for the health domain, there is no direct evidence for the location of the reference point. This article combines qualitative with quantitative data to provide evidence of the reference point in life-year certainty equivalent (CE) gambles and to explore the psychology behind the reference point. The authors argue that goals (aspirations) in life influence the reference point. While thinking aloud, 45 healthy respondents gave certainty equivalents for life-year CE gambles with long and short durations of survival. Contrary to suggestions from the literature, qualitative data argued that the offered certainty equivalent most frequently served as the reference point. Thus, respondents perceived life-year CE gambles as mixed. Framing of the question and goals set in life appeared to be important factors behind the psychology of the reference point. On the basis of the authors' quantitative and qualitative data, they argue that goals alter the perception of outcomes as described by prospect theory by influencing the reference point. This relationship is more apparent for the near future as opposed to the remote future, as goals are mostly set for the near future.

Zero Point of Historical Time

Directory of Open Access Journals (Sweden)

R.S. Khakimov

2014-02-01

Full Text Available Historical studies are based on the assumption that there is a reference-starting point of the space-time – the Zero point of coordinate system. Due to the bifurcation in the Zero Point, the course of social processes changes sharply and the probabilistic causality replaces the deterministic one. For this reason, changes occur in the structure of social relations and statehood form as well as in the course of the ethnic processes. In such a way emerges a new discourse of the national behavior. With regard to the history of the Tatars and Tatarstan, such bifurcation points occurred in the periods of the formation: 1 of the Turkic Khaganate, which began to exist from the 6th century onward and became a qualitatively new State system that reformatted old elements in the new matrix introducing a new discourse of behavior; 2 of the Volga-Kama Bulgaria, where the rivers (Kama, Volga, Vyatka became the most important trade routes determining the singularity of this State. Here the nomadic culture was connected with the settled one and Islam became the official religion in 922; 3 and of the Golden Hordе, a powerful State with a remarkable system of communication, migration of huge human resources for thousands of kilometers, and extensive trade, that caused severe “mutations” in the ethnic terms and a huge mixing of ethnic groups. Given the dwelling space of Tatar population and its evolution within Russia, it can be argued that the Zero point of Tatar history, which conveyed the cultural invariants until today, begins in the Golden Horde. Neither in the Turkic khaganate nor in the Bulgar State, but namely in the Golden Horde. Despite the radical changes, the Russian Empire failed to transform the Tatars in the Russians. Therefore, contemporary Tatars preserved the Golden Horde tradition as a cultural invariant.

Thermal conductivity at a disordered quantum critical point

International Nuclear Information System (INIS)

Hartnoll, Sean A.; Ramirez, David M.; Santos, Jorge E.

2016-01-01

Strongly disordered and strongly interacting quantum critical points are difficult to access with conventional field theoretic methods. They are, however, both experimentally important and theoretically interesting. In particular, they are expected to realize universal incoherent transport. Such disordered quantum critical theories have recently been constructed holographically by deforming a CFT by marginally relevant disorder. In this paper we find additional disordered fixed points via relevant disordered deformations of a holographic CFT. Using recently developed methods in holographic transport, we characterize the thermal conductivity in both sets of theories in 1+1 dimensions. The thermal conductivity is found to tend to a constant at low temperatures in one class of fixed points, and to scale as T"0"."3 in the other. Furthermore, in all cases the thermal conductivity exhibits discrete scale invariance, with logarithmic in temperature oscillations superimposed on the low temperature scaling behavior. At no point do we use the replica trick.

Importance theory for lumped-parameter systems

International Nuclear Information System (INIS)

Cady, K.B.; Kenton, M.A.; Ward, J.C.; Piepho, M.G.

1981-01-01

A general sensitivity theory has been developed for nonlinear lumped parameter system simulations. The point of departure is general perturbation theory for nonlinear systems. Importance theory as developed here allows the calculation of the sensitivity of a response function to any physical or design parameter; importance of any equation or term or physical effect in the system model on the response function; variance of the response function caused by the variances and covariances of all physical parameters; and approximate effect on the response function of missing physical phenomena or incorrect parameters

Point-to-point people with purpose—Exploring the possibility of a commercial traveler market for point-to-point suborbital space transportation

Science.gov (United States)

Webber, Derek

2013-12-01

An argument was made at the First Arcachon Conference on Private Human Access to Space in 2008 [1] that some systematic market research should be conducted into potential market segments for point-to-point suborbital space transportation (PtP), in order to understand whether a commercial market exists which might augment possible government use for such a vehicle. The cargo market potential was subsequently addressed via desk research, and the results, which resulted in a pessimistic business case outlook, were presented in [2]. The same desk research approach is now used in this paper to address the potential business and wealthy individual passenger traveler market segment ("point-to-point people with purpose"). The results, with the assumed ticket pricing, are not encouraging.

Roadmap for import of sustainable biomass. Elaboration of transition path 2. Realisation of the Biomass Import Chain

International Nuclear Information System (INIS)

Faaij, A.

2006-12-01

The main objective of the activities described in this document is to formulate a transition path for realizing sustainable biomass import chains. The following elements are crucial in this process: definition of required activities (research, demonstration, technology development), as well as a description of main uncertainties and barriers; setting up a time path and assessing costs (government investments and market investments); and engaging the main actors in the Netherlands, making an inventory of the current positions and motivation to contribute to the realization of sustainable biomass import chains. This document sketches a road map for the development of sustainable biomass import capacity in time, especially from a national point of view. [mk] [nl

Hardware-accelerated Point Generation and Rendering of Point-based Impostors

DEFF Research Database (Denmark)

Bærentzen, Jakob Andreas

2005-01-01

This paper presents a novel scheme for generating points from triangle models. The method is fast and lends itself well to implementation using graphics hardware. The triangle to point conversion is done by rendering the models, and the rendering may be performed procedurally or by a black box API....... I describe the technique in detail and discuss how the generated point sets can easily be used as impostors for the original triangle models used to create the points. Since the points reside solely in GPU memory, these impostors are fairly efficient. Source code is available online....

Turning points in the history of mathematics

CERN Document Server

Grant, Hardy

2015-01-01

This book explores some of the major turning points in the history of mathematics, ranging from ancient Greece to the present, demonstrating the drama that has often been a part of its evolution. Studying these breakthroughs, transitions, and revolutions, their stumbling-blocks and their triumphs, can help illuminate the importance of the history of mathematics for its teaching, learning, and appreciation. Some of the turning points considered are the rise of the axiomatic method (most famously in Euclid), and the subsequent major changes in it (for example, by David Hilbert); the “wedding,” via analytic geometry, of algebra and geometry; the “taming” of the infinitely small and the infinitely large; the passages from algebra to algebras, from geometry to geometries, and from arithmetic to arithmetics; and the revolutions in the late nineteenth and early twentieth centuries that resulted from Georg Cantor’s creation of transfinite set theory. The origin of each turning point is discussed, along with...

Direct costs of microsurgical management of radiosurgically amenable intracranial pathology in Germany: an analysis of meningiomas, acoustic neuromas, metastases and arteriovenous malformations of less than 3 cm in diameter

International Nuclear Information System (INIS)

Wellis, G.; Nagel, R.; Vollmar, C.; Steiger, H.-J.

2003-01-01

The purpose of the analysis was to appreciate and compare the effective direct costs of microsurgical treatment of intracranial pathology potentially amenable to radiosurgery as they arose in 1998-99. Treatment costs of 127 microsurgically treated patients harboring an arteriovenous malformation (AVM), acoustic neuroma, meningioma or brain metastasis potentially amenable to radiosurgery were reviewed. Costs for the surgical procedure, ICU rare, medical and nursing care on the ward, interclinical bills (ICB) for services provided by other departments and the overhead for basic hotel service were added. For comparison gamma knife costs were calculated by dividing the global operating cost of the gamma knife centre by the number of patients treated in 1999. Average hospitalization time for the entire microsurgical patients was 15.4 + 8.6 days. The patients spent an average of 1.2 ± 2.8 days on ICU. Average operating time for all patients, including preparation, was 393 ± 118 minutes. Average costs for the microsurgical therapy were Eur 10814 ± 6108. These consisted of Eur 1417 ± 426 for the surgical procedure, Eur 1188 ± 2658 for ICU care, Eur 2333 ± 1582 for medical and nursing care on the ward, Eur 1671 ± 1433 for interclinical bills and Eur 4204 ± 2338 for basic hotel service (overhead, Eur 273 per day). 70 % of the microsurgically treated patients needed ancillary inpatient rehabilitation or radiotherapy resulting in an average additional cost for all patients of Eur 2744. Furthermore 20 % of the microsurgically treated patients required an unplanned readmission after discharge, resulting in an average additional costs for all patients of Eur 1684. Average overall costs per patient including ancillary therapy and unplanned read-missions amounted to Eur 15242. For comparison, gamma knife treatment costs per patient amounted to Eur 7920 in 1999. The current analysis showed that for established radiosurgical indications the primary costs of microsurgery

Secure firmware updates for point of sale terminals

CSIR Research Space (South Africa)

Tsague, HD

2015-03-01

Full Text Available of the equipment. In particular, there is an important cost related to the deployment of new software upgrades for the point of sale terminals, since in most cases human intervention is required. In this paper, we present a lightweight protocol for secure firmware...

Point of View: The Importance of Teaching Neuroscience Research at Historically Black Colleges and Universities

Science.gov (United States)

Cohen, Jeremy

2016-01-01

This column shares reflections or thoughtful opinions on issues of broad interest to the community. This month's issue discusses the importance of the insights that are gained through neuroscience research.

Effect Through Broadcasting System Access Point For Video Transmission

Directory of Open Access Journals (Sweden)

Leni Marlina

2015-08-01

Full Text Available Most universities are already implementing wired and wireless network that is used to access integrated information systems and the Internet. At present it is important to do research on the influence of the broadcasting system through the access point for video transmitter learning in the university area. At every university computer network through the access point must also use the cable in its implementation. These networks require cables that will connect and transmit data from one computer to another computer. While wireless networks of computers connected through radio waves. This research will be a test or assessment of how the influence of the network using the WLAN access point for video broadcasting means learning from the server to the client. Instructional video broadcasting from the server to the client via the access point will be used for video broadcasting means of learning. This study aims to understand how to build a wireless network by using an access point. It also builds a computer server as instructional videos supporting software that can be used for video server that will be emitted by broadcasting via the access point and establish a system of transmitting video from the server to the client via the access point.

How Loud Is Too Loud?

Medline Plus

Full Text Available ... to the Brain Video Ménière's Disease Noise-Induced Hearing Loss Otosclerosis Pendred Syndrome Retinitis Pigmentosa - National Eye Institute Sudden Deafness Tinnitus Usher Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who ...

Jump point detection for real estate investment success

Science.gov (United States)

Hui, Eddie C. M.; Yu, Carisa K. W.; Ip, Wai-Cheung

2010-03-01

In the literature, studies on real estate market were mainly concentrating on the relation between property price and some key factors. The trend of the real estate market is a major concern. It is believed that changes in trend are signified by some jump points in the property price series. Identifying such jump points reveals important findings that enable policy-makers to look forward. However, not all jump points are observable from the plot of the series. This paper looks into the trend and introduces a new approach to the framework for real estate investment success. The main purpose of this paper is to detect jump points in the time series of some housing price indices and stock price index in Hong Kong by applying the wavelet analysis. The detected jump points reflect to some significant political issues and economic collapse. Moreover, the relations among properties of different classes and between stocks and properties are examined. It can be shown from the empirical result that a lead-lag effect happened between the prices of large-size property and those of small/medium-size property. However, there is no apparent relation or consistent lead in terms of change point measure between property price and stock price. This may be due to the fact that globalization effect has more impact on the stock price than the property price.

Visibility Analysis in a Point Cloud Based on the Medial Axis Transform

NARCIS (Netherlands)

Peters, R.; Ledoux, H.; Biljecki, F.

2015-01-01

Visibility analysis is an important application of 3D GIS data. Current approaches require 3D city models that are often derived from detailed aerial point clouds. We present an approach to visibility analysis that does not require a city model but works directly on the point cloud. Our approach is

Lost and found: The missing diabolical points in the Fe$_8$ molecular magnet

OpenAIRE

Li, Feifei; Garg, Anupam

2010-01-01

Certain diabolical points in the tunneling spectrum of the single-molecule magnet Fe$_8$ were previously believed to be have been eliminated as a result of a weak fourth-order anisotropy. As shown by Bruno, this is not so, and the points are only displaced in the magnetic field space along the medium anisotropy direction. The previously missing points are numerically located by following the lines of the Berry curvature. The importance of an experimental search for these rediscovered points i...

How Loud Is Too Loud?

Medline Plus

Full Text Available ... Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Who Can I Turn to for Help with My Hearing ... Free Publications Glossary Have a question? Information specialists can answer your questions in English or Spanish. Voice: ( ...

Transient Point Infiltration In The Unsaturated Zone

Science.gov (United States)

Buecker-Gittel, M.; Mohrlok, U.

The risk assessment of leaking sewer pipes gets more and more important due to urban groundwater management and environmental as well as health safety. This requires the quantification and balancing of transport and transformation processes based on the water flow in the unsaturated zone. The water flow from a single sewer leakage could be described as a point infiltration with time varying hydraulic conditions externally and internally. External variations are caused by the discharge in the sewer pipe as well as the state of the leakage itself. Internal variations are the results of microbiological clogging effects associated with the transformation processes. Technical as well as small scale laboratory experiments were conducted in order to investigate the water transport from an transient point infiltration. From the technical scale experiment there was evidence that the water flow takes place under transient conditions when sewage infiltrates into an unsaturated soil. Whereas the small scale experiments investigated the hydraulics of the water transport and the associated so- lute and particle transport in unsaturated soils in detail. The small scale experiment was a two-dimensional representation of such a point infiltration source where the distributed water transport could be measured by several tensiometers in the soil as well as by a selective measurement of the discharge at the bottom of the experimental setup. Several series of experiments were conducted varying the boundary and initial con- ditions in order to derive the important parameters controlling the infiltration of pure water from the point source. The results showed that there is a significant difference between the infiltration rate in the point source and the discharge rate at the bottom, that could be explained by storage processes due to an outflow resistance at the bottom. This effect is overlayn by a decreasing water content decreases over time correlated with a decreasing infiltration

Legibility Evaluation Using Point-of-regard Measurement

Science.gov (United States)

Saito, Daisuke; Saito, Keiichi; Saito, Masao

Web site visibility has become important because of the rapid dissemination of World Wide Web, and combinations of foreground and background colors are crucial in providing high visibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restriction. In this paper, legibility of sentences on web sites was examined using a psychophisiological method, point-of-regard measurement, to obtain other practical data. Ten people with normal color sensations ranging from ages 21 to 29 were recruited. The number of characters per line in each page was arranged in the same number, and the four representative achromatic web-safe colors, that is, #000000, #666666, #999999 and #CCCCCC, were examined. The reading time per character and the gaze time per line were obtained from point-of-regard measurement, and the normalized with the reading time and the gaze time of the three colors were calculated and compared. As the results, it was shown that the time of reading and gaze become long at the same ratio when the contrast decreases by point-of-regard measurement. Therefore, it was indicated that the legibility of color combinations could be estimated by point-of-regard measurement.

Interactive Trunk Extraction from Forest Point Cloud

Directory of Open Access Journals (Sweden)

T. Mizoguchi

2014-06-01

Full Text Available For forest management or monitoring, it is required to constantly measure several parameters of each tree, such as height, diameter at breast height, and trunk volume. Terrestrial laser scanner has been used for this purpose instead of human workers to reduce time and cost for the measurement. In order to use point cloud captured by terrestrial laser scanner in the above applications, it is an important step to extract all trees or their trunks separately. For this purpose, we propose an interactive system in which a user can intuitively and efficiently extract each trunk by a simple editing on the distance image created from the point cloud. We demonstrate the effectiveness of our proposed system from various experiments.

Bird surveys at Stokes Point and Philips Bay, Yukon in 1983. No. 40

Energy Technology Data Exchange (ETDEWEB)

Dickson, D L; Dickson, H L; Aiudi, G M

1988-01-01

The distribution, abundance, and habitat preferences of birds were studied at Stokes Point, Phillips Bay and King Point in the northern Yukon in 1983. These data were gathered to assist in decisions about future development of a port to support marine drilling activities in the Beaufort Sea. Nesting bird densities at Stokes Point were similar to those found elsewhere on the Yukon Coastal Plain due to the similarity in habitat. The lagoon at Stokes Point was locally important to molting ducks. Several species occurred in higher densities at Phillips Bay than elsewhere on the Plain, mainly due to the deltas and spits created by rivers flowing into the Bay. These deltas were locally important to such species as molting non-breeding tundra swans, Canada geese, and ducks. During ground surveys in June, habitat was classified into 13 types and the nesting density for each bird species calculated for each habitat type. Overall bird densities were more than 3 times higher in lowland than in upland habitats. Passerine densities and species were highest in the tall shrub type of habitat found primarily in stream and river valleys. The Yukon Coastal Plain is an important nesting area for the stilt sandpiper, which has a limited breeding range. The Plain is also nationally important for nesting long-billed dowitchers and yellow wagtails, both fairly common in the study area but with very limited breeding distribution within Canada. The Plain is also internationally important to fall staging snow geese. 38 refs., 17 figs., 35 tabs.

Automated Identification of Fiducial Points on 3D Torso Images

Directory of Open Access Journals (Sweden)

Manas M. Kawale

2013-01-01

Full Text Available Breast reconstruction is an important part of the breast cancer treatment process for many women. Recently, 2D and 3D images have been used by plastic surgeons for evaluating surgical outcomes. Distances between different fiducial points are frequently used as quantitative measures for characterizing breast morphology. Fiducial points can be directly marked on subjects for direct anthropometry, or can be manually marked on images. This paper introduces novel algorithms to automate the identification of fiducial points in 3D images. Automating the process will make measurements of breast morphology more reliable, reducing the inter- and intra-observer bias. Algorithms to identify three fiducial points, the nipples, sternal notch, and umbilicus, are described. The algorithms used for localization of these fiducial points are formulated using a combination of surface curvature and 2D color information. Comparison of the 3D coordinates of automatically detected fiducial points and those identified manually, and geodesic distances between the fiducial points are used to validate algorithm performance. The algorithms reliably identified the location of all three of the fiducial points. We dedicate this article to our late colleague and friend, Dr. Elisabeth K. Beahm. Elisabeth was both a talented plastic surgeon and physician-scientist; we deeply miss her insight and her fellowship.

Iterative closest normal point for 3D face recognition.

Science.gov (United States)

Mohammadzade, Hoda; Hatzinakos, Dimitrios

2013-02-01

The common approach for 3D face recognition is to register a probe face to each of the gallery faces and then calculate the sum of the distances between their points. This approach is computationally expensive and sensitive to facial expression variation. In this paper, we introduce the iterative closest normal point method for finding the corresponding points between a generic reference face and every input face. The proposed correspondence finding method samples a set of points for each face, denoted as the closest normal points. These points are effectively aligned across all faces, enabling effective application of discriminant analysis methods for 3D face recognition. As a result, the expression variation problem is addressed by minimizing the within-class variability of the face samples while maximizing the between-class variability. As an important conclusion, we show that the surface normal vectors of the face at the sampled points contain more discriminatory information than the coordinates of the points. We have performed comprehensive experiments on the Face Recognition Grand Challenge database, which is presently the largest available 3D face database. We have achieved verification rates of 99.6 and 99.2 percent at a false acceptance rate of 0.1 percent for the all versus all and ROC III experiments, respectively, which, to the best of our knowledge, have seven and four times less error rates, respectively, compared to the best existing methods on this database.

Controllable resonant tunnelling through single-point potentials: A point triode

International Nuclear Information System (INIS)

Zolotaryuk, A.V.; Zolotaryuk, Yaroslav

2015-01-01

A zero-thickness limit of three-layer heterostructures under two bias voltages applied externally, where one of which is supposed to be a gate parameter, is studied. As a result, an effect of controllable resonant tunnelling of electrons through single-point potentials is shown to exist. Therefore the limiting structure may be termed a “point triode” and considered in the theory of point interactions as a new object. The simple limiting analytical expressions adequately describe the resonant behaviour in the transistor with realistic parameter values and thus one can conclude that the zero-range limit of multi-layer structures may be used in fabricating nanodevices. The difference between the resonant tunnelling across single-point potentials and the Fabry–Pérot interference effect is also emphasized. - Highlights: • The zero-thickness limit of three-layer heterostructures is described in terms of point interactions. • The effect of resonant tunnelling through these single-point potentials is established. • The resonant tunnelling is shown to be controlled by a gate voltage

Radio contamination control on imported food. The bilberry case

International Nuclear Information System (INIS)

Zappa, S.; Calabrese, M.; Stancher, B.

2001-01-01

In this paper was pointed out the European regulation concerning the permissible limits of 137 Cs contamination in food importation, from countries affected by the consequences of the Chernobyl accident of 1986. A discussion about the control systems is lead and original data concerning the importation of the fruits of bilberry, a species particularly sensitive to radio contamination, are reported [it

Registration of Laser Scanning Point Clouds: A Review

Science.gov (United States)

Cheng, Liang; Chen, Song; Xu, Hao; Wu, Yang; Li, Manchun

2018-01-01

The integration of multi-platform, multi-angle, and multi-temporal LiDAR data has become important for geospatial data applications. This paper presents a comprehensive review of LiDAR data registration in the fields of photogrammetry and remote sensing. At present, a coarse-to-fine registration strategy is commonly used for LiDAR point clouds registration. The coarse registration method is first used to achieve a good initial position, based on which registration is then refined utilizing the fine registration method. According to the coarse-to-fine framework, this paper reviews current registration methods and their methodologies, and identifies important differences between them. The lack of standard data and unified evaluation systems is identified as a factor limiting objective comparison of different methods. The paper also describes the most commonly-used point cloud registration error analysis methods. Finally, avenues for future work on LiDAR data registration in terms of applications, data, and technology are discussed. In particular, there is a need to address registration of multi-angle and multi-scale data from various newly available types of LiDAR hardware, which will play an important role in diverse applications such as forest resource surveys, urban energy use, cultural heritage protection, and unmanned vehicles.

Tipping Point

Medline Plus

Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

Fixed Point Learning Based Intelligent Traffic Control System

Science.gov (United States)

Zongyao, Wang; Cong, Sui; Cheng, Shao

2017-10-01

Fixed point learning has become an important tool to analyse large scale distributed system such as urban traffic network. This paper presents a fixed point learning based intelligence traffic network control system. The system applies convergence property of fixed point theorem to optimize the traffic flow density. The intelligence traffic control system achieves maximum road resources usage by averaging traffic flow density among the traffic network. The intelligence traffic network control system is built based on decentralized structure and intelligence cooperation. No central control is needed to manage the system. The proposed system is simple, effective and feasible for practical use. The performance of the system is tested via theoretical proof and simulations. The results demonstrate that the system can effectively solve the traffic congestion problem and increase the vehicles average speed. It also proves that the system is flexible, reliable and feasible for practical use.

Bubble and Dew Point Calculations in Multicomponent and Multireactive Mixtures

OpenAIRE

Bonilla-Petriciolet, A.; Acosta-Martínez, A.; Bravo-Sánchez, U. I.; Segovia-Hernández, J. G.

2006-01-01

Bubble and dew point calculations are useful in chemical engineering and play an important role in the study of separation equipments for non-reactive and reactive mixtures. To the best of the authors’s knowledge, few methods have been proposed for these calculations in systems with several chemical reactions. The objective of this paper is to introduce new conditions for performing bubble and dew point calculations in reactive mixtures. We have developed these conditions based on the a...

Interesting Interest Points

DEFF Research Database (Denmark)

Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

2012-01-01

on spatial invariance of interest points under changing acquisition parameters by measuring the spatial recall rate. The scope of this paper is to investigate the performance of a number of existing well-established interest point detection methods. Automatic performance evaluation of interest points is hard......Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

An adaptive Monte Carlo method under emission point as sampling station for deep penetration calculation

International Nuclear Information System (INIS)

Wang, Ruihong; Yang, Shulin; Pei, Lucheng

2011-01-01

Deep penetration problem has been one of the difficult problems in shielding calculation with Monte Carlo method for several decades. In this paper, an adaptive technique under the emission point as a sampling station is presented. The main advantage is to choose the most suitable sampling number from the emission point station to get the minimum value of the total cost in the process of the random walk. Further, the related importance sampling method is also derived. The main principle is to define the importance function of the response due to the particle state and ensure the sampling number of the emission particle is proportional to the importance function. The numerical results show that the adaptive method under the emission point as a station could overcome the difficulty of underestimation to the result in some degree, and the related importance sampling method gets satisfied results as well. (author)

A point-based rendering approach for real-time interaction on mobile devices

Institute of Scientific and Technical Information of China (English)

LIANG XiaoHui; ZHAO QinPing; HE ZhiYing; XIE Ke; LIU YuBo

2009-01-01

Mobile device is an Important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient.

First impressions and beyond: marketing your practice in touch points--Part II.

Science.gov (United States)

Bisera, Cheryl

2012-01-01

When calling in a marketing expert to boost a practice's numbers, administrators and providers are usually looking for external marketing strategies--ways to attract new patients to the practice. However, one of the most important, yet often overlooked, elements to successfully marketing a practice is the very important work of retaining current patients and turning them into enthusiastic referrers. When new patients are simply filling the place of previous patients that have moved on, you are not building solid practice growth. You can create an atmosphere of loyal referring patients by providing positive touch points that fulfill the needs of your patients. This article will cover touch points that occur before a patient has chosen your practice. Laying the groundwork for positive touch points will give your marketing efforts a snowball effect, build growth, and deliver the most bang for your marketing bucks.

Parametric change point estimation, testing and confidence interval ...

African Journals Online (AJOL)

In many applications like finance, industry and medicine, it is important to consider that the model parameters may undergo changes at unknown moment in time. This paper deals with estimation, testing and confidence interval of a change point for a univariate variable which is assumed to be normally distributed. To detect ...

Processing Terrain Point Cloud Data

KAUST Repository

DeVore, Ronald

2013-01-10

Terrain point cloud data are typically acquired through some form of Light Detection And Ranging sensing. They form a rich resource that is important in a variety of applications including navigation, line of sight, and terrain visualization. Processing terrain data has not received the attention of other forms of surface reconstruction or of image processing. The goal of terrain data processing is to convert the point cloud into a succinct representation system that is amenable to the various application demands. The present paper presents a platform for terrain processing built on the following principles: (i) measuring distortion in the Hausdorff metric, which we argue is a good match for the application demands, (ii) a multiscale representation based on tree approximation using local polynomial fitting. The basic elements held in the nodes of the tree can be efficiently encoded, transmitted, visualized, and utilized for the various target applications. Several challenges emerge because of the variable resolution of the data, missing data, occlusions, and noise. Techniques for identifying and handling these challenges are developed. © 2013 Society for Industrial and Applied Mathematics.

Holographic two-point functions for 4d log-gravity

NARCIS (Netherlands)

Johansson, Niklas; Naseh, Ali; Zojer, Thomas

We compute holographic one- and two-point functions of critical higher-curvature gravity in four dimensions. The two most important operators are the stress tensor and its logarithmic partner, sourced by ordinary massless and by logarithmic non-normalisable gravitons, respectively. In addition, the

Pointing Device Performance in Steering Tasks.

Science.gov (United States)

Senanayake, Ransalu; Goonetilleke, Ravindra S

2016-06-01

Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. © The Author(s) 2016.

Zero-point oscillations, zero-point fluctuations, and fluctuations of zero-point oscillations

International Nuclear Information System (INIS)

Khalili, Farit Ya

2003-01-01

Several physical effects and methodological issues relating to the ground state of an oscillator are considered. Even in the simplest case of an ideal lossless harmonic oscillator, its ground state exhibits properties that are unusual from the classical point of view. In particular, the mean value of the product of two non-negative observables, kinetic and potential energies, is negative in the ground state. It is shown that semiclassical and rigorous quantum approaches yield substantially different results for the ground state energy fluctuations of an oscillator with finite losses. The dependence of zero-point fluctuations on the boundary conditions is considered. Using this dependence, it is possible to transmit information without emitting electromagnetic quanta. Fluctuations of electromagnetic pressure of zero-point oscillations are analyzed, and the corresponding mechanical friction is considered. This friction can be viewed as the most fundamental mechanism limiting the quality factor of mechanical oscillators. Observation of these effects exceeds the possibilities of contemporary experimental physics but almost undoubtedly will be possible in the near future. (methodological notes)

Point-point and point-line moving-window correlation spectroscopy and its applications

Science.gov (United States)

Zhou, Qun; Sun, Suqin; Zhan, Daqi; Yu, Zhiwu

2008-07-01

In this paper, we present a new extension of generalized two-dimensional (2D) correlation spectroscopy. Two new algorithms, namely point-point (P-P) correlation and point-line (P-L) correlation, have been introduced to do the moving-window 2D correlation (MW2D) analysis. The new method has been applied to a spectral model consisting of two different processes. The results indicate that P-P correlation spectroscopy can unveil the details and re-constitute the entire process, whilst the P-L can provide general feature of the concerned processes. Phase transition behavior of dimyristoylphosphotidylethanolamine (DMPE) has been studied using MW2D correlation spectroscopy. The newly proposed method verifies that the phase transition temperature is 56 °C, same as the result got from a differential scanning calorimeter. To illustrate the new method further, a lysine and lactose mixture has been studied under thermo perturbation. Using the P-P MW2D, the Maillard reaction of the mixture was clearly monitored, which has been very difficult using conventional display of FTIR spectra.

Tipping Point

Medline Plus

Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

Multi-Class Simultaneous Adaptive Segmentation and Quality Control of Point Cloud Data

Directory of Open Access Journals (Sweden)

Ayman Habib

2016-01-01

Full Text Available 3D modeling of a given site is an important activity for a wide range of applications including urban planning, as-built mapping of industrial sites, heritage documentation, military simulation, and outdoor/indoor analysis of airflow. Point clouds, which could be either derived from passive or active imaging systems, are an important source for 3D modeling. Such point clouds need to undergo a sequence of data processing steps to derive the necessary information for the 3D modeling process. Segmentation is usually the first step in the data processing chain. This paper presents a region-growing multi-class simultaneous segmentation procedure, where planar, pole-like, and rough regions are identified while considering the internal characteristics (i.e., local point density/spacing and noise level of the point cloud in question. The segmentation starts with point cloud organization into a kd-tree data structure and characterization process to estimate the local point density/spacing. Then, proceeding from randomly-distributed seed points, a set of seed regions is derived through distance-based region growing, which is followed by modeling of such seed regions into planar and pole-like features. Starting from optimally-selected seed regions, planar and pole-like features are then segmented. The paper also introduces a list of hypothesized artifacts/problems that might take place during the region-growing process. Finally, a quality control process is devised to detect, quantify, and mitigate instances of partially/fully misclassified planar and pole-like features. Experimental results from airborne and terrestrial laser scanning as well as image-based point clouds are presented to illustrate the performance of the proposed segmentation and quality control framework.

A threshold auto-adjustment algorithm of feature points extraction based on grid

Science.gov (United States)

Yao, Zili; Li, Jun; Dong, Gaojie

2018-02-01

When dealing with high-resolution digital images, detection of feature points is usually the very first important step. Valid feature points depend on the threshold. If the threshold is too low, plenty of feature points will be detected, and they may be aggregated in the rich texture regions, which consequently not only affects the speed of feature description, but also aggravates the burden of following processing; if the threshold is set high, the feature points in poor texture area will lack. To solve these problems, this paper proposes a threshold auto-adjustment method of feature extraction based on grid. By dividing the image into numbers of grid, threshold is set in every local grid for extracting the feature points. When the number of feature points does not meet the threshold requirement, the threshold will be adjusted automatically to change the final number of feature points The experimental results show that feature points produced by our method is more uniform and representative, which avoids the aggregation of feature points and greatly reduces the complexity of following work.

Enhancement of precision and reduction of measuring points in tomographic reconstructions

International Nuclear Information System (INIS)

Lustfeld, H.; Hirschfeld, J.A.; Reissel, M.; Steffen, B.

2011-01-01

Accurate external measurements are required in tomographic problems to obtain a reasonable knowledge of the internal structures. Crucial is the distribution of the external measuring points. We suggest a procedure how to systematically optimize this distribution viz. to increase the precision (i.e. to shrink error bars) of the reconstruction by detecting the important and by eliminating the irrelevant measuring points. In a realistic numerical example we apply our scheme to magnetotomography of fuel cells. The result is striking: Starting from a smooth distribution of measuring points on a surface of a cuboid around the fuel cell, the number of measuring points can systematically be reduced by more than 90%. At the same time the precision increases by a factor of nearly 3.

Reanimating Storywork: Indigenous Elders’ Reflections on Leadership by Norma Rose Point

OpenAIRE

Point, Norma Rose

2011-01-01

xwmuthkwey’um Musqueam Elder Norma Rose Point discusses the importance of child rearing, caring for others, and traditional values in relation to leadership. Point elaborates on how she has surpassed experiences of racism, and how she has learnt to understand racism. Themes: caring for others; role modelling; collective approach to leadership-intergenerational advisory; communication; positive self-concept; relationship to the land; racism; perseverance; practice, training; caring for heal...

Information-theoretic approach to uncertainty importance

International Nuclear Information System (INIS)

Park, C.K.; Bari, R.A.

1985-01-01

A method is presented for importance analysis in probabilistic risk assessments (PRA) for which the results of interest are characterized by full uncertainty distributions and not just point estimates. The method is based on information theory in which entropy is a measure of uncertainty of a probability density function. We define the relative uncertainty importance between two events as the ratio of the two exponents of the entropies. For the log-normal and log-uniform distributions the importance measure is comprised of the median (central tendency) and of the logarithm of the error factor (uncertainty). Thus, if accident sequences are ranked this way, and the error factors are not all equal, then a different rank order would result than if the sequences were ranked by the central tendency measure alone. As an illustration, the relative importance of internal events and in-plant fires was computed on the basis of existing PRA results

Fixed Points

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

Demerit points systems.

NARCIS (Netherlands)

2006-01-01

In 2012, 21 of the 27 EU Member States had some form of demerit points system. In theory, demerit points systems contribute to road safety through three mechanisms: 1) prevention of unsafe behaviour through the risk of receiving penalty points, 2) selection and suspension of the most frequent

Early history of the different forms of neurofibromatosis from ancient Egypt to the British Empire and beyond: First descriptions, medical curiosities, misconceptions, landmarks, and the persons behind the syndromes.

Science.gov (United States)

Ruggieri, Martino; Praticò, Andrea D; Caltabiano, Rosario; Polizzi, Agata

2018-03-01

The earliest examples of neurofibromatosis (in this case type 1, NF1) can be traced in the Ebers Papyrus (Ancient Egypt, 1.500 B.C.), in a Hellenistic statuette (Smyrna, 323 B.C.), in the coinage of the Parthians kings (247 B.C.) and in some 13th century monks' drawings. These earlier examples are somewhat less well defined as compared to the most recent better defined reports credited as having NF1 including an Inca child mummy (1480-1650 AD), Ulisse Aldrovandi's homuncio ("Monstrorum Historia", 1592 A.D.) with mosaic NF1 or the illustrations seen in the 18th century "Buffon's Histoire Naturelle" and "Cruveilhier's Anatomie Pathologique du Corps Human". The first English language report on NF1 was made by Akenside in 1768 and the first systematic review by Robert William Smith in 1849, while Virchow's pupil, Friedrich Daniel von Recklinghausen, in 1882, was the first to understand the origin of skin tumors and to name them neurofibromas. The touching story of Joseph C. Merrick (the "Elephant man," (who had Proteus syndrome and not NF1), in 1884, played an important role in the later misconception of NF1, as did the novel by Vicotr Hugo on the hunchback Quasimodo. The studies by van der Hoeve (1921), Yakovlev and Guthrie (1931), and Van Bogaert (1935), categorized "von Recklinghausen's" neurofibromatosis among the phakomatoses and the neurocutaneous syndromes. The first known mention of an acoustic neuroma (at autopsy) is attributed to Eduard Sandifort (1777 AD) while John H. Wishart made the earliest autoptic description of neurofibromatosis type 2 (NF2), in 1822, in a 21-year-old man with bilateral acoustic neuromas, who manifested signs since his infancy (Wishart subtype NF2). Smith likely described the first case of schwannomatosis in 1849. Older, Virchow, von Recklinghausen, and Verocay first classified "neuromas" and Masson and Penfield first used the word "schwannoma" taking it from Theodore Schwann's works. In 1903 Henneberg and Koch described NF2 in detail

Impact of video-endoscopy on the results of retrosigmoid-transmeatal microsurgery of vestibular schwannoma: prospective study

Czech Academy of Sciences Publication Activity Database

Chovanec, M.; Zvěřina, E.; Profant, Oliver; Skřivan, J.; Čakrt, O.; Lisý, J.; Betka, J.

2013-01-01

Roč. 270, č. 4 (2013), s. 1277-1284 ISSN 0937-4477 Grant - others:GA MZd(CZ) NS9909 Institutional support: RVO:68378041 Keywords : vestibular schwannoma * acoustic neuroma * endoscopy-assisted microsurgery Subject RIV: FH - Neurology Impact factor: 1.608, year: 2013

The effect of six-point one-particle reducible local interactions in the dual fermion approach

International Nuclear Information System (INIS)

Katanin, A A

2013-01-01

We formulate the dual fermion approach for strongly correlated electronic systems in terms of the lattice and dual effective interactions, obtained by using the covariation splitting formula. This allows us to consider the effect of six-point one-particle reducible interactions, which are usually neglected by the dual fermion approach. We show that the consideration of one-particle reducible six-point (as well as higher order) vertices is crucially important for the diagrammatic consistency of this approach. In particular, the relation between the dual and lattice self-energy, derived in the dual fermion approach, implicitly accounts for the effect of the diagrams, containing six-point and higher order local one-particle reducible vertices, and should be applied with caution, if these vertices are neglected. Apart from that, the treatment of the self-energy feedback is also modified by six-point and higher order vertices; these vertices are also important to account for some non-local corrections to the lattice self-energy, which have the same order in the local four-point vertices as the diagrams usually considered in the approach. These observations highlight an importance of six-point and higher order vertices in the dual fermion approach, and call for the development of new schemes of treatment of non-local fluctuations, which are based on one-particle irreducible quantities. (paper)

Performance testing of 3D point cloud software

Science.gov (United States)

Varela-González, M.; González-Jorge, H.; Riveiro, B.; Arias, P.

2013-10-01

LiDAR systems are being used widely in recent years for many applications in the engineering field: civil engineering, cultural heritage, mining, industry and environmental engineering. One of the most important limitations of this technology is the large computational requirements involved in data processing, especially for large mobile LiDAR datasets. Several software solutions for data managing are available in the market, including open source suites, however, users often unknown methodologies to verify their performance properly. In this work a methodology for LiDAR software performance testing is presented and four different suites are studied: QT Modeler, VR Mesh, AutoCAD 3D Civil and the Point Cloud Library running in software developed at the University of Vigo (SITEGI). The software based on the Point Cloud Library shows better results in the loading time of the point clouds and CPU usage. However, it is not as strong as commercial suites in working set and commit size tests.

Performance testing of 3D point cloud software

Directory of Open Access Journals (Sweden)

M. Varela-González

2013-10-01

Full Text Available LiDAR systems are being used widely in recent years for many applications in the engineering field: civil engineering, cultural heritage, mining, industry and environmental engineering. One of the most important limitations of this technology is the large computational requirements involved in data processing, especially for large mobile LiDAR datasets. Several software solutions for data managing are available in the market, including open source suites, however, users often unknown methodologies to verify their performance properly. In this work a methodology for LiDAR software performance testing is presented and four different suites are studied: QT Modeler, VR Mesh, AutoCAD 3D Civil and the Point Cloud Library running in software developed at the University of Vigo (SITEGI. The software based on the Point Cloud Library shows better results in the loading time of the point clouds and CPU usage. However, it is not as strong as commercial suites in working set and commit size tests.

Collaborative Indoor Access Point Localization Using Autonomous Mobile Robot Swarm.

Science.gov (United States)

Awad, Fahed; Naserllah, Muhammad; Omar, Ammar; Abu-Hantash, Alaa; Al-Taj, Abrar

2018-01-31

Localization of access points has become an important research problem due to the wide range of applications it addresses such as dismantling critical security threats caused by rogue access points or optimizing wireless coverage of access points within a service area. Existing proposed solutions have mostly relied on theoretical hypotheses or computer simulation to demonstrate the efficiency of their methods. The techniques that rely on estimating the distance using samples of the received signal strength usually assume prior knowledge of the signal propagation characteristics of the indoor environment in hand and tend to take a relatively large number of uniformly distributed random samples. This paper presents an efficient and practical collaborative approach to detect the location of an access point in an indoor environment without any prior knowledge of the environment. The proposed approach comprises a swarm of wirelessly connected mobile robots that collaboratively and autonomously collect a relatively small number of non-uniformly distributed random samples of the access point's received signal strength. These samples are used to efficiently and accurately estimate the location of the access point. The experimental testing verified that the proposed approach can identify the location of the access point in an accurate and efficient manner.

Common intersection points in dense fluids via equations of state

International Nuclear Information System (INIS)

Parsafar, G. A.; Noorian, R.

2001-01-01

Some new of state which are derived for dense fluids in recent years, namely the linear isotherm regularity, the dense system equation of state, Ihm-Song-Mason equation of state, and a newly derived semi-empirical equation of state have used to investigate the common intersection point of isobaric expansivity (α p ) in dense fluids. We have shown that the accuracy of these equations of state in predicting such a common intersection point is reduced from the new semi-imperial equation of state, dense system equation of state, linear isotherm regularity, to Ihm-Song-Mason equation of state. respectively. Form physical point of view, the van der Waals equation of state is used to investigate such an intersection point. It is shown that the van der Waals repulsion forces and temperature dependency of the effective molecular diameter are important for existence of this common point. Finally, we have shown that the common intersection points of the isotherms of thermal pressure coefficient, the isotherms of heat capacity at constant volume, and the iso chores of internal pressure for a fluid are related to each other. Also, the common intersection points of the reduced bulk modulus and 1/(Tα p ) for isotherms of a fluid both appear at the same density

Extracurricular Activities and Their Effect on the Student's Grade Point Average: Statistical Study

Science.gov (United States)

Bakoban, R. A.; Aljarallah, S. A.

2015-01-01

Extracurricular activities (ECA) are part of students' everyday life; they play important roles in students' lives. Few studies have addressed the question of how student engagements to ECA affect student's grade point average (GPA). This research was conducted to know whether the students' grade point average in King Abdulaziz University,…

The Influence of the Tri-reference Points on Fairness and Satisfaction Perception

Directory of Open Access Journals (Sweden)

Lei Zhao

2018-02-01

Full Text Available We examined the influence of three reference points (minimum requirements [MR], the status quo [SQ], and goal [G] proposed by the tri-reference point (TRP theory on fairness and satisfaction perceptions of pay in three laboratory experiments. To test the effects, we manipulated these three reference points both implicitly (Experiment 1 and explicitly (Experiments 2 and 3. We also provided the information of the salary offered to a peer person that was lower than, equal to, or higher than the salary offer to the participant. As hypothesized, the results demonstrated the important role of these reference points in judging the fairness of and satisfaction with pay when they were explicitly set (an interaction between reference points and social comparison in Experiments 2 and 3, but not in Experiment 1. Participants altered their judgments when the salary was in different regions. When the salary was below MR, participants perceived very low fairness and satisfaction, even when the offer was equal to/exceeded others. When the salary was above G, participants perceived much higher fairness and satisfaction, even with disadvantageous inequality. Participants were more impacted when they were explicitly instructed of the reference points (Experiments 2 and 3 than when they were not (Experiment 1. Moreover, MR appeared to be the most important, followed by G. A Salary below MR was judged as very unacceptable, with very low fairness and satisfaction ratings.

Revisiting the fundamentals of single point incremental forming by

DEFF Research Database (Denmark)

Silva, Beatriz; Skjødt, Martin; Martins, Paulo A.F.

2008-01-01

Knowledge of the physics behind the fracture of material at the transition between the inclined wall and the corner radius of the sheet is of great importance for understanding the fundamentals of single point incremental forming (SPIF). How the material fractures, what is the state of strain...

Hematological clozapine monitoring with a point-of-care device

DEFF Research Database (Denmark)

Nielsen, Jimmi; Thode, Dorrit; Stenager, Elsebeth

2012-01-01

for several reasons, perhaps most importantly because of the mandatory hematological monitoring. The Chempaq Express Blood Counter (Chempaq XBC) is a point-of-care device providing counts of white blood cells (WBC) and granulocytes based on a capillary blood sampling. A randomized cross-over trial design...

Fractional charge and inter-Landau-level states at points of singular curvature.

Science.gov (United States)

Biswas, Rudro R; Son, Dam Thanh

2016-08-02

The quest for universal properties of topological phases is fundamentally important because these signatures are robust to variations in system-specific details. Aspects of the response of quantum Hall states to smooth spatial curvature are well-studied, but challenging to observe experimentally. Here we go beyond this prevailing paradigm and obtain general results for the response of quantum Hall states to points of singular curvature in real space; such points may be readily experimentally actualized. We find, using continuum analytical methods, that the point of curvature binds an excess fractional charge and sequences of quantum states split away, energetically, from the degenerate bulk Landau levels. Importantly, these inter-Landau-level states are bound to the topological singularity and have energies that are universal functions of bulk parameters and the curvature. Our exact diagonalization of lattice tight-binding models on closed manifolds demonstrates that these results continue to hold even when lattice effects are significant. An important technological implication of these results is that these inter-Landau-level states, being both energetically and spatially isolated quantum states, are promising candidates for constructing qubits for quantum computation.

Publication point indicators

DEFF Research Database (Denmark)

Elleby, Anita; Ingwersen, Peter

2010-01-01

; the Cumulated Publication Point Indicator (CPPI), which graphically illustrates the cumulated gain of obtained vs. ideal points, both seen as vectors; and the normalized Cumulated Publication Point Index (nCPPI) that represents the cumulated gain of publication success as index values, either graphically......The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdisciplinary Danish Institute of International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators...... with novel publication point indicators (PPIs) that are formalized and exemplified. Two diachronic citation windows are applied: 2006-07 and 2006-08. Web of Science (WoS) as well as Google Scholar (GS) are applied to observe the cite delay and citedness for the different document types published by DIIS...

Beyond the Point One Zero World

DEFF Research Database (Denmark)

Søndergaard, Morten

2009-01-01

, however intuitive they may be. Art and everything we do in everyday life – and in science, for that matter - is only dealing with a point zero one world. It is as if a silent big bang occurred, alongside the catastrophe that created our universe, and scattered the elements and building stones of any...... of astronomical and meteorological forces of nature. Indeed, these forces are perfect examples of realities beyond the point one zero world. Thorbjørn Laustens works from the premise, that technological means and artistic resources are the only limited resources of information that are available. In fact, Lausten......When we want to express something important, we say that we have something ‘on our mind’. We tend to attribute the same qualities to art and the artist – that what they are doing should mean something and bring new insights about our known world and reality to the minds of the beholders...

A decision-oriented measure of uncertainty importance for use in PSA

International Nuclear Information System (INIS)

Poern, Kurt

1997-01-01

For the interpretation of the results of probabilistic risk assessments it is important to have measures which identify the basic events that contribute most to the frequency of the top event but also to identify basic events that are the main contributors to the uncertainty in this frequency. Both types of measures, often called Importance Measure and Measure of Uncertainty Importance, respectively, have been the subject of interest for many researchers in the reliability field. The most frequent mode of uncertainty analysis in connection with probabilistic risk assessment has been to propagate the uncertainty of all model parameters up to an uncertainty distribution for the top event frequency. Various uncertainty importance measures have been proposed in order to point out the parameters that in some sense are the main contributors to the top event distribution. The new measure of uncertainty importance suggested here goes a step further in that it has been developed within a decision theory framework, thereby providing an indication of on what basic event it would be most valuable, from the decision-making point of view, to procure more information

Measuring the exhaust gas dew point of continuously operated combustion plants

Energy Technology Data Exchange (ETDEWEB)

Fehler, D.

1985-07-16

Low waste-gas temperatures represent one means of minimizing the energy consumption of combustion facilities. However, condensation should be prevented to occur in the waste gas since this could result in a destruction of parts. Measuring the waste-gas dew point allows to control combustion parameters in such a way as to be able to operate at low temperatures without danger of condensation. Dew point sensors will provide an important signal for optimizing combustion facilities.

A three-point Taylor algorithm for three-point boundary value problems

NARCIS (Netherlands)

J.L. López; E. Pérez Sinusía; N.M. Temme (Nico)

2011-01-01

textabstractWe consider second-order linear differential equations $\\varphi(x)y''+f(x)y'+g(x)y=h(x)$ in the interval $(-1,1)$ with Dirichlet, Neumann or mixed Dirichlet-Neumann boundary conditions given at three points of the interval: the two extreme points $x=\\pm 1$ and an interior point

The IgA nephropathy Biobank. An important starting point for the genetic dissection of a complex trait

Directory of Open Access Journals (Sweden)

Alexopoulos Efstathios

2005-12-01

Full Text Available Abstract Background IgA nephropathy (IgAN or Berger's disease, is the most common glomerulonephritis in the world diagnosed in renal biopsied patients. The involvement of genetic factors in the pathogenesis of the IgAN is evidenced by ethnic and geographic variations in prevalence, familial clustering in isolated populations, familial aggregation and by the identification of a genetic linkage to locus IGAN1 mapped on 6q22–23. This study seems to imply a single major locus, but the hypothesis of multiple interacting loci or genetic heterogeneity cannot be ruled out. The organization of a multi-centre Biobank for the collection of biological samples and clinical data from IgAN patients and relatives is an important starting point for the identification of the disease susceptibility genes. Description The IgAN Consortium organized a Biobank, recruiting IgAN patients and relatives following a common protocol. A website was constructed to allow scientific information to be shared between partners and to divulge obtained data (URL: http://www.igan.net. The electronic database, the core of the website includes data concerning the subjects enrolled. A search page gives open access to the database and allows groups of patients to be selected according to their clinical characteristics. DNA samples of IgAN patients and relatives belonging to 72 multiplex extended pedigrees were collected. Moreover, 159 trios (sons/daughters affected and healthy parents, 1068 patients with biopsy-proven IgAN and 1040 healthy subjects were included in the IgAN Consortium Biobank. Some valuable and statistically productive genetic studies have been launched within the 5th Framework Programme 1998–2002 of the European project No. QLG1-2000-00464 and preliminary data have been published in "Technology Marketplace" website: http://www.cordis.lu/marketplace. Conclusion The first world IgAN Biobank with a readily accessible database has been constituted. The knowledge gained

Zero-point energy in bag models

International Nuclear Information System (INIS)

Milton, K.A.

1979-01-01

The zero-point (Casimir) energy of free vector (gluon) fields confined to a spherical cavity (bag) is computed. With a suitable renormalization the result for eight gluons is E = + 0.51/a. This result is substantially larger than that for a spherical shell (where both interior and exterior modes are present), and so affects Johnson's model of the QCD vacuum. It is also smaller than, and of opposite sign to, the value used in bag model phenomenology, so it will have important implications there. 1 figure

From racks to pointed Hopf algebras

OpenAIRE

Andruskiewitsch, Nicolás; Graña, Matı́as

2003-01-01

A fundamental step in the classification of finite-dimensional complex pointed Hopf algebras is the determination of all finite-dimensional Nichols algebras of braided vector spaces arising from groups. The most important class of braided vector spaces arising from groups is the class of braided vector spaces (CX, c^q), where C is the field of complex numbers, X is a rack and q is a 2-cocycle on X with values in C^*. Racks and cohomology of racks appeared also in the work of topologists. This...

Georeferenced Point Clouds: A Survey of Features and Point Cloud Management

Directory of Open Access Journals (Sweden)

Johannes Otepka

2013-10-01

Full Text Available This paper presents a survey of georeferenced point clouds. Concentration is, on the one hand, put on features, which originate in the measurement process themselves, and features derived by processing the point cloud. On the other hand, approaches for the processing of georeferenced point clouds are reviewed. This includes the data structures, but also spatial processing concepts. We suggest a categorization of features into levels that reflect the amount of processing. Point clouds are found across many disciplines, which is reflected in the versatility of the literature suggesting specific features.

A falling of the veils: turning points and momentous turning points in leadership and the creation of CSR

OpenAIRE

Hemingway, C.; Starkey, Kenneth

2017-01-01

This article uses the life stories approach to leadership and leadership development. Using exploratory, qualitative data from a Forbes Global 2000 and FTSE 100 company, we discuss the role of the turning point (TP) as an important antecedent of leadership in corporate social responsibility. We argue that TPs are causally efficacious, linking them to the development of life narratives concerned with an evolving sense of personal identity. Using both a multi-disciplinary perspective and a mult...

Influence of the burning point on the dew point in a diesel engine

Energy Technology Data Exchange (ETDEWEB)

Teetz, C.

1982-06-01

A computation on the influence of the ignition point on the dew point in a cylinder of a diesel engine is presented. The cylinder-pressure diagrams are shown. The results of computation are given. A later ignition point diminishes the area with cylinder wall temperatures below the dew point. The endangering by cylinder wall temperatures below the dew point is illustrated.

Point specificity in acupuncture

Directory of Open Access Journals (Sweden)

Choi Emma M

2012-02-01

Full Text Available Abstract The existence of point specificity in acupuncture is controversial, because many acupuncture studies using this principle to select control points have found that sham acupoints have similar effects to those of verum acupoints. Furthermore, the results of pain-related studies based on visual analogue scales have not supported the concept of point specificity. In contrast, hemodynamic, functional magnetic resonance imaging and neurophysiological studies evaluating the responses to stimulation of multiple points on the body surface have shown that point-specific actions are present. This review article focuses on clinical and laboratory studies supporting the existence of point specificity in acupuncture and also addresses studies that do not support this concept. Further research is needed to elucidate the point-specific actions of acupuncture.

Episiotomy Scar Endometriosis Diagnosed on Cytology - A Case ...

African Journals Online (AJOL)

2017-06-30

Jun 30, 2017 ... Dnyanada Kokode*, Anne Wilkinson, Sadhana Mahore and Trupti Dongre ... Endometriosis, the presence of functioning endometrial tissue outside the ... examination, a tender, irregular, raised nodule measuring .... hematoma, hypertrophic scar tissue, traumatic neuroma, ... CT and MRI seem to be useful in.

Point defects and transport properties in carbides

International Nuclear Information System (INIS)

Matzke, Hj.

1984-01-01

Carbides of transition metals and of actinides are interesting and technologically important. The transition-metal carbides (or carbonitrides) are extensively being used as hard materials and some of them are of great interest because of the high transition temperature for superconductivity, e.g. 17 K for Nb(C,N). Actinide carbides and carbonitrides, (U,Pu)C and (U,Pu)(C,N) are being considered as promising advanced fuels for liquid metal cooled fast breeder nuclear reactors. Basic interest exists in all these materials because of their high melting points (e.g. 4250 K for TaC) and the unusually broad range of homogeneity of nonstoichiometric compositions (e.g. from UCsub(0.9) to UCsub(1.9) at 2500 K). Interaction of point defects to clusters and short-range ordering have recently been studied with elastic neutron diffraction and diffuse scattering techniques, and calculations of energies of formation and interaction of point defects became available for selected carbides. Diffusion measurements also exist for a number of carbides, in particular for the actinide carbides. The existing knowledge is discussed and summarized with emphasis on informative examples of particular technological relevance. (Auth.)

Learning Points and Routes to Recommend Trajectories

OpenAIRE

Chen, Dawei; Ong, Cheng Soon; Xie, Lexing

2016-01-01

The problem of recommending tours to travellers is an important and broadly studied area. Suggested solutions include various approaches of points-of-interest (POI) recommendation and route planning. We consider the task of recommending a sequence of POIs, that simultaneously uses information about POIs and routes. Our approach unifies the treatment of various sources of information by representing them as features in machine learning algorithms, enabling us to learn from past behaviour. Info...

First impressions and beyond: marketing your practice in touch points--Part I.

Science.gov (United States)

Bisera, Cheryl

2012-01-01

Often medical administrators or providers call in a marketing expert when they feel the practice is lacking the growth they want. What's on their mind is usually how to bring in more patients, and they automatically look to external marketing strategies. However, one of the most important elements to successfully marketing a practice is making sure you haven't created a turnstile, where new patients are coming often but not returning or being converted into loyal, referring patients. When new patients are going as quickly as they are coming, you aren't building solid growth. Loyal, referring patients are powerful marketing assets-they are in the community speaking good of you and your practice from first-hand experience. You can create this atmosphere of loyal, referring patients by providing positive touch points that fulfill the needs of your patients. Touch points are the groundwork supporting other types of marketing. This article covers three important touch points that are crucial to a positive patient experience.

Hearing loss as an unusual consequence of metastatic gastric adenocarcinoma

Directory of Open Access Journals (Sweden)

CE Owers

2010-10-01

Full Text Available A sixty-one year old man was referred with a history of progressive dysphagia, vomiting and weight loss with some back pain. Upper gastrointestinal endoscopy and biopsies revealed a gastro-oesophageal junction adenocarcinoma. Despite the absence of metastatic disease on computed tomography, positron emission tomography demonstrated multiple vertebral and sternal deposits. He was reviewed in an ENT clinic with a sudden onset of hearing loss accompanied by dizziness, but no focal neurology. Magnetic resonance imaging identified bilateral 2cm lesions at the internal auditory meatus, consistent with a diagnosis of bilateral acoustic neuromas. The patient subsequently died of carcinomatosis and, because of the potential familial significance of bilateral acoustic neuromas, a limited post-mortem examination was carried out. Unexpectedly, this revealed bilateral adenocarcinoma metastases infiltrating the internal auditory meatus affecting the acoustic nerves. The authors believe this a very rare presentation of metastatic gastric disease.

Squamoid cystosis of pancreatic ducts: a variant of a newly-described cystic lesion, with evidence for an obstructive etiology

Directory of Open Access Journals (Sweden)

Wai Chin Foo

2014-09-01

Full Text Available We describe a 40-year-old man who was found to have a cystic mass in the pancreatic tail during workup for weight loss and abdominal discomfort. Although computed tomography scan showed a single cyst associated with dilatation of the main pancreatic duct, gross and histologic examination of the distal pancreatectomy specimen actually revealed a central cyst that was surrounded by multiple smaller cystic spaces. This distinctive appearance was formed from extensive cystic dilatation and squamous metaplasia of the native pancreatic duct system. Further, a traumatic neuroma was discovered near the junction between normal and abnormal parenchyma. We believe that this case represents a variant of the newly-described squamoid cyst of panreatic ducts which we term squamoid cystosis of pancreatic ducts. The presence of chronic pancreatitis and a traumatic neuroma supports the hypothesis that squamoid cysts are non-neoplastic lesions arising from prior duct obstruction.

7 CFR 319.55-7 - Importations by mail.

Science.gov (United States)

2010-01-01

... foreign mailing point by a special mailing tag directing the package to a Plant Protection and Quarantine... 7 Agriculture 5 2010-01-01 2010-01-01 false Importations by mail. 319.55-7 Section 319.55-7 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION...

Importing low-density ideas to high-density revitalisation

DEFF Research Database (Denmark)

Arnholtz, Jens; Ibsen, Christian Lyhne; Ibsen, Flemming

2016-01-01

Why did union officials from a high-union-density country like Denmark choose to import an organising strategy from low-density countries such as the US and the UK? Drawing on in-depth interviews with key union officials and internal documents, the authors of this article argue two key points. Fi...

Study on the fixed point in crustal deformation before strong earthquake

Science.gov (United States)

Niu, A.; Li, Y.; Yan, W. Mr

2017-12-01

Usually, scholars believe that the fault pre-sliding or expansion phenomenon will be observed near epicenter area before strong earthquake, but more and more observations show that the crust deformation nearby epicenter area is smallest(Zhou, 1997; Niu,2009,2012;Bilham, 2005; Amoruso et al., 2010). The theory of Fixed point t is a branch of mathematics that arises from the theory of topological transformation and has important applications in obvious model analysis. An important precursory was observed by two tilt-meter sets, installed at Wenchuan Observatory in the epicenter area, that the tilt changes were the smallest compared with the other 8 stations around them in one year before the Wenchuan earthquake. To subscribe the phenomenon, we proposed the minimum annual variation range that used as a topological transformation. The window length is 1 year, and the sliding length is 1 day. The convergence of points with minimum annual change in the 3 years before the Wenchuan earthquake is studied. And the results show that the points with minimum deformation amplitude basically converge to the epicenter region before the earthquake. The possible mechanism of fixed point of crustal deformation was explored. Concerning the fixed point of crust deformation, the liquidity of lithospheric medium and the isostasy theory are accepted by many scholars (Bott &Dean, 1973; Merer et al.1988; Molnar et al., 1975,1978; Tapponnier et al., 1976; Wang et al., 2001). To explain the fixed point of crust deformation before earthquakes, we study the plate bending model (Bai, et al., 2003). According to plate bending model and real deformation data, we have found that the earthquake rupture occurred around the extreme point of plate bending, where the velocities of displacement, tilt, strain, gravity and so on are close to zero, and the fixed points are located around the epicenter.The phenomenon of fixed point of crust deformation is different from former understandings about the

Design and evaluation of pointing devices; Gestaltung und Evaluation von koordinatengebenden Interaktionsgeraeten

Energy Technology Data Exchange (ETDEWEB)

Krauss, L.; Zuehlke, D. [Kaiserslautern Univ. (Germany)

2002-07-01

Pointing devices e.g. the computer mouse are gaining considerable importance in modern human-machine-systems as a major part of the interaction interface between human beings and machines. During the dialogues with window-based operating systems the human being - the user - moves the cursor to a certain position on the screen by means of pointing devices. Microsoft products like WINDOWS have asserted themselves in the meantime in office applications and are currently conquering the market of industrial control systems as well. In office applications the mouse has become established as the most important pointing device for interaction. However, an 'office mouse' is not really suitable in a manufacturing environment. Only a few investigations exist evaluating alternatives to the mouse, which are suitable for industrial applications. At the Center of Human-Machine-Interaction (ZMMI) of the Institute of Production Automation (pak) at the University of Kaiserslautern a comparative investigation was carried out for alternative pointing devices like mouse, mousepad, mousebutton, mousestick, trackball, joystick, touchscreen, digitizing tablet and keyboard to determine their industrial suitability. This paper presents the methods of investigation and the most important results. The known Fitts' law model is mainly used in the field of HCl for office applications in order to evaluate interaction devices. This paper presents the new method DEVICE and is applied in the field of HMI for the evaluation of pointing devices. Tests with DEVICE and Fitts' method were conducted with machine operators under industrial environments to determine the suitability of thirty different pointing devices. The comparison between DEVICE and Fitts' law model shows that the results of certain partial tests correlate with each other. DEVICE can be used as substitute for Fitts' law model and offers additional parameters such as e.g. error rates and pointing deviation

Focal points and principal solutions of linear Hamiltonian systems revisited

Science.gov (United States)

Šepitka, Peter; Šimon Hilscher, Roman

2018-05-01

In this paper we present a novel view on the principal (and antiprincipal) solutions of linear Hamiltonian systems, as well as on the focal points of their conjoined bases. We present a new and unified theory of principal (and antiprincipal) solutions at a finite point and at infinity, and apply it to obtain new representation of the multiplicities of right and left proper focal points of conjoined bases. We show that these multiplicities can be characterized by the abnormality of the system in a neighborhood of the given point and by the rank of the associated T-matrix from the theory of principal (and antiprincipal) solutions. We also derive some additional important results concerning the representation of T-matrices and associated normalized conjoined bases. The results in this paper are new even for completely controllable linear Hamiltonian systems. We also discuss other potential applications of our main results, in particular in the singular Sturmian theory.

Role of Erosion in Shaping Point Bars

Science.gov (United States)

Moody, J.; Meade, R.

2012-04-01

floods during a water year. Erosion often was preferential and removed part or all of pods at lower elevations, and in time left what appears to be a random arrangement of sediment pods forming the point bar. Thus, we conclude that the erosional process is as important as the deposition process in shaping the final form of the point bar, and that point bars are not uniformly aggradational or transgressive deposits of sediment in which the age of the deposit increases monotonically downward at all locations across the point bar.

The resilience of an operating point for a fusion power plant

Energy Technology Data Exchange (ETDEWEB)

Ward, David, E-mail: david.ward@ccfe.ac.uk; Kemp, Richard

2015-10-15

Highlights: • The need to control a power plant changes our view of the optimum design. • The need for control can be reduced by finding resilient design points. • It is important to include resilience and control in selecting design points. • Including these additional constraints reduces flexibility in choice of operating points. - Abstract: The operating point for fusion power plant design concepts is often determined by simultaneously satisfying the requirements of all of the main plant systems and finding an optimum solution, for instance the one with the lowest capital cost or cost of electricity. This static assessment takes no account of the sensitivity of that operating point to variations in key parameters and therefore includes no information about how difficult to adjust and control the chosen operating point may be. Control of the operation point is a large subject with much work still to be done, and is expected to play an increasing role in the future in choosing the optimum design point. Here we present results of two analyses: one relates to the ability to load follow, that is, to vary the power production in the light of varying demands for power from the electricity network; the other investigates in simple terms what choices we can make to improve the resilience of static operating points.

Genetic aspects and classification of important Canadian uranium deposits

International Nuclear Information System (INIS)

McMillan, R.H.

1978-01-01

A classification of important uranium deposits which utilizes both genetic and descriptive criteria is presented. The dual aspect is useful because, while the non-genetic nomenclature for the different deposit types is amenable to various interpretations, the critical characteristics of each deposit can be analyzed to clarify various genetic points. Although the classification is intended primarily for Canadian uranium deposits, most of the important deposit types known elsewhere can be accommodated. (auth)

Genetic aspects and classification of important Canadian uranium deposits

International Nuclear Information System (INIS)

McMillan, R.H.

1978-01-01

A classification of important uranium deposits which utilizes both genetic and descriptive criteria is presented. The dual aspect is useful because, while the non-genetic nomenclature for the different deposit types is amenable to various interpretations, the critical characteristics of each deposit type can be analyzed to clarify various genetic points. Although the classification is intended primarily for Canadian uranium deposits, most of the important deposit types known elsewhere can be accommodated. (author)

Point prevalence survey of antimicrobial utilization in a Canadian tertiary-care teaching hospital

Directory of Open Access Journals (Sweden)

Colin Lee

2015-06-01

Conclusion: This prospective point prevalence survey provided important baseline information on antimicrobial use within a large tertiary care teaching hospital and identified potential targets for future antimicrobial stewardship initiatives. A multi-center point prevalence survey should be considered to identify patterns of antimicrobial use in Canada and to establish the first steps toward international antimicrobial surveillance.

Pointing gesture in a bird- merely instrumental or a cognitively complex behavior?

Directory of Open Access Journals (Sweden)

Gisela KAPLAN

2011-08-01

Full Text Available Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cognitive abilities rivaling those of apes, and their brain structures and functions show putative preconditions for referential gestural signaling (i.e. mirror neurons, links of vocal learning nuclei to discrete brain areas active during limb and body movements. The results reported are based on trials testing predator detection and responses to a taxidermic model of a wedge-tailed eagle by Australian magpies Gymnorhina tibicen. Magpies were subjected to three conditions of finding this model in their territory (open, sheltered and hidden. In the sheltered and hidden conditions, the discoverer simultaneously engaged in alarm calls and beak pointing, a behavior that has not been described previously. Other group members at once assembled and, after watching the first bird, adopted the same posture by pointing to the location of the intruder. The question is whether beak and body movements orienting towards important stimuli or events are instances of arousal, imitation or intentional communication. The latter presupposes that onlookers interpret the signal and respond by altering their own behavior appropriate to the original stimulus and not merely by imitating the first signaler. Evidence presented here indicates that the act of pointing may well be a complex cognitive behavior, i.e., an intentional and referential signal, showing that pointing is not limited to having hands and arms [Current Zoology 57 (4: 453–467, 2011].

A Potential Role of Chronic Exposure to Extremely Low-Frequency Electromagnetic Fields in Triggering Persistent Pain Post Breast Cancer Surgery: A Review

Directory of Open Access Journals (Sweden)

Azadeh Stark

2017-10-01

Full Text Available Persistent Pain after Breast Cancer Surgery (PPBCS ranks second to amputation of extremities for neuropathic chronic pain. PPBCS is associated with the formation of intercostobrachial neuroma bulbs along the lateral chest. These neuroma bulbs are either un-/thinly myelinated and express hypersensitivity to environmental stimuli. Hypersensitivity is manifested as spontaneous pain in response to innocuous stimuli and exaggerating pain in response to noxious stimuli. Excision of neuromas, a common intervention to alleviate pain, has been reported as ineffective. Experience of individuals with amputation of extremities and experimental models of human nerve injuries confirm anthropogenic EMF evoke excruciating pain. Findings from invitro and animal studies clearly support that EMF exposure depolarizes cell membranes, interrupts voltage gated calcium channels which then activates peripheral sensory neurons and initiates propagation of a train of action potentials along the axons of primary afferent nerve fibers. The World Health Organization guidelines, established based on approximation of the human anatomy are limited and assumes no potential compounding effects of nerve injuries or alterations of physiological milieu of tissues. The objective of this review is to direct the attention of the medical community to the potential role of anthropogenic EMF as a risk factor for persistent pain after breast surgery. Patients rely heavily on the recommendations of their providers to manage their pain. The current epidemic of opioid abuse in the US has been partially attributed to the high prescription rate of opioid-based pain killers. Understanding the potential triggers of chronic pain can reduce dependency on pharmaceutical agents.

APP/SOD1 overexpressing mice present reduced neuropathic pain sensitivity.

Science.gov (United States)

Kotulska, Katarzyna; Larysz-Brysz, Magdalena; LePecheur, Marie; Marcol, Wiesław; Olakowska, Edyta; Lewin-Kowalik, Joanna; London, Jacqueline

2011-07-15

There are controversies regarding pain expression in mentally disabled people, including Down syndrome patients. The aim of this study was to examine neuropathic pain-related behavior and peripheral nerve regeneration in mouse model of Down syndrome. Sciatic nerves of double transgenic mice, overexpressing both amyloid precursor protein (APP) and Cu/Zn superoxide dismutase (SOD1) genes, and FVB/N wild type mice were transected and immediately resutured. Evaluation of autotomy and functional recovery was carried out during 4-week follow-up. We found markedly less severe autotomy in transgenic animals, although the onset of autotomy was significantly delayed in control mice. Interestingly, neuroma formation at the injury site was significantly more prominent in transgenic animals. Sciatic function index outcome was better in transgenic mice than in wild-type group. Histological evaluation revealed no statistically significant differences in the number of GAP-43-positive growth cones and macrophages in the distal stump of the transected nerve between groups. However, in transgenic animals, the regenerating axons were arranged more chaotically. The number of Schwann cells in the distal stump of the transected nerves was significantly lower in transgenic mice. The number of surviving motoneurons was markedly decreased in transgenic group. We measured also the atrophy of denervated muscles and found it decreased in APP/SOD1 overexpressing mice. Taken together, in this model of Down syndrome, we observed increased neuroma formation and decreased autotomy after peripheral nerve injury. Our findings suggest that APP/SOD1 overexpressing mice are less sensitive for neuropathic pain associated with neuroma. Copyright © 2011 Elsevier Inc. All rights reserved.

Sideloading - Ingestion of Large Point Clouds Into the Apache Spark Big Data Engine

Science.gov (United States)

Boehm, J.; Liu, K.; Alis, C.

2016-06-01

In the geospatial domain we have now reached the point where data volumes we handle have clearly grown beyond the capacity of most desktop computers. This is particularly true in the area of point cloud processing. It is therefore naturally lucrative to explore established big data frameworks for big geospatial data. The very first hurdle is the import of geospatial data into big data frameworks, commonly referred to as data ingestion. Geospatial data is typically encoded in specialised binary file formats, which are not naturally supported by the existing big data frameworks. Instead such file formats are supported by software libraries that are restricted to single CPU execution. We present an approach that allows the use of existing point cloud file format libraries on the Apache Spark big data framework. We demonstrate the ingestion of large volumes of point cloud data into a compute cluster. The approach uses a map function to distribute the data ingestion across the nodes of a cluster. We test the capabilities of the proposed method to load billions of points into a commodity hardware compute cluster and we discuss the implications on scalability and performance. The performance is benchmarked against an existing native Apache Spark data import implementation.

Empirically Assessing the Importance of Characteristics of Accounting Students.

Science.gov (United States)

Baker, William M.; McGregor, Calvert C.

2000-01-01

Three employer groups (n=117), 47 accounting faculty, and 63 students rated the following characteristics of potential employees: master's degree, overall and accounting grade point average, personal integrity, communication skills, energy/drive/enthusiasm, and appearance. Employers and faculty considered integrity extremely important; students…

Flash Points of Secondary Alcohol and n-Alkane Mixtures.

Science.gov (United States)

Esina, Zoya N; Miroshnikov, Alexander M; Korchuganova, Margarita R

2015-11-19

The flash point is one of the most important characteristics used to assess the ignition hazard of mixtures of flammable liquids. To determine the flash points of mixtures of secondary alcohols with n-alkanes, it is necessary to calculate the activity coefficients. In this paper, we use a model that allows us to obtain enthalpy of fusion and enthalpy of vaporization data of the pure components to calculate the liquid-solid equilibrium (LSE) and vapor-liquid equilibrium (VLE). Enthalpy of fusion and enthalpy of vaporization data of secondary alcohols in the literature are limited; thus, the prediction of these characteristics was performed using the method of thermodynamic similarity. Additionally, the empirical models provided the critical temperatures and boiling temperatures of the secondary alcohols. The modeled melting enthalpy and enthalpy of vaporization as well as the calculated LSE and VLE flash points were determined for the secondary alcohol and n-alkane mixtures.

Collaborative Indoor Access Point Localization Using Autonomous Mobile Robot Swarm

Directory of Open Access Journals (Sweden)

Fahed Awad

2018-01-01

Full Text Available Localization of access points has become an important research problem due to the wide range of applications it addresses such as dismantling critical security threats caused by rogue access points or optimizing wireless coverage of access points within a service area. Existing proposed solutions have mostly relied on theoretical hypotheses or computer simulation to demonstrate the efficiency of their methods. The techniques that rely on estimating the distance using samples of the received signal strength usually assume prior knowledge of the signal propagation characteristics of the indoor environment in hand and tend to take a relatively large number of uniformly distributed random samples. This paper presents an efficient and practical collaborative approach to detect the location of an access point in an indoor environment without any prior knowledge of the environment. The proposed approach comprises a swarm of wirelessly connected mobile robots that collaboratively and autonomously collect a relatively small number of non-uniformly distributed random samples of the access point’s received signal strength. These samples are used to efficiently and accurately estimate the location of the access point. The experimental testing verified that the proposed approach can identify the location of the access point in an accurate and efficient manner.

Critical-point nuclei

International Nuclear Information System (INIS)

Clark, R.M.

2004-01-01

It has been suggested that a change of nuclear shape may be described in terms of a phase transition and that specific nuclei may lie close to the critical point of the transition. Analytical descriptions of such critical-point nuclei have been introduced recently and they are described briefly. The results of extensive searches for possible examples of critical-point behavior are presented. Alternative pictures, such as describing bands in the candidate nuclei using simple ΔK = 0 and ΔK = 2 rotational-coupling models, are discussed, and the limitations of the different approaches highlighted. A possible critical-point description of the transition from a vibrational to rotational pairing phase is suggested

Uses of risk importance measures

International Nuclear Information System (INIS)

Mankamo, T.; Poern, K.; Holmberg, J.

1991-05-01

Risk importance measures provide an understandable and practical way of presenting probabilistic safety analysis results which too often tend to remain abstract numbers without real insight into the content. The report clarifies the definitions, relationships and interpretations of the three most basic measures: Risk increase factor, risk decrease factor, and fractional contribution. The above three measures already cover the main types of risk importance measures. Many other importance measures presented in literature are close variants to some of these three measures. They are related in many cases so that, for a technical system considered, the two other measures can be derived from the one calculated first. However, the practical interpretations are different, and hence each three measures have their own uses and rights to existence. The fundamental aspect of importance measures is, that they express some specific influence of a basic event on the total risk. The basic failure or error events are the elements from which the reliability and risk models are constituted. The importance measures are relative, which is an advantage compared to absolute risk numbers, due to insensitivity with respect to quantification uncertainties. Therefore they are particularly adapted to give first hand guidance where to focus main interest from the system's risk and reliability point of view and wherefrom to continue the analysis with more sophisticated methods requiring more effort

A New Virtual Point Detector Concept for a HPGe detector

International Nuclear Information System (INIS)

Byun, Jong In; Yun, Ju Yong

2009-01-01

For last several decades, the radiation measurement and radioactivity analysis techniques using gamma detectors have been well established. Especially , the study about the detection efficiency has been done as an important part of gamma spectrometry. The detection efficiency depends strongly on source-to-detector distance. The detection efficiency with source-to-detector distance can be expressed by a complex function of geometry and physical characteristics of gamma detectors. In order to simplify the relation, a virtual point detector concept was introduced by Notea. Recently, further studies concerning the virtual point detector have been performed. In previous other works the virtual point detector has been considered as a fictitious point existing behind the detector end cap. However the virtual point detector position for the front and side of voluminous detectors might be different due to different effective central axis of them. In order to more accurately define the relation, therefore, we should consider the virtual point detector for the front as well as side and off-center of the detector. The aim of this study is to accurately define the relation between the detection efficiency and source-to-detector distance with the virtual point detector. This paper demonstrates the method to situate the virtual point detectors for a HPGe detector. The new virtual point detector concept was introduced for three area of the detector and its characteristics also were demonstrated by using Monte Carlo Simulation method. We found that the detector has three virtual point detectors except for its rear area. This shows that we should consider the virtual point detectors for each area when applying the concept to radiation measurement. This concept can be applied to the accurate geometric simplification for the detector and radioactive sources.

Is it necessary to import biofuels?

International Nuclear Information System (INIS)

Jensen, V.

1997-01-01

This conference paper discusses whether it is necessary to import biofuels into Denmark. As far as resources and capacities are concerned, the answer is no. From a commercial point of view the answer is yes. The electricity utilities and the district heating companies have established import as an alternative to domestic production of biomass. This is because agreements among suppliers had led to the absence of competition on price. This tendency to form cartels are seen for straw and chips. With pellets the situation is different; the market is controlled by the supply of shavings and filings from the furniture industry. This means that the market is very sensitive to changes in the export of furniture to Germany. Importing pellets has been difficult because of transportation problems. The prices of biofuels have been slightly falling. From 2005 the need for bioenergy will increase beyond the domestic resources of straw and chips. To secure that the Danish prices will not exceed those on the world market, in spite of the governmentally planned choice of fuels, some import of biomass will be required. 5 figs

Synthesis copolymer use to reduce pour point temperature of diamond crude oil

Science.gov (United States)

Than, Dao Viet; Chuong, Thai Hong; Tuy, Dao Quoc

2017-09-01

Diamond oil field is located in Block 01&02 Offshore Vietnam. Crude oil from Diamond Well Head Platform (WHP) is evacuated to FPSO via 20km 10" subsea flexible pipeline. The lowest seabed temperature in the field is 22°C, while the pour point temperature (PPT) of Diamond crude oil is very high (36°C) due to high paraffin content (25%). So studying to research a suitable Pour Point Depressant (PPD) for the crude oil is very important. The PPD must have ability to reduce pour point temperature of crude oil from 36°C to 21°C.

The Unicellular State as a Point Source in a Quantum Biological System

Directory of Open Access Journals (Sweden)

John S. Torday

2016-05-01

Full Text Available A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins.

Exceptional points enhance sensing in an optical microcavity

Science.gov (United States)

Chen, Weijian; Kaya Özdemir, Şahin; Zhao, Guangming; Wiersig, Jan; Yang, Lan

2017-08-01

Sensors play an important part in many aspects of daily life such as infrared sensors in home security systems, particle sensors for environmental monitoring and motion sensors in mobile phones. High-quality optical microcavities are prime candidates for sensing applications because of their ability to enhance light-matter interactions in a very confined volume. Examples of such devices include mechanical transducers, magnetometers, single-particle absorption spectrometers, and microcavity sensors for sizing single particles and detecting nanometre-scale objects such as single nanoparticles and atomic ions. Traditionally, a very small perturbation near an optical microcavity introduces either a change in the linewidth or a frequency shift or splitting of a resonance that is proportional to the strength of the perturbation. Here we demonstrate an alternative sensing scheme, by which the sensitivity of microcavities can be enhanced when operated at non-Hermitian spectral degeneracies known as exceptional points. In our experiments, we use two nanoscale scatterers to tune a whispering-gallery-mode micro-toroid cavity, in which light propagates along a concave surface by continuous total internal reflection, in a precise and controlled manner to exceptional points. A target nanoscale object that subsequently enters the evanescent field of the cavity perturbs the system from its exceptional point, leading to frequency splitting. Owing to the complex-square-root topology near an exceptional point, this frequency splitting scales as the square root of the perturbation strength and is therefore larger (for sufficiently small perturbations) than the splitting observed in traditional non-exceptional-point sensing schemes. Our demonstration of exceptional-point-enhanced sensitivity paves the way for sensors with unprecedented sensitivity.

Failure Probability Calculation Method Using Kriging Metamodel-based Importance Sampling Method

Energy Technology Data Exchange (ETDEWEB)

Lee, Seunggyu [Korea Aerospace Research Institue, Daejeon (Korea, Republic of); Kim, Jae Hoon [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

2017-05-15

The kernel density was determined based on sampling points obtained in a Markov chain simulation and was assumed to be an important sampling function. A Kriging metamodel was constructed in more detail in the vicinity of a limit state. The failure probability was calculated based on importance sampling, which was performed for the Kriging metamodel. A pre-existing method was modified to obtain more sampling points for a kernel density in the vicinity of a limit state. A stable numerical method was proposed to find a parameter of the kernel density. To assess the completeness of the Kriging metamodel, the possibility of changes in the calculated failure probability due to the uncertainty of the Kriging metamodel was calculated.

What is the Point? Ethics, Truth and the Tractatus

DEFF Research Database (Denmark)

Christensen, Anne-Marie Søndergaard

2007-01-01

discourse is shaped by both subjective and objective concerns. Moving on, I unfold the subjective side of ethics by drawing on Stanley Cavell's notion of the point of an utterance, while the objective side will be presented via Diamond's writing on the importance of truth in ethics. My goal is to argue...

The registration of non-cooperative moving targets laser point cloud in different view point

Science.gov (United States)

Wang, Shuai; Sun, Huayan; Guo, Huichao

2018-01-01

Non-cooperative moving target multi-view cloud registration is the key technology of 3D reconstruction of laser threedimension imaging. The main problem is that the density changes greatly and noise exists under different acquisition conditions of point cloud. In this paper, firstly, the feature descriptor is used to find the most similar point cloud, and then based on the registration algorithm of region segmentation, the geometric structure of the point is extracted by the geometric similarity between point and point, The point cloud is divided into regions based on spectral clustering, feature descriptors are created for each region, searching to find the most similar regions in the most similar point of view cloud, and then aligning the pair of point clouds by aligning their minimum bounding boxes. Repeat the above steps again until registration of all point clouds is completed. Experiments show that this method is insensitive to the density of point clouds and performs well on the noise of laser three-dimension imaging.

Note to Budget Cutters: The Arts Are Good Business--Multiple Studies Point to Arts Education as an Important Economic Engine

Science.gov (United States)

Olson, Catherine Applefeld

2009-01-01

They say desperate times call for desperate measures. But in this time of economic uncertainty, the desperate cutting of budgets for arts funding and, by extension, all types of arts education, including music, is not prudent. That is the consensus of several national and local studies, which converge on a single point--that the arts actually can…

PATTERNS OF SEVEN AND COMPLICATED MALARIA IN CHILDREN

African Journals Online (AJOL)

GB

These tumors can arise from any nerve sheath origin. These tumors can ... made with other neural origin lesions, which could be neurofibroma and neuroma or muscular or ... capillaries. Senior Lecturer, Department of Oral Medicine & Radiology, AECS Maaruti College of Dental Sciences & Research. Centre, Bangalore.

Disease: H00247 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available racterized by parathyroid adenoma, gastrinoma, and pituitary adenoma. Gastrinomas are the most common type, leading... ganglion dysfunction, leading to megacolon. MEN4, also referred to as MENX, appe... in association with marfanoid habitus, mucosal neuromas, medullated corneal fibers and intestinal autonomic

Determination of dew point in natural gas; Determinacion del punto de rocio en el gas natural

Energy Technology Data Exchange (ETDEWEB)

Avila Calzada, S.; Marco Martinez, G.; Montenegro Soto, S. [ENAGAS (Spain)

1995-07-01

The natural gas can contain water and heavy hydrocarbons very dangerous for the equipments and the pipes. This is the reason of the importance of dew point. The value of this dew point is fixed in the supply contract conditions. This article studies the different evaluation methods, pointing out the advantages and disadvantages (Author)

[Dancing with Pointe Shoes: Characteristics and Assessment Criteria for Pointe Readiness].

Science.gov (United States)

Wanke, Eileen M; Exner-Grave, Elisabeth

2017-12-01

Training with pointe shoes is an integral part of professional dance education and ambitious hobby dancing. Pointe shoes - developed more than hundred years ago and almost unaltered since then - are highly specific and strike a balance between aesthetics, function, protection, and health care. Therefore, pointe readiness should be tested prior to all dance training or career training. Medical specialists are often confronted with this issue. Specific anatomical dance technique-orientated general conditional and coordinative preconditions as well as dance-technical prerequisites must be met by pointe readiness tests in order to keep traumatic injuries or long-term damage at a minimum. In addition to a (training) history, medical counselling sessions have come to include various tests that enable a reliable decision for or against pointe work. This article suggests adequate testing procedures (STT TEST), taking account of professional dancing as well as hobby dancing. © Georg Thieme Verlag KG Stuttgart · New York.

Comparison of Dose When Prescribed to Point A and Point H for Brachytherapy in Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Gang, Ji Hyeong; Gim, Il Hwan; Hwang, Seon Boong; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Gim, Gi Hwan; Lee, Ah Ram [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seou (Korea, Republic of)

2012-09-15

The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.

PolyWaTT: A polynomial water travel time estimator based on Derivative Dynamic Time Warping and Perceptually Important Points

Science.gov (United States)

Claure, Yuri Navarro; Matsubara, Edson Takashi; Padovani, Carlos; Prati, Ronaldo Cristiano

2018-03-01

Traditional methods for estimating timing parameters in hydrological science require a rigorous study of the relations of flow resistance, slope, flow regime, watershed size, water velocity, and other local variables. These studies are mostly based on empirical observations, where the timing parameter is estimated using empirically derived formulas. The application of these studies to other locations is not always direct. The locations in which equations are used should have comparable characteristics to the locations from which such equations have been derived. To overcome this barrier, in this work, we developed a data-driven approach to estimate timing parameters such as travel time. Our proposal estimates timing parameters using historical data of the location without the need of adapting or using empirical formulas from other locations. The proposal only uses one variable measured at two different locations on the same river (for instance, two river-level measurements, one upstream and the other downstream on the same river). The recorded data from each location generates two time series. Our method aligns these two time series using derivative dynamic time warping (DDTW) and perceptually important points (PIP). Using data from timing parameters, a polynomial function generalizes the data by inducing a polynomial water travel time estimator, called PolyWaTT. To evaluate the potential of our proposal, we applied PolyWaTT to three different watersheds: a floodplain ecosystem located in the part of Brazil known as Pantanal, the world's largest tropical wetland area; and the Missouri River and the Pearl River, in United States of America. We compared our proposal with empirical formulas and a data-driven state-of-the-art method. The experimental results demonstrate that PolyWaTT showed a lower mean absolute error than all other methods tested in this study, and for longer distances the mean absolute error achieved by PolyWaTT is three times smaller than empirical

Prospect theory, reference points, and health decisions

Directory of Open Access Journals (Sweden)

Alan Schwartz

2008-02-01

Full Text Available In preventative health decisions, such as the decision to undergo an invasive screening test or treatment, people may be deterred from selecting the test because its perceived disutility relative to not testing is greater than the utility associated with prevention of possible disease. The prospect theory editing operation, by which a decision maker's reference point is determined, can have important effects on the disutility of the test. On the basis of the prospect theory value function, this paper develops two approaches to reducing disutility by directing the decision maker's attention to either (actual past or (expected future losses that result in shifted reference points. After providing a graphical description of the approaches and a mathematical proof of the direction of their effect on judgment, we briefly illustrate the potential value of these approaches with examples from qualitative research on prostate cancer treatment decisions.

The predetermined sites of examination for tender points in fibromyalgia syndrome are frequently associated with myofascial trigger points

DEFF Research Database (Denmark)

Ge, Hongyou; Wang, Ying; Danneskiold-Samsøe, Bente

2010-01-01

. PERSPECTIVE: This article underlies the importance of active MTrPs in FMS patients. Most of the TP sites in FMS are MTrPs. Active MTrPs may serve as a peripheral generator of fibromyalgia pain and inactivation of active MTrPs may thus be an alternative for the treatment of FMS.......The aim of this present study is to test the hypotheses that the 18 predetermined sites of examination for tender points (TP sites) in fibromyalgia syndrome (FMS) are myofascial trigger points (MTrPs), and that the induced pain from active MTrPs at TP sites may mimic fibromyalgia pain. Each TP site......), but not latent MTrPs (r = -.001, P = .99), was positively correlated with spontaneous pain intensity in FMS. The current study provides first evidence that pain from active MTrPs at TP sites mimics fibromyalgia pain. MTrPs may relate to generalized increased sensitivity in FMS due to central sensitization...

Measurement of neutron importance by a dynamic method

International Nuclear Information System (INIS)

Dmitriev, V.M.; Matusevich, E.S.; Regushevskij, V.I.; Sazonov, S.P.; Usikov, D.A.

1977-01-01

A procedure is proposed for measuring neutron importance spatial distribution in a critical reactor by determining the parameters of its run-up with a constant neutron source. 252 Cf quasiisotropic point source was used. The measurements were performed at a critical assembly with a highly enriched uranium core and beryllium reflector. Importance distributions in critical and subsritical assemblies were compared for various degrees of subcriticality. Absolute normalization for the importance was obtained, and some new integral reactor characteristics were determined experimentally on its basis. An experimental data acquisition and processing system was developed on the basis of the ELECTRONIKA-100 computer. An algorithm was also developed for statistical treatment of the data. The importance distributions in critical and subcritical assemblies proved to coincide up to a rather deep subcriticality

MIMIC: An Innovative Methodology for Determining Mobile Laser Scanning System Point Density

Directory of Open Access Journals (Sweden)

Conor Cahalane

2014-08-01

Full Text Available Understanding how various Mobile Mapping System (MMS laser hardware configurations and operating parameters exercise different influence on point density is important for assessing system performance, which in turn facilitates system design and MMS benchmarking. Point density also influences data processing, as objects that can be recognised using automated algorithms generally require a minimum point density. Although obtaining the necessary point density impacts on hardware costs, survey time and data storage requirements, a method for accurately and rapidly assessing MMS performance is lacking for generic MMSs. We have developed a method for quantifying point clouds collected by an MMS with respect to known objects at specified distances using 3D surface normals, 2D geometric formulae and line drawing algorithms. These algorithms were combined in a system called the Mobile Mapping Point Density Calculator (MIMIC and were validated using point clouds captured by both a single scanner and a dual scanner MMS. Results from MIMIC were promising: when considering the number of scan profiles striking the target, the average error equated to less than 1 point per scan profile. These tests highlight that MIMIC is capable of accurately calculating point density for both single and dual scanner MMSs.

C-point and V-point singularity lattice formation and index sign conversion methods

Science.gov (United States)

Kumar Pal, Sushanta; Ruchi; Senthilkumaran, P.

2017-06-01

The generic singularities in an ellipse field are C-points namely stars, lemons and monstars in a polarization distribution with C-point indices (-1/2), (+1/2) and (+1/2) respectively. Similar to C-point singularities, there are V-point singularities that occur in a vector field and are characterized by Poincare-Hopf index of integer values. In this paper we show that the superposition of three homogenously polarized beams in different linear states leads to the formation of polarization singularity lattice. Three point sources at the focal plane of the lens are used to create three interfering plane waves. A radial/azimuthal polarization converter (S-wave plate) placed near the focal plane modulates the polarization states of the three beams. The interference pattern is found to host C-points and V-points in a hexagonal lattice. The C-points occur at intensity maxima and V-points occur at intensity minima. Modulating the state of polarization (SOP) of three plane waves from radial to azimuthal does not essentially change the nature of polarization singularity lattice as the Poincare-Hopf index for both radial and azimuthal polarization distributions is (+1). Hence a transformation from a star to a lemon is not trivial, as such a transformation requires not a single SOP change, but a change in whole spatial SOP distribution. Further there is no change in the lattice structure and the C- and V-points appear at locations where they were present earlier. Hence to convert an interlacing star and V-point lattice into an interlacing lemon and V-point lattice, the interferometer requires modification. We show for the first time a method to change the polarity of C-point and V-point indices. This means that lemons can be converted into stars and stars can be converted into lemons. Similarly the positive V-point can be converted to negative V-point and vice versa. The intensity distribution in all these lattices is invariant as the SOPs of the three beams are changed in an

Importance biasing quality criterion based on contribution response theory

International Nuclear Information System (INIS)

Borisov, N.M.; Panin, M.P.

2001-01-01

The report proposes a visual criterion of importance biasing both of forward and adjoint simulation. The similarity of contribution Monte Carlo and importance biasing random collision event distribution is proved. The conservation of total number of random trajectory crossings of surfaces, which separate the source and the detector is proposed as importance biasing quality criterion. The use of this criterion is demonstrated on the example of forward vs. adjoint importance biasing in gamma ray deep penetration problem. The larger amount of published data on forward field characteristics than on adjoint leads to the more accurate approximation of adjoint importance function in comparison to forward, for it adjoint importance simulation is more effective than forward. The proposed criterion indicates it visually, showing the most uniform distribution of random trajectory crossing events for the most effective importance biasing parameters and pointing to the direction of tuning importance biasing parameters. (orig.)

Non-uniqueness of the point of application of the buoyancy force

International Nuclear Information System (INIS)

Kliava, Janis; Megel, Jacques

2010-01-01

Even though the buoyancy force (also known as the Archimedes force) has always been an important topic of academic studies in physics, its point of application has not been explicitly identified yet. We present a quantitative approach to this problem based on the concept of the hydrostatic energy, considered here for a general shape of the cross-section of a floating body and for an arbitrary angle of heel. We show that the location of the point of application of the buoyancy force essentially depends (i) on the type of motion experienced by the floating body and (ii) on the definition of this point. In a rolling/pitching motion, considerations involving the rotational moment lead to a particular dynamical point of application of the buoyancy force, and for some simple shapes of the floating body this point coincides with the well-known metacentre. On the other hand, from the work-energy relation it follows that in the rolling/pitching motion the energetical point of application of this force is rigidly connected to the centre of buoyancy; in contrast, in a vertical translation this point is rigidly connected to the centre of gravity of the body. Finally, we consider the location of the characteristic points of the floating bodies for some particular shapes of immersed cross-sections. The paper is intended for higher education level physics teachers and students.

PowerPoint 2010 Bible

CERN Document Server

Wempen, Faithe

2010-01-01

Master PowerPoint and improve your presentation skills-with one book!. It's no longer enough to have slide after slide of text, bullets, and charts. It's not even enough to have good speaking skills if your PowerPoint slides bore your audience. Get the very most out of all that PowerPoint 2010 has to offer while also learning priceless tips and techniques for making good presentations in this new PowerPoint 2010 Bible. Well-known PowerPoint expert and author Faithe Wempen provides formatting tips; shows you how to work with drawings, tables, and SmartArt; introduces new collaboration tools; wa

EXTRACTION OF BUILDING BOUNDARY LINES FROM AIRBORNE LIDAR POINT CLOUDS

Directory of Open Access Journals (Sweden)

Y.-H. Tseng

2016-10-01

Full Text Available Building boundary lines are important spatial features that characterize the topographic maps and three-dimensional (3D city models. Airborne LiDAR Point clouds provide adequate 3D spatial information for building boundary mapping. However, information of boundary features contained in point clouds is implicit. This study focuses on developing an automatic algorithm of building boundary line extraction from airborne LiDAR data. In an airborne LiDAR dataset, top surfaces of buildings, such as roofs, tend to have densely distributed points, but vertical surfaces, such as walls, usually have sparsely distributed points or even no points. The intersection lines of roof and wall planes are, therefore, not clearly defined in point clouds. This paper proposes a novel method to extract those boundary lines of building edges. The extracted line features can be used as fundamental data to generate topographic maps of 3D city model for an urban area. The proposed method includes two major process steps. The first step is to extract building boundary points from point clouds. Then the second step is followed to form building boundary line features based on the extracted boundary points. In this step, a line fitting algorithm is developed to improve the edge extraction from LiDAR data. Eight test objects, including 4 simple low buildings and 4 complicated tall buildings, were selected from the buildings in NCKU campus. The test results demonstrate the feasibility of the proposed method in extracting complicate building boundary lines. Some results which are not as good as expected suggest the need of further improvement of the method.

UO3 deactivation end point criteria

International Nuclear Information System (INIS)

Stefanski, L.D.

1994-01-01

The UO 3 Deactivation End Point Criteria are necessary to facilitate the transfer of the UO 3 Facility from the Office of Facility Transition and Management (EM-60) to the office of Environmental Restoration (EM-40). The criteria were derived from a logical process for determining end points for the systems and spaces at the UO 3 , Facility based on the objectives, tasks, and expected future uses pertinent to that system or space. Furthermore, the established criteria meets the intent and supports the draft guidance for acceptance criteria prepared by EM-40, open-quotes U.S. Department of Energy office of Environmental Restoration (EM-40) Decontamination and Decommissioning Guidance Document (Draft).close quotes For the UO 3 Facility, the overall objective of deactivation is to achieve a safe, stable and environmentally sound condition, suitable for an extended period, as quickly and economically as possible. Once deactivated, the facility is kept in its stable condition by means of a methodical surveillance and maintenance (S ampersand M) program, pending ultimate decontamination and decommissioning (D ampersand D). Deactivation work involves a range of tasks, such as removal of hazardous material, elimination or shielding of radiation fields, partial decontamination to permit access for inspection, installation of monitors and alarms, etc. it is important that the end point of each of these tasks be established clearly and in advance, for the following reasons: (1) End points must be such that the central element of the deactivation objective - to achieve stability - is unquestionably achieved. (2) Much of the deactivation work involves worker exposure to radiation or dangerous materials. This can be minimized by avoiding unnecessary work. (3) Each task is, in effect, competing for resources with other deactivation tasks and other facilities. By assuring that each task is appropriately bounded, DOE's overall resources can be used most fully and effectively

Critical points for finite Fibonacci chains of point delta-interactions and orthogonal polynomials

International Nuclear Information System (INIS)

De Prunele, E

2011-01-01

For a one-dimensional Schroedinger operator with a finite number n of point delta-interactions with a common intensity, the parameters are the intensity, the n - 1 intercenter distances and the mass. Critical points are points in the parameters space of the Hamiltonian where one bound state appears or disappears. The study of critical points for Hamiltonians with point delta-interactions arranged along a Fibonacci chain is shown to be closely related to the study of the so-called Fibonacci operator, a discrete one-dimensional Schroedinger-type operator, which occurs in the context of tight binding Hamiltonians. These critical points are the zeros of orthogonal polynomials previously studied in the context of special diatomic linear chains with elastic nearest-neighbor interaction. Properties of the zeros (location, asymptotic behavior, gaps, ...) are investigated. The perturbation series from the solvable periodic case is determined. The measure which yields orthogonality is investigated numerically from the zeros. It is shown that the transmission coefficient at zero energy can be expressed in terms of the orthogonal polynomials and their associated polynomials. In particular, it is shown that when the number of point delta-interactions is equal to a Fibonacci number minus 1, i.e. when the intervals between point delta-interactions form a palindrome, all the Fibonacci chains at critical points are completely transparent at zero energy. (paper)

Poisson branching point processes

International Nuclear Information System (INIS)

Matsuo, K.; Teich, M.C.; Saleh, B.E.A.

1984-01-01

We investigate the statistical properties of a special branching point process. The initial process is assumed to be a homogeneous Poisson point process (HPP). The initiating events at each branching stage are carried forward to the following stage. In addition, each initiating event independently contributes a nonstationary Poisson point process (whose rate is a specified function) located at that point. The additional contributions from all points of a given stage constitute a doubly stochastic Poisson point process (DSPP) whose rate is a filtered version of the initiating point process at that stage. The process studied is a generalization of a Poisson branching process in which random time delays are permitted in the generation of events. Particular attention is given to the limit in which the number of branching stages is infinite while the average number of added events per event of the previous stage is infinitesimal. In the special case when the branching is instantaneous this limit of continuous branching corresponds to the well-known Yule--Furry process with an initial Poisson population. The Poisson branching point process provides a useful description for many problems in various scientific disciplines, such as the behavior of electron multipliers, neutron chain reactions, and cosmic ray showers

Interior point decoding for linear vector channels

International Nuclear Information System (INIS)

Wadayama, T

2008-01-01

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem

Interior point decoding for linear vector channels

Energy Technology Data Exchange (ETDEWEB)

Wadayama, T [Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, Aichi, 466-8555 (Japan)], E-mail: wadayama@nitech.ac.jp

2008-01-15

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter-symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem.

Laser Dew-Point Hygrometer

Science.gov (United States)

Matsumoto, Shigeaki; Toyooka, Satoru

1995-01-01

A rough-surface-type automatic dew-point hygrometer was developed using a laser diode and an optical fiber cable. A gold plate with 0.8 µ m average surface roughness was used as a surface for deposition of dew to facilitate dew deposition and prevent supersaturation of water vapor at the dew point. It was shown experimentally that the quantity of dew deposited can be controlled to be constant at any predetermined level, and is independent of the dew point to be measured. The dew points were measured in the range from -15° C to 54° C in which the temperature ranged from 0° C to 60° C. The measurement error of the dew point was ±0.5° C which was equal to below ±2% in relative humidity in the above dew-point range.

Factors influencing superimposition error of 3D cephalometric landmarks by plane orientation method using 4 reference points: 4 point superimposition error regression model.

Science.gov (United States)

Hwang, Jae Joon; Kim, Kee-Deog; Park, Hyok; Park, Chang Seo; Jeong, Ho-Gul

2014-01-01

Superimposition has been used as a method to evaluate the changes of orthodontic or orthopedic treatment in the dental field. With the introduction of cone beam CT (CBCT), evaluating 3 dimensional changes after treatment became possible by superimposition. 4 point plane orientation is one of the simplest ways to achieve superimposition of 3 dimensional images. To find factors influencing superimposition error of cephalometric landmarks by 4 point plane orientation method and to evaluate the reproducibility of cephalometric landmarks for analyzing superimposition error, 20 patients were analyzed who had normal skeletal and occlusal relationship and took CBCT for diagnosis of temporomandibular disorder. The nasion, sella turcica, basion and midpoint between the left and the right most posterior point of the lesser wing of sphenoidal bone were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Another 15 reference cephalometric points were also determined three times in the same image. Reorientation error of each landmark could be explained substantially (23%) by linear regression model, which consists of 3 factors describing position of each landmark towards reference axes and locating error. 4 point plane orientation system may produce an amount of reorientation error that may vary according to the perpendicular distance between the landmark and the x-axis; the reorientation error also increases as the locating error and shift of reference axes viewed from each landmark increases. Therefore, in order to reduce the reorientation error, accuracy of all landmarks including the reference points is important. Construction of the regression model using reference points of greater precision is required for the clinical application of this model.

An inversion-relaxation approach for sampling stationary points of spin model Hamiltonians

International Nuclear Information System (INIS)

Hughes, Ciaran; Mehta, Dhagash; Wales, David J.

2014-01-01

Sampling the stationary points of a complicated potential energy landscape is a challenging problem. Here, we introduce a sampling method based on relaxation from stationary points of the highest index of the Hessian matrix. We illustrate how this approach can find all the stationary points for potentials or Hamiltonians bounded from above, which includes a large class of important spin models, and we show that it is far more efficient than previous methods. For potentials unbounded from above, the relaxation part of the method is still efficient in finding minima and transition states, which are usually the primary focus of attention for atomistic systems

Fastklemt nerve som årsag til svære postoperative smerter fra arvæv

DEFF Research Database (Denmark)

Møller, Michael; Venzo, Alessandro

2014-01-01

Entrapment of a cutaneous nerve in a surgical scar may cause chronic post-operative pain. The condition presents with similar symptoms as a traumatic neuroma or as an anterior cutaneous nerve entrapment syndrome, which, however, is often idiopathic. We present a case, where entrapment of a cutane...

The Importance of Research in Educating About Music Therapy

OpenAIRE

Barbara L. Wheeler

2014-01-01

In this "Essay" article, the author explores some ways in which music therapy research is important in educating people—music therapists and those outside of music therapy—about music therapy. There are different levels and types of research, and different levels are appropriate at different points in the development of music therapy in a country. However, some type of music therapy research is important for the development of music therapy in all cases and in all situations and all countries...

Headache: an important factor associated with muscle soreness/pain at the two-year follow-up point among patients with major depressive disorder.

Science.gov (United States)

Hung, Ching-I; Liu, Chia-Yih; Yang, Ching-Hui; Wang, Shuu-Jiun

2016-01-01

No study has compared the associations of headache, anxiety, and depression at baseline with muscle soreness or pain (MS/P) at baseline and at the two-year follow-up point among outpatients with major depressive disorder (MDD). This study aimed to investigate the above issue. This study enrolled 155 outpatients with MDD at baseline, and 131 attended a two-year follow-up appointment. At baseline, migraine was diagnosed based on the International Classification of Headache Disorders, 2(nd) edition. MDD and anxiety disorders were diagnosed using the Structured Clinical Interview for DSM-IV-TR. The visual analog scale was used to evaluate the intensities of headache and MS/P in the neck, shoulder, back, upper limbs, and lower limbs. Depression and anxiety were evaluated using the Hospital Anxiety and Depression Scale. Multiple linear regressions were used to compare the associations of these factors with MS/P. Compared with anxiety disorders, migraine was more strongly associated with MS/P in all areas at baseline and in the upper and lower limbs at follow-up. Headache intensity at baseline was the factor most strongly associated with MS/P in all areas at baseline and follow-up after controlling for depression and anxiety. Headache intensity at baseline predicted MS/P at baseline and follow-up. Migraine and headache intensity are important factors related to MS/P at baseline and follow-up among patients with MDD. Integrating depression and headache treatment might be indicated to improve MS/P.

Learning power point 2000 easily

Energy Technology Data Exchange (ETDEWEB)

Mon, In Su; Je, Jung Suk

2000-05-15

This book introduces power point 2000, which gives descriptions what power point is, what we can do with power point 2000, is it possible to install power point 2000 in my computer? Let's run power point, basic of power point such as new presentation, writing letter, using text box, changing font size, color and shape, catching power user, insertion of word art and creating of new file. It also deals with figure, chart, graph, making multimedia file, presentation, know-how of power point for teachers and company workers.

Extracting valley-ridge lines from point-cloud-based 3D fingerprint models.

Science.gov (United States)

Pang, Xufang; Song, Zhan; Xie, Wuyuan

2013-01-01

3D fingerprinting is an emerging technology with the distinct advantage of touchless operation. More important, 3D fingerprint models contain more biometric information than traditional 2D fingerprint images. However, current approaches to fingerprint feature detection usually must transform the 3D models to a 2D space through unwrapping or other methods, which might introduce distortions. A new approach directly extracts valley-ridge features from point-cloud-based 3D fingerprint models. It first applies the moving least-squares method to fit a local paraboloid surface and represent the local point cloud area. It then computes the local surface's curvatures and curvature tensors to facilitate detection of the potential valley and ridge points. The approach projects those points to the most likely valley-ridge lines, using statistical means such as covariance analysis and cross correlation. To finally extract the valley-ridge lines, it grows the polylines that approximate the projected feature points and removes the perturbations between the sampled points. Experiments with different 3D fingerprint models demonstrate this approach's feasibility and performance.

MR imaging of cranial nerve schwannomas

International Nuclear Information System (INIS)

Shapiro, M.; Peyster, R.; Cross, R.R.; Charles, J.; Murtagh, R.; Shapiro, R.; Chyatte, D.

1988-01-01

One of the major advantages of magnetic resonance (MR) imaging over other imaging modalities is direct visualization of the cranial nerves. This is best accomplished with thin-section, contiguous T1-weighted images. They report a series of 75 cranial nerve neuromas, including 47 of the eighth nerve and a mixture of schwannomas involving all other cranial nerves (excluding the fourth). All tumors demonstrated at least some area of increased signal (equal to or greater than that of cerebrospinal fluid) on T2-weighted images. This fact enabled them to differentiate schwannomas from neoplasms (lymphoma, meningioma, sarcoma) that may be isointense on T2-weighted pulse sequences. Many of the lesions had areas of low signal intermixed with predominantly high signal (on T2-weighted images). The pathologic evaluation of these areas of decreased signal revealed predominant fibrosis. In addition, some of the neuromas had a cystic component. Gadolinium-enhanced MR imaging may permit detection when the nerve is still normal in size

An evidence-based case of acoustic/vestibular schwannoma

Directory of Open Access Journals (Sweden)

Girish Gupta

2015-01-01

Full Text Available A vestibular schwannoma, often called an acoustic neuroma/schwannoma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulo-cochlear nerve (8 th cranial nerve. This tumor arises from the Schwann cells responsible for the myelin sheath that helps keep peripheral nerves insulated. [1] Approximately, 3000 cases are diagnosed each year in the United States with a prevalence of about 1 in 100,000 worldwide. It comprises 5-10% of all intracranial neoplasms in adults. Incidence peaks in the fifth and sixth decades and both sexes are affected equally. Studies in Denmark published in 2004 show the incidence of 17.4/million. Most acoustic neuromas are diagnosed in patients between the ages of 30 and 60, and men and women appear to be affected equally. [2] The case illustrated here is a rare one of acoustic/vestibular schwannoma a surgical conditions, treated with Lycopodium, which produced improvement on both subjective and objective parameters.

The impact of expanding Canadian gas imports in the U.S. Midwest

International Nuclear Information System (INIS)

Parker, S.

2000-01-01

The new competitive natural gas market in the U. S. Midwest is surveyed from an interstate pipeline point of view, taking into account Canadian gas imports, increase in Rocky Mountain imports competing with Canadian imports, the flow dynamics in the Midwest market, supply basin production trends, the infrastructure improvements in local distribution companies, improvements in storage facilities, and the growing demand for natural gas-fired generation

From Contrapuntal Music to Polyphonic Novel: Aldous Huxley’s Point Counter Point

Directory of Open Access Journals (Sweden)

Mevlüde ZENGİN

2015-06-01

Full Text Available Taken at face value Point Counter Point (1928 written by Aldous Huxley seems to be a novel including many stories of various and sundry people and reflecting their points of view about the world in which they live and about the life they have been leading. However, it is this very quality of the novel that provides grounds for the study of the novel as a polyphonic one. The novel presents to its reader an aggregate of strikingly different characters and thus a broad spectrum of contemporary society. The characters in the novel are all characterized by and individualized with easily recognizable physical, intellectual, emotional, psychological and moral qualities. Each of them is well-contrived through their differences in social status, political views, wealth, etc. Thus, many different viewpoints, conflicting voices, contrasting insights and ideas are heard and seen synchronically in Point Counter Point, which makes it polyphonic. Polyphony is a musical motif referring to different notes and chords played at the same time to create a rhythm. It was first adopted by M. M. Bakhtin to analyze F. M. Dostoyevsky’s fiction. The aim of this study is firstly to elucidate, in Bakhtinian thought, polyphony and then dialogism and heteroglossia closely related to his concept of polyphony; and then to put the polyphonic qualities in Point Counter Point forth, studying the novel’s dialogism and heteroglot qualities

Flow area optimization in point to area or area to point flows

International Nuclear Information System (INIS)

Ghodoossi, Lotfollah; Egrican, Niluefer

2003-01-01

This paper deals with the constructal theory of generation of shape and structure in flow systems connecting one point to a finite size area. The flow direction may be either from the point to the area or the area to the point. The formulation of the problem remains the same if the flow direction is reversed. Two models are used in optimization of the point to area or area to point flow problem: cost minimization and revenue maximization. The cost minimization model enables one to predict the shape of the optimized flow areas, but the geometric sizes of the flow areas are not predictable. That is, as an example, if the area of flow is a rectangle with a fixed area size, optimization of the point to area or area to point flow problem by using the cost minimization model will only predict the height/length ratio of the rectangle not the height and length itself. By using the revenue maximization model in optimization of the flow problems, all optimized geometric aspects of the interested flow areas will be derived as well. The aim of this paper is to optimize the point to area or area to point flow problems in various elemental flow area shapes and various structures of the flow system (various combinations of elemental flow areas) by using the revenue maximization model. The elemental flow area shapes used in this paper are either rectangular or triangular. The forms of the flow area structure, made up of an assembly of optimized elemental flow areas to obtain bigger flow areas, are rectangle-in-rectangle, rectangle-in-triangle, triangle-in-triangle and triangle-in-rectangle. The global maximum revenue, revenue collected per unit flow area and the shape and sizes of each flow area structure have been derived in optimized conditions. The results for each flow area structure have been compared with the results of the other structures to determine the structure that provides better performance. The conclusion is that the rectangle-in-triangle flow area structure

Information resources and the correlation of response patterns between biological end points

Energy Technology Data Exchange (ETDEWEB)

Malling, H.V. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Wassom, J.S. [Oak Ridge National Laboratory, TN (United States)

1990-12-31

This paper focuses on the analysis of information for mutagenesis, a biological end point that is important in the overall process of assessing possible adverse health effects from chemical exposure. 17 refs.

Unidirectional reflectionless light propagation at exceptional points

Directory of Open Access Journals (Sweden)

Huang Yin

2017-05-01

Full Text Available In this paper, we provide a comprehensive review of unidirectional reflectionless light propagation in photonic devices at exceptional points (EPs. EPs, which are branch point singularities of the spectrum, associated with the coalescence of both eigenvalues and corresponding eigenstates, lead to interesting phenomena, such as level repulsion and crossing, bifurcation, chaos, and phase transitions in open quantum systems described by non-Hermitian Hamiltonians. Recently, it was shown that judiciously designed photonic synthetic matters could mimic the complex non-Hermitian Hamiltonians in quantum mechanics and realize unidirectional reflection at optical EPs. Unidirectional reflectionlessness is of great interest for optical invisibility. Achieving unidirectional reflectionless light propagation could also be potentially important for developing optical devices, such as optical network analyzers. Here, we discuss unidirectional reflectionlessness at EPs in both parity-time (PT-symmetric and non-PT-symmetric optical systems. We also provide an outlook on possible future directions in this field.

Professional SharePoint 2010 Development

CERN Document Server

Rizzo, Tom; Fried, Jeff

2010-01-01

Learn to leverage the features of the newest version of SharePoint, in this update to the bestseller. More than simply a portal, SharePoint is Microsoft's popular content management solution for building intranets and Web sites or hosting wikis and blogs. Offering broad coverage on all aspects of development for the SharePoint platform, this comprehensive book shows you exactly what SharePoint does, how to build solutions, and what features are accessible within SharePoint. Written by one of the most recognized names in SharePoint development, Professional SharePoint 2010 Development offers an

Immediate side effects of stereotactic radiotherapy and radiosurgery

International Nuclear Information System (INIS)

Werner-Wasik, Maria; Rudoler, Shari; Preston, Peter E.; Downes, Beverly M.; Andrews, David; Corn, Benjamin W.; Rosenstock, Jeffrey; Curran, Walter J.

1996-01-01

Purpose/Objective: Despite increased utilization of fractionated stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS), the incidence and nature of immediate side effects (ISE) associated with these treatment techniques is not well defined. Materials and Methods: Intracranial lesions in 78 adult patients were treated with SRT or SRS, using a dedicated linear accelerator. They comprised 13 gliomas, 2 ependymomas, 19 metastatic tumors, 15 meningiomas, 12 acoustic neuromas, 4 pituitary adenomas, 1 optic neuroma, 1 chondrosarcoma and 11 arteriovenous malformations (AVM). SRT was used in 51 and SRS in 27 patients. Mean target volume was 9.0 cc. Eleven patients received prior external beam radiation therapy within 2 months before SRT/SRS. Any side effects occurring during and up to two weeks after radiation course were defined as ISE and were graded as mild, moderate or severe. The incidence of ISE and the significance of their association with several pretreatment variables were analyzed. Results: Overall, (28(78)) (35%) patients experienced one or more ISE. Most of ISE (87%) were mild and consisted of nausea (5), dizziness/vertigo (5), seizures (7) and new persistent headaches (17). Two episodes of worsening neurological deficit and 2 of orbital pain were graded as moderate. Two patients experienced severe ISE, requiring hospitalization (1 seizure and 1 worsening neurological deficit). ISE in 5 cases prompted computerized tomography of the brain which revealed increased perilesional edema in 3 cases. The incidence of ISE by diagnosis was as follows: 46% ((6(13))) for gliomas, 50% ((6(12))) for acoustic neuromas, 36% ((4(11))) for AVM, 33% ((5(15))) for meningiomas and 21% ((4(19))) for metastases. Increasing dose to the margin and increasing maximum dose were associated with a higher incidence of ISE (p=0.02 and 0.005, respectively). Prior recent conventional external beam radiation therapy, target volume, number of isocenters, collimator size, dose

SIDELOADING – INGESTION OF LARGE POINT CLOUDS INTO THE APACHE SPARK BIG DATA ENGINE

Directory of Open Access Journals (Sweden)

J. Boehm

2016-06-01

Full Text Available In the geospatial domain we have now reached the point where data volumes we handle have clearly grown beyond the capacity of most desktop computers. This is particularly true in the area of point cloud processing. It is therefore naturally lucrative to explore established big data frameworks for big geospatial data. The very first hurdle is the import of geospatial data into big data frameworks, commonly referred to as data ingestion. Geospatial data is typically encoded in specialised binary file formats, which are not naturally supported by the existing big data frameworks. Instead such file formats are supported by software libraries that are restricted to single CPU execution. We present an approach that allows the use of existing point cloud file format libraries on the Apache Spark big data framework. We demonstrate the ingestion of large volumes of point cloud data into a compute cluster. The approach uses a map function to distribute the data ingestion across the nodes of a cluster. We test the capabilities of the proposed method to load billions of points into a commodity hardware compute cluster and we discuss the implications on scalability and performance. The performance is benchmarked against an existing native Apache Spark data import implementation.

The Lagrangian Points

Science.gov (United States)

Linton, J. Oliver

2017-01-01

There are five unique points in a star/planet system where a satellite can be placed whose orbital period is equal to that of the planet. Simple methods for calculating the positions of these points, or at least justifying their existence, are developed.

When is protein binding important?

Science.gov (United States)

Heuberger, Jules; Schmidt, Stephan; Derendorf, Hartmut

2013-09-01

The present paper is an ode to a classic citation by Benet and Hoener (2002. Clin Pharm Ther 71(3):115-121). The now classic paper had a huge impact on drug development and the way the issue of protein binding is perceived and interpreted. Although the authors very clearly pointed out the limitations and underlying assumptions for their delineations, these are too often overlooked and the classic paper's message is misinterpreted by broadening to cases that were not intended. Some members of the scientific community concluded from the paper that protein binding is not important. This was clearly not intended by the authors, as they finished their paper with a paragraph entitled: "When is protein binding important?" Misinterpretation of the underlying assumptions in the classic work can result in major pitfalls in drug development. Therefore, we revisit the topic of protein binding with the intention of clarifying when clinically relevant changes should be considered during drug development. Copyright © 2013 Wiley Periodicals, Inc.

Vibrational zero point energy for H-doped silicon

Science.gov (United States)

Karazhanov, S. Zh.; Ganchenkova, M.; Marstein, E. S.

2014-05-01

Most of the studies addressed to computations of hydrogen parameters in semiconductor systems, such as silicon, are performed at zero temperature T = 0 K and do not account for contribution of vibrational zero point energy (ZPE). For light weight atoms such as hydrogen (H), however, magnitude of this parameter might be not negligible. This Letter is devoted to clarify the importance of accounting the zero-point vibrations when analyzing hydrogen behavior in silicon and its effect on silicon electronic properties. For this, we estimate the ZPE for different locations and charge states of H in Si. We show that the main contribution to the ZPE is coming from vibrations along the Si-H bonds whereas contributions from other Si atoms apart from the direct Si-H bonds play no role. It is demonstrated that accounting the ZPE reduces the hydrogen formation energy by ˜0.17 eV meaning that neglecting ZPE at low temperatures one can underestimate hydrogen solubility by few orders of magnitude. In contrast, the effect of the ZPE on the ionization energy of H in Si is negligible. The results can have important implications for characterization of vibrational properties of Si by inelastic neutron scattering, as well as for theoretical estimations of H concentration in Si.

Design of Wireless Point of Sale Based on ZigBee Technology

Directory of Open Access Journals (Sweden)

Xiaoning Jiang

2014-02-01

Full Text Available With the rapid development of Point of Sale technology and modern communication technology, financial Point of Sale terminal system has been started from wired to wireless. Wireless payment technology can used where can’t rely on or even no cable network. As one of the most important technologies in the information era, Wireless Sensor Network has been widely used in banking business and other various modem business fields. This paper describes a kind of simple portable Point of Sale terminal based on the ZigBee wireless network 1, which is a low power, low cost, flexible, safe and reliable network. This Point of Sale system can be applied gas stations, liquefied petroleum gas stations and other complex sales environment, and it improves safety of gas station and personnel safety. Simple and user-friendly, this formula design and optimization method greatly improves efficiency and thus has much value for practical application.

The End of Points

Science.gov (United States)

Feldman, Jo

2018-01-01

Have teachers become too dependent on points? This article explores educators' dependency on their points systems, and the ways that points can distract teachers from really analyzing students' capabilities and achievements. Feldman argues that using a more subjective grading system can help illuminate crucial information about students and what…

Export and import provisions for nuclear materials and power plants, from the legal point of view

International Nuclear Information System (INIS)

Shapar, H.K.

1975-01-01

This paper provides a general review of the legal bases for and the administrative procedures involved in the export and import licensing of nuclear power reactors, fuels, and other nuclear materials by the United States. The basic statutory provisions and requirements are briefly described, and the requirement of an agreement for cooperation reviewed. The regulations of the Nuclear Regulatory Commission are covered in greater detail as they apply to the export and import of power reactors, nuclear fuels, source materials and byproduct materials. The intra-governmental procedures for review of an application for an export license are described in detail. Problems encountered in the administration of the law and regulations are described and the methods of resolving them are noted. The paper concludes with a brief account of three current topics, 1) the preparation of an environmental impact statement for export programs, 2) the situation with respect to the export licensing of component parts of reactors by the U.S. Department of Commerce, and 3) the shipment of plutonium by air. (orig.) [de

Effect of target color and scanning geometry on terrestrial LiDAR point-cloud noise and plane fitting

Science.gov (United States)

Bolkas, Dimitrios; Martinez, Aaron

2018-01-01

Point-cloud coordinate information derived from terrestrial Light Detection And Ranging (LiDAR) is important for several applications in surveying and civil engineering. Plane fitting and segmentation of target-surfaces is an important step in several applications such as in the monitoring of structures. Reliable parametric modeling and segmentation relies on the underlying quality of the point-cloud. Therefore, understanding how point-cloud errors affect fitting of planes and segmentation is important. Point-cloud intensity, which accompanies the point-cloud data, often goes hand-in-hand with point-cloud noise. This study uses industrial particle boards painted with eight different colors (black, white, grey, red, green, blue, brown, and yellow) and two different sheens (flat and semi-gloss) to explore how noise and plane residuals vary with scanning geometry (i.e., distance and incidence angle) and target-color. Results show that darker colors, such as black and brown, can produce point clouds that are several times noisier than bright targets, such as white. In addition, semi-gloss targets manage to reduce noise in dark targets by about 2-3 times. The study of plane residuals with scanning geometry reveals that, in many of the cases tested, residuals decrease with increasing incidence angles, which can assist in understanding the distribution of plane residuals in a dataset. Finally, a scheme is developed to derive survey guidelines based on the data collected in this experiment. Three examples demonstrate that users should consider instrument specification, required precision of plane residuals, required point-spacing, target-color, and target-sheen, when selecting scanning locations. Outcomes of this study can aid users to select appropriate instrumentation and improve planning of terrestrial LiDAR data-acquisition.

Multispectral Image Feature Points

Directory of Open Access Journals (Sweden)

Cristhian Aguilera

2012-09-01

Full Text Available This paper presents a novel feature point descriptor for the multispectral image case: Far-Infrared and Visible Spectrum images. It allows matching interest points on images of the same scene but acquired in different spectral bands. Initially, points of interest are detected on both images through a SIFT-like based scale space representation. Then, these points are characterized using an Edge Oriented Histogram (EOH descriptor. Finally, points of interest from multispectral images are matched by finding nearest couples using the information from the descriptor. The provided experimental results and comparisons with similar methods show both the validity of the proposed approach as well as the improvements it offers with respect to the current state-of-the-art.

10 points about buying C.I.S

International Nuclear Information System (INIS)

Anon.

1993-01-01

On October 16, 1992, the U.S. Department of Commerce (DOC) settled the antidumping case against the CIS republics by imposing price and volume quotas on CIS uranium imported into the United States. Bound by a suspension agreement, each of the six uranium-producing CIS republics is responsible for restricting the flow of imports to the US-either directly or indirectly. (As the NUKEM Market Report went to press, the Ukraine government notified the DOC of its intent not to terminate the suspension agreement.) This action is to prevent undercutting price levels in the US domestic uranium markets. What follows are ten points about everything you should know about importing uranium from the uranium-producing CIS republics- Kazakhstan, Kyrgyzstan, Russian Federation, Tajikistan, Ukraine and Uzbekistan. Newcomers to the CIS scene should follow this simple roadmap and be aware of the issues they face as importers in terms of Commerce/Customs requirements and documentation and where to get them, when to buy the material and how to transport it, how to deal effectively with CIS exporters, and how to avoid unnecessary complications when buying CIS

The Closest Point Method and Multigrid Solvers for Elliptic Equations on Surfaces

KAUST Repository

Chen, Yujia

2015-01-01

© 2015 Society for Industrial and Applied Mathematics. Elliptic partial differential equations are important from both application and analysis points of view. In this paper we apply the closest point method to solve elliptic equations on general curved surfaces. Based on the closest point representation of the underlying surface, we formulate an embedding equation for the surface elliptic problem, then discretize it using standard finite differences and interpolation schemes on banded but uniform Cartesian grids. We prove the convergence of the difference scheme for the Poisson\\'s equation on a smooth closed curve. In order to solve the resulting large sparse linear systems, we propose a specific geometric multigrid method in the setting of the closest point method. Convergence studies in both the accuracy of the difference scheme and the speed of the multigrid algorithm show that our approaches are effective.

Fixed point iterations for strictly hemi-contractive maps in uniformly smooth Banach spaces

International Nuclear Information System (INIS)

Chidume, C.E.; Osilike, M.O.

1993-05-01

It is proved that the Mann iteration process converges strongly to the fixed point of a strictly hemi-contractive map in real uniformly smooth Banach spaces. The class of strictly hemi-contractive maps includes all strictly pseudo-contractive maps with nonempty fixed point sets. A related result deals with the Ishikawa iteration scheme when the mapping is Lipschitzian and strictly hemi-contractive. Our theorems generalize important known results. (author). 29 refs

Recalcitrant vulvodynia A clinicopathological study | Sonnedecker ...

African Journals Online (AJOL)

Single patients had the following specific conditions: lichen planus, lichen sclerosus, mature neuroma and chronic candidiasis. The study shows that vulvodynia is a multifactorial problem for which management strategies have evolved over the course of time. Although interferon-a-2b offers much prom.ise for the treatment ...

Measured emotional intelligence ability and grade point average in nursing students.

Science.gov (United States)

Codier, Estelle; Odell, Ellen

2014-04-01

For most schools of nursing, grade point average is the most important criteria for admission to nursing school and constitutes the main indicator of success throughout the nursing program. In the general research literature, the relationship between traditional measures of academic success, such as grade point average and postgraduation job performance is not well established. In both the general population and among practicing nurses, measured emotional intelligence ability correlates with both performance and other important professional indicators postgraduation. Little research exists comparing traditional measures of intelligence with measured emotional intelligence prior to graduation, and none in the student nurse population. This exploratory, descriptive, quantitative study was undertaken to explore the relationship between measured emotional intelligence ability and grade point average of first year nursing students. The study took place at a school of nursing at a university in the south central region of the United States. Participants included 72 undergraduate student nurse volunteers. Emotional intelligence was measured using the Mayer-Salovey-Caruso Emotional Intelligence Test, version 2, an instrument for quantifying emotional intelligence ability. Pre-admission grade point average was reported by the school records department. Total emotional intelligence (r=.24) scores and one subscore, experiential emotional intelligence(r=.25) correlated significantly (>.05) with grade point average. This exploratory, descriptive study provided evidence for some relationship between GPA and measured emotional intelligence ability, but also demonstrated lower than average range scores in several emotional intelligence scores. The relationship between pre-graduation measures of success and level of performance postgraduation deserves further exploration. The findings of this study suggest that research on the relationship between traditional and nontraditional

Professional SharePoint 2010 Development

CERN Document Server

Rizzo, Tom; Fried, Jeff; Swider, Paul J; Hillier, Scot; Schaefer, Kenneth

2012-01-01

Updated guidance on how to take advantage of the newest features of SharePoint programmability More than simply a portal, SharePoint is Microsoft's popular content management solution for building intranets and websites or hosting wikis and blogs. Offering broad coverage on all aspects of development for the SharePoint platform, this comprehensive book shows you exactly what SharePoint does, how to build solutions, and what features are accessible within SharePoint. Written by a team of SharePoint experts, this new edition offers an extensive selection of field-tested best practices that shows

SharePoint 2010 For Dummies

CERN Document Server

Williams, Vanessa L

2012-01-01

Here's the bestselling guide on SharePoint 2010, updated to cover Office 365 SharePoint Portal Server is an essential part of the enterprise infrastructure for many businesses. The Office 365 version includes significantly enhanced cloud capabilities. This second edition of the bestselling guide to SharePoint covers getting a SharePoint site up and running, branded, populated with content, and more. It explains ongoing site management and offers plenty of advice for administrators who want to leverage SharePoint and Office 365 in various ways.Many businesses today rely on SharePoint Portal Ser

Clinical Experience With Radiation Therapy in the Management of Neurofibromatosis-Associated Central Nervous System Tumors

International Nuclear Information System (INIS)

Wentworth, Stacy; Pinn, Melva; Bourland, J. Daniel; Guzman, Allan F. de; Ekstrand, Kenneth; Ellis, Thomas L.; Glazier, Steven S.; McMullen, Kevin P.; Munley, Michael; Stieber, Volker W.; Tatter, Stephen B.; Shaw, Edward G.

2009-01-01

Purpose: Patients with neurofibromatosis (NF) develop tumors of the central nervous system (CNS). Radiation therapy (RT) is used to treat these lesions. To better define the efficacy of RT in these patients, we reviewed our 20-year experience. Methods and Materials: Eighteen patients with NF with CNS tumors were treated from 1986 to 2007. Median follow-up was 48 months. Progression was defined as growth or recurrence of an irradiated tumor on serial imaging. Progression-free survival (PFS) was measured from the date of RT completion to the date of last follow-up imaging study. Actuarial rates of overall survival (OS) and PFS were calculated according to the Kaplan-Meier method. Results: Eighty-two tumors in 18 patients were irradiated, with an average of five tumors/patient. Median age at treatment was 25 years (range, 4.3-64 years). Tumor types included acoustic neuroma (16%), ependymoma (6%), low-grade glioma (11%), meningioma (60%), and schwanomma/neurofibroma (7%). The most common indication for treatment was growth on serial imaging. Most patients (67%) received stereotactic radiosurgery (median dose, 1,200 cGy; range, 1,000-2,400 cGy). The OS rate at 5 years was 94%. Five-year PFS rates were 75% (acoustic neuroma), 100% (ependymoma), 75% (low-grade glioma), 86% (meningioma), and 100% (schwanomma/neurofibroma). Thirteen acoustic neuromas had a local control rate of 94% with a 50% hearing preservation rate. Conclusions: RT provided local control, OS, and PFS rates similar to or better than published data for tumors in non-NF patients. Radiation therapy should be considered in NF patients with imaging progression of CNS tumors

Theory of finite-entanglement scaling at one-dimensional quantum critical points.

Science.gov (United States)

Pollmann, Frank; Mukerjee, Subroto; Turner, Ari M; Moore, Joel E

2009-06-26

Studies of entanglement in many-particle systems suggest that most quantum critical ground states have infinitely more entanglement than noncritical states. Standard algorithms for one-dimensional systems construct model states with limited entanglement, which are a worse approximation to quantum critical states than to others. We give a quantitative theory of previously observed scaling behavior resulting from finite entanglement at quantum criticality. Finite-entanglement scaling in one-dimensional systems is governed not by the scaling dimension of an operator but by the "central charge" of the critical point. An important ingredient is the universal distribution of density-matrix eigenvalues at a critical point [P. Calabrese and A. Lefevre, Phys. Rev. A 78, 032329 (2008)10.1103/PhysRevA.78.032329]. The parameter-free theory is checked against numerical scaling at several quantum critical points.

Throughput analysis of point-to-multi-point hybric FSO/RF network

KAUST Repository

Rakia, Tamer; Gebali, Fayez; Yang, Hong-Chuan; Alouini, Mohamed-Slim

2017-01-01

This paper presents and analyzes a point-to-multi-point (P2MP) network that uses a number of free-space optical (FSO) links for data transmission from the central node to the different remote nodes. A common backup radio-frequency (RF) link is used

Practical guidebook of the petroleum regulation (import-distribution); Guide pratique de la reglementation petroliere (importation-distribution)

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-02-01

This yearly guidebook is issued at the beginning of each year. It brings together, with some relevant comments, the overall regulation related to the import and distribution of petroleum products in France. It includes some models of declaration files, the organisation of the French general direction of energy and raw materials (DGEMP) and of the direction of customs. It includes the most recent texts and is intended for jurists and non-jurists petroleum operators. It comprises three parts dealing with: 1 - general regulation (import rules, product characteristics, stockpiles, creation and extension of depots, regulation of sale points, pricing regulation and competition, advertising in the domain of energy); custom and fiscal regulation (custom rights, taxes, preferential fiscal regimes, depot regulations, powers of attorney, tax exemption, return to stocks); statistical declarations (declarations for the administration and for the French professional committee of petroleum (CPDP)). (J.S.)

The timing of control signals underlying fast point-to-point arm movements.

Science.gov (United States)

Ghafouri, M; Feldman, A G

2001-04-01

It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

The goal of ape pointing.

Science.gov (United States)

Halina, Marta; Liebal, Katja; Tomasello, Michael

2018-01-01

Captive great apes regularly use pointing gestures in their interactions with humans. However, the precise function of this gesture is unknown. One possibility is that apes use pointing primarily to direct attention (as in "please look at that"); another is that they point mainly as an action request (such as "can you give that to me?"). We investigated these two possibilities here by examining how the looking behavior of recipients affects pointing in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). Upon pointing to food, subjects were faced with a recipient who either looked at the indicated object (successful-look) or failed to look at the indicated object (failed-look). We predicted that, if apes point primarily to direct attention, subjects would spend more time pointing in the failed-look condition because the goal of their gesture had not been met. Alternatively, we expected that, if apes point primarily to request an object, subjects would not differ in their pointing behavior between the successful-look and failed-look conditions because these conditions differed only in the looking behavior of the recipient. We found that subjects did differ in their pointing behavior across the successful-look and failed-look conditions, but contrary to our prediction subjects spent more time pointing in the successful-look condition. These results suggest that apes are sensitive to the attentional states of gestural recipients, but their adjustments are aimed at multiple goals. We also found a greater number of individuals with a strong right-hand than left-hand preference for pointing.

Critical Point Cancellation in 3D Vector Fields: Robustness and Discussion.

Science.gov (United States)

Skraba, Primoz; Rosen, Paul; Wang, Bei; Chen, Guoning; Bhatia, Harsh; Pascucci, Valerio

2016-02-29

Vector field topology has been successfully applied to represent the structure of steady vector fields. Critical points, one of the essential components of vector field topology, play an important role in describing the complexity of the extracted structure. Simplifying vector fields via critical point cancellation has practical merit for interpreting the behaviors of complex vector fields such as turbulence. However, there is no effective technique that allows direct cancellation of critical points in 3D. This work fills this gap and introduces the first framework to directly cancel pairs or groups of 3D critical points in a hierarchical manner with a guaranteed minimum amount of perturbation based on their robustness, a quantitative measure of their stability. In addition, our framework does not require the extraction of the entire 3D topology, which contains non-trivial separation structures, and thus is computationally effective. Furthermore, our algorithm can remove critical points in any subregion of the domain whose degree is zero and handle complex boundary configurations, making it capable of addressing challenging scenarios that may not be resolved otherwise. We apply our method to synthetic and simulation datasets to demonstrate its effectiveness.

Automatic markerless registration of point clouds with semantic-keypoint-based 4-points congruent sets

Science.gov (United States)

Ge, Xuming

2017-08-01

The coarse registration of point clouds from urban building scenes has become a key topic in applications of terrestrial laser scanning technology. Sampling-based algorithms in the random sample consensus (RANSAC) model have emerged as mainstream solutions to address coarse registration problems. In this paper, we propose a novel combined solution to automatically align two markerless point clouds from building scenes. Firstly, the method segments non-ground points from ground points. Secondly, the proposed method detects feature points from each cross section and then obtains semantic keypoints by connecting feature points with specific rules. Finally, the detected semantic keypoints from two point clouds act as inputs to a modified 4PCS algorithm. Examples are presented and the results compared with those of K-4PCS to demonstrate the main contributions of the proposed method, which are the extension of the original 4PCS to handle heavy datasets and the use of semantic keypoints to improve K-4PCS in relation to registration accuracy and computational efficiency.

The importance of protozoan bacterivory in a subtropical environment (Lobo-Broa Reservoir, SP, Brazil

Directory of Open Access Journals (Sweden)

AS Mansano

Full Text Available This study evaluated the importance of heterotrophic nanoflagellates (HNF and ciliates bacterivory in a mesotrophic subtropical environment (Lobo-Broa Reservoir, Brazil by the quantification of their ingestion rates. The in situ experiments using fluorescently labelled bacteria (FLB were carried out bimonthly over one year (three surveys in the dry season and three in the rainy one at the sub-surface of two sampling points that have different trophic degrees. The ingestion rates for both ciliates and HNF were higher in the meso-eutrophic region (point 2 due to the higher water temperatures, which accelerate the metabolism of protozoans and the higher bacteria densities. Concerning total protozoan bacterivory, the HNF had the greatest grazing impact on bacterial community, especially the HNF <5µm. The data showed that HNF grazing, in addition to regulating the bacteria abundance, also induced changes to the bacterial community structure, such as increasing size and numbers of bacterial filaments. The ciliates were also important to the system bacterivory, especially in point 2, where there were high densities and ingestion rates. The protozoan bottom-up control was more important in the dry season and the top-down control was more important in the rainy season, so, these two forces are equally important to the bacterial abundance regulation in this reservoir in an annual basis.

Accelerated successive substitution schemes for bubble-point and dew-point calculations

Energy Technology Data Exchange (ETDEWEB)

Peng, D.-Y. (Univ. of Saskatchewan, Saskatoon, SK (Canada))

1991-08-01

Phase equilibrium calculations form an important part of the process design operations in the hydrocarbon and petroleum industry. The accelerated successive substitution (SS) algorithms developed by Mehra et al. (1983) for flash calculations have been extended to the prediction of saturation points. A transformation matrix which is used to calculate the acceleration parameter has been rewritten in a form that is applicable at the saturation conditions. Simple equations for estimating the initial values and recursive formulae according to which the iterates can be updated are presented. The proposed schemes were compared with the conventional SS method and a multivariate Newton's method. The comparison suggests that the accelerated SS schemes are more tolerant of poor initial values and sometimes more efficient than Newton's method. The features of the acceleration schemes and those of the empirical equations developed in this study are illustrated using three hydrocarbon mixtures: a 5-component mixture of n-alkanes, a typical natural gas system, and a volatile oil. 19 refs., 6 figs., 6 tabs.

Point Cluster Analysis Using a 3D Voronoi Diagram with Applications in Point Cloud Segmentation

Directory of Open Access Journals (Sweden)

Shen Ying

2015-08-01

Full Text Available Three-dimensional (3D point analysis and visualization is one of the most effective methods of point cluster detection and segmentation in geospatial datasets. However, serious scattering and clotting characteristics interfere with the visual detection of 3D point clusters. To overcome this problem, this study proposes the use of 3D Voronoi diagrams to analyze and visualize 3D points instead of the original data item. The proposed algorithm computes the cluster of 3D points by applying a set of 3D Voronoi cells to describe and quantify 3D points. The decompositions of point cloud of 3D models are guided by the 3D Voronoi cell parameters. The parameter values are mapped from the Voronoi cells to 3D points to show the spatial pattern and relationships; thus, a 3D point cluster pattern can be highlighted and easily recognized. To capture different cluster patterns, continuous progressive clusters and segmentations are tested. The 3D spatial relationship is shown to facilitate cluster detection. Furthermore, the generated segmentations of real 3D data cases are exploited to demonstrate the feasibility of our approach in detecting different spatial clusters for continuous point cloud segmentation.

SharePoint 2010 Field Guide

CERN Document Server

Mann, Steven; Gazmuri, Pablo; Caravajal, Steve; Wheeler, Christina

2012-01-01

Hands-on solutions for common SharePoint 2010 challenges Aimed at the more than 100 million licensed SharePoint 2010 users, this indispensable field guide addresses an abundance of common SharePoint 2010 problems and offers proven solutions. A team of authors encourages you to customize SharePoint beyond the out-of-the-box functionality so that you can build more complex solutions to these challenges. You?ll discover intricate details and specific full-scale solutions that you can then implement to your own SharePoint 2010 solutions.Tackles a variety of SharePoint 2010 problems ranging from si

Professional SharePoint 2010 Administration

CERN Document Server

Klindt, Todd; Caravajal, Steve

2010-01-01

Thorough coverage of the improvements and changes to SharePoint 2010. SharePoint 2010 boasts a variety of incredible new features that will challenge even the most experienced administrator who is upgrading from SharePoint 2007. Written by a team of SharePoint experts, this book places a takes aim at showing you how to make these new features work right for you. Offering an in-depth look at SharePoint 2010, the authors focus on how SharePoint functionality has changed from its earliest version to its newest, and they provide you with detailed coverage of all the new features and capabilities.:

Professional SharePoint 2013 administration

CERN Document Server

Young, Shane; Klindt, Todd

2013-01-01

SharePoint admin author gurus return to prepare you for working with the new features of SharePoint 2013! The new iteration of SharePoint boasts exciting new features. However, any new version also comes with its fair share of challenges and that's where this book comes in. The team of SharePoint admin gurus returns to presents a fully updated resource that prepares you for making all the new SharePoint 2013 features work right. They cover all of the administration components of SharePoint 2013 in detail, and present a clear understanding of how they affect the role of the adminis

Determination of melting point of mixed-oxide fuel irradiated in a fast breeder reactor

International Nuclear Information System (INIS)

Tachibana, Toshimichi

1985-01-01

The melting point of fuel is important to set its in-reactor maximum temperature in fuel design. The fuel melting point measuring methods are broadly the filament method and the capsule sealing method. The only instance of measuring the melting point of irradiated mixed oxide (U, Pu)O 2 fuel by the filament method is by GE in the United States. The capsule sealing method, while the excellent means, is difficult in weld sealing the irradiated fuel in a capsule within the cell. In the fast reactor development program, the remotely operated melting point measuring apparatus in capsule sealing the mixed (U, Pu)O 2 fuel irradiated in the experimental FBR Joyo was set in the cell and the melting point was measured, for the first time in the world. (Mori, K.)

Visualizing Robustness of Critical Points for 2D Time-Varying Vector Fields

KAUST Repository

Wang, B.

2013-06-01

Analyzing critical points and their temporal evolutions plays a crucial role in understanding the behavior of vector fields. A key challenge is to quantify the stability of critical points: more stable points may represent more important phenomena or vice versa. The topological notion of robustness is a tool which allows us to quantify rigorously the stability of each critical point. Intuitively, the robustness of a critical point is the minimum amount of perturbation necessary to cancel it within a local neighborhood, measured under an appropriate metric. In this paper, we introduce a new analysis and visualization framework which enables interactive exploration of robustness of critical points for both stationary and time-varying 2D vector fields. This framework allows the end-users, for the first time, to investigate how the stability of a critical point evolves over time. We show that this depends heavily on the global properties of the vector field and that structural changes can correspond to interesting behavior. We demonstrate the practicality of our theories and techniques on several datasets involving combustion and oceanic eddy simulations and obtain some key insights regarding their stable and unstable features. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

Visualizing Robustness of Critical Points for 2D Time-Varying Vector Fields

KAUST Repository

Wang, B.; Rosen, P.; Skraba, P.; Bhatia, H.; Pascucci, V.

2013-01-01

Analyzing critical points and their temporal evolutions plays a crucial role in understanding the behavior of vector fields. A key challenge is to quantify the stability of critical points: more stable points may represent more important phenomena or vice versa. The topological notion of robustness is a tool which allows us to quantify rigorously the stability of each critical point. Intuitively, the robustness of a critical point is the minimum amount of perturbation necessary to cancel it within a local neighborhood, measured under an appropriate metric. In this paper, we introduce a new analysis and visualization framework which enables interactive exploration of robustness of critical points for both stationary and time-varying 2D vector fields. This framework allows the end-users, for the first time, to investigate how the stability of a critical point evolves over time. We show that this depends heavily on the global properties of the vector field and that structural changes can correspond to interesting behavior. We demonstrate the practicality of our theories and techniques on several datasets involving combustion and oceanic eddy simulations and obtain some key insights regarding their stable and unstable features. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

The cislunar low-thrust trajectories via the libration point

Science.gov (United States)

Qu, Qingyu; Xu, Ming; Peng, Kun

2017-05-01

The low-thrust propulsion will be one of the most important propulsion in the future due to its large specific impulse. Different from traditional low-thrust trajectories (LTTs) yielded by some optimization algorithms, the gradient-based design methodology is investigated for LTTs in this paper with the help of invariant manifolds of LL1 point and Halo orbit near the LL1 point. Their deformations under solar gravitational perturbation are also presented to design LTTs in the restricted four-body model. The perturbed manifolds of LL1 point and its Halo orbit serve as the free-flight phase to reduce the fuel consumptions as much as possible. An open-loop control law is proposed, which is used to guide the spacecraft escaping from Earth or captured by Moon. By using a two-dimensional search strategy, the ON/OFF time of the low-thrust engine in the Earth-escaping and Moon-captured phases can be obtained. The numerical implementations show that the LTTs achieved in this paper are consistent with the one adopted by the SMART-1 mission.

Distribution majorization of corner points by reinforcement learning for moving object detection

Science.gov (United States)

Wu, Hao; Yu, Hao; Zhou, Dongxiang; Cheng, Yongqiang

2018-04-01

Corner points play an important role in moving object detection, especially in the case of free-moving camera. Corner points provide more accurate information than other pixels and reduce the computation which is unnecessary. Previous works only use intensity information to locate the corner points, however, the information that former and the last frames provided also can be used. We utilize the information to focus on more valuable area and ignore the invaluable area. The proposed algorithm is based on reinforcement learning, which regards the detection of corner points as a Markov process. In the Markov model, the video to be detected is regarded as environment, the selections of blocks for one corner point are regarded as actions and the performance of detection is regarded as state. Corner points are assigned to be the blocks which are seperated from original whole image. Experimentally, we select a conventional method which uses marching and Random Sample Consensus algorithm to obtain objects as the main framework and utilize our algorithm to improve the result. The comparison between the conventional method and the same one with our algorithm show that our algorithm reduce 70% of the false detection.

I See Your Point: Infants under 12 Months Understand that Pointing Is Communicative

Science.gov (United States)

Krehm, Madelaine; Onishi, Kristine H.; Vouloumanos, Athena

2014-01-01

Do young infants understand that pointing gestures allow the pointer to change the information state of a recipient? We used a third-party experimental scenario to examine whether 9- and 11-month-olds understand that a pointer's pointing gesture can inform a recipient about a target object. When the pointer pointed to a target, infants…

Towards Automatic Testing of Reference Point Based Interactive Methods

OpenAIRE

Ojalehto, Vesa; Podkopaev, Dmitry; Miettinen, Kaisa

2016-01-01

In order to understand strengths and weaknesses of optimization algorithms, it is important to have access to different types of test problems, well defined performance indicators and analysis tools. Such tools are widely available for testing evolutionary multiobjective optimization algorithms. To our knowledge, there do not exist tools for analyzing the performance of interactive multiobjective optimization methods based on the reference point approach to communicating ...

Applying importance-performance analysis to evaluate banking service quality

Directory of Open Access Journals (Sweden)

André Luís Policani Freitas

2012-11-01

Full Text Available In an increasingly competitive market, the identification of the most important aspects and the measurement of service quality as perceived by the customers are important actions taken by organizations which seek the competitive advantage. In particular, this scenario is typical of Brazilian banking sector. In this context, this article presents an exploratory case study in which the Importance-Performance Analysis (IPA was used to identify the strong and the weak points related to services provided by a bank. In order to check the reliability of the questionnaire, Cronbach's alpha and correlation analyses were used. The results are presented and some actions have been defined in order to improve the quality of services.

Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

Science.gov (United States)

Othman, Ahmed M.; El-arini, Mahdi M. M.; Ghitas, Ahmed; Fathy, Ahmed

2012-12-01

In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

Bubble-point and dew-point equation for binary refrigerant mixture R22-R142b

Energy Technology Data Exchange (ETDEWEB)

Liancheng Tan; Zhongyou Zhao; Yonghong Duan (Xi' an Jiaotong Univ., Xi' an (China). Dept. of Power Machinery Engineering)

1992-01-01

A bubble-point and dew-point equation (in terms either of temperature or of pressure is suggested for the refrigerant mixture R22-R142b), which is regarded as one of the alternatives to R12. This equation has been examined with experimental data. A modified Rackett equation for the calculation of the bubble-point volume is also proposed. Compared with the experimental data, the rms errors in the calculated values of the bubble-point temperature, the dew-point temperature, and the bubble-point volume are 1.093%, 0.947%, and 1.120%, respectively. The calculation covers a wide range of temperatures and pressures, even near the critical point. It is shown how the equations are extrapolated to calculate other binary refrigerant mixtures. (author)

Modified mean generation time parameter in the neutron point kinetics equations

Energy Technology Data Exchange (ETDEWEB)

Diniz, Rodrigo C.; Gonçalves, Alessandro C.; Rosa, Felipe S.S., E-mail: alessandro@nuclear.ufrj.br, E-mail: frosa@if.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

This paper proposes an approximation for the modified point kinetics equations proposed by NUNES et. al, 2015, through the adjustment of a kinetic parameter. This approximation consists of analyzing the terms of the modified point kinetics equations in order to identify the least important ones for the solution, resulting in a modification of the mean generation time parameter that incorporates all influences of the additional terms of the modified kinetics. This approximation is applied on the inverse kinetics, to compare the results with the inverse kinetics from the modified kinetics in order to validate the proposed model. (author)

Modified mean generation time parameter in the neutron point kinetics equations

International Nuclear Information System (INIS)

Diniz, Rodrigo C.; Gonçalves, Alessandro C.; Rosa, Felipe S.S.

2017-01-01

This paper proposes an approximation for the modified point kinetics equations proposed by NUNES et. al, 2015, through the adjustment of a kinetic parameter. This approximation consists of analyzing the terms of the modified point kinetics equations in order to identify the least important ones for the solution, resulting in a modification of the mean generation time parameter that incorporates all influences of the additional terms of the modified kinetics. This approximation is applied on the inverse kinetics, to compare the results with the inverse kinetics from the modified kinetics in order to validate the proposed model. (author)

AN IMPROVEMENT ON GEOMETRY-BASED METHODS FOR GENERATION OF NETWORK PATHS FROM POINTS

Directory of Open Access Journals (Sweden)

Z. Akbari

2014-10-01

Full Text Available Determining network path is important for different purposes such as determination of road traffic, the average speed of vehicles, and other network analysis. One of the required input data is information about network path. Nevertheless, the data collected by the positioning systems often lead to the discrete points. Conversion of these points to the network path have become one of the challenges which different researchers, presents many ways for solving it. This study aims at investigating geometry-based methods to estimate the network paths from the obtained points and improve an existing point to curve method. To this end, some geometry-based methods have been studied and an improved method has been proposed by applying conditions on the best method after describing and illustrating weaknesses of them.

Implante de tubo de silicone com e sem colágeno na regeneração de nervos em eqüinos Implant of silicone tube with or without collagen in nerve regeneration of horses

Directory of Open Access Journals (Sweden)

Nádia Delistoianov

2008-09-01

silicone conduz à regeneração de NUs e NTs de eqüinos sem formação de neuromas e que a adição de colágeno promove aumento do número de fibras mielinizadas.Surgical nerve repair in humans, dogs and laboratory animals is widely utilized for important clinical and experimental purposes. However, in horses there is scarce information. Neuroma and excessive conjunctive proliferation are reported. The aim of the present study was to add information about the repair process utilizing implant of silicone tubes with or without collagen in nerve regeneration of horses. Eight horses were allocated in two groups: GI-13 weeks and GII-26 weeks of observation. A complete section of the ulnar nerves (UNs and of the lateral cutaneous branch of the 17th thoracic nerves (TNs, bilaterally, was followed by repair with silicone tubes alternately filled with (STC or without collagen (ST, with a 5mm gap between stumps. Clinical evaluation was performed weekly, by cutaneous sensitivity testing of the region innervated by the respective operated nerves and physical examination of the thoracic limbs. No alterations were found in the locomotor apparatus. The first positive reactions to the cutaneous test occurred at the 9th week post-surgery. At the end of the observation period it was verified, grossly, that the nerves were involved by conjunctive tissue and the lumen of the tube was filled by a whitish tissue, in a cylindrical shape. The ends nerves were interconnected. Microscopically, myelinated axons and Schwann cells were present in the gap between the stumps. In the GII the number of myelinated fibers was greater. The distal nerve showed remyelination process. There was no presence of neuroma and the inflammatory process was limited to the perineural areas. It was concluded that the implant of silicone tubes results in regeneration of UNs and TNs of horses without formation of neuromas and that de addition of collagen promotes an increase in the number of myelinated fibers.

Maximum power point tracker based on fuzzy logic

International Nuclear Information System (INIS)

Daoud, A.; Midoun, A.

2006-01-01

The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

Imaging study on acupuncture points

Science.gov (United States)

Yan, X. H.; Zhang, X. Y.; Liu, C. L.; Dang, R. S.; Ando, M.; Sugiyama, H.; Chen, H. S.; Ding, G. H.

2009-09-01

The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

Imaging study on acupuncture points

International Nuclear Information System (INIS)

Yan, X H; Zhang, X Y; Liu, C L; Dang, R S; Ando, M; Sugiyama, H; Chen, H S; Ding, G H

2009-01-01

The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

Magic Pointing for Eyewear Computers

DEFF Research Database (Denmark)

Jalaliniya, Shahram; Mardanbegi, Diako; Pederson, Thomas

2015-01-01

In this paper, we propose a combination of head and eye movements for touchlessly controlling the "mouse pointer" on eyewear devices, exploiting the speed of eye pointing and accuracy of head pointing. The method is a wearable computer-targeted variation of the original MAGIC pointing approach...... which combined gaze tracking with a classical mouse device. The result of our experiment shows that the combination of eye and head movements is faster than head pointing for far targets and more accurate than eye pointing....

Prediction of the Flash Point of Binary and Ternary Straight-Chain Alkane Mixtures

Directory of Open Access Journals (Sweden)

X. Li

2014-01-01

Full Text Available The flash point is an important physical property used to estimate the fire hazard of a flammable liquid. To avoid the occurrence of fire or explosion, many models are used to predict the flash point; however, these models are complex, and the calculation process is cumbersome. For pure flammable substances, the research for predicting the flash point is systematic and comprehensive. For multicomponent mixtures, especially a hydrocarbon mixture, the current research is insufficient to predict the flash point. In this study, a model was developed to predict the flash point of straight-chain alkane mixtures using a simple calculation process. The pressure, activity coefficient, and other associated physicochemical parameters are not required for the calculation in the proposed model. A series of flash points of binary and ternary mixtures of straight-chain alkanes were determined. The results of the model present consistent experimental results with an average absolute deviation for the binary mixtures of 0.7% or lower and an average absolute deviation for the ternary mixtures of 1.03% or lower.

Identifying influential data points in hydrological model calibration and their impact on streamflow predictions

Science.gov (United States)

Wright, David; Thyer, Mark; Westra, Seth

2015-04-01

Highly influential data points are those that have a disproportionately large impact on model performance, parameters and predictions. However, in current hydrological modelling practice the relative influence of individual data points on hydrological model calibration is not commonly evaluated. This presentation illustrates and evaluates several influence diagnostics tools that hydrological modellers can use to assess the relative influence of data. The feasibility and importance of including influence detection diagnostics as a standard tool in hydrological model calibration is discussed. Two classes of influence diagnostics are evaluated: (1) computationally demanding numerical "case deletion" diagnostics; and (2) computationally efficient analytical diagnostics, based on Cook's distance. These diagnostics are compared against hydrologically orientated diagnostics that describe changes in the model parameters (measured through the Mahalanobis distance), performance (objective function displacement) and predictions (mean and maximum streamflow). These influence diagnostics are applied to two case studies: a stage/discharge rating curve model, and a conceptual rainfall-runoff model (GR4J). Removing a single data point from the calibration resulted in differences to mean flow predictions of up to 6% for the rating curve model, and differences to mean and maximum flow predictions of up to 10% and 17%, respectively, for the hydrological model. When using the Nash-Sutcliffe efficiency in calibration, the computationally cheaper Cook's distance metrics produce similar results to the case-deletion metrics at a fraction of the computational cost. However, Cooks distance is adapted from linear regression with inherit assumptions on the data and is therefore less flexible than case deletion. Influential point detection diagnostics show great potential to improve current hydrological modelling practices by identifying highly influential data points. The findings of this

On the point-source approximation of earthquake dynamics

Directory of Open Access Journals (Sweden)

Andrea Bizzarri

2014-06-01

Full Text Available The focus on the present study is on the point-source approximation of a seismic source. First, we compare the synthetic motions on the free surface resulting from different analytical evolutions of the seismic source (the Gabor signal (G, the Bouchon ramp (B, the Cotton and Campillo ramp (CC, the Yoffe function (Y and the Liu and Archuleta function (LA. Our numerical experiments indicate that the CC and the Y functions produce synthetics with larger oscillations and correspondingly they have a higher frequency content. Moreover, the CC and the Y functions tend to produce higher peaks in the ground velocity (roughly of a factor of two. We have also found that the falloff at high frequencies is quite different: it roughly follows ω−2 in the case of G and LA functions, it decays more faster than ω−2 for the B function, while it is slow than ω−1 for both the CC and the Y solutions. Then we perform a comparison of seismic waves resulting from 3-D extended ruptures (both supershear and subshear obeying to different governing laws against those from a single point-source having the same features. It is shown that the point-source models tend to overestimate the ground motions and that they completely miss the Mach fronts emerging from the supershear transition process. When we compare the extended fault solutions against a multiple point-sources model the agreement becomes more significant, although relevant discrepancies still persist. Our results confirm that, and more importantly quantify how, the point-source approximation is unable to adequately describe the radiation emitted during a real world earthquake, even in the most idealized case of planar fault with homogeneous properties and embedded in a homogeneous, perfectly elastic medium.

The open superstring 6-point amplitude with manifest symmetries

International Nuclear Information System (INIS)

Barreiro, Luiz Antonio; Medina, Ricardo; Stieberger, Stephan

2011-01-01

Full text: The general tree level amplitude for massless bosons states of open superstrings has been known for a long time ago. It is clear how to obtain this general formula using vertex operators in the Ramond-Neveu-Schwarz formalism. From the beginning of the eighties the explicit expression for this formula has been known in the case of 3 and 4-point amplitudes. In that decade an attempt (with partial success) was done, by Kitazawa, to obtain the corresponding 5-point amplitude. Only in 2002 a complete and correct expression for this amplitude was obtained. Its low energy expansion was compared to the corresponding one from the low energy effective Lagrangian of the open superstring, finding a perfect match. A few years later, in 2005, it was realized that the 5-point formula could be written in a very much compact form, as a sum of two terms: each of them consisting of a momentum factor and a kinematic expression. This constituted a generalization of the 4-point amplitude case, which had been known to be cast in only one momentum factor multiplied by one kinematic expression. For this simplification to happen, known symmetries of the (tree level) scattering amplitudes were implemented in a manifest form. These symmetries are (on-shell) gauge symmetry, cyclic symmetry and twisting symmetry (or world sheet parity). In the recent years it has been realized that the N-point amplitude can be written as a sum of (N - 3)! terms (where N > 3). This result not only agrees with the 3, 4 and 5-point results, but also with the 6-point result which had been obtained by 2005, written as a sum of six terms. The expression that up to now has been obtained for the 6-point amplitude is quite complicated and, besides knowing that it consists of six terms, is not very illuminating. In this work we report on the recent result of writing the 6-point amplitude with gauge, cyclic and twisting symmetries manifest. Not only because of the manifest symmetries this result is important

Practical challenges related to point of care testing

Directory of Open Access Journals (Sweden)

Julie L.V. Shaw

2016-04-01

Full Text Available Point of care testing (POCT refers to laboratory testing that occurs near to the patient, often at the patient bedside. POCT can be advantageous in situations requiring rapid turnaround time of test results for clinical decision making. There are many challenges associated with POCT, mainly related to quality assurance. POCT is performed by clinical staff rather than laboratory trained individuals which can lead to errors resulting from a lack of understanding of the importance of quality control and quality assurance practices. POCT is usually more expensive than testing performed in the central laboratory and requires a significant amount of support from the laboratory to ensure the quality testing and meet accreditation requirements.Here, specific challenges related to POCT compliance with accreditation standards are discussed along with strategies that can be used to overcome these challenges. These areas include: documentation of POCT orders, charting of POCT results as well as training and certification of individuals performing POCT. Factors to consider when implementing connectivity between POCT instruments and the electronic medical record are also discussed in detail and include: uni-directional versus bidirectional communication, linking patient demographic information with POCT software, the importance of positive patient identification and considering where to chart POCT results in the electronic medical record. Keywords: Point of care Testing, Laboratory accreditation, Medical directive, Results documentation, Electronic Medical Record, Transcription error, Connectivity, Positive patient identification

Developing control points for halal slaughtering of poultry.

Science.gov (United States)

Shahdan, I A; Regenstein, J M; Shahabuddin, A S M; Rahman, M T

2016-07-01

Halal (permissible or lawful) poultry meat production must meet industry, economic, and production needs, and government health requirements without compromising the Islamic religious requirements derived from the Qur'an and the Hadiths (the actions and sayings of the Prophet Muhammad, peace and blessings be upon him). Halal certification authorities may vary in their interpretation of these teachings, which leads to differences in halal slaughter requirements. The current study proposes 6 control points (CP) for halal poultry meat production based on the most commonly used halal production systems. CP 1 describes what is allowed and prohibited, such as blood and animal manure, and feed ingredients for halal poultry meat production. CP 2 describes the requirements for humane handling during lairage. CP 3 describes different methods for immobilizing poultry, when immobilization is used, such as water bath stunning. CP 4 describes the importance of intention, details of the halal slaughter, and the equipment permitted. CP 5 and CP 6 describe the requirements after the neck cut has been made such as the time needed before the carcasses can enter the scalding tank, and the potential for meat adulteration with fecal residues and blood. It is important to note that the proposed halal CP program is presented as a starting point for any individual halal certifying body to improve its practices. © 2016 Poultry Science Association Inc.

CURB-BASED STREET FLOOR EXTRACTION FROM MOBILE TERRESTRIAL LIDAR POINT CLOUD

Directory of Open Access Journals (Sweden)

S. Ibrahim

2012-07-01

Full Text Available Mobile terrestrial laser scanners (MTLS produce huge 3D point clouds describing the terrestrial surface, from which objects like different street furniture can be generated. Extraction and modelling of the street curb and the street floor from MTLS point clouds is important for many applications such as right-of-way asset inventory, road maintenance and city planning. The proposed pipeline for the curb and street floor extraction consists of a sequence of five steps: organizing the 3D point cloud and nearest neighbour search; 3D density-based segmentation to segment the ground; morphological analysis to refine out the ground segment; derivative of Gaussian filtering to detect the curb; solving the travelling salesman problem to form a closed polygon of the curb and point-inpolygon test to extract the street floor. Two mobile laser scanning datasets of different scenes are tested with the proposed pipeline. The results of the extracted curb and street floor are evaluated based on a truth data. The obtained detection rates for the extracted street floor for the datasets are 95% and 96.53%. This study presents a novel approach to the detection and extraction of the road curb and the street floor from unorganized 3D point clouds captured by MTLS. It utilizes only the 3D coordinates of the point cloud.

Recent Developments in Maximum Power Point Tracking Technologies for Photovoltaic Systems

Directory of Open Access Journals (Sweden)

Nevzat Onat

2010-01-01

Full Text Available In photovoltaic (PV system applications, it is very important to design a system for operating of the solar cells (SCs under best conditions and highest efficiency. Maximum power point (MPP varies depending on the angle of sunlight on the surface of the panel and cell temperature. Hence, the operating point of the load is not always MPP of PV system. Therefore, in order to supply reliable energy to the load, PV systems are designed to include more than the required number of modules. The solution to this problem is that switching power converters are used, that is called maximum power point tracker (MPPT. In this study, the various aspects of these algorithms have been analyzed in detail. Classifications, definitions, and basic equations of the most widely used MPPT technologies are given. Moreover, a comparison was made in the conclusion.

Quantum critical point revisited by dynamical mean-field theory

Science.gov (United States)

Xu, Wenhu; Kotliar, Gabriel; Tsvelik, Alexei M.

2017-03-01

Dynamical mean-field theory is used to study the quantum critical point (QCP) in the doped Hubbard model on a square lattice. The QCP is characterized by a universal scaling form of the self-energy and a spin density wave instability at an incommensurate wave vector. The scaling form unifies the low-energy kink and the high-energy waterfall feature in the spectral function, while the spin dynamics includes both the critical incommensurate and high-energy antiferromagnetic paramagnons. We use the frequency-dependent four-point correlation function of spin operators to calculate the momentum-dependent correction to the electron self-energy. By comparing with the calculations based on the spin-fermion model, our results indicate the frequency dependence of the quasiparticle-paramagnon vertices is an important factor to capture the momentum dependence in quasiparticle scattering.

Effect of saddle-point anisotropy on point-defect drift-diffusion into straight dislocations

International Nuclear Information System (INIS)

Skinner, B.C.; Woo, C.H.

1983-02-01

Effects on point-defect drift-diffusion in the strain fields of edge or screw dislocations, due to the anisotropy of the point defect in its saddle-point configuration, are investigated. Expressions for sink strength and bias that include the saddle-point shape effect are derived, both in the absence and presence of an externally applied stress. These are found to depend on intrinsic parameters such as the relaxation volume and the saddle-point shape of the point defects, and extrinsic parameters such as temperature and the magnitude and direction of the externally applied stress with respect to the line direction and Burgers vector direction of the dislocation. The theory is applied to fcc copper and bcc iron. It is found that screw dislocations are biased sinks and that the stress-induced bias differential for the edge dislocations depends much more on the line direction than the Burgers vector direction. Comparison with the stress-induced bias differential due to the usual SIPA effect is made. It is found that the present effect causes a bias differential that is more than an order of magnitude larger

Handbook of floating-point arithmetic

CERN Document Server

Muller, Jean-Michel; de Dinechin, Florent; Jeannerod, Claude-Pierre; Joldes, Mioara; Lefèvre, Vincent; Melquiond, Guillaume; Revol, Nathalie; Torres, Serge

2018-01-01

This handbook is a definitive guide to the effective use of modern floating-point arithmetic, which has considerably evolved, from the frequently inconsistent floating-point number systems of early computing to the recent IEEE 754-2008 standard. Most of computational mathematics depends on floating-point numbers, and understanding their various implementations will allow readers to develop programs specifically tailored for the standard’s technical features. Algorithms for floating-point arithmetic are presented throughout the book and illustrated where possible by example programs which show how these techniques appear in actual coding and design. The volume itself breaks its core topic into four parts: the basic concepts and history of floating-point arithmetic; methods of analyzing floating-point algorithms and optimizing them; implementations of IEEE 754-2008 in hardware and software; and useful extensions to the standard floating-point system, such as interval arithmetic, double- and triple-word arithm...

Indexing Moving Points

DEFF Research Database (Denmark)

Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

2003-01-01

We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present an...

Inhibition effect of calcium hydroxide point and chlorhexidine point on root canal bacteria of necrosis teeth

Directory of Open Access Journals (Sweden)

Andry Leonard Je

2006-03-01

Full Text Available Calcium Hydroxide point and Chlorhexidine point are new drugs for eliminating bacteria in the root canal. The points slowly and controly realease Calcium Hydroxide and Chlorhexidine into root canal. The purpose of the study was to determined the effectivity of Calcium hydroxide point (Calcium hydroxide plus point and Chlorhexidine point in eleminating the root canal bacteria of nescrosis teeth. In this study 14 subjects were divided into 2 groups. The first group was treated with Calcium hydroxide point and the second was treated with Chlorhexidine poin. The bacteriological sampling were measured with spectrofotometry. The Paired T Test analysis (before and after showed significant difference between the first and second group. The Independent T Test which analysed the effectivity of both groups had not showed significant difference. Although there was no significant difference in statistical test, the result of second group eliminate more bacteria than the first group. The present finding indicated that the use of Chlorhexidine point was better than Calcium hydroxide point in seven days period. The conclusion is Chlorhexidine point and Calcium hydroxide point as root canal medicament effectively eliminate root canal bacteria of necrosis teeth.

Pro SharePoint 2013 administration

CERN Document Server

Garrett, Robert

2013-01-01

Pro SharePoint 2013 Administration is a practical guide to SharePoint 2013 for intermediate to advanced SharePoint administrators and power users, covering the out-of-the-box feature set and capabilities of Microsoft's collaboration and business productivity platform. SharePoint 2013 is an incredibly complex product, with many moving parts, new features, best practices, and 'gotchas.' Author Rob Garrett distills SharePoint's portfolio of features, capabilities, and utilities into an in-depth professional guide-with no fluff and copious advice-that is designed from scratch to be the manual Micr

Geodetic Control Points - Multi-State Control Point Database

Data.gov (United States)

NSGIC State | GIS Inventory — The Multi-State Control Point Database (MCPD) is a database of geodetic and mapping control covering Idaho and Montana. The control were submitted by registered land...

Surrogate end points in clinical research: hazardous to your health.

Science.gov (United States)

Grimes, David A; Schulz, Kenneth F

2005-05-01

Surrogate end points in clinical research pose real danger. A surrogate end point is an outcome measure, commonly a laboratory test, that substitutes for a clinical event of true importance. Resistance to activated protein C, for example, has been used as a surrogate for venous thrombosis in women using oral contraceptives. Other examples of inappropriate surrogate end points in contraception include the postcoital test instead of pregnancy to evaluate new spermicides, breakage and slippage instead of pregnancy to evaluate condoms, and bone mineral density instead of fracture to assess the safety of depo-medroxyprogesterone acetate. None of these markers captures the effect of the treatment on the true outcome. A valid surrogate end point must both correlate with and accurately predict the outcome of interest. Although many surrogate markers correlate with an outcome, few have been shown to capture the effect of a treatment (for example, oral contraceptives) on the outcome (venous thrombosis). As a result, thousands of useless and misleading reports on surrogate end points litter the medical literature. New drugs have been shown to benefit a surrogate marker, but, paradoxically, triple the risk of death. Thousands of patients have died needlessly because of reliance on invalid surrogate markers. Researchers should avoid surrogate end points unless they have been validated; that requires at least one well done trial using both the surrogate and true outcome. The clinical maxim that "a difference to be a difference must make a difference" applies to research as well. Clinical research should focus on outcomes that matter.

Set points, settling points and some alternative models: theoretical options to understand how genes and environments combine to regulate body adiposity

Directory of Open Access Journals (Sweden)

John R. Speakman

2011-11-01

Full Text Available The close correspondence between energy intake and expenditure over prolonged time periods, coupled with an apparent protection of the level of body adiposity in the face of perturbations of energy balance, has led to the idea that body fatness is regulated via mechanisms that control intake and energy expenditure. Two models have dominated the discussion of how this regulation might take place. The set point model is rooted in physiology, genetics and molecular biology, and suggests that there is an active feedback mechanism linking adipose tissue (stored energy to intake and expenditure via a set point, presumably encoded in the brain. This model is consistent with many of the biological aspects of energy balance, but struggles to explain the many significant environmental and social influences on obesity, food intake and physical activity. More importantly, the set point model does not effectively explain the ‘obesity epidemic’ – the large increase in body weight and adiposity of a large proportion of individuals in many countries since the 1980s. An alternative model, called the settling point model, is based on the idea that there is passive feedback between the size of the body stores and aspects of expenditure. This model accommodates many of the social and environmental characteristics of energy balance, but struggles to explain some of the biological and genetic aspects. The shortcomings of these two models reflect their failure to address the gene-by-environment interactions that dominate the regulation of body weight. We discuss two additional models – the general intake model and the dual intervention point model – that address this issue and might offer better ways to understand how body fatness is controlled.

IMPORTANCE OF MARKET UNDERSTANDING AS A DEVELOPMENT ASSUMPTION OF FAMILY FARMS

Directory of Open Access Journals (Sweden)

K. Zmaić

2002-12-01

Full Text Available The system of agricultural products must adjust to the numerous quality as well as quantity changes of the environment, and for such a successful adjustment, a certain knowledge of the market itself is absolutely necessary. The importance of agricultural products market is caused by the fact that it helps agricultural producers for a better sight of consumers’ requests with a purpose of meeting their needs. Defining of the basic characteristics of a market system and its importance are the primal points for the successful functioning of the agricultural activities related to the agricultural products sale. It means that aforesaid affects forming price which in turns affects the income height through the total sold agricultural products used by producers use as a motivation for increasing production. Development of agricultural production and importance of market facts are researched from the point of characteristic and specific market system, supply and demand, price trends and agriculture politics. The paper focused the fact which should be realized by agricultural producers. It comprises the importance of the adjustment to the needs of modern market, taking into account sizes and agricultural production program, as well as delivery time limit and the products sale on the market.

Feature Extraction from 3D Point Cloud Data Based on Discrete Curves

Directory of Open Access Journals (Sweden)

Yi An

2013-01-01

Full Text Available Reliable feature extraction from 3D point cloud data is an important problem in many application domains, such as reverse engineering, object recognition, industrial inspection, and autonomous navigation. In this paper, a novel method is proposed for extracting the geometric features from 3D point cloud data based on discrete curves. We extract the discrete curves from 3D point cloud data and research the behaviors of chord lengths, angle variations, and principal curvatures at the geometric features in the discrete curves. Then, the corresponding similarity indicators are defined. Based on the similarity indicators, the geometric features can be extracted from the discrete curves, which are also the geometric features of 3D point cloud data. The threshold values of the similarity indicators are taken from [0,1], which characterize the relative relationship and make the threshold setting easier and more reasonable. The experimental results demonstrate that the proposed method is efficient and reliable.

Comparative study of building footprint estimation methods from LiDAR point clouds

Science.gov (United States)

Rozas, E.; Rivera, F. F.; Cabaleiro, J. C.; Pena, T. F.; Vilariño, D. L.

2017-10-01

Building area calculation from LiDAR points is still a difficult task with no clear solution. Their different characteristics, such as shape or size, have made the process too complex to automate. However, several algorithms and techniques have been used in order to obtain an approximated hull. 3D-building reconstruction or urban planning are examples of important applications that benefit of accurate building footprint estimations. In this paper, we have carried out a study of accuracy in the estimation of the footprint of buildings from LiDAR points. The analysis focuses on the processing steps following the object recognition and classification, assuming that labeling of building points have been previously performed. Then, we perform an in-depth analysis of the influence of the point density over the accuracy of the building area estimation. In addition, a set of buildings with different size and shape were manually classified, in such a way that they can be used as benchmark.

Numerical analysis of slowest heating or cooling point in a canned food in oil

Energy Technology Data Exchange (ETDEWEB)

Hanzawa, T.; Wang, Q.; Suzuki, M.; Sakai, N. [Tokyo Univ. of Fisheries (Japan)

1998-06-01

In the sterilizing process of canned food in oil for a fish meat such as tunny, the slowest heating or cooling point is very important for the thermal process determination of the can. To obtain the slowest point, the temperature profiles in solid food are estimated by numerical calculation from the fundamental equations at unsteady state in consideration of a free convection in the space occupied by the oil. The positions of the slowest heating or cooling point in the canned food in oil are obtained accurately, and a correlative equation for the position is obtained numerically under various operating conditions. The calculated temperature profiles and the position of both slowest points are in sufficiently good approximation to the experimental ones. 4 refs., 9 figs.

Modelling point patterns with linear structures

DEFF Research Database (Denmark)

Møller, Jesper; Rasmussen, Jakob Gulddahl

2009-01-01

processes whose realizations contain such linear structures. Such a point process is constructed sequentially by placing one point at a time. The points are placed in such a way that new points are often placed close to previously placed points, and the points form roughly line shaped structures. We...... consider simulations of this model and compare with real data....

Modelling point patterns with linear structures

DEFF Research Database (Denmark)

Møller, Jesper; Rasmussen, Jakob Gulddahl

processes whose realizations contain such linear structures. Such a point process is constructed sequentially by placing one point at a time. The points are placed in such a way that new points are often placed close to previously placed points, and the points form roughly line shaped structures. We...... consider simulations of this model and compare with real data....

Predictors, Prognosis, and Management of New Clinically Important Atrial Fibrillation After Noncardiac Surgery: A Prospective Cohort Study.

Science.gov (United States)

Alonso-Coello, Pablo; Cook, Deborah; Xu, Shou Chun; Sigamani, Alben; Berwanger, Otavio; Sivakumaran, Soori; Yang, Homer; Xavier, Denis; Martinez, Luz Ximena; Ibarra, Pedro; Rao-Melacini, Purnima; Pogue, Janice; Zarnke, Kelly; Paniagua, Pilar; Ostrander, Jack; Yusuf, Salim; Devereaux, P J

2017-07-01

Despite the frequency of new clinically important atrial fibrillation (AF) after noncardiac surgery and its increased association with the risk of stroke at 30 days, there are limited data informing their prediction, association with outcomes, and management. We used the data from the PeriOperative ISchemic Evaluation trial to determine, in patients undergoing noncardiac surgery, the association of new clinically important AF with 30-day outcomes, and to assess management of these patients. We also aimed to derive a clinical prediction rule for new clinically important AF in this population. We defined new clinically important AF as new AF that resulted in symptoms or required treatment. We recorded an electrocardiogram 6 to 12 hours postoperatively and on the 1st, 2nd, and 30th days after surgery. A total of 211 (2.5% [8351 patients]; 95% confidence interval, 2.2%-2.9%) patients developed new clinically important AF within 30 days of randomization (8140 did not develop new AF). AF was independently associated with an increased length of hospital stay by 6.0 days (95% confidence interval, 3.5-8.5 days) and vascular complications (eg, stroke or congestive heart failure). The usage of an oral anticoagulant at the time of hospital discharge among patients with new AF and a CHADS2 score of 0, 1, 2, 3, and ≥4 was 6.9%, 10.2%, 23.0%, 9.4%, and 33.3%, respectively. Two independent predictors of patients developing new clinically important AF were identified (ie, age and surgery). The prediction rule included the following factors and assigned weights: age ≥85 years (4 points), age 75 to 84 years (3 points), age 65 to 74 years (2 points), intrathoracic surgery (3 points), major vascular surgery (2 points), and intra-abdominal surgery (1 point). The incidence of new AF based on scores of 0 to 1, 2, 3 to 4, and 5 to 6 was 0.5%, 1.0%, 3.1%, and 5.3%, respectively. Age and surgery are independent predictors of new clinically important AF in the perioperative setting. A

Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

Directory of Open Access Journals (Sweden)

Ahmed M. Othman

2012-12-01

Full Text Available In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV systems. Maximum power point tracking (MPPT plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O algorithm and is compared to a designed fuzzy logic controller (FLC. The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

State Level Point-of-Sale Policy Priority as a Result of the FSPTCA.

Science.gov (United States)

Moreland-Russell, Sarah; Combs, Todd; Jones, Janice; Sorg, Amy A

2015-01-01

The Family Smoking Prevention and Tobacco Control Act (FSPTCA) give the U.S. Food and Drug Administration (FDA) unprecedented power to regulate tobacco products. One of the most significant provisions of the law allows state and local governments to adopt and enforce tobacco control legislation restricting the time, place, and manner (but not the content) of tobacco advertising. However, there is still reluctance among states and localities for mass adoption of laws due to challenges associated with legal feasibility and lack of U.S.-based evidence in effectiveness. The Center for Public Health Systems Science conducted interviews with key tobacco control contacts in 48 states at two time points (2012 and 2014) since the passage of the FSPTCA to assess the influence of the law on point-of-sale policy development in their state tobacco programs. Logistic regression results show that point-of-sale policy importance is growing post-FSPTCA, and that key influencers of this importance are states' tobacco control histories and environments, including that related to excise taxes and smoke free air policies. The adoption of smokefree and tax policies has become commonplace across the U.S., and the quality and extent of these laws and prevailing political will increasingly impact the ability of states to work in emerging tobacco control policy areas including those directed at the point of sale.

Ecological change points: The strength of density dependence and the loss of history.

Science.gov (United States)

Ponciano, José M; Taper, Mark L; Dennis, Brian

2018-05-01

Change points in the dynamics of animal abundances have extensively been recorded in historical time series records. Little attention has been paid to the theoretical dynamic consequences of such change-points. Here we propose a change-point model of stochastic population dynamics. This investigation embodies a shift of attention from the problem of detecting when a change will occur, to another non-trivial puzzle: using ecological theory to understand and predict the post-breakpoint behavior of the population dynamics. The proposed model and the explicit expressions derived here predict and quantify how density dependence modulates the influence of the pre-breakpoint parameters into the post-breakpoint dynamics. Time series transitioning from one stationary distribution to another contain information about where the process was before the change-point, where is it heading and how long it will take to transition, and here this information is explicitly stated. Importantly, our results provide a direct connection of the strength of density dependence with theoretical properties of dynamic systems, such as the concept of resilience. Finally, we illustrate how to harness such information through maximum likelihood estimation for state-space models, and test the model robustness to widely different forms of compensatory dynamics. The model can be used to estimate important quantities in the theory and practice of population recovery. Copyright © 2018 Elsevier Inc. All rights reserved.

State level point-of-sale policy priority as a result of the FSPTCA

Directory of Open Access Journals (Sweden)

Sarah Moreland-Russell PhD MPH

2015-10-01

Full Text Available The Family Smoking Prevention and Tobacco Control Act (FSPTCA give the U.S. Food and Drug Administration (FDA unprecedented power to regulate tobacco products. One of the most significant provisions of the law allows state and local governments to adopt and enforce tobacco control legislation restricting the time, place, and manner (but not the content of tobacco advertising. However, there is still reluctance among states and localities for mass adoption of laws due to challenges associated with legal feasibility and lack of U.S.-based evidence in effectiveness. The Center for Public Health Systems Science conducted interviews with key tobacco control contacts in 48 states at two time points (2012 and 2014 since the passage of the FSPTCA to assess the influence of the law on point-of-sale policy development in their state tobacco programs. Logistic regression results show that point-of-sale policy importance is growing post-FSPTCA, and that key influencers of this importance are states' tobacco control histories and environments, including that related to excise taxes and smoke free air policies. The adoption of smokefree and tax policies has become commonplace across the U.S., and the quality and extent of these laws and prevailing political will increasingly impact the ability of states to work in emerging tobacco control policy areas including those directed at the point of sale.

Bifurcations and degenerate periodic points in a three dimensional chaotic fluid flow

International Nuclear Information System (INIS)

Smith, L. D.; Rudman, M.; Lester, D. R.; Metcalfe, G.

2016-01-01

Analysis of the periodic points of a conservative periodic dynamical system uncovers the basic kinematic structure of the transport dynamics and identifies regions of local stability or chaos. While elliptic and hyperbolic points typically govern such behaviour in 3D systems, degenerate (parabolic) points also play an important role. These points represent a bifurcation in local stability and Lagrangian topology. In this study, we consider the ramifications of the two types of degenerate periodic points that occur in a model 3D fluid flow. (1) Period-tripling bifurcations occur when the local rotation angle associated with elliptic points is reversed, creating a reversal in the orientation of associated Lagrangian structures. Even though a single unstable point is created, the bifurcation in local stability has a large influence on local transport and the global arrangement of manifolds as the unstable degenerate point has three stable and three unstable directions, similar to hyperbolic points, and occurs at the intersection of three hyperbolic periodic lines. The presence of period-tripling bifurcation points indicates regions of both chaos and confinement, with the extent of each depending on the nature of the associated manifold intersections. (2) The second type of bifurcation occurs when periodic lines become tangent to local or global invariant surfaces. This bifurcation creates both saddle–centre bifurcations which can create both chaotic and stable regions, and period-doubling bifurcations which are a common route to chaos in 2D systems. We provide conditions for the occurrence of these tangent bifurcations in 3D conservative systems, as well as constraints on the possible types of tangent bifurcation that can occur based on topological considerations.

Beginning SharePoint Designer 2010

CERN Document Server

Windischman, Woodrow W; Rehmani, Asif

2010-01-01

Teaching Web designers, developers, and IT professionals how to use the new version of SharePoint Designer. Covering both the design and business applications of SharePoint Designer, this complete Wrox guide brings readers thoroughly up to speed on how to use SharePoint Designer in an enterprise. You'll learn to create and modify web pages, use CSS editing tools to modify themes, use Data View to create interactivity with SharePoint and other data, and much more. Coverage includes integration points with Visual Studio, Visio, and InfoPath.: Shows web designers, developers, and IT professionals

SharePoint 2013 for dummies

CERN Document Server

Withee, Ken

2013-01-01

The bestselling guide on running SharePoint, now updated to cover all the new features of SharePoint 2013 SharePoint Portal Server is an essential part of the enterprise infrastructure for many businesses. Building on the success of previous versions of SharePoint For Dummies, this new edition covers all the latest features of SharePoint 2013 and provides you with an easy-to-understand resource for making the most of all that this version has to offer. You'll learn how to get a site up and running, branded, and populated with content, workflow, and management. In addition, t

Pro SharePoint 2010 Search

CERN Document Server

Noble, J; Bakman-Mikalski, Dan

2011-01-01

Pro SharePoint 2010 Search gives you expert advice on planning, deploying and customizing searches in SharePoint 2010. Drawing on the authors' extensive experience of working with real-world SharePoint deployments, this book teaches everything you'll need to know to create well-designed SharePoint solutions that always keep the end-user's experience in mind. Increase your search efficiency with SharePoint 2010's search functionality: extend the search user interface using third-party tools, and utilize analytics to improve relevancy. This practical hands-on book is a must-have resource for any

Application of change-point problem to the detection of plant patches.

Science.gov (United States)

López, I; Gámez, M; Garay, J; Standovár, T; Varga, Z

2010-03-01

In ecology, if the considered area or space is large, the spatial distribution of individuals of a given plant species is never homogeneous; plants form different patches. The homogeneity change in space or in time (in particular, the related change-point problem) is an important research subject in mathematical statistics. In the paper, for a given data system along a straight line, two areas are considered, where the data of each area come from different discrete distributions, with unknown parameters. In the paper a method is presented for the estimation of the distribution change-point between both areas and an estimate is given for the distributions separated by the obtained change-point. The solution of this problem will be based on the maximum likelihood method. Furthermore, based on an adaptation of the well-known bootstrap resampling, a method for the estimation of the so-called change-interval is also given. The latter approach is very general, since it not only applies in the case of the maximum-likelihood estimation of the change-point, but it can be also used starting from any other change-point estimation known in the ecological literature. The proposed model is validated against typical ecological situations, providing at the same time a verification of the applied algorithms.

Foot placement indicator for balance of planar bipeds with point feet

NARCIS (Netherlands)

Zutven, van P.W.M.; Nijmeijer, H.

2013-01-01

When humanoid robots are going to be used in society, they should be capable to maintain the balance. Knowing where to step appears to be crucially important to remain balanced. In this paper we contribute an algorithm for planar bipeds with point feet and an arbitrary number of non-massless links

Impurity diffusion, point defect engineering, and surface/interface passivation in germanium

KAUST Repository

Chroneos, Alexander I.

2012-01-26

In recent years germanium has been emerging as a mainstream material that could have important applications in the microelectronics industry. The principle aim of this study is to review investigations of the diffusion of technologically important p- and n-type dopants as well as surface and interface passivation issues in germanium. The diffusion of impurities in germanium is interrelated to the formation of clusters whenever possible, and possibilities for point defect engineering are discussed in view of recent results. The importance of electrically active defects on the Ge surface and interfaces is addressed considering strategies to suppress them and to passivate the surfaces/interfaces, bearing in mind their importance for advanced devices. © 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

On Motion Planning for Point-to-Point Maneuvers for a Class of Sailing Vehicles

DEFF Research Database (Denmark)

Xiao, Lin; Jouffroy, Jerome

2011-01-01

Despite their interesting dynamic and controllability properties, sailing vehicles have not been much studied in the control community. In this paper, we investigate motion planning of such vehicles. Starting from a simple dynamic model of sailing vessels in one dimension, this paper first...... considers their associated controllability issues, with the so-called no-sailing zone as a starting point, and it links them with a motion planning strategy using two-point boundary value problems as the main mathematical tool. This perspective is then expanded to do point-to-point maneuvers of sailing...

Making Sense of Boiling Points and Melting Points

Indian Academy of Sciences (India)

GENERAL | ARTICLE. The boiling and melting points of a pure substance are char- ... bonds, which involves high energy and hence high temperatures. Among the .... with zero intermolecular force at all temperatures and pressures, which ...

Octopuses use a human-like strategy to control precise point-to-point arm movements.