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Sample records for proximal initial segment

  1. Proximity graphs based multi-scale image segmentation

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    Skurikhin, Alexei N [Los Alamos National Laboratory

    2008-01-01

    We present a novel multi-scale image segmentation approach based on irregular triangular and polygonal tessellations produced by proximity graphs. Our approach consists of two separate stages: polygonal seeds generation followed by an iterative bottom-up polygon agglomeration into larger chunks. We employ constrained Delaunay triangulation combined with the principles known from the visual perception to extract an initial ,irregular polygonal tessellation of the image. These initial polygons are built upon a triangular mesh composed of irregular sized triangles and their shapes are ad'apted to the image content. We then represent the image as a graph with vertices corresponding to the polygons and edges reflecting polygon relations. The segmentation problem is then formulated as Minimum Spanning Tree extraction. We build a successive fine-to-coarse hierarchy of irregular polygonal grids by an iterative graph contraction constructing Minimum Spanning Tree. The contraction uses local information and merges the polygons bottom-up based on local region-and edge-based characteristics.

  2. Lactate oxidation by three segments of the rabbit proximal tubule

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    Brand, P.H.; Taylor, B.B.

    1986-09-01

    Oxidation of (U/sup 14/C)lactate to /sup 14/CO/sub 2/ was measured in vitro, in nonperfused anatomically defined segments of rabbit proximal tubule (S1, proximal convoluted, and S2 and S3, proximal straight tubules). The rate of lactate oxidation was similar in S2 and S3 segments, and within the range of lactate oxidation rates measured in vivo. In contrast, the oxidation rate of S1 segments was significantly lower than that of S2 or S3. In proximal straight tubules, lactate oxidation was inhibited by incubation at 0/sup 0/C, or by application of 1 mM ouabain. To determine if the rate of transepithelial transport affected the rate of lactate oxidation, lactate oxidation was measured in proximal straight tubules after the lumen had been opened by perfusion with Ringer's containing 10 mM polyethylene glycol. No difference in lactate oxidation rate was observed between tubules with patent lumina and nonperfused tubules. These results suggest that the various segments of the renal proximal tubule have difference metabolic characteristics, and that the rate of substrate oxidation is related to the activity of the Na/sup +/, K/sup +/-ATPase.

  3. Functionally induced changes in water transport in the proximal tubule segment of rat kidneys

    DEFF Research Database (Denmark)

    Faarup, Poul; von Holstein-Rathlou, Niels-Henrik; Nørgaard, Tove

    2011-01-01

    To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure of the pr...... segment, representing a structural background for the essential transport of water from the proximal tubules to the peritubular capillaries.......To eliminate freezing artifacts in the proximal tubule cells, two cryotechniques were applied to normal rat kidneys, ie, freeze substitution and special freeze drying. In addition, salt depletion and salt loading were applied to groups of rats to evaluate whether the segmental structure...

  4. TREATMENT OF INTRA-ATICULAR FRACTURES OF THE PROXIMAL SEGMENT OF THE TIBIA

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    V. V. Klyuchevsky

    2010-01-01

    Full Text Available The experience of treatment of patients with intra-articular fractures of proximal segment of the tibia is presented. For improvement of diagnostics the body section radiography was used. Conservative methods were applied in 146 patients, surgical - in 202. The best results were achieved on application of dampening skeletal traction - 88,2%.

  5. A new anastomosis technique for intestinal diseases with proximal dilated segments

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    Metin Gündüz

    2016-01-01

    Full Text Available A number of techniques have been described for intestinal anastomosis. We describe a different, simple, and safe technique that can be used in patients with intestinal diseases, such as jejunoileal atresia and perforation that has proximal dilated segments. In this technique, an atraumatic bowel clamp was applied on the proximal dilated bowel at a 90° angle. In the narrow distal segment, we resected the bowel at a 0° angle and continued at a 30° angle from the antimesenteric side. Finally, a two-layer interrupted anastomosis was performed. We applied this technique to a 31-day-old patient who had a divided jejunostomy due to malrotation and perforation with a proximal dilated bowel. Neither anastomotic complications nor feeding and passage problems were seen postoperatively.

  6. Sport-Specific Training Targeting the Proximal Segments and Throwing Velocity in Collegiate Throwing Athletes.

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    Palmer, Thomas; Uhl, Timothy L; Howell, Dana; Hewett, Timothy E; Viele, Kert; Mattacola, Carl G

    2015-06-01

    The ability to generate, absorb, and transmit forces through the proximal segments of the pelvis, spine, and trunk has been proposed to influence sport performance, yet traditional training techniques targeting the proximal segments have had limited success improving sport-specific performance. To investigate the effects of a traditional endurance-training program and a sport-specific power-training program targeting the muscles that support the proximal segments and throwing velocity. Randomized controlled clinical trial. University research laboratory and gymnasium. A total of 46 (age = 20 ± 1.3 years, height = 175.7 ± 8.7 cm) healthy National Collegiate Athletic Association Division III female softball (n = 17) and male baseball (n = 29) players. Blocked stratification for sex and position was used to randomly assign participants to 1 of 2 training groups for 7 weeks: a traditional endurance-training group (ET group; n = 21) or a power-stability-training group (PS group; n = 25). Mean Outcome Measure(s) : The change score in peak throwing velocity (km/h) normalized for body weight (BW; kilograms) and change score in tests that challenge the muscles of the proximal segments normalized for BW (kilograms). We used 2-tailed independent-samples t tests to compare differences between the change scores. The peak throwing velocity (ET group = 0.01 ± 0.1 km/h/kg of BW, PS group = 0.08 ± 0.03 km/h/kg of BW; P sport-specific training regimen targeting the proximal segments.

  7. Effect of cisplatin on proximal convoluted and straight segments of the rat kidney

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    Daugaard, G; Holstein-Rathlou, N H; Leyssac, P P

    1988-01-01

    lithium clearance (CLi/Cin) and e-TT/OT was observed (from 270 +/- 32 to 387 +/- 60 microliters/min/g kidney weight, 0.202 +/- 0.03 to 0.340 +/- 0.06 and 0.415 +/- 0.02 to 0.497 +/- 0.02, respectively). These increases indicate an increased fluid delivery from both the proximal straight segment...

  8. What Contributes to the Split-Attention Effect? The Role of Text Segmentation, Picture Labelling, and Spatial Proximity

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    Florax, Mareike; Ploetzner, Rolf

    2010-01-01

    In the split-attention effect spatial proximity is frequently considered to be pivotal. The transition from a spatially separated to a spatially integrated format not only involves changes in spatial proximity, but commonly necessitates text segmentation and picture labelling as well. In an experimental study, we investigated the influence of…

  9. Comparison of Lower Limb Segments Kinematics in a Taekwondo Kick. An Approach to the Proximal to Distal Motion

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    Estevan Isaac

    2015-09-01

    Full Text Available In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane of lower limb segments (thigh, shank and foot, and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values, with the distal segment taking the longest to reach this peak velocity (p < 0.01. Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01. It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern.

  10. Treatment of an open distal tibia fracture with segmental bone loss in combination with a closed proximal tibia fracture: a case report.

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    Park, Jin; Yang, Kyu Hyun

    2012-08-01

    The treatment of open distal tibia fractures remains challenging, particularly when the fracture is infected and involves segmental bone loss. We report the case of a 38-year-old man who sustained an open distal tibiofibular fracture with segmental bone loss and a closed proximal tibial fracture. The fractures were initially fixed with a temporary external fixator. The open distal tibial fracture was infected, and the skin was covered after the wound became culture negative. The tibia was then internally transported with a ring external fixator; the closed fracture of the proximal tibia served as the corticotomy for internal transport without conventional corticotomy. After 5 cm internal transport, the docking site of the distal tibia was fixed with a locking plate and autogenous cancellous bone graft. Bone graft was also used to the distal tibiofibular space to achieve distal tibiofibular synostosis. We describe one treatment option for an infected open fracture of the distal tibia with segmental bone loss that is accompanied by a closed fracture of the proximal tibia. This method can treat two fractures simultaneously.

  11. In vitro direct shoot regeneration from proximal, middle and distal segment of Coleus forskohlii leaf explants.

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    Krishna, Gaurav; Sairam Reddy, P; Anoop Nair, N; Ramteke, P W; Bhattacharya, P S

    2010-04-01

    Coleus forskohlii is an endangered multipurpose medicinal plant that has widespread applications. In spite of this, there have been few attempts to propagate its cultivation in India. The present communication presents an in vitro rapid regeneration method using leaf explants of Coleus forskohlii through direct organogenesis. Leaf explants that were excised into three different segments i.e. proximal (P), middle (M) and distal (D) were cultured on Murashige and Skoog (MS) basal medium supplemented with cytokinins. MS Media containing 5.0 mg L(-1) BAP (6-Benzylaminopurine) promoted regeneration of multiple shoots through direct organogenesis from the leaf, which were further elongated on MS media augmented with 0.1 mg L-1 BAP and 0.1 mg L(-1) IAA (Indole-3-acetic acid), cytokinin and auxin combination. Regenerated and elongated shoots, when transferred to ose resulted in profuse rooting plants that were transferred to soil after acclimatization and maintained in a green house. The current protocol offers a direct, mass propagation method bypassing the callus phase of C. forskohlii and is suitable for conservation, large-scale commercial cultivation, and genetic transformation with agronomically desirable traits.

  12. Transport of salicylate in proximal tubule (S sub 2 segment) isolated from rabbit kidney

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    Schild, L.; Roch-Ramel, F. (Institut de Pharmacologie de l' Universite de Lausanne (Switzerland))

    1988-04-01

    The secretory and the reabsorptive transport of salicylate was studied in the isolated and perfused rabbit proximal tubule (S{sub 2} segment). Salicylate secretion (J{sub sal}{sup b{yields}l}) fulfilled the criteria for a carrier-mediated transport system: J{sub sal}{sup b{yields}l} was saturable, was reversibly inhibited by probenecid, and occurred against a concentration gradient. The K{sub m} and V{sub max} for this secretory transport were 80 {mu}M and 3,200 fmol{center dot}min{sup {minus}1}{center dot}mm{sup {minus}1}, respectively. At luminal pH of 7.4 and 6.6, salicylate reabsorption (J{sub sal}{sup l{yields}b}) was low. J{sub sal}{sup l{yields}b} was stimulated by increasing the bath Pco{sub 2} or by removing basolateral HCO{sub 3}{sup {minus}}; J{sub sal}{sup l{yields}b} was inhibited by ethoxyzolamide and by SITS in the bath. The results indicate that salicylate reabsorption depends on H{sup +} secretion, consistent with reabsorption by simple nonionic diffusion. When salicylate was present in the lumen only, J{sub sal}{sup l{yields}b} increased after inhibition of the secretory transport by adding ouabain or probenecid in the bath or by lowering the bath temperature. These results are compatible with luminal recycling of salicylate, and suggest the presence of a mediated secretory transporter located at the luminal membrane.

  13. Proximate Units in Word Production: Phonological Encoding Begins with Syllables in Mandarin Chinese but with Segments in English

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    O'Seaghdha, Padraig G.; Chen, Jenn-Yeu; Chen, Train-Min

    2010-01-01

    In Mandarin Chinese, speakers benefit from fore-knowledge of what the first syllable but not of what the first phonemic segment of a disyllabic word will be (Chen, J.-Y., Chen, T.-M. & Dell, 2002), contrasting with findings in English, Dutch, and other Indo-European languages, and challenging the generality of current theories of word production. In this article, we extend the evidence for the language difference by showing that failure to prepare onsets in Mandarin (Experiment 1) applies even to simple monosyllables (Experiments 2-4), and confirm the contrast with English for comparable materials (Experiments 5, 6). We also provide new evidence that Mandarin speakers do reliably prepare tonally unspecified phonological syllables (Experiment 7). To account for these patterns, we propose a language general proximate units principle whereby intentional preparation for speech as well as phonological-lexical coordination are grounded at the first phonological level below the word at which explicit unit selection occurs. The language difference arises because syllables are proximate units in Mandarin Chinese, whereas segments are proximate in English and other Indo-European languages. The proximate units perspective reconciles the aspiration toward a language general account of word production with the reality of substantial cross-linguistic differences. PMID:20149354

  14. Action potential generation requires a high sodium channel density in the axon initial segment.

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    Kole, Maarten H P; Ilschner, Susanne U; Kampa, Björn M; Williams, Stephen R; Ruben, Peter C; Stuart, Greg J

    2008-02-01

    The axon initial segment (AIS) is a specialized region in neurons where action potentials are initiated. It is commonly assumed that this process requires a high density of voltage-gated sodium (Na(+)) channels. Paradoxically, the results of patch-clamp studies suggest that the Na(+) channel density at the AIS is similar to that at the soma and proximal dendrites. Here we provide data obtained by antibody staining, whole-cell voltage-clamp and Na(+) imaging, together with modeling, which indicate that the Na(+) channel density at the AIS of cortical pyramidal neurons is approximately 50 times that in the proximal dendrites. Anchoring of Na(+) channels to the cytoskeleton can explain this discrepancy, as disruption of the actin cytoskeleton increased the Na(+) current measured in patches from the AIS. Computational models required a high Na(+) channel density (approximately 2,500 pS microm(-2)) at the AIS to account for observations on action potential generation and backpropagation. In conclusion, action potential generation requires a high Na(+) channel density at the AIS, which is maintained by tight anchoring to the actin cytoskeleton.

  15. Automatic initial and final segmentation in cleft palate speech of Mandarin speakers

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    Liu, Yin; Yin, Heng; Zhang, Junpeng; Zhang, Jing; Zhang, Jiang

    2017-01-01

    The speech unit segmentation is an important pre-processing step in the analysis of cleft palate speech. In Mandarin, one syllable is composed of two parts: initial and final. In cleft palate speech, the resonance disorders occur at the finals and the voiced initials, while the articulation disorders occur at the unvoiced initials. Thus, the initials and finals are the minimum speech units, which could reflect the characteristics of cleft palate speech disorders. In this work, an automatic initial/final segmentation method is proposed. It is an important preprocessing step in cleft palate speech signal processing. The tested cleft palate speech utterances are collected from the Cleft Palate Speech Treatment Center in the Hospital of Stomatology, Sichuan University, which has the largest cleft palate patients in China. The cleft palate speech data includes 824 speech segments, and the control samples contain 228 speech segments. The syllables are extracted from the speech utterances firstly. The proposed syllable extraction method avoids the training stage, and achieves a good performance for both voiced and unvoiced speech. Then, the syllables are classified into with “quasi-unvoiced” or with “quasi-voiced” initials. Respective initial/final segmentation methods are proposed to these two types of syllables. Moreover, a two-step segmentation method is proposed. The rough locations of syllable and initial/final boundaries are refined in the second segmentation step, in order to improve the robustness of segmentation accuracy. The experiments show that the initial/final segmentation accuracies for syllables with quasi-unvoiced initials are higher than quasi-voiced initials. For the cleft palate speech, the mean time error is 4.4ms for syllables with quasi-unvoiced initials, and 25.7ms for syllables with quasi-voiced initials, and the correct segmentation accuracy P30 for all the syllables is 91.69%. For the control samples, P30 for all the syllables is 91

  16. Automatic initial and final segmentation in cleft palate speech of Mandarin speakers.

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    Ling He

    Full Text Available The speech unit segmentation is an important pre-processing step in the analysis of cleft palate speech. In Mandarin, one syllable is composed of two parts: initial and final. In cleft palate speech, the resonance disorders occur at the finals and the voiced initials, while the articulation disorders occur at the unvoiced initials. Thus, the initials and finals are the minimum speech units, which could reflect the characteristics of cleft palate speech disorders. In this work, an automatic initial/final segmentation method is proposed. It is an important preprocessing step in cleft palate speech signal processing. The tested cleft palate speech utterances are collected from the Cleft Palate Speech Treatment Center in the Hospital of Stomatology, Sichuan University, which has the largest cleft palate patients in China. The cleft palate speech data includes 824 speech segments, and the control samples contain 228 speech segments. The syllables are extracted from the speech utterances firstly. The proposed syllable extraction method avoids the training stage, and achieves a good performance for both voiced and unvoiced speech. Then, the syllables are classified into with "quasi-unvoiced" or with "quasi-voiced" initials. Respective initial/final segmentation methods are proposed to these two types of syllables. Moreover, a two-step segmentation method is proposed. The rough locations of syllable and initial/final boundaries are refined in the second segmentation step, in order to improve the robustness of segmentation accuracy. The experiments show that the initial/final segmentation accuracies for syllables with quasi-unvoiced initials are higher than quasi-voiced initials. For the cleft palate speech, the mean time error is 4.4ms for syllables with quasi-unvoiced initials, and 25.7ms for syllables with quasi-voiced initials, and the correct segmentation accuracy P30 for all the syllables is 91.69%. For the control samples, P30 for all the

  17. Automatic initial and final segmentation in cleft palate speech of Mandarin speakers.

    Science.gov (United States)

    He, Ling; Liu, Yin; Yin, Heng; Zhang, Junpeng; Zhang, Jing; Zhang, Jiang

    2017-01-01

    The speech unit segmentation is an important pre-processing step in the analysis of cleft palate speech. In Mandarin, one syllable is composed of two parts: initial and final. In cleft palate speech, the resonance disorders occur at the finals and the voiced initials, while the articulation disorders occur at the unvoiced initials. Thus, the initials and finals are the minimum speech units, which could reflect the characteristics of cleft palate speech disorders. In this work, an automatic initial/final segmentation method is proposed. It is an important preprocessing step in cleft palate speech signal processing. The tested cleft palate speech utterances are collected from the Cleft Palate Speech Treatment Center in the Hospital of Stomatology, Sichuan University, which has the largest cleft palate patients in China. The cleft palate speech data includes 824 speech segments, and the control samples contain 228 speech segments. The syllables are extracted from the speech utterances firstly. The proposed syllable extraction method avoids the training stage, and achieves a good performance for both voiced and unvoiced speech. Then, the syllables are classified into with "quasi-unvoiced" or with "quasi-voiced" initials. Respective initial/final segmentation methods are proposed to these two types of syllables. Moreover, a two-step segmentation method is proposed. The rough locations of syllable and initial/final boundaries are refined in the second segmentation step, in order to improve the robustness of segmentation accuracy. The experiments show that the initial/final segmentation accuracies for syllables with quasi-unvoiced initials are higher than quasi-voiced initials. For the cleft palate speech, the mean time error is 4.4ms for syllables with quasi-unvoiced initials, and 25.7ms for syllables with quasi-voiced initials, and the correct segmentation accuracy P30 for all the syllables is 91.69%. For the control samples, P30 for all the syllables is 91.24%.

  18. Neutrophil to lymphocyte ratio is associated with proximal/middle segment of the LAD lesions in patients with ST segment elevation infarction

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    Ozlem Arican Ozluk

    2017-01-01

    Full Text Available Introduction: Neutrophil to lymphocyte ratio (NLR was revaled to have a close relation with atherosclerotic cardiovascular disease. The relationship between NLR and culprit plaque localization has never been studied. Aim of the study : To evaluate the association between NLR and unstable plaque localization of left anterior descending artery (LAD in anterior miyocardial infarction patients. Material and methods : Patients admitted to our hospital with acute anterior STEMI were included. Fifhy-eight patients who have single-vessel disease at LAD and their hematological parameters were analyzed retrospectively. Proximal segment of LAD lesions were groupped as Group I and mid segment of the LAD lesion groupped as Group II. The groups were compared according to their NLR and other parameters. Results : Between group I (n = 41, mean age 52.5 ±12.7 and group II (n = 17, mean ages 52.0 ±10.8; NLR, were significantly higher in group I compared to the group II (6.9 ±5.6 vs. 3.3 ±2.0, p = 0.01. In group I, left ventricular ejection fraction (LVEF was significantly lower (p = 0.02. In correlation analyzes, NLR was positively correlated with CK MB (r = 0.32, p = 0.01 and negatively correlated with LVEF (r = –0.28, p = 0.03. Conclusions : The present study demonstrated that anterior myocardial infarction patients with high NLR had a greater possibility having proximal culprit lesion on the LAD. Therefore NLR can be used as a useful tool to culprit plaque localization in patients with acute miyocardial infarction patients.

  19. Relapse after SSRO for mandibular setback movement in relation to the amount of mandibular setback and intraoperative clockwise rotation of the proximal segment.

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    Han, Jeong Joon; Yang, Hoon Joo; Lee, Shin-Jae; Hwang, Soon Jung

    2014-09-01

    The aim of this study was to evaluate the effect of the amount of setback movement and intraoperative clockwise rotation of the proximal segments on postoperative stability after orthognathic surgery to correct mandibular prognathism. Thirty-six patients with mandibular prognathism who underwent orthognathic surgery with bilateral sagittal split ramus osteotomy were evaluated. The amount of postoperative relapse was analyzed using a cephalometric analysis. Six months after surgery, the mean backward movement of the mandible at point B was 11.2 mm, the mean intraoperative clockwise rotation of the proximal segment was 4.3° and the amount of postoperative relapse at point B was 2.3 mm (20.3%) on average. The tendency of relapse did not significantly increase with the amount of setback but did increase significantly with the intraoperative clockwise rotation of the proximal segment. This study suggested that postoperative relapse after mandibular setback surgery might be more related to the degree of the intraoperative clockwise movement of the proximal segment, rather than the amount of setback movement. When the amount of mandibular setback is considerable, postoperative relapse might be minimized with adequate control of the intraoperative positioning of the proximal segments. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. [Our view on the problem of treating patients with fractures of the proximal segment of the femur].

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    Ternovoi, N K; Samokhin, A V; Grebennikov, K A

    2001-01-01

    The purpose of this study is to elucidate and analyze causes of difficulties encountered in dealing with fractures of the proximal segment of the femur and to set out our idea of solving these problems. An analysis is performed of classifications, an assessment is given of studying the adequate choice of a treatment modality, an attempt is made at formulating a doctrine of delivering qualified and specialized emergency medical service to those persons having been disabled for work, which could take account of all aspects of the injury under study. Indications for hemiarthroplasty are outlined, with the policy of primary sparing the joint elements by atraumatic osteosynthesis techniques being chosen in preference to any other policy.

  1. The results of surgical treatment of proximal long segment tracheal stenosis using bilateral hyoid bone cutting with suprahyoid release

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    khadivi E

    2009-10-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Post-intubation tracheal stenosis is a serious problem and surgical resection is the method of choice in long segment tracheal stenosis treatment. The aim of this study was to review the results of surgical treatment of long segment post intubation tracheal stenosis and the role of bilateral hyoid bone cutting in supra- hyoid release technique."n"nMethods: Between 2004 to 2008, 14 patients with proximal long segment tracheal stenosis with resection of more than 40% of trachea length were evaluated regarding surgical technique and post-operative results."n"nResults: The mean age of patients was 22.2±0.4 years. Etiology in all patients were head trauma and prolonged intubation and all patients had tracheostomy at the time of trearment. Average time between surgery and first admission was 4.5±0.5 months. Average length of stenosis and resected segment were 3.6±0.5 and 4.3±0.5cm respectively. Average increased length of trachea after bilateral hyoid bone cutting was 1.1±0.3cm. Postoperative complications occurred in one patient with wound infection, and 4 patients had stenosis recurrence which was treated in 3 patients using multiple dilation. Quality of life 2 years after surgery in 71% of patients were

  2. Recent English loanwords in Irish and the interchange of initial segments

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    Magdalena Chudak

    2010-01-01

    Full Text Available The aim of the present paper is to show that evidence from the alteration of initial segments in Irish sheds some light on a modern phenomenon whereby recent loanwords from English resist mutations. We begin the discussion with the presentation of the mechanism of word-initial mutations and show how mutations have triggered the reanalysis phenomenon of alteration of initial segments. Then the research on loanwords’ resistance to mutations conducted by Stenson (1990 and Watson (1983 is brought to light. Ultimately, we show that frequent previous alterations of a given segment could have made Irish speakers aware that mutations may lead to possible confusion of the radical consonant with other initial segments. Concluding, recent English borrowings block mutations in order to protect the quality of the initial consonant.

  3. The association of distal femur and proximal tibia shape with sex: The Osteoarthritis Initiative.

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    Wise, Barton L; Liu, Felix; Kritikos, Lisa; Lynch, John A; Parimi, Neeta; Zhang, Yuqing; Lane, Nancy E

    2016-08-01

    Risk of knee osteoarthritis (OA) is much higher in women than in men. Previous studies have shown that bone shape is a risk factor for knee OA. However, few studies have examined whether knee bone shape differs between men and women. The purpose of the present study was to determine whether there are differences between men and women in knee bone shape. We used information from the NIH-funded Osteoarthritis Initiative (OAI), a cohort of persons aged 45-79 at baseline who either had symptomatic knee OA or were at high risk of it. Among participants aged between 45 and 60 years, we randomly sampled 340 knees without radiographic OA (i.e., Kellgren/Lawrence grade of 0 in central readings on baseline radiograph). We characterized distal femur and proximal tibia shape of these selected radiographs using statistical shape modeling (SSM). We performed linear regression analysis to examine the association between sex and each knee shape mode (proximal tibia and distal femur), adjusting for age, race, body mass index (BMI), and clinic site. The mean age was 52.7 years (±4.3 SD) for both men and women. There were 192 female and 147 male knees for the distal femur analysis. Thirteen modes were derived for femoral shape, accounting for 95.5% of the total variance. Distal femur mode 1 had the greatest difference in standardized score of knee shape between females and males (1.04, p femur and proximal tibia that form the knee joint differ by sex. Additional analyses are warranted to assess whether the difference in risk of OA between the sexes arises from bone shape differences. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. A period of structural plasticity at the axon initial segment in developing visual cortex

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    Annika eGutzmann

    2014-03-01

    Full Text Available Cortical networks are shaped by sensory experience and are most susceptible to modifications during critical periods characterized by enhanced plasticity at the structural and functional level. A system particularly well-studied in this context is the mammalian visual system. Plasticity has been documented for the somatodendritic compartment of neurons in detail. A neuronal microdomain not yet studied in this context is the axon initial segment (AIS located at the proximal axon segment. It is a specific electrogenic axonal domain and the site of action potential generation. Recent studies showed that structure and function of the AIS can be dynamically regulated. Here we hypothesize that the AIS shows a dynamic regulation during maturation of the visual cortex. We therefore analyzed AIS length development from embryonic day (E 12.5 to adulthood in mice. A tri-phasic time course of AIS length remodeling during development was observed. AIS first appeared at E14.5 and increased in length throughout the postnatal period to a peak between postnatal day (P 10 to P15 (eyes open P13-14. Then, AIS length was reduced significantly around the beginning of the critical period for ocular dominance plasticity (CP, P21. Shortest AIS were observed at the peak of the CP (P28, followed by a moderate elongation towards the end of the CP (P35. To test if the dynamic maturation of the AIS is influenced by eye opening (onset of activity, animals were deprived of visual input before and during the CP. Deprivation for 1 week prior to eye opening did not affect AIS length development. However, deprivation from P0-P28 and P14-P28 resulted in AIS length distribution similar to the peak at P15. In other words, deprivation from birth prevents the transient shortening of the AIS and maintains an immature AIS length. These results are the first to suggest a dynamic maturation of the AIS in cortical neurons and point to novel mechanisms in the development of neuronal

  5. Synchrony dynamics during initiation, failure, and rescue of the segmentation clock.

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    Riedel-Kruse, Ingmar H; Müller, Claudia; Oates, Andrew C

    2007-09-28

    The "segmentation clock" is thought to coordinate sequential segmentation of the body axis in vertebrate embryos. This clock comprises a multicellular genetic network of synchronized oscillators, coupled by intercellular Delta-Notch signaling. How this synchrony is established and how its loss determines the position of segmentation defects in Delta and Notch mutants are unknown. We analyzed the clock's synchrony dynamics by varying strength and timing of Notch coupling in zebra-fish embryos with techniques for quantitative perturbation of gene function. We developed a physical theory based on coupled phase oscillators explaining the observed onset and rescue of segmentation defects, the clock's robustness against developmental noise, and a critical point beyond which synchrony decays. We conclude that synchrony among these genetic oscillators can be established by simultaneous initiation and self-organization and that the segmentation defect position is determined by the difference between coupling strength and noise.

  6. Action potential generation requires a high sodium channel density in the axon initial segment

    NARCIS (Netherlands)

    Kole, Maarten H. P.; Ilschner, Susanne U.; Kampa, Björn M.; Williams, Stephen R.; Ruben, Peter C.; Stuart, Greg J.

    2008-01-01

    The axon initial segment ( AIS) is a specialized region in neurons where action potentials are initiated. It is commonly assumed that this process requires a high density of voltage-gated sodium ( Na(+)) channels. Paradoxically, the results of patch-clamp studies suggest that the Na(+) channel

  7. Allosteric coupling between proximal C-terminus and selectivity filter is facilitated by the movement of transmembrane segment 4 in TREK-2 channel.

    Science.gov (United States)

    Zhuo, Ren-Gong; Peng, Peng; Liu, Xiao-Yan; Yan, Hai-Tao; Xu, Jiang-Ping; Zheng, Jian-Quan; Wei, Xiao-Li; Ma, Xiao-Yun

    2016-02-16

    TREK-2, a member of two-pore-domain potassium channel family, regulates cellular excitability in response to diverse stimuli. However, how such stimuli control channel function remains unclear. Here, by characterizing the responses of cytosolic proximal C-terminus deletant (ΔpCt) and transmembrane segment 4 (M4)-glycine hinge mutant (G312A) to 2-Aminoethoxydiphenyl borate (2-APB), an activator of TREK-2, we show that the transduction initiated from pCt domain is allosterically coupled with the conformation of selectivity filter (SF) via the movements of M4, without depending on the original status of SF. Moreover, ΔpCt and G312A also exhibited blunted responses to extracellular alkalization, a model to induce SF conformational transition. These results suggest that the coupling between pCt domain and SF is bidirectional, and M4 movements are involved in both processes. Further mechanistic exploration reveals that the function of Phe316, a residue close to the C-terminus of M4, is associated with such communications. However, unlike TREK-2, M4-hinge of TREK-1 only controls the transmission from pCt to SF, rather than SF conformational changes triggered by pHo changes. Together, our findings uncover the unique gating properties of TREK-2, and elucidate the mechanisms for how the extracellular and intracellular stimuli harness the pore gating allosterically.

  8. Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation

    DEFF Research Database (Denmark)

    Cotel, Florence; Exley, Richard; Cragg, Stephanie

    2013-01-01

    --as during motor exercise--activated 5-HT1A receptors that decreased motoneuronal excitability. Electrophysiological tests combined with pharmacology showed that focal activation of 5-HT1A receptors at the axon initial segment (AIS), but not on other motoneuronal compartments, inhibited the action potential...

  9. MECS-VINE®: A New Proximal Sensor for Segmented Mapping of Vigor and Yield Parameters on Vineyard Rows

    Directory of Open Access Journals (Sweden)

    Matteo Gatti

    2016-11-01

    Full Text Available Ground-based proximal sensing of vineyard features is gaining interest due to its ability to serve in even quite small plots with the advantage of being conducted concurrently with normal vineyard practices (i.e., spraying, pruning or soil tilling with no dependence upon weather conditions, external services or law-imposed limitations. The purpose of the present work was to test performance of the new terrestrial multi-sensor MECS-VINE® in terms of reliability and degree of correlation with several canopy growth and yield parameters in the grapevine. MECS-VINE®, once conveniently positioned in front of the tractor, can provide simultaneous assessment of growth features and microclimate of specific canopy sections of the two adjacent row sides. MECS-VINE® integrates a series of microclimate sensors (air relative humidity, air and surface temperature with two (left and right matrix-based optical RGB imaging sensors and a related algorithm, termed Canoyct. MECS-VINE® was run five times along the season in a mature cv. Barbera vineyard and a Canopy Index (CI, pure number varying from 0 to 1000, calculated through its built-in algorithm, validated vs. canopy structure parameters (i.e., leaf layer number, fractions of canopy gaps and interior leaves derived from point quadrat analysis. Results showed that CI was highly correlated vs. any canopy parameter at any date, although the closest relationships were found for CI vs. fraction of canopy gaps (R2 = 0.97 and leaf layer number (R2 = 0.97 for data pooled over 24 test vines. While correlations against canopy light interception and total lateral leaf area were still unsatisfactory, a good correlation was found vs. cluster and berry weight (R2 = 0.76 and 0.71, respectively suggesting a good potential also for yield estimates. Besides the quite satisfactory calibration provided, main improvements of MECS-VINE® usage versus other current equipment are: (i MECS-VINE® delivers a segmented evaluation

  10. MECS-VINE®: A New Proximal Sensor for Segmented Mapping of Vigor and Yield Parameters on Vineyard Rows.

    Science.gov (United States)

    Gatti, Matteo; Dosso, Paolo; Maurino, Marco; Merli, Maria Clara; Bernizzoni, Fabio; José Pirez, Facundo; Platè, Bonfiglio; Bertuzzi, Gian Carlo; Poni, Stefano

    2016-11-27

    Ground-based proximal sensing of vineyard features is gaining interest due to its ability to serve in even quite small plots with the advantage of being conducted concurrently with normal vineyard practices (i.e., spraying, pruning or soil tilling) with no dependence upon weather conditions, external services or law-imposed limitations. The purpose of the present work was to test performance of the new terrestrial multi-sensor MECS-VINE® in terms of reliability and degree of correlation with several canopy growth and yield parameters in the grapevine. MECS-VINE®, once conveniently positioned in front of the tractor, can provide simultaneous assessment of growth features and microclimate of specific canopy sections of the two adjacent row sides. MECS-VINE® integrates a series of microclimate sensors (air relative humidity, air and surface temperature) with two (left and right) matrix-based optical RGB imaging sensors and a related algorithm, termed Canoyct). MECS-VINE® was run five times along the season in a mature cv. Barbera vineyard and a Canopy Index (CI, pure number varying from 0 to 1000), calculated through its built-in algorithm, validated vs. canopy structure parameters (i.e., leaf layer number, fractions of canopy gaps and interior leaves) derived from point quadrat analysis. Results showed that CI was highly correlated vs. any canopy parameter at any date, although the closest relationships were found for CI vs. fraction of canopy gaps (R² = 0.97) and leaf layer number (R² = 0.97) for data pooled over 24 test vines. While correlations against canopy light interception and total lateral leaf area were still unsatisfactory, a good correlation was found vs. cluster and berry weight (R² = 0.76 and 0.71, respectively) suggesting a good potential also for yield estimates. Besides the quite satisfactory calibration provided, main improvements of MECS-VINE® usage versus other current equipment are: (i) MECS-VINE® delivers a segmented evaluation of the

  11. Percutaneous Stent Implantation for Treating Multivessel Coronary Disease in Patients with and without Involvement of the Proximal Segment of the Anterior Descending Coronary Artery

    Directory of Open Access Journals (Sweden)

    Salgueiro Sandro

    2002-01-01

    Full Text Available OBJECTIVE: To assess coronary stent placement in patients with multivessel coronary disease and involvement of the proximal portion of the anterior descending coronary artery. METHODS: We retrospectively analyzed the in-hospital and late evolution of 189 patients with multivessel coronary disease, who underwent percutaneous coronary stent placement. These patients were divided into 2 groups as follows: group I (GI - 59 patients with involvement of the proximal segment of the anterior descending coronary artery; and group II (GII - 130 patients without involvement of the proximal segment of the anterior descending coronary artery. RESULTS: No significant difference was observed in the success rate of the procedure (91.5% versus 97.6%, p=0.86, nor in the occurrence of major adverse cardiac events (5.1% versus 1.5%, p=0.38, nor in the occurrence of major vascular complications (1.7% versus 0%, p=0.69 in the in-hospital phase. In the late follow-up, the incidence of major adverse cardiac events (15.4% versus 13.7%, p=0.73 and the need for new revascularization (13.5% versus 10.3%, p=0.71 were similar for both groups. CONCLUSION: The in-hospital and late evolution of patients with multivessel coronary disease with and without involvement of the proximal segment of the anterior descending coronary artery treated with coronary stent placement did not differ. This suggests that this revascularization method is an effective procedure and a valuable option for treating these types of patients.

  12. Automatic initialization and quality control of large-scale cardiac MRI segmentations.

    Science.gov (United States)

    Albà, Xènia; Lekadir, Karim; Pereañez, Marco; Medrano-Gracia, Pau; Young, Alistair A; Frangi, Alejandro F

    2017-10-16

    Continuous advances in imaging technologies enable ever more comprehensive phenotyping of human anatomy and physiology. Concomitant reduction of imaging costs has resulted in widespread use of imaging in large clinical trials and population imaging studies. Magnetic Resonance Imaging (MRI), in particular, offers one-stop-shop multidimensional biomarkers of cardiovascular physiology and pathology. A wide range of analysis methods offer sophisticated cardiac image assessment and quantification for clinical and research studies. However, most methods have only been evaluated on relatively small databases often not accessible for open and fair benchmarking. Consequently, published performance indices are not directly comparable across studies and their translation and scalability to large clinical trials or population imaging cohorts is uncertain. Most existing techniques still rely on considerable manual intervention for the initialization and quality control of the segmentation process, becoming prohibitive when dealing with thousands of images. The contributions of this paper are three-fold. First, we propose a fully automatic method for initializing cardiac MRI segmentation, by using image features and random forests regression to predict an initial position of the heart and key anatomical landmarks in an MRI volume. In processing a full imaging database, the technique predicts the optimal corrective displacements and positions in relation to the initial rough intersections of the long and short axis images. Second, we introduce for the first time a quality control measure capable of identifying incorrect cardiac segmentations with no visual assessment. The method uses statistical, pattern and fractal descriptors in a random forest classifier to detect failures to be corrected or removed from subsequent statistical analysis. Finally, we validate these new techniques within a full pipeline for cardiac segmentation applicable to large-scale cardiac MRI databases. The

  13. Radiographic detection of initial carious lesions on the proximal surfaces of teeth. Part I. The influence of exposure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, L.V.

    1987-08-01

    The relationship between a number of technical exposure conditions and the diagnostic value of bitewing radiographs in the interpretation of initial proximal carious lesions was evaluated. The most important exposure factors for radiographs are tube voltage, filtration, and exposure time. Tube voltage and filtration were found to have an insignificant influence on the diagnostic quality. Exposure time proved to be the most critical factor in influencing diagnostic quality. The greatest difference in diagnostic quality, however, was caused by differences between observers.

  14. Conditional-mean initialization using neighboring objects in deformable model segmentation

    Science.gov (United States)

    Jeong, Ja-Yeon; Stough, Joshua V.; Marron, J. Steve; Pizer, Stephen M.

    2008-03-01

    Most model-based segmentation methods find a target object in a new image by constructing an objective function and optimizing it using a standard minimization algorithm. In general, the objective function has two penalty terms: 1) for deforming a template model and 2) for mismatch between the trained image intensities relative to the template model and the observed image intensities relative to the deformed template model in the target image. While it is difficult to establish an objective function with a global minimum at the desired segmentation result, even such an objective function is typically non-convex due to the complexity of the intensity patterns and the many structures surrounding the target object. Thus, it is critical that the optimization starts at a point close to the global minimum of the objective function in deformable model-based segmentation framework. For a segmentation method in maximum a posteriori framework a good objective function can be obtained by learning the probability distributions of the population shape deformations and their associated image intensities because each penalty term can be simplified to a squared function of some distance metric defined in the shape space. The mean shape and intensities of the learned probability distributions also provide a good initialization for segmentation. However, a major concern in estimating the shape prior is the stability of the estimated shape distributions from given training samples because the feature space of a shape model is usually very high dimensional while the number of training samples is limited. A lot of effort in that regard have been made to attain a stable estimation of shape probability distribution. In this paper, we describe our approach to stably estimate a shape probability distribution when good segmentations of objects adjacent to the target object are available. Our approach is to use a conditional shape probability distribution (CSPD) to take into account in the

  15. Augmenting atlas-based liver segmentation for radiotherapy treatment planning by incorporating image features proximal to the atlas contours

    Science.gov (United States)

    Li, Dengwang; Liu, Li; Chen, Jinhu; Li, Hongsheng; Yin, Yong; Ibragimov, Bulat; Xing, Lei

    2017-01-01

    Atlas-based segmentation utilizes a library of previously delineated contours of similar cases to facilitate automatic segmentation. The problem, however, remains challenging because of limited information carried by the contours in the library. In this studying, we developed a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. This study presented a new concept of atlas based segmentation method. Instead of using the complete volume of the target organs, only information along the organ contours from the atlas images was used for guiding segmentation of the new image. In setting up an atlas-based library, we included not only the coordinates of contour points, but also the image features adjacent to the contour. In this work, 139 CT images with normal appearing livers collected for radiotherapy treatment planning were used to construct the library. The CT images within the library were first registered to each other using affine registration. The nonlinear narrow shell was generated alongside the object contours of registered images. Matching voxels were selected inside common narrow shell image features of a library case and a new case using a speed-up robust features (SURF) strategy. A deformable registration was then performed using a thin plate splines (TPS) technique. The contour associated with the library case was propagated automatically onto the new image by exploiting the deformation field vectors. The liver contour was finally obtained by employing level set based energy optimization within the narrow shell. The performance of the proposed method was evaluated by comparing quantitatively the auto-segmentation results with that delineated by physicians. A novel atlas-based segmentation technique with inclusion of neighborhood image features through the introduction of a narrow-shell surrounding the target objects was established. Application of the technique to

  16. Augmenting atlas-based liver segmentation for radiotherapy treatment planning by incorporating image features proximal to the atlas contours.

    Science.gov (United States)

    Li, Dengwang; Liu, Li; Chen, Jinhu; Li, Hongsheng; Yin, Yong; Ibragimov, Bulat; Xing, Lei

    2017-01-07

    Atlas-based segmentation utilizes a library of previously delineated contours of similar cases to facilitate automatic segmentation. The problem, however, remains challenging because of limited information carried by the contours in the library. In this studying, we developed a narrow-shell strategy to enhance the information of each contour in the library and to improve the accuracy of the exiting atlas-based approach. This study presented a new concept of atlas based segmentation method. Instead of using the complete volume of the target organs, only information along the organ contours from the atlas images was used for guiding segmentation of the new image. In setting up an atlas-based library, we included not only the coordinates of contour points, but also the image features adjacent to the contour. In this work, 139 CT images with normal appearing livers collected for radiotherapy treatment planning were used to construct the library. The CT images within the library were first registered to each other using affine registration. The nonlinear narrow shell was generated alongside the object contours of registered images. Matching voxels were selected inside common narrow shell image features of a library case and a new case using a speed-up robust features (SURF) strategy. A deformable registration was then performed using a thin plate splines (TPS) technique. The contour associated with the library case was propagated automatically onto the new image by exploiting the deformation field vectors. The liver contour was finally obtained by employing level set based energy optimization within the narrow shell. The performance of the proposed method was evaluated by comparing quantitatively the auto-segmentation results with that delineated by physicians. A novel atlas-based segmentation technique with inclusion of neighborhood image features through the introduction of a narrow-shell surrounding the target objects was established. Application of the technique to

  17. Level Set Based Hippocampus Segmentation in MR Images with Improved Initialization Using Region Growing

    Directory of Open Access Journals (Sweden)

    Xiaoliang Jiang

    2017-01-01

    Full Text Available The hippocampus has been known as one of the most important structures referred to as Alzheimer’s disease and other neurological disorders. However, segmentation of the hippocampus from MR images is still a challenging task due to its small size, complex shape, low contrast, and discontinuous boundaries. For the accurate and efficient detection of the hippocampus, a new image segmentation method based on adaptive region growing and level set algorithm is proposed. Firstly, adaptive region growing and morphological operations are performed in the target regions and its output is used for the initial contour of level set evolution method. Then, an improved edge-based level set method utilizing global Gaussian distributions with different means and variances is developed to implement the accurate segmentation. Finally, gradient descent method is adopted to get the minimization of the energy equation. As proved by experiment results, the proposed method can ideally extract the contours of the hippocampus that are very close to manual segmentation drawn by specialists.

  18. Assessment and comparison of proximal segment changes following mandibular set-back through bilateral sagittal split ramus osteotomy and intraoral verticosagittal ramus osteotomy

    Directory of Open Access Journals (Sweden)

    Mahmood Hashemi H.

    2008-04-01

    Full Text Available Background and Aim: Proximal segment movements following different methods of ramus osteotomy is one of the undesired consequences of orthognathic surgery. Theoretically, it seems that intraoral verticosagittal ramus osteotomy can minimize the movement of proximal segment. In this study, changes in intergonial distance and ramus flaring angles were evaluated and compared in transverse plane after mandibular set back by two osteotomy techniques.Materials and Methods: In this randomized clinical trial 20 patients with mandibular prognathism without any asymmetry were selected and divided into two groups of 10 each.One group was treated by bilateral sagittal split ramus osteotomy and the other by intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner ramal angle in transverse plane were measured on radiographs before and 1 and 12 weeks post surgery . Data were analyzed using covariance test with P<0.05 as the level of significance.Results: Changes of intergonial distance and interramal angle in each group were significant after 1 and 12 weeks after surgery. No statistically significant difference was observed between the two studied groups.Conclusion: According to the results of this study, there is no difference between bilateral sagittal split and intraoral verticosagittal ramus osteotomy techniques regarding mandibular width and ramus flaring changes.

  19. [Association of myocardial bridge of the left anterior descending coronary artery with coronary atherosclerotic stenosis in the segment proximal to the site of bridge].

    Science.gov (United States)

    Tian, Shu-ping; Li, Chun-ping; Song, Xiang; Gan, Lu; Wu, Fang; Chen, Min; Xiao, Hua-feng; Yang, Li

    2014-04-01

    To investigate whether myocardial bridging (MB) is independently associated with coronary atherosclerosis proximal to MB in the left anterior descending coronary artery (LAD) identified by computed tomographic coronary angiography (CCTA). From March 2011 to December 2012, patients (n=9 862) with suspected coronary disease underwent CCTA using dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack, and body mass index) and the results of CCTA were reviewed. Two radiologists evaluated the coronary artery for MB and coronary atherosclerosis stenosis (CAS) in LAD and made a diagnosis by consensus. Significant independent risk factors for CAS were investigated by multivariate logistic regression analysis. A total of 3 182 (32.3%) cases of MB and 3 359 cases of CAS of LAD were identified. No patient with CAS in the tunneled segment was found. The mean length of bridges and the mean thickness of the overlying myocardium was (17.3±5.2) mm and (1.2±0.9) mm, respectively. There were 1658 MB cases in 3 359 cases of LAD stenosis and 1 524 MB cases in 6 503 cases of no LAD stenosis (χ(2)=681.12, Pheart attack, smoking, hypertension, dyslipidemia, diabetes mellitus, and resting heart rate (OR=2.86, 95% CI=2.60-3.16, P < 0.001). MB in the LAD is independently associated with CAS in the proximal segment to MB.

  20. Proximity of transmembrane segments 5 and 8 of the glutamate transporter GLT-1 inferred from paired cysteine mutagenesis.

    Directory of Open Access Journals (Sweden)

    Xiuping Zhang

    Full Text Available BACKGROUND: GLT-1 is a glial glutamate transporter which maintains low synaptic concentrations of the excitatory neurotransmitter enabling efficient synaptic transmission. Based on the crystal structure of the bacterial homologue Glt(Ph, it has been proposed that the reentrant loop HP2, which connects transmembrane domains (TM 7 and 8, moves to open and close access to the binding pocket from the extracellular medium. However the conformation change between TM5 and TM8 during the transport cycle is not clear yet. We used paired cysteine mutagenesis in conjunction with treatments with Copper(II(1,10-Phenanthroline(3 (CuPh, to verify the predicted proximity of residues located at these structural elements of GLT-1. METHODOLOGY/PRINCIPAL FINDINGS: To assess the proximity of transmembrane domain (TM 5 relative to TM8 during transport by the glial glutamate transporter GLT-1/EAAT2, cysteine pairs were introduced at the extracellular ends of these structural elements. A complete inhibition of transport by Copper(II(1,10-Phenanthroline(3 is observed in the double mutants I295C/I463C and G297C/I463C, but not in the corresponding single mutants. Glutamate and potassium, both expected to increase the proportion of inward-facing transporters, significantly protected against the inhibition of transport activity of I295C/I463C and G297C/I463C by CuPh. Transport by the double mutants I295C/I463C and G297C/I463C also was inhibited by Cd(2+. CONCLUSIONS/SIGNIFICANCE: Our results suggest that TM5 (Ile-295, Gly-297 is in close proximity to TM8 (Ile-463 in the mammalian transporter, and that the spatial relationship between these domains is altered during the transport cycle.

  1. A shape-guided deformable model with evolutionary algorithm initialization for 3D soft tissue segmentation.

    Science.gov (United States)

    Heimann, Tobias; Münzing, Sascha; Meinzer, Hans-Peter; Wolf, Ivo

    2007-01-01

    We present a novel method for the segmentation of volumetric images, which is especially suitable for highly variable soft tissue structures. Core of the algorithm is a statistical shape model (SSM) of the structure of interest. A global search with an evolutionary algorithm is employed to detect suitable initial parameters for the model, which are subsequently optimized by a local search similar to the Active Shape mechanism. After that, a deformable mesh with the same topology as the SSM is used for the final segmentation: While external forces strive to maximize the posterior probability of the mesh given the local appearance around the boundary, internal forces governed by tension and rigidity terms keep the shape similar to the underlying SSM. To prevent outliers and increase robustness, we determine the applied external forces by an algorithm for optimal surface detection with smoothness constraints. The approach is evaluated on 54 CT images of the liver and reaches an average surface distance of 1.6 +/- 0.5 mm in comparison to manual reference segmentations.

  2. Biomechanical Analysis of the Proximal Adjacent Segment after Multilevel Instrumentation of the Thoracic Spine: Do Hooks Ease the Transition?

    Science.gov (United States)

    Metzger, Melodie F.; Robinson, Samuel T.; Svet, Mark T.; Liu, John C.; Acosta, Frank L.

    2015-01-01

    Study Design Biomechanical cadaveric study. Objective Clinical studies indicate that using less-rigid fixation techniques in place of the standard all-pedicle screw construct when correcting for scoliosis may reduce the incidence of proximal junctional kyphosis and improve patient outcomes. The purpose of this study is to investigate whether there is a biomechanical advantage to using supralaminar hooks in place of pedicle screws at the upper-instrumented vertebrae in a multilevel thoracic construct. Methods T7–T12 spines were biomechanically tested: (1) intact; (2) following a two-level pedicles screw fusion from T9 to T11; and after proximal extension of the fusion to T8–T9 with (3) bilateral supra-laminar hooks, (4) a unilateral hook + unilateral screw hybrid, or (5) bilateral pedicle screws. Specimens were nondestructively loaded while three-dimensional kinematics and intradiscal pressure at the supra-adjacent level were recorded. Results Supra-adjacent hypermobility was reduced when bilateral hooks were used in place of pedicle screws at the upper-instrumented level, with statistically significant differences in lateral bending and torsion (p spine and the flexible native spine and is the first to demonstrate these results with laminar hooks. PMID:27190735

  3. Axonal Membranes and Their Domains: Assembly and Function of the Axon Initial Segment and Node of Ranvier

    Directory of Open Access Journals (Sweden)

    Andrew D. Nelson

    2017-05-01

    Full Text Available Neurons are highly specialized cells of the nervous system that receive, process and transmit electrical signals critical for normal brain function. Here, we review the intricate organization of axonal membrane domains that facilitate rapid action potential conduction underlying communication between complex neuronal circuits. Two critical excitable domains of vertebrate axons are the axon initial segment (AIS and the nodes of Ranvier, which are characterized by the high concentrations of voltage-gated ion channels, cell adhesion molecules and specialized cytoskeletal networks. The AIS is located at the proximal region of the axon and serves as the site of action potential initiation, while nodes of Ranvier, gaps between adjacent myelin sheaths, allow rapid propagation of the action potential through saltatory conduction. The AIS and nodes of Ranvier are assembled by ankyrins, spectrins and their associated binding partners through the clustering of membrane proteins and connection to the underlying cytoskeleton network. Although the AIS and nodes of Ranvier share similar protein composition, their mechanisms of assembly are strikingly different. Here we will cover the mechanisms of formation and maintenance of these axonal excitable membrane domains, specifically highlighting the similarities and differences between them. We will also discuss recent advances in super resolution fluorescence imaging which have elucidated the arrangement of the submembranous axonal cytoskeleton revealing a surprising structural organization necessary to maintain axonal organization and function. Finally, human mutations in axonal domain components have been associated with a growing number of neurological disorders including severe cognitive dysfunction, epilepsy, autism, neurodegenerative diseases and psychiatric disorders. Overall, this review highlights the assembly, maintenance and function of axonal excitable domains, particularly the AIS and nodes of

  4. Requirement of subunit co-assembly and ankyrin-G for M-channel localization at the axon initial segment

    DEFF Research Database (Denmark)

    Rasmussen, Hanne B; Frøkjaer-Jensen, Christian; Jensen, Camilla Stampe

    2007-01-01

    controversial. We report here that KCNQ2 and KCNQ3 subunits are localized to the axon initial segment of pyramidal neurons of adult rat hippocampus and in cultured hippocampal neurons. We demonstrate that the localization of the KCNQ2/3 channel complex to the axon initial segment is favored by co......-expression of the two channel subunits. Deletion of the ankyrin-G-binding motif in both the KCNQ2 and KCNQ3 C-terminals leads to the disappearance of the complex from the axon initial segment, albeit the channel complex remains functional and still reaches the plasma membrane. We further show that although heteromeric...... assembly of the channel complex favours localization to the axon initial segment, deletion of the ankyrin-G-binding motif in KCNQ2 alone does not alter the subcellular localization of KCNQ2/3 heteromers. By contrast, deletion of the ankyrin-G-binding motif in KCNQ3 significantly reduces AIS enrichment...

  5. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    Directory of Open Access Journals (Sweden)

    Anders Victor ePetersen

    2015-10-01

    Full Text Available The axon initial segment (AIS is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recoding of extracellular local field potentials and whole-cell patch-clamp recording of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from the brain.

  6. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording.

    Science.gov (United States)

    Petersen, Anders V; Johansen, Emil Ø; Perrier, Jean-François

    2015-01-01

    The axon initial segment (AIS) is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recording of extracellular local field potentials and whole-cell patch-clamp recording of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from the brain.

  7. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    DEFF Research Database (Denmark)

    Petersen, Anders V.; Johansen, Emil O.; Perrier, Jean-Francois

    2015-01-01

    in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recording of extracellular local field potentials and whole-cell patch-clamp recording......The axon initial segment (AIS) is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS...... of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from...

  8. A pilot study for segmentation of pharyngeal and sino-nasal airway subregions by automatic contour initialization.

    Science.gov (United States)

    Neelapu, Bala Chakravarthy; Kharbanda, Om Prakash; Sardana, Viren; Gupta, Abhishek; Vasamsetti, Srikanth; Balachandran, Rajiv; Rana, Shailendra Singh; Sardana, Harish Kumar

    2017-11-01

    The objective of the present study is to put forward a novel automatic segmentation algorithm to segment pharyngeal and sino-nasal airway subregions on 3D CBCT imaging datasets. A fully automatic segmentation of sino-nasal and pharyngeal airway subregions was implemented in MATLAB programing environment. The novelty of the algorithm is automatic initialization of contours in upper airway subregions. The algorithm is based on boundary definitions of the human anatomy along with shape constraints with an automatic initialization of contours to develop a complete algorithm which has a potential to enhance utility at clinical level. Post-initialization; five segmentation techniques: Chan-Vese level set (CVL), localized Chan-Vese level set (LCVL), Bhattacharya distance level set (BDL), Grow Cut (GC), and Sparse Field method (SFM) were used to test the robustness of automatic initialization. Precision and F-score were found to be greater than 80% for all the regions with all five segmentation methods. High precision and low recall were observed with BDL and GC techniques indicating an under segmentation. Low precision and high recall values were observed with CVL and SFM methods indicating an over segmentation. A Larger F-score value was observed with SFM method for all the subregions. Minimum F-score value was observed for naso-ethmoidal and sphenoidal air sinus region, whereas a maximum F-score was observed in maxillary air sinuses region. The contour initialization was more accurate for maxillary air sinuses region in comparison with sphenoidal and naso-ethmoid regions. The overall F-score was found to be greater than 80% for all the airway subregions using five segmentation techniques, indicating accurate contour initialization. Robustness of the algorithm needs to be further tested on severely deformed cases and on cases with different races and ethnicity for it to have global acceptance in Katradental radKatraiology workflow.

  9. Organization of proximal signal initiation at the TCR:CD3 complex.

    Science.gov (United States)

    Guy, Clifford S; Vignali, Dario A A

    2009-11-01

    The series of events leading to T-cell activation following antigen recognition has been extensively investigated. Although the exact mechanisms of ligand binding and transmission of this extracellular interaction into a productive intracellular signaling sequence remains incomplete, it has been known for many years that the immunoreceptor tyrosine activation motifs (ITAMs) of the T-cell receptor (TCR):CD3 complex are required for initiation of this signaling cascade because of the recruitment and activation of multiple protein tyrosine kinases, signaling intermediates, and adapter molecules. It however remains unclear why the TCR:CD3 complex requires 10 ITAMs, while many other ITAM-containing immune receptors, such as Fc receptors (FcRs) and the B cell receptor (BCR), contain far fewer ITAMs. We have recently demonstrated that various parameters of T cell development and activation are influenced by the number, as well as location and type, of ITAMs within the TCR:CD3 complex and hence propose that the TCR is capable of 'scalable signaling' that facilitates the initiation and orchestration of diverse T-cell functions. While many of the underlying mechanisms remain hypothetical, this review intends to amalgamate what we have learned from conventional biochemical analyses regarding initiation and diversification of T-cell signaling, with more recent evidence from molecular and fluorescent microscopic analyses, to propose a broader purpose for the TCR:CD3 ITAMs. Rather than simply signal initiation, individual ITAMs may also be responsible for the differential recruitment of signaling and regulatory molecules which ultimately affects T-cell development, activation and differentiation.

  10. Uptake of (/sup 3/H)PAH and (/sup 14/C)urate into isolated proximal tubular segments of the pig kidney

    Energy Technology Data Exchange (ETDEWEB)

    Schali, C.; Roch-Ramel, F.

    1991-12-01

    Segments of proximal convoluted (PCT) and proximal straight (PST) tubules of minipigs and normal-sized pigs were microdissected (without collagenase treatment) and incubated (30 min, 37/sup 0/C, pH 7.4) in Ringer solution (under O/sub 2/) containing (/sup 3/H)PAH (3.10/sup -5/ M) or (/sup 14/C)urate (9.10/sup -5/ M) and, in inhibitor studies, probenecid, pyrazinoic acid (PZA), urate, or PAH, all at 1 mM. In both strains the uptake of (/sup 3/H)PAH expressed as mean T/M ratio (cpm per ml tissue water/cpm per ml incubation medium) was significantly higher (P<0.001) in PCT than in PST. T/M was 34.7 +/- 5.6 (SE) in 34 PCT and 2.4 +/- 0.3 in 24 PST of eight minipigs. In two normal-sized pigs the T/M was 14.1 +/- 3.6 in 15 PCT and 1.5 +/- 0.1 in six PST. Similar results were obtained for (/sup 14/C)urate. In eight minipigs the T/M was 4.9 +/- 0.5 in 24 PCT and 2 +/- 0.2 in 25 PST. In normal-sized pigs the T/M was 3.8 +/- 0.3 in 35 PCT (five pigs) and 1.9 +/- 0.4 in eight PST (two pigs). In inhibitor studies urate significantly depressed the uptake of (/sup 3/H)PAH, and unlabeled PAH depressed the uptake of (/sup 14/C)urate. PZA significantly inhibited the uptake of (/sup 14/C)urate but not that of (/sup 3/H)PAH, whereas probenecid had a strong inhibitory efect on the uptake of both compounds. These results suggest that (/sup 14/C)urate and (/sup 3/H)PAH are transported by a transport system located mainly in the proximal convoluted tubule. These findings are in contrast in the findings are in contrast to the findings obtained in rabbits in which the transport system of PAH and urate is mainly located in the proximal part of the pars recta.

  11. Low Osteoporosis Treatment Initiation Rate in Women after Distal Forearm or Proximal Humerus Fracture: A Healthcare Database Nested Cohort Study.

    Directory of Open Access Journals (Sweden)

    Marie Viprey

    Full Text Available Treatment initiation rates following fragility fractures have often been reported to be low and in recent years numerous programs have been implemented worldwide to increase them. This study aimed at describing osteoporosis (OP treatment initiation in a representative sample of women who were hospitalized for a distal forearm fracture (DFF or proximal humerus fracture (PHF in 2009-2011 in France. The data source was a nationwide sample of 600,000 individuals, extracted from the French National Insurance Healthcare System database. All women aged 50 years and older who were hospitalized for a DFF or PHF between 2009 and 2011 and who had not received any OP treatment in the preceding 12 months were included in a retrospective cohort study. OP treatments initiated during the year following the fracture were analyzed. From 2009 to 2011, 729 women were hospitalized for a DFF or a PHF and 284 were on OP treatment at the time of the fracture occurrence. Among the 445 women who had no prevalent OP treatment, 131 (29.4% received supplementation treatment only (vitamin D and/or calcium and 42 (9.4% received a pharmacologic OP treatment in the year following their fracture. Pharmacological OP treatments included bisphosphonates (n = 21, strontium ranelate (n = 14, hormone replacement therapy (n = 4, or raloxifene (n = 3. General practitioners prescribed 75% of initial OP treatments. Despite the guidelines published in 2006 and the numerous initiatives to promote post-fracture OP treatment, OP treatment initiation rate in women who were hospitalized for a fragility fracture remained low in 2009-2011 in France.

  12. Synchrony Dynamics During Initiation, Failure, and Rescue of the Segmentation Clock

    OpenAIRE

    Riedel-Kruse, Ingmar H.; Müller, Claudia; Andrew C. Oates

    2007-01-01

    The “segmentation clock” is thought to coordinate sequential segmentation of the body axis in vertebrate embryos. This clock comprises a multicellular genetic network of synchronized oscillators, coupled by intercellular Delta-Notch signaling. How this synchrony is established and how its loss determines the position of segmentation defects in Delta and Notch mutants are unknown. We analyzed the clock's synchrony dynamics by varying strength and timing of Notch coupling in zebra-fish embryos ...

  13. Covariation of axon initial segment location and dendritic tree normalizes the somatic action potential.

    Science.gov (United States)

    Hamada, Mustafa S; Goethals, Sarah; de Vries, Sharon I; Brette, Romain; Kole, Maarten H P

    2016-12-20

    In mammalian neurons, the axon initial segment (AIS) electrically connects the somatodendritic compartment with the axon and converts the incoming synaptic voltage changes into a temporally precise action potential (AP) output code. Although axons often emanate directly from the soma, they may also originate more distally from a dendrite, the implications of which are not well-understood. Here, we show that one-third of the thick-tufted layer 5 pyramidal neurons have an axon originating from a dendrite and are characterized by a reduced dendritic complexity and thinner main apical dendrite. Unexpectedly, the rising phase of somatic APs is electrically indistinguishable between neurons with a somatic or a dendritic axon origin. Cable analysis of the neurons indicated that the axonal axial current is inversely proportional to the AIS distance, denoting the path length between the soma and the start of the AIS, and to produce invariant somatic APs, it must scale with the local somatodendritic capacitance. In agreement, AIS distance inversely correlates with the apical dendrite diameter, and model simulations confirmed that the covariation suffices to normalize the somatic AP waveform. Therefore, in pyramidal neurons, the AIS location is finely tuned with the somatodendritic capacitive load, serving as a homeostatic regulation of the somatic AP in the face of diverse neuronal morphologies.

  14. Blast wave exposure impairs memory and decreases axon initial segment length.

    Science.gov (United States)

    Baalman, Kelli L; Cotton, R James; Rasband, S Neil; Rasband, Matthew N

    2013-05-01

    Exposure to a blast wave has been proposed to cause mild traumatic brain injury (mTBI), with symptoms including altered cognition, memory, and behavior. This idea, however, remains controversial, and the mechanisms of blast-induced brain injury remain unknown. To begin to resolve these questions, we constructed a simple compressed air shock tube, placed rats inside the tube, and exposed them to a highly reproducible and controlled blast wave. Consistent with the generation of a mild injury, 2 weeks after exposure to the blast, we found that motor performance was unaffected, and a panel of common injury markers showed little or no significant changes in expression in the cortex, corpus callosum, or hippocampus. Similarly, we were unable to detect elevated spectrin breakdown products in brains collected from blast-exposed rats. Using an object recognition task, however, we found that rats exposed to a blast wave spent significantly less time exploring a novel object when compared with control rats. Intriguingly, we also observed a significant shortening of the axon initial segment (AIS) in both the cortex and hippocampus of blast-exposed rats, suggesting altered neuronal excitability after exposure to a blast. A computational model showed that shortening the AIS increased both threshold and the interspike interval of repetitively firing neurons. These results support the conclusion that exposure to a single blast wave can lead to mTBI with accompanying cognitive impairment and subcellular changes in the molecular organization of neurons.

  15. An evaluation of the out-segment component of the initial teacher ...

    African Journals Online (AJOL)

    The study examined the out-segment component of the 3-Year Teacher Training College Programme with the intent of identifying its prospects and challenges The survey method involving the use of questionnaire and interviews were used to collect data on views on the out-segment as perceived by some stakeholders ...

  16. Initial complications and factors related to prehospital mortality in acute myocardial infarction with ST segment elevation.

    Science.gov (United States)

    Rosell-Ortiz, Fernando; Mellado-Vergel, Francisco J; Fernández-Valle, Patricia; González-Lobato, Ismael; Martínez-Lara, Manuela; Ruiz-Montero, María M; Romero-Morales, Francisco; Vivar Díaz, Itziar; García-Alcántara, Ángel; García del Águila, Javier

    2015-07-01

    Hospital mortality in myocardial infarction ST-elevation myocardial infarction has decreased in recent years, in contrast to prehospital mortality. Our objective was to determine initial complications and factors related to prehospital mortality in patients with acute myocardial infarction with ST segment elevation (STEMI). Observational study based on a prospective continuous register of patients of any age attended by out-of-hospital emergency teams in Andalusia between January 2006 and June 2009. This includes patients with acute coronary syndrome-like symptoms whose initial ECG showed ST elevation or presumably new left bundle branch block (LBBB). Epidemiological, prehospital data and final diagnostic were recorded. The study included all patients with STEMI on the register, without age restrictions. Forward stepwise logistic regression analysis was performed to control for confounders. A total of 2528 patients were included, 24% were women. Mean age 63.4±13.4 years; 16.7% presented atypical clinical symptoms. Initial complications: ventricular fibrillation (VF) 8.4%, severe bradycardia 5.8%, third-degree atrial-ventricular (AV) block 2.4% and hypotension 13.5%. Fifty-two (2.1%) patients died before reaching hospital. Factors associated with prehospital mortality were female sex (OR 2.36, CI 1.28 to 4.33), atypical clinical picture (OR 2.31, CI 1.21 to 4.41), hypotension (OR 4.95, CI 2.60 to 9.20), LBBB (OR 4.29, CI 1.71 to 10.74), extensive infarction (ST elevation in ≥5 leads) (OR 2.53, CI 1.28 to 5.01) and VF (OR 2.82, CI 1.38 to 5.78). A significant proportion of patients with STEMI present early complications in the prehospital setting, and some die before reaching hospital. Prehospital mortality was associated with female sex and atypical presentation, as pre-existing conditions, and hypotension, extensive infarction, LBBB and VF on emergency team attendance. Published by the BMJ Publishing Group Limited. For permission to use (where not already

  17. Anatomically anchored template-based level set segmentation: application to quadriceps muscles in MR images from the Osteoarthritis Initiative.

    Science.gov (United States)

    Prescott, Jeffrey W; Best, Thomas M; Swanson, Mark S; Haq, Furqan; Jackson, Rebecca D; Gurcan, Metin N

    2011-02-01

    In this paper, we present a semi-automated segmentation method for magnetic resonance images of the quadriceps muscles. Our method uses an anatomically anchored, template-based initialization of the level set-based segmentation approach. The method only requires the input of a single point from the user inside the rectus femoris. The templates are quantitatively selected from a set of images based on modes in the patient population, namely, sex and body type. For a given image to be segmented, a template is selected based on the smallest Kullback-Leibler divergence between the histograms of that image and the set of templates. The chosen template is then employed as an initialization for a level set segmentation, which captures individual anatomical variations in the image to be segmented. Images from 103 subjects were analyzed using the developed method. The algorithm was trained on a randomly selected subset of 50 subjects (25 men and 25 women) and tested on the remaining 53 subjects. The performance of the algorithm on the test set was compared against the ground truth using the Zijdenbos similarity index (ZSI). The average ZSI means and standard deviations against two different manual readers were as follows: rectus femoris, 0.78 ± 0.12; vastus intermedius, 0.79 ± 0.10; vastus lateralis, 0.82 ± 0.08; and vastus medialis, 0.69 ± 0.16.

  18. An evaluation of the out-segment component of the initial teacher ...

    African Journals Online (AJOL)

    A sample of 510 stakeholders comprising 56 link coordinators, 56 mentors, 42 Principals, 100 headteachers, 168 mentees, 84 community members and 10 Regional Education officers were selected through purposive and random sampling techniques. The study concluded that in spite of challenges facing the out-segment ...

  19. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoyi; Li, Dongye [Capital Medical University and Beijing Institute for Brain Disorders, Center for Brain Disorders Research, Beijing (China); Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Zhao, Huilin [Shanghai Jiao Tong University, Department of Radiology, Renji Hospital, School of Medicine, Shanghai (China); Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Cui, Yuanyuan [PLA General Hospital, Department of Radiology, Beijing (China); Zhou, Zechen [Philips Research China, Healthcare Department, Beijing (China); Yuan, Chun [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); University of Washington, Department of Radiology, Seattle, WA (United States); Zhao, Xihai [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Beijing Institute for Brain Disorders, Center for Stroke, Beijing (China)

    2017-05-15

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  20. Some Properties of Fuzzy Soft Proximity Spaces

    Science.gov (United States)

    Demir, İzzettin; Özbakır, Oya Bedre

    2015-01-01

    We study the fuzzy soft proximity spaces in Katsaras's sense. First, we show how a fuzzy soft topology is derived from a fuzzy soft proximity. Also, we define the notion of fuzzy soft δ-neighborhood in the fuzzy soft proximity space which offers an alternative approach to the study of fuzzy soft proximity spaces. Later, we obtain the initial fuzzy soft proximity determined by a family of fuzzy soft proximities. Finally, we investigate relationship between fuzzy soft proximities and proximities. PMID:25793224

  1. Geomorphic Segmentation, Hydraulic Geometry, and Hydraulic Microhabitats of the Niobrara River, Nebraska - Methods and Initial Results

    Science.gov (United States)

    Alexander, Jason S.; Zelt, Ronald B.; Schaepe, Nathaniel J.

    2009-01-01

    The Niobrara River of Nebraska is a geologically, ecologically, and economically significant resource. The State of Nebraska has recognized the need to better manage the surface- and ground-water resources of the Niobrara River so they are sustainable in the long term. In cooperation with the Nebraska Game and Parks Commission, the U.S. Geological Survey is investigating the hydrogeomorphic settings and hydraulic geometry of the Niobrara River to assist in characterizing the types of broad-scale physical habitat attributes that may be of importance to the ecological resources of the river system. This report includes an inventory of surface-water and ground-water hydrology data, surface water-quality data, a longitudinal geomorphic segmentation and characterization of the main channel and its valley, and hydraulic geometry relations for the 330-mile section of the Niobrara River from Dunlap Diversion Dam in western Nebraska to the Missouri River confluence. Hydraulic microhabitats also were analyzed using available data from discharge measurements to demonstrate the potential application of these data and analysis methods. The main channel of the Niobrara was partitioned into three distinct fluvial geomorphic provinces: an upper province characterized by open valleys and a sinuous, equiwidth channel; a central province characterized by mixed valley and channel settings, including several entrenched canyon reaches; and a lower province where the valley is wide, yet restricted, but the river also is wide and persistently braided. Within the three fluvial geomorphic provinces, 36 geomorphic segments were identified using a customized, process-orientated classification scheme, which described the basic physical characteristics of the Niobrara River and its valley. Analysis of the longitudinal slope characteristics indicated that the Niobrara River longitudinal profile may be largely bedrock-controlled, with slope inflections co-located at changes in bedrock type at

  2. Trafficking of Kv2.1 Channels to the Axon Initial Segment by a Novel Nonconventional Secretory Pathway

    DEFF Research Database (Denmark)

    Jensen, Camilla Stampe; Watanabe, Shoji; Stas, Jeroen Ingrid

    2017-01-01

    the localization of Kv2.1 in these two different membrane compartments in cultured rat hippocampal neurons of mixed sex. Our data uncover a unique ability of Kv2.1 channels to use two molecularly distinct trafficking pathways to accomplish this. Somatodendritic Kv2.1 channels are targeted by the conventional...... secretory pathway, whereas axonal Kv2.1 channels are targeted by a nonconventional trafficking pathway independent of the Golgi apparatus. We further identified a new AIS trafficking motif in the C-terminus of Kv2.1, and show that putative phosphorylation sites in this region are critical for the restricted.......SIGNIFICANCE STATEMENT Our study uncovered a novel mechanism that targets the Kv2.1 voltage-gated potassium channel to two distinct trafficking pathways and two distinct subcellular destinations: the somatodendritic plasma membrane and that of the axon initial segment. We also identified a distinct motif, including...

  3. Distal and proximal family predictors of adolescents' smoking initiation and development: A longitudinal latent curve model analysis

    Directory of Open Access Journals (Sweden)

    Tjora Tore

    2011-12-01

    Full Text Available Abstract Background Studies on adolescent smoking indicate that the smoking behaviours of their parents, siblings and friends are significant micro-level predictors. Parents' socioeconomic status (SES is an important macro-level predictor. We examined the longitudinal relationships between these predictors and the initiation and development of adolescents' smoking behaviour in Norway. Methods We employed data from The Norwegian Longitudinal Health Behaviour Study (NLHB, in which participants were followed from the age of 13 to 30. We analysed data from the first 5 waves, covering the age span from 13 to 18, with latent curve modeling (LCM. Results Smoking rates increased from 3% to 31% from age 13 to age 18. Participants' smoking was strongly associated with their best friends' smoking. Parental SES, parents' smoking and older siblings' smoking predicted adolescents' initial level of smoking. Furthermore, the same variables predicted the development of smoking behaviour from age 13 to 18. Parents' and siblings' smoking behaviours acted as mediators of parents' SES on the smoking habits of adolescents. Conclusions Parents' SES was significantly associated, directly and indirectly, with both smoking initiation and development. Parental and older siblings' smoking behaviours were positively associated with both initiation and development of smoking behaviour in adolescents. There were no significant gender differences in these associations.

  4. Distal and proximal family predictors of adolescents' smoking initiation and development: A longitudinal latent curve model analysis

    Science.gov (United States)

    2011-01-01

    Background Studies on adolescent smoking indicate that the smoking behaviours of their parents, siblings and friends are significant micro-level predictors. Parents' socioeconomic status (SES) is an important macro-level predictor. We examined the longitudinal relationships between these predictors and the initiation and development of adolescents' smoking behaviour in Norway. Methods We employed data from The Norwegian Longitudinal Health Behaviour Study (NLHB), in which participants were followed from the age of 13 to 30. We analysed data from the first 5 waves, covering the age span from 13 to 18, with latent curve modeling (LCM). Results Smoking rates increased from 3% to 31% from age 13 to age 18. Participants' smoking was strongly associated with their best friends' smoking. Parental SES, parents' smoking and older siblings' smoking predicted adolescents' initial level of smoking. Furthermore, the same variables predicted the development of smoking behaviour from age 13 to 18. Parents' and siblings' smoking behaviours acted as mediators of parents' SES on the smoking habits of adolescents. Conclusions Parents' SES was significantly associated, directly and indirectly, with both smoking initiation and development. Parental and older siblings' smoking behaviours were positively associated with both initiation and development of smoking behaviour in adolescents. There were no significant gender differences in these associations. PMID:22152017

  5. Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom

    Directory of Open Access Journals (Sweden)

    Yamashiro T

    2015-09-01

    Full Text Available Tsuneo Yamashiro,1 Maho Tsubakimoto,1 Yukihiro Nagatani,2 Hiroshi Moriya,3 Kotaro Sakuma,3 Shinsuke Tsukagoshi,4 Hiroyasu Inokawa,5 Tatsuya Kimoto,5 Ryuichi Teramoto,6 Sadayuki Murayama1 1Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa; 2Department of Radiology, Shiga University of Medical Science, Otsu; 3Department of Radiology, Ohara General Hospital, Fukushima; 4CT Systems Division, 5Center for Medical Research and Development, Toshiba Medical Systems Corporation, Otawara; 6Corporate Manufacturing Engineering Center, Toshiba Corporation, Yokohama, Japan Background: The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT and our research software. Methods: A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute. This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%. The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale. Results: It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB. From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of

  6. Distal and proximal family predictors of adolescents' smoking initiation and development: A longitudinal latent curve model analysis

    OpenAIRE

    Tjora Tore; Hetland Jørn; Aarø Leif; Øverland Simon

    2011-01-01

    Background: Studies on adolescent smoking indicate that the smoking behaviours of their parents, siblings and friends are significant micro-level predictors. Parents’ socioeconomic status (SES) is an important macro-level predictor. We examined the longitudinal relationships between these predictors and the initiation and development of adolescents’ smoking behaviour in Norway. Methods: We employed data from The Norwegian Longitudinal Health Behaviour Study (NLHB), in which par...

  7. Intron DNA Sequences Can Be More Important Than the Proximal Promoter in Determining the Site of Transcript Initiation.

    Science.gov (United States)

    Gallegos, Jenna E; Rose, Alan B

    2017-04-01

    To more precisely define the positions from which certain intronic regulatory sequences increase mRNA accumulation, the effect of a UBIQUITIN intron on gene expression was tested from six different positions surrounding the transcription start site (TSS) of a reporter gene fusion in Arabidopsis thaliana The intron increased expression from all transcribed positions but had no effect when upstream of the 5'-most TSS. While this implies that the intron must be transcribed to increase expression, the TSS changed when the intron was located in the 5'-untranslated region (UTR), suggesting that the intron affects transcription initiation. Remarkably, deleting 303 nucleotides of the promoter including all known TSSs and all but 18 nucleotides of the 5'-UTR had virtually no effect on the level of gene expression as long as an intron containing stimulatory sequences was included. Instead, transcription was initiated in normally untranscribed sequences the same distance upstream of the intron as when the promoter was intact. These results suggest that certain intronic DNA sequences play unexpectedly large roles in directing transcription initiation and constitute a previously unrecognized type of downstream regulatory element for genes transcribed by RNA polymerase II. © 2017 American Society of Plant Biologists. All rights reserved.

  8. No Pasaran! Role of the axon initial segment in the regulation of protein transport and the maintenance of axonal identity.

    Science.gov (United States)

    Leterrier, Christophe; Dargent, Bénédicte

    2014-03-01

    The transmission of information in the brain depends on the highly polarized architecture of neurons. A number of cellular transport processes support this organization, including active targeting of proteins and passive corralling between compartments. The axon initial segment (AIS), which separates the somatodendritic and axonal compartments, has a key role in neuronal physiology, as both the initiation site of action potentials and the gatekeeper of the axonal arborization. Over the years, the AIS main components and their interactions have been progressively unraveled, as well as their role in the AIS assembly and maintenance. Two mechanisms have been shown to contribute to the regulation of protein transport at the AIS: a surface diffusion barrier and an intracellular traffic filter. However, a molecular understanding of these processes is still lacking. In the view of recent results on the AIS cytoskeleton structure, we will discuss how a better knowledge of the AIS architecture can help understanding its role in the regulation of protein transport and the maintenance of axonal identity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Targeted Expression of Channelrhodopsin-2 to the Axon Initial Segment Alters the Temporal Firing Properties of Retinal Ganglion Cells.

    Directory of Open Access Journals (Sweden)

    Zhifei Zhang

    Full Text Available The axon initial segment (AIS is essential for initiating action potentials and maintaining neuronal excitability in axon-bearing neurons in the CNS. There is increasing interest in the targeting of optogenetic tools to subcellular compartments, including the AIS, to gain precise control of neuronal activity for basic research and clinical applications. In particular, targeted expression of optogenetic tools in retinal ganglion cells (RGCs has been explored as an approach for restoring vision after photoreceptor degeneration. Thus, understanding the effects of such targeting on spiking abilities and/or patterns is important. Here, we examined the effects of recombinant adeno-associated virus (rAAV-mediated targeted expression of channelrhodopsin-2 (ChR2-GFP with a NaV channel motif in mouse RGCs. We found that this targeted expression disrupted NaV channel clustering at the AIS and converted the spike firing patterns of RGCs from sustained to transient. Our results suggest that the clustering of membrane channels, including NaV channels, at the AIS is important for the ability of RGCs to generate sustained spike firing. Additionally, the targeting of optogenetic tools to the AIS with the NaV channel motif may offer a way to create transient light responses in RGCs for vision restoration.

  10. Action potential generation at an axon initial segment-like process in the axonless retinal AII amacrine cell.

    Science.gov (United States)

    Wu, Chaowen; Ivanova, Elena; Cui, Jinjuan; Lu, Qi; Pan, Zhuo-Hua

    2011-10-12

    In axon-bearing neurons, action potentials conventionally initiate at the axon initial segment (AIS) and are important for neuron excitability and cell-to-cell communication. However in axonless neurons, spike origin has remained unclear. Here we report in the axonless, spiking AII amacrine cell of the mouse retina a dendritic process sharing organizational and functional similarities with the AIS. This process was revealed through viral-mediated expression of channelrhodopsin-2-GFP with the AIS-targeting motif of sodium channels (Na(v)II-III). The AII processes showed clustering of voltage-gated Na+ channel 1.1 (Na(v)1.1) as well as AIS markers ankyrin-G and neurofascin. Furthermore, Na(v)II-III targeting disrupted Na(v)1.1 clustering in the AII process, which drastically decreased Na+ current and abolished the ability of the AII amacrine cell to generate spiking. Our findings indicate that, despite lacking an axon, spiking in the axonless neuron can originate at a specialized AIS-like process.

  11. Preferential targeting of Nav1.6 voltage-gated Na+ Channels to the axon initial segment during development.

    Directory of Open Access Journals (Sweden)

    Elizabeth J Akin

    Full Text Available During axonal maturation, voltage-gated sodium (Nav channels accumulate at the axon initial segment (AIS at high concentrations. This localization is necessary for the efficient initiation of action potentials. The mechanisms underlying channel trafficking to the AIS during axonal development have remained elusive due to a lack of Nav reagents suitable for high resolution imaging of channels located specifically on the cell surface. Using an optical pulse-chase approach in combination with a novel Nav1.6 construct containing an extracellular biotinylation domain we demonstrate that Nav1.6 channels are preferentially inserted into the AIS membrane during neuronal development via direct vesicular trafficking. Single-molecule tracking illustrates that axonal channels are immediately immobilized following delivery, while channels delivered to the soma are often mobile. Neither a Nav1.6 channel lacking the ankyrin-binding motif nor a chimeric Kv2.1 channel containing the Nav ankyrinG-binding domain show preferential AIS insertion. Together these data support a model where ankyrinG-binding is required for preferential Nav1.6 insertion into the AIS plasma membrane. In contrast, ankyrinG-binding alone does not confer the preferential delivery of proteins to the AIS.

  12. Prophylactic vertebral cement augmentation at the uppermost instrumented vertebra and rostral adjacent vertebra for the prevention of proximal junctional kyphosis and failure following long-segment fusion for adult spinal deformity.

    Science.gov (United States)

    Ghobrial, George M; Eichberg, Daniel G; Kolcun, John Paul G; Madhavan, Karthik; Lebwohl, Nathan H; Green, Barth A; Gjolaj, Joseph P

    2017-10-01

    Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are common problems after long-segment (>5 levels) thoracolumbar instrumented fusions in the treatment of adult spinal deformity (ASD). No specific surgical strategy has definitively been shown to lower the risk of PJK as the result of a multifactorial etiology. The study aimed to assess the incidence of PJK and PJF in patients treated with prophylactic polymethylmethacrylate (PMMA) cement augmentation at the uppermost instrumented vertebrae (UIV) and rostral adjacent vertebrae (UIV+1). This is a retrospective cohort-matched surgical case series at an academic institutional setting. Eighty-five adult patients over a 16-year enrollment period were identified with long-segment (>5 levels) posterior thoracolumbar instrumented fusions for ASD. Primary outcomes measures were PJK magnitude and PJF formation. Secondary outcomes measures were spinopelvic parameters, as well as global and regional sagittal alignment. The impact of adjunctive PMMA use in long-segment (≥5 levels) fusion for ASD was assessed in adult patients aged 18 and older. Patients were included with at least one of the following: lumbar scoliosis >20°, pelvic tilt >25°, sagittal vertical axis >5 cm, central sacral vertical line >2 cm, and thoracic kyphosis >60°. The frequency of PJF and the magnitude of PJK were measured radiographically preoperatively, postoperatively, and at maximum follow-up in controls (Group A) and PMMA at the UIV and UIV+1 (Group B). Eighty-five patients (64±11.1 years) with ASD were identified: 47 control patients (58±10.6) and 38 patients (71±6.8) treated with PMMA at the UIV and UIV+1. The mean follow-up was 27.9 and 24.2 months in Groups A and B, respectively (p=.10). Preoperative radiographic parameters were not significantly different, except the pelvic tilt which was greater in Group A (26.6° vs. 31.4°, p=.03). Postoperatively, the lumbopelvic mismatch was greater in Group B (14.6° vs. 7

  13. Proximal Hypospadias

    Science.gov (United States)

    Kraft, Kate H.; Shukla, Aseem R.; Canning, Douglas A.

    2011-01-01

    Hypospadias results from abnormal development of the penis that leaves the urethral meatus proximal to its normal glanular position. Meatal position may be located anywhere along the penile shaft, but more severe forms of hypospadias may have a urethral meatus located at the scrotum or perineum. The spectrum of abnormalities may also include ventral curvature of the penis, a dorsally redundant prepuce, and atrophic corpus spongiosum. Due to the severity of these abnormalities, proximal hypospadias often requires more extensive reconstruction in order to achieve an anatomically and functionally successful result. We review the spectrum of proximal hypospadias etiology, presentation, correction, and possible associated complications. PMID:21516286

  14. A Syllable Segmentation, Letter-Sound, and Initial-Sound Intervention with Students Who Are Deaf or Hard of Hearing and Use Sign Language

    Science.gov (United States)

    Tucci, Stacey L.; Easterbrooks, Susan R.

    2015-01-01

    This study investigated children's acquisition of three aspects of an early literacy curriculum, "Foundations for Literacy" ("Foundations"), designed specifically for prekindergarten students who are deaf or hard of hearing (DHH): syllable segmentation, identification of letter-sound correspondences, and initial-sound…

  15. Renal fibrosis: Primacy of the proximal tubule.

    Science.gov (United States)

    Gewin, Leslie S

    2018-02-06

    Tubulointerstitial fibrosis (TIF) is the hallmark of chronic kidney disease and best predictor of renal survival. Many different cell types contribute to TIF progression including tubular epithelial cells, myofibroblasts, endothelia, and inflammatory cells. Previously, most of the attention has centered on myofibroblasts given their central importance in extracellular matrix production. However, emerging data focuses on how the response of the proximal tubule, a specialized epithelial segment vulnerable to injury, plays a central role in TIF progression. Several proximal tubular responses such as de-differentiation, cell cycle changes, autophagy, and metabolic changes may be adaptive initially, but can lead to maladaptive responses that promote TIF both through autocrine and paracrine effects. This review discusses the current paradigm of TIF progression and the increasingly important role of the proximal tubule in promoting TIF both in tubulointerstitial and glomerular injuries. A better understanding and appreciation of the role of the proximal tubule in TIF has important implications for therapeutic strategies to halt chronic kidney disease progression. Copyright © 2017 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

  16. Initiation and development of the Kivu rift segment in Central Africa by reactivating un-favorably oriented structural weaknesses

    Science.gov (United States)

    Delvaux, Damien; Smets, Benoît

    2015-04-01

    The Kivu rift region forms the central segment of the western branch of the East African rift system, between the northern termination of the Tanganyika rift and the southern extension of the Edward-George rift. Its structure and geological evolution has been revised in the light of a compilation of existing data on earthquake epicenters, focal depth, focal mechanisms, thermal springs and neotectonic faults. It has long been shown that the link between the Kivu rift basin and the Northern termination of the Tanganyika rift basin forms an accommodation zone in which the Rusizi tectonic depression occupies a central place (Ebinger, 1989). In addition, our compilation suggests that the NNE-trending Kivu rift basin and the N-S northern half of the Tanganyika rift basin initiated as separated, partly overlapping and differently oriented basins. The orientation and development of the Kivu rift basin was controlled by an inferred Mid-Proterozoic crustal shear zone and a Pan-African reverse fault front. It was not optimally oriented with the general (first-order) stress field characterized by roughly E-W extension. In a later stage, the more optimally N-S oriented North Tanganyika basin progressed towards the North and connected to Kivu rift in its middle in a region now occupied by the town of Bukavu. This accommodation zone is marked by Quaternary volcanism, warm thermal springs, frequent and relatively shallow seismicity. The southwestern part of the Kivu rift became progressively abandoned but it is still seismically active and hosts a number of warm thermal springs. This particular architecture influences the present-day stress field. This work is a contribution to the Belgian GeoRisCA project. Ebinger, C.J. 1989. Geometric and kinematic development of border faults and accommodation zones, Kivu-Rusizi Rift, Africa. Tectonics, 8, 117-133

  17. Endovascular treatment in proximal and intracranial carotid occlusion 9 hours after symptom onset

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowska, Malgorzata M.; Michels, Peter; Mueller-Jensen, Axel [Asklepios Clinic Altona, Department of Neurology, Hamburg (Germany); Leppien, Andreas; Eckert, Bernd [Asklepios Clinic Altona, Department of Neuroradiology, Hamburg (Germany)

    2008-07-15

    A debate is emerging over whether the treatment time window in acute stroke can be extended beyond 6 h if penumbral tissue can be identified. Treatment decisions are very difficult in cases of tandem proximal carotid occlusion with arterioarterial intracranial embolism. We enter this debate with the present report on a case of atherosclerotic proximal carotid occlusion and resulting periocclusional carotid T embolism that was successfully treated 9 h after symptom onset. The case of a 68-year-old man with fluctuating symptoms of right-hemispheric stroke is presented (NIHSS score 12-20 on admission). CT angiography demonstrated proximal carotid occlusion and periocclusional embolism of the entire internal carotid artery (ICA) including the carotid T segment. Penumbral tissue was diagnosed by nonenhanced and perfusion CT imaging 7.5 h after symptom onset. Treatment was initiated 9 h after symptom onset by passing the proximal occlusion with a microcatheter and local administration of recombinant tissue plasminogen activator (rt-PA) into the carotid T segment at the level of posterior communicating artery (PCoA) origin. Recanalization of the ICA and middle cerebral artery was accomplished within 1 h by flow establishment via the PCoA. The atherosclerotic proximal ICA occlusion was not stented due to the risk of embolism from remnant thrombi in the petrous and cavernous ICA segments. Follow-up MRI showed only mild haemorrhagic infarct transformation of the initial infarct core. The patient was discharged from hospital 18 days after treatment with NIHSS score 5. If penumbral tissue can be conclusively identified, endovascular treatment in proximal and intracranial tandem occlusion can be successful, even in treatments initiated 6-9 h after stroke onset. If the intracranial flow after recanalization can be established via the circle of Willis, the underlying proximal ICA occlusion may not require treatment. (orig.)

  18. Magnetic resonance image segmentation using semi-automated software for quantification of knee articular cartilage - initial evaluation of a technique for paired scans

    Energy Technology Data Exchange (ETDEWEB)

    Brem, M.H. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Friedrich-Alexander-University Erlangen Nurenberg, Division of Orthopaedic and Trauma Surgery, Department of Surgery, Erlangen (Germany); Lang, P.K.; Neumann, G.; Schlechtweg, P.M.; Yoshioka, H.; Pappas, G.; Duryea, J. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Schneider, E. [LLC, SciTrials, Rocky River, OH (United States); Cleveland Clinic, Imaging Institute, Cleveland, OH (United States); Jackson, R.; Yu, J. [Ohio State University, Diabetes and Metabolism and Radiology, Department of Endocrinology, Columbus, OH (United States); Eaton, C.B. [Center for Primary Care and Prevention and the Warren Alpert Medical School of Brown University, Memorial Hospital of Rhode Island, Providence, RI (United States); Hennig, F.F. [Friedrich-Alexander-University Erlangen Nurenberg, Division of Orthopaedic and Trauma Surgery, Department of Surgery, Erlangen (Germany)

    2009-05-15

    Software-based image analysis is important for studies of cartilage changes in knee osteoarthritis (OA). This study describes an evaluation of a semi-automated cartilage segmentation software tool capable of quantifying paired images for potential use in longitudinal studies of knee OA. We describe the methodology behind the analysis and demonstrate its use by determination of test-retest analysis precision of duplicate knee magnetic resonance imaging (MRI) data sets. Test-retest knee MR images of 12 subjects with a range of knee health were evaluated from the Osteoarthritis Initiative (OAI) pilot MR study. Each subject was removed from the magnet between the two scans. The 3D DESS (sagittal, 0.456 mm x 0.365 mm, 0.7 mm slice thickness, TR 16.5 ms, TE 4.7 ms) images were obtained on a 3-T Siemens Trio MR system with a USA Instruments quadrature transmit-receive extremity coil. Segmentation of one 3D-image series was first performed and then the corresponding retest series was segmented by viewing both image series concurrently in two adjacent windows. After manual registration of the series, the first segmentation cartilage outline served as an initial estimate for the second segmentation. We evaluated morphometric measures of the bone and cartilage surface area (tAB and AC), cartilage volume (VC), and mean thickness (ThC.me) for medial/lateral tibia (MT/LT), total femur (F) and patella (P). Test-retest reproducibility was assessed using the root-mean square coefficient of variation (RMS CV%). For the paired analyses, RMS CV % ranged from 0.9% to 1.2% for VC, from 0.3% to 0.7% for AC, from 0.6% to 2.7% for tAB and 0.8% to 1.5% for ThC.me. Paired image analysis improved the measurement precision of cartilage segmentation. Our results are in agreement with other publications supporting the use of paired analysis for longitudinal studies of knee OA. (orig.)

  19. Segmentation and classification models validation area mapping of peat lands as initial value of Fuzzy Kohonen Clustering Network

    Science.gov (United States)

    Erwin; Saparudin; Fachrurrozi, Muhammad

    2017-04-01

    Ogan Komering Ilir (OKI) is located at the eastern of South Sumatra Province, 2030‧-4015‧ latitude and 104020‧-106000‧ longitude. Digital image of land was captured from Landsat 8 satellite path 124/row 062. Landsat 8 is new generation satellite which has two sensors, Operation Land Manager (OLI) and Thermal Infra-Red Sensor (TIRS). In pre-processing step, there are a geometric correction, radiometric correction, and cropping of the digital images which resulting coordinated geography. Classification uses maximum likelihood estimator algorithm. In segmentation process and classification, grey value spread is into evenly after applying histogram technique. The results of entropy value are7.42 which is the highest of result image classification, then the smallest entropy value in the result of correction mapping are 6.39. The three of them prove that they have enough high entropy value. Then the result of peatlands classification is given overall accuracy value = = 94.0012% and overall kappa value = 0.9230 so the result of classification can be considered to be right.

  20. Six-Month Results From the Initial Randomized Study of the Ranger Paclitaxel-Coated Balloon in the Femoropopliteal Segment.

    Science.gov (United States)

    Bausback, Yvonne; Willfort-Ehringer, Andrea; Sievert, Horst; Geist, Volker; Lichtenberg, Michael; Del Giudice, Costantino; Sauguet, Antoine; Diaz-Cartelle, Juan; Marx, Claudia; Ströbel, Armin; Schult, Ingolf; Scheinert, Dierk

    2017-08-01

    To evaluate the performance of the Ranger paclitaxel-coated balloon vs uncoated balloon angioplasty for femoropopliteal lesions. Between January 2014 and October 2015, the prospective, randomized RANGER SFA study ( ClinicalTrials.gov identifier NCT02013193) enrolled 105 patients with symptomatic lower limb ischemia (Rutherford category 2-4) and stenotic lesions in the nonstented femoropopliteal segment at 10 European centers. Seventy-one patients (mean age 68±8 years; 53 men) were enrolled in the Ranger drug-coated balloon (DCB) arm and 34 patients (mean age 67±9 years; 23 men) were assigned to the control group. Six-month analysis included angiographic late lumen loss and safety and clinical outcomes assessments. Baseline characteristics of the DCB and control groups were similar, as were lesion lengths (68±46 vs 60±48 mm; p=0.731), severity of calcification (p=0.236), and the prevalence of occlusions (34% vs 34%; p>0.999). At 6 months, late lumen loss was significantly less for the DCB group vs controls (-0.16±0.99 vs 0.76±1.4; p=0.002). The DCB group had significantly greater freedom from binary restenosis (92% vs 64%; p=0.005) and primary patency rates (87% vs 60%; p=0.014). Target lesion revascularization rates were 5.6% in the DCB group and 12% in the control group (p=0.475). No target limb amputations or device-related deaths occurred in either group. Six-month results suggest that Ranger DCB treatment effectively inhibited restenosis in symptomatic femoropopliteal disease, resulting in improved vessel patency and a low revascularization rate in the short term compared with uncoated balloon angioplasty.

  1. Proximal sacral deformity: a common element in lytic isthmic spondylolisthesis at L5 and in degenerative spondylolisthesis at L4-L5 segment. Two apparently very different etiopathogenic entities.

    Science.gov (United States)

    Gallego-Goyanes, A; Barahona-Lorenzo, D; Díez-Ulloa, M A

    A radiographic study was carried out to investigate the relationship between proximal sacral sagittal anatomy (either kyphosis or lordosis) and either isthmic or degenerative spondylolisthesis. In addition, we studied whether there is a relationship between proximal sacral kyphosis and the degree of such listhesis in the case of L5 isthmic spondylolisthesis. Lateral standing x-rays were used from 173 patients, ninety of whom had degenerative spondylolisthesis L4-L5, and eighty-three an isthmic spondylolisthesis of L5 (67 low-grade and 16 high-grade) and compared with a control group of 100 patients adjusted by age and gender, without any type of spondylolisthesis. Listhesis was graded using Meyerding's classification and the proximal sacral kyphosis angle (CSP) was measured between S1 and S2 posterior walls, according to Harrison's method. In our series, there was a proximal sacral kyphosis in both types of spondylolisthesis, greater in the lytic type. By contrast, the control group had a proximal sacral lordosis. The differences were statistically significant. Therefore, we concluded that there was a proximal sacral kyphosis in patients with both degenerative and isthmic lytic spondylolisthesis, but with our results, we were not able to ascertain whether it is a cause or a consequence of this listhesis. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Proximal renal tubular acidosis

    Science.gov (United States)

    Renal tubular acidosis - proximal; Type II RTA; RTA - proximal; Renal tubular acidosis type II ... by alkaline substances, mainly bicarbonate. Proximal renal tubular acidosis (Type II RTA) occurs when bicarbonate is not ...

  3. Effect of end segment on physicochemical properties and platelet compatibility of poly(propylene glycol)-initiated poly(methyl methacrylate).

    Science.gov (United States)

    Fukuda, Chihiro; Yahata, Chie; Kinoshita, Takuya; Watanabe, Takafumi; Tsukamoto, Hideo; Mochizuki, Akira

    2017-10-01

    It is well known that polyether-based copolymers have good blood compatibility, although many mechanisms have been proposed to explain their favorable performance. Our objective in carrying out the present study was to obtain a better understanding of the effect of the (poly)ether segment on blood compatibility. Therefore, we synthesized poly(propylene glycol) (PPG)-based initiators for atom transfer polymerization, where the number of propylene glycol (PG) units in the PPG (Pn(PG) was varied from 1 to 94. Methyl methacrylate (MMA) was polymerized using the initiators, resulting in the formation of polyMMAs with a PG-based ether part at the polymer terminal. We mainly investigated the effects of Pn(PG) on the surface properties and platelet compatibility of the PPG-polyMMA. X-ray photoelectron spectroscopy and surface contact angle (CA) analysis revealed the exposure of the PG units at the surface of the polymer. The platelet compatibility of the polymers was improved compared with a commercial polyMMA, even when Pn(PG) = 1. These results suggest that PG units have an important influence on favorable blood compatibility, regardless of the Pn(PG) value. We also investigated protein adsorption behavior in terms of the amount and deformation of fibrinogen adsorbed on the polymer surface.

  4. An Initial AUV Investigation of the Morainal Bank and Ice-Proximal Submarine Processes of the Advancing Hubbard Glacier, Southeast Alaska

    Science.gov (United States)

    Lawson, D. E.; Gulick, S. P. S.; Goff, J. A.; O'Halloran, W.

    2014-12-01

    The movement of an advancing tidewater glacier occurs in concert with the morainal bank that underlies its terminus. The mechanics of motion and sedimentological processes responsible for this advance of the morainal bank with the calving terminus are not well-defined and based largely on inferences from geophysical analyses of remnant morainal banks on fjord floors. There is a general absence of in situ or direct observation of the submarine margin because it is nearly impossible to access the immediate area of the ice face by boat safely. In order to obtain such data, in June 2014 we tested the ability of a Bluefin 9M AUV (autonomous underwater vehicle) to acquire high resolution swath bathymetry and sidescan backscatter across a ~2 km long section of the ice face of Hubbard Glacier (see also Goff et al., this meeting). Additionally onboard oceanographic measurements were taken that can be compared with surface cast CTD profiles obtained during AUV deployment, including locations with subglacial discharges. The AUV test provides details on the geometry of the morainal bank and nature of the fjord wall surfaces. The decimeter-scale imagery of the seabed reveals numerous erosional and depositional bedforms and gravitational features on the morainal bank's proximal slope. Closer to the ice face, the morainal bank surface appears much coarser, with textural patterns of unknown origin, and gravel lags including boulder fields. Comparing the water depth from the AUV survey with that of NOAA bathymetric data from 2004/2006 shows the morainal bank continued to advance in pace with ice advance into fjord waters over 200m deep, water depths shoaling up to 100m near the present ice margin. The glimpse of the morainal bank afforded by the AUV test clearly demonstrated the value of this technology to ice marginal submarine investigations.

  5. FACTS: Fully Automatic CT Segmentation of a Hip Joint.

    Science.gov (United States)

    Chu, Chengwen; Chen, Cheng; Liu, Li; Zheng, Guoyan

    2015-05-01

    Extraction of surface models of a hip joint from CT data is a pre-requisite step for computer assisted diagnosis and planning (CADP) of periacetabular osteotomy (PAO). Most of existing CADP systems are based on manual segmentation, which is time-consuming and hard to achieve reproducible results. In this paper, we present a Fully Automatic CT Segmentation (FACTS) approach to simultaneously extract both pelvic and femoral models. Our approach works by combining fast random forest (RF) regression based landmark detection, multi-atlas based segmentation, with articulated statistical shape model (aSSM) based fitting. The two fundamental contributions of our approach are: (1) an improved fast Gaussian transform (IFGT) is used within the RF regression framework for a fast and accurate landmark detection, which then allows for a fully automatic initialization of the multi-atlas based segmentation; and (2) aSSM based fitting is used to preserve hip joint structure and to avoid penetration between the pelvic and femoral models. Taking manual segmentation as the ground truth, we evaluated the present approach on 30 hip CT images (60 hips) with a 6-fold cross validation. When the present approach was compared to manual segmentation, a mean segmentation accuracy of 0.40, 0.36, and 0.36 mm was found for the pelvis, the left proximal femur, and the right proximal femur, respectively. When the models derived from both segmentations were used to compute the PAO diagnosis parameters, a difference of 2.0 ± 1.5°, 2.1 ± 1.6°, and 3.5 ± 2.3% were found for anteversion, inclination, and acetabular coverage, respectively. The achieved accuracy is regarded as clinically accurate enough for our target applications.

  6. Fast sodium channel gating supports localized and efficient axonal action potential initiation.

    Science.gov (United States)

    Schmidt-Hieber, Christoph; Bischofberger, Josef

    2010-07-28

    Action potentials (APs) are initiated in the proximal axon of most neurons. In myelinated axons, a 50-times higher sodium channel density in the initial segment compared to the soma may account for this phenomenon. However, little is known about sodium channel density and gating in proximal unmyelinated axons. To study the mechanisms underlying AP initiation in unmyelinated hippocampal mossy fibers of adult mice, we recorded sodium currents in axonal and somatic membrane patches. We demonstrate that sodium channel density in the proximal axon is approximately 5 times higher than in the soma. Furthermore, sodium channel activation and inactivation are approximately 2 times faster. Modeling revealed that the fast activation localized the initiation site to the proximal axon even upon strong synaptic stimulation, while fast inactivation contributed to energy-efficient membrane charging during APs. Thus, sodium channel gating and density in unmyelinated mossy fiber axons appear to be specialized for robust AP initiation and propagation with minimal current flow.

  7. Compliance with Segment Disclosure Initiatives

    DEFF Research Database (Denmark)

    Arya, Anil; Frimor, Hans; Mittendorf, Brian

    2013-01-01

    Regulatory oversight of capital markets has intensified in recent years, with a particular emphasis on expanding financial transparency. A notable instance is efforts by the Financial Accounting Standards Board that push firms to identify and report performance of individual business units...... by increasing transparency and leveling the playing field. However, our analysis also demonstrates that in the long run, if firms are unable to use discretion in reporting to maintain their competitive edge, they may seek more destructive alternatives. Accounting for such concerns, in the long run, voluntary...

  8. Thumb proximal phalanx reconstruction with nonvascularized corticocancellous olecranon bone graft.

    Science.gov (United States)

    Soong, Maximillian

    2015-01-01

    Large segmental bone defects of the phalanges reportedly have been treated with free vascularized grafts from the hand, foot, or knee, or with nonvascularized grafts from the iliac crest. A nonvascularized structural corticocancellous graft from a local site would be advantageous. The olecranon has been used as a source of both cancellous and corticocancellous graft. The authors describe a unique case of the use of nonvascularized corticocancellous olecranon bone graft for structural purposes in a mutilating thumb injury. The patient injured the left thumb with a miter saw, resulting in a large degloving wound over a severely comminuted fracture of the proximal phalanx, with segmental bone loss between a base fragment and displaced condylar fragments. Provisional pin fixation was performed at the time of initial emergent irrigation and debridement, along with repairs of the extensor pollicis longus, radial digital nerve, and dorsal digital nerve. This was followed 3 weeks later by non-vascularized corticocancellous bone grafting from the olecranon to the proximal phalanx under regional anesthesia. The thumb was mobilized at 11 weeks, and solid union was radiographically confirmed at 6 months. The patient achieved moderate active range of motion and was able to return to work as a physical therapist. The elbow healed uneventfully and without pain or fracture at the donor site. This case shows that robust structural bone graft for the phalanges may be obtained from the nearby olecranon, under regional anesthesia, without microsurgery, and with potential advantages over the iliac crest. Copyright 2015, SLACK Incorporated.

  9. Speech segmentation in aphasia.

    Science.gov (United States)

    Peñaloza, Claudia; Benetello, Annalisa; Tuomiranta, Leena; Heikius, Ida-Maria; Järvinen, Sonja; Majos, Maria Carmen; Cardona, Pedro; Juncadella, Montserrat; Laine, Matti; Martin, Nadine; Rodríguez-Fornells, Antoni

    2015-01-01

    Speech segmentation is one of the initial and mandatory phases of language learning. Although some people with aphasia have shown a preserved ability to learn novel words, their speech segmentation abilities have not been explored. We examined the ability of individuals with chronic aphasia to segment words from running speech via statistical learning. We also explored the relationships between speech segmentation and aphasia severity, and short-term memory capacity. We further examined the role of lesion location in speech segmentation and short-term memory performance. The experimental task was first validated with a group of young adults (n = 120). Participants with chronic aphasia (n = 14) were exposed to an artificial language and were evaluated in their ability to segment words using a speech segmentation test. Their performance was contrasted against chance level and compared to that of a group of elderly matched controls (n = 14) using group and case-by-case analyses. As a group, participants with aphasia were significantly above chance level in their ability to segment words from the novel language and did not significantly differ from the group of elderly controls. Speech segmentation ability in the aphasic participants was not associated with aphasia severity although it significantly correlated with word pointing span, a measure of verbal short-term memory. Case-by-case analyses identified four individuals with aphasia who performed above chance level on the speech segmentation task, all with predominantly posterior lesions and mild fluent aphasia. Their short-term memory capacity was also better preserved than in the rest of the group. Our findings indicate that speech segmentation via statistical learning can remain functional in people with chronic aphasia and suggest that this initial language learning mechanism is associated with the functionality of the verbal short-term memory system and the integrity of the left inferior frontal region.

  10. Mineralization of the vertebral bodies in Atlantic salmon (Salmo salar L.) is initiated segmentally in the form of hydroxyapatite crystal accretions in the notochord sheath

    Science.gov (United States)

    Wang, Shou; Kryvi, Harald; Grotmol, Sindre; Wargelius, Anna; Krossøy, Christel; Epple, Mattias; Neues, Frank; Furmanek, Tomasz; Totland, Geir K

    2013-01-01

    We performed a sequential morphological and molecular biological study of the development of the vertebral bodies in Atlantic salmon (Salmo salar L.). Mineralization starts in separate bony elements which fuse to form complete segmental rings within the notochord sheath. The nucleation and growth of hydroxyapatite crystals in both the lamellar type II collagen matrix of the notochord sheath and the lamellar type I collagen matrix derived from the sclerotome, were highly similar. In both matrices the hydroxyapatite crystals nucleate and accrete on the surface of the collagen fibrils rather than inside the fibrils, a process that may be controlled by a template imposed by the collagen fibrils. Apatite crystal growth starts with the formation of small plate-like structures, about 5 nm thick, that gradually grow and aggregate to form extensive multi-branched crystal arborizations, resembling dendritic growth. The hydroxyapatite crystals are always oriented parallel to the long axis of the collagen fibrils, and the lamellar collagen matrices provide oriented support for crystal growth. We demonstrate here for the first time by means of synchroton radiation based on X-ray diffraction that the chordacentra contain hydroxyapatite. We employed quantitative real-time PCR to study the expression of key signalling molecule transcripts expressed in the cellular core of the notochord. The results indicate that the notochord not only produces and maintains the notochord sheath but also expresses factors known to regulate skeletogenesis: sonic hedgehog (shh), indian hedgehog homolog b (ihhb), parathyroid hormone 1 receptor (pth1r) and transforming growth factor beta 1 (tgfb1). In conclusion, our study provides evidence for the process of vertebral body development in teleost fishes, which is initially orchestrated by the notochord. PMID:23711083

  11. Multiset proximity spaces

    Directory of Open Access Journals (Sweden)

    A. Kandil

    2016-10-01

    Full Text Available A multiset is a collection of objects in which repetition of elements is essential. This paper is an attempt to explore the theoretical aspects of multiset by extending the notions of compact, proximity relation and proximal neighborhood to the multiset context. Examples of new multiset topologies, open multiset cover, compact multiset and many identities involving the concept of multiset have been introduced. Further, an integral examples of multiset proximity relations are obtained. A multiset topology induced by a multiset proximity relation on a multiset M has been presented. Also the concept of multiset δ- neighborhood in the multiset proximity space which furnishes an alternative approach to the study of multiset proximity spaces has been mentioned. Finally, some results on this new approach have been obtained and one of the most important results is: every T4- multiset space is semi-compatible with multiset proximity relation δ on M (Theorem 5.10.

  12. Segmental neurofibromatosis

    OpenAIRE

    Galhotra, Virat; Sheikh, Soheyl; Jindal, Sanjeev; Singla, Anshu

    2014-01-01

    Segmental neurofibromatosis is a rare disorder, characterized by neurofibromas or cafι-au-lait macules limited to one region of the body. Its occurrence on the face is extremely rare and only few cases of segmental neurofibromatosis over the face have been described so far. We present a case of segmental neurofibromatosis involving the buccal mucosa, tongue, cheek, ear, and neck on the right side of the face.

  13. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  14. Polychaete annelid (segmented worms) abundance and species composition in the proximity (6-9 km) of the Deep Water Horizon (DWH) Oil Spill in the Deep Gulf of Mexico

    Science.gov (United States)

    Qu, Fangyuan; Nunnally, Clifton C.; Lemanski, Joseph R.; Wade, Terry L.; Amon, Rainer M. W.; Rowe, Gilbert T.

    2016-07-01

    Polychaete annelids (segmented worms) dominated the macrobenthos in sediments located 6-9 km from the Deep Water Horizon (DWH) Oil Spill site five months after the event, based on nine 0.2 m2 box core samples. Numbers of species, abundance, and biodiversity indices in the polychaete taxa were significantly lower than pre-spill values from similar depths in the eastern Gulf of Mexico (GoM). Both non-selective and selective deposit feeders were the most frequent feeding guilds, as expected, but their abundances were significantly lower. An increase in the number of carnivorous Sigalionidae may be a response to an accumulation of petroleum hydrocarbons on the sediment. The concentration of oil in the sediments was low and the source of the oil remains equivocal. Multivariate analyses illustrated the differences between communities near the DWH and those from prior studies in similar deep GoM habitats. In summary, Deep Water Horizon Oil Spill appears to have had a measurable impact on the polychaetes.

  15. The relationship between terminal QRS distortion on initial ECG and final infarct size at 4 months in conventional ST- segment elevation myocardial infarct patients

    NARCIS (Netherlands)

    Hassell, M. E. C. J.; Delewi, R.; Lexis, C. P. H.; Smulders, M.W.; Hirsch, A.; Wagner, G.; Bekkers, S. C. A. M.; van der Horst, I. C. C.; Zijlstra, F.; van Rossum, A.C.; Piek, J.J.; van der Harst, P.; Nijveldt, R.

    2016-01-01

    Background: In the Sclarovsky-Birnbaum Ischemia Severity Grading System for patients with ST-segment elevation myocardial infarction (STEMI), "Terminal QRS distortion" is considered as "Grade III". This evidence for most severe ischemia is associated with cardiovascular magnetic resonance imaging

  16. Segmental Neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Yesudian Devakar

    1997-01-01

    Full Text Available Segmental neurofibromatosis is a rare variant of neurofibromatosis in which the lesions are confined to one segment or dermatome of the body. They resemble classical neurofibromas in their morphology, histopathology and electron microscopy. However, systemic associations are usually absent. We report one such case with these classical features.

  17. TU-A-9A-06: Semi-Automatic Segmentation of Skin Cancer in High-Frequency Ultrasound Images: Initial Comparison with Histology

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Y [Univ. Alabama at Birmingham, Birmingham, AL (United States); Li, X [Medical College of Wisconsin, Milwaukee, WI (United States); Fishman, K [Sensus Healthcare, Boca Raton, FL (United States); Yang, X [Department of Radiation Oncology and Winship Cancer Institute, Emory Univ., Atlanta, GA (United States); Liu, T [Emory Univ, Atlanta, GA (United States)

    2014-06-15

    Purpose: In skin-cancer radiotherapy, the assessment of skin lesion is challenging, particularly with important features such as the depth and width hard to determine. The aim of this study is to develop interative segmentation method to delineate tumor boundary using high-frequency ultrasound images and to correlate the segmentation results with the histopathological tumor dimensions. Methods: We analyzed 6 patients who comprised a total of 10 skin lesions involving the face, scalp, and hand. The patient’s various skin lesions were scanned using a high-frequency ultrasound system (Episcan, LONGPORT, INC., PA, U.S.A), with a 30-MHz single-element transducer. The lateral resolution was 14.6 micron and the axial resolution was 3.85 micron for the ultrasound image. Semiautomatic image segmentation was performed to extract the cancer region, using a robust statistics driven active contour algorithm. The corresponding histology images were also obtained after tumor resection and served as the reference standards in this study. Results: Eight out of the 10 lesions are successfully segmented. The ultrasound tumor delineation correlates well with the histology assessment, in all the measurements such as depth, size, and shape. The depths measured by the ultrasound have an average of 9.3% difference comparing with that in the histology images. The remaining 2 cases suffered from the situation of mismatching between pathology and ultrasound images. Conclusion: High-frequency ultrasound is a noninvasive, accurate and easy-accessible modality to image skin cancer. Our segmentation method, combined with high-frequency ultrasound technology, provides a promising tool to estimate the extent of the tumor to guide the radiotherapy procedure and monitor treatment response.

  18. Image segmentation by graph partitioning

    Science.gov (United States)

    Torres, Ana Sofia; Monteiro, Fernando C.

    2012-09-01

    In this paper we propose an hybrid method for the image segmentation which combines the edge-based, region-based and the morphological techniques in conjunction through the spectral based clustering approach. An initial partitioning of the image into atomic regions is set by applying a watershed method to the image gradient magnitude. This initial partition is the input to a computationally efficient region segmentation process which produces the final segmentation. We have applied our approach on several images of the Berkeley Segmentation Dataset. The results reveal the accuracy of the propose method.

  19. Segmental Vitiligo.

    Science.gov (United States)

    van Geel, Nanja; Speeckaert, Reinhart

    2017-04-01

    Segmental vitiligo is characterized by its early onset, rapid stabilization, and unilateral distribution. Recent evidence suggests that segmental and nonsegmental vitiligo could represent variants of the same disease spectrum. Observational studies with respect to its distribution pattern point to a possible role of cutaneous mosaicism, whereas the original stated dermatomal distribution seems to be a misnomer. Although the exact pathogenic mechanism behind the melanocyte destruction is still unknown, increasing evidence has been published on the autoimmune/inflammatory theory of segmental vitiligo. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Distal Rectal Skip-Segment Hirschsprung Disease and the Potential for False-Negative Diagnosis.

    Science.gov (United States)

    Coe, Alexander; Avansino, Jeffrey R; Kapur, Raj P

    2016-01-01

    In skip-segment Hirschsprung disease (SS-HSCR), an aganglionic segment of bowel, which extends proximally from the distal rectum, is interrupted by a ganglionated "skip segment." Skip segments are usually located far proximal to the rectum where they do not interfere with initial diagnosis, although the possibility of distal SS-HSCR should be considered during interpretation of intraoperative biopsies or patients with atypical postoperative courses. We report 2 cases of SS-HSCR with skip areas in the distal rectum, 1 of which led to a false-negative diagnosis by suction rectal biopsy. These 2 cases of SS-HSCR, along with others in the literature, highlight the point that ganglionic skip segments can confuse clinicians and lead to inadequate bowel resection, diagnostic delay, or a false-negative diagnosis. The pathogenesis of SS-HSCR is discussed in light of recent discoveries regarding transmesenteric migration of vagal neural crest cells and the role of sacral neural crest cells in hindgut neurodevelopment.

  1. Nanofiber-segment ring resonator

    CERN Document Server

    Jones, D E; Franson, J D; Pittman, T B

    2016-01-01

    We describe a fiber ring resonator comprised of a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact with atoms in close proximity to the nanofiber surface. We report on an experiment using a warm atomic vapor and low-finesse cavity, and briefly discuss the potential for reaching the strong coupling regime of cavity QED by using trapped atoms and a high-finesse cavity of this kind.

  2. In vivo semi-automatic segmentation of multicontrast cardiovascular magnetic resonance for prospective cohort studies on plaque tissue composition: initial experience.

    Science.gov (United States)

    Yoneyama, Taku; Sun, Jie; Hippe, Daniel S; Balu, Niranjan; Xu, Dongxiang; Kerwin, William S; Hatsukami, Thomas S; Yuan, Chun

    2016-01-01

    Automatic in vivo segmentation of multicontrast (multisequence) carotid magnetic resonance for plaque composition has been proposed as a substitute for manual review to save time and reduce inter-reader variability in large-scale or multicenter studies. Using serial images from a prospective longitudinal study, we sought to compare a semi-automatic approach versus expert human reading in analyzing carotid atherosclerosis progression. Baseline and 6-month follow-up multicontrast carotid images from 59 asymptomatic subjects with 16-79 % carotid stenosis were reviewed by both trained radiologists with 2-4 years of specialized experience in carotid plaque characterization with MRI and a previously reported automatic atherosclerotic plaque segmentation algorithm, referred to as morphology-enhanced probabilistic plaque segmentation (MEPPS). Agreement on measurements from individual time points, as well as on compositional changes, was assessed using the intraclass correlation coefficient (ICC). There was good agreement between manual and MEPPS reviews on individual time points for calcification (CA) (area: ICC; 0.85-0.91; volume: ICC; 0.92-0.95) and lipid-rich necrotic core (LRNC) (area: ICC; 0.78-0.82; volume: ICC; 0.84-0.86). For compositional changes, agreement was good for CA volume change (ICC; 0.78) and moderate for LRNC volume change (ICC; 0.49). Factors associated with LRNC progression as detected by MEPPS review included intraplaque hemorrhage (positive association) and reduction in low-density lipoprotein cholesterol (negative association), which were consistent with previous findings from manual review. Automatic classifier for plaque composition produced results similar to expert manual review in a prospective serial MRI study of carotid atherosclerosis progression. Such automatic classification tools may be beneficial in large-scale multicenter studies by reducing image analysis time and avoiding bias between human reviewers.

  3. Region segmentation along image sequence

    Energy Technology Data Exchange (ETDEWEB)

    Monchal, L.; Aubry, P.

    1995-12-31

    A method to extract regions in sequence of images is proposed. Regions are not matched from one image to the following one. The result of a region segmentation is used as an initialization to segment the following and image to track the region along the sequence. The image sequence is exploited as a spatio-temporal event. (authors). 12 refs., 8 figs.

  4. The developmental spectrum of proximal radioulnar synostosis

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Alison M. [University of Manitoba, Winnipeg Regional Health Association Program of Genetics and Metabolism, Winnipeg, MB (Canada); University of Manitoba, Department of Paediatrics and Child Health, Winnipeg, MB (Canada); University of Manitoba, Department of Biochemistry and Medical Genetics, Winnipeg, MB (Canada); University of Manitoba, WRHA Program of Genetics and Metabolism, Departments of Paediatrics and Child Health, Biochemistry and Medical Genetics, Winnipeg, MB (Canada); Kibria, Lisa [University of Manitoba, Department of School of Medical Rehabilitation, Winnipeg, MB (Canada); Reed, Martin H. [University of Manitoba, Department of Paediatrics and Child Health, Winnipeg, MB (Canada); University of Manitoba, Department of Biochemistry and Medical Genetics, Winnipeg, MB (Canada); University of Manitoba, Department of Diagnostic Imaging, Winnipeg, MB (Canada)

    2010-01-15

    Proximal radioulnar synostosis is a rare upper limb malformation. The elbow is first identifiable at 35 days (after conception), at which stage the cartilaginous anlagen of the humerus, radius and ulna are continuous. Subsequently, longitudinal segmentation produces separation of the distal radius and ulna. However, temporarily, the proximal ends are united and continue to share a common perichondrium. We investigated the hypothesis that posterior congenital dislocation of the radial head and proximal radioulnar fusion are different clinical manifestations of the same primary developmental abnormality. Records were searched for ''proximal radioulnar fusion/posterior radial head dislocation'' in patients followed at the local Children's Hospital and Rehabilitation Centre for Children. Relevant radiographic, demographic and clinical data were recorded. Ethics approval was obtained through the University Research Ethics Board. In total, 28 patients met the inclusion criteria. The majority of patients (16) had bilateral involvement; eight with posterior dislocation of the radial head only; five had posterior radial head dislocation with radioulnar fusion and two had radioulnar fusion without dislocation. One patient had bilateral proximal radioulnar fusion and posterior dislocation of the left radial head. Nine patients had only left-sided involvement, and three had only right-sided involvement.The degree of proximal fusion varied, with some patients showing 'complete' proximal fusion and others showing fusion that occurred slightly distal to the radial head: 'partially separated.' Associated disorders in our cohort included Poland syndrome (two patients), Cornelia de Lange syndrome, chromosome anomalies (including tetrasomy X) and Cenani Lenz syndactyly. The suggestion of a developmental relationship between posterior dislocation of the radial head and proximal radioulnar fusion is supported by the fact that both anomalies

  5. Capacitive proximity sensor

    Science.gov (United States)

    Kronberg, James W.

    1994-01-01

    A proximity sensor based on a closed field circuit. The circuit comprises a ring oscillator using a symmetrical array of plates that creates an oscillating displacement current. The displacement current varies as a function of the proximity of objects to the plate array. Preferably the plates are in the form of a group of three pair of symmetric plates having a common center, arranged in a hexagonal pattern with opposing plates linked as a pair. The sensor produces logic level pulses suitable for interfacing with a computer or process controller. The proximity sensor can be incorporated into a load cell, a differential pressure gauge, or a device for measuring the consistency of a characteristic of a material where a variation in the consistency causes the dielectric constant of the material to change.

  6. Neighborhoods and manageable proximity

    Directory of Open Access Journals (Sweden)

    Stavros Stavrides

    2011-08-01

    Full Text Available The theatricality of urban encounters is above all a theatricality of distances which allow for the encounter. The absolute “strangeness” of the crowd (Simmel 1997: 74 expressed, in its purest form, in the absolute proximity of a crowded subway train, does not generally allow for any movements of approach, but only for nervous hostile reactions and submissive hypnotic gestures. Neither forced intersections in the course of pedestrians or vehicles, nor the instantaneous crossing of distances by the technology of live broadcasting and remote control give birth to places of encounter. In the forced proximity of the metropolitan crowd which haunted the city of the 19th and 20th century, as well as in the forced proximity of the tele-presence which haunts the dystopic prospect of the future “omnipolis” (Virilio 1997: 74, the necessary distance, which is the stage of an encounter between different instances of otherness, is dissipated.

  7. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... a basic understanding of grouping people. Advertising agencies may use segmentation totarget advertisements, while food companies may usesegmentation to develop products to various groups of consumers. MAPP has for example investigated the positioning of fish in relation to other food products....... The traditionalists are characterised by favouring pork, poultry and beef. Since it is difficult to change consumers' tastes, the short-term consequence may be to focus on the "fish lovers" and target the communication towards these consumers. In the long run, "traditionalists" may be persuaded to revise...

  8. Atrofia muscular proximal familiar

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1962-09-01

    Full Text Available Os autores relatam dois casos de atrofia muscular proximal familiar, moléstia caracterizada por déficit motor e atrofias musculares de distribuição proximal, secundárias a lesão de neurônios periféricos. Assim, como em outros casos descritos na literatura, foi feito inicialmente o diagnóstico de distrofia muscular progressiva. O diagnóstico correto foi conseguido com auxílio da eletromiografia e da biopsia muscular.

  9. The clinical utility of reduced-distortion readout-segmented echo-planar imaging in the head and neck region: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Koyasu, Sho; Iima, Mami; Umeoka, Shigeaki; Morisawa, Nobuko; Togashi, Kaori [Kyoto University, Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Sakyo-Ku, Kyoto (Japan); Porter, David A. [Siemens AG, MED MR PLM AW Neurology, Allee am Roethelheimpark 2, Erlangen (Germany); Ito, Juichi [Kyoto University, Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Sakyo-Ku, Kyoto (Japan); Le Bihan, Denis [Kyoto University, Human Brain Research Center, Graduate School of Medicine, Sakyo-Ku, Kyoto (Japan); Neurospin, CEA-Saclay Center, Gif-sur-Yvette Cedex (France)

    2014-12-15

    To evaluate whether readout-segmented echo-planar imaging (RS-EPI) diffusion weighted image (DWI) can diminish image distortion in the head and neck area, compared with single-shot (SS)-EPI DWI. We conducted phantom and patient studies using 3 T magnetic resonance imaging (MRI) with a 16-channel coil. For the phantom study, we evaluated distortion and signal homogeneity in gel phantoms. For the patient study, 29 consecutive patients with clinically suspicious parotid lesions were prospectively enrolled. RS-EPI and SS-EPI DWI were evaluated by two independent readers for identification of organ/lesion and distortion, using semiquantitative scales and quantitative scores. Apparent diffusion coefficient (ADC) values and contrast-noise ratios of parotid tumours (if present; n = 15) were also compared. The phantom experiments showed that RS-EPI provided less distorted and more homogeneous ADC maps than SS-EPI. In the patient study, RS-EPI was found to provide significantly less distortion in almost all organs/lesions (p < 0.05), according to both semiquantitative scales and quantitative scores. There was no significant difference in ADC values and contrast-noise ratios between the two DWI techniques. The distortion in DWI was significantly reduced with RS-EPI in both phantom and patient studies. The RS-EPI technique provided more homogenous images than SS-EPI, and can potentially offer higher image quality in the head and neck area. (orig.)

  10. The impact of initial and residual thrombus burden on the no-reflow phenomenon in patients with ST-segment elevation myocardial infarction.

    Science.gov (United States)

    Ahn, Sung Gyun; Choi, Hyun-Hee; Lee, Ji Hyun; Lee, Jun-Won; Youn, Young Jin; Yoo, Sang-Yong; Cho, Byung Ryul; Lee, Seung-Hwan; Yoon, Junghan

    2015-05-01

    Limited data are available on the clinical significance of residual thrombi after thrombectomy and prestenting reduced epicardial coronary flow in ST-segment elevation myocardial infarct (STEMI) patients. The incidence of the no-reflow phenomenon, defined as a final thrombolysis in myocardial infarction (TIMI) flow grade of up to 2 or a myocardial blush grade of up to 1, was compared in 260 STEMI patients undergoing primary percutaneous coronary intervention according to thrombotic burden. Large thrombotic burden (LTB), defined as a thrombus score of at least 3, was observed in 134 patients, among whom 66 (49.3%) underwent aspiration thrombectomy. No-reflow incidence was compared on the basis of thrombectomy treatment, thrombus residue after thrombectomy, and prestenting TIMI flow grade. The no-reflow phenomenon occurred most frequently in LTB patients without thrombectomy, followed by those who underwent thrombectomy and the small thrombus burden group (33.8 vs. 21.2 vs. 10.3%, respectively, Pthrombi and decreased coronary flow were related to a higher occurrence of the no-reflow phenomenon.

  11. [Experimental proximal carpectomy. Biodynamics].

    Science.gov (United States)

    Kuhlmann, J N

    1992-01-01

    Proximal carpectomy was performed in 10 fresh cadavre wrists. Dynamic x-rays were taken and the forces necessary to obtain different movements before and after the operation were measured. Comparison of these parameters clearly defines the advantages and limitations of carpectomy and indicates the reasons.

  12. Proximate Analysis of Coal

    Science.gov (United States)

    Donahue, Craig J.; Rais, Elizabeth A.

    2009-01-01

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,…

  13. Proximal Tibial Bone Graft

    Science.gov (United States)

    ... the Big Toe Ailments of the Smaller Toes Diabetic Foot Treatments Currently selected Injections and other Procedures Treatments ... from which the bone was taken if the foot/ankle surgeries done at the same time allow for it. ... problems after a PTBG include infection, fracture of the proximal tibia and pain related ...

  14. Simultaneous Reconstruction and Segmentation of CT Scans with Shadowed Data

    DEFF Research Database (Denmark)

    Lauze, Francois Bernard; Quéau, Yvain; Plenge, Esben

    2017-01-01

    We propose a variational approach for simultaneous recon- struction and multiclass segmentation of X-ray CT images, with limited field of view and missing data. We propose a simple energy minimi- sation approach, loosely based on a Bayesian rationale. The resulting non convex problem is solved by...... by alternating reconstruction steps using an iterated relaxed proximal gradient, and a proximal approach for the segmentation. Preliminary results on synthetic data demonstrate the po- tential of the approach for synchrotron imaging applications....

  15. Automatic Segmentation of Spanish Speech Into Syllables

    OpenAIRE

    Mariño Acebal, José Bernardo

    1989-01-01

    This paper presents an algorithm that provides a syllabic segmentation of speech following the syllabification rules of Spanish language. The implemented algorithm is divided into two parts. First, an initial segmentation is made based on energy contour, sonority and duration. Second, a fine adjustement of syllable boundaries and final segmentation is made by applying syllabic rules. Peer Reviewed

  16. Proximal femoral fractures

    DEFF Research Database (Denmark)

    Palm, Henrik; Teixidor, Jordi

    2015-01-01

    -displaced femoral neck fractures and prosthesis for displaced among the elderly; and sliding hip screw for stabile- and intramedullary nails for unstable- and sub-trochanteric fractures) but they are based on a variety of criteria and definitions - and often leave wide space for the individual surgeons' subjective...... guidelines for hip fracture surgery and discuss a method for future pathway/guideline implementation and evaluation. METHODS: By a PubMed search in March 2015 six studies of surgical treatment pathways covering all types of proximal femoral fractures with publication after 1995 were identified. Also we...... searched the homepages of the national heath authorities and national orthopedic societies in West Europe and found 11 national or regional (in case of no national) guidelines including any type of proximal femoral fracture surgery. RESULTS: Pathway consensus is outspread (internal fixation for un...

  17. Proximal humeral fractures

    OpenAIRE

    Mauro, Craig S.

    2011-01-01

    Proximal humeral fractures may present with many different configurations in patients with varying co-morbities and expectations. As a result, the treating physician must understand the fracture pattern, the quality of the bone, other patient-related factors, and the expanding range of reconstructive options to achieve the best functional outcome and to minimize complications. Current treatment options range from non-operative treatment with physical therapy to fracture fixation using percuta...

  18. Mixed segmentation

    DEFF Research Database (Denmark)

    Bonde, Anders; Aagaard, Morten; Hansen, Allan Grutt

    content analysis and audience segmentation in a single-source perspective. The aim is to explain and understand target groups in relation to, on the one hand, emotional response to commercials or other forms of audio-visual communication and, on the other hand, living preferences and personality traits....... Innovatively, the research process is documented via an interactive data-visualization tool by which readers and fellow peers can access and, by using various filtering options, further analyze the results and, ultimately, reformulate the problem field....

  19. [Segmental neurofibromatosis].

    Science.gov (United States)

    Wagner, G; Meyer, V; Sachse, M M

    2017-11-08

    Thirteen years ago, a 48-year-old man developed numerous neurofibromas in a circumscribed area on the right chest. At the same time, a bilateral seminoma was diagnosed and treated curatively. There was no evidence for other complications of neurofibromatosis. The family history was inconspicuous. The segmental neurofibromatosis (SN) presented in this patient is the result of a mosaic formation resulting from a mutation of the NF1 gene, a tumor suppressor gene. Concomitant, typical diseases of neurofibromatosis generalisata (NFG), including malignant neoplasms, are the exception to SN.

  20. Segmental neurofibromatosis.

    Science.gov (United States)

    Sobjanek, Michał; Dobosz-Kawałko, Magdalena; Michajłowski, Igor; Pęksa, Rafał; Nowicki, Roman

    2014-12-01

    Segmental neurofibromatosis or type V neurofibromatosis is a rare genodermatosis characterized by neurofibromas, café-au-lait spots and neurofibromas limited to a circumscribed body region. The disease may be associated with systemic involvement and malignancies. The disorder has not been reported yet in the Polish medical literature. A 63-year-old Caucasian woman presented with a 20-year history of multiple, flesh colored, dome-shaped, soft to firm nodules situated in the right lumbar region. A histopathologic evaluation of three excised tumors revealed neurofibromas. No neurological and ophthalmologic symptoms of neurofibromatosis were diagnosed.

  1. Live Imaging of Kv7.2/7.3 Cell Surface Dynamics at the Axon Initial Segment: High Steady-State Stability and Calpain-Dependent Excitotoxic Downregulation Revealed

    DEFF Research Database (Denmark)

    Benned-Jensen, Tau; Christensen, Rasmus Kordt; Denti, Federico

    2016-01-01

    live imaging. We discovered that they are extraordinarily stable and exhibit a very low surface mobility both during steady state and neuronal stimulation. In the latter case, we also found that neither localization nor cell surface numbers were changed. However, at high glutamate loads, we observed......The voltage-gated K(+) channels Kv7.2 and Kv7.3 are located at the axon initial segment (AIS) and exert strong control over action potential generation. Therefore, changes in their localization or cell surface numbers are likely to influence neuronal signaling. However, nothing is known about...... the cell surface dynamics of Kv7.2/7.3 at steady state or during short-term neuronal stimulation. This is primarily attributable to their membrane topology, which hampers extracellular epitope tagging. Here we circumvent this limitation by fusing an extra phluorin-tagged helix to the N terminus of human Kv...

  2. Improving image segmentation by learning region affinities

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  3. Palliation of proximal malignant biliary obstruction by endoscopic endoprosthesis insertion.

    Science.gov (United States)

    Polydorou, A A; Cairns, S R; Dowsett, J F; Hatfield, A R; Salmon, P R; Cotton, P B; Russell, R C

    1991-01-01

    For four years up to December 1987, 190 patients (median age 73 years) with proximal malignant biliary obstruction were treated by endoscopic endoprosthesis insertion. Altogether 101 had cholangiocarcinoma, 21 gall bladder carcinoma, 20 local spread of pancreatic carcinoma, and 48 metastatic malignancy. Fifty eight patients had type I, 54 type II, and 78 type III proximal biliary strictures (Bismuth classification). All patients were either unfit or unsuitable for an attempt at curative surgical resection. A single endoprosthesis was placed initially, with a further stent being placed only if relief of cholestasis was insufficient or sepsis developed in undrained segments. The combined percutaneous-endoscopic technique was used to place the endoprosthesis when appropriate, after failed endoscopic endoprosthesis insertion or for second endoprosthesis placement. Full follow up was available in 97%.Thirteen patients were still alive at the time of review and all but one had been treated within the past six months. Initial endoprosthesis insertion succeeded technically at the first attempt in 127 patients, at the second in 30, and at a combined procedure in a further 13 (cumulative total success rate 89% - type I: 93%; type II: 94%; and type III: 84%). There was adequate biliary drainage after single endoprosthesis insertion in 152 of the 170 successful placements, giving an overall successful drainage rate of 80%. Three patients had a second stent placed by combined procedure because of insufficient drainage, giving an overall successful drainage rate of 82% (155 of 190). The final overall drainage success rates were type I: 91%; type II: 83%; and type III: 73%. The early complication rates were type I: 7%; type II: 14%; and type III: 31%. The principle early complication was clinical cholangitis, which occurred in 13 patients (7%) and required second stent placement in five. The 30 day mortality was 22% overall (type I: 14%; type II: 15%; and type III: 32%) but the

  4. Study on segmented distribution for reliability evaluation

    Directory of Open Access Journals (Sweden)

    Huaiyuan Li

    2017-02-01

    Full Text Available In practice, the failure rate of most equipment exhibits different tendencies at different stages and even its failure rate curve behaves a multimodal trace during its life cycle. As a result, traditionally evaluating the reliability of equipment with a single model may lead to severer errors. However, if lifetime is divided into several different intervals according to the characteristics of its failure rate, piecewise fitting can more accurately approximate the failure rate of equipment. Therefore, in this paper, failure rate is regarded as a piecewise function, and two kinds of segmented distribution are put forward to evaluate reliability. In order to estimate parameters in the segmented reliability function, Bayesian estimation and maximum likelihood estimation (MLE of the segmented distribution are discussed in this paper. Since traditional information criterion is not suitable for the segmented distribution, an improved information criterion is proposed to test and evaluate the segmented reliability model in this paper. After a great deal of testing and verification, the segmented reliability model and its estimation methods presented in this paper are proven more efficient and accurate than the traditional non-segmented single model, especially when the change of the failure rate is time-phased or multimodal. The significant performance of the segmented reliability model in evaluating reliability of proximity sensors of leading-edge flap in civil aircraft indicates that the segmented distribution and its estimation method in this paper could be useful and accurate.

  5. Spectral clustering algorithms for ultrasound image segmentation.

    Science.gov (United States)

    Archip, Neculai; Rohling, Robert; Cooperberg, Peter; Tahmasebpour, Hamid; Warfield, Simon K

    2005-01-01

    Image segmentation algorithms derived from spectral clustering analysis rely on the eigenvectors of the Laplacian of a weighted graph obtained from the image. The NCut criterion was previously used for image segmentation in supervised manner. We derive a new strategy for unsupervised image segmentation. This article describes an initial investigation to determine the suitability of such segmentation techniques for ultrasound images. The extension of the NCut technique to the unsupervised clustering is first described. The novel segmentation algorithm is then performed on simulated ultrasound images. Tests are also performed on abdominal and fetal images with the segmentation results compared to manual segmentation. Comparisons with the classical NCut algorithm are also presented. Finally, segmentation results on other types of medical images are shown.

  6. Segmentation-based MR attenuation correction including bones also affects quantitation in brain studies: an initial result of 18F-FP-CIT PET/MR for patients with parkinsonism.

    Science.gov (United States)

    Choi, Hongyoon; Cheon, Gi Jeong; Kim, Han-Joon; Choi, Seung Hong; Lee, Jae Sung; Kim, Yong-Il; Kang, Keon Wook; Chung, June-Key; Kim, E Edmund; Lee, Dong Soo

    2014-10-01

    Attenuation correction (AC) with an ultrashort echo time (UTE) sequence has recently been used in combination with segmentation for cortical bone identification for brain PET/MR studies. The purpose of this study was to evaluate the quantification of (18)F-fluoropropyl-carbomethoxyiodophenylnortropane ((18)F-FP-CIT) binding in brain PET/MR, particularly focusing on effects of UTE-based AC including bone segmentation. Sixteen patients with initially suspected parkinsonism were prospectively enrolled. An emission scan was acquired 110 min after (18)F-FP-CIT injection on a dedicated PET/MR scanner, immediately followed by another emission scan using a PET/CT scanner 120 min after the injection. A UTE-based attenuation map was used to classify the voxels into 3 tissues: bone, soft tissue, and air. All PET images were spatially normalized, and a specific-to-nonspecific dopamine transporter (DAT) binding ratio (BR) was calculated using statistical probabilistic anatomic mapping. The level of agreement was assessed with intraclass correlation coefficients (ICCs). Voxelwise comparison between PET images acquired from PET/MR and PET/CT was performed. We compared non-attenuation-corrected images to analyze UTE-based AC effects on DAT quantification. BR in the putamen obtained from PET/MR and PET/CT showed low interequipment variability, whereas BR in the caudate nucleus showed significant variability (ICC = 0.967 and 0.682 for putamen and caudate nucleus, respectively). BR in the caudate nucleus was significantly underestimated by PET/MR, compared with PET/CT (mean difference of BR = 0.66, P PET/MR showed significantly low BR in the periventricular regions, which was caused by a misclassification of the ventricle as air on the attenuation map. We also compared non-AC images, revealing low interequipment variability even in the caudate nucleus (ICC = 0.937 and 0.832 for putamen and caudate nucleus, respectively). Our data demonstrate spatial bias of the DAT BR on (18)F

  7. Image Segmentation Algorithms Overview

    OpenAIRE

    Yuheng, Song; Hao, Yan

    2017-01-01

    The technology of image segmentation is widely used in medical image processing, face recognition pedestrian detection, etc. The current image segmentation techniques include region-based segmentation, edge detection segmentation, segmentation based on clustering, segmentation based on weakly-supervised learning in CNN, etc. This paper analyzes and summarizes these algorithms of image segmentation, and compares the advantages and disadvantages of different algorithms. Finally, we make a predi...

  8. Semiconductor detectors with proximity signal readout

    Energy Technology Data Exchange (ETDEWEB)

    Asztalos, Stephen J. [XIA, LLC, Hayward, CA (United States)

    2014-01-30

    Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.

  9. PROXIMITY MANAGEMENT IN CRISIS CONDITIONS

    Directory of Open Access Journals (Sweden)

    Ion Dorin BUMBENECI

    2010-01-01

    Full Text Available The purpose of this study is to evaluate the level of assimilation for the terms "Proximity Management" and "Proximity Manager", both in the specialized literature and in practice. The study has two parts: the theoretical research of the two terms, and an evaluation of the use of Proximity management in 32 companies in Gorj, Romania. The object of the evaluation resides in 27 companies with less than 50 employees and 5 companies with more than 50 employees.

  10. Plasticity of the Axon Initial Segment

    DEFF Research Database (Denmark)

    Petersen, Anders Victor; Cotel, Florence; Perrier, Jean François

    2017-01-01

    of metabotropic receptors modulates the properties of ion channels expressed at the AIS within seconds and consequently produces fast adjustments of neuronal excitability. Recent results suggest that this plasticity plays important roles in physiological functions as diverse as memory formation, hearing...

  11. Protein biomarker validation via proximity ligation assays.

    Science.gov (United States)

    Blokzijl, A; Nong, R; Darmanis, S; Hertz, E; Landegren, U; Kamali-Moghaddam, M

    2014-05-01

    The ability to detect minute amounts of specific proteins or protein modifications in blood as biomarkers for a plethora of human pathological conditions holds great promise for future medicine. Despite a large number of plausible candidate protein biomarkers published annually, the translation to clinical use is impeded by factors such as the required size of the initial studies, and limitations of the technologies used. The proximity ligation assay (PLA) is a versatile molecular tool that has the potential to address some obstacles, both in validation of biomarkers previously discovered using other techniques, and for future routine clinical diagnostic needs. The enhanced specificity of PLA extends the opportunities for large-scale, high-performance analyses of proteins. Besides advantages in the form of minimal sample consumption and an extended dynamic range, the PLA technique allows flexible assay reconfiguration. The technology can be adapted for detecting protein complexes, proximity between proteins in extracellular vesicles or in circulating tumor cells, and to address multiple post-translational modifications in the same protein molecule. We discuss herein requirements for biomarker validation, and how PLA may play an increasing role in this regard. We describe some recent developments of the technology, including proximity extension assays, the use of recombinant affinity reagents suitable for use in proximity assays, and the potential for single cell proteomics. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. © 2013.

  12. A case of acute polyneuropathy with nephrotic syndrome showing transient proximal sensory conduction defects.

    Science.gov (United States)

    Oh, Jeeyoung; Kim, Seung-Min; Sunwoo, Il Nam

    2012-03-01

    Acute sensorimotor polyneuropathy that resembles Guillain-Barré syndrome (GBS) is rarely accompanied with nephrotic syndrome, and its underlying immunological mechanisms are unclear. A 56-year-old man presented with simultaneous acute progressive symmetric sensorimotor polyneuropathy and proteinuria. A kidney biopsy revealed focal segmental glomerulosclerosis. Serial electrophysiologic studies showed only a transient proximal conduction block in the median nerve, stimulated somatosensory evoked potential and prolonged terminal latencies of the median and peroneal nerves. The patient's neurologic deficits and kidney dysfunction recovered with corticosteroid treatment. Our case showed that somatosensory evoked potential study can be an important objective tool in the diagnosis of acute polyneuropathy with normal distal nerve conduction and that corticosteroids should be considered in the initial treatment of GBS-resembling polyneuropathy associated with nephrotic syndrome.

  13. Strategic market segmentation

    National Research Council Canada - National Science Library

    Maricic, Branko; Djordjevic, Aleksandar

    2015-01-01

    ..., requires segmented approach to the market that appreciates differences in expectations and preferences of customers. One of significant activities in strategic planning of marketing activities is market segmentation...

  14. Effects of proximal and distal robot-assisted upper limb rehabilitation on chronic stroke recovery.

    Science.gov (United States)

    Mazzoleni, Stefano; Sale, Patrizio; Franceschini, Marco; Bigazzi, Samuele; Carrozza, Maria Chiara; Dario, Paolo; Posteraro, Federico

    2013-01-01

    To evaluate the effects of add-on distal upper limb robot-assisted treatment on the outcome of proximal regions. 64 chronic stroke patients divided into two groups participated in the study. Group A was assigned to the proximal robot-assisted rehabilitation, Group B to the proximal and distal. Shoulder/elbow subsection of Fugl-Meyer Assessment scale was collected for Group A, whereas for Group B wrist subsection was also collected. Motricity Index was used and a set of kinematic parameters was computed for both groups. A decrease in impairment after the treatment in both groups of patients (Group A: Shoulder/elbow FM p robot-assisted treatment in both groups; group B showed a greater improvement in velocity. Robotic treatment is effective to reduce motor impairment in chronic stroke patients even if distal training added to proximal segments in the Group B does not provide any incremental benefit to the proximal segments. It remains unclear if the effectiveness of robot-assisted treatment is directly related to the upper limb segment specifically treated and which order may lead to better outcome. Our study suggests that kinematic parameters should be computed in order to better clarify the role of distal training (wrist) on proximal segments (shoulder/elbow) as well.

  15. [Arthroscopic fracture management in proximal humeral fractures].

    Science.gov (United States)

    Lill, H; Katthagen, C; Jensen, G; Voigt, C

    2013-04-01

    Arthroscopy has become increasingly more established in the treatment of proximal humeral fractures. In addition to the known advantages of minimally invasive surgery fracture and implant positioning can be optimized and controlled arthroscopically and relevant intra-articular concomitant pathologies (e.g. biceps tendon complex and rotator cuff) can be diagnosed and treated. Arthroscopic techniques have proven to be advantageous in the treatment of various entities of greater tuberosity fractures, lesser tuberosity fractures (suture bridging technique) and subcapital humeral fractures (arthroscopic nailing). This article presents an overview on innovative arthroscopic modalities for treating proximal humeral fractures, describes the surgical techniques and the advantages compared to open procedures as well as initial clinical results.

  16. Bicarbonate secretion by rabbit proximal colon.

    Science.gov (United States)

    Sullivan, S K; Smith, P L

    1986-10-01

    Stripped segments of proximal colon (1-6 cm distal to the ampulla caecalis coli) were studied in vitro in Ussing chambers under short-circuit conditions using the pH-stat technique. With glucose and HCO3-CO2 present in the serosal bathing solution only, proximal colon alkalinizes the luminal bathing solution at a rate of 2.1 +/- 0.2 mu eq X h-1 X cm-2 (n = 36). With HCO3-CO2 present in the luminal bathing solution alone, proximal colon does not significantly acidify or alkalinize the serosal bathing solution. Addition of glucose (10 mM) to the luminal bathing solution abolished luminal alkalinization. Removal of HCO3 and CO2 from the serosal bathing solution or replacement of O2 with N2 also abolished luminal alkalinization. Acetazolamide (0.1 mM) added to both bathing solutions did not alter the rate of luminal alkalinization. Ion-replacement studies revealed that the alkalinization process was highly dependent on the presence of Na in the bathing solutions and much less dependent on the presence of Cl. Furthermore, ouabain (0.1 mM) significantly reduced luminal alkalinization. As in rabbit ileum, serosal epinephrine (0.1 mM) did not alter luminal alkalinization but increased serosal alkalinization by a Na-dependent mechanism. These results suggest that luminal alkalinization results from a Na-dependent, active transcellular HCO3 transport process and that a Na-dependent HCO3 absorptive process is activated by adrenergic stimuli.

  17. An atypical case of segmental spinal dysgenesis

    Energy Technology Data Exchange (ETDEWEB)

    Zana, Elodie; Chalard, Francois; Sebag, Guy [Hopital Robert Debre, Department of Paediatric Imaging, Paris (France); Mazda, Keyvan [Hopital Robert Debre, Department of Paediatric Orthopaedic Surgery, Paris (France)

    2005-09-01

    Spinal segmental dysgenesis is a complex closed dysraphism. The diagnostic criteria are: lumbar or thoracolumbar vertebral dysgenesis causing kyphosis, focal spinal cord narrowing without exiting roots, deformity of the lower limbs and paraplegia or paraparesis. We present a newborn who showed atypical features of bifocal spinal cord narrowing, without any vertebral abnormality at the proximal level. This seems to be a variant of this rare entity, whose early diagnosis is important, as surgical stabilisation of the spine is required. (orig.)

  18. Segmental tubular sodium reabsorption in type 1 diabetes

    DEFF Research Database (Denmark)

    Dieperink, H; Eshøj, O; Leyssac, P P

    1993-01-01

    Segmental tubular sodium reabsorption in Type 1 (insulin-dependent) diabetes was measured in 36 patients in a cross-sectional study including one group (n = 13) without significant albuminuria (UalbV 1), one group (n = 16) with albuminuria in the range from 30 to 300 mg 24 h-1......, and a group (n = 7) with nephropathy (UalbV > 300 mg 24 h-1). Lithium clearance was used to measure end proximal delivery. From end proximal delivery, 51Cr-EDTA clearance (GFR) and sodium clearance, segmental tubular reabsorption was calculated. For all patients, GFR was directly correlated with end proximal...... delivery (r = 0.62, p 1, the direct correlation between GFR and end proximal delivery was also significant (r = 0.77, p

  19. Segmentation of MRI Volume Data Based on Clustering Method

    Directory of Open Access Journals (Sweden)

    Ji Dongsheng

    2016-01-01

    Full Text Available Here we analyze the difficulties of segmentation without tag line of left ventricle MR images, and propose an algorithm for automatic segmentation of left ventricle (LV internal and external profiles. Herein, we propose an Incomplete K-means and Category Optimization (IKCO method. Initially, using Hough transformation to automatically locate initial contour of the LV, the algorithm uses a simple approach to complete data subsampling and initial center determination. Next, according to the clustering rules, the proposed algorithm finishes MR image segmentation. Finally, the algorithm uses a category optimization method to improve segmentation results. Experiments show that the algorithm provides good segmentation results.

  20. Mucosal integrity and sensitivity to acid in the proximal esophagus in patients with gastroesophageal reflux disease.

    Science.gov (United States)

    van Hoeij, Froukje B; Weijenborg, Pim W; van den Bergh Weerman, Marius A; van den Wijngaard, René M J G J; Verheij, J; Smout, André J P M; Bredenoord, Albert J

    2016-07-01

    Acid reflux episodes that extend to the proximal esophagus are more likely to be perceived. This suggests that the proximal esophagus is more sensitive to acid than the distal esophagus, which could be caused by impaired mucosal integrity in the proximal esophagus. Our aim was to explore sensitivity to acid and mucosal integrity in different segments of the esophagus. We used a prospective observational study, including 12 patients with gastroesophageal reflux disease (GERD). After stopping acid secretion-inhibiting medication, two procedures were performed: an acid perfusion test and an upper endoscopy with electrical tissue impedance spectroscopy and esophageal biopsies. Proximal and distal sensitivity to acid and tissue impedance were measured in vivo, and mucosal permeability and epithelial intercellular spaces at different esophageal levels were measured in vitro. Mean lag time to heartburn perception was much shorter after proximal acid perfusion (0.8 min) than after distal acid perfusion (3.9 min) (P = 0.02). Median in vivo tissue impedance was significantly lower in the distal esophagus (4,563 Ω·m) compared with the proximal esophagus (8,170 Ω·m) (P = 0.002). Transepithelial permeability, as measured by the median fluorescein flux was significantly higher in the distal (2,051 nmol·cm(-2)·h(-1)) than in the proximal segment (368 nmol·cm(-2)·h(-1)) (P = 0.033). Intercellular space ratio and maximum heartburn intensity were not significantly different between the proximal and distal esophagus. In GERD patients off acid secretion-inhibiting medication, acid exposure in the proximal segment of the esophagus provokes symptoms earlier than acid exposure in the distal esophagus, whereas mucosal integrity is impaired more in the distal esophagus. These findings indicate that the enhanced sensitivity to proximal reflux episodes is not explained by increased mucosal permeability. Copyright © 2016 the American Physiological Society.

  1. Proximal collagenous gastroenteritides:

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Riis, Lene Buhl; Danese, Silvio

    2014-01-01

    a systematic review of collagenous gastritis, collagenous sprue, and a combination thereof. METHOD: The search yielded 117 studies which were suitable for inclusion in the systematic review. Excluding repeated cases, 89 case reports and 28 case series were reported, whereas no prospective studies...... of these disorders is presented. The prognosis of both collagenous gastritis and sprue seems not to be as dismal as considered previously. Data point to involvement of immune or autoimmune mechanisms potentially driven by luminal antigens initiating the fibroinflammatory condition. CONCLUSIONS: To reach...

  2. Fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig

    2013-01-01

    . The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles......, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis......Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate...

  3. The infrastructure of psychological proximity

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2015-01-01

    ). The experience of psychological proximity between patient and nurse is provided through confidence, continuity and the practical set-up. This constitutes an important enactment of skillfulness, which may render telemedicine a convincing health service in the future. Methodology: The study draws on a pilot...... (Langstrup & Winthereik 2008). This study contributes by showing the infrastructure of psychological proximity, which is provided by way of device, confidence, continuity and accountability....

  4. A Novel Iris Segmentation Scheme

    Directory of Open Access Journals (Sweden)

    Chen-Chung Liu

    2014-01-01

    Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

  5. GeoSegmenter: A statistically learned Chinese word segmenter for the geoscience domain

    Science.gov (United States)

    Huang, Lan; Du, Youfu; Chen, Gongyang

    2015-03-01

    Unlike English, the Chinese language has no space between words. Segmenting texts into words, known as the Chinese word segmentation (CWS) problem, thus becomes a fundamental issue for processing Chinese documents and the first step in many text mining applications, including information retrieval, machine translation and knowledge acquisition. However, for the geoscience subject domain, the CWS problem remains unsolved. Although a generic segmenter can be applied to process geoscience documents, they lack the domain specific knowledge and consequently their segmentation accuracy drops dramatically. This motivated us to develop a segmenter specifically for the geoscience subject domain: the GeoSegmenter. We first proposed a generic two-step framework for domain specific CWS. Following this framework, we built GeoSegmenter using conditional random fields, a principled statistical framework for sequence learning. Specifically, GeoSegmenter first identifies general terms by using a generic baseline segmenter. Then it recognises geoscience terms by learning and applying a model that can transform the initial segmentation into the goal segmentation. Empirical experimental results on geoscience documents and benchmark datasets showed that GeoSegmenter could effectively recognise both geoscience terms and general terms.

  6. Support for context effects on segmentation and segments depends on the context.

    Science.gov (United States)

    Heffner, Christopher C; Newman, Rochelle S; Idsardi, William J

    2017-04-01

    Listeners must adapt to differences in speech rate across talkers and situations. Speech rate adaptation effects are strong for adjacent syllables (i.e., proximal syllables). For studies that have assessed adaptation effects on speech rate information more than one syllable removed from a point of ambiguity in speech (i.e., distal syllables), the difference in strength between different types of ambiguity is stark. Studies of word segmentation have shown large shifts in perception as a result of distal rate manipulations, while studies of segmental perception have shown only weak, or even nonexistent, effects. However, no study has standardized methods and materials to study context effects for both types of ambiguity simultaneously. Here, a set of sentences was created that differed as minimally as possible except for whether the sentences were ambiguous to the voicing of a consonant or ambiguous to the location of a word boundary. The sentences were then rate-modified to slow down the distal context speech rate to various extents, dependent on three different definitions of distal context that were adapted from previous experiments, along with a manipulation of proximal context to assess whether proximal effects were comparable across ambiguity types. The results indicate that the definition of distal influenced the extent of distal rate effects strongly for both segments and segmentation. They also establish the presence of distal rate effects on word-final segments for the first time. These results were replicated, with some caveats regarding the perception of individual segments, in an Internet-based sample recruited from Mechanical Turk.

  7. Prediction of biases for optical proximity correction through partial coherent identification

    Science.gov (United States)

    Jeong, Moongyu; Hahn, Jae W.

    2016-01-01

    Most approaches to model-based optical proximity correction (OPC) use an iterative algorithm to determine the optimum mask. Each iteration requires at least one simulation, which is the most time-consuming part of model-based OPC. As the layout becomes more complicated and the process conditions are driven to the physical limit, the required number of iterations increases dramatically. To overcome this problem, we propose a method to predict the OPC bias of layout segments with a single-hidden-layer neural network. The segments are characterized by length and based on intensities at the corresponding control points, and these features are used as input to the network, which is trained with an extreme learning machine. We obtain a best-error root mean square of 1.29 nm from training and test experiments for layout clips sampled from a random contact layer of a logic device. In addition, we reduced the iterations by 27.0% by initializing the biases in the trained network before performing the main iterations of the OPC algorithm.

  8. Segmented trapped vortex cavity

    Science.gov (United States)

    Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

    2010-01-01

    An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

  9. Multi-segmental neurofibromatosis

    OpenAIRE

    Kumar Sudhir; Kumar Ravi

    2004-01-01

    Neurofibromatosis (NF), one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for l...

  10. Automatic Melody Segmentation

    NARCIS (Netherlands)

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation

  11. Cubesat Proximity Operations Demonstration (CPOD)

    Science.gov (United States)

    Villa, Marco; Martinez, Andres; Petro, Andrew

    2015-01-01

    The CubeSat Proximity Operations Demonstration (CPOD) project will demonstrate rendezvous, proximity operations and docking (RPOD) using two 3-unit (3U) CubeSats. Each CubeSat is a satellite with the dimensions 4 inches x 4 inches x 13 inches (10 centimeters x 10 centimeters x 33 centimeters) and weighing approximately 11 pounds (5 kilograms). This flight demonstration will validate and characterize many new miniature low-power proximity operations technologies applicable to future missions. This mission will advance the state of the art in nanosatellite attitude determination,navigation and control systems, in addition to demonstrating relative navigation capabilities.The two CPOD satellites are scheduled to be launched together to low-Earth orbit no earlier than Dec. 1, 2015.

  12. Efficient segmentation of skin epidermis in whole slide histopathological images.

    Science.gov (United States)

    Xu, Hongming; Mandal, Mrinal

    2015-01-01

    Segmentation of epidermis areas is an important step towards automatic analysis of skin histopathological images. This paper presents a robust technique for epidermis segmentation in whole slide skin histopathological images. The proposed technique first performs a coarse epidermis segmentation using global thresholding and shape analysis. The epidermis thickness is then estimated by a series of line segments perpendicular to the main axis of the initially segmented epidermis mask. If the segmented epidermis mask has a thickness greater than a predefined threshold, the segmentation is suspected to be inaccurate. A second pass of fine segmentation using k-means algorithm is then carried out over these coarsely segmented result to enhance the performance. Experimental results on 64 different skin histopathological images show that the proposed technique provides a superior performance compared to the existing techniques.

  13. A Hybrid Technique for Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    Alamgir Nyma

    2012-01-01

    Full Text Available Medical image segmentation is an essential and challenging aspect in computer-aided diagnosis and also in pattern recognition research. This paper proposes a hybrid method for magnetic resonance (MR image segmentation. We first remove impulsive noise inherent in MR images by utilizing a vector median filter. Subsequently, Otsu thresholding is used as an initial coarse segmentation method that finds the homogeneous regions of the input image. Finally, an enhanced suppressed fuzzy c-means is used to partition brain MR images into multiple segments, which employs an optimal suppression factor for the perfect clustering in the given data set. To evaluate the robustness of the proposed approach in noisy environment, we add different types of noise and different amount of noise to T1-weighted brain MR images. Experimental results show that the proposed algorithm outperforms other FCM based algorithms in terms of segmentation accuracy for both noise-free and noise-inserted MR images.

  14. SHORT COMMUNICATION PROXIMATE COMPOSITION, MINERAL ...

    African Journals Online (AJOL)

    Preferred Customer

    SHORT COMMUNICATION. PROXIMATE COMPOSITION, MINERAL CONTENT AND ANTINUTRITIONAL. FACTORS OF SOME CAPSICUM (Capsicum annum) VARIETIES GROWN IN. ETHIOPIA. Esayas K.1, Shimelis A.2, Ashebir F.3, Negussie R.3, Tilahun B.4 and Gulelat D.4*. 1Hawassa University, Department of Food ...

  15. Proximal tibiofibular dislocation: a case report and review of literature

    NARCIS (Netherlands)

    Nieuwe Weme, R. A.; Somford, M. P.; Schepers, T.

    2014-01-01

    An isolated dislocation of the proximal tibiofibular joint is uncommon. The mechanism of this injury is usually sports related. We present a case where initial X-rays did not show the tibiofibular joint dislocation conclusively. It was diagnosed after comparative bilateral AP X-rays of the knees

  16. Robust shape regression for supervised vessel segmentation and its application to coronary segmentation in CTA

    DEFF Research Database (Denmark)

    Schaap, Michiel; van Walsum, Theo; Neefjes, Lisan

    2011-01-01

    This paper presents a vessel segmentation method which learns the geometry and appearance of vessels in medical images from annotated data and uses this knowledge to segment vessels in unseen images. Vessels are segmented in a coarse-to-fine fashion. First, the vessel boundaries are estimated...... with multivariate linear regression using image intensities sampled in a region of interest around an initialization curve. Subsequently, the position of the vessel boundary is refined with a robust nonlinear regression technique using intensity profiles sampled across the boundary of the rough segmentation...... and using information about plausible cross-sectional vessel shapes. The method was evaluated by quantitatively comparing segmentation results to manual annotations of 229 coronary arteries. On average the difference between the automatically obtained segmentations and manual contours was smaller than...

  17. Temporal Proximity Promotes Integration of Overlapping Events.

    Science.gov (United States)

    Zeithamova, Dagmar; Preston, Alison R

    2017-08-01

    Events with overlapping elements can be encoded as two separate representations or linked into an integrated representation, yet we know little about the conditions that promote one form of representation over the other. Here, we tested the hypothesis that the proximity of overlapping events would increase the probability of integration. Participants first established memories for house-object and face-object pairs; half of the pairs were learned 24 hr before an fMRI session, and the other half 30 min before the session. During scanning, participants encoded object-object pairs that overlapped with the initial pairs acquired on the same or prior day. Participants were also scanned as they made inference judgments about the relationships among overlapping pairs learned on the same or different day. Participants were more accurate and faster when inferring relationships among memories learned on the same day relative to those acquired across days, suggesting that temporal proximity promotes integration. Evidence for reactivation of existing memories-as measured by a visual content classifier-was equivalent during encoding of overlapping pairs from the two temporal conditions. In contrast, evidence for integration-as measured by a mnemonic strategy classifier from an independent study [Richter, F. R., Chanales, A. J. H., & Kuhl, B. A. Predicting the integration of overlapping memories by decoding mnemonic processing states during learning. Neuroimage, 124, 323-335, 2016]-was greater for same-day overlapping events, paralleling the behavioral results. During inference itself, activation patterns further differentiated when participants were making inferences about events acquired on the same day versus across days. These findings indicate that temporal proximity of events promotes integration and further influences the neural mechanisms engaged during inference.

  18. Segmental neurofibromatosis and malignancy.

    Science.gov (United States)

    Dang, Julie D; Cohen, Philip R

    2010-01-01

    Segmental neurofibromatosis is an uncommon variant of neurofibromatosis type I characterized by neurofibromas and/or café-au-lait macules localized to one sector of the body. Although patients with neurofibromatosis type I have an associated increased risk of certain malignancies, malignancy has only occasionally been reported in patients with segmental neurofibromatosis. The published reports of patients with segmental neurofibromatosis who developed malignancy were reviewed and the characteristics of these patients and their cancers were summarized. Ten individuals (6 women and 4 men) with segmental neurofibromatosis and malignancy have been reported. The malignancies include malignant peripheral nerve sheath tumor (3), malignant melanoma (2), breast cancer (1), colon cancer (1), gastric cancer (1), lung cancer (1), and Hodgkin lymphoma (1). The most common malignancies in patients with segmental neurofibromatosis are derived from neural crest cells: malignant peripheral nerve sheath tumor and malignant melanoma. The incidence of malignancy in patients with segmental neurofibromatosis may approach that of patients with neurofibromatosis type I.

  19. Bizarre parosteal osteochondromatous proliferation of the proximal humerus: case report

    Energy Technology Data Exchange (ETDEWEB)

    Bush, J.B.; Meyer, Mark S. [Ochsner Clinic Foundation, Department of Orthopedics, New Orleans, LA (United States); Reith, John D. [University of Florida College of Medicine, Departments of Pathology, Immunology and Laboratory Medicine and Orthopaedics and Rehabilitation, Gainesville, Florida (United States)

    2007-06-15

    Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora's lesion, is a rare lesion of bone occurring predominantly in the long bones of the hands and feet. It exists as a puzzling clinical entity of uncertain origins and high recurrence rates after surgical resection. To our knowledge, this clinical entity has not been reported in the proximal aspect of the humerus. An interesting report of a lesion occurring in the proximal humerus, which initially was misinterpreted as a parosteal osteosarcoma, is discussed outlining the clinical, radiographic and pathologic features of the BPOP lesion. (orig.)

  20. Arthroscopic-assisted removal of proximal tibia locking plates

    Directory of Open Access Journals (Sweden)

    Gille Justus

    2012-05-01

    Full Text Available Abstract We present a new technique to remove plates from the proximal tibia arthroscopic-assisted with all advantages of the minimally invasive surgery and the possibility to treat concomitant intraarticular pathologies. The initial results (n = 7 are promising with an increase of the Lysholm score in all cases studied [preop. median 78 (range 32–100, postop. median 89 (range 60–100]. In conclusion, arthroscopic-assisted hardware removal at the proximal tibia is feasible and may provide patients with all the benefits of minimal-invasive hardware removal. The described technique can be recommended for all surgeons familiar with arthroscopic surgery.

  1. A Perspective On Segment Reporting Choices And Segment Reconciliations

    OpenAIRE

    Dana Hollie; Shaokun£¨Carol) Yu

    2015-01-01

    In 2014, segment reporting gained third place in SEC comment letters. This article reviews the history of segment reporting including segment reporting choices and segment reconciliations, the current concerns as the level of detail in segment disclosures varies widely across organizations, the value relevance of segment reconciliations and its market consequences, and the importance of segment reporting to management. The following are highlights of the manuscript: The third-most-common area...

  2. Photoactivated In Vivo Proximity Labeling.

    Science.gov (United States)

    Beck, David B; Bonasio, Roberto

    2017-06-19

    Identification of molecular interactions is paramount to understanding how cells function. Most available technologies rely on co-purification of a protein of interest and its binding partners. Therefore, they are limited in their ability to detect low-affinity interactions and cannot be applied to proteins that localize to difficult-to-solubilize cellular compartments. In vivo proximity labeling (IPL) overcomes these obstacles by covalently tagging proteins and RNAs based on their proximity in vivo to a protein of interest. In IPL, a heterobifunctional probe comprising a photoactivatable moiety and biotin is recruited by a monomeric streptavidin tag fused to a protein of interest. Following UV irradiation, candidate interacting proteins and RNAs are covalently biotinylated with tight spatial and temporal control and subsequently recovered using biotin as an affinity handle. Here, we describe experimental protocols to discover novel protein-protein and protein-RNA interactions using IPL. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  3. Prox-1 Automated Proximity Operations

    Science.gov (United States)

    2016-01-13

    on demonstrating the functionality required to meet minimum mission success criteria. The minimum mission includes on- orbit spacecraft checkout of...also includes deployment of LightSail-B from the P-POD, and imaging of LightSail-B for 20 minutes as it recedes from Prox-1. small satellite ; proximity...criteria. The minimum mission includes on- orbit spacecraft checkout of all spacecraft subsystems, including flight qualification of the following new

  4. Distributional cues and the onset bias in early word segmentation.

    Science.gov (United States)

    Babineau, Mireille; Shi, Rushen

    2014-12-01

    In previous infant studies on statistics-based word segmentation, the unit of statistical computation was always aligned with the syllabic edge, which had a consonant onset. The current study addressed whether the learning system imposes a constraint that favors word forms beginning with a consonant onset over those beginning with an onsetless sub-syllable, by examining infants' segmentation of vowel-initial non-words in French liaison. French-learning 20- and 24-month-old infants (N = 64) were familiarized with sentences containing variable liaison consonants preceding the same vowel-initial non-word (e.g., /n/onche, /z/onche, /r/onche, /t/onche), such that the distributional cues supported the sub-syllabic target (e.g., onche). After familiarization, we tested sub-syllabic statistical segmentation by presenting the vowel-initial target (e.g., onche) versus another non-familiarized vowel-initial word (e.g., èque). Another group of infants was tested with a consonant-initial mis-segmentation of the target (e.g., zonche) versus another non-familiarized consonant-initial word (e.g., zèque). Results showed that 20-month-olds failed to segment the vowel-initial targets, but they mis-segmented the targets as consonant-initial, indicating that the onset bias dominated over sub-syllabic statistics for word segmentation at this age. Twenty-four-month-olds showed ambiguous interpretations (i.e., both vowel-initial segmentation and consonant-initial mis-segmentation), suggesting that the use of statistics to segment sub-syllabic words was emerging while the onset bias continued to have an impact. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  5. The initial and subsequent inflammatory events during calcium oxalate lithiasis.

    Science.gov (United States)

    Yuen, John W M; Gohel, Mayur-Danny I; Poon, Ngork-Wah; Shum, Daisy K Y; Tam, Po-Chor; Au, Doris W T

    2010-08-05

    Crystallization is believed to be the initiation step of urolithiasis, even though it is unknown where inside the nephron the first crystal nucleation occurs. Direct nucleation of calcium oxalate and subsequent events including crystal retention, cellular damage, endocytosis, and hyaluronan (HA) expression, were tested in a two-compartment culture system with intact human proximal tubular HK-2 cell monolayer. Calcium oxalate dihydrate (COD) was nucleated and bound onto the apical surface of the HK-2 cells under hypercalciuric and hyperoxaluric conditions. These cells displayed mild cellular damage and internalized some of the adhered crystals within 18h post-COD-exposure, as revealed by electron microscopy. Prolonged incubation in complete medium caused significant damage to disrupt the monolayer integrity. Furthermore, hyaluronan disaccharides were detected in the harvested media, and were associated with HAS-3 mRNA expression. Human proximal cells were able to internalize COD crystals which nucleated directly onto the apical surface, subsequently triggering cellular damage and HAS-3 specific hyaluronan synthesis as an inflammatory response. The proximal tubule cells here demonstrate that it plays an important role in facilitating urolithiasis via endocytosis and creating an inflammatory environment whereby free hyaluronan in tubular fluid can act as crystal-binding molecule at the later segments of distal and collecting tubules. Copyright 2010 Elsevier B.V. All rights reserved.

  6. How to improve outcome in surgery for Proximal Hypospadias?

    Science.gov (United States)

    Qureshi, Abdul Hafeez; Zaidi, Syed Zafar

    2016-02-01

    To evaluate the role of subdartos fascial tissue as watertight layer in improving outcome for 2-stage proximal hypospadias surgery. The experimental study was conducted at the Department of Urology, Indus Hospital, Karachi, and comprised an audit of patients with proximal hypospadias who underwent surgery from July 1, 2007, to December 31, 2011. The initial two-stage repair of proximal hypospadias led to a high rate of urethrocutanous fistula formation (Group A), and, thus, a modification was introduced and subdartos facial double layer was applied over the urethral suture line (Group B). The results were compared regarding age, type of hypospadias, graft failure and urethrocutanous fistula in these patients. There were 27 patients in Group A and 16(59.3%) of them ended up having urethrocutanous fistula. Group B had 25 patients and only 2(8%) had fistula formation. The application of dartos facial flap waterproofing layer reduced fistula rate.

  7. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    Abstract. Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of ...

  8. Segmentation, advertising and prices

    NARCIS (Netherlands)

    Galeotti, Andrea; Moraga-González, José Luis

    This paper explores the implications of market segmentation on firm competitiveness. In contrast to earlier work, here market segmentation is minimal in the sense that it is based on consumer attributes that are completely unrelated to tastes. We show that when the market is comprised by two

  9. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of varying ...

  10. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  11. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-01-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  12. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-11-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  13. PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS

    African Journals Online (AJOL)

    DR. AMINU

    PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS. 1 Alhassan, A. J. 1M .S. Sule, 1J. ... ABSTRACT. This study determined the proximate and mineral element composition of whole white grubs using standard methods of analysis. Proximate ... days, before pulverized to powder and kept in plastic container.

  14. Clinical applicability of resin infiltration for proximal caries.

    Science.gov (United States)

    Altarabulsi, Mohammad Basel; Alkilzy, Mohammad; Splieth, Christian H

    2013-02-01

    Resin infiltration is a new microinvasive treatment to arrest the progress of proximal initial caries lesions. This study evaluated the clinical applicability of proximal caries infiltration. In the study population of 50 children, adolescents, and young adults (mean age, 17.3 ± 6.4 years), 10 dentists at the University of Greifswald, Greifswald, Germany, applied the infiltration material Icon on noncavitated proximal lesions in permanent and primary teeth as described by the manufacturer. The applicability was evaluated using two questionnaires filled out by clinicians and patients assessing the comfort, complexity, time, and difficulties of the application in comparison to a filling. The results showed good patient satisfaction with the procedure. The mean time for infiltration (24.3 ± 7.4 minutes), which included rubber dam application (7.7 ± 4 minutes) and the effort were perceived to be comparable to or even easier than a composite filling by clinicians. In three patients (6%), it was not possible to gain sufficient proximal space for the application of an infiltration. The location of the infiltrated tooth, separation problems, and the routine of clinicians with the infiltration technique had an effect on the duration of the infiltration. A clear learning curve with a reduction of treatment time for subsequent treatments was observed (P proximal lesion showed good clinical applicability for clinicians and very high acceptance by patients.

  15. A mathematical analysis to address the 6 degree-of-freedom segmental power imbalance.

    Science.gov (United States)

    Ebrahimi, Anahid; Collins, John D; Kepple, Thomas M; Takahashi, Kota Z; Higginson, Jill S; Stanhope, Steven J

    2018-01-03

    Segmental power is used in human movement analyses to indicate the source and net rate of energy transfer between the rigid bodies of biomechanical models. Segmental power calculations are performed using segment endpoint dynamics (kinetic method). A theoretically equivalent method is to measure the rate of change in a segment's mechanical energy state (kinematic method). However, these two methods have not produced experimentally equivalent results for segments proximal to the foot, with the difference in methods deemed the "power imbalance." In a 6 degree-of-freedom model, segments move independently, resulting in relative segment endpoint displacement and non-equivalent segment endpoint velocities at a joint. In the kinetic method, a segment's distal end translational velocity may be defined either at the anatomical end of the segment or at the location of the joint center (defined here as the proximal end of the adjacent distal segment). Our mathematical derivations revealed the power imbalance between the kinetic method using the anatomical definition and the kinematic method can be explained by power due to relative segment endpoint displacement. In this study, we tested this analytical prediction through experimental gait data from nine healthy subjects walking at a typical speed. The average absolute segmental power imbalance was reduced from 0.023 to 0.046 W/kg using the anatomical definition to ≤0.001 W/kg using the joint center definition in the kinetic method (95.56-98.39% reduction). Power due to relative segment endpoint displacement in segmental power analyses is substantial and should be considered in analyzing energetic flow into and between segments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. In vitro gene fusions that join an enzymatically active beta-galactosidase segment to amino-terminal fragments of exogenous proteins: Escherichia coli plasmid vectors for the detection and cloning of translational initiation signals.

    Science.gov (United States)

    Casadaban, M J; Chou, J; Cohen, S N

    1980-01-01

    We report the construction and use of a series of plasmid vectors suitable for the detection and cloning of translational control signals and 5' coding sequences of exogenously derived genes. In these plasmids, the first eight codons of the amino-terminal end of the lactose operon beta-galactosidase gene, lacZ, were removed, and unique BamHI, EcoRI, and SmaI (XmaI) endonuclease cleavage sites were incorporated adjacent to the eighth codon of lacZ. Introduction of deoxyribonucleic acid fragments containing appropriate regulatory signals and 5' coding sequences into such lac fusion plasmids led to the production of hybrid proteins consisting of the carboxyl-terminal segment of a beta-galactosidase remnant plus a peptide fragment that contained the amino-terminal amino acids encoded by the exogenous deoxyribonucleic acid sequence. These hybrid peptides retained beta-galactosidase enzymatic activity and yielded a Lac+ phenotype. Such hybrid proteins are useful for purifying peptide sequences encoded by exogenous deoxyribonucleic acid fragments and for studies relating the structure and function of specific peptide segments. Images PMID:6162838

  17. Salient object segmentation based on active contouring.

    Directory of Open Access Journals (Sweden)

    Xin Xia

    Full Text Available Traditional saliency detection algorithms lack object semantic character, and the segmentation algorithms cannot highlight the saliency of the segmentation regions. In order to compensate for the defects of these two algorithms, the salient object segmentation model, which is a novel combination of two algorithms, is established in this paper. With the help of a priori knowledge of image boundary background traits, the K-means++ algorithm is used to cluster the pixels for each region; in line with the sensitivity of the human eye to color and with its attention mechanism, the joint probability distribution of the regional contrast ratio and spatial saliency is established. The selection of the salient area is based on the probabilities, for which the region boundary is taken as the initial curve, and the level-set algorithm is used to perform the salient object segmentation of the image. The curve convergence condition is established according to the confidence level for the segmented region, thus avoiding over-convergence of the segmentation curve. With this method, the salient region boundary is adjacent to the object contour, so the curve evolution time is shorter, and compared with the traditional Li algorithm, the proposed algorithm has higher segmentation evaluation scores, with the additional benefit of emphasizing the importance of the object.

  18. English-learning infants' segmentation of verbs from fluent speech.

    Science.gov (United States)

    Nazzi, Thierry; Dilley, Laura C; Jusczyk, Ann Marie; Shattuck-Hufnagel, Stefanie; Jusczyk, Peter W

    2005-01-01

    Two experiments sought to extend the demonstration of English-learning infants' abilities to segment nouns from fluent speech to a new lexical class: verbs. Moreover, we explored whether two factors previously shown to influence noun segmentation, stress pattern (strong-weak or weak-strong) and type of initial phoneme (consonant or vowel), also influence verb segmentation. Our results establish the early emergence of verb segmentation in English: by 13.5 months for strong-weak consonant- or vowel-initial verbs and for weak-strong consonant-initial verbs; and by 16.5 months for weak-strong verbs beginning with a vowel. This generalizes previous reports of early segmentation to a new lexical class, thereby providing additional evidence that segmentation is likely to contribute to lexical acquisition. The effects of stress pattern and onset type found are similar to those previously obtained for nouns, in that verbs with a weak-strong stress pattern and verbs beginning with a vowel appear to be at a disadvantage in segmentation. Finally, we present prosodic analyses that suggest a possible effect of prosodic boundary and pitch accent distribution on segmentation. These prosodic differences potentially explain a developmental lag in verb segmentation observed in the present study compared to earlier findings for noun segmentation.

  19. Simultaneous segmentation and correspondence improvement using statistical modes

    Science.gov (United States)

    Sinha, Ayushi; Reiter, Austin; Leonard, Simon; Ishii, Masaru; Hager, Gregory D.; Taylor, Russell H.

    2017-02-01

    With the increasing amount of patient information that is being collected today, the idea of using this information to inform future patient care has gained momentum. In many cases, this information comes in the form of medical images. Several algorithms have been presented to automatically segment these images, and to extract structures relevant to different diagnostic or surgical procedures. Consequently, this allows us to obtain large data-sets of shapes, in the form of triangular meshes, segmented from these images. Given correspondences between these shapes, statistical shape models (SSMs) can be built using methods like Principal Component Analysis (PCA). Often, the initial correspondences between the shapes need to be improved, and SSMs can be used to improve these correspondences. However, just as often, initial segmentations also need to be improved. Unlike many correspondence improvement algorithms, which do not affect segmentation, many segmentation improvement algorithms negatively affect correspondences between shapes. We present a method that iteratively improves both segmentation as well as correspondence by using SSMs not only to improve correspondence, but also to constrain the movement of vertices during segmentation improvement. We show that our method is able to maintain correspondence while achieving as good or better segmentations than those produced by methods that improve segmentation without maintaining correspondence. We are additionally able to achieve segmentations with better triangle quality than segmentations produced without correspondence improvement.

  20. Poster - Thurs Eve-01: Comparison of clinical IMRT plan quality and delivery accuracy: Few large segments vs many small segments.

    Science.gov (United States)

    Sawchuk, S; Karnas, S; McCune, Kent; Mulligan, M; Dar, R; Chen, J

    2008-07-01

    Commercial radiation treatment planning systems for intensity modulation use optimization algorithms that can vary multi-leaf collimator (MLC) segment sizes, segment number and the minimum number of monitor units (MU) per segment. These parameters are varied according to the treatment site, size, location, and proximity to the organs at risk. This study compares the utility of optimization using (Case A) few large segments and a higher minimum MU per segment to that of (case B) using many smaller segments with a lower minimum MU per segment. For Case A, the patient benefits from a reduced treatment time associated with fewer MUs and fewer MLC movements and an increased accuracy in dose delivery. Also, shorter treatment times may lead to fewer patient movement uncertainties. The accumulated MLC leakage dose is reduced, the patient specific quality assurance (QA) is more manageable and small field modeling inaccuracies are reduced. Pinnacle-3 (v8) plans are generated with direct machine parameter optimization (DMPO) for both scenarios. Three dimensional dose distributions and dose volume histograms are used to compare plan quality. We compare plans using few large MLC segments with those using many small MLC segments for some clinical cases. Improved plan quality is demonstrated using fewer MLC segments. Dose QAs are performed and compared for each scenario using MapCheck and film. When comparing dose delivery accuracy between different MU per segment settings, a decrease in delivery errors with minimum MU size is observed. In conclusion, few large MLC segments with larger area should be used when possible. © 2008 American Association of Physicists in Medicine.

  1. Finger Proximal Interphalangeal Joint Dislocation.

    Science.gov (United States)

    Ramponi, Denise; Cerepani, Mary Jo

    2015-01-01

    Finger dislocations are common injuries that are often managed by emergency nurse practitioners. A systematic physical examination following these injuries is imperative to avoid complications. Radiographic views, including the anteroposterior, lateral, and oblique views, are imperative to evaluate these finger dislocations. A dorsal dislocation of the proximal interphalangeal (PIP) joint is the most common finger dislocation type often easily reduced. A volar PIP dislocation can often be difficult to reduce and may result in finger deformity. Finger dislocations should be reduced promptly. Referral to an orthopedic hand specialist is required if the dislocation is unable to be reduced or if the finger joint is unstable following reduction attempts.

  2. Equilibrium properties of proximity effect

    Energy Technology Data Exchange (ETDEWEB)

    Esteve, D.; Pothier, H.; Gueron, S.; Birge, N.O.; Devoret, M.

    1996-12-31

    The proximity effect in diffusive normal-superconducting (NS) nano-structures is described by the Usadel equations for the electron pair correlations. We show that these equations obey a variational principle with a potential which generalizes the Ginzburg-Landau energy functional. We discuss simple examples of NS circuits using this formalism. In order to test the theoretical predictions of the Usadel equations, we have measured the density of states as a function of energy on a long N wire in contact with a S wire at one end, at different distances from the NS interface. (authors). 12 refs.

  3. Pancreas and cyst segmentation

    Science.gov (United States)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  4. Complete dissociation of the HIV-1 gp41 ectodomain and membrane proximal regions upon phospholipid binding

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Julien; Louis, John M.; Aniana, Annie [National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Chemical Physics (United States); Ghirlando, Rodolfo [National Institutes of Health, Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Bax, Ad, E-mail: bax@nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Chemical Physics (United States)

    2015-04-15

    The envelope glycoprotein gp41 mediates the process of membrane fusion that enables entry of the HIV-1 virus into the host cell. Strong lipid affinity of the ectodomain suggests that its heptad repeat regions play an active role in destabilizing membranes by directly binding to the lipid bilayers and thereby lowering the free-energy barrier for membrane fusion. In such a model, immediately following the shedding of gp120, the N-heptad and C-heptad helices dissociate and melt into the host cell and viral membranes, respectively, pulling the destabilized membranes into juxtaposition, ready for fusion. Post-fusion, reaching the final 6-helix bundle (6HB) conformation then involves competition between intermolecular interactions needed for formation of the symmetric 6HB trimer and the membrane affinity of gp41’s ectodomain, including its membrane-proximal regions. Our solution NMR study of the structural and dynamic properties of three constructs containing the ectodomain of gp41 with and without its membrane-proximal regions suggests that these segments do not form inter-helical interactions until the very late steps of the fusion process. Interactions between the polar termini of the heptad regions, which are not associating with the lipid surface, therefore may constitute the main driving force initiating formation of the final post-fusion states. The absence of significant intermolecular ectodomain interactions in the presence of dodecyl phosphocholine highlights the importance of trimerization of gp41’s transmembrane helix to prevent complete dissociation of the trimer during the course of fusion.

  5. Familial segmental neurofibromatosis.

    Science.gov (United States)

    Oguzkan, Sibel; Cinbis, Mine; Ayter, Sükriye; Anlar, Banu; Aysun, Sabiha

    2004-05-01

    Segmental neurofibromatosis is considered to be the result of postzygotic NF1 gene mutations. We present a family in which the proband has generalized neurofibromatosis 1, whereas members of previous generations manifest segmental skin lesions. All, including the clinically asymptomatic grandmother, carry the same haplotype. This is the only case in the literature in which a parent with segmental skin findings has a child with full-blown neurofibromatosis 1 disease. The genetic mechanisms underlying this association are discussed. This family can be further investigated by examination of tissue samples from affected and unaffected sites for mutations.

  6. Multiple intramedullary nailing of proximal phalangeal fractures of hand

    Directory of Open Access Journals (Sweden)

    Patankar Hemant

    2008-01-01

    Full Text Available Background: Proximal phalangeal fractures are commonly encountered fractures in the hand. Majority of them are stable and can be treated by non-operative means. However, unstable fractures i.e. those with shortening, displacement, angulation, rotational deformity or segmental fractures need surgical intervention. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of these fractures with joint-sparing multiple intramedullary nailing technique. Materials and Methods: Thirty-five patients with 35 isolated unstable proximal phalangeal shaft fractures of hand were managed by surgical stabilization with multiple intramedullary nailing technique. Fractures of the thumb were excluded. All the patients were followed up for a minimum of six months. They were assessed radiologically and clinically. The clinical evaluation was based on two criteria. 1. total active range of motion for digital functional assessment as suggested by the American Society for Surgery of Hand and 2. grip strength. Results: All the patients showed radiological union at six weeks. The overall results were excellent in all the patients. Adventitious bursitis was observed at the point of insertion of nails in one patient. Conclusion: Joint-sparing multiple intramedullary nailing of unstable proximal phalangeal fractures of hand provides satisfactory results with good functional outcome and fewer complications.

  7. Skip segment Hirschsprung's disease: a systematic review.

    LENUS (Irish Health Repository)

    O'Donnell, Anne-Marie

    2012-02-01

    PURPOSE: Hirschsprung\\'s disease is characterised by the congenital absence of ganglion cells beginning in the distal rectum and extending proximally for varying distances. \\'Zonal aganglionosis\\' is a phenomenon involving a zone of aganglionosis occurring within normally innervated intestine. \\'Skip segment\\' Hirschsprung\\'s disease (SSHD) involves a \\'skip area\\' of normally ganglionated intestine, surrounded proximally and distally by aganglionosis. While Hirschsprung\\'s disease is believed to be the result of incomplete craniocaudal migration of neural crest-derived cells, the occurrence of SSHD has no clear embryological explanation. The aim of this study was to perform a systematic review of SSHD, reported in the literature between 1954 and 2009, in order to determine the clinical characteristics of this rare entity and its significance. METHODS: The first reported case of SSHD was published in 1954. A systematic review of SSHD cases in the literature, from 1954 to 2009, was carried out using the electronic database \\'Pubmed\\'. Detailed information was recorded regarding the age, gender, presenting symptoms and location of the skip segment in each patient. RESULTS: 24 cases of SSHD have been reported in the literature to date. 18\\/24 (75%) of these cases were males and 6\\/24 (25%) were females. Of these, 22\\/24 (92%) were cases of total colonic aganglionosis (TCA), and 2\\/24 (8%) were rectosigmoid Hirschsprung\\'s disease. Of the 22 TCA cases, 9 (41%) had a skip segment in the transverse colon, 6 (27%) in the ascending colon, 2 (9%) in the caecum and 5 (23%) had multiple skip segments. In both rectosigmoid Hirschsprung\\'s disease cases, the skip segment was in the sigmoid colon. Overall, the length of the skip segment was variable, with the entire transverse colon ganglionated in some cases. CONCLUSION: SSHD occurs predominantly in patients with TCA. The existence of a skip area of normally innervated colon in TCA may influence surgical

  8. Anterior segment optical coherence tomography for the quantitative evaluation of the anterior segment following Boston keratoprosthesis.

    Directory of Open Access Journals (Sweden)

    Joann J Kang

    Full Text Available OBJECTIVE: To quantitatively evaluate the anterior segment using anterior segment optical coherence tomography (AS-OCT following Boston keratoprosthesis type 1. METHODS: A retrospective study consisted of AS-OCT imaging at a single time point postoperatively in 52 eyes. Main outcomes measures include anatomical and functional anterior chamber depth (ACD, angle (ACA and peripheral and proximal synechiae. RESULTS: The mean time point of imaging was 19.3 months postoperatively. Average anatomical and functional ACD was 2.0 and 0.21 mm respectively, and mean ACA ranged from 2.5° to 6.14° in representative meridians. An average of 8.7 clock hours of angle closure was observed in the 25 eyes in which all meridians were imaged. The majority of eyes showed peripheral (86.5% and proximal (67.3% synechiae. CONCLUSIONS: AS-OCT is a useful tool for quantitative evaluation of anterior segment and angle after keratoprosthesis, which is otherwise poorly visible. The majority of eyes showed shallow ACD, extensive angle closure and synechiae formation.

  9. Anterior Segment Optical Coherence Tomography for the Quantitative Evaluation of the Anterior Segment Following Boston Keratoprosthesis

    Science.gov (United States)

    Kang, Joann J.; Allemann, Norma; Vajaranant, Thasarat; de la Cruz, Jose; Cortina, Maria Soledad

    2013-01-01

    Objective To quantitatively evaluate the anterior segment using anterior segment optical coherence tomography (AS-OCT) following Boston keratoprosthesis type 1. Methods A retrospective study consisted of AS-OCT imaging at a single time point postoperatively in 52 eyes. Main outcomes measures include anatomical and functional anterior chamber depth (ACD), angle (ACA) and peripheral and proximal synechiae. Results The mean time point of imaging was 19.3 months postoperatively. Average anatomical and functional ACD was 2.0 and 0.21 mm respectively, and mean ACA ranged from 2.5° to 6.14° in representative meridians. An average of 8.7 clock hours of angle closure was observed in the 25 eyes in which all meridians were imaged. The majority of eyes showed peripheral (86.5%) and proximal (67.3%) synechiae. Conclusions AS-OCT is a useful tool for quantitative evaluation of anterior segment and angle after keratoprosthesis, which is otherwise poorly visible. The majority of eyes showed shallow ACD, extensive angle closure and synechiae formation. PMID:23940621

  10. Active mask segmentation of fluorescence microscope images.

    Science.gov (United States)

    Srinivasa, Gowri; Fickus, Matthew C; Guo, Yusong; Linstedt, Adam D; Kovacević, Jelena

    2009-08-01

    We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the "contour" to that of "inside and outside," or masks, allowing for easy multidimensional segmentation. It adapts to the topology of the image through the use of multiple masks. The algorithm is almost invariant under initialization, allowing for random initialization, and uses a few easily tunable parameters. Experiments show that the active mask algorithm matches the ground truth well and outperforms the algorithm widely used in fluorescence microscopy, seeded watershed, both qualitatively, as well as quantitatively.

  11. Segmentation of antiperspirants and deodorants

    OpenAIRE

    Král, Tomáš

    2009-01-01

    The goal of Master's Thesis on topic Segmentation of antiperspirants and deodorants is to discover differences in consumer's behaviour, determinate and describe segments of consumers based on these differences and propose marketing strategy for the most attractive segments. Theoretical part describes market segmentation in general, process of segmentation and segmentation criteria. Analytic part characterizes Czech market of antiperspirants and deodorants, analyzes ACNielsen market data and d...

  12. Sclerosing segmental neurofibromatosis.

    Science.gov (United States)

    Lee, Joong Sun; Kim, You Chan

    2005-04-01

    Segmental neurofibromatosis is a rare disorder characterized by cafe-au-lait macules and/or neurofibromas limited to a single body segment. The neurofibromas in segmental neurofibromatosis are usually soft, non-tender nodules as in other types of neurofibromatosis. Histopathologically, they are usually non-encapsulated, loosely textured dermal tumors. We report a case of sclerosing segmental neurofibromatosis, in which the patient presented with several grouped, erythematous to brownish, firm tender nodules on the left side of the posterior neck. Histopathologically, the stroma was mostly very fibrotic, especially around hair follicles, in addition to the usual features of neurofibroma. The atypical clinical feature, hardness, and tenderness of the lesions may be associated with the fibrosis.

  13. Universal Numeric Segmented Display

    OpenAIRE

    Azad, Md. Abul Kalam; Sharmeen, Rezwana; S. M. Kamruzzaman

    2010-01-01

    Segmentation display plays a vital role to display numerals. But in today's world matrix display is also used in displaying numerals. Because numerals has lots of curve edges which is better supported by matrix display. But as matrix display is costly and complex to implement and also needs more memory, segment display is generally used to display numerals. But as there is yet no proposed compact display architecture to display multiple language numerals at a time, this paper proposes uniform...

  14. Strategic market segmentation

    Directory of Open Access Journals (Sweden)

    Maričić Branko R.

    2015-01-01

    Full Text Available Strategic planning of marketing activities is the basis of business success in modern business environment. Customers are not homogenous in their preferences and expectations. Formulating an adequate marketing strategy, focused on realization of company's strategic objectives, requires segmented approach to the market that appreciates differences in expectations and preferences of customers. One of significant activities in strategic planning of marketing activities is market segmentation. Strategic planning imposes a need to plan marketing activities according to strategically important segments on the long term basis. At the same time, there is a need to revise and adapt marketing activities on the short term basis. There are number of criteria based on which market segmentation is performed. The paper will consider effectiveness and efficiency of different market segmentation criteria based on empirical research of customer expectations and preferences. The analysis will include traditional criteria and criteria based on behavioral model. The research implications will be analyzed from the perspective of selection of the most adequate market segmentation criteria in strategic planning of marketing activities.

  15. Gamifying Video Object Segmentation.

    Science.gov (United States)

    Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

    2017-10-01

    Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

  16. Origin and consequences of western Mediterranean subduction, rollback, and slab segmentation

    NARCIS (Netherlands)

    van Hinsbergen, D.J.J.|info:eu-repo/dai/nl/269263624; Vissers, R.L.M.|info:eu-repo/dai/nl/068789203; Spakman, W.|info:eu-repo/dai/nl/074103164

    2014-01-01

    The western Mediterranean recorded subduction rollback, slab segmentation and separation. Here we address the questions of what caused Oligocene rollback initiation, and how its subsequent evolution split up an originally coherent fore arc into circum-southwest Mediterranean segments. We

  17. Complications in proximal humeral fractures.

    Science.gov (United States)

    Calori, Giorgio Maria; Colombo, Massimiliano; Bucci, Miguel Simon; Fadigati, Piero; Colombo, Alessandra Ines Maria; Mazzola, Simone; Cefalo, Vittorio; Mazza, Emilio

    2016-10-01

    Necrosis of the humeral head, infections and non-unions are among the most dangerous and difficult-to-treat complications of proximal humeral fractures. The aim of this work was to analyse in detail non-unions and post-traumatic bone defects and to suggest an algorithm of care. Treatment options are based not only on the radiological frame, but also according to a detailed analysis of the patient, who is classified using a risk factor analysis. This method enables the surgeon to choose the most suitable treatment for the patient, thereby facilitating return of function in the shortest possible time. The treatment of such serious complications requires the surgeon to be knowledgeable about the following possible solutions: increased mechanical stability; biological stimulation; and reconstructive techniques in two steps, with application of biotechnologies and prosthetic substitution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Rediscovering market segmentation.

    Science.gov (United States)

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  19. Segmentation and Representation of Consonant Blends in Kindergarten Children's Spellings

    Science.gov (United States)

    Werfel, Krystal L.; Schuele, C. Melanie

    2012-01-01

    Purpose: The purpose of this study was to describe the growth of children's segmentation and representation of consonant blends in the kindergarten year and to evaluate the extent to which linguistic features influence segmentation and representation of consonant blends. Specifically, the roles of word position (initial blends, final blends),…

  20. Proximity sensor technology for manipulator end effectors

    Science.gov (United States)

    Johnston, A. R.

    1975-01-01

    Optical proximity sensing techniques which could be used to help control the critical grasping phase of a remote manipulation are described. The proximity sensors described use a triangulation geometry to detect a surface located in a pre-determined region. The design of the proximity sensors themselves is discussed, as well as their application to manipulator control with a local control loop, and possibilities for future development are discussed.

  1. Segmental neurofibromatosis in childhood.

    Science.gov (United States)

    Listernick, Robert; Mancini, Anthony J; Charrow, Joel

    2003-08-30

    Segmental neurofibromatosis refers to individuals who have manifestations of neurofibromatosis type 1 (NF-1) limited to one area of the body. It results from a post-conceptional mutation in the NF-1 gene leading to somatic mosaicism. Although it is generally considered a rare condition, this report of 39 children with segmental NF-1 demonstrates that it is commonly seen in a pediatric NF-1 referral center. The mean age at diagnosis was 7.8 years (range: 2-25 years). Twenty-nine patients had only pigmentary manifestations of segmental NF-1, including seven who had only café-au-lait macules and 22 who had café-au-lait macules and freckling. Two patients had isolated plexiform neurofibromas; a third patient had a plexiform neurofibroma of the eyelid in addition to ipsilateral dysplasia of the sphenoid wing and Lisch nodules. A 12-year-old girl had an isolated tibial pseudarthrosis. An 8-year-old boy had an isolated optic pathway tumor, which behaved both biologically and radiographically as an NF1-associated tumor. While most children with segmental NF-1 have only localized pigmentary changes, some children will have isolated plexiform neurofibromas, pseudarthroses, or optic pathway tumors. Accurate diagnosis of segmental NF-1 is crucial for both management and genetic counseling. Copyright 2003 Wiley-Liss, Inc.

  2. Proximate composition and antinutrient content of pumpkin ...

    African Journals Online (AJOL)

    Proximate composition and antinutrient content of pumpkin ( Cucurbita pepo ) and sorghum ( Sorghum bicolor ) flour blends fermented with Lactobacillus plantarum , Aspergillus niger and Bacillus subtilis.

  3. Cooperative processes in image segmentation

    Science.gov (United States)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  4. Measurement of Na-K-ATPase-mediated rubidium influx in single segments of rat nephron

    Energy Technology Data Exchange (ETDEWEB)

    Cheval, L.; Doucet, A. (Centre National de la Recherche Scientifique, Paris (France))

    1990-07-01

    To determine the functioning rate of Na-K-ATPase in the rat nephron, a micromethod was developed to measure the rate of rubidium uptake in single nephron segments microdissected from collagenase-treated kidneys. Because the hydrolytic activity of Na-K-ATPase displayed the same apparent affinity for K and Rb ions, whereas the Vmax elicited by K was higher than that in the presence of Rb, experiments were performed in the presence of cold Rb plus 86Rb. Before the assay, tubules were preincubated for 10 min at 37 degrees C to restore the normal transmembrane cation gradients. 86Rb uptake was measured after washing out extracellular cations by rinsing the tubules in ice-cold choline chloride solution containing Ba2+. Rb uptake increased quasi-linearly as a function of incubation time up to 30 s in the thick ascending limb, 1 min in the proximal convoluted tubule, and 5 min in the collecting tubule, and reached an equilibrium after 5-30 min. The initial rates of Rb uptake increased in a saturable fashion as Rb concentration in the medium rose from 0.25 to 5 mM. In medullary thick ascending limb, the initial rate of Rb uptake was inhibited by greater than 90% by 2.5 mM ouabain and by 10(-5) M of the metabolic inhibitor carbonyl cyanide trifluoromethoxyphenylhydrazone. Correlation of Na-K-ATPase hydrolytic activity at Vmax and initial rates of ouabain-sensitive Rb uptake in the successive segments of nephron indicates that in intact cells the pump works at approximately 20-30% of its Vmax. Increasing intracellular Na concentration by tubule preincubation in a Rb- and K-free medium increased the initial rates of Rb intake up to the Vmax of the hydrolytic activity of the pump.

  5. Chan-Vese Segmentation

    Directory of Open Access Journals (Sweden)

    Pascal Getreuer

    2012-08-01

    Full Text Available While many segmentation methods rely heavily in some way on edge detection, the "Active Contours Without Edges" method by Chan and Vese ignores edges completely. Instead, the method optimally fits a two-phase piecewise constant model to the given image. The segmentation boundary is represented implicitly with a level set function, which allows the segmentation to handle topological changes more easily than explicit snake methods. This article describes the level set formulation of the Chan–Vese model and its numerical solution using a semi-implicit gradient descent. We also discuss the Chan–Sandberg–Vese method, a straightforward extension of Chan–Vese for vector-valued images.

  6. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  7. Coupled Shape Model Segmentation in Pig Carcasses

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Larsen, Rasmus; Ersbøll, Bjarne Kjær

    2006-01-01

    In this paper we are concerned with multi-object segmentation. For each object we will train a level set function based shape prior from a sample set of outlines. The outlines are aligned in a multi-resolution scheme wrt. an Euclidean similarity transformation in order to maximize the overlap...... the initialization of the next search from already found objects; 2) all objects are found simultaneously and a repelling force is introduced in order to avoid overlap between outlines in the solution. The methods are applied to segmentation of cross sections of muscles in slices of CT scans of pig backs for quality...

  8. Self-assembling segmented coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  9. Robotic Arm Comprising Two Bending Segments

    Science.gov (United States)

    Mehling, Joshua S.; Difler, Myron A.; Ambrose, Robert O.; Chu, Mars W.; Valvo, Michael C.

    2010-01-01

    The figure shows several aspects of an experimental robotic manipulator that includes a housing from which protrudes a tendril- or tentacle-like arm 1 cm thick and 1 m long. The arm consists of two collinear segments, each of which can be bent independently of the other, and the two segments can be bent simultaneously in different planes. The arm can be retracted to a minimum length or extended by any desired amount up to its full length. The arm can also be made to rotate about its own longitudinal axis. Some prior experimental robotic manipulators include single-segment bendable arms. Those arms are thicker and shorter than the present one. The present robotic manipulator serves as a prototype of future manipulators that, by virtue of the slenderness and multiple- bending capability of their arms, are expected to have sufficient dexterity for operation within spaces that would otherwise be inaccessible. Such manipulators could be especially well suited as means of minimally invasive inspection during construction and maintenance activities. Each of the two collinear bending arm segments is further subdivided into a series of collinear extension- and compression-type helical springs joined by threaded links. The extension springs occupy the majority of the length of the arm and engage passively in bending. The compression springs are used for actively controlled bending. Bending is effected by means of pairs of antagonistic tendons in the form of spectra gel spun polymer lines that are attached at specific threaded links and run the entire length of the arm inside the spring helix from the attachment links to motor-driven pulleys inside the housing. Two pairs of tendons, mounted in orthogonal planes that intersect along the longitudinal axis, are used to effect bending of each segment. The tendons for actuating the distal bending segment are in planes offset by an angle of 45 from those of the proximal bending segment: This configuration makes it possible to

  10. Costs and effectiveness of treatment alternatives for proximal caries lesions.

    Directory of Open Access Journals (Sweden)

    Falk Schwendicke

    Full Text Available OBJECTIVES: Invasive therapy of proximal caries lesions initiates a cascade of re-treatment cycles with increasing loss of dental hard tissue. Non- and micro-invasive treatment aim at delaying this cascade and may thus reduce both the health and economic burden of such lesions. This study compared the costs and effectiveness of alternative treatments of proximal caries lesions. METHODS: A Markov-process model was used to simulate the events following the treatment of a proximal posterior lesion (E2/D1 in a 20-year-old patient in Germany. We compared three interventions (non-invasive; micro-invasive using resin infiltration; invasive using composite restoration. We calculated the risk of complications of initial and possible follow-up treatments and modelled time-dependent non-linear transition probabilities. Costs were calculated based on item-fee catalogues in Germany. Monte-Carlo-microsimulations were performed to compare cost-effectiveness of non- versus micro-invasive treatment and to analyse lifetime costs of all three treatments. RESULTS: Micro-invasive treatment was both more costly and more effective than non-invasive therapy, with ceiling-value-thresholds for willingness-to-pay between 16.73 € for E2 and 1.57 € for D1 lesions. Invasive treatment was the most costly strategy. Calculated costs and effectiveness were sensitive to lesion stage, patient's age, discounting rate and assumed initial treatment costs. CONCLUSIONS: Non- and micro-invasive treatments have lower long-term costs than invasive therapy of proximal lesions. Micro-invasive therapy had the highest cost-effectiveness for treating D1 lesions in young patients. Decision makers with a willingness-to-pay over 16.73 € and 1.57 € for E2 and D1 lesions, respectively, will find micro-invasive treatment more cost-effective than non-invasive therapy.

  11. Costs and effectiveness of treatment alternatives for proximal caries lesions.

    Science.gov (United States)

    Schwendicke, Falk; Meyer-Lueckel, Hendrik; Stolpe, Michael; Dörfer, Christof Edmund; Paris, Sebastian

    2014-01-01

    Invasive therapy of proximal caries lesions initiates a cascade of re-treatment cycles with increasing loss of dental hard tissue. Non- and micro-invasive treatment aim at delaying this cascade and may thus reduce both the health and economic burden of such lesions. This study compared the costs and effectiveness of alternative treatments of proximal caries lesions. A Markov-process model was used to simulate the events following the treatment of a proximal posterior lesion (E2/D1) in a 20-year-old patient in Germany. We compared three interventions (non-invasive; micro-invasive using resin infiltration; invasive using composite restoration). We calculated the risk of complications of initial and possible follow-up treatments and modelled time-dependent non-linear transition probabilities. Costs were calculated based on item-fee catalogues in Germany. Monte-Carlo-microsimulations were performed to compare cost-effectiveness of non- versus micro-invasive treatment and to analyse lifetime costs of all three treatments. Micro-invasive treatment was both more costly and more effective than non-invasive therapy, with ceiling-value-thresholds for willingness-to-pay between 16.73 € for E2 and 1.57 € for D1 lesions. Invasive treatment was the most costly strategy. Calculated costs and effectiveness were sensitive to lesion stage, patient's age, discounting rate and assumed initial treatment costs. Non- and micro-invasive treatments have lower long-term costs than invasive therapy of proximal lesions. Micro-invasive therapy had the highest cost-effectiveness for treating D1 lesions in young patients. Decision makers with a willingness-to-pay over 16.73 € and 1.57 € for E2 and D1 lesions, respectively, will find micro-invasive treatment more cost-effective than non-invasive therapy.

  12. GrabCut-Based Human Segmentation in Video Sequences

    Science.gov (United States)

    Hernández-Vela, Antonio; Reyes, Miguel; Ponce, Víctor; Escalera, Sergio

    2012-01-01

    In this paper, we present a fully-automatic Spatio-Temporal GrabCut human segmentation methodology that combines tracking and segmentation. GrabCut initialization is performed by a HOG-based subject detection, face detection, and skin color model. Spatial information is included by Mean Shift clustering whereas temporal coherence is considered by the historical of Gaussian Mixture Models. Moreover, full face and pose recovery is obtained by combining human segmentation with Active Appearance Models and Conditional Random Fields. Results over public datasets and in a new Human Limb dataset show a robust segmentation and recovery of both face and pose using the presented methodology. PMID:23202215

  13. Segmental Neurofibromatosis: Atypical Localisation

    Directory of Open Access Journals (Sweden)

    Filiz Topaloğlu Demir

    2015-06-01

    Full Text Available Neurofibromatosis (NF is a genetic disease leading pathological findings in skin, soft tissue, bone and nervous system by affecting neural crest cells. Due to its heterogeneity neurofibromatosis was divided into eight different subgroups (NF-I NF-VIII by Riccardi. Segmental neurofibromatosis (NF type V is characterized by cutaneous neurofibromas and Café-au-lait spots limited with a segment of dermatome. Here we report this case with numerous, painless cutaneous nodules showing extension from the shoulder to the dorsal aspect of the right hand, since it a rare case.

  14. Generation of a genetically encoded marker of rod photoreceptor outer segment growth and renewal

    Directory of Open Access Journals (Sweden)

    John J. Willoughby

    2011-10-01

    Vertebrate photoreceptors are specialized light sensing neurons. The photoreceptor outer segment is a highly modified cilium where photons of light are transduced into a chemical and electrical signal. The outer segment has the typical cilary axoneme but, in addition, it has a large number of densely packed, stacked, intramembranous discs. The molecular and cellular mechanisms that contribute to vertebrate photoreceptor outer segment morphogenesis are still largely unknown. Unlike typical cilia, the outer segment is continuously regenerated or renewed throughout the life of the animal through the combined process of distal outer segment shedding and proximal outer segment growth. The process of outer segment renewal was discovered over forty years ago, but we still lack an understanding of how photoreceptors renew their outer segments and few, if any, molecular mechanisms that regulate outer segment growth or shedding have been described. Our lack of progress in understanding how photoreceptors renew their outer segments has been hampered by the difficulty in measuring rates of renewal. We have created a new method that uses heat-shock induction of a fluorescent protein that can be used to rapidly measure outer segment growth rates. We describe this method, the stable transgenic line we created, and the growth rates observed in larval and adult rod photoreceptors using this new method. This new method will allow us to begin to define the genetic and molecular mechanisms that regulate rod outer segment renewal, a crucial aspect of photoreceptor function and, possibly, viability.

  15. Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures

    OpenAIRE

    Thyagarajan David; Haridas Samarth; Jones Denise; Dent Colin; Evans Richard; Williams Rhys

    2009-01-01

    Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system) for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES) score and Constant Murley score. Results: Average age of the patients was 58 years...

  16. Best Proximity Points for a New Class of Generalized Proximal Mappings

    Directory of Open Access Journals (Sweden)

    Tayyab Kamran

    2017-03-01

    Full Text Available The best proximity points are usually used to find the optimal approximate solution of the operator equation Tx = x, when T has no fixed point. In this paper, we prove some best proximity point theorems for nonself multivalued operators, following the foot steps of Basha and Shahzad [Best proximity point theorems for generalized proximal contractions, Fixed Point Theory Appl., 2012, 2012:42].

  17. Optical proximity correction with principal component regression

    Science.gov (United States)

    Gao, Peiran; Gu, Allan; Zakhor, Avideh

    2008-03-01

    An important step in today's Integrated Circuit (IC) manufacturing is optical proximity correction (OPC). In model based OPC, masks are systematically modified to compensate for the non-ideal optical and process effects of optical lithography system. The polygons in the layout are fragmented, and simulations are performed to determine the image intensity pattern on the wafer. Then the mask is perturbed by moving the fragments to match the desired wafer pattern. This iterative process continues until the pattern on the wafer matches the desired one. Although OPC increases the fidelity of pattern transfer to the wafer, it is quite CPU intensive; OPC for modern IC designs can take days to complete on computer clusters with thousands of CPU. In this paper, techniques from statistical machine learning are used to predict the fragment movements. The goal is to reduce the number of iterations required in model based OPC by using a fast and efficient solution as the initial guess to model based OPC. To determine the best model, we train and evaluate several principal component regression models based on prediction error. Experimental results show that fragment movement predictions via regression model significantly decrease the number of iterations required in model based OPC.

  18. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule

    DEFF Research Database (Denmark)

    Lee, Justin J; Plain, Allein; Beggs, Megan R

    2017-01-01

    as their regulation of active vitamin D 3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms......Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH...... of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance....

  19. Preliminary phytochemical screening, proximate and elemental ...

    African Journals Online (AJOL)

    The seed powder of Moringa oleifera was analysed for its phytochemical, proximate and elemental composition using Folin-Denis spectrophotometric method, gravimetric method and energy dispersing X-ray fluorescence (EDXRF) transmission emission technique respectively. The seed powder had the following proximate ...

  20. Bimalleolar ankle fracture with proximal fibular fracture

    NARCIS (Netherlands)

    Colenbrander, R. J.; Struijs, P. A. A.; Ultee, J. M.

    2005-01-01

    A 56-year-old female patient suffered a bimalleolar ankle fracture with an additional proximal fibular fracture. This is an unusual fracture type, seldom reported in literature. It was operatively treated by open reduction and internal fixation of the lateral malleolar fracture. The proximal fibular

  1. Grouping by Proximity in Haptic Contour Detection

    Science.gov (United States)

    Overvliet, Krista E.; Krampe, Ralf Th.; Wagemans, Johan

    2013-01-01

    We investigated the applicability of the Gestalt principle of perceptual grouping by proximity in the haptic modality. To do so, we investigated the influence of element proximity on haptic contour detection. In the course of four sessions ten participants performed a haptic contour detection task in which they freely explored a haptic random dot display that contained a contour in 50% of the trials. A contour was defined by a higher density of elements (raised dots), relative to the background surface. Proximity of the contour elements as well as the average proximity of background elements was systematically varied. We hypothesized that if proximity of contour elements influences haptic contour detection, detection will be more likely when contour elements are in closer proximity. This should be irrespective of the ratio with the proximity of the background elements. Results showed indeed that the closer the contour elements were, the higher the detection rates. Moreover, this was the case independent of the contour/background ratio. We conclude that the Gestalt law of proximity applies to haptic contour detection. PMID:23762364

  2. Proximate analysis on four edible mushrooms ADEDAYO ...

    African Journals Online (AJOL)

    Michael Horsfall

    Vol. 15 (1) 9 - 11. Full-text Available Online at www.bioline.org.br/ja. Proximate analysis on four edible mushrooms. ADEDAYO, MAJEKODUNMI RACHEL. Nigerian Stored Product Research Institute, P.M.B.3032, Kano. ABSTRACT: Proximate study was conducted on four edible mushrooms commonly found in farmlands in.

  3. Proximate Sources of Collective Teacher Efficacy

    Science.gov (United States)

    Adams, Curt M.; Forsyth, Patrick B.

    2006-01-01

    Purpose: Recent scholarship has augmented Bandura's theory underlying efficacy formation by pointing to more proximate sources of efficacy information involved in forming collective teacher efficacy. These proximate sources of efficacy information theoretically shape a teacher's perception of the teaching context, operationalizing the difficulty…

  4. Phytochemical screening, proximate analysis and anticonvulsant ...

    African Journals Online (AJOL)

    Spigelia anthelmia is used traditionally in Southern Nigeria for the treatment of infant convulsion and epilepsy. This study investigated the phytochemical constituents, proximate analysis and anticonvulsant effect of the methanolic extract of Spigelia anthelmia. Phytochemical evaluation and proximate analysis was carried ...

  5. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...

  6. Thoracoscopic Subsuperior Segment Segmentectomy.

    Science.gov (United States)

    Shimizu, Kimihiro; Mogi, Akira; Yajima, Toshiki; Nagashima, Toshiteru; Ohtaki, Yoichi; Obayashi, Kai; Nakazawa, Seshiru; Kosaka, Takayuki; Kuwano, Hiroyuki

    2017-11-01

    To date, anatomic subsuperior segment (S∗) segmentectomy has not yet been reported. Herein we report the technical details of thoracoscopic anatomic S∗ segmentectomy and the anatomic features of the S∗. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Segmentation and crustal structure

    Indian Academy of Sciences (India)

    N; J. Geophys. Res. 105 8205–8226. Kamesh Raju K A, Ramprasad T and Subrahmanyam C. 1997 Geophysical investigations over a segment of the. Central Indian Ridge, Indian Ocean; Geo-Marine Lett. 17. 195–201. Kamesh Raju K A, Chaubey A K, Amarnath Dileep and. Mudholkar Abhay 2008 Morphotectonics of the ...

  8. Connecting textual segments

    DEFF Research Database (Denmark)

    Brügger, Niels

    2017-01-01

    history than just the years of the emergence of the web, the chapter traces the history of how segments of text have deliberately been connected to each other by the use of specific textual and media features, from clay tablets, manuscripts on parchment, and print, among others, to hyperlinks on stand......-alone computers and in local and global digital networks....

  9. Sipunculans and segmentation

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora

    2009-01-01

    Comparative molecular, developmental and morphogenetic analyses show that the three major segmented animal groups- Lophotrochozoa, Ecdysozoa and Vertebrata-use a wide range of ontogenetic pathways to establish metameric body organization. Even in the life history of a single specimen, different m...

  10. CORNEA AND ANTERIOR SEGMENT

    African Journals Online (AJOL)

    2016-11-04

    Nov 4, 2016 ... 24. Nigerian Journal of Ophthalmology / Supplement 1 - 2014 - Volume 22. S24. CORNEA AND ANTERIOR SEGMENT. A Comparison of Visual Outcomes after Extracapsular Cataract. Surgery and Phacoemulsification in Eye Foundation Hospital. Lagos Nigeria. Oderinlo O. O., Hassan A. O., Oluyadi F. O., ...

  11. Labor market segmentation

    OpenAIRE

    Berndt Christian

    2017-01-01

    This contribution to the International Encyclopedia of Geography is a reinterpretation of labor market segmentation theories mapping the evolution of this perspective on labor markets and using the findings of the care market project to reflect on the rising importance of female migrant labor in the domestic sphere and the question of diversity and inequalities in the labor market.

  12. Research of the multimodal brain-tumor segmentation algorithm

    Science.gov (United States)

    Lu, Yisu; Chen, Wufan

    2015-12-01

    It is well-known that the number of clusters is one of the most important parameters for automatic segmentation. However, it is difficult to define owing to the high diversity in appearance of tumor tissue among different patients and the ambiguous boundaries of lesions. In this study, a nonparametric mixture of Dirichlet process (MDP) model is applied to segment the tumor images, and the MDP segmentation can be performed without the initialization of the number of clusters. A new nonparametric segmentation algorithm combined with anisotropic diffusion and a Markov random field (MRF) smooth constraint is proposed in this study. Besides the segmentation of single modal brain tumor images, we developed the algorithm to segment multimodal brain tumor images by the magnetic resonance (MR) multimodal features and obtain the active tumor and edema in the same time. The proposed algorithm is evaluated and compared with other approaches. The accuracy and computation time of our algorithm demonstrates very impressive performance.

  13. Intramedullary compression device for proximal ulna fracture.

    Science.gov (United States)

    Hong, Choon Chiet; Han, Fucai; Decruz, Joshua; Pannirselvam, Vinodhkumar; Murphy, Diarmuid

    2015-02-01

    Proximal ulna fractures account for 20% of all proximal forearm fractures. Many treatment options are available for such fractures, such as cast immobilisation, plate and screw fixation, tension band wiring and intramedullary screw fixation, depending on the fracture pattern. Due to the subcutaneous nature of the proximal forearm, it is vulnerable to open injuries over the dorsal aspect of the proximal ulna. This may in turn prove challenging, as it is critical to obtain adequate soft tissue coverage to reduce the risk of implant exposure and bony infections. We herein describe a patient with a Gustillo III-B open fracture of the proximal ulna, treated with minimally invasive intramedullary screw fixation using a 6.0-mm cannulated headless titanium compression screw (FusiFIX, Péronnas, France).

  14. Comparative genomic hybridization: Detection of segmental aneusomies

    Energy Technology Data Exchange (ETDEWEB)

    Cronin, J.E.; Magrane, G.G.; Gray, J.W. [Univ. of California, San Francisco, CA (United States)] [and others

    1994-09-01

    Comparative genomic hybridization (CGH) has been used successfully to detect whole chromosome and segmental aneusomies. However, its sensitivity for detection of segmental aneusomies is still not well known. We present here an analysis of CGH sensitivity with emphasis on detection of abnormalities commonly found during pre-and neo-natal diagnosis. CGH is performed by hybridizing green and red fluorescing test and normal DNA samples, respectively, to normal metaphase spreads and measuring green:red fluorescence ratios along all chromosomes. The ratios are normalized such that 2 copies of a normal chromosome region in the test sample gives a ratio of 1.0. Alterations in test vs. control gene copy number range from 1.5 [trisomy] to 0.5 [monosomy]. Clinical samples analyzed included Wolf Hirschhorn (4p-), Cri du Chat (5p-) and DiGeorge (22q-). In addition, 7 cell lines with chromosome 21 segmental aneusomies were analyzed. These included 3 with terminal duplications, 1 with a terminal deletion, 1 with an interstitial deletion and 2 with interstitial amplifications. The DiGeorge deletion was the only deletion not deleted by CGH. This is not surprising as standard G banding does not routinely detect this 1-2 megabase deletion. The 4p- and 5p- monosomies were detected and breakpoints correctly assigned prospectively. Proximal alterations involving 21q22.11 are unambiguously defined. Specifically, two interstitial aneusomies involving this region are detected. Studies involving late prophase chromosome normal spreads gave identical breakpoints. Thus, analysis of extended chromosomes did not improve the sensitivity of the technique. Taken together, these data suggest that CGH can detect segmental aneusomies greater than 8 megabases in extent. Smaller aneusomies can, at times, be detected. Work is now underway to modify the analysis software to increase sensitivity and to decrease the amount of material needed for analysis.

  15. Patent vitellointestinal duct with prolapsed (intussusceptions of proximal and distal ileal loop: A case report

    Directory of Open Access Journals (Sweden)

    Dinesh D. Mundada

    2015-02-01

    Full Text Available A wide variety of anomalies may occur as a result of the vitellointestinal duct (VID failing to obliterate completely. VID is well known because of its various complication and presentation most commonly due to Meckel's diverticulum. Small bowel prolapsed through patent VID is one of the rare presentations that have been reported. We are reporting a case of patent VID through which proximal and distal ileal segment had been intussuscepted and prolapsed through umbilicus.

  16. Segmentation of thermographic images of hands using a genetic algorithm

    Science.gov (United States)

    Ghosh, Payel; Mitchell, Melanie; Gold, Judith

    2010-01-01

    This paper presents a new technique for segmenting thermographic images using a genetic algorithm (GA). The individuals of the GA also known as chromosomes consist of a sequence of parameters of a level set function. Each chromosome represents a unique segmenting contour. An initial population of segmenting contours is generated based on the learned variation of the level set parameters from training images. Each segmenting contour (an individual) is evaluated for its fitness based on the texture of the region it encloses. The fittest individuals are allowed to propagate to future generations of the GA run using selection, crossover and mutation. The dataset consists of thermographic images of hands of patients suffering from upper extremity musculo-skeletal disorders (UEMSD). Thermographic images are acquired to study the skin temperature as a surrogate for the amount of blood flow in the hands of these patients. Since entire hands are not visible on these images, segmentation of the outline of the hands on these images is typically performed by a human. In this paper several different methods have been tried for segmenting thermographic images: Gabor-wavelet-based texture segmentation method, the level set method of segmentation and our GA which we termed LSGA because it combines level sets with genetic algorithms. The results show a comparative evaluation of the segmentation performed by all the methods. We conclude that LSGA successfully segments entire hands on images in which hands are only partially visible.

  17. Disruption of the proximal tibiofibular joint in the setting of multi-ligament knee injury

    Energy Technology Data Exchange (ETDEWEB)

    Porrino, Jack A. [University of Washington, Department of Radiology, 4245 Roosevelt Way NE, Box 354755, Seattle, WA (United States)

    2015-08-15

    Instability of the proximal tibiofibular joint is a relatively uncommon condition when in isolation; however, instability of the proximal tibiofibular joint is far more frequent in those presenting with a severe multi-ligament injury of the knee. If this joint is left unstable, repair of a co-existent injury of the posterolateral corner may fail, regardless of the proficiency of the technique. We present two patients with disruption of the proximal tibiofibular joint, including the MRI appearance, who initially presented to our hospital for management of significant polytrauma, as well as multi-ligament injury of the ipsilateral knee. (orig.)

  18. STRaND-2: Visual inspection, proximity operations & nanosatellite docking

    Science.gov (United States)

    Bridges, C. P.; Taylor, B.; Horri, N.; Underwood, C. I.; Kenyon, S.; Barrera-Ars, J.; Pryce, L.; Bird, R.

    The Surrey Training Research and Nanosatellite Demonstrator (STRaND) programme has been success in identifying and creating a leading low-cost nanosatellite programme with advanced attitude and orbit control system (AOCS) and experimental computing platforms based on smart-phone technologies. The next demonstration capabilities, that provide a challenging mission to the existing STRaND platform, is to perform visual inspection, proximity operations and nanosatellite docking. Visual inspection is to be performed using a COTS LIDAR system to estimate range and pose under 100 m. Proximity operations are controlled using a comprehensive guidance, navigation and control (GNC) loop in a polar form of the Hills Clohessy Wiltshire (HCW) frame including J2 perturbations. And finally, nanosatellite docking is performed at under 30 cm using a series of tuned magnetic coils. This paper will document the initial experiments and calculations used to qualify LIDAR components, size the mission thrust and tank requirements, and air cushion table demonstrations of the docking mechanism.

  19. Molecular basis for photoreceptor outer segment architecture.

    Science.gov (United States)

    Goldberg, Andrew F X; Moritz, Orson L; Williams, David S

    2016-11-01

    To serve vision, vertebrate rod and cone photoreceptors must detect photons, convert the light stimuli into cellular signals, and then convey the encoded information to downstream neurons. Rods and cones are sensory neurons that each rely on specialized ciliary organelles to detect light. These organelles, called outer segments, possess elaborate architectures that include many hundreds of light-sensitive membranous disks arrayed one atop another in precise register. These stacked disks capture light and initiate the chain of molecular and cellular events that underlie normal vision. Outer segment organization is challenged by an inherently dynamic nature; these organelles are subject to a renewal process that replaces a significant fraction of their disks (up to ∼10%) on a daily basis. In addition, a broad range of environmental and genetic insults can disrupt outer segment morphology to impair photoreceptor function and viability. In this chapter, we survey the major progress that has been made for understanding the molecular basis of outer segment architecture. We also discuss key aspects of organelle lipid and protein composition, and highlight distributions, interactions, and potential structural functions of key OS-resident molecules, including: kinesin-2, actin, RP1, prominin-1, protocadherin 21, peripherin-2/rds, rom-1, glutamic acid-rich proteins, and rhodopsin. Finally, we identify key knowledge gaps and challenges that remain for understanding how normal outer segment architecture is established and maintained. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Segmentation in Tardigrada and diversification of segmental patterns in Panarthropoda.

    Science.gov (United States)

    Smith, Frank W; Goldstein, Bob

    2017-05-01

    The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Application of Anterior Segment Optical Coherence Tomography in Pediatric Ophthalmology

    Directory of Open Access Journals (Sweden)

    Ricardo Salles Cauduro

    2012-01-01

    Full Text Available Purpose. Application of anterior segment optical coherence (AS-OCT in pediatric ophthalmology. Methods. Retrospective clinical study case series of 26 eyes of 19 pediatric patients throughout a 21-month period, presenting anterior segment pathologies, were submitted to AS-OCT examination (OCT Visante, 1310 nm, Zeiss, noncontact technique, no sedation requirement. Results. AS-OCT images were obtained from 19 patients (range: 2 months to 12 years. Clinical diagnosis of anterior segment abnormalities included cornea disease (n=7, congenital anterior segment conditions (n=10, ocular trauma (n=1, anterior segment surgeries (n=2, iridocorneal angle abnormalities (n=4, intermediate uveitis (n=2. The most common OCT findings were corneal hyperreflectivity and thickening (n=15, shallow anterior chamber with iris-lens diaphragm anterior displacement (n=4, atypical corneal curvature (n=4, corneal thinning (n=4, peripheral synechiae with angle closure (n=3, increased anterior chamber depth (n=2, and proximal portion of glaucoma drainage tube (n=2. Conclusion. In the present study, noncontact AS-OCT demonstrated to be a feasible technique to evaluate the anterior segment providing anatomic details and useful to clarify diagnosis in the pediatric population.

  2. Brain blood vessel segmentation using line-shaped profiles

    Science.gov (United States)

    Babin, Danilo; Pižurica, Aleksandra; De Vylder, Jonas; Vansteenkiste, Ewout; Philips, Wilfried

    2013-11-01

    Segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, especially for embolization of cerebral aneurysms and arteriovenous malformations (AVMs). In order to perform embolization of the AVM, the structural and geometric information of blood vessels from 3D images is of utmost importance. For this reason, the in-depth segmentation of cerebral blood vessels is usually done as a fusion of different segmentation techniques, often requiring extensive user interaction. In this paper we introduce the idea of line-shaped profiling with an application to brain blood vessel and AVM segmentation, efficient both in terms of resolving details and in terms of computation time. Our method takes into account both local proximate and wider neighbourhood of the processed pixel, which makes it efficient for segmenting large blood vessel tree structures, as well as fine structures of the AVMs. Another advantage of our method is that it requires selection of only one parameter to perform segmentation, yielding very little user interaction.

  3. [Clinical analysis of prosthesis replacement for proximal humerus tumors].

    Science.gov (United States)

    Weng, Xiaojun; Liao, Qiande; Li, Xiaosheng; Wang, Jing

    2016-01-01

    To explore surgical strategies, functions and prognosis of artificial prosthesis replacement and soft tissue reconstruction for patients with invasive benign or primary malignant proximal humerus tumor.
 A total of 17 patients with invasive benign or primary malignant proximal humerus tumor underwent prosthetic replacement after segment bone tumor resection and soft tissues reconstruction from April 2007 to April 2014 were enrolled. Based on histological types, tumor stages and surgical procedures, the effects of artificial prosthesis replacement and soft tissue reconstruction on prognosis and shoulder joint function were evaluated.
 All patients were followed up for 8 to 96 months (average time: 58.9 months). Among 11 patients with primary malignant tumor, 5 died of tumor recurrence or metastasis, and 6 showed tumor-free survival for 24 to 91 months (average time: 54.83 months). The 6 patients with aggressive benign tumors survived for 39 to 96 months, with an average of 72.33 months. The shoulder joint function of 17 patients recovered to 64.88% of normal. There were significant differences in the shoulder joint function between the patients who underwent half shoulder replacement and those who underwent total shoulder replacement (56.25% vs 72.56%, Pshoulder joint function between the patients who underwent Type I A excision (retention of abductor muscles and rotator cuff) and those who underwent Type I B excision (68.75% vs 61.44%, Pshoulder joint function is associated with the methods of prosthesis replacement and soft tissue resection.

  4. Method to measure tone of axial and proximal muscle.

    Science.gov (United States)

    Gurfinkel, Victor S; Cacciatore, Timothy W; Cordo, Paul J; Horak, Fay B

    2011-12-14

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention.

  5. Method to Measure Tone of Axial and Proximal Muscle

    Science.gov (United States)

    Gurfinkel, Victor S.; Cacciatore, Timothy W.; Cordo, Paul J.; Horak, Fay B.

    2011-01-01

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs1, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention. PMID:22214974

  6. AN EFFICIENT SEGMENTATION ALGORITHM FOR ENTITY INTERACTION

    Directory of Open Access Journals (Sweden)

    Eugene Ch'ng

    2009-04-01

    Full Text Available The inventorying of biological diversity and studies in biocomplexity require the management of large electronic datasets of organisms. While species inventory has adopted structured electronic databases for some time, the computer modelling of the functional interactions between biological entities at all levels of life is still in the stage of development. One of the challenges for this type of modelling is the biotic interactions that occur between large datasets of entities represented as computer algorithms. In real-time simulation that models the biotic interactions of large population datasets, the use of computational processing time could be extensive. One way of increasing the efficiency of such simulation is to partition the landscape so that entities need only traverse its local space for entities that falls within the interaction proximity. This article presents an efficient segmentation algorithm for biotic interactions for research related to the modelling and simulation of biological systems.

  7. Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

    Directory of Open Access Journals (Sweden)

    Minghua Xu

    2014-01-01

    Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

  8. Multi-segment coordination: fatigue effects.

    Science.gov (United States)

    Rodacki, A L; Fowler, N E; Bennett, S J

    2001-07-01

    The aim of this study was to investigate the segmental coordination of vertical jumps under fatigue. Twelve subjects performed maximal countermovement jumps with and without fatigue, which was imposed by maximal continuous jumps in place until their maximal jump height corresponded to 70% of the nonfatigued condition. Video, ground reaction forces, and electromyographic signals were recorded to analyze the segmental coordination of countermovement jumps before (CMJ1) and after (CMJ2) fatigue. The magnitude of joint extension initiation, peak joint angular velocity, and peak net power around the ankle, knee, and hip joints and their respective times were determined. CMJ2 was characterized by a longer contact time, which was accompanied with an earlier movement initiation and several differences (P coordination. When the movement duration was normalized with respect to the contact phase duration, the differences between CMJ1 and CMJ2 were not sustained. A consistent pattern was indicated, in which the segmental coordination did not differ between jump conditions. When the magnitude of the muscle activation was set aside, a remarkably consistent muscle activation time was noticed between conditions. It was indicated that countermovement jumps were performed with a consistent well-timed motion of the segments. A "common drive," which acts without the knowledge of the muscle properties, was suggested as mediating and controlling the muscle activation timing between agonist-antagonist muscle pairs.

  9. The effect of posterior polyester tethers on the biomechanics of proximal junctional kyphosis: a finite element analysis.

    Science.gov (United States)

    Bess, Shay; Harris, Jeffrey E; Turner, Alexander W L; LaFage, Virginie; Smith, Justin S; Shaffrey, Christopher I; Schwab, Frank J; Haid, Regis W

    2017-01-01

    OBJECTIVE Proximal junctional kyphosis (PJK) remains problematic following multilevel instrumented spine surgery. Previous biomechanical studies indicate that providing less rigid fixation at the cranial aspect of a long posterior instrumented construct, via transition rods or hooks at the upper instrumented vertebra (UIV), may provide a gradual transition to normal motion and prevent PJK. The purpose of this study was to evaluate the ability of posterior anchored polyethylene tethers to distribute proximal motion segment stiffness in long instrumented spine constructs. METHODS A finite element model of a T7-L5 spine segment was created to evaluate range of motion (ROM), intradiscal pressure, pedicle screw loads, and forces in the posterior ligament complex within and adjacent to the proximal terminus of an instrumented spine construct. Six models were tested: 1) intact spine; 2) bilateral, segmental pedicle screws (PS) at all levels from T-11 through L-5; 3) bilateral pedicle screws from T-12 to L-5 and transverse process hooks (TPH) at T-11 (the UIV); 4) pedicle screws from T-11 to L5 and 1-level tethers from T-10 to T-11 (TE-UIV+1); 5) pedicle screws from T-11 to L-5 and 2-level tethers from T-9 to T-11 (TE-UIV+2); and 6) pedicle screws and 3-level tethers from T-8 to T-11 (TE-UIV+3). RESULTS Proximal-segment range of motion (ROM) for the PS construct increased from 16% at UIV-1 to 91% at UIV. Proximal-segment ROM for the TPH construct increased from 27% at UIV-1 to 92% at UIV. Posterior tether constructs distributed ROM at the UIV and cranial adjacent segments most effectively; ROM for TE-UIV+1 was 14% of the intact model at UIV-1, 76% at UIV, and 98% at UIV+1. ROM for TE-UIV+2 was 10% at UIV-1, 51% at UIV, 69% at UIV+1, and 97% at UIV+2. ROM for TE-UIV+3 was 7% at UIV-1, 33% at UIV, 45% at UIV+1, and 64% at UIV+2. Proximal segment intradiscal pressures, pedicle screw loads, and ligament forces in the posterior ligament complex were progressively reduced with

  10. Early syllabic segmentation of fluent speech by infants acquiring French.

    Science.gov (United States)

    Goyet, Louise; Nishibayashi, Léo-Lyuki; Nazzi, Thierry

    2013-01-01

    Word form segmentation abilities emerge during the first year of life, and it has been proposed that infants initially rely on two types of cues to extract words from fluent speech: Transitional Probabilities (TPs) and rhythmic units. The main goal of the present study was to use the behavioral method of the Headturn Preference Procedure (HPP) to investigate again rhythmic segmentation of syllabic units by French-learning infants at the onset of segmentation abilities (around 8 months) given repeated failure to find syllabic segmentation at such a young age. The second goal was to explore the interaction between the use of TPs and syllabic units for segmentation by French-learning infants. The rationale was that decreasing TP cues around target syllables embedded in bisyllabic words would block bisyllabic word segmentation and facilitate the observation of syllabic segmentation. In Experiments 1 and 2, infants were tested in a condition of moderate TP decrease; no evidence of either syllabic or bisyllabic word segmentation was found. In Experiment 3, infants were tested in a condition of more marked TP decrease, and a novelty syllabic segmentation effect was observed. Therefore, the present study first establishes early syllabic segmentation in French-learning infants, bringing support from a syllable-based language to the proposal that rhythmic units are used at the onset of segmentation abilities. Second, it confirms that French-learning infants are sensitive to TP cues. Third, it demonstrates that they are sensitive to the relative weight of TP and rhythmic cues, explaining why effects of syllabic segmentation are not observed in context of high TPs. These findings are discussed in relation to theories of word segmentation bootstrapping, and the larger debate about statistically- versus prosodically-based accounts of early language acquisition.

  11. Early syllabic segmentation of fluent speech by infants acquiring French.

    Directory of Open Access Journals (Sweden)

    Louise Goyet

    Full Text Available Word form segmentation abilities emerge during the first year of life, and it has been proposed that infants initially rely on two types of cues to extract words from fluent speech: Transitional Probabilities (TPs and rhythmic units. The main goal of the present study was to use the behavioral method of the Headturn Preference Procedure (HPP to investigate again rhythmic segmentation of syllabic units by French-learning infants at the onset of segmentation abilities (around 8 months given repeated failure to find syllabic segmentation at such a young age. The second goal was to explore the interaction between the use of TPs and syllabic units for segmentation by French-learning infants. The rationale was that decreasing TP cues around target syllables embedded in bisyllabic words would block bisyllabic word segmentation and facilitate the observation of syllabic segmentation. In Experiments 1 and 2, infants were tested in a condition of moderate TP decrease; no evidence of either syllabic or bisyllabic word segmentation was found. In Experiment 3, infants were tested in a condition of more marked TP decrease, and a novelty syllabic segmentation effect was observed. Therefore, the present study first establishes early syllabic segmentation in French-learning infants, bringing support from a syllable-based language to the proposal that rhythmic units are used at the onset of segmentation abilities. Second, it confirms that French-learning infants are sensitive to TP cues. Third, it demonstrates that they are sensitive to the relative weight of TP and rhythmic cues, explaining why effects of syllabic segmentation are not observed in context of high TPs. These findings are discussed in relation to theories of word segmentation bootstrapping, and the larger debate about statistically- versus prosodically-based accounts of early language acquisition.

  12. COMPASS-based ureter segmentation in CT urography (CTU)

    Science.gov (United States)

    Zick, David; Hadjiiyski, Lubomir; Chan, Heang-Ping; Cohan, Richard H.; Caoili, Elaine M.; Zhou, Chuan; Wei, Jun

    2014-03-01

    We are developing a computerized system for automated segmentation of ureters in CT urography (CTU), referred to as COmbined Model-guided Path-finding Analysis and Segmentation System (COMPASS). Ureter segmentation is a critical component for computer-aided diagnosis of ureter cancer. A challenge for ureter segmentation is the presence of regions not well opacified with intravenous (IV) contrast. COMPASS consists of three stages: (1) adaptive thresholding and region growing, (2) path-finding and propagation, and (3) edge profile extraction and feature analysis. One hundred fourteen ureters in 74 CTU scans with IV contrast were collected from 74 patient files. On average, the ureters spanned 283 CT slices (range: 116 to 399, median: 301). More than half of the ureters contained malignant or benign lesions and some had ureter wall thickening due to malignancy. A starting point for each of the 114 ureters was selected manually to initialize the tracking by COMPASS. Path-finding and segmentation were guided by the anatomical knowledge of ureters in CTU. The segmentation performance was quantitatively assessed by estimating the percentage of the length that was successfully tracked and segmented for each ureter. Of the 114 ureters, 110 (96%) were segmented completely (100%), 111 (97%) were segmented through at least 70% of its length, and 113 (99%) were segmented at least 50%. In comparison, using our previous method, 79 (69%) ureters were segmented completely (100%), 92 (81%) were segmented through at least 70% of its length, and 98 (86%) were segmented at least 50%. COMPASS improved significantly the ureter tracking, including regions across ureter lesions, wall thickening and the narrowing of the lumen.

  13. Computerized segmentation of ureters in CT urography (CTU) using COMPASS

    Science.gov (United States)

    Hadjiiski, Lubomir M.; Chan, Heang-Ping; Niland, Luke; Cohan, Richard H.; Caoili, Elaine M.; Zhou, Chuan; Wei, Jun

    2013-03-01

    We are developing a computerized system for automated segmentation of ureters on CTU, as a critical component for computer-aided diagnosis of ureter cancer. A challenge for ureter segmentation is the presence of regions not well opacified with intravenous (IV) contrast. We propose a COmbined Model-guided Path-finding Analysis and Segmentation System (COMPASS) to track the ureters in CTU. COMPASS consists of three stages: (1) adaptive thresholding and region growing, (2) edge profile extraction and feature analysis, and (3) path-finding and propagation. 114 ureters, filled with IV contrast material, on 74 CTU scans from 74 patients were segmented. On average the ureter occupied 286 CT slices (range:164 to 399, median:301). More than half of the ureters contained malignant or benign lesions and some had ureter wall thickening due to malignancy. A starting point for each of the 114 ureters was selected manually, which served as an input to the COMPASS, to initialize the tracking. The path-finding and segmentation are guided by anatomical knowledge of the ureters in CTU. The segmentation performance was quantitatively assessed by estimating the percentage of the length that was successfully tracked and segmented for each ureter. Of the 114 ureters, 75 (66%) were segmented completely (100%), 99 (87%) were segmented through at least 70% of its length, and 104 (91%) were segmented at least 50%. Previously, without the model-guided approach, 61 (54%) ureters were segmented completely (100%), 80 (70%) were segmented through at least 70% of its length, and 96 (84%) were segmented at least 50%. COMPASS improved the ureter tracking, including regions across ureter lesions, wall thickening and the narrowing of the lumen.

  14. Market segmentation: Venezuelan ADRs

    Directory of Open Access Journals (Sweden)

    Urbi Garay

    2012-12-01

    Full Text Available The control on foreign exchange imposed by Venezuela in 2003 constitute a natural experiment that allows researchers to observe the effects of exchange controls on stock market segmentation. This paper provides empirical evidence that although the Venezuelan capital market as a whole was highly segmented before the controls were imposed, the shares in the firm CANTV were, through their American Depositary Receipts (ADRs, partially integrated with the global market. Following the imposition of the exchange controls this integration was lost. Research also documents the spectacular and apparently contradictory rise experienced by the Caracas Stock Exchange during the serious economic crisis of 2003. It is argued that, as it happened in Argentina in 2002, the rise in share prices occurred because the depreciation of the Bolívar in the parallel currency market increased the local price of the stocks that had associated ADRs, which were negotiated in dollars.

  15. The Life Saving Effects of Hospital Proximity

    DEFF Research Database (Denmark)

    Bertoli, Paola; Grembi, Veronica

    We assess the lifesaving effect of hospital proximity using data on fatality rates of road-traffic accidents. While most of the literature on this topic is based on changes in distance to the nearest hospital triggered by hospital closures and use OLS estimates, our identification comes from......) increases the fatality rate by 13.84% on the sample average. This is equal to a 0.92 additional death per every 100 accidents. We show that OLS estimates provide a downward biased measure of the real effect of hospital proximity because they do not fully solve spatial sorting problems. Proximity matters...

  16. Segmentation of myocardium from cardiac MR images using a novel dynamic programming based segmentation method.

    Science.gov (United States)

    Qian, Xiaohua; Lin, Yuan; Zhao, Yue; Wang, Jing; Liu, Jing; Zhuang, Xiahai

    2015-03-01

    Myocardium segmentation in cardiac magnetic resonance (MR) images plays a vital role in clinical diagnosis of the cardiovascular diseases. Because of the low contrast and large variation in intensity and shapes, myocardium segmentation has been a challenging task. A dynamic programming (DP) based segmentation method, incorporating the likelihood and shape information of the myocardium, is developed for segmenting myocardium in cardiac MR images. The endocardium, i.e., the left ventricle blood cavity, is segmented for initialization, and then the optimal epicardium contour is determined using the polar-transformed image and DP scheme. In the DP segmentation scheme, three techniques are proposed to improve the segmentation performance: (1) the likelihood image of the myocardium is constructed to define the external cost in the DP, thus the cost function incorporates prior probability estimation; (2) the adaptive search range is introduced to determine the polar-transformed image, thereby excluding irrelevant tissues; (3) the connectivity constrained DP algorithm is developed to obtain an optimal closed contour. Four metrics, including the Dice metric (Dice), root mean squared error (RMSE), reliability, and correlation coefficient, are used to assess the segmentation accuracy. The authors evaluated the performance of the proposed method on a private dataset and the MICCAI 2009 challenge dataset. The authors also explored the effects of the three new techniques of the DP scheme in the proposed method. For the qualitative evaluation, the segmentation results of the proposed method were clinically acceptable. For the quantitative evaluation, the mean (Dice) for the endocardium and epicardium was 0.892 and 0.927, respectively; the mean RMSE was 2.30 mm for the endocardium and 2.39 mm for the epicardium. In addition, the three new techniques in the proposed DP scheme, i.e., the likelihood image of the myocardium, the adaptive search range, and the connectivity constrained

  17. Labor market segmentation

    OpenAIRE

    Berndt, Christian

    2017-01-01

    Labor market segmentation theories arose as an alternative to neoclassical notions of labor and labor markets in the 1970s. After briefly revisiting the strengths and the weaknesses of this approach, the article discusses more recent developments around the question of difference and diversity in labor markets, directing attention to three key developments associated with the rise of neoliberal capitalism: (i) the formation of entrepreneurial subjectivities and the treatment of labor as a div...

  18. Segmental Neurofibromatosis with Angiolipomas

    Directory of Open Access Journals (Sweden)

    Kamlender Singh

    1986-01-01

    Full Text Available A 28 year old male had right axillary freckling, a few cafe-aulait macules and numerous freckles over the right upper half of his body involving the -scapular region, shoulder, chest wall, upper arm and proximal half of the forearm Numerous, bilateral subcutaneous nodules which could possibly be dismissed clinically as subcutaneous nodules of neurofibromatosis, proved to be angiolipomas histopathologically. It is suggested that in the cal molluscum fibrosum, histopathology of subcutaneous nodules should always be resorted to in suspected cases of Neurofibromatosis even when there are suggestive pigmentary changes.

  19. A Cooperative Learning-Based Clustering Approach to Lip Segmentation Without Knowing Segment Number.

    Science.gov (United States)

    Cheung, Yiu-Ming; Li, Meng; Peng, Qinmu; Chen, C L Philip

    2017-01-01

    It is usually hard to predetermine the true number of segments in lip segmentation. This paper, therefore, presents a clustering-based approach to lip segmentation without knowing the true segment number. The objective function in the proposed approach is a variant of the partition entropy (PE) and features that the coincident cluster centroids in pattern space can be equivalently substituted by one centroid with the function value unchanged. It is shown that the minimum of the proposed objective function can be reached provided that: 1) the number of positions occupied by cluster centroids in pattern space is equal to the true number of clusters and 2) these positions are coincident with the optimal cluster centroids obtained under PE criterion. In implementation, we first randomly initialize the clusters provided that the number of clusters is greater than or equal to the ground truth. Then, an iterative algorithm is utilized to minimize the proposed objective function. For each iterative step, not only is the winner, i.e., the centroid with the maximum membership degree, updated to adapt to the corresponding input data, but also the other centroids are adjusted with a specific cooperation strength, so that they are each close to the winner. Subsequently, the initial overpartition will be gradually faded out with the redundant centroids superposed over the convergence of the algorithm. Based upon the proposed algorithm, we present a lip segmentation scheme. Empirical studies have shown its efficacy in comparison with the existing methods.

  20. Spinal segmental dysgenesis CASE SERIES

    African Journals Online (AJOL)

    Spinal segmental dysgenesis is a rare congenital spinal abnormality seen in neonates and infants, in which a segment of the spine and spinal cord fails to develop normally. The condition is segmental in nature, with vertebrae above and below the malformation. It is commonly associated with various abnormalities that ...

  1. Market Segmentation for Information Services.

    Science.gov (United States)

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  2. Segmenting the Adult Education Market.

    Science.gov (United States)

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  3. Comparison of intravascular ultrasound and angiographic assessement of coronary reference segment size in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Mintz, Gary S

    2008-01-01

    During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used...... to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden...... diameter was 1.56 +/- 0.55 mm. The mean difference between the IVUS reference lumen diameter and angiographic reference lumen diameter was 0.18 +/- 0.44 mm. Plaque burden in the reference segment correlated inversely with the difference between IVUS and quantitative coronary angiographic reference lumen...

  4. Caries status and proximal lesion behaviour during a 6-year period in young adult Danes: an epidemiological investigation

    DEFF Research Database (Denmark)

    Martignon, Stefania; Chavarría, Nathaly; Ekstrand, Kim

    2009-01-01

    Studies have indicated that many initial proximal caries lesions progress and are eventually restored even if the patients have been under comprehensive preventive programmes. The objectives of the study were (1) to describe the 1996-year baseline caries status of male Danish conscripts and (2......-surface caries and restoration patterns. After 6 years, the behaviour of proximal lesions was studied in 73 of these subjects, and oral health habits were assessed through a questionnaire. Mean number of filled surfaces was 7.5, of which 23% were posterior proximal. Radiographically, the mean number of proximal......) to assess their early proximal lesions 6-year behaviour. In 1996, all 20-year-old conscripts at Central Barrack Birkerød (n = 115) went through an oral examination, including visual surface-level fillings' recording and a radiographic examination with bitewing radiographs that assessed the proximal...

  5. Proximity and Collaboration in European Nanotechnology

    NARCIS (Netherlands)

    Cunningham, S.W.; Werker, C.

    2011-01-01

    Collaborations are particularly important for the development and deployment of technology. We analyze the influence of organizational, technological and geographical proximity on European nanotechnology collaborations with the help of a publication dataset and additional geographical information.

  6. Promoting proximal formative assessment with relational discourse

    Science.gov (United States)

    Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

    2012-02-01

    The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

  7. Ammonia transport in the proximal tubule.

    Science.gov (United States)

    Hamm, L L; Simon, E E

    1990-01-01

    The transport of ammonia in the proximal tubule is a complex interaction of a number of processes. Ammonia transport in the proximal tubule is clearly bidirectional; ammonia is secreted into the early proximal tubule lumen, but later in the proximal tubule, efflux out of the lumen may result in net ammonia reabsorption. Two mechanisms of ammonia transport have clearly been established: NH3 diffusion and NH4+ transport on the Na(+)-H+ exchanger. The relative contribution of these pathways to ammonia transport is still unsettled. Other pathways for ammonia transport, particularly NH4+ efflux out of the lumen, may be important as well. A variety of factors may modulate ammonia transport: plasma, cell and luminal pH, luminal flow rate, luminal potassium, and angiotensin II. Each of these factors also alters ammonia production rates and in most circumstances, ammonia transport appears to follow ammonia production rates.

  8. Proximate composition and cholesterol concentrations of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    DWB) for raw and fried samples, respectively, but decreased to 295.20 ... Key words: Rhynchophorus phoenicis, Oryctes monoceros, proximate composition, cholesterol, heat treatment. INTRODUCTION. Insects have played ...

  9. COMPARATIVE ANALYSIS OF PROXIMATE COMPOSITIONS OF ...

    African Journals Online (AJOL)

    Babatunde Emmanuel

    2011-10-06

    Oct 6, 2011 ... Fish allows for protein improved nutrition in that it has a high biological value in terms of high ... marine algae upon which the fish feed [11]. ... Proximate composition of catfish Clarias gariepinus and Tarpon atlanticus were.

  10. Correction tool for Active Shape Model based lumbar muscle segmentation.

    Science.gov (United States)

    Valenzuela, Waldo; Ferguson, Stephen J; Ignasiak, Dominika; Diserens, Gaelle; Vermathen, Peter; Boesch, Chris; Reyes, Mauricio

    2015-08-01

    In the clinical environment, accuracy and speed of the image segmentation process plays a key role in the analysis of pathological regions. Despite advances in anatomic image segmentation, time-effective correction tools are commonly needed to improve segmentation results. Therefore, these tools must provide faster corrections with a low number of interactions, and a user-independent solution. In this work we present a new interactive correction method for correcting the image segmentation. Given an initial segmentation and the original image, our tool provides a 2D/3D environment, that enables 3D shape correction through simple 2D interactions. Our scheme is based on direct manipulation of free form deformation adapted to a 2D environment. This approach enables an intuitive and natural correction of 3D segmentation results. The developed method has been implemented into a software tool and has been evaluated for the task of lumbar muscle segmentation from Magnetic Resonance Images. Experimental results show that full segmentation correction could be performed within an average correction time of 6±4 minutes and an average of 68±37 number of interactions, while maintaining the quality of the final segmentation result within an average Dice coefficient of 0.92±0.03.

  11. Phytochemical screening, proximate analysis and acute toxicity ...

    African Journals Online (AJOL)

    Phytochemical screening, proximate analysis and acute toxicity studies were carried out on the leaf extract of Cola lepidota, in accordance with established standard procedures. The proximate analysis reveals a moisture content of 27.43 ± 3.11 % w/w, total ash value 9.32 ± 0.27 % w/w, acid insoluble ash 3.12 ± 1.05 % w/w ...

  12. Proximate, Mineral and Phytochemical Composition of Dioscorea ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Proximate, mineral and phytochemical composition of Dioscorea dumetorum tubers was investigated using standard procedures. Proximate analysis included in g% dry weight: crude protein (6.44 ± 0.32), crude fat (0.75 ± 0.04), crude fibre (15.00 ± 0.56), total ash. (3.45 ± 0.20) and a moisture content of 70.04 ...

  13. Painful Spastic Hip Dislocation: Proximal Femoral Resection

    OpenAIRE

    Albiñana, Javier; Gonzalez-Moran, Gaspar

    2002-01-01

    The dislocated hip in a non-ambulatory child with spastic paresis tends to be a painful interference to sleep, sitting upright, and perineal care. Proximal femoral resection-interposition arthroplasty is one method of treatment for this condition. We reviewed eight hips, two bilateral cases, with a mean follow-up of 30 months. Clinical improvement was observed in all except one case, with respect to pain relief and sitting tolerance. Some proximal migration was observed in three cases, despit...

  14. Comparison of electrogenic glucose transport processes and permeability between proximal and distal jejunum of laying hens.

    Science.gov (United States)

    Metzler-Zebeli, B U; Hollmann, M; Aschenbach, J R; Zebeli, Q

    2017-06-01

    1. The current objective was to assess (1) differences in mucosal transepithelial short-circuit current (Isc) and tissue conductance (GT), (2) the effect of a glucose stimulus and (3) epithelial paracellular permeability in the proximal and distal jejunum of laying hens. 2. Proximal and distal jejunal segments used in the Ussing chambers were collected at 9 ± 0.5 and 73 ± 3.4% (SEM) of jejunal length, respectively. The proximal jejunal mucosa showed a small negative Isc (-1.3 µA/cm(2)), whereas the distal jejunum had a higher Isc (32.9 µA/cm(2)). Similarly, GT was 2.5-fold greater in the distal compared to the proximal jejunum. 3. Increased paracellular permeability in the distal jejunum was displayed as demonstrated by a 5-fold higher mucosal to serosal flux of fluorescein isothiocyanate and horseradish peroxidase, representing molecules of low and high molecular weight, respectively. 4. Addition of glucose to the mucosal side (5 mmol/l, final concentration in the chamber) to stimulate an absorptive effect caused 3-fold greater GT in the distal compared to the proximal jejunum. 5. In conclusion, the present results supported site-specific electrogenic transport processes for the jejunal mucosa of laying hens. Therefore, precise description of the jejunal site may contribute to an improved comparability of electrophysiological data.

  15. Management of impacted proximal ureteral stone: Extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy

    Directory of Open Access Journals (Sweden)

    Mostafa Khalil

    2013-01-01

    Conclusion: Both procedures can be used effectively and safely as a primary treatment for impacted stone in the proximal ureter; however, the URSL has a significantly higher initial stone-free rate and lower re-treatment rate.

  16. Proximity sensor system development. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Haley, D.C. [Oak Ridge National Lab., TN (United States); Pigoski, T.M. [Merrit Systems, Inc. (United States)

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors.

  17. Transformations through Proximity Flying: A Phenomenological Investigation

    Science.gov (United States)

    Holmbom, Maria; Brymer, Eric; Schweitzer, Robert D.

    2017-01-01

    Participation in extreme sports has been linked to personal transformations in everyday life. Descriptions of lived experience resulting from transformative experiences are limited. Proximity flying, a relatively new discipline involving BASE jumping with a wingsuit where participants fly close to solid structures, is arguably one of the most extreme of extreme sports. The aim of this paper, part of a larger phenomenological study on the lived experience of proximity flying, is to explicate the ways in which participating in proximity flying influences the everyday lives of participants. Interpretative phenomenological analysis was used to explicate the lived experience of six proximity pilots. An analysis of interview transcripts revealed three significant themes describing the lived experience of participants. First, experiences of change were described as positive and skills developed through proximity flying were transferable into everyday life. Second, transformative experiences were considered fundamental to participants’ perspectives on life. Third, experience of transformation influenced their sense of personal identity and facilitated flourishing in other aspects of everyday life. Participants were clear that their experiences in proximity flying facilitated a profound process of transformation which manifest as changes in everyday capabilities and behaviors, values and sense of identity. PMID:29104552

  18. Distraction lengthening of the proximal phalanx in distal thumb amputations.

    Science.gov (United States)

    Cansü, Eren; Ünal, Mehmet Bekir; Parmaksızoğlu, Fatih; Gürcan, Serkan

    2015-01-01

    Thumb amputation is a major cause of hand dysfunction, and the treatment for distal thumb amputations remains controversial. Although finger reconstruction methods using distraction lengthening are known to restore finger length and function, we found no reports in the literature regarding phalangeal lengthening in thumb amputations. We aimed to evaluate proximal phalangeal lengthening in thumb amputations at or near the interphalangeal (IP) joint. We retrospectively evaluated patients who had undergone distraction lengthening of the proximal phalanx of the thumb. All patients underwent osteotomy, either during the initial procedure or as a second-stage procedure. Distraction began 10 days after osteotomy with the use of an external fixator that remained in place until ossification of the gap occurred without bone grafting. Patients were evaluated using the QuickDASH score. Fourteen patients with a mean age of 27 years and a mean follow-up period of 7 years were enrolled. The mean phalangeal lengthening achieved was 20 mm. Ossification occurred at all distraction sites, and the fixators were maintained for a mean of 85 days. The mean healing index was 42.5 days/cm. All 14 patients achieved the desired amount of phalangeal lengthening without major complications such as nonunion, premature union, or gross infection. For reconstruction in cases of distal thumb amputations, distraction lengthening of the proximal phalanx can be used to improve absolute length, web space, and grip distance. The technique is safe and effective, improves functionality/cosmesis, and offers a low complication risk.

  19. Treatment of proximal segment stenoses of vertebral arteries with baloon expandable silicon carbide coated stents

    Directory of Open Access Journals (Sweden)

    Šeruga Tomaž

    2013-01-01

    Conclusions: Stenting of the vertebral arteries can significantly improve hemodynamic conditions in the posterior circulation and prevent recurrent transient ischemic attacks and worsening of vertebro-basilar symptoms. So far, less than twenty studies have been published on the stenting of vertebral arteries worldwide. Randomized larger prospective trials are needed to confirm the benefit of endovascular treatment of vertebral artery stenosis, also by use of drugeluting stents.

  20. Proximal tibial epiphyseal intraosseous schwannoma: a rare entity.

    Science.gov (United States)

    Meyer, Alain; Sailhan, Frédéric; Coulomb, Aurore; Thevenin-Lemoine, Camille; Mary, Pierre; Ducou-Lepointe, Hubert; Damsin, Jean-Paul

    2008-01-01

    Schwannoma is a benign nerve sheath tumor most commonly located in the soft tissue. Occasionally, schwannomas involve osseous structures. The rarity of osseous involvement leads to omission of schwannoma from the initial differential diagnosis in the majority of cases. Intraosseous schwannomas arising in children have not been reported. We present the case of a schwannoma affecting the proximal tibial epiphysis in a growing child. Intraosseous schwannomas should be included in the differential diagnosis of lytic epiphyseal benign-appearing bone lesions in children. Its radiographic characteristics mimic those of benign chondroblastoma.

  1. Acute tumor lysis syndrome after proximal splenic artery embolization

    Directory of Open Access Journals (Sweden)

    Jason T. Salsamendi

    2016-06-01

    Full Text Available Preoperative splenic artery embolization for massive splenomegaly has been shown to reduce intraoperative hemorrhage during splenectomy. We describe a case of tumor lysis syndrome after proximal splenic artery embolization in a patient with advanced mantle cell lymphoma and splenic involvement. The patient presented initially with hyperkalemia two days after embolization that worsened during splenectomy. He was stabilized, but developed laboratory tumor lysis syndrome with renal failure and expired. High clinical suspicion of tumor lysis syndrome in this setting is advised. Treatment must be started early to avoid serious renal injury and death. Lastly, same day splenectomy and embolization should be considered to decrease the likelihood of developing tumor lysis syndrome.

  2. Validation tools for image segmentation

    Science.gov (United States)

    Padfield, Dirk; Ross, James

    2009-02-01

    A large variety of image analysis tasks require the segmentation of various regions in an image. For example, segmentation is required to generate accurate models of brain pathology that are important components of modern diagnosis and therapy. While the manual delineation of such structures gives accurate information, the automatic segmentation of regions such as the brain and tumors from such images greatly enhances the speed and repeatability of quantifying such structures. The ubiquitous need for such algorithms has lead to a wide range of image segmentation algorithms with various assumptions, parameters, and robustness. The evaluation of such algorithms is an important step in determining their effectiveness. Therefore, rather than developing new segmentation algorithms, we here describe validation methods for segmentation algorithms. Using similarity metrics comparing the automatic to manual segmentations, we demonstrate methods for optimizing the parameter settings for individual cases and across a collection of datasets using the Design of Experiment framework. We then employ statistical analysis methods to compare the effectiveness of various algorithms. We investigate several region-growing algorithms from the Insight Toolkit and compare their accuracy to that of a separate statistical segmentation algorithm. The segmentation algorithms are used with their optimized parameters to automatically segment the brain and tumor regions in MRI images of 10 patients. The validation tools indicate that none of the ITK algorithms studied are able to outperform with statistical significance the statistical segmentation algorithm although they perform reasonably well considering their simplicity.

  3. FRAMEWORK FOR COMPARING SEGMENTATION ALGORITHMS

    Directory of Open Access Journals (Sweden)

    G. Sithole

    2015-05-01

    Full Text Available The notion of a ‘Best’ segmentation does not exist. A segmentation algorithm is chosen based on the features it yields, the properties of the segments (point sets it generates, and the complexity of its algorithm. The segmentation is then assessed based on a variety of metrics such as homogeneity, heterogeneity, fragmentation, etc. Even after an algorithm is chosen its performance is still uncertain because the landscape/scenarios represented in a point cloud have a strong influence on the eventual segmentation. Thus selecting an appropriate segmentation algorithm is a process of trial and error. Automating the selection of segmentation algorithms and their parameters first requires methods to evaluate segmentations. Three common approaches for evaluating segmentation algorithms are ‘goodness methods’, ‘discrepancy methods’ and ‘benchmarks’. Benchmarks are considered the most comprehensive method of evaluation. This paper shortcomings in current benchmark methods are identified and a framework is proposed that permits both a visual and numerical evaluation of segmentations for different algorithms, algorithm parameters and evaluation metrics. The concept of the framework is demonstrated on a real point cloud. Current results are promising and suggest that it can be used to predict the performance of segmentation algorithms.

  4. Weighted entropy for segmentation evaluation

    Science.gov (United States)

    Khan, Jesmin F.; Bhuiyan, Sharif M.

    2014-04-01

    In many image, video and computer vision systems the image segmentation is an essential part. Significant research has been done in image segmentation and a number of quantitative evaluation methods have already been proposed in the literature. However, often the segmentation evaluation is subjective that means it has been done visually or qualitatively. A segmentation evaluation method based on entropy is proposed in this work which is objective and simple to implement. A weighted self and mutual entropy are proposed to measure the dissimilarity of the pixels among the segmented regions and the similarity within a region. This evaluation technique gives a score that can be used to compare different segmentation algorithms for the same image, or to compare the segmentation results of a given algorithm with different images, or to find the best suited values of the parameters of a segmentation algorithm for a given image. The simulation results show that the proposed method can identify over-segmentation, under-segmentation, and the good segmentation.

  5. Segmental neurofibromatosis of face.

    Science.gov (United States)

    Agarwal, Anuja; Thappa, Devinder M; Jayanthi, S; Shivaswamy, K N

    2005-12-01

    A 38-year-old man presented with asymptomatic skin lesions over the left side of the face of 5-years duration. He had multiple discrete soft-to-firm papules and nodules on the left side of the face along the distribution of the mandibular division of the trigeminal nerve. Histopathology examination of one of the nodules (face) showed a non-encapsulated tumor of the dermis with normal overlying epidermis. The tumor consisted of loosely spaced spindle cells and wavy collagenous strands in a clear matrix. These features were consistent with our clinical diagnosis of segmental neurofibromatosis. This case is reported for its rarity and typical manifestations.

  6. Road Map Inference: A Segmentation and Grouping Framework

    Directory of Open Access Journals (Sweden)

    Jia Qiu

    2016-07-01

    Full Text Available We propose a new segmentation and grouping framework for road map inference from GPS traces. We first present a progressive Density-Based Spatial Clustering of Application with Noise (DBSCAN algorithm with an orientation constraint to partition the whole point set of the traces into clusters that represent road segments. A new point cluster grouping algorithm, according to the topological relationship and spatial proximity of the point clusters to recover the road network, is then developed. After generating the point clusters, the robust Locally-Weighted Scatterplot Smooth (Lowess method is used to extract their centerlines. We then propose to build the topological relationship of the centerlines by a Hidden Markov Model (HMM-based map matching algorithm; and to assess whether the spatial proximity between point clusters by assuming the distances from the points to the centerline comply with a Gaussian distribution. Finally, the point clusters are grouped according to their topological relationship and spatial proximity to form strokes for recovering the road map. Experimental results show that our algorithm is robust to noise and varied sampling rates. The generated road maps show high geometric accuracy.

  7. Treatment of three- and four-part proximal humeral fractures with locking proximal humerus plate.

    Science.gov (United States)

    Sun, Jing-Cheng; Li, Yu-Lin; Ning, Guang-Zhi; Wu, Qiang; Feng, Shi-Qing

    2013-08-01

    The purpose of this study was to evaluate the effectiveness and complications of the locking proximal humerus plate to treat proximal humerus fractures. A retrospective clinical trial. Department of Orthopaedics, Tianjin Medical University General Hospital. Sixty-eight consecutive patients with three- or four-part fractures of the proximal humerus were treated with locking proximal humerus plates. The deltopectoral anterolateral acromial approach was used to the proximal humerus; open reduction and locking proximal humerus plate were applied. Constant Score was used to measure the shoulder functional recovery, and Visual Analog Scale (VAS) was used to measure subjective evaluation of pain. The radiology was observed. After average 26.7 months, the average Constant Score was 72.6 ± 13.2 points and the average VAS was 1.2 ± 0.8 points. All the complications such as screw perforation into the glenohumeral joint, screws loosening, soft tissue infections, avascular necrosis and delayed union occurred in eight cases (11.8 %). The effectiveness of the locking proximal humerus plate was similar to other published literatures on treating fractures of the proximal humerus; however, a lower complications rate in short follow-up time was observed in this study. It may potentially provide a favorable option for treating three- or four-part fractures of the proximal humerus. Dealing with each particular fracture pattern, surgeons should have a decision of appropriate way to internal fixation.

  8. Fast Appearance Modeling for Automatic Primary Video Object Segmentation.

    Science.gov (United States)

    Yang, Jiong; Price, Brian; Shen, Xiaohui; Lin, Zhe; Yuan, Junsong

    2016-02-01

    Automatic segmentation of the primary object in a video clip is a challenging problem as there is no prior knowledge of the primary object. Most existing techniques thus adapt an iterative approach for foreground and background appearance modeling, i.e., fix the appearance model while optimizing the segmentation and fix the segmentation while optimizing the appearance model. However, these approaches may rely on good initialization and can be easily trapped in local optimal. In addition, they are usually time consuming for analyzing videos. To address these limitations, we propose a novel and efficient appearance modeling technique for automatic primary video object segmentation in the Markov random field (MRF) framework. It embeds the appearance constraint as auxiliary nodes and edges in the MRF structure, and can optimize both the segmentation and appearance model parameters simultaneously in one graph cut. The extensive experimental evaluations validate the superiority of the proposed approach over the state-of-the-art methods, in both efficiency and effectiveness.

  9. Axillary Artery Injury Associated with Proximal Humerus Fracture: A Report of 6 Cases

    Directory of Open Access Journals (Sweden)

    Rinne M. Peters

    2017-01-01

    Full Text Available Proximal humerus fractures are common, but associated injury of the axillary artery is uncommon. The majority of published blunt traumatic axillary artery injuries are associated with anterior glenohumeral dislocation; a few are associated with isolated proximal humerus fractures or fracture-dislocation. Experience within our institution demonstrates that axillary artery injury is often unrecognized on initial presentation owing to palpable peripheral pulses and the absence of ischemia and places the hand at risk of necrosis and amputation if there is prolonged ischemia and the forearm at risk of compartment syndrome after revascularization. Accurate physical examination in combination with a low threshold for Doppler examination or angiography can establish the diagnosis of axillary artery injury. We present 6 cases of axillary artery injury associated with proximal humerus fractures in order to highlight the potential for this vascular injury in the setting of a proximal humerus fracture.

  10. A toolbox for multiple sclerosis lesion segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Roura, Eloy; Oliver, Arnau; Valverde, Sergi; Llado, Xavier [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Cabezas, Mariano; Pareto, Deborah; Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Dept. of Radiology, Barcelona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain)

    2015-10-15

    Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities. (orig.)

  11. Combined morphological-spectral unsupervised image segmentation.

    Science.gov (United States)

    O'Callaghan, Robert J; Bull, David R

    2005-01-01

    The goal of segmentation is to partition an image into disjoint regions, in a manner consistent with human perception of the content. For unsupervised segmentation of general images, however, there is the competing requirement not to make prior assumptions about the scene. Here, a two-stage method for general image segmentation is proposed, which is capable of processing both textured and nontextured objects in a meaningful fashion. The first stage extracts texture features from the subbands of the dual-tree complex wavelet transform. Oriented median filtering is employed, to circumvent the problem of texture feature response at step edges in the image. From the processed feature images, a perceptual gradient function is synthesised, whose watershed transform provides an initial segmentation. The second stage of the algorithm groups together these primitive regions into meaningful objects. To achieve this, a novel spectral clustering technique is proposed, which introduces the weighted mean cut cost function for graph partitioning. The ability of the proposed algorithm to generalize across a variety of image types is demonstrated.

  12. A toolbox for multiple sclerosis lesion segmentation.

    Science.gov (United States)

    Roura, Eloy; Oliver, Arnau; Cabezas, Mariano; Valverde, Sergi; Pareto, Deborah; Vilanova, Joan C; Ramió-Torrentà, Lluís; Rovira, Àlex; Lladó, Xavier

    2015-10-01

    Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities.

  13. Segmented Target Design

    Science.gov (United States)

    Merhi, Abdul Rahman; Frank, Nathan; Gueye, Paul; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    A proposed segmented target would improve decay energy measurements of neutron-unbound nuclei. Experiments like this have been performed at the National Superconducting Cyclotron Laboratory (NSCL) located at Michigan State University. Many different nuclei are produced in such experiments, some of which immediately decay into a charged particle and neutron. The charged particles are bent by a large magnet and measured by a suite of charged particle detectors. The neutrons are measured by the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). With the current target setup, a nucleus in a neutron-unbound state is produced with a radioactive beam impinged upon a beryllium target. The resolution of these measurements is very dependent on the target thickness since the nuclear interaction point is unknown. In a segmented target using alternating layers of silicon detectors and Be-targets, the Be-target in which the nuclear reaction takes place would be determined. Thus the experimental resolution would improve. This poster will describe the improvement over the current target along with the status of the design. Work supported by Augustana College and the National Science Foundation grant #0969173.

  14. Minimally invasive percutaneous plating of proximal humeral shaft fractures with the Proximal Humerus Internal Locking System (PHILOS).

    Science.gov (United States)

    Brunner, Alexander; Thormann, Sebastian; Babst, Reto

    2012-08-01

    This study evaluated our results after minimally invasive percutaneous plating of proximal humeral shaft fractures with the Proximal Humerus Internal Locking System (PHILOS, Synthes, Switzerland). Between 2005 and 2008, 15 patients with unilateral displaced proximal humeral shaft fractures were treated and followed up over a median period of 27 months (range, 12-38 months). The final follow-up included anteroposterior and lateral x-rays, range of shoulder motion, pain by visual analog scale (VAS), the Constant-Murley shoulder score, the Disabilities of Arm, Shoulder and Elbow (DASH) score, and the Short Form 36 (SF36) assessment. No intraoperative or postoperative complications occurred. No secondary fracture displacement or radial neuropathy was observed postoperatively. One patient had open reduction and internal fixation for pseudoarthrosis 16 months after the initial surgery. At the final follow-up, the median range of motion of the operated shoulder was flexion, 145°; extension, 45°; internal rotation, 40°; external rotation, 70°; and abduction, 135°. Median results on outcome assessments were VAS pain score, 0 points; Constant-Murley score, 74 points, representing 87.5% of the median Constant-Murley score of the unaffected shoulder; DASH score, 34 points, and the SF36, 83 points. Minimally invasive percutaneous plating with the PHILOS offers a valid option in the treatment of proximal humeral shaft fractures with comparable rates of nonunion and lower rates of radial neuropathy compared with open procedures. Furthermore, the results indicate that this method is associated with lower rates of wound infection and a shorter stay in the hospital for the patient. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  15. Segmentation of the Infant Food Market

    OpenAIRE

    Hrůzová, Daniela

    2015-01-01

    The theoretical part covers general market segmentation, namely the marketing importance of differences among consumers, the essence of market segmentation, its main conditions and the process of segmentation, which consists of four consecutive phases - defining the market, determining important criteria, uncovering segments and developing segment profiles. The segmentation criteria, segmentation approaches, methods and techniques for the process of market segmentation are also described in t...

  16. Patch-Based Segmentation with Spatial Consistency: Application to MS Lesions in Brain MRI

    OpenAIRE

    Roey Mechrez; Jacob Goldberger; Hayit Greenspan

    2016-01-01

    This paper presents an automatic lesion segmentation method based on similarities between multichannel patches. A patch database is built using training images for which the label maps are known. For each patch in the testing image, k similar patches are retrieved from the database. The matching labels for these k patches are then combined to produce an initial segmentation map for the test case. Finally an iterative patch-based label refinement process based on the initial segmentation map i...

  17. Open segmental fracture of both bone forearm and dislocation of ipsilateral elbow with extruded middle segment radius

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    2013-01-01

    Full Text Available Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child′s mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial. Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture.

  18. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  19. Unified wavelet and Gaussian filtering for segmentation of CT images; application in segmentation of bone in pelvic CT images.

    Science.gov (United States)

    Vasilache, Simina; Ward, Kevin; Cockrell, Charles; Ha, Jonathan; Najarian, Kayvan

    2009-11-03

    The analysis of pelvic CT scans is a crucial step for detecting and assessing the severity of Traumatic Pelvic Injuries. Automating the processing of pelvic CT scans could impact decision accuracy, decrease the time for decision making, and reduce health care cost. This paper discusses a method to automate the segmentation of bone from pelvic CT images. Accurate segmentation of bone is very important for developing an automated assisted-decision support system for Traumatic Pelvic Injury diagnosis and treatment. The automated method for pelvic CT bone segmentation is a hierarchical approach that combines filtering and histogram equalization, for image enhancement, wavelet analysis and automated seeded region growing. Initial results of segmentation are used to identify the region where bone is present and to target histogram equalization towards the specific area. Speckle Reducing Anisotropic Didffusion (SRAD) filter is applied to accentuate the desired features in the region. Automated seeded region growing is performed to refine the initial bone segmentation results. The proposed method automatically processes pelvic CT images and produces accurate segmentation. Bone connectivity is achieved and the contours and sizes of bones are true to the actual contour and size displayed in the original image. Results are promising and show great potential for fracture detection and assessing hemorrhage presence and severity. Preliminary experimental results of the automated method show accurate bone segmentation. The novelty of the method lies in the unique hierarchical combination of image enhancement and segmentation methods that aims at maximizing the advantages of the combined algorithms. The proposed method has the following advantages: it produces accurate bone segmentation with maintaining bone contour and size true to the original image and is suitable for automated bone segmentation from pelvic CT images.

  20. Robotic liver resection including the posterosuperior segments : initial experience

    NARCIS (Netherlands)

    Nota, Carolijn L.M.A.; Molenaar, I. Quintus; van Hillegersberg, Richard; Borel Rinkes, Inne H.M.; Hagendoorn, Jeroen

    2016-01-01

    Background Robot-assisted laparoscopy has been introduced to overcome the limitations of conventional laparoscopy. This technique has potential advantages over laparoscopy, such as increased dexterity, three-dimensional view, and a magnified view of the operative field. Therefore, improved dexterity

  1. Towards fully automatic object detection and segmentation

    Science.gov (United States)

    Schramm, Hauke; Ecabert, Olivier; Peters, Jochen; Philomin, Vasanth; Weese, Juergen

    2006-03-01

    An automatic procedure for detecting and segmenting anatomical objects in 3-D images is necessary for achieving a high level of automation in many medical applications. Since today's segmentation techniques typically rely on user input for initialization, they do not allow for a fully automatic workflow. In this work, the generalized Hough transform is used for detecting anatomical objects with well defined shape in 3-D medical images. This well-known technique has frequently been used for object detection in 2-D images and is known to be robust and reliable. However, its computational and memory requirements are generally huge, especially in case of considering 3-D images and various free transformation parameters. Our approach limits the complexity of the generalized Hough transform to a reasonable amount by (1) using object prior knowledge during the preprocessing in order to suppress unlikely regions in the image, (2) restricting the flexibility of the applied transformation to only scaling and translation, and (3) using a simple shape model which does not cover any inter-individual shape variability. Despite these limitations, the approach is demonstrated to allow for a coarse 3-D delineation of the femur, vertebra and heart in a number of experiments. Additionally it is shown that the quality of the object localization is in nearly all cases sufficient to initialize a successful segmentation using shape constrained deformable models.

  2. Partial differential equations-based segmentation for radiotherapy treatment planning.

    Science.gov (United States)

    Gibou, Frederic; Levy, Doron; Cardenas, Carlos; Liu, Pingyu; Boyer, Arthur

    2005-04-01

    The purpose of this study is to develop automatic algorithms for the segmentation phase of radiotherapy treatment planning. We develop new image processing techniques that are based on solving a partial diferential equation for the evolution of the curve that identifies the segmented organ. The velocity function is based on the piecewise Mumford-Shah functional. Our method incorporates information about the target organ into classical segmentation algorithms. This information, which is given in terms of a three- dimensional wireframe representation of the organ, serves as an initial guess for the segmentation algorithm. We check the performance of the new algorithm on eight data sets of three diferent organs: rectum, bladder, and kidney. The results of the automatic segmentation were compared with a manual seg- mentation of each data set by radiation oncology faculty and residents. The quality of the automatic segmentation was measured with the k-statistics", and with a count of over- and undersegmented frames, and was shown in most cases to be very close to the manual segmentation of the same data. A typical segmentation of an organ with sixty slices takes less than ten seconds on a Pentium IV laptop.

  3. Measurement of cadaver lumbar spine motion segment stiffness.

    Science.gov (United States)

    Brown, Mark D; Holmes, David C; Heiner, Anneliese D

    2002-05-01

    Prospective. To measure lumbar spine motion segment stiffness and relate it to the degree of disc degeneration. The association between the instability of the lumbar spine motion segment and disc degeneration remains unclear. The traditional method for determining motion segment instability at the time of decompressive surgery is a manual test performed by the surgeon. To quantify instability of the lumbar spine, a vertebrae distractor was developed in the authors' laboratory to measure motion segment stiffness by applying a defined load at a constant rate. Lumbar stiffness was measured by subjecting cadaver lumbar spine motion segments to a constant rate flexion-traction load and recording the magnitude of the resistance to distraction versus the range of motion. Disc degeneration was measured by pressure-volume discography and by grading of disc morphology. Motion segment stiffness decreased with the initial stages of disc degeneration and then increased with severe disc degeneration. This measure of motion segment stiffness correlated well with a manual stiffness measure. The observed results follow an accepted hypothesis of motion segment instability associated with disc degeneration.

  4. Lingular segment torsion following a left upper division segmentectomy.

    Science.gov (United States)

    Taira, Naohiro; Kawasaki, Hidenori; Takahara, Sayako; Furugen, Tomonori; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawabata, Tsutomu

    2017-01-01

    Numerous publications regarding lung torsion have reported lobar torsion after lobectomy. On the other hand, torsion of the remaining segment after segmentectomy is extremely rare. We herein report a rare case of lingular segment torsion following a left upper division segmentectomy. A 68-year old female underwent thoracoscopic segmentectomy of the left upper division. She underwent chest radiography immediately after the initial surgery, which revealed complete expansion on the operated side. Routine chest radiograph findings on postoperative day 1 demonstrated atelectasis on the operated side, although she did not have any symptoms. Chest computed tomography was conducted because a follow-up chest radiograph on postoperative day 5 showed no improvement, and she was diagnosed with torsion of the lingular segment. We performed an exploratory thoracotomy. Based on intraoperative findings, the lingular segment was found to have a 90° clockwise torsion along the pedicle axis, although the segment was viable. We straightened the kinked lingular segment and affixed the lingular segment to the left lower lobe. The postoperative course was uneventful. Although lobectomy is the most common cause of lung torsion, physicians should check for lung segment torsion when performing segmentectomy. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Segmentation-DrivenTomographic Reconstruction

    DEFF Research Database (Denmark)

    Kongskov, Rasmus Dalgas

    ), the classical reconstruction methods suffer from their inability to handle limited and/ or corrupted data. Form any analysis tasks computationally demanding segmentation methods are used to automatically segment an object, after using a simple reconstruction method as a first step. In the literature, methods...... such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction...... problem. The tests showed a clear improvement for realistic materials simulations and that the one-stage method was clearly more robust toward noise. The noise-robustness result could be a step toward making this method more applicable for lab-scale experiments. We have introduced a segmentation...

  6. Multispectral satellite imagery segmentation using a simplified JSEG approach

    Science.gov (United States)

    Chen, QiuXiao; Luo, JianCheng; Zhou, ChengHu

    2004-11-01

    It is a big challenge to segment remote sensing images especially multispectral satellite imagery due to their unique features. In consideration of the fact that satellite imagery are playing an increasing important role, we conducted the research on segmentation of such imagery. Since multispectral satellite imagery are more similar to natural color images than to other type of images, it is more likely that studies on natural color images segmentation can be extended to multispectral satellite imagery. The obstacle of applying these studies into multispectral satellite imagery lies into their inefficiency when dealing with the large size of images. Therefore, based on a natural color image segmentation approach - JSEG, we proposed a more efficient one. First, a grid-based cluster initialization approach is proposed to obtain the initial cluster centers, based on which, a fast image quantization approach is implemented. Second, a feature image named J-image to describe local homogeneity is obtained. Then a watershed approach is applied to the J-image, and initial segmentation results are obtained. At last, based on the histogram similarity of each region, a simplified growth merging approach is proposed and the final segmentation results are obtained. By comparing the result of the JSEG approach and the proposed one, we found that the latter is rather efficient and accuracy. Advice on further studies is also presented.

  7. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  8. Segmentation Using Symmetry Deviation

    DEFF Research Database (Denmark)

    Hollensen, Christian; Højgaard, L.; Specht, L.

    2011-01-01

    Purpose: The manual delineation of gross tumour volume(GTV) for radiation therapy for head and neck cancer patients relies in some degree of pathological deviation from normal anatomical symmetry. The purpose of this study is to introduce a novel method for 3-dimensional determination of GTV...... hypopharyngeal cancer patients to find anatomical symmetry and evaluate it against the standard deviation of the normal patients to locate pathologic volumes. Combining the information with an absolute PET threshold of 3 Standard uptake value (SUV) a volume was automatically delineated. The overlap of automated...... segmentations on manual contours was evaluated using concordance index and sensitivity for the hypopharyngeal patients. The resulting concordance index and sensitivity was compared with the result of using a threshold of 3 SUV using a paired t-test. Results: The anatomical and symmetrical atlas was constructed...

  9. Optimally segmented magnetic structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bahl, Christian; Bjørk, Rasmus

    We present a semi-analytical algorithm for magnet design problems, which calculates the optimal way to subdivide a given design region into uniformly magnetized segments.The availability of powerful rare-earth magnetic materials such as Nd-Fe-B has broadened the range of applications of permanent...... is not available.We will illustrate the results for magnet design problems from different areas, such as electric motors/generators (as the example in the picture), beam focusing for particle accelerators and magnetic refrigeration devices....... magnets[1][2]. However, the powerful rare-earth magnets are generally expensive, so both the scientific and industrial communities have devoted a lot of effort into developing suitable design methods. Even so, many magnet optimization algorithms either are based on heuristic approaches[3...

  10. Industrial Computed Tomography using Proximal Algorithm

    KAUST Repository

    Zang, Guangming

    2016-04-14

    In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using fewer projections. We compare our framework to state-of-the-art methods and existing popular software tomography reconstruction packages, on both synthetic and real datasets, and show superior reconstruction quality, especially from noisy data and a small number of projections.

  11. Correlation between social proximity and mobility similarity.

    Science.gov (United States)

    Fan, Chao; Liu, Yiding; Huang, Junming; Rong, Zhihai; Zhou, Tao

    2017-09-20

    Human behaviors exhibit ubiquitous correlations in many aspects, such as individual and collective levels, temporal and spatial dimensions, content, social and geographical layers. With rich Internet data of online behaviors becoming available, it attracts academic interests to explore human mobility similarity from the perspective of social network proximity. Existent analysis shows a strong correlation between online social proximity and offline mobility similarity, namely, mobile records between friends are significantly more similar than between strangers, and those between friends with common neighbors are even more similar. We argue the importance of the number and diversity of common friends, with a counter intuitive finding that the number of common friends has no positive impact on mobility similarity while the diversity plays a key role, disagreeing with previous studies. Our analysis provides a novel view for better understanding the coupling between human online and offline behaviors, and will help model and predict human behaviors based on social proximity.

  12. [Disorders of sex development and proximal hypospadias].

    Science.gov (United States)

    Oswald, J

    2016-01-01

    Children with ambiguous genitalia due to different chromosome or gonadal sex are a particular challenge concerning the diagnostic and therapeutic implications. Proximal hypospadias patients with normal gonadal development should be distinguished from children with DSD (disorders of sex development) to guarantee normal gender identity and the best possible surgical therapy. This paper focuses on the terminology, embryology, and pathophysiology of the different manifestations of DSD. The state of knowledge about this disease pattern with particular emphasis on proximal hypospadias based on national and international scientific discussions is presented. The different clinical pictures as well as therapeutic options of DSD with a special focus on recent literature and giving particular attention to patients with proximal hypospadias are presented. Because of the complexity of patients suffering from disorders of sex development an interdisciplinary DSD healthcare team including a paediatric endocrinologist as well as paediatric urologist should be provided. These specialists enable an accurate diagnosis in severe hypospadias patients without reference to DSD diseases patterns.

  13. Infiltrating/sealing proximal caries lesions

    DEFF Research Database (Denmark)

    Martignon, S; Ekstrand, K R; Gomez, J

    2012-01-01

    This randomized split-mouth controlled clinical trial aimed at assessing the therapeutic effects of infiltration vs. sealing for controlling caries progression on proximal surfaces. Out of 90 adult students/patients assessed at university clinics and agreeing to participate, 39, each with 3...... differences in lesion progression between infiltration and placebo (P = 0.0012) and between sealing and placebo (P = 0.0269). The study showed that infiltration and sealing are significantly better than placebo treatment for controlling caries progression on proximal lesions. No significant difference...... proximal lesions identified radiographically around the enamel-dentin junction to the outer third of the dentin, were included. Lesions were randomly allocated for treatment to test-A (Infiltration: ICON-pre-product; DMG), test-B (Sealing: Prime-Bond-NT; Dentsply), or control-C (Placebo). Primary outcome...

  14. Generalizing cell segmentation and quantification.

    Science.gov (United States)

    Wang, Zhenzhou; Li, Haixing

    2017-03-23

    In recent years, the microscopy technology for imaging cells has developed greatly and rapidly. The accompanying requirements for automatic segmentation and quantification of the imaged cells are becoming more and more. After studied widely in both scientific research and industrial applications for many decades, cell segmentation has achieved great progress, especially in segmenting some specific types of cells, e.g. muscle cells. However, it lacks a framework to address the cell segmentation problems generally. On the contrary, different segmentation methods were proposed to address the different types of cells, which makes the research work divergent. In addition, most of the popular segmentation and quantification tools usually require a great part of manual work. To make the cell segmentation work more convergent, we propose a framework that is able to segment different kinds of cells automatically and robustly in this paper. This framework evolves the previously proposed method in segmenting the muscle cells and generalizes it to be suitable for segmenting and quantifying a variety of cell images by adding more union cases. Compared to the previous methods, the segmentation and quantification accuracy of the proposed framework is also improved by three novel procedures: (1) a simplified calibration method is proposed and added for the threshold selection process; (2) a noise blob filter is proposed to get rid of the noise blobs. (3) a boundary smoothing filter is proposed to reduce the false seeds produced by the iterative erosion. As it turned out, the quantification accuracy of the proposed framework increases from 93.4 to 96.8% compared to the previous method. In addition, the accuracy of the proposed framework is also better in quantifying the muscle cells than two available state-of-the-art methods. The proposed framework is able to automatically segment and quantify more types of cells than state-of-the-art methods.

  15. Patch-Based Segmentation with Spatial Consistency: Application to MS Lesions in Brain MRI.

    Science.gov (United States)

    Mechrez, Roey; Goldberger, Jacob; Greenspan, Hayit

    2016-01-01

    This paper presents an automatic lesion segmentation method based on similarities between multichannel patches. A patch database is built using training images for which the label maps are known. For each patch in the testing image, k similar patches are retrieved from the database. The matching labels for these k patches are then combined to produce an initial segmentation map for the test case. Finally an iterative patch-based label refinement process based on the initial segmentation map is performed to ensure the spatial consistency of the detected lesions. The method was evaluated in experiments on multiple sclerosis (MS) lesion segmentation in magnetic resonance images (MRI) of the brain. An evaluation was done for each image in the MICCAI 2008 MS lesion segmentation challenge. Results are shown to compete with the state of the art in the challenge. We conclude that the proposed algorithm for segmentation of lesions provides a promising new approach for local segmentation and global detection in medical images.

  16. Automated medical image segmentation techniques

    Directory of Open Access Journals (Sweden)

    Sharma Neeraj

    2010-01-01

    Full Text Available Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT and Magnetic resonance (MR imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  17. ADVANCED CLUSTER BASED IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    D. Kesavaraja

    2011-11-01

    Full Text Available This paper presents efficient and portable implementations of a useful image segmentation technique which makes use of the faster and a variant of the conventional connected components algorithm which we call parallel Components. In the Modern world majority of the doctors are need image segmentation as the service for various purposes and also they expect this system is run faster and secure. Usually Image segmentation Algorithms are not working faster. In spite of several ongoing researches in Conventional Segmentation and its Algorithms might not be able to run faster. So we propose a cluster computing environment for parallel image Segmentation to provide faster result. This paper is the real time implementation of Distributed Image Segmentation in Clustering of Nodes. We demonstrate the effectiveness and feasibility of our method on a set of Medical CT Scan Images. Our general framework is a single address space, distributed memory programming model. We use efficient techniques for distributing and coalescing data as well as efficient combinations of task and data parallelism. The image segmentation algorithm makes use of an efficient cluster process which uses a novel approach for parallel merging. Our experimental results are consistent with the theoretical analysis and practical results. It provides the faster execution time for segmentation, when compared with Conventional method. Our test data is different CT scan images from the Medical database. More efficient implementations of Image Segmentation will likely result in even faster execution times.

  18. Knowledge networks in the Dutch aviation industry: The proximity paradox

    NARCIS (Netherlands)

    Broekel, T.; Boschma, R.A.

    2012-01-01

    The importance of geographical proximity for interaction and knowledge sharing has been discussed extensively in recent years. There is increasing consensus that geographical proximity is just one out of many types of proximities that might be relevant. We argue that proximity may be a crucial

  19. Joint axes of rotation and body segment parameters of pig limbs

    Science.gov (United States)

    Thorup, Vivi M; Aa Tøgersen, Frede; Jørgensen, Bente; Jensen, Bente R

    2007-01-01

    To enable a quantification of net joint moments and joint reaction forces, indicators of joint loading, this study aimed to locate the mediolateral joint axes of rotation and establish the body segment parameters of the limbs of pigs (Sus scrofa). To locate the joint axes of rotation the scapulohumeral, humeroradial, carpal complex, metacarpophalangeal, coxofemoral, femorotibial, tarsal, and metatarsophalangeal joints from 12 carcasses were studied. The joints were photographed in three positions, bisecting lines drawn at fixed landmarks with their intersection marking the joint axes of rotation. The body segment parameters, i.e. the segment mass, center of mass and moment of inertia were measured on the humerus, radius/ulna, metacarpus, forepastern, foretoe, femur, tibia, metatarsus, hindpastern, and hindtoe segments from five carcasses. The segments were weighed, and their center of mass was found by balancing them. The moments of inertia of the humerus, radius/ulna, femur and tibia were found by rotating the segments. The moments of inertia of the remaining segments were calculated. Generally, the joint axes of rotation were near the attachment site of the lateral collateral ligaments. The forelimb, with segments taken as one, was significantly lighter and shorter than the hindlimb (P < 0.001). In all segments the center of mass was located 31 to 50% distal to the proximal segment end. The segment mass decreased with distance from the trunk, as did the segment moment of inertia. The results may serve as reference on the location of the joint axes of rotation and on the body segment parameters for inverse dynamic modeling of pigs. PMID:17822536

  20. Cardiac segmentation by a velocity-aided active contour model.

    Science.gov (United States)

    Cho, Jinsoo; Benkeser, Paul J

    2006-01-01

    Heart disease is one of the more life-threatening diseases. Accurate diagnosis and treatment are central to the survival of patients. Numerous diagnostic methods that can assess abnormalities of the heart have been developed. Among these methods, cardiac functional analysis has been widely used to derive cardiac functional parameters that describe the functionality of the heart and are frequently used in diagnosis of various heart diseases. Segmentation of the myocardial boundaries is an essential step for deriving these cardiac functional parameters, and the accuracy of parameters depends much on the correctness of the segmented boundaries. Therefore, it is essential that cardiac segmentation be accurate and reliable. However, current segmentation techniques still have difficulty both extracting accurate myocardial boundaries, especially the endocardial boundary and performing a fully automatic process because of low image quality, the complex shape and motion pattern of the heart, and lack of clear delineation between the myocardium and adjacent anatomic structures. A velocity-aided cardiac segmentation method based a modified active contour model, the tensor-based orientation gradient force (OGF) and phase contrast magnetic resonance imaging (MRI) has been developed to improve the accuracy of segmentation of the myocardial boundaries, especially the endocardial boundary. Furthermore, the initial seed contour tracking (SCT) algorithm has been also developed to improve the accuracy of automatic sequential frame segmentation in conjunction with the OGF-based segmentation method. The performance of the proposed method was assessed by experimentations on a phase contrast MRI data set of three normal human volunteer. The results of the individual frame segmentation showed that the accuracy and reproducibility of segmentation of the endocardial boundary by the use of the OGF was generally improved around the lower level of the LV and end systole. The results of the

  1. Image Segmentation Method Using Thresholds Automatically Determined from Picture Contents

    Directory of Open Access Journals (Sweden)

    Yuan Been Chen

    2009-01-01

    Full Text Available Image segmentation has become an indispensable task in many image and video applications. This work develops an image segmentation method based on the modified edge-following scheme where different thresholds are automatically determined according to areas with varied contents in a picture, thus yielding suitable segmentation results in different areas. First, the iterative threshold selection technique is modified to calculate the initial-point threshold of the whole image or a particular block. Second, the quad-tree decomposition that starts from the whole image employs gray-level gradient characteristics of the currently-processed block to decide further decomposition or not. After the quad-tree decomposition, the initial-point threshold in each decomposed block is adopted to determine initial points. Additionally, the contour threshold is determined based on the histogram of gradients in each decomposed block. Particularly, contour thresholds could eliminate inappropriate contours to increase the accuracy of the search and minimize the required searching time. Finally, the edge-following method is modified and then conducted based on initial points and contour thresholds to find contours precisely and rapidly. By using the Berkeley segmentation data set with realistic images, the proposed method is demonstrated to take the least computational time for achieving fairly good segmentation performance in various image types.

  2. Responses of proximal tubular cells to injury in congenital renal disease: fight or flight.

    Science.gov (United States)

    Chevalier, Robert L; Forbes, Michael S; Galarreta, Carolina I; Thornhill, Barbara A

    2014-04-01

    Most chronic kidney disease in children results from congenital or inherited disorders, which can be studied in mouse models. Following 2 weeks of unilateral ureteral obstruction (UUO) in the adult mouse, nephron loss is due to proximal tubular mitochondrial injury and cell death. In neonatal mice, proximal tubular cell death is delayed beyond 2 weeks of complete UUO, and release of partial UUO allows remodeling of remaining nephrons. Progressive cyst expansion develops in polycystic kidney disease (PKD), a common inherited renal disorder. The polycystic kidney and fibrosis (pcy)-mutant mouse (which develops late-onset PKD) develops thinning of the glomerulotubular junction in parallel with growth of cysts in adulthood. Renal insufficiency in nephropathic cystinosis, a rare inherited renal disorder, results from progressive tubular cystine accumulation. In the Ctns knockout mouse (a model of cystinosis), proximal tubular cells become flattened, with loss of mitochondria and thickening of tubular basement membrane. In each model, persistent obstructive or metabolic stress leads ultimately to the formation of atubular glomeruli. The initial "fight" response (proximal tubular survival) switches to a "flight" response (proximal tubular cell death) with ongoing oxidative injury and mitochondrial damage. Therapies should be directed at reducing proximal tubular mitochondrial oxidative injury to enhance repair and regeneration.

  3. Transverse preputial onlay island flap urethroplasty for single-stage correction of proximal hypospadias.

    Science.gov (United States)

    Singal, Arbinder Kumar; Dubey, Manish; Jain, Viral

    2016-07-01

    Transverse preputial onlay island flap urethroplasty (TPOIF) was described initially for distal hypospadias, but has seen extended application for proximal hypospadias. We describe a set of modifications in the technique and results in a large series of proximal hypospadias. All children who underwent TPOIF repair for proximal hypospadias (proximal penile, penoscrotal and scrotal) from June 2006 to June 2013 by a single surgeon were prospectively followed till June, 2014. A standard technique and postoperative protocol were followed. Salient points to be emphasized in the technique: (1) dissection of the dartos pedicle till penopubic junction to prevent penile torsion, (2) incorporation of the spongiosum in the urethroplasty, (3) midline urethral plate incision in glans (hinging the plate), (4) Dartos blanket cover on whole urethroplasty. Out of 136 children with proximal hypospadias, 92 children who underwent TPOIF formed the study group. Out of 92 children, 48 (52 %) children required a tunica albuginea plication for chordee correction. In total, 16 (17 %) patients developed 24 complications and 11 children (12 %) required second surgeries: fistula closure in 7 (with meatoplasty in 5), glansplasty for glans dehiscence in 2 and excision of diverticulum in 2. Two children required a third surgery. Only 5 children had a noticeable penile torsion (less than 30 degree), and 7 had a patulous meatus. Transverse preputial onlay island flap urethroplasty can deliver reliable cosmetic and functional outcomes in proximal hypospadias.

  4. A Fully Automated Penumbra Segmentation Tool

    DEFF Research Database (Denmark)

    Nagenthiraja, Kartheeban; Ribe, Lars Riisgaard; Hougaard, Kristina Dupont

    2012-01-01

    Introduction: Perfusion- and diffusion weighted MRI (PWI/DWI) is widely used to select patients who are likely to benefit from recanalization therapy. The visual identification of PWI-DWI-mismatch tissue depends strongly on the observer, prompting a need for software, which estimates potentially...... salavageable tissue, quickly and accurately. We present a fully Automated Penumbra Segmentation (APS) algorithm using PWI and DWI images. We compare automatically generated PWI-DWI mismatch mask to mask outlined manually by experts, in 168 patients. Method: The algorithm initially identifies PWI lesions...... by applying a connected component-labeling algorithm on thresholded Time-To-Peak maps (TTP > 4 seconds). Smooth PWI lesion borders are then identified by applying a level-set algorithm on the initial PWI lesion mask. The initial DWI lesion was located by thresholding Apparent Diffusion Coefficient (ADC...

  5. preliminary phytochemical screening, proximate and elemental

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The seed powder of Moringa oleifera was analysed for its phytochemical, proximate and elemental composition using Folin-Denis spectrophotometric method, gravimetric method and energy dispersing X-ray fluorescence (EDXRF) transmission emission technique respectively. The seed powder had the ...

  6. Proximate, mineral composition, antioxidant activity, and total ...

    African Journals Online (AJOL)

    Four varieties of the red pepper fruits (Capsicum species) were evaluated for chemical composition, antioxidant activity and total phenolic contents using standard analytical technique, ferric-ion reducing antioxidant potential (FRAP) assay and Folin-Colcalteau method respectively. The proximate composition values ...

  7. 9__43 - 50__Tijjani_Proximate

    African Journals Online (AJOL)

    User

    Sena et al., 1998). In Nigeria, the plant is commonly consumed by the Hausa speaking communities as a spice and a sauce (Ibrahim et al., 2012). However, during preparation the leaves and stem are not carefully separated before processing of food. Thus, the present study was aimed at evaluating the proximate, minerals ...

  8. Phytochemistry and proximate composition of ginger ( Zingiber ...

    African Journals Online (AJOL)

    ... a little crude fibre content of 0.92 %. The results indicated that ginger rhizome is an excellent natural remedy for a wide range of ailments. Keywords: Zingiber officinale, spice, rhizome, phytochemistry, proximate analysis, Zingiberaceae, zingerone, methanolic extraction. Journal of Pharmaceutical and Allied Sciences, Vol.

  9. DEPRESSIONARY EFFECT OF PROXIMITY OF RESIDENTIAL ...

    African Journals Online (AJOL)

    Osondu

    2012-10-24

    Oct 24, 2012 ... opinions are analyzed and it revealed that the site has major impacts on the residents perceived quality of life, security and ... Key words: Landfill, Property value, Health and safety, Residential property, Solous. Introduction. The location ... Proximity to landfills and hazardous waste sites can severely affect ...

  10. 182 179 Comparative Study on the Proximate

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... Key words: Annona squamosa, Fruits, Proximate, Minerals, nutrient density. INTRODUCTION. Sugar apple (Annona squamosa) also called. “Gwanda masar” in Hausa belong to the family. Annonacae. The most widely grown of all the species are A. muricata, A. cherimola, A reticulata, A. senegalensis and ...

  11. Phytochemical Screening, Proximate and Mineral Composition of ...

    African Journals Online (AJOL)

    Leaves of sweet potato (Ipomoea batatas) grown in Tepi area was studied for their class of phytochemicals, mineral and proximate composition using standard analytical methods. The phytochemical screening revealed the presence of alkaloids, flavonoid, terpenoids, saponins, quinones, phenol, tannins, amino acid and ...

  12. Phytochemical screening, proximate and elemental analysis of ...

    African Journals Online (AJOL)

    Citrus sinensis was screened for its phytochemical composition and was evaluated for the proximate and elemental analysis. The phytochemical analysis indicated the presence of reducing sugar, saponins, cardiac glycosides, tannins and flavonoids. The elemental analysis indicated the presence of the following mineral ...

  13. Phytochemical Screening and Proximate Analysis of Newbouldia ...

    African Journals Online (AJOL)

    The study was conducted to assess the phytochemical and proximate composition of Newboudia laevis leaves and Allium sativum bulb extracts. The leaves and bulbs extracts were analyzed for their chemical composition and antinutritional factors (ANFs) which include moisture, crude protein, crude fat, crude fiber, total ash ...

  14. Disability occurrence and proximity to death

    NARCIS (Netherlands)

    Klijs, Bart; Mackenbach, Johan P.; Kunst, Anton E.

    2010-01-01

    Purpose. This paper aims to assess whether disability occurrence is related more strongly to proximity to death than to age. Method. Self reported disability and vital status were available from six annual waves and a subsequent 12-year mortality follow-up of the Dutch GLOBE longitudinal study.

  15. [Four family members with proximal myotonic myopathy

    NARCIS (Netherlands)

    Tieleman, A.A.; Velden, M.P. van der; Visser, M.C.; Wokke, J.H.J.; Scheffer, H.; Engelen, B.G.M. van

    2004-01-01

    A 41-year-old woman had a 15-year history of pain in her thighs and arms, which also became weaker, and a decrease in visual acuity. Her 35-year-old brother, their 38-year-old sister and their 64-year-old mother also had myalgia, myotonia and proximal muscle weakness, and the women also had

  16. Phytochemical screening, proximate and elemental analysis of ...

    African Journals Online (AJOL)

    ... was about 0.01 in concentration. Proximate analysis also shows that it has a high nutritional value such as carbohydrate, fibre, Ash, fat and protein. These results recommended the consumption of these peels of desired physiochemical properties as sources of food fibres or low-calorie bulk ingredients in food applications ...

  17. Proximate composition and consumer acceptability of African ...

    African Journals Online (AJOL)

    The aim of the study was to assess the organoleptic differences of Clarias gariepinus smoked with two different energy sources, Anogeissus leiocarpus and Tamarindus indica with the help of a hedonic scale and to determine possible proximate composition difference between the smoked products. Smoking of the fishes ...

  18. Controllable proximity effect in superconducting hybrid devices

    NARCIS (Netherlands)

    Bakurskiy, S.V.

    2015-01-01

    This thesis is devoted to the study of controllable proximity effects in superconductors, both in terms of fundamental aspects and applications. As a part of this thesis theoretical description was suggested for a number of structures with superconducting electrodes and multiple interlayers. These

  19. Proximate, chemical compositions and sulphur concentrations on ...

    African Journals Online (AJOL)

    0, 10, 20, 50, 100, 150, 200, 250 and 300 ppm) on the nutritional value and the proximate composition of six selected mango cultivars (Tommy Atkins, Peach, Saber, Sunshine, Keitt and Vhavenda) grown in South Africa. The study shows that ...

  20. Proximate composition, bread characteristics and sensory ...

    African Journals Online (AJOL)

    This study was carried out to investigate proximate composition, bread characteristics and sensory evaluation of cocoyam-wheat composite breads at different levels of cocoyam flour substitution for human consumption.A whole wheat bread (WWB) and cocoyam-composite breads (CCB1,CCB 2 and CCB 3) were prepared ...

  1. Evaluation of the Proximate, Chemical and Phytochemical ...

    African Journals Online (AJOL)

    The increased interest in the utilization of the leaves of Moringa oleifera necessitated this study which evaluated the proximate, chemical and phytochemical composition, especially the presence of anti- physiological and toxic factors in the leaves. The results of the phytochemical analyses were: alkaloid 1.24 ± 0.141%; ...

  2. comparative proximate composition and antioxidant vitamins

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The proximate composition and antioxidant vitamins analysis of two varieties of honey (dark amber and light amber) were carried out using standard methods. The values for moisture, ash, crude lipid, crude protein and crude carbohydrate contents of the two honeys, (light amber and dark amber) are 9.39 ...

  3. Proximate composition and cholesterol concentrations of ...

    African Journals Online (AJOL)

    Proximate composition and cholesterol concentrations of Rhynchophorus phoenicis and Oryctes monoceros larvae subjected to different heat treatments. ... 514.63 mg/100g dry weight basis (DWB) for raw and fried samples, respectively, but decreased to 295.20 mg/100 g DWB in the smoke-dried samples. Similarly, the ...

  4. Preliminary Phytochemical Screening, Elemental and Proximate ...

    African Journals Online (AJOL)

    The study aimed at phytochemical screening, elemental and proximate composition of two varieties of Cyperus esculentus (tiger nut) big yellow and small brown nuts using standard methods. The phytochemicals tested for were alkaloid, saponin, tannin, glycoside, flavonoid, steroid and resin. All the aforementioned ...

  5. Phytochemical screening, proximate and elemental analysis of ...

    African Journals Online (AJOL)

    Michael Horsfall

    2009). The aim of this study was to analyses the extract of. Citrus sinensis peels for the phytochemical, proximate and elemental composition. MATERIALS AND METHODS. Plant materials Fresh peels of Citrus sinensis were collected from Uselu market in Benin City, Edo. State, Nigeria. It was identified and authenticated by.

  6. Keldysh proximity action for disordered superconductors

    Indian Academy of Sciences (India)

    Abstract. We review a novel approach to the superconductive proximity effect in dis- ordered normal–superconducting (N–S) structures. The method is based on the multi- charge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap ...

  7. Goal-Proximity Decision-Making

    Science.gov (United States)

    Veksler, Vladislav D.; Gray, Wayne D.; Schoelles, Michael J.

    2013-01-01

    Reinforcement learning (RL) models of decision-making cannot account for human decisions in the absence of prior reward or punishment. We propose a mechanism for choosing among available options based on goal-option association strengths, where association strengths between objects represent previously experienced object proximity. The proposed…

  8. High-resolution CISS MR imaging with and without contrast for evaluation of the upper cranial nerves: segmental anatomy and selected pathologic conditions of the cisternal through extraforaminal segments.

    Science.gov (United States)

    Blitz, Ari M; Macedo, Leonardo L; Chonka, Zachary D; Ilica, Ahmet T; Choudhri, Asim F; Gallia, Gary L; Aygun, Nafi

    2014-02-01

    The authors review the course and appearance of the major segments of the upper cranial nerves from their apparent origin at the brainstem through the proximal extraforaminal region, focusing on the imaging and anatomic features of particular relevance to high-resolution magnetic resonance imaging evaluation. Selected pathologic entities are included in the discussion of the corresponding cranial nerve segments for illustrative purposes. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. A micropuncture study of proximal tubular transport of lithium during osmotic diuresis

    DEFF Research Database (Denmark)

    Leyssac, P P; Holstein-Rathlou, N H; Skøtt, P

    1990-01-01

    Lithium and sodium are normally reabsorbed in parallel with water by the renal proximal tubule whereby their tubular fluid-to-plasma concentration ratios (TF/P) remain close to unity throughout the proximal convoluted segment. During osmotic diuresis, the late proximal (TF/P)Na is known to decrease....... The present experiments were undertaken to study whether the late proximal TF/P for Li decreases like that of Na during osmotic diuresis. Data were obtained in a control period (C) and in two successive periods during mannitol diuresis (P1, P2). Glomerular filtration rate decreased gradually during osmotic...... diuresis [1,147 +/- 32 (C) to 950 +/- 22 (P2) microliters.min-1.g kidney wt (KW)-1, P less than 0.01), whereas Li clearance (CLi) increased [377 +/- 21 (C) to 469 +/- 28 (P1, P less than 0.01) and 408 +/- 25 (P2, NS) microliters.min-1.gKW-1, respectively]. (TF/P)Na decreased from 0.98 +/- 0.02 (C) to 0...

  10. Proximal Tubular Injury in Medullary Rays Is an Early Sign of Acute Tacrolimus Nephrotoxicity

    Directory of Open Access Journals (Sweden)

    Diane Cosner

    2015-01-01

    Full Text Available Tacrolimus (FK506 is one of the principal immunosuppressive agents used after solid organ transplantations to prevent allograft rejection. Chronic renal injury induced by tacrolimus is characterized by linear fibrosis in the medullary rays; however, the early morphologic findings of acute tacrolimus nephrotoxicity are not well characterized. Kidney injury molecule-1 (KIM-1 is a specific injury biomarker that has been proven to be useful in the diagnosis of mild to severe acute tubular injury on renal biopsies. This study was motivated by a patient with acute kidney injury associated with elevated serum tacrolimus levels in whom KIM-1 staining was present only in proximal tubules located in the medullary rays in the setting of otherwise normal light, immunofluorescent, and electron microscopy. We subsequently evaluated KIM-1 expression in 45 protocol and 39 indicated renal transplant biopsies to determine whether higher serum levels of tacrolimus were associated with acute segment specific injury to the proximal tubule, as reflected by KIM-1 staining in the proximal tubules of the cortical medullary rays. The data suggest that tacrolimus toxicity preferentially affects proximal tubules in medullary rays and that this targeted injury is a precursor lesion for the linear fibrosis seen in chronic tacrolimus toxicity.

  11. IFRS 8 – OPERATING SEGMENTS

    Directory of Open Access Journals (Sweden)

    BOCHIS LEONICA

    2009-05-01

    Full Text Available Segment reporting in accordance with IFRS 8 will be mandatory for annual financial statements covering periods beginning on or after 1 January 2009. The standards replaces IAS 14, Segment Reporting, from that date. The objective of IFRS 8 is to require

  12. Segmental neurofibromatosis [NF type - v].

    Science.gov (United States)

    Arfan-ul-Bari; Simeen-ber-Rahman

    2003-12-01

    Segmental neurofibromatosis is a rare variant of neurofibromatosis in which skin lesions are confined to a circumscribed body segment. A case of a 39-year-old man with this condition is presented, who was having multiple soft skin tumours over a localized area of back with no associated cafe au lait spots, axillary freckles or lish nodules. Histology confirmed the diagnosis of neurofibroma.

  13. Market Segmentation: An Instructional Module.

    Science.gov (United States)

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  14. Adaptive segmentation for scientific databases

    NARCIS (Netherlands)

    Ivanova, M.; Kersten, M.L.; Nes, N.

    2008-01-01

    In this paper we explore database segmentation in the context of a column-store DBMS targeted at a scientific database. We present a novel hardware- and scheme-oblivious segmentation algorithm, which learns and adapts to the workload immediately. The approach taken is to capitalize on (intermediate)

  15. Market segmentation using perceived constraints

    Science.gov (United States)

    Jinhee Jun; Gerard Kyle; Andrew Mowen

    2008-01-01

    We examined the practical utility of segmenting potential visitors to Cleveland Metroparks using their constraint profiles. Our analysis identified three segments based on their scores on the dimensions of constraints: Other priorities--visitors who scored the highest on 'other priorities' dimension; Highly Constrained--visitors who scored relatively high on...

  16. Using Predictability for Lexical Segmentation

    Science.gov (United States)

    Çöltekin, Çagri

    2017-01-01

    This study investigates a strategy based on predictability of consecutive sub-lexical units in learning to segment a continuous speech stream into lexical units using computational modeling and simulations. Lexical segmentation is one of the early challenges during language acquisition, and it has been studied extensively through psycholinguistic…

  17. IFRS 8 – OPERATING SEGMENTS

    OpenAIRE

    BOCHIS LEONICA; Sucala Lucia; DUMBRAVA PARTENIE; BREBAN LUDOVICA

    2009-01-01

    Segment reporting in accordance with IFRS 8 will be mandatory for annual financial statements covering periods beginning on or after 1 January 2009. The standards replaces IAS 14, Segment Reporting, from that date. The objective of IFRS 8 is to require

  18. The Importance of Marketing Segmentation

    Science.gov (United States)

    Martin, Gillian

    2011-01-01

    The rationale behind marketing segmentation is to allow businesses to focus on their consumers' behaviors and purchasing patterns. If done effectively, marketing segmentation allows an organization to achieve its highest return on investment (ROI) in turn for its marketing and sales expenses. If an organization markets its products or services to…

  19. Essays in international market segmentation

    NARCIS (Netherlands)

    Hofstede, ter F.

    1999-01-01

    The primary objective of this thesis is to develop and validate new methodologies to improve the effectiveness of international segmentation strategies. The current status of international market segmentation research is reviewed in an introductory chapter, which provided a number of

  20. Controversies in the intramedullary nailing of proximal and distal tibia fractures.

    Science.gov (United States)

    Tejwani, Nirmal; Polonet, David; Wolinsky, Philip R

    2014-10-01

    Management of tibia fractures by internal fixation, particularly intramedullary nails, has become the standard for diaphyseal fractures. However, for metaphyseal fractures or those at the metaphyseal-diaphyseal junction, choice of fixation device and technique is controversial. For distal tibia fractures, nailing and plating techniques may be used, the primary goal of each being to achieve acceptable alignment with minimal complications. Different techniques for reduction of these fractures are available and can be applied with either fixation device. Overall outcomes appear to be nearly equivalent, with minor differences in complications. Proximal tibia fractures can be fixed using nailing, which is associated with deformity of the proximal short segment. A newer technique-suprapatellar nailing-may minimize these problems, and use of this method has been increasing in trauma centers. However, most of the data are still largely based on case series. Copyright 2014 by the American Academy of Orthopaedic Surgeons.

  1. Intestinal, segmented, filamentous bacteria.

    Science.gov (United States)

    Klaasen, H L; Koopman, J P; Poelma, F G; Beynen, A C

    1992-06-01

    Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occurring in the ileum of mice and rats. Although the application of formal taxonomic criteria is impossible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.

  2. [Orbitotemporal segmental neurofibromatosis].

    Science.gov (United States)

    Montard, R; Putz, C; Barrali, M; Kantelip, B; Montard, M

    2007-11-01

    Neurofibromatosis is a rare pathology with heterogeneous clinical presentation. We report a case of a right orbitotemporal plexiform neurofibroma in a 64-year-old woman with von Recklinghausen's neurofibromatosis. A craniofacial CT scan, with injection, showed a heterogeneous tumor in front of the skull base and the temporoparietal bone with no intracranial extension but an extension into the maxillary sinus and nasal cavity. In summery, she presented orbitotemporal segmental neurofibromatosis type 1 because of the unilateral lesion. She had a first surgery to remove her jugal and preauricular tumor with an exenteration, which provided an eye histology. The histology found no Lisch nodules but a cellular proliferation causing choroidal hyperplasia. We noted neurofibromin on choroidal cells and normal cells in addition to pathologic cells (Schwann cells and melanocytes), meaning that two cell populations were obtained in the same tissue: a somatic mosaicism. We advance the hypothesis that there was a regulation of cellular growth in a particular microenvironment because of the absence of tumor. To identify and confirm the somatic mosaicism, we would need a FISH analysis (probes containing sequences of the NF1 gene with a probe specific for the chromosome 17 centromere).

  3. Segmentation and determination of joint space width in foot radiographs

    Science.gov (United States)

    Schenk, O.; de Muinck Keizer, D. M.; Bernelot Moens, H. J.; Slump, C. H.

    2016-03-01

    Joint damage in rheumatoid arthritis is frequently assessed using radiographs of hands and feet. Evaluation includes measurements of the joint space width (JSW) and detection of erosions. Current visual scoring methods are timeconsuming and subject to inter- and intra-observer variability. Automated measurement methods avoid these limitations and have been fairly successful in hand radiographs. This contribution aims at foot radiographs. Starting from an earlier proposed automated segmentation method we have developed a novel model based image analysis algorithm for JSW measurements. This method uses active appearance and active shape models to identify individual bones. The model compiles ten submodels, each representing a specific bone of the foot (metatarsals 1-5, proximal phalanges 1-5). We have performed segmentation experiments using 24 foot radiographs, randomly selected from a large database from the rheumatology department of a local hospital: 10 for training and 14 for testing. Segmentation was considered successful if the joint locations are correctly determined. Segmentation was successful in only 14%. To improve results a step-by-step analysis will be performed. We performed JSW measurements on 14 randomly selected radiographs. JSW was successfully measured in 75%, mean and standard deviation are 2.30+/-0.36mm. This is a first step towards automated determination of progression of RA and therapy response in feet using radiographs.

  4. The Proximity Electronics of the GAIA Focal Plane

    Science.gov (United States)

    Fernandez, Alejandro; Peran, Francisco; Elorz, Ainhoa; Cuesta, Hermilo; Velasco, Raul; Polo, Jesus

    2011-08-01

    Gaia (Global Astrometric Intereferomenter for Astrophysics) is an ESA mission which will chart a three-dimensional map of our Galaxy, continuing the work initiated with ESA Hipparcos mission. The main objective is to investigate the origin and evolution of the Milky Way. This goal will be achieved by measuring the position and motion of around 1 billion stars, as well as measuring the physical properties of each star.The spacecraft payload consists of a single instrument. This instrument provides three functions (Astrometry, Photometry and Spectrometry), which will use common telescopes and a shared focal plane.The Focal Plane Assembly (FPA) will be the largest ever developed, comprising 106 CCDs-PEMs (Proximity Electronics Module) pairs, for a total 1 Gigapixels and 0.5x1 m dimensions. The CCDs are distributed on an array layout, with the different functions in separate columns. The proximity electronics main functions are CCD operation, video processing, sequencing and power supply distribution. A single PEM design is used for all the focal plane functions, as it is able to adapt the sequencing, biasing, video bandwidth and gain to each instrument function. All these functions and capabilities have been integrated in a very small module, weighting only 162 g.The video processing includes analogue amplification, filtering, A/D conversion and digital processing. This extremely exigent electronic module is able to deliver very low noise levels on a 16 bit video chain, in the range of fractions of a LSB.Such demanding level of performances has made necessary the use of commercial off-the-shelf (COTS) parts instead of Hi-Rel parts for certain taxing functions of the PEM. Furthermore, the level of exigency in performances has been extremely difficult to achieve not only on the PEM, but on the test equipment also, so as to demonstrate the full capabilities of the proximity electronics. The excellent performances of the PEM will help to achieve the very challenging goals

  5. Satellite Image Classification and Segmentation by Using JSEG Segmentation Algorithm

    OpenAIRE

    Khamael Abbas; Mustafa Rydh

    2012-01-01

    In this paper, a adopted approach to fully automatic satellite image segmentation, called JSEG, "JPEG image segmentation" is presented. First colors in the image are quantized to represent differentiate regions in the image. Then image pixel colors are replaced by their corresponding color class labels, thus forming a class-map of the image. A criterion for “good” segmentation using this class-map is proposed. Applying the criterion to local windows in the class-map results in the “J-image”...

  6. Multiresolution Multiscale Active Mask Segmentation of Fluorescence Microscope Images.

    Science.gov (United States)

    Srinivasa, Gowri; Fickus, Matthew; Kovačević, Jelena

    2009-01-01

    We propose an active mask segmentation framework that combines the advantages of statistical modeling, smoothing, speed and flexibility offered by the traditional methods of region-growing, multiscale, multiresolution and active contours respectively. At the crux of this framework is a paradigm shift from evolving contours in the continuous domain to evolving multiple masks in the discrete domain. Thus, the active mask framework is particularly suited to segment digital images. We demonstrate the use of the framework in practice through the segmentation of punctate patterns in fluorescence microscope images. Experiments reveal that statistical modeling helps the multiple masks converge from a random initial configuration to a meaningful one. This obviates the need for an involved initialization procedure germane to most of the traditional methods used to segment fluorescence microscope images. While we provide the mathematical details of the functions used to segment fluorescence microscope images, this is only an instantiation of the active mask framework. We suggest some other instantiations of the framework to segment different types of images.

  7. Segmentation of the quadratus lumborum muscle using statistical shape modeling.

    Science.gov (United States)

    Engstrom, Craig M; Fripp, Jurgen; Jurcak, Valer; Walker, Duncan G; Salvado, Olivier; Crozier, Stuart

    2011-06-01

    To compare automated segmentation of the quadratus lumborum (QL) based on statistical shape modeling (SSM) with conventional manual processing of magnetic resonance (MR) images for segmentation of this paraspinal muscle. The automated SSM scheme for QL segmentation was developed using an MR database of 7 mm axial images of the lumbar region from 20 subjects (cricket fast bowlers and athletic controls). Specifically, a hierarchical 3D-SSM scheme for segmentation of the QL, and surrounding psoas major (PS) and erector spinae+multifidus (ES+MT) musculature, was implemented after image preprocessing (bias field correction, partial volume interpolation) followed by image registration procedures to develop average and probabilistic MR atlases for initializing and constraining the SSM segmentation of the QL. The automated and manual QL segmentations were compared using spatial overlap and average surface distance metrics. The spatial overlap between the automated SSM and manual segmentations had a median Dice similarity metric of 0.87 (mean = 0.86, SD = 0.08) and mean average surface distance of 1.26 mm (SD = 0.61) and 1.32 mm (SD = 0.60) for the right and left QL muscles, respectively. The current SSM scheme represents a promising approach for future automated morphometric analyses of the QL and other paraspinal muscles from MR images. Copyright © 2011 Wiley-Liss, Inc.

  8. Hippocampus segmentation using locally weighted prior based level set

    Science.gov (United States)

    Achuthan, Anusha; Rajeswari, Mandava

    2015-12-01

    Segmentation of hippocampus in the brain is one of a major challenge in medical image segmentation due to its' imaging characteristics, with almost similar intensity between another adjacent gray matter structure, such as amygdala. The intensity similarity has causes the hippocampus to have weak or fuzzy boundaries. With this main challenge being demonstrated by hippocampus, a segmentation method that relies on image information alone may not produce accurate segmentation results. Therefore, it is needed an assimilation of prior information such as shape and spatial information into existing segmentation method to produce the expected segmentation. Previous studies has widely integrated prior information into segmentation methods. However, the prior information has been utilized through a global manner integration, and this does not reflect the real scenario during clinical delineation. Therefore, in this paper, a locally integrated prior information into a level set model is presented. This work utilizes a mean shape model to provide automatic initialization for level set evolution, and has been integrated as prior information into the level set model. The local integration of edge based information and prior information has been implemented through an edge weighting map that decides at voxel level which information need to be observed during a level set evolution. The edge weighting map shows which corresponding voxels having sufficient edge information. Experiments shows that the proposed integration of prior information locally into a conventional edge-based level set model, known as geodesic active contour has shown improvement of 9% in averaged Dice coefficient.

  9. Improving level set method for fast auroral oval segmentation.

    Science.gov (United States)

    Yang, Xi; Gao, Xinbo; Tao, Dacheng; Li, Xuelong

    2014-07-01

    Auroral oval segmentation from ultraviolet imager images is of significance in the field of spatial physics. Compared with various existing image segmentation methods, level set is a promising auroral oval segmentation method with satisfactory precision. However, the traditional level set methods are time consuming, which is not suitable for the processing of large aurora image database. For this purpose, an improving level set method is proposed for fast auroral oval segmentation. The proposed algorithm combines four strategies to solve the four problems leading to the high-time complexity. The first two strategies, including our shape knowledge-based initial evolving curve and neighbor embedded level set formulation, can not only accelerate the segmentation process but also improve the segmentation accuracy. And then, the latter two strategies, including the universal lattice Boltzmann method and sparse field method, can further reduce the time cost with an unlimited time step and narrow band computation. Experimental results illustrate that the proposed algorithm achieves satisfactory performance for auroral oval segmentation within a very short processing time.

  10. Mammogram segmentation using maximal cell strength updation in cellular automata.

    Science.gov (United States)

    Anitha, J; Peter, J Dinesh

    2015-08-01

    Breast cancer is the most frequently diagnosed type of cancer among women. Mammogram is one of the most effective tools for early detection of the breast cancer. Various computer-aided systems have been introduced to detect the breast cancer from mammogram images. In a computer-aided diagnosis system, detection and segmentation of breast masses from the background tissues is an important issue. In this paper, an automatic segmentation method is proposed to identify and segment the suspicious mass regions of mammogram using a modified transition rule named maximal cell strength updation in cellular automata (CA). In coarse-level segmentation, the proposed method performs an adaptive global thresholding based on the histogram peak analysis to obtain the rough region of interest. An automatic seed point selection is proposed using gray-level co-occurrence matrix-based sum average feature in the coarse segmented image. Finally, the method utilizes CA with the identified initial seed point and the modified transition rule to segment the mass region. The proposed approach is evaluated over the dataset of 70 mammograms with mass from mini-MIAS database. Experimental results show that the proposed approach yields promising results to segment the mass region in the mammograms with the sensitivity of 92.25% and accuracy of 93.48%.

  11. Monteggia fracture-dislocation: a case report, its' initial management ...

    African Journals Online (AJOL)

    Fracture of proximal ulna and dislocation of the proximal radio-ulna joint in the same arm is called Monteggia fracture- dislocation. Four clinical variants of this fracture- dislocation have been described in literature. This is a report and description of initial management of a fracture- dislocation, which was consequent to a ...

  12. Sometimes spelling is easier than phonemic segmentation

    NARCIS (Netherlands)

    Bon, W.H.J. van; Duighuisen, H.C.M.

    1995-01-01

    Poor spellers from the Netherlands segmented and spelled the same words on different occasions. If they base their spellings on the segmentations that they produce in the segmentation task, the correlation between segmentation and spelling scores should be high, and segmentation should not be more

  13. Intestinal Neuronal Dysplasia-Like Submucosal Ganglion Cell Hyperplasia at the Proximal Margins of Hirschsprung Disease Resections.

    Science.gov (United States)

    Swaminathan, Maya; Oron, Assaf P; Chatterjee, Sumantra; Piper, Hannah; Cope-Yokoyama, Sandy; Chakravarti, Aravinda; Kapur, Raj P

    2015-01-01

    Intestinal neuronal dysplasia type B (IND) denotes an increased proportion of hyperplastic submucosal ganglia, as resolved histochemically in 15-μm-thick frozen sections. IND has been reported proximal to the aganglionic segment in patients with Hirschsprung disease (HSCR) and is putatively associated with a higher rate of postsurgical dysmotility. We developed and validated histological criteria to diagnose IND-like submucosal ganglion cell hyperplasia (IND-SH) in paraffin sections and used the approach to study the incidence and clinical and/or genetic associations of IND-SH at the proximal margins of HSCR pull-through resection specimens. Full-circumference paraffin sections from the proximal margins of 64 HSCR colonic pull-through specimens and 24 autopsy controls were immunostained for neuron-specific Hu antigen, and nucleated ganglion cells in each submucosal ganglion were counted. In controls, an age-related decline in the relative abundance of "giant" ganglia (≥7 nucleated Hu-positive [Hu+] ganglion cells) was observed. A conservative diagnostic threshold for IND-SH (control mean ± 3× standard deviation) was derived from 15 controls less than 25 weeks of age. No control exceeded this threshold, whereas in the same age range, IND-SH was observed at the proximal margins in 15% (7 of 46) of HSCR resections, up to 15 cm proximal to the aganglionic segment. No significant correlation was observed between IND-SH and length of or distance from the aganglionic segment, sex, trisomy 21, RET or SEMA3C/D polymorphisms, or clinical outcome, but analysis of more patients, with better long-term follow-up will be required to clarify the significance of this histological phenotype.

  14. On determinants of glomerular filtration rate after inhibition of proximal tubular reabsorption

    DEFF Research Database (Denmark)

    Leyssac, P P; Karlsen, F M; Holstein-Rathlou, N H

    1994-01-01

    The carbonic anhydrase inhibitor acetazolamide (ACZ) inhibits the absolute rate of proximal reabsorption (APR), causes a reduction in glomerular filtration rate (GFR), and activates the tubuloglomerular feedback mechanism (TGF) resulting in afferent vasoconstriction. The quantitative importance...... vasoconstriction seen after carbonic anhydrase inhibition fails to restore GFR to its control value. This is due to the high flow resistance in the distal nephron segments during the increased tubular flow rates seen after ACZ. The high distal flow resistance causes a parallel change in Pgc and Pprox and thus...

  15. Neural cell image segmentation method based on support vector machine

    Science.gov (United States)

    Niu, Shiwei; Ren, Kan

    2015-10-01

    In the analysis of neural cell images gained by optical microscope, accurate and rapid segmentation is the foundation of nerve cell detection system. In this paper, a modified image segmentation method based on Support Vector Machine (SVM) is proposed to reduce the adverse impact caused by low contrast ratio between objects and background, adherent and clustered cells' interference etc. Firstly, Morphological Filtering and OTSU Method are applied to preprocess images for extracting the neural cells roughly. Secondly, the Stellate Vector, Circularity and Histogram of Oriented Gradient (HOG) features are computed to train SVM model. Finally, the incremental learning SVM classifier is used to classify the preprocessed images, and the initial recognition areas identified by the SVM classifier are added to the library as the positive samples for training SVM model. Experiment results show that the proposed algorithm can achieve much better segmented results than the classic segmentation algorithms.

  16. Internal fixation of proximal humerus fractures using the T2-proximal humeral nail.

    Science.gov (United States)

    Popescu, Dragos; Fernandez-Valencia, Jenaro A; Rios, Moisés; Cuñé, Jordi; Domingo, Anna; Prat, Salvi

    2009-09-01

    Surgical management of proximal humerus fractures remains controversial and there is an increasing interest in intramedullary nailing. Created to improve previous designs, the T2-proximal humeral nail (PHN) (Stryker) has been recently released, and the English literature lacks a series evaluating its results. We present a clinical prospective study evaluating this implant for proximal humeral fractures. We evaluated the functional and radiological results and possible complications. Twenty-nine patients with displaced fractures of the proximal humerus were treated with this nail. One patient was lost right after surgery and excluded from the assessment. Eighteen patients were older than 70 years. There were 21 fractures of the proximal part of the humerus and 7 fractures that also involved the shaft; 15 of the fractures were two-part fractures (surgical neck), 5 were three-part fractures, and 1 was a four-part fracture. All fractures healed in a mean period of 2.7 months. There was one delayed union that healed in 4 months. One case of avascular necrosis of the humeral head was observed (a four-part fracture), but remained asymptomatic and did not require further treatment. In one case a back-out of one proximal screw was observed. A final evaluation with a minimum 1 year follow-up was performed by an independent observer; in 18 patients, the mean Constant score was 65.7 or 76.1% with the adjustment of age and gender; in 19 patients, the mean Oxford Shoulder Score was 21.7. The results obtained with the T2-PHN nail indicate that it represents a safe and reliable method in the treatment of two- and three-part fractures of the proximal humerus. The proximal fixation mechanism diminishes the rate of back-out of the screws, a frequent complication described in the literature. Better functional results were obtained from the patients younger than 70 years, but these were not statistically significant.

  17. Proximal tubular hypertrophy and enlarged glomerular and proximal tubular urinary space in obese subjects with proteinuria.

    Directory of Open Access Journals (Sweden)

    Ana Tobar

    Full Text Available BACKGROUND: Obesity is associated with glomerular hyperfiltration, increased proximal tubular sodium reabsorption, glomerular enlargement and renal hypertrophy. A single experimental study reported an increased glomerular urinary space in obese dogs. Whether proximal tubular volume is increased in obese subjects and whether their glomerular and tubular urinary spaces are enlarged is unknown. OBJECTIVE: To determine whether proximal tubules and glomerular and tubular urinary space are enlarged in obese subjects with proteinuria and glomerular hyperfiltration. METHODS: Kidney biopsies from 11 non-diabetic obese with proteinuria and 14 non-diabetic lean patients with a creatinine clearance above 50 ml/min and with mild or no interstitial fibrosis were retrospectively analyzed using morphometric methods. The cross-sectional area of the proximal tubular epithelium and lumen, the volume of the glomerular tuft and of Bowman's space and the nuclei number per tubular profile were estimated. RESULTS: Creatinine clearance was higher in the obese than in the lean group (P=0.03. Proteinuria was similarly increased in both groups. Compared to the lean group, the obese group displayed a 104% higher glomerular tuft volume (P=0.001, a 94% higher Bowman's space volume (P=0.003, a 33% higher cross-sectional area of the proximal tubular epithelium (P=0.02 and a 54% higher cross-sectional area of the proximal tubular lumen (P=0.01. The nuclei number per proximal tubular profile was similar in both groups, suggesting that the increase in tubular volume is due to hypertrophy and not to hyperplasia. CONCLUSIONS: Obesity-related glomerular hyperfiltration is associated with proximal tubular epithelial hypertrophy and increased glomerular and tubular urinary space volume in subjects with proteinuria. The expanded glomerular and urinary space is probably a direct consequence of glomerular hyperfiltration. These effects may be involved in the pathogenesis of obesity

  18. Direct volume estimation without segmentation

    Science.gov (United States)

    Zhen, X.; Wang, Z.; Islam, A.; Bhaduri, M.; Chan, I.; Li, S.

    2015-03-01

    Volume estimation plays an important role in clinical diagnosis. For example, cardiac ventricular volumes including left ventricle (LV) and right ventricle (RV) are important clinical indicators of cardiac functions. Accurate and automatic estimation of the ventricular volumes is essential to the assessment of cardiac functions and diagnosis of heart diseases. Conventional methods are dependent on an intermediate segmentation step which is obtained either manually or automatically. However, manual segmentation is extremely time-consuming, subjective and highly non-reproducible; automatic segmentation is still challenging, computationally expensive, and completely unsolved for the RV. Towards accurate and efficient direct volume estimation, our group has been researching on learning based methods without segmentation by leveraging state-of-the-art machine learning techniques. Our direct estimation methods remove the accessional step of segmentation and can naturally deal with various volume estimation tasks. Moreover, they are extremely flexible to be used for volume estimation of either joint bi-ventricles (LV and RV) or individual LV/RV. We comparatively study the performance of direct methods on cardiac ventricular volume estimation by comparing with segmentation based methods. Experimental results show that direct estimation methods provide more accurate estimation of cardiac ventricular volumes than segmentation based methods. This indicates that direct estimation methods not only provide a convenient and mature clinical tool for cardiac volume estimation but also enables diagnosis of cardiac diseases to be conducted in a more efficient and reliable way.

  19. Position sensors for segmented mirror

    Science.gov (United States)

    Rozière, Didier; Buous, Sébastien; Courteville, Alain

    2004-09-01

    There are currently several projects for giant telescopes with segmented mirrors under way. These future telescopes will have their primary mirror made of several thousand segments. The main advantage of segmentation is that it enables the active control of the whole mirror, so as to suppress the deformations of the support structure due to the wind, gravity, thermal inhomogeneities etc. ..., thus getting the best possible stigmatism. However, providing active control of segmented mirrors requires numerous accurate edges sensors. It is acknowledged that capacitance-based technology nowadays offers the best metrological performances-to-cost ratio. As the leader in capacitive technology, FOGALE nanotech offers an original concept which reduces the cost of instrumentation, sensors and electronics, while keeping a very high level of performances with a manufacturing process completely industrialised. We present here the sensors developed for the Segment Alignment Measurement System (SAMS) of the Southern African Large Telescope (SALT). This patented solution represents an important improvement in terms of cost, to market the Position Sensors for Segmented Mirrors of ELTs, whilst maintaining a very high performance level. We present here the concept, the laboratory qualification, and the first trials on the 7 central segments of SALT. The laboratory results are good, and we are now working on the on-site implementation to improve the immunity of the sensors to environment.

  20. A telomerase immortalized human proximal tubule cell line with a truncation mutation (Q4004X in polycystin-1.

    Directory of Open Access Journals (Sweden)

    Brittney-Shea Herbert

    Full Text Available Autosomal dominant polycystic kidney disease (ADPKD is associated with a variety of cellular phenotypes in renal epithelial cells. Cystic epithelia are secretory as opposed to absorptive, have higher proliferation rates in cell culture and have some characteristics of epithelial to mesenchymal transitions. In this communication we describe a telomerase immortalized cell line that expresses proximal tubule markers and is derived from renal cysts of an ADPKD kidney. These cells have a single detectable truncating mutation (Q4004X in polycystin-1. These cells make normal appearing but shorter cilia and fail to assemble polycystin-1 in the cilia, and less uncleaved polycystin-1 in membrane fractions. This cell line has been maintained in continuous passage for over 35 passages without going into senescence. Nephron segment specific markers suggest a proximal tubule origin for these cells and the cell line will be useful to study mechanistic details of cyst formation in proximal tubule cells.

  1. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  2. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

    We propose a method for the simultaneous construction of multiple image segmentations by combining a recently proposed “convolution of mixtures of Gaussians” model with a multi-layer hidden Markov random field structure. The resulting method constructs for a single image several, alternative...... segmentations that capture different structural elements of the image. We also apply the method to collections of images with identical pixel dimensions, which we call image stacks. Here it turns out that the method is able to both identify groups of similar images in the stack, and to provide segmentations...

  3. Endoscopic removal of a proximal urethral stent using a holmium laser: Case report and literature review

    Directory of Open Access Journals (Sweden)

    Francisco Botelho

    2012-01-01

    Full Text Available Urethral stents were initially developed for the management of urethral strictures and obstructive voiding disorders in select patients. Urethral stent complications are common and may require stent explantation, which is often quite challenging. We present our experience with endoscopic removal of an encrusted UroLume proximal urethral stent in a 72-year-old male using a holmium laser. The literature on various management options and outcomes for urethral stent removal is reviewed. Endoscopic removal of proximal urethral stents is feasible and safe and should be considered as the primary treatment option in patients requiring stent extraction.

  4. Changes in serum and intestinal diamine oxidase (DAO) activity after proximal enterectomy in rats. Correlation of DAO activity with mucosal mass parameters.

    Science.gov (United States)

    Buts, J P; Theys, S; De Keyser, N; Dive, C

    1989-09-01

    To determine whether serum and mucosal DAO activity reflects quantitative changes in the small bowel mucosal mass, we have chosen an experimental model of mucosal hyperplasia which is known to occur in the rat after enterectomy. A 50% proximal enterectomy or a single transection was performed in 20 growing rats weighing 145-160 g. Ten days following surgery, we determined mucosal mass parameters (weight, protein, and DNA content), sucrase activity, and DAO activity in the duodenum (segment A), proximal ileum (segment B), and distal ileum (segment C) of the remaining small intestine. Mucosal hyperplasia was demonstrated by the finding that in each segment, mucosal weight, protein, and DNA content per centimeter of gut length were significantly (P less than 0.01) higher (+38 to + 78%) in the resected group than in transected controls. In segments B and C of resected rats, the changes in DAO activity expressed per gram of mucosa paralleled the changes in mucosal mass, the activity being increased by +69% and +49% (P less than 0.05) compared to the values recorded in transected controls. Expressed per centimeter of gut length, total DAO activity was also enhanced by +141% in segment B (P less than 0.05 vs controls) and by +87% in segment C (P less than 0.01 vs controls) of resected rats. In the duodenum, the changes in DAO activity were small (+36%) and not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Early segmental changes in ischemic acute tubular necrosis of the rat kidney

    DEFF Research Database (Denmark)

    Faarup, Poul; Nørgaard, Tove; Hegedüs, Viktor

    2004-01-01

    and subsequent freeze-substitution in alcohol. The microscopic slides from the kidneys were silver methenamine-PAS stained. In the segments of the proximal convoluted tubules of the nephrons, presence of nuclear pyknosis, places of denuded basement membranes and presence of exfoliated tubular cells were counted...... versus the subsequent loops. The distribution of the structural lesions is in accordance with the previously reported presence of a tubulo-capillary counter-current flow in the proximal convoluted tubule and, when related to the highly variable oxygen tension in the normal renal cortex of the rat...

  6. SINA: A test system for proximity fuses

    Science.gov (United States)

    Ruizenaar, M. G. A.

    1989-04-01

    SINA, a signal generator that can be used for testing proximity fuses, is described. The circuitry of proximity fuses is presented; the output signal of the RF circuit results from a mixing of the emitted signal and received signal that is Doppler shifted in frequency by the relative motion of the fuse with respect to the reflecting target of surface. With SINA, digitized and stored target and clutter signals (previously measured) can be transformed to Doppler signals, for example during a real flight. SINA can be used for testing fuse circuitry, for example in the verification of results of computer simulations of the low frequency Doppler signal processing. The software of SINA and its use are explained.

  7. Tunable Magnetic Proximity Effects in Graphene Junctions

    Science.gov (United States)

    Lazic, Predrag; Belashchenko, Kirill; Zutic, Igor

    2015-03-01

    The characteristic length of the magnetic proximity effects exceed the thickness of a graphene layer leading to an important, but typically overlooked, modifications of equilibrium and transport properties, as well as the implications for graphene spintronics. Using the first-principles studies that integrate a real space density functional theory (GPAW) with the state-of-the art boundary elements electrostatic code based on the Robin Hood method, we explore tunable electronic structure and magnetic proximity effects in the ferromagnet/insulator/graphene junctions. We show that the inclusion of a finite-size gate electrodes and van der Walls interaction lead to nontrivial effects that could also be important in other two-dimensional materials beyond graphene. Work supported by US ONR, NSF-DMR and Nebraska NSF MRSEC.

  8. Management of Proximal Third Arm Replantation

    Directory of Open Access Journals (Sweden)

    Süleyman Taş

    2017-12-01

    Full Text Available Notwithstanding the recent success in major limb replantation achieved through the advancements in microsurgical techniques, the viability of the extremity is still relatively low at the transhumeral level following a replantation. There are no exact guidelines for deciding whether to undertake a stump repair or a replantation in such amputations at the proximal level. However, a highly motivated patient with realistic expectations and protected shoulder function can be a candidate to undergo replantation. The replanted arm may help the uninjured arm in daily activities. In this report we present the case of a 47-year-old man whose arm was amputated at proximal third level by an asphalt machine and successfully replanted together with the encountered problems and their solutions. The roadmap followed in this rare case may be a guide for hand surgeons.

  9. Dedifferentiated chondrosarcoma of right proximal femur

    Directory of Open Access Journals (Sweden)

    Sachin A Badge

    2016-01-01

    Full Text Available Dedifferentiated chondrosarcoma (DDCS comprises approximately 10% of all chondrosarcomas. The tumor generally occurs after the age of 50 years, with equal distribution among males and females. It is most often located in the bones of the pelvis, the proximal femur or humerus, the distal femur, and the ribs. Regardless of treatment, the prognosis is ominous with 90% of patients dying with distant metastases within 2 years. We report a case of DDCS of right proximal femur in a 73-year-old woman. The most important factors affecting survival are early recognition of the radiographic features, adequate histological sampling, and wide-margin resection of the lesion. So for the correct histopathological diagnosis the biopsy sample should be adequate to visualize both cartilaginous and noncartilaginous sarcomatous component which helps to increase the survival of patients before the distant metastasis occurs.

  10. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Justin J. Lee

    2017-10-01

    Full Text Available Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH, active vitamin D3, and fibroblast growth factor 23 (FGF23. The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms responsible for phosphate reclamation are well described, and emerging work is delineating the molecular identity of the paracellular shunt wherein calcium permeates the proximal tubular epithelium. Significant experimental work has delineated the molecular effects of PTH and FGF23 on these processes as well as their regulation of active vitamin D3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance.

  11. Active contours extension and similarity indicators for improved 3D segmentation of thyroid ultrasound images

    Science.gov (United States)

    Poudel, P.; Illanes, A.; Arens, C.; Hansen, C.; Friebe, M.

    2017-03-01

    Thyroid segmentation in tracked 2D ultrasound (US) using active contours has a low segmentation accuracy mainly due to the fact that smaller structures cannot be efficiently recognized and segmented. To address this issue, we propose a new similarity indicator with the main objective to provide information to the active contour algorithm concerning the regions that the active contour should continue to expand or should stop. First, a preprocessing step is carried out in order to attenuate the noise present in the US image and to increase its contrast, using histogram equalization and a median filter. In the second step, active contours are used to segment the thyroid in each 2D image of the dataset. After performing a first segmentation, two similarity indicators (ratio of mean square error, MSE and correlation between histograms) are computed at each contour point of the initial segmented thyroid between rectangles located inside and outside the obtained contour. A threshold is used on a final indicator computed from the other two indicators to find the probable regions for further segmentation using active contours. This process is repeated until no new segmentation region is identified. Finally, all the segmented thyroid images passed through a 3D reconstruction algorithm to obtain a 3D volume segmented thyroid. The results showed that including similarity indicators based on histogram equalization and MSE between inside and outside regions of the contour can help to segment difficult areas that active contours have problem to segment.

  12. A Hybrid 3D Learning-and-Interaction-based Segmentation Approach Applied on CT Liver Volumes

    Directory of Open Access Journals (Sweden)

    M. Danciu

    2013-04-01

    Full Text Available Medical volume segmentation in various imaging modalities using real 3D approaches (in contrast to slice-by-slice segmentation represents an actual trend. The increase in the acquisition resolution leads to large amount of data, requiring solutions to reduce the dimensionality of the segmentation problem. In this context, the real-time interaction with the large medical data volume represents another milestone. This paper addresses the twofold problem of the 3D segmentation applied to large data sets and also describes an intuitive neuro-fuzzy trained interaction method. We present a new hybrid semi-supervised 3D segmentation, for liver volumes obtained from computer tomography scans. This is a challenging medical volume segmentation task, due to the acquisition and inter-patient variability of the liver parenchyma. The proposed solution combines a learning-based segmentation stage (employing 3D discrete cosine transform and a probabilistic support vector machine classifier with a post-processing stage (automatic and manual segmentation refinement. Optionally, an optimization of the segmentation can be achieved by level sets, using as initialization the segmentation provided by the learning-based solution. The supervised segmentation is applied on elementary cubes in which the CT volume is decomposed by tilling, thus ensuring a significant reduction of the data to be classified by the support vector machine into liver/not liver. On real volumes, the proposed approach provides good segmentation accuracy, with a significant reduction in the computational complexity.

  13. Management of Acute Proximal Humeral Fractures.

    Science.gov (United States)

    Kancherla, Vamsi Krishna; Singh, Anshuman; Anakwenze, Oke A

    2017-01-01

    Proximal humeral fractures, which typically occur in elderly persons, are among the most common fractures. A myriad of nonsurgical and surgical treatment options exist for these injuries, including short-term immobilization and early physical therapy, percutaneous fixation, plate osteosynthesis, intramedullary nailing, hemiarthroplasty, and reverse shoulder arthroplasty. The choice of treatment depends on the fracture type and severity, surgeon expertise, patient age, and patient health status.

  14. Superconducting proximity effect in clean ferromagnetic layers

    OpenAIRE

    Zareyan, M.; Belzig, W.; Nazarov, Yu. V.

    2002-01-01

    We investigate the superconducting proximity effect in clean ferromagnetic layers with rough boundaries. The subgap density of states is formed by Andreev bound states at energies which depend on trajectory length and the ferromagnetic exchange field. At energies above the gap, the spectrum is governed by resonant scattering states. The resulting density of states, measurable by tunneling spectroscopy, exhibits a rich structure, which allows us to connect the theoretical parameters from exper...

  15. Alternating proximal algorithm for blind image recovery

    OpenAIRE

    Bolte, Jérôme; Combettes, Patrick Louis; Pesquet, Jean-Christophe

    2010-01-01

    International audience; We consider a variational formulation of blind image recovery problems. A novel iterative proximal algorithm is proposed to solve the associated nonconvex minimization problem. Under suitable assumptions, this algorithm is shown to have better convergence properties than standard alternating minimization techniques. The objective function includes a smooth convex data fidelity term and nonsmooth convex regularization terms modeling prior information on the data and on ...

  16. Transverse Stress Fracture of the Proximal Patella

    Science.gov (United States)

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu

    2016-01-01

    Abstract Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete. A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity. Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws. PMID:26871789

  17. Isolated Proximal Tibiofibular Dislocation during Soccer

    Directory of Open Access Journals (Sweden)

    Casey Chiu

    2015-01-01

    Full Text Available Proximal tibiofibular dislocations are rarely encountered in the Emergency Department (ED. We present a case involving a man presenting to the ED with left knee pain after making a sharp left turn on the soccer field. His physical exam was only remarkable for tenderness over the lateral fibular head. His X-rays showed subtle abnormalities of the tibiofibular joint. The dislocation was reduced and the patient was discharged from the ED with orthopedic follow-up.

  18. Capacitive Proximity Sensor Has Longer Range

    Science.gov (United States)

    Vranish, John M.

    1992-01-01

    Capacitive proximity sensor on robot arm detects nearby object via capacitive effect of object on frequency of oscillator. Sensing element part of oscillator circuit operating at about 20 kHz. Total capacitance between sensing element and ground constitutes tuning capacitance of oscillator. Sensor circuit includes shield driven by replica of alternating voltage applied to sensing element. Driven shield concentrates sensing electrostatic field in exterior region to enhance sensitivity to object. Sensitivity and dynamic range has corresponding 12-to-1 improvement.

  19. THE PROXIMATE COMPOSITION OF AFRICAN BUSH MANGO ...

    African Journals Online (AJOL)

    BIG TIMMY

    The proximate analysis (moisture, crude protein, crude fat, mineral ash and total carbohydrates) in the kernels and flour of African Bush Mango (. ) were investigated. The results revealed that the kernels contained moisture (2.5 g/100 g), crude protein (8.9 g/100 g), crude fat (68.4 g/100 g), mineral ash (2.3 g/100 g) and total ...

  20. [Proximity and breastfeeding at the maternity hospital].

    Science.gov (United States)

    Fradin-Charrier, Anne-Claire

    2015-01-01

    The establishment of breastfeeding, as well as its duration, are facilitated through the proximity of the mother with her new baby. However, in maternity hospitals, breastfeeding mothers very often leave their baby in the nursery at night time. A study carried out in 2014 in several maternity hospitals put forward suggestions and highlighted areas to improve in everyday practice. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Learning lateral interactions for feature binding and sensory segmentation from prototypic basis interactions.

    Science.gov (United States)

    Weng, Sebastian; Wersing, Heiko; Steil, Jochen J; Ritter, Helge

    2006-07-01

    We present a hybrid learning method bridging the fields of recurrent neural networks, unsupervised Hebbian learning, vector quantization, and supervised learning to implement a sophisticated image and feature segmentation architecture. This architecture is based on the competitive layer model (CLM), a dynamic feature binding model, which is applicable on a wide range of perceptual grouping and segmentation problems. A predefined target segmentation can be achieved as attractor states of this linear threshold recurrent network, if the lateral weights are chosen by Hebbian learning. The weight matrix is given by the correlation matrix of special pattern vectors with a structure dependent on the target labeling. Generalization is achieved by applying vector quantization on pair-wise feature relations, like proximity and similarity, defined by external knowledge. We show the successful application of the method to a number of artifical test examples and a medical image segmentation problem of fluorescence microscope cell images.

  2. An iterative method for airway segmentation using multiscale leakage detection

    Science.gov (United States)

    Nadeem, Syed Ahmed; Jin, Dakai; Hoffman, Eric A.; Saha, Punam K.

    2017-02-01

    There are growing applications of quantitative computed tomography for assessment of pulmonary diseases by characterizing lung parenchyma as well as the bronchial tree. Many large multi-center studies incorporating lung imaging as a study component are interested in phenotypes relating airway branching patterns, wall-thickness, and other morphological measures. To our knowledge, there are no fully automated airway tree segmentation methods, free of the need for user review. Even when there are failures in a small fraction of segmentation results, the airway tree masks must be manually reviewed for all results which is laborious considering that several thousands of image data sets are evaluated in large studies. In this paper, we present a CT-based novel airway tree segmentation algorithm using iterative multi-scale leakage detection, freezing, and active seed detection. The method is fully automated requiring no manual inputs or post-segmentation editing. It uses simple intensity based connectivity and a new leakage detection algorithm to iteratively grow an airway tree starting from an initial seed inside the trachea. It begins with a conservative threshold and then, iteratively shifts toward generous values. The method was applied on chest CT scans of ten non-smoking subjects at total lung capacity and ten at functional residual capacity. Airway segmentation results were compared to an expert's manually edited segmentations. Branch level accuracy of the new segmentation method was examined along five standardized segmental airway paths (RB1, RB4, RB10, LB1, LB10) and two generations beyond these branches. The method successfully detected all branches up to two generations beyond these segmental bronchi with no visual leakages.

  3. Proximal Gastrojejunal Reconstruction after Pancreaticoduodenal Resection

    Directory of Open Access Journals (Sweden)

    M. Wayne

    2012-01-01

    Full Text Available Introduction. Reconstruction by proximal gastrojejunostomy, and distal biliary and pancreatic anastomoses is infrequently used after resection of the head of the pancreas because of fear of fistulas and cholangitis. Pancreaticoduodenectomy is being performed more frequently for cystic malignant and premalignant lesions. Because of this there is a need for endoscopic visualization and biopsy of the residual pancreatic duct, since multi-centricity is characteristic of some of these malignancies. Since endoscopic access of the bile duct and pancreatic duct is difficult and unsuccessful in 50–70% after B II or Roux Y reconstruction, we prospectively studied the merit and complications (early and late of proximal gastrojejunal (PGJ reconstruction after pancreaticoduodenal resection. Material and Methods. Thirty nine consecutive, non-radomized patients underwent pancreaticoduodenectomy and PGJ reconstruction over 14 mos. There were 21 males and 18 females. Results. 7 patients with IPMN have undergone repeat CT scanning for surveillance, with 3 requiring repeat EUS and ERCP. There were no technical difficulties accessing the pancreas or the pancreatic duct, supporting the PGJ reconstruction. Conclusion. Proximal gastrojejunal reconstruction following pancreaticoduodenal resection may be safely done with similar morbidity to traditional pancreaticojejunal reconstructions. PGJ reconstruction may be of greater value when direct visual access to the bile duct or pancreatic duct is necessary, and should be considered when doing resection for mucinous cysts or IPMN of the head of the pancreas.

  4. Bilateral, atraumatic, proximal tibiofibular joint instability.

    Science.gov (United States)

    Morrison, Troy D; Shaer, James A; Little, Jill E

    2011-01-01

    Dislocation of the tibiofibular joint is rare and usually results from a traumatic event. Only 1 case of atraumatic proximal tibiofibular joint instability in a 14-year-old girl has been reported in the literature, however this condition might occur more frequently than once thought. A wide range of treatment options exist for tibiofibular dislocations. Currently, the first choice is a conservative approach, and when this fails, surgical means such as resection of the fibula head, arthrodesis, and reconstruction are considered. However, no consensus exists on the most effective treatment. This article reports a unique case of bilateral, atraumatic, proximal tibia and fibular joint instability involving a 30-year-old man with a 20-year history of pain and laxity in the right knee. The patient had no trauma to his knees; he reported 2 immediate family members with similar complaints, which suggests that this case is likely congenital. After conservative approaches proved to be ineffective, the patient underwent capsular reconstruction using free autologous gracilis tendon. At 6-month postoperative follow-up, the patient was pain free with no locking and instability. He then underwent surgery on the left knee. At 1-year follow-up after the second surgery, the patient had no symptoms or restrictions in mobility. We provide an alternative surgical approach to arthrodesis and resection for the treatment of chronic proximal tibiofibular instability. In the treatment of chronic tibiofibular instability, we believe that reconstruction of the tibiofibular joint is a safe and effective choice. Copyright 2011, SLACK Incorporated.

  5. Metrology of IXO Mirror Segments

    Science.gov (United States)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  6. An exact algorithm for generating homogenous two-segment cutting patterns

    Science.gov (United States)

    Cui, Y.

    2007-04-01

    An exact algorithm is proposed for generating homogenous two-segment patterns for the constrained two-dimensional guillotine-cutting problems of rectangular items. It is a bottom-up approach combined with branch-and-bound techniques. The stock plate is divided into two segments. Each segment consists of strips of the same length and direction. Only homogenous strips are considered, each of which contains items of the same type. The strip directions of the two segments may be either the same or perpendicular to each other. The algorithm uses a tree-search procedure. It starts from an initial lower bound, implicitly generates all possible segments through the assembly of strips, and constructs possible patterns through the combination of two segments. Tighter bounds are established to discard non-promising segments. The computational results indicate that the algorithm is efficient both in computation time and in material utilization, and is able to deal with relatively large-scale problems.

  7. Missed posterior shoulder dislocation with malunited proximal humerus fracture

    Directory of Open Access Journals (Sweden)

    Kumar Sunil

    2013-12-01

    Full Text Available 【Abstract】Posterior dislocation of the shoulder may be missed or neglected at initial presentation especially in developing countries. We present a case of 40-year-old In- dian man who had 3-month missed posterior dislocation of the right shoulder along with malunited fracture of the ana- tomical neck of the humerus. Open reduction and stabiliza- tion with modified McLaughlin procedure was performed. Rotational osteotomy of proximal humerus had to be per- formed as supplementary procedure to keep the humeral head stable in glenoid cavity during functional range of movements. The patient had excellent result of the shoulder at 3 years follow-up. Key words: Shoulder dislocation; Humerus; Osteotomy

  8. Complications following dislocations of the proximal interphalangeal joint.

    Science.gov (United States)

    Mangelson, John J; Stern, Peter J; Abzug, Joshua M; Chang, James; Osterman, A Lee

    2014-01-01

    Dorsal fracture-dislocations of the proximal interphalangeal joint are challenging injuries to treat and are associated with many complications. The determination of stability is crucial to appropriate management. Stable injuries can usually be treated nonsurgically, whereas unstable injuries typically require surgical stabilization. Many surgical techniques have been used, including extension block pinning, volar plate arthroplasty, open reduction and internal fixation, external fixation, and hemihamate autografting. Because stiffness and flexion contracture are frequent complications, every effort should be made to initiate early motion while maintaining concentric reduction. Other complications include redislocation, chronic swelling, swan neck and coronal plane deformities, and pin tract infections. Assessing injury characteristics, including chronicity, the percentage of articular surface fractured, and the degree of comminution, and understanding complications will help in determining the most appropriate treatment. Chronic dislocations and those injuries in which painful arthritis develops can be successfully treated with salvage procedures, including arthroplasty and arthrodesis.

  9. Single Level Proximal Thoracic Pedicle Subtraction Osteotomy for Fixed Hyperkyphotic Deformity: Surgical Technique and Patient Series.

    Science.gov (United States)

    Obeid, Ibrahim; Diebo, Bassel G; Boissiere, Louis; Bourghli, Anouar; Cawley, Derek T; Larrieu, Daniel; Pointillart, Vincent; Challier, Vincent; Vital, Jean Marc; Lafage, Virginie

    2017-07-22

    Thoracic hyperkyphosis can display pathological deterioration, resulting in either hyperlordotic cervical compensation or sagittal malalignment. Various techniques have been described to treat fixed malalignment. Pedicle subtraction osteotomy (PSO) is commonly used in the lumbar spine and frequently limited to the distal thoracic spine. This series focuses on the surgical specificities of proximal thoracic PSO, with clinical and radiological outcomes. To report the surgical specificities and assess the clinical and radiological outcomes of proximal thoracic osteotomies for correction of rigid kyphotic deformities. This is a retrospective review of 10 consecutive patients who underwent single level proximal thoracic PSO (T2-T5). Preoperative and postoperative full-body EOS TM radiographs, perioperative data, and complications were recorded. The surgical technique and its nuances were described in detail. Patients had mean age of 41.8 yr and 50% were female. The technique provided correction of segmental and global kyphosis, 26.6° and 29.5°, respectively. Patients reported reciprocal reduction in C2-C7 cervical lordosis (37.6°-18.6°, P  hyperkyphosis (R = 0.840, P  = .002). Mean operative time was 291 min, blood loss 1650 mL, and mean hospital stay was 13.8 d. Three patients reported complications that were resolved, including 1 patient who was revised because of a painful cross link. There were no neurological complications, pseudarthroses, instrumentation breakage, or wound infections at a minimum of 2-yr follow-up. Proximal thoracic PSO can be a safe and effective technique to treat fixed proximal thoracic hyperkyphosis leading to kyphosis reduction and craniocervical relaxation.

  10. Calibrating animal-borne proximity loggers.

    Science.gov (United States)

    Rutz, Christian; Morrissey, Michael B; Burns, Zackory T; Burt, John; Otis, Brian; St Clair, James J H; James, Richard

    2015-06-01

    Growing interest in the structure and dynamics of animal social networks has stimulated efforts to develop automated tracking technologies that can reliably record encounters in free-ranging subjects. A particularly promising approach is the use of animal-attached 'proximity loggers', which collect data on the incidence, duration and proximity of spatial associations through inter-logger radio communication. While proximity logging is based on a straightforward physical principle - the attenuation of propagating radio waves with distance - calibrating systems for field deployment is challenging, since most study species roam across complex, heterogeneous environments.In this study, we calibrated a recently developed digital proximity-logging system ('Encounternet') for deployment on a wild population of New Caledonian crows Corvus moneduloides. Our principal objective was to establish a quantitative model that enables robust post hoc estimation of logger-to-logger (and, hence, crow-to-crow) distances from logger-recorded signal-strength values. To achieve an accurate description of the radio communication between crow-borne loggers, we conducted a calibration exercise that combines theoretical analyses, field experiments, statistical modelling, behavioural observations, and computer simulations.We show that, using signal-strength information only, it is possible to assign crow encounters reliably to predefined distance classes, enabling powerful analyses of social dynamics. For example, raw data sets from field-deployed loggers can be filtered at the analysis stage to include predominantly encounters where crows would have come to within a few metres of each other, and could therefore have socially learned new behaviours through direct observation. One of the main challenges for improving data classification further is the fact that crows - like most other study species - associate across a wide variety of habitats and behavioural contexts, with different signal

  11. Segmentation and Quantification for Angle-Closure Glaucoma Assessment in Anterior Segment OCT.

    Science.gov (United States)

    Fu, Huazhu; Xu, Yanwu; Lin, Stephen; Zhang, Xiaoqin; Wong, Damon Wing Kee; Liu, Jiang; Frangi, Alejandro F; Baskaran, Mani; Aung, Tin

    2017-09-01

    Angle-closure glaucoma is a major cause of irreversible visual impairment and can be identified by measuring the anterior chamber angle (ACA) of the eye. The ACA can be viewed clearly through anterior segment optical coherence tomography (AS-OCT), but the imaging characteristics and the shapes and locations of major ocular structures can vary significantly among different AS-OCT modalities, thus complicating image analysis. To address this problem, we propose a data-driven approach for automatic AS-OCT structure segmentation, measurement, and screening. Our technique first estimates initial markers in the eye through label transfer from a hand-labeled exemplar data set, whose images are collected over different patients and AS-OCT modalities. These initial markers are then refined by using a graph-based smoothing method that is guided by AS-OCT structural information. These markers facilitate segmentation of major clinical structures, which are used to recover standard clinical parameters. These parameters can be used not only to support clinicians in making anatomical assessments, but also to serve as features for detecting anterior angle closure in automatic glaucoma screening algorithms. Experiments on Visante AS-OCT and Cirrus high-definition-OCT data sets demonstrate the effectiveness of our approach.

  12. Proximate chemical composition and fatty acid profiles of ...

    African Journals Online (AJOL)

    Proximate chemical composition and fatty acid profiles of Longissimus Proximate chemical composition and fatty acid profiles of Longissimus thoracis from pasture fed LHRH immunocastrated, castrated and intact Bos indicus bulls.

  13. Proximate Analysis and Total Lycopene Content of Some Tomato ...

    African Journals Online (AJOL)

    MBI

    2017-06-05

    Jun 5, 2017 ... Standard analytical techniques were employed to determine the proximate composition and lycopene content of three tomato cultivars namely: ... Keywords: Antioxidant, lycopene content, proximate composition, tomato cultivars. INTRODUCTION ..... from oranges, tomatoes and carrots. African. Journal of ...

  14. A Regularized Algorithm for the Proximal Split Feasibility Problem

    Directory of Open Access Journals (Sweden)

    Zhangsong Yao

    2014-01-01

    Full Text Available The proximal split feasibility problem has been studied. A regularized method has been presented for solving the proximal split feasibility problem. Strong convergence theorem is given.

  15. Fast segmentation of kidney components using random forests and ferns.

    Science.gov (United States)

    Jin, Chao; Shi, Fei; Xiang, Dehui; Zhang, Lichun; Chen, Xinjian

    2017-12-01

    This paper studies the feasibility of developing a fast and accurate automatic kidney component segmentation method. The proposed method segments the kidney into four components: renal cortex, renal column, renal medulla, and renal pelvis. In this article, we have proposed a highly efficient approach which strategically combines random forests and random ferns methods to segment the kidney into four components: renal cortex, renal column, renal medulla, and renal pelvis. The proposed method is designed following a coarse-to-fine strategy. The initial segmentation applies random forests and random ferns with a variety of features, and combines their results to obtain a coarse renal cortex region. Then the fine segmentation of four kidney components is achieved using the weighted forests-ferns approach with the well-designed potential energy features which are calculated based on the initial segmentation result. The proposed method was validated on a dataset with 37 contrast-enhanced CT images. Evaluation indices including Dice similarity coefficient (DSC), true positive volume fraction (TPVF), and false positive volume fraction (FPVF) are used to assess the segmentation accuracy. The proposed method was implemented and tested on a 64-bit system computer (Intel Core i7-3770 CPU, 3.4 GHz and 8 GB RAM). The experimental results demonstrated the high accuracy and efficiency for segmenting the kidney components: the mean Dice similarity coefficients were 89.85%, 80.60%, 86.63%, and 77.75% for renal cortex, column, medulla, and pelvis, respectively, for right and left kidneys. The computational time of segmenting the whole kidney into four components was about 3 s. The experimental results showed the feasibility and efficacy of the proposed automatic kidney component segmentation method. The proposed method applied an efficient weighted strategy to combine random forests and ferns, making full use of the advantages of both methods. The novel potential energy features help

  16. Detecting Proximal Secondary Caries Lesions: A Cost-effectiveness Analysis.

    Science.gov (United States)

    Schwendicke, F; Brouwer, F; Paris, S; Stolpe, M

    2016-02-01

    When choosing detection methods for secondary caries lesions, dentists need to weigh sensitivity, allowing early initiation of retreatments to avoid lesion progression, against specificity, aiming to reduce risks of false-positive diagnoses and invasive overtreatments. We assessed the cost-effectiveness of different detection methods for proximal secondary lesions using Monte Carlo microsimulations. A vital permanent molar with an occlusal-proximal restoration was simulated over the lifetime of an initially 20-y-old. Three methods were compared: biannual tactile detection, radiographic detection every 2 y, and biannual laser fluorescence detection. Methods were employed either on their own or in pairwise combinations at sensitive and specific thresholds estimated with systematically collected data. A mixed public-private payer perspective in the context of German health care was applied. Effectiveness was calculated as years of tooth retention. Net-benefit analyses were used to evaluate cost-effectiveness acceptability at different willingness-to-pay thresholds. Radiographic detection verified by tactile assessment (both at specific thresholds) was least costly (mean, 1,060 euros) but had limited effectiveness (mean retention time, 50 y). The most effective but also more costly combination was laser fluorescence detection verified by radiography, again at specific thresholds (1157 euros, 53 y, acceptable if willingness to pay >32 euro/y). In the majority of simulations, not combining detection methods or applying them at sensitive thresholds was less effective and more costly. Net benefits were not greatly altered by applying different discounting rates or using different baseline prevalence of secondary lesions. Current detection methods for secondary lesions should best be used in combination, not on their own, at specific thresholds to avoid false-positive diagnoses leading to costly and invasive overtreatment. The relevant characteristics, such as predictive

  17. Proximity Online Media in Catalonia (Spain. The Case Study of Nació Digital Group

    Directory of Open Access Journals (Sweden)

    Mònica Puntí Brun

    2015-04-01

    Full Text Available This paper aims to make a conceptualization of proximity digital media. It will define what is local and proximity communication as well as the history and evolution of online journalism and digital media features which are briefly reviewed. Business models that exist nowadays and the state of art in Catalonia (Spain will also be briefly analysed. From this theoretical framework it will be explained the case of Nació Digital and its territorial media. Initially the history of this media group will be developed, as well as its journalistic and business models. The paper seeks to underscore the importance of the journalistic model based on the tradition of the profession, the proximity information and the technology developed for this online media. The Nació Digital is an example of a successful media outlet judging from its audience figures (the second online media in Catalonia and its sustainable model business.

  18. Level-Set Based Carotid Artery Segmentation for Stenosis Grading

    NARCIS (Netherlands)

    van Bemmel, C.M.; Spreeuwers, Lieuwe Jan; Viergever, M.A.; Niessen, W.J.

    2002-01-01

    A semi-automated method is presented for the determination of the degree of stenosis of the internal carotid artery (ICA) in 3D contrast-enhanced (CE) MR angiograms. Hereto, we determined the central vessel axis (CA), which subsequently is used as an initialization for a level-set based segmentation

  19. Instructional format and segment length in interactive video programs

    NARCIS (Netherlands)

    Verhagen, Pleunes Willem; Breman, Jeroen; Breman, Jeroen; Simonson, Michael R.; Anderson, Mary Lagomarcino

    1995-01-01

    The purpose of this study was to gather further insight into a previous investigation of the relationship between self-chosen and program-controlled segment length of an interactive videodisk program, and performance on post- and retention tests. The initial study by Verhagen, which questioned what

  20. The regional dimension of intergenerational proximity in the Netherlands

    NARCIS (Netherlands)

    van der Pers, Marieke; Mulder, Clara H.

    Previous research has shown the impact of individual characteristics on intergenerational proximity but has largely ignored the regional dimension of such proximity. In this paper, we examine the regional variation in intergenerational proximity in the Netherlands. We address this issue by

  1. Quality Assessment and Proximate Analysis of Amaranthus hybridus ...

    African Journals Online (AJOL)

    The aim of this research is to determine the quality and proximate composition of Amaranthus hybridus, Celosia argentea, and Talinum triangulare obtained from open markets in Benin City, Nigeria. Microbiological and proximate analysis were carried out using standard methods. Results of the proximate analysis revealed ...

  2. Proximal femur geometry in the adult Kenyan femur and its ...

    African Journals Online (AJOL)

    Background: Numerous orthopaedic procedures are carried out on the proximal femur. For optimal hip function, these procedures must restore the anatomy of the proximal femur to as near normal as possible. There are currently no local studies that have described in detail the normal anatomy of the proximal femur and its ...

  3. Optimal graph based segmentation using flow lines with application to airway wall segmentation

    DEFF Research Database (Denmark)

    Petersen, Jens; Nielsen, Mads; Lo, Pechin Chien Pau

    2011-01-01

    This paper introduces a novel optimal graph construction method that is applicable to multi-dimensional, multi-surface segmentation problems. Such problems are often solved by refining an initial coarse surface within the space given by graph columns. Conventional columns are not well suited...... for surfaces with high curvature or complex shapes but the proposed columns, based on properly generated flow lines, which are non-intersecting, guarantee solutions that do not self-intersect and are better able to handle such surfaces. The method is applied to segment human airway walls in computed tomography...... images. Comparison with manual annotations on 649 cross-sectional images from 15 different subjects shows significantly smaller contour distances and larger area of overlap than are obtained with recently published graph based methods. Airway abnormality measurements obtained with the method on 480 scan...

  4. Minimally Invasive Fixation for Proximal Humeral Fracture: A Review on the use of T2 Proximal Humeral Nail

    Directory of Open Access Journals (Sweden)

    Sze-Ling Iris Ngai

    2013-12-01

    Discussion and conclusion: With the proper surgical technique high union rate, good functional recovery, and low complication rate can be achieved by using T2 Proximal Humeral Nail in managing traumatic proximal humeral fracture.

  5. Heteromeric Kv7.2/7.3 channels differentially regulate action potential initiation and conduction in neocortical myelinated axons.

    Science.gov (United States)

    Battefeld, Arne; Tran, Baouyen T; Gavrilis, Jason; Cooper, Edward C; Kole, Maarten H P

    2014-03-05

    Rapid energy-efficient signaling along vertebrate axons is achieved through intricate subcellular arrangements of voltage-gated ion channels and myelination. One recently appreciated example is the tight colocalization of K(v)7 potassium channels and voltage-gated sodium (Na(v)) channels in the axonal initial segment and nodes of Ranvier. The local biophysical properties of these K(v)7 channels and the functional impact of colocalization with Na(v) channels remain poorly understood. Here, we quantitatively examined K(v)7 channels in myelinated axons of rat neocortical pyramidal neurons using high-resolution confocal imaging and patch-clamp recording. K(v)7.2 and 7.3 immunoreactivity steeply increased within the distal two-thirds of the axon initial segment and was mirrored by the conductance density estimates, which increased from ~12 (proximal) to 150 pS μm(-2) (distal). The axonal initial segment and nodal M-currents were similar in voltage dependence and kinetics, carried by K(v)7.2/7.3 heterotetramers, 4% activated at the resting membrane potential and rapidly activated with single-exponential time constants (~15 ms at 28 mV). Experiments and computational modeling showed that while somatodendritic K(v)7 channels are strongly activated by the backpropagating action potential to attenuate the afterdepolarization and repetitive firing, axonal K(v)7 channels are minimally recruited by the forward-propagating action potential. Instead, in nodal domains K(v)7.2/7.3 channels were found to increase Na(v) channel availability and action potential amplitude by stabilizing the resting membrane potential. Thus, K(v)7 clustering near axonal Na(v) channels serves specific and context-dependent roles, both restraining initiation and enhancing conduction of the action potential.

  6. Perceptual filling-in of a line segment presented on only one side of the blind spot.

    Science.gov (United States)

    Araragi, Yukyu; Ito, Hiroyuki; Sunaga, Shoji

    2009-01-01

    Two experiments examined whether filling-in occurred at the blind spot when a line segment was presented on only one side of the blind spot. We used static and dynamic stimuli: a static test line segment and a pair of probe line segments were presented in Experiment 1 and a moving test line segment was presented in Experiment 2. We compared the probability that the proximal end was perceived to be on the blind spot side when the test line segment came into contact with the blind spot (blind spot condition) with that when the test line segment was outside the blind spot (control condition). The results of the two experiments showed that the proximal end was perceived to be more on the blind spot side in the blind spot condition than in the control condition. Notably, when a dynamic stimulus was presented below the blind spot, the mean amount of filling-in reached 2.84 degrees. Therefore, filling-in occurred at the blind spot even when a line segment was presented on only one side of the blind spot.

  7. Automated segmentation of muscle fiber images using active contour models.

    Science.gov (United States)

    Klemencic, A; Kovacic, S; Pernus, F

    1998-08-01

    The cross-sectional area of different fiber types is an important anatomic feature in studying the structure and function of healthy and diseased human skeletal muscles. However, such studies are hampered by the thousands of fibers involved when manual segmentation has to be used. We have developed a semiautomatic segmentation method that uses computational geometry and recent computer vision techniques to significantly reduce the time required to accurately segment the fibers in a sample. The segmentation is achieved by simply pointing to the approximate centroid of each fiber. The set of centroids is then used to automatically construct the Voronoi polygons, which correspond to individual fibers. Each Voronoi polygon represents the initial shape of one active contour model, called a snake. In the energy minimization process, which is executed in several stages, different external forces and problem-specific knowledge are used to guide the snakes to converge to fiber boundaries. Our results indicate that this approach for segmenting muscle fiber images is fast, accurate, and reproducible compared with manual segmentation performed by experts.

  8. An efficient neural network based method for medical image segmentation.

    Science.gov (United States)

    Torbati, Nima; Ayatollahi, Ahmad; Kermani, Ali

    2014-01-01

    The aim of this research is to propose a new neural network based method for medical image segmentation. Firstly, a modified self-organizing map (SOM) network, named moving average SOM (MA-SOM), is utilized to segment medical images. After the initial segmentation stage, a merging process is designed to connect the objects of a joint cluster together. A two-dimensional (2D) discrete wavelet transform (DWT) is used to build the input feature space of the network. The experimental results show that MA-SOM is robust to noise and it determines the input image pattern properly. The segmentation results of breast ultrasound images (BUS) demonstrate that there is a significant correlation between the tumor region selected by a physician and the tumor region segmented by our proposed method. In addition, the proposed method segments X-ray computerized tomography (CT) and magnetic resonance (MR) head images much better than the incremental supervised neural network (ISNN) and SOM-based methods. © 2013 Published by Elsevier Ltd.

  9. Blunt traumatic aortic rupture of the proximal ascending aorta repaired by resection and direct anastomosis.

    Science.gov (United States)

    Harmouche, Majid; Slimani, Eric Karim; Heraudeau, Adeline; Verhoye, Jean-Philippe

    2013-10-01

    Traumatic aortic injury represents 15% of motor vehicle related deaths with death occurring at the scene in 85% of the cases. Aortic disruptions usually occur at the isthmus in a transverse fashion with all three of the aortic layers being involved. Herein, we report the case of a 68-year old man with no prior medical history who was struck by a vehicle while riding his bicycle. The ruptured segment of aorta was resected circumferentially and interrupted horizontal mattress pledgeted prolene sutures were used to ensure full thickness aortic integrity of the proximal and distal aortic segments. The aorta was closed with a single-layer technique using 4/0 prolene suture. There were no postoperative complications and patient was discharged on Day 44. The case here discussed demonstrates a rare presentation of blunt aortic injury. The proximal ascending aorta is an unusual site of transection following blunt trauma with few reports in the literature. We were able to repair the aorta with direct suture, thus avoiding the use of artificial material.

  10. Segmented Capacitance Sensor with Partially Released Inactive Segments

    Directory of Open Access Journals (Sweden)

    Lev Jakub

    2015-09-01

    Full Text Available Material throughput measurement is important for many applications, for example yield maps creation or control of mass flow in stationary lines. Quite perspective can be the capacitive throughput method. Segmented capacitance sensor (SCS is discussed in this paper. SCS is a compromise between simple capacitive throughput sensors and electrical capacitance tomography sensors. The SCS variant with partially released inactive segments is presented. The mathematical model of SCS was created and verified by measurements. A good correspondence between measured and computed values was found and it can be stated that the proposed mathematical model was verified. During measurement the voltage values on the inactive segments were monitored as well. On the basis of the measurement there was found that these values are significantly influenced by material distribution.

  11. Methods of evaluating segmentation characteristics and segmentation of major faults

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kie Hwa; Chang, Tae Woo; Kyung, Jai Bok [Seoul National Univ., Seoul (Korea, Republic of)] (and others)

    2000-03-15

    Seismological, geological, and geophysical studies were made for reasonable segmentation of the Ulsan fault and the results are as follows. One- and two- dimensional electrical surveys revealed clearly the fault fracture zone enlarges systematically northward and southward from the vicinity of Mohwa-ri, indicating Mohwa-ri is at the seismic segment boundary. Field Geological survey and microscope observation of fault gouge indicates that the Quaternary faults in the area are reactivated products of the preexisting faults. Trench survey of the Chonbuk fault Galgok-ri revealed thrust faults and cumulative vertical displacement due to faulting during the late Quaternary with about 1.1-1.9 m displacement per event; the latest event occurred from 14000 to 25000 yrs. BP. The seismic survey showed the basement surface os cut by numerous reverse faults and indicated the possibility that the boundary between Kyeongsangbukdo and Kyeongsannamdo may be segment boundary.

  12. Delayed homicides and the proximate cause.

    Science.gov (United States)

    Lin, Peter; Gill, James R

    2009-12-01

    Delayed homicides result from complications of remote injuries inflicted by "the hands of another." The investigation of delayed homicides may be a challenge due to a number of factors including: failure to report the death to the proper authorities, lack of ready and adequate documentation of the original injury and circumstances, and jurisdictional differences between the places of injury and death. The certification of these deaths also requires the demonstration of a pathophysiologic link between the remote injury and death. In sorting through these issues, it is helpful to rely upon the definition of the proximate cause of death. Over a 2-year period in New York City, there were 1211 deaths certified as homicide of which 42 were due to injuries sustained greater than 1 year before death. The survival interval ranged from 1.3 to 43.2 years. The most common immediate causes of death were: infections (22), seizures (7), and intestinal obstructions/hernias (6). Common patterns of complications included infection following a gunshot wound of the spinal cord, seizure disorder due to blunt head trauma, and intestinal obstruction/hernia due to adhesions from an abdominal stab wound. Spinal cord injuries resulted in paraplegia in 14 instances and quadriplegia in 8. The mean survival interval for paraplegics was 20.3 years and 14.8 years for quadriplegics; infections were a frequent immediate cause of death in both groups, particularly infections due to chronic bladder catheterization. The definition of proximate cause originated with civil law cases and was later applied to death certification as the proximate cause of death. The gradual extinction of the "year and a day rule" for the limitation of bringing homicide charges in delayed deaths may result in more of these deaths going to trial. Medical examiners/coroners must be able to explain the reasoning behind these death certifications and maintain consistent standards for the certification of all delayed deaths due

  13. Laparoscopic proximal gastrectomy with oblique jejunogastrostomy.

    Science.gov (United States)

    Tanaka, Kimitaka; Ebihara, Yuma; Kurashima, Yo; Nakanishi, Yoshitsugu; Asano, Toshimichi; Noji, Takehiro; Murakami, Soichi; Nakamura, Toru; Tsuchikawa, Takahiro; Okamura, Keisuke; Shichinohe, Toshiaki; Hirano, Satoshi

    2017-05-10

    Proximal early gastric cancer is a good indication for totally laparoscopic proximal gastrectomy (TLPG) with double-tract reconstruction (DTR). However, when most of the dietary intake passes through the escape route of the jejunum, the functional benefits of proximal gastrectomy might be similar to those after total gastrectomy. Our DTR procedure was improved for easy passage through the remnant stomach. The purposes of this study were to present a novel technique for intracorporeal DTR using linear staplers after TLPG and to investigate surgical outcomes. DTR was performed using linear staplers only. A side-to-side jejunogastrostomy with twisting of both the remnant stomach and the anal jejunum was performed for the purpose of passing meals through the remnant stomach (an oblique jejunogastrostomy technique). The ten patients who underwent TLPG with DTR from January 2011 to August 2016 in Hokkaido University Hospital were retrospectively reviewed. Their clinicopathological characteristics and surgical and postoperative outcomes were collected and analyzed. The median duration of operation was 285 (range 146-440) min. No patients required blood transfusions. The number of dissected lymph nodes was 32 (range 22-56). There were no intraoperative complications, and no cases were converted to open surgery. All the patients were pT1N0M0 stage IA. No anastomotic leakage or complications were detected. Postoperative gastrography after reconstruction showed that contrast medium flowed mainly to the remnant stomach. The average percentage body weight loss was 14.0 ± 7.1% at 10 months. The average percentage decrease in serum hemoglobin was 5.4 ± 10.4% at 12 months. This novel technique for intracorporeal DTR provided a considerable advantage by the passage of dietary intake to the remnant stomach after LPG.

  14. Validation of a training method for L2 continuous-speech segmentation

    NARCIS (Netherlands)

    Cutler, A.; Shanley, J.

    2010-01-01

    Recognising continuous speech in a second language is often unexpectedly difficult, as the operation of segmenting speech is so attuned to native-language structure. We report the initial steps in development of a novel training method for secondlanguage listening, focusing on speech segmentation

  15. [Angle-stable intramedullary nailing of proximal humerus fractures with the PHN (proximal humeral nail)].

    Science.gov (United States)

    Blum, Jochen; Hansen, Matthias; Rommens, Pol Maria

    2009-09-01

    Stable fixation of two- and three-part fractures of the proximal humerus through minimally invasive operative technique and rapid bone healing as well as restoration of original anatomy. Early functional training with the goal of restoration of former mobility and daily activities. Unstabile two- and three-part fractures of the proximal humerus (AO classification: 11-A2, 11-A3, 11-B1, 11-B2, 11-B3). Subcapital nonunion of the humerus. Pathologic fractures. Pediatric fractures of the proximal humerus. Fractures of the proximal humerus types 11-C2 und 11-C3 according to the AO classification. Active local infection, e.g., after former operation. Closed reduction. Anterior acromial incision, splitting of the deltoid muscle and the rotator cuff. Opening of the medullary canal with the awl. Nail introduction. Spiral blade introduction in cannulated technique through stab incision. Distal interlocking through aiming device, angle-stable blocking of nail and blade through end cap. Postoperative fixation in Gilchrist sling until 2nd postoperative day; then physiotherapy respecting fracture type and stability, local swelling, patient's age and compliance, and concomitant injuries. 151 proximal humeral fractures were treated with a proximal humeral nail (PHN). 108 patients could be followed up 1 year postoperatively. Significant complications were perforation of the articular surface through bolts or blades (n = 8), implant-related pain (n = 10), fragment dislocation (n = 2), nonunion (n = 2), humeral head necrosis (n = 3), and superficial infection (n = 1). 1 year after the operation, the Constant-Murley Score showed a median value of 75.3 in the injured shoulder and of 89.9 in the uninjured shoulder. The DASH (Disability of the Arm, Shoulder and Hand) Score was 5.9 preoperatively and 9.3 at 1 year postoperatively. The worst results regarding the Constant-Murley Score as well as the DASH Score were found in C-type fractures.

  16. Impacted valgus fractures of the proximal humerus

    Directory of Open Access Journals (Sweden)

    Fabiano Rebouças Ribeiro

    2016-04-01

    Full Text Available Impacted valgus fractures of the proximal humerus are considered to be a special type fracture, since impaction of the humeral head on the metaphysis with maintenance of the posteromedial periosteum improves the prognosis regarding occurrences of avascular necrosis. This characteristic can also facilitate the reduction maneuver and increase the consolidation rate of these fractures, even in more complex cases. The studies included were obtained by searching the Bireme, Medline, PubMed, Cochrane Library and Google Scholar databases for those published between 1991 and 2013. The objective of this study was to identify the most common definitions, classifications and treatment methods used for these fractures in the orthopedic medical literature.

  17. Management of posttraumatic proximal interphalangeal joint contracture.

    Science.gov (United States)

    Houshian, Shirzad; Jing, Shan Shan; Chikkamuniyappa, Chandrasekar; Kazemian, Gholam Hussein; Emami-Moghaddam-Tehrani, Mohammad

    2013-08-01

    Chronic flexion contracture of the proximal interphalangeal (PIP) joint presents a common yet challenging problem to hand surgeons. Over the years, multiple treatment modalities have been described for this problem, producing limited results. Nonoperative treatment using serial casting and splints should be tried before attempting open surgical release, which should be done in selected patients. The use of external fixation for treating PIP contracture has been encouraging and can be a useful alterative. This review provides an update on the current management of PIP joint contractures and presents a flowchart of treatment to aid decision making. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  18. Proximal iliotibial band syndrome: case report

    Directory of Open Access Journals (Sweden)

    Guilherme Guadagnini Falotico

    2013-08-01

    Full Text Available OBJECTIVE: The overuse injuries in the hip joint occur commonly in sports practitioners and currently due to technical advances in diagnostic imaging, especially magnetic resonance imaging (MRI, are often misdiagnosed. Recently, a group of people were reported, all female, with pain and swelling in the pelvic region.T2-weighted MRI showed increased signal in the enthesis of the iliotibial band (ITB along the lower border of the iliac tubercle. We report a case of a 34 year old woman, non-professional runner, with pain at the iliac crest with no history of trauma and whose MRI was compatible with the proximal iliotibial band syndrome.

  19. Ontogeny of rabbit proximal tubule urea permeability

    Science.gov (United States)

    QUIGLEY, RAYMOND; LISEC, AMBER; BAUM, MICHEL

    2014-01-01

    Urea transport in the proximal tubule is passive and is dependent on the epithelial permeability. The present study examined the maturation of urea permeability (Purea) in in vitro perfused proximal convoluted tubules (PCT) and basolateral membrane vesicles (BLMV) from rabbit renal cortex. Urea transport was lower in neonatal than adult PCT at both 37 and 25°C. The PCT Purea was also lower in the neonates than the adults (37°C: 45.4 ± 10.8 vs. 88.5 ± 15.2 × 10−6 cm/s, P 0.05). The activation energy for PCT Purea was not different between the neonatal and adult groups. BLMV Purea was determined by measuring vesicle shrinkage, due to efflux of urea, using a stop-flow instrument. Neonatal BLMV Purea was not different from adult BLMV Purea at 37°C [1.14 ± 0.05 × 10−6 vs. 1.25 ± 0.05 × 10−6 cm/s; P = not significant (NS)] or 25°C (0.94 ± 0.06 vs. 1.05 ± 0.10 × 10−6 cm/s; P = NS). There was no effect of 250 μM phloretin, an inhibitor of the urea transporter, on Purea in either adult or neonatal BLMV. The activation energy for urea diffusion was also identical in the neonatal and adult BLMV. These findings in the BLMV are in contrast to the brush-border membrane vesicles (BBMV) where we have previously demonstrated that urea transport is lower in the neonate than the adult. Urea transport is lower in the neonatal proximal tubule than the adult. This is due to a lower rate of apical membrane urea transport, whereas basolateral urea transport is the same in neonates and adults. The lower Purea in neonatal proximal tubules may play a role in overall urea excretion and in developing and maintaining a high medullary urea concentration and thus in the ability to concentrate the urine during renal maturation. PMID:11353675

  20. A High Resolution Remote Sensing Image Segmentation Method by Combining Superpixels with Minimum Spanning Tree

    Directory of Open Access Journals (Sweden)

    DONG Zhipeng

    2017-06-01

    Full Text Available Image segmentation is the basic and key step of object-oriented remote sensing image analysis. Conventional image segmentation method is sensitive to image noise and hard to determine the correct segmentation scale. To solve these problems, a novel image segmentation method by combining superpixels with minimum spanning tree was proposed in this paper. First, the image is over-segmented by simple linear iterative clustering algorithm to obtain superpixels. Then, superpixels are firstly clustered by regionalization with dynamically constrained agglomerative clustering and partitioning algorithm using the initial segmentation number and the sum of squared deviations (SSD, local variance (LV, rate of LV change (ROC-LV index of graphs corresponding to the segmentation number are obtained. So the suitable image segmentation number is determined according to the SSD, LV, ROC-LV index of graphs corresponding to segmentation number. Finally, superpixels are reclustered by regionalization with dynamically constrained agglomerative clustering and partitioning algorithm based on the suitable segmentation number. The experimental results showed that the proposed method can obtain good segmentation results.

  1. Does the cerebellum initiate movement?

    Science.gov (United States)

    Thach, W T

    2014-02-01

    Opinion is divided on what the exact function of the cerebellum is. Experiments are summarized that support the following views: (1) the cerebellum is a combiner of multiple movement factors; (2) it contains anatomically fixed permanent focal representation of individual body parts (muscles and segments) and movement modes (e.g., vestibular driven vs. cognitive driven); (3) it contains flexible changing representations/memory of physical properties of the body parts including muscle strength, segment inertia, joint viscosity, and segmental interaction torques (dynamics); (4) it contains mechanisms for learning and storage of the properties in item no. 3 through trial-and-error practice; (5) it provides for linkage of body parts, motor modes, and motordynamics via the parallel fiber system; (6) it combines and integrates the many factors so as to initiate coordinated movements of the many body parts; (7) it is thus enabled to play the unique role of initiating coordinated movements; and (8) this unique causative role is evidenced by the fact that: (a) electrical stimulation of the cerebellum can initiate compound coordinated movements; (b) in naturally initiated compound movements, cerebellar discharge precedes that in downstream target structures such as motor cerebral cortex; and (c) cerebellar ablation abolishes the natural production of compound movements in the awake alert individuals.

  2. Segmentation by Large Scale Hypothesis Testing - Segmentation as Outlier Detection

    DEFF Research Database (Denmark)

    Darkner, Sune; Dahl, Anders Lindbjerg; Larsen, Rasmus

    2010-01-01

    locally. We propose a method based on large scale hypothesis testing with a consistent method for selecting an appropriate threshold for the given data. By estimating the background distribution we characterize the segment of interest as a set of outliers with a certain probability based on the estimated...... a microscope and we show how the method can handle transparent particles with significant glare point. The method generalizes to other problems. THis is illustrated by applying the method to camera calibration images and MRI of the midsagittal plane for gray and white matter separation and segmentation...

  3. Safety and feasibility of cell-based therapy of autologous bone marrow-derived mononuclear cells in plate-stabilized proximal humeral fractures in humans.

    Science.gov (United States)

    Seebach, Caroline; Henrich, Dirk; Meier, Simon; Nau, Christoph; Bonig, Halvard; Marzi, Ingo

    2016-11-15

    Local implantation of ex vivo concentrated, washed and filtrated human bone marrow-derived mononuclear cells (BMC) seeded onto β-tricalciumphosphate (TCP) significantly enhanced bone healing in a preclinical segmental defect model. Based on these results, we evaluated in a first clinical phase-I trial safety and feasibility of augmentation with preoperatively isolated autologous BMC seeded onto β-TCP in combination with angle stable plate fixation for the therapy of proximal humeral fractures as a potential alternative to autologous bone graft from the iliac crest. 10 patients were enrolled to assess whether cell therapy with 1.3 × 106 autologous BMC/ml/ml β-TCP, collected on the day preceding the definitive surgery, is safe and feasible when seeded onto β-TCP in patients with a proximal humeral fracture. 5 follow-up visits for clinical and radiological controls up to 12 weeks were performed. β-tricalciumphosphate fortification with BMC was feasible and safe; specifically, neither morbidity at the harvest site nor at the surgical wound site were observed. Neither local nor systemic inflammation was noted. All fractures healed within the observation time without secondary dislocation. Three adverse events were reported: one case each of abdominal wall shingles, tendon loosening and initial screw perforation, none of which presumed related to the IND. Cell therapy with autologous BMC for bone regeneration appeared to be safe and feasible with no drug-related adverse reactions being described to date. The impression of efficacy was given, although the study was not powered nor controlled to detect such. A clinical trial phase-II will be forthcoming in order to formally test the clinical benefit of BMC-laden β-TCP for PHF patients. Trial registration The study was registered in the European Clinical Trial Register as EudraCT No. 2012-004037-17. Date of registration 30th of August 2012. Informed consent was signed from all patients enrolled.

  4. Unsupervised sub-segmentation for pigmented skin lesions.

    Science.gov (United States)

    Liu, Zhao; Sun, Jiuai; Smith, Melvyn; Smith, Lyndon; Warr, Robert

    2012-02-01

    Early identification of malignant melanoma with the surgical removal of thin lesions is the most effective treatment for skin cancers. A computer-aided diagnostic system assists to improve the diagnostic accuracy, where segmenting lesion from normal skin is usually considered as the first step. One of the challenges in the automated segmentation of skin lesions arises from the fact that darker areas within the lesion should be considered separate from the more general suspicious lesion as a whole, because these pigmented areas can provide significant additional diagnostic information. This paper presents, for the first time, an unsupervised segmentation scheme to allow the isolation of normal skin, pigmented skin lesions, and interesting darker areas inside the lesion simultaneously. An adaptive mean-shift is first applied with a 5D spatial colour-texture feature space to generate a group of homogenous regions. Then the sub-segmentation maps are calculated by integrating maximal similarity-based region merging and the kernel k-means algorithm, where the number of segments is defined by a cluster validity measurement. The proposed method has been validated extensively on both normal digital photographs and dermoscopy images, which demonstrates competitive performance in achieving automatic segmentation. The isolated dark areas have proved helpful in the discrimination of malignant melanomas from atypical benign nevi. Compared with the results obtained from the asymmetry measure of the entire lesion, the asymmetry distribution of the isolated dark areas helped increase the accuracy of the identification of malignant melanoma from 65.38% to 73.07%, and this classification accuracy reached 80.77% on integrating both asymmetry descriptors. The proposed segmentation scheme gives the lesion boundary closed to the manual segmentation obtained by experienced dermatologists. The initial classification results indicate that the study of the distributions of darker areas

  5. Volume Segmentation and Ghost Particles

    Science.gov (United States)

    Ziskin, Isaac; Adrian, Ronald

    2011-11-01

    Volume Segmentation Tomographic PIV (VS-TPIV) is a type of tomographic PIV in which images of particles in a relatively thick volume are segmented into images on a set of much thinner volumes that may be approximated as planes, as in 2D planar PIV. The planes of images can be analysed by standard mono-PIV, and the volume of flow vectors can be recreated by assembling the planes of vectors. The interrogation process is similar to a Holographic PIV analysis, except that the planes of image data are extracted from two-dimensional camera images of the volume of particles instead of three-dimensional holographic images. Like the tomographic PIV method using the MART algorithm, Volume Segmentation requires at least two cameras and works best with three or four. Unlike the MART method, Volume Segmentation does not require reconstruction of individual particle images one pixel at a time and it does not require an iterative process, so it operates much faster. As in all tomographic reconstruction strategies, ambiguities known as ghost particles are produced in the segmentation process. The effect of these ghost particles on the PIV measurement is discussed. This research was supported by Contract 79419-001-09, Los Alamos National Laboratory.

  6. Caries status and proximal lesion behaviour during a 6-year period in young adult Danes: an epidemiological investigation.

    Science.gov (United States)

    Martignon, Stefania; Chavarría, Nathaly; Ekstrand, Kim Rud

    2010-08-01

    Studies have indicated that many initial proximal caries lesions progress and are eventually restored even if the patients have been under comprehensive preventive programmes. The objectives of the study were (1) to describe the 1996-year baseline caries status of male Danish conscripts and (2) to assess their early proximal lesions 6-year behaviour. In 1996, all 20-year-old conscripts at Central Barrack Birkerød (n = 115) went through an oral examination, including visual surface-level fillings' recording and a radiographic examination with bitewing radiographs that assessed the proximal-surface caries and restoration patterns. After 6 years, the behaviour of proximal lesions was studied in 73 of these subjects, and oral health habits were assessed through a questionnaire. Mean number of filled surfaces was 7.5, of which 23% were posterior proximal. Radiographically, the mean number of proximal lesions was 5.5. Over the 6-year period, there was progression of lesions into deeper radiolucencies or fillings in 57% of cases. The questionnaire showed a poor compliance with regular flossing/tooth-stick use (18%). Based on these results, more efficacious preventive measures seem to be needed for proximal surfaces.

  7. Comparison between two experimental protocols to promote osteoporosis in the maxilla and proximal tibia of female rats

    Directory of Open Access Journals (Sweden)

    Teófilo Juliana Mazzonetto

    2003-01-01

    Full Text Available The effects of two experimental protocols (ovariectomy associated or not with a low calcium diet used to promote osteoporosis in the rat maxilla and proximal tibia were compared 5 and 11 weeks after surgery. Female Wistar rats were ovariectomized or sham-operated. Half of the ovariectomized rats were fed a low Ca++ diet (ovx* and the remaining ovariectomized (ovx and sham animals received a standard chow. At sacrifice, the proximal metaphysis was excised from the tibia and the molars were extracted from the hemi-maxilla. Dry (60°C overnight and ash (700°C/14 h weights were measured and the ashes were used for Ca++ measurement by means of a colorimetric method. After 5 weeks, ovx caused no alteration while ovx* decreased proximal metaphysis (17% and maxilla (35% bone mass. After 11 weeks, ovx caused a 14% bone mass reduction in the proximal metaphysis but not in the maxilla, while ovx* caused a comparable bone mass reduction (30% in both bone segments. Calcium concentration was not altered in any experimental condition. The results show that estrogen deficiency is insufficient to cause maxillary osteoporosis in rats over an 11-week period and a long-term ovariectomy is needed to exert deleterious effect on proximal metaphysis bone mass. When a low Ca++ diet is associated with estrogen deficiency, however, a relatively precocious harmful effect is observed, twice as pronounced in the maxilla than in the proximal metaphysis. On a long-term basis, ovariectomy associated with a low Ca++ diet seems to be equally injurious to both proximal metaphysis and maxilla.

  8. Segmental NF: A Guide for Patients

    Science.gov (United States)

    ... the body can show signs of segmental NF. Segmental NF1 - Individuals with segmental NF1 most commonly have the skin findings associated with ... cases, can include severe complications. Many individuals with segmental NF1 never develop any complications other than café-au- ...

  9. Liver segmentation: indications, techniques and future directions.

    Science.gov (United States)

    Gotra, Akshat; Sivakumaran, Lojan; Chartrand, Gabriel; Vu, Kim-Nhien; Vandenbroucke-Menu, Franck; Kauffmann, Claude; Kadoury, Samuel; Gallix, Benoît; de Guise, Jacques A; Tang, An

    2017-08-01

    Liver volumetry has emerged as an important tool in clinical practice. Liver volume is assessed primarily via organ segmentation of computed tomography (CT) and magnetic resonance imaging (MRI) images. The goal of this paper is to provide an accessible overview of liver segmentation targeted at radiologists and other healthcare professionals. Using images from CT and MRI, this paper reviews the indications for liver segmentation, technical approaches used in segmentation software and the developing roles of liver segmentation in clinical practice. Liver segmentation for volumetric assessment is indicated prior to major hepatectomy, portal vein embolisation, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and transplant. Segmentation software can be categorised according to amount of user input involved: manual, semi-automated and fully automated. Manual segmentation is considered the "gold standard" in clinical practice and research, but is tedious and time-consuming. Increasingly automated segmentation approaches are more robust, but may suffer from certain segmentation pitfalls. Emerging applications of segmentation include surgical planning and integration with MRI-based biomarkers. Liver segmentation has multiple clinical applications and is expanding in scope. Clinicians can employ semi-automated or fully automated segmentation options to more efficiently integrate volumetry into clinical practice. • Liver volume is assessed via organ segmentation on CT and MRI examinations. • Liver segmentation is used for volume assessment prior to major hepatic procedures. • Segmentation approaches may be categorised according to the amount of user input involved. • Emerging applications include surgical planning and integration with MRI-based biomarkers.

  10. An interactive segmentation method based on superpixel

    DEFF Research Database (Denmark)

    Yang, Shu; Zhu, Yaping; Wu, Xiaoyu

    2015-01-01

    This paper proposes an interactive image-segmentation method which is based on superpixel. To achieve fast segmentation, the method is used to establish a Graphcut model using superpixels as nodes, and a new energy function is proposed. Experimental results demonstrate that the authors' method has...... excellent performance in terms of segmentation accuracy and computation efficiency compared with other segmentation algorithm based on pixels....

  11. Discourse segmentation and ambiguity in discourse structure

    NARCIS (Netherlands)

    Hoek, J.|info:eu-repo/dai/nl/375290605; Evers-Vermeul, J.|info:eu-repo/dai/nl/191644684; Sanders, T.J.M.|info:eu-repo/dai/nl/075243911

    2016-01-01

    Discourse relations hold between two or more text segments. The process of discourse annotation not only involves determining what type of relation holds between segments, but also indicating the segments themselves. Often, segmentation and annotation are treated as individual steps, and separate

  12. Skip segment Hirschsprung disease and Waardenburg syndrome

    Directory of Open Access Journals (Sweden)

    Erica R. Gross

    2015-04-01

    Full Text Available Skip segment Hirschsprung disease describes a segment of ganglionated bowel between two segments of aganglionated bowel. It is a rare phenomenon that is difficult to diagnose. We describe a recent case of skip segment Hirschsprung disease in a neonate with a family history of Waardenburg syndrome and the genetic profile that was identified.

  13. 47 CFR 95.853 - Frequency segments.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency segments. 95.853 Section 95.853... SERVICES 218-219 MHz Service Technical Standards § 95.853 Frequency segments. There are two frequency segments available for assignment to the 218-219 MHz Service in each service area. Frequency segment A is...

  14. Analysis of segmental phosphate absorption in intact rats. A compartmental analysis approach.

    OpenAIRE

    Kayne, L H; D'Argenio, D Z; Meyer, J H; Hu, M S; Jamgotchian, N; Lee, D B

    1993-01-01

    Available information supports the dominance of the proximal intestine in inorganic phosphate (Pi) absorption. However, there is no strategy for analyzing segmental Pi absorption from a spontaneously propelled meal in an intact animal. We propose a solution using compartmental analysis. After intragastric administration of a 32P-labeled Pi liquid meal containing a nonabsorbable marker, [14C]polyethylene glycol (PEG), rats were killed at 2, 10, 20, 30, 60, 120, and 240 min. The gastrointestina...

  15. 3D variational brain tumor segmentation using Dirichlet priors on a clustered feature set.

    Science.gov (United States)

    Popuri, Karteek; Cobzas, Dana; Murtha, Albert; Jägersand, Martin

    2012-07-01

    Brain tumor segmentation is a required step before any radiation treatment or surgery. When performed manually, segmentation is time consuming and prone to human errors. Therefore, there have been significant efforts to automate the process. But, automatic tumor segmentation from MRI data is a particularly challenging task. Tumors have a large diversity in shape and appearance with intensities overlapping the normal brain tissues. In addition, an expanding tumor can also deflect and deform nearby tissue. In our work, we propose an automatic brain tumor segmentation method that addresses these last two difficult problems. We use the available MRI modalities (T1, T1c, T2) and their texture characteristics to construct a multidimensional feature set. Then, we extract clusters which provide a compact representation of the essential information in these features. The main idea in this work is to incorporate these clustered features into the 3D variational segmentation framework. In contrast to previous variational approaches, we propose a segmentation method that evolves the contour in a supervised fashion. The segmentation boundary is driven by the learned region statistics in the cluster space. We incorporate prior knowledge about the normal brain tissue appearance during the estimation of these region statistics. In particular, we use a Dirichlet prior that discourages the clusters from the normal brain region to be in the tumor region. This leads to a better disambiguation of the tumor from brain tissue. We evaluated the performance of our automatic segmentation method on 15 real MRI scans of brain tumor patients, with tumors that are inhomogeneous in appearance, small in size and in proximity to the major structures in the brain. Validation with the expert segmentation labels yielded encouraging results: Jaccard (58%), Precision (81%), Recall (67%), Hausdorff distance (24 mm). Using priors on the brain/tumor appearance, our proposed automatic 3D variational

  16. Proximal-to-distal sequencing in vertical jumping with and without arm swing.

    Science.gov (United States)

    Chiu, Loren Z F; Bryanton, Megan A; Moolyk, Amy N

    2014-05-01

    Vertical jumping performance is dependent on muscle strength and motor skill. An understanding of motor skill strategies and their influence on jumping mechanics provides insight into how to improve performance. This study aimed to determine whether kinematic sequencing strategy influenced jump height, the effect of sequencing on jumping mechanics, and whether arm swing influences sequencing strategy. Women volleyball players (n = 16) performed vertical jumps with and without arm swing on force platforms while recorded with a 6-camera motion capture system. Sequencing strategy was determined as the relative time delay between pelvis and knee extension. A long time delay indicated a proximal-to-distal strategy, whereas no time delay represented a simultaneous strategy. Longer relative time delay was correlated with higher jump height in jumps with (r = 0.82, p jump height were associated with greater hip extensor and ankle plantar flexor net joint moments (NJM), and greater ratio of concentric to eccentric knee extensor NJM (p ≤ 0.05). Longer relative time delay and higher jump height were correlated with greater thigh and leg angular accelerations (p ≤ 0.05). These kinetic and kinematic variables, along with relative time delay and jump height were greater in jumps with arm swing than without (p ≤ 0.05), indicating arm swing promotes use of a proximal-to-distal strategy. Use of a proximal-to-distal strategy is associated with greater NJM and segment accelerations, which may contribute to better vertical jump performance.

  17. Proximal tubular epithelial cells are generated by division of differentiated cells in the healthy kidney.

    Science.gov (United States)

    Vogetseder, Alexander; Palan, Thomas; Bacic, Desa; Kaissling, Brigitte; Le Hir, Michel

    2007-02-01

    We searched for evidence for a contribution of stem cells in growth of the proximal S3 segments of healthy rats. According to the stem cell model, stem cells are undifferentiated and slow cycling; the bulk of cycling cells are transit amplifying, rapidly cycling cells. We show the following. 1) By continuous application of a thymidine analog (ThA) for 7 days, S3 proximal epithelial cells in healthy kidneys display a high-cycling rate. 2) Slow-cycling cells, identified by lack of ThA uptake during 14 days of continuous ThA application up to death and by expression of the cell cycle protein Ki67 at death, have the same degree of differentiation as quiescent cells. 3) To detect rapidly cycling cells, rats were killed at various time points after injection of a ThA. Double immunofluorescence for ThA and a cell cycle marker was performed, with colocalization indicating successive divisions. During one week after division, daughter cells display a very low proliferation rate, indicating the absence of rapidly cycling cells. 4) Labeling with cyclin D1 showed that this low proliferation rate is due to cycle arrest. 5) More than 50% of the S3 cells entered the cell cycle 36 h after a potent proliferative stimulus (lead acetate injection). We conclude that generation of new cells in the proximal tubule relies on division of differentiated, normally slow-cycling cells. These may rapidly enter the cycle under an adequate stimulus.

  18. Validity of Digital Imaging of Fiber-Optic Transillumination in Caries Detection on Proximal Tooth Surfaces.

    Science.gov (United States)

    Laitala, Marja-Liisa; Piipari, Liina; Sämpi, Noora; Korhonen, Maria; Pesonen, Paula; Joensuu, Tiina; Anttonen, Vuokko

    2017-01-01

    The aim of our study was to evaluate the validity of the digital imaging fiber-optic transillumination (DIFOTI) method in comparison with clinical visual examination (CV) and bitewing (BW) radiography on detecting caries lesions on proximal surfaces of teeth. Proximal tooth surfaces of premolars and molars ( n = 2,103) of 91 voluntary university students aged from 18 to 30 years were examined with CV, BW radiography, and the DIFOTI method. DIFOTI detected more initial and manifested caries lesions compared with CV and BW. Of the analyzed tooth surfaces, 69.8% were classified as sound by DIFOTI, 80.3% by BW, and 91.6% by CV. Initial caries lesions were found in 21.2% of the surfaces by DIFOTI, in 14.1% by BW, and in 6.2% by CV, whereas the proportions for manifested dental caries lesions were 9.0%, 5.6%, and 2.2%, respectively. The interexaminer agreement regarding the DIFOTI findings between an experienced clinician and a fifth-year dental student was high: κ = 0.67 for initial and κ = 0.91 for manifested caries lesions. The noninvasive DIFOTI method seems to offer a potential tool for everyday clinical practice. In clinical use, DIFOTI finds well even initial caries lesions on proximal surfaces, thus providing an instrument for detecting lesions potential for arresting as well as for monitoring the outcome after preventive measures.

  19. Validity of Digital Imaging of Fiber-Optic Transillumination in Caries Detection on Proximal Tooth Surfaces

    Directory of Open Access Journals (Sweden)

    Marja-Liisa Laitala

    2017-01-01

    Full Text Available Objective. The aim of our study was to evaluate the validity of the digital imaging fiber-optic transillumination (DIFOTI method in comparison with clinical visual examination (CV and bitewing (BW radiography on detecting caries lesions on proximal surfaces of teeth. Materials and Methods. Proximal tooth surfaces of premolars and molars (n=2,103 of 91 voluntary university students aged from 18 to 30 years were examined with CV, BW radiography, and the DIFOTI method. Results. DIFOTI detected more initial and manifested caries lesions compared with CV and BW. Of the analyzed tooth surfaces, 69.8% were classified as sound by DIFOTI, 80.3% by BW, and 91.6% by CV. Initial caries lesions were found in 21.2% of the surfaces by DIFOTI, in 14.1% by BW, and in 6.2% by CV, whereas the proportions for manifested dental caries lesions were 9.0%, 5.6%, and 2.2%, respectively. The interexaminer agreement regarding the DIFOTI findings between an experienced clinician and a fifth-year dental student was high: κ=0.67 for initial and κ=0.91 for manifested caries lesions. Conclusions. The noninvasive DIFOTI method seems to offer a potential tool for everyday clinical practice. In clinical use, DIFOTI finds well even initial caries lesions on proximal surfaces, thus providing an instrument for detecting lesions potential for arresting as well as for monitoring the outcome after preventive measures.

  20. Is the T9, T11, or L1 the more reliable proximal level after adult lumbar or lumbosacral instrumented fusion to L5 or S1?

    Science.gov (United States)

    Kim, Yongjung J; Bridwell, Keith H; Lenke, Lawrence G; Rhim, Seungchul; Kim, Young-Woo

    2007-11-15

    A retrospective comparison study. To compare the postoperative proximal junctional change and revision prevalence as influenced by 3 different proximal levels after adult lumbar deformity instrumented fusion from the distal thoracic/upper lumbar spine (T9-L2) to L5 or S1. Few comparative studies on postoperative sagittal plane change and revision prevalence as influenced by 3 different proximal levels after adult lumbar deformity instrumented fusion from the distal thoracic/upper lumbar spine (T9-L2) to L5 or S1 have been published. Many surgeons have hypothesized that stopping proximally in the upper lumbar spine (L1 or L2) or the thoracolumbar junction (T11 or T12) would lead to a high percentage of rapid proximal degeneration, kyphosis, and decompensation because of the concentration of stress on these relatively mobile segments. Therein, many surgeons have felt it is unsafe to stop at these regions of the spine and it is better to always stop proximally at T9 or T10. A clinical and radiographic assessment in addition to revision prevalence of 125 adult lumbar deformity patients (average age 57.1 year) who underwent long (average 7.1 vertebrae) segmental posterior spinal instrumented fusion from the distal thoracic/upper lumbar spine (T9-L2) to L5 or S1 with a minimum 2-year follow-up (2-19.8 year follow-up) were compared as influenced by T9-T10 (group 1, n = 37), T11-T12 (group 2, n = 49), and L1-L2 (group 3, n = 39) proximal fusion levels. The revision prevalence and sagittal Cobb angle change at the proximal junction after surgery were compared. Three groups demonstrated nonsignificant differences in the prevalence of proximal junctional kyphosis (group 1 51% vs. group 2 55% vs. group 3 36%, P = 0.20) and revision (group 1 24% vs. group 2 24% vs. group 3 26%, P = 0.99) at the ultimate follow-up. Subsequent proximal junctional angle and sagittal vertical axis changes between the ultimate follow-up and preoperative (P = 0.10 and 0.46 respectively) were not

  1. Congenital anomalies and proximity to landfill sites.

    LENUS (Irish Health Repository)

    Boyle, E

    2004-01-01

    The occurrence of congenital anomalies in proximity to municipal landfill sites in the Eastern Region (counties Dublin, Kildare, Wicklow) was examined by small area (district electoral division), distance and clustering tendancies in relation to 83 landfills, five of which were major sites. The study included 2136 cases of congenital anomaly, 37,487 births and 1423 controls between 1986 and 1990. For the more populous areas of the region 50% of the population lived within 2-3 km of a landfill and within 4-5 km for more rural areas. In the area-level analysis, the standardised prevalence ratios, empirical and full Bayesian modelling, and Kulldorff\\'s spatial scan statistic found no association between the residential area of cases and location of landfills. In the case control analysis, the mean distance of cases and controls from the nearest landfill was similar. The odds ratios of cases compared to controls for increasing distances from all landfills and major landfills showed no significant difference from the baseline value of 1. The kernel and K methods showed no tendency of cases to cluster in relationship to landfills. In conclusion, congenital anomalies were not found to occur more commonly in proximity to municipal landfills.

  2. Scattering Effects in Proximity Effect Tunneling Spectroscopy.

    Science.gov (United States)

    Gai, Wei

    PETS (Proximity Effect Tunneling Spectroscopy) technique has been applied to Niobium/Yttrium and Niobium/Lutetium bilayers. We have determined electron - phonon interaction parameter lambda_{rm e -ph} is 0.55 for Yttrium and 0.67 for Lutetium. Spin fluctuations parameter lambda_{ rm S} is 0.20 for Yttrium and 0.33 for Lutetium. We found that the large spin fluctuations in Yttrium and Lutetium has responsibility to the absence of superconductivity in them. Our results have given a reasonable explanation of high superconducting transition temperature in them under high pressure. The large reflection coefficient and strong diffuse scattering at Nb/Y and Nb/Lu interface has been discovered and it should have strong influence on the transport properties of metallic superlattices. From the modeling study of elastic scattering in proximity effect tunnel junctions, we have explained why some conventional made high {rm T_{C}} superconducting tunnel junctions give ideal like characteristics in the gap region but variable strength phonon structures in the phonon region.

  3. Proteomics of Primary Cilia by Proximity Labeling.

    Science.gov (United States)

    Mick, David U; Rodrigues, Rachel B; Leib, Ryan D; Adams, Christopher M; Chien, Allis S; Gygi, Steven P; Nachury, Maxence V

    2015-11-23

    While cilia are recognized as important signaling organelles, the extent of ciliary functions remains unknown because of difficulties in cataloguing proteins from mammalian primary cilia. We present a method that readily captures rapid snapshots of the ciliary proteome by selectively biotinylating ciliary proteins using a cilia-targeted proximity labeling enzyme (cilia-APEX). Besides identifying known ciliary proteins, cilia-APEX uncovered several ciliary signaling molecules. The kinases PKA, AMPK, and LKB1 were validated as bona fide ciliary proteins and PKA was found to regulate Hedgehog signaling in primary cilia. Furthermore, proteomics profiling of Ift27/Bbs19 mutant cilia correctly detected BBSome accumulation inside Ift27(-/-) cilia and revealed that β-arrestin 2 and the viral receptor CAR are candidate cargoes of the BBSome. This work demonstrates that proximity labeling can be applied to proteomics of non-membrane-enclosed organelles and suggests that proteomics profiling of cilia will enable a rapid and powerful characterization of ciliopathies. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Empathy: Its ultimate and proximate bases.

    Science.gov (United States)

    Preston, Stephanie D; de Waal, Frans B M

    2002-02-01

    There is disagreement in the literature about the exact nature of the phenomenon of empathy. There are emotional, cognitive, and conditioning views, applying in varying degrees across species. An adequate description of the ultimate and proximate mechanism can integrate these views. Proximately, the perception of an object's state activates the subject's corresponding representations, which in turn activate somatic and autonomic responses. This mechanism supports basic behaviors (e.g., alarm, social facilitation, vicariousness of emotions, mother-infant responsiveness, and the modeling of competitors and predators) that are crucial for the reproductive success of animals living in groups. The Perception-Action Model (PAM), together with an understanding of how representations change with experience, can explain the major empirical effects in the literature (similarity, familiarity, past experience, explicit teaching, and salience). It can also predict a variety of empathy disorders. The interaction between the PAM and prefrontal functioning can also explain different levels of empathy across species and age groups. This view can advance our evolutionary understanding of empathy beyond inclusive fitness and reciprocal altruism and can explain different levels of empathy across individuals, species, stages of development, and situations.

  5. Proximal femoral osteotomy in cerebral palsy.

    Science.gov (United States)

    Tylkowski, C M; Rosenthal, R K; Simon, S R

    1980-09-01

    The purpose of this study was to examine the results of the proximal femoral osteotomy for the management of hip deformity in 32 children, aged 4 to 15 years. Twenty-two bilateral and ten unilateral procedures were performed. The indications for surgery were subluxation in 16, dislocation in two, and intoeing and femoral anteversion in 14. The average follow-up was two years and 11 months. CE angle of Wiberg, acetabular index and neck shaft angle were evaluated. The average time to regain preoperative ambulatory status was six months with intensive physical therapy. In osteotomies performed for subluxation, dislocation did not occur; roentgenographic indices showed variability in the degree of subluxation. Osteotomy performed in children older than 8 years of age produced no evidence of acetabular remodeling. THere was no recurrence with osteotomies for dislocation. In those patients with internal rotation gait, improvement resulted. Complications were few and minor. Hip dislocation in children with progressive subluxation, in spite of previous soft-tissue releases, is preventable by proximal femoral osteotomy. The inability of the roentgenographic indices to quantitate the increased stability indicates the procedure's major effect is to realign muscle forces about the hip. Treatment of the intoeing gait produced improvement of rotational deformity.

  6. Obesity and supermarket access: proximity or price?

    Science.gov (United States)

    Drewnowski, Adam; Aggarwal, Anju; Hurvitz, Philip M; Monsivais, Pablo; Moudon, Anne V

    2012-08-01

    We examined whether physical proximity to supermarkets or supermarket price was more strongly associated with obesity risk. The Seattle Obesity Study (SOS) collected and geocoded data on home addresses and food shopping destinations for a representative sample of adult residents of King County, Washington. Supermarkets were stratified into 3 price levels based on average cost of the market basket. Sociodemographic and health data were obtained from a telephone survey. Modified Poisson regression was used to test the associations between obesity and supermarket variables. Only 1 in 7 respondents reported shopping at the nearest supermarket. The risk of obesity was not associated with street network distances between home and the nearest supermarket or the supermarket that SOS participants reported as their primary food source. The type of supermarket, by price, was found to be inversely and significantly associated with obesity rates, even after adjusting for individual-level sociodemographic and lifestyle variables, and proximity measures (adjusted relative risk=0.34; 95% confidence interval=0.19, 0.63) Improving physical access to supermarkets may be one strategy to deal with the obesity epidemic; improving economic access to healthy foods is another.

  7. Demonstration of automated proximity and docking technology

    Science.gov (United States)

    Anderson, Robert L.; Tsugawa, Roy K.; Bryan, Thomas C.

    1991-01-01

    Automated spacecraft docking operations are being performed using a full scale motion based simulator and an optical sensor. This presentation will discuss the work in progress at TRW and MSFC facilities to study the problem of automated proximity and docking operations. The docking sensor used in the MSFC Optical Sensor and simulation runs are performed using the MSFC Flat Floor Facility. The control algorithms and six degrees of freedom (6DOF) simulation software were developed at TRW and integrated into the MSFC facility. Key issues being studied are the quantification of docking sensor requirements and operational constraints necessary to perform automated docking maneuvers, control algorithms capable of performing automated docking in the presence of sensitive and noisy sensor data, and sensor technologies for automated proximity and docking operations. As part of this study the MSFC sensor characteristics were analyzed and modeled so that off line simulation runs can be performed for control algorithm testing. Our goal is to develop and demonstrate full 6DOF docking capabilities with actual sensors on the MSFC motion based simulator. We present findings from actual docking simulation runs which show sensor and control loop performance as well as problem areas which require close attention. The evolution of various control algorithms using both phase plane and Clohessy-Wiltshire techniques are discussed. In addition, 6DOF target acquisition and control strategies are described.

  8. Neuron Segmentation in Electron Microscopy Images Using Partial Differential Equations.

    Science.gov (United States)

    Jones, Cory; Sayedhosseini, Mojtaba; Ellisman, Mark; Tasdizen, Tolga

    2013-01-01

    In connectomics, neuroscientists seek to identify the synaptic connections between neurons. Segmentation of cell membranes using supervised learning algorithms on electron microscopy images of brain tissue is often done to assist in this effort. Here we present a partial differential equation with a novel growth term to improve the results of a supervised learning algorithm. We also introduce a new method for representing the resulting image that allows for a more dynamic thresholding to further improve the result. Using these two processes we are able to close small to medium sized gaps in the cell membrane detection and improve the Rand error by as much as 9% over the initial supervised segmentation.

  9. Prediction of the pre-morbid 3D anatomy of the proximal humerus based on statistical shape modelling.

    Science.gov (United States)

    Poltaretskyi, S; Chaoui, J; Mayya, M; Hamitouche, C; Bercik, M J; Boileau, P; Walch, G

    2017-07-01

    Restoring the pre-morbid anatomy of the proximal humerus is a goal of anatomical shoulder arthroplasty, but reliance is placed on the surgeon's experience and on anatomical estimations. The purpose of this study was to present a novel method, 'Statistical Shape Modelling', which accurately predicts the pre-morbid proximal humeral anatomy and calculates the 3D geometric parameters needed to restore normal anatomy in patients with severe degenerative osteoarthritis or a fracture of the proximal humerus. From a database of 57 humeral CT scans 3D humeral reconstructions were manually created. The reconstructions were used to construct a statistical shape model (SSM), which was then tested on a second set of 52 scans. For each humerus in the second set, 3D reconstructions of four diaphyseal segments of varying lengths were created. These reconstructions were chosen to mimic severe osteoarthritis, a fracture of the surgical neck of the humerus and a proximal humeral fracture with diaphyseal extension. The SSM was then applied to the diaphyseal segments to see how well it predicted proximal morphology, using the actual proximal humeral morphology for comparison. With the metaphysis included, mimicking osteoarthritis, the errors of prediction for retroversion, inclination, height, radius of curvature and posterior and medial offset of the head of the humerus were 2.9° (± 2.3°), 4.0° (± 3.3°), 1.0 mm (± 0.8 mm), 0.8 mm (± 0.6 mm), 0.7 mm (± 0.5 mm) and 1.0 mm (± 0.7 mm), respectively. With the metaphysis excluded, mimicking a fracture of the surgical neck, the errors of prediction for retroversion, inclination, height, radius of curvature and posterior and medial offset of the head of the humerus were 3.8° (± 2.9°), 3.9° (± 3.4°), 2.4 mm (± 1.9 mm), 1.3 mm (± 0.9 mm), 0.8 mm (± 0.5 mm) and 0.9 mm (± 0.6 mm), respectively. This study reports a novel, computerised method that accurately predicts the pre-morbid proximal humeral anatomy even in challenging

  10. Learning to Segment Moving Objects in Videos

    OpenAIRE

    Fragkiadaki, Katerina; Arbelaez, Pablo; Felsen, Panna; Malik, Jitendra

    2014-01-01

    We segment moving objects in videos by ranking spatio-temporal segment proposals according to "moving objectness": how likely they are to contain a moving object. In each video frame, we compute segment proposals using multiple figure-ground segmentations on per frame motion boundaries. We rank them with a Moving Objectness Detector trained on image and motion fields to detect moving objects and discard over/under segmentations or background parts of the scene. We extend the top ranked segmen...

  11. Optimally segmented permanent magnet structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bjørk, Rasmus; Smith, Anders

    2016-01-01

    We present an optimization approach which can be employed to calculate the globally optimal segmentation of a two-dimensional magnetic system into uniformly magnetized pieces. For each segment the algorithm calculates the optimal shape and the optimal direction of the remanent flux density vector......, with respect to a linear objective functional. We illustrate the approach with results for magnet design problems from different areas, such as a permanent magnet electric motor, a beam focusing quadrupole magnet for particle accelerators and a rotary device for magnetic refrigeration....

  12. Segmenting Brain Tumors with Symmetry

    OpenAIRE

    Zhang, Hejia; Zhu, Xia; Willke, Theodore L.

    2017-01-01

    We explore encoding brain symmetry into a neural network for a brain tumor segmentation task. A healthy human brain is symmetric at a high level of abstraction, and the high-level asymmetric parts are more likely to be tumor regions. Paying more attention to asymmetries has the potential to boost the performance in brain tumor segmentation. We propose a method to encode brain symmetry into existing neural networks and apply the method to a state-of-the-art neural network for medical imaging s...

  13. Four segment piezo based micropump

    Science.gov (United States)

    Haldkar, Rakesh Kumar; Sheorey, Tanuja; Gupta, Vijay Kumar; Ansari, M. Zahid

    2017-06-01

    In recent years, micropumps have been investigated by various researchers as drug delivery and disease diagnostic devices. Many of these micropumps have been designed, considering available micro fabrication technologies rather than appropriate pump performance analysis. Piezoelectric based micro pumps are more popular as compared to other smart materials being explored. In this paper, four segment piezoelectric bimorph actuator (FSPB) are compared with circular disc piezoelectric bimorph actuator (CDPB) based pump. The static and transient behaviors under various electric fields have been analyzed by using ANSYS 12.1(R) finite element software. Simulation results show that dividing the actuator in segment can amplify the deflection and improve the performance of the pump.

  14. Robust iris segmentation through parameterization of the Chan-Vese algorithm

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, G

    2015-06-01

    Full Text Available -Vese algorithm with pre-defined initial contour and curve evolution parameters for accurate segmentation. Preprocessing techniques to enhance and detect iris features for extraction. Labeling features of strongest pixel connectivity and using Harris algorithm...

  15. Anterior Segment Ischemia after Strabismus Surger

    Directory of Open Access Journals (Sweden)

    Emine Seyhan Göçmen

    2017-01-01

    Full Text Available A 46-year-old male patient was referred to our clinic with complaints of diplopia and esotropia in his right eye that developed after a car accident. The patient had right esotropia in primary position and abduction of the right eye was totally limited. Primary deviation was over 40 prism diopters at near and distance. The patient was diagnosed with sixth nerve palsy and 18 months after trauma, he underwent right medial rectus muscle recession. Ten months after the first operation, full-thickness tendon transposition of the superior and inferior rectus muscles (with Foster suture was performed. On the first postoperative day, slit-lamp examination revealed corneal edema, 3+ cells in the anterior chamber and an irregular pupil. According to these findings, the diagnosis was anterior segment ischemia. Treatment with 0.1/5 mL topical dexamethasone drops (16 times/day, cyclopentolate hydrochloride drops (3 times/day and 20 mg oral fluocortolone (3 times/day was initiated. After 1 week of treatment, corneal edema regressed and the anterior chamber was clean. Topical and systemic steroid treatment was gradually discontinued. At postoperative 1 month, the patient was orthophoric and there were no pathologic symptoms besides the irregular pupil. Anterior segment ischemia is one of the most serious complications of strabismus surgery. Despite the fact that in most cases the only remaining sequel is an irregular pupil, serious circulation deficits could lead to phthisis bulbi. Clinical properties of anterior segment ischemia should be well recognized and in especially risky cases, preventative measures should be taken.

  16. Pathological fractures of the proximal humerus treated with a proximal humeral locking plate and bone cement.

    Science.gov (United States)

    Siegel, H J; Lopez-Ben, R; Mann, J P; Ponce, B A

    2010-05-01

    Bone loss secondary to primary or metastatic lesions of the proximal humerus remains a challenging surgical problem. Options include preservation of the joint with stabilisation using internal fixation or resection of the tumour with prosthetic replacement. Resection of the proximal humerus often includes the greater tuberosity and adjacent diaphysis, which may result in poor function secondary to loss of the rotator cuff and/or deltoid function. Preservation of the joint with internal fixation may reduce the time in hospital and peri-operative morbidity compared with joint replacement, and result in a better functional outcome. We included 32 patients with pathological fractures of the proximal humerus in this study. Functional and radiological assessments were performed. At a mean follow-up of 17.6 months (8 to 61) there was no radiological evidence of failure of fixation. The mean revised musculoskeletal Tumour Society functional score was 94.6% (86% to 99%). There was recurrent tumour requiring further surgery in four patients (12.5%). Of the 22 patients who were employed prior to presentation all returned to work without restrictions. The use of a locking plate combined with augmentation with cement extends the indications for salvage of the proximal humerus with good function in patients with pathological and impending pathological fractures.

  17. A Hybrid Segmentation Framework for Computer-Assisted Dental Procedures

    Science.gov (United States)

    Hosntalab, Mohammad; Aghaeizadeh Zoroofi, Reza; Abbaspour Tehrani-Fard, Ali; Shirani, Gholamreza; Reza Asharif, Mohammad

    Teeth segmentation in computed tomography (CT) images is a major and challenging task for various computer assisted procedures. In this paper, we introduced a hybrid method for quantification of teeth in CT volumetric dataset inspired by our previous experiences and anatomical knowledge of teeth and jaws. In this regard, we propose a novel segmentation technique using an adaptive thresholding, morphological operations, panoramic re-sampling and variational level set algorithm. The proposed method consists of several steps as follows: first, we determine the operation region in CT slices. Second, the bony tissues are separated from other tissues by utilizing an adaptive thresholding technique based on the 3D pulses coupled neural networks (PCNN). Third, teeth tissue is classified from other bony tissues by employing panorex lines and anatomical knowledge of teeth in the jaws. In this case, the panorex lines are estimated using Otsu thresholding and mathematical morphology operators. Then, the proposed method is followed by calculating the orthogonal lines corresponding to panorex lines and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the integral projections of the panoramic dataset. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a variational level set to refine initial teeth boundaries to final contour. In the last step a surface rendering algorithm known as marching cubes (MC) is applied to volumetric visualization. The proposed algorithm was evaluated in the presence of 30 cases. Segmented images were compared with manually outlined contours. We compared the performance of segmentation method using ROC analysis of the thresholding, watershed and our previous works. The proposed method performed best. Also, our algorithm has the advantage of high speed compared to our previous works.

  18. A patient-specific segmentation framework for longitudinal MR images of traumatic brain injury

    Science.gov (United States)

    Wang, Bo; Prastawa, Marcel; Irimia, Andrei; Chambers, Micah C.; Vespa, Paul M.; Van Horn, John D.; Gerig, Guido

    2012-02-01

    Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Robust, reproducible segmentations of MR images with TBI are crucial for quantitative analysis of recovery and treatment efficacy. However, this is a significant challenge due to severe anatomy changes caused by edema (swelling), bleeding, tissue deformation, skull fracture, and other effects related to head injury. In this paper, we introduce a multi-modal image segmentation framework for longitudinal TBI images. The framework is initialized through manual input of primary lesion sites at each time point, which are then refined by a joint approach composed of Bayesian segmentation and construction of a personalized atlas. The personalized atlas construction estimates the average of the posteriors of the Bayesian segmentation at each time point and warps the average back to each time point to provide the updated priors for Bayesian segmentation. The difference between our approach and segmenting longitudinal images independently is that we use the information from all time points to improve the segmentations. Given a manual initialization, our framework automatically segments healthy structures (white matter, grey matter, cerebrospinal fluid) as well as different lesions such as hemorrhagic lesions and edema. Our framework can handle different sets of modalities at each time point, which provides flexibility in analyzing clinical scans. We show results on three subjects with acute baseline scans and chronic follow-up scans. The results demonstrate that joint analysis of all the points yields improved segmentation compared to independent analysis of the two time points.

  19. Digital camera resolution and proximal caries detection.

    Science.gov (United States)

    Prapayasatok, S; Janhom, A; Verochana, K; Pramojanee, S

    2006-07-01

    To evaluate the diagnostic accuracy of proximal caries detection from digitized film images captured by a digital camera at different resolution settings. Twenty-five periapical radiographs of 50 premolar and 25 molar teeth were photographed using a digital camera, Sony Cyber-shot, DSC-S75 at three different resolution settings: 640 x 480, 1280 x 960 and 1600 x 1200. Seventy-five digital images were transferred to a computer, saved and opened using ACDSee software. In addition, a PowerPoint slide was made from each digital image. Five observers scored three groups of images (the films, the displayed 1:1 digital images on the ACDSee software, and the PowerPoint slides) for the existence of proximal caries using a 5-point confidence scale, and the depth of caries on a 4-point scale. Ground sections of the teeth were used as the gold standard. Az values under the receiver operating characteristic (ROC) curve of each group of images and at different resolutions were compared using the Friedman and Wilcoxon signed rank tests. Mean different values between the lesions' depth interpreted by the observers and that of the gold standard were analysed. Films showed the highest Az values. Only the 1280 x 960 images on the ACDSee software showed no significant difference of the Az value from the films (P=0.28). The digital images from three resolution settings on the PowerPoint slides showed no significant differences, either among each other or between them and the films. For caries depth, the 1280 x 960 images showed lower values of mean difference in enamel lesions compared with the other two resolution groups. This study showed that in order to digitize conventional films, it was not necessary to use the highest camera resolution setting to achieve high diagnostic accuracy for proximal caries detection. The 1280 x 960 resolution setting of the digital camera demonstrated comparable diagnostic accuracy with film and was adequate for digitizing radiographs for caries

  20. A scale-space curvature matching algorithm for the reconstruction of complex proximal humeral fractures.

    Science.gov (United States)

    Vlachopoulos, Lazaros; Székely, Gábor; Gerber, Christian; Fürnstahl, Philipp

    2018-01-01

    The optimal surgical treatment of complex fractures of the proximal humerus is controversial. It is proven that best results are obtained if an anatomical reduction of the fragments is achieved and, therefore, computer-assisted methods have been proposed for the reconstruction of the fractures. However, complex fractures of the proximal humerus are commonly accompanied with a relevant displacement of the fragments and, therefore, algorithms relying on the initial position of the fragments might fail. The state-of-the-art algorithm for complex fractures of the proximal humerus requires the acquisition of a CT scan of the (healthy) contralateral anatomy as a reconstruction template to address the displacement of the fragments. Pose-invariant fracture line based reconstruction algorithms have been applied successful for reassembling broken vessels in archaeology. Nevertheless, the extraction of the fracture lines and the necessary computation of their curvature are susceptible to noise and make the application of previous approaches difficult or even impossible for bone fractures close to the joints, where the cortical layer is thin. We present a novel scale-space representation of the curvature, permitting to calculate the correct alignment between bone fragments solely based on corresponding regions of the fracture lines. The fractures of the proximal humerus are automatically reconstructed based on iterative pairwise reduction of the fragments. The validation of the presented method was performed on twelve clinical cases, surgically treated after complex proximal humeral fracture, and by cadaver experiments. The accuracy of our approach was compared to the state-of-the-art algorithm for complex fractures of the proximal humerus. All reconstructions of the clinical cases resulted in an accurate approximation of the pre-traumatic anatomy. The accuracy of the reconstructed cadaver cases outperformed the current state-of-the-art algorithm. Copyright © 2017 Elsevier B

  1. The non-operative resin treatment of proximal caries lesions.

    Science.gov (United States)

    Ekstrand, Kim; Martignon, Stefania; Bakhshandeh, Azam; Ricketts, David N J

    2012-11-01

    Epidemiological data show that the prevalence of caries on proximal surfaces in need of operative treatment is very high around the world, both in the primary and the permanent dentition. This article presents two new treatment methods: proximal sealing and proximal infiltration. The indications are progressing proximal caries lesions, radiographically with a depth around the enamel-dentine junction. A small number of studies regarding the effect of sealing and infiltration on proximal caries versus the use of fluoride varnish, placebo treatment and flossing instructions have been carried out. About half of the studies disclose a not significant difference between test and control treatment. In the other half, the therapeutic effect is significant and corresponds to about 30% reduction in lesion progression. However, longitudinal studies of longer duration are lacking. Proximal sealing and proximal infiltration may have a place in the treatment of non-cavitated proximal lesions. Proximal caries is a problem in both primary and permanent dentitions. Proximal sealants or lesion infiltration are possible treatments.

  2. Proximity to safety-net clinics and HPV vaccine uptake among low-income, ethnic minority girls.

    Science.gov (United States)

    Tsui, Jennifer; Singhal, Rita; Rodriguez, Hector P; Gee, Gilbert C; Glenn, Beth A; Bastani, Roshan

    2013-04-12

    Human Papillomavirus (HPV) vaccine uptake remains low. Although publicly funded programs provide free or low cost vaccines to low-income children, barriers aside from cost may prevent disadvantaged girls from getting vaccinated. Prior studies have shown distance to health care as a potential barrier to utilizing pediatric preventive services. This study examines whether HPV vaccines are geographically accessible for low-income girls in Los Angeles County and whether proximity to safety-net clinics is associated with vaccine initiation. Interviews were conducted in multiple languages with largely immigrant, low-income mothers of girls ages 9 to 18 via a county health hotline to assess uptake and correlates of uptake. Addresses of respondents and safety-net clinics that provide the HPV vaccine for free or low cost were geo-coded and linked to create measures of geographic proximity. Logistic regression models were estimated for each proximity measure on HPV vaccine initiation while controlling for other factors. On average, 83% of the 468 girls had at least one clinic within 3-miles of their residence. The average travel time on public transportation to the nearest clinic among all girls was 21min. Average proximity to clinics differed significantly by race/ethnicity. Latinas had both the shortest travel distances (2.2 miles) and public transportation times (16min) compared to other racial/ethnic groups. The overall HPV vaccine initiation rate was 25%. Increased proximity to the nearest clinic was not significantly associated with initiation. By contrast, daughter's age and insurance status were significantly associated with increased uptake. This study is among the first to examine geographic access to HPV vaccines for underserved girls. Although the majority of girls live in close proximity to safety-net vaccination services, rates of initiation were low. Expanding clinic outreach in this urban area is likely more important than increasing geographic access to the

  3. Coronary Arteries Segmentation Based on the 3D Discrete Wavelet Transform and 3D Neutrosophic Transform

    Directory of Open Access Journals (Sweden)

    Shuo-Tsung Chen

    2015-01-01

    Full Text Available Purpose. Most applications in the field of medical image processing require precise estimation. To improve the accuracy of segmentation, this study aimed to propose a novel segmentation method for coronary arteries to allow for the automatic and accurate detection of coronary pathologies. Methods. The proposed segmentation method included 2 parts. First, 3D region growing was applied to give the initial segmentation of coronary arteries. Next, the location of vessel information, HHH subband coefficients of the 3D DWT, was detected by the proposed vessel-texture discrimination algorithm. Based on the initial segmentation, 3D DWT integrated with the 3D neutrosophic transformation could accurately detect the coronary arteries. Results. Each subbranch of the segmented coronary arteries was segmented correctly by the proposed method. The obtained results are compared with those ground truth values obtained from the commercial software from GE Healthcare and the level-set method proposed by Yang et al., 2007. Results indicate that the proposed method is better in terms of efficiency analyzed. Conclusion. Based on the initial segmentation of coronary arteries obtained from 3D region growing, one-level 3D DWT and 3D neutrosophic transformation can be applied to detect coronary pathologies accurately.

  4. A Two-Step Segmentation Method for Breast Ultrasound Masses Based on Multi-resolution Analysis.

    Science.gov (United States)

    Rodrigues, Rafael; Braz, Rui; Pereira, Manuela; Moutinho, José; Pinheiro, Antonio M G

    2015-06-01

    Breast ultrasound images have several attractive properties that make them an interesting tool in breast cancer detection. However, their intrinsic high noise rate and low contrast turn mass detection and segmentation into a challenging task. In this article, a fully automated two-stage breast mass segmentation approach is proposed. In the initial stage, ultrasound images are segmented using support vector machine or discriminant analysis pixel classification with a multiresolution pixel descriptor. The features are extracted using non-linear diffusion, bandpass filtering and scale-variant mean curvature measures. A set of heuristic rules complement the initial segmentation stage, selecting the region of interest in a fully automated manner. In the second segmentation stage, refined segmentation of the area retrieved in the first stage is attempted, using two different techniques. The AdaBoost algorithm uses a descriptor based on scale-variant curvature measures and non-linear diffusion of the original image at lower scales, to improve the spatial accuracy of the ROI. Active contours use the segmentation results from the first stage as initial contours. Results for both proposed segmentation paths were promising, with normalized Dice similarity coefficients of 0.824 for AdaBoost and 0.813 for active contours. Recall rates were 79.6% for AdaBoost and 77.8% for active contours, whereas the precision rate was 89.3% for both methods. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    Method for supervised segmentation of volumetric data. The method is trained from manual annotations, and these annotations make the method very flexible, which we demonstrate in our experiments. Our method infers label information locally by matching the pattern in a neighborhood around a voxel ...... to a dictionary, and hereby accounts for the volume texture....

  6. Segmental Colitis Complicating Diverticular Disease

    Directory of Open Access Journals (Sweden)

    Guido Ma Van Rosendaal

    1996-01-01

    Full Text Available Two cases of idiopathic colitis affecting the sigmoid colon in elderly patients with underlying diverticulosis are presented. Segmental resection has permitted close review of the histopathology in this syndrome which demonstrates considerable similarity to changes seen in idiopathic ulcerative colitis. The reported experience with this syndrome and its clinical features are reviewed.

  7. Leaf segmentation in plant phenotyping

    NARCIS (Netherlands)

    Scharr, Hanno; Minervini, Massimo; French, Andrew P.; Klukas, Christian; Kramer, David M.; Liu, Xiaoming; Luengo, Imanol; Pape, Jean Michel; Polder, Gerrit; Vukadinovic, Danijela; Yin, Xi; Tsaftaris, Sotirios A.

    2016-01-01

    Image-based plant phenotyping is a growing application area of computer vision in agriculture. A key task is the segmentation of all individual leaves in images. Here we focus on the most common rosette model plants, Arabidopsis and young tobacco. Although leaves do share appearance and shape

  8. Body segments and growth hormone.

    OpenAIRE

    Bundak, R; Hindmarsh, P C; Brook, C G

    1988-01-01

    The effects of human growth hormone treatment for five years on sitting height and subischial leg length of 35 prepubertal children with isolated growth hormone deficiency were investigated. Body segments reacted equally to treatment with human growth hormone; this is important when comparing the effect of growth hormone on the growth of children with skeletal dysplasias or after spinal irradiation.

  9. Keratoplasty following anterior segment trauma.

    Science.gov (United States)

    Robinson, L P

    1981-02-01

    This paper reports and analyses 20 keratoplasties with or without anterior segment reconstruction carried out for penetrating injuries of the anterior segment. The results show that 80% clear grafts were achieved and 65% of eyes had vision restored to 6/18 or better. No eyes were lost. The complications were retinal detachments 2 cases, corneal graft rejection 2 cases, glaucoma 4 cases (2 mild and easily controlled) and one each of amblyopia and retinal folds through macular area. Eyes that have "quietened" following severe penetrating injuries of the anterior segment should be considered for penetrating keratoplasty and anterior segment reconstruction if they retain normal intraocular pressures and have vision of at least accurate projection of light in all quadrants. As well as achieving clear grafts and improvement of vision as above, all eyes had better cosmetic appearance. Two eyes had an ipsilateral rotational autokeratoplasty. This technique has a role to play when central scarring can be rotated to the periphery if sufficient undamaged cornea remains and interference with angle structures can be minimised.

  10. Automatic Segmentation of Dermoscopic Images by Iterative Classification

    Directory of Open Access Journals (Sweden)

    Maciel Zortea

    2011-01-01

    Full Text Available Accurate detection of the borders of skin lesions is a vital first step for computer aided diagnostic systems. This paper presents a novel automatic approach to segmentation of skin lesions that is particularly suitable for analysis of dermoscopic images. Assumptions about the image acquisition, in particular, the approximate location and color, are used to derive an automatic rule to select small seed regions, likely to correspond to samples of skin and the lesion of interest. The seed regions are used as initial training samples, and the lesion segmentation problem is treated as binary classification problem. An iterative hybrid classification strategy, based on a weighted combination of estimated posteriors of a linear and quadratic classifier, is used to update both the automatically selected training samples and the segmentation, increasing reliability and final accuracy, especially for those challenging images, where the contrast between the background skin and lesion is low.

  11. Image segmentation via foreground and background semantic descriptors

    Science.gov (United States)

    Yuan, Ding; Qiang, Jingjing; Yin, Jihao

    2017-09-01

    In the field of image processing, it has been a challenging task to obtain a complete foreground that is not uniform in color or texture. Unlike other methods, which segment the image by only using low-level features, we present a segmentation framework, in which high-level visual features, such as semantic information, are used. First, the initial semantic labels were obtained by using the nonparametric method. Then, a subset of the training images, with a similar foreground to the input image, was selected. Consequently, the semantic labels could be further refined according to the subset. Finally, the input image was segmented by integrating the object affinity and refined semantic labels. State-of-the-art performance was achieved in experiments with the challenging MSRC 21 dataset.

  12. Influence of Early Bisphosphonate Administration for Fracture Healing in Patients with Osteoporotic Proximal Humerus Fractures.

    Science.gov (United States)

    Seo, Joong-Bae; Yoo, Jae-Sung; Ryu, Jee-Won; Yu, Kun-Woong

    2016-12-01

    Bisphosphonates are generally known to adversely affect fracture healing because they inhibit osteoclastic bone resorption. However, some authors argue that bisphosphonates have no adverse effect on the restoration of the mechanical integrity of long bones after fractures. It is unclear whether bisphosphonates can be initiated safely in patients with acute proximal humerus fractures. The aim of this study was to determine whether the early use of a bisphosphonate affects healing and outcomes of osteoporotic proximal humerus fractures treated with a locking compression plate. Between August 2004 and June 2013, a total of 82 osteoporotic patients who underwent locking plate fixation of proximal humerus fractures were enrolled retrospectively. The patients were divided into two groups according to the timing of the commencement of treatment with alendronate after surgery: group A (n = 34, initiation of the bisphosphonate treatment within two weeks after surgery) and group B (n = 48, control group, initiation of the treatment three months after surgery). Patients were assessed for radiographic union at 2, 6, 10, and 16 weeks, 6 months, and 1 year after surgery. Clinical assessments were performed using the Constant score and American Shoulder and Elbow Surgeons (ASES) score at 1 year after surgery. No significant differences were observed between the two groups with respect to radiographic and clinical outcomes after locking plate fixation. All patients obtained fracture union, and the mean time to radiographic union was similar in group A and group B (6.3 and 6.6 weeks, respectively; p = 0.67). This study shows that the early initiation of bisphosphonate treatment does not affect bone union or clinical outcomes in patients with an osteoporotic proximal humerus fracture treated by locking compression plate fixation.

  13. Rehabilitation and Prevention of Proximal Hamstring Tendinopathy.

    Science.gov (United States)

    Beatty, Nicholas R; Félix, Ioonna; Hettler, Jessica; Moley, Peter J; Wyss, James F

    Proximal hamstring tendinopathy (PHT) comprises a small but significant portion of hamstring injuries in athletes, especially runners. PHT is a chronic condition that is clinically diagnosed but can be supported with imaging. The main presenting complaint is pain in the lower gluteal or ischial region that may or may not radiate along the hamstrings in the posterior thigh. There is little scientific evidence on which to base the rehabilitation management of PHT. Treatment is almost always conservative, with a focus on activity modification, addressing contributing biomechanical deficiencies, effective tendon loading including eccentric training, and ultrasound-guided interventional procedures which may facilitate rehabilitation. Surgery is limited to recalcitrant cases or those involving concomitant high-grade musculotendinous pathology. The keys to PHT management include early and accurate diagnosis, optimal rehabilitation to allow for a safe return to preinjury activity level, and preventative strategies to reduce risk of reinjury.

  14. DC Proximal Newton for Nonconvex Optimization Problems.

    Science.gov (United States)

    Rakotomamonjy, Alain; Flamary, Rémi; Gasso, Gilles

    2016-03-01

    We introduce a novel algorithm for solving learning problems where both the loss function and the regularizer are nonconvex but belong to the class of difference of convex (DC) functions. Our contribution is a new general purpose proximal Newton algorithm that is able to deal with such a situation. The algorithm consists in obtaining a descent direction from an approximation of the loss function and then in performing a line search to ensure a sufficient descent. A theoretical analysis is provided showing that the iterates of the proposed algorithm admit as limit points stationary points of the DC objective function. Numerical experiments show that our approach is more efficient than the current state of the art for a problem with a convex loss function and a nonconvex regularizer. We have also illustrated the benefit of our algorithm in high-dimensional transductive learning problem where both the loss function and regularizers are nonconvex.

  15. Proximity Effects in Superconductor-Graphene Junctions

    Science.gov (United States)

    Cuellar, Fabian A.; Perconte, David; Martin, Marie-Blandine; Dlubak, Bruno; Piquemail, Maelis; Bernard, Rozenn; Trastoy, Juan; Moreau-Luchaire, Constance; Seneor, Pierre; Villegas, Javier E.; Kidambi, Piran; Hofmann, Stephan; Robertson, John

    2015-03-01

    Superconducting proximity effects are of particular interest in graphene: because of its band structure, an unconventional (specular) Andreev reflection is expected. In this context, high-Tc superconductor-graphene junctions are especially attractive. In these, the size of the superconducting energy-gap may exceed the graphene doping inhomogeneities around the Dirac point, which should favor the observation of the specular Andreev reflection. Yet, the fabrication of high-Tc superconductor-graphene junctions is challenging: the usual growth and lithography processes in both materials are incompatible. We report here on a fabrication method that allow us to fabricate planar cuprate superconductor-graphene junctions, which we characterize via conductance spectroscopy. We analyze the features in the conductance spectra as a function of graphene doping, and discuss them in the framework of the Andreev reflection. Work supported by Labex Nanosaclay.

  16. Phonon engineering in proximity enhanced superconductor heterostructures.

    Science.gov (United States)

    Tang, Yong-Chao; Kwon, Sangil; Mohebbi, Hamid R; Cory, David G; Miao, Guo-Xing

    2017-06-27

    In this research, we tailor the phonon density of states (DOS) in thin superconducting films to suppress quasiparticle losses. We examine a model system of a proximity-enhanced three-layered Al/Nb/Al heterostructure and show that the local quantized phonon spectrum of the ultrathin Al cladding layers in the heterostructure has a pronounced effect on the superconducting resonator's quality factors. Instead of a monotonic increase of quality factors with decreasing temperatures, we observe the quality factor reaches a maximum at 1.2 K in 5/50/5 nm Al/Nb/Al microstrip resonators, because of a quantized phonon ladder. The phonon DOS may be engineered to enhance the performance of quantum devices.

  17. Joint shape segmentation with linear programming

    KAUST Repository

    Huang, Qixing

    2011-01-01

    We present an approach to segmenting shapes in a heterogenous shape database. Our approach segments the shapes jointly, utilizing features from multiple shapes to improve the segmentation of each. The approach is entirely unsupervised and is based on an integer quadratic programming formulation of the joint segmentation problem. The program optimizes over possible segmentations of individual shapes as well as over possible correspondences between segments from multiple shapes. The integer quadratic program is solved via a linear programming relaxation, using a block coordinate descent procedure that makes the optimization feasible for large databases. We evaluate the presented approach on the Princeton segmentation benchmark and show that joint shape segmentation significantly outperforms single-shape segmentation techniques. © 2011 ACM.

  18. A novel reporting approach to coronary angiography: "segmental coding system".

    Science.gov (United States)

    Konuralp, Cüneyt; Idiz, Mustafa; Ateş, Mehmet

    2005-01-01

    A new systematic reporting system for coronary angiography has been developed, which is capable of describing any visible intraluminal or extraluminal conditions with the exact coordinates. In this method, called "segmental coding system"(SCS), the part of the artery that is located between its two subsequent branches is considered to be an "angiographic segment". Conditions are localized according to their relationship with these angiographic segments and the anatomic border of the segments (coronary ostiums, primary, secondary and tertiary branches, grafts and proximal and distal anastomosis sites). They are also described by using a special coding system that consists of letters, numbers and signs. SCS can supply the name (stenosis, occlusion, contour deformity, aneurysm, rupture, anatomical variation, existence of stent, etc.) and the exact localization (coordinates) of the condition with its properties; filling direction, and the collateral system that fills the vessel. We applied SCS to more than 500 cineangiograpies. According to our experience, SCS provides more objective, detailed, and even correct information than the current narrative reporting system. SCS also offers many extra advantages. (a) It can describe all imaginable types of lesion combinations. (b) All of the existing conditions can be listed without missing. (c) The definitions are very precise and clear. They can easily be understood by everyone in the same way. (d) It is more advantageous on archiving, searching the database, and comparing the subsequent reports for the same patient. (e) In the future, by using specially tailored software, personal and detailed angiographic images will be reproduced from the SCS data. By being introduced into clinical practice, we believe, SCS will prove a very useful tool for both surgeons and cardiologists.

  19. Treatment of segmental tibial fractures with supercutaneous plating.

    Science.gov (United States)

    He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

    2014-08-01

    Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. Copyright 2014, SLACK Incorporated.

  20. Mouse model of proximal tubule endocytic dysfunction.

    Science.gov (United States)

    Weyer, Kathrin; Storm, Tina; Shan, Jingdong; Vainio, Seppo; Kozyraki, Renata; Verroust, Pierre J; Christensen, Erik I; Nielsen, Rikke

    2011-11-01

    Several studies have indicated the central role of the megalin/cubilin multiligand endocytic receptor complex in protein reabsorption in the kidney proximal tubule. However, the poor viability of the existing megalin-deficient mice precludes further studies and comparison of homogeneous groups of mice. Megalin- and/or cubilin-deficient mice were generated using a conditional Cre-loxP system, where the Cre gene is driven by the Wnt4 promoter. Kidney tissues from the mice were analysed for megalin and cubilin expression by quantitative reverse transcription-polymerase chain reaction, western blotting and immunohistochemistry. Renal albumin uptake was visualized by immunohistochemistry. Twenty-four-hour urine samples were collected in metabolic cages and analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting. Urinary albumin/creatinine ratios were measured by ELISA and the alkaline picrate method. The Meg(lox/lox);Cre(+), Cubn(lox/lox);Cre(+) and Meg(lox/lox), Cubn(lox/lox);Cre(+) mice were all viable, fertile and developed normal kidneys. Megalin and/or cubilin expression, assessed by immunohistology and western blotting, was reduced by >89%. Consistent with this observation, the mice excreted megalin and cubilin ligands such as transferrin and albumin in addition to low-molecular weight proteins. We further show that megalin/cubilin double-deficient mice excrete albumin with an average of 1.45 ± 0.54 mg/day, suggesting a very low albumin concentration in the glomerular ultrafiltrate. We report here the efficient genetic ablation of megalin, cubilin or both, using a Cre transgene driven by the Wnt4 promoter. The viable megalin/cubilin double-deficient mice now allow for detailed large-scale group analysis, and we anticipate that the mice will be of great value as an animal model for proximal tubulopathies with disrupted endocytosis.