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Sample records for caudolateral curvilinear osteophyte

  1. Cervical osteophyte induced dysphagia

    International Nuclear Information System (INIS)

    Davies, R.P.; Sage, M.R.; Brophy, B.P.

    1989-01-01

    Although cervical spondylosis is a common disorder, dysphagia induced by osteophyte formation is uncommon. Fewer than one hundred cases of cervical osteophyte induced dysphagia have been reported, with little attention to the diagnosis by barium swallow. The radiological features of two cases treated surgically with good results are described. Both cases complained of dysphagia while one had associated respiratory obstruction on forward flexion of his neck. The features on barium study of cervical osteophytes causing dysphagia include deformity at the level of osteophyte formation, in both AP and lateral projections. Tracheal aspirations due to deformity at the laryngeal inlet and interference with epiglottic retroversion may be present. 8 refs., 3 figs

  2. Prepulse Inhibition of Auditory Cortical Responses in the Caudolateral Superior Temporal Gyrus in Macaca mulatta.

    Science.gov (United States)

    Chen, Zuyue; Parkkonen, Lauri; Wei, Jingkuan; Dong, Jin-Run; Ma, Yuanye; Carlson, Synnöve

    2018-04-01

    Prepulse inhibition (PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the PPI of cortical responses. We recorded local field potentials (LFPs) in four monkeys and investigated whether the PPI of auditory cortical responses (alpha, beta, and gamma oscillations and evoked potentials) can be demonstrated in the caudolateral belt of the superior temporal gyrus (STGcb). We also investigated whether the presence of a conspecific, which draws attention away from the auditory stimuli, affects the PPI of auditory cortical responses. The PPI paradigm consisted of Pulse-only and Prepulse + Pulse trials that were presented randomly while the monkey was alone (ALONE) and while another monkey was present in the same room (ACCOMP). The LFPs to the Pulse were significantly suppressed by the Prepulse thus, demonstrating PPI of cortical responses in the STGcb. The PPI-related inhibition of the N1 amplitude of the evoked responses and cortical oscillations to the Pulse were not affected by the presence of a conspecific. In contrast, gamma oscillations and the amplitude of the N1 response to Pulse-only were suppressed in the ACCOMP condition compared to the ALONE condition. These findings demonstrate PPI in the monkey STGcb and suggest that the PPI of auditory cortical responses in the monkey STGcb is a pre-attentive inhibitory process that is independent of attentional modulation.

  3. Osteophytes - an alternative source of chondrocytes for ...

    African Journals Online (AJOL)

    Materials and Methods: The scrapings from the cartilage mantle of osteophytes harvested during routine total knee replacement for osteoarthritis were enzymatically digested and grown in monolayer culture. Articular cartilage scrapings obtained from visually normal area of the femoral condyle (usually from the posterior ...

  4. Path integrals in curvilinear coordinates

    International Nuclear Information System (INIS)

    Prokhorov, L.V.

    1984-01-01

    Integration limits are studied for presenting the path integral curvilinear coordinates. For spherical (and topoloqically equivalent) coordinates it is shown that in formulas involving classical action in the exponent integration over all variables should be carried out within infinite limits. Another peculiarity is associated with appearance of the operator q which provides a complete definition of the wave functions out of the physical region. arguments are given upporting the validity of the cited statament in the general case

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

    Directory of Open Access Journals (Sweden)

    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

  6. Differentiation of osteophyte types in osteoarthritis - proposal of a histological classification.

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    Junker, Susann; Krumbholz, Grit; Frommer, Klaus W; Rehart, Stefan; Steinmeyer, Jürgen; Rickert, Markus; Schett, Georg; Müller-Ladner, Ulf; Neumann, Elena

    2016-01-01

    Osteoarthritis is not only characterized by cartilage degradation but also involves subchondral bone remodeling and osteophyte formation. Osteophytes are fibrocartilage-capped bony outgrowths originating from the periosteum. The pathophysiology of osteophyte formation is not completely understood. Yet, different research approaches are under way. Therefore, a histological osteophyte classification to achieve comparable results in osteophyte research was established for application to basic science research questions. The osteophytes were collected from knee joints of osteoarthritis patients (n=10, 94 osteophytes in total) after joint replacement surgery. Their size and origin in the respective joint were photo-documented. To develop an osteophyte classification, serial tissue sections were evaluated using histological (hematoxylin and eosin, Masson's trichrome, toluidine blue) and immunohistochemical staining (collagen type II). Based on the histological and immunohistochemical evaluation, osteophytes were categorized into four different types depending on the degree of ossification and the percentage of mesenchymal connective tissue. Size and localization of osteophytes were independent from the histological stages. This histological classification system of osteoarthritis osteophytes provides a helpful tool for analyzing and monitoring osteophyte development and for characterizing osteophyte types within a single human joint and may therefore contribute to achieve comparable results when analyzing histological findings in osteophytes. Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  7. Intralesional Osteophyte Regrowth Following Autologous Chondrocyte Implantation after Previous Treatment with Marrow Stimulation Technique.

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    Demange, Marco Kawamura; Minas, Tom; von Keudell, Arvind; Sodha, Sonal; Bryant, Tim; Gomoll, Andreas H

    2017-04-01

    Objective Bone marrow stimulation surgeries are frequent in the treatment of cartilage lesions. Autologous chondrocyte implantation (ACI) may be performed after failed microfracture surgery. Alterations to subchondral bone as intralesional osteophytes are commonly seen after previous microfracture and removed during ACI. There have been no reports on potential recurrence. Our purpose was to evaluate the incidence of intralesional osteophyte development in 2 cohorts: existing intralesional osteophytes and without intralesional osteophytes at the time of ACI. Study Design We identified 87 patients (157 lesions) with intralesional osteophytes among a cohort of 497 ACI patients. Osteophyte regrowth was analyzed on magnetic resonance imaging and categorized as small or large (less or more than 50% of the cartilage thickness). Twenty patients (24 defects) without intralesional osteophytes at the time of ACI acted as control. Results Osteophyte regrowth was observed in 39.5% of lesions (34.4% of small osteophytes and 5.1% of large osteophytes). In subgroup analyses, regrowth was observed in 45.8% of periosteal-covered defects and in 18.9% of collagen membrane-covered defects. Large osteophyte regrowth occurred in less than 5% in either group. Periosteal defects showed a significantly higher incidence for regrowth of small osteophytes. In the control group, intralesional osteophytes developed in 16.7% of the lesions. Conclusions Even though intralesional osteophytes may regrow after removal during ACI, most of them are small. Small osteophyte regrowth occurs almost twice in periosteum-covered ACI. Large osteophytes occur only in 5% of patients. Intralesional osteophyte formation is not significantly different in preexisting intralesional osteophytes and control groups.

  8. Hypertrophic anterior cervical osteophytes causing dysphagia and airway obstruction.

    Science.gov (United States)

    Lin, Harrison W; Quesnel, Alicia M; Holman, Allison S; Curry, William T; Rho, Michael B

    2009-10-01

    Hyperostosis of anterior cervical vertebral osteophytes can produce otolaryngological symptoms ranging from mild dysphagia, dysphonia, and foreign body sensation to severe food impaction and stridulous dyspnea. Airway compromise necessitating a tracheostomy is very rare. We discuss the case of an elderly man who presented with progressive dysphagia and a large hypopharyngeal mass as his initial manifestations of hypertrophic anterior cervical osteophytes. After a biopsy of the mass, the patient went into airway distress due to bilateral vocal fold fixation by the enlarging mass and consequently required a surgical airway. A combined team approach to the removal of the osteophytes successfully resolved his symptoms. The clinical, diagnostic, radiologic, and therapeutic principles involved in this case are presented and discussed. The recognition of hypertrophic osteophytes as a potential cause of common otolaryngological symptoms in the elderly population is paramount, as these symptoms can rapidly progress and lead to life-threatening airway obstruction. Medical and surgical interventions can be employed for the treatment of hypertrophic anterior cervical osteophytes, and they often result in favorable outcomes.

  9. Vertebral Osteophyte as Possible Etiology of Aortoenteric Fistula.

    Science.gov (United States)

    Janko, Matthew; Ciocca, Rocco G; Hacker, Robert I

    2018-05-01

    Aortoenteric fistula (AEF) and aortoenteric erosion (AEE) are deadly and difficult to diagnose. We present here a case report of a patient with a delayed diagnosis of AEF whose preoperative imaging revealed a large vertebral osteophyte which likely directed the aortic impulse into the duodenum. We believe this is the first report documenting an anatomical explanation for AEF/AEE and conclude that the presence of vertebral osteophytes should be considered a risk factor when assessing preoperative likelihood of AEF/AEE. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Morphometric and Histological Study of Osteophytes in Human Cadaveric Lumbar Vertebrae

    OpenAIRE

    Ashwini Aithal Padur; Naveen Kumar; Swamy Ravindra Shanthakumar; Arijit Bishnu

    2017-01-01

    Introduction: Osteophytes are bony outgrowth on the vertebral column. Its prevalence in the lumbar region and clinical importance mandates to conduct a detailed study of lumbar osteophytes in the cadaveric vertebral column. Aim: The present study was conducted to study the detailed features of lumbar osteophytes and document its prevalence, morphometric and histological structure. Materials and Methods: This was an observational study in which frequency of occurrence of lumbar osteophyt...

  11. The ultrastructure of the peri-articular osteophytes - an evaluation by ...

    African Journals Online (AJOL)

    Methods: Sections of periarticular osteophytes and osteophyte-normal articular cartilage composite tissues were obtained during total knee replacement for osteoarthritis (OA). These sections were routinely processed and examined using the scanning electron microscope with emphasis on the osteophytic cartilage mantle ...

  12. Atlas-based knee osteophyte assessment with ultrasonography and radiography

    DEFF Research Database (Denmark)

    Koski, J M; Kamel, Ayadi; Waris, P

    2016-01-01

    OBJECTIVES: To investigate intra- and inter-reader agreement of ultrasonography (US) and conventional radiography (CR) for the evaluation of osteophyte presence and size within the tibiofemoral joint. In addition, to correlate these findings with arthroscopic degeneration of the articular cartila...

  13. Can a giant cervical osteophyte cause dysphagia and airway obstruction? A case report.

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    Kapetanakis, Stylianos; Vasileiadis, Ioannis; Papanas, Nikolaos; Goulimari, Reggina; Maltezos, Eustratios

    2011-05-01

    Cervical spondylosis is a common disorder mainly affecting elderly people. It frequently presents with excessive bone formation (osteophytes). These may lead to pain and neurological deficits due to root compression. Dysphagia and airway obstruction due to a giant anterior osteophyte of the cervical spine are extremely rare. We present the case of an 81-year-old patient suffering from dysphagia and slight dyspnoea due to a giant cervical osteophyte. Osteophyte resection was performed and the patient was relieved from symptoms. This case highlights that a large cervical osteophyte may, albeit rarely, be the cause of simultaneously presenting dysphagia and dyspnoea, and should, therefore, be included in the diagnostic workup in such cases.

  14. Morphometric and Histological Study of Osteophytes in Human Cadaveric Lumbar Vertebrae

    Directory of Open Access Journals (Sweden)

    Ashwini Aithal Padur

    2017-10-01

    Full Text Available Introduction: Osteophytes are bony outgrowth on the vertebral column. Its prevalence in the lumbar region and clinical importance mandates to conduct a detailed study of lumbar osteophytes in the cadaveric vertebral column. Aim: The present study was conducted to study the detailed features of lumbar osteophytes and document its prevalence, morphometric and histological structure. Materials and Methods: This was an observational study in which frequency of occurrence of lumbar osteophytes was studied in 40 cadaveric vertebral columns over a period of four years. The lumbar part of the vertebral columns was dissected and examined meticulously. The occurrence of lumbar osteophytes with their vertebral levels and morphometric measurements were recorded. A small excision of the osteophyte was processed histologically to study its microscopic details using routine Haematoxylin & Eosin stain. Results: Lumbar osteophytes were present in 4 specimens (10%. They were mostly found on the right side of the vertebral bodies. Histopathological examination of the osteophytes revealed degenerative osteophytic cartilage and fibrillation overlying the trabecular bone enclosing fatty marrow spaces containing haematopoietic elements. Conclusion: Lumbar osteophytes were found in 10% of the specimens studied and it is assumed that these cadaveric reports deserve further attention given their potential clinical implications. Knowledge regarding occurrence and incidence of osteophytes is essential for management of common degenerative changes of the vertebral column.

  15. 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.

  16. 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.

  17. Widespread epigenomic, transcriptomic and proteomic differences between hip osteophytic and articular chondrocytes in osteoarthritis.

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    Steinberg, Julia; Brooks, Roger A; Southam, Lorraine; Bhatnagar, Sahir; Roumeliotis, Theodoros I; Hatzikotoulas, Konstantinos; Zengini, Eleni; Wilkinson, J Mark; Choudhary, Jyoti S; McCaskie, Andrew W; Zeggini, Eleftheria

    2018-05-08

    To identify molecular differences between chondrocytes from osteophytic and articular cartilage tissue from OA patients. We investigated genes and pathways by combining genome-wide DNA methylation, RNA sequencing and quantitative proteomics in isolated primary chondrocytes from the cartilaginous layer of osteophytes and matched areas of low- and high-grade articular cartilage across nine patients with OA undergoing hip replacement surgery. Chondrocytes from osteophytic cartilage showed widespread differences to low-grade articular cartilage chondrocytes. These differences were similar to, but more pronounced than, differences between chondrocytes from osteophytic and high-grade articular cartilage, and more pronounced than differences between high- and low-grade articular cartilage. We identified 56 genes with significant differences between osteophytic chondrocytes and low-grade articular cartilage chondrocytes on all three omics levels. Several of these genes have known roles in OA, including ALDH1A2 and cartilage oligomeric matrix protein, which have functional genetic variants associated with OA from genome-wide association studies. An integrative gene ontology enrichment analysis showed that differences between osteophytic and low-grade articular cartilage chondrocytes are associated with extracellular matrix organization, skeletal system development, platelet aggregation and regulation of ERK1 and ERK2 cascade. We present a first comprehensive view of the molecular landscape of chondrocytes from osteophytic cartilage as compared with articular cartilage chondrocytes from the same joints in OA. We found robust changes at genes relevant to chondrocyte function, providing insight into biological processes involved in osteophyte development and thus OA progression.

  18. Cartilaginous Metabolomic Study Reveals Potential Mechanisms of Osteophyte Formation in Osteoarthritis.

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    Xu, Zhongwei; Chen, Tingmei; Luo, Jiao; Ding, Shijia; Gao, Sichuan; Zhang, Jian

    2017-04-07

    Osteophyte is one of the inevitable consequences of progressive osteoarthritis with the main characteristics of cartilage degeneration and endochondral ossification. The pathogenesis of osteophyte formation is not fully understood to date. In this work, metabolomic approaches were employed to explore potential mechanisms of osteophyte formation by detecting metabolic variations between extracts of osteophyte cartilage tissues (n = 32) and uninvolved control cartilage tissues (n = 34), based on the platform of ultraperformance liquid chromatography tandem quadrupole time-of-flight mass spectrometry, as well as the use of multivariate statistic analysis and univariate statistic analysis. The osteophyte group was significantly separated from the control group by the orthogonal partial least-squares discriminant analysis models, indicating that metabolic state of osteophyte cartilage had been changed. In total, 28 metabolic variations further validated by mass spectrum (MS) match, tandom mass spectrum (MS/MS) match, and standards match mainly included amino acids, sulfonic acids, glycerophospholipids, and fatty acyls. These metabolites were related to some specific physiological or pathological processes (collagen dissolution, boundary layers destroyed, self-restoration triggered, etc.) which might be associated with the procedure of osteophyte formation. Pathway analysis showed phenylalanine metabolism (PI = 0.168, p = 0.004) was highly correlative to this degenerative process. Our findings provided a direction for targeted metabolomic study and an insight into further reveal the molecular mechanisms of ostophyte formation.

  19. Detection of osteophytes and subchondral cysts in the knee with use of tomosynthesis.

    Science.gov (United States)

    Hayashi, Daichi; Xu, Li; Roemer, Frank W; Hunter, David J; Li, Ling; Katur, Avinash M; Guermazi, Ali

    2012-04-01

    To evaluate the diagnostic performance of tomosynthesis in depicting osteophytes and subchondral cysts, with use of magnetic resonance (MR) imaging as the reference, and to test whether the lesions detected at radiography and tomosynthesis are associated with pain. The study was approved by local institutional review board, and all subjects gave written informed consent. Forty subjects (80 knees) older than 40 years were recruited irrespective of knee pain or radiographic osteoarthritis. Knees were imaged with radiography, tomosynthesis, and MR imaging. Presence of osteophytes and subchondral cysts in four locations of tibiofemoral joint (medial and lateral femur and tibia) was recorded. Knee pain was assessed by using the Western Ontario and McMaster University pain subscale. MR imaging depicted 171 osteophytes and 51 subchondral cysts. Tomosynthesis had a higher sensitivity for osteophyte detection in left and right lateral femur (0.96 vs 0.75, P = .025, and 1.00 vs 0.71, P = .008, respectively), right medial femur (0.94 vs 0.72, P = .046), and right lateral tibia (1.00 vs 0.83, P = .046). For subchondral cyst detection, the sensitivity of tomosynthesis was 0.14-1.00 and that of radiography was 0.00-0.56. Both modalities had similar specificity for both lesions. Subjects with tomosynthesis-depicted osteophytes (odds ratio, 4.2-6.4; P = .001-.011) and medially located subchondral cysts (odds ratio, 6.7-17.8; P = .004-.03) were more likely to feel pain than those without. However, radiography-depicted osteophytes were more strongly associated with pain than were tomosynthesis-depicted osteophytes. Tomosynthesis depicted more osteophytes and subchondral cysts than did radiography. Subjects with tomosynthesis-depicted osteophytes and subchondral cysts were more likely to feel pain than those without such lesions. © RSNA, 2012.

  20. Anterior cervical osteophytes causing dysphagia and dyspnea: an uncommon entity revisited.

    Science.gov (United States)

    Giger, Roland; Dulguerov, Pavel; Payer, Michael

    2006-10-01

    Large anterior cervical osteophytes can occur in degeneration of the cervical spine or in diffuse idiopathic skeletal hyperostosis (DISH). We present the case of an 83-year-old patient with progressive dysphagia and acute dyspnea, necessitating emergency tracheotomy. Voluminous anterior cervical osteophytes extending from C3 to C7 and narrowing the pharyngoesophageal segment by external compression and bilateral vocal fold immobility were diagnosed radiologically and by fiberoptic laryngoscopy. Surgical removal of all osteophytes led to the resolution of symptoms. Dyspnea with or without dysphagia caused by hypertrophic anterior cervical osteophytes is an uncommon entity. The exhaustive diagnostic workup proposed in the literature could be simplified by using fiberoptic laryngoscopy and dynamic videofluoroscopy. The causes, treatment, and outcome are discussed.

  1. Anterior Cervical Osteophytes Causing Dysphagia and Dyspnea: An Uncommon Entity Revisited

    OpenAIRE

    Giger, Roland; Dulguerov, Pavel; Payer, Michael

    2007-01-01

    Large anterior cervical osteophytes can occur in degeneration of the cervical spine or in diffuse idiopathic skeletal hyperostosis (DISH). We present the case of an 83-year-old patient with progressive dysphagia and acute dyspnea, necessitating emergency tracheotomy. Voluminous anterior cervical osteophytes extending from C3 to C7 and narrowing the pharyngoesophageal segment by external compression and bilateral vocal fold immobility were diagnosed radiologically and by fiberoptic laryngoscop...

  2. Osteoblasts derived from osteophytes produce interleukin-6, interleukin-8, and matrix metalloproteinase-13 in osteoarthritis.

    Science.gov (United States)

    Sakao, Kei; Takahashi, Kenji A; Arai, Yuji; Saito, Masazumi; Honjo, Kuniaki; Hiraoka, Nobuyuki; Asada, Hidetsugu; Shin-Ya, Masaharu; Imanishi, Jiro; Mazda, Osam; Kubo, Toshikazu

    2009-01-01

    To clarify the significance of the osteophytes that appear during the progression of osteoarthritis (OA), we investigated the expression of inflammatory cytokines and proteases in osteoblasts from osteophytes. We also examined the influence of mechanical stress loading on osteoblasts on the expression of inflammatory cytokines and proteases. Osteoblasts were isolated from osteophytes in 19 patients diagnosed with knee OA and from subchondral bone in 4 patients diagnosed with femoral neck fracture. Messenger RNA expression and protein production of inflammatory cytokines and proteases were analyzed using real-time RT-PCR and ELISA, respectively. To examine the effects of mechanical loading, continuous hydrostatic pressure was applied to the osteoblasts. We determined the mRNA expression and protein production of IL-6, IL-8, and MMP-13, which are involved in the progression of OA, were increased in the osteophytes. Additionally, when OA pathological conditions were simulated by applying a nonphysiological mechanical stress load, the gene expression of IL-6 and IL-8 increased. Our results suggested that nonphysiological mechanical stress may induce the expression of biological factors in the osteophytes and is involved in OA progression. By controlling the expression of these genes in the osteophytes, the progression of cartilage degeneration in OA may be reduced, suggesting a new treatment strategy for OA.

  3. Study progresses on continuous curvilinear capsulorhexis

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    Bo Gao

    2015-10-01

    Full Text Available As the progress of modern techniques for cataract extraction surgery and various needs of intraocular lens(IOLimplantation, continuous curvilinear capsulorhexis(CCCis still in absolute dominance among different ways of incision of anterior capsular lens in clinical practices, due to its advantages such as smoothness of capsulor opening, strong anti-tearing ability, integrity of supporting capsular bag, and strength at maintaining IOL stability. This article describes in general the historical development of CCC and complementary methods adapted to raise success rate when it is used in special cases of cataract extraction surgery. Meanwhile, the article also discusses briefly and envisions the prospects of femotsecond laser applied in CCC technique for cataract extraction.

  4. Novel device for creating continuous curvilinear capsulorhexis.

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    Soylak, Mustafa

    2016-01-01

    The purpose of this paper is to develop a novel capsulorhexis system. Mechatronics Laboratory, University of Erciyes and Kayseri Maya Eye Hospital. A 3D model was created and simulations were conducted to develop a new device which was designed, fabricated and tested for continuous curvilinear capsulorhexis (CCC). The name of this system is the electro-mechanical capsulorhexis system (EMCS). The 3D model was created by using a commercial design software and a 3D printer was used to fabricate the EMCS Finite element analysis and geometrical relation tests of the EMCS for different sized lenses were performed. The results show that the EMCS is a perfect solution for capsulorhexis surgeries, without mechanical or geometrical problems. The EMCS can open the anterior lens capsule more easily and effectively than manual CCC applications and needs less experience.

  5. 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 .

  6. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys.

    Science.gov (United States)

    Olson, Erik J; Lindgren, Bruce R; Carlson, Cathy S

    2008-05-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight-matched treatment groups for a 36-month treatment period. Group 1 (OVX control) received no treatment, Group 2 (SPE) received soy phytoestrogens, and Group 3 (ERT) received conjugated equine estrogens in the diet; all monkeys were labeled with calcein before necropsy. A midcoronal, plastic-embedded section of the right proximal tibia from 20 randomly selected animals per treatment group was examined histologically. Forty-nine of the sections (OVX control, n=16; SPE, n=16; ERT, n=17) contained lateral abaxial osteophytes, and static and dynamic histomorphometry measurements were taken from osteophyte bone, SCB from the lateral tibial plateau, and EMC bone. Data were analyzed using the ANOVA and Kruskal-Wallis test, correlation and regression methods, and the Friedman and Wilcoxon signed rank test. There was no significant effect of long-term ERT on osteophyte area or on any static or dynamic histomorphometry parameters. The bone volume, trabecular number, and trabecular thickness in osteophyte bone were considerably higher than in EMC bone; whereas, trabecular separation was considerably lower in osteophyte bone. In all three treatment groups, BS/BV was significantly lower in osteophyte bone vs. EMC bone and significantly higher in osteophyte bone vs. lateral SCB. We conclude that osteophyte area and static and dynamic histomorphometry parameters within periarticular tibial osteophytes in ovariectomized cynomolgus monkeys are not significantly influenced by long-term ERT, but

  7. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys

    Science.gov (United States)

    Olson, Erik J.; Lindgren, Bruce R.; Carlson, Cathy S.

    2008-01-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight-matched treatment groups for a 36-month treatment period. Group 1 (OVX control) received no treatment, Group 2 (SPE) received soy phytoestrogens, and Group 3 (ERT) received conjugated equine estrogens in the diet; all monkeys were labeled with calcein before necropsy. A midcoronal, plastic-embedded section of the right proximal tibia from 20 randomly selected animals per treatment group was examined histologically. Forty-nine of the sections (OVX control, n=16; SPE, n=16; ERT, n=17) contained lateral abaxial osteophytes, and static and dynamic histomorphometry measurements were taken from osteophyte bone, SCB from the lateral tibial plateau, and EMC bone. Data were analyzed using the ANOVA and Kruskal-Wallis test, correlation and regression methods, and the Friedman and Wilcoxon signed rank test. There was no significant effect of long-term ERT on osteophyte area or on any static or dynamic histomorphometry parameters. The bone volume, trabecular number, and trabecular thickness in osteophyte bone were considerably higher than in EMC bone; whereas, trabecular separation was considerably lower in osteophyte bone. In all three treatment groups, BS/BV was significantly lower in osteophyte bone vs. EMC bone and significantly higher in osteophyte bone vs. lateral SCB. We conclude that osteophyte area and static and dynamic histomorphometry parameters within periarticular tibial osteophytes in ovariectomized cynomolgus monkeys are not significantly influenced by long-term ERT, but

  8. Effect of anterior cervical osteophyte in poststroke dysphagia: a case-control study.

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    Kim, Youngkook; Park, Geun-Young; Seo, Yu Jung; Im, Sun

    2015-07-01

    To investigate whether the concomitant presence of anterior cervical osteophytes can influence the severity and outcome of patients with poststroke dysphagia. Retrospective case-control study. Hospital. A total of 40 participants were identified (N=40). Patients with poststroke dysphagia with anterior cervical osteophytes (n=20) were identified and matched by age, sex, location, and laterality of the stroke lesion to a poststroke dysphagia control group with no anterior cervical osteophytes (n=20). Not applicable. Videofluoroscopic swallowing study, Functional Oral Intake Scale (FOIS), and Penetration-Aspiration Scale results assessed within the first month of stroke were analyzed. The FOIS at 6 months was recorded, and severity of dysphagia was compared between the 2 groups. The case group had larger degrees of postswallow residues in the valleculae and pyriform sinuses (P=.020 and Pdysphagia (OR=15.375; 95% CI, 3.195-infinity). The presence of anterior cervical osteophytes, which may cause mechanical obstruction and interfere with residue clearance at the valleculae and pyriform sinuses and result in more postswallow aspiration, may influence initial severity and outcome of poststroke dysphagia. The presence of anterior cervical osteophytes may be considered an important clinical condition that may affect poststroke dysphagia rehabilitation. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  9. Use of Piezosurgery for removal of retrovertebral body osteophytes in anterior cervical discectomy.

    Science.gov (United States)

    Grauvogel, Juergen; Scheiwe, Christian; Kaminsky, Jan

    2014-04-01

    The relatively new technique of Piezosurgery is based on microvibrations, generated by the piezoelectrical effect, which results in selective bone cutting with preservation of adjacent soft tissue. To study the applicability of Piezosurgery in anterior cervical discectomy with fusion (ACDF) surgery. Prospective clinical study at the neurosurgical department of the University of Freiburg, Germany. Nine patients with cervical disc herniation and retrovertebral osteophytes who underwent ACDF surgery. Piezosurgery was evaluated with respect to practicability, safety, preciseness of bone cutting, and preservation of adjacent neurovascular tissue. Pre- and postoperative clinical and radiological data were assessed. Piezosurgery was supportively used in ACDF in nine patients with either radiculopathy or myelopathy from disc herniation or ventral osteophytes. After discectomy, osteophytes were removed with Piezosurgery to decompress the spinal canal and the foramina. Angled inserts were used, allowing for cutting even retrovertebral osteophytes. In all nine cases, Piezosurgery cut bone selectively with no damage to nerve roots, dura, or posterior longitudinal ligament. None of the patients experienced any new neurological deficit after the operation. The handling of the instrument was safe and the cut precise. Osteophytic spurs, even retrovertebral ones that generally only can be approached via corpectomies, could be safely removed because of the angled inserts through the disc space. Currently, a slightly prolonged operation time was observed for Piezosurgery. Furthermore, the design of the handpiece could be further improved to facilitate the intraoperative handling in ACDF. Piezosurgery proved to be a useful and safe technique for selective bone cutting and removal of osteophytes with preservation of neuronal and soft tissue in ACDF. In particular, the angled inserts were effective in cutting bone spurs behind the adjacent vertebra which cannot be reached with

  10. Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint

    Energy Technology Data Exchange (ETDEWEB)

    Kocasarac, Husniye Demirturk [Dept. of Comprehensive Dentistry, The University of Texas Health Science Center, San Antonio (United States); Celenk, Peruze [Dept. of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayis University, Samsun (Turkmenistan)

    2017-06-15

    Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

  11. Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint

    International Nuclear Information System (INIS)

    Kocasarac, Husniye Demirturk; Celenk, Peruze

    2017-01-01

    Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ. Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods. The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes. The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images

  12. Item response theory scoring and the detection of curvilinear relationships.

    Science.gov (United States)

    Carter, Nathan T; Dalal, Dev K; Guan, Li; LoPilato, Alexander C; Withrow, Scott A

    2017-03-01

    Psychologists are increasingly positing theories of behavior that suggest psychological constructs are curvilinearly related to outcomes. However, results from empirical tests for such curvilinear relations have been mixed. We propose that correctly identifying the response process underlying responses to measures is important for the accuracy of these tests. Indeed, past research has indicated that item responses to many self-report measures follow an ideal point response process-wherein respondents agree only to items that reflect their own standing on the measured variable-as opposed to a dominance process, wherein stronger agreement, regardless of item content, is always indicative of higher standing on the construct. We test whether item response theory (IRT) scoring appropriate for the underlying response process to self-report measures results in more accurate tests for curvilinearity. In 2 simulation studies, we show that, regardless of the underlying response process used to generate the data, using the traditional sum-score generally results in high Type 1 error rates or low power for detecting curvilinearity, depending on the distribution of item locations. With few exceptions, appropriate power and Type 1 error rates are achieved when dominance-based and ideal point-based IRT scoring are correctly used to score dominance and ideal point response data, respectively. We conclude that (a) researchers should be theory-guided when hypothesizing and testing for curvilinear relations; (b) correctly identifying whether responses follow an ideal point versus dominance process, particularly when items are not extreme is critical; and (c) IRT model-based scoring is crucial for accurate tests of curvilinearity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. Reliability of semiquantitative assessment of osteophytes and subchondral cysts on tomosynthesis images by radiologists with different levels of expertise.

    Science.gov (United States)

    Hayashi, Daichi; Xu, Li; Gusenburg, Jeffrey; Roemer, Frank W; Hunter, David J; Li, Ling; Guermazi, Ali

    2014-01-01

    We aimed to assess reliability of the evaluation of osteophytes and subchondral cysts on tomosynthesis images when read by radiologists with different levels of expertise. Forty subjects aged >40 years had both knees evaluated using tomosynthesis. Images were read by an "experienced" reader (musculoskeletal radiologist with prior experience) and an "inexperienced" reader (radiology resident with no prior experience). Readers graded osteophytes from 0 to 3 and noted the presence/absence of subchondral cysts in four locations of the tibiofemoral joint. Twenty knees were randomly selected and re-read. Inter- and intrareader reliabilities were calculated using overall exact percent agreement and weighted κ statistics. Diagnostic performance of the two readers was compared against magnetic resonance imaging readings by an expert reader (professor of musculoskeletal radiology). The experienced reader showed substantial intrareader reliability for graded reading of osteophytes (90%, κ=0.93), osteophyte detection (95%, κ=0.86) and cyst detection (95%, κ=0.83). The inexperienced reader showed perfect intrareader reliability for cyst detection (100%, κ=1.00) but intrareader reliability for graded reading (75%, κ=0.79) and detection (80%, κ=0.61) of osteophytes was lower than the experienced reader. Inter-reader reliability was 61% (κ=0.72) for graded osteophyte reading, 91% (κ=0.82) for osteophyte detection, and 88% (κ=0.66) for cyst detection. Diagnostic performance of the experienced reader was higher than the inexperienced reader regarding osteophyte detection (sensitivity range 0.74-0.95 vs. 0.54-0.75 for all locations) but diagnostic performance was similar for subchondral cysts. Tomosynthesis offers excellent intrareader reliability regardless of the reader experience, but experience is important for detection of osteophytes.

  14. Strontium ranelate causes osteophytes overgrowth in a model of early phase osteoarthritis.

    Science.gov (United States)

    Chu, Jian-Guo; Dai, Mu-Wei; Wang, Yu; Tian, Fa-Ming; Song, Hui-Ping; Xiao, Ya-Ping; Shao, Li-Tao; Zhang, Ying-Ze; Zhang, Liu

    2017-02-10

    Osteoarthritis (OA) involves cartilage changes as well as modifications of subchondral bone and synovial tissues. Strontium ranelate (SR), an anti-osteoporosis compound, which is currently in phase III clinical trial for treatment of OA. Evidences suggest that SR preferably deposited in osteophyte, other than in subchondral bone in early phase of OA. This phenomenon raises concern about its utility for OA treatment as a disease-modifying drug. To evaluate the effect of SR on cartilage, subchondral bone mass and subchondral trabecular bone structure in medial meniscectomized (MNX) guinea pigs. Thirty-six 3-month-old male Dunkin Hartley albino guinea pigs received either sham or medial meniscectomy operations. One week after the procedure, meniscectomized animals began 12 weeks of SR (625 mg/kg, daily) treatment by oral gavage for MNX + SR group, or normal saline for MNX + V group. All animals were euthanized 12 weeks later, cartilage degeneration and subchondral bone micro-architecture was analyzed. Both OARSI scores (P = 0.523 for marcoscopic scores, P = 0.297 for histological scores) and Cartilage thickness (P = 0.335) in MNX + SR group were comparable to MNX + V group. However, osteophyte sizes were larger in MNX + SR group (P = 0.014), and collapsed osteophytes in MNX + SR group (7 by 12) were significantly more than in MNX + V group (1 by 12) (P = 0.027), while immunohistochemistry indicates catabolic changes in osteophyte/plateau junction. Micro-CT analysis showed bone mineral density (BMD) (P = 0.001), bone volume fraction (BV/TV) (P = 0.008), trabecular spacing (Tb.Sp) (P = 0.020), trabecular thickness (Tb.Th) (P = 0.012) and structure model index (SMI) (P = 0.005) levels to be significantly higher in the MNX + SR group than in the MNX + V group. SR (625 mg/kg/day) did not protect cartilage from degeneration in MNX guinea pigs but subchondral bone was significantly enhanced. In early

  15. 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

  16. A rare cause of dysphagia: compression of the esophagus by an anterior cervical osteophyte due to ankylosing spondylitis.

    Science.gov (United States)

    Albayrak, Ilknur; Bağcacı, Sinan; Sallı, Ali; Kucuksen, Sami; Uğurlu, Hatice

    2013-09-01

    Ankylosing spondylitis (AS) is a chronic inflammatory rheumatological disease affecting the axial skeleton with various extra-articular complications. Dysphagia due to a giant anterior osteophyte of the cervical spine in AS is extremely rare. We present a 48-year-old male with AS suffering from progressive dysphagia to soft foods and liquids. Esophagography showed an anterior osteophyte at C5-C6 resulting in esophageal compression. The patient refused surgical resection of the osteophyte and received conservative therapy. However, after 6 months there was no improvement in dysphagia. This case illustrates that a large cervical osteophyte may be the cause of dysphagia in patients with AS and should be included in the diagnostic workup in early stages of the disease.

  17. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys

    OpenAIRE

    Olson, Erik J.; Lindgren, Bruce R.; Carlson, Cathy S.

    2007-01-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight...

  18. Strontium ranelate causes osteophytes overgrowth in a model of early phase osteoarthritis

    OpenAIRE

    Chu, Jian-Guo; Dai, Mu-Wei; Wang, Yu; Tian, Fa-Ming; Song, Hui-Ping; Xiao, Ya-Ping; Shao, Li-Tao; Zhang, Ying-Ze; Zhang, Liu

    2017-01-01

    Background Osteoarthritis (OA) involves cartilage changes as well as modifications of subchondral bone and synovial tissues. Strontium ranelate (SR), an anti-osteoporosis compound, which is currently in phase III clinical trial for treatment of OA. Evidences suggest that SR preferably deposited in osteophyte, other than in subchondral bone in early phase of OA. This phenomenon raises concern about its utility for OA treatment as a disease-modifying drug. To evaluate the effect of SR on cartil...

  19. Imaging and histological features of central subchondral osteophytes in racehorses with metacarpophalangeal joint osteoarthritis.

    Science.gov (United States)

    Olive, J; D'Anjou, M A; Girard, C; Laverty, S; Theoret, C L

    2009-12-01

    Marginal osteophytes represent a well known component of osteoarthritis in man and animals. Conversely, central subchondral osteophytes (COs), which are commonly present in human knees with osteoarthritis, have not been reported in horses. To describe and compare computed radiography (CR), single-slice computed tomography (CT), 1.5 Tesla magnetic resonance imaging (MRI), and histological features of COs in equine metacarpophalangeal joints with macroscopic evidence of naturally-occurring osteoarthritis. MRI sequences (sagittal spoiled gradient recalled echo [SPGR] with fat saturation, sagittal T2-weighted fast spin echo with fat saturation [T2-FS], dorsal and transverse T1-weighted gradient-recalled echo [GRE], and sagittal T2*-weighted gradient echo with fast imaging employing steady state acquisition [FIESTA]), as well as transverse and reformatted sagittal CTI and 4 computed radiographic (CR) views of 20 paired metacarpophalangeal joints were acquired ex vivo. Following macroscopic evaluation, samples were harvested in predetermined sites of the metacarpal condyle for subsequent histology. The prevalence and detection level of COs was determined for each imaging modality. Abnormalities consistent with COs were clearly depicted on MRI, using the SPGR sequence, in 7/20 (35%) joints. They were identified as a focal hypointense protuberance from the subchondral plate into the cartilage, at the palmarodistal aspect (n=7) and/or at the very dorsal aspect (n=2) of the metacarpal condyle. COs were visible but less obvious in 5 of the 7 joints using FIESTA and reformatted sagittal CT, and were not identifiable on T2-FS, T1-GRE or CR. Microscopically, they consisted of dense bone protruding into the calcified cartilage and disrupting the tidemarks, and they were consistently associated with overlying cartilage defects. Subchondral osteophytes are a feature of osteoarthritis of equine metacarpophalangeal joints and they may be diagnosed using 1.5 Tesla MRI and CT. Central

  20. Osteophyte detection for hand osteoarthritis identification in x-ray images using CNNs.

    Science.gov (United States)

    Banerjee, Sreeparna; Bhunia, Satyajit; Schaefer, Gerald

    2011-01-01

    In this paper we describe a class of analog algorithms based on the concept of cellular neural networks (CNNs) for detecting osteoarthritis (OA) from x-ray images. The indicator of OA that we examine is the presence of bony spurs or osteophytes in the vicinity of the weight bearing joints of the fingers. Results on a series of hand x-ray images are shown to be promising.

  1. Cervical spine degenerative changes (narrowed intervertebral disc spaces and osteophytes) in coal miners

    International Nuclear Information System (INIS)

    Zejda, J. E.; Stasiow, B.

    2003-01-01

    A series of 685 x-rays films of the cervical spine obtained in coal miners was analyzed to explore the occurrence of narrowed disc spaces and osteophytes in this occupational group, and to examine the association of x-rays changes with age, duration of employment, and duration of occupational exposure to hand-arm vibration. All data were extracted from individual medical files of coal miners examined for suspected hand-arm vibration-related disorders in 1989-1999 at the Occupational Medicine Center in Katowice. The narrowed intervertebral disc spaces were found in 188 coal miners (26.9%) and osteophytes in 332 coal miners (47.5%). The occurrence of degenerative changes in coal miners was similar to that observed in a small group of 68 blue-collar workers (no exposure to hand-arm vibration) employed in the coal industry. Univariate comparisons showed that intervertebral disc spaces and osteophytes were more frequent among older subjects and among subjects with longer duration of employment. The results of logistic regression analysis confirmed statistically significant effect of age, but not of other factors included in the model. When both x-ray changes were grouped together (a combined dependent variable) age remained the only statistically significant explanatory variable. The findings do not support the view that the examined degenerative changes in cervical spine are more prevalent in coal miners and depend on duration of physical work or local exposure to hand-arm vibration in this occupational group. (author)

  2. Linear and/or curvilinear rail mount system

    Science.gov (United States)

    Thomas, Jackie D. (Inventor); Harris, Lawanna L. (Inventor)

    2012-01-01

    One or more linear and/or curvilinear mounting rails are coupled to a structure. Each mounting rail defines a channel and at least one cartridge assembly is engaged in the channel. Each cartridge assembly includes a housing that slides within the channel. The housing defines a curvilinearly-shaped recess longitudinally aligned with the channel when the housing is in engagement therewith. The cartridge assembly also includes a cleat fitted in the recess for sliding engagement therealong. The cleat can be coupled to a fastener that passes through the mounting rail and the housing when the housing is so-engaged in the channel. The cleat is positioned in the recess by a position of the fastener.

  3. 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.

  4. Curvilinear ridges and related features in southwest Cydonia Mensae, Mars

    Science.gov (United States)

    Parker, Timothy J.; Schneeberger, Dale M.; Pieri, David C.; Saunders, R. Stephen

    1987-01-01

    Examined is a region on Mars in southwest Cydonia Mensae (32 deg lat., 17 deg long.) just northwest of the lowland/upland boundary escarpment. The dominant morphological features in this region are the clusters of large massifs and plateau outliers (PI), knobby material (K), and smooth lowland plains (Ps). Surrounding the clusters and linking many isolated knobs is a system of curvilinear ridges and arcuate terrain boundaries which tend to separate the massifs and knobs from the smooth plains. Curvilinear ridges are arcuate to nearly linear and smoother in plan than wrinkle ridges and show no apparent correlation with regional structural grain. They are typically 5 to 10 km long but can range from as little as 2 or 3 km to greater than 50 km long. The widths vary from about 100 m to as much as 2 km. Curvilinear ridges are most numerous within 100 km of the lowland/upland boundary escarpment and are associated with massifs and knobby terrain. Arcuate terrain boundaries appear between units of different apparent albedo or arcuate breaks in slope.

  5. Pattern of osteophytes and enthesophytes in the proximal ulna: an anatomic, paleopathologic, and radiologic study

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A [Department of Radiology, I.R.C.C.S. Maggiore Policlinico Hospital, Milan (Italy); Souto, S C.L. [Instituto de Radiologia, J.C. Rahal, Pelotas-RS (Brazil); Catalano, O A [Servizio di Radiologia, AO G Rummo, Benevento (Italy); Doria, A S [Department of Diagnostic Imaging, Research Institute, Hospital for Sick Children, Toronto, ON (Canada); Department of Medical Imaging, University of Toronto, ON (Canada); Trigo, P B.S. [Department of Radilology, Tenon Hospital, Paris (France); Resnick, D

    2006-11-15

    To develop a schematic segmentation of the proximal ulna in order to detect, assess the frequency, and characterize the bony outgrowths arising from the trochlea and from the radial notch of the ulna, to enable differentiation of osteophytes from enthesophytes. Eighty well-preserved ulna specimens from the collection of the San Diego Museum of Man were analyzed by two musculoskeletal radiologists. The trochlea and the radial notch of the ulna simulate the shape of a clock quadrant. The proximal ulna was divided into 24 anatomic areas. The relationships of the joint capsule and insertions of tendons and ligaments onto these area were assessed by the two readers, and the resulting appearances of bony outgrowths were compared at visual inspection and on Radiographs. The interobserver visual comparison was good in 17 areas out of 24, but poor correlation was found in 7 areas. In one case, difficulties in differentiating osteophytes originating from the brachialis muscle/ tendon (area 9) from an enthesophyte originating from the capsule insertion on the coronoid process (areas 2 or 3) occurredand between two different enthesophytes in a further case. Five cases had difficulties in defining differences in the grading system of the outgrowths. The percentage of outgrowths observed in each of the areas was globally high, especially in areas 9 and 10. On radiographs it was possible to observe irregularities in ten areas; in eight at a threshold of height of 2 mm (areas 1-4, 9, 10, 11, 14) and in two at a threshold of height of 3 mm (areas 5, 6). The two readers had the same difficulties in differentiating enthesophytes from osteophytes at radiographic and visual examination.

  6. Effects of a phosphocitrate analogue on osteophyte, subchondral bone advance, and bone marrow lesions in Hartley guinea pigs.

    Science.gov (United States)

    Sun, Y; Kiraly, A J; Sun, A R; Cox, M; Mauerhan, D R; Hanley, E N

    2018-02-01

    The objectives of this study were: 1) to examine osteophyte formation, subchondral bone advance, and bone marrow lesions (BMLs) in osteoarthritis (OA)-prone Hartley guinea pigs; and 2) to assess the disease-modifying activity of an orally administered phosphocitrate 'analogue', Carolinas Molecule-01 (CM-01). Young Hartley guinea pigs were divided into two groups. The first group (n = 12) had drinking water and the second group (n = 9) had drinking water containing CM-01. Three guinea pigs in each group were euthanized at age six, 12, and 18 months, respectively. Three guinea pigs in the first group were euthanized aged three months as baseline control. Radiological, histological, and immunochemical examinations were performed to assess cartilage degeneration, osteophyte formation, subchondral bone advance, BMLs, and the levels of matrix metalloproteinse-13 (MMP13) protein expression in the knee joints of hind limbs. In addition to cartilage degeneration, osteophytes, subchondral bone advance, and BMLs increased with age. Subchondral bone advance was observed as early as six months, whereas BMLs and osteophytes were both observed mainly at 12 and 18 months. Fibrotic BMLs were found mostly underneath the degenerated cartilage on the medial side. In contrast, necrotic BMLs were found almost exclusively in the interspinous region. Orally administered CM-01 decreased all of these pathological changes and reduced the levels of MMP13 expression. Subchondral bone may play a role in cartilage degeneration. Subchondral bone changes are early events; formation of osteophytes and BMLs are later events in the OA disease process. Carolinas Molecule-01 is a promising small molecule candidate to be tested as an oral disease-modifying drug for human OA therapy. Cite this article : Y. Sun, A. J. Kiraly, A. R. Sun, M. Cox, D. R. Mauerhan, E. N. Hanley Jr. Effects of a phosphocitrate analogue on osteophyte, subchondral bone advance, and bone marrow lesions in Hartley guinea

  7. 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. © 2014 International Union of Psychological Science.

  8. GAIA: A 2-D Curvilinear moving grid hydrodynamic code

    International Nuclear Information System (INIS)

    Jourdren, H.

    1987-02-01

    The GAIA computer code is developed for time dependent, compressible, multimaterial fluid flow problems, to overcome some drawbacks of traditional 2-D Lagrangian codes. The initial goals of robustness, entropy accuracies, efficiency in presence of large interfacial slip, have already been achieved. The general GODUNOV approach is applied to an arbitrary time varying control-volume formulation. We review in this paper the Riemann solver, the GODUNOV cartesian and curvilinear moving grid schemes and an efficient grid generation algorithm. We finally outline a possible second order accuracy extension

  9. Extracranial internal carotid artery dissection caused by compression from a giant osteophyte due to atlantoaxial osteoarthritis: case report.

    Science.gov (United States)

    Ikedo, Taichi; Nakamura, Kazuhito; Sano, Noritaka; Nagata, Manabu; Okada, Yumiko; Kawakami, Taichiro; Murata, Takaho

    2017-10-01

    Deformed osseous structures have been reported as rare causes of extracranial internal carotid artery (ICA) dissection, including the styloid process and the hyoid bone. Here, the authors describe the first known case of symptomatic ICA dissection caused by a giant osteophyte due to atlantoaxial osteoarthritis. The left ICA was fixed at the skull base and at the ICA portion compressed by the osteophyte, and it was highly stretched and injured between the two portions during neck rotation. The patient was successfully treated with ligation of the affected ICA following balloon test occlusion. Atlantoaxial osteoarthritis should be considered in the differential diagnosis of ICA dissection in patients with a severely deformed cervical spine.

  10. Arthropathy in long-term cured acromegaly is characterised by osteophytes without joint space narrowing: a comparison with generalised osteoarthritis

    NARCIS (Netherlands)

    Wassenaar, M. J. E.; Biermasz, N. R.; Bijsterbosch, J.; Pereira, A. M.; Meulenbelt, I.; Smit, J. W. A.; Roelfsema, F.; Kroon, H. M.; Romijn, J. A.; Kloppenburg, M.

    2011-01-01

    To compare the distribution of osteophytes and joint space narrowing (JSN) between patients with acromegaly and primary generalised osteoarthritis to gain insight into the pathophysiological process of growth hormone (GH) and insulin-like growth factor type I (IGF-I)-mediated osteoarthritis. We

  11. Computed tomography of subchondral bone and osteophytes in hip osteoarthritis: the shape of things to come?

    Science.gov (United States)

    Turmezei, Tom D; Poole, Ken E S

    2011-01-01

    Bone is a fundamental component of the disordered joint homeostasis seen in osteoarthritis, a disease that has been primarily characterized by the breakdown of articular cartilage accompanied by local bone changes and a limited degree of joint inflammation. In this review we consider the role of computed tomography imaging and computational analysis in osteoarthritis research, focusing on subchondral bone and osteophytes in the hip. We relate what is already known in this area to what could be explored through this approach in the future in relation to both clinical research trials and the underlying cellular and molecular science of osteoarthritis. We also consider how this area of research could impact on our understanding of the genetics of osteoarthritis.

  12. Computed tomography of subchondral bone and osteophytes in hip osteoarthritis: the shape of things to come?

    Directory of Open Access Journals (Sweden)

    Tom D Turmezei

    2011-12-01

    Full Text Available Bone is a fundamental component of the disordered joint homeostasis seen in osteoarthritis, a disease that has been primarily characterised by the breakdown of articular cartilage accompanied by local bone changes and a limited degree of joint inflammation. In this review we consider the role of computed tomography imaging and computational analysis in osteoarthritis research, focusing on subchondral bone and osteophytes in the hip. We relate what is already known in this area to what could be explored through this approach in the future in relation to both clinical research trials and the underlying cellular and molecular science of osteoarthritis. We also consider how this area of research could impact on our understanding of the genetics of osteoarthritis.

  13. Exogenous fibroblast growth factor 9 attenuates cartilage degradation and aggravates osteophyte formation in post-traumatic osteoarthritis.

    Science.gov (United States)

    Zhou, S; Wang, Z; Tang, J; Li, W; Huang, J; Xu, W; Luo, F; Xu, M; Wang, J; Wen, X; Chen, L; Chen, H; Su, N; Shen, Y; Du, X; Xie, Y; Chen, L

    2016-12-01

    The aim of the present study is to investigate the effects of exogenous fibroblast growth factor (FGF)9 on the progression of post-traumatic osteoarthritis (OA). The expression of FGF9 in articular cartilage with OA is detected by immunohistochemistry (IHC). The effects of intra-articular exogenous FGF9 injection on post-traumatic OA induced by the destabilization of the medial meniscus (DMM) surgery are evaluated. Cartilage changes and osteophyte formation in knee joints are investigated by histological analysis. Changes in subchondral bone are evaluated by microcomputed tomography (micro-CT). The effect of exogenous FGF9 on an interleukin-1β (IL-1β)-induced ex vivo OA model of human articular cartilage tissues is also evaluated. FGF9 expression was down-regulated in articular chondrocytes of OA but ectopically induced at sites of osteophyte formation. Intra-articular injection of exogenous FGF9 attenuated articular cartilage degradation in mice after DMM surgery. Exogenous FGF9 suppressed collagen X and MMP13 expressions in OA cartilage, while promoted collagen II expression. Similar results were observed in IL-1β-induced ex vivo OA model. Intra-articular injection of FGF9 had no significant effect on the subchondral bone of knee joints after DMM surgery, but aggravated osteophyte formation. The expressions of SOX9 and collagen II, and cell proliferation were up-regulated at sites of initial osteophyte formation in mice with exogenous FGF9 treatment. Intra-articular injection of exogenous FGF9 delays articular cartilage degradation in post-traumatic OA, while aggravates osteophyte formation. Copyright © 2016. Published by Elsevier Ltd.

  14. 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.

  15. Association of medial meniscal extrusion with medial tibial osteophyte distance detected by T2 mapping MRI in patients with early-stage knee osteoarthritis.

    Science.gov (United States)

    Hada, Shinnosuke; Ishijima, Muneaki; Kaneko, Haruka; Kinoshita, Mayuko; Liu, Lizu; Sadatsuki, Ryo; Futami, Ippei; Yusup, Anwajan; Takamura, Tomohiro; Arita, Hitoshi; Shiozawa, Jun; Aoki, Takako; Takazawa, Yuji; Ikeda, Hiroshi; Aoki, Shigeki; Kurosawa, Hisashi; Okada, Yasunori; Kaneko, Kazuo

    2017-09-12

    Medial meniscal extrusion (MME) is associated with progression of medial knee osteoarthritis (OA), but no or little information is available for relationships between MME and osteophytes, which are found in cartilage and bone parts. Because of the limitation in detectability of the cartilage part of osteophytes by radiography or conventional magnetic resonance imaging (MRI), the rate of development and size of osteophytes appear to have been underestimated. Because T2 mapping MRI may enable us to evaluate the cartilage part of osteophytes, we aimed to examine the association between MME and OA-related changes, including osteophytes, by using conventional and T2 mapping MRI. Patients with early-stage knee OA (n = 50) were examined. MRI-detected OA-related changes, in addition to MME, were evaluated according to the Whole-Organ Magnetic Resonance Imaging Score. T2 values of the medial meniscus and osteophytes were measured on T2 mapping images. Osteophytes surgically removed from patients with end-stage knee OA were histologically analyzed and compared with findings derived by radiography and MRI. Medial side osteophytes were detected by T2 mapping MRI in 98% of patients with early-stage knee OA, although the detection rate was 48% by conventional MRI and 40% by radiography. Among the OA-related changes, medial tibial osteophyte distance was most closely associated with MME, as determined by multiple logistic regression analysis, in the patients with early-stage knee OA (β = 0.711, p T2 values of the medial meniscus were directly correlated with MME in patients with early-stage knee OA, who showed ≥ 3 mm of MME (r = 0.58, p = 0.003). The accuracy of osteophyte evaluation by T2 mapping MRI was confirmed by histological analysis of the osteophytes removed from patients with end-stage knee OA. Our study demonstrates that medial tibial osteophyte evaluated by T2 mapping MRI is frequently observed in the patients with early-stage knee OA, showing

  16. Effects of a phosphocitrate analogue on osteophyte, subchondral bone advance, and bone marrow lesions in Hartley guinea pigs

    Science.gov (United States)

    Kiraly, A. J.; Sun, A. R.; Cox, M.; Mauerhan, D. R.; Hanley, E. N.

    2018-01-01

    Objectives The objectives of this study were: 1) to examine osteophyte formation, subchondral bone advance, and bone marrow lesions (BMLs) in osteoarthritis (OA)-prone Hartley guinea pigs; and 2) to assess the disease-modifying activity of an orally administered phosphocitrate ‘analogue’, Carolinas Molecule-01 (CM-01). Methods Young Hartley guinea pigs were divided into two groups. The first group (n = 12) had drinking water and the second group (n = 9) had drinking water containing CM-01. Three guinea pigs in each group were euthanized at age six, 12, and 18 months, respectively. Three guinea pigs in the first group were euthanized aged three months as baseline control. Radiological, histological, and immunochemical examinations were performed to assess cartilage degeneration, osteophyte formation, subchondral bone advance, BMLs, and the levels of matrix metalloproteinse-13 (MMP13) protein expression in the knee joints of hind limbs. Results In addition to cartilage degeneration, osteophytes, subchondral bone advance, and BMLs increased with age. Subchondral bone advance was observed as early as six months, whereas BMLs and osteophytes were both observed mainly at 12 and 18 months. Fibrotic BMLs were found mostly underneath the degenerated cartilage on the medial side. In contrast, necrotic BMLs were found almost exclusively in the interspinous region. Orally administered CM-01 decreased all of these pathological changes and reduced the levels of MMP13 expression. Conclusion Subchondral bone may play a role in cartilage degeneration. Subchondral bone changes are early events; formation of osteophytes and BMLs are later events in the OA disease process. Carolinas Molecule-01 is a promising small molecule candidate to be tested as an oral disease-modifying drug for human OA therapy. Cite this article: Y. Sun, A. J. Kiraly, A. R. Sun, M. Cox, D. R. Mauerhan, E. N. Hanley Jr. Effects of a phosphocitrate analogue on osteophyte, subchondral bone advance, and

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

    International Nuclear Information System (INIS)

    Hayeri, Mohammad Reza; Shiehmorteza, Masoud; Trudell, Debra J.; Resnick, Donald; Hefflin, Tori

    2010-01-01

    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 intercondylar tibial spine

  18. An osteophyte in the tibial plateau is a risk factor for allograft extrusion after meniscus allograft transplantation.

    Science.gov (United States)

    Jeon, Byeongsam; Kim, Jong-Min; Kim, Jong-Min; Lee, Chang-Rack; Kim, Kyung-Ah; Bin, Seong-Il

    2015-05-01

    Osteophytes can be observed on the tibial plateau during meniscus allograft transplantation (MAT). However, no studies to date have evaluated the effect of these osteophytes on meniscus allograft extrusion. Osteophyte excision in the tibial plateau could reduce extrusion of the transplanted meniscus and improve short-term clinical outcomes with meniscus allograft transplantation. Cohort study; Level of evidence, 3. Between October 2004 and July 2012, a total of 323 patients underwent MAT at a single institution. Of these, 88 patients had a peripheral osteophyte in their tibial plateau, and they were enrolled in the study retrospectively. The mean age of the patients was 35.3 years (range, 15-56 years); there were 57 male and 31 female patients. Forty-four patients underwent osteophyte excision concomitantly with MAT and 44 patients underwent MAT only. The 2 groups showed no difference in terms of age, body mass index, time after meniscectomy, and preoperative knee scores. A medial meniscus allograft was transplanted in 13 cases (15%) and a lateral meniscus in 75 (85%). The absolute extrusion and relative percentage of extrusion were measured to evaluate allograft extrusion 12 months after MAT. The modified Lysholm scoring system and the Hospital for Special Surgery score at 2 years after MAT were used to evaluate clinical outcomes. The mean absolute extrusions at 1 year postoperatively in the excision and nonexcision groups were 3.5±1.5 and 5.5±1.6 mm, respectively. The mean relative percentages of extrusion were 34.1%±15.9% and 54.7%±20.7%, respectively. The rates of allograft extrusion (>3 mm) were 28 of 44 (63.6%) and 41 of 44 (93.2%) in the excision and nonexcision groups, respectively. The intergroup differences in absolute extrusion, relative percentage of extrusion, and rate of allograft extrusion were statistically significant (P<.001 for all 3 parameters). There were no significant differences in the clinical outcomes (modified Lysholm or Hospital of

  19. 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

  20. 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. PMID:25238547

  1. 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

  2. Ultrafast dynamic computed tomography myelography for the precise identification of high-flow cerebrospinal fluid leaks caused by spiculated spinal osteophytes.

    Science.gov (United States)

    Thielen, Kent R; Sillery, John C; Morris, Jonathan M; Hoxworth, Joseph M; Diehn, Felix E; Wald, John T; Rosebrock, Richard E; Yu, Lifeng; Luetmer, Patrick H

    2015-03-01

    Precise localization and understanding of the origin of spontaneous high-flow spinal CSF leaks is required prior to targeted treatment. This study demonstrates the utility of ultrafast dynamic CT myelography for the precise localization of high-flow CSF leaks caused by spiculated spinal osteophytes. This study reports a series of 14 patients with high-flow CSF leaks caused by spiculated spinal osteophytes who underwent ultrafast dynamic CT myelography between March 2009 and December 2010. There were 10 male and 4 female patients, with an average age of 49 years (range 37-74 years). The value of ultrafast dynamic CT myelography in depicting the CSF leak site was qualitatively assessed. In all 14 patients, ultrafast dynamic CT myelography was technically successful at precisely demonstrating the site of the CSF leak, the causative spiculated osteophyte piercing the dura, and the relationship of the implicated osteophyte to adjacent structures. Leak sites included 3 cervical, 11 thoracic, and 0 lumbar levels, with 86% of the leaks occurring from C-5 to T-7. Information obtained from the ultrafast dynamic CT myelogram was considered useful in all treated CSF leaks. Spinal osteophytes piercing the dura are a more frequent cause of high-flow CSF leaks than previously recognized. Ultrafast dynamic CT myelography adds value beyond standard dynamic myelography or digital subtraction myelography in the diagnosis and anatomical characterization of high-flow spinal CSF leaks caused by these osteophytes. This information allows for appropriate planning for percutaneous or surgical treatment.

  3. Transglutaminase-2 differently regulates cartilage destruction and osteophyte formation in a surgical model of osteoarthritis.

    Science.gov (United States)

    Orlandi, A; Oliva, F; Taurisano, G; Candi, E; Di Lascio, A; Melino, G; Spagnoli, L G; Tarantino, U

    2009-04-01

    Osteoarthritis is a progressive joint disease characterized by cartilage degradation and bone remodeling. Transglutaminases catalyze a calcium-dependent transamidation reaction that produces covalent cross-linking of available substrate glutamine residues and modifies the extracellular matrix. Increased transglutaminases-mediated activity is reported in osteoarthritis, but the relative contribution of transglutaminases-2 (TG2) is uncertain. We describe TG2 expression in human femoral osteoarthritis and in wild-type and homozygous TG2 knockout mice after surgically-induced knee joint instability. Increased TG2 levels were observed in human and wild-type murine osteoarthritic cartilage compared to the respective controls. Histomorphometrical but not X-ray investigation documented in osteoarthritic TG2 knockout mice reduced cartilage destruction and an increased osteophyte formation compared to wild-type mice. These differences were associated with increased TGFbeta-1 expression. In addition to confirming its important role in osteoarthritis development, our results demonstrated that TG2 expression differently influences cartilage destruction and bone remodeling, suggesting new targeted TG2-related therapeutic strategies.

  4. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model

    OpenAIRE

    Joh, Ju Youn; Kim, Sun; Park, Jun Li; Kim, Yeon Pyo

    2013-01-01

    Background The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. Methods We us...

  5. BRIEF COMMUNICATION: A note on the Coulomb collision operator in curvilinear coordinates

    Science.gov (United States)

    Goncharov, P. R.

    2010-10-01

    The dynamic friction force, diffusion tensor, flux density in velocity space and Coulomb collision term are expressed in curvilinear coordinates via Trubnikov potential functions corresponding to each species of a background plasma. For comparison, explicit formulae are given for the dynamic friction force, diffusion tensor and collisional flux density in velocity space in curvilinear coordinates via Rosenbluth potential functions summed over all species of the background plasma.

  6. Capsular phimosis with complete occlusion of the anterior capsular opening after intact continuous curvilinear capsulorrhexis

    International Nuclear Information System (INIS)

    Al-Kharashi, Soliman A.; Al-Obailan, Majed

    2009-01-01

    Shrinkage and whitening of the anterior capsule opening - capsular contraction syndrome - is a well-known complication after continuous curvilinear capsulorrhexis. A 72-year-old women underwent continuous curvilinear capsulorrhexis, phacoemulsification, and implantation of posterior chamber intraocular lens with polymethylmethacrylate haptics. Four months postoperatively, the patient reported deterioration in visual acuity that was resulted due to complete occlusion of anterior capsular opening by fibrotic tissue. The fibrous membrane was excised surgically in capsulorrhexis fashion. (author)

  7. SENR /NRPy + : Numerical relativity in singular curvilinear coordinate systems

    Science.gov (United States)

    Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

    2018-03-01

    We report on a new open-source, user-friendly numerical relativity code package called SENR /NRPy + . Our code extends previous implementations of the BSSN reference-metric formulation to a much broader class of curvilinear coordinate systems, making it ideally suited to modeling physical configurations with approximate or exact symmetries. In the context of modeling black hole dynamics, it is orders of magnitude more efficient than other widely used open-source numerical relativity codes. NRPy + provides a Python-based interface in which equations are written in natural tensorial form and output at arbitrary finite difference order as highly efficient C code, putting complex tensorial equations at the scientist's fingertips without the need for an expensive software license. SENR provides the algorithmic framework that combines the C codes generated by NRPy + into a functioning numerical relativity code. We validate against two other established, state-of-the-art codes, and achieve excellent agreement. For the first time—in the context of moving puncture black hole evolutions—we demonstrate nearly exponential convergence of constraint violation and gravitational waveform errors to zero as the order of spatial finite difference derivatives is increased, while fixing the numerical grids at moderate resolution in a singular coordinate system. Such behavior outside the horizons is remarkable, as numerical errors do not converge to zero near punctures, and all points along the polar axis are coordinate singularities. The formulation addresses such coordinate singularities via cell-centered grids and a simple change of basis that analytically regularizes tensor components with respect to the coordinates. Future plans include extending this formulation to allow dynamical coordinate grids and bispherical-like distribution of points to efficiently capture orbiting compact binary dynamics.

  8. Alpha C-telopeptide of type I collagen is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis.

    Science.gov (United States)

    Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

    2014-09-01

    To evaluate joint tissue remodeling using the urinary collagen biomarkers urinary α-C-telopeptide of type I collagen (α-CTX) and urinary C-telopeptide of type II collagen (CTX-II) and to determine the association of these biomarkers with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Participants (n = 149) with symptomatic and radiographic knee OA underwent fixed-flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, which were scored semiquantitatively for osteophyte and joint space narrowing (JSN) severity and uptake intensity, with scores summed across knees. Urinary concentrations of α-CTX and CTX-II were determined by enzyme-linked immunosorbent assay. Immunohistochemical analysis of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Urinary α-CTX concentrations correlated strongly with the intensity of bone scintigraphic uptake and with JSN progression (risk ratio 13.2) and osteophyte progression (risk ratio 3). Urinary CTX-II concentrations were strongly associated with intensity of bone scintigraphic uptake, with JSN and osteophyte severity, and with OA progression based on osteophyte score. Urinary α-CTX localized primarily to high bone turnover areas in subchondral bone. CTX-II localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Baseline urinary α-CTX, which was localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees, as signified by scintigraphy, and progression of both osteophytes and JSN. Urinary CTX-II correlated with JSN and osteophyte severity and progression of osteophytes. To our knowledge, this represents the first report of serologic markers reflecting subchondral bone turnover. These collagen markers may be useful for noninvasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA

  9. 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 (P<0.01), and males were significantly greater than females (P<0.05). The highest prevalence of osteophytes was on the anterior side of superior surface of body (30.4%), and the classification was traction. It can be proposed that the abdominal aorta could be damaged, especially a risk of rupture of abdominal aortic aneurysm.

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

    International Nuclear Information System (INIS)

    Gülçiçek, Çağlar; Damlı, Volkan

    2016-01-01

    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. (paper)

  11. Controlled release of celecoxib inhibits inflammation, bone cysts and osteophyte formation in a preclinical model of osteoarthritis.

    Science.gov (United States)

    Tellegen, A R; Rudnik-Jansen, I; Pouran, B; de Visser, H M; Weinans, H H; Thomas, R E; Kik, M J L; Grinwis, G C M; Thies, J C; Woike, N; Mihov, G; Emans, P J; Meij, B P; Creemers, L B; Tryfonidou, M A

    2018-11-01

    Major hallmarks of osteoarthritis (OA) are cartilage degeneration, inflammation and osteophyte formation. COX-2 inhibitors counteract inflammation-related pain, but their prolonged oral use entails the risk for side effects. Local and prolonged administration in biocompatible and degradable drug delivery biomaterials could offer an efficient and safe treatment for the long-term management of OA symptoms. Therefore, we evaluated the disease-modifying effects and the optimal dose of polyesteramide microspheres delivering the COX-2 inhibitor celecoxib in a rat OA model. Four weeks after OA induction by anterior cruciate ligament transection and partial medial meniscectomy, 8-week-old female rats (n = 6/group) were injected intra-articular with celecoxib-loaded microspheres at three dosages (0.03, 0.23 or 0.39 mg). Unloaded microspheres served as control. During the 16-week follow-up, static weight bearing and plasma celecoxib concentrations were monitored. Post-mortem, micro-computed tomography and knee joint histology determined progression of synovitis, osteophyte formation, subchondral bone changes, and cartilage integrity. Systemic celecoxib levels were below the detection limit 6 days upon delivery. Systemic and local adverse effects were absent. Local delivery of celecoxib reduced the formation of osteophytes, subchondral sclerosis, bone cysts and calcified loose bodies, and reduced synovial inflammation, while cartilage histology was unaffected. Even though the effects on pain could not be evualated directly in the current model, our results suggest the application of celecoxib-loaded microspheres holds promise as novel, safe and effective treatment for inflammation and pain in OA.

  12. Magnetic resonance imaging of osteophytic, chondral, and subchondral structures in a surgically-induced osteoarthritis rabbit model.

    Directory of Open Access Journals (Sweden)

    Lang Jia

    Full Text Available OBJECTIVE: This study aimed to assess changes in osteophytic, chondral, and subchondral structures in a surgically-induced osteoarthritis (OA rabbit model in order to correlate MRI findings with the macroscopic progress of OA and to define the timepoint for disease status in this OA model. METHODS: The OA model was constructed by surgery in thirty rabbits with ten normal rabbits serving as controls (baseline. High-resolution three-dimensional MRI using a 1.5-T coil was performed at baseline, two, four, and eight weeks post-surgery. MRIs of cartilage lesions, subchondral bone lesions, and osteophyte formations were independently assessed by two blinded radiologists. Ten rabbits were sacrificed at baseline, two, four, and eight weeks post-surgery, and macroscopic evaluation was independently performed by two blinded orthopedic surgeons. RESULTS: The signal intensities and morphologies of chondral and subchondral structures by MRI accurately reflected the degree of OA. Cartilage defects progressed from a grade of 0.05-0.15 to 1.15-1.30 to 1.90-1.97 to 3.00-3.35 at each successive time point, respectively (p<0.05. Subchondral bone lesions progressed from a grade of 0.00 to 0.78-0.90 to 1.27-1.58 to 1.95-2.23 at each successive time point, respectively (p = 0.000. Osteophytes progressed from a size (mm of 0.00 to 0.87-1.06 to 1.24-1.87 to 2.21-3.21 at each successive time point, respectively (p = 0.000. CONCLUSIONS: Serial observations revealed that MRI can accurately detect the progression of cartilage lesions and subchondral bone edema over an eight-week period but may not be accurate in detecting osteophyte sizes. Week four post-surgery was considered the timepoint between OA-negative and OA-positive status in this OA model. The combination of this OA model with MRI evaluation should provide a promising tool for the pre-clinical evaluation of new disease-modifying osteoarthritis drugs.

  13. Magnetic resonance imaging of osteophytic, chondral, and subchondral structures in a surgically-induced osteoarthritis rabbit model.

    Science.gov (United States)

    Jia, Lang; Chen, Jinyun; Wang, Yan; Liu, Yingjiang; Zhang, Yu; Chen, Wenzhi

    2014-01-01

    This study aimed to assess changes in osteophytic, chondral, and subchondral structures in a surgically-induced osteoarthritis (OA) rabbit model in order to correlate MRI findings with the macroscopic progress of OA and to define the timepoint for disease status in this OA model. The OA model was constructed by surgery in thirty rabbits with ten normal rabbits serving as controls (baseline). High-resolution three-dimensional MRI using a 1.5-T coil was performed at baseline, two, four, and eight weeks post-surgery. MRIs of cartilage lesions, subchondral bone lesions, and osteophyte formations were independently assessed by two blinded radiologists. Ten rabbits were sacrificed at baseline, two, four, and eight weeks post-surgery, and macroscopic evaluation was independently performed by two blinded orthopedic surgeons. The signal intensities and morphologies of chondral and subchondral structures by MRI accurately reflected the degree of OA. Cartilage defects progressed from a grade of 0.05-0.15 to 1.15-1.30 to 1.90-1.97 to 3.00-3.35 at each successive time point, respectively (pSubchondral bone lesions progressed from a grade of 0.00 to 0.78-0.90 to 1.27-1.58 to 1.95-2.23 at each successive time point, respectively (p = 0.000). Osteophytes progressed from a size (mm) of 0.00 to 0.87-1.06 to 1.24-1.87 to 2.21-3.21 at each successive time point, respectively (p = 0.000). Serial observations revealed that MRI can accurately detect the progression of cartilage lesions and subchondral bone edema over an eight-week period but may not be accurate in detecting osteophyte sizes. Week four post-surgery was considered the timepoint between OA-negative and OA-positive status in this OA model. The combination of this OA model with MRI evaluation should provide a promising tool for the pre-clinical evaluation of new disease-modifying osteoarthritis drugs.

  14. Job insecurity and organizational citizenship behavior: exploring curvilinear and moderated relationships.

    Science.gov (United States)

    Lam, Chak Fu; Liang, Jian; Ashford, Susan J; Lee, Cynthia

    2015-03-01

    This article examined a curvilinear relationship between job insecurity and organizational citizenship behavior (OCB). Drawing from social exchange theory and research on personal control, we developed and tested an explanation for employees' reactions to job insecurity based on their conceptualization of their social exchange relationship with the organization at different levels of job insecurity. Using data from 244 Chinese employees and 102 supervisory ratings of OCB, we found support for a U-shaped relationship between job insecurity and OCB. Moreover, 2 factors--psychological capital and subordinate-supervisor guanxi--moderated the curvilinear relationship, such that the curvilinear relationship is more pronounced among those with lower psychological capital or less positive subordinate-supervisor guanxi. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  15. Hidden osteophyte formation on plain X-ray is the predictive factor for development of knee osteoarthritis after 48 months--data from the Osteoarthritis Initiative.

    Science.gov (United States)

    Katsuragi, J; Sasho, T; Yamaguchi, S; Sato, Y; Watanabe, A; Akagi, R; Muramatsu, Y; Mukoyama, S; Akatsu, Y; Fukawa, T; Endo, J; Hoshi, H; Yamamoto, Y; Sasaki, T; Takahashi, K

    2015-03-01

    To examine whether the detection of osteophytes anywhere in the knee could serve as a pre-radiographic biomarker for osteoarthritis (OA) development. Baseline magnetic resonance imaging (MRIs) of 132 participants in the Osteoarthritis Initiative (OAI) were studied. Based on radiographs, 66 knees were assessed as osteoarthritis-free (no-osteoarthritis [NOA], or Kellgren/Lawrence [K/L] severity grade 0/1 both at baseline and 48 months), and another 66 knees were assessed as having radiographic OA changes (pre-radiographic osteoarthritis [PROA], or with K/L grade 0/1 at baseline and grade ≥ 2 at 48 months). Using baseline MRI data, we examined eight sites of osteophyte formation: the medial and lateral femoral condyle (MFC and LFC, respectively); medial and lateral tibial plateau (MTP and LTP, respectively); medial and lateral facets of the patellofemoral joint (PM and PL, respectively); tibial spine (TS); and femoral intercondylar notch (IC). Knee joint osteophyte size was assessed via the 8-point marginal osteophytes item of the whole-organ magnetic resonance imaging score (WORMS). The frequencies and distributions of osteophytes were compared between groups. Mild-size osteophytes (defined as score ≥ 2) were observed more frequently at the MFC (P = 0.00278), MTP (P = 0.0046), TS (P = 0.0146), PM (P formation at the IC, even those of K/L severity grade 0/1, are at risk for the development of radiographic OA by 48 months. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  16. 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.

  17. Asporin and transforming growth factor-beta gene expression in osteoblasts from subchondral bone and osteophytes in osteoarthritis.

    Science.gov (United States)

    Sakao, Kei; Takahashi, Kenji A; Arai, Yuji; Saito, Masazumi; Honjyo, Kuniaki; Hiraoka, Nobuyuki; Kishida, Tsunao; Mazda, Osam; Imanishi, Jiro; Kubo, Toshikazu

    2009-11-01

    To clarify the significance of subchondral bone and osteophytes in the pathology of osteoarthritis (OA), we investigated the expression of asporin (ASPN), transforming growth factor-beta1 (TGF-beta1), TGF-beta2, TGF-beta3, and runt-related transcription factor-2 (Runx2) genes involved in bone metabolism. Osteoblasts were isolated from 19 patients diagnosed with knee OA and from 4 patients diagnosed with femoral neck fracture. Osteoblast expression of mRNA encoding ASPN, TGF-beta1, TGF-beta2, TGF-beta3, and Runx2 was analyzed using real-time RT-PCR. Expression of ASPN, TGF-beta1, and TGF-beta3 mRNA in the subchondral bone and osteophytes of OA patients increased compared with that of non-OA patients. The ratio of ASPN to TGF-beta1 mRNA in patients with severe cartilage damage was higher than that in patients with mild cartilage damage. The increased ratio of ASPN mRNA to TGF-beta1 mRNA in patients with severe relative to mild cartilage damage indicates that increased ASPN mRNA expression was significantly associated with the severity of cartilage degeneration. This finding suggests that ASPN may regulate TGF-beta1-mediated factors in the development of OA, which may provide clues as to the underlying pathology of OA.

  18. A curvilinear effect of height on reproductive success in human males

    NARCIS (Netherlands)

    Stulp, G.; Pollet, T.V.; Verhulst, S.; Buunk, A.P.

    2012-01-01

    Human male height is associated with mate choice and intra-sexual competition, and therefore potentially with reproductive success. A literature review (n = 18) on the relationship between male height and reproductive success revealed a variety of relationships ranging from negative to curvilinear

  19. A curvilinear effect of height on reproductive success in human males

    NARCIS (Netherlands)

    Stulp, Gert; Pollet, Thomas V.; Verhulst, Simon; Buunk, Abraham P.

    Human male height is associated with mate choice and intra-sexual competition, and therefore potentially with reproductive success. A literature review (n = 18) on the relationship between male height and reproductive success revealed a variety of relationships ranging from negative to curvilinear

  20. A parallel overset-curvilinear-immersed boundary framework for simulating complex 3D incompressible flows

    Science.gov (United States)

    Borazjani, Iman; Ge, Liang; Le, Trung; Sotiropoulos, Fotis

    2013-01-01

    We develop an overset-curvilinear immersed boundary (overset-CURVIB) method in a general non-inertial frame of reference to simulate a wide range of challenging biological flow problems. The method incorporates overset-curvilinear grids to efficiently handle multi-connected geometries and increase the resolution locally near immersed boundaries. Complex bodies undergoing arbitrarily large deformations may be embedded within the overset-curvilinear background grid and treated as sharp interfaces using the curvilinear immersed boundary (CURVIB) method (Ge and Sotiropoulos, Journal of Computational Physics, 2007). The incompressible flow equations are formulated in a general non-inertial frame of reference to enhance the overall versatility and efficiency of the numerical approach. Efficient search algorithms to identify areas requiring blanking, donor cells, and interpolation coefficients for constructing the boundary conditions at grid interfaces of the overset grid are developed and implemented using efficient parallel computing communication strategies to transfer information among sub-domains. The governing equations are discretized using a second-order accurate finite-volume approach and integrated in time via an efficient fractional-step method. Various strategies for ensuring globally conservative interpolation at grid interfaces suitable for incompressible flow fractional step methods are implemented and evaluated. The method is verified and validated against experimental data, and its capabilities are demonstrated by simulating the flow past multiple aquatic swimmers and the systolic flow in an anatomic left ventricle with a mechanical heart valve implanted in the aortic position. PMID:23833331

  1. Christoffel symbols and inertia in flat space-time theory. [Curvilinear coordinate systems

    Energy Technology Data Exchange (ETDEWEB)

    Krause, J [Universidad Central de Venezuela, Caracas

    1976-11-01

    A necessary and sufficient criterion of inertia is presented, for the flat space-time theory of general frames of reference, in terms of the vanishing of some typical components of the affine connection pertaining to curvilinear coordinate systems. The physical identification of inertial forces thus arises in the context of the special theory of relativity.

  2. Time Pressure and Coworker Support Mediate the Curvilinear Relationship Between Age and Occupational Well-Being

    NARCIS (Netherlands)

    Zacher, Hannes; Jimmieson, Nerina L.; Bordia, Prashant

    2014-01-01

    As the proportion of older employees in the workforce is growing, researchers have become increasingly interested in the association between age and occupational well-being. The curvilinear nature of relationships between age and job satisfaction and between age and emotional exhaustion is

  3. The Curvilinear Association between Performance Measurement System Design and Strategic Performance

    DEFF Research Database (Denmark)

    Schneider, Melanie L.; Mahlendorf, Matthias D.; Schäffer, Utz

    This paper reconciles prior research regarding beneficial and detrimental effects of performance measurement system (PMS) design on performance by arguing for a curvilinear association. By taking the too-much-of-a-good-thing effect as a starting point, we challenge the assumption of a linear...

  4. Chrometric properties of curvilinear beam transport channels with reverses of longitudinal magnetic field

    International Nuclear Information System (INIS)

    Kapchinskij, M.I.; Korenev, I.L.; Roginskij, L.A.

    1990-01-01

    Dynamics of charged particle beams in curvilinear transport channels comprising sections with counter direction of longitudinal focusing magnetic field is considered. It is shown that such magnetic field reverses reduce sufficiently the particle deflections conditioned by momentum spread of longitudinal motion and their application allows one to completely project the achromatic channel

  5. Positivity and job burnout in emergency personnel: examining linear and curvilinear relationship

    Directory of Open Access Journals (Sweden)

    Basińska Beata Aleksandra

    2017-06-01

    Full Text Available The aim of this study was to examine whether the relationship between the ratio of job-related positive to negative emotions (positivity ratio and job burnout is best described as linear or curvilinear. Participants were 89 police officers (12% women and 86 firefighters. The positivity ratio was evaluated using the Job-related Affective Wellbeing Scale (Van Katwyk, Fox, Spector, & Kelloway, 2000. Exhaustion and disengagement, two components of job burnout, were measured using the Oldenburg Burnout Inventory (Demerouti, Mostert, & Bakker, 2010. The results of regression analysis revealed that curvilinear relationships between the positivity ratio and two components of job burnout appeared to better fit the data than linear relationships. The relationship between the positivity ratio and exhaustion was curvilinear with a curve point at around 2.1. A similar curvilinear relationship, but with a lower curve point, i.e., around 1.8, was observed for disengagement. It seems that beyond certain values there may be hidden costs of maintaining positive emotions at work. Also, the unequal curve points for subscales suggest that different dimensions of work-related functioning are variously prone to such costs.

  6. Threat Appeals: The Fear-Persuasion Relationship is Linear and Curvilinear.

    Science.gov (United States)

    Dillard, James Price; Li, Ruobing; Huang, Yan

    2017-11-01

    Drive theory may be seen as the first scientific theory of health and risk communication. However, its prediction of a curvilinear association between fear and persuasion is generally held to be incorrect. A close rereading of Hovland et al. reveals that within- and between-persons processes were conflated. Using a message that advocated obtaining a screening for colonoscopy, this study (N = 259) tested both forms of the inverted-U hypothesis. In the between-persons data, analyses revealed a linear effect that was consistent with earlier investigations. However, the data showed an inverted-U relationship in within-persons data. Hence, the relationship between fear and persuasion is linear or curvilinear depending on the level of analysis.

  7. 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.

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

    KAUST Repository

    Zemlyanova, A. Y.; Walton, J. R.

    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.

  9. Iterative Tensor Voting for Perceptual Grouping of Ill-Defined Curvilinear Structures: Application to Adherens Junctions

    Science.gov (United States)

    Loss, Leandro A.; Bebis, George; Parvin, Bahram

    2012-01-01

    In this paper, a novel approach is proposed for perceptual grouping and localization of ill-defined curvilinear structures. Our approach builds upon the tensor voting and the iterative voting frameworks. Its efficacy lies on iterative refinements of curvilinear structures by gradually shifting from an exploratory to an exploitative mode. Such a mode shifting is achieved by reducing the aperture of the tensor voting fields, which is shown to improve curve grouping and inference by enhancing the concentration of the votes over promising, salient structures. The proposed technique is applied to delineation of adherens junctions imaged through fluorescence microscopy. This class of membrane-bound macromolecules maintains tissue structural integrity and cell-cell interactions. Visually, it exhibits fibrous patterns that may be diffused, punctate and frequently perceptual. Besides the application to real data, the proposed method is compared to prior methods on synthetic and annotated real data, showing high precision rates. PMID:21421432

  10. Fast vibrational configuration interaction using generalized curvilinear coordinates and self-consistent basis.

    Science.gov (United States)

    Scribano, Yohann; Lauvergnat, David M; Benoit, David M

    2010-09-07

    In this paper, we couple a numerical kinetic-energy operator approach to the direct-vibrational self-consistent field (VSCF)/vibrational configuration interaction (VCI) method for the calculation of vibrational anharmonic frequencies. By combining this with fast-VSCF, an efficient direct evaluation of the ab initio potential-energy surface (PES), we introduce a general formalism for the computation of vibrational bound states of molecular systems exhibiting large-amplitude motion such as methyl-group torsion. We validate our approach on an analytical two-dimensional model and apply it to the methanol molecule. We show that curvilinear coordinates lead to a significant improvement in the VSCF/VCI description of the torsional frequency in methanol, even for a simple two-mode coupling expansion of the PES. Moreover, we demonstrate that a curvilinear formulation of the fast-VSCF/VCI scheme improves its speed by a factor of two and its accuracy by a factor of 3.

  11. Curvilinear relationships between resource allocation and life domain-specific interference.

    Science.gov (United States)

    Waldrop, Jessica S; Erb, Kaitlyn R; Grawitch, Matthew J

    2017-10-01

    This study investigated the inherent complexities of the work-life interface (WLI) by examining the relationship between resource allocation (i.e., time and energy dedicated to a particular domain) and perceived interference of individual life domains. Much of the research on the WLI is based on the assumption that a linear pattern best describes the relationship between resource allocation and the interference caused by various life domains; however, this study examined the possibility that curvilinear relationships may be a more appropriate representation. Results indicated that resource allocation is a meaningful predictor of interference, and for many life domains a curvilinear relationship accounts for more variance than a linear one; a breakdown of the sample also revealed this relationship varies by gender. Overall, findings suggest that the nature of the WLI is more individualized and complex than is currently conceptualized in the field. Copyright © 2016 John Wiley & Sons, Ltd.

  12. 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.

  13. Substance Use Disorder Counselors’ Job Performance and Turnover after 1 Year: Linear or Curvilinear Relationship?1

    Science.gov (United States)

    Laschober, Tanja C.; de Tormes Eby, Lillian Turner

    2013-01-01

    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. PMID:22527711

  14. Vector 33: A reduce program for vector algebra and calculus in orthogonal curvilinear coordinates

    Science.gov (United States)

    Harper, David

    1989-06-01

    This paper describes a package with enables REDUCE 3.3 to perform algebra and calculus operations upon vectors. Basic algebraic operations between vectors and between scalars and vectors are provided, including scalar (dot) product and vector (cross) product. The vector differential operators curl, divergence, gradient and Laplacian are also defined, and are valid in any orthogonal curvilinear coordinate system. The package is written in RLISP to allow algebra and calculus to be performed using notation identical to that for operations. Scalars and vectors can be mixed quite freely in the same expression. The package will be of interest to mathematicians, engineers and scientists who need to perform vector calculations in orthogonal curvilinear coordinates.

  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. 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.

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

    Science.gov (United States)

    Cannistraci, Carlo Vittorio; Ravasi, Timothy; Montevecchi, Franco Maria; Ideker, Trey; Alessio, Massimo

    2010-09-15

    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. '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. 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. 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. https://sites.google.com/site/carlovittoriocannistraci/home.

  18. Chemical reaction surface vibrational frequencies evaluated in curvilinear internal coordinates: Application to H + CH(4) H(2) + CH(3).

    Science.gov (United States)

    Banks, Simon T; Clary, David C

    2009-01-14

    We consider the general problem of vibrational analysis at nonglobally optimized points on a reduced dimensional reaction surface. We discuss the importance of the use of curvilinear internal coordinates to describe molecular motion and derive a curvilinear projection operator to remove the contribution of nonzero gradients from the Hessian matrix. Our projection scheme is tested in the context of a two-dimensional quantum scattering calculation for the reaction H + CH(4) --> H(2) + CH(3) and its reverse H(2) + CH(3) --> H + CH(4). Using zero-point energies calculated via rectilinear and curvilinear projections we construct two two-dimensional, adiabatically corrected, ab initio reaction surfaces for this system. It is shown that the use of curvilinear coordinates removes unphysical imaginary frequencies observed with rectilinear projection and leads to significantly improved thermal rate constants for both the forward and reverse reactions.

  19. 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.

  20. Orbit covariance propagation via quadratic-order state transition matrix in curvilinear coordinates

    Science.gov (United States)

    Hernando-Ayuso, Javier; Bombardelli, Claudio

    2017-09-01

    In this paper, an analytical second-order state transition matrix (STM) for relative motion in curvilinear coordinates is presented and applied to the problem of orbit uncertainty propagation in nearly circular orbits (eccentricity smaller than 0.1). The matrix is obtained by linearization around a second-order analytical approximation of the relative motion recently proposed by one of the authors and can be seen as a second-order extension of the curvilinear Clohessy-Wiltshire (C-W) solution. The accuracy of the uncertainty propagation is assessed by comparison with numerical results based on Monte Carlo propagation of a high-fidelity model including geopotential and third-body perturbations. Results show that the proposed STM can greatly improve the accuracy of the predicted relative state: the average error is found to be at least one order of magnitude smaller compared to the curvilinear C-W solution. In addition, the effect of environmental perturbations on the uncertainty propagation is shown to be negligible up to several revolutions in the geostationary region and for a few revolutions in low Earth orbit in the worst case.

  1. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model

    Science.gov (United States)

    Joh, Ju Youn; Kim, Sun; Park, Jun Li

    2013-01-01

    Background The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. Methods We used the data from 398 adolescent participants who were in middle school. A self-reported questionnaire was used to evaluate the FACES III and Youth Self Report. Results According to the level of family adaptability, significant differences were evident in internalizing problems (P = 0.014). But, in externalizing problems, the results were not significant (P = 0.305). Also, according to the level of family cohesion, significant differences were in internalizing problems (P = 0.002) and externalizing problems (P = 0.004). Conclusion The relationship between the dimensions of adaptability, cohesion and adolescent problem behaviors was not curvilinear. In other words, adolescents with high adaptability and high cohesion showed low problem behaviors. PMID:23730484

  2. Relationship between Family Adaptability, Cohesion and Adolescent Problem Behaviors: Curvilinearity of Circumplex Model.

    Science.gov (United States)

    Joh, Ju Youn; Kim, Sun; Park, Jun Li; Kim, Yeon Pyo

    2013-05-01

    The Family Adaptability and Cohesion Evaluation Scale (FACES) III using the circumplex model has been widely used in investigating family function. However, the criticism of the curvilinear hypothesis of the circumplex model has always been from an empirical point of view. This study examined the relationship between adolescent adaptability, cohesion, and adolescent problem behaviors, and especially testing the consistency of the curvilinear hypotheses with FACES III. We used the data from 398 adolescent participants who were in middle school. A self-reported questionnaire was used to evaluate the FACES III and Youth Self Report. According to the level of family adaptability, significant differences were evident in internalizing problems (P = 0.014). But, in externalizing problems, the results were not significant (P = 0.305). Also, according to the level of family cohesion, significant differences were in internalizing problems (P = 0.002) and externalizing problems (P = 0.004). The relationship between the dimensions of adaptability, cohesion and adolescent problem behaviors was not curvilinear. In other words, adolescents with high adaptability and high cohesion showed low problem behaviors.

  3. The role of subchondral bone remodeling in osteoarthritis: reduction of cartilage degeneration and prevention of osteophyte formation by alendronate in the rat anterior cruciate ligament transection model.

    Science.gov (United States)

    Hayami, Tadashi; Pickarski, Maureen; Wesolowski, Gregg A; McLane, Julia; Bone, Ashleigh; Destefano, James; Rodan, Gideon A; Duong, Le T

    2004-04-01

    It has been suggested that subchondral bone remodeling plays a role in the progression of osteoarthritis (OA). To test this hypothesis, we characterized the changes in the rat anterior cruciate ligament transection (ACLT) model of OA and evaluated the effects of alendronate (ALN), a potent inhibitor of bone resorption, on cartilage degradation and on osteophyte formation. Male Sprague-Dawley rats underwent ACLT or sham operation of the right knee. Animals were then treated with ALN (0.03 and 0.24 microg/kg/week subcutaneously) and necropsied at 2 or 10 weeks postsurgery. OA changes were evaluated. Subchondral bone volume and osteophyte area were measured by histomorphometric analysis. Coimmunostaining for transforming growth factor beta (TGF beta), matrix metalloproteinase 9 (MMP-9), and MMP-13 was performed to investigate the effect of ALN on local activation of TGF beta. ALN was chondroprotective at both dosages, as determined by histologic criteria and collagen degradation markers. ALN suppressed subchondral bone resorption, which was markedly increased 2 weeks postsurgery, and prevented the subsequent increase in bone formation 10 weeks postsurgery, in the untreated tibial plateau of ACLT joints. Furthermore, ALN reduced the incidence and area of osteophytes in a dose-dependent manner. ALN also inhibited vascular invasion into the calcified cartilage in rats with OA and blocked osteoclast recruitment to subchondral bone and osteophytes. ALN treatment reduced the local release of active TGF beta, possibly via inhibition of MMP-13 expression in articular cartilage and MMP-9 expression in subchondral bone. Subchondral bone remodeling plays an important role in the pathogenesis of OA. ALN or other inhibitors of bone resorption could potentially be used as disease-modifying agents in the treatment of OA.

  4. Hand joint space narrowing and osteophytes are associated with magnetic resonance imaging-defined knee cartilage thickness and radiographic knee osteoarthritis: data from the Osteoarthritis Initiative.

    Science.gov (United States)

    Haugen, Ida K; Cotofana, Sebastian; Englund, Martin; Kvien, Tore K; Dreher, Donatus; Nevitt, Michael; Lane, Nancy E; Eckstein, Felix

    2012-01-01

    To evaluate whether features of radiographic hand osteoarthritis (OA) are associated with quantitative magnetic resonance imaging (MRI)-defined knee cartilage thickness, radiographic knee OA, and 1-year structural progression. A total of 765 participants in Osteoarthritis Initiative (OAI; 455 women, mean age 62.5 yrs, SD 9.4) obtained hand radiographs (at baseline), knee radiographs (baseline and Year 1), and knee MRI (baseline and Year 1). Hand radiographs were scored for presence of osteophytes and joint space narrowing (JSN). Knee radiographs were scored according to the Kellgren-Lawrence (KL) scale. Cartilage thickness in the medial and lateral femorotibial compartments was measured quantitatively from coronal FLASHwe images. We examined the cross-sectional and longitudinal associations between features of hand OA (total osteophyte and JSN scores) and knee cartilage thickness, 1-year knee cartilage thinning (above smallest detectable change), presence of knee OA (KL grade ≥ 3), and progression of knee OA (KL change ≥ 1) by linear and logistic regression. Both hand OA features were included in a multivariate model (if p ≤ 0.25) adjusted for age, sex, and body mass index (BMI). Hand JSN was associated with reduced knee cartilage thickness (ß = -0.02, 95% CI -0.03, -0.01) in the medial femorotibial compartment, while hand osteophytes were associated with the presence of radiographic knee OA (OR 1.10, 95% CI 1.03-1.18; multivariate models) with both hand OA features as independent variables adjusted for age, sex, and BMI). Radiographic features of hand OA were not associated with 1-year cartilage thinning or radiographic knee OA progression. Our results support a systemic OA susceptibility and possibly different mechanisms for osteophyte formation and cartilage thinning.

  5. Beauty parlor stroke syndrome due to a bone fragment from an osteophyte of the atlas: case report.

    Science.gov (United States)

    Kameda, Takuya; Otani, Koji; Tamura, Takamitsu; Konno, Shinichi

    2018-04-01

    Beauty parlor stroke syndrome (BPSS) is a rare condition characterized by mechanical impingement of a vertebral artery (VA) during neck rotation and/or hyperextension followed by vertebrobasilar insufficiency. However, there have been no reports of BPSS in which the cause of mechanical impingement was identified and no cases for which surgical treatment was reported. The authors report the case of a 56-year-old Japanese man who presented with presyncope that occurred during cervical extension. Given the possibility of vertebrobasilar insufficiency, digital subtraction angiography and CT angiography were performed. These studies revealed that the right VA was hypoplastic and the left VA was dominant. Moreover, in the position of cervical extension, the dominant left VA showed constriction caused by a bone fragment of an osteophyte of the atlas. Removal of the bone fragment was performed. Postoperative left vertebral angiography showed improvement of blood flow in the extended position, and the presyncope completely disappeared. The pathomechanism of this case was a bone fragment compressing the left VA in the C-1 groove during neck extension. In BPSS patients with recurrent transient symptoms, the possibility of this mechanism of VA constriction by a free bone fragment should be considered.

  6. 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.)

  7. 3-T MRI assessment of osteophyte formation in patients with unilateral anterior cruciate ligament injury and reconstruction

    International Nuclear Information System (INIS)

    Panzer, Stephanie; Augat, Peter; Atzwanger, Joerg; Hergan, Klaus

    2012-01-01

    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.)

  8. Why allometric variation in mammalian metabolism is curvilinear on the logarithmic scale.

    Science.gov (United States)

    Packard, Gary C

    2017-11-01

    Studies performed over the last 20 years have repeatedly documented a slight convex curvature (relative to the x-axis) in double-logarithmic plots of basal metabolic rate (BMR) versus body mass in mammals. This curvilinear pattern has usually been interpreted in the context of a simple, two-parameter power function on the arithmetic scale, y  =  a  ×  x b , with the exponent in the equation supposedly increasing systematically with body size. An equation of this form has caused concern among ecologists because a variable exponent is inconsistent with an assumption underlying the metabolic theory of ecology (MTE). However, the appearance of an exponent that varies with body size is an artifact resulting from the widespread use of logarithmic transformations in allometric analyses. Curvature in the distribution on the logarithmic scale actually is caused by a requirement for an explicit, non-zero intercept-and not a variable exponent-in the model describing the distribution on the arithmetic scale. Thus, the MTE need not be revised to accommodate an exponent that varies with body size in the scaling of mammalian BMR, but the theory may need to be tweaked to accommodate an intercept in the allometric equation. In general, any bivariate dataset that is well described by a three-parameter power equation on the arithmetic scale will follow a curvilinear path when displayed on the logarithmic scale. Consequently, reports of curvilinearity in log domain (i.e., "complex allometry") need to be revisited because conclusions from those investigations are likely to be flawed. © 2018 Wiley Periodicals, Inc.

  9. 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.

  10. X-ray adapter with four freedom degrees for the curvilinear surface study

    International Nuclear Information System (INIS)

    Barakhtin, B.K.; Petrov, P.P.; Moskvin, A.I.

    1989-01-01

    Four-freedom degree adapter, which is placed on goniometer of DRON X-ray diffractometer is described. The adapter consists of specimen spring holder, worm pair, which provides for specimen turning by 360 deg, as well as, of three coordination tables. Investigations of prestressed-deformed state of near-the-surface layer of curvilinear surface units and structures are carried out using X-ray diffractometer equipped with the adapter described. Determination accuracy of residual stresses at the surface of turbine vane is no worse, than ±50 MPa

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

    International Nuclear Information System (INIS)

    Cheng Min; Tang Tiantong; Lu Yilong; Yao Zhenhua

    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

  12. ALPHA-CTX is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis

    Science.gov (United States)

    Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

    2014-01-01

    Objective To evaluate joint tissue remodeling, with urinary collagen biomarkers, uALPHA CTX and uCTXII, and their association with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Methods Participants (N=149) with symptomatic and radiographic knee OA underwent fixed flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, scored semi-quantitatively for osteophyte (OST) and joint space narrowing (JSN) severity and uptake intensity with scores summed across knees. Urinary concentrations of ALPHA CTX and CTXII were determined by ELISA. Immunohistochemistry of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Results uALPHA CTX correlated strongly with intensity of bone scintigraphic uptake, and JSN and OST progression (risk ratio=13.2 and 3, respectively). uCTXII was strongly associated with intensity of bone scintigraphic uptake, with JSN and OST severity, and OA progression based on OST. uALPHA CTX localized primarily to high bone turnover areas in subchondral bone; CTXII localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Conclusion Baseline uALPHA CTX, localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees signified by scintigraphy, and progression of both OST and JSN. uCTXII correlated with JSN and OST severity, and progression of OST. To our knowledge, this represents the first report of serological markers reflecting subchondral bone turnover. These collagen markers may be useful for non-invasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA. PMID:24909851

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mezzacappa, Anthony [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Endeve, Eirik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hauck, Cory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xing, Yulong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-02-01

    We extend the positivity-preserving method of Zhang & Shu [49] 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 stabilitypreserving, 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 ϵ [0, 1]. The combination of suitable CFL conditions and the use of the high-order limiter proposed in [49] is su cient 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 divergencefree property of the phase space ow. Proofs that highlight the necessary conditions are presented for general curvilinear coordinates, and the details of these conditions are worked out for some commonly used coordinate systems (i.e., spherical polar spatial coordinates in spherical symmetry and cylindrical spatial coordinates in axial symmetry, both with spherical momentum coordinates). Results from numerical experiments - including one example in spherical symmetry adopting the Schwarzschild metric - demonstrate that the method achieves high-order accuracy and that the distribution function satisfies the maximum principle.

  15. An arbitrary curvilinear-coordinate method for particle-in-cell modeling

    International Nuclear Information System (INIS)

    Fichtl, C A; Finn, J M; Cartwright, K L

    2012-01-01

    A new approach to kinetic simulation of plasmas in complex geometries, based on the particle-in-cell (PIC) simulation method, is explored. In the two-dimensional (2D) electrostatic version of our method, called the arbitrary curvilinear-coordinate PIC method, all essential PIC operations are carried out in 2D on a uniform grid on the unit square logical domain, and mapped to a nonuniform boundary-fitted grid on the physical domain. As the resulting logical grid equations of motion are not separable, we have developed an extension of the semi-implicit modified leapfrog integration technique to preserve the symplectic nature of the logical grid particle mover. A generalized, curvilinear-coordinate formulation of Poisson's equations to solve for the electrostatic fields on the uniform logical grid is also developed. By our formulation, we compute the plasma charge density on the logical grid based on the particles' positions on the logical domain. That is, the plasma particles are weighted to the uniform logical grid and the self-consistent mean electrostatic fields obtained from the solution of the logical grid Poisson equation are interpolated to the particle positions on the logical grid. This process eliminates the complexity associated with the weighting and interpolation processes on the nonuniform physical grid and allows us to run the PIC method on arbitrary boundary-fitted meshes. (paper)

  16. Model-based MPC enables curvilinear ILT using either VSB or multi-beam mask writers

    Science.gov (United States)

    Pang, Linyong; Takatsukasa, Yutetsu; Hara, Daisuke; Pomerantsev, Michael; Su, Bo; Fujimura, Aki

    2017-07-01

    Inverse Lithography Technology (ILT) is becoming the choice for Optical Proximity Correction (OPC) of advanced technology nodes in IC design and production. Multi-beam mask writers promise significant mask writing time reduction for complex ILT style masks. Before multi-beam mask writers become the main stream working tools in mask production, VSB writers will continue to be the tool of choice to write both curvilinear ILT and Manhattanized ILT masks. To enable VSB mask writers for complex ILT style masks, model-based mask process correction (MB-MPC) is required to do the following: 1). Make reasonable corrections for complex edges for those features that exhibit relatively large deviations from both curvilinear ILT and Manhattanized ILT designs. 2). Control and manage both Edge Placement Errors (EPE) and shot count. 3. Assist in easing the migration to future multi-beam mask writer and serve as an effective backup solution during the transition. In this paper, a solution meeting all those requirements, MB-MPC with GPU acceleration, will be presented. One model calibration per process allows accurate correction regardless of the target mask writer.

  17. Iterative tensor voting for perceptual grouping of ill-defined curvilinear structures.

    Science.gov (United States)

    Loss, Leandro A; Bebis, George; Parvin, Bahram

    2011-08-01

    In this paper, a novel approach is proposed for perceptual grouping and localization of ill-defined curvilinear structures. Our approach builds upon the tensor voting and the iterative voting frameworks. Its efficacy lies on iterative refinements of curvilinear structures by gradually shifting from an exploratory to an exploitative mode. Such a mode shifting is achieved by reducing the aperture of the tensor voting fields, which is shown to improve curve grouping and inference by enhancing the concentration of the votes over promising, salient structures. The proposed technique is validated on delineating adherens junctions that are imaged through fluorescence microscopy. However, the method is also applicable for screening other organisms based on characteristics of their cell wall structures. Adherens junctions maintain tissue structural integrity and cell-cell interactions. Visually, they exhibit fibrous patterns that may be diffused, heterogeneous in fluorescence intensity, or punctate and frequently perceptual. Besides the application to real data, the proposed method is compared to prior methods on synthetic and annotated real data, showing high precision rates.

  18. A curvilinear, fully implicit, conservative electromagnetic PIC algorithm in multiple dimensions

    Science.gov (United States)

    Chacón, L.; Chen, G.

    2016-07-01

    We extend a recently proposed fully implicit PIC algorithm for the Vlasov-Darwin model in multiple dimensions (Chen and Chacón (2015) [1]) to curvilinear geometry. As in the Cartesian case, the approach is based on a potential formulation (ϕ, A), and overcomes many difficulties of traditional semi-implicit Darwin PIC algorithms. Conservation theorems for local charge and global energy are derived in curvilinear representation, and then enforced discretely by a careful choice of the discretization of field and particle equations. Additionally, the algorithm conserves canonical-momentum in any ignorable direction, and preserves the Coulomb gauge ∇ ṡ A = 0 exactly. An asymptotically well-posed fluid preconditioner allows efficient use of large cell sizes, which are determined by accuracy considerations, not stability, and can be orders of magnitude larger than required in a standard explicit electromagnetic PIC simulation. We demonstrate the accuracy and efficiency properties of the algorithm with numerical experiments in mapped meshes in 1D-3V and 2D-3V.

  19. Development of a computational environment for the General Curvilinear Ocean Model

    International Nuclear Information System (INIS)

    Thomas, Mary P; Castillo, Jose E

    2009-01-01

    The General Curvilinear Ocean Model (GCOM) differs significantly from the traditional approach, where the use of Cartesian coordinates forces the model to simulate terrain as a series of steps. GCOM utilizes a full three-dimensional curvilinear transformation, which has been shown to have greater accuracy than similar models and to achieve results more efficiently. The GCOM model has been validated for several types of water bodies, different coastlines and bottom shapes, including the Alarcon Seamount, Southern California Coastal Region, the Valencia Lake in Venezuela, and more recently the Monterey Bay. In this paper, enhancements to the GCOM model and an overview of the computational environment (GCOM-CE) are presented. Model improvements include migration from F77 to F90; approach to a component design; and initial steps towards parallelization of the model. Through the use of the component design, new models are being incorporated including biogeochemical, pollution, and sediment transport. The computational environment is designed to allow various client interactions via secure Web applications (portal, Web services, and Web 2.0 gadgets). Features include building jobs, managing and interacting with long running jobs; managing input and output files; quick visualization of results; publishing of Web services to be used by other systems such as larger climate models. The CE is based mainly on Python tools including a grid-enabled Pylons Web application Framework for Web services, pyWSRF (python-Web Services-Resource Framework), pyGlobus based web services, SciPy, and Google code tools.

  20. 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.

  1. An efficient mode-splitting method for a curvilinear nearshore circulation model

    Science.gov (United States)

    Shi, Fengyan; Kirby, James T.; Hanes, Daniel M.

    2007-01-01

    A mode-splitting method is applied to the quasi-3D nearshore circulation equations in generalized curvilinear coordinates. The gravity wave mode and the vorticity wave mode of the equations are derived using the two-step projection method. Using an implicit algorithm for the gravity mode and an explicit algorithm for the vorticity mode, we combine the two modes to derive a mixed difference–differential equation with respect to surface elevation. McKee et al.'s [McKee, S., Wall, D.P., and Wilson, S.K., 1996. An alternating direction implicit scheme for parabolic equations with mixed derivative and convective terms. J. Comput. Phys., 126, 64–76.] ADI scheme is then used to solve the parabolic-type equation in dealing with the mixed derivative and convective terms from the curvilinear coordinate transformation. Good convergence rates are found in two typical cases which represent respectively the motions dominated by the gravity mode and the vorticity mode. Time step limitations imposed by the vorticity convective Courant number in vorticity-mode-dominant cases are discussed. Model efficiency and accuracy are verified in model application to tidal current simulations in San Francisco Bight.

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

    KAUST Repository

    Jiang, Qiu; Kurra, Narendra; Alshareef, Husam N.

    2015-01-01

    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.

  3. Wave propagations of curvilinear motors driven by partially laminated piezoelectric actuators

    International Nuclear Information System (INIS)

    Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Muensit, Supasarote; Tzou, Horn-Sen

    2008-01-01

    A piezoelectric arc stator is the key component delivering driving actions to an ultrasonic curvilinear motor. The arc stator drives the rotor along the arc structure to any specific angular position. Usually conventional stators in ultrasonic motors are fully bounded with piezoelectric patch actuators. To reduce production costs while maintaining similar driving characteristics, an arc stator partially bonded with piezoelectric actuators is proposed and its dynamic characteristics are analyzed in this study. The effect of actuator locations on the wave propagation is investigated. Both analytical and finite element results demonstrate similar dynamic responses. That is, the response of the wave propagation depends on specific locations of piezoelectric actuators. One of the two configurations investigated shows that the partially laminated piezoelectric actuator pattern can also generate rather steady traveling waves on the stator with consistent wave amplitude. This implies that the partially laminated actuator technique could be an alternative actuator pattern to the fully laminated actuators in the design of ultrasonic curvilinear motors or other finite-length ultrasonic motors

  4. Fast pressure-correction method for incompressible Navier-Stokes equations in curvilinear coordinates

    Science.gov (United States)

    Aithal, Abhiram; Ferrante, Antonino

    2017-11-01

    In order to perform direct numerical simulations (DNS) of turbulent flows over curved surfaces and axisymmetric bodies, we have developed the numerical methodology to solve the incompressible Navier-Stokes (NS) equations in curvilinear coordinates for orthogonal meshes. The orthogonal meshes are generated by solving a coupled system of non-linear Poisson equations. The NS equations in orthogonal curvilinear coordinates are discretized in space on a staggered mesh using second-order central-difference scheme and are solved with an FFT-based pressure-correction method. The momentum equation is integrated in time using the second-order Adams-Bashforth scheme. The velocity field is advanced in time by applying the pressure correction to the approximate velocity such that it satisfies the divergence free condition. The novelty of the method stands in solving the variable coefficient Poisson equation for pressure using an FFT-based Poisson solver rather than the slower multigrid methods. We present the verification and validation results of the new numerical method and the DNS results of transitional flow over a curved axisymmetric body.

  5. High order curvilinear finite elements for elastic–plastic Lagrangian dynamics

    International Nuclear Information System (INIS)

    Dobrev, Veselin A.; Kolev, Tzanio V.; Rieben, Robert N.

    2014-01-01

    This paper presents a high-order finite element method for calculating elastic–plastic flow on moving curvilinear meshes and is an extension of our general high-order curvilinear finite element approach for solving the Euler equations of gas dynamics in a Lagrangian frame [1,2]. In order to handle transition to plastic flow, we formulate the stress–strain relation in rate (or incremental) form and augment our semi-discrete equations for Lagrangian hydrodynamics with an additional evolution equation for the deviatoric stress which is valid for arbitrary order spatial discretizations of the kinematic and thermodynamic variables. The semi-discrete equation for the deviatoric stress rate is developed for 2D planar, 2D axisymmetric and full 3D geometries. For each case, the strain rate is approximated via a collocation method at zone quadrature points while the deviatoric stress is approximated using an L 2 projection onto the thermodynamic basis. We apply high order, energy conserving, explicit time stepping methods to the semi-discrete equations to develop the fully discrete method. We conclude with numerical results from an extensive series of verification tests that demonstrate several practical advantages of using high-order finite elements for elastic–plastic flow

  6. Curvature-insensitive methodology for thermal-wave depth-profilometry in multi-layered curvilinear solids

    International Nuclear Information System (INIS)

    Liu Liwang; Wang Chinhua; Yuan Xiao; Mandelis, Andreas

    2010-01-01

    A generalized similarity normalization (SN) methodology for characterizing depth profiles of continuously varying thermophysical properties in curvilinear (cylindrical and spherical) solids is presented. Specifically, the principle and the physical mechanism of the elimination of the surface curvature effect from the overall photothermal signal is introduced based on theoretical models of cylindrical, spherical and flat solids with multi-layer structures. The effects of the relative values of radii of curvature of the curvilinear solid, the thickness of the inhomogeneous surface layer and the measurement azimuthal angle on the validity of the technique are discussed in detail. Experimental reconstructions of thermophysical depth profiles of hardened cylindrical steel rods of various diameters are performed based on both curvilinear theory and the equivalent flat surface theory. The reconstructed results are compared and validated.

  7. Solar radiation control using nematic curvilinear aligned phase (NCAP) liquid crystal technology

    Science.gov (United States)

    vanKonynenburg, Peter; Marsland, Stephen; McCoy, James

    1987-11-01

    A new, advanced liquid crystal technology has made economical, large area, electrically-controlled windows a commercial reality. The new technology, Nematic Curvilinear Aligned Phase (NCAP), is based on a polymeric material containing small droplets of nematic liquid crystal which is coated and laminated between transparent electrodes and fabricated into large area field effect devices. NCAP windows feature variable solar transmission and reflection through a voltage-controlled scattering mechanism. Laminated window constructions provide the excellent transmission and visibility of glass in the powered condition. In the unpowered condition, the windows are highly translucent, and provide 1) blocked vision for privacy, security, and obscuration of information, and 2) glare control and solar shading. The stability is excellent during accelerated aging tests. Degradation mechanisms which can limit performance and lifetime are discussed. Maximum long term stability is achieved by product designs that incorporate the appropriate window materials to provide environmental protection.

  8. Development of intuitive theories of motion - Curvilinear motion in the absence of external forces

    Science.gov (United States)

    Kaiser, M. K.; Mccloskey, M.; Proffitt, D. R.

    1986-01-01

    College students and children between the ages of 4 and 12 were asked to draw the path a ball would take upon exiting a curved tube. As in previous studies, many subjects erroneously predicted curvilinear paths. However, a clear U-shaped curve was evident in the data: Preschoolers and kindergartners performed as well as college students, whereas school-aged children were more likely to make erroneous predictions. A second study suggested that the youngest children's correct responses could not be attributed to response biases or drawing abilities. This developmental trend is interpreted to mean that the school-aged children are developing intuitive theories of motion that include erroneous principles. The results are related to the 'growth errors' found in other cognitive domains and to the historical development of formal theories of motion.

  9. Robustness of an artificially tailored fisheye imaging system with a curvilinear image surface

    Science.gov (United States)

    Lee, Gil Ju; Nam, Won Il; Song, Young Min

    2017-11-01

    Curved image sensors inspired by animal and insect eyes have provided a new development direction in next-generation digital cameras. It is known that natural fish eyes afford an extremely wide field of view (FOV) imaging due to the geometrical properties of the spherical lens and hemispherical retina. However, its inherent drawbacks, such as the low off-axis illumination and the fabrication difficulty of a 'dome-like' hemispherical imager, limit the development of bio-inspired wide FOV cameras. Here, a new type of fisheye imaging system is introduced that has simple lens configurations with a curvilinear image surface, while maintaining high off-axis illumination and a wide FOV. Moreover, through comparisons with commercial conventional fisheye designs, it is determined that the volume and required number of optical elements of the proposed design is practical while capturing the fundamental optical performances. Detailed design guidelines for tailoring the proposed optic system are also discussed.

  10. What breaks a leader: the curvilinear relation between assertiveness and leadership.

    Science.gov (United States)

    Ames, Daniel R; Flynn, Francis J

    2007-02-01

    The authors propose that individual differences in assertiveness play a critical role in perceptions about leaders. In contrast to prior work that focused on linear effects, the authors argue that individuals seen either as markedly low in assertiveness or as high in assertiveness are generally appraised as less effective leaders. Moreover, the authors claim that observers' perceptions of leaders as having too much or too little assertiveness are widespread. The authors linked the curvilinear effects of assertiveness to underlying tradeoffs between social outcomes (a high level of assertiveness worsens relationships) and instrumental outcomes (a low level of assertiveness limits goal achievement). In 3 studies, the authors used qualitative and quantitative approaches and found support for their account. The results suggest that assertiveness (and other constructs with nonlinear effects) might have been overlooked in research that has been focused on identifying what makes a leader rather than on identifying what breaks a leader. ((c) 2007 APA, all rights reserved).

  11. Curvilinear steel elements in load-bearing structures of high-rise building spatial frames

    Directory of Open Access Journals (Sweden)

    Ibragimov Alexander

    2018-01-01

    Full Text Available The application of curvilinear elements in load-bearing metal structures of high-rise buildings supposes ensuring of their bearing capacity and serviceability. There may exist a great variety of shapes and orientations of such structural elements. In particular, it may be various flat curves of an open or closed oval profile such as circular or parabolic arch or ellipse. The considered approach implies creating vast internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in "skyscraper" type buildings contributes to resolving a great number of problems, including those of communicative nature. The calculation results confirm the basic assumptions.

  12. Curvilinear steel elements in load-bearing structures of high-rise building spatial frames

    Science.gov (United States)

    Ibragimov, Alexander; Danilov, Alexander

    2018-03-01

    The application of curvilinear elements in load-bearing metal structures of high-rise buildings supposes ensuring of their bearing capacity and serviceability. There may exist a great variety of shapes and orientations of such structural elements. In particular, it may be various flat curves of an open or closed oval profile such as circular or parabolic arch or ellipse. The considered approach implies creating vast internal volumes without loss in the load-bearing capacity of the frame. The basic concept makes possible a wide variety of layout and design solutions. The presence of free internal spaces of large volume in "skyscraper" type buildings contributes to resolving a great number of problems, including those of communicative nature. The calculation results confirm the basic assumptions.

  13. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    International Nuclear Information System (INIS)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-01-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  14. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    Science.gov (United States)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-06-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  15. Accuracy of 3-dimensional curvilinear measurements on digital models with intraoral scanners.

    Science.gov (United States)

    Mack, Spencer; Bonilla, Tammy; English, Jeryl D; Cozad, Benjamin; Akyalcin, Sercan

    2017-09-01

    Our objectives were to evaluate and compare the digital dental models generated from 2 commercial intraoral scanners with manual measurements when performing 3-dimensional surface measurements along a curved line (curvilinear). Dry mandibles (n = 61) with intact dentition were used. The mandibles were digitized using 2 chair-side intraoral scanners: Cadent iTero (Align Technology, San Jose, Calif) and Lythos Digital Impression system (Ormco, Orange, Calif). Digitized 3-dimensional models were converted to individual stereolithography files and used with commercial software to obtain the curvilinear measurements. Manual measurements were carried out directly on the mandibular teeth. Measurements were made on different locations on the dental arch in various directions. One-sample t tests and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P 0.05). Bland-Altman analysis showed no fixed bias of 1 approach vs the other, and random errors were detected in all comparisons. Although the mean biases of the digital models obtained by the iTero and Lythos scanners, when compared with direct caliper measurements, were low, the comparison of the 2 intraoral scanners yielded the lowest mean bias. No comparison displayed statistical significance for the t scores; this indicated the absence of proportional bias in these comparisons. The intraoral scanners tested in this study produced digital dental models that were comparatively accurate when performing direct surface measurements along a curved line in 3 dimensions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  16. 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

  17. 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…

  18. Application of the Fourier pseudospectral time-domain method in orthogonal curvilinear coordinates for near-rigid moderately curved surfaces.

    Science.gov (United States)

    Hornikx, Maarten; Dragna, Didier

    2015-07-01

    The Fourier pseudospectral time-domain method is an efficient wave-based method to model sound propagation in inhomogeneous media. One of the limitations of the method for atmospheric sound propagation purposes is its restriction to a Cartesian grid, confining it to staircase-like geometries. A transform from the physical coordinate system to the curvilinear coordinate system has been applied to solve more arbitrary geometries. For applicability of this method near the boundaries, the acoustic velocity variables are solved for their curvilinear components. The performance of the curvilinear Fourier pseudospectral method is investigated in free field and for outdoor sound propagation over an impedance strip for various types of shapes. Accuracy is shown to be related to the maximum grid stretching ratio and deformation of the boundary shape and computational efficiency is reduced relative to the smallest grid cell in the physical domain. The applicability of the curvilinear Fourier pseudospectral time-domain method is demonstrated by investigating the effect of sound propagation over a hill in a nocturnal boundary layer. With the proposed method, accurate and efficient results for sound propagation over smoothly varying ground surfaces with high impedances can be obtained.

  19. How Orthogonal Are the Big Two of Social Perception? On the Curvilinear Relation Between Agency and Communion.

    Science.gov (United States)

    Imhoff, Roland; Koch, Alex

    2017-01-01

    Humans make sense of their social environment by forming impressions of others that allow predicting others' actions. In this process of social perception, two types of information carry pivotal importance: other entities' communion (i.e., warmth and trustworthiness) and agency (i.e., status and power). Although commonly thought of as orthogonal dimensions, we propose that these Big Two of social perception are curvilinearly related. Specifically, as we delineate from four different theoretical explanations, impressions of communion should peak at average agency, while entities too high or too low on agency should be perceived as low on communion. We show this pattern for social groups across one novel and five previously published data sets, including a meta-analysis of the most comprehensive data collection in the group perception literature, consisting of 36 samples from more than 20 countries. Addressing the generalizability of this curvilinear relation, we then report recent and unpublished experiments establishing the effect for the perception of individuals and animals. On the basis of the proposed curvilinear relation, we revisit the primacy of processing communion (rather than agency) information. Finally, we discuss the possibility of a more general curvilinear relation between communion and dimensions other than agency.

  20. Restoration of lumbopelvic sagittal alignment and its maintenance following transforaminal lumbar interbody fusion (TLIF): comparison between straight type versus curvilinear type cage.

    Science.gov (United States)

    Kim, Jong-Tae; Shin, Myung-Hoon; Lee, Ho-Jin; Choi, Du-Yong

    2015-11-01

    To evaluate a radiological and clinical difference between the curvilinear type cages compared to the straight type cages for the restoration of lumbopelvic sagittal alignment and its maintenance after transforaminal lumbar interbody fusion (TLIF) procedure. 68 patients who underwent single-level TLIF using either the straight type or curvilinear type cage were retrospectively reviewed. Assessment of the lumbopelvic parameters and the height of disc space was performed before surgery as well as 2 days, 6 and 12 months after surgery. Clinical outcome was assessed using VAS and ODI. The curvilinear type cages were positioned more anteriorly than the straight type. Restoration of the segmental lordosis (SL) in the curvilinear group was significantly greater than the straight group and at 12 months of follow-up, the straight group showed greater decrease in the disc height than the curvilinear group. The straight group failed to show improvement of lumbar lordosis (LL), while the curvilinear group showed significant restoration of LL and could maintain it to the 6 months of follow-up. In both groups, pelvic tilt was significantly decreased and it lasted to 6 months in the straight group; whereas in the curvilinear group, it was maintained to the last follow-up of 12 months. There were no significant differences between the two groups in mean VAS and ODI score over the follow-up period. This study demonstrates that the curvilinear type cage is superior to the straight type cage in improving the SL and maintaining both the restored lumbopelvic parameters and elevated disc height. These results could be attributable to the anterior position of the curvilinear cage which permits easy restoration of segmental lordosis and less sinking of cages.

  1. Application of a Steady Meandering River with Piers Using a Lattice Boltzmann Sub-Grid Model in Curvilinear Coordinate Grid

    Directory of Open Access Journals (Sweden)

    Liping Chen

    2018-05-01

    Full Text Available A sub-grid multiple relaxation time (MRT lattice Boltzmann model with curvilinear coordinates is applied to simulate an artificial meandering river. The method is based on the D2Q9 model and standard Smagorinsky sub-grid scale (SGS model is introduced to simulate meandering flows. The interpolation supplemented lattice Boltzmann method (ISLBM and the non-equilibrium extrapolation method are used for second-order accuracy and boundary conditions. The proposed model was validated by a meandering channel with a 180° bend and applied to a steady curved river with piers. Excellent agreement between the simulated results and previous computational and experimental data was found, showing that MRT-LBM (MRT lattice Boltzmann method coupled with a Smagorinsky sub-grid scale (SGS model in a curvilinear coordinates grid is capable of simulating practical meandering flows.

  2. The Curvilinear Relationship between Age and Emotional Aperture: The Moderating Role of Agreeableness

    Directory of Open Access Journals (Sweden)

    Anna Faber

    2017-07-01

    Full Text Available The capability to correctly recognize collective emotion expressions [i.e., emotional aperture (EA] is crucial for effective social and work-related interactions. Yet, little remains known about the antecedents of this ability. The present study therefore aims to shed new light onto key aspects that may promote or diminish an individual’s EA. We examine the role of age for this ability in an online sample of 181 participants (with an age range of 18–72 years, located in Germany, and we investigate agreeableness as a key contingency factor. Among individuals with lower agreeableness, on the one hand, our results indicate a curvilinear relationship between age and EA, such that EA remains at a relatively high level until these individuals’ middle adulthood (with a slight increase until their late 30s and declines afterward. Individuals with higher agreeableness, on the other hand, exhibit relatively high EA irrespective of their age. Together, these findings offer new insights for the emerging literature on EA, illustrating that specific demographic and personality characteristics may jointly shape such collective emotion recognition.

  3. Geometric variations in high index-contrast waveguides, coupled mode theory in curvilinear coordinates.

    Science.gov (United States)

    Skorobogatiy, Maksim; Jacobs, Steven; Johnson, Steven; Fink, Yoel

    2002-10-21

    Perturbation theory formulation of Maxwell's equations gives a theoretically elegant and computationally efficient way of describing small imperfections and weak interactions in electro-magnetic systems. It is generally appreciated that due to the discontinuous field boundary conditions in the systems employing high dielectric contrast profiles standard perturbation formulations fail when applied to the problem of shifted material boundaries. In this paper we developed a novel coupled mode and perturbation theory formulations for treating generic non-uniform (varying along the direction of propagation) perturbations of a waveguide cross-section based on Hamiltonian formulation of Maxwell equations in curvilinear coordinates. We show that our formulation is accurate and rapidly converges to an exact result when used in a coupled mode theory framework even for the high index-contrast discontinuous dielectric profiles. Among others, our formulation allows for an efficient numerical evaluation of induced PMD due to a generic distortion of a waveguide profile, analysis of mode filters, mode converters and other optical elements such as strong Bragg gratings, tapers, bends etc., and arbitrary combinations of thereof. To our knowledge, this is the first time perturbation and coupled mode theories are developed to deal with arbitrary non-uniform profile variations in high index-contrast waveguides.

  4. Numerical study of elastic turbulence in a 3D curvilinear micro-channel

    Science.gov (United States)

    Zhang, Hongna; Kunugi, Tomoaki; Li, Fengchen

    2012-11-01

    Elastic turbulence is an intriguing phenomenon of viscoelastic fluid flow, and dominated by the strong nonlinear elasticity due to the existence of flexible microstructures. It implies the possibility to generate a turbulent state (so-called an elastic turbulence) in the micro-scale devices by introducing the viscoelastic fluids, which could significantly enhance the mixing efficiency therein. Several experiments have been carried out to study its characteristics and underlying physics. However, the difficulty in measuring the flow information and behaviors of the microstructures, especially in the cross section normal to the mean flow direction, limits our current understanding and controlling. In the present study, the nondimensionalization method in which the characteristic velocity is defined as the ratio of the solution viscosity to the width of the channel was adopted to simulate the elastic turbulence in the micro-scale devices. And the elastic turbulent flow was obtained numerically in the 3D curvilinear micro-channel. Therein, the characteristics of the velocity field and polymer's behavior are discussed. Moreover, the energy transfer between the kinetic energy and the polymer's elastic energy is also investigated to understand its physical mechanism. Supported by the Japan Society for the Promotion of Science research fellowship and the Ministry of Education, Culture, Sports, Science and Technology via `Energy Science in the Age of Global Warming' of Global Center of Excellence (G-COE) program (J-051).

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

    OpenAIRE

    SHIMAZU, Akihito; MATSUDAIRA, Ko; DE JONGE, Jan; TOSAKA, Naoya; WATANABE, Kazuhiro; TAKAHASHI, Masaya

    2016-01-01

    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 he...

  6. The double-edged sword of leader charisma: Understanding the curvilinear relationship between charismatic personality and leader effectiveness.

    Science.gov (United States)

    Vergauwe, Jasmine; Wille, Bart; Hofmans, Joeri; Kaiser, Robert B; De Fruyt, Filip

    2018-01-01

    This study advanced knowledge on charisma by (a) introducing a new personality-based model to conceptualize and assess charisma and by (b) investigating curvilinear relationships between charismatic personality and leader effectiveness. Moreover, we delved deeper into this curvilinear association by (c) examining moderation by the leader's level of adjustment and by (d) testing a process model through which the effects of charismatic personality on effectiveness are explained with a consideration of specific leader behaviors. Study 1 validated HDS charisma (Hogan Development Survey) as a useful trait-based measure of charisma. In Study 2 a sample of leaders (N = 306) were assessed in the context of a 360-degree development center. In line with the too-much-of-a-good-thing effect, an inverted U-shaped relationship between charismatic personality and observer-rated leader effectiveness was found, indicating that moderate levels are better than low or high levels of charisma. Study 3 (N = 287) replicated this curvilinear relationship and further illustrated the moderating role of leader adjustment, in such a way that the inflection point after which the effects of charisma turn negative occurs at higher levels of charisma when adjustment is high. Nonlinear mediation modeling further confirmed that strategic and operational leader behaviors fully mediate the curvilinear relationship. Leaders low on charisma are less effective because they lack strategic behavior; highly charismatic leaders are less effective because they lack operational behavior. In sum, this work provides insight into the dispositional nature of charisma and uncovers the processes through which and conditions under which leader charisma translates into (in)effectiveness. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  7. Curvilinear bodies are associated with adverse effects on muscle function but not with hydroxychloroquine dosing.

    Science.gov (United States)

    Khoo, Thomas; Otto, Sophia; Smith, Caroline; Koszyca, Barbara; Lester, Sue; Blumbergs, Peter; Limaye, Vidya

    2017-03-01

    The clinical significance of curvilinear bodies (CB) seen in association with hydroxychloroquine (HCQ) therapy is uncertain. Patients with CB on muscle biopsy performed between 2006 and the present were identified, and their clinical features including body mass index and cumulative HCQ dose were recorded. A control group of 16 patients with idiopathic inflammatory myositis (IIM) on HCQ at time of biopsy but without evidence of CB was identified. Nineteen patients with CB were identified; details were available for 18. Among patients with CB, 7/18 also had IIM. Seven out of ten patients with CB who did not have IIM or MHCI/II expression had proximal weakness; 7/11 had raised serum creatinine kinase (CK) levels. There was no difference in body weight (p = 0.47), body mass index (p = 0.93), cumulative HCQ dose (p = 0.52) or cumulative dose adjusted for body weight (p = 0.39) or body mass index (p = 0.32) between patients with CB and controls. Patients with CB had lower median CK levels than controls (p = 0.034). Weakness was present in 12/17 patients and 12/16 controls (p = 1.0). Concurrent proton-pump inhibitors were co-prescribed in 12/18 (67 %) patients with CB and in 6/16 (38 %) controls (p = 0.17). Development of CB does not appear to be related to cumulative HCQ dose or body weight. Patients with CB frequently have muscle weakness in the absence of MHC1 expression suggesting a role for non-immune mechanisms of muscle injury. A high proportion of patients with CB are co-prescribed proton-pump inhibitors raising the possibility that co-prescription of both agents may disrupt lysosomal function and adversely affect muscle function.

  8. The curvilinear effects of sexual orientation on young adult substance use.

    Science.gov (United States)

    Parnes, Jamie E; Rahm-Knigge, Ryan L; Conner, Bradley T

    2017-03-01

    Alcohol, tobacco, and marijuana are commonly used by adolescents and linked with harmful health-related outcomes (e.g. injury, dependence). Moreover, heavy episodic (binge) drinking predicts more severe consequences. When examined by sexual orientation, highest rates of substance use have been found among bisexual individuals, with lower use at either end of the spectrum. When examined also by sex, this curvilinear trend is maintained among women but not men. These substance use patterns were identified using group differences (i.e. heterosexual vs. bisexual vs. homosexual). However, evidence suggests that sexual orientation is a continuous, not categorical, variable. This study examined the hypotheses that sexual orientation and commonly used substances (heavy episodic drinking, tobacco, marijuana) would have a quadratic relation among women, but not among men. Six negative binomial regressions tested study hypotheses using data from 7372 participants. Results indicated that sexual orientation had a quadratic relation with heavy episodic drinking, tobacco use, and marijuana use among women, as hypothesized. Additionally, a quadratic relation was found between marijuana use and sexual orientation among men. These findings indicate that women identifying as having mixed sexual orientation are at higher risk than women at either end of the sexual orientation continuum for substance use and related negative outcomes. For men, this is only true for marijuana use and resultant negative consequences. This observed increased use may relate to coping with increased stressors, which has been linked to more problematic use. By better understanding LBG identities and behaviors, clinicians and researchers will be more adept at identifying risk factors and better understanding the nuances across the sexual orientation spectrum. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Curvilinear immersed boundary method for simulating fluid structure interaction with complex 3D rigid bodies

    Science.gov (United States)

    Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

    2008-08-01

    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 the FSI algorithm is unconditionally unstable 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

  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. Using the Theory of Combined Friction when Making Mathematical Models of Curvilinear Motion of Tracked Vehicles

    Directory of Open Access Journals (Sweden)

    M. V. Vyaznikov

    2014-01-01

    Full Text Available The paper presents study results of the nonlinear interaction processes between the supporting surface of the track Assembly and the ground in the contact patch, using the mathematical models of friction. For the case blaskapelle motion of a caterpillar, when the resultant of the elementary friction forces is limited by the coupling due to the sliding tracks on the ground, it appears that the increase of the lateral component leads to a decrease of the longitudinal component and the change of direction of the resulting force. As a result, with increasing angular velocity of the tracked vehicle a longitudinal component of the friction force decreases, which is the geometric factor and is defined by the locus of friction for a given type of soil. In the development of this well-known model is considered the general case of friction, which describes the effect of reducing the coefficient of friction in the contact patch at increasing the angular velocity of rotation. To describe this process is used the model of the combined friction which occurs when the surface of the body is doing at the same time the rotational and translational motion. The resulting expression for the resultant of forces of friction and the moment of resistance to rotation based on the decomposition of the first order Pade for a flat spot track Assembly with ground of rectangular shape. With combined friction any arbitrarily small perturbation force acting parallel to the surface of the contact spot, leads to slip. The paper considers the possibility of using the model of the combined friction to research a sustainability curvilinear motion of tracked vehicles. The proposed motion of the machine in the mode of skidding on the basis of the frictionslip. The interpretation of the physical processes occurring in the contact area, on the basis of the theory of the combined friction would allow using this mathematical model in the algorithm structure of automatic traffic control

  12. Combined orthognathic distraction procedure: Le Fort I maxillary osteotomy and mandibular curvilinear distraction osteogenesis. A new technique for craniofacial management.

    Science.gov (United States)

    Schendel, Stephen A; Hazan-Molina, Hagai; Aizenbud, Dror

    2014-04-01

    Dentofacial deformities are traditionally treated by maxillary and mandibular osteotomies conducted separately or simultaneously. Recently, distraction osteogenesis has become an irreplaceable part of the surgical armamentarium, for its ability to induce new bone formation between the surfaces of bone segments that are gradually separated by incremental traction, along with a simultaneous expansion of the surrounding soft-tissue envelope. The aim of this article is to describe a combined surgical technique consisting of simultaneous maxillary Le Fort I advancement and mandibular surgical repositioning by means of bilateral sagittal split osteotomy with a curvilinear distractor based on a preliminary computerized presurgical prediction.

  13. 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. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  14. 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.)

  15. 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

    International Nuclear Information System (INIS)

    Guermazi, Ali; Hayashi, Daichi; Hunter, David J.; Li, Ling; Benichou, Olivier; Eckstein, Felix; Kwoh, C.K.; Nevitt, Michael

    2012-01-01

    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.)

  16. 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.

  17. 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.

  18. Is the Relationship Between Pornography Consumption Frequency and Lower Sexual Satisfaction Curvilinear? Results From England and Germany.

    Science.gov (United States)

    Wright, Paul J; Steffen, Nicola J; Sun, Chyng

    2017-07-28

    Several studies using different methods have found that pornography consumption is associated with lower sexual satisfaction. The language used by media-effects scholars in discussions of this association implies an expectation that lowered satisfaction is primarily due to frequent-but not infrequent-consumption. Actual analyses, however, have assumed linearity. Linear analyses presuppose that for each increase in the frequency of pornography consumption there is a correspondingly equivalent decrease in sexual satisfaction. The present brief report explored the possibility that the association is curvilinear. Survey data from two studies of heterosexual adults, one conducted in England and the other in Germany, were employed. Results were parallel in each country and were not moderated by gender. Quadratic analysis indicated a curvilinear relationship, in the form of a predominantly negative, concave downward curve. Simple slope analyses suggested that when the frequency of consumption reaches once a month, sexual satisfaction begins to decrease, and that the magnitude of the decrease becomes larger with each increase in the frequency of consumption. The observational nature of the data employed precludes any causal inferences. However, if an effects perspective was adopted, these results would suggest that low rates of pornography consumption have no impact on sexual satisfaction and that adverse effects initiate only after consumption reaches a certain frequency.

  19. 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.

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

    KAUST Repository

    Yuan, Xuefei; Jardin, Stephen C.; Keyes, David E.

    2012-01-01

    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.

  1. Optimum stacking sequence design of laminated composite circular plates with curvilinear fibres by a layer-wise optimization method

    Science.gov (United States)

    Guenanou, A.; Houmat, A.

    2018-05-01

    The optimum stacking sequence design for the maximum fundamental frequency of symmetrically laminated composite circular plates with curvilinear fibres is investigated for the first time using a layer-wise optimization method. The design variables are two fibre orientation angles per layer. The fibre paths are constructed using the method of shifted paths. The first-order shear deformation plate theory and a curved square p-element are used to calculate the objective function. The blending function method is used to model accurately the geometry of the circular plate. The equations of motion are derived using Lagrange's method. The numerical results are validated by means of a convergence test and comparison with published values for symmetrically laminated composite circular plates with rectilinear fibres. The material parameters, boundary conditions, number of layers and thickness are shown to influence the optimum solutions to different extents. The results should serve as a benchmark for optimum stacking sequences of symmetrically laminated composite circular plates with curvilinear fibres.

  2. 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)

    1997-12-31

    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.

  3. 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.

  4. Scleral fixation of a subluxated intraocular lens-capsular bag complex through a fibrotic continuous curvilinear capsulorhexis.

    Science.gov (United States)

    Gimbel, Howard V; Brucks, Matthew; Dardzhikova, Albena A; Camoriano, Gerardo D

    2011-04-01

    Several strategies have been devised to manage in-the-bag intraocular lens (IOL) subluxation. We describe a method of fixating the IOL-capsular bag complex to the sclera using the fibrotic ring that develops around the continuous curvilinear capsulorhexis (CCC). Two, preferably 3, double-armed 10-0 polypropylene sutures are passed around the fibrotic CCC rim of the capsule and out the Hoffman scleral pockets and then tied in the scleral tunnels to center the IOL-bag complex. This technique provides an alternative approach to repositioning and fixating the IOL-bag complex that is especially useful in cases in which removal and replacement of the IOL would be difficult. It also provides more than 2-point fixation to achieve perfect IOL centration. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  5. 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.

  6. Investigation of nonlinear 2D bottom transportation dynamics in coastal zone on optimal curvilinear boundary adaptive grids

    Directory of Open Access Journals (Sweden)

    Sukhinov Alexander

    2017-01-01

    Full Text Available One of the practically important tasks of hydrophysics for sea coastal systems is the problem of modeling and forecasting bottom sediment transportation. A number of problems connected to ship safety traffic, water medium condition near the coastal line etc. depends on forecasting bottom deposit transportation under natural and technogenic influences. Coastal systems are characterized by a complicated form of coastline - the presence of long, narrow and curvilinear peninsulas and bays. Water currents and waves near the beach are strongly depend on complicated coastal line and in turn, exert on the bottom sediment transportation near the shore. The use of rectangular grids in the construction of discrete models leads to significant errors in both the specification of boundary conditions and in the modeling of hydrophysical processes in the coastal zone. In this paper, we consider the construction of a finite-element approximation of the initial-boundary value problem for the spatially two-dimensional linearized equation of sediment transportation using optimal boundary-adaptive grid. First, the linearization of a spatially two-dimensional nonlinear parabolic equation on the time grid is performed-when the coefficients of the equation that are nonlinearly dependent on the bottom relief function are set on the previous time layer, and the corresponding initial conditions are used on the first time layer. The algorithm for constructing the grid is based on the procedure for minimizing the generalized Dirichlet functional. On the constructed grid, finite element approximation using bilinear basis functions is performed, which completes the construction of a discrete model for the given problem. The using of curvilinear boundary adaptive grids leads to decreasing of total grid number in 5-20 times and respectively the total modeling time and/or it allows to improve modeling accuracy.

  7. Fovea sparing internal limiting membrane peeling using multiple parafoveal curvilinear peels for myopic foveoschisis: technique and outcome.

    Science.gov (United States)

    Jin, Haiying; Zhang, Qi; Zhao, Peiquan

    2016-10-18

    To introduce a modified surgical technique, the "parafoveal multiple curvelinear internal limiting membrane (ILM) peeling", to preserve epi-foveal ILM in myopic foveoschisis surgery. Consecutive patients with myopic foveoschisis were enrolled in the present prospective interventional case series. The surgeries were performed using transconjunctival 23-gauge system. The macular area was divided into quadrants. ILM was peeled off in a curvilinear manner centered around the site that was away from the central fovea in each quadrant. Shearing forces were used to control the direction to keep the peeling away from central fovea. ILM at central fovea of about 500 to 1000 μm was preserved by this technique. This technique was performed in 20 eyes of 20 consecutive patients. Epi-foveal ILM was successfully preserved in all cases using the technique. Patients were followed up for more than 12 months. The mean postoperative logMAR visual acuity improved from 1.67 ± 0.65 preoperatively to 1.15 ± 0.49 (P = 0.015; paired t-test). Postoperative OCT examinations showed that full-thickness macular holes (MHs) did not developed in any case. Central fovea thickness decreased from 910 ± 261 μm preoperatively to 125 ± 85 postoperatively (P = 0.001; paired t-test). Fovea sparing ILM peeling using multiple parafoveal curvilinear peels prevents the development of postoperative full-thickness MHs in eyes with myopic foveoschisis.

  8. Ocean Hydrodynamics Numerical Model in Curvilinear Coordinates for Simulating Circulation of the Global Ocean and its Separate Basins.

    Science.gov (United States)

    Gusev, Anatoly; Diansky, Nikolay; Zalesny, Vladimir

    2010-05-01

    The original program complex is proposed for the ocean circulation sigma-model, developed in the Institute of Numerical Mathematics (INM), Russian Academy of Sciences (RAS). The complex can be used in various curvilinear orthogonal coordinate systems. In addition to ocean circulation model, the complex contains a sea ice dynamics and thermodynamics model, as well as the original system of the atmospheric forcing implementation on the basis of both prescribed meteodata and atmospheric model results. This complex can be used as the oceanic block of Earth climate model as well as for solving the scientific and practical problems concerning the World ocean and its separate oceans and seas. The developed program complex can be effectively used on parallel shared memory computational systems and on contemporary personal computers. On the base of the complex proposed the ocean general circulation model (OGCM) was developed. The model is realized in the curvilinear orthogonal coordinate system obtained by the conformal transformation of the standard geographical grid that allowed us to locate the system singularities outside the integration domain. The horizontal resolution of the OGCM is 1 degree on longitude, 0.5 degree on latitude, and it has 40 non-uniform sigma-levels in depth. The model was integrated for 100 years starting from the Levitus January climatology using the realistic atmospheric annual cycle calculated on the base of CORE datasets. The experimental results showed us that the model adequately reproduces the basic characteristics of large-scale World Ocean dynamics, that is in good agreement with both observational data and results of the best climatic OGCMs. This OGCM is used as the oceanic component of the new version of climatic system model (CSM) developed in INM RAS. The latter is now ready for carrying out the new numerical experiments on climate and its change modelling according to IPCC (Intergovernmental Panel on Climate Change) scenarios in the

  9. 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

  10. A numerical method for transient gas-liquid two-phase flow using a general curvilinear coordinate system. 1. Governing equations and numerical method

    International Nuclear Information System (INIS)

    Tomiyama, Akio; Matsuoka, Toshiyuki.

    1995-01-01

    A simple numerical method for solving a transient incompressible two-fluid model was proposed in the present study. A general curvilinear coordinate system was adopted in this method for predicting transient flows in practical engineering devices. The simplicity of the present method is due to the fact that the field equations and constitutive equations were expressed in a tensor form in the general curvilinear coordinate system. When a conventional rectangular mesh is adopted in a calculation, the method reduces to a numerical method for a Cartesian coordinate system. As an example, the present method was applied to transient air-water bubbly flow in a vertical U-tube. It was confirmed that the effects of centrifugal and gravitational forces on the phase distribution in the U-tube were reasonably predicted. (author)

  11. A numerical method for the solution of three-dimensional incompressible viscous flow using the boundary-fitted curvilinear coordinate transformation and domain decomposition technique

    International Nuclear Information System (INIS)

    Umegaki, Kikuo; Miki, Kazuyoshi

    1990-01-01

    A numerical method is developed to solve three-dimensional incompressible viscous flow in complicated geometry using curvilinear coordinate transformation and domain decomposition technique. In this approach, a complicated flow domain is decomposed into several subdomains, each of which has an overlapping region with neighboring subdomains. Curvilinear coordinates are numerically generated in each subdomain using the boundary-fitted coordinate transformation technique. The modified SMAC scheme is developed to solve Navier-Stokes equations in which the convective terms are discretized by the QUICK method. A fully vectorized computer program is developed on the basis of the proposed method. The program is applied to flow analysis in a semicircular curved, 90deg elbow and T-shape branched pipes. Computational time with the vector processor of the HITAC S-810/20 supercomputer system, is reduced to 1/10∼1/20 of that with a scalar processor. (author)

  12. Analysis and modeling of dry matter production rate by soybean [Glycine max] community: Curvilinear response to radiation intensity

    International Nuclear Information System (INIS)

    Sameshima, R.

    1996-01-01

    The linear relationship between the amount of absorbed radiation and dry matter production by crop communities has long been known, and the proportionality constant between them is known as the radiation use efficiency (RUE). To analyze and predict crop production using RUE, the assumption is often made that RUE is not sensitive to radiation intensity and that dry matter production rate (DMPR) is a linear function of radiation intensity.However, there is evidence in opposition to this assumption, including reports of increasing RUE in shade tests, and hyperbolic response of photosynthetic rate to radiation intensity. The following model was developed and used to analyze the response of DMPR and RUE to daily radiation R S : DMPR = DMPR max (R S ) * g(α) where DMPR max (R S ) is the DMPR of a hypothetical soybean community absorbing all radiation, and g(α) represents the effect of radiation absorptivity (α). A hyperbolic curve and a straight line were employed for DMPR max (R S ) and g(α), respectively. Field experimental data including shade tests were used to determine the parameters for the model. Two sets of parameters were required to cover the entire experimental period. DMPR max (R S ) had an apparent curvilinear relationship with R S . The model successfully described dry matter production under successive low radiation conditions, which could not be estimated by a model with RUE insensitive to radiation. (author)

  13. Curvilinear immersed-boundary method for simulating unsteady flows in shallow natural streams with arbitrarily complex obstacles

    Science.gov (United States)

    Kang, Seokkoo; Borazjani, Iman; Sotiropoulos, Fotis

    2008-11-01

    Unsteady 3D simulations of flows in natural streams is a challenging task due to the complexity of the bathymetry, the shallowness of the flow, and the presence of multiple nature- and man-made obstacles. This work is motivated by the need to develop a powerful numerical method for simulating such flows using coherent-structure-resolving turbulence models. We employ the curvilinear immersed boundary method of Ge and Sotiropoulos (Journal of Computational Physics, 2007) and address the critical issue of numerical efficiency in large aspect ratio computational domains and grids such as those encountered in long and shallow open channels. We show that the matrix-free Newton-Krylov method for solving the momentum equations coupled with an algebraic multigrid method with incomplete LU preconditioner for solving the Poisson equation yield a robust and efficient procedure for obtaining time-accurate solutions in such problems. We demonstrate the potential of the numerical approach by carrying out a direct numerical simulation of flow in a long and shallow meandering stream with multiple hydraulic structures.

  14. Can super smart leaders suffer from too much of a good thing? The curvilinear effect of intelligence on perceived leadership behavior.

    Science.gov (United States)

    Antonakis, John; House, Robert J; Simonton, Dean Keith

    2017-07-01

    Although researchers predominately test for linear relationships between variables, at times there may be theoretical and even empirical reasons for expecting nonlinear functions. We examined if the relation between intelligence (IQ) and perceived leadership might be more accurately described by a curvilinear single-peaked function. Following Simonton's (1985) theory, we tested a specific model, indicating that the optimal IQ for perceived leadership will appear at about 1.2 standard deviations above the mean IQ of the group membership. The sample consisted of midlevel leaders from multinational private-sector companies. We used the leaders' scores on the Wonderlic Personnel Test (WPT)-a measure of IQ-to predict how they would be perceived on prototypically effective leadership (i.e., transformational and instrumental leadership). Accounting for the effects of leader personality, gender, age, as well as company, country, and time fixed effects, analyses indicated that perceptions of leadership followed a curvilinear inverted-U function of intelligence. The peak of this function was at an IQ score of about 120, which did not depart significantly from the value predicted by the theory. As the first direct empirical test of a precise curvilinear model of the intelligence-leadership relation, the results have important implications for future research on how leaders are perceived in the workplace. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Comparison of characteristics of femtosecond laser-assisted anterior capsulotomy versus manual continuous curvilinear capsulorrhexis: A meta-analysis of 5-year results.

    Science.gov (United States)

    Ali, Muhammad Hassaan; Ullah, Samee; Javaid, Usman; Javaid, Mamoona; Jamal, Samreen; Butt, Nadeem Hafeez

    2017-10-01

    To perform a meta-analysis on the precision and safety of femtosecond laser-assisted anterior capsulotomy versus conventional manual continuous curvilinear capsulorrhexis. This meta-analysis was conducted from February 2010 to November 2014. Literature search on PubMed, Google Scholar, ExcerptaMedica database and Cochrane Library was done to identify randomised controlled trials and case-control studies. SPSS 20 was used for data analysis. Of the 10 articles included, there were 3(30%) randomised controlled trials and 7(70%) non-randomised controlled trials. The meta-analysis was based on a total of 2,882eyes. Of them, 1,498(51.97%) underwent femtosecond laser-assisted capsulotomy and 1,384(48.02%) underwent manual continuous curvilinear capsulorrhexis. The diameter of the capsulotomy and the rates of anterior capsule tear showed no statistical difference between the femtosecond laser group and the manual capsulorrhexis group (p=0.29 and p=0.68). In terms of circularity of capsulotomy, femtosecond laser group had a more significant advantage than the manual capsulorrhexis group (pmanual continuous curvilinear capsulorrhexis.

  16. A rapid and low noise switch from RANS to WMLES on curvilinear grids with compressible flow solvers

    Science.gov (United States)

    Deck, Sébastien; Weiss, Pierre-Elie; Renard, Nicolas

    2018-06-01

    A turbulent inflow for a rapid and low noise switch from RANS to Wall-Modelled LES on curvilinear grids with compressible flow solvers is presented. It can be embedded within the computational domain in practical applications with WMLES grids around three-dimensional geometries in a flexible zonal hybrid RANS/LES modelling context. It relies on a physics-motivated combination of Zonal Detached Eddy Simulation (ZDES) as the WMLES technique together with a Dynamic Forcing method processing the fluctuations caused by a Zonal Immersed Boundary Condition describing roughness elements. The performance in generating a physically-sound turbulent flow field with the proper mean skin friction and turbulent profiles after a short relaxation length is equivalent to more common inflow methods thanks to the generation of large-scale streamwise vorticity by the roughness elements. Comparisons in a low Mach-number zero-pressure-gradient flat-plate turbulent boundary layer up to Reθ = 6 100 reveal that the pressure field is dominated by the spurious noise caused by the synthetic turbulence methods (Synthetic Eddy Method and White Noise injection), contrary to the new low-noise approach which may be used to obtain the low-frequency component of wall pressure and reproduce its intermittent nature. The robustness of the method is tested in the flow around a three-element airfoil with WMLES in the upper boundary layer near the trailing edge of the main element. In spite of the very short relaxation distance allowed, self-sustainable resolved turbulence is generated in the outer layer with significantly less spurious noise than with the approach involving White Noise. The ZDES grid count for this latter test case is more than two orders of magnitude lower than the Wall-Resolved LES requirement and a unique mesh is involved, which is much simpler than some multiple-mesh strategies devised for WMLES or turbulent inflow.

  17. Appraisal and standardization of curvilinear velocity (VCL) cut-off values for CASA analysis of Japanese quail (Coturnix japonica) sperm.

    Science.gov (United States)

    Farooq, U; Malecki, I A; Mahmood, M; Martin, G B

    2017-06-01

    One of the basic steps in objective analysis of sperm motility is the subdivision of a motile sperm population into slow, medium and rapid categories based on their velocity. However, for CASA analysis of quail sperm, the velocity values for categorization of slow, medium and rapid sperm have not yet been standardized. To identify the cut-off values of "velocity curvilinear" (VCL) for quail sperm categorization, we captured and analysed 22,300 tracks of quail sperm using SCA ® -CASA. The median and mean VCL values were 85 and 97 μm/s. To define the VCL cut-off values, we used two methods. In the first, we identified the upper (rapid sperm) and lower (slow sperm) cut-off values using: (i) median VCL ± 25% or ± 50% or ± 75% of median VCL value; (ii) first and third quartile values of VCL data (i.e. 25% cut-off setting); and (iii) 33% and 66% of VCL data. Among these settings, sperm categories and their corresponding motility characteristics recorded using the "25%" setting (i.e. slow ≤36 ≤ medium ≤154 ≤ rapid) were found the most realistic and coherent with male ranking by fertility. In the second method, we calculated heteroscedasticity in the total VCL data using PCA and the two-step clustering method. With this approach, the mean of the high and low clusters was 165 and 51 μm/s, respectively. Together, the mean from two methods suggested that, for SCA ® -CASA categorization of quail sperm, sperm should be classed as "rapid" at VCL ≥160 μm/s and "slow" at VCL ≤45 μm/s. © 2017 Blackwell Verlag GmbH.

  18. Curvilinear crack layer propagation

    Science.gov (United States)

    Chudnovsky, Alexander; Chaoui, Kamel; Moet, Abdelsamie

    1987-01-01

    An account is given of an experiment designed to allow observation of the effect of damage orientation on the direction of crack growth in the case of crack layer propagation, using polystyrene as the model material. The direction of crack advance under a given loading condition is noted to be determined by a competition between the tendency of the crack to maintain its current direction and the tendency to follow the orientation of the crazes at its tip. The orientation of the crazes is, on the other hand, determined by the stress field due to the interaction of the crack, the crazes, and the hole. The changes in craze rotation relative to the crack define the active zone rotation.

  19. Vorticity vector-potential method based on time-dependent curvilinear coordinates for two-dimensional rotating flows in closed configurations

    Science.gov (United States)

    Fu, Yuan; Zhang, Da-peng; Xie, Xi-lin

    2018-04-01

    In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial and non-inertial frames of reference with the advantage of a fixed and regular calculation domain. The numerical method is applied to triangle and curved triangle configurations in constant and varying rotational angular velocity cases respectively. The evolutions of flow field are studied. The geostrophic effect, unsteady effect and curvature effect on the evolutions are discussed.

  20. 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. Copyright © 2012 Wiley Periodicals, Inc.

  1. Does Early Environmental Complexity Influence Tyrosine Hydroxylase in the Chicken Hippocampus and "Prefrontal" Caudolateral Nidopallium?

    NARCIS (Netherlands)

    Tahamtani, Fernanda M; Nordgreen, Janicke; Brantsæter, Margrethe; Østby, Gunn C; Nordquist, Rebecca E; Janczak, Andrew M

    2016-01-01

    In adult chickens, the housing system influences hippocampal morphology and neurochemistry. However, no work has been done investigating the effects of the early life environment on chicken brain development. In the present study, we reared 67 commercial laying hens (Gallus gallus domesticus) in two

  2. The computation of turbulent recirculating flow using curvilinear finite differences. Application of the k - epsilon model to the flow in dredged trenches

    International Nuclear Information System (INIS)

    Alfrink, B.J.

    1981-08-01

    The report treats the computation of turbulent recirculating flow in dredged trenches. The mathematical model consists of the full two-dimensional unsteady Reynolds equations, formulated in primitive variables. Turbulence closure is obtained by means of a two-equation (k - epsilon) model. The numerical technique is based on the use of curvilinear finite differences in space and of fractional steps in time. A procedure is proposed to apply the model for varying roughness circumstances. The value of the Von Karman constant can be determined from geometric information. Afterwards, only the c 1 -constant is adapted by means of a degenerated epsilon-equation. The report describes an extensive sensitivity study for the inlet conditions and the empirical constants. Ultimately, the results of the mathematical model are very satisfactory. Compared with laboratory experiments, the recirculation length is only underpredicted with 10%

  3. 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

    2015-01-01

    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. PMID:27347448

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

    Science.gov (United States)

    Asgharzadeh, Hafez; Borazjani, Iman

    2014-11-01

    Time step-size restrictions and low convergence rates are major bottle necks for implicit solution of the Navier-Stokes in simulations involving complex geometries with moving boundaries. Newton-Krylov method (NKM) is a combination of a Newton-type method for super-linearly convergent solution of nonlinear equations and Krylov subspace methods for solving the Newton correction equations, which can theoretically address both bottle necks. The efficiency of this method vastly depends on the Jacobian forming scheme e.g. automatic differentiation is very expensive and Jacobian-free methods slow down as the mesh is refined. A novel, computationally efficient analytical Jacobian for NKM was developed to solve unsteady incompressible Navier-Stokes momentum equations on staggered curvilinear grids with immersed boundaries. The NKM was validated and verified against Taylor-Green vortex and pulsatile flow in a 90 degree bend and efficiently handles complex geometries such as an intracranial aneurysm with multiple overset grids, pulsatile inlet flow and immersed boundaries. The NKM method is shown to be more efficient than the semi-implicit Runge-Kutta methods and Jabobian-free Newton-Krylov methods. We believe NKM can be applied to many CFD techniques to decrease the computational cost. This work was supported partly by the NIH Grant R03EB014860, and the computational resources were partly provided by Center for Computational Research (CCR) at University at Buffalo.

  5. Continuous Curvilinear Capsulorhexis Training and Non-Rhexis Related Vitreous Loss: The Specificity of Virtual Reality Simulator Surgical Training (An American Ophthalmological Society Thesis).

    Science.gov (United States)

    McCannel, Colin A

    2017-08-01

    To assess the specificity of simulation-based virtual reality ophthalmic cataract surgery training on the Eyesi ophthalmic virtual reality surgical simulator, and test the hypothesis that microsurgical motor learning is highly specific. Retrospective educational interventional case series. The rates of vitreous loss and retained lens material, and vitreous loss and retained lens material associated with an errant continuous curvilinear capsulorhexis (CCC) were assessed among 1037 consecutive cataract surgeries performed during four consecutive academic years at a teaching hospital. The data were grouped by Eyesi use and capsulorhexis intensive training curriculum (CITC) completion. The main intervention was the completion of the CITC on the Eyesi. In the Eyesi simulator experience-based stratification, the vitreous loss rate was similar in each group (chi square p=0.95) and was not preceded by an errant CCC in 86.2% for "CITC done at least once", 57.1% for "CITC not done, but some Eyesi use", and 48.9% for "none" training groups (p=4×10-5). Retained lens material overall and occurring among the errant CCC cases was similar among training groups (p=0.82 and p=0.71, respectively). Eyesi capsulorhexis training was not associated with lower vitreous loss rates overall. However, non-errant CCC associated vitreous loss was higher among those who underwent Eyesi capsulorhexis training. Training focused on the CCC portion of cataract surgery may not reduce vitreous loss unassociated with an errant CCC. It is likely that surgical training is highly specific to the task being trained. Residents may need to be trained for all surgical steps with adequate intensity to minimize overall complication rates.

  6. 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

    2017-02-15

    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 nonlinear 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 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

  7. 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

    2016-01-01

    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 nonlinear 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 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

  8. Cervical osteophytes presenting as unilateral vocal fold paralysis and dysphagia.

    Science.gov (United States)

    Yoskovitch, A; Kantor, S

    2001-05-01

    Any process involving either the vagus nerve, its recurrent laryngeal branch or the external branch of the superior laryngeal nerve may cause paralysis of the vocal fold. The most common cause is neoplasm. Clinically, the patients often present with a hoarse, breathy voice as well as symptoms of aspiration. The following represents a unique case of unilateral vocal fold paralysis and dysphagia caused by a degenerative disease of the cervical spine, resluting in extrinsic compression of the recurrent laryngeal nerve.

  9. Autofocus algorithm for curvilinear SAR imaging

    Science.gov (United States)

    Bleszynski, E.; Bleszynski, M.; Jaroszewicz, T.

    2012-05-01

    We describe an approach to autofocusing for large apertures on curved SAR trajectories. It is a phase-gradient type method in which phase corrections compensating trajectory perturbations are estimated not directly from the image itself, but rather on the basis of partial" SAR data { functions of the slow and fast times { recon- structed (by an appropriate forward-projection procedure) from windowed scene patches, of sizes comparable to distances between distinct targets or localized features of the scene. The resulting partial data" can be shown to contain the same information on the phase perturbations as that in the original data, provided the frequencies of the perturbations do not exceed a quantity proportional to the patch size. The algorithm uses as input a sequence of conventional scene images based on moderate-size subapertures constituting the full aperture for which the phase corrections are to be determined. The subaperture images are formed with pixel sizes comparable to the range resolution which, for the optimal subaperture size, should be also approximately equal the cross-range resolution. The method does not restrict the size or shape of the synthetic aperture and can be incorporated in the data collection process in persistent sensing scenarios. The algorithm has been tested on the publicly available set of GOTCHA data, intentionally corrupted by random-walk-type trajectory uctuations (a possible model of errors caused by imprecise inertial navigation system readings) of maximum frequencies compatible with the selected patch size. It was able to eciently remove image corruption for apertures of sizes up to 360 degrees.

  10. Particle simulation in curvilinear coordinate systems

    International Nuclear Information System (INIS)

    LeBrun, M.J.; Tajima, T.

    1989-01-01

    We present methods for particle simulation of plasmas in a nearly arbitrary coordinate metric and describe a toroidal electrostatic simulation code that evolved from this effort. A Mercier-type coordinate system is used, with a nonuniform radial grid for improved cross-field resolution. A fast iterative method for solving the Poisson equation is employed, and the interpolation/filtering technique shown to be momentum and energy conserving in the continuum limit. Lorentz ion and drift electron species are used. The code has been thoroughly tested for its reproduction of linear and nonlinear physics, and has been applied to the toroidal drift wave problem and its impact on anomalous transport in tokamaks. 40 refs., 10 figs., 1 tab

  11. The Relationship Between Academic Supervisor Leadership and Creativity of Postgraduates:Linear or Curvilinear?%学术导师领导力与研究生创造力:直线相关还是曲线相关?

    Institute of Scientific and Technical Information of China (English)

    蒙艺; 罗长坤

    2015-01-01

    学术导师领导力是影响研究生创造力的一个重要因素。基于相关理论,提出和回答关于学术导师领导力与研究生创造力关系状态的研究问题。曲线拟合和等级回归分析677个样本数据的结果显示:学术导师领导力与创造力曲线相关,是正U型曲线关系。研究发现弥补相关理论的缺失,为学术导师领导实践和高等院校创新教育管理提供切实的参考。%Academic supervisor leadership is one of the significant factors influencing creativity of postgraduates. Based on the related theories, the research reported in this paper raises and probes into the question on the relationship between academic supervisor leadership and creativity of postgraduates. The study employs curve estimation and hierarchical regression to analyze data collected from 677 postgraduates. The results demonstrate a curvilinear (U-shaped) relationship between academic supervisor leadership and creativity of postgraduates. The findings fill the research gaps of related theories, and provide a valuable reference for leadership practice of academic supervisors and creativity management of high education.

  12. Vibrational self-consistent field theory using optimized curvilinear coordinates.

    Science.gov (United States)

    Bulik, Ireneusz W; Frisch, Michael J; Vaccaro, Patrick H

    2017-07-28

    A vibrational SCF model is presented in which the functions forming the single-mode functions in the product wavefunction are expressed in terms of internal coordinates and the coordinates used for each mode are optimized variationally. This model involves no approximations to the kinetic energy operator and does not require a Taylor-series expansion of the potential. The non-linear optimization of coordinates is found to give much better product wavefunctions than the limited variations considered in most previous applications of SCF methods to vibrational problems. The approach is tested using published potential energy surfaces for water, ammonia, and formaldehyde. Variational flexibility allowed in the current ansätze results in excellent zero-point energies expressed through single-product states and accurate fundamental transition frequencies realized by short configuration-interaction expansions. Fully variational optimization of single-product states for excited vibrational levels also is discussed. The highlighted methodology constitutes an excellent starting point for more sophisticated treatments, as the bulk characteristics of many-mode coupling are accounted for efficiently in terms of compact wavefunctions (as evident from the accurate prediction of transition frequencies).

  13. Angular parallelization of a curvilinear Sn transport theory method

    International Nuclear Information System (INIS)

    Haghighat, A.

    1991-01-01

    In this paper a parallel algorithm for angular domain decomposition (or parallelization) of an r-dependent spherical S n transport theory method is derived. The parallel formulation is incorporated into TWOTRAN-II using the IBM Parallel Fortran compiler and implemented on an IBM 3090/400 (with four processors). The behavior of the parallel algorithm for different physical problems is studied, and it is concluded that the parallel algorithm behaves differently in the presence of a fission source as opposed to the absence of a fission source; this is attributed to the relative contributions of the source and the angular redistribution terms in the S s algorithm. Further, the parallel performance of the algorithm is measured for various problem sizes and different combinations of angular subdomains or processors. Poor parallel efficiencies between ∼35 and 50% are achieved in situations where the relative difference of parallel to serial iterations is ∼50%. High parallel efficiencies between ∼60% and 90% are obtained in situations where the relative difference of parallel to serial iterations is <35%

  14. 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

    -16 years after surgery) 34 of these subjects (76%) were evaluated by weight-bearing knee radiography, and tibiofemoral joint changes were graded according to the Osteoarthritis Research Society International Atlas. RESULTS: Lower T1Gd in the medial compartment was associated with higher grade of medial JSN...

  15. Application of the three-dimensional aperiodic Fourier modal method using arc elements in curvilinear coordinates.

    Science.gov (United States)

    Bucci, Davide; Martin, Bruno; Morand, Alain

    2012-03-01

    This paper deals with a full vectorial generalization of the aperiodic Fourier modal method (AFMM) in cylindrical coordinates. The goal is to predict some key characteristics such as the bending losses of waveguides having an arbitrary distribution of the transverse refractive index. After a description of the method, we compare the results of the cylindrical coordinates AFMM with simulations by the finite-difference time-domain (FDTD) method performed on an S-bend structure made by a 500 nm × 200 nm silicon core (n=3.48) in silica (n=1.44) at a wavelength λ=1550 nm, the bending radius varying from 0.5 up to 2 μm. The FDTD and AFMM results show differences comparable to the variations obtained by changing the parameters of the FDTD simulations.

  16. 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.

  17. Curvilinear Moderation—A More Complete Examination of Moderation Effects in Behavioral Sciences

    OpenAIRE

    Johnson Ching-Hong Li

    2018-01-01

    In behavioral sciences, researchers often examine whether any linear moderations exist in their studies. That is, they evaluate the extent (i.e., magnitude, direction) to which a linear effect of a predictor X (e.g., cognitive ability) on a criterion Y (e.g., performance) may differ across the levels of a moderator M (e.g., gender). In that case, researchers often run a liner regression analysis for examining this moderation (e.g., gender by ability). Despite its popularity, linear moderation...

  18. A multi-dimensional Smolyak collocation method in curvilinear coordinates for computing vibrational spectra

    International Nuclear Information System (INIS)

    Avila, Gustavo; Carrington, Tucker

    2015-01-01

    In this paper, we improve the collocation method for computing vibrational spectra that was presented in Avila and Carrington, Jr. [J. Chem. Phys. 139, 134114 (2013)]. Using an iterative eigensolver, energy levels and wavefunctions are determined from values of the potential on a Smolyak grid. The kinetic energy matrix-vector product is evaluated by transforming a vector labelled with (nondirect product) grid indices to a vector labelled by (nondirect product) basis indices. Both the transformation and application of the kinetic energy operator (KEO) scale favorably. Collocation facilitates dealing with complicated KEOs because it obviates the need to calculate integrals of coordinate dependent coefficients of differential operators. The ideas are tested by computing energy levels of HONO using a KEO in bond coordinates

  19. 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.

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

    KAUST Repository

    Cannistraci, Carlo; Alanis Lobato, Gregorio; Ravasi, Timothy

    2013-01-01

    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

  1. The Curvilinear Relationship between Age and Emotional Aperture: The Moderating Role of Agreeableness

    OpenAIRE

    Faber, Anna; Walter, Frank

    2017-01-01

    The capability to correctly recognize collective emotion expressions [i.e., emotional aperture (EA)] is crucial for effective social and work-related interactions. Yet, little remains known about the antecedents of this ability. The present study therefore aims to shed new light onto key aspects that may promote or diminish an individual’s EA. We examine the role of age for this ability in an online sample of 181 participants (with an age range of 18–72 years, located in Germany), and we inve...

  2. Autofocus algorithm for synthetic aperture radar imaging with large curvilinear apertures

    Science.gov (United States)

    Bleszynski, E.; Bleszynski, M.; Jaroszewicz, T.

    2013-05-01

    An approach to autofocusing for large curved synthetic aperture radar (SAR) apertures is presented. Its essential feature is that phase corrections are being extracted not directly from SAR images, but rather from reconstructed SAR phase-history data representing windowed patches of the scene, of sizes sufficiently small to allow the linearization of the forward- and back-projection formulae. The algorithm processes data associated with each patch independently and in two steps. The first step employs a phase-gradient-type method in which phase correction compensating (possibly rapid) trajectory perturbations are estimated from the reconstructed phase history for the dominant scattering point on the patch. The second step uses phase-gradient-corrected data and extracts the absolute phase value, removing in this way phase ambiguities and reducing possible imperfections of the first stage, and providing the distances between the sensor and the scattering point with accuracy comparable to the wavelength. The features of the proposed autofocusing method are illustrated in its applications to intentionally corrupted small-scene 2006 Gotcha data. The examples include the extraction of absolute phases (ranges) for selected prominent point targets. They are then used to focus the scene and determine relative target-target distances.

  3. Small Modifications of Curvilinear Coordinates and Successive Approximations Applied in Geopotential Determination

    Science.gov (United States)

    Holota, P.; Nesvadba, O.

    2016-12-01

    The mathematical apparatus currently applied for geopotential determination is undoubtedly quite developed. This concerns numerical methods as well as methods based on classical analysis, equally as classical and weak solution concepts. Nevertheless, the nature of the real surface of the Earth has its specific features and is still rather complex. The aim of this paper is to consider these limits and to seek a balance between the performance of an apparatus developed for the surface of the Earth smoothed (or simplified) up to a certain degree and an iteration procedure used to bridge the difference between the real and smoothed topography. The approach is applied for the solution of the linear gravimetric boundary value problem in geopotential determination. Similarly as in other branches of engineering and mathematical physics a transformation of coordinates is used that offers a possibility to solve an alternative between the boundary complexity and the complexity of the coefficients of the partial differential equation governing the solution. As examples the use of modified spherical and also modified ellipsoidal coordinates for the transformation of the solution domain is discussed. However, the complexity of the boundary is then reflected in the structure of Laplace's operator. This effect is taken into account by means of successive approximations. The structure of the respective iteration steps is derived and analyzed. On the level of individual iteration steps the attention is paid to the representation of the solution in terms of function bases or in terms of Green's functions. The convergence of the procedure and the efficiency of its use for geopotential determination is discussed.

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

    KAUST Repository

    Cannistraci, Carlo; Ravasi, Timothy; Montevecchi, Franco Maria; Ideker, Trey; Alessio, Massimo

    2010-01-01

    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

  5. Tipping Points? Curvilinear Associations between Activity Level and Mental Development in Toddlers

    Science.gov (United States)

    Flom, Megan; Cohen, Madeleine; Saudino, Kimberly J.

    2017-01-01

    The Theory of Optimal Stimulation (Zentall & Zentall, "Psychological Bulletin," 94, 1983, 446) posits that the relation between activity level (AL) and cognitive performance follows an inverted U shape where midrange AL predicts better cognitive performance than AL at the extremes. We explored this by fitting linear and quadratic…

  6. 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

    which implies a very modest memory requirement. Nevertheless, the hierarchical feature of the basis functions maintains the ability to treat small geometrical details efficiently. In addition, the scatterer is modelled with higher-order curved patches which allows accurate modelling of curved surfaces...

  7. Ethnic Identity and Psychological Well-Being of International Transracial Adoptees: A Curvilinear Relationship

    Science.gov (United States)

    Mohanty, Jayashree

    2015-01-01

    Research in general has shown a beneficial effect of ethnic identity on adoptees' psychological well-being. However, studies also indicate that overemphasis on birth culture and racial/ethnic differences may negatively impact adoptees' overall adjustment. Using Rojewski's (2005) and Brodzinsky's (1987) propositions of a balanced approach to…

  8. Numerical generation of boundary-fitted curvilinear coordinate systems for arbitrarily curved surfaces

    International Nuclear Information System (INIS)

    Takagi, T.; Miki, K.; Chen, B.C.J.; Sha, W.T.

    1985-01-01

    A new method is presented for numerically generating boundary-fitted coordinate systems for arbitrarily curved surfaces. The three-dimensional surface has been expressed by functions of two parameters using the geometrical modeling techniques in computer graphics. This leads to new quasi-one- and two-dimensional elliptic partial differential equations for coordinate transformation. Since the equations involve the derivatives of the surface expressions, the grids geneated by the equations distribute on the surface depending on its slope and curvature. A computer program GRID-CS based on the method was developed and applied to a surface of the second order, a torus and a surface of a primary containment vessel for a nuclear reactor. These applications confirm that GRID-CS is a convenient and efficient tool for grid generation on arbitrarily curved surfaces

  9. Ablation of Perlecan Domain 1 Heparan Sulfate Reduces Progressive Cartilage Degradation, Synovitis, and Osteophyte Size in a Preclinical Model of Posttraumatic Osteoarthritis.

    Science.gov (United States)

    Shu, Cindy C; Jackson, Miriam T; Smith, Margaret M; Smith, Susan M; Penm, Steven; Lord, Megan S; Whitelock, John M; Little, Christopher B; Melrose, James

    2016-04-01

    To investigate the role of the heparan sulfate (HS) proteoglycan perlecan (HSPG-2) in regulating fibroblast growth factor (FGF) activity, bone and joint growth, and the onset and progression of posttraumatic osteoarthritis (OA) in a mouse gene-knockout model. Maturational changes were evaluated histologically in the knees of 3-, 6-, and 12-week-old wild-type (WT) mice and Hspg2(Δ3-/Δ3-) mice (Hspg2 lacking domain 1 HS, generated by ablation of exon 3 of perlecan). Cartilage damage, subchondral bone sclerosis, osteophytosis, and synovial inflammation were scored at 4 and 8 weeks after surgical induction of OA in WT and Hspg2(Δ3-/Δ3-) mice. Changes in cartilage expression of FGF-2, FGF-18, HSPG-2, FGF receptor 1 (FGFR-1), and FGFR-3 were examined immunohistochemically. Femoral head cartilage from both mouse genotypes was cultured in the presence or absence of interleukin-1α (IL-1α), FGF-2, and FGF-18, and the content and release of glycosaminoglycan (GAG) and expression of messenger RNA (mRNA) for key matrix molecules, enzymes, and inhibitors were quantified. No effect of perlecan HS ablation on growth plate or joint development was detected. After induction of OA, Hspg2(Δ3-/Δ3-) mice had significantly reduced cartilage erosion, osteophytosis, and synovitis. OA-induced loss of chondrocyte expression of FGF-2, FGF-18, and HSPG-2 occurred in both genotypes. Expression of FGFR-1 after OA induction was maintained in WT mice, while FGFR-3 loss after OA induction was significantly reduced in Hspg2(Δ3-/Δ3-) mice. There were no genotypic differences in GAG content or release between unstimulated control cartilage and IL-1α-stimulated cartilage. However, IL-1α-induced cartilage expression of Mmp3 mRNA was significantly reduced in Hspg2(Δ3-/Δ3-) mice. Cartilage GAG release in either the presence or absence of IL-1α was unaltered by FGF-2 in both genotypes. In cartilage cultures with FGF-18, IL-1α-stimulated GAG loss was significantly reduced only in Hspg2(Δ3-/Δ3-) mice, and this was associated with maintained expression of Fgfr3 mRNA and reduced expression of Mmp2/Mmp3 mRNA. Perlecan HS has significant roles in directing the development of posttraumatic OA, potentially via the alteration of FGF/HS/FGFR signaling. These data suggest that the chondroprotection conferred by perlecan HS ablation could be attributed, at least in part, to the preservation of FGFR-3 and increased FGF signaling. © 2016, American College of Rheumatology.

  10. 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

  11. 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…

  12. 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...... of this study demonstrate that the proposed beamforming approach is accurate for achieving correct time-of-flight calculations, and hence avoids geometrical distortions....

  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

  14. 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…

  15. 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%.

  16. The curvilinear relationship of early-life adversity and successful aging: the mediating role of mental health.

    Science.gov (United States)

    Höltge, Jan; Mc Gee, Shauna L; Thoma, Myriam V

    2018-02-15

    The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health. Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (M age = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted. Significant inverse U-shaped associations were found between ELA and iQoL (β = -.59, p = .005) and between ELA and mental health (β = -.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = -.84, BCa CI [-1.66, -.27]). Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.

  17. What Inverted U Can Do for Your Country: A Curvilinear Relationship Between Confidence in the Social System and Political Engagement.

    Science.gov (United States)

    Cichocka, Aleksandra; Górska, Paulina; Jost, John T; Sutton, Robbie M; Bilewicz, Michał

    2017-08-24

    We examined the link between political engagement and the tendency to justify the sociopolitical system. On one hand, confidence in the system should be negatively related to political engagement, insofar as it entails reduced desire for social change; on the other hand, system confidence should also be positively related to political engagement to the extent that it carries an assumption that the system is responsive to citizens' political efforts. Because of the combination of these 2 opposing forces, the motivation for political engagement should be highest at intermediate levels of system confidence. Five studies revealed a negative quadratic relationship between system confidence and normative political engagement. In 2 representative surveys, Polish participants with moderate levels of system confidence were more likely to vote in political elections (Study 1) and to participate in solidarity-based collective action (Study 2). Two field studies demonstrated a negative quadratic relationship between system confidence and actual participation in political demonstrations (gender equality and teachers' protests in Poland; Studies 3 and 4). This pattern of results was further corroborated by analyses of data from 50 countries drawn from the World Value Survey: we observed negative quadratic relationships between system confidence and collective action as well as voting. These relationships were stronger in democratic (vs. nondemocratic) regimes (Study 5). Our results suggest that some degree of system confidence might be useful to stimulate political engagement within the norms of the system. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. An entropy stable nodal discontinuous Galerkin method for the two dimensional shallow water equations on unstructured curvilinear meshes with discontinuous bathymetry

    Energy Technology Data Exchange (ETDEWEB)

    Wintermeyer, Niklas [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Winters, Andrew R., E-mail: awinters@math.uni-koeln.de [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Gassner, Gregor J. [Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln (Germany); Kopriva, David A. [Department of Mathematics, The Florida State University, Tallahassee, FL 32306 (United States)

    2017-07-01

    We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving scheme we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.

  19. Application of the Fourier pseudo spectral time-domain method in orthogonal curvilinear coordinates for near-rigid moderately curved surfaces

    NARCIS (Netherlands)

    Hornikx, M.C.J.; Dragna, D.

    2015-01-01

    The Fourier pseudospectral time-domain method is an efficient wave-based method to model sound propagation in inhomogeneous media. One of the limitations of the method for atmospheric sound propagation purposes is its restriction to a Cartesian grid, confining it to staircase-like geometries. A

  20. 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.

  1. The More, the Better? Curvilinear Effects of Job Autonomy on Well-Being From Vitamin Model and PE-Fit Theory Perspectives.

    Science.gov (United States)

    Stiglbauer, Barbara; Kovacs, Carrie

    2017-12-28

    In organizational psychology research, autonomy is generally seen as a job resource with a monotone positive relationship with desired occupational outcomes such as well-being. However, both Warr's vitamin model and person-environment (PE) fit theory suggest that negative outcomes may result from excesses of some job resources, including autonomy. Thus, the current studies used survey methodology to explore cross-sectional relationships between environmental autonomy, person-environment autonomy (mis)fit, and well-being. We found that autonomy and autonomy (mis)fit explained between 6% and 22% of variance in well-being, depending on type of autonomy (scheduling, method, or decision-making) and type of (mis)fit operationalization (atomistic operationalization through the separate assessment of actual and ideal autonomy levels vs. molecular operationalization through the direct assessment of perceived autonomy (mis)fit). Autonomy (mis)fit (PE-fit perspective) explained more unique variance in well-being than environmental autonomy itself (vitamin model perspective). Detrimental effects of autonomy excess on well-being were most evident for method autonomy and least consistent for decision-making autonomy. We argue that too-much-of-a-good-thing effects of job autonomy on well-being exist, but suggest that these may be dependent upon sample characteristics (range of autonomy levels), type of operationalization (molecular vs. atomistic fit), autonomy facet (method, scheduling, or decision-making), as well as individual and organizational moderators. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Comment on: Path integral solution of the Schroedinger equation in curvilinear coordinates: A straightforward procedure [J. Math. Phys. 37, 4310 endash 4319 (1996)

    International Nuclear Information System (INIS)

    Wurm, A.; LaChapelle, J.

    1997-01-01

    The authors comment on the paper by J. LaChapelle, J. Math. Phys. 37, 4310 (1996), and give explicit expressions for the parametrization, its solution, and the Lie derivatives of the Schroedinger equation for the case of n-dimensional spherical coordinates

  3. Adaptive FSI of flexible parachutes under strong dynamic loading using strongly coupled shell mechanics and large-eddy simulation with analytical curvilinear hybrid meshing

    Data.gov (United States)

    National Aeronautics and Space Administration — Future robotic and human space missions to planets and moons in the solar system will involve entry vehicles with higher masses than that of any currently available...

  4. INS3D - NUMERICAL SOLUTION OF THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS IN THREE-DIMENSIONAL GENERALIZED CURVILINEAR COORDINATES (DEC RISC ULTRIX VERSION)

    Science.gov (United States)

    Biyabani, S. R.

    1994-01-01

    INS3D computes steady-state solutions to the incompressible Navier-Stokes equations. The INS3D approach utilizes pseudo-compressibility combined with an approximate factorization scheme. This computational fluid dynamics (CFD) code has been verified on problems such as flow through a channel, flow over a backwardfacing step and flow over a circular cylinder. Three dimensional cases include flow over an ogive cylinder, flow through a rectangular duct, wind tunnel inlet flow, cylinder-wall juncture flow and flow through multiple posts mounted between two plates. INS3D uses a pseudo-compressibility approach in which a time derivative of pressure is added to the continuity equation, which together with the momentum equations form a set of four equations with pressure and velocity as the dependent variables. The equations' coordinates are transformed for general three dimensional applications. The equations are advanced in time by the implicit, non-iterative, approximately-factored, finite-difference scheme of Beam and Warming. The numerical stability of the scheme depends on the use of higher-order smoothing terms to damp out higher-frequency oscillations caused by second-order central differencing. The artificial compressibility introduces pressure (sound) waves of finite speed (whereas the speed of sound would be infinite in an incompressible fluid). As the solution converges, these pressure waves die out, causing the derivation of pressure with respect to time to approach zero. Thus, continuity is satisfied for the incompressible fluid in the steady state. Computational efficiency is achieved using a diagonal algorithm. A block tri-diagonal option is also available. When a steady-state solution is reached, the modified continuity equation will satisfy the divergence-free velocity field condition. INS3D is capable of handling several different types of boundaries encountered in numerical simulations, including solid-surface, inflow and outflow, and far-field boundaries. Three machine versions of INS3D are available. INS3D for the CRAY is written in CRAY FORTRAN for execution on a CRAY X-MP under COS, INS3D for the IBM is written in FORTRAN 77 for execution on an IBM 3090 under the VM or MVS operating system, and INS3D for DEC RISC-based systems is written in RISC FORTRAN for execution on a DEC workstation running RISC ULTRIX 3.1 or later. The CRAY version has a central memory requirement of 730279 words. The central memory requirement for the IBM is 150Mb. The memory requirement for the DEC RISC ULTRIX version is 3Mb of main memory. INS3D was developed in 1987. The port to the IBM was done in 1990. The port to the DECstation 3100 was done in 1991. CRAY is a registered trademark of Cray Research Inc. IBM is a registered trademark of International Business Machines. DEC, DECstation, and ULTRIX are trademarks of the Digital Equipment Corporation.

  5. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo

    NARCIS (Netherlands)

    Siebelt, Michiel; Korthagen, Nicoline; Wei, Wu; Groen, Harald; Bastiaansen-Jenniskens, Yvonne; Müller, Christina; Waarsing, Jan Hendrik; de Jong, Marion; Weinans, Harrie

    2015-01-01

    INTRODUCTION: Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence macrophage

  6. New View on the Initial Development Site and Radiographic Classification System of Osteoarthritis of the Knee Based on Radiographic Analysis

    OpenAIRE

    Moon, Ki-Ho

    2012-01-01

    Introduction: Radiographic pathology of severe osteoarthritis of the knee (OAK) such as severe osteophyte at tibial spine (TS), compartment narrowing, marginal osteophyte, and subchondral sclerosis is well known. Kellgren-Lawrence grading system, which is widely used to diagnose OAK, describes narrowing-marginal osteophyte in 4-grades but uses osteophyte at TS only as evidence of OAK without detailed-grading. However, kinematically the knee employs medial TS as an axis while medial and latera...

  7. Successful surgical treatment of a suspected iatrogenic arytenoid cartilage fracture in a dog.

    Science.gov (United States)

    Doran, Ivan; White, Robert N

    2009-01-01

    A 3-year-old, intact female golden retriever was presented with a sudden onset of inspiratory obstructive dyspnea following general anesthesia to perform a mastectomy. The cuneiform process of the left arytenoid cartilage was found to be extremely mobile on laryngeal examination. Fracture of the cuneiform process of the left arytenoid cartilage was diagnosed. A combined cricoarytenoid and thyroarytenoid caudolateralization procedure was performed on the left side, and no further dyspnea was observed during a follow-up period of 7 months. Fracture of the cuneiform process of the arytenoid cartilage has not been previously reported in dogs. The condition may respond favorably to cricoarytenoid and thyroarytenoid caudolateralization surgery.

  8. Investigation of anatomical landmarks for paravertebral anaesthesia ...

    African Journals Online (AJOL)

    The result of this study showed that the spinal nerve emerges from the intervertebral foramina and bifurcates into dorsal and ventral branches with the dorsal nerve branch passing cranially to the body of the succeeding lumbar transverse process in a caudolateral manner. While the ventral branches of the lumbar nerves ...

  9. Intra-Articular Therapeutic Delivery for Post Traumatic Osteoarthritis

    Science.gov (United States)

    2015-10-01

    cartilage Subchondral bone Osteophytes Proteoglycans 3. OVERALL PROJECT SUMMARY: In the first annual funding period (Sept 2014 – Sept 2015...Depiction of medial tibial articular cartilage and subchondral bone quantification regions (medial 1/3 and medial marginal osteophyte ). Figure 7...Conclusions A B C D E 12 Articular cartilage composition, subchondral bone, and osteophyte data showed a beneficial effect of single dHACM injection

  10. 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

    would have difficulty resolving regions of high curvature (for example the local maxima of sharp peaks in the solution). Most of the ideas discussed above...use of improved methods and implementations as they become available. We anticipate that by using the package the sofware development time and...the precise control of the grid at interior points), solution adaptive methods to better resolve the maxima in the E-fields, and semi-automated

  11. Motion of Plasmoid in a Curvilinear Magnetic Field; Mouvement d'un Plasmoide dans un Champ Magnetique Curviligne; Dvizhenie plazmennogo sgustka v krivolinejnom magnitnom pole; Movimiento de un Plasmoide en un Campo Magnetico Curvilineo

    Energy Technology Data Exchange (ETDEWEB)

    Vojcenja, V. S.; Gorbanjuk, A. G.; Onishhenko, I. N.; Safronov, B. G.; Hizhnjak, N. A.; Shkoda, V. V. [Fiziko-Tehnicheskij Institut, AN USSR, Khar' kov, USSR (Ukraine)

    1966-04-15

    The passage of. a plasmoid through the magnetic field of a toroidal solenoid and its decontamination from heavy ion impurities have been studied theoretically and experimentally. The theoretical analysis has been carried out within the framework of a drift approximation. The passage of the plasma is achieved through the closing currents which SinelnikoV assumed to exist. The circuit-closing currents substantially reduce the polarization fields but, as calculations show, do not prevent me drift ofheavy ions to the chamber walls. Even in dense plasma, in which 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} >> 1, the heavy-ion drift is governed by the same laws as in the single-particle approximation. More precise analysis of the field structure shows that, in addition to the polarization field perpendicular to the torus plane, there is a radial electric field directed towards the inner wall of the toroidal chamber. The magnitude of the polarization field is determined essentially by the shorting currents and measurement of the polarization fields therefore confirms indirectly the assumed existence of these currents. Earlier experiments showed that the measured polarization fields agree in order of magnitude with the theoretical predictions. We study the results of the experimental investigation of the passage and decontamination of fast plasmoids of high density (n{sub 0} > 10{sup 13} cm{sup -3}, 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} Asymptotically-Equal-To 5 x 10{sup 3} >> 1). A coaxial source with a pulsed gas inlet was used to obtain the plasmoids (1 cm{sup 3} of hydrogen at atmospheric pressure). The 17-{mu}F source bank was charged to 18 kV. After passing through the rectilinear section of the magnetic field (L = 150 cm) the plasma entered the toroidal magnetic field (radius of curvature, 75 cm; angle of deflection, approximately 90 Degree-Sign ). The magnitude of the pulsed magnetic field reached 10 kOe and remained virtually unchanged during the passage of the plasma (T = 10 ms). A Thompson mass-spectrograph, a transit mass-analyser, electric and high-frequency probes, calorimeters and a plasmascope were employed in the utilization of the plasmoids. On entry into the toroidal solenoid, the velocity of the plasma fronts of density n{sub 1} Tilde-Operator 10{sup 12} cm{sup -3} and n{sub 2} Tilde-Operator 10{sup 13} cm{sup -3} was 7 x 10{sup 7} cm/s. By photometric measurement of the Thompson parabolas, the mean energy of the H{sup +} ions was found to exceed 3 keV while impurities accounted for about 40%. The main impurities were carbon and oxygen ions and the ions of the electrode materials, and their mean energy was higher than that of the hydrogen ions. As the plasmoid moved along the toroidal solenoid, the energy transferred by the plasma and the total number of charged particles decreased by factors of 5 and 3, respectively, for H = 8000 be; at the same time the fraction of fast particles in the H{sup +} ion spectrum declined and the mean energy fell to 2 or 2.5 keV. The velocity of the density front n{sub i} remained unchanged, while that of the density front ne fell to approximately 4 x 10{sup 7} cm/s. The impurities in the fast plasmoid (mainly C{sup ++} and O{sup ++} ions) accounted for about 5%. The mean energy of the impurity ions passing through the toroidal field was approximately half the initial energy (after passing through the straight solenoid). (author) [French] Les auteurs ont etudie du point de vue theorique et experimentalement le passage d'un plasmoiede a travers le champ magnetique d'un soleno'ide torique et l'elimination des impuretes formees d'ions lourds (decontamination). Ils ont procede a l'analyse theorique dans le cadre d'une approximation de derive. Le passage du plasma a ete realise grace a la presence de 'courants de fermeture' dont Sinielriikov avait suppose l'existence. Les courants de fermeture du circuit reduisent sensiblement les champs de polarisation mais, comme le montrent les calculs, n'empechent pas la derive des ions lourds vers; les parois de la chambre. Meme dans les plasmas denses ou 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} >> 1, la derive des ions lourds est soumise aux memes lois que dans l'approximation a une seule particule. Une analyse plus precise de la structure des champs montre qu'en plus du champ de polarisation perpendiculaire au plan du tore, il existe un champ electrique radial dirige vers la paroi interne de la chambre torique. La grandeur du champ de polarisation est determinee essentiellement par des 'courants de raccourcissement ' et, par consequent, la mesure des champs de polarisation confirme indirectement l'hypothese de l'existence de ces champs. Des experiences anterieures oni montre que l'ordre de grandeur des champs de polarisation mesures est en bon accord avec celui des valeurs prevues. Dans le present memoire les auteurs etudient les resultats de la recherche experimentale sur le passage et la decontamination de plasmoiedes rapides a densite elevee (n{sub 0} > 10{sup 13} cm{sup -3}, 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} Asymptotically-Equal-To 5 x 10{sup 3} >> 1). Pour obtenir les plasmoiedes, les auteurs ont utilise une source coaxiale avec admission de gaz puise (1 cm3 d'hydrogene a la pression atmospherique). La batterie source, d'une capacite de 17 {mu}F, etait chargee a 18 kV. Apres le passage a travers la section rectiligne du champ magnetique (L = 150 cm) le plasma est entre dans le champ magnetique torique (rayon de courbure, 75 cm, angle de deflection, environ 90 Degree-Sign ). L'intensite du champ magnetique puise a atteint 10 kOe et est restee pratiquement inchangee pendant le passage du plasma (T = 10 ms). Pour l'utilisation des plasmoiedes on a eu recours a un spectrographe de masse de Thompson, a un analyseur de masse de transit, a des sondes electriques et de haute frequence, a des calorimetres et a un plasmoscope. A l'entree dans le solenoiede torique la vitesse des fronts de plasma de densite n{sub 1} Tilde-Operator 10{sup 12} cm{sup -3} and n{sub 2} Tilde-Operator 10{sup 13} cm{sup -3} et 7 x 10{sup 7} cm/s. La mesure photometrique des paraboles de Thompson a permis de determiner que l'energie moyenne des ions H+ etait superieure a 3 keV, les impuretes comptant pour environ 40%. Les principales impuretes etaient des ions carbone et oxygene et des ions des materiaux des electrodes-, leur energie moyenne etait superieure a l'energie moyenne des ions hydrogene. Au cours du deplacement du plasmoiede le long du solenoiede torique, l'energie transmise par le plasma et le nombre total des particules chargees ont diminue respectivement de 5 et de 3 fois pour H = 8000 Oe. En meme temps, dans le spectre des ions H{sup +} la fraction de particules rapides a diminue et l'energie moyenne est tombee a 2 ou 2,5 keV. La vitesse du front de densite n{sub i} est restee inchangee et la viteSse du front de densite ne est tombee a environ 4 * 10{sup 7} cm/s. Les impuretes dans le plasmoiede rapide (principalement les ions C{sup ++} et O{sup ++}) comptaient pour environ 5%. L'energie moyenne des ions d'impuretes passant par le champ torique etait environ la moitie de l'energie initiale (apres le passage dans le solenoiede rectiligne). (author) [Spanish] Los autores han estudiado teorica y experimentalmente el paso de un plasmoide a traves del campo magnetico de un solenoide toroidal y la eliminacion de las impurezas formadas por iones pesados. El analisis teorico se efectuo por aproximacion de deriva. El paso del plasma se consigue gracias a las 'corrientes de cortocircuito' cuya existencia habfa sido supuesta por K. D. Sinelnikov. Las comentes de cortocircuito reducen sustancialmente los campos de polarizacion, pero, como demuestran los calculos, no impiden la deriva de los iones pesados hacia las paredes de la camara. Incluso en plasmas densos, cuando 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} >> 1, la deriva de los iones pesados se rige por las mismas leyes que la aproximacion de una sola particula. Un analisis mas preciso de la estructura de los campos muestra que ademas del campo de polarizacion perpendicular al plano del toro, existe un campo electrico radial dirigido hacia la pared interior de la camara toroidal. La magnitud del campo de polarizacion se determina esencialmente por las corrientes de cortocircuito; por. ello, la medicion de los campos de polarizacion confirma indirectamente la hipotesis de la existencia de esas corrientes. Algunos experimentos efectuados anteriormente demostraron que los valores medidos de los campos de polarizacion son del mismo orden de magnitud que las previsiones teoricas. En la presente memoria se estudian los resultados de la investigacion experimental del paso y purificacion de los plasmoides rapidos de elevada densidad (n{sub 0} > 10{sup 13} cm{sup -3}, 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} Asymptotically-Equal-To 5 x 10{sup 3} >> 1). Para obtener los plasmoides, los autores utilizaron una fuente coaxial con un gas pulsado (1 cm3 de hidrogeno a presion atmosferica). La bateria de condensadores de 17 {mu}F se cargo a una tension de 18 kV. Despues de casar por la seccion lineal del campo magnetico (L = 150 cm) el plasma penetro en el campo magnetico toroidal (radio de curvatura de 75 cm, angulo de flexion Tilde-Operator 90 Degree-Sign ). La magnitud del campo magnetico pulsado alcanzo 10 kOe y durante el paso del plasma permanecio practicamente constante (T = 10 ms). Para examinar los plasmoides se emplearon un espectrografo de masas de Thompson, un analizador de tiempo de vuelo, sondas electricas y de alta frecuencia, calorimetros y un plasmascopio. Al entrar en el solenoide toroidal la velocidad de los frentes del plasma de densidad n{sub 1} Tilde-Operator 10{sup 12} cm{sup -3} and n{sub 2} Tilde-Operator 10{sup 13} cm{sup -3} era de 7 x 10{sup 7} cm/s. La medicion fotometrica de las parabolas de Thompson permitio determinar que la energia media de los iones H{sup +} era superior a 3 keV, y que la cantidad de impurezas era de un 40%. Las principales impurezas estaban constituidas por iones carbono y oxigeno y por los iones de los materiales de los electrodos, y su energia media era superior a la de los protones. A medida que el plasmoide se fue moviendo a lo largo del solenoide toroidal la energia transferida por el plasma y el numero total de particulas cargadas disminuyeron a un quinto y a un tercio, respectivamente, cuando H = 8000 Oe. Simultaneamente, la proporcion de particulas rapidas disminuyo en el espectro de los iones H{sup +} y la energia media se redujo a 2 - 2,5 keV. La velocidad del frente de densidad nj permanecio constante, pero la velocidad del frente de densidad ne disminuyo hasta Tilde-Operator 4 * 10{sup 7} cm/s. La cantidad de impurezas en el plasmoide rapido (sobre todo iones C{sup ++} y 0{sup ++}) fue de un 5%. La energia media de los iones de las impurezas que habian atravesado el campo toroidal fue unas dos veces inferior a la inicial (despues de atravesar el solenoide recto). (author) [Russian] Teoreticheski i jeksperimental'no izuchalos' prohozhdenie plazmennogo sgustka cherez magnitnoe pole toroidal'nogo solenoida j ochistka jetogo sgustka ot primesej tjazhelyh ionov. Teoreticheskij analiz proveden v ramkah drejfovogo priblizhenija. Prohozhdenie plazmy obespechivaetsja blagodarja nalichiju {sup t}okov zamykanija{sup ,} gipotezu o sushhestvovanii kotoryh vyskazal K.D.Sinel'nikov. Nalichie tokov zamykanija sushhestvenno umen'shaet velichinu poljarizacionnyh polej, no kak pokazali vychislenija, ne prepjatstvuet uhodu tjazhelyh ionov na stenki kamery. Dazhe v plotnyh plazmah, kogda 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} >> 1, drejf tjazhelyh ionov podchinjaetsja tem zhe zakonam, chto i v odnochastichnom priblizhenii. Bolee tochnyj analiz struktury polej pokazyvaet, chto narjadu s polem poljarizacii, perpendikuljarnym ploskosti tora, sushhestvuet radial'noe jelektricheskoe pole, napravlennoe k vnutrennej stenke toroidal'noj kamery. Velichina polja poljarizacii sushhestvenno opredeljaetsja tokami zakorachivanija, pojetomu izmerenie poljarizacionnyh polej kosvenno podtverzhdaet gipotezu sushhestvovanija jetih tokov. Ranee provedennye jeksperimenty pokazali, chto izmerennye poljarizacionnye polja po porjadku velichiny sovpadajut s teoreticheski predskazannymi. V nastojashhej rabote izuchajutsja rezul'taty jeksperimental'nogo issledovanija prohozhdenija i ochistki bystryh plazmennyh sgustkov bol'shoj plotnosti (n{sub 0} > 10{sup 13} cm{sup -3}, 4{pi}n{sub 0}Mc{sup 2}/H{sup 2}{sub 0} Asymptotically-Equal-To 5 x 10{sup 3} >> 1). Dlja poluchenija sgustkov byl ispol'zovan koaksial'nyj istochnik s impul'snym napuskom gaza (1 sm{sup 3} vodoroda pri atmosfernom davlenii). Batareja istochnika emkost'ju 17 mkf zarjazhalas' do naprjazhenija 18 kv. Posle prohozhdenija'prjamolinejnogo uchastka magnitnogo polja (L= 150 sm) plazma popadala v toroidal'noe magnitnoe pole (radius krivizny 75 cm, ugol povorota Tilde-Operator 90 Degree-Sign . Velichina impul'snogo magnitnogo polja dostigala 10 koe i za vremja proleta plazmy ostavalas' prakticheski neizmennoj ( T = 10 msek). Dlja ispol'zovanija sgustkov primenjalis' mass-spektrograf Tomsona, proletnyj mass-analizator, jelektricheskij i vysokochastotnye zondy, kalorimetry i plazmoskop. Na vhode v toroidal'nyj solenoid skorost' frontov plazmy plotnost'ju p{sub 1} Tilde-Operator 10{sup 12} sm{sup -3} ip{sub 2} Tilde-Operator 10{sup 13} sm{sup -3} sostavljala 7 * 10{sup 7} sm/sek. Fotometrirovanie parabol Tomsona dalo vozmozhnost' opredelit', chto srednjaja jenergija ionov N{sup +} prevyshala 3 kjev, a kolichestvo primesej sostavljalo okolo 40% . Osnovnye primesi: iony ugleroda, kisloroda i materialov jelektrodov, ih srednjaja jenergija vyshe, chem srednjaja jenergija ionov vodoroda. Po mere dvizhenija sgustka vdol' toroidal'nogo solenoida jenergija, perenosimaja plazmoj, i polnoe chislo zarjazhennyh chastic umen'shalis', sootvetstvenno, v 5 raz i 3 raza dlja H = 8000 oe. Pri jetom v spektre ionov N{sup +} umen'shalas' dolja bystryh chastic i srednjaja jenergija ponizhalas' do velichiny 2 Division-Sign 2,5 kjev. Skorost' fronta plotnosti ph ostavalas' neizmennoj, a skorost' fronta plotnosti pg padala do velichiny Tilde-Operator 4 * 10{sup 7} sm/sek. Kolichestvo primesej v bystrom sgustke (v osnovnom iony S{sup ++} i 0{sup ++} ) sostavljalo okolo 5%. Srednjaja jenergija ionov primesej, proshedshih toroidal'noe pole, okazalas' primerno v 2 raza men'she, chem nachal'naja (posle prjamogo solenoida). (author)

  12. Degenerative Changes of the Spine of Pilots of the RNLAF

    Science.gov (United States)

    2000-08-01

    views of the spine taken in standing 7-3 Table 2 Classification of disorders Disorder Levels General: Osteo-arthrosis / Spondylosis / Arthrosis...Deformans Cervical, thoracic, lumbar Scoliosis Cervical, thoracic, lumbar Abnormal alignment Cervical, lumbar Scheuermann’s disease / Enchondrosis Thoracic... lumbar Specific: Degenerative changes in the intervertebral disc / Discopathy Cervical, thoracic, lumbar Presence of Osteophyte’s / Osteophytic

  13. Etiology of the anterior ankle impingement syndrome: A descriptive anatomical study

    NARCIS (Netherlands)

    Tol, Johannes L.; van Dijk, C. Niek

    2004-01-01

    Background: In the anterior ankle impingement syndrome, recurrent traction to the anterior joint capsule is stated to be the cause of formation of talotibial osteophytes. This hypothesis involves the assumption that the osteophytes originate at the site where a capsular attachment is located. A soft

  14. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo

    NARCIS (Netherlands)

    M. Siebelt (Michiel); N. Korthagen (Nicoline); W. Wei (Wu); H.C. Groen (Harald); Y.M. Bastiaansen-Jenniskens (Yvonne); C. Müller (Cristina); J.H. Waarsing (Jan); M. de Jong (Marcel); H.H. Weinans (Harrie)

    2015-01-01

    textabstractIntroduction: Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence

  15. Radiographic case definitions and prevalence of osteoarthrosis of the hip: a survey of 4 151 subjects in the Osteoarthritis Substudy of the Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Sonne-Holm, Stig; Søballe, Kjeld

    2004-01-01

    : Formation of cysts, osteophytes and subchondral sclerosis was significantly more frequent in men. Average minimum JSW was narrower in women than in men (p ... composite OA scores emphasizing the relatively inconsequential formation of cysts, osteophytes and subchondral sclerosis runs the risk of over-inflating the prevalence of hip OA in men and of underestimating hip OA prevalence in women....

  16. Diffuse idiopathic skeletal hyperostosis of cervical spine - An unusual cause of difficult flexible fiber optic intubation

    Directory of Open Access Journals (Sweden)

    Baxi Vaibhavi

    2010-01-01

    Full Text Available This is a report of anterior osteophytes on the cervical vertebra resulting in distortion of the airway and leading to difficulty during intubation. The osteophytes associated with the syndrome of diffuse idiopathic skeletal hyperostosis were at the C2-3 and C6-7, T1 level and resulted in anterior displacement of the pharynx and the trachea respectively.

  17. Nonlinear continua fundaments for the computational techniques

    CERN Document Server

    Dvorkin, Eduardo N

    2005-01-01

    Offers a presentation of Continuum Mechanics, oriented towards numerical applications in the nonlinear analysis of solids, structures and fluid mechanics. This book develops general curvilinear coordinator kinematics of the continuum deformation using general curvilinear coordinates.

  18. Oblique radiograph for the detection of bone spurs in anterior ankle impingement

    International Nuclear Information System (INIS)

    Dijk, Niek C. van; Wessel, Ronald N.; Tol, Johannes L.; Maas, M.

    2002-01-01

    Objective: The aim of this study was to develop a radiographic view to detect anteromedial talotibial osteophytes that remain undetected on standard radiographs. Design and patients: In 10 cadaver specimens the maximal size was measured of anteromedial tibial osteophytes that remain undetected on a standard lateral radiograph projection, due to the presence of the anteromedial tibial rim. The average projection of the most prominent anterolateral tibial rim over the anteromedial rim was found to be 7.3 mm. A 7 mm barium-clay osteophyte was attached to this anteromedial rim of the distal tibia. Anteromedial osteophytes become most prominent on an oblique view, in which the radiographic beam is tilted into a 45 craniocaudal direction with the leg in 30 external rotation. This oblique view was compared with the findings of arthroscopic surgery in 25 consecutive patients with anterior ankle impingement syndrome. Results: Medially located tibial and talar osteophytes remained undetected on a standard lateral projection and became visible on the oblique anteromedial impingement (AMI) radiograph. Anterolateral tibial and talar osteophytes were well detected on a standard lateral radiograph projection but were invisible on the AMI view. There was a high correlation between the location of the osteophyte and the location of symptoms and the findings at arthroscopy. Conclusion: A combination of lateral and oblique radiographs can be used to differentiate between anteromedial and anterolateral bony ankle impingement. (orig.)

  19. An ultrasonographic study of metatarsophalangeal joint pain: synovitis, structural pathology and their relationship to symptoms and function.

    Science.gov (United States)

    Keen, Helen I; Redmond, Anthony; Wakefield, Richard J; Freeston, Jane; Grainger, Andrew J; Hensor, Elizabeth M A; Emery, Paul; Conaghan, Philip G

    2011-12-01

    Pain in the first metatarsophalangeal joint (MTPJ) is common, though the link between pathology and symptoms is poorly understood. To examine the relationship between pain, function and ultrasound (US)-detected pathology in the first MTPJ. 33 subjects with first MTPJ pain and 20 asymptomatic controls completed questionnaires about pain and function, then underwent clinical examination, US examination and objective assessment of function using a motion tracking system. Low-level grey scale synovitis and osteophytes were common in patients and controls. Osteophytes were more prevalent in symptomatic first MTPJ [24/33 (73%) vs. 7/20 (35%), p=0.007], and greater osteophyte numbers were weakly associated with higher levels of pain [increase in pain VAS per osteophyte (95% CI)=13.78mm (0.12mm-27.43mm), p=0.048]. A power Doppler (PD) signal was present in a fifth of painful first MTPJs and absent in controls. A PD signal was associated with osteophytes and joint space narrowing but was not independently related to target joint pain. For all first MTPJs, osteophytes and the presence of a PD signal was associated with worse patient-reported function. US features did not predict objective function. Osteophytes, representing subchondral bone remodelling, were associated with the presence of first MTPJ pain and, together with more severe (PD) synovitis, also contributed to poorer function. Detailed imaging of bone may provide more information on peripheral pain associations.

  20. New view on the initial development site and radiographic classification system of osteoarthritis of the knee based on radiographic analysis.

    Science.gov (United States)

    Moon, Ki-Ho

    2012-12-01

    Radiographic pathology of severe osteoarthritis of the knee (OAK) such as severe osteophyte at tibial spine (TS), compartment narrowing, marginal osteophyte, and subchondral sclerosis is well known. Kellgren-Lawrence grading system, which is widely used to diagnose OAK, describes narrowing-marginal osteophyte in 4-grades but uses osteophyte at TS only as evidence of OAK without detailed-grading. However, kinematically the knee employs medial TS as an axis while medial and lateral compartments carry the load, suggesting that early OAK would occur sooner at TS than at compartment. Then, Kellgren-Lawrence system may be inadequate to diagnose early-stage OAK manifested as a subtle osteophyte at TS without narrowing-marginal osteophyte. This undiagnosed-OAK will deteriorate becoming a contributing factor in an increasing incidence of OAK. This study developed a radiographic OAK-marker based on both osteophyte at TS and compartment narrowing-marginal osteophyte and graded as normal, mild, moderate, and severe. With this marker, both knee radiographs of 1,728 patients with knee pain were analyzed. Among 611 early-stage mild OAK, 562 or 92% started at TS and 49 or 8% at compartment. It suggests the initial development site of OAK, helping develop new site-specific radiographic classification system of OAK accurately to diagnose all severity of OAK at early, intermediate, or late-stage. It showed that Kellgren-Lawrence system missed 92.0% of early-stage mild OAK from diagnosis. A subtle osteophyte at TS is the earliest radiographic sign of OAK. A new radiographic classification system of OAK was suggested for accurate diagnosis of all OAK in severity and at stage.

  1. Intra- and interobserver agreement of computed tomography in assessment of the mandibular condyle

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Bong Hae; Jung, Yun Hoa [Pusan National Univ. College of Dentistry, Pusan (Korea, Republic of)

    2007-12-15

    To study the intra- and interobserver agreement of multidetector row computed tomography (MDCT) in interpretation of degenerative changes of the mandibular condyle. Five observers independently evaluated one hundred temporomandibular joint MDCT images for signs of osteophytes, erosion, sclerosis and flattening. The intra- and interobserve agreements were calculated by using Kappa statistics. The intraobserver agreement was substantial for erosion (k=0.75), flattening (k=0.74) and sclerosis (k=0.72) and almost perfect for osteophytes (k=0.84). The interobserver agreement was fair for flattening (k=0.39), moderate for erosion (k=0.58) and sclerosis (k=0.48) and substantial for osteophytes (k=0.75). This study shows that we can expert good agreement for the presence of osteophytes, but not for flattening in the interpretation of MDCT images of the condyle.

  2. 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...

  3. 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

  4. FK506 protects against articular cartilage collagenous extra-cellular matrix degradation

    NARCIS (Netherlands)

    M. Siebelt (Michiel); A.E. van der Windt (Anna); H.C. Groen (Harald); M. Sandker (Marjan); J.H. Waarsing (Jan); C. Müller (Cristina); M. de Jong (Marcel); H. Jahr (Holger); H.H. Weinans (Harrie)

    2014-01-01

    textabstractObjective: Osteoarthritis (OA) is a non-rheumatologic joint disease characterized by progressive degeneration of the cartilage extra-cellular matrix (ECM), enhanced subchondral bone remodeling, activation of synovial macrophages and osteophyte growth. Inhibition of calcineurin (Cn)

  5. ADOLESCENT CHONDROLYSIS OF THE mp JOINT*

    African Journals Online (AJOL)

    1971-02-20

    Feb 20, 1971 ... slight reduction of joint space and osteophyte formation at the capital margin ... ring and irregularity of the subchondral line and an increase of CE angle, .... Unfortunately histological examination was not carried out. As the hip ...

  6. Assessment of Biomarkers Associated with Joint Injury and Subsequent Post Traumatic Arthritis

    Science.gov (United States)

    2015-10-01

    quantitative scales, and osteophyte score. Parametric analyses were performed for bone morphological measures and histological assessment. Mankin...p=0.0204) and the medial tibia (p=0.0015). Subchondral bone thickening was significantly increased in the C57BL/6 mice compared to the MRL/MpJ mice...modified synovitis score with semi-quantitative scales, and osteophyte score [1,5,6,7,8]. Parametric analyses were performed for bone morphological

  7. The Incidence of Primary Hip Osteoarthritis in Active Duty US Military Servicemembers

    Science.gov (United States)

    2009-04-15

    presence of particular radiographic features: osteophytes , joint space narrowing, subchondral sclerosis, and cysts. It is estimated that OA affects 27...followed for 15 years found radiologic evidence of OA consisting of subchondral scle- rosis (59%) and osteophyte formation (29%) in their co- hort (39...struction of articular cartilage and proliferation and re- modeling of subchondral bone. Symptomatic OA is a clin- ical diagnosis based on pain in the

  8. Comparison of clinical, radionuclide, and radiographic features of osteoarthritis of the hands.

    OpenAIRE

    Macfarlane, D G; Buckland-Wright, J C; Emery, P; Fogelman, I; Clark, B; Lynch, J

    1991-01-01

    Simultaneous clinical, scintigraphic, and macroradiographic assessments were carried out on 32 patients with hand osteoarthritis and the results at entry and one year reported. The presence and growth of osteophyte correlated with symptoms and a positive scan. The scan did not detect the radiographic features of juxta-articular radiolucencies, subchondral sclerosis, or cartilage thinning. Osteophytes, particularly when fast growing, produce pain, a 'hot' scan, and may predict disintegration o...

  9. Diagnostic performance of 3D standing CT imaging for detection of knee osteoarthritis features.

    Science.gov (United States)

    Segal, Neil A; Nevitt, Michael C; Lynch, John A; Niu, Jingbo; Torner, James C; Guermazi, Ali

    2015-07-01

    To determine the diagnostic performance of standing computerized tomography (SCT) of the knee for osteophytes and subchondral cysts compared with fixed-flexion radiography, using MRI as the reference standard. Twenty participants were recruited from the Multicenter Osteoarthritis Study. Participants' knees were imaged with SCT while standing in a knee-positioning frame, and with postero-anterior fixed-flexion radiography and 1T MRI. Medial and lateral marginal osteophytes and subchondral cysts were scored on bilateral radiographs and coronal SCT images using the OARSI grading system and on coronal MRI using Whole Organ MRI Scoring. Imaging modalities were read separately with images in random order. Sensitivity, specificity and accuracy for the detection of lesions were calculated and differences between modalities were tested using McNemar's test. Participants' mean age was 66.8 years, body mass index was 29.6 kg/m(2) and 50% were women. Of the 160 surfaces (medial and lateral femur and tibia for 40 knees), MRI revealed 84 osteophytes and 10 subchondral cysts. In comparison with osteophytes and subchondral cysts detected by MRI, SCT was significantly more sensitive (93 and 100%; p osteophytes) than plain radiographs (sensitivity 60 and 10% and accuracy 79 and 94%, respectively). For osteophytes, differences in sensitivity and accuracy were greatest at the medial femur (p = 0.002). In comparison with MRI, SCT imaging was more sensitive and accurate for detection of osteophytes and subchondral cysts than conventional fixed-flexion radiography. Additional study is warranted to assess diagnostic performance of SCT measures of joint space width, progression of OA features and the patellofemoral joint.

  10. COMPARISONS AMONG RADIOGRAPHY, ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY FOR EX VIVO CHARACTERIZATION OF STIFLE OSTEOARTHRITIS IN THE HORSE.

    Science.gov (United States)

    De Lasalle, Julie; Alexander, Kate; Olive, Julien; Laverty, Sheila

    2016-09-01

    A better understanding of imaging characteristics of equine stifle osteoarthritis (OA) may allow earlier detection and improve prognosis. Objectives of this ex vivo, prospective, methods comparison study were to (1) describe the location and severity of naturally acquired OA lesions in the equine stifle using ultrasound (US), radiography (XR), computed tomography (CT), and macroscopic evaluation (ME); (2) compare the diagnostic performance of each imaging modality with ME; and (3) describe subchondral bone mineral density (BMD) in equine stifle joints with OA using CT. Radiographic, CT, and US evaluations were performed on 23 equine cadaver stifles and compared with ME. Significant associations were found between osteophyte global scores for all imaging modalities (CT, P ˂ 0.0001; XR, P = 0.005; US, P = 0.04) vs. ME osteophyte global scores. Osteophytes were detected most frequently in the medial femorotibial (MFT) joint. A specific pattern of osteophytes was observed, with a long ridge of new bone at the insertion of the MFT joint capsule cranially on the medial femoral condyle. A novel caudo-10°proximo-5°lateral-cranio-disto-medial oblique radiographic projection was helpful for detection of intercondylar osteophytes. Multiplanar CT reformatted images were helpful for characterizing all osteophytes. Osteophyte grades at most sites did not differ among modalities. Low sensitivity/specificity for subchondral bone sclerosis and flattening of femoral condyles suggested that these signs may not be reliable radiographic and CT indicators of equine stifle OA. Equine stifle OA was associated with a decrease in BMD and specific sites of focal subchondral bone resorption/cyst formation were found in some specimens. © 2016 American College of Veterinary Radiology.

  11. Correlation between radiographic findings of osteoarthritis and arthroscopic findings of articular cartilage degeneration within the patellofemoral joint

    International Nuclear Information System (INIS)

    Kijowski, Richard; Blankenbaker, Donna; Stanton, Paul; De Smet, Arthur; Fine, Jason

    2006-01-01

    To correlate radiographic findings of osteoarthritis on axial knee radiographs with arthroscopic findings of articular cartilage degeneration within the patellofemoral joint in patients with chronic knee pain. The study group consisted of 104 patients with osteoarthritis of the patellofemoral joint and 30 patients of similar age with no osteoarthritis of the patellofemoral joint. All patients in the study group had an axial radiograph of the knee performed prior to arthroscopic knee surgery. At the time of arthroscopy, each articular surface of the patellofemoral joint was graded using the Noyes classification system. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the various radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the patellofemoral joint were determined. The sensitivity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 73%, 37%, 4%, and 0% respectively. The specificity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 67%, 90%, 100%, and 100% respectively. Marginal osteophytes were the most sensitive radiographic feature for the detection of articular cartilage degeneration within the patellofemoral joint. Joint-space narrowing, subchondral sclerosis, and subchondral cysts were insensitive radiographic features of osteoarthritis, and rarely occurred in the absence of associated osteophyte formation. (orig.)

  12. Correlation between radiographic findings of osteoarthritis and arthroscopic findings of articular cartilage degeneration within the patellofemoral joint

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Blankenbaker, Donna; Stanton, Paul; De Smet, Arthur [University of Wisconsin Hospital Clinical Science Center-E3/311, Department of Radiology, Madison, WI (United States); Fine, Jason [University of Wisconsin Clinical Science Center-K6/4675, Department of Statistics, Madison, WI (United States)

    2006-12-15

    To correlate radiographic findings of osteoarthritis on axial knee radiographs with arthroscopic findings of articular cartilage degeneration within the patellofemoral joint in patients with chronic knee pain. The study group consisted of 104 patients with osteoarthritis of the patellofemoral joint and 30 patients of similar age with no osteoarthritis of the patellofemoral joint. All patients in the study group had an axial radiograph of the knee performed prior to arthroscopic knee surgery. At the time of arthroscopy, each articular surface of the patellofemoral joint was graded using the Noyes classification system. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the various radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the patellofemoral joint were determined. The sensitivity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 73%, 37%, 4%, and 0% respectively. The specificity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 67%, 90%, 100%, and 100% respectively. Marginal osteophytes were the most sensitive radiographic feature for the detection of articular cartilage degeneration within the patellofemoral joint. Joint-space narrowing, subchondral sclerosis, and subchondral cysts were insensitive radiographic features of osteoarthritis, and rarely occurred in the absence of associated osteophyte formation. (orig.)

  13. Correlation between radiographic findings of osteoarthritis and arthroscopic findings of articular cartilage degeneration within the patellofemoral joint.

    Science.gov (United States)

    Kijowski, Richard; Blankenbaker, Donna; Stanton, Paul; Fine, Jason; De Smet, Arthur

    2006-12-01

    To correlate radiographic findings of osteoarthritis on axial knee radiographs with arthroscopic findings of articular cartilage degeneration within the patellofemoral joint in patients with chronic knee pain. The study group consisted of 104 patients with osteoarthritis of the patellofemoral joint and 30 patients of similar age with no osteoarthritis of the patellofemoral joint. All patients in the study group had an axial radiograph of the knee performed prior to arthroscopic knee surgery. At the time of arthroscopy, each articular surface of the patellofemoral joint was graded using the Noyes classification system. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the various radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the patellofemoral joint were determined. The sensitivity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 73%, 37%, 4%, and 0% respectively. The specificity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 67%, 90%, 100%, and 100% respectively. Marginal osteophytes were the most sensitive radiographic feature for the detection of articular cartilage degeneration within the patellofemoral joint. Joint-space narrowing, subchondral sclerosis, and subchondral cysts were insensitive radiographic features of osteoarthritis, and rarely occurred in the absence of associated osteophyte formation.

  14. Elongated Styloid Process and Cervical Spondylosis

    Directory of Open Access Journals (Sweden)

    Zeliha Unlu MD

    2008-01-01

    Full Text Available Background Dysphagia, is a significant sign of many different lesions in upper digestive system especially in proximal esophagus. Tumors, gastroesophageal reflux, achalasia and extrinsic compressions are the most common causes that may lead to dysphagia in geriatric population. Cervical osteophyte induced dysphagia, is one of the uncommon reasons of dysphagia, therefore other causes of dysphagia must be excluded to establish the exact diagnosis. Eagle syndrome is one of the considerable reason which may lead to misdiagnosis in patients with cervical osteophytes. In this case report, we represent four patients who had dysphagia due to anteriorly located cervical osteophytes and evaluate the patients with special reference to Eagle syndrome. Material and methods After a detailed anamnesis and ENT examination, cervical plain radiographs in four projections and Towne radiographs were obtained for every patient. After that, magnetic resonance imaging (MRI of cervical spine and barium swallowing studies were performed to evaluate the presence of esophageal compression. Results Eagle syndrome was excluded due to absence of other symptoms and physical signs, eventhough unilateral or bilateral elongation of styloid processes was found in all of the patients. Conclusion Cervical osteophytes induced dysphagia is a rare clinical entity, diagnosis should be done by a careful examination, intensive radiologic evaluation. Moreover, all the other causes like Eagle syndrome should be excluded during the diagnosis of cervical osteophyte induced dysphagia.

  15. 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…

  16. Stress fractures of the humerus, radius, and tibia in horses: clinical features and radiographic and/or scintigraphic appearance

    International Nuclear Information System (INIS)

    Mackey, V.S.; Trout, D.R.; Meagher, D.M.; Hornof, W.J.

    1987-01-01

    The medical records, radiographic and nuclear scintigraphic findings of 26 racing horses with 27 stress fracture episodes of the humerus, radius, or tibia were reviewed. The purposes of this study were to describe the radiographic and/or scintigraphic features of stress fractures of the humerus, radius, or tibia, and to evaluate the signalment and history of horses in which stress fracture occurred. Stress fractures of the three long bones examined were primarily seen in 2- and 3-year-old male Thoroughbred horses; commonly, the onset of lameness was immediately following training gallops or racing. There were 13 humeral stress fracture episodes in 12 horses. Ten were in the proximal caudolateral cortex, and three were in the distal craniomedial cortex. Radical stress fractures were seen in three horses, all in the midshaft radius. Tibial stress fractures were diagnosed in 11 horses. They were located in the proximal lateral tibia in six horses, the distal caudolateral tibia in three horses, and the midshaft tibia in three horses. Fifteen stress fractures were diagnosed with radiography alone, one was diagnosed with scintigraphy alone, nine were diagnosed with radiographs and scintigraphy, and, in two horses, radiographs were negative, but the scintigraphic findings were consistent with stress fracture

  17. Neuromagnetic detection of the laryngeal area: Sensory-evoked fields to air-puff stimulation.

    Science.gov (United States)

    Miyaji, Hideaki; Hironaga, Naruhito; Umezaki, Toshiro; Hagiwara, Koichi; Shigeto, Hiroshi; Sawatsubashi, Motohiro; Tobimatsu, Shozo; Komune, Shizuo

    2014-03-01

    The sensory projections from the oral cavity, pharynx, and larynx are crucial in assuring safe deglutition, coughing, breathing, and voice production/speaking. Although several studies using neuroimaging techniques have demonstrated cortical activation related to pharyngeal and laryngeal functions, little is known regarding sensory projections from the laryngeal area to the somatosensory cortex. The purpose of this study was to establish the cortical activity evoked by somatic air-puff stimulation at the laryngeal mucosa using magnetoencephalography. Twelve healthy volunteers were trained to inhibit swallowing in response to air stimuli delivered to the larynx. Minimum norm estimates was performed on the laryngeal somatosensory evoked fields (LSEFs) to best differentiate the target activations from non-task-related activations. Evoked magnetic fields were recorded with acceptable reproducibility in the left hemisphere, with a peak latency of approximately 100ms in 10 subjects. Peak activation was estimated at the caudolateral region of the primary somatosensory area (S1). These results establish the ability to detect LSEFs with an acceptable reproducibility within a single subject and among subjects. These results also suggest the existence of laryngeal somatic afferent input to the caudolateral region of S1 in human. Our findings indicate that further investigation in this area is needed, and should focus on laryngeal lateralization, swallowing, and speech processing. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Technetium 99m methylene diphosphonate bone scanning in osteoarthritic hands

    International Nuclear Information System (INIS)

    Buckland-Wright, J.C.; Lynch, J.A.; Macfarlane, D.G.; Homoeopathic Hospital, Tunbridge; Fogelman, I.; Emery, P.

    1991-01-01

    In this prospective study, the radiological features characteristic of osteoarthritis of the hand were compared with the radionuclide bone scan images. A total of 32 patients was assessed at 6-monthly intervals for 18 months. Microfocal radiographs were taken at each visit. The high magnification and resolution of this technique permitted direct measurement of joint space width, subchondral sclerosis, osteophyte number and area and juxta-articular radiolucency area for each joint in the hand. Four-hour technetium 99m methylene diphosphonate bone scans were taken at 0 and 12 months and the activity of tracer uptake at each joint scored. The latter was compared with each X-radiographic feature at every visit and the changes between visits analysed. The scan scores did not correlate with any of the X-radiographic features other than osteophyte size. During the study the size of growing and remodelling osteophytes increased significantly at joints with raised or increased isotope uptake. (orig.)

  19. Technetium 99m methylene diphosphonate bone scanning in osteoarthritic hands

    Energy Technology Data Exchange (ETDEWEB)

    Buckland-Wright, J.C.; Lynch, J.A. (United Medical and Dental Schools of Guy' s and Saint Thomas' , London (UK). Dept. of Anatomy); Macfarlane, D.G. (United Medical and Dental Schools of Guy' s and Saint Thomas' , London (UK). Dept. of Anatomy Homoeopathic Hospital, Tunbridge (UK). Dept. of Rheumatology); Fogelman, I. (United Medical and Dental Schools of Guy' s and Saint Thomas' , London (UK). Dept. of Nuclear Medicine); Emery, P. (United Medical and Dental Schools of Guy' s and Saint Thomas' , London (UK). Dept. of Rheumatology)

    1991-01-01

    In this prospective study, the radiological features characteristic of osteoarthritis of the hand were compared with the radionuclide bone scan images. A total of 32 patients was assessed at 6-monthly intervals for 18 months. Microfocal radiographs were taken at each visit. The high magnification and resolution of this technique permitted direct measurement of joint space width, subchondral sclerosis, osteophyte number and area and juxta-articular radiolucency area for each joint in the hand. Four-hour technetium 99m methylene diphosphonate bone scans were taken at 0 and 12 months and the activity of tracer uptake at each joint scored. The latter was compared with each X-radiographic feature at every visit and the changes between visits analysed. The scan scores did not correlate with any of the X-radiographic features other than osteophyte size. During the study the size of growing and remodelling osteophytes increased significantly at joints with raised or increased isotope uptake. (orig.).

  20. The distribution and inter-relationships of radiologic features of osteoarthrosis of the hip. A survey of 4151 subjects of the Copenhagen City Heart Study: the Osteoarthrosis Substudy

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Sonne-Holm, Stig; Søballe, Kjeld

    2004-01-01

    -relationships and correlations to age, sex, body mass index (BMI) and occupational exposure to repeated lifting. RESULTS: Overall, subchondral sclerosis, cysts and osteophytes were more frequently recorded in male hip joints compared to female hip joints, while a decrease in minimum JSW by age was more pronounced...... and progressive in women after the fifth decade compared to men. Applying logistic regression analyses, only age was found to be significantly associated to pathologically reduced minimum JSW (cut off value set at osteophytes and subchondral cysts in both sexes (P ranging from 0.......00 to 0.03). Minimum JSW subchondral cysts, osteophytes and sclerosis were found to be significantly inter-related to minimum JSW

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

    International Nuclear Information System (INIS)

    Xu, Li; Hayashi, Daichi; Guermazi, Ali; Hunter, David J.; Li, Ling; Winterstein, Anton; Bohndorf, Klaus; Roemer, Frank W.

    2013-01-01

    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.)

  2. Proteinase-activated receptor 2 modulates OA-related pain, cartilage and bone pathology.

    Science.gov (United States)

    Huesa, Carmen; Ortiz, Ana C; Dunning, Lynette; McGavin, Laura; Bennett, Louise; McIntosh, Kathryn; Crilly, Anne; Kurowska-Stolarska, Mariola; Plevin, Robin; van 't Hof, Rob J; Rowan, Andrew D; McInnes, Iain B; Goodyear, Carl S; Lockhart, John C; Ferrell, William R

    2016-11-01

    Proteinase-activated receptor 2 (PAR2) deficiency protects against cartilage degradation in experimental osteoarthritis (OA). The wider impact of this pathway upon OA-associated pathologies such as osteophyte formation and pain is unknown. Herein, we investigated early temporal bone and cartilage changes in experimental OA in order to further elucidate the role of PAR2 in OA pathogenesis. OA was induced in wild-type (WT) and PAR2-deficient (PAR2 -/- ) mice by destabilisation of the medial meniscus (DMM). Inflammation, cartilage degradation and bone changes were monitored using histology and microCT. In gene rescue experiments, PAR2 -/- mice were intra-articularly injected with human PAR2 (hPAR2)-expressing adenovirus. Dynamic weight bearing was used as a surrogate of OA-related pain. Osteophytes formed within 7 days post-DMM in WT mice but osteosclerosis was only evident from 14 days post induction. Importantly, PAR2 was expressed in the proliferative/hypertrophic chondrocytes present within osteophytes. In PAR2 -/- mice, osteophytes developed significantly less frequently but, when present, were smaller and of greater density; no osteosclerosis was observed in these mice up to day 28. The pattern of weight bearing was altered in PAR2 -/- mice, suggesting reduced pain perception. The expression of hPAR2 in PAR2 -/- mice recapitulated osteophyte formation and cartilage damage similar to that observed in WT mice. However, osteosclerosis was absent, consistent with lack of hPAR2 expression in subchondral bone. This study clearly demonstrates PAR2 plays a critical role, via chondrocytes, in osteophyte development and subchondral bone changes, which occur prior to PAR2-mediated cartilage damage. The latter likely occurs independently of OA-related bone changes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Proteinase-activated receptor 2 modulates OA-related pain, cartilage and bone pathology

    Science.gov (United States)

    Huesa, Carmen; Ortiz, Ana C; Dunning, Lynette; McGavin, Laura; Bennett, Louise; McIntosh, Kathryn; Crilly, Anne; Kurowska-Stolarska, Mariola; Plevin, Robin; van ‘t Hof, Rob J; Rowan, Andrew D; McInnes, Iain B; Goodyear, Carl S; Lockhart, John C; Ferrell, William R

    2016-01-01

    Objective Proteinase-activated receptor 2 (PAR2) deficiency protects against cartilage degradation in experimental osteoarthritis (OA). The wider impact of this pathway upon OA-associated pathologies such as osteophyte formation and pain is unknown. Herein, we investigated early temporal bone and cartilage changes in experimental OA in order to further elucidate the role of PAR2 in OA pathogenesis. Methods OA was induced in wild-type (WT) and PAR2-deficient (PAR2−/−) mice by destabilisation of the medial meniscus (DMM). Inflammation, cartilage degradation and bone changes were monitored using histology and microCT. In gene rescue experiments, PAR2−/− mice were intra-articularly injected with human PAR2 (hPAR2)-expressing adenovirus. Dynamic weight bearing was used as a surrogate of OA-related pain. Results Osteophytes formed within 7 days post-DMM in WT mice but osteosclerosis was only evident from 14 days post induction. Importantly, PAR2 was expressed in the proliferative/hypertrophic chondrocytes present within osteophytes. In PAR2−/− mice, osteophytes developed significantly less frequently but, when present, were smaller and of greater density; no osteosclerosis was observed in these mice up to day 28. The pattern of weight bearing was altered in PAR2−/− mice, suggesting reduced pain perception. The expression of hPAR2 in PAR2−/− mice recapitulated osteophyte formation and cartilage damage similar to that observed in WT mice. However, osteosclerosis was absent, consistent with lack of hPAR2 expression in subchondral bone. Conclusions This study clearly demonstrates PAR2 plays a critical role, via chondrocytes, in osteophyte development and subchondral bone changes, which occur prior to PAR2-mediated cartilage damage. The latter likely occurs independently of OA-related bone changes. PMID:26698846

  4. 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.)

  5. Osteoarthritis of the atlanto-odontoid joint

    International Nuclear Information System (INIS)

    Genez, B.M.; Woodruff, W.W.; Laverman, W.C.; Willis, J.J.; Lowrey, C.; Diaz, M.J.

    1989-01-01

    The authors have investigated the incidence and the radiographic and CT findings of atlanto- odontoid degenerative arthrosis. The authors have reviewed 120 cervical spine radiographs for evidence of osteophytes of the atlas and odontoid, correlating these findings with lower cervical spine changes in each patient. Thirty patients also had CT examinations of the craniovertebral junction, permitting determination of sensitivity and specificity of radiographic findings. CT revealed occult changes, such as cysts, paraarticular osteophytes and intraarticular calcifications. Clinical examination in 16 patients showed decreased head rotation, vertigo, and neck and suboccipital pain

  6. Spontaneous resolution of posterior ankle joint loose bodies after total ankle replacement: A case report.

    Science.gov (United States)

    Lee, Raymond P; Cheng, Sally H S

    2017-06-01

    Late stage ankle osteoarthritis often presents with debilitating pain. It is common to find osteophytes and loose body formation around the joint. Total ankle arthroplasty can preserve joint mobility and pain relieve for such patient. However, when trying to remove the osteophytes and loose bodies at the posterior ankle joint, there is risk of damaging posterior structures such as the neurovascular bundle during the procedure. We are presenting a case where the posterior loose bodies remained untouched during the operation, and patient showed spontaneous resolution of the lesions with time. Patient enjoyed good function outcome after the surgery. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  7. Current Titles in Turkish Science. Volume 6. Numbers 7-9, July-August-September 1979

    Science.gov (United States)

    1979-01-01

    19 (2) 173-177. (5 refs. Tu. , en.) (79-1882) KARACADAÜ §., BERlLGEN A. Dysphagia due to cervical osteophytes (A case report). Hacettepe...gulairova D. Tip Fak. Derg. (1979) 4 (I) 26-33. (19 refs. Tu., en. ) (79-1923) ONAT, Allan. Dradycardio-depondent Wolff- Parkinson -White

  8. Intra Articular Therapeutic Delivery for Post Traumatic Osteoarthritis

    Science.gov (United States)

    2016-10-01

    size distribution therapeutic timepoints EPIC-µCT Articular cartilage Subchondral bone Osteophytes Proteoglycans 3. OVERALL PROJECT SUMMARY: In...joint degeneration induced by MMT. Previously documented in Year 1 annual report: Changes in articular cartilage and subchondral bone morphology...and resulted in increased cartilage thickness at 3 weeks. The majority of alterations to subchondral bone (density, thickness) were detected at 3

  9. Long-term clinical results in patients treated for recurrent posterolateral elbow joint instability using an ipsilateral triceps tendon graft

    DEFF Research Database (Denmark)

    Kastenskov, Christian; Rasmussen, Jeppe Vejlgaard; Ovesen, Janne

    2017-01-01

    version of Oxford Elbow Score. Furthermore, conventional anteroposterior and side-view radiographs of the elbow were obtained to evaluate osteoarthritis, calcifications in the ligaments, and joint subluxation. We evaluated the radiographs by the size of osteophytes, joint space narrowing, and subchondral...

  10. Obesity and osteoarthritis, more than just wear and tear: pivotal roles for inflamed adipose tissue and dyslipidaemia in obesity-induced osteoarthritis

    NARCIS (Netherlands)

    Thijssen, E.; Caam, A.P. van; Kraan, P.M. van der

    2015-01-01

    OA is a degenerative joint disease characterized by articular cartilage degradation, osteophyte formation, synovitis, and subchondral bone sclerosis. One of OAs main risk factors is obesity. To date, it is not fully understood how obesity results in OA. Historically, this link was ascribed to

  11. Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

    Science.gov (United States)

    Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W.; Arokoski, Jari P.; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T.; Tervonen, Osmo; Koski, Juhani M.; Saarakkala, Simo

    2016-01-01

    Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level. PMID:26926836

  12. Two phenotypes of arthropathy in long-term controlled acromegaly? A comparison between patients with and without joint space narrowing (JSN)

    NARCIS (Netherlands)

    Claessen, K. M. J. A.; Kloppenburg, M.; Kroon, H. M.; Romijn, J. A.; Pereira, A. M.; Biermasz, N. R.

    2013-01-01

    Arthropathy is an invalidating complication of acromegaly, also in long-term controlled patients, and is radiographically characterized by osteophytes and preserved joint spaces. However, joint space narrowing (JSN) is observed in the minority of patients. It is unknown whether JSN is the end-stage

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

    NARCIS (Netherlands)

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

    2005-01-01

    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. A cross-sectional study was carried out on 35 outpatients with osteoarthritis of the knee.

  14. THE CHOICE OF A RATIONAL STRUCTURAL DESIGN OF ELECTRODYNAMIC TRANSPORT SYSTEMS

    Directory of Open Access Journals (Sweden)

    M. O. Radchenko

    2009-03-01

    Full Text Available The design schemes of electrodynamic maglev systems with a plane track structure are developed and the results of investigation of levitating motion of such systems along rectilinear or curvilinear tracks are presented.

  15. 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

    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....

  16. 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)

  17. The Impact of Operations Tempo (OPTEMPO) on Intentions to Depart the Military. Does the Increase of OPTEMPO Cause Action

    National Research Council Canada - National Science Library

    Olsen, Nathan P

    2008-01-01

    .... This study evaluated the August 2004 Status of Forces Survey to determine if the sample demonstrated OPTEMPO had a curvilinear effect on turnover intentions when accounting for the moderators job...

  18. Self-organizing maps: A tool to ascertain taxonomic relatedness ...

    Indian Academy of Sciences (India)

    MADHU

    what is known as numerical taxonomy (Garrity et al. 2001). ... Curvilinear component analysis; self-organizing maps; principal component analysis. Abbreviations used: ... This tool undergoes unsupervised learning and is particularly useful in ...

  19. 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)

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

    International Nuclear Information System (INIS)

    Wu, H.; Webber, C.; Fuentes, C.O.; Benson, R.; Beattie, K.; Adachi, J.D.; Xie, X.; Jabbari, F.; Levy, D.R.

    2007-01-01

    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)

  1. 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

  2. No associations between self-reported knee joint instability and radiographic features in knee osteoarthritis patients prior to Total Knee Arthroplasty: A cross-sectional analysis of the Longitudinal Leiden Orthopaedics Outcomes of Osteo-Arthritis study (LOAS) data.

    Science.gov (United States)

    Leichtenberg, Claudia S; Meesters, Jorit J L; Kroon, Herman M; Verdegaal, Suzan H M; Tilbury, Claire; Dekker, Joost; Nelissen, Rob G H H; Vliet Vlieland, Thea P M; van der Esch, Martin

    2017-08-01

    To describe the prevalence of self-reported knee joint instability in patients with pre-surgery knee osteoarthritis (OA) and to explore the associations between self-reported knee joint instability and radiological features. A cross-sectional study including patients scheduled for primary Total Knee Arthroplasty (TKA). Self-reported knee instability was examined by questionnaire. Radiological features consisted of osteophyte formation and joint space narrowing (JSN), both scored on a 0 to three scale. Scores >1 are defined as substantial JSN or osteophyte formation. Regression analyses were provided to identify associations of radiological features with self-reported knee joint instability. Two hundred and sixty-five patients (mean age 69years and 170 females) were included. Knee instability was reported by 192 patients (72%). Substantial osteophyte formation was present in 78 patients (41%) reporting and 33 patients (46%) not reporting knee joint instability. Substantial JSN was present in 137 (71%) and 53 patients (73%), respectively. Self-reported knee instability was not associated with JSN (relative to score 0, odds ratios (95% CI) of score 1, 2 and 3 were 0.87 (0.30-2.54), 0.98 (0.38-2.52), 0.68 (0.25-1.86), respectively) or osteophyte formation (relative to score 0, odds ratios (95% CI) of score 1, 2 and 3 were 0.77 (0.36-1.64), 0.69 (0.23-1.45), 0.89 (0.16-4.93), respectively). Stratified analysis for pain, age and BMI showed no associations between self-reported knee joint instability and radiological features. Self-reported knee joint instability is not associated with JSN or osteophyte formation. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. [Study on the correlation between syndrome differ classification of knee osteoarthritis and X-ray image].

    Science.gov (United States)

    Jin, Li-Kun; Zhang, Guo-Zhong; Tang, Ke; Liu, Yang

    2010-12-01

    To study the correlation between syndrome differ classification of knee osteoarthritis and X-ray image, so as to provide evidence for clinical diagnosis and treatment. From Jun. 2007 to Dec. 2007, 78 patients (108 knees) with knee osteoarthritis were reviewed, including 65 females (89 knees) and 13 males (19 knees), ranging in age from 41 to 77 years. According to the standards for the differentiation of syndrome in the treatment of knee osteoarthritis defined in Principle of Clinical Research for New Traditional Herbs, the patients were divided into three types: Type I, insufficiency of the liver and kidney, with stagnation of tendons and muscles, 43 knees; Type II, insufficiency of the spleen and kidney, with dampness infusion into bone and joints, 26 knees; Type I, deficiency of the liver and kidney, with inter-obstruction of phlegm and stasis 39 knees. Normotopia and lateral plain film of knee joint of weigh loading and in erect position, and patellofemoral Skyline plain flim was taken. Joint space narrow, osteophyte generation, subchondral osteosclerosis and subchondral cystic degeneration were evaluated. All data were analyzed by K independent samples nonparametric test in order to find out the correlation between syndrome differ classification of knee osteoarthritis and X-ray image. It was shown that after K independent samples nonparametric test about syndrome differ classification of knee osteoarthritis and X-ray image: there were significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte and Type II was the most serious, Type I was secondary, Type II was the lightest. Other index had no obvious difference among the three groups. There is certain correlation between syndrome differ classification of knee osteoarthritis and X-ray image. There are significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte, the Type II is the most serious,Type I is secondary, Type II

  4. An enhanced structure tensor method for sea ice ridge detection from GF-3 SAR imagery

    Science.gov (United States)

    Zhu, T.; Li, F.; Zhang, Y.; Zhang, S.; Spreen, G.; Dierking, W.; Heygster, G.

    2017-12-01

    In SAR imagery, ridges or leads are shown as the curvilinear features. The proposed ridge detection method is facilitated by their curvilinear shapes. The bright curvilinear features are recognized as the ridges while the dark curvilinear features are classified as the leads. In dual-polarization HH or HV channel of C-band SAR imagery, the bright curvilinear feature may be false alarm because the frost flowers of young leads may show as bright pixels associated with changes in the surface salinity under calm surface conditions. Wind roughened leads also trigger the backscatter increasing that can be misclassified as ridges [1]. Thus the width limitation is considered in this proposed structure tensor method [2], since only shape feature based method is not enough for detecting ridges. The ridge detection algorithm is based on the hypothesis that the bright pixels are ridges with curvilinear shapes and the ridge width is less 30 meters. Benefited from GF-3 with high spatial resolution of 3 meters, we provide an enhanced structure tensor method for detecting the significant ridge. The preprocessing procedures including the calibration and incidence angle normalization are also investigated. The bright pixels will have strong response to the bandpass filtering. The ridge training samples are delineated from the SAR imagery in the Log-Gabor filters to construct structure tensor. From the tensor, the dominant orientation of the pixel representing the ridge is determined by the dominant eigenvector. For the post-processing of structure tensor, the elongated kernel is desired to enhance the ridge curvilinear shape. Since ridge presents along a certain direction, the ratio of the dominant eigenvector will be used to measure the intensity of local anisotropy. The convolution filter has been utilized in the constructed structure tensor is used to model spatial contextual information. Ridge detection results from GF-3 show the proposed method performs better compared to the

  5. Elbow arthroscopy: valgus extension overload.

    Science.gov (United States)

    Ahmad, Christopher S; Conway, John E

    2011-01-01

    Valgus torque combined with deceleration produces high compression and shear forces acting on the posteromedial olecranon and the posteromedial trochlea. This valgus extension overload process may cause posteromedial trochlea chondromalacia, chondral flap formation, osteochondrosis, subchondral erosion, a subchondral insufficiency fracture, and marginal exostosis formation. Olecranon pathologies include proximal stress reaction, a posteromedial tip stress fracture, a transverse proximal process stress fracture, exostosis formation, exostosis fragmentation, and intra-articular loose bodies. Symptoms include posteromedial elbow pain during the deceleration phase of the throwing motion. The extension impingement test reproduces posterior or posteromedial pain similar to that experienced while throwing. Special radiographic techniques and CT scans can show loose bodies and osteophyte fragmentation. Surgical treatment is indicated when symptoms persist despite nonsurgical management. Based on clinical and basic science research, all patients with valgus extension overload should be comprehensively evaluated for medial ulnar collateral ligament insufficiency. Surgical treatment is limited to the resection of osteophytes only; normal olecranon should not be resected.

  6. Diffuse idiopathic skeletal hyperostosis inducted stridor and dysphagia.

    Science.gov (United States)

    Burduk, Paweł K; Wierzchowska, Małgorzata; Grzelalak, Lech; Dalke, Krzysztof; Mierzwiński, Józef

    2008-01-01

    Diffuse Idiopathic Skeletal Hyperostosis (DISH) is a condition characterized by calcification and ossification of soft tissues, mainly ligaments and enthesis. Dysphagia is the commonest complaint, stridor secondary to osteophyte compression has rarely been documented. The osteophytes may cause symptoms by mechanical compression or by inducting inflammatory reaction. When an upper segment of the C-spine is involved, particular C3 - C4 level, the larynx may be affected. This could be result of hoarseness, stridor, laryngeal stenosis and obstruction. Sometimes vocal fold paralysis may result from injury to the recurrent laryngeal nerve. Treatment of the breathing problems required first on stabilization the airway with tracheostomy. Next step is osteophysectomy which generally relief patients from symptoms.

  7. 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

  8. Associations between MRI-defined structural pathology and generalized and localized knee pain - the Oulu Knee Osteoarthritis study.

    Science.gov (United States)

    Kaukinen, P; Podlipská, J; Guermazi, A; Niinimäki, J; Lehenkari, P; Roemer, F W; Nieminen, M T; Koski, J M; Arokoski, J P A; Saarakkala, S

    2016-09-01

    To determine the associations between multi-feature structural pathology assessed using magnetic resonance imaging (MRI) and the presence of knee pain, and to determine the associations between the locations of structural changes and different knee pain patterns. Eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee OA and 63 asymptomatic subjects underwent knee MRI. Severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. The associations between cartilage damage, bone marrow lesions (BMLs), osteophytes, Hoffa's synovitis, effusion-synovitis, meniscal damage and structural pathologies in ligaments, tendons and bursas and both the presence of pain and the knee pain patterns were assessed. The presence of Hoffa's synovitis (adjusted RR 1.6, 95% CI 1.2-1.3) and osteophytes in any region (2.07, 1.19-3.60) was significantly associated with the presence of pain. Any Hoffa's synovitis was associated with patellar pain (adjusted RR 4.70, 95% CI 1.19-3.60) and moderate-to-severe Hoffa's synovitis with diffuse pain (2.25, 1.13-4.50). Medial knee pain was associated with cartilage loss in the medial tibia (adjusted RR 2.66, 95% CI 1.22-5.80), osteophytes in the medial tibia (2.66, 1.17-6.07) and medial femur (2.55, 1.07-6.09), medial meniscal maceration (2.20, 1.01-4.79) and anterior meniscal extrusions (2.78, 1.14-6.75). Hoffa's synovitis and osteophytes were strongly associated with the presence of knee pain. Medial pain was associated most often with medially located structural pathologies. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Early X-ray diagnosis of coxarthrosis

    International Nuclear Information System (INIS)

    Lingg, G.; Nebel, G.

    1982-01-01

    Radiological and pathological comparisons on specimen of femurhead 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 shows to be a very sensitive indicator of early arthrosis. So there exist semiquantitative parameters for the X-ray diagnosis of early coxarthrosis. (orig.) [de

  10. Episodic vertigo resulting from vascular risk factors, cervical spondylosis and head rotation: Two case reports

    OpenAIRE

    Owolabi, Mayowa O; Ogah, Okechukwu S; Ogunniyi, Adesola

    2007-01-01

    Background Vascular risk factors predispose to vertebrobasilar ischemia. Cervical osteophytes can impinge on the vertebral artery causing mechanical occlusion during head turning. Presentation with vertigo in such instances is a common finding. Case presentation A patient with obesity, hyperlipidemia, hypertension, cervical spondylosis, and vertigo triggered by head rotation is presented. She responded to antihypertensive and lipid-lowering drugs, vestibular sedative and application of cervic...

  11. The Effect of the PEEK Cage on the Cervical Lordosis in Patients Undergoing Anterior Cervical Discectomy

    Directory of Open Access Journals (Sweden)

    Salih Gulsen

    2015-03-01

    CONCLUSION: We achieved better cervical lordotic angles at the postoperative period by implanting one-level, two-level, three-level or four-level PEEK cage filled with demineralized bone matrix. Also, the causes of cervical root and or medulla spinalis impingement were different in group1 and 2. While extruded cervical disc impingement was the first pathology in group 1, osteophyte formation was the first pathology in group 2.

  12. Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis.

    Science.gov (United States)

    Das Neves Borges, Patricia; Vincent, Tonia L; Marenzana, Massimo

    2017-01-01

    The degradation of articular cartilage, which characterises osteoarthritis (OA), is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal changes in periarticular bone in murine OA by novel, automated micro-CT methods. OA was induced by destabilisation of the medial meniscus (DMM) in 10-week old male mice and disease assessed cross-sectionally from 1- to 20-weeks post-surgery. A novel approach was developed to automatically segment subchondral bone compartments into plate and trabecular bone in micro-CT scans of tibial epiphyses. Osteophyte volume, as assessed by shape differences using 3D image registration, and by measuring total epiphyseal volume was performed. Significant linear and volumetric structural modifications in subchondral bone compartments and osteophytes were measured from 4-weeks post-surgery and showed progressive changes at all time points; by 20 weeks, medial subchondral bone plate thickness increased by 160±19.5 μm and the medial osteophyte grew by 0.124±0.028 μm3. Excellent agreement was found when automated measurements were compared with manual assessments. Our automated methods for assessing bone changes in murine periarticular bone are rapid, quantitative, and highly accurate, and promise to be a useful tool in future preclinical studies of OA progression and treatment. The current approaches were developed specifically for cross-sectional micro-CT studies but could be applied to longitudinal studies.

  13. An inflammation-responsive transcription factor in the pathophysiology of osteoarthritis.

    Science.gov (United States)

    Ray, Alpana; Ray, Bimal K

    2008-01-01

    A number of risk factors including biomechanical stress on the articular cartilage imposed by joint overloading due to obesity, repetitive damage of the joint tissues by injury of the menisci and ligaments, and abnormal joint alignment play a significant role in the onset of osteoarthritis (OA). Genetic predisposition can also lead to the formation of defective cartilage matrix because of abnormal gene expression in the cartilage-specific cells. Another important biochemical event in OA is the consequence of inflammation. It has been shown that synovial inflammation triggers the synthesis of biological stimuli such as cytokines and growth factors which subsequently reach the chondrocyte cells of the articular cartilage activating inflammatory events in the chondrocytes leading to cartilage destruction. In addition to cartilage degradation, hypertrophy of the subchondral bone and osteophyte formation at the joint margins also takes place in OA. Both processes involve abnormal expression of a number of genes including matrix metalloproteinases (MMPs) for cartilage degradation and those associated with bone formation during osteophyte development. To address how diverse groups of genes are activated in OA chondrocyte, we have studied their induction mechanism. We present evidence for abundant expression of an inflammation-responsive transcription factor, SAF-1, in moderate to severely damaged OA cartilage tissues. In contrast, cells in normal cartilage matrix contain very low level of SAF-1 protein. SAF-1 is identified as a major regulator of increased synthesis of MMP-1 and -9 and pro-angiogenic factor, vascular endothelial growth factor (VEGF). While VEGF by stimulating angiogenesis plays a key role in new bone formation in osteophyte, increase of MMP-1 and -9 is instrumental for cartilage erosion in the pathogenesis of OA. Increased expression in degenerated cartilage matrix and in the osteophytes indicate for a key regulatory role of SAF-1 in directing catabolic

  14. PET/MRI of metabolic activity in osteoarthritis: A feasibility study.

    Science.gov (United States)

    Kogan, Feliks; Fan, Audrey P; McWalter, Emily J; Oei, Edwin H G; Quon, Andrew; Gold, Garry E

    2017-06-01

    To evaluate positron emission tomography / magnetic resonance imaging (PET/MRI) knee imaging to detect and characterize osseous metabolic abnormalities and correlate PET radiotracer uptake with osseous abnormalities and cartilage degeneration observed on MRI. Both knees of 22 subjects with knee pain or injury were scanned at one timepoint, without gadolinium, on a hybrid 3.0T PET-MRI system following injection of 18 F-fluoride or 18 F-fluorodeoxyglucose (FDG). A musculoskeletal radiologist identified volumes of interest (VOIs) around bone abnormalities on MR images and scored bone marrow lesions (BMLs) and osteophytes using a MOAKS scoring system. Cartilage appearance adjacent to bone abnormalities was graded with MRI-modified Outerbridge classifications. On PET standardized uptake values (SUV) maps, VOIs with SUV greater than 5 times the SUV in normal-appearing bone were identified as high-uptake VOI (VOI High ). Differences in 18 F-fluoride uptake between bone abnormalities, BML, and osteophyte grades and adjacent cartilage grades on MRI were identified using Mann-Whitney U-tests. SUV max in all subchondral bone lesions (BML, osteophytes, sclerosis) was significantly higher than that of normal-appearing bone on MRI (P subchondral bone on MRI. Furthermore, many small grade 1 osteophytes (40 of 82 [49%]), often described as the earliest signs of osteoarthritis (OA), did not show high uptake. Lastly, PET SUV max in subchondral bone adjacent to grade 0 cartilage was significantly lower compared to that of grades 1-2 (P subchondral bone, which appear normal on MRI. 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;45:1736-1745. © 2016 International Society for Magnetic Resonance in Medicine.

  15. Knee Images Digital Analysis (KIDA): a novel method to quantify individual radiographic features of knee osteoarthritis in detail.

    Science.gov (United States)

    Marijnissen, A C A; Vincken, K L; Vos, P A J M; Saris, D B F; Viergever, M A; Bijlsma, J W J; Bartels, L W; Lafeber, F P J G

    2008-02-01

    Radiography is still the golden standard for imaging features of osteoarthritis (OA), such as joint space narrowing, subchondral sclerosis, and osteophyte formation. Objective assessment, however, remains difficult. The goal of the present study was to evaluate a novel digital method to analyse standard knee radiographs. Standardized radiographs of 20 healthy and 55 OA knees were taken in general practise according to the semi-flexed method by Buckland-Wright. Joint Space Width (JSW), osteophyte area, subchondral bone density, joint angle, and tibial eminence height were measured as continuous variables using newly developed Knee Images Digital Analysis (KIDA) software on a standard PC. Two observers evaluated the radiographs twice, each on two different occasions. The observers were blinded to the source of the radiographs and to their previous measurements. Statistical analysis to compare measurements within and between observers was performed according to Bland and Altman. Correlations between KIDA data and Kellgren & Lawrence (K&L) grade were calculated and data of healthy knees were compared to those of OA knees. Intra- and inter-observer variations for measurement of JSW, subchondral bone density, osteophytes, tibial eminence, and joint angle were small. Significant correlations were found between KIDA parameters and K&L grade. Furthermore, significant differences were found between healthy and OA knees. In addition to JSW measurement, objective evaluation of osteophyte formation and subchondral bone density is possible on standard radiographs. The measured differences between OA and healthy individuals suggest that KIDA allows detection of changes in time, although sensitivity to change has to be demonstrated in long-term follow-up studies.

  16. MTHFR Gene C677T Mutation and ACE Gene I/D Polymorphism in Turkish Patients with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Ahmet Inanir

    2013-01-01

    Full Text Available Osteoarthritis is a degenerative joint disorder resulting in destruction of articular cartilage, osteophyte formation, and subchondral bone sclerosis. In recent years, numerous genetic factors have been identified and implicated in osteoarthritis. The aim of the current study was to examine the influence of methylenetetrahydrofolate reductase (MTHFR gene C677T mutation and angiotensin converting enzyme (ACE gene insertion/deletion (I/D variations on the risk of osteoarthritis.

  17. Empirical evaluation of the inter-relationship of articular elements involved in the pathoanatomy of knee osteoarthritis using magnetic resonance imaging.

    Science.gov (United States)

    Meredith, Dennis S; Losina, Elena; Neumann, Gesa; Yoshioka, Hiroshi; Lang, Philipp K; Katz, Jeffrey N

    2009-10-29

    In this cross-sectional study, we conducted a comprehensive assessment of all articular elements that could be measured using knee MRI. We assessed the association of pathological change in multiple articular structures involved in the pathoanatomy of osteoarthritis. Knee MRI scans from patients over 45 years old were assessed using a semi-quantitative knee MRI assessment form. The form included six distinct elements: cartilage, bone marrow lesions, osteophytes, subchondral sclerosis, joint effusion and synovitis. Each type of pathology was graded using an ordinal scale with a value of zero indicating no pathology and higher values indicating increasingly severe levels of pathology. The principal dependent variable for comparison was the mean cartilage disease score (CDS), which captured the aggregate extent of involvement of articular cartilage. The distribution of CDS was compared to the individual and cumulative distributions of each articular element using the Chi-squared test. The correlations between pathological change in the various articular structures were assessed in a Spearman correlation table. Data from 140 patients were available for review. The cohort had a median age of 61 years (range 45-89) and was 61% female. The cohort included a wide spectrum of OA severity. Our analysis showed a statistically significant trend towards pathological change involving more articular elements as CDS worsened (p-value for trend osteophytes (p-value for trend subchondral sclerosis (p = 0.009), but not joint effusion or synovitis. There was a moderate correlation between cartilage damage, osteophytes and BMLs as well as a moderate correlation between joint effusion and synovitis. However, cartilage damage and osteophytes were only weakly associated with synovitis or joint effusion. Our results support an inter-relationship of multiple articular elements in the pathoanatomy of knee OA. Prospective studies of OA pathogenesis in humans are needed to correlate these

  18. Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis.

    Directory of Open Access Journals (Sweden)

    Patricia Das Neves Borges

    Full Text Available The degradation of articular cartilage, which characterises osteoarthritis (OA, is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal changes in periarticular bone in murine OA by novel, automated micro-CT methods.OA was induced by destabilisation of the medial meniscus (DMM in 10-week old male mice and disease assessed cross-sectionally from 1- to 20-weeks post-surgery. A novel approach was developed to automatically segment subchondral bone compartments into plate and trabecular bone in micro-CT scans of tibial epiphyses. Osteophyte volume, as assessed by shape differences using 3D image registration, and by measuring total epiphyseal volume was performed.Significant linear and volumetric structural modifications in subchondral bone compartments and osteophytes were measured from 4-weeks post-surgery and showed progressive changes at all time points; by 20 weeks, medial subchondral bone plate thickness increased by 160±19.5 μm and the medial osteophyte grew by 0.124±0.028 μm3. Excellent agreement was found when automated measurements were compared with manual assessments.Our automated methods for assessing bone changes in murine periarticular bone are rapid, quantitative, and highly accurate, and promise to be a useful tool in future preclinical studies of OA progression and treatment. The current approaches were developed specifically for cross-sectional micro-CT studies but could be applied to longitudinal studies.

  19. Molecular changes in articular cartilage and subchondral bone in the rat anterior cruciate ligament transection and meniscectomized models of osteoarthritis

    OpenAIRE

    Zhuo Ya; Hayami Tadashi; Pickarski Maureen; Duong Le T

    2011-01-01

    Abstract Background Osteoarthritis (OA) is a debilitating, progressive joint disease. Methods Similar to the disease progression in humans, sequential events of early cartilage degradation, subchondral osteopenia followed by sclerosis, and late osteophyte formation were demonstrated in the anterior cruciate ligament transection (ACLT) or ACLT with partial medial meniscectomy (ACLT + MMx) rat OA models. We describe a reliable and consistent method to examine the time dependent changes in the g...

  20. Automated assessment of bone changes in cross-sectional micro-CT studies of murine experimental osteoarthritis

    OpenAIRE

    Das Neves Borges, P; Vincent, TL; Marenzana, M; Espinoza Orías, AA

    2017-01-01

    OBJECTIVE: The degradation of articular cartilage, which characterises osteoarthritis (OA), is usually paired with excessive bone remodelling, including subchondral bone sclerosis, cysts, and osteophyte formation. Experimental models of OA are widely used to investigate pathogenesis, yet few validated methodologies for assessing periarticular bone morphology exist and quantitative measurements are limited by manual segmentation of micro-CT scans. The aim of this work was to chart the temporal...

  1. Subchondral bone in osteoarthritis: insight into risk factors and microstructural changes

    OpenAIRE

    Li, Guangyi; Yin, Jimin; Gao, Junjie; Cheng, Tak S; Pavlos, Nathan J; Zhang, Changqing; Zheng, Ming H

    2013-01-01

    Osteoarthritis (OA) is a major cause of disability in the adult population. As a progressive degenerative joint disorder, OA is characterized by cartilage damage, changes in the subchondral bone, osteophyte formation, muscle weakness, and inflammation of the synovium tissue and tendon. Although OA has long been viewed as a primary disorder of articular cartilage, subchondral bone is attracting increasing attention. It is commonly reported to play a vital role in the pathogenesis of OA. Subcho...

  2. 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.

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

    OpenAIRE

    Teena Bansal; Rajmala Jaiswal; Arnab Banerjee

    2016-01-01

    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 ...

  4. 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.)

  5. Locking of metacarpophalangeal joints in a patient with acromegaly

    International Nuclear Information System (INIS)

    Tani, Y.; Tanaka, N.; Isoya, Eiji

    1999-01-01

    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.)

  6. Generation and Development of Paravertebral Ossification in Cervical Artificial Disk Replacement: A Detailed Analytic Report Using Coronal Reconstruction CT.

    Science.gov (United States)

    Tian, Wei; Han, Xiao; Liu, Bo; He, Da; Lv, Yanwei; Yue, James

    2017-04-01

    A retrospective follow-up study and review of images in published papers. To determine whether true heterotopic ossification (HO) occurs in artificial disk replacement (ADR); to evaluate the incidence of paravertebral ossification (PO) and its influence on ADR. HO is typically defined as the abnormal formation of true bone within extraskeletal soft tissues. However, HO in ADR does not fit this definition precisely, as it originates from vertebral body, making it hard to distinguish radiologically from preexisting osteophytes. In this study, the term used for bone formation around ADR is PO. First, all images in the published papers were evaluated as to whether the presented PO in ADR fit the classic definition of HO or osteophytes. Second, we studied 37 consecutive patients who underwent ADR and follow-up for minimum 24 months. The preoperative and follow-up incidence of PO and its influence on range of motion were evaluated using x-ray and computed tomography. All 52 images of PO were found adjacent to the disk in 1 segment rather than entire cervical spine. Fifty (96.2%) of the POs were found to originate from the vertebral body rather than in the soft tissue. A total of 31 patients were included in the follow-up study. No significant difference was found in the incidence of PO between the follow-up and preoperation (61.29% vs. 48.39%, P>0.05). The range of motion of the ADR segment in patients with progressed PO (7.44±4.64 degrees) was significantly lower than that of patients with stable PO grade (12.13±4.42 degrees, P<0.01) at last follow-up. A proportion of HO might in fact be the natural development of preoperative osteophytes, which is unrelated to ADR; the remaining HO might be due to changes in biomechanical environment after surgery, which promotes the grade of osteophytes and affects the segment motion.

  7. 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.

  8. Management of an unusual sciatica.

    Science.gov (United States)

    Bourghli, Anouar; Chaballout, Ahmed; Obeid, Ibrahim; Boissiere, Louis; Vital, Jean-Marc; Khoury, Ghassan

    2016-11-01

    Extraforaminal entrapment of the L5 nerve root is uncommon, and its management can sometimes be very challenging. We present the case of a 57-year-old female, complaining of a sciatica in her left leg, for 3 years, with no response to any kind of conservative treatment. MRI and CT scan revealed the presence of a large L5S1 strictly lateral osteophyte compressing the left L5 root in its extraforaminal path. The patient underwent a left anterior retroperitoneal approach with assistance from a vascular surgeon given the very close relation between the osteophyte and the left common iliac vein, lying just on top of it, osteophyte was removed in one piece with the use of an osteotome after retraction of the vessels. The patient progressively recovered from her left sciatic pain with a satisfactory clinical result at 1 year. Literature is sparse on the treatment of extraforaminal entrapment of the L5 nerve root; the current case shows a successful treatment strategy with the use of an anterior approach for direct vision of the lesion and good control of the vessels.

  9. Single photon emission computed tomography in lumbar degenerative spondylolisthesis

    International Nuclear Information System (INIS)

    Ito, S.; Muro, T.; Eisenstein, S.

    1998-01-01

    Analysis of single photon emission computed tomographic images and plain X-ray films of the lumbar vertebrae was performed in 15 patients with lumbar spondylosis and 15 patients with lumbar degenerative spondylolisthesis. The facet joint and osteophyte images were observed in particular, and the slipping ratio of spondylolisthetic vertebrae was determined. The slipping ratio of degenerative spondylolisthesis ranged from 11.8 % to 22.3 %. Hot uptake of 99mTc-HMDP by both L4-5 facet joints was significantly greater in the patients with degenerative spondylolisthesis than in those with lumbar spondylosis. The hot uptake by the osteophytes in lumbar spondylosis was nearly uniform among the three inferior segments, L3-4, L4-5 and L5-S, but was localized to the spondylolisthetic vertebrae, L4-5, or L5-S, in the patients with spondylolisthesis. Half of the osteophytes with hot uptake were assigned to the 3rd degree of Nathan's grading. It was suggested that stress was localized to the slipping vertebrae and their facet joints in patients with lumbar degenerative spondylolisthesis. (author)

  10. CT findings of cervical spondylosis associated with muscle atrophy in the upper extremity

    Energy Technology Data Exchange (ETDEWEB)

    Torigoe, Yasuyuki [Okayama Univ. (Japan). School of Medicine

    1995-11-01

    The shape, site and size of osteophytes in cervical spondylosis associated with muscle atrophy were studied by CT to know their relation with pathogenesis. Subjects were: muscle atrophy group (30 cases, 59.5-year-old in a mean, operation was performed on 26), spondylosis group (20, 60.0 year-old) and normal group (10, 60.2-year-old). Their cervical vertebral regions were subjected to the scout roentgenography, CT and myelography. Osteophytes were measured on the x-ray film copied from CT-monitoring image. In the muscle atrophy group, about the shape around vertebral foramen, the occipitofrontal diameter of vertebral canal was found larger than in spondylosis group. Osteophytes were often localized at the outer position of paramedian site, of which constriction was rather smaller. The shape of the vertebral arch was keen. Clinically, the muscle atrophy group was considered to be of myelosis under such conditions as having less affective lesion on spinal cord. (H.O.)

  11. Association between Patient History and Physical Examination and Osteoarthritis after Ankle Sprain.

    Science.gov (United States)

    van Ochten, John M; de Vries, Anja D; van Putte, Nienke; Oei, Edwin H G; Bindels, Patrick J E; Bierma-Zeinstra, Sita M A; van Middelkoop, Marienke

    2017-09-01

    Structural abnormalities on MRI are frequent after an ankle sprain. To determine the association between patient history, physical examination and early osteoarthritis (OA) in patients after a previous ankle sprain, 98 patients with persistent complaints were selected from a cross-sectional study. Patient history taking and physical examination were applied and MRI was taken. Univariate and multivariable analyses were used to test possible associations. Signs of OA (cartilage loss, osteophytes and bone marrow edema) were seen in the talocrural joint (TCJ) in 40% and the talonavicular joint (TNJ) in 49%. Multivariable analysis showed a significant positive association between swelling (OR 3.58, 95%CI 1.13;11.4), a difference in ROM of passive plantar flexion (OR 1.09, 95%CI 1.01;1.18) and bone edema in the TCJ. A difference in ROM of passive plantar flexion (OR 1.07, 95%CI 1.00;1.15) and pain at the end range of dorsiflexion/plantar flexion (OR 5.23, 95%CI 1.88;14.58) were associated with osteophytes in the TNJ. Pain at the end of dorsiflexion/plantar flexion, a difference in ROM of passive plantar flexion and swelling seem to be associated with features of OA (bone marrow edema, osteophytes) in the TCJ and TNJ. Our findings may guide physicians to predict structural joint abnormalities as signs of osteoarthritis. 1b. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Association between clinical and cone-beam computed tomography findings in patients with temporomandibular disorders

    Directory of Open Access Journals (Sweden)

    Mahrokh Imanimoghaddam

    2017-08-01

    Full Text Available BACKGROUND AND AIM: The aim of this study was to assess the association between the clinical and cone-beam computed tomography (CBCT findings in relation to bony changes in patients with temporomandibular disorders (TMD. METHODS: According to the research diagnostic criteria for temporomandibular disorder (RDC/TMD, forty-one patients with type II TMD (42 TM joints and type III TMD (40 TM joints were recruited for this study. Condylar position and bony changes including flattening, sclerosis, osteophytes, resorption, and erosion of joint were evaluated by CBCT and compared with clinical findings. Data were analyzed by SPSS software. RESULTS: Condylar flattening, sclerosis, resorption, and erosion were not significantly associated with joint/masticatory muscles pain or crepitus sound. The vertical or horizontal position of the condyle showed no significant relationship with the clinical findings. Condylar osteophyte was significantly associated with pain in masticatory muscles and crepitus (P = 0.030 and P = 0.010, respectively. There was no association between the condylar range of motion and pain in joint or masticatory muscles. CONCLUSION: Condylar osteophyte was significantly associated with both masticatory muscles pain and crepitus sound. No significant relationship was found between the other temporomandibular joint (TMJ radiographic and clinical findings in patients with TMD.

  13. Laterality of radiographic osteoarthritis of the knee.

    Science.gov (United States)

    Komatsu, Daigo; Ikeuchi, Kazuma; Kojima, Toshihisa; Takegami, Yasuhiko; Amano, Takafumi; Tsuboi, Masaki; Ishiguro, Naoki; Hasegawa, Yukiharu

    2017-05-01

    There are few reports of the laterality in radiological knee osteoarthritis (ROA). This study aimed to evaluate laterality in terms of the minimum joint space width (mJSW) and osteophyte areas (OFs) in a cross-sectorial general population screen and elucidate the association between laterality and risk of osteoarthritis. We enrolled 330 participants (mean age 64.6 years) and examined the presence of ROA (Kellgren-Lawrence grade ≧ 2) laterality in terms of the mJSW and OF on the medial tibia using auto-measuring software. Moreover, we examined the association between laterality and leg dominance. The right and left medial mJSWs were 4.02 ± 0.98 mm and 4.05 ± 1.01 mm, respectively, showing no laterality; the laterals were also similar. The participants who had osteophytes ≥1 mm 2 in the right, left, and bilateral knees were 15, 37, and 57 respectively, with osteophytes being significantly more common in the left knee. The OF was significantly larger in the left knee. Conversely, the medial and lateral mJSWs and OF did not differ according to leg dominance. The prevalence of ROA was higher and the OF was more pronounced in the left knee. However, the mJSW showed no laterality. Additionally, the mJSW and OF showed no differences according to leg dominance.

  14. Evaluation of instability after transtrochanteric anterior rotational osteotomy for nontraumatic osteonecrosis of the femoral head

    International Nuclear Information System (INIS)

    Hiranuma, Yasunari; Atsumi, Takashi; Kajiwara, Toshihisa; Tamaoki, Satoshi; Asakura, Yasuhiro

    2009-01-01

    Transtrochanteric anterior rotational osteotomy results in improvement of joint congruity and prevention of progressive collapse and osteoarthritic changes in patients with femoral head osteonecrosis. However, this procedure remains controversial for patients with extensive collapse due to potential osteoarthritis caused by postoperative instability. The purpose of this study was to evaluate hip instability after osteotomy and determine the relation between instability and radiological and clinical outcomes. In all, 27 hips of 24 patients that were followed up for a mean period of 3.8 years were included. Instability was defined as more than 1 mm translation of the femoral head in transverse computed tomography scans obtained at 0 deg and 45 deg flexion of the hip joint. Hips were divided into instability and stability groups. Eleven hips (40%) developed instability after surgery. Osteophytes on the femoral head in 10 hips of the instability group and 2 hips of the stability group had increased in size at follow-up. There was a significant relation between postoperative instability and osteophyte formation. Joint space narrowing was not seen in any of the cases. There was no significant difference between the groups in either the postoperative intact ratio of the femoral head or the Japanese Orthopaedic Association hip score. Neither instability nor osteophyte formation on the femoral head after transtrochanteric anterior rotational osteotomy correlated with progressive osteoarthritic changes or clinical outcome in the presence of an adequate femoral head intact ratio facing the weight-bearing area. (author)

  15. Further evidence of the developmental origins of osteoarthritis: results from the Hertfordshire Cohort Study.

    Science.gov (United States)

    Clynes, M A; Parsons, C; Edwards, M H; Jameson, K A; Harvey, N C; Sayer, A Aihie; Cooper, C; Dennison, E M

    2014-12-01

    Investigators have suggested a link between birth weight and both hand and lumbar spine osteoarthritis (OA). In this study, we sought to extend these observations by investigating relationships between growth in early life, and clinical and radiological diagnoses of OA at the hand, knee and hip, among participants from the Hertfordshire Cohort Study. Data were available for 222 men and 222 women. Clinical OA was defined based on American College of Rheumatology criteria. Radiographs were taken of the knees and hips, and graded for the presence of osteophytes and overall Kellgren and Lawrence (KL) score. Lower weight at year one was associated with higher rates of clinical hand OA (OR 1.396, 95% CI 1.05, 1.85, P=0.021). Individuals with lower birth weights were more likely to have hip osteophytes (OR 1.512, 95% CI 1.14, 2.00, P=0.004) and this remained robust after adjustment for confounders. Furthermore, a low weight at one year was also associated with a higher osteophyte number in the lateral compartment of the knee, after adjustment for confounders (OR 1.388, 95% CI 1.01, 1.91, P=0.043). We have found further evidence of a relationship between early life factors and adult OA. These findings accord with previous studies.

  16. Severity mapping of the proximal femur: a new method for assessing hip osteoarthritis with computed tomography.

    Science.gov (United States)

    Turmezei, T D; Lomas, D J; Hopper, M A; Poole, K E S

    2014-10-01

    Plain radiography has been the mainstay of imaging assessment in osteoarthritis for over 50 years, but it does have limitations. Here we present the methodology and results of a new technique for identifying, grading, and mapping the severity and spatial distribution of osteoarthritic disease features at the hip in 3D with clinical computed tomography (CT). CT imaging of 456 hips from 230 adult female volunteers (mean age 66 ± 17 years) was reviewed using 3D multiplanar reformatting to identify bone-related radiological features of osteoarthritis, namely osteophytes, subchondral cysts and joint space narrowing. Scoresheets dividing up the femoral head, head-neck region and the joint space were used to register the location and severity of each feature (scored from 0 to 3). Novel 3D cumulative feature severity maps were then created to display where the most severe disease features from each individual were anatomically located across the cohort. Feature severity maps showed a propensity for osteophytes at the inferoposterior and superolateral femoral head-neck junction. Subchondral cysts were a less common and less localised phenomenon. Joint space narrowing osteophytes and joint space narrowing for the first time. We believe this technique can perform several important roles in future osteoarthritis research, including phenotyping and sensitive disease assessment in 3D. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  17. Age-dependent Changes in the Articular Cartilage and Subchondral Bone of C57BL/6 Mice after Surgical Destabilization of Medial Meniscus.

    Science.gov (United States)

    Huang, Henry; Skelly, Jordan D; Ayers, David C; Song, Jie

    2017-02-09

    Age is the primary risk factor for osteoarthritis (OA), yet surgical OA mouse models such as destabilization of the medial meniscus (DMM) used for evaluating disease-modifying OA targets are frequently performed on young adult mice only. This study investigates how age affects cartilage and subchondral bone changes in mouse joints following DMM. DMM was performed on male C57BL/6 mice at 4 months (4 M), 12 months (12 M) and 19+ months (19 M+) and on females at 12 M and 18 M+. Two months after surgery, operated and unoperated contralateral knees were harvested and evaluated using cartilage histology scores and μCT quantification of subchondral bone plate thickness and osteophyte formation. The 12 M and 19 M+ male mice developed more cartilage erosions and thicker subchondral bone plates after DMM than 4 M males. The size of osteophytes trended up with age, while the bone volume fraction was significantly higher in the 19 M+ group. Furthermore, 12 M females developed milder OA than males as indicated by less cartilage degradation, less subchondral bone plate sclerosis and smaller osteophytes. Our results reveal distinct age/gender-dependent structural changes in joint cartilage and subchondral bone post-DMM, facilitating more thoughtful selection of murine age/gender when using this surgical technique for translational OA research.

  18. Sensitivity of radiographic features and specificity of scintigraphic imaging in hand osteoarthritis

    International Nuclear Information System (INIS)

    Buckland-Wright, J.C.; MacFarlane, D.G.; Lynch, J.A.

    1995-01-01

    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 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

  19. Age-dependent Changes in the Articular Cartilage and Subchondral Bone of C57BL/6 Mice after Surgical Destabilization of Medial Meniscus

    Science.gov (United States)

    Huang, Henry; Skelly, Jordan D.; Ayers, David C.; Song, Jie

    2017-01-01

    Age is the primary risk factor for osteoarthritis (OA), yet surgical OA mouse models such as destabilization of the medial meniscus (DMM) used for evaluating disease-modifying OA targets are frequently performed on young adult mice only. This study investigates how age affects cartilage and subchondral bone changes in mouse joints following DMM. DMM was performed on male C57BL/6 mice at 4 months (4 M), 12 months (12 M) and 19+ months (19 M+) and on females at 12 M and 18 M+. Two months after surgery, operated and unoperated contralateral knees were harvested and evaluated using cartilage histology scores and μCT quantification of subchondral bone plate thickness and osteophyte formation. The 12 M and 19 M+ male mice developed more cartilage erosions and thicker subchondral bone plates after DMM than 4 M males. The size of osteophytes trended up with age, while the bone volume fraction was significantly higher in the 19 M+ group. Furthermore, 12 M females developed milder OA than males as indicated by less cartilage degradation, less subchondral bone plate sclerosis and smaller osteophytes. Our results reveal distinct age/gender-dependent structural changes in joint cartilage and subchondral bone post-DMM, facilitating more thoughtful selection of murine age/gender when using this surgical technique for translational OA research. PMID:28181577

  20. Appearance of low signal intensity lines in MRI of silicone breast implants.

    Science.gov (United States)

    Stroman, P W; Rolland, C; Dufour, M; Grondin, P; Guidoin, R G

    1996-05-01

    Magnetic resonance (MR) images of five explanted mammary prostheses were obtained with a 1.5 T GE Signa system using a conventional spin-echo pulse sequence, in order to investigate the low-intensity curvilinear lines which may be observed in MR images of silicone gel-filled breast implants under pressure from fibrous capsules. MR images showed ellipsoid prostheses, often containing multiple low-intensity curvilinear lines which in some cases presented an appearance very similar to that of the linguine sign. Upon opening the fibrous capsules, however, all of the prostheses were found to be completely intact demonstrating that the appearance of multiple low signal intensity curvilinear lines in MR images of silicone gel-filled prostheses is not necessarily a sign of prosthesis rupture. The MR image features which are specific to the linguine sign must be more precisely defined.

  1. 3-D Imaging using Row–Column-Addressed 2-D Arrays with a Diverging Lens: Phantom Study

    DEFF Research Database (Denmark)

    Bouzari, Hamed; Engholm, Mathias; Beers, Christopher

    2017-01-01

    A double-curved diverging lens over a flat row– column-addressed (RCA) 2-D array can extend its inherent rectilinear 3-D imaging field-of-view (FOV) to a curvilinear volume region, which is necessary for applications such as abdominal and cardiac imaging. A concave lens with radius of 12.7 mm...... was manufactured using RTV664 silicone. The diverging properties of the lens were evaluated based on measurements on several phantoms. The measured 6 dB FOV in contact with a material similar to human soft tissue was less than 15% different from the theoretical predictions, i.e., a curvilinear FOV of 32...

  2. Quaternion wave equations in curved space-time

    Science.gov (United States)

    Edmonds, J. D., Jr.

    1974-01-01

    The quaternion formulation of relativistic quantum theory is extended to include curvilinear coordinates and curved space-time in order to provide a framework for a unified quantum/gravity theory. Six basic quaternion fields are identified in curved space-time, the four-vector basis quaternions are identified, and the necessary covariant derivatives are obtained. Invariant field equations are derived, and a general invertable coordinate transformation is developed. The results yield a way of writing quaternion wave equations in curvilinear coordinates and curved space-time as well as a natural framework for solving the problem of second quantization for gravity.

  3. Contribution to the study of the arterial vascularization of the testicles in donkey of the Pega race

    Directory of Open Access Journals (Sweden)

    André Luiz Quagllato Santos

    1993-12-01

    Full Text Available Estudou-se o comportamento da artéria testicular e seus ramos, bem como o número e distribuição dos vasos penetrantes, em 30 pares de testículos de jumentos da raça Pega, adultos e procedentes de várias regiões do Estado de Minas Gerais, mediante a análise de esquemas de modelos obtidos por corrosão após injeção de acetato de “vinyl”. Observou-se que nestes animais essa artéria oferece quatro arranjos vasculares diferentes, de acordo com sua divisão com predomínio de um ou outro dos vasos resultantes na irrigação do órgão. Quanto à distribuição dos vasos penetrantes, por quadrante, em mediana, faz-se de maneira que nos testículos direitos o quadrante mais povoado é o craniomedial (17.0, sendo seguido pelos quadrantes caudomedial e craniolateral (15,5 e caudolateral (15,0. Por outro lado, nos testículos esquerdos o quadrante caudolateral mostra o maior número de vasos penetrantes (18,5, seguido pelos quadrantes craniolateral (17,0, craniomedial (16,0 e caudomedial (14.0. Indentificou-se a presença de anastomoses que ocorrem entre a artéria testicular e seus ramos ou entre os diferentes colaterais cedidos pela própria artéria. Relativamente ao número total de vasos penetrantes, encontrou-se em mediana, 66,5 e 66,0 vasos para os testículos direitos e esquerdos, respectivamente, o que estatisticamente não é significante ao nível de α = 0,05, quando comparamoso número de vasos penetrantes dos testículos direitos e esquerdos.

  4. A power function profile of a ski jumping in-run hill.

    Science.gov (United States)

    Zanevskyy, Ihor

    2011-01-01

    The aim of the research was to find a function of the curvilinear segment profile which could make possible to avoid an instantaneous increasing of a curvature and to replace a circle arc segment on the in-run of a ski jump without any correction of the angles of inclination and the length of the straight-line segments. The methods of analytical geometry and trigonometry were used to calculate an optimal in-run hill profile. There were two fundamental conditions of the model: smooth borders between a curvilinear segment and straight-line segments of an in-run hill and concave of the curvilinear segment. Within the framework of this model, the problem has been solved with a reasonable precision. Four functions of a curvilinear segment profile of the in-run hill were investigated: circle arc, inclined quadratic parabola, inclined cubic parabola, and power function. The application of a power function to the in-run profile satisfies equal conditions for replacing a circle arc segment. Geometrical parameters of 38 modern ski jumps were investigated using the methods proposed.

  5. National Income, Inequality and Global Patterns of Cigarette Use

    Science.gov (United States)

    Pampel, Fred

    2007-01-01

    Declining tobacco use in high-income nations and rising tobacco use in low- and middle-income nations raises questions about the sources of worldwide patterns of smoking. Theories posit a curvilinear influence of national income based on the balance of affordability and health-cost effects. In addition, however, economic inequality, gender…

  6. Developmental Changes in Mother-Infant Face-to-Face Communication: Birth to 3 Months.

    Science.gov (United States)

    Lavelli, Manuela; Fogel, Alan

    2002-01-01

    Investigated development of face-to-face communication in infants between 1 and 14 weeks old and their mothers. Found a curvilinear development of early face-to-face communication, with increases occurring between weeks 4 and 9. When placed on a sofa, infants' face-to-face communication was longer than when they were held. Girls spent a longer…

  7. On the generalized gravi-magnetic hypothesis

    International Nuclear Information System (INIS)

    Massa, C.

    1989-01-01

    According to a generalization of the gravi-magnetic hypothesis (GMH) any neutral mass moving in a curvilinear path with respect to an inertial frame creates a magnetic field, dependent on the curvature radius of the path. A simple astrophysical consequence of the generalized GMH is suggested considering the special cases of binary pulsars and binary neutron stars

  8. Editorial: Obesity: What lies beneath? | Warshow | East African ...

    African Journals Online (AJOL)

    Obesity is a chronic disease that is associated with an excess mortality in a relationship that is best described as a "J"- shaped curve(1). As body mass index (BMI) increases, there is a curvilinear increase in mortality mostly attributable to increased deaths from heart disease(1,2), diabetes, hypertension and some forms of ...

  9. The Moderating Effects of Occupation, Age, and Urbanization on the Relationship between Job Satisfaction and Life Satsifaction.

    Science.gov (United States)

    Bamundo, Paul J.; Kopelman, Richard E.

    1980-01-01

    Education and income had a strong impact on the job satisfaction-life satisfaction relationship. Occupation had a modest effect; self-employment had a stronger one. Age and job longevity had a strong curvilinear effect. These relationships become more relevant over time. (Author/JAC)

  10. 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.…

  11. Market Earnings and Household Work: New Tests of Gender Performance Theory

    Science.gov (United States)

    Schneider, Daniel

    2011-01-01

    I examine the contested finding that men and women engage in gender performance through housework. Prior scholarship has found a curvilinear association between earnings share and housework that has been interpreted as evidence of gender performance. I reexamine these findings by conducting the first such analysis to use high-quality time diary…

  12. 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 been...

  13. 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 results...

  14. A Threshold Model of Social Support, Adjustment, and Distress after Breast Cancer Treatment

    Science.gov (United States)

    Mallinckrodt, Brent; Armer, Jane M.; Heppner, P. Paul

    2012-01-01

    This study examined a threshold model that proposes that social support exhibits a curvilinear association with adjustment and distress, such that support in excess of a critical threshold level has decreasing incremental benefits. Women diagnosed with a first occurrence of breast cancer (N = 154) completed survey measures of perceived support…

  15. Emotion and the Internet: A Model of Learning

    Science.gov (United States)

    Tran, Thuhang T.; Ward, Cheryl B.

    2005-01-01

    This conceptual paper examines the link between emotion and surface-deep learning in the context of the international business curriculum. We propose that 1) emotion and learning have a curvilinear relationship, and 2) the reflective abilities and attitude transformations related to deep-level learning can only arise if the student is emotionally…

  16. Influence of sodium chloride on shear flow induced starch-gluten separation from Soissons wheat dough

    NARCIS (Netherlands)

    Zalm, van der E.E.J.; Goot, van der A.J.; Boom, R.M.

    2010-01-01

    Wheat dough can be separated into a starch-rich and a gluten-rich fraction by subjecting the dough to curvilinear shear flow. This paper presents the effect of salt (NaCl) addition on the shear-induced separation process. The separation (defined as the changes in protein concentration in the various

  17. Small, Task-Oriented Groups: Conflict, Conflict Management, Satisfaction, and Decision Quality.

    Science.gov (United States)

    Wall, Victor D., Jr.; And Others

    1987-01-01

    Examined relationship among amount of conflict experienced, the style of its management, individual satisfaction, and decision quality of small, task-oriented groups using 129 college student subjects in 24 groups. Data suggest a curvilinear relationship between the number of conflict episodes experienced by group members and the subsequent…

  18. Genetic analysis of pre-weaning survival and inbreeding in the ...

    African Journals Online (AJOL)

    user

    2015-12-01

    Dec 1, 2015 ... early deaths of puppies. The relationship of parity with early deaths per litter can be described by a curvilinear function. The number of puppies born dead or that died at an early stage after birth increases gradually up to the fifth parity. A much steeper increase can be observed from the fifth parity onwards.

  19. Teacher Stress Predicts Child Executive Function: Moderation by School Poverty

    Science.gov (United States)

    Neuenschwander, Regula; Friedman-Krauss, Allison; Raver, Cybele; Blair, Clancy

    2017-01-01

    Research Findings: Recent research has explored relations between classroom quality and child executive function (EF), but little is known about how teachers' well-being, including stress, relates to child EF--a crucial component of self-regulation. We hypothesized that teacher stress is negatively or curvilinearly related to child EF and…

  20. Untitled

    Indian Academy of Sciences (India)

    In this case first, the linear multiple regression equation of the dependent variable (weather factors) is worked out in the form: y are G1 -- blac -- bac2 -- b3ac3 + . . . -- (2). Keywords. Curvilinear technique; graphical approximation; yield-response curve. Proc, Indian Acad. Sci. (Earth. Planet. Sci.), 108, No. 4, December 1999 ...

  1. Modern design of far-field target motion simulators

    Science.gov (United States)

    Hauser, Robin; Swamp, Michael; Havlicsek, Howard

    2006-05-01

    Target Motion Simulators (TMS) are often used in conjunction with Flight Motion Simulators (FMS) to provide a realistic simulation of tracking and target engagement. For near-field applications, the TMS has typically been implemented with two additional gimbals around the FMS. For far-field applications, such as a radar, the TMS has traditionally been implemented with curvilinear X-Y Frames. A curvilinear frame placed at the proper distance from the FMS has the benefit of always pointing the Target back to the FMS intersection of axes. In most cases the curvilinear TMS provides good results. However, the curvilinear TMS lacks the possibility to change the distance between Target and Seeker, which is needed for operation with different radar wavelengths. Acutronic has developed a new approach using a flat frame (X-Y) TMS coupled with a gimballed payload mount that has the possibility of being used at various distances without losing the functionality of continuous pointing back to the seeker. This paper describes the electro-mechanical design and gives an overview of the Computer and Controllers used. It further addresses the problem of coordination transformation that is needed to obtain the correct pointing.

  2. Plastic collapse load of crown-hinged steel circular arches : a theoretical method

    NARCIS (Netherlands)

    Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.

    2013-01-01

    For construction purposes and to avoid detrimental influences of foundation settlements arches are not always made from a single arch-rib but are built by connecting two curvilinear elements at the crown with a hinge. These arches are also known as crown-hinged arches. This paper presents an

  3. Height predicts jealousy differently for men and women

    NARCIS (Netherlands)

    Buunk, Abraham P.; Park, Justin H.; Zurriaga, Rosario; Klavina, Liga; Massar, Karlijn

    Because male height is associated with attractiveness, dominance, and reproductive success, taller men may be less jealous. And because female height has a curvilinear relationship with health and reproductive success (with average-height females having the advantages), female height may have a

  4. 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

    2013-01-01

    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 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. PMID:23754408

  5. Optimizing the duration of point counts for monitoring trends in bird populations

    Science.gov (United States)

    Jared Verner

    1988-01-01

    Minute-by-minute analysis of point counts of birds in mixed-conifer forests in the Sierra National Forest, central California, showed that cumulative counts of species and individuals increased in a curvilinear fashion but did not reach asymptotes after 10 minutes of counting. Comparison of the expected number of individuals counted per hour with various combinations...

  6. Exact solution of the neutron transport equation in spherical geometry

    Energy Technology Data Exchange (ETDEWEB)

    Anli, Fikret; Akkurt, Abdullah; Yildirim, Hueseyin; Ates, Kemal [Kahramanmaras Suetcue Imam Univ. (Turkey). Faculty of Sciences and Letters

    2017-03-15

    Solution of the neutron transport equation in one dimensional slab geometry construct a basis for the solution of neutron transport equation in a curvilinear geometry. Therefore, in this work, we attempt to derive an exact analytical benchmark solution for both neutron transport equations in slab and spherical medium by using P{sub N} approximation which is widely used in neutron transport theory.

  7. Chromatic aberrations of two-electrode transaxial mirrors

    International Nuclear Information System (INIS)

    Bejzina, L.G.; Karetskaya, S.P.

    1991-01-01

    Second order chromatic aberrations of electrostatic two-electrode transaxial mirrors in case the beam axial trajectory of charged particles is curvilinear are considered. Interrelations between coefficients of linear and angular chromatic aberrations are determined. Values of these coefficients for concave and convex transaxial mirrors with plane electrodes in dependence on potential ratio on electrodes by different onnular clearance radii are presented

  8. Hyperbolic Cosines and Sines Theorems for the Triangle Formed by Arcs of Intersecting Semicircles on Euclidean Plane

    Directory of Open Access Journals (Sweden)

    Robert M. Yamaleev

    2013-01-01

    Full Text Available The hyperbolic cosines and sines theorems for the curvilinear triangle bounded by circular arcs of three intersecting circles are formulated and proved by using the general complex calculus. The method is based on a key formula establishing a relationship between exponential function and the cross-ratio. The proofs are carried out on Euclidean plane.

  9. Spectral mimetic least-squares method for div-curl systems

    NARCIS (Netherlands)

    Gerritsma, Marc; Palha, Artur; Lirkov, I.; Margenov, S.

    2018-01-01

    In this paper the spectral mimetic least-squares method is applied to a two-dimensional div-curl system. A test problem is solved on orthogonal and curvilinear meshes and both h- and p-convergence results are presented. The resulting solutions will be pointwise divergence-free for these test

  10. Shielding container

    International Nuclear Information System (INIS)

    Darling, K.A.M.

    1981-01-01

    A shielding container incorporates a dense shield, for example of depleted uranium, cast around a tubular member of curvilinear configuration for accommodating a radiation source capsule. A lining for the tubular member, in the form of a close-coiled flexible guide, provides easy replaceability to counter wear while the container is in service. Container life is extended, and maintenance costs are reduced. (author)

  11. Investigation of Relationship between Aggression and Sociometric Popularity in Adolescents

    Science.gov (United States)

    Yavuzer, Yasemin

    2013-01-01

    In this study, it was aimed to determine the linear and curvilinear relationships between adolescent aggression and sociometric popularity. 524 adolescents randomly selected from 20 elementary schools in Nigde city center formed the study group. The participants were from 8th grade in 20 different classrooms. The research data were collected by…

  12. Mathematical modeling of turbulent stratified flows. Application of liquid metal fast breeders

    Energy Technology Data Exchange (ETDEWEB)

    Villand, M; Grand, D [CEA-Service des Transferts Thermiques, Grenoble (France)

    1983-07-01

    Mathematical model of turbulent stratified flow was proposed under the following assumptions: Newtonian fluid; incompressible fluid; coupling between temperature and momentum fields according to Boussinesq approximation; two-dimensional invariance for translation or rotation; coordinates cartesian or curvilinear. Solutions obtained by the proposed method are presented.

  13. Introduction to Electrodynamics

    Science.gov (United States)

    Griffiths, David J.

    2017-06-01

    1. Vector analysis; 2. Electrostatics; 3. Potentials; 4. Electric fields in matter; 5. Magnetostatics; 6. Magnetic fields in matter; 7. Electrodynamics; 8. Conservation laws; 9. Electromagnetic waves; 10. Potentials and fields; 11. Radiation; 12. Electrodynamics and relativity; Appendix A. Vector calculus in curvilinear coordinates; Appendix B. The Helmholtz theorem; Appendix C. Units; Index.

  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 transmission theory of electrostatic analyzer in six dimensional phase space and the concept design of a supersensitive mass spectrometer beam line for HI-13 tandem accelerator

    International Nuclear Information System (INIS)

    Guan Xialing; Cao Qingxi; Zhang Jie; Ye Jingping

    1986-01-01

    It follows from the motion equations of charged particle in curvilinear coordinates system that the transfer matrix of electrostatic analyzer was derived in six dimensional phase space. In accordance with these matrixes, the concept design of the supersensitive mass spectrometer beam line for HI-13 tandem accelerator was calculated

  16. Job Satisfaction and the Neglected Variable of Job Seniority

    Science.gov (United States)

    Ronen, Simcha

    1978-01-01

    This research investigates the hypotheses that the relationship between job seniority and job satisfaction will resemble a curvilinear function of a U-shaped curve, while age and job level will be linearly related to job satisfaction; and that intrinsic rather than extrinsic aspects of job satisfaction will be the major contributor to the U-shaped…

  17. 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…

  18. Recent advances in recreation ecology and the implications of different relationships between recreation use and ecological impacts

    Science.gov (United States)

    Christopher A. Monz; Catherine M. Pickering; Wade L. Hadwen

    2013-01-01

    Recreation ecology - the study of the environmental consequences of outdoor recreation/nature-based tourism activities and their effective management - is an emerging field of global importance. A primary research generalization in this field, the use-impact relationship, is commonly described as curvilinear, with proportionally more impact from initial recreation/...

  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,...

  20. 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…

  1. Variation in semen parameters derived from computer-aided semen analysis, within donors and between donors

    NARCIS (Netherlands)

    Wijchman, JG; De Wolf, BTHM; Graaff, R; Arts, EGJM

    2001-01-01

    The development of computer-aided semen analysis (CASA) has made it possible to study sperm motility characteristics objectively and longitudinally. In this 2-year study of 8 sperm donors, we used CASA to measure 7 semen parameters (concentration, percentage of motile spermatozoa, curvilinear

  2. New Evidence on the Development of the Word "Big."

    Science.gov (United States)

    Sena, Rhonda; Smith, Linda B.

    1990-01-01

    Results indicate that curvilinear trend in children's understanding of word "big" is not obtained in all stimulus contexts. This suggests that meaning and use of "big" is complex, and may not refer simply to larger objects in a set. Proposes that meaning of "big" constitutes a dynamic system driven by many perceptual,…

  3. Omnigenous magnetic fields

    International Nuclear Information System (INIS)

    Stupakov, G.V.

    1982-01-01

    In omnigenous magnetic fields particles' drift surfaces coincide with plasma magnetic surfaces. In this paper we formulate equations of omnigenous magnetic fields in natural curvilinear coordinates. An analysis of fields which are omnigenous only in the paraxial approximation is presented. (author)

  4. Emotionally Numb: Desensitization to Community Violence Exposure among Urban Youth

    Science.gov (United States)

    Kennedy, Traci M.; Ceballo, Rosario

    2016-01-01

    Community violence exposure (CVE) is associated with numerous psychosocial outcomes among youth. Although linear, cumulative effects models have typically been used to describe these relations, emerging evidence suggests the presence of curvilinear associations that may represent a pattern of emotional desensitization among youth exposed to…

  5. Effects of Exposure to Community Violence on Internalizing Symptoms: Does Desensitization to Violence Occur in African American Youth?

    Science.gov (United States)

    Gaylord-Harden, Noni K.; Cunningham, Jamila A.; Zelencik, Brett

    2011-01-01

    The purpose of the current study was to examine the linear and curvilinear associations of exposure to community violence to internalizing symptoms in 251 African American adolescents (mean age = 12.86, SD = 1.28). Participants reported on exposure to community violence, anxiety symptoms, and depressive symptoms. Regression analyses were used to…

  6. 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.

  7. Not All Brokers Are Alike

    DEFF Research Database (Denmark)

    Stea, Diego; Pedersen, Torben

    2017-01-01

    of brokerage, which raises important questions about when and how brokering between otherwise disconnected colleagues leads to individual creativity. We advance the relational perspective on individual creativity by adopting a contingency view, and showing that a curvilinear (inverted U-shape) specification...

  8. Biased Self-Perceptions, Peer Rejection, and Aggression in Children

    Science.gov (United States)

    White, Bradley A.; Kistner, Janet A.

    2011-01-01

    This study examined whether children's biased self-perceptions of peer acceptance are associated in a linear or curvilinear fashion with aggression, whether associations are moderated by peer rejection status, and whether associations apply uniquely to reactive aggression. Children in the 4th through 7th grades completed a self-report measure on…

  9. Is It Ethical to Condone Low Levels of Drinking in Pregnancy?

    DEFF Research Database (Denmark)

    Niclasen, Janni

    2016-01-01

    associations with a wide range of neurodevelop- mental outcomes, others have not been able to establish such associations, and even others have reported a J-shaped (i.e. curvilinear) function, suggesting that exposure to a little alcohol apparently acts as a protective factor for the developing foetus. From...

  10. Description of a new tick species, Ixodes collaris n. sp. (Acari: Ixodidae), from bats (Chiroptera: Hipposideridae, Rhinolophidae) in Vietnam.

    Science.gov (United States)

    Hornok, Sándor; Görföl, Tamás; Estók, Péter; Tu, Vuong Tan; Kontschán, Jenő

    2016-06-10

    In a recent study on ixodid bat ticks from Eurasia, a high genetic difference was found between Ixodes vespertilionis from Europe and Vietnam. Accordingly, it was proposed that I. vespertilionis is a species complex, with at least one additional, hitherto undescribed species. The aim of the present study was to investigate the morphology of bat ticks from Vietnam and to assess their taxonomic status in comparison with those collected in Europe. Ixodid bat ticks (two females and two nymphs) collected from the pomona leaf-nosed bat (Hipposideros pomona) (Hipposideridae) and intermediate horseshoe bat (Rhinolophus affinis) (Rhinolophidae) in Vietnam showed major morphological differences from European isolates of I. vespertilionis, including the shape of the scutum, the enclosure and shape of porose areas, the presence of a caudo-lateral collar-like ridge ventrally on the basis capituli, polytrich coxae with short setae, and grouped (non-linear) arrangement of anterior pit sensillae in Haller's organ. In this study the female and the nymph of an ixodid bat tick species from Vietnam are described for the first time. The genetic and morphological differences between I. vespertilionis Koch, 1844 and these bat ticks from Vietnam justify the status of the latter as a distinct species, Ixodes collaris Hornok n. sp.

  11. Tibial stress fractures in racing Standardbreds: 13 cases (1989-1993)

    International Nuclear Information System (INIS)

    Ruggles, A.J.; Moore, R.M.; Bertone, A.L.; Schneider, R.K.; Bailey, M.Q.

    1996-01-01

    To determine clinical signs, radiographic and scintigraphic findings, and performance outcome of racing Standardbreds with tibial stress fractures. Retrospective case series. 13 racing Standardbreds with tibial stress fractures. Information concerning clinical signs, diagnostic evaluation, and recommendations was obtained by review of the medical records. Performance information before and after diagnosis of the fracture was collected from racing records, and follow-up information was obtained from the owners or trainers by use of a telephone questionnaire. Horses with tibial stress fractures were moderately lame, and diagnosis was made by nuclear scintigraphy and radiography. Fractures were more likely to occur in 2-year-old horses than in older horses. The fracture location was unique for Standardbreds; 11 of 13 developed stress fractures in the mid-diaphysis of the tibia, whereas fractures in Thoroughbreds are usually in the proximal caudal or caudolateral cortex. Fractures occurred in young horses that had raced or were in advanced race training. All horses were treated with rest alone, and 10 of 13 horses raced after injury. The horses that raced after injury were able to return to a level of performance that was equal to or better than the level raced before injury. 8 of 10 horses established a lifetime-best winning time after injury. Tibial stress fractures are a cause of lameness in young racing Standardbreds. Diagnosis is aided by nuclear scintigraphy. The prognosis for return to previous level of performance after a tibial stress fracture is good

  12. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    International Nuclear Information System (INIS)

    Horng, Annie; Stockinger, M.; Notohamiprodjo, M.; Raya, J.G.; Pietschmann, M.; Hoehne-Hueckstaedt, U.; Glitsch, U.; Ellegast, R.; Hering, K.G.; Glaser, C.

    2015-01-01

    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.)

  13. Evaluation of the marsh deer stifle joint by imaging studies and gross anatomy.

    Science.gov (United States)

    Shigue, D A; Rahal, S C; Schimming, B C; Santos, R R; Vulcano, L C; Linardi, J L; Teixeira, C R

    2015-12-01

    This study aimed to evaluate the stifle joint of marsh deer using imaging studies and in comparison with gross anatomy. Ten hindlimbs from 5 marsh deer (Blastocerus dichotomus) were used. Radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed in each stifle joint. Two hindlimbs were dissected to describe stifle gross anatomy. The other limbs were sectioned in sagittal, dorsal or transverse planes. In the craniocaudal radiographic view, the lateral femoral condyle was broader than the medial femoral condyle. The femoral trochlea was asymmetrical. Subsequent multiplanar reconstruction revealed in the cranial view that the external surface of the patella was roughened, the medial trochlea ridge was larger than the lateral one, and the extensor fossa at the lateral condyle was next to the lateral ridge. The popliteal fossa was better visualized via the lateral view. Sagittal MRI images identified lateral and medial menisci, caudolateral and craniomedial bundles of cranial cruciate ligament, caudal cruciate ligament, patellar ligament and common extensor tendon. In conclusion, the marsh deer stifle presents some anatomical characteristics of the ovine stifle joint. © 2014 Blackwell Verlag GmbH.

  14. A comparison of two surgical approaches to the scapulohumeral joint in dogs.

    Science.gov (United States)

    McLaughlin, R; Roush, J K

    1995-01-01

    Two scapulohumeral arthrotomy techniques were evaluated and compared in 10 normal, young adult greyhounds. A caudolateral approach with craniodorsal retraction of the teres minor muscle (no-tenotomy) and a craniolateral approach with tenotomy of the infraspinatus tendon were each performed unilaterally in 5 dogs. The dogs were evaluated using force plate gait analysis, lameness evaluation, radiography, and goniometry for 5 weeks and then euthanatized. Tenotomy sites and sections of the humeral articular cartilage were collected from shoulder joints that had been operated on and examined microscopically. The same surgical approach has then performed on the contralateral shoulder in the cadavers and exposure of the humeral articular cartilage was measured using planimetry. Peak vertical force applied to the operated limbs in the tenotomy group was significantly less than preoperative leads on day 3 and significantly less than the no-tenotomy group on days 21 and 28. The peak vertical force applied to the operated limbs in the no-tenotomy group was not significantly different from preoperative levels during the study. Scapulohumeral arthrotomy by tenotomy of the infraspinatus resulted in decreased range-of-motion and joint extension compared with joints operated on without tenotomies, but provided significantly greater exposure to the articular surface. Scapulohumeral arthrotomy with craniodorsal retraction of the teres minor muscle did not significantly alter goniometric measurements compared with unoperated joints. Both techniques resulted in similar subjective lameness scores and caused no gross microscopic or radiographic evidence of articular cartilage damage.

  15. The ovarian and uterine arteries in the chinchilla (Chinchilla lanigera

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    A. Cevik-Demirkana

    2010-05-01

    Full Text Available The purpose of this study was to describe arteries supplying the ovaries and uterus in the chinchilla. Five healthy adult female chinchillas were used. In order to reveal the arterial network by dissecting under a stereoscopic microscope, latex coloured with red ink was injected through the common carotid artery. The ovaries of the chinchilla are supplied by the arteriae ovaricae which formed end-to-end anastomoses with the cranial termination of the arteria uterina. Soon after leaving the aorta abdominalis, the arteriae ovaricae extended 2-3mm caudolaterally, then released 1 branch and extended caudally and bifurcated into 2 further branches. One of these supplied branches to fat tissue. The other branch coursed caudally and anastomosed with the arteria circumflexa ilium profunda and dispersed into fat tissue. The arteria ovarica further subdivided into 2 rami ovaricae. The origins of the uterine arteries were exclusively from the left arteria iliaca externa. The arteria uterina gave a branch to the arteria umbilicalis and consecutive branches which supplied to the ureter, urinary bladder and cranial aspects of the vagina. It also gave rise to 2-3 branches to the cervix and further supplied 10-12 meandering branches to the uterine horns. The arteria uterina gave rise to many tortuous arteries to the uterus and provided 2 further branches to the ovary.

  16. Populations of auditory cortical neurons can accurately encode acoustic space across stimulus intensity.

    Science.gov (United States)

    Miller, Lee M; Recanzone, Gregg H

    2009-04-07

    The auditory cortex is critical for perceiving a sound's location. However, there is no topographic representation of acoustic space, and individual auditory cortical neurons are often broadly tuned to stimulus location. It thus remains unclear how acoustic space is represented in the mammalian cerebral cortex and how it could contribute to sound localization. This report tests whether the firing rates of populations of neurons in different auditory cortical fields in the macaque monkey carry sufficient information to account for horizontal sound localization ability. We applied an optimal neural decoding technique, based on maximum likelihood estimation, to populations of neurons from 6 different cortical fields encompassing core and belt areas. We found that the firing rate of neurons in the caudolateral area contain enough information to account for sound localization ability, but neurons in other tested core and belt cortical areas do not. These results provide a detailed and plausible population model of how acoustic space could be represented in the primate cerebral cortex and support a dual stream processing model of auditory cortical processing.

  17. Evaluation of the optimal plate position for the fixation of supraglenoid tubercle fractures in warmbloods.

    Science.gov (United States)

    Frei, Sina; Geyer, Hans; Hoey, Seamus; Fuerst, Anton E; Bischofberger, Andrea S

    2017-03-20

    To determine scapular cortex thickness, distal scapular bone density and describe the exact suprascapular nerve course to evaluate the best plate position for the fixation of supraglenoid tubercle fractures in horses. Twelve equine cadaveric shoulders were examined with computed tomography. Computed tomography morphometry and density measurements (Hounsfield units [HU]) of the scapula were recorded. Statistical comparisons were made between the cranial and caudal aspects of the scapula. Dissection of each shoulder was performed and the suprascapular nerve course was described morphometrically and morphologically. The suprascapular nerve was found on the periosteum and embedded in connective tissue at the cranial aspect of the scapula. It ramified proximally and distally into the supraspinatus muscle, coursed caudolaterally at a median of 2 cm (1-2 cm) distal to the scapular spine and ramified proximally and distally into the infraspinatus muscle. The scapular cortex measurements (HU) cranially were significantly larger than caudally at most levels of the scapula. The bone density of the distal scapula cranially (651.3 ± 104.2) was significantly lower than caudally (745.7 ± 179.1). For surgical access to the supraglenoid tubercle, knowledge of the anatomy is important. It is easiest to avoid the suprascapular nerve at the most cranial aspect of the scapula, where it has not yet ramified. For a stable fixation, knowledge of the characteristics of the equine scapula, such as scapular cortex thickness, is important.

  18. Astrocyte-secreted factors modulate a gradient of primary dendritic arbors in nucleus laminaris of the avian auditory brainstem.

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    Matthew J Korn

    Full Text Available Neurons in nucleus laminaris (NL receive binaural, tonotopically matched input from nucleus magnocelluaris (NM onto bitufted dendrites that display a gradient of dendritic arbor size. These features improve computation of interaural time differences, which are used to determine the locations of sound sources. The dendritic gradient emerges following a period of significant reorganization at embryonic day 15 (E15, which coincides with the emergence of astrocytes that express glial fibrillary acidic protein (GFAP in the auditory brainstem. The major changes include a loss of total dendritic length, a systematic loss of primary dendrites along the tonotopic axis, and lengthening of primary dendrites on caudolateral NL neurons. Here we have tested whether astrocyte-derived molecules contribute to these changes in dendritic morphology. We used an organotypic brainstem slice preparation to perform repeated imaging of individual dye-filled NL neurons to determine the effects of astrocyte-conditioned medium (ACM on dendritic morphology. We found that treatment with ACM induced a decrease in the number of primary dendrites in a tonotopically graded manner similar to that observed during normal development. Our data introduce a new interaction between astrocytes and neurons in the auditory brainstem and suggest that these astrocytes influence multiple aspects of auditory brainstem maturation.

  19. Anatomic Considerations on the Middle Ear in Dog

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    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.

  20. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

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    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.)

  1. Tibial nerve somatosensory evoked potentials in dogs with degenerative lumbosacral stenosis.

    Science.gov (United States)

    Meij, Björn P; Suwankong, Niyada; van den Brom, Walter E; Venker-van Haagen, Anjop J; Hazewinkel, Herman A W

    2006-02-01

    To determine somatosensory evoked potentials (SEPs) in dogs with degenerative lumbosacral stenosis (DLS) and in healthy dogs. Clinical and experimental study. Dogs with DLS (n = 21) and 11 clinically normal dogs, age, and weight matched. Under anesthesia, the tibial nerve was stimulated at the caudolateral aspect of the stifle, and lumbar SEP (LSEP) were recorded percutaneously from S1 to T13 at each interspinous space. Cortical SEP (CSEP) were recorded from the scalp. LSEP were identified as the N1-P1 (latency 3-6 ms) and N2-P2 (latency 7-13 ms) wave complexes in the recordings of dogs with DLS and control dogs. Latency of N1-P1 increased and that of N2-P2 decreased as the active recording electrode was moved cranially from S1 to T13. Compared with controls, latencies were significantly delayed in DLS dogs: .8 ms for N1-P1 and 1.7 ms for the N2-P2 complex. CSEP were not different between groups. Surface needle recording of tibial nerve SEP can be used to monitor somatosensory nerve function of pelvic limbs in dogs. In dogs with DLS, the latency of LSEP, but not of CSEP, is prolonged compared with normal dogs. In dogs with lumbosacral pain from DLS, the cauda equina compression is sufficient to affect LSEP at the lumbar level.

  2. On framing effects in decision making: linking lateral versus medial orbitofrontal cortex activation to choice outcome processing.

    Science.gov (United States)

    Windmann, Sabine; Kirsch, Peter; Mier, Daniela; Stark, Rudolf; Walter, Bertram; Güntürkün, Onur; Vaitl, Dieter

    2006-07-01

    Two correlates of outcome processing in the orbitofrontal cortex (OFC) have been proposed in the literature: One hypothesis suggests that the lateral/medial division relates to representation of outcome valence (negative vs. positive), and the other suggests that the medial OFC maintains steady stimulus-outcome associations, whereas the lateral OFC represents changing (unsteady) outcomes to prepare for response shifts. These two hypotheses were contrasted by comparing the original with the inverted version of the Iowa Gambling Task in an event-related functional magnetic resonance imaging experiment. Results showed (1) that (caudo) lateral OFC was indeed sensitive to the steadiness of the outcomes and not merely to outcome valence and (2) that the original and the inverted tasks, although both designed to measure sensitivity for future outcomes, were not equivalent as they enacted different behaviors and brain activation patterns. Results are interpreted in terms of Kahneman and Tversky's prospect theory suggesting that cognitions and decisions are biased differentially when probabilistic future rewards are weighed against consistent punishments relative to the opposite scenario [Kahneman, D., & Tversky, A. Choices, values, and frames. American Psychologist, 39, 341-350, 1984]. Specialized processing of unsteady rewards (involving caudolateral OFC) may have developed during evolution in support of goal-related thinking, prospective planning, and problem solving.

  3. Introducing a Virtual Lesion Model of Dysphagia Resulting from Pharyngeal Sensory Impairment

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    Paul Muhle

    2018-01-01

    Full Text Available Background/Aims: Performing neurophysiological and functional imaging studies in severely affected patients to investigate novel neurostimulation techniques for the treatment of neurogenic dysphagia is difficult. Therefore, basic research needs to be conducted in healthy subjects. Swallowing is a motor function highly dependent on sensory afferent input. Here we propose a virtual peripheral sensory lesion model to mimic pharyngeal sensory impairment, which is known as a major contributor to dysphagia in neurological disease. Methods: In this randomized crossover study on 11 healthy volunteers, cortical activation during pneumatic pharyngeal stimulation was measured applying magnetoencephalography in two separate sessions, with and without pharyngeal surface anesthesia. Results: Stimulation evoked bilateral event-related desynchronization (ERD mainly in the caudolateral pericentral cortex. In comparison to the no-anesthesia condition, topical anesthesia led to a reduction of ERD in beta (13-30 Hz and low gamma (30-60 Hz frequency ranges (p<0.05 in sensory but also motor cortical areas. Conclusions: Withdrawal of sensory afferent information by topical anesthesia leads to reduced response to pneumatic pharyngeal stimulation in a distributed cortical sensorimotor network in healthy subjects. The proposed paradigm may serve to investigate the effect of neuromodulatory treatments specifically on pharyngeal sensory impairment as relevant cause of neurogenic dysphagia.

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

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    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.

  5. Structural abnormalities and persistent complaints after an ankle sprain are not associated: an observational case control study in primary care.

    Science.gov (United States)

    van Ochten, John M; Mos, Marinka C E; van Putte-Katier, Nienke; Oei, Edwin H G; Bindels, Patrick J E; Bierma-Zeinstra, Sita M A; van Middelkoop, Marienke

    2014-09-01

    Persistent complaints are very common after a lateral ankle sprain. To investigate possible associations between structural abnormalities on radiography and MRI, and persistent complaints after a lateral ankle sprain. Observational case control study on primary care patients in general practice. Patients were selected who had visited their GP with an ankle sprain 6-12 months before the study; all received a standardised questionnaire, underwent a physical examination, and radiography and MRI of the ankle. Patients with and without persistent complaints were compared regarding structural abnormalities found on radiography and MRI; analyses were adjusted for age, sex, and body mass index. Of the 206 included patients, 98 had persistent complaints and 108 did not. No significant differences were found in structural abnormalities between patients with and without persistent complaints. In both groups, however, many structural abnormalities were found on radiography in the talocrural joint (47.2% osteophytes and 45.1% osteoarthritis) and the talonavicular joint (36.5% sclerosis). On MRI, a high prevalence was found of bone oedema (33.8%) and osteophytes (39.5) in the talocrural joint; osteophytes (54.4%), sclerosis (47.2%), and osteoarthritis (55.4%, Kellgren and Lawrence grade >1) in the talonavicular joint, as well as ligament damage (16.4%) in the anterior talofibular ligament. The prevalence of structural abnormalities is high on radiography and MRI in patients presenting in general practice with a previous ankle sprain. There is no difference in structural abnormalities, however, between patients with and without persistent complaints. Using imaging only will not lead to diagnosis of the explicit reason for the persistent complaint. © British Journal of General Practice 2014.

  6. Superolateral Hoffa's fat pad (SHFP) oedema and patellar cartilage volume loss: quantitative analysis using longitudinal data from the Foundation for the National Institute of Health (FNIH) Osteoarthritis Biomarkers Consortium.

    Science.gov (United States)

    Haj-Mirzaian, Arya; Guermazi, Ali; Hafezi-Nejad, Nima; Sereni, Christopher; Hakky, Michael; Hunter, David J; Zikria, Bashir; Roemer, Frank W; Demehri, Shadpour

    2018-04-12

    To determine the association of superolateral Hoffa's fat pad (SHFP) oedema and patellofemoral joint structural damage in participants of Foundation for the National Institute of Health Osteoarthritis Biomarkers Consortium study. Baseline and 24-month MRIs of 600 subjects were assessed. The presence of SHFP oedema (using 0-3 grading scale) and patellar morphology metrics were determined using baseline MRI. Quantitative patellar cartilage volume and semi-quantitative MRI osteoarthritis knee score (MOAKS) variables were extracted. The associations between SHFP oedema and patellar cartilage damage, bone marrow lesion (BML), osteophyte and morphology were evaluated in cross-sectional model. In longitudinal analysis, the associations between oedema and cartilage volume loss (defined using reliable change index) and MOAKS worsening were evaluated. In cross-sectional evaluations, the presence of SHFP oedema was associated with simultaneous lateral patellar cartilage/BML defects and inferior-medial patellar osteophyte size. A significant positive correlation between the degree of patella alta and SHFP oedema was detected (r = 0.259, p < 0.001). The presence of oedema was associated with 24-month cartilage volume loss (odds ratio (OR) 2.11, 95% confidence interval 1.46-3.06) and medial patellar BML size (OR 1.92 (1.15-3.21)) and number (OR 2.50 (1.29-4.88)) worsening. The optimal cut-off value for the grade of baseline SHFP oedema regarding both presence and worsening of patellar structural damage was ≥ 1 (presence of any SHFP hyperintensity). The presence of SHFP oedema could be considered as a predictor of future patellar cartilage loss and BML worsening, and an indicator of simultaneous cartilage, BML and osteophyte defects. • SHFP oedema was associated with simultaneous lateral patellar OA-related structural damage. • SHFP oedema was associated with longitudinal patellar cartilage loss over 24 months. • SHFP oedema could be considered as indicator and predictor

  7. Assessment of Condylar Changes in Patients with Temporomandibular Joint Pain Using Digital Volumetric Tomography

    International Nuclear Information System (INIS)

    Shetty, U.Sh.; Burde, K.N.; Naikmasur, V.G.; Sattur, A.P.

    2014-01-01

    Objective. To evaluate the efficiency of DVT in comparison with OPG in the assessment of bony condylar changes in patients of TMJ pain. Methods. 100 temporomandibular joints of 62 patients with the complaint of temporomandibular joint pain were included in the study. DVT and OPG radiographs were taken for all the 100 joints. Three observers interpreted the DVT and OPG radiograph for the bony changes separately for two times with an interval of one week. The bony changes seen in the condyle were given coding from 0 to 6. (0: Normal, 1: Erosion, 2: Flattening, 3: Osteophyte, 4: Sclerosis, 5: Resorption, and 6: other changes). Interobserver and intra observer variability was assessed with one-way Anoka statistics. Z test was used to see the significant difference between OPG and DVT. Results. In the present study the inter examiner reliability for Og and DVT was 0.903 and 0.978, respectively. Intra examiner reliability for OPG and DVT was 0.908 and 0.980, respectively. The most common condylar bony change seen in OPG and DVT was erosion followed by flattening and osteophyte. There was significant difference between OPG and DVT in detecting erosion and osteophytes. The other changes observed in our study were Elys cyst, pointed condyle, and bifid condyle. All the bony changes are more commonly seen in females than males. Conclusion. DVT provides more valid and accurate information on condylar bony changes. The DVT has an added advantage of lesser radiation exposure to the patient and cost effectiveness and could be easily accessible in a dental hospital

  8. Development and Reliability of a Preliminary Foot Osteoarthritis Magnetic Resonance Imaging Score.

    Science.gov (United States)

    Halstead, Jill; Martín-Hervás, Carmen; Hensor, Elizabeth M A; McGonagle, Dennis; Keenan, Anne-Maree; Redmond, Anthony C; Conaghan, Philip G

    2017-08-01

    Foot osteoarthritis (OA) is very common but underinvestigated musculoskeletal condition and there is little consensus as to common magnetic resonance imaging (MRI) features. The aim of this study was to develop a preliminary foot OA MRI score (FOAMRIS) and evaluate its reliability. This preliminary semiquantitative score included the hindfoot, midfoot, and metatarsophalangeal joints. Joints were scored for joint space narrowing (JSN; 0-3), osteophytes (0-3), joint effusion/synovitis, and bone cysts (present/absent). Erosions and bone marrow lesions (BML) were scored (0-3) and BML were evaluated adjacent to entheses and at sub-tendon sites (present/absent). Additionally, tenosynovitis (0-3) and midfoot ligament pathology (present/absent) were scored. Reliability was evaluated in 15 people with foot pain and MRI-detected OA using 3.0T MRI multi-sequence protocols, and assessed using ICC as an overall score and per anatomical site. Intrareader agreement (ICC) was generally good to excellent across the foot in joint features (JSN 0.90, osteophytes 0.90, effusion/synovitis 0.46, cysts 0.87), bone features (BML 0.83, erosion 0.66, BML entheses 0.66, BML sub-tendon 0.60) and soft tissue features (tenosynovitis 0.83, ligaments 0.77). Interreader agreement was lower for joint features (JSN 0.43, osteophytes 0.27, effusion/synovitis 0.02, cysts 0.48), bone features (BML 0.68, erosion 0.00, BML entheses 0.34, BML sub-tendon 0.13), and soft tissue features (tenosynovitis 0.35, ligaments 0.33). This preliminary FOAMRIS demonstrated good intrareader reliability and fair interreader reliability when assessing the total feature scores. Further development is required in cohorts with a range of pathologies and to assess the psychometric measurement properties.

  9. Cervical disc hernia operations through posterior laminoforaminotomy.

    Science.gov (United States)

    Yolas, Coskun; Ozdemir, Nuriye Guzin; Okay, Hilmi Onder; Kanat, Ayhan; Senol, Mehmet; Atci, Ibrahim Burak; Yilmaz, Hakan; Coban, Mustafa Kemal; Yuksel, Mehmet Onur; Kahraman, Umit

    2016-01-01

    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. 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. 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. Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis.

  10. 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.

  11. 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.)

  12. Increased physical activity severely induces osteoarthritic changes in knee joints with papain induced sulfate-glycosaminoglycan depleted cartilage.

    Science.gov (United States)

    Siebelt, Michiel; Groen, Harald C; Koelewijn, Stuart J; de Blois, Erik; Sandker, Marjan; Waarsing, Jan H; Müller, Cristina; van Osch, Gerjo J V M; de Jong, Marion; Weinans, Harrie

    2014-01-29

    Articular cartilage needs sulfated-glycosaminoglycans (sGAGs) to withstand high pressures while mechanically loaded. Chondrocyte sGAG synthesis is regulated by exposure to compressive forces. Moderate physical exercise is known to improve cartilage sGAG content and might protect against osteoarthritis (OA). This study investigated whether rat knee joints with sGAG depleted articular cartilage through papain injections might benefit from moderate exercise, or whether this increases the susceptibility for cartilage degeneration. sGAGs were depleted from cartilage through intraarticular papain injections in the left knee joints of 40 Wistar rats; their contralateral joints served as healthy controls. Of the 40 rats included in the study, 20 rats remained sedentary, and the other 20 were subjected to a moderately intense running protocol. Animals were longitudinally monitored for 12 weeks with in vivo micro-computed tomography (μCT) to measure subchondral bone changes and single-photon emission computed tomography (SPECT)/CT to determine synovial macrophage activation. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology to measure sGAG content and cartilage thickness. All outcome measures were unaffected by moderate exercise in healthy control joints of running animals compared with healthy control joints of sedentary animals. Papain injections in sedentary animals resulted in severe sGAG-depleted cartilage, slight loss of subchondral cortical bone, increased macrophage activation, and osteophyte formation. In running animals, papain-induced sGAG-depleted cartilage showed increased cartilage matrix degradation, sclerotic bone formation, increased macrophage activation, and more osteophyte formation. Moderate exercise enhanced OA progression in papain-injected joints and did not protect against development of the disease. This was not restricted to more-extensive cartilage damage, but also resulted in pronounced

  13. Molecular changes in articular cartilage and subchondral bone in the rat anterior cruciate ligament transection and meniscectomized models of osteoarthritis.

    Science.gov (United States)

    Pickarski, Maureen; Hayami, Tadashi; Zhuo, Ya; Duong, Le T

    2011-08-24

    Osteoarthritis (OA) is a debilitating, progressive joint disease. Similar to the disease progression in humans, sequential events of early cartilage degradation, subchondral osteopenia followed by sclerosis, and late osteophyte formation were demonstrated in the anterior cruciate ligament transection (ACLT) or ACLT with partial medial meniscectomy (ACLT + MMx) rat OA models. We describe a reliable and consistent method to examine the time dependent changes in the gene expression profiles in articular cartilage and subchondral bone. Local regulation of matrix degradation markers was demonstrated by a significant increase in mRNA levels of aggrecanase-1 and MMP-13 as early as the first week post-surgery, and expression remained elevated throughout the 10 week study. Immunohistochemistry confirmed MMP-13 expression in differentiated chondrocytes and synovial fibroblasts at week-2 and cells within osteophytes at week-10 in the surgically-modified-joints. Concomitant increases in chondrocyte differentiation markers, Col IIA and Sox 9, and vascular invasion markers, VEGF and CD31, peaked around week-2 to -4, and returned to Sham levels at later time points in both models. Indeed, VEGF-positive cells were found in the deep articular chondrocytes adjacent to subchondral bone. Osteoclastic bone resorption markers, cathepsin K and TRAP, were also elevated at week-2. Confirming bone resorption is an early local event in OA progression, cathepsin K positive osteoclasts were found invading the articular cartilage from the subchondral region at week 2. This was followed by late disease events, including subchondral sclerosis and osteophyte formation, as demonstrated by the upregulation of the osteoanabolic markers runx2 and osterix, toward week-4 to 6 post-surgery. In summary, this study demonstrated the temporal and cohesive gene expression changes in articular cartilage and subchondral bone using known markers of OA progression. The findings here support genome-wide profiling

  14. Inhibition of Notch1 promotes hedgehog signalling in a HES1-dependent manner in chondrocytes and exacerbates experimental osteoarthritis.

    Science.gov (United States)

    Lin, Neng-Yu; Distler, Alfiya; Beyer, Christian; Philipi-Schöbinger, Ariella; Breda, Silvia; Dees, Clara; Stock, Michael; Tomcik, Michal; Niemeier, Andreas; Dell'Accio, Francesco; Gelse, Kolja; Mattson, Mark P; Schett, Georg; Distler, Jörg Hw

    2016-11-01

    Notch ligands and receptors have recently been shown to be differentially expressed in osteoarthritis (OA). We aim to further elucidate the functional role of Notch signalling in OA using Notch1 antisense transgenic (Notch1 AS) mice. Notch and hedgehog signalling were analysed by real-time PCR and immunohistochemistry. Notch-1 AS mice were employed as a model of impaired Notch signalling in vivo. Experimental OA was induced by destabilisation of the medial meniscus (DMM). The extent of cartilage destruction and osteophyte formation was analysed by safranin-O staining with subsequent assessment of the Osteoarthritis Research Society International (OARSI) and Mankin scores and µCT scanning. Collagen X staining was used as a marker of chondrocyte hypertrophy. The role of hairy/enhancer of split 1 (Hes-1) was investigated with knockdown and overexpression experiments. Notch signalling was activated in human and murine OA with increased expression of Jagged1, Notch-1, accumulation of the Notch intracellular domain 1 and increased transcription of Hes-1. Notch1 AS mice showed exacerbated OA with increases in OARSI scores, osteophyte formation, increased subchondral bone plate density, collagen X and osteocalcin expression and elevated levels of Epas1 and ADAM-TS5 mRNA. Inhibition of the Notch pathway induced activation of hedgehog signalling with induction of Gli-1 and Gli-2 and increased transcription of hedgehog target genes. The regulatory effects of Notch signalling on Gli-expression were mimicked by Hes-1. Inhibition of Notch signalling activates hedgehog signalling, enhances chondrocyte hypertrophy and exacerbates experimental OA including osteophyte formation. These data suggest that the activation of the Notch pathway may limit aberrant hedgehog signalling in OA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  15. Molecular changes in articular cartilage and subchondral bone in the rat anterior cruciate ligament transection and meniscectomized models of osteoarthritis

    Directory of Open Access Journals (Sweden)

    Zhuo Ya

    2011-08-01

    Full Text Available Abstract Background Osteoarthritis (OA is a debilitating, progressive joint disease. Methods Similar to the disease progression in humans, sequential events of early cartilage degradation, subchondral osteopenia followed by sclerosis, and late osteophyte formation were demonstrated in the anterior cruciate ligament transection (ACLT or ACLT with partial medial meniscectomy (ACLT + MMx rat OA models. We describe a reliable and consistent method to examine the time dependent changes in the gene expression profiles in articular cartilage and subchondral bone. Results Local regulation of matrix degradation markers was demonstrated by a significant increase in mRNA levels of aggrecanase-1 and MMP-13 as early as the first week post-surgery, and expression remained elevated throughout the 10 week study. Immunohistochemistry confirmed MMP-13 expression in differentiated chondrocytes and synovial fibroblasts at week-2 and cells within osteophytes at week-10 in the surgically-modified-joints. Concomitant increases in chondrocyte differentiation markers, Col IIA and Sox 9, and vascular invasion markers, VEGF and CD31, peaked around week-2 to -4, and returned to Sham levels at later time points in both models. Indeed, VEGF-positive cells were found in the deep articular chondrocytes adjacent to subchondral bone. Osteoclastic bone resorption markers, cathepsin K and TRAP, were also elevated at week-2. Confirming bone resorption is an early local event in OA progression, cathepsin K positive osteoclasts were found invading the articular cartilage from the subchondral region at week 2. This was followed by late disease events, including subchondral sclerosis and osteophyte formation, as demonstrated by the upregulation of the osteoanabolic markers runx2 and osterix, toward week-4 to 6 post-surgery. Conclusions In summary, this study demonstrated the temporal and cohesive gene expression changes in articular cartilage and subchondral bone using known markers of

  16. Development and reliability of a multi-modality scoring system for evaluation of disease progression in pre-clinical models of osteoarthritis: celecoxib may possess disease-modifying properties.

    Science.gov (United States)

    Panahifar, A; Jaremko, J L; Tessier, A G; Lambert, R G; Maksymowych, W P; Fallone, B G; Doschak, M R

    2014-10-01

    We sought to develop a comprehensive scoring system for evaluation of pre-clinical models of osteoarthritis (OA) progression, and use this to evaluate two different classes of drugs for management of OA. Post-traumatic OA (PTOA) was surgically induced in skeletally mature rats. Rats were randomly divided in three groups receiving either glucosamine (high dose of 192 mg/kg) or celecoxib (clinical dose) or no treatment. Disease progression was monitored utilizing micro-magnetic resonance imaging (MRI), micro-computed tomography (CT) and histology. Pertinent features such as osteophytes, subchondral sclerosis, joint effusion, bone marrow lesion (BML), cysts, loose bodies and cartilage abnormalities were included in designing a sensitive multi-modality based scoring system, termed the rat arthritis knee scoring system (RAKSS). Overall, an inter-observer correlation coefficient (ICC) of greater than 0.750 was achieved for each scored feature. None of the treatments prevented cartilage loss, synovitis, joint effusion, or sclerosis. However, celecoxib significantly reduced osteophyte development compared to placebo. Although signs of inflammation such as synovitis and joint effusion were readily identified at 4 weeks post-operation, we did not detect any BML. We report the development of a sensitive and reliable multi-modality scoring system, the RAKSS, for evaluation of OA severity in pre-clinical animal models. Using this scoring system, we found that celecoxib prevented enlargement of osteophytes in this animal model of PTOA, and thus it may be useful in preventing OA progression. However, it did not show any chondroprotective effect using the recommended dose. In contrast, high dose glucosamine had no measurable effects. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  17. Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography.

    Science.gov (United States)

    Turmezei, Tom D; Treece, Graham M; Gee, Andrew H; Fotiadou, Anastasia F; Poole, Kenneth E S

    2016-07-01

    To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data. Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K&L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data. For each increase in K&L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head-neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head-neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW. These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis. • CT is being increasingly used to assess bony involvement in osteoarthritis • CBM provides accurate and reliable quantitative analysis of cortical bone thickness • Cortical bone is thicker at the superior femoral head-neck with worse osteoarthritis • Regions of increased thickness co-locate with impingement and osteophyte formation • Quantitative 3D bone analysis could enable clinical disease prediction and therapy development.

  18. Characterization of articular cartilage and subchondral bone changes in the rat anterior cruciate ligament transection and meniscectomized models of osteoarthritis.

    Science.gov (United States)

    Hayami, Tadashi; Pickarski, Maureen; Zhuo, Ya; Wesolowski, Gregg A; Rodan, Gideon A; Duong, Le T

    2006-02-01

    Osteoarthritis (OA) is a chronic joint disease characterized by cartilage destruction, subchondral bone sclerosis, and osteophyte formation. Subchondral bone stiffness has been proposed to initiate and/or contribute to cartilage deterioration in OA. The purpose of this study was to characterize subchondral bone remodeling, cartilage damage, and osteophytosis during the disease progression in two models of surgically induced OA. Rat knee joints were subjected either to anterior cruciate ligament transection (ACLT) alone or in combination with resection of medial menisci (ACLT + MMx). Histopathological changes in the surgical joints were compared with sham at 1, 2, 4, 6, and 10 weeks post-surgery. Using a modified Mankin scoring system, we demonstrate that articular cartilage damage occurs within 2 weeks post-surgery in both surgical models. Detectable cartilage surface damage and proteoglycan loss were observed as early as 1 week post-surgery. These were followed by the increases in vascular invasion into cartilage, in loss of chondrocyte number and in cell clustering. Histomorphometric analysis revealed subchondral bone loss in both models within 2 weeks post-surgery followed by significant increases in subchondral bone volume relative to sham up to 10 weeks post-surgery. Incidence of osteophyte formation was optimally observed in ACLT joints at 10 weeks and in ACLT + MMx joints at 6 weeks post-surgery. In summary, the two surgically induced rat OA models share many characteristics seen in human and other animal models of OA, including progressive articular cartilage degradation, subchondral bone sclerosis, and osteophyte formation. Moreover, increased subchondral bone resorption is associated with early development of cartilage lesions, which precedes significant cartilage thinning and subchondral bone sclerosis. Together, these findings support a role for bone remodeling in OA pathogenesis and suggest that these rat models are suitable for evaluating bone

  19. Histopathological subgroups in knee osteoarthritis.

    Science.gov (United States)

    Wyatt, L A; Moreton, B J; Mapp, P I; Wilson, D; Hill, R; Ferguson, E; Scammell, B E; Walsh, D A

    2017-01-01

    Osteoarthritis (OA) is a heterogeneous, multi-tissue disease. We hypothesised that different histopathological features characterise different stages during knee OA progression, and that discrete subgroups can be defined based on validated measures of OA histopathological features. Medial tibial plateaux and synovium were from 343 post-mortem (PM) and 143 OA arthroplasty donations. A 'chondropathy/osteophyte' group (n = 217) was classified as PM cases with osteophytes or macroscopic medial tibiofemoral chondropathy lesions ≥grade 3 to represent pre-surgical (early) OA. 'Non-arthritic' controls (n = 48) were identified from the remaining PM cases. Mankin histopathological scores were subjected to Rasch analysis and supplemented with histopathological scores for subchondral bone marrow replacement and synovitis. Item weightings were derived by principle components analysis (PCA). Histopathological subgroups were sought using latent class analysis (LCA). Chondropathy, synovitis and osteochondral pathology were each associated with OA at arthroplasty, but each was also identified in some 'non-arthritic' controls. Tidemark breaching in the chondropathy/osteophyte group was greater than in non-arthritic controls. Three histopathological subgroups were identified, characterised as 'mild OA', or 'severe OA' with mild or moderate/severe synovitis. Presence and severity of synovitis helps define distinct histopathological OA subgroups. The absence of a discrete 'normal' subgroup indicates a pathological continuum between normality and OA status. Identifying specific pathological processes and their clinical correlates in OA subgroups has potential to accelerate the development of more effective therapies. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  20. Presence, location, type and size of denuded areas of subchondral bone in the knee as a function of radiographic stage of OA - data from the OA initiative.

    Science.gov (United States)

    Frobell, R B; Wirth, W; Nevitt, M; Wyman, B T; Benichou, O; Dreher, D; Davies, R Y; Lee, J H; Baribaud, F; Gimona, A; Hudelmaier, M; Cotofana, S; Eckstein, F

    2010-05-01

    To assess the presence, location, type and size of denuded areas of subchondral bone (dAB) in the femorotibial joint, measured quantitatively with 3T MRI, in a large subset of OAI participants. One knee of 633 subjects (250 men, 383 women, aged 61.7+/-9.6 y) were studied, spanning all radiographic osteoarthritis (OA) stages. dABs were determined quantitatively using segmentations of coronal FLASHwe images, representing areas where the subchondral bone was not covered by cartilage. Post hoc visual examination of segmented images determined whether dABs represented full thickness cartilage loss or internal osteophyte. 7% Of the knees were Kellgren & Lawrence (KL) grade 0, 6% grade 1, 41% grade 2, 41% grade 3, and 5% grade 4. 39% Of the participants (48% of the men and 33% of the women) displayed dABs; 61% of the dABs represented internal osteophytes. 1/47 Participants with KL grade 0 displayed 'any' dAB whereas 29/32 of the KL grade 4 knees were affected. Even as early as KL grade 1, 29% of the participants showed dABs. There were significant relationships of dAB with increasing KL grades (Posteophytes were more frequent laterally (mainly posterior tibia and internal femur) whereas full thickness cartilage loss was more frequent medially (mainly external tibia and femur). dABs occur already at earliest stages of radiographic OA (KL grades 1 and 2) and become more common (and larger) with increasing disease severity. Almost all KL grade 4 knees exhibited dABs, with cartilage loss being more frequent than internal osteophytes. Copyright 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  1. Inhibition of cathepsin K reduces cartilage degeneration in the anterior cruciate ligament transection rabbit and murine models of osteoarthritis.

    Science.gov (United States)

    Hayami, Tadashi; Zhuo, Ya; Wesolowski, Gregg A; Pickarski, Maureen; Duong, Le T

    2012-06-01

    To investigate the disease modifying effects of cathepsin K (CatK) inhibitor L-006235 compared to alendronate (ALN) in two preclinical models of osteoarthritis (OA). Skeletally mature rabbits underwent sham or anterior cruciate ligament transection (ACLT)-surgery and were treated with L-006235 (L-235, 10 mg/kg or 50 mg/kg, p.o., daily) or ALN (0.6 mg/kg, s.c., weekly) for 8-weeks. ACLT joint instability was also induced in CatK(-/-) versus wild type (wt) mice and treated for 16-weeks. Changes in cartilage degeneration, subchondral bone volume and osteophyte area were determined by histology and μ-CT. Collagen type I helical peptide (HP-I), a bone resorption marker and collagen type II C-telopeptide (CTX-II), a cartilage degradation marker were measured. L-235 (50 mg/kg) and ALN treatment resulted in significant chondroprotective effects, reducing CTX-II by 60% and the histological Mankin score for cartilage damage by 46% in the ACLT-rabbits. Both doses of L-235 were more potent than ALN in protecting against focal subchondral bone loss, and reducing HP-I by 70% compared to vehicle. L-235 (50 mg/kg) and ALN significantly reduced osteophyte formation in histomorphometric analysis by 55%. The Mankin score in ACLT-CatK(-/-) mice was ~2.5-fold lower than the ACLT-wt mice and was not different from sham-CatK(-/-). Osteophyte development was not different among the groups. Inhibition of CatK provides significant benefits in ACLT-model of OA, including: 1) protection of subchondral bone integrity, 2) protection against cartilage degradation and 3) reduced osteophytosis. Preclinical evidence supports the role of CatK as a potential therapeutic target for the treatment of OA. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Increased physical activity severely induces osteoarthritic changes in knee joints with papain induced sulfate-glycosaminoglycan depleted cartilage

    Science.gov (United States)

    2014-01-01

    Introduction Articular cartilage needs sulfated-glycosaminoglycans (sGAGs) to withstand high pressures while mechanically loaded. Chondrocyte sGAG synthesis is regulated by exposure to compressive forces. Moderate physical exercise is known to improve cartilage sGAG content and might protect against osteoarthritis (OA). This study investigated whether rat knee joints with sGAG depleted articular cartilage through papain injections might benefit from moderate exercise, or whether this increases the susceptibility for cartilage degeneration. Methods sGAGs were depleted from cartilage through intraarticular papain injections in the left knee joints of 40 Wistar rats; their contralateral joints served as healthy controls. Of the 40 rats included in the study, 20 rats remained sedentary, and the other 20 were subjected to a moderately intense running protocol. Animals were longitudinally monitored for 12 weeks with in vivo micro-computed tomography (μCT) to measure subchondral bone changes and single-photon emission computed tomography (SPECT)/CT to determine synovial macrophage activation. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology to measure sGAG content and cartilage thickness. Results All outcome measures were unaffected by moderate exercise in healthy control joints of running animals compared with healthy control joints of sedentary animals. Papain injections in sedentary animals resulted in severe sGAG-depleted cartilage, slight loss of subchondral cortical bone, increased macrophage activation, and osteophyte formation. In running animals, papain-induced sGAG-depleted cartilage showed increased cartilage matrix degradation, sclerotic bone formation, increased macrophage activation, and more osteophyte formation. Conclusions Moderate exercise enhanced OA progression in papain-injected joints and did not protect against development of the disease. This was not restricted to more-extensive cartilage

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

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    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

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

    International Nuclear Information System (INIS)

    Kovacs, F.M.; Royuela, A.; Jensen, T.S.

    2009-01-01

    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 research

  5. 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.

  6. Assessment of Condylar Changes in Patients with Temporomandibular Joint Pain Using Digital Volumetric Tomography

    Directory of Open Access Journals (Sweden)

    Ujwala Shivarama Shetty

    2014-01-01

    Full Text Available Objective. To evaluate the efficiency of DVT in comparison with OPG in the assessment of bony condylar changes in patients of TMJ pain. Methods. 100 temporomandibular joints of 62 patients with the complaint of temporomandibular joint pain were included in the study. DVT and OPG radiographs were taken for all the 100 joints. Three observers interpreted the DVT and OPG radiograph for the bony changes separately for two times with an interval of one week. The bony changes seen in the condyle were given coding from 0 to 6. (0: Normal, 1: Erosion, 2: Flattening, 3: Osteophyte, 4: Sclerosis, 5: Resorption, and 6: other changes. Interobserver and intraobserver variability was assessed with one-way ANOVA statistics. Z test was used to see the significant difference between OPG and DVT. Results. In the present study the interexaminer reliability for OPG and DVT was 0.903 and 0.978, respectively. Intraexaminer reliability for OPG and DVT was 0.908 and 0.980, respectively. The most common condylar bony change seen in OPG and DVT was erosion followed by flattening and osteophyte. There was significant difference between OPG and DVT in detecting erosion and osteophytes. The other changes observed in our study were Ely’s cyst, pointed condyle, and bifid condyle. All the bony changes are more commonly seen in females than males. Conclusion. DVT provides more valid and accurate information on condylar bony changes. The DVT has an added advantage of lesser radiation exposure to the patient and cost effectiveness and could be easily accessible in a dental hospital.

  7. Myelography in achondroplasia: value of a lateral C1-2 puncture and non-ionic, water-soluble contrast medium

    International Nuclear Information System (INIS)

    Suss, R.A.; Udvarhelyi, G.B.; Wang, H.; Kumar, A.J.; Zinreich, S.J.; Rosenbaum, A.E.

    1983-01-01

    Because of technical difficulties and diagnostic limitations encountered with other myelographic techniques in patients with achondroplasia, the authors employed a lateral C1-2 puncture and non-ionic, water-soluble contrast medium in 18 achondroplastic patients with spinal compression (21 procedures). This technique proved most appropriate for identifying the upper limit of degenerative osteophytes causing exacerbation of congenital spinal stenosis, which is crucial in planning decompressive surgery. A potentially important additional finding was the presence of degenerative lower cervical spine disease in the majority of patients. There were no serious complications. The authors recommend this technique as safe and effective in achondroplastic patients with severe congenital spinal stenosis

  8. Radiographic Assessment of the Robert and Lateral Views in Trapeziometacarpal Osteoarthrosis.

    Science.gov (United States)

    Oheb, Jonathan; Lansinger, Yuri; Jansen, Joshua A; Nguyen, Jimmy Q; Porembski, Margaret A; Rayan, Ghazi M

    2015-01-01

    To evaluate the effectiveness of the Robert view in assessing trapeziometacarpal arthrosis and to compare the accuracy of the Robert and lateral views in staging trapeziometacarpal (TM) joint arthrosis. Patient demographics were obtained. Four participating raters reviewed 62 randomly selected thumb x-rays of patients presenting with thumb TM joint pain. Lateral and Robert-hyperpronation views were assessed using an analysis of 13 criteria. X-rays of 62 thumbs for 58 patients were evaluated. The average patients' age was 64 (47-87) and 51 (80%) were females. The majority of X-rays evaluated fell into stage 3. Stage 2 was the second most common level of arthritis encountered and the least was stage 1. More osteophytes were encountered in the trapezium than metacarpal on both the Robert and lateral views. The Robert view was superior in detecting osteophytes on the trapezium than the lateral view. Osteophyte size varied from 1.7 to 2 mm. The lateral view displayed 61 cases with dorsal metacarpal subluxation (98%). The Robert view displayed 48 cases (77%) with radial metacarpal subluxation and 9 cases (15%) with ulnar metacarpal subluxation. Thumb metacarpal adduction deformity was encountered on the lateral view in 20 cases (32%) whereas on the Robert view it was encountered in 14 cases (23%). Subchondral sclerosis was encountered on the Robert view in 56 thumbs (90%) while it was seen on the lateral view in 52 thumbs (84%). Pantrapezial arthritis involving the STT joint was encountered equally in 16 cases (26%) on the Robert view and the lateral views. The study found a moderate level of interrater reliability on both the lateral and Robert views. With the exception of osteophytes encountered on the trapezium versus the metacarpal, there were no other statistically significant findings. This study confirms that each of the Robert and lateral views offer unique information and combining both views enhances the ability to assess radiographic disease severity, and

  9. Radiographic and magnetic resonance imaging of the stifle joint in experimental osteoarthritis of dogs

    International Nuclear Information System (INIS)

    Widmer, W.R.; Buckwalter, K.A.; Braunstein, E.M.; Hill, M.A.; O'Connor, B.L.; Visco, D.M.

    1994-01-01

    Radiography and magnetic resonance imaging were used to evaluate osteoarthritis at 2, 6, and 12 weeks following transection of the cranial cruciate ligament of the stifle (femorotibial) joint of 6 dogs. A quantitative radiographic scoring system was used to assess the progression of hard and soft tissue changes of osteoarthritis. Mediolateral (flexed joint) and oblique (extended joint) radiographic projections enabled identification of small osteophytes on the femoral trochlear ridges, which were detected at an earlier stage of development than was previously reported. Magnetic resonance imaging was useful in detecting changes in cartilage thickness, osteophytosis and intraarticular loose bodies. Radiography and magnetic resonance imaging were complementary in the assessment of pathologic changes of osteoarthritis

  10. Triamcinolone acetonide activates an anti-inflammatory and folate receptor-positive macrophage that prevents osteophytosis in vivo.

    Science.gov (United States)

    Siebelt, Michiel; Korthagen, Nicoline; Wei, Wu; Groen, Harald; Bastiaansen-Jenniskens, Yvonne; Müller, Christina; Waarsing, Jan Hendrik; de Jong, Marion; Weinans, Harrie

    2015-12-05

    Triamcinolone acetonide (TA) is used for osteoarthritis management to reduce pain, and pre-clinical studies have shown that TA limits osteophyte formation. Osteophyte formation is known to be facilitated by synovial macrophage activation. TA injections might influence macrophage activation and subsequently reduce osteophytosis. Although widely applied in clinical care, the mechanism through which TA exerts this effect remains unknown. In this animal study, we investigated the in vivo effects of TA injections on macrophage activation, osteophyte development and joint degeneration. Furthermore, in vitro macrophage differentiation experiments were conducted to further explain working mechanisms of TA effects found in vivo. Osteoarthritis was induced in rat knees using papain injections and a running protocol. Untreated and TA-treated animals were longitudinally monitored for 12 weeks with in vivo micro-computed tomography (μCT) to measure subchondral bone changes. Synovial macrophage activation was measured in vivo using folate receptor β (FRβ)-targeted single-photon emission computed tomography/computed tomography. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology. To further explain the outcomes of our in vivo study, TA on macrophages was also studied in vitro. These cultured macrophages were either M1- or M2-activated, and they were analyzed using fluorescence-activated cell sorting for CD163 and FRβ expression as well as for messenger RNA (mRNA) expression of interleukin (IL)-10. Our in vivo study showed that intra-articular injections with TA strongly enhanced FRβ(+) macrophage activation. Despite stimulated macrophage activation, osteophyte formation was fully prevented. There was no beneficial effect of TA against cartilage degradation or subchondral bone sclerosis. In vitro macrophage cultures showed that TA strongly induced monocyte differentiation towards CD163(+) and FRβ(+) macrophages. Furthermore

  11. Experimental osteoarthritis in the rabbit knee joint

    International Nuclear Information System (INIS)

    Bohr, H.

    1976-01-01

    development of arthrotic-like changes following resection of the of the cruciate ligaments in the knee joint of rabbits has been studied at intervals from 2 weeks to 10 months in 35 animals. Signs of cartilage degeneration were followed by changes in the subchondral bone, where formation of osteophytes and condensation to took place. An increased vascular supply was demonstrated by microangiographic and scintigraphic investigations. The uptake of 18 F and 99 mTc-polyphosphate reached a maximal value about 2 months after the operation and then diminished despite further development of arthrotic changes. (author)

  12. Effect of alendronate on post-traumatic osteoarthritis induced by anterior cruciate ligament rupture in mice.

    Science.gov (United States)

    Khorasani, Mohammad S; Diko, Sindi; Hsia, Allison W; Anderson, Matthew J; Genetos, Damian C; Haudenschild, Dominik R; Christiansen, Blaine A

    2015-02-16

    Previous studies in animal models of osteoarthritis suggest that alendronate (ALN) has antiresorptive and chondroprotective effects, and can reduce osteophyte formation. However, these studies used non-physiologic injury methods, and did not investigate early time points during which bone is rapidly remodeled prior to cartilage degeneration. The current study utilized a non-invasive model of knee injury in mice to investigate the effect of ALN treatment on subchondral bone changes, articular cartilage degeneration, and osteophyte formation following injury. Non-invasive knee injury via tibial compression overload or sham injury was performed on a total of 90 mice. Mice were treated with twice weekly subcutaneous injections of low-dose ALN (40 μg/kg/dose), high-dose ALN (1,000 μg/kg/dose), or vehicle, starting immediately after injury until sacrifice at 7, 14 or 56 days. Trabecular bone of the femoral epiphysis, subchondral cortical bone, and osteophyte volume were quantified using micro-computed tomography (μCT). Whole-joint histology was performed at all time points to analyze articular cartilage and joint degeneration. Blood was collected at sacrifice, and serum was analyzed for biomarkers of bone formation and resorption. μCT analysis revealed significant loss of trabecular bone from the femoral epiphysis 7 and 14 days post-injury, which was effectively prevented by high-dose ALN treatment. High-dose ALN treatment was also able to reduce subchondral bone thickening 56 days post-injury, and was able to partially preserve articular cartilage 14 days post-injury. However, ALN treatment was not able to reduce osteophyte formation at 56 days post-injury, nor was it able to prevent articular cartilage and joint degeneration at this time point. Analysis of serum biomarkers revealed an increase in bone resorption at 7 and 14 days post-injury, with no change in bone formation at any time points. High-dose ALN treatment was able to prevent early trabecular

  13. New developments in osteoarthritis and cartilage biology.

    Science.gov (United States)

    Poulet, Blandine; Staines, Katherine A

    2016-06-01

    Osteoarthritis (OA) is a degenerative joint disease and the most common form of arthritis. Characterised by articular cartilage loss, subchondral bone thickening and osteophyte formation, the OA joint afflicts much pain and disability. Whilst OA has been associated with many contributing factors, its underpinning molecular mechanisms are, nevertheless, not fully understood. Clinical management of OA is largely palliative and there is an ever growing need for an effective disease modifying treatment. This review discusses some of the recent progress in OA therapies in the different joint tissues affected by OA pathology. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Development and Reliability of the OMERACT Thumb Base Osteoarthritis Magnetic Resonance Imaging Scoring System

    DEFF Research Database (Denmark)

    Kroon, Féline P B; Conaghan, Philip G; Foltz, Violaine

    2017-01-01

    : The TOMS assessed the first carpometacarpal (CMC-1) and scaphotrapeziotrapezoid (STT) joints for synovitis, subchondral bone defects (including erosions, cysts, and bone attrition), osteophytes, cartilage, and bone marrow lesions on a 0-3 scale (normal to severe). Subluxation was evaluated only in the CMC......, with better performance for subchondral bone defects, subluxation, and bone marrow lesions. CONCLUSION: A thumb base OA MRI scoring system has been developed. The OMERACT TOMS demonstrated good intrareader and interreader reliability. Longitudinal studies are warranted to investigate reliability of change...

  15. Radiographic changes in the condyle of the temporomandibular joint in psoriatic arthritis

    International Nuclear Information System (INIS)

    Koenoenen, M.; Helsinki Univ.

    1987-01-01

    One hundred and ten patients with psoriatic arthritis (PA) and 100 matched control patients were examined by using orthopantomography to discover radiographic changes in the condyle of the temporomandibular joint (TMJ). 31% of the PA patients and 13% of the control patients had radiographic changes in the condyle of the TMJ. The most common radiographic finding in PA patients was unilateral erosion of the condyle. Of the radiographic changes in the PA group, cortical erosions correlated negatively with age, whereas osteophytes correlated positively with the duration of PA. (orig.)

  16. Sequential radionuclide bone imaging in avascular pediatric hip conditions

    International Nuclear Information System (INIS)

    Minikel, J.; Sty, J.; Simons, G.

    1983-01-01

    Radionuclide bone imaging was performed on six patients with various hip conditions. Initial bone images revealed diminished uptake of isotope /sup 99m/Tc-MDP in the capital femoral epiphysis. Following therapeutic intervention, repeat bone scans revealed normal uptake of /sup 99m/Tc-MDP in the capital femoral epiphysis. Subsequent radiographs revealed that avascular necrosis had not occurred. There are two types of avascularity: the potentially reversible, and the irreversible. Attempts should be made toward early recognition of the potentially reversible avascular insult. With early recognition, surgical reconstruction prior to osteophyte death may result in revascularization. If this can be accomplished, avascular necrosis can be avoided

  17. 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.

  18. Shoulder impingement syndrome: diagnostic accuracy of magnetic resonance imaging and radiographic signs

    International Nuclear Information System (INIS)

    Williamson, M.P.; Chandnani, V.P.; Baird, D.E.; Deberardino, T.M.; Swenson, G.W.; Hansen, M.F.

    1994-01-01

    Shoulder impingement syndrome is commonly encountered in orthopaedics. In a blinded retrospective study, magnetic resonance imaging and roentgenographic signs in 41 patients with clinical signs of impingement syndrome were compared with 40 control patients. Statistically significant differences between the groups included the absence of subacromial fat, as well as the presence of a supraspinatus tear, subacromial osteophytes, and a decreased coracohumeral distance. Other signs reported to occur in patients with impingement syndrome did not vary significantly in the population studied. 20 refs., 12 figs

  19. Roentgenographic findings following anterior cervical fusion

    Energy Technology Data Exchange (ETDEWEB)

    Gore, D R; Gardner, G M; Sepic, S B; Murray, M P

    1986-10-01

    We reviewed the pre- and postoperative lateral cervical roentgenograms in 90 patients who had anterior fusions and compared their findings with age and sex-matched people without neck problems. The average interval from surgery to review was 5 years. Preoperatively, all patients had a higher incidence of degenerative spondylosis at the levels to be fused than their asymptomatic counterparts. Postoperatively, there was no difference in the incidence of degenerative change between the operated and the control group at the levels above and below the fusion with the exception of anterior osteophyte formation which was more frequent in those with fusions.

  20. PEDF Is Associated with the Termination of Chondrocyte Phenotype and Catabolism of Cartilage Tissue.

    Science.gov (United States)

    Klinger, P; Lukassen, S; Ferrazzi, F; Ekici, A B; Hotfiel, T; Swoboda, B; Aigner, T; Gelse, K

    2017-01-01

    Objective. To investigate the expression and target genes of pigment epithelium-derived factor (PEDF) in cartilage and chondrocytes, respectively. Methods. We analyzed the expression pattern of PEDF in different human cartilaginous tissues including articular cartilage, osteophytic cartilage, and fetal epiphyseal and growth plate cartilage, by immunohistochemistry and quantitative real-time (qRT) PCR. Transcriptome analysis after stimulation of human articular chondrocytes with rhPEDF was performed by RNA sequencing (RNA-Seq) and confirmed by qRT-PCR. Results. Immunohistochemically, PEDF could be detected in transient cartilaginous tissue that is prone to undergo endochondral ossification, including epiphyseal cartilage, growth plate cartilage, and osteophytic cartilage. In contrast, PEDF was hardly detected in healthy articular cartilage and in the superficial zone of epiphyses, regions that are characterized by a permanent stable chondrocyte phenotype. RNA-Seq analysis and qRT-PCR demonstrated that rhPEDF significantly induced the expression of a number of matrix-degrading factors including SAA1, MMP1, MMP3, and MMP13. Simultaneously, a number of cartilage-specific genes including COL2A1, COL9A2, COMP, and LECT were among the most significantly downregulated genes. Conclusions. PEDF represents a marker for transient cartilage during all neonatal and postnatal developmental stages and promotes the termination of cartilage tissue by upregulation of matrix-degrading factors and downregulation of cartilage-specific genes. These data provide the basis for novel strategies to stabilize the phenotype of articular cartilage and prevent its degradation.

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

    International Nuclear Information System (INIS)

    Jeong, Hee Jeong; Jung, Yeon Hwa; Cho, Bong Hae

    1997-01-01

    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.

  2. 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.

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

    Science.gov (United States)

    Imamura, Takeshi; Saiki, Kazunobu; Okamoto, Keishi; Maeda, Junichiro; Matsuo, Hiroaki; Wakebe, Tetsuaki; Ogami, Keiko; Tomita, Masato; Tagami, Atsushi; Shindo, Hiroyuki; Tsurumoto, Toshiyuki

    2014-01-01

    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. PMID:25276825

  4. 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

  5. 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)

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

    Directory of Open Access Journals (Sweden)

    Irina Kerna

    2013-01-01

    Full Text Available 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, . 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, . Also the CCAA haplotype of ADAM12 was associated with osteophytosis, again mostly in TFJ in males (. 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.

  7. Morphologic and radiologic data of isolated vertebral end-plates under particular consideration of radiodensitometry

    International Nuclear Information System (INIS)

    Unflath, U.

    1979-01-01

    The intention was to find examination techniques for macroscopico-morphological diagnosis, for quantification of the concavity and methods for roentgenologico-densitometric analysis of vertebral end-plates. The following factors were used for macromorphologic diagnosis: osteophytes, ridge constitution, ridge transition, cribriform plate and concavity. The radiodensitometric analysis comprised investigation of bone density, anisotropy and ridge mineralisation. The specimen were radiographed on a mammograph together with calcium chloride solutions of increasing concentration. Statistically significant differences in the behaviour of basal and upper plates were not observed. With reference to the factors osteophytes and ridge constitution the basal plates seem to be morphologically more variable than the upper plates. It resulted that the features absolute concavity and concavity quotient are highly appropriate factors to document the constitution of the isolated vertebral end-plates. Also the features density, anisotropy and ridge mineralisation were found to be useful for documentation. The result of data correlation was that high concavity quotients are accompanied by macroscopically medium- to small-sized pores. Density and anisotropy of the overall profiles do not show correlation, but voluminous cribriform laminae tend to develop more inhomogenic structures. As to be expected, bone density increases with macroscopic fine porosity. The higher the concavity quotient is, the smaller are the values for density, ridge mineralisation and anisotropy. Thus a high degree of vertebral end-plate concavity indicates reduced bone density and lower mineral content. (orig./MG) [de

  8. Relationships between rotator cuff tear types and radiographic abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying [Dept. of Diagnostic Radiology, College of Medicine, Chungbuk National University, Cheongju (Korea, Republic of)

    2014-11-15

    To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

  9. Lumbar Scoliosis Combined Lumbar Spinal Stenosis and Herniation Diagnosed Patient Was Treated with “U” Route Transforaminal Percutaneous Endoscopic Lumbar Discectomy

    Directory of Open Access Journals (Sweden)

    Binbin Wu

    2017-01-01

    Full Text Available The objective was to report a case of a 63-year-old man with a history of low back pain (LBP and left leg pain for 2 years, and the symptom became more serious in the past 5 months. The patient was diagnosed with lumbar scoliosis combined with lumbar spinal stenosis (LSS and lumbar disc herniation (LDH at the level of L4-5 that was confirmed using Computerized Topography and Magnetic Resonance Imaging. The surgical team preformed a novel technique, “U” route transforaminal percutaneous endoscopic lumbar discectomy (PELD, which led to substantial, long-term success in reduction of pain intensity and disability. After removing the osteophyte mass posterior to the thecal sac at L4-5, the working channel direction was changed to the gap between posterior longitudinal ligament and thecal sac, and we also removed the herniation and osteophyte at L3-4 with “U” route PELD. The patient’s symptoms were improved immediately after the surgical intervention; low back pain intensity decreased from preoperative 9 to postoperative 2 on a visual analog scale (VAS recorded at 1 month postoperatively. The success of the intervention suggests that “U” route PELD may be a feasible alternative to treat lumbar scoliosis with LSS and LDH patients.

  10. Functional interrelations between the lumbosacral, sacroiliac and coxofemoral complex in dogs as denoted by degenerative joint diseases

    International Nuclear Information System (INIS)

    Kuenzel, W.; Breit, S.; Knaus, I.

    2002-01-01

    Functional interrelations between coxofemoral joint, sacroiliac joint and the lumbosacral junction were investigated in Rottweilers, Golden Retriever and German Shepherd dogs. The study was based on sample of 120 ventrodorsal radiographs of the pelvis, which was assessed for evidence of hip dysplasia, alterations of the synovial and extrasynovial components of the sacroiliac joints, and osteophyte formation at the lumbosacral junction. Alteration of the extrasynovial component of the sacroiliac joint was the disease most commonly observed. Such degenerative alterations of the sacroiliac joint were noted to be associated with osteophyte formation at the lumbosacral junction. Both diseases were associated with age and German Shepherd dogs were most frequently affected. Results obtained by the additional evaluation of the coxofemoral joints suggest two mechanisms inducing degenerative alterations at the joint complex investigated. Based on changes in collagen composition, congenitally determined insufficiency of the supporting connective tissue may be responsible for the coincidence of alterations of all joint components of the lumbosacral - sacroilia - coxofemoral complex as noted in one group of dogs. In contrast, pre-dominant affection of the sacroiliac amphiarthosis and the lumbosacral intervertebral disc space is supposed to result from cumulative overloading. (author)

  11. Popliteal cysts and subgastrocnemius bursitis are associated with knee symptoms and structural abnormalities in older adults: a cross-sectional study.

    Science.gov (United States)

    Cao, Yuelong; Jones, Graeme; Han, Weiyu; Antony, Benny; Wang, Xia; Cicuttini, Flavia; Ding, Changhai

    2014-03-03

    The role of popliteal cysts and subgastrocnemius bursitis in knee joint homeostasis is uncertain. The aim of this study is to describe cross-sectional associations between popliteal cysts, subgastrocnemius bursitis, knee symptoms and structural abnormalities in older adults. A cross-sectional sample of 900 randomly-selected subjects (mean age 63 years, 48% female) were studied. Knee pain, stiffness and dysfunction were assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire. Radiographic knee osteophyte and joint space narrowing (JSN) were recorded. Magnetic resonance imaging (MRI) was utilized to assess popliteal cysts, subgastrocnemius bursitis, cartilage defects and bone marrow lesions (BMLs). Popliteal cysts were present in 11.7% and subgastrocnemius bursitis in 12.7% of subjects. Subgastrocnemius bursitis was more common in those with popliteal cyst (36.2% versus 9.7%, P bursitis was associated with increased osteophytes and JSN in the medial tibiofemoral compartment. Both were significantly associated with cartilage defects in all compartments, and with BMLs in the medial tibiofemoral compartment. Furthermore, both popliteal cysts and subgastrocnemius bursitis were significantly associated with increased weight-bearing knee pain but these associations became non-significant after adjustment for cartilage defects and BMLs. Popliteal cysts and subgastrocnemius bursitis are associated with increased symptoms as well as radiographic and MRI-detected joint structural abnormalities. Longitudinal data will help resolve if they are a consequence or a cause of knee joint abnormalities.

  12. Science and animal models of marrow stimulation for cartilage repair.

    Science.gov (United States)

    Fortier, Lisa A; Cole, Brian J; McIlwraith, C Wayne

    2012-03-01

    Microfracture of subchondral bone to enhance cartilage repair is a popular surgical technique used in human and animal patients. Clinical results with resolution or improvement in pain are promising and last on average for 2 to 3 years. Animal studies aimed at understanding microfracture indicate that the repair tissue continues to remodel toward chondrogenesis for at least a year, but longer term results are not available to gain insight into the mechanism of microfracture function or failure over time. Subchondral bone sclerosis and central lesional osteophyte formation following subchondral bone microfracture have been observed in animal models of microfracture, but studies do not provide any insight into the etiology of these pathologies. The continued maturation of microfracture repair tissue over time supports further investigation of microfracture or microfracture-augmented cartilage repair procedures with caution for the investigator and clinician to be observant for conditions that lead to subchondral bone sclerosis or central osteophyte formation, and what affect these boney reactions have on clinical outcome.

  13. Creation of a reflecting formula to determine a patient's indication for undergoing total knee arthroplasty.

    Science.gov (United States)

    Chan, Wing P; Hsu, Shu-Mei; Huang, Guo-Shu; Yao, Min-Szu; Chang, Yue-Chune; Ho, Wei-Pin

    2010-01-01

    The aim of this study was to develop, from patients' characteristics and radiography, a formula reflecting the decision for total knee arthroplasty (TKA) in patients with a painful osteoarthritic knee. We reviewed medical records of 193 consecutive patients who had knee osteoarthritis and underwent primary TKA surgery and 133 consecutive patients with knee osteoarthritis who did not have surgery in one institution during the preceding 5 years. Two skeletal radiologists graded, from 0 to 3, radiographic joint space narrowing (JSN), osteophytes, subchondral sclerosis, and subchondral cysts. The association between the variables and outcome were calculated by the chi-squared test and multivariable logistic regression. Women had more TKAs than men (P = 0.002), and the TKA and non-TKA groups differed in terms of self-care ability (P osteophytes in the medial compartment. The retrospective sensitivity and specificity for patients who underwent TKA surgery were 84% and 83%, respectively. The diagnostic efficacy in retrospect evaluated by a receiver operating characteristic curve was 0.92. A formula reflecting the decision for TKA surgery in patients with a painful osteoarthritic knee has been developed with acceptable diagnostic efficacy obtained retrospectively. The formula should be validated by further study.

  14. Use of routine clinical multimodality imaging in a rabbit model of osteoarthritis--part I.

    Science.gov (United States)

    Bouchgua, M; Alexander, K; d'Anjou, M André; Girard, C A; Carmel, E Norman; Beauchamp, G; Richard, H; Laverty, S

    2009-02-01

    To evaluate in vivo the evolution of osteoarthritis (OA) lesions temporally in a rabbit model of OA with clinically available imaging modalities: computed radiography (CR), helical single-slice computed tomography (CT), and 1.5 tesla (T) magnetic resonance imaging (MRI). Imaging was performed on knees of anesthetized rabbits [10 anterior cruciate ligament transection (ACLT) and contralateral sham joints and six control rabbits] at baseline and at intervals up to 12 weeks post-surgery. Osteophytosis, subchondral bone sclerosis, bone marrow lesions (BMLs), femoropatellar effusion and articular cartilage were assessed. CT had the highest sensitivity (90%) and specificity (91%) to detect osteophytes. A significant increase in total joint osteophyte score occurred at all time-points post-operatively in the ACLT group alone. BMLs were identified and occurred most commonly in the lateral femoral condyle of the ACLT joints and were not identified in the tibia. A significant increase in joint effusion was present in the ACLT joints until 8 weeks after surgery. Bone sclerosis or cartilage defects were not reliably assessed with the selected imaging modalities. Combined, clinically available CT and 1.5 T MRI allowed the assessment of most of the characteristic lesions of OA and at early time-points in the development of the disease. However, the selected 1.5 T MRI sequences and acquisition times did not permit the detection of cartilage lesions in this rabbit OA model.

  15. Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography

    International Nuclear Information System (INIS)

    Turmezei, Tom D.; Treece, Graham M.; Gee, Andrew H.; Fotiadou, Anastasia F.; Poole, Kenneth E.S.

    2016-01-01

    To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data. Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K and L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data. For each increase in K and L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head-neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head-neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW. These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis. (orig.)

  16. Association between disk position and degenerative bone changes of the temporomandibular joints: an imaging study in subjects with TMD.

    Science.gov (United States)

    Cortés, Daniel; Sylvester, Daniel Cortés; Exss, Eduardo; Marholz, Carlos; Millas, Rodrigo; Moncada, Gustavo

    2011-04-01

    The aim of this study was to determine the frequency and relationship between disk position and degenerative bone changes in the temporomandibular joints (TMJ), in subjects with internal derangement (ID). MRI and CT scans of 180 subjects with temporomandibular disorders (TMD) were studied. Different image parameters or characteristics were observed, such as disk position, joint effusion, condyle movement, degenerative bone changes (flattened, cortical erosions and irregularities), osteophytes, subchondral cysts and idiopathic condyle resorption. The present study concluded that there is a significant association between disk displacement without reduction and degenerative bone changes in patients with TMD. The study also found a high probability of degenerative bone changes when disk displacement without reduction is present. No association was found between TMD and condyle range of motion, joint effusion and/or degenerative bone changes. The following were the most frequent morphological changes observed: flattening of the anterior surface of the condyle; followed by erosions and irregularities of the joint surfaces; flattening of the articular surface of the temporal eminence, subchondral cysts, osteophytes; and idiopathic condyle resorption, in decreasing order.

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

    International Nuclear Information System (INIS)

    Kwon, Jong Won; Kang, Heung Sik; Hong, Sung Hwan

    2010-01-01

    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

  18. Early signs of osteoarthritis in professional ballet dancers: a preliminary study.

    Science.gov (United States)

    Angioi, Manuela; Maffulli, Gayle D; McCormack, Moira; Morrissey, Dylan; Chan, Otto; Maffulli, Nicola

    2014-09-01

    To investigate a cohort of professional ballet dancers for evidence of early signs of osteoarthritis (OA). One radiologist and 1 orthopedic surgeon specialized in musculoskeletal disorders analyzed magnetic resonance imaging scans independently. University Teaching Hospital. Fifteen professional ballet dancers (4 males and 11 females; age range, 19-36 years) experiencing chronic pain in the hip, knee, spine, ankle, or foot joints. Presence of osteophytes, subchondral sclerosis, joint space narrowing, cysts, and bone marrow changes; the Kellgren and Lawrence scale was used to quantify the knee OA. In the knee, there was thinning and irregularity of the articular cartilage over the medial femoral condyle and bone marrow changes within the lateral femoral condyle. In the hip, there was a loss of joint space and a frayed labrum with deep recess. The first metatarsophalangeal joint showed evidence of osteophytic development. Early signs of OA, in different joints, were present in a small but highly selected cohort of professional ballet dancers. In future, prospective studies among a number of ballet companies should control for medical and natural history alongside the visual analysis of images and plain radiographs to confirm these preliminary results.

  19. Early Changes of Articular Cartilage and Subchondral Bone in The DMM Mouse Model of Osteoarthritis.

    Science.gov (United States)

    Fang, Hang; Huang, Lisi; Welch, Ian; Norley, Chris; Holdsworth, David W; Beier, Frank; Cai, Daozhang

    2018-02-12

    To examine the early changes of articular cartilage and subchondral bone in the DMM mouse model of osteoarthritis, mice were subjected to DMM or SHAM surgery and sacrificed at 2-, 5- and 10-week post-surgery. Catwalk gait analyses, Micro-Computed Tomography, Toluidine Blue, Picrosirius Red and Tartrate-Resistant Acid Phosphatase (TRAP) staining were used to investigate gait patterns, joint morphology, subchondral bone, cartilage, collagen organization and osteoclasts activity, respectively. Results showed OA progressed over 10-week time-course. Gait disparity occurred only at 10-week post-surgery. Osteophyte formed at 2-week post-surgery. BMDs of DMM showed no statistical differences comparing to SHAM at 2 weeks, but BV/TV is much higher in DMM mice. Increased BMD was clearly found at 5- and 10-week post-surgery in DMM mice. TRAP staining showed increased osteoclast activity at the site of osteophyte formation of DMM joints at 5- and 10-week time points. These results showed that subchondral bone turnover might occurred earlier than 2 weeks in this mouse DMM model. Gait disparity only occurred at later stage of OA in DMM mice. Notably, patella dislocation could occur in some of the DMM mice and cause a different pattern of OA in affected knee.

  20. Co-expression of DKK-1 and Sclerostin in Subchondral Bone of the Proximal Femoral Heads from Osteoarthritic Hips.

    Science.gov (United States)

    Zarei, Allahdad; Hulley, Philippa A; Sabokbar, Afsie; Javaid, M Kassim

    2017-06-01

    Osteoarthritis (OA) is a progressively degenerative joint disease influenced by structural and metabolic factors. There is growing evidence that subchondral bone is involved in both symptomatic and structural progression in OA. The Wnt pathway has been implicated in the progression of OA but the expression and function of the Wnt inhibitors, Dikkopf (DKK-1) and sclerostin (SOST), are unclear. We examined the regional distribution of DKK-1 and SOST in subchondral bone of the femoral head using resection specimens following arthroplasty in patients presenting with end-stage OA. Cylindrical cores for immunohistochemistry were taken through midpoint of full thickness cartilage defect, partial cartilage defect, through base of osteophyte and through macroscopically normal cartilage. Subchondral bone was thickest in cores taken from regions with full cartilage defect and thinnest in cores taken from osteophyte regions. In subchondral bone, expression of both DKK-1 and SOST was observed exclusively in osteocytes. Expression was highest in subchondral bone in cores taken from regions with partial but not full thickness cartilage defects. DKK-1 but not SOST was expressed by chondrocytes in cores with macroscopically normal cartilage. The current study describes the regional cellular distribution of SOST and DKK-1 in hip OA. Expression was highest in the osteocytes in bone underlying partial thickness cartilage defects. It is however not clear if this is a cause or a consequence of alterations in the overlying cartilage. However, it is suggestive of an active remodeling process which might be targeted by disease-modifying agents.

  1. A novel algorithm for a precise analysis of subchondral bone alterations

    Science.gov (United States)

    Gao, Liang; Orth, Patrick; Goebel, Lars K. H.; Cucchiarini, Magali; Madry, Henning

    2016-01-01

    Subchondral bone alterations are emerging as considerable clinical problems associated with articular cartilage repair. Their analysis exposes a pattern of variable changes, including intra-lesional osteophytes, residual microfracture holes, peri-hole bone resorption, and subchondral bone cysts. A precise distinction between them is becoming increasingly important. Here, we present a tailored algorithm based on continuous data to analyse subchondral bone changes using micro-CT images, allowing for a clear definition of each entity. We evaluated this algorithm using data sets originating from two large animal models of osteochondral repair. Intra-lesional osteophytes were detected in 3 of 10 defects in the minipig and in 4 of 5 defects in the sheep model. Peri-hole bone resorption was found in 22 of 30 microfracture holes in the minipig and in 17 of 30 microfracture holes in the sheep model. Subchondral bone cysts appeared in 1 microfracture hole in the minipig and in 5 microfracture holes in the sheep model (n = 30 holes each). Calculation of inter-rater agreement (90% agreement) and Cohen’s kappa (kappa = 0.874) revealed that the novel algorithm is highly reliable, reproducible, and valid. Comparison analysis with the best existing semi-quantitative evaluation method was also performed, supporting the enhanced precision of this algorithm. PMID:27596562

  2. 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.

  3. [Mechanical behavior of the subchondral bone in the experimentally induced osteoarthritis].

    Science.gov (United States)

    Miyanaga, Y

    1979-06-01

    In order to evaluate the role of the subchondral bone (cancellous bone) in the development and progression of the joint degeneration, osteoarthritis of the knee joint was produced experimentally in the rabbits and viscoelasticity and strength of the subchondral bone from the femoral medial condyle have been investigated along with the pathological, histological study of the joint. The viscoelastic spectrometer and the Instron type testing machine were used. As the first change after operation, osteophyte formation around the joint margin has been observed before the initiation of the degeneration of articular cartilage and there is a possibility that mechanical properties of subchondral bone such as high deformability and low elasticity to the mechanism of osteophyte formation. Subchondral bone softening with marked increase of ultimate strain and phase lag, marked decrease of compressive elastic modulus and ultimate stress precedes or occurs concurrently with the degeneration of the articular cartilage. These facts indicate the relationship between the mechanical properties of the subchondral bone and joint degeneration. Once the joint degeneration starts, degeneration continues progressively while the subchondral bone tends to become brittle. These changes may be considered as a kind of functional adaptation to the damage or denudation of articular cartilage. It is postulated that some architectural changes of the subchondral bone may provide alterations of the mechanical properties. Biomechanical roles of the subchondral bone is suggested as one of the factors in the joint degeneration.

  4. Cervical Hyperostosis Leading to Dyspnea, Aspiration and Dysphagia: Strategies to Improve Patient Management

    Directory of Open Access Journals (Sweden)

    Georgios Psychogios

    2018-04-01

    Full Text Available Diffuse idiopathic skeletal hyperostosis (DISH is a rare but well known cause of dysphagia. In very few cases aspiration and dyspnea are described as a clinical manifestation. An 82-year-old man presented himself in our clinic with severe dyspnea, aspiration, and pneumonia. After performing a microlaryngoscopy an emergency tracheotomy became necessary.In laryngoscopy a severe bulging of the posterior oropharyngeal and hypopharyngeal wall was detected. The glottis area was not observable and immobilisation of the right vocal cord could be detected. The CT showed anterior osteophytes and ossification of the anterior longitudinal ligament from C2–C7. We performed a panendoscopy in order to explore the upper aerodigestive area. Postoperatively an emergency tracheotomy was needed due to the development of laryngeal edema. The osteophytes were removed in cooperation with the department of orthopaedics. Three months postoperative the patient had no dyspnea or dysphagia, so the tracheotomy could be closed.Cervical hyperostosis is commonly described in elderly patients and usually presenting without symptoms, therefore a surgical treatment is usually not necessary. Nevertheless it can lead to severe morbidity and dyspnea with airway obstruction. Therefore it is essential that cervical hyperostosis is recognized early enough and appropriate treatment is initiated. Flexible endoscopy should be preferred over direct panendoscopy because it could lead to life-threatening edema and a prophylactic tracheostomy should be strongly considered in patients that present with severe dyspnea,

  5. The knee in diffuse idiopathic skeletal hyperostosis

    International Nuclear Information System (INIS)

    Orzincolo, C.; Scutellari, P.N.; Aiello, N.; Trotta, F.

    1987-01-01

    Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder characterized by bone proliferation of spinal and extraspinal structures. Frequently, extraspinal manifestations may occur before the involvement of the spine. These alterations are so common and characteristc that they should be included in diagnostic criteria for DISH. The patella is one of the most commonly involved sites. The knee of 48 patients affected by DISH, according to Resnick's diagnostic criteria, were subjected to systematic, radiographic and xerographic studies. The most characteristic radiographic patterns are: thickening of the anterior margin of the patella (81.1%); ossifying enthesopathy of supero-anterior margin of patella (68.7%); periosteal new bone formation on the tibial insertion of the cruciateligaments (47.8%); presence of fabella (41%); presence of megafabella (22.9%), which may come near the posterior profile of the femur. Changes are usually symmetrical in DISH: entheseal abnormalities mostly involve the antero-superior margin of the patella, whereas in osteoarthritis, osteophytes are found on the postero-superior margin. In the lateral view enthesophytes at the bone attachment of the cruciate ligaments are oriented inside the joint space; on the contrary, osteophytes are always oriented outside the joint space. Radiographic manifestations of the fabella are similar to those observed in osteoarthritis, and so they cannot be utilized in the differential diagnosis of these diseases

  6. Relationships between rotator cuff tear types and radiographic abnormalities

    International Nuclear Information System (INIS)

    Lee, Soo Hyun; Chun, Kyung Ah; Lee Soo Jung; Kang, Min Ho; Yi, Kyung Sik; Zhang, Ying

    2014-01-01

    To determine relationships between different types of rotator cuff tears and radiographic abnormalities. The shoulder radiographs of 104 patients with an arthroscopically proven rotator cuff tear were compared with similar radiographs of 54 age-matched controls with intact cuffs. Two radiologists independently interpreted all radiographs for; cortical thickening with subcortical sclerosis, subcortical cysts, osteophytes in the humeral greater tuberosity, humeral migration, degenerations of the acromioclavicular and glenohumeral joints, and subacromial spurs. Statistical analysis was performed to determine relationships between each type of rotator cuff tears and radiographic abnormalities. Inter-observer agreements with respect to radiographic findings were analyzed. Humeral migration and degenerative change of the greater tuberosity, including sclerosis, subcortical cysts, and osteophytes, were more associated with full-thickness tears (p < 0.01). Subacromial spurs were more common for full-thickness and bursal-sided tears (p < 0.01). No association was found between degeneration of the acromioclavicular or glenohumeral joint and the presence of a cuff tear. Different types of rotator cuff tears are associated with different radiographic abnormalities.

  7. 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

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

    International Nuclear Information System (INIS)

    Donescu, O.S.; Battie, M.C.; Videman, T.

    2007-01-01

    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

  9. Osteoarthritis of the thumb carpometacarpal joint: Correlation of ultrasound appearances to disability and treatment response

    International Nuclear Information System (INIS)

    Mallinson, P.I.; Tun, J.K.; Farnell, R.D.; Campbell, D.A.; Robinson, P.

    2013-01-01

    Aim: To evaluate grading of thumb carpometacarpal joint (CMCJ) osteoarthritis (OA) using ultrasound, correlating findings with disability and treatment response. Materials and methods: Patients with symptomatic thumb OA attending for ultrasound-guided CMCJ steroid injection and a group of asymptomatic controls were recruited prospectively. Thumb CMCJ ultrasound was graded (osteophytes, joint-space narrowing, capsule size, and measured capsule size), and a Disabilities of the Arm Shoulder and Hand (DASH) questionnaire was completed for each patient. Symptomatic patients then underwent injection with DASH repeated 6 weeks post-treatment. Ultrasound features were correlated with the initial DASH disability score and response as defined by change in DASH 6 weeks after treatment. Results: Thirty-one patients with symptomatic OA and 37 asymptomatic controls were recruited. With the exception of osteophytes (p = 0.017), no statistically significant correlation was demonstrated between severity of ultrasound features and patient disability. However, all features demonstrated statistically significant higher grades in the symptomatic group compared to controls. Ultrasound grading did not have statistical correlation with treatment response. Conclusion: No correlation was found between the majority of ultrasound features and the clinical severity of OA or likely response to treatment. However, these features are significantly more common in the symptomatic population

  10. 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.

  11. Production of an electron-positron plasma in a pulsar magnetosphere

    International Nuclear Information System (INIS)

    Gurevich, A.V.; Istomin, Y.N.

    1985-01-01

    A study is made of the production of electron-positron plasma in the vacuum state (''breakdown'' of the vacuum) in the presence of an inhomogeneous electric field and a strong curvilinear magnetic field. Such conditions are encountered in the magnetosphere of a rotating neutron star. A general system of kinetic equations is derived for the electrons, positrons, and γ photons in the curvilinear magnetic field with allowance for the production of electron-positron pairs and the emission of curvature and synchrotron photons. The conditions of occurrence of ''breakdown'' are determined, and the threshold value of the jump in the value of the electric field at the surface of the star is found. The process of multiplication of particles in the magnetosphere is investigated, and the distribution functions of the electrons, positrons, and photons are found. The extinction limit of pulsars is determined. It is shown that the theory is in agreement with observational data

  12. Electron-positron plasma generation in a pulsar magnetosphere

    International Nuclear Information System (INIS)

    Gurevich, A.V.; Istomin, Ya.N.

    1985-01-01

    The generation of an electron-positron plasma in vacuum (vacuum ''breakdown'') in the presence of an inhomogeneous electric field and strong curvilinear magnetic field is considered. A situation of this type may occur in the magnetosphere of a rotating neutron star. A general set of kinetic equations for electrons, positrons and γ quanta in a curvilinear magnetic field is derived by taking into account electron-positron pair production and emission of curvicur and synchrotron photons. The conditions for appearance of ''breakdown'' are determined and the threshold value of the elec tric field discontinuity at the surface of the star is found. Multiplication of particles in the magnetosphere is investigated and the electron, positron and γ quantum distribution functions are found. The extinction limit of pulsars is determined. The theory is shown to be in accordance with the observation results

  13. Political conservatism, rigidity, and dogmatism in American foreign policy officials: the 1966 Mennis data.

    Science.gov (United States)

    Kemmelmeier, Markus

    2007-01-01

    Researchers have established a relationship between political orientation and cognitive styles (A. Chirumbolo, 2002; J. T. Jost, J. Glaser, A. W. Kruglanski, & F. Sulloway, 2003a, 2003b; M. Kemmelmeier, 1997). In this article, the author examined whether this finding is true in the political elite, whether the relationship is linear or curvilinear, and whether interest in politics moderates the relationship between political orientation and cognitive styles. He used a 1966 sample of American foreign policy officials (N = 95) to examine the relationship between self-described conservatism and party identification and individual differences in rigidity and dogmatism. Rigidity was related to self-described conservatism, but this relationship was only significant among participants high in political interest, whereas dogmatism was unconditionally related to party identification. All relationships were linear and did not contain a curvilinear component.

  14. 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...... 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...... 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...

  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. Effects of sharp vorticity gradients in two-dimensional hydrodynamic turbulence

    DEFF Research Database (Denmark)

    Kuznetsov, E.A.; Naulin, Volker; Nielsen, Anders Henry

    2007-01-01

    The appearance of sharp vorticity gradients in two-dimensional hydrodynamic turbulence and their influence on the turbulent spectra are considered. We have developed the analog of the vortex line representation as a transformation to the curvilinear system of coordinates moving together with the ......The appearance of sharp vorticity gradients in two-dimensional hydrodynamic turbulence and their influence on the turbulent spectra are considered. We have developed the analog of the vortex line representation as a transformation to the curvilinear system of coordinates moving together...... with the divorticity lines. Compressibility of this mapping can be considered as the main reason for the formation of the sharp vorticity gradients at high Reynolds numbers. For two-dimensional turbulence in the case of strong anisotropy the sharp vorticity gradients can generate spectra which fall off as k−3 at large...

  17. The Takete-Maluma phenomenon in autism spectrum disorders.

    Science.gov (United States)

    Occelli, Valeria; Esposito, Gianluca; Venuti, Paola; Arduino, Giuseppe Maurizio; Zampini, Massimiliano

    2013-01-01

    It has been reported that people tend to preferentially associate phonemes like /m/, /l/, /n/ to curvilinear shapes and phonemes like /t/, /z/, /r/, /k/ to rectilinear shapes. Here we evaluated the performance of children/adolescents with autism spectrum disorders (ASD) and neurotypical controls in this audiovisual congruency phenomenon. Pairs of visual patterns (curvilinear vs rectilinear) were presented to a group of ASD participants (low- or high-functioning) and a group of age-matched neurotypical controls. Participants were asked to associate each item to non-meaningful phoneme clusters. ASD participants showed a lower proportion of expected association responses than the controls. Within the ASD group the performance varied as a function of the severity of the symptomatology. These data suggest that children/adolescents with ASD show, although at different degrees as a function of the severity of the ASD, lower phonetic-iconic congruency response patterns than neurotypical controls, pointing to poorer multisensory integration capabilities.

  18. 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. © The Author(s) 2015.

  19. Developing a Social Enterprise Performance Scale and Examining the Relationship Between Entrepreneurs’ Personality Traits and Their Perceived Enterprise Performance

    Directory of Open Access Journals (Sweden)

    Chao-Tung Liang

    2015-01-01

    Full Text Available On the basis of the lack of measurement tools and the research gap regarding social entrepreneurship, three studies were conducted to develop a new measure of social enterprise (SE performance that is empirically valid and easy to administer. The purpose of this measure was to examine the relationship between entrepreneurs’ personality traits and their perceived SE performance. The results indicated that SE performance can be assessed using four dimensions: personal issues, social aspects, business elements, and service programmes. Extraversion positively influenced service programmes, and openness negatively affected service programmes. Neuroticism and conscientiousness positively predicted personal issues and service programmes, and agreeableness positively predicted all dimensions of perceived SE performance. The results also demonstrated the curvilinear relationship of the U-shaped curve between neuroticism and personal issues and the social aspects of SE performance. Furthermore, the results showed the curvilinear relationship of the inverted U-shaped curve between agreeableness and the four dimensions of SE performance.

  20. Task conflict and team creativity: a question of how much and when.

    Science.gov (United States)

    Farh, Jiing-Lih; Lee, Cynthia; Farh, Crystal I C

    2010-11-01

    Bridging the task conflict, team creativity, and project team development literatures, we present a contingency model in which the relationship between task conflict and team creativity depends on the level of conflict and when it occurs in the life cycle of a project team. In a study of 71 information technology project teams in the greater China region, we found that task conflict had a curvilinear effect on team creativity, such that creativity was highest at moderate levels of task conflict. Additionally, we found this relationship to be moderated by team phase, such that the curvilinear effect was strongest at an early phase. In contrast, at later phases of the team life cycle, task conflict was found to be unrelated to team creativity. (c) 2010 APA, all rights reserved.

  1. Metastable Amyloid Phases and their Conversion to Mature Fibrils

    Science.gov (United States)

    Muschol, Martin; Miti, Tatiana; Mulaj, Mentor; Schmit, Jeremy

    Self-assembly of proteins into amyloid fibrils plays a key role in both functional biological responses and pathogenic disorders which include Alzheimer's disease and type II diabetes. Amyloid fibril assembly frequently generates compact oligomeric and curvilinear polymeric intermediates which are implicated to be toxic to cells. Yet, the relation between these early-stage oligomeric aggregates and late-stage rigid fibrils, which are the hallmark structure of amyloid plaques, has remained unclear. Our measurements indicate that lysozyme amyloid oligomers and their curvilinear fibrils only form after crossing a salt and protein concentration dependent threshold. These oligomeric aggregates are structurally distinct from rigid fibrils and are metastable against nucleation and growth of rigid fibrils. Our experimental transition boundaries match well with colloidal model predictions accounting for salt-modulated charge repulsion. We also report our preliminary findings on the mechanism by which these metastable oligomeric phases are converted into stable amyloid fibrils.

  2. 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.

  3. Designs of Plasmonic Metamasks for Photopatterning Molecular Orientations in Liquid Crystals

    Directory of Open Access Journals (Sweden)

    Yubing Guo

    2016-12-01

    Full Text Available Aligning liquid crystal (LC molecules into spatially non-uniform orientation patterns is central to the functionalities of many emerging LC devices. Recently, we developed a new projection photopatterning technique by using plasmonic metamasks (PMMs, and demonstrated high-resolution and high-throughput patterning of molecular orientations into arbitrary patterns. Here we present comparisons between two different types of metamask designs: one based on curvilinear nanoslits in metal films; the other based on rectangular nanoapertures in metal films. By using numerical simulations and experimental studies, we show that the PMMs based on curvilinear nanoslits exhibit advantages in their broadband and high optical transmission, while face challenges in mask designing for arbitrary molecular orientations. In contrast, the PMMs based on nanoapertures, though limited in optical transmission, present the great advantage of allowing for patterning arbitrary molecular orientation fields.

  4. Computation of turbulent reacting flow in a solid-propellant ducted rocket

    Science.gov (United States)

    Chao, Yei-Chin; Chou, Wen-Fuh; Liu, Sheng-Shyang

    1995-05-01

    A mathematical model for computation of turbulent reacting flows is developed under general curvilinear coordinate systems. An adaptive, streamline grid system is generated to deal with the complex flow structures in a multiple-inlet solid-propellant ducted rocket (SDR) combustor. General tensor representations of the k-epsilon and algebraic stress (ASM) turbulence models are derived in terms of contravariant velocity components, and modification caused by the effects of compressible turbulence is also included in the modeling. The clipped Gaussian probability density function is incorporated in the combustion model to account for fluctuations of properties. Validation of the above modeling is first examined by studying mixing and reacting characteristics in a confined coaxial-jet problem. This is followed by study of nonreacting and reacting SDR combustor flows. The results show that Gibson and Launder's ASM incorporated with Sarkar's modification for compressible turbulence effects based on the general curvilinear coordinate systems yields the most satisfactory prediction for this complicated SDR flowfield.

  5. The Money Buffer Effect in China: A Higher Income Cannot Make You Much Happier but might Allow You to Worry Less

    Directory of Open Access Journals (Sweden)

    Bin eLi

    2016-02-01

    Full Text Available 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.

  6. Improvement of prediction accuracy of large eddy simulation on colocated grids; Colocation koshi wo mochiita LES no keisan seido kaizen ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, M.; Abe, K. [Toyota Central Research and Development Labs., Inc., Aichi (Japan)

    1998-07-25

    With the recent advances in computers, large eddy simulation (LES) has become applicable to engineering prediction. However, most cases of the engineering applications need to use the nonorthgonal curvilimear coordinate systems. The staggered grids, usually used in LES in the orthgonal coordinates, don`t keep conservative properties in the nonorthgonal curvilinear coordinates. On the other hand, the colocated grids can be applied in the nonorthgonal curvilinear coordinates without losing its conservative properties, although its prediction accuracy isn`t so high as the staggered grid`s in the orthgonal coordinates especially with the coarse grids. In this research, the discretization method of the colocated grids is modified to improve its prediction accuracy. Plane channel flows are simulated on four grids of different resolution using the modified colocated grids and the original colocated grids. The results show that the modified colocated grids have higher accuracy than the original colocated grids. 17 refs., 13 figs., 1 tab.

  7. Near-Body Grid Adaption for Overset Grids

    Science.gov (United States)

    Buning, Pieter G.; Pulliam, Thomas H.

    2016-01-01

    A solution adaption capability for curvilinear near-body grids has been implemented in the OVERFLOW overset grid computational fluid dynamics code. The approach follows closely that used for the Cartesian off-body grids, but inserts refined grids in the computational space of original near-body grids. Refined curvilinear grids are generated using parametric cubic interpolation, with one-sided biasing based on curvature and stretching ratio of the original grid. Sensor functions, grid marking, and solution interpolation tasks are implemented in the same fashion as for off-body grids. A goal-oriented procedure, based on largest error first, is included for controlling growth rate and maximum size of the adapted grid system. The adaption process is almost entirely parallelized using MPI, resulting in a capability suitable for viscous, moving body simulations. Two- and three-dimensional examples are presented.

  8. Parallel/vector algorithms for the spherical SN transport theory method

    International Nuclear Information System (INIS)

    Haghighat, A.; Mattis, R.E.

    1990-01-01

    This paper discusses vector and parallel processing of a 1-D curvilinear (i.e. spherical) S N transport theory algorithm on the Cornell National SuperComputer Facility (CNSF) IBM 3090/600E. Two different vector algorithms were developed and parallelized based on angular decomposition. It is shown that significant speedups are attainable. For example, for problems with large granularity, using 4 processors, the parallel/vector algorithm achieves speedups (for wall-clock time) of more than 4.5 relative to the old serial/scalar algorithm. Furthermore, this work has demonstrated the existing potential for the development of faster processing vector and parallel algorithms for multidimensional curvilinear geometries. (author)

  9. An incidental case of biliary fascioliasis with subtle clinical findings: US and MRCP findings

    International Nuclear Information System (INIS)

    Önder, Hakan; Ekici, Faysal; Adin, Emin; Kuday, Suzan; Gümüş, Hatice; Bilici, Aslan

    2013-01-01

    Fascioliasis is a disease caused by the trematode Fasciola hepatica. Cholangitis is a common clinical manifestation. Although fascioliasis may show various radiological and clinical features, cases without biliary dilatation are rare. We present unique ultrasound (US) and magnetic resonance cholangiopancreatography (MRCP) findings of a biliary fascioliasis case which doesn’t have biliary obstruction or cholestasis. Radiologically, curvilinear parasites compatible with juvenile and mature Fasciola hepatica within the gallbladder and common bile duct were found. The parasites appear as bright echogenic structures with no acoustic shadow on US and hypo-intense curvilinear lesions on T2 weighted MRCP images. Imaging studies may significantly contribute to the diagnosis of patients with subtle clinical and laboratory findings, particularly in endemic regions

  10. 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.

  11. Anharmonic Rovibrational Partition Functions for Fluxional Species at High Temperatures via Monte Carlo Phase Space Integrals

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, Ahren W. [Chemical Sciences and Engineering; Gruey, Zackery B. [Chemical Sciences and Engineering; Harding, Lawrence B. [Chemical Sciences and Engineering; Georgievskii, Yuri [Chemical Sciences and Engineering; Klippenstein, Stephen J. [Chemical Sciences and Engineering; Wagner, Albert F. [Chemical Sciences and Engineering

    2018-02-03

    Monte Carlo phase space integration (MCPSI) is used to compute full dimensional and fully anharmonic, but classical, rovibrational partition functions for 22 small- and medium-sized molecules and radicals. Several of the species considered here feature multiple minima and low-frequency nonlocal motions, and efficiently sampling these systems is facilitated using curvilinear (stretch, bend, and torsion) coordinates. The curvilinear coordinate MCPSI method is demonstrated to be applicable to the treatment of fluxional species with complex rovibrational structures and as many as 21 fully coupled rovibrational degrees of freedom. Trends in the computed anharmonicity corrections are discussed. For many systems, rovibrational anharmonicities at elevated temperatures are shown to vary consistently with the number of degrees of freedom and with temperature once rovibrational coupling and torsional anharmonicity are accounted for. Larger corrections are found for systems with complex vibrational structures, such as systems with multiple large-amplitude modes and/or multiple minima.

  12. 15 Years of Research on Redirected Walking in Immersive Virtual Environments

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Peck, Tabitha; Bruder, Gerd

    2018-01-01

    Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment—a techn......—a technique called redirected walking. This paper gives an overview of the research that has been performed since redirected walking was first practically demonstrated 15 years ago.......Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment...

  13. 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.

  14. Threat, fear, and persuasion: review and critique of questions about functional form

    OpenAIRE

    Shen, Lijiang; Dillard, James Price

    2014-01-01

    Theories of threat appeals have been rightly concerned with the form of the relationship between fear and persuasion: Linear or curvilinear. They have not, however, clearly distinguished the question as a between- or within-persons phenomenon. In fact, the literature often treats these two perspectives as if they were interchangeable. We show that between- versus within-person questions about functional form are distinct from one another. Previous research, which is the product of between-pe...

  15. Uniqueness in the inverse boundary value problem for piecewise homogeneous anisotropic elasticity

    OpenAIRE

    Cârstea, Cătălin I.; Honda, Naofumi; Nakamura, Gen

    2016-01-01

    Consider a three dimensional piecewise homogeneous anisotropic elastic medium $\\Omega$ which is a bounded domain consisting of a finite number of bounded subdomains $D_\\alpha$, with each $D_\\alpha$ a homogeneous elastic medium. One typical example is a finite element model with elements with curvilinear interfaces for an ansiotropic elastic medium. Assuming the $D_\\alpha$ are known and Lipschitz, we are concerned with the uniqueness in the inverse boundary value problem of identifying the ani...

  16. 境界層遷移予測システムの開発

    OpenAIRE

    Nomura, Toshiyuki; 野村 聡幸

    2000-01-01

    A system for prediction of boundary-layer transition is developed which consists of the Navier-Stokes code, two kinds of codes based on the linear Parabolized Stability Equations (PSE), and the e(exp N)-method code. The prediction system is formulated in generalized curvilinear coordinates, which makes the system applicable to practical configurations. The system is used to predict the transition of the boundary layer of an infinite swept cylinder placed in a supersonic flow. The results obta...

  17. Multibusiness firms and performance in Italy. What role does relatedness play?

    OpenAIRE

    Maurizio La Rocca; Tiziana La Rocca; F. Javier Sánchez Vidal

    2018-01-01

    This paper evaluates the effect of diversification strategy on corporate value for a sample of Italian companies. It accounts for both the level of diversification and relatedness components. Empirical analyses show a U-shaped curvilinear relationship between diversification and value. In contrast to the mainstream literature, our results highlight that related diversification has a negative effect, while unrelated diversification is a value-creating strategy. JEL classification: L25, M10, K...

  18. Innovating tree plantation design: spiralographing agroforestry

    OpenAIRE

    Palma, J.H.N.; Crous-Duran, J.; Merouani, H.; Paulo, J.A.; Tomé, M.

    2014-01-01

    Poster Most of forestry or agroforestry artificial plantations either have an orthogonal design, or curvilinear under contour lines to prevent soil erosion. These designs are known to maximize machinery workflow or erosion control respectively. As in many occasions in land use management, what optimizes machinery operation is not what optimizes prevention of soil loss and vice versa. An alternative and intermediate design system such as an Archimedes spiral could offer ...

  19. Rules for integrals over products of distributions from coordinate independence of path integrals

    International Nuclear Information System (INIS)

    Kleinert, H.; Chervyakov, A.

    2001-01-01

    In perturbative calculations of quantum-mechanical path integrals in curvilinear coordinates, one encounters Feynman diagrams involving multiple temporal integrals over products of distributions which are mathematically undefined. In addition, there are terms proportional to powers of Dirac δ-functions at the origin coming from the measure of path integration. We derive simple rules for dealing with such singular terms from the natural requirement of coordinate independence of the path integrals. (orig.)

  20. Manipulator for plasma-assisted machining of components made of materials with low machinability

    International Nuclear Information System (INIS)

    Lyaoshchukov, M.M.; Agadzhanyan, R.A.

    1984-01-01

    The All-Union Scientific-Research and Technological Institute of Pump Engineering developed, and the ''Uralgidromash'' Production Association has adopted, a manipulator with remote control for the plasma-assisted machining (PAM) of components made of materials with low machinability. The manipulator is distinguished by its universal design and can be used for machining both external and internal surfaces of the bodies of revolution and also end faces and various curvilinear surfaces

  1. 15 Years of Research on Redirected Walking in Immersive Virtual Environments.

    Science.gov (United States)

    Nilsson, Niels Christian; Peck, Tabitha; Bruder, Gerd; Hodgson, Eri; Serafin, Stefania; Whitton, Mary; Steinicke, Frank; Rosenberg, Evan Suma

    2018-03-01

    Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment-a technique called redirected walking. This paper gives an overview of the research that has been performed since redirected walking was first practically demonstrated 15 years ago.

  2. Network Characteristics and the Value of Collaborative User-Generated Content

    OpenAIRE

    Sam Ransbotham; Gerald C. Kane; Nicholas H. Lurie

    2012-01-01

    User-generated content is increasingly created through the collaborative efforts of multiple individuals. In this paper, we argue that the value of collaborative user-generated content is a function both of the direct efforts of its contributors and of its embeddedness in the content-contributor network that creates it. An analysis of Wikipedia's WikiProject Medicine reveals a curvilinear relationship between the number of distinct contributors to user-generated content and viewership. A two-...

  3. Unusual Thymic Hyperplasia Mimicking Lipomatous Tumor in an Eight-Year-Old Boy with Concomitant Pericardial Lipomatosis and Right Facial Hemihypertrophy

    International Nuclear Information System (INIS)

    Kim, Yoo Jin; Kim Woo Sun; Cheon, Jung Eun; Lim, Yun Jung; Kim, In One; Yeon, Kyung Mo; Jung, Kyeong Cheon; Byun, Sun Ju

    2011-01-01

    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.

  4. Nonlinear interaction of waves in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    Istomin, Ya.N.

    1988-01-01

    Nonlinear wave processes in a weakly inhomogeneous plasma are considered. A quasilinear equation is derived which takes into account the effect of the waves on resonance particles, provided that the inhomogeneity appreciably affects the nature of the resonance interaction. Three-wave interaction is investigated under the same conditions. As an example, the nonlinear interaction in a relativistic plasma moving along a strong curvilinear magnetic field is considered

  5. Tectolinear interpretation of a 1:5,000,000 Landsat-1 mosaic compared with the structure of central and eastern United States

    Science.gov (United States)

    Kutina, Jan; Carter, William D.

    1978-01-01

    The pattern of lineaments and curvilinear features interpreted from a 1:5,000,000 mosaic of satellite images (Landsat-1 was superimposed on a simplified version of the Geological Map of the United States, 1:2,500,000 scale, showing the structural scheme of Central and Eastern United States. A comparison of the above two patterns, shown in Fig. 1, is presented in this paper.

  6. The disposition index does not reflect β-cell function in IGT subjects treated with pioglitazone.

    Science.gov (United States)

    DeFronzo, Ralph A; Tripathy, Devjit; Abdul-Ghani, Muhammad; Musi, Nicolas; Gastaldelli, Amalia

    2014-10-01

    The insulin secretion/insulin resistance (IR) (disposition) index (ΔI/ΔG ÷ IR, where Δ is change from baseline, I is insulin, and G is glucose) is commonly used as a measure of β-cell function. This relationship is curvilinear and becomes linear when log transformed. ΔI is determined by 2 variables: insulin secretion rate (ISR) and metabolic clearance of insulin. We postulated that the characteristic curvilinear relationship would be lost if Δ plasma C-peptide (ΔCP) (instead of Δ plasma insulin) was plotted against insulin sensitivity. A total of 441 individuals with impaired glucose tolerance (IGT) from ACT NOW received an oral glucose tolerance test and were randomized to pioglitazone or placebo for 2.4 years. Pioglitazone reduced IGT conversion to diabetes by 72% (P < .0001). ΔI/ΔG vs the Matsuda index of insulin sensitivity showed the characteristic curvilinear relationship. However, when ΔCP/ΔG or ΔISR/ΔG was plotted against the Matsuda index, the curvilinear relationship was completely lost. This discordance was explained by 2 distinct physiologic effects that altered plasma insulin response in opposite directions: 1) increased ISR and 2) augmented metabolic clearance of insulin. The net result was a decline in the plasma insulin response to hyperglycemia during the oral glucose tolerance test. These findings demonstrate a physiologic control mechanism wherein the increase in ISR ensures adequate insulin delivery into the portal circulation to suppress hepatic glucose production while delivering a reduced but sufficient amount of insulin to peripheral tissues to maintain the pioglitazone-mediated improvement in insulin sensitivity without excessive hyperinsulinemia. These results demonstrate the validity of the disposition index when relating the plasma insulin response to insulin sensitivity but underscore the pitfall of this index when drawing conclusions about β-cell function, because insulin secretion declined despite an increase in the

  7. 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.

  8. Splitting of inviscid fluxes for real gases

    Science.gov (United States)

    Liou, Meng-Sing; Van Leer, Bram; Shuen, Jian-Shun

    1990-01-01

    Flux-vector and flux-difference splittings for the inviscid terms of the compressible flow equations are derived under the assumption of a general equation of state for a real gas in equilibrium. No necessary assumptions, approximations for auxiliary quantities are introduced. The formulas derived include several particular cases known for ideal gases and readily apply to curvilinear coordinates. Applications of the formulas in a TVD algorithm to one-dimensional shock-tube and nozzle problems show their quality and robustness.

  9. Methods for Analysis and Simulation of Ballistic Impact

    Science.gov (United States)

    2017-04-01

    carbide. All experiments were conducted in reverse mode [7], with long- rod hypervelocity impact and penetration into confined cylindrical ceramic...comprehensive treatment that encompasses curvilinear coordinates, see [17], with general kinematics addressed in more detail in [49]. Governing equations of...deformation and mechanically reversible changes in damage (e.g., elastic crack closure on load release), J accounts for plastic slip from dislocations

  10. Relationship between Income and Subjective Economic Well-Being: Absolute or Relative?

    Directory of Open Access Journals (Sweden)

    V A Khashchenko

    2012-09-01

    Full Text Available The article considers the role of the absolute and relative income in determining the subjective economic well-being. It is shown that the relationship of the income to SEB is curvilinear with the increase of marginal utility for a higher income. At low income levels its effect on SEB is determined not by its absolute, but by its relative value based on the comparisons with the subjective standards of well-being.

  11. Solution of volume-surface integral equations using higher-order hierarchical Legendre basis functions

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav

    2007-01-01

    The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...... with the analytical Mie series solution. Scattering by more complex metal-dielectric objects are also considered to compare the presented technique with other numerical methods....

  12. 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.

  13. Vibration-rotation band intensities in the IR spectra of polyatomic molecules

    International Nuclear Information System (INIS)

    El'kin, M.D.; Kosterina, E.K.; Berezin

    1995-01-01

    Using the curvilinear vibrational coordinates for a nuclear subsystem, expressions for the effective dipole-moment operators are derived in order to analyze the vibrational-rotational transitions in the IR spectra of polyatomic rigid molecules. The explicit expressions obtained for the intensities of hot bands allow one to estimate the influence of the vibration-rotation interaction within the framework of the adopted molecular-vibration model. The suggested method is shown to be suitable for Raman spectra analysis. 12 refs

  14. 15 Years of Research on Redirected Walking in Immersive Virtual Environments

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Peck, Tabitha; Bruder, Gerd

    2018-01-01

    Virtual reality users wearing head-mounted displays can experience the illusion of walking in any direction for infinite distance while, in reality, they are walking a curvilinear path in physical space. This is accomplished by introducing unnoticeable rotations to the virtual environment......—a technique called redirected walking. This paper gives an overview of the research that has been performed since redirected walking was first practically demonstrated 15 years ago....

  15. FDTD Stability: Critical Time Increment

    OpenAIRE

    Z. Skvor; L. Pauk

    2003-01-01

    A new approach suitable for determination of the maximal stable time increment for the Finite-Difference Time-Domain (FDTD) algorithm in common curvilinear coordinates, for general mesh shapes and certain types of boundaries is presented. The maximal time increment corresponds to a characteristic value of a Helmholz equation that is solved by a finite-difference (FD) method. If this method uses exactly the same discretization as the given FDTD method (same mesh, boundary conditions, order of ...

  16. Wavefront-ray grid FDTD algorithm

    OpenAIRE

    ÇİYDEM, MEHMET

    2016-01-01

    A finite difference time domain algorithm on a wavefront-ray grid (WRG-FDTD) is proposed in this study to reduce numerical dispersion of conventional FDTD methods. A FDTD algorithm conforming to a wavefront-ray grid can be useful to take into account anisotropy effects of numerical grids since it features directional energy flow along the rays. An explicit and second-order accurate WRG-FDTD algorithm is provided in generalized curvilinear coordinates for an inhomogeneous isotropic medium. Num...

  17. Transurethral light delivery for prostate photoacoustic imaging

    OpenAIRE

    Lediju Bell, Muyinatu A.; Guo, Xiaoyu; Song, Danny Y.; Boctor, Emad M.

    2015-01-01

    Photoacoustic imaging has broad clinical potential to enhance prostate cancer detection and treatment, yet it is challenged by the lack of minimally invasive, deeply penetrating light delivery methods that provide sufficient visualization of targets (e.g., tumors, contrast agents, brachytherapy seeds). We constructed a side-firing fiber prototype for transurethral photoacoustic imaging of prostates with a dual-array (linear and curvilinear) transrectal ultrasound probe. A method to calculate ...

  18. 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.

  19. Acoustic Communications Considerations for Collaborative Simultaneous Localization and Mapping

    Science.gov (United States)

    2014-12-01

    Mission Operations (NEEMO) off the coast of Key Largo, Florida, in September 2013. The mission used the REMUS vehicles to map a simulated asteroid ...Simplifications and assumptions about sound propagation in one area of the world may not hold true for another area simply based on physical conditions...rays follows a curvilinear path as previously discussed in Section II.B.3. If , at the point of transmission, we consider the acoustic message to be a

  20. Amélioration de l'estimation de la densité maximale de peuplement combinant la loi de taille-densité selon Reineke au niveau de production, à l'exemple de l'épicéa commun (Picea abies L. (Karst.)) et du hêtre (Fagus sylvatica L.)

    OpenAIRE

    Schütz , Jean-Philippe; Zingg , Andreas

    2010-01-01

    International audience; The Reineke Stand density rule relating stem numbers to the quadratic mean diameter is generally used as a reference for modelling maximal stand density.* The linearity of this relationship after double logarithmic transformation is generally assumed, but it must be questioned for untouched stands and stands with a conventional thinning regime. Curvilinearity is demonstrated for some spruce and beech stands in Switzerland and shown to be statistically representative. T...