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Sample records for failed filtering blebs

  1. Rescue of failed filtering blebs with ab interno trephination.

    PubMed

    Shihadeh, Wisam A; Ritch, Robert; Liebmann, Jeffrey M

    2006-06-01

    We evaluated the effectiveness of ab interno automated trephination as a technique for rescuing failed mature filtering blebs. A retrospective chart review of 40 failed blebs of 38 patients who had a posttrephination follow-up period of at least 3 months was done. With success defined as intraocular pressure (IOP) <21 mm Hg and at least a 20% reduction from baseline on the same or fewer number of pretrephination medications, 30/40 eyes (75%) fit these criteria over the entire course of follow-up. Among all 40 eyes, there was a significant reduction of IOP from pretrephination to 3 months (P<.001). The percentage of patients requiring 2 or more medications declined from 90% pretrephination to 21% at 3 months (P<.0001), and was stable thereafter. Some patients were able to eliminate all medications. Patients who did not meet the criteria of success regained successful IOP control with other modalities of management. Complications were few. We believe that ab interno trephination is an excellent option for rescuing selected failed filtering blebs.

  2. The relationship of bleb morphology and the outcome of needle revision with 5-fluorouracil in failing filtering bleb

    PubMed Central

    Lee, Yung-Sung; Wu, Shiu-Chen; Tseng, Hsiao-Jung; Wu, Wei-Chi; Chang, Shirley H.L.

    2016-01-01

    Abstract To investigate the risk factors for failure of needling revision with 5-fluorouracil (5-FU) and to identify the correlation of outcomes of needling revision and the morphological features of dysfunctional filtration blebs using Moorfields bleb grading system. This retrospective, nonrandomized, comparative case–control study included 41 consecutive patients (41 eyes) who underwent 5-FU needling revision for failed or failing filtration blebs between July 2012 and August 2014 in Chang Gung Memorial Hospital, a referral center in Taiwan. The main outcome measures were the bleb survival and the correlation factors of bleb morphology before revision. The secondary outcome measure was the identification of any study factor associated with bleb failure. Forty-one eyes of 41 patients were included in this study. The most frequent glaucoma diagnoses were 10 cases (24%) of neovascular glaucoma and 8 cases (19%) of chronic open-angle glaucoma. Survival of bleb at 6, 12, and 24 months was 42%, 39%, and 23%. Fourteen cases (34%) maintained overall success at the last follow-up, with an average follow-up of 22.7 ± 9.4 months (range: 12–48 months). The central bleb area and height were significantly different between the successful needling group and the failed needling group (P = 0.03 and 0.04, respectively). Further trend test confirmed that smaller central bleb extension and flatter height were associated with a higher chance of failure (P = 0.02 and 0.02, respectively). Time from initial trabeculectomy to needling of less than 4 months and higher intraocular pressure (IOP) in the first postoperative week also led to significantly higher risk for failure (P = 0.01 and 0.03, respectively). A small central area and the flat height of dysfunctional blebs were more likely to fail after the needle revision. Cautious case selections, taking account of the time from the initial filtering surgery and postoperative IOP, may improve the surgical outcome. PMID:27603345

  3. The relationship of bleb morphology and the outcome of needle revision with 5-fluorouracil in failing filtering bleb.

    PubMed

    Lee, Yung-Sung; Wu, Shiu-Chen; Tseng, Hsiao-Jung; Wu, Wei-Chi; Chang, Shirley H L

    2016-09-01

    To investigate the risk factors for failure of needling revision with 5-fluorouracil (5-FU) and to identify the correlation of outcomes of needling revision and the morphological features of dysfunctional filtration blebs using Moorfields bleb grading system.This retrospective, nonrandomized, comparative case-control study included 41 consecutive patients (41 eyes) who underwent 5-FU needling revision for failed or failing filtration blebs between July 2012 and August 2014 in Chang Gung Memorial Hospital, a referral center in Taiwan. The main outcome measures were the bleb survival and the correlation factors of bleb morphology before revision. The secondary outcome measure was the identification of any study factor associated with bleb failure.Forty-one eyes of 41 patients were included in this study. The most frequent glaucoma diagnoses were 10 cases (24%) of neovascular glaucoma and 8 cases (19%) of chronic open-angle glaucoma. Survival of bleb at 6, 12, and 24 months was 42%, 39%, and 23%. Fourteen cases (34%) maintained overall success at the last follow-up, with an average follow-up of 22.7 ± 9.4 months (range: 12-48 months). The central bleb area and height were significantly different between the successful needling group and the failed needling group (P = 0.03 and 0.04, respectively). Further trend test confirmed that smaller central bleb extension and flatter height were associated with a higher chance of failure (P = 0.02 and 0.02, respectively). Time from initial trabeculectomy to needling of less than 4 months and higher intraocular pressure (IOP) in the first postoperative week also led to significantly higher risk for failure (P = 0.01 and 0.03, respectively).A small central area and the flat height of dysfunctional blebs were more likely to fail after the needle revision. Cautious case selections, taking account of the time from the initial filtering surgery and postoperative IOP, may improve the surgical outcome. PMID:27603345

  4. Anterior Segment Optical Coherence Tomography Imaging of Conjunctival Filtering Blebs after Glaucoma Surgery

    PubMed Central

    Mastropasqua, Rodolfo; Fasanella, Vincenzo; Curcio, Claudia; Ciancaglini, Marco

    2014-01-01

    Time domain (TD) and spectral domain (SD) optical coherence tomography (OCT) are cross-sectional, noncontact, high-resolution diagnostic modalities for posterior and anterior segment (AS) imaging. The AS-OCT provides tomographic imaging of the cornea, iris, lens, and anterior chamber (AC) angle in several ophthalmic diseases. In glaucoma, AS-OCT is utilized to evaluate the morphology of AS structures involved in the pathogenesis of the disease, to obtain morphometric measures of the AC, to evaluate the suitability for laser or surgical approaches, and to assess modifications after treatment. In patients undergoing surgery, AS-OCT is crucial in the evaluation of the filtering bleb functionality, permitting a combined qualitative and quantitative analysis. In this field, AS-OCT may help clinicians in distinguishing between functioning and nonfunctioning blebs by classifying their macroscopic morphology, describing bleb-wall features, bleb cavity, and scleral opening. This information is critical in recognizing signs of filtration failure earlier than the clinical approach and in planning the appropriate timing for management procedures in failing blebs. In this review, we summarize the applications of AS-OCT in the conjunctival bleb assessment. PMID:25136603

  5. Augmentation of Filtering Blebs with Viscoelastics in Trabeculectomy

    PubMed Central

    Jeong, Hyerin

    2014-01-01

    Purpose To evaluate the clinical outcome of viscoelastics (VE, sodium hyaluronate)-augmented trabeculectomy (VAT, 66 eyes) and conventional trabeculectomy (CT, 57 eyes) for glaucomatous eyes. Methods In the VAT group, half of the anterior chamber space was filled with VE via the paracentesis site at the end of CT and a balanced salt solution was injected into the anterior chamber. This procedure induced migration of VE from the anterior chamber into the bleb space; thus the bleb was elevated with underlying VE. Follow-up examinations were performed until 1 year after surgery. Success was defined as the attainment of an intraocular pressure (IOP) greater than 5 mmHg and less than 22 mmHg. If IOP was in the range of success without antiglaucoma medication, it was regarded as a complete success. Results The mean postoperative IOP was significantly lower in the VAT group at postoperative 1 day, 1 week, and 1 month. The complete success rate was significantly higher in the VAT group (89%) than in the CT group (75%), though the qualified success rate was not different between the two groups. The number of IOP-lowering medications at postoperative 1 year was significantly higher in the CT group (1.30 ± 1.08 vs. 0.73 ± 0.98, p = 0.003). Among postoperative procedures, laser suture lysis was required less frequently in the VAT group (p < 0.001). Conclusions Placing VE within the bleb at the end of surgery may result in better IOP control and less need for IOP-lowering medication without any additional materials, cost, or time. PMID:25276081

  6. Dry Eye Disease in Patients with Functioning Filtering Blebs after Trabeculectomy

    PubMed Central

    Ji, Hong; Zhu, Yingting; Zhang, Yingying; Li, Zuohong; Ge, Jian; Zhuo, Yehong

    2016-01-01

    Purpose The aim of this study was to analyze dry eye disease (DED) in patients with functioning filtering blebs and to explore the relationship between the morphology of filtering blebs and ocular surface instability. Methods This was a cross-sectional, case-comparison study. Seventy glaucomatous patients (70 eyes) with functioning blebs who had undergone trabeculectomy more than 6 months prior (study group) and 35 control subjects (35 eyes) (control group) were included. All subjects completed an ocular symptom questionnaire that referred to the Shihpai Eye Study. Evaluation of meibomian gland obstruction, a tear film break-up time test (TFBUT), fluorescein corneal staining and a Schirmer’s tear test were then performed. Filtering bleb morphology was analyzed using Wuerzburg bleb classification scoring criteria in the study group. The presence of DED was defined as the concomitant presence of TFBUT <10 seconds and the presence of superficial punctate keratitis. Results The patients with functioning blebs presented higher corneal staining scores (P = 0.012) and lower TFBUT values (P = 0.043) than the control group. DED was present in 28/70 patients in the study group and 6/35 patients in the control group (P = 0.018). More patients in the study group complained of dryness (P = 0.001), a gritty or sandy sensation (P < 0.001) and redness (P = 0.048). In the study group, the patients with DED were significantly different from the patients without DED in both TFBUT (P < 0.001) and corneal staining (P < 0.001). More patients in the DED group were likely to report dryness (P = 0.013) and watery or teary eyes (P = 0.012). The differences in meibomian gland obstruction scores between the study and the control group, the DED and the non-DED group were not significant (P = 0.105 and P = 0.077, respectively). The values for microcysts and bleb heights were significantly higher in the DED group (P = 0.040 and P = 0.011, respectively). A Spearman’s rank correlation showed

  7. Evaluation of Filtering Bleb Function after Trabeculectomy with Mitomycin C Using Biomicroscopy, Anterior Segment Optical Coherence Tomography and In Vivo Confocal Microscopy

    PubMed Central

    Güven Yılmaz, Suzan; Değirmenci, Cumali; Palamar, Melis; Yağcı, Ayşe

    2015-01-01

    Objectives: To analyze and assess compatibility of trabeculectomy filtering bleb characteristics and appearances using biomicroscopy, anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM). Materials and Methods: Twenty-eight eyes of 28 patients who underwent glaucoma filtering surgery with mitomycin C in our clinic between 2009 and 2013 were evaluated. Morphological appearances of the blebs on slit-lamp biomicroscopy were defined according to the Moorfields bleb classification system. For the internal tissue assessment of blebs, AS-OCT and IVCM were performed. Bleb biometric parameters such as length, height and bleb wall thickness were assessed by AS-OCT; conjunctival epithelial-stromal cyst, structural network of conjunctival stroma and vascularisation were examined with IVCM. The relation between biomicroscopic morphological staging and bleb characteristics detected on AS-OCT and IVCM were assessed. Results: The mean age of the 28 patients (16 male, 12 female) was 57.2±15.9 (19 to 79) years. The mean time elapsed between surgery and examination was 29.2±19.2 (6 to 68) months. According to biomicroscopic appearance, 17 (60.7%) blebs were functional (13 diffuse, 4 microcystic), whereas 11 (39.3%) blebs were non-functional (9 flat, 2 encapsulated). In the comparison of non-functional and functional blebs, functional blebs were found to be superior in terms of biometric parameters on AS-OCT assessment (p<0.05). Higher number of epithelial and stromal cysts and less vascularisation were detected by IVCM in functional blebs when compared with non-functional blebs (p<0.05). Conclusion: Biomicroscopic appearances and characteristics on AS-OCT and IVCM of filtration blebs are consistent with each other. Besides biomicroscopic examination, which is an easy and practical method for determining bleb morphology, cross-sectional images obtained by AS-OCT and IVCM provide objective data regarding internal structure and functional

  8. Comparison of Subconjunctival Mitomycin C and 5-Fluorouracil Injection for Needle Revision of Early Failed Trabeculectomy Blebs

    PubMed Central

    Liu, Wei; Wang, Jianrong; Zhang, Miaomiao; Tao, Yuan; Sun, Yan

    2016-01-01

    Background. To compare the efficacy of needle revision with 5-fluorouracil (5-FU) and mitomycin C (MMC) on dysfunctional filtration blebs shortly after trabeculectomy. Methods. It is a prospective randomized study comparing needle revision augmented with MMC or 5-FU for failed trabeculectomy blebs. Results. To date 71 patients (75 eyes) have been enrolled, 40 eyes in the MMC group and 35 in the 5-FU group. 68 patients (72 eyes) have completed 12-month follow-up, 38 eyes in the MMC group and 34 in the 5-FU group. The mean IOP before and that after needle revision in the MMC group were 26.5 ± 4.3 mmHg and 11.3 ± 3.4 mmHg, respectively (P < 0.05), and in the 5-FU group were 27.1 ± 3.8 mmHg and 10.9 ± 3.4 mmHg, respectively (P < 0.05). At 12-month follow-up, complete success rates were 57.5% for MMC group and 34.3% for 5-FU group (P = 0.042; log-rank test) and 75% and 60% (P = 0.145; log-rank test), respectively, for the qualified success. Complication rates between the two groups were not statistically different (P > 0.05). Conclusions. Needle revision and subconjunctival MMC injection were more effective than needling and subconjunctival 5-FU injection for early dysfunctional filtration blebs after trabeculectomies. PMID:26989499

  9. Effect of Qingguangan on the expressions of MMP-2 and MMP-9 in filtering bleb after trabeculectomy in rabbits

    PubMed Central

    Li, Wen-Juan; Peng, Qing-Hua; Tan, Han-Yu; Liu, Yan

    2012-01-01

    AIM To explore the effect of Qingguangan on the expressions of MMP-2 and MMP-9 in filtering bleb scarring area after trabeculectomy in rabbit model. METHODS Thirty-two New Zealand rabbits were randomized into four groups: control group, experimental group, MMC group (ocular trabeculectomy in combination with MMC), and Qingguangan group. Trabeculectomy was performed on both eyes in each group except control group. Qingguangan group was mouth-fed with Qingguangan (solution). On postoperative day 14, the appearances of MMP-2 and MMP-9 on filtrating blebs were observed by immunohistochemistry. RESULTS Statistical differences of the expressions of MMP-2 and MMP-9 were noted among groups on day 14 following surgery. Histology immunohistochemistry showed significant differences on the expressions of MMP-2 and MMP-9 between each group (P<0.05). CONCLUSION Qingguangan can promote the expressions of MMP-2 and MMP-9. PMID:23275898

  10. Efficacy of repeated 5-fluorouracil needling for failing and failed filtering surgeries based on simple gonioscopic examination

    PubMed Central

    Rashad, Mohammad A

    2013-01-01

    Purpose To evaluate the success rate of a modified bleb needling technique in eyes with previous glaucoma surgery that had elevated intraocular pressure. Methods A retrospective study of 24 eyes of 24 patients that underwent repeated bleb needling performed for failing and failed blebs on slit lamp with 5-fluorouracil (5-FU) injections on demand. This was performed after gonioscopic examination to define levels of filtration block. Results There was significant reduction of mean IOP from 36.91 mmHg to 14.73 mmHg at the final follow-up (P < 0.001). The overall success rate was 92%. Conclusion Repeated needling with adjunctive 5-FU proved a highly effective, safe alternative to revive filtration surgery rather than another medication or surgery. PMID:23293510

  11. Anterior Segment Optical Coherence Tomography Imaging of Filtering Blebs after Deep Sclerectomy with Esnoper-Clip Implant: One-year Follow-up

    PubMed Central

    Noronha, Manuel; Lemos, Vanessa; Reina, Maria; Gomes, Teresa

    2014-01-01

    ABSTRACT Purpose: To describe the technique of deep sclerectomy with the new Esnoper-Clip® implant, the clinical outcome and the anatomic characteristics of filtering blebs, using anterior segment optical coherence tomography (AS-OCT). Methods: A prospective case-series study was conducted in five eyes (5 patients) with open angle glaucoma. The fornix-based deep sclerectomy with Esnoper-Clip® implant was done by the same surgeon. In one case, mitomycin C was used during surgery. All participants underwent a complete ophthalmic examination and AS-OCT (Visante®) preoperatively, then at each follow-up visit, at 1 day, 1 week, 1 month, 6 months and 1 year postoperatively. Scans were obtained through sagittal and transversal plans to the implant. Results: Intraocular pressure (IOP) was significantly reduced (p < 0.05) from a mean preoperative value of 23.4 ± 8.6 mm Hg (n = 3.8 glaucoma medications) to a postoperative value of 6.0 ± 2.5 (n = 0), 10.6 ± 5.4 (n = 0), 13 ± 1.6 (n = 0.4), 12.4 ± 2.1 (n = 0.2) and 14.4 ± 1.5 (n = 0.2) at 1 day, 1 week, 1 month, 6 months and 1 year respectively. AS-OCT allowed the visualization of the two plates of the implant (scleral and suprasciliary), the trabeculodescemetic membrane and the hyporeflective spaces in the bleb wall thickness and in suprascleral and suprachoroidal localizations. An immediate postoperative hypotony and an anteriorization of the implant associated to trabeculodescemetic membrane rupture, were detected, although without significant clinical repercussions. Conclusion: Our first five deep sclerectomy with Esnoper-Clip implantation analysis suggest an effective and well-tolerated method to reduce IOP. AS-OCT is a noninvasive imaging technique that allows the anatomic analysis of the drainage mechanisms after glaucoma surgery. How to cite this article: Vieira L, Noronha M, Lemos V, Reina M, Gomes T. Anterior Segment Optical Coherence Tomography Imaging of Filtering Blebs after Deep Sclerectomy with Esnoper

  12. Fail save shut off valve for filtering systems employing candle filters

    DOEpatents

    VanOsdol, John

    2006-01-03

    The invention relates to an apparatus that acts as a fail save shut off valve. More specifically, the invention relates to a fail save shut off valve that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over-pressurization. The present invention is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system the present invention stops the flow of hot gas and prevents any particulate laden gas from entering the clean side of the system.

  13. Fail Save Shut Off Valve for Filtering Systems Employing Candle Filters

    SciTech Connect

    VanOsdol, John

    2006-01-03

    The invention relates to an apparatus that acts as a fail save shut off valve. More specifically, the invention relates to a fail save shut off valve that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over-pressurization. The present invention is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system the present invention stops the flow of hot gas and prevents any particulate laden gas from entering the clean side of the system.

  14. Preparation of Metal Filter Element for Fail Safety in IGCC Filter Unit

    SciTech Connect

    Choi, J-H.; Ahn, I-S.; Bak, Y-C.; Bae, S-Y.; Ha, S-J.; Jang, H-J.

    2002-09-18

    Metal filter elements as the fail safety filter are fabricated by the methods using cold isostatic pressure (compress method) and binder (binder method) to form the filter element and tested in a experimental and bench units. The fail safety filter on the filtration system is mounted additionally in order to intercept the particle leak when the main filter element is broken. So it should have two contrary functions of a high permeability and being plugged easily. The filter element having high porosity and high plugging property was fabricated by the bind method. It has the porosity more than 50%, showed very small pressure drop less than 10mmH2O at the face velocity of 0.15m/s, and plugged within 5 minutes with the inhibition of the particle leak larger than 4 {micro}m. The test result of corrosion tendency in IGCC gas stream at 500 C shows SUS310L material is very reasonable among SUS310, SUS316, Inconel 600, and Hastelloy X.

  15. A New Method for Revision of Encapsulated Blebs after Trabeculectomy: Combination of Standard Bleb Needling with Transconjunctival Scleral Flap Sutures Prevents Early Postoperative Hypotony

    PubMed Central

    Laspas, Panagiotis; Culmann, Philipp David; Grus, Franz Hermann; Prokosch-Willing, Verena; Poplawksi, Alicia; Pfeiffer, Norbert; Hoffmann, Esther Maria

    2016-01-01

    Purpose A simple needling procedure is the standard method for restoring the function of an encapsulated bleb after trabeculectomy. However, postoperative hypotony represents a possible hazard. This study describes a new surgical approach for treating encapsulated blebs with reduced risk of early postoperative hypotony: bleb needling combined with transconjunctival sutures tightening the scleral flap directly. Methods The study included two groups of 23 patients with failing bleb following trabeculectomy: “Group 1” underwent simple needling revision of the filtering bleb and served as a control group, while “Group 2” received needling revision with additional transconjunctival scleral flap sutures, if intraoperatively the intraocular pressure was estimated to be very low. Intraocular pressure (IOP), postoperative management and complications were analyzed over a follow-up period of 4 weeks postoperatively. Results were compared using t-test or Mann-Whitney U-tests. Results Adverse effects occurred with a higher frequency after sole needling of the bleb (5 cases of choroidal effusion and 1 case of choroidal hemorrhage) than after the combined method with additional scleral sutures (1 case of choroidal effusion). The IOP on the first postoperative day was significantly lower in group 1, with 9.43 ± 9.01 mm Hg vs. 16.43 ± 8.35 mm Hg in group 2 (P = 0.01). Ten patients with ocular hypotony (IOD of 5 mmHg or lower) were found in group 1 and only two in group 2. One week and one month after surgery the intraocular pressure was similar in both groups (P>0.05). Conclusions This new needling technique with additional transconjunctival scleral flap sutures appears to reduce postoperative hypotony, and may thus protect from further complications, such as subchoroidal hemorrhage. PMID:27314495

  16. Assessment of Snared-Loop Technique When Standard Retrieval of Inferior Vena Cava Filters Fails

    SciTech Connect

    Doody, Orla Noe, Geertje; Given, Mark F.; Foley, Peter T.; Lyon, Stuart M.

    2009-01-15

    Purpose To identify the success and complications related to a variant technique used to retrieve inferior vena cava filters when simple snare approach has failed. Methods A retrospective review of all Cook Guenther Tulip filters and Cook Celect filters retrieved between July 2006 and February 2008 was performed. During this period, 130 filter retrievals were attempted. In 33 cases, the standard retrieval technique failed. Retrieval was subsequently attempted with our modified retrieval technique. Results The retrieval was successful in 23 cases (mean dwell time, 171.84 days; range, 5-505 days) and unsuccessful in 10 cases (mean dwell time, 162.2 days; range, 94-360 days). Our filter retrievability rates increased from 74.6% with the standard retrieval method to 92.3% when the snared-loop technique was used. Unsuccessful retrieval was due to significant endothelialization (n = 9) and caval penetration by the filter (n = 1). A single complication occurred in the group, in a patient developing pulmonary emboli after attempted retrieval. Conclusion The technique we describe increased the retrievability of the two filters studied. Hook endothelialization is the main factor resulting in failed retrieval and continues to be a limitation with these filters.

  17. Wound healing in glaucoma filtering surgery.

    PubMed

    Skuta, G L; Parrish, R K

    1987-01-01

    Successful glaucoma filtering surgery is characterized by the passage of aqueous humor from the anterior chamber to the subconjunctival space, which results in the formation of a filtering bleb. Aqueous in the subconjunctival space may then exit by multiple pathways. Bleb failure most often results from fibroblast proliferation and subconjunctival fibrosis. Factors associated with an increased risk of bleb failure include youth, aphakia, active anterior segment neovascularization, inflammation, previously failed glaucoma filtering surgery, and, possibly, race. Several surgical and pharmacologic techniques have recently been introduced to enhance success in eyes with poor surgical prognoses. To elucidate the scientific rationale of these methods, we summarize the process of wound healing after glaucoma filtering surgery and describe postoperative clinical and histopathologic features, factors which may affect success, and specific methods to improve surgical success.

  18. Bleb incarceration following Ahmed valve surgery

    PubMed Central

    Gross, Fredric J; DiSandro, Giovanni

    2016-01-01

    Globe luxation is a painful and potentially vision-threatening condition in which the globe becomes trapped behind the eyelids requiring physician intervention in the emergency department or eye clinic. On presentation, the patient typically complains of an inability to close their eye, severe foreign body sensation, decreased vision, and significant eye pain. Although most visual symptoms are reversible and primarily result from exposure keratopathy, optic nerve damage, and permanent vision loss can occur from repeat or prolonged episodes of globe luxation. Risk factors include any congenital or acquired conditions that displace the globe anteriorly in the orbit and increased eyelid laxity that allows the globe to prolapse through the lid aperture. Typically, the precipitating event involves eyelid retraction during ophthalmic examination or an event that increases intraorbital pressure such as coughing or sneezing. Once the globe has luxated, the condition is typically worsened by blepharospasm and patients’ attempts to close the eye that worsen the entrapment. In the current case, the patient had a large superotemporal filtering bleb following Ahmed valve surgery for uncontrolled glaucoma. While instilling her glaucoma medication, she retracted her eyelids sufficiently to pull the upper lid over her filtering bleb where it became entrapped causing a similar presentation to globe luxation. Traditional methods of repositioning the globe were unsuccessful. Bleb needling was ultimately required to return the globe to a normal position. PMID:27799829

  19. Bleb Nucleation through Membrane Peeling

    NASA Astrophysics Data System (ADS)

    Alert, Ricard; Casademunt, Jaume

    2016-02-01

    We study the nucleation of blebs, i.e., protrusions arising from a local detachment of the membrane from the cortex of a cell. Based on a simple model of elastic linkers with force-dependent kinetics, we show that bleb nucleation is governed by membrane peeling. By this mechanism, the growth or shrinkage of a detached membrane patch is completely determined by the linker kinetics, regardless of the energetic cost of the detachment. We predict the critical nucleation radius for membrane peeling and the corresponding effective energy barrier. These may be typically smaller than those predicted by classical nucleation theory, implying a much faster nucleation. We also perform simulations of a continuum stochastic model of membrane-cortex adhesion to obtain the statistics of bleb nucleation times as a function of the stress on the membrane. The determinant role of membrane peeling changes our understanding of bleb nucleation and opens new directions in the study of blebs.

  20. Chemotactic Blebbing in Dictyostelium Cells.

    PubMed

    Zatulovskiy, Evgeny; Kay, Robert R

    2016-01-01

    Many researchers use the social amoeba Dictyostelium discoideum as a model organism to study various aspects of the eukaryotic cell chemotaxis. Traditionally, Dictyostelium chemotaxis is considered to be driven mainly by branched F-actin polymerization. However, recently it has become evident that Dictyostelium, as well as many other eukaryotic cells, can also employ intracellular hydrostatic pressure to generate force for migration. This process results in the projection of hemispherical plasma membrane protrusions, called blebs, that can be controlled by chemotactic signaling.Here we describe two methods to study chemotactic blebbing in Dictyostelium cells and to analyze the intensity of the blebbing response in various strains and under different conditions. The first of these methods-the cyclic-AMP shock assay-allows one to quantify the global blebbing response of cells to a uniform chemoattractant stimulation. The second one-the under-agarose migration assay-induces directional blebbing in cells moving in a gradient of chemoattractant. In this assay, the cells can be switched from a predominantly F-actin-driven mode of motility to a bleb-driven chemotaxis, allowing one to compare the efficiency of both modes and explore the molecular machinery controlling chemotactic blebbing. PMID:27271896

  1. Axonal bleb recording.

    PubMed

    Hu, Wenqin; Shu, Yousheng

    2012-08-01

    Patch-clamp recording requires direct accessibility of the cell membrane to patch pipettes and allows the investigation of ion channel properties and functions in specific cellular compartments. The cell body and relatively thick dendrites are the most accessible compartments of a neuron, due to their large diameters and therefore great membrane surface areas. However, axons are normally inaccessible to patch pipettes because of their thin structure; thus studies of axon physiology have long been hampered by the lack of axon recording methods. Recently, a new method of patch-clamp recording has been developed, enabling direct and tight-seal recording from cortical axons. These recordings are performed at the enlarged structure (axonal bleb) formed at the cut end of an axon after slicing procedures. This method has facilitated studies of the mechanisms underlying the generation and propagation of the main output signal, the action potential, and led to the finding that cortical neurons communicate not only in action potential-mediated digital mode but also in membrane potential-dependent analog mode. PMID:22833034

  2. Failed Retrieval of an Inferior Vena Cava Filter During Pregnancy Because of Filter Tilt: Report of Two Cases

    SciTech Connect

    McConville, R. M. Kennedy, P. T.; Collins, A. J.; Ellis, P. K.

    2009-01-15

    Thromboembolic disease during pregnancy is an important cause of obstetric morbidity and mortality. Pregnant patients with venous thromboembolism are usually managed by conventional anticoagulation. However, this must be discontinued during vaginal or caesarian delivery to avoid haemorrhage and to reduce the risk of possible epidural haematoma. Retrievable inferior vena cava filters (IVCFs) offer protection against pulmonary embolism during this high-risk period, when anticoagulation is discontinued, while avoiding potential long-term sequelae of a permanent IVCF. Here we report two patients who presented in the third trimester of pregnancy with floating ileofemoral deep vein thrombosis. Both patients were initially treated with standard anticoagulation; however, shortly before delivery both patients had a retrievable IVCF placed in a suprarenal position. In both patients, retrieval failed at 28 days after insertion because of filter tilt. The timing and mechanism of filter tilt remains uncertain. We believe that a number of factors could have been involved, including change in the anatomic configuration with lateral displacement of the IVCF as a result of the gravid uterus as well as forceful uterine contractions during labour, which modified the shape and diameter of the IVC. We showed that failure to retrieve the IVCF has had considerable implications for the two young patients regarding long-term anticoagulation and have highlighted the need for further clinical trials regarding the safe use of retrievable IVCFs during pregnancy.

  3. Blood, blebs and lumen expansion.

    PubMed

    Reichman-Fried, Michal; Raz, Erez

    2016-04-01

    A powerful combination of cell labelling, genetic tools and rapid imaging techniques in vivo has now led to a high-resolution description of lumen formation during angiogenesis in zebrafish. The study reveals a haemodynamic-force-driven and myosin-II-dependent cellular mechanism (termed inverse membrane blebbing) as the basis for lumen expansion in unicellular and multicellular angiogenic sprouts. PMID:27027487

  4. Blood, blebs and lumen expansion.

    PubMed

    Reichman-Fried, Michal; Raz, Erez

    2016-04-01

    A powerful combination of cell labelling, genetic tools and rapid imaging techniques in vivo has now led to a high-resolution description of lumen formation during angiogenesis in zebrafish. The study reveals a haemodynamic-force-driven and myosin-II-dependent cellular mechanism (termed inverse membrane blebbing) as the basis for lumen expansion in unicellular and multicellular angiogenic sprouts.

  5. Prediction of particulate loading in exhaust from fabric filter baghouses with one or more failed bags

    SciTech Connect

    Wenjun Qin; Manuel Dekermenjian; Richard J. Martin

    2006-08-15

    Loss of filtration efficiency in a fabric filter baghouse is typically caused by bag failure, in one form or another. The degree of such failure can be as minor as a pinhole leak or as major as a fully involved baghouse fire. In some cases, local air pollution regulations or federal hazardous waste laws may require estimation of the total quantity of particulate matter released to the environment as a result of such failures. In this paper, a technique is presented for computing the dust loading in the baghouse exhaust when one or more bags have failed. The algorithm developed is shown to be an improvement over a previously published result, which requires empirical knowledge of the variation in baghouse pressure differential with bag failures. An example calculation is presented for a baghouse equipped with 200 bags. The prediction shows that a small percentage of failed bags can cause a relatively large proportion of the gas flow to bypass the active bags, which, in turn, leads to high outlet dust loading and low overall collection efficiency from the baghouse. 10 refs., 5 figs., 3 tabs.

  6. New novel method for solving ASML alignment fail (model error) in color filter process

    NASA Astrophysics Data System (ADS)

    Weng, Fu-Tien; Hsiung, Chung-Sheng; Hsiao, Yu-Kung; Pang, Sheng-Liang; Lu, Kuo-Liang

    2001-04-01

    For better resolution and throughput concern on color filter process, we use ASML5500/100 for color filter production instead of 1X CANON, but it often suffered alignment fail (error code: model error) at the green layer. Some items have been studied: (1) pattern close to ASML PM mark; (2) level sensor issue (level sensor contamination, plate tilt, level lens contamination); (3) different process sequence; (4) open the clear-out window at passivation layer to reduce interference effect. All of these items are proved no obviously influence to induce model error. By checking the spectrum of the green photo-resist, we found that it is low transmittance at 633 nm1 (the wavelength that the ASML alignment laser uses). Raising the transmittance by reducing the thickness of green resist is proved useful to eliminate the occurrence of model error. On the other hand, the ATHENATM provided by ASML which use red and green lights for alignment will get rid of the alignment failure.

  7. Intracellular Pressure Dynamics in Blebbing Cells.

    PubMed

    Strychalski, Wanda; Guy, Robert D

    2016-03-01

    Blebs are pressure-driven protrusions that play an important role in cell migration, particularly in three-dimensional environments. A bleb is initiated when the cytoskeleton detaches from the cell membrane, resulting in the pressure-driven flow of cytosol toward the area of detachment and local expansion of the cell membrane. Recent experiments involving blebbing cells have led to conflicting hypotheses regarding the timescale of intracellular pressure propagation. The interpretation of one set of experiments supports a poroelastic model of the cytoplasm that leads to slow pressure equilibration when compared to the timescale of bleb expansion. A different study concludes that pressure equilibrates faster than the timescale of bleb expansion. To address this discrepancy, a dynamic computational model of the cell was developed that includes mechanics of and the interactions among the cytoplasm, the actin cortex, the cell membrane, and the cytoskeleton. The model results quantify the relationship among cytoplasmic rheology, pressure, and bleb expansion dynamics, and provide a more detailed picture of intracellular pressure dynamics. This study shows the elastic response of the cytoplasm relieves pressure and limits bleb size, and that both permeability and elasticity of the cytoplasm determine bleb expansion time. Our model with a poroelastic cytoplasm shows that pressure disturbances from bleb initiation propagate faster than the timescale of bleb expansion and that pressure equilibrates slower than the timescale of bleb expansion. The multiple timescales in intracellular pressure dynamics explain the apparent discrepancy in the interpretation of experimental results. PMID:26958893

  8. Bleb-driven chemotaxis of Dictyostelium cells

    PubMed Central

    Zatulovskiy, Evgeny; Tyson, Richard; Bretschneider, Till

    2014-01-01

    Blebs and F-actin–driven pseudopods are alternative ways of extending the leading edge of migrating cells. We show that Dictyostelium cells switch from using predominantly pseudopods to blebs when migrating under agarose overlays of increasing stiffness. Blebs expand faster than pseudopods leaving behind F-actin scars, but are less persistent. Blebbing cells are strongly chemotactic to cyclic-AMP, producing nearly all of their blebs up-gradient. When cells re-orientate to a needle releasing cyclic-AMP, they stereotypically produce first microspikes, then blebs and pseudopods only later. Genetically, blebbing requires myosin-II and increases when actin polymerization or cortical function is impaired. Cyclic-AMP induces transient blebbing independently of much of the known chemotactic signal transduction machinery, but involving PI3-kinase and downstream PH domain proteins, CRAC and PhdA. Impairment of this PI3-kinase pathway results in slow movement under agarose and cells that produce few blebs, though actin polymerization appears unaffected. We propose that mechanical resistance induces bleb-driven movement in Dictyostelium, which is chemotactic and controlled through PI3-kinase. PMID:24616222

  9. Blue rubber bleb nevus syndrome

    PubMed Central

    Carr, Michele M.; Jamieson, Christopher G.; Lal, Geeta

    1996-01-01

    Blue rubber bleb nevus syndrome, an uncommon condition, is manifested by gastrointestinal and skin hemangiomas and gastrointestinal hemorrhage causing anemia. The authors report a unique case of the syndrome in association with a congenital cardiac malformation. A 26-year-old woman presented with iron-deficiency anemia after the birth of her first child. She had a history of skin and gastrointestinal hemangiomas and tetralogy of Fallot. Endoscopy revealed multiple new intestinal hemangiomas, which were removed through enterotomies with resolution of the anemia. Iron therapy was prescribed, and her condition was stable at follow-up 5 years later. PMID:8599795

  10. Cell Blebbing in Confined Microfluidic Environments

    PubMed Central

    Ibo, Markela; Srivastava, Vasudha; Robinson, Douglas N.; Gagnon, Zachary R.

    2016-01-01

    Migrating cells can extend their leading edge by forming myosin-driven blebs and F-actin-driven pseudopods. When coerced to migrate in resistive environments, Dictyostelium cells switch from using predominately pseudopods to blebs. Bleb formation has been shown to be chemotactic and can be influenced by the direction of the chemotactic gradient. In this study, we determine the blebbing responses of developed cells of Dictyostelium discoideum to cAMP gradients of varying steepness produced in microfluidic channels with different confining heights, ranging between 1.7 μm and 3.8 μm. We show that microfluidic confinement height, gradient steepness, buffer osmolarity and Myosin II activity are important factors in determining whether cells migrate with blebs or with pseudopods. Dictyostelium cells were observed migrating within the confines of microfluidic gradient channels. When the cAMP gradient steepness is increased from 0.7 nM/μm to 20 nM/μm, cells switch from moving with a mixture of blebs and pseudopods to moving only using blebs when chemotaxing in channels with confinement heights less than 2.4 μm. Furthermore, the size of the blebs increases with gradient steepness and correlates with increases in myosin-II localization at the cell cortex. Reduction of intracellular pressure by high osmolarity buffer or inhibition of myosin-II by blebbistatin leads to a decrease in bleb formation and bleb size. Together, our data reveal that the protrusion type formed by migrating cells can be influenced by the channel height and the steepness of the cAMP gradient, and suggests that a combination of confinement-induced myosin-II localization and cAMP-regulated cortical contraction leads to increased intracellular fluid pressure and bleb formation. PMID:27706201

  11. Paclitaxel-Releasing Thin Biodegradable Film for Prevention of Bleb Avascularity Without Compromising Filtration in Rabbits

    PubMed Central

    Okuda, Tetsuhiko; Higashide, Tomomi; Sakurai, Mayumi; Fukuhira, Yukako; Kaneko, Hiroaki; Shimomura, Masatsugu; Sugiyama, Kazuhisa

    2015-01-01

    Purpose: A honeycomb-patterned film (HPF) prevents bleb scarring and mitomycin C (MMC)-related bleb avascularity in a rabbit model of filtration surgery. In this study, we examined whether a HPF-releasing paclitaxel (PTX) can prevent bleb avascularity without compromising filtration. Methods: Filtration surgery was performed in one eye of rabbits. A 14-μm thick HPF made from poly(L-lactide-co-ε-caprolactone) was placed subconjunctivally over the filtration site with the honeycomb surface turned toward the subconjunctival Tenon tissue. The rabbits were divided into four groups (n = 5 each): 1, HPF with no drug; 2, HPF + PTX 50 μg; 3, HPF + 5 μg; 4, HPF + 0.5 μg. Intraocular pressure (IOP) measurements and bleb evaluations using ultrasound biomicroscopy were performed periodically for 4 weeks followed by histological examination. A longer follow-up study (12 weeks) was performed for group 4 (experiment 2; n = 8). Results: Among all groups at the 4-week follow up, two blebs failed in group 1. The postoperative IOP decrease was significantly greater in PTX-treated eyes than in group 1. The bleb avascular area persisted for 4 weeks in groups 2 and 3. However, no avascular area was observed in groups 1 and 4 at 4 weeks postoperatively. Histology showed minimal fibrosis at the filtration site in all the PTX groups. In experiment 2, some blebs became flatter starting at 10 weeks after surgery. Conclusions: PTX released from HPF promoted bleb survival and IOP decrease. The lowest dose of PTX (0.5 μg) was effective at preventing bleb avascularity without compromising filtration. PMID:26101723

  12. A computational model of bleb formation

    PubMed Central

    Strychalski, Wanda; Guy, Robert D.

    2013-01-01

    Blebbing occurs when the cytoskeleton detaches from the cell membrane, resulting in the pressure-driven flow of cytosol towards the area of detachment and the local expansion of the cell membrane. Recent interest has focused on cells that use blebbing for migrating through 3D fibrous matrices. In particular, metastatic cancer cells have been shown to use blebs for motility. A dynamic computational model of the cell is presented that includes mechanics of and the interactions between the intracellular fluid, the actin cortex and the cell membrane. The computational model is used to explore the relative roles in bleb formation time of cytoplasmic viscosity and drag between the cortex and the cytosol. A regime of values for the drag coefficient and cytoplasmic viscosity values that match bleb formation timescales is presented. The model results are then used to predict the Darcy permeability and the volume fraction of the cortex. PMID:22294562

  13. Fibrin glue coating of the surgical surfaces may facilitate formation of a successful bleb in trabeculectomy surgery.

    PubMed

    Sakarya, Yasar; Sakarya, Rabia; Kara, Selcuk; Soylu, Tulay

    2011-08-01

    Trabeculectomy is commonly conducted when medical therapy fails to control intraocular pressure (IOP). The success of trabeculectomy for the treatment of glaucoma depends on the wound-healing response at the subconjunctival filtering bleb site. Postoperative scar formation is a serious problem in this surgery. Current strategies to counteract scarring include local antimetabolite treatment, which is associated with severe side effects, limiting its application. Therefore, additional means to safely modulate wound healing are desirable. In ophthalmic surgery, fibrin glue is used mainly for sealing and hemostatics purpose. Fibrin glue coating of tenon face of conjunctiva, scleral surface, reverse face of scleral flap and scleral bed with insoluble fibrin glue can halt both ooze bleeding and vascular leakage. By retarding the first step of wound healing, less postoperative inflammation may occur. Additionally aqueous humor flows through a fibrin glue coated interface. Therefore, we hypothesize that fibrin glue coating of the surgical surfaces in trabeculectomy surgery may yield less subconjunctival fibrosis and more successful bleb. To the best of our knowledge, no basic research has yet been performed regarding fibrin glue coating for halting the vascular leakage and easing the aqueous drainage into subconjunctival space in glaucoma surgery.

  14. Inferior Vena Cava Filter Placement during Pregnancy: An Adjuvant Option When Medical Therapy Fails

    PubMed Central

    Serrano, Fátima; Torres, Rita; Borges, Augusta

    2013-01-01

    The authors present a case of a 27-year-old multiparous woman, with multiple thrombophilia, whose pregnancy was complicated with deep venous thrombosis requiring placement of a vena cava filter. At 15th week of gestation, following an acute deep venous thrombosis of the right inferior limb, anticoagulant therapy with low-molecular-weight heparin (LMWH) was instituted without improvement in her clinical status. Subsequently, at 18 weeks of pregnancy, LMWH was switched to warfarin. At 30th week of gestation, the maintenance of high thrombotic risk was the premise for placement of an inferior vena cava filter for prophylaxis of pulmonary embolism during childbirth and postpartum. There were no complications and a vaginal delivery was accomplished at 37 weeks of gestation. Venal placement of inferior vena cava filters is an attractive option as prophylaxis for pulmonary embolism during pregnancy. PMID:23781361

  15. Lidocaine induces ROCK-dependent membrane blebbing and subsequent cell death in rabbit articular chondrocytes.

    PubMed

    Maeda, Tsutomu; Toyoda, Futoshi; Imai, Shinji; Tanigawa, Hitoshi; Kumagai, Kousuke; Matsuura, Hiroshi; Matsusue, Yoshitaka

    2016-05-01

    Local anesthetics are administered intraarticularly for pain control in orthopedic clinics and surgeries. Although previous studies have shown that local anesthetics can be toxic to chondrocytes, the underlying cellular mechanisms remain unclear. The present study investigates acute cellular responses associated with lidocaine-induced toxicity to articular chondrocytes. Rabbit articular chondrocytes were exposed to lidocaine and their morphological changes were monitored with live cell microscopy. The viability of chondrocytes was evaluated using a fluorescence based LIVE/DEAD assay. Acute treatment of chondrocytes with lidocaine (3-30 mM) induced spherical protrusions on the cell surface (so called "membrane blebbing") in a time- and concentration-dependent manner. The concentration-response relationship for the lidocaine effect was shifted leftward by elevating extracellular pH, as expected for the non-ionized lidocaine being involved in the bleb formation. ROCK (Rho-kinase) inhibitors Y-27632 and fasudil completely prevented the lidocaine-induced membrane blebbing, suggesting that ROCK activation is required for bleb formation. Caspase-3 levels were unchanged by 10 mM lidocaine (p = 0.325) and a caspase inhibitor z-VAD-fmk did not affect the lidocaine-induced blebbing (p = 0.964). GTP-RhoA levels were significantly increased (p < 0.001), but Rho inhibitor-1 failed to suppress the membrane blebbing (p = 0.875). Lidocaine (30 mM) reduced the cell viability of isolated chondrocytes (p < 0.001) and in situ chondrocytes (p < 0.001). The chondrotoxicity was attenuated by pretreatment of cells with ROCK inhibitors or a myosin-II inhibitor blebbistatin (p < 0.001). These findings suggest that lidocaine induces ROCK-dependent membrane blebbing and thereby produces a cytotoxic effect on chondrocytes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:754-762, 2016.

  16. Actin polymerization and intracellular solvent flow in cell surface blebbing

    PubMed Central

    1995-01-01

    The cortical actin gel of eukaryotic cells is postulated to control cell surface activity. One type of protrusion that may offer clues to this regulation are the spherical aneurysms of the surface membrane known as blebs. Blebs occur normally in cells during spreading and alternate with other protrusions, such as ruffles, suggesting similar protrusive machinery is involved. We recently reported that human melanoma cell lines deficient in the actin filament cross-linking protein, ABP-280, show prolonged blebbing, thus allowing close study of blebs and their dynamics. Blebs expand at different rates of volume increase that directly predict the final size achieved by each bleb. These rates decrease as the F-actin concentration of the cells increase over time after plating on a surface, but do so at lower concentrations in ABP-280 expressing cells. Fluorescently labeled actin and phalloidin injections of blebbing cells indicate that a polymerized actin structure is not present initially, but appears later and is responsible for stopping further bleb expansion. Therefore, it is postulated that blebs occur when the fluid-driven expansion of the cell membrane is sufficiently rapid to initially outpace the local rate of actin polymerization. In this model, the rate of intracellular solvent flow driving this expansion decreases as cortical gelation is achieved, whether by factors such as ABP-280, or by concentrated actin polymers alone, thereby leading to decreased size and occurrence of blebs. Since the forces driving bleb extension would always be present in a cell, this process may influence other cell protrusions as well. PMID:7790356

  17. Membrane Blebbing Is Required for Mesenchymal Precursor Migration

    PubMed Central

    de Lucas, Beatriz; Bernal, Aurora; M. Pérez, Laura; San Martín, Nuria; Gálvez, Beatriz G.

    2016-01-01

    Mesenchymal precursors (MPs) present some advantageous features, such as differentiation and migration, which make them promising candidates for cell therapy. A better understanding of MP migration characteristics would aid the development of cell delivery protocols. Traditionally, cell migration is thought to occur only through the formation of lamellipodia. More recently, contractility-driven bleb formation has emerged as an alternative mechanism of motility. Here we report that MPs derived from different tissues present spontaneously dynamic cytoplasmic projections in sub-confluent culture, which appear as a combination of lamellipodia with blebs in the leading edge. Upon initial seeding, however, only bleb structures could be observed. Immunofluorescence revealed the presence of pERM, RhoA and F-actin during the blebbing process. Results from migration assays in the presence of blebbistatin, a myosin II inhibitor, showed that bleb formation correlated with migratory capacity, suggesting a functional role for blebs in migration. Bleb formation might be a useful mechanism to improve cell migration in cellular therapy protocols. PMID:26930466

  18. An atypical presentation of blue rubber bleb nevus syndrome

    PubMed Central

    Lizardo-Sanchez, Luis

    2016-01-01

    A 69-year-old white man presented with several episodes of hematochezia. Colonoscopy demonstrated multiple colonic blebs localized mainly in the distal transverse colon. Esophagogastroduodenoscopy, capsule endoscopy, and computed tomography of the abdomen did not reveal any abnormalities. The patient required several blood transfusions and eventually required a subtotal colectomy with ileosigmoid anastomosis for definitive bleeding control. Pathology was remarkable for multifocal vascular ectasia, consistent with the diagnosis of blue rubber bleb nevus syndrome. PMID:27365887

  19. Primary spontaneous pneumothorax due to high bleb burden.

    PubMed

    Segraves, Justin M; Dulohery, Megan M

    2016-01-01

    Primary spontaneous pneumothorax (PSP) occurs most frequently in young, tall, lean, male smokers without any known underlying lung disease. It is an important diagnosis to make promptly in order to prevent progression to obstructive shock. We present a case report of a young, male, former-smoker and polysubstance abuser with no prior lung history that developed acute dyspnea at rest and was found to have a large right pneumothorax on chest x-ray. A pig-tail catheter was utilized, but his course was complicated by a recurrent tension pneumothorax. Chest computed tomography (CT) revealed a significant bleb burden and the patient underwent a lung wedge resection with mechanical pleurodesis. What made our case unique were the chest x-rays revealing blebs that could have predicted the patient's recurrent pneumothorax as well as the multiple potential risk factors for developing blebs and a pneumothorax. All patients with recurrent PSPs and those with higher risk initial PSPs (e.g. blebs) should undergo preventive therapy with pleurodesis. We hope that clinicians can benefit from utilizing these representative chest x-ray images showing blebs. PMID:27642566

  20. Microtubule-Mediated Inositol Lipid Signaling Plays Critical Roles in Regulation of Blebbing

    PubMed Central

    Sugiyama, Tatsuroh; Pramanik, Md. Kamruzzaman; Yumura, Shigehiko

    2015-01-01

    Cells migrate by extending pseudopods such as lamellipodia and blebs. Although the signals leading to lamellipodia extension have been extensively investigated, those for bleb extension remain unclear. Here, we investigated signals for blebbing in Dictyostelium cells using a newly developed assay to induce blebbing. When cells were cut into two pieces with a microneedle, the anucleate fragments vigorously extended blebs. This assay enabled us to induce blebbing reproducibly, and analyses of knockout mutants and specific inhibitors identified candidate molecules that regulate blebbing. Blebs were also induced in anucleate fragments of leukocytes, indicating that this assay is generally applicable to animal cells. After cutting, microtubules in the anucleate fragments promptly depolymerized, followed by the extension of blebs. Furthermore, when intact cells were treated with a microtubule inhibitor, they frequently extended blebs. The depolymerization of microtubules induced the delocalization of inositol lipid phosphatidylinositol 3,4,5-trisphosphate from the cell membrane. PI3 kinase-null cells frequently extended blebs, whereas PTEN-null cells extended fewer blebs. From these observations, we propose a model in which microtubules play a critical role in bleb regulation via inositol lipid metabolism. PMID:26317626

  1. An Elastic Model of Blebbing in Nuclear Lamin Meshworks

    NASA Astrophysics Data System (ADS)

    Funkhouser, Chloe; Sknepnek, Rastko; Shimi, Takeshi; Goldman, Anne; Goldman, Robert; Olvera de La Cruz, Monica

    2013-03-01

    A two-component continuum elastic model is introduced to analyze a nuclear lamin meshwork, a structural element of the lamina of the nuclear envelope. The main component of the lamina is a meshwork of lamin protein filaments providing mechanical support to the nucleus and also playing a role in gene expression. Abnormalities in nuclear shape are associated with a variety of pathologies, including some forms of cancer and Hutchinson-Gilford progeria syndrome, and are often characterized by protruding structures termed nuclear blebs. Nuclear blebs are rich in A-type lamins and may be related to pathological gene expression. We apply the two-dimensional elastic shell model to determine which characteristics of the meshwork could be responsible for blebbing, including heterogeneities in the meshwork thickness and mesh size. We find that if one component of the lamin meshwork, rich in A-type lamins, has a tendency to form a larger mesh size than that rich in B-type lamins, this is sufficient to cause segregation of the lamin components and also to form blebs rich in A-type lamins. The model produces structures with comparable morphologies and mesh size distributions as the lamin meshworks of real, pathological nuclei. Funded by US DoE Award DEFG02-08ER46539 and by the DDR&E and AFOSR under Award FA9550-10-1-0167; simulations performed on NU Quest cluster

  2. The ADP-ribosylation domain of Pseudomonas aeruginosa ExoS is required for membrane bleb niche formation and bacterial survival within epithelial cells.

    PubMed

    Angus, Annette A; Evans, David J; Barbieri, Joseph T; Fleiszig, Suzanne M J

    2010-11-01

    Pseudomonas aeruginosa can establish a niche within the plasma membrane of epithelial cells (bleb niches) within which bacteria can survive, replicate, and swim at speeds detectable by real-time phase-contrast imaging. This novel virulence strategy is dependent on the bacterial type three secretion system (T3SS), since mutants lacking the T3SS needle or known T3SS effectors localize to perinuclear vacuoles and fail to replicate. Here, we determined which of the three effectors (ExoS, ExoT, or ExoY) were required for bleb niche formation and intracellular replication. PAO1 strains with mutations in exoS, exoT, exoY, or combinations thereof were compared to wild-type and complemented strains. P. aeruginosa exoS mutants, but not exoT or exoY mutants, lost the capacity for bleb niche formation and intracellular replication. Complementation with exoS rescued both phenotypes, either in the background of an exoS mutant or in a mutant lacking all three known effectors. Complementation with activity domain mutants of exoS revealed that the ADP-ribosyltransferase (ADP-r) activity of ExoS, but not the Rho-GAP activity nor the membrane localization domain (MLD) of ExoS, was required to elicit this phenotype. Membrane bleb niches that contained P. aeruginosa also bound annexin V-enhanced green fluorescent protein (EGFP), a marker of early apoptosis. These data show that P. aeruginosa bleb niches and intracellular survival involve ExoS ADP-r activity and implicate a connection between bleb niche formation and the known role(s) of ExoS-mediated apoptosis and/or Rab GTPase inactivation.

  3. Assessment of Filtration Bleb and Endplate Positioning Using Magnetic Resonance Imaging in Eyes Implanted with Long-Tube Glaucoma Drainage Devices

    PubMed Central

    Sano, Ichiya; Tanito, Masaki; Uchida, Koji; Katsube, Takashi; Kitagaki, Hajime; Ohira, Akihiro

    2015-01-01

    Background To evaluate ocular fluid filtration and endplate positioning in glaucomatous eyes with long-tube glaucoma drainage devices (GDDs) using magnetic resonance imaging (MRI) and the effects of various factors on postoperative intraocular pressure (IOP). Methods This observational case series included 27 consecutive glaucomatous eyes (18 men, 7 women; mean age ± standard error, 63.0±2.0 years) who underwent GDD implantation (n = 8 Ahmed Glaucoma Valves [AGV] and n = 19 Baerveldt Glaucoma Implants [BGI]). Tubes were inserted into the pars plana in 23 eyes and anterior chamber in 4 eyes. Six months postoperatively, high-resolution orbital images were obtained using 3-Tesla MRI with head-array coils, and the filtering bleb volume, bleb height, and distances between the anterior endplate edge and corneal center or limbus or between the endplate and orbital wall were measured. Results In MR images obtained by three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences, the shunt endplate was identified as low-intensity signal, and the filtering bleb was identified as high-intensity signals above and below the endplate in all eyes. The 6-month-postoperative IOP level was correlated negatively with bleb volume (r = -0.4510, P = 0.0182) and bleb height (r = -0.3954, P = 0.0412). The postoperative IOP was significantly (P = 0.0026) lower in BGI-implanted eyes (12.2±0.7 mmHg) than AGV-implanted eyes (16.7±1.2 mmHg); bleb volume was significantly (P = 0.0093) larger in BGI-implanted eyes (478.8±84.2 mm3) than AGV-implanted eyes (161.1±52.3 mm3). Other parameters did not differ. Conclusions The presence of intraorbital/periocular accumulation of ocular fluid affects postoperative IOP levels in eyes implanted with long-tube GDDs. Larger filtering blebs after BGI than AGI implantations explain lower postoperative IOP levels achieved with BGI than AGV. The findings will contribute to better understanding of IOP reducing mechanism of long

  4. Directional Bleb Formation in Spherical Cells under Temperature Gradient

    PubMed Central

    Oyama, Kotaro; Arai, Tomomi; Isaka, Akira; Sekiguchi, Taku; Itoh, Hideki; Seto, Yusuke; Miyazaki, Makito; Itabashi, Takeshi; Ohki, Takashi; Suzuki, Madoka; Ishiwata, Shin'ichi

    2015-01-01

    Living cells sense absolute temperature and temporal changes in temperature using biological thermosensors such as ion channels. Here, we reveal, to our knowledge, a novel mechanism of sensing spatial temperature gradients within single cells. Spherical mitotic cells form directional membrane extensions (polar blebs) under sharp temperature gradients (≥∼0.065°C μm−1; 1.3°C temperature difference within a cell), which are created by local heating with a focused 1455-nm laser beam under an optical microscope. On the other hand, multiple nondirectional blebs are formed under gradual temperature gradients or uniform heating. During heating, the distribution of actomyosin complexes becomes inhomogeneous due to a break in the symmetry of its contractile force, highlighting the role of the actomyosin complex as a sensor of local temperature gradients. PMID:26200871

  5. Membrane shrinkage and cortex remodelling are predicted to work in harmony to retract blebs.

    PubMed

    Woolley, Thomas E; Gaffney, Eamonn A; Goriely, Alain

    2015-07-01

    Numerous cell types undergo an oscillatory form of dynamics known as blebbing, whereby pressure-driven spherical protrusions of membrane (known as blebs) expand and contract over the cell's surface. Depending on the cell line, blebs play important roles in many different phenomena including mitosis and locomotion. The expansion phase of cellular blebbing has been mathematically modelled in detail. However, the active processes occurring during the retraction phase are not so well characterized. It is thought that blebs retract because a cortex reforms inside, and adheres to, the bleb membrane. This cortex is retracted into the cell and the attached bleb membrane follows. Using a computational model of a cell's membrane, cortex and interconnecting adhesions, we demonstrate that cortex retraction alone cannot account for bleb retraction and suggest that the mechanism works in tandem with membrane shrinking. Further, an emergent hysteresis loop is observed in the intracellular pressure, which suggests a potential mechanism through which a secondary bleb can be initiated as a primary bleb contracts. PMID:26587278

  6. Membrane shrinkage and cortex remodelling are predicted to work in harmony to retract blebs

    PubMed Central

    Woolley, Thomas E.; Gaffney, Eamonn A.; Goriely, Alain

    2015-01-01

    Numerous cell types undergo an oscillatory form of dynamics known as blebbing, whereby pressure-driven spherical protrusions of membrane (known as blebs) expand and contract over the cell's surface. Depending on the cell line, blebs play important roles in many different phenomena including mitosis and locomotion. The expansion phase of cellular blebbing has been mathematically modelled in detail. However, the active processes occurring during the retraction phase are not so well characterized. It is thought that blebs retract because a cortex reforms inside, and adheres to, the bleb membrane. This cortex is retracted into the cell and the attached bleb membrane follows. Using a computational model of a cell's membrane, cortex and interconnecting adhesions, we demonstrate that cortex retraction alone cannot account for bleb retraction and suggest that the mechanism works in tandem with membrane shrinking. Further, an emergent hysteresis loop is observed in the intracellular pressure, which suggests a potential mechanism through which a secondary bleb can be initiated as a primary bleb contracts. PMID:26587278

  7. A RhoA and Rnd3 cycle regulates actin reassembly during membrane blebbing.

    PubMed

    Aoki, Kana; Maeda, Fumiyo; Nagasako, Tomoya; Mochizuki, Yuki; Uchida, Seiichi; Ikenouchi, Junichi

    2016-03-29

    The actin cytoskeleton usually lies beneath the plasma membrane. When the membrane-associated actin cytoskeleton is transiently disrupted or the intracellular pressure is increased, the plasma membrane detaches from the cortex and protrudes. Such protruded membrane regions are called blebs. However, the molecular mechanisms underlying membrane blebbing are poorly understood. This study revealed that epidermal growth factor receptor kinase substrate 8 (Eps8) and ezrin are important regulators of rapid actin reassembly for the initiation and retraction of protruded blebs. Live-cell imaging of membrane blebbing revealed that local reassembly of actin filaments occurred at Eps8- and activated ezrin-positive foci of membrane blebs. Furthermore, we found that a RhoA-ROCK-Rnd3 feedback loop determined the local reassembly sites of the actin cortex during membrane blebbing. PMID:26976596

  8. A RhoA and Rnd3 cycle regulates actin reassembly during membrane blebbing.

    PubMed

    Aoki, Kana; Maeda, Fumiyo; Nagasako, Tomoya; Mochizuki, Yuki; Uchida, Seiichi; Ikenouchi, Junichi

    2016-03-29

    The actin cytoskeleton usually lies beneath the plasma membrane. When the membrane-associated actin cytoskeleton is transiently disrupted or the intracellular pressure is increased, the plasma membrane detaches from the cortex and protrudes. Such protruded membrane regions are called blebs. However, the molecular mechanisms underlying membrane blebbing are poorly understood. This study revealed that epidermal growth factor receptor kinase substrate 8 (Eps8) and ezrin are important regulators of rapid actin reassembly for the initiation and retraction of protruded blebs. Live-cell imaging of membrane blebbing revealed that local reassembly of actin filaments occurred at Eps8- and activated ezrin-positive foci of membrane blebs. Furthermore, we found that a RhoA-ROCK-Rnd3 feedback loop determined the local reassembly sites of the actin cortex during membrane blebbing.

  9. [Blue rubber bleb nevus syndrome: A case report].

    PubMed

    López-Ugalde, M V; Cazares-Méndez, M J; Vivar-Aquino, L D; Cadena-León, J F; Cervantes-Bustamante, R; Zárate-Mondragón, F; Montijo-Barrios, E; Ramírez-Mayans, J

    2012-01-01

    Blue Rubber Bleb Nevus Syndrome (BRBS) is a rare disease, characterized by multiple vascular malformations in the skin and gastrointestinal tract. Other organs can also be affected, presenting different clinical manifestations such as arthralgia, epistaxis, hemoptysis, hematuria, hemothorax, mild thrombocytopenia, consumptive coagulopathy, and bone deformities, among others. We present a case of BRBS in a nine-year-old boy with the characteristic clinical manifestations of punctated purplish-blue skin lesions that vary in size and gastrointestinal vascular malformations with upper digestive tract bleeding.

  10. Shape remodeling and blebbing of active cytoskeletal vesicles.

    PubMed

    Loiseau, Etienne; Schneider, Jochen A M; Keber, Felix C; Pelzl, Carina; Massiera, Gladys; Salbreux, Guillaume; Bausch, Andreas R

    2016-04-01

    Morphological transformations of living cells, such as shape adaptation to external stimuli, blebbing, invagination, or tethering, result from an intricate interplay between the plasma membrane and its underlying cytoskeleton, where molecular motors generate forces. Cellular complexity defies a clear identification of the competing processes that lead to such a rich phenomenology. In a synthetic biology approach, designing a cell-like model assembled from a minimal set of purified building blocks would allow the control of all relevant parameters. We reconstruct actomyosin vesicles in which the coupling of the cytoskeleton to the membrane, the topology of the cytoskeletal network, and the contractile activity can all be precisely controlled and tuned. We demonstrate that tension generation of an encapsulated active actomyosin network suffices for global shape transformation of cell-sized lipid vesicles, which are reminiscent of morphological adaptations in living cells. The observed polymorphism of our cell-like model, such as blebbing, tether extrusion, or faceted shapes, can be qualitatively explained by the protein concentration dependencies and a force balance, taking into account the membrane tension, the density of anchoring points between the membrane and the actin network, and the forces exerted by molecular motors in the actin network. The identification of the physical mechanisms for shape transformations of active cytoskeletal vesicles sets a conceptual and quantitative benchmark for the further exploration of the adaptation mechanisms of cells. PMID:27152328

  11. Shape remodeling and blebbing of active cytoskeletal vesicles

    PubMed Central

    Loiseau, Etienne; Schneider, Jochen A. M.; Keber, Felix C.; Pelzl, Carina; Massiera, Gladys; Salbreux, Guillaume; Bausch, Andreas R.

    2016-01-01

    Morphological transformations of living cells, such as shape adaptation to external stimuli, blebbing, invagination, or tethering, result from an intricate interplay between the plasma membrane and its underlying cytoskeleton, where molecular motors generate forces. Cellular complexity defies a clear identification of the competing processes that lead to such a rich phenomenology. In a synthetic biology approach, designing a cell-like model assembled from a minimal set of purified building blocks would allow the control of all relevant parameters. We reconstruct actomyosin vesicles in which the coupling of the cytoskeleton to the membrane, the topology of the cytoskeletal network, and the contractile activity can all be precisely controlled and tuned. We demonstrate that tension generation of an encapsulated active actomyosin network suffices for global shape transformation of cell-sized lipid vesicles, which are reminiscent of morphological adaptations in living cells. The observed polymorphism of our cell-like model, such as blebbing, tether extrusion, or faceted shapes, can be qualitatively explained by the protein concentration dependencies and a force balance, taking into account the membrane tension, the density of anchoring points between the membrane and the actin network, and the forces exerted by molecular motors in the actin network. The identification of the physical mechanisms for shape transformations of active cytoskeletal vesicles sets a conceptual and quantitative benchmark for the further exploration of the adaptation mechanisms of cells. PMID:27152328

  12. Membrane blebbing as a recovery manoeuvre in site-specific sonoporation mediated by targeted microbubbles

    PubMed Central

    Leow, Ruen Shan; Wan, Jennifer M. F.; Yu, Alfred C. H.

    2015-01-01

    Site-specific perforation of the plasma membrane can be achieved through ultrasound-triggered cavitation of a single microbubble positioned adjacent to the cell. However, for this perforation approach (sonoporation), the recovery manoeuvres invoked by the cell are unknown. Here, we report new findings on how membrane blebbing can be a recovery manoeuvre that may take place in sonoporation episodes whose pores are of micrometres in diameter. Each sonoporation site was created using a protocol involving single-shot ultrasound exposure (frequency: 1 MHz; pulse length: 30 cycles; peak negative pressure: 0.45 MPa) which triggered inertial cavitation of a single targeted microbubble (diameter: 1–5 µm). Over this process, live confocal microscopy was conducted in situ to monitor membrane dynamics, model drug uptake kinetics and cytoplasmic calcium ion (Ca2+) distribution. Results show that blebbing would occur at a recovering sonoporation site after its resealing, and it may emerge elsewhere along the membrane periphery. The bleb size was correlated with the pre-exposure microbubble diameter, and 99% of blebbing cases at sonoporation sites were inflicted by microbubbles larger than 1.5 µm diameter (analysed over 124 sonoporation episodes). Blebs were not observed at irreversible sonoporation sites or when sonoporation site repair was inhibited via extracellular Ca2+ chelation. Functionally, the bleb volume was found to serve as a buffer compartment to accommodate the cytoplasmic Ca2+ excess brought about by Ca2+ influx during sonoporation. These findings suggest that membrane blebbing would help sonoporated cells restore homeostasis. PMID:25694544

  13. SH4-domain-induced plasma membrane dynamization promotes bleb-associated cell motility.

    PubMed

    Tournaviti, Stella; Hannemann, Sebastian; Terjung, Stefan; Kitzing, Thomas M; Stegmayer, Carolin; Ritzerfeld, Julia; Walther, Paul; Grosse, Robert; Nickel, Walter; Fackler, Oliver T

    2007-11-01

    SH4 domains provide bipartite membrane-targeting signals for oncogenic Src family kinases. Here we report the induction of non-apoptotic plasma membrane (PM) blebbing as a novel and conserved activity of SH4 domains derived from the prototypic Src kinases Src, Fyn, Yes and Lck as well as the HASPB protein of Leishmania parasites. SH4-domain-induced blebbing is highly dynamic, with bleb formation and collapse displaying distinct kinetics. These reorganizations of the PM are controlled by Rho but not Rac or Cdc42 GTPase signalling pathways. SH4-induced membrane blebbing requires the membrane association of the SH4 domain, is regulated by the activities of Rock kinase and myosin II ATPase, and depends on the integrity of F-actin as well as microtubules. Endogenous Src kinase activity is crucial for PM blebbing in SH4-domain-expressing cells, active Src and Rock kinases are enriched in SH4-domain-induced PM blebs, and PM blebbing correlates with enhanced cell invasion in 3D matrices. These results establish a novel link between SH4 domains, Src activity and Rho signalling, and implicate SH4-domain-mediated PM dynamization as a mechanism that influences invasiveness of cells transformed by SH4-domain-containing oncoproteins. PMID:17959630

  14. Treatment with sodium hyaluronate eye drops in a patient who had early-onset bleb leakage after trabeculectomy with mitomycin C

    PubMed Central

    Sagara, Hideto; Sekiryu, Tetsuju; Noji, Hiroki; Ogasawara, Masashi; Imaizumi, Kimihiro; Yago, Keiko

    2015-01-01

    We present the case of a 47-year-old man who had bilateral proliferative diabetic retinopathy and neovascular glaucoma. Schirmer I test revealed tear secretions of 5 mm and 3 mm in the right and left eyes, respectively. Tear breakup times in the right and left eyes were 7 and 8 seconds, respectively. The ocular surface staining in both eyes was scored as Grade 1 as per the Oxford scheme. Retinal photocoagulation was performed for correction of the proliferative diabetic retinopathy and rubeosis iridis, which resolved with treatment. However, the intraocular pressure in the left eye could not be adequately controlled. Therefore, trabeculectomy with mitomycin C using limbal-based conjunctival flap was performed. Three hours after the surgery, the patient developed a large and diffuse filtering bleb, but no leakage occurred from the conjunctival scar. However, on the first postoperative day, leakage was noted and the conjunctiva was at the leakage point. The leakage resolved transiently, but recurred the next day. Severe keratoconjunctival epithelial failure was detected, and the patient was administrated 0.1% sodium hyaluronate eye drops six times daily. The epithelial failure improved, and many microcysts were detected on the bleb surface where the epithelial failure improved. The leakage resolved 2 days after initiation of the sodium hyaluronate eye drops. The microcysts disappeared and the bleb surface became smooth 1 month later. PMID:26664245

  15. Release of Photosynthetic Protein Catabolites by Blebbing from Thylakoids.

    PubMed Central

    Ghosh, S.; Hudak, K. A.; Dumbroff, E. B.; Thompson, J. E.

    1994-01-01

    Thylakoid proteins and their catabolites have been detected in lipid-protein particles isolated from the stroma of intact chloroplasts obtained from primary leaves of 2-week-old bean seedlings (Phaseolus vulgaris L. cv Kinghorn). The lipid-protein particles bear morphological resemblance to plastoglobuli seen in the chloroplasts of senescing leaves, but they are much smaller. They range from 10 to 320 nm in radius, are uniformly stained in thin sections visualized by transmission electron microscopy, and are discernible in the stroma of chloroplasts in corresponding thin-sectioned leaf tissue. The lipid-protein particles contain thylakoid lipids and are enriched in free fatty acids. Specifically, the free-to-esterified fatty acid ratio is about 1:1 in the particles compared to only 1:18 for corresponding thylakoid membranes. Western blot analyses indicate that these particles also contain thylakoid proteins and, in some cases, catabolites of these proteins including the CF1 [beta] and [gamma] subunits of ATPase, cytochrome f, and the 31- and 33-kD proteins of PSII. Lipid-protein particles with similar properties were generated in vitro from isolated, light-stressed thylakoids. Collectively, these data suggest that blebbing of lipid-protein particles may be a means of removing potentially destabilizing macromolecular catabolites from thylakoid membrane bilayers. PMID:12232430

  16. Erk regulation of actin capping and bundling by Eps8 promotes cortex tension and leader bleb-based migration.

    PubMed

    Logue, Jeremy S; Cartagena-Rivera, Alexander X; Baird, Michelle A; Davidson, Michael W; Chadwick, Richard S; Waterman, Clare M

    2015-07-11

    Within the confines of tissues, cancer cells can use blebs to migrate. Eps8 is an actin bundling and capping protein whose capping activity is inhibited by Erk, a key MAP kinase that is activated by oncogenic signaling. We tested the hypothesis that Eps8 acts as an Erk effector to modulate actin cortex mechanics and thereby mediate bleb-based migration of cancer cells. Cells confined in a non-adhesive environment migrate in the direction of a very large 'leader bleb.' Eps8 bundling activity promotes cortex tension and intracellular pressure to drive leader bleb formation. Eps8 capping and bundling activities act antagonistically to organize actin within leader blebs, and Erk mediates this effect. An Erk biosensor reveals concentrated kinase activity within leader blebs. Bleb contents are trapped by the narrow neck that separates the leader bleb from the cell body. Thus, Erk activity promotes actin bundling by Eps8 to enhance cortex tension and drive the bleb-based migration of cancer cells under non-adhesive confinement.

  17. Erk regulation of actin capping and bundling by Eps8 promotes cortex tension and leader bleb-based migration

    PubMed Central

    Logue, Jeremy S; Cartagena-Rivera, Alexander X; Baird, Michelle A; Davidson, Michael W; Chadwick, Richard S; Waterman, Clare M

    2015-01-01

    Within the confines of tissues, cancer cells can use blebs to migrate. Eps8 is an actin bundling and capping protein whose capping activity is inhibited by Erk, a key MAP kinase that is activated by oncogenic signaling. We tested the hypothesis that Eps8 acts as an Erk effector to modulate actin cortex mechanics and thereby mediate bleb-based migration of cancer cells. Cells confined in a non-adhesive environment migrate in the direction of a very large ‘leader bleb.’ Eps8 bundling activity promotes cortex tension and intracellular pressure to drive leader bleb formation. Eps8 capping and bundling activities act antagonistically to organize actin within leader blebs, and Erk mediates this effect. An Erk biosensor reveals concentrated kinase activity within leader blebs. Bleb contents are trapped by the narrow neck that separates the leader bleb from the cell body. Thus, Erk activity promotes actin bundling by Eps8 to enhance cortex tension and drive the bleb-based migration of cancer cells under non-adhesive confinement. DOI: http://dx.doi.org/10.7554/eLife.08314.001 PMID:26163656

  18. Unilateral, Linear Blue Rubber Bleb Nevus Syndrome (Bean's syndrome): An Unfamiliar Presentation: First Case from India

    PubMed Central

    Sancheti, Karan; Podder, Indrashis; Das, Anupam; Choudhury, Sourav; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2015-01-01

    Blue rubber bleb nevus syndrome (BRBNS) also called Bean's syndrome is a rare disorder characterized by multiple cutaneous venous malformations in association with visceral lesions, most commonly affecting the gastrointestinal tract. We report here, a 21-year-old woman patient, who presented with unilateral, blaschkoid distribution of cutaneous venous malformations along with blue rubber bleb nevus and recurrent episodes of hematochezia due to vascular lesions in the sigmoid colon; likely to be a case of BRBNS. The unusual unilateral, blaschkoid distribution of BRBNS prompted this present report. PMID:26677281

  19. Extracellular ATP Causes ROCK I-dependent Bleb Formation in P2X7-transfected HEK293 CellsV⃞

    PubMed Central

    Morelli, Anna; Chiozzi, Paola; Chiesa, Anna; Ferrari, Davide; Sanz, Juana M.; Falzoni, Simonetta; Pinton, Paolo; Rizzuto, Rosario; Olson, Michael F.; Di Virgilio, Francesco

    2003-01-01

    The P2X7 ATP receptor mediates the cytotoxic effect of extracellular ATP. P2X7-dependent cell death is heralded by dramatic plasma membrane bleb formation. Membrane blebbing is a complex phenomenon involving as yet poorly characterized intracellular pathways. We have investigated the effect of extracellular ATP on HEK293 cells transfected with the cytotoxic/pore-forming P2X7 receptor. Addition of ATP to P2X7-transfected, but not to wt P2X7-less, HEK293 cells caused massive membrane blebbing within 1–2 min. UTP, a nucleotide incapable of activating P2X7, had no early effects on cell shape and bleb formation. Bleb formation triggered by ATP was reversible and required extracellular Ca2+ and an intact cytoskeleton. Furthermore, it was completely prevented by preincubation with the P2X blocker oxidized ATP. It was recently observed that the ROCK protein is a key determinant of bleb formation. Preincubation of HEK293-P2X7 cells with the ROCK blocker Y-27632 completely prevented P2X7-dependent blebbing. Although ATP triggered cleavage of the ROCK I isoform in P2X7-transfected HEK293 cells, the wide range caspase inhibitor z-VAD-fluoromethylketone had no effect. These observations suggest that P2X7-dependent plasma membrane blebbing depends on the activation of the serine/threonine kinase ROCK I. PMID:12857854

  20. Trabeculectomy with ologen in secondary glaucomas following failed trabeculectomy with MMC: comparative study.

    PubMed

    El-Saied, H M A; Abdelhakim, M A S E

    2016-08-01

    PurposeWe aimed to assess the IOP-lowering effect of trabeculectomy with ologen in refractory secondary glaucoma following failed trabeculectomy with mitomycin C (MMC), and to compare its surgical outcome between open angle (SOAG) and angle closure (SACG) cases.MethodsThis is a prospective interventional comparative study conducted on 40 eyes (40 patients) with medically uncontrolled secondary glaucoma. Patients were divided into group A: 18 eyes (18 patients) with SOAG, and group B: 22 eyes (22 patients) with SACG. All patients underwent trabeculectomy with insertion of ologen implant. Intraocular pressure (IOP) measurement, SITA standard perimetry (Central 24-2), spectral domain optical coherence tomography (OCT) for retinal nerve fiber layer (RNFL) thickness, and anterior segment OCT for bleb morphology, were all done pre- and postoperatively. Primary outcome measures were comparing preoperative to postoperative measurements and also comparing these measurements between SOAG and SACG. All patients were examined up to 1 year.ResultsWhen preoperative IOP was compared with postoperative IOP, in each group, there was a statistically significant difference (P<0.001). IOP percentage difference was statistically insignificantly different between both groups except at 1 month. According to Moorfields bleb grading system; postoperative bleb was better than the bleb of the previously failed trabeculectomy (P<0.001), and there was a significant difference between group A and B regarding bleb area. Total success rate was 100%; in group A, complete success was 100%, while in group B it was 72.7% (P=0.016).ConclusionOur results suggest that Ologen may be a useful alternative to MMC in repeat trabeculectomy. PMID:27256305

  1. Thoracoscopic CO laser coagulation shrinkage of blebs in treatment of spontaneous pneumothorax

    NASA Astrophysics Data System (ADS)

    Sensaki, Koji; Arai, Tsunenori; Kikuchi, Keiichi; Takagi, Keigo; Tanaka, Susumu; Kikuchi, Makoto

    1992-06-01

    Spontaneous pneumothorax is a common disease in young people. Operative intervention has been done in most of the recurrent cases. Recently thoracoscopic treatment has been tested as a less invasive treatment modarity. We adopted carbon monoxide (CO) laser for thoracoscopic treatment of recurrent spontaneous pneumothorax. CO laser (wavelength; 5.4 micrometers ) could be delivered by chalcogenide glass (As - S) covered with a teflon sheath and ZnSe fiber tip. The sterilized flexible bronchoscope was inserted through the thoracoscopic outer sheath under local anesthesia. Shrinkage of blebs was obtained by non-contact method of CO laser irradiation. Laser power at the tip was 2.5 - 5 W and irradiation duration was 0.5 s each. Excellent shrinkage of bleb and bulla could be obtained by CO laser without perforation complication. Advantages of CO laser as a thoracoscopic treatment were: (1) capability of fiber delivery (flexible thoracoscopy was easy to operate and clear to visualize the blebs which were frequently found at the apical portion of the lung, and (2) shallow extinction length (good shrinkage of blebs, low risk of perforation, and thin layer of carbonization). In conclusion, our new technique of thoracoscopic CO laser irradiation was found to be a safe and effective treatment of spontaneous pneumothorax.

  2. Outcomes of Late-Onset Bleb-Related Endophthalmitis Treated with Pars Plana Vitrectomy

    PubMed Central

    Ohtomo, Kazuyoshi; Mayama, Chihiro; Ueta, Takashi; Nagahara, Miyuki

    2015-01-01

    Purpose. To investigate clinical results on bleb-related endophthalmitis (BRE) after trabeculectomy treated with pars plana vitrectomy (PPV) and to evaluate influence factors for visual prognosis. Methods. Investigating medical records retrospectively, BRE was defined as an endophthalmitis induced by bleb infection. A total of 2018 eyes of 1225 patients who had trabeculectomy between December 2000 and July 2013 were included in this study. Eleven eyes of 11 patients with BRE were performed with PPV. Results. The mean age was 56.6 years. The mean period between trabeculectomy and BRE onset was 7.4 years. The mean period from starting symptom to initiation of treatment for endophthalmitis (PSITE) was 2.3 days. Bleb leakages were observed in 7 eyes (64%). On culture examinations, highly pathogenic bacteria (HPB) were identified in 6 cases (55%). HPB infection was influence factors on visual disturbance (P = .0337). Number of HPB infections is significantly higher in poor visual outcome than without poor visual outcome (P = .0310). Conclusion. Visual prognosis of BRE treated by PPV is significantly better when the pathogenic bacteria are not HPB. Severe visual loss occurred with HPB infection even though patients had appropriate treatments. Physicians need to have careful consideration to prevent bleb infection after trabeculectomy with MMC. PMID:26495137

  3. Direct binding of C1q to apoptotic cells and cell blebs induces complement activation.

    PubMed

    Nauta, Alma J; Trouw, Leendert A; Daha, Mohamed R; Tijsma, Odette; Nieuwland, Rienk; Schwaeble, Wilhelm J; Gingras, Alexandre R; Mantovani, Alberto; Hack, Erik C; Roos, Anja

    2002-06-01

    Deficiency of early components of the classical pathway of complement, particularly C1q, predisposes to the development of systemic lupus erythematosus. Several studies have suggested an association between the classical complement pathway and the clearance of apoptotic cells. Mice with a targeted deletion of the C1q gene develop a lupus-like renal disease, which is associated with the presence of multiple apoptotic bodies in the kidney. In the present study we demonstrate that highly purified C1q binds to apoptotic cells and isolated blebs derived from these apoptotic cells. Binding of C1q to apoptotic cells occurs via the globular heads of C1q and induces activation of the classical complement pathway, as shown by the deposition of C4 and C3 on the surface of these cells and on cell-derived blebs. In addition, for the first time, we demonstrate that surface-bound C1q is present on a subpopulation of microparticles isolated from human plasma. Taken together, these observations demonstrate that C1q binds directly to apoptotic cells and blebs derived therefrom and support a role for C1q, possibly in concert with C4 and C3, in the clearance of apoptotic cells and blebs by the phagocytic system.

  4. An ezrin-rich, rigid uropod-like structure directs movement of amoeboid blebbing cells.

    PubMed

    Lorentzen, Anna; Bamber, Jeffrey; Sadok, Amine; Elson-Schwab, Ilan; Marshall, Christopher J

    2011-04-15

    Melanoma cells can switch between an elongated mesenchymal-type and a rounded amoeboid-type migration mode. The rounded 'amoeboid' form of cell movement is driven by actomyosin contractility resulting in membrane blebbing. Unlike elongated A375 melanoma cells, rounded A375 cells do not display any obvious morphological front-back polarisation, although polarisation is thought to be a prerequisite for cell movement. We show that blebbing A375 cells are polarised, with ezrin (a linker between the plasma membrane and actin cytoskeleton), F-actin, myosin light chain, plasma membrane, phosphatidylinositol (4,5)-bisphosphate and β1-integrin accumulating at the cell rear in a uropod-like structure. This structure does not have the typical protruding shape of classical leukocyte uropods, but, as for those structures, it is regulated by protein kinase C. We show that the ezrin-rich uropod-like structure (ERULS) is an inherent feature of polarised A375 cells and not a consequence of cell migration, and is necessary for cell invasion. Furthermore, we demonstrate that membrane blebbing is reduced at this site, leading to a model in which the rigid ezrin-containing structure determines the direction of a moving cell through localised inhibition of membrane blebbing.

  5. The management of ophthalmic involvement in blue rubber bleb nevus syndrome

    PubMed Central

    Petek, Bradley; Jones, Robin L.

    2014-01-01

    Objective: Blue rubber bleb nevus syndrome is a rare vascular disease most commonly associated with venous malformations of the skin and the gastrointestinal tract. Few ophthalmic cases have been reported to date, and no clear treatment regimen exists. We describe the case of a 59-year-old man, along with a review of literature, to help in the future diagnosis and treatment of patients with the disease. Methods: This paper is an observational case report and a review of medical literature on the syndrome from 1981 to present. Results: Our patient developed a dural arteriovenous fistula in his orbit after being diagnosed with a familial form of blue rubber bleb nevus syndrome. Multiple endovascular embolization procedures eliminated all of his ocular symptoms. Surgical procedures were also successful in other cases reviewed, and similar symptoms were seen across cases. Conclusions: Comparing our case with other ophthalamic reports in literature, surgical intervention appears to be a plausible long-term treatment for optic manifestations of blue rubber bleb nevus syndrome. Systemic therapies, including sirolimus and corticosteroids, have had limited success in the long-term treatment of other forms of blue rubber bleb nevus syndrome, and therefore are not recommended in the treatment of ocular symptoms.

  6. Membrane Protein Mobility and Orientation Preserved in Supported Bilayers Created Directly from Cell Plasma Membrane Blebs.

    PubMed

    Richards, Mark J; Hsia, Chih-Yun; Singh, Rohit R; Haider, Huma; Kumpf, Julia; Kawate, Toshimitsu; Daniel, Susan

    2016-03-29

    Membrane protein interactions with lipids are crucial for their native biological behavior, yet traditional characterization methods are often carried out on purified protein in the absence of lipids. We present a simple method to transfer membrane proteins expressed in mammalian cells to an assay-friendly, cushioned, supported lipid bilayer platform using cell blebs as an intermediate. Cell blebs, expressing either GPI-linked yellow fluorescent proteins or neon-green fused transmembrane P2X2 receptors, were induced to rupture on glass surfaces using PEGylated lipid vesicles, which resulted in planar supported membranes with over 50% mobility for multipass transmembrane proteins and over 90% for GPI-linked proteins. Fluorescent proteins were tracked, and their diffusion in supported bilayers characterized, using single molecule tracking and moment scaling spectrum (MSS) analysis. Diffusion was characterized for individual proteins as either free or confined, revealing details of the local lipid membrane heterogeneity surrounding the protein. A particularly useful result of our bilayer formation process is the protein orientation in the supported planar bilayer. For both the GPI-linked and transmembrane proteins used here, an enzymatic assay revealed that protein orientation in the planar bilayer results in the extracellular domains facing toward the bulk, and that the dominant mode of bleb rupture is via the "parachute" mechanism. Mobility, orientation, and preservation of the native lipid environment of the proteins using cell blebs offers advantages over proteoliposome reconstitution or disrupted cell membrane preparations, which necessarily result in significant scrambling of protein orientation and typically immobilized membrane proteins in SLBs. The bleb-based bilayer platform presented here is an important step toward integrating membrane proteomic studies on chip, especially for future studies aimed at understanding fundamental effects of lipid interactions

  7. Membrane Protein Mobility and Orientation Preserved in Supported Bilayers Created Directly from Cell Plasma Membrane Blebs.

    PubMed

    Richards, Mark J; Hsia, Chih-Yun; Singh, Rohit R; Haider, Huma; Kumpf, Julia; Kawate, Toshimitsu; Daniel, Susan

    2016-03-29

    Membrane protein interactions with lipids are crucial for their native biological behavior, yet traditional characterization methods are often carried out on purified protein in the absence of lipids. We present a simple method to transfer membrane proteins expressed in mammalian cells to an assay-friendly, cushioned, supported lipid bilayer platform using cell blebs as an intermediate. Cell blebs, expressing either GPI-linked yellow fluorescent proteins or neon-green fused transmembrane P2X2 receptors, were induced to rupture on glass surfaces using PEGylated lipid vesicles, which resulted in planar supported membranes with over 50% mobility for multipass transmembrane proteins and over 90% for GPI-linked proteins. Fluorescent proteins were tracked, and their diffusion in supported bilayers characterized, using single molecule tracking and moment scaling spectrum (MSS) analysis. Diffusion was characterized for individual proteins as either free or confined, revealing details of the local lipid membrane heterogeneity surrounding the protein. A particularly useful result of our bilayer formation process is the protein orientation in the supported planar bilayer. For both the GPI-linked and transmembrane proteins used here, an enzymatic assay revealed that protein orientation in the planar bilayer results in the extracellular domains facing toward the bulk, and that the dominant mode of bleb rupture is via the "parachute" mechanism. Mobility, orientation, and preservation of the native lipid environment of the proteins using cell blebs offers advantages over proteoliposome reconstitution or disrupted cell membrane preparations, which necessarily result in significant scrambling of protein orientation and typically immobilized membrane proteins in SLBs. The bleb-based bilayer platform presented here is an important step toward integrating membrane proteomic studies on chip, especially for future studies aimed at understanding fundamental effects of lipid interactions

  8. How Does a Failing School Stop Failing?

    ERIC Educational Resources Information Center

    Warren-Gross, Laura

    2009-01-01

    The author's school had just been labeled a failing school by No Child Left Behind when its new principal arrived in the fall of 2007. In this demoralizing climate, teachers can get frustrated and choose to give up, or they can rise to the challenge, create a plan for improvement, and plunge into uncharted waters. This article discusses how the…

  9. Realistic non-Newtonian viscosity modelling highlights hemodynamic differences between intracranial aneurysms with and without surface blebs.

    PubMed

    Hippelheuser, James E; Lauric, Alexandra; Cohen, Alex D; Malek, Adel M

    2014-11-28

    Most computational fluid dynamic (CFD) simulations of aneurysm hemodynamics assume constant (Newtonian) viscosity, even though blood demonstrates shear-thinning (non-Newtonian) behavior. We sought to evaluate the effect of this simplifying assumption on hemodynamic forces within cerebral aneurysms, especially in regions of low wall shear stress, which are associated with rupture. CFD analysis was performed for both viscosity models using 3D rotational angiography volumes obtained for 26 sidewall aneurysms (12 with blebs, 12 ruptured), and parametric models incorporating blebs at different locations (inflow/outflow zone). Mean and lowest 5% values of time averaged wall shear stress (TAWSS) computed over the dome were compared using Wilcoxon rank-sum test. Newtonian modeling not only resulted in higher aneurysmal TAWSS, specifically in areas of low flow and blebs, but also showed no difference between aneurysms with or without blebs. In contrast, for non-Newtonian analysis, bleb-bearing aneurysms showed significantly lower 5% TAWSS compared to those without (p=0.005), despite no significant difference in mean dome TAWSS (p=0.32). Non-Newtonian modeling also accentuated the differences in dome TAWSS between ruptured and unruptured aneurysms (p<0.001). Parametric models further confirmed that realistic non-Newtonian viscosity resulted in lower bleb TAWSS and higher focal viscosity, especially when located in the outflow zone. The results show that adopting shear-thinning non-Newtonian blood viscosity in CFD simulations of intracranial aneurysms uncovered hemodynamic differences induced by bleb presence on aneurysmal surfaces, and significantly improved discriminant statistics used in risk stratification. These findings underline the possible implications of using a realistic model of blood viscosity in predictive computational hemodynamics. PMID:25446269

  10. Failed induction of labor.

    PubMed

    Schoen, Corina; Navathe, Reshama

    2015-10-01

    Induction of labor will affect almost a quarter of all pregnancies, but historically there has been no generally accepted definition of failed induction of labor. Only recently have studies analyzed the lengths of latent labor that are associated with successful labor induction ending in a vaginal delivery, and recommendations for uniformity in the diagnosis of failed induction have largely resulted from this data. This review assesses the most recent and inclusive definition for failed induction, risk factors associated with failure, complications, and special populations that may be at risk for a failed induction.

  11. Lamellipodia and Membrane Blebs Drive Efficient Electrotactic Migration of Rat Walker Carcinosarcoma Cells WC 256

    PubMed Central

    Sroka, Jolanta; Krecioch, Izabela; Zimolag, Eliza; Lasota, Slawomir; Rak, Monika; Kedracka-Krok, Sylwia; Borowicz, Pawel; Gajek, Marta; Madeja, Zbigniew

    2016-01-01

    The endogenous electric field (EF) may provide an important signal for directional cell migration during wound healing, embryonic development and cancer metastasis but the mechanism of cell electrotaxis is poorly understood. Additionally, there is no research addressing the question on the difference in electrotactic motility of cells representing various strategies of cell movement—specifically blebbing vs. lamellipodial migration. In the current study we constructed a unique experimental model which allowed for the investigation of electrotactic movement of cells of the same origin but representing different modes of cell migration: weakly adherent, spontaneously blebbing (BC) and lamellipodia forming (LC) WC256 cells. We report that both BC and LC sublines show robust cathodal migration in a physiological EF (1–3 V/cm). The directionality of cell movement was completely reversible upon reversing the field polarity. However, the full reversal of cell direction after the change of EF polarity was much faster in the case of BC (10 minutes) than LC cells (30 minutes). We also investigated the distinct requirements for Rac, Cdc42 and Rho pathways and intracellular Ca2+ in electrotaxis of WC256 sublines forming different types of cell protrusions. It was found that Rac1 is required for directional movement of LC to a much greater extent than for BC, but Cdc42 and RhoA are more crucial for BC than for LC cells. The inhibition of ROCK did not affect electrotaxis of LC in contrast to BC cells. The results also showed that intracellular Ca2+ is essential only for the electrotactic reaction of BC cells. Moreover, inhibition of MLCK and myosin II did not affect the electrotaxis of LC in contrast to BC cells. In conclusion, our results revealed that both lamellipodia and membrane blebs can efficiently drive electrotactic migration of WC 256 carcinosarcoma cells, however directional migration is mediated by different signalling pathways. PMID:26863616

  12. Subcapsular Sinus Macrophage Fragmentation and CD169+ Bleb Acquisition by Closely Associated IL-17-Committed Innate-Like Lymphocytes

    PubMed Central

    Gray, Elizabeth E.; Friend, Sherree; Suzuki, Kazuhiro; Phan, Tri Giang; Cyster, Jason G.

    2012-01-01

    Subcapsular sinus macrophages (SSMs) in lymph nodes are rapidly exposed to antigens arriving in afferent lymph and have a role in their capture and display to B cells. In tissue sections SSMs exhibit long cellular processes and express high amounts of CD169. Here, we show that many of the cells present in lymph node cell suspensions that stain for CD169 are not macrophages but lymphocytes that have acquired SSM-derived membrane blebs. The CD169 bleb+ lymphocytes are enriched for IL-17 committed IL-7RαhiCCR6+ T cells and NK cells. In addition, the CD169 staining detected on small numbers of CD11chi dendritic cells is frequently associated with membrane blebs. Counter intuitively the CD169 bleb+ lymphocytes are mostly CD4 and CD8 negative whereas many SSMs express CD4. In situ, many IL-7Rαhi cells are present at the subcapsular sinus and interfollicular regions and migrate in close association with CD169+ macrophages. These findings suggest SSMs undergo fragmentation during tissue preparation and release blebs that are acquired by closely associated cells. They also suggest an intimate crosstalk between SSMs and IL-17 committed innate-like lymphocytes that may help provide early protection of the lymph node against lymph-borne invaders. PMID:22675532

  13. A novel bleb-dependent polysaccharide export system in nitrogen-fixing Azotobacter vinelandii subjected to low nitrogen gas levels.

    PubMed

    Hashimoto, Wataru; Miyamoto, Yukiko; Yamamoto, Mayumi; Yoneyama, Fuminori; Murata, Kousaku

    2013-03-01

    The alginate biofilm-producing bacterium Azotobacter vinelandii aerobically fixes nitrogen by oxygen-sensitive nitrogenases. Here we investigated the bacterial response to nitrogen/oxygen gas mixtures. A. vinelandii cells were cultured in nitrogen-free minimal media containing gas mixtures differing in their ratios of nitrogen and oxygen. The bacteria did not grow at oxygen concentrations >75% but grew well in the presence of 5% nitrogen/25% oxygen. Growth of wild-type and alginate-deficient strains when cultured with 50% oxygen did not differ substantially, indicating that alginate is not required for the protection of nitrogenases from oxygen damage. In response to decreasing nitrogen levels, A. vinelandii produced greater amounts of alginate, accompanied by the formation of blebs on the cell surface. The encystment of vegetative cells occurred in tandem with the release of blebs and the development of a multilayered exine. Immunoelectron microscopy using anti alginate-antibody revealed that the blebs contained alginate molecules. By contrast, alginate-deficient mutants could not form blebs. Taken together, our data provide evidence for a novel bleb-dependent polysaccharide export system in A. vinelandii that is activated in response to low nitrogen gas levels.

  14. Filter assembly for metallic and intermetallic tube filters

    DOEpatents

    Alvin, Mary Anne; Lippert, Thomas E.; Bruck, Gerald J.; Smeltzer, Eugene E.

    2001-01-01

    A filter assembly (60) for holding a filter element (28) within a hot gas cleanup system pressure vessel is provided, containing: a filter housing (62), said filter housing having a certain axial length and having a peripheral sidewall, said sidewall defining an interior chamber (66); a one piece, all metal, fail-safe/regenerator device (68) within the interior chamber (66) of the filter housing (62) and/or extending beyond the axial length of the filter housing, said device containing an outward extending radial flange (71) within the filter housing for seating an essential seal (70), the device also having heat transfer media (72) disposed inside and screens (80) for particulate removal; one compliant gasket (70) positioned next to and above the outward extending radial flange of the fail-safe/regenerator device; and a porous metallic corrosion resistant superalloy type filter element body welded at the bottom of the metal fail-safe/regenerator device.

  15. Human intrahepatic biliary epithelial cells engulf blebs from their apoptotic peers

    PubMed Central

    Rong, G-H; Yang, G-X; Ando, Y; Zhang, W; He, X-S; Leung, P S C; Coppel, R L; Ansari, A A; Zhong, R; Gershwin, M E

    2013-01-01

    The phagocytic clearance of apoptotic cells is critical for tissue homeostasis; a number of non-professional phagocytic cells, including epithelial cells, can both take up and process apoptotic bodies, including the release of anti-inflammatory mediators. These observations are particularly important in the case of human intrahepatic biliary cells (HiBEC), because such cells are themselves a target of destruction in primary biliary cirrhosis, the human autoimmune disease. To address the apoptotic ability of HiBECs, we have focused on their ability to phagocytize apoptotic blebs from autologous HiBECs. In this study we report that HiBEC cells demonstrate phagocytic function from autologous HiBEC peers accompanied by up-regulation of the chemokines CCL2 [monocyte chemotactic protein-1 (MCP-1)] and CXCL8 [interleukin (IL)-8]. In particular, HiBEC cells express the phagocytosis-related receptor phosphatidylserine receptors (PSR), implying that HiBECs function through the ‘eat-me’ signal phosphatidylserine expressed by apoptotic cells. Indeed, although HiBEC cells acquire antigen-presenting cell (APC) function, they do not change the expression of classic APC function surface markers after engulfment of blebs, both with and without the presence of Toll-like receptor (TLR) stimulation. These results are important not only for understanding of the normal physiological function of HiBECs, but also explain the inflammatory potential and reduced clearance of HiBEC cells following the inflammatory cascade in primary biliary cirrhosis. PMID:23480189

  16. Blood flow drives lumen formation by inverse membrane blebbing during angiogenesis in vivo.

    PubMed

    Gebala, Véronique; Collins, Russell; Geudens, Ilse; Phng, Li-Kun; Gerhardt, Holger

    2016-04-01

    How vascular tubes build, maintain and adapt continuously perfused lumens to meet local metabolic needs remains poorly understood. Recent studies showed that blood flow itself plays a critical role in the remodelling of vascular networks, and suggested it is also required for the lumenization of new vascular connections. However, it is still unknown how haemodynamic forces contribute to the formation of new vascular lumens during blood vessel morphogenesis. Here we report that blood flow drives lumen expansion during sprouting angiogenesis in vivo by inducing spherical deformations of the apical membrane of endothelial cells, in a process that we have termed inverse blebbing. We show that endothelial cells react to these membrane intrusions by local and transient recruitment and contraction of actomyosin, and that this mechanism is required for single, unidirectional lumen expansion in angiogenic sprouts. Our work identifies inverse membrane blebbing as a cellular response to high external pressure. We show that in the case of blood vessels such membrane dynamics can drive local cell shape changes required for global tissue morphogenesis, shedding light on a pressure-driven mechanism of lumen formation in vertebrates.

  17. Cellular regulation of extension and retraction of pseudopod-like blebs produced by nanosecond pulsed electric field (nsPEF).

    PubMed

    Rassokhin, Mikhail A; Pakhomov, Andrei G

    2014-07-01

    Recently we described a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells exposed to nanosecond pulsed electric field (nsPEF). In Ca(2+)-free buffer such exposure initiates formation of pseudopod-like blebs (PLBs), protrusive cylindrical cell extensions that are distinct from apoptotic and necrotic blebs. PLBs nucleate predominantly on anode-facing cell pole and extend toward anode during nsPEF exposure. Bleb extension depends on actin polymerization and availability of actin monomers. Inhibition of intracellular Ca(2+), cell contractility, and RhoA produced no effect on PLB initiation. Meanwhile, inhibition of WASP by wiskostatin causes dose-dependent suppression of PLB growth. Soon after the end of nsPEF exposure PLBs lose directionality of growth and then retract. Microtubule toxins nocodazole and paclitaxel did not show immediate effect on PLBs; however, nocodazole increased mobility of intracellular components during PLB extension and retraction. Retraction of PLBs is produced by myosin activation and the corresponding increase in PLB cortex contractility. Inhibition of myosin by blebbistatin reduces retraction while inhibition of RhoA-ROCK pathway by Y-27632 completely prevents retraction. Contraction of PLBs can produce cell translocation resembling active cell movement. Overall, the formation, properties, and life cycle of PLBs share common features with protrusions associated with ameboid cell migration. PLB life cycle may be controlled through activation of WASP by its upstream effectors such as Cdc42 and PIP2, and main ROCK activator-RhoA. Parallels between pseudopod-like blebbing and motility blebbing may provide new insights into their underlying mechanisms.

  18. Mechanism of Spontaneous Blebbing Motion of an Oil–Water Interface: Elastic Stress Generated by a Lamellar–Lamellar Transition

    DOE PAGES

    Sumino, Yutaka; Yamada, Norifumi L.; Nagao, Michihiro; Honda, Takuya; Kitahata, Hiroyuki; Melnichenko, Yuri B.; Seto, Hideki

    2016-03-03

    A quaternary system composed of surfactant, cosurfactant, oil, and water showing spontaneous motion of the oil-water interface-under far-from-equilibrium condition is studied in order to understand nanometer-scale structures and their roles in spontaneous motion. We characterize the interfacial motion by the repetitive. extension and retraction of spherical protrusions at the interface, i.e, blebbing motion. During, the, blebbing motion, elastic aggregates are accumulated, which were characterized as surfactant lamellar structures with mean repeat distances d of 25 to 40 nm. The relationship between the structure formation and, the dynamics of the interfacial motion is still unclear. In the present study, we findmore » that a new lamellar structure with d larger than. 80 run is formed at. the blebbing oil-water interface,. while the resultant elastic aggregates, which are the one reported before, have a lamellar structure with smaller d (25 to 40 nm). Such transition of lamellar structures from the larger d to smaller d is induced by a penetration of surfactants from an aqueous phase into the aggregates. We propose a model in which elastic stress generated by the transition-drives the blebbing motion at the interface. These results explain the link between nanometer-scale transition of lamellar structure and millimeter-scale dynamics at an oil water interface.« less

  19. Circus movements and blebbing locomotion in dissociated embryonic cells of an amphibian, Xenopus laevis.

    PubMed

    Johnson, K E

    1976-12-01

    Circus movements, which involve the circumferential rotation of a hyaline cytoplasmic protrusion, occur in cells obtained by EDTA dissociation of gastrula-stage Xenopus laevis embryos. Only a few dissociated blastula-stage cells show circus movements, more early gastrula-stage cells show them, and nearly all late gastrula-stage cells show them. Circus movements cease in cells prior to mitosis and begin again in daughter cells after mitosis is completed. In early gastrulae, only 17% of prospective endodermal cells show circus movements while 79% of prospective mesodern, archenteric roof, and posterior neural ectoderm do so. Isolated cells as well as groups of cells in vitro are often propelled by circus movements. There is an obvious antagonism between cell contact and circus movements. The morphogenetic significance of circus movements and blebbing locomotion is discussed.

  20. Novel Backup Filter Device for Candle Filters

    SciTech Connect

    Bishop, B.; Goldsmith, R.; Dunham, G.; Henderson, A.

    2002-09-18

    The currently preferred means of particulate removal from process or combustion gas generated by advanced coal-based power production processes is filtration with candle filters. However, candle filters have not shown the requisite reliability to be commercially viable for hot gas clean up for either integrated gasifier combined cycle (IGCC) or pressurized fluid bed combustion (PFBC) processes. Even a single candle failure can lead to unacceptable ash breakthrough, which can result in (a) damage to highly sensitive and expensive downstream equipment, (b) unacceptably low system on-stream factor, and (c) unplanned outages. The U.S. Department of Energy (DOE) has recognized the need to have fail-safe devices installed within or downstream from candle filters. In addition to CeraMem, DOE has contracted with Siemens-Westinghouse, the Energy & Environmental Research Center (EERC) at the University of North Dakota, and the Southern Research Institute (SRI) to develop novel fail-safe devices. Siemens-Westinghouse is evaluating honeycomb-based filter devices on the clean-side of the candle filter that can operate up to 870 C. The EERC is developing a highly porous ceramic disk with a sticky yet temperature-stable coating that will trap dust in the event of filter failure. SRI is developing the Full-Flow Mechanical Safeguard Device that provides a positive seal for the candle filter. Operation of the SRI device is triggered by the higher-than-normal gas flow from a broken candle. The CeraMem approach is similar to that of Siemens-Westinghouse and involves the development of honeycomb-based filters that operate on the clean-side of a candle filter. The overall objective of this project is to fabricate and test silicon carbide-based honeycomb failsafe filters for protection of downstream equipment in advanced coal conversion processes. The fail-safe filter, installed directly downstream of a candle filter, should have the capability for stopping essentially all particulate

  1. ELLA Fails Four Tests.

    ERIC Educational Resources Information Center

    Little, Graham

    1998-01-01

    Suggests that ELLA (English Language and Literacy Assessment ) implemented in New South Wales, Australia, fails four tests for sound diagnostic assessment set out in a standard reference (K.W. Howell et al. "Curriculum Based Evaluation")--tests for logicality, reliability, validity, and accuracy and practicality. (RS)

  2. Fail safe logic design

    NASA Astrophysics Data System (ADS)

    Shield, I.

    1983-03-01

    Ideally, a circuit is said to be fail safe, if for every possible failure configuration, the circuit results in a safe side output. In order to guarantee safe side failures, it is imperative that the circuit detects any faults within it. A suitable procedure for doing this can be based on an error detecting code, such as the K out of N code. A number of circuit types are considered, taking into account a fault tolerant circuit, a fault secure circuit, a self testing circuit, a self checking circuit, a self checking checker, and a fail safe circuit. Attention is given to the realization of combinational circuits, aspects of safety and reliability, sequential circuits, the realization of sequential circuits, the occurrence of clock failure, and the design procedure.

  3. Who fails lantern tests?

    PubMed

    Cole, B L; Vingrys, A J

    1983-05-01

    A battery of clinical colour vision tests was given to a group of 100 observers with abnormal colour vision who were also tested on the Farnsworth lantern and the Holmes-Wright lanterns types A and B. It was found that clinical colour vision tests are imperfect predictors of lantern test performance. However, observers classified as having a 'severe' colour vision defect were found to fail the lantern tests but only one half to two-thirds of those who fail the lantern tests can be identified in this way. It is not possible to identify with certainty any of the people likely to pass the lantern tests: about one-third to two-thirds of observers classified as being mildly affected fail the lantern tests. The Farnsworth D-15 and City University tests were found to be the best predictors of lantern test performance but other tests such as the Nagel anomaloscope, the H-16, L'Anthony's desaturated test can also be used. The lack of a strong correlation between clinical tests and the recognition of the small coloured stimuli presented by the lantern tests suggests that clinical tests do not test the same aspect of colour vision that is important to the recognition of signal lights. For this reason lantern tests should be retained for occupational testing of colour vision.

  4. Sequential Therapy with Saratin, Bevacizumab and Ilomastat to Prolong Bleb Function following Glaucoma Filtration Surgery in a Rabbit Model.

    PubMed

    Martorana, Gina M; Schaefer, Jamie L; Levine, Monica A; Lukowski, Zachary L; Min, Jeff; Meyers, Craig A; Schultz, Gregory S; Sherwood, Mark B

    2015-01-01

    To determine if sequential treatment with Bevacizumab (Avastin), a monoclonal, VEGF antibody that blocks angiogenesis; Saratin, a 12 kD polypeptide with anti-inflammatory and anti-thrombotic properties; and Ilomastat, a matrix metalloproteinase (MMP) inhibitor, prolongs bleb life following glaucoma filtration surgery (GFS) in a rabbit model. Thirty-two New Zealand White rabbits (eight rabbits per group) underwent GFS in the left eye. Group 1 received a perioperative injection of both Saratin and Bevacizumab, and later, subconjuctival injections of Ilomastat on days 8 and 15. Group 2 received only Saratin perioperatively, and also received Ilomastat injections on days 8 and 15. Group 3, the negative control, received a single perioperative injection of Balanced Saline Solution (BSS) along with post-operative BSS injections on days 8 and 15. Group 4, the positive control, received topical treatment with Mitomycin-C (MMC) at the time of surgery with no further treatment. Blebs were evaluated by an observer masked to treatment every third day. Histology was obtained on two eyes in each group on post-op day twelve as well as all eyes following bleb failure. Eyes in group 1 had a mean bleb survival time of 29 ± 2.7 days, whereas those in group 2 that received the experimental treatment without Bevacizumab had a mean survival time of 25.5 ± 2.7 days. An ANOVA test showed that the Saratin/Ilomastat/Bevacizumab group demonstrated a significant prolongation of bleb survival compared to the BSS control-mean survival time of 19.7 ±2.7 days-(p = 0.0252) and was not significantly different from the MMC positive control group (p = 0.4238)-mean survival time of 32.5 ± 3.3. From tissue histology at day 12, the four different groups showed marked differences in the cellularity and capsule fibrosis. The MMC eyes showed minimal cellularity, were avascular and had minimal fibrous tissue. BSS group showed high cellularity, moderate to high fibrosis, and thicker and more defined

  5. Multiple orbital venous malformations presenting with enophthalmos in a patient with presumed blue rubber bleb nevus syndrome.

    PubMed

    Tuncer, Samuray; Peksayar, Gonul; Tefekli, Esra Guney; Ayranci, Ozen; Demirci, Hakan

    2008-01-01

    A 27-year-old white woman presented with enophthalmos in the right eye. The visual acuity was 20/20 in both eyes. External examination showed 7 mm of enophthalmos of the right eye with deepened superior palpebral sulcus compared with the left eye. After Valsalva maneuver, the right eye became 4-mm exophthalmic compared with the left eye. Extraocular movements were full. There was no palpable orbital mass or diplopia. MRI showed diffuse enhancing intraconal orbital and nasopharyngeal masses consistent with venous malformations in the right orbit. Systemic evaluation revealed bluish vascular lesions on the hard and soft palates, and the pretibial area of her right leg. These findings were suggestive of blue rubber bleb nevus syndrome. The patient was observed, and her clinical findings remained stable for 12 months. Enophthalmos can be a rare initial presentation of blue rubber bleb nevus syndrome and patients with ophthalmic involvement should undergo systemic evaluation including gastrointestinal, dermatologic, and otorhinolaryngologic examination. PMID:18645452

  6. Failing by design.

    PubMed

    McGrath, Rita Gunther

    2011-04-01

    It's hardly news that business leaders work in increasingly uncertain environments, where failures are bound to be more common than successes. Yet if you ask executives how well, on a scale of one to 10, their organizations learn from failure, you'll often get a sheepish "Two-or maybe three" in response. Such organizations are missing a big opportunity: Failure may be inevitable but, if managed well, can be very useful. A certain amount of failure can help you keep your options open, find out what doesn't work, create the conditions to attract resources and attention, make room for new leaders, and develop intuition and skill. The key to reaping these benefits is to foster "intelligent failure" throughout your organization. McGrath describes several principles that can help you put intelligent failure to work. You should decide what success and failure would look like before you start a project. Document your initial assumptions, test and revise them as you go, and convert them into knowledge. Fail fast-the longer something takes, the less you'll learn-and fail cheaply, to contain your downside risk. Limit the number of uncertainties in new projects, and build a culture that tolerates, and sometimes even celebrates, failure. Finally, codify and share what you learn. These principles won't give you a means of avoiding all failures down the road-that's simply not realistic. They will help you use small losses to attain bigger wins over time.

  7. Bleb formation is induced by alkaline but not acidic pH in estrogen receptor silenced breast cancer cells.

    PubMed

    Khajah, Maitham A; Mathew, Princy M; Alam-Eldin, Nada S; Luqmani, Yunus A

    2015-04-01

    De novo and acquired resistance to endocrine-based therapies in breast cancer occurs in parallel with epithelial to mesenchymal transition (EMT), which is associated with enhanced proliferative and metastatic potential, and poor clinical outcome. We have established several endocrine insensitive breast cancer lines by shRNA-induced depletion of estrogen receptor (ER) by transfection of MCF7 cells. All of these exhibit EMT. We have previously reported that brief exposure of specifically ER- breast cancer cells, to extracellular alkaline pH, results in cell rounding and segregation, and leads to enhanced invasive potential. In this study we describe more detailed morphological changes and compare these with cell exposure to acidic pH. Morphological changes and localization of various molecules critical for cell adhesion and motility, associated with pH effects, were assessed by live cell microscopy, electron microscopy, and immunofluorescence. Exposure of either ER- or ER+ breast cancer cells to extracellular acidic pH did not induce significant changes in morphological appearance. Conversely, brief exposure of specifically ER silenced cells, to alkaline pH, resulted in cell contractolation and formation of bleb-like actin-rich structures which were evenly distributed on the outer membrane. Integrin α2, FAK, and JAM-1 were found in the cytoplasm streaming into the newly formed blebs. These blebs appear to be related to cell polarity and movement. Pre-treatment with cytochalasin-D or inhibitors of Rho or MLCK prevented both contractolation and bleb formation. Our data suggest that the effect of pH on the microenvironment of endocrine resistant breast cancer cells needs to be more extensively investigated. Alkaline, rather than acidic pH, appears to induce dramatic morphological changes, and enhances their invasive capabilities, through re-organization of cortical actin. PMID:25672508

  8. Application of 5-Fluorouracil-Polycaprolactone Sustained-Release Film in Ahmed Glaucoma Valve Implantation Inhibits Postoperative Bleb Scarring in Rabbit Eyes.

    PubMed

    Bi, Xiu-Zeng; Pan, Wei-Hua; Yu, Xin-Ping; Song, Zong-Ming; Ren, Zeng-Jin; Sun, Min; Li, Cong-Hui; Nan, Kai-Hui

    2015-01-01

    This study was designed to investigate whether 5-fluorouracil (5-Fu)-polycaprolactone sustained-release film in Ahmed glaucoma valve implantation inhibits postoperative bleb scarring in rabbit eyes. Eighteen New Zealand white rabbits were randomly divided into three groups (A, B and C; n = 6 per group). Group A received combined 5-Fu-polycaprolactone sustained-release film application and Ahmed glaucoma valve implantation, group B received local infiltration of 5-Fu and Ahmed glaucoma valve implantation, and group C received Ahmed glaucoma valve implantation. Postoperative observations were made of the anterior segment, intraocular pressure, central anterior chamber depth, blebs, drainage tube, and accompanying ciliary body detachment. The pathology of the blebs and surrounding tissues were observed at month 3 postoperatively. We revealed that the 5-Fu-polycaprolactone sustained-release film maintained a release concentration range of 13.7 ± 0.12 to 37.41 ± 0.47 μg/ml over three months in vitro. Postoperatively, diffuse blebs with ridges were found in all eyes in group A, two blebs were observed in group B, and no bleb formation was present in group C. The postoperative central anterior chamber depth in group A was significantly less than that of the other two groups. The postoperative intraocular pressure of group A stabilized at 6.33-8.67 mmHg, whereas that of group C gradually remained at 7.55-10.02 mmHg. The histopathology showed that the fibrous tissue thickness of the blebs in group A was significantly thinner than that of the other groups. We conclude that the 5-Fu-polycaprolactone sustained-release film had a sustained drug release effect, which promoted the inhibition of bleb scarring after Ahmed glaucoma valve implantation.

  9. Application of 5-Fluorouracil-Polycaprolactone Sustained-Release Film in Ahmed Glaucoma Valve Implantation Inhibits Postoperative Bleb Scarring in Rabbit Eyes

    PubMed Central

    Bi, Xiu-Zeng; Pan, Wei-Hua; Yu, Xin-Ping; Song, Zong-Ming; Ren, Zeng-Jin; Sun, Min; Li, Cong-Hui; Nan, Kai-Hui

    2015-01-01

    This study was designed to investigate whether 5-fluorouracil (5-Fu)-polycaprolactone sustained-release film in Ahmed glaucoma valve implantation inhibits postoperative bleb scarring in rabbit eyes. Eighteen New Zealand white rabbits were randomly divided into three groups (A, B and C; n = 6 per group). Group A received combined 5-Fu-polycaprolactone sustained-release film application and Ahmed glaucoma valve implantation, group B received local infiltration of 5-Fu and Ahmed glaucoma valve implantation, and group C received Ahmed glaucoma valve implantation. Postoperative observations were made of the anterior segment, intraocular pressure, central anterior chamber depth, blebs, drainage tube, and accompanying ciliary body detachment. The pathology of the blebs and surrounding tissues were observed at month 3 postoperatively. We revealed that the 5-Fu-polycaprolactone sustained-release film maintained a release concentration range of 13.7 ± 0.12 to 37.41 ± 0.47 μg/ml over three months in vitro. Postoperatively, diffuse blebs with ridges were found in all eyes in group A, two blebs were observed in group B, and no bleb formation was present in group C. The postoperative central anterior chamber depth in group A was significantly less than that of the other two groups. The postoperative intraocular pressure of group A stabilized at 6.33–8.67 mmHg, whereas that of group C gradually remained at 7.55–10.02 mmHg. The histopathology showed that the fibrous tissue thickness of the blebs in group A was significantly thinner than that of the other groups. We conclude that the 5-Fu-polycaprolactone sustained-release film had a sustained drug release effect, which promoted the inhibition of bleb scarring after Ahmed glaucoma valve implantation. PMID:26579716

  10. Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions

    PubMed Central

    Wessler, Timothy; Yang, Xiaofeng; Chen, Alex; Roach, Nathan; Elston, Timothy C.; Wang, Qi; Jacobson, Ken; Forest, M. Gregory

    2016-01-01

    Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs), whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D) posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model “learns” from the thin section transmission electron micrograph image (2D) or the “seed and growth” model image (3D). Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts. PMID:27015526

  11. Subconjunctival bevacizumab to augment trabeculectomy with mitomycin C in the management of failed glaucoma surgery

    PubMed Central

    Saeed, Ahmed M; AboulNasr, Tarek Tawfeek

    2014-01-01

    Purpose To provide a feasible solution to the problem of failed glaucoma surgery. The aim was to evaluate the efficacy and safety of the additional effects of a combined surgical approach. This approach augments the application of trabeculectomy with mitomycin C (MMC) by adding subconjunctival bevacizumab injection. The results were compared with those of trabeculectomy with only adjunctive MMC. Methods A randomized controlled prospective clinical trial included 28 eyes diagnosed with failed scarred bleb of a previous trabeculectomy. The eyes were divided into two equal groups: combined group A, “trabeculectomy with adjunctive MMC and subconjunctival bevacizumab,” and control group B, “trabeculectomy with adjunctive MMC only.” The main outcome results included the cumulative probability of surgical success, intraocular pressure (IOP) values, and number of IOP-lowering medications needed to achieve the target IOP. Results Group A achieved a cumulative probability of complete success of 0.769 and of qualified success of 0.231 at the end of the 24 month study period; group B achieved cumulative probabilities of 0.538 and 0.308, respectively. Group A achieved a lower mean IOP value than group B, with fewer antiglaucoma drugs at all postoperative visits, but this lower value did not reach a statistically significant level (P>0.05). There was no statistically significant difference between both groups regarding best corrected visual acuity, visual field parameters, operative and/or postoperative complications, and additional interventions. No significant adverse effects were caused by this combined approach. Conclusion Bevacizumab was not found to add much to the favorable long-term outcome of conventional trabeculectomy with MMC as a solution to the problem of scarred failed bleb. PMID:25246758

  12. Conservative treatment for late-onset bleb leaks after trabeculectomy with mitomycin C in patients with ocular surface disease

    PubMed Central

    Sagara, Hideto; Iida, Tomohiro; Saito, Kimimori; Noji, Hiroki; Ogasawara, Masashi; Oyamada, Hiroshi

    2012-01-01

    Background Sodium hyaluronate and autologous serum eye drops are used to treat ocular surface disease (OSD) and are reported to prevent and treat late-onset bleb leaks following trabeculectomy with mitomycin C. In this study, we evaluated the efficacy of a combination of sodium hyaluronate and autologous serum eye drops and treatment for obstructive meibomian gland dysfunction as a therapy for late-onset bleb leaks after trabeculectomy with mitomycin C. Methods This was a retrospective, interventional, nonsimultaneous study of 12 subjects (12 eyes) of mean age of 64.3 ± 18.3 years with OSD and apparent late-onset bleb leaks following trabeculectomy with mitomycin C between 1998 and 2008. We compared patients diagnosed with leakages before July 2005, who had been treated with separate eye drop solutions containing 0.1% sodium hyaluronate, 50% autologous serum, and 0.3% ofloxacin (sodium hyaluronate and autologous serum group, n = 7), with patients diagnosed from August 2005 to December 2008, who were treated with a combination of eye drops (0.1% sodium hyaluronate, 50% autologous serum, and 0.08% levofloxacin hydrate) and eyelid massage and warm compresses for obstructive meibomian gland dysfunction (combination eye drop group, n = 5). Results Leakage was resolved in one patient (14.3%) in the separately treated sodium hyaluronate and autologous serum eye drop group and in five patients (100%) in the combination eye drop group (P = 0.015). The period after resolution of leakage with conservative treatment was 23 months in the one eye in the sodium hyaluronate and autologous serum group and 36–61 (mean 52.4 ± 10.1) months in the five eyes in the combination eye drop group. Conclusion Late-onset bleb leaks following trabeculectomy with mitomycin C can be treated effectively using a combination of sodium hyaluronate and autologous serum eye drops, eyelid massage, and warm compresses. Furthermore, combining eye drops may improve patient adherence to the drug regimen

  13. The role of "blebbing" in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans

    USGS Publications Warehouse

    Knickerbocker, C.; Nordstrom, D.K.; Southam, G.

    2000-01-01

    Brimstone Basin, in southeastern Yellowstone National Park, Wyoming is an ancient hydrothermal area containing solfataric alteration. Drainage waters flowing from Brimstone Basin had pH values as low as 1.23 and contained up to 1.7×106 MPN/ml acidophilic sulfur-oxidizing bacteria. Thiobacillus thiooxidans was the dominant sulfur-oxidizing bacterium recovered from an enrichment culture and was used in a structural examination of bacterial sulfur oxidation. Growth in these sulfur cultures occurred in two phases with cells in association with the macroscopic sulfur grains and in suspension above these grains. Colonization of sulfur grains by individual cells and microcolonies was facilitated by organic material that appeared to be responsible for bacterial adhesion. Transmission electron microscopy of negatively stained (2% [wt./vol.] uranyl acetate), sulfur-grown T. thiooxidans revealed extensive membrane blebbing (sloughing of outer membrane vesicles) and the presence of approximately 100 nm sized sulfur particles adsorbed to membrane material surrounding individual bacteria. Sulfite-grown bacteria did not possess membrane blebs. The amphipathic nature of these outer membrane vesicles appear to be responsible for overcoming the hydrophobic barrier necessary for the growth of T. thiooxidans on elemental sulfur.

  14. Who Really Failed New Orleans?

    NASA Astrophysics Data System (ADS)

    Barrow, Thomas D.

    2008-09-01

    I read with unusual interest the Forum ``Earth Scientists and Public Policy: Have We Failed New Orleans?'' in the 4 March issue of Eos (89(10), 2008). As an Earth scientist who lived in New Orleans during most of the early 1960s, I believe strongly that Earth scientists did not fail to recognize infrastructure problems. Further, they tried to communicate these problems and potential dangers to civic leaders in New Orleans and to government officials in Baton Rouge and Washington.

  15. Disk filter

    DOEpatents

    Bergman, W.

    1985-01-09

    An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

  16. Disk filter

    DOEpatents

    Bergman, Werner

    1986-01-01

    An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

  17. Myotonic dystrophy protein kinase (DMPK) induces actin cytoskeletal reorganization and apoptotic-like blebbing in lens cells

    NASA Technical Reports Server (NTRS)

    Jin, S.; Shimizu, M.; Balasubramanyam, A.; Epstein, H. F.

    2000-01-01

    DMPK, the product of the DM locus, is a member of the same family of serine-threonine protein kinases as the Rho-associated enzymes. In DM, membrane inclusions accumulate in lens fiber cells producing cataracts. Overexpression of DMPK in cultured lens epithelial cells led to apoptotic-like blebbing of the plasma membrane and reorganization of the actin cytoskeleton. Enzymatically active DMPK was necessary for both effects; inactive mutant DMPK protein did not produce either effect. Active RhoA but not constitutive GDP-state mutant protein produced similar effects as DMPK. The similar actions of DMPK and RhoA suggest that they may function in the same regulatory network. The observed effects of DMPK may be relevant to the removal of membrane organelles during normal lens differentiation and the retention of intracellular membranes in DM lenses. Copyright 2000 Wiley-Liss, Inc.

  18. Overexpression of the Tomato Pollen Receptor Kinase LePRK1 Rewires Pollen Tube Growth to a Blebbing Mode[W][OPEN

    PubMed Central

    Gui, Cai-Ping; Dong, Xin; Liu, Hai-Kuan; Huang, Wei-Jie; Zhang, Dong; Wang, Shu-Jie; Barberini, María Laura; Gao, Xiao-Yan; Muschietti, Jorge; McCormick, Sheila

    2014-01-01

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP), a Rop guanine nucleotide exchange factor. Here, we show that pollen tubes overexpressing LePRK1 or a truncated LePRK1 lacking its extracellular domain (LePRK1ΔECD) have enlarged tips but also extend their leading edges by producing “blebs.” Coexpression of LePRK1 and tomato PLIM2a, an actin bundling protein that interacts with KPP in a Ca2+-responsive manner, suppressed these LePRK1 overexpression phenotypes, whereas pollen tubes coexpressing KPP, LePRK1, and PLIM2a resumed the blebbing growth mode. We conclude that overexpression of LePRK1 or LePRK1ΔECD rewires pollen tube growth to a blebbing mode, through KPP- and PLIM2a-mediated bundling of actin filaments from tip plasma membranes. Arabidopsis thaliana pollen tubes expressing LePRK1ΔECD also grew by blebbing. Our results exposed a hidden capability of the pollen tube cell: upon overexpression of a single membrane-localized molecule, LePRK1 or LePRK1ΔECD, it can switch to an alternative mechanism for extension of the leading edge that is analogous to the blebbing growth mode reported for Dictyostelium and for Drosophila melanogaster stem cells. PMID:25194029

  19. Water Filters

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Aquaspace H2OME Guardian Water Filter, available through Western Water International, Inc., reduces lead in water supplies. The filter is mounted on the faucet and the filter cartridge is placed in the "dead space" between sink and wall. This filter is one of several new filtration devices using the Aquaspace compound filter media, which combines company developed and NASA technology. Aquaspace filters are used in industrial, commercial, residential, and recreational environments as well as by developing nations where water is highly contaminated.

  20. Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries

    PubMed Central

    Masoumpour, Masoumeh B.; Nowroozzadeh, M. Hossein; Razeghinejad, M. Reza

    2016-01-01

    Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries. PMID:27014389

  1. Biological Filters.

    ERIC Educational Resources Information Center

    Klemetson, S. L.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. The review is concerned with biological filters, and it covers: (1) trickling filters; (2) rotating biological contractors; and (3) miscellaneous reactors. A list of 14 references is also presented. (HM)

  2. FILTER TREATMENT

    DOEpatents

    Sutton, J.B.; Torrey, J.V.P.

    1958-08-26

    A process is described for reconditioning fused alumina filters which have become clogged by the accretion of bismuth phosphate in the filter pores, The method consists in contacting such filters with faming sulfuric acid, and maintaining such contact for a substantial period of time.

  3. Water Filters

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A compact, lightweight electrolytic water filter generates silver ions in concentrations of 50 to 100 parts per billion in the water flow system. Silver ions serve as effective bactericide/deodorizers. Ray Ward requested and received from NASA a technical information package on the Shuttle filter, and used it as basis for his own initial development, a home use filter.

  4. The Child Who is Failing

    ERIC Educational Resources Information Center

    Yule, Valerie

    1974-01-01

    Provides case studies of Australian children who fail for social reasons. The role of social factors operating within the schools is stressed along with the lost curriculum. That factors operating in school failure are in fact social problems is suggested. [Available from Publications Branch, Education Department of Victoria, 234 Queensberry…

  5. Segmented Coil Fails In Steps

    NASA Technical Reports Server (NTRS)

    Stedman, Ronald S.

    1990-01-01

    Electromagnetic coil degrades in steps when faults occur, continues to operate at reduced level instead of failing catastrophically. Made in segments connected in series and separated by electrically insulating barriers. Fault does not damage adjacent components or create hazard. Used to control valves in such critical applications as cooling systems of power generators and chemical process equipment, where flammable liquids or gases handled. Also adapts to electrical control of motors.

  6. Bioenergetics of the failing heart.

    PubMed

    Ventura-Clapier, Renée; Garnier, Anne; Veksler, Vladimir; Joubert, Frédéric

    2011-07-01

    The heart is responsible for pumping blood throughout the blood vessels to the periphery by repeated, rhythmic contractions at variable intensity. As such the heart should permanently adjust energy production to energy utilization and is a high-energy consumer. For this the heart mainly depends on oxidative metabolism for adequate energy production and on efficient energy transfer systems. In heart failure, there is disequilibrium between the work the heart has to perform and the energy it is able to produce to fulfill its needs. This has led to the concept of energy starvation of the failing heart. This includes decreased oxygen and substrate supply, altered substrate utilization, decreased energy production by mitochondria and glycolysis, altered energy transfer and inefficient energy utilization. Mitochondrial biogenesis and its transcription cascade are down-regulated. Disorganization of the cytoarchitecture of the failing cardiomyocyte also participates in energy wastage. Finally, the failing of the cardiac pump, by decreasing oxygen and substrate supply, leads to a systemic energy starvation. Metabolic therapy has thus emerged as an original and promising approach in the treatment heart failure. This article is part of a Special Issue entitled: Mitochondria and Cardioprotection. PMID:20869993

  7. Filtering apparatus

    DOEpatents

    Haldipur, G.B.; Dilmore, W.J.

    1992-09-01

    A vertical vessel is described having a lower inlet and an upper outlet enclosure separated by a main horizontal tube sheet. The inlet enclosure receives the flue gas from a boiler of a power system and the outlet enclosure supplies cleaned gas to the turbines. The inlet enclosure contains a plurality of particulate-removing clusters, each having a plurality of filter units. Each filter unit includes a filter clean-gas chamber defined by a plate and a perforated auxiliary tube sheet with filter tubes suspended from each tube sheet and a tube connected to each chamber for passing cleaned gas to the outlet enclosure. The clusters are suspended from the main tube sheet with their filter units extending vertically and the filter tubes passing through the tube sheet and opening in the outlet enclosure. The flue gas is circulated about the outside surfaces of the filter tubes and the particulate is absorbed in the pores of the filter tubes. Pulses to clean the filter tubes are passed through their inner holes through tubes free of bends which are aligned with the tubes that pass the clean gas. 18 figs.

  8. Filtering apparatus

    DOEpatents

    Haldipur, Gaurang B.; Dilmore, William J.

    1992-01-01

    A vertical vessel having a lower inlet and an upper outlet enclosure separated by a main horizontal tube sheet. The inlet enclosure receives the flue gas from a boiler of a power system and the outlet enclosure supplies cleaned gas to the turbines. The inlet enclosure contains a plurality of particulate-removing clusters, each having a plurality of filter units. Each filter unit includes a filter clean-gas chamber defined by a plate and a perforated auxiliary tube sheet with filter tubes suspended from each tube sheet and a tube connected to each chamber for passing cleaned gas to the outlet enclosure. The clusters are suspended from the main tube sheet with their filter units extending vertically and the filter tubes passing through the tube sheet and opening in the outlet enclosure. The flue gas is circulated about the outside surfaces of the filter tubes and the particulate is absorbed in the pores of the filter tubes. Pulses to clean the filter tubes are passed through their inner holes through tubes free of bends which are aligned with the tubes that pass the clean gas.

  9. Charcoal filter testing

    SciTech Connect

    Lyons, J.

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  10. Filter holder assembly having extended collar spacer ring

    DOEpatents

    Alvin, Mary Anne; Bruck, Gerald J.

    2002-01-01

    A filter holder assembly is provided that utilizes a fail-safe regenerator unit with an annular spacer ring having an extended metal collar for containment and positioning of a compliant ceramic gasket used in the assembly. The filter holder assembly is disclosed for use with advanced composite, filament wound, and metal candle filters.

  11. Why good projects fail anyway.

    PubMed

    Matta, Nadim F; Ashkenas, Ronald N

    2003-09-01

    Big projects fail at an astonishing rate--more than half the time, by some estimates. It's not hard to understand why. Complicated long-term projects are customarily developed by a series of teams working along parallel tracks. If managers fail to anticipate everything that might fall through the cracks, those tracks will not converge successfully at the end to reach the goal. Take a companywide CRM project. Traditionally, one team might analyze customers, another select the software, a third develop training programs, and so forth. When the project's finally complete, though, it may turn out that the salespeople won't enter in the requisite data because they don't understand why they need to. This very problem has, in fact, derailed many CRM programs at major organizations. There is a way to uncover unanticipated problems while the project is still in development. The key is to inject into the overall plan a series of miniprojects, or "rapid-results initiatives," which each have as their goal a miniature version of the overall goal. In the CRM project, a single team might be charged with increasing the revenues of one sales group in one region by 25% within four months. To reach that goal, team members would have to draw on the work of all the parallel teams. But in just four months, they would discover the salespeople's resistance and probably other unforeseen issues, such as, perhaps, the need to divvy up commissions for joint-selling efforts. The World Bank has used rapid-results initiatives to great effect to keep a sweeping 16-year project on track and deliver visible results years ahead of schedule. In taking an in-depth look at this project, and others, the authors show why this approach is so effective and how the initiatives are managed in conjunction with more traditional project activities.

  12. A new approach to blue rubber bleb nevus syndrome: the role of capsule endoscopy and intra-operative enteroscopy.

    PubMed

    Kopácová, Marcela; Tachecí, Ilja; Koudelka, Jaroslav; Králová, Miroslava; Rejchrt, Stanislav; Bures, Jan

    2007-07-01

    Blue rubber bleb nevus syndrome (BRBNS) is a rare vascular malformation disorder with cutaneous and visceral lesions frequently associated with serious, even fatal bleeding and anemia. The syndrome is considered to be autosomaly predominantly inherited. Intra-operative enteroscopy (IOE) is the best method of identification of all lesions (particularly the small ones, less than 3 mm) and treatment by endoscopic electro-coagulation or surgical excision. Capsule wireless endoscopy is optimal for screening before the IOE and for monitoring the effect of therapy (in patients with BRBNS). We report two cases of BRBNS. Anemia, gastrointestinal bleeding, gastrointestinal malformations and multifocal venous malformations of the skin were present in both of our cases. Gastrointestinal lesions were identified by gastroscopy, colonoscopy and capsule endoscopy. The multiple venous malformations were treated partly by endoscopic electro-coagulation (lesions up to 4 mm in diameter) and by wedge resection. Both of our patients were 12-year-old girls at the time of operation. In the first patient 31 venous malformations of the small bowel were coagulated, two were resected by the surgeon. In the second patient 20 lesions were coagulated endoscopically and another 31 nevi were resected during an 8 h procedure. The first girl is doing fine 4 years after the procedure, the second was allowed home 2 weeks after the procedure in excellent condition. IOE is a unique method of small bowel investigation and concurrently provides a solution for pathological findings. Capsule endoscopy is a feasible non-invasive screening procedure. We believe that a radical eliminatory approach by means of combined surgery and IOE is indicated for the BRBNS to prevent ongoing gastrointestinal bleeding. PMID:17205297

  13. A new approach to blue rubber bleb nevus syndrome: the role of capsule endoscopy and intra-operative enteroscopy.

    PubMed

    Kopácová, Marcela; Tachecí, Ilja; Koudelka, Jaroslav; Králová, Miroslava; Rejchrt, Stanislav; Bures, Jan

    2007-07-01

    Blue rubber bleb nevus syndrome (BRBNS) is a rare vascular malformation disorder with cutaneous and visceral lesions frequently associated with serious, even fatal bleeding and anemia. The syndrome is considered to be autosomaly predominantly inherited. Intra-operative enteroscopy (IOE) is the best method of identification of all lesions (particularly the small ones, less than 3 mm) and treatment by endoscopic electro-coagulation or surgical excision. Capsule wireless endoscopy is optimal for screening before the IOE and for monitoring the effect of therapy (in patients with BRBNS). We report two cases of BRBNS. Anemia, gastrointestinal bleeding, gastrointestinal malformations and multifocal venous malformations of the skin were present in both of our cases. Gastrointestinal lesions were identified by gastroscopy, colonoscopy and capsule endoscopy. The multiple venous malformations were treated partly by endoscopic electro-coagulation (lesions up to 4 mm in diameter) and by wedge resection. Both of our patients were 12-year-old girls at the time of operation. In the first patient 31 venous malformations of the small bowel were coagulated, two were resected by the surgeon. In the second patient 20 lesions were coagulated endoscopically and another 31 nevi were resected during an 8 h procedure. The first girl is doing fine 4 years after the procedure, the second was allowed home 2 weeks after the procedure in excellent condition. IOE is a unique method of small bowel investigation and concurrently provides a solution for pathological findings. Capsule endoscopy is a feasible non-invasive screening procedure. We believe that a radical eliminatory approach by means of combined surgery and IOE is indicated for the BRBNS to prevent ongoing gastrointestinal bleeding.

  14. Initial Failure Analysis of Ceramic Filters

    SciTech Connect

    Huque, Z.; Mei, D.; Zhou, J.

    1996-12-31

    Effective high temperature ceramic filters are indispensable in the advanced, coal based power systems (IGCC and PFBC). To meet the environmental particulate emission requirements and improve thermal efficiency, ceramic filters are utilized to cleanup the hot gas particulate to protect downstream heat exchanger and gas turbine components from fouling and corrosion. The mechanical integrity of ceramic filters and an efficient dust cake removal system are the key issues for hot gas cleanup systems. The filters must survive combined stresses due to mechanical, thermal, chemical and steam attack throughout normal operations (cold back pulse cleaning jets), unexpected excessive ash accumulation, and the start up and shut down conditions. To evaluate the design and performance of ceramic filters, different long term filter testing programs were conducted. To fulfill this purpose, two Advanced Particle Filter (APF) systems were complete at Tidd PFBC Demonstration Plant in Brilliant, Ohio in late 1990 as part of the Department of Energy`s (DOE) Clean Coal Technology Program. However, many filter failures 1649 were reported prior to its desired life time. In Tidd APF vessel, 28 filters failed one time, The objectives of this program were to provide an understanding of the factors pertinent to the failures of ceramic filters by characterizing filter properties and the dust cake removal mechanism, Researches were emphasized on understanding of changes of filter properties and back pulse cleaning mechanism to resolve the issues relating to filter permeability variations, ash bridging and micro-thermal cracks induced during cold back pulse cleaning. To perform failure analysis of ceramic filters, thermal numerical simulation, material laboratory analysis on filter materials and dust cake, and measurements on filter properties and back pulse intensity along filter axis within a bench scale filter chamber were conducted.

  15. Electrocardiogram of the failing heart.

    PubMed

    Hombach, Vinzenz

    2002-09-01

    In the failing heart general specific (e.g., Q-waves after acute myocardial infarction, persistent ST-elevations in post-myocardial infarction left ventricular aneurysm) and unspecific ECG changes (e.g., left bundle branch block, right bundle branch block, ST-T-alterations due to digitalis glycosides or antiarrhythmic drugs) may be seen in the conventional 12-lead ECG. In addition, atrial and ventricular tachy-arrhythmias may be detected and quantified by 24-hour-Holter ECG recordings, that may be relevant for a worse prognosis of patients with congestive heart failure. Heart rate variability as the most relevant derived ECG parameter of sympathetic tone fluctuations may be of important prognostic significance in congestive heart failure patients. An abnormal signal averaged P-wave duration may predict the incidence of atrial fibrillation, as may apply to QRS-prolongation and/or ventricular late potentials in the signal averaged ECG for the incidence of serious life-threatening ventricular tachy-arrhythmias or death from pump failure. Last but not least, cardiac repolarization abnormalities may be detected by QT dispersion-, QT-/QTc-fluctuation- or T-wave alternans studies, but the true prognostic significance of these parameters for predicting sudden cardiac death or death from pump failure in patients with congestive heart failure remains unclear. PMID:12114840

  16. Filter apparatus

    DOEpatents

    Kuban, D.P.; Singletary, B.H.; Evans, J.H.

    A plurality of holding tubes are respectively mounted in apertures in a partition plate fixed in a housing receiving gas contaminated with particulate material. A filter cartridge is removably held in each holding tube, and the cartridges and holding tubes are arranged so that gas passes through apertures therein and across the the partition plate while particulate material is collected in the cartridges. Replacement filter cartridges are respectively held in holding canisters mounted on a support plate which can be secured to the aforesaid housing, and screws mounted on said canisters are arranged to push replacement cartridges into the cartridge holding tubes and thereby eject used cartridges therefrom.

  17. Water Filters

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Seeking to find a more effective method of filtering potable water that was highly contaminated, Mike Pedersen, founder of Western Water International, learned that NASA had conducted extensive research in methods of purifying water on board manned spacecraft. The key is Aquaspace Compound, a proprietary WWI formula that scientifically blends various types of glandular activated charcoal with other active and inert ingredients. Aquaspace systems remove some substances; chlorine, by atomic adsorption, other types of organic chemicals by mechanical filtration and still others by catalytic reaction. Aquaspace filters are finding wide acceptance in industrial, commercial, residential and recreational applications in the U.S. and abroad.

  18. Extracting tissue deformation using Gabor filter banks

    NASA Astrophysics Data System (ADS)

    Montillo, Albert; Metaxas, Dimitris; Axel, Leon

    2004-04-01

    This paper presents a new approach for accurate extraction of tissue deformation imaged with tagged MR. Our method, based on banks of Gabor filters, adjusts (1) the aspect and (2) orientation of the filter"s envelope and adjusts (3) the radial frequency and (4) angle of the filter"s sinusoidal grating to extract information about the deformation of tissue. The method accurately extracts tag line spacing, orientation, displacement and effective contrast. Existing, non-adaptive methods often fail to recover useful displacement information in the proximity of tissue boundaries while our method works in the proximity of the boundaries. We also present an interpolation method to recover all tag information at a finer resolution than the filter bank parameters. Results are shown on simulated images of translating and contracting tissue.

  19. Notch filter

    NASA Technical Reports Server (NTRS)

    Shelton, G. B. (Inventor)

    1977-01-01

    A notch filter for the selective attenuation of a narrow band of frequencies out of a larger band was developed. A helical resonator is connected to an input circuit and an output circuit through discrete and equal capacitors, and a resistor is connected between the input and the output circuits.

  20. Multilayer waveguide-grating filters.

    PubMed

    Wang, S S; Magnusson, R

    1995-05-10

    The properties of guided-mode resonance reflection filters constructed with multiple thin-film layers are addressed. Greatly improved filter characteristics are shown to follow by the incorporation of multiple homogeneous layers with the spatially modulated layer. Calculated results for single-layer, double-layer, and triple-layer filter structures are presented. Whereas good filter characteristics are obtainable with single layers that are half-resonance-wavelength thick, there remains a residual reflection in the sidebands unless the cover and the substrate permittivities are equal. With double-layer and triple-layer designs, extensive wavelength ranges with low sideband-reflectance values are shown to be possible without requiring equal cover and substrate permittivities. The antireflection properties of the layer stack can be understood if the modulated layer is modeled as a homogeneous layer characterized by its average relative permittivity. However, as the grating-modulation index increases, this approximation deteriorates. In particular it is found that, for a given high modulation index, the double-layer antireflection thin-film approximation fails, whereas for the same modulation in a triple-layer system it holds firmly. Multilayer designs can thus have significantly large filter passbands, as they may contain heavily modulated resonant gratings without corruption of the ideal filter characteristics.

  1. Compositions of Magmatic and Impact Melt Sulfides in Tissint And EETA79001: Precursors of Immiscible Sulfide Melt Blebs in Shergottite Impact Melts

    NASA Technical Reports Server (NTRS)

    Ross, D. K.; Rao, M. N.; Nyquist, L.; Agee, C.; Sutton, S.

    2013-01-01

    Immiscible sulfide melt spherules are locally very abundant in shergottite impact melts. These melts can also contain samples of Martian atmospheric gases [1], and cosmogenic nuclides [2] that are present in impact melt, but not in the host shergottite, indicating some components in the melt resided at the Martian surface. These observations show that some regolith components are, at least locally, present in the impact melts. This view also suggests that one source of the over-abundant sulfur in these impact melts could be sulfates that are major constituents of Martian regolith, and that the sulfates were reduced during shock heating to sulfide. An alternative view is that sulfide spherules in impact melts are produced solely by melting the crystalline sulfide minerals (dominantly pyrrhotite, Fe(1-x)S) that are present in shergottites [3]. In this abstract we report new analyses of the compositions of sulfide immiscible melt spherules and pyrrhotite in the shergottites Tissint, and EETA79001,507, and we use these data to investigate the possible origins of the immiscible sulfide melt spherules. In particular, we use the metal/S ratios determined in these blebs as potential diagnostic criteria for tracking the source material from which the numerous sulfide blebs were generated by shock in these melts.

  2. Is journalism failing on climate?

    NASA Astrophysics Data System (ADS)

    Rahmstorf, Stefan

    2012-12-01

    How can we build a reliable and affordable energy supply based on renewables? How rapidly do we need to cut greenhouse gas emissions to keep climate change within manageable bounds? What does it take to maintain a stable common currency of different nations? These are just a few examples of questions that are critical for our future and that require an understanding of complex systems—the energy system, the climate system, the financial system. Finding sound answers to these questions requires sophisticated scientific analysis and expert knowledge; a lay person's intuition will clearly not suffice. Yet, decisions in a democracy are (and should be!) taken by politicians and the voting public who are not usually scientific experts. Hence the well-being of our societies—and even more so the living conditions of future generations, which are defined by the decisions we take today—depends on the wider public being well informed about the state of scientific knowledge and discourse. The media are the most important means by which lay people obtain their information about science. Good science journalism is therefore a decisive factor for the long-term success of modern society. Good science journalism clearly must be critical journalism, and it requires journalists who know what is what, who can put things into a perspective, and who are able to make well-informed judgements. After all, the role of science journalism is not simply to act as a 'translator' who conveys the findings of scientists in a language understandable to lay people. Rather, good science journalism will provide the public with a realistic impression of what is well established in science and what are current 'hot topics', uncertainties and controversies. It will also discuss the methods and social context of the scientific endeavour. There is ample evidence that in the area of climate science, journalism too often is failing to deliver this realistic picture to its audience, despite many good

  3. Plasmonic filters.

    SciTech Connect

    Passmore, Brandon Scott; Shaner, Eric Arthur; Barrick, Todd A.

    2009-09-01

    Metal films perforated with subwavelength hole arrays have been show to demonstrate an effect known as Extraordinary Transmission (EOT). In EOT devices, optical transmission passbands arise that can have up to 90% transmission and a bandwidth that is only a few percent of the designed center wavelength. By placing a tunable dielectric in proximity to the EOT mesh, one can tune the center frequency of the passband. We have demonstrated over 1 micron of passive tuning in structures designed for an 11 micron center wavelength. If a suitable midwave (3-5 micron) tunable dielectric (perhaps BaTiO{sub 3}) were integrated with an EOT mesh designed for midwave operation, it is possible that a fast, voltage tunable, low temperature filter solution could be demonstrated with a several hundred nanometer passband. Such an element could, for example, replace certain components in a filter wheel solution.

  4. Water Filter

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A compact, lightweight electrolytic water sterilizer available through Ambassador Marketing, generates silver ions in concentrations of 50 to 100 parts per billion in water flow system. The silver ions serve as an effective bactericide/deodorizer. Tap water passes through filtering element of silver that has been chemically plated onto activated carbon. The silver inhibits bacterial growth and the activated carbon removes objectionable tastes and odors caused by addition of chlorine and other chemicals in municipal water supply. The three models available are a kitchen unit, a "Tourister" unit for portable use while traveling and a refrigerator unit that attaches to the ice cube water line. A filter will treat 5,000 to 10,000 gallons of water.

  5. Eyeglass Filters

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Biomedical Optical Company of America's suntiger lenses eliminate more than 99% of harmful light wavelengths. NASA derived lenses make scenes more vivid in color and also increase the wearer's visual acuity. Distant objects, even on hazy days, appear crisp and clear; mountains seem closer, glare is greatly reduced, clouds stand out. Daytime use protects the retina from bleaching in bright light, thus improving night vision. Filtering helps prevent a variety of eye disorders, in particular cataracts and age related macular degeneration.

  6. 40 CFR 141.561 - What happens if my system's turbidity monitoring equipment fails?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false What happens if my system's turbidity... Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.561 What happens if my system's turbidity monitoring equipment fails? If there is a failure in the...

  7. 40 CFR 141.561 - What happens if my system's turbidity monitoring equipment fails?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false What happens if my system's turbidity... Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.561 What happens if my system's turbidity monitoring equipment fails? If there is a failure in the...

  8. 40 CFR 141.561 - What happens if my system's turbidity monitoring equipment fails?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false What happens if my system's turbidity... Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.561 What happens if my system's turbidity monitoring equipment fails? If there is a failure in the...

  9. 40 CFR 141.561 - What happens if my system's turbidity monitoring equipment fails?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false What happens if my system's turbidity... Disinfection-Systems Serving Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.561 What happens if my system's turbidity monitoring equipment fails? If there is a failure in the...

  10. A fail-safe CMOS logic gate

    NASA Technical Reports Server (NTRS)

    Bobin, V.; Whitaker, S.

    1990-01-01

    This paper reports a design technique to make Complex CMOS Gates fail-safe for a class of faults. Two classes of faults are defined. The fail-safe design presented has limited fault-tolerance capability. Multiple faults are also covered.

  11. Is journalism failing on climate?

    NASA Astrophysics Data System (ADS)

    Rahmstorf, Stefan

    2012-12-01

    How can we build a reliable and affordable energy supply based on renewables? How rapidly do we need to cut greenhouse gas emissions to keep climate change within manageable bounds? What does it take to maintain a stable common currency of different nations? These are just a few examples of questions that are critical for our future and that require an understanding of complex systems—the energy system, the climate system, the financial system. Finding sound answers to these questions requires sophisticated scientific analysis and expert knowledge; a lay person's intuition will clearly not suffice. Yet, decisions in a democracy are (and should be!) taken by politicians and the voting public who are not usually scientific experts. Hence the well-being of our societies—and even more so the living conditions of future generations, which are defined by the decisions we take today—depends on the wider public being well informed about the state of scientific knowledge and discourse. The media are the most important means by which lay people obtain their information about science. Good science journalism is therefore a decisive factor for the long-term success of modern society. Good science journalism clearly must be critical journalism, and it requires journalists who know what is what, who can put things into a perspective, and who are able to make well-informed judgements. After all, the role of science journalism is not simply to act as a 'translator' who conveys the findings of scientists in a language understandable to lay people. Rather, good science journalism will provide the public with a realistic impression of what is well established in science and what are current 'hot topics', uncertainties and controversies. It will also discuss the methods and social context of the scientific endeavour. There is ample evidence that in the area of climate science, journalism too often is failing to deliver this realistic picture to its audience, despite many good

  12. Ceramic filters

    SciTech Connect

    Holmes, B.L.; Janney, M.A.

    1995-12-31

    Filters were formed from ceramic fibers, organic fibers, and a ceramic bond phase using a papermaking technique. The distribution of particulate ceramic bond phase was determined using a model silicon carbide system. As the ceramic fiber increased in length and diameter the distance between particles decreased. The calculated number of particles per area showed good agreement with the observed value. After firing, the papers were characterized using a biaxial load test. The strength of papers was proportional to the amount of bond phase included in the paper. All samples exhibited strain-tolerant behavior.

  13. Surgical Treatment of Canine Glaucoma: Filtering and End-Stage Glaucoma Procedures.

    PubMed

    Maggio, Federica; Bras, Dineli

    2015-11-01

    Canine glaucoma is a common cause of vision loss associated with raised intraocular pressure, and leads to damage of the retina and optic nerve head. In most cases, medical treatment alone cannot provide long-term management of intraocular pressure control and preservation of vision. Surgical intervention is usually recommended to either decrease aqueous humor production, or increase its outflow. Among the current available procedures, filtering techniques are aimed at increasing aqueous humor outflow. Proper surgical timing and a combination of cyclodestructive and filtering procedures have been recently suggested to improve the long-term success of surgical treatment in dogs. Bleb fibrosis and surgical failure are still common occurrences in filtration surgery with relapse of glaucoma and vision loss. End stage procedures, such as enucleation, evisceration with intrascleral prosthesis, and chemical ablation of the ciliary bodies are then recommended to address chronic discomfort in buphthalmic and blind eyes.

  14. Photopheresis with UV-A light and 8-methoxypsoralen leads to cell death and to release of blebs with anti-inflammatory phenotype in activated and non-activated lymphocytes

    SciTech Connect

    Stadler, K.; Frey, B.; Munoz, L.E.; Finzel, S.; Rech, J.; Fietkau, R.; Herrmann, M.; Hueber, A.; Gaipl, U.S.

    2009-08-14

    Background: Extracorporeal photopheresis is a therapy for treatment of autoimmune diseases, cutaneous T-cell lymphoma, organ graft rejection as well as graft-versus-host diseases. The exact mechanism how the combination of 8-methoxypsoralen plus UV-A irradiation (PUVA) acts is still unclear. We investigated the cell death of activated and non-activated lymphocytes after PUVA treatment as well as the rate of released blebs and their antigen composition. Results: In presence of 8-MOP, UV-A light highly significantly increased the cell death of activated lymphocytes. The same was observed to a lesser extent in non-activated cells. Blebs derived from activated lymphocytes after PUVA treatment showed the highest surface exposition of phosphatidylserine. These blebs also displayed a high exposure of the antigens CD5 and CD8 as well as a low exposure of CD28 and CD86. Conclusion: PUVA treatment exerts anti-inflammatory effects by inducing apoptosis and apoptotic cell-derived blebs with immune suppressive surface composition.

  15. Rocket noise filtering system using digital filters

    NASA Technical Reports Server (NTRS)

    Mauritzen, David

    1990-01-01

    A set of digital filters is designed to filter rocket noise to various bandwidths. The filters are designed to have constant group delay and are implemented in software on a general purpose computer. The Parks-McClellan algorithm is used. Preliminary tests are performed to verify the design and implementation. An analog filter which was previously employed is also simulated.

  16. In-place filter testing summary

    SciTech Connect

    Ortiz, J.P.; Garcia, E.D.; Ortega, J.M.

    1988-03-01

    The most common method of identifying particle penetration through a filter or adsorber system is through the performance of a periodic penetration test, i.e., in-place test or leak test using an aerosol or gas vapor to challenge the filter or adsorber system. The aerosol is usually formed by vaporization of a liquid, di-2(ethelhexyl sebacate) (DEHS), and allowed to condense to form liquid particles of a certain size and distribution. The gas vapor is formed by vaporization of Freon 11 liquid. The periodic penetration test, although conducted annually, can and has been demonstrated to show the beginning degradation of a filter or adsorber system. Other evidence of penetration can include detection of radiation downstream of the filter system or the existence of an unusually low pressure drop across the filter, i.e., torn filter, etc. However, these kinds of occurrences show up instantaneously and could release radioactive material to the atmosphere before the systems could be shut down. When a filter system fails the in--place test or is showing evidence of.filter or component degradation, corrective measures are put into place in order to return,the system back to its best operating condition. This report presents a summary of all filter tests.

  17. The high efficiency steel filters for nuclear air cleaning

    SciTech Connect

    Bergman, W.; Larsen, G.; Lopez, R.; Williams, K.; Violet, C.

    1990-08-01

    We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs.

  18. Assessment of filter dust characteristics that cause filter failure during hot-gas filtration

    SciTech Connect

    John P. Hurley; Biplab Mukherjee; Michael D. Mann

    2006-08-15

    The high-temperature filtration of particulates from gases is greatly limited because of the development of dust cakes that are difficult to remove and can bridge between candle filters, causing them to break. Understanding the conditions leading to the formation of cohesive dust can prevent costly filter failures and ensure higher efficiency of solid fuel, direct-fired turbine power generation systems. The University of North Dakota Energy & Environmental Research Center is working with the New Energy and Industrial Technology Development Organization and the U.S. Department of Energy to perform research to characterize and determine the factors that cause the development of such dust cakes. Changes in the tensile strength, bridging propensity, and plasticity of filter dust cakes were measured as a function of the temperature and a filter pressure drop for a coal and a biomass filter dust. The biomass filter dust indicated that potential filtering problems can exist at temperatures as low as 400{sup o}C, while the coal filter dust showed good filtering characteristics up to 750{sup o}C. A statistically valid model that can indicate the propensity of filters to fail with system operating conditions was developed. A detailed analysis of the chemical aspect of dusts is also presented in order to explore the causes of such stickiness. 16 refs., 10 figs., 3 tabs.

  19. HEPA Filter Performance under Adverse Conditions

    SciTech Connect

    Parsons, Michael; Hogancamp, Kristina; Alderman, Steven; Waggoner, Charles

    2007-07-01

    This study involved challenging nuclear grade high-efficiency particulate air (HEPA) filters under a variety of conditions that can arise in Department of Energy (DOE) applications such as: low or high RH, controlled and uncontrolled challenge, and filters with physically damaged media or seals (i.e., leaks). Reported findings correlate filter function as measured by traditional differential pressure techniques in comparison with simultaneous instrumental determination of up and down stream PM concentrations. Additionally, emission rates and failure signatures will be discussed for filters that have either failed or exceeded their usable lifetime. Significant findings from this effort include the use of thermocouples up and down stream of the filter housing to detect the presence of moisture. Also demonstrated in the moisture challenge series of tests is the effect of repeated wetting of the filter. This produces a phenomenon referred to as transient failure before the tensile strength of the media weakens to the point of physical failure. An evaluation of the effect of particle size distribution of the challenge aerosol on loading capacity of filters is also included. Results for soot and two size distributions of KCl are reported. Loading capacities for filters ranged from approximately 70 g of soot to nearly 900 g for the larger particle size distribution of KCl. (authors)

  20. How to Recognize a Failed Burn Resuscitation.

    PubMed

    Brownson, Elisha G; Pham, Tam N; Chung, Kevin K

    2016-10-01

    Failed burn resuscitation can occur at various points. Early failed resuscitation will be largely caused by prehospital factors. During resuscitation, failure will present as a patient's nonresponse to adjunctive therapy. Late failure will occur in the setting of multiple organ dysfunction syndrome. Burn care providers must be vigilant during the resuscitation to identify a threatened resuscitation so that adjunctive therapies or rescue maneuvers can be used to convert to a successful resuscitation. However, when a patient's resuscitative course becomes unsalvageable, transition to comfort care should be taken to avoid prolongation of suffering. PMID:27600128

  1. Miniaturized dielectric waveguide filters

    NASA Astrophysics Data System (ADS)

    Sandhu, Muhammad Y.; Hunter, Ian C.

    2016-10-01

    Design techniques for a new class of integrated monolithic high-permittivity ceramic waveguide filters are presented. These filters enable a size reduction of 50% compared to air-filled transverse electromagnetic filters with the same unloaded Q-factor. Designs for Chebyshev and asymmetric generalised Chebyshev filter and a diplexer are presented with experimental results for an 1800 MHz Chebyshev filter and a 1700 MHz generalised Chebyshev filter showing excellent agreement with theory.

  2. Preliminary studies to determine the shelf life of HEPA filters

    SciTech Connect

    Gilbert, H.; Fretthold, J.K.; Rainer, F.; Bergman, W.; Beason, D.

    1994-07-18

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blowout. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  3. Preliminary studies to determine the shelf life of HEPA filters

    SciTech Connect

    Gilbert, H.; Fretthold, J.K.; Rainer, F.

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  4. Examination of a Failed Professional Learning Community

    ERIC Educational Resources Information Center

    Sims, Rachel L.; Penny, G. Richard

    2015-01-01

    Schools are using various forms of professional learning communities (PLCs) in order to increase student achievement and improve educational practices through enhanced communication and collaboration among teachers. This study examined a PLC that had too narrow a focus and failed therefore to affect student achievement. A critical shortcoming of…

  5. Failed Citizenship, Civic Engagement, and Education

    ERIC Educational Resources Information Center

    Banks, James A.

    2015-01-01

    Many racial, ethnic, cultural, linguistic, and religious groups are denied structural inclusion into their nation-state. Consequently, they do not internalize the values and symbols of the nation-state, develop a strong identity with it, or acquire political efficacy. The author conceptualizes this process as "failed citizenship,"…

  6. Contested Spaces of a "Failing" Elementary School

    ERIC Educational Resources Information Center

    Kawai, Roi; Serriere, Stephanie; Mitra, Dana

    2014-01-01

    Amid the recent proliferation of teacher-led movements resisting high-stakes testing across the United States, the authors identify how a "failing" elementary school reclaimed local discourse by taking political action against top-down measures. Framed as competing modes of school reform, the authors offer the sociocultural framework of…

  7. Understanding Failing Schools: Perspectives from the Inside

    ERIC Educational Resources Information Center

    Nicolaidou, Maria; Ainscow, Mel

    2005-01-01

    This paper analyses the experience of so-called "failing schools" in order to develop understandings that can inform improvement efforts. It reports on a study of the experiences of a small number of English primary schools placed in "special measures" as a result of being inspected. The study is unusual in that, in the past, researchers have…

  8. The Art of Saving a Failing School

    ERIC Educational Resources Information Center

    Stein, Les

    2012-01-01

    While the debate continues over whether to close failing schools or attempt fixing them, the author asserts that the solution most often lies in assigning strong leaders to them who will take definite and immediate action. Reviewing his own success turning around schools, he says creating a sense of urgency, unloading poor performing staff, and…

  9. HEPA filter dissolution process

    DOEpatents

    Brewer, K.N.; Murphy, J.A.

    1994-02-22

    A process is described for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal. 4 figures.

  10. Hepa filter dissolution process

    DOEpatents

    Brewer, Ken N.; Murphy, James A.

    1994-01-01

    A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

  11. Recirculating electric air filter

    DOEpatents

    Bergman, W.

    1985-01-09

    An electric air filter cartridge has a cylindrical inner high voltage electrode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  12. Recirculating electric air filter

    DOEpatents

    Bergman, Werner

    1986-01-01

    An electric air filter cartridge has a cylindrical inner high voltage eleode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  13. Evaluating low pass filters on SPECT reconstructed cardiac orientation estimation

    NASA Astrophysics Data System (ADS)

    Dwivedi, Shekhar

    2009-02-01

    Low pass filters can affect the quality of clinical SPECT images by smoothing. Appropriate filter and parameter selection leads to optimum smoothing that leads to a better quantification followed by correct diagnosis and accurate interpretation by the physician. This study aims at evaluating the low pass filters on SPECT reconstruction algorithms. Criteria for evaluating the filters are estimating the SPECT reconstructed cardiac azimuth and elevation angle. Low pass filters studied are butterworth, gaussian, hamming, hanning and parzen. Experiments are conducted using three reconstruction algorithms, FBP (filtered back projection), MLEM (maximum likelihood expectation maximization) and OSEM (ordered subsets expectation maximization), on four gated cardiac patient projections (two patients with stress and rest projections). Each filter is applied with varying cutoff and order for each reconstruction algorithm (only butterworth used for MLEM and OSEM). The azimuth and elevation angles are calculated from the reconstructed volume and the variation observed in the angles with varying filter parameters is reported. Our results demonstrate that behavior of hamming, hanning and parzen filter (used with FBP) with varying cutoff is similar for all the datasets. Butterworth filter (cutoff > 0.4) behaves in a similar fashion for all the datasets using all the algorithms whereas with OSEM for a cutoff < 0.4, it fails to generate cardiac orientation due to oversmoothing, and gives an unstable response with FBP and MLEM. This study on evaluating effect of low pass filter cutoff and order on cardiac orientation using three different reconstruction algorithms provides an interesting insight into optimal selection of filter parameters.

  14. Limbus- versus fornix-based trabeculectomy for open-angle glaucoma eyes with prior ocular surgery: the Collaborative Bleb-Related Infection Incidence and Treatment Study.

    PubMed

    Yokota, Satoshi; Takihara, Yuji; Inatani, Masaru

    2015-03-19

    We compared the surgical successes of limbus- and fornix-based trabeculectomies in open-angle glaucoma (OAG) eyes that had prior ocular surgery in the Collaborative Bleb-Related Infection Incidence and Treatment Study (CBIITS), Japan. From the 1,098 glaucoma eyes in 34 clinical centers in CBIITS, 195 OAG eyes that had undergone previous trabeculectomy and/or lens extraction were included. Limbus- or fornix-based trabeculectomy with mitomycin C were performed. Surgical failure (IOP ≥ 21, 18, or 15 mmHg for criterion A, B or C, respectively; <20% decrease from baseline; reoperation for glaucoma; or loss of light perception vision) was counted. There were 106 and 89 eyes treated with limbus- and fornix-based trabeculectomies, respectively. At 3 years, IOP (mean ± SD) was 12.5 ± 5.9 and 14.1 ± 6.4 mmHg and the cumulative probabilities of failure during 3 years were 30.2% and 50.5% for criterion A, 40.3% and 57.4% for criterion B, and 57.9% and 65.8% for criterion C in the limbus- and the fornix-based group, respectively. Fornix-based incisions were associated with surgical failure in Cox-proportional multivariable analysis for criterion A [relative risk (RR) = 1.96], and B [RR = 1.60]. Limbus-based trabeculectomy had a higher probability of success in OAG eyes with prior ocular surgery.

  15. The Fras1/Frem family of extracellular matrix proteins: structure, function, and association with Fraser syndrome and the mouse bleb phenotype.

    PubMed

    Petrou, Petros; Makrygiannis, Apostolos K; Chalepakis, Georges

    2008-01-01

    Fras1 and the structurally related proteins Frem1, Frem2, and Frem3, comprise a novel family of extracellular matrix proteins, which localize in a similar fashion underneath the lamina densa of epithelial basement membranes. They are involved in the structural adhesion of the skin epithelium to its underlying mesenchyme. Deficiency in the individual murine Fras1/Frem genes gives rise to the bleb phenotype, which is equivalent to the human hereditary disorder Fraser syndrome, characterized by cryptophthalmos (hidden eyes), embryonic skin blistering, renal agenesis, and syndactyly. Recent studies revealed a functional cooperation between the Fras1/Frem gene products, in which Fras1, Frem1 and Frem2 are simultaneously stabilized at the lowermost region of the basement membrane by forming a macromolecular ternary complex. Loss of any of these proteins results in the collapse of the protein assembly, thus providing a molecular explanation for the highly similar phenotypic defects displayed by the respective mutant mice. Here, we summarize the current knowledge regarding the structure, function, and interplay between the proteins of the Fras1/Frem family and further propose a possible scenario for the evolution of the corresponding genes.

  16. An Adaptive Fourier Filter for Relaxing Time Stepping Constraints for Explicit Solvers

    SciTech Connect

    Gelb, Anne; Archibald, Richard K

    2015-01-01

    Filtering is necessary to stabilize piecewise smooth solutions. The resulting diffusion stabilizes the method, but may fail to resolve the solution near discontinuities. Moreover, high order filtering still requires cost prohibitive time stepping. This paper introduces an adaptive filter that controls spurious modes of the solution, but is not unnecessarily diffusive. Consequently we are able to stabilize the solution with larger time steps, but also take advantage of the accuracy of a high order filter.

  17. Closure of 324 Facility potential HEPA filter failure unreviewed safety questions

    SciTech Connect

    Enghusen, M.B.

    1997-11-07

    This document summarizes the activities which occurred to resolve an Unreviewed Safety Question (USQ) for the 324 Facility [Waste Technology Engineering Laboratory] involving Potential HEPA Filter Breach. The facility ventilation system had the capacity to fail the HEPA filters during accident conditions which would totally plug the filters. The ventilation system fans were modified which lowered fan operating parameters and prevented HEPA filter failures which might occur during accident conditions.

  18. Pass-Fail: How Is It Working?

    ERIC Educational Resources Information Center

    Chase, Clinton I.; And Others

    This study investigates the pass/fail (P/F) grading system. A sample of 154 Indiana University students was interviewed. Half of the group, 77 students, had not taken any P/F courses. Of the remaining 77 students, 42% had taken only one P/F course and most of the rest from two to five courses. Results of the student interview questionnaire…

  19. Fail-soft turbocharger control system

    SciTech Connect

    Fujawa, C.S.; Masteller, S.B.

    1986-08-05

    A fail-soft turbocharger control system is described for an engine with a first bank and a second bank of cylinders and a first turbocharger and second turbocharger associated therewith. Each turbocharger has a variable output compressor boosting the pressure of an input manifold to the associated bank of cylinders and a variable input turbine driving the compressor powered by the exhaust gases of the bank of cylinders for the control system.

  20. Neurolysis for failed tarsal tunnel surgery.

    PubMed

    Yalcinkaya, Merter; Ozer, Utku Erdem; Yalcin, M Burak; Bagatur, A Erdem

    2014-01-01

    The purpose of the present study was to investigate the causes of failure after tarsal tunnel release and the operative findings in the secondary interventions and the outcomes. The data from 8 patients who had undergone revision surgery for failed tarsal tunnel release at least 12 months earlier were evaluated retrospectively. Only the patients with idiopathic tarsal tunnel syndrome were included, and all had unilateral symptoms. Neurophysiologic tests confirmed the clinical diagnosis of failed tarsal tunnel release in all patients. Magnetic resonance imaging revealed varicose veins within the tarsal tunnel in 1 patient (12.5%) and tenosynovitis in another (12.5%). Open tarsal tunnel release was performed in all patients, and the tibialis posterior nerve, medial and lateral plantar nerves (including the first branch of the lateral plantar nerve), and medial calcaneal nerve were released in their respective tunnels, and the septum between the tunnels was resected. The outcomes were assessed according to subjective patient satisfaction as excellent, good, fair, or poor. During revision surgery, insufficient release of the tarsal tunnel, especially distally, was observed in all the patients, and fibrosis of the tibialis posterior nerve was present in 1 (12.5%). The outcomes according to subjective patient satisfaction were excellent in 5 (62.5%), good in 2 (25%), and fair in 1 (12.5%). The fair outcome was obtained in the patient with fibrosis of the nerve. Insufficient release of the tarsal tunnel was the main cause of failed tarsal tunnel release. Releasing the 4 distinct tunnels and permitting immediate mobilization provided satisfactory results in patients with failed tarsal tunnel release. PMID:25128912

  1. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    E.S. Connolly; G.D. Forsythe

    1998-12-22

    Advanced, coal-based power plants will require durable and reliable hot gas filtration systems to remove particulate contaminants from the gas streams to protect downstream components such as turbine blades from erosion damage. It is expected that the filter elements in these systems will have to be made of ceramic materials to withstand goal service temperatures of 1600 F or higher. Recent demonstration projects and pilot plant tests have indicated that the current generation of ceramic hot gas filters (cross-flow and candle configurations) are failing prematurely. Two of the most promising materials that have been extensively evaluated are clay-bonded silicon carbide and alumina-mullite porous monoliths. These candidates, however, have been found to suffer progressive thermal shock fatigue damage, as a result of rapid cooling/heating cycles. Such temperature changes occur when the hot filters are back-pulsed with cooler gas to clean them, or in process upset conditions, where even larger gas temperature changes may occur quickly and unpredictably. In addition, the clay-bonded silicon carbide materials are susceptible to chemical attack of the glassy binder phase that holds the SiC particles together, resulting in softening, strength loss, creep, and eventual failure.

  2. ARRANGEMENT FOR REPLACING FILTERS

    DOEpatents

    Blomgren, R.A.; Bohlin, N.J.C.

    1957-08-27

    An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

  3. Method of securing filter elements

    DOEpatents

    Brown, Erik P.; Haslam, Jeffery L.; Mitchell, Mark A.

    2016-10-04

    A filter securing system including a filter unit body housing; at least one tubular filter element positioned in the filter unit body housing, the tubular filter element having a closed top and an open bottom; a dimple in either the filter unit body housing or the top of the tubular filter element; and a socket in either the filter unit body housing or the top of the tubular filter element that receives the dimple in either the filter unit body housing or the top of the tubular filter element to secure the tubular filter element to the filter unit body housing.

  4. SPECTRA AND LIGHT CURVES OF FAILED SUPERNOVAE

    SciTech Connect

    Fryer, Chris L.; Dahl, Jon A.; Fontes, Christopher J. E-mail: dahl@lanl.go

    2009-12-10

    Astronomers have proposed a number of mechanisms to produce supernova explosions. Although many of these mechanisms are now not considered primary engines behind supernovae (SNe), they do produce transients that will be observed by upcoming ground-based surveys and NASA satellites. Here, we present the first radiation-hydrodynamics calculations of the spectra and light curves from three of these 'failed' SNe: SNe with considerable fallback, accretion-induced collapse of white dwarfs, and energetic helium flashes (also known as type Ia SNe).

  5. Rigid porous filter

    DOEpatents

    Chiang, Ta-Kuan; Straub, Douglas L.; Dennis, Richard A.

    2000-01-01

    The present invention involves a porous rigid filter including a plurality of concentric filtration elements having internal flow passages and forming external flow passages there between. The present invention also involves a pressure vessel containing the filter for the removal of particulates from high pressure particulate containing gases, and further involves a method for using the filter to remove such particulates. The present filter has the advantage of requiring fewer filter elements due to the high surface area-to-volume ratio provided by the filter, requires a reduced pressure vessel size, and exhibits enhanced mechanical design properties, improved cleaning properties, configuration options, modularity and ease of fabrication.

  6. Filter type gas sampler with filter consolidation

    DOEpatents

    Miley, Harry S.; Thompson, Robert C.; Hubbard, Charles W.; Perkins, Richard W.

    1997-01-01

    Disclosed is an apparatus for automatically consolidating a filter or, more specifically, an apparatus for drawing a volume of gas through a plurality of sections of a filter, whereafter the sections are subsequently combined for the purpose of simultaneously interrogating the sections to detect the presence of a contaminant.

  7. Filter type gas sampler with filter consolidation

    DOEpatents

    Miley, H.S.; Thompson, R.C.; Hubbard, C.W.; Perkins, R.W.

    1997-03-25

    Disclosed is an apparatus for automatically consolidating a filter or, more specifically, an apparatus for drawing a volume of gas through a plurality of sections of a filter, where after the sections are subsequently combined for the purpose of simultaneously interrogating the sections to detect the presence of a contaminant. 5 figs.

  8. HEPA Filter Vulnerability Assessment

    SciTech Connect

    GUSTAVSON, R.D.

    2000-05-11

    This assessment of High Efficiency Particulate Air (HEPA) filter vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of filter degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA filters that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA filters that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the filters. Filter degradation factors considered include aging, wetting of filters, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA filter experts from published empirical data. For River Protection Project (RPP) filters, the only degradation factor that exceeded the screening threshold was for filter aging. Subsequent evaluation of the effect of filter aging on the filter strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in filter strength due to aging does not affect the filter performance requirements as specified in the AB. A portion of the HEPA filter vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA filters used for SC/SS service. This document presents the results of a HEPA filter vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection.

  9. Cordierite silicon nitride filters

    SciTech Connect

    Sawyer, J.; Buchan, B. ); Duiven, R.; Berger, M. ); Cleveland, J.; Ferri, J. )

    1992-02-01

    The objective of this project was to develop a silicon nitride based crossflow filter. This report summarizes the findings and results of the project. The project was phased with Phase I consisting of filter material development and crossflow filter design. Phase II involved filter manufacturing, filter testing under simulated conditions and reporting the results. In Phase I, Cordierite Silicon Nitride (CSN) was developed and tested for permeability and strength. Target values for each of these parameters were established early in the program. The values were met by the material development effort in Phase I. The crossflow filter design effort proceeded by developing a macroscopic design based on required surface area and estimated stresses. Then the thermal and pressure stresses were estimated using finite element analysis. In Phase II of this program, the filter manufacturing technique was developed, and the manufactured filters were tested. The technique developed involved press-bonding extruded tiles to form a filter, producing a monolithic filter after sintering. Filters manufactured using this technique were tested at Acurex and at the Westinghouse Science and Technology Center. The filters did not delaminate during testing and operated and high collection efficiency and good cleanability. Further development in areas of sintering and filter design is recommended.

  10. Ranking nodes in growing networks: When PageRank fails

    PubMed Central

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-01-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes. PMID:26553630

  11. Mitochondrial protein hyperacetylation in the failing heart

    PubMed Central

    Horton, Julie L.; Martin, Ola J.; Lai, Ling; Richards, Alicia L.; Vega, Rick B.; Leone, Teresa C.; Pagliarini, David J.; Muoio, Deborah M.; Bedi, Kenneth C.; Coon, Joshua J.

    2016-01-01

    Myocardial fuel and energy metabolic derangements contribute to the pathogenesis of heart failure. Recent evidence implicates posttranslational mechanisms in the energy metabolic disturbances that contribute to the pathogenesis of heart failure. We hypothesized that accumulation of metabolite intermediates of fuel oxidation pathways drives posttranslational modifications of mitochondrial proteins during the development of heart failure. Myocardial acetylproteomics demonstrated extensive mitochondrial protein lysine hyperacetylation in the early stages of heart failure in well-defined mouse models and the in end-stage failing human heart. To determine the functional impact of increased mitochondrial protein acetylation, we focused on succinate dehydrogenase A (SDHA), a critical component of both the tricarboxylic acid (TCA) cycle and respiratory complex II. An acetyl-mimetic mutation targeting an SDHA lysine residue shown to be hyperacetylated in the failing human heart reduced catalytic function and reduced complex II–driven respiration. These results identify alterations in mitochondrial acetyl-CoA homeostasis as a potential driver of the development of energy metabolic derangements that contribute to heart failure. PMID:26998524

  12. The evaluation of the failed shoulder arthroplasty.

    PubMed

    Wiater, Brett P; Moravek, James E; Wiater, J Michael

    2014-05-01

    As the incidence of shoulder arthroplasty continues to rise, the orthopedic shoulder surgeon will be increasingly faced with the difficult problem of evaluating a failed shoulder arthroplasty. The patient is usually dissatisfied with the outcome of the previous arthroplasty as a result of pain, but may complain of poor function due to limited range of motion or instability. A thorough and systematic approach is necessary so that the most appropriate treatment pathway can be initiated. A comprehensive history and physical examination are the first steps in the evaluation. Diagnostic studies are numerous and include laboratory values, plain radiography, computed tomography, ultrasound imaging, joint aspiration, nuclear scans, and electromyography. Common causes of early pain after shoulder arthroplasty include technical issues related to the surgery, such as malposition or improper sizing of the prosthesis, periprosthetic infection, neurologic injury, and complex regional pain syndrome. Pain presenting after a symptom-free interval may be related to chronic periprosthetic infection, component wear and loosening, glenoid erosion, rotator cuff degeneration, and fracture. Poor range of motion may result from inadequate postoperative rehabilitation, implant-related factors, and heterotopic ossification. Instability is generally caused by rotator cuff deficiency and implant-related factors. Unfortunately, determining the cause of a failed shoulder arthroplasty can be difficult, and in many situations, the source of pain and disability is multifactorial.

  13. Removal of failed crown and bridge

    PubMed Central

    Rahul, G R.; Poduval, Soorya T.; Shetty, Karunakar

    2012-01-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  14. Removal of failed crown and bridge.

    PubMed

    Sharma, Ashu; Rahul, G R; Poduval, Soorya T; Shetty, Karunakar

    2012-07-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  15. Effect of Two Novel Sustained-Release Drug Delivery Systems on Bleb Fibrosis: An In Vivo Glaucoma Drainage Device Study in a Rabbit Model

    PubMed Central

    Schoenberg, Evan D.; Blake, Diane A.; Swann, F. Beau; Parlin, Andrew W.; Zurakowski, David; Margo, Curtis E.; Ponnusamy, Thiruselvam; John, Vijay T.; Ayyala, Ramesh S.

    2015-01-01

    Purpose: To evaluate two drug delivery systems, a nonbiodegradable poly(2-hydroxyethyl methacrylate) (P[HEMA]) system with mitomycin C (MMC) and a biodegradable poly(lactic-co-glycolic acid) (PLGA) system with 5-fluorouracil (5-FU) with and without MMC for their ability to reduce fibrosis when attached to an Ahmed glaucoma valve (AGV) and implanted in a rabbit model. Methods: New Zealand albino rabbits (48) were divided into six equal groups, and AGVs, modified as described below, were implanted in the right eye of each rabbit. The groups included (1) PLGA alone; (2) P(HEMA) plus MMC (6.5 μg); (3) PLGA plus 5-FU (0.45 mg); (4) PLGA plus 5-FU (1.35 mg); (5) PLGA plus 5-FU and MMC (0.45 mg and 0.65 μg, respectively); (6) PLGA plus 5-FU and MMC (1.35 mg and 0.65 μg, respectively). The rabbits were followed for 3 months prior to euthanasia. Results: The bleb wall thickness was significantly less in groups 2, 5, and 6 compared to the rest. At 3 months, the PLGA polymer had completely disappeared, while the P(HEMA) polymer remained intact. There were no statistical differences in the degree of clinically graded conjunctival injection, histologic inflammation, or histologic fibrosis among the six groups. Conclusions: We successfully created a sustained-release drug delivery system that decreased the postoperative fibrosis using both a nonbiodegradable P(HEMA) polymer and a biodegradable (PLGA) polymer. Both systems appear to work equally well with no side effects. Translational Relevance: These results are supportive of the antifibrotic effect of the slow-release drug delivery system following glaucoma drainage device implantation, thus paving the way for human pilot studies. PMID:26046006

  16. Apical blebs on sperm storage tubule epithelial cell microvilli: their release and interaction with resident sperm in the turkey hen oviduct.

    PubMed

    Bakst, Murray R; Bauchan, Gary

    2015-06-01

    Located at the anterior end of the turkey hen's vagina are numerous discrete tubular invaginations of the surface epithelium, collectively referred to as the sperm storage tubules (SSTs). After mating or artificial insemination, sperm ascend the vagina, enter the SSTs, and over the ensuing days and weeks, gradually exit the SSTs and are transported to the anterior end of the oviduct to fertilize a daily succession of ova. Little is known regarding the cellular and molecular mechanisms responsible for sperm subsistence in the lumen of the SST. In this study, the origin of microvillus blebs (MvBs) on the apical tips of SST epithelial cells was examined, and their possible role in sperm survival was discussed. Regardless, if sperm are present or not, transmission electron microscopy revealed two types of microvilli differentiated by the presence or absence of pleomorphic unilaminar MvBs localized to their apical tips. Although some MvBs appeared to be discharging their contents into the SST lumen, others appeared to have pinched off the microvillus stem. When SSTs contained clusters of densely packed sperm, the sperm heads of those sperm adjacent to the SST epithelial cell surface were surrounded by the microvilli. Associated with the plasmalemma of sperm throughout the SST lumina were membrane fragments and small vesicles (30-130 nm in diameter), some of which appeared to have fused with sperm. It is concluded that the MvBs are a form of shedding vesicle released from the SST epithelial cell microvilli by apocrine secretion. On the basis of observations described herein and those of other authors, it is suggested that the MvBs contribute to sustained sperm storage in the SSTs by (1) supplying metabolic substrates used by resident sperm, (2) serving as fusogenic vehicles providing exogenous macromolecules that reversibly suppress sperm functions associated with fertilization (decapacitation?) and stabilize the sperm plasmalemma, and (3) acting as transport vesicles

  17. HEPA filter monitoring program

    NASA Astrophysics Data System (ADS)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  18. Bag filters for TPP

    SciTech Connect

    L.V. Chekalov; Yu.I. Gromov; V.V. Chekalov

    2007-05-15

    Cleaning of TPP flue gases with bag filters capable of pulsed regeneration is examined. A new filtering element with a three-dimensional filtering material formed from a needle-broached cloth in which the filtration area, as compared with a conventional smooth bag, is increased by more than two times, is proposed. The design of a new FRMI type of modular filter is also proposed. A standard series of FRMI filters with a filtration area ranging from 800 to 16,000 m{sup 2} is designed for an output more than 1 million m{sub 3}/h of with respect to cleaned gas. The new bag filter permits dry collection of sulfur oxides from waste gases at TPP operating on high-sulfur coals. The design of the filter makes it possible to replace filter elements without taking the entire unit out of service.

  19. MST Filterability Tests

    SciTech Connect

    Poirier, M. R.; Burket, P. R.; Duignan, M. R.

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  20. Survey of digital filtering

    NASA Technical Reports Server (NTRS)

    Nagle, H. T., Jr.

    1972-01-01

    A three part survey is made of the state-of-the-art in digital filtering. Part one presents background material including sampled data transformations and the discrete Fourier transform. Part two, digital filter theory, gives an in-depth coverage of filter categories, transfer function synthesis, quantization and other nonlinear errors, filter structures and computer aided design. Part three presents hardware mechanization techniques. Implementations by general purpose, mini-, and special-purpose computers are presented.

  1. A Solution to ``Too Big to Fail''

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-10-01

    Its a tricky business to reconcile simulations of our galaxys formation with our current observations of the Milky Way and its satellites. In a recent study, scientists have addressed one discrepancy between simulations and observations: the so-called to big to fail problem.From Missing Satellites to Too Big to FailThe favored model of the universe is the lambda-cold-dark-matter (CDM) cosmological model. This model does a great job of correctly predicting the large-scale structure of the universe, but there are still a few problems with it on smaller scales.Hubble image of UGC 5497, a dwarf galaxy associated with Messier 81. In the missing satellite problem, simulations of galaxy formation predict that there should be more such satellite galaxies than we observe. [ESA/NASA]The first is the missing satellites problem: CDM cosmology predicts that galaxies like the Milky Way should have significantly more satellite galaxies than we observe. A proposed solution to this problem is the argument that there may exist many more satellites than weve observed, but these dwarf galaxies have had their stars stripped from them during tidal interactions which prevents us from being able to see them.This solution creates a new problem, though: the too big to fail problem. This problem states that many of the satellites predicted by CDM cosmology are simply so massive that theres no way they couldnt have visible stars. Another way of looking at it: the observed satellites of the Milky Way are not massive enough to be consistent with predictions from CDM.Artists illustration of a supernova, a type of stellar feedback that can modify the dark-matter distribution of a satellite galaxy. [NASA/CXC/M. Weiss]Density Profiles and Tidal StirringLed by Mihai Tomozeiu (University of Zurich), a team of scientists has published a study in which they propose a solution to the too big to fail problem. By running detailed cosmological zoom simulations of our galaxys formation, Tomozeiu and

  2. Filter service system

    DOEpatents

    Sellers, Cheryl L.; Nordyke, Daniel S.; Crandell, Richard A.; Tomlins, Gregory; Fei, Dong; Panov, Alexander; Lane, William H.; Habeger, Craig F.

    2008-12-09

    According to an exemplary embodiment of the present disclosure, a system for removing matter from a filtering device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the filtering device. The system also includes a vacuum source fluidly connected to a second orifice of the filtering device.

  3. Practical Active Capacitor Filter

    NASA Technical Reports Server (NTRS)

    Shuler, Robert L., Jr. (Inventor)

    2005-01-01

    A method and apparatus is described that filters an electrical signal. The filtering uses a capacitor multiplier circuit where the capacitor multiplier circuit uses at least one amplifier circuit and at least one capacitor. A filtered electrical signal results from a direct connection from an output of the at least one amplifier circuit.

  4. HEPA filter encapsulation

    DOEpatents

    Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.

    2003-01-01

    A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

  5. Nonlinear Attitude Filtering Methods

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Crassidis, John L.; Cheng, Yang

    2005-01-01

    This paper provides a survey of modern nonlinear filtering methods for attitude estimation. Early applications relied mostly on the extended Kalman filter for attitude estimation. Since these applications, several new approaches have been developed that have proven to be superior to the extended Kalman filter. Several of these approaches maintain the basic structure of the extended Kalman filter, but employ various modifications in order to provide better convergence or improve other performance characteristics. Examples of such approaches include: filter QUEST, extended QUEST, the super-iterated extended Kalman filter, the interlaced extended Kalman filter, and the second-order Kalman filter. Filters that propagate and update a discrete set of sigma points rather than using linearized equations for the mean and covariance are also reviewed. A two-step approach is discussed with a first-step state that linearizes the measurement model and an iterative second step to recover the desired attitude states. These approaches are all based on the Gaussian assumption that the probability density function is adequately specified by its mean and covariance. Other approaches that do not require this assumption are reviewed, including particle filters and a Bayesian filter based on a non-Gaussian, finite-parameter probability density function on SO(3). Finally, the predictive filter, nonlinear observers and adaptive approaches are shown. The strengths and weaknesses of the various approaches are discussed.

  6. Fail-over file transfer process

    NASA Technical Reports Server (NTRS)

    Semancik, Susan K. (Inventor); Conger, Annette M. (Inventor)

    2005-01-01

    The present invention provides a fail-over file transfer process to handle data file transfer when the transfer is unsuccessful in order to avoid unnecessary network congestion and enhance reliability in an automated data file transfer system. If a file cannot be delivered after attempting to send the file to a receiver up to a preset number of times, and the receiver has indicated the availability of other backup receiving locations, then the file delivery is automatically attempted to one of the backup receiving locations up to the preset number of times. Failure of the file transfer to one of the backup receiving locations results in a failure notification being sent to the receiver, and the receiver may retrieve the file from the location indicated in the failure notification when ready.

  7. The best argument against kidney sales fails.

    PubMed

    Semrau, Luke

    2015-06-01

    Simon Rippon has recently argued against kidney markets on the grounds that introducing the option to vend will result in many people, especially the poor, being subject to harmful pressure to vend. Though compelling, Rippon's argument fails. What he takes to be a single phenomenon-social and legal pressure to vend-is actually two. Only one of these forms of pressure is, by Rippon's own account, harmful. Further, an empirically informed view of the regulated market suggests that this harmful pressure is easily avoided. Thus, the harm that is the lynchpin of Rippon's opposition is neither a necessary feature of the market nor is it likely to play a significant role in its operation.

  8. New approaches to supporting the failing liver.

    PubMed

    Cao, S; Esquivel, C O; Keeffe, E B

    1998-01-01

    With the continued, growing disparity between the numbers of organ donations and patients waiting for liver transplantation, various efforts have been made to optimize the allocation of organs, as well as to devise means to support the failing liver. Over the years, the development of bioartificial liver-assist devices has aimed at replacing the three main functions of hepatocytes, which are synthetic, metabolic, and excretory. The application of porcine hepatocytes in humans to carry out biotransformation, as well as other metabolic functions and refinement of the membrane separator, have yielded some promising results in supporting patients with acute liver failure. Further advances will need to be made before these bioartificial devices can be considered for routine application in clinical settings.

  9. Etiologic analysis of 100 anatomically failed dacryocystorhinostomies

    PubMed Central

    Dave, Tarjani Vivek; Mohammed, Faraz Ali; Ali, Mohammad Javed; Naik, Milind N

    2016-01-01

    Background The aim of this study was to assess the etiological factors contributing to the failure of a dacryocystorhinostomy (DCR). Patients and methods Retrospective review was performed in 100 consecutive patients who were diagnosed with anatomically failed DCR at presentation to a tertiary care hospital over a 5-year period from 2010 to 2015. Patient records were reviewed for demographic data, type of past surgery, preoperative endoscopic findings, previous use of adjuvants such as intubation and mitomycin C, and intraoperative notes during the re-revision. The potential etiological factors for failure were noted. Results Of the 100 patients with failed DCRs, the primary surgery was an external DCR in 73 and endoscopic DCR in 27 patients. Six patients in each group had multiple revisions. The mean ages at presentation in the external and endoscopic groups were 39.41 years and 37.19 years, respectively. All patients presented with epiphora. The most common causes of failure were inadequate osteotomy (69.8% in the external group and 85.1% in the endoscopic group, P=0.19) followed by inadequate or inappropriate sac marsupialization (60.2% in the external group and 77.7% in the endoscopic group, P=0.16) and cicatricial closure of the ostium (50.6% in the external group and 55.5% in the endoscopic group, P=0.83). The least common causes such as ostium granulomas and paradoxical middle turbinate (1.37%, n=1) were noted in the external group only. Conclusion Inadequate osteotomy, incomplete sac marsupialization, and cicatricial closure of the ostium were the most common causes of failure and did not significantly differ in the external and endoscopic groups. Meticulous evaluation to identify causative factors for failure and addressing them are crucial for subsequent successful outcomes. PMID:27555748

  10. Salvage arthrodesis for failed total ankle arthroplasty

    PubMed Central

    Zürcher, Arthur W

    2010-01-01

    Background and purpose Total ankle arthroplasty (TAA) has gained popularity in recent years. If it fails, however, salvage arthrodesis must be reliable as a rescue procedure. We therefore investigated the clinical, radiographic, and subjective outcome after salvage arthrodesis in a consecutive group of patients, and concentrated on the influence of the method of fixation on union rate and on salvage in inflammatory joint disease. Patients and methods Between 1994 and 2005, salvage arthrodesis was performed on 18 ankles (18 patients). Diagnosis was inflammatory joint disease (IJD) in 15 cases and osteoarthritis (OA) in 3. Tibio-talar fusion was performed in 7 ankles, and tibio-talocalcaneal fusion in 11. Serial radiographs were studied for time to union. Clinical outcome at latest follow-up was measured by the AOFAS score, the foot function index (FFI) and by VAS scores for pain, function, and satisfaction. Results Blade plates were used in 7 ankles (4 IJD, 3 OA); all united. Nonunion developed in 7 of the 11 rheumatic ankles stabilized by other methods. 11 patients (8 fused ankles, 3 nonunions) were available for clinical evaluation. Their mean AOFAS score was 62 and mean overall FFI was 70. VAS score for pain was 20, for function 64, and for satisfaction 74. The scores were similar in united and non-united ankles. Interpretation Blade plate fixation is successful in salvage arthrodesis for failed TAA. A high nonunion rate was found after salvage ankle arthrodesis in IJD with other methods of fixation. Clinical results were fair to good. PMID:20175648

  11. Regenerative particulate filter development

    NASA Technical Reports Server (NTRS)

    Descamp, V. A.; Boex, M. W.; Hussey, M. W.; Larson, T. P.

    1972-01-01

    Development, design, and fabrication of a prototype filter regeneration unit for regenerating clean fluid particle filter elements by using a backflush/jet impingement technique are reported. Development tests were also conducted on a vortex particle separator designed for use in zero gravity environment. A maintainable filter was designed, fabricated and tested that allows filter element replacement without any leakage or spillage of system fluid. Also described are spacecraft fluid system design and filter maintenance techniques with respect to inflight maintenance for the space shuttle and space station.

  12. Ceramic fiber filter technology

    SciTech Connect

    Holmes, B.L.; Janney, M.A.

    1996-06-01

    Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

  13. Compact planar microwave blocking filters

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)

    2012-01-01

    A compact planar microwave blocking filter includes a dielectric substrate and a plurality of filter unit elements disposed on the substrate. The filter unit elements are interconnected in a symmetrical series cascade with filter unit elements being organized in the series based on physical size. In the filter, a first filter unit element of the plurality of filter unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the filter.

  14. Many Teens Give Sex Ed a Failing Grade

    MedlinePlus

    ... gov/news/fullstory_160906.html Many Teens Give Sex Ed a Failing Grade International study finds courses ... HealthDay News) -- Teens around the world are getting sex education in schools that fail to address their ...

  15. Federated nonlinear predictive filtering for the gyroless attitude determination system

    NASA Astrophysics Data System (ADS)

    Zhang, Lijun; Qian, Shan; Zhang, Shifeng; Cai, Hong

    2016-11-01

    This paper presents a federated nonlinear predictive filter (NPF) for the gyroless attitude determination system with star sensor and Global Positioning System (GPS) sensor. This approach combines the good qualities of both the NPF and federated filter. In order to combine them, the equivalence relationship between the NPF and classical Kalman filter (KF) is demonstrated from algorithm structure and estimation criterion. The main features of this approach include a nonlinear predictive filtering algorithm to estimate uncertain model errors and determine the spacecraft attitude by using attitude kinematics and dynamics, and a federated filtering algorithm to process measurement data from multiple attitude sensors. Moreover, a fault detection and isolation algorithm is applied to the proposed federated NPF to improve the estimation accuracy even when one sensor fails. Numerical examples are given to verify the navigation performance and fault-tolerant performance of the proposed federated nonlinear predictive attitude determination algorithm.

  16. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  17. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  18. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  19. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  20. 75 FR 76321 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ78 Source of Income From Qualified Fails Charges AGENCY... Internal Revenue Code. These regulations set forth the source of income attributable to qualified fails... the treatment of fails charges for purposes of sections 871, 881, 1441 and 1442 by establishing...

  1. 30 CFR 77.312 - Fail safe monitoring systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe monitoring systems. 77.312 Section 77... Thermal Dryers § 77.312 Fail safe monitoring systems. Thermal dryer systems and controls shall be protected by a fail safe monitoring system which will safely shut down the system and any related...

  2. Capital disadvantage: America's failing capital investment system.

    PubMed

    Porter, M E

    1992-01-01

    The U.S. system of allocating investment capital is failing, putting American companies at a serious disadvantage and threatening the long-term growth of the nation's economy. The problem, says Michael Porter, goes beyond the usual formulation of the issue: accusations of "short-termism" by U.S. managers, ineffective corporate governance by directors, or a high cost of capital. The problem involves the external capital allocation system by which capital is provided to companies, as well as the system by which companies allocate capital internally. America's system is marked by fluid capital and a financial focus. Other countries--notably Japan and Germany--have systems with dedicated capital and a focus on corporate position. In global competition, where investment increasingly determines a company's capacity to upgrade and innovate, the U.S. system does not measure up. These conclusions come out of a two-year research project sponsored by the Harvard Business School and the Council on Competitiveness. Porter recommends five far-reaching reforms to make the U.S. system superior to Japan's and Germany's: 1. Improve the present macroeconomic environment. 2. Expand true ownership throughout the system so that directors, managers, employees, and even customers and suppliers hold positions as owners. 3. Align the goals of capital providers, corporations, directors, managers, employees, customers, suppliers, and society. 4. Improve the information used in decision making. 5. Foster more productive modes of interaction and influence among capital providers, corporations, and business units. PMID:10121317

  3. Cognitive emotion regulation fails the stress test.

    PubMed

    Raio, Candace M; Orederu, Temidayo A; Palazzolo, Laura; Shurick, Ashley A; Phelps, Elizabeth A

    2013-09-10

    Cognitive emotion regulation has been widely shown in the laboratory to be an effective way to alter the nature of emotional responses. Despite its success in experimental contexts, however, we often fail to use these strategies in everyday life where stress is pervasive. The successful execution of cognitive regulation relies on intact executive functioning and engagement of the prefrontal cortex, both of which are rapidly impaired by the deleterious effects of stress. Because it is specifically under stressful conditions that we may benefit most from such deliberate forms of emotion regulation, we tested the efficacy of cognitive regulation after stress exposure. Participants first underwent fear-conditioning, where they learned that one stimulus (CS+) predicted an aversive outcome but another predicted a neutral outcome (CS-). Cognitive regulation training directly followed where participants were taught to regulate fear responses to the aversive stimulus. The next day, participants underwent an acute stress induction or a control task before repeating the fear-conditioning task using these newly acquired regulation skills. Skin conductance served as an index of fear arousal, and salivary α-amylase and cortisol concentrations were assayed as neuroendocrine markers of stress response. Although groups showed no differences in fear arousal during initial fear learning, nonstressed participants demonstrated robust fear reduction following regulation training, whereas stressed participants showed no such reduction. Our results suggest that stress markedly impairs the cognitive regulation of emotion and highlights critical limitations of this technique to control affective responses under stress.

  4. Rescuing failed oral implants via Wnt activation

    PubMed Central

    Yin, Xing; Li, Jingtao; Chen, Tao; Mouraret, Sylvain; Dhamdhere, Girija; Brunski, John B.; Zou, Shujuan; Helms, Jill A.

    2016-01-01

    Aim Implant osseointegration is not always guaranteed and once fibrous encapsulation occurs clinicians have few options other than implant removal. Our goal was to test whether a WNT protein therapeutic could rescue such failed implants. Material and Methods Titanium implants were placed in over-sized murine oral osteotomies. A lack of primary stability was verified by mechanical testing. Interfacial strains were estimated by finite element modelling and histology coupled with histomorphometry confirmed the lack of peri-implant bone. After fibrous encapsulation was established peri-implant injections of a liposomal formulation of WNT3A protein (L-WNT3A) or liposomal PBS (L-PBS) were then initiated. Quantitative assays were employed to analyse the effects of L-WNT3A treatment. Results Implants in gap-type interfaces exhibited high interfacial strains and no primary stability. After verification of implant failure, L-WNT3A or L-PBS injections were initiated. L-WNT3A induced a rapid, significant increase in Wnt responsiveness in the peri-implant environment, cell proliferation and osteogenic protein expression. The amount of peri-implant bone and bone in contact with the implant were significantly higher in L-WNT3A cases. Conclusions These data demonstrate L-WNT3A can induce peri-implant bone formation even in cases where fibrous encapsulation predominates. PMID:26718012

  5. How to fail at species delimitation.

    PubMed

    Carstens, Bryan C; Pelletier, Tara A; Reid, Noah M; Satler, Jordan D

    2013-09-01

    Species delimitation is the act of identifying species-level biological diversity. In recent years, the field has witnessed a dramatic increase in the number of methods available for delimiting species. However, most recent investigations only utilize a handful (i.e. 2-3) of the available methods, often for unstated reasons. Because the parameter space that is potentially relevant to species delimitation far exceeds the parameterization of any existing method, a given method necessarily makes a number of simplifying assumptions, any one of which could be violated in a particular system. We suggest that researchers should apply a wide range of species delimitation analyses to their data and place their trust in delimitations that are congruent across methods. Incongruence across the results from different methods is evidence of either a difference in the power to detect cryptic lineages across one or more of the approaches used to delimit species and could indicate that assumptions of one or more of the methods have been violated. In either case, the inferences drawn from species delimitation studies should be conservative, for in most contexts it is better to fail to delimit species than it is to falsely delimit entities that do not represent actual evolutionary lineages.

  6. Why conventional detection methods fail in identifying the existence of contamination events.

    PubMed

    Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

    2016-04-15

    Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading.

  7. Why conventional detection methods fail in identifying the existence of contamination events.

    PubMed

    Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

    2016-04-15

    Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading. PMID:26905801

  8. A Simple Candle Filter Safeguard Device

    SciTech Connect

    Hurley, J.P.; Henderson, A.K.; Swanson, M.L.

    2002-09-18

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal utilization. Two main designs employ these turbines: those based on pressurized fluidized-bed combustors (PFBCs) and those based on integrated gasification combined cycles (IGCCs). In both designs, the suspended particulates, or dust, must be cleaned from the gas before it enters the turbine to prevent fouling and erosion of the blades. To produce the cleanest gas, barrier filters are being developed and are in commercial use. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the dust on the surface. The three main configurations are candle, cross-flow, and tube. Both candle and tube filters have been tested extensively. They are primarily composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer o n the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle, and individual elements can fail, allowing the particulates to pass through the hole left by the filter element and erode the turbine. Because of the possibility of occasional filter breakage, safeguard devices (SGDs) must be employed to prevent the dust streaming through broken filters from reaching the turbine. The Energy & Environmental Research Center (EERC) safeguard device is composed of three main parts: the ceramic substrate, the adhesive coating, and the safeguard device housing. This report describes the development and laboratory testing of each of those parts as well as the bench-scale performance of both types of complete SGDs.

  9. The CIRSE Retrievable IVC Filter Registry: Retrieval Success Rates in Practice.

    PubMed

    Lee, M J; Valenti, D; de Gregorio, M A; Minocha, J; Rimon, U; Pellerin, O

    2015-12-01

    CIRSE established a registry of retrievable filter use with the primary aim of determining the success of IVC Filter retrieval and associated complications. Secondary endpoints included filter indications, imaging strategies before retrieval, filter dwell times, and anticoagulation status. A web-based electronic registry was hosted between 01/12/2010 and 30/06/2012. Data entry occurred at the date of IVC filter retrieval and included items such as filter type, indication for filter insertion, access route, dwell time, retrieval success, complications, reasons for failed retrieval, and anticoagulation status. 671 filter retrievals were entered (male:female 333:295, mean age 55, median 57). Retrieval data were not entered in 43/671 leaving 628 patients for analysis. The 4 commonest retrievable filters used were the Celect in 182 patients, the OPTEASE in 161, ALN in 120, and Gunther Tulip in 98. Filters were inserted for absolute indications 40%, relative indications in 31%, and prophylactic in 24%, with 5% missing. Mean filter dwell time was 90 days. Filters were successfully retrieved in 576/628 patients (92%). The mean dwell time for successful retrievals was 85 days versus 145 days for unsuccessful retrievals (p = 0.001). Major complications occurred in 2 patients (0.03%). In summary, the CIRSE retrievable filter registry demonstrates a retrieval rate of 92% across a range of filter types, with a low major complication rate, reflecting current practice. There is an increase in trend of retrievable filter use for relative and prophylactic indications. PMID:25933644

  10. Generic Kalman Filter Software

    NASA Technical Reports Server (NTRS)

    Lisano, Michael E., II; Crues, Edwin Z.

    2005-01-01

    The Generic Kalman Filter (GKF) software provides a standard basis for the development of application-specific Kalman-filter programs. Historically, Kalman filters have been implemented by customized programs that must be written, coded, and debugged anew for each unique application, then tested and tuned with simulated or actual measurement data. Total development times for typical Kalman-filter application programs have ranged from months to weeks. The GKF software can simplify the development process and reduce the development time by eliminating the need to re-create the fundamental implementation of the Kalman filter for each new application. The GKF software is written in the ANSI C programming language. It contains a generic Kalman-filter-development directory that, in turn, contains a code for a generic Kalman filter function; more specifically, it contains a generically designed and generically coded implementation of linear, linearized, and extended Kalman filtering algorithms, including algorithms for state- and covariance-update and -propagation functions. The mathematical theory that underlies the algorithms is well known and has been reported extensively in the open technical literature. Also contained in the directory are a header file that defines generic Kalman-filter data structures and prototype functions and template versions of application-specific subfunction and calling navigation/estimation routine code and headers. Once the user has provided a calling routine and the required application-specific subfunctions, the application-specific Kalman-filter software can be compiled and executed immediately. During execution, the generic Kalman-filter function is called from a higher-level navigation or estimation routine that preprocesses measurement data and post-processes output data. The generic Kalman-filter function uses the aforementioned data structures and five implementation- specific subfunctions, which have been developed by the user on

  11. Contactor/filter improvements

    DOEpatents

    Stelman, D.

    1988-06-30

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream is described. The filter includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. A cover screen isolates the filter element from contact with the moving granular bed. In one embodiment, the granular material is comprised of porous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses. 6 figs.

  12. Concentric Split Flow Filter

    NASA Technical Reports Server (NTRS)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  13. A backtracking algorithm that deals with particle filter degeneracy

    NASA Astrophysics Data System (ADS)

    Baarsma, Rein; Schmitz, Oliver; Karssenberg, Derek

    2016-04-01

    Particle filters are an excellent way to deal with stochastic models incorporating Bayesian data assimilation. While they are computationally demanding, the particle filter has no problem with nonlinearity and it accepts non-Gaussian observational data. In the geoscientific field it is this computational demand that creates a problem, since dynamic grid-based models are often already quite computationally demanding. As such it is of the utmost importance to keep the amount of samples in the filter as small as possible. Small sample populations often lead to filter degeneracy however, especially in models with high stochastic forcing. Filter degeneracy renders the sample population useless, as the population is no longer statistically informative. We have created an algorithm in an existing data assimilation framework that reacts to and deals with filter degeneracy based on Spiller et al. [2008]. During the Bayesian updating step of the standard particle filter, the algorithm tests the sample population for filter degeneracy. If filter degeneracy has occurred, the algorithm resets to the last time the filter did work correctly and recalculates the failed timespan of the filter with an increased sample population. The sample population is then reduced to its original size and the particle filter continues as normal. This algorithm was created in the PCRaster Python framework, an open source tool that enables spatio-temporal forward modelling in Python [Karssenberg et al., 2010] . The framework already contains several data assimilation algorithms, including a standard particle filter and a Kalman filter. The backtracking particle filter algorithm has been added to the framework, which will make it easy to implement in other research. The performance of the backtracking particle filter is tested against a standard particle filter using two models. The first is a simple nonlinear point model, and the second is a more complex geophysical model. The main testing

  14. Filter vapor trap

    DOEpatents

    Guon, Jerold

    1976-04-13

    A sintered filter trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The filter is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the filter leaves are precoated with a natrophobic coating such as tetracosane.

  15. Hybrid Filter Membrane

    NASA Technical Reports Server (NTRS)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  16. Practical alarm filtering

    SciTech Connect

    Bray, M.; Corsberg, D. )

    1994-02-01

    An expert system-based alarm filtering method is described which prioritizes and reduces the number of alarms facing an operator. This patented alarm filtering methodology was originally developed and implemented in a pressurized water reactor, and subsequently in a chemical processing facility. Both applications were in LISP and both were successful. In the chemical processing facility, for instance, alarm filtering reduced the quantity of alarm messages by 90%. 6 figs.

  17. Technical Error During Deployment Leads to Vena Cava Filter Migration and Massive Pulmonary Embolism

    SciTech Connect

    Fotiadis, Nikolas I. Sabharwal, Tarun; Dourado, Renato; Fikrat, Shabbo; Adam, Andreas

    2008-07-15

    The Guenther Tulip vena cava filter is a safe, effective, well-established device for pulmonary embolism prophylaxis. We report a patient in whom there was migration of the filter to the right atrium, 2 weeks after insertion, caused by a technical error during deployment. An attempt to retrieve the filter percutaneously failed, necessitating removal at open-heart surgery. The potential causes of migration are described and the lessons learned from this unusual case are outlined.

  18. Disorganized junior doctors fail the MRCP (UK).

    PubMed

    Stanley, Adrian G; Khan, Khalid M; Hussain, Walayat; Tweed, Michael

    2006-02-01

    Career progression during undergraduate and early postgraduate years is currently determined by successfully passing examinations. Both academic factors (secondary school examination results, learning style and training opportunities) and non-academic factors (maturity, ethnic origin, gender and motivation) have been identified as predicting examination outcome. Few studies have examined organization skills. Disorganized medical students are more likely to perform poorly in end-of-year examinations but this observation has not been examined in junior doctors. This study asked whether organization skills relate to examination outcome amongst junior doctors taking the clinical Part II examination for the Membership of the Royal College of Physicians (Practical Assessment of Clinical Examination Skills). The study was conducted prospectively at four consecutive clinical courses that provided clinical teaching and practice to prepare trainees for the examination. Arrival time at registration for the course was the chosen surrogate for organization skills. Trainees were advised that they should arrive promptly at 8.00 a.m. for registration and it was explained that the course would start at 8.30 a.m. Recorded arrival times were compared with the pass lists published by the Royal College of Physicians. The mean arrival time was 8.17 a.m. A total of 81 doctors (53.3%) passed the examination with a mean arrival time of 8.14 a.m. However, 71 doctors failed the exam and arrived, on average, six minutes later than doctors who passed (p?=?0.006). Better-prepared junior doctors were more likely to pass the final examination. Arriving on time represents a composite of several skills involved in the planning of appropriate travel arrangements and is therefore a valid marker of organization skills and preparation. This novel study has shown that good time-keeping skills are positively associated with examination outcome. PMID:16627323

  19. Revision of failed humeral head resurfacing arthroplasty

    PubMed Central

    Streubel, Philipp N.; Simone, Juan P.; Cofield, Robert H.; Sperling, John W.

    2016-01-01

    Purpose: The purpose of this study is to assess the outcomes of a consecutive series of patients who underwent revision surgery after humeral head resurfacing (HHR). Our joint registry was queried for all patients who underwent revision arthroplasty for failed HHR at our institution from 2005 to 2010. Eleven consecutive patients (average age 54 years; range 38-69 years) that underwent revision of 11 resurfacing arthroplasties were identified. The primary indication for resurfacing had been osteoarthritis in six, glenoid dysplasia in two, a chondral lesion in two, and postinstability arthropathy in one patient. The indication for revision was pain in 10 and infection in one patient. Seven patients had undergone an average of 1.9 surgeries prior to resurfacing (range 1-3). Materials and Methods: All patients were revised to stemmed arthroplasties, including one hemiarthroplasty, two reverse, and eight anatomic total shoulder arthroplasties at a mean 33 months after primary resurfacing (range 10-131 months). A deltopectoral approach was used in seven patients; four patients required an anteromedial approach due to severe scarring. Subscapularis attenuation was found in four cases, two of which required reverse total shoulder arthroplasty. Bone grafting was required in one glenoid and three humeri. Results: At a mean follow-up of 3.5 years (range 1.6-6.9 years), modified Neer score was rated as satisfactory in five patients and unsatisfactory in six. Abduction and external rotation improved from 73° to 88° (P = 0.32) and from 23° to 32° (P = 0.28) respectively. Reoperation was required in two patients, including one hematoma and one revision for instability. Conclusion: Outcomes of revision of HHR arthroplasty in this cohort did not improve upon those reported for revision of stemmed humeral implants. A comparative study would be required to allow for definitive conclusions to be made. PMID:26980986

  20. Nanofiber Filters Eliminate Contaminants

    NASA Technical Reports Server (NTRS)

    2009-01-01

    With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

  1. Linear phase compressive filter

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

  2. Linear phase compressive filter

    DOEpatents

    McEwan, T.E.

    1995-06-06

    A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line. 2 figs.

  3. Filter construction and design.

    PubMed

    Jornitz, Maik W

    2006-01-01

    Sterilizing and pre-filters are manufactured in different formats and designs. The criteria for the specific designs are set by the application and the specifications of the filter user. The optimal filter unit or even system requires evaluation, such as flow rate, throughput, unspecific adsorption, steam sterilizability and chemical compatibility. These parameters are commonly tested within a qualification phase, which ensures that an optimal filter design and combination finds its use. If such design investigations are neglected it could be costly in the process scale. PMID:16570863

  4. Filter holder and gasket assembly for candle or tube filters

    DOEpatents

    Lippert, T.E.; Alvin, M.A.; Bruck, G.J.; Smeltzer, E.E.

    1999-03-02

    A filter holder and gasket assembly are disclosed for holding a candle filter element within a hot gas cleanup system pressure vessel. The filter holder and gasket assembly includes a filter housing, an annular spacer ring securely attached within the filter housing, a gasket sock, a top gasket, a middle gasket and a cast nut. 9 figs.

  5. Filter holder and gasket assembly for candle or tube filters

    DOEpatents

    Lippert, Thomas Edwin; Alvin, Mary Anne; Bruck, Gerald Joseph; Smeltzer, Eugene E.

    1999-03-02

    A filter holder and gasket assembly for holding a candle filter element within a hot gas cleanup system pressure vessel. The filter holder and gasket assembly includes a filter housing, an annular spacer ring securely attached within the filter housing, a gasket sock, a top gasket, a middle gasket and a cast nut.

  6. Sediments fail to record geomagnetic transitions

    NASA Astrophysics Data System (ADS)

    Valet, Jean-Pierre; Meynadier, Laure; Bassinot, Franck; Simon, Quentin; Thouveny, Nicolas

    2016-04-01

    We have studied four records of the last Matuyama-Brunhes reversal from sediment cores from the equatorial Indian Ocean, west equatorial Pacific Ocean and North Atlantic Ocean with deposition rates of 4cm/ka and 2cm/ka for one equatorial core. All measurements were performed using 8cc cubic samples. In three records the demagnetization diagrams of the transitional samples are of bad quality. In the best samples the characteristic component of magnetization is defined with a large error that is reflected by an increase of the MAD value by at least a factor 10 with respect to non-transitional samples. Although not being frequently reported in papers which tend to exhibit the best demagnetization diagrams, this behavior is actually typical of most transitions studied in sedimentary sequences and somehow questions the reliability of the records. It is frequently considered that failure to isolate the initial magnetization component is due to weakly magnetized transitional samples with magnetization about ten times lower than outside the reversal. However, the magnetization intensity of transitional samples is much stronger in two of the present cores than the non-transitional samples of the other cores. The VGP paths that were tentatively derived from these transitions are quite complex and very different from each other. After rescaling all results to the same resolution the length of the transitional intervals remains different between each core suggesting that different magnetization processes were at work and yielded different records of the rapid field changes during the transition. Because similar magnetic grains recorded different directions, demagnetization fails to isolate a characteristic component. The sediment from west equatorial Pacific is an interesting exception with nice univectorial transitional diagrams decreasing towards the origin. The inclination remains close to zero, while the declination rotates smoothly between the two polarities. As a

  7. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-01-01

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  8. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-12-31

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  9. Active rejector filter

    SciTech Connect

    Kuchinskii, A.G.; Pirogov, S.G.; Savchenko, V.M.; Yakushev, A.K.

    1985-01-01

    This paper describes an active rejector filter for suppressing noise signals in the frequency range 50-100 Hz and for extracting a vlf information signal. The filter has the following characteristics: a high input impedance, a resonant frequency of 75 Hz, a Q of 1.25, and an attenuation factor of 53 dB at resonant frequency.

  10. Weighted guided image filtering.

    PubMed

    Li, Zhengguo; Zheng, Jinghong; Zhu, Zijian; Yao, Wei; Wu, Shiqian

    2015-01-01

    It is known that local filtering-based edge preserving smoothing techniques suffer from halo artifacts. In this paper, a weighted guided image filter (WGIF) is introduced by incorporating an edge-aware weighting into an existing guided image filter (GIF) to address the problem. The WGIF inherits advantages of both global and local smoothing filters in the sense that: 1) the complexity of the WGIF is O(N) for an image with N pixels, which is same as the GIF and 2) the WGIF can avoid halo artifacts like the existing global smoothing filters. The WGIF is applied for single image detail enhancement, single image haze removal, and fusion of differently exposed images. Experimental results show that the resultant algorithms produce images with better visual quality and at the same time halo artifacts can be reduced/avoided from appearing in the final images with negligible increment on running times. PMID:25415986

  11. Sintered composite filter

    DOEpatents

    Bergman, W.

    1986-05-02

    A particulate filter medium formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers is described. Preferred composition is about 40 vol.% quartz and about 60 vol.% stainless steel fibers. The media is sintered at about 1100/sup 0/C to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550/sup 0/C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  12. Sub-micron filter

    DOEpatents

    Tepper, Frederick; Kaledin, Leonid

    2009-10-13

    Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite filter with other fibers or particles they can filter bacteria and nano size particulates such as viruses and colloidal particles at high flux through the filter. Such filters can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of filtering sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.

  13. Interior's Climate Science Centers: Focus or Fail

    NASA Astrophysics Data System (ADS)

    Udall, B.

    2012-12-01

    After a whirlwind two years of impressive and critical infrastructure building, the Department of Interior's Climate Science Centers are now in a position to either succeed or fail. The CSCs have a number of difficult structural problems including too many constituencies relative to the available resources, an uneasy relationship among many of the constituencies including the DOI agencies themselves, a need to do science in a new, difficult and non-traditional way, and a short timeframe to produce useful products. The CSCs have built a broad and impressive network of scientists and stakeholders. These entities include science providers of the universities and the USGS, and decision makers from the states, tribes, DOI land managers and other federal agencies and NGOs. Rather than try to support all of these constituencies the CSCs would be better served by refocusing on a core mission of supporting DOI climate related decision making. The CSCs were designed to service the climate science needs of DOI agencies, many of which lost their scientific capabilities in the 1990s due to a well-intentioned but ultimately harmful re-organization at DOI involving the now defunct National Biological Survey. Many of these agencies would like to have their own scientists, have an uneasy relationship with the nominal DOI science provider, the USGS, and don't communicate effectively among themselves. The CSCs must not succumb to pursuing science in either the traditional mode of the USGS or in the traditional mode of the universities, or worse, both of them. These scientific partners will need to be flexible, learn how to collaborate and should expect to see fewer resources. Useful CSC processes and outputs should start with the recommendations of the 2009 NRC Report Informing Decisions in a Changing Climate: (1) begin with users' needs; (2) give priority to process over products; (3) link information producers and users; (4) build connections across disciplines and organizations

  14. Technology development: HEPA filter service life test plan

    SciTech Connect

    Kirchner, K.N.; Cummings, K.G.; Leck, W.C.; Fretthold, J.K.

    1995-05-31

    Rocky Flats Environmental Technology Site (the Site) has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and also during potential design-based accidents. The operational integrity of the HEPA filter plenums is essential to maintaining the margins of safety as required by building specific Final Safety Analysis Reports (FSARS) for protection of the public and environment. An Unreviewed Safety Question Determination (USQD), USDQ-RFP94.0615-ARS, was conducted in 1994 addressing the potential inadequacy of the safety envelope for Protected Area building HEPA plenums. While conducting this USQD, questions were raised concerning the maximum service life criteria for HEPA filters. Accident scenarios in existing FSARs identify conditions that could potentially cause plugging or damage of down stream HEPA filters as a result of impaction from failed filters. Additionally, available data indicates that HEPA filters experience structural degradation due to the effects of age. The Unresolved Safety Question (USQ) compensatory measures thus require testing and analysis of used HEPA filters in order to determine and implement service life criteria.

  15. Ceramic fiber reinforced filter

    DOEpatents

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  16. Solc filter engineering

    NASA Technical Reports Server (NTRS)

    Rosenberg, W. J.; Title, A. M.

    1982-01-01

    A Solc (1965) filter configuration is presented which is both tunable and spectrally variable, since it possesses an adjustable bandwidth, and which although less efficient than a Lyot filter is attractive because of its spectral versatility. The lossless design, using only an entrance and exit polarizer, improves throughput generally and especially in the IR, where polarizers are less convenient than dichroic sheet polarizers. Attention is given to the transmission profiles of Solc filters with different numbers of elements and split elements, as well as their mechanical design features.

  17. Multilevel filtering elliptic preconditioners

    NASA Technical Reports Server (NTRS)

    Kuo, C. C. Jay; Chan, Tony F.; Tong, Charles

    1989-01-01

    A class of preconditioners is presented for elliptic problems built on ideas borrowed from the digital filtering theory and implemented on a multilevel grid structure. They are designed to be both rapidly convergent and highly parallelizable. The digital filtering viewpoint allows the use of filter design techniques for constructing elliptic preconditioners and also provides an alternative framework for understanding several other recently proposed multilevel preconditioners. Numerical results are presented to assess the convergence behavior of the new methods and to compare them with other preconditioners of multilevel type, including the usual multigrid method as preconditioner, the hierarchical basis method and a recent method proposed by Bramble-Pasciak-Xu.

  18. HEPA filter jointer

    SciTech Connect

    Hill, D.; Martinez, H.E.

    1998-02-01

    A HEPA filter jointer system was created to remove nitrate contaminated wood from the wooden frames of HEPA filters that are stored at the Rocky Flats Plant. A commercial jointer was chosen to remove the nitrated wood. The chips from the wood removal process are in the right form for caustic washing. The jointer was automated for safety and ease of operation. The HEPA filters are prepared for jointing by countersinking the nails with a modified air hammer. The equipment, computer program, and tests are described in this report.

  19. Preliminary studies to determine the shelf life of HEPA filters. Revision 1

    SciTech Connect

    Gilbert, H.; Fretthold, J.K.; Rainer, F.; Bergman, W.; Beason, D.

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  20. DEVELOPMENT OF AN ADHESIVE CANDLE FILTER SAFEGUARD DEVICE

    SciTech Connect

    John P. Hurley; Ann K. Henderson; Jan W. Nowok; Michael L. Swanson

    2002-01-01

    In order to reach the highest possible efficiencies in a coal-fired turbine-based power system, the turbine should be directly fired with the products of coal conversion. Two main types of systems employ these turbines: those based on pressurized fluidized-bed combustors and those based on integrated gasification combined cycles. In both systems, suspended particulates must be cleaned from the gas stream before it enters the turbine so as to prevent fouling and erosion of the turbine blades. To produce the cleanest gas, barrier filters are being developed and are in use in several facilities. Barrier filters are composed of porous, high-temperature materials that allow the hot gas to pass but collect the particulates on the surface. The three main configurations of the barrier filters are candle, cross-flow, and tube filters. Both candle and tube filters have been tested extensively. They are composed of coarsely porous ceramic that serves as a structural support, overlain with a thin, microporous ceramic layer on the dirty gas side that serves as the primary filter surface. They are highly efficient at removing particulate matter from the gas stream and, because of their ceramic construction, are resistant to gas and ash corrosion. However, ceramics are brittle and individual elements can fail, allowing particulates to pass through the hole left by the filter element and erode the turbine. Preventing all failure of individual ceramic filter elements is not possible at the present state of development of the technology. Therefore, safeguard devices (SGDs) must be employed to prevent the particulates streaming through occasional broken filters from reaching the turbine. However, the SGD must allow for the free passage of gas when it is not activated. Upon breaking of a filter, the SGD must either mechanically close or quickly plug with filter dust to prevent additional dust from reaching the turbine. Production of a dependable rapidly closing autonomous mechanical

  1. Active-R filter

    DOEpatents

    Soderstrand, Michael A.

    1976-01-01

    An operational amplifier-type active filter in which the only capacitor in the circuit is the compensating capacitance of the operational amplifiers, the various feedback and coupling elements being essentially solely resistive.

  2. Parallel Subconvolution Filtering Architectures

    NASA Technical Reports Server (NTRS)

    Gray, Andrew A.

    2003-01-01

    These architectures are based on methods of vector processing and the discrete-Fourier-transform/inverse-discrete- Fourier-transform (DFT-IDFT) overlap-and-save method, combined with time-block separation of digital filters into frequency-domain subfilters implemented by use of sub-convolutions. The parallel-processing method implemented in these architectures enables the use of relatively small DFT-IDFT pairs, while filter tap lengths are theoretically unlimited. The size of a DFT-IDFT pair is determined by the desired reduction in processing rate, rather than on the order of the filter that one seeks to implement. The emphasis in this report is on those aspects of the underlying theory and design rules that promote computational efficiency, parallel processing at reduced data rates, and simplification of the designs of very-large-scale integrated (VLSI) circuits needed to implement high-order filters and correlators.

  3. HEPA air filter (image)

    MedlinePlus

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  4. Improved optical filter

    NASA Technical Reports Server (NTRS)

    Title, A. M.

    1978-01-01

    Filter includes partial polarizer between birefrigent elements. Plastic film on partial polarizer compensates for any polarization rotation by partial polarizer. Two quarter-wave plates change incident, linearly polarized light into elliptically polarized light.

  5. Erika's Stories: Literacy Solutions for a Failing Middle School Student

    ERIC Educational Resources Information Center

    Ma'ayan, Hadar Dubowsky

    2010-01-01

    Erika was a failing student at a large urban public middle school. She was poor, Hispanic, bilingual, and had repeated fourth grade. She scored low on her standardized tests and was failing several subject areas. In class, Erika was a student who sat silently with her head on her desk, and rarely turned in any of her assignments. She was a…

  6. 75 FR 76262 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ85 Source of Income From Qualified Fails Charges AGENCY... temporary regulations which set forth the source of income attributable to qualified fails charges. The.... source income of foreign persons that is not effectively connected with the conduct of a trade...

  7. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  8. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  9. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Reconditioning failing quality peanuts. 996.50 Section... QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality and Handling Standards § 996.50 Reconditioning failing quality peanuts. (a) Lots of peanuts which have not...

  10. Anti-Glare Filters

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Glare from CRT screens has been blamed for blurred vision, eyestrain, headaches, etc. Optical Coating Laboratory, Inc. (OCLI) manufactures a coating to reduce glare which was used to coat the windows on the Gemini and Apollo spacecraft. In addition, OCLI offers anti-glare filters (Glare Guard) utilizing the same thin film coating technology. The coating minimizes brightness, provides enhanced contrast and improves readability. The filters are OCLI's first consumer product.

  11. Spatial filter issues

    SciTech Connect

    Murray, J.E.; Estabrook, K.G.; Milam, D.; Sell, W.D.; Van Wonterghem, R.M.; Feil, M.D.; Rubenchick, A.M.

    1996-12-09

    Experiments and calculations indicate that the threshold pressure in spatial filters for distortion of a transmitted pulse scales approximately as I{sup O.2} and (F{number_sign}){sup 2} over the intensity range from 10{sup 14} to 2xlO{sup 15} W/CM{sup 2} . We also demonstrated an interferometric diagnostic that will be used to measure the scaling relationships governing pinhole closure in spatial filters.

  12. Holographic interference filters

    NASA Astrophysics Data System (ADS)

    Diehl, Damon W.

    Holographic mirrors have wavelength-selection properties and thus qualify as a class of interference filters. Two theoretical methods for analyzing such structures are developed. The first method uses Hill's matrix method to yield closed-forms solutions in terms of the Floquet-Bloch waves within a periodic structure. A process is developed for implementing this solution method on a computer, using sparse-matrix memory allocation, numerical root-finding algorithms, and inverse-iteration techniques. It is demonstrated that Hill's matrix method is valid for the analysis of finite and multi-periodic problems. The second method of theoretical analysis is a transfer-matrix technique, which is herein termed thin-film decomposition. It is shown that the two methods of solution yield results that differ by, at worst, a fraction of a percent. Using both calculation techniques, a number of example problems are explored. Of key importance is the construction of a set of curves that are useful for the design and characterization of holographic interference filters. In addition to the theoretical development, methods are presented for the fabrication of holographic interference filters using DuPont HRF-800X001 photopolymer. Central to the exposure system is a frequency-stabilized, tunable dye laser. The types of filters fabricated include single-tone reflection filters, two types of multitone reflection filters, and reflection filters for infrared wavelengths. These filters feature index profiles that are not easily attainable through other fabrication methods. As a supplement to the body of the dissertation, the computer algorithms developed to implement Hill's matrix method and thin-film decomposition are also included as an appendix. Further appendices provide more information on Floquet's theorem and Hill's matrix method. A final appendix presents a design for an infrared laser spectrophotometer.

  13. Characterization and Failure Analysis of Ceramic Filters Utilized for Emission Control Coal Gasification

    SciTech Connect

    Daniel Mei; Jianren Zhou; Ziaul Huque

    1998-03-01

    Advanced integrated gasification combined cycle (IGCC) and pressurized fluidized bed combustion (PFBC) power system requires both hot gas desulfurization and particulate filtration to improve system thermal efficiency and overall performance. Therefore, effective high temperature ceramic filters are indispensable key component in both of the advanced IGCC and PFBC coal based power systems to perform hot gas cleanup work. To meet the environmental particulate emission requirements and improve thermal efficiency, ceramic filters are mainly utilized to cleanup the hot gas particulate to protect downstream heat exchanger and gas turbine components from fouling and corrosion. The mechanical integrity of ceramic filters and an efficient dust cake removal system are the key issues for hot gas cleanup systems. The filters must survive combined stresses due to mechanical, thermal, chemical and steam attack throughout normal operations (cold back pulse cleaning jets), unexpected excessive ash accumulation, and the start up and shut down conditions. To evaluate the design and performance of ceramic filters, different long term filter testing programs were conducted. To fulfill this purpose, two Advanced Particle Filter (APF) systems were complete at Tidd PFBC Demonstration Plant, in Brilliant, Ohio in late 1990 as part of the Department of Energy's (DOE) Clean Coal Technology Program. But the most undesirable thing ever happened was the sudden functional and physical failures of filters prior to its designed life time. In Tidd APF filter vessel, twenty eight (28) filters failed one time. Significant research effort has been carried out to find out the causes that led to the early failure of filters. In this work, the studies are emphasized on the possible failure causes analysis of rigid ceramic candle filters. The objectives of this program were to provide an systematic study on the characterization of filters, material laboratory analysis on filter micro-structure, the dust

  14. Simulating fail-stop in asynchronous distributed systems

    NASA Technical Reports Server (NTRS)

    Sabel, Laura; Marzullo, Keith

    1994-01-01

    The fail-stop failure model appears frequently in the distributed systems literature. However, in an asynchronous distributed system, the fail-stop model cannot be implemented. In particular, it is impossible to reliably detect crash failures in an asynchronous system. In this paper, we show that it is possible to specify and implement a failure model that is indistinguishable from the fail-stop model from the point of view of any process within an asynchronous system. We give necessary conditions for a failure model to be indistinguishable from the fail-stop model, and derive lower bounds on the amount of process replication needed to implement such a failure model. We present a simple one-round protocol for implementing one such failure model, which we call simulated fail-stop.

  15. Contactor/filter improvements

    DOEpatents

    Stelman, David

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  16. NICMOS Filter Wheel Test

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2009-07-01

    This is an engineering test {described in SMOV4 Activity Description NICMOS-04} to verify the aliveness, functionality, operability, and electro-mechanical calibration of the NICMOS filter wheel motors and assembly after NCS restart in SMOV4. This test has been designed to obviate concerns over possible deformation or breakage of the fitter wheel "soda-straw" shafts due to excess rotational drag torque and/or bending moments which may be imparted due to changes in the dewar metrology from warm-up/cool-down. This test should be executed after the NCS {and filter wheel housing} has reached and approximately equilibrated to its nominal operating temperature.Addition of visits G0 - G9 {9/9/09}: Ten visits copied from proposal 11868 {visits 20, 30, ..., 90, A0, B0}. Each visit moves two filter positions, takes lamp ON/OFF exposures and then moves back to the blank position. Visits G0, G1 and G2 will leave the filter wheels disabled. The remaining visits will leave the filter wheels enabled. There are sufficient in between times to allow for data download and analysis. In the case of problem is encountered, the filter wheels will be disabled through a real time command. The in between times are all set to 22-50 hours. It is preferable to have as short as possible in between time.

  17. Remotely serviced filter and housing

    DOEpatents

    Ross, Maurice J.; Zaladonis, Larry A.

    1988-09-27

    A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge using an overhead crane. The filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station.

  18. Gunther Tulip Retrievable Inferior Vena Caval Filters: Indications, Efficacy, Retrieval, and Complications

    SciTech Connect

    Looby, S.; Given, M.F.; Geoghegan, T.; McErlean, A.; Lee, M.J.

    2007-02-15

    Purpose. We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation. Method. A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonary embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%). Results. Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded. Discussion. The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.

  19. Edge-Aware BMA Filters.

    PubMed

    Guang Deng

    2016-01-01

    There has been continuous research in edge-aware filters which have found many applications in computer vision and image processing. In this paper, we propose a principled-approach for the development of edge-aware filters. The proposed approach is based on two well-established principles: 1) optimal parameter estimation and 2) Bayesian model averaging (BMA). Using this approach, we formulate the problem of filtering a pixel in a local pixel patch as an optimal estimation problem. Since a pixel belongs to multiple local patches, there are multiple estimates of the same pixel. We combine these estimates into a final estimate using BMA. We demonstrate the versatility of this approach by developing a family of BMA filters based on different settings of cost functions and log-likelihood and log-prior functions. We also present a new interpretation of the guided filter and develop a BMA guided filter which includes the guided filter as a special case. We show that BMA filters can produce similar smoothing results as those of the state-of-the-art edge-aware filters. Two BMA filters are computationally as efficient as the guided filter which is one of the fastest edge-aware filters. We also demonstrate that the BMA guided filter is better than the guided filter in preserving sharp edges. A new feature of the BMA guided filter is that the filtered image is similar to that produced by a clustering process.

  20. Remotely serviced filter and housing

    DOEpatents

    Ross, M.J.; Zaladonis, L.A.

    1987-07-22

    A filter system for a hot cell comprises a housing adapted for input of air or other gas to be filtered, flow of the air through a filter element, and exit of filtered air. The housing is tapered at the top to make it easy to insert a filter cartridge holds the filter element while the air or other gas is passed through the filter element. Captive bolts in trunnion nuts are readily operated by electromechanical manipulators operating power wrenches to secure and release the filter cartridge. The filter cartridge is adapted to make it easy to change a filter element by using a master-slave manipulator at a shielded window station. 6 figs.

  1. Anti-clogging filter system

    DOEpatents

    Brown, Erik P.

    2015-05-19

    An anti-clogging filter system for filtering a fluid containing large particles and small particles includes an enclosure with at least one individual elongated tubular filter element in the enclosure. The individual elongated tubular filter element has an internal passage, a closed end, an open end, and a filtering material in or on the individual elongated tubular filter element. The fluid travels through the open end of the elongated tubular element and through the internal passage and through the filtering material. An anti-clogging element is positioned on or adjacent the individual elongated tubular filter element and provides a fluid curtain that preferentially directs the larger particulates to one area of the filter material allowing the remainder of the filter material to remain more efficient.

  2. An IIR median hybrid filter

    NASA Technical Reports Server (NTRS)

    Bauer, Peter H.; Sartori, Michael A.; Bryden, Timothy M.

    1992-01-01

    A new class of nonlinear filters, the so-called class of multidirectional infinite impulse response median hybrid filters, is presented and analyzed. The input signal is processed twice using a linear shift-invariant infinite impulse response filtering module: once with normal causality and a second time with inverted causality. The final output of the MIMH filter is the median of the two-directional outputs and the original input signal. Thus, the MIMH filter is a concatenation of linear filtering and nonlinear filtering (a median filtering module). Because of this unique scheme, the MIMH filter possesses many desirable properties which are both proven and analyzed (including impulse removal, step preservation, and noise suppression). A comparison to other existing median type filters is also provided.

  3. Filters for cathodic arc plasmas

    DOEpatents

    Anders, Andre; MacGill, Robert A.; Bilek, Marcela M. M.; Brown, Ian G.

    2002-01-01

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  4. Childhood obesity: parents fail to recognise, general practitioners fail to act.

    PubMed

    White, A; O'Brien, B; Houlihan, T; Darker, C; O'Shea, B

    2012-01-01

    General Practitioners (GPs) have an important role to play in recognition of and intervention against childhood obesity in Ireland. Data were collected prospectively on a cohort of children aged 4-14 and their parents (n = 101 pairs) who attended consecutively to a semi-rural group general practice. Parents estimated their child's weight status. Actual weight status was determined for both parent and child using the United States Centres' for Disease Control's BMI-for-age references. 15 (14.9%) of the children and 49 (51.6%) of the parents were overweight or obese. While 71 (95.5%) of normal weight status children were correctly identified, parents showed poor concordance in identifying their children as overweight 2 (18.2%) or obese 0 (0%). BMI was only evidently recorded in the clinical records of 1 out of 15 cases of overweight children identified. With parents failing to recognise childhood obesity, GPs have a responsibility in tackling this problem at a family level.

  5. Earthquake recurrence models fail when earthquakes fail to reset the stress field

    USGS Publications Warehouse

    Tormann, Thessa; Wiemer, Stefan; Hardebeck, Jeanne L.

    2012-01-01

    Parkfield's regularly occurring M6 mainshocks, about every 25 years, have over two decades stoked seismologists' hopes to successfully predict an earthquake of significant size. However, with the longest known inter-event time of 38 years, the latest M6 in the series (28 Sep 2004) did not conform to any of the applied forecast models, questioning once more the predictability of earthquakes in general. Our study investigates the spatial pattern of b-values along the Parkfield segment through the seismic cycle and documents a stably stressed structure. The forecasted rate of M6 earthquakes based on Parkfield's microseismicity b-values corresponds well to observed rates. We interpret the observed b-value stability in terms of the evolution of the stress field in that area: the M6 Parkfield earthquakes do not fully unload the stress on the fault, explaining why time recurrent models fail. We present the 1989 M6.9 Loma Prieta earthquake as counter example, which did release a significant portion of the stress along its fault segment and yields a substantial change in b-values.

  6. Filter component assessment

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Diaz, E.S.; Smeltzer, E.W.

    1995-11-01

    The objectives of this program are to provide a more ruggedized filter system that utilizes porous ceramic filters which have improved resistance to damage resulting from crack propagation, thermal fatigue and/or thermal excursions during plant or process transient conditions, and/or mechanical ash bridging events within the candle filter array. As part of the current Phase 1, Task 1, effort of this program, Westinghouse is evaluating the filtration characteristics, mechanical integrity, and corrosion resistance of the following advanced or second generation candle filters for use in advanced coal-fired process applications: 3M CVI-SiC composite--chemical vapor infiltration of silicon carbide into an aluminosilicate Nextel{trademark} 312 fiber preform; DuPont PRD-66--filament wound candle filter structure containing corundum, cordierite, cristobalite, and mullite; DuPont SiC-SiC--chemical infiltration of silicon carbide into a silicon carbide Nicalon{trademark} fiber mat or felt preform; and IF and P Fibrosic{trademark}--vacuum infiltrated oxide-based chopped fibrous matrix. Results to date are presented.

  7. Filter cake characterization studies

    SciTech Connect

    Newby, R.A.; Smeltzer, E.E.; Alvin, M.A.; Lippert, T.E.

    1995-11-01

    The Westinghouse Electric Corporation, Science & Technology Center is developing an Integrated Low Emissions Cleanup (ILEC) concept for high-temperature gas cleaning to meet environmental standards, as well as to provide gas turbine protection. The ILEC system is a ceramic barrier hot gas filter (HGF) that removes particulate while simultaneously contributing to the control of sulfur, alkali, and potentially other contaminants in high-temperature, high-pressure fuel gases, or combustion gases. The gas-phase contaminant removal is performed by sorbent particles injected into the HGF. The overall objective of this program is to demonstrate, at a bench scale, the technical feasibility of the ILEC concept for multi-contaminant control, and to provide test data applicable to the design of subsequent field tests. The program has conducted ceramic barrier filter testing under simulated PFBC conditions to resolve issues relating to filter cake permeability, pulse cleaning, and filter cake additive performance. ILEC testing has also been performed to assess the potential for in-filter sulfur and alkali removal.

  8. Disinfecting Filters For Recirculated Air

    NASA Technical Reports Server (NTRS)

    Pilichi, Carmine A.

    1992-01-01

    Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

  9. DOE HEPA filter test program

    SciTech Connect

    1998-05-01

    This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL).

  10. Filters for Submillimeter Electromagnetic Waves

    NASA Technical Reports Server (NTRS)

    Berdahl, C. M.

    1986-01-01

    New manufacturing process produces filters strong, yet have small, precise dimensions and smooth surface finish essential for dichroic filtering at submillimeter wavelengths. Many filters, each one essentially wafer containing fine metal grid made at same time. Stacked square wires plated, fused, and etched to form arrays of holes. Grid of nickel and tin held in brass ring. Wall thickness, thickness of filter (hole depth) and lateral hole dimensions all depend upon operating frequency and filter characteristics.

  11. Stack filter classifiers

    SciTech Connect

    Porter, Reid B; Hush, Don

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  12. Failure to fail: assessing nursing students' competence during practice placements.

    PubMed

    Rutkowski, Krzysztof

    The aim of this article is to provide a critical overview of the issues relating to the reluctance of registered nurses or mentors to fail students in their competencies and to identify possible causes for this at the practice level.

  13. Council tax precept failed to cover cost of NLW.

    PubMed

    2016-08-01

    Charging residents extra council tax to help pay for social care is insufficient to cover current funding gaps and has failed to cover the cost of the national living wage (NLW), a report warns. PMID:27573947

  14. DEVELOPMENT OF A CANDLE FILTER FAILURE SAFEGUARD DEVICE

    SciTech Connect

    Todd R. Snyder

    2002-03-29

    The full-flow mechanical safeguard device (FFMSGD) has been developed under contract to the National Energy Technology Laboratory (NETL) to address problems with the reliability of ceramic candle filter elements installed on high-temperature, high-pressure (HTHP) Hot Gas Cleanup (HGCU) filters. Although systems candle filters are expected to perform satisfactorily when in good operating condition, the failure of even a single filter element can increase the filter system outlet dust loading enough to potentially damage gas turbine blades, contaminate other downstream processes, and limit the availability of the power system. Filter failure safeguard devices that are installed on each individual candle filter element are envisioned as a guarantee of a candle filter system's ability to withstand some number of element failures and continue operation without these negative consequences. The intention of the FFMSGD is to provide this guarantee without incurring any significant pressure drop penalty or constraining the filter system's reverse-pulse cleaning procedures. The FFMSGD provides a clear flow path for filtered and reverse-flow cleaning gases when its filter element is intact, and activates to provide a positive mechanical seal against gas flow in either direction when its filter element breaks or fails. This activation is induced by the increase in the flow rate of gas through the device in event of filter failure. The FFMSGD is designed to be easily removed and reconditioned when the filter system is taken off line for routine maintenance. This report is intended to be issued with a companion appendix. As instructed in Section J.12 of Contract No. DE-AC26-99FT40678, all the restricted, proprietary, and patentable information (not yet disclosed through the patent application process) related to the FFMSGD and its evaluation under this contract has been included only in the appendix. This Final Report, which is available to the public, contains background

  15. Electronically tuned optical filters

    NASA Technical Reports Server (NTRS)

    Castellano, J. A.; Pasierb, E. F.; Oh, C. S.; Mccaffrey, M. T.

    1972-01-01

    A detailed account is given of efforts to develop a three layer, polychromic filter that can be tuned electronically. The operation of the filter is based on the cooperative alignment of pleochroic dye molecules by nematic liquid crystals activated by electric fields. This orientation produces changes in the optical density of the material and thus changes in the color of light transmitted through the medium. In addition, attempts to improve materials and devices which employ field induced changes of a cholesteric to a nematic liquid crystal are presented.

  16. Failed tracheal intubation during obstetric general anaesthesia: a literature review.

    PubMed

    Kinsella, S M; Winton, A L; Mushambi, M C; Ramaswamy, K; Swales, H; Quinn, A C; Popat, M

    2015-11-01

    We reviewed the literature on obstetric failed tracheal intubation from 1970 onwards. The incidence remained unchanged over the period at 2.6 (95% CI 2.0 to 3.2) per 1000 anaesthetics (1 in 390) for obstetric general anaesthesia and 2.3 (95% CI 1.7 to 2.9) per 1000 general anaesthetics (1 in 443) for caesarean section. Maternal mortality from failed intubation was 2.3 (95% CI 0.3 to 8.2) per 100000 general anaesthetics for caesarean section (one death per 90 failed intubations). Maternal deaths occurred from aspiration or hypoxaemia secondary to airway obstruction or oesophageal intubation. There were 3.4 (95% CI 0.7 to 9.9) front-of-neck airway access procedures (surgical airway) per 100000 general anaesthetics for caesarean section (one procedure per 60 failed intubations), usually carried out as a late rescue attempt with poor maternal outcomes. Before the late 1990s, most cases were awakened after failed intubation; since the late 1990s, general anaesthesia has been continued in the majority of cases. When general anaesthesia was continued, a laryngeal mask was usually used but with a trend towards use of a second-generation supraglottic airway device. A prospective study of obstetric general anaesthesia found that transient maternal hypoxaemia occurred in over two-thirds of cases of failed intubation, usually without sequelae. Pulmonary aspiration occurred in 8% but the rate of maternal intensive care unit admission after failed intubation was the same as that after uneventful general anaesthesia. Poor neonatal outcomes were often associated with preoperative fetal compromise, although failed intubation and lowest maternal oxygen saturation were independent predictors of neonatal intensive care unit admission.

  17. National intelligence estimates and the Failed State Index.

    PubMed

    Voracek, Martin

    2013-10-01

    Across 177 countries around the world, the Failed State Index, a measure of state vulnerability, was reliably negatively associated with the estimates of national intelligence. Psychometric analysis of the Failed State Index, compounded of 12 social, economic, and political indicators, suggested factorial unidimensionality of this index. The observed correspondence of higher national intelligence figures to lower state vulnerability might arise through these two macro-level variables possibly being proxies of even more pervasive historical and societal background variables that affect both.

  18. Digital hum filtering

    USGS Publications Warehouse

    Knapp, R.W.; Anderson, N.L.

    1994-01-01

    Data may be overprinted by a steady-state cyclical noise (hum). Steady-state indicates that the noise is invariant with time; its attributes, frequency, amplitude, and phase, do not change with time. Hum recorded on seismic data usually is powerline noise and associated higher harmonics; leakage from full-waveform rectified cathodic protection devices that contain the odd higher harmonics of powerline frequencies; or vibrational noise from mechanical devices. The fundamental frequency of powerline hum may be removed during data acquisition with the use of notch filters. Unfortunately, notch filters do not discriminate signal and noise, attenuating both. They also distort adjacent frequencies by phase shifting. Finally, they attenuate only the fundamental mode of the powerline noise; higher harmonics and frequencies other than that of powerlines are not removed. Digital notch filters, applied during processing, have many of the same problems as analog filters applied in the field. The method described here removes hum of a particular frequency. Hum attributes are measured by discrete Fourier analysis, and the hum is canceled from the data by subtraction. Errors are slight and the result of the presence of (random) noise in the window or asynchrony of the hum and data sampling. Error is minimized by increasing window size or by resampling to a finer interval. Errors affect the degree of hum attenuation, not the signal. The residual is steady-state hum of the same frequency. ?? 1994.

  19. Filter Component Assessment

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Diaz, E.S.; Smeltzer, E.E.

    1996-12-31

    Advanced particulate filtration systems are currently being developed at Westinghouse for use in both coal-fired Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) systems. To date, Westinghouse has demonstrated 5855 hours of successful operation of first generation monolithic filter elements in PFBC applications when ash bridging or process thermal transient excursions are avoided. Alternate advanced monolithic and second generation fiber reinforced, filament wound and vacuum infiltrated filters are also being developed which are considered to have enhanced high temperature creep resistance, improved fracture toughness, or enhanced thermal shock characteristics, respectively. Mechanical and component fabrication improvements, as well as degradation mechanisms for each filter element have been identified by Westinghouse during exposure to simulated PFBC operating conditions and alkali-containing steam/air environments. Additional effort is currently being focused on determining the stability of the advanced monolithic high temperature creep resistant clay bonded silicon carbide (SiC) materials, alumina/mullite, and chemically vapor infiltrated (CVI) SiC materials during operation in the Westinghouse Advanced Particulate Filtration (W-APF) system at Foster Wheeler`s pressurized circulating fluidized-bed combustion (PCFBC) test facility in Karhula, Finland. Select advanced filter materials are being defined for additional long-term exposure in integrated gasification combined cycle (IGCC) gas streams. The results of these efforts are summarized in this paper. 6 refs., 7 figs., 11 tabs.

  20. Ceramic HEPA Filter Program

    SciTech Connect

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  1. Foam For Filtering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Like nature's honeycomb, foam is a structure of many-sided cells, apparently solid but actually only three percent material and 97 percent air. Foam is made by a heat-producing chemical reaction which expands a plastic material in a manner somewhat akin to the heat-induced rising of a loaf of bread. The resulting structure of interconnected cells is flexible yet strong and extremely versatile in applicati6n. Foam can, for example, be a sound absorber in one form, while in another it allows sound to pass through it. It can be a very soft powder puff material and at the same time a highly abrasive scrubber. A sampling of foam uses includes stereo speaker grilles, applying postage meter ink, filtering lawnmower carburetor air; deadening noise in trucks and tractors, applying cosmetics, releasing fabric softener and antistatic agents in home clothes dryers, painting, filtering factory heating and ventilating systems, shining shoes, polishing cars, sponge-mopping floors, acting as pre-operative surgical scrubbers-the list is virtually limitless. The process by which foam is made produces "windows," thin plastic membranes connecting the cell walls. Windowed foam is used in many applications but for certain others-filtering, for example-it is desirable to have a completely open network. Scott Paper Company's Foam Division, Chester, Pennsylvania, improved a patented method of "removing the windows," to create an open structure that affords special utility in filtering applications. NASA technology contributed to Scott's improvement.

  2. Ozone decomposing filter

    DOEpatents

    Simandl, Ronald F.; Brown, John D.; Whinnery, Jr., LeRoy L.

    1999-01-01

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  3. High temperature filter materials

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Bachovchin, D.M.; Tressler, R.E.

    1992-12-01

    Objectives of this program are to identify the potential long-term thermal/chemical effects that advanced coal-based power generating system environments have on the stability of porous ceramic filter materials, as well as to assess the influence of these effects on filter operating performance and life. We have principally focused our efforts on developing an understanding of the stability of the alumina/mullite filter material at high temperature (i.e., 870, 980, and 1100{degrees}C) under oxidizing conditions which contain gas phase alkali species. Testing has typically been performed in two continuous flow-through, high temperature test facilities at the Westinghouse Science and Technology Center, using 7 cm diameter {times} 6.4 mm thick discs. (Alvin, 1992) Each disc of ceramic filter material is exposed for periods of 100 to 3,000 hours in duration. Additional efforts have been performed at Westinghouse to broaden our understanding of the stability of cordierite, cordierite-silicon nitride, reaction and sintered silicon nitride, and clay bonded silicon carbide under similar simulated advanced coal fired process conditions. The results of these efforts are presented in this paper.

  4. High temperature filter materials

    SciTech Connect

    Alvin, M.A.; Lippert, T.E.; Bachovchin, D.M. . Science and Technology Center); Tressler, R.E. )

    1992-01-01

    Objectives of this program are to identify the potential long-term thermal/chemical effects that advanced coal-based power generating system environments have on the stability of porous ceramic filter materials, as well as to assess the influence of these effects on filter operating performance and life. We have principally focused our efforts on developing an understanding of the stability of the alumina/mullite filter material at high temperature (i.e., 870, 980, and 1100[degrees]C) under oxidizing conditions which contain gas phase alkali species. Testing has typically been performed in two continuous flow-through, high temperature test facilities at the Westinghouse Science and Technology Center, using 7 cm diameter [times] 6.4 mm thick discs. (Alvin, 1992) Each disc of ceramic filter material is exposed for periods of 100 to 3,000 hours in duration. Additional efforts have been performed at Westinghouse to broaden our understanding of the stability of cordierite, cordierite-silicon nitride, reaction and sintered silicon nitride, and clay bonded silicon carbide under similar simulated advanced coal fired process conditions. The results of these efforts are presented in this paper.

  5. Rotating drum filter

    DOEpatents

    Anson, Donald

    1990-01-01

    A perforated drum (10) rotates in a coaxial cylindrical housing (18) having three circumferential ports (19,22,23), and an axial outlet (24) at one end. The axis (11) is horizontal. A fibrous filter medium (20) is fed through a port (19) on or near the top of the housing (81) by a distributing mechanism (36) which lays a uniform mat (26) of the desired thickness onto the rotating drum (10). This mat (26) is carried by the drum (10) to a second port (23) through which dirty fluid (13) enters. The fluid (13) passes through the filter (26) and the cleaned stream (16) exits through the open end (15) of the drum (10) and the axial port (24) in the housing (18). The dirty filter material (20) is carried on to a third port (22) near the bottom of the housing (18) and drops into a receiver (31) from which it is continuously removed, cleaned (30), and returned (32) to the charging port (36) at the top. To support the filter mat, the perforated cylinder may carry a series of tines (40), shaped blades (41), or pockets, so that the mat (26) will not fall from the drum (10) prematurely. To minimize risk of mat failure, the fluid inlet port (23) may be located above the horizontal centerline (11).

  6. Domain wall filters

    SciTech Connect

    Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-03-15

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  7. Ozone decomposing filter

    SciTech Connect

    Simandl, R.F.; Brown, J.D.; Whinnery, L.L. Jr.

    1999-11-02

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  8. DEMONSTRATION BULLETIN: COLLOID POLISHING FILTER METHOD - FILTER FLOW TECHNOLOGY, INC.

    EPA Science Inventory

    The Filter Flow Technology, Inc. (FFT) Colloid Polishing Filter Method (CPFM) was tested as a transportable, trailer mounted, system that uses sorption and chemical complexing phenomena to remove heavy metals and nontritium radionuclides from water. Contaminated waters can be pro...

  9. Optically bistable interference filter

    NASA Astrophysics Data System (ADS)

    Feng, Weiting

    1990-07-01

    In general the temperature dependence of refractive index of coating materials is usually small. The most notable exception being the lead telluride. Thinfilm filters made of PbTe possess anomalously high nortlinearily in refractive index. We have investigated the phenomenon theoretically and experimexitally. 2 . BISTABLE CHARACTERISTICS OF INTERFERENCE FILTERS It can be proved that the transmittance and reflectance of a twin-cavity NLIF which consists of two F-B filters coupled by a single low-index are given by 2 a(1r1 )(1-r0) T --i. -. (1) -d (1r01) (1r12) (1-i-Fsin 4)(1+sin p) where a r01 F . Te phase change of the cavity 0 IS 2r0dnAI0D (2) 2k5dT 1k where the absorbtance A 00 the initial detunning of fresonance and the first term on the right side of the equation(1)-(2) the output characteristics of the NLIF can be calculated. 3 . EXPERIMENTAL CASE The interference filters suggested to be used in my research will be made by vacuum deposition with a thermal source. The filters will be made according to the prescripti The dominant mechanism responsible for d(nhl) must be the change in the refractive index. A low limit on the OB switch-on time is found to be O. 35us and switch-off time is 5. 5us. 4. REFERENCES 1. W. T. Feng " Temperature effects on properties of zinc selenide and lead telluride" to be published in Infrared Physics. 2. H. S. Carslaw Conduction

  10. The multisensor PHD filter: II. Erroneous solution via Poisson magic

    NASA Astrophysics Data System (ADS)

    Mahler, Ronald

    2009-05-01

    The theoretical foundation for the probability hypothesis density (PHD) filter is the FISST multitarget differential and integral calculus. The "core" PHD filter presumes a single sensor. Theoretically rigorous formulas for the multisensor PHD filter can be derived using the FISST calculus, but are computationally intractable. A less theoretically desirable solution-the iterated-corrector approximation-must be used instead. Recently, it has been argued that an "elementary" methodology, the "Poisson-intensity approach," renders FISST obsolete. It has further been claimed that the iterated-corrector approximation is suspect, and in its place an allegedly superior "general multisensor intensity filter" has been proposed. In this and a companion paper I demonstrate that it is these claims which are erroneous. The companion paper introduces formulas for the actual "general multisensor intensity filter." In this paper I demonstrate that (1) the "general multisensor intensity filter" fails in important special cases; (2) it will perform badly in even the easiest multitarget tracking problems; and (3) these rather serious missteps suggest that the "Poisson-intensity approach" is inherently faulty.

  11. Generalized Selection Weighted Vector Filters

    NASA Astrophysics Data System (ADS)

    Lukac, Rastislav; Plataniotis, Konstantinos N.; Smolka, Bogdan; Venetsanopoulos, Anastasios N.

    2004-12-01

    This paper introduces a class of nonlinear multichannel filters capable of removing impulsive noise in color images. The here-proposed generalized selection weighted vector filter class constitutes a powerful filtering framework for multichannel signal processing. Previously defined multichannel filters such as vector median filter, basic vector directional filter, directional-distance filter, weighted vector median filters, and weighted vector directional filters are treated from a global viewpoint using the proposed framework. Robust order-statistic concepts and increased degree of freedom in filter design make the proposed method attractive for a variety of applications. Introduced multichannel sigmoidal adaptation of the filter parameters and its modifications allow to accommodate the filter parameters to varying signal and noise statistics. Simulation studies reported in this paper indicate that the proposed filter class is computationally attractive, yields excellent performance, and is able to preserve fine details and color information while efficiently suppressing impulsive noise. This paper is an extended version of the paper by Lukac et al. presented at the 2003 IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing (NSIP '03) in Grado, Italy.

  12. OPTIMIZATION OF ADVANCED FILTER SYSTEMS

    SciTech Connect

    R.A. Newby; M.A. Alvin; G.J. Bruck; T.E. Lippert; E.E. Smeltzer; M.E. Stampahar

    2002-06-30

    Two advanced, hot gas, barrier filter system concepts have been proposed by the Siemens Westinghouse Power Corporation to improve the reliability and availability of barrier filter systems in applications such as PFBC and IGCC power generation. The two hot gas, barrier filter system concepts, the inverted candle filter system and the sheet filter system, were the focus of bench-scale testing, data evaluations, and commercial cost evaluations to assess their feasibility as viable barrier filter systems. The program results show that the inverted candle filter system has high potential to be a highly reliable, commercially successful, hot gas, barrier filter system. Some types of thin-walled, standard candle filter elements can be used directly as inverted candle filter elements, and the development of a new type of filter element is not a requirement of this technology. Six types of inverted candle filter elements were procured and assessed in the program in cold flow and high-temperature test campaigns. The thin-walled McDermott 610 CFCC inverted candle filter elements, and the thin-walled Pall iron aluminide inverted candle filter elements are the best candidates for demonstration of the technology. Although the capital cost of the inverted candle filter system is estimated to range from about 0 to 15% greater than the capital cost of the standard candle filter system, the operating cost and life-cycle cost of the inverted candle filter system is expected to be superior to that of the standard candle filter system. Improved hot gas, barrier filter system availability will result in improved overall power plant economics. The inverted candle filter system is recommended for continued development through larger-scale testing in a coal-fueled test facility, and inverted candle containment equipment has been fabricated and shipped to a gasifier development site for potential future testing. Two types of sheet filter elements were procured and assessed in the program

  13. Failed supernovae explain the compact remnant mass function

    SciTech Connect

    Kochanek, C. S.

    2014-04-10

    One explanation for the absence of higher mass red supergiants (16.5 M {sub ☉} ≲ M ≲ 25 M {sub ☉}) as the progenitors of Type IIP supernovae (SNe) is that they die in failed SNe creating black holes. Simulations show that such failed SNe still eject their hydrogen envelopes in a weak transient, leaving a black hole with the mass of the star's helium core (5-8 M {sub ☉}). Here we show that this naturally explains the typical masses of observed black holes and the gap between neutron star and black hole masses without any fine-tuning of stellar mass loss, binary mass transfer, or the SN mechanism, beyond having it fail in a mass range where many progenitor models have density structures that make the explosions more likely to fail. There is no difficulty including this ∼20% population of failed SNe in any accounting of SN types over the progenitor mass function. And, other than patience, there is no observational barrier to either detecting these black hole formation events or limiting their rates to be well below this prediction.

  14. The Magnetic Centrifugal Mass Filter

    SciTech Connect

    Abraham J. Fetterman and Nathaniel J. Fisch

    2011-08-04

    Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages. __________________________________________________

  15. Intracoronary thrombolytic therapy: a treatment option for failed mechanical thrombectomy.

    PubMed

    Gallagher, Sean; Jain, Ajay K; Archbold, R Andrew

    2012-11-01

    The benefit of the routine application of aspiration thrombectomy in primary percutaneous coronary intervention (PPCI) is now well established. The optimal management of patients who have "failed" thrombectomy characterized by a large residual thrombus burden after repeated mechanical thrombectomy, however, is not known. We report a case of failed aspiration thrombectomy in a 66-year-old woman who was admitted to our institution with chest pain associated with inferior ST segment elevation. Coronary angiography showed a thrombotic occlusion of the right coronary artery. Aspiration thrombectomy did little to reduce thrombus load and so the patient was treated with intracoronary tenecteplase. Repeat coronary angiography 18 hr later revealed marked thrombus resolution with thrombolysis in myocardial infarction (TIMI) grade 3 anterograde flow and patency of the infarct-related artery was maintained at 2-month follow up. This case demonstrates the potential for intracoronary thrombolytic therapy as a treatment option for the management of patients following failed thrombectomy in PPCI.

  16. Computer simulation of the mechanically-assisted failing canine circulation.

    PubMed

    Barnea, O; Moore, T W; Jaron, D

    1990-01-01

    A model of the cardiovascular system is presented. The model includes representations of the left and right ventricles, a nonlinear multielement model of the aorta and its main branches, and lumped models of the systemic veins and the pulmonary circulation. A simulation of the intra-aortic balloon pump and representations of physiological compensatory mechanisms are also incorporated in the model. Parameters of the left ventricular model were set to simulate either the normal or failing canine circulation. Pressure and flow waveforms throughout the circulation as well as ventricular pressure and volume were calculated for the normal, failing, and assisted failing circulation. Cardiac oxygen supply and consumption were calculated from the model. They were used as direct indices of cardiac energy supply and utilization to assess the effects of cardiac assistance.

  17. Drilling fluid filter

    DOEpatents

    Hall, David R.; Fox, Joe; Garner, Kory

    2007-01-23

    A drilling fluid filter for placement within a bore wall of a tubular drill string component comprises a perforated receptacle with an open end and a closed end. A hanger for engagement with the bore wall is mounted at the open end of the perforated receptacle. A mandrel is adjacent and attached to the open end of the perforated receptacle. A linkage connects the mandrel to the hanger. The linkage may be selected from the group consisting of struts, articulated struts and cams. The mandrel operates on the hanger through the linkage to engage and disengage the drilling fluid filter from the tubular drill string component. The mandrel may have a stationary portion comprising a first attachment to the open end of the perforated receptacle and a telescoping adjustable portion comprising a second attachment to the linkage. The mandrel may also comprise a top-hole interface for top-hole equipment.

  18. Filtered cathodic arc source

    DOEpatents

    Falabella, S.; Sanders, D.M.

    1994-01-18

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.

  19. Filtered cathodic arc source

    DOEpatents

    Falabella, Steven; Sanders, David M.

    1994-01-01

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45.degree. to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

  20. Assessment of ceramic membrane filters

    SciTech Connect

    Ahluwalia, R.K.; Geyer, H.K.; Im, K.H.

    1995-08-01

    The objectives of this project include the development of analytical models for evaluating the fluid mechanics of membrane coated, dead-end ceramic filters, and to determine the effects of thermal and thermo-chemical aging on the material properties of emerging ceramic hot gas filters. A honeycomb cordierite monolith with a thin ceramic coating and a rigid candle filter were evaluated.

  1. High frequency integrated MOS filters

    NASA Technical Reports Server (NTRS)

    Peterson, C.

    1990-01-01

    Several techniques exist for implementing integrated MOS filters. These techniques fit into the general categories of sampled and tuned continuous-time filters. Advantages and limitations of each approach are discussed. This paper focuses primarily on the high frequency capabilities of MOS integrated filters.

  2. Drive Diagnostic Filter Wheel Control

    SciTech Connect

    Uhlich, D.

    2007-07-17

    DrD Filter Wheel Control is National Instrument's Labview software that drives a Drive Diagnostic filter wheel. The software can drive the filter wheel between each end limit, detect the positive and negative limit and each home position and post the stepper motot values to an Excel spreadsheet. The software can also be used to cycle the assembly between the end limits.

  3. Fixed memory least squares filtering

    NASA Technical Reports Server (NTRS)

    Bierman, G. J.

    1975-01-01

    Buxbaum has reported on three algorithms for computing least squares estimates that are based on fixed amounts of data. In this correspondence, the filter is arranged as a point-deleting Kalman filter concatenated with the standard point-inclusion Kalman filter. The resulting algorithm is couched in a square root framework for greater numerical stability, and special attention is given to computer implementation.

  4. Quick-change filter cartridge

    DOEpatents

    Rodgers, John C.; McFarland, Andrew R.; Ortiz, Carlos A.

    1995-01-01

    A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

  5. Regenerable particulate filter

    DOEpatents

    Stuecker, John N.; Cesarano, III, Joseph; Miller, James E.

    2009-05-05

    A method of making a three-dimensional lattice structure, such as a filter used to remove particulates from a gas stream, where the physical lattice structure is designed utilizing software simulation from pre-defined mass transfer and flow characteristics and the designed lattice structure is fabricated using a free-form fabrication manufacturing technique, where the periodic lattice structure is comprised of individual geometric elements.

  6. Failed MTR Fuel Element Detect in a Sipping Tests

    SciTech Connect

    Zeituni, C.A.; Terremoto, L.A.A.; da Silva, J.E.R.

    2004-10-06

    This work describes sipping tests performed on Material Testing Reactor (MTR) fuel elements of the IEA-R1 research reactor, in order to find out which one failed in the core during a routine operation. Radioactive iodine isotopes {sup 131}I and {sup 133}I, employed as failure monitors, were detected in samples corresponding to the failed fuel element. The specific activity of each sample, as well as the average leaking rate, were measured for {sup 137}Cs. The nuclear fuels U{sub 3}O{sub 8} - Al dispersion and U - Al alloy were compared concerning their measured average leaking rates of {sup 137}Cs.

  7. Soldier imprisoned for failing to disclose HIV to sex partners.

    PubMed

    1999-02-01

    Pfc. [Name removed], a soldier at Aberdeen Proving Ground in Maryland, was sentenced to 3 years in a military prison for failing to disclose her HIV-positive status to her sexual partners. [Name removed]' commander had ordered her to use condoms and inform her sexual partners of her HIV status. She failed to inform eight of the nine men with whom she had sex and, she did not use a condom with four of them. So far, all nine men have tested negative for HIV. [Name removed] will be reduced to the rank of private, receive a bad conduct discharge, and forfeit all pay and benefits.

  8. Carbon nanotube filters

    NASA Astrophysics Data System (ADS)

    Srivastava, A.; Srivastava, O. N.; Talapatra, S.; Vajtai, R.; Ajayan, P. M.

    2004-09-01

    Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus (~25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.

  9. Optical filtering of aeromagnetic maps.

    PubMed

    Arsenault, H H; Séguin, M K; Brousseau, N

    1974-05-01

    An optical processor has been used to filter aeromagnetic contour maps in order to obtain information on underground magnetic ore deposits. This was accomplished by directional filtering of the spatial Fourier transform of the contour map. The directional filtering yields maps of gradients having given directions. A digital analysis was also performed on the data so that the feasibility of the optical technique could be evaluated. The results obtained so far suggest that a systematic filtering of aeromagnetic maps can be carried out at low cost and that the filtered maps can yield useful information to the interpreter.

  10. Modular filter design for the white-beam undulator/wiggler beamlines at the Advanced Photon Source

    SciTech Connect

    Brite, C.; Shu, D.; Nian, T.; Wang, Z.; Haeffner, D.; Alp, E.; Kuzay, T.

    1994-09-01

    A new filter has been designed at Argonne National Laboratory that is intended for the use in undulator/wiggler beamlines at the Advanced Photon Source. The water-cooled frame allows up to four individual filter foil banks simultaneously in the beam path. Additionally, the bottom of each frame holds two thin (20 {mu}m) uncooled carbon filters in tandem for low-energy filtering. Therefore, a maximum of 625 filter selection combinations is theoretically possible. The design is intelligent, compact and modular, with great flexibility for the users. To prevent accidental movement of the filter, effort has been taken to provide a mechanically locked, fail-safe actuator system. Programming aspects are under development as part of our general personnel and equipment protection system. Aspects of the design and operational principles of the filter are presented in this paper.

  11. Kaon Filtering For CLAS Data

    SciTech Connect

    McNabb, J.

    2001-01-30

    The analysis of data from CLAS is a multi-step process. After the detectors for a given running period have been calibrated, the data is processed in the so called pass-1 cooking. During the pass-1 cooking each event is reconstructed by the program a1c which finds particle tracks and computes momenta from the raw data. The results are then passed on to several data monitoring and filtering utilities. In CLAS software, a filter is a parameterless function which returns an integer indicating whether an event should be kept by that filter or not. There is a main filter program called g1-filter which controls several specific filters and outputs several files, one for each filter. These files may then be analyzed separately, allowing individuals interested in one reaction channel to work from smaller files than using the whole data set would require. There are several constraints on what the filter functions should do. Obviously, the filtered files should be as small as possible, however the filter should also not reject any events that might be used in the later analysis for which the filter was intended.

  12. Advanced hot gas filter development

    SciTech Connect

    McMahon, T.J.

    1998-12-31

    Advanced coal-based power generation systems require hot gas cleanup under high-temperature, high-pressure process conditions in order to realize high efficiency and superior environmental performance. A key component of Integrated Gasification Combined Cycle and Pressurized Fluidized Bed Combustion systems is the hot gas filtration system, which removes particulate matter from the gas stream before it enters the gas turbine. The US DOE is currently sponsoring a program to develop and test hot gas filtration systems, demonstrating their reliability and commercial readiness. Reliability of individual filter elements is a major factor in determining the overall system reliability, and testing has shown that conventional ceramic filter elements are subject to brittle failure and thermal stress damage. In order to increase filter element reliability, a program was initiated to develop ceramic and metal filter elements resistant to brittle failure and thermal stress damage. Filter elements have been developed using advanced materials including continuous fiber ceramic composites, other novel ceramics, and corrosion resistant metals. The general approach taken under this program has been to first develop porous filter media from advanced materials that meet permeability and strength requirements, followed by fabrication of porous media into full scale filter elements. Filter elements and filter media were subjected to laboratory scale corrosion and filtration testing. Filter elements successfully passing laboratory testing have been tested under pilot scale conditions. This paper will summarize the development and testing of these advanced hot gas filters.

  13. Zero Gyro Kalman Filtering in the Presence of a Reaction Wheel Failure

    NASA Technical Reports Server (NTRS)

    Hur-Diaz, Sun; Wirzburger, John; Smith, Dan; Myslinski, Mike

    2007-01-01

    Typical implementation of Kalman filters for spacecraft attitude estimation involves the use of gyros for three-axis rate measurements. When there are less than three axes of information available, the accuracy of the Kalman filter depends highly on the accuracy of the dynamics model. This is particularly significant during the transient period when a reaction wheel with a high momentum fails, is taken off-line, and spins down. This paper looks at how a reaction wheel failure can affect the zero-gyro Kalman filter performance for the Hubble Space Telescope and what steps are taken to minimize its impact.

  14. Zero Gyro Kalman Filtering in the presence of a Reaction Wheel Failure

    NASA Technical Reports Server (NTRS)

    Hur-Diaz, Sun; Wirzburger, John; Smith, Dan; Myslinski, Mike

    2007-01-01

    Typical implementation of Kalman filters for spacecraft attitude estimation involves the use of gyros for three-axis rate measurements. When there are less than three axes of information available, the accuracy of the Kalman filter depends highly on the accuracy of the dynamics model. This is particularly significant during the transient period when a reaction wheel with a high momentum fails, is taken off-line, and spins down. This paper looks at how a reaction wheel failure can affect the zero-gyro Kalman filter performance for the Hubble Space Telescope and what steps are taken to minimize its impact.

  15. In-service filter testing

    SciTech Connect

    Terada, K.; Woodard, R.W.; Jensen, R.T.

    1985-04-29

    This report contains the observations, test results, and conclusions of three separate in-service tests beginning in November 1979 and concluding in September 1983. The in-service tests described in this report produced encouraging results on filters constructed with fiberglass medium containing 5% Nomex and separators of aluminum foil coated with a thin film of vinyl-epoxy polymer. Filters containing medium with Kevlar fiber additives demonstrated they merited further evaluation. Other types of filters tested include separatorless filters (Flanders SuperFlow) and one filter with fiberglass separators. Asbestos-containing filters were used for comparison until their supply was exhausted. All filters tested were judged to have performed satisfactorily under the test conditions.

  16. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND NEW MEXICO Regulations § 983.52 Failed lots/rework procedure. (a) Substandard pistachios. Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements....

  17. 9 CFR 442.5 - Handling of failed product.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Handling of failed product. 442.5 Section 442.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... upon testing in accordance with the methods prescribed in § 442.2 of this subchapter shall be...

  18. 9 CFR 442.5 - Handling of failed product.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Handling of failed product. 442.5 Section 442.5 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... upon testing in accordance with the methods prescribed in § 442.2 of this subchapter shall be...

  19. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Reconditioning failing quality peanuts. 996.50 Section... SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality...

  20. 7 CFR 996.50 - Reconditioning failing quality peanuts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Reconditioning failing quality peanuts. 996.50 Section... SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE MINIMUM QUALITY AND HANDLING STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Quality...

  1. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  2. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  3. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  4. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  5. "Badminton Player-Coach" Interactions between Failing Students

    ERIC Educational Resources Information Center

    Mascret, Nicolas

    2011-01-01

    Background: Physical education teachers often use the player-coach dyad in individual opposition sports so that students can obtain information on their actions and then better regulate them. This type of work also develops methodological and social skills. However, the task of observing a partner often poses problems for failing students, who…

  6. Florida hospital cuts failed pediatric sedation rate 98%.

    PubMed

    2008-07-01

    * In a survey of Broward General Medical Center, The Joint Commission found fault with the administration of sedation for pediatric outpatient diagnostic procedures. * There is a great deal of variation among health care facilities on sedatives use and techniques and safety standards used. * Broward's initiative eliminated rescheduled exams and failed procedures by 98%.

  7. Feeding behaviour in young children who fail to thrive.

    PubMed

    Drewett, Robert F; Kasese-Hara, Mambwe; Wright, Charlotte

    2003-02-01

    One-year-old children who failed to thrive in infancy were identified through a specialist clinical service using a conditional weight gain criterion which identified the slowest gaining 5%. Control children of the same age and sex were recruited from the same local geographical area and had the same primary care physician. The food intake and feeding behaviour of the groups was compared using a detailed observational micro-analysis of a lunchtime meal, using a behavioural coding scheme developed for use over the weaning period. Both food and fluid intake at the test meal were significantly lower in the children who failed to thrive than the controls. There was no significant difference in the energy density of the foods they consumed. As recorded in the behaviour counts at the meal, the mothers of the children who failed to thrive fed them as much as or more than the control mothers fed their children. The children who failed to thrive tended to refuse or reject the offered food more, and also fed themselves significantly less often than the controls. These behavioural differences during the meal accounted for about one third of the difference in energy intake between the groups. PMID:12631505

  8. 77 FR 9846 - Source of Income From Qualified Fails Charges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ..., and 75 FR 81457, respectively. The temporary and proposed regulations provide that the source of... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ78 Source of Income From Qualified Fails Charges AGENCY.... SUMMARY: This document contains final regulations that prescribe the source of income received on...

  9. A "Fresh Start" for a "Failing School"? A Qualitative Study

    ERIC Educational Resources Information Center

    Araujo, Marta

    2009-01-01

    This paper examines "Fresh Start," a New Labour flagship initiative to raise education "standards" in a radical and innovative way. Drawing on a qualitative study of a comprehensive school in England, I argue that the initiative added to the problems faced by the "failing school" and promoted rather traditional ways of raising "standards" due to…

  10. Civil Liability for Failing to Report Child Abuse.

    ERIC Educational Resources Information Center

    Lehto, Neil J.

    1977-01-01

    The article examines the Landeros decision (which ruled that a doctor who fails to report a child abuse victim can be held liable for subsequent injuries inflicted on the child) and discusses three theories of proving civil liability for the failure to report child abuse victims. Addressed are the following topics: the problem of child abuse and…

  11. Understanding and Working with "Failed Communication" in Telecollaborative Exchanges

    ERIC Educational Resources Information Center

    O'Dowd, Robert; Ritter, Markus

    2006-01-01

    It is by now well established that telecollaborative exchanges frequently end in "failed communication" and do not automatically bring about successful negotiation of meaning between the learners. Instead, the intended pedagogic and linguistic aims of online interaction are repeatedly missed, and projects may end in low levels of participation,…

  12. Depressed phosphatidic acid-induced contractile activity of failing cardiomyocytes.

    PubMed

    Tappia, Paramjit S; Maddaford, Thane G; Hurtado, Cecilia; Panagia, Vincenzo; Pierce, Grant N

    2003-01-10

    The effects of phosphatidic acid (PA), a known inotropic agent, on Ca(2+) transients and contractile activity of cardiomyocytes in congestive heart failure (CHF) due to myocardial infarction were examined. In control cells, PA induced a significant increase (25%) in active cell shortening and Ca(2+) transients. The phospholipase C (PLC) inhibitor, 2-nitro-4-carboxyphenyl N,N-diphenylcarbonate, blocked the positive inotropic action induced by PA, indicating that PA induces an increase in contractile activity and Ca(2+) transients through stimulation of PLC. Conversely, in failing cardiomyocytes there was a loss of PA-induced increase in active cell shortening and Ca(2+) transients. PA did not alter resting cell length. Both diastolic and systolic [Ca(2+)] were significantly elevated in the failing cardiomyocytes. In vitro assessment of the cardiac sarcolemmal (SL) PLC activity revealed that the impaired failing cardiomyocyte response to PA was associated with a diminished stimulation of SL PLC activity by PA. Our results identify an important defect in the PA-PLC signaling pathway in failing cardiomyocytes, which may have significant implications for the depressed contractile function during CHF.

  13. What is the optimal rate of failed extubation?

    PubMed Central

    2012-01-01

    Failed extubation (FE), defined as reintubation 48 or 72 hours after planned extubation, occurs in a significant percentage of patients and is associated with a substantial burden of morbidity and mortality. This commentary reviews the literature describing FE rates and the clinical consequences of FE and proposes an 'optimal' rate of FE as well as avenues for future research. PMID:22356725

  14. Ballooning osteolysis in 71 failed total ankle arthroplasties.

    PubMed

    Singh, Gurpal; Reichard, Theresa; Hameister, Rita; Awiszus, Friedemann; Schenk, Katja; Feuerstein, Bernd; Roessner, Albert; Lohmann, Christoph

    2016-08-01

    Background and purpose - Aseptic loosening is a major cause of failure in total ankle arthroplasty (TAA). In contrast to other total joint replacements, large periarticular cysts (ballooning osteolysis) have frequently been observed in this context. We investigated periprosthetic tissue responses in failed TAA, and performed an element analysis of retrieved tissues in failed TAA. Patients and methods - The study cohort consisted of 71 patients undergoing revision surgery for failed TAA, all with hydroxyapatite-coated implants. In addition, 5 patients undergoing primary TAA served as a control group. Radiologically, patients were classified into those with ballooning osteolysis and those without, according to defined criteria. Histomorphometric, immunohistochemical, and elemental analysis of tissues was performed. Von Kossa staining and digital microscopy was performed on all tissue samples. Results - Patients without ballooning osteolysis showed a generally higher expression of lymphocytes, and CD3+, CD11c+, CD20+, and CD68+ cells in a perivascular distribution, compared to diffuse expression. The odds of having ballooning osteolysis was 300 times higher in patients with calcium content >0.5 mg/g in periprosthetic tissue than in patients with calcium content ≤0.5 mg/g (p < 0.001). Interpretation - There have been very few studies investigating the pathomechanisms of failed TAA and the cause-effect nature of ballooning osteolysis in this context. Our data suggest that the hydroxyapatite coating of the implant may be a contributory factor.

  15. Improving Charter School Accountability: The Challenge of Closing Failing Schools

    ERIC Educational Resources Information Center

    Osborne, David

    2012-01-01

    Today some 5,600 charter schools are in operation, with more than two million students. Some critics persist in a fruitless argument that these schools have failed, despite a mountain of evidence to the contrary. But regardless of your opinion about them, charter schools are here to stay. Those concerned about public education should quit debating…

  16. Evidence of a "Failing Newspaper" under the Newspaper Preservation Act.

    ERIC Educational Resources Information Center

    Picard, Robert G.

    The Newspaper Preservation Act of 1970 makes it possible for competing newspapers to combine advertising, production, circulation and management functions into a single newspaper corporation. For the attorney general and the courts to authorize a joint operating agreement (JOA) for a "failing newspaper," certain conditions must be met and certain…

  17. Failing Boys! Beyond Crisis, Moral Panic and Limiting Stereotypes

    ERIC Educational Resources Information Center

    Martino, Wayne

    2011-01-01

    For some time now, school boards, Ministries of Education, and the popular media have been expressing concerns about failing boys and how best to meet their needs, framing these concerns in terms of a crisis in which boys are the "new disadvantaged". This perspective does not provide an accurate representation of the problem and, in fact, detracts…

  18. Hip arthroplasty for failed treatment of proximal femoral fractures.

    PubMed

    D'Arrigo, Carmelo; Perugia, Dario; Carcangiu, Alessandro; Monaco, Edoardo; Speranza, Attilio; Ferretti, Andrea

    2010-10-01

    Failed treatment of an intertrochanteric fracture typically leads to profound functional disability and pain. Salvage treatment with hip arthroplasty may be considered. The aim of this study was to evaluate the results and complications of hip arthroplasty performed as a salvage procedure after the failed treatment of an intertrochanteric hip fracture. Twenty-one patients were treated in our hospital with hip arthroplasty for failed treatment of intertrochanteric hip fracture. There were sixteen women and five men with a mean age of 75.8 years (range 61-85 years). Fourteen patients had failure of a previous nail fixation procedure, five had failure of a plate fixation, one of hip screws fixation and one of Ender nail fixation. In 19 out of 21 patients we performed a total hip arthroplasty-14 cases used modular implants with long-stems and five cases used a standard straight stem. In 2 of 21 cases we used a bipolar hemiarthroplasty. A statistically significant improvement was found comparing pre and postoperative conditions (p < 0.05). Our experience confirms that total hip arthroplasty is a satisfactory salvage procedure after failed treatment of an intertrochanteric fracture in elderly patients with few serious orthopaedic complications and acceptable clinical outcomes. PMID:19572131

  19. A comparative study of a modified filtering trabeculotomy and conventional trabeculectomy

    PubMed Central

    Matlach, Juliane; Hipp, Matthias; Wagner, Martin; Heuschmann, Peter U; Klink, Thomas; Grehn, Franz

    2015-01-01

    Purpose The objective of the study reported here was to evaluate the outcome of a modified filtering trabeculotomy (FTO) without iridectomy in open-angle glaucoma compared with that of conventional trabeculectomy (trab). Patients and methods Thirty eyes of 30 patients who underwent modified FTO were prospectively followed for 1 year and were compared with 87 conventional trab patients (87 eyes), matched for age and preoperative intraocular pressure (IOP). The FTO procedure consisted of a deep sclerectomy and trabeculotomy preserving the trabeculo-Descemet membrane, without iridectomy. Main outcome measures were complete success (IOP <18 mmHg and >/=30% IOP reduction, without medication), IOP, visual acuity, medication, complications, and subsequent surgeries. Results In the conventional trab group, the median preoperative IOP was 23.0 mmHg (interquartile range 20.0–27.0) with 3.0 (2.0–3.0) medications, compared with 23.0 mmHg (20.0–27.0) and 3.0 (2.8–4.0) in the modified FTO group. Median postoperative IOP at 12 months was 12.0 mmHg (10.0–13.0) in the conventional trab and 11.0 mmHg (8.0–14.0) in the modified FTO group (P=0.3). The complete success rate at 1 year was 83.1% and 79.3% in the conventional trab group and modified FTO group, respectively (P=0.8). The complications hypotony (20.7%, 24.1%), choroidal detachment (2.3%, 10.3%), and bleb scarring (17.2%, 13.8%), were present in the conventional trab group and modified FTO group, respectively. Conclusion The outcomes of reduced IOP and medications in the FTO group were not different to those in the conventional trab group over 1 year, but some complications were more often seen with the modified FTO technique. The new filtration trabeculotomy, however, has the advantage of avoiding iridectomy, thus reducing the risk of cataract formation, and may result in the development of more favorable blebs by controlling the flow over two resistance levels. PMID:25792801

  20. Wiener filter for filtered back projection in digital breast tomosynthesis

    NASA Astrophysics Data System (ADS)

    Wang, Xinying; Mainprize, James G.; Wu, Gang; Yaffe, Martin J.

    2012-03-01

    Conventional filtered back projection (FBP) reconstruction for digital breast tomosynthesis (DBT) can suffer from a low signal to noise ratio. Because of the strong amplification by the reconstruction filters (ramp, apodization and slice thickness), noise at high spatial frequencies can be greatly increased. Image enhancement by Wiener filtering is investigated as a possible method to improve image quality. A neighborhood wavelet coefficient window technique is used to estimate the noise content of projection images and a Wiener filter is applied to the projection images. The neighborhood wavelet coefficient window is a non-linear technique, which may cause the Wiener filters estimated before and after the application of the reconstruction filters to be different. Image quality of a FBP reconstruction with and without Wiener filtering is investigated using a Fourier-based observer detectability metric ( d' ) for evaluation. Simulations of tomosynthesis are performed in both homogeneous and anatomic textured backgrounds containing lowcontrast masses or small microcalcifications. Initial results suggest that improvements in detectability can be achieved when the Wiener filter is applied, especially when the Wiener filter is estimated for the reconstruction filtered projections.

  1. OPTIMIZATION OF ADVANCED FILTER SYSTEMS

    SciTech Connect

    R.A. Newby; G.J. Bruck; M.A. Alvin; T.E. Lippert

    1998-04-30

    Reliable, maintainable and cost effective hot gas particulate filter technology is critical to the successful commercialization of advanced, coal-fired power generation technologies, such as IGCC and PFBC. In pilot plant testing, the operating reliability of hot gas particulate filters have been periodically compromised by process issues, such as process upsets and difficult ash cake behavior (ash bridging and sintering), and by design issues, such as cantilevered filter elements damaged by ash bridging, or excessively close packing of filtering surfaces resulting in unacceptable pressure drop or filtering surface plugging. This test experience has focused the issues and has helped to define advanced hot gas filter design concepts that offer higher reliability. Westinghouse has identified two advanced ceramic barrier filter concepts that are configured to minimize the possibility of ash bridge formation and to be robust against ash bridges should they occur. The ''inverted candle filter system'' uses arrays of thin-walled, ceramic candle-type filter elements with inside-surface filtering, and contains the filter elements in metal enclosures for complete separation from ash bridges. The ''sheet filter system'' uses ceramic, flat plate filter elements supported from vertical pipe-header arrays that provide geometry that avoids the buildup of ash bridges and allows free fall of the back-pulse released filter cake. The Optimization of Advanced Filter Systems program is being conducted to evaluate these two advanced designs and to ultimately demonstrate one of the concepts in pilot scale. In the Base Contract program, the subject of this report, Westinghouse has developed conceptual designs of the two advanced ceramic barrier filter systems to assess their performance, availability and cost potential, and to identify technical issues that may hinder the commercialization of the technologies. A plan for the Option I, bench-scale test program has also been developed based

  2. Multilevel ensemble Kalman filtering

    DOE PAGES

    Hoel, Hakon; Law, Kody J. H.; Tempone, Raul

    2016-06-14

    This study embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo step of the ensemble Kalman filter (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. Finally, the resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.

  3. Robust Kriged Kalman Filtering

    SciTech Connect

    Baingana, Brian; Dall'Anese, Emiliano; Mateos, Gonzalo; Giannakis, Georgios B.

    2015-11-11

    Although the kriged Kalman filter (KKF) has well-documented merits for prediction of spatial-temporal processes, its performance degrades in the presence of outliers due to anomalous events, or measurement equipment failures. This paper proposes a robust KKF model that explicitly accounts for presence of measurement outliers. Exploiting outlier sparsity, a novel l1-regularized estimator that jointly predicts the spatial-temporal process at unmonitored locations, while identifying measurement outliers is put forth. Numerical tests are conducted on a synthetic Internet protocol (IP) network, and real transformer load data. Test results corroborate the effectiveness of the novel estimator in joint spatial prediction and outlier identification.

  4. Advances in Collaborative Filtering

    NASA Astrophysics Data System (ADS)

    Koren, Yehuda; Bell, Robert

    The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

  5. The effect of filter cakes on filter medium resistance

    SciTech Connect

    Chase, G.G.; Arconti, J.; Kanel, J.

    1994-10-01

    The high resistance of a filter medium to fluid flow is a universal problem affecting many industries. The small thickness of the filter media makes local pressure and porosity measurements impractical. Analysis of the continuum equations and boundary conditions provide a basis for defining a relative medium resistance. Experiments are conducted on three particulate materials and on three different high flow rate filter media. The results show that the increase in medium resistance varies up to about four times the resistance of a clean filter medium with no cake present. The results also show that in most cases the relative resistance is dependent upon cake height.

  6. Nanoparticle optical notch filters

    NASA Astrophysics Data System (ADS)

    Kasinadhuni, Pradeep Kumar

    Developing novel light blocking products involves the design of a nanoparticle optical notch filter, working on the principle of localized surface plasmon resonance (LSPR). These light blocking products can be used in many applications. One such application is to naturally reduce migraine headaches and light sensitivity. Melanopsin ganglion cells present in the retina of the human eye, connect to the suprachiasmatic nucleus (SCN-the body's clock) in the brain, where they participate in the entrainment of the circadian rhythms. As the Melanopsin ganglion cells are involved in triggering the migraine headaches in photophobic patients, it is necessary to block the part of visible spectrum that activates these cells. It is observed from the action potential spectrum of the ganglion cells that they absorb light ranging from 450-500nm (blue-green part) of the visible spectrum with a λmax (peak sensitivity) of around 480nm (blue line). Currently prescribed for migraine patients is the FL-41 coating, which blocks a broad range of wavelengths, including wavelengths associated with melanopsin absorption. The nanoparticle optical notch filter is designed to block light only at 480nm, hence offering an effective prescription for the treatment of migraine headaches.

  7. Anisotropic Total Variation Filtering

    SciTech Connect

    Grasmair, Markus; Lenzen, Frank

    2010-12-15

    Total variation regularization and anisotropic filtering have been established as standard methods for image denoising because of their ability to detect and keep prominent edges in the data. Both methods, however, introduce artifacts: In the case of anisotropic filtering, the preservation of edges comes at the cost of the creation of additional structures out of noise; total variation regularization, on the other hand, suffers from the stair-casing effect, which leads to gradual contrast changes in homogeneous objects, especially near curved edges and corners. In order to circumvent these drawbacks, we propose to combine the two regularization techniques. To that end we replace the isotropic TV semi-norm by an anisotropic term that mirrors the directional structure of either the noisy original data or the smoothed image. We provide a detailed existence theory for our regularization method by using the concept of relaxation. The numerical examples concluding the paper show that the proposed introduction of an anisotropy to TV regularization indeed leads to improved denoising: the stair-casing effect is reduced while at the same time the creation of artifacts is suppressed.

  8. Robust fault detection filter design

    NASA Astrophysics Data System (ADS)

    Douglas, Randal Kirk

    The detection filter is a specially tuned linear observer that forms the residual generation part of an analytical redundancy system designed for model-based fault detection and identification. The detection filter has an invariant state subspace structure that produces a residual with known and fixed directional characteristics in response to a known design fault direction. In addition to a parameterization of the detection filter gain, three methods are given for improving performance in the presence of system disturbances, sensor noise, model mismatch and sensitivity to small parameter variations. First, it is shown that by solving a modified algebraic Riccati equation, a stabilizing detection filter gain is found that bounds the H-infinity norm of the transfer matrix from system disturbances and sensor noise to the detection filter residual. Second, a specially chosen expanded-order detection filter is formed with fault detection properties identical to a set of independent reduced-order filters that have no structural constraints. This result is important to the practitioner because the difficult problem of finding a detection filter insensitive to disturbances and sensor noise is converted to the easier problem of finding a set of uncoupled noise insensitive filters. Furthermore, the statistical properties of the reduced-order filter residuals are easier to find than the statistical properties of the structurally constrained detection filter residual. Third, an interpretation of the detection filter as a special case of the dual of the restricted decoupling problem leads to a new detection filter eigenstructure assignment algorithm. The new algorithm places detection filter left eigenvectors, which annihilate the detection spaces, rather than right eigenvectors, which span the detection spaces. This allows for a more flexible observer based fault detection system structure that could not be formulated as a detection filter. Furthermore, the link to the dual

  9. Fail-safe transcription termination: Because one is never enough.

    PubMed

    Lemay, Jean-François; Bachand, François

    2015-01-01

    Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of RNAPII from the DNA template. As transcription termination is intimately linked to RNA 3' end processing, termination pathways have a key decisive influence on the fate of the transcribed RNA. Quite remarkably, when reaching the 3' end of genes, a substantial fraction of RNAPII fail to terminate transcription, requiring the contribution of alternative or "fail-safe" mechanisms of termination to release the polymerase. This point of view covers redundant mechanisms of transcription termination and how they relate to conventional termination models. In particular, we expand on recent findings that propose a reverse torpedo model of termination, in which the 3'5' exonucleolytic activity of the RNA exosome targets transcription events associated with paused and backtracked RNAPII. PMID:26273910

  10. Etiology, Diagnosis, and Management of Failed SLAP Repair.

    PubMed

    Werner, Brian C; Brockmeier, Stephen F; Miller, Mark D

    2014-09-01

    In general, favorable outcomes have been achieved with arthroscopic repair of superior labral anterior-posterior (SLAP) tears. However, some patients remain dissatisfied or suffer further injury after SLAP repair and may seek additional treatment to alleviate their symptoms. The cause of persistent pain or recurrent symptoms after repair is likely multifactorial; therefore, careful preoperative workup is required to elucidate the cause of pain. Review of the details of previous surgical procedures is crucial because certain fixation methods are prone to failure or can cause additional injury. Failed SLAP repair can be managed with nonsurgical or surgical options. Nonsurgical modalities include physical therapy and strengthening programs, anti-inflammatory agents, and activity modification. Surgical options include revision SLAP repair and biceps tenotomy or tenodesis with or without revision SLAP repair. Outcomes after surgical management of failed SLAP repair are inferior to those of primary repair. Select patients may be better served by primary biceps tenodesis rather than SLAP repair.

  11. Spatial filters for high average power lasers

    DOEpatents

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  12. Paying for innovation. Failed strategies add to hospitals' reimbursement losses.

    PubMed

    Pallarito, K

    Hospitals across the country are struggling to balance revenue shortfalls and cost increases as the lid on government and private-payer payments closes tighter. They're also grappling with losses on failed physician and HMO investments, the expense of new medical technologies and larger-than-planned costs related to "millennium bug" cures. This is the second part of a two-part series on financial turmoil in healthcare.

  13. Results of Trabectome Surgery Following Failed Glaucoma Tube Shunt Implantation

    PubMed Central

    Mosaed, Sameh; Chak, Garrick; Haider, Asghar; Lin, Ken Y.; Minckler, Don S.

    2015-01-01

    Abstract To evaluate the safety and efficacy of Trabectome after failed tube shunt surgery. Twenty patients with prior failed tube shunt surgery who underwent Trabectome alone were included. All patients had at least 3 months of follow-up. Outcomes measured included intraocular pressure (IOP), glaucoma medications, and secondary glaucoma surgeries. The success for Kaplan–Meier survival analysis is defined as IOP ≤21 mm Hg, IOP reduced by at least 20% from preoperative IOP, and no secondary glaucoma surgery. Mean preoperative IOP was 23.7 ± 6.4 mm Hg and mean number of glaucoma medications was 3.2 ± 1.5. At 12 months, IOP was reduced to 15.5 ± 3.2 mm Hg (P = 0.05) and number of medications was reduced to 2.4 ± 1.5 (P = 0.44). Survival rate at 12 months was 84% and 3 patients required additional glaucoma surgery with 15 patients reaching 12 months follow-up. Other than failure of IOP control and transient hypotony (IOP < 3 mm Hg) day 1 in 2 cases, there were no adverse events. Trabecular bypass procedures have traditionally been considered an approach appropriate for early-to-moderate glaucoma; however, our study indicates benefit in refractory glaucoma as well. Eyes that are prone to conjunctival scarring and hypertrophic wound healing, such as those who have failed tube shunt surgery, may benefit from procedures that avoid conjunctival incision such as Trabectome. This study indicates potential benefits in this patient population. Trabectome was safe and effective in reducing IOP at 1-year follow-up in patients with prior failed tube shunt surgery, but not effective in reducing medication reliance in these patients. PMID:26222842

  14. Fail-safe designs for large capacity battery systems

    DOEpatents

    Kim, Gi-Heon; Smith, Kandler; Ireland, John; Pesaran, Ahmad A.; Neubauer, Jeremy

    2016-05-17

    Fail-safe systems and design methodologies for large capacity battery systems are disclosed. The disclosed systems and methodologies serve to locate a faulty cell in a large capacity battery, such as a cell having an internal short circuit, determine whether the fault is evolving, and electrically isolate the faulty cell from the rest of the battery, preventing further electrical energy from feeding into the fault.

  15. Coated x-ray filters

    DOEpatents

    Steinmeyer, P.A.

    1992-11-24

    A radiation filter for filtering radiation beams of wavelengths within a preselected range of wavelengths comprises a radiation transmissive substrate and an attenuating layer deposited on the substrate. The attenuating layer may be deposited by a sputtering process or a vacuum process. Beryllium may be used as the radiation transmissive substrate. In addition, a second radiation filter comprises an attenuating layer interposed between a pair of radiation transmissive layers. 4 figs.

  16. Coated x-ray filters

    DOEpatents

    Steinmeyer, Peter A.

    1992-11-24

    A radiation filter for filtering radiation beams of wavelengths within a preselected range of wavelengths comprises a radiation transmissive substrate and an attenuating layer deposited on the substrate. The attenuating layer may be deposited by a sputtering process or a vacuum process. Beryllium may be used as the radiation transmissive substrate. In addition, a second radiation filter comprises an attenuating layer interposed between a pair of radiation transmissive layers.

  17. In Situ Cleanable HEPA Filter

    SciTech Connect

    Phillips, T.D.

    1999-11-18

    This paper describes a welded steel HEPA filter which uses liquid spray cleaning and vacuum drying. Development of the filter was initiated in order to eliminate personnel exposure, disposal cost, and short lifetime associated with systems commonly employed throughout the Department of Energy complex. In addition the design promises to resolve the issues of fire, elevated temperatures, wetting, filter strength, air leaks and aging documented in the May, 1999 DNFSB-TECH-23 report.

  18. Note: Cryogenic coaxial microwave filters

    SciTech Connect

    Tancredi, G.; Meeson, P. J.; Schmidlin, S.

    2014-02-15

    The careful filtering of microwave electromagnetic radiation is critical for controlling the electromagnetic environment for experiments in solid-state quantum information processing and quantum metrology at millikelvin temperatures. We describe the design and fabrication of a coaxial filter assembly and demonstrate that its performance is in excellent agreement with theoretical modelling. We further perform an indicative test of the operation of the filters by making current-voltage measurements of small, underdamped Josephson junctions at 15 mK.

  19. Multi-filter spectrophotometry simulations

    NASA Technical Reports Server (NTRS)

    Callaghan, Kim A. S.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    To complement both the multi-filter observations of quasar environments described in these proceedings, as well as the proposed UBC 2.7 m Liquid Mirror Telescope (LMT) redshift survey, we have initiated a program of simulated multi-filter spectrophotometry. The goal of this work, still very much in progress, is a better quantitative assessment of the multiband technique as a viable mechanism for obtaining useful redshift and morphological class information from large scale multi-filter surveys.

  20. Revisit of the Ramp Filter

    PubMed Central

    Zeng, Gengsheng L.

    2014-01-01

    An important part of the filtered backprojection (FBP) algorithm is the ramp filter. This paper derives the discrete version of the ramp filter in the Fourier domain and studies the windowing effects. When a window function is used to control the noise, the image amplitude will be affected and reduced. A simple remedy is proposed to improve the image accuracy when a window function must be used. PMID:25729091

  1. A survey of failed post-retained restorations

    PubMed Central

    Sahafi, A.; Asmussen, E.

    2007-01-01

    Survival of endodontically treated, post-restored teeth depends on a multitude of factors, all of which are practically impossible to include in a randomized, controlled clinical study. The purpose of this survey was to characterize and analyze reported failures of post-retained restorations to identify factors critical to failure and to type of failure. A questionnaire was mailed to private practitioners in Denmark with a request to complete the questionnaire whenever a patient presented with a failed post-retained restoration. Information was gathered on factors related to the patient, the tooth, the restorative materials, and the techniques. Two-hundred and sixty questionnaires were collected from 171 practitioners over a 3-year period. Functioning time until failure varied between 3 months and 38 years. Mean survival time until failure was 11 years. Of the failed restorations, 61% had functioned for 10 years or less. Fracture of the tooth was the most common type of failure reported, followed by loosening of the post and fracture of the post. Tapered posts implied an increased risk of tooth fracture compared to loosening or fracture of the post, and the relative risk of tooth fracture increased with the functioning time until failure. Fracture of the post was more common among male than female patients. On the basis of this survey of failed post-retained restorations, it was concluded that tapered posts were associated with a higher risk of tooth fracture than were parallel-sided posts. PMID:17636353

  2. Academic success, clinical failure: struggling practices of a failing student.

    PubMed

    McGregor, Alix

    2007-11-01

    In the deficit model approach to clinical evaluation, failures to achieve established academic or clinical standards are attributed to a flawed educational process or, more commonly, to nursing students' personal characteristics. Little is known about the meaning and significance of failing to students. Their perspective is lost among the plethora of clinical-like external criteria that predict the pathway to failure. Not all nursing students can be successful, yet when failure is the outcome, students' dignity, self-worth, and future possibilities must be preserved. Through a Heideggerian interpretative reanalysis of a individual example of an academically successful nursing student who failed clinically, this article discusses the consequences of disconnection in student-faculty relationships. The theme Preserving Personhood: Closing Down on a Future of New Possibilities is presented, as well as two subthemes--Struggling as Adopting a Chameleon Cloak and Struggling as Disconnecting Relations. A deeper understanding of students' clinical failure can help explain why failure, a socially constructed phenomenon, matters to nursing. Relational pedagogical practices to guide clinical educators in helping students at risk of failing are also discussed.

  3. Evidence of structural remodeling in the dyssynchronous failing heart.

    PubMed

    Helm, Patrick A; Younes, Laurent; Beg, Mirza F; Ennis, Daniel B; Leclercq, Christophe; Faris, Owen P; McVeigh, Elliot; Kass, David; Miller, Michael I; Winslow, Raimond L

    2006-01-01

    Ventricular remodeling of both geometry and fiber structure is a prominent feature of several cardiac pathologies. Advances in MRI and analytical methods now make it possible to measure changes of cardiac geometry, fiber, and sheet orientation at high spatial resolution. In this report, we use diffusion tensor imaging to measure the geometry, fiber, and sheet architecture of eight normal and five dyssynchronous failing canine hearts, which were explanted and fixed in an unloaded state. We apply novel computational methods to identify statistically significant changes of cardiac anatomic structure in the failing and control heart populations. The results demonstrate significant regional differences in geometric remodeling in the dyssynchronous failing heart versus control. Ventricular chamber dilatation and reduction in wall thickness in septal and some posterior and anterior regions are observed. Primary fiber orientation showed no significant change. However, this result coupled with the local wall thinning in the septum implies an altered transmural fiber gradient. Further, we observe that orientation of laminar sheets become more vertical in the early-activated septum, with no significant change of sheet orientation in the late-activated lateral wall. Measured changes in both fiber gradient and sheet structure will affect both the heterogeneity of passive myocardial properties as well as electrical activation of the ventricles.

  4. Teamwork Endoscopic Endonasal Surgery in Failed External Dacryocystorhinostomy

    PubMed Central

    Yarmohammadi, Mohammad Ebrahim; Ghasemi, Hassan; Jafari, Farhad; Izadi, Pupak; Nadoushan, Mohammadreza Jalali; Chin, Narges Saghari

    2016-01-01

    Purpose: The purpose of this study was to evaluate the results of a teamwork revision endoscopic dacryocystorhinostomy (DCR) in eyes with previously failed external DCR. Methods: This retrospective study was performed on 50 failed external DCR subjects who underwent a teamwork revision endoscopic DCR by an ophthalmologist and an otolaryngologist. Paranasal sinus CT scanning was performed for each patient before the revision surgery. During surgery, any abnormal tissue noticed before silicone intubation was sent for pathological evaluation. Results: Endoscopic revision DCR was performed on 50 failed external DCR subjects with one-year follow-up. Of these, 31 were female (62%). The age range of the subjects was 18-88 years (mean: 59.98 years). Sinus CT showed at least one abnormality in 94% of cases. Revision endoscopy showed septal deviation (66%), scar formation (32%), ostium problems (28%), and sump syndrome (6%). Pathologic and clinical findings showed that chronic inflammation had a significant association with scar tissue and septal synechia (P = 0.001 and 0.008, respectively). At the final follow-up, anatomical and functional success was achieved in 45 out of 50 (90%) of subjects. Conclusion: Endoscopic revision DCR when performed as cooperation of otolaryngologists and ophthalmologists may help resolve the endonasal problems and increase the success rate. PMID:27621786

  5. Filters and supports in orthoalgebras

    NASA Astrophysics Data System (ADS)

    Foulis, D. J.; Greechie, R. J.; Rüttimann, G. T.

    1992-05-01

    An orthoalgebra, which is a natural generalization of an orthomodular lattice or poset, may be viewed as a “logic” or “proposition system” and, under a welldefined set of circumstances, its elements may be classified according to the Aristotelian modalities: necessary, impossible, possible, and contingent. The necessary propositions band together to form a local filter, that is, a set that intersects every Boolean subalgebra in a filter. In this paper, we give a coherent account of the basic theory of Orthoalgebras, define and study filters, local filters, and associated structures, and prove a version of the compactness theorem in classical algebraic logic.

  6. Spatial filtering with photonic crystals

    SciTech Connect

    Maigyte, Lina; Staliunas, Kestutis

    2015-03-15

    Photonic crystals are well known for their celebrated photonic band-gaps—the forbidden frequency ranges, for which the light waves cannot propagate through the structure. The frequency (or chromatic) band-gaps of photonic crystals can be utilized for frequency filtering. In analogy to the chromatic band-gaps and the frequency filtering, the angular band-gaps and the angular (spatial) filtering are also possible in photonic crystals. In this article, we review the recent advances of the spatial filtering using the photonic crystals in different propagation regimes and for different geometries. We review the most evident configuration of filtering in Bragg regime (with the back-reflection—i.e., in the configuration with band-gaps) as well as in Laue regime (with forward deflection—i.e., in the configuration without band-gaps). We explore the spatial filtering in crystals with different symmetries, including axisymmetric crystals; we discuss the role of chirping, i.e., the dependence of the longitudinal period along the structure. We also review the experimental techniques to fabricate the photonic crystals and numerical techniques to explore the spatial filtering. Finally, we discuss several implementations of such filters for intracavity spatial filtering.

  7. Fabric filter system study

    NASA Astrophysics Data System (ADS)

    Chambers, R. L.; Plunk, O. C.; Kunka, S. L.

    1984-08-01

    Results of the fourth year of operation of a fabric filter installed on a coal-fired boiler are reported. Project work during the fourth year concentrated on fabric studies. The 10-oz/sq yd fabrics of the 150 1/2 warp, 150 2/2T fill construction demonstrated superior performance over the most common 14-oz/sq yd constructions, regardless of coating. It was determined that improving cleaning by increasing shaking amplitude is more detrimental to baglife than increasing shaker frequency. Maintenance and operation observations continued, and the resolution of these types of problems became more efficient because of increased experience of maintenance personnel with baghouse-related problems.

  8. Quasi-periodic spatiotemporal filtering.

    PubMed

    Burghouts, Gertjan J; Geusebroek, Jan-Mark

    2006-06-01

    This paper presents the online estimation of temporal frequency to simultaneously detect and identify the quasiperiodic motion of an object. We introduce color to increase discriminative power of a reoccurring object and to provide robustness to appearance changes due to illumination changes. Spatial contextual information is incorporated by considering the object motion at different scales. We combined spatiospectral Gaussian filters and a temporal reparameterized Gabor filter to construct the online temporal frequency filter. We demonstrate the online filter to respond faster and decay faster than offline Gabor filters. Further, we show the online filter to be more selective to the tuned frequency than Gabor filters. We contribute to temporal frequency analysis in that we both identify ("what") and detect ("when") the frequency. In color video, we demonstrate the filter to detect and identify the periodicity of natural motion. The velocity of moving gratings is determined in a real world example. We consider periodic and quasiperiodic motion of both stationary and nonstationary objects. PMID:16764282

  9. Filter desulfation system and method

    DOEpatents

    Lowe, Michael D.; Robel, Wade J.; Verkiel, Maarten; Driscoll, James J.

    2010-08-10

    A method of removing sulfur from a filter system of an engine includes continuously passing an exhaust flow through a desulfation leg of the filter system during desulfation. The method also includes sensing at least one characteristic of the exhaust flow and modifying a flow rate of the exhaust flow during desulfation in response to the sensing.

  10. The double well mass filter

    SciTech Connect

    Gueroult, Renaud; Rax, Jean -Marcel; Fisch, Nathaniel J.

    2014-02-03

    Various mass filter concepts based on rotating plasmas have been suggested with the specific purpose of nuclear waste remediation. We report on a new rotating mass filter combining radial separation with axial extraction. Lastly, the radial separation of the masses is the result of a “double-well” in effective radial potential in rotating plasma with a sheared rotation profile.

  11. Filter for cleaning hot gases

    SciTech Connect

    Gresch, H.; Holter, H.; Hubner, K.; Igelbuscher, H.; Weber, E.

    1981-10-20

    In an apparatus for cleaning hot gases a filter housing has an inlet for unfiltered gas and an outlet for filtered gas. A plurality of filtered inserts are placed within the housing in a manner capable of filtering undesirable components from the gas feed stream. Each filter insert is made of a fibrous filter material. Silicic-acid glass fibers have a silicic acid content of at least 90%. Coated upon the fibers and absorbed into their pores is a metal oxide of aluminum, titanium, zirconium, cromium, nickle or cobalt. A honeycombed cage filled with high temperature resistant perlite is located within the housing between the gas inlet and the fiber inserts. The cage has an inlet and outlet external to the housing for replacing the perlite. A combustion chamber mounted in the housing has a discharge nozzle located so that the nozzle is directed at the filter inserts. Combusting materials in the chamber causes an explosive backflow of gases through the filter inserts.

  12. Digital filter synthesis computer program

    NASA Technical Reports Server (NTRS)

    Moyer, R. A.; Munoz, R. M.

    1968-01-01

    Digital filter synthesis computer program expresses any continuous function of a complex variable in approximate form as a computational algorithm or difference equation. Once the difference equation has been developed, digital filtering can be performed by the program on any input data list.

  13. BMP FILTERS: UPFLOW VS. DOWNFLOW

    EPA Science Inventory

    Filtration methods have been found to be effective in reducing pollutant levels in stormwater. The main drawback of these methods is that the filters get clogged frequently and require periodical maintenance. In stormwater treatment, because of the cost of pumping, the filters ar...

  14. Solid colloidal optical wavelength filter

    DOEpatents

    Alvarez, Joseph L.

    1992-01-01

    A solid colloidal optical wavelength filter includes a suspension of spheal particles dispersed in a coagulable medium such as a setting plastic. The filter is formed by suspending spherical particles in a coagulable medium; agitating the particles and coagulable medium to produce an emulsion of particles suspended in the coagulable medium; and allowing the coagulable medium and suspended emulsion of particles to cool.

  15. Face Recognition Using Local Quantized Patterns and Gabor Filters

    NASA Astrophysics Data System (ADS)

    Khryashchev, V.; Priorov, A.; Stepanova, O.; Nikitin, A.

    2015-05-01

    The problem of face recognition in a natural or artificial environment has received a great deal of researchers' attention over the last few years. A lot of methods for accurate face recognition have been proposed. Nevertheless, these methods often fail to accurately recognize the person in difficult scenarios, e.g. low resolution, low contrast, pose variations, etc. We therefore propose an approach for accurate and robust face recognition by using local quantized patterns and Gabor filters. The estimation of the eye centers is used as a preprocessing stage. The evaluation of our algorithm on different samples from a standardized FERET database shows that our method is invariant to the general variations of lighting, expression, occlusion and aging. The proposed approach allows about 20% correct recognition accuracy increase compared with the known face recognition algorithms from the OpenCV library. The additional use of Gabor filters can significantly improve the robustness to changes in lighting conditions.

  16. Vectorization of linear discrete filtering algorithms

    NASA Technical Reports Server (NTRS)

    Schiess, J. R.

    1977-01-01

    Linear filters, including the conventional Kalman filter and versions of square root filters devised by Potter and Carlson, are studied for potential application on streaming computers. The square root filters are known to maintain a positive definite covariance matrix in cases in which the Kalman filter diverges due to ill-conditioning of the matrix. Vectorization of the filters is discussed, and comparisons are made of the number of operations and storage locations required by each filter. The Carlson filter is shown to be the most efficient of the filters on the Control Data STAR-100 computer.

  17. Recycling used automotive oil filters

    NASA Astrophysics Data System (ADS)

    Peaslee, Kent D.

    1994-02-01

    Over 400 million used automotive oil filters are discarded in the United States each year, most of which are disposed of in landfills wasting valuable resources and risking contamination of ground- and surface-water supplies. This article summarizes U.S. bureau of Mines research evaluating scrap prepared from used automotive oil filters. Experimental results show that crushed and drained oil filters have a bulk density that is higher than many typical scrap grades, a chemical analysis low in residual elements (except tin due to use of tin plate in filters), and an overall yield, oil-filter scrap to cast steel, of 76% to 85%, depending on the method used to prepare the scrap.

  18. ITP Filter Particulate Decontamination Measurement

    SciTech Connect

    Dworjanyn, L.O.

    1993-05-21

    A new test method was developed which showed the installed In- Tank Precipitation Filter Unit {number_sign}3 provided at least 40, 000 x decontamination of the precipitated potassium tetraphenylborate (KTPB) during the cold chemical runs.This filter is expected to meet the needed 40,000 x hot cesium decontamination requirements, assuming that the cesium precipitate, CsTPB, behaves the same as KTPB. The new method permits cold chemicals field testing of installed filters to quantify particulate decontamination and verify filter integrity before going hot. The method involves a 1000 x concentration of fine particulate KTPB in the filtrate to allow direct analysis by counting for naturally radioactive isotope K-40 using the underground SRTC gamma spectroscopy facility. The particulate concentration was accomplished by ultra filtration at Rhone-Poulenc, NJ, using a small cross-flow bench facility, followed by collection of all suspended solids on a small filter disc for K analysis.

  19. Sintered composite medium and filter

    DOEpatents

    Bergman, Werner

    1987-01-01

    A particulate filter medium is formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers. A preferred composition is about 40 vol. % quartz and about 60 vol. % stainless steel fibers. The media is sintered at about 1100.degree. C. to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550.degree. C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  20. Failed magmatic eruptions: Late-stage cessation of magma ascent

    USGS Publications Warehouse

    Moran, S.C.; Newhall, C.; Roman, D.C.

    2011-01-01

    When a volcano becomes restless, a primary question is whether the unrest will lead to an eruption. Here we recognize four possible outcomes of a magmatic intrusion: "deep intrusion", "shallow intrusion", "sluggish/viscous magmatic eruption", and "rapid, often explosive magmatic eruption". We define "failed eruptions" as instances in which magma reaches but does not pass the "shallow intrusion" stage, i. e., when magma gets close to, but does not reach, the surface. Competing factors act to promote or hinder the eventual eruption of a magma intrusion. Fresh intrusion from depth, high magma gas content, rapid ascent rates that leave little time for enroute degassing, opening of pathways, and sudden decompression near the surface all act to promote eruption, whereas decreased magma supply from depth, slow ascent, significant enroute degassing and associated increases in viscosity, and impingement on structural barriers all act to hinder eruption. All of these factors interact in complex ways with variable results, but often cause magma to stall at some depth before reaching the surface. Although certain precursory phenomena, such as rapidly escalating seismic swarms or rates of degassing or deformation, are good indicators that an eruption is likely, such phenomena have also been observed in association with intrusions that have ultimately failed to erupt. A perpetual difficulty with quantifying the probability of eruption is a lack of data, particularly on instances of failed eruptions. This difficulty is being addressed in part through the WOVOdat database. Papers in this volume will be an additional resource for scientists grappling with the issue of whether or not an episode of unrest will lead to a magmatic eruption.

  1. Beneficial effects of SR33805 in failing myocardium

    PubMed Central

    Ait Mou, Younss; Toth, Attila; Cassan, Cécile; Czuriga, Daniel; de Tombe, Pieter P.; Papp, Zoltan; Lacampagne, Alain; Cazorla, Olivier

    2011-01-01

    Aims SR33805, a potent Ca2+ channel blocker, increases cardiac myofilament Ca2+ sensitivity in healthy rat cardiomyocytes. Therefore, the aim of the present study was to evaluate the effects of SR33805 on contractile properties in ischaemic failing hearts after myocardial infarction (MI) in vivo and in vitro at the cellular level. Methods and results The effect of SR33805 (10 µM) was tested on the excitation–contraction coupling of cardiomyocytes isolated from rat with end-stage heart failure. Cell shortening and Ca2+ transients were measured in intact cardiomyocytes, while contractile properties were determined in Triton X-100 permeabilized myocytes. Acute treatment with SR33805 restored the MI-altered cell shortening without affecting the Ca2+ transient amplitude, suggesting an increase of myofilament Ca2+ sensitivity in MI myocytes. Indeed, a SR33805-induced sensitization of myofilament activation was found to be associated with a slight increase in myosin light chain-2 phosphorylation and a more significant decrease on troponin I (TnI) phosphorylation. Decreased TnI phosphorylation was related to inhibition of protein kinase A activity by SR33805. Finally, administration of a single intra-peritoneal bolus of SR33805 (20 mg/kg) improved end-systolic strain and fractional shortening of MI hearts. Conclusion The present study indicates that treatment with SR33805 improved contractility of ischaemic failing hearts after MI in the rat by selectively modulating the phosphorylation status of sarcomeric regulatory proteins, which then sensitized the myofilaments to Ca2+. Our results gave a proof of concept that manipulation of the Ca2+ sensitivity of sarcomeric regulatory proteins can be used to improve contractility of a failing heart. PMID:21467075

  2. Fail-safe storage rack for irradiated fuel rod assemblies

    DOEpatents

    Lewis, Donald R.

    1993-01-01

    A fail-safe storage rack is provided for interim storage of spent but radioactive nuclear fuel rod assemblies. The rack consists of a checkerboard array of substantially square, elongate receiving tubes fully enclosed by a double walled container, the outer wall of which is imperforate for liquid containment and the inner wall of which is provided with perforations for admitting moderator liquid flow to the elongate receiving tubes, the liquid serving to take up waste heat from the stored nuclear assemblies and dissipate same to the ambient liquid reservoir. A perforated cover sealing the rack facilitates cooling liquid entry and dissipation.

  3. A Novel Endoscopic Technique for Failed Nasogastric Tube Placement.

    PubMed

    Boston, Andrew G

    2015-10-01

    Direct visualization of the nasopharynx gives the otolaryngologist a unique advantage for addressing difficult nasopharyngeal anatomy. One common situation is being consulted to assist when the blind placement of a nasogastric tube has failed. A novel technique for managing a patient with a nasogastric tube embedded in the adenoid remnant is described with illustrations. The atraumatic method is easily employed by a resident armed with a portable nasolaryngoscope and plain suture. By using a repeated pull-through technique, the nasogastric tube can be guided past difficult nasopharyngeal anatomy and into a position from where it can be advanced into the patient's esophagus.

  4. Sjögren Syndrome: Why Do Clinical Trials Fail?

    PubMed

    Fox, Robert I; Fox, Carla M

    2016-08-01

    Sjögren syndrome (SS) comprises glandular and extraglandular manifestations. Double-blind prospective trials of traditional disease-modifying antirheumatic drugs and biologics have failed because they have not improved benign symptoms, the major cause of lowered quality of life. Rituximab has proven effective in SS patients with associated mixed cryoglobulinemia, parotid gland swelling, lymphocytic interstitial pneumonitis, thrombocytopenia, and other manifestations. There were few of these SS patients in the trials required for FDA approval. Most patients had benign symptoms and did not show benefit, leading to failure of the study. This article examines the reasons for these failures and proposes future directions.

  5. Failing four-unit maxillary fixed partial denture: part 2.

    PubMed

    Vailati, Francesca

    2006-08-01

    In this two-part treatment planning series, the case of a 54-year-old woman with a failing four-unit fixed partial denture (FPD) is presented. Part 1 presented pretreatment strategies, occlusal and periodontal status, and the advantages and disadvantages of three treatment options: removable partial denture, tooth-supported FPD, and implant-supported FPD. In this follow-up article, the treatment selected for the case is revealed, and the rationale--including indications and contraindications for the different treatment options--is discussed. The treatment sequence is then outlined, and the final outcome is presented.

  6. Analysis of failed ramps during the RHIC FY09 run

    SciTech Connect

    Minty, M.

    2014-08-15

    The Relativistic Heavy Ion Collider (RHIC) is a versatile accelerator that supports operation with polarized protons of up to 250 GeV and ions with up to 100 GeV/nucleon. During any running period, various operating scenarios with different particle species, beam energies or accelerator optics are commissioned. In this report the beam commissioning periods for establishing full energy beams (ramp development periods) from the FY09 run are summarized and, for the purpose of motivating further developments, we analyze the reasons for all failed ramps.

  7. Improved Quick Disconnect (QD) Interface Through Fail Safe Parts Identification

    NASA Technical Reports Server (NTRS)

    Blanch-Payne, Evelyn

    2001-01-01

    An extensive review of existing Quick Disconnects (QDs) mating and demating operations was performed to determine which shuttle part interface identifications and procedures contribute to human factor errors. The research methods used consisted of interviews with engineers and technicians, examination of incident reports, critiques of video and audio tapes of QD operations, and attendance of a Hyper QD operational course. The data strongly suggests that there are inherit human factor errors involved in QD operations. To promote fail-safe operations, QD interface problem areas and recommendations were outlined and reviewed. It is suggested that dialogue, investigations and recommendations continue.

  8. Modeling the filtration ability of stockpiled filtering facepiece

    NASA Astrophysics Data System (ADS)

    Rottach, Dana R.

    2016-03-01

    Filtering facepiece respirators (FFR) are often stockpiled for use during public health emergencies such as an infectious disease outbreak or pandemic. While many stockpile administrators are aware of shelf life limitations, environmental conditions can lead to premature degradation. Filtration performance of a set of FFR retrieved from a storage room with failed environmental controls was measured. Though within the expected shelf life, the filtration ability of several respirators was degraded, allowing twice the penetration of fresh samples. The traditional picture of small particle capture by fibrous filter media qualitatively separates the effect of inertial impaction, interception from the streamline, diffusion, settling, and electrostatic attraction. Most of these mechanisms depend upon stable conformational properties. However, common FFR rely on electrets to achieve their high performance, and over time heat and humidity can cause the electrostatic media to degrade. An extension of the Langevin model with correlations to classical filtration concepts will be presented. The new computational model will be used to predict the change in filter effectiveness as the filter media changes with time.

  9. Planar Superconducting Millimeter-Wave/Terahertz Channelizing Filter

    NASA Technical Reports Server (NTRS)

    Ehsan, Negar; U-yen, Kongpop; Brown, Ari; Hsieh, Wen-Ting; Wollack, Edward; Moseley, Samuel

    2013-01-01

    , with 50-GHz bandwidth, were designed, each using multiple transmission line media such as microstrip, coplanar waveguide, and quasi-lumped components on 0.45- m thick silicon. In the design process, modeling issues had to be overcome. Due to the extremely high frequencies, very thin Si substrate, and the superconducting metal layers, most commercially available software fails in various ways. These issues were mitigated by using alternative software that was capable of handling them at the expense of greater simulation time. The design of on-chip components for the filter characterization, such as a broadband antenna, Wilkinson power dividers, attenuators, detectors, and transitions has been completed.

  10. Characterization of Actinomyces species isolated from failed dental implant fixtures.

    PubMed

    Sarkonen, Nanna; Könönen, Eija; Eerola, Erkki; Könönen, Mauno; Jousimies-Somer, Hannele; Laine, Pekka

    2005-08-01

    In the oral cavity, Actinomyces form a fundamental component of the indigenous microflora, being among initial colonizers in polymicrobial biofilms. However, some differences may exist between different species in terms of their attachment not only to teeth but also to biomaterials. In this study we investigated the distribution of Actinomyces in 33 dental implant fixtures explanted from 17 patients. The identification was based on comprehensive biochemical testing and gas-liquid chromatography and when needed, 16S rRNA sequencing. Actinomyces was the most prevalent bacterial genus in these failed implants, colonizing 31/33 (94%) of the fixtures. Proportions of Actinomyces growth of the total bacterial growth in the Actinomyces-positive fixtures varied from 0.01% up to 75%. A. odontolyticus was the most common Actinomyces finding, present in 26/31 (84%) Actinomyces-positive fixtures. Actinomyces naeslundii and A. viscosus were both detected in 10/31 (32%) and A. israelii in 7/31 (23%) fixtures. Other Actinomyces species, including A. georgiae, A. gerencseriae and A. graevenitzii, were detected less frequently. Our results suggest that Actinomyces species are frequent colonizers on failed implant surfaces, where A. odontolyticus was the far most prominent Actinomyces species.

  11. Adult cancer clinical trials that fail to complete: an epidemic?

    PubMed

    Stensland, Kristian D; McBride, Russell B; Latif, Asma; Wisnivesky, Juan; Hendricks, Ryan; Roper, Nitin; Boffetta, Paolo; Hall, Simon J; Oh, William K; Galsky, Matthew D

    2014-09-01

    The number and diversity of cancer therapeutics in the pipeline has increased over the past decade due to an enhanced understanding of cancer biology and the identification of novel therapeutic targets. At the same time, the cost of bringing new drugs to market and the regulatory burdens associated with clinical drug development have progressively increased. The finite number of eligible patients and limited financial resources available to evaluate promising new therapeutics represent rate-limiting factors in the effort to translate preclinical discoveries into the next generation of standard therapeutic approaches. Optimal use of resources requires understanding and ultimately addressing inefficiencies in the cancer clinical trials system. Prior analyses have demonstrated that a large proportion of trials initiated by the National Cancer Institute (NCI) Cooperative Group system are never completed. While NCI Cooperative Group trials are important, they represent only a small proportion of all cancer clinical trials performed. Herein, we explore the problem of cancer clinical trials that fail to complete within the broader cancer clinical trials enterprise. Among 7776 phase II-III adult cancer clinical trials initiated between 2005-2011, we found a seven-year cumulative incidence of failure to complete of approximately 20% (95% confidence interval = 18% to 22%). Nearly 48000 patients were enrolled in trials that failed to complete. These trials likely contribute little to the scientific knowledge base, divert resources and patients from answering other critical questions, and represent a barrier to progress.

  12. In situ repair of a failed compression fitting

    DOEpatents

    Wolbert, Ronald R.; Jandrasits, Walter G.

    1986-01-01

    A method and apparatus for the in situ repair of a failed compression fitg is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

  13. In situ repair of a failed compression fitting

    DOEpatents

    Wolbert, R.R.; Jandrasits, W.G.

    1985-08-05

    A method and apparatus for the in situ repair of a failed compression fitting is provided. Initially, a portion of a guide tube is inserted coaxially in the bore of the compression fitting and locked therein. A close fit dethreading device is then coaxially mounted on the guide tube to cut the threads from the fitting. Thereafter, the dethreading device and guide tube are removed and a new fitting is inserted onto the dethreaded fitting with the body of the new fitting overlaying the dethreaded portion. Finally, the main body of the new fitting is welded to the main body of the old fitting whereby a new threaded portion of the replacement fitting is precisely coaxial with the old threaded portion. If needed, a bushing is located on the dethreaded portion which is sized to fit snugly between the dethreaded portion and the new fitting. Preferably, the dethreading device includes a cutting tool which is moved incrementally in a radial direction whereby the threads are cut from the threaded portion of the failed fitting in increments.

  14. Untrained Chimpanzees (Pan troglodytes schweinfurthii) Fail to Imitate Novel Actions

    PubMed Central

    Tennie, Claudio; Call, Josep; Tomasello, Michael

    2012-01-01

    Background Social learning research in apes has focused on social learning in the technical (problem solving) domain - an approach that confounds action and physical information. Successful subjects in such studies may have been able to perform target actions not as a result of imitation learning but because they had learnt some technical aspect, for example, copying the movements of an apparatus (i.e., different forms of emulation learning). Methods Here we present data on action copying by non-enculturated and untrained chimpanzees when physical information is removed from demonstrations. To date, only one such study (on gesture copying in a begging context) has been conducted – with negative results. Here we have improved this methodology and have also added non-begging test situations (a possible confound of the earlier study). Both familiar and novel actions were used as targets. Prior to testing, a trained conspecific demonstrator was rewarded for performing target actions in view of observers. All but one of the tested chimpanzees already failed to copy familiar actions. When retested with a novel target action, also the previously successful subject failed to copy – and he did so across several contexts. Conclusion Chimpanzees do not seem to copy novel actions, and only some ever copy familiar ones. Due to our having tested only non-enculturated and untrained chimpanzees, the performance of our test subjects speak more than most other studies of the general (dis-)ability of chimpanzees to copy actions, and especially novel actions. PMID:22905102

  15. Recapitulating maladaptive, multiscale remodeling of failing myocardium on a chip.

    PubMed

    McCain, Megan L; Sheehy, Sean P; Grosberg, Anna; Goss, Josue A; Parker, Kevin Kit

    2013-06-11

    The lack of a robust pipeline of medical therapeutic agents for the treatment of heart disease may be partially attributed to the lack of in vitro models that recapitulate the essential structure-function relationships of healthy and diseased myocardium. We designed and built a system to mimic mechanical overload in vitro by applying cyclic stretch to engineered laminar ventricular tissue on a stretchable chip. To test our model, we quantified changes in gene expression, myocyte architecture, calcium handling, and contractile function and compared our results vs. several decades of animal studies and clinical observations. Cyclic stretch activated gene expression profiles characteristic of pathological remodeling, including decreased α- to β-myosin heavy chain ratios, and induced maladaptive changes to myocyte shape and sarcomere alignment. In stretched tissues, calcium transients resembled those reported in failing myocytes and peak systolic stress was significantly reduced. Our results suggest that failing myocardium, as defined genetically, structurally, and functionally, can be replicated in an in vitro microsystem by faithfully recapitulating the structural and mechanical microenvironment of the diseased heart.

  16. When the science fails and the ethics works: 'Fail-safe' ethics in the FEM-PrEP study.

    PubMed

    Kingori, Patricia

    2015-12-01

    This paper will explore the concept of 'fail safe' ethics in the FEM PrEP trial, and the practice of research and ethics on the ground. FEM-PrEP examined the efficacy of PrEP in African women after promising outcomes in research conducted with MSM. This was a hugely optimistic time and FEM-PrEP was mobilised using rights-based ethical arguments that women should have access to PrEP. This paper will present data collected during an ethnographic study of frontline research workers involved in FEM-PrEP. During our discussions, 'fail-safe' ethics emerged as concept that encapsulated their confidence that their ethics could not fail. However, in 2011, FEM-PrEP was halted and deemed a failure. The women involved in the study were held responsible because contrary to researcher's expectations they were not taking the oral PrEP being researched. This examination of FEM-PrEP will show that ethical arguments are increasingly deployed to mobilise, maintain and in some cases stop trials in ways which, at times, are superseded or co-opted by other interests. While promoting the interests of women, rights-based approaches are argued to indirectly justify the continuation of individualised, biomedical interventions which have been problematic in other women-centred trials. In this examination of FEM-PrEP, the rights-based approach obscured: ethical concerns beyond access to PrEP; the complexities of power relationships between donor and host countries; the operations of the HIV industry in research-saturated areas and the cumulative effect of unfilled expectations in HIV research and how this has shaped ideas of research and ethics.

  17. Performance of ceramic membrane filters

    SciTech Connect

    Ahluwalia, R.K.; Im, K.H.; Geyer, H.K.; Shelleman, D.L.; Tressler, R.E.

    1996-08-01

    CeraMem Corp.`s ceramic-membrane coated, dead-end ceramic filters offer a promising alternative to ceramic candle filters providing long-term operational and reliability issues are resolved: regenerability of filter passages by back pulse cleaning, tolerance to alkali-containing combustion gas and thermal/chemical aging. ANL is responsible for analytical modeling of filtration and pulse cleaning operations, flow-through testing, and prediction of filter response to thermal cycling under realistic service conditions. A test apparatus was built to expose ceramic filter specimens to chemical environments simulating operation of pressurized fluidized bed and integrated gasification combined cycle plants. Four long-duration tests have been conducted in which 100-cpsi channel filters were exposed to ash collected downstream of the cyclone separator at the PFBC plant at Tidd. Results are discussed. Focus has now shifted to exposing the advanced candle filter specimens to reducing gas environments containing NaCl, H{sub 2}S, H{sub 2}O, and gasification ash.

  18. Nanophotonic filters for digital imaging

    NASA Astrophysics Data System (ADS)

    Walls, Kirsty

    There has been an increasing demand for low cost, portable CMOS image sensors because of increased integration, and new applications in the automotive, mobile communication and medical industries, amongst others. Colour reproduction remains imperfect in conventional digital image sensors, due to the limitations of the dye-based filters. Further improvement is required if the full potential of digital imaging is to be realised. In alternative systems, where accurate colour reproduction is a priority, existing equipment is too bulky for anything but specialist use. In this work both these issues are addressed by exploiting nanophotonic techniques to create enhanced trichromatic filters, and multispectral filters, all of which can be fabricated on-chip, i.e. integrated into a conventional digital image sensor, to create compact, low cost, mass produceable imaging systems with accurate colour reproduction. The trichromatic filters are based on plasmonic structures. They exploit the excitation of surface plasmon resonances in arrays of subwavelength holes in metal films to filter light. The currently-known analytical expressions are inadequate for optimising all relevant parameters of a plasmonic structure. In order to obtain arbitrary filter characteristics, an automated design procedure was developed that integrated a genetic algorithm and 3D finite-difference time-domain tool. The optimisation procedure's efficacy is demonstrated by designing a set of plasmonic filters that replicate the CIE (1931) colour matching functions, which themselves mimic the human eye's daytime colour response.

  19. Properties of ceramic candle filters

    SciTech Connect

    Pontius, D.H.

    1995-06-01

    The mechanical integrity of ceramic filter elements is a key issue for hot gas cleanup systems. To meet the demands of the advanced power systems, the filter components must sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. They must also survive the various mechanical loads associated with handling and assembly, normal operation, and process upsets. For near-term filter systems, these elements must survive at operating temperatures of 1650{degrees}F for three years.

  20. Advanced simulation of digital filters

    NASA Astrophysics Data System (ADS)

    Doyle, G. S.

    1980-09-01

    An Advanced Simulation of Digital Filters has been implemented on the IBM 360/67 computer utilizing Tektronix hardware and software. The program package is appropriate for use by persons beginning their study of digital signal processing or for filter analysis. The ASDF programs provide the user with an interactive method by which filter pole and zero locations can be manipulated. Graphical output on both the Tektronix graphics screen and the Versatec plotter are provided to observe the effects of pole-zero movement.

  1. Attitude Representations for Kalman Filtering

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The four-component quaternion has the lowest dimensionality possible for a globally nonsingular attitude representation, it represents the attitude matrix as a homogeneous quadratic function, and its dynamic propagation equation is bilinear in the quaternion and the angular velocity. The quaternion is required to obey a unit norm constraint, though, so Kalman filters often employ a quaternion for the global attitude estimate and a three-component representation for small errors about the estimate. We consider these mixed attitude representations for both a first-order Extended Kalman filter and a second-order filter, as well for quaternion-norm-preserving attitude propagation.

  2. Spatial filtering through elementary examples

    NASA Astrophysics Data System (ADS)

    Gluskin, Emanuel

    2004-05-01

    The spatial filtering features of resistive grids have become important in microelectronics in the last two decades, in particular because of the current interest in the design of 'vision chips.' However, these features of the grids are unexpected for many who received a basic physics or electrical engineering education. The author's opinion is that the concept of spatial filtering is important in itself, and should be introduced and separately considered at an early educational stage. We thus discuss some simple examples, of both continuous and discrete systems in which spatial filtering may be observed, using only basic physics concepts.

  3. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests

  4. Baseline and optional bench-scale testing of a chemical candle filter safeguard device

    SciTech Connect

    Hurley, J.P.; Swanson, M.L.

    2000-11-01

    This project was undertaken by the Energy and Environmental Research Center (EERC) to design, construct, and test the feasibility of a hot-gas filter safeguard device (SGD) to prevent the release of dust in the event of candle filter failure under both pressurized fluidized-bed combustion (PFBC) (oxidizing) and integrated gasification combined cycle (IGCC) (reducing) operating conditions. The SGD must use existing filter system seals, gaskets, fixtures, and assemblies as much as possible. It must also activate quickly when a candle filter has failed, preferably preventing dust concentrations downstream of the SGD from exceeding 1 ppmw. In addition, the SGD must be able to operate in an inactive mode with minimal pressure drop, and its operation cannot be affected by repeated backpulse cleaning events of up to 3 psia and 1/2 second in duration.

  5. A tracker based on a CPHD filter approach for infrared applications

    NASA Astrophysics Data System (ADS)

    Petetin, Y.; Clark, D.; Ristic, B.; Maltese, D.

    2011-06-01

    Since the derivation of PHD filter, a number of track management schemes have been proposed to adapt the PHD filter for determining the tracks of multiple objects. Nevertheless, the problem remains that such approaches can fail when targets are too close or are crossing. In this paper, we propose to improve the tracking by maintaining a set of locally-based trackers and managing the tracks with an assignment method. Furthermore, the new algorithm is based on a Gaussian mixture implementation of the CPHD filter, by clustering neighbouring Gaussians before the update step and updating each cluster with the CPHD filter update. In order to be computationally efficient, the algorithm includes gating techniques for the local trackers and constructs local cardinality distributions for the targets and clutter within the gated regions. An improvement in multi-object estimation performance has been experienced on both synthetic and real IR data scenarios.

  6. Concrete ensemble Kalman filters with rigorous catastrophic filter divergence.

    PubMed

    Kelly, David; Majda, Andrew J; Tong, Xin T

    2015-08-25

    The ensemble Kalman filter and ensemble square root filters are data assimilation methods used to combine high-dimensional, nonlinear dynamical models with observed data. Ensemble methods are indispensable tools in science and engineering and have enjoyed great success in geophysical sciences, because they allow for computationally cheap low-ensemble-state approximation for extremely high-dimensional turbulent forecast models. From a theoretical perspective, the dynamical properties of these methods are poorly understood. One of the central mysteries is the numerical phenomenon known as catastrophic filter divergence, whereby ensemble-state estimates explode to machine infinity, despite the true state remaining in a bounded region. In this article we provide a breakthrough insight into the phenomenon, by introducing a simple and natural forecast model that transparently exhibits catastrophic filter divergence under all ensemble methods and a large set of initializations. For this model, catastrophic filter divergence is not an artifact of numerical instability, but rather a true dynamical property of the filter. The divergence is not only validated numerically but also proven rigorously. The model cleanly illustrates mechanisms that give rise to catastrophic divergence and confirms intuitive accounts of the phenomena given in past literature.

  7. Digital filtering: background and tutorial for psychophysiologists.

    PubMed

    Cook, E W; Miller, G A

    1992-05-01

    Digital filtering offers more to psychophysiologists than is commonly appreciated. An introduction is offered here to foster the explicit design and use of digital filters. Because of considerable confusion in the literature about terminology important to both analog and digital filtering, basic concepts are reviewed and clarified. Because some time series concepts are fundamental to digital filtering, these are also presented. Examples of filters commonly used in psychophysiology are given, and procedures are presented for the design and use of one type of digital filter. Properties of some types of digital filters are described, and the relative advantages of simple analog and digital filters are discussed.

  8. Biometric verification with correlation filters.

    PubMed

    Vijaya Kumar, B V K; Savvides, Marios; Xie, Chunyan; Venkataramani, Krithika; Thornton, Jason; Mahalanobis, Abhijit

    2004-01-10

    Using biometrics for subject verification can significantly improve security over that of approaches based on passwords and personal identification numbers, both of which people tend to lose or forget. In biometric verification the system tries to match an input biometric (such as a fingerprint, face image, or iris image) to a stored biometric template. Thus correlation filter techniques are attractive candidates for the matching precision needed in biometric verification. In particular, advanced correlation filters, such as synthetic discriminant function filters, can offer very good matching performance in the presence of variability in these biometric images (e.g., facial expressions, illumination changes, etc.). We investigate the performance of advanced correlation filters for face, fingerprint, and iris biometric verification. PMID:14735958

  9. When Technical Rationality Fails: Thinking about Terminally Ill Patients.

    PubMed

    Still, A; Todd, C

    1998-01-01

    The theory that thinking is modelled on the social activity of argument is investigated through the views of general practitioners about terminally ill patients. The social activity of general practice centres on the consultation, which the doctor manages by 'technical rationality'. But this is difficult when the patient is terminally ill. In that case technical rationality is seen to fail and rhetorical skills are invoked. GPs' thinking about such consultations can be described using an agonistic model based on a hierarchy of objectives, strategies and tactics. The objective of keeping patients comfortable and dignified is aimed at through three strategies, and a variety of rhetorical tactics is drawn on in thinking about these strategies.

  10. [Multimodal therapy concepts for failed back surgery syndrome].

    PubMed

    Casser, Hans-Raimund

    2016-09-01

    Failed back surgery syndrome (FBSS) is a frequent complication (15-40 %) of lumbar disc surgery and is rarely successfully treated by surgery with the exception of a re-prolapse associated with radicular pain. Multimodal pain treatment, however, is indicated by a lack of pathoanatomical correlates, unclear cause and psychosocial risk factors.This review describes a standardized non-operative treatment starting with broad interdisciplinary clarification by medical, psychological and physiotherapeutic means (assessment).If the conditions for multimodal pain therapy are met, the OPS 8‑918-procedure can be applied to avoid chronic developing pain. In doing so, the already issued quality standards and guidelines for documentation should be respected. PMID:27514828

  11. Do organic and other exotic superconductors fail universal scaling relations?

    PubMed Central

    Dordevic, S. V.; Basov, D. N.; Homes, C. C.

    2013-01-01

    Universal scaling relations are of tremendous importance in science, as they reveal fundamental laws of nature. Several such scaling relations have recently been proposed for superconductors; however, they are not really universal in the sense that some important families of superconductors appear to fail the scaling relations, or obey the scaling with different scaling pre-factors. In particular, a large group of materials called organic (or molecular) superconductors are a notable example. Here, we show that such apparent violations are largely due to the fact that the required experimental parameters were collected on different samples, with different experimental techniques. When experimental data is taken on the same sample, using a single experimental technique, organic superconductors, as well as all other studied superconductors, do in fact follow universal scaling relations.

  12. Unaware person recognition from the body when face identification fails.

    PubMed

    Rice, Allyson; Phillips, P Jonathon; Natu, Vaidehi; An, Xiaobo; O'Toole, Alice J

    2013-11-01

    How does one recognize a person when face identification fails? Here, we show that people rely on the body but are unaware of doing so. State-of-the-art face-recognition algorithms were used to select images of people with almost no useful identity information in the face. Recognition of the face alone in these cases was near chance level, but recognition of the person was accurate. Accuracy in identifying the person without the face was identical to that in identifying the whole person. Paradoxically, people reported relying heavily on facial features over noninternal face and body features in making their identity decisions. Eye movements indicated otherwise, with gaze duration and fixations shifting adaptively toward the body and away from the face when the body was a better indicator of identity than the face. This shift occurred with no cost to accuracy or response time. Human identity processing may be partially inaccessible to conscious awareness.

  13. Sensitivity to metals in 40 patients with failed hip endoprosthesis.

    PubMed

    Milavec-Puretić, V; Orlić, D; Marusić, A

    1998-01-01

    Hypersensitivity to metals and tissue reaction around a failed implant were investigated in 40 patients undergoing revision hip arthroplasty. Metal sensitivity was tested using a standard cutaneous patch test. Nine patients were positive for chromium, nickel, cobalt, metal rust or endoprosthesis scrapings, or combinations of these allergens. Patients with positive or negative patch test did not differ in terms of their age, sex, primary diagnosis, number of endoprosthesis revisions, length of implant function, presence of other metal parts around the implant, circulating immunocomplexes, and histological appearance of the tissue around the implant. We conclude that stainless steel endoprostheses may be safely used for repeated revision hip arthroplasty, and that hypersensitivity to metals probably does not play a significant role in the loosening of the endoprosthesis.

  14. Behavior of Puerto Rican parrots during failed nesting attempts

    USGS Publications Warehouse

    Wilson, K.A.; Wilson, M.H.; Field, R.

    1997-01-01

    We compared patterns of nesting behavior of four pairs of Puerto Rican Parrots (Amazona vittata) that experienced failed nesting attempts to behavior of four pairs of parrots that experienced no substantial nest problems and successfully fledged young without management intervention. Only changes in female parrots' behavior were clearly associated with nest failure. During incubation, decreases in nest attendance, increases in duration of recesses, and increases in frequency of nest entries by female parrots were associated with imminent abandonment of nests. During early chick rearing, similar behavior was associated with the loss of broods. Low nest attendance and long recesses by female parrots during incubation were also associated with successful hatching of eggs followed by death of young several days later. The behavior patterns and changes in Puerto Rican Parrot nesting behavior described in this paper may alert biologists to nest problems that might be mitigated by management intervention.

  15. Surgical Approach After Failed Enteryx Injection for GERD

    PubMed Central

    Alzahrani, A.; Anvari, M.; Dallemagne, B.; Mutter, D.

    2007-01-01

    Objective: We report on 3 patients who underwent laparoscopic antireflux procedures for persistent symptoms of GERD after biopolymer injection. Methods: Experienced laparoscopic surgeons completed all 3 procedures laparoscopically. In 2 patients, there was an extramural extravasation of the polymer outside and adherent to the esophageal wall. In these patients, a partial posterior fundoplication was used. The third patient, who had the polymer material deposits removed preoperatively by endoscopic mucosal resection, underwent a Nissen fundoplication. Results: Postoperative recovery was uneventful in all cases. At follow-up of 6 to 12 months, all patients were symptom free, off medical therapy, and experiencing no dysphagia. Conclusion: Surgical therapy for patients after failed biopolymer injection is safe and effective. The choice of surgery may depend on whether the polymer mass can be removed preoperatively. PMID:17651566

  16. Optimised to Fail: Card Readers for Online Banking

    NASA Astrophysics Data System (ADS)

    Drimer, Saar; Murdoch, Steven J.; Anderson, Ross

    The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

  17. Pass-Fail Testing: Statistical Requirements and Interpretations

    PubMed Central

    Gilliam, David; Leigh, Stefan; Rukhin, Andrew; Strawderman, William

    2009-01-01

    Performance standards for detector systems often include requirements for probability of detection and probability of false alarm at a specified level of statistical confidence. This paper reviews the accepted definitions of confidence level and of critical value. It describes the testing requirements for establishing either of these probabilities at a desired confidence level. These requirements are computable in terms of functions that are readily available in statistical software packages and general spreadsheet applications. The statistical interpretations of the critical values are discussed. A table is included for illustration, and a plot is presented showing the minimum required numbers of pass-fail tests. The results given here are applicable to one-sided testing of any system with performance characteristics conforming to a binomial distribution. PMID:27504221

  18. Mutuality: clinical and metapsychological potentials of a failed experiment.

    PubMed

    Castillo Mendoza, Carlos Alberto

    2012-03-01

    Ferenczi's experiments with mutual analysis are often dismissed, without acknowledging the results obtained from them and his own cautionary remarks about their limits. Though ultimately failed, Ferenczi's experiments with mutual analysis were a source of clinical and metapsychological knowledge, despite the fact that he was unable to elaborate them in his lifetime. In this paper I connect mutuality to the development of the psyche, especially to the constitutive core of the intrapsychic. To understand the latter, it is necessary to take into account, among others, issues such as the common attribute, the mutual flux between the unconsciouses, the dialogue of unconsciouses, the maternal profundity, the primal relationship with the mother, and, above all, the primal unity between mother and child, which are fundamental for the emergence and development of the primary psychic forces. Incidences of rupture, distortion of the core of mutuality in the psychic life, its loss and disadjustment, by means of external traumatizing forces, and some clinical implications are described.

  19. Why did ISO 9001:2008 system fail to deliver?

    PubMed

    Langford, Melvyn

    2014-02-01

    This article is based on an actual investigation undertaken, and summarises the subsequent report's findings and observations. It has been anonymised for obvious reasons. In May 2013 an analysis was undertaken by a multidisciplinary team that compared an NHS Trust estates department's managerial systems against the NHS national recommendations. The conclusions stated that: 'There was a systemic failure across a large number of topics generating intolerable/substantial risks to the organisation, its staff, and patients; this despite the department's managerial systems being accredited to the International Standard ISO 9001:2008'. The natural question raised when presented with this demonstrable and auditable evidence was: 'Why did the ISO 9001:2008 system fail?'

  20. Pass-Fail Testing: Statistical Requirements and Interpretations.

    PubMed

    Gilliam, David; Leigh, Stefan; Rukhin, Andrew; Strawderman, William

    2009-01-01

    Performance standards for detector systems often include requirements for probability of detection and probability of false alarm at a specified level of statistical confidence. This paper reviews the accepted definitions of confidence level and of critical value. It describes the testing requirements for establishing either of these probabilities at a desired confidence level. These requirements are computable in terms of functions that are readily available in statistical software packages and general spreadsheet applications. The statistical interpretations of the critical values are discussed. A table is included for illustration, and a plot is presented showing the minimum required numbers of pass-fail tests. The results given here are applicable to one-sided testing of any system with performance characteristics conforming to a binomial distribution.

  1. Helical motion during a failed eruption of a filament

    NASA Astrophysics Data System (ADS)

    Liu, J.; Zhang, Q.; Wang, Y.

    2012-12-01

    Solar magnetized "tornadoes" in different scales with varying lifetime have been widely reported and discussed recently. They are found to be possibly related to the formation of prominences and coronal heating. However, the physical details of the tornadoes still remain unclear, though lots of work including observational analysis in varies wavelengths and numerical simulations have been done. Here, we report a failed eruption of a filament on 2012 July 8, during which rotating motion of the filament materials can be clearly recognized. Based on the multi-wavelength and multi-viewpoints observations from SDO and STEREO spacecraft, we tentatively think that the highly twist magnetic field lines in the filament probably lead to the helical motion of the ejected plasma. A detailed analysis will give us more information.

  2. Detonating Failed Deflagration Model of Thermonuclear Supernovae. I. Explosion Dynamics

    NASA Astrophysics Data System (ADS)

    Plewa, Tomasz

    2007-03-01

    We present a detonating failed deflagration model of Type Ia supernovae. In this model, the thermonuclear explosion of a massive white dwarf follows an off-center deflagration. We conduct a survey of asymmetric ignition configurations initiated at various distances from the stellar center. In all cases studied, we find that only a small amount of stellar fuel is consumed during deflagration phase, no explosion is obtained, and the released energy is mostly wasted on expanding the progenitor. Products of the failed deflagration quickly reach the stellar surface, polluting and strongly disturbing it. These disturbances eventually evolve into small and isolated shock-dominated regions that are rich in fuel. We consider these regions as seeds capable of forming self-sustained detonations that, ultimately, result in the thermonuclear supernova explosion. Preliminary nucleosynthesis results indicate that the model supernova ejecta are typically composed of about 0.1-0.25 Msolar of silicon group elements and 0.9-1.2 Msolar of iron group elements and are essentially carbon-free. The ejecta have a composite morphology, are chemically stratified, and display a modest amount of intrinsic asymmetry. The innermost layers are slightly egg shaped with the axis ratio ~1.2-1.3 and dominated by the products of silicon burning. This central region is surrounded by a shell of silicon group elements. The outermost layers of ejecta are highly inhomogeneous and contain products of incomplete oxygen burning with only small admixture of unburned stellar material. The explosion energies are ~(1.3-1.5)×1051 ergs.

  3. Westinghouse advanced particle filter system

    SciTech Connect

    Lippert, T.E.; Bruck, G.J.; Sanjana, Z.N.; Newby, R.A.

    1995-11-01

    Integrated Gasification Combined Cycles (IGCC), Pressurized Fluidized Bed Combustion (PFBC) and Advanced PFBC (APFB) are being developed and demonstrated for commercial power generation application. Hot gas particulate filters are key components for the successful implementation of IGCC, PFBC and APFB in power generation gas turbine cycles. The objective of this work is to develop and qualify through analysis and testing a practical hot gas ceramic barrier filter system that meets the performance and operational requirements of these advanced, solid fuel power generation cycles.

  4. Aquatic Plants Aid Sewage Filter

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  5. Floating filters, a novel technique for isolation and enumeration of fastidious, acidophilic, iron-oxidizing, autotrophic bacteria. [Thiobacillus ferrooxidans

    SciTech Connect

    De Bruyn, J.C.; Boogerd, F.C.; Bos, P.; Kuenen, J.G. )

    1990-09-01

    Nuclepore polycarbonate filters floating on a liquid, FeSO{sub 4}-containing medium (pH 1.6) were used to isolate a moderately thermophilic bacterium from a pyrite-oxidizing enrichment culture. The isolate failed to grow on any of the conventional solid media tried. To test the general applicability of the method, the enumeration of a fastidious acidophilic organism, Thiobacillus ferrooxidans, was carried out and the results compared with those obtained with other filters, solid media, and the most probable number technique. T. ferrooxidans showed better viability on the floating polycarbonate filters and grew in a much shorter time (4 to 5 days) than with the other techniques.

  6. Human-manipulator interface using particle filter.

    PubMed

    Du, Guanglong; Zhang, Ping; Wang, Xueqian

    2014-01-01

    This paper utilizes a human-robot interface system which incorporates particle filter (PF) and adaptive multispace transformation (AMT) to track the pose of the human hand for controlling the robot manipulator. This system employs a 3D camera (Kinect) to determine the orientation and the translation of the human hand. We use Camshift algorithm to track the hand. PF is used to estimate the translation of the human hand. Although a PF is used for estimating the translation, the translation error increases in a short period of time when the sensors fail to detect the hand motion. Therefore, a methodology to correct the translation error is required. What is more, to be subject to the perceptive limitations and the motor limitations, human operator is hard to carry out the high precision operation. This paper proposes an adaptive multispace transformation (AMT) method to assist the operator to improve the accuracy and reliability in determining the pose of the robot. The human-robot interface system was experimentally tested in a lab environment, and the results indicate that such a system can successfully control a robot manipulator. PMID:24757430

  7. Human-manipulator interface using particle filter.

    PubMed

    Du, Guanglong; Zhang, Ping; Wang, Xueqian

    2014-01-01

    This paper utilizes a human-robot interface system which incorporates particle filter (PF) and adaptive multispace transformation (AMT) to track the pose of the human hand for controlling the robot manipulator. This system employs a 3D camera (Kinect) to determine the orientation and the translation of the human hand. We use Camshift algorithm to track the hand. PF is used to estimate the translation of the human hand. Although a PF is used for estimating the translation, the translation error increases in a short period of time when the sensors fail to detect the hand motion. Therefore, a methodology to correct the translation error is required. What is more, to be subject to the perceptive limitations and the motor limitations, human operator is hard to carry out the high precision operation. This paper proposes an adaptive multispace transformation (AMT) method to assist the operator to improve the accuracy and reliability in determining the pose of the robot. The human-robot interface system was experimentally tested in a lab environment, and the results indicate that such a system can successfully control a robot manipulator.

  8. Sub-wavelength efficient polarization filter (SWEP filter)

    DOEpatents

    Simpson, Marcus L.; Simpson, John T.

    2003-12-09

    A polarization sensitive filter includes a first sub-wavelength resonant grating structure (SWS) for receiving incident light, and a second SWS. The SWS are disposed relative to one another such that incident light which is transmitted by the first SWS passes through the second SWS. The filter has a polarization sensitive resonance, the polarization sensitive resonance substantially reflecting a first polarization component of incident light while substantially transmitting a second polarization component of the incident light, the polarization components being orthogonal to one another. A method for forming polarization filters includes the steps of forming first and second SWS, the first and second SWS disposed relative to one another such that a portion of incident light applied to the first SWS passes through the second SWS. A method for separating polarizations of light, includes the steps of providing a filter formed from a first and second SWS, shining incident light having orthogonal polarization components on the first SWS, and substantially reflecting one of the orthogonal polarization components while substantially transmitting the other orthogonal polarization component. A high Q narrowband filter includes a first and second SWS, the first and second SWS are spaced apart a distance being at least one half an optical wavelength.

  9. A hairy case: The evolution of filtering carnivorous Drusinae (Limnephilidae, Trichoptera).

    PubMed

    Vitecek, Simon; Graf, Wolfram; Previšić, Ana; Kučinić, Mladen; Oláh, János; Bálint, Miklós; Keresztes, Lujza; Pauls, Steffen U; Waringer, Johann

    2015-12-01

    The caddisfly subfamily Drusinae BANKS comprises roughly 100 species inhabiting mountain ranges in Europe, Asia Minor and the Caucasus. A 3-gene phylogeny of the subfamily previously identified three major clades that were corroborated by larval morphology and feeding ecologies: scraping grazers, omnivorous shredders and filtering carnivores. Larvae of filtering carnivores exhibit unique head capsule complexities, unknown from other caddisfly larvae. Here we assess the species-level relationships within filtering carnivores, hypothesizing that head capsule complexity is derived from simple shapes observed in the other feeding groups. We summarize the current systematics and taxonomy of the group, clarify the systematic position of Cryptothrix nebulicola, and present a larval key to filtering carnivorous Drusinae. We infer relationships of all known filtering carnivorous Drusinae and 34 additional Drusinae species using Bayesian species tree analysis and concatenated Bayesian phylogenetic analysis of 3805bp of sequence data from six gene regions (mtCOI5-P, mtCOI3-P, 16S mrDNA, CADH, WG, 28S nrDNA), morphological cladistics from 308 characters, and a total evidence analysis. All analyses support monophyly of the three feeding ecology groups but fail to fully resolve internal relationships. Within filtering carnivores, variation in head setation and frontoclypeus structure may be associated with progressive niche adaptation, with less complex species recovered at a basal position. We propose that diversification of complex setation and frontoclypeus shape represents a recent evolutionary development, hypothetically enforcing speciation and niche specificity within filtering carnivorous Drusinae. PMID:26265260

  10. 40 CFR 205.160-6 - Passing or failing under SEA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.160-6 Passing or failing under... emission standard in § 205.152. (b) The number of failing vehicles in a sample determines whether...

  11. Io's Sodium Cloud (Clear Filter)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image of Jupiter's moon Io and its surrounding sky is shown in false color. It was taken at 5 hours 30 minutes Universal Time on Nov. 9, 1996 by the solid state imaging (CCD) system aboard NASA's Galileo spacecraft, using a clear filter whose wavelength range was approximately 400 to 1100 nanometers. This picture differs in two main ways from the green-yellow filter image of the same scene which was released yesterday.

    First, the sky around Io is brighter, partly because the wider wavelength range of the clear filter lets in more scattered light from Io's illuminated crescent and from Prometheus' sunlit plume. Nonetheless, the overall sky brightness in this frame is comparable to that seen through the green-yellow filter, indicating that even here much of the diffuse sky emission is coming from the wavelength range of the green-yellow filter (i.e., from Io's Sodium Cloud).

    The second major difference is that a quite large roundish spot has appeared in Io's southern hemisphere. This spot -- which has been colored red -- corresponds to thermal emission from the volcano Pele. The green-yellow filter image bears a much smaller trace of this emission because the clear filter is far more sensitive to those relatively long wavelengths where thermal emission is strongest.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  12. Pixelated filters for spatial imaging

    NASA Astrophysics Data System (ADS)

    Mathieu, Karine; Lequime, Michel; Lumeau, Julien; Abel-Tiberini, Laetitia; Savin De Larclause, Isabelle; Berthon, Jacques

    2015-10-01

    Small satellites are often used by spatial agencies to meet scientific spatial mission requirements. Their payloads are composed of various instruments collecting an increasing amount of data, as well as respecting the growing constraints relative to volume and mass; So small-sized integrated camera have taken a favored place among these instruments. To ensure scene specific color information sensing, pixelated filters seem to be more attractive than filter wheels. The work presented here, in collaboration with Institut Fresnel, deals with the manufacturing of this kind of component, based on thin film technologies and photolithography processes. CCD detectors with a pixel pitch about 30 μm were considered. In the configuration where the matrix filters are positioned the closest to the detector, the matrix filters are composed of 2x2 macro pixels (e.g. 4 filters). These 4 filters have a bandwidth about 40 nm and are respectively centered at 550, 700, 770 and 840 nm with a specific rejection rate defined on the visible spectral range [500 - 900 nm]. After an intense design step, 4 thin-film structures have been elaborated with a maximum thickness of 5 μm. A run of tests has allowed us to choose the optimal micro-structuration parameters. The 100x100 matrix filters prototypes have been successfully manufactured with lift-off and ion assisted deposition processes. High spatial and spectral characterization, with a dedicated metrology bench, showed that initial specifications and simulations were globally met. These excellent performances knock down the technological barriers for high-end integrated specific multi spectral imaging.

  13. Medical literature, vena cava filters and evidence of efficacy. A descriptive review.

    PubMed

    Girard, Philippe; Meyer, Guy; Parent, Florence; Mismetti, Patrick

    2014-04-01

    Up to 15% of all patients with venous thromboembolism (VTE) receive an inferior vena cava filter, and prophylactic placements are increasing. To determine whether current use of filters is based on robust evidence, a global review of the recent (2001-2012) literature on filters was undertaken. The MEDLINE database was searched for articles related to filters appearing during the period 2001-2012, updating a prior search of literature from 1975-2001. All retrieved articles were analysed, classified into predetermined categories and compared to the prior analysis; randomised and large (>100 patients with a filter) comparative non-randomised clinical studies were read in full. The 651 articles, vs 568 in the period 1975-2000, consisted mainly of retrospective series (37.8%), case reports (31.7%), reviews (14.7%, vs 6.7%, p<0.001), animal and/or in vitro studies (7.5%, vs 12.9%, p=0.002), and prospective series or trials (4.9%, vs 7.4%, p=0.07). Of 4 new randomised trials (RCT), none were designed to test the efficacy of the device; to date, only one RCT has attempted to ascertain efficacy, occurring during the period 1975-2000. Eleven large non-randomised studies compared clinical outcomes of patients with and without filters, in VTE patients (n=5) or prophylactic indications (n=6); two studies found statistically significant relationships between filter use and lower mortality rates, though none could demonstrate a causal relationship. Hence, the plethoric literature on filters parallels growing experience with these devices, but still fails to provide reliable evidence that filter use improves relevant clinical outcomes. No indication for filter placement is based on appropriate scientific evidence.

  14. 21 CFR 211.72 - Filters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Filters. 211.72 Section 211.72 Food and Drugs FOOD... GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Equipment § 211.72 Filters. Filters for liquid... shall not release fibers into such products. Fiber-releasing filters may be used when it is not...

  15. Quick-Change Optical-Filter Holder

    NASA Technical Reports Server (NTRS)

    Leone, Peter

    1988-01-01

    Dark slide and interlock protect against ambient light. Quick-change filter holder contains interlocking mechanism preventing simultaneous removal of both dark slide and filter drawer. Designed for use with Band pass optical filters in 10 channels leading to photomultiplier tubes in water-vapor lidar/ozone instrument, mechanism can be modified to operate in other optical systems requiring optical change in filters.

  16. Water washable stainless steel HEPA filter

    DOEpatents

    Phillips, Terrance D.

    2001-01-01

    The invention is a high efficiency particulate (HEPA) filter apparatus and system, and method for assaying particulates. The HEPA filter provides for capture of 99.99% or greater of particulates from a gas stream, with collection of particulates on the surface of the filter media. The invention provides a filter system that can be cleaned and regenerated in situ.

  17. Filtering theory applied to orbit determination

    NASA Technical Reports Server (NTRS)

    Torroglosa, V.

    1973-01-01

    Modifications to the extended Kalman filter and the Jazwinski filter are made and compared with the classical extended Kalman filter in applications to orbit determination using real data. The results show that with the kind of data available today, the application of filtering theories in this field presents many problems.

  18. Clinical prediction rules for failed nonoperative reduction of intussusception

    PubMed Central

    Khorana, Jiraporn; Patumanond, Jayanton; Ukarapol, Nuthapong; Laohapensang, Mongkol; Visrutaratna, Pannee; Singhavejsakul, Jesda

    2016-01-01

    Purpose The nonoperative reduction of intussusception in children can be performed safely if there are no contraindications. Many risk factors associated with failed reduction were defined. The aim of this study was to develop a scoring system for predicting the failure of nonoperative reduction using various determinants. Patients and methods The data were collected from Chiang Mai University Hospital and Siriraj Hospital from January 2006 to December 2012. Inclusion criteria consisted of patients with intussusception aged 0–15 years with no contraindications for nonoperative reduction. The clinical prediction rules were developed using significant risk factors from the multivariable analysis. Results A total of 170 patients with intussusception were included in the study. In the final analysis model, 154 patients were used for identifying the significant risk factors of failure of reduction. Ten factors clustering by the age of 3 years were identified and used for developing the clinical prediction rules, and the factors were as follows: body weight <12 kg (relative risk [RR] =1.48, P=0.004), duration of symptoms >48 hours (RR =1.26, P<0.001), vomiting (RR =1.63, P<0.001), rectal bleeding (RR =1.50, P<0.001), abdominal distension (RR =1.60, P=0.003), temperature >37.8°C (RR =1.51, P<0.001), palpable mass (RR =1.26, P<0.001), location of mass (left over right side RR =1.48, P<0.001), ultrasound showed poor prognostic signs (RR =1.35, P<0.001), and the method of reduction (hydrostatic over pneumatic, RR =1.34, P=0.023). Prediction scores ranged from 0 to 16. A high-risk group (scores 12–16) predicted a greater chance of reduction failure (likelihood ratio of positive [LR+] =18.22, P<0.001). A low-risk group (score 0–11) predicted a lower chance of reduction failure (LR+ =0.79, P<0.001). The performance of the scoring model was 80.68% (area under the receiver operating characteristic curve). Conclusion This scoring guideline was used to predict the results of

  19. Clinical prediction rules for failed nonoperative reduction of intussusception

    PubMed Central

    Khorana, Jiraporn; Patumanond, Jayanton; Ukarapol, Nuthapong; Laohapensang, Mongkol; Visrutaratna, Pannee; Singhavejsakul, Jesda

    2016-01-01

    Purpose The nonoperative reduction of intussusception in children can be performed safely if there are no contraindications. Many risk factors associated with failed reduction were defined. The aim of this study was to develop a scoring system for predicting the failure of nonoperative reduction using various determinants. Patients and methods The data were collected from Chiang Mai University Hospital and Siriraj Hospital from January 2006 to December 2012. Inclusion criteria consisted of patients with intussusception aged 0–15 years with no contraindications for nonoperative reduction. The clinical prediction rules were developed using significant risk factors from the multivariable analysis. Results A total of 170 patients with intussusception were included in the study. In the final analysis model, 154 patients were used for identifying the significant risk factors of failure of reduction. Ten factors clustering by the age of 3 years were identified and used for developing the clinical prediction rules, and the factors were as follows: body weight <12 kg (relative risk [RR] =1.48, P=0.004), duration of symptoms >48 hours (RR =1.26, P<0.001), vomiting (RR =1.63, P<0.001), rectal bleeding (RR =1.50, P<0.001), abdominal distension (RR =1.60, P=0.003), temperature >37.8°C (RR =1.51, P<0.001), palpable mass (RR =1.26, P<0.001), location of mass (left over right side RR =1.48, P<0.001), ultrasound showed poor prognostic signs (RR =1.35, P<0.001), and the method of reduction (hydrostatic over pneumatic, RR =1.34, P=0.023). Prediction scores ranged from 0 to 16. A high-risk group (scores 12–16) predicted a greater chance of reduction failure (likelihood ratio of positive [LR+] =18.22, P<0.001). A low-risk group (score 0–11) predicted a lower chance of reduction failure (LR+ =0.79, P<0.001). The performance of the scoring model was 80.68% (area under the receiver operating characteristic curve). Conclusion This scoring guideline was used to predict the results of

  20. Multiresolution Bilateral Filtering for Image Denoising

    PubMed Central

    Zhang, Ming; Gunturk, Bahadir K.

    2008-01-01

    The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges; it has shown to be an effective image denoising technique. An important issue with the application of the bilateral filter is the selection of the filter parameters, which affect the results significantly. There are two main contributions of this paper. The first contribution is an empirical study of the optimal bilateral filter parameter selection in image denoising applications. The second contribution is an extension of the bilateral filter: multiresolution bilateral filter, where bilateral filtering is applied to the approximation (low-frequency) subbands of a signal decomposed using a wavelet filter bank. The multiresolution bilateral filter is combined with wavelet thresholding to form a new image denoising framework, which turns out to be very effective in eliminating noise in real noisy images. Experimental results with both simulated and real data are provided. PMID:19004705

  1. Spatial filters for high power lasers

    DOEpatents

    Erlandson, Alvin Charles; Bayramian, Andrew James

    2014-12-02

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first longitudinal slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second longitudinal slit filter positioned between the second pair of cylindrical lenses.

  2. The use of filter media to determine filter cleanliness

    NASA Astrophysics Data System (ADS)

    Van Staden, S. J.; Haarhoff, J.

    It is general believed that a sand filter starts its life with new, perfectly clean media, which becomes gradually clogged with each filtration cycle, eventually getting to a point where either head loss or filtrate quality starts to deteriorate. At this point the backwash cycle is initiated and, through the combined action of air and water, returns the media to its original perfectly clean state. Reality, however, dictates otherwise. Many treatment plants visited a decade or more after commissioning are found to have unacceptably dirty filter sand and backwash systems incapable of returning the filter media to a desired state of cleanliness. In some cases, these problems are common ones encountered in filtration plants but many reasons for media deterioration remain elusive, falling outside of these common problems. The South African conditions of highly eutrophic surface waters at high temperatures, however, exacerbate the problems with dirty filter media. Such conditions often lead to the formation of biofilm in the filter media, which is shown to inhibit the effective backwashing of sand and carbon filters. A systematic investigation into filter media cleanliness was therefore started in 2002, ending in 2005, at the University of Johannesburg (the then Rand Afrikaans University). This involved media from eight South African Water Treatment Plants, varying between sand and sand-anthracite combinations and raw water types from eutrophic through turbid to low-turbidity waters. Five states of cleanliness and four fractions of specific deposit were identified relating to in situ washing, column washing, cylinder inversion and acid-immersion techniques. These were measured and the results compared to acceptable limits for specific deposit, as determined in previous studies, though expressed in kg/m 3. These values were used to determine the state of the filters. In order to gain greater insight into the composition of the specific deposits stripped from the media, a

  3. Modal Filters for Infrared Interferometry

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander; MacDonald, Daniel R.; Soibel, Alexander

    2009-01-01

    Modal filters in the approximately equal to 10-micrometer spectral range have been implemented as planar dielectric waveguides in infrared interferometric applications such as searching for Earth-like planets. When looking for a small, dim object ("Earth") in close proximity to a large, bright object ("Sun"), the interferometric technique uses beams from two telescopes combined with a 180 phase shift in order to cancel the light from a brighter object. The interferometer baseline can be adjusted so that, at the same time, the light from the dimmer object arrives at the combiner in phase. This light can be detected and its infrared (IR) optical spectra can be studied. The cancellation of light from the "Sun" to approximately equal to 10(exp 6) is required; this is not possible without special devices-modal filters- that equalize the wavefronts arriving from the two telescopes. Currently, modal filters in the approximately equal to 10-micrometer spectral range are implemented as single- mode fibers. Using semiconductor technology, single-mode waveguides for use as modal filters were fabricated. Two designs were implemented: one using an InGaAs waveguide layer matched to an InP substrate, and one using InAlAs matched to an InP substrate. Photon Design software was used to design the waveguides, with the main feature all designs being single-mode operation in the 10.5- to 17-micrometer spectral range. Preliminary results show that the filter's rejection ratio is 26 dB.

  4. GPU Accelerated Vector Median Filter

    NASA Technical Reports Server (NTRS)

    Aras, Rifat; Shen, Yuzhong

    2011-01-01

    Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median filtering. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median filter is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median filter implementation on GPUs over CPU implementations and further speed-up is expected after more extensive optimizations of the GPU algorithm .

  5. Organism-level models: When mechanisms and statistics fail us

    NASA Astrophysics Data System (ADS)

    Phillips, M. H.; Meyer, J.; Smith, W. P.; Rockhill, J. K.

    2014-03-01

    Purpose: To describe the unique characteristics of models that represent the entire course of radiation therapy at the organism level and to highlight the uses to which such models can be put. Methods: At the level of an organism, traditional model-building runs into severe difficulties. We do not have sufficient knowledge to devise a complete biochemistry-based model. Statistical model-building fails due to the vast number of variables and the inability to control many of them in any meaningful way. Finally, building surrogate models, such as animal-based models, can result in excluding some of the most critical variables. Bayesian probabilistic models (Bayesian networks) provide a useful alternative that have the advantages of being mathematically rigorous, incorporating the knowledge that we do have, and being practical. Results: Bayesian networks representing radiation therapy pathways for prostate cancer and head & neck cancer were used to highlight the important aspects of such models and some techniques of model-building. A more specific model representing the treatment of occult lymph nodes in head & neck cancer were provided as an example of how such a model can inform clinical decisions. A model of the possible role of PET imaging in brain cancer was used to illustrate the means by which clinical trials can be modelled in order to come up with a trial design that will have meaningful outcomes. Conclusions: Probabilistic models are currently the most useful approach to representing the entire therapy outcome process.

  6. Experimenting `learn by doing' and `learn by failing'

    NASA Astrophysics Data System (ADS)

    Pozzi, Rossella; Noè, Carlo; Rossi, Tommaso

    2015-01-01

    According to the literature, in recent years, developing experiential learning has fulfilled the requirement of a deep understanding of lean philosophy by engineering students, demonstrating the advantages and disadvantages of some of the key principles of lean manufacturing. On the other hand, the literature evidences how some kinds of game-based experiential learning overlook daily difficulties, which play a central role in manufacturing systems. To fill the need of a game overcoming such lack of vision, an innovative game direct in-field, named Kart Factory, has been developed. Actual production shifts are simulated, while keeping all the elements peculiar to a real production set (i.e. complexity, effort, safety). The working environment is a real pedal car assembly department, the products to be assembled have relevant size and weight (i.e. up to 35 kg approximately), and the provided tools are real production equipment (e.g. keys, screwdrivers, trans-pallets, etc.). Due to the need to maximise the impact on students, a labour-intensive process characterises the production department. The whole training process is based on three educational principles: Experience Value Principle, Error Value Principle, and Team Value Principle. As the 'learn by doing' and 'learn by failing' are favoured, the theory follows the practice, while crating the willingness to 'do' instead of just designing or planning. The gathered data prove the Kart Factory's effectiveness in reaching a good knowledge of lean concepts, notwithstanding the students' initial knowledge level.

  7. Hemodynamic Conditions in a Failing Peripheral Artery Bypass Graft

    PubMed Central

    McGah, Patrick M.; Leotta, Daniel F.; Beach, Kirk W.; Zierler, R. Eugene; Riley, James J.; Aliseda, Alberto

    2012-01-01

    Objective The mechanisms of restenosis in autogenous vein bypass grafts placed for peripheral artery disease are not completely understood. We seek to investigate the role of hemodynamic stress in a case study of a revised bypass graft that failed due to restenosis. Methods The morphology of the lumen is reconstructed from a custom 3D ultrasound system. Scans were taken at one, six, and sixteen months after a patch angioplasty procedure. Computational hemodynamic simulations of the patient-specific model provide the blood flow features and the hemodynamic stresses on the vessel wall at the three time points studied. Results The vessel was initially free of any detectable lesions, but a 60% diameter reducing stenosis developed over the 16 month interval of study. As determined from the simulations, chaotic and recirculating flow occurred downstream of the stenosis due to the sudden widening of the lumen at the patch location. Curvature and a sudden increase in the lumen cross-sectional area induce these flow features that are hypothesized to be conducive to intimal hyperplasia. Favorable agreement was found between simulation results and in vivo Doppler ultrasound velocity measurements. Conclusions Transitional and chaotic flow occurs at the site of the revision, inducing a complex pattern of wall shear are computed with the hemodynamic simulations. This supports the hypothesis that the hemodynamic stresses in the revised segment, produced by the coupling of vessel geometry and chaotic flow, led to the intimal hyperplasia and restenosis of the graft. PMID:22551907

  8. Comparative surface microanalysis of failed Brånemark implants.

    PubMed

    Aparicio, C; Olivé, J

    1992-01-01

    The chemical composition and topography of an implant surface determine the human immunologic system response. This study compared the surfaces of 13 Brånemark oral implants, 11 that came from retrieved specimens which failed initially or did not osseointegrate and 2 that were never implanted (controls). The period of implantation in human jaws varied between 3 and 20 months. After cleaning and sterilization, the topography, surface chemical composition, and thickness of the oxide layer were studied. The results obtained with scanning electron microscopy did not show any significant topographic differences among the specimens. X-ray spectrographic microanalysis showed very similar composition (titanium and amounts less than 0.5% of other elements) in the outermost layer of the analyzed specimens. The Auger spectroscope revealed considerable percentage differences in the amount of carbon and silicon in the last monolayers, which could be attributed to handling or to an inadequate cleaning process. This places the retrieved specimens out of the acceptable statistical limits of contamination by introducing a factor of doubt for long-term prognosis in the hypothetical situation of their re-use. PMID:1398830

  9. Viewpoint: why the clinical ethics we teach fails patients.

    PubMed

    Fiester, Autumn

    2007-07-01

    The clinical ethics framework that is typically taught to medical students and residents is deeply flawed, and the result of using this framework exclusively to resolve ethical conflicts at the bedside is compromised patient care. The author calls this framework the principlist paradigm and maintains that it blinds clinicians from seeing the full set of moral obligations they have to the patient and limits the range of options they see as available to navigate through ethical conflicts. Although it is important for the moral obligations it does recognize (e.g., those based on the principles of autonomy, beneficence, nonmaleficence, and justice), the principlist paradigm should not be used as the only moral template for case analysis. The author illustrates the paradigm's limitations with a clinical case study, in which the treating clinicians failed to recognize three important moral obligations to the patient: the obligation to express regret, the obligation to apologize, and the obligation to make amends. The failure to recognize these widely accepted moral obligations can have tragic consequences. The principlist paradigm undertrains clinicians for the complex ethical dilemmas they face in practice, and medical ethics educators need to rethink the tools they offer student clinicians to guide their ethical analysis. The author advocates a reexamination of this standard approach to teaching clinical ethics.

  10. Salvage of failed protein targets by reductive alkylation.

    PubMed

    Tan, Kemin; Kim, Youngchang; Hatzos-Skintges, Catherine; Chang, Changsoo; Cuff, Marianne; Chhor, Gekleng; Osipiuk, Jerzy; Michalska, Karolina; Nocek, Boguslaw; An, Hao; Babnigg, Gyorgy; Bigelow, Lance; Joachimiak, Grazyna; Li, Hui; Mack, Jamey; Makowska-Grzyska, Magdalena; Maltseva, Natalia; Mulligan, Rory; Tesar, Christine; Zhou, Min; Joachimiak, Andrzej

    2014-01-01

    The growth of diffraction-quality single crystals is of primary importance in protein X-ray crystallography. Chemical modification of proteins can alter their surface properties and crystallization behavior. The Midwest Center for Structural Genomics (MCSG) has previously reported how reductive methylation of lysine residues in proteins can improve crystallization of unique proteins that initially failed to produce diffraction-quality crystals. Recently, this approach has been expanded to include ethylation and isopropylation in the MCSG protein crystallization pipeline. Applying standard methods, 180 unique proteins were alkylated and screened using standard crystallization procedures. Crystal structures of 12 new proteins were determined, including the first ethylated and the first isopropylated protein structures. In a few cases, the structures of native and methylated or ethylated states were obtained and the impact of reductive alkylation of lysine residues was assessed. Reductive methylation tends to be more efficient and produces the most alkylated protein structures. Structures of methylated proteins typically have higher resolution limits. A number of well-ordered alkylated lysine residues have been identified, which make both intermolecular and intramolecular contacts. The previous report is updated and complemented with the following new data; a description of a detailed alkylation protocol with results, structural features, and roles of alkylated lysine residues in protein crystals. These contribute to improved crystallization properties of some proteins. PMID:24590719

  11. BLACK HOLE FORMATION IN FAILING CORE-COLLAPSE SUPERNOVAE

    SciTech Connect

    O'Connor, Evan; Ott, Christian D. E-mail: cott@tapir.caltech.edu

    2011-04-01

    We present results of a systematic study of failing core-collapse supernovae and the formation of stellar-mass black holes (BHs). Using our open-source general-relativistic 1.5D code GR1D equipped with a three-species neutrino leakage/heating scheme and over 100 presupernova models, we study the effects of the choice of nuclear equation of state (EOS), zero-age main sequence (ZAMS) mass and metallicity, rotation, and mass-loss prescription on BH formation. We find that the outcome, for a given EOS, can be estimated, to first order, by a single parameter, the compactness of the stellar core at bounce. By comparing protoneutron star (PNS) structure at the onset of gravitational instability with solutions of the Tolman-Oppenheimer-Volkof equations, we find that thermal pressure support in the outer PNS core is responsible for raising the maximum PNS mass by up to 25% above the cold NS value. By artificially increasing neutrino heating, we find the critical neutrino heating efficiency required for exploding a given progenitor structure and connect these findings with ZAMS conditions, establishing, albeit approximately, for the first time based on actual collapse simulations, the mapping between ZAMS parameters and the outcome of core collapse. We also study the effect of progenitor rotation and find that the dimensionless spin of nascent BHs may be robustly limited below a* = Jc/GM{sup 2} = 1 by the appearance of nonaxisymmetric rotational instabilities.

  12. Failed Eradication for Helicobacter pylori. What Should Be Done?

    PubMed

    Mégraud, Francis

    2016-01-01

    Failed eradication of Helicobacter pylori occurs when the antibiotic concentration at the site where H. pylori is located is lower than the minimal inhibitory concentration of the antibiotic for this bacterium. The main reason for this is the acquisition of resistance; and in the context of the most common treatment, the main reason is the acquisition of resistance to clarithromycin. Several options can then be followed. The most rational option is to use a tailored therapy, that is, to look for clarithromycin resistance either by culture plus antibiogram or by a molecular method. The standard triple therapy is used only in the case of clarithromycin susceptibility. In case of resistance or if an empiric treatment must be given, a good option is to use a bismuth-based quadruple therapy. If unavailable, clarithromycin-based quadruple therapies can be used either as sequential or 'concomitant' or hybrid. The limit, especially for concomitant therapy, is the use of clarithromycin, which will be inactive in about 2/3 of the cases, adding to cost and adverse events. Recently, the dual therapy proton pump inhibitor-amoxicillin has been revisited especially in the Far East, and increasing the dose and the frequency of administration gives excellent results. PMID:27332826

  13. [Pregnancy proceeding to term following failed induced abortion].

    PubMed

    Doppenberg, H J; Mulder-Meiss, H B

    1986-06-21

    The 4th Pregnacy of a 30 year old woman proceeded to term following the failure of induced abortion via aspiration conducted during the 8th week. The woman feared possible damage to her unborn child once the failure of the abortion was determined. Only after careful counselling and emotional suport from both her personal physician, the clinic staff, and the midwife who supervised her home delivery was the woman able to decide to carry the pregnancy to term. Anxiety surfaced during the subsequent 6 months, even though the child was found to be healthy in all respects. Only through intsive psychosocial counseling was she able to regain self assurance and self control. A review by computer of the international literature revealed few documented cases of serious congenital malformations following failed abortions. Postdelivery psychosocial support structures for such women are particularly vital and require the sensitive intervention of trained personnel, including family physicians, as well as staff physicians of hospitals and family planning centers.

  14. Fail-fixed servovalve with positive fluid feedback

    NASA Technical Reports Server (NTRS)

    Kast, Howard B. (Inventor)

    1984-01-01

    The servovalve includes a primary jet of fluid. A variable control signal is adapted to vary the angular position of the primary jet from its maximum recovery position. A first fluid path is adapted to supply fluid to a servopiston at a variable pressure determined at least in part by the control signal. A second fluid path is adapted to receive a predetermined portion of the primary jet fluid when the control signal reaches a predetermined value. The second fluid path terminates in the vicinity of the primary jet and is adapted to direct a secondary jet of fluid at the primary jet to deflect the primary jet toward the input orifice of the second fluid path. The resultant positive fluid feedback in the second fluid path causes the primary jet to latch in a first angular position relative to the maximum recovery position when the control signal reaches a predetermined value. The servovalve may further include a means to discharge the fluid and a means to block the first fluid path to the servopiston when the control signal falls below a second predetermined value. A method of operating a fail-fixed servovalve is also described.

  15. Cluster Development Test 2: An Assessment of a Failed Test

    NASA Technical Reports Server (NTRS)

    Machin, Ricardo A.; Evans, Carol T.

    2009-01-01

    On 31 July 2008 the National Aeronautics and Space Administration Crew Exploration Vehicle Parachute Assembly System team conducted the final planned cluster test of the first generation parachute recovery system design. The two primary test objectives were to demonstrate the operation of the complete parachute system deployed from a full scale capsule simulator and to demonstrate the test technique of separating the capsule simulator from the Low Velocity Air Drop pallet used to extract the test article from a United States Air Force C-17 aircraft. The capsule simulator was the Parachute Test Vehicle with an accurate heat shield outer mold line and forward bay compartment of the Crew Exploration Vehicle Command Module. The Parachute Test Vehicle separated cleanly from the pallet following extraction, but failed to reach test conditions resulting in the failure of the test and the loss of the test assets. No personnel were injured. This paper will discuss the design of the test and the findings of the team that investigated the test, including a discussion of what were determined to be the root causes of the failure.

  16. NEUROMODULATION OF THE FAILING HEART: LOST IN TRANSLATION?

    PubMed Central

    Byku, Mirnela; Mann, Douglas L.

    2016-01-01

    SUMMARY Sympathovagal imbalance contributes to progressive worsening of HF (HF) and is associated with untoward clinical outcomes. Based on compelling pre-clinical studies which supported the role of autonomic modulation in HF models, a series of clinical studies were initiated using spinal cord stimulation (SCS), vagus nerve stimulation (VNS) and baroreceptor activation therapy (BAT) in patients with HF with a reduced ejection fraction (HFrEF). While the phase II studies with BAT remain encouraging, the larger clinical studies with SCS and VNS have yielded disappointing results. Here we will focus on the pre-clinical studies that supported the role of neuromodulation in the failing heart, as well provide a critical review of the recent clinical trials that have sought to modulate autonomic tone in HF patients. This review will conclude with an analysis of some of the difficulties in translating device-based modulation of the autonomic nervous from pre-clinical models into successful clinical trials, as well as provide suggestions for how to move the field of neuromodulation forward PMID:27525317

  17. Looking back at the future: why Hillarycare failed.

    PubMed

    Navarro, Vicente

    2008-01-01

    The current Democratic Party candidates for U.S. president, including Hillary Rodham Clinton, have committed themselves to establishing universal health care that will guarantee access to care in time of need, a basic human right still denied in the United States. This commitment is partly a response to the U.S. population's high levels of dissatisfaction (now at unprecedented levels) with the way health care is funded and organized. The article analyzes why a similar commitment by President Bill Clinton in 1992 failed, and challenges some of the main explanations for that failure put forward by protagonists of the White House health care reform task force (chaired by Hillary Clinton). The author emphasizes that the primary reason for the failure was the lack of political will to confront major players in medical care funding, especially the insurance companies and large employers. He postulates that unless such political will exists and unless the system of funding electoral campaigns undergoes major reform-reducing or eliminating the power of financial and economic lobbies in the political process-the United States will not have universal health care. It is a worrisome sign that these lobbies are financing the campaigns of many of today's presidential candidates.

  18. Management of failed rotator cuff repair: a systematic review

    PubMed Central

    Lädermann, Alexandre; Denard, Patrick J; Burkhart, Stephen S

    2016-01-01

    Importance Recurrent tear after rotator cuff repair (RCR) is common. Conservative, and open and arthroscopic revisions, have been advocated to treat these failures. Aim or objective The purpose of this systematic review was to evaluate the different options for managing recurrent rotator cuff tears. Evidence review A search was conducted of level I through 4 studies from January 2000 to October 2015, to identify studies reporting on failed RCR. 10 articles were identified. The overall quality of evidence was very low. Findings Mid-term to long-term follow-up of patients treated conservatively revealed acceptable results; a persistent defect is a well-tolerated condition that only occasionally requires subsequent surgery. Conservative treatment might be indicated in most patients, particularly in case of posterosuperior involvement and poor preoperative range of motion. Revision surgery might be indicated in a young patient with a repairable lesion, a 3 tendon tear, and in those with involvement of the subscapularis. Conclusions and relevance The current review indicates that arthroscopic revision RCR can lead to improvement in functional outcome despite a high retear rate. Further studies are needed to develop specific rehabilitation in the case of primary rotator cuff failure, to better understand the place of each treatment option, and, in case of repair, to optimise tendon healing. PMID:27134759

  19. Failed back surgery syndrome: review and new hypotheses

    PubMed Central

    Bordoni, Bruno; Marelli, Fabiola

    2016-01-01

    Failed back surgery syndrome (FBSS) is a term used to define an unsatisfactory outcome of a patient who underwent spinal surgery, irrespective of type or intervention area, with persistent pain in the lumbosacral region with or without it radiating to the leg. The possible reasons and risk factors that would lead to FBSS can be found in distinct phases: in problems already present in the patient before a surgical approach, such as spinal instability, during surgery (for example, from a mistake by the surgeon), or in the postintervention phase in relation to infections or biomechanical alterations. This article reviews the current literature on FBSS and tries to give a new hypothesis to understand the reasons for this clinical problem. The dysfunction of the diaphragm muscle is a component that is not taken into account when trying to understand the reasons for this syndrome, as there is no existing literature on the subject. The diaphragm is involved in chronic lower back and sacroiliac pain and plays an important role in the management of pain perception. PMID:26834497

  20. How to slow down light and where relativity theory fails

    NASA Astrophysics Data System (ADS)

    Zhang, Meggie

    2013-03-01

    Research found logical errors in mathematics and in physics. After discovered wave-particle duality made an assumption I reinterpreted quantum mechanic and I was able to find new information from existing publications and concluded that photon is not a fundamental particle which has a structure. These work has been presented at several APS meetings and EuNPC2012. During my research I also arrived at the exact same conclusion using Newton's theory of space-time, then found the assumptions that relativity theory made failed logical test and violated basic mathematical logic. And Minkowski space violated Newton's law of motion, Lorenz 4-dimensional transformation was mathematically incomplete. After modifying existing physics theories I designed an experiment to demonstrate where light can be slow down or stop for structural study. Such method were also turn into a continuous room temperature fusion method. However the discoveries involves large amount of complex logical analysis. Physicists are generally not philosophers, therefore to make the discovery fully understood by most physicists is very challenging. This work is supported by Dr. Kursh at Northeastern University.

  1. Requirements: Towards an understanding on why software projects fail

    NASA Astrophysics Data System (ADS)

    Hussain, Azham; Mkpojiogu, Emmanuel O. C.

    2016-08-01

    Requirement engineering is at the foundation of every successful software project. There are many reasons for software project failures; however, poorly engineered requirements process contributes immensely to the reason why software projects fail. Software project failure is usually costly and risky and could also be life threatening. Projects that undermine requirements engineering suffer or are likely to suffer from failures, challenges and other attending risks. The cost of project failures and overruns when estimated is very huge. Furthermore, software project failures or overruns pose a challenge in today's competitive market environment. It affects the company's image, goodwill, and revenue drive and decreases the perceived satisfaction of customers and clients. In this paper, requirements engineering was discussed. Its role in software projects success was elaborated. The place of software requirements process in relation to software project failure was explored and examined. Also, project success and failure factors were also discussed with emphasis placed on requirements factors as they play a major role in software projects' challenges, successes and failures. The paper relied on secondary data and empirical statistics to explore and examine factors responsible for the successes, challenges and failures of software projects in large, medium and small scaled software companies.

  2. Comparative surface microanalysis of failed Brånemark implants.

    PubMed

    Aparicio, C; Olivé, J

    1992-01-01

    The chemical composition and topography of an implant surface determine the human immunologic system response. This study compared the surfaces of 13 Brånemark oral implants, 11 that came from retrieved specimens which failed initially or did not osseointegrate and 2 that were never implanted (controls). The period of implantation in human jaws varied between 3 and 20 months. After cleaning and sterilization, the topography, surface chemical composition, and thickness of the oxide layer were studied. The results obtained with scanning electron microscopy did not show any significant topographic differences among the specimens. X-ray spectrographic microanalysis showed very similar composition (titanium and amounts less than 0.5% of other elements) in the outermost layer of the analyzed specimens. The Auger spectroscope revealed considerable percentage differences in the amount of carbon and silicon in the last monolayers, which could be attributed to handling or to an inadequate cleaning process. This places the retrieved specimens out of the acceptable statistical limits of contamination by introducing a factor of doubt for long-term prognosis in the hypothetical situation of their re-use.

  3. Looking back at the future: why Hillarycare failed.

    PubMed

    Navarro, Vicente

    2008-01-01

    The current Democratic Party candidates for U.S. president, including Hillary Rodham Clinton, have committed themselves to establishing universal health care that will guarantee access to care in time of need, a basic human right still denied in the United States. This commitment is partly a response to the U.S. population's high levels of dissatisfaction (now at unprecedented levels) with the way health care is funded and organized. The article analyzes why a similar commitment by President Bill Clinton in 1992 failed, and challenges some of the main explanations for that failure put forward by protagonists of the White House health care reform task force (chaired by Hillary Clinton). The author emphasizes that the primary reason for the failure was the lack of political will to confront major players in medical care funding, especially the insurance companies and large employers. He postulates that unless such political will exists and unless the system of funding electoral campaigns undergoes major reform-reducing or eliminating the power of financial and economic lobbies in the political process-the United States will not have universal health care. It is a worrisome sign that these lobbies are financing the campaigns of many of today's presidential candidates. PMID:18459278

  4. 45 CFR 264.76 - What action will we take if a State fails to remit funds after failing to meet its required...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false What action will we take if a State fails to remit funds after failing to meet its required Contingency Fund MOE level? 264.76 Section 264.76 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES,...

  5. Porous filtering media comparison through wet and dry sampling of fixed bed gasification products

    NASA Astrophysics Data System (ADS)

    Allesina, G.; Pedrazzi, S.; Montermini, L.; Giorgini, L.; Bortolani, G.; Tartarini, P.

    2014-11-01

    The syngas produced by fixed bed gasifiers contains high quantities of particulate and tars. This issue, together with its high temperature, avoids its direct exploitation without a proper cleaning and cooling process. In fact, when the syngas produced by gasification is used in an Internal Combustion engine (IC), the higher the content of tars and particulate, the higher the risk to damage the engine is. If these compounds are not properly removed, the engine may fail to run. A way to avoid engine fails is to intensify the maintenance schedule, but these stops will reduce the system profitability. From a clean syngas does not only follow higher performance of the generator, but also less pollutants in the atmosphere. When is not possible to work on the gasification reactions, the filter plays the most important role in the engine safeguard process. This work is aimed at developing and comparing different porous filters for biomass gasifiers power plants. A drum filter was developed and tested filling it with different filtering media available on the market. As a starting point, the filter was implemented in a Power Pallet 10 kW gasifier produced by the California-based company "ALL Power Labs". The original filter was replaced with different porous biomasses, such as woodchips and corn cobs. Finally, a synthetic zeolites medium was tested and compared with the biological media previously used. The Tar Sampling Protocol (TSP) and a modified "dry" method using the Silica Gel material were applied to evaluate the tars, particulate and water amount in the syngas after the filtration process. Advantages and disadvantages of every filtering media chosen were reported and discussed.

  6. Optimum constrained image restoration filters

    NASA Technical Reports Server (NTRS)

    Riemer, T. E.; Mcgillem, C. D.

    1974-01-01

    The filter was developed in Hilbert space by minimizing the radius of gyration of the overall or composite system point-spread function subject to constraints on the radius of gyration of the restoration filter point-spread function, the total noise power in the restored image, and the shape of the composite system frequency spectrum. An iterative technique is introduced which alters the shape of the optimum composite system point-spread function, producing a suboptimal restoration filter which suppresses undesirable secondary oscillations. Finally this technique is applied to multispectral scanner data obtained from the Earth Resources Technology Satellite to provide resolution enhancement. An experimental approach to the problems involving estimation of the effective scanner aperture and matching the ERTS data to available restoration functions is presented.

  7. Spam Filtering without Text Analysis

    NASA Astrophysics Data System (ADS)

    Belabbes, Sihem; Richard, Gilles

    Our paper introduces a new way to filter spam using as background the Kolmogorov complexity theory and as learning component a Support Vector Machine. Our idea is to skip the classical text analysis in use with standard filtering techniques, and to focus on the measure of the informative content of a message to classify it as spam or legitimate. Exploiting the fact that we can estimate a message information content through compression techniques, we represent an e-mail as a multi-dimensional real vector and we train a Support Vector Machine to get a classifier achieving accuracy rates in the range of 90%-97%, bringing our combined technique at the top of the current spam filtering technologies.

  8. Gradient Domain Guided Image Filtering.

    PubMed

    Kou, Fei; Chen, Weihai; Wen, Changyun; Li, Zhengguo

    2015-11-01

    Guided image filter (GIF) is a well-known local filter for its edge-preserving property and low computational complexity. Unfortunately, the GIF may suffer from halo artifacts, because the local linear model used in the GIF cannot represent the image well near some edges. In this paper, a gradient domain GIF is proposed by incorporating an explicit first-order edge-aware constraint. The edge-aware constraint makes edges be preserved better. To illustrate the efficiency of the proposed filter, the proposed gradient domain GIF is applied for single-image detail enhancement, tone mapping of high dynamic range images and image saliency detection. Both theoretical analysis and experimental results prove that the proposed gradient domain GIF can produce better resultant images, especially near the edges, where halos appear in the original GIF. PMID:26285153

  9. Design of wind shear filters

    NASA Technical Reports Server (NTRS)

    Joerck, H.

    1984-01-01

    A number of aircraft accidents are caused by the effects of wind shear. In connection with efforts to eliminate or reduce hazards leading to such accidents, the possibility was considered to improve aircraft control systems. However, the effective implementation of the considered approaches will only be possible if suitable filters can be designed for a separation of gusts, which involve higher frequencies from low-frequency wind shear components. Filters of appropriate design should be suited for an employment in connection with all flight conditions. Feasible approaches for obtaining such filters are discussed. A survey is provided regarding the order of magnitude of the improvements which can be achieved, taking into account the performance characteristics of the A300 controller.

  10. Anaerobic filter for biogas production

    NASA Astrophysics Data System (ADS)

    Chavadej, S.

    1980-01-01

    A laboratory study evaluated the performance of an anaerobic filter in producing biogas from pig waste with 30,000 mg/l of COD. The filter packing was bamboo rings of 1 and 1/2 in. diameter, 1 in. long; the bamboo-bed filter operated satisfactorily in a wide COD loading range of 3.74-15.65 kg/cu m/d which corresponds to the hydraulic retention of 8.47 to 1.68 days. At the optimum loading of 7.299 kg COD/cu m/d, the largest gas rate of 0.212 cu m/kg of COD was produced. The required volume of the digester for 1.2 cu m/d of gas production would be only 1.5 cu m; in practical applications, consideration should be given to the gas collecting system and clogging problems.

  11. Radiant zone heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  12. Westinghouse advanced particle filter system

    SciTech Connect

    Lippert, T.E.; Bruck, G.J.; Sanjana, Z.N.; Newby, R.A.

    1994-10-01

    Integrated Gasification Combined Cycles (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) are being developed and demonstrated for commercial, power generation application. Hot gas particulate filters are key components for the successful implementation of IGCC and PFBC in power generation gas turbine cycles. The objective of this work is to develop and qualify through analysis and testing a practical hot gas ceramic barrier filter system that meets the performance and operational requirements of PFBC and IGCC systems. This paper updates the assessment of the Westinghouse hot gas filter design based on ongoing testing and analysis. Results are summarized from recent computational fluid dynamics modeling of the plenum flow during back pulse, analysis of candle stressing under cleaning and process transient conditions and testing and analysis to evaluate potential flow induced candle vibration.

  13. Integrated Geophysical and Geotechnical Investigation of the Failed Portion of a Road in Basement Complex Terrain, Southwest Nigeria.

    NASA Astrophysics Data System (ADS)

    Osinowo, O. O.; Oladunjoye, M. A.; Olayinka, A. I.

    2008-05-01

    Several efforts by the local authority to fix the bad portion of the Ijebu Ode - Erunwon road, southwest Nigeria have over the years yielded no meaningful result as the road often gets deteriorated shortly after repair. Motorists and other road users have abandoned this road that is meant to link a commercial center with several farming communities, thus making the cost of transportation of farm produce very high. Geophysical methods of investigation integrated with geotechnical studies of the road, especially the failed portion were undertaken with the object of finding causes of the road failure as well as determine the most appropriate design method. Very Low Frequency Electromagnetic (VLF-EM) and electrical resistivity methods were employed to determine sections of the road with anomalous electrical responses that could be interpreted in terms of structures, lithology, water saturation etc. Geotechnical studies such as California Bearing ratio (CBR), grain size analysis, liquid limit, linear shrinkage, plastic limit, etc of samples obtained from sections identified as having high electrical anomaly were also carried out to determine geotechnical properties. Plots of inverted VLF-EM real and filtered real data identified bad sections of the road show peaks with positive filtered real amplitudes greater than 30% and lower amplitudes less than 30% and were interpreted to indicate major and minor linear features of faults and fractured zones, which in addition also display very high conductivity values. Vertical Electrical Soundings (VES) probe of the failed portions gave three to four layered earth interpreted to contain clayey-sand and loose saturated sand units at the upper portion, highly saturated weathered/fractured basement and fresh basement at the lower portion. Soaked and unsoaked CBR result range from 70.3 - 83.9%, and 12.9 - 31.6% respectively, indicating percentage reduction in strength with wetness of 55.7% - 83.8%. Liquid limit, linear shrinkage and

  14. ATTITUDE FILTERING ON SO(3)

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis

    2005-01-01

    A new method is presented for the simultaneous estimation of the attitude of a spacecraft and an N-vector of bias parameters. This method uses a probability distribution function defined on the Cartesian product of SO(3), the group of rotation matrices, and the Euclidean space W N .The Fokker-Planck equation propagates the probability distribution function between measurements, and Bayes s formula incorporates measurement update information. This approach avoids all the issues of singular attitude representations or singular covariance matrices encountered in extended Kalman filters. In addition, the filter has a consistent initialization for a completely unknown initial attitude, owing to the fact that SO(3) is a compact space.

  15. Tunable-Bandwidth Filter System

    NASA Technical Reports Server (NTRS)

    Aye, Tin; Yu, Kevin; Dimov, Fedor; Savant, Gajendra

    2006-01-01

    A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote-sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS was shown to be capable of spectral sampling of images in the visible range over a 200-nm spectral range with a spectral resolution of .30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of the lenses are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses

  16. Tunable-Bandwidth Filter System

    NASA Technical Reports Server (NTRS)

    Bailey, John W.

    2004-01-01

    A tunable-bandwidth filter system (TBFS), now undergoing development, is intended to be part of a remote sensing multispectral imaging system that will operate in the visible and near infrared spectral region (wavelengths from 400 to 900 nm). Attributes of the TBFS include rapid tunability of the pass band over a wide wavelength range and high transmission efficiency. The TBFS is based on a unique integration of two pairs of broadband Raman reflection holographic filters with two rotating spherical lenses. In experiments, a prototype of the TBFS, was shown to be capable of spectral sampling of images in the visible range over a 200 nm spectral range with a spectral resolution of 30 nm. The figure depicts the optical layout of a prototype of the TBFS as part of a laboratory multispectral imaging system for the spectral sampling of color test images in two orthogonal polarizations. Each pair of broadband Raman reflection holographic filters is mounted at an equatorial plane between two halves of a spherical lens. The two filters in each pair are characterized by steep spectral slopes (equivalently, narrow spectral edges), no ripple or side lobes in their pass bands, and a few nanometers of non-overlapping wavelength range between their pass bands. Each spherical lens and thus the filter pair within it is rotated in order to rapidly tune its pass band. The rotations of are effected by electronically controlled, programmable, high-precision rotation stages. The rotations are coordinated by electronic circuits operating under overall supervision of a personal computer in order to obtain the desired variation of the overall pass bands with time. Embedding the filters inside the spherical lenses increases the range of the hologram incidence angles, making it possible to continuously tune the pass and stop bands of the filters over a wider wavelength range. In addition, each spherical lens also serves as part of the imaging optics: The telephoto lens focuses incoming light

  17. Machine-learning-assisted materials discovery using failed experiments.

    PubMed

    Raccuglia, Paul; Elbert, Katherine C; Adler, Philip D F; Falk, Casey; Wenny, Malia B; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A; Schrier, Joshua; Norquist, Alexander J

    2016-05-01

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on 'dark' reactions--failed or unsuccessful hydrothermal syntheses--collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted conditions

  18. Measuring mental disorders: The failed commensuration project of DSM-5.

    PubMed

    Whooley, Owen

    2016-10-01

    Commensuration - the comparison of entities according to a common quantitative metric - is a key process in efforts to rationalize medicine. The push toward evidence-based medicine and quantitative assessment has led to the proliferation of metrics in healthcare. While social scientific attention has revealed the effects of these metrics once institutionalized - on clinical practice, on medical expertise, on outcome assessment, on valuations of medical services, and on experiences of illness - less attention has been paid to the process of developing metrics. This article examines the attempt to create severity scales during the revision to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a case of failed commensuration. Using data from interviews with participants in the DSM-5 revision (n = 30), I reconstruct the problems that emerged in the DSM-5 Task Force's effort to develop viable psychometric instruments to measure severity. Framed as a part of a "paradigm shift" in psychiatry, the revision produced ad hoc, heterogeneous severity scales with divergent logics. I focus on two significant issues of metric construction in this case - diagnostic validity and clinical utility. Typically perceived as technical and conceptual challenges of design, I show how these issues were infused with, and undermined by, professional political dynamics, specifically tensions between medical researchers and clinicians. This case reveals that, despite its association with objectivity and transparency, commensuration encompasses more than identifying, operationalizing, and measuring an entity; it demands the negotiation of extra-scientific, non-empirical concerns that get written into medical metrics themselves. PMID:27526260

  19. Machine-learning-assisted materials discovery using failed experiments.

    PubMed

    Raccuglia, Paul; Elbert, Katherine C; Adler, Philip D F; Falk, Casey; Wenny, Malia B; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A; Schrier, Joshua; Norquist, Alexander J

    2016-05-01

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on 'dark' reactions--failed or unsuccessful hydrothermal syntheses--collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted conditions

  20. Forces in Erupting Flux Ropes: CMEs and Failed Eruptions

    NASA Astrophysics Data System (ADS)

    Chen, James

    2016-05-01

    A range of dynamical behaviors that can be exhibited by a quasi-statically evolving flux rope is studied. Starting with a CME-like flux rope in equilibrium balanced by the ambient coronal pressure (non-force-free) and an overlying coronal magnetic field (Bc), the poloidal flux is slowly increased, on a timescale much longer than the eruptive timescale of several to tens of minutes. In this configuration, the overlying field Bc provides an external downward restraining force, constituting an effective potential barrier. Slowly increasing poloidal flux causes the flux rope to gradually rise, following a sequence of quasi-static equilibria. As the apex of the flux rope rises past a critical height Z*, slightly higher than the peak of the potential barrier Bc(Z), it expands on a faster, dynamical (Alfvenic) timescale determined by the magnetic field and geometry of the flux rope. The expanding flux rope may reach a new equilibrium at height Z1. Observationally, this behavior would be recognized as a ``failed eruption.'' The new equilibrium flux rope is established if the magnetic tension force due to the toroidal magnetic field component Bt can balance the outward hoop force due to the poloidal component Bp. The flux rope may also expand without reaching a new equilibrium, provided a sufficiennt amount of poloidal flux is injected on a dynamical timescale so that the tension force cannot balance the hoop force. This scenario would result in a CME eruption. The influence of the poloidal flux injection, the Bc(Z) profile, and boundary conditions on the quantitative balance of the forces in an expanding flux rope is elucidated. Potentially observable consequences of the difference scenarios/models are discussed.Work supported by the Naval Research Laboratory Base Research Program

  1. Management of Failing Prosthetic Bypass Grafts with Metallic Stent Placement

    SciTech Connect

    Siskin, Gary P.; Stainken, Brian F.; Mandell, Valerie S.; Darling, R. Clement; Dowling, Kyran; Herr, Allen

    1999-09-15

    Purpose: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. Methods: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n= 3), rest pain (n= 9), and minor or major tissue loss (n= 3). Lesions were at the proximal anastomosis (n= 6), the distal anastomosis (n= 3), or within the graft (n= 6). Results: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. Conclusion: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.

  2. Machine-learning-assisted materials discovery using failed experiments

    NASA Astrophysics Data System (ADS)

    Raccuglia, Paul; Elbert, Katherine C.; Adler, Philip D. F.; Falk, Casey; Wenny, Malia B.; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A.; Schrier, Joshua; Norquist, Alexander J.

    2016-05-01

    Inorganic–organic hybrid materials such as organically templated metal oxides, metal–organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure–property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on ‘dark’ reactions—failed or unsuccessful hydrothermal syntheses—collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully

  3. Measuring mental disorders: The failed commensuration project of DSM-5.

    PubMed

    Whooley, Owen

    2016-10-01

    Commensuration - the comparison of entities according to a common quantitative metric - is a key process in efforts to rationalize medicine. The push toward evidence-based medicine and quantitative assessment has led to the proliferation of metrics in healthcare. While social scientific attention has revealed the effects of these metrics once institutionalized - on clinical practice, on medical expertise, on outcome assessment, on valuations of medical services, and on experiences of illness - less attention has been paid to the process of developing metrics. This article examines the attempt to create severity scales during the revision to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a case of failed commensuration. Using data from interviews with participants in the DSM-5 revision (n = 30), I reconstruct the problems that emerged in the DSM-5 Task Force's effort to develop viable psychometric instruments to measure severity. Framed as a part of a "paradigm shift" in psychiatry, the revision produced ad hoc, heterogeneous severity scales with divergent logics. I focus on two significant issues of metric construction in this case - diagnostic validity and clinical utility. Typically perceived as technical and conceptual challenges of design, I show how these issues were infused with, and undermined by, professional political dynamics, specifically tensions between medical researchers and clinicians. This case reveals that, despite its association with objectivity and transparency, commensuration encompasses more than identifying, operationalizing, and measuring an entity; it demands the negotiation of extra-scientific, non-empirical concerns that get written into medical metrics themselves.

  4. Machine-learning-assisted materials discovery using failed experiments

    NASA Astrophysics Data System (ADS)

    Raccuglia, Paul; Elbert, Katherine C.; Adler, Philip D. F.; Falk, Casey; Wenny, Malia B.; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A.; Schrier, Joshua; Norquist, Alexander J.

    2016-05-01

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on ‘dark’ reactions—failed or unsuccessful hydrothermal syntheses—collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted

  5. Failed eruptions of two intertwining small-scale filaments

    NASA Astrophysics Data System (ADS)

    Xue, Zhike; Yan, Xiaoli; Zhao, Li; Xiang, Yongyuan; Yang, Liheng; Guo, Yang

    2016-02-01

    Using multi-wavelength observations of the New Vacuum Solar Telescope (NVST), the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO), we study the topology and evolutions of two filaments observed in NOAA active region (AR) 12031 on 2014 April 7. Before their eruptions, the two filaments (F1 and F2) were sinistral filaments, and the left part of F1 (LP) was located above F2, the right part of F1 (RP) under F2. They show an overall intertwining structure. LP erupted first and rotated clockwise. The total rotation angle was about 470° (≈2.61π). With its rotation, most of the plasma fell back, and thus it was a failed eruption. Meanwhile, when LP erupted to a higher altitude, the overlying magnetic loops were partially pushed from the northeast to the southwest with projected speeds from 36 to 105 km s-1. Next, F2 began to erupt and, when reaching a certain height, the plasma of F2 started to fall down to their footpoints. Using the potential-field source-surface (PFSS) model, the decay indexes at five positions along the polarity inversion line of AR 12031 were calculated to be from 1.03 to 1.25 with an average value of 1.20 that was lower than the critical value for torus instability. These results imply that the kink instability was the main triggering mechanism for the eruption of F1, and the eruption of F2 was due to the decreasing of overlying magnetic loops caused by the eruption of F1. The eruptions of two filaments were confined by the large-scale overlying magnetic loops.

  6. Prognostic indicators for failed nonsurgical reduction of intussusception

    PubMed Central

    Khorana, Jiraporn; Singhavejsakul, Jesda; Ukarapol, Nuthapong; Laohapensang, Mongkol; Siriwongmongkol, Jakraphan; Patumanond, Jayanton

    2016-01-01

    Purpose To identify the risk factors for failure of nonsurgical reduction of intussusception. Methods Data from intussusception patients who were treated with nonsurgical reduction in Chiang Mai University Hospital and Siriraj Hospital between January 2006 and December 2012 were collected. Patients aged 0–15 years and without contraindications (peritonitis, abdominal X-ray signs of perforation, and/or hemodynamic instability) were included for nonsurgical reduction. The success and failure groups were divided according to the results of the reduction. Prognostic indicators for failed reduction were identified by using generalized linear model for exponential risk regression. The risk ratio (RR) was used to report each factor. Results One hundred and ninety cases of intussusception were enrolled. Twenty cases were excluded due to contraindications. A total of 170 cases of intussusception were included for the final analysis. The significant risk factors for reduction failure clustered by an age of 3 years were weight <12 kg (RR =1.48, P=0.004), symptom duration >3 days (RR =1.26, P<0.001), vomiting (RR =1.63, P<0.001), rectal bleeding (RR =1.50, P<0.001), abdominal distension (RR =1.60, P=0.003), temperature >37.8°C (RR =1.51, P<0.001), palpable abdominal mass (RR =1.26, P<0.001), location of mass (left over right side) (RR =1.48, P<0.001), poor prognostic signs on ultrasound scans (RR =1.35, P<0.001), and method of reduction (hydrostatic over pneumatic) (RR =1.34, P=0.023). The prediction ability of this model was 82.21% as assessed from the area under the receiver operating characteristic curve. Conclusion The identified prognostic factors for the nonsurgical reduction failure may help to predict the reduction outcome and provide information to the parents. PMID:27563245

  7. In Situ Cleanable Alternative HEPA Filter Media

    SciTech Connect

    Adamson, D. J.; Terry, M. T.

    2002-02-28

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of

  8. Vapor purification with self-cleaning filter

    DOEpatents

    Josephson, Gary B.; Heath, William O.; Aardahl, Christopher L.

    2003-12-09

    A vapor filtration device including a first electrode, a second electrode, and a filter between the first and second electrodes is disclosed. The filter is formed of dielectric material and the device is operated by applying a first electric potential between the electrodes to polarize the dielectric material such that upon passing a vapor stream through the filter, particles from the vapor stream are deposited onto the filter. After depositing the particles a second higher voltage is applied between the electrodes to form a nonthermal plasma around the filter to vaporize the collected particles thereby cleaning the filter. The filter can be a packed bed or serpentine filter mat, and an optional upstream corona wire can be utilized to charge airborne particles prior to their deposition on the filter.

  9. Stripe filters on multispectral linear arrays

    NASA Technical Reports Server (NTRS)

    Hall, J. H.; Blaha, F. C.; Frias, B. R.; Halvis, J.; Hubbard, E.

    1982-01-01

    Dielectric interference filters deposited directly on top of existing 200 element charge coupled device linear imaging arrays were designed, fabricated and evaluated. The optical performance of the filters was verified with regard to crosstalk between adjacent detector elements. The filters showed an average in-band transmittance greater than 80% and a total out of band transmittance of less than 5%. Filter stability was adequate for operation in a space environment. The filter elements were definable in 12 to 25 micron element size compatible with existing silicon detectors. These type of measurement were made: (1) spectral transmission of the filter as deposited on witness plates; (2) spectral response of the silicon sensing device; (3) any optical interaction between filter and sensing device; (4) the response of the filter/sensor combination; and (5) repeatability and uniformity of filter characteristics. Detailed discussion of these evaluations are given.

  10. Hot gas cross flow filtering module

    DOEpatents

    Lippert, Thomas E.; Ciliberti, David F.

    1988-01-01

    A filter module for use in filtering particulates from a high temperature gas has a central gas duct and at least one horizontally extending support mount affixed to the duct. The support mount supports a filter element thereon and has a chamber therein, which communicates with an inner space of the duct through an opening in the wall of the duct, and which communicates with the clean gas face of the filter element. The filter element is secured to the support mount over an opening in the top wall of the support mount, with releasable securement provided to enable replacement of the filter element when desired. Ceramic springs may be used in connection with the filter module either to secure a filter element to a support mount or to prevent delamination of the filter element during blowback.

  11. Measurements of filter-cake properties

    SciTech Connect

    Smith, D.H.; Grimm, U.; Haddad, G.J.

    1996-12-31

    The Pressurized Fluidized-Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) programs of the U.S. Department of Energy require filtration, at temperatures from about 600 to 900 {degrees}C, of fine particles of coal ash, char, or spent and unreacted sorbent from hot-gas streams. Achieving acceptable filter lifetimes requires solutions to or avoidance of, such problems as incomplete filter cleaning, re-entrainment (i.e., re-filtration) of particles from filter cleaning, and bridging of filter cake between adjacent filters. These and other potential problems may arise from the materials properties of filter cakes, from the filter-bank design, and from the mechanisms of filter cleaning. Avoiding re-entrainment requires that some bonding and agglomeration of particles occur in the cakes (so that the agglomerates from filter cleaning are too large to be re-entrained), but excessive agglomeration can produce poor cleaning or bridging. For both PFBC and IGCC applications, we can form filter cakes at process temperatures, gas compositions, and gas flow rates, and measure the gas-phase permeabilities, porosities, tensile strengths, and deformation coefficients of these filter cakes to determine their dependencies on temperature, reaction time, gas composition, particle compositions, and particle size distributions. Filter-cake shear strengths and flow factors can be measured for powders ``as received,`` for filter cakes that we have heated to process temperatures, or for powders heated in reactive gases to simulate gas-solid reactions in process filter cakes.

  12. The development of a porous silicon nitride crossflow filter; Final report, September 1988--September 1992

    SciTech Connect

    1992-09-01

    This report summarizes the work performed in developing a permeable form of silicon nitride for application to ceramic crossflow filters for use in advanced coal-fired electric power plants. The program was sponsored by the Department of Energy Morgantown Energy Technology Center and consisted of a design analysis and material development phase and a filter manufacture and demonstration phase. The crossflow filter design and operating requirements were defined. A filter design meeting the requirements was developed and thermal and stress analyses were performed. Material development efforts focused initially on reaction-bonded silicon nitride material. This approach was not successful, and the materials effort was refocused on the development of a permeable form of sintered silicon nitride (SSN). This effort was successful. The SSN material was used for the second phase of the program, filter manufacture and evaluation. Four half-scale SAN filter modules were fabricated. Three of the modules were qualified for filter performance tests. Tests were performed on two of the three qualified modules in the High-Temperature, High-Pressure facility at the Westinghouse Science and Technology Center. The first module failed on test when it expanded into the clamping device, causing dust leakage through the filter. The second module performed well for a cumulative 150-hr test. It displayed excellent filtration capability during the test. The blowback pulse cleaning was highly effective, and the module apparently withstood the stresses induced by the periodic pulse cleaning. Testing of the module resumed, and when the flow of combustion gas through the filter was doubled, cracks developed and the test was concluded.

  13. Electrostatic respirator filter media: filter efficiency and most penetrating particle size effects.

    PubMed

    Martin, S B; Moyer, E S

    2000-08-01

    New electrostatic filter media has been developed for use in 42 CFR 84 negative pressure particulate respirator filters. This respirator filter media was not available for evaluation prior to the change from 30 CFR 11 to 42 CFR 84. Thus, characterization of this filter media is warranted. In this study, the new 42 CFR 84 electrostatic respirator filters were investigated with respect to filter penetration and most penetrating particle size. Three different models of N95 filters, along with one model each of the N99, R95, and P100 class filters were used in this study. First, three of each filter were loaded with a sodium chloride (NaCl) aerosol, and three of each filter were loaded with a dioctyl phthalate (DOP) aerosol to obtain normal background penetration results for each filter. Then, two new filters of each type were dipped in isopropanol for 15 seconds and allowed to dry. This isopropanol dip should reduce or eliminate any electrostatic charge on the fibers of each filter, as reported in the technical literature. These dipped filters, along with controls of each filter type, were tested on a TSI 8160 filter tester to determine the most penetrating particle size. These same filters were then tested against a NaCl aerosol to get final penetration values. Electret filters rely heavily on their electrostatic charge to provide adequate filter efficiencies, and correlations between penetration and a filter's electrostatic characteristics are found in the technical literature. In all six of the filter models tested, filter penetration values increased considerably and the most penetrating particle size noticeably shifted toward larger particles. These results are important in better understanding how these new filter materials perform under various conditions, and they indicate the need for additional research to define environmental conditions that may affect electrostatic filter efficiency. PMID:10957816

  14. Automated Filtering of Internet Postings.

    ERIC Educational Resources Information Center

    Rosenfeld, Louis B.; Holland, Maurita P.

    1994-01-01

    Discussion of the use of dynamic data resources, such as Internet LISTSERVs or Usenet newsgroups, focuses on an experiment using an automated filtering system with Usenet newsgroups. Highlights include user satisfaction, based on retrieval size, data sources, and user interface and the need for some human mediation. (Contains two references.) (LRW)

  15. Bacteria/virus filter membrane

    NASA Technical Reports Server (NTRS)

    Lysaght, M. S.; Goodwin, F.; Roebelen, G.

    1977-01-01

    Hollow acrylate fiber membrane that filters bacterial and viral organisms can be used with closed-cycle life-support systems for underwater habitations or laboratories. Membrane also has applications in fields of medicine, gnotobiotics, pharmaceutical production, and industries and research facilities that require sterile water. Device eliminates need for strong chemicals or sterilizing agents, thereby reducing costs.

  16. Compact bypass-flow filter

    NASA Technical Reports Server (NTRS)

    Swift, W. G.; Ulanovsky, J. M.

    1979-01-01

    Annular filter consisting of stacked rings separates particulates from bypass fluid passing through it in radial direction without slowing down main flow across unimpeded flow of fluid through its center. Applications include fluidized bed reactors, equipment for catalyst operations, and water purification.

  17. Optical Correlator Performs Novelty Filtering

    NASA Technical Reports Server (NTRS)

    Liu, Duncan Tsuen-Hsi; Chao, Tien-Hsin; Cheng, Li-Jen

    1994-01-01

    Experimental real-time optical correlator performs correlation and novelty filtering in photorefractive crystal. Crystal oriented enabling cross-polarization diffraction: together with polarizing beam splitter, increases signal-to-noise ratio. Laser and optical components expand, collimate, and divide laser beam.

  18. ADVANCED HOT GAS FILTER DEVELOPMENT

    SciTech Connect

    RICHARD A. WAGNER

    1998-09-04

    This report describes the fabrication and testing of continuous fiber ceramic composite (CFCC) based hot gas filters. The fabrication approach utilized a modified filament winding method that combined both continuous and chopped fibers into a novel microstructure. The work was divided into five primary tasks. In the first task, a preliminary set of compositions was fabricated in the form of open end tubes and characterized. The results of this task were used to identify the most promising compositions for sub-scale filter element fabrication and testing. In addition to laboratory measurements of permeability and strength, exposure testing in a coal combustion environment was performed to asses the thermo-chemical stability of the CFCC materials. Four candidate compositions were fabricated into sub-scale filter elements with integral flange and a closed end. Following the 250 hour exposure test in a circulating fluid bed combustor, the retained strength ranged from 70 t 145 percent of the as-fabricated strength. The post-test samples exhibited non-catastrophic failure behavior in contrast to the brittle failure exhibited by monolithic materials. Filter fabrication development continued in a filter improvement and cost reduction task that resulted in an improved fiber architecture, the production of a net shape flange, and an improved low cost bond. These modifications were incorporated into the process and used to fabricate 50 full-sized filter elements for testing in demonstration facilities in Karhula, Finland and at the Power Systems Development Facility (PSDF) in Wilsonville, AL. After 581 hours of testing in the Karhula facility, the elements retained approximately 87 percent of their as-fabricated strength. In addition, mechanical response testing at Virginia Tech provided a further demonstration of the high level of strain tolerance of the vacuum wound filter elements. Additional testing in the M. W. Kellogg unit at the PSDF has accumulated over 1800 hours of

  19. Electric filter with movable belt electrode

    DOEpatents

    Bergman, W.

    1983-09-20

    A method and apparatus for removing airborne contaminants entrained in a gas or airstream includes an electric filter characterized by a movable endless belt electrode, a grounded electrode, and a filter medium sandwiched there between. Inclusion of the movable, endless belt electrode provides the driving force for advancing the filter medium through the filter, and reduces frictional drag on the filter medium, thereby permitting a wide choice of filter medium materials. Additionally, the belt electrode includes a plurality of pleats in order to provide maximum surface area on which to collect airborne contaminants. 4 figs.

  20. Flight prototype regenerative particulate filter system development

    NASA Technical Reports Server (NTRS)

    Green, D. C.; Garber, P. J.

    1974-01-01

    The effort to design, fabricate, and test a flight prototype Filter Regeneration Unit used to regenerate (clean) fluid particulate filter elements is reported. The design of the filter regeneration unit and the results of tests performed in both one-gravity and zero-gravity are discussed. The filter regeneration unit uses a backflush/jet impingement method of regenerating fluid filter elements that is highly efficient. A vortex particle separator and particle trap were designed for zero-gravity use, and the zero-gravity test results are discussed. The filter regeneration unit was designed for both inflight maintenance and ground refurbishment use on space shuttle and future space missions.