Are the determinants of vertebral endplate changes and severe disc degeneration in the lumbar spine the same? A magnetic resonance imaging study in middle-aged male workers

Directory of Open Access Journals (Sweden)

Korpelainen Raija

2008-04-01

Full Text Available Abstract Background Modic changes are bone marrow lesions visible in magnetic resonance imaging (MRI, and they are assumed to be associated with symptomatic intervertebral disc disease, especially changes located at L5-S1. Only limited information exists about the determinants of Modic changes. The objective of this study was to evaluate the determinants of vertebral endplate (Modic changes, and whether they are similar for Modic changes and severe disc degeneration focusing on L5-S1 level. Methods 228 middle-aged male workers (159 train engineers and 69 sedentary factory workers from northern Finland underwent sagittal T1- and T2-weighted MRI. Modic changes and disc degeneration were analyzed from the scans. The participants responded to a questionnaire including items of occupational history and lifestyle factors. Logistic regression analysis was used to evaluate the associations between selected determinants (age, lifetime exercise, weight-related factors, fat percentage, smoking, alcohol use, lifetime whole-body vibration and Modic type I and II changes, and severe disc degeneration (= grade V on Pfirrmann's classification. Results The prevalences of the Modic changes and severe disc degeneration were similar in the occupational groups. Age was significantly associated with all degenerative changes. In the age-adjusted analyses, only weight-related determinants (BMI, waist circumference were associated with type II changes. Exposure to whole-body vibration, besides age, was the only significant determinant for severe disc degeneration. In the multivariate model, BMI was associated with type II changes at L5-S1 (OR 2.75 per one SD = 3 unit increment in BMI, and vibration exposure with severe disc degeneration at L5-S1 (OR 1.08 per one SD = 11-year increment in vibration exposure. Conclusion Besides age, weight-related factors seem important in the pathogenesis of Modic changes, whereas whole-body vibration was the only significant determinant

Evaluation of sclerosis in Modic changes of the spine using susceptibility-weighted magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Böker, Sarah M., E-mail: Sarah-maria.boeker@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Bender, Yvonne Y., E-mail: Yi-na.bender@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Adams, Lisa C., E-mail: Lisa.adams@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Fallenberg, Eva M., E-mail: Eva.fallenberg@charite.de [Department of Radiology, Charité, Augustenburger Platz 1, 13353 Berlin (Germany); Wagner, Moritz, E-mail: Moritz.wagner@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Hamm, Bernd, E-mail: Bernd.hamm@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany); Makowski, Marcus R., E-mail: Marcus.makowski@charite.de [Department of Radiology, Charité, Charitéplatz 1, 10117 Berlin (Germany)

2017-03-15

Highlights: • SWMR allows a reliable detection of sclerosis in Modic changes. • SWI has a better accuracy for detection of sclerosis in Modic changes than T1/T2w MR. • By applying SWMR the use of additional CT/radiography can be minimized. - Abstract: Purpose: To evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SWMR) for the differentiation of sclerotic and non-sclerotic Modic changes (MC) of the spine compared to computed tomography (CT) and radiographs. Materials and methods: The Institutional Ethics-Review-Board approved this prospective study in advance. Written consent was obtained from all subjects. SWMR and standard T1/T2 MR of the cervical (n = 21) and/or lumbar spine (n = 34) were performed in 54 patients. 21 patients served as control. 18 patients were evaluated with CT; in all other patients radiographs were available. 67 Modic changes were identified on T1/T2 MR. On SWMR changes were classified as sclerotic and non-sclerotic based on signal intensity measurements. The sensitivity and specificity of SWMR and T1/T2 MR for differentiating between sclerotic and non-sclerotic Modic changes were determined with CT and radiographs as reference standard. Results: On SWMR, signal measurements between sclerotic and non-sclerotic Modic changes differed significantly (p < 0.01). On T1- and T2-weighted MR no significant difference (p > 0.05) was measured. On SWMR, a reliable differentiation between sclerotic and non-sclerotic Modic changes could be achieved, with a sensitivity of 100% and specificity of 95%. In contrast, the combination of T1-/T2-weighted MR yielded a significantly lower sensitivity to detect sclerosis (20%). Conclusion: SWMR allows a reliable detection of sclerosis in Modic changes with a higher accuracy compared to standard spine MR sequences, using radiographs and CT as reference standard.

Type II Modic Changes May not Always Represent Fat Degeneration: A Study Using MR Fat Suppression Sequence.

Science.gov (United States)

Feng, Zhiyun; Liu, Yuanhao; Wei, Wei; Hu, Shengping; Wang, Yue

2016-08-15

A radiological study of type II Modic changes (MCs). The aim of this study was to determine the characteristics of type II MCs on fat suppression (FS) magnetic resonance (MR) images and its association with radiological disc degeneration. Type II MCs are common endplate signal changes on MR images. On the basis of limited histological samples, type II MCs are thought to be stable fat degeneration. FS technique on MR, which can quantify fat content, may be an alternative to explore the pathology of MCs. To date, however, the characteristics of type II MCs on FS sequence have not been studied. Lumbar MR images conducted in a single hospital during a defined period were reviewed to include those with type II MCs and FS images. On FS images, signal status of type II MCs was visually classified as suppressed or not-suppressed. Signal intensity of vertebral regions with and without MCs was measured quantitatively on T2-weighted (T2W) and FS images to calculate fat content index and validate the visual classification. Using image analysis program Osirix, MCs size and adjacent disc degeneration were measured quantitatively. Paired t-tests and logistic regressions were used to determine the associations studied. Sixty-four lumbar MRIs were included and 150 endplates with type II MCs were studied. Although signal of 37 (24.7%) type II MCs was suppressed on FS images, that of 113 (75.3%) was not suppressed. The discs adjacent to type II MCs had lower signal intensity (0.13 ± 0.003 vs. 0.14 ± 0.004, P Type II MCs that were not suppressed on FS image were associated with greater age [odds ratio (OR) = 1.11, P type II MCs was not suppressed on FS MR images, suggesting that there are ongoing complicated pathologies. Type II MCs may not merely represent fat replacement. 3.

Correlação entre as classificações de Pfirrmann e Modic na degeneração do disco intervertebral lombar Correspondencia entre las clasificaciones de Pfirrmann y Modic en la degeneración del disco intervertebral lumbar Correlation between Pfirrmann and Modic classifications in the degeneration of lumbar intervertebral disc

Directory of Open Access Journals (Sweden)

Marcio Squassoni Leite

2010-12-01

con Pfirrmann tipo V, y el 36,4% de las alteraciones Modic 1 fueron por igual entre Pfirrmann tipo IV y V. Se encontró una asociación estadísticamente significativa entre los cambios de Modic y Pfirrmann (pOBJECTIVE: to correlate the changes found in the lumbar magnetic resonance imaging according to Modic and Pfirrmann classifications. METHODS: lumbar spine resonances of 54 outpatients were selected (23 men and 31 women, who were already under investigation because of their comorbidity. According to their degree of Pfirrmann classification, 264 intervertebral discs (L1 to S1 were classified. The presence of signal abnormalities of the vertebral body was recorded as Modic classification. The χ2 mwas applied, adopting significance levels below 0.05 (a=5%. RESULTS: The mean age studied was of 48.4 years (26-77 years. A higher prevalence of Pfirrmann type IV (31.1% was observed. In 88.3% of the sample, Modic was absent, and also Modic 3; 60% of Modic 2 was related to Pfirrmann type V, and 36.4% of Modic 1 was equally distributed among Pfirrmann type IV and V. Statistically significant association between Modic changes and Pfirrmann (p<0.001 was found. CONCLUSION: there was a clear association between the classifications studied, comparing the stages of Pfirrmann (IV and V with Modic type 1 and 2.

Refined Phenotyping of Modic Changes

Science.gov (United States)

Määttä, Juhani H.; Karppinen, Jaro; Paananen, Markus; Bow, Cora; Luk, Keith D.K.; Cheung, Kenneth M.C.; Samartzis, Dino

2016-01-01

Abstract Low back pain (LBP) is the world's most disabling condition. Modic changes (MC) are vertebral bone marrow changes adjacent to the endplates as noted on magnetic resonance imaging. The associations of specific MC types and patterns with prolonged, severe LBP and disability remain speculative. This study assessed the relationship of prolonged, severe LBP and back-related disability, with the presence and morphology of lumbar MC in a large cross-sectional population-based study of Southern Chinese. We addressed the topographical and morphological dimensions of MC along with other magnetic resonance imaging phenotypes (eg, disc degeneration and displacement) on the basis of axial T1 and sagittal T2-weighted imaging of L1-S1. Prolonged severe LBP was defined as LBP lasting ≥30 days during the past year, and a visual analog scale severest pain intensity of at least 6/10. An Oswestry Disability Index score of 15% was regarded as significant disability. We also assessed subject demographics, occupation, and lifestyle factors. In total, 1142 subjects (63% females, mean age 53 years) were assessed. Of these, 282 (24.7%) had MC (7.1% type I, 17.6% type II). MC subjects were older (P = 0.003), had more frequent disc displacements (P disability. The strength of the associations increased with the number of MC. This large-scale study is the first to definitively note MC types and specific morphologies to be independently associated with prolonged severe LBP and back-related disability. This proposed refined MC phenotype may have direct implications in clinical decision-making as to the development and management of LBP. Understanding of these imaging biomarkers can lead to new preventative and personalized therapeutics related to LBP. PMID:27258491

Modic changes and associated features in Southern European chronic low back pain patients.

Science.gov (United States)

Arana, Estanislao; Kovacs, Francisco M; Royuela, Ana; Estremera, Ana; Asenjo, Beatriz; Sarasíbar, Helena; Amengual, Guillermo; Galarraga, Isabel; Alonso, Ana; Casillas, Carlos; Muriel, Alfonso; Montoya, Julia; Ordóñez, Cristina; Martínez, Carmen; Zamora, Javier; Campillo, Carlos; Abraira, Víctor

2011-05-01

Conflicting reports exist regarding the prevalence of Modic changes among low back pain (LBP) patients and factors associated with their existence. To assess the prevalence of Modic changes and other findings on lumbar magnetic resonance imaging (MRI) among Spanish adult chronic LBP patients and the patient characteristics and radiological findings associated with Modic changes. A cross-sectional imaging study among chronic LBP patients. Four hundred eighty-seven patients (263 women and 224 men) undergoing lumbar spine MRI examination for chronic LBP. Gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, and image features (disc degeneration, type and extension of Modic changes, disc contour, annular tears, spinal stenosis, and spondylolisthesis). Ten radiologists from six hospitals across six cities in Spain consecutively recruited adult patients in whom lumbar MRI had been prescribed for LBP lasting ≥3 months. Patients' characteristics and imaging findings were assessed through previously validated instruments. A multivariate logistic regression model was developed to assess the features associated with Modic changes. Modic changes were found in 81% of the patients. The most common was Type II (51.3%), affecting only the end plate. Variables associated with Type I changes were disc contour abnormalities, spondylolisthesis, and disc degeneration. The same variables were associated with a higher risk of Type II or any type of Modic changes, as well as being male, and having a higher BMI. Modic changes are found in 81% (95% confidence interval, 77-85) of adult Spanish patients in whom an MRI is prescribed for chronic LBP. Modic changes are more likely to be found in males with a high BMI, who also show disc contour abnormalities, spondylolisthesis, or disc degeneration. Copyright © 2011 Elsevier Inc. All rights reserved.

PEM Low Cost Endplates. Final report

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Martin; Clyens, S.; Steenstrup, F.R.; Christiansen, Jens [Danish Technological Institute. Plastics Technology, Taastrup (Denmark); Yde-Andersen, S. [IRD Fuel Cell A/S, Svendborg (Denmark)

2013-03-15

In the project, an endplate for the PEM-type fuel cells has been developed. The initial idea was to use an injection mouldable fibre reinforced polymer to produce the endplate and thereby exploit the opportunities of greater geometrical freedom to reduce weight and material consumption. Different PPS/glass-fibre compounds were produced and tested in order to use the results to optimize the results on the computer through FEM simulations. As it turned out, it was impossible to achieve adequate stiffness for the endplates within the given geometrical limitations. At the relatively high temperatures at which the endplates operate the material simply goes to soft. Material focus shifted to fibre reinforced high strength concrete composite. Test specimens were produced and tested so the results again could be used for FEM-simulations which also accounted for the technical limitations the concrete composite has regarding casting ability. In the process, the way the endplate is mounted was also alternated to better accommodate the properties of the concrete composite. A number of endplates were cast in specially produced moulds in order to map the optimum process parameters, and a final endplate was tested at IRD Fuel Cells A/S. The field test was in many aspects successful. However, the gas sealing and the surface finish can be further improved. The weight may still be an issue for some applications, even though it is lower than the endplate currently used. This issue can be addressed in a future project. The work has resulted in a new endplate design, which makes the stack assembly simpler and with fewer components. The endplates fabrication involves low cost methods, which can be scaled up as demand of fuel cells begin to take off. (Author)

The association between Modic changes and pain during 1-year follow-up in patients with lumbar radicular pain

International Nuclear Information System (INIS)

Schistad, Elina Iordanova; Roee, Cecilie; Espeland, Ansgar; Rygh, Lars Joergen; Gjerstad, Johannes

2014-01-01

To examine whether Modic changes influence pain during a 1-year follow-up in patients with lumbar radicular pain. A total of 243 patients with lumbar radicular pain due to disc herniation were recruited from two hospitals in Norway and followed up at 6 weeks, 6 months, and 12 months. On baseline lumbar magnetic resonance images, two observers independently evaluated Modic changes (types I-III; craniocaudal size 0-3). Outcomes were sensory pain (McGill Pain Questionnaire), back and leg pain (visual analogue scale, VAS). Association between Modic type and outcomes was explored with a mixed model and then by two-way analysis of variance (ANOVA) at each time point with Modic and treatment groups (surgical, n = 126; nonsurgical, n = 117) as fixed factors, adjusted for disc degeneration, age, sex, smoking, and duration of radicular pain. Modic size was also analyzed using ANOVA. Pain scores had decreased significantly at 1-year follow-up. Modic type was significantly related to McGill sensory scores (mixed model: p = 0.014-0.026; ANOVA: p = 0.007 at 6 weeks), but not to VAS back pain or VAS leg pain scores. At 6 weeks, the mean McGill sensory score was higher in Modic I than in Modic II-III patients (p = 0.003) and in patients without Modic changes (p = 0.018). Modic size L1-S1 was not associated with pain outcomes. Patients with lumbar radicular pain have a substantial pain reduction during 1-year follow-up, but Modic type I changes may imply a slower initial decrease in sensory pain. (orig.)

The association between Modic changes and pain during 1-year follow-up in patients with lumbar radicular pain

Energy Technology Data Exchange (ETDEWEB)

Schistad, Elina Iordanova; Roee, Cecilie [Oslo University Hospital, Department of Physical Medicine and Rehabilitation, Ullevaal, Nydalen, Postbox 4956, Oslo (Norway); University of Oslo, Faculty of Medicine, Oslo (Norway); Espeland, Ansgar [Haukeland University Hospital, Department of Radiology, Bergen (Norway); University of Bergen, Section for Radiology, Department of Clinical Medicine, Bergen (Norway); Rygh, Lars Joergen [Haukeland University Hospital, Department of Anesthesiology, Bergen (Norway); Gjerstad, Johannes [National Institute of Occupational Health, Oslo (Norway); University of Oslo, Department of Molecular Biosciences, Oslo (Norway)

2014-09-15

To examine whether Modic changes influence pain during a 1-year follow-up in patients with lumbar radicular pain. A total of 243 patients with lumbar radicular pain due to disc herniation were recruited from two hospitals in Norway and followed up at 6 weeks, 6 months, and 12 months. On baseline lumbar magnetic resonance images, two observers independently evaluated Modic changes (types I-III; craniocaudal size 0-3). Outcomes were sensory pain (McGill Pain Questionnaire), back and leg pain (visual analogue scale, VAS). Association between Modic type and outcomes was explored with a mixed model and then by two-way analysis of variance (ANOVA) at each time point with Modic and treatment groups (surgical, n = 126; nonsurgical, n = 117) as fixed factors, adjusted for disc degeneration, age, sex, smoking, and duration of radicular pain. Modic size was also analyzed using ANOVA. Pain scores had decreased significantly at 1-year follow-up. Modic type was significantly related to McGill sensory scores (mixed model: p = 0.014-0.026; ANOVA: p = 0.007 at 6 weeks), but not to VAS back pain or VAS leg pain scores. At 6 weeks, the mean McGill sensory score was higher in Modic I than in Modic II-III patients (p = 0.003) and in patients without Modic changes (p = 0.018). Modic size L1-S1 was not associated with pain outcomes. Patients with lumbar radicular pain have a substantial pain reduction during 1-year follow-up, but Modic type I changes may imply a slower initial decrease in sensory pain. (orig.)

Modic changes of the cervical spine: T1 slope and its impact on axial neck pain.

Science.gov (United States)

Li, Jia; Qin, Shuhui; Li, Yongqian; Shen, Yong

2017-01-01

The purpose of the research was to evaluate cervical sagittal parameters on magnetic resonance imaging (MRI) in patients with Modic changes and its impact on axial neck pain. This study consisted of 266 consecutive asymptomatic or symptomatic patients with Modic changes, whose average age was 50.9±12.6 years from January 2015 to December 2016. Cervical sagittal parameters included sagittal alignment of the cervical spine (SACS), T1 slope, thoracic inlet angle (TIA), and neck tilt (NT). The Modic changes group was compared with an asymptomatic control group of 338 age- and gender-matched adults. In the Modic changes group, T1 slope was significantly higher (25.8°±6.3°) compared with that in the control group (22.5°±6.8°) ( P =0.000). However, there was no significant difference of the NT, TIA, and SACS between the two groups. Patients in the Modic changes group were more likely to have experienced historical axial neck pain compared with the control group ( P =0.000). With regard to the disc degeneration, it indicated that the disc in the Modic changes group had more severe disc degeneration ( P =0.032). T1 slope in the Modic changes group was significantly higher compared to that of the control group. The findings suggested that a higher T1 slope with broken compensation of cervical sagittal mechanism may be associated with the development of Modic changes in the cervical spine.

Modic changes and their associations with clinical findings

DEFF Research Database (Denmark)

Kjær, Per; Korsholm, Lars; Bendix, Tom

2006-01-01

It is believed that disc degeneration (DD) is, in general, only mildly associated with low back pain (LBP). MRI-identified Modic changes (MC), probably a late stage of DD, are relatively strongly associated with LBP but it is not known if people with MC also have a specific clinical profile. The ...... around the disc in relation to LBP, history, and clinical findings. People with DD and no MC only vaguely differ from those without. People with LBP and MC may deserve to be diagnosed as having specific LBP.......It is believed that disc degeneration (DD) is, in general, only mildly associated with low back pain (LBP). MRI-identified Modic changes (MC), probably a late stage of DD, are relatively strongly associated with LBP but it is not known if people with MC also have a specific clinical profile....... The purpose of this study was to investigate if the clinical findings differ in people with Modic changes (MC) as compared to those with only degenerative disc findings or none at all. In a population-based sample of 412 40-year-old Danes, information was collected independently with MRI, questionnaires...

Modic changes of the cervical spine in patients with whiplash injury: a prospective 11-year follow-up study.

Science.gov (United States)

Matsumoto, Morio; Ichihara, Daisuke; Okada, Eijiro; Toyama, Yoshiaki; Fujiwara, Hirokazu; Momoshima, Suketaka; Nishiwaki, Yuji; Takahata, Takeshi

2013-06-01

There are few studies on Modic changes of the cervical spine in patients suffering from whiplash. This study compared Modic changes seen in whiplash patients 10 years after the injury with those observed in asymptomatic volunteers. This is a follow-up study of 133 patients who suffered whiplash injuries in 1994-1996 and underwent MRI with a superconductive imager (63 men, 70 women, mean age 49.6±15.3 years, mean follow-up 11.4 years). In addition, 223 healthy volunteers who underwent MRI during the same period were included as controls (123 men, 100 women, mean age 50.5±15.0 years, mean follow-up 11.6 years). All participants underwent follow-up MRI. We examined all participants for Modic changes, and investigated relationships between Modic changes and clinical symptoms or potentially related factors. Modic changes were observed in 4 patients (3%) and at 7 intervertebral levels in the initial study, and in 17 patients (12.8%) and at 30 intervertebral levels at the follow-up. Modic Type 2 changes were the most prevalent in the whiplash patients in both the initial and follow-up studies. There was no significant difference in the percentage of whiplash patients versus control subjects with positive Modic changes, either at the initial study or at follow-up. Modic changes were not related to clinical symptoms present at follow-up, but were associated with preexisting disc degeneration. There was no association between Modic changes and the details of the car accident that caused the injury. While Modic changes became more common in whiplash patients in the 10-year period after the accident, they occurred with a similar frequency in control subjects. We did not find any association between Modic changes and the nature of the car accident in which the whiplash occurred. Modic changes found in whiplash patients may be a result of the physiological ageing process rather than pathological findings relating to the whiplash injury. Copyright © 2012 Elsevier Ltd. All

Octanol reduces end-plate channel lifetime

Science.gov (United States)

Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk

1978-01-01

1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that

Multimodal advanced imaging of the spine

International Nuclear Information System (INIS)

Tanenbaum, L.

2015-01-01

Full text: DWI is a powerful addition to the arsenal of MR imaging techniques for the detection of bone marrow tumor dissemination, improving sensitivity to involvement in a variety of tumor types. DWI increases confidence in monitoring treatment response and assisting in the differentiation of treatment related changes from tumor. DWI has also become an important component of whole-body MR oncology protocols. Distinguishing between benign and malignant etiologies of vertebral fracture with MRI is problematic, particularly if only one vertebra is affected. the value of DWI in discriminating between osteoporotic and metastatic vertebral fractures is controversial and by consensus insufficiently reliable. DWI is useful for differentiation of degenerative and infectious endplate abnormalities. Symptomatic degenerative vertebral endplate signal changes (Modic type 1) can be difficult to differentiate from acute spondylodiscitis using conventional MRI techniques. Several studies have shown that DWI adds value in differentiating degenerative and infectious endplate abnormalities. Recently a characteristic DWI finding of well-marginated, linear, typically paired regions of high signal at the interface of normal with abnormal marrow, referred to as a ‘claw’ sign, is been shown to be highly suggestive of degeneration and its absence in cases with Modic type I changes suggestive of diskitis/osteomyelitis. the value of excluding the possibility of infection can be seen in reduction in unnecessary, often invasive ancillary testing and reduced levels of patient concern. DWI may also yield insight into intervertebral disc degeneration. It has recently been shown in the lumbar spine that disc degeneration can influence ADC values with negative correlation between ADC and the degree of disc degeneration

Thoracic spine disc-related abnormalities: longitudinal MR imaging assessment

Energy Technology Data Exchange (ETDEWEB)

Girard, Charles J.; Schweitzer, Mark E.; Morrison, William B.; Parellada, Joan A. [TJUH Radiology, Philadelphia, Pennsylvania (United States); Carrino, J.A. [Department of Radiology ASB-1, Harvard Medical School, Brigham and Women' s Hospital, L1, Room 002B, 75 Francis Street, MA 02115, Boston (United States)

2004-04-01

To describe and characterize the temporal changes in disc-related disorders of the thoracic spine using MR imaging. A retrospective longitudinal cohort study was carried out of 40 patients with two sequential thoracic spine MR images at variable intervals. The images were assessed for baseline presence of, new incidence of and changes in disc herniation, degenerative disc disease, endplate marrow signal alteration and Schmorl nodes. The range of follow-up was 4-149 weeks. Baseline presence was: disc herniation, 10% (49/480); degenerative disc disease, 14% (66/480); endplate marrow signal alteration, 2.3% (11/480); Schmorl nodes 9.6% (46/480). Most pre-existing lesions tended to remain unchanged. Herniations showed the most change, tending to improve in 27%. New incidence was: disc herniation, 1.5% (7/480), degenerative disc disease, 2% (10/480); endplate marrow signal alteration, 1.6% (8/480); Schmorl nodes, 2.1% (10/480). Disc degeneration was first visible at an 11-week interval and once established almost never changed over many weeks to months. Endplate signal alterations (Modic changes) were uncommon. Schmorl nodes show no change from baseline for up to 2 1/2 years. All findings predominated in the lower intervertebral levels from T6 to T10. The most prevalent thoracic spine disc-related findings are degeneration and herniation. Disc herniations predominate in the lower segments and are a dynamic phenomenon. Disc degeneration can be rapidly evolving but tends to remain unchanged after occurrence. Endplate marrow signal changes were an uncommon manifestation of thoracic disc disease. Schmorl nodes showed the least change over time. (orig.)

Dynamic Stabilisation in the Treatment of Degenerative Disc Disease with Modic Changes

Directory of Open Access Journals (Sweden)

Olcay Eser

2013-01-01

Full Text Available Objective. Posterior dynamic stabilization is an effective alternative to fusion in the treatment of chronic instability and degenerative disc disease (DDD of the lumbar spine. This study was undertaken to investigate the efficacy of dynamic stabilization in chronic degenerative disc disease with Modic types 1 and 2. Modic types 1 and 2 degeneration can be painful. Classic approach in such cases is spine fusion. We operated 88 DDD patients with Modic types 1 and 2 via posterior dynamic stabilization. Good results were obtained after 2 years of followup. Methods. A total of 88 DDD patients with Modic types 1 and 2 were selected for this study. The patients were included in the study between 2004 and 2010. All of them were examined with lumbar anteroposterior (AP and lateral X-rays. Lordosis of the lumbar spine, segmental lordosis, and ratio of the height of the intervertebral disc spaces (IVSs were measured preoperatively and at 3, 12, and 24 months after surgery. Magnetic resonance imaging (MRI analysis was carried out, and according to the data obtained, the grade of disc degeneration was classified. The quality of life and pain scores were evaluated by visual analog scale (VAS score and Oswestry Disability Index (ODI preoperatively and at 3, 12, and 24 months after surgery. Appropriate statistical method was chosen. Results. The mean 3- and 12-month postoperative IVS ratio was significantly greater than that of the preoperative group (P0.05. Furthermore, the mean preoperative and 1 and 2 postoperative angles of lumbar lordosis and segmental lordosis were not significantly different (P>0.05. The mean VAS score and ODI, 3, 12, and 24 months after surgery, decreased significantly, when compared with the preoperative scores in the groups (P=0.000. Conclusion. Dynamic stabilization in chronic degenerative disc disease with Modic types 1 and 2 was effective.

Association between nutritional status and Modic classification in degenerative disc disease.

Science.gov (United States)

Seyithanoglu, Hakan; Aydin, Teoman; Taşpınar, Ozgur; Camli, Adil; Kiziltan, Huriye; Eris, Ali Hikmet; Hocaoglu, Ilknur Turk; Ozder, Aclan; Denizli, Ebru; Kepekci, Muge; Keskin, Yasar; Mutluer, Ahmet Serdar

2016-04-01

[Purpose] This study was conducted to examine the association between Modic classification and the eating habits in patients with degenerative disc disease (DDD) and to determine the influence of nutrition on disease severity. [Subjects and Methods] Sixty patients with DDD visiting a low back pain outpatient clinic were enrolled. Through face-to-face interviews, they completed questionnaires regarding their demographics, disease activity, smoking and alcohol use, concomitant diseases, disease duration, and nutritional status.Exclusion criteria were age 65 years, other comorbidities, missing MRI data, and inability to speak Turkish. [Results] Forty patients were finally included in the study. The frequency with which they consumed water, salt, fast food, eggs, milk, yogurt, cheese, whole wheat bread, white bread, butter, and margarine was recorded. A weak negative correlation was observed between the Modic types and fish and egg consumption. [Conclusion] Modic changes, which indicate the severity of DDD, seem to be correlated to patients' dietary habits. However, studies with comparison groups and larger samples are needed to confirm our promising results before any cause-and-effect relationship can be proposed.

Endplates Changes Related to Age and Vertebral Segment

Directory of Open Access Journals (Sweden)

Carlos Fernando P. S. Herrero

2014-01-01

Full Text Available Endplate separations are defined as the presence of a space between the hyaline cartilage and the cortical bone of the adjacent vertebral body. This study evaluates endplate separations from the vertebral body and intervertebral discs and verifies if endplate separation is related to age and the spinal level. Groups were formed based on age (20–40 and 41–85 years old and the vertebral segment (T7-T8 and L4-L5 segments. Histological analysis included assessment of the length of the vertebral endplates, the number and dimensions of the separations, and orientation of the collagen fibers, in the mid-sagittal slice. Two indexes were created: the separation index (number of separations/vertebral length and separation extension index (sum of all separations/vertebral length. The results of the study demonstrated a direct relationship between the density of separations in the endplate and two variables: age and spinal level.

Characteristics of Modic changes in cervical kyphosis and their association with axial neck pain.

Science.gov (United States)

An, Yonghui; Li, Jia; Li, Yongqian; Shen, Yong

2017-01-01

The purpose of this study was to evaluate characteristics of Modic changes in cervical kyphosis (CK) and their association with axial neck pain. Study participants included 286 asymptomatic or symptomatic patients with CK (mean age = 54.2 ± 12.2 years) who were consecutively enrolled from March 2009 to October 2015. Clinical and radiographic evaluations were performed at a university outpatient department. CK was classified as global type, reverse sigmoid type, or sigmoid type. There were 138 participants with global type CK, 103 with reverse sigmoid type CK, and 45 with sigmoid type CK. Of the 286 participants, 102 had Modic changes (Modic-1 in 38 segments and Modic-2 in 75 segments). Spinal cord compression grade and disc degeneration occurred more frequently in the group with axial neck pain compared to the group without pain. Angular motion was decreased in those with axial neck pain (mean ± standard deviation [SD] 7.8°±4.6°) compared to those who were asymptomatic (mean ± SD 8.9°±5.1°; P pain (odds ratio =5.356; 95% confidence interval =1.314-12.800; P pain in patients with CK.

Cervical endplate and facet arthrosis: an anatomic study of cadaveric specimens.

Science.gov (United States)

Master, Daniel L; Toy, Jason O; Eubanks, Jason D; Ahn, Nicholas U

2012-10-01

An anatomic, epidemiologic study of cervical endplate and facet arthrosis in cadaveric spines. To determine the prevalence of cervical endplate and facet arthrosis and the relationship between these 2 entities in a large population sample. Cervical endplate and facet arthrosis are common radiographic findings, which have both been linked to pain. However, the prevalence and relationship between cervical endplate and facet arthrosis has not been clearly defined. The cervical vertebrae from 234 cadaveric spines were examined by a single investigator for evidence of endplate and facet arthrosis. Arthrosis at each endplate and facet was graded on a continuum from 0 to IV. Race, age at death, and sex of each specimen were also recorded. Stepwise multiple linear regression was used to analyze any association between race, age, sex, endplate arthrosis, and facet arthrosis. Factors with P values arthrosis severity scores among patients within the same decades of life. Concurrent cervical endplate and facet arthrosis was present in 77% of the study population. Stepwise multiple linear regression revealed significant (Parthrosis and between age and facet arthrosis. Race and sex did not correlate with facet arthrosis. In addition, patients in age groups 30 to 39, 40 to 49, 50 to 59, 60 to 69, 70 to 79, and 80 to 89 demonstrated more severe (Parthrosis in comparison with facet arthrosis. Concurrent cervical endplate and facet arthrosis is a common condition. Cervical endplate arthrosis and advancing age are associated with cervical facet arthrosis independent of race and sex. Cervical endplate arthrosis precedes facet arthrosis.

Antibiotic treatment in patients with chronic low back pain and vertebral bone edema (Modic type 1 changes)

DEFF Research Database (Denmark)

Albert, H. B.; Sørensen, Joan S.; Berit Schiott, Christensen

2013-01-01

PURPOSE: Modic type 1 changes/bone edema in the vertebrae are present in 6 % of the general population and 35-40 % of the low back pain population. It is strongly associated with low back pain. The aim was to test the efficacy of antibiotic treatment in patients with chronic low back pain (>6...... months) and Modic type 1 changes (bone edema). METHODS: The study was a double-blind RCT with 162 patients whose only known illness was chronic LBP of greater than 6 months duration occurring after a previous disc herniation and who also had bone edema demonstrated as Modic type 1 changes...

Do positive MRI findings in the lumbar spine predict future seeking care for low back pain in young teenagers?

DEFF Research Database (Denmark)

Kjær, Per; Leboeuf-Yde, Charlotte; Korsholm, Lars

Background: In MRI studies lumbar disk degeneration and endplate changes have been found in children and adolescents. Such MRI findings appear to be more strongly associated with LBP than in adults. However, this knowledge is mainly based on cross-sectional studies from which no inferences regarded......, nucleus form, annular tears, high intensity zones, bulging, herniation, nerve root compression, endplate changes, Modic changes, and spondylolisthesis). Associations were sought through logistic regression at each lumbar level for boys and girls separately. Statistically significant results were presented......, and annular tears and bulging at L4. Moderate predictors included reduced signal L1 and L4, disk herniation and nerve root compression L4. Other levels and findings showed no statistically significant associations. Interestingly, the areas with the fewest findings showed the strongest associations to seeking...

Mechanisms of initial endplate failure in the human vertebral body.

Science.gov (United States)

Fields, Aaron J; Lee, Gideon L; Keaveny, Tony M

2010-12-01

Endplate failure occurs frequently in osteoporotic vertebral fractures and may be related to the development of high tensile strain. To determine whether the highest tensile strains in the vertebra occur in the endplates, and whether such high tensile strains are associated with the material behavior of the intervertebral disc, we used micro-CT-based finite element analysis to assess tissue-level strains in 22 elderly human vertebrae (81.5 ± 9.6 years) that were compressed through simulated intervertebral discs. In each vertebra, we compared the highest tensile and compressive strains across the different compartments: endplates, cortical shell, and trabecular bone. The influence of Poisson-type expansion of the disc on the results was determined by compressing the vertebrae a second time in which we suppressed the Poisson expansion. We found that the highest tensile strains occurred within the endplates whereas the highest compressive strains occurred within the trabecular bone. The ratio of strain to assumed tissue-level yield strain was the highest for the endplates, indicating that the endplates had the greatest risk of initial failure. Suppressing the Poisson expansion of the disc decreased the amount of highly tensile-strained tissue in the endplates by 79.4 ± 11.3%. These results indicate that the endplates are at the greatest risk of initial failure due to the development of high tensile strains, and that such high tensile strains are associated with the Poisson expansion of the disc. We conclude that initial failure of the vertebra is associated with high tensile strains in the endplates, which in turn are influenced by the material behavior of the disc. Copyright © 2010 Elsevier Ltd. All rights reserved.

Study of Enzymatic Degradation Comparison of CPP/Bionolle and CPP/PCL Blend with Modic

International Nuclear Information System (INIS)

Nikham; Makuuchi, K.; Yoshii, Fumeo

2000-01-01

Melt-blending poly propylene-co-ethylene (CPP)/poly butylene succinate (Bionolle), CPP/polyεcaprolactone (PCL) with polypropylene grafted maleic anhydride (Modic) as compatibilizer has been studied. The effect of Modic concentration on the compatibility was evaluated using the ultimate elongation at break, tensile strength and SEM micrographs. The Result show that 20 wt % and 10 % wt of Medic appears to be an optimum concentration for CPP/Bionolle and CPP/PCL blend respectively, as indicated by relatively high elongation at breaks, tensile strength and formation of co-continuous phase in the blend morphology. Enzymatic degradation of the CPP/Bionolle and CPP/PCL blend with 10 wt % of Modic was carried out using lipase AK enzyme in the phospate buffer solution pH 7.0 and incubated at the fixed temperature for 8 days. The result show that about 15 % and 86 % weight loss film of composition CPP/Bionolle>25/75 and CPP/PCL >25/75 blend respectively has been reached

Significance of angular mismatch between vertebral endplate and prosthetic endplate in lumbar total disc replacement.

Science.gov (United States)

Lee, Chong Suh; Chung, Sung Soo; Oh, Sung Kyun; You, Je Wook

2011-05-01

A retrospective study. To determine whether angular mismatch between the vertebral endplate and prosthetic endplate during lumbar total disc replacement (L-TDR) affects the radiological and clinical outcomes. A prosthesis anchored to the vertebral body by using a large central keel carries an inherent risk of angular mismatch between the vertebral endplate and prosthetic endplate at a segment with a greater degree of lordosis, such as L5-S1. Theoretically, this angular mismatch can cause several problems, such as segmental hyperlordosis, anterior positioning of the upper prosthesis, posterior prosthetic edge subsidence, decreased range of motion (ROM), and a poor clinical outcome. This study evaluated 64 prosthetic levels of 56 patients who were implanted with L-TDR between June 2002 and February 2006. There were 38 and 26 prosthetic levels at the L4-5 and L5-S1, respectively. The mean follow-up period was 25.6 (12 to 49) months. The angle of mismatch between the lower endplate of the upper vertebral body and the upper prosthetic plate, segmental flexion/extension ROM, segmental lordosis angle at extension, distance from the posterior wall of the vertebral body to the posterior prosthetic edge were measured by obtaining radiographs. Clinically, the Visual Analogue Scale and Oswestry Disability Index were also evaluated. The angular mismatches between the upper vertebra and prosthesis at L4-5 and L5-S1 were 1.6 degree and 5.6 degree, respectively (P body to the posterior edge of the prosthesis in L5-S1 were 6.8 degree (4 to 13), 12.8 degree (8 to 17), and 3.8 mm (1 to 6 mm) in patients with an angular mismatch of 0.05). Angular mismatch was more common in L5-S1 than in L4-5. L-TDR at the most lordotic level, L5-S1, and implantation of an upper prosthesis with a mismatched angle seem to be the causes of a reduced segmental ROM, increased segmental lordosis, and anterior malpositioning of the prosthesis. However, these changes do not affect the clinical outcomes of

Antibiotics in the treatment of patients with lower back pain associated with Modic changes: a case series.

Science.gov (United States)

Gupta, Gaurav; Jarzem, Peter; Meredith, Sean; Radhakrishna, Mohan; Besemann, Markus; Elgueta, Maria Francisca; Charghi, Roshanak; Chankowsky, Jeffrey

2017-01-01

To determine the clinical effect of antibiotic treatment for patients with low back pain and Modic 1 changes. This is a retrospective case series of patients treated at the Canadian Forces Health Services Centre in Ottawa and the McGill University Health Centre. Where available, pain, functional, and imaging outcomes in 11 patients treated between 2013 and 2015 were analyzed to determine effect of antibiotic treatment for patients with low back pain and associated Modic 1 changes on magnetic resonance imaging. Conservatively, only 3 of 11 patients met the criteria for improvement for pain and/or function. While a larger proportion improved in the long term, outcomes were not thought to be temporally attributable to antibiotic treatment, as in most cases, ongoing therapy, medications, and/or injections were required. There did not appear to be a correlation between clinical improvement and associated end plate volume involvement for Modic changes. Antibiotics for the treatment of low back pain in the context of Modic changes on MRI did not generally provide significant improvement in pain and function for patients in this small cohort. Despite early excitement regarding this treatment, further research is required.

Endplate effect on aerodynamic characteristics of three-dimensional wings in close free surface proximity

Directory of Open Access Journals (Sweden)

Jae Hwan Jung

2012-12-01

Full Text Available We investigated the aerodynamic characteristics of a three-dimensional (3D wing with an endplate in the vicinity of the free surface by solving incompressible Navier-Stokes equations with the turbulence closure model. The endplate causes a blockage effect on the flow, and an additional viscous effect especially near the endplate. These combined effects of the endplate significantly reduce the magnitudes of the velocities under the lower surface of the wing, thereby enhancing aerodynamic performance in terms of the force coefficients. The maximum lift-to-drag ratio of a wing with an endplate is increased 46% compared to that of wing without an endplate at the lowest clearance. The tip vortex of a wing-with-endplate (WWE moved laterally to a greater extent than that of a wing-without-endplate (WOE. This causes a decrease in the induced drag, resulting in a reduction in the total drag.

Behaviour of High Strength Steel Endplate Connections in Fire and after Fire

NARCIS (Netherlands)

Qiang, X.

2013-01-01

The aim of this research is to reveal more information and understanding on behaviour and failure mechanisms of high strength steel endplate connections (combining high strength steel endplates with either mild steel or high strength steel beams and columns in endplate connections) in fire and after

No Evidence for Presence of Bacteria in Modic Type I Changes

DEFF Research Database (Denmark)

Wedderkopp, Niels; Thomsen, Karsten; Manniche, Claus

2008-01-01

Background: Recent studies suggest an association between sciatica and Propionibacterium acnes. "Modic type I changes" in the vertebrae are closely associated with sciatica and lower back pain, and recent studies have questioned the ability of conventional magnetic resonance imaging (MRI...

The effect of papaine on the time course of the end-plate current.

Science.gov (United States)

Humar, M; Kordas, M; Melik, Z

1980-07-01

Papaine is known to detach cholinesterases from the synaptic cleft. It could be expected that this would result in an increase of the amplitude and half-time of the end-plate current. Thus, the effect of papaine on the end-plate current. Thus, the effect of papaine on the end-plate current should be similar to the effect of anticholinesterase methanesulfonylfluoride. The end-plate current was recorded in frog skeletal muscle at various levels of membrane potential, before and after papaine was added to the bath. The effect of papaine was an increase of the half-time of the end-plate current, similarly as after treatment of the muscle by methanesulfonylfluoride. It seems that both papaine and methanesulfonylfluoride have a similar mechanism of action. In either experimental condition hydrolysis of transmitter is decreased or abolished, which results in an increase of the half-time of the end-plate current.

Performance assessment on high strength steel endplate connections after fire

NARCIS (Netherlands)

Qiang, X.; Wu, N.; Jiang, X.; Bijlaard, F.S.K.; Kolstein, M.H.

2017-01-01

Purpose – This study aims to reveal more information and understanding on performance and failure mechanisms of high strength steel endplate connections after fire. Design/methodology/approach – An experimental and numerical study on seven endplate connections after

Back Pain and Modic

DEFF Research Database (Denmark)

Manniche, Claus; Jordan, Alan; Mikkelsen, Connie

Long awaited breakthrough Approximately 25 years ago a few researchers managed to publish an article in the renowned medical journal, The Lancet. The article demonstrated that intensive exercise was most useful for patients with chronic back pain. Many of our colleagues found this difficult...... to accept, nonetheless, intensive exercise has for chronic back pain has spread across the world and has become – in different forms – the most commonly prescribed treatment for back pain patients. Since that time, there has not been much research based progress in back science, however, we have taken...... a significant step forward with the advent of the new back pain diagnosis, ”Modic changes”. During the coming years, thousands of back pain patients will now be given a precise diagnosis as well as a useful treatment in cases where we previously we unable to provide either a diagnosis or a useful treatment...

Rest versus exercise as treatment for patients with low back pain and Modic changes. A randomised controlled clinical trial

DEFF Research Database (Denmark)

Jensen, Rikke Krüger; Leboeuf-Yde, Charlotte; Wedderkopp, Niels

2012-01-01

pathology, Modic changes might be a diagnostic subgroup that does not benefit from exercise. The objective of this study was to compare the current state-of-the art treatment approach (exercise and staying active) with a new approach (load reduction and daily rest) for people with Modic changes using......ABSTRACT: BACKGROUND: Clinical experience suggests that many patients with Modic changes have relatively severe and persistent low back pain (LBP), which typically appears to be resistant to treatment. Exercise therapy is the recommended treatment for chronic LBP, however due to their underlying...... or exercise therapy once a week for 10 weeks. Follow-up was at 10 weeks after recruitment and 52 weeks after intervention and the clinical outcome measures were pain, disability, general health and global assessment, supplemented by weekly information on low back problems and sick leave measured by short text...

Application of a semiautomatic classifier for modic and disk hernia changes in magnetic resonance

Directory of Open Access Journals (Sweden)

Eduardo López Arce Vivas

2015-03-01

Full Text Available OBJECTIVE: Early detection of degenerative changes in lumbar intervertebral disc by magnetic resonance imaging in a semiautomatic classifier for prevention of degenerative disease. METHOD: MRIs were selected with a diagnosis of degenerative disc disease or back pain from January to May 2014, with a sample of 23 patients and a total of 170 disks evaluated by sagittal T2 MRI image, first evaluated by a specialist physician in training and them were introduced into the software, being the results compared. RESULTS: One hundred and fifteen discs were evaluated by a programmed semiautomatic classifier to identify MODIC changes and hernia, which produced results "normal or MODIC" and "normal or abnormal", respectively. With a total of 230 readings, of which 141 were correct, 84 were reading errors and 10 readings were undiagnosed, the semiautomatic classifier is a useful tool for early diagnosis or established disease and is easy to apply because of the speed and ease of use; however, at this early stage of development, software is inferior to clinical observations and the results were from around 65% to 60% certainty for MODIC rating and 61% to 58% for disc herniation, compared with clinical evaluations. CONCLUSION: The comparative results between the two doctors were 94 consistent results and only 21 errors, which represents 81% certainty.

Antibiotic treatment in patients with low-back pain associated with Modic changes Type 1 (bone oedema): a pilot study

DEFF Research Database (Denmark)

Albert, HB; Manniche, C; Sørensen, JS

2008-01-01

OBJECTIVE: The aim of this study was to assess the clinical effect of antibiotic treatment in a cohort of patients with low-back pain (LBP) and Modic changes Type 1 (bone oedema) following a lumbar herniated disc. DESIGN: This was a prospective uncontrolled trial of 32 LBP patients who had Modic...... and LBP at 14 months follow-up (n = 37) were invited to participate in this subsequent antibiotic trial but five did not meet the inclusion criteria. RESULTS: 29 patients completed the treatment, as three patients dropped out due to severe diarrhoea. At the end of treatment and at long-term follow...... changes and were treated with Amoxicillin-clavulanate (500 mg/125 mg) 3 x day for 90 days. All patients had previously participated in a randomised controlled trial (RCT) that investigated active conservative treatment for a lumbar herniated disc (n = 166). All patients in that RCT who had Modic changes...

Rest versus exercise as treatment for patients with low back pain and Modic changes. a randomized controlled clinical trial

Directory of Open Access Journals (Sweden)

Jensen Rikke K

2012-02-01

Full Text Available Abstract Background Clinical experience suggests that many patients with Modic changes have relatively severe and persistent low back pain (LBP, which typically appears to be resistant to treatment. Exercise therapy is the recommended treatment for chronic LBP, however, due to their underlying pathology, Modic changes might be a diagnostic subgroup that does not benefit from exercise. The objective of this study was to compare the current state-of-the art treatment approach (exercise and staying active with a new approach (load reduction and daily rest for people with Modic changes using a randomized controlled trial design. Methods Participants were patients from an outpatient clinic with persistent LBP and Modic changes. They were allocated using minimization to either rest therapy for 10 weeks with a recommendation to rest for two hours daily and the option of using a flexible lumbar belt or exercise therapy once a week for 10 weeks. Follow-up was at 10 weeks after recruitment and 52 weeks after intervention and the clinical outcome measures were pain, disability, general health and global assessment, supplemented by weekly information on low back problems and sick leave measured by short text message (SMS tracking. Results In total, 100 patients were included in the study. Data on 87 patients at 10 weeks and 96 patients at one-year follow-up were available and were used in the intention-to-treat analysis. No statistically significant differences were found between the two intervention groups on any outcome. Conclusions No differences were found between the two treatment approaches, 'rest and reduced load' and 'exercise and staying active', in patients with persistent LBP and Modic changes. Trial Registration ClinicalTrials.gov: NCT00454792

Research progress of aluminium alloy endplates for PEMFCs

Energy Technology Data Exchange (ETDEWEB)

Fu, Yu.; Hou, Junbo [Fuel Cell system and Engineering Laboratory, Dalian Institute of Chemical and Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Hou, Ming; Yan, Xiqiang; Luo, Xiaokuan; Shao, Zhigang; Yi, Baolian [Fuel Cell system and Engineering Laboratory, Dalian Institute of Chemical and Physics, Chinese Academy of Sciences, Dalian 116023 (China)

2007-04-15

The endplate is a crucial component in a proton exchange membrane fuel cell (PEMFC) stack. It can provide the necessary rigidity and strength for the stack. An aluminium alloy is one of the ideal materials for PEMFC endplates because of its low density and high rigidity. But it does not meet the requirements of corrosion resistance and electrical insulation in PEMFC environments. In this work, methods of sealing treatments and the conditions of aluminium alloy anodization were investigated. Corrosion resistances of the samples prepared by different technologies were evaluated in simulated PEMFC environments. The results showed that the corrosion resistance of the samples sealed by epoxy resin was greatly improved compared with those sealed in boiling water, and the samples anodized at a constant current density performed better than those anodized at a constant voltage. By insulation measurements, all of the samples showed good electrical insulation. The aluminium alloy endplate anodized at a constant current density and sealed with thermosetting bisphenol-A epoxy resin exhibited promising potential for practical applications by assembling it in a PEMFC stack and applying a life test. (author)

Do MRI findings identify patients with chronic low back pain and Modic changes who respond best to rest or exercise

DEFF Research Database (Denmark)

Jensen, Rikke K; Kent, Peter; Hancock, Mark

2015-01-01

BACKGROUND: No previous clinical trials have investigated MRI findings as effect modifiers for conservative treatment of low back pain. This hypothesis-setting study investigated if MRI findings modified response to rest compared with exercise in patients with chronic low back pain and Modic...... changes. METHODS: This study is a secondary analysis of a randomised controlled trial comparing rest with exercise. Patients were recruited from a specialised outpatient spine clinic and included in a clinical trial if they had chronic low back pain and an MRI showing Modic changes. All patients received...... or with large Modic changes Type 1 were all potentially important in size (-0.99 (95 % CI -3.28 to 1.29), -1.49 (-3.73 to 0.75), -1.49 (-3.57 to 0.58), respectively) but the direction of the effect was the opposite to what we had hypothesized-that people with these findings would benefit more from rest than...

Numerical Study on Ultimate Behaviour of Bolted End-Plate Steel Connections

Directory of Open Access Journals (Sweden)

R.E.S. Ismail

Full Text Available Abstract Bolted end-plate steel connections have become more popular due to ease of fabrication. This paper presents a three dimension Finite Element Model (FEM, using the multi-purpose software ABAQUS, to study the effect of different geometrical parameters on the ultimate behavior of the connection. The proposed model takes into account material and geometrical non-linearities, initial imperfection, contact between adjacent surfaces and the pretension force in the bolts. The Finite Element results are calibrated with published experimental results ''briefly reviewed in this paper'' and verified that the numerical model can simulate and analyze the overall and detailed behavior of different types of bolted end-plate steel connections. Using verified FEM, parametric study is then carried out to study the ultimate behavior with variations in: bolt diameter, end-plate thickness, length of column stiffener, angle of rib stiffener. The results are examined with respect to the failure modes, the evolution of the resistance, the initial stiffness, and the rotation capacity. Finally, the ultimate behavior of the bolted end-plate steel connection is discussed in detail, and recommendations for the design purpose are made.

Lumbar Modic Changes - A Comparison Between Findings at Low-and High-field MRI

DEFF Research Database (Denmark)

Bendix, Tom; Sorensen, Joan S; Henriksson, Gustaf A C

2012-01-01

Study Design. A cross-sectional observational study.Objective. To investigate if there is a difference in findings of lumbar Modic changes in low-field (0.3 Tesla) magnetic resonance imaging (MRI) as compared to high field (1.5 Tesla).Summary of Background Data. It is a challenge to give patients...

Technical Support of Performance Improvement for Resistance Welding Using Zr-4 Endcap and Endplate

Energy Technology Data Exchange (ETDEWEB)

Kim, Soo Sung

2008-10-15

The proper welding process for Zircaloy-4 endplate of PHWR and DUPIC fuel bundle assembly is considered important in respect to the soundness of weldment and the improvement of the performance of nuclear fuel bundle during the operation in reactor. The Zircaloy-4 endplate of PHWR and DUPIC fuel bundles are welded by the projection joint type, connecting the endcaps of fuel elements. Therefore, the purpose of this projection joint is to improve the welding quality of torque strength and welding deformation and to apply the commercial productions for the endplate welding of PHWR and DUPIC nuclear fuel bundle assembly.

Finite element analysis of an extended end-plate connection using the T-stub approach

Energy Technology Data Exchange (ETDEWEB)

Muresan, Ioana Cristina; Balc, Roxana [Technical University of Cluj-Napoca, Faculty of Civil Engineering. 15 C Daicoviciu Str., 400020, Cluj-Napoca (Romania)

2015-03-10

Beam-to-column end-plate bolted connections are usually used as moment-resistant connections in steel framed structures. For this joint type, the deformability is governed by the deformation capacity of the column flange and end-plate under tension and elongation of the bolts. All these elements around the beam tension flange form the tension region of the joint, which can be modeled by means of equivalent T-stubs. In this paper a beam-to-column end-plate bolted connection is substituted with a T-stub of appropriate effective length and it is analyzed using the commercially available finite element software ABAQUS. The performance of the model is validated by comparing the behavior of the T-stub from the numerical simulation with the behavior of the connection as a whole. The moment-rotation curve of the T-stub obtained from the numerical simulation is compared with the behavior of the whole extended end-plate connection, obtained by numerical simulation, experimental tests and analytical approach.

Evaluation of intravertebral changes associated with the disk degeneration based on the MRI findings

International Nuclear Information System (INIS)

Saiki, Natoru

2000-01-01

The magnetic resonance images (MRI) of 441 vertebral bodies of the 199 patients with intravertebral abnormality associated with adjacent disk degeneration were evaluated according to the Modic classification and a new geographic classification. They were also evaluated in relation with the various factors including disk space narrowing, vacuum phenomenon, disk herniation, Schmorl's node, ostephyte formation and spondylolisthesis. The new geographic classification is based on the three factors; depth of invasion: stage 1 (thin layer along the end-plate), stage 2 (less than a half of the vertebral height) and stage 3 (more than a half of the vertebral height), shape: end-plate type, Schmorl's node type, triangle type, meniscus type and band type, location: front type, center type, rear type, front and rear type and whole type. Only about a half of the vertebral bodies with intervertebral abnormality showed bilateral invasion adjacent to the degenerative disks on both sides and the superior edges were much more frequently involved than the inferior ones. There was relatively higher incidence (7%) of Modic Type I degeneration defined as high signal intensity (HSI) on T2 weighted spin-echo images (T2WI) and low signal intensity (LSI) on T1 weighted spin-echo images (T1WI) representing vascularized fibrous tissue than those previously reported. On the other hand there was relatively lower incidence (5%) of Modic Type II degeneration defined as high or iso intensity on T1WI and HSI on T2WI. Triangle front type was seen in almost a half of the vertebrae in stage 2 and stage 3, and the rest was divided into meniscus type and band type almost evenly. The end plate front type must be a precursor of the triangle front type. The Schmorl's node type was considered to be a precursor of the meniscus type as well as band type in some but many must stay in its form transformed to Type II degeneration. In general, the intravertebral abnormality may not be necessary to be progressive

Influence of cortical endplates on ultrasonic properties of trabecular bone

International Nuclear Information System (INIS)

Kim, Yoon Mi; Lee, Kang Il

2015-01-01

The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

Back pain's association with vertebral end-plate signal changes in sciatica.

Science.gov (United States)

el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; van der Kallen, Bas F; Lycklama à Nijeholt, Geert J; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

2014-02-01

Patients with sciatica frequently experience disabling back pain. One of the proposed causes for back pain is vertebral end-plate signal changes (VESC) as visualized by magnetic resonance imaging (MRI). To report on VESC findings, changes of VESC findings over time, and the correlation between VESC and disabling back pain in patients with sciatica. A randomized clinical trial with 1 year of follow-up. Patients with 6 to 12 weeks of sciatica who participated in a multicenter, randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. Patients were assessed by means of the 100-mm visual analog scale (VAS) for back pain (with 0 representing no pain and 100 the worst pain ever experienced) at baseline and 1 year. Disabling back pain was defined as a VAS score of at least 40 mm. Patients underwent MRI both at baseline and after 1 year follow-up. Presence and change of VESC was correlated with disabling back pain using chi-square tests and logistic regression analysis. At baseline, 39% of patients had disabling back pain. Of the patients with VESC at baseline, 40% had disabling back pain compared with 38% of the patients with no VESC (p=.67). The prevalence of type 1 VESC increased from 1% at baseline to 35% 1 year later in the surgical group compared with an increase from 3% to 11% in the conservative group. The prevalence of type 2 VESC decreased from 40% to 29% in the surgical group while remaining almost stable in the conservative group at 41%. The prevalence of disabling back pain at 1 year was 12% in patients with no VESC at 1 year, 16% in patients with type 1 VESC, 11% in patients with type 2 VESC, and 3% in patients with both types 1 and 2 VESC (p=.36). Undergoing surgery was associated with increase in the extent of VESC (odds ratio [OR], 8.6; 95% confidence interval [CI], 4.7-15.7; psciatica was highly associated with the development of VESC after 1 year. However, in contrast with the intuitive feeling

Torque Measurement of Welding of Endplug-Endplate using Multi-pin Remote Welding System

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae-Seo; Kim, Soo-Sung; Park, Geun-Il; Lee, Jung-Won; Song, Kee-Chan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2006-07-01

As fuel bundles in PHWR irradiates, inner pressure in claddings of fuel rods increases owing to outer pressure and fission products of nuclear fissions. Because of leak possibility of welding between cladding and end plug, this welding part connects with safety of nuclear fuel rods. Because of importance of this welding part, weldability of end plug-cladding of nuclear fuel rods is continually researched. Welding method for research and commercialization is classified as melting, solid type welding or resistance welding. End plug cladding welding of nuclear fuel rods in PHWR takes advantage of resistance upset butt welding using multicycle mode. This method makes weld flash and shapes re-entrant corner owing to welding heat due to resistivity, contact resistance of cladding-end plug, and inelasticity deformation due to pressure. Welding part between cladding and end plug receives stresses and makes small cracks. In this study, remote welding system for multi-pin assembly was designed, fabricated and welding specimens of end plug-endplate were made using electrical resistance method. The torques of welding between end plug and endplate were measured. These results on welding current, pressure of main electrode and pressure of branch electrode were analyzed. Weldability between end plug and endplate was confirmed through metallographic examinations. In the future, optimal welding examinations due to welding current, welding pressure and welding time will be performed to improve weldability of end plug-endplate.

Evaluation on vertebral endplate injury and adjacent intervertebral disk injury of patients with osteoporotic vertebral compression fractures by MRI and its clinical significance

International Nuclear Information System (INIS)

Shen Yu; Shen Huiliang; Fang Xiutong; Zhang Wenbo

2012-01-01

Objective: To investigate the relationship between vertebral endplate injury and adjacent intervertebral disk injury of patients with acute or sub-acute osteoporotic vertebral compression fractures (OVC-F) by MRI, and to provide basis for diagnosis of OVCF. Methods: The clinical data of a total of 66 patients with OVCF underwent vertebroplasty (76 fracture of vertebral bodies) were selected. The vertebral endplate injury and adjacent intervertebral disk injury of OVCF patients were detected by MRI. Results: There were 57 vertebral endplate injury in 76 fracture vertebral bodies (75% ). There were only 27 vertebral bodies with vertebral endplate injury in 57 fracture vertebral bodies with endplate injury (47% ), and 22 vertebral with superior and inferior vertebral endplate injury (39% ), and 8 vertebral bodies with inferior vertebral endplate injury (14% ). There were 48 vertebral bodies with intervertebral disc injury in 76 fracture vertebral bodies (63% ). There were 22 intervertebral disc injury located above the fracture of the lumbar spine in 48 vertebral bodies with intervertebral disc injury (45% ), and 19 fracture vertebral bodies with upper and lower intervertebral disc injury (40% ), and 7 intervertebral injuries located below the fracture of the lumbar spine (15% ). Conclusion: Vertebral endplate injury is frequently associated with the adjacent intervertebral disk injury. The clinical diagnosis and treatment should be emphasized in the fracture vertebral endplate damage and adjacent intervertebral disc injury. (authors)

Effects of rocuronium and vecuronium on initial rundown of endplate potentials in the isolated phrenic nerve diaphragm preparation of rats

OpenAIRE

Li, Jun; Liu, Yong-Qin; Zhang, Han-Ting

2013-01-01

Rocuronium and vecuronium, two non-depolarizing neuromuscular blockers, have been widely used in surgery procedures. However, their electrophysiological properties need to be more widely explored. We examined the effects of rocuronium and vecuronium on initial rundown of endplate potential amplitudes in the non-uniform stretched muscle preparation of the rat isolated phrenic nerve diaphragm. More specifically, the endplate potentials were recorded with one microelectrode from a single endplat...

Autophagy Is a Protective Response to the Oxidative Damage to Endplate Chondrocytes in Intervertebral Disc: Implications for the Treatment of Degenerative Lumbar Disc

Directory of Open Access Journals (Sweden)

Ke Chen

2017-01-01

Full Text Available Low back pain (LBP is the leading cause of disability in the elderly. Intervertebral disc degeneration (IDD was considered as the main cause for LBP. Degeneration of cartilaginous endplate was a crucial harmful factor during the initiation and development of IDD. Oxidative stress was implicated in IDD. However, the underlying molecular mechanism for the degeneration of cartilaginous endplate remains elusive. Herein, we found that oxidative stress could induce apoptosis and autophagy in endplate chondrocytes evidenced by western blot analysis, flow cytometry, immunofluorescence staining, GFP-LC3B transfection, and MDC staining. In addition, we also found that the apoptosis of endplate chondrocytes was significantly increased after the inhibition of autophagy by bafilomycin A1 shown by flow cytometry. Furthermore, mTOR pathway upstream autophagy was greatly suppressed suggested by western blot assay. In conclusion, our study strongly revealed that oxidative stress could increase autophagy and apoptosis of endplate chondrocytes in intervertebral disc. The increase of autophagy activity could prevent endplate chondrocytes from apoptosis. The autophagy in endplate chondrocytes induced by oxidative stress was mTOR dependent. These findings might shed some new lights on the mechanism for IDD and provide new strategies for the treatments of IDD.

Behavior of four-bolt extended end-plate connection subjected to lateral loading

Directory of Open Access Journals (Sweden)

Elsayed Mashaly

2011-03-01

Full Text Available A considerable number of literatures have been published on the behavior of end-plate connections in ordinary moment-resisting frames. It was found, experimentally, that this type of connection might act as either a fully-rigid or a semi-rigid connection depending mainly on the thickness of the end plate and the diameter of bolts. In recent years, due to their good ductility and their good ability of energy dissipation, extended end-plate connections are recommended to be widely used in special moment-resisting frames subjected to lateral loads. The purpose of this study is to investigate the effect of both the material and geometric properties of four-bolt extended end-plate connections upon their behavior when subjected to lateral loading. This is done through a parametric study upon a finite element model using the multi-purpose software package ANSYS. The parametric study takes into account 12 parameters which are expected to be effective on the behavior of the studied connection. The results are presented by the relation between the storey drift, which represents the rotation of the connection and the applied lateral load, which simulates the moment on the connection. The results verify that the chosen parameters are considered effective depending on the energy dissipation of the connection.

Effect of prosthesis endplate lordosis angles on L5-S1 kinematics after disc arthroplasty.

Science.gov (United States)

Tsitsopoulos, Parmenion P; Wojewnik, Bartosz; Voronov, Leonard I; Havey, Robert M; Renner, Susan M; Zelenakova, Julia; McIntosh, Braden; Carandang, Gerard; Abjornson, Celeste; Patwardhan, Avinash G

2012-06-01

We hypothesized that L5-S1 kinematics will not be affected by the lordosis distribution between the prosthesis endplates. Twelve cadaveric lumbosacral spines (51.3 ± 9.8 years) were implanted with 6° or 11° prostheses (ProDisc-L) with four combinations of superior/inferior lordosis (6°/0°, 3°/3°, 11°/0°, 3°/8°). Specimens were tested intact and after prostheses implantation with different lordosis distributions. Center of rotation (COR) and range of motion (ROM) were quantified. Six-degree lordosis prostheses (n = 7) showed no difference in flexion-extension ROM, regardless of design (6°/0° or 3°/3°) (p > 0.05). In lateral bending (LB), both designs reduced ROM (p lordosis prostheses (n = 5) showed no difference in flexion-extension ROM for either design (p > 0.05). LB ROM decreased with distributed lordosis prostheses (3°/8°) (p lordosis distribution among the two prosthesis endplates. The ProDisc-L prosthesis design where all lordosis is concentrated in the superior endplate yielded COR locations that were anterior and caudal to intact controls. The prosthesis with lordosis distributed between the two endplates yielded a COR that tended to be closer to intact. Further clinical and biomechanical studies are needed to assess the long-term impact of lordosis angle distribution on the fate of the facet joints.

Is the transport of a gadolinium-based contrast agent decreased in a degenerated or aged disc? A post contrast MRI study.

Directory of Open Access Journals (Sweden)

Marta Tibiletti

Full Text Available A post contrast magnetic resonance imaging study has been performed in a wide population of low back pain patients to investigate which radiological and phenotypic characteristics influence the penetration of the contrast agent in lumbar discs in vivo. 37 patients affected by different pathologies (disc herniation, spondylolisthesis, foraminal stenosis, central canal stenosis were enrolled in the study. The selected population included 26 male and 11 female subjects, with a mean age of 42.4 ± 9.3 years (range 18-60. Magnetic resonance images of the lumbar spine were obtained with a 1.5 T scanner (Avanto, Siemens, Erlangen, Germany with a phased-array back coil. A paramagnetic non-ionic contrast agent was injected with a dose of 0.4 ml/kg. T1-weighted magnetic resonance images were subsequently acquired at 5 time points, 5 and 10 minutes, 2, 4 and 6 hours after injection. Endplates presented clear enhancement already 5 minutes after injection, and showed an increase in the next 2 hours followed by a decrease. At 5 and 10 minutes, virtually no contrast medium was present inside the intervertebral disc; afterwards, enhancement significantly increased. Highly degenerated discs showed higher enhancement in comparison with low and medium degenerated discs. Discs classified as Pfirrmann 5 showed a statistically significant higher enhancement than Pfirrmann 1, 2 and 3 at all time points but the first one, possibly due to vascularization. Disc height collapse and Modic changes significantly increased enhancement. Presence of endplate defects did not show any significant influence on post contrast enhancement, but the lack of a clear classification of endplate defects as seen on magnetic resonance scans may be shadowing some effects. In conclusion, disc height, high level of degeneration and presence of Modic changes are factors which increase post contrast enhancement in the intervertebral disc. The effect of age could not be demonstrated.

Relationship between screw sagittal angle and stress on endplate of adjacent segments after anterior cervical corpectomy and fusion with internal fixation: a Chinese finite element study.

Science.gov (United States)

Zhang, Yu; Tang, Yibo; Shen, Hongxing

2017-12-01

In order to reduce the incidence of adjacent segment disease (ASD), the current study was designed to establish Chinese finite element models of normal 3rd~7th cervical vertebrae (C3-C7) and anterior cervical corpectomy and fusion (ACCF) with internal fixation , and analyze the influence of screw sagittal angle (SSA) on stress on endplate of adjacent cervical segments. Mimics 8.1 and Abaqus/CAE 6.10 softwares were adopted to establish finite element models. For C4 superior endplate and C6 inferior endplate, their anterior areas had the maximum stress in anteflexion position, and their posterior areas had the maximum stress in posterior extension position. As SSA increased, the stress reduced. With an increase of 10° in SSA, the stress on anterior areas of C4 superior endplate and C6 inferior endplate reduced by 12.67% and 7.99% in anteflexion position, respectively. With an increase of 10° in SSA, the stress on posterior areas of C4 superior endplate and C6 inferior endplate reduced by 9.68% and 10.22% in posterior extension position, respectively. The current study established Chinese finite element models of normal C3-C7 and ACCF with internal fixation , and demonstrated that as SSA increased, the stress on endplate of adjacent cervical segments decreased. In clinical surgery, increased SSA is able to play important role in protecting the adjacent cervical segments and reducing the incidence of ASD.

A Relationship of the Torque Strength between Endplates and Endcaps due to the Welding Parameters

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae Seo; Kim, Soo Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-10-15

As fuel bundles in a PHWR core irradiated, inner pressure in the claddings of the fuel rods increases owing to the outer pressure and fission products of the nuclear fissions. Because of a leak possibility from a welding between a cladding and an endcap, this welding part is connected with the safety of nuclear fuel rods. Endcap-cladding welding of nuclear fuel rods in a PHWR takes advantage of a resistance upset butt welding. The weldment between a cladding and an endcap is to be sound to prevent a leakage of fission products from a cladding as a UO{sub 2} pellet is irradiated. Weld flash was made from a deformation due to a welding heat and increasing the pressure of the resistivity and resistance from a cladding and an endcap. Weld line of a welding interface, microstructure of a weldment and a crystallographic structure change were sources of an iodine induced SCC in a reactor. The soundness of a weldment is important because a weld line connects the leakage of fission products from an operational reactor. In this study, welding specimens were fabricated by a resistance welding method using a fuel bundle welder to measure and analyze the torque strength of an endplate-endcap welding. The torque strength between endplates and endcaps was measured and analyzed with the welding current and the welding time. The torque strength between endplates and endcaps was, on the whole, within 6.9-12.7 N{center_dot}m in the range of fabrication specification of the fuel bundles. The weldability of between an endplate and an endcap was investigated by a metallographic examination.

The significance of calcified fibrocartilage on the cortical endplate of the translational sheep spine model.

Science.gov (United States)

Sinclair, Sarina K; Bell, Spencer; Epperson, Richard Tyler; Bloebaum, Roy D

2013-05-01

To gain an understanding of the vertebral cortical endplate and factors that may affect the ability to achieve skeletal attachment to intervertebral implants and fusion, this study aimed to characterize the hypermineralized tissue on the cortical endplate of the vertebral body on a commonly used animal model. Skeletally mature sheep were injected with tetracycline prior to euthanasia and the C2-C3, T5-T6, and L2-L3 spinal motion segments were excised and prepared. Vertebral tissues were imaged using backscatter electron (BSE) imaging, histology, and tetracycline labeling was used to assess bone remodeling within different tissue layers. It was determined that the hypermineralized tissue layer was calcified fibrocartilage (CFC). No tetracycline labels were identified in the CFC layer, in contrast to single and double labels that were present in the underlying bone, indicating the CFC present on the cortical endplate was not being actively remodeled. The average thickness of the CFC layer was 146.3 ± 70.53 µm in the cervical region, 98.2 ± 40.29 µm in the thoracic region, and 150.89 ± 69.25 µm in the lumbar region. This difference in thickness may be attributed to the regional biomechanical properties of the spine. Results from this investigation indicate the presence of a nonremodeling tissue on the cortical endplate of the vertebral body in sheep spines, which attaches the intervertebral disc to the vertebrae. This tissue, if not removed, would likely prevent successful bony attachment to an intervertebral device in spinal fusion studies and total disc replacement surgeries. Copyright © 2013 Wiley Periodicals, Inc.

Association of endothelin-1 expression and cartilaginous endplate degeneration in humans.

Directory of Open Access Journals (Sweden)

Wei Yuan

Full Text Available BACKGROUND: Inflammatory cytokines are involved in intervertebral disc (IVD degeneration. Endothelin-1 (ET-1, a 21-amino-acid cytokine implicated with cartilage degradation, is secreted by vascular endothelial cells and also by many other cell types. The expression of ET-1 in human IVD cartilage endplate (CEP and its role in disc degeneration have not been explored. METHODS AND FINDINGS: The expression of ET-1 in degenerated CEP was analyzed by immunohistochemical staining and Western blotting; ET-1 was demonstrated in cartilaginous endplate cells (CECs by immunofluorescent staining. The ET-1 mRNA expression and protein production by CECs stimulated by tumor necrosis factor alpha (TNF-α, a pro-inflammatory cytokine, were determined by real-time PCR analysis and Western blotting, respectively. The matrix metalloprotease-1 (MMP-1, MMP-13 and tissue inhibitor of metalloproteases-1 (TIMP-1 levels in the supernatant of cultured CECs treated with ET-1 were determined using enzyme-linked immunosorbent assays. Nitric oxide (NO release and nitric oxide synthase (NOS activity were measured using a spectrophotometric assay. The apoptosis of CECs by ET-1 was measured by an Annexin V-FITC detection assay. The production of ET-1 in degenerated cartilage endplate was significantly higher than normal CEP. The results showed that ET-1 was expressed by CECs and modulated by TNF-α in a dose-dependent manner. ET-1 increased production of MMP-1 and MMP-13, decreased TIMP-1 production, and induced NO and NOS release by cultured CECs. The direct stimulation of CECs by ET-1 did not promote cell apoptosis. CONCLUSION: The study results suggest that ET-1 played a pivotal role in human CEP degeneration, and may be a new target for development of therapies for this condition.

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

Is the development of Modic changes associated with clinical symptoms?

DEFF Research Database (Denmark)

Jensen, Rikke Krüger; Leboeuf-Yde, Charlotte; Wedderkopp, Niels

2012-01-01

/or the pathological type of MCs were associated with changes in clinical symptoms in a cohort of patients with persistent LBP and MCs. METHODS: Information on LBP intensity and detailed information from MRI on the presence, type and size of MCs was collected at baseline and follow-up. Changes in type (Type I, II, III...... developmental path from Type I (here Type I or I/II) to Type II (here Type II or II/III) or Type I to Type I/II. In general, the bigger the size of the MC at baseline, the more likely it was that it remained unchanged in size after 14 months. Patients who had MC Type I at both baseline and 14-month follow......PURPOSE: Modic changes (MCs) have been suggested to be a diagnostic subgroup of low back pain (LBP). However, the clinical implications of MCs remain unclear. For this reason, the aims of this study were to investigate how MCs developed over a 14-month period and if changes in the size and...

The MRI appearances of early vertebral osteomyelitis and discitis

International Nuclear Information System (INIS)

Dunbar, J.A.T.; Sandoe, J.A.T.; Rao, A.S.; Crimmins, D.W.; Baig, W.; Rankine, J.J.

2010-01-01

Aim: To describe the magnetic resonance imaging (MRI) appearances in patients with a clinical history suggestive of vertebral osteomyelitis and discitis who underwent MRI very early in their clinical course. Materials and methods: A retrospective review of the database of spinal infections from a spinal microbiological liaison team was performed over a 2 year period to identify cases with clinical features suggestive of spinal infection and an MRI that did not show features typical of vertebral osteomyelitis and discitis. All patients had positive microbiology and a follow up MRI showing typical features of spinal infection. Results: In four cases the features typical of spinal infection were not evident at the initial MRI. In three cases there was very subtle endplate oedema associated with disc degeneration, which was interpreted as Modic type I degenerative endplate change. Intravenous antibiotic therapy was continued prior to repeat MRI examinations. The mean time to the repeat examination was 17 days with a range of 8-22 days. The second examinations clearly demonstrated vertebral osteomyelitis and discitis. Conclusion: Although MRI is the imaging method of choice for vertebral osteomyelitis and discitis in the early stages, it may show subtle, non-specific endplate subchondral changes; a repeat examination may be required to show the typical features.

Relationship of modic type 1 change with disc degeneration: a prospective MRI study

Energy Technology Data Exchange (ETDEWEB)

Luoma, Katariina [Helsinki University Central Hospital, Helsinki and Uudenmaa District University Hospitals, Helsinki (Finland)]|[Peijas Hospital, Helsinki University Central Hospitals, Department of Radiology, Vantaa (Finland); Vehmas, Tapio [Institute of Occupational Health, Helsinki (Finland); Groenblad, Mats; Kaeaepae, Eeva [Helsinki and Uudenmaa District University Hospitals, Helsinki University Central Hospital, Department of Physical Medicine and Rehabilitation, Helsinki (Finland); Kerttula, Liisa [Helsinki University Central Hospital, Helsinki and Uudenmaa District University Hospitals, Helsinki (Finland)

2009-03-15

The objective was to study the natural course of Modic type 1 change (M1) in relation to lumbar disc degeneration. Twenty-four chronic low back pain (LBP) patients with M1 on lumbar spine were selected from 1,015 patients with magnetic resonance imaging from a follow-up study lasting for 18-74 months. Exclusion criteria were any other specific back disorder, age {>=}60 years, or a recent spine operation. The association between the development of M1 and degenerative disc changes was studied using multivariate modeling (complex samples logistic regression). At baseline, 20 of 28 (71%) disc spaces with M1 had a decreased disc height (DH) and 16 of 28 (57%) a dark nucleus pulposus, but ten of 28 (36%) a very dark annulus fibrosus and a paradoxically bright nucleus pulposus albeit decreased DH. During follow-up, DH decreased in 13 of 28 (46%) and signal intensity of nucleus pulposus (DSI) in eight of 28 (29%) disc spaces with M1, but it increased in four (14%) discs. In those without M1, only few changes occurred. The larger the M1, the more likely was the DH low or decreased further. Both the presence and changes in M1 were associated with a decrease in DH and changes in DSI and bulges. The degenerative process in discs with adjacent M1 seems to be accelerated and leads to advanced and deforming changes with special morphologic features. M1 may be a sign of a pathologic degenerative process in the discovertebral unit. (orig.)

Relationship of modic type 1 change with disc degeneration: a prospective MRI study

International Nuclear Information System (INIS)

Luoma, Katariina; Vehmas, Tapio; Groenblad, Mats; Kaeaepae, Eeva; Kerttula, Liisa

2009-01-01

The objective was to study the natural course of Modic type 1 change (M1) in relation to lumbar disc degeneration. Twenty-four chronic low back pain (LBP) patients with M1 on lumbar spine were selected from 1,015 patients with magnetic resonance imaging from a follow-up study lasting for 18-74 months. Exclusion criteria were any other specific back disorder, age ≥60 years, or a recent spine operation. The association between the development of M1 and degenerative disc changes was studied using multivariate modeling (complex samples logistic regression). At baseline, 20 of 28 (71%) disc spaces with M1 had a decreased disc height (DH) and 16 of 28 (57%) a dark nucleus pulposus, but ten of 28 (36%) a very dark annulus fibrosus and a paradoxically bright nucleus pulposus albeit decreased DH. During follow-up, DH decreased in 13 of 28 (46%) and signal intensity of nucleus pulposus (DSI) in eight of 28 (29%) disc spaces with M1, but it increased in four (14%) discs. In those without M1, only few changes occurred. The larger the M1, the more likely was the DH low or decreased further. Both the presence and changes in M1 were associated with a decrease in DH and changes in DSI and bulges. The degenerative process in discs with adjacent M1 seems to be accelerated and leads to advanced and deforming changes with special morphologic features. M1 may be a sign of a pathologic degenerative process in the discovertebral unit. (orig.)

Mechanisms of the inhibition of endplate acetylcholine receptors by antiseptic chlorhexidine (experiments and models)

Czech Academy of Sciences Publication Activity Database

Shaihutdinova, A.R.; Nikolsky, E. E.; Vyskočil, František; Skorinkin, A.I.

2009-01-01

Roč. 380, č. 6 (2009), s. 551-560 ISSN 0028-1298 R&D Projects: GA AV ČR(CZ) IAA500110905 Institutional research plan: CEZ:AV0Z50110509 Keywords : acetylcholine * endplate currents Subject RIV: ED - Physiology Impact factor: 2.631, year: 2009

Torque strength of an endplate welding due to process parameters using a fuel assembling welder

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae-Seo; Kim, Soo-Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-05-15

As fuel bundles in a PHWR core irradiated, inner pressure in the claddings of the fuel rods increases owing to the outer pressure and fission products of the nuclear fissions. Because of a leak possibility from a welding between a cladding and end plug, this welding part is connected with the safety of nuclear fuel rods. Endplug-cladding welding of nuclear fuel rods in a PHWR takes advantage of a resistance upset butt welding. The weldment between a cladding and endplug is to be sound to prevent a leakage of fission products from a cladding as a UO{sub 2} pellet is irradiated. Weld flash was made from a deformation due to a welding heat and increasing the pressure of the resistivity and resistance from a cladding and endplug. Weld line of a welding interface, microstructure of a weldment and a crystallographic structure change were sources of an iodine induced SCC in a reactor. The soundness of a weldment is important because a weld line connects the leakage of fission products from an operational reactor. In this study, welding specimens were fabricated by a resistance welding method using a bundle fuel welder to measure and analyze the torque of an endplug-endplate welding. The torque of a weldment between an endplug and endplate was measured and analyzed with the welding time. The weldability of a weldment between an endplug and endplate was investigated by a metallographic examination.

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain.

Science.gov (United States)

Arnbak, Bodil; Jensen, Tue S; Egund, Niels; Zejden, Anna; Hørslev-Petersen, Kim; Manniche, Claus; Jurik, Anne G

2016-04-01

To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. • The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.

Numerical Study of Electrostatic Field Distortion on LPTPC End-Plates based on Bulk Micromegas Modules

Directory of Open Access Journals (Sweden)

Bhattacharya Purba

2018-01-01

Full Text Available The R&D activities for the linear collider TPC (LC-TPC are currently working on the adoption of the micro pattern devices for the gaseous amplification stage. Several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. We worked on a large prototype TPC with an end-plate that was built, for the first time, using seven resistive bulk Micromegas modules. During experiments, reduced signal sensitivity was observed at the boundary of these modules. Electrostatic field distortion near the module boundaries was considered to be the possible major reason behind these observations. In the present work, we will explore this hypothesis through numerical simulation. Our aim has been to understand the origin of distortions observed close to the edges of the test beam modules and to explore the possibility of using the Garfield simulation framework for investigating a phenomenon as complex as distortion.

A comprehensive model for in-plane and out-of-plane vibration of CANDU fuel endplate rings

Energy Technology Data Exchange (ETDEWEB)

Yu, S.D., E-mail: syu@ryerson.ca; Fadaee, M.

2016-08-01

Highlights: • Proposed an effective method for modelling bending and torsional vibration of CANDU fuel endplate rings. • Applied successfully the thick plate theory to curved structural members by accounting for the transverse shear effect. • The proposed method is computationally more efficient compared to the 3D finite element. - Abstract: In this paper, a comprehensive vibration model is developed for analysing in-plane and out-of-plane vibration of CANDU fuel endplate rings by taking into consideration the effects of in-plane extension in the circumferential and radial directions, shear, and rotatory inertia. The model is based on Reddy’s thick plate theory and the nine-node isoparametric Lagrangian plate finite elements. Natural frequencies of various modes of vibration of circular rings obtained using the proposed method are compared with 3D finite element results, experimental data and results available in the literature. Excellent agreement was achieved.

MR imaging of lumbar spondylolysis: signal intensity change in the pars interarticularis and adjacent structures

Energy Technology Data Exchange (ETDEWEB)

Jang, Suk Whan; Lee, Ghi Jai; Shim, Jae Chan; Kim, Ho Kyun [Inje Univ. College of Medicine, Kimhae (Korea, Republic of)

2001-05-01

To assess changes in MR signal intensity in the pars interarticularis and adjacent structures in patients with lumbar spondylolysis. The MR images of 36 patients with lumbar spondylolysis, confirmed by plain radiographs, were retrospectively analyzed. Using a 1.0T unit, we evaluated the signal intensity of a total of 216 parts interarticulares and adjacent structures from L3 to L5, as seen on sagittal images, and differences between areas with and without spondylolysis. The signal intensity of T1-and T2-weighted images was graded 0(more hypointense than spinal body), 1(as isointense as spinal body), 2(more hyperintense than spinal body and more hypointense than epidural fat), or 3(as isointense as epidural fat). Signal intensity change in endplates and degree of spondylolisthesis were analyzed, and the relationship between these factors was determined. Spondylolysis was noted at L5 in 61 cases, at L4 in 22, and of L3 in no case. In three cases spondylolysis was unilateral, and in the remainder it was bilateral. The degree of signal intensity was the same on T1-and T2-weighted images, and no case was grade 0. Eighty-six of 133 areas without spondylolysis were grade 1, 43 were grade 2, and four were grade 3. In 42 of 47 cases, signal intensity change was localized at pedicles. Among 83 areas with spondylolysis,on the other hand, nine were grade 1, 48 were grade 2, and 26 were grade 3. Signal intensity change was most commonly observed at the pars interarticularis, pedicle, and lamina(50/74)({rho}<0.001). Signal intensity change at the pars interarticularis and adjacent structures was accompanied in most cases by degenerative endplate change(10/11) and spondylolisthesis(11/13)({rho}<0.001). In patients with spondylolysis, signal intensity was frequently higher at the pars interarticularis and adjacent structures, and is thought to have a close relationship with degenerative endplate change and spondylolisthesis. Increases in signal intensity at the pars

MR imaging of lumbar spondylolysis: signal intensity change in the pars interarticularis and adjacent structures

International Nuclear Information System (INIS)

Jang, Suk Whan; Lee, Ghi Jai; Shim, Jae Chan; Kim, Ho Kyun

2001-01-01

To assess changes in MR signal intensity in the pars interarticularis and adjacent structures in patients with lumbar spondylolysis. The MR images of 36 patients with lumbar spondylolysis, confirmed by plain radiographs, were retrospectively analyzed. Using a 1.0T unit, we evaluated the signal intensity of a total of 216 parts interarticulares and adjacent structures from L3 to L5, as seen on sagittal images, and differences between areas with and without spondylolysis. The signal intensity of T1-and T2-weighted images was graded 0(more hypointense than spinal body), 1(as isointense as spinal body), 2(more hyperintense than spinal body and more hypointense than epidural fat), or 3(as isointense as epidural fat). Signal intensity change in endplates and degree of spondylolisthesis were analyzed, and the relationship between these factors was determined. Spondylolysis was noted at L5 in 61 cases, at L4 in 22, and of L3 in no case. In three cases spondylolysis was unilateral, and in the remainder it was bilateral. The degree of signal intensity was the same on T1-and T2-weighted images, and no case was grade 0. Eighty-six of 133 areas without spondylolysis were grade 1, 43 were grade 2, and four were grade 3. In 42 of 47 cases, signal intensity change was localized at pedicles. Among 83 areas with spondylolysis,on the other hand, nine were grade 1, 48 were grade 2, and 26 were grade 3. Signal intensity change was most commonly observed at the pars interarticularis, pedicle, and lamina(50/74)(ρ<0.001). Signal intensity change at the pars interarticularis and adjacent structures was accompanied in most cases by degenerative endplate change(10/11) and spondylolisthesis(11/13)(ρ<0.001). In patients with spondylolysis, signal intensity was frequently higher at the pars interarticularis and adjacent structures, and is thought to have a close relationship with degenerative endplate change and spondylolisthesis. Increases in signal intensity at the pars interarticularis and

Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

International Nuclear Information System (INIS)

Ding, L.; Wu, J.P.; Xu, G.; Zhu, B.; Zeng, Q.M.; Li, D.F.; Lu, W.

2014-01-01

Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis

Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

Energy Technology Data Exchange (ETDEWEB)

Ding, L.; Wu, J.P. [Fudan University, Jinshan Hospital, Department of Orthopaedics, Shanghai, China, Department of Orthopaedics, Jinshan Hospital, Fudan University, Shanghai (China); Xu, G. [Fudan University, Jinshan Hospital, Center Laboratory, Shanghai, China, Center Laboratory, Jinshan Hospital, Fudan University, Shanghai (China); Zhu, B.; Zeng, Q.M.; Li, D.F.; Lu, W. [Fudan University, Jinshan Hospital, Department of Orthopaedics, Shanghai, China, Department of Orthopaedics, Jinshan Hospital, Fudan University, Shanghai (China)

2014-05-09

Current studies find that degenerated cartilage endplates (CEP) of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA) was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

Lentiviral-mediated RNAi targeting caspase-3 inhibits apoptosis induced by serum deprivation in rat endplate chondrocytes in vitro

Directory of Open Access Journals (Sweden)

L. Ding

2014-06-01

Full Text Available Current studies find that degenerated cartilage endplates (CEP of vertebrae, with fewer diffusion areas, decrease nutrient supply and accelerate intervertebral disc degeneration. Many more apoptotic cells have been identified in degenerated than in normal endplates, and may be responsible for the degenerated grade. Previous findings suggest that inhibition of apoptosis is one possible approach to improve disc regeneration. It is postulated that inhibition of CEP cell apoptosis may be responsible for the regeneration of endplates. Caspase-3, involved in the execution phase of apoptosis, is a candidate for regulating the apoptotic process. In the present study, CEP cells were incubated in 1% fetal bovine serum. Activated caspases were detected to identify the apoptotic pathway, and apoptosis was quantified by flow cytometry. Lentiviral caspase-3 short hairpin RNA (shRNA was employed to study its protective effects against serum deprivation. Silencing of caspase-3 expression was quantified by reverse transcription-polymerase chain reaction and Western blots, and inhibition of apoptosis was quantified by flow cytometry. Serum deprivation increased apoptosis of rat CEP cells through activation of a caspase cascade. Lentiviral caspase-3 shRNA was successfully transduced into CEP cells, and specifically silenced endogenous caspase-3 expression. Surviving cells were protected by the downregulation of caspase-3 expression and activation. Thus, lentiviral caspase-3 shRNA-mediated RNAi successfully silenced endogenous caspase-3 expression, preventing inappropriate or premature apoptosis.

Numerical Study on the Structural Performance of Steel Beams with Slant End-plate Connections

Directory of Open Access Journals (Sweden)

Farshad Zahmatkesh

Full Text Available Abstract Thermal effects can be one of the most harmful conditions that any steel structure should expect throughout its service life. To counteract this effect, a new beam, with a capability to dissipate thermally induced axial force by slanting of end-plate connection at both ends, is proposed. The beam was examined in terms of its elastic mechanical behavior under symmetric transverse load in presence of an elevated temperature by means of direct stiffness finite element model. The performance of such connection is defined under two resisting mechanisms; by friction force dissipation between faces of slant connection and by small upward crawling on slant plane. The presented numerical method is relatively easy and useful to evaluate the behavior of the proposed beam of various dimensions at different temperatures. Its applicability is evident through satisfactory results verification with those from experimental, analytical and commercially available finite element software. Based on the good agreement between theoretical and experimental methods, a series of design curves were developed as a safe-practical range for the slant end-plate connections which are depend on the conditions of the connection.

State-of-the-art management of low back pain in athletes: Instructional lecture.

Science.gov (United States)

Sairyo, Koichi; Nagamachi, Akihiro

2016-05-01

In this paper, we describe "state of the art" on the diagnosis and treatment for low back pain in athletes. Lumbar motion that induces specific pain would be a clue to the exact diagnosis. In the flexion pain group, lumbar herniated nucleus pulposus is the most common disorder. Discogenic pain and type 1 Modic endplate inflammation may also cause flexion pain; however, the diagnosis is sometimes difficult. In children and adolescents, apophyseal ring fracture is prevalent. In the extension pain group, lumbar spondylolysis is very common, especially in pediatric athletes. In adults, facet pain due to overloading would be the pathology, while low back pain with trunk rotation is not common. However, throwing athletes, such as pitchers and hammer throwers, may experience this kind of pain; facet arthritis contralateral to the throwing arm would be the origin of the pain. Low back pain on lumbar lateral bending is rare, but we experienced some cases in golfers in whom type 1 Modic change at the lateral corner was the source of pain. In this article, we explained strategies for state-of-the-art diagnosis and minimally invasive treatment. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Does nuclear tissue infected with bacteria following disc herniations lead to Modic changes in the adjacent vertebrae?

DEFF Research Database (Denmark)

Albert, H. B.; Lambert, Peter; Rollason, Jess

2013-01-01

PURPOSE: To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema...... due to cytokine and propionic acid production. METHODS: Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent...... antiseptic sterile protocols were followed. RESULTS: Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were...

Electrical stimulation of paralyzed vibrissal muscles reduces endplate reinnervation and does not promote motor recovery after facial nerve repair in rats.

Science.gov (United States)

Sinis, Nektarios; Horn, Frauke; Genchev, Borislav; Skouras, Emmanouil; Merkel, Daniel; Angelova, Srebrina K; Kaidoglou, Katerina; Michael, Joern; Pavlov, Stoyan; Igelmund, Peter; Schaller, Hans-Eberhard; Irintchev, Andrey; Dunlop, Sarah A; Angelov, Doychin N

2009-10-01

The outcome of peripheral nerve injuries requiring surgical repair is poor. Recent work has suggested that electrical stimulation (ES) of denervated muscles could be beneficial. Here we tested whether ES has a positive influence on functional recovery after injury and surgical repair of the facial nerve. Outcomes at 2 months were compared to animals receiving sham stimulation (SS). Starting on the first day after end-to-end suture (facial-facial anastomosis), electrical stimulation (square 0.1 ms pulses at 5 Hz at an ex tempore established threshold amplitude of between 3.0 and 5.0V) was delivered to the vibrissal muscles for 5 min a day, 3 times a week. Restoration of vibrissal motor performance following ES or SS was evaluated using the video-based motion analysis and correlated with the degree of collateral axonal branching at the lesion site, the number of motor endplates in the target musculature and the quality of their reinnervation, i.e. the degree of mono- versus poly-innervation. Neither protocol reduced collateral branching. ES did not improve functional outcome, but rather reduced the number of innervated motor endplates to approximately one-fifth of normal values and failed to reduce the proportion of poly-innervated motor endplates. We conclude that ES is not beneficial for recovery of whisker function after facial nerve repair in rats.

Effect of Zoledronic Acid and Denosumab in Patients With Low Back Pain and Modic Change: A Proof-of-Principle Trial.

Science.gov (United States)

Cai, Guoqi; Laslett, Laura L; Aitken, Dawn; Halliday, Andrew; Pan, Feng; Otahal, Petr; Speden, Deborah; Winzenberg, Tania M; Jones, Graeme

2018-05-01

The aim of this study was to evaluate the effect of zoledronic acid (ZA) and denosumab on low back pain (LBP) and Modic change (MC) over 6 months. Adults aged ≥40 years with significant LBP for at least 6 months duration and MC (type 1, 2, or mixed) were randomized to receive ZA (5 mg/100 mL), denosumab (60 mg), or placebo. LBP was measured monthly by visual analogue scale (VAS) and the LBP Rating Scale (RS). MC was measured from MRIs of T 12 -S 1 vertebrae at screening and 6 months. A total of 103 participants with moderate/severe LBP (mean VAS = 57 mm; mean RS = 18) and median total MC area 538 mm 2 were enrolled. Compared to placebo, LBP reduced significantly at 6 months in the ZA group for RS (-3.3; 95% CI, -5.9 to -0.7) but not VAS (-8.2; 95% CI, -18.8 to +2.4) with similar findings for denosumab (RS, -3.0; 95% CI, -5.7 to -0.3; VAS, -10.7; 95% CI, -21.7 to +0.2). There was little change in areal MC size overall and no difference between groups with the exception of denosumab in those with type 1 Modic change (-22.1 mm 2 ; 95% CI, -41.5 to -2.7). In post hoc analyses, both medications significantly reduced VAS LBP in participants with milder disc degeneration and non-neuropathic pain, and denosumab reduced VAS LBP in those with type 1 MC over 6 months, compared to placebo. Adverse events were more frequent in the ZA group. These results suggests a potential therapeutic role for ZA and denosumab in MC-associated LBP. © 2018 American Society for Bone and Mineral Research. © 2018 American Society for Bone and Mineral Research.

MRI reporting by radiographers: The construction of an objective structured examination

International Nuclear Information System (INIS)

Piper, K.J.; Buscall, K.L.

2008-01-01

Purpose: The aim was to construct a bank of general magnetic resonance imaging (MRI) investigations where good agreement was demonstrated between three independent radiological reports. The bank was subsequently to be used to assess radiographers' ability to accurately report at the end of an accredited programme; Postgraduate Certificate (PgC) Clinical Reporting (MRI-General Investigations). Method: Eighty-seven examinations (33 knee, 36 lumbar spine and 18 internal auditory meatus-IAM) were initially reported by two radiologists. Seventy-two of these examinations (25 knee, 29 lumbar spine and 18 IAM) were subsequently reported by a third radiologist. Interobserver agreement was assessed by estimating the total, positive and negative % agreement rates; and by use of the weighted or unweighted kappa values. Knee reports were analysed for meniscal tears, and degenerative meniscus (264 meniscal sites); ligament injury (ACL; PCL; MCI; and LCL; 132 ligament sites); bone bruise; effusion; fracture and/or osteochondral defect. Lumbar spine reports were analysed for disc morphology (bulge, protrusion, extrusion and/or annular tear-180 intervertebral disc levels); degenerative disc disease; Modic endplate changes; cord compression; spinal stenosis; nerve root involvement; vertebral collapse, primary tumour or metastases; and other incidental findings. IAM reports were analysed for acoustic neuroma and vascular loop. Results: Agreement in the knee reports varied mainly between moderate (κ = 0.46) for ligament injury to very good [almost perfect] (κ = 0.86) for meniscal tears, although agreement for degenerative meniscus was only fair (κ = 0.3). Variation in the lumbar spine reports ranged predominantly between moderate (κ = 0.54) for disc bulge/protrusion to fair (κ = 0.32) for Modic endplate changes to good [substantial] (κ = 0.79) for tumour/metastases. Agreement for the presence of acoustic neuroma was very good [almost perfect] (κ = 1.0). Forty cases

Clinical and radiological results 6 years after treatment of traumatic thoracolumbar burst fractures with pedicle screw instrumentation and balloon assisted endplate reduction

NARCIS (Netherlands)

Verlaan, Jorrit Jan; Somers, Inne; Dhert, Wouter J A; Oner, F. Cumhur

2015-01-01

Background context  When used to fixate traumatic thoracolumbar burst fractures, pedicle screw constructs may fail in the presence of severe vertebral body comminution as the intervertebral disc can creep through the fractured endplates leading to insufficient anterior column support.

The role of desensititation in decay time of miniature endplate currents in frogs Rana ridibunda and Rana temporaria

Czech Academy of Sciences Publication Activity Database

Giniatullin, R. A.; Talantova, M. V.; Vyskočil, František

2001-01-01

Roč. 39, č. 3 (2001), s. 287-292 ISSN 0168-0102 R&D Projects: GA AV ČR IAA7011902; GA MŠk VS97099; GA MŠk OK 267 Grant - others:RFBR(RU) 98-04-48044; INTAS(BE) 2000-1147 Institutional research plan: CEZ:AV0Z5011922 Keywords : frog * desensitisation * miniature endplate potential Subject RIV: ED - Physiology Impact factor: 1.770, year: 2001

An analysis of the effect of endplates upon the fin keel of a sailing yacht

International Nuclear Information System (INIS)

Andrews, G.T.; Raiskums, C.L.; Keffer, J.F.

1985-01-01

A long-term investigation is presently underway to assess the overall performance of the modern design of fin keels for sailing yachts. An ultimate goal is to determine the specific advantages for such designs with respect to a centre-board configuration with outside ballast. The present preliminary studies were carried out to determine the basic performance of a typical fin keel shape for various values of leeway angle. A second aspect was to determine the effect upon this baseline performance of a number of endplates of varying sizes and shapes. (author)

The mechanisms of inhibition of frog endplate currents with homologous derivatives of the 1,1-dimethyl-3-oxybutyl phosphonic acid

Czech Academy of Sciences Publication Activity Database

Pryazhnikov, E.; Ostroumov, A.; Druginina, O.; Vyskočil, František; Skorinkin, A.

2012-01-01

Roč. 61, č. 4 (2012), s. 395-404 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA202/09/0806; GA AV ČR(CZ) IAA500110905 Institutional research plan: CEZ:AV0Z50110509 Keywords : endplate potential * nicotinic cholinoreceptor * allosteric modulation * open channel block * lipophilicity and cholinergic effect Subject RIV: ED - Physiology Impact factor: 1.531, year: 2012

Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect

International Nuclear Information System (INIS)

Jaffey, A.H.; Gray, J.; Bentley, W.C.; Lerner, J.L.

1987-09-01

A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has 85 Kr (beta energy, 0.67 MeV). The wall effect calculation is readily extendable to other beta energies

MRI of transforaminal lumbar interbody fusion: imaging appearance with and without the use of human recombinant bone morphogenetic protein-2 (rhBMP-2)

Energy Technology Data Exchange (ETDEWEB)

Fox, Michael G.; Goldberg, Judd M.; Gaskin, Cree M.; Barr, Michelle S.; Alford, Bennett [University of Virginia, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Patrie, James T. [University of Virginia, Department of Public Health Sciences, Charlottesville, VA (United States); Shen, Francis H. [University of Virginia, Department of Orthopedic Surgery, Charlottesville, VA (United States)

2014-09-15

To describe the vertebral endplate and intervertebral disc space MRI appearance following TLIF, with and without the use of rhBMP-2, and to determine if the appearance is concerning for discitis/osteomyelitis. After institutional review board approval, 116 TLIF assessments performed on 75 patients with rhBMP-2 were retrospectively and independently reviewed by five radiologists and compared to 73 TLIF assessments performed on 45 patients without rhBMP-2. MRIs were evaluated for endplate signal, disc space enhancement, disc space fluid, and abnormal paraspinal soft tissue. Endplate edema-like signal was reported when T1-weighted hypointensity, T2-weighted hyperintensity, and endplate enhancement were present. Subjective concern for discitis/osteomyelitis on MRI was graded on a five-point scale. Generalized estimating equation binomial regression model analysis was performed with findings correlated with rhBMP-2 use, TLIF level, graft type, and days between TLIF and MRI. The rhBMP-2 group demonstrated endplate edema-like signal (OR 5.66; 95 % CI [1.58, 20.24], p = 0.008) and disc space enhancement (OR 2.40; 95 % CI [1.20, 4.80], p = 0.013) more often after adjusting for the TLIF level, graft type, and the number of days following TLIF. Both groups had a similar temporal distribution for endplate edema-like signal but disc space enhancement peaked earlier in the rhBMP-2 group. Disc space fluid was only present in the rhBMP-2 group. Neither group demonstrated abnormal paraspinal soft tissue and discitis/osteomyelitis was not considered likely in any patient. Endplate edema-like signal and disc space enhancement were significantly more frequent and disc space enhancement developed more rapidly following TLIF when rhBMP-2 was utilized. The concern for discitis/osteomyelitis was similar and minimal in both groups. (orig.)

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain

Energy Technology Data Exchange (ETDEWEB)

Arnbak, Bodil; Jensen, Tue S.; Manniche, Claus [Hospital Lillebaelt, Research Department, Spine Centre of Southern Denmark, Middelfart (Denmark); University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); Egund, Niels; Zejden, Anna [Aarhus University Hospital, Department of Radiology, Aarhus C (Denmark); Hoerslev-Petersen, Kim [University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); King Christian 10th Hospital for Rheumatic Diseases, Graasten, Graasten (Denmark); Jurik, Anne G. [Hospital Lillebaelt, Research Department, Spine Centre of Southern Denmark, Middelfart (Denmark); University of Southern Denmark, Institute of Regional Health Research, Odense C (Denmark); Aarhus University Hospital, Department of Radiology, Aarhus C (Denmark)

2016-04-15

To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. (orig.)

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain

International Nuclear Information System (INIS)

Arnbak, Bodil; Jensen, Tue S.; Manniche, Claus; Egund, Niels; Zejden, Anna; Hoerslev-Petersen, Kim; Jurik, Anne G.

2016-01-01

To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. (orig.)

Intercellular signaling pathways active during intervertebral disc growth, differentiation, and aging.

Science.gov (United States)

Dahia, Chitra Lekha; Mahoney, Eric J; Durrani, Atiq A; Wylie, Christopher

2009-03-01

Intervertebral discs at different postnatal ages were assessed for active intercellular signaling pathways. To generate a spatial and temporal map of the signaling pathways active in the postnatal intervertebral disc (IVD). The postnatal IVD is a complex structure, consisting of 3 histologically distinct components, the nucleus pulposus, fibrous anulus fibrosus, and endplate. These differentiate and grow during the first 9 weeks of age in the mouse. Identification of the major signaling pathways active during and after the growth and differentiation period will allow functional analysis using mouse genetics and identify targets for therapy for individual components of the disc. Antibodies specific for individual cell signaling pathways were used on cryostat sections of IVD at different postnatal ages to identify which components of the IVD were responding to major classes of intercellular signal, including sonic hedgehog, Wnt, TGFbeta, FGF, and BMPs. We present a spatial/temporal map of these signaling pathways during growth, differentiation, and aging of the disc. During growth and differentiation of the disc, its different components respond at different times to different intercellular signaling ligands. Most of these are dramatically downregulated at the end of disc growth.

Use of a Y-tube conduit after facial nerve injury reduces collateral axonal branching at the lesion site but neither reduces polyinnervation of motor endplates nor improves functional recovery.

Science.gov (United States)

Hizay, Arzu; Ozsoy, Umut; Demirel, Bahadir Murat; Ozsoy, Ozlem; Angelova, Srebrina K; Ankerne, Janina; Sarikcioglu, Sureyya Bilmen; Dunlop, Sarah A; Angelov, Doychin N; Sarikcioglu, Levent

2012-06-01

Despite increased understanding of peripheral nerve regeneration, functional recovery after surgical repair remains disappointing. A major contributing factor is the extensive collateral branching at the lesion site, which leads to inaccurate axonal navigation and aberrant reinnervation of targets. To determine whether the Y tube reconstruction improved axonal regrowth and whether this was associated with improved function. We used a Y-tube conduit with the aim of improving navigation of regenerating axons after facial nerve transection in rats. Retrograde labeling from the zygomatic and buccal branches showed a halving in the number of double-labeled facial motor neurons (15% vs 8%; P facial-facial anastomosis coaptation. However, in both surgical groups, the proportion of polyinnervated motor endplates was similar (≈ 30%; P > .05), and video-based motion analysis of whisking revealed similarly poor function. Although Y-tube reconstruction decreases axonal branching at the lesion site and improves axonal navigation compared with facial-facial anastomosis coaptation, it fails to promote monoinnervation of motor endplates and confers no functional benefit.

Numerical Simulations on the Laser Spot Welding of Zirconium Alloy Endplate for Nuclear Fuel Bundle Assembly

Science.gov (United States)

Satyanarayana, G.; Narayana, K. L.; Boggarapu, Nageswara Rao

2018-03-01

In the nuclear industry, a critical welding process is joining of an end plate to a fuel rod to form a fuel bundle. Literature on zirconium welding in such a critical operation is limited. A CFD model is developed and performed for the three-dimensional non-linear thermo-fluid analysis incorporating buoyancy and Marnangoni stress and specifying temperature dependent properties to predict weld geometry and temperature field in and around the melt pool of laser spot during welding of a zirconium alloy E110 endplate with a fuel rod. Using this method, it is possible to estimate the weld pool dimensions for the specified laser power and laser-on-time. The temperature profiles will estimate the HAZ and microstructure. The adequacy of generic nature of the model is validated with existing experimental data.

Thermal Behaviour of Beams with Slant End-Plate Connection Subjected to Nonsymmetric Gravity Load

Directory of Open Access Journals (Sweden)

Farshad Zahmatkesh

2014-01-01

Full Text Available Research on the steel structures with confining of axial expansion in fixed beams has been quite intensive in the past decade. It is well established that the thermal behaviour has a key influence on steel structural behaviours. This paper describes mechanical behaviour of beams with bolted slant end-plate connection with nonsymmetric gravity load, subjected to temperature increase. Furthermore, the performance of slant connections of beams in steel moment frame structures in the elastic field is investigated. The proposed model proved that this flexible connection system could successfully decrease the extra thermal induced axial force by both of the friction force dissipation among two faces of slant connection and a small upward movement on the slant plane. The applicability of primary assumption is illustrated. The results from the proposed model are examined within various slant angles, thermal and friction factors. It can be concluded that higher thermal conditions are tolerable when slanting connection is used.

Discogentic lumbar pain: association with MRI and discography

International Nuclear Information System (INIS)

Chen Jianyu; Liu Qingyu; Liang Biling; Ye Ruixin; Zhong Jinglian

2008-01-01

Objective: To evaluate the correlation between MRI and X-Ray discography findings and pain response at provocative discography in patients with discogenic back pain. Methods: Two hundred and fifty-six lumbar intervertebral discs in 93 patients who underwent MRI and X-Ray discography were included in this study. MR images were retrospectively evaluated regarding disc degeneration, endplate abnormalities and high intensity zone. Disc degeneration was graded according to the modified criteria of Pearce, et al. Evaluation of disc morphology was performed with X-Ray discography by using the classification of Adams, et al. Endplates and adjacent bone marrow abnormalities were classified according to Modic,et al. During discography concordant pain was regarded as positive, whereas discordant pain and no pain were regarded as negative. The data were analyzed using the Chi-square test. Results: There were 116 discs with concordant pain and 140 discs with discordant pain or no pain. of 256 discs on discography , 17 discs were type I 17 (6.6%), type II were 25 (9.8%), type III were 91 (35.5%), type IV were 77(30.1%) and type V were 46(18.0%). On MR images, discs of grade I were 23 (9.0%), grade II were 34 (13.3%), grade III were 84 (32.8%), grade IV were 85 (33.2%) and grade V were 30(11.7% ). There was positive correlation between Pearce graded of MRI and classification of Adams of discography (r=0.62, χ 2 =160.87, P 2 =144.08, P 2 =137.11, P 2 = 51.93, P 2 =52.76, P<0.01). Conclusion: In patients with chronic low back pain, MR imaging may present moderate to severe disc degeneration, high intensity zone, endplates and adjacent bone marrow abnormalities. MR findings with concordant pain can raise the diagnostic possibility of discogenic lumbar pain. Typical discography findings, fissured or ruptured disc, with concordant pain are important diagnostic evidence for discogenic lumbar pain. (authors)

The comparative study of radiograph, MRI and pathology in degeneration of lumbar intervertebral disc

International Nuclear Information System (INIS)

Shang Tiesong; Wang Yunzhao

2002-01-01

Objective: To investigate the pathology, and MRI features of the degeneration of lumbar intervertebral discs (IVD). Methods: Thirteen human lumbar spine segments with 31 IVDs were harvested from fresh cadavers. High quality radiographs were taken for all specimens. Five segments with 20 IVD underwent MRl. Then, the radiographic and MRI findings were correlated with corresponding 87 pathologic sections. Results: Variant degeneration was observed in pathologic sections in all 31 IVDs. With MRI T 2 WI images, 20 IVDs showed linear and spotty high signal in the annular fibers, or most of the IVD showed high signal. On pathologic cuts, 22 of 31 IVDs showed infolding of annular fibers, 18 of 31 showed outfolding of annular fibers. On MRI T 1 WI and T 2 WI images, infolding and outfolding of annular fibers were seen as low signal. 20 of 31 IVDs had necrotic debris of cells in the nucleus pulposus. 14 of 20 demonstrated spotty low signal areas on MRI T 2 WI images. 7 Schmorl nodules were found. On pathologic sections Schmorl nodules were seen as IVD tissue protruding into vertebral endplates, they were seen as high signal on T 2 WI images. Two large fissures found on sections were seen as low signal on T 2 WI. Degenerative fibrosis seen on 6 IVD, which showed intermediate signal on T 2 WI images. However, radiographs only demonstrated osteophytes on 3 vertebrae, 7 Schmorl's nodules. Sclerotic, concave and irregular endplates were seen in 11 IVDs, the tatter is the indication of cartilaginous endplate disruption, Conclusion: MRI is very useful in demonstrating the degeneration of IVD, radiograph is able to indirectly show the disappearance of cartilaginous endplate

Ultrashort time-to-echo MRI of the cartilaginous endplate: technique and association with intervertebral disc degeneration

International Nuclear Information System (INIS)

Law, Travis; Anthony, Marina-Portia; Kim, Mina; Khong, Pek-Lan; Chan, Queenie; Samartzis, Dino

2013-01-01

The purpose of this study was to report the feasibility of the ultrashort time-to-echo (UTE) MRI technique to assess cartilaginous endplate (CEP) defects in humans in vivo and to assess their relationship with intervertebral disc (IVD) degeneration. Nine volunteer subjects (mean age=43.9 years; range=22–61 years) were recruited, representing 54 IVDs and 108 CEPs. The subjects underwent T2-weighted and UTE MRI to assess for the presence and severity of IVD degeneration, and for the presence of CEP defects, respectively, from T12 to S1. IVD degeneration was graded according to the Schneiderman et al. classification on T2-weighted MRI. CEP defects were defined on UTE MRI as discontinuity of high signal over four consecutive images and were independently assessed by two observers. Thirty-seven out of 108 (34.3%) CEPs had defects, which mainly occurred at T12/L1, L1/L2 and L4/L5 (P=0.008). Multivariate logistic regression revealed that lower body mass index (P=0.009) and younger (P=0.034) individuals had a decreased likelihood of having CEP defects. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration (P=0.036). A higher prevalence of degenerated IVDs with CEP defects was found at L4/5 and L5/S1, while degenerated IVDs with no CEP defects were found throughout the whole lumbar region. Mean IVD degeneration scores of the L4/5 and L5/S1 levels with CEP defects were higher in comparison with those with no CEP defects. Our study demonstrates the feasibility of using UTE MRI in humans in vivo to assess the integrity of the CEP. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration. In the lower lumbar region, more severe degeneration was found to occur in the IVDs with CEP defects than in those without defects.

Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

International Nuclear Information System (INIS)

Morrison, J.L.; Kaplan, P.A.; Dussault, R.G.; Anderson, M.W.

2000-01-01

Objective. Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.Design. Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.Conclusions. Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment. (orig.)

Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

Energy Technology Data Exchange (ETDEWEB)

Morrison, J.L.; Kaplan, P.A.; Dussault, R.G.; Anderson, M.W. [Dept. of Radiology, Univ. of Virginia Health System, Charlottesville, VA (United States)

2000-12-01

Objective. Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.Design. Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.Conclusions. Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment. (orig.)

The 'Lumbar Fusion Outcome Score' (LUFOS): a new practical and surgically oriented grading system for preoperative prediction of surgical outcomes after lumbar spinal fusion in patients with degenerative disc disease and refractory chronic axial low back pain.

Science.gov (United States)

Mattei, Tobias A; Rehman, Azeem A; Teles, Alisson R; Aldag, Jean C; Dinh, Dzung H; McCall, Todd D

2017-01-01

In order to evaluate the predictive effect of non-invasive preoperative imaging methods on surgical outcomes of lumbar fusion for patients with degenerative disc disease (DDD) and refractory chronic axial low back pain (LBP), the authors conducted a retrospective review of 45 patients with DDD and refractory LBP submitted to anterior lumbar interbody fusion (ALIF) at a single center from 2007 to 2010. Surgical outcomes - as measured by Visual Analog Scale (VAS/back pain) and Oswestry Disability Index (ODI) - were evaluated pre-operatively and at 6 weeks, 3 months, 6 months, and 1 year post-operatively. Linear mixed-effects models were generated in order to identify possible preoperative imaging characteristics (including bone scan/99mTc scintigraphy increased endplate uptake, Modic endplate changes, and disc degeneration graded according to Pfirrmann classification) which may be predictive of long-term surgical outcomes . After controlling for confounders, a combined score, the Lumbar Fusion Outcome Score (LUFOS), was developed. The LUFOS grading system was able to stratify patients in two general groups (Non-surgical: LUFOS 0 and 1; Surgical: LUFOS 2 and 3) that presented significantly different surgical outcomes in terms of estimated marginal means of VAS/back pain (p = 0.001) and ODI (p = 0.006) beginning at 3 months and continuing up to 1 year of follow-up. In conclusion,  LUFOS has been devised as a new practical and surgically oriented grading system based on simple key parameters from non-invasive preoperative imaging exams (magnetic resonance imaging/MRI and bone scan/99mTc scintigraphy) which has been shown to be highly predictive of surgical outcomes of patients undergoing lumbar fusion for treatment for refractory chronic axial LBP.

Is the presence of Modic changes associated with the outcomes of different treatments? A systematic critical review

Directory of Open Access Journals (Sweden)

Jensen Rikke K

2011-08-01

Full Text Available Abstract Background Modic changes (MCs have been identified as a diagnostic subgroup associated with low back pain (LBP. The aetiology of MCs is still unknown and there is no effective treatment available. If MCs constitute a specific subgroup of LBP, it seems reasonable to expect different effects from different treatments. The objective of this systematic critical literature review was therefore to investigate if there is evidence in the literature that the presence of MCs at baseline is associated with a favourable outcome depending on the treatment provided for LBP. Methods The databases MEDLINE and EMBASE were searched for relevant articles from 1984 to December 2010. A checklist including items related to the research questions and quality of the articles was used for data extraction and quality assessment. Of the 1650 articles found, five (six studies were included in this review but because the studies were so heterogeneous, the results have been reported separately for each study. Results The treatments studied were: lumbar epidural steroid injections (n = 1, lumbar intradiscal steroid injections (n = 2, lumbar disc replacement (n = 1, fusion surgery (n = 1 and exercise therapy (n = 1. One of the two studies investigating treatment with intradiscal steroid injections and the study investigating fusion surgery reported that MCs were positively associated with the outcomes of pain and disability. The other study on lumbar intradiscal steroid injections and the study on lumbar epidural steroid injections reported mixed results, whereas the study on lumbar disc replacement and the study on exercise therapy reported that MCs were not associated with the outcomes of pain and disability. Conclusions The available studies on the topic were too few and too heterogeneous to reach a definitive conclusion and it is therefore still unclear if MCs may be of clinical importance when guiding or prescribing the 'right' treatment for a patient with LBP.

MR imaging features of hemispherical spondylosclerosis

Energy Technology Data Exchange (ETDEWEB)

Vicentini, Joao R.T.; Martinez-Salazar, Edgar L.; Chang, Connie Y.; Bredella, Miriam A.; Rosenthal, Daniel I.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

2017-10-15

Hemispherical spondylosclerosis (HS) is a rare degenerative entity characterized by dome-shaped sclerosis of a single vertebral body that may pose a diagnostic dilemma. The goal of this study was to describe the MR imaging features of HS. We identified spine radiographs and CT examinations of subjects with HS who also had MR imaging for correlation. Two musculoskeletal radiologists independently assessed sclerosis characteristics, presence of endplate erosions, marrow signal intensity, and disk degeneration (Pfirrmann scale). We identified 11 subjects (six males, five females, mean 48 ± 10 years) with radiographic/CT findings of HS. The most commonly affected vertebral body was L4 (6/11; 55%). On MR imaging, variable signal intensity was noted, being most commonly low on T1 (8/11, 73%) and high on fat-suppressed T2-weighted (8/11, 73%) images. In two subjects, diffuse post-contrast enhancement was seen in the lesion. Moderate disk degeneration and endplate bone erosions adjacent to sclerosis were present in all subjects. Erosions of the opposite endplate were present in two subjects (2/11, 18%). CT data from nine subjects showed the mean attenuation value of HS was 472 ± 96 HU. HS appearance on MR imaging is variable and may not correlate with the degree of sclerosis seen on radiographs or CT. Disk degenerative changes and asymmetric endplate erosions are consistent markers of HS. (orig.)

Predictive factors associated with neck pain in patients with cervical disc degeneration: A cross-sectional study focusing on Modic changes.

Science.gov (United States)

Kong, Lingde; Tian, Weifeng; Cao, Peng; Wang, Haonan; Zhang, Bing; Shen, Yong

2017-10-01

The predictive factors associated with neck pain remain unclear. We conducted a cross-sectional study to assess predictive factors, especially Modic changes (MCs), associated with the intensity and duration of neck pain in patients with cervical disc degenerative disease.We retrospectively reviewed patients in our hospital from January 2013 to December 2016. Severe neck pain (SNP) and persistent neck pain (PNP) were the 2 main outcomes, and were assessed based on the numerical rating scale (NRS). Basic data, and also imaging data, were collected and analyzed as potential predictive factors. Univariate analysis and multiple logistic regression analysis were performed to assess the predictive factors for neck pain.In all, 381 patients (193 males and 188 females) with cervical degenerative disease were included in our study. The number of patients with SNP and PNP were 94 (24.67%) and 109 (28.61%), respectively. The NRS of neck pain in patients with type 1 MCs was significantly higher than type 2 MCs (4.8 ± 0.9 vs 3.9 ± 1.1; P = .004). The multivariate logistic analysis showed that kyphosis curvature (odds ratio [OR] 1.082, 95% confidence interval [CI] 1.044-1.112), spondylolisthesis (OR 1.339, 95% CI 1.226-1.462), and annular tear (OR 1.188, 95% CI 1.021-1.382) were factors associated with SNP, whereas kyphosis curvature (OR 1.568, 95% CI 1.022-2.394), spondylolisthesis (OR 1.486, 95% CI 1.082-2.041), and MCs (OR 1.152, 95% CI 1.074-1.234) were associated with PNP.We concluded that kyphosis curvature, spondylolisthesis, and annular tear are associated with SNP, whereas kyphosis curvature, spondylolisthesis, and MCs are associated with PNP. This study supports the view that MCs can lead to a long duration of neck pain.

Molecular signaling in intervertebral disk development.

Science.gov (United States)

DiPaola, Christian P; Farmer, James C; Manova, Katia; Niswander, Lee A

2005-09-01

The purpose of this investigation is to identify and study the expression pattern of pertinent molecular factors involved in the differentiation of the intervertebral disk (IVD). It is likely that hedgehog genes and the BMP inhibitors are key factors involved in spinal joint formation. Radioactive in situ hybridization with mRNA probes for pax-1, SHH, IHH and Noggin gene was performed on mouse embryo and adult tissue. Immunohistochemistry was performed to localize hedgehog receptor, "patched" (ptc). From 14.5 dpc until birth pax-1 mRNA was expressed in the developing anulus fibrosus (AF). During the same developmental period Noggin mRNA is highly expressed throughout the spine, in the developing AF, while ptc protein and SHH mRNA were expressed in the developing nucleus pulposus (NP). IHH mRNA was expressed by condensing chondrocytes of the vertebral bodies and later becomes confined to the vertebral endplate. We show for the first time that pax-1 is expressed in the adult intervertebral disk. Ptc expression in the NP is an indicator of hedgehog protein signaling in the developing IVD. The expression pattern of the BMP inhibitor Noggin appears to be important for the normal formation of the IVD and may prove to play a role in its segmental pattern formation.

Imaging of degenerative lumbar intervertebral discs; linking anatomy, pathology and imaging.

Science.gov (United States)

Adams, Ashok; Roche, Oran; Mazumder, Asif; Davagnanam, Indran; Mankad, Kshitij

2014-09-01

Low back pain is a common medical condition that has significant implications for healthcare providers and the UK economy. Low back pain can be classified as 'specific' in which an underlying pathophysiological mechanism is identified (eg, herniated intervertebral disc). Advanced imaging should be performed in this situation and in those patients in whom systemic disease is strongly suspected. In the majority (approximately 90%), low back pain in 'non specific' and there is a weak correlation with imaging abnormalities. This is an area of ongoing research and remains controversial in terms of imaging approach and treatment (eg, theory of discogenic pain, interpretation and treatment of endplate changes). With regards Modic endplate changes, current research suggests that an infective component may be involved that may identify novel potential treatments in patients with chronic low back pain refractory to other treatment modalities. MRI is the imaging modality of choice for the assessment of degenerative changes in intervertebral discs. MRI has superior soft tissue contrast resolution when compared to other imaging modalities (eg, plain radiography, CT). An understanding of normal anatomy and MR appearances of intervertebral discs, particularly with regards to how these appearances change with advancing age, is required to aid image interpretation. Knowledge of the spectrum of degenerative processes that may occur in the intervertebral discs is required in order to identify and explain abnormal MRI appearances. As the communication of MRI findings may guide therapeutic decision making and surgical intervention, the terminology used by radiologists must be accurate and consistent. Therefore, description of degenerative disc changes in the current paper is based on the most up-to-date recommendations, the aim being to aid reporting by radiologists and interpretation of reports by referring clinicians. Published by the BMJ Publishing Group Limited. For permission to

Alpha-event and surface characterisation in segmented true-coaxial HPGe detectors

Energy Technology Data Exchange (ETDEWEB)

Abt, I.; Garbini, L., E-mail: luciagarbini86@gmail.com.mpg.de; Gooch, C.; Irlbeck, S.; Liu, X.; Palermo, M.; Schulz, O.

2017-06-21

A detailed study of alpha interactions on the passivation layer on the end-plate of a true-coaxial high-purity germanium detector is presented. The observation of alpha events on such a surface indicates an unexpectedly thin so-called “effective dead layer” of less than 20 µm thickness. In addition, the influence of the metalisation close to the end-plate on the time evolution of the output pulses is discussed. The results indicate that alpha contamination can result in events which could be mistaken as signals for neutrinoless double beta decay and provide some guidance on how to prevent this.

Disc degeneration and chronic low back pain: an association which becomes nonsignificant when endplate changes and disc contour are taken into account

International Nuclear Information System (INIS)

Kovacs, Francisco M.; Arana, Estanislao; Royuela, Ana; Estremera, Ana; Amengual, Guillermo; Sarasibar, Helena; Martinez, Carmen; Asenjo, Beatriz; Galarraga, Isabel; Alonso, Ana; Casillas, Carlos; Muriel, Alfonso; Abraira, Victor

2014-01-01

The objective of this study was to assess the association between severe disc degeneration (DD) and low back pain (LBP). A case-control study was conducted with 304 subjects, aged 35-50, recruited in routine clinical practice across six hospitals; 240 cases (chronic LBP patients with a median pain duration of 46 months) and 64 controls (asymptomatic subjects without any lifetime history of significant LBP). The following variables were assessed once, using previously validated methods: gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, severity of LBP, disability, and findings on magnetic resonance (MRI) (disc degeneration, Modic changes (MC), disc protrusion/hernia, annular tears, spinal stenosis, and spondylolisthesis). Radiologists who interpreted MRI were blinded to the subjects' characteristics. A multivariate logistic regression model assessed the association between severe DD and chronic LBP, adjusting for gender, age, BMI, physical activity, MC, disc protrusion/hernia, and spinal stenosis. Severe DD at ≥1 level was found in 46.9 % of the controls and 65.8 % of the cases. Crude odds ratio (95 % CI), for suffering chronic LBP when having severe DD, was 2.06 (1.05; 4.06). After adjusting for ''MC'' and ''disc protrusion/hernia,'' it was 1.81 (0.81; 4.05). The association between severe DD and LBP ceases to be significant when adjusted for MC and disc protrusion/hernia. These results do not support that DD as a major cause of chronic LBP. (orig.)

Modic changes, possible causes and relation to low back pain

DEFF Research Database (Denmark)

Albert, Hanne Birgit; Kjær, Per; Jensen, Tue Secher

2007-01-01

In patients with low back pain (LBP) it is only possible to diagnose a small proportion, (approximately 20%), on a patho-anatomical basis. Therefore, the identification of relevant LBP subgroups, preferably on a patho-anatomical basis, is strongly needed. Signal changes on MRI in the vertebral body......, and type 3 is sclerotic bone. The temporal evolution of MC is uncertain, but the time span is years. Subchondral bone marrow signal changes associated with pain can be observed in different specific infectious, degenerative and immunological diseases such as osseous infections, osteoarthritis, ankylosing...... cannot thrive in the highly aerobic environment of the MC type 1. Perspectives: One or both of the described mechanisms can - if proven - be of significant importance for this specific subgroup of patients with LBP. Hence, it would be possible to give a more precise and relevant diagnosis to 20...

Disc degeneration and chronic low back pain: an association which becomes nonsignificant when endplate changes and disc contour are taken into account

Energy Technology Data Exchange (ETDEWEB)

Kovacs, Francisco M. [Fundacion Kovacs, Departamento Cientifico, Palma de Mallorca (Spain); Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Arana, Estanislao [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Fundacion Instituto Valenciano de Oncologia, Servicio de Radiologia, Valencia (Spain); Royuela, Ana [CIBER Epidemiologia y Salud Publica (CIBERESP), Madrid (Spain); Hospital Ramon y Cajal, Unidad de Bioestadistica Clinica, IRYCIS, Madrid (Spain); Estremera, Ana; Amengual, Guillermo; Sarasibar, Helena; Martinez, Carmen [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Hospital Son Llatzer, Palma de Mallorca (Spain); Asenjo, Beatriz [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Hospital Carlos Haya, Malaga (Spain); Galarraga, Isabel [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Hospital de Manacor, Manacor, Mallorca (Spain); Alonso, Ana [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Fundacion Jimenez Diaz, Madrid (Spain); Casillas, Carlos [Fundacion Kovacs, Spanish Back Pain Research Network, Palma de Mallorca (Spain); Instituto de Traumatologia Union de Mutuas, Castellon (Spain); Muriel, Alfonso; Abraira, Victor [Hospital Ramon y Cajal, Unidad de Bioestadistica Clinica, IRYCIS, Madrid (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP), Madrid (Spain)

2014-01-15

The objective of this study was to assess the association between severe disc degeneration (DD) and low back pain (LBP). A case-control study was conducted with 304 subjects, aged 35-50, recruited in routine clinical practice across six hospitals; 240 cases (chronic LBP patients with a median pain duration of 46 months) and 64 controls (asymptomatic subjects without any lifetime history of significant LBP). The following variables were assessed once, using previously validated methods: gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, severity of LBP, disability, and findings on magnetic resonance (MRI) (disc degeneration, Modic changes (MC), disc protrusion/hernia, annular tears, spinal stenosis, and spondylolisthesis). Radiologists who interpreted MRI were blinded to the subjects' characteristics. A multivariate logistic regression model assessed the association between severe DD and chronic LBP, adjusting for gender, age, BMI, physical activity, MC, disc protrusion/hernia, and spinal stenosis. Severe DD at ≥1 level was found in 46.9 % of the controls and 65.8 % of the cases. Crude odds ratio (95 % CI), for suffering chronic LBP when having severe DD, was 2.06 (1.05; 4.06). After adjusting for ''MC'' and ''disc protrusion/hernia,'' it was 1.81 (0.81; 4.05). The association between severe DD and LBP ceases to be significant when adjusted for MC and disc protrusion/hernia. These results do not support that DD as a major cause of chronic LBP. (orig.)

Human cartilaginous endplate degeneration is induced by calcium and the extracellular calcium-sensing receptor in the intervertebral disc

Directory of Open Access Journals (Sweden)

MP Grant

2016-07-01

Full Text Available The cartilaginous endplates (CEPs are thin layers of hyaline cartilage found adjacent to intervertebral discs (IVDs. In addition to providing structural support, CEPs regulate nutrient and metabolic exchange in the disc. In IVD pathogenesis, CEP undergoes degeneration and calcification, compromising nutrient availability and disc cell metabolism. The mechanism(s underlying the biochemical changes of CEP in disc degeneration are currently unknown. Since calcification is often observed in later stages of IVD degeneration, we hypothesised that elevations in free calcium (Ca2+ impair CEP homeostasis. Indeed, our results demonstrated that the Ca2+ content was consistently higher in human CEP tissue with grade of disc degeneration. Increasing the levels of Ca2+ resulted in decreases in the secretion and accumulation of collagens type I, II and proteoglycan in cultured human CEP cells. Ca2+ exerted its effects on CEP matrix protein synthesis through activation of the extracellular calcium-sensing receptor (CaSR; however, aggrecan content was also affected independent of CaSR activation as increases in Ca2+ directly enhanced the activity of aggrecanases. Finally, supplementing Ca2+ in our IVD organ cultures was sufficient to induce degeneration and increase the mineralisation of CEP, and decrease the diffusion of glucose into the disc. Thus, any attempt to induce anabolic repair of the disc without addressing Ca2+ may be impaired, as the increased metabolic demand of IVD cells would be compromised by decreases in the permeability of the CEP.

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

Self-reported hard physical work combined with heavy smoking or overweight may result in so-called Modic changes.

Science.gov (United States)

Leboeuf-Yde, Charlotte; Kjaer, Per; Bendix, Tom; Manniche, Claus

2008-01-14

Recently, the MRI finding of "Modic changes" has been identified as pathologic spinal condition that probably reflects a vertebral inflammatory process (VIP), which coincides with spinal pain in most. We hypothesized that heavy smoking in combination with macro- or repeated microtrauma could lead to VIP. The objectives were to investigate if combinations of self-reported heavy smoking, hard physical work, and overweight would be more strongly linked with VIP than with other spinal conditions, such as degenerated discs and non-specific low back pain (LBP). Secondary analysis was made of a data base pertaining to a population-based cross-sectional study. A population-generated cohort of 412 40-yr old Danes provided questionnaire information on smoking, weight, height, type of work, and LBP. MRI was used to determine the presence/absence of disc degeneration and of VIP. Associations were tested between three explanatory variables (type of work, smoking, and body mass index) and four outcome variables (LBP in the past year, more persistent LBP in the past year, disc degeneration, and VIP). Associations with these four outcome variables were studied for each single explanatory variable and for combinations of two at a time, and, finally, in a multivariable analysis including all three explanatory variables. There were no significant associations between the single explanatory variables and the two pain variables or with disc degeneration. However, VIP was found in 15% of non-smokers vs. 26% of heavy smokers. Similarly, VIP was noted in 11% of those in sedentary jobs vs. 31% of those with hard physical work. Further, the prevalence of VIP in those, who neither smoked heavily nor had a hard physical job was 13%, 25% in those who either smoked heavily or had a hard physical job, and 41% in those who both smoked heavily and worked hard. The odds ratio was 4.9 (1.6-13.0) for those who were both heavy smokers and had a hard physical job as compared to those who were

Self-reported hard physical work combined with heavy smoking or overweight may result in so-called Modic changes

Directory of Open Access Journals (Sweden)

Bendix Tom

2008-01-01

Full Text Available Abstract Background Recently, the MRI finding of "Modic changes" has been identified as pathologic spinal condition that probably reflects a vertebral inflammatory process (VIP, which coincides with spinal pain in most. We hypothesized that heavy smoking in combination with macro- or repeated microtrauma could lead to VIP. The objectives were to investigate if combinations of self-reported heavy smoking, hard physical work, and overweight would be more strongly linked with VIP than with other spinal conditions, such as degenerated discs and non-specific low back pain (LBP. Methods Secondary analysis was made of a data base pertaining to a population-based cross-sectional study. A population-generated cohort of 412 40-yr old Danes provided questionnaire information on smoking, weight, height, type of work, and LBP. MRI was used to determine the presence/absence of disc degeneration and of VIP. Associations were tested between three explanatory variables (type of work, smoking, and body mass index and four outcome variables (LBP in the past year, more persistent LBP in the past year, disc degeneration, and VIP. Associations with these four outcome variables were studied for each single explanatory variable and for combinations of two at a time, and, finally, in a multivariable analysis including all three explanatory variables. Results There were no significant associations between the single explanatory variables and the two pain variables or with disc degeneration. However, VIP was found in 15% of non-smokers vs. 26% of heavy smokers. Similarly, VIP was noted in 11% of those in sedentary jobs vs. 31% of those with hard physical work. Further, the prevalence of VIP in those, who neither smoked heavily nor had a hard physical job was 13%, 25% in those who either smoked heavily or had a hard physical job, and 41% in those who both smoked heavily and worked hard. The odds ratio was 4.9 (1.6–13.0 for those who were both heavy smokers and had a hard

Teste de estimulação repetitiva no músculo ancôneo para diagnóstico da miastenia grave: mapeamento da sua área de placa motora Repetitive stimulation test on the anconeus muscle for the diagnosis of myasthenia gravis: the mapping of its motor end-plate area

Directory of Open Access Journals (Sweden)

Maria das Graças Wanderley S. Coriolano

2007-06-01

Full Text Available OBJETIVO: Mapear a área de placa motora do músculo ancôneo para definir a melhor localização dos eletrodos de registro em testes de estimulação repetitiva (TER no diagnóstico dos distúrbios da transmissão neuromuscular. MÉTODO: Registramos o potencial de ação composto do músculo ancôneo sobre a pele que o recobre, após estimulação do ramo que o inerva. Analisando as formas de onda registradas em cada ponto da pele foi possível definir a área de placa. RESULTADOS: A área de placa motora do ancôneo é uma linha paralela à borda da ulna. O melhor local de colocação do eletrodo "ativo" de registro situa-se cerca de 2 cm distal ao olécrano e 1 cm lateral à borda da ulna. CONCLUSÃO: A realização de TER no músculo ancôneo é simples e bem tolerada. Com a estimulação do ancôneo o antebraço praticamente não se move, sendo o procedimento livre de artefatos de movimento.PURPOSE: To map the motor end-plate area of the anconeus muscle and define the best place for positioning the recording electrodes in repetitive stimulation tests (RST for the diagnosis of neuromuscular transmission disorders. METHOD: The compound muscle action potential of the anconeus was recorded after stimulating the motor branch of the radial nerve that innervates it. By analyzing the waveforms registered at each point of the skin we were able to define the motor end-plate area. RESULTS: The motor end-plate area of the anconeus is a line parallel to the ulna border. The best place for placing the "active" recording electrode is about 2cm distal to the olecranon and 1 cm lateral to the border of the ulna. CONCLUSION: Performing RST in the anconeus muscle is simple and well tolerated. Stimulation of the anconeus almost doesn't move the forearm and the procedure is virtually free of movement artifacts.

Lumbar internal disc derangement in patients with chronic low back pain: diagnostic value of the MR imaging findings as compared with provoked discography as the standard

Energy Technology Data Exchange (ETDEWEB)

Park, Hyeon Seon; Park, Jee Young; Lee, Sang Ho; Ahn, Yong [Wooridul spine Hospital, Seoul (Korea, Republic of); Lee, Sang Yeun [Puchon Daesung Hospital, Puchon (Korea, Republic of)

2006-04-15

The aim of this study was to evaluate the diagnostic value of the MR imaging findings with provoked discography used as the standard for painful lumbar disc derangement. Two hundred patients (412 discs), (age rang: 21-77 year), with chronic low back pain underwent MRI and provoked discography. We evaluated the MRI T2-WI findings such as disc degeneration, high-Intensity zones and endplate abnormalities. Subsequently, provocative discography was independently performed with using MR imaging, and a painful disc was defined when moderate to severe and concordant pain was provoked. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the MRI findings with using provoked discography as the standard. 400 discs showed abnormal findings such as disc degeneration, HIZ and endplate abnormalities on the T2-WI images. 12 discs showed normal finding. HIZ or endplate abnormalities were always combined with disc degeneration. The prevalence of each findings were disc degeneration (400 discs: 97.1%), HIZ (111 discs: 26.9%), type I endplate abnormalities (34 discs: 8.3%), type II endplate abnormalities (75 discs: 18.2%), the combined findings of HIZ and type I endplate abnormalities (2 discs: 0.5%) and the combined findings of HIZ and type II endplate abnormalities (7 discs: 1.7%). The disc degeneration showed high sensitivity (99.5%) and low specificity (5.0%), so only the NPV (91.7%) was significant, and not the PPV (47.8%). Each findings of HIZ (sensitivity, 36.5%, specificity, 81.4%; PPV, 63.18%; NPV, 59.5%), type I endplate abnormalities (11.0%, 94.1%, 61.8% and 54.8%, respectively), type II endplate abnormalities (19.8%, 83.2%, 50.7% and 54.3%, respectively), the combined findings of HIZ and type I endplate abnormalities (0.5%, 99.6%, 50.0% and 53.4%, respectively) and the combined findings of HIZ and type II endplate abnormalities (26.0%, 99.1%, 71.4% and 53.8%, respectively) show high specificity, but low

Lumbar internal disc derangement in patients with chronic low back pain: diagnostic value of the MR imaging findings as compared with provoked discography as the standard

International Nuclear Information System (INIS)

Park, Hyeon Seon; Park, Jee Young; Lee, Sang Ho; Ahn, Yong; Lee, Sang Yeun

2006-01-01

The aim of this study was to evaluate the diagnostic value of the MR imaging findings with provoked discography used as the standard for painful lumbar disc derangement. Two hundred patients (412 discs), (age rang: 21-77 year), with chronic low back pain underwent MRI and provoked discography. We evaluated the MRI T2-WI findings such as disc degeneration, high-Intensity zones and endplate abnormalities. Subsequently, provocative discography was independently performed with using MR imaging, and a painful disc was defined when moderate to severe and concordant pain was provoked. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the MRI findings with using provoked discography as the standard. 400 discs showed abnormal findings such as disc degeneration, HIZ and endplate abnormalities on the T2-WI images. 12 discs showed normal finding. HIZ or endplate abnormalities were always combined with disc degeneration. The prevalence of each findings were disc degeneration (400 discs: 97.1%), HIZ (111 discs: 26.9%), type I endplate abnormalities (34 discs: 8.3%), type II endplate abnormalities (75 discs: 18.2%), the combined findings of HIZ and type I endplate abnormalities (2 discs: 0.5%) and the combined findings of HIZ and type II endplate abnormalities (7 discs: 1.7%). The disc degeneration showed high sensitivity (99.5%) and low specificity (5.0%), so only the NPV (91.7%) was significant, and not the PPV (47.8%). Each findings of HIZ (sensitivity, 36.5%, specificity, 81.4%; PPV, 63.18%; NPV, 59.5%), type I endplate abnormalities (11.0%, 94.1%, 61.8% and 54.8%, respectively), type II endplate abnormalities (19.8%, 83.2%, 50.7% and 54.3%, respectively), the combined findings of HIZ and type I endplate abnormalities (0.5%, 99.6%, 50.0% and 53.4%, respectively) and the combined findings of HIZ and type II endplate abnormalities (26.0%, 99.1%, 71.4% and 53.8%, respectively) show high specificity, but low

Investigation of Plasma Eects in Ultra High Molecular Weight Polyethylene (UHMWPE) Cords

DEFF Research Database (Denmark)

Teodoru, Steluta; Kusano, Yukihiro; Rozlosnik, Noemi

modication for improved wetting and/or adhesion with other polymeric materials. Atmospheric pressure plasma treatment is promising for this purpose due to its environmental compatibility, high treatment eects without aecting the textural characteristics of the bulk material, its applicability to a variety...... of shapes, and easy up-scaling and construction of in-line production processes. An atmospheric pressure dielectric barrier discharge (DBD) plasma is used to study surface modication eect on UHMWPE cords, operated at a frequency of ca. 40 kHz in He, He/O2, O2 and N2 gases. The cords were continuously...

Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis - comparing two different image evaluation methods

International Nuclear Information System (INIS)

Berg, Linda; Espeland, Ansgar; Gjertsen, Oeivind; Hellum, Christian; Neckelmann, Gesche; Johnsen, Lars G.; Eide, Geir E.

2012-01-01

To assess the reliability of change in lumbar magnetic resonance imaging (MRI) findings evaluated retrospectively by direct comparison of images and by non-comparison. Pre-treatment and 2-year follow-up MRI was performed in 126 patients randomized to disc prosthesis surgery or non-surgical treatment. Two experienced radiologists independently evaluated progress and regress for Modic changes, disc findings, and facet arthropathy (FA) at L3/L4, L4/L5, and L5/S1, both by non-comparison and by comparison of initial and follow-up images. FA was evaluated at all levels, and other findings at non-operated levels. We calculated prevalence- and bias-adjusted kappa (PABAK) values for interobserver agreement. The impact of an adjacent prosthesis (which causes artefacts) and image evaluation method on PABAK was assessed using generalized estimating equations. Image comparison indicated good interobserver agreement on progress and regress (PABAK 0.63-1.00) for Modic changes, posterior high-intensity zone, disc height, and disc contour at L3-S1 and for nucleus pulposus signal and FA at L3/L4; and moderate interobserver agreement (PABAK 0.46-0.59) on decreasing nucleus signal and increasing FA at L4-S1. Image comparison indicated lower (but fair) interobserver agreement (PABAK 0.29) only for increasing FA at L5/S1 in patients with prosthesis in L4/L5 and/or L5/S1. An adjacent prosthesis had no overall impact on PABAK values (p ≥ 0.22). Comparison yielded higher PABAK values than non-comparison (p < 0.001). Regarding changes in lumbar MRI findings over time, comparison of images can provide moderate or good interobserver agreement, and better agreement than non-comparison. An adjacent prosthesis may not reduce agreement on change for most findings. (orig.)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-15

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

Cartilage of the Intervertebral Disc Eng-Plate, A Histological, Histochemical, Fine Structure Study.

Science.gov (United States)

1982-08-01

degeneration (Nachemson et al., 1970). These and related studies consider the end-plates to be composed of hyaline cartilage and thus homologues of articular...results of this study in rhesus indicate, that while present, the cartilage of the end-plate is quite different in structure and presumably...HZSTOLO6ZCAL,-ETCfU) I AUG 82 N 5 NUSSBAUM IUNCLASSIFDATRL8R-1222NL.rnximommmB~iIEND2 AFAMRL-TR-81 - 122 " CARTILAGE OF THE INTERVERTEBRAL DISC END-PLATE A

Reliability of MRI findings in candidates for lumbar disc prosthesis

International Nuclear Information System (INIS)

Berg, Linda; Espeland, Ansgar; Neckelmann, Gesche; Gjertsen, Oeivind; Hellum, Christian; Johnsen, Lars G.; Eide, Geir E.

2012-01-01

Limited reliability data exist for localised magnetic resonance imaging (MRI) findings relevant to planning of treatment with lumbar disc prosthesis and later outcomes. We assessed the reliability of such findings in chronic low back pain patients who were accepted candidates for disc prosthesis. On pretreatment MRI of 170 patients (mean age 41 years; 88 women), three experienced radiologists independently rated Modic changes, disc findings and facet arthropathy at L3/L4, L4/L5 and L5/S1. Two radiologists rerated 126 examinations. For each MRI finding at each disc level, agreement was analysed using the kappa statistic and differences in prevalence across observers using a fixed effects model. All findings at L3/L4 and facet arthropathy at L5/S1 had a mean prevalence <10% across observers and were not further analysed, ensuring interpretable kappa values. Overall interobserver agreement was generally moderate or good (kappa 0.40-0.77) at L4-S1 for Modic changes, nucleus pulposus signal, disc height (subjective and measured), posterior high-intensity zone (HIZ) and disc contour, and fair (kappa 0.24) at L4/L5 for facet arthropathy. Posterior HIZ at L5/S1 and severely reduced subjective disc height at L4/L5 differed up to threefold in prevalence between observers (p < 0.0001). Intraobserver agreement was mostly good or very good (kappa 0.60-1.00). In candidates for disc prosthesis, mostly moderate interobserver agreement is expected for localised MRI findings. (orig.)

Reliability of MRI findings in candidates for lumbar disc prosthesis

Energy Technology Data Exchange (ETDEWEB)

Berg, Linda; Espeland, Ansgar [Haukeland University Hospital, Department of Radiology, Bergen (Norway); University of Bergen, Section for Radiology, Department of Surgical Sciences, Bergen (Norway); Neckelmann, Gesche [Haukeland University Hospital, Department of Radiology, Bergen (Norway); Gjertsen, Oeivind [Oslo University Hospital, Department of Neuroradiology, Oslo (Norway); Hellum, Christian [Oslo University Hospital, Department of Orthopaedics, Oslo (Norway); University of Oslo, Department of Orthopaedics, Oslo (Norway); Johnsen, Lars G. [University Hospital of Trondheim, National Centre for Diseases of the Spine, Trondheim (Norway); University Hospital of Trondheim, Orthopaedic Department, Trondheim (Norway); Eide, Geir E. [Haukeland University Hospital, Centre for Clinical Research, Bergen (Norway); University of Bergen, Department of Public Health and Primary Health Care, Bergen (Norway)

2012-07-15

Limited reliability data exist for localised magnetic resonance imaging (MRI) findings relevant to planning of treatment with lumbar disc prosthesis and later outcomes. We assessed the reliability of such findings in chronic low back pain patients who were accepted candidates for disc prosthesis. On pretreatment MRI of 170 patients (mean age 41 years; 88 women), three experienced radiologists independently rated Modic changes, disc findings and facet arthropathy at L3/L4, L4/L5 and L5/S1. Two radiologists rerated 126 examinations. For each MRI finding at each disc level, agreement was analysed using the kappa statistic and differences in prevalence across observers using a fixed effects model. All findings at L3/L4 and facet arthropathy at L5/S1 had a mean prevalence <10% across observers and were not further analysed, ensuring interpretable kappa values. Overall interobserver agreement was generally moderate or good (kappa 0.40-0.77) at L4-S1 for Modic changes, nucleus pulposus signal, disc height (subjective and measured), posterior high-intensity zone (HIZ) and disc contour, and fair (kappa 0.24) at L4/L5 for facet arthropathy. Posterior HIZ at L5/S1 and severely reduced subjective disc height at L4/L5 differed up to threefold in prevalence between observers (p < 0.0001). Intraobserver agreement was mostly good or very good (kappa 0.60-1.00). In candidates for disc prosthesis, mostly moderate interobserver agreement is expected for localised MRI findings. (orig.)

Qualitative grading of disc degeneration by magnetic resonance in the lumbar and cervical spine: lack of correlation with histology in surgical cases.

Science.gov (United States)

Davies, B M; Atkinson, R A; Ludwinski, F; Freemont, A J; Hoyland, J A; Gnanalingham, K K

2016-08-01

Clinically, magnetic resonance (MR) imaging is the most effective non-invasive tool for assessing IVD degeneration. Histological examination of the IVD provides a more detailed assessment of the pathological changes at a tissue level. However, very few reports have studied the relationship between these techniques. Identifying a relationship may allow more detailed staging of IVD degeneration, of importance in targeting future regenerative therapies. To investigate the relationship between MR and histological grading of IVD degeneration in the cervical and lumbar spine in patients undergoing discectomy. Lumbar (N = 99) and cervical (N = 106) IVD samples were obtained from adult patients undergoing discectomy surgery for symptomatic IVD herniation and graded to ascertain a histological grade of degeneration. The pre-operative MR images from these patients were graded for the degree of IVD (MR grade) and vertebral end-plate degeneration (Modic Changes, MC). The relationship between histological and MR grades of degeneration were studied. In lumbar and cervical IVD the majority of samples (93%) exhibited moderate levels of degeneration (ie MR grades 3-4) on pre-operative MR scans. Histologically, most specimens displayed moderate to severe grades of degeneration in lumbar (99%) and cervical spine (93%). MR grade was weakly correlated with patient age in lumbar and cervical study groups. MR and histological grades of IVD degeneration did not correlate in lumbar or cervical study groups. MC were more common in the lumbar than cervical spine (e.g. 39 versus 20% grade 2 changes; p < 0.05), but failed to correlate with MR or histological grades for degeneration. In this surgical series, the resected IVD tissue displayed moderate to severe degeneration, but there is no correlation between MR and histological grades using a qualitative classification system. There remains a need for a quantitative, non-invasive, pre-clinical measure of IVD degeneration that

Effect of Interbody Fusion on the Remaining Discs of the Lumbar Spine in Subjects with Disc Degeneration.

Science.gov (United States)

Ryu, Robert; Techy, Fernando; Varadarajan, Ravikumar; Amirouche, Farid

2016-02-01

To study effects (stress loads) of lumbar fusion on the remaining segments (adjacent or not) of the lumbar spine in the setting of degenerated adjacent discs. A lumbar spine finite element model was built and validated. The full model of the lumbar spine was a parametric finite element model of segments L 1-5 . Numerous hypothetical combinations of one-level lumbar spine fusion and one-level disc degeneration were created. These models were subjected to 10 Nm flexion and extension moments and the stresses on the endplates and consequently on the intervertebral lumbar discs measured. These values were compared to the stresses on healthy lumbar spine discs under the same load and fusion scenarios. Increased stress at endplates was observed only in the settings of L4-5 fusion and L3-4 disc degeneration (8% stress elevation at L2,3 in flexion or extension, and 25% elevation at L3,4 in flexion only). All other combinations showed less endplate stress than did the control model. For fusion at L3-4 and degeneration at L4-5 , the stresses in the endplates at the adjacent level inferior to the fused disc decreased for both loading disc height reductions. Stresses in flexion decreased after fusion by 29.5% and 25.8% for degeneration I and II, respectively. Results for extension were similar. For fusion at L2-3 and degeneration at L4-5 , stresses in the endplates decreased more markedly at the degenerated (30%), than at the fused level (14%) in the presence of 25% disc height reduction and 10 Nm flexion, whereas in extension stresses decreased more at the fused (24.3%) than the degenerated level (5.86%). For fusion at L3-4 and degeneration at L2-3 , there were no increases in endplate stress in any scenario. For fusion at L4-5 and degeneration at L3-4 , progression of degeneration from I to II had a significant effect only in flexion. A dramatic increase in stress was noted in the endplates of the degenerated disc (L3-4 ) in flexion for degeneration II. Stresses are greater

3D Ultrashort TE MRI for Evaluation of Cartilaginous Endplate of Cervical Disk In Vivo: Feasibility and Correlation With Disk Degeneration in T2-Weighted Spin-Echo Sequence.

Science.gov (United States)

Kim, Yeo Ju; Cha, Jang Gyu; Shin, Yoon Sang; Chaudhari, Akshay S; Suh, Young Ju; Hwan Yoon, Seung; Gold, Garry E

2018-05-01

The purpose of this study was to evaluate the feasibility of 3D ultrashort TE (UTE) MRI in depicting the cartilaginous endplate (CEP) and its abnormalities and to investigate the association between CEP abnormalities and disk degeneration on T2-weighted spin-echo (SE) MR images in cervical disks in vivo. Eight healthy volunteers and 70 patients were examined using 3-T MRI with the 3D UTE cones trajectory technique (TR/TE, 16.1/0.032, 6.6). In the volunteer study, quantitative and qualitative assessments of CEP depiction were conducted for the 3D UTE and T2-weighted SE imaging. In the patient study, CEP abnormalities were analyzed. Intersequence agreement between the images obtained with the first-echo 3D UTE sequence and the images created by subtracting the second-echo from the first-echo 3D UTE sequence (subtracted 3D UTE) and the intraobserver and interobserver agreements for 3D UTE overall were also tested. The CEP abnormalities on the 3D UTE images correlated with the Miyazaki grading of the T2-weighted SE images. In the volunteer study, the CEP was well visualized on 3D UTE images but not on T2-weighted SE images (p evaluation of CEP abnormalities, intersequence agreements were substantial to almost perfect, intraobserver agreements were substantial to almost perfect, and interobserver agreements were moderate to substantial (p T2-weighted SE MRI.

MRI in patients with tuberculous spondylitis presenting as vertebra plana: A retrospective analysis and review of literature

International Nuclear Information System (INIS)

Sureka, J.; Samuel, S.; Keshava, S.N.; Venkatesh, K.; Sundararaj, G.D.

2013-01-01

Aim: To present the magnetic resonance imaging (MRI) findings of 10 patients with histopathologically proven tuberculous spondylitis (TS) presenting as vertebra plana (VP) on radiographs. Material and methods: Radiographs of 451 adult TS patients were reviewed. In this consecutive series, there were 11 patients who presented as VP. MRI of 10 of these patients was available for review. Results: VP-like collapse of a single vertebral body of the dorsal spine with preserved endplates and disc was seen in all cases. Epidural, pre- and para-vertebral soft tissue was found in all patients. Epidural soft tissue presenting on sagittal images as a convexity of the posterior longitudinal ligament was also found in all the signal of which was different from the involved vertebra on axial images. All patients showed posterior element involvement, which was characterized by preserved cortical outline without expansion. Conclusion: TS presenting with VP-like collapse of the bone is rare, accounting for 2.4% of the cases in the present series. MRI may show a collapsed vertebra with preserved endplates and disc. MRI findings that are suggestive of TS include: (1) signal intensity of the epidural soft-tissue mass on axial images, which is different from the vertebral body; (2) presence of a thin, T2-weighted hypointense capsule of the para-vertebral soft tissue; (3) posterior element involvement characterized by intact hypointense cortical outline without expansion; and (4) involvement of the costovertebral joint.

Manual and computerized measurement of coronal vertebral inclination on MRI images: A pilot study

International Nuclear Information System (INIS)

Vrtovec, T.; Likar, B.; Pernuš, F.

2013-01-01

Aim: A pilot study that presents a systematic approach for evaluating the variability of manual and computerized measurements of coronal vertebral inclination (CVI) on images acquired by magnetic resonance imaging (MRI). Materials and methods: Three observers identified the vertebral body corners of 28 vertebrae on two occasions on two-dimensional (2D) coronal MRI cross-sections, which served to evaluate CVI using six manual measurements (superior and inferior tangents, left and right tangents, mid-endplate and mid-wall lines). Computerized measurements were performed by evaluating CVI from the symmetry of vertebral anatomical structures of the same 28 vertebrae in 2D coronal MRI cross-sections and in three-dimensional (3D) MRI images. Results: In terms of standard deviation (SD), the mid-endplate lines proved to be the manual measurements with the lowest intra- (1.0° SD) and interobserver (1.4° SD) variability. The computerized measurements in 3D yielded even lower intra- (0.8° SD) and interobserver (1.3° SD) variability. The strongest inter-method agreement (1.2° SD) was found among lines parallel to vertebral endplates (superior tangents, inferior tangents, mid-endplate lines). The computerized measurements in 3D were most in agreement with the mid-endplate lines (1.9° SD). The estimated intra- and interobserver variabilities of standard Cobb angle measurements were equal to 1.6° SD and 2.5° SD, respectively, for manual measurements, and to 1.1° SD and 1.8° SD, respectively, for computerized measurements. Conclusion: The mid-endplate lines proved to be the most reproducible and reliable manual CVI measurements. Computerized CVI measurements based on the evaluation of the symmetry of vertebral anatomical structures in 3D were more reproducible and reliable than manual measurements

Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations

Directory of Open Access Journals (Sweden)

A. M. Durigon

2005-03-01

Full Text Available The pharmacological effects of Bothrops neuwiedi pauloensis venom on mouse phrenic nerve-diaphragm (PND preparations were studied. Venom (20 mug/ml irreversibly inhibited indirectly evoked twitches in PND preparations (60 ± 10% inhibition, mean ± SEM; p<0.05; n=6. At 50 mug/ml, the venom blocked indirectly and directly (curarized preparations evoked twitches in mouse hemidiaphragms. In the absence of Ca2+, venom (50 mug/ml, produced partial blockade only after an 80 min incubation, which reached 40.3 ± 7.8% (p<0.05; n=3 after 120 min. Venom (20 mug/ml increased (25 ± 2%, p< 0.05 the frequency of giant miniature end-plate potentials in 9 of 10 end-plates after 30 min and the number of miniature end-plate potentials which was maximum (562 ± 3%, p<0.05 after 120 min. During the same period, the resting membrane potential decreased from - 81 ± 1.4 mV to - 41.3 ± 3.6 mV 24 fibers; p<0.01; n=4 in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p<0.01; n=4 in regions distant from the end-plate. These results indicate that B. n. pauloensis venom acts primarily at presynaptic sites. They also suggest that enzymatic activity may be involved in this pharmacological action.

Multiple Actions of Rotenone, an Inhibitor of Mitochondrial Respiratory Chain, on Ionic Currents and Miniature End-Plate Potential in Mouse Hippocampal (mHippoE-14 Neurons

Directory of Open Access Journals (Sweden)

Chin-Wei Huang

2018-05-01

Full Text Available Background/Aims: Rotenone (Rot is known to suppress the activity of complex I in the mitochondrial chain reaction; however, whether this compound has effects on ion currents in neurons remains largely unexplored. Methods: With the aid of patch-clamp technology and simulation modeling, the effects of Rot on membrane ion currents present in mHippoE-14 cells were investigated. Results: Addition of Rot produced an inhibitory action on the peak amplitude of INa with an IC50 value of 39.3 µM; however, neither activation nor inactivation kinetics of INa was changed during cell exposure to this compound. Addition of Rot produced little or no modifications in the steady-state inactivation curve of INa. Rot increased the amplitude of Ca2+-activated Cl- current in response to membrane depolarization with an EC50 value of 35.4 µM; further addition of niflumic acid reversed Rot-mediated stimulation of this current. Moreover, when these cells were exposed to 10 µM Rot, a specific population of ATP-sensitive K+ channels with a single-channel conductance of 18.1 pS was measured, despite its inability to alter single-channel conductance. Under current clamp condition, the frequency of miniature end-plate potentials in mHippoE-14 cells was significantly raised in the presence of Rot (10 µM with no changes in their amplitude and time course of rise and decay. In simulated model of hippocampal neurons incorporated with chemical autaptic connection, increased autaptic strength to mimic the action of Rot was noted to change the bursting pattern with emergence of subthreshold potentials. Conclusions: The Rot effects presented herein might exert a significant action on functional activities of hippocampal neurons occurring in vivo.

Coléoptères nouveaux de l’Afrique du Musée de Leyde

NARCIS (Netherlands)

Fairmaire, L.

1888-01-01

Long. 22 à 25 mill. — Elongatus, convexus, fuscus aut brunneo-castaneus, modice nitidus, fulvo-pubescens; capite dense punctato, inter oculos sat late impresso, antice declivi, margine obtuse rotundato; antennis fuscis, medium corporis attingentibus, articulo 1° punctato, 2° minuto, 3° vix majore,

On irregularity strength of disjoint union of friendship graphs

Directory of Open Access Journals (Sweden)

Ali Ahmad

2013-11-01

Full Text Available We investigate the vertex total and edge total modication of the well-known irregularity strength of graphs. We have determined the exact values of the total vertex irregularity strength and the total edge irregularity strength of a disjoint union of friendship graphs.

Prospective evaluation of contrast-enhanced MR imaging after uncomplicated lumbar discography

International Nuclear Information System (INIS)

Carrino, John A.; Swathwood, Todd C.; Morrison, William B.; Glover, J.M.

2007-01-01

Postdiscography infection is an uncommon complication. Magnetic resonance (MR) imaging is often the modality of choice for evaluating spinal infection. Discography entails disc access and fluid injection that could alter the baseline MR imaging appearance of the spine and be confounded for infection. Our purpose was to describe the MR imaging findings of the lumbar spine subsequent to uncomplicated discography and to determine if this may mimic infection. In a prospective cohort study of eight adults (age 22-64 years, mean 45 years) with 22 intradiscal injections, all subjects underwent routine unenhanced and contrast-enhanced MR imaging during the 2-3 week interval postdiscography. A subset of four returned for additional MR imaging during the 4-8 week interval postdiscography. MR images were reviewed for intradiscal, endplate, marrow, and epidural findings and then compared with prediscography examinations. Infection was excluded by clinical documentation. Postdiscography MR imaging showed that almost all levels were similar to baseline prediscography examinations. No levels developed new vertebral marrow edema, fluid-like intradiscal signal, endplate irregularity, or epidural abnormality. Two subjects simulated potential discitis, but these findings were unchanged from prediscography and were related to prior surgery. Uncomplicated lumbar spine discography does not cause MR imaging changes that simulate discitis. (orig.)

Prospective evaluation of contrast-enhanced MR imaging after uncomplicated lumbar discography

Energy Technology Data Exchange (ETDEWEB)

Carrino, John A. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Outpatient Center, Baltimore, MD (United States); Swathwood, Todd C. [Blue Ridge Orthopedic Associates, Seneca (United States); Morrison, William B. [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Glover, J.M. [Northern Arizona Orthopaedics, Flagstaff, AZ (United States)

2007-04-15

Postdiscography infection is an uncommon complication. Magnetic resonance (MR) imaging is often the modality of choice for evaluating spinal infection. Discography entails disc access and fluid injection that could alter the baseline MR imaging appearance of the spine and be confounded for infection. Our purpose was to describe the MR imaging findings of the lumbar spine subsequent to uncomplicated discography and to determine if this may mimic infection. In a prospective cohort study of eight adults (age 22-64 years, mean 45 years) with 22 intradiscal injections, all subjects underwent routine unenhanced and contrast-enhanced MR imaging during the 2-3 week interval postdiscography. A subset of four returned for additional MR imaging during the 4-8 week interval postdiscography. MR images were reviewed for intradiscal, endplate, marrow, and epidural findings and then compared with prediscography examinations. Infection was excluded by clinical documentation. Postdiscography MR imaging showed that almost all levels were similar to baseline prediscography examinations. No levels developed new vertebral marrow edema, fluid-like intradiscal signal, endplate irregularity, or epidural abnormality. Two subjects simulated potential discitis, but these findings were unchanged from prediscography and were related to prior surgery. Uncomplicated lumbar spine discography does not cause MR imaging changes that simulate discitis. (orig.)

Modified Normal Demand Distributions in (R,S)-Inventory Models

NARCIS (Netherlands)

Strijbosch, L.W.G.; Moors, J.J.A.

2003-01-01

To model demand, the normal distribution is by far the most popular; the disadvantage that it takes negative values is taken for granted.This paper proposes two modi.cations of the normal distribution, both taking non-negative values only.Safety factors and order-up-to-levels for the familiar (R,

New Materials = New Expressive Powers: Smart Material Interfaces and Arts, experience via smart materials

NARCIS (Netherlands)

Minuto, A.; Pittarello, Fabio; Nijholt, Antinus

2014-01-01

It is not easy for a growing artist to find his poetry. Smart materials could be an answer for those who are looking for new forms of art. Smart Material Interfaces (SMI) define a new interaction paradigm based on dynamic modications of the innovative materials' properties. SMI can be applied in

Low virulence bacterial infections in cervical intervertebral discs: a prospective case series.

Science.gov (United States)

Chen, Yilei; Wang, Xianjun; Zhang, Xuyang; Ren, Hong; Huang, Bao; Chen, Jian; Liu, Junhui; Shan, Zhi; Zhu, Zhihai; Zhao, Fengdong

2018-04-19

A prospective cross-sectional case series study. To investigate the prevalence of low virulence disc infection and its associations with characteristics of patients or discs in the cervical spine. Low virulence bacterial infections could be a possible cause of intervertebral disc degeneration and/or back pain. Controversies are continuing over whether these bacteria, predominantly Propionibacterium acnes (P. acnes), represent infection or contamination. However, the current studies mainly focus on the lumbar spine, with very limited data on the cervical spine. Thirty-two patients (20 men and 12 women) who underwent anterior cervical fusion for degenerative cervical spondylosis or traumatic cervical cord injury were enrolled. Radiological assessments included X-ray, CT, and MRI of the cervical spine. Endplate Modic changes, intervertebral range of motion, and disc herniation type were evaluated. Disc and muscle tissues were collected under strict sterile conditions. Samples were enriched in tryptone soy broth and subcultured under anaerobic conditions, followed by identification of the resulting colonies by the PCR method. Sixty-six intervertebral discs were excised from thirty-two patients. Positive disc cultures were noted in eight patients (25%) and in nine discs (13.6%). The muscle biopsy (control) cultures were negative in 28 patients and positive in 4 patients (12.5%); three of whom had a negative disc culture. Seven discs (10.6%) were positive for coagulase-negative Staphylococci (CNS) and two discs were positive for P. acnes (3.0%). A younger patient age and the extrusion or sequestration type of disc herniation, which represented a complete annulus fibrous failure, were associated with positive disc culture. Our data show that CNS is more prevalent than P. acnes in degenerative cervical discs. The infection route in cervical discs may be predominantly through an annulus fissure. Correlation between these infections and clinical symptoms is uncertain

Experimental Investigation of a Wing-in-Ground Effect Craft

Directory of Open Access Journals (Sweden)

M. Mobassher Tofa

2014-01-01

Full Text Available The aerodynamic characteristics of the wing-in-ground effect (WIG craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Experimental investigation of a wing-in-ground effect craft.

Science.gov (United States)

Tofa, M Mobassher; Maimun, Adi; Ahmed, Yasser M; Jamei, Saeed; Priyanto, Agoes; Rahimuddin

2014-01-01

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Mechanisms of hydrogen sulfide (H2S) action on synaptic transmission at the mouse neuromuscular junction.

Science.gov (United States)

Gerasimova, E; Lebedeva, J; Yakovlev, A; Zefirov, A; Giniatullin, R; Sitdikova, G

2015-09-10

Hydrogen sulfide (H2S) is a widespread gasotransmitter also known as a powerful neuroprotective agent in the central nervous system. However, the action of H2S in peripheral synapses is much less studied. In the current project we studied the modulatory effects of the H2S donor sodium hydrosulfide (NaHS) on synaptic transmission in the mouse neuromuscular junction using microelectrode technique. Using focal recordings of presynaptic response and evoked transmitter release we have shown that NaHS (300 μM) increased evoked end-plate currents (EPCs) without changes of presynaptic waveforms which indicated the absence of NaHS effects on sodium and potassium currents of motor nerve endings. Using intracellular recordings it was shown that NaHS increased the frequency of miniature end-plate potentials (MEPPs) without changing their amplitudes indicating a pure presynaptic effect. Furthermore, NaHS increased the amplitude of end-plate potentials (EPPs) without influencing the resting membrane potential of muscle fibers. L-cysteine, a substrate of H2S synthesis induced, similar to NaHS, an increase of EPC amplitudes whereas inhibitors of H2S synthesis (β-cyano-L-alanine and aminooxyacetic acid) had the opposite effect. Inhibition of adenylate cyclase using MDL 12,330A hydrochloride (MDL 12,330A) or elevation of cAMP level with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (pCPT-cAMP) completely prevented the facilitatory action of NaHS indicating involvement of the cAMP signaling cascade. The facilitatory effect of NaHS was significantly diminished when intracellular calcium (Ca(2+)) was buffered by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester (EGTA-AM). Activation of ryanodine receptors by caffeine or ryanodine increased acetylcholine release and prevented further action of NaHS on transmitter release, likely due to

Development of Ultrasound to Measure In-vivo Dynamic Cervical Spine Intervertebral Disc Mechanics

Science.gov (United States)

2014-01-01

The deformation between C4 and C6 measured by the US probe was affected by bulging of the IVD and soft tissues during compressive loading as...endplates of the vertebrae and cartilaginous endplate of the discs were added to all segments. Figure 28 Coronal views of the updated C4-T1 FEM (a...the ligaments and soft tissue connections that provide stability to the cervical spine FSUs were added (Figures 30 and 31). For the anterior

Transmitter release in the neuromuscular synapse of the protein kinase C theta-deficient adult mouse.

Science.gov (United States)

Besalduch, Núria; Santafé, Manel M; Garcia, Neus; Gonzalez, Carmen; Tomás, Marta; Tomás, Josep; Lanuza, Maria A

2011-04-01

We studied structural and functional features of the neuromuscular junction in adult mice (P30) genetically deficient in the protein kinase C (PKC) theta isoform. Confocal and electron microscopy shows that there are no differences in the general morphology of the endplates between PKC theta-deficient and wild-type (WT) mice. Specifically, there is no difference in the density of the synaptic vesicles. However, the myelin sheath is not as thick in the intramuscular nerve fibers of the PKC theta-deficient mice. We found a significant reduction in the size of evoked endplate potentials and in the frequency of spontaneous, asynchronous, miniature endplate potentials in the PKC theta-deficient neuromuscular preparations in comparison with the WT, but the mean amplitude of the spontaneous potentials is not different. These changes indicate that PKC theta has a presynaptic role in the function of adult neuromuscular synapses. Copyright © 2010 Wiley-Liss, Inc.

Nerve terminal contributes to acetylcholine receptor organization at the dystrophic neuromuscular junction of mdx mice.

Science.gov (United States)

Marques, Maria Julia; Taniguti, Ana Paula Tiemi; Minatel, Elaine; Neto, Humberto Santo

2007-02-01

Changes in the distribution of acetylcholine receptors have been reported to occur at the neuromuscular junction of mdx mice and may be a consequence of muscle fiber regeneration rather than the absence of dystrophin. In the present study, we examined whether the nerve terminal determines the fate of acetylcholine receptor distribution in the dystrophic muscle fibers of mdx mice. The left sternomastoid muscle of young (1-month-old) and adult (6-month-old) mdx mice was injected with 60 microl lidocaine hydrochloride to induce muscle degeneration-regeneration. Some mice had their sternomastoid muscle denervated at the time of lidocaine injection. After 10 days of muscle denervation, nerve terminals and acetylcholine receptors were labeled with 4-Di-2-ASP and rhodamine-alpha-bungarotoxin, respectively, for confocal microscopy. In young mdx mice, 75% (n = 137 endplates) of the receptors were distributed in islands. The same was observed in 100% (n = 114 endplates) of the adult junctions. In denervated-regenerated fibers of young mice, the receptors were distributed as branches in 89% of the endplates (n = 90). In denervated-regenerated fibers of adult mice, the receptors were distributed in islands in 100% of the endplates (n = 100). These findings show that nerve-dependent mechanisms are also involved in the changes in receptor distribution in young dystrophic muscles. In older dystrophic muscles, other factors may play a role in receptor distribution.

The Pixel-TPC. Demonstration of the concept and results

Energy Technology Data Exchange (ETDEWEB)

Lupberger, Michael [Universitaet Bonn (Germany); Collaboration: LCTPC-Deutschland-Collaboration

2016-07-01

A Time Projection Chamber (TPC) is foreseen as tracker for the ILD, one of the two detector concepts at the planned International Linear Collider (ILC). At the TPC endplates, Micromegas or GEMs will be used as gas amplification structure. Besides segmented anodes, also an active endplate with pixel chips, in our experiments the Timepix ASIC, is considered as a readout option. In a photolithographic process a grid has been produced on top of the chip to form a so called InGrid, which is a Micromegas-like gas amplification structure. Several thousand InGrids are necessary to equip a complete TPC endplate. For demonstration of the concept, three endplate modules have been built with a total of 160 InGrids covering an active area of about 300 cm{sup 2}. To read out the 10.5 million channels, the Timepix ASIC was implemented in a general readout system. A dedicated powering scheme, DAQ and online event display were developed by our group. The feasibility of the Pixel-TPC could be proven in a test beam campaign at DESY early 2015. The data has partly been analysed and shows the potential of this new type of detector. An overview of the developments necessary to build the detector is presented followed by impressions from the test beam and some of the results from the data analysis.

Retroactive signaling in short signaling pathways.

Directory of Open Access Journals (Sweden)

Jacques-Alexandre Sepulchre

Full Text Available In biochemical signaling pathways without explicit feedback connections, the core signal transduction is usually described as a one-way communication, going from upstream to downstream in a feedforward chain or network of covalent modification cycles. In this paper we explore the possibility of a new type of signaling called retroactive signaling, offered by the recently demonstrated property of retroactivity in signaling cascades. The possibility of retroactive signaling is analysed in the simplest case of the stationary states of a bicyclic cascade of signaling cycles. In this case, we work out the conditions for which variables of the upstream cycle are affected by a change of the total amount of protein in the downstream cycle, or by a variation of the phosphatase deactivating the same protein. Particularly, we predict the characteristic ranges of the downstream protein, or of the downstream phosphatase, for which a retroactive effect can be observed on the upstream cycle variables. Next, we extend the possibility of retroactive signaling in short but nonlinear signaling pathways involving a few covalent modification cycles.

Slotted cage resonator for high-field magnetic resonance imaging of rodents

Energy Technology Data Exchange (ETDEWEB)

Marrufo, O; Vasquez, F; Solis, S E; Rodriguez, A O, E-mail: arog@xanum.uam.mx [Departamento de Ingenieria Electrica, Universidad Autonoma Metropolitana Iztapalapa, Mexico, DF 09340 (Mexico)

2011-04-20

A variation of the high-frequency cavity resonator coil was experimentally developed according to the theoretical frame proposed by Mansfield in 1990. Circular slots were used instead of cavities to form the coil endplates and it was called the slotted cage resonator coil. The theoretical principles were validated via a coil equivalent circuit and also experimentally with a coil prototype. The radio frequency magnetic field, B1, produced by several coil configurations was numerically simulated using the finite-element approach to investigate their performances. A transceiver coil, 8 cm long and 7.6 cm in diameter, and composed of 4 circular slots with a 15 mm diameter on both endplates, was built to operate at 300 MHz and quadrature driven. Experimental results obtained with the slotted cage resonator coil were presented and showed very good agreement with the theoretical expectations for the resonant frequency as a function of the coil dimensions and slots. A standard birdcage coil was also built for performance comparison purposes. Phantom images were then acquired to compute the signal-to-noise ratio of both coils showing an important improvement of the slotted cage coil over the birdcage coil. The whole-body images of the mouse were also obtained showing high-quality images. Volume resonator coils can be reliably built following the physical principles of the cavity resonator design for high-field magnetic resonance imaging applications of rodents.

Development of a new bundle welding technology for CANDU fuels

International Nuclear Information System (INIS)

Kim, Soo Sung; Lee, D. Y.; Goo, D. S.

2010-01-01

The new technology of welding process for fuel bundle of CANDU nuclear fuels is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of leakage of the fission products is mostly apt to occur at the weldments of fuel bundles, and it is connected directly with the safety and life prediction of the nuclear reactor in operation. The fuel bundles of CANDU nuclear fuels are welded by the electrical resistance method, connecting the endplates and endcaps with fuel rods. Therefore, the purpose of this study of the 2nd year is to select the proper welding parameters and to investigate the characteristics of the full-sized samples using the projection endplates and make some prototype samples for the endplate welding of CANDU nuclear fuels. This study will be also provide the fundamental data for the new design and fabrications of CANDU nuclear fuel bundles

Collagen-derived N-acetylated proline-glycine-proline upregulates the expression of pro-inflammatory cytokines and extracellular matrix proteases in nucleus pulposus cells via the NF-κB and MAPK signaling pathways.

Science.gov (United States)

Feng, Chencheng; He, Jinyue; Zhang, Yang; Lan, Minghong; Yang, Minghui; Liu, Huan; Huang, Bo; Pan, Yong; Zhou, Yue

2017-07-01

N-acetylated proline-glycine-proline (N-Ac-PGP) is a chemokine involved in inflammatory diseases and is found to accumulate in degenerative discs. N-Ac-PGP has been demonstrated to have a pro-inflammatory effect on human cartilage endplate stem cells. However, the effect of N-Ac-PGP on human intervertebral disc cells, especially nucleus pulposus (NP) cells, remains unknown. The purpose of this study was to investigate the effect of N-Ac-PGP on the expression of pro-inflammatory factors and extracellular matrix (ECM) proteases in NP cells and the molecular mechanism underlying this effect. Therefore, Milliplex assays were used to detect the levels of various inflammatory cytokines in conditioned culture medium of NP cells treated with N-Ac-PGP, including interleukin-1β (IL-1β), IL-6, IL-17, tumor necrosis factor-α (TNF-α) and C-C motif ligand 2 (CCL2). RT-qPCR was also used to determine the expression of pro-inflammatory cytokines and ECM proteases in the NP cells treated with N-Ac-PGP. Moreover, the role of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways in mediating the effect of N-Ac-PGP on the phenotype of NP cells was investigated using specific signaling inhibitors. Milliplex assays showed that NP cells treated with N-Ac-PGP (10 and 100 µg/ml) secreted higher levels of IL-1β, IL-6, IL-17, TNF-α and CCL2 compared with the control. RT-qPCR assays showed that NP cells treated with N-Ac-PGP (100 µg/ml) had markedly upregulated expression of matrix metalloproteinase 3 (MMP3), MMP13, a disintegrin and metalloproteinase with thrombospondin motif 4 (ADAMTS4), ADAMTS5, IL-6, CCL-2, CCL-5 and C-X-C motif chemokine ligand 10 (CXCL10). Moreover, N-Ac-PGP was shown to activate the MAPK and NF-κB signaling pathways in NP cells. MAPK and NF-κB signaling inhibitors suppressed the upregulation of proteases and pro-inflammatory cytokines in NP cells treated with N-Ac-PGP. In conclusion, N-Ac-PGP induces the

PET imaging in patients with Modic changes

DEFF Research Database (Denmark)

Albert, Hanne; Pedersen, Henrik; Manniche, Claus

2009-01-01

associated with low back pain (LBP). MC type 1 appear to be inflammation on MRI, and histological and biochemical findings make it highly likely that an inflammation is present. Though MC is painful no known treatment is available, and it is unknown which entities affect the progress or regress of MC....... The changes observed on MRI are slow and take months to develop, but faster changes in the metabolism might provide a platform for monitoring patients. PATIENTS, METHODS: Patients from The Back Centre Funen, with low back pain in the area of L1 to S1, MC type 1 in L1 to L5, and a previous herniated lumbar...... disc. All patients had a PET scan using FDG (18F-fluorodeoxyglucose) as tracer. RESULTS: Included in the study were 11 patients, 4 women and 7 men, mean age 48.1 year (range 20-65). All MC were situated in the vertebrae both above and below the previously herniated disc/discs. Ten patients had MC at 1...

Height gain of vertebral bodies and stabilization of vertebral geometry over one year after vertebroplasty of osteoporotic vertebral fractures

International Nuclear Information System (INIS)

Pitton, Michael B.; Morgen, Nadine; Herber, Sascha; Dueber, Christoph; Drees, Philipp; Boehm, Bertram

2008-01-01

The height gain of vertebral bodies after vertebroplasty and geometrical stability was evaluated over a one-year period. Osteoporotic fractures were treated with vertebroplasty. The vertebral geometry and disc spaces were analysed using reformatted computed tomography (CT) images: heights of the anterior, posterior, and lateral vertebral walls, disc spaces, endplate angles, and minimal endplate distances. Vertebrae were assigned to group I [severe compression (anterior height/posterior height) 0.75). A total of 102 vertebral bodies in 40 patients (12 men, 28 women, age 70.3 ± 9.5) were treated with vertebroplasty and prospectively followed for 12 months. Group I showed a greater benefit compared with group II with respect to anterior height gain (+2.1 ± 1.9 vs +0.7 ± 1.6 mm, P < 0.001), reduction of endplate angle (-3.6 ± 4.2 vs -0.8 ± 2.3 , P < 0.001), and compression index (+0.09 ± 0.11 vs +0.01 ± 0.06, P < 0.001). At one-year follow-up, group I demonstrated preserved anterior height gain (+1.5 ± 2.8 mm, P < 0.015) and improved endplate angle (-3.4 ± 4.9 , P < 0.001). In group II, the vertebral heights returned to and were fixed at the pre-interventional levels. Vertebroplasty provided vertebral height gain over one year, particularly in cases with severe compression. Vertebrae with moderate compression were fixed and stabilized at the pre-treatment level over one year. (orig.)

Variable reflectivity signal mirrors and signal response measurements

International Nuclear Information System (INIS)

Vine, Glenn de; Shaddock, Daniel A; McClelland, David E

2002-01-01

Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations

Variable reflectivity signal mirrors and signal response measurements

CERN Document Server

Vine, G D; McClelland, D E

2002-01-01

Future gravitational wave detectors will include some form of signal mirror in order to alter the signal response of the device. We introduce interferometer configurations which utilize a variable reflectivity signal mirror allowing a tunable peak frequency and variable signal bandwidth. A detector configured with a Fabry-Perot cavity as the signal mirror is compared theoretically with one using a Michelson interferometer for a signal mirror. A system for the measurement of the interferometer signal responses is introduced. This technique is applied to a power-recycled Michelson interferometer with resonant sideband extraction. We present broadband measurements of the benchtop prototype's signal response for a range of signal cavity detunings. This technique is also applicable to most other gravitational wave detector configurations.

The Low Energy Antiproton Ring (LEAR) in its first year of operation

CERN Multimedia

1983-01-01

LEAR*) and its enclosure in the PS South Hall in 1983 shortly after the start of its particle physics programme. Visible (in red) are the 90 degree bending magnets consisting of 6 blocks each. Separated from the magnets by short straight sections are the quadrupole doublets (blue with read end-plates). The 4 long straight sections house large equipment like septa for injection/ejection, RF-cavities and later (since 1986) electron cooling and an internal target and its associated detector (JETSET experiment). Several small copper tubes spanning across the ring are coaxial lines transmitting the stochastic cooling signals from pickup to kicker. *)[see H.Koziol and D. Möhl, Phys. Rep. 403-404 (2004), p.271 and references therein

Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

Science.gov (United States)

Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

2013-12-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

Signaling aggression.

Science.gov (United States)

van Staaden, Moira J; Searcy, William A; Hanlon, Roger T

2011-01-01

From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. Certain animal signals are strongly associated with escalation toward attack and have the same function as physical attack in intimidating opponents and winning contests, and ethologists therefore consider them an integral part of aggressive behavior. Aggressive signals have been molded by evolution to make them ever more effective in mediating interactions between the contestants. Early theoretical analyses of aggressive signaling suggested that signals could never be honest about fighting ability or aggressive intentions because weak individuals would exaggerate such signals whenever they were effective in influencing the behavior of opponents. More recent game theory models, however, demonstrate that given the right costs and constraints, aggressive signals are both reliable about strength and intentions and effective in influencing contest outcomes. Here, we review the role of signaling in lieu of physical violence, considering threat displays from an ethological perspective as an adaptive outcome of evolutionary selection pressures. Fighting prowess is conveyed by performance signals whose production is constrained by physical ability and thus limited to just some individuals, whereas aggressive intent is encoded in strategic signals that all signalers are able to produce. We illustrate recent advances in the study of aggressive signaling with case studies of charismatic taxa that employ a range of sensory modalities, viz. visual and chemical signaling in cephalopod behavior, and indicators of aggressive intent in the territorial calls of songbirds. Copyright © 2011 Elsevier Inc. All rights reserved.

Robust power detector for wideband signals among many single tone signals

Science.gov (United States)

Musgrove, Cameron H.; Thompson, Douglas

2018-03-06

Various technologies for isolating a signal of interest from signals received contemporaneously by an antenna are described herein. A time period for which a signal of interest is present in a second signal can be identified based upon ratios of values of the second signal to the mean value of the second signal. When the ratio of the value of the second signal at a particular time to the mean of the second signal exceeds a threshold value, the signal of interest is considered to be present in the second signal.

Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling.

Science.gov (United States)

Xu, Enjun; Brosché, Mikael

2014-06-04

Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling.

Evaluation of effects of selected factors on inter-vertebral fusion-a simulation study.

Science.gov (United States)

Wang, Xiaobo; Dumas, Geneviève A

2005-04-01

This study simulated the effects of inter-vertebral disc degeneration and bone density distribution on the structural stiffness and strength provided by inter-vertebral fusion. Based on the original and redistributed bone density distributions, the effects of selected factors, including contact area between device/graft and vertebral endplates, endplate conditions, and bone growth capacity were evaluated using a factorial design of experiment. The simulation results suggested that the degeneration of inter-vertebral disc significantly affected the bone density and density distribution in adjacent vertebrae. The mechanical strength immediately after instrumentation is the worst case of device/graft subsidence. After that procedure, bone will adapt itself to the changed loading conditions and therefore reduce the risk of subsidence. A deficiency in structural stiffness immediately after instrumentation could be the "worst-case scenario" depending on the combinations of selected factors. The simulation results demonstrated that the contact area and initial bone density distribution should be considered jointly while estimating the risk of device/graft subsidence. The endplate condition is a secondary factor on the subsidence risk, compared with the contact area and initial bone density distribution.

[Utility of nickel-titanium shape memory alloys of vertebral body reduction fixator with assisted distraction bar].

Science.gov (United States)

Man, Yi; Zheng, Yue-huan; Cao, Peng; Chen, Bo; Zheng, Tao; Sun, Chang-hui; Lu, Jiong

2011-06-07

To test the nickel-titanium (Ni-Ti) shape memory alloys of vertebral body reduction fixator with assisted distraction bar for the treatment of traumatic and osteoporotic vertebral body fracture. A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar was implanted into the compressed fracture specimens through vertebral pedicle with the radiographic monitoring to reduce the collapsed endplate as well as distract the compressed vertebral fracture. Radiographic film and computed tomographic reconstruction technique were employed to evaluate the effects of reduction and distraction. A biomechanic test machine was used to measure the fatigue and the stability of deformation of fixation segments. Relying on the effect of temperature shape memory, such an assembly could basically reduce the collapsed endplate as well as distract the compressed vertebral fracture. And when unsatisfied results of reduction and distraction occurred, its super flexibility could provide additional distraction strength. A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar may provide effective endplate reduction, restore the vertebral height and the immediate biomechanic spinal stability. So the above assembly is indicated for the treatment of traumatic and osteoporotic vertebral body fracture.

Optimal Signal Quality Index for Photoplethysmogram Signals

Directory of Open Access Journals (Sweden)

Mohamed Elgendi

2016-09-01

Full Text Available A photoplethysmogram (PPG is a noninvasive circulatory signal related to the pulsatile volume of blood in tissue and is typically collected by pulse oximeters. PPG signals collected via mobile devices are prone to artifacts that negatively impact measurement accuracy, which can lead to a significant number of misleading diagnoses. Given the rapidly increased use of mobile devices to collect PPG signals, developing an optimal signal quality index (SQI is essential to classify the signal quality from these devices. Eight SQIs were developed and tested based on: perfusion, kurtosis, skewness, relative power, non-stationarity, zero crossing, entropy, and the matching of systolic wave detectors. Two independent annotators annotated all PPG data (106 recordings, 60 s each and a third expert conducted the adjudication of differences. The independent annotators labeled each PPG signal with one of the following labels: excellent, acceptable or unfit for diagnosis. All indices were compared using Mahalanobis distance, linear discriminant analysis, quadratic discriminant analysis, and support vector machine with leave-one-out cross-validation. The skewness index outperformed the other seven indices in differentiating between excellent PPG and acceptable, acceptable combined with unfit, and unfit recordings, with overall F 1 scores of 86.0%, 87.2%, and 79.1%, respectively.

Optimal Signal Quality Index for Photoplethysmogram Signals.

Science.gov (United States)

Elgendi, Mohamed

2016-09-22

A photoplethysmogram (PPG) is a noninvasive circulatory signal related to the pulsatile volume of blood in tissue and is typically collected by pulse oximeters. PPG signals collected via mobile devices are prone to artifacts that negatively impact measurement accuracy, which can lead to a significant number of misleading diagnoses. Given the rapidly increased use of mobile devices to collect PPG signals, developing an optimal signal quality index (SQI) is essential to classify the signal quality from these devices. Eight SQIs were developed and tested based on: perfusion, kurtosis, skewness, relative power, non-stationarity, zero crossing, entropy, and the matching of systolic wave detectors. Two independent annotators annotated all PPG data (106 recordings, 60 s each) and a third expert conducted the adjudication of differences. The independent annotators labeled each PPG signal with one of the following labels: excellent, acceptable or unfit for diagnosis. All indices were compared using Mahalanobis distance, linear discriminant analysis, quadratic discriminant analysis, and support vector machine with leave-one-out cross-validation. The skewness index outperformed the other seven indices in differentiating between excellent PPG and acceptable, acceptable combined with unfit, and unfit recordings, with overall F 1 scores of 86.0%, 87.2%, and 79.1%, respectively.

Signal Words

Science.gov (United States)

SIGNAL WORDS TOPIC FACT SHEET NPIC fact sheets are designed to answer questions that are commonly asked by the ... making decisions about pesticide use. What are Signal Words? Signal words are found on pesticide product labels, ...

Relationship between complement activation, cellular uptake and surface physicochemical aspects of novel PEG-modifed nanocapsules.

OpenAIRE

Mosqueira, Vanessa Carla Furtado; Legrand, Philippe; Gulik, Annette; Bourdon, Olivier; Gref, Ruxandra; Labarre, Denis; Barratt, Gillian

2001-01-01

ABSTRACT: The aim of our work was to examine the relationship between modi"cations of the surface of nanocapsules (NC) by adsorption or covalent grafting of poly(ethylene oxide) (PEG), and changes in their phospholipid (PL) content on complement activation (C3 cleavage) and on uptake by macrophages. The physicochemical characterization of the NC included an investigation of their properties, such as surface charge, size, hydrophilicity, morphology and homogeneity. This is the "rst ti...

Detection of Noise in Composite Step Signal Pattern by Visualizing Signal Waveforms

Directory of Open Access Journals (Sweden)

Chaman Verma

2018-03-01

Full Text Available The Step Composite Signals is the combination of vital informative signals that are compressed and coded to produce a predefined test image on a display device. It carries the desired sequence of information from source to destination. This information may be transmitted as digital signal, video information or data signal required as an input for the destination module. For testing of display panels, Composite Test Signals are the most important attribute of test signal transmission system. In the current research paper we present an approach for the noise detection in Composite Step Signal by analysing Composite Step Signal waveforms. The analysis of the signal waveforms reveals that the noise affected components of the signal and subsequently noise reduction process is initiated which targets noisy signal component only. Thus the quality of signal is not compromised during noise reduction process.

Multimodal signal variation in space and time : how important is matching a signal with its signaler?

OpenAIRE

Taylor, Ryan C.; Klein, Barrett; Stein, Joey; Ryan, Michael J.

2011-01-01

Multimodal signals (acoustic+visual) are known to be used by many anuran amphibians during courtship displays. The relative degree to which each signal component influences female mate choice, however, remains poorly understood. In this study we used a robotic frog with an inflating vocal sac and acoustic playbacks to document responses of female túngara frogs to unimodal signal components (acoustic and visual). We then tested female responses to a synchronous multimodal signal. Finally, we t...

Finite element study of a lumbar intervertebral disc nucleus replacement device

Directory of Open Access Journals (Sweden)

Jessica S Coogan

2016-12-01

Full Text Available Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3-L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3-L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics

Quantification of Propionic Acid in the Bovine Spinal Disk After Infection of the Tissue With Propionibacteria acnes Bacteria.

Science.gov (United States)

Magnitsky, Sergey; Dudli, Stefan; Tang, Xinyan; Kaur, Jaskanwaljeet; Diaz, Joycelyn; Miller, Steve; Lotz, Jeffrey C

2018-06-01

Research. The goal of this study was to investigate whether Propionibacteria acnes infection of the intervertebral disc can be detected noninvasively by nuclear magnetic resonance (NMR) spectroscopy. Microbiological studies of surgical samples suggest that a significant subpopulation of back pain patients may have occult disc infection with P. acnes bacteria. This hypothesis is further supported by a double-blind clinical trial showing that back pain patients with Modic type 1 changes may respond to antibiotic treatment. Because significant side effects are associated with antibiotic treatment, there is a need for a noninvasive method to detect whether specific discs in back pain patients are infected with P acnes bacteria. P. acnes bacteria were obtained from human patients. NMR detection of a propionic acid (PA) in the bacteria extracts was conducted on 500 MHz high-resolution spectrometer, whereas in vivo NMR spectroscopy of an isolated bovine disk tissue infected with P. acnes was conducted on 7 T magnetic resonance imaging scanner. NMR spectra of P. acnes metabolites revealed a distinct NMR signal with identical chemical shits (1.05 and 2.18 ppm) as PA (a primary P. acne metabolite). The 1.05 ppm signal does not overlap with other bacteria metabolites, and its intensity increases linearly with P. acnes concentration. Bovine disks injected with P. acnes bacteria revealed a very distinct NMR signal at 1.05 ppm, which linearly increased with P. acnes concentration. The 1.05 ppm NMR signal from PA can be used as a marker of P. acnes infection of discs. This signal does not overlap with other disc metabolites and linearly depends on P. acnes concentration. Consequently, NMR spectroscopy may provide a noninvasive method to detect disc infection in the clinical setting. N/A.

Signal detection

International Nuclear Information System (INIS)

Tholomier, M.

1985-01-01

In a scanning electron microscope, whatever is the measured signal, the same set is found: incident beam, sample, signal detection, signal amplification. The resulting signal is used to control the spot luminosity with the observer cathodoscope. This is synchronized with the beam scanning on the sample; on the cathodoscope, the image in secondary electrons, backscattered electrons,... of the sample surface is reconstituted. The best compromise must be found between a register time low enough to remove eventual variations (under the incident beam) of the nature of the observed phenomenon, and a good spatial resolution of the image and a signal-to-noise ratio high enough. The noise is one of the basic limitations of the scanning electron microscope performance. The whose measurement line must be optimized to reduce it [fr

The Low Energy Antiproton Ring (LEAR) some months before the start of its particle physics programme

CERN Multimedia

1983-01-01

LEAR*)and its enclosure in the PS South Hall in Jan, 1983, 4 months before the start of its particle physics programme. Visible (in red) are the 90 degree bending magnets consisting of 6 blocks each. Separated from the magnets by short straight sections are the quadrupole doublets (blue with read end-plates). The 4 long straight sections house large equipment like septa for injection/ejection, RF-cavities and later (since 1986) electron cooling and an internal target and its associated detector (JETSET experiment). Two small copper tubes spanning across the ring are coaxial lines transmitting the stochastic cooling signals from pickup to kicker. (see also photos 8205747X, 8207133, 8207541X, 8309026) *)see e.g.: H.Koziol and D. Möhl, Phys. Rep. 403-404 (2004), p.271 and references therein

Quebec Back Pain Disability Scale, Low Back Outcome Score and revised Oswestry low back pain disability scale for patients with low back pain due to degenerative disc disease: evaluation of Polish versions.

Science.gov (United States)

Misterska, Ewa; Jankowski, Roman; Glowacki, Maciej

2011-12-15

Evaluation and comparison of translated and culturally adapted self-reported measurements. The aim of this prospective study was to cross-culturally adapt the Polish versions of Revised Oswestry Disability Index (RODI-PL), Quebec Back Pain Disability Scale (QDS-PL), and the Low Back Outcome Score (LBOS-PL). The application of instruments in English, which have undergone translation must be subjected to validation studies. Such studies are necessary above all for instruments that have been adapted to establish their value and usefulness in studies of patient populations where English is not the native language. The translation was carried out according to International Quality of Life Association (IQOLA) Project and consisted of the following stages: translation, synthesis of the translations, back translation, expert committee, and testing of the prefinal versions of questionnaires. Eighty-five consecutive patients with low back pain due to spinal disc herniation and degenerative changes completed the QDS-PL, RODI-PL, LBOS-PL, and a Visual Analogue Scale twice within 2-day intervals. Mean duration of LBP was 45.9 months SD 55.5. The evaluation of degenerative changes in the lumbar region was carried out according to the Modic scale. Twenty-nine patients were categorized at type I, 4 patients were registered as type II, and 52 patients were type III. Cronbach α values for the LBOS-PL equaled 0.77, for the RODI-PL 0.85, and 0.95 for the QDS-PL. Item-total correlation confirmed that all scales are internally consistent. Test-retest reliability was excellent for RODI-PL and QDS-PL, but poor for LBOS-PL (0.88, 0.93, and 0.34, respectively). All questionnaires were significantly intercorrelated. We identified the strongest correlation between QDS-PL and RODI-PL (0.823, P < 0.001). The statistically significant correlation was identified between the QDS-PL and Modic Classification (rS = 0.226 P = 0.038). QBPDS-PL and RODI-PL are reliable and valid. Furthermore

Digital signal processing the Tevatron BPM signals

International Nuclear Information System (INIS)

Cancelo, G.; James, E.; Wolbers, S.

2005-01-01

The Beam Position Monitor (TeV BPM) readout system at Fermilab's Tevatron has been updated and is currently being commissioned. The new BPMs use new analog and digital hardware to achieve better beam position measurement resolution. The new system reads signals from both ends of the existing directional stripline pickups to provide simultaneous proton and antiproton measurements. The signals provided by the two ends of the BPM pickups are processed by analog band-pass filters and sampled by 14-bit ADCs at 74.3MHz. A crucial part of this work has been the design of digital filters that process the signal. This paper describes the digital processing and estimation techniques used to optimize the beam position measurement. The BPM electronics must operate in narrow-band and wide-band modes to enable measurements of closed-orbit and turn-by-turn positions. The filtering and timing conditions of the signals are tuned accordingly for the operational modes. The analysis and the optimized result for each mode are presented

Transient-Switch-Signal Suppressor

Science.gov (United States)

Bozeman, Richard J., Jr.

1995-01-01

Circuit delays transmission of switch-opening or switch-closing signal until after preset suppression time. Used to prevent transmission of undesired momentary switch signal. Basic mode of operation simple. Beginning of switch signal initiates timing sequence. If switch signal persists after preset suppression time, circuit transmits switch signal to external circuitry. If switch signal no longer present after suppression time, switch signal deemed transient, and circuit does not pass signal on to external circuitry, as though no transient switch signal. Suppression time preset at value large enough to allow for damping of underlying pressure wave or other mechanical transient.

Fast digitizing and digital signal processing of detector signals

International Nuclear Information System (INIS)

Hannaske, Roland

2008-01-01

A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22 Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing. (orig.)

Second-hand signals

DEFF Research Database (Denmark)

Bergenholtz, Carsten

2014-01-01

Studies of signaling theory have traditionally focused on the dyadic link between the sender and receiver of the signal. Within a science‐based perspective this framing has led scholars to investigate how patents and publications of firms function as signals. I explore another important type...... used by various agents in their search for and assessment of products and firms. I conclude by arguing how this second‐hand nature of signals goes beyond a simple dyadic focus on senders and receivers of signals, and thus elucidates the more complex interrelations of the various types of agents...

Signal-BNF: A Bayesian Network Fusing Approach to Predict Signal Peptides

Directory of Open Access Journals (Sweden)

Zhi Zheng

2012-01-01

Full Text Available A signal peptide is a short peptide chain that directs the transport of a protein and has become the crucial vehicle in finding new drugs or reprogramming cells for gene therapy. As the avalanche of new protein sequences generated in the postgenomic era, the challenge of identifying new signal sequences has become even more urgent and critical in biomedical engineering. In this paper, we propose a novel predictor called Signal-BNF to predict the N-terminal signal peptide as well as its cleavage site based on Bayesian reasoning network. Signal-BNF is formed by fusing the results of different Bayesian classifiers which used different feature datasets as its input through weighted voting system. Experiment results show that Signal-BNF is superior to the popular online predictors such as Signal-3L and PrediSi. Signal-BNF is featured by high prediction accuracy that may serve as a useful tool for further investigating many unclear details regarding the molecular mechanism of the zip code protein-sorting system in cells.

SignalPlant: an open signal processing software platform.

Science.gov (United States)

Plesinger, F; Jurco, J; Halamek, J; Jurak, P

2016-07-01

The growing technical standard of acquisition systems allows the acquisition of large records, often reaching gigabytes or more in size as is the case with whole-day electroencephalograph (EEG) recordings, for example. Although current 64-bit software for signal processing is able to process (e.g. filter, analyze, etc) such data, visual inspection and labeling will probably suffer from rather long latency during the rendering of large portions of recorded signals. For this reason, we have developed SignalPlant-a stand-alone application for signal inspection, labeling and processing. The main motivation was to supply investigators with a tool allowing fast and interactive work with large multichannel records produced by EEG, electrocardiograph and similar devices. The rendering latency was compared with EEGLAB and proves significantly faster when displaying an image from a large number of samples (e.g. 163-times faster for 75  ×  10(6) samples). The presented SignalPlant software is available free and does not depend on any other computation software. Furthermore, it can be extended with plugins by third parties ensuring its adaptability to future research tasks and new data formats.

Tunable Signal-Off and Signal-On Electrochemical Cisplatin Sensor.

Science.gov (United States)

Wu, Yao; Lai, Rebecca Y

2017-09-19

We report the first electrochemical cisplatin sensor fabricated with a thiolated and methylene blue (MB)-modified oligo-adenine (A)-guanine (G) DNA probe. Depending on the probe coverage, the sensor can behave as a signal-off or signal-on sensor. For the high-coverage sensor, formation of intrastrand Pt(II)-AG adducts rigidifies the oligo-AG probe, resulting in a concentration-dependent decrease in the MB signal. For the low-coverage sensor, the increase in probe-to-probe spacing enables binding of cisplatin via the intrastrand GNG motif (N = A), generating a bend in the probe which results in an increase in the MB current. Although both high-coverage signal-off and low-coverage signal-on sensors are capable of detecting cisplatin, the signal-on sensing mechanism is better suited for real time analysis of cisplatin. The low-coverage sensor has a lower limit of detection, wider optimal AC frequency range, and faster response time. It has high specificity for cisplatin and potentially other Pt(II) drugs and does not cross-react with satraplatin, a Pt(IV) prodrug. It is also selective enough to be employed directly in 50% saliva and 50% urine. This detection strategy may offer a new approach for sensitive and real time analysis of cisplatin in clinical samples.

Signal sciences workshop proceedings

Energy Technology Data Exchange (ETDEWEB)

Candy, J.V.

1997-05-01

This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing.

Signal sciences workshop. Proceedings

International Nuclear Information System (INIS)

Candy, J.V.

1997-01-01

This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing

Orexin/Hypocretin Signaling.

Science.gov (United States)

Kukkonen, Jyrki P

Orexin/hypocretin peptide (orexin-A and orexin-B) signaling is believed to take place via the two G-protein-coupled receptors (GPCRs), named OX 1 and OX 2 orexin receptors, as described in the previous chapters. Signaling of orexin peptides has been investigated in diverse endogenously orexin receptor-expressing cells - mainly neurons but also other types of cells - and in recombinant cells expressing the receptors in a heterologous manner. Findings in the different systems are partially convergent but also indicate cellular background-specific signaling. The general picture suggests an inherently high degree of diversity in orexin receptor signaling.In the current chapter, I present orexin signaling on the cellular and molecular levels. Discussion of the connection to (potential) physiological orexin responses is only brief since these are in focus of other chapters in this book. The same goes for the post-synaptic signaling mechanisms, which are dealt with in Burdakov: Postsynaptic actions of orexin. The current chapter is organized according to the tissue type, starting from the central nervous system. Finally, receptor signaling pathways are discussed across tissues, cell types, and even species.

Effects of X-irradiation on axonal sprouting induced by botulinum toxin

Energy Technology Data Exchange (ETDEWEB)

Gomez, S; Duchen, L W [National Hospital, London (UK); Hornsey, S [Hammersmith Hospital, London (UK). M.R.C. Cyclotron Unit

1982-01-01

The effect of X-irradiation on axonal sprouting of motor nerves induced by botulinum toxin was examined. Muscles of one leg in the mouse were X-irradiated (15Gy) prior to the injection of a locally paralysing dose of botulinum toxin. It was found that axonal sprouting occurred as expected, but the sprouts remained unmyelinated and many degenerated. Fewer new end-plates were formed, muscles remained more severely atrophied and supersensitive to acetylcholine and recovery of neuromuscular transmission was greatly delayed when compared with the effects of botulinum toxin alone. X-irradiation did not prevent sprouting but, probably by impairing Schwann cell proliferation, altered axon-Schwann cell relationships and prevented the maturation of newly-formed axons and the differentiation of new end-plates.

Spectral Correlation of Multicarrier Modulated Signals and Its Application for Signal Detection

Directory of Open Access Journals (Sweden)

Zhang Haijian

2010-01-01

Full Text Available Spectral correlation theory for cyclostationary time-series signals has been studied for decades. Explicit formulas of spectral correlation function for various types of analog-modulated and digital-modulated signals are already derived. In this paper, we investigate and exploit the cyclostationarity characteristics for two kinds of multicarrier modulated (MCM signals: conventional OFDM and filter bank based multicarrier (FBMC signals. The spectral correlation characterization of MCM signal can be described by a special linear periodic time-variant (LPTV system. Using this LPTV description, we have derived the explicit theoretical formulas of nonconjugate and conjugate cyclic autocorrelation function (CAF and spectral correlation function (SCF for OFDM and FBMC signals. According to theoretical spectral analysis, Cyclostationary Signatures (CS are artificially embedded into MCM signal and a low-complexity signature detector is, therefore, presented for detecting MCM signal. Theoretical analysis and simulation results demonstrate the efficiency and robustness of this CS detector compared to traditionary energy detector.

ATP signals

DEFF Research Database (Denmark)

Novak, Ivana

2016-01-01

The Department of Biology at the University of Copenhagen explains the function of ATP signalling in the pancreas......The Department of Biology at the University of Copenhagen explains the function of ATP signalling in the pancreas...

Basic digital signal processing

CERN Document Server

Lockhart, Gordon B

1985-01-01

Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

ECG signal processing

NARCIS (Netherlands)

2009-01-01

A system extracts an ECG signal from a composite signal (308) representing an electric measurement of a living subject. Identification means (304) identify a plurality of temporal segments (309) of the composite signal corresponding to a plurality of predetermined segments (202,204,206) of an ECG

Nichtkontinuierliche (zeitdiskrete) Signale

Science.gov (United States)

Plaßmann, Wilfried

Zeitdiskrete Signale werden häufig aus zeitkontinuierlichen Signalen durch Abtastung erzeugt. Dass beide Signale gleichwertig sind, zeigt das Abtasttheorem (Kap. 116) von Shannon, sofern die Bedingung nach (116.2), f_{ab}≈(2{,}2 {\\ldots} 4)\\cdot fg) eingehalten wird. Digitale Signale haben Vorteile: Einfache Speicherung, Weiterverarbeitung in Rechnern, wenig störanfällige Übertragung. Für die Bearbeitung dieser Signale dienen die im Kapitel dargestellten Hilfsmittel: Diskrete Fouriertransformation; Schnelle Fouriertransformation; z-Transformation: Darstellung, Sätze zur z-Transformation, Korrespondenzen zu Zeitfunktionen, Beispiele.

Digital signal processing

CERN Document Server

O'Shea, Peter; Hussain, Zahir M

2011-01-01

In three parts, this book contributes to the advancement of engineering education and that serves as a general reference on digital signal processing. Part I presents the basics of analog and digital signals and systems in the time and frequency domain. It covers the core topics: convolution, transforms, filters, and random signal analysis. It also treats important applications including signal detection in noise, radar range estimation for airborne targets, binary communication systems, channel estimation, banking and financial applications, and audio effects production. Part II considers sel

Silicon Photonics for Signal Processing of Tbit/s Serial Data Signals

DEFF Research Database (Denmark)

Oxenløwe, Leif Katsuo; Ji, Hua; Galili, Michael

2012-01-01

In this paper, we describe our recent work on signal processing of terabit per second optical serial data signals using pure silicon waveguides. We employ nonlinear optical signal processing in nanoengineered silicon waveguides to perform demultiplexing and optical waveform sampling of 1.28-Tbit/...

Muon Signals at a Low Signal-to-Noise Ratio Environment

CERN Document Server

Zakareishvili, Tamar; The ATLAS collaboration

2017-01-01

Calorimeters provide high-resolution energy measurements for particle detection. Muon signals are important for evaluating electronics performance, since they produce a signal that is close to electronic noise values. This work provides a noise RMS analysis for the Demonstrator drawer of the 2016 Tile Calorimeter (TileCal) Test Beam in order to help reconstruct events in a low signal-to-noise environment. Muon signals were then found for a beam penetrating through all three layers of the drawer. The Demonstrator drawer is an electronic candidate for TileCal, part of the ATLAS experiment for the Large Hadron Collider that operates at the European Organization for Nuclear Research (CERN).

The Low Energy Antiproton Ring (LEAR) some months before the start of its particle physics programme

CERN Multimedia

1983-01-01

LEAR [see e.g.: H.Koziol and D. Möhl, Phys. Rep. 403-404 (2004), p.271 and references therein] and its enclosure in the PS South Hall in Jan, 1983, 4 months before the start of its particle physics programme. Visible (in red) are the 90 degree bending magnets consisting of 6 blocks each. Separated from the magnets by short straight sections are the quadrupole doublets (blue with read end-plates). The 4 long straight sections house large equipment like septa for injection/ejection, RF-cavities and later (since 1986) electron cooling and an internal target and its associated detector (JETSET experiment). Two small copper tubes spanning across the ring are coaxial lines transmitting the stochastic cooling signals from pick up to kicker. (see also photos 8205747X, 8207133, 8207541X, 8301550X,8309026X)

Track distortion in a micromegas based large prototype of a Time Projection Chamber for the International Linear Collider

International Nuclear Information System (INIS)

Bhattacharya, Deb Sankar; Majumdar, Nayana; Sarkar, S.; Bhattacharya, S.; Mukhopadhyay, Supratik; Bhattacharya, P.; Attie, D.; Colas, P.; Ganjour, S.; Bhattacharya, Aparajita

2016-01-01

The principal particle tracker at the International Linear Collider (ILC) is planned to be a large Time Projection Chamber (TPC) where different Micro Pattern Gaseous Detector (MPGDs) candidate as the gaseous amplifier. A Micromegas (MM) based TPC can meet the ILC requirement of continuous and precise pattern recognition. Seven MM modules, working as the end-plate of a Large Prototype TPC (LPTPC) installed at DESY, have been tested with a 5 GeV electron beam. Due to the grounded peripheral frame of the MM modules, at low drift, the electric field lines near the detector edge remain no longer parallel to the TPC axis. This causes signal loss along the boundaries of the MM modules as well as distortion in the reconstructed track. In presence of magnetic field, the distorted electric field introduces ExB effect

Signals, systems, transforms, and digital signal processing with Matlab

CERN Document Server

Corinthios, Michael

2009-01-01

Continuous-Time and Discrete-Time Signals and SystemsIntroductionContinuous-Time SignalsPeriodic FunctionsUnit Step FunctionGraphical Representation of FunctionsEven and Odd Parts of a FunctionDirac-Delta ImpulseBasic Properties of the Dirac-Delta ImpulseOther Important Properties of the ImpulseContinuous-Time SystemsCausality, StabilityExamples of Electrical Continuous-Time SystemsMechanical SystemsTransfer Function and Frequency ResponseConvolution and CorrelationA Right-Sided and a Left-Sided FunctionConvolution with an Impulse and Its DerivativesAdditional Convolution PropertiesCorrelation FunctionProperties of the Correlation FunctionGraphical InterpretationCorrelation of Periodic FunctionsAverage, Energy and Power of Continuous-Time SignalsDiscrete-Time SignalsPeriodicityDifference EquationsEven/Odd DecompositionAverage Value, Energy and Power SequencesCausality, StabilityProblemsAnswers to Selected ProblemsFourier Series ExpansionTrigonometric Fourier SeriesExponential Fourier SeriesExponential versus ...

Quorum Quenching Revisited—From Signal Decays to Signalling Confusion

Directory of Open Access Journals (Sweden)

Kok-Gan Chan

2012-04-01

Full Text Available In a polymicrobial community, while some bacteria are communicating with neighboring cells (quorum sensing, others are interrupting the communication (quorum quenching, thus creating a constant arms race between intercellular communication. In the past decade, numerous quorum quenching enzymes have been found and initially thought to inactivate the signalling molecules. Though this is widely accepted, the actual roles of these quorum quenching enzymes are now being uncovered. Recent evidence extends the role of quorum quenching to detoxification or metabolism of signalling molecules as food and energy source; this includes “signalling confusion”, a term coined in this paper to refer to the phenomenon of non-destructive modification of signalling molecules. While quorum quenching has been explored as a novel anti-infective therapy targeting, quorum sensing evidence begins to show the development of resistance against quorum quenching.

Effect of Gymnodinium breve toxin in the rat phrenic nerve diaphragm preparation.

Science.gov (United States)

Gallagher, J. P.; Shinnick-Gallagher, P.

1980-01-01

1 The effects of a crude fraction of Gymnodinium breve toxin (GBTX) were studied on the rat phrenic nerve diaphragm preparation. 2 Indirectly stimulated muscle contractions were more sensitive to blockade by increasing concentrations of GBTX (0.25 microgram/ml to 10 micrograms/ml) than direct muscle contractions. 3 GBTX increased miniature endplate potential (m.e.p.p.) frequency and depolarized the resting membrane potential of the muscle fibres at the endplate and in non-synaptic regions of muscle fibre. 4 A concentration-dependent biphasic effect on m.e.p.p. amplitude was evident. At lower concentrations m.e.p.p. amplitudes were depressed whereas at high concentrations they were increased. 5 GBTX blocked endplate potentials (e.p.ps) in concentrations (0.5 microgram/ml to 2 micrograms/ml) that did not block m.e.p.ps. 6 Muscle fibre action potentials recorded from cells held at control membrane potential by hyperpolarizing current were not altered by toxin treatment. No repetitive e.p.ps, or muscle action potentials were observed. 7 These data suggest that GBTX may block indirectly stimulated muscle contractions and e.p.ps by depolarizing the nerve terminal in a manner similar to the observed depolarization of the muscle fibre. The depolarization of the nerve terminal may be sufficient to inhibit transmitter release. PMID:7190451

Presynaptic congenital myasthenic syndrome with a homozygous sequence variant in LAMA5 combines myopia, facial tics, and failure of neuromuscular transmission.

Science.gov (United States)

Maselli, Ricardo A; Arredondo, Juan; Vázquez, Jessica; Chong, Jessica X; Bamshad, Michael J; Nickerson, Deborah A; Lara, Marian; Ng, Fiona; Lo, Victoria L; Pytel, Peter; McDonald, Craig M

2017-08-01

Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics. Magnetic resonance imaging of brain showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation revealed 50% decrement of compound muscle action potential amplitudes and 250% facilitation immediately after exercise, Endplate studies identified a profound reduction of the endplate potential quantal content and endplates with normal postsynaptic folding that were denuded or partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin alpha-5 to SV2A and impaired laminin-521 cell-adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding alpha-laminins. © 2017 Wiley Periodicals, Inc.

Measurand transient signal suppressor

Science.gov (United States)

Bozeman, Richard J., Jr. (Inventor)

1994-01-01

A transient signal suppressor for use in a controls system which is adapted to respond to a change in a physical parameter whenever it crosses a predetermined threshold value in a selected direction of increasing or decreasing values with respect to the threshold value and is sustained for a selected discrete time interval is presented. The suppressor includes a sensor transducer for sensing the physical parameter and generating an electrical input signal whenever the sensed physical parameter crosses the threshold level in the selected direction. A manually operated switch is provided for adapting the suppressor to produce an output drive signal whenever the physical parameter crosses the threshold value in the selected direction of increasing or decreasing values. A time delay circuit is selectively adjustable for suppressing the transducer input signal for a preselected one of a plurality of available discrete suppression time and producing an output signal only if the input signal is sustained for a time greater than the selected suppression time. An electronic gate is coupled to receive the transducer input signal and the timer output signal and produce an output drive signal for energizing a control relay whenever the transducer input is a non-transient signal which is sustained beyond the selected time interval.

Adaptive signal processor

Energy Technology Data Exchange (ETDEWEB)

Walz, H.V.

1980-07-01

An experimental, general purpose adaptive signal processor system has been developed, utilizing a quantized (clipped) version of the Widrow-Hoff least-mean-square adaptive algorithm developed by Moschner. The system accommodates 64 adaptive weight channels with 8-bit resolution for each weight. Internal weight update arithmetic is performed with 16-bit resolution, and the system error signal is measured with 12-bit resolution. An adapt cycle of adjusting all 64 weight channels is accomplished in 8 ..mu..sec. Hardware of the signal processor utilizes primarily Schottky-TTL type integrated circuits. A prototype system with 24 weight channels has been constructed and tested. This report presents details of the system design and describes basic experiments performed with the prototype signal processor. Finally some system configurations and applications for this adaptive signal processor are discussed.

Adaptive signal processor

International Nuclear Information System (INIS)

Walz, H.V.

1980-07-01

An experimental, general purpose adaptive signal processor system has been developed, utilizing a quantized (clipped) version of the Widrow-Hoff least-mean-square adaptive algorithm developed by Moschner. The system accommodates 64 adaptive weight channels with 8-bit resolution for each weight. Internal weight update arithmetic is performed with 16-bit resolution, and the system error signal is measured with 12-bit resolution. An adapt cycle of adjusting all 64 weight channels is accomplished in 8 μsec. Hardware of the signal processor utilizes primarily Schottky-TTL type integrated circuits. A prototype system with 24 weight channels has been constructed and tested. This report presents details of the system design and describes basic experiments performed with the prototype signal processor. Finally some system configurations and applications for this adaptive signal processor are discussed

Bmp signaling mediates endoderm pouch morphogenesis by regulating Fgf signaling in zebrafish

Science.gov (United States)

Swartz, Mary E.; McCarthy, Neil; Norrie, Jacqueline L.; Eberhart, Johann K.

2016-01-01

The endodermal pouches are a series of reiterated structures that segment the pharyngeal arches and help pattern the vertebrate face. Multiple pathways regulate the complex process of endodermal development, including the Bone morphogenetic protein (Bmp) pathway. However, the role of Bmp signaling in pouch morphogenesis is poorly understood. Using genetic and chemical inhibitor approaches, we show that pouch morphogenesis requires Bmp signaling from 10-18 h post-fertilization, immediately following gastrulation. Blocking Bmp signaling during this window results in morphological defects to the pouches and craniofacial skeleton. Using genetic chimeras we show that Bmp signals directly to the endoderm for proper morphogenesis. Time-lapse imaging and analysis of reporter transgenics show that Bmp signaling is necessary for pouch outpocketing via the Fibroblast growth factor (Fgf) pathway. Double loss-of-function analyses demonstrate that Bmp and Fgf signaling interact synergistically in craniofacial development. Collectively, our analyses shed light on the tissue and signaling interactions that regulate development of the vertebrate face. PMID:27122171

To signal or not to signal: that should not be the question.

Science.gov (United States)

Faw, Harold W

2013-10-01

The purpose of the present research was to examine rates of turn signal use, a positive and potentially valuable means by which drivers can communicate. A second purpose was to explore factors that might impact these rates, including the modeling influence of other drivers. A series of observations involving more than 5600 vehicles making turns were recorded at a variety of intersections in British Columbia, Canada. Though the occurrence of signal use varied widely, ranging from a low of 54% to a high of 95%, the overall rate was 76%. Drivers used turn signals significantly less often when making right as compared with left turns, when traffic volume was higher, and when a designated turning lane was provided. In addition, compared with drivers following another vehicle not using signals, those following a vehicle with turn signals on were significantly more likely to activate their turn signals, suggesting a possible modeling effect. Both internal and external influences on turn signal use by drivers were considered. External factors explored in this research included direction of turn, traffic volume, intersection configuration, and the example of other drivers. It was concluded that the practice of signaling turns merits more research attention, since consistent use of signals is a potential contributor to enhanced safety for all road users. Copyright © 2013 Elsevier Ltd. All rights reserved.

TSLP signaling pathway map: a platform for analysis of TSLP-mediated signaling.

Science.gov (United States)

Zhong, Jun; Sharma, Jyoti; Raju, Rajesh; Palapetta, Shyam Mohan; Prasad, T S Keshava; Huang, Tai-Chung; Yoda, Akinori; Tyner, Jeffrey W; van Bodegom, Diederik; Weinstock, David M; Ziegler, Steven F; Pandey, Akhilesh

2014-01-01

Thymic stromal lymphopoietin (TSLP) is a four-helix bundle cytokine that plays a critical role in the regulation of immune responses and in the differentiation of hematopoietic cells. TSLP signals through a heterodimeric receptor complex consisting of an interleukin-7 receptor α chain and a unique TSLP receptor (TSLPR) [also known as cytokine receptor-like factor 2 (CRLF2)]. Cellular targets of TSLP include dendritic cells, B cells, mast cells, regulatory T (Treg) cells and CD4+ and CD8+ T cells. The TSLP/TSLPR axis can activate multiple signaling transduction pathways including the JAK/STAT pathway and the PI-3 kinase pathway. Aberrant TSLP/TSLPR signaling has been associated with a variety of human diseases including asthma, atopic dermatitis, nasal polyposis, inflammatory bowel disease, eosinophilic eosophagitis and, most recently, acute lymphoblastic leukemia. A centralized resource of the TSLP signaling pathway cataloging signaling events is not yet available. In this study, we present a literature-annotated resource of reactions in the TSLP signaling pathway. This pathway map is publicly available through NetPath (http://www.netpath.org/), an open access signal transduction pathway resource developed previously by our group. This map includes 236 molecules and 252 reactions that are involved in TSLP/TSLPR signaling pathway. We expect that the TSLP signaling pathway map will provide a rich resource to study the biology of this important cytokine as well as to identify novel therapeutic targets for diseases associated with dysregulated TSLP/TSLPR signaling. Database URL: http://www.netpath.org/pathways?path_id=NetPath_24.

Method of signal analysis

International Nuclear Information System (INIS)

Berthomier, Charles

1975-01-01

A method capable of handling the amplitude and the frequency time laws of a certain kind of geophysical signals is described here. This method is based upon the analytical signal idea of Gabor and Ville, which is constructed either in the time domain by adding an imaginary part to the real signal (in-quadrature signal), or in the frequency domain by suppressing negative frequency components. The instantaneous frequency of the initial signal is then defined as the time derivative of the phase of the analytical signal, and his amplitude, or envelope, as the modulus of this complex signal. The method is applied to three types of magnetospheric signals: chorus, whistlers and pearls. The results obtained by analog and numerical calculations are compared to results obtained by classical systems using filters, i.e. based upon a different definition of the concept of frequency. The precision with which the frequency-time laws are determined leads then to the examination of the principle of the method and to a definition of instantaneous power density spectrum attached to the signal, and to the first consequences of this definition. In this way, a two-dimensional representation of the signal is introduced which is less deformed by the analysis system properties than the usual representation, and which moreover has the advantage of being obtainable practically in real time [fr

The Hedgehog Signal Induced Modulation of Bone Morphogenetic Protein Signaling: An Essential Signaling Relay for Urinary Tract Morphogenesis

Science.gov (United States)

Nakagata, Naomi; Miyagawa, Shinichi; Suzuki, Kentaro; Kitazawa, Sohei; Yamada, Gen

2012-01-01

Background Congenital diseases of the urinary tract are frequently observed in infants. Such diseases present a number of developmental anomalies such as hydroureter and hydronephrosis. Although some genetically-modified mouse models of growth factor signaling genes reproduce urinary phenotypes, the pathogenic mechanisms remain obscure. Previous studies suggest that a portion of the cells in the external genitalia and bladder are derived from peri-cloacal mesenchymal cells that receive Hedgehog (Hh) signaling in the early developmental stages. We hypothesized that defects in such progenitor cells, which give rise to urinary tract tissues, may be a cause of such diseases. Methodology/Principal Findings To elucidate the pathogenic mechanisms of upper urinary tract malformations, we analyzed a series of Sonic hedgehog (Shh) deficient mice. Shh−/− displayed hydroureter and hydronephrosis phenotypes and reduced expression of several developmental markers. In addition, we suggested that Shh modulation at an early embryonic stage is responsible for such phenotypes by analyzing the Shh conditional mutants. Tissue contribution assays of Hh-responsive cells revealed that peri-cloacal mesenchymal cells, which received Hh signal secreted from cloacal epithelium, could contribute to the ureteral mesenchyme. Gain- and loss-of-functional mutants for Hh signaling revealed a correlation between Hh signaling and Bone morphogenetic protein (Bmp) signaling. Finally, a conditional ablation of Bmp receptor type IA (BmprIA) gene was examined in Hh-responsive cell lineages. This system thus made it possible to analyze the primary functions of the growth factor signaling relay. The defective Hh-to-Bmp signaling relay resulted in severe urinary tract phenotypes with a decrease in the number of Hh-responsive cells. Conclusions/Significance This study identified the essential embryonic stages for the pathogenesis of urinary tract phenotypes. These results suggested that Hh

The newest digital signal processing

International Nuclear Information System (INIS)

Lee, Chae Uk

2002-08-01

This book deal with the newest digital signal processing, which contains introduction on conception of digital signal processing, constitution and purpose, signal and system such as signal, continuos signal, discrete signal and discrete system, I/O expression on impress response, convolution, mutual connection of system and frequency character,z transform of definition, range, application of z transform and relationship with laplace transform, Discrete fourier, Fast fourier transform on IDFT algorithm and FFT application, foundation of digital filter of notion, expression, types, frequency characteristic of digital filter and design order of filter, Design order of filter, Design of FIR digital filter, Design of IIR digital filter, Adaptive signal processing, Audio signal processing, video signal processing and application of digital signal processing.

Mathematical properties of a semi-classical signal analysis method: Noisy signal case

KAUST Repository

Liu, Dayan

2012-08-01

Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. © 2012 IEEE.

Mathematical properties of a semi-classical signal analysis method: Noisy signal case

KAUST Repository

Liu, Dayan; Laleg-Kirati, Taous-Meriem

2012-01-01

Recently, a new signal analysis method based on a semi-classical approach has been proposed [1]. The main idea in this method is to interpret a signal as a potential of a Schrodinger operator and then to use the discrete spectrum of this operator to analyze the signal. In this paper, we are interested in a mathematical analysis of this method in discrete case considering noisy signals. © 2012 IEEE.

Improved prediction of signal peptides: SignalP 3.0

DEFF Research Database (Denmark)

Bendtsen, Jannick Dyrløv; Nielsen, Henrik; von Heijne, G.

2004-01-01

We describe improvements of the currently most popular method for prediction of classically secreted proteins, SignalP. SignalP consists of two different predictors based on neural network and hidden Markov model algorithms, where both components have been updated. Motivated by the idea that the ...

Numerical study on aerodynamics of banked wing in ground effect

Directory of Open Access Journals (Sweden)

Qing Jia

2016-03-01

Full Text Available Unlike conventional airplane, a WIG craft experiences righting moment and adverse yaw moment in banked turning in ground effect. Numerical simulations are carried out to study the aerodynamics of banked wing in ground effect. Configurations of rectangular wing and delta wing are considered, and performance of endplates and ailerons during banking are also studied. The study shows that righting moment increase nonlinearly with heeling angle, and endplates enhance the righting. The asymmetric aerodynamic distribution along span of wing with heeling angle introduces adverse yaw moment. Heeling in ground effect with small ground clearance increases the vertical aerodynamic force and makes WIG craft climb. Deflections of ailerons introduce lift decrease and a light pitching motion. Delta wing shows advantage in banked turning for smaller righting moment and adverse yaw moment during banking.

Tyrosine kinase signalling in breast cancer: Modulation of tyrosine kinase signalling in human breast cancer through altered expression of signalling intermediates

International Nuclear Information System (INIS)

Kairouz, Rania; Daly, Roger J

2000-01-01

The past decade has seen the definition of key signalling pathways downstream of receptor tyrosine kinases (RTKs) in terms of their components and the protein-protein interactions that facilitate signal transduction. Given the strong evidence that links signalling by certain families of RTKs to the progression of breast cancer, it is not surprising that the expression profile of key downstream signalling intermediates in this disease has also come under scrutiny, particularly because some exhibit transforming potential or amplify mitogenic signalling pathways when they are overexpressed. Reflecting the diverse cellular processes regulated by RTKs, it is now clear that altered expression of such signalling proteins in breast cancer may influence not only cellular proliferation (eg Grb2) but also the invasive properties of the cancer cells (eg EMS1/cortactin)

Partial view of the Axial Field Spectrometer (version R808)

CERN Multimedia

1980-01-01

The endplates of the cylindrical drift chamber is removed to access the electronics. The vertical Uranium/Scintillator Calorimeter is retracted. The detector on the frontface is a matrix of NaI-crystals for photon spectroscopy

A functional SNP in the regulatory region of the decay-accelerating factor gene associates with extraocular muscle pareses in myasthenia gravis

KAUST Repository

Heckmann, J M; Uwimpuhwe, H; Ballo, R; Kaur, M; Bajic, Vladimir B.; Prince, S

2009-01-01

Complement activation in myasthenia gravis (MG) may damage muscle endplate and complement regulatory proteins such as decay-accelerating factor (DAF) or CD55 may be protective. We hypothesize that the increased prevalence of severe extraocular

Wnt signaling in cancer

Science.gov (United States)

Zhan, T; Rindtorff, N; Boutros, M

2017-01-01

Wnt signaling is one of the key cascades regulating development and stemness, and has also been tightly associated with cancer. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities. Here, we review current insights into novel components of Wnt pathways and describe their impact on cancer development. Furthermore, we highlight expanding functions of Wnt signaling for both solid and liquid tumors. We also describe current findings how Wnt signaling affects maintenance of cancer stem cells, metastasis and immune control. Finally, we provide an overview of current strategies to antagonize Wnt signaling in cancer and challenges that are associated with such approaches. PMID:27617575

Signal Conditioning An Introduction to Continuous Wave Communication and Signal Processing

CERN Document Server

Das, Apurba

2012-01-01

"Signal Conditioning” is a comprehensive introduction to electronic signal processing. The book presents the mathematical basics including the implications of various transformed domain representations in signal synthesis and analysis in an understandable and lucid fashion and illustrates the theory through many applications and examples from communication systems. The ease to learn is supported by well-chosen exercises which give readers the flavor of the subject. Supplementary electronic materials available on http://extras.springer.com including MATLAB codes illuminating applications in the domain of one dimensional electrical signal processing, image processing and speech processing. The book is an introduction for students with a basic understanding in engineering or natural sciences.

Correlation of Respiratory Signals and Electrocardiogram Signals via Empirical Mode Decomposition

KAUST Repository

El Fiky, Ahmed Osama

2011-05-24

Recently Electrocardiogram (ECG) signals are being broadly used as an essential diagnosing tool in different clinical applications as they carry a reliable representation not only for cardiac activities, but also for other associated biological processes, like respiration. However, the process of recording and collecting them has usually suffered from the presence of some undesired noises, which in turn affects the reliability of such representations.Therefore, de-noising ECG signals became a hot research field for signal processing experts to ensure better and clear representation of the different cardiac activities. Given the nonlinear and non-stationary properties of ECGs, it is not a simple task to cancel the undesired noise terms without affecting the biological physics of them. In this study, we are interested in correlating the ECG signals with respiratory parameters, specifically the lung volume and lung pressure. We have focused on the concept of de-noising ECG signals by means of signal decomposition using an algorithm called the Empirical Mode Decomposition (EMD) where the original ECG signals are being decomposed into a set of intrinsic mode functions (IMF). Then, we have provided criteria based on which some of these IMFs have been adapted to reconstruct de-noised ECG version. Finally, we have utilized de-noised ECGs as well as IMFs for to study the correlation with lung volume and lung pressure. These correlation studies have showed some clear resemblance especially between the oscillations of ECGs and lung pressures.

Do MRI findings identify patients with low back pain or sciatica who respond better to particular interventions? A systematic review.

Science.gov (United States)

Steffens, Daniel; Hancock, Mark J; Pereira, Leani S M; Kent, Peter M; Latimer, Jane; Maher, Chris G

2016-04-01

Magnetic resonance imaging (MRI) can reveal a range of degenerative findings and anatomical abnormalities; however, the clinical importance of these remains uncertain and controversial. We aimed to investigate if the presence of MRI findings identifies patients with low back pain (LBP) or sciatica who respond better to particular interventions. MEDLINE, EMBASE and CENTRAL databases were searched. We included RCTs investigating MRI findings as treatment effect modifiers for patients with LBP or sciatica. We excluded studies with specific diseases as the cause of LBP. Risk of bias was assessed using the criteria of the Cochrane Back Review Group. Each MRI finding was examined for its individual capacity for effect modification. Eight published trials met the inclusion criteria. The methodological quality of trials was inconsistent. Substantial variability in MRI findings, treatments and outcomes across the eight trials prevented pooling of data. Patients with Modic type 1 when compared with patients with Modic type 2 had greater improvements in function when treated by Diprospan (steroid) injection, compared with saline. Patients with central disc herniation when compared with patients without central disc herniation had greater improvements in pain when treated by surgery, compared with rehabilitation. Although individual trials suggested that some MRI findings might be effect modifiers for specific interventions, none of these interactions were investigated in more than a single trial. High quality, adequately powered trials investigating MRI findings as effect modifiers are essential to determine the clinical importance of MRI findings in LBP and sciatica ( CRD42013006571).

Detection test of wireless network signal strength and GPS positioning signal in underground pipeline

Science.gov (United States)

Li, Li; Zhang, Yunwei; Chen, Ling

2018-03-01

In order to solve the problem of selecting positioning technology for inspection robot in underground pipeline environment, the wireless network signal strength and GPS positioning signal testing are carried out in the actual underground pipeline environment. Firstly, the strength variation of the 3G wireless network signal and Wi-Fi wireless signal provided by China Telecom and China Unicom ground base stations are tested, and the attenuation law of these wireless signals along the pipeline is analyzed quantitatively and described. Then, the receiving data of the GPS satellite signal in the pipeline are tested, and the attenuation of GPS satellite signal under underground pipeline is analyzed. The testing results may be reference for other related research which need to consider positioning in pipeline.

DMPD: Signal integration between IFNgamma and TLR signalling pathways in macrophages. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 16920490 Signal integration between IFNgamma and TLR signalling pathways in macroph...tml) (.csml) Show Signal integration between IFNgamma and TLR signalling pathways in macrophages. PubmedID 16920490 Title Signal inte...gration between IFNgamma and TLR signalling pathways in

Sinusoidal Representation of Acoustic Signals

Science.gov (United States)

Honda, Masaaki

Sinusoidal representation of acoustic signals has been an important tool in speech and music processing like signal analysis, synthesis and time scale or pitch modifications. It can be applicable to arbitrary signals, which is an important advantage over other signal representations like physical modeling of acoustic signals. In sinusoidal representation, acoustic signals are composed as sums of sinusoid (sine wave) with different amplitudes, frequencies and phases, which is based on the timedependent short-time Fourier transform (STFT). This article describes the principles of acoustic signal analysis/synthesis based on a sinusoid representation with focus on sine waves with rapidly varying frequency.

Non-Smad signaling pathways.

Science.gov (United States)

Mu, Yabing; Gudey, Shyam Kumar; Landström, Maréne

2012-01-01

Transforming growth factor-beta (TGFβ) is a key regulator of cell fate during embryogenesis and has also emerged as a potent driver of the epithelial-mesenchymal transition during tumor progression. TGFβ signals are transduced by transmembrane type I and type II serine/threonine kinase receptors (TβRI and TβRII, respectively). The activated TβR complex phosphorylates Smad2 and Smad3, converting them into transcriptional regulators that complex with Smad4. TGFβ also uses non-Smad signaling pathways such as the p38 and Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways to convey its signals. Ubiquitin ligase tumor necrosis factor (TNF)-receptor-associated factor 6 (TRAF6) and TGFβ-associated kinase 1 (TAK1) have recently been shown to be crucial for the activation of the p38 and JNK MAPK pathways. Other TGFβ-induced non-Smad signaling pathways include the phosphoinositide 3-kinase-Akt-mTOR pathway, the small GTPases Rho, Rac, and Cdc42, and the Ras-Erk-MAPK pathway. Signals induced by TGFβ are tightly regulated and specified by post-translational modifications of the signaling components, since they dictate the subcellular localization, activity, and duration of the signal. In this review, we discuss recent findings in the field of TGFβ-induced responses by non-Smad signaling pathways.

Alternatives to Pyrotechnic Distress Signals; Additional Signal Evaluation

Science.gov (United States)

2017-06-01

device performance standard that addresses Coast Guard project sponsor and stakeholders needs. 17. Key Words Visual Distress Signal Device (VDSD...devices. The report discussed the concept of “effective intensity,” as used by the International Association of Marine Aids to Navigation and Lighthouse...efficacy of Cyan as a signal color. In order to move forward, the RDC project team met with CG-ENG-4 and other Coast Guard stakeholders (Offices of

Signal existence verification (SEV) for GPS low received power signal detection using the time-frequency approach.

Science.gov (United States)

Jan, Shau-Shiun; Sun, Chih-Cheng

2010-01-01

The detection of low received power of global positioning system (GPS) signals in the signal acquisition process is an important issue for GPS applications. Improving the miss-detection problem of low received power signal is crucial, especially for urban or indoor environments. This paper proposes a signal existence verification (SEV) process to detect and subsequently verify low received power GPS signals. The SEV process is based on the time-frequency representation of GPS signal, and it can capture the characteristic of GPS signal in the time-frequency plane to enhance the GPS signal acquisition performance. Several simulations and experiments are conducted to show the effectiveness of the proposed method for low received power signal detection. The contribution of this work is that the SEV process is an additional scheme to assist the GPS signal acquisition process in low received power signal detection, without changing the original signal acquisition or tracking algorithms.

Biomedical signal and image processing

CERN Document Server

Najarian, Kayvan

2012-01-01

INTRODUCTION TO DIGITAL SIGNAL AND IMAGE PROCESSINGSignals and Biomedical Signal ProcessingIntroduction and OverviewWhat is a ""Signal""?Analog, Discrete, and Digital SignalsProcessing and Transformation of SignalsSignal Processing for Feature ExtractionSome Characteristics of Digital ImagesSummaryProblemsFourier TransformIntroduction and OverviewOne-Dimensional Continuous Fourier TransformSampling and NYQUIST RateOne-Dimensional Discrete Fourier TransformTwo-Dimensional Discrete Fourier TransformFilter DesignSummaryProblemsImage Filtering, Enhancement, and RestorationIntroduction and Overview

Poisson pre-processing of nonstationary photonic signals: Signals with equality between mean and variance.

Science.gov (United States)

Poplová, Michaela; Sovka, Pavel; Cifra, Michal

2017-01-01

Photonic signals are broadly exploited in communication and sensing and they typically exhibit Poisson-like statistics. In a common scenario where the intensity of the photonic signals is low and one needs to remove a nonstationary trend of the signals for any further analysis, one faces an obstacle: due to the dependence between the mean and variance typical for a Poisson-like process, information about the trend remains in the variance even after the trend has been subtracted, possibly yielding artifactual results in further analyses. Commonly available detrending or normalizing methods cannot cope with this issue. To alleviate this issue we developed a suitable pre-processing method for the signals that originate from a Poisson-like process. In this paper, a Poisson pre-processing method for nonstationary time series with Poisson distribution is developed and tested on computer-generated model data and experimental data of chemiluminescence from human neutrophils and mung seeds. The presented method transforms a nonstationary Poisson signal into a stationary signal with a Poisson distribution while preserving the type of photocount distribution and phase-space structure of the signal. The importance of the suggested pre-processing method is shown in Fano factor and Hurst exponent analysis of both computer-generated model signals and experimental photonic signals. It is demonstrated that our pre-processing method is superior to standard detrending-based methods whenever further signal analysis is sensitive to variance of the signal.

Multi-Modal Intelligent Traffic Signal Systems Signal Plans for Roadside Equipment

Data.gov (United States)

Department of Transportation — Data were collected during the Multi-Modal Intelligent Transportation Signal Systems (MMITSS) study. MMITSS is a next-generation traffic signal system that seeks to...

All-optical signal processing of OTDM and OFDM signals based on time-domain Optical Fourier Transformation

DEFF Research Database (Denmark)

Clausen, Anders; Guan, Pengyu; Mulvad, Hans Christian Hansen

2014-01-01

All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented.......All-optical time-domain Optical Fourier Transformation utilised for signal processing of ultra-high-speed OTDM signals and OFDM signals will be presented....

Multiscale Signal Analysis and Modeling

CERN Document Server

Zayed, Ahmed

2013-01-01

Multiscale Signal Analysis and Modeling presents recent advances in multiscale analysis and modeling using wavelets and other systems. This book also presents applications in digital signal processing using sampling theory and techniques from various function spaces, filter design, feature extraction and classification, signal and image representation/transmission, coding, nonparametric statistical signal processing, and statistical learning theory. This book also: Discusses recently developed signal modeling techniques, such as the multiscale method for complex time series modeling, multiscale positive density estimations, Bayesian Shrinkage Strategies, and algorithms for data adaptive statistics Introduces new sampling algorithms for multidimensional signal processing Provides comprehensive coverage of wavelets with presentations on waveform design and modeling, wavelet analysis of ECG signals and wavelet filters Reviews features extraction and classification algorithms for multiscale signal and image proce...

Two-dimensional signal analysis

CERN Document Server

Garello, René

2010-01-01

This title sets out to show that 2-D signal analysis has its own role to play alongside signal processing and image processing.Concentrating its coverage on those 2-D signals coming from physical sensors (such as radars and sonars), the discussion explores a 2-D spectral approach but develops the modeling of 2-D signals and proposes several data-oriented analysis techniques for dealing with them. Coverage is also given to potential future developments in this area.

Room Allocation Optimisation at the Technical University of Denmark

DEFF Research Database (Denmark)

Bagger, Niels-Christian Fink; Larsen, Jesper; Stidsen, Thomas Riis

2014-01-01

As at many other universities the Technical University of Denmark (DTU) faces the challenge of solving a case of the curriculum based university course timetabling problem (CUCTT) multiple times a year. However, there are some slight modications to the CUCTT problem usually described in the liter...... at overlapping time slots, since the students are to ensure by themselves that their courses do not overlap. The problem was rst considered in the masters' thesis [1] and the project here is an extension of the work done in that thesis....

Geotechnical classification of deep and ultra-deep Witwatersrand mining areas, South Africa

CSIR Research Space (South Africa)

Schweitzer, JK

1997-06-01

Full Text Available ?cantly with depth (e.g. Gurtunca and Gay 1993a, b; Roberts et al. 1994), numerous researchers stress the importance of, and requirement for, geotechnical information, es- pecially geological features at great depths (e.g. Adams et al. 1981; Gay et al. 1984; Gay 1986...; Gay and Jager 1986a, b; Roberts and Jager 1991, 1993; Kullman et al. 1994; Gay et al. 1995a, b). The geotechnical information must also be considered when proposing modi?cations to current mining methods (Johnson and Schweitzer 1996). Mineralium...

Traffic signal synchronization.

Science.gov (United States)

Huang, Ding-wei; Huang, Wei-neng

2003-05-01

The benefits of traffic signal synchronization are examined within the cellular automata approach. The microsimulations of traffic flow are obtained with different settings of signal period T and time delay delta. Both numerical results and analytical approximations are presented. For undersaturated traffic, the green-light wave solutions can be realized. For saturated traffic, the correlation among the traffic signals has no effect on the throughput. For oversaturated traffic, the benefits of synchronization are manifest only when stochastic noise is suppressed.

Adenylate Kinase and AMP Signaling Networks: Metabolic Monitoring, Signal Communication and Body Energy Sensing

Directory of Open Access Journals (Sweden)

Andre Terzic

2009-04-01

Full Text Available Adenylate kinase and downstream AMP signaling is an integrated metabolic monitoring system which reads the cellular energy state in order to tune and report signals to metabolic sensors. A network of adenylate kinase isoforms (AK1-AK7 are distributed throughout intracellular compartments, interstitial space and body fluids to regulate energetic and metabolic signaling circuits, securing efficient cell energy economy, signal communication and stress response. The dynamics of adenylate kinase-catalyzed phosphotransfer regulates multiple intracellular and extracellular energy-dependent and nucleotide signaling processes, including excitation-contraction coupling, hormone secretion, cell and ciliary motility, nuclear transport, energetics of cell cycle, DNA synthesis and repair, and developmental programming. Metabolomic analyses indicate that cellular, interstitial and blood AMP levels are potential metabolic signals associated with vital functions including body energy sensing, sleep, hibernation and food intake. Either low or excess AMP signaling has been linked to human disease such as diabetes, obesity and hypertrophic cardiomyopathy. Recent studies indicate that derangements in adenylate kinase-mediated energetic signaling due to mutations in AK1, AK2 or AK7 isoforms are associated with hemolytic anemia, reticular dysgenesis and ciliary dyskinesia. Moreover, hormonal, food and antidiabetic drug actions are frequently coupled to alterations of cellular AMP levels and associated signaling. Thus, by monitoring energy state and generating and distributing AMP metabolic signals adenylate kinase represents a unique hub within the cellular homeostatic network.

SignalGuru: Leveraging mobile phones for collaborative traffic signal schedule advisory

OpenAIRE

Koukoumidis, Emmanouil; Peh, Li-Shiuan; Martonosi, Margaret

2011-01-01

While traffic signals are necessary to safely control competing flows of traffic, they inevitably enforce a stop-and-go movement pattern that increases fuel consumption, reduces traffic flow and causes traffic jams. These side effects can be alleviated by providing drivers and their onboard computational devices (e.g., vehicle computer, smartphone) with information about the schedule of the traffic signals ahead. Based on when the signal ahead will turn green, drivers can then adjust speed so...

Topological signal processing

CERN Document Server

Robinson, Michael

2014-01-01

Signal processing is the discipline of extracting information from collections of measurements. To be effective, the measurements must be organized and then filtered, detected, or transformed to expose the desired information.  Distortions caused by uncertainty, noise, and clutter degrade the performance of practical signal processing systems. In aggressively uncertain situations, the full truth about an underlying signal cannot be known.  This book develops the theory and practice of signal processing systems for these situations that extract useful, qualitative information using the mathematics of topology -- the study of spaces under continuous transformations.  Since the collection of continuous transformations is large and varied, tools which are topologically-motivated are automatically insensitive to substantial distortion. The target audience comprises practitioners as well as researchers, but the book may also be beneficial for graduate students.

The Hippo signaling functions through the Notch signaling to regulate intrahepatic bile duct development in mammals

Science.gov (United States)

Wu, Nan; Nguyen, Quy; Wan, Ying; Zhou, Tiaohao; Venter, Julie; Frampton, Gabriel A; DeMorrow, Sharon; Pan, Duojia; Meng, Fanyin; Glaser, Shannon; Alpini, Gianfranco; Bai, Haibo

2018-01-01

The Hippo signaling pathway and the Notch signaling pathway are evolutionary conserved signaling cascades that have important roles in embryonic development of many organs. In murine liver, disruption of either pathway impairs intrahepatic bile duct development. Recent studies suggested that the Notch signaling receptor Notch2 is a direct transcriptional target of the Hippo signaling pathway effector YAP, and the Notch signaling is a major mediator of the Hippo signaling in maintaining biliary cell characteristics in adult mice. However, it remains to be determined whether the Hippo signaling pathway functions through the Notch signaling in intrahepatic bile duct development. We found that loss of the Hippo signaling pathway tumor suppressor Nf2 resulted in increased expression levels of the Notch signaling pathway receptor Notch2 in cholangiocytes but not in hepatocytes. When knocking down Notch2 on the background of Nf2 deficiency in mouse livers, the excessive bile duct development induced by Nf2 deficiency was suppressed by heterozygous and homozygous deletion of Notch2 in a dose-dependent manner. These results implicated that Notch signaling is one of the downstream effectors of the Hippo signaling pathway in regulating intrahepatic bile duct development. PMID:28581486

Distinction between the extracellular matrix of the nucleus pulposus and hyaline cartilage: a requisite for tissue engineering of intervertebral disc.

Science.gov (United States)

Mwale, F; Roughley, P; Antoniou, J

2004-12-15

Tissue engineering of intervertebral discs (IVD) using mesenchymal stem cells (MSCs) induced to differentiate into a disc-cell phenotype has been considered as an alternative treatment for disc degeneration. However, since there is no unique marker characteristic of discs and since hyaline cartilage and immature nucleus pulposus (NP) possess similar macromolecules in their extracellular matrix, it is currently difficult to recognize MSC conversion to a disc cell. This study was performed to compare the proteoglycan to collagen ratio (measured as GAG to hydroxyproline ratio) in the NP of normal disc to that of the hyaline cartilage of the endplate within the same group of individuals and test the hypothesis that this ratio can be used for in vivo studies to distinguish between a normal NP and hyaline cartilage phenotype. Whole human lumbar spine specimens from fresh cadavers, ranging in age from 12 weeks to 79 years, were used to harvest the IVDs and adjacent endplates. The GAG to hydroxyproline ratio within the NP of young adults is approximately 27:1, whereas the ratio within the hyaline cartilage endplate of the same aged individuals is about 2:1. The production of an extracellular matrix with a high proteoglycan to collagen ratio can be used in vivo to distinguish NP cells from chondrocytes, and could help in identifying a NP-like phenotype in vivo as opposed to a chondrocyte when MSCs are induced to differentiate for tissue engineering of a disc.

Distinction between the extracellular matrix of the nucleus pulposus and hyaline cartilage: a requisite for tissue engineering of intervertebral disc

Directory of Open Access Journals (Sweden)

Mwale F.

2004-12-01

Full Text Available Tissue engineering of intervertebral discs (IVD using mesenchymal stem cells (MSCs induced to differentiate into a disc-cell phenotype has been considered as an alternative treatment for disc degeneration. However, since there is no unique marker characteristic of discs and since hyaline cartilage and immature nucleus pulposus (NP possess similar macromolecules in their extracellular matrix, it is currently difficult to recognize MSC conversion to a disc cell. This study was performed to compare the proteoglycan to collagen ratio (measured as GAG to hydroxyproline ratio in the NP of normal disc to that of the hyaline cartilage of the endplate within the same group of individuals and test the hypothesis that this ratio can be used for in vivo studies to distinguish between a normal NP and hyaline cartilage phenotype. Whole human lumbar spine specimens from fresh cadavers, ranging in age from 12 weeks to 79 years, were used to harvest the IVDs and adjacent endplates. The GAG to hydroxyproline ratio within the NP of young adults is approximately 27:1, whereas the ratio within the hyaline cartilage endplate of the same aged individuals is about 2:1. The production of an extracellular matrix with a high proteoglycan to collagen ratio can be used in vivo to distinguish NP cells from chondrocytes, and could help in identifying a NP-like phenotype in vivo as opposed to a chondrocyte when MSCs are induced to differentiate for tissue engineering of a disc.

Finite element modelling of different CANDU fuel bundle types in various refuelling conditions

International Nuclear Information System (INIS)

Roman, M. R.; Ionescu, D. V.; Olteanu, G.; Florea, S.; Radut, A. C.

2016-01-01

The objective of this paper is to develop a finite element model for static strength analysis of the CANDU standard with 37 elements fuel bundle and the SEU43 with 43 elements fuel bundle design for various refuelling conditions. The computer code, ANSYS7.1, is used to simulate the axial compression in CANDU type fuel bundles subject to hydraulic drag loads, deflection of fuel elements, stresses and displacements in the end plates. Two possible situations for the fuelling machine side stops are considered in our analyses, as follows: the last fuel bundle is supported by the two side stops and a side stop can be blocked therefore, the last fuel bundle is supported by only one side stop. The results of the analyses performed are briefly presented and also illustrated in a graphical form. The finite element model developed in present study is verified against test results for endplate displacement and element bowing obtained from strength tests with fuel bundle string and fuelling machine side-stop simulators. Comparison of ANSYS model predictions with these experimental results led to a very good agreement. Despite the difference in hydraulic load between SEU43 and CANDU standard fuel bundles strings, the maximum stress in the SEU43 endplate is about the same with the maximum stress in the CANDU standard endplate. The comparative assessment reveals that SEU43 fuel bundle is able to withstand high flow rate without showing a significant geometric instability. (authors)

Comparative imaging features of brucellar and tuberculous spondylitis

International Nuclear Information System (INIS)

Sharif, H.S.; Aldeyan, O.; Clark, D.C.; Madkour, M.M.

1987-01-01

Images obtained with various modalities in 17 patients with Brucella spondylitis and 12 patients with tuberculous spondylitis were analyzed in order to identify distinguishing features. All patients underwent radiography, 21 underwent bone scintigraphy, and all underwent high-resolution CT and/or MR imaging. Characteristic findings in Brucella spondylitis included a predilection for the lumbar spine, bone destruction limited to the end-plates and associated with sclerosis, and disk space collapse (16 of 19) with disk vacuum phenomenon in eight and localized soft-tissue edema. MR imaging showed diffuse increased signal in vertebrae, disks, and adjacent soft tissues on long repetition time/long echo time studies (four patients). Tuberculosis spondylitis was characterized by a midthoracic predilection, diffuse vertebral destruction with gibbus deformity, severe disk collapse, and extensive paraspinal abscesses. MR imaging findings (three patients) were similar to but more severe than findings in Brucella spondylitis

Involvement of neurotrophin-3 (NT-3) in the functional elimination of synaptic contacts during neuromuscular development.

Science.gov (United States)

Garcia, Neus; Santafé, Manel M; Tomàs, Marta; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep

2010-04-05

Confocal immunohistochemistry shows that neurotrophin-3 (NT-3) and its receptor tropomyosin-related tyrosin kinase C (trkC) are present in both neonatal (P6) and adult (P45) mouse motor nerve terminals in neuromuscular junctions (NMJ) colocalized with several synaptic proteins. NT-3 incubation (1-3h, in the range 10-200ng/ml) does not change the size of the evoked and spontaneous endplate potentials at P45. However, NT-3 (1h, 100ng/ml) strongly potentiates evoked ACh release from the weak (70%) and the strong (50%) axonal inputs on dually innervated postnatal endplates (P6) but not in the most developed postnatal singly innervated synapses at P6. The present results indicate that NT-3 has a role in the developmental mechanism that eliminates redundant synapses though it cannot modulate synaptic transmission locally as the NMJ matures.

Biological signals classification and analysis

CERN Document Server

Kiasaleh, Kamran

2015-01-01

This authored monograph presents key aspects of signal processing analysis in the biomedical arena. Unlike wireless communication systems, biological entities produce signals with underlying nonlinear, chaotic nature that elude classification using the standard signal processing techniques, which have been developed over the past several decades for dealing primarily with standard communication systems. This book separates what is random from that which appears to be random, and yet is truly deterministic with random appearance. At its core, this work gives the reader a perspective on biomedical signals and the means to classify and process such signals. In particular, a review of random processes along with means to assess the behavior of random signals is also provided. The book also includes a general discussion of biological signals in order to demonstrate the inefficacy of the well-known techniques to correctly extract meaningful information from such signals. Finally, a thorough discussion of recently ...

Acoustic Signals and Systems

DEFF Research Database (Denmark)

2008-01-01

The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

The Signal Validation method of Digital Process Instrumentation System on signal conditioner for SMART

International Nuclear Information System (INIS)

Moon, Hee Gun; Park, Sang Min; Kim, Jung Seon; Shon, Chang Ho; Park, Heui Youn; Koo, In Soo

2005-01-01

The function of PIS(Process Instrumentation System) for SMART is to acquire the process data from sensor or transmitter. The PIS consists of signal conditioner, A/D converter, DSP(Digital Signal Process) and NIC(Network Interface Card). So, It is fully digital system after A/D converter. The PI cabinet and PDAS(Plant Data Acquisition System) in commercial plant is responsible for data acquisition of the sensor or transmitter include RTD, TC, level, flow, pressure and so on. The PDAS has the software that processes each sensor data and PI cabinet has the signal conditioner, which is need for maintenance and test. The signal conditioner has the potentiometer to adjust the span and zero for test and maintenance. The PIS of SMART also has the signal conditioner which has the span and zero adjust same as the commercial plant because the signal conditioner perform the signal condition for AD converter such as 0∼10Vdc. But, To adjust span and zero is manual test and calibration. So, This paper presents the method of signal validation and calibration, which is used by digital feature in SMART. There are I/E(current to voltage), R/E(resistor to voltage), F/E(frequency to voltage), V/V(voltage to voltage). Etc. In this paper show only the signal validation and calibration about I/E converter that convert level, pressure, flow such as 4∼20mA into signal for AD conversion such as 0∼10Vdc

SignalR blueprints

CERN Document Server

Ingebrigtsen, Einar

2015-01-01

This book is designed for software developers, primarily those with knowledge of C#, .NET, and JavaScript. Good knowledge and understanding of SignalR is assumed to allow efficient programming of core elements and applications in SignalR.

Calcium specificity signaling mechanisms in abscisic acid signal transduction in Arabidopsis guard cells

Science.gov (United States)

Brandt, Benjamin; Munemasa, Shintaro; Wang, Cun; Nguyen, Desiree; Yong, Taiming; Yang, Paul G; Poretsky, Elly; Belknap, Thomas F; Waadt, Rainer; Alemán, Fernando; Schroeder, Julian I

2015-01-01

A central question is how specificity in cellular responses to the eukaryotic second messenger Ca2+ is achieved. Plant guard cells, that form stomatal pores for gas exchange, provide a powerful system for in depth investigation of Ca2+-signaling specificity in plants. In intact guard cells, abscisic acid (ABA) enhances (primes) the Ca2+-sensitivity of downstream signaling events that result in activation of S-type anion channels during stomatal closure, providing a specificity mechanism in Ca2+-signaling. However, the underlying genetic and biochemical mechanisms remain unknown. Here we show impairment of ABA signal transduction in stomata of calcium-dependent protein kinase quadruple mutant plants. Interestingly, protein phosphatase 2Cs prevent non-specific Ca2+-signaling. Moreover, we demonstrate an unexpected interdependence of the Ca2+-dependent and Ca2+-independent ABA-signaling branches and the in planta requirement of simultaneous phosphorylation at two key phosphorylation sites in SLAC1. We identify novel mechanisms ensuring specificity and robustness within stomatal Ca2+-signaling on a cellular, genetic, and biochemical level. DOI: http://dx.doi.org/10.7554/eLife.03599.001 PMID:26192964

Seismic signals hard clipping overcoming

Science.gov (United States)

Olszowa, Paula; Sokolowski, Jakub

2018-01-01

In signal processing the clipping is understand as the phenomenon of limiting the signal beyond certain threshold. It is often related to overloading of a sensor. Two particular types of clipping are being recognized: soft and hard. Beyond the limiting value soft clipping reduces the signal real gain while the hard clipping stiffly sets the signal values at the limit. In both cases certain amount of signal information is lost. Obviously if one possess the model which describes the considered signal and the threshold value (which might be slightly more difficult to obtain in the soft clipping case), the attempt of restoring the signal can be made. Commonly it is assumed that the seismic signals take form of an impulse response of some specific system. This may lead to belief that the sine wave may be the most appropriate to fit in the clipping period. However, this should be tested. In this paper the possibility of overcoming the hard clipping in seismic signals originating from a geoseismic station belonging to an underground mine is considered. A set of raw signals will be hard-clipped manually and then couple different functions will be fitted and compared in terms of least squares. The results will be then analysed.

Signals in Science - On the Importance of Signaling in Gaining Attention in Science

NARCIS (Netherlands)

H.P. van Dalen (Hendrik); K. Henkens

2004-01-01

textabstractWhich signals are important in gaining attention in science? For a group of 1,371 scientific articles published in 17 demography journals in the years 1990-1992 we track their influence and discern which signals are important in receiving citations. Three types of signals are examined:

Signal flow analysis

CERN Document Server

Abrahams, J R; Hiller, N

1965-01-01

Signal Flow Analysis provides information pertinent to the fundamental aspects of signal flow analysis. This book discusses the basic theory of signal flow graphs and shows their relation to the usual algebraic equations.Organized into seven chapters, this book begins with an overview of properties of a flow graph. This text then demonstrates how flow graphs can be applied to a wide range of electrical circuits that do not involve amplification. Other chapters deal with the parameters as well as circuit applications of transistors. This book discusses as well the variety of circuits using ther

Measuring displacement signal with an accelerometer

International Nuclear Information System (INIS)

Han, Sang Bo

2010-01-01

An effective and simple way to reconstruct displacement signal from a measured acceleration signal is proposed in this paper. To reconstruct displacement signal by means of double-integrating the time domain acceleration signal, the Nyquist frequency of the digital sampling of the acceleration signal should be much higher than the highest frequency component of the signal. On the other hand, to reconstruct displacement signal by taking the inverse Fourier transform, the magnitude of the significant frequency components of the Fourier transform of the acceleration signal should be greater than the 6 dB increment line along the frequency axis. With a predetermined resolution in time and frequency domain, determined by the sampling rate to measure and record the original signal, reconstructing high-frequency signals in the time domain and reconstructing low-frequency signals in the frequency domain will produce biased errors. Furthermore, because of the DC components inevitably included in the sampling process, low-frequency components of the signals are overestimated when displacement signals are reconstructed from the Fourier transform of the acceleration signal. The proposed method utilizes curve-fitting around the significant frequency components of the Fourier transform of the acceleration signal before it is inverse-Fourier transformed. Curve-fitting around the dominant frequency components provides much better results than simply ignoring the insignificant frequency components of the signal

Biomedical signals and systems

CERN Document Server

Tranquillo, Joseph V

2013-01-01

Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

Photoacoustic signal and noise analysis for Si thin plate: signal correction in frequency domain.

Science.gov (United States)

Markushev, D D; Rabasović, M D; Todorović, D M; Galović, S; Bialkowski, S E

2015-03-01

Methods for photoacoustic signal measurement, rectification, and analysis for 85 μm thin Si samples in the 20-20 000 Hz modulation frequency range are presented. Methods for frequency-dependent amplitude and phase signal rectification in the presence of coherent and incoherent noise as well as distortion due to microphone characteristics are presented. Signal correction is accomplished using inverse system response functions deduced by comparing real to ideal signals for a sample with well-known bulk parameters and dimensions. The system response is a piece-wise construction, each component being due to a particular effect of the measurement system. Heat transfer and elastic effects are modeled using standard Rosencweig-Gersho and elastic-bending theories. Thermal diffusion, thermoelastic, and plasmaelastic signal components are calculated and compared to measurements. The differences between theory and experiment are used to detect and correct signal distortion and to determine detector and sound-card characteristics. Corrected signal analysis is found to faithfully reflect known sample parameters.

Wavelet analysis for nonstationary signals

International Nuclear Information System (INIS)

Penha, Rosani Maria Libardi da

1999-01-01

Mechanical vibration signals play an important role in anomalies identification resulting of equipment malfunctioning. Traditionally, Fourier spectral analysis is used where the signals are assumed to be stationary. However, occasional transient impulses and start-up process are examples of nonstationary signals that can be found in mechanical vibrations. These signals can provide important information about the equipment condition, as early fault detection. The Fourier analysis can not adequately be applied to nonstationary signals because the results provide data about the frequency composition averaged over the duration of the signal. In this work, two methods for nonstationary signal analysis are used: Short Time Fourier Transform (STFT) and wavelet transform. The STFT is a method of adapting Fourier spectral analysis for nonstationary application to time-frequency domain. To have a unique resolution throughout the entire time-frequency domain is its main limitation. The wavelet transform is a new analysis technique suitable to nonstationary signals, which handles the STFT drawbacks, providing multi-resolution frequency analysis and time localization in a unique time-scale graphic. The multiple frequency resolutions are obtained by scaling (dilatation/compression) the wavelet function. A comparison of the conventional Fourier transform, STFT and wavelet transform is made applying these techniques to: simulated signals, arrangement rotor rig vibration signal and rotate machine vibration signal Hanning window was used to STFT analysis. Daubechies and harmonic wavelets were used to continuos, discrete and multi-resolution wavelet analysis. The results show the Fourier analysis was not able to detect changes in the signal frequencies or discontinuities. The STFT analysis detected the changes in the signal frequencies, but with time-frequency resolution problems. The wavelet continuos and discrete transform demonstrated to be a high efficient tool to detect

Critical nodes in signalling pathways

DEFF Research Database (Denmark)

Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

2006-01-01

Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...... using insulin signalling as a model system....

The Evolution of Covert Signaling.

Science.gov (United States)

Smaldino, Paul E; Flamson, Thomas J; McElreath, Richard

2018-03-20

Human sociality depends upon the benefits of mutual aid and extensive communication. However, diverse norms and preferences complicate mutual aid, and ambiguity in meaning hinders communication. Here we demonstrate that these two problems can work together to enhance cooperation through the strategic use of deliberately ambiguous signals: covert signaling. Covert signaling is the transmission of information that is accurately received by its intended audience but obscured when perceived by others. Such signals may allow coordination and enhanced cooperation while also avoiding the alienation or hostile reactions of individuals with different preferences. Although the empirical literature has identified potential mechanisms of covert signaling, such as encryption in humor, there is to date no formal theory of its dynamics. We introduce a novel mathematical model to assess when a covert signaling strategy will evolve, as well as how receiver attitudes coevolve with covert signals. Covert signaling plausibly serves an important function in facilitating within-group cooperative assortment by allowing individuals to pair up with similar group members when possible and to get along with dissimilar ones when necessary. This mechanism has broad implications for theories of signaling and cooperation, humor, social identity, political psychology, and the evolution of human cultural complexity.

Signal multiplexing scheme for LINAC

International Nuclear Information System (INIS)

Sujo, C.I.; Mohan, Shyam; Joshi, Gopal; Singh, S.K.; Karande, Jitendra

2004-01-01

For the proper operation of the LINAC some signals, RF (radio frequency) as well as LF (low frequency) have to be available at the Master Control Station (MCS). These signals are needed to control, calibrate and characterize the RF fields in the resonators. This can be achieved by proper multiplexing of various signals locally and then routing the selected signals to the MCS. A multiplexing scheme has been designed and implemented, which will allow the signals from the selected cavity to the MCS. High isolation between channels and low insertion loss for a given signal are important issues while selecting the multiplexing scheme. (author)

Signal Separation of Helicopter Radar Returns Using Wavelet-Based Sparse Signal Optimisation

Science.gov (United States)

2016-10-01

helicopter from the composite radar returns. The received signal consists of returns from the rotating main and tail rotor blades, the helicopter body...is used to separate the main and tail rotor blade components of a helicopter from the composite radar returns. The received signal consists of returns...Two algorithms are presented in the report to separately extract main rotor blade returns and tail rotor blade returns from the composite signal

Signals and systems

CERN Document Server

Rao, K Deergha

2018-01-01

This textbook covers the fundamental theories of signals and systems analysis, while incorporating recent developments from integrated circuits technology into its examples. Starting with basic definitions in signal theory, the text explains the properties of continuous-time and discrete-time systems and their representation by differential equations and state space. From those tools, explanations for the processes of Fourier analysis, the Laplace transform, and the z-Transform provide new ways of experimenting with different kinds of time systems. The text also covers the separate classes of analog filters and their uses in signal processing applications. Intended for undergraduate electrical engineering students, chapter sections include exercise for review and practice for the systems concepts of each chapter. Along with exercises, the text includes MATLAB-based examples to allow readers to experiment with signals and systems code on their own. An online repository of the MATLAB code from this textbook can...

Phantom phone signals: An investigation into the prevalence and predictors of imagined cell phone signals

NARCIS (Netherlands)

Tanis, M.A.; Beukeboom, C.J.; Hartmann, T.; Vermeulen, I.E.

2015-01-01

This paper aims to elucidate the peculiar phenomenon of imagined cell phone signals, or Phantom Phone Signals (PPS), which is defined as an individual's perception of a phone signal, indicating an incoming call, message, or social media notification, when in fact no such signal was transmitted. A

Experimental Investigation of the End Plate Instability in the Extension of Polymer Melts in a Filament Stretch Rheometer. P.-Y. Longin, H. K. Rasmussen, A. Bach and O. Hassager

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Longin, Pierre-Yves; Bach, Anders

2001-01-01

We consider here a particular instability, an axis symmetry breaking meniscus instability, that occurs under certain conditions in the transient filament stretching apparatus near the endplates as the plates are separated. Spiegelberg and McKinley [1] investigated this instability development in ...

Radiation signal processing system

International Nuclear Information System (INIS)

Bennett, M.; Knoll, G.; Strange, D.

1980-01-01

An improved signal processing system for radiation imaging apparatus comprises: a radiation transducer producing transducer signals proportional to apparent spatial coordinates of detected radiation events; means for storing true spatial coordinates corresponding to a plurality of predetermined apparent spatial coordinates relative to selected detected radiation events said means for storing responsive to said transducer signal and producing an output signal representative of said true spatial coordinates; and means for interpolating the true spatial coordinates of the detected radiation events located intermediate the stored true spatial coordinates, said means for interpolating communicating with said means for storing

Signal sampling circuit

NARCIS (Netherlands)

Louwsma, S.M.; Vertregt, Maarten

2011-01-01

A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

Signal sampling circuit

NARCIS (Netherlands)

Louwsma, S.M.; Vertregt, Maarten

2010-01-01

A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

Bioelectric Signal Measuring System

Science.gov (United States)

Guadarrama-Santana, A.; Pólo-Parada, L.; García-Valenzuela, A.

2015-01-01

We describe a low noise measuring system based on interdigitated electrodes for sensing bioelectrical signals. The system registers differential voltage measurements in order of microvolts. The base noise during measurements was in nanovolts and thus, the sensing signals presented a very good signal to noise ratio. An excitation voltage of 1Vrms with 10 KHz frequency was applied to an interdigitated capacitive sensor without a material under test and to a mirror device simultaneously. The output signals of both devices was then subtracted in order to obtain an initial reference value near cero volts and reduce parasitic capacitances due to the electronics, wiring and system hardware as well. The response of the measuring system was characterized by monitoring temporal bioelectrical signals in real time of biological materials such as embryo chicken heart cells and bovine suprarenal gland cells.

Signal interaction of Hedgehog/GLI and epidermal growth factor receptor signaling in cancer development

International Nuclear Information System (INIS)

Eberl, M.

2012-01-01

The subject of this PhD thesis is based on the cooperation of Hedgehog (HH)/GLI with epidermal growth factor receptor (EGFR) signaling synergistically promoting oncogenic transformation and cancer growth. In previous studies we have demonstrated that the HH/GLI and EGFR signaling pathways interact synergistically resulting not only in selective induction of HH/GLI-EGFR target genes, but also in the onset of oncogenic transformation and tumor formation (Kasper, Schnidar et al. 2006; Schnidar, Eberl et al. 2009). However, the molecular key mediators acting downstream of HH/GLI and EGFR signal cooperation were largely unknown and the in vivo evidence for the therapeutic relevance of HH/GLI and EGFR signal cooperation in HH-associated cancers was lacking. During my PhD thesis I could demonstrate that the integration of EGFR and HH/GLI signaling involves activation of RAS/MEK/ERK and JUN/AP1 signaling in response to EGFR activation. Furthermore I succeeded in identifying genes, including stem cell- (SOX2, SOX9), tumor growth- (JUN, TGFA, FGF19) and metastasis-associated genes (SPP1/osteopontin, CXCR4) that showed synergistic transcriptional activation by HH/GLI-EGFR signal integration. Importantly, I could demonstrate that these genes arrange themselves within a stable interdependent signaling network, which is required for in vivo growth of basal cell carcinoma (BCC) and tumor-initiating pancreatic cancer cells. These data validate EGFR signaling as additional drug target in HH/GLI driven cancers and provide new therapeutic strategies based on combined targeting of cooperative HH/GLI-EGFR signaling and selected downstream target genes (Eberl, Klingler et al. 2012). (author) [de

Advanced optical signal processing of broadband parallel data signals

DEFF Research Database (Denmark)

Oxenløwe, Leif Katsuo; Hu, Hao; Kjøller, Niels-Kristian

2016-01-01

Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration.......Optical signal processing may aid in reducing the number of active components in communication systems with many parallel channels, by e.g. using telescopic time lens arrangements to perform format conversion and allow for WDM regeneration....

Detection of signals in noise

CERN Document Server

Whalen, Anthony D; Declaris, Nicholas

1971-01-01

Detection of Signals in Noise serves as an introduction to the principles and applications of the statistical theory of signal detection. The book discusses probability and random processes; narrowband signals, their complex representation, and their properties described with the aid of the Hilbert transform; and Gaussian-derived processes. The text also describes the application of hypothesis testing for the detection of signals and the fundamentals required for statistical detection of signals in noise. Problem exercises, references, and a supplementary bibliography are included after each c

Paracrine signaling in a bacterium.

Science.gov (United States)

López, Daniel; Vlamakis, Hera; Losick, Richard; Kolter, Roberto

2009-07-15

Cellular differentiation is triggered by extracellular signals that cause target cells to adopt a particular fate. Differentiation in bacteria typically involves autocrine signaling in which all cells in the population produce and respond to the same signal. Here we present evidence for paracrine signaling in bacterial populations-some cells produce a signal to which only certain target cells respond. Biofilm formation in Bacillus involves two centrally important signaling molecules, ComX and surfactin. ComX triggers the production of surfactin. In turn, surfactin causes a subpopulation of cells to produce an extracellular matrix. Cells that produced surfactin were themselves unable to respond to it. Likewise, once surfactin-responsive cells commenced matrix production, they no longer responded to ComX and could not become surfactin producers. Insensitivity to ComX was the consequence of the extracellular matrix as mutant cells unable to make matrix responded to both ComX and surfactin. Our results demonstrate that extracellular signaling was unidirectional, with one subpopulation producing a signal and a different subpopulation responding to it. Paracrine signaling in a bacterial population ensures the maintenance, over generations, of particular cell types even in the presence of molecules that would otherwise cause those cells to differentiate into other cell types.

Machine intelligence and signal processing

CERN Document Server

Vatsa, Mayank; Majumdar, Angshul; Kumar, Ajay

2016-01-01

This book comprises chapters on key problems in machine learning and signal processing arenas. The contents of the book are a result of a 2014 Workshop on Machine Intelligence and Signal Processing held at the Indraprastha Institute of Information Technology. Traditionally, signal processing and machine learning were considered to be separate areas of research. However in recent times the two communities are getting closer. In a very abstract fashion, signal processing is the study of operator design. The contributions of signal processing had been to device operators for restoration, compression, etc. Applied Mathematicians were more interested in operator analysis. Nowadays signal processing research is gravitating towards operator learning – instead of designing operators based on heuristics (for example wavelets), the trend is to learn these operators (for example dictionary learning). And thus, the gap between signal processing and machine learning is fast converging. The 2014 Workshop on Machine Intel...

Signals and systems for dummies

CERN Document Server

Wickert, Mark

2013-01-01

Getting mixed signals in your signals and systems course? The concepts covered in a typical signals and systems course are often considered by engineering students to be some of the most difficult to master. Thankfully, Signals & Systems For Dummies is your intuitive guide to this tricky course, walking you step-by-step through some of the more complex theories and mathematical formulas in a way that is easy to understand. From Laplace Transforms to Fourier Analyses, Signals & Systems For Dummies explains in plain English the difficult concepts that can trip you up

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

Energy Technology Data Exchange (ETDEWEB)

Ham, Young-Mi, E-mail: youngmi_ham@hms.harvard.edu [College of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States); Mahoney, Sarah Jane [Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States)

2013-06-10

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors.

Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

International Nuclear Information System (INIS)

Ham, Young-Mi; Mahoney, Sarah Jane

2013-01-01

The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors

Multimodal signalling in estrildid finches

DEFF Research Database (Denmark)

Gomes, A. C. R.; Funghi, C.; Soma, M.

2017-01-01

Sexual traits (e.g. visual ornaments, acoustic signals, courtship behaviour) are often displayed together as multimodal signals. Some hypotheses predict joint evolution of different sexual signals (e.g. to increase the efficiency of communication) or that different signals trade off with each other...... (e.g. due to limited resources). Alternatively, multiple signals may evolve independently for different functions, or to communicate different information (multiple message hypothesis). We evaluated these hypotheses with a comparative study in the family Estrildidae, one of the largest songbird...... compromise, but generally courtship dance also evolved independently from other signals. Instead of correlated evolution, we found that song, dance and colour are each related to different socio-ecological traits. Song complexity evolved together with ecological generalism, song performance with investment...

Experiment and practice on signal processing

International Nuclear Information System (INIS)

2002-11-01

The contents of this book contains basic practice of CEM Tool, discrete time signal and experiment and practice of system, experiment and practice of discrete time signal sampling, practice of frequency analysis, experiment of digital filter design, application of digital signal processing, project related voice, basic principle of signal processing, the technique of basic image signal processing, biology astronomy and Robot soccer with apply of image signal processing technique, control video signal and project related image. It also has an introduction of CEM Linker I. O in the end.

Experiment and practice on signal processing

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-11-15

The contents of this book contains basic practice of CEM Tool, discrete time signal and experiment and practice of system, experiment and practice of discrete time signal sampling, practice of frequency analysis, experiment of digital filter design, application of digital signal processing, project related voice, basic principle of signal processing, the technique of basic image signal processing, biology astronomy and Robot soccer with apply of image signal processing technique, control video signal and project related image. It also has an introduction of CEM Linker I. O in the end.

Signal anomaly detection and characterization

International Nuclear Information System (INIS)

Morgenstern, V.M.; Upadhyaya, B.R.; Gloeckler, O.

1988-08-01

As part of a comprehensive signal validation system, we have developed a signal anomaly detector, without specifically establishing the cause of the anomaly. A signal recorded from process instrumentation is said to have an anomaly, if during steady-state operation, the deviation in the level of the signal, its root-mean-square (RMS) value, or its statistical distribution changes by a preset value. This deviation could be an unacceptable increase or a decrease in the quantity being monitored. An anomaly in a signal may be characterized by wideband or single-frequency noise, bias error, pulse-type error, nonsymmetric behavior, or a change in the signal bandwidth. Various signatures can be easily computed from data samples and compared against specified threshold values. We want to point out that in real processes, pulses can appear with different time widths, and at different rates of change of the signal. Thus, in characterizing an anomaly as a pulse-type, the fastest pulse width is constrained by the signal sampling interval. For example, if a signal is sampled at 100 Hz, we will not be able to detect pulses occurring at kHz rates. Discussion with utility and Combustion Engineering personnel indicated that it is not practical to detect pulses having a narrow time width. 9 refs., 11 figs., 8 tabs

Signals, processes, and systems an interactive multimedia introduction to signal processing

CERN Document Server

Karrenberg, Ulrich

2013-01-01

This is a very new concept for learning Signal Processing, not only from the physically-based scientific fundamentals, but also from the didactic perspective, based on modern results of brain research. The textbook together with the DVD form a learning system that provides investigative studies and enables the reader to interactively visualize even complex processes. The unique didactic concept is built on visualizing signals and processes on the one hand, and on graphical programming of signal processing systems on the other. The concept has been designed especially for microelectronics, computer technology and communication. The book allows to develop, modify, and optimize useful applications using DasyLab - a professional and globally supported software for metrology and control engineering. With the 3rd edition, the software is also suitable for 64 bit systems running on Windows 7. Real signals can be acquired, processed and played on the sound card of your computer. The book provides more than 200 pre-pr...

Sexual signalling in female crested macaques and the evolution of primate fertility signals.

Science.gov (United States)

Higham, James P; Heistermann, Michael; Saggau, Carina; Agil, Muhammad; Perwitasari-Farajallah, Dyah; Engelhardt, Antje

2012-06-18

Female signals of fertility have evolved in diverse taxa. Among the most interesting study systems are those of multimale multifemale group-living primates, where females signal fertility to males through multiple signals, and in which there is substantial inter-specific variation in the composition and reliability of such signals. Among the macaques, some species display reliable behavioural and/or anogenital signals while others do not. One cause of this variation may be differences in male competitive regimes: some species show marked sexual dimorphism and reproductive skew, with males fighting for dominance, while others show low dimorphism and skew, with males queuing for dominance. As such, there is variation in the extent to which rank is a reliable proxy for male competitiveness, which may affect the extent to which it is in females' interest to signal ovulation reliably. However, data on ovulatory signals are absent from species at one end of the macaque continuum, where selection has led to high sexual dimorphism and male reproductive skew. Here we present data from 31 cycles of 19 wild female crested macaques, a highly sexually dimorphic species with strong mating skew. We collected measures of ovarian hormone data from faeces, sexual swelling size from digital images, and male and female behaviour. We show that both sexual swelling size and female proceptivity are graded-signals, but relatively reliable indicators of ovulation, with swelling size largest and female proceptive behaviours most frequent around ovulation. Sexual swelling size was also larger in conceptive cycles. Male mating behaviour was well timed to female ovulation, suggesting that males had accurate information about this. Though probabilistic, crested macaque ovulatory signals are relatively reliable. We argue that in species where males fight over dominance, male dominance rank is surrogate for competitiveness. Under these circumstances it is in the interest of females to increase

Sexual signalling in female crested macaques and the evolution of primate fertility signals

Directory of Open Access Journals (Sweden)

Higham James P

2012-06-01

Full Text Available Abstract Background Female signals of fertility have evolved in diverse taxa. Among the most interesting study systems are those of multimale multifemale group-living primates, where females signal fertility to males through multiple signals, and in which there is substantial inter-specific variation in the composition and reliability of such signals. Among the macaques, some species display reliable behavioural and/or anogenital signals while others do not. One cause of this variation may be differences in male competitive regimes: some species show marked sexual dimorphism and reproductive skew, with males fighting for dominance, while others show low dimorphism and skew, with males queuing for dominance. As such, there is variation in the extent to which rank is a reliable proxy for male competitiveness, which may affect the extent to which it is in females’ interest to signal ovulation reliably. However, data on ovulatory signals are absent from species at one end of the macaque continuum, where selection has led to high sexual dimorphism and male reproductive skew. Here we present data from 31 cycles of 19 wild female crested macaques, a highly sexually dimorphic species with strong mating skew. We collected measures of ovarian hormone data from faeces, sexual swelling size from digital images, and male and female behaviour. Results We show that both sexual swelling size and female proceptivity are graded-signals, but relatively reliable indicators of ovulation, with swelling size largest and female proceptive behaviours most frequent around ovulation. Sexual swelling size was also larger in conceptive cycles. Male mating behaviour was well timed to female ovulation, suggesting that males had accurate information about this. Conclusion Though probabilistic, crested macaque ovulatory signals are relatively reliable. We argue that in species where males fight over dominance, male dominance rank is surrogate for competitiveness. Under these

The association between inflammatory back pain characteristics and MRI findings in the spine and sacroiliac joints

DEFF Research Database (Denmark)

Arnbak, Bodil; Jurik, Anne G; Jensen, Tue S

2018-01-01

OBJECTIVE: To investigate the association between MRI findings at the sacroiliac joints (SIJs) and vertebral endplates and pain characteristics assumed to be indicative of axial inflammation. METHODS: Patients aged 18-40 years with persistent low back pain referred to an outpatient spine clinic...

Molecular and Cellular Signaling

CERN Document Server

Beckerman, Martin

2005-01-01

A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

VLSI signal processing technology

CERN Document Server

Swartzlander, Earl

1994-01-01

This book is the first in a set of forthcoming books focussed on state-of-the-art development in the VLSI Signal Processing area. It is a response to the tremendous research activities taking place in that field. These activities have been driven by two factors: the dramatic increase in demand for high speed signal processing, especially in consumer elec­ tronics, and the evolving microelectronic technologies. The available technology has always been one of the main factors in determining al­ gorithms, architectures, and design strategies to be followed. With every new technology, signal processing systems go through many changes in concepts, design methods, and implementation. The goal of this book is to introduce the reader to the main features of VLSI Signal Processing and the ongoing developments in this area. The focus of this book is on: • Current developments in Digital Signal Processing (DSP) pro­ cessors and architectures - several examples and case studies of existing DSP chips are discussed in...

Zinc Signals and Immunity.

Science.gov (United States)

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

Cooperative ethylene receptor signaling

OpenAIRE

Liu, Qian; Wen, Chi-Kuang

2012-01-01

The gaseous plant hormone ethylene is perceived by a family of five ethylene receptor members in the dicotyledonous model plant Arabidopsis. Genetic and biochemical studies suggest that the ethylene response is suppressed by ethylene receptor complexes, but the biochemical nature of the receptor signal is unknown. Without appropriate biochemical measures to trace the ethylene receptor signal and quantify the signal strength, the biological significance of the modulation of ethylene responses ...

Farmacologia da unidade motora: aspectos de interesse em neurologia Pharmacology of motor end-plate: aspects related to neurology

Directory of Open Access Journals (Sweden)

Paulina Sannomiya

1975-09-01

Full Text Available Os AA fazem revisão sobre a unidade motora em seu aspecto morfológico, fisiológico e farmacológico como base para o estudo e tratamento da miastenia grave e da síndrome miastênica. Estudos eletromiográficos, farmacológicos e eletrofisiológicos, realizados por diversos autores, determinam características especiais que definem a miastenia grave e a síndrome miastênica. Certos sinais e sintomas, comumente observados em casos de envenenamento por elapídeos, são semelhantes aos causados por drogas bloqueadoras neuromusculares.In order to understand the treatment of miasthenia gravis and miasthenic sindrome, the morphology, physiology and pharmacology of the motor unit were reviewed. Electromiographic, pharmacologic and electrophysiologic studies accomplished by several authors have special caractheristics which define miasthenia gravis and miasthenic sindrome. Certain venoms such as those from Elapidae can produce signals and symptoms resembling those produced by neuromuscular blocking drugs.

Design of a distributed radiator target for inertial fusion driven from two sides with heavy ion beams

International Nuclear Information System (INIS)

Tabak, M.; Callahan-Miller, D.

1997-01-01

We describe the status of a distributed radiator heavy ion target design. In integrated calculations this target ignited and produced 390-430 MJ of yieldwhen driven with 5.8-6.5 MJ of 3-4 GeV Pb ions. The target has cylindrical symmetry with disk endplates. The ions uniformly illuminate these endplates in a 5mm radius spot. We discuss the considerations which led to this design together with some previously unused design features: low density hohlraum walls in approximate pressure balance with internal low-Z fill materials, radiationsymmetry determined by the position of the radiator materials and particle ranges, and early time pressure symmetry possibly influenced by radiation shims. We discuss how this target scales to lower input energy or to lower beam power. Variant designs with more realistic beam focusing strategies are also discussed. We show the tradeoffs required for targets which accept higher particle energies

Vertebral physitis: a radiographic diagnosis to be separated from discospondylitis: a preliminary report

International Nuclear Information System (INIS)

Jimenez, M.M.; O'Callaghan, M.W.

1995-01-01

A retrospective study was initiated to investigate the incidence, radiographic appearance and progression of vertebral physitis, a condition the authors propose as a separate radiographic diagnosis from discospondylitis. From 30 dogs with an initial radiographic diagnosis of discospondylitis, six dogs (five less than two years old) had radiographic signs believed to represent vertebral physitis. Bone lysis initially confined to the caudal physeal zone of affected vertebrae and sparing the vertebral endplates characterized the vertebral physitis lesions. Subsequent collapse of the caudoventral vertebral body and reactive spondylosis arising only from the caudal vertebral margins followed as the lesions progressed. By contrast, discospondylitis lesions originated as symmetric lysis of the vertebral endplates with reactive sclerosis in both vertebral bodies, and subsequent symmetric spondylosis. As a result of the differing radiographic patterns demonstrated by the physitis and discospondylitis lesions the author's also propose an alternative pathogenesis from that which is generally accepted for discospondylitis

Regulator of G-protein signaling - 5 (RGS5 is a novel repressor of hedgehog signaling.

Directory of Open Access Journals (Sweden)

William M Mahoney

Full Text Available Hedgehog (Hh signaling plays fundamental roles in morphogenesis, tissue repair, and human disease. Initiation of Hh signaling is controlled by the interaction of two multipass membrane proteins, patched (Ptc and smoothened (Smo. Recent studies identify Smo as a G-protein coupled receptor (GPCR-like protein that signals through large G-protein complexes which contain the Gαi subunit. We hypothesize Regulator of G-Protein Signaling (RGS proteins, and specifically RGS5, are endogenous repressors of Hh signaling via their ability to act as GTPase activating proteins (GAPs for GTP-bound Gαi, downstream of Smo. In support of this hypothesis, we demonstrate that RGS5 over-expression inhibits sonic hedgehog (Shh-mediated signaling and osteogenesis in C3H10T1/2 cells. Conversely, signaling is potentiated by siRNA-mediated knock-down of RGS5 expression, but not RGS4 expression. Furthermore, using immuohistochemical analysis and co-immunoprecipitation (Co-IP, we demonstrate that RGS5 is present with Smo in primary cilia. This organelle is required for canonical Hh signaling in mammalian cells, and RGS5 is found in a physical complex with Smo in these cells. We therefore conclude that RGS5 is an endogenous regulator of Hh-mediated signaling and that RGS proteins are potential targets for novel therapeutics in Hh-mediated diseases.

Studies on signal validation and sensor surveillance for in-core signals in NPP

International Nuclear Information System (INIS)

Ciftcioglu, O.

1991-12-01

Signal validation and sensor failure detection are two essential tasks to be carried out continuously in an operating reactor. Towards this aim, an optimal filtering approach for in-core NPP signals is implemented. The method concerns the specific measured input signal information as a parameter state and they are estimated by means of Kalman filtering technique. The signal validation and sensor surveillance system comprise filters as many as the states being considered and each filter receives all the measured signals as inputs in such a way that each filter in hand is desensitized to one of the individual input signals relative to others. In case of no failure of sensors all the filter outputs are identical. Each sensor output is tested by means of corresponding estimate present at the output of that filter which is desensitized to the sensor being tested. The comparison test is carried out continuously in real-time and any significant deviation noted during the test process is identified to be a sensor failure together with the faulty sensor. The method is investigated by means of real plant data of the in-core neutron detectors and core-inlet and outlet thermocouples of the Borssele nuclear power plant. The method has proven to be effective for fast and reliable in-core sensor failure detection as well as for in-core signal validation in normal operation indicating its further effectiveness for model validation applications in nuclear power plants. (author). 17 refs.; 4 figs.; 1 tab

Cellular signalling properties in microcircuits

DEFF Research Database (Denmark)

Toledo-Rodriguez, Maria; El Manira, Abdeljabbar; Wallén, Peter

2005-01-01

Molecules and cells are the signalling elements in microcircuits. Recent studies have uncovered bewildering diversity in postsynaptic signalling properties in all areas of the vertebrate nervous system. Major effort is now being invested in establishing the specialized signalling properties...

Ghost signals in Allison emittance scanners

International Nuclear Information System (INIS)

Stockli, Martin P.; Leitner, M.; Moehs, D.P.; Keller, R.; Welton, R.F.

2004-01-01

For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

Ghost Signals In Allison Emittance Scanners

International Nuclear Information System (INIS)

Stockli, Martin P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R. F.

2005-01-01

For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

Signal recovery of the corrupted metal impact signal using the adaptive filtering in NPPs

International Nuclear Information System (INIS)

Kim, Dai Il; Shin, Won Ky; Oh, Sung Hun; Yun, Won Young

1995-01-01

Loose Part Monitoring System (LPMS) is one of the fundamental diagnostic tools installed in the nuclear power plants. In this paper, recovery process algorithm and model for the corrupted impact signal generated by loose parts is presented. The characteristics of this algorithm can obtain a proper burst signal even though background noise is considerably high level comparing with actual impact signal. To verify performance of the proposed algorithm, we evaluate mathematically signal-to-noise ratio of primary output and noise. The performance of this recovery process algorithm is shown through computer simulation

An electrophysiological study on the effects of Pa-1G (a phospholipase A(2)) from the venom of king brown snake, Pseudechis australis, on neuromuscular function.

Science.gov (United States)

Fatehi, M; Rowan, E G; Harvey, A L

2002-01-01

The effects of Pa-1G, a phospholipase A(2) (PLA(2)) from the venom of the Australian king brown snake (Pseudechis australis) were determined on the release of acetylcholine, muscle resting membrane potential and motor nerve terminal action potential at mouse neuromuscular junction. Intracellular recording from endplate regions of mouse triangularis sterni nerve-muscle preparations revealed that Pa-1G (800 nM) significantly reduced the amplitude of endplate potentials within 10 min exposure. The quantal content of endplate potentials was decreased to 58+/-6% of control after 30 min exposure to 800 nM Pa-1G. The toxin also caused a partial depolarisation of mouse muscle fibres within 60 min exposure. Extracellular recording of action potentials at motor nerve terminals showed that Pa-1G reduced the waveforms associated with both sodium and potassium conductances. To investigate whether this was a direct or indirect effect of the toxin on these ionic currents, whole cell patch clamp experiments were performed using human neuroblastoma (SK-N-SH) cells and B82 mouse fibroblasts stably transfected with rKv1.2. Patch clamp recording experiments confirmed that potassium currents sensitive to alpha-dendrotoxin recorded from B82 cells and sodium currents in SK-N-SH cells were not affected by the toxin. Since neither facilitation of acetylcholine release at mouse neuromuscular junction nor depression of potassium currents in B82 cells has been observed, the apparent blockade of potassium currents at mouse motor nerve endings induced by the toxin is unlikely to be due to a selective block of potassium channels.

VARIABILITY OF MANUAL AND COMPUTERIZED METHODS FOR MEASURING CORONAL VERTEBRAL INCLINATION IN COMPUTED TOMOGRAPHY IMAGES

Directory of Open Access Journals (Sweden)

Tomaž Vrtovec

2015-06-01

Full Text Available Objective measurement of coronal vertebral inclination (CVI is of significant importance for evaluating spinal deformities in the coronal plane. The purpose of this study is to systematically analyze and compare manual and computerized measurements of CVI in cross-sectional and volumetric computed tomography (CT images. Three observers independently measured CVI in 14 CT images of normal and 14 CT images of scoliotic vertebrae by using six manual and two computerized measurements. Manual measurements were obtained in coronal cross-sections by manually identifying the vertebral body corners, which served to measure CVI according to the superior and inferior tangents, left and right tangents, and mid-endplate and mid-wall lines. Computerized measurements were obtained in two dimensions (2D and in three dimensions (3D by manually initializing an automated method in vertebral centroids and then searching for the planes of maximal symmetry of vertebral anatomical structures. The mid-endplate lines were the most reproducible and reliable manual measurements (intra- and inter-observer variability of 0.7° and 1.2° standard deviation, SD, respectively. The computerized measurements in 3D were more reproducible and reliable (intra- and inter-observer variability of 0.5° and 0.7° SD, respectively, but were most consistent with the mid-wall lines (2.0° SD and 1.4° mean absolute difference. The manual CVI measurements based on mid-endplate lines and the computerized CVI measurements in 3D resulted in the lowest intra-observer and inter-observer variability, however, computerized CVI measurements reduce observer interaction.

Ultrahigh bandwidth signal processing

DEFF Research Database (Denmark)

Oxenløwe, Leif Katsuo

2016-01-01

Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

Wireless data signal transmission system

DEFF Research Database (Denmark)

2014-01-01

The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver.......The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver....

Semi-classical signal analysis

KAUST Repository

Laleg-Kirati, Taous-Meriem

2012-09-30

This study introduces a new signal analysis method, based on a semi-classical approach. The main idea in this method is to interpret a pulse-shaped signal as a potential of a Schrödinger operator and then to use the discrete spectrum of this operator for the analysis of the signal. We present some numerical examples and the first results obtained with this method on the analysis of arterial blood pressure waveforms. © 2012 Springer-Verlag London Limited.

Astrocyte Sodium Signalling and Panglial Spread of Sodium Signals in Brain White Matter.

Science.gov (United States)

Moshrefi-Ravasdjani, Behrouz; Hammel, Evelyn L; Kafitz, Karl W; Rose, Christine R

2017-09-01

In brain grey matter, excitatory synaptic transmission activates glutamate uptake into astrocytes, inducing sodium signals which propagate into neighboring astrocytes through gap junctions. These sodium signals have been suggested to serve an important role in neuro-metabolic coupling. So far, it is unknown if astrocytes in white matter-that is in brain regions devoid of synapses-are also able to undergo such intra- and intercellular sodium signalling. In the present study, we have addressed this question by performing quantitative sodium imaging in acute tissue slices of mouse corpus callosum. Focal application of glutamate induced sodium transients in SR101-positive astrocytes. These were largely unaltered in the presence of ionotropic glutamate receptors blockers, but strongly dampened upon pharmacological inhibition of glutamate uptake. Sodium signals induced in individual astrocytes readily spread into neighboring SR101-positive cells with peak amplitudes decaying monoexponentially with distance from the stimulated cell. In addition, spread of sodium was largely unaltered during pharmacological inhibition of purinergic and glutamate receptors, indicating gap junction-mediated, passive diffusion of sodium between astrocytes. Using cell-type-specific, transgenic reporter mice, we found that sodium signals also propagated, albeit less effectively, from astrocytes to neighboring oligodendrocytes and NG2 cells. Again, panglial spread was unaltered with purinergic and glutamate receptors blocked. Taken together, our results demonstrate that activation of sodium-dependent glutamate transporters induces sodium signals in white matter astrocytes, which spread within the astrocyte syncytium. In addition, we found a panglial passage of sodium signals from astrocytes to NG2 cells and oligodendrocytes, indicating functional coupling between these macroglial cells in white matter.

Resting release of acetylcholine at the motor endplate

International Nuclear Information System (INIS)

Molenaar, P.C.; Polak, R.L.

1986-01-01

This paper reviews recent work on resting release of ACh in frog, rat and mouse skeletal muscle. Because of the effect of Ca 2+ on resting release it was of interest to know whether non-quantal release of ACh is increased under conditions of increased Ca 2+ influx, viz. during depolarization of the nerve terminals. It is shown that depolarization of the motor nerve terminals by K + ions led to an increase of both min.e.p.c. frequency and chemically detectable ACh release

Signaling equilibria in sensorimotor interactions.

Science.gov (United States)

Leibfried, Felix; Grau-Moya, Jordi; Braun, Daniel A

2015-08-01

Although complex forms of communication like human language are often assumed to have evolved out of more simple forms of sensorimotor signaling, less attention has been devoted to investigate the latter. Here, we study communicative sensorimotor behavior of humans in a two-person joint motor task where each player controls one dimension of a planar motion. We designed this joint task as a game where one player (the sender) possesses private information about a hidden target the other player (the receiver) wants to know about, and where the sender's actions are costly signals that influence the receiver's control strategy. We developed a game-theoretic model within the framework of signaling games to investigate whether subjects' behavior could be adequately described by the corresponding equilibrium solutions. The model predicts both separating and pooling equilibria, in which signaling does and does not occur respectively. We observed both kinds of equilibria in subjects and found that, in line with model predictions, the propensity of signaling decreased with increasing signaling costs and decreasing uncertainty on the part of the receiver. Our study demonstrates that signaling games, which have previously been applied to economic decision-making and animal communication, provide a framework for human signaling behavior arising during sensorimotor interactions in continuous and dynamic environments. Copyright © 2015 Elsevier B.V. All rights reserved.

Redox signaling in plants.

Science.gov (United States)

Foyer, Christine H; Noctor, Graham

2013-06-01

Our aim is to deliver an authoritative and challenging perspective of current concepts in plant redox signaling, focusing particularly on the complex interface between the redox and hormone-signaling pathways that allow precise control of plant growth and defense in response to metabolic triggers and environmental constraints and cues. Plants produce significant amounts of singlet oxygen and other reactive oxygen species (ROS) as a result of photosynthetic electron transport and metabolism. Such pathways contribute to the compartment-specific redox-regulated signaling systems in plant cells that convey information to the nucleus to regulate gene expression. Like the chloroplasts and mitochondria, the apoplast-cell wall compartment makes a significant contribution to the redox signaling network, but unlike these organelles, the apoplast has a low antioxidant-buffering capacity. The respective roles of ROS, low-molecular antioxidants, redox-active proteins, and antioxidant enzymes are considered in relation to the functions of plant hormones such as salicylic acid, jasmonic acid, and auxin, in the composite control of plant growth and defense. Regulation of redox gradients between key compartments in plant cells such as those across the plasma membrane facilitates flexible and multiple faceted opportunities for redox signaling that spans the intracellular and extracellular environments. In conclusion, plants are recognized as masters of the art of redox regulation that use oxidants and antioxidants as flexible integrators of signals from metabolism and the environment.

Signals and Systems in Biomedical Engineering Signal Processing and Physiological Systems Modeling

CERN Document Server

Devasahayam, Suresh R

2013-01-01

The use of digital signal processing is ubiquitous in the field of physiology and biomedical engineering. The application of such mathematical and computational tools requires a formal or explicit understanding of physiology. Formal models and analytical techniques are interlinked in physiology as in any other field. This book takes a unitary approach to physiological systems, beginning with signal measurement and acquisition, followed by signal processing, linear systems modelling, and computer simulations. The signal processing techniques range across filtering, spectral analysis and wavelet analysis. Emphasis is placed on fundamental understanding of the concepts as well as solving numerical problems. Graphs and analogies are used extensively to supplement the mathematics. Detailed models of nerve and muscle at the cellular and systemic levels provide examples for the mathematical methods and computer simulations. Several of the models are sufficiently sophisticated to be of value in understanding real wor...

Wnt/beta-catenin signaling interacts differentially with Ihh signaling in controlling endochondral bone and synovial joint formation.

Science.gov (United States)

Mak, Kingston Kinglun; Chen, Miao-Hsueh; Day, Timothy F; Chuang, Pao-Tien; Yang, Yingzi

2006-09-01

Both the Wnt/beta-catenin and Ihh signaling pathways play essential roles in crucial aspects of endochondral ossification: osteoblast differentiation, chondrocyte proliferation and hypertrophy. To understand the genetic interaction between these two signaling pathways, we have inactivated the beta-catenin gene and upregulated Ihh signaling simultaneously in the same cells during endochondral skeletal development using beta-catenin and patched 1 floxed alleles. We uncovered previously unexpected roles of Ihh signaling in synovial joint formation and the essential function of Wnt/beta-catenin signaling in regulating chondrocyte survival. More importantly, we found that Wnt and Ihh signaling interact with each other in distinct ways to control osteoblast differentiation, chondrocyte proliferation, hypertrophy, survival and synovial joint formation in the developing endochondral bone. Beta-catenin is required downstream of Ihh signaling and osterix expression for osteoblast differentiation. But in chondrocyte survival, beta-catenin is required upstream of Ihh signaling to inhibit chondrocyte apoptosis. In addition, Ihh signaling can inhibit chondrocyte hypertrophy and synovial joint formation independently of beta-catenin. However, there is a strong synergistic interaction between Wnt/beta-catenin and Ihh signaling in regulating synovial joint formation.

Zufällige Signale

Science.gov (United States)

Plaßmann, Wilfried

Die hier betrachteten Signale werden auch als stochastische Signale bezeichnet. Sie sind zufällig, d. h. ihr Augenblickswert ist nicht vorhersagbar. Abb. 118.1 zeigt eine Unterteilung nach den Signaleigenschaften. Über die nichtstationären Signale lässt sich keinerlei Aussage machen, und sie werden hier deshalb auch nicht weiter betrachtet. Für die stationären Signale gilt, dass ihr Momentanwert zwar auch nicht vorhergesagt werden kann, dass sie aber trotzdem gewisse auswertbare Eigenschaften besitzen, die allerdings statistischer Art sind und deshalb nur mit den Gesetzen der Wahrscheinlichkeitstheorie erfasst werden können. Zwar sind - theoretisch - für die Anwendung der Wahrscheinlichkeitstheorie unendlich viele Probenwerte zu nehmen, in der Praxis hat sich aber gezeigt, dass man auch mit einer endlichen Anzahl dem gesuchten Wert schon ausreichend nahe kommen kann.

Signalling crosstalk in plants: emerging issues.

Science.gov (United States)

Taylor, Jane E; McAinsh, Martin R

2004-01-01

The Oxford English Dictionary defines crosstalk as 'unwanted transfer of signals between communication channels'. How does this definition relate to the way in which we view the organization and function of signalling pathways? Recent advances in the field of plant signalling have challenged the traditional view of a signalling transduction cascade as isolated linear pathways. Instead the picture emerging of the mechanisms by which plants transduce environmental signals is of the interaction between transduction chains. The manner in which these interactions occur (and indeed whether the transfer of these signals is 'unwanted' or beneficial) is currently the topic of intense research.

Thermal resonance in signal transmission

International Nuclear Information System (INIS)

Reigada, Ramon; Sarmiento, Antonio; Lindenberg, Katja

2001-01-01

We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance observed in arrays of bistable systems

Thermal resonance in signal transmission

Energy Technology Data Exchange (ETDEWEB)

Reigada, Ramon; Sarmiento, Antonio; Lindenberg, Katja

2001-06-01

We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance observed in arrays of bistable systems.

Aberrant Signaling Pathways in Glioma

International Nuclear Information System (INIS)

Nakada, Mitsutoshi; Kita, Daisuke; Watanabe, Takuya; Hayashi, Yutaka; Teng, Lei; Pyko, Ilya V.; Hamada, Jun-Ichiro

2011-01-01

Glioblastoma multiforme (GBM), a WHO grade IV malignant glioma, is the most common and lethal primary brain tumor in adults; few treatments are available. Median survival rates range from 12–15 months. The biological characteristics of this tumor are exemplified by prominent proliferation, active invasiveness, and rich angiogenesis. This is mainly due to highly deregulated signaling pathways in the tumor. Studies of these signaling pathways have greatly increased our understanding of the biology and clinical behavior of GBM. An integrated view of signal transduction will provide a more useful approach in designing novel therapies for this devastating disease. In this review, we summarize the current understanding of GBM signaling pathways with a focus on potential molecular targets for anti-signaling molecular therapies

Predicting Secretory Proteins with SignalP

DEFF Research Database (Denmark)

Nielsen, Henrik

2017-01-01

SignalP is the currently most widely used program for prediction of signal peptides from amino acid sequences. Proteins with signal peptides are targeted to the secretory pathway, but are not necessarily secreted. After a brief introduction to the biology of signal peptides and the history...

Signals and systems laboratory with Matlab

CERN Document Server

Palamides, Alex

2010-01-01

Introduction to MATLAB®Working EnvironmentGetting StartedMemory ManagementVectorsMatricesPlotting with MATLABComplex NumbersM-FilesInput-Output CommandsFile ManagementLogical-Relational OperatorsControl FlowSymbolic VariablesPolynomials(Pseudo)Random NumbersSignalsCategorization by the Variable TypeBasic Continuous-Time SignalsDiscrete-Time SignalsProperties of SignalsTransformations of the Time Variable for Continuous-Time SignalsTransformations of the Time Variable for Discrete-Time SignalsSystemsSystems ClassificationProperties of SystemsTime Domain System AnalysisImpulse ResponseContinuous Time Convolution Convolution PropertiesInterconnections of SystemsStabilityDiscrete-Time ConvolutionSystems Described by Difference EquationsFiltersStability Criterion for Discrete-Time SystemsSystems Described by Differential EquationsStep Response of a SystemFourier SeriesOrthogonality of Complex Exponential SignalsComplex Exponential Fourier SeriesTrigonometric Fourier SeriesFourier Series in the Cosine with Phase F...

Guard Cell Signal Transduction Network: Advances in Understanding Abscisic Acid, CO2, and Ca2+ Signaling

KAUST Repository

Kim, Tae-Houn

2010-05-04

Stomatal pores are formed by pairs of specialized epidermal guard cells and serve as major gateways for both CO2 influx into plants from the atmosphere and transpirational water loss of plants. Because they regulate stomatal pore apertures via integration of both endogenous hormonal stimuli and environmental signals, guard cells have been highly developed as a model system to dissect the dynamics and mechanisms of plant-cell signaling. The stress hormone ABA and elevated levels of CO2 activate complex signaling pathways in guard cells that are mediated by kinases/phosphatases, secondary messengers, and ion channel regulation. Recent research in guard cells has led to a new hypothesis for how plants achieve specificity in intracellular calcium signaling: CO2 and ABA enhance (prime) the calcium sensitivity of downstream calcium-signaling mechanisms. Recent progress in identification of early stomatal signaling components are reviewed here, including ABA receptors and CO2-binding response proteins, as well as systems approaches that advance our understanding of guard cell-signaling mechanisms.

Guard Cell Signal Transduction Network: Advances in Understanding Abscisic Acid, CO2, and Ca2+ Signaling

KAUST Repository

Kim, Tae-Houn; Bö hmer, Maik; Hu, Honghong; Nishimura, Noriyuki; Schroeder, Julian I.

2010-01-01

Stomatal pores are formed by pairs of specialized epidermal guard cells and serve as major gateways for both CO2 influx into plants from the atmosphere and transpirational water loss of plants. Because they regulate stomatal pore apertures via integration of both endogenous hormonal stimuli and environmental signals, guard cells have been highly developed as a model system to dissect the dynamics and mechanisms of plant-cell signaling. The stress hormone ABA and elevated levels of CO2 activate complex signaling pathways in guard cells that are mediated by kinases/phosphatases, secondary messengers, and ion channel regulation. Recent research in guard cells has led to a new hypothesis for how plants achieve specificity in intracellular calcium signaling: CO2 and ABA enhance (prime) the calcium sensitivity of downstream calcium-signaling mechanisms. Recent progress in identification of early stomatal signaling components are reviewed here, including ABA receptors and CO2-binding response proteins, as well as systems approaches that advance our understanding of guard cell-signaling mechanisms.

Generation and coherent detection of QPSK signal using a novel method of digital signal processing

Science.gov (United States)

Zhao, Yuan; Hu, Bingliang; He, Zhen-An; Xie, Wenjia; Gao, Xiaohui

2018-02-01

We demonstrate an optical quadrature phase-shift keying (QPSK) signal transmitter and an optical receiver for demodulating optical QPSK signal with homodyne detection and digital signal processing (DSP). DSP on the homodyne detection scheme is employed without locking the phase of the local oscillator (LO). In this paper, we present an extracting one-dimensional array of down-sampling method for reducing unwanted samples of constellation diagram measurement. Such a novel scheme embodies the following major advantages over the other conventional optical QPSK signal detection methods. First, this homodyne detection scheme does not need strict requirement on LO in comparison with linear optical sampling, such as having a flat spectral density and phase over the spectral support of the source under test. Second, the LabVIEW software is directly used for recovering the QPSK signal constellation without employing complex DSP circuit. Third, this scheme is applicable to multilevel modulation formats such as M-ary PSK and quadrature amplitude modulation (QAM) or higher speed signals by making minor changes.

On-line signal trend identification

International Nuclear Information System (INIS)

Tambouratzis, T.; Antonopoulos-Domis, M.

2004-01-01

An artificial neural network, based on the self-organizing map, is proposed for on-line signal trend identification. Trends are categorized at each incoming signal as steady-state, increasing and decreasing, while they are further classified according to characteristics such signal shape and rate of change. Tests with model-generated signals illustrate the ability of the self-organizing map to accurately and reliably perform on-line trend identification in terms of both detection and classification. The proposed methodology has been found robust to the presence of white noise

Signal generation in gas detectors

International Nuclear Information System (INIS)

Stillman, A.

1993-01-01

This tutorial describes the generation of electrical signals in gas detectors. Ionization of the gas by the passage of charged particles generates these signals. Starting with the Bethe-Bloch equation, the treatment is a general introduction to the production of ion-pairs in gas devices. I continue with the characterization of the ionization as an electrical signal, and calculate the signal current in a simple example. Another example demonstrates the effect of space charge on the design of a detector. The AGS Booster ionization profile monitor is a model for this calculation

Foundations of signal processing

CERN Document Server

Vetterli, Martin; Goyal, Vivek K

2014-01-01

This comprehensive and engaging textbook introduces the basic principles and techniques of signal processing, from the fundamental ideas of signals and systems theory to real-world applications. Students are introduced to the powerful foundations of modern signal processing, including the basic geometry of Hilbert space, the mathematics of Fourier transforms, and essentials of sampling, interpolation, approximation and compression. The authors discuss real-world issues and hurdles to using these tools, and ways of adapting them to overcome problems of finiteness and localisation, the limitations of uncertainty and computational costs. Standard engineering notation is used throughout, making mathematical examples easy for students to follow, understand and apply. It includes over 150 homework problems and over 180 worked examples, specifically designed to test and expand students' understanding of the fundamentals of signal processing, and is accompanied by extensive online materials designed to aid learning, ...

Signal-to-Signal Ratio Independent Speaker Identification for Co-channel Speech Signals

DEFF Research Database (Denmark)

Saeidi, Rahim; Mowlaee, Pejman; Kinnunen, Tomi

2010-01-01

In this paper, we consider speaker identification for the co-channel scenario in which speech mixture from speakers is recorded by one microphone only. The goal is to identify both of the speakers from their mixed signal. High recognition accuracies have already been reported when an accurately...

Properties of light induced EPR signals in enamel and their possible interference with gamma-induced signals

International Nuclear Information System (INIS)

Sholom, S.V.; Chumak, V.V.; Haskell, E.H.; Hayes, R.B.; Kenner, G.H.

1998-01-01

Exposure of tooth enamel to natural and artificial UV light results in stable EPR signals with g-factors of 1.9985, 2.0018, 2.0045, 2.0052 and 2.0110. The first three signals correspond to the parallel and perpendicular components of the radiation induced or dosimetric signal and the native signal reported in dosimetry and dating studies. The latter two signals were found to be sensitive to both gamma-ray and sunlight exposure, however, their responses to light differed from that to radiation, giving rise to the possibility of using them as indicators of the dose-equivalent resulting from light exposure

On viscoelastic instability in polymeric filaments

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Hassager, Ole

1999-01-01

The 3D Lagrangian Integral Method is used to simulate the effects of surface tension on the viscoelastic end-plate instability, occuring in the rapid extension of some polymeric filaments between parallel plates. It is shovn that the surface tension delays the onset of the instability. Furthermore...

Instability in the Peeling of a Polymeric Filament from a Rigid Surface

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Hassager, Ole

2000-01-01

The 3D Lagrangian integral method is used to simulate the effects of the rheology on the viscoelastic end-plate instability, occuring in the rapid extension of some polymeric filaments between parallel plates.It is shown that strain hardening materials with a negative second normal stress differe...

Lagrangian Finite Element Method for 3D Time-Dependent Viscoelastic Flow Computations using Integral Models

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz

2000-01-01

The 3D-LIM has as yet been used to simulate the following two three-dimensional problems. First, the method has been used to simulete for viscoelastic end-plate instability that occurs under certain conditions in the transient filament stretching apparatus for pressure sensitive adhesives (polyme...

Canonical Wnt signaling in diabetic retinopathy.

Science.gov (United States)

Chen, Qian; Ma, Jian-Xing

2017-10-01

Diabetic retinopathy (DR) is a common eye complication of diabetes, and the pathogenic mechanism of DR is still under investigation. The canonical Wnt signaling pathway is an evolutionarily conserved pathway that plays fundamental roles in embryogenesis and adult tissue homeostasis. Wnt signaling regulates expression of multiple genes that control retinal development and eye organogenesis, and dysregulated Wnt signaling plays pathophysiological roles in many ocular diseases, including DR. This review highlights recent progress in studies of Wnt signaling in DR. We discuss Wnt signaling regulation in the retina and dysregulation of Wnt signaling associated with ocular diseases with an emphasis on DR. We also discuss the therapeutic potential of modulating Wnt signaling in DR. Continued studies in this field will advance our current understanding on DR and contribute to the development of new treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolites in vertebrate Hedgehog signaling.

Science.gov (United States)

Roberg-Larsen, Hanne; Strand, Martin Frank; Krauss, Stefan; Wilson, Steven Ray

2014-04-11

The Hedgehog (HH) signaling pathway is critical in embryonic development, stem cell biology, tissue homeostasis, chemoattraction and synapse formation. Irregular HH signaling is associated with a number of disease conditions including congenital disorders and cancer. In particular, deregulation of HH signaling has been linked to skin, brain, lung, colon and pancreatic cancers. Key mediators of the HH signaling pathway are the 12-pass membrane protein Patched (PTC), the 7-pass membrane protein Smoothened (SMO) and the GLI transcription factors. PTC shares homology with the RND family of small-molecule transporters and it has been proposed that it interferes with SMO through metabolites. Although a conclusive picture is lacking, substantial efforts are made to identify and understand natural metabolites/sterols, including cholesterol, vitamin D3, oxysterols and glucocorticoides, that may be affected by, or influence the HH signaling cascade at the level of PTC and SMO. In this review we will elaborate the role of metabolites in HH signaling with a focus on oxysterols, and discuss advancements in modern analytical approaches in the field. Copyright © 2014 Elsevier Inc. All rights reserved.

Insulin Signaling and Heart Failure

Science.gov (United States)

Riehle, Christian; Abel, E. Dale

2016-01-01

Heart failure is associated with generalized insulin resistance. Moreover, insulin resistant states such as type 2 diabetes and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes alters the systemic and neurohumoral milieu leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead (FOXO) transcriptional signaling or glucose transport which may also impair cardiac metabolism, structure and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed. PMID:27034277

Prototype for the ALEPH Time Projection Chamber

CERN Multimedia

1980-01-01

This is a prototype endplate piece constructed during R&D for the ALEPH Time Projection Chamber (TPC). ALEPH was one of 4 experiments at CERN's 27km Large Electron Positron collider (LEP) that ran from 1989 to 2000. ALEPH's TPC was a large-volume tracking chamber, 4.4 metres long and 3.6 metres in diameter - the largest TPC in existance at the time. This object is one of the endplates of a “Kind” sector, the smallest of the three types of sectors. The patterns etched into the copper form the cathode pads that measured particle track coordinates in the r-phi direction. It included a laser calibration system, a gating system to prevent space charge buildup, and a new radial pad geometry to improve resolution. the ALEPH TPC allowed for precise momentum measurements of the high-momentum particles from W and Z decays. The following institutes participated: CERN, Athens, Glasgow, Mainz, MPI Munich, INFN-Pisa, INFN-Trieste, Wisconsin.

CANDU fuel bundle deformation modelling with COMSOL multiphysics

International Nuclear Information System (INIS)

Bell, J.S.; Lewis, B.J.

2012-01-01

Highlights: ► The deformation behaviour of a CANDU fuel bundle was modelled. ► The model has been developed on a commercial finite-element platform. ► Pellet/sheath interaction and end-plate restraint effects were considered. ► The model was benchmarked against the BOW code and a variable-load experiment. - Abstract: A model to describe deformation behaviour of a CANDU 37-element bundle has been developed under the COMSOL Multiphysics finite-element platform. Beam elements were applied to the fuel elements (composed of fuel sheaths and pellets) and endplates in order to calculate the bowing behaviour of the fuel elements. This model is important to help assess bundle-deformation phenomena, which may lead to more restrictive coolant flow through the sub-channels of the horizontally oriented bundle. The bundle model was compared to the BOW code for the occurrence of a dry-out patch, and benchmarked against an out-reactor experiment with a variable load on an outer fuel element.

Neurotransmitter signaling in white matter.

Science.gov (United States)

Butt, Arthur M; Fern, Robert F; Matute, Carlos

2014-11-01

White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function. © 2014 Wiley Periodicals, Inc.

Intracellular signal modulation by nanomaterials.

Science.gov (United States)

Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

2014-01-01

A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can be of crucial importance for the cytotoxicity of nanomaterials and membrane-dependent signaling pathways have also been shown to be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials, effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future.

Signal Processing and Neural Network Simulator

Science.gov (United States)

Tebbe, Dennis L.; Billhartz, Thomas J.; Doner, John R.; Kraft, Timothy T.

1995-04-01

The signal processing and neural network simulator (SPANNS) is a digital signal processing simulator with the capability to invoke neural networks into signal processing chains. This is a generic tool which will greatly facilitate the design and simulation of systems with embedded neural networks. The SPANNS is based on the Signal Processing WorkSystemTM (SPWTM), a commercial-off-the-shelf signal processing simulator. SPW provides a block diagram approach to constructing signal processing simulations. Neural network paradigms implemented in the SPANNS include Backpropagation, Kohonen Feature Map, Outstar, Fully Recurrent, Adaptive Resonance Theory 1, 2, & 3, and Brain State in a Box. The SPANNS was developed by integrating SAIC's Industrial Strength Neural Networks (ISNN) Software into SPW.

Blind I/Q Signal Separation-Based Solutions for Receiver Signal Processing

Directory of Open Access Journals (Sweden)

Visa Koivunen

2005-09-01

Full Text Available This paper introduces some novel digital signal processing (DSP-based approaches to some of the most fundamental tasks of radio receivers, namely, channel equalization, carrier synchronization, and I/Q mismatch compensation. The leading principle is to show that all these problems can be solved blindly (i.e., without training signals by forcing the I and Q components of the observed data as independent as possible. Blind signal separation (BSS is then introduced as an efficient tool to carry out these tasks, and simulation examples are used to illustrate the performance of the proposed approaches. The main application area of the presented carrier synchronization and I/Q mismatch compensation techniques is in direct-conversion type receivers, while the proposed channel equalization principles basically apply to any radio architecture.

Multiresolution signal decomposition schemes

NARCIS (Netherlands)

J. Goutsias (John); H.J.A.M. Heijmans (Henk)

1998-01-01

textabstract[PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis

Semi-classical signal analysis

KAUST Repository

Laleg-Kirati, Taous-Meriem; Cré peau, Emmanuelle; Sorine, Michel

2012-01-01

This study introduces a new signal analysis method, based on a semi-classical approach. The main idea in this method is to interpret a pulse-shaped signal as a potential of a Schrödinger operator and then to use the discrete spectrum

Optimal fault signal estimation

NARCIS (Netherlands)

Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.

2002-01-01

We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

Signal processing for radiation detectors

CERN Document Server

Nakhostin, Mohammad

2018-01-01

This book provides a clear understanding of the principles of signal processing of radiation detectors. It puts great emphasis on the characteristics of pulses from various types of detectors and offers a full overview on the basic concepts required to understand detector signal processing systems and pulse processing techniques. Signal Processing for Radiation Detectors covers all of the important aspects of signal processing, including energy spectroscopy, timing measurements, position-sensing, pulse-shape discrimination, and radiation intensity measurement. The book encompasses a wide range of applications so that readers from different disciplines can benefit from all of the information. In addition, this resource: * Describes both analog and digital techniques of signal processing * Presents a complete compilation of digital pulse processing algorithms * Extrapolates content from more than 700 references covering classic papers as well as those of today * Demonstrates concepts with more than 340 origin...

High-level expression of nattokinase in Bacillus licheniformis by manipulating signal peptide and signal peptidase.

Science.gov (United States)

Cai, D; Wei, X; Qiu, Y; Chen, Y; Chen, J; Wen, Z; Chen, S

2016-09-01

Nattokinase is an enzyme produced by Bacillus licheniformis and has potential to be used as a drug for treating cardiovascular disease due to its beneficial effects of preventing fibrin clots etc. However, the low activity and titre of this protein produced by B. licheniformis often hinders its application of commercial production. The aim of this work is to improve the nattokinase production by manipulating signal peptides and signal peptidases in B. licheniformis. The P43 promoter, amyL terminator and AprN target gene were used to form the nattokinase expression vector, pHY-SP-NK, which was transformed into B. licheniformis and nattokinase was expressed successfully. A library containing 81 predicted signal peptides was constructed for nattokinase expression in B. licheniformis, with the maximum activity being obtained under the signal peptide of AprE. Among four type I signal peptidases genes (sipS, sipT, sipV, sipW) in B. licheniformis, the deletion of sipV resulted in a highest decrease in nattokinase activity. Overexpression of sipV in B. licheniformis led to a nattokinase activity of 35·60 FU ml(-1) , a 4·68-fold improvement over activity produced by the initial strain. This work demonstrates the potential of B. licheniformis for industrial production of nattokinase through manipulation of signal peptides and signal peptidases expression. This study has screened the signal peptides of extracellular proteins of B. licheniformis for nattokinase production. Four kinds of Type I signal peptidases genes have been detected respectively in B. licheniformis to identify which one played the vital role for nattokinase production. This study provided a promising strain for industry production of nattokinase. © 2016 The Society for Applied Microbiology.

Calcium signalling silencing in atrial fibrillation.

Science.gov (United States)

Greiser, Maura

2017-06-15

Subcellular calcium signalling silencing is a novel and distinct cellular and molecular adaptive response to rapid cardiac activation. Calcium signalling silencing develops during short-term sustained rapid atrial activation as seen clinically during paroxysmal atrial fibrillation (AF). It is the first 'anti-arrhythmic' adaptive response in the setting of AF and appears to counteract the maladaptive changes that lead to intracellular Ca 2+ signalling instability and Ca 2+ -based arrhythmogenicity. Calcium signalling silencing results in a failed propagation of the [Ca 2+ ] i signal to the myocyte centre both in patients with AF and in a rabbit model. This adaptive mechanism leads to a substantial reduction in the expression levels of calcium release channels (ryanodine receptors, RyR2) in the sarcoplasmic reticulum, and the frequency of Ca 2+ sparks and arrhythmogenic Ca 2+ waves remains low. Less Ca 2+ release per [Ca 2+ ] i transient, increased fast Ca 2+ buffering strength, shortened action potentials and reduced L-type Ca 2+ current contribute to a substantial reduction of intracellular [Na + ]. These features of Ca 2+ signalling silencing are distinct and in contrast to the changes attributed to Ca 2+ -based arrhythmogenicity. Some features of Ca 2+ signalling silencing prevail in human AF suggesting that the Ca 2+ signalling 'phenotype' in AF is a sum of Ca 2+ stabilizing (Ca 2+ signalling silencing) and Ca 2+ destabilizing (arrhythmogenic unstable Ca 2+ signalling) factors. Calcium signalling silencing is a part of the mechanisms that contribute to the natural progression of AF and may limit the role of Ca 2+ -based arrhythmogenicity after the onset of AF. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Signal trend identification with fuzzy methods

International Nuclear Information System (INIS)

Reifman, J.; Tsoukalas, L. H.; Wang, X.; Wei, T. Y. C.

1999-01-01

A fuzzy-logic-based methodology for on-line signal trend identification is introduced. Although signal trend identification is complicated by the presence of noise, fuzzy logic can help capture important features of on-line signals and classify incoming power plant signals into increasing, decreasing and steady-state trend categories. In order to verify the methodology, a code named PROTREN is developed and tested using plant data. The results indicate that the code is capable of detecting transients accurately, identifying trends reliably, and not misinterpreting a steady-state signal as a transient one

PKD signaling and pancreatitis

Science.gov (United States)

Yuan, Jingzhen; Pandol, Stephen J.

2016-01-01

Background Acute pancreatitis is a serious medical disorder with no current therapies directed to the molecular pathogenesis of the disorder. Inflammation, inappropriate intracellular activation of digestive enzymes, and parenchymal acinar cell death by necrosis are the critical pathophysiologic processes of acute pancreatitis. Thus, it is necessary to elucidate the key molecular signals that mediate these pathobiologic processes and develop new therapeutic strategies to attenuate the appropriate signaling pathways in order to improve outcomes for this disease. A novel serine/threonine protein kinase D (PKD) family has emerged as key participants in signal transduction, and this family is increasingly being implicated in the regulation of multiple cellular functions and diseases. Methods This review summarizes recent findings of our group and others regarding the signaling pathway and the biological roles of the PKD family in pancreatic acinar cells. In particular, we highlight our studies of the functions of PKD in several key pathobiologic processes associated with acute pancreatitis in experimental models. Results Our findings reveal that PKD signaling is required for NF-κB activation/inflammation, intracellular zymogen activation, and acinar cell necrosis in rodent experimental pancreatitis. Novel small-molecule PKD inhibitors attenuate the severity of pancreatitis in both in vitro and in vivo experimental models. Further, this review emphasizes our latest advances in the therapeutic application of PKD inhibitors to experimental pancreatitis after the initiation of pancreatitis. Conclusions These novel findings suggest that PKD signaling is a necessary modulator in key initiating pathobiologic processes of pancreatitis, and that it constitutes a novel therapeutic target for treatments of this disorder. PMID:26879861

47 CFR 69.125 - Dedicated signalling transport.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Dedicated signalling transport. 69.125 Section... (CONTINUED) ACCESS CHARGES Computation of Charges § 69.125 Dedicated signalling transport. (a) Dedicated signalling transport shall consist of two elements, a signalling link charge and a signalling transfer point...

Ubiquitination in apoptosis signaling

NARCIS (Netherlands)

van de Kooij, L.W.

2014-01-01

The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

Design principles of nuclear receptor signaling: how complex networking improves signal transduction

Science.gov (United States)

Kolodkin, Alexey N; Bruggeman, Frank J; Plant, Nick; Moné, Martijn J; Bakker, Barbara M; Campbell, Moray J; van Leeuwen, Johannes P T M; Carlberg, Carsten; Snoep, Jacky L; Westerhoff, Hans V

2010-01-01

The topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of ‘design' aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic models of increasing complexity, calculations show how these features correspond to potentially important design principles, e.g.: (i) cytosolic ‘nuclear' receptor may shuttle signal molecules to the nucleus, (ii) the active export of NRs may ensure that there is sufficient receptor protein to capture ligand at the cytoplasmic membrane, (iii) a three conveyor belts design dissipating GTP-free energy, greatly aids response, (iv) the active export of importins may prevent sequestration of NRs by importins in the nucleus and (v) the unspecific nature of the nuclear pore may ensure signal-flux robustness. In addition, the models developed are suitable for implementation in specific cases of NR-mediated signaling, to predict individual receptor functions and differential sensitivity toward physiological and pharmacological ligands. PMID:21179018

Ultrasonic correlator versus signal averager as a signal to noise enhancement instrument

Science.gov (United States)

Kishoni, Doron; Pietsch, Benjamin E.

1989-01-01

Ultrasonic inspection of thick and attenuating materials is hampered by the reduced amplitudes of the propagated waves to a degree that the noise is too high to enable meaningful interpretation of the data. In order to overcome the low Signal to Noise (S/N) ratio, a correlation technique has been developed. In this method, a continuous pseudo-random pattern generated digitally is transmitted and detected by piezoelectric transducers. A correlation is performed in the instrument between the received signal and a variable delayed image of the transmitted one. The result is shown to be proportional to the impulse response of the investigated material, analogous to a signal received from a pulsed system, with an improved S/N ratio. The degree of S/N enhancement depends on the sweep rate. This paper describes the correlator, and compares it to the method of enhancing S/N ratio by averaging the signals. The similarities and differences between the two are highlighted and the potential advantage of the correlator system is explained.

Novel ultra-wideband photonic signal generation and transmission featuring digital signal processing bit error rate measurements

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal.......We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal....

A novel signal compression method based on optimal ensemble empirical mode decomposition for bearing vibration signals

Science.gov (United States)

Guo, Wei; Tse, Peter W.

2013-01-01

Today, remote machine condition monitoring is popular due to the continuous advancement in wireless communication. Bearing is the most frequently and easily failed component in many rotating machines. To accurately identify the type of bearing fault, large amounts of vibration data need to be collected. However, the volume of transmitted data cannot be too high because the bandwidth of wireless communication is limited. To solve this problem, the data are usually compressed before transmitting to a remote maintenance center. This paper proposes a novel signal compression method that can substantially reduce the amount of data that need to be transmitted without sacrificing the accuracy of fault identification. The proposed signal compression method is based on ensemble empirical mode decomposition (EEMD), which is an effective method for adaptively decomposing the vibration signal into different bands of signal components, termed intrinsic mode functions (IMFs). An optimization method was designed to automatically select appropriate EEMD parameters for the analyzed signal, and in particular to select the appropriate level of the added white noise in the EEMD method. An index termed the relative root-mean-square error was used to evaluate the decomposition performances under different noise levels to find the optimal level. After applying the optimal EEMD method to a vibration signal, the IMF relating to the bearing fault can be extracted from the original vibration signal. Compressing this signal component obtains a much smaller proportion of data samples to be retained for transmission and further reconstruction. The proposed compression method were also compared with the popular wavelet compression method. Experimental results demonstrate that the optimization of EEMD parameters can automatically find appropriate EEMD parameters for the analyzed signals, and the IMF-based compression method provides a higher compression ratio, while retaining the bearing defect

Signals structural analysis and processing: application to acoustic signals recorded during sodium boiling in a nuclear reactor

International Nuclear Information System (INIS)

Rodriguez, J.

1986-02-01

An acoustic system that uses examples to learn the structure of specific signals linked to a corresponding class of physical phenomena, and classify an unknown signal (possibly with noise present) into one of the learned classes is presented. The first stage consists of smoothing the data. The signal is represented as a trace according to background and event. To learn the structures in each class, smoothed, segmented signals are used. For classification, three operations to modify the signal so that it perfectly verifies the model description are available [fr

Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

Directory of Open Access Journals (Sweden)

Silke Neumann

Full Text Available Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

Social knowledge and signals in primates.

Science.gov (United States)

Bergman, Thore J; Sheehan, Michael J

2013-07-01

Primates are notable for having a rich and detailed understanding of their social environment and there has been great interest in the evolution and function of social knowledge in primates. Indeed, primates have been shown to have impressive understandings of not only other group members but also the complex relationships among them. To be useful, however, social knowledge requires memories from previous encounters and observations about individual traits that are stable. Here, we argue that social systems or traits that make social knowledge more costly or less accurate will favor signals that either supplement or replace social knowledge. Thus, the relationship between signals and social knowledge can be complementary or antagonistic depending on the type of signal. Our goal in this review is to elucidate the relationships between signals and social knowledge in primates. We categorize signals into three types, each with different relationships to social knowledge. (1) Identity signals directly facilitate social knowledge, (2) current-state signals supplement information gained through social knowledge, and (3) badges of status replace social knowledge. Primates rely extensively on identity information, but it remains to be determined to what extent this is based on receiver perception of individual variation or senders using identity signals. Primates frequently utilize current-state signals including signals of intent to augment their interactions with familiar individuals. Badges of status are rare in primates, and the cases where they are used point to a functional and evolutionary trade-off between badges of status and social knowledge. However, the nature of this relationship needs further exploration. © 2012 Wiley Periodicals, Inc.

"Utilizing" signal detection theory.

Science.gov (United States)

Lynn, Spencer K; Barrett, Lisa Feldman

2014-09-01

What do inferring what a person is thinking or feeling, judging a defendant's guilt, and navigating a dimly lit room have in common? They involve perceptual uncertainty (e.g., a scowling face might indicate anger or concentration, for which different responses are appropriate) and behavioral risk (e.g., a cost to making the wrong response). Signal detection theory describes these types of decisions. In this tutorial, we show how incorporating the economic concept of utility allows signal detection theory to serve as a model of optimal decision making, going beyond its common use as an analytic method. This utility approach to signal detection theory clarifies otherwise enigmatic influences of perceptual uncertainty on measures of decision-making performance (accuracy and optimality) and on behavior (an inverse relationship between bias magnitude and sensitivity optimizes utility). A "utilized" signal detection theory offers the possibility of expanding the phenomena that can be understood within a decision-making framework. © The Author(s) 2014.

Evaluation of diagnostic thresholds dependability for tribologic signals received in the environment disturbed by vibroacoustic and functional signals

Directory of Open Access Journals (Sweden)

Lindstedt Paweł

2015-12-01

Full Text Available Determination of dependable diagnostic thresholds for tribologic signals received e.g. from antifriction bearings (in particular for insufficient number of measurements, only 4÷5 is a really difficult task due to complexity of working environment where such bearings are operated. Typical working environment for such objects must take account for operation time under various working conditions and accompanying (and disturbing signals, e.g. vibroacoustic ones. The sought assessment of the relationship between diagnostic signals and environmental noise can be determined from convolution of both diagnostic and environments signals that make up the complete set of received information. The convolution of these two series of signals can be obtained from an algorithm based on the Cauchy product. Then one has to find the coherence factor and the square of amplitude gain for the set of diagnostic signals with reference to various sets of signals received from environment, which makes it possible to evaluate cohesion of the investigated series of signals, thus their suitability to determine diagnostic threshold for tribologic signals intended for the analysis.

Phase synchronization of instrumental music signals

Science.gov (United States)

Mukherjee, Sayan; Palit, Sanjay Kumar; Banerjee, Santo; Ariffin, M. R. K.; Bhattacharya, D. K.

2014-06-01

Signal analysis is one of the finest scientific techniques in communication theory. Some quantitative and qualitative measures describe the pattern of a music signal, vary from one to another. Same musical recital, when played by different instrumentalists, generates different types of music patterns. The reason behind various patterns is the psycho-acoustic measures - Dynamics, Timber, Tonality and Rhythm, varies in each time. However, the psycho-acoustic study of the music signals does not reveal any idea about the similarity between the signals. For such cases, study of synchronization of long-term nonlinear dynamics may provide effective results. In this context, phase synchronization (PS) is one of the measures to show synchronization between two non-identical signals. In fact, it is very critical to investigate any other kind of synchronization for experimental condition, because those are completely non identical signals. Also, there exists equivalence between the phases and the distances of the diagonal line in Recurrence plot (RP) of the signals, which is quantifiable by the recurrence quantification measure τ-recurrence rate. This paper considers two nonlinear music signals based on same raga played by two eminent sitar instrumentalists as two non-identical sources. The psycho-acoustic study shows how the Dynamics, Timber, Tonality and Rhythm vary for the two music signals. Then, long term analysis in the form of phase space reconstruction is performed, which reveals the chaotic phase spaces for both the signals. From the RP of both the phase spaces, τ-recurrence rate is calculated. Finally by the correlation of normalized tau-recurrence rate of their 3D phase spaces and the PS of the two music signals has been established. The numerical results well support the analysis.

Nanoindentation of intervertebral disc tissues localised by SHG imaging

Czech Academy of Sciences Publication Activity Database

Šepitka, J.; Lukeš, J.; Staněk, L.; Filová, Eva; Burdíková, Zuzana; Řezníček, J.

2012-01-01

Roč. 15, Suppl.1 (2012), s. 335-336 ISSN 1025-5842 Institutional research plan: CEZ:AV0Z50390703; CEZ:AV0Z50390512; CEZ:AV0Z50110509 Keywords : nanoindentation * nanoDMA * endplate Subject RIV: BO - Biophysics; BO - Biophysics (FGU-C) Impact factor: 1.393, year: 2012

Quantum signaling game

International Nuclear Information System (INIS)

Frackiewicz, Piotr

2014-01-01

We present a quantum approach to a signaling game; a special kind of extensive game of incomplete information. Our model is based on quantum schemes for games in strategic form where players perform unitary operators on their own qubits of some fixed initial state and the payoff function is given by a measurement on the resulting final state. We show that the quantum game induced by our scheme coincides with a signaling game as a special case and outputs nonclassical results in general. As an example, we consider a quantum extension of the signaling game in which the chance move is a three-parameter unitary operator whereas the players' actions are equivalent to classical ones. In this case, we study the game in terms of Nash equilibria and refine the pure Nash equilibria adapting to the quantum game the notion of a weak perfect Bayesian equilibrium. (paper)

Selection-Mutation Dynamics of Signaling Games

Directory of Open Access Journals (Sweden)

Josef Hofbauer

2015-01-01

Full Text Available We study the structure of the rest points of signaling games and their dynamic behavior under selection-mutation dynamics by taking the case of three signals as our canonical example. Many rest points of the replicator dynamics of signaling games are not isolated and, therefore, not robust under perturbations. However, some of them attract open sets of initial conditions. We prove the existence of certain rest points of the selection-mutation dynamics close to Nash equilibria of the signaling game and show that all but the perturbed rest points close to strict Nash equilibria are dynamically unstable. This is an important result for the evolution of signaling behavior, since it shows that the second-order forces that are governed by mutation can increase the chances of successful signaling.

Long-distance signalling in plant defence.

Science.gov (United States)

Heil, Martin; Ton, Jurriaan

2008-06-01

Plants use inducible defence mechanisms to fend off harmful organisms. Resistance that is induced in response to local attack is often expressed systemically, that is, in organs that are not yet damaged. In the search for translocated defence signals, biochemical studies follow the physical movement of putative signals, and grafting experiments use mutants that are impaired in the production or perception of these signals. Long-distance signals can directly activate defence or can prime for the stronger and faster induction of defence. Historically, research has focused on the vascular transport of signalling metabolites, but volatiles can play a crucial role as well. We compare the advantages and constraints of vascular and airborne signals for the plant, and discuss how they can act in synergy to achieve optimised resistance in distal plant parts.

Photonic Ultra-Wideband 781.25-Mb/s Signal Generation and Transmission Incorporating Digital Signal Processing Detection

DEFF Research Database (Denmark)

Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

2009-01-01

The generation of photonic ultra-wideband (UWB) impulse signals using an uncooled distributed-feedback laser is proposed. For the first time, we experimentally demonstrate bit-for-bit digital signal processing (DSP) bit-error-rate measurements for transmission of a 781.25-Mb/s photonic UWB signal...

Foreground Subtraction and Signal reconstruction in redshifted 21cm Global Signal Experiments using Artificial Neural Networks

Science.gov (United States)

Choudhury, Madhurima; Datta, Abhirup

2018-05-01

Observations of HI 21cm transition line is a promising probe into the Dark Ages and Epoch-of-Reionization. Detection of this redshifted 21cm signal is one of the key science goal for several upcoming low-frequency radio telescopes like HERA, SKA and DARE. Other global signal experiments include EDGES, LEDA, BIGHORNS, SCI-HI, SARAS. One of the major challenges for the detection of this signal is the accuracy of the foreground source removal. Several novel techniques have been explored already to remove bright foregrounds from both interferometric as well as total power experiments. Here, we present preliminary results from our investigation on application of ANN to detect 21cm global signal amidst bright galactic foreground. Following the formalism of representing the global 21cm signal by 'tanh' model, this study finds that the global 21cm signal parameters can be accurately determined even in the presence of bright foregrounds represented by 3rd order log-polynomial or higher.

Lumbar lordosis and pars interarticularis fractures: a case-control study

International Nuclear Information System (INIS)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P.

2012-01-01

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G; Lewis, Mark; Juette, Arne; Cahir, John G; Toms, Andoni P [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P. [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Adjacent level effects of bi level disc replacement, bi level fusion and disc replacement plus fusion in cervical spine--a finite element based study.

Science.gov (United States)

Faizan, Ahmad; Goel, Vijay K; Biyani, Ashok; Garfin, Steven R; Bono, Christopher M

2012-03-01

Studies delineating the adjacent level effect of single level disc replacement systems have been reported in literature. The aim of this study was to compare the adjacent level biomechanics of bi-level disc replacement, bi-level fusion and a construct having adjoining level disc replacement and fusion system. In total, biomechanics of four models- intact, bi level disc replacement, bi level fusion and fusion plus disc replacement at adjoining levels- was studied to gain insight into the effects of various instrumentation systems on cranial and caudal adjacent levels using finite element analysis (73.6N+varying moment). The bi-level fusion models are more than twice as stiff as compared to the intact model during flexion-extension, lateral bending and axial rotation. Bi-level disc replacement model required moments lower than intact model (1.5Nm). Fusion plus disc replacement model required moment 10-25% more than intact model, except in extension. Adjacent level motions, facet loads and endplate stresses increased substantially in the bi-level fusion model. On the other hand, adjacent level motions, facet loads and endplate stresses were similar to intact for the bi-level disc replacement model. For the fusion plus disc replacement model, adjacent level motions, facet loads and endplate stresses were closer to intact model rather than the bi-level fusion model, except in extension. Based on our finite element analysis, fusion plus disc replacement procedure has less severe biomechanical effects on adjacent levels when compared to bi-level fusion procedure. Bi-level disc replacement procedure did not have any adverse mechanical effects on adjacent levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Digital Signal Processing applied to Physical Signals

CERN Document Server

Alberto, Diego; Musa, L

2011-01-01

It is well known that many of the scientific and technological discoveries of the XXI century will depend on the capability of processing and understanding a huge quantity of data. With the advent of the digital era, a fully digital and automated treatment can be designed and performed. From data mining to data compression, from signal elaboration to noise reduction, a processing is essential to manage and enhance features of interest after every data acquisition (DAQ) session. In the near future, science will go towards interdisciplinary research. In this work there will be given an example of the application of signal processing to different fields of Physics from nuclear particle detectors to biomedical examinations. In Chapter 1 a brief description of the collaborations that allowed this thesis is given, together with a list of the publications co-produced by the author in these three years. The most important notations, definitions and acronyms used in the work are also provided. In Chapter 2, the last r...

Blind Signal Classification via Spare Coding

Science.gov (United States)

2016-04-10

Blind Signal Classification via Sparse Coding Youngjune Gwon MIT Lincoln Laboratory gyj@ll.mit.edu Siamak Dastangoo MIT Lincoln Laboratory sia...achieve blind signal classification with no prior knowledge about signals (e.g., MCS, pulse shaping) in an arbitrary RF channel. Since modulated RF...classification method. Our results indicate that we can separate different classes of digitally modulated signals from blind sampling with 70.3% recall and 24.6

Network modeling reveals prevalent negative regulatory relationships between signaling sectors in Arabidopsis immune signaling.

Directory of Open Access Journals (Sweden)

Masanao Sato

Full Text Available Biological signaling processes may be mediated by complex networks in which network components and network sectors interact with each other in complex ways. Studies of complex networks benefit from approaches in which the roles of individual components are considered in the context of the network. The plant immune signaling network, which controls inducible responses to pathogen attack, is such a complex network. We studied the Arabidopsis immune signaling network upon challenge with a strain of the bacterial pathogen Pseudomonas syringae expressing the effector protein AvrRpt2 (Pto DC3000 AvrRpt2. This bacterial strain feeds multiple inputs into the signaling network, allowing many parts of the network to be activated at once. mRNA profiles for 571 immune response genes of 22 Arabidopsis immunity mutants and wild type were collected 6 hours after inoculation with Pto DC3000 AvrRpt2. The mRNA profiles were analyzed as detailed descriptions of changes in the network state resulting from the genetic perturbations. Regulatory relationships among the genes corresponding to the mutations were inferred by recursively applying a non-linear dimensionality reduction procedure to the mRNA profile data. The resulting static network model accurately predicted 23 of 25 regulatory relationships reported in the literature, suggesting that predictions of novel regulatory relationships are also accurate. The network model revealed two striking features: (i the components of the network are highly interconnected; and (ii negative regulatory relationships are common between signaling sectors. Complex regulatory relationships, including a novel negative regulatory relationship between the early microbe-associated molecular pattern-triggered signaling sectors and the salicylic acid sector, were further validated. We propose that prevalent negative regulatory relationships among the signaling sectors make the plant immune signaling network a "sector

Signal analysis for failure detection

International Nuclear Information System (INIS)

Parpaglione, M.C.; Perez, L.V.; Rubio, D.A.; Czibener, D.; D'Attellis, C.E.; Brudny, P.I.; Ruzzante, J.E.

1994-01-01

Several methods for analysis of acoustic emission signals are presented. They are mainly oriented to detection of changes in noisy signals and characterization of higher amplitude discrete pulses or bursts. The aim was to relate changes and events with failure, crack or wear in materials, being the final goal to obtain automatic means of detecting such changes and/or events. Performance evaluation was made using both simulated and laboratory test signals. The methods being presented are the following: 1. Application of the Hopfield Neural Network (NN) model for classifying faults in pipes and detecting wear of a bearing. 2. Application of the Kohonnen and Back Propagation Neural Network model for the same problem. 3. Application of Kalman filtering to determine time occurrence of bursts. 4. Application of a bank of Kalman filters (KF) for failure detection in pipes. 5. Study of amplitude distribution of signals for detecting changes in their shape. 6. Application of the entropy distance to measure differences between signals. (author). 10 refs, 11 figs

Signal processing for passive detection and classification of underwater acoustic signals

Science.gov (United States)

Chung, Kil Woo

2011-12-01

This dissertation examines signal processing for passive detection, classification and tracking of underwater acoustic signals for improving port security and the security of coastal and offshore operations. First, we consider the problem of passive acoustic detection of a diver in a shallow water environment. A frequency-domain multi-band matched-filter approach to swimmer detection is presented. The idea is to break the frequency contents of the hydrophone signals into multiple narrow frequency bands, followed by time averaged (about half of a second) energy calculation over each band. Then, spectra composed of such energy samples over the chosen frequency bands are correlated to form a decision variable. The frequency bands with highest Signal/Noise ratio are used for detection. The performance of the proposed approach is demonstrated for experimental data collected for a diver in the Hudson River. We also propose a new referenceless frequency-domain multi-band detector which, unlike other reference-based detectors, does not require a diver specific signature. Instead, our detector matches to a general feature of the diver spectrum in the high frequency range: the spectrum is roughly periodic in time and approximately flat when the diver exhales. The performance of the proposed approach is demonstrated by using experimental data collected from the Hudson River. Moreover, we present detection, classification and tracking of small vessel signals. Hydroacoustic sensors can be applied for the detection of noise generated by vessels, and this noise can be used for vessel detection, classification and tracking. This dissertation presents recent improvements aimed at the measurement and separation of ship DEMON (Detection of Envelope Modulation on Noise) acoustic signatures in busy harbor conditions. Ship signature measurements were conducted in the Hudson River and NY Harbor. The DEMON spectra demonstrated much better temporal stability compared with the full ship

Signal modulation as a mechanism for handicap disposal

Science.gov (United States)

Gavassa, Sat; Silva, Ana C.; Gonzalez, Emmanuel; Stoddard, Philip K.

2012-01-01

Signal honesty may be compromised when heightened competition provides incentive for signal exaggeration. Some degree of honesty might be maintained by intrinsic handicap costs on signalling or through imposition of extrinsic costs, such as social punishment of low quality cheaters. Thus, theory predicts a delicate balance between signal enhancement and signal reliability that varies with degree of social competition, handicap cost, and social cost. We investigated whether male sexual signals of the electric fish Brachyhypopomus gauderio would become less reliable predictors of body length when competition provides incentives for males to boost electric signal amplitude. As expected, social competition under natural field conditions and in controlled lab experiments drove males to enhance their signals. However, signal enhancement improved the reliability of the information conveyed by the signal, as revealed in the tightening of the relationship between signal amplitude and body length. Signal augmentation in male B. gauderio was independent of body length, and thus appeared not to be curtailed through punishment of low quality (small) individuals. Rather, all individuals boosted their signals under high competition, but those whose signals were farthest from the predicted value under low competition boosted signal amplitude the most. By elimination, intrinsic handicap cost of signal production, rather than extrinsic social cost, appears to be the basis for the unexpected reinforcement of electric signal honesty under social competition. Signal modulation may provide its greatest advantage to the signaller as a mechanism for handicap disposal under low competition rather than as a mechanism for exaggeration of quality under high competition. PMID:22665940

Digital signal processing with kernel methods

CERN Document Server

Rojo-Alvarez, José Luis; Muñoz-Marí, Jordi; Camps-Valls, Gustavo

2018-01-01

A realistic and comprehensive review of joint approaches to machine learning and signal processing algorithms, with application to communications, multimedia, and biomedical engineering systems Digital Signal Processing with Kernel Methods reviews the milestones in the mixing of classical digital signal processing models and advanced kernel machines statistical learning tools. It explains the fundamental concepts from both fields of machine learning and signal processing so that readers can quickly get up to speed in order to begin developing the concepts and application software in their own research. Digital Signal Processing with Kernel Methods provides a comprehensive overview of kernel methods in signal processing, without restriction to any application field. It also offers example applications and detailed benchmarking experiments with real and synthetic datasets throughout. Readers can find further worked examples with Matlab source code on a website developed by the authors. * Presents the necess...

Digital storage of repeated signals

International Nuclear Information System (INIS)

Prozorov, S.P.

1984-01-01

An independent digital storage system designed for repeated signal discrimination from background noises is described. The signal averaging is performed off-line in the real time mode by means of multiple selection of the investigated signal and integration in each point. Digital values are added in a simple summator and the result is recorded the storage device with the volume of 1024X20 bit from where it can be output on an oscillograph, a plotter or transmitted to a compUter for subsequent processing. The described storage is reliable and simple device on one base of which the systems for the nuclear magnetic resonapce signal acquisition in different experiments are developed

Advanced digital signal processing and noise reduction

CERN Document Server

Vaseghi, Saeed V

2008-01-01

Digital signal processing plays a central role in the development of modern communication and information processing systems. The theory and application of signal processing is concerned with the identification, modelling and utilisation of patterns and structures in a signal process. The observation signals are often distorted, incomplete and noisy and therefore noise reduction, the removal of channel distortion, and replacement of lost samples are important parts of a signal processing system. The fourth edition of Advanced Digital Signal Processing and Noise Reduction updates an

Problems of the Synthesis of Radar Signals,

Science.gov (United States)

1981-05-14

recorded, finding out approximation/approach to certain signal x(t) , logical to ascribe a(w.) the phase spc -ctrum cf signal xft). the diffsrences...of the given cne). e will r~ spc -.ively d-stirguish se- cf Ch, signals of fixed Fericd cf rims X. frcm the sst cf Ch. signals of drbitrary duration X...XeXP~j IjM+a .t * An error in asymptotic soluticr can be ccnsidered now, being congruent/ squating found ChM signal z.,g(t) with ganerating signal

DMPD: When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transduction. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18631453 When signaling pathways collide: positive and negative regulation of toll-...uction. PubmedID 18631453 Title When signaling pathways collide: positive and neg...l) Show When signaling pathways collide: positive and negative regulation of toll-likereceptor signal transd...likereceptor signal transduction. O'Neill LA. Immunity. 2008 Jul 18;29(1):12-20. (.png) (.svg) (.html) (.csm

Hedgehog Signaling in Endochondral Ossification

Directory of Open Access Journals (Sweden)

Shinsuke Ohba

2016-06-01

Full Text Available Hedgehog (Hh signaling plays crucial roles in the patterning and morphogenesis of various organs within the bodies of vertebrates and insects. Endochondral ossification is one of the notable developmental events in which Hh signaling acts as a master regulator. Among three Hh proteins in mammals, Indian hedgehog (Ihh is known to work as a major Hh input that induces biological impact of Hh signaling on the endochondral ossification. Ihh is expressed in prehypertrophic and hypertrophic chondrocytes of developing endochondral bones. Genetic studies so far have demonstrated that the Ihh-mediated activation of Hh signaling synchronizes chondrogenesis and osteogenesis during endochondral ossification by regulating the following processes: (1 chondrocyte differentiation; (2 chondrocyte proliferation; and (3 specification of bone-forming osteoblasts. Ihh not only forms a negative feedback loop with parathyroid hormone-related protein (PTHrP to maintain the growth plate length, but also directly promotes chondrocyte propagation. Ihh input is required for the specification of progenitors into osteoblast precursors. The combinatorial approaches of genome-wide analyses and mouse genetics will facilitate understanding of the regulatory mechanisms underlying the roles of Hh signaling in endochondral ossification, providing genome-level evidence of the potential of Hh signaling for the treatment of skeletal disorders.

Hedgehog Signaling in Endochondral Ossification

Science.gov (United States)

Ohba, Shinsuke

2016-01-01

Hedgehog (Hh) signaling plays crucial roles in the patterning and morphogenesis of various organs within the bodies of vertebrates and insects. Endochondral ossification is one of the notable developmental events in which Hh signaling acts as a master regulator. Among three Hh proteins in mammals, Indian hedgehog (Ihh) is known to work as a major Hh input that induces biological impact of Hh signaling on the endochondral ossification. Ihh is expressed in prehypertrophic and hypertrophic chondrocytes of developing endochondral bones. Genetic studies so far have demonstrated that the Ihh-mediated activation of Hh signaling synchronizes chondrogenesis and osteogenesis during endochondral ossification by regulating the following processes: (1) chondrocyte differentiation; (2) chondrocyte proliferation; and (3) specification of bone-forming osteoblasts. Ihh not only forms a negative feedback loop with parathyroid hormone-related protein (PTHrP) to maintain the growth plate length, but also directly promotes chondrocyte propagation. Ihh input is required for the specification of progenitors into osteoblast precursors. The combinatorial approaches of genome-wide analyses and mouse genetics will facilitate understanding of the regulatory mechanisms underlying the roles of Hh signaling in endochondral ossification, providing genome-level evidence of the potential of Hh signaling for the treatment of skeletal disorders. PMID:29615586

Drought Signaling in Plants

Indian Academy of Sciences (India)

depending upon the source and nature of signaling: (i) hormone signal, (ii) .... plants to regulate the rate of transpiration through minor structural .... cell has to keep spending energy (in the form of A TP) to maintain a .... enzymes and proteins in the regulation of cellular metabolism can be determined by either inactivating.

Flanking signal and mature peptide residues influence signal peptide cleavage

Directory of Open Access Journals (Sweden)

Ranganathan Shoba

2008-12-01

Full Text Available Abstract Background Signal peptides (SPs mediate the targeting of secretory precursor proteins to the correct subcellular compartments in prokaryotes and eukaryotes. Identifying these transient peptides is crucial to the medical, food and beverage and biotechnology industries yet our understanding of these peptides remains limited. This paper examines the most common type of signal peptides cleavable by the endoprotease signal peptidase I (SPase I, and the residues flanking the cleavage sites of three groups of signal peptide sequences, namely (i eukaryotes (Euk (ii Gram-positive (Gram+ bacteria, and (iii Gram-negative (Gram- bacteria. Results In this study, 2352 secretory peptide sequences from a variety of organisms with amino-terminal SPs are extracted from the manually curated SPdb database for analysis based on physicochemical properties such as pI, aliphatic index, GRAVY score, hydrophobicity, net charge and position-specific residue preferences. Our findings show that the three groups share several similarities in general, but they display distinctive features upon examination in terms of their amino acid compositions and frequencies, and various physico-chemical properties. Thus, analysis or prediction of their sequences should be separated and treated as distinct groups. Conclusion We conclude that the peptide segment recognized by SPase I extends to the start of the mature protein to a limited extent, upon our survey of the amino acid residues surrounding the cleavage processing site. These flanking residues possibly influence the cleavage processing and contribute to non-canonical cleavage sites. Our findings are applicable in defining more accurate prediction tools for recognition and identification of cleavage site of SPs.

Defective chemokine signal integration in leukocytes lacking activator of G protein signaling 3 (AGS3).

Science.gov (United States)

Branham-O'Connor, Melissa; Robichaux, William G; Zhang, Xian-Kui; Cho, Hyeseon; Kehrl, John H; Lanier, Stephen M; Blumer, Joe B

2014-04-11

Activator of G-protein signaling 3 (AGS3, gene name G-protein signaling modulator-1, Gpsm1), an accessory protein for G-protein signaling, has functional roles in the kidney and CNS. Here we show that AGS3 is expressed in spleen, thymus, and bone marrow-derived dendritic cells, and is up-regulated upon leukocyte activation. We explored the role of AGS3 in immune cell function by characterizing chemokine receptor signaling in leukocytes from mice lacking AGS3. No obvious differences in lymphocyte subsets were observed. Interestingly, however, AGS3-null B and T lymphocytes and bone marrow-derived dendritic cells exhibited significant chemotactic defects as well as reductions in chemokine-stimulated calcium mobilization and altered ERK and Akt activation. These studies indicate a role for AGS3 in the regulation of G-protein signaling in the immune system, providing unexpected venues for the potential development of therapeutic agents that modulate immune function by targeting these regulatory mechanisms.

Flash signal evolution in Photinus fireflies: character displacement and signal exploitation in a visual communication system.

Science.gov (United States)

Stanger-Hall, Kathrin F; Lloyd, James E

2015-03-01

Animal communication is an intriguing topic in evolutionary biology. In this comprehensive study of visual signal evolution, we used a phylogenetic approach to study the evolution of the flash communication system of North American fireflies. The North American firefly genus Photinus contains 35 described species with simple ON-OFF visual signals, and information on habitat types, sympatric congeners, and predators. This makes them an ideal study system to test hypotheses on the evolution of male and female visual signal traits. Our analysis of 34 Photinus species suggests two temporal pattern generators: one for flash duration and one for flash intervals. Reproductive character displacement was a main factor for signal divergence in male flash duration among sympatric Photinus species. Male flash pattern intervals (i.e., the duration of the dark periods between signals) were positively correlated with the number of sympatric Photuris fireflies, which include predators of Photinus. Females of different Photinus species differ in their response preferences to male traits. As in other communication systems, firefly male sexual signals seem to be a compromise between optimizing mating success (sexual selection) and minimizing predation risk (natural selection). An integrative model for Photinus signal evolution is proposed. © 2015 The Author(s).

Clinical Efficacy and Its Prognostic Factor of Percutaneous Endoscopic Lumbar Annuloplasty and Nucleoplasty for the Treatment of Patients with Discogenic Low Back Pain.

Science.gov (United States)

Lee, Jung Hwan; Lee, Sang-Ho

2017-09-01

The choice of appropriate treatment of discogenic low back pain (DLBP) frequently is difficult. This study sought to identify the clinical efficacy of percutaneous endoscopic lumbar annuloplasty and nucleoplasty (PELAN) to treat patients with DLBP and to investigate prognostic clinical or radiologic variables. Eighty-nine patients with a diagnosis of DLBP who underwent PELAN were included. Numeric Rating Scale (NRS) for back pain, Oswestry Disability Index % (ODI%), and modified Macnab criteria were measured at short-term (3-4 weeks) and long-term follow-up period (at least 12 months) to investigate clinical efficacy of PELAN. The subjects were defined as successful group in case of 50% or more reduction of NRS, 40% or more reduction of ODI%, and good or excellent response of Macnab criteria. Clinical and radiologic variables were compared between successful and unsuccessful outcomes group to determine prognostic variables. NRS and ODI% were significantly reduced at short- and long-term follow-up after PELAN. Sixty-two (69.7%) and 68 (76.4%) obtained successful NRS reduction and 59 (66.3%) and 68 (76.4%) accomplished successful ODI% reduction at short-term and long-term follow-up, respectively. Successful Mcnab response was found in 61% at short term and 65.2% at long term. Pain during waist flexion among clinical variables was significantly related to good clinical outcomes and Modic change among radiologic variables was significantly related to poor clinical outcomes. PELAN provided favorable outcomes in patients with DLBP who were refractory to conservative treatments. Flexion pain was good prognostic, and Modic change was a poor prognostic variable. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of blind signal separation methods

NARCIS (Netherlands)

Schobben, D.W.E.; Torkkola, K.; Smaragdis, P.

1999-01-01

Recently many new Blind Signal Separation BSS algorithms have been introduced Authors evaluate the performance of their algorithms in various ways Among these are speech recognition rates plots of separated signals plots of cascaded mixingunmixing impulse responses and signal to noise ratios Clearly

49 CFR 236.804 - Signal, block.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, block. 236.804 Section 236.804 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Signal, block. A roadway signal operated either automatically or manually at the entrance to a block. ...

Phase noise mitigation of QPSK signal utilizing phase-locked multiplexing of signal harmonics and amplitude saturation.

Science.gov (United States)

Mohajerin-Ariaei, Amirhossein; Ziyadi, Morteza; Chitgarha, Mohammad Reza; Almaiman, Ahmed; Cao, Yinwen; Shamee, Bishara; Yang, Jeng-Yuan; Akasaka, Youichi; Sekiya, Motoyoshi; Takasaka, Shigehiro; Sugizaki, Ryuichi; Touch, Joseph D; Tur, Moshe; Langrock, Carsten; Fejer, Martin M; Willner, Alan E

2015-07-15

We demonstrate an all-optical phase noise mitigation scheme based on the generation, delay, and coherent summation of higher order signal harmonics. The signal, its third-order harmonic, and their corresponding delayed variant conjugates create a staircase phase-transfer function that quantizes the phase of quadrature-phase-shift-keying (QPSK) signal to mitigate phase noise. The signal and the harmonics are automatically phase-locked multiplexed, avoiding the need for phase-based feedback loop and injection locking to maintain coherency. The residual phase noise converts to amplitude noise in the quantizer stage, which is suppressed by parametric amplification in the saturation regime. Phase noise reduction of ∼40% and OSNR-gain of ∼3  dB at BER 10(-3) are experimentally demonstrated for 20- and 30-Gbaud QPSK input signals.

Liquid Argon TPC Signal Formation, Signal Processing and Hit Reconstruction

Energy Technology Data Exchange (ETDEWEB)

Baller, Bruce [Fermilab

2017-03-11

This document describes the early stage of the reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions requires knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise.

Automatic modulation recognition of communication signals

CERN Document Server

Azzouz, Elsayed Elsayed

1996-01-01

Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

Electronic signal conditioning

CERN Document Server

NEWBY, BRUCE

1994-01-01

At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

Genomic signal processing

CERN Document Server

Shmulevich, Ilya

2007-01-01

Genomic signal processing (GSP) can be defined as the analysis, processing, and use of genomic signals to gain biological knowledge, and the translation of that knowledge into systems-based applications that can be used to diagnose and treat genetic diseases. Situated at the crossroads of engineering, biology, mathematics, statistics, and computer science, GSP requires the development of both nonlinear dynamical models that adequately represent genomic regulation, and diagnostic and therapeutic tools based on these models. This book facilitates these developments by providing rigorous mathema

Multivariate Analysis for the Processing of Signals

Directory of Open Access Journals (Sweden)

Beattie J.R.

2014-01-01

Full Text Available Real-world experiments are becoming increasingly more complex, needing techniques capable of tracking this complexity. Signal based measurements are often used to capture this complexity, where a signal is a record of a sample’s response to a parameter (e.g. time, displacement, voltage, wavelength that is varied over a range of values. In signals the responses at each value of the varied parameter are related to each other, depending on the composition or state sample being measured. Since signals contain multiple information points, they have rich information content but are generally complex to comprehend. Multivariate Analysis (MA has profoundly transformed their analysis by allowing gross simplification of the tangled web of variation. In addition MA has also provided the advantage of being much more robust to the influence of noise than univariate methods of analysis. In recent years, there has been a growing awareness that the nature of the multivariate methods allows exploitation of its benefits for purposes other than data analysis, such as pre-processing of signals with the aim of eliminating irrelevant variations prior to analysis of the signal of interest. It has been shown that exploiting multivariate data reduction in an appropriate way can allow high fidelity denoising (removal of irreproducible non-signals, consistent and reproducible noise-insensitive correction of baseline distortions (removal of reproducible non-signals, accurate elimination of interfering signals (removal of reproducible but unwanted signals and the standardisation of signal amplitude fluctuations. At present, the field is relatively small but the possibilities for much wider application are considerable. Where signal properties are suitable for MA (such as the signal being stationary along the x-axis, these signal based corrections have the potential to be highly reproducible, and highly adaptable and are applicable in situations where the data is noisy or

Fundamentals of statistical signal processing

CERN Document Server

Kay, Steven M

1993-01-01

A unified presentation of parameter estimation for those involved in the design and implementation of statistical signal processing algorithms. Covers important approaches to obtaining an optimal estimator and analyzing its performance; and includes numerous examples as well as applications to real- world problems. MARKETS: For practicing engineers and scientists who design and analyze signal processing systems, i.e., to extract information from noisy signals — radar engineer, sonar engineer, geophysicist, oceanographer, biomedical engineer, communications engineer, economist, statistician, physicist, etc.

Purinergic signalling in epithelial ion transport

DEFF Research Database (Denmark)

Novak, Ivana

2011-01-01

, including ion transport. In this review, I will first introduce the main components of the extracellular ATP signalling, which have become known as the purinergic signalling system. With more than 50 components or processes, just at cell membranes, it ranks as one of the most versatile signalling systems......-regulators of secretion. On an organ level, both receptor types can exert physiological functions and together with other partners in the purinergic signalling, integrated models for epithelial secretion and absorption are emerging....

Calcium Signaling in Taste Cells

Science.gov (United States)

Medler, Kathryn F.

2014-01-01

The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. PMID:25450977

49 CFR 236.806 - Signal, home.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, home. 236.806 Section 236.806 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Signal, home. A roadway signal at the entrance to a route or block to govern trains in entering and using...

Acoustic signal recovery by thermal demodulation

Science.gov (United States)

Boullosa, R. R.; Santillán, Arturo O.

2006-10-01

One operating mode of recently developed thermoacoustic transducers is as an audio speaker that uses an input superimposed on a direct current; as a result, the audio signal occurs at the same frequency as the input signal. To extend the potential applications of these kinds of sources, the authors propose an alternative driving mode in which a simple thermoacoustic device, consisting of a metal film over a substrate and a heat sink, is excited with a high frequency sinusoid that is amplitude modulated by a lower frequency signal. They show that the modulating signal is recovered in the radiated waves due to a mechanism that is inherent to this type of thermoacoustic process. If the frequency of the carrier is higher than 30kHz and any modulating signal (the one of interest) is in the audio frequency range, only this signal will be heard. Thus, the thermoacoustic device operates as an audio-band, self-demodulating speaker.

Signaling profiling at the single-cell level identifies a distinct signaling signature in murine hematopoietic stem cells.

Science.gov (United States)

Du, Juan; Wang, Jinyong; Kong, Guangyao; Jiang, Jing; Zhang, Jingfang; Liu, Yangang; Tong, Wei; Zhang, Jing

2012-07-01

Hematopoietic stem cell (HSC) function is tightly regulated by cytokine signaling. Although phospho-flow cytometry allows us to study signaling in defined populations of cells, there has been tremendous hurdle to carry out this study in rare HSCs due to unrecoverable critical HSC markers, low HSC number, and poor cell recovery rate. Here, we overcame these difficulties and developed a "HSC phospho-flow" method to analyze cytokine signaling in murine HSCs at the single-cell level and compare HSC signaling profile to that of multipotent progenitors (MPPs), a cell type immediately downstream of HSCs, and commonly used Lin(-) cKit(+) cells (LK cells, enriched for myeloid progenitors). We chose to study signaling evoked from three representative cytokines, stem cell factor (SCF) and thrombopoietin (TPO) that are essential for HSC function and granulocyte macrophage-colony-stimulating factor (GM-CSF) that is dispensable for HSCs. HSCs display a distinct TPO and GM-CSF signaling signature from MPPs and LK cells, which highly correlates with receptor surface expression. In contrast, although majority of LK cells express lower levels of cKit than HSCs and MPPs, SCF-evoked ERK1/2 activation in LK cells shows a significantly increased magnitude for a prolonged period. These results suggest that specific cellular context plays a more important role than receptor surface expression in SCF signaling. Our study of HSC signaling at the homeostasis stage paves the way to investigate signaling changes in HSCs under conditions of stress, aging, and hematopoietic diseases. Copyright © 2012 AlphaMed Press.

Bystander signaling via oxidative metabolism.

Science.gov (United States)

Sawal, Humaira Aziz; Asghar, Kashif; Bureik, Matthias; Jalal, Nasir

2017-01-01

The radiation-induced bystander effect (RIBE) is the initiation of biological end points in cells (bystander cells) that are not directly traversed by an incident-radiation track, but are in close proximity to cells that are receiving the radiation. RIBE has been indicted of causing DNA damage via oxidative stress, besides causing direct damage, inducing tumorigenesis, producing micronuclei, and causing apoptosis. RIBE is regulated by signaling proteins that are either endogenous or secreted by cells as a means of communication between cells, and can activate intracellular or intercellular oxidative metabolism that can further trigger signaling pathways of inflammation. Bystander signals can pass through gap junctions in attached cell lines, while the suspended cell lines transmit these signals via hormones and soluble proteins. This review provides the background information on how reactive oxygen species (ROS) act as bystander signals. Although ROS have a very short half-life and have a nanometer-scale sphere of influence, the wide variety of ROS produced via various sources can exert a cumulative effect, not only in forming DNA adducts but also setting up signaling pathways of inflammation, apoptosis, cell-cycle arrest, aging, and even tumorigenesis. This review outlines the sources of the bystander effect linked to ROS in a cell, and provides methods of investigation for researchers who would like to pursue this field of science.

Understanding signal integrity

CERN Document Server

Thierauf, Stephen C

2010-01-01

This unique book provides you with practical guidance on understanding and interpreting signal integrity (SI) performance to help you with your challenging circuit board design projects. You find high-level discussions of important SI concepts presented in a clear and easily accessible format, including question and answer sections and bulleted lists.This valuable resource features rules of thumb and simple equations to help you make estimates of critical signal integrity parameters without using circuit simulators of CAD (computer-aided design). The book is supported with over 120 illustratio

A Serpentine Way to Signaling

Indian Academy of Sciences (India)

IAS Admin

the cell. The receptor transfers the signal to intracellular proteins ... and molecular mechanisms of GPCR signaling and how this discovery impacts ..... stabilize GPCR–G-protein interaction and resolve dynamics of ... elucidation stages. Kobilka.

State determination for composite systems of two spatial qubits

International Nuclear Information System (INIS)

Lima, G; Torres-Ruiz, F A; Neves, L; Delgado, A; Saavedra, C; Padua, S

2007-01-01

In a recent letter [Phys. Rev. Lett. 94, 100501 (2005)], we presented a scheme for generating pure entangled states of spatial qudits using transverse correlations of parametric down-converted photons. Here we show how the modication of this scheme can be used to generate mixed states and we investigate the state determination for composite systems of two spatial qubits, motivated by the fact that quantum information protocols may be easier to be implemented for this case. By means of local operations on the twin photons we were able to perform the quantum tomography process to reconstruct the density matrix of a mixed state of two spatial qubits

Next Steps in Signaling (NSIS): Framework

NARCIS (Netherlands)

Hancock, R.; Loughney, J.; van den Bosch, S.; Hancock, R.; Karagiannis, Georgios; Loughney, J.; van den Bosch, S.

The Next Steps in Signaling (NSIS) working group is considering protocols for signaling information about a data flow along its path in the network. The NSIS suite of protocols is envisioned to support various signaling applications that need to install and/or manipulate such state in the network.

Signals and systems primer with Matlab

CERN Document Server

Poularikas, Alexander D

2006-01-01

Signals and Systems Primer with MATLAB® equally emphasizes the fundamentals of both analog and digital signals and systems. To ensure insight into the basic concepts and methods, the text presents a variety of examples that illustrate a wide range of applications, from microelectromechanical to worldwide communication systems. It also provides MATLAB functions and procedures for practice and verification of these concepts.Taking a pedagogical approach, the author builds a solid foundation in signal processing as well as analog and digital systems. The book first introduces orthogonal signals,

Advanced Methods of Biomedical Signal Processing

CERN Document Server

Cerutti, Sergio

2011-01-01

This book grew out of the IEEE-EMBS Summer Schools on Biomedical Signal Processing, which have been held annually since 2002 to provide the participants state-of-the-art knowledge on emerging areas in biomedical engineering. Prominent experts in the areas of biomedical signal processing, biomedical data treatment, medicine, signal processing, system biology, and applied physiology introduce novel techniques and algorithms as well as their clinical or physiological applications. The book provides an overview of a compelling group of advanced biomedical signal processing techniques, such as mult

Handbook of Signal Processing in Acoustics

CERN Document Server

Havelock, David; Vorländer, Michael

2009-01-01

The Handbook of Signal Processing in Acoustics presents signal processing as it is practiced in the field of acoustics. The Handbook is organized by areas of acoustics, with recognized leaders coordinating the self-contained chapters of each section. It brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of signal processing in acoustics. Success in acoustic applications often requires juggling both the acoustic and the signal processing parameters of the problem. This handbook brings the key issues from both into perspective and is complementary to other reference material on the two subjects. It is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.

Signal classification for acoustic neutrino detection

International Nuclear Information System (INIS)

Neff, M.; Anton, G.; Enzenhöfer, A.; Graf, K.; Hößl, J.; Katz, U.; Lahmann, R.; Richardt, C.

2012-01-01

This article focuses on signal classification for deep-sea acoustic neutrino detection. In the deep sea, the background of transient signals is very diverse. Approaches like matched filtering are not sufficient to distinguish between neutrino-like signals and other transient signals with similar signature, which are forming the acoustic background for neutrino detection in the deep-sea environment. A classification system based on machine learning algorithms is analysed with the goal to find a robust and effective way to perform this task. For a well-trained model, a testing error on the level of 1% is achieved for strong classifiers like Random Forest and Boosting Trees using the extracted features of the signal as input and utilising dense clusters of sensors instead of single sensors.

Estimation of neural energy in microelectrode signals

Science.gov (United States)

Gaumond, R. P.; Clement, R.; Silva, R.; Sander, D.

2004-09-01

We considered the problem of determining the neural contribution to the signal recorded by an intracortical electrode. We developed a linear least-squares approach to determine the energy fraction of a signal attributable to an arbitrary number of autocorrelation-defined signals buried in noise. Application of the method requires estimation of autocorrelation functions Rap(tgr) characterizing the action potential (AP) waveforms and Rn(tgr) characterizing background noise. This method was applied to the analysis of chronically implanted microelectrode signals from motor cortex of rat. We found that neural (AP) energy consisted of a large-signal component which grows linearly with the number of threshold-detected neural events and a small-signal component unrelated to the count of threshold-detected AP signals. The addition of pseudorandom noise to electrode signals demonstrated the algorithm's effectiveness for a wide range of noise-to-signal energy ratios (0.08 to 39). We suggest, therefore, that the method could be of use in providing a measure of neural response in situations where clearly identified spike waveforms cannot be isolated, or in providing an additional 'background' measure of microelectrode neural activity to supplement the traditional AP spike count.

A Low-cost Multi-channel Analogue Signal Generator

CERN Document Server

Müller, F; The ATLAS collaboration; Shen, W; Stamen, R

2009-01-01

A scalable multi-channel analogue signal generator is presented. It uses a commercial low-cost graphics card with multiple outputs in a standard PC as signal source. Each color signal serves as independent channel to generate an analogue signal. A custom-built external PCB was developed to adjust the graphics card output voltage levels for a specific task, which needed differential signals. The system furthermore comprises a software package to program the signal shape. The signal generator was successfully used as independent test bed for the ATLAS Level-1 Trigger Pre-Processor, providing up to 16 analogue signals.

Signal Incongruence and its Consequences

DEFF Research Database (Denmark)

Vergne, Jean-Philippe; Wernicke, Maria Stokholm; Brenner, Steffen

2018-01-01

theory on signal incongruence, we find that firms engaged in philanthropy receive more media disapproval when they overcompensate their CEO, but they are also more likely to decrease CEO overcompensation as a response. Our study contributes to the signaling literature by theorizing about signal......We draw on the signaling and infomediary literatures to examine how media evaluations of CEO overcompensation (a negative cue associated with selfishness and greed) are affected by the presence of corporate philanthropy (a positive cue associated with altruism and generosity). In line with our...... incongruence, and to infomediary and corporate governance research by showing that media disapproval can lead to lower executive compensation. We also reconcile two conflicting views on firm prosocial behavior by showing that, in the presence of incongruent cues, philanthropy can simultaneously enhance...

Ultrasound imaging using coded signals

DEFF Research Database (Denmark)

Misaridis, Athanasios

Modulated (or coded) excitation signals can potentially improve the quality and increase the frame rate in medical ultrasound scanners. The aim of this dissertation is to investigate systematically the applicability of modulated signals in medical ultrasound imaging and to suggest appropriate...... methods for coded imaging, with the goal of making better anatomic and flow images and three-dimensional images. On the first stage, it investigates techniques for doing high-resolution coded imaging with improved signal-to-noise ratio compared to conventional imaging. Subsequently it investigates how...... coded excitation can be used for increasing the frame rate. The work includes both simulated results using Field II, and experimental results based on measurements on phantoms as well as clinical images. Initially a mathematical foundation of signal modulation is given. Pulse compression based...

Signal transforms in dynamic measurements

CERN Document Server

Layer, Edward

2015-01-01

This book is devoted to the analysis of measurement signals which requires specific mathematical operations like Convolution, Deconvolution, Laplace, Fourier, Hilbert, Wavelet or Z transform which are all presented in the present book. The different problems refer to the modulation of signals, filtration of disturbance as well as to the orthogonal signals and their use in digital form for the measurement of current, voltage, power and frequency are also widely discussed. All the topics covered in this book are presented in detail and illustrated by means of examples in MathCad and LabVIEW. This book provides a useful source for researchers, scientists and engineers who in their daily work are required to deal with problems of measurement and signal processing and can also be helpful to undergraduate students of electrical engineering.    

Modularized TGFbeta-Smad Signaling Pathway

Science.gov (United States)

Li, Yongfeng; Wang, M.; Carra, C.; Cucinotta, F. A.

2011-01-01

The Transforming Growth Factor beta (TGFbeta) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. It can be induced by several factors, including ionizing radiation. It is regulated by Smads in a negative feedback loop through promoting increases in the regulatory Smads in the cell nucleus, and subsequent expression of inhibitory Smad, Smad7 to form a ubiquitin ligase with Smurf targeting active TGF receptors for degradation. In this work, we proposed a mathematical model to study the radiation-induced Smad-regulated TGF signaling pathway. By modularization, we are able to analyze each module (subsystem) and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, along the TGF signaling pathway is discussed by mathematical analysis and numerical simulation.

Reconstruction and signal propagation analysis of the Syk signaling network in breast cancer cells.

Directory of Open Access Journals (Sweden)

Aurélien Naldi

2017-03-01

Full Text Available The ability to build in-depth cell signaling networks from vast experimental data is a key objective of computational biology. The spleen tyrosine kinase (Syk protein, a well-characterized key player in immune cell signaling, was surprisingly first shown by our group to exhibit an onco-suppressive function in mammary epithelial cells and corroborated by many other studies, but the molecular mechanisms of this function remain largely unsolved. Based on existing proteomic data, we report here the generation of an interaction-based network of signaling pathways controlled by Syk in breast cancer cells. Pathway enrichment of the Syk targets previously identified by quantitative phospho-proteomics indicated that Syk is engaged in cell adhesion, motility, growth and death. Using the components and interactions of these pathways, we bootstrapped the reconstruction of a comprehensive network covering Syk signaling in breast cancer cells. To generate in silico hypotheses on Syk signaling propagation, we developed a method allowing to rank paths between Syk and its targets. We first annotated the network according to experimental datasets. We then combined shortest path computation with random walk processes to estimate the importance of individual interactions and selected biologically relevant pathways in the network. Molecular and cell biology experiments allowed to distinguish candidate mechanisms that underlie the impact of Syk on the regulation of cortactin and ezrin, both involved in actin-mediated cell adhesion and motility. The Syk network was further completed with the results of our biological validation experiments. The resulting Syk signaling sub-networks can be explored via an online visualization platform.

Joint Maximum Likelihood Time Delay Estimation of Unknown Event-Related Potential Signals for EEG Sensor Signal Quality Enhancement

Science.gov (United States)

Kim, Kyungsoo; Lim, Sung-Ho; Lee, Jaeseok; Kang, Won-Seok; Moon, Cheil; Choi, Ji-Woong

2016-01-01

Electroencephalograms (EEGs) measure a brain signal that contains abundant information about the human brain function and health. For this reason, recent clinical brain research and brain computer interface (BCI) studies use EEG signals in many applications. Due to the significant noise in EEG traces, signal processing to enhance the signal to noise power ratio (SNR) is necessary for EEG analysis, especially for non-invasive EEG. A typical method to improve the SNR is averaging many trials of event related potential (ERP) signal that represents a brain’s response to a particular stimulus or a task. The averaging, however, is very sensitive to variable delays. In this study, we propose two time delay estimation (TDE) schemes based on a joint maximum likelihood (ML) criterion to compensate the uncertain delays which may be different in each trial. We evaluate the performance for different types of signals such as random, deterministic, and real EEG signals. The results show that the proposed schemes provide better performance than other conventional schemes employing averaged signal as a reference, e.g., up to 4 dB gain at the expected delay error of 10°. PMID:27322267

Joint Maximum Likelihood Time Delay Estimation of Unknown Event-Related Potential Signals for EEG Sensor Signal Quality Enhancement

Directory of Open Access Journals (Sweden)

Kyungsoo Kim

2016-06-01

Full Text Available Electroencephalograms (EEGs measure a brain signal that contains abundant information about the human brain function and health. For this reason, recent clinical brain research and brain computer interface (BCI studies use EEG signals in many applications. Due to the significant noise in EEG traces, signal processing to enhance the signal to noise power ratio (SNR is necessary for EEG analysis, especially for non-invasive EEG. A typical method to improve the SNR is averaging many trials of event related potential (ERP signal that represents a brain’s response to a particular stimulus or a task. The averaging, however, is very sensitive to variable delays. In this study, we propose two time delay estimation (TDE schemes based on a joint maximum likelihood (ML criterion to compensate the uncertain delays which may be different in each trial. We evaluate the performance for different types of signals such as random, deterministic, and real EEG signals. The results show that the proposed schemes provide better performance than other conventional schemes employing averaged signal as a reference, e.g., up to 4 dB gain at the expected delay error of 10°.

Fetal QRS extraction from abdominal recordings via model-based signal processing and intelligent signal merging

International Nuclear Information System (INIS)

Haghpanahi, Masoumeh; Borkholder, David A

2014-01-01

Noninvasive fetal ECG (fECG) monitoring has potential applications in diagnosing congenital heart diseases in a timely manner and assisting clinicians to make more appropriate decisions during labor. However, despite advances in signal processing and machine learning techniques, the analysis of fECG signals has still remained in its preliminary stages. In this work, we describe an algorithm to automatically locate QRS complexes in noninvasive fECG signals obtained from a set of four electrodes placed on the mother’s abdomen. The algorithm is based on an iterative decomposition of the maternal and fetal subspaces and filtering of the maternal ECG (mECG) components from the fECG recordings. Once the maternal components are removed, a novel merging technique is applied to merge the signals and detect the fetal QRS (fQRS) complexes. The algorithm was trained and tested on the fECG datasets provided by the PhysioNet/CinC challenge 2013. The final results indicate that the algorithm is able to detect fetal peaks for a variety of signals with different morphologies and strength levels encountered in clinical practice. (paper)

30 CFR 56.14219 - Brakeman signals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakeman signals. 56.14219 Section 56.14219... Safety Practices and Operational Procedures § 56.14219 Brakeman signals. When a train is under the direction of a brakeman and the train operator cannot clearly recognize the brakeman's signals, the train...

30 CFR 57.14219 - Brakeman signals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakeman signals. 57.14219 Section 57.14219... Equipment Safety Practices and Operational Procedures § 57.14219 Brakeman signals. When a train is under the direction of a brakeman and the train operator cannot clearly recognize the brakeman's signals, the train...

40 CFR 156.64 - Signal word.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Signal word. 156.64 Section 156.64... REQUIREMENTS FOR PESTICIDES AND DEVICES Human Hazard and Precautionary Statements § 156.64 Signal word. (a... signal word, reflecting the highest Toxicity Category (Category I is the highest toxicity category) to...

Digital signal processing an experimental approach

CERN Document Server

Engelberg, Shlomo

2008-01-01

Digital Signal Processing is a mathematically rigorous but accessible treatment of digital signal processing that intertwines basic theoretical techniques with hands-on laboratory instruction. Divided into three parts, the book covers various aspects of the digital signal processing (DSP) ""problem."" It begins with the analysis of discrete-time signals and explains sampling and the use of the discrete and fast Fourier transforms. The second part of the book???covering digital to analog and analog to digital conversion???provides a practical interlude in the mathematical content before Part II

Cross-talk in abscisic acid signaling

Science.gov (United States)

Fedoroff, Nina V.

2002-01-01

"Cross-talk" in hormone signaling reflects an organism's ability to integrate different inputs and respond appropriately, a crucial function at the heart of signaling network operation. Abscisic acid (ABA) is a plant hormone involved in bud and seed dormancy, growth regulation, leaf senescence and abscission, stomatal opening, and a variety of plant stress responses. This review summarizes what is known about ABA signaling in the control of stomatal opening and seed dormancy and provides an overview of emerging knowledge about connections between ABA, ethylene, sugar, and auxin synthesis and signaling.

Signalling chains with probe and adjust learning

Science.gov (United States)

Gosti, Giorgio

2018-04-01

Many models explain the evolution of signalling in repeated stage games on social networks, differently in this study each signalling game evolves a communication strategy to transmit information across the network. Specifically, I formalise signalling chain games as a generalisation of Lewis' signalling games, where a number of players are placed on a chain network and play a signalling game in which they have to propagate information across the network. I show that probe and adjust learning allows the system to develop communication conventions, but it may temporarily perturb the system out of conventions. Through simulations, I evaluate how long the system takes to evolve a signalling convention and the amount of time it stays in it. This discussion presents a mechanism in which simple players can evolve signalling across a social network without necessarily understanding the entire system.

Sensibility to Changes of Vibrational Modes of Excited Electron: Sum Frequency Signals Versus Difference Frequency Signals

International Nuclear Information System (INIS)

Gu Anna; Liang Xianting

2011-01-01

In this paper, we investigate a two electronic level system with vibrational modes coupled to a Brownian oscillator bath. The difference frequency generation (DFG) signals and sum frequency generation (SFG) signals are calculated. It is shown that, for the same model, the SFG signals are more sensitive than the DFG signals to the changes of the vibrational modes of the electronic two-level system. Because the SFG conversion efficiency can be improved by using the time-delay method, the findings in this paper predict that the SFG spectrum may probe the changes of the microstructure more effectively. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

33 CFR 118.130 - Fog signals.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Fog signals. 118.130 Section 118... LIGHTING AND OTHER SIGNALS § 118.130 Fog signals. On waterways where visibility is frequently reduced due to fog or other causes, the District Commander may require or authorize the installation of one or...

Social multimedia signals a signal processing approach to social network phenomena

CERN Document Server

Roy, Suman Deb

2014-01-01

This book provides a comprehensive coverage of the state-of-the-art in understanding media popularity and trends in online social networks through social multimedia signals. With insights from the study of popularity and sharing patterns of online media, trend spread in social media, social network analysis for multimedia and visualizing diffusion of media in online social networks. In particular, the book will address the following important issues: Understanding social network phenomena from a signal processing point of view; The existence and popularity of multimedia as shared and social me

Interaction of glutamate- and adenosine-induced decrease of acetylcholine quantal release at frog neuromuscular junction

Czech Academy of Sciences Publication Activity Database

Adámek, S.; Shakirzyanova, V.; Malomouzh, A. I.; Naumenko, N. V.; Vyskočil, František

2010-01-01

Roč. 59, č. 5 (2010), s. 803-810 ISSN 0862-8408 R&D Projects: GA AV ČR(CZ) IAA500110905; GA ČR GA202/09/0806 Institutional research plan: CEZ:AV0Z50110509 Keywords : Endplate potentials * Guanylyl cyclase Subject RIV: ED - Physiology Impact factor: 1.646, year: 2010

Glutamate Receptor Aptamers and ALS

Science.gov (United States)

2008-01-01

2003b; 42(42):12358–66. uthman H, Magnusson G. High efficiency polyoma DNA transfection of chloroquine treated cells. Nucl Acids Res 1983;11(5):1295...by acetylcholine and its analogues at the frog muscle end-plate, J. Physiol. 369, 501-557. 20. Auerbach, A., and Sachs, F. (1984) Single-channel

The LDC detector concept

Indian Academy of Sciences (India)

foresees a TPC with around 200 points measured along a track, and read out by a system of micro-pattern gas detectors. These novel gas amplification devices promise to provide a stable, reliable readout system, which can be realized with comparatively little material in the endplate compared to a traditional wire readout.

Působení atropinu a diazepamu na savčí nervosvalové ploténce – model jejich ochranného působení při otravě bojovými a zemědělskými anticholinesterázami

Czech Academy of Sciences Publication Activity Database

Vyskočil, František

2006-01-01

Roč. 55, č. 3 (2006), s. 111-113 ISSN 1210-6313 R&D Projects: GA AV ČR(CZ) IAA5011411; GA ČR(CZ) GA305/02/1333; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : anticholinesterase * endplate * muscle membrane Subject RIV: ED - Physiology

Signal processing for boiling noise detection

International Nuclear Information System (INIS)

Ledwidge, T.J.; Black, J.L.

1989-01-01

The present paper deals with investigations of acoustic signals from a boiling experiment performed on the KNS I loop at KfK Karlsruhe. Signals have been analysed in frequency as well as in time domain. Signal characteristics successfully used to detect the boiling process have been found in time domain. (author). 6 refs, figs

A signal theoretic introduction to random processes

CERN Document Server

Howard, Roy M

2015-01-01

A fresh introduction to random processes utilizing signal theory By incorporating a signal theory basis, A Signal Theoretic Introduction to Random Processes presents a unique introduction to random processes with an emphasis on the important random phenomena encountered in the electronic and communications engineering field. The strong mathematical and signal theory basis provides clarity and precision in the statement of results. The book also features:  A coherent account of the mathematical fundamentals and signal theory that underpin the presented material Unique, in-depth coverage of

Stable material modication with polymers incorporation for broad application in microfabrication

DEFF Research Database (Denmark)

Mednova, Olga

The aim of this thesis is to improve SU-8 fracture resistance in order to eliminate micro crack formation during fabrication of microelectromechanical system (MEMS). An amphiphilic block copolymer incorporation, as an efficient method of material toughening without changing its original properties...... analytical techniques. The second part of the thesis describes modified SU-8 blends. Thermal stability, structural organization, components interaction, hardness and brittleness of the composites are described. Finally, lithographic properties of modified SU-8 blends have been tested. Commercial SU-8...... and the modified blends demonstrate identically patternability and high aspect ratio structures can be obtained regardless of PEE-b-P2VP content. In conclusion, a recommendation of SU-8 modification with as little as 5 wt.% of PEE30-b-P2VP69 is made in order to avoid micro crack formation and its growth during...

Improved stochastic resonance algorithm for enhancement of signal-to-noise ratio of high-performance liquid chromatographic signal

International Nuclear Information System (INIS)

Xie Shaofei; Xiang Bingren; Deng Haishan; Xiang Suyun; Lu Jun

2007-01-01

Based on the theory of stochastic resonance, an improved stochastic resonance algorithm with a new criterion for optimizing system parameters to enhance signal-to-noise ratio (SNR) of HPLC/UV chromatographic signal for trace analysis was presented in this study. Compared with the conventional criterion in stochastic resonance, the proposed one can ensure satisfactory SNR as well as good peak shape of chromatographic peak in output signal. Application of the criterion to experimental weak signals of HPLC/UV was investigated and the results showed an excellent quantitative relationship between different concentrations and responses

Algorithm for removing scalp signals from functional near-infrared spectroscopy signals in real time using multidistance optodes.

Science.gov (United States)

Kiguchi, Masashi; Funane, Tsukasa

2014-11-01

A real-time algorithm for removing scalp-blood signals from functional near-infrared spectroscopy signals is proposed. Scalp and deep signals have different dependencies on the source-detector distance. These signals were separated using this characteristic. The algorithm was validated through an experiment using a dynamic phantom in which shallow and deep absorptions were independently changed. The algorithm for measurement of oxygenated and deoxygenated hemoglobins using two wavelengths was explicitly obtained. This algorithm is potentially useful for real-time systems, e.g., brain-computer interfaces and neuro-feedback systems.

Source of seismic signals

Energy Technology Data Exchange (ETDEWEB)

Frankovskii, B.A.; Khor' yakov, K.A.

1980-08-30

Patented is a source of seismic signals consisting of a shock generator with a basic low-voltage and auxillary high-voltage stator coils, a capacitive transformer and control switches. To increase the amplitude of signal excitation a condensor battery and auxillary commutator are introduced into the device, which are connected in parallel and serially into the circuit of the main low-voltage stator coil.

A Low-cost Multi-channel Analogue Signal Generator

CERN Document Server

Muller, F; Shen, W; Stamen, R

2009-01-01

A scalable multi-channel analogue signal generator is presented. It uses a commercial low-cost graphics card with multiple outputs in a standard PC as signal source. Each color signal serves as independent channel to generate an analogue signal. A custom-built external PCB was developed to adjust the graphics card output voltage levels for a specific task, which needed differential signals. The system furthermore comprises a software package to program the signal shape. The implementation of the signal generator is presented as well as an application where it was successfully utilized.

Pleiotrophin Signaling Through PTNR in Breast Cancer

National Research Council Canada - National Science Library

Powers, Ciaron

2001-01-01

... of intracellular signaling cascades. The pleiotrophin signaling pathway is known to be important in angiogenesis and breast cancer growth, but the exact mechanisms of pleiotrophin signaling remain undefined...

Mitochondrial Energy and Redox Signaling in Plants

Science.gov (United States)

Schwarzländer, Markus

2013-01-01

Abstract Significance: For a plant to grow and develop, energy and appropriate building blocks are a fundamental requirement. Mitochondrial respiration is a vital source for both. The delicate redox processes that make up respiration are affected by the plant's changing environment. Therefore, mitochondrial regulation is critically important to maintain cellular homeostasis. This involves sensing signals from changes in mitochondrial physiology, transducing this information, and mounting tailored responses, by either adjusting mitochondrial and cellular functions directly or reprogramming gene expression. Recent Advances: Retrograde (RTG) signaling, by which mitochondrial signals control nuclear gene expression, has been a field of very active research in recent years. Nevertheless, no mitochondrial RTG-signaling pathway is yet understood in plants. This review summarizes recent advances toward elucidating redox processes and other bioenergetic factors as a part of RTG signaling of plant mitochondria. Critical Issues: Novel insights into mitochondrial physiology and redox-regulation provide a framework of upstream signaling. On the other end, downstream responses to modified mitochondrial function have become available, including transcriptomic data and mitochondrial phenotypes, revealing processes in the plant that are under mitochondrial control. Future Directions: Drawing parallels to chloroplast signaling and mitochondrial signaling in animal systems allows to bridge gaps in the current understanding and to deduce promising directions for future research. It is proposed that targeted usage of new technical approaches, such as quantitative in vivo imaging, will provide novel leverage to the dissection of plant mitochondrial signaling. Antioxid. Redox Signal. 18, 2122–2144. PMID:23234467

The LISA zero-signal solution

International Nuclear Information System (INIS)

Tinto, Massimo; Larson, Shane L

2005-01-01

We derive a time-delay interferometric (TDI) combination that has zero-response to a gravitational wave signal. This combination, which we have called the zero-signal solution, is a two-parameter family of linear combinations of the generators of the TDI space that has null gravitational wave response when its two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the zero-signal solution does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind

Statistical theory of signal detection

CERN Document Server

Helstrom, Carl Wilhelm; Costrell, L; Kandiah, K

1968-01-01

Statistical Theory of Signal Detection, Second Edition provides an elementary introduction to the theory of statistical testing of hypotheses that is related to the detection of signals in radar and communications technology. This book presents a comprehensive survey of digital communication systems. Organized into 11 chapters, this edition begins with an overview of the theory of signal detection and the typical detection problem. This text then examines the goals of the detection system, which are defined through an analogy with the testing of statistical hypotheses. Other chapters consider

Analog and mixed-signal electronics

CERN Document Server

Stephan, Karl

2015-01-01

A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

Subjective Evaluation of Audiovisual Signals

Directory of Open Access Journals (Sweden)

F. Fikejz

2010-01-01

Full Text Available This paper deals with subjective evaluation of audiovisual signals, with emphasis on the interaction between acoustic and visual quality. The subjective test is realized by a simple rating method. The audiovisual signal used in this test is a combination of images compressed by JPEG compression codec and sound samples compressed by MPEG-1 Layer III. Images and sounds have various contents. It simulates a real situation when the subject listens to compressed music and watches compressed pictures without the access to original, i.e. uncompressed signals.

On Generalized Fractional Differentiator Signals

Directory of Open Access Journals (Sweden)

Hamid A. Jalab

2013-01-01

Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.

Symbolic transfer entropy-based premature signal analysis

International Nuclear Information System (INIS)

Wang Jun; Yu Zheng-Feng

2012-01-01

In this paper, we use symbolic transfer entropy to study the coupling strength between premature signals. Numerical experiments show that three types of signal couplings are in the same direction. Among them, normal signal coupling is the strongest, followed by that of premature ventricular contractions, and that of atrial premature beats is the weakest. The T test shows that the entropies of the three signals are distinct. Symbolic transfer entropy requires less data, can distinguish the three types of signals and has very good computational efficiency. (interdisciplinary physics and related areas of science and technology)

Signal-regulated systems and networks

CSIR Research Space (South Africa)

Van Zyl, TL

2010-07-01

Full Text Available The article presents the use of signal regulatory networks (SRNs), a biologically inspired model based on gene regulatory networks. SRNs are a way of understanding a class of self-organizing IT systems, signal-regulated systems (SRSs). This article...

Analysis of acoustic sound signal for ONB measurement

International Nuclear Information System (INIS)

Park, S. J.; Kim, H. I.; Han, K. Y.; Chai, H. T.; Park, C.

2003-01-01

The onset of nucleate boiling (ONB) was measured in a test fuel bundle composed of several fuel element simulators (FES) by analysing the aquatic sound signals. In order measure ONBs, a hydrophone, a pre-amplifier, and a data acquisition system to acquire/process the aquatic signal was prepared. The acoustic signal generated in the coolant is converted to the current signal through the microphone. When the signal is analyzed in the frequency domain, each sound signal can be identified according to its origin of sound source. As the power is increased to a certain degree, a nucleate boiling is started. The frequent formation and collapse of the void bubbles produce sound signal. By measuring this sound signal one can pinpoint the ONB. Since the signal characteristics is identical for different mass flow rates, this method can be applicable for ascertaining ONB

Modularized Smad-regulated TGFβ signaling pathway.

Science.gov (United States)

Li, Yongfeng; Wang, Minli; Carra, Claudio; Cucinotta, Francis A

2012-12-01

The transforming Growth Factor β (TGFβ) signaling pathway is a prominent regulatory signaling pathway controlling various important cellular processes. TGFβ signaling can be induced by several factors including ionizing radiation. The pathway is regulated in a negative feedback loop through promoting the nuclear import of the regulatory Smads and a subsequent expression of inhibitory Smad7, that forms ubiquitin ligase with Smurf2, targeting active TGFβ receptors for degradation. In this work, we proposed a mathematical model to study the Smad-regulated TGFβ signaling pathway. By modularization, we are able to analyze mathematically each component subsystem and recover the nonlinear dynamics of the entire network system. Meanwhile the excitability, a common feature observed in the biological systems, in the TGFβ signaling pathway is discussed and supported as well by numerical simulation, indicating the robustness of the model. Published by Elsevier Inc.

Signal enhancement by spectral equalization of high frequency broadband signals transmitted through optical fibers

International Nuclear Information System (INIS)

Lyons, P.B.; Ogle, J.W.; Holzman, M.A.

1980-01-01

A new technique is discussed for enhancing the bandwidth and intensity of high frequency (> 1 GHz) analog, spectrally broad (40 nm) signals transmitted through one kilometer of optical fiber. The existing method for bandwidth enhancement of such a signal uses a very narrow (approx. 1 nm) filter between the fiber and detector to limit bandwidth degradation due to material dispersion. Using this method, most of the available optical intensity is rejected and lost. This new technique replaces the narrow-band filter with a spectral equalizer device which uses a reflection grating to disperse the input signal spectrum and direct it onto a linear array of fibers

Barcoding of GPCR trafficking and signaling through the various trafficking roadmaps by compartmentalized signaling networks.

Science.gov (United States)

Bahouth, Suleiman W; Nooh, Mohammed M

2017-08-01

Proper signaling by G protein coupled receptors (GPCR) is dependent on the specific repertoire of transducing, enzymatic and regulatory kinases and phosphatases that shape its signaling output. Activation and signaling of the GPCR through its cognate G protein is impacted by G protein-coupled receptor kinase (GRK)-imprinted "barcodes" that recruit β-arrestins to regulate subsequent desensitization, biased signaling and endocytosis of the GPCR. The outcome of agonist-internalized GPCR in endosomes is also regulated by sequence motifs or "barcodes" within the GPCR that mediate its recycling to the plasma membrane or retention and eventual degradation as well as its subsequent signaling in endosomes. Given the vast number of diverse sequences in GPCR, several trafficking mechanisms for endosomal GPCR have been described. The majority of recycling GPCR, are sorted out of endosomes in a "sequence-dependent pathway" anchored around a type-1 PDZ-binding module found in their C-tails. For a subset of these GPCR, a second "barcode" imprinted onto specific GPCR serine/threonine residues by compartmentalized kinase networks was required for their efficient recycling through the "sequence-dependent pathway". Mutating the serine/threonine residues involved, produced dramatic effects on GPCR trafficking, indicating that they played a major role in setting the trafficking itinerary of these GPCR. While endosomal SNX27, retromer/WASH complexes and actin were required for efficient sorting and budding of all these GPCR, additional proteins were required for GPCR sorting via the second "barcode". Here we will review recent developments in GPCR trafficking in general and the human β 1 -adrenergic receptor in particular across the various trafficking roadmaps. In addition, we will discuss the role of GPCR trafficking in regulating endosomal GPCR signaling, which promote biochemical and physiological effects that are distinct from those generated by the GPCR signal transduction

Mechanism of inhibition of growth hormone receptor signaling by suppressor of cytokine signaling proteins

DEFF Research Database (Denmark)

Hansen, J A; Lindberg, K; Hilton, D J

1999-01-01

In this study we have investigated the role of suppressor of cytokine signaling (SOCS) proteins in GH receptor-mediated signaling. GH-induced transcription was inhibited by SOCS-1 and SOCS-3, while SOCS-2 and cytokine inducible SH2-containing protein (CIS) had no effect By using chimeric SOCS pro...

Instruction of hematopoietic lineage choice by cytokine signaling

Energy Technology Data Exchange (ETDEWEB)

Endele, Max; Etzrodt, Martin; Schroeder, Timm, E-mail: timm.schroeder@bsse.ethz.ch

2014-12-10

Hematopoiesis is the cumulative consequence of finely tuned signaling pathways activated through extrinsic factors, such as local niche signals and systemic hematopoietic cytokines. Whether extrinsic factors actively instruct the lineage choice of hematopoietic stem and progenitor cells or are only selectively allowing survival and proliferation of already intrinsically lineage-committed cells has been debated over decades. Recent results demonstrated that cytokines can instruct lineage choice. However, the precise function of individual cytokine-triggered signaling molecules in inducing cellular events like proliferation, lineage choice, and differentiation remains largely elusive. Signal transduction pathways activated by different cytokine receptors are highly overlapping, but support the production of distinct hematopoietic lineages. Cellular context, signaling dynamics, and the crosstalk of different signaling pathways determine the cellular response of a given extrinsic signal. New tools to manipulate and continuously quantify signaling events at the single cell level are therefore required to thoroughly interrogate how dynamic signaling networks yield a specific cellular response. - Highlights: • Recent studies provided definite proof for lineage-instructive action of cytokines. • Signaling pathways involved in hematopoietic lineage instruction remain elusive. • New tools are emerging to quantitatively study dynamic signaling networks over time.

Application of wavelet transform in seismic signal processing

International Nuclear Information System (INIS)

Ghasemi, M. R.; Mohammadzadeh, A.; Salajeghe, E.

2005-01-01

Wavelet transform is a new tool for signal analysis which can perform a simultaneous signal time and frequency representations. Under Multi Resolution Analysis, one can quickly determine details for signals and their properties using Fast Wavelet Transform algorithms. In this paper, for a better physical understanding of a signal and its basic algorithms, Multi Resolution Analysis together with wavelet transforms in a form of Digital Signal Processing will be discussed. For a Seismic Signal Processing, sets of Orthonormal Daubechies Wavelets are suggested. when dealing with the application of wavelets in SSP, one may discuss about denoising from the signal and data compression existed in the signal, which is important in seismic signal data processing. Using this techniques, EL-Centro and Nagan signals were remodeled with a 25% of total points, resulted in a satisfactory results with an acceptable error drift. Thus a total of 1559 and 2500 points for EL-centro and Nagan seismic curves each, were reduced to 389 and 625 points respectively, with a very reasonable error drift, details of which are recorded in the paper. Finally, the future progress in signal processing, based on wavelet theory will be appointed

The function of endocytosis in Wnt signaling.

Science.gov (United States)

Brunt, Lucy; Scholpp, Steffen

2018-03-01

Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.

SignalSpider: Probabilistic pattern discovery on multiple normalized ChIP-Seq signal profiles

KAUST Repository

Wong, Kachun

2014-09-05

Motivation: Chromatin immunoprecipitation (ChIP) followed by high-throughput sequencing (ChIP-Seq) measures the genome-wide occupancy of transcription factors in vivo. Different combinations of DNA-binding protein occupancies may result in a gene being expressed in different tissues or at different developmental stages. To fully understand the functions of genes, it is essential to develop probabilistic models on multiple ChIP-Seq profiles to decipher the combinatorial regulatory mechanisms by multiple transcription factors. Results: In this work, we describe a probabilistic model (SignalSpider) to decipher the combinatorial binding events of multiple transcription factors. Comparing with similar existing methods, we found SignalSpider performs better in clustering promoter and enhancer regions. Notably, SignalSpider can learn higher-order combinatorial patterns from multiple ChIP-Seq profiles. We have applied SignalSpider on the normalized ChIP-Seq profiles from the ENCODE consortium and learned model instances. We observed different higher-order enrichment and depletion patterns across sets of proteins. Those clustering patterns are supported by Gene Ontology (GO) enrichment, evolutionary conservation and chromatin interaction enrichment, offering biological insights for further focused studies. We also proposed a specific enrichment map visualization method to reveal the genome-wide transcription factor combinatorial patterns from the models built, which extend our existing fine-scale knowledge on gene regulation to a genome-wide level. Availability and implementation: The matrix-algebra-optimized executables and source codes are available at the authors\\' websites: http://www.cs.toronto.edu/∼wkc/SignalSpider. Contact: Supplementary information: Supplementary data are available at Bioinformatics online.

Dysphagia Screening: Contributions of Cervical Auscultation Signals and Modern Signal-Processing Techniques

Science.gov (United States)

Dudik, Joshua M.; Coyle, James L.

2015-01-01

Cervical auscultation is the recording of sounds and vibrations caused by the human body from the throat during swallowing. While traditionally done by a trained clinician with a stethoscope, much work has been put towards developing more sensitive and clinically useful methods to characterize the data obtained with this technique. The eventual goal of the field is to improve the effectiveness of screening algorithms designed to predict the risk that swallowing disorders pose to individual patients’ health and safety. This paper provides an overview of these signal processing techniques and summarizes recent advances made with digital transducers in hopes of organizing the highly varied research on cervical auscultation. It investigates where on the body these transducers are placed in order to record a signal as well as the collection of analog and digital filtering techniques used to further improve the signal quality. It also presents the wide array of methods and features used to characterize these signals, ranging from simply counting the number of swallows that occur over a period of time to calculating various descriptive features in the time, frequency, and phase space domains. Finally, this paper presents the algorithms that have been used to classify this data into ‘normal’ and ‘abnormal’ categories. Both linear as well as non-linear techniques are presented in this regard. PMID:26213659

Smoke Signal or Smoke Screen?

DEFF Research Database (Denmark)

Vergne, Jean-Philippe; Wernicke, Georg; Brenner, Steffen

This paper explains the amount of disapproval faced by firms that overpay their CEO by integrating signaling and categorization theories. We argue that, in contexts characterized by intense scrutiny, ambivalent signals sent by firms suspend categorization by stakeholders, leading to further disap...

Signals of Opportunity Navigation Using Wi-Fi Signals

Science.gov (United States)

2011-03-24

Multiplexed Signals of Opportunity. Master’s Thesis, Air Force Institute of Technology, 2007. 33. Wiles, Charles. “Introducing the Gears Geolocation ... API for All Laptop WiFi Users”, October 2008. URL http://googlecode.blogspot.com. 88 REPORT DOCUMENTATION PAGE Form ApprovedOMB No. 0704–0188 The public

Distortions in processed signals and their application in electronic design - III: An automated generator of communication jamming signals

International Nuclear Information System (INIS)

Njau, E.C.

1987-10-01

We describe the design and operational features of a simple electronic circuit that is capable of automatically generating a narrow bandwidth jamming signal around each frequency signal received from target transmitters. It is noted that jamming based upon this circuit is fairly difficult to nullify using some of the conventional ''counter jamming'' strategies since in this case the jamming signals are flexibly locked onto the spectral components of the received signals. (author). 3 refs, 3 figs

Analysis of signal acquisition in GPS receiver software

Directory of Open Access Journals (Sweden)

Vlada S. Sokolović

2011-01-01

Full Text Available This paper presents a critical analysis of the flow signal processing carried out in GPS receiver software, which served as a basis for a critical comparison of different signal processing architectures within the GPS receiver. It is possible to achieve Increased flexibility and reduction of GPS device commercial costs, including those of mobile devices, by using radio technology software (SDR, Software Defined Radio. The SDR application can be realized when certain hardware components in a GPS receiver are replaced. Signal processing in the SDR is implemented using a programmable DSP (Digital Signal Processing or FPGA (Field Programmable Gate Array circuit, which allows a simple change of digital signal processing algorithms and a simple change of the receiver parameters. The starting point of the research is the signal generated on the satellite the structure of which is shown in the paper. Based on the GPS signal structure, a receiver is realized with a task to extract an appropriate signal from the spectrum and detect it. Based on collected navigation data, the receiver calculates the position of the end user. The signal coming from the satellite may be at the carrier frequencies of L1 and L2. Since the SPS is used in the civil service, all the tests shown in the work were performed on the L1 signal. The signal coming to the receiver is generated in the spread spectrum technology and is situated below the level of noise. Such signals often interfere with signals from the environment which presents a difficulty for a receiver to perform proper detection and signal processing. Therefore, signal processing technology is continually being improved, aiming at more accurate and faster signal processing. All tests were carried out on a signal acquired from the satellite using the SE4110 input circuit used for filtering, amplification and signal selection. The samples of the received signal were forwarded to a computer for data post processing, i. e

Improvement of neuromuscular synaptic phenotypes without enhanced survival and motor function in severe spinal muscular atrophy mice selectively rescued in motor neurons.

Directory of Open Access Journals (Sweden)

Ximena Paez-Colasante

Full Text Available In the inherited childhood neuromuscular disease spinal muscular atrophy (SMA, lower motor neuron death and severe muscle weakness result from the reduction of the ubiquitously expressed protein survival of motor neuron (SMN. Although SMA mice recapitulate many features of the human disease, it has remained unclear if their short lifespan and motor weakness are primarily due to cell-autonomous defects in motor neurons. Using Hb9(Cre as a driver, we selectively raised SMN expression in motor neurons in conditional SMAΔ7 mice. Unlike a previous study that used choline acetyltransferase (ChAT(Cre+ as a driver on the same mice, and another report that used Hb9(Cre as a driver on a different line of conditional SMA mice, we found no improvement in survival, weight, motor behavior and presynaptic neurofilament accumulation. However, like in ChAT(Cre+ mice, we detected rescue of endplate size and mitigation of neuromuscular junction (NMJ denervation status. The rescue of endplate size occurred in the absence of an increase in myofiber size, suggesting endplate size is determined by the motor neuron in these animals. Real time-PCR showed that the expression of spinal cord SMN transcript was sharply reduced in Hb9(Cre+ SMA mice relative to ChAT(Cre+ SMA mice. This suggests that our lack of overall phenotypic improvement is most likely due to an unexpectedly poor recombination efficiency driven by Hb9(Cre . Nonetheless, the low levels of SMN were sufficient to rescue two NMJ structural parameters indicating that these motor neuron cell autonomous phenotypes are very sensitive to changes in motoneuronal SMN levels. Our results directly suggest that even those therapeutic interventions with very modest effects in raising SMN in motor neurons may provide mitigation of neuromuscular phenotypes in SMA patients.

Wnt signaling in triple-negative breast cancer

Science.gov (United States)

Pohl, SÖ-G; Brook, N; Agostino, M; Arfuso, F; Kumar, A P; Dharmarajan, A

2017-01-01

Wnt signaling regulates a variety of cellular processes, including cell fate, differentiation, proliferation and stem cell pluripotency. Aberrant Wnt signaling is a hallmark of many cancers. An aggressive subtype of breast cancer, known as triple-negative breast cancer (TNBC), demonstrates dysregulation in canonical and non-canonical Wnt signaling. In this review, we summarize regulators of canonical and non-canonical Wnt signaling, as well as Wnt signaling dysfunction that mediates the progression of TNBC. We review the complex molecular nature of TNBC and the emerging therapies that are currently under investigation for the treatment of this disease. PMID:28368389

Signal processing: opportunities for superconductive circuits

International Nuclear Information System (INIS)

Ralston, R.W.

1985-01-01

Prime motivators in the evolution of increasingly sophisticated communication and detection systems are the needs for handling ever wider signal bandwidths and higher data processing speeds. These same needs drive the development of electronic device technology. Until recently the superconductive community has been tightly focused on digital devices for high speed computers. The purpose of this paper is to describe opportunities and challenges which exist for both analog and digital devices in a less familiar area, that of wideband signal processing. The function and purpose of analog signal-processing components, including matched filters, correlators and Fourier transformers, will be described and examples of superconductive implementations given. A canonic signal-processing system is then configured using these components in combination with analog/digital converters and digital output circuits to highlight the important issues of dynamic range, accuracy and equivalent computation rate. Superconductive circuits hold promise for processing signals of 10-GHz bandwidth. Signal processing systems, however, can be properly designed and implemented only through a synergistic combination of the talents of device physicists, circuit designers, algorithm architects and system engineers. An immediate challenge to the applied superconductivity community is to begin sharing ideas with these other researchers

Wnt signaling inhibits CTL memory programming.

Science.gov (United States)

Xiao, Zhengguo; Sun, Zhifeng; Smyth, Kendra; Li, Lei

2013-12-01

Induction of functional CTLs is one of the major goals for vaccine development and cancer therapy. Inflammatory cytokines are critical for memory CTL generation. Wnt signaling is important for CTL priming and memory formation, but its role in cytokine-driven memory CTL programming is unclear. We found that wnt signaling inhibited IL-12-driven CTL activation and memory programming. This impaired memory CTL programming was attributed to up-regulation of eomes and down-regulation of T-bet. Wnt signaling suppressed the mTOR pathway during CTL activation, which was different to its effects on other cell types. Interestingly, the impaired memory CTL programming by wnt was partially rescued by mTOR inhibitor rapamycin. In conclusion, we found that crosstalk between wnt and the IL-12 signaling inhibits T-bet and mTOR pathways and impairs memory programming which can be recovered in part by rapamycin. In addition, direct inhibition of wnt signaling during CTL activation does not affect CTL memory programming. Therefore, wnt signaling may serve as a new tool for CTL manipulation in autoimmune diseases and immune therapy for certain cancers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Roles of STATs signaling in cardiovascular diseases.

Science.gov (United States)