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Sample records for supine oblique view

  1. The oblique supine decubitus position: technical description and comparison of results with the prone decubitus and dorsal supine decubitus positions.

    Science.gov (United States)

    Arrabal-Martin, Miguel; Arrabal-Polo, Miguel A; Lopez-Leon, Victor; Merino-Salas, Sergio; Palao-Yago, Francisco; Cámara-Ortega, Manuel; Zuluaga-Gomez, Armando

    2012-10-01

    Our objective was to analyze the advantages of the percutaneous nephrolithotomy in oblique supine decubitus compared to the prone and dorsal supine position. In 87 patients diagnosed with urolithiasis (495.5-530.8 mm(2)), percutaneous nephrolithotomy (PNL) was performed from 2000 to 2011. The patients were divided into three groups: Group A, 32 patients, PNL in the prone decubitus position; Group B, 24 patients, PNL in the dorsal supine position; Group C, 31 patients, PNL in the oblique supine position. We analyzed intraoperative parameters, complications, and results among the three groups. The three procedures were performed with a single access, 24-30 Ch. No statistically significant differences were found among the three groups regarding the patients' characteristics, or the morphology or size of the kidney stone treated. The operation time was shorter in the cases of PNL in dorsal supine and oblique supine compared to the prone position. The complication rate was very similar in the three groups. The main advantage of the PNL in oblique supine compared to the dorsal supine was that the puncture could in all cases be directed by ultrasonography, with greater precision, more safety, and more control of the percutaneous renal access. The oblique supine decubitus position is a safe position for the percutaneous treatment of urolithiasis and it becomes easier when the puncture is guided by ultrasound.

  2. Cervical spine trauma radiographs: Swimmers and supine obliques; an exploration of current practice

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    Fell, Michael, E-mail: michael.fell@mkgeneral.nhs.u [Milton Keynes General Hospital, Radiology Standing Way, Eaglestone, Milton Keynes, Buckinghamshire MK6 5LD (United Kingdom)

    2011-02-15

    The study objectives were: to investigate current cervical spine radiographic imaging practices in conscious adult patients with suspected neck injury; reasons behind variation and consideration of dose estimates were explored. Comparison with a previous survey has been made. Questionnaires were sent to superintendent radiographers responsible for accident and emergency X-ray departments in English trusts with over 8500 emergency admissions per year, with a response rate of 97% (n = 181/186). Departmental cervical spine imaging protocols were reported by 82% of respondents. None use fewer than the three standard projections; if the cervicothoracic junction (C7/T1), is not adequately demonstrated 87% use swimmers projections, 9% supine obliques, 3% CT alone. Following projectional radiography, 97% perform CT. A significant (p = 0.018) increase was found since 1999 in CT use once the swimmers projection fails; fewer now use obliques at this point, continuing with CT instead. No significant difference (p = 0.644) was found in choice of first supplementary radiographs; despite British Trauma Society's recommendation to undertake supine obliques, swimmers remain the most widespread technique. An 85% response rate (n = 103/121) completed a second questionnaire, exploring reasons behind the various practices. Several reported a perceived difficulty in interpreting oblique radiographs, some a concern over high dose of the swimmers. Numerous issues affect the acquisition of cervical spine radiographs. Patient radiation dose should be a major consideration in selection of technique. A potential need for training in interpretation of obliques is highlighted. Specific guidelines for optimum projections should be researched, and protocols issued to ensure best practice.

  3. Suggestion of Modified Y-View in Supine Position

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    Shin, Seong Gyu [Dept. of Radiology, Dong A University Medicine Center, Busan (Korea, Republic of); Baek, Seong Min [Dept. of Nuclear Medicine, Kosin University Gospel Hospital, Busan (Korea, Republic of); Lee, Hyo Yeong [Dept. of Nuclear Medicine, Pusan National University Hospital, Busan (Korea, Republic of)

    2012-06-15

    This study was performed to design a modified Y-View as an imaging method for the Y-View in supine position for patients who requires Y-View imaging for the diagnosis of shoulder impingement syndrome but having trouble for the positioning of patients complaining of shoulder pain. On the result of comparative analysis of the images obtained by changing the lateral-medio degree of X-ray tube into 35 degrees, 40 degrees, and 45 degrees while patient is in supine position, 40 degrees of X-ray tube in lateral-medio direction produced the most valuable image for the diagnosis by best describing the shapes of acromion, clavicle space, and coracoacromial arch. Therefore, patients who have difficulty in Y-View position to obtain Y-View image, modified Y-View can be applied as a useful alternative method. By this study, various applications not only in shoulder impingement syndrome but also in diverse omarthralgia diseases are expected.

  4. Assessment of the effective dose in supine, prone, and oblique positions in the maxillofacial region using a novel combined extremity and maxillofacial cone beam computed tomography scanner

    NARCIS (Netherlands)

    Koivisto, J.; Wolff, J.; Järnstedt, J.; Dastidar, P.; Kortesniemi, M.

    2014-01-01

    Objective The objectives of this study were to assess the organ and effective doses (International Commission on Radiological Protection [ICRP] 103 standard) resulting from supine, prone, and oblique phantom positions in the maxillofacial region using a novel cone beam computed tomography (CBCT) dev

  5. The Oblique Basis Method from an Engineering Point of View

    Science.gov (United States)

    Gueorguiev, V. G.

    2012-12-01

    The oblique basis method is reviewed from engineering point of view related to vibration and control theory. Examples are used to demonstrate and relate the oblique basis in nuclear physics to the equivalent mathematical problems in vibration theory. The mathematical techniques, such as principal coordinates and root locus, used by vibration and control theory engineers are shown to be relevant to the Richardson - Gaudin pairing-like problems in nuclear physics.

  6. The Oblique Basis Method from an Engineering Point of View

    OpenAIRE

    Gueorguiev, V. G.

    2012-01-01

    The oblique basis method is reviewed from engineering point of view related to vibration and control theory. Examples are used to demonstrate and relate the oblique basis in nuclear physics to the equivalent mathematical problems in vibration theory. The mathematical techniques, such as principal coordinates and root locus, used by vibration and control theory engineers are shown to be relevant to the Richardson - Gaudin pairing-like problems in nuclear physics.

  7. What is the real angle of deviation of metacarpal neck fractures on oblique views? A radiographic study☆

    Science.gov (United States)

    de Góes Ribeiro, Arthur; Gonçalez, Daniel Hidalgo; Filho, João Manoel Fonseca; da Fonseca, Guilherme Marques; Costa, Antonio Carlos; Chakkour, Ivan

    2016-01-01

    Objective The aim of this study was to establish an indirect, easy-to-use, predictable and safe means of obtaining the true degree of displacement of fractures of the neck of the fifth metacarpal bone, through oblique radiographic views. Methods An anatomical specimen from the fifth human metacarpal was dissected and subjected to ostectomy in the neck region. A 1-mm Kirschner wire was fixed to the base of the fifth metacarpal bone, perpendicular to the longitudinal axis of the bone and parallel to the ground. Another six Kirschner wires of the same diameter were bent over and attached to the ostectomized bone to simulate fracture displacement. Axial rotation of the metacarpus was used to create oblique radiographic views. Radiographic images were generated with different angles and at several degrees of rotation of the bone. Results We deduced a mathematical formula that showed the true displacement of fractures of the neck of the fifth metacarpal bone by means of oblique radiographs. Conclusions Oblique radiographs at 30̊ of supination provided the best view of the bone and least variation from the real value of the displacement of fractures of the fifth metacarpal bone. The mathematical formula deduced was concordant with the experimental model used. PMID:27069882

  8. ADAPTIVE HIERARCHICAL DENSE MATCHING OF MULTI-VIEW AIRBORNE OBLIQUE IMAGERY

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    Z. C. Zhang

    2015-03-01

    Full Text Available Traditional single-lens vertical photogrammetry can obtain object images from the air with rare lateral information of tall buildings. Multi-view airborne photogrammetry can get rich lateral texture of buildings, while the common area-based matching for oblique images may lose efficacy because of serious geometric distortion. A hierarchical dense matching algorithm is put forward here to match two oblique airborne images of different perspectives. Based on image hierarchical strategy and matching constraints, this algorithm delivers matching results from the upper layer of the pyramid to the below and implements per-pixel dense matching in the local Delaunay triangles between the original images. Experimental results show that the algorithm can effectively overcome the geometric distortion between different perspectives and achieve pixel-level dense matching entirely based on the image space.

  9. Early detection of breast cancer using only oblique medium lateral view; Deteccao precoce do cancer de mama com apenas uma incidencia mamografica: a obliqua medio-lateral

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    Aguillar, Vera L.N. [Escola Paulista de Medicina, Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem

    1996-09-01

    To compare the advantages of one- versus two-views mammography, screening films were reviewed from 1,500 asymptomatic women undergoing mammography. Two separate interpretations were made of each case, one using only the oblique projection images, the other using both oblique and cranio caudal views. In women with dense breasts, one view readings resulted in much more frequent abnormal interpretations, false positives, than two-views readings. In contrast, in woman with primary fatty breast, in whom superimposition of dense tissue on image is not a problem, it may be reasonable to obtain a single mediolateral projection to follow-up screening mammography. (author). 50 refs., 4 figs.

  10. Numerical evaluation of moiré pattern in touch sensor module with electrode mesh structure in oblique view

    Science.gov (United States)

    Pournoury, M.; Zamiri, A.; Kim, T. Y.; Yurlov, V.; Oh, K.

    2016-03-01

    Capacitive touch sensor screen with the metal materials has recently become qualified for substitution of ITO; however several obstacles still have to be solved. One of the most important issues is moiré phenomenon. The visibility problem of the metal-mesh, in touch sensor module (TSM) is numerically considered in this paper. Based on human eye contract sensitivity function (CSF), moiré pattern of TSM electrode mesh structure is simulated with MATLAB software for 8 inch screen display in oblique view. Standard deviation of the generated moiré by the superposition of electrode mesh and screen image is calculated to find the optimal parameters which provide the minimum moiré visibility. To create the screen pixel array and mesh electrode, rectangular function is used. The filtered image, in frequency domain, is obtained by multiplication of Fourier transform of the finite mesh pattern (product of screen pixel and mesh electrode) with the calculated CSF function for three different observer distances (L=200, 300 and 400 mm). It is observed that the discrepancy between analytical and numerical results is less than 0.6% for 400 mm viewer distance. Moreover, in the case of oblique view due to considering the thickness of the finite film between mesh electrodes and screen, different points of minimum standard deviation of moiré pattern are predicted compared to normal view.

  11. Should one compute the Temporal Difference fix point or minimize the Bellman Residual? The unified oblique projection view

    CERN Document Server

    Scherrer, Bruno

    2010-01-01

    We investigate projection methods, for evaluating a linear approximation of the value function of a policy in a Markov Decision Process context. We consider two popular approaches, the one-step Temporal Difference fix-point computation (TD(0)) and the Bellman Residual (BR) minimization. We describe examples, where each method outperforms the other. We highlight a simple relation between the objective function they minimize, and show that while BR enjoys a performance guarantee, TD(0) does not in general. We then propose a unified view in terms of oblique projections of the Bellman equation, which substantially simplifies and extends the characterization of (schoknecht,2002) and the recent analysis of (Yu & Bertsekas, 2008). Eventually, we describe some simulations that suggest that if the TD(0) solution is usually slightly better than the BR solution, its inherent numerical instability makes it very bad in some cases, and thus worse on average.

  12. Simultaneous display of MRA and MPR in detecting vascular compression for trigeminal neuralgia or hemifacial spasm: comparison with oblique sagittal views of MRI

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    Arbab, A.S.; Aoki, S.; Yoshikawa, T.; Kumagai, H.; Araki, T. [Department of Radiology, Yamanashi Medical University, Yamanashi 409-3898 (Japan); Nishiyama, Y.; Nagaseki, Y.; Nukui, H. [Department of Neurosurgery, Yamanashi Medical University, Yamanashi 409-3898 (Japan)

    2000-07-01

    A new technique, simultaneous display of magnetic resonance angiography (MRA) and multiplanar reconstruction (MPR), was performed by a workstation to identify the involved vessels in patients with trigeminal neuralgia (TN) or hemifacial spasm (HFS), and the results were compared with those of oblique sagittal MRI technique. Twelve patients with either HFS or TN were prospectively assessed by simultaneous display of MRA and MPR, and oblique sagittal techniques, to point out the neurovascular compression and to identify the involved vessels. Three-dimensional (3D) time-of-flight (TOF) spoiled gradient-echo (SPGR) images were acquired to create MRA and MPR. Oblique sagittal views were also created and displayed on films. A total of 15 vessels in 12 patients were identified as compressing vessels during surgery. Simultaneous display of MRA and MPR technique pointed out the presence of vessels at and/or around root entry/exit zone (REZ) in all 12 patients, but proper identification by the name of the individual vessel was correct in 13 of 15 cases. However, oblique sagittal technique indicated the presence of vessels at and/or around REZ in 11 patients, but only 8 of 14 vessels were correctly identified. Our new method, simultaneous display of MRA-MPR, facilitated correct identification of the involved vessels compared with the oblique sagittal view method. (orig.)

  13. Atmospheric correction of thermal-infrared imagery of the 3-D urban environment acquired in oblique viewing geometry

    Directory of Open Access Journals (Sweden)

    F. Meier

    2010-12-01

    Full Text Available This research quantifies and discusses atmospheric effects that alter the radiance observed by a ground-based thermal-infrared (TIR camera mounted on top of a high-rise building in the city of Berlin, Germany. The study shows that atmospheric correction of ground-based TIR imagery of the three-dimensional (3-D urban environment acquired in oblique viewing geometry has to account for spatial variability of line-of-sight (LOS geometry. We present an atmospheric correction procedure that uses these spatially distributed LOS geometry parameters, the radiative transfer model MODTRAN 5.2 and atmospheric profile data derived from meteorological measurements in the field of view (FOV of the TIR camera. The magnitude of atmospheric effects varies during the analysed 24-hourly period (8 August 2009 and is particularly notable for surfaces showing a strong surface-to-air temperature difference. The differences between uncorrected and corrected TIR imagery reach up to 7.7 K at 12:00. Atmospheric effects are biased up to 4.3 K at 12:00 and up to 0.6 K at 24:00, if non-spatially distributed LOS parameters are used.

  14. Computational studies on ECE spectrum for ITER, in the presence of a small fraction of non-thermals and radial resolution evolution for oblique view

    Directory of Open Access Journals (Sweden)

    Subhash P.V.

    2015-01-01

    Full Text Available In tokamaks, the temperature measurement using different techniques like Electron Cyclotron Emission (ECE, Thomson scattering etc. shows differences because of various phenomena. The physical reasons for this are not entirely understood. Thus to have comprehensive understanding of these difference, the contribution from each phenomenon needs to be individually understood. The phenomenon affecting radial temperature profile measurement includes harmonics overlap, relativistic down shifting, presence of non-thermals etc. For ITER like plasma, radial temperature profiles can be obtained from the first harmonics ordinary (O mode or second harmonic extra-ordinary(X mode of ECE spectrum. It is possible that, higher harmonics produced from the non-thermals can be relativistically downshifted to second harmonics and results a deviation in the measured temperature profile. We performed a parametric study on the effect of non-thermal electrons on measured ECE temperature for ITER scenario-2. All the numerical calculations reported in this paper are performed using NOTEC computer code which is capable of handling non-thermal populations. After proper validation of numerical methods using normal electron population (without non-thermals a parametric study with non-thermals is performed. In the parametric study radial locations of non-thermals, energy of non-thermals and fraction of non-thermals are considered. This study is initially performed for normal view and later extended in to oblique views. The range of deviation of temperature over the examined parametric regime as well as the possible physical reasons will be presented. The effect of parallel component of non-thermal energy is also examined. Finally results of one set of study for oblique view (where the detector is not exactly normal to the magnetic field with non-thermal electrons are also presented. In ITER apart from an Electron Cyclotron Emission (ECE detector placed normal to magnetic field

  15. Magnetic resonance imaging of vascular compression in trigeminal neuralgia and hemifacial spasms; The efficacy of oblique sagittal view

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    Nagaseki, Yoshishige; Horikoshi, Tohru; Omata, Tomohiro; Sugita, Masao; Nukui, Hideaki; Sakamoto, Hajime; Kumagai, Hiroshi (Yamanashi Medical College, Tamaho (Japan)); Sasaki, Hideo; Tsuji, Reizou

    1991-06-01

    We show how neurosurgical planning can benefit from the better visualization of the precise vascular compression of the nerve provided by the oblique-sagittal and gradient-echo method (OS-GR image) using magnetic resonance images (MRI). The scans of 3 patients with trigeminal neuralgia (TN) and of 15 with hemifacial spasm (HFS) were analyzed for the presence and appearance of the vascular compression of the nerves. Imaging sequences consisted of an OS-GR image (TR/TE: 200/20, 3-mm-thick slice) cut along each nerve shown by the axial view, which was scanned at the angle of 105 degrees taken between the dorsal line of the brain stem and the line corresponding to the pontomedullary junction. In the OS-GR images of the TN's, the vascular compressions of the root entry zone (REZ) of the trigeminal nerve were well visualized as high-intensity lines in the 2 cases whose vessels were confirmed intraoperatively. In the other case, with atypical facial pain, vascular compression was confirmed at the rostral distal site on the fifth nerve, apart from the REZ. In the 15 cases of HFS, twelve OS-GR images (80%) demonstrated vascular compressions at the REZ of the facial nerves from the direction of the caudoventral side. During the surgery for these 12 cases, in 11 cases (excepting the 1 case whose facial nerve was not compressed by any vessels), vascular compressions were confirmed corresponding to the findings of the OS-GR images. Among the 10 OS-GR images on the non-affected side, two false-positive findings were visualized. It is concluded that OS-GR images obtained by means of MRI may serve as a useful planning aid prior to microvascular decompression for cases of TN and HFS. (author).

  16. Replacing single-view mediolateral oblique (MLO) digital mammography (DM) with synthesized mammography (SM) with digital breast tomosynthesis (DBT) images: Comparison of the diagnostic performance and radiation dose with two-view DM with or without MLO-DBT.

    Science.gov (United States)

    Kang, Hyo-Jin; Chang, Jung Min; Lee, Joongyub; Song, Sung Eun; Shin, Sung Ui; Kim, Won Hwa; Bae, Min Sun; Moon, Woo Kyung

    2016-11-01

    To evaluate the diagnostic performance and radiation dose of single view cranio-caudal (CC) digital mammography (DM) plus mediolateral oblique (MLO) digital breast tomosynthesis (DBT) combined with synthesized mammography (SM) in comparison with two-view DM with or without DBT. This study was approved by our institutional review board, and informed consent was obtained from 130 women. Paired two-view DM and single MLO-DBT with SM images were acquired, and four independent retrospective reading sessions of different combinations of DM, SM and DBT were performed for the presence of malignant tumors using jackknife alternative free-response receiver operator curve (JAFROC) methods. The diagnostic performances and average glandular dose (AGD) were compared between different combinations of DM, SM and DBT. Of 159 lesions in 130 patients, 27 were malignant. When using MLO-DBT with SM instead of MLO-DM, a significantly higher sensitivity (P=0.016) and specificity (P=0.012) were noted than with two-view DM, and comparable figure of merit (FOM), sensitivity, and specificity to two-view DM with DBT were noted. The mean AGD of CC-DM plus MLO-DBT with SM was 5.78mGy±1.06 per patient, which was significantly lower than that with two-view DM with MLO-DBT (8.45mGy±1.32; P <0.001) and slightly higher than that with two-view DM (5.30mGy±0.63). The combined use of CC-DM plus MLO-DBT with SM showed higher sensitivity and specificity to two-view DM with a smaller AGD increment and comparable diagnostic performance to that of two-view DM with MLO-DBT with a significantly lower mean AGD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. A comparison of the oblique sagittal view obtained by magnetic resonance imaging and the intraoperative findings of vascular compression in cases of trigeminal neuralgia and hemifacial spasm

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    Nagaseki, Yoshishige; Horikoshi, Tohru; Omata, Tomohiro; Ueno, Takehiko; Uchida, Mikito; Nukui, Hideaki (Yamanashi Medical Coll., Tamaho (Japan)); Sasaki, Hideo; Tsuji, Reizou

    1992-06-01

    We show how neurosurgical planning can benefit from the better visualization of the precise vascular compression of the nerves provided by the oblique sagittal and gradient-echo method (OS-GR image) using magnetic resonance images (MRI) and by comparing these results with the findings of microvascular decompression. The scans of 5 patients with trigeminal neuralgia (TN) and 18 with hemifacial spasm (HFS) were analysed for the presence and appearance of the vascular compression of the nerves; all these 23 patients were operated on. Imaging sequences consisted of an OS-GR image (TR/TE: 200/20, 3-mm-thick slice) cut along each nerve shown by the axial view, which was scanned at the angle of 105 degrees taken between the dorsal line of the brain stem and the line corresponding to the pontmedullary junction. The rate of correspondence between the OS-GR images and the intraoperative findings was 80% in the TN's and 89% in the HFS's. In all these OS-GR images, the vascular compressions of the REZ of the trigeminal or facial nerve were well visualized as curvilinear high-intensity lines and/or spots. Furthermore, the relationship between the vascular compressions and nerves could be foreseen preoperatively in 40% of the TN's and in 55.6% of the HFS's. It is concluded that OS-GR images obtained by means of MRI may serve as useful planning aids prior to microvascular decompression for cases of TN and HFS because of the corresponding operative view along the approach. (author).

  18. Prone and supine percutaneous nephrolithotomy.

    Science.gov (United States)

    Lucarelli, G; Breda, A

    2013-06-01

    Since the first successful stone extraction through a nephrostomy in 1976, percutaneous nephrolithotomy (PCNL) has became the preferred procedure especially for treatment of large, complex and staghorn calculi. For decades this method has been performed with the patient in the prone position. More recently, particular interest has been taken on supine PCNL due to less anestesiological risks and the possibility of simultaneous anterograde and retrograde access to the whole urinary tract. Although many retrospective studies have been published, only two prospective trials comparing the two positions are reported in the literature. The best access to PCNL represents still a controversial issue. The overall experience reported in literature indicates that each modality is equally feasible and safe. Therefore, to date the surgeon's preference is the prime indication to one access over the other.

  19. An Analysis of Obliqueness in English Writing in Views of Cognitive Process and Theme/Rheme%英语写作中间接性言语特征分析

    Institute of Scientific and Technical Information of China (English)

    李丽

    2014-01-01

    在英语写作中,当要求用某一领域的知识来作答时,学生往往会复制内容信息,而不是重新建构知识来回答,这就是间接性言语行为。写作认知分析表明,问题与回答的不一致是由于思维活动中任务说明和修辞目标设定的局限性;而学生把问题看成是资料叙述,所以写作是受基于内容和语句的目标所驱动。从写作认知理论和Haliday功能语法主/述位概念两个角度分析学生间接言语行为,有助于了解学生的写作认知过程,同时对英语课堂写作教学有实践指导意义。%In writing, when required to use knowledge in a given context to fulfill a task, many student writers tend to copy the original content instead of restructuring it to answer the focal demand of the question. This is an oblique answer. This paper analyses obliqueness as a writing problem in views of cognitive process theory and Halliday's functional grammar, using from the concepts of Theme / Rheme. A cognitive study of oblique answers in writing suggests that the lack of fitness between answer and question arises from limitations in the mental processes of task interpretation and rhetorical goal setting. The student writer interprets the task as an information recount task, and therefore the writing is driven by goals that are essentially content- and sentence-based. A theme/Rheme analysis of obliqueness reveals that inappropriate choice of information for Theme contributes towards the difference between an oblique answer and question. Analyzing obliqueness in students' writing from in views of cognitive process and Theme/Rheme un-covers insights into students'composing processes that have implications for the practical writing classroom.

  20. WHAT IS THE BEST RADIOGRAPHIC VIEW FOR "DIE PUNCH" DISTAL RADIUS FRACTURES? A CADAVER MODEL STUDY.

    Science.gov (United States)

    Falcochio, Diego Figueira; Crepaldi, Bruno Eiras; Trindade, Christiano Augusto; da Costa, Antonio Carlos; Chakkour, Ivan

    2012-01-01

    the aim of this study is try to show the best view for distal radius fractures so called die-punch fractures. There has been used a human cadaver radius bone from the Salvador Arena Tissue Bank. This bone was cleaned up after removing the soft tissues and osteotomies created displaced lunate fossa fractures of 0, 1, 2, 3 and 5 mm. We have fixed this fragment with adhesive tape. Then the joint deviation were significantly increased with step-offs of 1 mm. Radiographs were then taken into 5 different positions: postero-anterior view, lateral view, oblique views and tangencial view for each of the deviations. The resulting lunate fossa depression in each X-ray film was analyzed by the AutoCAD 2010® software. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees.

  1. Reliability of a new supination resistance measurement device and validation of the manual supination resistance test.

    Science.gov (United States)

    Griffiths, Ian B; McEwan, Islay M

    2012-01-01

    Kinematic observations are inconsistent in predicting lower-extremity injury risk, and research suggests that kinetic variables may be more important in this regard. Before kinetics can be prospectively investigated, we need reliable ways of measuring them clinically. A measurement instrument was manufactured that closely mirrors a manual test used to clinically estimate supination resistance force. The reliability of the instrument and the validity of the clinical test were investigated. The left feet of 26 healthy individuals (17 men and 9 women; mean ± SD age, 25.9 ± 9.2 years; mean ± SD weight, 77.7 ± 13.3 kg) were assessed. Foot Posture Index (FPI-6), manual supination resistance, and machine supination resistance were measured. Intrarater and interrater reliability of all of the measurements were calculated. Correlations of the supination resistance measured by the device with FPI-6, the manual supination resistance test, and body weight were investigated. Interrater reliability of all of the measurements was generally poor. The supination resistance machine correlated highly with the manual supination test for the rater experienced with its use. Supination resistance measurements correlated poorly with the FPI-6 and weakly with body weight. The supination resistance machine was shown to have sufficient limits of agreement for the study, but improvements need to be made for more meaningful research going forward. In this study, the force required to supinate a foot was independent of its posture, and approximately 12% of it was explained by body weight. Further work is required with a much larger sample size to build regression models that sufficiently predict supination resistance force and that will be of clinical use. The manual supination test is a valid clinical test for clinicians experienced in its use.

  2. Comparison of Muscle Activities Using a Pressure Biofeedback Unit during Abdominal Muscle Training Performed by Normal Adults in the Standing and Supine Positions.

    Science.gov (United States)

    Jung, Da-Eun; Kim, Kyoung; Lee, Su-Kyoung

    2014-02-01

    [Purpose] The purpose of this study was to assess the effects of draw-in exercise on abdominal muscle activity in the standing and supine positions. [Methods] Twenty healthy women participated in this study. The subjects were required to complete two draw-in exercises (standing and supine positions) using a biofeedback pressure unit. The root mean square (RMS) values of the EMG data were expressed as a percentage of the resting contraction. The data were analyzed using the independent t-test. [Results] According to the changes in the activities of the abdominal muscles, the draw-in exercise in the standing position produced the most significant increase in the activities of the rectus abdominis, the transverse abdominis, the internal oblique, and the external oblique muscles. [Conclusion] The activities of the trunk stability muscles (rectus abdominis, transverse abdominis, internal oblique, and external oblique) increased more in the standing than in the supine position, enabling the subjects to overcome gravity. Therefore, to strengthen the activation of the abdominal muscles, a standing position seems to be more effective than a supine position for draw-in exercises.

  3. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  4. Superior oblique surgery: when and how?

    Directory of Open Access Journals (Sweden)

    Taylan Şekeroğlu H

    2013-08-01

    Full Text Available Hande Taylan Şekeroğlu,1 Ali Sefik Sanac,1 Umut Arslan,2 Emin Cumhur Sener11Department of Ophthalmology, 2Department of Biostatistics, Hacettepe University Faculty of Medicine, Ankara, TurkeyBackground: The purpose of this paper is to review different types of superior oblique muscle surgeries, to describe the main areas in clinical practice where superior oblique surgery is required or preferred, and to discuss the preferred types of superior oblique surgery with respect to their clinical outcomes.Methods: A consecutive nonrandomized retrospective series of patients who had undergone superior oblique muscle surgery as a single procedure were enrolled in the study. The diagnosis, clinical features, preoperative and postoperative vertical deviations in primary position, type of surgery, complications, and clinical outcomes were reviewed. The primary outcome measures were the type of strabismus and the type of superior oblique muscle surgery. The secondary outcome measure was the results of the surgeries.Results: The review identified 40 (20 male, 20 female patients with a median age of 6 (2–45 years. Nineteen patients (47.5% had Brown syndrome, eleven (27.5% had fourth nerve palsy, and ten (25.0% had horizontal deviations with A pattern. The most commonly performed surgery was superior oblique tenotomy in 29 (72.5% patients followed by superior oblique tuck in eleven (27.5% patients. The amount of vertical deviation in the fourth nerve palsy and Brown syndrome groups (P = 0.01 for both and the amount of A pattern in the A pattern group were significantly reduced postoperatively (P = 0.02.Conclusion: Surgery for the superior oblique muscle requires experience and appropriate preoperative evaluation in view of its challenging nature. The main indications are Brown syndrome, fourth nerve palsy, and A pattern deviations. Superior oblique surgery may be effective in terms of pattern collapse and correction of vertical deviations in primary

  5. On the Oblique Intergovernmental Tax Competition From the View of Finance and Tax Law%府际税收竞争的财税法审思

    Institute of Scientific and Technical Information of China (English)

    吕铖钢

    2016-01-01

    府际管理以多方参与为特征,以互动博弈为手段,以区域利益最大化为目标,是政府关系梳理的有效范式。府际治理作为解释政府政策与行为的一种分析方法,以问题解决为导向,是政府组织重塑、政府政策革新、政府行为再造的风向标。以府际关系为理论分析范式可将税收竞争分为纵向府际税收竞争、横向府际税收竞争、斜向府际税收竞争和跨域府际税收竞争。通过理论考察与实践解析探明府际关系的规律,明晰府际税收竞争的原因、方式与路径,认为地方财政能力的提升不仅应重点关注静态的制度调整,还应将动态的税收竞争纳入分析范围,并提出以区域合作机制重塑府际税收竞争模式,以财税法律规范府际税收竞争行为,以公私合作制消弭有害税收竞争动机。%Featured by multiple participations, intergovernmental management takes interactive game as the method and the region maximum benefit as the goal, which is an effective way to regulate the intergovernmental relationship. Intergovernmental governance is a problem solving oriented method to explain the behavior of the government, which can reshape government organization, innovate the government policy and reinvent the government practice. From the perspective of intergovernmental relationships, tax competition includes horizontal competition, vertical competition, oblique competition and boundary⁃spanning competition. This paper illuminated the rules of intergovernmental relationships through theoretical investigation and practical analysis. Besides static adjustment of system only, tax competition should be noted too. The regional cooperation mechanism can reshape the mode of intergovernmental tax competition, finance and tax law can regulate the behavior of intergovernmental tax competition, public and private partnership can eliminate the motive of harmful tax competition.

  6. Inferring Planetary Obliquity Using Rotational & Orbital Photometry

    CERN Document Server

    Schwartz, Joel C; Haggard, Hal M; Pallé, Eric; Cowan, Nicolas B

    2015-01-01

    The obliquity of a terrestrial planet is an important clue about its formation and critical to its climate. Previous studies using simulated photometry of Earth show that continuous observations over most of a planet's orbit can be inverted to infer obliquity. We extend this approach to single-epoch observations for planets with arbitrary albedo maps. For diffuse reflection, the flux seen by a distant observer is the product of the planet's albedo map, the host star's illumination, and the observer's visibility of different planet regions. It is useful to treat the product of illumination and visibility as the kernel of a convolution; this kernel is unimodal and symmetric. For planets with unknown obliquity, the kernel is not known a priori, but could be inferred by fitting a rotational light curve. We analyze this kernel under different viewing geometries, finding it well described by its longitudinal width and latitudinal position. We use Monte Carlo simulation to estimate uncertainties on these kernel char...

  7. Mars Obliquity Cycle Illustration

    Science.gov (United States)

    2008-01-01

    The tilt of Mars' spin axis (obliquity) varies cyclically over hundreds of thousands of years, and affects the sunlight falling on the poles. Because the landing site of NASA's Phoenix Mars Lander is so near the north pole, higher sun and warmer temperatures during high obliquity lead to warmer, more humid surface environments, and perhaps thicker, more liquid-like films of water in soil. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. Cervical traction. A comparison of sitting and supine positions.

    Science.gov (United States)

    Deets, D; Hands, K L; Hopp, S S

    1977-03-01

    Eight students were studied todetermine the position which provided the greatest amount of posterior intervertebral separation during a cervical traction treatment. A standard angle of 45 degrees with traction apparatus set at zero, 14 Kg (30 pounds), and 18 Kg (40 pounds) were used in both sitting and supine positions. Measurements of posterior intervertebral separation taken from lateral roentgenograms of the C4-C7 vertebrae revealed greater separation in the supine positions. The results suggested that the supine position was more beneficial in treatment of the cervical spine with traction. The investigators concluded that the increased separation in the supine position was related to the patient's increased comfort and relaxation.

  9. Climates of Oblique Exoplanets

    Science.gov (United States)

    Dobrovolskis, A. R.

    2008-12-01

    A previous paper (Dobrovolskis 2007; Icarus 192, 1-23) showed that eccentricity can have profound effects on the climate, habitability, and detectability of extrasolar planets. This complementary study shows that obliquity can have comparable effects. The known exoplanets exhibit a wide range of orbital eccentricities, but those within several million km of their suns are generally in near-circular orbits. This fact is widely attributed to the dissipation of tides in the planets, which is particularly effective for solid/liquid bodies like "Super-Earths". Along with friction between a solid mantle and a liquid core, tides also are expected to despin a planet until it is captured in the synchronous resonance, so that its rotation period is identical to its orbital period. The canonical example of synchronous spin is the way that our Moon always keeps nearly the same hemisphere facing the Earth. Tides also tend to reduce the planet's obliquity (the angle between its spin and orbital angular velocities). However, orbit precession can cause the rotation to become locked in a "Cassini state", where it retains a nearly constant non-zero obliquity. For example, our Moon maintains an obliquity of about 6.7° with respect to its orbit about the Earth. For comparison, stable Cassini states can exist for practically any obliquity up to 180° for planets of binary stars, or in multi-planet systems with high mutual inclinations, such as are produced by scattering or by the Kozai mechanism. This work considers planets in synchronous rotation with circular orbits. For obliquities greater than 90°, the ground track of the sub-solar point wraps around all longitudes on the surface of such a planet. For smaller obliquities, the sub-solar track takes the figure-8 shape of an analemma. This can be visualized as the intersection of the planet's spherical surface with a right circular cylinder, parallel to the spin axis and tangent to the equator from the inside. The excursion of the

  10. Oblique Axis Body Fracture

    DEFF Research Database (Denmark)

    Takai, Hirokazu; Konstantinidis, Lukas; Schmal, Hagen

    2016-01-01

    Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced...... Anderson type III fractures with a characteristic fracture pattern that we refer to as "oblique type axis body fracture." Results. The female patients aged 90 and 72 years, respectively, were both diagnosed with minimally displaced Anderson type III fractures. Both fractures had a characteristic "oblique...... type" fracture pattern. The first patient was treated conservatively with cervical spine immobilization in a semirigid collar. However, gross displacement was noted at the 6-week follow-up visit. The second patient was therefore treated operatively by C1-C3/4 posterior fusion and the course...

  11. Oblique Axis Body Fracture

    DEFF Research Database (Denmark)

    Takai, Hirokazu; Konstantinidis, Lukas; Schmal, Hagen;

    2016-01-01

    was uneventful. Conclusions. Oblique type axis body fractures resemble a highly unstable subtype of Anderson type III fractures with the potential of severe secondary deformity following conservative treatment, irrespective of initial grade of displacement. The authors therefore warrant a high index of suspicion......Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced...

  12. Orientation Strategies for Aerial Oblique Images

    Science.gov (United States)

    Wiedemann, A.; Moré, J.

    2012-07-01

    Oblique aerial images become more and more distributed to fill the gap between vertical aerial images and mobile mapping systems. Different systems are on the market. For some applications, like texture mapping, precise orientation data are required. One point is the stable interior orientation, which can be achieved by stable camera systems, the other a precise exterior orientation. A sufficient exterior orientation can be achieved by a large effort in direct sensor orientation, whereas minor errors in the angles have a larger effect than in vertical imagery. The more appropriate approach is by determine the precise orientation parameters by photogrammetric methods using an adapted aerial triangulation. Due to the different points of view towards the object the traditional aerotriangulation matching tools fail, as they produce a bunch of blunders and require a lot of manual work to achieve a sufficient solution. In this paper some approaches are discussed and results are presented for the most promising approaches. We describe a single step approach with an aerotriangulation using all available images; a two step approach with an aerotriangulation only of the vertical images plus a mathematical transformation of the oblique images using the oblique cameras excentricity; and finally the extended functional model for a bundle block adjustment considering the mechanical connection between vertical and oblique images. Beside accuracy also other aspects like efficiency and required manual work have to be considered.

  13. The obliquity of Enceladus

    CERN Document Server

    Baland, Rose-Marie; Van Hoolst, Tim

    2015-01-01

    The extraordinary activity at Enceladus' warm south pole indicates the presence of an internal global or local reservoir of liquid water beneath the surface. While Tyler (2009, 2011) has suggested that the geological activity and the large heat flow of Enceladus could result from tidal heating triggered by a large obliquity of at least 0.05{\\deg}-0.1{\\deg}, theoretical models of the Cassini state predict the obliquity to be two to three orders of magnitude smaller for an entirely solid and rigid Enceladus. We investigate the influence of an internal subsurface ocean and of tidal deformations of the solid layers on the obliquity of Enceladus. Our Cassini state model takes into account the external torque exerted by Saturn on each layer of the satellite and the internal gravitational and pressure torques induced by the presence of the liquid layer. As a new feature, our model also includes additional torques that arise because of the periodic tides experienced by the satellite. We find that the upper limit for ...

  14. Oblique lumbar spine radiographs: importance in young patients

    Energy Technology Data Exchange (ETDEWEB)

    Libson, E.; Bloom, R.A.; Dinari, G.; Robin, G.C.

    1984-04-01

    Spondylolysis is a direct precursor of spondylolisthesis and can lead to crippling back pain. Of 1,743 patients surveyed, including 936 who were asymptomatic and 807 with back pain, 165 (including 91 who were asymptomatic and 74 with back pain) had spondylolysis, which was seen only on oblique lumbar views in 20% of cases. Because of the high false-negative rate of AP and lateral views, oblique views are essential in children and young adults. As spondylolysis is rare above L3, radiographs can be limited to L3-S1. Significantly less spondylolysis was seen in persons older than 30 with back pain usually caused by disk degeneration.

  15. Kinetic analysis of supine stepping for early rehabilitation of walking.

    Science.gov (United States)

    Fang, Juan; Galen, Sujay; Vuckovic, Aleksandra; Conway, Bernard A; Hunt, Kenneth J

    2014-05-01

    In order to promote gait restoration in patients who cannot maintain an upright position in the early post-injury phase, a Gait Orthosis for Early Rehabilitation was proposed for supine stepping. Although supine stepping can generate lower-limb joint trajectories which are close to normal gait, the inter-segmental dynamics of supine stepping are believed to be different from those of upright walking. Furthermore, training in a supine position requires a certain loading on the foot to mimic the ground reaction forces, where different loading amplitudes influence the joint dynamics. This work analysed the kinetics of supine stepping with variable loading and investigated structural modifications for the Gait Orthosis for Early Rehabilitation system to address this kinetic difference. Three able-bodied subjects walked overground while their walking performance was recorded. Based on the experimental data, a leg-linkage model was developed to simulate the dynamics of upright walking. This model was then rotated by 90° with different foot loadings to investigate the kinetics of supine stepping. Compared to upright walking, supine stepping had a large kinetic difference at the hip joint due to the supine leg position. The ankle joint during supine stepping was sensitive to the force amplitude simulated on the foot. Thus, the Gait Orthosis for Early Rehabilitation system requires a leg frame to compensate the position change and a shoe platform to activate the leg muscles, especially at the ankle joint. This study provided important structural information for the further development of the Gait Orthosis for Early Rehabilitation system.

  16. Use of Vertical Aerial Images for Semi-Oblique Mapping

    Science.gov (United States)

    Poli, D.; Moe, K.; Legat, K.; Toschi, I.; Lago, F.; Remondino, F.

    2017-05-01

    The paper proposes a methodology for the use of the oblique sections of images from large-format photogrammetric cameras, by exploiting the effect of the central perspective geometry in the lateral parts of the nadir images ("semi-oblique" images). The point of origin of the investigation was the execution of a photogrammetric flight over Norcia (Italy), which was seriously damaged after the earthquake of 30/10/2016. Contrary to the original plan of oblique acquisitions, the flight was executed on 15/11/2017 using an UltraCam Eagle camera with focal length 80 mm, and combining two flight plans, rotated by 90º ("crisscross" flight). The images (GSD 5 cm) were used to extract a 2.5D DSM cloud, sampled to a XY-grid size of 2 GSD, a 3D point clouds with a mean spatial resolution of 1 GSD and a 3D mesh model at a resolution of 10 cm of the historic centre of Norcia for a quantitative assessment of the damages. From the acquired nadir images the "semi-oblique" images (forward, backward, left and right views) could be extracted and processed in a modified version of GEOBLY software for measurements and restitution purposes. The potential of such semi-oblique image acquisitions from nadir-view cameras is hereafter shown and commented.

  17. Oblique dust density waves

    Science.gov (United States)

    Piel, Alexander; Arp, Oliver; Menzel, Kristoffer; Klindworth, Markus

    2007-11-01

    We report on experimental observations of dust density waves in a complex (dusty) plasma under microgravity. The plasma is produced in a radio-frequency parallel-plate discharge (argon, p=15Pa, U=65Vpp). Different sizes of dust particles were used (3.4 μm and 6.4μm diameter). The low-frequency (f 11Hz) dust density waves are naturally unstable modes, which are driven by the ion flow in the plasma. Surprisingly, the wave propagation direction is aligned with the ion flow direction in the bulk plasma but becomes oblique at the boundary of the dust cloud with an inclination of 60^o with respect to the plasma boundary. The experimental results are compared with a kinetic model in the electrostatic approximation [1] and a fluid model [2]. Moreover, the role of dust surface waves is discussed. [1] M. Rosenberg, J. Vac. Sci. Technol. A 14, 631 (1996) [2] A. Piel et al, Phys. Rev. Lett. 97, 205009 (2006)

  18. The Comparison of Mallampati Test in Supine and Sitting Position in Traditional Approach and During Phonation for Predicting of Difficult Laryngoscopy and Intubation

    Directory of Open Access Journals (Sweden)

    A Meysamie

    2012-09-01

    Full Text Available Background: Inadequate ventilation, esophageal intubation and difficult intubation are the most common adverse respiratory outcomes in patient undergoing anesthesia .The aim of this study was to compare Mallampati test in supine and sitting positions in traditional approach and during phonation for predicting difficult laryngoscopy and intubation. Methods: In this study performed in Imam Khomeini Hospital in Tehran, Iran, Mallampati test was performed on 661 patients who met the inclusion criteria for the study. The test was done in supine and sitting positions with and without phonation by a rater who was blind to Mallampati test. Subsequently, laryngoscopy view and difficult intubation were evaluated in the four aforesaid positions by Mallampati test for predicting difficult laryngoscopy and intubation. For each situations, sensitivity, specificity, positive and negative predictive values and accuracy were calculated.Results: Overall, 28 (4.2% patients had difficult laryngoscopy and 9 (1.4% patients had difficult intubation. The highest sensitivity for Mallampati test in predicting difficult laryngoscopy and intubation was in supine and sitting positions without phonation, and the highest specificity was seen in sitting position with phonation. Negative predictive values were more than 95% in all different positions for Mallampati tests and the highest positive predictive value was seen in supine position with phonation.Conclusion: According to our findings, the highest correlation between Mallampati test and different positions in predicting difficult laryngoscopy and intubation was seen in supine position with phonation. Phonation improved Mallampati score in supine rather than sitting position.

  19. Classical Aberration And Obliquation

    CERN Document Server

    Adewole, A I A

    2002-01-01

    This is the first of several monographs to be devoted to the optics of accelerated systems. They are being published for the benefit of those who may wish to have another way of looking at kineoptical problems, and also to demonstrate that the laws of optics are unwavering in their support of the view that extragalactic redshifts need not be velocity doppler shifts nor cosmological recession shifts. In the latter context the first few monographs of the series may be viewed as providing a basis for the demonstration to be given in a latter monograph.

  20. Effect of supine exercise on platelet aggregation and fibrinolytic activity

    DEFF Research Database (Denmark)

    Dag, B; Fornitz, Gitte Gleerup; Bak, A M

    1994-01-01

    In 12 healthy young men, strenuous cycling exercise in the supine position, caused platelet aggregability to decrease and the ADP threshold to rise from 7.0 microM resting, to 9.5 exercising (P ... from 178 to 68 min, PAI-1 fell from 8.91 to 5.16 IU ml-1, and t-PA rose from 0.56 to 3.95 IU ml-1, all three values were significant to P exercise, it did not increase platelet activity as expected, but caused a modest increase...... of fibrinolytic activity. These results suggest that supine exercise will not affect the haemostatic system adversely....

  1. Oblique Points of Entry

    OpenAIRE

    Rogoff, Irit

    2015-01-01

    Contemporary Art from the Middle East: Regional Interactions with Global Art Discourses: Volume 18.\\ud How is home-grown contemporary art viewed within the Middle East? And is it understood differently outside the region? What is liable to be lost when contemporary art from the Middle East is 'transferred' to international contexts - and how can it be reclaimed? This timely book tackles ongoing questions about how 'local' perspectives on contemporary art from the Middle East are defined and h...

  2. Secular obliquity variations for Ceres

    Science.gov (United States)

    Bills, Bruce; Scott, Bryan R.; Nimmo, Francis

    2016-10-01

    We have constructed secular variation models for the orbit and spin poles of the asteroid (1) Ceres, and used them to examine how the obliquity, or angular separation between spin and orbit poles, varies over a time span of several million years. The current obliquity is 4.3 degrees, which means that there are some regions near the poles which do not receive any direct Sunlight. The Dawn mission has provided an improved estimate of the spin pole orientation, and of the low degree gravity field. That allows us to estimate the rate at which the spin pole precesses about the instantaneous orbit pole.The orbit of Ceres is secularly perturbed by the planets, with Jupiter's influence dominating. The current inclination of the orbit plane, relative to the ecliptic, is 10.6 degrees. However, it varies between 7.27 and 11.78 degrees, with dominant periods of 22.1 and 39.6 kyr. The spin pole precession rate parameter has a period of 205 kyr, with current uncertainty of 3%, dominated by uncertainty in the mean moment of inertia of Ceres.The obliquity varies, with a dominant period of 24.5 kyr, with maximum values near 26 degrees, and minimum values somewhat less than the present value. Ceres is currently near to a minimum of its secular obliquity variations.The near-surface thermal environment thus has at least 3 important time scales: diurnal (9.07 hours), annual (4.60 years), and obliquity cycle (24.5 kyr). The annual thermal wave likely only penetrates a few meters, but the much long thermal wave associated with the obliquity cycle has a skin depth larger by a factor of 70 or so, depending upon thermal properties in the subsurface.

  3. Foot and ankle fractures at the supination line

    NARCIS (Netherlands)

    T. Schepers (Tim); E.M. van Schie- van der Weert; M.R. de Vries (Mark); M. van der Elst (Maarten)

    2011-01-01

    textabstractBackground: The supination line is a fictive line along the foot and ankle, on which over twenty fracture types and approximately ten different ligamentous sprain-injuries have been identified. Objective: The current study was conducted to evaluate the incidence of different types of

  4. Supine posture inhibits cortical activity: Evidence from Delta and Alpha EEG bands.

    Science.gov (United States)

    Spironelli, Chiara; Busenello, Jessica; Angrilli, Alessandro

    2016-08-01

    Past studies have shown consistent evidence that body position significantly affects brain activity, revealing that both head-down and horizontal bed-rest are associated with cortical inhibition and altered perceptual and cognitive processing. The present study investigates the effects of body position on spontaneous, open-eyes, resting-state EEG cortical activity in 32 young women randomly assigned to one of two conditions, seated position (SP) or horizontal bed rest (BR). A between-group repeated-measure experimental design was used, EEG recordings were made from 38 scalp locations, and low-frequency (delta and alpha) amplitudes of the two groups were compared in four different conditions: when both groups (a) were seated (T0), (b) assumed two different body positions (seated vs. supine conditions, immediate [T1] and 120min later [T2]), and (c) were seated again (T3). Overall, the results showed no a priori between-group differences (T0) before experimental manipulation. As expected, delta amplitude, an index of cortical inhibition in awake resting participants, was significantly increased in group BR, revealing both rapid (T1) and mid-term (T2) inhibitory effects of supine or horizontal positions. Instead, the alpha band was highly sensitive to postural transitions, perhaps due to baroreceptor intervention and, unlike the delta band, underwent habituation and decreased after a 2-h bed rest. These results indicate clear-cut differences at rest between the seated and supine positions, thus supporting the view that the role of body position in the differences found between brain metabolic methods (fMRI and PET) in which participants lie horizontally, and EEG-MEG-TMS techniques with participants in a seated position, has been largely underestimated so far.

  5. On the Tidal Dissipation of Obliquity

    CERN Document Server

    Rogers, T M

    2013-01-01

    We investigate tidal dissipation of obliquity in hot Jupiters. Assuming an initial random orientation of obliquity and parameters relevant to the observed population, the obliquity of hot Jupiters does not evolve to purely aligned systems. In fact, the obliquity evolves to either prograde, retrograde or 90^{o} orbits where the torque due to tidal perturbations vanishes. This distribution is incompatible with observations which show that hot jupiters around cool stars are generally aligned. This calls into question the viability of tidal dissipation as the mechanism for obliquity alignment of hot Jupiters around cool stars.

  6. Biomechanics of pronation and supination of the forearm.

    Science.gov (United States)

    Kapandji, A

    2001-02-01

    Pronation-supination, the rotation of the forearm around its longitudinal axis, is an important motion because it allows the hand to be oriented, allowing one to take food and carry it to the mouth, perform personal hygiene, and live autonomously. The motion depends on the integrity of two bones, the radius and the ulna, as well as joints, ligaments, and muscles. In every pathological case, as described in this article, the anatomical features must be restored for normal function.

  7. Comparison of Upright Gait with Supine Bungee-Cord Gait

    Science.gov (United States)

    Boda, Wanda L.; Hargens, Alan R.; Campbell, J. A.; Yang, C.; Holton, Emily M. (Technical Monitor)

    1998-01-01

    Running on a treadmill with bungee-cord resistance is currently used on the Russian space station MIR as a countermeasure for the loss of bone and muscular strength which occurs during spaceflight. However, it is unknown whether ground reaction force (GRF) at the feet using bungee-cord resistance is similar to that which occurs during upright walking and running on Earth. We hypothesized-that the DRAMs generated during upright walking and running are greater than the DRAMs generated during supine bungee-cord gait. Eleven healthy subjects walked (4.8 +/- 0.13 km/h, mean +/- SE) and ran (9.1 +/- 0.51 km/h) during upright and supine bungee-cord exercise on an active treadmill. Subjects exercised for 3 min in each condition using a resistance of 1 body weight calibrated during an initial, stationary standing position. Data were sampled at a frequency of 500Hz and the mean of 3 trials was analyzed for each condition. A repeated measures analysis of variance tested significance between the conditions. Peak DRAMs during upright walking were significantly greater (1084.9 +/- 111.4 N) than during supine bungee-cord walking (770.3 +/- 59.8 N; p less than 0.05). Peak GRFs were also significantly greater for upright running (1548.3 +/- 135.4 N) than for supine bungee-cord running (1099.5 +/- 158.46 N). Analysis of GRF curves indicated that forces decreased throughout the stance phase for bungee-cord gait but not during upright gait. These results indicate that bungee-cord exercise may not create sufficient loads at the feet to counteract the loss of bone and muscular strength that occurs during long-duration exposure to microgravity.

  8. Habitable Climates: The Influence of Obliquity

    CERN Document Server

    Spiegel, David S; Scharf, Caleb A

    2008-01-01

    Without the stabilizing influence of the Moon, the Earth's obliquity could vary significantly. Extrasolar terrestrial planets with the potential to host life may therefore have large obliquities or be subject to strong obliquity variations. We revisit the habitability of oblique planets with an energy balance climate model (EBM) allowing for dynamical transitions to ice-covered snowball states as a result of ice-albedo feedback. Despite the great simplicity of our EBM, it captures reasonably well the seasonal cycle of global energetic fluxes at Earth's surface. It also performs satisfactorily against a full-physics climate model of a highly oblique Earth, in an unusual regime of circulation dominated by heat transport from the poles to the equator. Climates on oblique terrestrial planets can violate global radiative balance through much of their seasonal cycle, which limits the usefulness of simple radiative equilibrium arguments. High obliquity planets have severe climates, with large amplitude seasonal vari...

  9. ACCURACY OF MEASUREMENTS IN OBLIQUE AERIAL IMAGES FOR URBAN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    W. Ostrowski

    2016-10-01

    Full Text Available Oblique aerial images have been a source of data for urban areas for several years. However, the accuracy of measurements in oblique images during this time has been limited to a single meter due to the use of direct -georeferencing technology and the underlying digital elevation model. Therefore, oblique images have been used mostly for visualization purposes. This situation changed in recent years as new methods, which allowed for a higher accuracy of exterior orientation, were developed. Current developments include the process of determining exterior orientation and the previous but still crucial process of tie point extraction. Progress in this area was shown in the ISPRS/EUROSDR Benchmark on Multi-Platform Photogrammetry and is also noticeable in the growing interest in the use of this kind of imagery. The higher level of accuracy in the orientation of oblique aerial images that has become possible in the last few years should result in a higher level of accuracy in the measurements of these types of images. The main goal of this research was to set and empirically verify the accuracy of measurements in oblique aerial images. The research focused on photogrammetric measurements composed of many images, which use a high overlap within an oblique dataset and different view angles. During the experiments, two series of images of urban areas were used. Both were captured using five DigiCam cameras in a Maltese cross configuration. The tilt angles of the oblique cameras were 45 degrees, and the position of the cameras during flight used a high grade GPS/INS navigation system. The orientation of the images was set using the Pix4D Mapper Pro software with both measurements of the in-flight camera position and the ground control points (measured with GPS RTK technology. To control the accuracy, check points were used (which were also measured with GPS RTK technology. As reference data for the whole study, an area of the city-based map was used

  10. Accuracy of Measurements in Oblique Aerial Images for Urban Environment

    Science.gov (United States)

    Ostrowski, W.

    2016-10-01

    Oblique aerial images have been a source of data for urban areas for several years. However, the accuracy of measurements in oblique images during this time has been limited to a single meter due to the use of direct -georeferencing technology and the underlying digital elevation model. Therefore, oblique images have been used mostly for visualization purposes. This situation changed in recent years as new methods, which allowed for a higher accuracy of exterior orientation, were developed. Current developments include the process of determining exterior orientation and the previous but still crucial process of tie point extraction. Progress in this area was shown in the ISPRS/EUROSDR Benchmark on Multi-Platform Photogrammetry and is also noticeable in the growing interest in the use of this kind of imagery. The higher level of accuracy in the orientation of oblique aerial images that has become possible in the last few years should result in a higher level of accuracy in the measurements of these types of images. The main goal of this research was to set and empirically verify the accuracy of measurements in oblique aerial images. The research focused on photogrammetric measurements composed of many images, which use a high overlap within an oblique dataset and different view angles. During the experiments, two series of images of urban areas were used. Both were captured using five DigiCam cameras in a Maltese cross configuration. The tilt angles of the oblique cameras were 45 degrees, and the position of the cameras during flight used a high grade GPS/INS navigation system. The orientation of the images was set using the Pix4D Mapper Pro software with both measurements of the in-flight camera position and the ground control points (measured with GPS RTK technology). To control the accuracy, check points were used (which were also measured with GPS RTK technology). As reference data for the whole study, an area of the city-based map was used. The archived results

  11. Momentum transfer from oblique impacts

    Science.gov (United States)

    Schultz, Peter H.; Gault, Donald E.

    1987-05-01

    A completely satisfactory experiment would be in a low gravity environment where the effect of momentum imparted by ejecta impacting the surface can be removed or controlled from momentum transfer during impact. Preliminary estimates can be made using a ballistic pendulum. Such experiments were initiated at the NASA-Ames Vertical Gun Range in order to examine momentum transfer due to impact vaporization for oblique impacts. The preliminary results indicate that momentum from oblique impacts is very inefficient: decreasing with increasing impact velocity and perhaps size; increasing with decreasing density; and increasing with increasing impact angle. At face value, such results minimize the effect of momentum transfer by grazing impact; the more probable impact angles of 30 deg would have a greater effect, contrary to the commonly held impression.

  12. Anaglyph videoanimations from oblique stereoimages

    Science.gov (United States)

    Vozenilek, Vit; Kralik, Tomas

    2015-03-01

    The paper deals with the approach of compiling of animations from a pair of oblique stereoimages. The authors investigated as simple and cheap way as possible to develop such approach which will be available for wide scope of ordinary users with common equipment. They concentrated on three procedures of oblique stereoimage handling to compile sets of images, animations and analogue documents. After capturing construction site by a pair of web cameras the data were corrected, photogrammetrically adjusted (due to radial distortion) and exported. Firstly, a set of anaglyphic images were compiled, then they were trimmed and timeline was inserted. The final anaglyph animations are compiled in various versions. In addition, an anaglyphic book containing 150 images was created in a special way that the user can easily browse through its content. The main outputs are several unique anaglyph products, but more beneficial outputs are developed procedures of anaglyph visualization that can be applied with minor modifications to photographing of any objects.

  13. Analyzing RCD30 Oblique Performance in a Production Environment

    Science.gov (United States)

    Soler, M. E.; Kornus, W.; Magariños, A.; Pla, M.

    2016-06-01

    In 2014 the Institut Cartogràfic i Geològic de Catalunya (ICGC) decided to incorporate digital oblique imagery in its portfolio in response to the growing demand for this product. The reason can be attributed to its useful applications in a wide variety of fields and, most recently, to an increasing interest in 3d modeling. The selection phase for a digital oblique camera led to the purchase of the Leica RCD30 Oblique system, an 80MPixel multispectral medium-format camera which consists of one Nadir camera and four oblique viewing cameras acquiring images at an off-Nadir angle of 35º. The system also has a multi-directional motion compensation on-board system to deliver the highest image quality. The emergence of airborne oblique cameras has run in parallel to the inclusion of computer vision algorithms into the traditional photogrammetric workflows. Such algorithms rely on having multiple views of the same area of interest and take advantage of the image redundancy for automatic feature extraction. The multiview capability is highly fostered by the use of oblique systems which capture simultaneously different points of view for each camera shot. Different companies and NMAs have started pilot projects to assess the capabilities of the 3D mesh that can be obtained using correlation techniques. Beyond a software prototyping phase, and taking into account the currently immature state of several components of the oblique imagery workflow, the ICGC has focused on deploying a real production environment with special interest on matching the performance and quality of the existing production lines based on classical Nadir images. This paper introduces different test scenarios and layouts to analyze the impact of different variables on the geometric and radiometric performance. Different variables such as flight altitude, side and forward overlap and ground control point measurements and location have been considered for the evaluation of aerial triangulation and

  14. Stability of oblique shock front

    Institute of Scientific and Technical Information of China (English)

    CHEN; Shuxing(陈恕行)

    2002-01-01

    The stability of the weak planar oblique shock front with respect to the perturbation of the wall is discussed. By the analysis of the formation and the global construction of shock and its asymptotic behaviour for stationary supersonic flow along a smooth rigid wall we obtain the stability of the solution containing a weak planar shock front. The stability can be used to single out a physically reasonable solution together with the entropy condition.

  15. Setup accuracy for prone and supine whole breast irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mulliez, Thomas; Vercauteren, Tom; Greveling, Annick van; Speleers, Bruno; Neve, Wilfried de; Veldeman, Liv [University Hospital Ghent, Department of Radiotherapy, Ghent (Belgium); Gulyban, Akos [University Hospital Ghent, Department of Radiotherapy, Ghent (Belgium); University Hospital Liege, Department of Radiotherapy, Liege (Belgium)

    2016-04-15

    To evaluate cone-beam computed tomography (CBCT) based setup accuracy and margins for prone and supine whole breast irradiation (WBI). Setup accuracy was evaluated on 3559 CBCT scans of 242 patients treated with WBI and uncertainty margins were calculated using the van Herk formula. Uni- and multivariate analysis on individual margins was performed for age, body mass index (BMI) and cup size. The population-based margin in vertical (VE), lateral (LA) and longitudinal (LO) directions was 10.4/9.4/9.4 mm for the 103 supine and 10.5/22.4/13.7 mm for the 139 prone treated patients, being significantly (p < 0.01) different for the LA and LO directions. Multivariate analysis identified a significant (p < 0.05) correlation between BMI and the LO margin in supine position and the VE/LA margin in prone position. In this series, setup accuracy is significantly worse in prone compared to supine position for the LA and LO directions. However, without proper image-guidance, uncertainty margins of about 1 cm are also necessary for supine WBI. For patients with a higher BMI, larger margins are required. (orig.) [German] Ziel der Arbeit war es, die interfraktionelle Repositionierungsgenauigkeit in Bauchlage (BL) versus Rueckenlage (RL) bei Ganzbrustbestrahlung (GBB) mittels Cone-Beam-CT (CBCT) zu bestimmen, um die notwendigen PTV-Sicherheitsabstaende zu definieren. Die Repositionierungsgenauigkeit wurde basierend an 3559 CBCT-Scans von 242 mit GBB behandelten Patienten ausgewertet. Die PTV-Sicherheitsabstaende wurden unter Verwendung der ''van-Herk''-Formel berechnet. Uni- und multivariable Analysen wurden fuer Sicherheitsabstaende in jede Richtung auf Basis von Alter, Body-Mass-Index (BMI) und Koerbchengroesse durchgefuehrt. Die basierend auf den taeglichen CBCT-Verschiebungen berechneten PTV-Sicherheitsabstaende betrugen in anteroposteriorer (AP), lateraler (LT oder links-rechts) und kraniokaudaler (CC) Richtung 10,4/9,4/9,4 mm fuer die RL (103 Patienten) und

  16. Adult Degenerative Scoliosis: Can Cobb Angle on a Supine Posteroanterior Radiograph Be Used to Predict the Cobb Angle in a Standing Position?

    Science.gov (United States)

    Yang, Changwei; Li, Yanming; Zhao, Yunfei; Zhu, Xiaodong; Li, Ming; Liu, Gabriel

    2016-02-01

    It is necessary to assess coronal Cobb angle in the diagnosis and treatment of patients with adult degenerative scoliosis (ADS). But as most ADS patients are elderly patients who are difficult or unable to stand upright without assistance, it is difficult to obtain standing posteroanterior X-ray radiographs. Whether it is possible to use Cobb angle obtained on a supine posteroanterior X-ray radiograph to predict Cobb angle in a standing position remains unanswered.To study the correlation between X-ray plain radiographic parameters obtained from the supine position and those obtained from the standing position in ADS patients.Medical records and radiological information were obtained from ADS patients prospectively. Posteroanterior X-ray views of the spine were taken in both standing and supine positions simultaneously in the same ADS patients to record information about the position of the apical and end vertebrae in the coronal position and measure Cobb angle and rotation degree of the apical vertebra. Correlation and linear regression were used to analyze the correlation between the Cobb angle and the rotation degree of the apical vertebra on the X-ray plain radiographs obtained from the standing and supine positions.Of 94 ADS patients who met the inclusion criteria, 14 (15%) patients were male and 80 (85%) patients were female who ranged in age from 41 to 92 years with a mean of 67 years. The mean Cobb angle on the supine X-ray radiographs was 21 ± 10° versus 26 ± 12° on the standing X-ray radiographs, the difference being statistically significant (P < 0.01). The rotation angle of the apical vertebra in the supine and standing positions was 1.8 ± 0.7 and 1.9 ± 0.7, respectively, the difference being statistically significant (P < 0.05). Correlation analysis showed a strong correlation in Cobb angle between the supine and standing X-ray plain radiographs (r = 0.92, P < 0.01). The correlation coefficient of the rotation of

  17. USE OF VERTICAL AERIAL IMAGES FOR SEMI-OBLIQUE MAPPING

    Directory of Open Access Journals (Sweden)

    D. Poli

    2017-05-01

    Full Text Available The paper proposes a methodology for the use of the oblique sections of images from large-format photogrammetric cameras, by exploiting the effect of the central perspective geometry in the lateral parts of the nadir images (“semi-oblique” images. The point of origin of the investigation was the execution of a photogrammetric flight over Norcia (Italy, which was seriously damaged after the earthquake of 30/10/2016. Contrary to the original plan of oblique acquisitions, the flight was executed on 15/11/2017 using an UltraCam Eagle camera with focal length 80 mm, and combining two flight plans, rotated by 90º (“crisscross” flight. The images (GSD 5 cm were used to extract a 2.5D DSM cloud, sampled to a XY-grid size of 2 GSD, a 3D point clouds with a mean spatial resolution of 1 GSD and a 3D mesh model at a resolution of 10 cm of the historic centre of Norcia for a quantitative assessment of the damages. From the acquired nadir images the “semi-oblique” images (forward, backward, left and right views could be extracted and processed in a modified version of GEOBLY software for measurements and restitution purposes. The potential of such semi-oblique image acquisitions from nadir-view cameras is hereafter shown and commented.

  18. The chaotic obliquity of Mars

    Science.gov (United States)

    Touma, Jihad; Wisdom, Jack

    1993-01-01

    The discovery (by Laskar, 1989, 1990) that the evolution of the solar system is chaotic, made in a numerical integration of the averaged secular approximation of the equations of motions for the planets, was confirmed by Sussman and Wisdom (1992) by direct numerical integration of the whole solar system. This paper presents results of direct integrations of the rotation of Mars in the chaotically evolved planetary system, made using the same model as that used by Sussman and Wisdom. The numerical integration shows that the obliquity of Mars undergoes large chaotic variations, which occur as the system evolves in the chaotic zone associated with a secular spin-orbit resonance.

  19. A biomechanical analysis of pronation-supination of the forearm using magnetic resonance imaging; Dynamic changes of the interosseous membrane of the forearm during pronation-supination

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshiyasu; Yabe, Yutaka; Horiuchi, Yukio (Keio Univ., Tokyo (Japan). School of Medicine)

    1994-01-01

    A magnetic resonance (MR) study was performed using a 0.5 tesla system to investigate the behavior of the interosseous membrane of the forearm during pronation-supination and to evaluate the influence of pronation-supination loading in the neutral position. The right forearm was examined in twenty volunteers at the proximal fourth part, middle part and distal fourth part of the forearm. Slices were examined at maximum pronation, 45deg pronation, neutral, 45deg supination and at maximum supination. A 0.1 Nm torque in both rotational directions was added in the neutral position. The MR image of the interosseous membrane of the forearm was a thin line with low contrast in the neutral position. The tendinous portion and membranous portions of the interosseous membrane could be differentiated. At maximum pronation and at maximum supination, the interosseous membrane was flexed, caused mainly by the relaxation in the membranous portion. The radius shifted slightly volarly to the ulna at maximum pronation, caused by the incongruity of the distal radioulnar joint. The radius shifted dorsally with pronation loading, and shifted volarly with supination loading. The inelasticity of the membranous portion of the interosseous membrane may be responsible for pronation-supination contracture, while rotational loading may be a cause of the distal radioulnar joint dislocation. These studies suggest that this technique is useful for further in vivo studies of kinesiology. (author).

  20. Obliquity forcing of low-latitude climate

    NARCIS (Netherlands)

    Bosmans, J.H.C.; Hilgen, F.J.; Tuenter, Erik; Lourens, L.J.

    2015-01-01

    The influence of obliquity, the tilt of the Earth's rotational axis, on incoming solar radiation at low latitudes is small, yet many tropical and subtropical palaeoclimate records reveal a clear obliquity signal. Several mechanisms have been proposed to explain this signal, such as the remote

  1. Obliquity forcing of low-latitude climate

    NARCIS (Netherlands)

    Bosmans, J.H.C.; Hilgen, F.J.; Tuenter, Erik; Lourens, L.J.

    2015-01-01

    The influence of obliquity, the tilt of the Earth's rotational axis, on incoming solar radiation at low latitudes is small, yet many tropical and subtropical palaeoclimate records reveal a clear obliquity signal. Several mechanisms have been proposed to explain this signal, such as the remote influe

  2. Clinical observation of the abnormality of inferior oblique tendon in congenital superior oblique muscle paralytic patients

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2013-11-01

    Full Text Available AIM: To measure the abnormality of the inferior oblique tendon in patients with congenital superior oblique muscle paralysis.METHODS: In this cross-sectional, self-control designed study, the tensity of the inferior oblique tendon of both the paralytic and nonparalytic eye were measured during the operations in 30 patients who were diagnosed with exotropia(including intermittent exotropia and constant exotropia accompanied with single superior oblique muscle paralysis. The tensity of the tendon was measured as the maximal distance of which the inferior oblique tendon could be lifted from the scleraRESULTS: Inferior oblique had different degrees of thickness, but was tougher and tighter than that of nonparalytic eye. There was a significant difference(PCONCLUSION: The inferior oblique tendon is stronger and less relaxant in the paralytic eyes.

  3. Microwave Imaging under Oblique Illumination

    Directory of Open Access Journals (Sweden)

    Qingyang Meng

    2016-07-01

    Full Text Available Microwave imaging based on inverse scattering problem has been attracting many interests in the microwave society. Among some major technical challenges, the ill-posed, multi-dimensional inversion algorithm and the complicated measurement setup are critical ones that prevent it from practical applications. In this paper, we experimentally investigate the performance of the subspace-based optimization method (SOM for two-dimensional objects when it was applied to a setup designed for oblique incidence. Analytical, simulation, and experimental results show that, for 2D objects, neglecting the cross-polarization scattering will not cause a notable loss of information. Our method can be potentially used in practical imaging applications for 2D-like objects, such as human limbs.

  4. Oblique Photogrammetry Supporting 3d Urban Reconstruction of Complex Scenarios

    Science.gov (United States)

    Toschi, I.; Ramos, M. M.; Nocerino, E.; Menna, F.; Remondino, F.; Moe, K.; Poli, D.; Legat, K.; Fassi, F.

    2017-05-01

    Accurate 3D city models represent an important source of geospatial information to support various "smart city" applications, such as space management, energy assessment, 3D cartography, noise and pollution mapping as well as disaster management. Even though remarkable progress has been made in recent years, there are still many open issues, especially when it comes to the 3D modelling of complex urban scenarios like historical and densely-built city centres featuring narrow streets and non-conventional building shapes. Most approaches introduce strong building priors/constraints on symmetry and roof typology that penalize urban environments having high variations of roof shapes. Furthermore, although oblique photogrammetry is rapidly maturing, the use of slanted views for façade reconstruction is not completely included in the reconstruction pipeline of state-of-the-art software. This paper aims to investigate state-of-the-art methods for 3D building modelling in complex urban scenarios with the support of oblique airborne images. A reconstruction approach based on roof primitives fitting is tested. Oblique imagery is then exploited to support the manual editing of the generated building models. At the same time, mobile mapping data are collected at cm resolution and then integrated with the aerial ones. All approaches are tested on the historical city centre of Bergamo (Italy).

  5. Isotonic and hypertonic sodium loading in supine humans

    DEFF Research Database (Denmark)

    Andersen, L J; Jensen, T U; Bestle, M H

    1999-01-01

    The hypothesis that hypertonic saline infusion induces a greater natriuresis than infusion of the same amount of sodium as isotonic saline was tested in 8 supine subjects on fixed sodium intake of 150 mmol NaCl day(-1). Sodium loads equivalent to the amount of sodium contained in 10% of measured...... extracellular volume were administered intravenously over 90 min either as isotonic saline or as hypertonic saline (850 mmol L(-1)). A third series without saline infusion served as time control. Experiments lasted 8 h. Water balance and sodium loads were maintained by replacing the excreted amounts every hour....... Plasma sodium concentrations only increased following hypertonic saline infusion (by 2.7 +/- 0.3 mmol L(-1)). Oncotic pressure decreased significantly more with isotonic saline (4.1 +/- 0.3 mmHg) than with hypertonic saline (3.2 +/- 0.2 mmHg), indicating that isotonic saline induced a stronger volumetric...

  6. Models of Warm Jupiter Atmospheres: Observable Signatures of Obliquity

    Science.gov (United States)

    Rauscher, Emily

    2017-09-01

    We present three-dimensional atmospheric circulation models of a hypothetical “warm Jupiter” planet, for a range of possible obliquities from 0° to 90°. We model a Jupiter-mass planet on a 10 day orbit around a Sun-like star, since this hypothetical planet sits at the boundary between planets for which we expect that tidal forces should have aligned their rotation axes with their orbital axes (i.e., ones with zero obliquity) and planets whose timescale for tidal alignment is longer than the typical age of an exoplanet system. In line with observational progress, which is pushing atmospheric characterization for planets on longer orbital periods, we calculate the observable signatures of obliquity for a transiting warm Jupiter: in orbital phase curves of thermal emission and in the hemispheric flux gradients that could be measured by eclipse mapping. For both of these predicted measurements, the signal that we would see depends strongly on our viewing geometry relative to the orientation of the planet’s rotation axis, and we thoroughly identify the degeneracies that result. We compare these signals to the predicted sensitivities of current and future instruments and determine that the James Webb Space Telescope should be able to constrain the obliquities of nearby warm Jupiters to be small (if ≤slant 10^\\circ ) or to directly measure them if significantly non-zero (≥slant 30^\\circ ) using the technique of eclipse mapping. For a bright target and assuming photon-limited precision, this could be done with a single secondary eclipse observation.

  7. Secondary tensor and supinator muscles of the human proximal radio-ulnar joint.

    Science.gov (United States)

    Hast, M H; Perkins, R E

    1986-01-01

    A gross anatomical study was made of the human elbow. Three very small muscles were found that are not described in contemporary anatomical publications. A lateral tensor muscle of the annular ligament was observed in seven of every ten cadavers; its action is to tense or pull the annular ligament laterally during supination. A medial tensor muscle of the annular ligament was found in two of every ten cadavers; its action is to tense the annular ligament, pulling it medially and distally, and to assist in supination. An accessory supinator muscle was found in four of ten cadavers; its action is to assist in supination. These muscles would be synergistic to the primary supinator muscles of the radio-ulnar joint. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:3693061

  8. Prevention of supine hypotensive syndrome in pregnant women undergoing computed tomography - A national survey of current practice

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, Michelle A.; Fenwick, Alison [Department of Diagnostic Imaging, Queen' s Medical Centre Campus, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham, NG7 2UH (United Kingdom); Banks, Amelia [Department of Anaesthesia, City Hospital Campus, Nottingham University Hospitals NHS Trust, Hucknall Road, Nottingham, NG5 1PB (United Kingdom); Dineen, Robert A. [Department of Diagnostic Imaging, Queen' s Medical Centre Campus, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham, NG7 2UH (United Kingdom)], E-mail: Robert.dineen@nhs.net

    2009-05-15

    Aim: Supine hypotensive syndrome (SHS) can occur in women in the second half of pregnancy due to compression of the aorta and inferior vena cava by the gravid uterus. This results in a decrease in cardiac output with effects ranging from transient asymptomatic hypotension to cardiovascular collapse. SHS can be easily avoided by left lateral tilt positioning. We undertook a nationwide survey to assess the awareness amongst senior computed tomography (CT) radiographers of the potential risk of SHS in women in this patient group, and to identify the extent to which preventative practices and protocols are in place. Methods and materials: A questionnaire was sent to superintendent CT radiographers at all acute NHS Trusts in England and Wales examining awareness of the risk of SHS and the preventative practices and protocols currently used. Results: Completed questionnaires were received from 64% institutions. Of respondents who scan women in this patient group, only 44% were aware of the risk of SHS. No institution had a written protocol specifying positioning of women in this patient group. Seventy-five percent of institutions never employed oblique positioning. Eighty-five percent felt that specific guidelines from the Society of Radiographers or Royal College of Radiologists would be helpful. Conclusion: Current awareness and practices for preventing this easily avoidable but potentially harmful condition are inadequate. Central guidance would be welcomed by a large majority of respondents.

  9. The Oblique Metaphyseal Shortening Osteotomy of the Distal Ulna: Surgical Technique and Results of Ten Patients.

    Science.gov (United States)

    Benis, Szabolcs; Goubau, Jean F; Mermuys, Koen; Van Hoonacker, Petrus; Berghs, Bart; Kerckhove, Diederick; Vanmierlo, Bert

    2017-02-01

    Background Ulnocarpal abutment is a common condition following distal radius fractures. There are different surgical methods of treatment for this pathology: open and arthroscopic wafer procedure or an ulnar shortening osteotomy. We describe an oblique metaphyseal shortening osteotomy of the distal ulna using two cannulated headless compression screws. We report the results of 10 patients treated with this method. Materials and Methods Out of 17 patients, 10 could be reviewed retrospectively for this study. Patient-rated outcomes were measured using the VAS (visual analogue scale) for pain, PRWHE (patient-rated wrist and hand evaluation) survey, and Quick-DASH (disability of arm, shoulder and hand) survey for functional outcomes. At the review we measured the range of motion (ROM) of the wrist (extension and flexion, ulnar and radial deviation, pronation and supination). Grip strength, pronation, and supination strength of the forearm was measured using a calibrated hydraulic dynamometer. ROM and strength of the affected wrist was compared with ROM and strength of the unaffected wrist. Surgical Procedure Oblique long metaphyseal osteotomy of the distal ulna (from proximal-ulnar to distal-radial), fixed with two cannulated headless compression screws. Results The average postoperative VAS score for pain was 23.71 (standard deviation [SD] of 30.41). The average postoperative PRWHE score was 32.55 (SD of 26.28). The average postoperative Quick-DASH score was 28.65 (SD of 27.21). The majority of patients had a comparable ROM and strength between the operated side and the non-operated side. Conclusion This surgical technique has the advantage of reducing the amount of hardware and to decrease the potential hinder caused by it on medium term. Moreover, the incision remains smaller, and the anatomic metaphyseal localization of the osteotomy potentially allows a better and rapid healing.

  10. Proton Acceleration at Oblique Shocks

    Science.gov (United States)

    Galinsky, V. L.; Shevchenko, V. I.

    2011-06-01

    Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

  11. Ionospheric Oblique Incidence Soundings by Satellites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The oblique incidence sweep-frequency ionospheric sounding technique uses the same principle of operation as the vertical incidence sounder. The primary difference...

  12. Oblique interactions of dust density waves

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhelchui [Los Alamos National Laboratory; Li, Yang - Fang [MAX-PLANCK INSTITUTE; Hou, Lujing [MAX-PLANCK INSTITUTE; Jiang, Ke [MAX-PLANCK INSTITUTE; Wu, De - Jin [CHINA; Thomas, Hubertus M [MAX-PLANCK INSTITUTE; Morfill, Gregor E [MAX-PLANCK INSTITUTE

    2010-01-01

    Self-excited dust density waves (DDWs) are studied in a striped electrode device. In addition to the usual perpendicularly (with respect to the electrode) propagating DDWs, which have been frequently observed in dusty plasma experiments on the ground, a low-frequency oblique mode is also observed. This low-frequency oblique DDW has a frequency much lower than the dust plasma frequency and its spontaneous excitation is observed even with a very low dust density. It is found that the low-frequency oblique mode can exist either separately or together with the usual perpendicular mode. In the latter case, a new mode arises as a result of the interactions between the perpendicular and the oblique modes. The experiments show that these three modes satisfy the wave coupling conditions in both the frequencies and the wave-vectors.

  13. ELECTROMYOGRAPHIC ACTIVITY OF THE VASTUS MEDIALIS OBLIQUE AND VASTUS LATERALIS DURING MAXIMUM VOLUNTARY ISOMETRICS IN DIFFERENT WEIGHT BEARING POSITIONS OF THE FOOT

    Directory of Open Access Journals (Sweden)

    Sreekar Kumar Reddy.R

    2014-09-01

    Full Text Available Background: Patellofemoral pain syndrome is a very common disorder. 90% of the general population has some degree of pathologic changes of the patellofemoral joint. Knowledge regarding the cause and prevention of patellofemoral pain syndrome is essential. Therefore the purpose of this study is intended to know whether different foot positions alter Vastus Medialis Oblique and Vastus Lateralis that leads to dysfunctions of knee joint. Method: 30 subjects are included in study and investigated foot in different foot positions are in neutral, pronated and supinated foot positions and performed maximum voluntary isometric contractions are recorded with electromyography. Results: EMG amplitudes (microvolts of VL and VMO at three different weight bearing positions of foot during maximum voluntary contraction analysis by using one-way Analysis of Variance. Mean amplitudes of foot positions in pronation shown significant difference while comparing with neutral and supination. Conclusion: The VMO and VL activity shows significant difference in the pronated foot weight bearing position compared to the neutral and supinated foot. Performing the maximum voluntary isometric contractions of VMO and VL with pronated foot elicited significantly higher EMG activity compared to Neutral or supinated weight bearing positions of foot. The results of this study also suggested that for patellofemoral pain which is caused by pronated foot can be treat with by using the soft foot orthoses

  14. Observations of Obliquely Propagating Electron Bernstein Waves

    DEFF Research Database (Denmark)

    Armstrong, R. J.; Juul Rasmussen, Jens; Stenzel, R. L.

    1981-01-01

    Plane electron Bernstein waves propagating obliquely to the magnetic field are investigated. The waves are excited by a plane grid antenna in a large volume magnetoplasma. The observations compare favorably with the predictions of the linear dispersion relation.......Plane electron Bernstein waves propagating obliquely to the magnetic field are investigated. The waves are excited by a plane grid antenna in a large volume magnetoplasma. The observations compare favorably with the predictions of the linear dispersion relation....

  15. Towards Efficiency of Oblique Images Orientation

    Science.gov (United States)

    Ostrowski, W.; Bakuła, K.

    2016-03-01

    Many papers on both theoretical aspects of bundle adjustment of oblique images and new operators for detecting tie points on oblique images have been written. However, only a few achievements presented in the literature were practically implemented in commercial software. In consequence often aerial triangulation is performed either for nadir images obtained simultaneously with oblique photos or bundle adjustment for separate images captured in different directions. The aim of this study was to investigate how the orientation of oblique images can be carried out effectively in commercial software based on the structure from motion technology. The main objective of the research was to evaluate the impact of the orientation strategy on both duration of the process and accuracy of photogrammetric 3D products. Two, very popular software: Pix4D and Agisoft Photoscan were tested and two approaches for image blocks were considered. The first approach based only on oblique images collected in four directions and the second approach included nadir images. In this study, blocks for three test areas were analysed. Oblique images were collected with medium-format cameras in maltan cross configuration with registration of GNSS and INS data. As a reference both check points and digital surface models from airborne laser scanning were used.

  16. TOWARDS EFFICIENCY OF OBLIQUE IMAGES ORIENTATION

    Directory of Open Access Journals (Sweden)

    W. Ostrowski

    2016-03-01

    Full Text Available Many papers on both theoretical aspects of bundle adjustment of oblique images and new operators for detecting tie points on oblique images have been written. However, only a few achievements presented in the literature were practically implemented in commercial software. In consequence often aerial triangulation is performed either for nadir images obtained simultaneously with oblique photos or bundle adjustment for separate images captured in different directions. The aim of this study was to investigate how the orientation of oblique images can be carried out effectively in commercial software based on the structure from motion technology. The main objective of the research was to evaluate the impact of the orientation strategy on both duration of the process and accuracy of photogrammetric 3D products. Two, very popular software: Pix4D and Agisoft Photoscan were tested and two approaches for image blocks were considered. The first approach based only on oblique images collected in four directions and the second approach included nadir images. In this study, blocks for three test areas were analysed. Oblique images were collected with medium-format cameras in maltan cross configuration with registration of GNSS and INS data. As a reference both check points and digital surface models from airborne laser scanning were used.

  17. Thermal transport in oblique finned microminichannels

    CERN Document Server

    Fan, Yan; Singh, Pawan Kumar; Lee, Yong Jiun

    2015-01-01

    The main aim of this book is to introduce and give an overview of a novel, easy, and highly effective heat transfer augmentation technique for single-phase micro/minichannel heat sink. The specific objectives of the volume are to: Introduce a novel planar oblique fin microchannel and cylindrical oblique fin minichannel heat sink design using passive heat transfer enhancement techniques  Investigate the thermal transport in both planar and cylindrical oblique fin structures through numerical simulation and systematic experimental studies. Evaluate the feasibility of employing the proposed solution in cooling non-uniform heat fluxes and hotspot suppression Conduct the similarity analysis and parametric study to obtain empirical correlations to evaluate the total heat transfer rate of the oblique fin heat sink Investigate the flow mechanism and optimize the dimensions of cylindrical oblique fin heat sink Investigate the influence of edge effect on flow and temperature uniformity in these oblique fin chan...

  18. Tidal obliquity evolution of potentially habitable planets

    CERN Document Server

    Heller, René; Barnes, Rory

    2011-01-01

    Stellar insolation has been used as the main constraint on a planet's habitability. However, as more Earth-like planets are discovered around low-mass stars (LMSs), a re-examination of the role of tides on the habitability of exoplanets has begun. Those studies have yet to consider the misalignment between a planet's rotational axis and the orbital plane normal, i.e. the planetary obliquity. We apply two equilibrium tide theories to compute the obliquity evolution of terrestrial planets orbiting in the habitable zones around LMSs. The time for the obliquity to decrease from an Earth-like obliquity of 23.5 deg to 5 deg, the 'tilt erosion time', is compared to the traditional insolation habitable zone (IHZ) as a function of semi-major axis, eccentricity, and stellar mass. We also compute tidal heating and equilibrium rotation caused by obliquity tides. The Super-Earth Gl581d and the planet candidate Gl581g are studied as examples for tidal processes. Earth-like obliquities of terrestrial planets in the IHZ arou...

  19. Radio-ulnar joint supinates around ball release during baseball fastball pitching.

    Science.gov (United States)

    Matsuo, Tomoyuki; Jinji, Tsutomu; Hirayama, Daisaku; Nasu, Daiki; Ozaki, Hiroki

    2016-06-01

    This study was conducted to determine whether a supination phase of the forearm exists around ball release (BRL), and, if present, to determine whether this supination is explained by a reaction force or by the body configuration required for this task. A 16-camera motion analysis system with a sampling frequency of 1,000 Hz recorded 20 healthy male semi-professional pitchers pitching from an indoor pitching mound. A short supination phase around BRL was confirmed for all participants in the current study. Correlation analyses revealed that the supination angle at BRL had significant relationships with several measurements of shoulder movement kinematics. Mechanical work analysis of the forearm's longitudinal axis revealed several variations in joint power curve and various patterns of mechanical work among the participants, suggesting that a reaction force originating from accelerating a ball might not be the main cause of supination. The raw data also were down-sampled to a sampling frequency of 250 Hz, to match previous studies and to investigate the discrepancy among previous studies concerning the existence of the supination phase. The experience of participants and methodological differences, such as the definition of BRL and the time-normalisation technique, influenced whether the supination phase was observed.

  20. Isometric elbow extensors strength in supine- and prone-lying positions.

    Science.gov (United States)

    Abdelzaher, Ibrahim E; Ababneh, Anas F; Alzyoud, Jehad M

    2013-01-01

    The purpose of this study was to compare isometric strength of elbow extensors measured in supine- and prone-lying positions at elbow flexion angles of 45 and 90 degrees. Twenty-two male subjects under single-blind procedures participated in the study. Each subject participated in both supine-lying and prone-lying measuring protocols. Calibrated cable tensiometer was used to measure isometric strength of the right elbow extensors and a biofeedback electromyography was used to assure no substitution movements from shoulder girdle muscles. The mean values of isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees were 11.1  ±  4.2 kg and 13.1  ±  4.6 kg, while those measured from prone-lying position were 9.9  ±  3.6 kg and 12  ±  4.2 kg, respectively. There is statistical significant difference between the isometric strength of elbow extensors measured from supine-lying position at elbow flexion angles of 45 and 90 degrees compared to that measured from prone-lying position (p  lying starting position is better than prone-lying starting position.

  1. Ultrasonography as a diagnostic tool in assessing deltoid ligament injury in supination external rotation fractures of the ankle.

    LENUS (Irish Health Repository)

    Henari, Shwan

    2011-10-01

    The medial deltoid ligament is the primary stabilizing structure in the ankle joint following lateral malleolar fracture. However, medial deltoid ligament ruptures are difficult to diagnose using current imaging modalities. We hypothesized that ultrasonography can be used to accurately allow early clinical assessment of ankle fracture stability, thereby negating the need to perform plain film stress views of the acutely injured ankle. This prospective study included 12 patients (age range, 18-72) with supination external rotation fractures requiring operative fixation. Following induction of anesthesia, ultrasonography examination was performed, followed by an arthrogram under fluoroscopic screening. Radiographs, ultrasonography, and arthrographic findings were compared. There was 100% correlation between ultrasonography and arthrogram findings. Ultrasonography accurately diagnosed medial deltoid rupture with a sensitivity of 100% and specificity of 100%. Plain film radiographs of the ankle had a sensitivity of 57.1% and a specificity of 60%. The difference between these was significant (χ(2)=.0091). This study demonstrates diagnostic ultrasonography to be an accurate diagnostic modality in assessing medial deltoid ligament integrity in patients with supination external rotation fractures. It offers the same sensitivity and specificity as arthrography without the need for additional invasive procedures. Its relative ease of use and lack of ionizing radiation make it a potentially useful tool, particularly in a busy trauma service.

  2. Alternative oblique head CT scanning technique reduces bone artifact and improves interpretability of brainstem anatomy

    Directory of Open Access Journals (Sweden)

    Sam Douglas Kampondeni

    2010-06-01

    Full Text Available Brainstem pathology due to infections, infarcts and tumors are common in developing countries, but neuroimaging technology in these resource-poor settings is often limited to single slice, and occasionally spiral, CT. Unlike multislice CT and MRI, single slice and spiral CT are compromised by bone artifacts in the posterior fossa due to the dense petrous bones, often making imaging of the brainstem non-diagnostic. With appropriate head positioning, the petrous ridges can be avoided with 40˚ sagittal oblique scans parallel to either petrous ridge. We describe an alternative sagittal oblique scanning technique that significantly reduces brainstem CT artifacts thereby improving clarity of anatomy. With Inst­itutional Ethical approval, 13 adult patients were enrolled (5 males; 39%. All patients had routine axial brain CT and sagittal oblique scans with no lesions found. Images were read by 2 readers who gave a score for amount of artefact and clarity of structures in the posterior fossa. The mean artifact score was higher for routine axial images compared to sagittal oblique (2.92 vs. 1.23; P<0.0001. The mean anatomical certainty scores for the brainstem were significantly better in the sagittal oblique views compared to routine axial (1.23 vs. 2.77; P<0.0001. No difference was found between the two techniques with respect to the fourth ventricle or the cerebellum (axial vs. sag oblique: 1.15 vs. 1.27; P=0.37. When using single slice CT, the sagittal oblique scanning technique is valuable in improving clarity of anatomy in the brainstem if axial images are non-diagnostic due to bone artifacts.

  3. A huge ovarian mucinous cystadenoma causing virilization, preterm labor, and persistent supine hypotensive syndrome during pregnancy.

    Science.gov (United States)

    Kucur, Suna Kabil; Acar, Canan; Temizkan, Osman; Ozagari, Aysim; Gozukara, Ilay; Akyol, Atif

    2016-01-01

    Mucinous cystadenoma (MC) of the ovary is an unilateral, multilocular cystic benign epithelial tumor. Supposed to be hormone responsive, MC reaches huge sizes during pregnancy. Aortocaval compression is common during pregnancy, especially when the pregnant woman is in the supine position. However, the compression recovers with a change in position. The authors report the first case of a huge mucinous cystadenoma of the ovary complicating pregnancy and causing virilization, premature labor, and persistent supine hypotensive syndrome.

  4. Colpocystoproctography in the upright and supine positions correlated with dynamic MRI of the pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert E-mail: hubert.gufler@radiol.med.uni-giessen.de; Ohde, Angelika; Grau, Gabriele; Grossmann, Anette

    2004-07-01

    Purpose: To test whether there are statistically significant differences between measurement results on colpocystoproctography in the upright and the supine positions, and to correlate these results with dynamic MRI. Patients and Methods: Seven patients with pelvic floor descent had received colpocystoproctography in the upright and supine positions and, additionally, dynamic MRI of the pelvic floor. Bladder neck position, angle of urethral inclination, posterior vesicourethral angle, and vaginal vault position were measured at relaxed pelvic floor and at pelvic strain. Differences between the measurement results of each parameter in the upright and supine position on colpocystoproctography were calculated and correlated with the measurement results from the dynamic MRI. Results: At pelvic strain, bladder neck position, angle of urethral inclination, posterior vesicourethral angle and vaginal vault position measurements showed no statistically significant differences between colpocystoproctography in the upright and supine positions or dynamic MRI. For the bladder neck height at pelvic floor relaxation, significant differences were found between colpocystoproctography in the upright and supine positions, and colpocystoproctography in the upright position versus dynamic MRI. Conclusion: At pelvic strain, measurement data from dynamic MRI are not statistically different from data from colpocystoproctography either in supine and upright positions.

  5. Comparison of cervical vertebral separation in the supine and seated positions using home traction units.

    Science.gov (United States)

    Fater, Dennis C W; Kernozek, Thomas W

    2008-01-01

    This study was performed for the purpose of comparing the magnitude of cervical vertebral separation during cervical traction in supine and seated positions using home traction units. A repeated measures design with two within-subject factors (type of traction and time) was used. Seventeen asymptomatic volunteers received cervical traction in seated and supine position. Subjects received 5 minutes of static traction in sitting or supine using a force of 13.6 kg while in 15 degrees of neck flexion. A lateral radiograph of the cervical spine was taken before traction force was applied and after five minutes of static traction. Anterior and posterior distances between the inferior border of C2 and the superior border of C7 were measured by a radiologist. After supine traction there were significant increases (p=0.001) in posterior cervical vertebral separation compared to any changes after seated traction. There were no significant changes in anterior vertebral separation during either supine or seated traction positions (p=0.769). Supine cervical traction may be more effective for increasing posterior vertebral separation than seated cervical traction.

  6. Solar Obliquity Induced by Planet Nine

    CERN Document Server

    Bailey, Elizabeth; Brown, Michael E

    2016-01-01

    The six-degree obliquity of the sun suggests that either an asymmetry was present in the solar system's formation environment, or an external torque has misaligned the angular momentum vectors of the sun and the planets. However, the exact origin of this obliquity remains an open question. Batygin & Brown (2016) have recently shown that the physical alignment of distant Kuiper Belt orbits can be explained by a 5-20 Earth-mass planet on a distant, eccentric, and inclined orbit, with an approximate perihelion distance of ~250 AU. Using an analytic model for secular interactions between Planet Nine and the remaining giant planets, here we show that a planet with similar parameters can naturally generate the observed obliquity as well as the specific pole position of the sun's spin axis, from a nearly aligned initial state. Thus, Planet Nine offers a testable explanation for the otherwise mysterious spin-orbit misalignment of the solar system.

  7. Dynamical Instabilities in High-Obliquity Systems

    CERN Document Server

    Tamayo, Daniel; Hamilton, Douglas P; Nicholson, Philip D

    2012-01-01

    High-inclination circumplanetary orbits that are gravitationally perturbed by the central star can undergo Kozai oscillations---large-amplitude, coupled variations in the orbital eccentricity and inclination. We first study how this effect is modified by incorporating perturbations from the planetary oblateness. Tremaine et al. (2009) found that, for planets with obliquities > 68.875 degrees, orbits in the equilibrium local Laplace plane are unstable to eccentricity perturbations over a finite radial range, and execute large-amplitude chaotic oscillations in eccentricity and inclination. In the hope of making that treatment more easily understandable, we analyze the problem using orbital elements, confirming this threshold obliquity. Furthermore, we find that orbits inclined to the Laplace plane will be unstable over a broader radial range, and that such orbits can go unstable for obliquities less than 68.875 degrees. Finally, we analyze the added effects of radiation pressure, which are important for dust gr...

  8. Oblique High Resolution Tomography: The Ideal Plane for Visualization of the Gonial Section of the Mandibular Canal and its Related Structures?

    Directory of Open Access Journals (Sweden)

    Heinz-Theo Lübbers

    2012-01-01

    Full Text Available A new radiologic technique is introduced in this paper for reducing the risk of nerve damage as a result of surgical removal of the mandibular third molar (wisdom tooth. The gonial part of the mandibular canal is obliquely scanned with tomograms on a plane parallel to this part of the mandibular canal. This procedure can be performed with the patient either prone or supine. The scans obtained cover a much longer section of the canal than the axial or coronal plane. Therefore, the scan provides more precise information on the spatial relationship between the mandibular canal and the surrounding structures with fewer images and, therefore, a lower radiation dose. Through such oblique plane scanning, metal artifacts from dental restorations do not impair visualization of the mandibular canal. Clinical cases demonstrating the advantages of this new technique are presented.

  9. Effective operator contributions to the oblique parameters

    CERN Document Server

    Sánchez-Colón, G

    1998-01-01

    We present a model and process independent study of the contributions from non-Standard Model physics to the oblique parameters S, T and U. We show that within an effective lagrangian parameterization the expressions for the oblique parameters in terms of observables are consistent, while those in terms of the vector-boson vacuum polarization tensors are ambiguous. We obtain the constraints on the scale of new physics derived from current data on S, T and U and note that deviations in U from its Standard Model value would favor a scenario where the underlying physics does not decouple.

  10. Oblique collision and deformation partitioning in the SW Iberian Variscides

    Science.gov (United States)

    Pérez-Cáceres, Irene; Simancas, José Fernando; Martínez Poyatos, David; Azor, Antonio; González Lodeiro, Francisco

    2016-05-01

    Different transpressional scenarios have been proposed to relate kinematics and complex deformation patterns. We apply the most suitable of them to the Variscan orogeny in SW Iberia, which is characterized by a number of successive left-lateral transpressional structures developed in the Devonian to Carboniferous period. These structures resulted from the oblique convergence between three continental terranes (Central Iberian Zone, Ossa-Morena Zone and South Portuguese Zone), whose amalgamation gave way to both intense shearing at the suture-like contacts and transpressional deformation of the continental pieces in-between, thus showing strain partitioning in space and time. We have quantified the kinematics of the collisional convergence by using the available data on folding, shearing and faulting patterns, as well as tectonic fabrics and finite strain measurements. Given the uncertainties regarding the data and the boundary conditions modeled, our results must be considered as a semi-quantitative approximation to the issue, though very significant from a regional point of view. The total collisional convergence surpasses 1000 km, most of them corresponding to left-lateral displacement parallel to terrane boundaries. The average vector of convergence is oriented E-W (present-day coordinates), thus reasserting the left-lateral oblique collision in SW Iberia, in contrast with the dextral component that prevailed elsewhere in the Variscan orogen. This particular kinematics of SW Iberia is understood in the context of an Avalonian plate salient currently represented by the South Portuguese Zone.

  11. Oblique Du-Fort Frankel Beam Propagation Method

    Directory of Open Access Journals (Sweden)

    Ken Chan

    2011-01-01

    Full Text Available The oblique BPM based on the Du-Fort Frankel method is presented. The paper demonstrates the accuracy and the computational improvements of the scheme compared to the oblique BPM based on Crank-Nicholson (CN scheme.

  12. Formation of transverse waves in oblique detonations

    NARCIS (Netherlands)

    Verreault, J.; Higgins, A.J.; Stowe, R.A.

    2013-01-01

    The structure of oblique detonation waves stabilized on a hypersonic wedge in mixtures characterized by a large activation energy is investigated via steady method of characteristics (MoC) calculations and unsteady computational flowfield simulations. The steady MoC solutions show that, after the tr

  13. Flow and sediment transport across oblique channels

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Madsen, Erik Østergaard; Fredsøe, Jørgen

    1998-01-01

    A 3D numerical investigation of flow across channels aligned obliquely to the main flow direction has been conducted. The applied numerical model solves the Reynolds-averaged Navier-Stokes equations using the k-ε model for turbulence closure on a curvilinear grid. Three momentum equations are sol...

  14. Oblique patterned etching of vertical silicon sidewalls

    Science.gov (United States)

    Bruce Burckel, D.; Finnegan, Patrick S.; David Henry, M.; Resnick, Paul J.; Jarecki, Robert L.

    2016-04-01

    A method for patterning on vertical silicon surfaces in high aspect ratio silicon topography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  15. Obliquity Modulation of the Incoming Solar Radiation

    Science.gov (United States)

    Liu, Han-Shou; Smith, David E. (Technical Monitor)

    2001-01-01

    Based on a basic principle of orbital resonance, we have identified a huge deficit of solar radiation induced by the combined amplitude and frequency modulation of the Earth's obliquity as possibly the causal mechanism for ice age glaciation. Including this modulation effect on solar radiation, we have performed model simulations of climate change for the past 2 million years. Simulation results show that: (1) For the past 1 million years, temperature fluctuation cycles were dominated by a 100-Kyr period due to amplitude-frequency resonance effect of the obliquity; (2) From 2 to 1 million years ago, the amplitude-frequency interactions. of the obliquity were so weak that they were not able to stimulate a resonance effect on solar radiation; (3) Amplitude and frequency modulation analysis on solar radiation provides a series of resonance in the incoming solar radiation which may shift the glaciation cycles from 41-Kyr to 100-Kyr about 0.9 million years ago. These results are in good agreement with the marine and continental paleoclimate records. Thus, the proposed climate response to the combined amplitude and frequency modulation of the Earth's obliquity may be the key to understanding the glaciation puzzles in paleoclimatology.

  16. Formation of transverse waves in oblique detonations

    NARCIS (Netherlands)

    Verreault, J.; Higgins, A.J.; Stowe, R.A.

    2013-01-01

    The structure of oblique detonation waves stabilized on a hypersonic wedge in mixtures characterized by a large activation energy is investigated via steady method of characteristics (MoC) calculations and unsteady computational flowfield simulations. The steady MoC solutions show that, after the tr

  17. Insolation patterns on synchronous exoplanets with obliquity

    Science.gov (United States)

    Dobrovolskis, Anthony R.

    2009-11-01

    A previous paper [Dobrovolskis, A.R., 2007. Icarus 192, 1-23] showed that eccentricity can have profound effects on the climate, habitability, and detectability of extrasolar planets. This complementary study shows that obliquity can have comparable effects. The known exoplanets exhibit a wide range of orbital eccentricities, but those within several million kilometers of their suns are generally in near-circular orbits. This fact is widely attributed to the dissipation of tides in the planets. Tides in a planet affect its spin even more than its orbit, and such tidally evolved planets often are assumed to be in synchronous rotation, so that their rotation periods are identical to their orbital periods. The canonical example of synchronous spin is the way that our Moon always keeps nearly the same hemisphere facing the Earth. Tides also tend to reduce the planet's obliquity (the angle between its spin and orbital angular velocities). However, orbit precession can cause the rotation to become locked in a "Cassini state", where it retains a nearly constant non-zero obliquity. For example, our Moon maintains an obliquity of about 6.7° with respect to its orbit about the Earth. In comparison, stable Cassini states can exist for practically any obliquity up to ˜90° or more for planets of binary stars, or in multi-planet systems with high mutual inclinations, such as are produced by scattering or by the Kozai mechanism. This work considers planets in synchronous rotation with circular orbits, but arbitrary obliquity β; this affects the distribution of insolation over the planet's surface, particularly near its poles. For β=0, one hemisphere bakes in perpetual sunshine, while the opposite hemisphere experiences eternal darkness. As β increases, the region of permanent daylight and the antipodal realm of endless night both shrink, while a more temperate area of alternating day and night spreads in longitude, and especially in latitude. The regions of permanent day or

  18. Oblique effect in visual mismatch negativity

    Directory of Open Access Journals (Sweden)

    Endre eTakács

    2013-09-01

    Full Text Available We investigated whether visual orientation anisotropies (known as oblique effect exist in non-attended visual changes using event-related potentials (ERP. We recorded visual mismatch negativity (vMMN which signals violation of sequential regularities. In the visual periphery unattended, task-irrelevant Gábor patches were displayed in an oddball sequence while subjects performed a tracking task in the central field. A moderate change (50° in the orientation of stimuli revealed no consistent change-related components. However we found orientation-related differences around 170 ms in occipito-temporal areas in the amplitude of the ERPs evoked by standard stimuli. In a supplementary experiment we determined the amount of orientation difference that is needed for change detection in an active, attended paradigm. Results exhibited the classical oblique effect; subjects detected 10° deviations from cardinal directions, while threshold from oblique directions was 17°. These results provide evidence that perception of change could be accomplished at significantly smaller thresholds, than what elicits vMMN. In Experiment2 we increased the orientation change to 90°. Deviant-minus-standard difference was negative in occipito-parietal areas, between 120-200 ms after stimulus onset. VMMNs to changes from cardinal angles were larger and more sustained than vMMNs evoked by changes from oblique angles. Changes from cardinal orientations represent a more detectable signal for the automatic change detection system than changes from oblique angles, thus increased vMMN to these larger deviances might be considered a variant of the magnitude of deviance effect rarely observed in vMMN studies.

  19. The Chicxulub Impact Crater and Oblique Impact

    Science.gov (United States)

    McDonald, M.; Gulick, S.; Melosh, H.; Christeson, G.

    2007-05-01

    Determining whether or not the Chicxulub impact was oblique (<45 degrees) will aid in our understanding of the environmental consequences 65 Ma. Planetary impact events, and impact simulations in the laboratory, show that oblique impacts have clear asymmetric ejecta distributions. However, the subsurface structures of the resultant craters are not well understood. In 2005, we acquired 1822 km of seismic reflection data onboard the R/V Maurice Ewing imaging the massive (200+ km) Chicxulub impact crater. The seismic profiles show that pre- crater stratigraphy outside the central basin of the Chicxulub impact crater is offset downward into the crater marking the post-impact slumping and formation of the terrace zone. The inward collapse of the Chicxulub terrace zone coincides with the outward collapse of the central uplift to form the peak ring. Chicxulub's peak ring is offset to the southeast, away from the deepest terrace zone mapped in the seismic data, suggesting that its peak ring was offset toward a more gradual wall of the transient cavity. Peak ring offsets, relative to crater center, of Venusian craters from radar images in the Magellan data set allow us to determine whether there are systematic variations in peak ring offset due to oblique impact. Ten pristine Venusian peak ring craters formed by oblique impact show that peak rings are offset both uprange and downrange, suggesting that peak ring position, and related subsurface asymmetries in the terrace zone, do not provide information about impact obliquity. This analysis supports the idea that Chicxulub's peak ring offset is a consequence of target properties and pre-impact structure and independent of impact trajectory.

  20. Semi-supine exercise stress echocardiography in children and adolescents: feasibility and safety.

    Science.gov (United States)

    Ciliberti, P; McLeod, I; Cairello, F; Kaski, J P; Fenton, M; Giardini, A; Marek, J

    2015-03-01

    Although exercise stress echocardiography (ESE) is a well-validated technique in adult population, its use in children is quite limited. We aimed to assess the feasibility, the safety and the reproducibility of ESE, using on-line scanning in semi-supine cyclo-ergometer protocol in a large pediatric population. Between July 2008 and January 2013, 42 patients (mean age 14 ± 3) were evaluated with a bicycle ESE performing 50 studies. ESE was successfully performed and well tolerated by all patients. None of the patients presented with adverse effects of stress-induced ischemia. HR was 82 ± 13 at rest, and 153 ± 19.1 during peak exercise. Among 544 views analyzed for grading of image quality, the visualization was optimal in 473 (87 %), suboptimal in 39, and inadequate in 32 (6 %). 37 tests were performed in patients with congenital or acquired coronary abnormality. Regional wall motion abnormalities (RWMA) were revealed in nine cases (24 %). The agreement between the two different observers showed a K index of 0.7276 (95 % CI 0.6497-0.8055) for the image quality and a K index of 0.5125 (95 % CI 0.4782-0.5468) for the RWMA analysis. Among ten patients with hypertrophic cardiomyopathy, we were able to demonstrate the new comparison of significant left ventricular outflow tract gradient (≥30 mmHg) during exercise in three patients (30 %). Bicycle stress echocardiography performed by on-line scanning during exercise is a feasible, safe, and reproducible modality in children. Further data to assess its diagnostic accuracy are, however, needed. Stress echocardiography provides a dynamic assessment of the myocardial structure and function under conditions of physiologic or pharmacologic stress.

  1. Three-dimensional modeling of supine human and transport system under whole-body vibration.

    Science.gov (United States)

    Wang, Yang; Rahmatalla, Salam

    2013-06-01

    The development of predictive computer human models in whole-body vibration has shown some success in predicting simple types of motion, mostly for seated positions and in the uniaxial vertical direction. The literature revealed only a handful of papers that tackled supine human modeling in response to vertical vibration. The objective of this work is to develop a predictive, multibody, three-dimensional human model to simulate the supine human and underlying transport system in response to multidirectional whole-body vibration. A three-dimensional dynamic model of a supine human and its underlying transport system is presented in this work to predict supine-human biodynamic response under three-dimensional input random whole-body vibration. The proposed supine-human model consists of three interconnected segments representing the head, torso-arms, and pelvis-legs. The segments are connected via rotational and translational joints that have spring-damper components simulating the three-dimensional muscles and tissuelike connecting elements in the three x, y, and z directions. Two types of transport systems are considered in this work, a rigid support and a long spinal board attached to a standard military litter. The contact surfaces between the supine human and the underlying transport system are modeled using spring-damper components. Eight healthy supine human subjects were tested under combined-axis vibration files with a magnitude of 0.5 m/s2 (rms) and a frequency content of 0.5-16 Hz. The data from seven subjects were used in parameter identification for the dynamic model using optimization schemes in the frequency domain that minimize the differences between the magnitude and phase of the predicted and experimental transmissibility. The predicted accelerations in the time and frequency domains were comparable to those gathered from experiments under different anthropometric, input vibration, and transport conditions under investigation. Based on the

  2. Prolapse assessment supine and standing: do we need different cutoffs for "significant prolapse"?

    Science.gov (United States)

    Rodríguez-Mias, Nuria-Laia; Subramaniam, Nishamini; Friedman, Talia; Shek, Ka Lai; Dietz, Hans Peter

    2017-04-25

    Translabial ultrasound (TLUS) has shown good correlations between clinical examination and imaging findings in the supine position, and limits of normality have been described. This is not the case for imaging in the standing position. This study was designed to test the hypothesis that different cutoff values are required for imaging in the standing position. This was a retrospective study carried out in a tertiary urogynecological unit in women presenting with symptoms of lower urinary tract and pelvic floor dysfunction between August 2013 and December 2015. All women underwent a standardized interview, 4D TLUS and a POP-Q assessment. Organ descent on ultrasound was measured relative to the postero-inferior margin of the symphysis pubis (SP) on maximal Valsalva in the supine and standing positions. Receiver operator characteristic (ROC) statistics were used to determine optimal cutoffs for "normal" pelvic organ support. We assessed 243 data sets. Mean patient age was 57 years. Prolapse symptoms were reported by 59.2%, and POP of stage ≥ 2 was found in 82.3%. On analysing imaging data sets obtained in the standing position, we obtained similar cutoff values to those established previously for supine imaging, using ROC statistics. The levator hiatus distended significantly more on Valsalva in the standing position compared with supine, and on ROC analysis we identified a new optimal cutoff of 29 cm(2). Established cutoffs for supine imaging of organ descent are suitable for imaging in the standing position. Hiatal distensibility may require a higher cutoff of 29 cm(2).

  3. Physiological Response to Static Muscle Contractions in Standing and Supine Positions

    DEFF Research Database (Denmark)

    Pedersen, Jens Meldgaard; Andersen, T. Bull

    2013-01-01

    The purpose of this study was to investigate the physiological responses to static muscle contractions in the standing position and the supine position. Eight subjects performed static contractions of the ankle extensors in both positions. Blood pressure (SBP and DBP), heart rate (HR......), electromyography (EMG), and near-infrared spectroscopy (NIRS) were determined during the static contractions. The results of main interest were a significantly larger initial decline of muscle oxygen concentration and a steeper negative slope of the frequency content in the EMG signals in the supine position....... These results indicate that the fatigue development is more pronounced in a supine position, which is most likely due to changes in muscle blood flow....

  4. Oblique Aerial Photography Tool for Building Inspection and Damage Assessment

    Science.gov (United States)

    Murtiyoso, A.; Remondino, F.; Rupnik, E.; Nex, F.; Grussenmeyer, P.

    2014-11-01

    Aerial photography has a long history of being employed for mapping purposes due to some of its main advantages, including large area imaging from above and minimization of field work. Since few years multi-camera aerial systems are becoming a practical sensor technology across a growing geospatial market, as complementary to the traditional vertical views. Multi-camera aerial systems capture not only the conventional nadir views, but also tilted images at the same time. In this paper, a particular use of such imagery in the field of building inspection as well as disaster assessment is addressed. The main idea is to inspect a building from four cardinal directions by using monoplotting functionalities. The developed application allows to measure building height and distances and to digitize man-made structures, creating 3D surfaces and building models. The realized GUI is capable of identifying a building from several oblique points of views, as well as calculates the approximate height of buildings, ground distances and basic vectorization. The geometric accuracy of the results remains a function of several parameters, namely image resolution, quality of available parameters (DEM, calibration and orientation values), user expertise and measuring capability.

  5. Inferior oblique weakening surgery on ocular torsion in congenital superior oblique palsy

    Directory of Open Access Journals (Sweden)

    Jinho Lee

    2015-06-01

    Full Text Available AIM:To investigate changes in fundus excyclotorsion after inferior oblique myectomy or myotomy.METHODS:The records of 21 patients undergoing strabismus surgery by a single surgeon between 2009 and 2012 were examined. Only patients who had undergone an inferior oblique myectomy or myotomy, with or without horizontal rectus muscle surgery, were evaluated. Digital fundus photographs were obtained, and the angle formed by a horizontal line passing through the optic disc center and a reference line connecting the foveola and optic disc center was measured. Associated clinical factors examined include age at the time of surgery, presence or absence of a head tilt, degree of preoperative vertical deviation, torsional angle, inferior oblique muscle overaction/superior oblique muscle underaction, and surgery laterality. Whether the procedure was performed alone or in combination with a horizontal rectus muscle surgery was also examined.RESULTS:Mean preoperative torsional angle was 12.0±6.4°, which decreased to 6.9±5.7° after surgery (P<0.001, paired t-test. Torsional angle also decreased from 15.1±7.0° to 6.2±4.3° in the myectomy group (P<0.001, paired t-test but there were no significant changes in the myotomy group (P=0.093, Wilcoxon signed rank test. Multivariable linear regression analysis showed that preoperative torsional angle, degree of inferior oblique overaction, and age at surgery independently and significantly affected postoperative torsional angle.CONCLUSION:Mean torsional angle decreased after inferior oblique myectomy. Degree of preoperative torsional angle, inferior oblique overaction, and age at surgery influence postoperative torsional angle.

  6. Proton beam generation of oblique whistler waves

    Science.gov (United States)

    Wong, H. K.; Goldstein, M. L.

    1988-01-01

    It is known that ion beams are capable of generating whistler waves that propagate parallel to the mean magnetic field. Such waves may have been observed both upstream of the earth's bow shock and in the vicinity of comets. Previous analyses are extended to include propagation oblique to the mean magnetic field. The instability is generated by the perpendicular component of free energy in the ions, which can arise either via a temperature anisotropy or via a gyrating distribution. In the former case, the generation of whistler waves is confined to a fairly narrow cone of propagation directions centered about parallel propagation; in the latter case, the maximum growth of the instability can occur at fairly large obliquities (theta equal to about 50 deg).

  7. Obliquely propagating dust-density waves

    Science.gov (United States)

    Piel, A.; Arp, O.; Klindworth, M.; Melzer, A.

    2008-02-01

    Self-excited dust-density waves are experimentally studied in a dusty plasma under microgravity. Two types of waves are observed: a mode inside the dust volume propagating in the direction of the ion flow and another mode propagating obliquely at the boundary between the dusty plasma and the space charge sheath. The dominance of oblique modes can be described in the frame of a fluid model. It is shown that the results fom the fluid model agree remarkably well with a kinetic electrostatic model of Rosenberg [J. Vac. Sci. Technol. A 14, 631 (1996)]. In the experiment, the instability is quenched by increasing the gas pressure or decreasing the dust density. The critical pressure and dust density are well described by the models.

  8. Resolution of superior oblique myokymia with memantine.

    Science.gov (United States)

    Jain, Saurabh; Farooq, Shegufta J; Gottlob, Irene

    2008-02-01

    We describe a novel treatment of superior oblique myokymia. A 40-year-old woman was treated with gabapentin for this disorder with partial success and reported significant side effects including loss of libido and weight gain. After a drug holiday, memantine therapy was initiated resulting in a substantial improvement in her symptoms with far fewer side effects and stability on long-term maintenance therapy.

  9. Low stellar obliquities in compact multiplanet systems

    CERN Document Server

    Albrecht, Simon; Marcy, Geoffrey W; Howard, Andrew W; Isaacson, Howard; Johnson, John A

    2013-01-01

    We measure the sky-projected stellar obliquities (\\lambda) in the multiple-transiting planetary systems KOI-94 and Kepler-25, using the Rossiter-McLaughlin effect. In both cases the host stars are well-aligned with the orbital planes of the planets. For KOI-94 we find \\lambda=-11+-11 deg, confirming a recent result by Hirano and coworkers. Kepler-25 was a more challenging case because the transit depth is unusually small (0.13 %). To obtain the obliquity it was necessary to use prior knowledge of the star's projected rotation rate, and apply two different analysis methods to independent wavelength regions of the spectra. The two methods gave consistent results, \\lambda=7+-8 deg and -0.5+-5.7 deg. There are now a total of five obliquity measurements for host stars of systems of multiple transiting planets, all of which are consistent with spin-orbit alignment. This alignment is unlikely to be the result of tidal interactions, because of the relatively large orbital distances and low planetary masses in the sys...

  10. On the oscillations in Mercury's obliquity

    CERN Document Server

    Bois, E

    2007-01-01

    One major objective of MESSENGER and BepiColombo spatial missions is to accurately measure Mercury's rotation and its obliquity in order to obtain constraints on internal structure of the planet. Which is the obliquity's dynamical behavior deriving from a complete spin-orbit motion of Mercury simultaneously integrated with planetary interactions? We have used our SONYR model integrating the spin-orbit N-body problem applied to the solar System (Sun and planets). For lack of current accurate observations or ephemerides of Mercury's rotation, and therefore for lack of valid initial conditions for a numerical integration, we have built an original method for finding the libration center of the spin-orbit system and, as a consequence, for avoiding arbitrary amplitudes in librations of the spin-orbit motion as well as in Mercury's obliquity. The method has been carried out in two cases: (1) the spin-orbit motion of Mercury in the 2-body problem case (Sun-Mercury) where an uniform precession of the Keplerian orbita...

  11. The effect of a Galeazzi fracture on the strength of pronation and supination two years after surgical treatment

    NARCIS (Netherlands)

    Ploegmakers, J. J. W.; The, B.; Brutty, M.; Ackland, T. R.; Wang, A. W.

    2013-01-01

    The aim of this study was to determine the effect of a Galeazzi fracture on the strength of pronation and supination at a mean of two years after surgical treatment. The strength of pronation and supination was measured in varying rotational positions of the forearm of ten male patients (mean age

  12. The effect of a Galeazzi fracture on the strength of pronation and supination two years after surgical treatment

    NARCIS (Netherlands)

    Ploegmakers, J. J. W.; The, B.; Brutty, M.; Ackland, T. R.; Wang, A. W.

    2013-01-01

    The aim of this study was to determine the effect of a Galeazzi fracture on the strength of pronation and supination at a mean of two years after surgical treatment. The strength of pronation and supination was measured in varying rotational positions of the forearm of ten male patients (mean age 38

  13. On the three-quarter view advantage of familiar object recognition.

    Science.gov (United States)

    Nonose, Kohei; Niimi, Ryosuke; Yokosawa, Kazuhiko

    2016-11-01

    A three-quarter view, i.e., an oblique view, of familiar objects often leads to a higher subjective goodness rating when compared with other orientations. What is the source of the high goodness for oblique views? First, we confirmed that object recognition performance was also best for oblique views around 30° view, even when the foreshortening disadvantage of front- and side-views was minimized (Experiments 1 and 2). In Experiment 3, we measured subjective ratings of view goodness and two possible determinants of view goodness: familiarity of view, and subjective impression of three-dimensionality. Three-dimensionality was measured as the subjective saliency of visual depth information. The oblique views were rated best, most familiar, and as approximating greatest three-dimensionality on average; however, the cluster analyses showed that the "best" orientation systematically varied among objects. We found three clusters of objects: front-preferred objects, oblique-preferred objects, and side-preferred objects. Interestingly, recognition performance and the three-dimensionality rating were higher for oblique views irrespective of the clusters. It appears that recognition efficiency is not the major source of the three-quarter view advantage. There are multiple determinants and variability among objects. This study suggests that the classical idea that a canonical view has a unique advantage in object perception requires further discussion.

  14. Posture and movement in healthy preterm infants in supine position in and outside the nest

    NARCIS (Netherlands)

    Ferrari, F.; Bertoncelli, N.; Gallo, C.; Roversi, M. F.; Guerra, M. P.; Ranzi, A.; Madders-Algra, M.

    2007-01-01

    Objective: To evaluate whether lying in a nest affects the posture and spontaneous movements of healthy preterm infants. Method: 10 healthy preterm infants underwent serial video recording in the supine position, when lying in a nest and outside it, at three ages: 30-33 weeks postmenstrual age (PMA)

  15. Supine or prone position for mini-PNL procedure: does it matter.

    Science.gov (United States)

    Tokatlı, Zafer; Gokce, Mehmet Ilker; Süer, Evren; Sağlam, Remzi

    2015-06-01

    In this study it is aimed to compare the success and complication rates of mini-PNL procedure in supine and prone positions. In this retrospective study data of 180 patients treated with MPNL either in supine (n = 54) or prone (n = 126) positions between May 2009 and August 2014 was investigated. Success was defined as no visible stones >2 mm. Perioperative complications were classified using the modified Clavien system. Groups were compared with Chi square test or Student t test and for statistical significance p value of 0.05 was accepted. Mean age of the population was 42.5 ± 8.2 years and mean stone size was 23.9 ± 4.1 mm. The two groups were similar with regard to demographic characteristics and stone related characteristics except the ASA status. Success rates of the supine and prone groups were 85.1 and 87.3%, respectively (p = 0.701). No statistically significant differences in terms of complications were observed. Mean operative time was the only parameter different between the two groups (55 vs 82 min, p = 0.001). Supine position for PNL seems to be promising and the complication and success rates are shown to be similar to the prone position with MPNL technique. The only significant benefit of this technique is shorter operative time.

  16. Video-assisted thoracic surgery for superior posterior mediastinal neurogenic tumour in the supine position

    Directory of Open Access Journals (Sweden)

    Darlong Laleng

    2009-01-01

    Full Text Available Video-assisted thoracic surgery (VATS for a superior posterior mediastinal lesion is routinely done in the lateral decubitus position similar to a standard thoracotomy using a double-lumen endotracheal tube for one-lung ventilation. This is an area above the level of the pericardium, with the superior thoracic opening as its superior limit and its inferior limit at the plane from the sternal angle to the level of intervertebral disc of thoracic 4 to 5 vertebra lying behind the great vessels. The lateral decubitus position has disadvantages of the double-lumen endotracheal tube getting malpositioned during repositioning from supine position to the lateral decubitus position, shoulder injuries due to the prolonged abnormal fixed posture and rarer injuries of the lower limb. There is no literature related to VATS in the supine position for treating lesions in the posterior mediastinum because the lung tissue falls in the dependent posterior mediastinum and obscures the field of surgery; however, VATS in the supine position is routinely done for lesions in the anterior mediastinum and single-stage bilateral spontaneous pneumothorax. Thus, in the selected cases, ′VATS in supine position′ allows an invasive procedure to be completed in the most stable anatomical posture.

  17. Dorian Supin käis Pärdi asjus Argentinas / T.T.

    Index Scriptorium Estoniae

    T.T.

    2003-01-01

    Dokumentaalfilm helilooja Arvo Pärdist "24 prelüüdi ühele fuugale". Filmi stsenarist, režissöör ja operaator Dorian Supin näitas seda suure menuga Buenos Airese San Martini ülikoolis spetsiaalse seminari osavõtjatele

  18. MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

    Science.gov (United States)

    Renzi, Adolfo; Monaco, Luigi; Serra, Nicola; Feragalli, Beatrice; Iacomino, Aniello; Brunese, Luca; Cappabianca, Salvatore

    2016-01-01

    Introduction. Functional disorders of the pelvic floor represent have a significant impact on the quality of life. The advent of open-configuration systems allowed for the evaluation of defecation with MR imaging in sitting position. The purpose of the present study is to compare the results of static and dynamic pelvic MR performed in supine position versus sitting position, using a new MR prototype machine, in the diagnosis of pelvic floor descent. Materials and Methods. Thirty-one patients with pelvic floor disorders were enrolled, and underwent MR Defecography in supine position with 1.5 T closed magnet (MAGNETOM Symphony, Siemens, Germany) and in sitting position with a 0.25-Tesla open magnet system (G-Scan ESAOTE, Italy). Results. In rest and squeezing phases, positions of bladder, vagina, and ARJ were significantly different when the patient was imaged in supine versus sitting position. In the defecation phase, a significant difference for the bladder and vagina position was detected between the two exams whereas a significant difference for the ARJ was not found. A statistically significant difference exists when the pelvic floor descent is evaluated in sitting versus supine position. Conclusion. Our results show that MR Defecography in sitting position may represent a useful tool to correctly diagnose and grade the pelvic organ descent. PMID:26880893

  19. MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

    Directory of Open Access Journals (Sweden)

    Francesca Iacobellis

    2016-01-01

    Full Text Available Introduction. Functional disorders of the pelvic floor represent have a significant impact on the quality of life. The advent of open-configuration systems allowed for the evaluation of defecation with MR imaging in sitting position. The purpose of the present study is to compare the results of static and dynamic pelvic MR performed in supine position versus sitting position, using a new MR prototype machine, in the diagnosis of pelvic floor descent. Materials and Methods. Thirty-one patients with pelvic floor disorders were enrolled, and underwent MR Defecography in supine position with 1.5 T closed magnet (MAGNETOM Symphony, Siemens, Germany and in sitting position with a 0.25-Tesla open magnet system (G-Scan ESAOTE, Italy. Results. In rest and squeezing phases, positions of bladder, vagina, and ARJ were significantly different when the patient was imaged in supine versus sitting position. In the defecation phase, a significant difference for the bladder and vagina position was detected between the two exams whereas a significant difference for the ARJ was not found. A statistically significant difference exists when the pelvic floor descent is evaluated in sitting versus supine position. Conclusion. Our results show that MR Defecography in sitting position may represent a useful tool to correctly diagnose and grade the pelvic organ descent.

  20. Dorian Supin käis Pärdi asjus Argentinas / T.T.

    Index Scriptorium Estoniae

    T.T.

    2003-01-01

    Dokumentaalfilm helilooja Arvo Pärdist "24 prelüüdi ühele fuugale". Filmi stsenarist, režissöör ja operaator Dorian Supin näitas seda suure menuga Buenos Airese San Martini ülikoolis spetsiaalse seminari osavõtjatele

  1. Goal directed reaching and postural control in supine position in healthy infants

    NARCIS (Netherlands)

    Fallang, B; Saugstad, OD; Hadders-Algra, M

    2000-01-01

    The present study focussed on the development and interaction of reaching and posture in supine position in young infants. The kinematics of goal directed reaches and the concurrent ground reaction forces of the total body centre of pressure (COP) in cranial-caudal and medial-lateral direction were

  2. Effects of supine, prone, and lateral positions on cardiovascular and renal variables in humans

    DEFF Research Database (Denmark)

    Pump, Bettina; Talleruphuus, Ulrik; Christensen, Niels Juel

    2002-01-01

    The hypothesis was tested that changing the direction of the transverse gravitational stress in horizontal humans modulates cardiovascular and renal variables. On different study days, 14 healthy males were placed for 6 h in either the horizontal supine or prone position following 3 h of being...... ml, P variables, whereas left atrial diameter increased (32 +/- 1 to 35 +/- 1 mm, P

  3. Comparison of the dose to lung volume between supine and prone position during treatment planning

    Institute of Scientific and Technical Information of China (English)

    Yu Li; Huijun Xu ; Sujing Zhang; Xiaoliang Liu

    2015-01-01

    Objective The aim of the study was to compare the dose to lung volume in the supine and prone posi-tion while designing CyberKnife treatment plans to treat metastatic tumors in the spinous processes of the thoracic vertebrae, and of er a reference for reducing damage to normal tissues. Methods Nine cases of metastatic tumors in the spinous processes of the thoracic vertebrae were se-lected, and then we designed treatment plans based on the supine and prone positions and compared the results. Results In contrast with the treatment plan based on the prone position, the one for the supine position required 14862–36337 MU more; the lung D5% was 5.20–7.90 Gy higher; and the lung D20% was 2.61–5.73 Gy higher. The dif erence of dose to spine volume between the two plans was –2.21–2.67 Gy; to the skin volume was –3.93–7.85 Gy; and to the esophagus was 0.28–6.39 Gy. Conclusion The treatment plan based on the prone position of patients can better protect lung tissues than the one based on the supine position, and can also improve the availability of beams.

  4. Face-down positioning versus non-supine positioning in macular hole surgery

    DEFF Research Database (Denmark)

    Alberti, Mark; Dornonville de la Cour, Morten

    2015-01-01

    AIM: To evaluate the full thickness macular hole (FTMH) closure rate in patients positioning non-supine (NSP) compared with patients positioning face-down (FDP). METHODS: We retrospectively reviewed two FTMH case series-postoperative positioning was FDP and NSP, respectively. All eyes were pseudo...

  5. Measures of the Earth Obliquity during the 1701 Winter Solstice at the Clementine Meridian Line in Rome

    CERN Document Server

    Andrei, Alexandre Humberto; Regoli, Veronica

    2014-01-01

    The great meridian line in the Basilica of Santa Maria degli Angeli in Rome was built in 1701/1702 with the scope of measuring the obliquity of the Earth's orbit in the following eight centuries, upon the will of Pope Clement XI. During the winter solstice of 1701 the first measurements of the obliquity were taken by Francesco Bianchini. He was the astronomer who designed the meridian line, upgrading the similar instrument realized by Giandomenico Cassini in San Petronio, Bononia. The accuracy of the data is discussed from the point of view of the use of the pinhole.

  6. CHARACTERISTICS OF MAXIMUM PERFORMANCE OF PEDALING EXERCISE IN RECUMBENT AND SUPINE POSITIONS

    Directory of Open Access Journals (Sweden)

    Morimasa Kato

    2011-09-01

    Full Text Available To determine the characteristics of maximum pedaling performance in the recumbent and supine positions, maximum isokinetic leg muscle strength was measured in eight healthy male subjects during pedaling at three velocities (300°/s, 480°/s, and 660°/s, and maximum incremental tests were performed for each position. The maximum isokinetic muscle strength in the recumbent position was 210.0 ± 29.2 Nm at 300°/s, 158.4 ± 19.8 Nm at 480°/s, and 110.6 ± 13.2 at 660°/s. In contrast, the muscle strength in the supine position was 229.3 ± 36.7 Nm at 300°/s, 180. 7 ± 20.3 Nm at 480°/s, and 129.6 ± 14.0 Nm at 660°/s. Thus, the maximum isokinetic muscle strength showed significantly higher values in the supine position than in the recumbent position at all angular velocities. The knee and hip joint angles were measured at peak torque using a goniometer; the knee joint angle was not significantly different between both positions, whereas the hip joint angle was greater in the supine position than in the recumbent position (Supine position: 137.3 ± 9. 33 degree at 300°/s, 140.0 ± 11.13 degrees at 480°/s, and 141.0 ± 9.61 degrees at 660°/s. Recumbent position: 99.5 ± 12.21 degrees at 300°/s, 101.6 ± 12.29 degrees at 480°/s, and 105.8 ± 14.28 degrees at 660°/s. Peak oxygen uptake was higher in the recumbent position (50.3 ± 4.43 ml·kg-1·min-1 than in the supine position (48.7 ± 5.10 ml·kg-1·min-1. At maximum exertion, the heart rate and whole-body rate of perceived exertion (RPE were unaffected by position, but leg muscle RPE was higher in the supine position (19.5 ± 0.53 than in the recumbent position (18.8 ± 0.71. These results suggest that the supine position is more suitable for muscle strength exertion than the recumbent position, and this may be due to different hip joint angles between the positions. On the contrary, the endurance capacity was higher in the recumbent position than in the supine position. Since leg muscle

  7. Reliability of shoulder internal rotation passive range of motion measurements in the supine versus sidelying position.

    Science.gov (United States)

    Lunden, Jason B; Muffenbier, Mike; Giveans, M Russell; Cieminski, Cort J

    2010-09-01

    Clinical measurement, reliability. To compare intrarater and interrater reliability of shoulder internal rotation (IR) passive range of motion measurements utilizing a standard supine position and a sidelying position. Glenohumeral IR range of motion deficits are often noted in patients with shoulder pathology. Excellent intrarater reliability has been found when measuring this motion. However, interrater reliability has been reported as poor to fair. Some clinicians currently use a sidelying position for IR stretching with patients who have shoulder pathology. However, no objective data exist for IR passive range of motion measured in this sidelying position, either in terms of reliability or normative values. Seventy subjects (mean age, 36.8 years), with (n = 19) and without (n = 51) shoulder pathology, were included in this study. Shoulder IR passive range of motion of the dominant shoulder or involved shoulder was measured by 2 investigators in 2 positions: (1) a standard supine position, with the shoulder at 90 degrees of abduction, and (2) in sidelying on the tested side, with the shoulder flexed to 90 degrees . Intrarater reliability for supine measurements was good to excellent (ICC3,1 = 0.70-0.93) and for sidelying measurements was excellent (ICC3,1 = 0.94-0.98). Interrater reliability was fair to good for the supine measurement (ICC2,2 = 0.74-0.81) and good to excellent for the sidelying measurement (ICC2,2 = 0.88-0.96). The mean (range) value of the dominant shoulder sidelying IR passive range of motion was 40 degrees (11 degrees to 69 degrees ) for healthy subjects and 25 degrees (-16 degrees to 49 degrees) for subjects with shoulder pathology. For subjects with shoulder pathology, measurements of shoulder IR made in the sidelying position had superior intrarater and interrater reliability compared to those in the standard supine position.

  8. A Novel Oblique Detonation Structure and Its Stability

    Institute of Scientific and Technical Information of China (English)

    TENG Hong-Hui; ZHAO Wei; JIANG Zong-Lin

    2007-01-01

    Oblique detonation structures induced by the wedge in the supersonic combustible gas mixtures are simulated numerically. The results show that the stationary oblique detonation structures are influenced by the gas flow Mach number, and a novel critical oblique detonation structure, which is characterized by a more complicated wave system, appears in the low Mach number cases. By introducing the inflow disturbance, its nonstationary evolution process is illustrated and its stability is verified.

  9. Stability analysis of the Martian obliquity during the Noachian era

    OpenAIRE

    2011-01-01

    Abstract We performed numerical simulations of the obliquity evolution of Mars during the Noachian era, at which time the giant planets were on drastically different orbits than today. For the preferred primordial configuration of the planets we find that there are two large zones where the Martian obliquity is stable and oscillates with an amplitude lower than 20?. These zones occur at obliquities below 30?and above 60?; intermediate values show either resonant or chaotic behaviou...

  10. Oblique Water Wave Diffraction by a Step

    Directory of Open Access Journals (Sweden)

    Dolai P.

    2017-02-01

    Full Text Available This paper is concerned with the problem of diffraction of an obliquely incident surface water wave train on an obstacle in the form of a finite step. Havelock expansions of water wave potentials are used in the mathematical analysis to obtain the physical parameters reflection and transmission coefficients in terms of integrals. Appropriate multi-term Galerkin approximations involving ultraspherical Gegenbauer polynomials are utilized to obtain a very accurate numerical estimate for reflection and transmission coefficients which are depicted graphically. From these figures various interesting results are discussed.

  11. Oblique Water Wave Diffraction by a Step

    Science.gov (United States)

    Dolai, P.

    2017-02-01

    This paper is concerned with the problem of diffraction of an obliquely incident surface water wave train on an obstacle in the form of a finite step. Havelock expansions of water wave potentials are used in the mathematical analysis to obtain the physical parameters reflection and transmission coefficients in terms of integrals. Appropriate multi-term Galerkin approximations involving ultraspherical Gegenbauer polynomials are utilized to obtain a very accurate numerical estimate for reflection and transmission coefficients which are depicted graphically. From these figures various interesting results are discussed.

  12. A note on oblique water entry

    KAUST Repository

    Moore, M. R.

    2012-10-02

    A minor error in Howison et al. (J. Eng. Math. 48:321-337, 2004) obscured the fact that the points at which the free surface turns over in the solution of the Wagner model for the oblique impact of a two-dimensional body are directly related to the turnover points in the equivalent normal impact problem. This note corrects some of the earlier results given in Howison et al. (J. Eng. Math. 48:321-337, 2004) and discusses the implications for the applicability of the Wagner model. © 2012 Springer Science+Business Media B.V.

  13. Non-oblique Correction in Extenden Technicolor Theory

    CERN Document Server

    Kitazawa, N

    1993-01-01

    We study radiative corrections on $Zb{\\bar b}$ vertex generated by the ETC gauge bosons, ``diagonal'' as well as sideways. Although the oblique corrections due to the ETC bosons are small in comparison with the oblique correction due to the technicolor dynamics, the non-oblique corrections result in substantial shift of contour plot in the $S$-$T$ plane. We show that such a shift due to the non-oblique corrections is actually important for discussing $S$ and $T$ values in the technicolor models.

  14. Graph Matching for the Registration of Persistent Scatterers to Optical Oblique Imagery

    Science.gov (United States)

    Schack, L.; Soergel, U.; Heipke, C.

    2016-06-01

    Matching Persistent Scatterers (PS) to airborne optical imagery is one possibility to augment applications and deepen the understanding of SAR processing and products. While recently this data registration task was done with PS and optical nadir images the alternatively available optical oblique imagery is mostly neglected. Yet, the sensing geometry of oblique images is very similar in terms of viewing direction with respect to SAR.We exploit the additional information coming with these optical sensors to assign individual PS to single parts of buildings. The key idea is to incorporate topology information which is derived by grouping regularly aligned PS at facades and use it together with a geometry based measure in order to establish a consistent and meaningful matching result. We formulate this task as an optimization problem and derive a graph matching based algorithm with guaranteed convergence in order to solve it. Two exemplary case studies show the plausibility of the presented approach.

  15. The value of oblique pinhole images in pre-operative localisation with {sup 99m}Tc-MIBI for primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Ho Shon, I.A. [Dept. of Nuclear Medicine, Royal North Shore Hospital, Sydney (Australia); Bernard, E.J.; Roach, P.J. [Dept. of Nuclear Medicine, Royal North Shore Hospital, Sydney (Australia); North Shore Radiology and Nuclear Medicine, North Shore Private Hospital, Sydney (Australia); Delbridge, L.W. [Dept. of Surgery, Royal North Shore Hospital, Sydney (Australia)

    2001-06-01

    Technetium-99m labelled 2-methoxyisobutylisonitrile (MIBI) has been extensively utilised for pre-operative localisation of parathyroid adenomas. Imaging techniques have varied widely, with many centres not performing routine oblique images; thus this study aimed to examine the value of routine oblique pinhole imaging. Ninety-two patients underwent pre-operative {sup 99m}Tc-MIBI imaging including early and delayed anterior oblique pinhole images in addition to standard anterior pinhole images and a thyroid study prior to surgery for primary hyperparathyroidism. These studies were reviewed blindly comparing anterior and oblique images and anterior images only in relation to surgical findings. Of the 92 patients, 83 were found to have 86 parathyroid adenomas or parathyroid adenoma/hyperplasia at surgery. When compared to anterior images only, oblique views improved overall sensitivity from 76% to 88% (P<0.05), correctly localised 11 more adenomas than anterior images alone (13%) and improved the confidence of interpretation in 17 patients (20%). In conclusion, routine oblique pinhole views result in greater sensitivity and reporter confidence in pre-operative parathyroid localisation with {sup 99m}Tc-MIBI. (orig.)

  16. Ionospheric heating with oblique HF waves

    Science.gov (United States)

    Field, Edward C., Jr.; Bloom, Ron M.

    1990-10-01

    Calculations of ionospheric electron density perturbations and ground-level signal changes produce by intense oblique high frequency (HF) transmitters are presented. This analysis considers radio field focusing at caustics, the consequent joule-heating of the surrounding plasma, heat conduction, diffusion, and recombination processes: these being the effects of a powerful oblique 'modifying' wave. It neglects whatever plasma instabilities might occur. Then effects on a secondary 'test' wave that is propagated along the same path as the first are investigated. Calculations predict ground-level field-strength reductions of several dB in the test wave for modifying waves having ERP in the 85 to 90 dBW range. These field-strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. The results are sensitive to the model ionosphere assumed, so future experiments should employ the widest possible range of frequencies and propagation conditions. An effective power of 90 dBW seems to be a sort of threshold that, if exceeded, results in substantial rather than small signal changes. The conclusions are based solely on joule-heating and subsequent defocusing of waves passing through caustic regions.

  17. Length of Individual Apnea Events Is Increased by Supine Position and Modulated by Severity of Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Timo Leppänen

    2016-01-01

    Full Text Available Positional obstructive sleep apnea (OSA is common among OSA patients. In severe OSA, the obstruction events are longer in supine compared to nonsupine positions. Corresponding scientific information on mild and moderate OSA is lacking. We studied whether individual obstruction and desaturation event severity is increased in supine position in all OSA severity categories and whether the severity of individual events is linked to OSA severity categories. Polygraphic recordings of 2026 patients were retrospectively analyzed. The individual apnea, and hypopnea durations and desaturation event depth, duration, and area of 526 included patients were compared between supine and nonsupine positions in different OSA severity categories. Apnea events were 6.3%, 12.5%, and 11.1% longer (p<0.001 in supine compared to nonsupine position in mild, moderate, and severe OSA categories, respectively. In moderate and severe OSA categories desaturation areas were 5.7% and 25.5% larger (p<0.001 in supine position. In both positions the individual event severity was elevated along increasing OSA severity category (p<0.05. Supine position elevates apnea duration in all and desaturation area in moderate and severe OSA severity categories. This might be more hazardous for supine OSA patients and therefore, estimation of clinical severity of OSA should incorporate also information about individual event characteristics besides AHI.

  18. Cardiovascular determinants of maximal oxygen consumption in upright and supine posture at the end of prolonged bed rest in humans.

    Science.gov (United States)

    Bringard, Aurélien; Pogliaghi, Silvia; Adami, Alessandra; De Roia, Gabriela; Lador, Frédéric; Lucini, Daniela; Pizzinelli, Paolo; Capelli, Carlo; Ferretti, Guido

    2010-06-30

    We tested the hypothesis that, after bed rest, maximal oxygen consumption ( VO₂max ) decreases more upright than supine, because of adequate cardiovascular response supine, but not upright. On 9 subjects, we determined VO₂max and maximal cardiac output (Q ) upright and supine, before and after (reambulation day upright, the following day supine) 35-day bed rest, by classical steady state protocol. Oxygen consumption, heart rate (f(H)) and stroke volume (Q(st)) were measured by a metabolic cart, electrocardiography and Modelflow from pulse pressure profiles, respectively. We computed Q as f(H) times Q(st), and systemic oxygen flow ( QaO₂) as Q. times arterial oxygen concentration, obtained after haemoglobin and arterial oxygen saturation measurements. Before bed rest, all parameters at maximal exercise were similar upright and supine. After bed rest, VO₂max was lower (pcardiovascular response (i) did not affect VO₂max supine, (ii) partially explained the VO₂max decrease upright, and (iii) caused the VO₂max differences between postures. We speculate that impaired peripheral oxygen transfer and/or utilisation may explain the VO₂max decrease supine and the fraction of VO₂max decrease upright unexplained by cardiovascular responses.

  19. Conventional Supine MRI With a Lumbar Pillow-An Alternative to Weight-bearing MRI for Diagnosing Spinal Stenosis?

    DEFF Research Database (Denmark)

    Hansen, Bjarke Brandt; Hansen, Philip; Grindsted, Jacob

    2017-01-01

    to conventional MRI were included to an additional positional MRI scan (0.25T G-Scan) performed in: (1) conventional supine, (2) standing, (3) supine with a lumbar pillow in the lower back. LSS was evaluated for each position in consensus on a 0 to 3 semi-quantitative grading scale. Independently, L2-S1 lordosis...... included. The lordosis angle increased significantly from supine to standing (3.2° CI: 1.2-5.2) and with the lumbar pillow (12.8° CI: 10.3-15.3). One-way analysis of variance (ANOVA) showed significant differences between positions (P 

  20. Reduced Oblique Effect in Children with Autism Spectrum Disorders (ASD)

    Science.gov (United States)

    Sysoeva, Olga V.; Davletshina, Maria A.; Orekhova, Elena V.; Galuta, Ilia A.; Stroganova, Tatiana A.

    2016-01-01

    People are very precise in the discrimination of a line orientation relative to the cardinal (vertical and horizontal) axes, while their orientation discrimination sensitivity along the oblique axes is less refined. This difference in discrimination sensitivity along cardinal and oblique axes is called the “oblique effect.” Given that the oblique effect is a basic feature of visual processing with an early developmental origin, its investigation in children with Autism Spectrum Disorder (ASD) may shed light on the nature of visual sensory abnormalities frequently reported in this population. We examined line orientation sensitivity along oblique and vertical axes in a sample of 26 boys with ASD (IQ > 68) and 38 typically developing (TD) boys aged 7–15 years, as well as in a subsample of carefully IQ-matched ASD and TD participants. Children were asked to detect the direction of tilt of a high-contrast black-and-white grating relative to vertical (90°) or oblique (45°) templates. The oblique effect was reduced in children with ASD as compared to TD participants, irrespective of their IQ. This reduction was due to poor orientation sensitivity along the vertical axis in ASD children, while their ability to discriminate line orientation along the oblique axis was unaffected. We speculate that this deficit in sensitivity to vertical orientation may reflect disrupted mechanisms of early experience-dependent learning that takes place during the critical period for orientation selectivity. PMID:26834540

  1. Interface Defeat of Long Rods Impacting Oblique Silicon Carbide

    Science.gov (United States)

    2011-02-01

    Test data for gold rods impacting unconfined silicon carbide targets are reported. This work focuses on the dwell phenomenon exhibited by silicon ... carbide for targets at obliquity. Experiments are presented for obliquities of 30 deg, 45 deg and 60 deg, with and without cover plates. Results are compared to normal impact.

  2. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridges crossing channel obliquely. 118.90 Section 118.90 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely....

  3. Limb blood flow - Rest and heavy exercise in sitting and supine positions in man

    Science.gov (United States)

    Greenleaf, J. E.; Montgomery, L. D.; Brock, P. J.; Van Beaumont, W.

    1979-01-01

    The objectives of the study were twofold: (1) to determine the effect of body position (hydrostatic pressure) on total blood flow in active and passive limbs at rest and after severe exercise; and (2) to further evaluate the impedance technique for measurement of blood flow. To this end, the effect of body position on the redistribution of total blood flow in active (leg) and passive (forearm) limbs during exercise was determined by measuring total limb impedance (blood flow) in five male and one female subjects in sitting and supine positions with a modified Beckman BR-100 rheograph. The results show that, at rest and after exercise, the supine position induces significantly greater flows in the leg but not in the forearm. With severe exercise, blood flows are increased in both passive and active limbs, so that there is probably no net transfer of blood volume from passive to active muscles. The advantages of the impedance technique over other methods are stressed.

  4. Bound to supine sleep: Parkinson's disease and the impact of nocturnal immobility

    OpenAIRE

    Sommerauer, M; Werth, E; Poryazova, R; Y. V. Gavrilov; Hauser, S; Valko, P O

    2015-01-01

    BACKGROUND Impaired nocturnal mobility is a well-known problem in Parkinson's disease (PD), and clinical experience suggests a predominance of supine body position during sleep. However, this assumption - and potential consequences - still awaits objective validation by a polysomnography-based and adequately controlled study. METHODS Clinical and polysomnographical analysis of 80 consecutive PD patients and 80 control subjects carefully matched for age, sex, body mass index and apnea-hypop...

  5. Arm rotated medially with supination – the ARMS variant: description of its surgical correction

    Directory of Open Access Journals (Sweden)

    Melcher Sonya E

    2009-03-01

    Full Text Available Abstract Background Patients who have suffered obstetric brachial plexus injury (OBPI have a high incidence of musculoskeletal complications stemming from the initial nerve injury. The presence of muscle imbalances and contractures leads to typical bony changes affecting the shoulder, including the SHEAR (Scapular Hypoplasia, Elevation and Rotation deformity. The SHEAR deformity commonly occurs in conjunction with Medial Rotation Contracture (MRC of the arm. OBPI also causes muscle imbalances at the level of the forearm, that lead to a fixed supination deformity (SD in a small number of patients. Both MRC and SD will cause severe functional limitations without surgical intervention. Methods Fourteen OBPI patients were diagnosed with MRC of the shoulder and SD of the forearm along with SHEAR deformity during a 16 month study period, with eight patients available to long-term follow-up (age range 2.2 – 18 years. Surgical correction of the MRC was performed as a triangle tilt or humeral osteotomy depending on the age of the child, after which, the patients were treated with a radial osteotomy to correct the fixed supination deformity. Function was assessed using the modified Mallet scale, examination of apparent supination and appearance of the extremity at rest. Results Significant functional improvements were observed in patients with surgical reconstruction. Mallet score increased by an average of 5.2 (p Conclusion The simultaneous presence of two opposing deformities in the same limb will visually offset each other at the level of the wrist and hand, giving the false impression of neutral positioning of the limb. In reality, the neutral-appearing position of the hand indicates a fixed supination posture of the forearm in the face of a medial rotation contracture of the shoulder. Both of these deformities require surgical attention, and the presence of concurrent MRC and SD should be monitored for in OBPI patients.

  6. Mechanical stimulation of the foot sole in a supine position for ground reaction force simulation

    OpenAIRE

    2014-01-01

    Background:\\ud To promote early rehabilitation of walking, gait training can start even when patients are on bed rest. Supine stepping in the early phase after injury is proposed to maximise the beneficial effects of gait restoration. In this training paradigm, mechanical loading on the sole of the foot is required to mimic the ground reaction forces that occur during overground walking. A pneumatic shoe platform was developed to produce adjustable forces on the heel and the forefoot with an ...

  7. MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

    OpenAIRE

    Francesca Iacobellis; Antonio Brillantino; Adolfo Renzi; Luigi Monaco; Nicola Serra; Beatrice Feragalli; Aniello Iacomino; Luca Brunese; Salvatore Cappabianca

    2016-01-01

    Introduction. Functional disorders of the pelvic floor represent have a significant impact on the quality of life. The advent of open-configuration systems allowed for the evaluation of defecation with MR imaging in sitting position. The purpose of the present study is to compare the results of static and dynamic pelvic MR performed in supine position versus sitting position, using a new MR prototype machine, in the diagnosis of pelvic floor descent. Materials and Methods. Thirty-one patients...

  8. The effect of supine versus upright patient positioning on inferior vena cava metrics.

    Science.gov (United States)

    Panebianco, Nova L; Shofer, Frances; Cheng, Alfred; Fischer, Jonathan; Cody, Kenneth; Dean, Anthony J

    2014-11-01

    Ultrasound of the inferior vena cava (IVC) is a noninvasive and rapidly obtainable method of intravascular volume assessment; however not all patients can lie supine for this procedure. In this study we assess whether patient positioning affects IVC diameter metrics. This was a prospective convenience sample of patients in an in-patient dialysis unit at an urban tertiary care center. IVC metrics taken in the supine patient, and then at 45o semi-upright position, pre and post dialysis. Measurements were taken in M-mode in longitudinal plane roughly 2 cm below the level of the diaphragm. IVC-maximum and IVC-minimum diameter measurements were used to determine the IVC collapse index (IVC Max - IVC Min)/IVC Max). Statistics such as means, frequencies and percentages, intraclass correlation coefficient and Bland Altman summary statistics were calculated. Forty-five patients were enrolled. Average age was 57 years, 69% were male, 73% were African American, 82% had hypertension, 42% had diabetes. There was good to excellent agreement between supine and upright IVC measurements. Both the IVC minimum and maximum measurements had similar coefficient correlation (ri) measurements (0.917 and 0.890 respectively), whereas agreement in the collapse index was lower (ri = 0.813). Bland Altman analysis demonstrated excellent agreement and small 95% limits of agreement (±6 mm) with minimal mean bias for both the minimum and maximum measurements. IVC metrics do not change significantly based on patient position. For those patients who are unable to lay completely supine, a semi-upright measurement of the IVC for volume status may be an accurate alternative. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. 617-R2 Mineralocorticoid Receptor Activation Contributes to the Supine Hypertension of Autonomic Failure

    Science.gov (United States)

    Arnold, Amy C.; Okamoto, Luis E.; Gamboa, Alfredo; Black, Bonnie K.; Raj, Satish R.; Elijovich, Fernando; Robertson, David; Shibao, Cyndya A.; Biaggioni, Italo

    2016-01-01

    Primary autonomic failure is characterized by disabling orthostatic hypotension; but at least half of these patients have paradoxical supine hypertension. Renin-angiotensin mechanisms were not initially thought to contribute to this hypertension, as plasma renin activity is often undetectable in autonomic failure. Plasma aldosterone levels are normal, however, and we recently showed that plasma angiotensin II is elevated and acts at AT1 receptors to contribute to hypertension in these patients. Since aldosterone and angiotensin II can also bind mineralocorticoid receptors to elevate blood pressure, we hypothesized that mineralocorticoid receptor activation plays a role in the hypertension of autonomic failure. To test this hypothesis, we determined the acute effects of the mineralocorticoid receptor antagonist eplerenone (50 mg, oral) versus placebo on supine blood pressure in a randomized, double blind, crossover study. Medications were given at 8:00 PM with blood pressure recorded every 2 hours for 12 hours. Ten primary autonomic failure patients with supine hypertension completed this study (7 Pure Autonomic Failure, 2 Multiple System Atrophy, 1 Parkinson’s disease; 7 male; 70±2 years of age). Eplerenone maximally reduced supine systolic blood pressure by 32±6 mmHg at 8 hours after administration (vs. 8±10 mmHg placebo, p=0.016), with no effect on nocturia (12-hour urine volume: 985±134 placebo vs. 931±94 ml eplerenone, p=0.492; nocturnal weight loss: −1.19±0.15 placebo vs. −1.18±0.15 kg eplerenone, p=0.766). These findings suggest that inappropriate mineralocorticoid receptor activation contributes to the hypertension of autonomic failure, likely independent of canonical mineralocorticoid effects, and provides rationale for use of eplerenone in these patients. PMID:26644241

  10. Comparison of the Effects of Seated, Supine, and Walking Interset Rest Strategies on Work Rate.

    Science.gov (United States)

    Ouellette, Kristen A; Brusseau, Timothy A; Davidson, Lance E; Ford, Candus N; Hatfield, Disa L; Shaw, Janet M; Eisenman, Patricia A

    2016-12-01

    Ouellette, KA, Brusseau, TA, Davidson, LE, Ford, CN, Hatfield, DL, Shaw, JM, and Eisenman, PA. Comparison of the effects of seated, supine, and walking interset rest strategies on work rate. J Strength Cond Res 30(12): 3396-3404, 2016-The idea that an upright posture should be maintained during the interset rest periods of training sessions is pervasive. The primary aim of this study was to determine differences in work rate associated with 3 interset rest strategies. Male and female members of the CrossFit community (male n = 5, female n = 10) were recruited to perform a strenuous training session designed to enhance work capacity that involved both cardiovascular and muscular endurance exercises. The training session was repeated on 3 separate occasions to evaluate 3 interset rest strategies, which included lying supine on the floor, sitting on a flat bench, and walking on a treadmill (0.67 m·s). Work rate was calculated for each training session by summing session joules of work and dividing by the time to complete the training session (joules of work per second). Data were also collected during the interset rest periods (heart rate [HR], respiratory rate [RR], and volume of oxygen consumed) and were used to explain why one rest strategy may positively impact work rate compared with another. Statistical analyses revealed significant differences (p ≤ 0.05) between the passive and active rest strategies, with the passive strategies allowing for improved work rate (supine = 62.77 ± 7.32, seated = 63.66 ± 8.37, and walking = 60.61 ± 6.42 average joules of work per second). Results also suggest that the passive strategies resulted in superior HR, RR, and oxygen consumption recovery. In conclusion, work rate and physiological recovery were enhanced when supine and seated interset rest strategies were used compared with walking interset rest.

  11. Mineralocorticoid Receptor Activation Contributes to the Supine Hypertension of Autonomic Failure.

    Science.gov (United States)

    Arnold, Amy C; Okamoto, Luis E; Gamboa, Alfredo; Black, Bonnie K; Raj, Satish R; Elijovich, Fernando; Robertson, David; Shibao, Cyndya A; Biaggioni, Italo

    2016-02-01

    Primary autonomic failure is characterized by disabling orthostatic hypotension, but at least half of these patients have paradoxical supine hypertension. Renin-angiotensin mechanisms were not initially thought to contribute to this hypertension because plasma renin activity is often undetectable in autonomic failure. Plasma aldosterone levels are normal, however, and we recently showed that plasma angiotensin II is elevated and acts at AT1 (angiotensin type 1) receptors to contribute to hypertension in these patients. Because aldosterone and angiotensin II can also bind mineralocorticoid receptors to elevate blood pressure, we hypothesized that mineralocorticoid receptor activation plays a role in the hypertension of autonomic failure. To test this hypothesis, we determined the acute effects of the mineralocorticoid receptor antagonist eplerenone (50 mg, oral) versus placebo on supine blood pressure in a randomized, double-blind, crossover study. Medications were given at 8:00 pm with blood pressure recorded every 2 hours for 12 hours. Ten primary autonomic failure patients with supine hypertension completed this study (7 pure autonomic failure, 2 multiple system atrophy, 1 parkinson's disease; 7 male; 70±2 years of age). Eplerenone maximally reduced supine systolic blood pressure by 32±6 mm Hg at 8 hours after administration (versus 8±10 mm Hg placebo, P=0.016), with no effect on nocturia (12-hour urine volume: 985±134 mL placebo versus 931±94 mL eplerenone, P=0.492; nocturnal weight loss: -1.19±0.15 kg placebo versus -1.18±0.15 kg eplerenone, P=0.766). These findings suggest that inappropriate mineralocorticoid receptor activation contributes to the hypertension of autonomic failure, likely independent of canonical mineralocorticoid effects, and provides rationale for use of eplerenone in these patients.

  12. Bow and Oblique Shock Formation in Soap Film

    Science.gov (United States)

    Kim, Ildoo; Mandre, Shreyas; Sane, Aakash

    2015-11-01

    In recent years, soap films have been exploited primarily to approximate two-dimensional flows while their three-dimensional character is relatively unattended. An example of the three-dimensional character of the flow in a soap film is the observed Marangoni shock wave when the flow speed exceeds the wave speed. In this study, we investigated the formation of bow and oblique shocks in soap films generated by wedges with different deflection angles. When the wedge deflection angle is small and the film flows fast, oblique shocks are observed. When the oblique shock cannot exists, bow shock is formed upstream the wedge. We characterized the oblique shock angle as a function of the wedge deflection angle and the flow speed, and we also present the criteria for transition between bow and oblique Marangoni shocks in soap films.

  13. Obliquity Variability of a Potentially Habitable Early Venus

    CERN Document Server

    Barnes, Jason W; Lissauer, Jack J; Chambers, John; Hedman, Matthew M

    2016-01-01

    Venus currently rotates slowly, with its spin controlled by solid-body and atmospheric thermal tides. However, conditions may have been far different 4 billion years ago, when the Sun was fainter and most of the carbon within Venus could have been in solid form, implying a low-mass atmosphere. We investigate how the obliquity would have varied for a hypothetical rapidly rotating Early Venus. The obliquity variation structure of an ensemble of hypothetical Early Venuses is simpler than that Earth would have if it lacked its large Moon (Lissauer et al., 2012), having just one primary chaotic regime at high prograde obliquities. We note an unexpected long-term variability of up to $\\pm7^\\circ$ for retrograde Venuses. Low-obliquity Venuses show very low total obliquity variability over billion-year timescales -- comparable to that of the real Moon-influenced Earth.

  14. Supine changes in lung function correlate with chronic respiratory failure in myotonic dystrophy patients.

    Science.gov (United States)

    Poussel, Mathias; Kaminsky, Pierre; Renaud, Pierre; Laroppe, Julien; Pruna, Lelia; Chenuel, Bruno

    2014-03-01

    Quality of life and prognosis of patients with myotonic dystrophy type 1 (MD1) often depend on the degree of lung function impairment. This study was designed to assess the respective prevalence of ventilatory restriction, hypoxaemia and hypercapnia in MD1 patients and to determine whether postural changes in lung function could contribute to the early diagnosis of poor respiratory outcome. Fifty-eight patients (42.6±12.9 years) with MD1 were prospectively evaluated from April 2008 to June 2010 to determine their supine and upright lung function and arterial blood gases. The prevalence of ventilatory restriction was 36% and increased with the severity of muscular disability (from 7.7% to 70.6%). The prevalence of hypoxaemia and hypercapnia was 37.9% and 25.9%, respectively. Multiple regression analysis showed that the supine fall in FEV1 was the only variable associated with ventilatory restriction, hypoxaemia and hypercapnia. Our data indicate that supine evaluation of lung function could be helpful to predict poor respiratory outcome, which is closely correlated with hypoxaemia and/or hypercapnia.

  15. Supinator Extender (SUE): a pneumatically actuated robot for forearm/wrist rehabilitation after stroke.

    Science.gov (United States)

    Allington, James; Spencer, Steven J; Klein, Julius; Buell, Meghan; Reinkensmeyer, David J; Bobrow, James

    2011-01-01

    The robot described in this paper, SUE (Supinator Extender), adds forearm/wrist rehabilitation functionality to the UCI BONES exoskeleton robot and to the ArmeoSpring rehabilitation device. SUE is a 2-DOF serial chain that can measure and assist forearm supination-pronation and wrist flexion-extension. The large power to weight ratio of pneumatic actuators allows SUE to achieve the forces needed for rehabilitation therapy while remaining lightweight enough to be carried by BONES and ArmeoSpring. Each degree of freedom has a range of 90 degrees, and a nominal torque of 2 ft-lbs. The cylinders are mounted away from the patient's body on the lateral aspect of the arm. This is to prevent the danger of a collision and maximize the workspace of the arm robot. The rotation axis used for supination-pronation is a small bearing just below the subject's wrist. The flexion-extension motion is actuated by a cantilevered pneumatic cylinder, which allows the palm of the hand to remain open. Data are presented that demonstrate the ability of SUE to measure and cancel forearm/wrist passive tone, thereby extending the active range of motion for people with stroke.

  16. Magnitudes of muscle activation of spine stabilizers, gluteals, and hamstrings during supine bridge to neutral position.

    Science.gov (United States)

    Youdas, James W; Hartman, James P; Murphy, Brooke A; Rundle, Ashley M; Ugorowski, Jenna M; Hollman, John H

    2015-01-01

    The aim of this study was to compare the magnitude of selective core muscle activation during supine bridging to neutral exercises (three on a stable and three on an unstable surface). Surface EMG analysis was performed on the lumbar multifidus, gluteus medius, gluteus maximus, and hamstrings from 13 male and 13 female subjects. Lumbar multifidus recruitment was not influenced by exercise or condition and ranged between 29.2 and 35.9% of maximum voluntary isometric contraction (MVIC). Peak gluteus medius activation (42.0% MVIC) occurred in unstable single-leg bridge. Maximum recruitment of gluteus maximus (32.6% MVIC) appeared during stable single-leg bridge. Peak hamstring activation (59.6% MVIC) occurred during stable double-leg hamstring curl. Regardless of condition, hamstrings demonstrated high (51.9-59.6% MVIC) muscle recruitment during double-leg hamstring curls compared with the single-leg bridge or double-leg bridge. Various supine bridging to neutral exercises activated the hamstrings at levels conducive to strengthening, whereas recruitment of lumbar multifidus, gluteus medius, and gluteus maximus promoted endurance training. Clinically, we were unable to conclude the unstable support surface was preferable to the stable surface for boosting muscle recruitment of spine stabilizers, gluteals, and hamstring muscles during supine bridge to neutral position.

  17. Association between nocturnal/supine hypertension and restless legs syndrome in patients with Parkinson's disease.

    Science.gov (United States)

    Oh, Yoon-Sang; Kim, Joong-Seok; Park, In-Seok; Song, In-Uk; Son, Young-Min; Park, Jeong-Wook; Yang, Dong-Won; Kim, Hee-Tae; Lee, Kwang-Soo

    2014-09-15

    Autonomic disturbances and sleep problems are common non-motor symptoms in patients with Parkinson's disease (PD). Orthostatic hypotension, supine hypertension (SH), and nocturnal hypertension (NH) are inter-related in patients with PD. These abnormalities might be associated with restless legs syndrome (RLS), which occurs predominantly at rest or during sleep. Few reports have suggested an association between circadian blood pressure disturbances and RLS in the general population. We evaluated the relationship between neurocardiovascular blood pressure alterations and RLS in patients with early PD. A total of 225 patients, newly diagnosed with PD, were included in the study. RLS was diagnosed by the International Restless Legs Syndrome Study Group's diagnostic criteria. Orthostatic vital signs and ambulatory 24-h blood pressure were monitored and recorded. Thirty-six (16.0%) participating patients had RLS. SH and NH were more frequent in the PD+RLS group than in the group without RLS. Supine blood pressure, orthostatic decline in blood pressure, nighttime blood pressure, and the standard deviation of systolic blood pressure were significantly higher in the PD+RLS group than in the group without RLS. RLS is related to nocturnal/supine hypertension and blood pressure fluctuations, suggesting a neuropathological association between autonomic and sleep dysfunctions in patients with PD. RLS may be a determinant of neurocirculatory abnormalities. Detecting and effectively treating RLS might slow the rate of pressure-related neurocardiovascular damage in dysautonomic patients with PD. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. The Role of Rift Obliquity During Pangea Fragmentation

    Science.gov (United States)

    Brune, S.; Butterworth, N. P.; Williams, S.; Müller, D.

    2014-12-01

    Does supercontinent break-up follow specific laws? What parameters control the success and the failure of rift systems? Recent analytical and geodynamic modeling suggests that oblique rifting is energetically preferred over orthogonal rifting. This implies that during rift competition, highly oblique branches proceed to break-up while less oblique ones become inactive. These models predict that the relative motion of Earth's continents during supercontinent break-up is affected by the orientation and shape of individual rift systems. Here, we test this hypothesis based on latest plate tectonic reconstructions. Using PyGPlates, a recently developed Python library that allows script-based access to the plate reconstruction software GPlates, we quantify rift obliquity, extension velocity and their temporal evolution for continent-scale rift systems of the past 200 Myr. Indeed we find that many rift systems contributing to Pangea fragmentation involved strong rift obliquity. East and West Gondwana for instance split along the East African coast with a mean obliquity of 55° (measured as the angle between local rift trend normal and extension direction). While formation of the central and southern South Atlantic segment involved a low obliquity of 10°, the Equatorial Atlantic opened under a high angle of 60°. Rifting between Australia and Antarctica involved two stages with 25° prior to 100 Ma followed by 50° obliquity and distinct increase of extension velocity. Analyzing the entire passive margin system that formed during Pangea breakup, we find a mean obliquity of 40°, with a standard deviation of 20°. Hence 50% of these margins formed with an angle of 40° or more. Considering that many conceptual models of rifting and passive margin formation assume 2D deformation, our study quantifies the degree to which such 2D models are globally applicable, and highlights the importance of 3D models where oblique rifting is the dominant mode of deformation.

  19. Calibration Procedures on Oblique Camera Setups

    Science.gov (United States)

    Kemper, G.; Melykuti, B.; Yu, C.

    2016-06-01

    Beside the creation of virtual animated 3D City models, analysis for homeland security and city planning, the accurately determination of geometric features out of oblique imagery is an important task today. Due to the huge number of single images the reduction of control points force to make use of direct referencing devices. This causes a precise camera-calibration and additional adjustment procedures. This paper aims to show the workflow of the various calibration steps and will present examples of the calibration flight with the final 3D City model. In difference to most other software, the oblique cameras are used not as co-registered sensors in relation to the nadir one, all camera images enter the AT process as single pre-oriented data. This enables a better post calibration in order to detect variations in the single camera calibration and other mechanical effects. The shown sensor (Oblique Imager) is based o 5 Phase One cameras were the nadir one has 80 MPIX equipped with a 50 mm lens while the oblique ones capture images with 50 MPix using 80 mm lenses. The cameras are mounted robust inside a housing to protect this against physical and thermal deformations. The sensor head hosts also an IMU which is connected to a POS AV GNSS Receiver. The sensor is stabilized by a gyro-mount which creates floating Antenna -IMU lever arms. They had to be registered together with the Raw GNSS-IMU Data. The camera calibration procedure was performed based on a special calibration flight with 351 shoots of all 5 cameras and registered the GPS/IMU data. This specific mission was designed in two different altitudes with additional cross lines on each flying heights. The five images from each exposure positions have no overlaps but in the block there are many overlaps resulting in up to 200 measurements per points. On each photo there were in average 110 well distributed measured points which is a satisfying number for the camera calibration. In a first step with the help of

  20. CALIBRATION PROCEDURES ON OBLIQUE CAMERA SETUPS

    Directory of Open Access Journals (Sweden)

    G. Kemper

    2016-06-01

    Full Text Available Beside the creation of virtual animated 3D City models, analysis for homeland security and city planning, the accurately determination of geometric features out of oblique imagery is an important task today. Due to the huge number of single images the reduction of control points force to make use of direct referencing devices. This causes a precise camera-calibration and additional adjustment procedures. This paper aims to show the workflow of the various calibration steps and will present examples of the calibration flight with the final 3D City model. In difference to most other software, the oblique cameras are used not as co-registered sensors in relation to the nadir one, all camera images enter the AT process as single pre-oriented data. This enables a better post calibration in order to detect variations in the single camera calibration and other mechanical effects. The shown sensor (Oblique Imager is based o 5 Phase One cameras were the nadir one has 80 MPIX equipped with a 50 mm lens while the oblique ones capture images with 50 MPix using 80 mm lenses. The cameras are mounted robust inside a housing to protect this against physical and thermal deformations. The sensor head hosts also an IMU which is connected to a POS AV GNSS Receiver. The sensor is stabilized by a gyro-mount which creates floating Antenna –IMU lever arms. They had to be registered together with the Raw GNSS-IMU Data. The camera calibration procedure was performed based on a special calibration flight with 351 shoots of all 5 cameras and registered the GPS/IMU data. This specific mission was designed in two different altitudes with additional cross lines on each flying heights. The five images from each exposure positions have no overlaps but in the block there are many overlaps resulting in up to 200 measurements per points. On each photo there were in average 110 well distributed measured points which is a satisfying number for the camera calibration. In a first

  1. Wafer scale oblique angle plasma etching

    Energy Technology Data Exchange (ETDEWEB)

    Burckel, David Bruce; Jarecki, Jr., Robert L.; Finnegan, Patrick Sean

    2017-05-23

    Wafer scale oblique angle etching of a semiconductor substrate is performed in a conventional plasma etch chamber by using a fixture that supports a multiple number of separate Faraday cages. Each cage is formed to include an angled grid surface and is positioned such that it will be positioned over a separate one of the die locations on the wafer surface when the fixture is placed over the wafer. The presence of the Faraday cages influences the local electric field surrounding each wafer die, re-shaping the local field to be disposed in alignment with the angled grid surface. The re-shaped plasma causes the reactive ions to follow a linear trajectory through the plasma sheath and angled grid surface, ultimately impinging the wafer surface at an angle. The selected geometry of the Faraday cage angled grid surface thus determines the angle at with the reactive ions will impinge the wafer.

  2. MIX and Instability Growth from Oblique Shock

    Energy Technology Data Exchange (ETDEWEB)

    Molitoris, J D; Batteux, J D; Garza, R G; Tringe, J W; Souers, P C; Forbes, J W

    2011-07-22

    We have studied the formation and evolution of shock-induced mix resulting from interface features in a divergent cylindrical geometry. In this research a cylindrical core of high-explosive was detonated to create an oblique shock wave and accelerate the interface. The interfaces studied were between the high-explosive/aluminum, aluminum/plastic, and finally plastic/air. Pre-emplaced surface features added to the aluminum were used to modify this interface. Time sequence radiographic imaging quantified the resulting instability formation from the growth phase to over 60 {micro}s post-detonation. Thus allowing the study of the onset of mix and evolution to turbulence. The plastic used here was porous polyethylene. Radiographic image data are compared with numerical simulations of the experiments.

  3. Partial Oblique Projection Learning for Optimal Generalization

    Institute of Scientific and Technical Information of China (English)

    LIU Benyong; ZHANG Jing

    2004-01-01

    In practice,it is necessary to implement an incremental and active learning for a learning method.In terms of such implementation,this paper shows that the previously discussed S-L projection learning is inappropriate to constructing a family of projection learning,and proposes a new version called partial oblique projection (POP) learning.In POP learning,a function space is decomposed into two complementary subspaces,so that functions belonging to one of the subspaces can be completely estimated in noiseless case;while in noisy case,the dispersions are set to be the smallest.In addition,a general form of POP learning is presented and the results of a simulation are given.

  4. Fused oblique incidence reflectometry and confocal fluorescence microscopy

    Science.gov (United States)

    Risi, Matthew D.; Rouse, Andrew R.; Gmitro, Arthur F.

    2011-03-01

    Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure, but relies on exogenous fluorophores, has a relatively limited penetration depth (100 μm) and field of view (700 μm), and produces a high rate of detailed information to the user. A new catheter based multi-modal system has been designed that combines confocal imaging and oblique incidence reflectometry (OIR), which is a non-invasive method capable of rapidly extracting tissue absorption, μa, and reduced scattering, μ's, spectra from tissue. The system builds on previous developments of a custom slit-scan multi-spectral confocal microendoscope and is designed to rapidly switch between diffuse spectroscopy and confocal fluorescence imaging modes of operation. An experimental proof-of-principle catheter has been developed that consists of a fiber bundle for traditional confocal fluorescence imaging and a single OIR source fiber which is manually redirected at +/- 26 degrees. Diffusely scattered light from each orientation of the source fiber is collected via the fiber bundle, with a frame of data representing spectra collected at a range of distances from the OIR source point. Initial results with intralipid phantoms show good agreement to published data over the 550-650 nm spectral range. We successfully imaged and measured the optical properties of rodent cardiac muscle.

  5. Lightcurves of Stars & Exoplanets: Estimating Inclination, Obliquity, and Albedo

    CERN Document Server

    Cowan, Nicolas B; Haggard, Hal M

    2013-01-01

    [Abridged] It is possible to determine a star or planet's brightness markings by analyzing its disk-integrated brightness variations, in either thermal or reflected light. We compute the "harmonic lightcurves" resulting from spherical harmonic maps of intensity or albedo. These convolutions often contain a nullspace: a class of non-zero maps that have no lightcurve signature. We derive harmonic thermal lightcurves for both equatorial and inclined observers. The nullspace for these two viewing geometries is significantly different, with odd modes being present in the latter case, but not the former. We therefore suggest that the Fourier spectrum of a thermal lightcurve is sufficient to determine the orbital inclination of non-transiting short-period planets, the rotational inclination of stars and brown dwarfs, and the obliquity of directly imaged planets. In the best-case scenario of a nearly edge-on rotator, factor-of-two measurements of the amplitudes of odd modes in the thermal lightcurve provide an inclin...

  6. Comparison of Radiation Treatment Plans for Breast Cancer between 3D Conformal in Prone and Supine Positions in Contrast to VMAT and IMRT Supine Positions

    Science.gov (United States)

    Bejarano Buele, Ana Isabel

    The treatment regimen for breast cancer patients typically involves Whole Breast Irradiation (WBI). The coverage and extent of the radiation treatment is dictated by location of tumor mass, breast tissue distribution, involvement of lymph nodes, and other factors. The current standard treatment approach used at our institution is a 3D tangential beam geometry, which involves two fields irradiating the breast, or a four field beam arrangement covering the whole breast and involved nodes, while decreasing the dose to organs as risk (OARs) such as the lung and heart. The coverage of these targets can be difficult to achieve in patients with unfavorable thoracic geometries, especially in those cases in which the planning target volume (PTV) is extended to the chest wall. It is a well-known fact that exposure of the heart to ionizing radiation has been proved to increase the subsequent rate of ischemic heart disease. In these cases, inverse planned treatments have become a proven alternative to the 3D approach. The goal of this research project is to evaluate the factors that affect our current techniques as well as to adapt the development of inverse modulated techniques for our clinic, in which breast cancer patients are one of the largest populations treated. For this purpose, a dosimetric comparison along with the evaluation of immobilization devices was necessary. Radiation treatment plans were designed and dosimetrically compared for 5 patients in both, supine and prone positions. For 8 patients, VMAT and IMRT plans were created and evaluated in the supine position. Skin flash incorporation for inverse modulated plans required measurement of the surface dose as well as an evaluation of breast volume changes during a treatment course. It was found that prone 3D conformal plans as well as the VMAT and IMRT plans are generally superior in sparing OARs to supine plans with comparable PTV coverage. Prone setup leads to larger shifts in breast volume as well as in

  7. The Effect of Acute Superior Oblique Palsy on Torsional Optokinetic Nystagmus in Monkeys

    Science.gov (United States)

    Shan, Xiaoyan; Tian, Jing; Ying, Howard S.; Walker, Mark F.; Guyton, David; Quaia, Christian; Optican, Lance M.; Tamargo, Rafael J.; Zee, David S.

    2008-01-01

    Purpose To investigate the effects of acquired superior oblique palsy (SOP) and corrective strabismus surgery on torsional optokinetic nystagmus (tOKN) in monkeys. Methods The trochlear nerve was severed intracranially in two rhesus monkeys (M1 and M2). For each monkey, more than 4 months after the SOP, the ipsilateral inferior oblique muscle was denervated and extirpated. For M2, 4 months later, the contralateral inferior rectus muscle was recessed by 2 mm. tOKN was elicited during monocular viewing of a rotating stimulus that was rear projected onto a screen 43.5 cm in front of the animal. Angular rotation of the stimulus about the center was 40 deg/s clockwise or counterclockwise. Results The main findings after trochlear nerve sectioning were (1) the amplitude and peak velocity of torsional quick and slow phases of the paretic eye was less than that in the normal eye for both intorsion and extorsion, and (2) the vertical motion of the paretic eye increased during both torsional slow and quick phases. After corrective inferior oblique surgery, both of these effects were even greater. Conclusions Acquired SOP and corrective inferior oblique–weakening surgery create characteristic patterns of change in tOKN that reflect alterations in the dynamic properties of the extraocular muscles involved in eye torsion. tOKN also provides information complementary to that provided by the traditional Bielschowsky head-tilt test and potentially can help distinguish among different causes of vertical ocular misalignment. PMID:18385059

  8. Length of Individual Apnea Events Is Increased by Supine Position and Modulated by Severity of Obstructive Sleep Apnea

    OpenAIRE

    Timo Leppänen; Juha Töyräs; Anu Muraja-Murro; Salla Kupari; Pekka Tiihonen; Esa Mervaala; Antti Kulkas

    2016-01-01

    Positional obstructive sleep apnea (OSA) is common among OSA patients. In severe OSA, the obstruction events are longer in supine compared to nonsupine positions. Corresponding scientific information on mild and moderate OSA is lacking. We studied whether individual obstruction and desaturation event severity is increased in supine position in all OSA severity categories and whether the severity of individual events is linked to OSA severity categories. Polygraphic recordings of 2026 patients...

  9. Obliquity Variations of a Potentially Habitable Early Venus

    Science.gov (United States)

    Barnes, Jason W.; Quarles, Billy L.; Lissauer, Jack J.; Chambers, John E.; Hedman, Matthew M.

    2016-06-01

    Planetary obliquity (axis tilt) and its variations can have strong effects on climate. Earth's glacial cycles, for instance, are driven in part by variations in Earth's obliquity of order ±1.5o. Direct observations of the obliquity of habitable zone rocky exoplanets is likely a long way off. Therefore we investigate the long-term obliquity variations expected for Venus as it might have existed in the early Solar System. Although Venus presently rotates slowly owing to tidal despinning, it must have had a different rotation state early in Solar System history. At the same time, Venus was the Solar System's habitable zone under a Faint Young Sun. Because of our extensive knowledge of the Solar System's constituents, we therefore use Venus' obliquity variations as a proxy for what we might find in exoplanetary systems. We find that the obliquity variation structure is simpler for early Venus than it would be for a Moonless Earth, but that large, chaotic variability can occur for high initial obliquity values. Interestingly retrograde-rotating Venuses show higher variability than do retrograde Moonless Earths.

  10. Obliquity evolution of the minor satellites of Pluto and Charon

    Science.gov (United States)

    Quillen, Alice C.; Nichols-Fleming, Fiona; Chen, Yuan-Yuan; Noyelles, Benoît

    2017-09-01

    New Horizons mission observations show that the small satellites Styx, Nix, Kerberos and Hydra, of the Pluto-Charon system, have not tidally spun-down to near synchronous spin states and have high obliquities with respect to their orbit about the Pluto-Charon binary (Weaver, 2016). We use a damped mass-spring model within an N-body simulation to study spin and obliquity evolution for single spinning non-round bodies in circumbinary orbit. Simulations with tidal dissipation alone do not show strong obliquity variations from tidally induced spin-orbit resonance crossing and this we attribute to the high satellite spin rates and low orbital eccentricities. However, a tidally evolving Styx exhibits intermittent obliquity variations and episodes of tumbling. During a previous epoch where Charon migrated away from Pluto, the minor satellites could have been trapped in orbital mean motion inclination resonances. An outward migrating Charon induces large variations in Nix and Styx's obliquities. The cause is a commensurability between the mean motion resonance frequency and the spin precession rate of the spinning body. As the minor satellites are near mean motion resonances, this mechanism could have lifted the obliquities of all four minor satellites. The high obliquities need not be primordial if the minor satellites were at one time captured into mean motion resonances.

  11. Pairs of oblique duals in spaces of periodic functions

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2010-01-01

    We construct non-tight frames in finite-dimensional spaces consisting of periodic functions. In order for these frames to be useful in practice one needs to calculate a dual frame; while the canonical dual frame might be cumbersome to work with, the setup presented here enables us to obtain...... explicit constructions of some particularly convenient oblique duals. We also provide explicit oblique duals belonging to prescribed spaces different from the space where we obtain the expansion. In particular this leads to oblique duals that are trigonometric polynomials....

  12. Acquired Brown Syndrome Treated With Traction of Superior Oblique Tendon.

    Science.gov (United States)

    Shin, Kwang Hoon; Paik, Hae Jung; Chi, Mijung

    2016-03-01

    Brown syndrome is a rare strabismic disease characterized by a limited elevation in adduction of the eye. The lengthening/weakening of superior oblique muscle is the main way of surgical intervention for this disease. A 7-year-old boy was diagnosed as having acquired Brown syndrome in his right eye after injury in his face. We experienced successful release of this Brown syndrome through mere pulling outward of superior oblique tendon during surgical exploration. We briefly discuss why this manipulation of superior oblique tendon that we performed was successful.

  13. Klein tunneling through an oblique barrier in graphene ribbons

    CERN Document Server

    Oh, J H

    2010-01-01

    We study a transmission coefficient of graphene nanoribbons with a top gate which acts as an oblique barrier. Using a Green function method based on the Dirac-like equation, scattering among transverse modes due to the oblique barrier is taken into account numerically. In contrast to the 2-dimensional graphene sheet, we find that the pattern of transmission in graphene ribbons depends strongly on the electronic structure in the region of the barrier. Consequently, irregular structures in the transmission coefficient are predicted while perfect transmission is still calculated in the case of metallic graphene independently of angle and length of the oblique barrier.

  14. Direct decision making vs. oblique decision making: which is right?

    Science.gov (United States)

    Kerfoot, Karlene M

    2011-01-01

    The complexity of health care environments is far too complicated for solutions to be developed by a small group or isolated upper managers. This direct leadership approach often fails. Leaders who use a more oblique approach focusing on areas such as long-term economic value, creating significant benefits for the wider community, and building robust social capital within the company are successful. Obliquity leadership is very appropriate for health care because of its constantly changing environment. Obliquity leadership and shared governance are great partners in reaching higher levels of involvement and high performance.

  15. Periodical Plasma Structures Controlled by Oblique Magnetic Field

    CERN Document Server

    Schweigert, Irina

    2016-01-01

    The propulsion type plasma in oblique external magnetic field is studied in 2D3V PIC MCC simulations. A periodical structure with maxima of electron and ion densities appears with an increase of an obliqueness of magnetic field. These ridges of electron and ion densities are aligned with the magnetic field vector and shifted relative each other. As a result the two-dimensional double-layers structure forms in cylindrical plasma chamber. The ion and electron currents on the side wall are essential modulated by the oblique magnetic field.

  16. Effect of modified inferior oblique anterior transposition on dissociated vertical strabismus patients with inferior oblique muscle hyperfunction

    Directory of Open Access Journals (Sweden)

    Xi-Lang Wang

    2017-02-01

    Full Text Available AIM: To investigate the effect of anterior transposition of inferior oblique muscle on the treatment of dissociated vertical deviation(DVDin children with inferior oblique overaction(IOOAand unequal inferior oblique transposition of the treatment of IOOA with the eyes of the asymmetry of DVD efficacy, associated with the lower oblique hyperfunction DVD patients to provide more effective treatment. METHODS: Eighty patients with hyperfunction who were treated in our hospital from January 2014 to December 2015 were randomly selected and treated with anterior transposition of inferior oblique muscle. Patients were followed up for 1 to 30mo. We compared the vertical incline at the original incline from far(5m, near(33cmdistance and IOOA degree before and after operations, and the correlation between the two. We also compared the vertical incline at the original incline from far(5m, near(33cmdistance and IOOA degree before and after operations in 30 eyes(20 patientswith bilateral asymmetry DVD and IOOA who received unequal inferior oblique transposition. The incidence of antielevation syndrome(AESwas observed after operations. RESULTS: The mean prism diopters(PDat 5m before operations was 19.5±0.15, the average PD after operations was 3.5±0.18, at 5m the original incline was 16±0.21PD. The mean PD at 33cm was 18.6±0.20 before operation, 4.5±0.26 after operations, and 14.1±0.16 at 33cm the original incline, the difference was statistically significant(Pr=0.554, Pr=0.454, P PPCONCLUSION: Anterior transposition of the inferior oblique muscle has a good therapeutic effect on isolated vertical strabismus patients with inferior oblique hyperfunction. While the incidence of postoperative AES is low in patients received unequal inferior oblique muscle transposition.

  17. Relationship between skull asymmetry and CT findings. Supine head position preference and brain damage

    Energy Technology Data Exchange (ETDEWEB)

    Yamori, Yuriko; Yuge, Mariko; Kanda, Toyoko; Ashida, Hiromi; Fukase, Hiroshi

    1987-07-01

    In order to clarify the relationship between brain damage and skull asymmetry or supine head position preference, we classified CT findings of 330 cases with cerebral palsy or risk of motor disturbance into 6 groups according to skull shape. Those were severe (I, n = 37) and mild (II, n = 114) grades in the right occipital flatness, severe (III, n = 34) and mild (IV, n = 58) grades in the left occipital flatness, long skull with temporal flatness (V, n = 33) and symmetric round skull (control, n = 54). It was considered that the asymmetry of cortical atrophy in appearance was formed physicaly by skull asymmetry but that the asymmetric dilatation in appearance of lateral ventricle was related to the asymmetry of brain damage. The severity and the asymmetry of brain damage were tend to increase the grade of skull asymmetry. The incidence of cases with the right occipital flatness was 1.6 times more frequently than the left sided. The incidence of cases whose left (lateral) ventricle was larger than the right was 4.1 times more than the cases whose right ventricle was larger than the left. The cases with occipital flatness in the contralateral side of the larger lateral ventricle were found more than the cases with occipital flatness in the ipsilateral side of the larger ventricle, that is to say, the direction of supine head position preference during early infant was suspected to be the more severely disturbed side of body. These results suggest that the supine head position preference to the right in newborn babies and infants with scoliosis or cerebral palsy might be the result of transient or permanent asymmetric (left > right) brain dysfunction.

  18. A supine cranio-spinal irradiation technique using moving field junctions

    Science.gov (United States)

    Mani, Karthick Raj; Sapru, Shantanu; Maria Das, K. J.; Basu, Ayan

    2016-12-01

    Aim: To demonstrate a simple technique of cranio-spinal irradiation (CSI) in supine position using inter fraction moving field junctions to feather out any potential hot and cold spots. Materials and Methods: Fifteen patients diagnosed with medulloblastoma were treated during the period February 2011 to June 2015 were included in this study. Out of fifteen patients in the study nine were male and 6 were female with a median age of 13.4 years (range 5-27 years). All the patients were positioned supine on CT simulation, immobilized using thermoplastic mask and aligned using room based laser system. Two parallel opposed lateral fields for the whole brain using an asymmetrical jaw with isocenter at C2 vertebral body. A posterior field also placed to cover the cervical and dorsal field using the same isocenter at C2. The second isocenter was placed at lumbar vertebral region to cover the remaining dorsal, lumbar and sacral region using an inter-fraction moving junction. Field-in-field and enhanced dynamic wedge used to homogeneous dose distribution when required. Results and Discussion: In this study, we found that only two patients failed in the primary site, no radiation myelitis or recurrences in the filed junctions were reported in these fifteen patients with a median follow-up of 36.4 months. The automated sequence of treatment plans with moving junctions in the comfortable supine position negating the need for manual junction matching or junction shifts avoiding potential treatment errors and also facilitating delivery of anesthesia where necessary.

  19. Primary and revision anterior supine total hip arthroplasty: an analysis of complications and reoperations.

    Science.gov (United States)

    Berend, Keith R; Kavolus, Joseph J; Morris, Michael J; Lombardi, Adolph V

    2013-01-01

    Anterior total hip arthroplasty (THA) has been touted by some as a muscle-sparing, less invasive procedure. Reports have focused on the high intraoperative and postoperative complication rates, the increased transfusion risk, and its questionable clinical benefits. The senior author's experience regarding complications and reoperations that occurred after primary and revision THA using an anterior supine intermuscular approach has been generally favorable. An electronic database was used to identify 906 patients treated with 1,035 consecutive anterior supine intermuscular THAs performed by a single surgeon between January 2007 and December 2010, which included 986 primary THAs, 2 resurfacings, 2 conversions of failed open reduction and internal fixation for fracture, and 45 revision THAs. The surgical technique used an anterior approach with a modified Smith-Petersen interval and was performed with the patient supine on a standard operating table without traction. The transfusion rate was 5%. There were three intraoperative calcar cracks and one canal perforation, which was treated with cerclage cables. Four wound complications required débridement, four hips had substantial lateral femoral cutaneous nerve paresthesias that had not resolved by the 12-month follow-up, and one femoral nerve palsy was reported. At up to 40 month's follow-up, there have been 25 revisions (2.4%), including 9 periprosthetic femoral fractures; 1 stem subsidence; 4 hips with aseptic loosening; 5 metal-on-metal bearing complications; 1 cup malpositioning, which was corrected the same day; 4 dislocations; and 1 infection. This 4-year experience with primary and revision anterior THAs has showed acceptable rates of perioperative transfusion, complications, and revisions.

  20. When prone position is contraindicated or not preferable, can supine percutaneous nephrolithotomy solve the problem?

    Directory of Open Access Journals (Sweden)

    A. Youssef

    2012-02-01

    Full Text Available PURPOSE: To assess safety and efficacy of supine percutaneous nephrolithotomy in patients for whom prone position or general anesthesia is contraindicated or not preferable due to associated comorbidities, overweight or ipsilateral upper ureteric calculi. MATERIALS AND METHODS: Fifty two patients (37 males and 15 females, mean age 33 ± 10.2 years were included in this study. Supine position was selected due to anesthetic considerations (preexisting compromised cardiopulmonary status, morbid obesity (body mass index > 40 kg/m² and/or other associated medical comorbidities, impossible prone position due to bone deformities or associated ipsilateral upper ureteric stone. Regional anesthesia was used in 24 patients while 28 patients underwent general anesthesia. After standard cystoscopy and retrograde ureteropyelography in the dorsal lithotomy position, the position was modified using 3 liters of saline bag below the ipsilateral upper flank. Percutaneous access to the pelvicalyceal system was performed through the posterior axillary line under fluoroscopic guidance. RESULTS: Successful renal puncture was achieved in all cases. Single access via the lower calyx was the most commonly used access (36 cases. Stone-free rate was 92.3%. Postoperative complications classified according to Clavien Dindo classification included bleeding requiring transfusion (3.8%, urinary leakage requiring ureteric stenting (5.8%, prolonged fever (7.7%, deep venous thrombosis (1.9% [grade III in all] and urinary leakage requiring ureteric stenting (5.8% [grade IIIa]. CONCLUSIONS: The modified supine position for percutaneous nephrolithotomy is a safe and effective option that offers several advantages with an excellent outcome. It can be performed safely for morbidly obese patients and those with cardiopulmonary compromise.

  1. MR imaging of herniated lumbar disc : morphologic change between supine and flexed-prone position

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Jin Yong; Lee, Seung Ro; Moon, Won Jin; Park, Dong Woo; Hahm, Chang Kok [Hanyang Univ., Seoul (Korea, Republic of); Kim, Sung Tae [Sungnam Inha Hospital, Sungnam (Korea, Republic of)

    1997-12-01

    The purpose of this study is to determine morphologic change in a herniated lumbar disc, as seen on MR imaging according to position change (supine and flexed-prone positions). A hundred and twenty-two patients with herniated lumbar discs, as seen on supine MR imaging, underwent repeat MR imaging in the flexed-prone position; 100 patients, who showed more than 2 deg of flexion angle difference, were included in this study. Sixty-two were men and thirty-eight were women, and their ages ranged from 13 to 59 (mean, 30) years. Disc degeneration was graded as 1,2 or 3, depending on the area of decreased signal intensity seen on a T2-weighted MR image. Difference in the angle of flexion is defined as the angle difference of lumbar curvature, calculated by the Begg-falconer method in supine and flexed-prone positions. Morphologic changes in herniated discs in difference positions were analysed on the basis of shape change of anterior epidural spaces, thecal sacs and posterior margins of herniated discs, and classified as either A (not changed) or B (changed). Group B was subtyped as type I (decreased herniation without change of shape), type II (decreased herniation with change of shape) or type III (increased disc herniation). We statistically analysed correlations between a patient`s age, morphologic change in a herniated disc in different positions, and degree of degeneration in such a disc, as well as the correlation between morphologic change in a herniated disc in different positions and the degree of the flexion angle. In the flexed-prone position, which is similar to that used during surgery, MRI can reveal various morphologic changes in a herniated lumbar disc, mainly decreased herniation, and is helpful in making decisions related to surgery. (author). 12 refs., 2 tabs., 4 figs.

  2. Image to physical space registration of supine breast MRI for image guided breast surgery

    Science.gov (United States)

    Conley, Rebekah H.; Meszoely, Ingrid M.; Pheiffer, Thomas S.; Weis, Jared A.; Yankeelov, Thomas E.; Miga, Michael I.

    2014-03-01

    Breast conservation therapy (BCT) is a desirable option for many women diagnosed with early stage breast cancer and involves a lumpectomy followed by radiotherapy. However, approximately 50% of eligible women will elect for mastectomy over BCT despite equal survival benefit (provided margins of excised tissue are cancer free) due to uncertainty in outcome with regards to complete excision of cancerous cells, risk of local recurrence, and cosmesis. Determining surgical margins intraoperatively is difficult and achieving negative margins is not as robust as it needs to be, resulting in high re-operation rates and often mastectomy. Magnetic resonance images (MRI) can provide detailed information about tumor margin extents, however diagnostic images are acquired in a fundamentally different patient presentation than that used in surgery. Therefore, the high quality diagnostic MRIs taken in the prone position with pendant breast are not optimal for use in surgical planning/guidance due to the drastic shape change between preoperative images and the common supine surgical position. This work proposes to investigate the value of supine MRI in an effort to localize tumors intraoperatively using image-guidance. Mock intraoperative setups (realistic patient positioning in non-sterile environment) and preoperative imaging data were collected from a patient scheduled for a lumpectomy. The mock intraoperative data included a tracked laser range scan of the patient's breast surface, tracked center points of MR visible fiducials on the patient's breast, and tracked B-mode ultrasound and strain images. The preoperative data included a supine MRI with visible fiducial markers. Fiducial markers localized in the MRI were rigidly registered to their mock intraoperative counterparts using an optically tracked stylus. The root mean square (RMS) fiducial registration error using the tracked markers was 3.4mm. Following registration, the average closest point distance between the MR

  3. Oblique rifting at Tempe Fossae, Mars

    Science.gov (United States)

    Fernández, Carlos; Anguita, Francisco

    2007-09-01

    This work shows the results of a structural study of the faults observed at the Tempe Rift (northeastern Tharsis region), Mars. A new, detailed map of faults and fault systems was used to geometrically characterize the fracture architecture of the Tempe Rift and to measure fault length, displacement, and spacing data, to analyze the spatial distribution of fault centroids, and to investigate the fractal nature of fault trace maps. A comparison with analog models and the use of conventional techniques of fault population analysis show that the Tempe Rift was most probably generated under sinistral oblique-rifting processes, which highlights the importance of the presence of inherited fractures in the tectonic evolution of the Noachian crust. The angle between the extension direction and the rift axis varies along the Tempe Rift, ranging from 50°-60° at its central southern part to 66°-88° to the southwest. Fault scaling relationships are similar to those found at mid-ocean ridges on Earth with exponential fault length-frequency distributions. Localized, inhomogeneous deformation generated weakly interacting faults, spanning the entire thickness of the mechanical layer. This thickness decreased from southwest to northeast along the rift, along with distance from the central part of the Tharsis dome.

  4. Camere aeree oblique: sistemi, applicazioni e prospettive future

    Directory of Open Access Journals (Sweden)

    Fabio Remondino

    2014-10-01

    Full Text Available The use of oblique imagery has become a standard for many civil and mapping applications, thanks to the development of airborne digital multi-camera systems, as proposed by many companies. The indisputable virtue of oblique photography lies in its simplicity of interpretation and understanding for inexperienced users allowing their use of oblique images in very different applications, such as building detection and reconstruction, building structural damage classification, road land updating and administration services, etc. We report an overview of the actual oblique commercial systems and the workflow for the automated orientation and dense matching of large image blocks. Perspectives, potentialities, pitfalls and suggestions for achieving satisfactory results are given too.

  5. Characteristics of Dust Plasma Sheath in an Oblique Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    ZOU Xiu

    2006-01-01

    @@ The characteristics of dust plasma sheath in an oblique magnetic field are investigated with a fluid model. Hot electrons, cold ions, neutral particles, and dust grains are taken into account in this system.

  6. Chemonucleolysis technique. New oblique approach requires no measurements.

    Science.gov (United States)

    Romy, M

    1986-01-01

    The author describes a new technique for intradiscal therapy that eliminates the need for measurements. The new technique for entering the lumbar disk for discolysis from the oblique approach is described as simple, accurate and safe.

  7. Effectiveness of oblique section display in thallium-201 myocardial tomography

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, A.R.; Gemmell, H.G.

    1986-08-01

    A simple left ventricle phantom, placed in a water-filled body phantom, has been used to compare the detectability of simulated perfusion defects in short-axis oblique sections with transverse section tomography and conventional planar imaging. Images of the phantom were assessed by five experienced observers and their responses analysed on a lesion-by-lesion basis. No significant difference in defect detectability was found between planar imaging and transverse section tomography. However, following reorientation of the transverse section data into oblique planes perpendicular to the long-axis of the phantom there was a statistically significant increase in defect detectability compared with planar imaging. Observers also detected significantly more defects using oblique section display compared with the original transverse sections. This suggests that reformatting of the transverse sections into oblique planes may be essential to realize the full potential of thallium-201 myocardial tomography.

  8. Comparison of Magnetic Resonance Imaging and Computed Tomography for Breast Target Volume Delineation in Prone and Supine Positions.

    Science.gov (United States)

    Pogson, Elise M; Delaney, Geoff P; Ahern, Verity; Boxer, Miriam M; Chan, Christine; David, Steven; Dimigen, Marion; Harvey, Jennifer A; Koh, Eng-Siew; Lim, Karen; Papadatos, George; Yap, Mei Ling; Batumalai, Vikneswary; Lazarus, Elizabeth; Dundas, Kylie; Shafiq, Jesmin; Liney, Gary; Moran, Catherine; Metcalfe, Peter; Holloway, Lois

    2016-11-15

    To determine whether T2-weighted MRI improves seroma cavity (SC) and whole breast (WB) interobserver conformity for radiation therapy purposes, compared with the gold standard of CT, both in the prone and supine positions. Eleven observers (2 radiologists and 9 radiation oncologists) delineated SC and WB clinical target volumes (CTVs) on T2-weighted MRI and CT supine and prone scans (4 scans per patient) for 33 patient datasets. Individual observer's volumes were compared using the Dice similarity coefficient, volume overlap index, center of mass shift, and Hausdorff distances. An average cavity visualization score was also determined. Imaging modality did not affect interobserver variation for WB CTVs. Prone WB CTVs were larger in volume and more conformal than supine CTVs (on both MRI and CT). Seroma cavity volumes were larger on CT than on MRI. Seroma cavity volumes proved to be comparable in interobserver conformity in both modalities (volume overlap index of 0.57 (95% Confidence Interval (CI) 0.54-0.60) for CT supine and 0.52 (95% CI 0.48-0.56) for MRI supine, 0.56 (95% CI 0.53-0.59) for CT prone and 0.55 (95% CI 0.51-0.59) for MRI prone); however, after registering modalities together the intermodality variation (Dice similarity coefficient of 0.41 (95% CI 0.36-0.46) for supine and 0.38 (0.34-0.42) for prone) was larger than the interobserver variability for SC, despite the location typically remaining constant. Magnetic resonance imaging interobserver variation was comparable to CT for the WB CTV and SC delineation, in both prone and supine positions. Although the cavity visualization score and interobserver concordance was not significantly higher for MRI than for CT, the SCs were smaller on MRI, potentially owing to clearer SC definition, especially on T2-weighted MR images. Copyright © 2016. Published by Elsevier Inc.

  9. Plasma volume and electrolyte shifts with heavy exercise in sitting and supine positions

    Science.gov (United States)

    Greenleaf, J. E.; Van Beaumont, W.; Brock, P. J.; Morse, J. T.; Mangseth, G. R.

    1979-01-01

    An experimental study was carried out to compare fluid and electrolyte shifts after heavy exercise performed by four voluntary male subjects (26-45 yr) in sitting and supine positions. Plasma volume and electrolyte shifts were measured during the 6-min control period and for 60 min after a continuous peak oxygen uptake test. The results indicate that the most likely driving force for the restitution of plasma volume after peak exercise is provided by a change in hydrostatic and/or systemic blood pressures when exercise ceases.

  10. Expanding Surgical Opportunities: Endoscopic Harvesting of the Vena Saphena Parva in Supine Position.

    Science.gov (United States)

    Rustenbach, Christian Jörg; Wachter, Kristina; Franke, Ulrich Friedrich Wilhelm; Baumbach, Hardy

    2016-08-05

    The small saphenous vein (SSV) has proved to be a valid graft option for coronary artery bypass grafting (CABG), if other grafts are absent or unsuitable. Beside the described open technique we herein present our approach to endoscopic harvesting in supine position in seven patients. Harvesting was successful in six patients. Mean skin-to-skin time was 29.8 minutes. There were no infections or neurological deficits and the intraoperatively measured graft flow was excellent according to mean flow and low pulsatility index. Therefore, endoscopic harvesting of the SSV extends surgical opportunities not only in CABG, but also in surgery of peripheral artery disease.

  11. Effects of extreme obliquity variations on the habitability of exoplanets.

    Science.gov (United States)

    Armstrong, J C; Barnes, R; Domagal-Goldman, S; Breiner, J; Quinn, T R; Meadows, V S

    2014-04-01

    We explore the impact of obliquity variations on planetary habitability in hypothetical systems with high mutual inclination. We show that large-amplitude, high-frequency obliquity oscillations on Earth-like exoplanets can suppress the ice-albedo feedback, increasing the outer edge of the habitable zone. We restricted our exploration to hypothetical systems consisting of a solar-mass star, an Earth-mass planet at 1 AU, and 1 or 2 larger planets. We verified that these systems are stable for 10(8) years with N-body simulations and calculated the obliquity variations induced by the orbital evolution of the Earth-mass planet and a torque from the host star. We ran a simplified energy balance model on the terrestrial planet to assess surface temperature and ice coverage on the planet's surface, and we calculated differences in the outer edge of the habitable zone for planets with rapid obliquity variations. For each hypothetical system, we calculated the outer edge of habitability for two conditions: (1) the full evolution of the planetary spin and orbit and (2) the eccentricity and obliquity fixed at their average values. We recovered previous results that higher values of fixed obliquity and eccentricity expand the habitable zone, but we also found that obliquity oscillations further expand habitable orbits in all cases. Terrestrial planets near the outer edge of the habitable zone may be more likely to support life in systems that induce rapid obliquity oscillations as opposed to fixed-spin planets. Such planets may be the easiest to directly characterize with space-borne telescopes.

  12. Effects of Extreme Obliquity Variations on the Habitability of Exoplanets

    Science.gov (United States)

    Armstrong, J. C.; Barnes, R.; Domagal-Goldman, S.; Breiner, J.; Quinn, T. R.; Meadows, V. S.

    2014-01-01

    We explore the impact of obliquity variations on planetary habitability in hypothetical systems with high mutual inclination. We show that large-amplitude, high-frequency obliquity oscillations on Earth-like exoplanets can suppress the ice-albedo feedback, increasing the outer edge of the habitable zone. We restricted our exploration to hypothetical systems consisting of a solar-mass star, an Earth-mass planet at 1 AU, and 1 or 2 larger planets. We verified that these systems are stable for 108 years with N-body simulations and calculated the obliquity variations induced by the orbital evolution of the Earth-mass planet and a torque from the host star. We ran a simplified energy balance model on the terrestrial planet to assess surface temperature and ice coverage on the planet's surface, and we calculated differences in the outer edge of the habitable zone for planets with rapid obliquity variations. For each hypothetical system, we calculated the outer edge of habitability for two conditions: (1) the full evolution of the planetary spin and orbit and (2) the eccentricity and obliquity fixed at their average values. We recovered previous results that higher values of fixed obliquity and eccentricity expand the habitable zone, but we also found that obliquity oscillations further expand habitable orbits in all cases. Terrestrial planets near the outer edge of the habitable zone may be more likely to support life in systems that induce rapid obliquity oscillations as opposed to fixed-spin planets. Such planets may be the easiest to directly characterize with space-borne telescopes.

  13. Form Birefringence in Thin Films with Oblique Columnar Structures

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-Guo; SHAO Jian-Da; WANG Su-Mei; HE Hong-Bo; FAN Zheng-Xiu

    2005-01-01

    @@ Effective medium theory is useful for designing optical elements with form birefringent subwavelength structures. Thinfilms fabricated by oblique deposition are similar to the two-dimensional surface relief subwavelength gratings. We use the effective medium theory to calculate the anisotropic optical properties of the thin films with oblique columnar structures. The effective refractive indices and the directions are calculated from effective medium theory. It is shown that optical thin films with predetermined refractive indices and birefringence may be engineered.

  14. Large capacity oblique all-wing transport aircraft

    Science.gov (United States)

    Galloway, Thomas L.; Phillips, James A.; Kennelly, Robert A., Jr.; Waters, Mark H.

    1996-01-01

    Dr. R. T. Jones first developed the theory for oblique wing aircraft in 1952, and in subsequent years numerous analytical and experimental projects conducted at NASA Ames and elsewhere have established that the Jones' oblique wing theory is correct. Until the late 1980's all proposed oblique wing configurations were wing/body aircraft with the wing mounted on a pivot. With the emerging requirement for commercial transports with very large payloads, 450-800 passengers, Jones proposed a supersonic oblique flying wing in 1988. For such an aircraft all payload, fuel, and systems are carried within the wing, and the wing is designed with a variable sweep to maintain a fixed subsonic normal Mach number. Engines and vertical tails are mounted on pivots supported from the primary structure of the wing. The oblique flying wing transport has come to be known as the Oblique All-Wing (OAW) transport. This presentation gives the highlights of the OAW project that was to study the total concept of the OAW as a commercial transport.

  15. Three-dimensional frictional plastic strain partitioning during oblique rifting

    Science.gov (United States)

    Duclaux, Guillaume; Huismans, Ritske S.; May, Dave

    2017-04-01

    Throughout the Wilson cycle the obliquity between lithospheric plate motion direction and nascent or existing plate boundaries prompts the development of intricate three-dimensional tectonic systems. Where oblique divergence dominates, as in the vast majority of continental rift and incipient oceanic domains, deformation is typically transtensional and large stretching in the brittle upper crust is primarily achieved by the accumulation of displacement on fault networks of various complexity. In continental rift depressions such faults are initially distributed over tens to hundreds of kilometer-wide regions, which can ultimately stretch and evolve into passive margins. Here, we use high-resolution 3D thermo-mechanical finite element models to investigate the relative timing and distribution of localised frictional plastic deformation in the upper crust during oblique rift development in a simplified layered lithosphere. We vary the orientation of a wide oblique heterogeneous weak zone (representing a pre-existing geologic feature like a past orogenic domain), and test the sensitivity of the shear zones orientation to a range of noise distribution. These models allow us to assess the importance of material heterogeneities for controlling the spatio-temporal shear zones distribution in the upper crust during oblique rifting, and to discuss the underlying controls governing oblique continental breakup.

  16. Pollical oblique ligament in humans and non-human primates.

    Science.gov (United States)

    Shrewsbury, Marvin

    2003-04-01

    A morphological study of the oblique ligament in the thumb is presented. The ligament was consistently described in human specimens and compared with dissections of non-human primates from different species. The oblique ligament was found in some, but not all, specimens in each of the following species examined: chimpanzee, orangutan, gibbon, anubis baboon, hamadryas baboon, squirrel monkey, lemur and marmoset. A revised identity of the oblique ligament is proposed as a reinforced distal border of a fibro-osseous annular pollical flexor sheath and whose function is not independent of the flexor sheath. The constant presence and tendinous trait of the pollical oblique ligament in humans, when compared with non-human primates, supports the notion that the oblique ligament strengthens the pollical flexor sheath in humans for restraint of the flexor pollicis longus tendon during forceful precision pinching. A derivation of the pollical oblique ligament is considered as representing a vestigial radial limb of a flexor pollicis superficialis tendon in the thumb.

  17. Evaluation of the integrity of the deltoid ligament in supination external rotation ankle fractures: a systematic review of the literature.

    Science.gov (United States)

    van den Bekerom, Michel P J; Mutsaerts, Eduard L A R; van Dijk, C Niek

    2009-02-01

    Review the literature concerning modalities to evaluate the integrity of the deltoid ligament in patients with supination external rotation ankle fractures. The electronic databases Pubmed/Medline, CINAHL and Embase were searched from 1987 to November 2007 to identify all published original studies concerning diagnostic modalities to evaluate the integrity of the deltoid ligament in adult ankle fractures. This review included nine studies involving 423 ankle fractures. Three trails investigated medial tenderness; two studies, ecchymosis; two studies, swelling; one study, an injury radiograph; six studies, a type of radiographic stress view; one study, the Lauge-Hansen classification; one study, MRI; and one article studied arthroscopy in the evaluation of the deltoid ligament integrity. Swelling, ecchymosis, medial tenderness, initial injury radiographs and the Lauge-Hansen classification are less adequate predictors of the integrity of the deltoid ligament. Manual or the less painful variant, the gravity external rotation stress radiographs are considered the gold standard. The amount of medial clear space widening indicative of a positive external rotation stress test has been somewhat variable in the literature but > or =5 mm is generally regarded as most reliable. Achieving adequate external rotation of the foot when obtaining stress radiographs is more important than positioning the ankle in the appropriate degree of ankle flexion. The amount of applied force necessary when performing an external rotation stress radiograph is not well defined and mainly determined by the patient's pain level. The indication for surgery should not be based on the absolute value of one parameter but on the combination of several parameters. If nonoperative treatment is chosen despite a positive stress radiograph, close follow-up is critical because subluxation of the ankle joint is still possible. MRI could be useful in individual cases.

  18. The "anatomic" view of the suprarenals in medical imaging.

    Science.gov (United States)

    Sénécail, B; Colin, D; Person, H; Vallée, B; Lefèvre, C

    1994-01-01

    Based on coordinates derived from three series of anatomic sections, the authors propose a view for tomographic investigation, applicable in MRI and ultrasound, which reconstructs the ideal image of the suprarenal gland in its quadrilateral as described by Testut. This "anatomic" view is 45 degrees vertical and oblique, intermediate between the sagittal and frontal views, which it can advantageously replace. A new aspect of suprarenal tomography, recalling the image of a triskele, is described in the context of this view.

  19. View angle dependence of cloud optical thicknesses retrieved by MODIS

    Science.gov (United States)

    Marshak, Alexander; Varnai, Tamas

    2005-01-01

    This study examines whether cloud inhomogeneity influences the view angle dependence of MODIS cloud optical thickness (tau) retrieval results. The degree of cloud inhomogeneity is characterized through the local gradient in 11 microns brightness temperature. The analysis of liquid phase clouds in a one year long global dataset of Collection 4 MODIS data reveals that while optical thickness retrievals give remarkably consistent results for all view directions if clouds are homogeneous, they give much higher tau-values for oblique views than for overhead views if clouds are inhomogeneous and the sun is fairly oblique. For solar zenith angles larger than 55deg, the mean optical thickness retrieved for the most inhomogeneous third of cloudy pixels is more than 30% higher for oblique views than for overhead views. After considering a variety of possible scenarios, the paper concludes that the most likely reason for the increase lies in three-dimensional radiative interactions that are not considered in current, one-dimensional retrieval algorithms. Namely, the radiative effect of cloud sides viewed at oblique angles seems to contribute most to the enhanced tau-values. The results presented here will help understand cloud retrieval uncertainties related to cloud inhomogeneity. They complement the uncertainty estimates that will start accompanying MODIS cloud products in Collection 5 and may eventually help correct for the observed view angle dependent biases.

  20. Aerial Photography and Imagery, Oblique, Pictometry Oblique Imagery for the 10-County Atlanta Regional Commission Region, Published in 2007, Atlanta Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Oblique dataset, was produced all or in part from Other information as of 2007. It is described as 'Pictometry Oblique Imagery...

  1. Having views, abandoning views

    DEFF Research Database (Denmark)

    Sobisch, Jan-Ulrich

    2013-01-01

    In the bKa' brgyud tradition of Tibetan Buddhism, holding a philosophical view cannot produce an understanding of ultimate reality. The article contains some arguments why views must ultimately be abandoned....

  2. The influence of supine posture on chest wall volume changes is higher in obese than in normal weight children.

    Science.gov (United States)

    Silva, Letícia; Barcelar, Jacqueline de Melo; Rattes, Catarina Souza; Sayão, Larissa Bouwman; Reinaux, Cyda Albuquerque; Campos, Shirley L; Brandão, Daniella Cunha; Fregonezi, Guilherme; Aliverti, Andrea; Dornelas de Andrade, Armèle

    2015-02-01

    The objective of this study was to analyze thoraco-abdominal kinematics in obese children in seated and supine positions during spontaneous quiet breathing. An observational study of pulmonary function and chest wall volume assessed by optoelectronic plethysmography was conducted on 35 children aged 8-12 years that were divided into 2 groups according to weight/height ratio percentiles: there were 18 obese children with percentiles greater than 95 and 17 normal weight children with percentiles of 5-85. Pulmonary function (forced expiratory volume in 1 s (FEV1); forced vital capacity (FVC); and FEV1/FVC ratio), ventilatory pattern, total and compartment chest wall volume variations, and thoraco-abdominal asynchronies were evaluated. Tidal volume was greater in seated position. Pulmonary and abdominal rib cage tidal volume and their percentage contribution to tidal volume were smaller in supine position in both obese and control children, while abdominal tidal volume and its percentage contribution was greater in the supine position only in obese children and not in controls. No statistically significant differences were found between obese and control children and between supine and seated positions regarding thoraco-abdominal asynchronies. We conclude that in obese children thoraco-abdominal kinematics is influenced by supine posture, with an increase of the abdominal and a decreased rib cage contribution to ventilation, suggesting that in this posture areas of hypoventilation can occur in the lung.

  3. The supine-to-prone position change induces modification of endotracheal tube cuff pressure accompanied by tube displacement.

    Science.gov (United States)

    Minonishi, Toshiyuki; Kinoshita, Hiroyuki; Hirayama, Michiko; Kawahito, Shinji; Azma, Toshiharu; Hatakeyama, Noboru; Fujiwara, Yoshihiro

    2013-02-01

    To determine whether the supine-to-prone position change displaced the endotracheal tube (ETT) and, if so, whether the displacement related to this change modified ETT cuff pressure. Prospective study. Operating room of a university hospital. 132 intubated, adult, ASA physical status 1, 2, and 3 patients undergoing lumbar spine surgery. After induction of anesthesia, each patient's trachea was intubated. The insertion depth of each ETT was 23 cm for men and 21 cm for women at the upper incisors. In the supine position and after the supine-to-prone position change with the head rotated to the right, the length from the carina to ETT tip and ETT cuff pressure were measured. After the supine-to-prone position change, 91.7% patients had ETT tube displacement. Of these, 48% of patients' ETT moved ≥ 10 mm, whereas 86.3% of patients had changes in tube cuff pressure. There was a slight but significant correlation between ETT movement and change in cuff pressure. Depending on the position change, ETT cuff pressure decreased and the ETT tended to withdraw. After the supine-to-prone position change, patients had ETT tube displacement. Such ETT movement may be accompanied by a decrease in cuff pressure. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

    Science.gov (United States)

    Dewez, T. J. B.

    2014-05-01

    Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

  5. Lumbar spine disc heights and curvature: upright posture vs. supine compression harness

    Science.gov (United States)

    Lee, Shi-Uk; Hargens, Alan R.; Fredericson, Michael; Lang, Philipp K.

    2003-01-01

    INTRODUCTION: Spinal lengthening in microgravity is thought to cause back pain in astronauts. A spinal compression harness can compress the spine to eliminate lengthening but the loading condition with harness is different than physiologic conditions. Our purpose was to compare the effect of spine compression with a harness in supine position on disk height and spinal curvature in the lumbar spine to that of upright position as measured using a vertically open magnetic resonance imaging system. METHODS: Fifteen healthy subjects volunteered. On day 1, each subject lay supine for an hour and a baseline scan of the lumbar spine was performed. After applying a load of fifty percent of body weight with the harness for thirty minutes, the lumbar spine was scanned again. On day 2, after a baseline scan, a follow up scan was performed after kneeling for thirty minutes within the gap between two vertically oriented magnetic coils. Anterior and posterior disk heights, posterior disk bulging, and spinal curvature were measured from the baseline and follow up scans. RESULTS: Anterior disk heights increased and posterior disk heights decreased compared with baseline scans both after spinal compression with harness and upright posture. The spinal curvature increased by both loading conditions of the spine. DISCUSSION: The spinal compression with specially designed harness has the same effect as the physiologic loading of the spine in the kneeling upright position. The harness shows some promise as a tool to increase the diagnostic capabilities of a conventional MR system.

  6. Impedance cardiography using band and regional electrodes in supine, sitting, and during exercise.

    Science.gov (United States)

    Patterson, R P; Wang, L; Raza, S B

    1991-05-01

    The electrical impedance and its first derivative (dZ/dt) were measured at 100 kHz on 10 normal males in supine, sitting, and during upright bicycle exercise in order to compare the contribution of regional electrodes to the standard band electrode signal and to evaluate the possible use of spot electrodes for stroke volume (SV) measurements. Simultaneous measurements were made from band electrodes placed around the neck and lower thorax and from spot electrodes which recorded signals from the neck, upper thorax, and lower thorax. The results showed that approximately equal parts of the dZ/dt waveform came from the neck and upper thorax with the lower thorax contribution small but providing important features of the band signal. Changing from supine to sitting showed percentage decreases of 35% and 46% for the band and neck signals, respectively, with an increase of 19% for the upper thorax signal. The percentage increases in SV with upright exercise were 34%, 52%, and 24% for the bands, neck, and upper thorax signals, respectively. Band signal is made up of different signals from various regions of the thorax. Its ability to predict correct changes in SV may result from some "lucky" coincidences. The use of regional electrodes will probably not give the same SV information but may be important in measuring regional activities of the central circulation.

  7. Reliability assessment of measuring active wrist pronation and supination range of motion with a smartphone.

    Science.gov (United States)

    Santos, C; Pauchard, N; Guilloteau, A

    2017-10-01

    This study aimed to improve clinical examination techniques by determining the reliability of different methods to evaluate forearm movements. Two methods using the iPhone™ 5 and its gyroscope application (alone [I5] or attached to a selfie stick [ISS]) were compared with two conventional measurement devices (a plastic goniometer with a hand-held pencil [HHP] and a bubble goniometer [BG]) to evaluate the active range of movement (AROM) of the wrist during pronation and supination. Two independent groups of subjects took part in this prospective single-center diagnostic study: 20 healthy subjects and 20 patients. The four evaluation methods had high intra-observer consistency after three measurements (intra-class correlation coefficient [ICC] [3, 1] of 0.916 for the HHP; 0.944 for ISS; 0.925 for BG; 0.933 for I5) and excellent inter-observer reliability (ICC [2, k] of 0.926 for HHP; 0.934 for ISS; 0.899 for BG; 0.894 for I5), with an agreement of plus or minus 2°. When these devices are used with rigorous methodology, they are reliable for the goniometric evaluation of AROM of wrist pronation and supination. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  8. Lumbar spine disc heights and curvature: upright posture vs. supine compression harness

    Science.gov (United States)

    Lee, Shi-Uk; Hargens, Alan R.; Fredericson, Michael; Lang, Philipp K.

    2003-01-01

    INTRODUCTION: Spinal lengthening in microgravity is thought to cause back pain in astronauts. A spinal compression harness can compress the spine to eliminate lengthening but the loading condition with harness is different than physiologic conditions. Our purpose was to compare the effect of spine compression with a harness in supine position on disk height and spinal curvature in the lumbar spine to that of upright position as measured using a vertically open magnetic resonance imaging system. METHODS: Fifteen healthy subjects volunteered. On day 1, each subject lay supine for an hour and a baseline scan of the lumbar spine was performed. After applying a load of fifty percent of body weight with the harness for thirty minutes, the lumbar spine was scanned again. On day 2, after a baseline scan, a follow up scan was performed after kneeling for thirty minutes within the gap between two vertically oriented magnetic coils. Anterior and posterior disk heights, posterior disk bulging, and spinal curvature were measured from the baseline and follow up scans. RESULTS: Anterior disk heights increased and posterior disk heights decreased compared with baseline scans both after spinal compression with harness and upright posture. The spinal curvature increased by both loading conditions of the spine. DISCUSSION: The spinal compression with specially designed harness has the same effect as the physiologic loading of the spine in the kneeling upright position. The harness shows some promise as a tool to increase the diagnostic capabilities of a conventional MR system.

  9. Having views, abandoning views

    DEFF Research Database (Denmark)

    Sobisch, Jan-Ulrich

    2013-01-01

    In the bKa' brgyud tradition of Tibetan Buddhism, holding a philosophical view cannot produce an understanding of ultimate reality. The article contains some arguments why views must ultimately be abandoned.......In the bKa' brgyud tradition of Tibetan Buddhism, holding a philosophical view cannot produce an understanding of ultimate reality. The article contains some arguments why views must ultimately be abandoned....

  10. SAR and Oblique Aerial Optical Image Fusion for Urban Area Image Segmentation

    Science.gov (United States)

    Fagir, J.; Schubert, A.; Frioud, M.; Henke, D.

    2017-05-01

    The fusion of synthetic aperture radar (SAR) and optical data is a dynamic research area, but image segmentation is rarely treated. While a few studies use low-resolution nadir-view optical images, we approached the segmentation of SAR and optical images acquired from the same airborne platform - leading to an oblique view with high resolution and thus increased complexity. To overcome the geometric differences, we generated a digital surface model (DSM) from adjacent optical images and used it to project both the DSM and SAR data into the optical camera frame, followed by segmentation with each channel. The fused segmentation algorithm was found to out-perform the single-channel version.

  11. Comparison of prone versus supine 18F-FDG-PET of locally advanced breast cancer: Phantom and preliminary clinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jason M.; Rani, Sudheer D.; Li, Xia; Whisenant, Jennifer G.; Abramson, Richard G. [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232 and Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37232 (United States); Arlinghaus, Lori R. [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232 (United States); Lee, Tzu-Cheng [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); MacDonald, Lawrence R.; Partridge, Savannah C. [Department of Radiology, University of Washington, Seattle, Washington 98195 (United States); Kang, Hakmook [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232 and Department of Biostatistics, Vanderbilt University, Nashville, Tennessee 37232 (United States); Linden, Hannah M. [Department of Medical Oncology, University of Washington, Seattle, Washington 98195 (United States); Kinahan, Paul E. [Department of Radiology, University of Washington, Seattle, Washington 98195 (United States); Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States); Yankeelov, Thomas E., E-mail: thomas.yankeelov@vanderbilt.edu [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Physics, Vanderbilt University, Nashville, Tennessee 37232 (United States); Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee 37232 (United States)

    2015-07-15

    Purpose: Previous studies have demonstrated how imaging of the breast with patients lying prone using a supportive positioning device markedly facilitates longitudinal and/or multimodal image registration. In this contribution, the authors’ primary objective was to determine if there are differences in the standardized uptake value (SUV) derived from [{sup 18}F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in breast tumors imaged in the standard supine position and in the prone position using a specialized positioning device. Methods: A custom positioning device was constructed to allow for breast scanning in the prone position. Rigid and nonrigid phantom studies evaluated differences in prone and supine PET. Clinical studies comprised 18F-FDG-PET of 34 patients with locally advanced breast cancer imaged in the prone position (with the custom support) followed by imaging in the supine position (without the support). Mean and maximum values (SUV{sub peak} and SUV{sub max}, respectively) were obtained from tumor regions-of-interest for both positions. Prone and supine SUV were linearly corrected to account for the differences in 18F-FDG uptake time. Correlation, Bland–Altman, and nonparametric analyses were performed on uptake time-corrected and uncorrected data. Results: SUV from the rigid PET breast phantom imaged in the prone position with the support device was 1.9% lower than without the support device. In the nonrigid PET breast phantom, prone SUV with the support device was 5.0% lower than supine SUV without the support device. In patients, the median (range) difference in uptake time between prone and supine scans was 16.4 min (13.4–30.9 min), which was significantly—but not completely—reduced by the linear correction method. SUV{sub peak} and SUV{sub max} from prone versus supine scans were highly correlated, with concordance correlation coefficients of 0.91 and 0.90, respectively. Prone SUV{sub peak} and SUV{sub max} were

  12. Effect of intermittent, supine cervical traction on the myoelectric activity of the upper trapezius muscle in subjects with neck pain.

    Science.gov (United States)

    Jette, D U; Falkel, J E; Trombly, C

    1985-08-01

    This study was undertaken to compare the myoelectric activity of the upper trapezius muscle before, during, and after intermittent, supine cervical traction. Twelve people with diagnosed disease or injury of the cervical spine served as subjects. Electromyographic recordings were taken from the upper trapezius muscle with bipolar surface electrodes. The subjects were treated with 20 minutes of intermittent, cervical traction at a force of 8% of their body weight. Recordings were taken with the subjects in the supine position before the traction, during one pull and release phase of the 10th and 20th minutes of traction, and after completion of the traction treatment. An analysis of variance with repeated measures showed no significant differences in the myoelectrical activity during the six time periods measured. The results of this study do not support the clinical use of intermittent, supine traction to produce cervical muscle relaxation.

  13. The effect of a Galeazzi fracture on the strength of pronation and supination two years after surgical treatment.

    Science.gov (United States)

    Ploegmakers, J J W; The, B; Brutty, M; Ackland, T R; Wang, A W

    2013-11-01

    The aim of this study was to determine the effect of a Galeazzi fracture on the strength of pronation and supination at a mean of two years after surgical treatment. The strength of pronation and supination was measured in varying rotational positions of the forearm of ten male patients (mean age 38.9 years (21 to 64)) who had undergone plate fixation for a Galeazzi fracture. The stability of the distal radioulnar joint was assessed, and a clinical assessment using the quick-Disabilities of the Arm Shoulder and Hand (quickDASH) questionnaire and patient-related wrist examination (PRWE) scores was undertaken. In addition, the strength of pronation and supination was measured in a male control group of 42 healthy volunteers (mean age 21.8 years (18 to 37)). The mean absolute loss of strength of supination in the injured compared with the non-injured arm throughout all ranges of forearm rotation was 16.1 kg (sem 5.3), corresponding to a relative loss of 12.5% (95% confidence interval (CI) 3.6 to 21.4). For the strength of pronation, the mean loss was 19.1 kg (sem 4.5), corresponding to a relative loss of 27.2% (95% CI 14.2 to 40.1). Loss of strength of supination following a Galeazzi fracture correlated with poor quickDASH (p = 0.03) and PRWE scores (p Galeazzi fracture is associated with worse clinical scores, highlighting the importance of supination of the forearm in function of the upper limb.

  14. Stable least-squares matching for oblique images using bound constrained optimization and a robust loss function

    Science.gov (United States)

    Hu, Han; Ding, Yulin; Zhu, Qing; Wu, Bo; Xie, Linfu; Chen, Min

    2016-08-01

    Least-squares matching is a standard procedure in photogrammetric applications for obtaining sub-pixel accuracies of image correspondences. However, least-squares matching has also been criticized for its instability, which is primarily reflected by the requests for the initial correspondence and favorable image quality. In image matching between oblique images, due to the blur, illumination differences and other effects, the image attributes of different views are notably different, which results in a more severe convergence problem. Aiming at improving the convergence rate and robustness of least-squares matching of oblique images, we incorporated prior geometric knowledge in the optimization process, which is reflected as the bounded constraints on the optimizing parameters that constrain the search for a solution to a reasonable region. Furthermore, to be resilient to outliers, we substituted the square loss with a robust loss function. To solve the composite problem, we reformulated the least-squares matching problem as a bound constrained optimization problem, which can be solved with bounds constrained Levenberg-Marquardt solver. Experimental results consisting of images from two different penta-view oblique camera systems confirmed that the proposed method shows guaranteed final convergences in various scenarios compared to the approximately 20-50% convergence rate of classical least-squares matching.

  15. Inferior oblique muscle paresis as a sign of myasthenia gravis.

    Science.gov (United States)

    Almog, Yehoshua; Ben-David, Merav; Nemet, Arie Y

    2016-03-01

    Myasthenia gravis may affect any of the six extra-ocular muscles, masquerading as any type of ocular motor pathology. The frequency of involvement of each muscle is not well established in the medical literature. This study was designed to determine whether a specific muscle or combination of muscles tends to be predominantly affected. This retrospective review included 30 patients with a clinical diagnosis of myasthenia gravis who had extra-ocular muscle involvement with diplopia at presentation. The diagnosis was confirmed by at least one of the following tests: Tensilon test, acetylcholine receptor antibodies, thymoma on chest CT scan, or suggestive electromyography. Frequency of involvement of each muscle in this cohort was inferior oblique 19 (63.3%), lateral rectus nine (30%), superior rectus four (13.3%), inferior rectus six (20%), medial rectus four (13.3%), and superior oblique three (10%). The inferior oblique was involved more often than any other muscle (pmyasthenia gravis can be difficult, because the disease may mimic every pupil-sparing pattern of ocular misalignment. In addition diplopia caused by paresis of the inferior oblique muscle is rarely encountered (other than as a part of oculomotor nerve palsy). Hence, when a patient presents with vertical diplopia resulting from an isolated inferior oblique palsy, myasthenic etiology should be highly suspected.

  16. Obliquity pacing of the late Pleistocene glacial terminations.

    Science.gov (United States)

    Huybers, Peter; Wunsch, Carl

    2005-03-24

    The 100,000-year timescale in the glacial/interglacial cycles of the late Pleistocene epoch (the past approximately 700,000 years) is commonly attributed to control by variations in the Earth's orbit. This hypothesis has inspired models that depend on the Earth's obliquity (approximately 40,000 yr; approximately 40 kyr), orbital eccentricity (approximately 100 kyr) and precessional (approximately 20 kyr) fluctuations, with the emphasis usually on eccentricity and precessional forcing. According to a contrasting hypothesis, the glacial cycles arise primarily because of random internal climate variability. Taking these two perspectives together, there are currently more than thirty different models of the seven late-Pleistocene glacial cycles. Here we present a statistical test of the orbital forcing hypothesis, focusing on the rapid deglaciation events known as terminations. According to our analysis, the null hypothesis that glacial terminations are independent of obliquity can be rejected at the 5% significance level, whereas the corresponding null hypotheses for eccentricity and precession cannot be rejected. The simplest inference consistent with the test results is that the ice sheets terminated every second or third obliquity cycle at times of high obliquity, similar to the original proposal by Milankovitch. We also present simple stochastic and deterministic models that describe the timing of the late-Pleistocene glacial terminations purely in terms of obliquity forcing.

  17. A Quick and Affine Invariance Matching Method for Oblique Images

    Directory of Open Access Journals (Sweden)

    XIAO Xiongwu

    2015-04-01

    Full Text Available This paper proposed a quick, affine invariance matching method for oblique images. It calculated the initial affine matrix by making full use of the two estimated camera axis orientation parameters of an oblique image, then recovered the oblique image to a rectified image by doing the inverse affine transform, and left over by the SIFT method. We used the nearest neighbor distance ratio(NNDR, normalized cross correlation(NCC measure constraints and consistency check to get the coarse matches, then used RANSAC method to calculate the fundamental matrix and the homography matrix. And we got the matches that they were interior points when calculating the homography matrix, then calculated the average value of the matches' principal direction differences. During the matching process, we got the initial matching features by the nearest neighbor(NN matching strategy, then used the epipolar constrains, homography constrains, NCC measure constrains and consistency check of the initial matches' principal direction differences with the calculated average value of the interior matches' principal direction differences to eliminate false matches. Experiments conducted on three pairs of typical oblique images demonstrate that our method takes about the same time as SIFT to match a pair of oblique images with a plenty of corresponding points distributed evenly and an extremely low mismatching rate.

  18. An image-guided technique for planning and verification of supine craniospinal irradiation.

    Science.gov (United States)

    McMahon, Ryan L; Larrier, Nicole A; Wu, Q Jackie

    2011-01-31

    We present a technique for planning and verification of craniospinal treatment with the patient in the supine position. Treatment delivery and verification is streamlined through the use of modern imaging techniques. Treatments use two lateral brain fields abutted to a single or pair of posterior spine fields. Treatment delivery is simplified by aligning all isocenters in the anterior-posterior and lateral directions. Patient positioning is accomplished via on-board kV imaging. Verification of field shape and junctions is accomplished with BB placement and MV portal imaging. Daily treatment is simplified by using only longitundinal couch shifts, which are recorded in the patient chart and RV database. The technique is simple to implement in a clinic that is already using a similar beam arrangement with the patient prone. It requires no additional devices to be fabricated (for immobilization or QA), and it takes advantage of all the existing elements of a modern linac.

  19. [A case of ventilation disorder and poor oxygenation after changing position from prone to supine].

    Science.gov (United States)

    Yamaguchi, Satoshi; Hirakawa, Kei; Kitamura, Jiro

    2013-01-01

    A 68-year-old obese woman (BMI 35) underwent posterior lumbar interbody fusion in prone position. Immediately after changing position postoperatively from prone to supine, severe ventilation disorder and poor oxygenation occured. Chest X-ray showed severe atelectasis. Poor oxygenation was suspected to be the result of the atelectasis by the pressure of massive abdominal fatty tissue to the diaphragm. Ventilation disorder was suspected of the bronchospasm associated with inadequate anesthesia. We ventilated her manually with a bag in Fowler position for twenty minutes, and then mechanically by pressure controlled ventilation. She recovered gradually. It is concluded that in obese patients undergoing operation in prone position, changing position should be done very carefully during adequate anesthesia, understanding respiratory physiology in positioning and considering the effect of the abdominal fatty tissue to the diaphragm.

  20. Orthostatic and Supine Blood Pressures Are Associated with White Matter Hyperintensities in Parkinson Disease

    Directory of Open Access Journals (Sweden)

    Yoon-Sang Oh

    2013-10-01

    Full Text Available Background and Purpose: Several reports on the elderly population have suggested that orthostatic hypotension is associated with white matter hyperintensities (WMH; however, little information is available on patients with Parkinson’s disease (PD. Methods: We analyzed the association blood pressure profiles during tilt table testing with WMH scores in 117 patients with PD. WMH were rated using the semiquantitative visual rating system proposed by Scheltens et al. Results: The presence of orthostatic hypotension was associated with increasing tendency of WMH score and the blood pressure changes during tilting and supine blood pressure were positively correlated with increasing WMH score. Conclusions: This finding indicates that hemodynamic changes associated with orthostatic hypotension may be associated with white matter changes in patients with PD.

  1. OBLIQUE PROJECTION REALIZATION OF A KERNEL-BASED NONLINEAR DISCRIMINATOR

    Institute of Scientific and Technical Information of China (English)

    Liu Benyong; Zhang Jing

    2006-01-01

    Previously, a novel classifier called Kernel-based Nonlinear Discriminator (KND) was proposed to discriminate a pattern class from other classes by minimizing mean effect of the latter. To consider the effect of the target class, this paper introduces an oblique projection algorithm to determine the coefficients of a KND so that it is extended to a new version called extended KND (eKND). In eKND construction, the desired output vector of the target class is obliquely projected onto the relevant subspace along the subspace related to other classes. In addition, a simple technique is proposed to calculate the associated oblique projection operator. Experimental results on handwritten digit recognition show that the algorithm performes better than a KND classifier and some other commonly used classifiers.

  2. Research On The Measure Method Of Oblique Pinhole Parameters

    Directory of Open Access Journals (Sweden)

    Ma Yu-Zhen

    2016-01-01

    Full Text Available There are many special advantages in measuring the diameter of blind and deep holes with a capacitive probe, there are still some challenges for the measurement of a oblique pinhole parameters because the measuring device is inconvenient to stretch into the oblique pinhole exactly. A five-dimensional measurement system was adopted in the paper which included a capacitive sensor probe and a three-coordinate measuring machine to accomplish the measurement for oblique pinholes. With the help of the three-dimensional coordinates measured from the pinhole axis, we put forward a comprehensive method of combining the projection method and the least squares method together for fitting spatial straight line to obtain the optimal equation of the spacial axis. Finally, a reliable and entire measurement system was set up.

  3. Chaotic obliquity and the nature of the Martian climate

    Science.gov (United States)

    Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

    1995-01-01

    Recent calculations of the Martian obliquity suggests that it varies chaotically on timescales longer than about 10(exp 7) years and varies between about 0 and 60 deg. We examine the seasonal water behavior at obliquities between 40 and 60 deg. Up to several tens of centimeters of water may sublime from the polar caps each year, and possibly move to the equator, where it is more stable. The CO2 frost and CO2-H2O clathrate hydrate are stable in thepolar deposits below a few tens of meters depth, so that the polar cap could contain a significant CO2 reservoir. If CO2 is present, it could be left over from the early history of Mars; also, it could be released into the atmosphere during periods of high obliquity, causing occasional periods of more-clement climate.

  4. Numerical modelling of steel tubes under oblique crushing forces

    Science.gov (United States)

    Ismail, A. E.; Rahman, M. Q. Abdul; Nezere, N.; Jamian, S.; Kamarudin, K. A.; Awang, M. K.; Nor, M. K. Mohd; Ibrahim, M. N.; Rasidi Ibrahim, M.; Zulafif Rahim, M.; Fahrul Hassan, Mohd; Nor, Nik Hisyamudin Muhd; Arifin, A. M. T.; Zaini Yunos, Muhamad

    2017-08-01

    This paper presents the numerical assessment of crushing responses of elliptical tubes under crushing forces. Based on the literature survey, tremendous amount of works on the axial crushing behaviour can be found. However, the studies on the oblique crushing responses are rarely found. Therefore, this work investigates numerically the elliptical tubes under compressions. The numerical model of the tubes are developed using ANSYS finite element program. Two important parameters are used such as elliptical ratios and oblique angles. The tubes are compressed quasi-statically and the force-displacement curves are extracted. Then, the area under the curves are calculated and it is represented the performances of energy absorptions. It is found numerically that the introductions of oblique angles during the crushing processes decrease the crushing performances. However, the elliptical-shaped tubes capable to enhance the energy absorption capabilities. On the other hand, the elliptical-shaped tubes produced the enhancement on the energy absorption capabilities.

  5. Oblique aerial images and their use in cultural heritage documentation

    DEFF Research Database (Denmark)

    Höhle, Joachim

    2013-01-01

    Oblique images enable three-dimensional (3d) modelling of objects with vertical dimensions. Such imagery is nowadays systematically taken of cities and may easily become available. The documentation of cultural heritage can take advantage of these sources of information. Two new oblique camera...... systems are presented and characteristics of such images are summarized. A first example uses images of a new multi-camera system for the derivation of orthoimages, façade plots with photo texture, 3d scatter plots, and dynamic 3d models of a historic church. The applied methodology is based...... developments. Special attention is given to the quality of input images. Investigations are carried out on edges in the images. The combination of oblique and nadir images enables new possibilities in the processing. The use of the near-infrared channel besides the red, green, and blue channel of the applied...

  6. Oblique perforation of thick metallic plates by rigid projectiles

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Chen; Qingming Li; Saucheong Fan

    2006-01-01

    Oblique perforation of thick metallic plates by rigid Drojectiles with various nose shapes is studied in this paper.Two perforation mechanisms,i.e., the hole enlargement for a sharp projectile nose and the plugging formation for a blunt projectile nose,are considered in the proposed analytical model.It is shown that the perforation of a thick plate is dominated by several non-dimensional numbers,i.e., the impact function,the geometry function of projectile,the non-dimensional thickness of target and the impact obliquity.Explicit formulae are obtained to predict the ballistic limit.residual velocity and directional change for the oblique perforation of thick metallic plates.The proposed model is able to predict the critical condition for the occurrence of ricochet.The proposed model is validated by comparing the predictions with other existing models and independent experimental data.

  7. Method of Calculation of Crown Wall Stability in Oblique Waves

    DEFF Research Database (Denmark)

    Burcharth, Hans F.

    2007-01-01

    The wave loading along a structure exposed to oblique waves varies in time and space. Despite of this, the wave generated pressures are usually recorded by gauges only in one position of the wall (more gauges densily spaced is regarded as one position).......The wave loading along a structure exposed to oblique waves varies in time and space. Despite of this, the wave generated pressures are usually recorded by gauges only in one position of the wall (more gauges densily spaced is regarded as one position)....

  8. Experimental studies of oblique impact. [of meteorites on planetary surfaces

    Science.gov (United States)

    Gault, D. E.; Wedekind, J. A.

    1978-01-01

    Meteoritic materials most probably impact planetary bodies along oblique trajectories inclined less than 45 deg above their surfaces. Laboratory studies of hypervelocity impacts against rock and particulate media are presented that indicate important effects of obliquity on crater size, shape, and ejecta distribution. The effects are particularly important to crater size-frequency analyses and geologic interpretations of crater formations. Impacts at shallow incidence, which are not uncommon, lead to ricochet of the impacting object accompanied with some entrained excavated materials at velocities only slightly reduced from the pre-impact value.

  9. Evaluation of the integrity of the deltoid ligament in supination external rotation ankle fractures: a systematic review of the literature

    NARCIS (Netherlands)

    van den Bekerom, M.P.J.; Mutsaerts, E.L.A.R.; van Dijk, C.N.

    2009-01-01

    BACKGROUND AND PURPOSE: Review the literature concerning modalities to evaluate the integrity of the deltoid ligament in patients with supination external rotation ankle fractures. METHODS: The electronic databases Pubmed/Medline, CINAHL and Embase were searched from 1987 to November 2007 to

  10. Effect of Lumbar Disc Degeneration and Low-Back Pain on the Lumbar Lordosis in Supine and Standing

    DEFF Research Database (Denmark)

    Hansen, Bjarke B; Bendix, Tom; Grindsted, Jacob

    2015-01-01

    of position from supine to standing and is known as an essential contributor to dynamic changes. However, the lordosis may be affected by disc degeneration and pain. METHODS: Patients with LBP >40 on a 0 to 100 mm Visual Analog Scale (VAS) both during activity and rest and a sex and age-decade matching...

  11. Risk of inferior vena cava compression syndrome during fetal MRI in the supine position - a retrospective analysis.

    Science.gov (United States)

    Kienzl, Daniela; Berger-Kulemann, Vanessa; Kasprian, Gregor; Brugger, Peter C; Weber, Michael; Bettelheim, Dieter; Pusch, Franz; Prayer, Daniela

    2014-05-01

    Inferior vena cava compression syndrome (VCCS) is a serious complication of supine fetal magnetic resonance imaging (MRI) examinations, particularly during late gestation. This morphologic study correlated the occurrence of VCCS with the grade of inferior vena cava (IVC) compression. There were 56 fetal MRI in the supine position [median gestational weeks (GW) 27+4] and 16 fetal MRI in the lateral position (median GW 30+6) retrospectively analyzed. The grade of maternal IVC compression was determined by the maximal anterior-posterior diameter (DAP) at the level of L4/L5. Fetal head position and right-sided uterus volume were analyzed. Clinical VCCS-related symptoms during fetal MRI were assessed. A noncompressed IVC was present in 1.8% (n=1) and a DAP of 5 to <10 mm in 33.3% (n=19) and 1 to <5 mm in 64.9% (n=36). The DAP was independent of fetal head position (P=0.99) and showed no significant correlation with gestational age (r=0.33). IVC compression increased with right-sided uterus volume (r=-0.328; P=0.014). There was a significant difference in DAP in the lateral position compared with the supine position (P<0.001). Clinical assessment revealed no symptoms of VCCS in any woman. The presented data support the concept of physiologic compensation for significantly reduced venous backflow in the supine position during the second and third trimesters of pregnancy.

  12. Evaluation of the integrity of the deltoid ligament in supination external rotation ankle fractures: a systematic review of the literature

    NARCIS (Netherlands)

    van den Bekerom, M.P.J.; Mutsaerts, E.L.A.R.; van Dijk, C.N.

    2009-01-01

    BACKGROUND AND PURPOSE: Review the literature concerning modalities to evaluate the integrity of the deltoid ligament in patients with supination external rotation ankle fractures. METHODS: The electronic databases Pubmed/Medline, CINAHL and Embase were searched from 1987 to November 2007 to identif

  13. Hip range of motion during daily activities in patients with posterior pelvic tilt from supine to standing position.

    Science.gov (United States)

    Tamura, Satoru; Miki, Hidenobu; Tsuda, Kosuke; Takao, Masaki; Hattori, Asaki; Suzuki, Naoki; Yonenobu, Kazuo; Sugano, Nobuhiko

    2015-04-01

    In most patients with hip disorders, the anterior pelvic plane (APP) sagittal tilt does not change from supine to standing position. However, in some patients, APP sagittal tilt changes more than 10° posteriorly from supine to standing position. The purpose of this study was to both examine APP sagittal tilt and investigate the hip flexion and extension range of motion (ROM) required during daily activities in these atypical patients. Patient-specific 4-dimensional (4D) motion analysis was performed for 50 hips from 44 patients who had undergone total hip arthroplasty. All patients divided into two categories, such as atypical patients for whom the pelvis tilted more than 10° posteriorly from supine to standing position preoperatively (19 hips from 18 patients) and the remaining typical patients (31 hips from 26 patients). The required hip flexion and extension angles did not differ significantly between atypical patients and typical patients. In conclusion, the hip flexion ROM during deep bending activities and hip extension ROM during extension activities required in those atypical patients with pelvic tilt more than 10° backward from supine to standing position did not shift in the direction of extension. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Uav Photogrammetry with Oblique Images: First Analysis on Data Acquisition and Processing

    Science.gov (United States)

    Aicardi, I.; Chiabrando, F.; Grasso, N.; Lingua, A. M.; Noardo, F.; Spanò, A.

    2016-06-01

    In recent years, many studies revealed the advantages of using airborne oblique images for obtaining improved 3D city models (e.g. including façades and building footprints). Expensive airborne cameras, installed on traditional aerial platforms, usually acquired the data. The purpose of this paper is to evaluate the possibility of acquire and use oblique images for the 3D reconstruction of a historical building, obtained by UAV (Unmanned Aerial Vehicle) and traditional COTS (Commercial Off-the-Shelf) digital cameras (more compact and lighter than generally used devices), for the realization of high-level-of-detail architectural survey. The critical issues of the acquisitions from a common UAV (flight planning strategies, ground control points, check points distribution and measurement, etc.) are described. Another important considered aspect was the evaluation of the possibility to use such systems as low cost methods for obtaining complete information from an aerial point of view in case of emergency problems or, as in the present paper, in the cultural heritage application field. The data processing was realized using SfM-based approach for point cloud generation: different dense image-matching algorithms implemented in some commercial and open source software were tested. The achieved results are analysed and the discrepancies from some reference LiDAR data are computed for a final evaluation. The system was tested on the S. Maria Chapel, a part of the Novalesa Abbey (Italy).

  15. UAV PHOTOGRAMMETRY WITH OBLIQUE IMAGES: FIRST ANALYSIS ON DATA ACQUISITION AND PROCESSING

    Directory of Open Access Journals (Sweden)

    I. Aicardi

    2016-06-01

    Full Text Available In recent years, many studies revealed the advantages of using airborne oblique images for obtaining improved 3D city models (e.g. including façades and building footprints. Expensive airborne cameras, installed on traditional aerial platforms, usually acquired the data. The purpose of this paper is to evaluate the possibility of acquire and use oblique images for the 3D reconstruction of a historical building, obtained by UAV (Unmanned Aerial Vehicle and traditional COTS (Commercial Off-the-Shelf digital cameras (more compact and lighter than generally used devices, for the realization of high-level-of-detail architectural survey. The critical issues of the acquisitions from a common UAV (flight planning strategies, ground control points, check points distribution and measurement, etc. are described. Another important considered aspect was the evaluation of the possibility to use such systems as low cost methods for obtaining complete information from an aerial point of view in case of emergency problems or, as in the present paper, in the cultural heritage application field. The data processing was realized using SfM-based approach for point cloud generation: different dense image-matching algorithms implemented in some commercial and open source software were tested. The achieved results are analysed and the discrepancies from some reference LiDAR data are computed for a final evaluation. The system was tested on the S. Maria Chapel, a part of the Novalesa Abbey (Italy.

  16. Upper airway collapse during drug induced sleep endoscopy: head rotation in supine position compared with lateral head and trunk position.

    Science.gov (United States)

    Safiruddin, Faiza; Koutsourelakis, Ioannis; de Vries, Nico

    2015-02-01

    Drug induced sedated sleep endoscopy (DISE) is often employed to determine the site, severity and pattern of obstruction in patients with sleep apnea. DISE is usually performed in supine position. We recently showed that the obstruction pattern is different when DISE is performed in lateral position. In this study, we compared the outcomes of DISE performed in supine position with head rotated, with the outcomes of DISE performed with head and trunk in lateral position. The Prospective study design was used in the present study. Sixty patients with OSA (44 male; mean apnea hypopnea index (AHI) 20.8 ± 17.5 events/h) underwent DISE under propofol sedation. Patients were placed in lateral position, and the upper airway collapse was evaluated. The patients were then placed in supine position with the head rotated to the right side. DISE outcomes were scored using the VOTE classification system. In lateral position, nine patients (15.0%) had a complete antero-posterior (A-P) collapse at the level of the velum, nine had a partial A-P collapse. During head rotation and trunk in supine position, at the level of the velum, four patients (6.7%) had a complete A-P collapse, while two patients (3.3%) had a partial A-P collapse. For all other sites, the patterns of collapse were not significantly different between head rotation and lateral position. During DISE, rotation of the head in supine position, and lateral head and trunk position present similar sites, severity and patterns of upper airway collapse, with the exception of collapse at the level of the velum. Here the severity of A-P collapse is less severe during head rotation than in lateral head and trunk position.

  17. Effect of reducing abdominal compression during prone CT colonography on ascending colonic rotation during supine-to-prone positional change

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jong eon; Park, Seong Ho; Lee, Jong Seok; Kim, Hyun Jin; KIm, Ah Young; Ha, Hyun Kwon [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2016-02-15

    To determine the effect of reduced abdominal compression in prone position on ascending colonic movement during supine-to-prone positional change during CT colonography (CTC). Eighteen consecutive patients who had undergone prone CTC scanning with cushion blocks placed under the chest and hip/thigh to reduce abdominal compression and had confirmed sessile polyps ≥ 6 mm in the well-distended, straight, mid-ascending colon, were included. Radial location along the ascending colonic luminal circumference (°) was measured for 24 polyps and 54 colonic teniae on supine and prone CTC images. The supine-to-prone change ranging between -180° and +180° (- and + for internal and external colonic rotations, respectively), was determined. In addition, possible causes of any ascending colonic rotations were explored. Abdominal compression during prone CTC scanning completely disappeared with the use of cushion blocks in 17 of 18 patients. However, some degrees of ascending colonic rotation were still observed, with the radial location changes of -22° to 61° (median, 13.9°) for the polyps and similar degrees for teniae. Fifty-four percent and 56% of polyps and teniae, respectively, showed changes > 10°. The radial location change of the polyps was significantly associated with the degree of anterior shift of the small bowel and mesentery (r = 0.722, p < 0.001) and the degree of posterior displacement of the ascending colon (r = 0.566, p = 0.004) during supine-to-prone positional change. Ascending colonic rotation upon supine-to-prone positional change during CTC, mostly in the form of external rotation, is not eliminated by removing abdominal compression in prone position.

  18. Women's positions during the second stage of labour: Views of primary care midwives

    NARCIS (Netherlands)

    Jonge, A. de; Teunissen, T.A.M.; Diem, M.T. van; Scheepers, P.L.H.; Lagro-Janssen, A.L.M.

    2008-01-01

    Aim. This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. Background. Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because offe

  19. Women's positions during the second stage of labour : views of primary care midwives

    NARCIS (Netherlands)

    Teunissen, Doreth A. M.; van Diem, Mariet Th.; Scheepers, Peer L. H.; Lagro-Janssen, Antoine L. M.

    2008-01-01

    Aim. This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. Background. Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because offe

  20. Women's positions during the second stage of labour: Views of primary care midwives

    NARCIS (Netherlands)

    Jonge, A. de; Teunissen, T.A.M.; Diem, M.T. van; Scheepers, P.L.H.; Lagro-Janssen, A.L.M.

    2008-01-01

    AIM: This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. BACKGROUND: Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because offe

  1. Women's positions during the second stage of labour : views of primary care midwives

    NARCIS (Netherlands)

    Teunissen, Doreth A. M.; van Diem, Mariet Th.; Scheepers, Peer L. H.; Lagro-Janssen, Antoine L. M.

    Aim. This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. Background. Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because

  2. Women's positions during the second stage of labour: Views of primary care midwives

    NARCIS (Netherlands)

    Jonge, A. de; Teunissen, T.A.M.; Diem, M.T. van; Scheepers, P.L.H.; Lagro-Janssen, A.L.M.

    2008-01-01

    AIM: This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. BACKGROUND: Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because

  3. Women's positions during the second stage of labour: Views of primary care midwives

    NARCIS (Netherlands)

    Jonge, A. de; Teunissen, T.A.M.; Diem, M.T. van; Scheepers, P.L.H.; Lagro-Janssen, A.L.M.

    2008-01-01

    Aim. This paper is a report of a study to explore the views of midwives on women's positions during the second stage of labour. Background. Many authors recommend encouraging women to use positions that are most comfortable to them. Others advocate encouragement of non-supine positions, because

  4. Direct oblique sagittal CT of orbital wall fractures

    Energy Technology Data Exchange (ETDEWEB)

    Ball, J.B. Jr.

    1987-03-01

    Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular muscle status, the nature and amount of displaced orbital contents, and an accurate definition of fracture margins. For orbital floor fractures, a combination of the direct oblique sagittal and direct coronal projections optimally displayed all fracture margins, the fracture's relationship to the inferior orbital rim and medial orbital wall, and the amount of displacement into the maxillary sinus. Inferior rectus muscle status with 36 floor fractures was best seen on the direct oblique sagittal projection in 30 fractures (83.3%) and was equally well seen on sagittal and coronal projections in two fractures (5.5%). Floor fractures were missed on 100% of axial, 5.5% of sagittal, and 0% of coronal projections. Since the direct oblique sagittal projection complements the direct coronal projection in evaluating orbital floor fractures, it should not be performed alone. A technical approach to the CT evaluation or orbital wall fractures is presented.

  5. Obliquely co-evaporated thin films for magnetic recording

    NARCIS (Netherlands)

    Kranenburg, van Herma

    1992-01-01

    A systematic research is carried out on obliquely ( co- ) evaporated media for magnetic recording applications. The investigated materials concern Co-alloys, being Co-Cr, Co-Ag and Co- Ta. The re1ations between deposition parameters, morphology , texture and rnagnetic behaviour were swdied. The acce

  6. Pulp Rotation Flap for Lateral Oblique Fingertip Defects.

    Science.gov (United States)

    Ozturk, Muhammed Besir; Barutca, Seda Asfuroglu; Aksan, Tolga; Atik, Bekir

    2016-11-01

    Fingertip amputations are among the most common injuries seen in the hand. According to the geometry of the amputation, it may be classified as transverse or oblique (dorsal, volar, or lateral type). Although numerous repair techniques have been described in the literature, there are few alternatives suitable for lateral oblique type fingertip amputations. Between 2012 and 2016, we operated on 16 patients with simple rotation flap from the remaining part of the pulpa in a rotation and advancement manner for the reconstruction of lateral oblique type fingertip amputations. All but two of the flaps healed completely with full flap survival. Superficial distal flap necrosis was observed in two patients. They healed by secondary intention. No obvious hooked nail occurred in patients. Cold intolerance was observed in one patient; joint stiffness or hypersensitivity was not observed in any of the patients. Stiffness of the proximal interphalangeal joint did not occur. Two point discrimination test results were found to be normal. This technique is simple, rapid, and free from relatively major complications. This flap allows for anatomical reconstruction of the fingertip by using a similar tissue in cases of lateral oblique fingertip amputations, where only a few flap options can be successful.

  7. Reorientation of magnetic anisotropy in obliquely sputtered metallic thin films

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.; Wormeester, H.; Poelsema, B.

    2002-01-01

    Reorientation in the magnetic anisotropy as a function of film thickness has been observed in Co-Ni and Co thin films, obliquely sputtered on a polyethylene terephthalate substrate at a large incidence angle (70°). This effect is a consequence of the low magnetocrystalline anisotropy of the films (f

  8. Measurement of ocular torsion variation following superior oblique tenectomy

    Directory of Open Access Journals (Sweden)

    Bruna Lana Ducca

    2014-12-01

    Full Text Available Purposes: To objectively evaluate the torsional effect of the superior oblique muscle-weakening surgery using the tenectomy technique proposed by Souza-Dias. Methods: The present prospective study included 10 patients (20 eyes with horizontal strabismus, bilateral superior oblique overaction and A-pattern of 15 to 30 prism diopters who underwent superior oblique tenectomy. Objective assessment of ocular torsion was performed by retinography immediately before and one month after surgery. The amount of ocular torsion was determined by measuring the angle formed by a horizontal line drawn across the geometric center of the optic disc and a second line connecting this point to the fovea. Results: The median preoperative angle was 5.56° in the right eyes and -3.43° in the left eyes. The median postoperative angle was 1.84° in the right eyes and -3.12° in the left eyes. The angle variation was statistically significant in both eyes (p=0.012 and p=0.01, respectively. Conclusion: The present study suggests that superior oblique tenectomy has an extorter effect, decreasing the intorsion detected on overaction of this muscle.

  9. Oblique water entry of a three dimensional body

    Directory of Open Access Journals (Sweden)

    Scolan Yves-Marie

    2014-12-01

    Full Text Available The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.

  10. Interaction of Oblique Incident Electromagnetic Wave with Relativistic Ionization Front

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Interactions of oblique incident probe wave with oncoming ionization fronts have been investigated using moving boundary conditions. Field conversion coefficients of reflection,transmission and magnetic modes produced in the interactions are derived. Phase matching conditions at the front and frequency up-shifting formulas for the three modes are also presented.

  11. Morphological development of coasts at very oblique wave incidence

    DEFF Research Database (Denmark)

    Petersen, Dorthe Pia; Deigaard, Rolf; Fredsøe, Jørgen

    2003-01-01

    This study focuses on one distinct feature to be found on coasts exposed to a very oblique wave incidence, namely an accumulating spit. That is a spit where no retreat of the shoreline is going on along the spit. This requires a monotonically decreasing sediment transport capacity from the updrift...

  12. Combined obliquity and precession pacing of late Pleistocene deglaciations.

    Science.gov (United States)

    Huybers, Peter

    2011-12-08

    Milankovitch proposed that Earth resides in an interglacial state when its spin axis both tilts to a high obliquity and precesses to align the Northern Hemisphere summer with Earth's nearest approach to the Sun. This general concept has been elaborated into hypotheses that precession, obliquity or combinations of both could pace deglaciations during the late Pleistocene. Earlier tests have shown that obliquity paces the late Pleistocene glacial cycles but have been inconclusive with regard to precession, whose shorter period of about 20,000 years makes phasing more sensitive to timing errors. No quantitative test has provided firm evidence for a dual effect. Here I show that both obliquity and precession pace late Pleistocene glacial cycles. Deficiencies in time control that have long stymied efforts to establish orbital effects on deglaciation are overcome using a new statistical test that focuses on maxima in orbital forcing. The results are fully consistent with Milankovitch's proposal but also admit the possibility that long Southern Hemisphere summers contribute to deglaciation.

  13. Calibrating the New Ultracam Osprey Oblique Aerial Sensor

    Science.gov (United States)

    Gruber, M.; Walcher, W.

    2014-03-01

    We present methods and results to calibrate the new oblique sensor UltraCam Osprey which was presented for the first time at the ASPRS 2013 conference and exhibition in Baltimore, MD, March 2013. Even if this was not the first time when oblique sensors were introduced into the market, the UltraCam Osprey did show several new conceptual details which are illustrated in this presentation. The design of the camera is focusing on two important characteristics, a metric nadir component which has been derived from the UltraCam Lp sensor, and collection efficiency through very large swath width. The nadir sensor consists of the 90 megapixel panchromatic camera, true-color RGB, and a near-infrared camera. Adding six oblique camera heads, with two each in forward and backwards direction, results in unmatched oblique collection efficiency. We first explain the camera and cone configuration along with the geometric layout of the sensor system. Then we describe the laboratory setup for geometric calibration of the UltraCam Osprey and the calibration process along with the actual results of one such calibration showing sub-pixel accurate image geometry. This proves that the UltraCam Osprey is a fully calibrated metric camera system suitable for photogrammetric survey applications.

  14. Oblique Aerial Imagery for NMA - Some best Practices

    Science.gov (United States)

    Remondino, F.; Toschi, I.; Gerke, M.; Nex, F.; Holland, D.; McGill, A.; Talaya Lopez, J.; Magarinos, A.

    2016-06-01

    Oblique airborne photogrammetry is rapidly maturing and being offered by service providers as a good alternative or replacement of the more traditional vertical imagery and for very different applications (Fig.1). EuroSDR, representing European National Mapping Agencies (NMAs) and research organizations of most EU states, is following the development of oblique aerial cameras since 2013, when an ongoing activity was created to continuously update its members on the developments in this technology. Nowadays most European NMAs still rely on the traditional workflow based on vertical photography but changes are slowly taking place also at production level. Some NMAs have already run some tests internally to understand the potential for their needs whereas other agencies are discussing on the future role of this technology and how to possibly adapt their production pipelines. At the same time, some research institutions and academia demonstrated the potentialities of oblique aerial datasets to generate textured 3D city models or large building block models. The paper provides an overview of tests, best practices and considerations coming from the R&D community and from three European NMAs concerning the use of oblique aerial imagery.

  15. Small bowel protection in IMRT for rectal cancer. A dosimetric study on supine vs. prone position

    Energy Technology Data Exchange (ETDEWEB)

    Koeck, Julia; Kromer, Katharina; Siebenlist, Kerstin; Mai, Sabine; Fleckenstein, Jens; Wenz, Frederik [University of Heidelberg, Department of Radiation Oncology, University Medical Center Mannheim, Mannheim (Germany); Lohr, Frank [Az. Ospedaliero-Universitaria di Modena, Unita Operativa di Radioterapia, Dipartimento di Oncologia, Modena (Italy); Baack, Tobias [GRN Clinic Weinheim, Department of Internal Medicine, Weinheim (Germany); Buettner, Sylvia [University of Heidelberg, Department of Biomathematics and Medical Statistics, University Medical Center Mannheim, Mannheim (Germany)

    2017-07-15

    This treatment planning study analyzes dose coverage and dose to organs at risk (OAR) in intensity-modulated radiotherapy (IMRT) of rectal cancer and compares prone vs. supine positioning as well as the effect of dose optimization for the small bowel (SB) by additional dose constraints in the inverse planning process. Based on the CT datasets of ten male patients in both prone and supine position, a total of four different IMRT plans were created for each patient. OAR were defined as the SB, bladder, and femoral heads. In half of the plans, two additional SB cost functions were used in the inverse planning process. There was a statistically significant dose reduction for the SB in prone position of up to 41% in the high and intermediate dose region, compared with the supine position. Furthermore, the femoral heads showed a significant dose reduction in prone position in the low dose region. Regarding the additional active SB constraints, the dose in the high dose region of the SB was significantly reduced by up to 14% with the additional cost functions. There were no significant differences in the dose distribution of the planning target volume (PTV) and the bladder. Prone positioning can significantly reduce dose to the SB in IMRT for rectal cancer and therefore should not only be used in 3D conformal radiotherapy but also in IMRT of rectal cancer. Further protection of the SB can be achieved by additional dose constraints in inverse planning without jeopardizing the homogeneity of the PTV. (orig.) [German] Diese Planungsstudie analysiert die Dosisverteilung im Zielvolumen und in den Risikoorganen (''organs at risk'', OAR) bei der intensitaetsmodulierten Strahlentherapie (''intensity-modulated radiotherapy'', IMRT) des Rektumkarzinoms und vergleicht hierbei Bauch- und Rueckenlagerung sowie die Effekte der Dosisoptimierung fuer den Duenndarm (DD) durch zusaetzliche Dosiseinschraenkungen bei der inversen Planung. Anhand der

  16. Association between CT-evaluated lumbar lordosis and features of spinal degeneration, evaluated in supine position

    Science.gov (United States)

    Kalichman, Leonid; Li, Ling; Hunter, David; Been, Ella

    2013-01-01

    Background Context Few studies have directly evaluated the association of lumbar lordosis and segmental wedging of the vertebral bodies and intervertebral disks with prevalence of spinal degenerative features. Purpose To evaluate the association of CT-evaluated lumbar lordosis, segmental wedging of the vertebral bodies and that of the intervertebral disks with various spinal degeneration features. Study design This cross-sectional study was a nested project to the Framingham Heart Study. Sample A random consecutive subset of 191 participants chosen from the 3590 participants enrolled in the Framingham Heart Study who underwent multi-detector CT to assess aortic calcification. Outcome Measures Physiologic Measures Dichotomous variables indicating the presence of intervertebral disc narrowing, facet joint osteoarthritis, spondylolysis, spondylolisthesis and spinal stenosis and density (in Hounsfield units) of multifidus and erector spinae muscles were evaluated on supine CT, as well as the lordosis angle (LA) and the wedging of the vertebral bodies and intervertebral disks. Sum of vertebral bodies wedging (ΣB) and sum of intervertebral discs wedging (ΣD) were used in analyses. Methods Mean values (±SD) of LA, ΣB and ΣD were calculated in males and females and compared using the t-test. Mean values (±SD) of LA, ΣB and ΣD in 4 age groups: 0.05) with increasing age. LA showed statistically significant association with presence of spondylolysis (OR(95%CI): 1.08(1.02–1.14)) and with density of multifidus (1.06 (1.01–1.11). as well as a marginally significant association with isthmic spondylolisthesis (1.07(1.00–1.14). ΣB showed a positive association with degenerative spondylolisthesis and disc narrowing ((1.14(1.06–1.23) and 1.04 (1.00–1.08), correspondingly), whereas ΣD showed negative one (0.93(0.87–0.98) and (0.93(0.89–0.97), correspondingly). Conclusions Significant associations were found between lumbar lordosis evaluated in supine position

  17. Supination external rotation ankle fractures A simpler pattern with better outcomes

    Directory of Open Access Journals (Sweden)

    Nirmal C Tejwani

    2015-01-01

    Full Text Available Background: Rotational injuries are the most common and usually classified as per the Lauge Hansen classification; with the most common subgroup being the supination external rotation (SER mechanism. Isolated fractures of the distal fibula (SE2 without associated ligamentous injury are usually treated with a splint or brace and the patient may be allowed to weight bear as tolerated. This study reports the functional outcomes following a stable, low energy, rotational ankle fracture supination external rotation (SER2 when compared to unstable SER4 fractures treated operatively. Materials and Methods: 64 patients who were diagnosed and treated nonoperatively for a stable SER2 ankle fracture were followed prospectively. In the comparison group, 93 operatively treated fibular fractures were extracted from a prospectively collected database and evaluated comparison. Baseline characteristics obtained by trained interviewers at the time of injury included: Patient demographics, short form-36, short musculoskeletal functional assessment (SMFA and American Orthopedic Foot and Ankle Society (AOFAS questionnaires. Patients were followed at 3, 6 and 12 months postsurgery. Additional information obtained at each followup point included any complications or evidence on fracture healing. Data were analyzed by the Student′s t-test and theFisher′s Exact Test to compare demographic and functional outcomes between the two cohorts. P < 0.05 was considered to be significant. Results: The average of patients′ age in the stable fracture cohort was 43 versus 45 in the SER4 group. Nearly 64% of the patient population was female when compared with 37% in the operative group. In the SER2 by 6 months all patients had returned to baseline functional status. There were 18 delayed unions (all healed by 6 months. Based on the functional outcome scores all patients had returned to preoperative level. In comparison, SE4 patients had less functional recovery at 3 and 6

  18. On complex roots of an equation arising in the oblique derivative problem

    Science.gov (United States)

    Kostin, A. B.; Sherstyukov, V. B.

    2017-01-01

    The paper is concerned with the eigenvalue problem for the Laplace operator in a disc under the condition that the oblique derivative vanishes on the disc boundary. In a famous article by V.A. Il’in and E.I. Moiseev (Differential equations, 1994) it was found, in particular, that the root of any equation of the form with the Bessel function Jn (μ) determines the eigenvalue λ = μ 2 of the problem. In our work we correct the information about the location of eigenvalues. It is specified explicit view of the corner, containing all the eigenvalues. It is shown that all the nonzero roots of the equation are simple and given a refined description of the set of their localization on the complex plane. To prove these facts we use the partial differential equations methods and also methods of entire functions theory.

  19. Full resonant transmission of semi-guided planar waves through slab waveguide steps at oblique incidence

    CERN Document Server

    Hammer, Manfred; Förstner, Jens

    2015-01-01

    Sheets of slab waveguides with sharp corners are investigated. By means of rigorous numerical experiments, we look at oblique incidence of semi-guided plane waves. Radiation losses vanish beyond a certain critical angle of incidence. One can thus realize lossless propagation through 90-degree corner configurations, where the remaining guided waves are still subject to pronounced reflection and polarization conversion. A system of two corners can be viewed as a structure akin to a Fabry-Perot-interferometer. By adjusting the distance between the two partial reflectors, here the 90-degree corners, one identifies step-like configurations that transmit the semi-guided plane waves without radiation losses, and virtually without reflections. Simulations of semi-guided beams with in-plane wide Gaussian profiles show that the effect survives in a true 3-D framework.

  20. Qual a melhor incidência radiográfica para avaliar o desvio das fraturas tipo die-punch? Estudo em cadáver What is the best radiographic view for "die punch" distal radius fractures? A cadaver model study

    Directory of Open Access Journals (Sweden)

    Diego Figueira Falcochio

    2012-02-01

    to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. CONCLUSION: The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees.

  1. Safety and efficacy of percutaneous nephrolithotomy in the Galdakao - Modified Supine Valdivia position: A prospective analysis

    Directory of Open Access Journals (Sweden)

    Luigi Quaresima

    2016-07-01

    Full Text Available Objective: Aim of the present study was to evaluate the safety and efficacy of Percutaneous Nephrolithotomy (PCNL in the Galdakao- Modified Supine Valdivia (GMSV position in order to predict operative time, stone-free rate and onset of complications taking into account comorbidity, stone-related parameters and anatomic upper urinary tract abnormalities. Material and methods: A prospective evaluation of patients who underwent to PCNL in GMSV position for renal stones > 2 cm, from January 2009 to February 2015 was performed. According to the technique, upper urinary tract abnormalities, stone chemical and morphological characteristics, and patients' history were matched with operative outcome, in terms of stone-free, intervention time and incidence of perioperative complications. Results: Seventy-two cases were collected; mean operative time was 105 minutes (DS 41: staghorn stones and the presence of comorbidity resulted statistically significant variables. The complication-rate resulted in line with data showed in literature: hyperpyrexia and hemorrhage were the more frequently complications found. The overall stone-free was reached in 48 patients (67%, and it was influenced by patients’ anatomic abnormalities. Conclusions: In the treatment of renal stones, PCNL may be a safe and effective choice; nevertheless, patients’ anatomic abnormalities or staghorn-stones may influence the outcomes. Thus, a prospective study with a larger population is needed to verify our outcomes.

  2. Heart rate variability during sleep following the practice of cyclic meditation and supine rest.

    Science.gov (United States)

    Patra, Sanjib; Telles, Shirley

    2010-06-01

    Day time activities are known to influence the sleep on the following night. Cyclic meditation (CM) has recurring cycles. Previously, the low frequency (LF) power and the ratio between low frequency and high frequency (LF/HF ratio) of the heart rate variability (HRV) decreased during and after CM but not after a comparable period of supine rest (SR). In the present study, on thirty male volunteers, CM was practiced twice in the day and after this the HRV was recorded (1) while awake and (2) during 6 h of sleep (based on EEG, EMG and EGG recordings). This was similarly recorded for the night's sleep following the day time practice of SR. Participants were randomly assigned to the two sessions and all of them practiced both CM and SR on different days. During the night following day time CM practice there were the following changes; a decrease in heart rate, LF power (n.u.), LF/HF ratio, and an increase in the number of pairs of Normal to Normal RR intervals differing by more than 50 ms divided by total number of all NN intervals (pNN50) (P < 0.05, in all cases, comparing sleep following CM compared with sleep following SR). No change was seen on the night following SR. Hence yoga practice during the day appears to shift sympatho-vagal balance in favor of parasympathetic dominance during sleep on the following night.

  3. Comparison of heart rate variability in supine, and left and right lateral positions.

    Science.gov (United States)

    Ryan, A D; Larsen, P D; Galletly, D C

    2003-05-01

    In order to determine whether differences exist in cardiac autonomic tone between different body positions that may be used in unconscious subjects, we examined beat-to-beat heart rate variability (HRV) in volunteers lying supine, and in left lateral and right lateral positions. We studied 24 subjects, aged 20-35 years in each of the three positions on one study day, and 6 subjects in each of the three positions on each of six different study days. In both groups of subjects we observed no difference in heart rate, respiratory frequency, total power (0.02-0.45 Hz) of HRV or the proportion of power in the high (0.15-0.45 Hz), low (0.08-0.15 Hz) or very low (0.02-0.08 Hz) frequency bands among the three positions. These results suggest that there are no cardiac autonomic tone advantages to be gained by placing a person in the recovery position on one side compared with the other.

  4. Experimental investigation of the visual field dependency in the erect and supine positions

    Science.gov (United States)

    Lichtenstein, J. H.; Saucer, R. T.

    1972-01-01

    The increasing utilization of simulators in many fields, in addition to aeronautics and space, requires the efficient use of these devices. It seemed that personnel highly influenced by the visual scene would make desirable subjects, particularly for those simulators without sufficient motion cues. In order to evaluate this concept, some measure of the degree of influence of the visual field on the subject in necessary. As part of this undertaking, 37 male and female subjects, including eight test pilots, were tested for their visual field dependency or independency. A version of Witkin's rod and frame apparatus was used for the tests. The results showed that nearly all the test subjects exhibited some degree of field dependency, the degree varying from very high field dependency to nearly zero field dependency in a normal distribution. The results for the test pilots were scattered throughout a range similar to the results for the bulk of male subjects. The few female subjects exhibited a higher field dependency than the male subjects. The male subjects exhibited a greater field dependency in the supine position than in the erect position, whereas the field dependency of the female subjects changed only slightly.

  5. Accuracy Potential and Applications of MIDAS Aerial Oblique Camera System

    Science.gov (United States)

    Madani, M.

    2012-07-01

    Airborne oblique cameras such as Fairchild T-3A were initially used for military reconnaissance in 30s. A modern professional digital oblique camera such as MIDAS (Multi-camera Integrated Digital Acquisition System) is used to generate lifelike three dimensional to the users for visualizations, GIS applications, architectural modeling, city modeling, games, simulators, etc. Oblique imagery provide the best vantage for accessing and reviewing changes to the local government tax base, property valuation assessment, buying & selling of residential/commercial for better decisions in a more timely manner. Oblique imagery is also used for infrastructure monitoring making sure safe operations of transportation, utilities, and facilities. Sanborn Mapping Company acquired one MIDAS from TrackAir in 2011. This system consists of four tilted (45 degrees) cameras and one vertical camera connected to a dedicated data acquisition computer system. The 5 digital cameras are based on the Canon EOS 1DS Mark3 with Zeiss lenses. The CCD size is 5,616 by 3,744 (21 MPixels) with the pixel size of 6.4 microns. Multiple flights using different camera configurations (nadir/oblique (28 mm/50 mm) and (50 mm/50 mm)) were flown over downtown Colorado Springs, Colorado. Boresight fights for 28 mm nadir camera were flown at 600 m and 1,200 m and for 50 mm nadir camera at 750 m and 1500 m. Cameras were calibrated by using a 3D cage and multiple convergent images utilizing Australis model. In this paper, the MIDAS system is described, a number of real data sets collected during the aforementioned flights are presented together with their associated flight configurations, data processing workflow, system calibration and quality control workflows are highlighted and the achievable accuracy is presented in some detail. This study revealed that the expected accuracy of about 1 to 1.5 GSD (Ground Sample Distance) for planimetry and about 2 to 2.5 GSD for vertical can be achieved. Remaining systematic

  6. Immobilization in supination versus neutral following surgical treatment of Galeazzi fracture-dislocations in adults: case series.

    Science.gov (United States)

    Park, Min Jung; Pappas, Nick; Steinberg, David R; Bozentka, David J

    2012-03-01

    The goal of this study was to investigate whether immobilization in supination is necessary to prevent recurrent distal radioulnar joint (DRUJ) instability in patients older than 18 years with a Galeazzi fracture-dislocation and a stable DRUJ following open reduction and internal fixation of the radius. We performed a retrospective chart review of 10 consecutive patients who were immobilized in either supination or a neutral position following surgical treatment of a Galeazzi fracture-dislocation in which the DRUJ was noted to be stable immediately after fixation of the radius. Group 1 consisted of 5 patients who were immobilized in supination for a period of 4 weeks, and group 2 consisted of 5 patients who were immobilized in neutral for 2 weeks, followed by functional bracing. Patients were followed up for an average of 68 months (range, 26-124 mo) after surgery. No significant difference was noted between the 2 groups with respect to age, medical comorbidities (no noteworthy medical comorbidities in either group), or hand dominance. None of the patients in either group demonstrated DRUJ instability during the follow-up period or required any additional surgery. At the latest follow-up, patients in the 2 groups had comparable forearm motion. The results of the current study suggest that following open reduction and internal fixation of the radius in patients with Galeazzi fracture-dislocations and with stable DRUJs, immobilization in supination for 4 weeks does not have an advantage over immobilization in neutral for a shorter period. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  7. SU-E-T-255: Optimized Supine Craniospinal Irradiation with Image-Guided and Field Matched Beams

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Z; Holupka, E; Naughton, J; Williams, H; Galper, S; Huang, K [Beth Israel Deaconess Medical Center, Boston, MA (Israel)

    2014-06-01

    Purpose: Conventional craniospinal irradiation (CSI) challenges include dose inhomogeneity at field junctions and position uncertainty due to the field divergence, particular for the two spinal fields. Here we outline a new supine CSI technique to address these difficulties. Methods: Patient was simulated in supine position. The cranial fields had isocenter at C2/C3 vertebral and were matched with 1st spinal field. Their inferior border was chosen to avoid the shoulder, as well as chin from the 1st spine field. Their collimator angles were dependent on asymmetry jaw setting of the 1st spinal field. With couch rotation, the spinal field gantry angles were adjusted to ensure, the inferior border of 1st and superior border of 2nd spinal fields were perpendicular to the table top. The radio-opaque wire position for the spinal junction was located initially by the light field from an anterior setup beam, and was finalized by the portal imaging of the 1st spinal field. With reference to the spinal junction wire, the fields were matched by positioning the isocenter of the 2nd spinal field. A formula was derived to optimize supine CSI treatment planning, by utilizing the relationship among the Yjaw setting, the spinal field gantry angles, cranial field collimator angles, and the spinal field isocenters location. The plan was delivered with portal imaging alignment for the both cranial and spinal junctions. Results: Utilizing this technique with matching beams, and conventional technique such as feathering and forwarding planning, a homogenous dose distribution was achieved throughout the entire CSI treatment volume including the spinal junction. Placing the spinal junction wire visualized in both spinal portals, allows for precise determination and verification of the appropriate match line of the spine fields. Conclusion: This technique of optimization supine CSI achieved a homogenous dose distributions and patient localization accuracy with image-guided and matched beams.

  8. Prospective Assessment of Optimal Individual Position (Prone Versus Supine) for Breast Radiotherapy: Volumetric and Dosimetric Correlations in 100 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Lymberis, Stella C.; Wyngaert, John Keith de; Parhar, Preeti; Chhabra, Arpit M.; Fenton-Kerimian, Maria; Chang Jengwha [Department of Radiation Oncology, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Hochman, Tsivia [Division of Biostatistics, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Department of Environmental Medicine, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Guth, Amber; Roses, Daniel [Department of Surgery, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Goldberg, Judith D. [Division of Biostatistics, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Department of Environmental Medicine, New York University School of Medicine and Langone Medical Center, New York, New York (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine and Langone Medical Center, New York, New York (United States)

    2012-11-15

    Purpose: Damage to heart and lung from breast radiotherapy is associated with increased cardiovascular mortality and lung cancer development. We conducted a prospective study to evaluate which position is best to spare lung and heart from radiotherapy exposure. Methods and Materials: One hundred consecutive Stage 0-IIA breast cancer patients consented to participate in a research trial that required two computed tomography simulation scans for planning both supine and prone positions. The optimal position was defined as that which best covered the contoured breast and tumor bed while it minimized critical organ irradiation, as quantified by the in-field heart and lung volume. The trial was designed to plan the first 100 patients in each position to study correlations between in-field volumes of organs at risk and dose. Results: Fifty-three left and 47 right breast cancer patients were consecutively accrued to the trial. In all patients, the prone position was optimal for sparing lung volume compared to the supine setup (mean lung volume reduction was 93.5 cc for right and 103.6 cc for left breast cancer patients). In 46/53 (87%) left breast cancer patients best treated prone, in-field heart volume was reduced by a mean of 12 cc and by 1.8 cc for the other 7/53 (13%) patients best treated supine. As predicted, supine-prone differences in in-field volume and mean dose of heart and lung were highly correlated (Spearman's correlation coefficient for left breast cancer patients was 0.90 for heart and 0.94 for lung and 0.92 for right breast cancer patients for lung). Conclusions: Prone setup reduced the amount of irradiated lung in all patients and reduced the amount of heart volume irradiated in 87% of left breast cancer patients. In-field organ volume is a valid surrogate for predicting dose; the trial continued to the planned target of 400.

  9. The effect of age on sagittal plane profile of the lumbar spine according to standing, supine, and various sitting positions

    Science.gov (United States)

    2014-01-01

    Background The sagittal alignment of the spine changes depending on body posture and degenerative changes. This study aimed to observe changes in sagittal alignment of the lumbar spine with different positions (standing, supine, and various sitting postures) and to verify the effect of aging on lumbar sagittal alignment. Methods Whole-spine lateral radiographs were obtained for young volunteers (25.4 ± 2.3 years) and elderly volunteers (66.7 ± 1.7 years). Radiographs were obtained in standing, supine, and sitting (30°, 60°, and 90°) positions respectively. We compared the radiological changes in the lordotic and segmental angles in different body positions and at different ages. Upper and lower lumbar lordosis were defined according to differences in anatomical sagittal mobility and kinematic behavior. Results Lumbar lordosis was greater in a standing position (52.79° and 53.90° in young and old groups, respectively) and tended to decrease as position changed from supine to sitting. Compared with the younger group, the older group showed significantly more lumbar lordosis in supine and 60° and 90° sitting positions (P = 0.043, 0.002, 0.011). Upper lumbar lordosis in the younger group changed dynamically in all changed positions compared with the old group (P = 0.019). Lower lumbar lordosis showed a decreasing pattern in both age groups, significantly changing as position changed from 30° to 60° (P = 0.007, 0.007). Conclusions Lumbar lordosis decreases as position changes from standing to 90°sitting. The upper lumbar spine is more flexible in individuals in their twenties compared to those in their sixties. Changes in lumbar lordosis were concentrated in the lower lumbar region in the older group in sitting positions. PMID:24571953

  10. Frontal and oblique tectonics in the Brazilian Shield

    Institute of Scientific and Technical Information of China (English)

    GinaldoA.daC.Campanha; BenjamimBleydeBritoNeves

    2004-01-01

    The Brazilian shield was assembled from a few Archean and Paleoproterozoic cratonic nuclei surrounded by Pan-African-Brasiliano mobile belts of Neoproterozoic age. While some of these mobile belts display a typical frontal collision tectonic style, others are dominated by transcurrent regimes, clearly indicating oblique collisional systems. This paper is an attempt to determine the mean orientation of the principal horizontal compressive stresses for each mobile belt, considering either the frontal or oblique convergence character. From these general observations a scheme with WNW - ESE to NWSE trends of the main compressive stress is proposed. We suggest that this trend represents the mean displacement vectors, according to a coherent kinematic picture for the amalgamation of the West Gondwana during the final stages of convergence of the Brasiliano belts, where WNW-ESE to NW-SE are the main directions of final closure.

  11. Whistler damping at oblique propagation - Laminar shock precursors

    Science.gov (United States)

    Gary, S. P.; Mellott, M. M.

    1985-01-01

    This paper addresses the collisionless damping of whistlers observed as precursors standing upstream of oblique, low-Mach number terrestrial bow shocks. The linear theory of electromagnetic waves in a homogeneous Vlasov plasma with Maxwellian distribution functions and a magnetic field is considered. Numerical solutions of the full dispersion equation are presented for whistlers propagating at an arbitrary angle with respect to the magnetic field. It is demonstrated that electron Landau damping attenuates oblique whistlers and that the parameter which determines this damping is beta-e. In a well-defined range of parameters, this theory provides damping lengths which are the same order of magnitude as those observed. Thus electron Landau damping is a plausible process in the dissipation of upstream whistlers. Nonlinear plasma processes which may contribute to precursor damping are also discussed, and criteria for distinguishing among these are described.

  12. Oblique Laminar-Turbulent Interfaces in Plane Shear Flows

    Science.gov (United States)

    Duguet, Yohann; Schlatter, Philipp

    2013-01-01

    Localized structures such as turbulent stripes and turbulent spots are typical features of transitional wall-bounded flows in the subcritical regime. Based on an assumption for scale separation between large and small scales, we show analytically that the corresponding laminar-turbulent interfaces are always oblique with respect to the mean direction of the flow. In the case of plane Couette flow, the mismatch between the streamwise flow rates near the boundaries of the turbulence patch generates a large-scale flow with a nonzero spanwise component. Advection of the small-scale turbulent fluctuations (streaks) by the corresponding large-scale flow distorts the shape of the turbulence patch and is responsible for its oblique growth. This mechanism can be easily extended to other subcritical flows such as plane Poiseuille flow or Taylor-Couette flow.

  13. Tidal Dissipation and Obliquity Evolution in Hot Jupiter Systems

    CERN Document Server

    Valsecchi, Francesca

    2014-01-01

    Two formation scenarios have been proposed to explain the tight orbits of hot Jupiters. These giant planets could be formed in low-obliquity orbits via disk migration or in high-obliquity orbits via high-eccentricity migration, where gravitational interactions with a companion are at play, together with tidal dissipation. Here we target the observed misaligned hot Jupiter systems to investigate whether their current properties are consistent with high-eccentricity migration. Specifically, we study whether tidal dissipation in the star can be responsible for the observed distribution of misalignments and orbital separations. Improving on previous studies, we use detailed models for the stellar component, thus accounting for how convection (and thus tidal dissipation) depends on the host star properties. We find that the currently observed degree of misalignment increases as the amount of surface convection in the host star decreases. This trend supports the hypothesis that tides are the mechanism shaping the o...

  14. Impact of an oblique breaking wave on a wall

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    The intention of this paper is to study impact force of an oblique-angled slamming wave acting on a rigid wall. In the present study the analytical approach is pursued based on a technique proposed by the author. A nonlinear theory in the context of potential flow is presented for determining accurately the free-surface profiles immediately after an oblique breaking wave impingement on the rigid vertical wall that suddenly starts from rest. The small-time expansion is taken as far as necessary to include the accelerating effect. The analytical solutions for the free-surface elevation are derived up to the third order. The results derived in this paper are of particular interest to the marine and offshore engineering industries, which will find the information useful for the design of ships, coastal and offshore.

  15. Tree level unitarity and finiteness of electroweak oblique corrections

    CERN Document Server

    Nagai, Ryo

    2015-01-01

    We study perturbative unitarity and electroweak oblique corrections in the electroweak symmetry breaking models including an arbitrary number of neutral Higgs bosons. Requiring the perturbative unitarity of the high energy scattering amplitudes of weak gauge bosons and the neutral Higgs bosons at tree level, we obtain a set of conditions among the Higgs coupling strengths (unitarity sum rules). It is shown that the unitarity sum rules require the tree level rho parameter to be 1 if there are only neutral Higgs bosons. Moreover, we find that the one-loop finiteness of the electroweak oblique corrections is automatically guaranteed once the unitarity sum rules are imposed among the Higgs coupling strengths. Applying the unitarity sum rules, we obtain severe constraints on the mass of the second lightest neutral Higgs boson and the lightest neutral Higgs (a 125GeV Higgs) coupling strength from the results of the electroweak precision tests as well as the unitarity.

  16. Oblique Alfvén instabilities driven by compensated currents

    Energy Technology Data Exchange (ETDEWEB)

    Malovichko, P. [Main Astronomical Observatory, NASU, Kyiv (Ukraine); Voitenko, Y.; De Keyser, J., E-mail: voitenko@oma.be [Solar-Terrestrial Centre of Excellence, Space Physics Division, Belgian Institute for Space Aeronomy, Ringlaan-3-Avenue Circulaire, B-1180 Brussels (Belgium)

    2014-01-10

    Compensated-current systems created by energetic ion beams are widespread in space and astrophysical plasmas. The well-known examples are foreshock regions in the solar wind and around supernova remnants. We found a new oblique Alfvénic instability driven by compensated currents flowing along the background magnetic field. Because of the vastly different electron and ion gyroradii, oblique Alfvénic perturbations react differently on the currents carried by the hot ion beams and the return electron currents. Ultimately, this difference leads to a non-resonant aperiodic instability at perpendicular wavelengths close to the beam ion gyroradius. The instability growth rate increases with increasing beam current and temperature. In the solar wind upstream of Earth's bow shock, the instability growth time can drop below 10 proton cyclotron periods. Our results suggest that this instability can contribute to the turbulence and ion acceleration in space and astrophysical foreshocks.

  17. Effects of varying obliquity on Martian sublimation thermokarst landforms

    Science.gov (United States)

    Dundas, Colin M.

    2017-01-01

    Scalloped depressions in the Martian mid-latitudes are likely formed by sublimation of ice-rich ground. The stability of subsurface ice changes with the planetary obliquity, generally becoming less stable at lower axial tilt. As a result, the relative rates of sublimation and creep change over time. A landscape evolution model shows that these variations produce internal structure in scalloped depressions, commonly in the form of arcuate ridges, which emerge as depressions resume growth after pausing or slowing. In other scenarios, the formation of internal structure is minimal. Significant uncertainties in past climate and model parameters permit a range of scenarios. Ridges observed in some Martian scalloped depressions could date from obliquity lows or periods of low ice stability occurring <5 Ma, suggesting that the pits are young features and may be actively evolving.

  18. Competing magnetic anisotropies in obliquely deposited thin permalloy film

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, B.A. [Siberian Federal University, 79, pr. Svobodnyi, Krasnoyarsk 660041 (Russian Federation); Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, 50/38, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Reshetnev Siberian State Aerospace University, 31, pr. Imeni Gazety “Krasnoyarskii Rabochii”, Krasnoyarsk 660014 (Russian Federation); Izotov, A.V. [Siberian Federal University, 79, pr. Svobodnyi, Krasnoyarsk 660041 (Russian Federation); Kirensky Institute of Physics, Siberian Branch of the Russian Academy of Sciences, 50/38, Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Solovev, P.N., E-mail: platon.solovev@gmail.com [Siberian Federal University, 79, pr. Svobodnyi, Krasnoyarsk 660041 (Russian Federation)

    2016-01-15

    Distribution of the magnetic anisotropy in thin film prepared by thermal vacuum oblique deposition of permalloy with small off-normal angle of incident in the presence of an external magnetic field has been studied by ferromagnetic resonance technique. On local area of the sample, a mutual compensation of near orthogonal in-plane uniaxial magnetic anisotropies induced by oblique deposition and by applied magnetic field has been found. Moreover, in addition to the uniaxial (twofold) magnetic anisotropy, fourfold and sixfold magnetic anisotropies have been observed in the sample. To explain the obtained high-order anisotropies, we assumed that the sample has exchange coupled adjacent regions or phases with different parameters of magnetic anisotropy. The results of the micromagnetic analysis of a two-layer model of the sample confirm the hypothesis.

  19. Oblique drop impact onto a deep liquid pool

    CERN Document Server

    Gielen, Marise V; Benschop, Jos; Riepen, Michel; Voronina, Victoria; Lohse, Detlef; Snoeijer, Jacco H; Versluis, Michel; Gelderblom, Hanneke

    2016-01-01

    Oblique impact of drops on a solid or liquid surface is frequently observed in nature. Most studies on drop impact and splashing, however, focus on perpendicular impact. Here, we study oblique impact onto a deep liquid pool, where we quantify the splashing threshold, maximal cavity dimensions and cavity collapse by high-speed imaging above and below the water surface. Three different impact regimes are identified: smooth deposition onto the pool, splashing in the direction of impact only, and splashing in all directions. We provide scaling arguments that delineate these regimes by accounting for drop impact angle and Weber number. The angle of the axis of the cavity created below the water surface follows the impact angle of the drop independent of the Weber number, while cavity depth and its displacement with respect to the impact position depend on the Weber number. Weber number dependency of both the cavity depth and displacement is modeled using an energy argument.

  20. Supine spinal magnetic resonance imaging with straightened lower extremities in spondylolisthesis: A comparison with the conventional technique

    Energy Technology Data Exchange (ETDEWEB)

    Daghighi, Mohammad Hossein; Poureisa, Masoud; Arablou, Farid [Department of Radiology, Imam Reza Teaching Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Fouladi, Daniel F., E-mail: medicorelax@yahoo.com [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2015-05-15

    Highlights: • MR imaging with straightened lower extremities was tested in spondylolisthesis. • This technique is more accurate than conventional MR imaging in detecting slip. • Level of spondylolisthesis is the only independent predictor of severity of slip. - Abstract: Objectives: To compare the degree of slip in spondylolisthesis on supine magnetic resonance (MR) images obtained with flexed and straightened lower extremities. Methods: Supine spinal MR studies were performed in 100 cases of symptomatic spondylolisthesis with flexed and then straightened lower extremities. The angle of lumbar lordosis (by Cobb's method) and the degree of slip (by Taillard's method) were compared between the two sets of images. Results: The mean angle of lumbar lordosis increased from 51.65 ± 8.57° on MR images with flexed lower limbs to 57.39 ± 9.05° on MR images with straightened lower limbs (p < 0.001; mean percent increase: 11.51%). Similar change was also observed for the mean degree of slip (from 25.80 ± 7.74% to 28.68 ± 7.93%, p < 0.001; mean percent increase: 12.60%). After MR imaging with straightened lower extremities 22 out of 54 initially grade I cases had grade II disease (p < 0.001). Conclusions: Supine magnetic resonance imaging with straightened lower extremities detects higher degree of slippage in symptomatic patients with spondylolisthesis compared to conventional MRI with flexed lower extremities.

  1. Measurement of hemothorax amount in patients with non-penetrating chest trauma by supine chest AP radiograph

    Energy Technology Data Exchange (ETDEWEB)

    Han, Heon; Yang, Joo Hyun; Na, Myung Hoon; Baik, Hee Jong [Chung-Ang Gil Hospital, Incheon (Korea, Republic of)

    1994-10-15

    To evaluate the predictability of amount of hemothorax in the patients with blunt chest trauma, supine chest AP radiographs of 66 patients were reviewed and statistically analyzed. In 66 patients, rib fractures were present in 53 patients, hemothorax in 46 patients, pneumothorax in 25 patients, and pulmonary contusions in 18 patients. Width and length of hemothorax were measured on supine chest AP radiograph, and were correlated with known drained amount of hemothorax. The presence and number of rib fracture, pulmonary contusion, subcutaneous emphysema, fracture of scapula and clavicle, and total opacification of hemithorax were also correlated with the drained amount of hemothorax. In multiple logistic regression analysis, width of hemothorax had the highest correlation with drained amount of hemothorax(regression coeffcient 0.718, p value 0.00005). The presence and number of rib fracture, scapular fracture, subcutaneous emphysema were also correlated with drained amount of hemothorax. But length of hemothorax, pulmonary contusion, clavicular fracture, total opacification of hemithorax were not correlated with drained amount of hemothorax. Measured width of hemothorax in supine chest AP radiograph is the most reliable predictor for estimation of the amount of hemothorax, and may also be used as an indication for the application of closed thoracostomy in the treatment of hemothorax.

  2. Changes in T2-weighted MRI of supinator muscle, pronator teres muscle, and extensor indicis muscle with manual muscle testing

    Science.gov (United States)

    Yoshida, Kazuya; Akiyama, Sumikazu; Takamori, Masayoshi; Otsuka, D. Eng, Hiroshi; Seo, Yoshiteru

    2017-01-01

    [Purpose] In order to detect muscle activity with manual muscle testing, T2-weighted magnetic resonance (T2w-MR) images were detected by a 0.2 T compact MRI system. [Subjects and Methods] The subjects were 3 adult males. Transverse T2-weighted multi-slice spin-echo images of the left forearm were measured by a 39 ms echo-time with a 2,000 ms repetition time, a 9.5 mm slice thickness, 1 accumulation and a total image acquisition time of 4 min 16 s. First, T2w-MR images in the resting condition were measured. Then, manipulative isometric contraction exercise (5 sec duration) to the supinator muscle, the pronator teres muscle or the extensor indicis muscle was performed using Borg’s rating of perceived exertion (RPE) scale of 15–17. The T2w-MR images were measured immediately after the exercise. [Results] T2w-MR image intensities increased significantly in the supinator muscle, the pronator teres muscle and the extensor indicis muscle after the exercise. However, the image intensities in the rest of the muscle did not change. [Conclusion] Using T2w-MR images, we could detect muscle activity in a deep muscle, the supinator muscle, and a small muscle, the extensor indicis muscle. These results also support the reliability of the manual muscle testing method. PMID:28356621

  3. Pitch angle scattering of energetic particles by oblique whistler waves

    Science.gov (United States)

    Inan, U. S.; Bell, T. F.

    1991-01-01

    First order cyclotron or Landau resonant pitch angle scattering of electrons by oblique whistler waves propagating at large angles to the ambient field are found to be at least as large as that due to parallel propagating waves. Commonly observed precipitation of more than 40 keV electrons in association with ducted whistlers may thus be accompanied by substantial fluxes of lower energy (10 eV-40 keV) electrons precipitated by the nonducted components.

  4. Obliquity of the Stapes in Otosclerosis: A New Radiological Sign

    Directory of Open Access Journals (Sweden)

    Anand, Veluswamy

    2016-03-01

    Full Text Available Introduction Observing the obliquity of stapes by closely scrutinizing the HRCT temporal bone in otosclerosis revealed a reliable and consistent finding. This finding can add to the existing radiological criteria in diagnosis of otosclerosis. Objective The objective of this study is to establish the obliquity of stapes in otosclerosis by radiological measurements using HRCT temporal bone by comparing: (a the distance between the horizontal (tympanic segment of facial nerve and stapes head in otosclerotic ears (study group with non-otosclerotic ears (control group; and (b the angle subtended by stapes with promontory in the study and control groups. Methods This is a prospective study performed after the institutional Ethics Committee clearance (IEC 3/2013. Results An increased mean distance between the horizontal segment of facial nerve and stapes head in otosclerotic patients (i.e., 2.49mm +/− 0.24mm SD, when compared with the non-otosclerotic patients (i.e., 1.46mm +/− 0.16mm SD is noted. There is a change in angle (i.e., 64.550 +/− 7.190 SD subtended by the stapes toward the promontory in otosclerotic ears when compared with that of controls (i.e., 99.700 +/− 40 SD. We applied the Mann-Whitney U non-parametric test and considered p value of < 0.0001 highly significant. Conclusions Obliquity of stapes in otosclerosis referred to as a “Pisa” sign by the senior author has diagnostic value as a new radiological sign in imaging of otosclerosis. This obliquity explains the torsional effect of otosclerosis on the ossicular chain. The findings correlate with late complications and failures in stapes surgery.

  5. D Model Generation Using Oblique Images Acquired by Uav

    Science.gov (United States)

    Lingua, A.; Noardo, F.; Spanò, A.; Sanna, S.; Matrone, F.

    2017-07-01

    In recent years, many studies revealed the advantages of using airborne oblique images for obtaining improved 3D city models (including façades and building footprints). Here the acquisition and use of oblique images from a low cost and open source Unmanned Aerial Vehicle (UAV) for the 3D high-level-of-detail reconstruction of historical architectures is evaluated. The critical issues of such acquisitions (flight planning strategies, ground control points distribution, etc.) are described. Several problems should be considered in the flight planning: best approach to cover the whole object with the minimum time of flight; visibility of vertical structures; occlusions due to the context; acquisition of all the parts of the objects (the closest and the farthest) with similar resolution; suitable camera inclination, and so on. In this paper a solution is proposed in order to acquire oblique images with one only flight. The data processing was realized using Structure-from-Motion-based approach for point cloud generation using dense image-matching algorithms implemented in an open source software. The achieved results are analysed considering some check points and some reference LiDAR data. The system was tested for surveying a historical architectonical complex: the "Sacro Mo nte di Varallo Sesia" in north-west of Italy. This study demonstrates that the use of oblique images acquired from a low cost UAV system and processed through an open source software is an effective methodology to survey cultural heritage, characterized by limited accessibility, need for detail and rapidity of the acquisition phase, and often reduced budgets.

  6. Primary and secondary overacting inferior oblique muscles: an ultrastructural study.

    OpenAIRE

    Meyer, E.; Ludatscher, R. M.; Zonis, S

    1984-01-01

    Biopsy material from primary and secondary overacting inferior oblique muscles were examined by light and electron microscopy. Most muscle fibres were in different stages of atrophy. A high variation of alterations was encountered in all muscles. The most striking abnormalities were huge accumulations of mitochondria and muscle vacuolisation related mainly to the enlargement of the tubules of sarcoplasmic reticulum. The mitochondrial aggregates and vacuolisation occupied more muscle surface i...

  7. Optimal fixation of oblique scaphoid fractures: a cadaver model.

    Science.gov (United States)

    Luria, Shai; Lenart, Lado; Lenart, Borut; Peleg, Eran; Kastelec, Matej

    2012-07-01

    Acute scaphoid fractures are commonly fixed with headless cannulated screws positioned in the center of the proximal fragment. Central placement of the screw may be difficult and may violate the scaphotrapezial joint. We hypothesize that placement of the screw through the scaphoid tuberosity will achieve perpendicular fixation of an oblique waist fracture and result in more stable fixation than a screw in the center of the proximal fragment. We designed oblique osteotomies for 8 matched pairs of cadaver scaphoids and fixed each specimen with a headless cannulated screw. In 1 specimen, we positioned the screw at the center of the proximal fragment; we placed its matched pair perpendicular to the fracture. The perpendicular screw was directed through the scaphoid tuberosity. We placed the specimen under the increasing load of a pneumatically driven plunger. We compared stiffness, load, distance at failure, and mechanism of failure between the central and perpendicular screw groups. We found no difference between groups. Stiffness was identical in both groups (131 N/mm) and load to failure was similar (central screw, 137 N vs perpendicular screw, 148 N). In this biomechanical model of an unstable scaphoid fracture, we found that similar stability of fixation had been achieved with a screw perpendicular to the fracture plane with entry through the tuberosity, compared with a screw in a central position in the proximal fragment. This study suggests that placing the screw through the tuberosity, perpendicular to a short oblique fracture, will not impair fixation stability. Percutaneous fixation of scaphoid fractures has become popular although it is technically challenging. An easier distal approach through the tuberosity, without violating the scaphotrapezial joint, may not impair the fixation stability of an oblique fracture. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  8. The oblique S parameter in higgsless electroweak models

    CERN Document Server

    Rosell, Ignasi

    2012-01-01

    We present a one-loop calculation of the oblique S parameter within Higgsless models of electroweak symmetry breaking. We have used a general effective Lagrangian with at most two derivatives, implementing the chiral symmetry breaking SU(2)_L x SU(2)_R -> SU(2)_{L+R} with Goldstones, gauge bosons and one multiplet of vector and axial-vector resonances. The estimation is based on the short-distance constraints and the dispersive approach proposed by Peskin and Takeuchi.

  9. Effect of bilateral superior oblique split lengthening on torsion

    Directory of Open Access Journals (Sweden)

    Jitendra Jethani

    2015-01-01

    Full Text Available Introduction: Superior oblique split lengthening (SOSL is done for weakening of superior oblique. It corrects the superior oblique overaction (SOOA and A pattern. Its effect on the torsion of the eye is not known. We present our data on the effect of this particular procedure on torsion. Materials and Methods: We did a study of 16 patients (32 eyes who underwent bilateral SOSL and compared the disc foveal angle (DFA preoperatively and postoperatively. The split lengthening was done from 4 mm to 7 mm depending upon the overaction of superior oblique. Results: The mean age was 15.3 ± 8.4 years. Mean preoperative DFA in the right eye (RE was −3.9° and in the left eye (LE was −2.9°. Mean postoperative DFA in RE was 0.2° and in LE was 0.9°. The mean change in the DFA for RE was 4.1° ± 1.3° and for LE was 3.8° ± 1.2°. All the patients were aligned horizontally within 6 prism diopter and no pattern and no diplopia postoperatively. The A pattern was corrected in all the patient postsurgery. For each mm of surgery, an improvement of 0.8° was seen in the DFA. Conclusion: We report the effect of SOSL on torsion. The SOSL reduces intorsion postsurgery and is, therefore, a valuable procedure in SOOA where both pattern and in torsion needs to be corrected.

  10. Crustal Rock: Recorder of Oblique Impactor Meteoroid Trajectories

    Science.gov (United States)

    Ahrens, Thomas J.

    2005-07-01

    Oblique impact experiments in which 2g lead bullets strike samples of San Marcos granite and Bedford limestone at 1.2 km/s induce zones of increased crack density (termed shocked damage) which result in local decreases in bulk and shear moduli that results in maximum decreases of 30-40% in compressional and shear wave velocity (Budianski and O'Connell). Initial computer simulation of oblique impacts of meteorites (Pierazzo and Melosh) demonstrate the congruence of peak shock stress trajectory with the pre-impact meteoroid trajectory. We measure (Ai and Ahrens) via multi-beam (˜ 300) tomographic inversion, the sub-impact surface distribution of damage from the decreases in compressional wave velocity in the 20 x 20 x 15 cm rock target. The damage profiles for oblique impacts are markedly asymmetric (in plane of pre-impact meteoroid pre-impact trajectory) beneath the nearly round excavated craters. Thus, meteorite trajectory information can be recorded in planetary surfaces. Asymmetric sub-surface seismic velocity profiles beneath the Manson (Iowa) and Ries (Germany) impact craters demonstrate that pre-impact meteoroid trajectories records remain accessible for at least ˜ 10 ^ 8 years.

  11. Titan's interior constrained from its obliquity and tidal Love number

    Science.gov (United States)

    Baland, Rose-Marie; Coyette, Alexis; Yseboodt, Marie; Beuthe, Mikael; Van Hoolst, Tim

    2016-04-01

    In the last few years, the Cassini-Huygens mission to the Saturn system has measured the shape, the obliquity, the static gravity field, and the tidally induced gravity field of Titan. The large values of the obliquity and of the k2 Love number both point to the existence of a global internal ocean below the icy crust. In order to constrain interior models of Titan, we combine the above-mentioned data as follows: (1) we build four-layer density profiles consistent with Titan's bulk properties; (2) we determine the corresponding internal flattening compatible with the observed gravity and topography; (3) we compute the obliquity and tidal Love number for each interior model; (4) we compare these predictions with the observations. Previously, we found that Titan is more differentiated than expected (assuming hydrostatic equilibrium), and that its ocean is dense and less than 100 km thick. Here, we revisit these conclusions using a more complete Cassini state model, including: (1) gravitational and pressure torques due to internal tidal deformations; (2) atmosphere/lakes-surface exchange of angular momentum; (3) inertial torque due to Poincaré flow. We also adopt faster methods to evaluate Love numbers (i.e. the membrane approach) in order to explore a larger parameter space.

  12. Oblique reconstruction of the cruciate ligaments on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Hidetoshi; Nishino, Koshi; Koga, Masayuki; Kitakata, Akira; Deya, Keizo; Nakagawa, Hiroto

    1984-12-01

    Optimal positioning where the entire longitudinal axis of the cruciate ligaments could be demonstrated on computed tomography was discovered by using an amputated knee and was applied clinically. To demonstrate the anterior cruciate ligament, the patient was positioned on the table with the hip flexed, abducted, externally rotated and knee flexed at a 110-140 degrees angle. For the posterior cruciate ligament, the patient was placed in a prone position on the table with the knee flexed at a 50 degrees angle. These positions, especially the one for the anterior cruciate ligament, were difficult for some patients with gonalgia or limited range of motion. Reconstruction in the oblique planes was studied for those patients by using an amputated knee and quasi-ligament made of gum. Clinically, an axial image was obtained by the simple position of the patient lying prone on the table with knee extended. Oblique reconstruction was made from the axial images and this reconstructed image also demonstrated the entire longitudinal axis of the ligament. The rupture of the cruciate ligaments could be assessed by the reconstructed image in the oblique plane. (author).

  13. Evaluation of chest injury mechanisms in nearside oblique frontal impacts.

    Science.gov (United States)

    Iraeus, Johan; Lindquist, Mats; Wistrand, Sofie; Sibgård, Elin; Pipkorn, Bengt

    2013-01-01

    Despite the use of seat belts and modern safety systems, many automobile occupants are still seriously injured or killed in car crashes. Common configurations in these crashes are oblique and small overlap frontal impacts that often lead to chest injuries.To evaluate the injury mechanism in these oblique impacts, an investigation was carried out using mathematical human body model simulations. A model of a simplified vehicle interior was developed and validated by means of mechanical sled tests with the Hybrid III dummy. The interior model was then combined with the human body model THUMS and validated by means of mechanical PMHS sled tests. Occupant kinematics as well as rib fracture patterns were predicted with reasonable accuracy.The final model was updated to conform to modern cars and a simulation matrix was run. In this matrix the boundary conditions, ΔV and PDOF, were varied and rib fracture risk as a function of the boundary conditions was evaluated using a statistical framework.In oblique frontal impacts, two injury producing mechanisms were found; (i) diagonal belt load and (ii) side structure impact. The second injury mechanism was found for PDOFs of 25°-35°, depending on ΔV. This means that for larger PDOFs, less ΔV is needed to cause a serious chest injury.

  14. Mending Milankovitch theory: obliquity amplification by surface feedbacks

    Directory of Open Access Journals (Sweden)

    C. R. Tabor

    2013-07-01

    Full Text Available Milankovitch theory states that orbitally induced changes in high-latitude summer insolation dictate the waxing and waning of ice-sheets. Accordingly, precession should dominate the ice-volume response because it most strongly modulates summer insolation intensity. However, Early Pleistocene (2.6–0.8 Ma ice-volume proxy records vary almost exclusively at the frequency of the obliquity cycle. To explore this paradox, we use an Earth system model coupled with a dynamic ice-sheet to separate the climate responses to idealized transient orbits of obliquity and precession that maximize insolation changes. Our results show that positive surface albedo feedbacks between high-latitude annual-mean insolation, ocean heat flux and sea-ice coverage, and boreal forest/tundra exchange enhance the ice-volume response to obliquity forcing relative to precession forcing. These surface feedbacks, in combination with modulation of the precession cycle power by eccentricity, may explain the dominantly 41 kyr cycles in global ice volume of the Early Pleistocene.

  15. Limited oblique corpectomy for treatment of ossified posterior longitudinal ligament

    Directory of Open Access Journals (Sweden)

    Goel A

    2005-01-01

    Full Text Available Objective: We present our experience with treating four cases with ossified posterior longitudinal ligaments (OPLL causing cervical cord compression by limited oblique and strategic corpectomy. Materials and results: Four patients with cervical OPLL were treated by the discussed technique during the period of October 2000 to January 2005. The ages of the patients ranged from 46 to 72 years. All patients presented with symptoms of progressively increasing myelopathy. Two patients had four level OPLL and two patients had two level OPLL. Surgery involved anterior cervical exposure and partial oblique corpectomy, which was essentially an extended midline and lateral undercutting of the body. The procedure provided a wide exposure for resection of the OPLL. No metal instrumentation or any other kind of fixation procedure was simultaneously carried out and there was no need for postoperative cervical immobilization. During the period of follow up that ranged from 6 month to 5 years (mean: 33 months all the four patients have shown sustained clinical improvement. Neuroimaging studies confirmed satisfactory anatomical cervical cord decompression in all patients. Conclusions: The technique of oblique and strategic corpectomy provided a wide exposure for resection of the OPLL and preserved the stability of the region.

  16. Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

    Science.gov (United States)

    Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N.

    2015-01-01

    The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (exercise, previous studies have reported paradoxical transfer function analysis (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20–30 yr; n = 10) and older (62–72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45–50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02–0.07 Hz) and low frequency (0.07–0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (−34%) in phase (−0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels. PMID:26586907

  17. Comparison on nausea & vomiting between supine and semi fowler position during hemodialysis

    Directory of Open Access Journals (Sweden)

    Azizollahshahreki

    2009-01-01

    Full Text Available (Received 23 Sep, 2008; Accepted 17 Jan, 2009AbstractBackground and purpose: The most common treatment used for end-stage renal disease (ESRD is hemodialysis. Although, this treatment caused may promote longevity, however, many complications may occur, such as nausea & vomiting. Body position during hemodialysis has an effect on nausea & vomiting episodes, patients who may lay in Semi fowler position during hemodialysis are able to communicate with circumstances comfortably, furthermore, with inner organ self arrangement into body in a semi-fowler position, the stomach discharges quickly. In this study, we assessed nausea & vomiting during hemodialysis, in two supine and semi fowler position.Materials and methods: In this quasi-experimental study, one group (pre -post test,45 patients under hemodialysis in Zabol City, were placed in two positions and in each position, which took two sessions, controlled indexes for nausea and vomiting within each half hour and if changes occurred, in that moment controlled appeared.Results: Nausea incidence, during hemodialysis did not have a significant difference within the two positions. Vilkaksons test showed significant difference (P<0/05 in frequency, duration and severity of nausea incidences in two positions, while these indexes in semi- fowler position were reduced. With Vilkaksion and Mac Nemar test, any significant difference between frequency, duration and severity of vomiting incidences did not exist.Conclusion: Regarding the finding that showed majority of nausea & vomiting indexes occurrences was similar in both positions, the other index was reduced in semi- fowler position. Furthermore, since this position has been more comfortable for patients, we would suggest using semi- fowler position with hemodialysis.J Mazand Univ Med Sci 2009; 19(68: 58-63 (Persian

  18. CT-measured regional specific volume change reflects regional ventilation in supine sheep.

    Science.gov (United States)

    Fuld, Matthew K; Easley, R Blaine; Saba, Osama I; Chon, Deokiee; Reinhardt, Joseph M; Hoffman, Eric A; Simon, Brett A

    2008-04-01

    Computer tomography (CT) imaging techniques permit the noninvasive measurement of regional lung function. Regional specific volume change (sVol), determined from the change in lung density over a tidal breath, should correlate with regional ventilation and regional lung expansion measured with other techniques. sVol was validated against xenon (Xe)-CT-specific ventilation (sV) in four anesthetized, intubated, mechanically ventilated sheep. Xe-CT used expiratory gated axial scanning during the washin and washout of 55% Xe. sVol was measured from the tidal changes in tissue density (H, houndsfield units) of lung regions using the relationship sVol = [1,000(Hi - He)]/[He(1,000 + Hi)], where He and Hi are expiratory and inspiratory regional density. Distinct anatomical markings were used to define corresponding lung regions of interest between inspiratory, expiratory, and Xe-CT images, with an average region of interest size of 1.6 +/- 0.7 ml. In addition, sVol was compared with regional volume changes measured directly from the positions of implanted metal markers in an additional animal. A linear relationship between sVol and sV was demonstrated over a wide range of regional sV found in the normal supine lung, with an overall correlation coefficient (R(2)) of 0.66. There was a tight correlation (R(2) = 0.97) between marker-measured volume changes and sVol. Regional sVol, which involves significantly reduced exposure to radiation and Xe gas compared with the Xe-CT method, represents a safe and efficient surrogate for measuring regional ventilation in experimental studies and patients.

  19. A comparative study of set up variations and bowel volumes in supine versus prone positions of patients treated with external beam radiation for carcinoma rectum

    Directory of Open Access Journals (Sweden)

    K R Rajeev

    2014-01-01

    Conclusion: The prone position using BB device was more effective in reducing irradiated SB volume in rectal cancer patients. There were no significant variations in the daily set up for patients treated in both supine and prone positions.

  20. Changes in the excitability of the H-reflex in wrist flexors related to the prone or supine position of the forearm in man.

    Science.gov (United States)

    Baldissera, F; Bellani, G; Cavallari, P; Lalli, S

    2000-12-08

    The effect of the forearm position, prone vs. supine, on the excitability of the H-reflex in flexor carpi radialis (FCR) muscle was tested in nine adult volunteers by comparing the recruitment profiles of the H and M waves. The H-reflex size, normalized to the maximal M response, was lower when the forearm was supine than when it was prone, with an average reduction of about 50% over most of the H-recruitment curve. In three wrist positions, intermediate between prone and supine, the amount of reflex attenuation was related to the prono-supination angle. Control experiments excluded that the changes in the H reflex excitability were due to displacements of the stimulating or recording electrodes.

  1. Supine Versus Prone Position During Percutaneous Nephrolithotomy: A Report from the Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study

    DEFF Research Database (Denmark)

    G. Vadivia, José; M. Scarpa, Roberto; Duvdevani, Mordechai

    2011-01-01

    To determine differences in patients' characteristics, operative time and procedures, and perioperative outcomes between prone and supine positioning in percutaneous nephrolithotomy (PCNL) using the Clinical Research Office of the Endourological Society (CROES) PCNL Global Study database....

  2. The Effect of Cervical Stabilizing Exercises in the Standing Position and the Supine Position on Deep Neck Muscle Strength and Endurance

    National Research Council Canada - National Science Library

    JINYEOL JEON; SUNGBUM JU; HYUNJA JEONG

    2012-01-01

    [Purpose] The purpose of this study was to clarify the effect of cervical stabilizing exercises in the standing position and the supine position on the strength and endurance of deep neck muscles (DNM). [Subjects...

  3. Surgical Results in Unilateral Superior Oblique Muscle Palsy

    Directory of Open Access Journals (Sweden)

    Aylin Tenlik

    2014-08-01

    Full Text Available Objectives: To evaluate the surgical treatments and results of the patients with superior oblique muscle palsy (SOMP. Materials and Methods: Clinical charts of the patients with unilateral SOMP who were operated in our clinic between 1999 and 2009 were evaluated retrospectively. Patients’ demographics, preoperative signs, surgical procedure, complications, and final results were recorded. Results: Thirty-seven patients were included in the study, [21 (59% male, 15 (41% female]. The mean age was 20.6 years at the time of operation. The mean time interval between diagnosis and operation was 7.3 years. Postoperative follow-up period was 2.04 (ranging 1-10 years. Diplopia was determined in seven (18.9% patients, and abnormal head position in 36 (97.3% patients. Only inferior oblique tenotomy with distal muscle resection was performed in 25 patients. In addition, five patients had recession of the contralateral inferior rectus muscle and two patients had recession of the ipsilateral superior rectus muscle additional to inferior oblique tenotomy. Abnormal head position was completely improved in all of the patients postoperatively. The preoperative average score of the inferior oblique muscle (IOM overaction was +3.3±0.8, and postoperative overaction was found in only two patients (+1.5. There was statistically significant difference between the two periods (p<0.001. The average score of the superior oblique muscle hypofunction was -2.18 preoperatively, and in only three patients, the score was found -1.0 postoperatively. Difference between the two periods was statistically significant (p<0.001. While the preoperative average vertical deviation was 22 PD in primary position, none of the patients had hyperdeviation postoperatively. Diplopia was resolved in all seven affected patients postoperatively. Contralateral IOM hyperfunction was the most common complication (13.5%. Adherence syndrome was seen in none of the patients. Conclusion: It was found

  4. Rupture of the Distal Biceps Tendon Combined with a Supinator Muscle Tear in a 51-Year-Old Woman: A Case Report

    OpenAIRE

    Samir Nayyar; Martin Quirno; Saqib Hasan; Leon Rybak; Meislin, Robert J.

    2011-01-01

    Distal biceps tendon rupture is a relatively uncommon occurrence in the general female population, and to our knowledge, has not been reported in association with a supinator muscle tear. We report a case of 51-year-old woman who experienced sharp pain in her forearm and elbow after lifting a heavy object. History and physical examination raised suspicion for a distal biceps tendon rupture. MRI imaging determined a combined distal biceps tendon tear with a supinator muscle tear with subsequen...

  5. Combined hyperextension and supination of the elbow joint induces lateral ligament lesions. An experimental study of the pathoanatomy and kinematics in elbow ligament injuries

    DEFF Research Database (Denmark)

    Tyrdal, Stein; Olsen, Bo Sanderhoff

    1998-01-01

    An epidemiological study suggested that the injury mechanism of 'handball goalie's elbow' may be hyperextension. The pathomechanics of hyperextension combined with supination was studied in ten macroscopically normal, male, cadaveric elbow joint specimens. The age of the donors was 28.8 years...... rupture of the lateral collateral ligament. The lesions indicate that combined hyperextension and supination represent a possible mechanism leading to 'handball goalie's elbow'....

  6. Changing the Production Pipeline - Use of Oblique Aerial Cameras for Mapping Purposes

    Science.gov (United States)

    Moe, K.; Toschi, I.; Poli, D.; Lago, F.; Schreiner, C.; Legat, K.; Remondino, F.

    2016-06-01

    This paper discusses the potential of current photogrammetric multi-head oblique cameras, such as UltraCam Osprey, to improve the efficiency of standard photogrammetric methods for surveying applications like inventory surveys and topographic mapping for public administrations or private customers. In 2015, Terra Messflug (TM), a subsidiary of Vermessung AVT ZT GmbH (Imst, Austria), has flown a number of urban areas in Austria, Czech Republic and Hungary with an UltraCam Osprey Prime multi-head camera system from Vexcel Imaging. In collaboration with FBK Trento (Italy), the data acquired at Imst (a small town in Tyrol, Austria) were analysed and processed to extract precise 3D topographic information. The Imst block comprises 780 images and covers an area of approx. 4.5 km by 1.5 km. Ground truth data is provided in the form of 6 GCPs and several check points surveyed with RTK GNSS. Besides, 3D building data obtained by photogrammetric stereo plotting from a 5 cm nadir flight and a LiDAR point cloud with 10 to 20 measurements per m² are available as reference data or for comparison. The photogrammetric workflow, from flight planning to Dense Image Matching (DIM) and 3D building extraction, is described together with the achieved accuracy. For each step, the differences and innovation with respect to standard photogrammetric procedures based on nadir images are shown, including high overlaps, improved vertical accuracy, and visibility of areas masked in the standard vertical views. Finally the advantages of using oblique images for inventory surveys are demonstrated.

  7. HIERARCHICAL REGULARIZATION OF POLYGONS FOR PHOTOGRAMMETRIC POINT CLOUDS OF OBLIQUE IMAGES

    Directory of Open Access Journals (Sweden)

    L. Xie

    2017-05-01

    Full Text Available Despite the success of multi-view stereo (MVS reconstruction from massive oblique images in city scale, only point clouds and triangulated meshes are available from existing MVS pipelines, which are topologically defect laden, free of semantical information and hard to edit and manipulate interactively in further applications. On the other hand, 2D polygons and polygonal models are still the industrial standard. However, extraction of the 2D polygons from MVS point clouds is still a non-trivial task, given the fact that the boundaries of the detected planes are zigzagged and regularities, such as parallel and orthogonal, cannot preserve. Aiming to solve these issues, this paper proposes a hierarchical polygon regularization method for the photogrammetric point clouds from existing MVS pipelines, which comprises of local and global levels. After boundary points extraction, e.g. using alpha shapes, the local level is used to consolidate the original points, by refining the orientation and position of the points using linear priors. The points are then grouped into local segments by forward searching. In the global level, regularities are enforced through a labeling process, which encourage the segments share the same label and the same label represents segments are parallel or orthogonal. This is formulated as Markov Random Field and solved efficiently. Preliminary results are made with point clouds from aerial oblique images and compared with two classical regularization methods, which have revealed that the proposed method are more powerful in abstracting a single building and is promising for further 3D polygonal model reconstruction and GIS applications.

  8. Hierarchical Regularization of Polygons for Photogrammetric Point Clouds of Oblique Images

    Science.gov (United States)

    Xie, L.; Hu, H.; Zhu, Q.; Wu, B.; Zhang, Y.

    2017-05-01

    Despite the success of multi-view stereo (MVS) reconstruction from massive oblique images in city scale, only point clouds and triangulated meshes are available from existing MVS pipelines, which are topologically defect laden, free of semantical information and hard to edit and manipulate interactively in further applications. On the other hand, 2D polygons and polygonal models are still the industrial standard. However, extraction of the 2D polygons from MVS point clouds is still a non-trivial task, given the fact that the boundaries of the detected planes are zigzagged and regularities, such as parallel and orthogonal, cannot preserve. Aiming to solve these issues, this paper proposes a hierarchical polygon regularization method for the photogrammetric point clouds from existing MVS pipelines, which comprises of local and global levels. After boundary points extraction, e.g. using alpha shapes, the local level is used to consolidate the original points, by refining the orientation and position of the points using linear priors. The points are then grouped into local segments by forward searching. In the global level, regularities are enforced through a labeling process, which encourage the segments share the same label and the same label represents segments are parallel or orthogonal. This is formulated as Markov Random Field and solved efficiently. Preliminary results are made with point clouds from aerial oblique images and compared with two classical regularization methods, which have revealed that the proposed method are more powerful in abstracting a single building and is promising for further 3D polygonal model reconstruction and GIS applications.

  9. Orientation of Oblique Airborne Image Sets - Experiences from the Isprs/eurosdr Benchmark on Multi-Platform Photogrammetry

    Science.gov (United States)

    Gerke, M.; Nex, F.; Remondino, F.; Jacobsen, K.; Kremer, J.; Karel, W.; Hu, H.; Ostrowski, W.

    2016-06-01

    During the last decade the use of airborne multi camera systems increased significantly. The development in digital camera technology allows mounting several mid- or small-format cameras efficiently onto one platform and thus enables image capture under different angles. Those oblique images turn out to be interesting for a number of applications since lateral parts of elevated objects, like buildings or trees, are visible. However, occlusion or illumination differences might challenge image processing. From an image orientation point of view those multi-camera systems bring the advantage of a better ray intersection geometry compared to nadir-only image blocks. On the other hand, varying scale, occlusion and atmospheric influences which are difficult to model impose problems to the image matching and bundle adjustment tasks. In order to understand current limitations of image orientation approaches and the influence of different parameters such as image overlap or GCP distribution, a commonly available dataset was released. The originally captured data comprises of a state-of-the-art image block with very high overlap, but in the first stage of the so-called ISPRS/EUROSDR benchmark on multi-platform photogrammetry only a reduced set of images was released. In this paper some first results obtained with this dataset are presented. They refer to different aspects like tie point matching across the viewing directions, influence of the oblique images onto the bundle adjustment, the role of image overlap and GCP distribution. As far as the tie point matching is concerned we observed that matching of overlapping images pointing to the same cardinal direction, or between nadir and oblique views in general is quite successful. Due to the quite different perspective between images of different viewing directions the standard tie point matching, for instance based on interest points does not work well. How to address occlusion and ambiguities due to different views onto

  10. Area Estimation of Deep-Sea Surfaces from Oblique Still Images.

    Directory of Open Access Journals (Sweden)

    Frederico Carvalho Dias

    Full Text Available Estimating the area of seabed surfaces from pictures or videos is an important problem in seafloor surveys. This task is complex to achieve with moving platforms such as submersibles, towed or remotely operated vehicles (ROV, where the recording camera is typically not static and provides an oblique view of the seafloor. A new method for obtaining seabed surface area estimates is presented here, using the classical set up of two laser devices fixed to the ROV frame projecting two parallel lines over the seabed. By combining lengths measured directly from the image containing the laser lines, the area of seabed surfaces is estimated, as well as the camera's distance to the seabed, pan and tilt angles. The only parameters required are the distance between the parallel laser lines and the camera's horizontal and vertical angles of view. The method was validated with a controlled in situ experiment using a deep-sea ROV, yielding an area estimate error of 1.5%. Further applications and generalizations of the method are discussed, with emphasis on deep-sea applications.

  11. Quantification of intra-fraction motion in breast radiotherapy using supine magnetic resonance imaging

    Science.gov (United States)

    van Heijst, Tristan C. F.; Philippens, Mariëlle E. P.; Charaghvandi, Ramona K.; den Hartogh, Mariska D.; Lagendijk, Jan J. W.; Desirée van den Bongard, H. J. G.; van Asselen, Bram

    2016-02-01

    In early-stage breast-cancer patients, accelerated partial-breast irradiation techniques (APBI) and hypofractionation are increasingly implemented after breast-conserving surgery (BCS). For a safe and effective radiation therapy (RT), the influence of intra-fraction motion during dose delivery becomes more important as associated fraction durations increase and targets become smaller. Current image-guidance techniques are insufficient to characterize local target movement in high temporal and spatial resolution for extended durations. Magnetic resonance imaging (MRI) can provide high soft-tissue contrast, allow fast imaging, and acquire images during longer periods. The goal of this study was to quantify intra-fraction motion using MRI scans from 21 breast-cancer patients, before and after BCS, in supine RT position, on two time scales. High-temporal 2-dimensional (2D) MRI scans (cine-MRI), acquired every 0.3 s during 2 min, and three 3D MRI scans, acquired over 20 min, were performed. The tumor (bed) and whole breast were delineated on 3D scans and delineations were transferred to the cine-MRI series. Consecutive scans were rigidly registered and delineations were transformed accordingly. Motion in sub-second time-scale (derived from cine-MRI) was generally regular and limited to a median of 2 mm. Infrequently, large deviations were observed, induced by deep inspiration, but these were temporary. Movement on multi-minute scale (derived from 3D MRI) varied more, although medians were restricted to 2.2 mm or lower. Large whole-body displacements (up to 14 mm over 19 min) were sparsely observed. The impact of motion on standard RT techniques is likely small. However, in novel hypofractionated APBI techniques, whole-body shifts may affect adequate RT delivery, given the increasing fraction durations and smaller targets. Motion management may thus be required. For this, on-line MRI guidance could be provided by a hybrid MRI/RT modality, such as the

  12. Assessment of Speckle-Tracking Echocardiography-Derived Global Deformation Parameters During Supine Exercise in Children.

    Science.gov (United States)

    Liu, Michael Y; Tacy, Theresa; Chin, Clifford; Obayashi, Derek Y; Punn, Rajesh

    2016-03-01

    Exercise echocardiography is an underutilized tool in pediatrics with current applications including detecting segmental wall abnormalities, assessing the utility of global ventricular function, and measuring pulmonary hemodynamics. No prior study has applied speckle-tracking echocardiography (STE) during exercise echocardiography in children. The aim of this study was to determine the feasibility of measuring speckle-tracking-derived peak systolic velocities, global longitudinal and circumferential strain, and global strain rates at various phases of exercise. Ninety-seven healthy children underwent cardiopulmonary exercise testing using supine cycle ergometry. The exercise stress test consisted of baseline pulmonary function testing, monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturations while subjects pedaled against a ramp protocol based on body weight. Echocardiographic measurements and specifically speckle-tracking analysis were performed during exercise at baseline, at a heart rate of 160 beats per minute and at 10 min after exercise. Peak systolic velocity, peak systolic strain, and peak systolic strain rate at these three phases were compared in the subjects in which all measurements were accurately obtained. We were able to complete peak velocity, strain, and strain rate measurements in all three exercise phases for 36 out of the 97 subjects tested. There was no significant difference between the feasibility of measuring circumferential versus longitudinal strain (p = 0.25, B-corrected = 0.75). In the 36 subjects studied, the magnitude of circumferential strain values decreased from -18.3 ± 4.8 to -13.7 ± 4.0 % from baseline to HR 160 (p rates increased from baseline to HR 160, but neither decreased to baseline levels after 10 min of recovery, which correlated with heart rate variations with exercise. We studied the effects of frame rate on deformation measurements and we observed no difference

  13. Weak approximation of obliquely reflected diffusions in time-dependent domains

    OpenAIRE

    Önskog, Thomas; Nyström, Kaj

    2010-01-01

    In an earlier paper, we proved the existence of solutions to the Skorohod problem with oblique reflection in time-dependent domains and, subsequently, applied this result to the problem of constructing solutions, in time-dependent domains, to stochastic differential equations with oblique reflection. In this paper we use these results to construct weak approximations of solutions to stochastic differential equations with oblique reflection, in time-dependent domains in R^d, by means of a proj...

  14. Surgical treatment of superior oblique palsy: Predictors of outcome

    Directory of Open Access Journals (Sweden)

    Pilar Merino Sanz

    2017-01-01

    Full Text Available Purpose: The purpose of this study was to evaluate the incidence and outcome of surgically treated superior oblique palsy (SOP and the factors involved in its resolution. Methods: We performed a retrospective study of 76 patients who underwent surgery for SOP. We recorded data from the physical examination and the number and type of procedures performed. Favorable outcome was defined as resolution of or improvement in torticollis (≤5° and diplopia in primary position (PP and downgaze or as vertical deviation (VD <5 prism diopters (pd in PP and 10 pd in the oblique diagnostic position. Results: Mean age was 33.12 years. Congenital SOP was the most frequent type (65.8%. Mean preoperative VD was 15.89 ± 9.94 pd, decreasing to 3.07 ± 4.36 pd after surgery. Associated horizontal deviation was recorded in 51.32% of cases. The mean number of procedures was 1.37 ± 0.62 (range 1–4, with 69.7% of patients requiring only one procedure. The mean number of muscles operated on was 1.96 ± 1.01 (inferior oblique being the most frequent. A greater reduction in VD after surgery was observed in patients with congenital SOP (P = 0.04. Although none of the factors evaluated influenced surgical outcome, amblyopic patients had a greater risk of reoperation (P = 0.04. A favorable outcome was achieved in 75% of cases. Mean follow-up was 37.08 months. Conclusion: Congenital SOP was twice as frequent as acquired SOP and although surgery was successful in most cases, a greater reduction in VD was obtained in congenital cases. Amblyopia was identified as a risk factor for reoperation.

  15. Scattering of Plane Guided Waves Obliquely Incident on Straight Features

    Science.gov (United States)

    Wilcox, P. D.; Velichko, A.; Drinkwater, B. W.; Croxford, A. J.; Todd, M. D.

    2011-06-01

    A semi-analytical finite element model is developed to study the scattering of plane guided waves obliquely incident on a straight geometric feature. The model is first used to investigate the reflection of the S0 mode from a free edge and the results are compared to those of bulk waves reflecting from a free boundary. The model is then used to predict the transmission of the S0 mode past an adhesively-bonded stiffener. The results obtained are in excellent agreement with experimental measurements.

  16. Optical design of the oblique Ece antenna system for JET

    Energy Technology Data Exchange (ETDEWEB)

    Sozzi, C. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy)]. E-mail: sozzi@ifp.cnr.it; Bruschi, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); Simonetto, A. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Milan (Italy); DeLaLuna, E. [Asociacion EURATOM-CIEMAT, CIEMAT, Madrid (Spain); Fessey, J. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom); Riccardo, V. [EURATOM-UKAEA Association, Culham Science Centre, Abingdon (United Kingdom)

    2005-11-15

    Systematic disagreements between Ece and Thomson Scattering diagnostics observed in various fusion devices led to the proposal of the so called Oblique Ece diagnostics on JET. This system will allow the study of the electron distribution function at low energies to reveal deviations from the Maxwellian distribution. This paper is devoted to the design of the quasi optical antenna for this diagnostics. The physical bases of the diagnostics imply two lines of sight at about 10{sup o} and 20{sup o} respectively from the magnetic field gradient. Severe geometrical constraints are imposed by the location of the antenna. The design strategy and physical optics calculations used to validate it are presented.

  17. Nonlinear evolution of oblique waves on compressible shear layers

    Science.gov (United States)

    Goldstein, M. E.; Leib, S. J.

    1989-01-01

    The effects of critical-layer nonlinearity on spatially growing oblique instability waves on compressible shear layers between two parallel streams are considered. The analysis shows that mean temperature nonuniformities cause nonlinearity to occur at much smaller amplitudes than it does when the flow is isothermal. The nonlinear instability wave growth rate effects are described by an integrodifferential equation which bears some resemblance to the Landau equation, in that it involves a cubic-type nonlinearity. The numerical solutions to this equation are worked out and discussed in some detail. Inviscid solutions always end in a singularity at a finite downstream distance, but viscosity can eliminate this singularity for certain parameter ranges.

  18. The Obliquity Distribution of Near-Earth Asteroids

    Science.gov (United States)

    Chesley, Steven R.; Farnocchia, D.; Cotto-Figueroa, D.; Statler, T. S.

    2013-05-01

    Abstract (2,250 Maximum Characters): Direct estimates of the Yarkovsky effect on near-Earth asteroids (NEAs) indicate that detectable semimajor axis drift rates are approximately 2-4 times more likely to be negative than positive (Nugent et al., AJ 144, 2012; Farnocchia et al., Icarus in press, 2013). The Yarkovsky effect induces a semimajor axis drift rate that is proportional to the cosine of the obliquity, and thus the excess of negative drift rates suggests an excess of retrograde rotation among the NEAs. This reinforces an earlier result from light curve inversion techniques (La Spina et al., Nature 428, 2004). The retrograde excess is presumed to arise from the nu6 resonance, which is situated near the inner edge of the main belt. Main-belt asteroids that are Yarkovsky-driven into the near-Earth region via the nu6 resonance must have a negative semimajor axis drift and therefore retrograde rotation, leading to an overabundance of retrograde rotators, even though other source regions may have parity between retrograde and direct rotators. The Yarkovsky detections do not directly shed light on the relative presence of mid-range obliquities, which tend to have low drift rates and therefore fail to yield statistically significant drift estimates, but they do present significantly different selection effects when compared to light curve inversions. We present preliminary results from our effort to derive independent constraints on the obliquity distribution of NEAs based on the distribution of estimated semimajor axis drift rates among the NEA population and their associated uncertainties. Our approach to solving the inverse problem starts by deriving the drift rates and associated signal-to-noise ratios for a semi-synthetic NEA population that assumes a parameterized obliquity distribution. The parameters are adjusted until the simulated distributions match the observed distributions, yielding not only an estimated distribution, but also uncertainties and

  19. Strain Partitioning and the Geometry of Oblique Plate Convergence

    Science.gov (United States)

    Guzman-Speziale, M.

    2004-05-01

    Strain partitioning occurs at convergent margins where oblique subduction takes place, a fact that has been known for a number of years. The geometry of plate subduction controls strain-partitioning mode in the forearc region. Deformation in the forearc depends on the direction of relative plate convergence, earthquake slip vectors, and trench-normal direction. Two basic angles are derived from these vectors: obliquity of plate convergence, the angle of plate motion direction and trench normal, and slip partitioning which is the angle between the earthquake slip vector and trench normal. Traditionally, oblique convergence models consider the trench (convergent margin) a straight line on a flat Earth. This is correct for small-scale (in the order of a few kilometers) models. However, earthquakes along convergent margins often have fault lengths of tens and even hundreds (for magnitude 7 or greater) of kilometers. On the other hand, the direction normal to the trench is usually calculated averaging contiguous points along the deepest part of the digitized bathymetry, yielding the local trend of the trench. The direction normal to the trench thus calculated varies greatly along a specific trench. In this work we propose an alternate treatment of the geometry of the trench. On a spherical Earth, trench segments form arcs of small circles. Usually, a trench of interest will contain a few (three-five) such segments, which can be fitted (in a least-squares sense) with small circles with a known center of curvature (or pole) on the surface of the Earth. Also known are the initial and final points. Instead of the standard direction normal to the trench, we use the average azimuth from the segment of small circle to its corresponding pole. We use this direction instead of trench normal and calculate obliquity of plate convergence. We test our model along the western Sunda arc, from the eastern Himalayan sintaxis to Sumatra. Five contiguos small circles were fitted to the

  20. FLOW CHARACTERISTICS OF TURBULENT JETS INJECTED OBLIQUELY IN CROSSFLOW

    Institute of Scientific and Technical Information of China (English)

    GUO Ting-ting; LI Shao-hua; XU Zhong

    2004-01-01

    Numerical simulation has been performed to investigate the characteristics of the turbulent jet issuing obliquely into a crossflow, at the injection angles of 90° and 60°. The SIMPLEC algorithm in the body-fitted coordinates and the wall-function method using the RNG k-ε turbulence model have been adopted to simulate this flow at two jet-to-crossflow velocity ratios, 2 and 4. The numerical results are good agreement with the experimental measurements, the jet trajectories have been given, the separation events in the lee of the jet exit have been found, and the forming mechanism has been analyzed.

  1. Computer modeling of test particle acceleration at oblique shocks

    Science.gov (United States)

    Decker, Robert B.

    1988-01-01

    The present evaluation of the basic techniques and illustrative results of charged particle-modeling numerical codes suitable for particle acceleration at oblique, fast-mode collisionless shocks emphasizes the treatment of ions as test particles, calculating particle dynamics through numerical integration along exact phase-space orbits. Attention is given to the acceleration of particles at planar, infinitessimally thin shocks, as well as to plasma simulations in which low-energy ions are injected and accelerated at quasi-perpendicular shocks with internal structure.

  2. Oblique corrections in the Dine-Fischler-Srednicki axion model

    Directory of Open Access Journals (Sweden)

    Katanaeva Alisa

    2016-01-01

    We discuss the Dine-Fischler-Srednicki (DFS model, which extends the two-Higgs doublet model with an additional Peccei-Quinn symmetry and leads to a physically acceptable axion. The non-linear parametrization of the DFS model is exploited in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale. We compute the oblique corrections and use their values from the electroweak experimental fits to put constraints on the mass spectrum of the DFS model.

  3. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact : Experimental Investigation II

    OpenAIRE

    S. N. Dikshit

    1999-01-01

    The ballistic behaviour of thick steel armour plate at different obliquities has been investigated. Ballistic experiments were conducted in the velocity range 300-800 mls at 0°, 15°, 30° and 45° obliquity .A steel, conical projectile or 6.1 mm diameter was impacted on a 10 mm thick steel armour plate. At 30° and 45° obliquity, the plate offers protection up to a striking velocity of 800 mls. At zero obliquity, the plate provides protection below 6~ m/s. The depth of penetration decreases with...

  4. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact: Experimental Investigation .

    OpenAIRE

    S. N. Dikshit

    1998-01-01

    The ballistic behaviour of thick steel amlOW- plate has been investigated at different obliquity when impacted by an ogive-shaped steel projectile. The ballistic experiments have been conducted in the velocity range 300-800 m/s. Both the thickness of the target plate and the diameter of the projectile were 20 Inm. At 30 and 45. obliquity 20 mm plate provides full protection at 800 m/s, whereas at 0 and 15. obliquity, the plate provides protection up to 600 m/s. At 15 and 30° obliquity, the pl...

  5. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact : Experimental Investigation II

    OpenAIRE

    S. N. Dikshit

    1999-01-01

    The ballistic behaviour of thick steel armour plate at different obliquities has been investigated. Ballistic experiments were conducted in the velocity range 300-800 mls at 0°, 15°, 30° and 45° obliquity .A steel, conical projectile or 6.1 mm diameter was impacted on a 10 mm thick steel armour plate. At 30° and 45° obliquity, the plate offers protection up to a striking velocity of 800 mls. At zero obliquity, the plate provides protection below 6~ m/s. The depth of penetration decreases with...

  6. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact: Experimental Investigation .

    OpenAIRE

    S. N. Dikshit

    1998-01-01

    The ballistic behaviour of thick steel amlOW- plate has been investigated at different obliquity when impacted by an ogive-shaped steel projectile. The ballistic experiments have been conducted in the velocity range 300-800 m/s. Both the thickness of the target plate and the diameter of the projectile were 20 Inm. At 30 and 45. obliquity 20 mm plate provides full protection at 800 m/s, whereas at 0 and 15. obliquity, the plate provides protection up to 600 m/s. At 15 and 30° obliquity, the pl...

  7. Comparison of the sagittal spine lordosis by supine computed tomography and upright conventional radiographs in patients with spinal trauma.

    Science.gov (United States)

    Bouaicha, Samy; Lamanna, Claudia; Jentzsch, Thorsten; Simmen, Hans-Peter; Werner, Clément M L

    2014-01-01

    Retrospective data analysis. Objective. To compare the sagittal lordosis of the lumbar spine by supine computed tomography (CT) and upright conventional radiographs. There is sparse data about position and modality dependent changes of radiographic measurements in the sagittal lumbar spine. The anatomical and functional Cobb angles of the thoracolumbar spine in 153 patients with spinal injury were measured by conventional upright sagittal radiographs and supine CT scans. Patients were assigned either to group A (n = 101), with radiologically confirmed vertebral fractures, or to group B (n = 52), without any osseous lesions. The interchangeability of the two imaging modalities was calculated using a ± 3° and 5° range of acceptance. Group A showed a mean intraindividual difference of -3.8° for both the anatomical and the functional Cobb angle. Only 25.7% and 27.7% of the 101 patients showed a difference within the tolerated ± 3° margin. Using the ± 5° limits, only 46 and 47 individuals fell within the acceptable range, respectively. In the patients in group B, the mean intraindividual difference was -2.1° for the anatomical and -1.5° for the functional Cobb angle. Of the 52 patients, only 14 and 13 patients, respectively demonstrated an intraindividual difference within ± 3°. With regard to a threshold of ± 5°, both the functional and anatomical values were within the defined margins in only 25 (48%) patients. The use of supine CT measurements as a baseline assessment of the sagittal lordosis of the injured thoracolumbar spine does not appear to be appropriate when upright conventional sagittal plane radiographs are used for follow-up measurements.

  8. Comparison of the Sagittal Spine Lordosis by Supine Computed Tomography and Upright Conventional Radiographs in Patients with Spinal Trauma

    Directory of Open Access Journals (Sweden)

    Samy Bouaicha

    2014-01-01

    Full Text Available Study Design. Retrospective data analysis. Objective. To compare the sagittal lordosis of the lumbar spine by supine computed tomography (CT and upright conventional radiographs. Summary of Background Data. There is sparse data about position and modality dependent changes of radiographic measurements in the sagittal lumbar spine. Methods. The anatomical and functional Cobb angles of the thoracolumbar spine in 153 patients with spinal injury were measured by conventional upright sagittal radiographs and supine CT scans. Patients were assigned either to group A (n=101, with radiologically confirmed vertebral fractures, or to group B (n=52, without any osseous lesions. The interchangeability of the two imaging modalities was calculated using a ±3° and 5° range of acceptance. Results. Group A showed a mean intraindividual difference of −3.8° for both the anatomical and the functional Cobb angle. Only 25.7% and 27.7% of the 101 patients showed a difference within the tolerated ±3° margin. Using the ±5° limits, only 46 and 47 individuals fell within the acceptable range, respectively. In the patients in group B, the mean intraindividual difference was −2.1° for the anatomical and −1.5° for the functional Cobb angle. Of the 52 patients, only 14 and 13 patients, respectively demonstrated an intraindividual difference within ±3°. With regard to a threshold of ±5°, both the functional and anatomical values were within the defined margins in only 25 (48% patients. Conclusion. The use of supine CT measurements as a baseline assessment of the sagittal lordosis of the injured thoracolumbar spine does not appear to be appropriate when upright conventional sagittal plane radiographs are used for follow-up measurements.

  9. Gastrocnemius Stretching Program: More Effective in Increasing Ankle/Rear-Foot Dorsiflexion When Subtalar Joint Positioned in Pronation Than in Supination.

    Science.gov (United States)

    Johanson, Marie A; Armstrong, Megan; Hopkins, Chris; Keen, Meghan L; Robinson, Michael; Stephenson, Scott

    2015-08-01

    Stretching exercises are commonly prescribed for patients and healthy individuals with limited extensibility of the gastrocnemius muscle. To determine if individuals demonstrate more dorsiflexion at the ankle/rear foot and less at the midfoot after a gastrocnemius-stretching program with the subtalar joint (STJ) positioned in supination compared with pronation. Randomized controlled trial. Biomechanical laboratory. 22 volunteers with current or recent history of lower-extremity cumulative trauma and gastrocnemius tightness (10 women and 4 men, mean age 28 y) randomly assigned to stretching groups with the STJ positioned in either pronation (n = 11) or supination (n = 11). 3-wk home gastrocnemius-stretching program using a template to place the subtalar joint in either a pronated or a supinated position. A 7-camera Vicon motion-analysis system measured ankle/ rear-foot dorsiflexion and midfoot dorsiflexion of all participants during stretching with the STJ positioned in both pronation and supination before and after the 3-wk gastrocnemius-stretching program. A 2-way mixed-model ANOVA revealed a significant interaction (P = .019). At posttest, the group who performed the 3-week stretching program with the STJ positioned in pronation demonstrated more increased ankle/rear-foot dorsiflexion when measured with the STJ in pronation than the group who performed the 3-wk stretching program with the STJ positioned in supination. No significant main effect of stretching group or interaction for dorsiflexion at the midfoot was detected (P = .755 and P = .820, respectively). After a 3-wk gastrocnemius-stretching program, when measuring dorsiflexion with the STJ positioned in supination, the participants who completed a 3-wk gastrocnemius stretching program with the STJ positioned in pronation showed more increased dorsiflexion at the ankle/rear foot than participants who completed the stretching program with the STJ positioned in supination.

  10. Obliquity and precession as pacemakers of Pleistocene deglaciations

    CERN Document Server

    Feng, Fabo

    2015-01-01

    The Milankovitch theory states that the orbital eccentricity, precession, and obliquity of the Earth influence our climate by modulating the summer insolation at high latitudes in the northern hemisphere. Despite considerable success of this theory in explaining climate change over the Pleistocene epoch (2.6 to 0.01 Myr ago), it is inconclusive with regard to which combination of orbital elements paced the 100 kyr glacial-interglacial cycles over the late Pleistocene. Here we explore the role of the orbital elements in pacing the Pleistocene deglaciations by modeling ice-volume variations in a Bayesian approach. When comparing models, this approach takes into account the uncertainties in the data as well as the different degrees of model complexity. We find that the Earth's obliquity (axial tilt) plays a dominant role in pacing the glacial cycles over the whole Pleistocene, while precession only becomes important in pacing major deglaciations after the transition of the dominant period from 41 kyr to 100 kyr ...

  11. Multistability inspired by the oblique, pennate architectures of skeletal muscle

    Science.gov (United States)

    Kidambi, Narayanan; Harne, Ryan L.; Wang, K. W.

    2017-04-01

    Skeletal muscle mechanics exhibit a range of noteworthy characteristics, providing great inspiration for the development of advanced structural and material systems. These characteristics arise from the synergies demonstrated between muscle's constituents across the various length scales. From the macroscale oblique orientation of muscle fibers to the microscale lattice spacing of sarcomeres, muscle takes advantage of geometries and multidimensionality for force generation or length change along a desired axis. Inspired by these behaviors, this research investigates how the incorporation of multidimensionality afforded by oblique, pennate architectures can uncover novel mechanics in structures exhibiting multistability. Experimental investigation of these mechanics is undertaken using specimens of molded silicone rubber with patterned voids, and results reveal tailorable mono-, bi-, and multi-stability under axial displacements by modulation of transverse confinement. If the specimen is considered as an architected material, these results show its ability to generate intriguing, non-monotonic shear stresses. The outcomes would foster the development of novel, advanced mechanical metamaterials that exploit pennation and multidimensionality.

  12. Epipolar Rectification with Minimum Perspective Distortion for Oblique Images

    Science.gov (United States)

    Liu, Jianchen; Guo, Bingxuan; Jiang, Wanshou; Gong, Weishu; Xiao, Xiongwu

    2016-01-01

    Epipolar rectification is of great importance for 3D modeling by using UAV (Unmanned Aerial Vehicle) images; however, the existing methods seldom consider the perspective distortion relative to surface planes. Therefore, an algorithm for the rectification of oblique images is proposed and implemented in detail. The basic principle is to minimize the rectified images’ perspective distortion relative to the reference planes. First, this minimization problem is formulated as a cost function that is constructed by the tangent value of angle deformation; second, it provides a great deal of flexibility on using different reference planes, such as roofs and the façades of buildings, to generate rectified images. Furthermore, a reasonable scale is acquired according to the dihedral angle between the rectified image plane and the original image plane. The low-quality regions of oblique images are cropped out according to the distortion size. Experimental results revealed that the proposed rectification method can result in improved matching precision (Semi-global dense matching). The matching precision is increased by about 30% for roofs and increased by just 1% for façades, while the façades are not parallel to the baseline. In another designed experiment, the selected façades are parallel to the baseline, the matching precision has a great improvement for façades, by an average of 22%. This fully proves our proposed algorithm that elimination of perspective distortion on rectified images can significantly improve the accuracy of dense matching. PMID:27827991

  13. Exterior Orientation Estimation of Oblique Aerial Imagery Using Vanishing Points

    Science.gov (United States)

    Verykokou, Styliani; Ioannidis, Charalabos

    2016-06-01

    In this paper, a methodology for the calculation of rough exterior orientation (EO) parameters of multiple large-scale overlapping oblique aerial images, in the case that GPS/INS information is not available (e.g., for old datasets), is presented. It consists of five main steps; (a) the determination of the overlapping image pairs and the single image in which four ground control points have to be measured; (b) the computation of the transformation parameters from every image to the coordinate reference system; (c) the rough estimation of the camera interior orientation parameters; (d) the estimation of the true horizon line and the nadir point of each image; (e) the calculation of the rough EO parameters of each image. A developed software suite implementing the proposed methodology is tested using a set of UAV multi-perspective oblique aerial images. Several tests are performed for the assessment of the errors and show that the estimated EO parameters can be used either as initial approximations for a bundle adjustment procedure or as rough georeferencing information for several applications, like 3D modelling, even by non-photogrammetrists, because of the minimal user intervention needed. Finally, comparisons with a commercial software are made, in terms of automation and correctness of the computed EO parameters.

  14. Oblique waves on a vertically sheared current are rotational

    CERN Document Server

    Ellingsen, Simen Å

    2015-01-01

    In the study of surface waves in the presence of a shear current, a useful and much studied model is that in which the shear flow has constant vorticity. Recently it was shown by Constantin [Eur. J. Mech. B/Fluids 30 (2011) 12-16] that a flow of constant vorticity can only permit waves travelling exactly upstream or downstream, but not at oblique angles to the current, and several proofs to the same effect have appeared thereafter. Physical waves cannot possibly adhere to such a restriction, however. We resolve the paradox by showing that an oblique plane wave propagating atop a current of constant vorticity according to the linearized Euler equation carries with it an undulating perturbation of the vorticity field, hence is not prohibited by the Constantin theorem since vorticity is not constant. The perturbation of the vorticity field is readily interpreted in a Lagrangian perspective as the wave motion gently shifting and twisting the vortex lines as the wave passes. In the special case of upstream or down...

  15. Orbital obliquities of transiting planets from starspot occultations

    CERN Document Server

    Southworth, John

    2016-01-01

    When a planet passes in front of a starspot during a transit of its host star, it causes a small upward blip in the light curve. Modelling the transit with the starspot allows the size, brightness and position of the spot to be measured. If the same spot can be observed in two different transits, it is possible to track the motion of the spot due to the rotation of the star. The rotation period and velocity of the star (Prot and Vsini) and the sky-projected orbital obliquity of the system (lambda) can then be determined. If one has three or more observations of the same spot, the true orbital obliquity (psi) can be measured. We are performing this analysis for a number of cool stars orbited by transiting planets. We present our results so far and compile a catalogue of lambda and psi measurements from spot crossing events. The method is particularly useful for cool stars, and is therefore complementary to studies of the Rossiter-McLaughlin effect, which perform better on hotter and faster-rotating stars.

  16. Magnetic and Electric Field Polarizations of Oblique Magnetospheric Chorus Waves

    Science.gov (United States)

    Verkhoglyadova, Olga; Tsurutani, Bruce T.; Lakhina, Gurbax S.

    2012-01-01

    A theory was developed to explain the properties of the chorus magnetic and electric field components in the case of an arbitrary propagation angle. The new theory shows that a whistler wave has circularly polarized magnetic fields for oblique propagation. This theoretical result is verified by GEOTAIL observations. The wave electric field polarization plane is not orthogonal to the wave vector, and in general is highly elliptically polarized. A special case of the whistler wave called the Gendrin mode is also discussed. This will help to construct a detailed and realistic picture of wave interaction with magnetosphere electrons. It is the purpose of this innovation to study the magnetic and electric polarization properties of chorus at all frequencies, and at all angles of propagation. Even though general expressions for electromagnetic wave polarization in anisotropic plasma are derived in many textbooks, to the knowledge of the innovators, a detailed analysis for oblique whistler wave mode is lacking. Knowledge of the polarization properties is critical for theoretical calculations of resonant wave-particle interactions.

  17. The oblique perspective: philosophical diagnostics of contemporary life sciences research.

    Science.gov (United States)

    Zwart, Hub

    2017-12-01

    This paper indicates how continental philosophy may contribute to a diagnostics of contemporary life sciences research, as part of a "diagnostics of the present" (envisioned by continental thinkers, from Hegel up to Foucault). First, I describe (as a "practicing" philosopher) various options for an oblique (or symptomatic) reading of emerging scientific discourse, bent on uncovering the basic "philosophemes" of science (i.e. the guiding ideas, the basic conceptions of nature, life and technology at work in contemporary life sciences research practices). Subsequently, I outline a number of radical transformations occurring both at the object-pole and at the subject-pole of the current knowledge relationship, namely the technification of the object and the anonymisation or collectivisation of the subject, under the sway of automation, ICT and big machines. Finally, I further elaborate the specificity of the oblique perspective with the help of Lacan's theorem of the four discourses. Philosophical reflections on contemporary life sciences concur neither with a Master's discourse (which aims to strengthen the legitimacy and credibility of canonical sources), nor with university discourse (which aims to establish professional expertise), nor with what Lacan refers to as hysterical discourse (which aims to challenge representatives of the power establishment), but rather with the discourse of the analyst, listening with evenly-poised attention to the scientific files in order to bring to the fore the cupido sciendi (i.e. the will to know, but also to optimise and to control) which both inspires and disrupts contemporary life sciences discourse.

  18. Strike-Slip Fault Patterns on Europa: Obliquity or Polar Wander?

    Science.gov (United States)

    Rhoden, Alyssa Rose; Hurford, Terry A.; Manga, Michael

    2011-01-01

    Variations in diurnal tidal stress due to Europa's eccentric orbit have been considered as the driver of strike-slip motion along pre-existing faults, but obliquity and physical libration have not been taken into account. The first objective of this work is to examine the effects of obliquity on the predicted global pattern of fault slip directions based on a tidal-tectonic formation model. Our second objective is to test the hypothesis that incorporating obliquity can reconcile theory and observations without requiring polar wander, which was previously invoked to explain the mismatch found between the slip directions of 192 faults on Europa and the global pattern predicted using the eccentricity-only model. We compute predictions for individual, observed faults at their current latitude, longitude, and azimuth with four different tidal models: eccentricity only, eccentricity plus obliquity, eccentricity plus physical libration, and a combination of all three effects. We then determine whether longitude migration, presumably due to non-synchronous rotation, is indicated in observed faults by repeating the comparisons with and without obliquity, this time also allowing longitude translation. We find that a tidal model including an obliquity of 1.2?, along with longitude migration, can predict the slip directions of all observed features in the survey. However, all but four faults can be fit with only 1? of obliquity so the value we find may represent the maximum departure from a lower time-averaged obliquity value. Adding physical libration to the obliquity model improves the accuracy of predictions at the current locations of the faults, but fails to predict the slip directions of six faults and requires additional degrees of freedom. The obliquity model with longitude migration is therefore our preferred model. Although the polar wander interpretation cannot be ruled out from these results alone, the obliquity model accounts for all observations with a value

  19. Effect of a neoprene sleeve on knee joint position sense during sitting open kinetic chain and supine closed kinetic chain tests.

    Science.gov (United States)

    Birmingham, T B; Kramer, J F; Inglis, J T; Mooney, C A; Murray, L J; Fowler, P J; Kirkley, S

    1998-01-01

    The primary objective of the present study was to compare the effect of a neoprene sleeve on knee joint position sense during a sitting open kinetic chain test and a supine closed kinetic chain test. Young (24 +/- 2 years old), healthy subjects (18 men and 18 women) performed knee joint angle replication tests during open kinetic chain knee extension (sitting) and closed kinetic chain leg press (supine with an axial load of 15% body weight) before and after application of a neoprene sleeve over the dominant knee. The improvement in ability to replicate joint angles after application of the sleeve (sleeve effect) was significantly less during the supine closed kinetic chain test (0.3 degree +/- 1.4 degrees) than during the sitting open kinetic chain test (1.2 degrees +/- 1.1 degrees). The sleeve effect was inversely related to subjects' performance without the sleeve during both the sitting open kinetic chain and supine closed kinetic chain tests, suggesting that some people may derive greater benefit from the sleeve than others. Although the sleeve effects were small, particularly during the supine closed kinetic chain test, 72% of subjects felt that the sleeve improved their overall test performance. Future research is needed to establish the functional relevance of the small sleeve effects observed and to identify the characteristics of people who might derive greatest benefit from sleeve use.

  20. Reliability of measuring the passive range of shoulder horizontal adduction using a smartphone in the supine versus the side-lying position.

    Science.gov (United States)

    Lim, Jin-Yong; Kim, Tae-Ho; Lee, Jung-Seok

    2015-10-01

    [Purpose] The purpose of this study was to compare the reliability of the measurement of the passive range of motion (PROM) of shoulder horizontal adduction (SHA) measurements using a smartphone for the assessment posterior shoulder tightness (PST) between the side-lying and supine test positions. [Subjects and Methods] Forty-seven subjects (mean ± age, 24.9 ± 3.5 years) without shoulder pathology were included in this study. Intra-rater and inter-rater reliabilities were determined using intraclass correlation coefficients. The SHA PROM of each subject's dominant shoulder was measured using a smartphone by two investigators in two positions: the standard supine position, and a side-lying position on the tested side. [Results] The intra-rater reliability of the supine measurements was fair to good (ICC3,1 = 0.72-0.89), and for the side-lying measurements was excellent (ICC3,1 = 0.95-0.97). The inter-rater reliability of the supine measurements was fair (ICC2,2 = 0.79) and for the side-lying measurements was excellent (ICC2,2 = 0.94). [Conclusion] These results suggest that for healthy subjects, measurements of SHA using smartphones in the side-lying position has superior intra-rater and inter-rater reliabilities compared to the standard supine position.

  1. Comparison of Organ Location, Morphology, and Rib Coverage of a Midsized Male in the Supine and Seated Positions

    Directory of Open Access Journals (Sweden)

    Ashley R. Hayes

    2013-01-01

    Full Text Available The location and morphology of abdominal organs due to postural changes have implications in the prediction of trauma via computational models. The purpose of this study is to use data from a multimodality image set to devise a method for examining changes in organ location, morphology, and rib coverage from the supine to seated postures. Medical images of a male volunteer (78.6±0.77 kg, 175 cm in three modalities (Computed Tomography, Magnetic Resonance Imaging (MRI, and Upright MRI were used. Through image segmentation and registration, an analysis between organs in each posture was conducted. For the organs analyzed (liver, spleen, and kidneys, location was found to vary between postures. Increases in rib coverage from the supine to seated posture were observed for the liver, with a 9.6% increase in a lateral projection and a 4.6% increase in a frontal projection. Rib coverage area was found to increase 11.7% for the spleen. Morphological changes in the organs were also observed. The liver expanded 7.8% cranially and compressed 3.4% and 5.2% in the anterior-posterior and medial-lateral directions, respectively. Similar trends were observed in the spleen and kidneys. These findings indicate that the posture of the subject has implications in computational human body model development.

  2. Accelerated cardiac MR stress perfusion with radial sampling after physical exercise with an MR-compatible supine bicycle ergometer.

    Science.gov (United States)

    Pflugi, Silvio; Roujol, Sébastien; Akçakaya, Mehmet; Kawaji, Keigo; Foppa, Murilo; Heydari, Bobby; Goddu, Beth; Kissinger, Kraig; Berg, Sophie; Manning, Warren J; Kozerke, Sebastian; Nezafat, Reza

    2015-08-01

    To evaluate the feasibility of accelerated cardiac MR (CMR) perfusion with radial sampling using nonlinear image reconstruction after exercise on an MR-compatible supine bike ergometer. Eight healthy subjects were scanned on two separate days using radial and Cartesian CMR perfusion sequences in rest and exercise stress perfusion. Four different methods (standard gridding, conjugate gradient SENSE [CG-SENSE], nonlinear inversion with joint estimation of coil-sensitivity profiles [NLINV] and compressed sensing with a total variation constraint [TV]) were compared for the reconstruction of radial data. Cartesian data were reconstructed using SENSE. All images were assessed by two blinded readers in terms of image quality and diagnostic value. CG-SENSE and NLINV were scored more favorably than TV (in both rest and stress perfusion cases, P  0.05). We have demonstrated the feasibility of accelerated CMR perfusion using radial sampling after physical exercise using a supine bicycle ergometer in healthy subjects. For reconstruction of undersampled radial perfusion, CG-SENSE and NLINV resulted in better image quality than standard gridding or TV reconstruction. Further technical improvements and clinical assessment are needed before using this approach in patients with suspected coronary artery disease. © 2014 Wiley Periodicals, Inc.

  3. Supine MRI for regional breast radiotherapy: imaging axillary lymph nodes before and after sentinel-node biopsy

    Science.gov (United States)

    van Heijst, Tristan C. F.; Eschbach-Zandbergen, Debora; Hoekstra, Nienke; van Asselen, Bram; Lagendijk, Jan J. W.; Verkooijen, Helena M.; Pijnappel, Ruud M.; de Waard, Stephanie N.; Witkamp, Arjen J.; van Dalen, Thijs; Desirée van den Bongard, H. J. G.; Philippens, Marielle E. P.

    2017-08-01

    Regional radiotherapy (RT) is increasingly used in breast cancer treatment. Conventionally, computed tomography (CT) is performed for RT planning. Lymph node (LN) target levels are delineated according to anatomical boundaries. Magnetic resonance imaging (MRI) could enable individual LN delineation. The purpose was to evaluate the applicability of MRI for LN detection in supine treatment position, before and after sentinel-node biopsy (SNB). Twenty-three female breast cancer patients (cTis-3N0M0) underwent 1.5 T MRI, before and after SNB, in addition to CT. Endurance for MRI was monitored. Axillary levels were delineated. LNs were identified and delineated on MRI from before and after SNB, and on CT, and compared by Wilcoxon signed-rank tests. LN locations and LN-based volumes were related to axillary delineations and associated volumes. Although postoperative effects were visible, LN numbers on postoperative MRI (median 26 LNs) were highly reproducible compared to preoperative MRI when adding excised sentinel nodes, and higher than on CT (median 11, p  <  0.001). LN-based volumes were considerably smaller than respective axillary levels. Supine MRI of LNs is feasible and reproducible before and after SNB. This may lead to more accurate RT target definition compared to CT, with potentially lower toxicity. With the MRI techniques described here, initiation of novel MRI-guided RT strategies aiming at individual LNs could be possible.

  4. Radionuclide ventriculographic responses to graded supine and upright exercise: critical role of the Frank-Starling mechanism at submaximal exercise.

    Science.gov (United States)

    Steingart, R M; Wexler, J; Slagle, S; Scheuer, J

    1984-06-01

    To assess the influence of work load and posture on the response to exercise, 25 patients with coronary artery disease (CAD) and 17 normal subjects underwent graded supine and upright exercise radionuclide ventriculography. In both groups, end-diastolic counts increased with supine exercise (p less than 0.001). The ejection fraction and peak systolic pressure-end-systolic volume relation increased in normal subjects (p less than 0.02), but not in patients with CAD. At upright rest, end-diastolic counts decreased in both groups (p less than 0.001) and then increased with exercise (p less than 0.001). The increase in end-diastolic counts was most pronounced on the transition from upright rest to the 150-kpm work load and resulted in a significant increase in stroke counts (p less than 0.05) for both patients with CAD and normal subjects, without a measurable change in the ejection fraction or the peak systolic pressure-end-systolic volume relation. Later in exercise, end-diastolic counts plateaued, and the ejection fraction and the peak systolic pressure, end-systolic volume relation increased only among normal subjects. Thus, low-level upright exercise is highly dependent on the Starling mechanism in both normal subjects and patients with CAD, with enhanced contractility apparent only during more vigorous exercise in normal subjects.

  5. Influence of heart rate in nonlinear HRV indices as a sampling rate effect evaluated on supine and standing

    Directory of Open Access Journals (Sweden)

    Juan Bolea

    2016-11-01

    Full Text Available The purpose of this study is to characterize and attenuate the influence of mean heart rate (HR on nonlinear heart rate variability (HRV indices (correlation dimension, sample and approximate entropy as a consequence of being the HR the intrinsic sampling rate of HRV signal. This influence can notably alter nonlinear HRV indices and lead to biased information regarding autonomic nervous system (ANS modulation.First, a simulation study was carried out to characterize the dependence of nonlinear HRV indices on HR assuming similar ANS modulation. Second, two HR-correction approaches were proposed: one based on regression formulas and another one based on interpolating RR time series. Finally, standard and HR-corrected HRV indices were studied in a body position change database.The simulation study showed the HR-dependence of non-linear indices as a sampling rate effect, as well as the ability of the proposed HR-corrections to attenuate mean HR influence. Analysis in a body position changes database shows that correlation dimension was reduced around 21% in median values in standing with respect to supine position (p < 0.05, concomitant with a 28% increase in mean HR (p < 0.05. After HR-correction, correlation dimension decreased around 18% in standing with respect to supine position, being the decrease still significant. Sample and approximate entropy showed similar trends.HR-corrected nonlinear HRV indices could represent an improvement in their applicability as markers of ANS modulation when mean HR changes.

  6. Aerial Photography and Imagery, Oblique, 2008 Aerial Oblique imagery for Iredell County, NC, Published in 2008, 1:2400 (1in=200ft) scale, Iredell County GIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Oblique dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Other information as of 2008. It is...

  7. Aerial Photography and Imagery, Oblique, Washburn County had oblique photography flight done in April of 2009. Pictometry was contracted for the project., Published in 2009, 1:4800 (1in=400ft) scale, Washburn County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Aerial Photography and Imagery, Oblique dataset current as of 2009. Washburn County had oblique photography flight done in April of 2009. Pictometry was contracted...

  8. Oblique abdominal muscle activity in standing and in sitting on hard and soft seats

    NARCIS (Netherlands)

    C.J. Snijders (Chris); M.P. Bakker (Martin); A. Vleeming (Andry); R. Stoeckart (Rob); H.J. Stam (Henk)

    1995-01-01

    textabstractThe activity of the oblique abdominal muscles was investigated with the trunk in unconstrained, symmetrical and static postures. Electromyographic recordings in six healthy subjects revealed that in all subjects the activity of both the internal and the external obliques is significantly

  9. Asteroseismic Determination of Obliquities of the Exoplanet Systems Kepler-50 and Kepler-65

    NARCIS (Netherlands)

    Chaplin, W.J.; Sanchis-Ojeda, R.; Campante, T.L.; Handberg, R.; Stello, D.; Winn, J.N.; Basu, S.; Christensen-Dalsgaard, J.; Davies, G.R.; Metcalfe, T.S.; Buchhave, L.A.; Fischer, D.A.; Bedding, T.R.; Cochran, W.D.; Elsworth, Y.; Gilliland, R.L.; Hekker, S.; Huber, D.; Isaacson, H.; Karoff, C.; Kawaler, S.D.; Kjeldsen, H.; Latham, D.W.; Lund, M.N.; Lundkvist, M.; Marcy, G.W.; Miglio, A.; Barclay, T.; Lissauer, J.J.

    2013-01-01

    Results on the obliquity of exoplanet host stars?the angle between the stellar spin axis and the planetary orbital axis?provide important diagnostic information for theories describing planetary formation. Here we present the first application of asteroseismology to the problem of stellar obliquity

  10. A numerical study on the oblique focus in MR-guided transcranial focused ultrasound

    Science.gov (United States)

    Hughes, Alec; Huang, Yuexi; Pulkkinen, Aki; Schwartz, Michael L.; Lozano, Andres M.; Hynynen, Kullervo

    2016-11-01

    Recent clinical data showing thermal lesions from treatments of essential tremor using MR-guided transcranial focused ultrasound shows that in many cases the focus is oblique to the main axis of the phased array. The potential for this obliquity to extend the focus into lateral regions of the brain has led to speculation as to the cause of the oblique focus, and whether it is possible to realign the focus. Numerical simulations were performed on clinical export data to analyze the causes of the oblique focus and determine methods for its correction. It was found that the focal obliquity could be replicated with the numerical simulations to within 23.2+/- {{13.6}\\circ} of the clinical cases. It was then found that a major cause of the focal obliquity was the presence of sidelobes, caused by an unequal deposition of power from the different transducer elements in the array at the focus. In addition, it was found that a 65% reduction in focal obliquity was possible using phase and amplitude corrections. Potential drawbacks include the higher levels of skull heating required when modifying the distribution of power among the transducer elements, and the difficulty at present in obtaining ideal phase corrections from CT information alone. These techniques for the reduction of focal obliquity can be applied to other applications of transcranial focused ultrasound involving lower total energy deposition, such as blood-brain barrier opening, where the issue of skull heating is minimal.

  11. Oblique abdominal muscle activity in standing and in sitting on hard and soft seats

    NARCIS (Netherlands)

    C.J. Snijders (Chris); M.P. Bakker (Martin); A. Vleeming (Andry); R. Stoeckart (Rob); H.J. Stam (Henk)

    1995-01-01

    textabstractThe activity of the oblique abdominal muscles was investigated with the trunk in unconstrained, symmetrical and static postures. Electromyographic recordings in six healthy subjects revealed that in all subjects the activity of both the internal and the external obliques is significantly

  12. View relations

    DEFF Research Database (Denmark)

    Knudsen, Søren; Carpendale, Sheelagh

    2016-01-01

    In this paper, we explore the potential of using visual representations to support people in managing, organizing, and understanding relations between multiple visualization views. Multiple views can help people understand different facets of data and data processing, and are a crucial part of data...... analysis particularly when it is done collaboratively. Both the growing use of multiple views and the increasing display sizes have amplified the need to explore how to better help people to understand the relations between many views. To improve our understanding of how to visualize view relations, we...... invited visualization and interaction designers to critique and sketch representations of view relations. The participants provided design critiques, and sketched their own relation representations. Our findings expand the range and palette of ways of visually linking visualization views and suggest new...

  13. Influences of deposition strategies and oblique angle on properties of AISI316L stainless steel oblique thin-walled part by direct laser fabrication

    Science.gov (United States)

    Wang, Xinlin; Deng, Dewei; Qi, Meng; Zhang, Hongchao

    2016-06-01

    Direct laser fabrication (DLF) developed from laser cladding and rapid prototyping technique has been widely used to fabricate thin-walled parts exhibiting more functions without expending weight and size. Oblique thin-walled parts accompanied with inhomogeneous mechanical properties are common in application. In the present study, a series of AISI316L stainless steel oblique thin-walled parts are successfully produced by DLF, in addition, deposition strategies, microstructure, and mechanical property of the oblique thin-walled parts are investigated. The results show that parallel deposition way is more valuable to fabricate oblique thin-walled part than oblique deposition way, because of the more remarkable properties. The hardness of high side initially increases until the distance to the substrate reaches about 25 mm, and then decreases with the increase of the deposition height. Oblique angle has a positive effect on the tensile property but a negative effect on microstructure, hardness and elongation due to the more tempering time. The maximum average ultimate tensile strength (UTS) and elongation are presented 744.3 MPa and 13.5% when the angle between tensile loading direction and horizontal direction is 45° and 90°, respectively.

  14. Effect of oblique impact on impact strength of planetesimals

    Science.gov (United States)

    Yasui, Minami; Yoshida, Yusaku; Matsue, Kazuma; Takano, Shota; Arakawa, Masahiko; Ogawa, Kazunori; Okamoto, Chisato

    2016-10-01

    Collisional processes among planetesimals have played an important role for the formation and the evolution of the bodies in the solar system. Some researchers conducted impact experiments to examine the effects of target material, impact velocity, etc., on the impact strength. Planetesimals could collide with each other at various impact angles. Therefore, the effect of impact angle on the impact strength should be examined, but there are only a few studies about oblique impact experiments. In this study, we conducted oblique impact experiments of porous gypsum and glass spheres simulating planetesimals and examined the effect of the impact angle on the impact strength.We used a porous gypsum sphere and a glass sphere as a target. We carried out impact experiments by using two-stage H2 gas gun at Kobe University. A polycarbonate spherical projectile was accelerated at 2 to 7 km/s. The impact angle, θ, changed from 10° to 90° (90° at a head-on impact). The impact phenomena were observed by a high-speed camera to measure the fragment velocities.The impact strength Q* is defined as an energy density Q, which is the kinetic energy of impactor normalized by the target mass, when the largest fragment mass is half of the original target mass. In both cases of porous gypsum and glass targets, the Q* became larger as the θ decreased. We reanalyzed our results by using the effective energy density, Qc*, defined as Qsin2θ and we found that the results of oblique impacts matched with those of a head-on impact. Furthermore, the relationship between the Qc and the normalized largest fragment mass, ml/Mt, could be fitted by ml/Mt=A×Qc-p and the parameters, A and p, were 82.2 and 0.72 for a porous gypsum target and 1.1×106 and 2.12 for a glass target, respectively. We defined the impact strength Qc* by using the Qc, and the Qc* was about 1000 J/kg for both targets. The power p for a glass target was about 3 times larger than that for a porous gypsum target. This means

  15. RUPTURE OF THIN METAL TUBES BY NORMAL AND OBLIQUE IMPACT OF BLUNT CONICALNOSED MISSILES: EXPERIMENTS

    Institute of Scientific and Technical Information of China (English)

    Mu Jianchun; Zhang Tieguang

    2000-01-01

    Impact tests at both normal and oblique angles of incidence were .conducted on thin mild tubes using a moderate size of 90° conical-nosed missiles. Tne minimum impact speed that generated cracks through the thickness of the wall, termed the speed for rupture, was measured, and various modes of rupture were identified. For a thin tube hit by a missile at a normal angle of obliquity at the speed for rupture, the contact region spreads across the nose of the missile, and the transverse shear deformation is predominant in the final failure process. If the angle of obliquity is 30°, the missile pierces a hole through the wall of the tube. At the speed for rupture, the kinetic energy of the missile for oblique angle 30° is only about 45 % that required for plugging at a normal angle of obliquity.

  16. Penetration of sandwich plates with hybrid-cores under oblique ballistic impact

    Directory of Open Access Journals (Sweden)

    Changye Ni

    2014-01-01

    Full Text Available The oblique penetration performance of lightweight hybrid-cored sandwich plates are investigated numerically. To compose the hybrid-core, ceramic prisms are inserted into pyramidal metal lattice trusses and fixed using epoxy resin. Three-dimensional finite element simulations are carried out for the hybridcored sandwich impacted at 15°, 30°, 45°, and 60° obliquity by a hemispherical projectile. The ballistic limit, the energy absorbed by the constituting elements, and the critical oblique angle are quantified. The physical mechanisms underlying the failure and the influence of fundamental system parameters are explored. The angle of obliquity is found to have significant influence on the ballistic trajectory and erosion of the projectile, thus it is important for the impact response and penetration resistance of the sandwich. For oblique angles equal to or larger than 45°, the projectile moves mainly horizontally and can not effectively penetrate across the sandwich.

  17. Slice-based supine to standing postured deformation for Chinese anatomical models and the dosimetric results by wide band frequency electromagnetic field exposure: morphing.

    Science.gov (United States)

    Wu, Tongning; Tan, Liwen; Shao, Qing; Li, Ying; Yang, Lei; Zhao, Chen; Xie, Yi; Zhang, Shaoxiang

    2013-04-01

    Digital human models are frequently obtained from supine-postured medical images or cadaver slices, but many applications require standing models. This paper presents the work of reconstructing standing Chinese adult anatomical models from supine postured slices. Apart from the previous studies, the deformation works on 2-D segmented slices. The surface profile of the standing posture is adjusted by population measurement data. A non-uniform texture amplification approach is applied on the 2-D slices to recover the skin contour and to redistribute the internal tissues. Internal organ shift due to postures is taken into account. The feet are modified by matrix rotation. Then, the supine and standing models are utilised for the evaluation of electromagnetic field exposure over wide band frequency and different incident directions.

  18. [Contribution of the biceps brachii and pronator teres muscles to the efforts of pronation or supination. II. dynamic work (author's transl)].

    Science.gov (United States)

    van Hoecke, J; Pérot, C; Goubel, F

    1978-03-20

    The electrical activity of the biceps brachii and pronator teres muscles is studied through the prono-supination of the forearm in some anisometrical conditions (dynamic work) when the inertia of the mobile system and the elbow position are being varied. The subjects are required to perform pronation, supination and flexion movements, either isolated or combined. From the findings obtained when the integrated electrical activity (Q) is related to the mechanical work (W), one can conclude that a. the Q-W linear relationship seems to characterize the chief function of a muscle, b. the slope of the Q-W relationship depends on the elbow position, c. the pronator muscles do not inhibit in a selective manner the biceps supinating function. So a bifunctional muscle seems to act as a whole.

  19. Oblique solitary waves in a five component plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sijo, S.; Manesh, M.; Sreekala, G.; Venugopal, C., E-mail: cvgmgphys@yahoo.co.in [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, 686 560 Kerala (India); Neethu, T. W. [Department of Physics, CMS College, Mahatma Gandhi University, Kottayam, 686 001 Kerala (India); Renuka, G. [Kerala State Council for Science, Technology and Environment, Thiruvananthapuram, 695 004 Kerala (India)

    2015-12-15

    We investigate the influence of a second electron component on oblique dust ion acoustic solitary waves in a five component plasma consisting of positively and negatively charged dust, hydrogen ions, and hotter and colder electrons. Of these, the heavier dust and colder photo-electrons are of cometary origin while the other two are of solar origin; electron components are described by kappa distributions. The K-dV equation is derived, and different attributes of the soliton such as amplitude and width are plotted for parameters relevant to comet Halley. We find that the second electron component has a profound influence on the solitary wave, decreasing both its amplitude and width. The normalized hydrogen density strongly influences the solitary wave by decreasing its width; the amplitude of the solitary wave, however, increases with increasing solar electron temperatures.

  20. Titan's Obliquity as evidence for a subsurface ocean?

    CERN Document Server

    Baland, Rose-Marie; Yseboodt, Marie; Karatekin, Ozgur

    2011-01-01

    On the basis of gravity and radar observations with the Cassini spacecraft, the moment of inertia of Titan and the orientation of Titan's rotation axis have been estimated in recent studies. According to the observed orientation, Titan is close to the Cassini state. However, the observed obliquity is inconsistent with the estimate of the moment of inertia for an entirely solid Titan occupying the Cassini state. We propose a new Cassini state model for Titan in which we assume the presence of a liquid water ocean beneath an ice shell and consider the gravitational and pressure torques arising between the different layers of the satellite. With the new model, we find a closer agreement between the moment of inertia and the rotation state than for the solid case, strengthening the possibility that Titan has a subsurface ocean.

  1. Horizontal effect of the surgical weakening of the oblique muscles

    Directory of Open Access Journals (Sweden)

    Carlos Souza-Dias

    2011-06-01

    Full Text Available PURPOSE: To evaluate the influence of the oblique muscles surgical weakening on the horizontal alignment in the primary position (PP and its efficacy on the correction of the "A" and "V" anisotropies. METHODS: In order to study the influence of bilateral superior oblique muscles (SO weakening on the horizontal alignment in PP, we analyzed the files of 12 patients who underwent only that operation; no other muscle was operated on. We took the opportunity of those 12 patients to analyze the effect of their operation on the correction of "A" incomitance. For evaluating the effect of the inferior oblique muscles (IO weakening on the correction of the "V" pattern, we analyzed retrospectively the files of 67 anisotropic patients who underwent a bilateral SO weakening. In 10 of them, the only operation was the oblique muscles weakening and, in 57 patients, the horizontal recti were also operated on for the horizontal deviations in primary position. These patients were divided into two groups: 50 were esotropic and 17 exotropic. There was not any mixed anisotropy. RESULTS: The mean value of the preoperative "V" incomitance of the 50 esotropic patients was 24.25∆ ± 10.15∆; the mean postoperative correction was 15.56 ∆ ± 8.74∆. The mean correction between the PP and upgaze was 7.52∆ ± 7.47∆ and from the PP to downgaze was 8.56∆ ± 9.21∆. The same values of the 17 exotropic patients was: preoperative 31.88∆ ± 9.4∆; primary position to upgaze was 13.11∆ ± 4.9∆ and primary position to downgaze 14.11∆ ± 12.48∆. The mean preoperative value of the "A" incomitance among the 12 patients who underwent isolated SO weakening was 30.50∆ ± 19.25∆ and the postoperative was of 9,92∆, therefore a mean correction of 22.58∆ ± 17.54∆. Among these ones, in 5 there was no alteration of the deviation in primary position, in 4 there was an exo-effect and in 3 there was an eso-effect. The mean alteration of the deviation in PP was an

  2. Nonlinear evolution of oblique whistler waves in radiation belts

    Science.gov (United States)

    Sharma, R. P.; Nandal, P.; Yadav, N.; Sharma, Swati

    2017-02-01

    Magnetic power spectrum and formation of coherent structures have been investigated in the present work applicable to Van Allen radiation belt. The nonlinear interaction of high frequency oblique whistler wave and low frequency magnetosonic wave has been investigated. Simulation was performed of the coupled equation of these two waves. The nonlinear interaction of these waves leads to the formation of the localized structures. These resulting localized structures are of complex nature. The associated magnetic power spectrum has also been studied. Dispersive nonlinear processes account for the high frequency part of the spectrum. The resulting magnetic power spectrum shows a scaling of k^{ - 4.5}. The energy transfer process from injection scales to smaller scales is explained by the results.

  3. Sensitivity analysis for oblique incidence reflectometry using Monte Carlo simulations

    DEFF Research Database (Denmark)

    Kamran, Faisal; Andersen, Peter E.

    2015-01-01

    Oblique incidence reflectometry has developed into an effective, noncontact, and noninvasive measurement technology for the quantification of both the reduced scattering and absorption coefficients of a sample. The optical properties are deduced by analyzing only the shape of the reflectance...... profiles. This article presents a sensitivity analysis of the technique in turbid media. Monte Carlo simulations are used to investigate the technique and its potential to distinguish the small changes between different levels of scattering. We present various regions of the dynamic range of optical...... properties in which system demands vary to be able to detect subtle changes in the structure of the medium, translated as measured optical properties. Effects of variation in anisotropy are discussed and results presented. Finally, experimental data of milk products with different fat content are considered...

  4. Oblique septal crossbar graft for anterior septal angle reconstruction.

    Science.gov (United States)

    Aziz, Zeeshan S; Brenner, Michael J; Putman, Harrison C

    2010-01-01

    Nasal septal deformity is a central feature of the crooked nose, contributing to functional and aesthetic problems. Straightening of the septum often requires resection, scoring, or incision of the septum--maneuvers that inevitably weaken the cartilaginous dorsal and caudal L-shaped struts, which together are known as the L-strut. Compromise of this L-strut predisposes to septal buckling, recurrent deviation, and saddle nose deformity. We describe our experience with the oblique septal crossbar, a structural graft that allows biomechanically sound anterior septal angle reconstruction during septorhinoplasty. The technique improves dorsal septal support and facilitates correction of the crooked nose. The open septorhinoplasty approach and swinging door maneuver are followed by placement of a diagonally oriented crossbar graft, obtained from cartilage or the perpendicular plate. The approach allows consistent midline correction and buttressing of the nasal dorsum, with no complications to date.

  5. Oblique aerial images and their use in cultural heritage documentation

    DEFF Research Database (Denmark)

    Höhle, Joachim

    2013-01-01

    on automatically derived point clouds of high density. Each point will be supplemented with colour and other attributes. The problems experienced in these processes and the solutions to these problems are presented. The applied tools are a combination of professional tools, free software, and of own software...... developments. Special attention is given to the quality of input images. Investigations are carried out on edges in the images. The combination of oblique and nadir images enables new possibilities in the processing. The use of the near-infrared channel besides the red, green, and blue channel of the applied...... multispectral imagery is also of advantage. Vegetation close to the object of interest can easily be removed. A second example describes the modelling of a monument by means of a non-metric camera and a standard software package. The presented results regard achieved geometric accuracy and image quality...

  6. Emulating Nonreciprocity with Spatially Dispersive Metasurfaces Excited at Oblique Incidence

    Science.gov (United States)

    Pfeiffer, Carl; Grbic, Anthony

    2016-08-01

    Ultrathin metasurfaces supporting transverse surface currents provide extreme electromagnetic wave front and polarization control. Here, it is shown that adding longitudinal (normal) surface currents significantly expands the scope of electromagnetic phenomena that can be engineered with reciprocal materials. In particular, these metasurfaces are inherently spatially dispersive, which allows them to emulate nonreciprocal phenomena. It is analytically shown that spatially dispersive metasurfaces are effectively self-biased by the transverse momentum of the incident wave front. Long-standing notions of what makes a metasurface reciprocal are reinvestigated, and generalized reciprocity relations are derived. Several metasurfaces are designed that imitate Faraday rotation and optical isolation when illuminated with obliquely incident plane waves and normally incident vortex beams. These new surfaces break the inherent symmetry of previous metasurface designs, enabling low-profile devices with unprecedented functionality.

  7. Kramers-Kronig analysis of reflectance measured at oblique incidence.

    Science.gov (United States)

    Berreman, D W

    1967-09-01

    Kramers-Kronig analysis of spectra of reflectance has usually been done only with radiation incident as nearly normal to the sample surface as possible. Any effects of obliquity have been assumed to be negligible. However, it is not much more difficult or time consuming to do Kramers-Kronig analysis of spectra taken with almost any angle of incidence, provided that polarized radiation is used to obtain the data. The method for such analysis for radiation incident at almost any angle is described in this paper. The method fails with pi polarized radiation if the angle of incidence lies between the two somewhat different Brewster angles at the high and low frequency ends of the spectrum. The rather small error in a typical analysis caused by neglecting a 15 degrees angle of incidence is illustrated.

  8. An oblique pulsar magnetosphere with a plasma conductivity

    CERN Document Server

    Cao, Gang; Sun, Sineng

    2016-01-01

    An oblique pulsar magnetosphere with a plasma conductivity is studied by using a pseudo-spectral method. In the pseudo-spectral method, the time-dependent Maxwell equations are solved, both electric and magnetic fields are expanded in terms of the vector spherical harmonic (VSH) functions in spherical geometry and the divergencelessness of magnetic field is analytically enforced by a projection method. The pulsar magnetospheres in infinite (i. e., force-free approximation) and finite conductivities are simulated and a family of solutions that smoothly transition from the Deutsch vacuum solution to the force-free solution are obtained. The $\\sin^2\\alpha$ dependence of the spin-down luminosity on the magnetic inclination angle $\\alpha$ in which the full electric current density are taken into account is retrieved in the force-free regime.

  9. Oblique cross-waves in horizontally vibrated containers

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Gracia, José M; Porter, Jeff; Varas, Fernando; Vega, José M, E-mail: fernando.varas@upm.es [ETSI Aeronáuticos, Univ. Politécnica de Madrid, Pl. Cardenal Cisneros, 3, 28040 Madrid (Spain)

    2014-08-01

    The excitation of subharmonic waves on the free surface of a horizontally vibrated, rectangular container of liquid is considered and the properties of threshold patterns are obtained and discussed. These waves are generally quasiperiodic and oblique (not aligned with the container walls). The parametric forcing mechanism generated by the harmonic oscillatory bulk flow is assumed to dominate over that associated with harmonic surface waves and a linear theory recently developed by the authors [Perez-Gracia et al 2014 J. Fluid Mech. 739 196–228] is used to compute both the threshold forcing amplitude and the pattern orientation. Two distinct regimes are considered: (1) large containers where the subharmonic waves generated at each endwall do not interact appreciably and (2) smaller containers where interaction occurs. The nature of the critical eigenfunction is examined in each case, and a contrast drawn between pure 2:1 resonance and the general case of quasiperiodic instability. (paper)

  10. A simple oblique dip model for geomagnetic micropulsations

    Directory of Open Access Journals (Sweden)

    J. A. Lawrie

    Full Text Available It is pointed out that simple models adopted so far have tended to neglect the obliquity of the magnetic field lines entering the Earth's surface. A simple alternative model is presented, in which the ambient field lines are straight, but enter wedge shaped boundaries at half a right-angle. The model is illustrated by assuming an axially symmetric, compressional, impulse type disturbance at the outer boundary, all other boundaries being assumed to be perfectly conducting. The numerical method used is checked from the instant the excitation ceases, by an analytical method. The first harmonic along field lines is found to be of noticeable size, but appears to be mainly due to coupling with the fundamental, and with the first harmonic across field lines.

    Key words. Magnetospheric physics (MHD waves and instabilities.

  11. Photogrammetric Processing of Apollo 15 Metric Camera Oblique Images

    Science.gov (United States)

    Edmundson, K. L.; Alexandrov, O.; Archinal, B. A.; Becker, K. J.; Becker, T. L.; Kirk, R. L.; Moratto, Z. M.; Nefian, A. V.; Richie, J. O.; Robinson, M. S.

    2016-06-01

    The integrated photogrammetric mapping system flown on the last three Apollo lunar missions (15, 16, and 17) in the early 1970s incorporated a Metric (mapping) Camera, a high-resolution Panoramic Camera, and a star camera and laser altimeter to provide support data. In an ongoing collaboration, the U.S. Geological Survey's Astrogeology Science Center, the Intelligent Robotics Group of the NASA Ames Research Center, and Arizona State University are working to achieve the most complete cartographic development of Apollo mapping system data into versatile digital map products. These will enable a variety of scientific/engineering uses of the data including mission planning, geologic mapping, geophysical process modelling, slope dependent correction of spectral data, and change detection. Here we describe efforts to control the oblique images acquired from the Apollo 15 Metric Camera.

  12. Bipolar supernova remnants and the obliquity dependence of shock acceleration

    Science.gov (United States)

    Fulbright, Michael S.; Reynolds, Stephen P.

    1990-01-01

    The diffusive shock acceleration mechanism proposed to explain the bipolarity observed in the synchrotron radio emission of young adiabatically expanding shell SNRs is investigated by means of numerical simulations. The theoretical basis of the SNR models and the numerical computation methods are explained, and the results are presented in graphs and synthetic radio maps and discussed in detail. It is found that the efficiency of the acceleration process depends on the obliquity angle theta(Bn) between the shock normal and the uniform magnetic field: models with theta(Bn) of about 90 deg can reproduce the observed azimuthal intensity ratios in most cases, but models with theta(Bn) near 0 deg cannot.

  13. Bipolar supernova remnants and the obliquity dependence of shock acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Fulbright, M.S.; Reynolds, S.P. (North Carolina State Univ., Raleigh (USA))

    1990-07-01

    The diffusive shock acceleration mechanism proposed to explain the bipolarity observed in the synchrotron radio emission of young adiabatically expanding shell SNRs is investigated by means of numerical simulations. The theoretical basis of the SNR models and the numerical computation methods are explained, and the results are presented in graphs and synthetic radio maps and discussed in detail. It is found that the efficiency of the acceleration process depends on the obliquity angle theta(Bn) between the shock normal and the uniform magnetic field: models with theta(Bn) of about 90 deg can reproduce the observed azimuthal intensity ratios in most cases, but models with theta(Bn) near 0 deg cannot. 32 refs.

  14. Distinct element analysis of overburden subjected to reverse oblique-slip fault

    Science.gov (United States)

    Taniyama, Hisashi

    2017-03-01

    The deformation of overburden subjected to a reverse oblique-slip fault was examined in this study using the distinct element method, and the results were compared with the shears measured at the Nojima fault during the 1995 Hyogoken Nanbu earthquake. Shear deformation was found to occur mainly on the footwall side of the overburden in a narrow zone and to be caused by the reverse fault component. The stress due to both the reverse fault and strike-slip movement led to the development of failure surfaces with a convex-upward shape in cross section and an en echelon pattern in plan view. The width of the zones of high incremental strain obtained in the present analysis was found to be in agreement with the observed width of the shears; however, the observed and simulated intervals and orientations of the shears did not agree. The simulation results suggest that short shears that form in the deep part in the early stages of the deformation join to form longer shears as they propagate toward the surface.

  15. Asymmetric diffusion model for oblique-incidence reflectometry

    Institute of Scientific and Technical Information of China (English)

    Yaqin Chen; Liji Cao; Liqun Sun

    2011-01-01

    A diffusion theory model induced by a line source distribution is presented for oblique-incidence reflectom-etry. By fitting to this asymmetric diffusion model, the absorption and reduced scattering coefficients μa and μ's of the turbid medium can both be determined with accuracy of 10% from the absolute profile of the diffuse reflectance in the incident plane at the negative position -1.5 transport mean free path (mfp') away from the incident point; particularly, μ's can be estimated from the data at positive positions within 0-1.0 mfp' with 10% accuracy. The method is verified by Monte Carlo simulations and experimentally tested on a phantom.%A diffusion theory model induced by a line source distribution is presented for oblique-incidence reflectometry.By fitting to this asymmetric diffusion model,the absorption and reduced scattering coefficients μa and μ's of the turbid medium can both be determined with accuracy of 10% from the absolute profile of the diffuse reflectance in the incident plane at the negative position -1.5 transport mean free path (mfp')away from the incident point;particularly,μ's can be estimated from the data at positive positions within 0-1.0 mfp' with 10% accuracy.The method is verified by Monte Carlo simulations and experimentally tested on a phantom.Knowledge about the optical properties,including the absorption coefficient (μa) and the reduced scattering coefficient (μ's =μs(1-g)),where μs is the scattering coefficient and g is the anisotropy factor of scattering,of biological tissues plays an important role for optical therapeutic and diagnostic techniques in medicine.

  16. Deformation of an experimental drainage network in oblique collision

    Science.gov (United States)

    Guerit, L.; Dominguez, S.; Malavieille, J.; Castelltort, S.

    2016-12-01

    In oblique collision settings, parallel and perpendicular components of the relative plate motion can be partitioned into different structures of deformation and may be localized close to the plate boundary, or distributed on a wider region. In the Southern Alps of New Zealand, it has been proposed that one-third of the regional convergence is distributed in a broad area along the Southern Alps orogenic wedge. To better document and understand the regional dynamics of such systems, reliable markers of the horizontal tectonic motion over geological time scales are needed. River networks are able to record a large amount of distributed strain and they can thus be used to reconstruct the mode and rate of distribution away from major active structures. To explore the controls on river resilience to deformation, we develop an experimental model to investigate river pattern evolution over a doubly-vergent orogenic wedge growing in a context of oblique convergence. We use a rainfall system to activate erosion, sediment transport and river development on the model surface. At the end of the experiment, the drainage network is statistically rotated clockwise, confirming that rivers can record the distribution of motion along the wedge. Image analysis of channel time-space evolution shows how the fault-parallel and fault-perpendicular components of motion decrease toward the fault and impose rotation to the main trunk valleys. However, rivers do not record the whole imposed rotation rate, which suggest that the natural lateral channel dynamics can alter the capacity of rivers to act as passive markers of deformation.

  17. Obliquity-paced Pliocene West Antarctic ice sheet oscillations

    Science.gov (United States)

    Naish, T.; Powell, R.; Levy, R.; Wilson, G.; Scherer, R.; Talarico, F.; Krissek, L.; Niessen, F.; Pompilio, M.; Wilson, T.; Carter, L.; DeConto, R.; Huybers, P.; McKay, R.; Pollard, D.; Ross, J.; Winter, D.; Barrett, P.; Browne, G.; Cody, R.; Cowan, E.; Crampton, J.; Dunbar, G.; Dunbar, N.; Florindo, F.; Gebhardt, C.; Graham, I.; Hannah, M.; Hansaraj, D.; Harwood, D.; Helling, D.; Henrys, S.; Hinnov, L.; Kuhn, G.; Kyle, P.; Laufer, A.; Maffioli, P.; Magens, D.; Mandernack, K.; McIntosh, W.; Millan, C.; Morin, R.; Ohneiser, C.; Paulsen, T.; Persico, D.; Raine, I.; Reed, J.; Riesselman, C.; Sagnotti, L.; Schmitt, D.; Sjunneskog, C.; Strong, P.; Taviani, M.; Vogel, S.; Wilch, T.; Williams, T.

    2009-01-01

    Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (???5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, ???40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to ???3??C warmer than today and atmospheric CO 2 concentration was as high as ???400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO2. ??2009 Macmillan Publishers Limited. All rights reserved.

  18. Analysis of Knee Joint Line Obliquity after High Tibial Osteotomy.

    Science.gov (United States)

    Oh, Kwang-Jun; Ko, Young Bong; Bae, Ji Hoon; Yoon, Suk Tae; Kim, Jae Gyoon

    2016-11-01

    The aim of this study was to evaluate which lower extremity alignment (knee and ankle joint) parameters affect knee joint line obliquity (KJLO) in the coronal plane after open wedge high tibial osteotomy (OWHTO). Overall, 69 knees of patients that underwent OWHTO were evaluated using radiographs obtained preoperatively and from 6 weeks to 3 months postoperatively. We measured multiple parameters of knee and ankle joint alignment (hip-knee-ankle angle [HKA], joint line height [JLH], posterior tibial slope [PS], femoral condyle-tibial plateau angle [FCTP], medial proximal tibial angle [MPTA], mechanical lateral distal femoral angle [mLDFA], KJLO, talar tilt angle [TTA], ankle joint obliquity [AJO], and the lateral distal tibial ground surface angle [LDTGA]; preoperative [-pre], postoperative [-post], and the difference between -pre and -post values [-Δ]). We categorized patients into two groups according to the KJLO-post value (the normal group [within ± 4 degrees, 56 knees] and the abnormal group [greater than ± 4 degrees, 13 knees]), and compared their -pre parameters. Multiple logistic regression analysis was used to examine the contribution of the -pre parameters to abnormal KJLO-post. The mean HKA-Δ (-9.4 ± 4.7 degrees) was larger than the mean KJLO-Δ (-2.1 ± 3.2 degrees). The knee joint alignment parameters (the HKA-pre, FCTP-pre) differed significantly between the two groups (p knee joint alignment and knee joint convergence angle evaluated by HKA-pre and FCTP-pre angle, respectively, were significant predictors of abnormal KJLO after OWHTO. However, -pre ankle joint parameters were not significantly associated with abnormal KJLO after OWHTO.

  19. Rupture of the Distal Biceps Tendon Combined with a Supinator Muscle Tear in a 51-Year-Old Woman: A Case Report

    Directory of Open Access Journals (Sweden)

    Samir Nayyar

    2011-01-01

    Full Text Available Distal biceps tendon rupture is a relatively uncommon occurrence in the general female population, and to our knowledge, has not been reported in association with a supinator muscle tear. We report a case of 51-year-old woman who experienced sharp pain in her forearm and elbow after lifting a heavy object. History and physical examination raised suspicion for a distal biceps tendon rupture. MRI imaging determined a combined distal biceps tendon tear with a supinator muscle tear with subsequent confirmation at surgery. Surgical repair was performed for the distal biceps tendon only through a single incision approach using the Endobutton technique.

  20. Investigation of helicity-dependent photocurrent at room temperature from a Fe/x-AlO x /p-GaAs Schottky junction with oblique surface illumination

    Science.gov (United States)

    Roca, Ronel Christian; Nishizawa, Nozomi; Nishibayashi, Kazuhiro; Munekata, Hiro

    2017-04-01

    In view of a study on spin-polarized photodiodes, the helicity-dependent photocurrent (ΔI) in a Fe/γ-AlO x /p-GaAs Schottky diode is measured at room temperature by illuminating a circularly polarized light beam (λ = 785 nm) either horizontally on the cleaved sidewall or at an oblique angle on the top metal surface. The plane of incidence is fixed to be parallel to the magnetization vector of the in-plane magnetized Fe electrode. The conversion efficiency F, which is a relative value of ΔI with respect to the total photocurrent I ph, is determined to be 1.0 × 10-3 and 1.2 × 10-2 for sidewall illumination and oblique-angle illumination, respectively. Experimental data are compared with the results of a model calculation consisting of drift-diffusion and Julliere spin-dependent tunneling transports, from which two conclusions are obtained: the model accounts fairly well for the experimental data without introducing the annihilation of spin-polarized carriers at the γ-AlO x /p-GaAs interface for the oblique-angle illumination, but the model does not fully explain the relatively low F in terms of the surface recombination at the cleaved sidewall in the case of sidewall illumination. Microscopic damage to the tunneling barrier at the cleaved edge would be one possible cause of the reduced F.

  1. Two Upper Limits on the Rossiter-McLaughlin Effect, with Differing Implications: WASP-1 has a High Obliquity and WASP-2 is Indeterminate

    CERN Document Server

    Albrecht, Simon; Johnson, John Asher; Butler, R Paul; Crane, Jeffrey D; Shectman, Stephen A; Thompson, Ian B; Narita, Norio; Sato, Bun'ei; Hirano, Teruyuki; Enya, Keigo; Fischer, Debra

    2011-01-01

    We present precise radial-velocity measurements of WASP-1 and WASP-2 throughout transits of their giant planets. Our goal was to detect the Rossiter-McLaughlin (RM) effect, the anomalous radial velocity observed during eclipses of rotating stars, which can be used to study the obliquities of planet-hosting stars. For WASP-1 a weak signal of a prograde orbit was detected with ~2sigma confidence, and for WASP-2 no signal was detected. The resulting upper bounds on the RM amplitude have different implications for these two systems, because of the contrasting transit geometries and the stellar types. Because WASP-1 is an F7V star, and such stars are typically rapid rotators, the most probable reason for the suppression of the RM effect is that the star is viewed nearly pole-on. This implies the WASP-1 star has a high obliquity with respect to the edge-on planetary orbit. Because WASP-2 is a K1V star, and is expected to be a slow rotator, no firm conclusion can be drawn about the stellar obliquity. Our data and ou...

  2. TOWARDS A MORE EFFICIENT DETECTION OF EARTHQUAKE INDUCED FAÇADE DAMAGES USING OBLIQUE UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    D. Duarte

    2017-08-01

    Full Text Available Urban search and rescue (USaR teams require a fast and thorough building damage assessment, to focus their rescue efforts accordingly. Unmanned aerial vehicles (UAV are able to capture relevant data in a short time frame and survey otherwise inaccessible areas after a disaster, and have thus been identified as useful when coupled with RGB cameras for façade damage detection. Existing literature focuses on the extraction of 3D and/or image features as cues for damage. However, little attention has been given to the efficiency of the proposed methods which hinders its use in an urban search and rescue context. The framework proposed in this paper aims at a more efficient façade damage detection using UAV multi-view imagery. This was achieved directing all damage classification computations only to the image regions containing the façades, hence discarding the irrelevant areas of the acquired images and consequently reducing the time needed for such task. To accomplish this, a three-step approach is proposed: i building extraction from the sparse point cloud computed from the nadir images collected in an initial flight; ii use of the latter as proxy for façade location in the oblique images captured in subsequent flights, and iii selection of the façade image regions to be fed to a damage classification routine. The results show that the proposed framework successfully reduces the extracted façade image regions to be assessed for damage 6 fold, hence increasing the efficiency of subsequent damage detection routines. The framework was tested on a set of UAV multi-view images over a neighborhood of the city of L’Aquila, Italy, affected in 2009 by an earthquake.

  3. Comparison of lumbar lordosis in lateral radiographs in standing position with supine MR imaging in consideration of the sacral slope

    Energy Technology Data Exchange (ETDEWEB)

    Benditz, Achim; Boluki, Daniel; Weber, Markus; Grifka, Joachim; Voellner, Florian [Regensburg Univ. Medical Center (Germany). Orthopedic Surgery; Zeman, Florian [Regensburg Univ. Medical Center (Germany). Center for Clinical Studies

    2017-03-15

    To investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking. MR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification. Global lumbar lordosis (L1-S1) was 44.99 (± 10754) on radiographs and 47.91 (±9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p < 0.01). Measurements of single level lordosis only showed minor differences. At all levels except for L5 / S1, lordosis measured by means of standing radiographs was higher than that measured by MRI. The difference in global lumbar L1-S1 lordosis was -2.9 . Analysis of the Roussouly groups showed the largest difference for L1-S1 (-8.3 ) in group 2. In group 4, when measured on MRI, L5 / S1 lordosis (25.71 ) was lower than L4 / L5 lordosis (27.63 ) compared to the other groups. Although measurements of global lumbar lordosis significantly differed between the two scanning technologies, the mean difference was just 2.9 . MRI in supine position may be used for estimating global lumbar lordosis, but single level lordosis should be determined by means of standing radiographs.

  4. Incidence of Peroneal Tendinopathy After Application of a Posterior Antiglide Plate for Repair of Supination External Rotation Lateral Malleolar Fractures.

    Science.gov (United States)

    Ahn, Jungtae; Kim, Sehun; Lee, Jung-Soo; Woo, Kyungjei; Sung, Ki-Sun

    2016-01-01

    Posterior antiglide plating is widely used to treat lateral malleolar fractures caused by supination-external rotation injuries. Despite its widespread use, this technique can be associated with postoperative peroneal tendinopathy. The purpose of the present observational review was to report the incidence of peroneal tendinopathy after the use of posterior antiglide plating to treat lateral malleolar fractures caused by a supination-external rotation injury. A total of 70 patients were followed up for a minimum of 12 (mean 55, range 12 to 109) months. Bony union was obtained in all cases after a mean of 57 (range 37 to 81) days. The median number of screw holes in the plate was 4.9 (range 4 to 7), and the median number of screws used to fixate the fibula was 6.58 (range 5 to 10). The mean American Orthopaedic Foot and Ankle Society hindfoot-ankle score at the final follow-up examination was 90.8 (range 55 to 100). Clinically, 3 (4.29%) of the 70 patients had lateral or posterolateral ankle pain indicative of peroneal tendinopathy after the index surgery, without any objective evidence. Of the 70 patients, 41 (58.57%) underwent surgical removal of the fibular hardware, 2 (4.87%) because of lateral ankle discomfort. At removal, inspection of the peroneal tendon sheath and/or tendons showed no gross evidence of tendinopathy in any of the patients. We concluded that the incidence of clinically evident peroneal tendon symptoms associated with posterior antiglide plating is low (4.3%), and direct operative inspection revealed no gross evidence of tendinopathy. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Obliquity of the Galilean satellites: The influence of a global internal liquid layer

    CERN Document Server

    Baland, R -M; Van Hoolst, T

    2012-01-01

    The obliquity of the Galilean satellites is small but not yet observed. Studies of cycloidal lineaments and strike-slip fault patterns on Europa suggest that Europa's obliquity is about 1 deg, although theoretical models of the obliquity predict the obliquity to be one order of magnitude smaller for an entirely solid Europa. Here, we investigate the influence of a global liquid layer on the obliquity of the Galilean satellites. Io most likely has a fully liquid core, while Europa, Ganymede, and Callisto are thought to have an internal global liquid water ocean beneath an external ice shell. We use a model for the obliquity based on a Cassini state model extended to the presence of an internal liquid layer and the internal gravitational and pressure torques induced by the presence of this layer. We find that the obliquity of Io only weakly depends on the different internal structure models considered, because of the weak influence of the liquid core which is therefore almost impossible to detect through observ...

  6. Oblique synoptic images, produced from digital data, display strong evidence of a "new" caldera in southwestern Guatemala

    Science.gov (United States)

    Duffield, W.; Heiken, G.; Foley, D.; McEwen, A.

    1993-01-01

    The synoptic view of broad regions of the Earth's surface as displayed in Landsat and other satellite images has greatly aided in the recognition of calderas, ignimbrite plateaus and other geologic landforms. Remote-sensing images that include visual representation of depth are an even more powerful tool for geologic interpretation of landscapes, but their use has been largely restricted to the exploration of planets other than Earth. By combining Landsat images with digitized topography, we have generated regional oblique views that display compelling evidence for a previously undocumented late-Cenozoic caldera within the active volcanic zone of southwestern Guatemala. This "new" caldera, herein called Xela, is a depression about 30 km wide and 400-600 m deep, which includes the Quezaltenango basin. The caldera depression is breached only by a single river canyon. The caldera outline is broadly circular, but a locally scalloped form suggests the occurrence of multiple caldera-collapse events, or local slumping of steep caldera walls, or both. Within its northern part, Xela caldera contains a toreva block, about 500 m high and 2 km long, that may be incompletely foundered pre-caldera bedrock. Xela contains several post-caldera volcanoes, some of which are active. A Bouguer gravity low, tens of milligals in amplitude, is approximately co-located with the proposed caldera. The oblique images also display an extensive plateau that dips about 2?? away from the north margin of Xela caldera. We interpret this landform to be underlain by pyroclastic outflow from Xela and nearby Atitla??n calderas. Field mapping by others has documented a voluminous rhyolitic pumiceous fallout deposit immediately east of Xela caldera. We speculate that Xela caldera was the source of this deposit. If so, the age of at least part of the caldera is between about 84 ka and 126 ka, the ages of deposits that stratigraphically bracket this fallout. Most of the floor of Xela caldera is covered

  7. Compensation of corneal oblique astigmatism by internal optics: a theoretical analysis.

    Science.gov (United States)

    Liu, Tao; Thibos, Larry N

    2017-05-01

    Oblique astigmatism is a prominent optical aberration of peripheral vision caused by oblique incidence of rays striking the refracting surfaces of the cornea and crystalline lens. We inquired whether oblique astigmatism from these two sources should be expected, theoretically, to have the same or opposite signs across the visual field at various states of accommodation. Oblique astigmatism was computed across the central visual field for a rotationally-symmetric schematic-eye using optical design software. Accommodative state was varied by altering the apical radius of curvature and separation of the biconvex lens's two aspheric surfaces in a manner consistent with published biometry. Oblique astigmatism was evaluated separately for the whole eye, the cornea, and the isolated lens over a wide range of surface curvatures and asphericity values associated with the accommodating lens. We also computed internal oblique astigmatism by subtracting corneal oblique astigmatism from whole-eye oblique astigmatism. A visual field map of oblique astigmatism for the cornea in the Navarro model follows the classic, textbook description of radially-oriented axes everywhere in the field. Despite large changes in surface properties during accommodation, intrinsic astigmatism of the isolated human lens for collimated light is also radially oriented and nearly independent of accommodation both in theory and in real eyes. However, the magnitude of ocular oblique astigmatism is smaller than that of the cornea alone, indicating partial compensation by the internal optics. This implies internal oblique astigmatism (which includes wavefront propagation from the posterior surface of the cornea to the anterior surface of the lens and intrinsic lens astigmatism) must have tangentially-oriented axes. This non-classical pattern of tangential axes for internal astigmatism was traced to the influence of corneal power on the angles of incidence of rays striking the internal lens. Partial

  8. Shoulder magnetic resonance arthrography in the sagittal oblique plane: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, G.; Forster, B.; Cheong, Y.; Sidhu, G. [Univ. of British Columbia, Dept. of Radiology, Vancouver, British Columbia (Canada); Hawkins, R.; Leith, J. [Univ. of British Columbia, Dept. of Orthopedics, Vancouver, British Columbia (Canada)

    2003-06-01

    Shoulder magnetic resonance (MR) arthrography is the imaging study of choice for investigating glenohumeral instability. The axial and coronal oblique planes have traditionally been used because it is on these planes that the glenoid labrum, as well as the biceps anchor and rotator cuff, are thought to be best evaluated. The purpose of this illustrative review is to demonstrate the diagnostic utility of the sagittal oblique plane in shoulder MR arthrography. Images identifying the normal and abnormal appearance of the labral, ligamentous, myotendinous and osteocartilaginous structures are presented, and comparisons to the axial and coronal oblique planes are made. (author)

  9. Experimental study on mean overtopping of sloping seawall under oblique irregular waves

    Science.gov (United States)

    Wang, Deng-ting; Ju, Lie-hong; Zhu, Jia-ling; Wang, Zhen; Sun, Tian-ting; Chen, Wei-qiu

    2017-06-01

    In this paper, domestic and abroad research progresses and related calculation formulae of the mean overtopping discharge are summarized. Through integral physical model experiments, the relation between the wave direction and the overtopping discharge on the top of the sloping dike is focused on and put into analysis and discussion; and a modified formula for mean overtopping discharges under oblique irregular waves is proposed. The study shows that the mean overtopping discharge generally goes down as the relative wave obliquity β increases for a fixed measurement point and the mean overtopping discharge generally increases as the wave steepness H/L decreases (the cycle increases) for a fixed relative wave obliquity.

  10. Large artificial anisotropic growth rate in on-lattice simulation of obliquely deposited nanostructures

    Science.gov (United States)

    Tanto, B.; Doiron, C. F.; Lu, T.-M.

    2011-01-01

    On-lattice particle simulation is one of the most common types of Monte Carlo simulations used in studying the dynamics of film growth. We report the observation of a large artificial anisotropic growth rate variation owing to the fixed arrangement of particles in an on-lattice simulation of oblique angle deposition. This unexpectedly large anisotropy is not reported in previous literatures and substantially affects the simulation outcomes such as column angle and porosity, two of the most essential quantities in obliquely deposited nanostructures. The result of our finding is of interest to all on-lattice simulations in obliquely deposited films or nanostructures.

  11. Low to high oblique ramus piezoosteotomy: a pilot study.

    Science.gov (United States)

    Landes, Constantin; Tran, Andreas; Ballon, Alexander; Santo, Gregor; Schübel, Florian; Sader, Robert

    2014-09-01

    Two major drawbacks of classical bilateral sagittal split osteotomy (BSSO) are occasional inferior alveolar nerve damage and bad splits. In order to avoid these two well-known disadvantages and benefit from ultrasonic bone cutting, a low-to-high oblique piezoosteotomy (LHO) was developed from Schlössmann's 1922 high oblique osteotomy, clinically evaluated with a standard and a novel osteosynthesis system. Eighty-five patients were retrospectively evaluated, 23 with an LHO osteotomy with standard osteosynthesis, 33 LHO with a dedicated plate osteosynthesis and compared to 29 patients with BSSO and standard osteosyntheses. The mean mandibular advancement in the LHO standard osteosynthesis/LHO dedicated plate osteosynthesis/BSSO collectives was 4.7 ± 2.5/7.8 ± 7.1/4.1 ± 2.8 mm, the mean one year relapse 2.6 ± 0.8 (p = 0.58)/1.4 ± 1.4 (p = 0.28)/2.1 ± 1.4 mm; the mean mandibular setback was 6.9 ± 3.6/7.7 ± 4.1/8.1 ± 4.9 mm and the one year relapse 2.9 ± 2.9 (p = 0.16)/1.4 ± 1.0 (p = 0.38)/1.5 ± 1.9 mm; clockwise rotation of the mandible was 5.2 ± 3.2/6.3 ± 5.1/10.2 ± 6.9°, the one year relapse 2.7 ± 1.2 (p = 0.18)/2.1 ± 1.7 (p = 0.09)/11.4 ± 9.3°; counterclockwise rotation averaged 6.4 ± 3.2/6.5 ± 7.9/6.5 ± 6.1° with a mean one year relapse of 3.3 ± 0.6 (p = 0.37)/3.7 ± 1.9 (p = 0.21)/4.5 ± 6.2°. LHO had 3%, BSSO 5% three months postoperative inferior alveolar nerve deficit (p = 0.17). The operation time was significantly shorter when LHO and dedicated plates were used compared to BSSO. Two broken conventional plates occurred in LHO, which stimulated the development of the dedicated plates used, one in BSSO; four bad splits in BSSO and two in LHO. Reosteosyntheses were performed using the newly developed dedicated "orthognathics" plate. LHO was successfully performed, easier and faster than BSSO. Gonial angle modifications were possible due to the oblique cut

  12. Feasibility of monitoring patient motion with opposed stereo infrared cameras during supine medical imaging

    Science.gov (United States)

    Beach, Richard D.; McNamara, Joseph E.; Terlecki, George; King, Michael A.

    2006-10-01

    Patient motion during single photon emission computed tomographic (SPECT) acquisition causes inconsistent projection data and reconstruction artifacts which can significantly affect diagnostic accuracy. We have investigated use of the Polaris stereo infrared motion-tracking system to track 6-Degrees-of-Freedom (6-DOF) motion of spherical reflectors (markers) on stretchy bands about the patient's chest and abdomen during cardiac SPECT imaging. The marker position information, obtained by opposed stereo infrared-camera systems, requires processing to correctly record tracked markers, and map Polaris co-ordinate data into the SPECT co-ordinate system. One stereo camera views the markers from the patient's head direction, and the other from the patient's foot direction. The need for opposed cameras is to overcome anatomical and geometrical limitations which sometimes prevent all markers from being seen by a single stereo camera. Both sets of marker data are required to compute rotational and translational 6-DOF motion of the patient which ultimately will be used for SPECT patient-motion corrections. The processing utilizes an algorithm involving least-squares fitting, to each other, of two 3-D point sets using singular value decomposition (SVD) resulting in the rotation matrix and translation of the rigid body centroid. We have previously demonstrated the ability to monitor multiple markers for twelve patients viewing from the foot end, and employed a neural network to separate the periodic respiratory motion component of marker motion from aperiodic body motion. We plan to initiate routine 6-DOF tracking of patient motion during SPECT imaging in the future, and are herein evaluating the feasibility of employing opposed stereo cameras.

  13. Supine Lateral Bending Radiographs Predict the Initial In-brace Correction of the Providence Brace in Patients With Adolescent Idiopathic Scoliosis

    DEFF Research Database (Denmark)

    Ohrt-Nissen, Søren; Hallager, Dennis Winge; Gehrchen, Poul Martin

    2016-01-01

    STUDY DESIGN: Retrospective, cross-sectional. OBJECTIVE: To determine the initial curve correction of the providence brace (PB) and to determine to what extend the in-brace Cobb angle corresponds to the curve seen on supine lateral bending radiographs (SLBR). SUMMARY OF BACKGROUND DATA: SLBR are ...

  14. Pleistocene Indian Monsoon rainfall variability dominated by obliquity

    Science.gov (United States)

    Gebregiorgis, D.; Hathorne, E. C.; Giosan, L.; Collett, T. S.; Nuernberg, D.; Frank, M.

    2015-12-01

    The past variability of the Indian Monsoon is mostly known from records of wind strength over the Arabian Sea while Quaternary proxy records of Indian monsoon precipitation are still lacking. Here we utilize scanning x-ray fluorescence (XRF) data from a sediment core obtained by the IODP vessel JOIDES Resolution in the Andaman Sea (Site 17) to investigate changes in sediment supply from the peak monsoon precipitation regions to the core site. We use Ti/Ca and K/Rb ratios to trace changes in terrigenous flux and weathering regime, respectively, while Zr/Rb ratios suggest grain size variations. The age model of Site 17 is based on correlation of benthic C. wuellerstorfi/C. mundulus δ18O data to the LR04 global benthic δ18O stack at a resolution of ~3 kyr (Lisiecki and Raymo, 2005) for the last 2 Myrs. In its youngest part the age model is supported by five 14C ages on planktic foraminifera and the youngest Toba ash layer (Ali et al., 2015) resulting in a nearly constant sedimentation rate of ~6.5 cm/kyr. Frequency analysis of the 4 mm resolution Ti/Ca, K/Rb, and Zr/Rb time series using the REDFIT program (Schulz and Mudelsee, 2002), reveals the three main Milankovitch orbital cycles above the 90% confidence level. Depth domain spectral analysis reveals the presence of significant cyclicity at wavelengths of 28.5 and 2.8 m corresponding to the ~400 kyr and ~41 kyr cycles, respectively, during the last 2 Myr. These records suggest that Indian monsoon variability has varied in the obliquity and eccentricity bands, the latter in particular after the mid Pleistocene transition (MPT), while strong precession forcing is lacking in this super-high resolution record. Northern summer insolation and Southern Hemisphere latent heat export are out of phase during precessional cycles, but in phase in the obliquity band, which indicates that Indian monsoon precipitation has likely been more sensitive to both NH pull and SH push mechanisms (Clemens and Prell, 2003). References Ali

  15. Comparison of surface matching and target matching for image-guided pelvic radiation therapy for both supine and prone patient positions.

    Science.gov (United States)

    Zhao, Hui; Wang, Brian; Sarkar, Vikren; Rassiah-Szegedi, Prema; Huang, Y Jessica; Szegedi, Martin; Huang, Long; Gonzalez, Victor; Salter, Bill

    2016-05-01

    We investigate the difference between surface matching and target matching for pelvic radiation image guidance. The uniqueness of our study is that all patients have multiple CT-on-rails (CTOR) scans to compare to corresponding AlignRT images. Ten patients receiving pelvic radiation were enrolled in this study. Two simulation CT scans were performed in supine and prone positions for each patient. Body surface contours were generated in treatment planning system and exported to AlignRT to serve as reference images. During treatment day, the patient was aligned to treatment isocenter with room lasers, and then scanned with both CTOR and AlignRT. Image-guidance shifts were calculated for both modalities by comparison to the simulation CT and the differences between them were analyzed for both supine and prone positions, respectively. These procedures were performed for each patient once per week for five weeks. The difference of patient displacement between AlignRT and CTOR was analyzed. For supine position, five patients had an average difference of displacement between AlignRT and CTOR along any direction (vertical, longitudinal, and lateral) greater than 0.5 cm, and one patient greater than 1 cm. Four patients had a maximum difference greater than 1 cm. For prone position, seven patients had an average difference greater than 0.5 cm, and three patients greater than 1 cm. Nine patients had a maximum difference greater than 1 cm. The difference of displacement between AlignRT and CTOR was greater for the prone position than for the supine position. For the patients studied here, surface matching does not appear to be an advisable image-guidance approach for pelvic radiation therapy for patients with either supine or prone position. There appears to be a potential for large alignment discrepancies (up to 2.25 cm) between surface matching and target matching. PACS number(s): 87.55.-x.

  16. Comparison of surface matching and target matching for image-guided pelvic radiation therapy for both supine and prone patient positions.

    Science.gov (United States)

    Zhao, Hui; Wang, Brian; Sarkar, Vikren; Rassiah-Szegedi, Prema; Huang, Y Jessica; Szegedi, Martin; Huang, Long; Gonzalez, Victor; Salter, Bill

    2016-05-08

    We investigate the difference between surface matching and target matching for pelvic radiation image guidance. The uniqueness of our study is that all patients have multiple CT-on-rails (CTOR) scans to compare to corresponding AlignRT images. Ten patients receiving pelvic radiation were enrolled in this study. Two simulation CT scans were performed in supine and prone positions for each patient. Body surface contours were generated in treatment planning system and exported to AlignRT to serve as reference images. During treatment day, the patient was aligned to treatment isocenter with room lasers, and then scanned with both CTOR and AlignRT. Image-guidance shifts were calculated for both modalities by com-parison to the simulation CT and the differences between them were analyzed for both supine and prone positions, respectively. These procedures were performed for each patient once per week for five weeks. The difference of patient displace-ment between AlignRT and CTOR was analyzed. For supine position, five patients had an average difference of displacement between AlignRT and CTOR along any direction (vertical, longitudinal, and lateral) greater than 0.5 cm, and one patient greater than 1 cm. Four patients had a maximum difference greater than 1 cm. For prone position, seven patients had an average difference greater than 0.5 cm, and three patients greater than 1 cm. Nine patients had a maximum difference greater than 1 cm. The difference of displacement between AlignRT and CTOR was greater for the prone position than for the supine position. For the patients studied here, surface matching does not appear to be an advisable image-guidance approach for pelvic radiation therapy for patients with either supine or prone position. There appears to be a potential for large alignment discrepancies (up to 2.25 cm) between surface matching and target matching.

  17. The local dayside reconnection rate for oblique interplanetary magnetic fields

    CERN Document Server

    Komar, Colin M

    2016-01-01

    We present an analysis of local properties of magnetic reconnection at the dayside magnetopause for various interplanetary magnetic field (IMF) orientations in global magnetospheric simulations. This has heretofore not been practical because it is difficult to locate where reconnection occurs for oblique IMF, but new techniques make this possible. The approach is to identify magnetic separators, the curves separating four regions of differing magnetic topology, which map the reconnection X-line. The electric field parallel to the X-line is the local reconnection rate. We compare results to a simple model of local two-dimensional asymmetric reconnection. To do so, we find the plasma parameters that locally drive reconnection in the magnetosheath and magnetosphere in planes perpendicular to the X-line at a large number of points along the X-line. The global magnetohydrodynamic simulations are from the three-dimensional Block-Adaptive, Tree Solarwind Roe-type Upwind Scheme (BATS-R-US) code with a uniform resisti...

  18. Mars secular obliquity change due to the seasonal polar caps

    Science.gov (United States)

    Rubincam, David P.

    1992-01-01

    There is a weak positive feedback mechanism between the astronomy and meteorology of Mars. The mechanism is this: the seasonal waxing and waning polar caps cause small changes in Mars' dynamical flattening. Because the changes in flattening are out of phase with the sun, there is a net annual solar torque on the planet which increases the angle between the equatorial and orbital phanes. On the basis of Viking observations of the present climate and simple atmospheric models of past climates, these seasonal shifts of mass between the atmosphere and polar caps are capable of secularly increasing Mars' obliquity by about 1 or 2 deg since the origin of the solar system. Thus, the climate, driven largely by the axial tilt, reacts back on the planet and slightly enhances the seasons on Mars as time progresses. More sophisticated models will probably not change this result much; therefore this mechanism probably produced only minor changes in Mars' climate. It causes negligible changes in the axial tilt and climate of the earth.

  19. Oblique corrections in the Dine-Fischler-Srednicki axion model

    Science.gov (United States)

    Katanaeva, Alisa; Espriu, Domènec

    2016-11-01

    In the Minimal Standard Model (MSM) there is no degree of freedom for dark matter. There are several extensions of the MSM introducing a new particle - an invisible axion, which can be regarded as a trustworthy candidate at least for a part of the dark matter component. However, as it is extremely weakly coupled, it cannot be directly measured at the LHC. We propose to explore the electroweak sector indirectly by considering a particular model that includes the axion and derive consequences that could be experimentally tested. We discuss the Dine-Fischler-Srednicki (DFS) model, which extends the two-Higgs doublet model with an additional Peccei-Quinn symmetry and leads to a physically acceptable axion. The non-linear parametrization of the DFS model is exploited in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale. We compute the oblique corrections and use their values from the electroweak experimental fits to put constraints on the mass spectrum of the DFS model.

  20. Behavior of obliquely incident vector Bessel beams at planar interfaces.

    Science.gov (United States)

    Salem, Mohamed A; Bağcı, Hakan

    2013-06-01

    We investigate the behavior of full-vector electromagnetic Bessel beams obliquely incident at an interface between two electrically different media. We employ a Fourier transform domain representation of Bessel beams to determine their behavior upon reflection and transmission. This transform, which is geometric in nature, consists of elliptical support curves with complex weighting associated with them. The behavior of the scattered field at an interface is highly complex, owing to its full-vector nature; nevertheless, this behavior has a straightforward representation in the transform domain geometry. The analysis shows that the reflected field forms a different vector Bessel beam, but in general, the transmitted field cannot be represented as a Bessel beam. Nevertheless, using this approach, we demonstrate a method to propagate a Bessel beam in the refractive medium by launching a non-Bessel beam at the interface. Several interesting phenomena related to the behavior of Bessel beams are illustrated, such as polarized reflection at Brewster's angle incidence, and the Goos-Hänchen and Imbert-Federov shifts in the case of total reflection.

  1. Translation Evaluation: A Comparative Study of an Oblique Translation

    Directory of Open Access Journals (Sweden)

    / Esmail Zare Behtash

    2017-06-01

    Full Text Available Translation is of an absolute necessity in today’s world. Robinson (1997 states that the study of translation is an integral part of intercultural relations and of conveying scientific and technological knowledge. He further mentions that “translators need to be able to process linguistic materials quickly and efficiently; but they also need to be able to recognize problem areas and to slow down to solve them in complex analytical ways” (p. 2. This study is an attempt to explore and evaluate an oblique translation of a text from English into Persian to find the most frequent translation strategy. To reach the goal of the study, the researchers selected one hundred and ten sentences of an original English text which had been translated freely at random and compared them with their Persian counterparts. The findings of the study indicated that Persian translator used equivalent strategy with the highest percentage (45% in the translated corpus. After that, modulation, and transposition had the highest percentages respectively.

  2. Oblique Colloidal Lithography for the Fabrication of Nonconcentric Features.

    Science.gov (United States)

    Zhao, Zhi; Cao, Yang; Cai, Yangjun; Yang, Jian; He, Ximin; Nordlander, Peter; Cremer, Paul S

    2017-07-25

    Herein, we describe the development of oblique colloidal lithography (OCL) and establish a systematic patterning strategy for creating libraries of nanosized nonconcentric plasmonic structures. This strategy combines OCL, capillary force lithography, and several wet and ion etching steps. Hexagonal arrays of nonconcentric gold features were created on glass substrates with highly controllable geometric parameters. The size, geometry, and eccentricity of the gold features could be independently tuned by controlling the experimental conditions. Gaps within surface elements could be shrunk to as small as 30 nm, while the total patterned area was about l cm(2). The goal was to devise a method that offers a high degree of control over the resolution and morphology of asymmetric structures without the need to resort to electron beam lithography. This technique also enabled the development of numerous surface patterns through the stepwise fabrication of separate elements. Complex features, including dots-surrounded nonconcentric targets, nonconcentric hexagram-disks, and nonconcentric annular aperture arrays, were demonstrated, and their optical properties were characterized. Indeed, spectroscopic studies and FDTD simulations demonstrated that Fano resonances could readily be generated by the nonconcentric gold features. Consequently, our patterning strategy should enable the high-throughput investigation of plasmonic coupling and Fano resonances as a function of the physical parameters of the elements within the nanopattern array.

  3. Subsurface damage from oblique impacts into low-impedance layers

    Science.gov (United States)

    Stickle, A. M.; Schultz, P. H.

    2012-07-01

    Layered planetary surfaces occur ubiquitously in the solar system, where sedimentary sequences or icy layers overlay crystalline bedrock. Previous experimental studies investigated how the presence of weak layer overlying a strong basement affects crater morphology, subsurface damage and soft-sediment compression. Numerical studies generally focus on the final morphology as a function of thicknesses and burial depths of weak layers. In field studies of impact craters, the shock state of minerals is a key metric. Here, we evaluate the effect of a surficial low-impedance layer on peak pressure magnitudes and consequent damage extent in the competent substrate. Laboratory experiments coupled with 3D CTH models of oblique (30° from horizontal) hypervelocity impacts at laboratory and planetary scales show that surface layers with a thickness on the order of the projectile diameter shield the underlying surface and absorb/scatter ˜70% of the impact energy. Numerical simulations reveal that surficial layers reduce peak pressure magnitudes within the subsurface by ˜60-70%, while damage in the substrate is due to shear failure. Sedimentary layers are more efficient shields than icy layers, but both reduce the extent of subsurface damage and the resulting shock levels recorded by minerals. These results indicate that a thin surficial low impedance layer mitigates the expression of shocked minerals in the substrate even when a structural response is still observed.

  4. Anatomical Characteristics and Biomechanical Properties of the Oblique Popliteal Ligament

    Science.gov (United States)

    Wu, Xiang-Dong; Yu, Jin-Hui; Zou, Tao; Wang, Wei; LaPrade, Robert F.; Huang, Wei; Sun, Shan-Quan

    2017-01-01

    This anatomical study sought to investigate the morphological characteristics and biomechanical properties of the oblique popliteal ligament (OPL). Embalmed cadaveric knees were used for the study. The OPL and its surrounding structures were dissected; its morphology was carefully observed, analyzed and measured; its biomechanical properties were investigated. The origins and insertions of the OPL were relatively similar, but its overall shape was variable. The OPL had two origins: one originated from the posterior surface of the posteromedial tibia condyle, merged with fibers from the semimembranosus tendon, the other originated from the posteromedial part of the capsule. The two origins converged and coursed superolaterally, then attached to the fabella or to the tendon of the lateral head of the gastrocnemius and blended with the posterolateral joint capsule. The OPL was classified into Band-shaped, Y-shaped, Z-shaped, Trident-shaped, and Complex-shaped configurations. The mean length, width, and thickness of the OPL were 39.54, 22.59, and 1.44 mm, respectively. When an external rotation torque (18 N·m) was applied both before and after the OPL was sectioned, external rotation increased by 8.4° (P = 0.0043) on average. The OPL was found to have a significant role in preventing excessive external rotation and hyperextension of the knee. PMID:28205540

  5. Behavior of obliquely incident vector Bessel beams at planar interfaces

    KAUST Repository

    Salem, Mohamed

    2013-01-01

    We investigate the behavior of full-vector electromagnetic Bessel beams obliquely incident at an interface between two electrically different media. We employ a Fourier transform domain representation of Bessel beams to determine their behavior upon reflection and transmission. This transform, which is geometric in nature, consists of elliptical support curves with complex weighting associated with them. The behavior of the scattered field at an interface is highly complex, owing to its full-vector nature; nevertheless, this behavior has a straightforward representation in the transform domain geometry. The analysis shows that the reflected field forms a different vector Bessel beam, but in general, the transmitted field cannot be represented as a Bessel beam. Nevertheless, using this approach, we demonstrate a method to propagate a Bessel beam in the refractive medium by launching a non- Bessel beam at the interface. Several interesting phenomena related to the behavior of Bessel beams are illustrated, such as polarized reflection at Brewster\\'s angle incidence, and the Goos-Hänchen and Imbert-Federov shifts in the case of total reflection. © 2013 Optical Society of America.

  6. Obliquely propagating large amplitude solitary waves in charge neutral plasmas

    Directory of Open Access Journals (Sweden)

    F. Verheest

    2007-01-01

    Full Text Available This paper deals in a consistent way with the implications, for the existence of large amplitude stationary structures in general plasmas, of assuming strict charge neutrality between electrons and ions. With the limit of pair plasmas in mind, electron inertia is retained. Combining in a fluid dynamic treatment the conservation of mass, momentum and energy with strict charge neutrality has indicated that nonlinear solitary waves (as e.g. oscillitons cannot exist in electron-ion plasmas, at no angle of propagation with respect to the static magnetic field. Specifically for oblique propagation, the proof has turned out to be more involved than for parallel or perpendicular modes. The only exception is pair plasmas that are able to support large charge neutral solitons, owing to the high degree of symmetry naturally inherent in such plasmas. The nonexistence, in particular, of oscillitons is attributed to the breakdown of the plasma approximation in dealing with Poisson's law, rather than to relativistic effects. It is hoped that future space observations will allow to discriminate between oscillitons and large wave packets, by focusing on the time variability (or not of the phase, since the amplitude or envelope graphs look very similar.

  7. The "diagonal effect": a systematic error in oblique antisaccades.

    Science.gov (United States)

    Koehn, John D; Roy, Elizabeth; Barton, Jason J S

    2008-08-01

    Antisaccades are known to show greater variable error and also a systematic hypometria in their amplitude compared with visually guided prosaccades. In this study, we examined whether their accuracy in direction (as opposed to amplitude) also showed a systematic error. We had human subjects perform prosaccades and antisaccades to goals located at a variety of polar angles. In the first experiment, subjects made prosaccades or antisaccades to one of eight equidistant locations in each block, whereas in the second, they made saccades to one of two equidistant locations per block. In the third, they made antisaccades to one of two locations at different distances but with the same polar angle in each block. Regardless of block design, the results consistently showed a saccadic systematic error, in that oblique antisaccades (but not prosaccades) requiring unequal vertical and horizontal vector components were deviated toward the 45 degrees diagonal meridians. This finding could not be attributed to range effects in either Cartesian or polar coordinates. A perceptual origin of the diagonal effect is suggested by similar systematic errors in other studies of memory-guided manual reaching or perceptual estimation of direction, and may indicate a common spatial bias when there is uncertain information about spatial location.

  8. Aerial Photography and Imagery, Oblique, Pictometry Imagery, Published in 2009, North Georgia College and State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Oblique dataset, was produced all or in part from Orthoimagery information as of 2009. It is described as 'Pictometry Imagery'....

  9. OBLIQUE MULTI-CAMERA SYSTEMS – ORIENTATION AND DENSE MATCHING ISSUES

    Directory of Open Access Journals (Sweden)

    E. Rupnik

    2014-03-01

    Full Text Available The use of oblique imagery has become a standard for many civil and mapping applications, thanks to the development of airborne digital multi-camera systems, as proposed by many companies (Blomoblique, IGI, Leica, Midas, Pictometry, Vexcel/Microsoft, VisionMap, etc.. The indisputable virtue of oblique photography lies in its simplicity of interpretation and understanding for inexperienced users allowing their use of oblique images in very different applications, such as building detection and reconstruction, building structural damage classification, road land updating and administration services, etc. The paper reports an overview of the actual oblique commercial systems and presents a workflow for the automated orientation and dense matching of large image blocks. Perspectives, potentialities, pitfalls and suggestions for achieving satisfactory results are given. Tests performed on two datasets acquired with two multi-camera systems over urban areas are also reported.

  10. Determining optical properties of epithelial tissues with an obliquely incident beam

    Science.gov (United States)

    Rohde, Shelley B.; Kim, Arnold D.

    2015-07-01

    We present a technique for determining the scattering coefficient of epithelial tissue from diffuse reflectance measurements due to an obliquely incident Gaussian beam. This method applies the convolution form of the diffuse reflectance as determined by the corrected diffusion approximation.

  11. Visual estimation of pro-supination angle is superior to wrist or elbow angles.

    Science.gov (United States)

    Luria, Shai; Apt, Elad; Kandel, Leonid; Bdolah-Abram, Tali; Zinger, Gershon

    2015-05-01

    To examine our hypothesis that the accuracy of visual estimation, while measuring the angles of forearm, wrist and elbow, may vary between the different angles, and that this may depend on the experience of the observer. A slide show comprising of clinical photos and radiographs of different elbow, forearm and wrist angles was presented to 164 attending orthopedic surgeons, orthopedic residents and medical students who made a visual estimation of the different joints' angles. Forearm pronation was found to be estimated most accurately (mean 6.1°) while radiographs of wrist flexion (mean 12°) and photos of wrist extension (mean 16°) were estimated the least accurately. Specialists estimated angles more accurately than residents and both were more accurate than students, regardless of the estimated joint. The accuracy of visual estimation of a joint's angle depends on the specific joint viewed. Experience in the practice of orthopedic surgery (and not only upper extremity surgery) will improve the accuracy of estimation in general. Regarding the elbow, forearm and wrist, the results of our study suggest that a goniometer should be used whenever an accuracy of up to 10° is important, and for measuring wrist flexion and extension.

  12. Equivalence of oblique and frontal illumination in perspective shape from shading

    OpenAIRE

    Chow, CK; Yuen, SY

    2007-01-01

    In this paper, it is shown that any oblique illumination shape-from-shading problem under perspective projection for Lambertian reflection and a single distant light source can be converted to an equivalent frontal illumination problem by a simple nonlinear intensity transformation which is equivalent to a rectification in stereo vision. Remarkably, it involves no approximation of depth. The method is evaluated on perspective shape-from-shading involving wide range of oblique angles. © 2007 I...

  13. Oblique detonation waves stabilized in rectangular-cross-section bent tubes

    OpenAIRE

    2011-01-01

    Oblique detonation waves, which are generated by a fundamental detonation phenomenon occurring in bent tubes, may be applied to fuel combustion in high-efficiency engines such as a pulse detonation engine (PDE) and a rotating detonation engine (RDE). The present study has experimentally demonstrated that steady-state oblique detonation waves propagated stably through rectangular-cross-section bent tubes by visualizing these waves using a high-speed camera and the shadowgraph method. The obliq...

  14. Do angles of obliquity apply to 30 degrees scattered radiation from megavoltage beams?

    Science.gov (United States)

    Biggs, Peter J; Styczynski, John R

    2008-10-01

    The angle of obliquity is used in radiation shielding calculations to account for the longer path length x rays will see when obliquely incident on the protective barrier. According to the National Council on Radiation Protection and Measurements (NCRP), use of the angle of obliquity is explicitly assumed for primary radiation, so that an angle of obliquity for secondary radiation is never addressed. However, in the example section of the latest report, it specifically recommends against using an angle of obliquity for scattered radiation. To check this assumption, the existence or not of an angle of obliquity for scattered radiation has been investigated for bremsstrahlung x-ray beams of 4, 6, 10, 15, and 18 MV and for barriers consisting of concrete, lead, and steel using a Monte Carlo approach. The MCNP Monte Carlo code, v4.2C, has been used to generate scattered radiation at 30 degrees from a water phantom and incident on a secondary barrier at the same angle relative to the normal to the barrier. The barrier thickness was increased from zero to a thickness sufficient to reduce the fluence (f4 tally) to concrete (5 energies) show an average angle of obliquity of 21.7 degrees +/- 5.6 degrees , and for the first two TVLs averaged 29.7 degrees +/- 3.9 degrees . The results for the first TVL in lead (3 energies) show an average angle of obliquity of 27.7 degrees +/- 4.0 degrees , and for the first two TVLs averaged 20.5 degrees +/- 5.8 degrees . There are no data in the NCRP reports for 30 degrees scattered radiation attenuated by steel with which to make a comparison.

  15. Real-Time Speech/Music Classification With a Hierarchical Oblique Decision Tree

    Science.gov (United States)

    2008-04-01

    REAL-TIME SPEECH/ MUSIC CLASSIFICATION WITH A HIERARCHICAL OBLIQUE DECISION TREE Jun Wang, Qiong Wu, Haojiang Deng, Qin Yan Institute of Acoustics...time speech/ music classification with a hierarchical oblique decision tree. A set of discrimination features in frequency domain are selected...handle signals without discrimination and can not work properly in the existence of multimedia signals. This paper proposes a real-time speech/ music

  16. Which oblique plane is more helpful in diagnosing an anterior cruciate ligament tear?

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, J.W. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Yoon, Y.C. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of)], E-mail: ycyoon@skku.edu; Kim, Y.N. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Ahn, J.H. [Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Choe, B.K. [Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

    2009-03-15

    Aim: To evaluate the diagnostic role of additional oblique coronal and oblique sagittal magnetic resonance imaging (MRI) for an anterior cruciate ligament (ACL) tear. Materials and methods: A total of 101 patients who had undergone preoperative knee MRI examinations with orthogonal and two sets of oblique images were enrolled in the study. Two radiologists evaluated the MRI images by the use of four methods: orthogonal images only (method A); orthogonal and additional oblique coronal images (method B); orthogonal and oblique sagittal images (method C); and orthogonal images with oblique coronal and sagittal images (method D). The status of the ACL (normal or tear) was determined by consensus. The sensitivity, specificity, and accuracy for an ACL tear with the use of each method were calculated in comparison with arthroscopy as the reference standard, and values were statistically analysed using the McNemar test. The diagnostic accuracies were compared using receiver operating characteristic (ROC) analysis. Results: Arthroscopy identified 10 partial ACL tears and 30 complete ACL tears. The specificities and accuracies for methods B, C, and D were significantly higher than the specificities and accuracies for method A (p < 0.05). There was no significant difference in the sensitivity, specificity, and accuracy for methods B, C, and D. Diagnostic ability was not significantly different for each method, as determined by ROC analysis (p > 0.05). Conclusions: Additional oblique imaging for an ACL tear improved the specificity. Either of the oblique imaging methods is sufficient, and no further improvement in the diagnostic efficacy was achieved by simultaneous use.

  17. Evaluation of subjective and objective cyclodeviation following oblique muscle weakening procedures

    Directory of Open Access Journals (Sweden)

    Sharma Pradeep

    2008-01-01

    Full Text Available Purpose: To evaluate the subjective and objective cyclodeviational changes following different weakening procedures on superior and inferior oblique muscles Design: Comparative case series Materials and Methods: In a prospective institution based study, 16 cases of A pattern horizontal strabismus having superior oblique overaction were randomized to superior oblique weakening procedures: either silicon expander or translational-recession. Similarly, 20 cases of V pattern horizontal strabismus with inferior oblique overaction were randomized for inferior oblique weakening procedures: either 10 mm Fink′s recession or modified Elliot and Nankin′s anteropositioning. Cyclodeviation was assessed subjectively with the synoptophore and objectively using the fundus photograph before surgery and 3 months postoperatively. Change in cyclodeviation was measured by subjective and objective methods. The index of surgical effect (ISE was defined as the net torsional change postoperatively. Results: The difference between the extorsional change induced by the two superior oblique procedures, silicone expander (-6° and translational recession (-11.3°, was statistically significant (P=0.001. Translational recession caused more extorsional change (ISE=296% than silicone expander surgery (ISE=107%. The two inferior oblique weakening procedures, Fink′s recession (+2.5° and modified Elliot and Nankin′s anteropositioning (+4.7° produced equitable amount of intorsional shift with no statistical difference (P=0.93. Objective measurements were significantly more than the subjective measurements. Conclusions: Different weakening procedures on oblique muscles produce different changes in cyclodeviation, which persists even up to 3 months. Subjective cyclodeviation is less than the objective measurements indicating partial compensation by sensorial adaptations.

  18. Oblique low-altitude image matching using robust perspective invariant features

    Science.gov (United States)

    He, Haiqing; Du, Jing; Chen, Xiaoyong; Wang, Yuqian

    2017-01-01

    Compared with vertical photogrammtry, oblique photogrammetry is radically different for images acquired from sensor with big yaw, pitch, and roll angles. Image matching is a vital step and core problem of oblique low-altitude photogrammetric process. Among the most popular oblique images matching methods are currently SIFT/ASIFT and many affine invariant feature-based approaches, which are mainly used in computer vision, while these methods are unsuitable for requiring evenly distributed corresponding points and high efficiency simultaneously in oblique photogrammetry. In this paper, we present an oblique low-altitude images matching approach using robust perspective invariant features. Firstly, the homography matrix is estimated by a few corresponding points obtained from top pyramid images matching in several projective simulation. Then images matching are implemented by sub-pixel Harris corners and descriptors after shape perspective transforming on the basis of homography matrix. Finally, the error or gross error matched points are excluded by epipolar geometry, RANSAC algorithm and back projection constraint. Experimental results show that the proposed approach can achieve more excellent performances in oblique low-altitude images matching than the common methods, including SIFT and SURF. And the proposed approach can significantly improve the computational efficiency compared with ASIFT and Affine-SURF.

  19. Initial experience with a nuclear medicine viewing workstation

    Science.gov (United States)

    Witt, Robert M.; Burt, Robert W.

    1992-07-01

    Graphical User Interfaced (GUI) workstations are now available from commercial vendors. We recently installed a GUI workstation in our nuclear medicine reading room for exclusive use of staff and resident physicians. The system is built upon a Macintosh platform and has been available as a DELTAmanager from MedImage and more recently as an ICON V from Siemens Medical Systems. The workstation provides only display functions and connects to our existing nuclear medicine imaging system via ethernet. The system has some processing capabilities to create oblique, sagittal and coronal views from transverse tomographic views. Hard copy output is via a screen save device and a thermal color printer. The DELTAmanager replaced a MicroDELTA workstation which had both process and view functions. The mouse activated GUI has made remarkable changes to physicians'' use of the nuclear medicine viewing system. Training time to view and review studies has been reduced from hours to about 30-minutes. Generation of oblique views and display of brain and heart tomographic studies has been reduced from about 30-minutes of technician''s time to about 5-minutes of physician''s time. Overall operator functionality has been increased so that resident physicians with little prior computer experience can access all images on the image server and display pertinent patient images when consulting with other staff.

  20. Baseline coastal oblique aerial photographs collected from Pensacola, Florida, to Breton Islands, Louisiana, February 7, 2012

    Science.gov (United States)

    Morgan, Karen L.M.; Krohn, M. Dennis; Doran, Kara; Guy, Kristy K.

    2013-01-01

    The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On February 7, 2012, the USGS conducted an oblique aerial photographic survey from Pensacola, Fla., to Breton Islands, La., aboard a Piper Navajo Chieftain at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect baseline data for assessing incremental changes since the last survey, and the data can be used in the assessment of future coastal change. The photographs provided here are Joint Photographic Experts Group (JPEG) images. The photograph locations are an estimate of the position of the aircraft and do not indicate the location of the feature in the images (see the Navigation Data page). These photos document the configuration of the barrier islands and other coastal features at the time of the survey. The header of each photo is populated with time of collection, Global Positioning System (GPS) latitude, GPS longitude, GPS position (latitude and longitude), keywords, credit, artist (photographer), caption, copyright, and contact information using EXIFtools (Subino and others, 2012). Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. Table 1 provides detailed information about the assigned location, name, data, and time the photograph was taken along with links to the photograph. In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files (see the Photos and Maps page).

  1. Oblique derivative problem for general Chaplygin-Rassias equations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The present paper deals with the oblique derivative problem for general second order equations of mixed (elliptic-hyperbolic) type with the nonsmooth parabolic degenerate line K1(y)uxx+|K2(x)|uyy+a(x,y)ux+b(x, y)uy+c(x,y)u=-d(x,y) in any plane domain D with the boundary D=Γ∪L1∪L2∪L3∪L4, whereΓ(■{y>0})∈Cμ2 (0<μ<1) is a curve with the end points z=-1,1. L1, L2, L3, L4 are four characteristics with the slopes -H2(x)/H1(y), H2(x)/H1(y),-H2(x)/H1(y), H2(x)/H1(y)(H1(y)=|k1(y)|1/2, H2(x)=|K2(x)|1/2 in {y<0}) passing through the points z=x+iy=-1,0,0,1 respectively. And the boundary condition possesses the form 1/2 u/v=1/H(x,y)Re[λuz]=r(z), z∈Γ∪L1∪L4, Im[λ(z)uz]|z=zl=bl, l=1,2, u(-1)=b0, u(1)=b3, in which z1, z2 are the intersection points of L1, L2, L3, L4 respectively. The above equations can be called the general Chaplygin-Rassias equations, which include the Chaplygin-Rassias equations K1(y)(M2(x)ux)x+M1(x)(K2(y)uy)y+r(x,y)u=f(x,y), in D as their special case. The above boundary value problem includes the Tricomi problem of the Chaplygin equation: K(y)uxx+uyy=0 with the boundary condition u(z)=φ(z) onΓ∪L1∪L4 as a special case. Firstly some estimates and the existence of solutions of the corresponding boundary value problems for the degenerate elliptic and hyperbolic equations of second order are discussed. Secondly, the solvability of the Tricomi problem, the oblique derivative problem and Frankl problem for the general Chaplygin- Rassias equations are proved. The used method in this paper is different from those in other papers, because the new notations W(z)=W(x+iy)=uz=[H1(y)ux-iH2(x)uy]/2 in the elliptic domain and W(z)=W(x+jy)=uz=[H1(y)ux-jH2(x)uy]/2 in the hyperbolic domain are introduced for the first time, such that the second order equations of

  2. A Rotating Pendulum Linked by an Oblique Spring

    Institute of Scientific and Technical Information of China (English)

    CAO Qing-Jie; HAN Ning; TIAN Rui-Lan

    2011-01-01

    @@ We present a novel model which comprises a rotating pendulum linked by an oblique spring pinned to its rigid support.This model provides a cylindrical dynamical system with both smooth and discontinuous regimes depending on the value of a system parameter and also the dynamics transient relying on the coupling strength between the pendulum and the linked spring.The presented system behaves with both standard (smooth) and nonstandard (discontinuous) nonlinear dynamics of equilibrium bifurcations and the periodic patterns when it is unperturbed.Complicated resonant structures of period, quasi-period and stochastic phenomena are presented for the system with unique harmonic perturbation.The chaotic behavior of the system perturbed by both viscous-damping and external excitations is aiso demonstrated.%H'f present ;I novel model wbkh compriaes n rotating pendulum liiiknl by as oblbpie spring pinned to its rigid .support. This model provides n ryliiulncal dynamical system with both smooth and discontinuous regimes depending an the ralue of a Obtsm parameter and afao the dyaamka transient relying on the coupling strength between thependohm ?nd tiefMed spring. The presented m>1'-:I; bOami nii/I Wh standanJ (sanootij mid iHWsrondard frfi> rt.nr in no u, I imn/iucaj- rfvnamics of equilibrium MhmtWM and t&s partodlc palbtros wlien I( is uoperturbod. Omt/ifjcatcci rraonam rtrucniros of period, qiia-si-fn-rn-) mri rtedastfe pljpjioiiicua are presented for iJje s.vsteni ivitli tmfqtB! U,irmonic pemirbMiiin. The chai/tk bcAavftn ctf lln- m-I'iii perturbed by huth iriBcous-dampbig ,-wd external excitsttois is a&o Jumom,irHtnl.

  3. Differential melt scaling for oblique impacts on terrestrial planets

    Science.gov (United States)

    Abramov, Oleg; Wong, Stephanie M. Wong; Kring, David A. Kring

    2012-01-01

    Analytical estimates of melt volumes produced by a given projectile and contained in a given impact crater are derived as a function of impact velocity, impact angle, planetary gravity, target and projectile densities, and specific internal energy of melting. Applications to impact events and impact craters on the Earth, Moon, and Mars are demonstrated and discussed. The most probable oblique impact (45°) produces ∼1.6 times less melt volume than a vertical impact, and ∼1.6 and 3.7 times more melt volume than impacts with 30° and 15° trajectories, respectively. The melt volume for a particular crater diameter increases with planetary gravity, so a crater on Earth should have more melt than similar-size craters on Mars and the Moon. The melt volume for a particular projectile diameter does not depend on gravity, but has a strong dependence on impact velocity, so the melt generated by a given projectile on the Moon is significantly larger than on Mars. Higher surface temperatures and geothermal gradients increase melt production, as do lower energies of melting. Collectively, the results imply thinner central melt sheets and a smaller proportion of melt particles in impact breccias on the Moon and Mars than on Earth. These effects are illustrated in a comparison of the Chicxulub crater on Earth, linked to the Cretaceous–Tertiary mass extinction, Gusev crater on Mars, where the Mars Exploration Rover Spirit landed, and Tsiolkovsky crater on the Moon. The results are comparable to those obtained from field and spacecraft observations, other analytical expressions, and hydrocode simulations.

  4. Automatic Sky View Factor Estimation from Street View Photographs—A Big Data Approach

    Directory of Open Access Journals (Sweden)

    Jianming Liang

    2017-04-01

    Full Text Available Hemispherical (fisheye photography is a well-established approach for estimating the sky view factor (SVF. High-resolution urban models from LiDAR and oblique airborne photogrammetry can provide continuous SVF estimates over a large urban area, but such data are not always available and are difficult to acquire. Street view panoramas have become widely available in urban areas worldwide: Google Street View (GSV maintains a global network of panoramas excluding China and several other countries; Baidu Street View (BSV and Tencent Street View (TSV focus their panorama acquisition efforts within China, and have covered hundreds of cities therein. In this paper, we approach this issue from a big data perspective by presenting and validating a method for automatic estimation of SVF from massive amounts of street view photographs. Comparisons were made with SVF estimates derived from two independent sources: a LiDAR-based Digital Surface Model (DSM and an oblique airborne photogrammetry-based 3D city model (OAP3D, resulting in a correlation coefficient of 0.863 and 0.987, respectively. The comparisons demonstrated the capacity of the proposed method to provide reliable SVF estimates. Additionally, we present an application of the proposed method with about 12,000 GSV panoramas to characterize the spatial distribution of SVF over Manhattan Island in New York City. Although this is a proof-of-concept study, it has shown the potential of the proposed approach to assist urban climate and urban planning research. However, further development is needed before this approach can be finally delivered to the urban climate and urban planning communities for practical applications.

  5. Finite element modeling for predicting the contact pressure between a foam mattress and the human body in a supine position.

    Science.gov (United States)

    Lee, Wookjin; Won, Byeong Hee; Cho, Seong Wook

    2017-01-01

    In this paper, we generated finite element (FE) models to predict the contact pressure between a foam mattress and the human body in a supine position. Twenty-year-old males were used for three-dimensional scanning to produce the FE human models, which was composed of skin and muscle tissue. A linear elastic isotropic material model was used for the skin, and the Mooney-Rivlin model was used for the muscle tissue because it can effectively represent the nonlinear behavior of muscle. The contact pressure between the human model and the mattress was predicted by numerical simulation. The human models were validated by comparing the body pressure distribution obtained from the same human subject when he was lying on two different mattress types. The experimental results showed that the slope of the lower part of the mattress caused a decrease in the contact pressure at the heels, and the effect of bone structure was most pronounced in the scapula. After inserting a simple structure to function as the scapula, the contact pressure predicted by the FE human models was consistent with the experimental body pressure distribution for all body parts. These results suggest that the models proposed in this paper will be useful to researchers and designers of products related to the prevention of pressure ulcers.

  6. Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope.

    Science.gov (United States)

    Benditz, Achim; Boluki, Daniel; Weber, Markus; Zeman, Florian; Grifka, Joachim; Völlner, Florian

    2017-03-01

    Purpose To investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking. Methods MR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification. Results Global lumbar lordosis (L1-S1) was 44.99° (± 10 754) on radiographs and 47.91° (± 9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p consideration of the Sacral Slope. Fortschr Röntgenstr 2017; 189: 233 - 239.

  7. Localized Slip and Distributed Deformation in Oblique Settings: The Example of the Denali Fault System, Alaska

    Science.gov (United States)

    Vallage, A.; Deves, M.; Klinger, Y.; King, G. C. P.; Ruppert, N. A.

    2014-12-01

    Earthquakes occurring in oblique tectonic settings often partition between several faults that accommodate different components of the total motion. The 2002 Mw 7.9 Denali strike-slip earthquake, which azimuth varies by more than 50° over the 341 km total rupture length, offers a unique opportunity to look at partitioning in details, thanks to a large seismological dataset. Using a kinematic model that incorporates the obliquity of the plate-motion direction relative to the local fault azimuth, we show that the co-seismic deformation is consistent with the general northwestward displacement of the Wrangell block relative to stable North America. Hence we quantify the efficiency of the Denali fault to accommodate such oblique far field tectonic conditions by defining a coefficient of accommodation Ca, and we evaluate how much remains to be accommodated by distributed deformation off the strike-slip fault. We represent the distributed deformation using strain rosette for a catalog of 735 focal mechanisms between 1987 and 2011. We show that in oblique settings, such as in the Denali case, the aftershocks and the background seismicity are organized to accommodate the deformation that is not localized on the Denali strike-slip fault during the main earthquakes. Actually the westward increase of the obliquity increases the amount of such deformation accommodated through distributed thrust faults, leading to the westward widening of the Alaska Range. In addition we use a simple 2D boundary element elastic model to investigate the difference between geodetic data, showing a rotation of the block south of the fault, and our oblique boundary conditions. We show that it is possible to reproduce the rotation of such block while it is subjected to a northwestward oblique displacement applied on the curved Denali fault system.

  8. [Contribution of the biceps brachii and pronator teres muscles to the efforts of pronation or supination. I. Statistical work (author's transl)].

    Science.gov (United States)

    van Hoecke, J; Pérot, C; Goubel, F

    1978-03-20

    The electrical activity of the biceps brachii and pronator teres muscles is studied through the prono-supination of the forearm in some isometrical conditions (static work) with different loads and joint positions. If the pronator teres is always being active in pronation, this activity is a function of the load and of the wrist and elbow positions. The same phenomena can be observed for the biceps brachii but when in supination. From the curvilinear relationships between the integrated electrical activity and the load--observed on both muscles--some torque-angle relationships can be established for the biceps brachii which show that a bifunctional muscle seems to be characterized by a very and unique force-length relationship.

  9. Quantitative cardiovascular magnetic resonance in pregnant women: cross-sectional analysis of physiological parameters throughout pregnancy and the impact of the supine position

    Directory of Open Access Journals (Sweden)

    Moelker Adriaan

    2011-06-01

    Full Text Available Abstract Background There are physiological reasons for the effects of positioning on hemodynamic variables and cardiac dimensions related to altered intra-abdominal and intra-thoracic pressures. This problem is especially evident in pregnant women due to the additional aorto-caval compression by the enlarged uterus. The purpose of this study was to investigate the effect of postural changes on cardiac dimensions and function during mid and late pregnancy using cardiovascular magnetic resonance (CMR. Methods Healthy non-pregnant women, pregnant women at 20th week of gestation and at 32nd week of gestation without history of cardiac disease were recruited to the study and underwent CMR in supine and left lateral positions. Cardiac hemodynamic parameters and dimensions were measured and compared between both positions. Results Five non-pregnant women, 6 healthy pregnant women at mid pregnancy and 8 healthy pregnant women at late pregnancy were enrolled in the study. In the group of non-pregnant women left ventricular (LV cardiac output (CO significantly decreased by 9% (p = 0.043 and right ventricular (RV end-diastolic volume (EDV significantly increased by 5% (p = 0.043 from the supine to the left lateral position. During mid pregnancy LV ejection fraction (EF, stroke volume (SV, left atrium lateral diameter and left atrial supero-inferior diameter increased significantly from the supine position to the left lateral position: 8%, 27%, 5% and 11%, respectively (p Conclusions During pregnancy positional changes affect significantly cardiac hemodynamic parameters and dimensions. Pregnant women who need serial studies by CMR should be imaged in a consistent position. From as early as 20 weeks the left lateral position should be preferred on the supine position because it positively affects venous return, SV and CO.

  10. A comparative study of supine lying, side lying and prone positioning on oxygen saturation, in mechanically ventilated patients, in acute respiratory failure

    Directory of Open Access Journals (Sweden)

    Prajakta S. Patil

    2015-07-01

    Methods: Total 33 subjects aged between 15-73 years, 21 male and 12 female patients were selected for study from ICU, Neurological trauma unit Pune. Inclusion criteria: All subjects with respiratory failure due to different pathologies like ARDS, Pulmonary edema, pneumonia, tuberculosis, collection of fluid in pleural cavity with underlying lung collapse. Exclusion criteria: Unstable cardiac conditions, unstable fractures, unstable hemodynamic, recently operated cardiac subjects. The patients were kept in supine position, lateral and prone and vitals like BP, HR, RR and oxygen saturation with help of pulse oximeter noted just before position. Thorough ET or tracheostomy suction was done. Before turning patient if any intercostal drain present was clamped. Results: Paired t-test was used. p values for prone and bilateral side lying positions was < 0.05 showing its significance for above mentioned 3-positions. p value for supine was not < 0.05 showing its non-significance. Conclusion: The study concluded that oxygen saturation improves in prone lying and side lying position as compared to supine lying. But this improvement is quiet significant in prone position as compared to side lying. [Int J Res Med Sci 2015; 3(7.000: 1627-1631

  11. Correlation of motor control in the supine position and assistive device used for ambulation in chronic incomplete spinal cord-injured persons.

    Science.gov (United States)

    Tang, S F; Tuel, S M; McKay, W B; Dimitrijevic, M R

    1994-01-01

    Neurocontrol of movement after spinal cord injury (SCI) is often spared, but few studies have investigated the chronic incomplete SCI patient. Multichannel surface electromyography (SEMG) can describe characteristics of neurocontrol during a series of volitional and reflex events. The relationship of these neurocontrol characteristics to clinical function is incompletely described. This study, retrospectively, evaluated the relationship between neurocontrol patterns evoked by lower limb movement in the supine position and the assistive device used for ambulation in chronic, incomplete SCI persons. The records of 15 neurologically healthy (9 male, 6 female) and 36 incomplete SCI persons (27 male, 9 female) (C2-T10) were used. SEMG was recorded from both quadriceps, adductors, hamstrings, anterior tibialis and triceps surae muscles and displayed on a stripchart for analysis. SEMG patterns of activity recorded in the supine position during volitional, unilateral, multijoint (hip and knee flexion and extension) movement attempts were characterized, divided into seven groups and compared with the subjects' self-selected ambulation device (independent, cane, crutches, walker or nonambulatory). The neurocontrol patterns recorded in the supine position correlated well with the SCI subjects ambulatory assistive device. Marked decreases in motor unit output and/or loss of motor organization were found in the nonambulatory group. Coactivation of proximal muscles, poor timing of muscle activity and radiation of activity into contralateral muscles were also noted in subjects who required a walker or crutches. To a lesser degree, abnormal motor patterns were also noted in subjects who ambulated with a cane or independently.

  12. 3D reconnection due to oblique modes: a simulation of Harris current sheets

    Directory of Open Access Journals (Sweden)

    G. Lapenta

    2000-01-01

    Full Text Available Simulations in three dimensions of a Harris current sheet with mass ratio, mi/me = 180, and current sheet thickness, pi/L = 0.5, suggest the existence of a linearly unstable oblique mode, which is independent from either the drift-kink or the tearing instability. The new oblique mode causes reconnection independently from the tearing mode. During the initial linear stage, the system is unstable to the tearing mode and the drift kink mode, with growth rates that are accurately described by existing linear theories. How-ever, oblique modes are also linearly unstable, but with smaller growth rates than either the tearing or the drift-kink mode. The non-linear stage is first reached by the drift-kink mode, which alters the initial equilibrium and leads to a change in the growth rates of the tearing and oblique modes. In the non-linear stage, the resulting changes in magnetic topology are incompatible with a pure tearing mode. The oblique mode is shown to introduce a helical structure into the magnetic field lines.

  13. Observational evidence of generation mechanisms for very oblique lower band chorus using THEMIS waveform data

    Science.gov (United States)

    Gao, Xinliang; Mourenas, Didier; Li, Wen; Artemyev, Anton V.; Lu, Quanming; Tao, Xin; Wang, Shui

    2016-07-01

    Chorus waves are intense coherent whistler mode waves with frequency chirping which play a dual role in both loss and acceleration of radiation belt electrons in the Earth's magnetosphere. Although the generation of parallel chorus waves has been extensively studied by means of theory, simulations, and observations, the generation mechanism of very oblique chorus waves still remains a mystery. In this study, we have analyzed hundreds of very oblique discrete (rising or falling tone) lower band chorus events collected from 7 years of Time History of Events and Macroscale Interactions during Substorms (THEMIS) waveform data to investigate their potential generation mechanisms. Comparisons between wave normal angles directly measured onboard THEMIS in the dawn-day sector at L = 5-9 and inferred from theoretical models on the basis of measured wave characteristics (frequency sweep rate, mean frequency, and amplitude) show that these very oblique waves are more commonly generated through cyclotron resonance with anisotropic electron streams. However, a second generation mechanism via Landau resonance with low-energy electron beams seems to be also operating on the nightside at L 8.5. Moreover, very oblique lower band chorus waves with large frequency chirping rates or small magnetic field amplitudes are more likely excited via cyclotron resonance, while waves with small frequency chirping rates or large magnetic field amplitudes are preferentially generated through Landau resonance. This comprehensive statistical study provides interesting insight into the possible generation mechanisms of very oblique lower band chorus waves in the Earth's magnetosphere.

  14. An oblique muscle hematoma as a rare cause of severe abdominal pain: a case report

    Directory of Open Access Journals (Sweden)

    Shimodaira Masanori

    2013-01-01

    Full Text Available Abstract Background Abdominal wall hematomas are an uncommon cause of acute abdominal pain and are often misdiagnosed. They are more common in elderly individuals, particularly in those under anticoagulant therapy. Most abdominal wall hematomas occur in the rectus sheath, and hematomas within the oblique muscle are very rare and are poorly described in the literature. Here we report the case of an oblique muscle hematoma in a middle-aged patient who was not under anticoagulant therapy. Case presentation A 42-year-old Japanese man presented with a painful, enlarging, lateral abdominal wall mass, which appeared after playing baseball. Abdominal computed tomography and ultrasonography showed a large soft tissue mass located in the patient’s left internal oblique muscle. A diagnosis of a lateral oblique muscle hematoma was made and the patient was treated conservatively. Conclusion Physicians should consider an oblique muscle hematoma during the initial differential diagnosis of pain in the lateral abdominal wall even in the absence of anticoagulant therapy or trauma.

  15. Ice Caps and Ice Belts: The Effects of Obliquity on Ice‑Albedo Feedback

    Science.gov (United States)

    Rose, Brian E. J.; Cronin, Timothy W.; Bitz, Cecilia M.

    2017-09-01

    Planetary obliquity determines the meridional distribution of the annual mean insolation. For obliquity exceeding 55°, the weakest insolation occurs at the equator. Stable partial snow and ice cover on such a planet would be in the form of a belt about the equator rather than polar caps. An analytical model of planetary climate is used to investigate the stability of ice caps and ice belts over the widest possible range of parameters. The model is a non-dimensional diffusive Energy Balance Model, representing insolation, heat transport, and ice‑albedo feedback on a spherical planet. A complete analytical solution for any obliquity is given and validated against numerical solutions of a seasonal model in the “deep-water” regime of weak seasonal ice line migration. Multiple equilibria and unstable transitions between climate states (ice-free, Snowball, or ice cap/belt) are found over wide swaths of parameter space, including a “Large Ice-Belt Instability” and “Small Ice-Belt Instability” at high obliquity. The Snowball catastrophe is avoided at weak radiative forcing in two different scenarios: weak albedo feedback and inefficient heat transport (favoring stable partial ice cover), or efficient transport at high obliquity (favoring ice-free conditions). From speculative assumptions about distributions of planetary parameters, three-fourths to four-fifths of all planets with stable partial ice cover should be in the form of Earth-like polar caps.

  16. Inferior Oblique Muscle Weakening: Is It Possible to Quantify Its Effects on Horizontal Deviations?

    Directory of Open Access Journals (Sweden)

    Hande Taylan Sekeroglu

    2012-01-01

    Full Text Available Objective. To evaluate and quantify the effect of inferior oblique muscle weakening on horizontal deviations. Methods. The medical files of patients who had undergone an inferior oblique weakening as a single procedure were all reviewed. The main measures were the type of inferior oblique overaction (IOOA, pre- and postoperative amount of IOOA, and horizontal deviations in primary position. Results. The study was conducted with 66 patients (30 males, 36 females. The median age was 11 years (1–49. Of the 66 patients, 30 (45.5% had primary and 36 (54.5% had secondary IOOA. The most common procedure was inferior oblique anteriorization in 32 patients (48.5%. The mean postoperative horizontal and vertical deviations and the amount of IOOA were decreased postoperatively ( for all. The median amount of correction of horizontal near and distance deviations was (0–20. The preoperative amount of IOOA, the presence of fourth nerve palsy, and the type of the weakening procedure had no significant effect on the amount of correction of horizontal deviations. Conclusion. The inferior oblique weakening procedures have secondary effects and warrant reduction of horizontal deviations in varying degrees. This should be borne in mind in planning a simultaneous horizontal muscle surgery and setting the surgical amount.

  17. DMSA SPECT imaging using oblique reconstruction in a paediatric population - benefits and technical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, G.; Ford, M.; Crisp, J.; Bernard, E.; Howman-Giles, R. [The New Childrens Hospital, Westmead, NSW, (Australia). Department of Nuclear Medicine

    1997-09-01

    Full text: DMSA renal scans are frequently requested for the diagnosis and follow-up of acute pyelonephritis and cortical scarring. This study was designed to:- 1. evaluate oblique reconstruction of DMSA SPECT over standard plane reconstruction and planar imaging; and 2. report on the technical aspects important in obtaining high quality DMSA SPECT, particularly in neonates. Over seven months, 210/231 (91 %) of DMSA scans were performed with SPECT on children from age nine days to 16 years, the median age being 2.5 years. 65 patients (31 %) were under one year and 39 (18%) were under six months. Planar and SPECT imaging with standard plane reconstruction and oblique reorientation was performed on the Siemens triple-headed gamma camera. High quality SPECT images were obtained on the smallest babies using a paediatric palette, and were of comparable quality to those of older children. At the time of reporting, the nuclear medicine physician assessed the diagnostic value of the three types of date presented: (1) planar images; (2) standard plane SPECT reconstruction; and (3) oblique SPECT reconstruction. Cortical defects were identified separately for upper, middle and lower poles. Three physicians concluded that high quality SPECT is superior to planar images when assessing the renal cortex. In addition, oblique reorientation is superior to standard reconstruction, particularly at the upper and lower poles. SPECT is now performed routinely on patients of all ages, and the oblique sagittal and coronal reorientation is now used in place of the standard reconstruction.

  18. Remote viewing.

    Science.gov (United States)

    Scott, C

    1988-04-15

    Remote viewing is the supposed faculty which enables a percipient, sited in a closed room, to describe the perceptions of a remote agent visiting an unknown target site. To provide convincing demonstration of such a faculty poses a range of experimental and practical problems, especially if feedback to the percipient is allowed after each trial. The precautions needed are elaborate and troublesome; many potential loopholes have to be plugged and there will be strong temptations to relax standards, requiring exceptional discipline and dedication by the experimenters. Most reports of remote viewing experiments are rather superficial and do not permit assessment of the experimental procedures with confidence; in many cases there is clear evidence of particular loopholes left unclosed. Any serious appraisal of the evidence would have to go beyond the reports. Meanwhile the published evidence is far from compelling, and certainly insufficient to justify overthrow of well-established scientific principles.

  19. Association between computed tomography-evaluated lumbar lordosis and features of spinal degeneration, evaluated in supine position.

    Science.gov (United States)

    Kalichman, Leonid; Li, Ling; Hunter, David J; Been, Ella

    2011-04-01

    Few studies have directly evaluated the association of lumbar lordosis and segmental wedging of the vertebral bodies and intervertebral discs with the prevalence of spinal degenerative features. To evaluate the association of computed tomography (CT)-evaluated lumbar lordosis as well as segmental wedging of the vertebral bodies and that of the intervertebral discs with various spinal degenerative features. This cross-sectional study was a nested project to the Framingham Heart Study. A random consecutive subset of 191 participants chosen from the 3,590 participants enrolled in the Framingham Heart Study who underwent multidetector CT to assess aortic calcification. Dichotomous variables indicating the presence of intervertebral disc narrowing, facet joint osteoarthritis, spondylolysis, spondylolisthesis and spinal stenosis, and density (in Hounsfield units) of multifidus and erector spinae muscles were evaluated on supine CT, as well as the lordosis angle (LA) and the wedging of the vertebral bodies and intervertebral discs. The sum of vertebral bodies wedging (ΣB) and sum of intervertebral discs wedging (ΣD) were used in the analyses. Mean values (±standard deviation [SD]) of LA, ΣB, and ΣD were calculated in males and females and compared using the t test. Mean values (±SD) of LA, ΣB, and ΣD in four age groups (Lordosis angle was slightly lower than the normal range for standing individuals, and no difference was found between males and females (p=.4107). However, the sex differences in sum of vertebral bodies wedging (ΣB) and sum of intervertebral discs wedging (ΣD) were statistically significant (.0001 and .001, respectively). Females exhibit more dorsal wedging of the vertebral bodies and less dorsal wedging of the intervertebral discs than do males. All these parameters showed no association (p>.05) with increasing age. Lordosis angle showed statistically significant association with the presence of spondylolysis (odds ratio [95% confidence interval

  20. SU-E-J-21: Setup Variability of Colorectal Cancer Patients Treated in the Prone Position and Dosimetric Comparison with the Supine Position

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A; Foster, J; Chu, W; Karotki, A [Sunnybrook Health Sciences Centre/Odette Cancer Centre, Toronto, Ontario (Canada)

    2015-06-15

    Purpose: Many cancer centers treat colorectal patients in the prone position on a belly board to minimize dose to the small bowel. That may potentially Result in patient setup instability with corresponding impact on dose delivery accuracy for highly conformal techniques such as IMRT/VMAT. Two aims of this work are 1) to investigate setup accuracy of rectum patients treated in the prone position on a belly board using CBCT and 2) to evaluate dosimetric impact on bladder and small bowel of treating rectum patients in supine vs. prone position. Methods: For the setup accuracy study, 10 patients were selected. Weekly CBCTs were acquired and matched to bone. The CBCT-determined shifts were recorded. For the dosimetric study, 7 prone-setup patients and 7 supine-setup patients were randomly selected from our clinical database. Various clinically relevant dose volume histogram values were recorded for the small bowel and bladder. Results: The CBCT-determined rotational shifts had a wide variation. For the dataset acquired at the time of this writing, the ranges of rotational setup errors for pitch, roll, and yaw were [−3.6° 4.7°], [−4.3° 3.2°], and [−1.4° 1.4°]. For the dosimetric study: the small bowel V(45Gy) and mean dose for the prone position was 5.6±12.1% and 18.4±6.2Gy (ranges indicate standard deviations); for the supine position the corresponding dose values were 12.9±15.8% and 24.7±8.8Gy. For the bladder, the V(30Gy) and mean dose for prone position were 68.7±12.7% and 38.4±3.3Gy; for supine position these dose values were 77.1±13.7% and 40.7±3.1Gy. Conclusion: There is evidence of significant rotational instability in the prone position. The OAR dosimetry study indicates that there are some patients that may still benefit from the prone position, though many patients can be safely treated supine.

  1. Assessment of Cardiac Device Position on Supine Chest Radiograph in the ICU: Introduction and Applicability of the Aortic Valve Location Ratio.

    Science.gov (United States)

    Ouweneel, Dagmar M; Sjauw, Krischan D; Wiegerinck, Esther M A; Hirsch, Alexander; Baan, Jan; de Mol, Bas A J M; Lagrand, Wim K; Planken, R Nils; Henriques, José P S

    2016-10-01

    The use of intracardiac assist devices is expanding, and correct position of these devices is required for optimal functioning. The aortic valve is an important landmark for positioning of those devices. It would be of great value if the device position could be easily monitored on plain supine chest radiograph in the ICU. We introduce a ratio-based tool for determination of the aortic valve location on plain supine chest radiograph images, which can be used to evaluate intracardiac device position. Retrospective observational study. Large academic medical center. Patients admitted to the ICU and supported by an intracardiac assist device. We developed a ratio to determine the aortic valve location on supine chest radiograph images. This ratio is used to assess the position of a cardiac assist device and is compared with echocardiographic findings. Supine anterior-posterior chest radiographs of patients with an aortic valve prosthesis (n = 473) were analyzed to determine the location of the aortic valve. We calculated several ratios with the potential to determine the position of the aortic valve. The aortic valve location ratio, defined as the distance between the carina and the aortic valve, divided by the thoracic width, was found to be the best performing ratio. The aortic valve location ratio determines the location of the aortic valve caudal to the carina, at a distance of 0.25 ± 0.05 times the thoracic width for male patients and 0.28 ± 0.05 times the thoracic width for female patients. The aortic valve location ratio was validated using CT images of patients with angina pectoris without known valvular disease (n = 95). There was a good correlation between cardiac device position (Impella) assessed with the aortic valve location ratio and with echocardiography (n = 53). The aortic valve location ratio enables accurate and reproducible localization of the aortic valve on supine chest radiograph. This tool is easily applicable and can be used for

  2. Collisional effects on the oblique instability in relativistic beam-plasma interactions

    Science.gov (United States)

    Hao, B.; Ding, W. J.; Sheng, Z. M.; Ren, C.; Kong, X.; Mu, J.; Zhang, J.

    2012-07-01

    The general oblique instability for a relativistic electron beam propagating through a warm and resistive plasma is investigated fully kinetically by a variable rotation method. Analysis shows that the electrostatic part of the oblique instability is attenuated and eventually stabilized by collisional effects. However, the electromagnetic part of the oblique instability (EMOI) is enhanced. Since the current-filamentation instability as a special case of the EMOI has a larger growth rate, it becomes dominant in the collisional case as shown in our two-dimensional particle-in-cell simulations. While the beam diverges in the collisionless case, it can become magnetically collimated in the collisional case due to stabilization of the electrostatic instabilities when the initial beam spreading angle is less than certain magnitude such as a dozen degrees.

  3. Phased array ultrasonic inspection method for homogeneous tube inspection over a wide oblique angle range

    Science.gov (United States)

    Lepage, Benoit; Painchaud-April, Guillaume

    2017-02-01

    As seamless tube manufacturers push quality requirements for their products, automated phased array Rotating Tube Inspection Systems (RTIS) are now required to provide continuous NDE detection performances over a wide angular range of oblique flaws. One major impact of this new reality is a paradigm shift for the calibration method use. This change is driven by the requirement to meet homogeneous detection over broad oblique flaw angle intervals, whereas standard practice only requires calibration at specific discrete angles. This paper presents an innovative method specifically designed to obtain high productivity and homogeneous inspection measurements over an oblique flaw range extending from -45 to 45 degrees. Experimental results from the application of the method on various tubes presenting multiple artificial flaws support the quantitative performance evaluation.

  4. A Two-Fluid Study of Oblique Tearing Modes in a Force-Free Current Sheet

    CERN Document Server

    Akcay, Cihan; Lukin, Vyacheslav S; Liu, Yi-Hsin

    2016-01-01

    Kinetic simulations have demonstrated that three-dimensional reconnection in collisionless regimes proceeds through the formation and interaction of magnetic flux ropes, which are generated due to the growth of tearing instabilities at multiple resonance surfaces. Since kinetic simulations are intrinsically expensive, it is desirable to explore the feasibility of reduced two-fluid models to capture this complex evolution, particularly, in the strong guide field regime, where two-fluid models are better justified. With this goal in mind, this paper compares the evolution of the collisionless tearing instability in a force-free current sheet with a two-fluid model and fully kinetic simulations. Our results indicate that the most unstable modes are oblique for guide fields larger than the reconnecting field, in agreement with the kinetic results. The standard two-fluid tearing theory is extended to address the tearing instability at oblique angles. The resulting theory yields a flat oblique spectrum and underest...

  5. Oblique frequency domain interferometry measurements using the middle and upper atmosphere radar

    Science.gov (United States)

    Palmer, R. D.; Fukao, S.; Larsen, M. F.; Yamamoto, M.; Tsuda, T.; Kato, S.

    1992-09-01

    First results are presented from oblique frequency domain interferometry (FDI) measurements conducted using the middle and upper atmosphere radar in Japan in October 1990. Using the idea of Doppler sorting, an equation is derived which shows a parabolic variation of the oblique FDI cross-spectral phase as a function of Doppler velocity. However, because of the small range of Doppler velocities observed with the measured cross spectra, the phase has an approximate linear variation; that is, the cross spectra sample only a small portion of the parabolic structure and are therefore approximately linear and are shown to follow the model closely. Using the oblique FDI configuration, a comparison is drawn between simultaneous measurements of signal-to-noise ratio, coherence, three-dimensional wind, and profiles of FDI cross spectra. We find that the regions that exhibit a well-defined scattering layer correspond to those regions of high aspect sensitivity. An explanation is suggested based on the anisotropy of the turbulence.

  6. Frequency variations of the earth's obliquity and the 100-kyr ice-age cycles

    Science.gov (United States)

    Liu, Han-Shou

    1992-01-01

    Changes in the earth's climate are induced by variations in the earth's orbital parameters which modulate the seasonal distribution of solar radiation. Periodicities in the geological climate record with cycles of 100, 41, and 23 kyr have been linked with changes in obliquity, eccentricity, and precession of the equinoxes. The effect of variations of eccentricity during a 100 kyr period is weak relative to the signals from obliquity and precession variations and it may therefore be expected that the 100 kyr signal in the climate record would be of low intensity. However, this signal dominates the climate record and internal nonlinear processes within the climate system have previously been proposed to account for this fact. The author shows that variations in the frequency of the obliquity cycle can give rise to strong 100-kyr forcing of climate.

  7. Observation on Therapeutic Effect of Oblique Puncture plus Plucking Manual Technique for Fatigue Periostitis of Tibia

    Institute of Scientific and Technical Information of China (English)

    JI Jian-you; JI Jian-li; XU Yao

    2007-01-01

    To observe the clinical effect of oblique puncture plus plucking manual technique for fatigue periositis of tibia.Methods:60 cases of the patients with fatigue Deriostitisof tibia were randomly divided into the treatment group of 30 cases treated by oblique puncture plus plucking manual technique,and the control group of 30 cases treated by ultra short wave.Resuits:The curative rate was 60.0% in the treatment group and 20.0% in the control group.and the total effective rate was 93.3% and 70.O% respectively.The therapeutic effect was better in the treatment group than in the control group (P<0.05).Conclusion:Oblique puncture plus plucking manual technique has a better therapeutic effect for fatigue periostitis of tibia.

  8. Oblique and Herringbone Buckling Analysis of Steel Strip by Spline FEM

    Institute of Scientific and Technical Information of China (English)

    QIN Jian; ZHANG Qing-dong; HUANG Ke-fu

    2011-01-01

    The tilted waves in steel strip during rolling and leveling of sheet metal can be classified into two different types of buckling, oblique and herringbone buckling, respectively. Numerical considerations of oblique and herringbone buckling phenomena are dealt with by the spline finite element method (FEM). It is pointed out that the shear stress due to residual strains caused by the rolling process or applied non-uniform loading is the main reason of oblique and herringbone buckle. According to the analysis of stress distribution in plane, the appropriate initial strain patterns are adopted and the corresponding buckling modes are calculated by the spline FEM. The developed numerical model provides an estimation of buckling critical load and wave configuration.

  9. Coeval emplacement and orogen-parallel transport of gold in oblique convergent orogens

    Science.gov (United States)

    Upton, Phaedra; Craw, Dave

    2016-12-01

    Varying amounts of gold mineralisation is occurring in all young and active collisional mountain belts. Concurrently, these syn-orogenic hydrothermal deposits are being eroded and transported to form placer deposits. Local extension occurs in convergent orogens, especially oblique orogens, and facilitates emplacement of syn-orogenic gold-bearing deposits with or without associated magmatism. Numerical modelling has shown that extension results from directional variations in movement rates along the rock transport trajectory during convergence, and is most pronounced for highly oblique convergence with strong crustal rheology. On-going uplift during orogenesis exposes gold deposits to erosion, transport, and localised placer concentration. Drainage patterns in variably oblique convergent orogenic belts typically have an orogen-parallel or sub-parallel component; the details of which varies with convergence obliquity and the vagaries of underlying geological controls. This leads to lateral transport of eroded syn-orogenic gold on a range of scales, up to > 100 km. The presence of inherited crustal blocks with contrasting rheology in oblique orogenic collision zones can cause perturbations in drainage patterns, but numerical modelling suggests that orogen-parallel drainage is still a persistent and robust feature. The presence of an inherited block of weak crust enhances the orogen-parallel drainage by imposition of localised subsidence zones elongated along a plate boundary. Evolution and reorientation of orogen-parallel drainage can sever links between gold placer deposits and their syn-orogenic sources. Many of these modelled features of syn-orogenic gold emplacement and varying amounts of orogen-parallel detrital gold transport can be recognised in the Miocene to Recent New Zealand oblique convergent orogen. These processes contribute little gold to major placer goldfields, which require more long-term recycling and placer gold concentration. Most eroded syn

  10. Generalized and exact solutions for oblique shock waves of real gases with application to real air

    Science.gov (United States)

    Kouremenos, D. A.; Antonopoulos, K. A.

    1989-12-01

    The present work presents a generalized method for calculating oblique shock waves of real gases, based on the Redlich-Kwong (1949) equation of state. Also described is an exact method applicable when the exact equation of state and enthalpy function of a real gas are available. Application of the generalized and the exact methods in the case of real air showed that the former is very accurate and at least twenty times faster than the latter. An additional contribution of the study is the derivation of real gas oblique shock wave equations, which are of the same algebraic form as the well known ideal gas normal shock wave relations.

  11. In situ measurements of the oblique incidence sound absorption coefficient for finite sized absorbers

    DEFF Research Database (Denmark)

    Ottink, Marco; Brunskog, Jonas; Jeong, Cheol-Ho

    2016-01-01

    absorbers at oblique incidence in situ. Due to the edge diffraction effect, oblique incidence methods considering an infinite sample fail to measure the absorption coefficient at large incidence angles of finite samples. This paper aims for the development of a measurement method that accounts...... for the finiteness of the absorber. A sound field model, which accounts for scattering from the finite absorber edges, assuming plane wave incidence is derived. A significant influence of the finiteness on the radiation impedance and the corresponding absorption coefficient is found. A finite surface method, which...

  12. Effect of oblique force source induced by laser ablation on ultrasonic generation.

    Science.gov (United States)

    Guo, Yuning; Yang, Dexing; Chang, Ying; Gao, Wei

    2014-01-13

    The effect of asymmetry caused by oblique line-shaped laser ablation on the generation of ultrasonic waves in metal, especially the effect of transverse component of the ablation force source on the ultrasonic waves is analyzed. Due to the oblique force source, the displacements of shear wave increase obviously by the enhanced shear force, the energy concentration area of longitudinal wave deflects to the small range centered on the incident direction while that of shear wave is approximately perpendicular to incident direction. In addition, surface wave enhances in the direction of transverse power flow. Furthermore, some ultrasonic characteristics under vortex laser ablation condition are inferred.

  13. In situ measurements of the oblique incidence sound absorption coefficient for finite sized absorbers

    DEFF Research Database (Denmark)

    Ottink, Marco; Brunskog, Jonas; Jeong, Cheol-Ho

    2016-01-01

    absorbers at oblique incidence in situ. Due to the edge diffraction effect, oblique incidence methods considering an infinite sample fail to measure the absorption coefficient at large incidence angles of finite samples. This paper aims for the development of a measurement method that accounts...... for the finiteness of the absorber. A sound field model, which accounts for scattering from the finite absorber edges, assuming plane wave incidence is derived. A significant influence of the finiteness on the radiation impedance and the corresponding absorption coefficient is found. A finite surface method, which...

  14. Three-dimensional oblique water-entry problems at small deadrise angles

    KAUST Repository

    Moore, M. R.

    2012-09-19

    This paper extends Wagner theory for the ideal, incompressible normal impact of rigid bodies that are nearly parallel to the surface of a liquid half-space. The impactors considered are three-dimensional and have an oblique impact velocity. A formulation in terms of the displacement potential is used to reveal the relationship between the oblique and corresponding normal impact solutions. In the case of axisymmetric impactors, several geometries are considered in which singularities develop in the boundary of the effective wetted region. We present the corresponding pressure profiles and models for the splash sheets. © 2012 Cambridge University Press.

  15. Hexagonally ordered nanodots: Result of substrate rotation during oblique incidence low energy IBS

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Debasree, E-mail: debasree.chowdhury@saha.ac.in; Ghose, Debabrata, E-mail: debasree.chowdhury@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India)

    2014-04-24

    The anisotropic regular patterns are often results during oblique incidence ion beam sputtering (IBS). Simultaneous substrate rotation (SR) during IBS can suppress surface roughening and removes anisotropic nature of surface pattern. Here, the evolution of Si surface morphology as result of with and without SR is studied during oblique incidence low energy Ar{sup +} sputtering. Resultant topography shows smooth surface to hexagonally ordered nanodots at different rotating conditions. Interestingly, surface roughness exhibits non-monotonic dependence on rotation frequency. The underlying mechanism for dot formation can be described within the framework of isotropic DKS equation.

  16. Activation of the vastus medialis oblique and vastus lateralis muscles in asymptomatic subjects during the sit-to-stand procedure.

    Science.gov (United States)

    Choi, Boram

    2015-03-01

    [Purpose] The purpose of this study was to examine the vastus medialis oblique to vastus lateralis ratio in two pelvic tilt positions while performing the sit-to-stand task. [Subjects and Methods] Activation of the vastus medialis oblique and the vastus lateralis muscles of 46 healthy subjects (25 males, 21 females) were recorded by surface electromyography during the STS task with anterior pelvic tilt (sit with thoracolumbar spine extended and pelvis in an anterior tilt) and neutral pelvic tilt (sit with thoracolumbar spine relaxed and pelvis in the neutral tilt position) positions. Changes in vastus medialis oblique, vastus lateralis activation and the vastus medialis oblique/vastus lateralis ratio were analyzed. [Results] Vastus medialis oblique and vastus lateralis muscle activation significantly increased in neutral pelvic tilt position, but the vastus medialis oblique/vastus lateralis ratio was not statistically different. [Conclusion] The sit-to-stand procedure with neutral pelvic tilt position increased activation of the vastus medialis oblique and vastus lateralis, usefully strengthening the quadriceps, but did not selectively activate the vastus medialis oblique muscle.

  17. Acute abdominal pain in children: usefulness of three-view abdominal radiographs in the emergency department.

    Science.gov (United States)

    He, Lulu; Park, Ellen; Vachhani, Neil; Vogelius, Esben; Thupili, Chakradhar; Udayasankar, Unni

    2016-10-01

    Diagnostic imaging is often an integral component in the workup of a pediatric patient with acute abdominal pain. The purpose of this study was to compare the diagnostic value of a three-view acute abdominal series (AAS) with that of a single supine view (SSV) in children with acute abdominal pain. All subjects aged ≤18 years that underwent an emergency three-view AAS examination for acute abdominal pain at a single urban hospital system were included. Retrospective evaluation of radiological diagnosis, number of radiological images, further imaging, management, and clinical outcomes was performed. "Positive" AAS studies were compared with corresponding SSV images for direct comparison of diagnostic value. Standard nonparametric statistical evaluation was performed. Five hundred forty-one AAS studies were included in the study. Greater than three radiographs were acquired in 29 % (153/541) of the subjects. Two hundred ninety-nine out of 541 AAS studies included a technically adequate SSV of the abdomen and pelvis. Most AAS examinations were categorized as negative (n = 485; 90 %). Of the 56 examinations initially classified as positive, there was no significant statistical difference between diagnostic accuracy between the AAS and SSV on retrospective evaluation. For pediatric subjects with nontraumatic acute abdominal pain, the yield of conventional radiographic study is exceedingly low. If required, a technically adequate single supine anteroposterior (AP) view of the abdomen and pelvis is sufficient for initial radiographic evaluation while reducing unnecessary radiation exposure to the patient.

  18. Effects of a robot-assisted training of grasp and pronation/supination in chronic stroke: a pilot study

    Directory of Open Access Journals (Sweden)

    Lambercy Olivier

    2011-11-01

    Full Text Available Abstract Background Rehabilitation of hand function is challenging, and only few studies have investigated robot-assisted rehabilitation focusing on distal joints of the upper limb. This paper investigates the feasibility of using the HapticKnob, a table-top end-effector device, for robot-assisted rehabilitation of grasping and forearm pronation/supination, two important functions for activities of daily living involving the hand, and which are often impaired in chronic stroke patients. It evaluates the effectiveness of this device for improving hand function and the transfer of improvement to arm function. Methods A single group of fifteen chronic stroke patients with impaired arm and hand functions (Fugl-Meyer motor assessment scale (FM 10-45/66 participated in a 6-week 3-hours/week rehabilitation program with the HapticKnob. Outcome measures consisted primarily of the FM and Motricity Index (MI and their respective subsections related to distal and proximal arm function, and were assessed at the beginning, end of treatment and in a 6-weeks follow-up. Results Thirteen subjects successfully completed robot-assisted therapy, with significantly improved hand and arm motor functions, demonstrated by an average 3.00 points increase on the FM and 4.55 on the MI at the completion of the therapy (4.85 FM and 6.84 MI six weeks post-therapy. Improvements were observed both in distal and proximal components of the clinical scales at the completion of the study (2.00 FM wrist/hand, 2.55 FM shoulder/elbow, 2.23 MI hand and 4.23 MI shoulder/elbow. In addition, improvements in hand function were observed, as measured by the Motor Assessment Scale, grip force, and a decrease in arm muscle spasticity. These results were confirmed by motion data collected by the robot. Conclusions The results of this study show the feasibility of this robot-assisted therapy with patients presenting a large range of impairment levels. A significant homogeneous improvement in

  19. Persistent superior oblique paresis as a manifestation of familial periodic cerebellar ataxia.

    OpenAIRE

    Bain, P.G.; Larkin, G. B.; Calver, D M; O'Brien, M D

    1991-01-01

    A brother and sister complained of persistent diplopia due to superior oblique palsies. The cause of their symptoms became apparent when they were diagnosed as having familial periodic cerebellar ataxia (FPCA), a rare autosomal dominant condition. Oral acetazolamide (250 mg twice daily) not only prevented all the periodic symptoms but also relieved their diplopia, which had been present between attacks.

  20. Investigation of magnetic anisotropy and role of underlayer in obliquely sputtered metallic thin films

    NARCIS (Netherlands)

    Lisfi, A.; Nguyen, L.T.; Lodder, J.C.; Williams, C.M.

    2004-01-01

    Co and CoNi films have been obliquely sputtered on polyethylene terephthalate (PET) with and without Cr underlayer. The spin-reorientation observed in films directly deposited on PET is related to the low magnetocrystalline anisotropy of Co (FCC) and change in microstructure from columns to elongate

  1. A two-fluid study of oblique tearing modes in a force-free current sheet

    Energy Technology Data Exchange (ETDEWEB)

    Akçay, Cihan, E-mail: akcay@lanl.gov; Daughton, William [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lukin, Vyacheslav S. [National Science Foundation, Arlington, Virginia 22230 (United States); Liu, Yi-Hsin [NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

    2016-01-15

    Kinetic simulations have demonstrated that three-dimensional reconnection in collisionless regimes proceeds through the formation and interaction of magnetic flux ropes, which are generated due to the growth of tearing instabilities at multiple resonance surfaces. Since kinetic simulations are intrinsically expensive, it is desirable to explore the feasibility of reduced two-fluid models to capture this complex evolution, particularly, in the strong guide field regime, where two-fluid models are better justified. With this goal in mind, this paper compares the evolution of the collisionless tearing instability in a force-free current sheet with a two-fluid model and fully kinetic simulations. Our results indicate that the most unstable modes are oblique for guide fields larger than the reconnecting field, in agreement with the kinetic results. The standard two-fluid tearing theory is extended to address the tearing instability at oblique angles. The resulting theory yields a flat oblique spectrum and underestimates the growth of oblique modes in a similar manner to kinetic theory relative to kinetic simulations.

  2. Backward stochastic differential equations with oblique reflection and local Lipschitz drift

    Directory of Open Access Journals (Sweden)

    Auguste Aman

    2003-01-01

    Full Text Available We consider reflected backward stochastic differential equations with time and space dependent coefficients in an orthant, and with oblique reflection. Existence and uniqueness of solution are established assuming local Lipschitz continuity of the drift, Lipschitz continuity and uniform spectral radius conditions on the reflection matrix.

  3. Evaluation of macular thickness change after inferior oblique muscle recession surgery

    Directory of Open Access Journals (Sweden)

    Ece Turan-Vural

    2014-01-01

    Full Text Available Purpose: This study aimed to evaluate the changes in macular thickness following inferior oblique muscle recession surgery. Materials and Methods: Thirty-eight eyes from 21 patients undergoing ocular muscle surgery were included. Patients were grouped into three groups based on the type of surgical intervention: Group I (n = 12, inferior oblique recession surgery alone; Group II (n = 12, inferior oblique plus horizontal muscle surgery; Group III (n = 14, horizontal muscle surgery alone. Each eye was scanned using the optical coherence tomography (OCT device preoperatively and on the first postoperative day to measure macular thickness. Results: Following surgery, a significant increase in foveal thickness occurred in Group I (P < 0.05 and Group II (P < 0.01. In addition, a statistically significant difference was observed between the groups with regard to the increase in foveal thickness (P = 0.016, with significantly lower changes in Group III. Conclusion: Our findings suggested that inferior oblique muscle recession surgery is associated with an increase in macular thickness.

  4. OBLIQUITIES OF HOT JUPITER HOST STARS: EVIDENCE FOR TIDAL INTERACTIONS AND PRIMORDIAL MISALIGNMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Simon; Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Johnson, John A. [Department of Astrophysics, California Institute of Technology, MC249-17, Pasadena, CA 91125 (United States); Howard, Andrew W.; Marcy, Geoffrey W. [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Butler, R. Paul [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Arriagada, Pamela [Department of Astronomy, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B. [The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Hirano, Teruyuki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Bakos, Gaspar; Hartman, Joel D. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544 (United States)

    2012-09-20

    We provide evidence that the obliquities of stars with close-in giant planets were initially nearly random, and that the low obliquities that are often observed are a consequence of star-planet tidal interactions. The evidence is based on 14 new measurements of the Rossiter-McLaughlin effect (for the systems HAT-P-6, HAT-P-7, HAT-P-16, HAT-P-24, HAT-P-32, HAT-P-34, WASP-12, WASP-16, WASP-18, WASP-19, WASP-26, WASP-31, Gl 436, and Kepler-8), as well as a critical review of previous observations. The low-obliquity (well-aligned) systems are those for which the expected tidal timescale is short, and likewise the high-obliquity (misaligned and retrograde) systems are those for which the expected timescale is long. At face value, this finding indicates that the origin of hot Jupiters involves dynamical interactions like planet-planet interactions or the Kozai effect that tilt their orbits rather than inspiraling due to interaction with a protoplanetary disk. We discuss the status of this hypothesis and the observations that are needed for a more definitive conclusion.

  5. Intrinsic carpal ligaments on MR and multidetector CT arthrography: comparison of axial and axial oblique planes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ryan K.L.; Griffith, James F.; Ng, Alex W.H.; Law, Eric K.C. [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince Of Wales Hospital, Hong Kong (China); Tse, W.L.; Wong, Clara W.Y.; Ho, P.C. [The Chinese University of Hong Kong, Department of Orthopedics and Traumatology, Prince Of Wales Hospital, Hong Kong (China)

    2017-03-15

    To compare axial and oblique axial planes on MR arthrography (MRA) and multidetector CT arthrography (CTA) to evaluate dorsal and volar parts of scapholunate (SLIL) and lunotriquetral interosseous (LTIL) ligaments. Nine cadaveric wrists of five male subjects were studied. The visibility of dorsal and volar parts of the SLIL and LTIL was graded semi-quantitatively (good, intermediate, poor) on MRA and CTA. The presence of a ligament tear was determined on arthrosocopy and sensitivity, specificity and accuracy of tear detection were calculated. Oblique axial imaging was particularly useful for delineating dorsal and volar parts of the LTIL on MRA with overall 'good' visibility increased from 11 % to 78 %. The accuracy of MRA and CTA in revealing SLIL and LTIL tear was higher using the oblique axial plane. The overall accuracy for detecting SLIL tear on CTA improved from 94 % to 100 % and from 89 % to 94 % on MRA; the overall accuracy of detecting LTIL tear on CTA improved from 89 % to 100 % and from 72 % to 89 % on MRA Oblique axial imaging during CT and MR arthrography improves detection of tears in the dorsal and volar parts of both SLIL and LTIL. (orig.)

  6. Orthogonal versus Oblique Factor Rotation: A Review of the Literature regarding the Pros and Cons.

    Science.gov (United States)

    Kieffer, Kevin M.

    Factor analysis has been characterized as being at the heart of the score validation process. In virtually all applications of exploratory factor analysis, factors are rotated to better meet L. Thurstone's simple structure criteria. Two major rotation strategies are available: orthogonal and oblique. This paper reviews the numerous rotation…

  7. Multiple Climate States of Habitable Exoplanets: The Role of Obliquity and Irradiance

    Science.gov (United States)

    Kilic, C.; Raible, C. C.; Stocker, T. F.

    2017-08-01

    Stable, steady climate states on an Earth-size planet with no continents are determined as a function of the tilt of the planet’s rotation axis (obliquity) and stellar irradiance. Using a general circulation model of the atmosphere coupled to a slab ocean and a thermodynamic sea ice model, two states, the Aquaplanet and the Cryoplanet, are found for high and low stellar irradiance, respectively. In addition, four stable states with seasonally and perennially open water are discovered if comprehensively exploring a parameter space of obliquity from 0° to 90° and stellar irradiance from 70% to 135% of the present-day solar constant. Within 11% of today’s solar irradiance, we find a rich structure of stable states that extends the area of habitability considerably. For the same set of parameters, different stable states result if simulations are initialized from an aquaplanet or a cryoplanet state. This demonstrates the possibility of multiple equilibria, hysteresis, and potentially rapid climate change in response to small changes in the orbital parameters. The dynamics of the atmosphere of an aquaplanet or a cryoplanet state is investigated for similar values of obliquity and stellar irradiance. The atmospheric circulation substantially differs in the two states owing to the relative strength of the primary drivers of the meridional transport of heat and momentum. At 90° obliquity and present-day solar constant, the atmospheric dynamics of an Aquaplanet state and one with an equatorial ice cover is analyzed.

  8. Asteroseismic Determination of Obliquities of the Exoplanet Systems Kepler-50 and Kepler-65

    DEFF Research Database (Denmark)

    Chaplin, W. J.; Sanchis-Ojeda, R.; Campante, T. L.

    2013-01-01

    Results on the obliquity of exoplanet host stars - the angle between the stellar spin axis and the planetary orbital axis - provide important diagnostic information for theories describing planetary formation. Here we present the first application of asteroseismology to the problem of stellar...

  9. Detection of protein microarrays by oblique-incidence reflectivity difference technique

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Biological microarrays with different proteins and different protein concentrations are detected without external labeling by an oblique-incidence reflectivity difference (OIRD) technique. The initial experiment results reveal that the intensities of OIRD signals can distinguish the different proteins and concentrations of protein. The OIRD technique promises feasible applications to life sciences for label-free and high-throughput detection.

  10. Transfer Matrix for Obliquely Incident Electromagnetic Waves Propagating in One Dimension Plasma Photonic Crystals

    Institute of Scientific and Technical Information of China (English)

    GUO Bin

    2009-01-01

    Based on the electromagnetic theory and by using an analytical technique-the transfer matrix method,the obliquely incident electromagnetic waves propagating in one-dimension plasma photonic crystals is studied.The dispersion relations for both the P-polarization waves and S-polarization waves,depending on the plasma density,plasma thickness and period,are discussed.

  11. Effect of Cr underlayer on obliquely sputtered Co on PET substrate

    NARCIS (Netherlands)

    Nguyen, L.T.; Lisfi, A.; Phan le kim, P.L.K.; Lodder, J.C.; Keim, Enrico G.

    2002-01-01

    Oblique deposition of magnetic films is often used for magnetic recording tape. The well known materials are Co and CoNi deposited by reactive evaporation with O/sub 2/ directly on a polymer substrate. However, for the next generation of high density media the desirable magnetic properties have not

  12. On Children's Uses of "from,""by" and "with" in Oblique Noun Phrases.

    Science.gov (United States)

    Clark, Eve V.; Carpenter, Kathie L.

    1989-01-01

    A study of two- to six-year-olds' spontaneous uses of "from" to mark oblique agents showed that, while the two-year-olds produced "from" for agents and "with" for instruments in imitation, older subjects shifted to "by" for agents and kept "from" to mark locative sources. (Author/CB)

  13. Implementation of the critical points model in a SFM-FDTD code working in oblique incidence

    Energy Technology Data Exchange (ETDEWEB)

    Hamidi, M; Belkhir, A; Lamrous, O [Laboratoire de Physique et Chimie Quantique, Universite Mouloud Mammeri, Tizi-Ouzou (Algeria); Baida, F I, E-mail: omarlamrous@mail.ummto.dz [Departement d' Optique P.M. Duffieux, Institut FEMTO-ST UMR 6174 CNRS Universite de Franche-Comte, 25030 Besancon Cedex (France)

    2011-06-22

    We describe the implementation of the critical points model in a finite-difference-time-domain code working in oblique incidence and dealing with dispersive media through the split field method. Some tests are presented to validate our code in addition to an application devoted to plasmon resonance of a gold nanoparticles grating.

  14. Applications of Oblique-Incidence Reflectivity Difference Method in Primary Study of Protein Biomolecules

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-Yan; LIANG Ru-Qiang; JIN Kui-Juan; L(U) Hui-Bin; ZHU Xiang-Dong; ZHOU Yue-Liang; RUAN Kang-Cheng; YANG Guo-Zhen

    2006-01-01

    @@ Oblique-incidence reftectivity difference (OI-RD) analysis is applied to detect the immunoglobulin-G and cytochrome biomolecules on standard glass substrates without fluorescence labelling. The OI-RD intensities not only depend on the protein structure, but also vary with the protein concentration. The results indicate that this method should have potential applications in detection of biochemical processes.

  15. Influence of carrying a backpack on pelvic tilt, rotation, and obliquity in female college students.

    Science.gov (United States)

    Smith, Barbara; Ashton, Kelly M; Bohl, Danielle; Clark, Richard C; Metheny, J Brooke; Klassen, Stephanie

    2006-04-01

    The purpose of this investigation was to examine the influence of different methods of backpack carriage on pelvic tilt, obliquity and rotation of college-age females. Thirty subjects (mean age 22.4 years) participated in three conditions: walking without a backpack, carrying a backpack unilaterally, and carrying a backpack over both shoulders. The backpack was loaded with material that comprised 15% of the subject's body weight. Gait was analyzed using the Oxford Metrics VICON Clinical Manager system while the subject walked with no backpack, with a backpack unilaterally and bilaterally. Repeated measures analysis of variance was used to determine differences in angular motion and range of motion in pelvic tilt, rotation, and obliquity in three complete trials during the three walking conditions. Angular pelvic tilt was greatest with bilateral backpack carriage compared to unilateral carriage or walking without a backpack. Angles of pelvic obliquity and rotation were not changed across the three walking conditions. Range of motion for pelvic obliquity and rotation was significantly decreased when walking with a backpack. These results suggest that backpack carriage could cause permanent posture deviations in young female college students. More study is required to evaluate compressive forces during various walking conditions.

  16. Errors in oblique cephalometric radiographic projections of the edentulous mandible. Part I: Geometric errors

    NARCIS (Netherlands)

    Steen, W.H.A.

    1984-01-01

    Geometric errors that occur in oblique cephalometric radiographic projections of the edentulous mandible were calculated for different focal-spot-to-object distances (1500, 3000, and 6000 mm). The horizontal errors from tolerance of the porion and nasion fixation in the cephalostat were calculated.

  17. Quantum treatment of Hénon-Heiles systems using oblique coordinates

    Science.gov (United States)

    Zúñiga, José; Bastida, Adolfo; Requena, Alberto

    2017-01-01

    In this work we investigate the possibility of using oblique coordinates to determine the energy levels and wave functions of Hénon-Heiles coupled oscillator systems. Oblique coordinates are constructed by making a non-orthogonal linear transformation which permits the expression of the matrix representation of the second-order Hamiltonian operator of the system in a block-diagonal form. They are especially indicated for the treatment of Hénon-Heiles systems with two dissociative channels, which are representative of the stretching vibrational motions of symmetrical triatomic molecules. The ability of oblique coordinates to facilitate the solution of the vibrational Schrödinger equation versus normal coordinates and orthogonal rotated coordinates is analyzed by carrying out linear variational calculations with anharmonic basis function sets. It is shown that oblique coordinates require a considerably smaller number of basis functions than normal and rotated coordinates to variationally converge all the bound energy levels of the Hénon-Heiles potential with two dissociative channels to a given accuracy.

  18. Flow resistance of vegetated oblique weir-like obstacles during high water stages

    NARCIS (Netherlands)

    Ali, S.; Uijttewaal, W.S.J.

    2011-01-01

    At high water stages obstacles in the floodplains of a river contribute to the flow resistance. In particular the elevated vegetated parts are expected to play an important role. The objective of this study is to estimate and parameterize the form drag due to vegetated oblique weir-like obstacles. A

  19. Oblique Surface Waves on a Pair of Planar Periodic Slotted Waveguides

    CERN Document Server

    Tannous, C; Amram, M

    1995-01-01

    The dispersion relation and mode amplitudes of oblique surface waves propagating on an acoustic double comb filter are obtained with a method based on the calculus of residues. We obtain a better agreement (below 480 Hz) between theoretical predictions and measurements reported previously when the filter was being supposed to be made of a single comb structure.

  20. NiAl seed layer for obliquely sputtered thin film tape

    NARCIS (Netherlands)

    Nguyen, L.T.; Hozoi, A.; Lodder, J.C.

    2004-01-01

    Two types of magnetic tape were produced by oblique sputtering with the incident angle of 65/spl plusmn/5/spl deg/. One consists of a 180-nm Cr underlayer layer and 20-nm Co layer. The other consists of a 90-nm NiAl seed layer, 90-nm Cr intermediate layer, and 20-nm Co layer. It is shown that the us

  1. Oblique-Length Contraction Factor in the Special Theory of Relativity

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2013-01-01

    Full Text Available In this paper one generalizes the Lorentz Contraction Factor for the case when the lengths are moving at an oblique angle with respect to the motion direction. One shows that the angles of the moving relativistic objects are distorted.

  2. Atherosclerotic plaque fibrous cap assessment under an oblique scan plane orientation in carotid MRI

    NARCIS (Netherlands)

    Nieuwstadt, H.A.; Van der Lugt, A.; Kassar, Z.A.M.; Breeuwer, M.; Van der Steen, A.F.W.; Gijsen, F.J.H.

    2014-01-01

    Carotid magnetic resonance imaging (MRI) is used to noninvasively assess atherosclerotic plaque fibrous cap (FC) status, which is closely related to ischemic stroke. Acquiring anisotropic voxels improves in-plane visualization, however, an oblique scan plane orientation could then obscure a FC (i.e.

  3. Difference between supine and upright blood pressure associates to the efficacy of midodrine on postural orthostatic tachycardia syndrome (POTS) in children.

    Science.gov (United States)

    Deng, Wenjun; Liu, Yanling; Liu, Angie Dong; Holmberg, Lukas; Ochs, Todd; Li, Xueying; Yang, Jinyan; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2014-04-01

    Postural orthostatic tachycardia syndrome (POTS) is common, and has a serious impact on children's quality of life. Midodrine hydrochloride, an α1-adrenoreceptor agonist, is an effective treatment. The study was designed to examine the therapeutic efficacy of midodrine hydrochloride by quantifying changes in blood pressure during the head-up test (HUT), in children with POTS. Overall, 104 out of 110 children with POTS were treated with midodrine hydrochloride and successfully followed-up. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) changes were analyzed during the HUT. In a retrospective analysis, a receiver operating characteristic (ROC) curve was used to analyze the therapeutic predictive value of pre-treatment changes in SBP, DBP, and a combination of both, from the supine position to standing, in the subjects. The increase of SBP and DBP from the supine position to standing in responders were significantly lower than that of the non-responders. The ROC curve showed that midodrine hydrochloride for children with POTS would be predicted to be effective when the pre-treatment increase of SBP was ≤ 0 mmHg, or when the pre-treatment increase of DBP was ≤ 6.5 mmHg (from the supine position to standing), yielding a sensitivity of 72% and specificity of 88%. The area under the curve was 0.744 and 0.809, respectively. Hence, the results suggested that looking at the changes in blood pressure during the HUT was useful in predicting the response to midodrine hydrochloride in children with POTS.

  4. Relationship Between Respiratory Dynamics and Body Mass Index in Patients Undergoing General Anesthesia with Laryngeal Mask Airway (LMA) and Comparison Between Lithotomy and Supine Positions.

    Science.gov (United States)

    Zhao, Xiao; Huang, Shiwei; Wang, Zhaomin; Chen, Lianhua; Li, Shitong

    2016-08-01

    BACKGROUND This study aimed to compare respiratory dynamics in patients undergoing general anesthesia with a laryngeal mask airway (LMA) in lithotomy and supine positions and to validate the impact of operational position on effectiveness of LMA ventilation. MATERIAL AND METHODS A total of 90 patients (age range, 18-65 years) who underwent general anesthesia were selected and divided into supine position (SP group) and lithotomy position groups (LP group). Vital signs and respiratory dynamic parameters of the 2 groups were measured at different time points and after implantation of an LMA. The arterial blood gas was monitored at 15 min after induction. The intraoperative changes of hemodynamic indexes and postoperative adverse reactions of LMA were recorded. The possible correlation between body mass index (BMI) and respiratory dynamic indexes was analyzed. RESULTS With prolonged duration of the operation, the inspiratory plateau pressure (Pplat), inspiratory resistance (RI), and work of breathing (WOB) gradually increased, while chest-lung compliance (Compl) and partial pressure of carbon dioxide in end-expiratory gas (PetCO2) gradually decreased (all P value <0.05). The mean airway pressure (Pmean), Pplat, and expiratory resistance (Re) in the LP group were significantly higher than in the SP group (P<0.05), while the peak inspiratory flow (FImax), peak expiratory flow (FEmax), WOB, and Compl in the LP group were significantly lower than in the SP group (P<0.05). BMI was positively correlated with peak airway pressure (PIP/Ppeak), Pplat, and airway resistance (Raw) and was negatively correlated with Compl; the differences among patients in lithotomy position were more remarkable (P<0.05). CONCLUSIONS The inspiratory plateau pressure and airway resistance increased with prolonged duration of the operation, accompanied by decreased chest-lung compliance. Peak airway pressure and airway resistance were positively correlated with BMI, and chest-lung compliance was

  5. [Case-control study on the occurrence of cubitus varus deformity after humeral supracondylar fractures treated with plaster fixation in pronated or supinated position in children].

    Science.gov (United States)

    Lu, Min; Chen, Yi; Chen, Wei

    2014-11-01

    To retrospectively compare the occurrence of cubitus varus deformity after humeral supracondylar fractures treated with manipulative reduction and plaster fixation in pronated or supinated position in children, and to guide clinical treatment. From June 2009 to December 2011, the medical data of 64 children with humeral supracondylar fractures treated by manipulative reduction and plaster fixation were reviewed. All the patients were divided into two groups: group A and group B. The 30 patients in group A were treated with manipulative reduction and plaster fixation in pronation, including 18 males and 12 females, with a mean age of (7.5 ± 3.5) years old. The 34 patients in group B were treated with manipulative reduction and plaster fixation in supination, including 23 males and 11 females, with a mean age of (7.0 ± 2.6) years old. The occurrence rates of cubitus varus and decreases of carrying angle were compared between two groups before and after treatment. There were 13 patients in group A and 16 patients in group B having cubitus varus,which had no statistical difference (χ2 = 0.089, P = 0.765). The decrease of carrying angle were (8 ± 4) degrees in group A and (9 ± 5) degrees in group B, which had no statistical difference (t = 0.584, P = 0.564). Within group A, the occurrence rate of cubitus varus and the decrease of carrying angle between the radial deviation and the ulnar deviation had statistically significant difference (χ2 = 6.160, P = 0.013; t = - 2.409, P = 0.035). Within group B, the occurrence rate of cubitus varus and the decrease of carrying angle between the radial deviation and the ulnar deviation had statistically significant difference (χ2 = 5.120, P = 0.024; t = -2.250, P = 0.041). The elbow function Flynn evaluation score had no significant difference between two groups (P = -0.822). The occurrence rate of cybutys varys and the decrease of carrying angle have no obvious difference in children with humeral supracondylar fractures

  6. Vestibular Aqueduct Measurements in the 45° Oblique (Pöschl) Plane.

    Science.gov (United States)

    Juliano, A F; Ting, E Y; Mingkwansook, V; Hamberg, L M; Curtin, H D

    2016-07-01

    The 45° oblique (Pöschl) plane allows reliable depiction of the vestibular aqueduct, with virtually its entire length often visible on 1 CT image. We measured its midpoint width in this plane, aiming to determine normal measurement values based on this plane. We retrospectively evaluated temporal bone CT studies of 96 pediatric patients without sensorineural hearing loss. Midvestibular aqueduct widths were measured in the 45° oblique plane by 2 independent readers by visual assessment (subjective technique). The vestibular aqueducts in 4 human cadaver specimens were also measured in this plane. In addition, there was a specimen that had undergone CT scanning before sectioning, and measurements made on that CT scan and on the histologic section were compared. Measurements from the 96 patients' CT images were then repeated by using findings derived from the radiologic-histologic comparison (objective technique). All vestibular aqueducts were clearly identifiable on 45° oblique-plane CT images. The mean for subjective measurement was 0.526 ± 0.08 mm (range, 0.337-0.947 mm). The 97.5th percentile value was 0.702 mm. The mean for objective measurement was 0.537 ± 0.077 mm (range, 0.331-0.922 mm). The 97.5th percentile value was 0.717 mm. Measurements of the vestibular aqueduct can be performed reliably and accurately in the 45° oblique plane. The mean midpoint width was 0.5 mm, with a range of 0.3-0.9 mm. These may be considered normal measurement values for the vestibular aqueduct midpoint width when measured in the 45° oblique plane. © 2016 by American Journal of Neuroradiology.

  7. Three-dimensional analytical description of magnetized winds from oblique pulsars

    Science.gov (United States)

    Tchekhovskoy, Alexander; Philippov, Alexander; Spitkovsky, Anatoly

    2016-04-01

    Rotating neutron stars, or pulsars and magnetars, are plausibly the source of power behind many astrophysical systems, such as gamma-ray bursts, supernovae, pulsar wind nebulae, and supernova remnants. In the past several years, three-dimensional (3D) numerical simulations made it possible to compute pulsar spin-down luminosity from first principles and revealed that oblique pulsar winds are more powerful than aligned ones. However, what causes this enhanced power output of oblique pulsars is not understood. In this work, using time-dependent 3D magnetohydrodynamic and force-free simulations, we show that, contrary to the standard paradigm, the open magnetic flux, which carries the energy away from the pulsar, is laterally non-uniform. We argue that this non-uniformity is the primary reason for the increased luminosity of oblique pulsars. To demonstrate this, we construct simple analytic descriptions of aligned and orthogonal pulsar winds and combine them to obtain an accurate 3D description of the pulsar wind for any obliquity. Our approach describes both the warped magnetospheric current sheet and the smooth variation of pulsar wind properties outside of it. We find that the jump in magnetic field components across the current sheet decreases with increasing obliquity, which could be a mechanism that reduces dissipation in near-orthogonal pulsars. Our analytical description of the pulsar wind can be used for constructing models of pulsar gamma-ray emission, pulsar wind nebulae, neutron star powered ultra-luminous X-ray sources, and magnetar-powered core-collapse gamma-ray bursts and supernovae.

  8. Subduction obliquity as a prime indicator for geotherm in subduction zone

    Science.gov (United States)

    Plunder, Alexis; Thieulot, Cédric; van Hinsbergen, Douwe

    2016-04-01

    The geotherm of a subduction zone is thought to vary as a function of subduction rate and the age of the subducting lithosphere. Along a single subduction zone the rate of subduction can strongly vary due to changes in the angle between the trench and the plate convergence vector, namely the subduction obliquity. This phenomenon is observed all around the Pacific (i.e., Marianna, South America, Aleutian…). However due to observed differences in subducting lithosphere age or lateral convergence rate in nature, the quantification of temperature variation due to obliquity is not obvious. In order to investigate this effect, 3D generic numerical models were carried out using the finite element code ELEFANT. We designed a simplified setup to avoid interaction with other parameters. An ocean/ocean subduction setting was chosen and the domain is represented by a 800 × 300 × 200 km Cartesian box. The trench geometry is prescribed by means of a simple arc-tangent function. Velocity of the subducting lithosphere is prescribed using the analytical solution for corner flow and only the energy conservation equation is solved in the domain. Results are analysed after steady state is reached. First results show that the effect of the trench curvature on the geotherm with respect to the convergence direction is not negligible. A small obliquity yields isotherms which are very slightly deflected upwards where the obliquity is maximum. With an angle of ˜30°, the isotherms are deflected upwards of about 10 kilometres. Strong obliquity (i.e., angles from 60° to almost 90°) reveal extreme effects of the position of the isotherms. Further model will include other parameter as the dip of the slab and convergence rate to highlight their relative influence on the geotherm of subduction zone.

  9. ELASTIC-PLASTIC DYNAMIC RESPONSE OF A CANTILEVER BEAM SUBJECTED TO OBLIQUE IMPACT AT ITS TIP

    Institute of Scientific and Technical Information of China (English)

    Xi Feng; Liu Feng

    2005-01-01

    By employing large deformation governing equations expressed in the form of finite difference, the dynamic responses of an elastic, perfectly plastic cantilever subjected to an oblique impact at its tip was numerically studied. Through analyzing the instantaneous distribution of the yield function (ψ= |M/Mo|+ (N/No)2), bending moment and axial force during the early stage of the response, the elastic-plastic deformation mechanism and the influence of axial component of an oblique impact on the dynamic response of a cantilever beam were discussed. The present analysis shows that the deformation mechanism of an elastic-plastic cantilever subjected to an obtained by using the rigid, perfectly plastic approach, the mode of shrinking plastic region that occurred instantly after the oblique impact and the mode of stationary hinge were both confirmed.The primary features of the deformation mechanism are captured by both analysis methods. It has also been found that the beam's deformation is mainly controlled by the axial component of the oblique impact in the early phase of the dynamic response, the deformation mechanism is obviously different from the case of a transverse impact. With further development of the response,the axial component attenuates rapidly and gives negligible contribution to the yielding of the beam cross-section. At the same time, the bending moments along the cantilever develop gradually and dominate the beam's deformation. The numerical results indicate that the mass, impact speed and oblique angle are the important factors that influence the elastic-plastic dynamic response of a cantilever beam.

  10. A numerical analysis of empty and foam-filled aluminium conical tubes under oblique impact loading

    Science.gov (United States)

    Mat, Fauziah; Ismail, Khairul Azwan; Yaacob, Sazali

    2015-05-01

    In real impact applications, an energy absorber rarely sustains dynamic loading either axial or oblique but a combination of both. Established studies have proved that thin-walled tube is an excellent energy absorber under dynamic loading. Furthermore, the introduction of foam filling successfully enhanced the energy absorption capacity of thin-walled tube. However, the understanding of its response under oblique loading has yet been fully explored. Moreover, emerging in automotive industry has lead to increase interests on lightweight materials such as aluminium alloy. As such, this paper presents the crushing behaviour of empty and foam-filled aluminium alloy (AA6061-T6) conical tubes under oblique impact loading using a validated nonlinear finite element (FE) code, LS-DYNA. The study aims to assess the effect of foam filling on the energy absorption of AA6061-T6 tubes for variations in filler density. In fact, to the best of our knowledge, this study is the first attempt to evaluate a response of empty and foam-filled aluminum conical tube by using an experimentally validated model under oblique dynamic loading conditions. Good correlations between the numerical and experimental results were observed. The study show that initial peak force and the energy absorption increase with increasing filler density under axial and oblique loading. On the other hand, the effect of foam filling (0.534 g/cm3 aluminium foam filler) is less pronounced for the initial peak force under axial impact loading. Furthermore, the initial peak force and dynamic force of empty and foam-filled AA6061-T6 conical tubes decrease as the load angle increases from 0 deg to 20 deg hence reduces the energy absorption capacity.

  11. Outcomes of pediatric inguinal hernia repair with or without opening the external oblique muscle fascia

    Directory of Open Access Journals (Sweden)

    Masoud Nazem

    2015-01-01

    Full Text Available Background: Considering that complications and outcome of each method of pediatric inguinal hernia repair are one of the determinants for pediatric surgeons for selection of the appropriate surgical technique, we compared the early and late complications of two inguinal repair techniques, with and without opening the external oblique muscle fascia. Materials and Methods: In this double-blind clinical trial study, boy children aged 1-month to 6 years with diagnosed inguinal hernia were included and randomly allocated into two groups for undergoing two types of hernia repair techniques, with and without opening the external oblique muscle fascia. Surgical complications such as fever, scrotal edema and hematoma, and wound infections classified as early complication and recurrence, testis atrophy and sensory impairment of inguinal area classified as late complications. The rates of mentioned early and late complications were compared in the two interventional groups. Results: In this study, 66 patients were selected and allocated to the two interventional groups. The prevalence of early and late complications in two studied groups were not different significantly in two interventional groups (P > 0.05. Operation time was significantly shorter in inguinal repair techniques without opening the external oblique muscle fascia than the other studied technique (P = 0.001. Conclusion: The findings of our study indicated that though early and late complications of the two repair methods were similar, but the time of procedure was shorter in herniotomy without opening the external oblique muscle, which considered the superiority of this method than inguinal hernia repair with opening the external oblique muscle.

  12. Outcomes of pediatric inguinal hernia repair with or without opening the external oblique muscle fascia

    Science.gov (United States)

    Nazem, Masoud; Dastgerdi, Mohamad Masoud Heydari; Sirousfard, Motaherh

    2015-01-01

    Background: Considering that complications and outcome of each method of pediatric inguinal hernia repair are one of the determinants for pediatric surgeons for selection of the appropriate surgical technique, we compared the early and late complications of two inguinal repair techniques, with and without opening the external oblique muscle fascia. Materials and Methods: In this double-blind clinical trial study, boy children aged 1-month to 6 years with diagnosed inguinal hernia were included and randomly allocated into two groups for undergoing two types of hernia repair techniques, with and without opening the external oblique muscle fascia. Surgical complications such as fever, scrotal edema and hematoma, and wound infections classified as early complication and recurrence, testis atrophy and sensory impairment of inguinal area classified as late complications. The rates of mentioned early and late complications were compared in the two interventional groups. Results: In this study, 66 patients were selected and allocated to the two interventional groups. The prevalence of early and late complications in two studied groups were not different significantly in two interventional groups (P > 0.05). Operation time was significantly shorter in inguinal repair techniques without opening the external oblique muscle fascia than the other studied technique (P = 0.001). Conclusion: The findings of our study indicated that though early and late complications of the two repair methods were similar, but the time of procedure was shorter in herniotomy without opening the external oblique muscle, which considered the superiority of this method than inguinal hernia repair with opening the external oblique muscle. PMID:26958052

  13. Flexibility and fatigue evaluation of oblique as compared with anterior lumbar interbody cages with integrated endplate fixation.

    Science.gov (United States)

    Freeman, Andrew L; Camisa, William J; Buttermann, Glenn R; Malcolm, James R

    2016-01-01

    This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue. Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IPF + pedicle screws (6 anterior, 7 oblique). Pullout tests were then performed on the cage + IPF. Fatigue testing was conducted on the cage + IPF specimens for 30,000 cycles. No ROM differences were observed in any test group between anterior and oblique cage constructs. The greatest reduction in ROM was with supplemental pedicle screw fixation. Peak pullout forces were 637 ± 192 N and 651 ± 127 N for the anterior and oblique implants, respectively. The median cage subsidence was 0.8 mm and 1.4 mm for the anterior and oblique cages, respectively. Anterior and oblique cages similarly reduced ROM in flexibility testing, and the integrated fixation prevented device displacement. Subsidence was minimal during fatigue testing, most of which occurred in the first 2500 cycles.

  14. Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis.

    Science.gov (United States)

    Neary, Kaitlin C; Mormino, Matthew A; Wang, Hongmei

    2017-01-01

    In stress-positive, unstable supination-external rotation type 4 (SER IV) ankle fractures, implant selection for syndesmotic fixation is a debated topic. Among the available syndesmotic fixation methods, the metallic screw and the suture button have been routinely compared in the literature. In addition to strength of fixation and ability to anatomically restore the syndesmosis, costs associated with implant use have recently been called into question. This study aimed to examine the cost-effectiveness of the suture button and determine whether suture button fixation is more cost-effective than two 3.5-mm syndesmotic screws not removed on a routine postoperative basis. Economic and decision analysis; Level of evidence, 2. Studies with the highest evidence levels in the available literature were used to estimate the hardware removal and failure rates for syndesmotic screws and suture button fixation. Costs were determined by examining the average costs for patients who underwent surgery for unstable SER IV ankle fractures at a single level-1 trauma institution. A decision analysis model that allowed comparison of the 2 fixation methods was developed. Using a 20% screw hardware removal rate and a 4% suture button hardware removal rate, the total cost for 2 syndesmotic screws was US$20,836 and the total effectiveness was 5.846. This yielded a total cost of $3564 per quality-adjusted life-year (QALY) over an 8-year time period. The total cost for suture button fixation was $19,354 and the total effectiveness was 5.904, resulting in a total cost of $3294 per QALY over the same time period. A sensitivity analysis was then conducted to assess suture button fixation costs as well as screw and suture button hardware removal rates. Other possible treatment scenarios were also examined, including 1 screw and 2 suture buttons for operative fixation of the syndesmosis. To become more cost-effective, the screw hardware removal rate would have to be reduced to less than 10

  15. Spatial evolution of Zagros collision zone in Kurdistan, NW Iran: constraints on Arabia-Eurasia oblique convergence

    Science.gov (United States)

    Sadeghi, Shahriar; Yassaghi, Ali

    2016-04-01

    Stratigraphy, detailed structural mapping and a crustal-scale cross section across the NW Zagros collision zone provide constraints on the spatial evolution of oblique convergence of the Arabian and Eurasian plates since the Late Cretaceous. The Zagros collision zone in NW Iran consists of the internal Sanandaj-Sirjan, Gaveh Rud and Ophiolite zones and the external Bisotoun, Radiolarite and High Zagros zones. The Main Zagros Thrust is the major structure of the Zagros suture zone. Two stages of oblique deformation are recognized in the external part of the NW Zagros in Iran. In the early stage, coexisting dextral strike-slip and reverse dominated domains in the Radiolarite zone developed in response to deformation partitioning due to oblique convergence. Dextral-reverse faults in the Bisotoun zone are also compatible with oblique convergence. In the late stage, deformation partitioning occurred during southeastward propagation of the Zagros orogeny towards its foreland resulting in synchronous development of orogen-parallel strike-slip and thrust faults. It is proposed that the first stage was related to Late Cretaceous oblique obduction, while the second stage resulted from Cenozoic collision. The Cenozoic orogen-parallel strike-slip component of Zagros oblique convergence is not confined to the Zagros suture zone (Main Recent Fault) but also occurred in the external part (Marekhil-Ravansar fault system). Thus, it is proposed that oblique convergence of Arabian and Eurasian plates in Zagros collision zone initiated with oblique obduction in the Late Cretaceous followed by oblique collision in the late Tertiary, consistent with global plate reconstructions.

  16. Effect of Lumbar Disc Degeneration and Low-Back Pain on the Lumbar Lordosis in Supine and Standing: A Cross-Sectional MRI Study.

    Science.gov (United States)

    Hansen, Bjarke B; Bendix, Tom; Grindsted, Jacob; Bliddal, Henning; Christensen, Robin; Hansen, Philip; Riis, Robert G C; Boesen, Mikael

    2015-11-01

    Cross-sectional study. To examine the influence of low-back pain (LBP) and lumbar disc degeneration (LDD) on the lumbar lordosis in weight-bearing positional magnetic resonance imaging (pMRI). The lumbar lordosis increases with a change of position from supine to standing and is known as an essential contributor to dynamic changes. However, the lordosis may be affected by disc degeneration and pain. Patients with LBP >40 on a 0 to 100 mm Visual Analog Scale (VAS) both during activity and rest and a sex and age-decade matching control group without LBP were scanned in the supine and standing position in a 0.25-T open MRI unit. LDD was graded using Pfirrmann's grading-scale. Subsequently, the L2-to-S1 lumbar lordosis angle (LA) was measured. Thirty-eight patients with an average VAS of 58 (±13.8) mm during rest and 75 (±5.0) mm during activities, and 38 healthy controls were included. MRI findings were common in both groups, whereas, the summation of the Pfirrmann's grades (LDD-score) was significantly higher in the patients [(MD 1.44; 95% confidence intervals (CI) 0.80 to 2.10; P lordosis between the positions may be independent of pain. Decreasing lordosis change seems to be associated with age-related increasing disc degeneration in healthy individuals. 2.

  17. Venous velocity of the right femoral vein decreases in the right lateral decubitus position compared to the supine position: a cause of postoperative pulmonary embolism?

    Directory of Open Access Journals (Sweden)

    Sato,Shizou

    2007-04-01

    Full Text Available The right lateral decubitus position is a risk factor for postoperative pulmonary embolism. We examined postural changes of femoral vein velocity in order to elucidate the mechanism. Thirty patients scheduled for general thoracic surgery were enrolled in this study. The common femoral veins on both sides were examined by color-duplex ultrasound for venous caliber and velocity when the patients were in the right lateral, left lateral, and supine positions. The maximum diameters of the right femoral vein in the right lateral decubitus position and the left femoral vein in the left decubitus position were significantly larger than those in the other positions. The venous velocity of the right femoral vein in the right lateral decubitus position was significantly smaller than that in the supine position, while the velocity of the left femoral vein in the left lateral decubitus position was not significantly decreased. We speculate that the decreased venous velocity of the right femoral vein in the right lateral decubitus position could result in a deep venous thromboembolism in the right leg, making this position a possible risk factor for postoperative pulmonary embolism.

  18. Abrupt plate acceleration through oblique rifting: Geodynamic aspects of Gulf of California evolution

    Science.gov (United States)

    Brune, S.

    2016-12-01

    The Gulf of California formed by oblique divergence across the Pacific-North America plate boundary. This presentation combines numerical forward modeling and plate tectonic reconstructions in order to address 2 important aspects of rift dynamics: (1) Plate motions during continental rifting are decisively controlled by the non-linear decay of rift strength. This conclusion is based on a recent plate-kinematic analysis of post-Pangea rift systems (Central Atlantic, South Atlantic, Iberia/Newfoundland, Australia/Antarctica, North Atlantic, South China Sea). In all cases, continental rifting starts with a slow phase followed by an abrupt acceleration within a few My introducing a fast rift phase. Numerical forward modeling with force boundary conditions shows that the two-phase velocity behavior and the rapid speed-up during rifting are intrinsic features of continental rupture that can be robustly inferred for different crust and mantle rheologies. (2) Rift strength depends on the obliquity of the rift system: the force required to maintain a given rift velocity can be computed from simple analytical and more realistic numerical models alike, and both modeling approaches demonstrate that less force is required to perpetuate oblique extension. The reason is that plastic yielding requires a smaller plate boundary force when extension is oblique to the rift trend. Comparing strike slip and pure extension end-member scenarios, it can be shown that about 50% less force is required to deform the lithosphere under strike-slip. This result implies that rift systems involving significant obliquity are mechanically preferred. These two aspects shed new light on the underlying geodynamic causes of Gulf of California rift history. Continental extension is thought to have started in Late Eocene/Oligocene times as part of the southern Basin and Range Province and evolved in a protracted history at low extension rate (≤15 mm/yr). However, with a direction change in Baja

  19. Obliquity-Controlled Water Vapor/Trace Gas Feedback in the Martian Greenhouse Cycle

    Science.gov (United States)

    Mischna, M. A.; Baker, V. R.; Milliken, R.; Richardson, M. I.; Lee, C.

    2013-12-01

    We have explored possible mechanisms for the generation of warm, wet climates on early Mars as a result of greenhouse warming by both water vapor and periodic volcanic trace gas emissions, using the Mars Weather Research and Forecasting (MarsWRF) general circulation model. The presence of both water vapor (a strong greenhouse gas) and other trace greenhouse gases (such as SO2) in a predominantly CO2 atmosphere may act, under certain conditions, to elevate surface temperatures above the freezing point of liquid water, at least episodically. The levels of warming obtained in our simulations do not reach the values seen in Johnson et al., (2008, JGR, 113, E08005), nor are they widespread for extended periods. Rather, warming above 273 K is found in more localized environments and for geologically brief periods of time. Such periodic episodes are controlled by two factors. First is the obliquity of the planet, which plays a significant role is ';activating' extant surface water ice reservoirs, allowing levels of atmospheric water vapor to rise when obliquity is high, and fall precipitously when the obliquity is low. During these low-obliquity periods, the atmosphere is all but incapable of supporting warm surface temperatures except for brief episodes localized wholly in the tropics; thus, there is a natural regulator in the obliquity cycle for maintaining periodic warming. Second is the presence of a secondary trace gas 'trigger', like volcanically released SO2, in the atmosphere. In the absence of such a trace gas, water vapor alone appears incapable of raising temperatures above the melting point; however, by temporarily raising the baseline global temperatures (in the absence of warming by water vapor) by 10-15 K, as with SO2, the trigger gas keeps atmospheric temperatures sufficiently warm, especially during nighttime, to maintain levels of water vapor in the atmosphere that provide the needed warming. Furthermore, we find that global warming can be achieved more

  20. Aerial Photography and Imagery, Oblique, Digital photos taken of PA's Lake Erie shoreline and Presque Isle at an oblique angle at about 1,500-2,000' altitude., Published in 2017, Not Applicable scale, Pennsylvania Coastal Resources Management Program.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Oblique dataset, published at Not Applicable scale, was produced all or in part from Uncorrected Imagery information as of 2017....