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Sample records for caudolateral curvilinear osteophyte

  1. ANTERIOR OSTEOPHYTE IDENTIFICATION IN CERVICAL VERTEBRAE

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    A. T. Chougale

    2011-06-01

    Full Text Available Radiologist always examines X-ray to determine abnormal changes in cervical, lumbar & thoracic vertebrae. Osteophyte (bony growth may appear at the corners of vertebrae so that vertebral shape becomes abnormal. This paper presents the idea from Image processing techniques such as customised Hough transform which will be used for segmentation which should be independent of rotation, scale, noise & shape. This segmented image will be then used for computing size invariant, convex hull based features to differentiate normal cervical vertebrae from cervical vertebrae containing anterior osteophyte. This approach effectively finds anterior osteophytes in cervical vertebrae.

  2. Evaluation of a caudolateral approach for arthrocentesis and injection of the equine elbow joint.

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    Bodaan, C J; Riley, C B; Engeli, E

    2016-08-13

    The objectives of this study were to evaluate the likelihood of successful arthrocentesis of the equine elbow joint using the caudolateral approach and to determine if the deep branch of the radial nerve (DBRN) varies in its proximity to the site of centesis. Methylene blue (MB) was injected into 71 elbow joint specimens immediately caudal to the lateral collateral ligament using a 3.8-cm needle advanced to its hub. The elbow joints were dissected, staining of the synovial structures assessed and the proximity of DBRN to the site of centesis evaluated. The articular cartilage of all 71 joints was stained with MB. The location of DBRN did not vary substantially among the specimens and did not course close to the site of centesis. Direct communication was found between the bursa of the tendon of the ulnaris lateralis muscle and the elbow joint in 41 of 71 specimens (57.8 per cent). The caudolateral approach for centesis of the equine elbow joint, performed by inserting a needle 3.8-cm, was found to be reliable. Radial nerve paralysis reported to be caused by injection of local anaesthetic solution using the caudolateral approach may be due to diffusion of the solution from the dorsal pouch rather than from leakage at the site of centesis.

  3. Direction of the formation of anterior lumbar vertebral osteophytes

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    Akeda Koji

    2009-01-01

    Full Text Available Abstract Background X-ray images of lumbar degenerative diseases often show not only claw osteophytes, but also pairs of osteophytes that form in a direction away from the adjacent disc. We have investigated the direction of the formation of anterior lumbar vertebral osteophytes across the lumbar vertebrae using a sufficient number of lumbar radiographs, because osteophytes images can provide essential information that will contribute to the understanding of the pathology and progress of lumbar spine degeneration. Methods The direction of the formation of 14,250 pairs of anterior lumbar vertebral osteophytes across the adjacent intervertebral discs in 2,850 patients who were all over 60 years old was investigated. Anterior lumbar vertebral osteophytes were distributed into six groups based on the direction of extension of each pair of osteophytes across the intervertebral disc space. Results In L1–L2 and L2–L3, the number of patients classified into groups B (the pair of osteophytes extended in the direction of the adjacent disc and C (almost complete bone bridge formation by a pair of osteophytes across the intervertebral disc space was larger than that classified into group D (the pair of osteophytes extended in a direction away from the adjacent disc. In L3–L4, L4–L5 and L5-S1, the number of patients in group D was greater than that of patients belonging to groups B and C. Conclusion Our study showed that pairs of osteophytes frequently formed in the direction of the adjacent disc in the upper lumbar vertebrae (L1–L2 and L2–L3 and in the direction away from the adjacent disc in middle or lower lumbar vertebrae (L3–L4, L4–L5, and L5-S1.

  4. The role of phonophoresis in dyshpagia due to cervical osteophytes

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    Zeliha Unlu

    2008-08-01

    Full Text Available Zeliha Unlu1, Sebnem Orguc2, Gorkem Eskiizmir3, Asim Aslan3, Saliha Tasci11Department of Physical Medicine and Rehabilitation; 2Department of Radiology; 3Department of Otorhinolaryngology, Celal Bayar University School of Medicine, Manisa, TurkeyObjective: Treatment of patients with anterior cervical osteophytes causing dysphagia includes conservative treatment with anti-inflammatory drugs, muscle relaxants, antibiotics, and an appropriate soft diet. Physical therapy with its advantages may be an alternative method in the treatment, which was not reported previously.Case description: Phonophoresis therapy is applied in nine patients with dysphagia due to cervical osteophytes.Results: The symptom of dysphagia regressed in various degrees in all patients after phonophoresis therapy.Conclusions: Phonophoresis might be an alternative method for the non-steroidal anti-inflammatory drug (NSAID treatment in patients with dysphagia due to cervical osteophytes.Keywords: cervical, osteophyte, dysphagia, physical therapy

  5. Dysphagia Due to Anterior Cervical Spine Osteophyte: A Case Report

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    Hossein Mashhadinezhad

    2010-07-01

    Full Text Available Introduction: Degenerative changes of the cervical spine are more common in elderly, but anterior cervical osteophytes that cause problems in swallowing are rare. The most common cause of this problem is DISH disease (diffuse idiopathic skeletal hyperostosis. Trauma is also suggested as a potential cause in osteophyte formation. Case Report: We report a rare case of anterior cervical osteophyte with problems in swallowing that was caused by cervical spine trauma in a car accident 4 years ago, treated with a cervical collar. Dysphagia was the initial symptom of the disease. Barium swallowing showed a large cervical osteophyte at the C3-C4 level with compression effect on the esophagus. X-ray, CT scan and MRI of the cervical spine confirmed the osteophyte and its correlation with the esophagus. Endoscopic study of esophagus and stomach also ruled out other disorders. Surgical osteophytectomy was performed. Conclusion: Up to now, only two cases of post-traumatic anterior cervical osteophyte have been cited in the literature. In this report, we introduce an unusual case of dysphagia caused by cervical spine trauma.

  6. Photonic curvilinear data processing

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    Browning, Clyde; Quaglio, Thomas; Figueiro, Thiago; Pauliac, Sébastien; Belledent, Jérôme; Fay, Aurélien; Bustos, Jessy; Marusic, Jean-Christophe; Schiavone, Patrick

    2014-10-01

    With more and more photonic data presence in e-beam lithography, the need for efficient and accurate data fracturing is required to meet acceptable manufacturing cycle time. Large photonic based layouts now create high shot count patterns for VSB based tools. Multiple angles, sweeping curves, and non-orthogonal data create a challenge for today's e-beam tools that are more efficient on Manhattan style data. This paper describes techniques developed and used for creating fractured data for VSB based pattern generators. Proximity Effect Correction is also applied during the fracture process, taking into account variable shot sizes to apply for accuracy and design style. Choosing different fracture routines for pattern data on-the-fly allows for fast and efficient processing. Data interpretation is essential for processing curvilinear data as to its size, angle, and complexity. Fracturing complex angled data into "efficient" shot counts is no longer practical as shot creation now requires knowledge of the actual data content as seen in photonic based pattern data. Simulation and physical printing results prove the implementations for accuracy and write times compared to traditional VSB writing strategies on photonic data. Geometry tolerance is used as part of the fracturing algorithm for controlling edge placement accuracy and tuning to different e-beam processing parameters.

  7. Effects of caudolateral neostriatal ablations on pain-related behaviour in the chicken.

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    Gentle, M J; Hunter, L N; Corr, S A

    1997-04-01

    As a measure of pain-related behaviour, beak guarding was investigated by recording the pecking response of adult chickens to a visually attractive stimulus before and after bilateral suction ablation of the caudolateral neostriatum (CLN). Two control groups of birds were used: a sham-operated group and an ablated group, in which the ablation was confined to the rostral dorsolateral telencephalon. Comparing the birds that had undergone ablation with the sham-operated controls showed that the ablation did not affect pecking behaviour. Five days after ablation, all birds were subjected to partial amputation of one third of the beak. A significant reduction in pecking behaviour (beak-guarding) was observed in both control groups, but was not observed in those birds that had previously received CLN ablations. In a second experiment, where beak amputation preceeded CLN ablation by 6 days, ablation did not affect the reduced pecking. The absence of guarding or other pain-related behaviours would indicate that an intact CLN was necessary for these behaviours to develop but, once they had developed, ablation had no effect.

  8. Recurrent Aspiration Pneumonia due to Anterior Cervical Osteophyte

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    Jae Jun Lee

    2017-02-01

    Full Text Available A 74-year-old man presented with recurrent vomiting and aspiration pneumonia in the left lower lobe. He entered the intensive care unit to manage the pneumonia and septic shock. Although a percutaneous endoscopic gastrostomy tube was implanted for recurrent vomiting, vomiting and aspiration recurred frequently during admission. Subsequently, he complained of neck pain when in an upright position. A videofluoroscopic swallowing study showed compression of the esophagus by cervical osteophytes and tracheal aspiration caused by an abnormality at the laryngeal inlet. Cervical spine X-rays and computed tomography showed anterior cervical osteophytes at the C3-6 levels. Surgical decompression was scheduled, but was cancelled due to his frailty. Unfortunately, further recurrent vomiting and aspiration resulted in respiratory arrest leading to hypoxic brain damage and death. Physicians should consider cervical spine disease, such as diffuse skeletal hyperostosis as an uncommon cause of recurrent aspiration pneumonia.

  9. Dysphagia Secondary to Anterior Osteophytes of the Cervical Spine.

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    Egerter, Alexander C; Kim, Eric S; Lee, Darrin J; Liu, Jonathan J; Cadena, Gilbert; Panchal, Ripul R; Kim, Kee D

    2015-10-01

    Study Design Retrospective case series. Objective Diffuse idiopathic skeletal hyperostosis (DISH) or Forestier disease involves hyperostosis of the spinal column. Hyperostosis involving the anterior margin of the cervical vertebrae can cause dysphonia, dyspnea, and/or dysphagia. However, the natural history pertaining to the risk factors remain unknown. We present the surgical management of two cases of dysphagia secondary to cervical hyperostosis and discuss the etiology and management of DISH based on the literature review. Methods This is a retrospective review of two patients with DISH and anterior cervical osteophytes. We reviewed the preoperative and postoperative images and clinical history. Results Two patients underwent anterior cervical osteophytectomies due to severe dysphagia. At more than a year follow-up, both patients noted improvement in swallowing as well as their associated pain. Conclusion The surgical removal of cervical osteophytes can be highly successful in treating dysphagia if refractory to prolonged conservative therapy.

  10. Dysphagia produced by cervical spine osteophyte. A case report

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    Claudio Silveri

    2014-01-01

    Full Text Available We present a case of a 73-year-old male patient with progressive dysphagia, and hoarseness (irritability in the throat. He was studied with the appropriate imaging techniques, and esophagoscopy led to a diagnosis of extrinsic esophageal dysphagia for osteophyte obstruction of the cervical spine due to the arthrosis. A surgical resection was performed, without complications. Some considerations are given on this theme.

  11. Partial Arc Curvilinear Direct Drive Servomotor

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    Sun, Xiuhong (Inventor)

    2014-01-01

    A partial arc servomotor assembly having a curvilinear U-channel with two parallel rare earth permanent magnet plates facing each other and a pivoted ironless three phase coil armature winding moves between the plates. An encoder read head is fixed to a mounting plate above the coil armature winding and a curvilinear encoder scale is curved to be co-axis with the curvilinear U-channel permanent magnet track formed by the permanent magnet plates. Driven by a set of miniaturized power electronics devices closely looped with a positioning feedback encoder, the angular position and velocity of the pivoted payload is programmable and precisely controlled.

  12. Modeling of curvilinear suspension flows

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    Morris, Jeffrey F.; Boulay, Fabienne

    1996-11-01

    The curvilinear parallel-plate and cone-and-plate rheometric flows of monodisperse noncolloidal suspensions have been modeled. Although nonuniform in shear rate, dotγ, the parallel-plate flow has been shown experimentally(A. W. Chow, S. W. Sinton, J. H. Iwayima & T. S. Stephens 1994 Phys. Fluids) 6, 2561. not to exhibit particle migration, contrary to predictions of prior suspension-flow modeling. Predictions of nonuniform particle volume fraction, φ, by the suspension-balance model(P. R. Nott & J. F. Brady 1994 J. Fluid Mech.) 275, 157. for parallel-plate and cone-and-plate flow without normal stress differences are presented. The ``nonmigration'' in parallel-plate flow may be attributed to bulk suspension normal stress differences: assuming the bulk stress has the form Σ ~ η dotγ Q(φ) with η the fluid viscosity, nonmigration is predicted for parallel-plate flow provided that Q_33 = (1/2) Q_11 at the bulk φ of interest, with 1 the flow direction and 3 the vorticity direction. Extending the model to include normal stress differences satisfying this requirement, a range of migration behavior is predicted for the cone-and-plate flow depending upon the ratio Q_11/Q_22.

  13. Magnetic Resonance Image Evaluation of Temporomandibular Joint Osteophytes: Influence of Clinical Factors and Artrogenics Changes.

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    Grossmann, Eduardo; Remedi, Marcelo Pereira; Ferreira, Luciano Ambrosio; Carvalho, Antonio Carlos Pires

    2016-03-01

    This research aims to examine the presence of osteophyte in patients with arthrogenic temporomandibular disorders through magnetic resonance imaging (MRI); to investigate the influence of sex and clinical symptoms in its prevalence; and the position of the osteophytes in the condyle. The study was based on 100 MRI and on reports of patients, which corresponded to the evaluation of 200 joints. Patients of both sexes were aged from 18 to 82 years (average = 49.48) and were subjected to the aforementioned examination from January 2006 to March 2009. The assessment considered the type of disc displacement, the presence of effusion, bone marrow edema, condyle changes, joint noise and pain. The MRI machine used was the GE Signa HDX (General Electric, Milwaukee, WI), with T1 and T2-weighted, 1.5 T magnetic field, sagittal oblique (mouth closed, mouth open) and coronal (mouth closed) imaging, with spherical surface coil and an asymmetric matrix. All images were interpreted by an experienced radiologist. A total of 28% (n = 56) of the temporomandibular joints showed osteophytes on the anterior surface of the mandible. No relationship was found between sex and osteophytes. The authors found a statistically significant difference between osteophytes and disc displacement without reduction (P < 0.001). The presence of osteophytes suggested a possible cause and effect relationship between osteoarthritis and disc displacement without reduction; the osteophyte was always located in the anterior surface of condyle, regardless of the sex variable; no significant difference was found between osteophytes and the main complaints of the patient.

  14. Periarticular osteophytes as an appendicular joint stress marker (JSM: analysis in a contemporary Japanese skeletal collection.

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    Toshiyuki Tsurumoto

    Full Text Available OBJECTIVE: The aim of this study was to investigate the possibility that periarticular osteophytes plays a role as a appendicular joint stress marker (JSM which reflects the biomechanical stresses on individuals and populations. METHODS: A total of 366 contemporary Japanese skeletons (231 males, 135 females were examined closely to evaluate the periarticular osteophytes of six major joints, the shoulder, elbow, wrist, hip, knee, and ankle and osteophyte scores (OS were determined using an original grading system. These scores were aggregated and analyzed statistically from some viewpoints. RESULTS: All of the OS for the respective joints were correlated logarithmically with the age-at-death of the individuals. For 70 individuals, in whom both sides of all six joints were evaluated without missing values, the age-standardized OS were calculated. A right side dominancy was recognized in the joints of the upper extremities, shoulder and wrist joints, and the bilateral correlations were large in the three joints on the lower extremity. For the shoulder joint and the hip joint, it was inferred by some distinctions that systemic factors were relatively large. All of these six joints could be assorted by the extent of systemic and local factors on osteophytes formation. Moreover, when the age-standardized OS of all the joints was summed up, some individuals had significantly high total scores, and others had significantly low total scores; namely, all of the individuals varied greatly in their systemic predisposition for osteophytes formation. CONCLUSIONS: This study demonstrated the significance of periarticular osteophytes; the evaluating system for OS could be used to detect differences among joints and individuals. Periarticular osteophytes could be applied as an appendicular joint stress marker (JSM; by applying OS evaluating system for skeletal populations, intra-skeletal and inter-skeletal variations in biomechanical stresses throughout the

  15. Quantum mechanics as electrodynamics of curvilinear waves

    OpenAIRE

    2002-01-01

    The suggested theory is the new quantum mechanics (QM) interpretation.The research proves that QM represents the electrodynamics of the curvilinear closed (non-linear) waves. It is entirely according to the modern interpretation and explains the particularities and the results of the quantum field theory.

  16. Expression of strain tensor in orthogonal curvilinear coordinates

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    Xuyan Liu

    2010-01-01

    Full Text Available Based on an analysis of connotation and extension of the concept of the orthogonal curvilinear coordinates, we have deduced a platform of strain tensor expression of Cartesian coordinates, which turns out to be a function of Lame coefficient and unit vector. By using transform matrix between Cartesian coordinates and orthogonal curvilinear coordinates, we have deduced a mathematical expression for correcting displacement vector differential in orthogonal curvilinear coordinates, and given a general expression of strain tensor in orthogonal curvilinear coordinates.

  17. Dune-CurvilinearGrid: Parallel Dune Grid Manager for Unstructured Tetrahedral Curvilinear Meshes

    OpenAIRE

    Fomins, Aleksejs; Oswald, Benedikt

    2016-01-01

    We introduce the dune-curvilineargrid module. The module provides the self-contained, parallel grid manager, as well as the underlying elementary curvilinear geometry module dune-curvilineargeometry. This work is motivated by the need for reliable and scalable electromagnetic design of nanooptical devices. Curvilinear geometries improve both the accuracy of modeling smooth material boundaries, and the h/p-convergence rate of PDE solutions, reducing the necessary computational effort. dune-cur...

  18. Lack of association between lumbar disc degeneration and osteophyte formation in elderly japanese women with back pain.

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    Oishi, Y; Shimizu, K; Katoh, T; Nakao, H; Yamaura, M; Furuko, T; Narusawa, K; Nakamura, T

    2003-04-01

    Our study was designed to assess the contributions of the physical and constitutional factors to osteophyte formation, disc degeneration, and bone mineral density (BMD) in lumbar vertebrae of elderly postmenopausal women. A total of 126 Japanese women with back pain, aged over 60 years, were invited to participate in the study. Then 80 subjects with a full set of data for physical examinations, radiographs, MRI, and DXA were examined. TaqI polymorphism of vitamin D receptor (VDR) gene was examined in 60 subjects. Prevalence rates of osteophytes (on radiographs) and disc degeneration (on MRI) were 61 and 68%, respectively. Body weight and BMI correlated significantly with anteroposterior (AP) and lateral (LAT) BMD (r = 0.354 for weight, r = 0.347 for BMI) and mean osteophyte area (r = 0.557 for weight, r = 0.486 for BMI), and body weight also correlated with number of discs with osteophytes. However, these did not correlate with the disc area or the number of degenerated discs. Stepwise regression analysis revealed that body weight and LAT-BMD values independently related to the osteophyte area. Disc area (r = 0.386 for AP view) and osteophyte area (r = 0.384 for AP view) significantly correlated with BMD. However, disc area and osteophyte area did not correlate with each other (r = 0.056). The proportion of degenerated discs was higher in the lower lumbar discs, but not the proportion of discs with osteophytes. Frequencies of T and t alleles of VDR did not correlate with disc degeneration, osteophyte formation, or osteoporosis. Our data showed that increases in osteophyte formation and BMD in the lumbar vertebrae are influenced by body weight and BMI, but did not correlate with disc area, which correlated inversely with BMD. Disc degeneration and osteophyte formation seem to represent two different factors that affect lumbar spine in elderly women.

  19. Collar Osteophytes Mimicking Osteonecrosis in Planar Bone Scintigraphy and Usefulness of SPECT/CT Images.

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    Juang, Jr-Jian; Chen, Yi-Hsing; Tsai, Shih-Chuan; Lin, Wan-Yu

    2017-03-01

    The use of prednisolone is one major risk factor for osteonecrosis in patients with systemic lupus erythematosus. Bone scintigraphy can be a diagnostic tool for early diagnosis. We present a case who had collar osteophytes at the bilateral femoral heads, which mimicked osteonecrosis in the planar bone scintigram. An SPECT/CT scan avoided this pitfall and increased the diagnostic accuracy for osteonecrosis.

  20. Bridging osteophyte of the anterosuperior sacroiliac joint as a cause of lumbar back pain.

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    Parmar, K A; Solomon, M; Loefler, A; Dalton, S

    2004-12-01

    A case report is presented of a patient with an anterosuperior osteophytic bone bridge of the sacroiliac joint causing lumbar back pain. After prolonged physiotherapy, the bone bridge was excised, with complete resolution of the symptoms. Excision should only be considered in cases of symptomatic sacroiliac joint pain that does not respond to rehabilitation programmes and conservative treatment.

  1. Stretchable, curvilinear electronics based on inorganic materials.

    Science.gov (United States)

    Kim, Dae-Hyeong; Xiao, Jianliang; Song, Jizhou; Huang, Yonggang; Rogers, John A

    2010-05-18

    All commercial forms of electronic/optoelectronic technologies use planar, rigid substrates. Device possibilities that exploit bio-inspired designs or require intimate integration with the human body demand curvilinear shapes and/or elastic responses to large strain deformations. This article reviews progress in research designed to accomplish these outcomes with established, high-performance inorganic electronic materials and modest modifications to conventional, planar processing techniques. We outline the most well developed strategies and illustrate their use in demonstrator devices that exploit unique combinations of shape, mechanical properties and electronic performance. We conclude with an outlook on the challenges and opportunities for this emerging area of materials science and engineering.

  2. Unique relationship between osteophyte and femoral-tibia component size mismatch in determining polyethylene wear in primary total knee arthroplasty: a case report

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    Ramappa Manjunath

    2009-02-01

    Full Text Available Abstract Introduction Knee pain is a complex problem that can occur after total knee arthroplasty. One cause of knee pain may be due to a retained osteophyte, but it is not clear if the retained osteophyte is sufficient explanation of the pain, as not all patients with retained osteophytes are symptomatic. In fact, the literature shows that excised osteophytes can also recur over a period of time, without any symptoms. Therefore a retained osteophyte alone is probably not sufficient to cause symptoms. Case presentation We present a case of intermittent medial knee pain occurring post-primary total knee arthroplasty, in a patient who underwent several investigations over a period of 5 years. Radiographs showed an osteophyte in the postero-medial femur along with slight tibial component overhang which was normal for that knee implant design. The symptoms eventually settled with excision of only the osteophyte, without altering the tibial component. Conclusion A retained osteophyte alone, or tibial component overhang alone, did not seem to cause significant symptoms in our patient whose symptoms completely settled with excision of the osteophyte alone, without changing the tibial component. Therefore, it seems that the combination of retained osteophyte and tibial component overhang (tibia-femoral component size mismatch are detrimental and therefore best avoided. This report also emphasises the importance of meticulous osteophyte excision and avoiding tibial component overhang during knee arthroplasty.

  3. The Current Scenario of Curvilinear Architecture in Malaysia

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    Faridah Aduan

    2007-12-01

    Full Text Available The Bilbao Effect incorporates itself into numerous iconic buildings and grand design s of international architects such as Frank Gehry, Santiago Calatrava, Norman Foster, Renzo Piano, Phillip Cox and Toyo Ito who exploit curvilinear forms as their architectural language .Throughout the world, major events such as the Olympic Games have catalysed the implementation of curvilinear architecture while in Malaysia, the development of Putrajaya has provided opportunity for iconic forms, expressed in curvilinearity. The paper focuses on the current scenario of curvilinear architecture in Malaysia and its posit ion in the international arena. It strives to answer the question of 'How far have Malaysian architects gone in implementing curvilinear architecture?' This is done by first formulating a 'Taxonomy of Rigid Curvilinear Architectural Forms' based on the works of renowned international architects. The taxonomy constitutes the instrument for gauging the position of Malaysian architects. This is achieved by having the works of local architects mapped on to the taxonomy. The research findings indicate that the international architects have advanced by leaps and bounds ahead of their Malaysian counterparts in implementing curvilinear architecture. Several recommendations are proposed in order to narrow this gap .The paper focuses on column-free, rigid and permanent buildings completed from 1990 onwards .

  4. Inertial Focusing of Microparticles in Curvilinear Microchannels

    Science.gov (United States)

    Özbey, Arzu; Karimzadehkhouei, Mehrdad; Akgönül, Sarp; Gozuacik, Devrim; Koşar, Ali

    2016-12-01

    A passive, continuous and size-dependent focusing technique enabled by “inertial microfluidics”, which takes advantage of hydrodynamic forces, is implemented in this study to focus microparticles. The objective is to analyse the decoupling effects of inertial forces and Dean drag forces on microparticles of different sizes in curvilinear microchannels with inner radius of 800 μm and curvature angle of 280°, which have not been considered in the literature related to inertial microfluidics. This fundamental approach gives insight into the underlying physics of particle dynamics and offers continuous, high-throughput, label-free and parallelizable size-based particle separation. Our design allows the same footprint to be occupied as straight channels, which makes parallelization possible with optical detection integration. This feature is also useful for ultrahigh-throughput applications such as flow cytometers with the advantages of reduced cost and size. The focusing behaviour of 20, 15 and 10 μm fluorescent polystyrene microparticles was examined for different channel Reynolds numbers. Lateral and vertical particle migrations and the equilibrium positions of these particles were investigated in detail, which may lead to the design of novel microfluidic devices with high efficiency and high throughput for particle separation, rapid detection and diagnosis of circulating tumour cells with reduced cost.

  5. Extracting roads and curvilinear bands with weak and broken boundaries

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    Zhou, Shaoguang; Li, Jinhui

    2008-12-01

    In so far as geometric shape is concerned a curvilinear band is very similar to a road segment. Roads may be regarded as a particular type of curvilinear bands. Many methods have been developed for extracting such targets, some of which are based on edge information. It is very difficult to extract roads and curvilinear bands with no clear and continuous boundaries using existing algorithms. To mitigate this problem a new strategy is presented in this paper. Edge lines are detected by means of an improved Burns' method and Dynamic Programming. Target segments are then formed by matching these edge lines. Connecting the obtained segments produces the final results. Experiments prove the efficiency of the proposed method while being applied to extract complicated roads and curvilinear bands in different kinds of images.

  6. AN ADAPTIVE NONMONOTONIC TRUST REGION METHOD WITH CURVILINEAR SEARCHES

    Institute of Scientific and Technical Information of China (English)

    Qun-yan Zhou; Wen-yu Sun

    2006-01-01

    In this paper, an algorithm for unconstrained optimization that employs both trust region techniques and curvilinear searches is proposed. At every iteration, we solve the trust region subproblem whose radius is generated adaptively only once. Nonmonotonic backtracking curvilinear searches are performed when the solution of the subproblem is unacceptable. The global convergence and fast local convergence rate of the proposed algorithms are established under some reasonable conditions. The results of numerical experiments are reported to show the effectiveness of the proposed algorithms.

  7. Exploring curvilinearity through fractional polynomials in management research

    OpenAIRE

    Nikolaeva, R.; Bhatnagar, A.; Ghose, S

    2015-01-01

    Imprecise theories do not give enough guidelines for empirical analyses. A paradigmatic shift from linear to curvilinear relationships is necessary to advance management theories. Within the framework of the abductive generation of theories, the authors present a data exploratory technique for the identification of functional relationships between variables. Originating in medical research, the method uses fractional polynomials to test for alternative curvilinear relationships. It is a compr...

  8. NONMONOTONE PRECONDITIONAL CURVILINEAR PATH ALGORITHMS FOR UNCONSTRAINED OPTIMIZATION

    Institute of Scientific and Technical Information of China (English)

    朱德通

    2003-01-01

    This paper presents nonmonotonic quasi-Newton algorithms via two pre-conditional curvilinear paths, the preconditional modified gradient path and the precon-ditional optimal path, for unconstrained optimization problem. We employ the stableBunch-Parlett factorization method to form two curvilinear paths very easily. Thenonmonotone criterion is used to speed up the convergence progress in the contoursof objective function with large curvature. Theoretical analyses are given which provethat the proposed algorithms are globally convergent and have a local superlinear con-vergence rate under some reasonable conditions. The results of numerical experimentsare reported to show the effectiveness of the proposed algorithms.

  9. Crucial role of synovial lining macrophages in the promotion of transforming growth factor beta-mediated osteophyte formation.

    NARCIS (Netherlands)

    Lent, P.L.E.M. van; Blom, A.B.; Kraan, P.M. van der; Holthuysen, A.E.M.; Vitters, E.L.; Rooijen, N. van; Smeets, R.L.L.; Nabbe, K.C.A.M.; Berg, W.B. van den

    2004-01-01

    OBJECTIVE: To investigate in vivo and in vitro whether macrophages have an intermediate role in transforming growth factor beta (TGFbeta)-induced osteophyte formation. METHODS: In vivo, synovial lining macrophages were selectively depleted by injection of clodronate-laden liposomes 7 days prior to i

  10. Evidence for curvilinear interpolation from dot alignment judgements

    NARCIS (Netherlands)

    van Assen, MA; Vos, PG

    1999-01-01

    Visual interpolation between dots responsible for rectilinear versus curvilinear contour interpretation was examined with the psychophysical forced directional response (FDR) paradigm. Regular four-dot polygon segments, together with a target dot, were presented to the subjects for 150 ms. Subjects

  11. Curvilinear shapes and the snake detection hypothesis : An ERP study

    NARCIS (Netherlands)

    Van Strien, Jan W; Christiaans, Gerwin; Franken, Ingmar H A; Huijding, Jorg

    2016-01-01

    Consistent with the snake detection hypothesis, previous ERP studies have established a larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Here, we examined to what extent the curvilinear shape of the snake's body drives the l

  12. Formal Education, Eminence, and Dogmatism: The Curvilinear Relationship.

    Science.gov (United States)

    Simonton, Dean Keith

    The relationship between formal education and creativity was investigated in two studies. A reanalysis of Cox's (1926) 301 geniuses indicated that achieved eminence of creators is a curvilinear inverted-U function of formal education. Secondly, a study of 33 American presidents found that dogmatism (i.e., idealistic inflexibility) is a curvilinear…

  13. A novel curvilinear approach for prostate seed implantation

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Tarun K.; Dicker, Adam P.; Hutapea, Parsaoran; Darvish, Kurosh; Yu Yan [Department of Radiation Oncology, Leo Jenkins Cancer Center, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Mechanical Engineering, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States)

    2012-04-15

    Purpose: A new technique called ''curvilinear approach'' for prostate seed implantation has been proposed. The purpose of this study is to evaluate the dosimetric benefit of curvilinear distribution of seeds for low-dose-rate (LDR) prostate brachytherapy. Methods: Twenty LDR prostate brachytherapy cases planned intraoperatively with VariSeed planning system and I-125 seeds were randomly selected as reference rectilinear cases. All the cases were replanned by using curved-needle approach keeping the same individual source strength and the volume receiving 100% of prescribed dose 145 Gy (V{sub 100}). Parameters such as number of needles, seeds, and the dose coverage of the prostate (D{sub 90}, V{sub 150}, V{sub 200}), urethra (D{sub 30}, D{sub 10}) and rectum (D{sub 5}, V{sub 100}) were compared for the rectilinear and the curvilinear methods. Statistical significance was assessed using two-tailed student's t-test. Results: Reduction of the required number of needles and seeds in curvilinear method were 30.5% (p < 0.001) and 11.8% (p < 0.49), respectively. Dose to the urethra was reduced significantly; D{sub 30} reduced by 10.1% (p < 0.01) and D{sub 10} reduced by 9.9% (p < 0.02). Reduction in rectum dose D{sub 5} was 18.5% (p < 0.03) and V{sub 100} was also reduced from 0.93 cc in rectilinear to 0.21 cc in curvilinear (p < 0.001). Also the V{sub 150} and V{sub 200} coverage of prostate reduced by 18.8% (p < 0.01) and 33.9% (p < 0.001), respectively. Conclusions: Significant improvement in the relevant dosimetric parameters was observed in curvilinear needle approach. Prostate dose homogeneity (V{sub 150}, V{sub 200}) improved while urethral dose was reduced, which might potentially result in better treatment outcome. Reduction in rectal dose could potentially reduce rectal toxicity and complications. Reduction in number of needles would minimize edema and thereby could improve postimplant urinary incontinence. This study indicates that the

  14. Proximal tibial osteophytes and their relationship with the height of the tibial spines of the intercondylar eminence: paleopathological study

    Energy Technology Data Exchange (ETDEWEB)

    Hayeri, Mohammad Reza [Children' s National Medical Center, Department of Radiology, Washington, DC (United States); Shiehmorteza, Masoud; Trudell, Debra J.; Resnick, Donald [University of California San Diego, Department of Radiology, San Diego, CA (United States); Hefflin, Tori [Museum of Man San Diego, San Diego, CA (United States)

    2010-09-15

    Tibial spiking (i.e., spurring of tibial spines), eburnation, and osteophytes are considered features of osteoarthritis. This investigation employed direct inspection of the medial and lateral tibial plateaus in paleopathological specimens to analyze the frequency and morphological features of osteoarthritis and to define any relationship between the size of osteophytes and that of the intercondylar tibial spines. A total of 35 tibial bone specimens were evaluated for the degree of osteoarthritis and presence of eburnation. Each plateau was also divided into four quadrants and the presence and size of bone outgrowths were recorded in each quadrant. The ''medial/lateral tibial intercondylar spine index'' for each specimen was calculated as follows: (medial/lateral intercondylar tibial spine height)/(anteroposterior width of the superior tibial surface). The relationships between medial and lateral tibial height indexes with the degree of osteoarthritis were then tested. Osteophytes were observed more frequently in the anterior quadrants of both tibial plateaus than in the posterior quadrants (29 vs 16 for the medial tibial plateau [p = 0.01] and 28 vs 20 for the lateral tibial plateau [p = 0.04]). Eburnation was seen more frequently in the posterior regions of both tibial plateaus than in the anterior regions (17 vs 5, p < 0.01). In specimens with no signs of osteoarthritis the lateral intercondylar tibial index was significantly lower than that in specimens with some degree of osteoarthritis (p = 0.02). The medial intercondylar tibial index of the specimens with no signs of osteoarthritis was not significantly different from that of the specimens with some degree of osteoarthritis (p = 0.45). There was a positive correlation between the lateral spine height index and the overall grading of osteoarthritis, (r = 0.6, p < 0.01). In the anteromedial and posteromedial quadrants of the lateral tibial plateau, the association between the lateral

  15. Reconstructing Wireframe Model of Curvilinear Objects from Three Orthographic Views

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An approach for reconstructing wireframe models of curvilinear objects from three orthographic views is discussed in this paper. The method for generating 3D conic edges from 2D projection conic curves is emphasized especially, which is the pivotal work for reconstructing curvilinear objects from three orthographic views. In order to generate 3D conic edges, a five-point method is firstly utilized to obtain the algebraic representations of all 2D-projection curves in each view, and then all algebraic forms are converted to the corresponding geometric forms analytically. Thus the locus of a 3D conic edge can be derived from the geometric forms of the relevant conic curves in three views. Finally, the wireframe model is created after eliminating all redundant elements generated in previous reconstruction process. The approach extends the range of objects to be reconstructed and imposes no restriction on the axis of the quadric surface.

  16. Explicit finite-difference lattice Boltzmann method for curvilinear coordinates.

    Science.gov (United States)

    Guo, Zhaoli; Zhao, T S

    2003-06-01

    In this paper a finite-difference-based lattice Boltzmann method for curvilinear coordinates is proposed in order to improve the computational efficiency and numerical stability of a recent method [R. Mei and W. Shyy, J. Comput. Phys. 143, 426 (1998)] in which the collision term of the Boltzmann Bhatnagar-Gross-Krook equation for discrete velocities is treated implicitly. In the present method, the implicitness of the numerical scheme is removed by introducing a distribution function different from that being used currently. As a result, an explicit finite-difference lattice Boltzmann method for curvilinear coordinates is obtained. The scheme is applied to a two-dimensional Poiseuille flow, an unsteady Couette flow, a lid-driven cavity flow, and a steady flow around a circular cylinder. The numerical results are in good agreement with the results of previous studies. Extensions to other lattice Boltzmann models based on nonuniform meshes are also discussed.

  17. Vibration analysis and optimization of sandwich composite with curvilinear fibers

    Science.gov (United States)

    Honda, S.; Narita, Y.

    2016-09-01

    The present paper develops a shell element based on the refined zigzag theory (RZT) and applies it to the vibration analysis and optimization problem of the composite sandwich plate composed of CFRP skins and soft-cores. The RZT accepts large differences in layer stiffness, and requires less calculation effort than the layer-wise or three-dimensional theories. Numerical results revealed that the present method predicts vibration characteristics of composite sandwich plates with soft-core accurately. Then, shapes of reinforcing fibers in CFRP composite skins are optimized to maximize fundamental frequencies. As an optimizer, the particle swarm optimization (PSO) approach is employed since curvilinear fiber shapes are defined by continuous design variables. Obtained results showed that the composite sandwich with optimum curvilinear fiber shapes indicates higher fundamental frequencies compared with straight fibers.

  18. Distribution and length of osteophytes in the lumbar vertebrae and risk of rupture of abdominal aortic aneurysms: a study of dry bones from Chiang Mai, Thailand.

    Science.gov (United States)

    Chanapa, Patcharin; Yoshiyuki, Tohno; Mahakkanukrauh, Pasuk

    2014-09-01

    Vertebral osteophytes are a characteristic feature of intervertebral disc degeneration. In the lumbar spinal region, the two major structures in close proximity anterior to the spine are the inferior vena cava and the abdominal aorta, both of which have been reported to be affected by osteophytes. The purpose of this study was to determine the distribution, classification and lengths of osteophytes in the lumbar vertebrae. One hundred and eighty lumbar columns of 90 males and 90 females from Chiang Mai, Thailand, in the age range 15 to 96 years (mean age, 63 years) were collected. The measuring length of osteophytes was assessed on vertebral body and articular facet. Statistical analysis was performed by descriptive analysis, chi-square and Pearson Correlation. Lumbar osteophytes were presented in 175 specimens (97.2%), 88 males and 87 females. The highest frequency was at L4, most were on the superior, inferior surface of body and articular facet (39.7%, 38.4%, and 22%), respectively. The greatest mean length was 3.47±2.21 mm at L5, and the longest length of anterior superior surface of body was 28.56 mm. The osteophyte length was significantly correlated directly with age (Ptraction. It can be proposed that the abdominal aorta could be damaged, especially a risk of rupture of abdominal aortic aneurysm.

  19. Accurate measurement of curvilinear shapes by Virtual Image Correlation

    OpenAIRE

    Semin, B; Auradou, H.; François, M.L.M.

    2011-01-01

    Abstract The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C? (and not a finite set of locations or pixels) thus curv...

  20. Electron as the eigenstate of curvilinear space with torsion

    Science.gov (United States)

    Sharin, Yu. A.

    1998-05-01

    Ideas previously enunciated by the author about the physical interpretation of curvilinear space with torsion are developed. With the new equations describing the eigenstates of such a space, the static centrosymmetric solution for gravitational and electric fields can be made consistent with the Newton and Coulomb laws. The asymptotic behavior of the axisymmetric solution at infinity is studied. The gyromagnetic ratio obtained is characteristic of the electron.

  1. Height among Women is Curvilinearly Related to Life History Strategy

    Directory of Open Access Journals (Sweden)

    Abraham P. Buunk

    2009-10-01

    Full Text Available It was hypothesized that women of medium height would show a more secure, long-term mating pattern characterized by less jealousy, less intrasexual competition and a “slower” life history strategy. In three samples of female undergraduate students clear support was found for these hypotheses. In Study 1, among 120 participants, height was curvilinearly related to well-established measures of possessive and reactive jealousy, with women of medium height being less jealous than tall as well as short women. In Study 2, among 40 participants, height was curvilinearly related to intrasexual competition, with women of medium height being less competitive towards other women than tall as well as short women. In Study 3, among 299 participants, height was curvilinearly related to the Mini-K, a well-validated measure of “slower” life history strategy, with women of medium height having a slower life history strategy than tall as well as short women. The results suggest that women of medium height tend to follow a different mating strategy than either tall or short women. Various explanations and implications of these results are discussed.

  2. The curvilinear effect of work engagement on employees' turnover intentions.

    Science.gov (United States)

    Caesens, Gaëtane; Stinglhamber, Florence; Marmier, Virginie

    2016-04-01

    Numerous studies have shown the positive consequences of work engagement for both organisations and employees experiencing it. For instance, research has demonstrated that work-engaged employees have lower levels of turnover intentions than non-engaged employees. However, in this research, we examined whether there is a dark side of work engagement. More precisely, we investigated whether the relationship between work engagement and employees' turnover intentions might be non-linear. Based on two different samples, our results indicated that the relationship between work engagement and employees' turnover intentions is curvilinear. The theoretical and practical implications of these results are discussed.

  3. A new osteophyte segmentation method with applications to an anterior cruciate ligament transection rabbit femur model via micro-CT imaging

    Science.gov (United States)

    Liang, G.; Elkins, J. M.; Coimbra, A.; Duong, L. T.; Williams, D. S.; Sonka, M.; Saha, P. K.

    2010-03-01

    Osteophyte is an additional bony growth on a normal bone surface limiting or stopping motion in a deteriorating joint. Detection and quantification of osteophytes from CT images is helpful in assessing disease status as well as treatment and surgery planning. However, it is difficult to segment osteophytes from healthy bones using simple thresholding or edge/texture features in CT imaging. Here, we present a new method, based on active shape model (ASM), to solve this problem and evaluate its application to ex vivo μCT images in an ACLT rabbit femur model. The common idea behind most ASM based segmentation methods is to first build a parametric shape model from a training dataset and during application, find a shape instance from the model that optimally fits to target image. However, it poses a fundamental difficulty for the current application because a diseased bone shape is significantly altered at regions with osteophyte deposition misguiding an ASM method that eventually leads to suboptimum segmentation results. Here, we introduce a new partial ASM method that uses bone shape over healthy regions and extrapolate its shape over diseased region following the underlying shape model. Once the healthy bone region is detected, osteophyte is segmented by subtracting partial-ASM derived shape from the overall diseased shape. Also, a new semi-automatic method is presented in this paper for efficiently building a 3D shape model for rabbit femur. The method has been applied to μCT images of 2-, 4-, and 8-week post ACLT and sham-treated rabbit femurs and results of reproducibility and sensitivity analyses of the new osteophyte segmentation method are presented.

  4. The semi-Lagrangian method on curvilinear grids

    Directory of Open Access Journals (Sweden)

    Hamiaz Adnane

    2016-09-01

    Full Text Available We study the semi-Lagrangian method on curvilinear grids. The classical backward semi-Lagrangian method [1] preserves constant states but is not mass conservative. Natural reconstruction of the field permits nevertheless to have at least first order in time conservation of mass, even if the spatial error is large. Interpolation is performed with classical cubic splines and also cubic Hermite interpolation with arbitrary reconstruction order of the derivatives. High odd order reconstruction of the derivatives is shown to be a good ersatz of cubic splines which do not behave very well as time step tends to zero. A conservative semi-Lagrangian scheme along the lines of [2] is then described; here conservation of mass is automatically satisfied and constant states are shown to be preserved up to first order in time.

  5. Temporal mammogram image registration using optimized curvilinear coordinates.

    Science.gov (United States)

    Abdel-Nasser, Mohamed; Moreno, Antonio; Puig, Domenec

    2016-04-01

    Registration of mammograms plays an important role in breast cancer computer-aided diagnosis systems. Radiologists usually compare mammogram images in order to detect abnormalities. The comparison of mammograms requires a registration between them. A temporal mammogram registration method is proposed in this paper. It is based on the curvilinear coordinates, which are utilized to cope both with global and local deformations in the breast area. Temporal mammogram pairs are used to validate the proposed method. After registration, the similarity between the mammograms is maximized, and the distance between manually defined landmarks is decreased. In addition, a thorough comparison with the state-of-the-art mammogram registration methods is performed to show its effectiveness.

  6. Optimization of Curvilinear Tracing Applied to Solar Physics and Biophysics

    Directory of Open Access Journals (Sweden)

    Markus J. Aschwanden

    2013-07-01

    Full Text Available We developed an automated pattern recognition code that is particularly well suited to extract one-dimensional curvilinear features from two-dimensional digital images. A former version of this Oriented Coronal Curved Loop Tracing (OCCULT code was applied to spacecraft images of magnetic loops in the solar corona, recorded with the NASA spacecraft, Transition Region And Coronal Explorer (TRACE, in extreme ultra-violet wavelengths. Here, we apply an advanced version of this code (OCCULT-2, also, to similar images from the Solar Dynamics Observatory (SDO, to chromospheric H-α images obtained with the Swedish Solar Telescope (SST and to microscopy images of microtubule filaments in live cells in biophysics. We provide a full analytical description of the code, optimize the control parameters and compare the automated tracing with visual/manual methods. The traced structures differ by up to 16 orders of magnitude in size, which demonstrates the universality of the tracing algorithm.

  7. Dendritic spine detection using curvilinear structure detector and LDA classifier.

    Science.gov (United States)

    Zhang, Yong; Zhou, Xiaobo; Witt, Rochelle M; Sabatini, Bernardo L; Adjeroh, Donald; Wong, Stephen T C

    2007-06-01

    Dendritic spines are small, bulbous cellular compartments that carry synapses. Biologists have been studying the biochemical pathways by examining the morphological and statistical changes of the dendritic spines at the intracellular level. In this paper a novel approach is presented for automated detection of dendritic spines in neuron images. The dendritic spines are recognized as small objects of variable shape attached or detached to multiple dendritic backbones in the 2D projection of the image stack along the optical direction. We extend the curvilinear structure detector to extract the boundaries as well as the centerlines for the dendritic backbones and spines. We further build a classifier using Linear Discriminate Analysis (LDA) to classify the attached spines into valid and invalid types to improve the accuracy of the spine detection. We evaluate the proposed approach by comparing with the manual results in terms of backbone length, spine number, spine length, and spine density.

  8. Reconstruction method for curvilinear structures from two views

    Science.gov (United States)

    Hoffmann, Matthias; Brost, Alexander; Jakob, Carolin; Koch, Martin; Bourier, Felix; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive interventions often involve tools of curvilinear shape like catheters and guide-wires. If the camera parameters of a fluoroscopic system or a stereoscopic endoscope are known, a 3-D reconstruction of corresponding points can be computed by triangulation. Manual identification of point correspondences is time consuming, but there exist methods that automatically select corresponding points along curvilinear structures. The focus here is on the evaluation of a recent published method for catheter reconstruction from two views. A previous evaluation of this method using clinical data yielded promising results. For that evaluation, however, no 3-D ground truth data was available such that the error could only be estimated using the forward-projection of the reconstruction. In this paper, we present a more extensive evaluation of this method based on both clinical and phantom data. For the evaluation using clinical images, 36 data sets and two different catheters were available. The mean error found when reconstructing both catheters was 0.1mm +/- 0.1mm. To evaluate the error in 3-D, images of a phantom were acquired from 13 different angulations. For the phantom, A 3D C-arm CT voxel data set of the phantom was also available. A reconstruction error was calculated by comparing the triangulated 3D reconstruction result to the 3D voxel data set. The evaluation yielded an average error of 1.2mm +/- 1.2mm for the circumferential mapping catheter and 1.3mm +/- 1.0mm for the ablation catheter.

  9. TGF-ß in osteoarthritis : age-related loss of protective function in cartilage and player in osteophyte formation and synovial fibrosis

    NARCIS (Netherlands)

    Blaney Davidson, Esmeralda Nicole

    2007-01-01

    Osteoarthritis (OA) is a common joint disease affecting mainly the elderly population. In younger people it can be caused by joint trauma or congenital afflictions. OA is characterized by cartilage damage, synovial fibrosis and osteophyte formation. TGF-ß is a growth factor that is a potent inducer

  10. Profiles for voltage-activated currents are multiphasic, not curvilinear

    CERN Document Server

    Nissen, Per

    2016-01-01

    Data for voltage-activation of a potassium channel (Matulef et al. Proc Natl Acad Sci USA 110: 17886-17891. 2013) were, as conventionally done, fitted by the authors by a Boltzmann function, i.e. by a curvilinear profile. Reanalysis of the data reveals however that this interpretation must be rejected in favor of a multiphasic profile, a series of straight lines separated by discontinuous transitions, quite often in the form of noncontiguities (jumps). In contrast to the generally very poor fits to the Boltzmann profiles, the fits to multiphasic profiles are very good. (For the four replicates, the average deviations from the Boltzmann curves were 10- to 100-fold larger than the deviations from the multiphasic profiles.) The difference in the median values was statistically highly significant, P<0.001 in most cases. For the mean values the deviations from the Boltzmann curve were 20-fold larger than the deviations from the multiphasic profile, and the difference in the median values was also highly signifi...

  11. Accurate measurement of curvilinear shapes by Virtual Image Correlation

    Science.gov (United States)

    Semin, B.; Auradou, H.; François, M. L. M.

    2011-10-01

    The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C∞ (and not a finite set of locations or pixels) thus curvatures and slopes, often of great interest in science, are given with good confidence. The proposed Virtual Image Correlation (VIC) method uses a virtual beam, an image which consists in a lateral expansion of the curve with a bell-shaped gray level. This figure is deformed until it fits the best the physical image with a method issued from the Digital Image Correlation method in use in solid mechanics. The precision of the identification is studied in a benchmark and successfully compared to two state-of-the-art methods. Three practical examples are given: a bar bending under its own weight, a thin fiber transported by a flow within a fracture and a thermal front. The first allows a comparison with theoretical solution, the second shows the ability of the method to deal with complex shapes and crossings and the third deals with ill-defined image.

  12. The curvilinear relationship between state neuroticism and momentary task performance.

    Directory of Open Access Journals (Sweden)

    Jonas Debusscher

    Full Text Available A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity. In one, results showed that under high work pressure, the state neuroticism-task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism-momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands.

  13. The curvilinear relationship between state neuroticism and momentary task performance.

    Science.gov (United States)

    Debusscher, Jonas; Hofmans, Joeri; De Fruyt, Filip

    2014-01-01

    A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism-task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism-momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands.

  14. Guarding curvilinear art galleries with vertex or point guards

    CERN Document Server

    Karavelas, Menelaos I

    2008-01-01

    One of the earliest and most well known problems in computational geometry is the so-called art gallery problem. The goal is to compute the minimum possible number guards placed on the vertices of a simple polygon in such a way that they cover the interior of the polygon. In this paper we consider the problem of guarding an art gallery which is modeled as a polygon with curvilinear walls. Our main focus is on polygons the edges of which are convex arcs pointing towards the exterior or interior of the polygon (but not both), named piecewise-convex and piecewise-concave polygons. We prove that, in the case of piecewise-convex polygons, if we only allow vertex guards, $\\lfloor\\frac{4n}{7}\\rfloor-1$ guards are sometimes necessary, and $\\lfloor\\frac{2n}{3}\\rfloor$ guards are always sufficient. Moreover, an $O(n\\log{}n)$ time and $O(n)$ space algorithm is described that produces a vertex guarding set of size at most $\\lfloor\\frac{2n}{3}\\rfloor$. When we allow point guards the afore-mentioned lower bound drops down ...

  15. BSIRT: a block-iterative SIRT parallel algorithm using curvilinear projection model.

    Science.gov (United States)

    Zhang, Fa; Zhang, Jingrong; Lawrence, Albert; Ren, Fei; Wang, Xuan; Liu, Zhiyong; Wan, Xiaohua

    2015-03-01

    Large-field high-resolution electron tomography enables visualizing detailed mechanisms under global structure. As field enlarges, the distortions of reconstruction and processing time become more critical. Using the curvilinear projection model can improve the quality of large-field ET reconstruction, but its computational complexity further exacerbates the processing time. Moreover, there is no parallel strategy on GPU for iterative reconstruction method with curvilinear projection. Here we propose a new Block-iterative SIRT parallel algorithm with the curvilinear projection model (BSIRT) for large-field ET reconstruction, to improve the quality of reconstruction and accelerate the reconstruction process. We also develop some key techniques, including block-iterative method with the curvilinear projection, a scope-based data decomposition method and a page-based data transfer scheme to implement the parallelization of BSIRT on GPU platform. Experimental results show that BSIRT can improve the reconstruction quality as well as the speed of the reconstruction process.

  16. Use of generalized curvilinear coordinate systems in electromagnetic and hybrid codes

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D.W. [Univ. of Alaska, Fairbanks, AK (United States)

    1995-07-01

    The author develops a code to simulate the dynamics in the magnetosphere system. The calculation involves a single level, structured, curvilinear 2D mesh. The mesh density is varied to support regions which demand higher resolution.

  17. Innovative design of composite structures: The use of curvilinear fiber format in composite structure design

    Science.gov (United States)

    Hyer, M. W.; Charette, R. F.

    1990-01-01

    The gains in structural efficiency are investigated that can be achieved by aligning the fibers in some or all of the layers in a laminate with the principal stress directions in those layers. The name curvilinear fiber format is given to this idea. The problem studied is a plate with a central circular hole subjected to a uniaxial tensile load. An iteration scheme is used to find the fiber directions at each point in the laminate. Two failure criteria are used to evaluate the tensile load capacity of the plates with a curvilinear format, and for comparison, counterpart plates with a conventional straightline fiber format. The curvilinear designs for improved tensile capacity are then checked for buckling resistance. It is concluded that gains in efficiency can be realized with the curvilinear format.

  18. High-Order Curvilinear Finite Element Methods for Lagrangian Hydrodynamics [High Order Curvilinear Finite Elements for Lagrangian Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Dobrev, Veselin A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kolev, Tzanio V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rieben, Robert N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-09-20

    The numerical approximation of the Euler equations of gas dynamics in a movingLagrangian frame is at the heart of many multiphysics simulation algorithms. Here, we present a general framework for high-order Lagrangian discretization of these compressible shock hydrodynamics equations using curvilinear finite elements. This method is an extension of the approach outlined in [Dobrev et al., Internat. J. Numer. Methods Fluids, 65 (2010), pp. 1295--1310] and can be formulated for any finite dimensional approximation of the kinematic and thermodynamic fields, including generic finite elements on two- and three-dimensional meshes with triangular, quadrilateral, tetrahedral, or hexahedral zones. We discretize the kinematic variables of position and velocity using a continuous high-order basis function expansion of arbitrary polynomial degree which is obtained via a corresponding high-order parametric mapping from a standard reference element. This enables the use of curvilinear zone geometry, higher-order approximations for fields within a zone, and a pointwise definition of mass conservation which we refer to as strong mass conservation. Moreover, we discretize the internal energy using a piecewise discontinuous high-order basis function expansion which is also of arbitrary polynomial degree. This facilitates multimaterial hydrodynamics by treating material properties, such as equations of state and constitutive models, as piecewise discontinuous functions which vary within a zone. To satisfy the Rankine--Hugoniot jump conditions at a shock boundary and generate the appropriate entropy, we introduce a general tensor artificial viscosity which takes advantage of the high-order kinematic and thermodynamic information available in each zone. Finally, we apply a generic high-order time discretization process to the semidiscrete equations to develop the fully discrete numerical algorithm. Our method can be viewed as the high-order generalization of the so-called staggered

  19. An issue encountered in solving problems in electricity and magnetism: curvilinear coordinates

    Science.gov (United States)

    Gülçiçek, Çağlar; Damlı, Volkan

    2016-11-01

    In physics lectures on electromagnetic theory and mathematical methods, physics teacher candidates have some difficulties with curvilinear coordinate systems. According to our experience, based on both in-class interactions and teacher candidates’ answers in test papers, they do not seem to have understood the variables in curvilinear coordinate systems very well. For this reason, the problems that physics teacher candidates have with variables in curvilinear coordinate systems have been selected as a study subject. The aim of this study is to find the physics teacher candidates’ problems with determining the variables of drawn shapes, and problems with drawing shapes based on given variables in curvilinear coordinate systems. Two different assessment tests were used in the study to achieve this aim. The curvilinear coordinates drawing test (CCDrT) was used to discover their problems related to drawing shapes, and the curvilinear coordinates detection test (CCDeT) was used to find out about problems related to determining variables. According to the findings obtained from both tests, most physics teacher candidates have problems with the ϕ variable, while they have limited problems with the r variable. Questions that are mostly answered wrongly have some common properties, such as value. According to inferential statistics, there is no significant difference between the means of the CCDeT and CCDrT scores. The mean of the CCDeT scores is only 4.63 and the mean of the CCDrT is only 4.66. Briefly, we can say that most physics teacher candidates have problems with drawing a shape using the variables of curvilinear coordinate systems or in determining the variables of drawn shapes. Part of this study was presented at the XI. National Science and Mathematics Education Congress (UFBMEK) in 2014.

  20. Innovative design of composite structures: Further studies in the use of a curvilinear fiber format to improve structural efficiency

    Science.gov (United States)

    Hyer, Michael W.; Charette, Robert F.

    1988-01-01

    Further studies to determine the potential for using a curvilinear fiber format in the design of composite laminates are reported. The curvilinear format is in contrast to the current practice of having the fibers aligned parallel to each other and in a straight line. The problem of a plate with a central circular hole is used as a candidate problem for this study. The study concludes that for inplane tensile loading the curvilinear format is superior. The limited results to date on compression buckling loads indicate that the curvilinear designs are poorer in resistant buckling. However, for the curvilinear design of interest, the reduction in buckling load is minimal and so overall there is a gain in considering the curvilinear design.

  1. Innovative design of composite structures: Use of curvilinear fiber format to improve structural efficiency

    Science.gov (United States)

    Hyer, M. W.; Charette, R. F.

    1987-01-01

    To increase the effectiveness and efficiency of fiber-reinforced materials, the use of fibers in a curvilinear rather than the traditional straightline format is explored. The capacity of a laminated square plate with a central circular hole loaded in tension is investigated. The orientation of the fibers is chosen so that the fibers in a particular layer are aligned with the principle stress directions in that layer. Finite elements and an iteration scheme are used to find the fiber orientation. A noninteracting maximum strain criterion is used to predict load capacity. The load capacities of several plates with different curvilinear fibers format are compared with the capacities of more conventional straightline format designs. It is found that the most practical curvilinear design sandwiches a group of fibers in a curvilinear format between a pair of +/-45 degree layers. This design has a 60% greater load capacity than a conventional quasi-isotropic design with the same number of layers. The +/-45 degree layers are necessary to prevent matrix cracking in the curvilinear layers due to stresses perpendicular to the fibers in those layers. Greater efficiencies are achievable with composite structures than now realized.

  2. Innovative design of composite structures: The use of curvilinear fiber format in structural design of composites

    Science.gov (United States)

    Charette, R. F.; Hyer, M. W.

    1990-01-01

    The influence is investigated of a curvilinear fiber format on load carrying capacity of a layered fiber reinforced plate with a centrally located hole. A curvilinear fiber format is descriptive of layers in a laminate having fibers which are aligned with the principal stress directions in those layers. Laminates of five curvilinear fiber format designs and four straightline fiber format designs are considered. A quasi-isotropic laminate having a straightline fiber format is used to define a baseline design for comparison with the other laminate designs. Four different plate geometries are considered and differentiated by two values of hole diameter/plate width equal to 1/6 and 1/3, and two values of plate length/plate width equal to 2 and 1. With the plates under uniaxial tensile loading on two opposing edges, alignment of fibers in the curvilinear layers with the principal stress directions is determined analytically by an iteration procedure. In-plane tensile load capacity is computed for all of the laminate designs using a finite element analysis method. A maximum strain failure criterion and the Tsai-Wu failure criterion are applied to determine failure loads and failure modes. Resistance to buckling of the laminate designs to uniaxial compressive loading is analyzed using the commercial code Engineering Analysis Language. Results indicate that the curvilinear fiber format laminates have higher in-plane tensile load capacity and comparable buckling resistance relative to the straightline fiber format laminates.

  3. Innovative design of composite structures: Design, manufacturing, and testing of plates utilizing curvilinear fiber trajectories

    Science.gov (United States)

    Hyer, M. W.; Rust, R. J.; Waters, W. A., Jr.

    1994-01-01

    As a means of improving structural design, the concept of fabricating flat plates containing holes by incorporating curvilinear fiber trajectories to transmit loads around the hole is studied. In the present discussion this concept is viewed from a structural level, where access holes, windows, doors, and other openings are of significant size. This is opposed to holes sized for mechanical fasteners. Instead of cutting the important load-bearing fibers at the hole edge, as a conventional straightline design does, the curvilinear design preserves the load-bearing fibers by orienting them in smooth trajectories around the holes, their loading not ending abruptly at the hole edge. Though the concept of curvilinear fiber trajectories has been studied before, attempts to manufacture and test such plates have been limited. This report describes a cooperative effort between Cincinnati Milacron Inc., NASA Langley Research Center, and Virginia Polytechnic Institute and State University to design, manufacture, and test plates using the curvilinear fiber trajectory concept. The paper discusses details of the plate design, details of the manufacturing, and a summary of results from testing the plates with inplane compressive buckling loads and tensile loads. Comparisons between the curvilinear and conventional straightline fiber designs based on measurements and observation are made. Failure modes, failure loads, strains, deflections, and other key responses are compared.

  4. 3-T MRI assessment of osteophyte formation in patients with unilateral anterior cruciate ligament injury and reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Stephanie [Department of Radiology, Trauma Center Murnau, Murnau (Germany); Augat, Peter [Trauma Center Murnau and Paracelsus Medical University, Institute of Biomechanics, Murnau (Germany); Atzwanger, Joerg; Hergan, Klaus [University Hospital Salzburg, Paracelsus Medical University, Department of Radiology, Salzburg (Austria)

    2012-12-15

    To define the number and distribution of osteophytes (OPs) in bilateral knee MRI (magnetic resonance imaging) of patients with unilateral anterior cruciate ligament (ACL) rupture. Bilateral knee MRIs of 20 patients with unilateral ACL rupture and reconstruction were retrospectively analyzed for OPs. OPs were graded following the KOSS (knee OA scoring system) classification and their compartmental distribution was assessed following the WORMS (Whole-Organ Magnetic Resonance Imaging Score) classification. All examined knees revealed OPs. Knees with ACL rupture showed significant (p < 0.001) higher total numbers of OPs (mean 11.6; SD {+-} 4.4) than knees with intact ACL (mean 5.1; SD {+-} 2.3). Knees with ACL rupture showed increased OP formation in all knee compartments with predominance of marginal OPs in the lateral femorotibial compartment especially on the tibia. Our results show that after knee injury with ACL rupture and reconstruction, all knee compartments were involved in post-traumatic increase of OP formation. The most affected compartment was the lateral femorotibial compartment on the tibial side. (orig.)

  5. Approximate solutions of non-linear circular orbit relative motion in curvilinear coordinates

    Science.gov (United States)

    Bombardelli, Claudio; Gonzalo, Juan Luis; Roa, Javier

    2017-01-01

    A compact, time-explicit, approximate solution of the highly non-linear relative motion in curvilinear coordinates is provided under the assumption of circular orbit for the chief spacecraft. The rather compact, three-dimensional solution is obtained by algebraic manipulation of the individual Keplerian motions in curvilinear, rather than Cartesian coordinates, and provides analytical expressions for the secular, constant and periodic terms of each coordinate as a function of the initial relative motion conditions or relative orbital elements. Numerical test cases are conducted to show that the approximate solution can be effectively employed to extend the classical linear Clohessy-Wiltshire solution to include non-linear relative motion without significant loss of accuracy up to a limit of 0.4-0.45 in eccentricity and 40-45° in relative inclination for the follower. A very simple, quadratic extension of the classical Clohessy-Wiltshire solution in curvilinear coordinates is also presented.

  6. Approximate solutions of non-linear circular orbit relative motion in curvilinear coordinates

    Science.gov (United States)

    Bombardelli, Claudio; Gonzalo, Juan Luis; Roa, Javier

    2016-07-01

    A compact, time-explicit, approximate solution of the highly non-linear relative motion in curvilinear coordinates is provided under the assumption of circular orbit for the chief spacecraft. The rather compact, three-dimensional solution is obtained by algebraic manipulation of the individual Keplerian motions in curvilinear, rather than Cartesian coordinates, and provides analytical expressions for the secular, constant and periodic terms of each coordinate as a function of the initial relative motion conditions or relative orbital elements. Numerical test cases are conducted to show that the approximate solution can be effectively employed to extend the classical linear Clohessy-Wiltshire solution to include non-linear relative motion without significant loss of accuracy up to a limit of 0.4-0.45 in eccentricity and 40-45° in relative inclination for the follower. A very simple, quadratic extension of the classical Clohessy-Wiltshire solution in curvilinear coordinates is also presented.

  7. The movement kinematics of manipulator with elastic joints in the curvilinear coordinate system

    Directory of Open Access Journals (Sweden)

    A.A. Ghukasyan

    2007-09-01

    Full Text Available Movement kinematics of the multi-link manipulator with elastic joints in the curvilinear coordinate system is studied. Within the bounds of the linear theory of elasticity by generalized Lame matrix general expressions for speed and acceleration of the characteristic points of the links and manipulator handle are received. The received formulas allow to easily determine the kinematics of different constructions of the manipulators with elastic joints in the curvilinear coordinates. As an example movement velocity of a two-link manipulator with one elastic joint is determined in the cylindrical coordinate system.

  8. NEW BOUNDARY ELEMENT METHOD FOR TORSION PROBLEMS OF CYLINDER WITH CURVILINEAR CRACKS

    Institute of Scientific and Technical Information of China (English)

    WANG Yin-bang; LU Zi-zi

    2005-01-01

    The Saint-Venant torsion problems of a cylinder with curvilinear cracks were considered and reduced to solving the boundary integral equations only on cracks. Using the interpolation models for both singular crack tip elements and other crack linear elements, the boundary element formulas of the torsion rigidity and stress intensity factors were given. Some typical torsion problems of a cylinder involving a straight,kinked or curvilinear crack were calculated. The obtained results for the case of straight crack agree well with those given by using the Gauss-Chebyshev integration formulas,which demonstrates the validity and applicability of the present boundary element method.

  9. Social networks, personal values, and creativity: evidence for curvilinear and interaction effects.

    Science.gov (United States)

    Zhou, Jing; Shin, Shung Jae; Brass, Daniel J; Choi, Jaepil; Zhang, Zhi-Xue

    2009-11-01

    Taking an interactional perspective on creativity, the authors examined the influence of social networks and conformity value on employees' creativity. They theorized and found a curvilinear relationship between number of weak ties and creativity such that employees exhibited greater creativity when their number of weak ties was at intermediate levels rather than at lower or higher levels. In addition, employees' conformity value moderated the curvilinear relationship between number of weak ties and creativity such that employees exhibited greater creativity at intermediate levels of number of weak ties when conformity was low than when it was high. A proper match between personal values and network ties is critical for understanding creativity.

  10. Stability estimates for h-p spectral element methods for general elliptic problems on curvilinear domains

    NARCIS (Netherlands)

    Dutt, Pravir; Tomar, Satyendra

    2003-01-01

    In this paper we show that the h-p spectral element method developed in [3,8,9] applies to elliptic problems in curvilinear polygons with mixed Neumann and Dirichlet boundary conditions provided that the Babuska-Brezzi inf-sup conditions are satisfied. We establish basic stability estimates for a no

  11. Development and field validation of a 2DH curvilinear storm impact model

    NARCIS (Netherlands)

    Roelvink, D.; Stelling, G.; Hoonhout, B.M.; Risandi, J.; Jacobs, W.; Merli, D.

    2012-01-01

    The formulations of the 2DH process-based, nearshore morphological model XBeach were extended to allow for curvilinear grids using a finite volume approach. The formulations were tested for schematic cases such as a circular island and a field validation study was carried out for the case of storm e

  12. Incremental road discovery from aerial imagery using curvilinear spanning tree (CST) search

    Science.gov (United States)

    Wang, Guozhi; Huang, Yuchun; Xie, Rongchang; Zhang, Hongchang

    2016-10-01

    Robust detection of road network in aerial imagery is a challenging task since roads have different pavement texture, road-side surroundings, as well as grades. Roads of different grade have different curvilinear saliency in the aerial imagery. This paper is motivated to incrementally extract roads and construct the topology of the road network of aerial imagery from the higher-grade-first perspective. Inspired by the spanning tree technique, the proposed method starts from the robust extraction of the most salient road segment(s) of the road network, and incrementally connects segments of less saliency of curvilinear structure until all road segments in the network are extracted. The proposed algorithm includes: curvilinear path-based road morphological enhancement, extraction of road segments, and spanning tree search for the incremental road discovery. It is tested on a diverse set of aerial imagery acquired in the city and inter-city areas. Experimental results show that the proposed curvilinear spanning tree (CST) can detect roads efficiently and construct the topology of the road network effectively. It is promising for the change detection of the road network.

  13. Differential Parenting and Children's Behavioral Problems: Curvilinear Associations and Mother-Father Combined Effects

    Science.gov (United States)

    Meunier, Jean Christophe; Bisceglia, Rossana; Jenkins, Jennifer M.

    2012-01-01

    In this study the associations between mothers' and fathers' differential parenting and children's oppositional and emotional problems were examined. A curvilinear relationship between differential parenting and children's outcomes was hypothesized, as well as the combined effect of mothers' and fathers' parenting. Data came from a community…

  14. High Order Finite Difference Methods, Multidimensional Linear Problems and Curvilinear Coordinates

    Science.gov (United States)

    Nordstrom, Jan; Carpenter, Mark H.

    1999-01-01

    Boundary and interface conditions are derived for high order finite difference methods applied to multidimensional linear problems in curvilinear coordinates. The boundary and interface conditions lead to conservative schemes and strict and strong stability provided that certain metric conditions are met.

  15. The effect of culture on the curvilinear relationship between performance and turnover.

    Science.gov (United States)

    Sturman, Michael C; Shao, Lian; Katz, Jan H

    2012-01-01

    Although researchers have theorized that there exists a curvilinear relationship between job performance and voluntary turnover, their research has been tested in the United States or culturally similar Switzerland. Through a study of the performance-turnover relationship from a multinational service-oriented organization in 24 countries, we demonstrate that the general relationship between performance and turnover is similar across countries but the details of that relationship change across countries. Using 4 cultural dimensions--in-group collectivism, power distance, uncertainty avoidance, and performance orientation--we find that cultural factors alter the overall probability of voluntary turnover and influence the degree of curvilinearity in the performance-turnover relationship. Our findings have implications for research on the performance-turnover relationship, turnover research, and practice.

  16. Modeling of a Curvilinear Planar Crack with a Curvature-Dependent Surface Tension

    KAUST Repository

    Zemlyanova, A. Y.

    2012-01-01

    An approach to modeling fracture incorporating interfacial mechanics is applied to the example of a curvilinear plane strain crack. The classical Neumann boundary condition is augmented with curvature-dependent surface tension. It is shown that the considered model eliminates the integrable crack-tip stress and strain singularities of order 1/2 present in the classical linear fracture mechanics solutions, and also leads to the sharp crack opening that is consistent with empirical observations. Unlike for the case of a straight crack, for a general curvilinear crack some components of the stresses and the derivatives of the displacements may still possess weaker singularities of a logarithmic type. Generalizations of the present study that lead to complete removal of all crack-tip singularities, including logarithmic, are the subject of a future paper. © 2012 Society for Industrial and Applied Mathematics.

  17. 'Perfectly' curvilinear profiles for binding as determined by ITC may in fact be multiphasic

    CERN Document Server

    Nissen, Per

    2016-01-01

    In a structural analysis of the proteasome activator PafE in Mycobacterium tuberculosis, the binding of the activator or shorter constructs to the 20S proteasome core particle (20S CP) or derivatives was measured by isothermal titration calorimetry (Bai et al. Proc Natl Acad Sci USA 113: E1983-E1992. 2016). The data were fitted by the authors by nonlinear least squares to give curvilinear profiles that, at least in part, appear to fit the data very well. However, reanalysis of the data shows that the profiles are much better (P < 0.001) represented as multiphasic, i.e. by a series of straight lines separated by discontinuous transitions, often in the form jumps, than by the conventional curvilinear profiles.

  18. Numerical Calculation of 3—D TUrbulent Flow in Curvilinear Coordinate Systems with Nostaggered Grids

    Institute of Scientific and Technical Information of China (English)

    ZhangJingzhou; LiLiguo; 等

    1996-01-01

    The nonstaggered grids are adopted in this paper for solving the governing equations of flows in the curvilinear coordinate systems.The present paper demonstrates the basic reason and corresponding eliminating method for the pressure oscillation,and deduces the corrected expressions for the curvilinear velocity components in which and additional term representing the difference between the 1-δ and 2-δ difference values for the pressure gradient appears.Thus if an oscillatory pressure filed were arisen,the magnitude of this term would be large and would act to remove the oscillation;whereas for nonoscillatory field the magnitude of this term remains small.As examination for the numerical method 3-D turbulent flow in a square duct with 90° bend and 3-D turbulent mixing low in a lobed-mixer were calculatied respectively.The numerical results are satisfactory.

  19. Substance use disorder counselors' job performance and turnover after 1 year: linear or curvilinear relationship?

    Science.gov (United States)

    Laschober, Tanja C; de Tormes Eby, Lillian Turner

    2013-07-01

    The main goals of the current study were to investigate whether there are linear or curvilinear relationships between substance use disorder counselors' job performance and actual turnover after 1 year utilizing four indicators of job performance and three turnover statuses (voluntary, involuntary, and no turnover as the reference group). Using longitudinal data from 440 matched counselor-clinical supervisor dyads, results indicate that overall, counselors with lower job performance are more likely to turn over voluntarily and involuntarily than not to turn over. Further, one of the job performance measures shows a significant curvilinear effect. We conclude that the negative consequences often assumed to be "caused" by counselor turnover may be overstated because those who leave both voluntarily and involuntarily demonstrate generally lower performance than those who remain employed at their treatment program.

  20. Too much of a good thing: curvilinear relationships between personality traits and job performance.

    Science.gov (United States)

    Le, Huy; Oh, In-Sue; Robbins, Steven B; Ilies, Remus; Holland, Ed; Westrick, Paul

    2011-01-01

    The relationships between personality traits and performance are often assumed to be linear. This assumption has been challenged conceptually and empirically, but results to date have been inconclusive. In the current study, we took a theory-driven approach in systematically addressing this issue. Results based on two different samples generally supported our expectations of the curvilinear relationships between personality traits, including Conscientiousness and Emotional Stability, and job performance dimensions, including task performance, organizational citizenship behavior, and counterproductive work behaviors. We also hypothesized and found that job complexity moderated the curvilinear personality–performance relationships such that the inflection points after which the relationships disappear were lower for low-complexity jobs than they were for high-complexity jobs. This finding suggests that high levels of the two personality traits examined are more beneficial for performance in high- than low-complexity jobs. We conclude by discussing the implications of these findings for the use of personality in personnel selection.

  1. A general nuclear motion Hamiltonian and non-internal curvilinear coordinates.

    Science.gov (United States)

    Strobusch, D; Scheurer, Ch

    2013-03-07

    An exact Hamiltonian for nuclear motions in general curvilinear coordinates is derived. It is demonstrated how this Hamiltonian transforms into well-established expressions, such as the Wilson Howard Hamiltonian or the Meyer Günthard Hamiltonian, if the general coordinates are restricted to be rectilinear or internal. Furthermore, a compact expression for the Hamiltonian expressed in non-internal curvilinear coordinates is provided, which makes this coordinate class available for applications in a simple way, since only the Jacobian matrix with respect to the rotating frame coordinates must be calculated. An example, employing a water model potential, exemplifies how different coordinate systems from all three coordinate classes (rectilinear, internal, and non-internal) lead to vibrational spectra, which are in excellent agreement. Thereby, the applicability of the general Hamiltonian is demonstrated and also its correctness is confirmed.

  2. Curvilinear electronics formed using silicon membrane circuits and elastomeric transfer elements.

    Science.gov (United States)

    Ko, Heung Cho; Shin, Gunchul; Wang, Shuodao; Stoykovich, Mark P; Lee, Jeong Won; Kim, Dong-Hun; Ha, Jeong Sook; Huang, Yonggang; Hwang, Keh-Chih; Rogers, John A

    2009-12-01

    Materials and methods to achieve electronics intimately integrated on the surfaces of substrates with complex, curvilinear shapes are described. The approach exploits silicon membranes in circuit mesh structures that can be deformed in controlled ways using thin, elastomeric films. Experimental and theoretical studies of the micromechanics of such curvilinear electronics demonstrate the underlying concepts. Electrical measurements illustrate the high yields that can be obtained. The results represent significant experimental and theoretical advances over recently reported concepts for creating hemispherical photodetectors in electronic eye cameras and for using printable silicon nanoribbons/membranes in flexible electronics. The results might provide practical routes to the integration of high performance electronics with biological tissues and other systems of interest for new applications.

  3. Reduced curvilinear velocity of boar sperm on substrates with increased hydrophobicity

    OpenAIRE

    Mears, M.; Kennelly, T.M.; Geoghegan, M.; Howse, J.R.; Tarmey, D.S.; Pacey, A.A.

    2014-01-01

    The curvilinear velocity (VCL) of boar spermatozoa between standard microscopy glassware decreases when the slides are coated with the hydrophobic polymer polystyrene (PS) compared with the less hydrophobic poly(methyl methacrylate) (PMMA) coating. Sperm from three boars were observed and analyzed using particle tracking software. The VCL did not differ significantly between coatings of different thickness, indicating no penetration of the sperm into the coating and that only the surface laye...

  4. Solving Electromagnetic Scattering and Radiation by FMM with Curvilinear RWG Basis

    Institute of Scientific and Technical Information of China (English)

    HUJun; NIEZaiping; GONGXiaodong

    2003-01-01

    In this paper, fast multipole method (FMM) with curvilinear RWG basis is used to realize fast,accurate solution of electromagnetic scattering and radia-tion from 3-D conducting object. This method needs much less unknowns than traditional RWG basis and conformal rooftop basis, so is especially appropriate for efficient so-lution of scattering and radiation from target with large electrical sizes. Some typical numerical results are shown to demonstrate the validity and efficiency of the presentmethod.

  5. Nonlinear dimension reduction and clustering by Minimum Curvilinearity unfold neuropathic pain and tissue embryological classes

    KAUST Repository

    Cannistraci, Carlo

    2010-09-01

    Motivation: Nonlinear small datasets, which are characterized by low numbers of samples and very high numbers of measures, occur frequently in computational biology, and pose problems in their investigation. Unsupervised hybrid-two-phase (H2P) procedures-specifically dimension reduction (DR), coupled with clustering-provide valuable assistance, not only for unsupervised data classification, but also for visualization of the patterns hidden in high-dimensional feature space. Methods: \\'Minimum Curvilinearity\\' (MC) is a principle that-for small datasets-suggests the approximation of curvilinear sample distances in the feature space by pair-wise distances over their minimum spanning tree (MST), and thus avoids the introduction of any tuning parameter. MC is used to design two novel forms of nonlinear machine learning (NML): Minimum Curvilinear embedding (MCE) for DR, and Minimum Curvilinear affinity propagation (MCAP) for clustering. Results: Compared with several other unsupervised and supervised algorithms, MCE and MCAP, whether individually or combined in H2P, overcome the limits of classical approaches. High performance was attained in the visualization and classification of: (i) pain patients (proteomic measurements) in peripheral neuropathy; (ii) human organ tissues (genomic transcription factor measurements) on the basis of their embryological origin. Conclusion: MC provides a valuable framework to estimate nonlinear distances in small datasets. Its extension to large datasets is prefigured for novel NMLs. Classification of neuropathic pain by proteomic profiles offers new insights for future molecular and systems biology characterization of pain. Improvements in tissue embryological classification refine results obtained in an earlier study, and suggest a possible reinterpretation of skin attribution as mesodermal. © The Author(s) 2010. Published by Oxford University Press.

  6. Uncovering curvilinear relationships between conscientiousness and job performance: how theoretically appropriate measurement makes an empirical difference.

    Science.gov (United States)

    Carter, Nathan T; Dalal, Dev K; Boyce, Anthony S; O'Connell, Matthew S; Kung, Mei-Chuan; Delgado, Kristin M

    2014-07-01

    The personality trait of conscientiousness has seen considerable attention from applied psychologists due to its efficacy for predicting job performance across performance dimensions and occupations. However, recent theoretical and empirical developments have questioned the assumption that more conscientiousness always results in better job performance, suggesting a curvilinear link between the 2. Despite these developments, the results of studies directly testing the idea have been mixed. Here, we propose this link has been obscured by another pervasive assumption known as the dominance model of measurement: that higher scores on traditional personality measures always indicate higher levels of conscientiousness. Recent research suggests dominance models show inferior fit to personality test scores as compared to ideal point models that allow for curvilinear relationships between traits and scores. Using data from 2 different samples of job incumbents, we show the rank-order changes that result from using an ideal point model expose a curvilinear link between conscientiousness and job performance 100% of the time, whereas results using dominance models show mixed results, similar to the current state of the literature. Finally, with an independent cross-validation sample, we show that selection based on predicted performance using ideal point scores results in more favorable objective hiring outcomes. Implications for practice and future research are discussed.

  7. Mechanical Parameters of the Squeeze Film Curvilinear Bearing Lubricated with a Prandtl Fluid

    Science.gov (United States)

    Walicka, A.; Walicki, E.

    2016-12-01

    Based upon a Prandtl fluid flow model, a curvilinear squeeze film bearing is considered. The equations of motion are given in a specific coordinate system. After general considerations on the Prandtl fluid flow these equations are used to derive the Reynolds equation. The solution of this equation is obtained by a method of successive approximation. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of the Prandtl fluid flow in gaps of two simple bearings are presented.

  8. CURVILINEAR PATHS AND TRUST REGION METHODS WITH NONMONOTONIC BACK TRACKING TECHNIQUE FOR UNCONSTRAINED OPTIMIZATION

    Institute of Scientific and Technical Information of China (English)

    De-tong Zhu

    2001-01-01

    In this paper we modify type approximate trust region methods via two curvilinear paths for unconstrained optimization. A mixed strategy using both trust region and line search techniques is adopted which switches to back tracking steps when a trial step produced by the trust region subproblem is unacceptable. We give a series of properties of both optimal path and modified gradient path. The global convergence and fast local convergence rate of the proposed algorithms are established under some reasonable conditions. A nonmonotonic criterion is used to speed up the convergence progress in some ill-conditioned cases.

  9. Geometry Optimization of Crystals by the Quasi-Independent Curvilinear Coordinate Approximation

    CERN Document Server

    Németh, K

    2005-01-01

    The quasi-independent curvilinear coordinate approximation (QUICCA) method [K. N\\'emeth and M. Challacombe, J. Chem. Phys. {\\bf 121}, 2877, (2004)] is extended to the optimization of crystal structures. We demonstrate that QUICCA is valid under periodic boundary conditions, enabling simultaneous relaxation of the lattice and atomic coordinates, as illustrated by tight optimization of polyethylene, hexagonal boron-nitride, a (10,0) carbon-nanotube, hexagonal ice, quartz and sulfur at the $\\Gamma$-point RPBE/STO-3G level of theory.

  10. Differential algebraic method for arbitrary order curvilinear-axis combined geometric-chromatic aberration analysis

    CERN Document Server

    Cheng Min; Lu Yi Long; Yao Zhen Hua

    2003-01-01

    The principle of differential algebra is applied to analyse and calculate arbitrary order curvilinear-axis combined geometric-chromatic aberrations of electron optical systems. Expressions of differential algebraic form of high order combined aberrations are obtained and arbitrary order combined aberrations can be calculated numerically. As an example, a typical wide electron beam focusing system with curved optical axes named magnetic immersion lens has been studied. All the second-order and third-order combined geometric-chromatic aberrations of the lens have been calculated, and the patterns of the corresponding geometric aberrations and combined aberrations have been given as well.

  11. A computer program for generating two-dimensional boundary-fitted orthogonal curvilinear coordinate systems

    Energy Technology Data Exchange (ETDEWEB)

    Barbaro, M. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dipt. Innovazione

    1997-11-01

    A numerical method is described which generates an orthogonal curvilinear mesh, subject to the constraint that mesh lines are matched to all boundaries of a closed, simply connected two-dimensional region of arbitrary shape. The method is based on the solution, by an iterative finite-difference technique, of an elliptic differential system of equations for the Cartesian coordinates of the orthogonal grid nodes. The interior grid distribution is controlled by a technique which ensures that coordinate lines can be concentrated as desired. Examples of orthogonal meshes inscribed in various geometrical figures are included.

  12. Natural curvilinear coordinates for ideal magnetohydrodynamics equations. Solutions with constant total pressure

    CERN Document Server

    Golovin, Sergey V

    2010-01-01

    Equations of magneto-gasdynamics in the natural curvilinear system of coordinates where trajectories and magnetic lines play a role of coordinate curves are reduced to the nonlinear vector wave equation coupled with the incompressibility condition in the form of the generalized Cauchy integral. The symmetry group of obtained equation, equivalence transformation, and group classification with respect to the constitutive equation are calculated. New exact solutions with functional arbitrariness describing non-stationary incompressible flows with constant total pressure are given by explicit formulae. The corresponding magnetic surfaces have the shape of deformed nested cylinders, tori, or knotted tubes.

  13. Natural curvilinear coordinates for ideal MHD equations. Non-stationary flows with constant total pressure

    Energy Technology Data Exchange (ETDEWEB)

    Golovin, Sergey V., E-mail: sergey@hydro.nsc.r [Lavrentyev Institute of Hydrodynamics SB RAS, 630090 Novosibirsk (Russian Federation); Department of Mechanics and Mathematics, Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2011-01-17

    Equations of magnetohydrodynamics (MHD) in the natural curvilinear system of coordinates where trajectories and magnetic lines play a role of coordinate curves are reduced to the non-linear vector wave equation coupled with the incompressibility condition in the form of the generalized Cauchy integral. The symmetry group of obtained equation, equivalence transformation, and group classification with respect to the constitutive equation are calculated. New exact solutions with functional arbitrariness describing non-stationary incompressible flows with constant total pressure are given by explicit formulae. The corresponding magnetic surfaces have the shape of deformed nested cylinders, tori, or knotted tubes.

  14. Design of optical cloaks and illusion devices along a circumferential direction in curvilinear coordinates

    Science.gov (United States)

    Chen, Tungyang; Yu, Shang-Ru

    2010-11-01

    We propose a cloaking and illusion device of circumferential topology based on the concept of transformation optics. The device is capable to cloak an object and/or simultaneously generate illusion images along a circumferential direction in curvilinear orthogonal coordinates. This feature allows us to construct multiple illusions in different ways, irrespective of the profile and direction of incident wave. Particularly when the device is served as a building brick of a larger device, one can generate a circumferential array of illusions in a periodic or any preferred pattern. We demonstrate the effectiveness of the proposed illusion devices by carrying out full wave simulations based on finite element calculations.

  15. Curvilinear effects of invasive plants on plant diversity: plant community invaded by Sphagneticola trilobata.

    Directory of Open Access Journals (Sweden)

    Shan-Shan Qi

    Full Text Available The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%, compared with the native plants (over 60%. Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants.

  16. Anharmonic Vibrational Treatment Exclusively in Curvilinear Valence Coordinates: The Case of Formamide.

    Science.gov (United States)

    Richter, F; Thaunay, F; Lauvergnat, D; Carbonnière, P

    2015-12-01

    A highly correlated approach using curvilinear valence coordinates is applied to calculate the vibrational fundamentals and some combination modes of the formamide molecule with high accuracy. A series of potential energy surfaces (PESs) has been generated by AGAPES, a program for adaptive generation of adiabatic PESs, at various electronic structure qualities until excellent nonaccidental agreement with the experimentally assigned fundamental transitions was reached at the CCSDT(T)-F12a/aug-cc-pVTZ level of theory using the improved relaxation method of the Heidelberg multiconfiguration time-dependent Hartree (MCTDH) package in connection with an exact expression for the kinetic energy in valence coordinates generated by the TANA program. By comparison of the overtone series ν1-3ν1 to experiment, we demonstrate that the known problems concerning the floppy ν1 wagging motion are solved within this approach. The potential energy coupling as well as the vibrational coupling in curvilinear coordinates is discussed together with the efficiency of this approach.

  17. Maternal Encouragement to Approach Novelty: A Curvilinear Relation to Change in Anxiety for Inhibited Toddlers.

    Science.gov (United States)

    Kiel, Elizabeth J; Premo, Julie E; Buss, Kristin A

    2016-04-01

    Various parenting behaviors (e.g., protection, intrusiveness, sensitivity) have been shown to impact young children's anxiety development, particularly for temperamentally inhibited children. These behaviors have sometimes predicted both increases and decreases in anxiety in inhibited children, suggesting that linear relations may not adequately model their influence. In the current study, we proposed the dimension of encouragement to approach novelty to characterize parenting behavior ranging from very little encouragement (i.e., protective behavior) to very strong encouragement (i.e., intrusiveness), with gentle encouragement residing in the middle. In a sample of 110 toddlers (48 female, 62 male) and their mothers, the linear and curvilinear effects of this parenting dimension were investigated in relation to change in child separation anxiety and shyness from age 2 to age 3. Inhibited temperament was also investigated as a moderator. Encouragement to approach novelty displayed the hypothesized curvilinear relation to change in separation anxiety, but not shyness, at extreme levels of inhibited temperament. Toddlers increased in separation anxiety when mothers' encouragement resided at either extreme end of the continuum, with lower child anxiety occurring when mothers displayed behavior closer to the middle of the continuum. Implications for the study of parenting outcomes for inhibited toddlers are discussed.

  18. Marker Pen Lithography for Flexible and Curvilinear On-Chip Energy Storage

    KAUST Repository

    Jiang, Qiu

    2015-07-14

    On-chip energy storage using microsupercapacitors can serve the dual role of supplementing batteries for pulse power delivery, and replacement of bulky electrolytic capacitors in ac-line filtering applications. Despite complexity and processing costs, microfabrication techniques are being employed in fabricating a great variety of microsupercapacitor devices. Here, a simple, cost-effective, and versatile strategy is proposed to fabricate flexible and curvilinear microsupercapacitors (MSCs). The protocol involves writing sacrificial ink patterns using commercial marker pens on rigid, flexible, and curvilinear substrates. It is shown that this process can be used in both lift-off and etching modes, and the possibility of multistack design of active materials using simple pen lithography is demonstrated. As a prototype, this method is used to produce conducting polymer MSCs involving both poly(3,4-ethylenedioxythiophene), polyaniline, and metal oxide (MnO2) electrode materials. Typical values of energy density in the range of 5-11 mWh cm-3 at power densities of 1-6 W cm-3 are achieved, which is comparable to thin film batteries and superior to the carbon and metal oxide based microsupercapacitors reported in the literature. The simplicity and broad scope of this innovative strategy can open up new avenues for easy and scalable fabrication of a wide variety of on-chip energy storage devices. © 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.

  19. Modelling free surface flow with curvilinear streamlines by a non-hydrostatic model

    Directory of Open Access Journals (Sweden)

    Zerihun Yebegaeshet T.

    2016-09-01

    Full Text Available This study addresses a particular phenomenon in open channel flows for which the basic assumption of hydrostatic pressure distribution is essentially invalid, and expands previous suggestions to flows where streamline curvature is significant. The proposed model incorporates the effects of the vertical curvature of the streamline and steep slope, in making the pressure distribution non-hydrostatic, and overcomes the accuracy problem of the Saint-Venant equations when simulating curvilinear free surface flow problems. Furthermore, the model is demonstrated to be a higher-order one-dimensional model that includes terms accounting for wave-like variations of the free surface on a constant slope channel. Test results of predicted flow surface and pressure profiles for flow in a channel transition from mild to steep slopes, transcritical flow over a short-crested weir and flow with dual free surfaces are compared with experimental data and previous numerical results. A good agreement is attained between the experimental and computed results. The overall simulation results reveal the satisfactory performance of the proposed model in simulating rapidly varied gravity-driven flows with predominant non-hydrostatic pressure distribution effects. This study suggests that a higher-order pressure equation should be used for modelling the pressure distribution of a curvilinear flow in a steeply sloping channel.

  20. Numerical Simulation of Wave-Induced Currents Combined with Parabolic Mild-Slope Equation in Curvilinear Coordinates

    Institute of Scientific and Technical Information of China (English)

    CUI Lei; TONG Fei-fei; SHI Feng

    2011-01-01

    Researches on breaking-induced currents by waves are summarized firstly in this paper.Then,a combined numerical model in orthogonal curvilinear coordinates is presented to simulate wave-induced current in areas with curved boundary or irregular coastline.The proposed wave-induced current model includes a nearshore current module established through orthogonal curvilinear transformation form of shallow water equations and a wave module based on the curvilinear parabolic approximation wave equation.The wave module actually serves as the driving force to provide the current module with required radiation stresses.The Crank-Nicolson finite difference scheme and the alternating directions implicit method are used to solve the wave and current module,respectively.The established surf zone currents model is validated by two numerical experiments about longshore currents and rip currents in basins with rip channel and breakwater.The numerical results are compared with the measured data and published numerical results.

  1. Different thresholds for detecting osteophytes and joint space narrowing exist between the site investigators and the centralized reader in a multicenter knee osteoarthritis study - data from the Osteoarthritis Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Guermazi, Ali; Hayashi, Daichi [Boston University School of Medicine, Quantitative Imaging Center, Department of Radiology, Boston, MA (United States); Hunter, David J. [New England Baptist Hospital, Division of Research, Boston, MA (United States); University of Sydney, Northern Clinical School, Sydney (Australia); Li, Ling [New England Baptist Hospital, Division of Research, Boston, MA (United States); Benichou, Olivier [Eli Lilly and Co, Indianapolis, IN (United States); Eckstein, Felix [Paracelsus Medical University, Salzburg (Austria); Chondrometrics GmbH, Ainring (Germany); Kwoh, C.K. [University of Pittsburgh School of Medicine, Division of Rheumatology and Clinical Immunology, Pittsburgh, PA (United States); Nevitt, Michael [University of California, Department of Epidemiology and Biostatistics, San Francisco, CA (United States)

    2012-02-15

    To evaluate how the reading of knee radiographs by site investigators differs from that by an expert musculoskeletal radiologist who trained and validated them in a multicenter knee osteoarthritis (OA) study. A subset of participants from the Osteoarthritis Initiative progression cohort was studied. Osteophytes and joint space narrowing (JSN) were evaluated using Kellgren-Lawrence (KL) and Osteoarthritis Research Society International (OARSI) grading. Radiographs were read by site investigators, who received training and validation of their competence by an expert musculoskeletal radiologist. Radiographs were re-read by this radiologist, who acted as a central reader. For KL and OARSI grading of osteophytes, discrepancies between two readings were adjudicated by another expert reader. Radiographs from 96 subjects (49 women) and 192 knees (138 KL grade {>=} 2) were included. The site reading showed moderate agreement for KL grading overall (kappa=0.52) and for KL {>=} 2 (i.e., radiographic diagnosis of ''definite OA''; kappa=0.41). For OARSI grading, the site reading showed substantial agreement for lateral and medial JSN (kappa=0.65 and 0.71), but only fair agreement for osteophytes (kappa=0.37). For KL grading, the adjudicator's reading showed substantial agreement with the centralized reading (kappa=0.62), but only slight agreement with the site reading (kappa = 0.10). Site investigators over-graded osteophytes compared to the central reader and the adjudicator. Different thresholds for scoring of JSN exist even between experts. Our results suggest that research studies using radiographic grading of OA should use a centralized reader for all grading. (orig.)

  2. Optimization of Curvi-Linear Tracing Applied to Solar Physics and Biophysics

    CERN Document Server

    Aschwanden, Markus J; Katrukha, Eugene A

    2013-01-01

    We developed an automated pattern recognition code that is particularly well suited to extract one-dimensional curvi-linear features from two-dimensional digital images. A former version of this {\\sl Oriented Coronal CUrved Loop Tracing (OCCULT)} code was applied to spacecraft images of magnetic loops in the solar corona, recorded with the NASA spacecraft {\\sl Transition Region And Coronal Explorer (TRACE)} in extreme ultra-violet wavelengths. Here we apply an advanced version of this code ({\\sl OCCULT-2}) also to similar images from the {\\sl Solar Dynamics Observatory (SDO)}, to chromospheric H-$\\alpha$ images obtained with the {\\sl Swedish Solar Telescope (SST)}, and to microscopy images of microtubule filaments in live cells in biophysics. We provide a full analytical description of the code, optimize the control parameters, and compare the automated tracing with visual/manual methods. The traced structures differ by up to 16 orders of magnitude in size, which demonstrates the universality of the tracing a...

  3. Characterizing Curvilinear Features Using the Localized Normal-Score Ensemble Kalman Filter

    Directory of Open Access Journals (Sweden)

    Haiyan Zhou

    2012-01-01

    Full Text Available The localized normal-score ensemble Kalman filter is shown to work for the characterization of non-multi-Gaussian distributed hydraulic conductivities by assimilating state observation data. The influence of type of flow regime, number of observation piezometers, and the prior model structure are evaluated in a synthetic aquifer. Steady-state observation data are not sufficient to identify the conductivity channels. Transient-state data are necessary for a good characterization of the hydraulic conductivity curvilinear patterns. Such characterization is very good with a dense network of observation data, and it deteriorates as the number of observation piezometers decreases. It is also remarkable that, even when the prior model structure is wrong, the localized normal-score ensemble Kalman filter can produce acceptable results for a sufficiently dense observation network.

  4. The role of team goal monitoring in the curvilinear relationship between team efficacy and team performance.

    Science.gov (United States)

    Rapp, Tammy L; Bachrach, Daniel G; Rapp, Adam A; Mullins, Ryan

    2014-09-01

    In this research, we apply a team self-regulatory perspective to build and test theory focusing on the relationships between team efficacy and 2 key team performance criteria: a performance behavior (i.e., team effort) and a performance outcome (i.e., objective team sales). We theorize that rather than having a linear association, the performance benefits of team efficacy reach a point of inflection, reflective of too much of a good thing. Further, in an effort to establish a boundary condition of the inverted-U shaped relationship we predict, we also test the moderating role played by team goal monitoring in the nonmonotonic relationship between team efficacy and team performance. The results from a lagged field test, in which we collect multisource data from 153 technology sales teams, reveal a significant curvilinear association that is moderated by team goal monitoring behavior. Implications for theory and practice are discussed.

  5. Reduced curvilinear velocity of boar sperm on substrates with increased hydrophobicity.

    Science.gov (United States)

    Mears, Matthew; Kennelly, Thomas M; Howse, Jonathan R; Tarmey, Drew S; Geoghegan, Mark; Pacey, Allan A

    2014-03-15

    The curvilinear velocity (VCL) of boar spermatozoa between standard microscopy glassware decreases when the slides are coated with the hydrophobic polymer polystyrene (PS) compared with the less hydrophobic poly(methyl methacrylate) (PMMA) coating. Sperm from three boars were observed and analyzed using particle tracking software. The VCL did not differ significantly between coatings of different thickness, indicating no penetration of the sperm into the coating and that only the surface layer of the polymer film interacts with the sperm and buffer medium. The VCL of sperm between PS-coated surfaces was significantly reduced compared with PMMA surfaces (P IVF. Controlling the velocity of sperm using the interaction properties of inert polymer coatings could lead to new sperm selection procedures for clinical use or the development of model systems to better understand sperm-surface interactions.

  6. Global structure search for molecules on surfaces: Efficient sampling with curvilinear coordinates

    Science.gov (United States)

    Krautgasser, Konstantin; Panosetti, Chiara; Palagin, Dennis; Reuter, Karsten; Maurer, Reinhard J.

    2016-08-01

    Efficient structure search is a major challenge in computational materials science. We present a modification of the basin hopping global geometry optimization approach that uses a curvilinear coordinate system to describe global trial moves. This approach has recently been shown to be efficient in structure determination of clusters [C. Panosetti et al., Nano Lett. 15, 8044-8048 (2015)] and is here extended for its application to covalent, complex molecules and large adsorbates on surfaces. The employed automatically constructed delocalized internal coordinates are similar to molecular vibrations, which enhances the generation of chemically meaningful trial structures. By introducing flexible constraints and local translation and rotation of independent geometrical subunits, we enable the use of this method for molecules adsorbed on surfaces and interfaces. For two test systems, trans-β-ionylideneacetic acid adsorbed on a Au(111) surface and methane adsorbed on a Ag(111) surface, we obtain superior performance of the method compared to standard optimization moves based on Cartesian coordinates.

  7. Global structure search for molecules on surfaces: Efficient sampling with curvilinear coordinates.

    Science.gov (United States)

    Krautgasser, Konstantin; Panosetti, Chiara; Palagin, Dennis; Reuter, Karsten; Maurer, Reinhard J

    2016-08-28

    Efficient structure search is a major challenge in computational materials science. We present a modification of the basin hopping global geometry optimization approach that uses a curvilinear coordinate system to describe global trial moves. This approach has recently been shown to be efficient in structure determination of clusters [C. Panosetti et al., Nano Lett. 15, 8044-8048 (2015)] and is here extended for its application to covalent, complex molecules and large adsorbates on surfaces. The employed automatically constructed delocalized internal coordinates are similar to molecular vibrations, which enhances the generation of chemically meaningful trial structures. By introducing flexible constraints and local translation and rotation of independent geometrical subunits, we enable the use of this method for molecules adsorbed on surfaces and interfaces. For two test systems, trans-β-ionylideneacetic acid adsorbed on a Au(111) surface and methane adsorbed on a Ag(111) surface, we obtain superior performance of the method compared to standard optimization moves based on Cartesian coordinates.

  8. Finite-difference simulation and visualization of elastodynamics in time-evolving generalized curvilinear coordinates

    Science.gov (United States)

    Kaul, Upender K. (Inventor)

    2009-01-01

    Modeling and simulation of free and forced structural vibrations is essential to an overall structural health monitoring capability. In the various embodiments, a first principles finite-difference approach is adopted in modeling a structural subsystem such as a mechanical gear by solving elastodynamic equations in generalized curvilinear coordinates. Such a capability to generate a dynamic structural response is widely applicable in a variety of structural health monitoring systems. This capability (1) will lead to an understanding of the dynamic behavior of a structural system and hence its improved design, (2) will generate a sufficiently large space of normal and damage solutions that can be used by machine learning algorithms to detect anomalous system behavior and achieve a system design optimization and (3) will lead to an optimal sensor placement strategy, based on the identification of local stress maxima all over the domain.

  9. The Influence of Creative Process Engagement on Employee Creative Performance and Overall Job Performance: A Curvilinear Assessment

    Science.gov (United States)

    Zhang, Xiaomeng; Bartol, Kathryn M.

    2010-01-01

    Integrating theories addressing attention and activation with creativity literature, we found an inverted U-shaped relationship between creative process engagement and overall job performance among professionals in complex jobs in an information technology firm. Work experience moderated the curvilinear relationship, with low-experience employees…

  10. Cognitive Differences for Ages 16 to 89 Years (Canadian WAIS-III): Curvilinear with Flynn and Processing Speed Corrections

    Science.gov (United States)

    Lee, Hoyee Flora; Gorsuch, Richard L.; Saklofske, Donald H.; Patterson, Colleen A.

    2008-01-01

    Adult cognitive age differences in the Wechsler Adult Intelligence Scale-III Canadian normative data were curvilinear for most scales and for the Verbal Comprehension (VC), Perceptual Organization (PO), and Working Memory (WM) factors. These showed stable or increasing scores in early adulthood followed by decreasing scores, necessitating a…

  11. Assessment of the calcification of the nuchal ligament and osteophytes of the cervical spine in obstructive sleep apnoea subjects and snorers.

    Science.gov (United States)

    Ando, E; Shigeta, Y; Nejima, J; Yamanaka, H; Hirai, S; Ogawa, T; Clark, G T; Enciso, R

    2016-02-01

    The previous reports suggest that obstructive sleep apnoea (OSA) is related to metabolic syndrome, mineral metabolism disorders and cardiovascular disease. In addition, a possible relationship between obesity and the calcification of ligaments has been implied. However, the potential link between OSA and the calcification of ligaments has not been directly studied. In this present study, to investigate the potential link between OSA and the calcification of ligaments, we examined the prevalence of the calcification of ligaments in OSA patients and the relationship between these findings and OSA severity. Eighty consecutive patients (60 males, 20 females) diagnosed as OSA or a heavy snorer based on full-night polyso-mnography were retrospectively recruited from May 2006 to July 2008. Each patient underwent cephalometric imaging examination before the arrangement of an oral appliance. One calibrated observer (YS) reviewed the cephalometric images for the presence of calcification of the nuchal ligament and osteophytes of the cervical spine. The prevalence of calcification of the nuchal ligament in OSA patients and snorers was 46.3% (males: 52%, females: 30%) There was a significant positive correlation between the severity of OSA (AHI) and the calcification of the nuchal ligament before and after adjusting for BMI. The prevalence of the calcification of the nuchal ligament in OSA subjects and snorers was higher than in previous studies with non-OSA subjects. In addition, it is suggested that the severity of OSA correlates with the presence of calcification of the nuchal ligament.

  12. Minimum curvilinearity to enhance topological prediction of protein interactions by network embedding

    KAUST Repository

    Cannistraci, Carlo

    2013-06-21

    Motivation: Most functions within the cell emerge thanks to protein-protein interactions (PPIs), yet experimental determination of PPIs is both expensive and time-consuming. PPI networks present significant levels of noise and incompleteness. Predicting interactions using only PPI-network topology (topological prediction) is difficult but essential when prior biological knowledge is absent or unreliable.Methods: Network embedding emphasizes the relations between network proteins embedded in a low-dimensional space, in which protein pairs that are closer to each other represent good candidate interactions. To achieve network denoising, which boosts prediction performance, we first applied minimum curvilinear embedding (MCE), and then adopted shortest path (SP) in the reduced space to assign likelihood scores to candidate interactions. Furthermore, we introduce (i) a new valid variation of MCE, named non-centred MCE (ncMCE); (ii) two automatic strategies for selecting the appropriate embedding dimension; and (iii) two new randomized procedures for evaluating predictions.Results: We compared our method against several unsupervised and supervisedly tuned embedding approaches and node neighbourhood techniques. Despite its computational simplicity, ncMCE-SP was the overall leader, outperforming the current methods in topological link prediction.Conclusion: Minimum curvilinearity is a valuable non-linear framework that we successfully applied to the embedding of protein networks for the unsupervised prediction of novel PPIs. The rationale for our approach is that biological and evolutionary information is imprinted in the non-linear patterns hidden behind the protein network topology, and can be exploited for predicting new protein links. The predicted PPIs represent good candidates for testing in high-throughput experiments or for exploitation in systems biology tools such as those used for network-based inference and prediction of disease-related functional modules. The

  13. Loss of lag-response curvilinearity of indices of heart rate variability in congestive heart failure

    Directory of Open Access Journals (Sweden)

    Smith Michael L

    2006-06-01

    Full Text Available Abstract Background Heart rate variability (HRV is known to be impaired in patients with congestive heart failure (CHF. Time-domain analysis of ECG signals traditionally relies heavily on linear indices of an essentially non-linear phenomenon. Poincaré plots are commonly used to study non-linear behavior of physiologic signals. Lagged Poincaré plots incorporate autocovariance information and analysis of Poincaré plots for various lags can provide interesting insights into the autonomic control of the heart. Methods Using Poincaré plot analysis, we assessed whether the relation of the lag between heart beats and HRV is altered in CHF. We studied the influence of lag on estimates of Poincaré plot indices for various lengths of beat sequence in a public domain data set (PhysioNet of 29 subjects with CHF and 54 subjects with normal sinus rhythm. Results A curvilinear association was observed between lag and Poincaré plot indices (SD1, SD2, SDLD and SD1/SD2 ratio in normal subjects even for a small sequence of 50 beats (p value for quadratic term 3 × 10-5, 0.002, 3.5 × 10-5 and 0.0003, respectively. This curvilinearity was lost in patients with CHF even after exploring sequences up to 50,000 beats (p values for quadratic term > 0.5. Conclusion Since lagged Poincaré plots incorporate autocovariance information, these analyses provide insights into the autonomic control of heart rate that is influenced by the non-linearity of the signal. The differences in lag-response in CHF patients and normal subjects exist even in the face of the treatment received by the CHF patients.

  14. NUMERICAL SOLUTION OF THE UNSTEADY INCOMPRESSIBLE NAVIER-STOKES EQUATIONS ON THE CURVILINEAR HALF-STAGGERED MESH

    Institute of Scientific and Technical Information of China (English)

    Lan-chieh Huang

    2000-01-01

    In this paper, the Crank-Nicholson + component-consistent pressure correction method for the numerical solution of the unsteady incompressible Navier-Stokes equation of [1] on the rectangular half-staggered mesh has been extended to the curvilinear half-staggered mesh. The discrete projection, both for the projection step in the solution procedure and for the related differential-algebraic equations, has been carefully studied and verified. It is proved that the proposed method is also unconditionally (in△t) nonlinearly stable on the curvilinear mesh, provided the mesh is not too skewed. It is seen that for problems with an outflow bound- ary, the half-staggered mesh is especially advantageous. Results of preliminary numerical experiments support these claims.

  15. Orthogonal invariant sets of the diffusion tensor and the development of a curvilinear set suitable for low-anisotropy tissues

    CERN Document Server

    Damion, Robin A; Ingham, Eileen; Jin, Zhongmin; Ries, Michael E

    2014-01-01

    We develop a curvilinear invariant set of the diffusion tensor which may be applied to Diffusion Tensor Imaging measurements on tissues and porous media. This new set is an alternative to the more common invariants such as fractional anisotropy and the diffusion mode. The alternative invariant set possesses a different structure to the other known invariant sets; the second and third members of the curvilinear set measure the degree of orthotropy and oblateness/prolateness, respectively. The proposed advantage of these invariants is that they may work well in situations of low diffusion anisotropy and isotropy, as is often observed in tissues such as cartilage. We also explore the other orthogonal invariant sets in terms of their geometry in relation to eigenvalue space; a cylindrical set, a spherical set (including fractional anisotropy and the mode), and a log-Euclidean set. These three sets have a common structure. The first invariant measures the magnitude of the diffusion, the second and third invariants...

  16. An overset curvilinear/immersed boundary framework for high resolution simulations of wind and hydrokinetic turbine flows

    Science.gov (United States)

    Borazjani, Iman; Behara, Suresh; Natarajan, Ganesh; Sotiropoulos, Fotis

    2009-11-01

    We generalize the curvilinear/immersed boundary method to incorporate overset grids to enable the simulation of more complicated geometries and increase grid resolution locally near complex immersed boundary. The new method has been applied to carry out high resolution simulations of wind and hydrokinetic turbine rotors. An interior fine mesh contains the rotor blades and is embedded within a coarser background mesh. The rotor blades can be treated either as immersed boundaries or using curvilinear, boundary-conforming overset grids. The numerical methodology has been generalized to include both inertial and non-inertial frame formulations. The method is validated by applying it to simulate the flow for the NREL wind turbine rotor for various turbine operating points. Inviscid, unsteady RANS and LES simulations are carried out and compared with experimental data. Preliminary results will also be presented for the hydrokinetic turbine rotor installed at the Roosevelt Island Tidal Energy project in New York City.

  17. Stability Estimates for ℎ- Spectral Element Methods for General Elliptic Problems on Curvilinear Domains

    Indian Academy of Sciences (India)

    Pravir Dutt; Satyendra Tomar

    2003-11-01

    In this paper we show that the ℎ- spectral element method developed in [3,8,9] applies to elliptic problems in curvilinear polygons with mixed Neumann and Dirichlet boundary conditions provided that the Babuska–Brezzi inf-sup conditions are satisfied. We establish basic stability estimates for a non-conforming ℎ- spectral element method which allows for simultaneous mesh refinement and variable polynomial degree. The spectral element functions are non-conforming if the boundary conditions are Dirichlet. For problems with mixed boundary conditions they are continuous only at the vertices of the elements. We obtain a stability estimate when the spectral element functions vanish at the vertices of the elements, which is needed for parallelizing the numerical scheme. Finally, we indicate how the mesh refinement strategy and choice of polynomial degree depends on the regularity of the coefficients of the differential operator, smoothness of the sides of the polygon and the regularity of the data to obtain the maximum accuracy achievable.

  18. Micro-Grooving and Micro-Threading Tools for Fabricating Curvilinear Features

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS,DAVID P.; VASILE,MICHAEL J.; KRISHNAN,A.S.M.

    2000-07-24

    This paper presents techniques for fabricating microscopic, curvilinear features in a variety of workpiece materials. Micro-grooving and micro-threading tools having cutting widths as small as 13 {micro}m are made by focused ion beam sputtering and used for ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide to create a number of critically aligned facets. Sputtering produces rake facets of desired angle and cutting edges having radii of curvature equal to 0.4 {micro}m. Clearance for minimizing frictional drag of a tool results from a particular ion beam/target geometry that accounts for the sputter yield dependence on incidence angle. It is believed that geometrically specific cutting tools of this dimension have not been made previously. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close match between tool width and feature size. Microtools are used to machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061 Al cylindrical workplaces. Micro-grooving tools are also used to fabricate sinusoidal cross-section features in planar metal samples.

  19. Bound-Preserving Discontinuous Galerkin Methods for Conservative Phase Space Advection in Curvilinear Coordinates

    CERN Document Server

    Endeve, Eirik; Xing, Yulong; Mezzacappa, Anthony

    2014-01-01

    We extend the positivity-preserving method of Zhang & Shu (2010, JCP, 229, 3091-3120) to simulate the advection of neutral particles in phase space using curvilinear coordinates. The ability to utilize these coordinates is important for non-equilibrium transport problems in general relativity and also in science and engineering applications with specific geometries. The method achieves high-order accuracy using Discontinuous Galerkin (DG) discretization of phase space and strong stability-preserving, Runge-Kutta (SSP-RK) time integration. Special care in taken to ensure that the method preserves strict bounds for the phase space distribution function $f$; i.e., $f\\in[0,1]$. The combination of suitable CFL conditions and the use of the high-order limiter proposed in Zhang & Shu (2010) is sufficient to ensure positivity of the distribution function. However, to ensure that the distribution function satisfies the upper bound, the discretization must, in addition, preserve the divergence-free property of ...

  20. Adaptive-Anisotropic Wavelet Collocation Method on general curvilinear coordinate systems

    Science.gov (United States)

    Brown-Dymkoski, Eric; Vasilyev, Oleg V.

    2017-03-01

    A new general framework for an Adaptive-Anisotropic Wavelet Collocation Method (A-AWCM) for the solution of partial differential equations is developed. This proposed framework addresses two major shortcomings of existing wavelet-based adaptive numerical methodologies, namely the reliance on a rectangular domain and the "curse of anisotropy", i.e. drastic over-resolution of sheet- and filament-like features arising from the inability of the wavelet refinement mechanism to distinguish highly correlated directional information in the solution. The A-AWCM addresses both of these challenges by incorporating coordinate transforms into the Adaptive Wavelet Collocation Method for the solution of PDEs. The resulting integrated framework leverages the advantages of both the curvilinear anisotropic meshes and wavelet-based adaptive refinement in a complimentary fashion, resulting in greatly reduced cost of resolution for anisotropic features. The proposed Adaptive-Anisotropic Wavelet Collocation Method retains the a priori error control of the solution and fully automated mesh refinement, while offering new abilities through the flexible mesh geometry, including body-fitting. The new A-AWCM is demonstrated for a variety of cases, including parabolic diffusion, acoustic scattering, and unsteady external flow.

  1. Short and medium-term evolution of shoreline undulations on curvilinear coasts

    Science.gov (United States)

    López-Ruiz, Alejandro; Ortega-Sánchez, Miguel; Baquerizo, Asunción; Losada, Miguel A.

    2012-07-01

    This article proposes a one-line type model to explain the formation and evolution of shoreline undulations on circular or elliptic curvilinear coasts, such as littoral spits. The model takes into account the variation of the surf zone width stemming from the convergence and divergence of the waves propagating over a conical bathymetry with a small radius of curvature. The alongshore sediment transport varies with the angle formed by the wave crests and the coastline, as well as with surf zone width and sediment grain size. This model was applied to the shoreline undulations observed at the mouth of the River Guadalquivir (Gulf of Cádiz, Spain) and those at El Puntal Spit (Cantabrian Sea, Spain). In the first case, the model was forced with several sets of five-year wave climate simulations. At the El Puntal Spit, three different wave conditions, corresponding to the growth, saturation, and decay stages of the undulations, were simulated. In both cases, a net longitudinal growth of the spits was observed. Despite simplifications, the amplitude and wavelength of the shoreline undulations agree with the observations. Furthermore, both the zone and development time of the shoreline undulations can be estimated. The mechanism proposed for their generation and evolution may be complementary to other mechanisms, such as the instability mechanism of the coastline associated with high-angle waves.

  2. General shot refinement technique on fracturing of curvilinear shape for VSB mask writer

    Science.gov (United States)

    Tao, Takuya; Takahashi, Nobuyasu; Hamaji, Masakazu; Park, Jisoong; Lee, Sukho; Park, Sunghoon

    2014-10-01

    The increasing complexity of RET solutions has increased the shot count for advanced photomasks. In particular, the introduction of the inverse lithography technique (ILT) brings a significant increase in mask complexity and conventional fracturing algorithms generate many more shots because they are not optimized for curvilinear shapes. Several methods have been proposed to reduce shot count for ILT photomasks. One of the stronger approaches is model-based fracturing, which utilizes precise dose control, shot overlaps and many other techniques. However, it requires much more computation resources and upgrades to the EB mask writer to support user-level dose modulation and shot overlaps. We proposed an efficient algorithm to fracture curvy shapes into VSB shots5 which was based on geometry processing. The algorithm achieved better EPE and reasonable process time compared with a conventional fracturing algorithm but its fracturing quality can be degraded for the pattern which has relatively rough contour though it is curvy ILT pattern. In this paper, we present a couple of general techniques to refine a set of VSB shots to reduce edge placement error (EPE) to an original curvy contour with their experimental results.

  3. Finite volume method in 3-D curvilinear coordinates with multiblocking procedure for radiative transport problems

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, P.; Steven, M.; Issendorff, F.V.; Trimis, D. [Institute of Fluid Mechanics (LSTM), University of Erlangen-Nuremberg, Cauerstrasse 4, D 91058 Erlangen (Germany)

    2005-10-01

    The finite volume method of radiation is implemented for complex 3-D problems in order to use it for combined heat transfer problems in connection with CFD codes. The method is applied for a 3-D block structured grid in a radiatively participating medium. The method is implemented in non-orthogonal curvilinear coordinates so that it can handle irregular structure with a body-fitted structured grid. The multiblocking is performed with overlapping blocks to exchange the information between the blocks. Five test problems are considered in this work. In the first problem, present work is validated with the results of the literature. To check the accuracy of multiblocking, a single block is divided into four blocks and results are validated against the results of the single block simulated alone in the second problem. Complicated geometries are considered to show the applicability of the present procedure in the last three problems. Both radiative and non-radiative equilibrium situations are considered along with an absorbing, emitting and scattering medium. (author)

  4. Conservative high-order-accurate finite-difference methods for curvilinear grids

    Science.gov (United States)

    Rai, Man M.; Chakrvarthy, Sukumar

    1993-01-01

    Two fourth-order-accurate finite-difference methods for numerically solving hyperbolic systems of conservation equations on smooth curvilinear grids are presented. The first method uses the differential form of the conservation equations; the second method uses the integral form of the conservation equations. Modifications to these schemes, which are required near boundaries to maintain overall high-order accuracy, are discussed. An analysis that demonstrates the stability of the modified schemes is also provided. Modifications to one of the schemes to make it total variation diminishing (TVD) are also discussed. Results that demonstrate the high-order accuracy of both schemes are included in the paper. In particular, a Ringleb-flow computation demonstrates the high-order accuracy and the stability of the boundary and near-boundary procedures. A second computation of supersonic flow over a cylinder demonstrates the shock-capturing capability of the TVD methodology. An important contribution of this paper is the dear demonstration that higher order accuracy leads to increased computational efficiency.

  5. The influence of time management skill on the curvilinear relationship between organizational citizenship behavior and task performance.

    Science.gov (United States)

    Rapp, Adam A; Bachrach, Daniel G; Rapp, Tammy L

    2013-07-01

    In this research we integrate resource allocation and social exchange perspectives to build and test theory focusing on the moderating role of time management skill in the nonmonotonic relationship between organizational citizenship behavior (OCB) and task performance. Results from matching survey data collected from 212 employees and 41 supervisors and from task performance metrics collected several months later indicate that the curvilinear association between OCB and task performance is significantly moderated by employees' time management skill. Implications for theory and practice are discussed.

  6. A comparison of finite difference methods for solving Laplace's equation on curvilinear coordinate systems. M.S. Thesis

    Science.gov (United States)

    Mccoy, M. J.

    1980-01-01

    Various finite difference techniques used to solve Laplace's equation are compared. Curvilinear coordinate systems are used on two dimensional regions with irregular boundaries, specifically, regions around circles and airfoils. Truncation errors are analyzed for three different finite difference methods. The false boundary method and two point and three point extrapolation schemes, used when having the Neumann boundary condition are considered and the effects of spacing and nonorthogonality in the coordinate systems are studied.

  7. Curvilinear Immersed Boundary Method for Simulating Fluid Structure Interaction with Complex 3D Rigid Bodies.

    Science.gov (United States)

    Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

    2008-08-10

    The sharp-interface CURVIB approach of Ge and Sotiropoulos [L. Ge, F. Sotiropoulos, A Numerical Method for Solving the 3D Unsteady Incompressible Navier-Stokes Equations in Curvilinear Domains with Complex Immersed Boundaries, Journal of Computational Physics 225 (2007) 1782-1809] is extended to simulate fluid structure interaction (FSI) problems involving complex 3D rigid bodies undergoing large structural displacements. The FSI solver adopts the partitioned FSI solution approach and both loose and strong coupling strategies are implemented. The interfaces between immersed bodies and the fluid are discretized with a Lagrangian grid and tracked with an explicit front-tracking approach. An efficient ray-tracing algorithm is developed to quickly identify the relationship between the background grid and the moving bodies. Numerical experiments are carried out for two FSI problems: vortex induced vibration of elastically mounted cylinders and flow through a bileaflet mechanical heart valve at physiologic conditions. For both cases the computed results are in excellent agreement with benchmark simulations and experimental measurements. The numerical experiments suggest that both the properties of the structure (mass, geometry) and the local flow conditions can play an important role in determining the stability of the FSI algorithm. Under certain conditions unconditionally unstable iteration schemes result even when strong coupling FSI is employed. For such cases, however, combining the strong-coupling iteration with under-relaxation in conjunction with the Aitken's acceleration technique is shown to effectively resolve the stability problems. A theoretical analysis is presented to explain the findings of the numerical experiments. It is shown that the ratio of the added mass to the mass of the structure as well as the sign of the local time rate of change of the force or moment imparted on the structure by the fluid determine the stability and convergence of the FSI

  8. In vivo visualization of robotically implemented synthetic tracked aperture ultrasound (STRATUS) imaging system using curvilinear array

    Science.gov (United States)

    Zhang, Haichong K.; Aalamifar, Fereshteh; Boctor, Emad M.

    2016-04-01

    Synthetic aperture for ultrasound is a technique utilizing a wide aperture in both transmit and receive to enhance the ultrasound image quality. The limitation of synthetic aperture is the maximum available aperture size limit determined by the physical size of ultrasound probe. We propose Synthetic-Tracked Aperture Ultrasound (STRATUS) imaging system to overcome the limitation by extending the beamforming aperture size through ultrasound probe tracking. With a setup involving a robotic arm, the ultrasound probe is moved using the robotic arm, while the positions on a scanning trajectory are tracked in real-time. Data from each pose are synthesized to construct a high resolution image. In previous studies, we have demonstrated the feasibility through phantom experiments. However, various additional factors such as real-time data collection or motion artifacts should be taken into account when the in vivo target becomes the subject. In this work, we build a robot-based STRATUS imaging system with continuous data collection capability considering the practical implementation. A curvilinear array is used instead of a linear array to benefit from its wider capture angle. We scanned human forearms under two scenarios: one submerged the arm in the water tank under 10 cm depth, and the other directly scanned the arm from the surface. The image contrast improved 5.51 dB, and 9.96 dB for the underwater scan and the direct scan, respectively. The result indicates the practical feasibility of STRATUS imaging system, and the technique can be potentially applied to the wide range of human body.

  9. GCLgrid: A three-dimensional geographical curvilinear grid library for computational seismology

    Science.gov (United States)

    Fan, Chengliang; Pavlis, Gary L.; Tuncay, Kagan

    2006-04-01

    We developed a general library for handling a class of objects we call geographical curvilinear grids (GCLgrids). A GCLgrid is a distorted, uniform grid that is georeferenced. The GCLgrid library is implemented in an object oriented system with methods that relate points in the grid to a geographic reference frame. A simple example is a spherical shell divided along latitude, longitude, and depth, but more elaborate shapes can use the same interface. Scalar and vector fields are derived from the base grid through inheritance. Two algorithms are the core of this library. First, we use the Direction Set method to search for a location in space from a starting point. This algorithm converges reasonably fast if the grid is not extremely distorted. Second, we interpolate the grid using methods known from finite element analysis. A Jacobian matrix for an 8-node cube is computed to transform a distorted cube into a unit one. Shape functions for the standard cube are used to compute interpolation coefficients. Once the interpolation coefficients are computed, we can interpolate n-element vectors almost as quickly as scalar data. We show an application of the library to travel time table calculation at regional distances. Our table interpolator was found to be 10 times faster than one based on the tau-p method and is expected to be several orders of magnitude faster than 3D ray-tracing methods. Travel time interpolation errors are reduced significantly by tabulating delay times relative to a homogenous reference model instead of absolute times. This allows much coarser grids to be used at large scales comparing to one using total time.

  10. A numerical method for solving the 3D unsteady incompressible Navier Stokes equations in curvilinear domains with complex immersed boundaries

    Science.gov (United States)

    Ge, Liang; Sotiropoulos, Fotis

    2007-08-01

    A novel numerical method is developed that integrates boundary-conforming grids with a sharp interface, immersed boundary methodology. The method is intended for simulating internal flows containing complex, moving immersed boundaries such as those encountered in several cardiovascular applications. The background domain (e.g. the empty aorta) is discretized efficiently with a curvilinear boundary-fitted mesh while the complex moving immersed boundary (say a prosthetic heart valve) is treated with the sharp-interface, hybrid Cartesian/immersed-boundary approach of Gilmanov and Sotiropoulos [A. Gilmanov, F. Sotiropoulos, A hybrid cartesian/immersed boundary method for simulating flows with 3d, geometrically complex, moving bodies, Journal of Computational Physics 207 (2005) 457-492.]. To facilitate the implementation of this novel modeling paradigm in complex flow simulations, an accurate and efficient numerical method is developed for solving the unsteady, incompressible Navier-Stokes equations in generalized curvilinear coordinates. The method employs a novel, fully-curvilinear staggered grid discretization approach, which does not require either the explicit evaluation of the Christoffel symbols or the discretization of all three momentum equations at cell interfaces as done in previous formulations. The equations are integrated in time using an efficient, second-order accurate fractional step methodology coupled with a Jacobian-free, Newton-Krylov solver for the momentum equations and a GMRES solver enhanced with multigrid as preconditioner for the Poisson equation. Several numerical experiments are carried out on fine computational meshes to demonstrate the accuracy and efficiency of the proposed method for standard benchmark problems as well as for unsteady, pulsatile flow through a curved, pipe bend. To demonstrate the ability of the method to simulate flows with complex, moving immersed boundaries we apply it to calculate pulsatile, physiological flow

  11. Inverted U-Shaped Curvilinear Relationship between Challenge and One's Intrinsic Motivation: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Ma, Qingguo; Pei, Guanxiong; Meng, Liang

    2017-01-01

    The balance between task demand and one's competence is critical for the maintenance of intrinsic motivation. According to Flow theory and Self-determination theory, optimal challenge gives rise to the maximum intrinsic motivation, and an inverted U-shaped curvilinear relationship between perceived challenge and one's intrinsic motivation is suggested. In order to provide direct experimental evidences for predictions of these theories, in this study, we employed the two-player StopWatch game that we previously designed, which made references to the game format of a badminton tournament. According to our manipulation, a male participant was defeated by the same-sex player paired with him (played by a well-trained confederate of the experimenter) in two matches, one with a wide margin (the complete defeat condition) and another with a narrow one (the near miss condition). Participants performed better and reported to enjoy the near miss match to a greater extent. Besides, an enlarged Stimulus-preceding negativity was elicited when participants were actively anticipating outcomes in the near miss condition, suggesting greater anticipatory attention toward the outcome and an enhanced intrinsic motivation to win. Thus, converging electrophysiological evidences from this study and our former study confirmed the inverted U-shaped curvilinear relationship between perceived challenge and one's intrinsic motivation.

  12. Numerical simulation of four-field extended magnetohydrodynamics in dynamically adaptive curvilinear coordinates via Newton-Krylov-Schwarz

    KAUST Repository

    Yuan, Xuefei

    2012-07-01

    Numerical simulations of the four-field extended magnetohydrodynamics (MHD) equations with hyper-resistivity terms present a difficult challenge because of demanding spatial resolution requirements. A time-dependent sequence of . r-refinement adaptive grids obtained from solving a single Monge-Ampère (MA) equation addresses the high-resolution requirements near the . x-point for numerical simulation of the magnetic reconnection problem. The MHD equations are transformed from Cartesian coordinates to solution-defined curvilinear coordinates. After the application of an implicit scheme to the time-dependent problem, the parallel Newton-Krylov-Schwarz (NKS) algorithm is used to solve the system at each time step. Convergence and accuracy studies show that the curvilinear solution requires less computational effort than a pure Cartesian treatment. This is due both to the more optimal placement of the grid points and to the improved convergence of the implicit solver, nonlinearly and linearly. The latter effect, which is significant (more than an order of magnitude in number of inner linear iterations for equivalent accuracy), does not yet seem to be widely appreciated. © 2012 Elsevier Inc.

  13. Curvilinear 3-D Imaging Using Row--Column-Addressed 2-D Arrays with a Diverging Lens: Feasibility Study

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Beers, Christopher

    2017-01-01

    imaging. Extended FOV and low channel count of double-curved RCA 2-D arrays make 3-D imaging possible with equipment in the price range of conventional 2-D imaging. This study proposes a delay-and-sum beamformation scheme specific to double-curved RCA 2-D arrays and validates its focusing ability based...... on simulations. A synthetic aperture imaging sequence with single element transmissions is designed for imaging down to 14 cm at a volume rate of 88 Hz. Using a diverging lens with f-number of -1 circumscribing the underlying RCA array, the imaging quality of a double-curved λ/2-pitch 3 MHz 62+62 RCA 2-D array...... is investigated as a function of depth within a curvilinear FOV of 60°×60°. The simulated double-curved 2-D array exhibits the same full-width-at-halfmaximum values for a point scatterer within its curvilinear FOV at a fixed radial distance compared with a flat 2-D array within its rectilinear FOV. The results...

  14. Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

    Science.gov (United States)

    Shimazu, Akihito; Matsudaira, Ko; Jonge, Jan DE; Tosaka, Naoya; Watanabe, Kazuhiro; Takahashi, Masaya

    2016-06-10

    This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement.

  15. Development and application of the discrete ordinate method in orthogonal curvilinear coordinates; Developpement et application de la methode des ordonnees discretes en coordonnees curvilignes orthogonales

    Energy Technology Data Exchange (ETDEWEB)

    Vaillon, R.; Lallemand, M.; Lemonnier, D. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France)

    1996-12-31

    The method of discrete ordinates, which is more and more widely used in radiant heat transfer studies, is mainly developed in Cartesian, (r,z) and (r,{Theta}) cylindrical, and spherical coordinates. In this study, the approach of this method is performed in orthogonal curvilinear coordinates: determination of the radiant heat transfer equation, treatment of the angular redistribution terms, numerical procedure. Some examples of application are described in 2-D geometry defined in curvilinear coordinates along a curve and at the thermal equilibrium. A comparison is made with the discrete ordinates method in association with the finite-volumes method in non structured mesh. (J.S.) 27 refs.

  16. Hierarchical expansion of the kinetic energy operator in curvilinear coordinates for the vibrational self-consistent field method.

    Science.gov (United States)

    Strobusch, D; Scheurer, Ch

    2011-09-28

    A new hierarchical expansion of the kinetic energy operator in curvilinear coordinates is presented and modified vibrational self-consistent field (VSCF) equations are derived including all kinematic effects within the mean field approximation. The new concept for the kinetic energy operator is based on many-body expansions for all G matrix elements and its determinant. As a test application VSCF computations were performed on the H(2)O(2) molecule using an analytic potential (PCPSDE) and different hierarchical approximations for the kinetic energy operator. The results indicate that coordinate-dependent reduced masses account for the largest part of the kinetic energy. Neither kinematic couplings nor derivatives of the G matrix nor its determinant had significant effects on the VSCF energies. Only the zero-point value of the pseudopotential yields an offset to absolute energies which, however, is irrelevant for spectroscopic problems.

  17. Three-dimensional ray tracing through curvilinear interfaces with application to laser Doppler anemometry in a blood analogue fluid.

    Science.gov (United States)

    Nugent, Allen H; Bertram, Christopher D

    2010-02-01

    Prediction of the effects of refractive index (RI) mismatch on laser Doppler anemometer (LDA) measurements within a curvilinear cavity (an artificial ventricle) was achieved by developing a general technique for modelling the paths of the convergent beams of the LDA system using 3D vector geometry. Validated by ray tracing through CAD drawings, the predicted maximum tolerance in RI between the solid model and the working fluid was +/- 0.0005, equivalent to focusing errors commensurate with the geometric and alignment uncertainties associated with the flow model and the LDA arrangement. This technique supports predictions of the effects of refraction within a complex geometry. Where the RI mismatch is unavoidable but known, it is possible not only to calculate the true position of the measuring volume (using the probe location and model geometry), but also to estimate degradation in signal quality arising from differential displacement and refraction of the laser beams.

  18. Dispersive Stabilization of Liquid Crystal-in-Water with Acrylamide Copolymer/Surfactant Mixture: Nematic Curvilinear Aligned Phase Composite Film.

    Science.gov (United States)

    Park; Lee

    1999-11-01

    The effect of nonionic surfactant, (H(OCH(2)-CH(2))(8)-OC(6)H(4)-C(9)H(19)), on the dispersion stabilization of liquid crystal (LC)-in-water with acrylamide copolymer containing the related nonylphenyl groups was studied. It was observed that the addition of nonionic surfactant increases the stability of LC dispersions and improves the electrooptical properties of the nematic curvilinear aligned phase (NCAP) composite film. On the basis of the surface tension, reduced viscosity, cloud point, and coalescence time measurements, it was proposed that formation of an integrated structure induced by interactions between hydrophobic groups in the polymer chains is probably important to fabrication of a polymer composite film made of LC and polymer matrix. Copyright 1999 Academic Press.

  19. Automatic differentiation method for numerical construction of the rotational-vibrational Hamiltonian as a power series in the curvilinear internal coordinates using the Eckart frame

    Science.gov (United States)

    Yachmenev, Andrey; Yurchenko, Sergei N.

    2015-07-01

    We present a new numerical method to construct a rotational-vibrational Hamiltonian of a general polyatomic molecule in the Eckart frame as a power series expansion in terms of curvilinear internal coordinates. The expansion of the kinetic energy operator of an arbitrary order is obtained numerically using an automatic differentiation (AD) technique. The method is applicable to molecules of arbitrary size and structure and is flexible for choosing various types of internal coordinates. A new way of solving the Eckart-frame equations for curvilinear coordinates also based on the AD technique is presented. The resulting accuracy of the high-order expansion coefficients for the kinetic energy operator using our numerical technique is comparable to that obtained by symbolic differentiation, with the advantage of being faster and less demanding in memory. Examples for H2CO, NH3, PH3, and CH3Cl molecules demonstrate the advantages of the curvilinear internal coordinates and the Eckart molecular frame for accurate ro-vibrational calculations. Our results show that very high accuracy and quick convergence can be achieved even with moderate expansions if curvilinear coordinates are employed, which is important for applications involving large polyatomic molecules.

  20. Automatic differentiation method for numerical construction of the rotational-vibrational Hamiltonian as a power series in the curvilinear internal coordinates using the Eckart frame.

    Science.gov (United States)

    Yachmenev, Andrey; Yurchenko, Sergei N

    2015-07-07

    We present a new numerical method to construct a rotational-vibrational Hamiltonian of a general polyatomic molecule in the Eckart frame as a power series expansion in terms of curvilinear internal coordinates. The expansion of the kinetic energy operator of an arbitrary order is obtained numerically using an automatic differentiation (AD) technique. The method is applicable to molecules of arbitrary size and structure and is flexible for choosing various types of internal coordinates. A new way of solving the Eckart-frame equations for curvilinear coordinates also based on the AD technique is presented. The resulting accuracy of the high-order expansion coefficients for the kinetic energy operator using our numerical technique is comparable to that obtained by symbolic differentiation, with the advantage of being faster and less demanding in memory. Examples for H2CO, NH3, PH3, and CH3Cl molecules demonstrate the advantages of the curvilinear internal coordinates and the Eckart molecular frame for accurate ro-vibrational calculations. Our results show that very high accuracy and quick convergence can be achieved even with moderate expansions if curvilinear coordinates are employed, which is important for applications involving large polyatomic molecules.

  1. Curvilinear transformation of z-shaped upper lip scar by diamond-shaped excision in secondary cleft lip deformities: a photogrammetric evaluation.

    Science.gov (United States)

    Han, Kihwan; Jeong, Hoijoon; Choi, Tae Hyun; Kim, Jun Hyung; Son, Daegu

    2015-03-01

    Purpose : The visible Z-shaped upper lip scar that occurs after the Tennison and Randall triangular flap technique remains a cleft stigma. Herein, we present our curvilinear transformation technique for the Z-shaped upper lip scar by diamond-shaped excision and evaluate the results using photogrammetric analyses. Patients and Methods : From 1997 to 2006, 23 patients with secondary cleft lip deformity with the visible Z-shaped upper lip scar underwent correction with the technique. The scar was excised in the diamond shape above the muscle. After curvilinear closure, the elongated length of the upper lip was excised just below the nostril sill, as the measured Cupid's bow height discrepancy. The result was assessed by the authors' standardized photogrammetry technique. Results : There was a statistically significant decrease between the preoperative central limb of the Z-shaped scar and the width of the postoperative curvilinear upper lip scar. The pre- and postoperative Cupid's bow height differences were not statistically significant. Conclusions : The curvilinear transformation of the Z-shaped scar is an efficient procedure that provides (1) a significant decrease in the width of an upper lip scar to make it less conspicuous, (2) incorporation of the scar into the philtral column, (3) a biconcave natural philtral column shape in frontal view, and (4) formation of the natural concave philtral contour in profile view.

  2. The curvilinear relationship between work pressure and momentary task performance: The role of state and trait Core Self-Evaluations

    Directory of Open Access Journals (Sweden)

    Joeri eHofmans

    2015-10-01

    Full Text Available Whereas several studies have demonstrated that Core Self-Evaluations (CSE–or one’s appraisals about one’s own self-worth, capabilities, and competences–relate to job outcomes, less is known about the mechanisms underlying these relationships. In the present study, we address this issue by examining the role of within- and between-person variation in CSE in the relationship between work pressure and task performance. We hypothesized that (a work pressure relates to task performance in a curvilinear way, (b state CSE mediates the curvilinear relationship between work pressure and task performance, and (c the relationship between work pressure and state CSE is moderated by trait CSE. Our hypotheses were tested via a ten-day daily diary study with 55 employees in which trait CSE was measured at baseline, while work pressure, task performance, and state CSE were assessed on a daily basis. Bayesian multilevel path analysis showed that work pressure affects task performance via state CSE, with state CSE increasing as long as the employee feels that (she is able to handle the work pressure, while it decreases when the level of work pressure exceeds the employees’ coping abilities. Moreover, we found that for people low on trait CSE, the depleting effect of work pressure via state CSE happens for low levels of work pressure, while for people high in trait CSE the depleting effect is located at high levels of work pressure. Together, our findings suggest that the impact of work pressure on task performance is driven by a complex interplay of between- and within-person differences in CSE.

  3. The curvilinear relationship between work pressure and momentary task performance: the role of state and trait core self-evaluations.

    Science.gov (United States)

    Hofmans, Joeri; Debusscher, Jonas; Dóci, Edina; Spanouli, Andromachi; De Fruyt, Filip

    2015-01-01

    Whereas several studies have demonstrated that core self-evaluations (CSE)-or one's appraisals about one's own self-worth, capabilities, and competences-relate to job outcomes, less is known about the mechanisms underlying these relationships. In the present study, we address this issue by examining the role of within- and between-person variation in CSE in the relationship between work pressure and task performance. We hypothesized that (a) work pressure relates to task performance in a curvilinear way, (b) state CSE mediates the curvilinear relationship between work pressure and task performance, and (c) the relationship between work pressure and state CSE is moderated by trait CSE. Our hypotheses were tested via a 10-day daily diary study with 55 employees in which trait CSE was measured at baseline, while work pressure, task performance, and state CSE were assessed on a daily basis. Bayesian multilevel path analysis showed that work pressure affects task performance via state CSE, with state CSE increasing as long as the employee feels that (s)he is able to handle the work pressure, while it decreases when the level of work pressure exceeds the employees' coping abilities. Moreover, we found that for people low on trait CSE, the depleting effect of work pressure via state CSE happens for low levels of work pressure, while for people high in trait CSE the depleting effect is located at high levels of work pressure. Together, our findings suggest that the impact of work pressure on task performance is driven by a complex interplay of between- and within-person differences in CSE.

  4. Long-term job insecurity, job satisfaction and organisational attitudes: Test of Warr’s Curvilinear Hypothesis

    Directory of Open Access Journals (Sweden)

    Hans De Witte

    2005-10-01

    Full Text Available Research suggests that job insecurity is an important work stressor, negatively affecting well-being and organisational attitudes and behaviours. This article concentrates on two often ignored issues in this field. First, the consequences of long-term job insecurity regarding job satisfaction, the evaluation of management and organisational attitudes are analysed. Secondly, Warr’s assumption of curvilinear associations between job insecurity and well-being is tested, and extended to the evaluation of management and organisational attitudes. The hypotheses are tested with data of 769 employees from various branches of a large European multinational company. In total, 15 reliable scales were used to test the hypotheses. The results show that 48,2% of the interviewees had worries about their long-term job security. Separate analyses of variance showed that long-term job insecurity was associated with two thirds of the scales. Long-term job insecurity was associated with lower job satisfaction, lower organisational attitudes and a lower evaluation of supervisors and management. Warr’s assumption of curvilinear associations with job insecurity was not corroborated, however. Suggestions for practice and for future research are discussed. Opsomming Navorsing stel voor dat werksonsekerheid ’n belangrike werk stressor is en dat dit welstand, organisasie gesindhede en gedrag negetief affekteer. Die artikel konsentreer op twee onderwerpe in hierdie veld wat gereeld geignoreer word. Eerstens word die gevolge van langtermyn werksonsekerheid met betrekking tot werkstevredenheid, die evaluering van bestuur en organisasiegesindhede geanaliseer. Tweedens, is Warr se aanames van kromlynige verhoudings tussen werksonsekerheid en welstand getoets, en uitgebrei tot die evaluasie van bestuur en organisasiegesindhede. Die hipotese is getoets met data van 769 werknemers van verskeie takke van ’n groot Europese multinasionale maatskappy. Daar is in totaal 15

  5. A three-dimensional k-ε-kp model in curvilinear coordinates for sediment movement and bed evolution

    Institute of Scientific and Technical Information of China (English)

    SHEN YongMing; LIU Cheng

    2009-01-01

    To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load transport in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying water-sediment movements and bed evolution in a 120° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kpmodel is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model.

  6. A three-dimensional k-ε-k_p model in curvilinear coordinates for sediment movement and bed evolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    To aim at the substitution of the magnitude and direction of water flow movement near bed for those of bed load transport in solid-liquid two-phase one-fluid model, and to simulate the effect of secondary flow on transverse bed load transport in channel bends and the effect of bed slope on bed load trans- port in a better way, a three-dimensional k-ε-kp solid-liquid two-phase two-fluid model in curvilinear coordinates is solved numerically with a finite-volume method on an adaptive grid for studying wa- ter-sediment movements and bed evolution in a 120° channel bend. Numerical results show that the trajectories of solid-phase deviate from those of liquid-phase in the channel bend, and the deviation increases with the increase of the particle diameters. The calculated bed deformation by the k-ε-kp model is in better agreement with measured bed deformation than those by one-fluid model. It is proved that the k-ε-kp model can simulate the effect of secondary flow on lateral bed load transport with the higher accuracy than the one-fluid model.

  7. Documentation of program AFTBDY to generate coordinate system for 3D after body using body fitted curvilinear coordinates, part 1

    Science.gov (United States)

    Kumar, D.

    1980-01-01

    The computer program AFTBDY generates a body fitted curvilinear coordinate system for a wedge curved after body. This wedge curved after body is being used in an experimental program. The coordinate system generated by AFTBDY is used to solve 3D compressible N.S. equations. The coordinate system in the physical plane is a cartesian x,y,z system, whereas, in the transformed plane a rectangular xi, eta, zeta system is used. The coordinate system generated is such that in the transformed plane coordinate spacing in the xi, eta, zeta direction is constant and equal to unity. The physical plane coordinate lines in the different regions are clustered heavily or sparsely depending on the regions where physical quantities to be solved for by the N.S. equations have high or low gradients. The coordinate distribution in the physical plane is such that x stays constant in eta and zeta direction, whereas, z stays constant in xi and eta direction. The desired distribution in x and z is input to the program. Consequently, only the y-coordinate is solved for by the program AFTBDY.

  8. Apsara: A multi-dimensional unsplit fourth-order explicit Eulerian hydrodynamics code for arbitrary curvilinear grids

    CERN Document Server

    Wongwathanarat, Annop; Müller, Ewald

    2016-01-01

    We present a new fourth-order finite-volume hydrodynamics code named Apsara. The code employs the high-order finite-volume method for mapped coordinates developed by Colella et al. (2011) with extensions for non-linear hyperbolic conservation laws by McCorquodale & Colella (2011) and Guzik et al. (2012). Using the mapped-grid technique Apsara can handle arbitrary structured curvilinear meshes in three spatial dimensions. The code has successfully passed several hydrodynamic test problems including the advection of a Gaussian density profile and a non-linear vortex, as well as the propagation of linear acoustic waves. For these test problems Apsara produces fourth-order accurate results in case of smooth grid mappings. The order of accuracy is reduced to first-order when using the non-smooth circular grid mapping of Calhoun et al. (2008). When applying the high-order method by McCorquodale & Colella (2011) to simulations of low-Mach number flows, e.g. the Gresho vortex and the Taylor-Green vortex, we d...

  9. APSARA: A multi-dimensional unsplit fourth-order explicit Eulerian hydrodynamics code for arbitrary curvilinear grids

    Science.gov (United States)

    Wongwathanarat, A.; Grimm-Strele, H.; Müller, E.

    2016-10-01

    We present a new fourth-order, finite-volume hydrodynamics code named Apsara. The code employs a high-order, finite-volume method for mapped coordinates with extensions for nonlinear hyperbolic conservation laws. Apsara can handle arbitrary structured curvilinear meshes in three spatial dimensions. The code has successfully passed several hydrodynamic test problems, including the advection of a Gaussian density profile and a nonlinear vortex and the propagation of linear acoustic waves. For these test problems, Apsara produces fourth-order accurate results in case of smooth grid mappings. The order of accuracy is reduced to first-order when using the nonsmooth circular grid mapping. When applying the high-order method to simulations of low-Mach number flows, for example, the Gresho vortex and the Taylor-Green vortex, we discover that Apsara delivers superior results to codes based on the dimensionally split, piecewise parabolic method (PPM) widely used in astrophysics. Hence, Apsara is a suitable tool for simulating highly subsonic flows in astrophysics. In the first astrophysical application, we perform implicit large eddy simulations (ILES) of anisotropic turbulence in the context of core collapse supernova (CCSN) and obtain results similar to those previously reported.

  10. Coupling of Dirichlet-to-Neumann boundary condition and finite difference methods in curvilinear coordinates for multiple scattering

    Science.gov (United States)

    Acosta, Sebastian; Villamizar, Vianey

    2010-08-01

    The applicability of the Dirichlet-to-Neumann technique coupled with finite difference methods is enhanced by extending it to multiple scattering from obstacles of arbitrary shape. The original boundary value problem (BVP) for the multiple scattering problem is reformulated as an interface BVP. A heterogenous medium with variable physical properties in the vicinity of the obstacles is considered. A rigorous proof of the equivalence between these two problems for smooth interfaces in two and three dimensions for any finite number of obstacles is given. The problem is written in terms of generalized curvilinear coordinates inside the computational region. Then, novel elliptic grids conforming to complex geometrical configurations of several two-dimensional obstacles are constructed and approximations of the scattered field supported by them are obtained. The numerical method developed is validated by comparing the approximate and exact far-field patterns for the scattering from two circular obstacles. In this case, for a second order finite difference scheme, a second order convergence of the numerical solution to the exact solution is easily verified.

  11. Variable conformation of GAP junctions linking bone cells: a transmission electron microscopic study of linear, stacked linear, curvilinear, oval, and annular junctions.

    Science.gov (United States)

    Shapiro, F

    1997-10-01

    There is a marked variability in the conformation of bone cell gap junctions in newborn murine cortical bone as defined by transmission electron microscopy (TEM). Studies were done in newborn BALB/c mouse and Sprague-Dawley rat femurs and tibias. Femoral and tibial cortices were dissected into 1 mm3 fragments and prepared in standardized fashion using modified Karnovsky fixation, 7.5% EDTA decalcification, 1% osmium tetroxide-sym collidine buffer with 1% lanthanum nitrate postfixation, Epon resin, 60 nm sections, lead citrate/uranyl acetate staining, and examination at 60 kV. Previous TEM descriptions of bone junctions have, with rare exceptions, noted only isolated linear or mildly curvilinear structures. In this study we noted gap junctional shapes on thin-section TEM preparations of osteoblasts and osteocytes to be extremely variable and complex encompassing linear, curvilinear, stacked linear, oval, and annular conformations. Multiple observations revealed linear gap junctions linking surface osteoblast cell bodies; linear, curvilinear, stacked linear, and oval junctions linking osteoblast processes in osteoid; linear and curvilinear junctions where cell processes joined with osteocyte cell bodies and each of the five conformations linking osteocyte processes within canaliculi. The annular junctions were found within osteoblast and osteocyte cytoplasm and in osteocyte cell processes within canaliculi. The annular junctions are intracellular, degenerating structures which appear as ultrastructural markers of gap junction involution. The more complex shapes reported here must be considered in (1) interpreting quantitative studies using freeze-fracture replicas, thin sections, and confocal microscopy immunolabeled junction connexin-43 components and (2) assessing gap junction biogenesis and turnover. 3-D reconstruction of bone junctions will enhance our understanding of these complex conformations.

  12. High-order weighted essentially nonoscillatory finite-difference formulation of the lattice Boltzmann method in generalized curvilinear coordinates

    Science.gov (United States)

    Hejranfar, Kazem; Saadat, Mohammad Hossein; Taheri, Sina

    2017-02-01

    In this work, a high-order weighted essentially nonoscillatory (WENO) finite-difference lattice Boltzmann method (WENOLBM) is developed and assessed for an accurate simulation of incompressible flows. To handle curved geometries with nonuniform grids, the incompressible form of the discrete Boltzmann equation with the Bhatnagar-Gross-Krook (BGK) approximation is transformed into the generalized curvilinear coordinates and the spatial derivatives of the resulting lattice Boltzmann equation in the computational plane are solved using the fifth-order WENO scheme. The first-order implicit-explicit Runge-Kutta scheme and also the fourth-order Runge-Kutta explicit time integrating scheme are adopted for the discretization of the temporal term. To examine the accuracy and performance of the present solution procedure based on the WENOLBM developed, different benchmark test cases are simulated as follows: unsteady Taylor-Green vortex, unsteady doubly periodic shear layer flow, steady flow in a two-dimensional (2D) cavity, steady cylindrical Couette flow, steady flow over a 2D circular cylinder, and steady and unsteady flows over a NACA0012 hydrofoil at different flow conditions. Results of the present solution are compared with the existing numerical and experimental results which show good agreement. To show the efficiency and accuracy of the solution methodology, the results are also compared with the developed second-order central-difference finite-volume lattice Boltzmann method and the compact finite-difference lattice Boltzmann method. It is shown that the present numerical scheme is robust, efficient, and accurate for solving steady and unsteady incompressible flows even at high Reynolds number flows.

  13. Quartic canonical force field in curvilinear internal coordinates for XY3 (D3h) molecules. The case of the BH3 molecule.

    Science.gov (United States)

    Ródenas, Consuelo Rosales; Quesada, Juana Vázquez; Torres, Emilio Martínez; González, Juan Jesús López

    2014-06-01

    Using the canonical force field theory, expressions of quadratic, cubic, and quartic canonical force constants are obtained for XY3 (D3h) molecules in curvilinear redundant coordinates, i.e., simple valence internal coordinates (VICs), in terms of force constants in normal coordinates and in independent symmetry coordinates. To carry out this task, it was previously necessary to obtain for the first time the non-linear redundancy relation and the corresponding orthogonal projection onto the pure vibrational manifold for XY3 (D3h) molecules corresponding to a set of seven VICs. As an application, the quartic canonical force field in curvilinear redundant internal coordinates of BH3 is determined from ab initio force fields in normal coordinates calculated at the coupled-cluster singles and doubles level with perturbative treatment of the triples in conjunction with a triple- and quadruple-ζ size basis set. This anharmonic force field so obtained for the borane molecule, and in general for XY3 (D3h) molecules, is uniquely defined (therefore in an unambiguous form) and depending on the same number of parameters, i.e., force constants, when independent coordinates (natural or symmetry) are used in its description.

  14. Linear and curvilinear correlations of brain gray matter volume and density with age using voxel-based morphometry with the Akaike information criterion in 291 healthy children.

    Science.gov (United States)

    Taki, Yasuyuki; Hashizume, Hiroshi; Thyreau, Benjamin; Sassa, Yuko; Takeuchi, Hikaru; Wu, Kai; Kotozaki, Yuka; Nouchi, Rui; Asano, Michiko; Asano, Kohei; Fukuda, Hiroshi; Kawashima, Ryuta

    2013-08-01

    We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure.

  15. Innovative design of composite structures: The use of curvilinear fiber format to improve buckling resistance of composite plates with central circular holes

    Science.gov (United States)

    Hyer, M. W.; Lee, H. H.

    1990-01-01

    The gains in buckling performance are explored that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point. The particular situation studied is a simply supported square plate with a centrally located hole loaded in compression. By using both a sensitivity analysis and a gradient-search technique, fiber orientation in a number of regions of the plate are selected so as to increase the buckling load relative to baseline straightline designs. The sensitivity analysis is used to determine which regions of the plate have the most influence on buckling load, and the gradient search is used to find the design that is believed to represent the absolute maximum buckling load for the conditions prescribed. Convergence studies and sensitivity of the final design are discussed. By examining the stress resultant contours, it is shown how the curvilinear fibers move the load away from the unsupported hole region of the plate to the supported edges, thus increasing the buckling capacity. The tensile capacity of the improved buckling design is investigated, and it is shown that both tensile capacity and buckling capacity can be improved with the curvilinear fiber concept.

  16. Stable, high-order SBP-SAT finite difference operators to enable accurate simulation of compressible turbulent flows on curvilinear grids, with application to predicting turbulent jet noise

    Science.gov (United States)

    Byun, Jaeseung; Bodony, Daniel; Pantano, Carlos

    2014-11-01

    Improved order-of-accuracy discretizations often require careful consideration of their numerical stability. We report on new high-order finite difference schemes using Summation-By-Parts (SBP) operators along with the Simultaneous-Approximation-Terms (SAT) boundary condition treatment for first and second-order spatial derivatives with variable coefficients. In particular, we present a highly accurate operator for SBP-SAT-based approximations of second-order derivatives with variable coefficients for Dirichlet and Neumann boundary conditions. These terms are responsible for approximating the physical dissipation of kinetic and thermal energy in a simulation, and contain grid metrics when the grid is curvilinear. Analysis using the Laplace transform method shows that strong stability is ensured with Dirichlet boundary conditions while weaker stability is obtained for Neumann boundary conditions. Furthermore, the benefits of the scheme is shown in the direct numerical simulation (DNS) of a Mach 1.5 compressible turbulent supersonic jet using curvilinear grids and skew-symmetric discretization. Particularly, we show that the improved methods allow minimization of the numerical filter often employed in these simulations and we discuss the qualities of the simulation.

  17. Ab initio effective rotational and rovibrational Hamiltonians for non-rigid systems via curvilinear second order vibrational M{\\o}ller-Plesset perturbation theory

    CERN Document Server

    Changala, P Bryan

    2016-01-01

    We present a perturbative method for ab initio calculations of rotational and rovibrational effective Hamiltonians of both rigid and non-rigid molecules. Our approach is based on a curvilinear implementation of second order vibrational M{\\o}ller-Plesset perturbation theory (VMP2) extended to include rotational effects via a second order contact transformation. Though more expensive, this approach is significantly more accurate than standard second order vibrational perturbation theory (VPT2) for systems that are poorly described to zeroth order by rectilinear normal mode harmonic oscillators. We apply this method and demonstrate its accuracy on two molecules: Si$_2$C, a quasilinear triatomic with significant bending anharmonicity, and CH$_3$NO$_2$, which contains a completely unhindered methyl rotor. In addition to these two examples, we discuss several key technical aspects of the method, including an efficient implementation of Eckart and quasi-Eckart frame embedding that does not rely on numerical finite d...

  18. Identifying Essential Features of Juvenile Psychopathy in the Prediction of Later Antisocial Behavior: Is There an Additive, Synergistic, or Curvilinear Role for Fearless Dominance?

    Science.gov (United States)

    Vize, Colin E; Lynam, Donald R; Lamkin, Joanna; Miller, Joshua D; Pardini, Dustin

    2016-05-01

    Despite years of research, and inclusion of psychopathy DSM-5, there remains debate over the fundamental components of psychopathy. Although there is agreement about traits related to Agreeableness and Conscientiousness, there is less agreement about traits related to Fearless Dominance (FD) or Boldness. The present paper uses proxies of FD and Self-centered Impulsivity (SCI) to examine the contribution of FD-related traits to the predictive utility of psychopathy in a large, longitudinal, sample of boys to test four possibilities: FD 1. assessed earlier is a risk factor, 2. interacts with other risk-related variables to predict later psychopathy, 3. interacts with SCI interact to predict outcomes, and 4. bears curvilinear relations to outcomes. SCI received excellent support as a measure of psychopathy in adolescence; however, FD was unrelated to criteria in all tests. It is suggested that FD be dropped from psychopathy and that future research focus on Agreeableness and Conscientiousness.

  19. Geometric Formulation for Euclidean Configuration Space in Curvilinear Coordinate Systems%欧几里得位形空间几何性质的曲线坐标表示磁

    Institute of Scientific and Technical Information of China (English)

    王勇; 张延芳; 陈英华

    2014-01-01

    The geometric formulation of Euclidean configuration spaces in curvilinear coordinate systems is studied through the first-order linear mapping between the rectangular coordinate system and curvilinear coordinate systems ,and according to the principle of covariance , the motion equation of the particle ,which is the covariant form of Newton’s second law ,can be drawn out .%通过直角坐标系和曲线坐标系之间的一阶线性映射,研究了欧几里得位形空间几何性质在曲线坐标系下的表示。根据协变性原理写出质点在曲线坐标系中的运动方程,该方程是牛顿第二定律的协变形式。

  20. The relationship between N-terminal pro-brain natriuretic peptide and risk for hospitalization and mortality is curvilinear in patients with chronic heart failure

    DEFF Research Database (Denmark)

    Schou, Morten; Gustafsson, Finn; Corell, Pernille

    2007-01-01

    BACKGROUND: N-terminal pro-brain natriuretic peptide (NT-proBNP) carries prognostic information in patients with chronic heart failure and predicts risk for mortality and cardiovascular events. It is unknown whether NT-proBNP predicts risk for hospitalization for any cause. Furthermore, a clinica......BACKGROUND: N-terminal pro-brain natriuretic peptide (NT-proBNP) carries prognostic information in patients with chronic heart failure and predicts risk for mortality and cardiovascular events. It is unknown whether NT-proBNP predicts risk for hospitalization for any cause. Furthermore...... of doubling NT-proBNP on adjusted hazard ratios was 1.56 (95% CI 1.32-1.85) for mortality and 1.19 (95% CI 1.09-1.31) for hospitalization. We observed a curvilinear relationship between NT-proBNP and risk for mortality and hospitalization in the whole range of NT-proBNP. CONCLUSIONS: N-terminal pro-brain...... natriuretic peptide predicts risk for hospitalization and mortality. A simple algorithm indicates that every time NT-proBNP is doubled, estimated hazard ratio for death increases by a factor of 1.56 (56%) and by a factor of 1.19 (19%) for hospitalization. Finally, the relationship between NT-proBNP and risk...

  1. Higher-order in time "quasi-unconditionally stable" ADI solvers for the compressible Navier-Stokes equations in 2D and 3D curvilinear domains

    CERN Document Server

    Bruno, Oscar

    2015-01-01

    This paper introduces alternating-direction implicit (ADI) solvers of higher order of time-accuracy (orders two to six) for the compressible Navier-Stokes equations in two- and three-dimensional curvilinear domains. The higher-order accuracy in time results from 1) An application of the backward differentiation formulae time-stepping algorithm (BDF) in conjunction with 2) A BDF-like extrapolation technique for certain components of the nonlinear terms (which makes use of nonlinear solves unnecessary), as well as 3) A novel application of the Douglas-Gunn splitting (which greatly facilitates handling of boundary conditions while preserving higher-order accuracy in time). As suggested by our theoretical analysis of the algorithms for a variety of special cases, an extensive set of numerical experiments clearly indicate that all of the BDF-based ADI algorithms proposed in this paper are "quasi-unconditionally stable" in the following sense: each algorithm is stable for all couples $(h,\\Delta t)$ of spatial and t...

  2. Momentum Deposition in Curvilinear Coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Cleveland, Mathew Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lowrie, Robert Byron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockefeller, Gabriel M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Kelly Glen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-03

    The momentum imparted into a material by thermal radiation deposition is an important physical process in astrophysics and inertial confinement fusion (ICF) simulations. In recent work we presented a new method of evaluating momentum deposition that relies on the combination of a time-averaged approximation and a numerical integration scheme. This approach robustly and efficiently evaluates the momentum deposition in spherical geometry. Future work will look to extend this approach to 2D cylindrical geometries.

  3. A Newton-Krylov method with an approximate analytical Jacobian for implicit solution of Navier-Stokes equations on staggered overset-curvilinear grids with immersed boundaries

    Science.gov (United States)

    Asgharzadeh, Hafez; Borazjani, Iman

    2017-02-01

    The explicit and semi-implicit schemes in flow simulations involving complex geometries and moving boundaries suffer from time-step size restriction and low convergence rates. Implicit schemes can be used to overcome these restrictions, but implementing them to solve the Navier-Stokes equations is not straightforward due to their non-linearity. Among the implicit schemes for non-linear equations, Newton-based techniques are preferred over fixed-point techniques because of their high convergence rate but each Newton iteration is more expensive than a fixed-point iteration. Krylov subspace methods are one of the most advanced iterative methods that can be combined with Newton methods, i.e., Newton-Krylov Methods (NKMs) to solve non-linear systems of equations. The success of NKMs vastly depends on the scheme for forming the Jacobian, e.g., automatic differentiation is very expensive, and matrix-free methods without a preconditioner slow down as the mesh is refined. A novel, computationally inexpensive analytical Jacobian for NKM is developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered overset-curvilinear grids with immersed boundaries. Moreover, the analytical Jacobian is used to form a preconditioner for matrix-free method in order to improve its performance. The NKM with the analytical Jacobian was validated and verified against Taylor-Green vortex, inline oscillations of a cylinder in a fluid initially at rest, and pulsatile flow in a 90 degree bend. The capability of the method in handling complex geometries with multiple overset grids and immersed boundaries is shown by simulating an intracranial aneurysm. It was shown that the NKM with an analytical Jacobian is 1.17 to 14.77 times faster than the fixed-point Runge-Kutta method, and 1.74 to 152.3 times (excluding an intensively stretched grid) faster than automatic differentiation depending on the grid (size) and the flow problem. In addition, it was shown that using only the

  4. Study on the numerical solutions of the eikonal equationin curvilinear coordinate system%曲线坐标系程函方程的求解方法研究

    Institute of Scientific and Technical Information of China (English)

    刘一峰; 兰海强

    2012-01-01

    The classical eikonal equation is commonly used in Cartesian coordinate system for problems that involve static correction, prestack migration, earthquake location and seismic tomography, but is less effective for calculating travel times in an earth model that has an irregular surface. We transform the eikonal equation to a curvilinear coordinate system that conforms with the boundaries of the domain. The eikonal equation in the curvilinear coordinate system displays the mathematical form of an anisotropic eikonal equations (even though the medium is isotropic in the Cartesian coordinate system). Then, we try to solve the anisotropic eikonal equations with two numerical methods, a simple modification of the fast marching method and Lax-Friedrichs fast sweeping method, respectively. Through a number of different numerical experiments we find- one may compute wrong solutions by extending fast marching methods designed for isotropic eikonal equations to anisotropic eikonal equations without taking into account the differences between them; the Lax-Friedrichs fast sweeping method is stable and valid for the eikonal equation in the curvilinear coordinate system, which has a significant meaning in the direction of solution of the eikonal equation in the curvilinear coordinate system.%笛卡尔坐标系中经典的程函方程在静校正、叠前偏移、走时反演、地震定位、层析成像等许多地球物理工作都有应用,然而用其计算起伏地表的地震波走时时却比较困难.我们通过把曲线坐标系中的矩形网格映射到笛卡尔坐标系的贴体网格推导出了曲线坐标中的程函方程,此时,曲线坐标系的程函方程呈现为各向异性的程函方程(尽管在笛卡尔坐标系中介质是各向同同性的).然后尝试用求解各向同性程函方程的快速推进法和Lax-Friedrichs快速扫描算法来分别求解该方程.数值试验表明未加考虑各向异性程函方程与各向同性程函方程的差

  5. Modeling and Strength Analysis of Cylindrical Gears with Curvilinear Shape Teeth for Manufacture%面向制造的弧齿圆柱齿轮建模及强度分析

    Institute of Scientific and Technical Information of China (English)

    王少江; 侯力; 董璐; 肖华军

    2012-01-01

    在分析弧齿圆柱齿轮加工原理和数学建模的基础上,提出一种面向制造的弧齿圆柱齿轮建模新方法,解决长期以来弧齿圆柱齿轮3维造型和实际加工不一致的问题,保证后续分析、加工等工序的正确性。基于UG的二次开发,采用齿坯滚动进给、刀具旋转切削的方法,实现面向制造的弧齿圆柱齿轮的3维造型和快速原型制造,在此基础上深入分析刀具半径对弧齿圆柱齿轮的接触应力分布的影响,得出不同曲率下齿轮强度的变化规律。有限元分析结果表明同等条件下弧齿圆柱齿轮的接触强度较直齿轮有显著提高,其最大齿根应力仅为直齿圆柱齿轮的27%,弧齿圆柱齿轮齿根应力与弧齿线半径有明显的关系。此方法为弧齿圆柱齿轮在高速重载等工况下的工业应用提供理论依据和工程应用价值。%Based on the analysis of generating mechanism and mathematical model for the cylindrical gears with curvilinear shape teeth,a new way of modeling such gears for manufacture was proposed to solve the long existing inconsistencies between three-dimensional modeling and actual processing and to ensure the correctness of follow-up analysis of finite elements and gear machining.Adopting the secondary development of UG and the approach of gear blank's rolling feed and gear cutting tool's rotary,the three-dimensional model of such gears was accordingly built and proved to achieve rapid prototyping manufacture.Then,with the analysis of the model's strength and finite elements performed,it was confirmed that the contact strength of tooth surface of cylindrical gears with curvilinear shape teeth could be substantially improved,compared with that of spur gears,and that the maximal stress equivalent was only twenty-seven percent of spur gears'.Meanwhile,the requirements of high speed and heavy duty gear transmission could be satisfied.Therefore,this approach was a good example of the

  6. Disckectomy, Partial Adjacent Centrum Resection, Bone Graft with Titanium Mesh and Titanium Plate Fixation for the Treatment of Single Segment Cervical Disc Degeneration with Adjacent Vertebral Posterior Osteophyte%椎间盘及部分椎体切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘突出伴椎体后缘骨赘

    Institute of Scientific and Technical Information of China (English)

    孙继飞; 何强; 刘振利; 陈庆胜

    2012-01-01

    目的 评价颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘退变突出伴相邻椎体后缘骨赘的疗效. 方法 应用颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘退变突出伴相邻椎体后缘骨赘22例.取颈椎前路手术切口,术中仅切除突出的椎间盘及相邻椎体的1/3~ 1/2,使脊髓得到彻底的减压.再用填满碎骨的钛网植于骨缺损处加用钛板螺丝钉内固定,固定范围仅限于相邻椎体.术前和术后通过神经功能JOA评分、颈部轴性症状、颈椎动态侧位片和颈椎MRI比较临床疗效. 结果 均获随访,平均15(6 ~24)个月,术后JOA评分优良率86.4%,颈部轴性症状减轻,脊髓功能明显得到恢复.颈椎活动度良好.X线检查见钛网植骨及钛板内固定良好,未见不稳现象.MRI示颈髓压迫解除. 结论 颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘突出伴相邻椎体骨赘效果显著,可最大限度地保留颈椎节段的活动度.%Objective To evaluate the clinical effects of disckectomy, partial adjacent centrum resection , bone graft with titanium mesh and titanium plate fixation for the treatment of single segment cervical disc degeneration with adjacent vertebral posterior osteophyte. Methods There were 22 cases received this kind of surgical procedure. By anterior cervical incision, the herniated disc and only 1/3 to 1/2 of the adjacent vertebral body were removed for the decompression of the spinal cord. Then the titanium mesh filled with the small bones was implanted in the bone defect followed by titanium screw fixation. The fixation was limited to the adjacent vertebral bodies. Preoperative and postoperative neurological functions of the JOA score, the cervical axial symptoms, the cervical dynamic radiographs and cervical spine MRI were used to compare the clinical

  7. Volume Rendering for Curvilinear and Unstructured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Williams, P; Silva, C; Cook, R

    2003-03-05

    We discuss two volume rendering methods developed at Lawrence Livermore National Laboratory. The first, cell projection, renders the polygons in the projection of each cell. It requires a global visibility sort in order to composite the cells in back to front order, and we discuss several different algorithms for this sort. The second method uses regularly spaced slice planes perpendicular to the X, Y, or Z axes, which slice the cells into polygons. Both methods are supplemented with anti-aliasing techniques to deal with small cells that might fall between pixel samples or slice planes, and both have been parallelized.

  8. New method of investigation on 3 D hydrodynamic model in curvilinear coordinates%曲线坐标系下三维水动力模型求解新方法

    Institute of Scientific and Technical Information of China (English)

    吴卫国; 沈露予; 薛世峰

    2014-01-01

    为求解三维水动力模型的高精度数值计算,设计了一种在曲线坐标系下求解的新方法。对ξ,η和ζ共3个方向的空间导数分别采用高精度的紧致有限差分以及非线性项的迎风紧致有限差分格式,时间积分则采用四阶修正Runge-Kutta显式格式。为了验证该算法求解曲线坐标系下三维水动力模型的正确性,选取与De Vriend的180°弯道水槽试验相同的物理参数进行数值试验,计算出水位、流速分布等,并将计算结果与De Vriend的试验值以及先前采用SIMPLEC法获得的数值结果进行了对比分析。结果发现:文中创建的高精度算法获得的数值解比SIMPLEC法计算的数值结果更符合试验值,通过算法定量计算得到的平均速度值与试验测量值之间产生的最大相对误差约为3%。说明构建的高精度紧致有限差分算法来数值求解三维水动力问题是可行的、合理的,为天然河道、明渠以及湖泊等水动力计算提供参考依据。%A numerical method for solving three-dimensional hydrodynamic model in curvilinear coordi-nates was presented.High-order and high-resolution compact finite difference scheme and upwind com-pact finite difference scheme for nonlinear terms were used as spatial discretization,and the time inte-gration was accomplished by 4th-order modified Runge -Kutta scheme.To verify the numerical me-thod,the same physical parameters of De Vriend's 180°curved channel test were used in the simula-tion.The results show that,the new numerical results are closer to the experimental data than the re-sults calculated by using SIMPLEC.The maximum relative error between numerical and experimental average velocity results is less than 3%.It is proved that the numerical method presented is feasible and rational.To sum up,it is an efficient,feasible and rational way to numerically solve hydrodynamic problems,and can be used in many engineering computations of

  9. The Curvilinear Relationship between Perceived Organizational Support, Work Engagement and Its Boundary Conditions%组织支持感与工作投入的曲线关系及其边界条件

    Institute of Scientific and Technical Information of China (English)

    孙健敏; 陆欣欣; 孙嘉卿

    2015-01-01

    As a type of important job resource , perceived organizational support has been identified as a salient antecedent of work engagement .However , the extant literature has ignored that with the norm of reciprocity as its core tenet , perceived organization-al support requires reciprocation from the recipients .Then, below a certain point, employees who perceive organizational support are expected to reciprocate by performing extra-role behavior , which reduces their engagement in assigned work .Based on Job-Demand Resource model and social exchange theory , we argue that there may be U-shaped relationship between perceived organi-zational support and work engagement .Moreover, the extent to which individuals are engaged in extra-role performance is pro-foundly shaped by their affective commitment with the organization .Therefore, we propose that affective commitment moderates the curvilinear relationship between perceived organizational support and work engagement . We collected data among 302 employees with diverse positions in securities industry who self-reported the variables .Confirmatory factor analysis was conducted to detect potential Common Method Bias and the results suggested that CMB was not serious as con -cerned.Theoretical hypotheses were tested using polynomial regression .The results suggested that after controlling for affective commitment, there was U-shaped relationship between perceived organizational support and work engagement , such that only over a certain point perceived organizational support was positively related with work engagement .Moreover , the non-linear relation-ship was moderated by affective commitment .Specifically , for those with high affective commitment , perceived organizational support was related to work engagement in a U-shaped manner , whereas the relationship was linear among those with low affective commitment. Our research shed light on the negative effect of perceived organizational support on work engagement and

  10. Neurons in the pigeon caudolateral nidopallium differentiate Pavlovian conditioned stimuli but not their associated reward value in a sign-tracking paradigm

    Science.gov (United States)

    Kasties, Nils; Starosta, Sarah; Güntürkün, Onur; Stüttgen, Maik C.

    2016-01-01

    Animals exploit visual information to identify objects, form stimulus-reward associations, and prepare appropriate behavioral responses. The nidopallium caudolaterale (NCL), an associative region of the avian endbrain, contains neurons exhibiting prominent response modulation during presentation of reward-predicting visual stimuli, but it is unclear whether neural activity represents valuation signals, stimulus properties, or sensorimotor contingencies. To test the hypothesis that NCL neurons represent stimulus value, we subjected pigeons to a Pavlovian sign-tracking paradigm in which visual cues predicted rewards differing in magnitude (large vs. small) and delay to presentation (short vs. long). Subjects’ strength of conditioned responding to visual cues reliably differentiated between predicted reward types and thus indexed valuation. The majority of NCL neurons discriminated between visual cues, with discriminability peaking shortly after stimulus onset and being maintained at lower levels throughout the stimulus presentation period. However, while some cells’ firing rates correlated with reward value, such neurons were not more frequent than expected by chance. Instead, neurons formed discernible clusters which differed in their preferred visual cue. We propose that this activity pattern constitutes a prerequisite for using visual information in more complex situations e.g. requiring value-based choices. PMID:27762287

  11. Light capsules shaped by curvilinear meta-surfaces

    CERN Document Server

    Naserpour, Mahin; Zakery, A; Miret, Juan J

    2015-01-01

    We propose a simple yet efficient method for generating in-plane hollow beams with a nearly-full circular light shell without the contribution of backward propagating waves. The method relies on modulating the phase in the near field of a centro-symmetric optical wavefront, such as that from a high-numericalaperture focused wave field. We illustrate how beam acceleration may be carried out by using an ultranarrow non-flat meta-surface formed by engineered plasmonic nanoslits. A mirrorsymmetric, with respect to the optical axis, circular caustic surface is numerically demonstrated that can be used as an optical bottle.

  12. Height among Women is Curvilinearly Related to Life History Strategy

    NARCIS (Netherlands)

    Buunk, Abraham P.; Pollet, Thomas V.; Klavina, Liga; Figueredo, Aurelio Jose; Dijkstra, Pieternel

    2009-01-01

    It was hypothesized that women of medium height would show a more secure, long-term mating pattern characterized by less jealousy, less intrasexual competition and a "slower" life history strategy. In three samples of female undergraduate students clear support was found for these hypotheses. In Stu

  13. How a Curvilinear Continental Margin Influences Its Subsidence History

    Science.gov (United States)

    Sacek, V.; Ussami, N.

    2012-12-01

    Current one-dimensional (1D) and two-dimensional (2D) thermo-mechanical models successfully explain the first-order vertical motions of sedimentary basins created by lithospheric extension. However, the modeling of second-order effects such as extra-subsidence, non-monotonic-subsidence or protracted-subsidence still remains controversial. One aspect that has not been fully considered in the current models is that the rifting direction leading to the continental break-up does not always follow a straight line, which demands a three-dimensional (3D) approach. The aim of this work is to demonstrate the importance of using a 3D model that takes into account the curvature of rifting along the margin and theoretically predicts some of the second-order subsidence observations. Our results indicate that concave oceanward margins tend to subside faster than convex ones. This differential subsidence of the margin is a result of the combined effect of lateral thermal conduction, small-scale mantle (or edge driven) convection and the curvature of the rifting. We have used the finite element code CITCOM (Moresi & Gurnis, 1996; Zhong et al., 2000) to construct 3D numerical models of the mantle convection and its effect on the surface evolution. We observed that the differential subsidence along a curved margin is dependent on the viscosity structure of the mantle: for an asthenospheric viscosity of 5×1020 Pa.s the differential subsidence can reach more than 700 m assuming a sediment filled basin; however, for low asthenospheric viscosity (geometry. As an application of this 3D conceptual model for curved margin, we analysed the stratigraphic evolution of the Santos Basin, offshore Southeastern Brazil, and we propose that the variations in the subsidence history along the margin can be explained by its 3D geometry and the dynamical evolution of the mantle. We conclude that the incorporation of the third dimension in the study of the subsidence history of divergent margins may also provide information on the physical properties of the mantle. Keywords: 3D numerical model; Basin subsidence; Continental margin. References: L. Moresi, M. Gurnis, Constraints on the lateral strength of slabs from three-dimensional dynamic flow models, Earth Planet. Sci. Lett. 138 (1996) 15-28. S. Zhong, M.T. Zuber, L. Moresi, M. Gurnis, The role of temperature-dependent viscosity and surface plates in spherical shell models of mantle convection, J. Geophys. Res. 105 (2000) 11063-11082.

  14. Analyzing genotype-by-environment interaction using curvilinear regression

    Directory of Open Access Journals (Sweden)

    Dulce Gamito Santinhos Pereira

    2012-12-01

    Full Text Available In the context of multi-environment trials, where a series of experiments is conducted across different environmental conditions, the analysis of the structure of genotype-by-environment interaction is an important topic. This paper presents a generalization of the joint regression analysis for the cases where the response (e.g. yield is not linear across environments and can be written as a second (or higher order polynomial or another non-linear function. After identifying the common form regression function for all genotypes, we propose a selection procedure based on the adaptation of two tests: (i a test for parallelism of regression curves; and (ii a test of coincidence for those regressions. When the hypothesis of parallelism is rejected, subgroups of genotypes where the responses are parallel (or coincident should be identified. The use of the Scheffé multiple comparison method for regression coefficients in second-order polynomials allows to group the genotypes in two types of groups: one with upward-facing concavity (i.e. potential yield growth, and the other with downward-facing concavity (i.e. the yield approaches saturation. Theoretical results for genotype comparison and genotype selection are illustrated with an example of yield from a non-orthogonal series of experiments with winter rye (Secalecereale L.. We have deleted 10 % of that data at random to show that our meteorology is fully applicable to incomplete data sets, often observed in multi-environment trials.

  15. Association between delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and joint space narrowing and osteophytes

    DEFF Research Database (Denmark)

    Owman, H; Ericsson, Y B; Englund, M;

    2014-01-01

    OBJECTIVE: To examine the association between the relaxation time (T1Gd) of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and grade of tibiofemoral joint space narrowing (JSN) and osteophytosis 11 years later, in a cohort of meniscectomized patients. DESIGN: Patients...

  16. Automated reconstruction of curvilinear fibres from 3D datasets acquired by X-ray microtomography.

    Science.gov (United States)

    Eberhardt, C N; Clarke, A R

    2002-04-01

    The characterization of fibrous structures is important in both composites and textiles research for relating to the bulk properties of the material. However, the microscopic nature of the fibres and their high densities make them very difficult to characterize. Many techniques have been developed for the measurement and characterization of fibrous structures but they tend to be restricted to measurements on the sample surface or within physical cross-sections. X-ray microtomography can be used to non-destructively probe the internal structure of a range of fibrous materials, providing large amounts of 3D data. A technique has been developed for tracing fibres within 3D datasets acquired by X-ray microtomography and this has been applied to a glass fibre reinforced composite and also a non-woven textile sample. The 3D fibrous structures of both samples were successfully reconstructed and their fibre orientation distributions calculated. This technique enables novel characterizations, such as the through-thickness variation of fibre orientation in non-wovens.

  17. Curvilinear wave-equation angle transform: Caustics, turning rays, absence of kinematic artifacts

    NARCIS (Netherlands)

    Stolk, C.C.; De Hoop, M.V.

    2007-01-01

    Migration of seismic reflection data to common image-point gathers is an integral part of both migration velocity analysis (MVA) and amplitude (AVA) analysis. Its applicability in complex geology depends on whether these gathers will be artifact free, and is related to the formation of caustics and

  18. Characterizing Curvilinear Features Using the Localized Normal-Score Ensemble Kalman Filter

    OpenAIRE

    Haiyan Zhou; Liangping Li; J. Jaime Gómez-Hernández

    2012-01-01

    The localized normal-score ensemble Kalman filter is shown to work for the characterization of non-multi-Gaussian distributed hydraulic conductivities by assimilating state observation data. The influence of type of flow regime, number of observation piezometers, and the prior model structure are evaluated in a synthetic aquifer. Steady-state observation data are not sufficient to identify the conductivity channels. Transient-state data are necessary for a good characterization of the hydraul...

  19. A Hybrid PO - Higher-Order Hierarchical MoM Formulation using Curvilinear Geometry Modeling

    DEFF Research Database (Denmark)

    Jørgensen, E.; Meincke, Peter; Breinbjerg, Olav

    2003-01-01

    A very efficient hybrid PO-MoM method has been presented. In contrast to existing methods, the present solution employs higher-order hierarchical basis functions to discretize the MoM and PO currents. This allows to reduce the number of basis functions in both the PO and MoM regions considerably...

  20. Quantifying performance of ultrasonic immersion inspection using phased arrays for curvilinear disc forgings

    Science.gov (United States)

    Brown, Roy H.; Dobson, Jeff; Pierce, S. Gareth; Dutton, Ben; Collison, Ian

    2017-02-01

    Use of full-matrix capture (FMC), combined with the total focusing method (TFM), has been shown to provide improvements to flaw sensitivity within components of irregular geometry. Ultrasonic immersion inspection of aerospace discs requires strict specifications to ensure full coverage - one of which is that all surfaces should be machined flat. The ability to detect defects through curved surfaces, with an equivalent sensitivity to that obtained through flat surfaces could bring many advantages. In this work, the relationship between surface curvature and sensitivity to standard defects was quantified for various front wall radii. Phased array FMC immersion inspection of curved components was simulated using finite element modelling, then visualized using surface-compensated focusing techniques. This includes the use of BRAIN software developed at the University of Bristol for production of TFM images. Modelling results were compared to experimental data from a series of test blocks with a range of curvatures, containing standard defects. The sensitivity to defects is evaluated by comparing the performance to conventional methods. Results are used to highlight the benefits and limitations of these methods relating to the application area of aerospace engine disc forgings.

  1. Large-Area, Freestanding MOF Films of Planar, Curvilinear, or Micropatterned Topographies.

    Science.gov (United States)

    Yoon, Seok Min; Park, Jun Heuk; Grzybowski, Bartosz A

    2017-01-02

    Freestanding MOF films up to six-inches across and replicating various surface (micro)patterns are prepared via a templated growth method. When grown on copper supports, these films have preferred orientation of the constituent crystallites, translating into markedly different wetting properties of the film's two surfaces (water-pinning vs. water repellant). In addition, the films exhibit differential sorption of various organic solvents, can recover oil spills from seawater, and can also act as active layers of chemical sensors.

  2. Thick-walled anisotropic elliptic tube analyzed via curvilinear tensor calculus

    Directory of Open Access Journals (Sweden)

    Mareš T.

    2007-10-01

    Full Text Available After a brief introduction into the tensor calculus, the thick-walled anisotropic elliptic tube is analyzed. A procedure of the analysis is described in a stepwise manner. A choice of the appropriate coordinate systems is the first step. The second step consists of the determination of corresponding metric tensors. Then the elasticity tensor of a local orthotropy is transformed into a global computational coordinate system. Next the appropriate Christoffel symbols of the second kind are determined and the total potential energy of the system is expressed. At the end the solution is approximated by a Fourier series and for given geometrical values and loading the numerical results are obtained and graphically represented.It must be said that throughout the calculation the free software only was used and for the numerical operations an old laptop is sufficient. The author regards both the former and the latter as a great advantage of the demonstrated method.

  3. Modelling the Shallow Water Equations in Curvilinear Coordinates with Physical Application

    Energy Technology Data Exchange (ETDEWEB)

    Wingenter, Suzanne [San Diego State Univ., CA (United States)

    2005-01-12

    The goal of this project is to provide the capability for simulating fluid flow on complicated geometries, such as in the Bahia de Todos Santos. The Bahia de Todos Santos is a bay situated in the northwest corner of Mexico, off the coast of Ensenada and south of San Diego, California, USA. Figure 1.1 shows the Bahia de Todos Santos. It is part of an image taken from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Aqua and Terra satellites in late June and early July 2003 [8]. Roughly 200 square kilometers in size, the bay also contains two islands off the peninsula of Punta Banda. Characteristics of flow in this bay are driven by the moon tide (M2) and wind forcing [9].

  4. Curvilinear Associations between Benefit Finding and Psychosocial Adjustment to Breast Cancer

    Science.gov (United States)

    Lechner, Suzanne C.; Carver, Charles S.; Antoni, Michael H.; Weaver, Kathryn E.; Phillips, Kristin M.

    2006-01-01

    Two previously studied cohorts of women with nonmetastatic breast cancer (Ns = 230 and 136) were reexamined. Participants were assessed during the year after surgery and 5-8 years later. Associations were examined between benefit finding (BF) and several indicators of psychosocial adjustment (e.g., perceived quality of life, positive affect,…

  5. APPLIED PROBLEMS OF CURVILINEAR MOTION DYNAMICS OF ALL-WHEEL DRIVE TRACTION MEANS

    Directory of Open Access Journals (Sweden)

    G. S. Gorin

    2014-01-01

    Full Text Available Fundamental principles for hybrid theory on turning of an all-wheel drive system are given in the paper. The paper shows expediency of accounting longitudinal additional tangential reactions (parasitic forces in contacts of central and lateral wheels with foundation. Algorithms for calculating additional tangential reactions have been proposed in the paper. The paper presents calculation kinematics model for turning of steered and rigid bogie with inter-wheel differential at various axial drive.

  6. Inducible chondrocyte-specific overexpression of BMP2 in young mice results in severe aggravation of osteophyte formation in experimental OA without altering cartilage damage

    NARCIS (Netherlands)

    Davidson, E.N.; Vitters, E.L.; Bennink, M.B.; Lent, P.L. van; Caam, A.P. van; Blom, A.B.; Berg, W.B. van den; Loo, F.A.J. van de; Kraan, P.M. van der

    2015-01-01

    OBJECTIVES: In osteoarthritis (OA) chondrocytes surrounding lesions express elevated bone morphogenetic protein 2 (BMP2) levels. To investigate the functional consequence of chondrocyte-specific BMP2 expression, we made a collagen type II dependent, doxycycline (dox)-inducible BMP2 transgenic mouse

  7. Extensions of the Johnson-Neyman Technique to Linear Models with Curvilinear Effects: Derivations and Analytical Tools

    Science.gov (United States)

    Miller, Jason W.; Stromeyer, William R.; Schwieterman, Matthew A.

    2013-01-01

    The past decade has witnessed renewed interest in the use of the Johnson-Neyman (J-N) technique for calculating the regions of significance for the simple slope of a focal predictor on an outcome variable across the range of a second, continuous independent variable. Although tools have been developed to apply this technique to probe 2- and 3-way…

  8. Simulation of 2-D Compressible Flows on a Moving Curvilinear Mesh with an Implicit-Explicit Runge-Kutta Method

    KAUST Repository

    AbuAlSaud, Moataz

    2012-07-01

    The purpose of this thesis is to solve unsteady two-dimensional compressible Navier-Stokes equations for a moving mesh using implicit explicit (IMEX) Runge- Kutta scheme. The moving mesh is implemented in the equations using Arbitrary Lagrangian Eulerian (ALE) formulation. The inviscid part of the equation is explicitly solved using second-order Godunov method, whereas the viscous part is calculated implicitly. We simulate subsonic compressible flow over static NACA-0012 airfoil at different angle of attacks. Finally, the moving mesh is examined via oscillating the airfoil between angle of attack = 0 and = 20 harmonically. It is observed that the numerical solution matches the experimental and numerical results in the literature to within 20%.

  9. When Are Workload and Workplace Learning Opportunities Related in a Curvilinear Manner? The Moderating Role of Autonomy

    Science.gov (United States)

    van Ruysseveldt, Joris; van Dijke, Marius

    2011-01-01

    Building on theoretical frameworks like the Job Demands Control model and Action Theory we tested whether the relationship between workload and employees' experiences of opportunities for workplace learning is of an inverted u-shaped nature and whether autonomy moderates this relationship. We predicted that--at moderate levels of…

  10. Curvilinear VO(2):power output relationship in a ramp test in professional cyclists: possible association with blood hemoglobin concentration.

    Science.gov (United States)

    Lucía, Alejandro; Hoyos, Jesús; Santalla, Alfredo; Pérez, Margarita; Chicharro, José L

    2002-02-01

    The purpose of this study was to determine (1) if there exists an additional, nonlinear increase (DeltaVO(2)) in the oxygen uptake observed (VO2 (obs)) at the maximal power output reached during a ramp cycle ergometer test and that expected (VO2 (exp)) from the linear relationship between VO(2) and power output below the lactate threshold (LT) in professional riders, and (2) the relationship between DeltaVO(2) and possible explanatory mechanisms. Each of 12 professional cyclists (25 +/- 1 years; VO(2 max): 71.3 +/- 1.2 ml x kg(-1) x min(-1)) performed a ramp test until exhaustion (power output increases of 25 W x min(-1)) during which several gas-exchange and blood variables were measured (including lactate, HCO(3)(-) and K(+)). VO(2) was linearly related to power output until the LT in all subjects. Afterward, a nonlinear deflection was observed in the VO(2):power output relationship (DeltaVO(2) = 2492 +/- 55 ml x min(-1) and p < 0.05 for VO2 (obs) vs. VO2 (exp)). A significant negative correlation was encountered between DeltaVO(2) and resting hemoglobin levels before the tests (r = 20.61; p < 0.05). In conclusion, professional cyclists exhibit an attenuation of the VO(2) rise above the LT.

  11. A speed of sound aberration correction algorithm for curvilinear ultrasound transducers in ultrasound-based image-guided radiotherapy

    Science.gov (United States)

    Fontanarosa, Davide; Pesente, Silvia; Pascoli, Francesco; Ermacora, Denis; Abu Rumeileh, Imad; Verhaegen, Frank

    2013-03-01

    Conventional ultrasound (US) devices use the time of flight (TOF) of reflected US pulses to calculate distances inside the scanned tissues and thus create images. The speed of sound (SOS) is assumed to be constant in all human soft tissues at a generally accepted average value of 1540 m s-1. This assumption is a source of systematic errors up to several millimeters and of image distortion in quantitative US imaging. In this work, an extension of a method recently published by Fontanarosa et al (2011 Med. Phys. 38 2665-73) is presented: the aim is to correct SOS aberrations in three-dimensional (3D) US images in those cases where a spatially co-registered computerized tomography (CT) scan is also available; the algorithm is then applicable to a more general case where the lines of view (LOV) of the US device are not necessarily parallel and coplanar, thus allowing correction also for US transducers other than linear. The algorithm was applied on a multi-modality pelvic US phantom, scanned through three different liquid layers on top of the phantom with different SOS values; the results show that the correction restores a better match between the CT and the US images, reducing the differences to sub-millimeter agreement. Fifteen clinical cases of prostate cancer patients were also investigated: the SOS corrections of prostate centroids were on average +3.1 mm (max + 4.9 mm-min + 1.3 mm). This is in excellent agreement with reports in the literature on differences between measured prostate positions by US and other techniques, where often the discrepancy was attributed to other causes.

  12. Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows.

    Science.gov (United States)

    Yatou, Hiroki

    2010-09-01

    We numerically find three types of steady solutions of viscoelastic flows and flow pattern transitions between them in a two-dimensional wavy-walled channel for low to moderate Weissenberg (Wi) and Reynolds (Re) numbers using a spectral element method. The solutions are called "convective," "transition," and "elastic" in ascending order of Wi. In the convective region in the Wi-Re parameter space, convective effect and pressure gradient balance on average. As Wi increases, elastic effect becomes comparable, and the first transition sets in. Through the transition, a separation vortex disappears, and a jet flow induced close to the wall by the viscoelasticity moves into the bulk; the viscous drag significantly drops, and the elastic wall friction rises sharply. This transition is caused by an elastic force in the streamwise direction due to the competition of the convective and elastic effects. In the transition region, the convective and elastic effects balance. When the elastic effect becomes greater than the convective effect, the second transition occurs but it is relatively moderate. The second transition seems to be governed by the so-called Weissenberg effect. These transitions are not sensitive to driving forces. By a scaling analysis, it is shown that the stress component is proportional to the Reynolds number on the boundary of the first transition in the Wi-Re space. This scaling coincides well with the numerical result.

  13. Fairness perceptions as a moderator in the curvilinear relationships between job demands, and job performance and job satisfaction

    NARCIS (Netherlands)

    Janssen, O

    2001-01-01

    Activation theory suggests that intermediate rather than low or high levels of quantitative job demands benefit job performance and job satisfaction among managers. Using an equity theory framework, I hypothesize that perceptions of effort-reward fairness moderate these inverted U-shaped demand-resp

  14. Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows

    CERN Document Server

    Yatou, Hiroki

    2010-01-01

    We find three types of steady solutions and remarkable flow pattern transitions between them in a two-dimensional wavy-walled channel for low to moderate Reynolds (Re) and Weissenberg (Wi) numbers using direct numerical simulations with spectral element method. The solutions are called "convective", "transition", and "elastic" in ascending order of Wi. In the convective region in the Re-Wi parameter space, the convective effect and the pressure gradient balance on average. As Wi increases, the elastic effect becomes suddenly comparable and the first transition sets in. Through the transition, a separation vortex disappears and a jet flow induced close to the wall by the viscoelasticity moves into the bulk; The viscous drag significantly drops and the elastic wall friction rises sharply. This transition is caused by an elastic force in the streamwise direction due to the competition of the convective and elastic effects. In the transition region, the convective and elastic effects balance. When the elastic eff...

  15. When are workload and workplace learning opportunities related in a curvilinear manner? The moderating role of autonomy

    NARCIS (Netherlands)

    J. van Ruysseveldt (Joris); M.H. van Dijke (Marius)

    2011-01-01

    textabstractBuilding on theoretical frameworks like the Job Demands Control model and Action Theory we tested whether the relationship between workload and employees’ experiences of opportunities for workplace learning is of an inverted u-shaped nature and whether autonomy moderates this relationshi

  16. Flow pattern transition accompanied with sudden growth of flow resistance in two-dimensional curvilinear viscoelastic flows

    OpenAIRE

    Yatou, Hiroki

    2010-01-01

    We find three types of steady solutions and remarkable flow pattern transitions between them in a two-dimensional wavy-walled channel for low to moderate Reynolds (Re) and Weissenberg (Wi) numbers using direct numerical simulations with spectral element method. The solutions are called "convective", "transition", and "elastic" in ascending order of Wi. In the convective region in the Re-Wi parameter space, the convective effect and the pressure gradient balance on average. As Wi increases, th...

  17. Cascading and Parallelising Curvilinear Inertial Focusing Systems for High Volume, Wide Size Distribution, Separation and Concentration of Particles

    Science.gov (United States)

    Miller, B.; Jimenez, M.; Bridle, H.

    2016-11-01

    Inertial focusing is a microfluidic based separation and concentration technology that has expanded rapidly in the last few years. Throughput is high compared to other microfluidic approaches although sample volumes have typically remained in the millilitre range. Here we present a strategy for achieving rapid high volume processing with stacked and cascaded inertial focusing systems, allowing for separation and concentration of particles with a large size range, demonstrated here from 30 μm-300 μm. The system is based on curved channels, in a novel toroidal configuration and a stack of 20 devices has been shown to operate at 1 L/min. Recirculation allows for efficient removal of large particles whereas a cascading strategy enables sequential removal of particles down to a final stage where the target particle size can be concentrated. The demonstration of curved stacked channels operating in a cascaded manner allows for high throughput applications, potentially replacing filtration in applications such as environmental monitoring, industrial cleaning processes, biomedical and bioprocessing and many more.

  18. Completion rates of anterior and posterior continuous curvilinear capsulorrhexis in pediatric cataract surgery for surgery performed by trainee surgeons with the use of a low-cost viscoelastic

    Directory of Open Access Journals (Sweden)

    R Muralidhar

    2012-01-01

    Full Text Available Context : Pediatric cataract surgery is traditionally done with the aid of high-molecular-weight viscoelastics which are expensive. It needs to be determined if low-cost substitutes are just as successful. Aims : The study aims to determine the success rates for anterior and posterior capsulorrhexis and intraocular lens (IOL implantation in the bag for pediatric cataract surgery performed with the aid of a low-molecular-weight viscoelastic. Settings and Design : Nonrandomized observational study. Materials and Methods: Children less than 6 years of age who underwent cataract surgery with IOL implantation in the period May 2008-May 2009 were included. The surgeries were done by pediatric ophthalmology fellows. A standard procedure of anterior capsulorrhexis, lens aspiration with primary posterior capsulorrhexis, anterior vitrectomy, and IOL implantation was followed. Three parameters were studied: successful completion of anterior and posterior capsulorrhexis and IOL implantation in the bag. Results: 33 eyes of 28 children were studied. The success rate for completion was 66.7% and 88.2 % for anterior and posterior capsulorrhexis, respectively. IOL implantation in the bag was successful in 87.9%. Conclusions: 2% hydroxypropylmethylcellulose is a viable low-cost alternative to more expensive options similar to high-molecular-weight viscoelastics. This is of great relevance to hospitals in developing countries.

  19. New Physical Optics Method for Curvilinear Refractive Surfaces and its Verification in the Design and Testing of W-band Dual-Aspheric Lenses

    Science.gov (United States)

    2013-10-01

    aspheric ( plano -convex) and (b) optimized dual- aspheric W-band PTFE lenses as needed for a non-paraxial system of Fig. 1 . . 10 3 Profiles of (a) full...is comparable with the given lens diameter Dc = 140mm. Following conventional solutions, non-paraxial lenses of plano -convex type are usually em...optimized by applying more advanced methods, e.g., full-wave approaches, etc. When considering plano -convex lenses by ray-tracing methods, we arrive at

  20. A three-dimensional solid-liquid two-phase turbulence model with the effect of vegetation in non-orthogonal curvilinear coordinates

    Institute of Scientific and Technical Information of China (English)

    LIU Cheng; SHEN YongMing

    2009-01-01

    A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation Is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.

  1. A three-dimensional solid-liquid two-phase turbulence model with the effect of vegetation in non-orthogonal curvilinear coordinates

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A three-dimensional k-ε-Ap solid-liquid two-phase two-fluid model with the effect of vegetation is solved numerically with a finite-volume method on an adaptive grid to study water-sediment movements and bed evolution in vegetated channels. The additional drag force and additional turbulence generation due to vegetation are added to the relevant control equations for simulating the interaction between vegetation and flow. The flow structure and the bed-topography changes in a 60° partly vegetated channel bend are calculated by the model. The numerical results agree well with the measured ones. Calculated and measured results show that the primary flow velocity reduces much in the vegetation zone and increases in the non-vegetation zone, the secondary flow velocity weakens in the vegetation zone and strengthens in the non-vegetation zone, the sediment movement and bed-topography change also weaken in the vegetation zone and strengthen in the non-vegetation zone, a well-planed vegetation arrangement can improve bank stabilization program, and the k-ε-Ap model can deal with bed-load transport with a more reasonable method than the one-fluid model.

  2. Energy functional derivative with respect to the length of a curvilinear oblique cut in the equilibrium problem for a Timoshenko plate

    Science.gov (United States)

    Lazarev, N. P.

    2015-11-01

    This paper describes the dependence of the solution of the equilibrium problem for a Timoshenko plate and the total energy functional of the plate on the perturbation of an oblique crack. The nonlinearity of the problem is caused by the boundary conditions in the form of inequalities (conditions such as the Signorini conditions), which describe mutual nonpenetration of the opposite crack faces. The continuous dependence of the solution of the problem on the perturbation of the crack length is established. A formula for the energy functional derivative of the perturbation of the crack length is obtained.

  3. Radiographic Study of Bony Changes of the Mandibular Condyle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung A; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, School of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    2000-03-15

    The purpose of this study is to compare radiographic techniques for the diagnostic accuracy in the detection of osteophytes of the mandibular condyle. A series of bone chips were placed at four locations on the condylar head of a dried human skull. Eight radiographic techniques such as panoramic, transcranial, infracranial, transorbital, reverse-Towne's, submentovertex, multidirectional tomographic and computed tomographic techniques were compared. Three oral radiologists were asked to rate the lesions by four stage score. The statistical analysis was performed by ANOVA test. For the detection of lateral osteophyte, transcranial, infracranial, transorbital and reverse-Towne's views showed superiority. Also, transcranial and infracranial views showed superiority for medial osteophyte. While for the detection of superior and anterior osteophyte, panoramic, transcranial, infracranial, transorbital views showed superiority. Lateral tomograph showed superiority for the detection of superior and anterior osteophyte, but it showed inferiority for lateral and medial osteophte. And antero-posterior tomograph showed superiority for the detection of all osteophytes. Axial computed tomograph showed superiority for the detection of all osteophytes, and coronal computed tomograph showed superiority for lateral, medial and superior osteophytes. While reconstructed sagittal computed tomograph showed relatively superiority for the detection of anterior and superior osteophytes. The conventional radiographs can be used for the detection of bony changes of the mandibular condyle, and tomograph or computed tomograph can be used additionally when it is difficult to detect bony changes on conventional radiographs.

  4. The new way for mandibular hypoplasia: Curvilinear distraction osteogenesis%治疗下颌骨发育不良的新方法-曲线牵张成骨

    Institute of Scientific and Technical Information of China (English)

    许美邦

    2011-01-01

    @@ 下颌骨发育不良是最常见的颅颌面畸形之一,需要手术、口腔正畸等跨学科联合治疗.有些患者因先天畸形需要延长发育不良的下颌骨长度来改善外观和功能,而牵张成骨已成为广泛接受的手术治疗方法.

  5. Numerical Grid Generation. Proceedings of a Symposium on the Numerical Generation of Curvilinear Coordinate Systems and their Use in the Numerical Solution of Partial Differential Equations, held April 1982, Nashville, Tennessee

    Science.gov (United States)

    1982-04-01

    has a unique solution when V’ satisfies a Lipschitz condition. 30’ tWOW! * * 215 ! To obtain a comparison with direct Cartesian formulations, we will...U: V *3 ~ 224 Haussling and Coleman [251 presented a method that was based entirely on the condition g12 , 0. Because of the above nonuniqueness , the...insure that the difference molecule had a nonzero central coefficient. Unlike the nonunique situation above, the available degree of freedom to impose an

  6. The application of posterior continuous curvilinear capsularhexis in congenital cataract surgery of infant%后囊环形撕囊在幼儿先天性白内障术中的应用

    Institute of Scientific and Technical Information of China (English)

    石莹琳; 张亚平

    2005-01-01

    目的探讨在幼儿先天性白内障手术中行一期后囊连续环形撕囊的临床意义.方法对18例(30眼)幼儿先天性白内障采用一期后囊环形撕囊.结果术后术眼均达到视轴区透明.结论一期后囊环形撕囊可有效地预防幼儿先天性白内障术后后发障的发生.

  7. Identifying biological pathways in the MRI findings of people with low back pain

    DEFF Research Database (Denmark)

    Jensen, Rikke Krüger; Jensen, Tue Secher; Kjær, Per;

    on intervertebral disc height and signal intensity, disc protrusions, high intensity zones, size and type of vertebral endplate signal changes, vertebral endplate irregularities and defects, osteophytes, and spondylolisthesis. Latent class analysis (probabilistic data mining) was used to distinguish the best...

  8. Impaled aorta: a rare case of aortic perforation with a vertebral outgrowth.

    Science.gov (United States)

    Afifi, Rana O; Sandhu, Harleen K; Fraser, Charles D; Estrera, Anthony L

    2015-04-01

    We describe an unusual case of aortic perforation by a vertebral osteophyte, complicated by a mycotic pseudoaneurysm, in a patient who underwent successful repair. To our knowledge, no similar case has been reported previously.

  9. Matrix Gla Protein polymorphism, but not concentrations, is associated with radiographic hand osteoarthritis

    Science.gov (United States)

    Objective. Factors associated with mineralization and osteophyte formation in osteoarthritis (OA) are incompletely understood. Genetic polymorphisms of matrix Gla protein (MGP), a mineralization inhibitor, have been associated clinically with conditions of abnormal calcification. We therefore evalua...

  10. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

    OpenAIRE

    Ezgi Akar; Mehmet Ufuk Akmil; Merih İş

    2015-01-01

    Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF) in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males) who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of inter...

  11. Type IV Collagen Controls the Axogenesis of Cerebellar Granule Cells by Regulating Basement Membrane Integrity in Zebrafish.

    Science.gov (United States)

    Takeuchi, Miki; Yamaguchi, Shingo; Yonemura, Shigenobu; Kakiguchi, Kisa; Sato, Yoshikatsu; Higashiyama, Tetsuya; Shimizu, Takashi; Hibi, Masahiko

    2015-10-01

    Granule cells (GCs) are the major glutamatergic neurons in the cerebellum, and GC axon formation is an initial step in establishing functional cerebellar circuits. In the zebrafish cerebellum, GCs can be classified into rostromedial and caudolateral groups, according to the locations of their somata in the corresponding cerebellar lobes. The axons of the GCs in the caudolateral lobes terminate on crest cells in the dorsal hindbrain, as well as forming en passant synapses with Purkinje cells in the cerebellum. In the zebrafish mutant shiomaneki, the caudolateral GCs extend aberrant axons. Positional cloning revealed that the shiomaneki (sio) gene locus encodes Col4a6, a subunit of type IV collagen, which, in a complex with Col4a5, is a basement membrane (BM) component. Both col4a5 and col4a6 mutants displayed similar abnormalities in the axogenesis of GCs and retinal ganglion cells (RGCs). Although type IV collagen is reported to control axon targeting by regulating the concentration gradient of an axonal guidance molecule Slit, Slit overexpression did not affect the GC axons. The structure of the BM surrounding the tectum and dorsal hindbrain was disorganized in the col4a5 and col4a6 mutants. Moreover, the abnormal axogenesis of the caudolateral GCs and the RGCs was coupled with aberrant BM structures in the type IV collagen mutants. The regrowth of GC axons after experimental ablation revealed that the original and newly formed axons displayed similar branching and extension abnormalities in the col4a6 mutants. These results collectively suggest that type IV collagen controls GC axon formation by regulating the integrity of the BM, which provides axons with the correct path to their targets.

  12. Type IV Collagen Controls the Axogenesis of Cerebellar Granule Cells by Regulating Basement Membrane Integrity in Zebrafish.

    Directory of Open Access Journals (Sweden)

    Miki Takeuchi

    2015-10-01

    Full Text Available Granule cells (GCs are the major glutamatergic neurons in the cerebellum, and GC axon formation is an initial step in establishing functional cerebellar circuits. In the zebrafish cerebellum, GCs can be classified into rostromedial and caudolateral groups, according to the locations of their somata in the corresponding cerebellar lobes. The axons of the GCs in the caudolateral lobes terminate on crest cells in the dorsal hindbrain, as well as forming en passant synapses with Purkinje cells in the cerebellum. In the zebrafish mutant shiomaneki, the caudolateral GCs extend aberrant axons. Positional cloning revealed that the shiomaneki (sio gene locus encodes Col4a6, a subunit of type IV collagen, which, in a complex with Col4a5, is a basement membrane (BM component. Both col4a5 and col4a6 mutants displayed similar abnormalities in the axogenesis of GCs and retinal ganglion cells (RGCs. Although type IV collagen is reported to control axon targeting by regulating the concentration gradient of an axonal guidance molecule Slit, Slit overexpression did not affect the GC axons. The structure of the BM surrounding the tectum and dorsal hindbrain was disorganized in the col4a5 and col4a6 mutants. Moreover, the abnormal axogenesis of the caudolateral GCs and the RGCs was coupled with aberrant BM structures in the type IV collagen mutants. The regrowth of GC axons after experimental ablation revealed that the original and newly formed axons displayed similar branching and extension abnormalities in the col4a6 mutants. These results collectively suggest that type IV collagen controls GC axon formation by regulating the integrity of the BM, which provides axons with the correct path to their targets.

  13. Dynamic equations for curved submerged floating tunnel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In virtue of reference Cartesian coordinates, geometrical relations of spatial curved structure are presented in orthogonal curvilinear coordinates. Dynamic equations for helical girder are derived by Hamilton principle. These equations indicate that four generalized displacements are coupled with each other. When spatial structure degenerates into planar curvilinear structure, two generalized displacements in two perpendicular planes are coupled with each other. Dynamic equations for arbitrary curvilinear structure may be obtained by the method used in this paper.

  14. Radiographic analysis of factors predisposing toward tendon tears in the knee extensor mechanism

    Directory of Open Access Journals (Sweden)

    Rodrigo Pires e Albuquerque

    2014-08-01

    Full Text Available Objectives:To review radiographs of patients who suffered tendon tears of the knee extensor apparatus and observe alterations that might be factors predisposing toward this type of injury.Methods:We retrospectively analyzed 60 cases of injury to the knee extensor mechanism that were treated surgically at the Miguel Couto Municipal Hospital between March 2004 and March 2011. Four patients were excluded due to poor quality of the examination.Results:Of the 56 patients evaluated, 23 were considered to be normal and 33 presented radiographic alterations. Among these, eight (24.3% presented suprapatellar osteophytes alone; seven (21.2%, infrapatellar calcification; seven (21.2%, suprapatellar calcification; six (18.2%, supra- and infrapatellar osteophytes; and five (15.1%, infrapatellar osteophytes alone.Conclusion:Radiographic alterations were frequently observed in patients with extensor mechanism tears.

  15. The Curvilinear Relation between Job Insecurity and Voice Behavior: Moderating Effect of Self-efficacy%基于自我效能感调节作用的工作不安全感对建言行为的影响研究

    Institute of Scientific and Technical Information of China (English)

    周浩; 龙立荣

    2013-01-01

    基于对286名员工及其直接上级的调查,分析了工作不安全感对建言行为的影响以及自我效能感的调节作用.研究表明,工作不安全感对建言行为存在倒U形的影响;员工的自我效能感对建言行为具有积极的影响,并对工作不安全感与建言行为之间的关系具有调节作用.最后,分析了研究的理论贡献、管理启示以及未来的研究方向.

  16. Dynamic ASE Modeling and Optimization of Aircraft with SpaRibs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose development and demonstration of a dynamic aeroservoelastic modeling and optimization system based on curvilinear internal structural arrangements of...

  17. The diagnostic performance of radiography for detection of osteoarthritis-associated features compared with MRI in hip joints with chronic pain

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Li [Boston University School of Medicine, Quantitative Imaging Center, Department of Radiology, Boston, MA (United States); Beijing Jishuitan Hospital, Department of Radiology, Beijing (China); Hayashi, Daichi; Guermazi, Ali [Boston University School of Medicine, Quantitative Imaging Center, Department of Radiology, Boston, MA (United States); Hunter, David J. [University of Sydney, Department of Medicine, Sydney (Australia); Li, Ling [New England Baptist Hospital, Division of Research, Boston, MA (United States); Winterstein, Anton; Bohndorf, Klaus [Klinikum Augsburg, Department of Radiology, Augsburg (Germany); Roemer, Frank W. [Boston University School of Medicine, Quantitative Imaging Center, Department of Radiology, Boston, MA (United States); Klinikum Augsburg, Department of Radiology, Augsburg (Germany); University of Erlangen, Department of Radiology, Erlangen (Germany)

    2013-10-15

    To evaluate the diagnostic performance of radiography for the detection of MRI-detected osteoarthritis-associated features in various articular subregions of the hip joint. Forty-four patients with chronic hip pain (mean age, 63.3 {+-} 9.5 years), who were part of the Hip Osteoarthritis MRI Scoring (HOAMS) cohort, underwent both weight-bearing anteroposterior pelvic radiography and 1.5 T MRI. The HOAMS study was a prospective observational study involving 52 subjects, conducted to develop a semiquantitative MRI scoring system for hip osteoarthritis features. In the present study, eight subjects were excluded because of a lack of radiographic assessment. On radiography, the presence of superior and medial joint space narrowing, superior and inferior acetabular/femoral osteophytes, acetabular subchondral cysts, and bone attrition of femoral head was noted. On MRI, cartilage, osteophytes, subchondral cysts, and bone attrition were evaluated in the corresponding locations. Diagnostic performance of radiography was compared with that of MRI, and the area under curve (AUC) was calculated for each pathological feature. Compared with MRI, radiography provided high specificity (0.76-0.90) but variable sensitivity (0.44-0.78) for diffuse cartilage damage (using JSN as an indirect marker), femoral osteophytes, acetabular subchondral cysts and bone attrition of the femoral head, and a low specificity (0.42 and 0.58) for acetabular osteophytes. The AUC of radiography for detecting overall diffuse cartilage damage, marginal osteophytes, subchondral cysts and bone attrition was 0.76, 0.78, 0.67, and 0.82, respectively. Diagnostic performance of radiography is good for bone attrition, fair for marginal osteophytes and cartilage damage, but poor for subchondral cysts. (orig.)

  18. How much are radiological parameters related to clinical symptoms and function in osteoarthritis of the shoulder?

    Science.gov (United States)

    Kircher, Jörn; Morhard, Markus; Magosch, Petra; Ebinger, Nina; Lichtenberg, Sven; Habermeyer, Peter

    2010-06-01

    Loss of joint space, formation of osteophytes and deformation are common features of osteoarthritis. Little information exists about the radiological features of arthrosis in relation to clinical findings and the radiological appearance in degenerative shoulder joint disease especially with regard to decision making about the timing of joint replacement. We retrospectively examined 120 standardised X-rays of patients with advanced osteoarthritis of the shoulder. Exclusion criteria included rotator cuff tear, severe glenoid erosion or protrusion. Measurements of joint space width at three levels in each plane (anteroposterior and axillary view), humeral head diameter and size of humeral osteophytes were made by two independent examiners. Osteoarthritis was graded according to Samilson and Prieto. Seventy-five of these patients had a complete record from the clinical investigation (pain record on VAS scale, active and passive range of motion) and the constant score (CS). Mean joint space width in the central anteroposterior level was 1.46 mm +/- 1.08 and in the central axillary 0.98 mm +/- 1.02. Increasing age was positively correlated with joint space narrowing at all measured levels. The joint space width was not correlated with the Samilson grade or the size of osteophytes. The joint space width was neither correlated with pain nor active or passive ROM. Pain was correlated with active and passive flexion and abduction but not for internal or external rotation. The size of the osteophytes was negatively correlated (active and passive) with flexion, abduction and external and internal rotation. The study illustrates that joint space narrowing and development of osteophytes are reliable but independent parameters of primary shoulder arthrosis and should be recorded separately. The size of the caudal humeral osteophyte is a predictive factor for function and should be taken into account for clinical decision making. The primary clinical feature, pain, as the main

  19. Osteoarthritis and bone: Osteologic types of osteoarthritis of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Oettmeier, R.; Abendroth, K.

    1989-05-01

    To assess prognosis and indications for allografting articular surfaces, osteological examination is of increasing importance. In this study 93 femoral heads of patients with primary osteoarthritis could be differentiated into three osteologic types using histomorphometry: (1) the osteosclerotic type (77% of cases), (2) the hyperostotic type, with excessive neogenesis of bone all over the femoral head and increased formation of osteophytes (10% of cases), and (3) the osteopenic type, with decreased bone mass and features of bone remodelling, a greater occurrence of subchondral cysts, and small osteophytes (8% of cases). Radiological and clinical features to distinguish these groups are given. The consequences for pathogenesis and clinical practice are discussed. (orig.).

  20. Reward and adversity processing circuits, their competition and interactions with dopamine and serotonin signaling

    OpenAIRE

    Vadovičová, Karin; Gasparotti, Roberto

    2013-01-01

    We propose that dACC, AI and caudolateral OFC(clOFC) project to lateral habenula (LHb) and D2 loop of ventral striatum (VS), forming a functional adversity processing circuit, directed towards inhibitory avoidance and self-control. This circuit learns what is bad or harmful to us and predicts risks, to stop us from going/moving for bad or suboptimal choices that decrease our well-being and survival chances. Proposed dACC role is to generate a WARNING signal when things are going (or might end...

  1. General Geometry PIC for MIMD Computers

    Science.gov (United States)

    1993-06-01

    34* transfinite interpolation subdivision of the curvilinear quadrilateral multi- blocks into quadrilateral elements, "* indirect ("glue patch") addressing...9 regular (i.j./k) cubic lattice addressing within blocks. * transfinite interpolation subdivision of curvilinear hexahedral blocky. into finite...combination of isoparametric hezahedral elements, generated by transfinite interpolation, and multiblock decomposition leads to algorithms ideally suited to

  2. New Equating Methods and Their Relationships with Levine Observed Score Linear Equating under the Kernel Equating Framework

    Science.gov (United States)

    Chen, Haiwen; Holland, Paul

    2010-01-01

    In this paper, we develop a new curvilinear equating for the nonequivalent groups with anchor test (NEAT) design under the assumption of the classical test theory model, that we name curvilinear Levine observed score equating. In fact, by applying both the kernel equating framework and the mean preserving linear transformation of…

  3. Impact Injury Caused by Linear Acceleration: Mechanisms, Prevention and Cost

    Science.gov (United States)

    1982-04-29

    corresponded to the fractured side of the pelvis resulting in secondary osteoarthrosis of the right coxofemoral joint. Grossly, the spines from the...articular facet osteoarthrosis . Epstein (2) l suggests that "spondylosis" refers to a pathological condition arising from discal degeneration resulting...thoracolumbar transregion, the secondary margination of anterolateral osteophytes, the secondary osteoarthrosis of articular facets and the presence of

  4. Alarmin S100A9 Induces Proinflammatory and Catabolic Effects Predominantly in the M1 Macrophages of Human Osteoarthritic Synovium

    NARCIS (Netherlands)

    Bosch, M.H.J. van den; Blom, A.B.; Schelbergen, R.F.; Koenders, M.I.; Loo, F.A.J. van de; Berg, W.B. van den; Vogl, T.; Roth, J.; Kraan, P.M. van der; Lent, P.L.E.M. van

    2016-01-01

    OBJECTIVE: The alarmins S100A8 and S100A9 have been shown to regulate synovial activation, cartilage damage, and osteophyte formation in osteoarthritis (OA). Here we investigated the effect of S100A9 on the production of proinflammatory cytokines and matrix metalloprotease (MMP) in OA synovium, gran

  5. Structure-symptom relationship with wide-area ultrasound scanning of knee osteoarthritis

    Science.gov (United States)

    Podlipská, Jana; Koski, Juhani M.; Kaukinen, Päivi; Haapea, Marianne; Tervonen, Osmo; Arokoski, Jari P.; Saarakkala, Simo

    2017-01-01

    The aetiology of knee pain in osteoarthritis (OA) is heterogeneous and its relationship with structural changes and function is unclear. Our goal was to determine the prevalence of wide-area scanned ultrasound-defined knee OA structural features and their association with pain and functional impairment in 79 symptomatic and 63 asymptomatic subjects. All subjects underwent ultrasound knee wide-area scanning and the severity of articular cartilage degeneration, the presence and size of osteophytes, and meniscal extrusion were evaluated. Subjects filled in a self-administrated questionnaire on present knee pain, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) on clinical symptoms and function over the past week. Cartilage changes were the most prevalent followed by lateral meniscal extrusion, osteophytes and medial meniscal extrusion. The global femoral cartilage grade associated strongly with pain and the WOMAC index. Site-specifically, early medial cartilage changes and thinning in sulcus and lateral site were associated with symptoms. The presence of femoral lateral osteophytes was also associated with both outcomes. Using the novel wide-area ultrasound scanning technique, we were able to confirm the negative impact of femoral cartilage OA changes on clinical symptoms. Presence, not necessarily size, of lateral femoral osteophytes was also associated with increased pain and disability. PMID:28295049

  6. Anterior cervical fusion versus minimally invasive posterior keyhole decompression for cervical radiculopathy

    Directory of Open Access Journals (Sweden)

    Richard M. Young

    2015-12-01

    Conclusion: ACDF has been demonstrated to be an effective surgical procedure in treating degenerative spine disease in patients with radiculopathy and/or myelopathy. However, in a population with isolated radiculopathy and radiological imaging confirming an anterolateral disc or osteophyte complex, the MIPKF can provide similar results without the associated risks that accompany an anterior cervical spine fusion.

  7. Structural joint changes, malalignment, and laxity in osteoarthritis of the knee

    NARCIS (Netherlands)

    Esch, van der M.; Steultjens, M.P.; Wieringa, H.; Dinant, H.; Dekker, J.

    2005-01-01

    OBJECTIVE: To assess the relationship between (i) structural joint changes (i.e. joint space narrowing and osteophyte formation) and laxity and (ii) joint malalignment and laxity in osteoarthritis (OA) of the knee. METHODS: A cross-sectional study was carried out on 35 outpatients with osteoarthriti

  8. Agreement in the Interpretation of Magnetic Resonance Images of the Lumbar Spine

    DEFF Research Database (Denmark)

    Kovacs, F M; Royuela, A; Jensen, Tue Secher;

    2009-01-01

    of the previous results. Data on the existence of disc degeneration, high-intensity zones, disc contour, Schmorl nodes, Modic changes, osteophytes, spondylolisthesis, and spinal stenosis were collected in the Nordic Modic Consensus Group Classification form. Intra- and interobserver agreement was analyzed...

  9. Novel genetic variants associated with lumbar disc degeneration in northern Europeans: A meta-analysis of 4600 subjects

    NARCIS (Netherlands)

    F.M.K. Williams (Frances); A.T. Bansal (Aruna); J.B.J. van Meurs (Joyce); J.T. Bell (Jordana); I. Meulenbelt (Ingrid); P. Suri (Pradeep); F. Rivadeneira Ramirez (Fernando); P.N. Sambrook (Philip); A. Hofman (Albert); S.M. Bierma-Zeinstra (Sita); C. Menni (Cristina); M. Kloppenburg (Margreet); P.E. Slagboom (Eline); D. Hunter (David); A.J. MacGregor (Alex ); A.G. Uitterlinden (André); T.D. Spector (Timothy)

    2013-01-01

    textabstractObjective: Lumbar disc degeneration (LDD) is an important cause of low back pain, which is a common and costly problem. LDD is characterised by disc space narrowing and osteophyte growth at the circumference of the disc. To date, the agnostic search of the genome by genome-wide associati

  10. Hip Osteoarthritis: Genetics, epidemiological risk factors and burden of the disease

    NARCIS (Netherlands)

    M.C. Castaño Betancourt (Martha)

    2015-01-01

    markdownabstract__Abstract__ Osteoarthritis (OA) is the most common degenerative joint disease, characterized by progressive damage of the articular cartilage, osteophyte formation and alterations in the subchondral bone. OA is associated with an extremely high burden in terms of health and economi

  11. Digital Mucous Cyst: A Clinical-Surgical Study

    Science.gov (United States)

    Kim, Eun Jung; Huh, Joon Won

    2017-01-01

    Background It has been suggested digital mucous cysts (DMCs) are associated with osteoarthritis and osteophytes in the elderly, and usually have a communicating pedicle with the joint. Surgical excision is a standard therapy with a high cure rate. Objective The purpose of this prospective study is to evaluate the features of DMCs via clinical, radiological and pathological examination and the efficacy of surgical excision of DMCs. Methods Between 2010 and 2014, 24 Korean patients were treated with the resection of the cyst and the pedicle. Preoperative X-ray and ultrasonography were performed to detect the presence of the osteophyte and the connection to the joint space. Postoperative patients' satisfaction score was assessed by the visual analogue scale (0~10). Results The osteophytes were found in 15.8%. In ultrasonographic findings, there were prominent flow signals between the cyst and the joint space in 13.6%. There were no serious postoperative complications, and recurrences were observed in 16.7%. Mean postoperative satisfaction score was 8.3. Conclusion It seems that preoperative X-ray for osteophytes and ultrasonographic study for connection are not always helpful for the treatment of DMCs, and that the surgical excision with a pedicle ligation and electrocoagulation is an effective treatment modality. PMID:28223749

  12. Topography of thalamic projections requires attractive and repulsive functions of Netrin-1 in the ventral telencephalon.

    Directory of Open Access Journals (Sweden)

    Ashton W Powell

    2008-05-01

    Full Text Available Recent studies have demonstrated that the topography of thalamocortical (TC axon projections is initiated before they reach the cortex, in the ventral telencephalon (VTel. However, at this point, the molecular mechanisms patterning the topography of TC projections in the VTel remains poorly understood. Here, we show that a long-range, high-rostral to low-caudal gradient of Netrin-1 in the VTel is required in vivo for the topographic sorting of TC axons to distinct cortical domains. We demonstrate that Netrin-1 is a chemoattractant for rostral thalamic axons but functions as a chemorepulsive cue for caudal thalamic axons. In accordance with this model, DCC is expressed in a high-rostromedial to low-caudolateral gradient in the dorsal thalamus (DTh, whereas three Unc5 receptors (Unc5A-C show graded expression in the reverse orientation. Finally, we show that DCC is required for the attraction of rostromedial thalamic axons to the Netrin-1-rich, anterior part of the VTel, whereas DCC and Unc5A/C receptors are required for the repulsion of caudolateral TC axons from the same Netrin-1-rich region of the VTel. Our results demonstrate that a long-range gradient of Netrin-1 acts as a counteracting force from ephrin-A5 to control the topography of TC projections before they enter the cortex.

  13. Impact of degenerative radiographic abnormalities and vertebral fractures on spinal bone density of women with osteoporosis

    Directory of Open Access Journals (Sweden)

    Lúcia Costa Paiva

    2002-01-01

    Full Text Available CONTEXT: Measurements of bone density taken by dual-energy x-ray absorptiometry are the most accurate procedure for the diagnosis of osteoporosis. This procedure has the disadvantage of measuring the density of all mineral components, including osteophytes, vascular and extra vertebral calcifications. These alterations can influence bone density results and densitometry interpretation. OBJECTIVE: To correlate radiography and densitometry findings from women with osteoporosis, analyzing the influence of degenerative processes and vertebral fractures on the evaluation of bone density. DESIGN: Retrospective study. SETTING: Osteoporosis outpatients' clinic at Hospital das Clínicas, Universidade Estadual de Campinas. PARTICIPANTS: Ninety-six postmenopausal women presenting osteoporosis diagnosed by bone density. MAIN MEASUREMENTS: Bone mineral density of the lumbar spine and femoral neck were measured by the technique of dual-energy x-ray absorptiometry, using a LUNAR-DPX densitometer. Fractures, osteophytes and aortic calcifications were evaluated by simple x-rays of the thoracic and lumbar spine. RESULTS: The x-rays confirmed vertebral fractures in 41.6%, osteophytes in 33.3% and calcifications of the aorta in 30.2%. The prevalence of fractures and aortic calcifications increased with age. The mean bone mineral density was 0.783g/cm² and the mean T-score was --3.47 DP. Neither fractures nor aortic calcifications had significant influence on bone mineral density (P = 0.36 and P = 0.09, respectively, despite the fractured vertebrae having greater bone mineral density (P < 0.02. Patients with lumbar spine osteophytes showed greater bone mineral density (P = 0.04. Osteophytosis was associated with lumbar spine bone mineral density after adjustment for fractures and aortic calcifications by multiple regression (P = 0.01. CONCLUSION: Osteophytes and lumbar spine fractures can overestimate bone density interpretation. The interpretation of densitometry

  14. Prevalence of knee abnormalities in patients with osteoarthritis and anterior cruciate ligament injury identified with peripheral magnetic resonance imaging: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada)]. E-mail: wuh5@mcmaster.ca; Webber, C. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Radiology, Hamilton, Ontario (Canada); Fuentes, C.O. [Hamilton Health Sciences, Dept. of Radiology, Hamilton, Ontario (Canada); Benson, R.; Beattie, K. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada); Adachi, J.D.; Xie, X. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada); Jabbari, F. [Hamilton Health Sciences, Hamilton, Ontario (Canada); Levy, D.R. [McMaster Univ., Sports Medicine, Dept. of Family Medicine and Dept. of Medicine, Hamilton, Ontario (Canada)

    2007-06-15

    To assess, with a peripheral magnetic resonance imaging system (pMRI), the prevalence of bony and soft tissue abnormalities in the knee joints of normal subjects, osteoarthritis (OA) patients, and individuals who have suffered an anterior cruciate ligament (ACL) rupture; and 2) to compare the prevalence among groups. Magnetic resonance (MR) images of 28 healthy, 32 OA, and 26 ACL damaged knees were acquired with a 1.0-T pMRI system. Two radiologists grade the presence and severity of 9 MR image features: cartilage degeneration, osteophytes, subchondral cyst, bone marrow edema, meniscal abnormality, ligament integrity, loose bodies, popliteal cysts, and joint effusion. Ten of 28 healthy (35.7%), 24 of 26 ACL (92.3%), and all OA knees (100%) showed prevalent cartilage defects; 5 healthy (17.9%), 20 ACL (76.9%), and all OA knees (100%) had osteophytes; and 9 normal (32.1%), 21 ACL (80.8%), and 29 OA knees (90.6%) had meniscal abnormalities. One-half of the knees in the OA group (16 of 32, 50%) had subchondral cysts, and almost one-half had bone marrow edema (15 of 32, 46.9%). These features were not common in the ACL group (7.7%, and 11.5%, respectively) and were not observed in healthy knees. The OA group had the most severe cartilage defects, osteophytes, bone marrow edema, subchondral cysts, and meniscal abnormalities; the ACL group showed more severe cartilage defects, osteophytes, and meniscal abnormalities than did normal subjects. The results suggest that knees that have sustained ACL damage have OA-like features, most subjects (19 of 26, 73.1%) could be identified as in the early stage of OA. The prominent abnormalities present in ACL-damaged knees are cartilage defects, osteophytes, and meniscal abnormalities. (author)

  15. Sampling microcanonical ensembles of trajectories using harmonic approximation in internal coordinates.

    Science.gov (United States)

    Rybkin, Vladimir V; Ekström, Ulf

    2014-08-14

    In this paper, we modify quasiclassical harmonic sampling of microcanonical ensembles of trajectories by using the curvilinear internal coordinates. The harmonic approximation in the curvilinear normal coordinates provides a more realistic description of the PES than in the conventional rectilinear ones at finite displacements. Therefore, the sampling of vibrations in the internal coordinates significantly improves the quality of the sampling in a block-box fashion, providing more realistic displacements and reducing the errors in the potential energy. In particular, the sampling of large-amplitude torsion vibrations, which is non-realistic in the Cartesian modes, becomes accurate or acceptable in the curvilinear modes.

  16. MRI of the osteophytosis in experimental osteorthritis of the knee; MRT der Osteophytose bei experimentellen Gonarthrosen

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.C.A. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Adam, G. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Buehne, M. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik; Prescher, A. [RWTH Aachen (Germany). Inst. fuer Anatomie, Lehrstuhl I; Scherer, K. [RWTH Aachen (Germany). Inst. fuer Versuchstierkunde; Kuepper, W. [RWTH Aachen (Germany). Inst. fuer Versuchstierkunde; Guenther, R.W. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    1995-11-01

    The value of MRI for the detection of knee osteophytosis was determined in an animal osteoarthritis model. 10 dogs with experimentally induced unilateral osteoarthritis of the knee were investigated with MRI including 2-D-spin echo (SE) and 3-D-gradient echo (GE) imaging. The results were correlated with gross and histopathologic findings and with radiography. Osteophyte formation appeared early in the osteoarthritic process. Pathological analysis yielded 65 osteophytes. With 3-D-GE imaging. 91% of the osteophytes were detected, while 68% were visible on 2-D-SE images. With two-level radiography, 43% of the osteophytes were diagnosed. Additional use of tunnel view and conventional tomography increased the detection rate to 65%. Independent of the imaging technique, MRI revealed three different signal patterns of the osteophyte bone structure. Compared with the histologically evident fat marrow content and the grade of bone sclerosis, best agreement was achieved with 2-D-SE sequences. However, a discrepancy remained in 22%. A fibrocartilaginous layer at the osteophyte surface could be delineated especially on 3-D-GE images. (orig./MG) [Deutsch] Die Wertigkeit der MRT zur Diagnostik der Osteophytose bei Gonarthrosen wurde anhand eines Tiermodells ueberprueft. 10 Hundekniegelenke mit experimentell induzierter Arthrose wurden MR-tomographisch mit 2-D-Spin-echo(SE)- und 3-D-Gradienten-Echo(GE)-Sequenzen untersucht. Die Ergebnisse wurden mit dem makro- und histopathologischen Befund sowie mit der Roentgendiagnostik korreliert. Osteophyten traten bereits fruehzeitig im arthrotischen Krankheitsprozess auf. Die pathologische Auswertung ergab 65 Osteophyten. Hiervon wurden in 3-D-GE-Sequenzen 91% nachgewiesen, gegenueber 68% in 2-D-SE-Sequenzen. Die Nachweisrate betrug bei Roentgenaufnahmen in zwei Ebenen 43%, wobei die zusaetzliche Beruecksichtigung von Tunnelprojekten und konventioneller Tomographie einen Anstieg auf 65% zur Folge hatte. MR-tomographisch liessen sich

  17. Capsulorhexis contraction after cataract surgery

    DEFF Research Database (Denmark)

    Corydon, Charlotte; Lindholt, Michael; Knudsen, Ellen B

    2007-01-01

    PURPOSE: To evaluate the reduction in the anterior capsule opening after phacoemulsification, continuous curvilinear capsulorhexis, and implantation of 1 of 2 acrylic intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Vejle Hospital, Vejle, Denmark. METHODS: Eighty-four patients (84...

  18. Calcified congenital aneurysm of the left sinus of Valsalva associated with coarctation of the aorta

    Energy Technology Data Exchange (ETDEWEB)

    Paige, M.L.; Schwartz, D.C.

    1983-05-01

    A case of calcified unruptured congenital aneurysm of the left sinus of Valsalva associated with coarctation of the aorta is presented. Routine chest radiographs demonstrated unusual curvilinear calcifications at the cardiac base which were subsequently demonstrated within the aneurysm.

  19. National Income and Income Inequality, Family Affluence and Life Satisfaction Among 13 year Old Boys and Girls

    DEFF Research Database (Denmark)

    Levin, Kate Ann; Torsheim, Torbjorn; Vollebergh, Wilma

    2011-01-01

    . National income and income inequality were associated with aggregated life satisfaction score and prevalence of high life satisfaction. Within-country socioeconomic inequalities in life satisfaction existed even after adjustment for family structure. This relationship was curvilinear and varied cross...

  20. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  1. The Use of Linear Programming for Prediction.

    Science.gov (United States)

    Schnittjer, Carl J.

    The purpose of the study was to develop a linear programming model to be used for prediction, test the accuracy of the predictions, and compare the accuracy with that produced by curvilinear multiple regression analysis. (Author)

  2. Some shell formulations, in view of their applicability to finite elements

    OpenAIRE

    Debongnie, Jean-François

    1986-01-01

    Surface geometry and shell geometry, in the frame of general tensor calculus. Fundamentals of the theory of thin shells. Expressing strains from curvilinear components of the displacements. Applicability of the preceeding theory to finite elements. Expressing strains from the cartesian components of the displacements. Moderate rotation theory (curvilinear components). Moderate rotation theory (cartesian components). Quasi-plane and almost-plane shells. Shells with shearing strains (cartesian ...

  3. Assessment of femur and tibia subchondral parts mineral bone density in gonarthrosis

    Directory of Open Access Journals (Sweden)

    E M Zaitseva

    2005-01-01

    Full Text Available Objective. To assess association between bone mineral density (BMD of parts of femur and tibia gonarthrosis stage. Material and methods. 53 female with bilateral gonarthrosis aged 42 to 84 years with body mass index from 21,2 to 43 kg/m2 were included. Knee joints X-ray examination, densitometry of lumbar spine, femoral neck and condyles of femur and tibia were performed. Subchondral BMD assessment was done in 5 regions of knee. Results. Increase of gonarthrosis stage was accompanied by rise of subchondral tibia BMD values. Increase of medial femur condyles BMD was associated with knee joint space decrease, presence of subchondral osteosclerosis and marginal osteophytes so as knee varus deformity. Subchondral femur BMD values correlated only with the presence of marginal osteophytes.

  4. Cervical spine annulus vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, S.P.; Chen, Y.M.

    1988-07-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  5. Cervical spine annulus vacuum.

    Science.gov (United States)

    Bohrer, S P; Chen, Y M

    1988-01-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  6. [Dysphagia: Forestier and Rotes Querol disease].

    Science.gov (United States)

    Cruz-Ruiz, M A; López-Saúz, M; Padierna-Luna, J L; García-Pescador, D; Franco-Grande, M A; Núñez-Sánchez, A

    2008-01-01

    Inside of the study of Dysphagia, until 38% of the greater patients of 50 years, they present/display cervical Osteophytes like cause of Dysphagia; frequently I diagnose passes for the methods of radiology and endoscopy unnoticed. The disease of Forestier and Rotes better well known Querol or like skeletal hiperostosis diffuse idiophatic it is characterized by the formation of spinal and cervical Osteophytes, ossification of ligaments and muscles for vetebrates of the cervical column. Frequently it produces affectation to medullar that it can pronounce like Dysphagia and crosstalk. We presented/displayed the case of a patient of 78 years with chronic pneumopathy, that presents/displays Dysphagia and progressive crosstalk with pondered loss, in where radiology of the cervical column they show cervical osteofitos with espondilolistesis, rectification of the cervical lordosis and diminution of the intersomatic spaces that they compress the trachea and column of air and an extrinsic compression below the cricopharyngeal is documented by endoscopy.

  7. Description of immature stages of Culex ocossa Dyar & Knab, Culex delpontei Duret and Culex pereyrai Duret of the Melanoconion subgenus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Maria Anice Mureb Sallum

    2001-10-01

    Full Text Available The larva and pupa of Culex (Melanoconion ocossa Dyar & Knab are redescribed and those of Culex (Melanoconion delpontei Duret and Culex (Melanoconion pereyrai Duret are described from specimens collected in the states of São Paulo and Paraná, Brazil. The pupa of Cx. ocossa differs from those of the other two species in having seta 5-IV-VI dark with strongly aciculated branches, and caudolateral angle of segment VIII produced into sharp point, and seta 1-P present; Cx. delpontei can be distinguished from Cx. pereyrai in possessing paddle lightly tanned, trumpet flared, and wing and leg cases lightly tanned, without pattern of dark spots; Cx. pereyrai can be recognized by having wing case with pattern of dark, discontinuously pigmented, longitudinal lines, and trumpet cylindrical, not flared. The larvae of the three species share the presence of seta 2-C placed medially to seta 1-C.

  8. The Neural Basis of Long-Distance Navigation in Birds.

    Science.gov (United States)

    Mouritsen, Henrik; Heyers, Dominik; Güntürkün, Onur

    2016-01-01

    Migratory birds can navigate over tens of thousands of kilometers with an accuracy unobtainable for human navigators. To do so, they use their brains. In this review, we address how birds sense navigation- and orientation-relevant cues and where in their brains each individual cue is processed. When little is currently known, we make educated predictions as to which brain regions could be involved. We ask where and how multisensory navigational information is integrated and suggest that the hippocampus could interact with structures that represent maps and compass information to compute and constantly control navigational goals and directions. We also suggest that the caudolateral nidopallium could be involved in weighing conflicting pieces of information against each other, making decisions, and helping the animal respond to unexpected situations. Considering the gaps in current knowledge, some of our suggestions may be wrong. However, our main aim is to stimulate further research in this fascinating field.

  9. A Note on Natural Coordinates and Frenet Frames

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiaozhou; ZHU Keqin

    2007-01-01

    This paper discusses the relationship between natural coordinates in fluid mechanics and orthogonal curvilinear coordinates. Since orthogonal curvilinear coordinates have some excellent mathematical properties, natural coordinates can be applied more widely if they can be transformed to orthogonal curvilinear coordinates. Frenet formulas which describe the differential properties of natural coordinates were compared with the derivative formulas of orthogonal curvilinear coordinates to show that natural coordinates are not generally orthogonal curvilinear coordinates. A method was introduced to transform natural coordinates into orthogonal curvilinear coordinates by rotating the normal planes of the natural coordinates about the streamlines. The transformation is true as long as the natural coordinates satisfy several equations. Vorticity decomposition in the natural coordinates is used to show that these conditional equations are satisfied only if the streamlines are perpendicular to the vortexlines on every given point in the flow field. These equations apply in both planar flows and axisymmetric flows without a circumferential velocity component, but do not apply in some 3-D flows such as Beltrami flow.

  10. Articular Exposure with the Swashbuckler versus a Mini-Swashbuckler Approach

    Science.gov (United States)

    2012-01-01

    cadaveric specimen was collected to include: age, gender, height, weight, and body mass index (BMI). We defined osteoarthrosis as the presence of...osteophytes and complete cartilage eburnation with exposed subchondral bone. Severe osteoarthrosis existed if the changes were so severe as to alter the bony...right and left limbs with respect to age, gender, height, weight, BMI, or presence of osteoarthrosis . Out of the 20 limbs, 9 (45%) had evidence of

  11. Functional Fitness and Self-Reported Quality of Life of Older Women Diagnosed with Knee Osteoarthrosis: A Cross-Sectional Case Control Study

    OpenAIRE

    Paula Andréa Malveira Cavalcante; Márcio Roberto Doro; Frank Shiguemitsu Suzuki; Roberta Luksevicius Rica; Andrey Jorge Serra; Francisco Luciano Pontes Junior; Alexandre Lopes Evangelista; Aylton José Figueira Junior; Julien Steven Baker; Danilo Sales Bocalini

    2015-01-01

    Aim. Utilizing a cross-sectional case control design, the aim of this study was to evaluate the functional fitness and self-reported quality of life differences in older people diagnosed with knee osteoarthrosis (O) who participated in health promotion groups. Methods. Ninety older women were distributed into two groups: control without O of the knee (C, n = 40) and a group diagnosed with primary and secondary knee O with grade II or higher, with definite osteophytes (OA, n = 50). Functional ...

  12. Locking of metacarpophalangeal joints in a patient with acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Y.; Tanaka, N.; Isoya, Eiji [Dept. of Orthopaedic Surgery, Soseikai General Hospital, Kyoto (Japan)

    1999-11-01

    A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking. (orig.)

  13. Appendicular bone mass and knee and hand osteoarthritis in Japanese women: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Moji Kazuhiko

    2002-10-01

    Full Text Available Abstract Background It has been reported that there is an inverse association between osteoarthritis (OA and osteoporosis. However, the relationship of bone mass to OA in a Japanese population whose rates of OA are different from Caucasians remains uncertain. Methods We studied the association of appendicular bone mineral density (second metacarpal; mBMD and quantitative bone ultrasound (calcaneus; stiffness index with knee and hand OA among 567 Japanese community-dwelling women. Knee and hand radiographs were scored for OA using Kellgren-Lawrence (K/L scales. In addition, we evaluated the presence of osteophytes and of joint space narrowing. The hand joints were examined at the distal and proximal interphalangeal (DIP, PIP and first metacarpophalangeal/carpometacarpal (MCP/CMC joints. Results After adjusting for age and body mass index (BMI, stiffness index was significantly higher in women with K/L scale, grade 3 at CMC/MCP joint compared with those with no OA. Adjusted means of stiffness index and mBMD were significantly higher in women with definite osteophytes at the CMC/MCP joint compared to those without osteophytes, whereas there were no significant differences for knee, DIP and PIP joints. Stiffness index, but not mBMD, was higher in women with definite joint space narrowing at the CMC/MCP joint compared with those with no joint space narrowing. Conclusions Appendicular bone mass was increased with OA at the CMC/MCP joint, especially among women with osteophytes. Our findings suggest that the association of peripheral bone mass with OA for knee, DIP or PIP may be less clearcut in Japanese women than in other populations.

  14. Upper cervical spinal cord compression due to bony stenosis of the spinal canal.

    Science.gov (United States)

    Benitah, S; Raftopoulos, C; Balériaux, D; Levivier, M; Dedeire, S

    1994-04-01

    Compression of the upper cervical spinal cord due to stenosis of the bony spinal canal is infrequent. In the first case reported here, stenosis was due to acquired extensive, unilateral osteophytes centered on the left apophyseal joints of C1-C2 in an elderly professional violinist. In the second case, stenosis was secondary to isolated congenital hypertrophy of the laminae of C1 and C2.

  15. A diagnostic and therapeutic challenge involving a case of dysphagia in association with cervical osteophytosis and a dental pain

    OpenAIRE

    Dable, Rajani A; Wasnik, Pradnya B.; Sunilkumar L Nagmode; Mukkaram Faridi Ali

    2013-01-01

    Herein, presenting a case of a 42-year-old female with the chief complaint of dysphagia. The problem was assumed to be of dental origin, due to the onset of dental pain followed by dysphagia. A cervical radiograph revealed the presence of osteophytic lipping which proved to be the cause of dysphagia. Confusing and overlapping disease entities showing similar symptoms need thorough investigation. Dysphagia related to cervical spondylosis may have a direct connection with the person′s occupatio...

  16. Early x-ray diagnosis of coxarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lingg, G.; Nebel, G.

    Radiological and pathological comparisons on specimen of femur head and neck at autopsy have shown a statistical relationship between osteophytosis of the femoral head and ulcerations of the joint cartilage. Especially, there are highly significant relationships between the length of osteophytes and the diameter of the ulcera. The 'plaque'-sign is shown to be a very sensitive indicator of early arthrosis. So there exist semiquantitative parameters for the X-ray diagnosis of early coxarthrosis.

  17. Osteoarthritic changes and condylar positioning of the temporomandibular joint in Korean children and adolescents

    OpenAIRE

    Cho, Bong-Hae; Jung, Yun-Hoa

    2012-01-01

    Purpose To investigate the prevalence of osteoarthritic changes and condylar positioning of the temporomandibular joint (TMJ) in Korean children and adolescents with or without temporomandibular disorders (TMDs). Materials and Methods A total of 101 asymptomatic and 181 symptomatic children and adolescents aged 10 to 18 years old were included in the study. Osteoarthritic changes such as flattening, sclerosis, osteophytes, or erosion, and the parasagittal positioning of the condyle were asses...

  18. Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS)

    DEFF Research Database (Denmark)

    Roemer, Frank W; Frobell, Richard; Lohmander, Stefan

    2014-01-01

    OBJECTIVE: To develop a whole joint scoring system, the Anterior Cruciate Ligament OsteoArthritis Score (ACLOAS), for magnetic resonance imaging (MRI)-based assessment of acute anterior cruciate ligament (ACL) injury and follow-up of structural sequelae, and to assess its reliability. DESIGN...... and longitudinal changes including osteoarthritis (OA) features. Joint features assessed were acute osteochondral injury, traumatic and degenerative bone marrow lesions (BMLs), meniscus morphology and extrusion, osteophytes, collateral and cruciate ligaments including ACL graft, Hoffa-synovitis and effusion...

  19. Vertebral Fractures and Spondylosis in Men - Original Investigation

    Directory of Open Access Journals (Sweden)

    Selmin Gülbahar

    2008-04-01

    Full Text Available Aim: The aim of this study was to investigate the relationship between vertebral fractures and spondylosis and bone mineral density in men older than 60 years. Material and Method: Thirty-two men with back and low back pain aged over 60 years were included into the study. Thoracic and lumbar spine radiographs were taken and, anterior, central and posterior heights of each vertebral body from T4 to L5 was measured and than the number of vertebral fractures was assessed. Osteophyte and disc scores were used for evaluation of spondylosis. Bone mineral density was measured by dual-energy-X-ray absorptiometry. Measurements were obtained from lumbar vertebrae and proximal femoral region. Results: Significant positive correlations were found between vertebral fracture and osteophyte score and bone mineral density of total femoral region. When osteophyte score and total femoral bone mineral density were taken into consideration, there were no significant correlations between other parameters and vertebral fracture. Significant positive correlations were observed between osteophyte score and bone mineral density and t scores of L1-4. Also there were significant positive correlations between disc score and both bone mineral density and t scores of L1-4. Significant positive correlation was also found between femoral bone density and body weight. Conclusion: Finally, lumbar bone mineral density increases with spinal degenerative changes, but the increase in bone mineral density can not prevent sub clinic vertebral fractures. Especially, in the men who have intensive spinal degenerative changes, the measurement of lumbar bone mineral density is not enough for determining the fracture risk. Measurement of femoral bone mineral density and evaluation of clinic risk factors are more important for determining the fracture risk. (From the World of Osteoporosis 2008;14:1-6

  20. Changes in brain activity related to eating chocolate: from pleasure to aversion.

    Science.gov (United States)

    Small, D M; Zatorre, R J; Dagher, A; Evans, A C; Jones-Gotman, M

    2001-09-01

    We performed successive H(2)(15)O-PET scans on volunteers as they ate chocolate to beyond satiety. Thus, the sensory stimulus and act (eating) were held constant while the reward value of the chocolate and motivation of the subject to eat were manipulated by feeding. Non-specific effects of satiety (such as feelings of fullness and autonomic changes) were also present and probably contributed to the modulation of brain activity. After eating each piece of chocolate, subjects gave ratings of how pleasant/unpleasant the chocolate was and of how much they did or did not want another piece of chocolate. Regional cerebral blood flow was then regressed against subjects' ratings. Different groups of structures were recruited selectively depending on whether subjects were eating chocolate when they were highly motivated to eat and rated the chocolate as very pleasant [subcallosal region, caudomedial orbitofrontal cortex (OFC), insula/operculum, striatum and midbrain] or whether they ate chocolate despite being satiated (parahippocampal gyrus, caudolateral OFC and prefrontal regions). As predicted, modulation was observed in cortical chemosensory areas, including the insula and caudomedial and caudolateral OFC, suggesting that the reward value of food is represented here. Of particular interest, the medial and lateral caudal OFC showed opposite patterns of activity. This pattern of activity indicates that there may be a functional segregation of the neural representation of reward and punishment within this region. The only brain region that was active during both positive and negative compared with neutral conditions was the posterior cingulate cortex. Therefore, these results support the hypothesis that there are two separate motivational systems: one orchestrating approach and another avoidance behaviours.

  1. Fat-Free Body Mass but not Fat Mass is Associated with Reduced Gray Matter Volume of Cortical Brain Regions Implicated in Autonomic and Homeostatic Regulation

    Science.gov (United States)

    Weise, Christopher M; Thiyyagura, Pradeep; Reiman, Eric M; Chen, Kewei; Krakoff, Jonathan

    2014-01-01

    Obesity has been associated with alterations of both functional and structural aspects of the human central nervous system. In obese individuals both fat mass (FM; primarily consisting of adipose tissue) and fat-free mass (FFM; all non-adipose tissues) are increased and it remains unknown whether these compartments have separate effects on human brain morphology. We used voxel-based morphometry to investigate the relationships between measures of body composition and regional gray matter volume (GMV) in 76 healthy adults with a wide range of adiposity (24F/52M; age 32.1±8.8y; percentage of body fat [PFAT%] 25.5±10.9%; BMI 29.8±8.9). Faf-free mass index (FFMI kg*m-2) showed negative associations in bilateral temporal regions, the bilateral medial and caudolateral OFC, and the left insula. Fat mass index (FMI kg*m-2) showed similar, but less extensive negative associations within temporal cortical regions and the left caudolateral orbitofrontal cortex (OFC). In addition, negative associations were seen for FMI with GMV of the cerebellum. Associations of FFMI with temporal and medial orbitofrontal GMV appeared to be independent of adiposity. No associations were seen between measures of adiposity (i.e. FM and PFAT) and GMV when adjusted for FFM. The majority of regions that we find associated with FFM have been implicated in the regulation of eating behavior and show extensive projections to central autonomic and homeostatic core structures. These data indicate that not adipose tissue or relative adiposity itself, but obesity related increases in absolute tissue mass and particularly FFM may have a more predominant effect on the human brain. This might be explained by the high metabolic demand of FFM and related increases in total energy needs. PMID:22974975

  2. Sensitivity of radiographic features and specificity of scintigraphic imaging in hand osteoarthritis; Sensibilite des signes radiographiques et specificite de la scintigraphie dans l`arthrose de la main

    Energy Technology Data Exchange (ETDEWEB)

    Buckland-Wright, J.C.; MacFarlane, D.G.; Lynch, J.A. [Guy`s and St. Thomas`s Hospitals, London (United Kingdom)

    1995-06-01

    We undertook to determine which of the radiographic features most reliably detected the presence and disease progression in osteoarthritis in the hand; and which of the radiographic features corresponded with the radionuclide bone scan images. 32 patients with osteoarthritis had X5 macroradiographs taken of their wrists and hands at 6 monthly intervals over an 18 month period. The high magnification and resolution of microfocal radiography permitted quantitative detection of the extent and change in joint space width, subchondral sclerosis, osteophytosis and juxtaarticular radiolucencies. 4-hour technetium 99{sup m} methylene bisphophonate bone scans were taken at 0 and 12 months and the activity of the tracer uptake at each joint scored. The latter was compared with the radiographic features at each visit and the changes between visits analysed. In hand OA the most sensitive radiographic parameters for detecting disease were osteophytes, subchondral sclerosis and justaarticular radiolucencies, with radionuclide imaging demonstrating the increased activity in bone formation associated with the growth and remodelling of osteophytes. Changes in the number and size of osteophytes and joint space narrowing were the only reliable and sensitive parameters for assessing disease progression. We conclude that in osteoarthritis, the bony changes progress significantly before the occurrence of radiographically evident joint space narrowing indicative of cartilage thinning. (authors). 48 refs., 2 tabs., 11 figs.

  3. Evaluation of the correlation between disc displacements and degenerative bone changes of the temporomandibular joint by means of magnetic resonance images.

    Science.gov (United States)

    Dias, Isabela Maddalena; Coelho, Patrícia Rocha; Picorelli Assis, Neuza Maria Souza; Pereira Leite, Fabiola Pessôa; Devito, Karina Lopes

    2012-09-01

    The aim was to evaluate the correlation between disc displacements and degenerative bone changes in magnetic resonance images (MRI) of 112 patients of both genders, with signs and symptoms of temporomandibular disorder. For this purpose, a calibrated examiner evaluated 224 MRI by assigning scores for the displacement of the disc and degenerative bone changes. Disc displacement was found in 58.42% of the temporomandibular joints (TMJs) evaluated. Anterior displacement of the disc with reduction was the most common, occurring in 67.18% cases of joints with disc displacement. Degenerative bone changes were observed in 53.94% of the TMJs analysed. There was significant correlation between disc displacement with reduction and condylar flattening, disc displacement without reduction and condylar flattening, disc displacement without reduction, and associated degenerative bone changes (flattening and erosion, flattening, osteophyte and erosion; flattening and osteophytes, erosion and sclerosis, flattening and sclerosis, flattening, osteophytes and sclerosis). The correlation between advanced cases of disc displacement and the occurrence of degenerative bone changes emphasises the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan and in cases in which clinical examination is not sufficient for these purposes.

  4. MR abnormalities of the intervertebral disks and adjacent bone marrow as predictors of segmental instability of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Braem, J.; Zanetti, M.; Hodler, J. [Orthopedic University Clinic Balgrist, Zurich (Switzerland). Dept. of Diagnostic Radiology; Min, K. [Orthopedic University Clinic Balgrist, Zurich (Switzerland). Dept. of Orthopedic Surgery

    1998-01-01

    Purpose: To assess whether MR abnormalities of the intervertebral disks and adjacent bone marrow can predict segmental instability of the lumbar spine as diagnosed on functional radiographs. Material and Methods: A consecutive review was made of 60 patients examined with MR imaging and with lateral flexion and extension views of the lumbar spine. Sagittal T1- and T2-weighted images were evaluated blindly with regard to abnormalities of the intervertebral disk and the adjacent bone marrow. Segmental instability was diagnosed when a.p. translation of 3 mm or more was present on the functional radiographs. Moreover, the presence of osteophytes was evaluated on lateral standard radiographs. Results: Of a total of 300 segments, 32 (10.7%) were unstable. Anular tears were the most relevant MR finding. Their sensitivity, specificity, and positive and negative predictive values for segmental instability were 18.8%, 97.0%, 42.9% and 90.9%. The corresponding values for traction osteophytes were 12.5%, 98.1%, 44.4% and 90.4%. Abnormalities of bone marrow were not significantly related to segmental instability (p=0.35). Conclusion: Functional radiographs should be considered in patients with anular tears or traction osteophytes. No correlation was found between segmental instability and abnormalities of bone marrow adjacent to the endplates. (orig.).

  5. Childhood interparental conflict and HPA axis activity in young adulthood: examining nonlinear relations.

    Science.gov (United States)

    Hagan, Melissa J; Roubinov, Danielle S; Purdom Marreiro, Catherine L; Luecken, Linda J

    2014-05-01

    Relations between early adversity and the neuroendocrine stress response are most often tested in a linear framework. Findings from studies of nonlinear relations between early stress and reactivity in childhood are suggestive, but curvilinear associations between childhood family stress and stress reactivity at later developmental stages remain unexplored. The current study examined curvilinear relations between childhood interparental conflict (IPC) and cortisol reactivity in young adulthood. Participants (n = 91; Mean age = 18.7, SD = .97; 59% White, 25% Hispanic) reported on the frequency and intensity of childhood exposure to IPC and salivary cortisol was sampled before and after a challenging interpersonal role-play task. Significant curvilinear relations were found such that higher total cortisol and cortisol reactivity during the task was observed among youth reporting lower and higher frequency of IPC, suggesting that moderate IPC exposure may be associated with lower cortisol activity at a later developmental stage.

  6. Rapid directional change degrades GPS distance measurement validity during intermittent intensity running.

    Directory of Open Access Journals (Sweden)

    Jonathan C Rawstorn

    Full Text Available Use of the Global Positioning System (GPS for quantifying athletic performance is common in many team sports. The effect of running velocity on measurement validity is well established, but the influence of rapid directional change is not well understood in team sport applications. This effect was systematically evaluated using multidirectional and curvilinear adaptations of a validated soccer simulation protocol that maintained identical velocity profiles. Team sport athletes completed 90 min trials of the Loughborough Intermittent Shuttle-running Test movement pattern on curvilinear, and multidirectional shuttle running tracks while wearing a 5 Hz (with interpolated 15 Hz output GPS device. Reference total distance (13 200 m was systematically over- and underestimated during curvilinear (2.61±0.80% and shuttle (-3.17±2.46% trials, respectively. Within-epoch measurement uncertainty dispersion was widest during the shuttle trial, particularly during the jog and run phases. Relative measurement reliability was excellent during both trials (Curvilinear r = 1.00, slope = 1.03, ICC = 1.00; Shuttle r = 0.99, slope = 0.97, ICC = 0.99. Absolute measurement reliability was superior during the curvilinear trial (Curvilinear SEM = 0 m, CV = 2.16%, LOA ± 223 m; Shuttle SEM = 119 m, CV = 2.44%, LOA ± 453 m. Rapid directional change degrades the accuracy and absolute reliability of GPS distance measurement, and caution is recommended when using GPS to quantify rapid multidirectional movement patterns.

  7. Analytical description of stationary ideal MHD flows with constant total pressure

    CERN Document Server

    Golovin, Sergey V

    2009-01-01

    Incompressible stationary flows of ideal plasma are observed. By introduction of curvilinear system of coordinates in which streamlines and magnetic force lines form a family of coordinate surfaces, MHD equations are partially integrated and brought to a certain convenient form. It is demonstrated that the admissible group of Bogoyavlenskij's symmetry transformations performs as a scaling transformation for the curvilinear coordinates. Analytic description of stationary flows with constant total pressure is given. It is shown, that contact magnetic surfaces of such flows are translational surfaces, i.e. are swept out by translating one curve rigidly along another curve. Explicit examples of solutions with constant total pressure possessing a significant functional arbitrariness are given.

  8. The vibrational progressions of the N-->V electronic transition of ethylene: a test case for the computation of Franck-Condon factors of highly flexible photoexcited molecules.

    Science.gov (United States)

    Borrelli, Raffaele; Peluso, Andrea

    2006-11-21

    The vibrational progressions of the N-->V electronic transition of ethylene--a test case for the computation of Franck-Condon factors between electronic states exhibiting very different equilibrium geometries--have been calculated by using both the Cartesian and the curvilinear internal coordinate representations of the normal modes of vibration. The comparison of the theoretical spectra with the experimental one shows that the Cartesian representation yields vibrational progressions which are not observed in the experimental spectrum, whereas the curvilinear one gives a very satisfying agreement, even in harmonic approximation.

  9. Triangular Differential Quadrature for Bending Analysis of Reissner Plates with Curved Boundaries

    Institute of Scientific and Technical Information of China (English)

    华永霞; 钟宏志

    2003-01-01

    The recently proposed concept of the triangular differential quadrature method (TDQM) is applied to the bending analysis of Reissner plates with various curvilinear geometries subjected to various combinations of boundary conditions. A unit isosceles right triangle is used as the standard triangle for all the derivatives expressed using the triangular differential quadrature rule. Geometric transformations are introduced using basis functions to determine the weighting coefficients for the triangular differential quadrature to map an arbitrary curvilinear triangle into the standard triangle. The triangular differential quadrature method provides good accuracy and rapid convergence relative to other available exact and numerical results.

  10. MR appearance of autologous chondrocyte implantation in the knee: correlation with the knee features and clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tomoki [Department of Radiology and Institute of Orthopaedics, Oswestry, Shropshire (United Kingdom); Kumamoto University, Department of Orthopaedic and Neuro-Musculoskeletal Surgery, Kumamoto (Japan); Tins, Bernhard; McCall, Iain W.; Ashton, Karen [Department of Radiology and Institute of Orthopaedics, Oswestry, Shropshire (United Kingdom); Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust, Department of Diagnostic Imaging, Oswestry, Shropshire (United Kingdom); Richardson, James B. [Department of Radiology and Institute of Orthopaedics, Oswestry, Shropshire (United Kingdom); RJAH Orthopaedic Hospital, Institute of Orthopaedics, Oswestry, Shropshire (United Kingdom); Takagi, Katsumasa [Department of Radiology and Institute of Orthopaedics, Oswestry, Shropshire (United Kingdom); Kumamoto Aging Research Institute, Kumamoto (Japan)

    2006-01-01

    To relate the magnetic resonance imaging (MRI) appearance of autologous chondrocyte implantation (ACI) in the knee in the 1st postoperative year with other knee features on MRI and with clinical outcome. Forty-nine examinations were performed in 49 patients at 1 year after ACI in the knee. Forty-one preoperative magnetic resonance (MR) examinations were also available. The grafts were assessed for smoothness, thickness in comparison with that of adjacent cartilage, signal intensity, integration to underlying bone and adjacent cartilage, and congruity of subchondral bone. Presence of overgrowth and bone marrow appearance beneath the graft were also assessed. Presence of osteophyte formation, further cartilage defects, appearance of the cruciate ligaments and the menisci were also recorded. An overall graft score was constructed, using the graft appearances. This was correlated with the knee features and the Lysholm score, a clinical self-assessment score. The data were analysed by a Kruskal-Wallis H test followed by a Mann-Whitney U test with Bonferroni correction as post-hoc test. Of 49 grafts, 32 (65%) demonstrated complete defect filling 1 year postoperatively. General overgrowth was seen in eight grafts (16%), and partial overgrowth in 13 grafts (26%). Bone marrow change underneath the graft was seen; oedema was seen in 23 grafts (47%), cysts in six grafts (12%) and sclerosis in two grafts (4%). Mean graft score was 8.7 (of maximal 12) (95% CI 8.0-9.5). Knees without osteophyte formation or additional other cartilage defects (other than the graft site) had a significantly higher graft score than knees with multiple osteophytes (P=0.0057) or multiple further cartilage defects (P=0.014). At 1 year follow-up improvement in the clinical scores was not significantly different for any subgroup. (orig.)

  11. Disease progression and phasic changes in gene expression in a mouse model of osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Richard F Loeser

    Full Text Available Osteoarthritis (OA is the most common form of arthritis and has multiple risk factors including joint injury. The purpose of this study was to characterize the histologic development of OA in a mouse model where OA is induced by destabilization of the medial meniscus (DMM model and to identify genes regulated during different stages of the disease, using RNA isolated from the joint "organ" and analyzed using microarrays. Histologic changes seen in OA, including articular cartilage lesions and osteophytes, were present in the medial tibial plateaus of the DMM knees beginning at the earliest (2 week time point and became progressively more severe by 16 weeks. 427 probe sets (371 genes from the microarrays passed consistency and significance filters. There was an initial up-regulation at 2 and 4 weeks of genes involved in morphogenesis, differentiation, and development, including growth factor and matrix genes, as well as transcription factors including Atf2, Creb3l1, and Erg. Most genes were off or down-regulated at 8 weeks with the most highly down-regulated genes involved in cell division and the cytoskeleton. Gene expression increased at 16 weeks, in particular extracellular matrix genes including Prelp, Col3a1 and fibromodulin. Immunostaining revealed the presence of these three proteins in cartilage and soft tissues including ligaments as well as in the fibrocartilage covering osteophytes. The results support a phasic development of OA with early matrix remodeling and transcriptional activity followed by a more quiescent period that is not maintained. This implies that the response to an OA intervention will depend on the timing of the intervention. The quiescent period at 8 weeks may be due to the maturation of the osteophytes which are thought to temporarily stabilize the joint.

  12. Two Single-Nucleotide Polymorphisms in ADAM12 Gene Are Associated with Early and Late Radiographic Knee Osteoarthritis in Estonian Population.

    Science.gov (United States)

    Kerna, Irina; Kisand, Kalle; Tamm, Ann E; Kumm, Jaanika; Tamm, Agu O

    2013-01-01

    Objectives. To investigate associations of selected single-nucleotide polymorphisms (SNPs) in ADAM12 gene with radiographic knee osteoarthritis (rKOA) in Estonian population. Methods. The rs3740199, rs1871054, rs1278279, and rs1044122 SNPs in ADAM12 gene were genotyped in 438 subjects (303 women) from population-based cohort, aged 32 to 57 (mean 45.4). The rKOA features were evaluated in the tibiofemoral joint (TFJ) and patellofemoral joint. Results. The early rKOA was found in 51.4% of investigated subjects (72% women) and 12.3% of participants (63% women) had advanced stage of diseases. The A allele of synonymous SNP rs1044122 was associated with early rKOA in TFJ, predominantly with the presence of osteophytes in females (OR 1.57; 95% CI 1.08-2.29, P = 0.018). The C allele of intron polymorphism rs1871054 carried risk for advanced rKOA, mostly to osteophyte formation in TFJ in males (OR 3.03; 95% CI 1.11-7.53, P = 0.018). Also the CCAA haplotype of ADAM12 was associated with osteophytosis, again mostly in TFJ in males (P = 0.014). For rs3740199 and rs1278279, no statistically significant associations were observed. Conclusion.  ADAM12 gene variants are related to rKOA risk during the early and late stages of diseases. The genetic risk seems to be predominantly associated with the appearance of osteophytes-a marker of bone remodelling and neochondrogenesis.

  13. Optimal embedding for shape indexing in medical image databases.

    Science.gov (United States)

    Qian, Xiaoning; Tagare, Hemant D; Fulbright, Robert K; Long, Rodney; Antani, Sameer

    2010-06-01

    This paper addresses the problem of indexing shapes in medical image databases. Shapes of organs are often indicative of disease, making shape similarity queries important in medical image databases. Mathematically, shapes with landmarks belong to shape spaces which are curved manifolds with a well defined metric. The challenge in shape indexing is to index data in such curved spaces. One natural indexing scheme is to use metric trees, but metric trees are prone to inefficiency. This paper proposes a more efficient alternative. We show that it is possible to optimally embed finite sets of shapes in shape space into a Euclidean space. After embedding, classical coordinate-based trees can be used for efficient shape retrieval. The embedding proposed in the paper is optimal in the sense that it least distorts the partial Procrustes shape distance. The proposed indexing technique is used to retrieve images by vertebral shape from the NHANES II database of cervical and lumbar spine X-ray images maintained at the National Library of Medicine. Vertebral shape strongly correlates with the presence of osteophytes, and shape similarity retrieval is proposed as a tool for retrieval by osteophyte presence and severity. Experimental results included in the paper evaluate (1) the usefulness of shape similarity as a proxy for osteophytes, (2) the computational and disk access efficiency of the new indexing scheme, (3) the relative performance of indexing with embedding to the performance of indexing without embedding, and (4) the computational cost of indexing using the proposed embedding versus the cost of an alternate embedding. The experimental results clearly show the relevance of shape indexing and the advantage of using the proposed embedding.

  14. Agreement in the Interpretation of Magnetic Resonance Images of the Lumbar Spine

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, F.M. (Dept. Cientfico, Fundacin Kovacs, Palma de Majorca (Spain)); Royuela, A. (Spanish Back Pain Research Network, Fundacin Kovacs, Palma de Majorca (Spain)); Jensen, T.S. (Back Research Center, Backcenter Funen, Ringe (Denmark)) (and others)

    2009-06-15

    Background: Correlation between clinical features and magnetic resonance imaging (MRI) findings is essential in low-back-pain patients. Most previous studies have analyzed concordance in the interpretation of lumbar MRI among a few radiologists who worked together. This may have overestimated concordance. Purpose: To evaluate intra- and interobserver agreement in the interpretation of lumbar MRI performed in an open 0.2T system. Material and Methods: Seven radiologists from two different geographic settings in Spain interpreted the lumbar MRIs of 50 subjects representative of the general Danish population aged 40 years. The radiologists interpreted the images in routine clinical practice, having no knowledge of the clinical and demographic characteristics of the subjects and blinded to their colleagues' assessments. Six of the radiologists evaluated the same MRIs 14 days later, having no knowledge of the previous results. Data on the existence of disc degeneration, high-intensity zones, disc contour, Schmorl nodes, Modic changes, osteophytes, spondylolisthesis, and spinal stenosis were collected in the Nordic Modic Consensus Group Classification form. Intra- and interobserver agreement was analyzed for variables with a prevalence =10% and =90% by means of the kappa statistic. Results: Intra- and interobserver agreement was excellent for variables related to Modic changes, and fair to good for disc contour, high-intensity zones, and Schmorl nodes. The evaluations for disc degeneration and osteophytes were found to have fair to good intraobserver agreement and poor interobserver agreement. The agreement for the evaluations of spondylolisthesis and spinal stenosis was not analyzed because they were observed in <10% of reports. Conclusion: Images from 0.2T MRIs appear to lead to good agreement in the reporting of disc contour, high-intensity zones, Schmorl nodes, and, in particular, Modic changes, suggesting that they can possibly be reliably used for clinical

  15. Significance of arthrosonography for knee joint damage diagnosis in patients with early rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    L V Sizova

    2008-01-01

    Full Text Available Objective. To assess significance of arthrosonography in diagnosis of in knee joint changes in patients with early rheumatoid arthritis (RA. Material and methods. 44 patients with early RA aged 19 to 73 years were examined. 29,5% of pts had early RA without primary osteoarthritis (OA, 70,5% had early RA with primary OA. Ultrasonography of knee joints was performed with Diasonics (USA, 1997 by the linear sensor with frequency of 7 MHz. The protocol of ultrasonic examination of knee joints was filled for each pt. Results. Clinical signs of of knee joint synovitis have been revealed in 61,5% of pts with early RA without primary OA, and in 80,6% of pts with early RA with primary OA, ultrasonic - in 100% of pts. Intraarticular knee joint effusion resulted in increase of suprapatellar bursa and lateral recesses size. Extraarticular inflammation was frequently shown by thickening of semymemranous muscles tendons, especially in pts with the early RA with primary OA (p<0,005. Degenerative changes in the group of pts with primary OA were more expressed in early RA and usually accompanied by non-uniform decrease of cartilage thickness and occurrence of osteophytes while cartilage in pts with early RA without primary OA had normal thickness or thickening because of swelling, and osteophytes were absent. Conclusion. Prevalence of knee joint intraarticular and extraarticular inflammatory changes over degenerate changes (symmetric thickening of the synovium, primary increase of the sizes of suprapatellar bursa and lateral recesses because of effusion, thickening of tendons of knee joints at the normal or increased thickness of cartilage because of inflammation can be considered sonographic sign of early RA. In pts with early RA coincided with primary OA these changes were usually found in combination with non-uniform decrease of cartilage thickness. In case of cartilage inflammatory edema, detection of osteophytes allows to confirm presence of OA in pts with

  16. Cervical disc hernia operations through posterior laminoforaminotomy

    Directory of Open Access Journals (Sweden)

    Coskun Yolas

    2016-01-01

    Full Text Available Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years. Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%. On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis.

  17. Radiographic findings in patients with clinical Tietze syndrom

    Energy Technology Data Exchange (ETDEWEB)

    Jurik, A.G.; Justesen, T.; Graudal, H.

    1987-10-01

    Thirteen patients with similar painful tender swelling in the region of the sternocostal joint (SCJ) are reported. X-ray tomography revealed changes which might explain the swelling in 11 patients. Three patients had anatomical variants of the sternum. One of these and a further two patients had marginal osteophytes at the affected SCJ, as signs of osteoarthrosis. Six patients with psoriasis, pustulosis palmoplantaris, or psoriasis in the family had past or present arthritis of the involved SCJ or the manubriosternal joint. Tomography was found to be a useful confirmatory examination in patients with clinical Tietze syndrome.

  18. Is orthopantomography reliable for TMJ diagnosis? An experimental study on a dry skull.

    Science.gov (United States)

    Ruf, S; Pancherz, H

    1995-01-01

    The accuracy of orthopantomography in reproducing the temporomandibular joint area was analyzed on a dry skull. The results based on this study of a single skull revealed that the radiographic image of the temporomandibular joint did not correspond to the anatomic condylar and fossa components or to their actual relationship. To a large extent, changes in skull position affected the radiographic temporomandibular joint image, simulating anterior condylar flattening, osteophytes, narrowing of joint space, and left/right condylar asymmetry. Orthopantomography may have questionable reliability for temporomandibular joint diagnostic purposes.

  19. Superior dislocation of the patella: a case report

    Directory of Open Access Journals (Sweden)

    Garcia-Balletbo Montserrat

    2009-07-01

    Full Text Available Abstract Background Superior dislocation of the patella is an uncommon condition that mainly occurs in knees with a high patella and medial femorotibial degenerative arthritis. There are no previous reports of this condition occurring in association with tibial valgus osteotomy. Case report: We report the case of a patient in whom vertical dislocation recurred twice at 4 months after tibial valgus osteotomy. To avert additional recurrence or new dislocations, the patient was treated surgically to remove the existing osteophytes. Conclusions: An arthroscopic approach was decided because of the lower associated morbidity and good results with this technique compared to open surgery.

  20. A diagnostic and therapeutic challenge involving a case of dysphagia in association with cervical osteophytosis and a dental pain

    Directory of Open Access Journals (Sweden)

    Rajani A Dable

    2013-01-01

    Full Text Available Herein, presenting a case of a 42-year-old female with the chief complaint of dysphagia. The problem was assumed to be of dental origin, due to the onset of dental pain followed by dysphagia. A cervical radiograph revealed the presence of osteophytic lipping which proved to be the cause of dysphagia. Confusing and overlapping disease entities showing similar symptoms need thorough investigation. Dysphagia related to cervical spondylosis may have a direct connection with the person′s occupation. Dentistry is considered a potentially hazardous occupation with regard to musculoskeletal disorders. However, additional studies are required to understand the occupational hazards faced by dentists.

  1. MRI cervical spine findings in asymptomatic fighter pilots.

    Science.gov (United States)

    Petrén-Mallmin, M; Linder, J

    1999-12-01

    MRI of the cervical spine for evaluation concerning degenerative lesions was performed on asymptomatic experienced military high performance aircraft pilots (mean age 42 yr with mean accumulated flying time of 2600 h), and for comparison on age-matched controls without military flying experience. Young military high performance aircraft pilots (mean age 23 yr with 220 h of flying per person) were also examined. There were significantly more osteophytes, disk protrusions, compressions of the spinal cord and foraminal stenoses in the experienced pilots than in the age-matched controls. Low frequency of low grade degenerative lesions was found in the young and inexperienced pilots.

  2. MR imaging of the elbow in the injured athlete.

    Science.gov (United States)

    Wenzke, Daniel R

    2013-03-01

    This article summarizes key MR imaging findings in common athletic elbow injuries including little leaguer's elbow, Panner disease, osteochondritis dissecans, olecranon stress fracture, occult fracture, degenerative osteophyte formation, flexor-pronator strain, ulnar collateral ligament tear, lateral ulnar collateral ligament and radial collateral ligament tear, lateral epicondylitis, medial epicondylitis, biceps tear, bicipitoradial bursitis, triceps tear, olecranon bursitis, ulnar neuropathy, posterior interosseous nerve syndrome, and radial tunnel syndrome. The article also summarizes important technical considerations in elbow MR imaging that enhance image quality and contribute to the radiologist's success.

  3. Footballer's ankle: a case report

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Footballer' s ankle is anterior bony spur or anterior impingement symptom of the ankle with anterior ankle pain, limited and painful dorsiflexion. The cause is commonly seen in athletes and dancers, and is probably due to repetitive minor trauma. The condition was firstly described by Morris;1 McMurray2 reported good results from excision of the spurs, naming it footballer's ankle. Opening resection of osteophytes of the anterior tibial and superior talar is an effective treatment for anterior impingement of the ankle.

  4. Is there an association between a low acromion index and osteoarthritis of the shoulder?

    OpenAIRE

    2009-01-01

    The aim of this study was to evaluate the relationship between a low acromion index and osteoarthritis of the shoulder. Three patient groups were used: (I) instability, n = 53; (II) calcifying tendonitis, n = 109; and (III) osteoarthritis, n = 120. Standardised digital X-rays were evaluated from the true anteroposterior and axillary views. Joint space width at three levels in each plane and the size of humeral osteophytes were measured and osteoarthritis was graded according to Samilson. The ...

  5. Combined spinal–epidural anesthesia for an elderly patient with proportionate dwarfism for laparotomy

    Directory of Open Access Journals (Sweden)

    Teena Bansal

    2016-01-01

    Full Text Available Anesthesia in a dwarf patient may be challenging as various anatomical anomalies make both general and regional anesthesia difficult. These patients may have atlantoaxial instability, potential for airway obstruction, and associated respiratory problems that may pose problems for general anesthesia. Spinal stenosis, osteophytes, short pedicles, or a small epidural space could complicate regional anesthesia in dwarfs which could lead to difficulties in locating the epidural space and increase the risk of dural puncture. Spinal stenosis may impair cerebrospinal fluid flow such that identification of dural puncture is difficult. This elderly dwarf patient had history of bronchial asthma with restriction of neck extension, managed successfully using combined spinal–epidural anesthesia.

  6. Macrodystrophia Lipomatosa of the Toe: A Rare Case Report

    Science.gov (United States)

    Durairaj, Alagar Raja

    2016-01-01

    Macrodystrophia lipomatosa is a rare congenital hamartoma presenting as a localized or generalized gigantism of a limb or digit manifesting from infancy to late adulthood. It is a progressive enlargement of the soft tissue components, especially fibrofatty tissue. The patient presents to us because of cosmetic reasons or mechanical issues secondary to degenerative joint disease, or features of neurovascular compression due to large osteophytes. Here, we present a case of this anomaly of the left second toe with complaints of difficulty in walking and wearing shoes, for which toe reduction surgery with partial amputation was done. PMID:27190893

  7. SMAD3 is associated with the total burden of radiographic osteoarthritis: the Chingford study.

    Directory of Open Access Journals (Sweden)

    Erfan Aref-Eshghi

    Full Text Available BACKGROUND: A newly-described syndrome called Aneurysm-Osteoarthritis Syndrome (AOS was recently reported. AOS presents with early onset osteoarthritis (OA in multiple joints, together with aneurysms in major arteries, and is caused by rare mutations in SMAD3. Because of the similarity of AOS to idiopathic generalized OA (GOA, we hypothesized that SMAD3 is also associated with GOA and tested the hypothesis in a population-based cohort. METHODS: Study participants were derived from the Chingford study. Kellgren-Lawrence (KL grades and the individual features of osteophytes and joint space narrowing (JSN were scored from radiographs of hands, knees, hips, and lumbar spines. The total KL score, osteophyte score, and JSN score were calculated and used as indicators of the total burden of radiographic OA. Forty-one common SNPs within SMAD3 were genotyped using the Illumina HumanHap610Q array. Linear regression modelling was used to test the association between the total KL score, osteophyte score, and JSN score and each of the 41 SNPs, with adjustment for patient age and BMI. Permutation testing was used to control the false positive rate. RESULTS: A total of 609 individuals were included in the analysis. All were Caucasian females with a mean age of 60.9±5.8. We found that rs3825977, with a minor allele (T frequency of 20%, in the last intron of SMAD3, was significantly associated with total KL score (β = 0.14, Ppermutation = 0.002. This association was stronger for the total JSN score (β = 0.19, Ppermutation = 0.002 than for total osteophyte score (β = 0.11, Ppermutation = 0.02. The T allele is associated with a 1.47-fold increased odds for people with 5 or more joints to be affected by radiographic OA (Ppermutation = 0.046. CONCLUSION: We found that SMAD3 is significantly associated with the total burden of radiographic OA. Further studies are required to reveal the mechanism of the association.

  8. 以咽异物感为表现的食管型颈椎病1例%One cases of esophageal cervical spondylosis with pharyngeal foreign body sensation

    Institute of Scientific and Technical Information of China (English)

    齐志勇; 张治平; 呼和牧仁; 鄂建新

    2012-01-01

    The patient was treated as pharyngeal foreign body sensation for six months. Laryngeal endosco-pys one about 1 cmX2 cmX2 cm,hard.smooth bulge in hypopharyngeal wall at the plane of epiglottis valley. The cervical MRI showed that the C3-C4 disc herniation and degeneration of the C3-C4 vertebrae. Cervical CT showed the C3-C4 disc osteophyte formation and forward bulge. After orthopedic consultation, the patient was diagnosed as esophageal cervical spondylosis. C3-C4 diskectomy and vertebral interbody bone grafted with plate fixation were undertaken. At postoperational day 2, the pharyngeal foreign body sensation disappeared.

  9. SOLITARY EPIPHYSEAL PEDUNCULATED OSTEOCHONDROMA WITH SECONDARY OSTEOARTHRITIS: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2015-04-01

    Full Text Available Osteochondroma is the relatively common bone tumor arising from the metaphysis of long bones . Osteochondroma arising from epiphysis of long bones are very rare . We report a case of a 67 year old man with history of right shoulder pain for past 5 years and difficulty in moving the arm for past 1 year . X - ray showed severe osteophytic changes and a subtle bony outgrowth from head of humerus . MRI showed cartilage capped bony outgrowth arising from the epiphysis of humerus . Medullary cavity of the lesion is seen communicating with the medullary cavity of bone consistent with osteochondroma .

  10. An unusual complication of the Mackenzie approach for a Copeland hemiarthroplasty

    Directory of Open Access Journals (Sweden)

    Sarah E Johnson-Lynn

    2011-01-01

    Full Text Available We report the case of a patient with end-stage osteoarthritis who received a successful Copeland resurfacing hemiarthroplasty through a Mackenzie anterosuperior approach, which involves taking the anterior portion of the deltoid attachment from the acromion along with an osteo-periosteal sleeve. The patient went on to develop severe subacromial impingement symptoms 4 months postoperatively. X-rays revealed a large anteroinferior acromial osteophyte that had not been present preoperatively and was deemed to represent a malunited osteo-periosteal sleeve from the Mackenzie approach.

  11. Particle-based technologies for osteoarthritis detection and therapy.

    Science.gov (United States)

    Kavanaugh, Taylor E; Werfel, Thomas A; Cho, Hongsik; Hasty, Karen A; Duvall, Craig L

    2016-04-01

    Osteoarthritis (OA) is a disease characterized by degradation of joints with the development of painful osteophytes in the surrounding tissues. Currently, there are a limited number of treatments for this disease, and many of these only provide temporary, palliative relief. In this review, we discuss particle-based drug delivery systems that can provide targeted and sustained delivery of imaging and therapeutic agents to OA-affected sites. We focus on technologies such as polymeric micelles and nano-/microparticles, liposomes, and dendrimers for their potential treatment and/or diagnosis of OA. Several promising studies are highlighted, motivating the continued development of delivery technologies to improve treatments for OA.

  12. Particle Based Technologies for Osteoarthritis Detection and Therapy

    Science.gov (United States)

    Kavanaugh, Taylor E.; Werfel, Thomas A.; Cho, Hongsik; Hasty, Karen A.; Duvall, Craig L.

    2015-01-01

    Osteoarthritis (OA) is a disease characterized by degradation of joints with the development of painful osteophytes in the surrounding tissues. Currently, there are a limited number of treatments for this disease and many of these only provide temporary, palliative relief. In this review, we discuss polymer drug delivery systems that can provide targeted and sustained delivery of imaging and therapeutic agents to OA-affected sites. We focus on technologies such as polymeric micelles and nano- / micro-particles, liposomes, and dendrimers for their potential treatment and/or diagnosis of OA. Several promising studies are highlighted, motivating the continued development of delivery technologies to improve treatments for OA. PMID:25990835

  13. Lateral epicondylar osteotomy for severe varus deformity during total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    Hong Chen; Wei Huang; Xi Liang; Ning Hu; Wei Xu; Dianming Jiang

    2015-01-01

    In most cases of arthritic varus knees, stepwise osteophytes removal and medial soft tissue release could achieve satisfactory soft tissue balance during total knee arthroplasty.However, in some severe cases, conventional balancing techniques are not enough, necessitating other procedures like epicondylar osteotomy.To the best of our knowledge, no published article has reported the application of lateral epicondylar osteotomy in a severe varus knee.Here we reported a case of successful correction of a severe varus knee following lateral epicondylar osteotomy, and described its underlying rationale.

  14. The Relationship between Engagement in Cocurricular Activities and Academic Performance: Exploring Gender Differences

    Science.gov (United States)

    Zacherman, Avi; Foubert, John

    2014-01-01

    The effects of time spent in cocurricular activities on academic performance was tested. A curvilinear relationship between hours per week spent involved in cocurricular activities and grade point average was discovered such that a low amount of cocurricular involvement was beneficial to grades, while a high amount can potentially hurt academic…

  15. The Downsides of Extreme Conscientiousness for Psychological Well-being: The Role of Obsessive Compulsive Tendencies.

    Science.gov (United States)

    Carter, Nathan T; Guan, Li; Maples, Jessica L; Williamson, Rachel L; Miller, Joshua D

    2016-08-01

    Although conscientiousness exhibits positive relations with psychological well-being, theoretical and empirical work suggests individuals can be too conscientious, resulting in obsessive-compulsiveness, and therein less positive individual outcomes. However, the potential for curvilinearity between conscientiousness and well-being has been underexplored. We measured 912 subjects on facets of conscientiousness, obsessive-compulsive personality, and well-being variables (life satisfaction, job satisfaction, self-esteem, positive affect, negative affect, work stress). Methods of scoring included traditional sum-scoring, traditional item response theory (IRT), and a relatively new IRT approach. Structural models were estimated to evaluate curvilinearity. Results confirmed the curvilinear relationship between conscientiousness and well-being, and demonstrated that differential facet-level relationships underlie weaker curvilinearity at the general trait level. Consistency was found in the strength of relation between conscientiousness facets with their obsessive-compulsive variants and their contribution to decreased well-being. The most common association was that higher standing on conscientiousness facets was positively related to negative affect. Findings support the idea that extreme standing on facets of conscientiousness more strongly linked to their obsessive-compulsive variants contributed to lower well-being, highlighting the importance of considering alternative functional representations of the relationship between personality and other constructs. Future work should seek to further clarify the link between conscientiousness and negative affect.

  16. FIRO-B, Machiavellianism, and teams.

    Science.gov (United States)

    Macrosson, W D; Semple, J H

    2001-06-01

    A correlational study using the Mach IV and FIRO-B questionnaires examined the attitudes of 120 postgraduate and undergraduate students, the majority of whom had significant work experience. A curvilinear relationship observed between the FIRO-B and Mach IV scales calls into question an aspect of Will Schutz's prescription for interpersonal compatibility.

  17. Numerical Analysis on Longitudinal Location Optimization of Vortex Generator in Compact Heat Exchangers

    DEFF Research Database (Denmark)

    Gorji, M.; Mirgolbababei, H.; Barari, Amin

    2011-01-01

    In this paper, numerical, curvilinear and turbulent model has been used to investigate the effect of vortex generator's longitudinal displacement on heat transfer and fluid flow in different Reynolds numbers ranging from 500 to 3000. The numerical model has been validated with experimental result...

  18. Is there a map between Galilean relativity and special relativity?

    OpenAIRE

    Shariati, Ahmad; Jafari, N.

    2014-01-01

    Mandanici has provided a map which he claims to be a two way map between Galilean relativity and special relativity. We argue that this map is simply a curvilinear coordinate system on a subset of the two-dimensional Minkowski space-time, and is not a two way map between 1+1 dimensional Galilean relativity and 1+1 dimensional special relativity.

  19. 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...

  20. Water productivity of maize in the U.S. High Plains

    Science.gov (United States)

    Maize water production functions measured in a 4 year field trial in the U.S. central High Plains were curvilinear with 2.0 kg m-3 water productivity at full irrigation that resulted from 12.5 Mg ha-1 grain yields with 630 mm of crop evapotranspiration, ETc. The functions show decreasing yield but ...

  1. Augmented Electric and Magnetic-Field Integral Equations

    Science.gov (United States)

    1981-03-01

    depend only on this one tangential curvilinear coordinate. Consider the Mainardi -Codazzi relations of differential geometry describing the surface S...of the axis with a velocity proportional to the velocity of rotation. (The theorem is proven using the Mainardi -Codazzi and Gauss equations.) Bodies

  2. In Search of Nonlinear Process-Product Functions in Existing Schooling Effects Data: I. A Reanalysis of the First Grade Reading and Mathematics Data From the Stallings and Kaskowitz Follow Through Study.

    Science.gov (United States)

    Rim, Eui-Do; Coller, Alan R.

    As an attempt to confirm the view that the relationships between certain classroom process variables and student achievement are curvilinear, first grade reading and mathematics data from the Stallings and Kaskowitz (1974) Project Follow Through Classroom Observation Evaluation were reanalyzed using orthogonal polynomial regression methods.…

  3. On the continua in two-dimensional nonadiabatic magnetohydrodynamic spectra

    NARCIS (Netherlands)

    De Ploey, A.; Van der Linden, R. A. M.; Belien, A. J. C.

    2000-01-01

    The equations for the continuous subspectra of the linear magnetohydrodynamic (MHD) normal modes spectrum of two-dimensional (2D) plasmas are derived in general curvilinear coordinates, taking nonadiabatic effects in the energy equation into account. Previously published derivations of continuous sp

  4. Money Buys Financial Security and Psychological Need Satisfaction: Testing Need Theory in Affluence

    Science.gov (United States)

    Howell, Ryan T.; Kurai, Mark; Tam, Leona

    2013-01-01

    The most prominent theory to explain the curvilinear relationship between income and subjective well-being (SWB) is need theory, which proposes that increased income and wealth can lead to increased well-being in poverty because money is used to satisfy basic physiological needs. The present study tests the tenets of need theory by proposing that…

  5. Numerical Investigation of Heat Transfer Augmentation through Geometrical Optimization of Vortex Generators

    DEFF Research Database (Denmark)

    Gorji, Mofid; Mirgolbabaei, Hessam; Barari, Amin;

    2010-01-01

    In this paper a two-dimensional numerical simulation of a steady incompressible and turbulent model has been carried out to study the effects of vortex generators in a compact heat exchanger in a curvilinear coordinate system. The mesh which is applied in this study is boundary fitted and has bee...

  6. ИСПОЛЬЗОВАНИЕ МОДЕЛИ МАГНИТНОГО ГИДРОЦИКЛОНА ДЛЯ РАСЧЕТА ЭФФЕКТИВНОСТИ ОЧИСТКИ

    Directory of Open Access Journals (Sweden)

    ГОЛИКОВ Сергей Павлович

    2014-05-01

    Full Text Available Model of interaction between the magnetic particles in a curvilinear flow cleaning device of inertial type is shown. Dependence of particle concentration at the inlet purification efficiency hydrocyclone the radial magnetic field is shown. Optimal design type is defined on the basis of the forces acting on a particle in a curved flow.

  7. Impact of contour on aesthetic judgments and approach-avoidance decisions in architecture.

    Science.gov (United States)

    Vartanian, Oshin; Navarrete, Gorka; Chatterjee, Anjan; Fich, Lars Brorson; Leder, Helmut; Modroño, Cristián; Nadal, Marcos; Rostrup, Nicolai; Skov, Martin

    2013-06-18

    On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that the physical features of the places we live and work in influence how we feel and act. However, there is surprisingly little research on how architecture impacts behavior, much less on how it influences brain function. To begin closing this gap, we conducted a functional magnetic resonance imaging study to examine how systematic variation in contour impacts aesthetic judgments and approach-avoidance decisions, outcome measures of interest to both architects and users of spaces alike. As predicted, participants were more likely to judge spaces as beautiful if they were curvilinear than rectilinear. Neuroanatomically, when contemplating beauty, curvilinear contour activated the anterior cingulate cortex exclusively, a region strongly responsive to the reward properties and emotional salience of objects. Complementing this finding, pleasantness--the valence dimension of the affect circumplex--accounted for nearly 60% of the variance in beauty ratings. Furthermore, activation in a distributed brain network known to underlie the aesthetic evaluation of different types of visual stimuli covaried with beauty ratings. In contrast, contour did not affect approach-avoidance decisions, although curvilinear spaces activated the visual cortex. The results suggest that the well-established effect of contour on aesthetic preference can be extended to architecture. Furthermore, the combination of our behavioral and neural evidence underscores the role of emotion in our preference for curvilinear objects in this domain.

  8. Calculation of Eddy currents in the ETE spherical torus

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto

    2002-07-01

    A circuit model based on a Green's function method was developed to evaluate the currents induced during startup in the vessel of ETE (Spherical Tokamak Experiment). The eddy currents distribution is calculated using a thin shell approximation for the vacuum vessel and local curvilinear coordinates. The results are compared with values of the eddy currents measured in ETE. (author)

  9. A numerical grid generation technique

    NARCIS (Netherlands)

    Gilding, B.H.

    1988-01-01

    The paper describes a technique for the generation of boundary-fitted curvilinear coordinate systems for the numerical solution of partial differential equations in two space dimensions. The technique is algebraic, has a transfinite character, and is based on the blending of shearing transformations

  10. Developmental Changes in Parent-Child Communication throughout Adolescence

    Science.gov (United States)

    Keijsers, Loes; Poulin, François

    2013-01-01

    This study examined how parent-child communication regarding adolescent unsupervised activities develops over the course of adolescence. We used questionnaire data from 390 adolescents (58% girls; 90% European Canadian) who were followed from age 12 to 19. Latent growth curve modeling revealed curvilinear developmental changes that differed for…

  11. Continuous magnetohydrodynamic spectra of two-dimensional coronal magnetostatic flux tubes

    NARCIS (Netherlands)

    Belien, A. J. C.; Poedts, S.; Goedbloed, J. P.

    1997-01-01

    In this paper we derive the equations for the continuous ideal magnetohydrodynamic (MHD) spectrum of two-dimensional coronal loops, including gravity and expansion, in general curvilinear coordinates. The equations clearly show the coupling between Alfven and slow magnetosonic continuum waves when b

  12. Patterns of Visual Attention to Faces and Objects in Autism Spectrum Disorder

    Science.gov (United States)

    McPartland, James C.; Webb, Sara Jane; Keehn, Brandon; Dawson, Geraldine

    2011-01-01

    This study used eye-tracking to examine visual attention to faces and objects in adolescents with autism spectrum disorder (ASD) and typical peers. Point of gaze was recorded during passive viewing of images of human faces, inverted human faces, monkey faces, three-dimensional curvilinear objects, and two-dimensional geometric patterns.…

  13. Analytic Simulation of Tissue Damage from Penetrating Wounds to the Heart

    Science.gov (United States)

    2006-12-01

    from Penetrating Wounds to the Heart PRINCIPAL INVESTIGATOR: Robert D. Eisler Amiya K...0084 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Robert D. Eisler 5d. PROJECT NUMBER Amiya K. Chatterjee Steven F...solutions in curvilinear geometries”, Journal of Vibrations and Acoustics, Transactions of the ASME 125, 133-136. [6] Hamdi, S., Enright , W., Schiesser

  14. Defining dimensions of distinctiveness : Group variability makes a difference to differentiation

    NARCIS (Netherlands)

    Jetten, J; Spears, R; Manstead, ASR

    1998-01-01

    We tested the prediction, derived from an integration of social identity and self-categorization principles, that the relation between in-group distinctiveness and positive differentiation is curvilinear. Moderate distinctiveness is argued to provide the critical combination of intergroup difference

  15. Modeling of Airfoil Trailing Edge Flap with Immersed Boundary Method

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Shen, Wen Zhong; Sørensen, Jens Nørkær

    2011-01-01

    to simulate the moving part of the trailing edge. Over the main fixed part of the airfoil the Navier-Stokes (NS) equations are solved using a standard body-fitted finite volume technique whereas the moving trailing edge flap is simulated with the immersed boundary method on a curvilinear mesh. The obtained...

  16. Radiation from charges in the continuum limit

    CERN Document Server

    Ianconescu, Reuven

    2012-01-01

    It is known that an accelerating charge radiates according to Larmor formula. On the other hand, any DC current following a curvilinear path, e.g. a circular loop, consists of accelerating charges, but in such case the radiated power is 0. The scope of this paper is to analyze and quantify how the radiation vanishes when one goes to the continuum DC limit.

  17. Logic and Belief across the Lifespan: The Rise and Fall of Belief Inhibition during Syllogistic Reasoning

    Science.gov (United States)

    De Neys, Wim; Van Gelder, Elke

    2009-01-01

    Popular reasoning theories postulate that the ability to inhibit inappropriate beliefs lies at the heart of the human reasoning engine. Given that people's inhibitory capacities are known to rise and fall across the lifespan, we predicted that people's deductive reasoning performance would show similar curvilinear age trends. A group of children…

  18. Rescue of ligand binding of a mutant IGF-I receptor by complementation

    DEFF Research Database (Denmark)

    Chakravarty, Arjun Anders; Hinrichsen, Jane; Whittaker, Linda;

    2005-01-01

    The IGF-I receptor binds IGF-I with complex kinetics characterized by a curvilinear Scatchard plot, suggesting receptor heterogeneity and apparent negative cooperativity. To explore the molecular mechanisms underlying these properties, we have characterized the binding of a hybrid receptor formed...

  19. Modelling positional uncertainty of line features by accounting for stochastic deviations from straight line segments

    NARCIS (Netherlands)

    Bruin, de S.

    2008-01-01

    The assessment of positional uncertainty in line and area features is often based on uncertainty in the coordinates of their elementary vertices which are assumed to be connected by straight lines. Such an approach disregards uncertainty caused by sampling and approximation of a curvilinear feature

  20. Study of multiple cracks in airplane fuselage by micromechanics and complex variables

    Science.gov (United States)

    Denda, Mitsunori; Dong, Y. F.

    1994-01-01

    Innovative numerical techniques for two dimensional elastic and elastic-plastic multiple crack problems are presented using micromechanics concepts and complex variables. The simplicity and the accuracy of the proposed method will enable us to carry out the multiple-site fatigue crack propagation analyses for airplane fuselage by incorporating such features as the curvilinear crack path, plastic deformation, coalescence of cracks, etc.

  1. Keystone ø-lap til rekonstruktion af huddefekter

    DEFF Research Database (Denmark)

    Breiting, Line Bro; Venzo, Alessandro; Dahlstrøm, Karin

    2009-01-01

    INTRODUCTION: The keystone design perforator island flap was first described in 2003. It is a local flap based on axial perforators from the underlying structures. It is designed as a curvilinear shaped trapezoidal design flap which is essentially two V-Y flaps end to end. Most reports...

  2. Closer to nature – bio-inspired patterns by transforming latent lithographic images

    NARCIS (Netherlands)

    Giselbrecht, Stefan; Reinhardt, Martina; Mappes, Timo; Börner, Martin; Gottwald, Eric; Blitterswijk, van Clemens; Saile, Volker; Truckenmüller, Roman

    2011-01-01

    Inspired by nature, a new strategy to create three-dimensional organic structures spanning orders of magnitude by using a combination of deep UV or X-ray direct lithography with a solid-state forming process. The stored latent lithographic image is transferred to three-dimensional curvilinear surfac

  3. Toward a scalable flexible-order model for 3D nonlinear water waves

    DEFF Research Database (Denmark)

    Engsig-Karup, Allan Peter; Ducrozet, Guillaume; Bingham, Harry B.

    for flexibility in the description of structures by the use of curvilinear boundary-fitted meshes. The mathematical equations for potential waves in the physical domain is transformed through $\\sigma$-mapping(s) to a time-invariant boundary-fitted domain which then becomes a basis for an efficient solution...

  4. Optimum Design of Steered Fibre Composite Cylinders with Arbitrary Cross-sections

    NARCIS (Netherlands)

    Khani, A.

    2013-01-01

    Automated fibre placement (AFP) machines are able to place simultaneously several bundles of fibres, called tows, on a surface. Using AFP machines, it is also possible to manufacture composite laminates with fibres placed in curvilinear paths. The fibre orientations and stiffness properties of these

  5. Introduction to the general relativity; Introduction a la relativite generale

    Energy Technology Data Exchange (ETDEWEB)

    Radix, J.C.

    1994-12-31

    This work deals with the introduction of the general relativity including the introduction of the tensorial calculation, the Euclidean space in curvilinear coordinates, the Riemann space, the recalls and complements of the restricted relativity and the elements of the general relativity. (O.L.) 83 figs., 3 tabs.

  6. ABCD matrices for non-rectilinear propagation of light

    CERN Document Server

    Ornigotti, Marco

    2013-01-01

    We present a generalization of the ABCD matrix formalism of paraxial optics, showing that the usual ABCD matrix is a 2x2 sub-matrix of a more general infinite matrix describing the full nonlinear dynamics of a curvilinear ray of light

  7. Intelligence and Personal Influence in Groups: Four Nonlinear Models.

    Science.gov (United States)

    Simonton, Dean Keith

    1985-01-01

    Four models are developed to provide a conceptual basis for a curvilinear relation between intelligence and an individual's influence over group members. The models deal with influence and percentile placement in intelligence, comprehension by potential followers, vulnerability to rival intellects, and correlation between mean group IQ and the…

  8. Northwest Coast Indian Art.

    Science.gov (United States)

    Manning, Thomas; Knecht, Elizabeth

    The visual art forms of the Northwest Coast Indian Tribes of Alaska (Haida, Tlingit, and Tsimshian) share common distinctive design elements (formline, ovoid, U-form, and curvilinear shapes) which are referred to as the "Northern Style." Designs represent events or characters taken from the oral tradition of song and legend.…

  9. Application of Adaptive Counseling and Therapy to Career Counseling.

    Science.gov (United States)

    Anderson, Mary Z.; Tracey, Terence J.

    1995-01-01

    Adaptive Counseling and Therapy theory predicts that counseling efficacy depends on a match between counselor style and client readiness. Data from 137 females and 54 males showed a negative relationship between client readiness and preference for directive counseling and a curvilinear (inverted U) relationship between readiness and preference for…

  10. Aging, Terminal Decline, and Terminal Drop

    Science.gov (United States)

    Palmore, Erdman; Cleveland, William

    1976-01-01

    Data from a 20-year longitudinal study of persons over 60 were analyzed by step-wise multiple regression to test for declines in function with age, for terminal decline (linear relationship to time before death), and for terminal drop (curvilinear relationship to time before death). There were no substantial terminal drop effects. (Author)

  11. In vivo behaviour of human muscle architecture and mechanomyographic response using the interpolated twitch technique.

    Science.gov (United States)

    Ohta, Yoichi; Shima, Norihiro; Yabe, Kyonosuke

    2009-06-01

    This study investigated the origin of curvilinear change in the superimposed mechanomyogram (MMG) amplitude of the human medial gastrocnemius muscle (MG) with increasing contraction intensity. The superimposed twitch amplitude, the superimposed MMG amplitude and the extent of fascicle shortening were measured using ultrasonic images of electrical stimulation during isometric plantar flexions at levels 20%, 40%, 60%, 80%, and 100% of the maximal voluntary contraction (MVC). The superimposed twitch amplitude, the superimposed MMG amplitude and the extent of fascicle shortening decreased with increasing contraction intensity. The superimposed MMG amplitude and the extent of fascicle shortening showed a curvilinear decrease, while the superimposed twitch amplitude showed a linear decrease at levels up to 80% of the MVC. There was a linear relationship between the superimposed MMG amplitude and the extent of fascicle shortening at different contraction intensities. These results indicate that the superimposed MMG amplitude reflects changes in the extent of fascicle shortening at different contraction intensities better than the superimposed twitch amplitude. Our study suggests that the origin of the curvilinear decrease of superimposed MMG amplitude is associated with a curvilinear decrease of the extent of fascicle shortening with increasing contraction intensity in the human MG.

  12. Method of calculation and construction of arrangement sketchy of stone-working machine for the processing of geometrically-complex surfaces of wares of large gabarit

    OpenAIRE

    Чемоданов, Петро Арисович

    2016-01-01

    In the article the method of calculation of basic knots and arrangement sketchy of stone-working gantry milling mapping machine is offered with curvilinear working motion of light cart for the processing of geometrically-complex surfaces on the stoning purveyance of large gabarit.

  13. The differential equations defining deflection of particles of ion beam from axial trajectory in electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Baisanov, O.A. [Military Institute of Air Defense Forces, Aktobe (Kazakhstan); Doskeyev, G.A.; Doskeyev, T.G. [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan); Spivak-Lavrov, I.F., E-mail: spivakif@rambler.ru [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan)

    2011-07-21

    The exact differential equations defining deviations of the paths of charged particles from the axial trajectory are derived in curvilinear coordinates. These equations are in a form suited for carrying out relativistically correct numerical calculations of the dynamics of charged particle beams.

  14. Gluten Protein Composition in Several Fractions Obtained by Shear Induced Separation of Wheat Flour

    NARCIS (Netherlands)

    Zalm, van der E.E.J.; Grabowska, K.J.; Strubel, M.; Goot, van der A.J.; Hamer, R.J.; Boom, R.M.

    2010-01-01

    Recently, it was found that applying curvilinear shear flow in a cone-cone shearing device to wheat flour dough induces separation, resulting in a gluten-enriched fraction in the apex of the cone and gluten-depleted fraction at the outer part. This article describes whether fractionation of the vari

  15. DEVELOPMENT AND APPLICATIONS OF WENO SCHEMES IN CONTINUUM PHYSICS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper briefly presents the general ideas of high order accurate weighted essentially non-oscillatory (WENO) schemes, and describes the similarities and differences of the two classes of WENO schemes: finite volume schemes and finite difference schemes. We also briefly mention a recent development of WENO schemes,namely an adaptive approach within the finite difference framework using smooth time dependent curvilinear coordinates.``

  16. Advanced Cardiovascular Monitoring

    NARCIS (Netherlands)

    de Waal, E.E.C.

    2009-01-01

    The Frank-Starling curve (the curvilinear relation between cardiac output (CO) and preload) can be used for optimalization of the blood circulation and tissue oxygenation, in order to decrease morbidity and mortality in high risk surgery and critically ill patients. Measurement of CO and preload wit

  17. Annoyance from environmental noise across the lifespan

    NARCIS (Netherlands)

    Gerven, P.W.M. van; Vos, H.; Boxtel, M.P.J. van; Janssen, S.A.; Miedema, H.M.E.

    2009-01-01

    Curvilinear effects of age on self-reported annoyance from environmental noise were investigated in a pooled international and a Dutch sample of in total 62,983 individuals aged between 15 and 102 years. All respondents were frequently exposed to varying levels of transportation noise (i.e., aircraf

  18. Reverse Knowledge Transfer in MNEs

    DEFF Research Database (Denmark)

    Mudambi, Ram; Piscitello, Lucia; Rabbiosi, Larissa

    2014-01-01

    , and that the curvilinearity is greater for greenfield entries relative to acquisition entries. The U-shaped relationship between subsidiary innovativeness and reverse knowledge transfers, as well as the sensitivity of this result to entry mode are important new findings in the literature on the role of subsidiaries...

  19. Application of a Hierarchical Linear Model to the Study of Adolescent Deviance in an Overlapping Cohort Design.

    Science.gov (United States)

    Raudenbush, Stephen W.; Chan, Wing-Shing

    1993-01-01

    Used data on attitudes toward deviance during adolescence to illustrate assessment of psychometric properties of instrument for studying change, compare adequacy of linear and curvilinear growth models, control for time invariant and time-varying covariates, and link overlapping data cohorts. Findings suggest that prodeviant attitudes increased…

  20. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

    Directory of Open Access Journals (Sweden)

    Ezgi Akar

    2015-06-01

    Full Text Available Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of intervertebral disc space narrowing, sagittal alignment and range of motion (ROM using serial radiographs and magnetic resonance imaging. Results: The mean age of the 89 patients was 41.3 (24-76 years. The mean follow-up duration was 34.3 (12-64 months. Radiographic evidence of adjacent segment degeneration was observed in 12 patients (13.4%. Nine (75% patients had new complaints. Of the patients who had degenerative changes, 7 were (58% were male, 5 (42% were female; the mean age was 46 (30- 62 years. It was observed that the level of fusion and the number of fusion did not increase the adjacent segment degeneration. All of 12 patients were observed to have a non lordotic cervical spine and increased ROM. Conclusion: Development of degeneration at the level adjacent to region anterior cervical discectomy and fusion performed is higher compared to non-adjacent levels. The level of fusion and the number of fusion levels have no effect on the development of degeneration. (The Medical Bulletin of Haseki 2015; 53:120-3

  1. +Gz associated stenosis of the cervical spinal canal in fighter pilots.

    Science.gov (United States)

    Hämäläinen, O; Toivakka-Hämäläinen, S K; Kuronen, P

    1999-04-01

    Previous magnetic resonance imaging (MRI) studies have shown that repeated exposure to +Gz forces can cause premature degenerative changes of the cervical spine (i.e. a work-related disease). This paper reports on two clinical cases of +Gz-associated degenerative cervical spinal stenosis caused by dorsal osteophytes in fighter pilots. Conventional x-rays and MRI were used to demonstrate narrowing of the cervical spinal canal. The first case was complicated by a C6-7 intervertebral disk prolapse and a congenitally narrow spinal canal. The second case involved progressive degenerative spinal stenosis in the C5-6 disk space which required surgery. The findings in this case were confirmed by surgery which showed posterior osteophytes and thickened ligaments compressing the cervical medulla. These two cases suggest that +Gz forces can cause degenerative spinal stenosis of the cervical spine. Flight safety may be jeopardized if symptoms and signs of medullar compression occur during high +Gz stress. It is recommended that student fighter pilots undergo conventional x-rays and MRI studies in order to screen out and reject candidates with a congenitally narrow spinal canal. These examination methods might be useful in fighter pilots' periodic medical check-ups in order to reveal acquired degenerative spinal stenosis.

  2. Arthroscopic tibiotalar and subtalar joint arthrodesis.

    Science.gov (United States)

    Roussignol, X

    2016-02-01

    Arthroscopy has become indispensable for performing tibiotalar and subtalar arthrodesis. Now in 2015, it is the gold-standard surgical technique, and open surgery is reserved only for cases in which arthroscopy is contraindicated: material ablation after consolidation failure, osteophytes precluding a work chamber, excentric talus, severe malunion, bone defect requiring grafting, associated midfoot deformity, etc. The first reports of arthroscopic tibiotalar and subtalar arthrodesis date from the early 1990s. Consolidation rates were comparable to open surgery, but with significantly fewer postoperative complications: infection, skin necrosis, etc. Arthroscopy was for many years reserved to moderate deformity, with frontal or sagittal deviation less than 10°. The recent literature, however, seems to extend indications, the only restriction being the surgeon's experience. Tibiotalar arthrodesis on a posterior arthroscopic approach remains little used. And yet the posterior work chamber is much larger, and initial series showed consolidation rates similar to those of an anterior approach. The surgical technique for posterior tibiotalar arthrodesis was described by Van Dijk et al., initially using a posterior para-Achilles approach. This may be hampered by posterior osteophytes or ankylosis of the subtalar joint line (revision of non-consolidated arthrodesis, sequelae of calcaneal thalamus fracture) and is now used only by foot and ankle specialists. Posterior double tibiotalar-subtalar arthrodesis, described by Devos Bevernage et al., is facilitated by transplantar calcaneo-talo-tibial intramedullary nailing.

  3. Pathological phalanges in a camarasaurid sauropod dinosaur and implications on behaviour

    Directory of Open Access Journals (Sweden)

    Emanuel Tschopp

    2016-02-01

    Full Text Available Several types of pathological bony overgrowth are known from various dinosaur taxa but, except for stress fractures, are rarely reported from appendicular elements. Herein we describe pathological manual and pedal phalanges of a camarasaurid sauropod (SMA 0002, which show features rarely recognised in non-avian dinosaurs. They include lateral osteophytes and smoothing of phalangeal articular surfaces, a deep pit, proximal enthesophytes in pedal unguals, distal overgrowth associated with a fracture, and a knob-like overgrowth lateral to the distal condyles of a pedal phalanx. Their causes were assessed by means of visual examination, CT scans, and bone histology, where possible. The lateral osteophytes are interpreted as symptoms of osteoarthritis. The ossified tendon insertions in the unguals are most probably the result of prolonged, heavy use of the pedal claws, possibly for scratchdigging. The distal overgrowth is interpreted to have developed due to changed stress regimes, and to be the cause for the fracture. The deep pit represents most likely a case of osteochondrosis, whereas the knob-like overgrowth likely represents a post-traumatic phenomenon not previously reported in dinosaurs. The study confirms that a rigorous assessment of pathologies can yield information about behaviour in long-extinct animals.

  4. Micro-CT Arthrographic Analysis of Monosodium Iodoacetate- Induced Osteoarthritis in Rat Knees

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jong Won [Samsung Medical Center, Sungkyunkwan University, Seoul (Korea, Republic of); Kang, Heung Sik [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Hong, Sung Hwan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2010-10-15

    To evaluate the arthrographic findings of MIA-induced osteoarthritis in rat knees using the micro-CT arthrography. Intra-articular monosodium iodoacetate (MIA) injection-induced arthritis was induced in the right knees of twelve rats; their left knees served as the control group. Eight weeks after MIA injection, micro-CT arthrography was performed on each knee. We measured the thickness of retro-patellar cartilages, the distances of tibio-femoral joint space, subchondral bone plate thickness, tibial epiphyseal height, and transverse patellar diameter. Subchondral trabecular bone indices were measured in the tibial lateral condylar epiphysis. The data were analyzed statistically using a paired t-test. The retro-patellar articular cartilage showed thinning on the right side that had been induced to develop osteoarthritis. The right knees showed a significant reduction in the distance of the tibio-femoral joint space, prominent patellar osteophytes, and the resorption of subchondral bone. Among the subchondral trabecular bone indices, percent bone volume, and trabecular thickness was reduced on the right side. The articular cartilage thickness of MIA-induced arthritis model could be measured using micro- CT arthrography. It was possible to evaluate the osteoarthritic findings including the change in subchondral bone plate thickness, osteophyte formation, and subchondral bone resorption, as well as quantitatively analyze the trabecular bone indices.

  5. A comparative study of the detectability of TMJ radiographic techniques for artificial mandibular condylar lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hee Jeong; Jung, Yeon Hwa; Cho, Bong Hae [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Pusan National University, Pusan(Korea, Republic of)

    1997-08-15

    The purpose of this study was to evaluate the detectability of various radiographic techniques for mandibular condylar lesions. Erosive lesion, osteophyte and flattening were formed on the artificial mandibular condyle, and panoramic, transcranial, transorbital radiography, lateral and frontal tomography were taken. The results were as follows; 1. The detectability for erosive lesions was superior in the order of frontal tomography (96%), lateral tomography (78%), transorbital (59%), transcranial (56%) and panoramic (48%) radiography. 2. The location of erosive lesion that showed the highest detectability was the medial third in panoramic, the lateral third in transcranial, the central portion of anteroposterior direction in transorbital, the central portion of mediolateral direction and the posterior third in lateral tomography. Frontal tomography disclosed all erosive lesions except one anterolateral lesion. 3. The detectability of osteophyte was 100% in lateral tomography, 78% in transcranial and 56% in panoramic radiography. 4. For flattening, lateral tomography showed the flattened condyle, but both panoramic and transcranial views showed only decreased bone density without the change of condylar shape.

  6. Is there an association between a low acromion index and osteoarthritis of the shoulder?

    Science.gov (United States)

    Kircher, Jörn; Morhard, Markus; Gavriilidis, Iosif; Magosch, Petra; Lichtenberg, Sven; Habermeyer, Peter

    2010-10-01

    The aim of this study was to evaluate the relationship between a low acromion index and osteoarthritis of the shoulder. Three patient groups were used: (I) instability, n = 53; (II) calcifying tendonitis, n = 109; and (III) osteoarthritis, n = 120. Standardised digital X-rays were evaluated from the true anteroposterior and axillary views. Joint space width at three levels in each plane and the size of humeral osteophytes were measured and osteoarthritis was graded according to Samilson. The acromion index was calculated according to Nyffeler et al. (J Bone Joint Surg Am 88:800-805, 2006) in the true anteroposterior view. There were two independent investigators. Interobserver reliability was excellent for all measurements in the anteroposterior (AP) projection but inferior in the axillary projections, especially in group III. The mean acromion index was 0.64 ± 0.07 in group I, 0.64 ± 0.08 in group II and 0.73 ± 0.12 in group III. The acromion index was not correlated with the joint space width nor with the size of the osteophytes or the Samilson grading in group III. The data of the study did not show a significant association between a low acromion index and typical signs of osteoarthritis at the shoulder. The theoretical concept of a small acromion index associated with the development of osteoarthritis of the shoulder is not supported.

  7. The Relationship between Osseous Changes of the Temporomandibular Joint and RDC/TMD Groups in CBCT Images

    Directory of Open Access Journals (Sweden)

    Mahrokh Imanimoghaddam

    2014-09-01

    Full Text Available Abstract Introduction: Temporomandibular joint disorders (TMD are the most common disorders of the jaw, and despite their clinical importance, they are not completely understood. This study was aimed to evaluate the changes of temporomandibular joint (TMJ on cone beam computed tomography (CBCT images in disc displacement vs. osteoarthritis of the TMJ. Methods: In this study, 45 patients, including 37 women and 8 men (13-89 years of age, were examined. The patients were selected based on RDC/TMD criteria and group I disorders were excluded from the study. Accordingly, group II consisted of 43 joints with jaw clicking or displaced discs, and group III comprised 46 joints with crepitus. CBCT images in sagittal, coronal, and axial sections were examined to assess osseous changes in terms of flattening, sclerosis, erosion, resorption, and osteophyte formation. Data were analyzed using statistical tests including the chi-square, Mann-Whitney, and Kolmogorov-Smirnov tests with the confidence interval of 95%. Results: Mann-Whitney test for the comparison of mean age between groups II and III was not statistically significant (p value=0.06. A significant differences was found between two (RDC/TMD groups according to the prevalence of condylar erosion, resorption, and osteophyte (p

  8. How does joint remodeling work?: new insights in the molecular regulation of the architecture of joints.

    Science.gov (United States)

    Schett, Georg

    2007-01-01

    Remodeling of joints is a key feature of inflammatory and degenerative joint disease. Bone erosion, cartilage degeneration and growth of bony spurs termed osteophytes are key features of structural joint pathology in the course of arthritis, which lead to impairment of joint function. Understanding their molecular mechanisms is essential to tailor targeted therapeutic approaches to protect joint architecture from inflammatory and mechanical stress. This addendum summarizes the new insights in the molecular regulation of bone formation in the joint and its relation to bone resorption. It describes how inflammatory cytokines impair bone formation and block the repair response of joints towards inflammatory stimuli. It particularly points out the key role of Dickkopf-1 protein, a regulator of the Wingless signaling and inhibitor of bone formation. This new link between inflammation and bone formation is also crucial for explaining the generation of osteophytes, bony spurs along joints, which are characterized by new bone and cartilage formation. This mechanism is largely dependent on an activation of wingless protein signaling and can lead to complete joint fusion. This addendum summarized the current concepts of joint remodeling in the limelight of these new findings.

  9. The Influence of Magnetic Resonance Imaging Findings of Degenerative Disease on Dual-Energy X-ray Absorptiometry Measurements in Middle-Aged Men

    Energy Technology Data Exchange (ETDEWEB)

    Donescu, O.S.; Battie, M.C.; Videman, T. [Faculty of Rehabilitation Medicine and Dept. of Physical Therapy, Univ. of Alberta (Canada)

    2007-02-15

    Purpose: To examine degenerative features based on magnetic resonance imaging (MRI) measurements at the lumbar spine in relation to dual-energy X-ray absorptiometry (DXA), and to investigate whether bone mineral density (BMD) is reflected in the substitution of bone trabecular structure by fat at the vertebral body level indicated by MRI T1 relaxation time, endplate concavity, and hypertrophic (osteophytes and endplate sclerosis) MRI findings. Material and Methods: The sample for this cross-sectional study was composed of 102 subjects, 35-70 years old, from a population-based cohort. Data collection included DXA in the anterior-posterior projection at the L1-L4 vertebrae and right femoral neck, and MRI of the lumbar spine in the midsagittal plane. Results: Age, vertebral signal intensity, osteophytes, and endplate concavity collectively explained 20% of the variance in spine BMD. Conclusion: The study findings suggest that degenerative findings based on MRI measurements at the lumbar spine have an influence on bone assessment using DXA. Therefore, an overall bone assessment such as DXA might not offer an accurate measure of BMD.

  10. Characterization of Individuals with Sacroiliac Joint Bridging in a Skeletal Population: Analysis of Degenerative Changes in Spinal Vertebrae

    Directory of Open Access Journals (Sweden)

    Takeshi Imamura

    2014-01-01

    Full Text Available The aim of this study was to characterize the individuals with sacroiliac joint bridging (SIB by analyzing the degenerative changes in their whole vertebral column and comparing them with the controls. A total of 291 modern Japanese male skeletons, with an average age at death of 60.8 years, were examined macroscopically. They were divided into two groups: individuals with SIB and those without bridging (Non-SIB. The degenerative changes in their whole vertebral column were evaluated, and marginal osteophyte scores (MOS of the vertebral bodies and degenerative joint scores in zygapophyseal joints were calculated. SIB was recognized in 30 individuals from a total of 291 males (10.3%. The average of age at death in SIB group was significantly higher than that in Non-SIB group. The values of MOS in the thoracic spines, particularly in the anterior part of the vertebral bodies, were consecutively higher in SIB group than in Non-SIB group. Incidence of fused vertebral bodies intervertebral levels was obviously higher in SIB group than in Non-SIB group. SIB and marginal osteophyte formation in vertebral bodies could coexist in a skeletal population of men. Some systemic factors might act on these degenerative changes simultaneously both in sacroiliac joint and in vertebral column.

  11. The aging process in the sacroiliac joint. Helical computed tomography analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Yasuaki; Shirai, Yasumasa; Miyamoto, Masabumi [Nippon Medical School, Tokyo (Japan)

    2002-07-01

    The purpose of this study was to compare the frequency of degenerative changes in the sacroiliac joint by age, sex, laterality, body mass index, and childbearing experience, based on computed tomography (CT) images obtained from the lower back of symptom-free subjects in different age groups. These data were used to trace the development of the sacroiliac joint until the occurrence of osteoarthritis with aging. CT transverse and coronal images were examined for the presence of the following degenerative signs: joint space narrowing, sclerosis, osteophytes, cysts, and erosion. The results indicated that joint degeneration begins in the 20s and tends to progress with age. Each form of degeneration was markedly more frequent in the 40s or older, and some type of degeneration was observed in the joints of all subjects aged 50 years or older. In terms of the localization of the joint degeneration, sclerosis was common on the upper and middle anterior of the articular surface of the ilium, osteophytes were common on the anterior surface of the sacrum. Degeneration had progressed further in women than in men in every age group, and tended to progress faster in parous than in nulliparous women, It was presumed that the birth of the first child, rather than subsequent births had the greatest effect on the sacroiliac joint. (author)

  12. Measurement of pharyngeal sensory cortical processing: technique and physiologic implications

    Directory of Open Access Journals (Sweden)

    Ringelstein E Bernd

    2009-07-01

    Full Text Available Abstract Background Dysphagia is a major complication of different diseases affecting both the central and peripheral nervous system. Pharyngeal sensory impairment is one of the main features of neurogenic dysphagia. Therefore an objective technique to examine the cortical processing of pharyngeal sensory input would be a helpful diagnostic tool in this context. We developed a simple paradigm to perform pneumatic stimulation to both sides of the pharyngeal wall. Whole-head MEG was employed to study changes in cortical activation during this pharyngeal stimulation in nine healthy subjects. Data were analyzed by means of synthetic aperture magnetometry (SAM and the group analysis of individual SAM data was performed using a permutation test. Results Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation. Conclusion The method introduced here is simple and easy to perform and might be applicable in the clinical setting. The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing. They might also explain changes in deglutition after hemispheric strokes. The ipsilaterally lateralized processing is surprising and needs further investigation.

  13. Efferent and afferent connections of the olfactory bulb and prepiriform cortex in the pigeon (Columba livia).

    Science.gov (United States)

    Atoji, Yasuro; Wild, J Martin

    2014-06-01

    Although olfaction in birds is known to be involved in a variety of behaviors, there is comparatively little detailed information on the olfactory brain. In the pigeon brain, the olfactory bulb (OB) is known to project to the prepiriform cortex (CPP), piriform cortex (CPi), and dorsolateral corticoid area (CDL), which together are called the olfactory pallium, but centrifugal pathways to the OB have not been fully explored. Fiber connections of CPi and CDL have been reported, but those of other olfactory pallial nuclei remain unknown. The present study examines the fiber connections of OB and CPP in pigeons to provide a more detailed picture of their connections using tract-tracing methods. When anterograde and retrograde tracers were injected in OB, projections to a more extensive olfactory pallium were revealed, including the anterior olfactory nucleus, CPP, densocellular part of the hyperpallium, tenia tecta, hippocampal continuation, CPi, and CDL. OB projected commissural fibers to the contralateral OB but did not receive afferents from the contralateral olfactory pallium. When tracers were injected in CPP, reciprocal ipsilateral connections with OB and nuclei of the olfactory pallium were observed, and CPP projected to the caudolateral nidopallium and the limbic system, including the hippocampal formation, septum, lateral hypothalamic nucleus, and lateral mammillary nucleus. These results show that the connections of OB have a wider distribution throughout the olfactory pallium than previously thought and that CPP provides a centrifugal projection to the OB and acts as a relay station to the limbic system.

  14. Connectivity and neurochemistry of the commissura anterior of the pigeon (Columba livia).

    Science.gov (United States)

    Letzner, Sara; Simon, Annika; Güntürkün, Onur

    2016-02-01

    The anterior commissure (AC) and the much smaller hippocampal commissure constitute the only interhemispheric pathways at the telencephalic level in birds. Since the degeneration study from Zeier and Karten (), no detailed description of the topographic organization of the AC has been performed. This information is not only necessary for a better understanding of interhemispheric transfer in birds, but also for a comparative analysis of the evolution of commissural systems in the vertebrate classes. We therefore examined the fiber connections of the AC by using choleratoxin subunit B (CTB) and biotinylated dextran amine (BDA). Injections into subareas of the arcopallium and posterior amygdala (PoA) demonstrated contralateral projection fields within the anterior arcopallium (AA), intermediate arcopallium (AI), PoA, lateral, caudolateral and central nidopallium, dorsal and ventral mesopallium, and medial striatum (MSt). Interestingly, only arcopallial and amygdaloid projections were reciprocally organized, and all AC projections originated within a rather small area of the arcopallium and the PoA. The commissural neurons were not GABA-positive, and thus possibly not of an inhibitory nature. In sum, our neuroanatomical study demonstrates that a small group of arcopallial and amygdaloid neurons constitute a wide range of contralateral projections to sensorimotor and limbic structures. Different from mammals, in birds the neurons that project via the AC constitute mostly heterotopically organized and unidirectional connections. In addition, the great majority of pallial areas do not participate by themselves in interhemispheric exchange in birds. Instead, commissural exchange rests on a rather small arcopallial and amygdaloid cluster of neurons.

  15. Anatomic Considerations on the Middle Ear in Dog

    Directory of Open Access Journals (Sweden)

    Carmen Berghes

    2010-05-01

    Full Text Available Purpose of this study is to explain some aspects of middle ear anatomy in dog. The study was conducted on five dog skulls (different ages from common, large size dogs. The skulls were processed by maceration and submitted to a treatment of mechanical cleaning with perhydrol. The temporal bone was collected first; the external wall was opened carefully to study the tympanic cavity. The ossicles were collected separately and subsequently described. From research carried promontory appears as an elongated projection that separates the oval window and round window. Vestibular window is oval or slightly ovoid shape of a hole, located dorso-medially to the promontory, which communicates with the middle ear vestibule. Cochlearia window appears as a round or circular hole located caudo-lateral to the promontory . it is blocked by a membrane called the tympanum secondary, cavity separating the ramp of the snail. In the ventro-oral cavity openings ductus faringo tympanicum. The osicules sound represented by hammer, anvil and stirrup are articulated with each other and form a chain as a link between the eardrum and vestibular window. Bones are driven by two muscles: the tensor muscle and muscle stirrup eardrum is very thin. osicules ear are relatively large and resemble those of humans. Lenticular bone is the lenticular process of the long arm of anvile.

  16. Functional morphology of venous structures associated with the male and female reproductive systems in Florida manatees (Trichechus manatus latirostris).

    Science.gov (United States)

    Rommel, S A; Pabst, D A; McLellan, W A

    2001-12-01

    The reproductive organs of Florida manatees (Trichechus manatus latirostris) are surrounded by thermogenic locomotory muscles and insulating fat. Manatees are reported to maintain core body temperatures of 35.6 degrees -36.4 degrees C, temperatures known to interfere with production and maturation of viable sperm in terrestrial mammals. We describe two novel venous plexuses associated with the manatee epididymis. Each epididymis is located in a hypogastric fossa at the caudolateral extremity of the abdominal cavity. Each hypogastric fossa is lined by an inguinal venous plexus that receives cooled blood from a superficial thoracocaudal plexus. We conclude that male manatees may prevent hyperthermic insult to their reproductive tissues by feeding cooled superficial blood to venous plexuses deep within their bodies. Female manatees also possess hypogastric fossae and venous structures similar to those found in male manatees. The ovaries, uterine tubes, and distal tips of the uterine horns are located in the hypogastric fossae. We suggest that the thermovascular structures we describe also prevent hypothermic insult to female manatee reproductive tissues. The venous structures in manatees are functionally similar to structures associated with reproductive thermoregulation in cetaceans and phocid seals. Thus, these thermovascular structures appear to be convergent morphological adaptations that occur in three clades of diving mammals with independent evolutionary histories.

  17. Detailed Anatomy of the Cranial Cervical Ganglion in the Dromedary Camel (Camelus dromedarius).

    Science.gov (United States)

    Nourinezhad, Jamal; Mazaheri, Yazdan; Biglari, Zahra

    2015-08-01

    The detailed morphology and topography of the cranial cervical ganglion (CCG) with its surrounding structures were studied in 10 sides of five heads of adult one-humped camel to determine its general arrangement as well as its differences and similarities to other animals. The following detailed descriptions were obtained: (1) the bilateral CCG was constantly present caudal to cranial base at the rostroventral border of the occipital condyle over the caudolateral part of nasopharynx; (2) the CCG was always in close relations medially with the longus capitis muscle, rostrolaterally with the internal carotid artery, and caudally with the vagus nerve; and (3) the branches of the CCG were the internal carotid and external carotid nerves, jugular nerve, cervical interganglionic branch, laryngopharyngeal branch, carotid sinus branch and communicating branches to the vagus, and first spinal nerves. In conclusion, there was no variation regarding topography of dromedary CCG among the specimens, in spite of typical variations in number, and mainly in origin of nerve branches ramifying from the CCG. In comparative anatomy aspect, the close constant relations, and presence of major nerves (internal/external carotid and jugular nerves) of dromedary CCG exhibited a typical reported animal's pattern. However, the shape, structures lateral to the CCG, the origin and course pattern of external carotid and jugular nerves, the number of the major nerves branches, the communicating branches of the CCG to the spinal and cranial nerves, and the separation of most rostral parts of vagosympathetic trunk of dromedary were different from those of most reported animals.

  18. A songbird forebrain area potentially involved in auditory discrimination and memory formation

    Indian Academy of Sciences (India)

    Raphael Pinaud; Thomas A Terleph

    2008-03-01

    Songbirds rely on auditory processing of natural communication signals for a number of social behaviors, including mate selection, individual recognition and the rare behavior of vocal learning – the ability to learn vocalizations through imitation of an adult model, rather than by instinct. Like mammals, songbirds possess a set of interconnected ascending and descending auditory brain pathways that process acoustic information and that are presumably involved in the perceptual processing of vocal communication signals. Most auditory areas studied to date are located in the caudomedial forebrain of the songbird and include the thalamo-recipient field L (subfields L1, L2 and L3), the caudomedial and caudolateral mesopallium (CMM and CLM, respectively) and the caudomedial nidopallium (NCM). This review focuses on NCM, an auditory area previously proposed to be analogous to parts of the primary auditory cortex in mammals. Stimulation of songbirds with auditory stimuli drives vigorous electrophysiological responses and the expression of several activity-regulated genes in NCM. Interestingly, NCM neurons are tuned to species-specific songs and undergo some forms of experience-dependent plasticity in-vivo. These activity-dependent changes may underlie long-term modifications in the functional performance of NCM and constitute a potential neural substrate for auditory discrimination. We end this review by discussing evidence that suggests that NCM may be a site of auditory memory formation and/or storage.

  19. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Horng, Annie; Stockinger, M.; Notohamiprodjo, M. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Raya, J.G. [New York University Langone Medical Center, Center for Biomedical Imaging, New York, NY (United States); Pietschmann, M. [Ludwig-Maximilians-University Hospital Munich, Department of Orthopedic Surgery, Munich (Germany); Hoehne-Hueckstaedt, U.; Glitsch, U.; Ellegast, R. [Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin (Germany); Hering, K.G. [Miner' s Hospital, Department of Diagnostic Radiology, Dortmund (Germany); Glaser, C. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); RZM Zentrum, Munich (Germany)

    2015-06-01

    To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. (orig.)

  20. К определению напряженного состояния около криволинейного отверстия в трансверсально-изотропной сферической оболочке On determination of stress state around a curvilinear hole in transversely isotropic spherical shell

    Directory of Open Access Journals (Sweden)

    Лунь Е. И.

    1973-12-01

    Full Text Available В настоящей статье рассматривается задача об определении напряженного состояния в трансверсально-изотропной сферической оболочке с криволинейным отверстием.

  1. Mini-rhexis for white intumescent cataracts

    Directory of Open Access Journals (Sweden)

    Newton Kara-Junior

    2009-04-01

    Full Text Available PURPOSE: To compare the intraoperative safety of two techniques of capsulorhexis for intumescent white cataracts: traditional one-stage continuous curvilinear capsulorhexis and two-stage continuous curvilinear capsulorhexis. METHODS: This prospective comparative randomized study included two groups: the 1-CCC group (11 patients received traditional one-stage continuous curvilinear capsulorhexis with 5-6 mm diameter, and the 2-CCC (13 patients group received a deliberately small continuous curvilinear capsulorhexis that was secondarily enlarged, or a two-stage continuous curvilinear capsulorhexis. Patients were stratified according to cataract subset, which was characterized echographically. Six patients were considered as type 1, fifteen as type 2 and three as type 3. Type 1 included intumescent white cataracts with cortex liquefaction and extensive internal acoustic reflections, type 2 included white cataracts with voluminous nuclei, a small amount of whitish solid cortex, and minimal internal acoustic reflections, and type 3 included white cataracts with fibrous anterior capsules and few internal echo spikes. RESULTS: With the one-stage technique, 46.15% of patients had leakage of the liquefied cortex; in addition, the surgeon perceived high intracapsular pressure in 61.53% of cases. Anterior capsule tears occurred in 23.07% of cases, discontinuity of capsulorhexis in 30.79% of cases and no posterior capsular rupture occurred. With the two-stage technique, leakage of the liquefied cortex occurred in 45.45% of cases; additionally, the surgeon perceived high intracapsular pressure in 36.36% of cases. No anterior capsule tears, discontinuity of capsulorhexis or posterior capsular rupture occurred. Considering each cataract subset, there was a higher incidence of leakage for type 2 as compared to types 1 and 3. CONCLUSIONS: Two-stage continuous curvilinear capsulorhexis helps prevent unexpected radial tears of the initial capsulotomy from high

  2. Trapezial topography in thumb carpometacarpal arthritis.

    Science.gov (United States)

    Van Nortwick, Sarah; Berger, Aaron; Cheng, Robert; Lee, Julia; Ladd, Amy L

    2013-08-01

    Objective Contradictory reported arthritic patterns of the metacarpal surface of the trapezium include preferential volar wear, radial wear, and dorsal-ulnar sparing. We investigated whether a predominant wear pattern exists in surgical trapeziectomy for advanced thumb carpometacarpal (CMC) arthritis. Methods We examined 36 intact trapezia from 34 thumb CMC arthroplasty patients over an 18-month period. The first metacarpal articular surface revealed three consistent morphology patterns: (1) saddle, (2) dish, and (3) cirque. The saddle represented cartilage loss with preservation of the normal trapezial morphology. The dish shape represented concave curvature, with loss of the normal saddle configuration. The cirque shape represented preferential volar concave wear, disrupting the convex volardorsal arc. Two surgeons classified the randomized specimens twice, blinded to patient identity and each other's categorization. Radiographic Eaton staging was correlated retrospectively for 35 of 36 of the trapezial specimens. Eight specimens were further quantified with micro-computed tomography (micro-CT). Results Thirty-six trapezia were classified as follows: 17 (47%) saddle, 12 (33%) dish, and 7 (19%) cirque. Intra-rater reliability was 0.97 and 0.95; inter-rater reliability in the second round was 0.95. The 36 trapezia represented 27 female (75%) and 9 male (25%) patients; 18 (50%) represented the dominant hand. Age at surgery averaged 64 (33-76). Complete cartilage loss of the entire metacarpal surface was seen in 15 (42%) of all specimens. Osteophyte presence was typically minimal in the saddle group; the dish group had characteristic extensive rimming osteophytes in a 91% female population (11/12), and the cirque group had volar osteophytes. Radiographic severity ranged from Eaton stage II to IV; less severe radiographic staging (Eaton II) predominated in the saddle configuration; advanced Eaton III-IV disease predominated in both cirque and dish shapes. Micro

  3. Abnormalities of the axial and proximal appendicular skeleton in adults with Laron syndrome (growth hormone insensitivity)

    Energy Technology Data Exchange (ETDEWEB)

    Kornreich, L.; Konen, O.; Schwarz, M.; Horev, G. [Schneider Children' s Medical Center of Israel, Imaging Department, Petah Tiqwa (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Siegel, Y. [Rabin Medical Center, Imaging Department, Petah Tiqwa (Israel); Jackson Memorial Hospital, Department of Radiology, Thoracic Section, Miami, FL (United States); Hershkovitz, I. [Tel Aviv University, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv (Israel); Laron, Z. [Schneider Children' s Medical Center of Israel, Endocrinology and Diabetes Research Unit, Petah Tiqwa (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel)

    2008-02-15

    To investigate abnormalities in the skeleton (with the exclusion of the skull, cervical spine, hands and feet) in patients with Laron syndrome, who have an inborn growth hormone resistance and congenital insulin-like growth factor-1 (IGF-1) deficiency. The study group was composed of 15 untreated patients with Laron syndrome (seven male and eight female) aged 21-68 years. Plain films of the axial and appendicular skeleton were evaluated retrospectively for abnormalities in structure and shape. The cortical width of the long bones was evaluated qualitatively and quantitatively (in the upper humerus and mid-femur), and the cortical index was calculated and compared with published references. Measurements were taken of the mid-anteroposterior and cranio-caudal diameters of the vertebral body and spinous process at L3, the interpedicular distance at L1 and L5, and the sacral slope. Thoracic and lumbar osteophytes were graded on a 5-point scale. Values were compared with a control group of 20 healthy persons matched for age. The skeleton appeared small in all patients. No signs of osteopenia were visible. The cortex of the long bones appeared thick in the upper limbs in 11 patients and in the lower limbs in four. Compared with the reference values, the cortical width was thicker than average in the humerus and thinner in the femur. The vertebral diameters at L3 and the interpedicular distances at L1 and L5 were significantly smaller in the patients than in the control subjects (P < 0.001); however, at L5 the canal was wider, relative to the vertebral body. The study group had a higher rate of anterior osteophytes in the lumbar spine than the controls had, and their osteophytes were also significantly larger. In the six patients for whom radiographs of the upper extremity in its entirety were available on one film, the ulna appeared to be rotated. In one 22-year-old man, multiple epiphyses were still open. Congenital IGF-1 deficiency leads to skeletal abnormalities

  4. Differentiating Pneumothorax from the Common Radiographic Skinfold Artifact.

    Science.gov (United States)

    Kattea, M Obadah; Lababede, Omar

    2015-06-01

    Pneumothorax can be a critical medical condition. The radiographic curvilinear appearance of pneumothorax can be mimicked by a skinfold artifact. Radiographic differentiation of the two entities is achieved in most cases by careful analysis of the characteristics of the linear shadow and its course. A thin, sharply defined opaque density representing the visceral pleura is the hallmark of pneumothorax. The added density of a skinfold presents as a broad opacity, which is outlined laterally by a sharply defined lucent line as a result of the Mach band effect and adjacent air. Unlike pneumothorax, a skinfold produces a line that does not follow the expected course of visceral pleura. Additional features, such as the absence of increased lucency laterally and the projection of lung markings across the curvilinear shadow, can help in the correct identification of skinfolds. Repeating the chest radiograph or using other imaging modalities can be considered in difficult cases.

  5. Geometric Separation by Single-Pass Alternating Thresholding

    CERN Document Server

    Kutyniok, Gitta

    2012-01-01

    Modern data is customarily of multimodal nature, and analysis tasks typically require separation into the single components. Although a highly ill-posed problem, the morphological difference of these components sometimes allow a very precise separation such as, for instance, in neurobiological imaging a separation into spines (pointlike structures) and dendrites (curvilinear structures). Recently, applied harmonic analysis introduced powerful methodologies to achieve this task, exploiting specifically designed representation systems in which the components are sparsely representable, combined with either performing $\\ell_1$ minimization or thresholding on the combined dictionary. In this paper we provide a thorough theoretical study of the separation of a distributional model situation of point- and curvilinear singularities exploiting a surprisingly simple single-pass alternating thresholding method applied to the two complementary frames: wavelets and curvelets. Utilizing the fact that the coefficients are ...

  6. A computational formulation for constrained solid and liquid membranes considering isogeometric finite elements

    CERN Document Server

    Sauer, Roger A; Corbett, Callum J

    2012-01-01

    A geometrically exact membrane formulation is presented that is based on curvilinear coordinates and isogeometric finite elements, and is suitable for both solid and liquid membranes. The curvilinear coordinate system is used to describe both the theory and the finite element equations of the membrane. In the latter case this avoids the use of local cartesian coordinates at the element level. Consequently, no transformation of derivatives is required. The formulation considers a split of the in-plane and out-of-plane membrane contributions, which allows the construction of a stable formulation for liquid membranes with constant surface tension. The proposed membrane formulation is general, and accounts for dead and live loading, as well as enclosed volume, area, and contact constraints. The new formulation is illustrated by several challenging examples, considering linear and quadratic Lagrange elements, as well as isogeometric elements based on quadratic NURBS and cubic T-splines. It is seen that the isogeom...

  7. Some consonants sound curvy: effects of sound symbolism on object recognition.

    Science.gov (United States)

    Aveyard, Mark E

    2012-01-01

    Two experiments explored the influence of consonant sound symbolism on object recognition. In Experiment 1, participants heard a word ostensibly from a foreign language (in reality, a pseudoword) followed by two objects on screen: a rectilinear object and a curvilinear object. The task involved judging which of the two objects was properly described by the unknown pseudoword. The results showed that congruent sound-symbolic pseudoword-object pairs produced higher task accuracy over three rounds of testing than did incongruent pairs, despite the fact that "hard" pseudowords (with three plosives) and "soft" pseudowords (with three nonplosives) were paired equally with rectilinear and curvilinear objects. Experiment 2 reduced awareness of the manipulation by including similar-shaped, target-related distractors. Sound symbolism effects still emerged, though the time course of these effects over three rounds differed from that in Experiment 1.

  8. Coupled mixed-field laminate theory and finite element for smart piezoelectric composite shell structures

    Science.gov (United States)

    Saravanos, Dimitris A.

    1996-01-01

    Mechanics for the analysis of laminated composite shells with piezoelectric actuators and sensors are presented. A new mixed-field laminate theory for piezoelectric shells is formulated in curvilinear coordinates which combines single-layer assumptions for the displacements and a layerwise representation for the electric potential. The resultant coupled governing equations for curvilinear piezoelectric laminates are described. Structural mechanics are subsequently developed and an 8-node finite-element is formulated for the static and dynamic analysis of adaptive composite structures of general laminations containing piezoelectric layers. Evaluations of the method and comparisons with reported results are presented for laminated piezoelectric-composite plates, a closed cylindrical shell with a continuous piezoceramic layer and a laminated composite semi-circular cantilever shell with discrete cylindrical piezoelectric actuators and/or sensors.

  9. Concreteness and Psychological Distance in Natural Language Use.

    Science.gov (United States)

    Snefjella, Bryor; Kuperman, Victor

    2015-09-01

    Existing evidence shows that more abstract mental representations are formed and more abstract language is used to characterize phenomena that are more distant from the self. Yet the precise form of the functional relationship between distance and linguistic abstractness is unknown. In four studies, we tested whether more abstract language is used in textual references to more geographically distant cities (Study 1), time points further into the past or future (Study 2), references to more socially distant people (Study 3), and references to a specific topic (Study 4). Using millions of linguistic productions from thousands of social-media users, we determined that linguistic concreteness is a curvilinear function of the logarithm of distance, and we discuss psychological underpinnings of the mathematical properties of this relationship. We also demonstrated that gradient curvilinear effects of geographic and temporal distance on concreteness are nearly identical, which suggests uniformity in representation of abstractness along multiple dimensions.

  10. CPIC: A Parallel Particle-In-Cell Code for Studying Spacecraft Charging

    Science.gov (United States)

    Meierbachtol, Collin; Delzanno, Gian Luca; Moulton, David; Vernon, Louis

    2015-11-01

    CPIC is a three-dimensional electrostatic particle-in-cell code designed for use with curvilinear meshes. One of its primary objectives is to aid in studying spacecraft charging in the magnetosphere. CPIC maintains near-optimal computational performance and scaling thanks to a mapped logical mesh field solver, and a hybrid physical-logical space particle mover (avoiding the need to track particles). CPIC is written for parallel execution, utilizing a combination of both OpenMP threading and MPI distributed memory. New capabilities are being actively developed and added to CPIC, including the ability to handle multi-block curvilinear mesh structures. Verification results comparing CPIC to analytic test problems will be provided. Particular emphasis will be placed on the charging and shielding of a sphere-in-plasma system. Simulated charging results of representative spacecraft geometries will also be presented. Finally, its performance capabilities will be demonstrated through parallel scaling data.

  11. Efficient analysis of dielectric radomes using multilevel fast multipole algorithm with CRWG basis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A full-wave analysis of the electromagnetic problem of a three-dimensional (3-D) antenna radiating through a 3-D dielectric radome is preserued.The problem is formulated using the Poggio-Miller-Chang-Harrington-Wu(PMCHW) approach for homogeneous dielectric objects and the electric field integral equation for conducting objects.The integral equations are discretized by the method of moment (MoM),in which the conducting and dielectric surface/interfaces are represented by curvilinear triangular patches and the unknown equivalent electric and magnetic currents are expanded using curvilinear RWG basis functions.The resultant matrix equation is then solved by the multilevel fast multipole algorithm (MLFMA) and fast far-field approximation (FAFFA) is used to further accelerate the computation.The radiation patterns of dipole arrays in the presence of radomes are presented.The numerical results demonstrate the accuracy and versatility of this method.

  12. Moving grids for magnetic reconnection via Newton-Krylov methods

    KAUST Repository

    Yuan, Xuefei

    2011-01-01

    This paper presents a set of computationally efficient, adaptive grids for magnetic reconnection phenomenon where the current density can develop large gradients in the reconnection region. Four-field extended MagnetoHydroDynamics (MHD) equations with hyperviscosity terms are transformed so that the curvilinear coordinates replace the Cartesian coordinates as the independent variables, and moving grids\\' velocities are also considered in this transformed system as a part of interpolating the physical solutions from the old grid to the new grid as time advances. The curvilinear coordinates derived from the current density through the Monge-Kantorovich (MK) optimization approach help to reduce the resolution requirements during the computation. © 2010 Elsevier B.V. All rights reserved.

  13. Impact of contour on aesthetic judgments and approach-avoidance decisions in architecture

    DEFF Research Database (Denmark)

    Vartanian, Oshin; Navarrete, Gorka; Chatterjee, Anjan;

    2013-01-01

    On average, we urban dwellers spend about 90% of our time indoors, and share the intuition that the physical features of the places we live and work in influence how we feel and act. However, there is surprisingly little research on how architecture impacts behavior, much less on how it influences......, participants were more likely to judge spaces as beautiful if they were curvilinear than rectilinear. Neuroanatomically, when contemplating beauty, curvilinear contour activated the anterior cingulate cortex exclusively, a region strongly responsive to the reward properties and emotional salience of objects....... Complementing this finding, pleasantness—the valence dimension of the affect circumplex—accounted for nearly 60% of the variance in beauty ratings. Furthermore, activation in a distributed brain network known to underlie the aesthetic evaluation of different types of visual stimuli covaried with beauty ratings...

  14. Analytical description of stationary ideal MHD flows with constant total pressure

    Energy Technology Data Exchange (ETDEWEB)

    Golovin, Sergey V., E-mail: sergey@hydro.nsc.r [Lavrentyev Institute of Hydrodynamics SB RAS, 630090 Novosibirsk (Russian Federation); Department of Mechanics and Mathematics, Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

    2010-02-01

    Incompressible stationary flows of ideal plasma are studied. By introduction of curvilinear system of coordinates in which streamlines and magnetic force lines form a family of coordinate surfaces, MHD equations are partially integrated and brought to a certain convenient form. It is demonstrated that the admissible group of Bogoyavlenskij's symmetry transformations (Bogoyavlenskij, 2001 ) performs as a scaling transformation (the scaling factor is an arbitrary function of one variable) for the curvilinear coordinates. Analytic description of stationary flows with constant total pressure is given. It is shown, that contact magnetic surfaces of such flows are translational surfaces, i.e. are swept out by translating one curve rigidly along another curve. Examples of solutions with constant total pressure possessing an arbitrariness in one function of two variables and three functions of one variable are given.

  15. Performance Analyses of IDEAL Algorithm on Highly Skewed Grid System

    Directory of Open Access Journals (Sweden)

    Dongliang Sun

    2014-03-01

    Full Text Available IDEAL is an efficient segregated algorithm for the fluid flow and heat transfer problems. This algorithm has now been extended to the 3D nonorthogonal curvilinear coordinates. Highly skewed grids in the nonorthogonal curvilinear coordinates can decrease the convergence rate and deteriorate the calculating stability. In this study, the feasibility of the IDEAL algorithm on highly skewed grid system is analyzed by investigating the lid-driven flow in the inclined cavity. It can be concluded that the IDEAL algorithm is more robust and more efficient than the traditional SIMPLER algorithm, especially for the highly skewed and fine grid system. For example, at θ = 5° and grid number = 70 × 70 × 70, the convergence rate of the IDEAL algorithm is 6.3 times faster than that of the SIMPLER algorithm, and the IDEAL algorithm can converge almost at any time step multiple.

  16. Decelerating the diminishing returns of citizenship on task performance: the role of social context and interpersonal skill.

    Science.gov (United States)

    Ellington, J Kemp; Dierdorff, Erich C; Rubin, Robert S

    2014-07-01

    Recent scholarship on citizenship behavior demonstrates that engaging too often in these behaviors comes at the expense of task performance. In order to examine the boundary conditions of this relationship, we used resource allocation and social exchange theories to build predictions regarding moderators of the curvilinear association between citizenship and task performance. We conducted a field study of 366 employees, in which we examined the relationship between the frequency of interpersonal helping behavior and task performance and tested for the moderating influences of 3 social context features (social density, interdependence, and social support) and of employees' levels of interpersonal skill. Results provided corroborating evidence of the diminishing returns between citizenship and task performance. Further, these diminishing returns were decelerated when contexts were characterized by high interdependence and social density and when employees possessed strong interpersonal skills. Implications for extending future citizenship theory and research to incorporate curvilinearity are presented.

  17. Pressure Distribution in a Porous Squeeze Film Bearing Lubricated with a Herschel-Bulkley Fluid

    Directory of Open Access Journals (Sweden)

    Walicka A.

    2016-12-01

    Full Text Available The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated with a lubricant being a viscoplastic fluid of a Herschel-Bulkley type is considered. After general considerations on the flow of the viscoplastic fluid (lubricant in a bearing clearance and in a porous layer the modified Reynolds equation for the curvilinear squeeze film bearing with a Herschel-Bulkley lubricant is given. The solution of this equation is obtained by a method of successive approximation. As a result one obtains a formula expressing the pressure distribution. The example of squeeze films in a step bearing (modeled by two parallel disks is discussed in detail.

  18. DG-FEM solution for nonlinear wave-structure interaction using Boussinesq-type equations

    DEFF Research Database (Denmark)

    Engsig-Karup, Allan Peter; Hesthaven, Jan; Bingham, Harry B.

    2008-01-01

    equations in complex and curvilinear geometries which amends the application range of previous numerical models that have been based on structured Cartesian grids. The Boussinesq method provides the basis for the accurate description of fully nonlinear and dispersive water waves in both shallow and deep...... considerations combined with a mirror principle, it is possible to impose weak slip boundary conditions for both structured and general curvilinear wall boundaries while maintaining the accuracy of the scheme. As is standard for current high-order Boussinesq-type models, arbitrary waves can be generated...... waters within the breaking limit. To demonstrate the current applicability of the model both linear and mildly nonlinear test cases are considered in two horizontal dimensions where the water waves interact with bottom-mounted fully reflecting structures. It is established that, by simple symmetry...

  19. Three-Dimensional Exact Free Vibration Analysis of Spherical, Cylindrical, and Flat One-Layered Panels

    Directory of Open Access Journals (Sweden)

    Salvatore Brischetto

    2014-01-01

    equilibrium written in orthogonal curvilinear coordinates for the free vibrations of simply supported structures. These equations consider an exact geometry for shells without simplifications. The main novelty is the possibility of a general formulation for different geometries. The equations written in general orthogonal curvilinear coordinates allow the analysis of spherical shell panels and they automatically degenerate into cylindrical shell panel, cylindrical closed shell, and plate cases. Results are proposed for isotropic and orthotropic structures. An exhaustive overview is given of the vibration modes for a number of thickness ratios, imposed wave numbers, geometries, embedded materials, and angles of orthotropy. These results can also be used as reference solutions to validate two-dimensional models for plates and shells in both analytical and numerical form (e.g., closed solutions, finite element method, differential quadrature method, and global collocation method.

  20. Efficient Computation of N-S Equation with Free Surface Flow Around an ACV on ShirazUCFD Grid

    Science.gov (United States)

    Sheikhalishahi, Seyyed Mehdi; Alizadehrad, Davood; Dastghaibyfard, Gholamhossein; Alishahi, Mohammad Mehdi; Nikseresht, Amir Hossein

    This paper presents the application of a parallel high accuracy simulation code for Incompressible Navier-Stokes solution with free surface flow around an ACV (Air Cushion Vehicle) on ShirazUCFD Grid environment. The parallel finite volume code is developed for incompressible Navier-Stokes solver on general curvilinear coordinates system for modeling free surface flows. A single set of dimensionless equations is derived to handle both liquid and air phases in viscous incompressible free surface flow in general curvilinear coordinates. The volume of fluid (VOF) method with lagrangian propagation in computational domain for modeling the free surface flow is implemented. The parallelization approach uses a domain decomposition method for the subdivision of the numerical grid, the SPMD program model and MPICH-G2 as the message passing environment is used to obtain a portable application.

  1. SIMULATION OF STRONG TURBULENCE FLOW WITH FREE SURFACE INCLUDING THE EFFECTS OF STREAMLINE CURVATURE

    Institute of Scientific and Technical Information of China (English)

    DAI Hui-chao; LIU Yu-ling; WEI Wen-li

    2005-01-01

    This paper is concerned with a mathematical model for two-dimensional strong turbulence flow with free surface including the effects of streamline curvature in orthogonal curvilinear coordinate system, with which the characteristics of the turbulence flow field on the ogee spillway was numerical simulated. In the numerical simulation, the flow control equations in orthogonal curvilinear coordinate system were discretized by the finite volume method, the physical parameters( P, U,V,K,ε,γt,etc.) were arranged on a staggered grid, the discretized equations were solved with the SIMPLEC method, and the complex free surface was dealt with VOF method. The computed results show that the velocity fields, pressure field, shear stress distribution and kinetic energy of turbulent flow on the ogee spillway are in agreement with experimental data. This confirms that the model can be used for numerical simulation of the turbulence flow on ogee spillway.

  2. Re-entry vehicle shape for enhanced performance

    Science.gov (United States)

    Brown, James L. (Inventor); Garcia, Joseph A. (Inventor); Prabhu, Dinesh K. (Inventor)

    2008-01-01

    A convex shell structure for enhanced aerodynamic performance and/or reduced heat transfer requirements for a space vehicle that re-enters an atmosphere. The structure has a fore-body, an aft-body, a longitudinal axis and a transverse cross sectional shape, projected on a plane containing the longitudinal axis, that includes: first and second linear segments, smoothly joined at a first end of each the first and second linear segments to an end of a third linear segment by respective first and second curvilinear segments; and a fourth linear segment, joined to a second end of each of the first and second segments by curvilinear segments, including first and second ellipses having unequal ellipse parameters. The cross sectional shape is non-symmetric about the longitudinal axis. The fourth linear segment can be replaced by a sum of one or more polynomials, trigonometric functions or other functions satisfying certain constraints.

  3. Dissolvable films of silk fibroin for ultrathin conformal bio-integrated electronics.

    Science.gov (United States)

    Kim, Dae-Hyeong; Viventi, Jonathan; Amsden, Jason J; Xiao, Jianliang; Vigeland, Leif; Kim, Yun-Soung; Blanco, Justin A; Panilaitis, Bruce; Frechette, Eric S; Contreras, Diego; Kaplan, David L; Omenetto, Fiorenzo G; Huang, Yonggang; Hwang, Keh-Chih; Zakin, Mitchell R; Litt, Brian; Rogers, John A

    2010-06-01

    Electronics that are capable of intimate, non-invasive integration with the soft, curvilinear surfaces of biological tissues offer important opportunities for diagnosing and treating disease and for improving brain/machine interfaces. This article describes a material strategy for a type of bio-interfaced system that relies on ultrathin electronics supported by bioresorbable substrates of silk fibroin. Mounting such devices on tissue and then allowing the silk to dissolve and resorb initiates a spontaneous, conformal wrapping process driven by capillary forces at the biotic/abiotic interface. Specialized mesh designs and ultrathin forms for the electronics ensure minimal stresses on the tissue and highly conformal coverage, even for complex curvilinear surfaces, as confirmed by experimental and theoretical studies. In vivo, neural mapping experiments on feline animal models illustrate one mode of use for this class of technology. These concepts provide new capabilities for implantable and surgical devices.

  4. Vitrectorhexis versus forceps posterior capsulorhexis in pediatric cataract surgery

    Directory of Open Access Journals (Sweden)

    Lav Kochgaway

    2013-01-01

    Full Text Available This study was done to compare the results of posterior continuous curvilinear capsulorhexis created using forceps with those created using vitrector in eyes suffering from congenital cataract. Vitrectorhexis term was first used by Wilson et al in 1999. [1] Fifty eyes with congenital and developmental cataract were included in this study. The posterior capsulorhexis was created using utrata forceps in 17 eyes or through a vitrector in 33 eyes. Forceps capsulorhexis was performed before IOL implantation, while vitrectorhexis was performed after IOL implantation in the bag. The results of both the surgery were compared using the following criteria: incidence of extension of rhexis, ability to achieve posterior rhexis of appropriate size, ability to implant the IOL in the bag, the surgical time, and learning curve. Vitrectorhexis after IOL implantation was an easy to learn alternative to manual posterior continuous curvilinear capsulorhexis in pediatric cataract surgery. It was more predictable and reproducible, with a short learning curve and lesser surgical time.

  5. Relationships between vegetation indices, radiation absorption, and net photosynthesis evaluated by a sensitivity analysis

    Science.gov (United States)

    Choudhury, Bhaskar J.

    1987-01-01

    A two-stream approximation to the radiative-transfer equation is used to calculate the vegetation indices (simple ratio and normalized difference), the fraction of incident photosynthetically active radiation (PAR) absorbed by the canopy, and the daily mean canopy net photosynthesis under clear-sky conditions. The model calculations are tested against field observations over wheat, cotton, corn, and soybean. The relationships between the vegetation indices and radiation absorption or net photosynthesis are generally found to be curvilinear, and changes in the soil reflectance affected these relationships. The curvilinearity of the relationship between normalized differences and PAR absorption decreases as the magnitude of soil reflectance increases. The vegetation indices might provide the fractional radiation absorption with some a priori knowledge about soil reflectance. The relationship between the vegetation indices and net photosynthesis must be distinguished for C3 and C4 crops. Effects of spatial heterogeneity are discussed.

  6. Widespread Occurrence of Trenching Patterns in the Granulation Field: Evidence for Roll Convection?

    CERN Document Server

    Getling, A V

    2007-01-01

    Time-averaged series of granulation images are analysed using COLIBRI, a purpose-adapted version of a code originally developed to detect straight or curvilinear features in aerospace images. The algorithm of image processing utilises a nonparametric statistical criterion that identifies a straight-line segment as a linear feature (lineament) if the photospheric brightness at a certain distance from this line is on both sides stochastically lower or higher than at the line itself. Curvilinear features can be detected as chains of lineaments, using a criterion modified in some way. Once the input parameters used by the algorithm are properly adjusted, the algorithm highlights ``ridges'' and ``trenches'' in the relief of the brightness field, drawing white and dark lanes. The most remarkable property of the trenching patterns is a nearly-universally-present parallelism of ridges and trenches. Since the material upflows are brighter than the downflows, the alternating parallel light and dark lanes should reflect...

  7. The Money Buffer Effect in China: A Higher Income Cannot Make You Much Happier but Might Allow You to Worry Less.

    Science.gov (United States)

    Li, Bin; Li, Aimei; Wang, Xiaotian; Hou, Yunsong

    2016-01-01

    This study examined the possibility that there is a curvilinear relationship between income and subjective well-being in China. This study also investigated whether this curvilinear relationship is moderated by social class and mediated by respondents' material affluence. The study was conducted in China, and the sample consisted of 900 blue-collar workers and 546 white-collar workers. The results for emotional well-being showed that income significantly predicted negative affect but not positive affect. This finding indicates that in China, high incomes may not make people happier but might allow them to worry less, which we call the "money buffer effect." The results also showed that material affluence mediates the interaction effect between income and social class on subjective well-being. The implications of these results for future research and practice are discussed.

  8. Unusual Thymic Hyperplasia Mimicking Lipomatous Tumor in an Eight-Year-Old Boy with Concomitant Pericardial Lipomatosis and Right Facial Hemihypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoo Jin; Kim Woo Sun; Cheon, Jung Eun; Lim, Yun Jung; Kim, In One; Yeon, Kyung Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Kyeong Cheon; Byun, Sun Ju [Seoul National University Hospital, Seoul (Korea, Republic of)

    2011-06-15

    We report a case of thymic hyperplasia accompanied by pericardial lipomatosis and right facial hemihypertrophy in an 8-year-old boy. On imaging studies, the hyperplastic thymus had prominent curvilinear and nodular fatty areas simulating a fat-containing anterior mediastinal mass, which is an unusual finding in children. To our knowledge, this is the first report on a child with a combination of thymic hyperplasia, pericardial lipomatosis, and right facial hemihypertrophy. The radiologic findings are presented with a brief discussion.

  9. Methodology for a Regional Tidal Model Evaluation, With Application to Central California

    Science.gov (United States)

    2009-01-01

    moorings off Pt Sur and the AOSN moorings; Gary Egbert and Lana Erofeeva (OSU) for | roviding tidal solutions for the West Coast; and Paul Martin...rotated into the ICON curvilinear coordinates according to Paul Martin’s scheme (personal comm.). The transport component orthogonal to the open... Ekman balance in the California Current. Journal of Geophysical Research 100. 18261-18269. Chereskin. T.K.. Morris. M.Y., Niiler, P.P., Kosro, P.M

  10. Capsulorhexis: Pearls and pitfalls

    OpenAIRE

    Mohammadpour, Mehrdad; Erfanian, Reza; Karimi, Nasser

    2011-01-01

    A critical step in phacoemulsification (as well as extracapsular cataract extraction) is making a window in anterior capsule wall (i.e. anterior capsulotomy). Continuous Curvilinear Capsulorhexis (CCC) has become recognized as the standard method of anterior capsulectomy. Techniques employed for CCC have undergone sustained evolution. The present review evaluates elementary principles of CCC. Management of CCC in the presence of small pupil and pseudoexfoliation syndrome is discussed. Main di...

  11. Algorithm development for Maxwell's equations for computational electromagnetism

    Science.gov (United States)

    Goorjian, Peter M.

    1990-01-01

    A new algorithm has been developed for solving Maxwell's equations for the electromagnetic field. It solves the equations in the time domain with central, finite differences. The time advancement is performed implicitly, using an alternating direction implicit procedure. The space discretization is performed with finite volumes, using curvilinear coordinates with electromagnetic components along those directions. Sample calculations are presented of scattering from a metal pin, a square and a circle to demonstrate the capabilities of the new algorithm.

  12. Calcifications of the Thoracic Aorta on Extended Non-Contrast-Enhanced Cardiac CT

    OpenAIRE

    Damian Craiem; Gilles Chironi; Casciaro, Mariano E.; Sebastian Graf; Alain Simon

    2014-01-01

    BACKGROUND: The presence of calcified atherosclerosis in different vascular beds has been associated with a higher risk of mortality. Thoracic aorta calcium (TAC) can be assessed from computed tomography (CT) scans, originally aimed at coronary artery calcium (CAC) assessment. CAC screening improves cardiovascular risk prediction, beyond standard risk assessment, whereas TAC performance remains controversial. However, the curvilinear portion of the thoracic aorta (TA), that includes the aorti...

  13. DNA-SMART: Biopatterned Polymer Film Microchannels for Selective Immobilization of Proteins and Cells.

    Science.gov (United States)

    Schneider, Ann-Kathrin; Nikolov, Pavel M; Giselbrecht, Stefan; Niemeyer, Christof M

    2017-02-22

    A novel SMART module, dubbed "DNA-SMART" (DNA substrate modification and replication by thermoforming) is reported, where polymer films are premodified with single-stranded DNA capture strands, microthermoformed into 3D structures, and postmodified with complementary DNA-protein conjugates to realize complex biologically active surfaces within microfluidic devices. As a proof of feasibility, it is demonstrated that microchannels presenting three different proteins on their inner curvilinear surface can be used for selective capture of cells under flow conditions.

  14. PROBE OF CONVOY LORRY’S ROADABILITY ON MODEL WITH FOUR FREEDOM DEGREES

    Directory of Open Access Journals (Sweden)

    M. Dyachuk

    2009-01-01

    Full Text Available The modeling of curvilinear movement of the lorry convoy is considered. The mathematical model of movement of two links flat system is developed; the software in the language of technical computing MATLAB is created; results of movement modeling on an example of jointed structure MAZ-643008 + NEFAZ-96931 taking into account distribution of steered wheels rotation angles and elastic properties of tires of wheels are analyzed.

  15. Archaeological Investigations in the Gainesville Lake Area of the Tennessee-Tombigbee Waterway. Volume V. Archaeology of the Gainesville Lake Area: Synthesis.

    Science.gov (United States)

    1982-09-01

    consist of chevrons, chevron filled triangles, diamonds formed by cross hatching, hexagons, and lines incised parallel to the rim. Curvilinear design...platform in Mound 3, a miniature Marksville Incised var. Markaville vessel was found next to a crematory pit. Markville Incised var. Harkavilie has been...All of the excavated Pharr Mounds date to the middle Miller I Pharr subphase. Mound A at the Pharr site is a conical mound with a central crematory

  16. Gullies and Lobate Deposits as Geomorphological Evidence for Impact-induced Transient Water Flow and Localized, Buried Ice-bearing Deposits on Vesta.

    Science.gov (United States)

    Scully, J. E. C.; Russell, C. T.; Yin, A.; Jaumann, R.; Carey, E. M.; McSween, H. Y., Jr.; Castillo, J. C.; Raymond, C. A.; Reddy, V.; Le Corre, L.

    2014-12-01

    Vesta, the second most massive asteroid, has long been perceived as anhydrous. However, recent studies suggesting the localized presence of hydrated minerals and past sub-surface water have challenged this perception (e.g. Sarafian et al., 2013; De Sanctis et al., 2012; Prettyman et al., 2012; McCord et al. 2012; Reddy et al. 2012; Treiman et al, 2004). Herein we show evidence that transient water flowed on the surface, in a debris-flow-like process, and left distinctive geomorphologic features. Based on analysis of ~20 m/ pixel images obtained by Dawn, we identify a class of locally occurring, interconnected and curvilinear systems of gullies in the walls of young (< 100s Ma) impact craters, ending in lobate deposits near the crater floors. As curvilinear systems only occur within impact craters, we propose that they formed by a particulate-dominated transient flow of water (≤ 26 minutes) that was released from buried ice-bearing deposits by impact-induced heating. Our interpretation is in accordance with the occurrence of pitted terrain on lobate deposits and crater floors. Pitted terrain is interpreted to result from the degassing of volatiles (Denevi et al., 2012). We also identify linear gully systems, which are morphologically distinct from the curvilinear systems, and are interpreted to form by dry flow of material. Craters containing curvilinear systems are clustered in two regions of Vesta's surface, whereas linear systems are evenly distributed. This indicates that the proposed buried ice-bearing deposits are likely localized in extent. Together with the newly expanded understanding of the distribution and behavior of water in the asteroid belt (e.g. Küppers et al., 2014; Hsieh & Jewitt, 2006), our results support the new paradigm that there is a continuum of small bodies in the solar system with many intermediate states of hydration. The varied hydrologic processes that occur within this new paradigm suggest the evolution of our solar system is more

  17. Ultrathin, Stretchable, Multiplexing pH Sensor Arrays on Biomedical Devices With Demonstrations on Rabbit and Human Hearts Undergoing Ischemia

    OpenAIRE

    Chung, Hyun-Joong; Sulkin, Matthew S.; Kim, Jong-Seon; Goudeseune, Camille; Chao, Hsin-Yun; Song, Joseph W.; Yang, Sang Yoon; Hsu, Yung-Yu; Ghaffari, Roozbeh; Efimov, Igor R.; Rogers, John A.

    2013-01-01

    Stable pH is an established biomarker of health, relevant to all tissues of the body, including the heart. Clinical monitoring of pH in a practical manner, with high spatiotemporal resolution, is particularly difficult in organs such as the heart due to its soft mechanics, curvilinear geometry, heterogeneous surfaces and continuous, complex rhythmic motion. The results presented here illustrate that advanced strategies in materials assembly and electrochemical growth can yield interconnected ...

  18. Nomography

    CERN Document Server

    Otto, Edward

    1963-01-01

    Nomography deals with geometrical transformations, particularly projective transformations of a plane. The book reviews projective plane and collineation transformations in geometrical and algebraical terms. The geometrical approach aims at permitting the use of elementary geometrical methods in drawing collineation nomograms consisting of three rectilinear scales. The algebraical treatment concerns nomograms containing curvilinear scales. The text explains functional scales that include the graph of a function and a logarithmic scale. The book explores equations which can be represented by el

  19. Element-Partition-Based Methods for Visualization of 3D Unstructured Grid Data

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Element-partition-based methods for visualization of 3D unstructured grid data are presented.First,partition schemes for common elements,including curvilinear tetrahedra,pentahedra,hexahedra,etc.,are given,so that complex elements can be divided into several rectilinear tetrahedra,and the visualization processes can be simplified.Then,a slice method for cloud map and an iso-surface method based on the partition schemes are described.

  20. Adjustment of State Owned and Foreign-Funded Enterprises in China to economic reforms,1980s-2007: a logistic smooth transition regression (LSTR) approach

    OpenAIRE

    Aizenman, Joshua; Geng, Nan

    2009-01-01

    This paper applies a logistic smooth transition regression approach to the estimation of a homogenous aggregate value added production function of the State Owned (SOE) and Foreign-Funded Enterprises (FFE) in China, 1980s-2007. The transition associated with the eco- nomic reforms in China is estimated applying a curvilinear logistic function, where the speed and the timing of the transition are endoge- nously determined by the data. We find high but gradually declining markups in both ...

  1. Advantages of Diffuse Light for Horticultural Production and Perspectives for Further Research

    OpenAIRE

    Tao eLi; Qichang eYang

    2015-01-01

    Plants use diffuse light more efficiently than direct light, which is well established due to diffuse light penetrates deeper into the canopy and photosynthetic rate of a single leaf shows a curvilinear response to the light flux density. Diffuse light also results in a more even horizontal and temporal light distribution in the canopy, which plays substantial role for crop photosynthesis enhancement as well as production improvement under diffuse light. Here we cover some of the recent findi...

  2. Formas, cultura técnica y expresión arquitectónica

    OpenAIRE

    Jordá Such, Cármen

    2016-01-01

    [EN] The development of reinforced concrete techniques and the appearance of a hitherto unknown typology, shells, propitiated a surprising transformation of the modern canon, whose critical assessment needs to be updated from new interpretive hypotheses. The exuberant and curvilinear architectural work of the mid-20th century is explained in this article from the perspective of engineering that had experimented with strength contribution to form. Later, the ideas of architecture, structure an...

  3. Swimming Performance of Bighead Carp and Silver Carp: Methodology, Metrics, and Management Applications

    Science.gov (United States)

    2012-08-01

    the Laurentian Great Lakes? A bioenergetic modeling exercise. Freshwater Biology 55: 2138-2152. Cornish, M., J. Crossland, L. Nelson, J. Pothoff...tubs, half- to three-quarters full, circulated with a Little Giant Water Wizard Model 5 MSP submersible water pump, filtered with a 200-L canister...tions. Endurance data are analyzed using regression models that describe linear or curvilinear relationships between water velocity (independent or

  4. Is Mathematical Anxiety Always Bad for Math Learning: The Role of Math Motivation

    OpenAIRE

    Wang, Zhe; Lukowski, Sarah L.; Hart, Sara Ann; Lyons, Ian M.; Thompson, Lee A.; Kovas, Yulia; Mazzocco, Michèle M.; Plomin, Robert; Petrill, Stephen A.

    2015-01-01

    The linear relations between math anxiety and math cognition have been frequently studied. However, the relations between anxiety and performance on complex cognitive tasks have been repeatedly demonstrated to follow a curvilinear fashion. Given the lack of attention to the possibility of such complex interplay between emotion and cognition in the math learning literature, the current study aimed to address this gap via exploring the relations between math anxiety, math motivation, and math c...

  5. CLIPPERS-like MRI findings in a patient with multiple sclerosis.

    Science.gov (United States)

    Ferreira, R M; Machado, G; Souza, A S; Lin, K; Corrêa-Neto, Y

    2013-04-15

    Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) has been described as a clinically and radiologically distinct pontine-predominant encephalomyelitis with a favorable response to high dose corticosteroids and usually requiring chronic immunosuppresive therapy. Brain magnetic resonance imaging (MRI) reveals a characteristic pattern of punctate and curvilinear enhancement lesions in the pons extending variably to surrounding areas. We herein describe such imaging findings in a patient with a definite diagnosis of relapsing-remitting multiple sclerosis (MS).

  6. Large-Eddy Simulation of the Tip-Flow of a Rotor in Hover

    Science.gov (United States)

    2005-10-28

    circular cylinder with a 548 358 10× × grid. On the Pentium Beowulf cluster which has a gigabit interconnect between the nodes, we achieve about a 63...The simulations have been carried out on seven processors of the Beowulf clusters . This simulation has been carried out as a LES and figure 7(b...validation cases. Note that although the grid is curvilinear and allows us to cluster more grid points in the boundary layer, the grid does not exactly

  7. The Effect of Quantity, Quality and Timing of Headquarters-Initiated Knowledge Flows on Subsidiary Performance

    DEFF Research Database (Denmark)

    Tran, Yen; Mahnke, Volker; Ambos, Björn

    2010-01-01

    This paper develops and tests a model that explains how the quality, quantity and timing of knowledge flows from headquarters influence subsidiary performance. It extends recent research on vertical knowledge flows between global headquarters and international subsidiaries. We find a positive...... quality/performance relationship and a curvilinear quantity/performance relationship, indicating that too much knowledge sharing can be detrimental to the receiving subsidiary. Most importantly, we show that the timing of a knowledge flow significantly affects subsidiary sales performance....

  8. Exploratory data analysis with Matlab

    CERN Document Server

    Martinez, Wendy L; Solka, Jeffrey

    2010-01-01

    Since the publication of the bestselling first edition, many advances have been made in exploratory data analysis (EDA). Covering innovative approaches for dimensionality reduction, clustering, and visualization, Exploratory Data Analysis with MATLAB®, Second Edition uses numerous examples and applications to show how the methods are used in practice.New to the Second EditionDiscussions of nonnegative matrix factorization, linear discriminant analysis, curvilinear component analysis, independent component analysis, and smoothing splinesAn expanded set of methods for estimating the intrinsic di

  9. Thin-Film Metamaterials called Sculptured Thin Films

    CERN Document Server

    Lakhtakia, Akhlesh

    2010-01-01

    Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.

  10. Delaunay triangulation and computational fluid dynamics meshes

    Science.gov (United States)

    Posenau, Mary-Anne K.; Mount, David M.

    1992-01-01

    In aerospace computational fluid dynamics (CFD) calculations, the Delaunay triangulation of suitable quadrilateral meshes can lead to unsuitable triangulated meshes. Here, we present case studies which illustrate the limitations of using structured grid generation methods which produce points in a curvilinear coordinate system for subsequent triangulations for CFD applications. We discuss conditions under which meshes of quadrilateral elements may not produce a Delaunay triangulation suitable for CFD calculations, particularly with regard to high aspect ratio, skewed quadrilateral elements.

  11. The relation between conscientiousness, empowerment and performance

    Directory of Open Access Journals (Sweden)

    Riëtte Sutherland

    2007-02-01

    Full Text Available This study examined the relationship between conscientiousness, empowerment and job performance among information technology professionals. An Employee Empowerment Questionnaire (EEQ, a Conscientiousness Scale and a Social Desirability Scale were administered to 101 information technology customer service engineers. Managers completed a Performance Evaluation Questionnaire (PEQ for each customer service engineer. The results indicated a significant relationship between conscientiousness and empowerment. A curvilinear relationship was found between empowerment and performance. The practical and theoretical implications of the findings are discussed.

  12. An analysis of curvature effects for the control of wall-bounded shear flows

    Science.gov (United States)

    Gatski, T. B.; Savill, A. M.

    1989-01-01

    The Reynolds stress transport equations are used to predict the effects of simultaneous and sequential combinations of distortions on turbulent boundary layers. The equations are written in general orthogonal curvilinear coordinates, with the curvature terms expressed in terms of the principal radii of curvature of the respective coordinate surfaces. Results are obtained for the cases of two-dimensional and three-dimensional flows in the limit where production and pressure-strain redistribution dominate over diffusion effects.

  13. Numerical Methods Using B-Splines

    Science.gov (United States)

    Shariff, Karim; Merriam, Marshal (Technical Monitor)

    1997-01-01

    The seminar will discuss (1) The current range of applications for which B-spline schemes may be appropriate (2) The property of high-resolution and the relationship between B-spline and compact schemes (3) Comparison between finite-element, Hermite finite element and B-spline schemes (4) Mesh embedding using B-splines (5) A method for the incompressible Navier-Stokes equations in curvilinear coordinates using divergence-free expansions.

  14. A Huygens Surface Approach to Antenna Implementation in Near-Field Radar Imaging System Simulations

    Science.gov (United States)

    2015-08-01

    critical geometrical details; re- casting the FDTD update equations on a grid conformal to a curvilinear coordinate system (e.g., cylindrical); and...Imaging System Simulations by Traian Dogaru and DaHan Liao Approved for public release; distribution unlimited...A Huygens Surface Approach to Antenna Implementation in Near-Field Radar Imaging System Simulations by Traian Dogaru and DaHan Liao Sensors

  15. Doubly Periodic Cracks in the Anisotropic Medium with the Account of Contact of Their Faces

    Directory of Open Access Journals (Sweden)

    Maksymovych Olesya

    2014-09-01

    Full Text Available The paper presents complex variable integral formulae and singular boundary integral equations for doubly periodic cracks in anisotropic elastic medium. It utilizes the numerical solution procedure, which accounts for the contact of crack faces and produce accurate results for SIF evaluation. It is shown that the account of contact effects significantly influence the SIF of doubly periodic curvilinear cracks both for isotropic and anisotropic materials.

  16. APPLICATIONS OF FRACTIONAL EXTERIOR DIFFERENTIAL IN THREE-DIMENSIONAL SPACE

    Institute of Scientific and Technical Information of China (English)

    陈勇; 闫振亚; 张鸿庆

    2003-01-01

    A brief survey of fractional calculus and fractional differential forms was firstly given. The fractional exterior transition to curvilinear coordinate at the origin were discussed and the two coordinate transformations for the fractional differentials for three-dimensional Cartesian coordinates to spherical and cylindrical coordinates are obtained, respectively. In particular, for v = m = 1 , the usual exterior transformations, between the spherical coordinate and Cartesian coordinate, as well as the cylindrical coordinate and Cartesian coordinate, are found respectively, from fractional exterior transformation.

  17. Implicit finite difference methods on composite grids

    Science.gov (United States)

    Mastin, C. Wayne

    1987-01-01

    Techniques for eliminating time lags in the implicit finite-difference solution of partial differential equations are investigated analytically, with a focus on transient fluid dynamics problems on overlapping multicomponent grids. The fundamental principles of the approach are explained, and the method is shown to be applicable to both rectangular and curvilinear grids. Numerical results for sample problems are compared with exact solutions in graphs, and good agreement is demonstrated.

  18. Mathematical Methods for Optical Physics and Engineering

    Science.gov (United States)

    Gbur, Gregory J.

    2011-01-01

    1. Vector algebra; 2. Vector calculus; 3. Vector calculus in curvilinear coordinate systems; 4. Matrices and linear algebra; 5. Advanced matrix techniques and tensors; 6. Distributions; 7. Infinite series; 8. Fourier series; 9. Complex analysis; 10. Advanced complex analysis; 11. Fourier transforms; 12. Other integral transforms; 13. Discrete transforms; 14. Ordinary differential equations; 15. Partial differential equations; 16. Bessel functions; 17. Legendre functions and spherical harmonics; 18. Orthogonal functions; 19. Green's functions; 20. The calculus of variations; 21. Asymptotic techniques; Appendices; References; Index.

  19. Analysis of Buried Dielectric Objects Using Higher-Order MoM for Volume Integral Equations

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

    2004-01-01

    A higher-order method of moments (MoM) is applied to solve a volume integral equation for dielectric objects in layered media. In comparison to low-order methods, the higher-order MoM, which is based on higher-order hierarchical Legendre vector basis functions and curvilinear hexahedral elements......, requires considerably less number of unknowns and multilayer Green's function calculations for an accurate solution....

  20. The degenerative spine: pattern recognition and guidelines to image interpretation.

    Science.gov (United States)

    Parizel, P M; Van Hoyweghen, A J L; Bali, A; Van Goethem, J; Van Den Hauwe, L

    2016-01-01

    Degenerative disease of the spine, in the form of intervertebral disc degeneration and bony growth, causing osteophytes and impinging upon the spinal canal and neural foramina, is the most frequent disorder affecting the spine. In this chapter we first discuss briefly the indications for computed tomography or magnetic resonance imaging in suspected degenerative spine disease. We then describe changes of disc height, signal intensity, and disc contour with aging and repeated microtrauma, as well as the imaging techniques most appropriate to image them. A grading system for lumbar disc changes is provided. Stenosis of the canal and neural foramina is reviewed next, concluding with a description of degenerative changes affecting the vertebral endplates and bone marrow.

  1. Crowned odontoid process and osteoarthrosis of the anterior atlantoaxial joint

    Energy Technology Data Exchange (ETDEWEB)

    Skaane, P.; Klott, K.J.

    1981-01-01

    Crowned odontoid process and osteoarthrosis of the anterior atlantoaxial joint. The so-called peridentale aureole ( crowned odontoid ), a horseshoelike calcification around the odontoid process, can occasionally be shown on transbuccal views of the occipito-atlantoaxial region, but is commonly only seen on a.p. tomography in patients with osteoarthrosis of the anterior atlantoxial joint. Tomographic examinations reveal that these irregular horseshoe-like calcifications around the odontoid peg represent mainly the osteophyte formation on the superior border of the anterior arch of the atlas. These calcifications are often surrounding a smaller calcification on the tip of the odontoid peg sometimes with a bucket-handle appearance corresponding to the ostephyte formation on the odontoid process. The peridentale aureole or crowned odontoid process is easily overlooked unless tomography is performed, and misinterpretations are possible if the radiologist is not familiar with this appearance of osteoarthrosis and some other joint diseases of the anterior atlantoaxial joint.

  2. Osteoid osteoma simulating an osteocartilaginous exostosis

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, A.; Giacomini, S.; Bianchi, G.; Pellacani, A.; Mercuri, M. [Rizzoli Orthopedic Institute, University of Bologna, Via Pupilli 1, 40127, Bologna (Italy); Bertoni, F. [Pathology Department, Rizzoli Orthopedic Institute, University of Bologna (Italy)

    2004-03-01

    We describe a case of osteoid osteoma in the tibia of a 3-year-old patient who presented with a clinical and radiographic picture that suggested an exostosis. The formation of osteoid osteoma with a radiographic picture similar to that of osteophytes or exostosis has been previously documented only rarely. The authors hypothesize that the exostosis-like formation observed was actually the calcification of soft tissues that formed after the intense periosteal inflammatory reaction caused by the osteoid osteoma. As a result of its peculiar clinical and radiographic presentation, diagnosis of this lesion was delayed. Being located close to the medial growth plate of the tibia, it caused lengthening of the limb with a pronounced valgus deviation of the knee. An excisional biopsy provided histological evidence, clinical resolution and immediate pain relief, but incomplete resolution of the valgus deformity of the knee. (orig.)

  3. Cervical spondylosis anatomy: pathophysiology and biomechanics.

    Science.gov (United States)

    Shedid, Daniel; Benzel, Edward C

    2007-01-01

    Cervical spondylosis is the most common progressive disorder in the aging cervical spine. It results from the process of degeneration of the intervertebral discs and facet joints of the cervical spine. Biomechanically, the disc and the facets are the connecting structures between the vertebrae for the transmission of external forces. They also facilitate cervical spine mobility. Symptoms related to myelopathy and radiculopathy are caused by the formation of osteophytes, which compromise the diameter of the spinal canal. This compromise may also be partially developmental. The developmental process, together with the degenerative process, may cause mechanical pressure on the spinal cord at one or multiple levels. This pressure may produce direct neurological damage or ischemic changes and, thus, lead to spinal cord disturbances. A thorough understanding of the biomechanics, the pathology, the clinical presentation, the radiological evaluation, as well as the surgical indications of cervical spondylosis, is essential for the management of patients with cervical spondylosis.

  4. Forestier’s disease with complete spinal involvement

    Directory of Open Access Journals (Sweden)

    Ankur Nandan Varshney

    2013-04-01

    Full Text Available A 70-year-old diabetic and hypertensive male patient visited our clinic with complaints of non-inflammatory back pain since two years. He was heavy built with a BMI of 29 kg/m2. Physical examination revealed limitation of flexion, extension, and lateral flexion of lumbar spine. X-ray of spine revealed flowing calcification of anterior longitudinal ligaments from cervical to lumbar spine with claw osteophytes giving rise to characteristic ‘Melting Wax’ appearance (Panel A: fig A- cervical anteroposterior (AP, fig B- cervical lateral , fig C- lumbar AP , fig D- lumbar lateral (Panel B: fig E- thoracolumbar AP, fig F- thoracolumbar lateral. Sacroiliac joints were normal (Panel A: fig C- white arrow. The diagnosis was diffuse idiopathic skeletal hyperostosis (DISH or Forestier’s disease and symptomatic treatment was initiated.

  5. [The appearances of chondropathia patellae on plain films (author's transl)].

    Science.gov (United States)

    Schumacher, K A; Glöckler, W T; Mutschler, W; Rittmeyer, K

    1979-12-01

    The ability to diagnose chondropathia patellae on plain radiographs was studied in 64 patients in whom the disease had been confirmed either by operation or arthroscopy. All cases of stage III chondropathia were diagnosable by radiological examination; in stage I, 67%, and in stage II, 73% could be diagnosed. The diagnosis depends on the co-existence of marginal irregularities, irregularities of the subchondral bone lamellae, spotty diffuse demineralisation, marginal osteophytes, irregularities at the insertion of the quadriceps tendon and soft tissue changes such as joint effusions. These changes are best identified on the so-called "defilée" view. Disalignment of the axis of the patella and post-traumatic defects are of particular importance for the development of chondropathia, but in the present clinical material, the existence of dysplasia of the patella or of the femoral condyle was not associated with a demonstrable increase of chondromalacia.

  6. Elbow arthroscopy.

    Science.gov (United States)

    Dodson, Christopher C; Nho, Shane J; Williams, Riley J; Altchek, David W

    2008-10-01

    Arthroscopy of the elbow was originally considered to be an unsafe procedure because of the small size of the elbow joint capsule and its proximity to several crucial neurovascular structures. Over the past decade, however, the procedure has become safer and more effective. These improvements can be attributed to a better understanding of elbow anatomy and of the disorders about the elbow as well as to advances in arthroscopic equipment and surgical technique. The most common indications for elbow arthroscopy include removal of loose bodies, synovectomy, débridement and/or excision of osteophytes, capsular release, and the assessment and treatment of osteochondritis dissecans. More recent advances have expanded the indications of elbow arthroscopy to include fracture management (eg, radial head fractures) and the treatment of lateral epicondylitis.

  7. Comparison of acetabular reamings during hip resurfacing versus uncemented total hip arthroplasty.

    LENUS (Irish Health Repository)

    Brennan, S A

    2009-04-01

    PURPOSE: To compare the quantity of bone removed from the acetabulum during resurfacing hip arthroplasty versus uncemented total hip arthroplasty (THA). METHODS: 62 consecutive patients with osteoarthritis of the hip were prospectively studied. 24 men and 7 women aged 40 to 86 (mean, 59) years underwent Birmingham hip resurfacing. 13 men and 18 women aged 34 to 88 (mean, 61) years underwent uncemented THA using the trident acetabular cup. Obese elderly women at risk of femoral neck fracture and patients with large subchondral pseudocysts or a history of avascular necrosis of the femoral head were assigned to uncemented THA. Acetabular reamings were collected; marginal osteophytes were not included. The reamings were dehydrated, defatted, and weighed. RESULTS: The mean weight of acetabular reamings was not significantly different between patients undergoing hip resurfacing and uncemented THA (p=0.57). CONCLUSION: In hip resurfacing, the use of an appropriately small femoral component avoids oversizing the acetabular component and removal of excessive bone stock.

  8. A tomographic study of positional and bony changes in the temporomandibular joint following orthognathic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Song, Nam Kyu; Kim Min Suk; Koh, Kwang Joon [Dept. of Oral Radiology, College of Dentistry, Chonpook National University, Chonju (Korea, Republic of)

    1992-08-15

    The purpose of this study was to aid in the evaluation of prognosis of temporomandibular joint following orthognathic surgery. For this study, 20 patients (40 TMJ) who undergone orthognathic surgery were examined. Preoperative and postoperative tomograms of TMJ were taken. And the subjects were divided into 3 groups according to postoperative periods. The obtained results were as follows : 1. There were no significant differences between preoperative and postoperative changes in joint spaces in each group and between groups (P<0.05). 2. There were no significant differences between preoperative and postoperative ratio of joint spaces (P<0.05).3. There were no significant differences between preoperative and postoperative changes in the range of motion of condylar head (P<0.05). 4. The bony changes of condylar head were observed in 14 (35%) condyles (6 erosion, 2 flattening, 5 double contour, 1 osteophyte).

  9. Chondrocalcinosis of the wrist.

    Science.gov (United States)

    Saffar, P

    2004-10-01

    Calcium Pyrophosphate Dihydrate Deposition (CPDD) disease has characteristic radiographic features including soft tissue calcification, joint space narrowing, bone sclerosis, subchondral cyst formation without osteophyte formation, and large intraosseous geodes. Triangular fibrocartilage calcification is frequently found and isolated scapho-trapezio-trapezoid (STT) arthritis is specific for CPDD. Distal radio-ulnar (DRUJ), isolated midcarpal joint and piso-triquetral joint involvement also occur. 127 patients were reviewed. Seventy-eight had symptomatic STT joint arthritis, for which 36 underwent surgery. Twenty-two patients had a SLAC wrist deformity for which ten underwent surgery. Eight patients had isolated midcarpal arthritis for which three midcarpal arthrodeses, two four-bone arthrodeses and two carpal tunnel releases were performed. Nineteen patients had a generalized arthritis and seven of the patients underwent surgery: four-corner arthrodesis+scaphoidectomy (one case), carpal tunnel release (two cases) extensor synovectomy (two cases) and trigger finger release (two cases).

  10. Hip osteoarthritis: What the radiologist wants to know

    Energy Technology Data Exchange (ETDEWEB)

    Karachalios, Theofilos [Department of Orthopaedic Surgery, School of Health Sciences, University of Thessaly, Papakiriazi 22, Larissa 41222 (Greece)]. E-mail: kar@med.uth.gr; Karantanas, Apostolos H. [Department of Radiology, Medical School, University of Crete, Heraklion (Greece); Malizos, Konstantinos [Department of Orthopaedic Surgery, School of Health Sciences, University of Thessaly, Papakiriazi 22, Larissa 41222 (Greece)

    2007-07-15

    Osteoarthritis (OA) is the most common disease of the hip joint seen in adults. The diagnosis of OA is based on a combination of radiographic findings of joint degeneration and characteristic subjective symptoms. The lack of a radiographic consensus definition has resulted in a variation of the published incidences and prevalence of OA. The chronological sequence of degeneration includes the following plain radiographic findings: joint space narrowing, development of osteophytes, subchondral sclerosis, and cyst formation. There are cases though, that plain radiographs show minor changes and the clinical suspicion of early disease can be confirmed with more sophisticated imaging methods, such as multi-detector computed tomography and MR imaging. The present article will review all the clinical information on the hip OA together with an updated radiological approach, with emphasis on the early depiction and the differential diagnosis of the disease.

  11. Glenohumeral Joint Preservation: A Review of Management Options for Young, Active Patients with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Olivier A. van der Meijden

    2012-01-01

    Full Text Available The management of osteoarthritis of the shoulder in young, active patients is a challenge, and the optimal treatment has yet to be completely established. Many of these patients wish to maintain a high level of activity, and arthroplasty may not be a practical treatment option. It is these patients who may be excellent candidates for joint-preservation procedures in an effort to avoid or delay joint replacement. Several palliative and restorative techniques are currently optional. Joint debridement has shown good results and a combination of arthroscopic debridement with a capsular release, humeral osteoplasty, and transcapsular axillary nerve decompression seems promising when humeral osteophytes are present. Currently, microfracture seems the most studied reparative treatment modality available. Other techniques, such as autologous chondrocyte implantation and osteochondral transfers, have reportedly shown potential but are currently mainly still investigational procedures. This paper gives an overview of the currently available joint preserving surgical techniques for glenohumeral osteoarthritis.

  12. Surgical Correction of Patellar Luxation in a Rabbit

    Directory of Open Access Journals (Sweden)

    J. Riggs

    2013-01-01

    Full Text Available A two-and-a-half-year-old giant lop-eared rabbit, weighing 5.1 kg, presented with a one-month history of intermittent right hind limb lameness. The limb locked in extension during hopping. On examination, a grade-2 medial patellar luxation of the right hind was diagnosed, with associated stifle joint swelling. Radiographic findings of the right stifle comprised periarticular osteophyte formation consistent with mild degenerative joint disease and joint effusion. Surgical correction involving right trochlear wedge recession sulcoplasty and lateral imbrication was carried out to stabilise the patella in the trochlear groove. The right hind limb lameness resolved, and the patella was stable at a 6-month postoperative examination. One year postoperatively, the right patella was luxating again concurrent with bilateral stifle effusions. Euthanasia was performed twenty months after surgery due to recurrent lameness in the right hind limb.

  13. [The principal mechanisms of age-related involution of wrist bones].

    Science.gov (United States)

    Pigolkin, Iu I; Fedulova, M V; Iurchenko, M A

    2012-01-01

    The objective of the present study was to elucidate the general mechanisms underlying age-specific changes in the bone tissue of the wrists by the assessment of the signs of their ageing on X-ray images. Roentgenograms of the left wrist of 261 men and 333 women at the age varying from 18 to 90 years were analysed by the planigraphic technique with the use of a scoring system for the estimation of the severity of the signs of ageing (osteoporosis, osteophytes). The study has shown that the signs of ageing in wrist bones become apparent approximately 4-6 years after the completion of ossification. The age-specific changes in the bones are characterized by a strong sexual dimorphism while both the rate of appearance and the intensity of expression of the markers of bone ageing depend on their localization on the radius and phalanges.

  14. PROGRESSIVE SYRINGOHYDROMYELIA AND DEGENERATIVE AXONOPATHY IN A BOBCAT (LYNX RUFUS) FOLLOWING SURGICAL CORRECTION OF A CHIARI-LIKE MALFORMATION.

    Science.gov (United States)

    Sadler, Ryan; Schumacher, Juergen; Ramsay, Edward; McCleery, Brynn; Baine, Katherine; Thomas, William; Nobrega-Lee, Michelle; Henry, George A; Newman, Shelley J

    2016-03-01

    A 3-yr-old male captive bobcat (Lynx rufus) presented with chronic ataxia and right-sided head tilt. Magnetic resonance imaging (MRI) revealed cerebellar crowding and compression consistent with Chiari-like malformation. The clinical signs did not improve after surgical occipital craniectomy, and 2 mo postoperatively a second MRI showed hydromyelia and continued cerebellar compression. The bobcat was euthanized, and necropsy showed chronic focal cerebellar herniation and chronic multifocal atlanto-occipital joint osteophyte proliferation. Histology confirmed the presence of a thick fibrous membrane along the caudal aspect of the cerebellar vermis, suggestive of postoperative adhesions, and axonal degeneration of the cervical spinal cord, even in sections without a central canal lesion. These lesions appear to have been complications associated with surgical correction of the Chiari-like malformation.

  15. Pterygoid hamulus bursitis as a cause of craniofacial pain: a case report.

    Science.gov (United States)

    Cho, Jin-Yong; Cheon, Kang-Yong; Shin, Dong-Whan; Chun, Won-Bae; Lee, Ho

    2013-06-01

    Pain on the soft palate and pharynx can originate in several associated structures. Therefore, diagnosis of patients who complain of discomfort in these areas may be difficult and complicated. Pterygoid hamulus bursitis is a rare disease showing various symptoms in the palatal and pharyngeal regions. As such, it can be one of the reported causes of pain in these areas. Treatment of hamular bursitis is either conservative or surgical. If the etiologic factor of bursitis is osteophytic formation on the hamulus or hypertrophy of the bursa, resection of the hamulus is usually the preferred surgical treatment. We report on a case of bursitis that was managed successfully by surgical treatment and a review of the literature.

  16. [Leptin: a link between obesity and osteoarthritis?].

    Science.gov (United States)

    Terlain, Bernard; Presle, Nathalie; Pottie, Pascale; Mainard, Didier; Netter, Patrick

    2006-10-01

    In addition to aging, obesity is one of the most common underlying causes of osteoarthritis (OA). Mechanical loading, together with biochemical and systemic factors linked to altered lipid metabolism, are thought to contribute to the onset of OA. It has been suggested that OA is a systemic metabolic disease associated with lipid disorders affecting joint homeostasis. These gradual changes may be due to the local effect of adipokines, and especially leptin. Indeed, their relative levels in joints differ from that found in plasma. In particular, leptin levels are increased and adiponectin and resistin levels are reduced This hypothesis is supported by--leptin overexpression in OA cartilage and its correlation with the degree of cartilage destruction,--abundant leptin synthesis by osteophytes, and--the high leptin levels found in OA joints from female patients. This link between OA and adipokines provides new leads regarding the prevention of OA and the identification of new drug targets.

  17. Veias do sistema porta-hepático em gansos domésticos Veins from hepatic portal vein system in domestic geese

    Directory of Open Access Journals (Sweden)

    Tatiana C. Santos

    2009-04-01

    Full Text Available A distribuição intraparenquimal das veias porta-hepáticas foi estudada em 30 gansos domésticos. Latex Neoprene corado foi injetado pela veia isquiática e os animais forma fixados por imersão e injeção intramuscular com formol a 10% e dissecados. O fígado esteve composto por um grande lobo hepático direito e por um lobo hepático esquerdo menor, os quais estiveram conectados por uma ponte de parênquima. O lobo direito do fígado teve exclusivamente vasos do sistema porta-hepático formados pela distribuição intraparenquimal da veia porta-hepática direita, enquanto que no lobo esquerdo estes originaram-se da veia porta-hepática direita e de pequenas veias porta-hepáticas esquerdas. A veia porta-hepática direita emitiu o ramo caudal direito, que emitiu um pequeno ramo caudolateral direito e um grande ramo caudomedial direito. Cranialmente esta veia emitiu os ramos craniais direito e ramos lateral direito. A porção transversa da veia porta-hepática direita cruzou para o lobo hepático esquerdo, emitindo de 1 a 6 pequenos ramos craniais e caudais para a região média do fígado. No lobo esquerdo, o ramo esquerdo da veia porta-hepática direita emitiu o ramo cranial esquerdo, o ramo lateral esquerdo e o ramo medial. De 1 a 6 veias porta-hepáticas esquerdas foram identificadas desembocando ou no ramo esquerdo da veia porta-hepática direita ou em sua porção transversa, oriundos do ventrículo gástrico e do pró-ventrículo. Em 40% dos gansos uma veia porta-hepática própria oriunda da confluência de vasos venosos da face esquerda do ventrículo distribuiu-se na extremidade caudal do lobo esquerdo isoladamente.The intraparenchymal distribution of the hepatic portal veins in 30 domestic geese were studied. Stained Neoprene latex was injected into the isquiatic vessels, and the animals were fixed in 10% formaldehyde by immersion and intramuscular injection. The liver of geese was composed of a large right and a smaller left

  18. Influence of friction on buckling of a drill string in the circular channel of a bore hole

    Directory of Open Access Journals (Sweden)

    Valery Gulyayev

    2016-10-01

    Full Text Available Abstract Enhancement of technology and techniques for drilling deep directed oil and gas bore hole is one of the most important problems of the current petroleum industry. Not infrequently, the drilling of these bore holes is attended by occurrence of extraordinary situations associated with technical accidents. Among these is the Eulerian loss of stability of a drill string in the channel of a curvilinear bore hole. Methods of computer simulation should play a dominant role in prediction of these states. In this paper, a new statement of the problem of critical buckling of the drill strings in 3D curvilinear bore holes is proposed. It is based on combined use of the theory of curvilinear elastic rods, Eulerian theory of stability, theory of channel surfaces, and methods of classical mechanics of systems with nonlinear constraints. It is noted that the stated problem is singularly perturbed and its solutions have the shapes of localized harmonic wavelets. The calculation results showed that the friction effects lead to essential redistribution of internal axial forces, as well as changing the eigenmode shapes and sites of their localization. These features make the buckling phenomena less predictable and raise the role of computer simulation of these effects.

  19. Biased self-perceptions of social competence and engagement in physical and relational aggression: the moderating role of peer status and sex.

    Science.gov (United States)

    McQuade, Julia D; Achufusi, Adaora K; Shoulberg, Erin K; Murray-Close, Dianna

    2014-01-01

    This study sought to expand on prior research suggesting that children low in peer status who either over- or underestimate their social competence relative to others' reports are more likely to be aggressive (White and Kistner [2011]. Journal of Abnormal Child Psychology, 39, 645-656). The curvilinear associations between social competence bias and two forms of aggression (physical and relational) were examined in a sample of 4th through 6th graders (n = 183); moderation by both sex and peer status (peer preference and popularity) also were tested. Social competence bias was operationally defined as the residual difference between child and teacher ratings of the child's social competence. Aggression and peer status were measured using peer nomination procedures. There was a significant curvilinear association between social competence bias and physical aggression moderated by both types of peer status. For low peer status children greater underestimation and overestimation of social competence was associated with higher physical aggression. The curvilinear association between social competence bias and relational aggression was moderated by both peer status and sex. Popular boys had higher rates of relational aggression when they had accurate, rather than biased, self-perceptions of social competence. However, for very highly preferred girls, a more extreme positive bias was associated with an exponential increase in relational aggression. Results are discussed in terms of implications for aggression theory and intervention.

  20. Determination of the modular elliptic function in problems of free-flow filtration

    Science.gov (United States)

    Anakhaev, K. N.

    2016-09-01

    The calculated dependences in elementary functions for determining the modular elliptic function λ(τ) =λ1 + iλ2 obtained on the basis of consecutive (six) conformal mappings of a curvilinear triangle to a complex half-plane are presented. Comparison of the values of λ(τ) from the proposed dependences with the results of the Hamel-Gunter exact analytical solution for the boundary contour of the curvilinear triangle, i.e., the real axis of the complex half-plane, gives a very close coincidence (with the largest error of ≤1%). The use of the complex values of the function λ(τ) for the entire internal region of the curvilinear triangle makes it possible to solve one of the most difficult problems of the theory of filtration (filtration through a rectangular dam) in the direct formulation and, for the first time, to construct the pattern of an equal filtration-rate field (the family of isotaches) over the entire internal region of the dam. In this case, the boundary values of filtration rates for special cases (along the sides and along the base of the dam) completely coincide with the results of the Masket exact analytical calculations.

  1. Multiphasic interactions between nucleotides and target proteins

    CERN Document Server

    Nissen, Per

    2016-01-01

    The nucleotides guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp) bind to target proteins to promote bacterial survival (Corrigan et al. 2016). Thus, the binding of the nucleotides to RsgA, a GTPase, inhibits the hydrolysis of GTP. The dose response, taken to be curvilinear with respect to the logarithm of the inhibitor concentration, is instead much better (P<0.001 when the 6 experiments are combined) represented as multiphasic, with high to exceedingly high absolute r values for the straight lines, and with transitions in the form of non-contiguities (jumps). Profiles for the binding of radiolabeled nucleotides to HprT and Gmk, GTP synthesis enzymes, were, similarly, taken to be curvilinear with respect to the logarithm of the protein concentration. However, the profiles are again much better represented as multiphasic than as curvilinear (the P values range from 0.047 to <0.001 for each of the 8 experiments for binding of ppGpp and pppGpp to HprT). The binding of GTP to HprT and ...

  2. An efficient and numerically stable procedure for generating sextic force fields in normal mode coordinates.

    Science.gov (United States)

    Sibaev, M; Crittenden, D L

    2016-06-01

    In this paper, we outline a general, scalable, and black-box approach for calculating high-order strongly coupled force fields in rectilinear normal mode coordinates, based upon constructing low order expansions in curvilinear coordinates with naturally limited mode-mode coupling, and then transforming between coordinate sets analytically. The optimal balance between accuracy and efficiency is achieved by transforming from 3 mode representation quartic force fields in curvilinear normal mode coordinates to 4 mode representation sextic force fields in rectilinear normal modes. Using this reduced mode-representation strategy introduces an error of only 1 cm(-1) in fundamental frequencies, on average, across a sizable test set of molecules. We demonstrate that if it is feasible to generate an initial semi-quartic force field in curvilinear normal mode coordinates from ab initio data, then the subsequent coordinate transformation procedure will be relatively fast with modest memory demands. This procedure facilitates solving the nuclear vibrational problem, as all required integrals can be evaluated analytically. Our coordinate transformation code is implemented within the extensible PyPES library program package, at http://sourceforge.net/projects/pypes-lib-ext/.

  3. An effective meshfree reproducing kernel method for buckling analysis of cylindrical shells with and without cutouts

    Science.gov (United States)

    Sadamoto, S.; Ozdemir, M.; Tanaka, S.; Taniguchi, K.; Yu, T. T.; Bui, T. Q.

    2017-02-01

    The paper is concerned with eigen buckling analysis of curvilinear shells with and without cutouts by an effective meshfree method. In particular, shallow shell, cylinder and perforated cylinder buckling problems are considered. A Galerkin meshfree reproducing kernel (RK) approach is then developed. The present meshfree curvilinear shell model is based on Reissner-Mindlin plate formulation, which allows the transverse shear deformation of the curved shells. There are five degrees of freedom per node (i.e., three displacements and two rotations). In this setting, the meshfree interpolation functions are derived from the RK. A singular kernel is introduced to impose the essential boundary conditions because of the RK shape functions, which do not automatically possess the Kronecker delta property. The stiffness matrix is derived using the stabilized conforming nodal integration technique. A convected coordinate system is introduced into the formulation to deal with the curvilinear surface. More importantly, the RKs taken here are used not only for the interpolation of the curved geometry, but also for the approximation of field variables. Several numerical examples with shallow shells and full cylinder models are considered, and the critical buckling loads and their buckling mode shapes are calculated by the meshfree eigenvalue analysis and examined. To show the accuracy and performance of the developed meshfree method, the computed critical buckling loads and mode shapes are compared with reference solutions based on boundary domain element, finite element and analytical methods.

  4. Choice of velocity variables for complex flow computation

    Science.gov (United States)

    Shyy, W.; Chang, G. C.

    1991-01-01

    The issue of adopting the velocity components as dependent velocity variables for the Navier-Stokes flow computations is investigated. The viewpoint advocated is that a numerical algorithm should preferably honor both the physical conservation law in differential form and the geometric conservation law in discrete form. With the use of Cartesian velocity vector, the momentum equations in curvilinear coordinates can retain the full conservation-law form and satisfy the physical conservation laws. With the curvilinear velocity components, source terms appear in differential equations and hence the full conservation law form can not be retained. In discrete expressions, algorithms based on the Cartesian components can satisfy the geometric conservation-law form for convection terms but not for viscous terms; those based on the curvilinear components, on the other hand, cannot satisfy the geometric conservation-law form for either convection or viscous terms. Several flow solutions for domain with 90 and 360 degree turnings are presented to illustrate the issues of using the Cartesian velocity components and the staggered grid arrangement.

  5. Scalable shape-controlled fabrication of curved microstructures using a femtosecond laser wet-etching process

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Hao; Yang, Qing; Chen, Feng, E-mail: chenfeng@mail.xjtu.edu.cn; Liu, Hewei; Du, Guangqing; Deng, Zefang; Si, Jinhai; Yun, Feng; Hou, Xun

    2013-07-01

    Materials with curvilinear surface microstructures are highly desirable for micro-optical and biomedical devices. However, realization of such devices efficiently remains technically challenging. This paper demonstrates a facile and flexible method to fabricate curvilinear microstructures with controllable shapes and dimensions. The method composes of femtosecond laser exposures and chemical etching process with the hydrofluoric acid solutions. By fixed-point and step-in laser irradiations followed by the chemical treatments, concave microstructures with different profiles such as spherical, conical, bell-like and parabola were fabricated on silica glasses. The convex structures were replicated on polymers by the casting replication process. In this work, we used this technique to fabricate high-quality microlens arrays and high-aspect-ratio microwells which can be used in 3D cell culture. This approach offers several advantages such as high-efficient, scalable shape-controllable and easy manipulations. - Highlights: • We demonstrate a flexible method to fabricate curvilinear microstructures. • This method composes of femtosecond laser exposures and chemical etching process. • Concave microstructures with different profiles were fabricated on silica glasses. • High-quality microlens arrays and high-aspect-ratio microwells were fabricated.

  6. Nonlinear effects of team tenure on team psychological safety climate and climate strength: Implications for average team member performance.

    Science.gov (United States)

    Koopmann, Jaclyn; Lanaj, Klodiana; Wang, Mo; Zhou, Le; Shi, Junqi

    2016-07-01

    The teams literature suggests that team tenure improves team psychological safety climate and climate strength in a linear fashion, but the empirical findings to date have been mixed. Alternatively, theories of group formation suggest that new and longer tenured teams experience greater team psychological safety climate than moderately tenured teams. Adopting this second perspective, we used a sample of 115 research and development teams and found that team tenure had a curvilinear relationship with team psychological safety climate and climate strength. Supporting group formation theories, team psychological safety climate and climate strength were higher in new and longer tenured teams compared with moderately tenured teams. Moreover, we found a curvilinear relationship between team tenure and average team member creative performance as partially mediated by team psychological safety climate. Team psychological safety climate improved average team member task performance only when team psychological safety climate was strong. Likewise, team tenure influenced average team member task performance in a curvilinear manner via team psychological safety climate only when team psychological safety climate was strong. We discuss theoretical and practical implications and offer several directions for future research. (PsycINFO Database Record

  7. Rashba Torque Driven Domain Wall Motion in Magnetic Helices.

    Science.gov (United States)

    Pylypovskyi, Oleksandr V; Sheka, Denis D; Kravchuk, Volodymyr P; Yershov, Kostiantyn V; Makarov, Denys; Gaididei, Yuri

    2016-01-01

    Manipulation of the domain wall propagation in magnetic wires is a key practical task for a number of devices including racetrack memory and magnetic logic. Recently, curvilinear effects emerged as an efficient mean to impact substantially the statics and dynamics of magnetic textures. Here, we demonstrate that the curvilinear form of the exchange interaction of a magnetic helix results in an effective anisotropy term and Dzyaloshinskii-Moriya interaction with a complete set of Lifshitz invariants for a one-dimensional system. In contrast to their planar counterparts, the geometrically induced modifications of the static magnetic texture of the domain walls in magnetic helices offer unconventional means to control the wall dynamics relying on spin-orbit Rashba torque. The chiral symmetry breaking due to the Dzyaloshinskii-Moriya interaction leads to the opposite directions of the domain wall motion in left- or right-handed helices. Furthermore, for the magnetic helices, the emergent effective anisotropy term and Dzyaloshinskii-Moriya interaction can be attributed to the clear geometrical parameters like curvature and torsion offering intuitive understanding of the complex curvilinear effects in magnetism.

  8. Radiographic assessment of the femorotibial joint of the CCLT rabbit experimental model of osteoarthritis

    Directory of Open Access Journals (Sweden)

    Collard Fabien

    2010-01-01

    Full Text Available Abstract Background The purposes of the study were to determine the relevance and validity of in vivo non-invasive radiographic assessment of the CCLT (Cranial Cruciate Ligament Transection rabbit model of osteoarthritis (OA and to estimate the pertinence, reliability and reproducibility of a radiographic OA (ROA grading scale and associated radiographic atlas. Methods In vivo non-invasive extended non weight-bearing radiography of the rabbit femorotibial joint was standardized. Two hundred and fifty radiographs from control and CCLT rabbits up to five months after surgery were reviewed by three readers. They subsequently constructed an original semi-quantitative grading scale as well as an illustrative atlas of individual ROA feature for the medial compartment. To measure agreements, five readers independently scored the same radiographic sample using this atlas and three of them performed a second reading. To evaluate the pertinence of the ROA grading scale, ROA results were compared with gross examination in forty operated and ten control rabbits. Results Radiographic osteophytes of medial femoral condyles and medial tibial condyles were scored on a four point scale and dichotomously for osteophytes of medial fabella. Medial joint space width was scored as normal, reduced or absent. Each ROA features was well correlated with gross examination (p s = 0.68 and rs = 0.58, p s = 0.64, p Conclusion Non-invasive in vivo radiography of the rabbit femorotibial joint is feasible, relevant and allows a reproducible grading of experimentally induced OA lesion. The radiographic grading scale and atlas presented could be used as a template for in vivo non invasive grading of ROA in preclinical studies and could allow future comparisons between studies.

  9. Is physical activity, practiced as recommended for health benefit, a risk factor for osteoarthritis?

    Science.gov (United States)

    Lefèvre-Colau, Marie-Martine; Nguyen, Christelle; Haddad, Rebecca; Delamarche, Paul; Paris, Guillaume; Palazzo, Clémence; Poiraudeau, Serge; Rannou, François; Roren, Alexandra

    2016-06-01

    In this critical narrative review, we examine the role of physical activity (PA), recreational and elite sports in the development of knee/hip osteoarthritis (OA), taking into account the role of injury in this relationship. The process of article selection was unsystematic. Articles were selected on the basis of the authors' expertise, self-knowledge, and reflective practice. In the general adult population, self-reported diagnosis of knee/hip OA was not associated with low, moderate or high levels of PA. For studies using radiographic knee/hip OA as a primary outcome, the incidence of asymptomatic radiographic OA was higher for subjects with the highest quartile of usual PA than the least active subjects. The risk of incident radiographic knee/hip OA features was increased for subjects with a history of regular sports participation (for osteophyte formation but not joint space narrowing). This risk depended on the type of sport (team and power sports but not endurance and running), and certain conditions (high level of practice) were closely related to the risk of injury. The prevalence of radiographic OA was significantly higher, especially the presence of osteophytes, in former elite athletes than controls. The risk of OA was higher with participation in mixed sports, especially soccer or power sports, than endurance sport. However, the prevalence of clinical OA between former elite athletes and controls was similar, with less hip/knee disability in former athletes. Moderate daily recreational or sport activities, whatever the type of sport, are not a consistent risk factor for clinical or radiographic knee/hip OA. Risk of injury in different sports may be the key factor to understanding the risk of OA related to sport.

  10. Nontraumatic bifid mandibular condyles in asymptomatic and symptomatic temporomandibular joint subjects

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Bong Hae; Jung, Yun Hoa [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

    2013-03-15

    This study was performed to determine the prevalence of bifid mandibular condyles (BMCs) in asymptomatic and symptomatic temporomandibular joint (TMJ) subjects with no traumatic history, and to assess their impact on clinical and radiographic manifestations of TMJ. A total of 3,046 asymptomatic and 4,378 symptomatic patients were included in the study. Cone-beam computed tomography (CBCT) images were reviewed for bifid condyles. T-tests were used to compare the frequency of BMCs when stratified by symptom, gender, and side. In BMC patients, the clinical features of pain and noise, osseous changes, and parasagittal positioning of the condyles were compared between the normally shaped condyle side and the BMC side using chi-squared tests. Fifteen (0.49%) asymptomatic and 22 (0.50%) symptomatic patients were found to have BMCs. Among the bilateral cases, the number of condyles were 19 (0.31%) and 25 (0.29%), respectively. No statistically significant differences were found between asymptomatic and symptomatic patients, between female and male patients, or between the right and left sides (p>0.05). Compared with the normally shaped condyle side, the BMC side showed no statistically significant differences in the distribution of pain and noise, parasagittal condylar position, or condylar osseous changes, with the exception of osteophytes. In the symptomatic group, osteophytes were found more frequently on the normally shaped condyle side than the BMC side (p<0.05). BMCs tended to be identified as an incidental finding. The presence of BMC would not lead to any TMJ symptoms or cause osseous changes.

  11. LECTURE ON ACUPUNCTURE PartⅠ Clinical Acupuncture Lecture Thirty-fiveCervical Spondylopathy

    Institute of Scientific and Technical Information of China (English)

    罗汀; 王卫; 徐力

    2004-01-01

    @@ Cervical spondylopathy, also known as cervical syndrome, is a commonly encountered disease in the middle-aged and elderly people. This disease mostly results from the retrograde affection of the cervical intervertebral disc and hyperosteogeny of the cervical vertebrae. This hyperplastic substance may stimulate and give rise to oppression to the surrounding spinal cord, nerve roots, blood vessels and sympathetic nerves, resulting in a series of symptoms as numbness, pain, etc. in the neck, shoulder and the upper limbs. The cervical vertebra of the human spine is smallest in the size, weakest in the strength, higher in the motor range and frequency, and bigger in the bearing of per unit area. Along with the increasing of people's age and the accumulated aftereffect of chronic and acute injury, the pulpiform nucleus of the cervical intervertebral disc presents retrograde affection, dehydration, bulge and rupture of the fibrous ring, narrowing of the intervertebral space, and reduction in the stability of cervical vertebrae due to injury and slackening of intervertebral ligaments to stretch and to induce compression upon periosteum. All these changes may lead to break of blood vessels to cause bleeding and hematoma. With the organization of hematoma and calcium salt deposit, osteophyte is formed at last. When the protruded intervertebral disc and hyperplastic osteophyte stimulate and oppress the surrounding spinal nerve root, vertebral artery or spinal cord, the resultant injury, aseptic inflammation, reactions after renovation, etc. will generate a series of clinical symptoms of cervical spondylopathy. In Western medicine, there are five types of cervical spondylopathy including stiff-neck type, nerve root type, spinal cord type, vertebral artery type and sympathetic nerve type. The stiff-neck type, nerve root type and vertebral artery type will be introduced in this article.

  12. [Bilateral SLAC (scapholunate advanced collapse) wrist: an unusual entity. Apropos of a 7000-year-old prehistoric case].

    Science.gov (United States)

    Masmejean, E; Dutour, O; Touam, C; Oberlin, C

    1997-01-01

    SLAC (Scapho-Lunate Advanced Collapse) wrist is the most common form of osteoarthritis of the wrist. The main aetiology is ligamentous rotary subluxation of the scaphoid. The authors report on a case of bilateral SLAC wrist, identified on a prehistoric skeleton derived from the Hassi-el-Abiod site in the malian Sahara (Dutour, 1989). The paleopathological study consisted of macroscopic examination and radiological examination. Radiocarbon dating situated this human occupation to 7 thousand years ago. The diseases observed included bilateral radiocarpal lesions in an adult male individual. The degree of preservation of the carpal skeleton was 90%. Lesions were bilateral, but predominantly affected the right side. The radial styloid processes presented a lateral osteophytic cuff, giving a tapered "pen-nib" appearance. The scaphoid has a normal shape, but presented posterior and lateral osteophytes. The scaphoid surfaces of the two distal extremities of the radius and the corresponding parts of the scaphoid showed characteristic polishing. X-rays showed a band of condensation corresponding to the ivory region on the articular surfaces. In this case, the bilateral nature and the absence of any obvious macrotraumatic aetiology suggest that the only aetiology was progressive and bilateral ligamentous distension, due to repeated microtrauma analogous to that observed in sports disease (volley-ball) or in occupational diseases (jackhammer). The manufacture of stone tools (carved or polished) can be incriminated in the pathogenesis of these lesions. These lesions are therefore useful markers of repeated microtraumatic activities or "activity markers". The is the first paleopathological description and the oldest known case of bilateral SLAC wrist.

  13. Influencing factors analysis of spontaneous knee joint osteoarthritis among middle aged and old aged pople in Xi'an

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WANG Kun-zheng; DANG Xiao-qian; BAI Chuan-yi; WANG Chun-sheng; SHI ZHi-bin; MA Shu-qiang

    2007-01-01

    Objective:To explore the prevalence rate of knee joint osteoarthritis and its pathogenetic features among the middle-aged and old aged people in the urban and rural area of Xi'an. Methods: From May to October 2005, 1 538 Han nationality above 40 years in Xi'an were investigated according to stratified and cluster random sampling. The same questionnaire was delivered to subjects who had been given normotopia and lateral position radiographic examination in both knees. Excluded from etiological arthritis, some subjects with clinical symptoms and a radiographic grade (beyond Kellgren & Lawrence grade Ⅱ ) were finally diagnosed as spontaneous knee joint osteoarthritis. All analyses were performed with SPSS 13.0 and t test, U test. Single factor analysis and multiple logistic regression analysis were used to analyze dates. Results: The total prevalence of spontaneous knee joint osteoarthritis was 12. 1% with 2.5% and 2.1% for right and left knees, respectively. The prevalence of knee joint osteoarthritis in women was 2.5 times of that in men (17.2% vs 6.8%, P=0.000). the osteophyte prevalence in women was 2.3 times of that in men (26.5% vs 11.4%, P=0.000). The prevalence of knee joint osteoarthritis and osteophyte increased with the growth of age. So did the symptomatic knee, except for the age group of 56-60 years and 66-70 years. The prevalence of symptomatic knee joint for urban area was significantly higher than that for rural area (56. 3% vs 45.3%, P=0.003). In women, the prevalence of knee joint osteoarthritis increased significantly with the increasing of body mass index, which had not been observed in men. Female and obesity are the risk factors for osteoarthritis, but bean and its products and meat could prevent the osteoarthritis. Conclusion: Old age, female and obesity serve as risk factors for knee joint osteoarthritis.

  14. Relationship of specific MRI findings to treatment outcomes in patients receiving transforaminal epidural steroid injections

    Energy Technology Data Exchange (ETDEWEB)

    Lechmann, Marco; Rosskopf, Andrea; Ehrmann, Christine; Sutter, Reto; Pfirrmann, Christian W.A.; Peterson, Cynthia K. [University of Zuerich, Department of Radiology, Orthopaedic University Hospital Balgrist, Zuerich (Switzerland)

    2016-12-15

    To determine whether specific MRI findings are related to outcomes after lumbar transforaminal epidural steroid injections (TFESI) and to assess the inter-rater reliability of imaging diagnosis. A prospective outcomes study on 156 consecutive patients with 1-month follow-up outcomes data and MRI within 3 months of TFESI was conducted. Pain levels (numerical rating scale) (NRS) were recorded prior to injection. Overall 'improvement' was determined using the Patients Global Impression of Change (PGIC) scale and NRS data were collected at three time points post injection. Two radiologists independently evaluated all images blinded to treatment outcome for reliability of diagnosis. The Chi-square test compared MRI findings for the senior radiologist to 'improvement'. NRS change scores were compared to MRI findings with the unpaired t-test or ANOVA. Kappa and percent agreement assessed inter-rater agreement of diagnosis. The only abnormality linked to 'improvement' (p = 0.03) and higher NRS change scores (p = 0.0001) at 1 month was the disc herniation morphology 'protrusion + sequestration'. Patients with degeneration by osteophytes (p = 0.034), grade 3 foraminal nerve root compression (p = 0.01) and foraminal/extraforaminal location of herniation (p = 0.014) also had higher 1 month NRS change scores. Reliability of diagnosis was 'fair' to 'substantial' depending on MRI findings. Patients with disc protrusion plus sequestration were significantly more likely to report overall improvement and more pain reduction at 1 month. Higher pain reduction was noted in patients with degeneration by osteophytes, grade 3 foraminal nerve root compression, or foraminal/extraforaminal disc herniation location. (orig.)

  15. Comparison of conventional panoramic radiography and panoramic digital subtraction radiography in detection of simulated lesions of mandibular condyle

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2008-12-01

    Full Text Available "n  "nBackground and Aim: Digital subtraction Radiography (DSR is a method of accurate assessing condylar head changes. several studies have been carried out in applying DSR in dentistry, however there is a few number of studies in efficacy of DSR method in assesment of condylar head changes, The aim of this study was to compare panoramic radiography and DSR detecting simulated lesions of the mandibular condyl. "nMaterials and Methods: this was a process reaserch study, in which two dry human skulls with no obvious temporomandibular joint pathology were used. Osteophytic lesions were simulated using three sizes of bone chips that were placed on the medial portion of anterior and superolateral aspects of the condyle. Osteolytic lesions were simulated making 1 and 2 mm holes using round burr in the central portion of anterior aspect and Lateral pole of the condyle. Panoramic radiographs were prepared with and without the lesions in place. These paired radiographs were digitized and digital- subtraction images of the original panoramic images were obtained. Eight observers evaluated 155 images of each modality for the presence or absence and the type of simulated lesions of the mandibular condyle. Sensitivity, specificity, reliability and measure of agreement were analyzed using kappa test and crossed tables and qualitative variables were assess by chi-square and fisher's Exact test. "nResults: Specificity of panoramic and DSR methods were 15.4% and 66.7% respectively. Sensitivity of panoramic and DSR methods were 61.1% and 80.6% for osteophytic lesions and 37.5% and 83.3% for Osteolytic lesions. The percentage of correct decisions made in DSR method was significantly more than conventional panoramic method (82.6% vs 41.9% (p<0.0001. "nConclusion: Based on the results of this study digital subtraction technique was significantly more accurate than the panoramic radiographs in detection of simulated lesions of the mandibular condyle.

  16. Affective and cognitive prefrontal cortex projections to the lateral habenula in humans.

    Directory of Open Access Journals (Sweden)

    Karin eVadovičová

    2014-10-01

    Full Text Available Anterior insula (AI and dorsal ACC (dACC are known to process information about pain, loss, adversities, bad, harmful or suboptimal choices and consequences that threaten survival or well-being. Also pregenual ACC (pgACC is linked to loss and pain, being activated by sad thoughts and regrets. Lateral habenula (LHb is stimulated by predicted and received pain, discomfort, aversive outcome, loss. Its chronic stimulation makes us feel worse/low and gradually stops us choosing and moving for the suboptimal or punished choices, by direct and indirect (via rostromedial tegmental nucleus RMTg inhibition of DRN and VTA/SNc. The response selectivity of LHb neurons suggests their cortical input from affective and cognitive evaluative regions that make expectations about bad, unpleasant or suboptimal outcomes. Based on these facts we predicted direct dACC, pgACC and AI projections to LHb, which form part of an adversity processing circuit that learns to avoid bad outcomes by suppressing dopamine and serotonin signal. To test this connectivity we used Diffusion Tensor Imaging (DTI. We found dACC, pgACC, AI and caudolateral OFC projections to LHb. We predicted no corticohabenular projections from the reward processing regions: medial OFC (mOFC and ventral ACC (vACC because both respond most strongly to good, high valued stimuli and outcomes, inducing dopamine and serotonin release. This lack of LHb projections was confirmed for vACC and likely for mOFC. The surprising findings were the corticohabenular projections from the cognitive prefrontal cortex regions, known for flexible reasoning, planning and combining whatever information are relevant for reaching current goals. We propose that the prefrontohabenular projections provide a teaching signal for value-based choice behaviour, to learn to deselect, avoid or inhibit the potentially harmful, low valued or wrong choices, goals, strategies, predictions and ways of doing things, to prevent bad or suboptimal

  17. Sex differences in the representation of call stimuli in a songbird secondary auditory area

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    Nicolas eGiret

    2015-10-01

    Full Text Available Understanding how communication sounds are encoded in the central auditory system is critical to deciphering the neural bases of acoustic communication. Songbirds use learned or unlearned vocalizations in a variety of social interactions. They have telencephalic auditory areas specialized for processing natural sounds and considered as playing a critical role in the discrimination of behaviorally relevant vocal sounds. The zebra finch, a highly social songbird species, forms lifelong pair bonds. Only male zebra finches sing. However, both sexes produce the distance call when placed in visual isolation. This call is sexually dimorphic, is learned only in males and provides support for individual recognition in both sexes. Here, we assessed whether auditory processing of distance calls differs between paired males and females by recording spiking activity in a secondary auditory area, the caudolateral mesopallium (CLM, while presenting the distance calls of a variety of individuals, including the bird itself, the mate, familiar and unfamiliar males and females. In males, the CLM is potentially involved in auditory feedback processing important for vocal learning. Based on both the analyses of spike rates and temporal aspects of discharges, our results clearly indicate that call-evoked responses of CLM neurons are sexually dimorphic, being stronger, lasting longer and conveying more information about calls in males than in females. In addition, how auditory responses vary among call types differ between sexes. In females, response strength differs between familiar male and female calls. In males, temporal features of responses reveal a sensitivity to the bird’s own call. These findings provide evidence that sexual dimorphism occurs in higher-order processing areas within the auditory system. They suggest a sexual dimorphism in the function of the CLM, contributing to transmit information about the self-generated calls in males and to storage of

  18. Distinct expression of Cbln family mRNAs in developing and adult mouse brains.

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    Miura, Eriko; Iijima, Takatoshi; Yuzaki, Michisuke; Watanabe, Masahiko

    2006-08-01

    Cbln1 belongs to the C1q and tumour necrosis factor superfamily, and plays crucial roles as a cerebellar granule cell-derived transneuronal regulator for synapse integrity and plasticity in Purkinje cells. Although Cbln2-Cbln4 are also expressed in the brain and could form heteromeric complexes with Cbln1, their precise expressions remain unclear. Here, we investigated gene expression of the Cbln family in developing and adult C57BL mouse brains by reverse transcriptase-polymerase chain reaction (RT-PCR), Northern blot, and high-resolution in situ hybridization (ISH) analyses. In the adult brain, spatial patterns of mRNA expression were highly differential depending on Cbln subtypes. Notably, particularly high levels of Cbln mRNAs were expressed in some nuclei and neurons, whereas their postsynaptic targets often lacked or were low for any Cbln mRNAs, as seen for cerebellar granule cells/Purkinje cells, entorhinal cortex/hippocampus, intralaminar group of thalamic nuclei/caudate-putamen, and dorsal nucleus of the lateral lemniscus/central nucleus of the inferior colliculus. In the developing brain, Cbln1, 2, and 4 mRNAs appeared as early as embryonic day 10-13, and exhibited transient up-regulation during the late embryonic and neonatal periods. For example, Cbln2 mRNA was expressed in the cortical plate of the developing neocortex, displaying a high rostromedial to low caudolateral gradient. In contrast, Cbln3 mRNA was selective to cerebellar granule cells throughout development, and its onset was as late as postnatal day 7-10. These results will provide a molecular-anatomical basis for future studies that characterize roles played by the Cbln family.

  19. Development and distribution of PAG-immunoreactive neurons in the central pathway of trigeminal proprioception of the rat brainstem

    Institute of Scientific and Technical Information of China (English)

    PANG You-wang; LI Jin-lian

    2002-01-01

    Objective:To investigate the development and distribution of phosphate-activated glutaminase like immunoreactive (PAG-LI) neurons in the central pathway of trigeminal proprioception of the rat brainstem.Methods: The immunohistochemitry techniques were used. Results: (1) At embryonic day 17 (E17), PAGLI neurons were initially observed in the mesencephalic trigeminal nucleus (Vme). All PAG-LI neurons were large round neurons with moderate immunostaining. The immunoreactivity grew intense and attained adultlike pattern at P10. (2) Not until postnatal day 10 (P10) did a few PAG-LI neurons appear in the area ventral to the motor trigeminal nucleus (AVM) and area dorsal to the superior olivery nucleus (ADO), and not until P12 in the dorsomedial part of the subnucleus oralis of the spinal trigeminal nucleus (Vodm) and dorsomedial part of the principal sensory trigeminal nucleus (Vpdm). As development proceeded, more and more neurons in them were immunostained, and some PAG-LI neurons were detected in the lateral reticular formation adjacent to the Vodm(LRF)and the caudolateral part of the supratrigeminal nucleus (Vsup-CL) at P21.Conclusion: In the central pathway of trigeminal proprioception of the rat brainstem, PAG-LI neurons appeared during two stages: The first stage from E17 to P10, PAG-LI neurons appeared in the Vme and reached adult-like pattern; the second stage from P10 to P21, PAG-LI neurons appeared in the Vodm, LRF,Vpdm, Vsup-CL, ADO, AVM and gradually reached adult-like pattern. This might be relative to the establishment of jaw movement patterns.

  20. High-resolution ultrasound biomicroscopy for monitoring ovarian structures in mice

    Directory of Open Access Journals (Sweden)

    Singh Jaswant

    2009-07-01

    Full Text Available Abstract Background Until recently, the limit of spatial resolution of ultrasound systems has prevented characterization of structures Methods Experiment 1 was a pilot study to develop methods of immobilization (physical restraint vs. general anesthesia and determine technical factors affecting ovarian images using ultrasound bio-microscopy in rats vs. mice. The hair coat was removed over the thoraco-lumber area using depilation cream, and a highly viscous acoustic gel was applied while the animals were maintained in sternal recumbency. In Experiment 2, changes in ovarian structures during the estrous cycle were monitored by twice daily ultrasonography in 10 mice for 2 estrous cycles. Results Ovarian images were not distinct in rats due to attenuation of ultrasound waves. Physical restraint, without general anesthesia, was insufficient for immobilization in mice. By placing the transducer face over the dorsal flank, the kidney was visualized initially as a point of reference. A routine of moving the transducer a few millimetres caudo-laterally from the kidney was established to quickly and consistently localize the ovaries; the total time to scan both ovaries in a mouse was about 10 minutes. By comparing vaginal cytology with non-anesthetized controls, repeated exposure to anesthesia did not affect the estrous cycle. Temporal changes in the number of follicles in 3 different size categories support the hypothesis that follicles ≥ 20 microns develop in a wave-like fashion. Conclusion The mouse is a suitable model for the study of ovarian dynamics using transcutaneous ultrasound bio-microscopy. Repeated general anesthesia for examination had no apparent effect on the estrous cycle, and preliminary results revealed a wave-like pattern of ovarian follicle development in mice.

  1. Spectral and spatial tuning of onset and offset response functions in auditory cortical fields A1 and CL of rhesus macaques.

    Science.gov (United States)

    Ramamurthy, Deepa L; Recanzone, Gregg H

    2016-12-07

    The mammalian auditory cortex is necessary for spectral and spatial processing of acoustic stimuli. Most physiological studies of single neurons in the auditory cortex have focused on the onset and sustained portions of evoked responses, but there have been far fewer studies on the relationship between onset and offset responses. In the current study, we compared spectral and spatial tuning of onset and offset responses of neurons in primary auditory cortex (A1) and the caudolateral (CL) belt area of awake macaque monkeys. Several different metrics were used to determine the relationship between onset and offset response profiles in both frequency and space domains. In the frequency domain, a substantial proportion of neurons in A1 and CL displayed highly dissimilar best stimuli for onset- and offset-evoked responses, though even for these neurons, there was usually a large overlap in the range of frequencies that elicited onset and offset responses and distributions of tuning overlap metrics were mostly unimodal. In the spatial domain, the vast majority of neurons displayed very similar best locations for onset- and offset-evoked responses, along with unimodal distributions of all tuning overlap metrics considered. Finally, for both spectral and spatial tuning, a slightly larger fraction of neurons in A1 displayed non-overlapping onset and offset response profiles, relative to CL, which supports hierarchical differences in the processing of sounds in the two areas. However, these differences are small compared to differences in proportions of simple cells (low overlap) and complex cells (high overlap) in primary and secondary visual areas.

  2. Combinatorial expression of Lef1, Lhx2, Lhx5, Lhx9, Lmo3, Lmo4, and Prox1 helps to identify comparable subdivisions in the developing hippocampal formation of mouse and chicken

    Directory of Open Access Journals (Sweden)

    Antonio eAbellán

    2014-07-01

    Full Text Available We carried out a study of the expression patterns of seven developmental regulatory genes (Lef1, Lhx2, Lhx9, Lhx5, Lmo3, Lmo4, and Prox1, in combination with topological position, to identify the medial pallial derivatives, define its major subdivisions, and compare them between mouse and chicken. In both species, the medial pallium is defined as a pallial sector adjacent to the cortical hem and roof plate/choroid tela, showing moderate to strong ventricular zone expression of Lef1, Lhx2 and Lhx9, but not Lhx5. Based on this, the hippocampal formation (indusium griseum, dentate gyrus, Ammon’s horn fields, and subiculum, the medial entorhinal cortex, and part of the amygdalo-hippocampal transition area of mouse appeared to derive from the medial pallium. In the chicken, based on the same position and gene expression profile, we propose that the hippocampus (including the V-shaped area, the parahippocampal area (including its caudolateral part, the entorhinal cortex, and the amygdalo-hippocampal transition area are medial pallial derivatives. Moreover, the combinatorial expression of Lef1, Prox1, Lmo4 and Lmo3 allowed the identification of dentate gyrus/CA3-like, CA1/subicular-like, and medial entorhinal-like comparable sectors in mouse and chicken, and point to the existence of mostly conserved molecular networks involved in hippocampal complex development. Notably, while the mouse medial entorhinal cortex derives from the medial pallium (similarly to the hippocampal formation, both being involved in spatial navigation and spatial memory, the lateral entorhinal cortex (involved in processing non-spatial, contextual information appears to derive from a distinct dorsolateral caudal pallial sector.

  3. A correlation analysis of the relationship between X-ray manifestation and knee pain degree in knee osteoarthritis%膝骨关节炎X线表现与膝关节疼痛程度的相关性分析

    Institute of Scientific and Technical Information of China (English)

    冯欢欢; 王培民; 范竞; 程建

    2013-01-01

    目的:分析膝骨关节炎X线表现与膝关节疼痛程度的相关性.方法:为103例膝骨关节炎患者拍摄正位和侧位膝关节数字透视摄影片,测定膝关节内侧间距、外侧间距、内外侧间距比值,并对膝关节骨赘进行评分.同时采用视觉模拟评分法评定膝关节疼痛程度.对膝关节X线表现与膝关节疼痛评分进行相关性分析.结果:本组患者膝关节疼痛评分为(7.49±1.23)分;膝关节内侧间距(38.02±9.53) mm,外侧间距(48.01±10.59) mm,内外侧间距比值(1.33±0.37)%;膝关节骨赘评分,外侧区(0.33±0.47)分,中间区(0.81±0.40)分,内侧区(0.34±0.48)分,髌股区(0.75±0.44)分,总分(2.22±1.21)分;无骨赘者9例,1个部位出现骨赘者20例,2个部位出现骨赘者32例,3个部位出现骨赘者23例,4个部位出现骨赘者19例.相关性分析结果显示,膝关节中间区骨赘评分和髌股区骨赘评分与膝关节疼痛评分呈正相关(r =0.203,P=0.014;r=0.177,P=0.032).结论:膝骨关节炎患者的膝关节中间区和髌股区骨赘是影响膝关节疼痛程度的主要解剖因素.%Objective:To analyse the correlation between X-ray manifestation and knee pain degree in knee osteoarthritis (KOA).Methods:The frontal and lateral digital radiograph of knee joints of 103 patients with KOA were used to assess such parameters as the medial joint space width,lateral joint space width and the ratio of medial joint space width to lateral joint space width,and the knee joint osteophytes were measured and scored.Meanwhile,the degree of knee joint pain were measured by using a visual analogue scale.Then,the relationship between X-ray manifestation and knee joint pain score were analysed by correlation analysis.Results:The knee joint pain scores of the patients were (7.49 ± 1.23).The medial joint space width,lateral joint space width and the ratio of medial joint space width to lateral joint space width were (38.02 ± 9.53) mm,(48.01 ± 10.59) mm,(1

  4. Reference guide to WPP version 2.0

    Energy Technology Data Exchange (ETDEWEB)

    Petersson, A; Sjogreen, B

    2010-01-22

    WPP is a computer program for simulating seismic wave propagation on parallel machines. WPP solves the governing equations in second order formulation using a node-based finite difference approach. The basic numerical method is described in [9]. WPP implements substantial capabilities for 3-D seismic modeling, with a free surface condition on the top boundary, non-reflecting far-field boundary conditions on the other boundaries, point force and point moment tensor source terms with many predefined time dependencies, fully 3-D heterogeneous material model specification, output of synthetic seismograms in the SAC [4] format, output of GMT [11] scripts for laying out simulation information on a map, and output of 2-D slices of (derived quantites of) the solution field as well as the material model. Version 2.0 of WPP allows the free surface boundary condition to be imposed on a curved topography. For this purpose a curvilinear mesh is used near the free surface, extending into the computational domain down to a user specified level. The elastic wave equations and the free surface boundary conditions are discretized on the curvilinear mesh using the energy conserving technique described in [2]. A curvilinear mesh generator is built into WPP and the curvilinear mesh is automatically generated from the topography. Below the curvilinear grid, the elastic wave equation is discretized on Cartesian meshes, which leads to a more computationally efficient algorithm. In version 2.0 of WPP, Cartesian local mesh refinement can be used to make the computational mesh finer near the free surface, where more resolution often is needed to resolve short wave lenghts in the solution, for example in sedimentary basins. The mesh refinement is performed in the vertical direction and each Cartesian grid is constructed from user specified refinement levels. In this approach, the grid size in all three spatial directions is doubled across each mesh refinement interface, leading to substantial

  5. Thyrotropin binding to porcine thyroid plasma membranes: kinetic and thermodynamic analyses.

    Science.gov (United States)

    Saltiel, A R; Thomas, C G; Nayfeh, S N

    1982-01-01

    Evaluation of TSH binding to plasma membranes of porcine thyroid revealed unique sensitivity to pH and temperature. Analysis of apparent equilibrium binding yielded a linear Scatchard plot at the optimal pH of 6.0, indicating one class of binding sites. At physiological pH 7.4 a curvilinear Scatchard plot was obtained, resolved by computer analysis into two classes of binding sites of different affinities and capacities. Treatment of membranes with phospholipase C resulted in a 20% decrease in the number of high affinity sites, but no change occurred in binding affinity. In contrast, low affinity sites were not altered. To evaluate the significance of the curvilinear Scatchard plot, the kinetics of association were examined. The intrinsic Kd (kd/ka) was 0.20 nM, a value essentially equivalent to that of the high affinity binding component. The 'negative cooperativity' model of hormone binding was evaluated by examining the effect of excess unlabeled TSH on dissociation rate. Dissociation of bound 125I-labeled TSH was biphasic, and was enhanced by unlabeled hormone, regardless of whether the membranes were prelabeled at pH 6.0 or 7.4. This effect was not correlated with curvilinear Scatchard plots, and therefore not proof of negative cooperativity. Binding sites for TSH were further distinguished by their sensitivity to temperature. A van't Hoff plot of temperature dependence of the apparent Kd of the high affinity site was linear from 4 to 37 degrees C. In contrast, the apparent Kd of low affinity binding did not vary with respect to temperature. These results demonstrate that there are at least two independent binding sites for TSH on porcine thyroid plasma membranes, distinguishable by their equilibrium binding properties.

  6. The impact of nursing care and other healthcare attributes on hospitalized patient satisfaction and behavioral intentions.

    Science.gov (United States)

    Otani, Koichiro; Kurz, Richard S

    2004-01-01

    Healthcare organizations in the United States are struggling to find ways to survive in their uncertain and competitive environments. One of the survival strategies used by those organizations is to increase patient satisfaction. This article presents research on factors that influence hospitalized patients' satisfaction and their intention to return to and recommend the hospital. The first objective of this study was to find out, using a comprehensive set of healthcare attributes, which attributes play a more important role in increasing patient satisfaction and behavioral intentions. The second objective was to analyze the relative importance of those attributes and the nature of the relationships across the values of the attributes. More specifically, this study attempted to identify any existing curvilinear relationships among these variables. If any curvilinear relationships exist, do they show an increasing or a decreasing marginal-utility function? Included in this article is an example, featuring a hospital-discharged patient, that explains the importance and uniqueness of this curvilinear relationship. This study found that among six attributes, nursing care showed the largest parameter estimate for the patient satisfaction and behavioral intentions models. Thus, simply improving the nursing care attribute seems to be the most effective manner to enhancing patient satisfaction and behavioral intentions. However, nursing care also showed a diminishing marginal-utility function for both models. To assess the effect of this diminishing marginal-utility function, the impact of nursing care was computed for each unit of improvement together with other attributes. The finding from this study provides information needed to increase patient satisfaction and behavioral intentions and should result in more effective and efficient healthcare management.

  7. The relationship between elderly suicide rates and different components of education: a cross-national study

    Directory of Open Access Journals (Sweden)

    Ajit Shah

    2012-07-01

    Full Text Available BACKGROUND: Two recent studies reported a curvilinear (U-shaped between elderly suicide rates and educational attainment measured by the United Nation’s Education Index. A study examining the curvilinear (U-shaped relationship between elderly suicide rates and the individual components of the Education Index (adult literacy rate, percentage of children of relevant age group enrolled in primary schools and percentage of children of relevant age group enrolled for secondary schools and one other measure of educational attainment (youth literacy rate was undertaken to partial out the effects of the individual components of Education Index on elderly suicides. METHODS: A cross-national study examining the relationship between elderly suicide rates (Y-axis and different measures of educational attainment (X-axis was undertaken using data from the World Health Organization and the United Nations data banks using Curve estimation regression models. RESULTS: The relationship between elderly suicide rates with the adult literacy rate, the percentage of children of relevant age group enrolled for secondary schools and the youth literacy rate was curvilinear (U-shaped curve. This relationship was absent with the percentage of children of relevant age group enrolled in primary schools. CONCLUSIONS: Given the cross-sectional study design, a causal relationship between elderly suicide rates and measures of educational attainment, including the adult literacy rate, the percentage of children of relevant age group enrolled for secondary schools and the youth literacy rate, cannot be assumed. However, the findings suggest that future studies of elderly suicide rates and educational attainment should focus on the adult literacy rate, the percentage of children of relevant age group enrolled for secondary schools and the youth literacy rate as measures of educational attainment.

  8. Evaluating conducting network based transparent electrodes from geometrical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ankush [Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, 560064 Bangalore (India); Kulkarni, G. U., E-mail: guk@cens.res.in [Centre for Nano and Soft Matter Sciences, 560013 Bangalore (India)

    2016-01-07

    Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained from conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in

  9. Sperm treatment affects capacitation parameters and penetration ability of ejaculated and epididymal boar spermatozoa.

    Science.gov (United States)

    Matás, C; Sansegundo, M; Ruiz, S; García-Vázquez, F A; Gadea, J; Romar, R; Coy, P

    2010-11-01

    This work was designed to study how this ability is affected by different sperm treatments routinely used for in vitro fertilization (IVF) assay. In this study, boar sperm samples from epididymal or ejaculated origin were processed by three different methods: left unwashed (NW group), washed in Dulbecco's phosphate-buffered saline supplemented with 0.1% BSA (BSA group), and washed on a Percoll(®) gradient (PERCOLL group). After preparation of semen samples, changes in motility patterns were studied by CASA, calcium uptake by spectrofluorimetry, and ROS generation, spontaneous acrosome reaction, and lipid disorder by means of flow cytometry. Finally IVF assays were also performed with the different semen samples and penetrability results evaluated at 2 and 4 h post insemination (hpi). Independently of the sperm treatment, epididymal spermatozoa showed higher values of progressive motility, percentage of live cells with low lipid disorder, and penetration ability at 4 hpi than the corresponding ejaculated spermatozoa. Ejaculated spermatozoa showed higher levels of calcium uptake, ROS generation and percentage of spontaneous acrosome reaction than epididymal sperm. Regarding sperm treatments, PERCOLL group showed the highest values for some motility parameters (linearity of the curvilinear trajectory, straightness, and average path velocity/curvilinear velocity), ROS generation and penetration ability at 2 and 4 hpi; however this same group showed the lowest values for sperm curvilinear velocity and lateral head displacement. From all experimental groups, ejaculated-PERCOLL-treated spermatozoa showed the highest fertilization ability after 2 hpi. Results suggest that capacitation pathways can be regulated by suitable treatments making the ejaculated sperm able to reach capacitation and fertilize oocytes in similar levels than epididymal spermatozoa, although most of the studied capacitation-associated changes do not correlate with this ability.

  10. Geologic map of the MTM 85200 quadrangle, Olympia Rupes region of Mars

    Science.gov (United States)

    Skinner, James A.; Herkenhoff, Kenneth E.

    2012-01-01

    The north polar region of Mars is dominated by Planum Boreum, a roughly circular, domical plateau that rises >2,500 m above the surrounding lowland. Planum Boreum is >1,500 km in diameter, contains deep, curvilinear troughs and chasmata, isolated cavi, and marginal scarps and slopes. The north polar plateau is surrounded by low-lying and nearly horizontal plains of various surface texture, geologic origin, and stratigraphic significance. The MTM 85200 quadrangle spans 5° of latitude (lat 82.5° to 87.5° N.) and 40° of longitude (long 140° to 180° E.) within the eastern hemisphere of Mars. The quadrangle includes the high-standing Planum Boreum, curvilinear troughs of Boreales Scopuli, deep, sinuous scarps of Olympia Rupes, isolated and coalesced depressions of Olympia Cavi, margins of the circular polar erg Olympia Undae, and low-standing Olympia Planum. The surface of Planum Boreum within the MTM 85200 quadrangle is characterized by smoothly sculptured landforms with shallow slopes and variable relief at kilometer scales. Areas that are perennially covered with bright frost are generally smooth and planar at 100-m scales. However, MGS MOC and MRO HiRISE images show that much of the icy polar plateau is rough at decameter scale. The Martian polar plateaus are likely to contain a record of global climate history for >107 to as much as ~3 x 109 years. This record is partly observable as rhythmically layered deposits exposed in the curvilinear troughs of the north polar plateau, Planum Boreum. The north polar layered deposits are widely interpreted to be among the most youthful bedrock deposits on the Martian surface. These materials and their stratigraphic and structural relations provide a glimpse into some of the more recent geologic processes that have occurred on Mars. The ability of the massive polar deposits to periodically trap and release both volatiles and lithic particles may represent a globally important, recurring geologic process for Mars.

  11. Tracing the Chromospheric and Coronal Magnetic Field with AIA, IRIS, IBIS, and ROSA Data

    Science.gov (United States)

    Aschwanden, Markus J.; Reardon, Kevin; Jess, Dave B.

    2016-07-01

    The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolution images (≈ 0\\buildrel{\\prime\\prime}\\over{.} 2{--}0\\buildrel{\\prime\\prime}\\over{.} 3), from the Interferometric Bidimensional Spectrometer in the Ca ii 8542 Å line, the Rapid Oscillations in the Solar Atmosphere instrument in the Hα 6563 Å line, the Interface Region Imaging Spectrograph in the 2796 Å line, and compare non-potential magnetic field models obtained from those chromospheric images with those obtained from images of the Atmospheric Imaging Assembly in coronal (171 Å, etc.) and in chromospheric (304 Å) wavelengths. Curvi-linear structures are automatically traced in those images with the OCCULT-2 code, to which we forward-fitted magnetic field lines computed with the Vertical-current Approximation Nonlinear Force Free Field code. We find that the chromospheric images: (1) reveal crisp curvi-linear structures (fibrils, loop segments, spicules) that are extremely well-suited for constraining magnetic modeling; (2) that these curvi-linear structures are field-aligned with the best-fit solution by a median misalignment angle of {μ }2≈ 4^\\circ -7° (3) the free energy computed from coronal data may underestimate that obtained from cromospheric data by a factor of ≈ 2-4, (4) the height range of chromospheric features is confined to h≲ 4000 km, while coronal features are detected up to h = 35,000 km; and (5) the plasma-β parameter is β ≈ {10}-5{--}{10}-1 for all traced features. We conclude that chromospheric images reveal important magnetic structures that are complementary to coronal images and need to be included in comprehensive magnetic field models, something that is currently not accomodated in standard NLFFF codes.

  12. Nursing students' post-traumatic growth, emotional intelligence and psychological resilience.

    Science.gov (United States)

    Li, Y; Cao, F; Cao, D; Liu, J

    2015-06-01

    Nursing students in the present sample who have experienced childhood adversity have a certain level of post-traumatic growth. If introduced into nursing curricula, emotional intelligence interventions may increase emotional coping resources and enhance social skills for nurses, which may benefit their long-term occupational health. As researchers consider personal resilience a strategy for responding to workplace adversity in nurses, resilience building should be incorporated into nursing education. This is a preliminary study that may guide future investigations of the curvilinear relationship rather than linear relationship between post-traumatic growth and positive factors in the special sample of nursing students. Resilience, emotional intelligence and post-traumatic growth may benefit nursing students' careers and personal well-being in clinical work. Developing both their emotional intelligence and resilience may assist their individual post-traumatic growth and enhance their ability to cope with clinical stress. To investigate the relationships among post-traumatic growth, emotional intelligence and psychological resilience in vocational school nursing students who have experienced childhood adversities, a cross-sectional research design with anonymous questionnaires was conducted and self-report data were analysed. The Childhood Adversities Checklist (Chinese version), Posttraumatic Growth Inventory, Emotional Intelligence Scale and the 10-item Connor-Davidson Resilience Scale were used. Survey data were collected from 202 Chinese vocational school nursing students during 2011. Post-traumatic growth was associated with emotional intelligence and psychological resilience. Results indicated a curvilinear relationship between emotional intelligence and post-traumatic growth, and between psychological resilience and post-traumatic growth. Moderate-level emotional intelligence and psychological resilience were most associated with the greatest levels of growth

  13. ASSESSMENT OF HYDROCARBON SEEPAGE DETECTION METHODS ON THE FORT PECK RESERVATION, NORTHEAST MONTANA

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence M. Monson

    2003-06-30

    Surface exploration techniques have been employed in separate study areas on the Fort Peck Reservation in northeastern Montana. Anomalies associated with hydrocarbon seepage are documented in all three areas and a variety of surface exploration techniques can be compared. In a small area with established production, Head Gas and Thermal Desorption methods best match production; other methods also map depletion. In a moderate-size area that has prospects defined by 3D seismic data, Head Gas along with Microbial, Iodine, and Eh soil anomalies are all associated with the best hydrocarbon prospect. In a large area that contains many curvilinear patterns observed on Landsat images, that could represent micro-seepage chimneys, results are inconclusive. Reconnaissance mapping using Magnetic Susceptibility has identified a potential prospect; subsequent Soil Gas and Head Gas surveys suggest hydrocarbon potential. In the final year of this project the principle contractor, the Fort Peck Tribes, completed a second survey in the Wicape 3D Seismic Prospect Area (also known as Area 6 in Phase I of the project) and sampled several Landsat image features contained in the Smoke Creek Aeromag Anomaly Area (also known as Area 1 in Phase II of the project). Methods determined to be most useful in Phases I and II, were employed in this final Phase III of the study. The Southwest Wicape seismic anomaly was only partially confirmed. The abundant curvilinears proposed to be possible hydrocarbon micro-seepage chimneys in the Smoke Creek Area were not conclusively verified as such. Insufficient sampling of background data precludes affirmative identification of these mostly topographic Landsat features as gas induced soil and vegetation anomalies. However relatively higher light gas concentrations were found associated with some of the curvilinears. Based on the findings of this work the Assiniboine & Sioux Tribes of the Fort Peck Reservation intend to utilize surface hydrocarbon

  14. A MULTICENTER, BLIND, RANDOMIZED, PLACEBO-CONTROLLED STUDY OF THE SYMPTOM- AND STRUCTURE-MODIFYING EFFET OF ALFLUTOP IN PATIENTS WITH KNEE OSTEOARTHRITIS. REPORT 2: THE ASSESSMENT OF THE STRUCTURE-MODIFYING EFFECT OF THE DRUG

    Directory of Open Access Journals (Sweden)

    L. I. Alekseeva

    2014-01-01

    Full Text Available Objective. To evaluate the symptom- and structure-modifying effect of Alflutop compared to placebo (PL in patients with knee osteoarthritis (OA. Material and methods. The study included 90 patients with knee OA (according to the criteria of the Russian Association of Rheumatologists at the stage 2–3 (according to the Kellgren-Lawrence scale; pain score when walk- ing ≥ 40 mm (assessed using the visual analog scale. All the patients provided an informed consent. The patients were randomly divided into two groups: group 1 (n=45 received an intramuscular injection of 1 mL Alflutop for 20 days with 6-month intervals for 2 years (a total of 4 courses for 2 years; group 2 (n=45 received an injection of PL (iso- tonic sodium chloride solution in the same way. Ibuprofen at a dose of 600–1200 mg/day was administered as concomitant therapy. To evaluate the structure-modifying effect of Alflutop, X-ray of the knee joint was performed at the beginning and end of the study; the level of biochemical markers (CTX-II and COMP was determined at the beginning, after 3 months, and at the end of the study. A statistical analysis was performed using the Statistica 10 software package.Results. After the 2-year follow-up, a statistically significant negative trend was detected less frequently in the group of patients treated with Alflutop compared to the PL group (6.1 and 38.4%, respectively. The statistically significant delay in joint space narrowing was observed in patients who received Alflutop in contrast to patients who received PL (the numerical score of the joint space, the Wilcoxon test; p=0.0003. An increase in osteo- phyte size was observed in 72% of the patients receiving PL, and only in 27% of the patients receiving Alflutop (medial and lateral osteophytes of the femoral bone, the Wilcoxon test; p=0.0078; medial and lateral osteophytes of the shin bone, the Wilcoxon test; p=0.0001 and p=0.0039, respective- ly. Augmentation of subchondral

  15. Geometry for web microwave heating or drying to a desired profile in a waveguide

    Science.gov (United States)

    Habeger, Jr., Charles C.; Patterson, Timothy F.; Ahrens, Frederick W.

    2005-11-15

    A microwave heater and/or dryer has a nonlinear or curvilinear relative slot profile geometry. In one embodiment, the microwave dryer has at least one adjustable field modifier making it possible to change the geometry of the heater or dryer when drying different webs. In another embodiment, the microwave dryer provides more uniform drying of a web when the field modifier is adjusted in response to a sensed condition of the web. Finally, a method of microwave heating and/or drying a web achieves a uniform heating and/or drying profile.

  16. The discrete ordinate method in association with the finite-volume method in non-structured mesh; Methode des ordonnees discretes associee a la methode des volumes finis en maillage non structure

    Energy Technology Data Exchange (ETDEWEB)

    Le Dez, V.; Lallemand, M. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France); Sakami, M.; Charette, A. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees

    1996-12-31

    The description of an efficient method of radiant heat transfer field determination in a grey semi-transparent environment included in a 2-D polygonal cavity with surface boundaries that reflect the radiation in a purely diffusive manner is proposed, at the equilibrium and in radiation-conduction coupling situation. The technique uses simultaneously the finite-volume method in non-structured triangular mesh, the discrete ordinate method and the ray shooting method. The main mathematical developments and comparative results with the discrete ordinate method in orthogonal curvilinear coordinates are included. (J.S.) 10 refs.

  17. Nonlinear radiative heat transfer and Hall effects on a viscous fluid in a semi-porous curved channel

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Z.; Naveed, M., E-mail: rana.m.naveed@gmail.com [Department of Mathematics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Sajid, M. [Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan)

    2015-10-15

    In this paper, effects of Hall currents and nonlinear radiative heat transfer in a viscous fluid passing through a semi-porous curved channel coiled in a circle of radius R are analyzed. A curvilinear coordinate system is used to develop the mathematical model of the considered problem in the form partial differential equations. Similarity solutions of the governing boundary value problems are obtained numerically using shooting method. The results are also validated with the well-known finite difference technique known as the Keller-Box method. The analysis of the involved pertinent parameters on the velocity and temperature distributions is presented through graphs and tables.

  18. Impact of light intensity on flowering time and plant quality of Antirrhinum majus L.cultivar Chimes White

    Institute of Scientific and Technical Information of China (English)

    MUNIR Muhammad; JAMIL Muhammad; BALOCH Jalal-ud-din; KHATTAK Khalid Rehman

    2004-01-01

    Shades of different light intensities (29%, 43%, 54%, 60% or 68%) along with control (no shade) were studied to observe their effects on the flowering time and plant quality. A hyperbolic relationship was observed between different light intensities under shade, and time to flowering. The total number of flower buds showed a curvilinear relationship with light intensities. Growth parameters related to the plant characteristics such as plant height, leaf area and plant fresh weight were improved under shading treatments at the expense of flowering time and number of flower buds. However, both linear and polynomial models applied assumed that cultivar Chimes White was equally sensitive to light intensity throughout development.

  19. Preferential access to emotion under attentional blink: evidence for threshold phenomenon

    Directory of Open Access Journals (Sweden)

    Szczepanowski Remigiusz

    2015-03-01

    Full Text Available The present study provides evidence that the activation strength produced by emotional stimuli must pass a threshold level in order to be consciously perceived, contrary to the assumption of continuous quality of representation. An analysis of receiver operating characteristics (ROC for attentional blink performance was used to distinguish between two (continuous vs. threshold models of emotion perception by inspecting two different ROC’s shapes. Across all conditions, the results showed that performance in the attentional blink task was better described by the two-limbs ROC predicted by the Krantz threshold model than by the curvilinear ROC implied by the signal-detection theory.

  20. Intrinsic and extrinsic motivational orientations in the competitive context: an examination of person-situation interactions.

    Science.gov (United States)

    Abuhamdeh, Sami; Csikszentmihalyi, Mihaly

    2009-10-01

    The current study examined Intrinsic Motivation Orientation and Extrinsic Motivation Orientation (Work Preference Inventory; Amabile, Hill, Hennessey, & Tighe, 1994) as potential trait-level moderators of the way Internet chess players responded to the intrinsic and extrinsic rewards of the chess games they played. On the basis of the defining characteristics of these 2 types of motivational orientations, we predicted that (a) Intrinsic Motivation Orientation would be associated with a stronger curvilinear relationship between challenge and enjoyment and (b) Extrinsic Motivation Orientation would be associated with a heightened affective responsivity to competitive outcome (i.e., winning vs. losing). Results supported the predictions. Implications of the findings are discussed.

  1. Power as the Cause of Motion and a New Foundation of Classical Mechanics

    OpenAIRE

    Harokopos E.

    2005-01-01

    Laws of motion are derived based on power rather than on force. I show how power extends the law of inertia to include curvilinear motion and I also show that the law of action-reaction can be expressed in terms of the mutual time rate of change of kinetic energies instead of mutual forces. I then compare the laws of motion based on power to Newton’s Laws of Motion and I investigate the relation of power to Leibniz’s notion of vis viva. I also discuss briefly how the metaphysics of power a...

  2. Aeroelastic Tailoring of Transport Wings Including Transonic Flutter Constraints

    Science.gov (United States)

    Stanford, Bret K.; Wieseman, Carol D.; Jutte, Christine V.

    2015-01-01

    Several minimum-mass optimization problems are solved to evaluate the effectiveness of a variety of novel tailoring schemes for subsonic transport wings. Aeroelastic stress and panel buckling constraints are imposed across several trimmed static maneuver loads, in addition to a transonic flutter margin constraint, captured with aerodynamic influence coefficient-based tools. Tailoring with metallic thickness variations, functionally graded materials, balanced or unbalanced composite laminates, curvilinear tow steering, and distributed trailing edge control effectors are all found to provide reductions in structural wing mass with varying degrees of success. The question as to whether this wing mass reduction will offset the increased manufacturing cost is left unresolved for each case.

  3. An Affine Scaling Interior Trust Region Method via Optimal Path for Solving Monotone Variational Inequality Problem with Linear Constraints

    Institute of Scientific and Technical Information of China (English)

    Yunjuan WANG; Detong ZHU

    2008-01-01

    Based on a differentiable merit function proposed by Taji et al.in "Math.Prog. Stud.,58,1993,369-383",the authors propose an affine scaling interior trust region strategy via optimal path to modify Newton method for the strictly monotone variational inequality problem subject to linear equality and inequality constraints.By using the eigensystem decomposition and affine scaling mapping,the authors form an affine scaling optimal curvilinear path very easily in order to approximately solve the trust region subproblem.Theoretical analysis is given which shows that the proposed algorithm is globally convergent and has a local quadratic convergence rate under some reasonable conditions.

  4. Radiation from charges in the continuum limit

    Energy Technology Data Exchange (ETDEWEB)

    Ianconescu, Reuven [Shenkar College of Engineering and Design, Ramat Gan 52526 (Israel)

    2013-06-15

    It is known that an accelerating charge radiates according to Larmor formula. On the other hand, any DC current following a curvilinear path, consists of accelerating charges, but in such case the radiated power is 0. The scope of this paper is to analyze and quantify how a system of charges goes from a radiating state to a non radiating state when the charges distribution goes to the continuum limit. Understanding this is important from the theoretical point of view and the results of this work are applicable to particle accelerator, cyclotron and other high energy devices.

  5. Shape determination of unidimensional objects: the virtual image correlation method

    OpenAIRE

    Auradou H.; Vatteville J.; Semin B.; Francois M.

    2010-01-01

    The proposed method, named Virtual Image Correlation, allows one to identify an analytical expression of the shape of a curvilinear object from its image. It uses a virtual beam, whose curvature field is expressed as a truncated mathematical series. The virtual beam width only needs to be close to the physical one; its gray level (in the transverse direction) is bell-shaped. The method consists in finding the coefficients of the series for which the correlation between physical and virtual ...

  6. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

    Directory of Open Access Journals (Sweden)

    John R. Eisenbrey

    2015-01-01

    Full Text Available Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency, subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  7. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound.

    Science.gov (United States)

    Eisenbrey, John R; Sridharan, Anush; Liu, Ji-Bin; Forsberg, Flemming

    2015-01-01

    Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  8. Unsteady flow volumes

    Energy Technology Data Exchange (ETDEWEB)

    Becker, B.G.; Lane, D.A.; Max, N.L.

    1995-03-01

    Flow volumes are extended for use in unsteady (time-dependent) flows. The resulting unsteady flow volumes are the 3 dimensional analog of streamlines. There are few examples where methods other than particle tracing have been used to visualize time varying flows. Since particle paths can become convoluted in time there are additional considerations to be made when extending any visualization technique to unsteady flows. We will present some solutions to the problems which occur in subdivision, rendering, and system design. We will apply the unsteady flow volumes to a variety of field types including moving multi-zoned curvilinear grids.

  9. Transport phenomena in a high pressure crystal growth system: In situ synthesis for InP melt

    Science.gov (United States)

    Zhang, H.; Prasad, V.; Anselmo, A. P.; Bliss, D. F.; Iseler, G.

    1997-06-01

    The physical phenomena underlying the "one-step" in situ synthesis and high pressure growth of indium phosphide crystals are complex. A high resolution computer model based on multizone adaptive grid generation and curvilinear finite volume discretization is used to predict the flow and temperature fields during the synthesis of the InP melt. Simulations are performed for a range of parameters, including Grashof number, crucible rotation, and location of the injector. These parameters affect the gas flow in a high pressure liquid-encapsulated Czochralski (HPLEC) furnace significantly, and have a strong influence on the melt synthesis and its control.

  10. Trends in mask data preparation

    Science.gov (United States)

    Fujimura, Aki; Pang, Liyong; Su, Bo; Choi, Yohan

    2014-10-01

    Whether for VSB mask writing or for multibeam mask writing, the shapes we need to write on masks are increasingly complex, increasingly curvilinear, and smaller in minimum width and space. The overwhelming trend in mask data preparation (MDP) is the shift from deterministic, rule-based, geometric, context-independent, shape-modulated, rectangular processing to statistical, simulation-based, context-dependent, dose- and shape-modulated any-shape processing. The paper briefly surveys the history of MDP, and explains through a simulation-based study that 50nm line and space is the tipping point where rule-based processing gives away to simulation-based processing.

  11. Finite volume methods for the incompressible Navier-Stokes equations on unstructured grids

    Energy Technology Data Exchange (ETDEWEB)

    Meese, Ernst Arne

    1998-07-01

    Most solution methods of computational fluid dynamics (CFD) use structured grids based on curvilinear coordinates for compliance with complex geometries. In a typical industry application, about 80% of the time used to produce the results is spent constructing computational grids. Recently the use of unstructured grids has been strongly advocated. For unstructured grids there are methods for generating them automatically on quite complex domains. This thesis focuses on the design of Navier-Stokes solvers that can cope with unstructured grids and ''low quality grids'', thus reducing the need for human intervention in the grid generation.

  12. IMAGING DIAGNOSIS--USE OF RADIOGRAPHY AND COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF A MINERALIZED YOLK SAC IN A BROWN KIWI (APTERYX MANTELLI).

    Science.gov (United States)

    Wightman, Paul; Cohen, Eli B; Hunter, Stuart; Gartrell, Brett

    2015-01-01

    A 12-day-old Brown Kiwi (Apteryx mantelli) was presented with anorexia, torticollis, head-tilt, and coelomic distension. Radiographs showed an ill-defined, fat-opaque, coelomic mass displacing viscera craniodorsally. Curvilinear mineral opacities were superimposed over the ventral aspect of the mass. Computed tomography demonstrated the presence of mineral within the periphery of a fat attenuating mass consistent with a retained yolk sac. A deutectomy (yolk sac excision) was performed. Histopathology of the excised tissue confirmed the diagnosis of a retained yolk sac with multifocal mineralization.

  13. Construction of generalized magnetic coordinates by B-spline expansion

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, Michinari [Dept. of Energy Engineering and Science, Graduate School of Engineering, Nagoya Univ., Nagoya, Aichi (Japan); Todoroki, Jiro [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-06-01

    Generalized Magnetic Coordinates (GMC) are curvilinear coordinates ({xi},{eta},{zeta}) in which the magnetic field is expressed in the form B={nabla}{psi}({xi},{eta},{zeta}) x {nabla}{zeta} + H{sup {zeta}}({xi},{eta}){nabla}{xi} x {nabla}{eta}. The coordinates are expanded in Fourier series in the toroidal direction and the B-spline function in other two dimensions to treat the aperiodic model magnetic field. The coordinates are well constructed, but are influenced by the boundary condition in the B-spline expansion. (author)

  14. Less crime, more punishment.

    Science.gov (United States)

    Cooney, Mark; Burt, Callie Harbin

    2008-09-01

    Recasting Durkheim's "community of saints" thesis, the authors argue that the severity of punishment is predicted in part by the prevalence of the deviant behavior of which the deviant stands accused. Although there is some curvilinearity at low levels of prevalence, the relationship is generally negative. Thus, all else equal, where a particular crime is frequent, any punishment applied to it is likely to be mild; conversely, where a crime is infrequent, its punishment ought to be severe. Using hierarchical regression models, the authors support this hypothesis with 1988 homicide conviction and imprisonment decisions in 32 U.S. counties.

  15. Eddy currents in the vacuum vessel of the ETE spherical tokamak

    Science.gov (United States)

    Ludwig, G. O.; DelBosco, E.; Ferreira, J. G.

    2005-07-01

    A Green's function method is developed to evaluate the currents induced during startup in the vacuum vessel of ETE (Experimento Tokamak Esférico). The non-homogeneous integral equation for the axisymmetric eddy currents distribution is determined using a thin shell approximation for the vacuum vessel and local curvilinear coordinates. This problem is reduced to a circuit model by adopting spectral representations both for the centreline of the vacuum vessel and the surface current density. Results of this model are compared with the distribution of eddy currents measured in ETE.

  16. Navier-Stokes computations of separated vortical flows past prolate spheroid at incidence

    Science.gov (United States)

    Wong, Tin-Chee; Kandil, Osama A.; Liu, C. H.

    1989-01-01

    The problem of steady incompressible viscous flow past prolate spheroids at incidence is formulated using the unsteady incompressible and compressible thin-layer Navier-Stokes equations. The two sets of Navier-Stokes equations are solved using a pseudotime stepping of the implicit flux-difference splitting scheme on a curvilinear grid, which is generated by a transfinite grid generator. The Baldwin and Lomax (1978) algebraic eddy-viscosity model is used to model the turbulent flow. The computational applications cover a 6:1 prolate spheroid at different angles of attack and Reynolds numbers. The results are compared with experimental data.

  17. Self organized locomotion via polyhedral geometry: a minimal example

    CERN Document Server

    Ghosh, Shankar; Bhattacharya, S; Nitsure, Nitin

    2016-01-01

    In this paper we establish a geometrical route to self-organisation. We show that the relevant underlying geometry of the configuration space is a curvilinear polyhedral region. The energetics over the polyhedral region localizes the available space within the close proximity of a corner of this polyhedra. This results into a stronger entrapment of the state which provides it the observed geometrical shape, functionality, and maintains its stability. These theoretical considerations are borne out in the experiments where we study the case of an uphill locomotion of a self organised dumbbell pair placed in a rotating cylinder.

  18. 等参谱元方法的研究%RESEARCH OF AN ISOPARAMETRIC SPECTRAL ELEMENT METHOD

    Institute of Scientific and Technical Information of China (English)

    陈雪江; 秦国良; 徐忠

    2003-01-01

    An isoparametric spectral element method that combines the idea of the isopara-metric element in finite element methods with spectral element methods is pro-posed. The computational domain is broken up into curvilinear quadrangular ele-ments to approach boundaries more specifically and solve the differential equation in complex geometry. By this means both the Helmholtz equations with rect-angular geometry and the Poisson's equations with annular geometry those have analytical solutions are solved. The predicted results are in excellent agreement with the analytical solutions.

  19. Complex variable methods in elasticity

    CERN Document Server

    England, A H

    2003-01-01

    The plane strain and generalized plane stress boundary value problems of linear elasticity are the focus of this graduate-level text, which formulates and solves these problems by employing complex variable theory. The text presents detailed descriptions of the three basic methods that rely on series representation, Cauchy integral representation, and the solution via continuation. Its five-part treatment covers functions of a complex variable, the basic equations of two-dimensional elasticity, plane and half-plane problems, regions with circular boundaries, and regions with curvilinear bounda

  20. GRID GENERATION AND NUMERICAL SIMULATION OF 2-D RIVER FLOW GRID GENERATION AND NUMERICAL SIMULATION OF 2-D RIVER FLOW

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents new weighting functions in grid generation and new discretizing scheme of momentum equations in numerical simulation of river flow. By using the new weighting functions, the curvilinear grid could be concentrated as desired near the assigned points or lines in physical plane. By using the new discretizing scheme, the difficulties caused by movable boundary and dry riverbed can be overcome. As an application, the flow in the Wuhan Section of Yangtze River is simulated. The computational results are in good agreement with the measured results. The new method is applicable to the numerical simulation of 2-D river flow with irregular region and moveable boundary.