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Sample records for circumferential endocardial extent

  1. Assessment of circumferential endocardial extent of myocardial edema and infarction in patients with reperfused acute myocardial infarction: a cardiovascular magnetic resonance study.

    Science.gov (United States)

    Ota, Shingo; Tanimoto, Takashi; Hirata, Kumiko; Orii, Makoto; Shiono, Yasutsugu; Shimamura, Kunihiro; Ishibashi, Kohei; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Imanishi, Toshio; Akasaka, Takashi

    2014-01-01

    T2 weighted (T2W) images on cardiovascular magnetic resonance (CMR) visualizes myocardial edema, which reflects the myocardial area at risk (AAR) in reperfused acute myocardial infarction (AMI). Late gadolinium enhancement (LGE) demonstrates myocardial infarction. LGE images cover the whole left ventricle, but T2W images are obtained from a few slices of the left ventricle due to the long sequence time, so the quantification of AAR of the entire left ventricle is difficult. We hypothesize that we can quantify AAR with only LGE images if there is a strong correlation between the circumferential endocardial extent of myocardial edema and infarction. Thirty patients with first AMI were enrolled. All patients underwent successfully reperfusion therapy and CMR was performed within the first week after the event. We measured the circumferential extent of edema and infarction on short-axis views (T2 angle and LGE angle), respectively. A total of 82 short-axis slices showed transmural edema on T2W images. Corresponding LGE images were analyzed for the circumferential extent of infarction. The median [interquartile range] of T2 angle and DE angle were 147° [116°-219°] and 134° [104°-200°] in patients with LAD culprit lesion, 91° [87°-101°] and 85° [80°-90°] in LCX, and 110° [94°-123°] and 104° [89°-118°] in RCA, respectively. T2 angle was well correlated with LGE angle (r = 0.99, P infarction in reperfused AMI. Thus, T2 weighted imaging can be skipped to quantify the amount of AAR.

  2. MR findings of endocardial fibroelastosis in children

    Energy Technology Data Exchange (ETDEWEB)

    Stranzinger, Enno; Hernandez, Ramiro J. [University of Michigan Health System, Section of Pediatric Radiology, Ann Arbor, MI (United States); Ensing, Gregory J. [University of Michigan Health System, Department of Pediatrics and Communicable Diseases, Pediatric Echocardiography Laboratory, Ann Arbor, MI (United States)

    2008-03-15

    Endocardial fibroelastosis (EFE) is characterized by a diffuse white fibrous tissue lining the endocardium. The diagnosis is difficult to establish because clinical symptoms and electrocardiographic findings are nonspecific. Surgical resection of EFE requires the establishment of the diagnosis and delineation of the extent of the fibrotic changes. To describe the use of MRI in the assessment of EFE in children. Three children after surgery for aortic stenosis who were suspected of having EFE were evaluated by echocardiography and MRI. The MR evaluation consisted of black-blood, triple IR, bright-blood, perfusion and myocardial delayed-enhancement sequences. EFE was confirmed at surgery in all patients. Echocardiograms demonstrated vigorous systolic function but substantial diastolic dysfunction of the left ventricle in all. Mild endocardial brightening of the anterior septum, anterior wall, or papillary muscles was present in two. No study was thought to be diagnostic of endocardial fibrosis. On MRI EFE manifested at the endocardial surface as a rim of hypointense signal in the perfusion sequences and as a rim of hyperintense signal in the myocardial delayed-enhancement sequences. The black-blood, triple IR, and bright-blood sequences were not diagnostic. The diagnosis of EFE is difficult to establish by echocardiography. MRI using perfusion and myocardial delayed enhancement can be useful in establishing the diagnosis. (orig.)

  3. File list: DNS.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.CDV.10.AllAg.Endocardial_cells hg19 DNase-seq Cardiovascular Endocardial cells ...http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.CDV.10.AllAg.Endocardial_cells.bed ...

  4. File list: Unc.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.50.AllAg.Endocardial_cells hg19 Unclassified Cardiovascular Endocardial cel...ls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.CDV.50.AllAg.Endocardial_cells.bed ...

  5. File list: His.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.20.AllAg.Endocardial_cells hg19 Histone Cardiovascular Endocardial cells ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.CDV.20.AllAg.Endocardial_cells.bed ...

  6. File list: Unc.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.05.AllAg.Endocardial_cells hg19 Unclassified Cardiovascular Endocardial cel...ls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.CDV.05.AllAg.Endocardial_cells.bed ...

  7. File list: DNS.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.CDV.05.AllAg.Endocardial_cells hg19 DNase-seq Cardiovascular Endocardial cells ...http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.CDV.05.AllAg.Endocardial_cells.bed ...

  8. File list: His.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.10.AllAg.Endocardial_cells hg19 Histone Cardiovascular Endocardial cells ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.CDV.10.AllAg.Endocardial_cells.bed ...

  9. File list: DNS.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.CDV.50.AllAg.Endocardial_cells hg19 DNase-seq Cardiovascular Endocardial cells ...http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.CDV.50.AllAg.Endocardial_cells.bed ...

  10. File list: His.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.05.AllAg.Endocardial_cells hg19 Histone Cardiovascular Endocardial cells ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.CDV.05.AllAg.Endocardial_cells.bed ...

  11. File list: DNS.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.CDV.20.AllAg.Endocardial_cells hg19 DNase-seq Cardiovascular Endocardial cells ...http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.CDV.20.AllAg.Endocardial_cells.bed ...

  12. File list: Unc.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.CDV.20.AllAg.Endocardial_cells hg19 Unclassified Cardiovascular Endocardial cel...ls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.CDV.20.AllAg.Endocardial_cells.bed ...

  13. File list: His.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.CDV.50.AllAg.Endocardial_cells hg19 Histone Cardiovascular Endocardial cells ht...tp://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.CDV.50.AllAg.Endocardial_cells.bed ...

  14. Quantitative assessment of regional left ventricular motion using endocardial landmarks

    NARCIS (Netherlands)

    C.J. Slager (Cornelis); T.E.H. Hooghoudt (Ton); P.W.J.C. Serruys (Patrick); J.C.H. Schuurbiers (Johan); J.H.C. Reiber (Johan); G.T. Meester (Geert); P.D. Verdouw (Pieter); P.G. Hugenholtz (Paul)

    1986-01-01

    textabstractIn this study the hypothesis is tested that the motion pattern of small anatomic landmarks, recognizable at the left ventricular endocardial border in the contrast angiocardiogram, reflects the motion of the endocardial wall. To verify this, minute metal markers were inserted in the endo

  15. Early endocardial morphogenesis requires Scl/Tal1.

    Directory of Open Access Journals (Sweden)

    Jeroen Bussmann

    2007-08-01

    Full Text Available The primitive heart tube is composed of an outer myocardial and an inner endocardial layer that will give rise to the cardiac valves and septa. Specification and differentiation of these two cell layers are among the earliest events in heart development, but the embryonic origins and genetic regulation of early endocardial development remain largely undefined. We have analyzed early endocardial development in the zebrafish using time-lapse confocal microscopy and show that the endocardium seems to originate from a region in the lateral plate mesoderm that will give rise to hematopoietic cells of the primitive myeloid lineage. Endocardial precursors appear to rapidly migrate to the site of heart tube formation, where they arrive prior to the bilateral myocardial primordia. Analysis of a newly discovered zebrafish Scl/Tal1 mutant showed an additional and previously undescribed role of this transcription factor during the development of the endocardium. In Scl/Tal1 mutant embryos, endocardial precursors are specified, but migration is severely defective and endocardial cells aggregate at the ventricular pole of the heart. We further show that the initial fusion of the bilateral myocardial precursor populations occurs independently of the endocardium and tal1 function. Our results suggest early separation of the two components of the primitive heart tube and imply Scl/Tal1 as an indispensable component of the molecular hierarchy that controls endocardium morphogenesis.

  16. Early endocardial morphogenesis requires Scl/Tal1.

    Science.gov (United States)

    Bussmann, Jeroen; Bakkers, Jeroen; Schulte-Merker, Stefan

    2007-08-01

    The primitive heart tube is composed of an outer myocardial and an inner endocardial layer that will give rise to the cardiac valves and septa. Specification and differentiation of these two cell layers are among the earliest events in heart development, but the embryonic origins and genetic regulation of early endocardial development remain largely undefined. We have analyzed early endocardial development in the zebrafish using time-lapse confocal microscopy and show that the endocardium seems to originate from a region in the lateral plate mesoderm that will give rise to hematopoietic cells of the primitive myeloid lineage. Endocardial precursors appear to rapidly migrate to the site of heart tube formation, where they arrive prior to the bilateral myocardial primordia. Analysis of a newly discovered zebrafish Scl/Tal1 mutant showed an additional and previously undescribed role of this transcription factor during the development of the endocardium. In Scl/Tal1 mutant embryos, endocardial precursors are specified, but migration is severely defective and endocardial cells aggregate at the ventricular pole of the heart. We further show that the initial fusion of the bilateral myocardial precursor populations occurs independently of the endocardium and tal1 function. Our results suggest early separation of the two components of the primitive heart tube and imply Scl/Tal1 as an indispensable component of the molecular hierarchy that controls endocardium morphogenesis.

  17. File list: Oth.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CDV.10.AllAg.Endocardial_cells hg19 TFs and others Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.CDV.10.AllAg.Endocardial_cells.bed ...

  18. File list: Pol.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.CDV.05.AllAg.Endocardial_cells hg19 RNA polymerase Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.CDV.05.AllAg.Endocardial_cells.bed ...

  19. File list: Oth.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CDV.05.AllAg.Endocardial_cells hg19 TFs and others Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.CDV.05.AllAg.Endocardial_cells.bed ...

  20. File list: NoD.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.05.AllAg.Endocardial_cells hg19 No description Cardiovascular Endocardial c...ells DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.05.AllAg.Endocardial_cells.bed ...

  1. File list: NoD.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.10.AllAg.Endocardial_cells hg19 No description Cardiovascular Endocardial c...ells DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.10.AllAg.Endocardial_cells.bed ...

  2. File list: Oth.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CDV.50.AllAg.Endocardial_cells hg19 TFs and others Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.CDV.50.AllAg.Endocardial_cells.bed ...

  3. File list: InP.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.CDV.20.AllAg.Endocardial_cells hg19 Input control Cardiovascular Endocardial ce...lls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.CDV.20.AllAg.Endocardial_cells.bed ...

  4. File list: Pol.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.CDV.50.AllAg.Endocardial_cells hg19 RNA polymerase Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.CDV.50.AllAg.Endocardial_cells.bed ...

  5. File list: InP.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.CDV.10.AllAg.Endocardial_cells hg19 Input control Cardiovascular Endocardial ce...lls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.CDV.10.AllAg.Endocardial_cells.bed ...

  6. File list: Pol.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.CDV.10.AllAg.Endocardial_cells hg19 RNA polymerase Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.CDV.10.AllAg.Endocardial_cells.bed ...

  7. File list: Pol.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.CDV.20.AllAg.Endocardial_cells hg19 RNA polymerase Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.CDV.20.AllAg.Endocardial_cells.bed ...

  8. File list: ALL.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.CDV.05.AllAg.Endocardial_cells hg19 All antigens Cardiovascular Endocardial cel...ls DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.CDV.05.AllAg.Endocardial_cells.bed ...

  9. File list: ALL.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.CDV.50.AllAg.Endocardial_cells hg19 All antigens Cardiovascular Endocardial cel...ls DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.CDV.50.AllAg.Endocardial_cells.bed ...

  10. File list: InP.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.CDV.50.AllAg.Endocardial_cells hg19 Input control Cardiovascular Endocardial ce...lls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.CDV.50.AllAg.Endocardial_cells.bed ...

  11. File list: NoD.CDV.50.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.50.AllAg.Endocardial_cells hg19 No description Cardiovascular Endocardial c...ells DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.50.AllAg.Endocardial_cells.bed ...

  12. File list: ALL.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.CDV.20.AllAg.Endocardial_cells hg19 All antigens Cardiovascular Endocardial cel...ls DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.CDV.20.AllAg.Endocardial_cells.bed ...

  13. File list: ALL.CDV.10.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.CDV.10.AllAg.Endocardial_cells hg19 All antigens Cardiovascular Endocardial cel...ls DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.CDV.10.AllAg.Endocardial_cells.bed ...

  14. File list: NoD.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.20.AllAg.Endocardial_cells hg19 No description Cardiovascular Endocardial c...ells DRX014674 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.20.AllAg.Endocardial_cells.bed ...

  15. File list: Oth.CDV.20.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CDV.20.AllAg.Endocardial_cells hg19 TFs and others Cardiovascular Endocardial c...ells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.CDV.20.AllAg.Endocardial_cells.bed ...

  16. File list: InP.CDV.05.AllAg.Endocardial_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.CDV.05.AllAg.Endocardial_cells hg19 Input control Cardiovascular Endocardial ce...lls http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.CDV.05.AllAg.Endocardial_cells.bed ...

  17. Accelerated coronary angiogenesis by vegfr1-knockout endocardial cells.

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    Full Text Available During mouse heart development, ventricular endocardial cells give rise to the coronary arteries by angiogenesis. Myocardially-derived vascular endothelial growth factor-a (Vegfa regulates embryonic coronary angiogenesis through vascular endothelial growth factor-receptor 2 (Vegfr2 expressed in the endocardium. In this study, we investigated the role of endocardially-produced soluble Vegfr1 (sVegfr1 in the coronary angiogenesis. We deleted sVegfr1 in the endocardium of the developing mouse heart and found that this deletion resulted in a precocious formation of coronary plexuses. Using an ex vivo coronary angiogenesis assay, we showed that the Vegfr1-null ventricular endocardial cells underwent excessive angiogenesis and generated extensive endothelial tubular networks. We also revealed by qPCR analysis that expression of genes involved in the Vegf-Notch pathway was augmented in the Vegfr1-null hearts. We further showed that inhibition of Notch signaling blocked the formation of coronary plexuses by the ventricular endocardial cells. These results establish that Vegfr1 produced in the endocardium negatively regulates embryonic coronary angiogenesis, possibly by limiting the Vegf-Notch signaling.

  18. Endocardial tip cells in the human embryo - facts and hypotheses.

    Directory of Open Access Journals (Sweden)

    Mugurel C Rusu

    Full Text Available Experimental studies regarding coronary embryogenesis suggest that the endocardium is a source of endothelial cells for the myocardial networks. As this was not previously documented in human embryos, we aimed to study whether or not endothelial tip cells could be correlated with endocardial-dependent mechanisms of sprouting angiogenesis. Six human embryos (43-56 days were obtained and processed in accordance with ethical regulations; immunohistochemistry was performed for CD105 (endoglin, CD31, CD34, α-smooth muscle actin, desmin and vimentin antibodies. Primitive main vessels were found deriving from both the sinus venosus and aorta, and were sought to be the primordia of the venous and arterial ends of cardiac microcirculation. Subepicardial vessels were found branching into the outer ventricular myocardium, with a pattern of recruiting α-SMA+/desmin+ vascular smooth muscle cells and pericytes. Endothelial sprouts were guided by CD31+/CD34+/CD105+/vimentin+ endothelial tip cells. Within the inner myocardium, we found endothelial networks rooted from endocardium, guided by filopodia-projecting CD31+/CD34+/CD105+/ vimentin+ endocardial tip cells. The myocardial microcirculatory bed in the atria was mostly originated from endocardium, as well. Nevertheless, endocardial tip cells were also found in cardiac cushions, but they were not related to cushion endothelial networks. A general anatomical pattern of cardiac microvascular embryogenesis was thus hypothesized; the arterial and venous ends being linked, respectively, to the aorta and sinus venosus. Further elongation of the vessels may be related to the epicardium and subepicardial stroma and the intramyocardial network, depending on either endothelial and endocardial filopodia-guided tip cells in ventricles, or mostly on endocardium, in atria.

  19. In vivo measurement of swine endocardial convective heat transfer coefficient.

    Science.gov (United States)

    Tangwongsan, Chanchana; Will, James A; Webster, John G; Meredith, Kenneth L; Mahvi, David M

    2004-08-01

    We measured the endocardial convective heat transfer coefficient h at 22 locations in the cardiac chambers of 15 pigs in vivo. A thin-film Pt catheter tip sensor in a Wheatstone-bridge circuit, similar to a hot wire/film anemometer, measured h. Using fluoroscopy, we could precisely locate the steerable catheter sensor tip and sensor orientation in pigs' cardiac chambers. With flows, h varies from 2500 to 9500 W/m2 x K. With zero flow, h is approximately 2400 W/m2 x K. These values of h can be used for the finite element method modeling of radiofrequency cardiac catheter ablation.

  20. Endocardial fibrosarcoma in a reticulated python (Python reticularis).

    Science.gov (United States)

    Gumber, Sanjeev; Nevarez, Javier G; Cho, Doo-Youn

    2010-11-01

    A female, reticulated python (Python reticularis) of unknown age was presented with a history of lethargy, weakness, and distended coelom. Physical examination revealed severe dystocia and stomatitis. The reticulated python was euthanized due to a poor clinical prognosis. Postmortem examination revealed marked distention of the reproductive tract with 26 eggs (10-12 cm in diameter), pericardial effusion, and a slightly firm, pale tan mass (3-4 cm in diameter) adhered to the endocardium at the base of aorta. Based on histopathologic and transmission electron microscopic findings, the diagnosis of endocardial fibrosarcoma was made.

  1. 49 CFR 178.345-7 - Circumferential reinforcements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Circumferential reinforcements. 178.345-7 Section... reinforcements. (a) A cargo tank with a shell thickness of less than 3/8 inch must be circumferentially... tank heads. (1) Circumferential reinforcement must be located so that the thickness and...

  2. Guided Circumferential Waves in Layered Poroelastic Cylinders

    Directory of Open Access Journals (Sweden)

    Shah S.A.

    2016-12-01

    Full Text Available The present paper investigates the propagation of time harmonic circumferential waves in a two-dimensional hollow poroelastic cylinder with an inner shaft (shaft-bearing assembly. The hollow poroelastic cylinder and inner shaft are assumed to be infinite in axial direction. The outer surface of the cylinder is stress free and at the interface, between the inner shaft and the outer cylinder, it is assumed to be free sliding and the interfacial shear stresses are zero, also the normal stress and radial displacements are continuous. The frequency equation of guided circumferential waves for a permeable and an impermeable surface is obtained. When the angular wave number vanish the frequency equation of guided circumferential waves for a permeable and an impermeable surface degenerates and the dilatational and shear waves are uncoupled. Shear waves are independent of the nature of surface. The frequency equation of a permeable and an impermeable surface for bore-piston assembly is obtained as a particular case of the model under consideration when the outer radius of the hollow poroelastic cylinder tends to infinity. Results of previous studies are obtained as a particular case of the present study. Nondimensional frequency as a function of wave number is presented graphically for two types of models and discussed. Numerical results show that, in general, the first modes are linear for permeable and impermeable surfaces and the frequency of a permeable surface is more than that of an impermeable surface.

  3. Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

    Science.gov (United States)

    Thilenius, O G; Vitullo, D; Bharati, S; Luken, J; Lamberti, J J; Tatooles, C; Lev, M; Carr, I; Arcilla, R A

    1979-12-01

    Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

  4. S1pr2/Gα13 signaling regulates the migration of endocardial precursors by controlling endoderm convergence.

    Science.gov (United States)

    Xie, Huaping; Ye, Ding; Sepich, Diane; Lin, Fang

    2016-06-15

    Formation of the heart tube requires synchronized migration of endocardial and myocardial precursors. Our previous studies indicated that in S1pr2/Gα13-deficient embryos, impaired endoderm convergence disrupted the medial migration of myocardial precursors, resulting in the formation of two myocardial populations. Here we show that endoderm convergence also regulates endocardial migration. In embryos defective for S1pr2/Gα13 signaling, endocardial precursors failed to migrate towards the midline, and the presumptive endocardium surrounded the bilaterally-located myocardial cells rather than being encompassed by them. In vivo imaging of control embryos revealed that, like their myocardial counterparts, endocardial precursors migrated with the converging endoderm, though from a more anterior point, then moved from the dorsal to the ventral side of the endoderm (subduction), and finally migrated posteriorly towards myocardial precursors, ultimately forming the inner layer of the heart tube. In embryos defective for endoderm convergence due to an S1pr2/Gα13 deficiency, both the medial migration and the subduction of endocardial precursors were impaired, and their posterior migration towards the myocardial precursors was premature. This placed them medial to the myocardial populations, physically blocking the medial migration of the myocardial precursors. Furthermore, contact between the endocardial and myocardial precursor populations disrupted the epithelial architecture of the myocardial precursors, and thus their medial migration; in embryos depleted of endocardial cells, the myocardial migration defect was partially rescued. Our data indicate that endoderm convergence regulates the medial migration of endocardial precursors, and that premature association of the endocardial and myocardial populations contributes to myocardial migration defects observed in S1pr2/Gα13-deficient embryos. The demonstration that endoderm convergence regulates the synchronized

  5. CIRCUMFERENTIAL MFL IN-LINE INSPECTION FOR CRACKS IN PIPELINES

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Nestleroth

    2003-06-01

    Circumferential MFL is a new implementation of a widely used technology that has potential to provide improved detection and quantification of axially oriented defects such as cracks, seam weld defects, mechanical damage, and groove corrosion. This implementation works by orienting the magnetic field around the pipe rather that along the axis. By orienting the magnetic field around the pipe (the circumferential direction), the axial defects that were magnetically transparent can disrupt more of the magnetic field and can be more easily detected. Initial implementations of circumferential MFL have found that flux leakage from cracks at the interior of the pipe is small, and the signals from cracks are difficult to detect. The objective of this project is to improve detection of cracks by changing the implementation along with using data from overlapping and complementary inspection techniques. Two technology enhancements were investigated: Combining high- and low-magnetization technology for stress detection; and Combining axial and circumferential MFL methods. Although a method combining high- and low-magnetization technology showed promise for characterizing gouges cause by third party excavation equipment, its commercial development was not successful for two reasons. First, the stress diminishes the crack signal, while the opening of the crack increases the signal. The stress-induced changes in flux leakage around cracks were small and any critical information on the severity of cracks and crack-like defects is difficult to distinguish from changes caused by the crack opening and other inspection variables. Second, it is difficult to magnetize pipe material in the circumferential direction. A relatively low, non-uniform magnetization level produced by the circumferential magnetizer makes detection of changes due to stress extremely difficult. This project also examined combining axial and circumferential MFL to improve crack detection and distinguish cracks for

  6. Effectiveness and safety of simultaneous hybrid thoracoscopic and endocardial catheter ablation of lone atrial fibrillation

    NARCIS (Netherlands)

    Pison, Laurent; Gelsomino, Sandro; Lucà, Fabiana; Parise, Orlando; Maessen, Jos G; Crijns, Harry J G M; La Meir, Mark

    2014-01-01

    BACKGROUND: We evaluated the safety and effectiveness of the hybrid thoracoscopic endocardial epicardial technique for the treatment of lone atrial fibrillation. METHODS: Between 2009 and 2012, a cohort of 78 consecutive patients (median age 60.5 years, 77% male) underwent ablation of atrial fibrill

  7. Endocardial to myocardial notch-wnt-bmp axis regulates early heart valve development.

    Directory of Open Access Journals (Sweden)

    Yidong Wang

    Full Text Available Endocardial to mesenchymal transformation (EMT is a fundamental cellular process required for heart valve formation. Notch, Wnt and Bmp pathways are known to regulate this process. To further address how these pathways coordinate in the process, we specifically disrupted Notch1 or Jagged1 in the endocardium of mouse embryonic hearts and showed that Jagged1-Notch1 signaling in the endocardium is essential for EMT and early valvular cushion formation. qPCR and RNA in situ hybridization assays reveal that endocardial Jagged1-Notch1 signaling regulates Wnt4 expression in the atrioventricular canal (AVC endocardium and Bmp2 in the AVC myocardium. Whole embryo cultures treated with Wnt4 or Wnt inhibitory factor 1 (Wif1 show that Bmp2 expression in the AVC myocardium is dependent on Wnt activity; Wnt4 also reinstates Bmp2 expression in the AVC myocardium of endocardial Notch1 null embryos. Furthermore, while both Wnt4 and Bmp2 rescue the defective EMT resulting from Notch inhibition, Wnt4 requires Bmp for its action. These results demonstrate that Jagged1-Notch1 signaling in endocardial cells induces the expression of Wnt4, which subsequently acts as a paracrine factor to upregulate Bmp2 expression in the adjacent AVC myocardium to signal EMT.

  8. Evaluation of optical flow algorithms for tracking endocardial surfaces on three-dimensional ultrasound data

    Science.gov (United States)

    Duan, Qi; Angelini, Elsa D.; Herz, Susan L.; Ingrassia, Christopher M.; Gerard, Olivier; Costa, Kevin D.; Holmes, Jeffrey W.; Laine, Andrew F.

    2005-04-01

    With relatively high frame rates and the ability to acquire volume data sets with a stationary transducer, 3D ultrasound systems, based on matrix phased array transducers, provide valuable three-dimensional information, from which quantitative measures of cardiac function can be extracted. Such analyses require segmentation and visual tracking of the left ventricular endocardial border. Due to the large size of the volumetric data sets, manual tracing of the endocardial border is tedious and impractical for clinical applications. Therefore the development of automatic methods for tracking three-dimensional endocardial motion is essential. In this study, we evaluate a four-dimensional optical flow motion tracking algorithm to determine its capability to follow the endocardial border in three dimensional ultrasound data through time. The four-dimensional optical flow method was implemented using three-dimensional correlation. We tested the algorithm on an experimental open-chest dog data set and a clinical data set acquired with a Philips' iE33 three-dimensional ultrasound machine. Initialized with left ventricular endocardial data points obtained from manual tracing at end-diastole, the algorithm automatically tracked these points frame by frame through the whole cardiac cycle. A finite element surface was fitted through the data points obtained by both optical flow tracking and manual tracing by an experienced observer for quantitative comparison of the results. Parameterization of the finite element surfaces was performed and maps displaying relative differences between the manual and semi-automatic methods were compared. The results showed good consistency between manual tracing and optical flow estimation on 73% of the entire surface with fewer than 10% difference. In addition, the optical flow motion tracking algorithm greatly reduced processing time (about 94% reduction compared to human involvement per cardiac cycle) for analyzing cardiac function in three

  9. Characteristics of the Nonselective Cation Current (NSCCs) in Rabbit Left Ventricular Epicardial, Midmyocardial and Endocardial Myocytes

    Institute of Scientific and Technical Information of China (English)

    Min Zong; Xinchun Yang; Xiulan Liu; Liang Shi; Taifeng Liu

    2007-01-01

    Recent studies have described regional differences in the electrophysiology and pharmacology of ventricular myocardium in canine,feline,rat,guinea pig,and human hearts.This has been shown to be due to a smaller IKs and a lager sodium-calcium exchange current (INa-Ca ) and late INa in M region (deep subepicardial to midmyocardial).Studies from our laboratory have found a new repolarization current-nonselective cation current (NSCCs) existing in rabbit right ventricular myocytes.Methods We examined the characteristics of NSCCs in epicardial,M region,and endocardial cells isolated from the rabbit left ventricle with standard microelectrode and whole-cell patch-clamp techniques.The permeability to Na+,K + ,Li + ,Cs + but not to Cl-indicating that it was a nonselective cation current.Gd3+ (0.1 mmol/1) and La3+ (0.1 mmol/1) can block the current markedly.Results Further characterization of NSCCs was significantly smaller in M cells than in epicardial and endocardial cells.NSCCs current density was significantly smaller in M cells than in epicardial and endocardial cells.With repolarization to-80 mV,INs current density was (-0.44 ±0.05) PA/PF in endocardial cells,(-0.12 ±0.05) PA/PF in M cells and (-0.28 ±0.07) PA/PF in epicardial cells;and with repolarization to + 30 mV,INs current density was ( 1.09 ± 0.29) PA/PF in endocardial cells,(0.38 ± 0.09) PA/PF in M cells and (0.91 ± 0.32) PA/PF in epicardial cells.Conclusions Transmural dispersion of repolarization was due to the heterogeneity of NSCCs in rabbit left ventricle epicardial,endocardial myocytes and M cells.These findings may advance our understanding of the ionic basis for our understanding of factors contributing to the development of cardiac arrhythmias.

  10. Quantification of biventricular myocardial function using cardiac magnetic resonance feature tracking, endocardial border delineation and echocardiographic speckle tracking in patients with repaired tetralogy of fallot and healthy controls

    Directory of Open Access Journals (Sweden)

    Kempny Aleksander

    2012-05-01

    Full Text Available Abstract Background Parameters of myocardial deformation have been suggested to be superior to conventional measures of ventricular function in patients with tetralogy of Fallot (ToF, but have required non-routine, tagged cardiovascular magnetic resonance (CMR techniques. We assessed biventricular myocardial function using CMR cine-based feature tracking (FT and compared it to speckle tracking echocardiography (STE and to simple endocardial border delineation (EBD. In addition, the relation between parameters of myocardial deformation and clinical parameters was assessed. Methods Overall, 28 consecutive adult patients with repaired ToF (age 40.4 ± 13.3 years underwent standard steady-state-free precession sequence CMR, echocardiography, and cardiopulmonary exercise testing. In addition, 25 healthy subjects served as controls. Myocardial deformation was assessed by CMR based FT (TomTec Diogenes software, CMR based EBD (using custom written software and STE (TomTec Cardiac Performance Analysis software. Results Feature tracking was feasible in all subjects. A close agreement was found between measures of global left (LV and right ventricular (RV global strain. Interobserver agreement for FT and STE was similar for longitudinal LV global strain, but FT showed better inter-observer reproducibility than STE for circumferential or radial LV and longitudinal RV global strain. Reproducibility of regional strain on FT was, however, poor. The relative systolic length change of the endocardial border measured by EBD yielded similar results to FT global strain. Clinically, biventricular longitudinal strain on FT was reduced compared to controls (P 2-slope. Conclusions Although neither the inter-study reproducibility nor accuracy of FT software were investigated, and its inter-observer reproducibility for regional strain calculation was poor, its calculations of global systolic strain showed similar or better inter-oberver reproducibility than those

  11. Structural and leakage integrity of tubes affected by circumferential cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hernalsteen, P. [TRACTEBEL, Brussels (Belgium)

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  12. Circumferential gap propagation in an anisotropic elastic bacterial sacculus

    CERN Document Server

    Taneja, Swadhin; Rutenberg, Andrew D

    2013-01-01

    We have modelled stress concentration around small gaps in anisotropic elastic sheets, corresponding to the peptidoglycan sacculus of bacterial cells, under loading corresponding to the effects of turgor pressure in rod-shaped bacteria. We find that under normal conditions the stress concentration is insufficient to mechanically rupture bacteria, even for gaps up to a micron in length. We then explored the effects of stress-dependent smart-autolysins, as hypothesised by Arthur L Koch [Advances in Microbial Physiology 24, 301 (1983); Research in Microbiology 141, 529 (1990)]. We show that the measured anisotropic elasticity of the PG sacculus can lead to stable circumferential propagation of small gaps in the sacculus. This is consistent with the recent observation of circumferential propagation of PG-associated MreB patches in rod-shaped bacteria. We also find a bistable regime of both circumferential and axial gap propagation, which agrees with behavior reported in cytoskeletal mutants of B. subtilis. We con...

  13. GUIDED CIRCUMFERENTIAL WAVES IN DOUBLE-WALLED CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A model of guided circumferential waves propagating in double-walled carbon nanotubes is built by the theory of wave propagation in continuum mechanics, while the van der Waals force between the inner and outer nanotube has been taken into account in the model. The dispersion curves of the guided circumferential wave propagation are studied, and some dispersion characteristics are illustrated by comparing with those of single-walled carbon nanotubes. It is found that in double-walled carbon nanotubes, the guided circumferential waves will propagate in more dispersive ways. More interactions between neighboring wave modes may take place. In particular, it has been found that a couple of wave modes may disappear at a certain frequency and that, while a couple of wave modes disappear, another new couple of wave modes are excited at the same wave number.

  14. Magnetic resonance imaging characterization of circumferential and longitudinal strain under various coronary interventions in swine

    Institute of Scientific and Technical Information of China (English)

    Mohammed; SA; Suhail; Mark; W; Wilson; Steven; W; Hetts; Maythem; Saeed

    2013-01-01

    AIM:To compare the acute changes in circumferential and longitudinal strain after exposing a coronary artery to various interventions in swine.METHODS:Percutaneous balloon angioplasty catheter was guided to location aid device(LAD)under X-ray fluoroscopy to create different patterns of ischemic insults.Pigs(n=32)were equally divided into 4 groups:controls,90 min LAD occlusion/reperfusion,LAD microembolization,and combined LAD occlusion/microembolization/reperfusion.Three days after interventions,cine,tagged and viability magnetic resonance imaging(MRI)were acquired to measure and compare left and right circumferential strain,longitudinal strain and myocardial viability,respectively.Measurements were obtained using HARP and semi-automated threshold method and statistically analyzed using unpaired t-test.Myocardial and vascular damage was characterized microscopically.RESULTS:Coronary microemboli caused greater impairment in l left ventricular(LV)circumferential strain and dyssynchrony than LAD occlusion/reperfusion despite the significant difference in the extent of myocardial damage.Microemboli also caused significant decrease in peak systolic strain rate of remote myocardium and LV dyssynchrony.Cine MRI demonstrated the interaction between LV and right ventricular(RV)at 3 d after interventions.Compensatory increase in RV free wall longitudinal strain was seen in response to all interventions.Viability MRI,histochemical staining and microscopy revealed different patterns of myocardial damage and microvascular obstruction.CONCLUSION:Cine MRI revealed subtle changes in LV strain caused by various ischemic insults.It also demonstrated the interaction between the right and left ventricles after coronary interventions.Coronary microemboli with and without acute myocardial infarction(AMI)cause complex myocardial injury and ventricular dysfunction that is not replicated in solely AMI.

  15. Circumferential nonlocal effect on the buckling and vibration of nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cheng Yuan, E-mail: cywang@ujs.edu.cn; Li, Xiao Hu; Luo, Ying

    2016-04-01

    The nonlocal beam theories are widely used to study the mechanics of cylindrical nanotubes (NTs). The one-dimensional models however are unable to account for the nonlocal effect in the circumferential direction, which may substantially affect the applicability of the nonlocal beam models. To address the issue this letter examines the circumferential nonlocal effect (CNE) on the buckling and vibration of the NTs. Here the CNE is characterized by the difference between the nonlocal beam model considering the axial nonlocal effect only and the nonlocal shell model with both axial and circumferential nonlocal effects. The aspect ratio and radius-dependence of the CNE are calculated for the singlewall carbon NTs selected as a typical example. The results show that the CNE is substantial for the buckling and vibration of the NTs with small radius (e.g., <1 nm) and aspect ratio (e.g., <15). It however decreases with the rising radius and the aspect ratio, and turns out to be small for relatively wide and long NTs. The nonlocal beam theories thus may overestimate the buckling load and vibration frequency for the thin and short NTs. - Highlights: • First revealed the substantial circumferential nonlocal effect (CNE) on nanotube buckling. • Achieved radius/aspect ratio-dependence of CNE on nanotube buckling and vibration. • Located the range of applicability of the nonlocal beam theory without CNE.

  16. A Critical Appraisal of Circumferential Resection Margins in Esophageal Carcinoma

    NARCIS (Netherlands)

    Pultrum, Bareld B.; Honing, Judith; Smit, Justin K.; van Dullemen, Hendrik M.; van Dam, Gooitzen M.; Groen, Henk; Hollema, Harry; Plukker, John Th. M.

    2010-01-01

    In esophageal cancer, circumferential resection margins (CRMs) are considered to be of relevant prognostic value, but a reliable definition of tumor-free CRM is still unclear. The aim of this study was to appraise the clinical prognostic value of microscopic CRM involvement and to determine the opti

  17. Circumferential evaluation of the neointima by optical coherence tomography after ABSORB bioresorbable vascular scaffold implantation

    DEFF Research Database (Denmark)

    Brugaletta, Salvatore; Radu, Maria D; Garcia-Garcia, Hector M

    2012-01-01

    To quantify the circumferential healing process at 6 and 12 months following scaffold implantation.......To quantify the circumferential healing process at 6 and 12 months following scaffold implantation....

  18. Status of the steam generator tube circumferential ODSCC degradation experienced at the Doel 4 plant

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, G. [AIB-Vincotte Nuclear, Brussels (Belgium)

    1997-02-01

    Since the 1991 outage, the Doel Unit 4 nuclear power plant is known to be affected by circumferential outside diameter intergranular stress corrosion cracking at the hot leg tube expansion transition. Extensive non destructive examination inspections have shown the number of tubes affected by this problem as well as the size of the cracks to have been increasing for the three cycles up to 1993. As a result of the high percentage of tubes found non acceptable for continued service after the 1993 in-service inspection, about 1,700 mechanical sleeves were installed in the steam generators. During the 1994 outage, all the tubes sleeved during the 1993 outage were considered as potentially cracked to some extent at the upper hydraulic transition and were therefore not acceptable for continued service. They were subsequently repaired by laser welding. Furthermore all the tubes not sleeved during the 1993 outage were considered as not acceptable for continued service and were repaired by installing laser welded sleeves. During the 1995 outage, some unexpected degradation phenomena were evidenced in the sleeved tubes. This paper summarizes the status of the circumferential ODSCC experienced in the SG tubes of the Doel 4 plant as well as the other connected degradation phenomena.

  19. Association between High Endocardial Unipolar Voltage and Improved Left Ventricular Function in Patients with Ischemic Cardiomyopathy.

    Science.gov (United States)

    Park, Ki; Lai, Dejian; Handberg, Eileen M; Moyé, Lem; Perin, Emerson C; Pepine, Carl J; Anderson, R David

    2016-08-01

    We know that endocardial mapping reports left ventricular electrical activity (voltage) and that these data can predict outcomes in patients undergoing traditional revascularization. Because the mapping data from experimental models have also been linked with myocardial viability, we hypothesized an association between increased unipolar voltage in patients undergoing intramyocardial injections and their subsequent improvement in left ventricular performance. For this exploratory analysis, we evaluated 86 patients with left ventricular dysfunction, heart-failure symptoms, possible angina, and no revascularization options, who were undergoing endocardial mapping. Fifty-seven patients received bone marrow mononuclear cell (BMC) injections and 29 patients received cell-free injections of a placebo. The average mapping site voltage was 9.7 ± 2 mV, and sites with voltage of ≥6.9 mV were engaged by needle and injected (with BMC or placebo). For all patients, at 6 months, left ventricular ejection fraction (LVEF) improved, and after covariate adjustment this improvement was best predicted by injection-site voltage. For every 2-mV increase in baseline voltage, we detected a 1.3 increase in absolute LVEF units for all patients (P=0.038). Multiple linear regression analyses confirmed that voltage and the CD34(+) count present in bone marrow (but not treatment assignment) were associated with improved LVEF (P=0.03 and P=0.014, respectively). In an exploratory analysis, higher endocardial voltage and bone marrow CD34(+) levels were associated with improved left ventricular function among ischemic cardiomyopathy patients. Intramyocardial needle injections, possibly through stimulation of angiogenesis, might serve as a future therapy in patients with reduced left ventricular function and warrants investigation.

  20. Retinoic Acid Signaling Is Essential for Valvulogenesis by Affecting Endocardial Cushions Formation in Zebrafish Embryos.

    Science.gov (United States)

    Li, Junbo; Yue, Yunyun; Zhao, Qingshun

    2016-02-01

    Retinoic acid (RA) plays important roles in many stages of heart morphogenesis. Zebrafish embryos treated with exogenous RA display defective atrio-ventricular canal (AVC) specification. However, whether endogenous RA signaling takes part in cardiac valve formation remains unknown. Herein, we investigated the role of RA signaling in cardiac valve development by knocking down aldh1a2, the gene encoding an enzyme that is mainly responsible for RA synthesis during early development, in zebrafish embryos. The results showed that partially knocking down aldh1a2 caused defective formation of primitive cardiac valve leaflets at 108 hpf (hour post-fertilization). Inhibiting endogenous RA signaling by 4-diethylaminobenzal-dehyde revealed that 16-26 hpf was a key time window when RA signaling affects the valvulogenesis. The aldh1a2 morphants had defective formation of endocardial cushion (EC) at 76 hpf though they had almost normal hemodynamics and cardiac chamber specification at early development. Examining the expression patterns of AVC marker genes including bmp4, bmp2b, nppa, notch1b, and has2, we found the morphants displayed abnormal development of endocardial AVC but almost normal development of myocardial AVC at 50 hpf. Being consistent with the reduced expression of notch1b in endocardial AVC, the VE-cadherin gene cdh5, the downstream gene of Notch signaling, was ectopically expressed in AVC of aldh1a2 morphants at 50 hpf, and overexpression of cdh5 greatly affected the formation of EC in the embryos at 76 hpf. Taken together, our results suggest that RA signaling plays essential roles in zebrafish cardiac valvulogenesis.

  1. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.

    2011-03-01

    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  2. Thermal shock in a circumferentially cracked hollow cylinder with cladding

    Science.gov (United States)

    Nied, H. F.

    1984-01-01

    An theoretical analysis is presented which demonstrates the effect of cladding on the thermal resistance of a circumferentially cracked hollow cylinder. The cladding is assumed to be bonded to the inner wall of the hollow cylinder. The axisymmetric circumferential crack may be either embedded in the cylinder wall or may be an edge crack which passes through the clad and opens into the inner wall of the hollow cylinder. The problem is formulated mathematically and a solution is found which is in the form of a single integral equation. The integral equation is solved numerically and yields estimates of transient temperature distributions, thermal stresses in the uncracked cylinder, and stress intensity factors as a function of time for various cladding thickness to cylinder wall thickness ratios. It is shown that yielding of the clad under certain conditions can result in a reduction in the magnitude of the stress intensity factor for the crack tip in the elastic base material.

  3. Circumferential fusion improves outcome in comparison with instrumented posterolateral fusion

    DEFF Research Database (Denmark)

    Videbaek, Tina S; Christensen, Finn B; Soegaard, Rikke;

    2006-01-01

    with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression, and social interest. The Oswestry Disability Index supported these results (P physical health (P ...STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion...... fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were the Oswestry Disability Index, the SF...

  4. Epicardial and endocardial mapping determine most successful site of ablation for ventricular tachyarrhythmias originating from left ventricular summit.

    Science.gov (United States)

    Iijima, Kenichi; Chinushi, Masaomi; Furushima, Hiroshi; Aizawa, Yoshifusa

    2012-06-01

    A 34-year-old woman presented with idiopathic premature ventricular complex (PVC) and ventricular tachycardia (VT) originating from the area called the left ventricular summit. Radiofrequency (RF) application both through the coronary sinus and to the epicardial surface transiently suppressed the VT/PVC. Radiofrequency with sufficient energy was only applicable from the endocardial site, and the VT/PVC was successfully eliminated.

  5. Range_Extent_15

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS layer "Range_extent_15" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris nereis) in mainland...

  6. Detection of a longitudinal defect in a pipe based on guided circumferential waves techniques

    Institute of Scientific and Technical Information of China (English)

    LI Longtao; HE Cunfu; WU Bin

    2005-01-01

    Based on elasticity theory, the multi-modes and disperse characteristics of guided circumferential waves in a pipe were investigated theoretically and experimentally, the disperse curves of guided circumferential waves were gotten by numerical calculations. The relationships between the angle of beam transducer, frequency and guided circumferential modes were analyzed by our guided wave experiment system. Then single guided circumferential mode was excited in the pipe (O.D 88.8 mm, I.D 80.8 mm). An artificial longitudinal defect (25 × 1 × 0.7 mm)on the surface of the pipe was detected by use of the single guided circumferential wave. The results show that single guided circumferential mode can be excited in the pipe by choosing special frequency and special angle beam transducer, similar to the excitation of Lamb wave in a plate, and it can be used to find the longitudinal defect on a pipe surface.

  7. Automatic generation of endocardial surface meshes with 1-to-1 correspondence from cine-MR images

    Science.gov (United States)

    Su, Yi; Teo, S.-K.; Lim, C. W.; Zhong, L.; Tan, R. S.

    2015-03-01

    In this work, we develop an automatic method to generate a set of 4D 1-to-1 corresponding surface meshes of the left ventricle (LV) endocardial surface which are motion registered over the whole cardiac cycle. These 4D meshes have 1- to-1 point correspondence over the entire set, and is suitable for advanced computational processing, such as shape analysis, motion analysis and finite element modelling. The inputs to the method are the set of 3D LV endocardial surface meshes of the different frames/phases of the cardiac cycle. Each of these meshes is reconstructed independently from border-delineated MR images and they have no correspondence in terms of number of vertices/points and mesh connectivity. To generate point correspondence, the first frame of the LV mesh model is used as a template to be matched to the shape of the meshes in the subsequent phases. There are two stages in the mesh correspondence process: (1) a coarse matching phase, and (2) a fine matching phase. In the coarse matching phase, an initial rough matching between the template and the target is achieved using a radial basis function (RBF) morphing process. The feature points on the template and target meshes are automatically identified using a 16-segment nomenclature of the LV. In the fine matching phase, a progressive mesh projection process is used to conform the rough estimate to fit the exact shape of the target. In addition, an optimization-based smoothing process is used to achieve superior mesh quality and continuous point motion.

  8. Increased Hemodynamic Load in Early Embryonic Stages Alters Endocardial to Mesenchymal Transition

    Science.gov (United States)

    Midgett, Madeline; López, Claudia S.; David, Larry; Maloyan, Alina; Rugonyi, Sandra

    2017-01-01

    Normal blood flow is essential for proper heart formation during embryonic development, as abnormal hemodynamic load (blood pressure and shear stress) results in cardiac defects seen in congenital heart disease. However, the progressive detrimental remodeling processes that relate altered blood flow to cardiac defects remain unclear. Endothelial–mesenchymal cell transition is one of the many complex developmental events involved in transforming the early embryonic outflow tract into the aorta, pulmonary trunk, interventricular septum, and semilunar valves. This study elucidated the effects of increased hemodynamic load on endothelial–mesenchymal transition remodeling of the outflow tract cushions in vivo. Outflow tract banding was used to increase hemodynamic load in the chicken embryo heart between Hamburger and Hamilton stages 18 and 24. Increased hemodynamic load induced increased cell density in outflow tract cushions, fewer cells along the endocardial lining, endocardium junction disruption, and altered periostin expression as measured by confocal microscopy analysis. In addition, 3D focused ion beam scanning electron microscopy analysis determined that a portion of endocardial cells adopted a migratory shape after outflow tract banding that is more irregular, elongated, and with extensive cellular projections compared to normal cells. Proteomic mass-spectrometry analysis quantified altered protein composition after banding that is consistent with a more active stage of endothelial–mesenchymal transition. Outflow tract banding enhances the endothelial–mesenchymal transition phenotype during formation of the outflow tract cushions, suggesting that endothelial–mesenchymal transition is a critical developmental process that when disturbed by altered blood flow gives rise to cardiac malformation and defects. PMID:28228731

  9. Estimation of circumferential fiber shortening velocity by echocardiography.

    Science.gov (United States)

    Ruschhaupt, D G; Sodt, P C; Hutcheon, N A; Arcilla, R A

    1983-07-01

    The M-mode and two-dimensional echocardiograms of 40 young patients were analyzed to compare the mean circumferential fiber shortening velocity (Vcf) of the left ventricle calculated separately by two methods. The mean circumferential fiber shortening velocity was derived from the M-mode echocardiogram as minor axis shortening/ejection time and derived from the two-dimensional echocardiogram as actual circumference change/ejection time. With computer assistance, circumference was determined from the short-axis two-dimensional echocardiographic images during end-diastole and end-systole. Good correlations were obtained between the left ventricular diameter derived by M-mode echocardiography and the vertical axis during end-diastole (r = 0.79) and end-systole (r = 0.88) derived by two-dimensional echocardiography. Likewise, high correlations were noted between diameter and circumference in end-diastole (r = 0.89) and end-systole (r = 0.88). However, comparison of Vcf obtained by M-mode echocardiography with that obtained by two-dimensional echocardiography showed only fair correlation (r = 0.68). Moreover, the diameter/circumference ratio determined in end-diastole and end-systole differed significantly (p less than 0.001), possibly owing to the change in geometry of the ventricular sector image during systole. Although Vcf derived by M-mode echocardiography is a useful index of left ventricular performance, it does not truly reflect the circumference change during systole.

  10. DETERMINATION OF EFFICIENCY OF THE CIRCUMFERENTIAL DRAINAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Maciej Kroll

    2015-11-01

    Full Text Available One of the potential alternatives to improve the stability coefficient for an embankment structure is to flatten the filtration curve. As a result, we obtain lower body forces triggering the potential landslide and more advantageous soil strength parameters, which counteract landslide movements. In the case of waste dumps lowering the phreatic surface of waters is achieved thanks to the construction of auxiliary drainage systems, meeting the guidelines for their safe operation. The aim of this paper is to indicate a method facilitating the determination of the actual position of the phreatic surface within the deposited sediments and the assessment of efficiency of the circumferential drainage system in the waste dump. It was decided in this study to apply cone penetration test CPTU. The CPTU made it possible to measure dissipation of excess water pressure in pores identifying drainage conditions, which were compared with the results of piezometric measurements. The results of these tests made it possible to monitor changes in the position of the depression curve of supernatant waters in dams and to determine the efficiency of the circumferential drainage system.

  11. Characterization of mechanical and geometrical properties of a tube with axial and circumferential guided waves.

    Science.gov (United States)

    Yeh, Cheng-Hung; Yang, Che-Hua

    2011-05-01

    Guided waves propagating in cylindrical tubes are frequently applied for the characterization of material or geometrical properties of tubes. In a tube, guided waves can propagate in the axial direction and called axial guided waves, or in the circumferential direction called circumferential guided waves. Dispersion spectra for the axial and circumferential guided waves share some common behaviors and however exhibit some particular behaviors of their own. This study provides an investigation with theoretical modeling, experimental measurements, and a simplex-based inversion procedure to explore the similarity and difference between the axial guided waves and circumferential guided waves, aiming at providing useful information while axial and circumferential guided waves are applied in the area of material characterization. The sensitivity to the radius curvature for the circumferential guided waves dispersion spectra is a major point that makes circumferential guided waves different from axial guided waves. For the purpose of material characterization, both axial and circumferential guided waves are able to extract an elastic moduli and wall-thickness information from the dispersion spectra, however, radius information can only be extracted from the circumferential guided waves spectra.

  12. In-treatment midwall and endocardial fractional shortening predict cardiovascular outcome in hypertensive patients with preserved baseline systolic ventricular function: the Losartan Intervention For Endpoint reduction study

    DEFF Research Database (Denmark)

    Wachtell, Kristian; Gerdts, Eva; Palmieri, Vittorio;

    2010-01-01

    Endocardial fractional shortening (EFS) and midwall shortening (MWS) are impaired in patients with left ventricular hypertrophy. However, it remains unknown whether improvement of left ventricular systolic function during treatment reduces cardiovascular morbidity and mortality in hypertensive pa...

  13. Low-frequency circumferential magnetization curves in magnetostrictive amorphous wires

    Energy Technology Data Exchange (ETDEWEB)

    Olivera, J. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Sanchez, M.L. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Prida, V.M. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Perez, M.J. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Santos, J.D. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Gorria, P. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain); Hernando, B. [Departamento de Fisica, Universidad de Oviedo, C/Calvo Sotelo s/n, 33007 Oviedo (Spain)]. E-mail: grande@pinon.ccu.uniovi.es; Sanchez Ll, J.L. [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, La Habana 10400 (Cuba)

    2005-07-15

    Circumferential magnetization curves have been derived from the imaginary component of the impedance response in an Fe{sub 73.5}Si{sub 13.5}B{sub 9}Cu{sub 1}Nb{sub 3} amorphous wire. Measurements were performed at 1 kHz driving frequency, and 0.05- 20 mA{sub rms} current amplitude range. Axial DC fields from 0 to 100 Oe have been simultaneously applied in order to detect the magnetoinductive effect. The circular magnetization curves are compared with quasi-static longitudinal magnetization ones, and the results are analyzed on the basis of the core-shell model for a wire with positive magnetostriction.

  14. Transverse shear effect in a circumferentially cracked cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1979-01-01

    The objectives of the paper are to solve the problem of a circumferentially-cracked cylindrical shell by taking into account the effect of transverse shear, and to obtain the stress intensity factors for the bending moment as well as the membrane force as the external load. The formulation of the problem is given for a specially orthotropic material within the framework of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions as to moment and stress resultants on the crack surface. The effect of Poisson's ratio on the stress intensity factors and the nature of the out-of-plane displacement along the edges of the crack, i.e., bulging, are also studied.

  15. The use of circumferentially varying stagger guide vanes in an axial flow pump or compressor

    Science.gov (United States)

    Horlock, J. H.

    1990-04-01

    An actuator disk analysis is given of the flow through a guide vane and rotor combination. It is shown that changes in total pressure across the rotor are, in general, related to circumferential variations in guide vane outlet angle. In particular, known variations in inlet total pressure may be eliminated by suitable circumferential changes in guide vane stagger.

  16. Automated classification of wall motion abnormalities by principal component analysis of endocardial shape motion patterns in echocardiograms

    Science.gov (United States)

    Bosch, Johan G.; Nijland, Francisca; Mitchell, Steven C.; Lelieveldt, Boudewijn P. F.; Kamp, Otto; Sonka, Milan; Reiber, Johan H. C.

    2003-05-01

    Principal Component Analysis of sets of temporal shape sequences renders eigenvariations of shape/motion, including typical normal and pathological endocardial contraction patterns. A previously developed Active Appearance Model for time sequences (AAMM) was employed to derive AAMM shape coefficients (ASCs) and we hypothesized these would allow classification of wall motion abnormalities (WMA). A set of stress echocardiograms (single-beat 4-chamber and 2-chamber sequences with expert-verified endocardial contours) of 129 infarct patients was split randomly into training (n=65) and testing (n=64) sets. AAMMs were generated from the training set and for all sequences ASCs were extracted and statistically related to regional/global Visual Wall Motion Scoring (VWMS) and clinical infarct severity and volumetric parameters. Linear regression showed clear correlations between ASCs and VWMS. Infarct severity measures correlated poorly to both ASCs and VWMS. Discriminant analysis showed good prediction from low #ASCs of both segmental (85% correctness) and global WMA (90% correctness). Volumetric parameters correlated poorly to regional VWMS. Conclusions: 1)ASCs show promising accuracy for automated WMA classification. 2)VWMS and endocardial border motion are closely related; with accurate automated border detection, automated WMA classification should be feasible. 3)ASC shape analysis allows contour set evaluation by direct comparison to clinical parameters.

  17. Qualitative and quantitative effects of harmonic echocardiographic imaging on endocardial edge definition and side-lobe artifacts

    Science.gov (United States)

    Rubin, D. N.; Yazbek, N.; Garcia, M. J.; Stewart, W. J.; Thomas, J. D.

    2000-01-01

    Harmonic imaging is a new ultrasonographic technique that is designed to improve image quality by exploiting the spontaneous generation of higher frequencies as ultrasound propagates through tissue. We studied 51 difficult-to-image patients with blinded side-by-side cineloop evaluation of endocardial border definition by harmonic versus fundamental imaging. In addition, quantitative intensities from cavity versus wall were compared for harmonic versus fundamental imaging. Harmonic imaging improved left ventricular endocardial border delineation over fundamental imaging (superior: harmonic = 71.1%, fundamental = 18.7%; similar: 10.2%; P Quantitative analysis of 100 wall/cavity combinations demonstrated brighter wall segments and more strikingly darker cavities during harmonic imaging (cavity intensity on a 0 to 255 scale: fundamental = 15.6 +/- 8.6; harmonic = 6.0 +/- 5.3; P <.0001), which led to enhanced contrast between the wall and cavity (1.89 versus 1.19, P <.0001). Harmonic imaging reduces side-lobe artifacts, resulting in a darker cavity and brighter walls, thereby improving image contrast and endocardial delineation.

  18. Angular-profile tuning of guided waves in hollow cylinders using a circumferential phased array.

    Science.gov (United States)

    Li, Jian; Rose, Joseph L

    2002-12-01

    Angular-profile tuning of guided waves in hollow cylinders is implemented by using partial loading of the elements in a circumferentially placed phased array. Each partial loading element generates nonaxisymmetric guided waves in a pipe. In earlier work, numerical calculations and experiments have shown that, for nonaxisymmetric guided waves, circumferential distribution of particle displacements (i.e., the angular profile) changes with propagation distance, frequency, and mode. To change the angular profile at a certain distance, either frequency or mode has to be changed for a single partial loading element. This is not the case, however, for a circumferential phased array. The total angular profile of a circumferential array is the superposition of contributions from all elements. If given the knowledge of the angular profile for a single element, the total guided wave angular profile can be controlled and thus focused at any specific circumferential location by a circumferentially placed phased array with adjustable voltage level and phase inputs. This angular profile tuning technique can be used for implementing a circumferential scan with focused, guided wave beams, which leads to the detection of smaller defects as a result of stronger focused beams. Algorithms and specific nondestructive evaluation (NDE) applications for pipe inspection using this technique are discussed.

  19. Fracture behavior of short circumferentially surface-cracked pipe

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswamy, P.; Scott, P.; Mohan, R. [Battelle, Columbus, OH (United States)] [and others

    1995-11-01

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission`s (NRC) research program entitled ``Short Cracks in Piping and Piping Welds`` that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC`s PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria.

  20. Nonlinear giant magnetoimpedance and the asymmetric circumferential magnetization process in soft magnetic wires

    Science.gov (United States)

    Gómez-Polo, C.; Duque, J. G. S.; Knobel, M.

    2004-07-01

    The magnetoimpedance effect and its nonlinear terms are analysed for a (Co0.94Fe0.06)72.5Si12.5B15 amorphous wire. In order to enhance the nonlinear contribution the sample was previously subjected to current annealing (Joule heating) to induce a circumferential anisotropy. The effect of the application of a torsional strain on the nonlinear magnetoimpedance is analysed in terms of the torsional dependence of the magnetic permeability, evaluated through experimental circumferential hysteresis loops. The results obtained clearly confirm the direct correlation between the asymmetric circumferential magnetization process and the occurrence of nonlinear second-harmonic terms in the magnetoimpedance voltage.

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

    Science.gov (United States)

    Chen, Tungyang; Yu, Shang-Ru

    2010-11-01

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

  2. Reduced Circumferential Resection Margin Involvement in Rectal Cancer Surgery: Results of the Dutch Surgical Colorectal Audit

    NARCIS (Netherlands)

    Gietelink, L.; Wouters, M.W.; Tanis, P.J.; Deken, M.M.; Berge, M.G. Ten; Tollenaar, R.A.; Krieken, J.H.J.M. van; Noo, M.E. de

    2015-01-01

    BACKGROUND: The circumferential resection margin (CRM) is a significant prognostic factor for local recurrence, distant metastasis, and survival after rectal cancer surgery. Therefore, availability of this parameter is essential. Although the Dutch total mesorectal excision trial raised awareness ab

  3. Variation in circumferential resection margin: Reporting and involvement in the South-Netherlands

    NARCIS (Netherlands)

    Homan, J.; Bokkerink, G.M.J.; Aarts, M.J.; Lemmens, V.E.; Lijnschoten, G. van; Rutten, H.J.; Wijsman, J.H.; Nagtegaal, I.D.; Wilt, J.H.W. de

    2015-01-01

    BACKGROUND: Since the introduction of total mesorectal surgery the outcome of rectal cancer patients has improved significantly. Involvement of the circumferential resection margin (CRM) is an important predictor of increased local recurrence, distant metastases and decreased overall survival. Abdom

  4. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  5. ISSLS prize winner: cost-effectiveness of two forms of circumferential lumbar fusion

    DEFF Research Database (Denmark)

    Freeman, Brian J C; Steele, Nicholas A; Sach, Tracey H

    2007-01-01

    STUDY DESIGN: Economic evaluation alongside a prospective, randomized controlled trial from a secondary care National Health Service (NHS) perspective. OBJECTIVE: To determine the cost-effectiveness of titanium cages (TC) compared with femoral ring allografts (FRA) in circumferential lumbar spina...

  6. Effect of strength matching on the reliability of welded pipe with circumferential surface crack

    Institute of Scientific and Technical Information of China (English)

    何柏林; 于影霞; 霍立兴; 张玉凤

    2004-01-01

    For different strength matching, the reliability index and failure probability of welded pressure pipe with circumferential surface crack were calculated using three dimensional stochastic finite element method. This method has overcome the shortcomings of conservative results in safety assessment with deterministic fracture mechanics method. The effects of external moment and the depth of the circumferential surface crack (a) on the reliability of pressure pipe were also calculated and discussed. The calculation results indicate that the strength matching has certain effect on the reliability of the welded pressure pipe with circumferential surface crack. The failure probability of welded pressure pipe with high strength matching is lower than that with low strength matching at the same conditions. The effects of strength matching on the failure probability and reliability index increased by adding external moment (M) and the depth of the circumferential surface crack (a).

  7. Understanding the link between circumferential dikes and eruptive fissures around calderas based on numerical and analog models

    Science.gov (United States)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-06-01

    Active calderas are seldom associated with circumferential eruptive fissures, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential fissure development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential fissures.

  8. Analyses of axial, lateral and circumferential deformations of rock specimen in triaxial compression

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-bin

    2008-01-01

    The axial, lateral and circumferential strains were analyzed for a rock specimen subjected to shear failure in the form of a shear band bisecting the specimen in triaxial compression. Plastic deformation of the specimen stemmed from shear strain localization initiated at the peak shear stress. Beyond the onset of strain localization, the axial, lateral and circumferential strains were decomposed into two parts, respectively. One is the elas-tic strain described by general Hooke's law. The other is attributable to the plastic shear slips along shear band with a certain thickness dependent on the internal length of rock.The post-peak circumferential strain-axial strain curve of longer specimen is steeper than that of shorter specimen, as is consistent with the previous experiments. In elastic stage,the circumferential strain-axial strain curve exhibits nonlinear characteristic, as is in agreement with the previous experiment since confining pressure is loaded progressively until a certain value is reached. When the confining pressure is loaded completely, the circumferential strain-axial strain curve is linear in elastic and strain-softening stages. The predicted circumferential strain-axial strain curve in elastic and strain- softening stages agrees with the previous experiment.

  9. Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. II. Effects on regional myocardial blood flow.

    Science.gov (United States)

    Ungerleider, R M; Holman, W L; Stanley, T E; Lofland, G K; Williams, J M; Smith, P K; Quick, G; Cox, J L

    1982-06-01

    Previous experimental studies of the encircling endocardial ventriculotomy (EEV) have shown a significant alteration of normal local electrical activity within the encompassed region. Although this procedure may result in isolation of ventricular arrhythmias, the data are more suggestive of a less specific effect on regional myocardial blood flow. This study examines the effect of EEV on local myocardial blood flow using the radioactive tracer microsphere technique in 10 dogs. Flows were determined before and after an EEV with the animals on cardiopulmonary bypass at controlled perfusion pressures, temperatures, and heart rates. Blood flow was studied at subepicardial and subendocardial levels inside, outside, and bordering the EEV. Prior to performance of the EEV, subepicardial blood flow in the left ventricular myocardium ranged from 0.81 +/- 0.07 to 0.89 +/- 0.08 ml/gm/min. Subendocardial flows ranged from 0.80 +/- 0.07 to 0.91 +/- 0.09 ml/gm/min. There was no significant difference between any of the flows across each respective layer of myocardium. Following the EEV procedure, blood flow to the subendocardium within the EEV fell to 0.33 +/- 0.07 ml/gm/min, while flow to the subendocardium of the normal regions of the same hearts actually increased to 1.21 +/- 0.23 ml/gm/min. Similar changes occurred at subepicardial levels, with flow at the center of the EEV falling to 0.66 +/- 0.10 ml/gm/min despite a tendency for normal subepicardial flow to increase to 1.78 +/- 0.24 ml/gm/min. Superimposed ischemia to the EEV-encompassed myocardium, created by occlusion of the distal left anterior descending coronary artery (LAD), accentuated this abnormality by demonstrating that the region continues to receive some flow from epicardially based coronary vessels. The data from this study show that the EEV decreased regional blood flow to the encompassed myocardium and suggests that myocardial ischemia may be responsible for ablation of the delicate re-entrant mechanisms

  10. Task IV: Development of Circumferential Inlet Distortion through a Representative Eleven Stage High-speed Axial Compressor

    Science.gov (United States)

    Tan, Choon-Sooi; Suder, Kenneth (Technical Monitor)

    2003-01-01

    The concepts and the procedure developed in Task I and Task III were used to determine the response of an eleven-stage high-speed compressor to an inlet distortion of 180 deg. circumferential extent for contrasting against its performance under uniform inlet flow. Using the computed results at the inlet to and outlet of the compressor, the computed total pressure ratio and efficiency for the clean condition are determined to be 14.22 and 76.9 percent respectively. As for the distorted case, these are determined to be 10.35 and 71.8 percent respectively, showing deterioration 76.9 percent vs 71.8 percent). The physical consistency of the computed flow field was assessed as a means of demonstrating the applicability and utility of the body force representation for inlet distortion computations. Specifically the computed evolution of the distorted pattern in static pressure and total pressure from compressor inlet to exit is examined. For the eleven-stage compressor examined here, the deterioration in performance has been found to be particularly severe in the last 2 stages. This suggests that the last two stages could be redesigned to alleviate the observed deterioration thus making the compressor performance insensitive to circumferential inlet distortion. This can potentially be accomplished by first determining what should the body force distribution of the last two stages should be to achieve minimal or no deterioration in performance in the last two stages. One can then in principle proceed to determine the blade design to yield such a body force distribution.

  11. Accelerated circumferential strain quantification of the left ventricle using CIRCOME: simulation and factor analysis

    Science.gov (United States)

    Moghaddam, Abbas N.; Finn, J. Paul

    2008-03-01

    Circumferential strain of the left ventricle reflects myocardial contractility and is considered a key index of cardiac function. It is also an important parameter in the quantitative evaluation of heart failure. Circumferential compression encoding, CIRCOME, is a novel method in cardiac MRI to evaluate this strain non-invasively and quickly. This strain encoding technique avoids the explicit measurement of the displacement field and does not require calculation of strain through spatial differentiation. CIRCOME bypasses these two time-consuming and noise sensitive steps by directly using the frequency domain (k-space) information from radially tagged myocardium, before and after deformation. It uses the ring-shaped crown region of the k-space, generated by the taglines, to reconstruct circumferentially compression-weighted images of the heart before and after deformation. CIRCOME then calculates the circumferential strain through relative changes in the compression level of corresponding regions before and after deformation. This technique can be implemented in 3D as well as 2D and may be employed to estimate the overall global or regional circumferential strain. The main parameters that affect the accuracy of this method are spatial resolution, signal to noise ratio, eccentricity of the center of radial taglines their fading and their density. Also, a variety of possible image reconstruction and filtering options may influence the accuracy of the method. This study describes the pulse sequence, algorithm, influencing factors and limiting criteria for CIRCOME and provides the simulated results.

  12. Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block

    Directory of Open Access Journals (Sweden)

    Zimetbaum Peter J

    2010-01-01

    Full Text Available Abstract Background Cardiac resynchronization therapy (CRT has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR to assess circumferential strain in this population. Methods We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls. Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined. Results Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10 of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 ± 6%, non-LBBB 10 ± 4% vs. healthy 19 ± 4%; both p Conclusions Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

  13. Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications

    Science.gov (United States)

    Bjorkman, Gerry; Cantrell, Mark; Carter, Robert

    2003-01-01

    Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading

  14. An analysis of the Circumferential Grooves Casing Treatment for transonic compressor flow

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.

  15. A second patient with MCA/MR syndrome with multiple circumferential skin creases.

    Science.gov (United States)

    Leonard, N J

    2002-09-15

    Symmetrical congenital circumferential skin creases are a rare feature described in only a few conditions. We report a case of a 29-month-old boy with symmetrical circumferential skin creases on arms, legs, and digits, and other features reminiscent of the single case reported by Cohen et al. [1993: Clin Dysmorphol 2:39-46] and reviewed by Elliott et al. [1996: Am J Med Genet 62:23-25]. The key features also include epicanthic folds, microphthalmia, microcornea, microcephaly, small, low-set posteriorly angulated ears with thick overfolded helices, cleft palate, and moderate-severe psychomotor developmental delay.

  16. Optimization of the axial compressor flow passage to reduce the circumferential distortion

    Science.gov (United States)

    Popov, G.; Kolmakova, D.; Shklovets, A.; Ermakov, A.

    2015-08-01

    This work is motivated by the necessity to reduce the effects of the flow circumferential distortion in the flow passage of the aircraft gas turbine engine (GTE). In previous research, the authors have proposed the approaches to decrease of the flow circumferential distortion arising from the mid-support racks of GTE compressor and having a negative impact on the blade rows, located upstream. In particular, the idea of introducing the circumferentially non-uniform blade pitch and profile stagger angle of guide vanes located in front of the support was contributed in order to redistribute the flow and decrease the dynamic stresses in the rotor wheel of the same stage. During the research presented in this paper, another principal of reduction of the flow circumferential distortion was chosen. Firstly, the variants of upgrading the existing support racks were found. Secondly, the new design of support was offered. Both the first and the second version of the support design variation took into account the availability of technological and structural limitations associated with the location of oil pipes, springs and others elements in the support racks. Investigations of modified design showed that the support with altered racks provides a reduction of dynamic stresses by 20% at resonance with the most dangerous harmonic, and the new design of support can give the decrease of 30%.

  17. Numerical Simulation of the Flow Field in Circumferential Grooved Liquid Seals

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    2013-01-01

    Full Text Available Circumferential grooved liquid seals are utilized inside turbomachinery to provide noncontacting control of internal incompressible fluid leakage. Accurate prediction of the flow field is fundamental in producing robust and efficient designs. To validate the capabilities of the computational fluid dynamics FLUENT for incompressible fluid seal flow, comparisons of velocity parameters are made to the published experimental results and other CFD code for a circumferential grooved liquid seal. This work employs a pressure-based CFD code FLUENT to calculate the flow field in the seal, using four different turbulence models respectively. The velocity contours are compared with experimental values. It shows good overall agreement of the axial, radial, and azimuthal velocities in the through-flow jet, shear layer, and recirculation zone. Quantitative comparisons of velocity profiles at the center of the groove are made to experiment. This study verifies the prediction accuracy of three turbulence models. Various structures were considered to obtain a better understanding of the circumferential grooved liquid flow characteristics. The best groove structure to control leakage was also found within the limited designed seal. This study will provide a useful reference for designing the circumferential grooved liquid seal.

  18. Conventional CT for the prediction of an involved circumferential resection margin in primary rectal cancer

    NARCIS (Netherlands)

    Wolberink, Steven V. R. C.; Beets-Tan, Regina G. H.; de Haas-Kock, Danielle F. M.; Span, Mark M.; van de Jagt, Eric J.; van de Velde, Cornelis J. H.; Wiggers, Theo

    2007-01-01

    Purpose: To determine the accuracy of conventional computed tomography (CT) scan in the preoperative prediction of an involved circumferential resection margin (CRM) in primary rectal cancer. Methods: 125 patients with biopsy-proven adenocarcinoma of the rectum underwent CT of the abdomen before und

  19. Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter.

    Science.gov (United States)

    Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Liang, Kaicheng; Wang, Zhao; Cleveland, Cody; Booth, Lucas; Potsaid, Benjamin; Jayaraman, Vijaysekhar; Cable, Alex E; Mashimo, Hiroshi; Langer, Robert; Traverso, Giovanni; Fujimoto, James G

    2016-08-01

    We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec. Volumetric data consisting of 4200 circumferential images of 5,000 A-scans each over a 2.6 cm length, covering a ~13 cm(2) area is acquired in <18 seconds. A non-rigid image registration algorithm is used to suppress motion artifacts from non-uniform rotational distortion (NURD), cardiac motion or respiration. En face OCT images at various depths can be generated. OCT angiography (OCTA) is computed using intensity decorrelation between sequential pairs of circumferential scans and enables three-dimensional visualization of vasculature. Wide area volumetric OCT and OCTA imaging of the swine esophagus in vivo is demonstrated.

  20. Mechanical characterization of human aortas from pressurization testing and a paradigm shift for circumferential residual stress.

    Science.gov (United States)

    Labrosse, Michel R; Gerson, Eleanor R; Veinot, John P; Beller, Carsten J

    2013-01-01

    Material properties needed for accurate stress analysis of the human aorta are still incompletely known, especially as many reports have ignored the presence of residual stresses in the aortic wall. To contribute new material regarding these issues, we carried out measurements and pressurization testing on ascending, thoracic and abdominal aortic samples from 24 human subjects aged 38-77 years, and evaluated the opening angle describing the circumferential residual stress level present in the aorta. We determined material constants for the aorta by gender, anatomic location and age group, according to a simple phenomenological constitutive model. The unpressurized aortic radius positively correlated with age, and the circumferential and longitudinal stretch ratios under systemic pressure negatively correlated with age, confirming the known enlargement and stiffening of the aorta with aging. The opening angle was measured to range from a minimum of 89° to above 360° for extreme cases. For given aortic dimensions and material properties, analysis of the in vivo circumferential and longitudinal mural stress distributions indicated a profound influence of the opening angle. For instance, in the thoracic aorta of males aged 38-66, opening angles in the range of 0° to 80° (resp. 60°) may equalize the gradient of in vivo circumferential (resp. longitudinal) stress between the inner and outer layers of the aorta, as commonly expected; however, opening angles above 160° (resp. 120°) may cause the gradient of circumferential (resp. longitudinal) stress to reverse and increase compared to the case without residual stress, putting the maximum stresses toward the adventitia instead of the intima. Even though the analysis of the aortic wall excluded possible longitudinal residual stresses as well as material inhomogeneities, such as constitutive differences between the intimal, medial and adventitial layers, the experimental data reported herein are important to aortic

  1. Endocardial-epicardial distribution of myocardial perfusion reserve assessed by multidetector computed tomography in symptomatic patients without significant coronary artery disease

    DEFF Research Database (Denmark)

    Kühl, Jørgen Tobias; George, Richard T; Mehra, Vishal C

    2016-01-01

    (MPR) in humans. We aimed to test the hypothesis that MPR in all myocardial layers is determined by age, gender, and cardiovascular risk profile in patients with ischaemic symptoms or equivalent but without obstructive coronary artery disease (CAD). METHODS AND RESULTS: A total of 149 patients enrolled...... in endocardial-epicardial distribution of perfusion reserve may be demonstrated with static CT perfusion. Low MPR in all myocardial layers was observed specifically in obese patients....

  2. Skin resurfacing in a circumferential full thickness burn to the penis: lessons learnt.

    Science.gov (United States)

    Jabir, Shehab; Frew, Quentin; Thompson, Richard; Dziewulski, Peter

    2013-08-13

    A circumferential full-thickness burn to the penis is a rarely encountered injury. However, when it does occur, it proves a management challenge to the plastic and burns surgeon in terms of reconstruction. This is due to the need of not only regaining adequate function of the organ, but also because of the need for a pleasing aesthetic outcome. Split-skin grafts have been utilised successfully to resurface full thickness burns of the penis and have given good results. Yet the success of split-skin grafts, especially those applied to an anatomically challenging region of the body such as the penis, depends on a number of carefully thought-out steps. We discuss the case of a circumferential full-thickness burn to the penis which was treated with split-skin grafting and highlight important pitfalls that the plastic and burns surgeon need to be aware of to ensure a successful outcome.

  3. Prediction of leakage and rotordynamic coefficients for the circumferential-groove pump seal using CFD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Ha, Tae Woong [Gachon University, Seongnam (Korea, Republic of)

    2016-05-15

    The circumferential-groove seal is commonly used in various turbopumps to reduce leakage. The main goal of this paper is to develop the method of three-dimensional CFD analysis for determining leakage and rotordynamic coefficients of the circumferential-groovepump seal. A relative coordinate system was defined for steady-state simulation to calculate the velocity and pressure distributions of the seal clearance at each rotor whirl speed. Instead of setting the inlet and outlet pressures as the boundary conditions in the three dimensional CFD analysis, as it is more commonly done, we used the inlet velocity and outlet pressure obtained from a preliminary two dimensional CFD analysis. For prediction leakage, the presented analysis shows improvement from the bulk-flow model analysis. For the prediction of rotordynamic coefficients of K, k and C, the presented analysis provides results in closer agreement with the experimental values than those of the bulk-flow model analysis at several rotor speeds.

  4. Circumferential mucosal dissection and esophageal perforation in a patient with eosinophilic esophagitis

    Institute of Scientific and Technical Information of China (English)

    Gennaro Liguori; Maurizio Cortale; Fabrizio Cimino; Michele Sozzi

    2008-01-01

    A young man with a previous history of episodes of mild solid food dysphagia was admitted with a total dysphagia.The esophagogastroduodenoscopy (EGDS) showed an extensive disruption of mucosal layer with a cul-de-sac in the lower part of the esophagus.Soon after the procedure,the patient suffered from an acute chest pain and subsequent CT scan demonstrated an intramural circumferential dissection of thoracic esophagus,and a mediastinal emphysema.An emergency right thoracotomy was performed,followed by a total esophagectomy with esophagogastroplasty and jejunostomy.The histopathology confirmed that mucosal and submucosal layers were circumferentially detached from muscular wall and showed an eosinophilic infiltration of the whole organ with necrosis and erosions of mucosal,submucosal and muscular layers.The diagnosis was esophageal perforation in eosinophilic esophagitis.

  5. [Echocardiographic longitudinal, radial, circumferential and rotational synchronization disturbance in predicting response to cardiac resynchronization therapy].

    Science.gov (United States)

    Sade, Leyla Elif

    2010-02-01

    Several echocardiographic methods have been proposed to assist patient selection for cardiac resynchronization therapy. Color-coded tissue Doppler is one of the most promising methods to quantify mechanical dyssynchrony. However, tissue Doppler data are affected by Doppler angle of incidence and tethering or translational motion. Furthermore tissue Doppler based modalities are good for longitudinal motion analysis but limited in other directions of wall motion such as radial, circumferential, and rotational. Speckle tracking is a more recent technique that allows accurate calculation of regional radial and circumferential strain as well as regional rotation for dyssynchrony analysis. Although no ideal echocardiographic method exists that integrates regional dyssynchrony data in all contraction directions as yet, technical refinements and advances in understanding of pathophysiology will help to improve the study of mechanical dyssynchrony.

  6. Inspection of circumferential IGA/SCC in Bruce Unit 4 SGs

    Energy Technology Data Exchange (ETDEWEB)

    Fluit, S.; Myderwyk, H.; King, P. [Babcock and Wilcox Canada Limited, Cambridge, Ontario (Canada); Durance, D.; Sedman, K. [Bruce Power, Tiverton, Ontario (Canada)

    2008-07-01

    Circumferential IGA/SCC has been detected in the roll-transition zone of tubes in Bruce A SGs for over a decade, but recently became more pronounced in Unit 4 BO4 in 2006 and the spring of 2007. A number of ET probes have been developed to detect and characterize this degradation, including C-3/8, +Point and X-Probe. Comparisons of the inspection results from these probes and metallurgical results from removed tubes have provided insight into the strengths and limitations of each probe and how the probes can complement each other. This paper will discuss the evolution of the ET inspection approach for circumferential IGA/SCC and how the results have been used in recent FFS assessments in the Bruce Unit 4 SGs. (author)

  7. In vivo vascular wall shear rate and circumferential strain of renal disease patients.

    Science.gov (United States)

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-02-01

    This study measures the vascular wall shear rate at the vessel edge using decorrelation based ultrasound speckle tracking. Results for nine healthy and eight renal disease subjects are presented. Additionally, the vascular wall shear rate and circumferential strain during physiologic pressure, pressure equalization and hyperemia are compared for five healthy and three renal disease subjects. The mean and maximum wall shear rates were measured during the cardiac cycle at the top and bottom wall edges. The healthy subjects had significantly higher mean and maximum vascular wall shear rate than the renal disease subjects. The key findings of this research were that the mean vascular wall shear rates and circumferential strain changes between physiologic pressure and hyperemia that was significantly different between healthy and renal disease subjects.

  8. Influence of the heart rate on mean circumferential shortening velocity: echocardiographic study of 183 normal subjects.

    Science.gov (United States)

    Mangiarotti, R; Martinotti, R; Monzani, V; Sardella, F; Pierini, A; Pastori, M; Randazzo, A

    1986-01-01

    Echocardiography was used to explore the influence of independent variables (age, body surface area and heart rate) on the mean circumferential shortening velocity (MVCF) in 183 healthy subjects. Multiple stepwise regression analysis shows that heart rate is the only variable of the three just mentioned that influences MVCF. A regression equation is evolved and proposed as an index of MVCF correction for varying heart rates.

  9. Selective radiofrequency therapy as a non-invasive approach for contactless body contouring and circumferential reduction.

    Science.gov (United States)

    Fajkošová, Kateřina; Machovcová, Alena; Onder, Meltem; Fritz, Klaus

    2014-03-01

    In this study, the efficacy of non-contact, selective radiofrequency (RF) were evaluated for body contouring as non-invasive fat and circumferential reduction of the abdomen. 40 healthy (36 female, 4 male) subjects showing significant volume of subcutaneous fat tissue on the abdomen and waistline were included. Once a week for 30 minutes, 4 sessions were performed. The applicator was placed on a supplied spacer covering the treatment area. Maximum power was 200W, which induced heat in the fat and connective tissue layer. The homogeneity of heat distribution and temperature of the skin surface were controlled. The circumferential reduction was measured at the baseline and after the last treatment. The photographs and adverse effects were recorded. Participants completed the self-evaluation questionnaires and rated their level of satisfaction. All subjects tolerated the treatments well. The only side effect was mild to moderate erythema. 35 subjects finished the protocol as planned and 5 subjects dropped off due to events not related to the study. 32 subjects had a 1-13 cm decrease in abdominal circumference and 3 subjects did not show significant response (0-1 cm). Most likely, a very thin fat layer was the reason for lack of response (the non-responding group was the thinnest patient group). No significant differences were found between men and women. The average decrease of 4.93 cm was calculated as a result of circumferential reduction statistical evidence. This study demonstrates that the selective RF system designed for contactless deep tissue heating is a painless, safe, and effective treatment for non-surgical body contouring and circumferential fat reduction.

  10. Numerical Investigation of Inlet Distortion on an Axial Flow Compressor Rotor with Circumferential Groove Casing Treatment

    Institute of Scientific and Technical Information of China (English)

    Huang Jian; Wu Hu

    2008-01-01

    On the base of an assumed steady inlet circumferential total pressure distortion, three-dimensional time-dependent numerical simulations are conducted on an axial flow subsonic compressor rotor. The performances and flow fields of a compressor rotor, either casing treated or untreated, are investigated in detail either with or without inlet pressure distortion. Results show that the circumferential groove casing treatment can expand the operating range of the compressor rotor either with or without inlet pressure distortion at the expense of a drop in peak isentropic efficiency. The casing treatment is capable of weakening or even removing the tip leakage vortex effectively either with or without inlet distortion. In clean inlet circumstances, the enhancement and forward movement of tip leakage vortex cause the untreated compressor rotor to stall. By contrast, with circumferential groove casing, the serious flow separation on the suction surface leads to aerodynamic stalling eventually. In the presence of inlet pressure distortion, the blade loading changes from passage to passage as the distorted inflow sector is traversed. Similar to the clean inlet circumstances, with a smooth wall casing, the enhancement and forward movement of tip leakage vortex are still the main factors which lead to the compressor rotor stalling eventu-ally. When the rotor works under near stall conditions, the blockage resulting from the tip leakage vortex in all the passages is very seri-ous. Especially in several passages, flow-spillage is observed. Compared to the clean inlet circumstances, circumferential groove casing treatment can also eliminate the low energy zone in the outer end wall region effectively.

  11. Circumferential-wave phase velocities for empty, fluid-immersed spherical metal shells

    DEFF Research Database (Denmark)

    Überall, Herbert; Ahyi, A. C.; Raju, P. K.

    2002-01-01

    -loaded, evacuated spherical metal shells of aluminum, stainless steel, and tungsten carbide. In particular, the characteristic upturn of the dispersion curves of low-order shell-borne circumferential waves (A or A0 waves) which takes place on spherical shells when the frequency tends towards very low values......, is demonstrated here for all cases of the metals under consideration. ©2002 Acoustical Society of America....

  12. Mmp15 is a direct target of Snai1 during endothelial to mesenchymal transformation and endocardial cushion development.

    Science.gov (United States)

    Tao, Ge; Levay, Agata K; Gridley, Thomas; Lincoln, Joy

    2011-11-15

    Cardiac valves originate from endocardial cushions (EC) formed by endothelial-to-mesenchymal transformation (EMT) during embryogenesis. The zinc-finger transcription factor Snai1 has previously been reported to be important for EMT during organogenesis, yet its role in early valve development has not been directly examined. In this study we show that Snai1 is highly expressed in endothelial, and newly transformed mesenchyme cells during EC development. Mice with targeted snai1 knockdown display hypocellular ECs at E10.5 associated with decreased expression of mesenchyme cell markers and downregulation of the matrix metalloproteinase (mmp) family member, mmp15. Snai1 overexpression studies in atrioventricular canal collagen I gel explants indicate that Snai1 is sufficient to promote mmp15 expression, cell transformation, and mesenchymal cell migration and invasion. However, treatment with the catalytically active form of MMP15 promotes cell motility, and not transformation. Further, we show that Snai1-mediated cell migration requires MMP activity, and caMMP15 treatment rescues attenuated migration defects observed in murine ECs following snai1 knockdown. Together, findings from this study reveal previously unappreciated mechanisms of Snai1 for the direct regulation of MMPs during EC development.

  13. Nonlinear vibrations and energy exchange of single-walled carbon nanotubes. Circumferential flexural modes

    Science.gov (United States)

    Strozzi, Matteo; Smirnov, Valeri V.; Manevitch, Leonid I.; Milani, Massimo; Pellicano, Francesco

    2016-10-01

    In this paper, the nonlinear vibrations and energy exchange of single-walled carbon nanotubes (SWNTs) are studied. The Sanders-Koiter theory is applied to model the nonlinear dynamics of the system in the case of finite amplitude of vibration. The SWNT deformation is described in terms of longitudinal, circumferential and radial displacement fields. Simply supported, clamped and free boundary conditions are considered. The circumferential flexural modes (CFMs) are investigated. Two different approaches based on numerical and analytical models are compared. In the numerical model, an energy method based on the Lagrange equations is used to reduce the nonlinear partial differential equations of motion to a set of nonlinear ordinary differential equations, which is solved by using the implicit Runge-Kutta numerical method. In the analytical model, a reduced form of the Sanders-Koiter theory assuming small circumferential and tangential shear deformations is used to get the nonlinear ordinary differential equations of motion, which are solved by using the multiple scales analytical method. The transition from energy beating to energy localization in the nonlinear field is studied. The effect of the aspect ratio on the analytical and numerical values of the nonlinear energy localization threshold for different boundary conditions is investigated. Time evolution of the total energy distribution along the axis of a simply supported SWNT

  14. Circumferential phased array of shear-horizontal wave magnetostrictive patch transducers for pipe inspection.

    Science.gov (United States)

    Kim, Hoe Woong; Lee, Joo Kyung; Kim, Yoon Young

    2013-02-01

    Several investigations report effective uses of magnetostrictive patch transducers to generate and measure longitudinal and torsional guided waves in a pipe. They can be used to form a phased array for the circumferential inspection of pipes. Although there are circumferential phased arrays employing piezoelectric transducers or EMAT's, no magnetostrictive patch transducer based array system has been attempted. In this investigation, we aim to develop a circumferential phased magnetostrictive patch transducer (PMPT) array that can focus shear-horizontal waves at any target point on a cylindrical surface of a pipe. For the development, a specific configuration of a PMPT array employing six magnetostrictive patch transducers is proposed. A wave simulation model is also developed to determine time delays and amplitudes of signals generated by the transducers of the array. This model should be able to predict accurately the angular profiles of shear-horizontal waves generated by the transducers. For wave focusing, the time reversal idea will be utilized. The wave focusing ability of the developed PMPT array is tested with multiple-crack detection experiments. Imaging of localized surface inspection regions is also attempted by using wave signals measured by the developed PMPT array system.

  15. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    Directory of Open Access Journals (Sweden)

    Qing Wei Li

    2015-01-01

    Full Text Available A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by the finite element method. At last, the oxide scale thickness and stress sensors are established on support vector machine (SMV optimized by particle swarm optimization (PSO with time and circumferential angles as inputs and oxide scale thickness and stress as outputs. Temperature and stress calculation methods are validated by the operation data and experimental data, respectively. The soft sensor is applied to the superheater tubes of some power plant. Results show that the soft sensor can give enough accurate results for oxide scale thickness and stress in reasonable time. The forecasting model provides a convenient way for the research of the oxide scale failure.

  16. Lumbar extracavitary corpectomy with a single stage circumferential arthrodesis: surgical technique and clinical series.

    Science.gov (United States)

    Singh, Kern; Park, Daniel K

    2012-07-01

    Circumferential arthrodesis and reconstruction is necessary after a lumbar corpectomy in the setting of malignancy and infection. The advent of expandable cage technology now allows for safe anterior column reconstruction via a posterior approach with no transection and minimal retraction of the lumbar spinal nerve roots. Fifteen patients underwent a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach. Posterior segmental pedicle screw fixation and iliac crest bone graft was used in all cases. Fifteen lumbar extracavitary corpectomy nerve root-sparing procedures have been performed to date, with at least 1-year follow-up (12 tumors/3 infections). No patient suffered any neurological complications. One patient suffered from a postoperative myocardial infarction 10 days after the procedure. Two patients had medical complications that were treated without sequelae. We present a technical description and case series of patients undergoing a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach with at least 1-year follow-up. The technique is safe, technically feasible, and obviates an anterior approach in this oftentimes critically ill patient population.

  17. Functional evaluation of repairs to circumferential labral lesions of the glenoid - Case series

    Directory of Open Access Journals (Sweden)

    Alexandre Tadeu do Nascimento

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the clinical results among patients undergoing arthroscopic repair of circumferential labral lesions. METHODS: This was a retrospective study on 10 patients who underwent arthroscopic repair to circumferential labral lesions of the shoulder, between September 2012 and September 2015. The patients were evaluated by means of the Carter-Rowe score, DASH score, UCLA score, visual analog scale (VAS for pain and Short-Form 36 (SF36. The average age at surgery was 29.6 years. The mean follow-up was 27.44 months (range: 12-41.3. RESULTS: The mean score was 16 points for DASH; 32 points for UCLA, among which six patients (60% had excellent results, three (30% good and one (10% poor; 1.8 points for VAS, among which nine patients (90% had minor pain and one (10% moderate pain; 79.47 for SF-36; and 92.5 for Carter-Rowe, among which nine patients (90% had excellent results and one (10% good. Joint degeneration was present in one case (10%, of grade 1. We did not observe any significant complications, except for grade 1 glenohumeral arthrosis, which one patient developed after the operation. CONCLUSION: Arthroscopic repair of circumferential labral lesions of the shoulder through use of absorbable anchors is effective, with improvements in all scores applied, and it presents low complication rates. Cases associated with glenohumeral dislocation have lower long-term residual pain.

  18. Numerical Simulation for Three-Dimensional (3D) Unsteady State Temperature Field in Circumferential Laser Oxygen Cutting of Pipes

    Institute of Scientific and Technical Information of China (English)

    Kaijin HUANG; Dawen ZENG; Changsheng XIE; Desheng XU

    2003-01-01

    A 3D unsteady state numerical model of heat transfer in the circumferential laser oxygen cutting of pipes wasdeveloped. In order to minimize the computing time required for solving the finite difference equations as much aspossible, the alternating direct

  19. On guided circumferential waves in soft electroactive tubes under radially inhomogeneous biasing fields

    Science.gov (United States)

    Wu, Bin; Su, Yipin; Chen, Weiqiu; Zhang, Chuanzeng

    2017-02-01

    Soft electroactive (EA) tube actuators and many other cylindrical devices have been proposed recently in literature, which show great advantages over those made from conventional hard solid materials. However, their practical applications may be limited because these soft EA devices are prone to various failure modes. In this paper, we present an analysis of the guided circumferential elastic waves in soft EA tube actuators, which has potential applications in the in-situ nondestructive evaluation (NDE) or online structural health monitoring (SHM) to detect structural defects or fatigue cracks in soft EA tube actuators and in the self-sensing of soft EA tube actuators based on the concept of guided circumferential elastic waves. Both circumferential SH and Lamb-type waves in an incompressible soft EA cylindrical tube under inhomogeneous biasing fields are considered. The biasing fields, induced by the application of an electric voltage difference to the electrodes on the inner and outer cylindrical surfaces of the EA tube in addition to an axial pre-stretch, are inhomogeneous in the radial direction. Dorfmann and Ogden's theory of nonlinear electroelasticity and the associated linear theory for small incremental motion constitute the basis of our analysis. By means of the state-space formalism for the incremental wave motion along with the approximate laminate technique, dispersion relations are derived in a particularly efficient way. For a neo-Hookean ideal dielectric model, the proposed approach is first validated numerically. Numerical examples are then given to show that the guided circumferential wave propagation characteristics are significantly affected by the inhomogeneous biasing fields and the geometrical parameters. Some particular phenomena such as the frequency veering and the nonlinear dependence of the phase velocity on the radial electric voltage are discussed. Our numerical findings demonstrate that it is feasible to use guided circumferential

  20. Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis

    Science.gov (United States)

    Skovrlj, Branko; Guzman, Javier Z.; Caridi, John; Cho, Samuel K.

    2015-01-01

    Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach. PMID:26835214

  1. Investigations on an Axial Flow Fan Stage subjected to Circumferential Inlet Flow Distortion and Swirl

    Institute of Scientific and Technical Information of China (English)

    M.Govardhan; K.Viswanath

    1997-01-01

    The combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage are reported in this paper,The study involves measurements at the inlet of the rotor and exit of the rotor and stator atdesign and off design flow conditions.The study indicated that at the design flow condition,swirl had caused deterioration of the performance in addition to that caused by distortion.Pressure rise imparted in the distortion zone is hogher than in the free zone.The attenuation of distortion is high in the presence of swirl.

  2. The thermal effect at the distal pole of the endocardial electrodes of the pacemaker in electrosurgical treatment. The risk heart's damage

    Directory of Open Access Journals (Sweden)

    Fedotov N. M.

    2012-12-01

    Conclusion. A thermal effect was observed during electrosurgical intervention in the tissue around the distal pole of the pacemaker endocardial electrodes that depends on the location of the pacing system in relation to the electrodes of electrocoagulator, power and duration of exposure. Clinical signs of the thermal effect were non-effective pacing, supraventricular and ventricular rhythm disturbances and primarily due to the violation of safety standards for electrosurgical procedures. The clinical significance of this effect is minimal when the suggested principles are adhered to and the pacing system is placed out of the lines of force of the electric field.

  3. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  4. Estimation of leak rate through circumferential cracks in pipes in nuclear power plants

    Directory of Open Access Journals (Sweden)

    Jai Hak Park

    2015-04-01

    Full Text Available The leak before break (LBB concept is widely used in designing pipe lines in nuclear power plants. According to the concept, the amount of leaking liquid from a pipe should be more than the minimum detectable leak rate of a leak detection system before catastrophic failure occurs. Therefore, accurate estimation of the leak rate is important to evaluate the validity of the LBB concept in pipe line design. In this paper, a program was developed to estimate the leak rate through circumferential cracks in pipes in nuclear power plants using the Henry–Fauske flow model and modified Henry–Fauske flow model. By using the developed program, the leak rate was calculated for a circumferential crack in a sample pipe, and the effect of the flow model on the leak rate was examined. Treating the crack morphology parameters as random variables, the statistical behavior of the leak rate was also examined. As a result, it was found that the crack morphology parameters have a strong effect on the leak rate and the statistical behavior of the leak rate can be simulated using normally distributed crack morphology parameters.

  5. Mutations in Either TUBB or MAPRE2 Cause Circumferential Skin Creases Kunze Type

    Science.gov (United States)

    Isrie, Mala; Breuss, Martin; Tian, Guoling; Hansen, Andi Harley; Cristofoli, Francesca; Morandell, Jasmin; Kupchinsky, Zachari A.; Sifrim, Alejandro; Rodriguez-Rodriguez, Celia Maria; Dapena, Elena Porta; Doonanco, Kurston; Leonard, Norma; Tinsa, Faten; Moortgat, Stéphanie; Ulucan, Hakan; Koparir, Erkan; Karaca, Ender; Katsanis, Nicholas; Marton, Valeria; Vermeesch, Joris Robert; Davis, Erica E.; Cowan, Nicholas J.; Keays, David Anthony; Van Esch, Hilde

    2015-01-01

    Circumferential skin creases Kunze type (CSC-KT) is a specific congenital entity with an unknown genetic cause. The disease phenotype comprises characteristic circumferential skin creases accompanied by intellectual disability, a cleft palate, short stature, and dysmorphic features. Here, we report that mutations in either MAPRE2 or TUBB underlie the genetic origin of this syndrome. MAPRE2 encodes a member of the microtubule end-binding family of proteins that bind to the guanosine triphosphate cap at growing microtubule plus ends, and TUBB encodes a β-tubulin isotype that is expressed abundantly in the developing brain. Functional analyses of the TUBB mutants show multiple defects in the chaperone-dependent tubulin heterodimer folding and assembly pathway that leads to a compromised yield of native heterodimers. The TUBB mutations also have an impact on microtubule dynamics. For MAPRE2, we show that the mutations result in enhanced MAPRE2 binding to microtubules, implying an increased dwell time at microtubule plus ends. Further, in vivo analysis of MAPRE2 mutations in a zebrafish model of craniofacial development shows that the variants most likely perturb the patterning of branchial arches, either through excessive activity (under a recessive paradigm) or through haploinsufficiency (dominant de novo paradigm). Taken together, our data add CSC-KT to the growing list of tubulinopathies and highlight how multiple inheritance paradigms can affect dosage-sensitive biological systems so as to result in the same clinical defect. PMID:26637975

  6. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M. [and others

    1996-12-01

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

  7. Experimental investigation on circumferential and axial temperature gradient over fuel channel under LOCA

    Science.gov (United States)

    Yadav, Ashwini Kumar; kumar, Ravi; Gupta, Akhilesh; Chatterjee, Barun; Mukhopadhyay, Deb; Lele, H. G.

    2014-06-01

    In a nuclear reactor temperature rises drastically in fuel channels under loss of coolant accident due to failure of primary heat transportation system. Present investigation has been carried out to capture circumferential and axial temperature gradients during fully and partially voiding conditions in a fuel channel using 19 pin fuel element simulator. A series of experiments were carried out by supplying power to outer, middle and center rods of 19 pin fuel simulator in ratio of 1.4:1.1:1. The temperature at upper periphery of pressure tube (PT) was slightly higher than at bottom due to increase in local equivalent thermal conductivity from top to bottom of PT. To simulate fully voided conditions PT was pressurized at 2.0 MPa pressure with 17.5 kW power injection. Ballooning initiated from center and then propagates towards the ends and hence axial temperature difference has been observed along the length of PT. For asymmetric heating, upper eight rods of fuel simulator were activated and temperature difference up-to 250 °C has been observed from top to bottom periphery of PT. Such situation creates steep circumferential temperature gradient over PT and could lead to breaching of PT under high pressure.

  8. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    Directory of Open Access Journals (Sweden)

    Amy Y Hsiao

    Full Text Available The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  9. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    Science.gov (United States)

    Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  10. Recent evaluations of crack-opening-area in circumferentially cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

    1997-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

  11. Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

    Science.gov (United States)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

  12. Effects of inlet circumferential fluctuation on the sweep aerodynamic performance of axial fans/compressors

    Science.gov (United States)

    Gui, Xingmin; Zhu, Fang; Wan, Ke; Jin, Donghai

    2013-10-01

    Swept blades have been widely used in the transonic fan/compressor of aircraft engines with the aids of 3D CFD simulation since the design concept of controlling the shock structure was firstly proposed and successfully tested by Dr. Wennerstrom in the 1980s. However, some disadvantage phenomenon has also been induced by excessively 3D blade geometries on the structure stress insufficiency, vibration and reliability. Much confusion in the procedure of design practice leading us to recognize a new view on the flow mechanism of sweep aerodynamical induction: the new radial equilibrium established by the influence of inlet circumferential fluctuation (CF) changes the inlet flows of blading and induces the performance modification of axial fans/compressors blade. The view is verified by simplified models through numerical simulation and circumferentially averaged analysis in the present paper. The results show that the CF source items which originate from design parameters, such as the spanwise distributions of the loading and blading geometries, contribute to the changing of averaged incidence spanwise distribution, and further more affect the performance of axial fans/compressors with swept blades.

  13. Effects of circumferential rigid wrist orthoses in rehabilitation of patients with radius fracture at typical site

    Directory of Open Access Journals (Sweden)

    Đurović Aleksandar

    2005-01-01

    Full Text Available Background. The use of orthoses is a questionable rehabilitation method for patients with the distal radius fracture at typical site. The aim of this study was to compare the effects of the rehabilitation on patients with radius fracture at the typical site, who wore circumferential static wrist orthoses, with those who did not wear them. Methods. Thirty patients were divided into 3 equal groups, 2 experimental groups, and 1 control group. The patients in the experimental groups were given the rehabilitation program of wearing serially manufactured (off-the-shelf, as well as custom-fit orthoses. Those in the control group did not wear wrist orthoses. Evaluation parameters were pain, edema, the range of the wrist motion, the quality of cylindrical, spherical, and pinch-spherical grasp, the strength of pinch and hand grasp, and patient's assessment of the effects of rehabilitation. Results. No significant difference in the effects of rehabilitation on the patients in experimental groups as opposed to control group was found. Patients in the first experimental group, and in control group were more satisfied with the effects of rehabilitation, as opposed to the patients in the second experimental group (p<0,05. Conclusion. The effects of circumferential static wrist orthoses in the rehabilitation of patients with distal radius fracture at the typical site were not clinically significant. There was no significant difference between the custom and off-the-shelf orthoses.

  14. COMPUTATIONAL AND EXPERIMENTAL STUDY ON TIP LEAKAGE VORTEX OF CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    LI Yang; OUYANG Hua; DU Zhaohui

    2007-01-01

    In the steady operation condition, the experiments and the numerical simulations are used to investigate the tip leakage flow fields in three low pressure axial flow fans with three kinds of circumferential skewed rotors, including the radial rotor, the forward-skewed rotor and the backward-skewed rotor. The three-dimensional viscous flow fields of the fans are computed. In the experiments, the two-dimensional plane particle image velocimetry (PIV) system is used to measure the flow fields in the tip region of three different pitchwise positions of each fan. The results show that the computational results agree well with the experimental data in the flow field of the tip region of each fan. The tip leakage vortex core segments based on method of the eigenmode analysis can display clearly some characteristics of the tip leakage vortex, such as the origination position of tip leakage vortex, the development of vortex strength, and so on. Compared with the radial rotor, the other two skewed rotors can increase the stability of the tip leakage vortex and the increment in the forward-skewed rotor is more than that in the backward-skewed one. Among the tip leakage vortices of the three rotors, the velocity of the vortex in the forward-skewed rotor is the highest in the circumferential direction and the lowest in the axial direction.

  15. Combined Right Ventricular Outflow Tract Epicardial and Endocardial Late Potential Ablation for Treatment of Brugada Storm: A Case Report and Review of the Literature.

    Science.gov (United States)

    Saha, Sandeep A; Krishnan, Kousik; Madias, Christopher; Trohman, Richard G

    2016-12-01

    A 34-year-old man with Brugada syndrome (BrS) presented with electrical storm, manifested as multiple appropriate shocks from his implantable cardioverter-defibrillator over a period of 7 hours. He had not tolerated prior treatment with quinidine, and had self-discontinued cilostazol citing persistent palpitations. After stabilization with intravenous isoproterenol, an electrophysiology study was performed but no spontaneous or induced ventricular ectopic beats were identified. A three-dimensional (3D) endocardial electro-anatomic map of the right ventricular outflow tract (RVOT), pulmonic valve, and pulmonary artery, as well as a 3D epicardial map of the RVOT, were created. Low voltage, complex, fractionated electrograms and late potentials were targeted for irrigated radiofrequency ablation both endocardially and epicardially. Post-procedure, he was maintained on cilostazol (referring clinician preference), and has had no further ventricular tachyarrhythmia episodes over the past forty-one months. We propose that this novel ablation strategy may be useful for acute management of selected patients with BrS.

  16. Reduction of longitudinal axial residual stresses in near-root region of circumferential joint of steam pipeline in technological way

    Directory of Open Access Journals (Sweden)

    V. M. Prokhorenko

    2013-10-01

    Full Text Available The paper proposes a variant for solving the problem of reduction of longitudinal residual stresses in near-root region of a circumferential welded joint of section of steam pipeline by FEM simulation of the stress-strain state of repaired section of a circumferential weld in the zone of lack of root penetration on a thin-wall shell of 89 mm diameter and 6 mm wall thickness from steel 20. The result of solving the problem is total distribution of stresses and residual plastic deformations in the repaired zone.

  17. Tip clearance flow interaction with circumferential groove casing treatment in a transonic axial compressor

    Science.gov (United States)

    Ross, Mark Hamilton

    Experimental and computational studies were conducted to study the role of the tip leakage flow in axial compressor stall and the relationship between the tip clearance flow flow field and surge margin extension from circumferential groove casing treatment. The CFD results were used to identify the existence of an interface between the approach ow and the tip-leakage flow. The experiments used a surface streaking visualization method to identify the time-averaged location of this interface as a line of zero axial shear stress at the casing. The axial position of this line, denoted xzs, moved upstream with decreasing ow coefficient in both the experiments and computations. The line was consistently located at the rotor leading edge plane at the stalling flow coefficient, regardless of in flow boundary condition. These results were successfully modeled using a control volume approach that balanced the reverse axial momentum ux of the tip-leakage flow with the momentum flux of the approach fluid. Non-uniform tip clearance measurements demonstrated that movement of the interface upstream of the rotor leading edge plane leads to the generation of short length scale rotating disturbances. Therefore, stall was interpreted as a critical point in the momentum flux balance of the approach ow and the reverse axial momentum flux of the tip-leakage flow. Experimental measurements of surge margin extension from seven CGCT configurations with a fixed groove geometry demonstrated that the contribution of individual grooves in a multi-groove casing to surge margin extension is an (a) additive and (b) linear function of the smooth wall tip clearance axial momentum ux at the location of a each groove. Extending the axial momentum model to include the in uence of a CGCT showed that circumferential grooves reduce the tip leakage flow axial momentum through radial transport. The equivalent force due to a circumferential groove was demonstrated to be related to the smooth wall tip

  18. Endocardial and pericardial disease

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920664 Serious complications and potentialdanger of endomyocardial biopsy.QUNailu (曲乃路), et al. Cardiovascular Dept,Dalian Centr Hosp, Dalian. Chin Cir J1992; 7(3): 257-258. Endomyocardial biopsy(EMB)of 86 patients,aged 15-57 yrs; has been prerformed in this

  19. Endocardial and pericardial disease

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970308 Study on the mechanism of effect ofangiotensin converting enzyme inhibitor on renin-angiotensin system while undergoing bicycle exercisetest. WU Shendi(吴顺娣), et al. Shanghai Hyperten-sive Instit, Ruijin Hosp, 2nd Med Univ, Shanghai,200025. Acta Univ Med 2nd Shanghai 1997; 17(2); 81

  20. Propagation of S-polarized surface polaritons circumferentially around a locally cylindrical surface

    Energy Technology Data Exchange (ETDEWEB)

    Polanco, J. [Department of Physics, University of Texas, El Paso, TX 79968 (United States); Fitzgerald, R.M., E-mail: rfitzgerald@utep.edu [Department of Physics, University of Texas, El Paso, TX 79968 (United States); Maradudin, A.A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

    2012-04-02

    The dispersion relation is derived and solved for s-polarized surface polaritons propagating circumferentially around a portion of a cylindrical interface between vacuum and an isotropic dielectric. In the case that the dielectric is convex toward the vacuum these modes are found to be radiative, and consequently are attenuated as they propagate on the cylindrical surface. When the dielectric is concave toward the vacuum the resulting surface polaritons are nonradiative and propagate unattenuated on the cylinder. Such modes do not exist in the case of a planar interface between a homogeneous isotropic dielectric and vacuum. -- Highlights: ► New surface wave. ► Many-branched dispersion curve. ► More nodes in fields as frequency grows.

  1. Crack shape developments and leak rates for circumferential complex-cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brickstad, B.; Bergman, M. [SAQ Inspection Ltd., Stockholm (Sweden)

    1997-04-01

    A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

  2. Circumferential resonance modes of solid elastic cylinders excited by obliquely incident acoustic waves.

    Science.gov (United States)

    Fan, Ying; Honarvar, Farhang; Sinclair, Anthony N; Jafari, Mohammad-Reza

    2003-01-01

    When an immersed solid elastic cylinder is insonified by an obliquely incident plane acoustic wave, some of the resonance modes of the cylinder are excited. These modes are directly related to the incidence angle of the insonifying wave. In this paper, the circumferential resonance modes of such immersed elastic cylinders are studied over a large range of incidence angles and frequencies and physical explanations are presented for singular features of the frequency-incidence angle plots. These features include the pairing of one axially guided mode with each transverse whispering gallery mode, the appearance of an anomalous pseudo-Rayleigh in the cylinder at incidence angles greater than the Rayleigh angle, and distortional effects of the longitudinal whispering gallery modes on the entire resonance spectrum of the cylinder. The physical explanations are derived from Resonance Scattering Theory (RST), which is employed to determine the interior displacement field of the cylinder and its dependence on insonification angle.

  3. Amniotic membrane grafts for the prevention of esophageal stricture after circumferential endoscopic submucosal dissection.

    Directory of Open Access Journals (Sweden)

    Maximilien Barret

    Full Text Available The prevention of esophageal strictures following circumferential mucosal resection remains a major clinical challenge. Human amniotic membrane (AM is an easily available material, which is widely used in ophthalmology due to its wound healing, anti-inflammatory and anti-fibrotic properties. We studied the effect of AM grafts in the prevention of esophageal stricture after endoscopic submucosal dissection (ESD in a swine model.In this prospective, randomized controlled trial, 20 swine underwent a 5 cm-long circumferential ESD of the lower esophagus. In the AM Group (n = 10, amniotic membrane grafts were placed on esophageal stents; a subgroup of 5 swine (AM 1 group was sacrificed on day 14, whereas the other 5 animals (AM 2 group were kept alive. The esophageal stent (ES group (n = 5 had ES placement alone after ESD. Another 5 animals served as a control group with only ESD.The prevalence of symptomatic strictures at day 14 was significantly reduced in the AM group and ES groups vs. the control group (33%, 40% and 100%, respectively, p = 0.03; mean esophageal diameter was 5.8±3.6 mm, 6.8±3.3 mm, and 2.6±1.7 mm for AM, ES, and control groups, respectively. Median (range esophageal fibrosis thickness was 0.87 mm (0.78-1.72, 1.19 mm (0.28-1.95, and 1.65 mm (0.7-1.79 for AM 1, ES, and control groups, respectively. All animals had developed esophageal strictures by day 35.The anti-fibrotic effect of AM on esophageal wound healing after ESD delayed the development of esophageal stricture in our model. However, this benefit was of limited duration in the conditions of our study.

  4. Quantitative lymphoscintigraphy in post-mastectomy lymphedema: correlation with circumferential measurements

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon Young; Lee, Kyung Han; Kim, Sang Eun; Kim, Byung Tae; Hwang, Jee Hea; Lee, Byung Boong [Samsung Medical Center, Seoul (Korea, Republic of)

    1997-07-01

    An objective measure for the severity and progression is important for the management of lymphedema. To evaluate the usefulness of lympho-scintigraphy in this regard, we compared various quantitative indices from upper extremity lymphoscintigraphy with circumferential measurements, before and after physiotheraphy. Upper extremity lymphoscintigraphy was performed in 38 patients with unilateral postmastectomy lymphedema. Tc-99m antimony sulfide colloid (37 MBq) was injected s.c. into the second and third interdigital spaces. The injection sites were imaged immediately after injection. After standardized exercise for 15 min, upper extremity images were acquired 30 min, 1 hr and 2 hr after injection. The clearance of the injection site (CL), and % uptake in regional lymph nodes (%LN) and soft tissue of the extremity (i.e., the degree of dermal backflow) (%EXT) compared to the initial injection site were calculated. Circumference of each extremity was measured at 7 levels; the severity of lymphedema was expressed as the percentage difference of total circumferential difference (TCD) between healthy and edematous extremities compared to the total circumference of healthy extremity (%TCD). In 19 patients who received physiotherapy, the therapeutic effect was measured by % decrease of TCD (%DTCD) before and after therapy (Raines. et al., 1977). The quantitative indices calculated in the image at 2 hr p.i. had better correlation with either %TCD or %DTCD than those from earlier images (Table). The CL, %LN and %EXT of edematous extremity had a significant correlation with TCD. The %EXT was correlated best with either TCD or %DTCD. The results suggest that the %EXT which corresponds to the degree of dermal backflow may be a simple and useful quantitative index for evaluating the severity and progression in lymphedema and predicting the effect of therapy.

  5. Development of a used fuel cladding damage model incorporating circumferential and radial hydride responses

    Science.gov (United States)

    Chen, Qiushi; Ostien, Jakob T.; Hansen, Glen

    2014-04-01

    At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of δ-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radially-oriented hydride inclusions may weaken the cladding material and lead to issues during used fuel storage and transportation processes. A high fidelity model of the mechanical behavior of hydrides has utility in both designing fuel cladding to be more resistant to this hydride-induced weakening and also in suggesting modifications to drying, storage, and transport operations to reduce the impact of hydride formation and/or the avoidance of loading scenarios that could overly stress the radial inclusions. We develop a mechanical model for the Zry4-hydride system that, given a particular morphology of hydride inclusions, allows the calculation of the response of the hydrided cladding under various loading scenarios. The model treats the Zry4 matrix material as J2 elastoplastic, and treats the hydrides as platelets oriented in predefined directions (e.g., circumferentially and radially). The model is hosted by the Albany analysis framework, where a finite element approximation of the weak form of the cladding boundary value problem is solved using a preconditioned Newton-Krylov approach. Instead of forming the required system Jacobian operator directly or approximating its action with a differencing operation, Albany leverages the Trilinos Sacado package to form the Jacobian via automatic differentiation. We present results that describe the performance of the model in comparison with as-fabricated Zry4 as well as HB Robinson fuel cladding. Further, we also present performance results that demonstrate the efficacy of the overall solution method employed to host the model.

  6. Development of a used fuel cladding damage model incorporating circumferential and radial hydride responses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qiushi, E-mail: qiushi@clemson.edu [Glenn Department of Civil Engineering, Clemson University, Clemson, SC 29634 (United States); Ostien, Jakob T., E-mail: jtostie@sandia.gov [Mechanics of Materials Dept. 8256, Sandia National Laboratories, P.O. Box 969, Livermore, CA 94551-0969 (United States); Hansen, Glen, E-mail: gahanse@sandia.gov [Computational Multiphysics Dept. 1443, Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185-1321 (United States)

    2014-04-01

    At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of δ-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radially-oriented hydride inclusions may weaken the cladding material and lead to issues during used fuel storage and transportation processes. A high fidelity model of the mechanical behavior of hydrides has utility in both designing fuel cladding to be more resistant to this hydride-induced weakening and also in suggesting modifications to drying, storage, and transport operations to reduce the impact of hydride formation and/or the avoidance of loading scenarios that could overly stress the radial inclusions. We develop a mechanical model for the Zry4-hydride system that, given a particular morphology of hydride inclusions, allows the calculation of the response of the hydrided cladding under various loading scenarios. The model treats the Zry4 matrix material as J{sub 2} elastoplastic, and treats the hydrides as platelets oriented in predefined directions (e.g., circumferentially and radially). The model is hosted by the Albany analysis framework, where a finite element approximation of the weak form of the cladding boundary value problem is solved using a preconditioned Newton–Krylov approach. Instead of forming the required system Jacobian operator directly or approximating its action with a differencing operation, Albany leverages the Trilinos Sacado package to form the Jacobian via automatic differentiation. We present results that describe the performance of the model in comparison with as-fabricated Zry4 as well as HB Robinson fuel cladding. Further, we also present performance results that demonstrate the efficacy of the overall solution method employed to host the model.

  7. Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review

    Science.gov (United States)

    Fan, Lihong; Ge, Zhaogang; Zhang, Chen; Li, Jia; Yu, Zefeng; Dang, Xiaoqian; Wang, Kunzheng

    2015-03-01

    The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement.

  8. Initial experience with circumferential pulmonary vein ablation guided by fusion of magnetic resonance imaging with three-dimensional electroanatomic mapping

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; MA Jian; MA Fu-sheng; JlA Yu-he; ZHANG Shu

    2006-01-01

    @@ Catheter ablation for the treatment of atrial fibrillation (AF) has been a focal target of electrophysiological study in recent years. Up to date,circumferential pulmonary vein ablation (CPVA)guided by three-dimensional (3-D) electroanatomic mapping (Carto, USA) has been one of the most favourable procedures for the treatment of AF.

  9. Burn-out, Circumferential Film Flow Distribution and Pressure Drop for an Eccentric Annulus with Heated Rod

    DEFF Research Database (Denmark)

    Andersen, P. S.; Jensen, A.; Mannov, G.

    1974-01-01

    Measurements of (1) burn-out, (2) circumferential film flow distribution, and (3) pressure drop in a 17 × 27.2 × 3500 mm concentric and eccentric annulus geometry are presented. The eccentric displacement was varied between 0 and 3 mm. The working fluid was water. Burn-out curves at 70 bar...... flow variation on burn-out is discussed....

  10. Modeling and numerical investigation of the inlet circumferential fluctuations of swept and bowed blades

    Science.gov (United States)

    Tang, Mingzhi; Jin, Donghai; Gui, Xingmin

    2017-02-01

    The circumferential fluctuation (CF) source terms induced by the inviscid blade force can affect the inlet distribution of flow parameters and radial equilibrium of swept and bowed blades. However, these phenomena cannot be adequately described by throughflow methods based on the axisymmetric assumption. A transport model for the CF stresses is proposed and correlated to the distribution of circulation to reflect the effect of the inviscid blade force. To investigate the effect of the inlet CFs on swept and bowed blades, the model is integrated into a throughflow model and applied to a series of cascades with different sweep and bow angles. For swept cascades, the CF source terms change the distributions of incidence angles, as well as the radial equilibrium at the inlet of the blade passage. And the influence is enhanced as the absolute value of the sweep angle increases. For bowed cascades, the distributions of incidence angles are also altered. For both cases, the model can offer a good prediction of the inlet CF source terms, and prove to exert a better prediction of blade design key parameters such as flow angles.

  11. The Prognostic Value of Circumferential Resection Margin Involvement in Patients with Extraperitoneal Rectal Cancer.

    Science.gov (United States)

    Shin, Dong Woo; Shin, Jin Yong; Oh, Sung Jin; Park, Jong Kwon; Yu, Hyeon; Ahn, Min Sung; Bae, Ki Beom; Hong, Kwan Hee; Ji, Yong Il

    2016-04-01

    The prognostic influence of circumferential resection margin (CRM) status in extraperitoneal rectal cancer probably differs from that of intraperitoneal rectal cancer because of its different anatomical and biological behaviors. However, previous reports have not provided the data focused on extraperitoneal rectal cancer. Therefore, the aim of this study was to examine the prognostic significance of the CRM status in patients with extraperitoneal rectal cancer. From January 2005 to December 2008, 248 patients were treated for extraperitoneal rectal cancer and enrolled in a prospectively collected database. Extraperitoneal rectal cancer was defined based on tumors located below the anterior peritoneal reflection, as determined intraoperatively by a surgeon. Cox model was used for multivariate analysis to examine risk factors of recurrence and mortality in the 248 patients, and multivariate logistic regression analysis was performed to identify predictors of recurrence and mortality in 135 patients with T3 rectal cancer. CRM involvement for extraperitoneal rectal cancer was present in 29 (11.7%) of the 248 patients, and was the identified predictor of local recurrence, overall recurrence, and death by multivariate Cox analysis. In the 135 patients with T3 cancer, CRM involvement was found to be associated with higher probability of local recurrence and mortality. In extraperitoneal rectal cancer, CRM involvement is an independent risk factor of recurrence and survival. Based on the results of the present study, it seems that CRM involvement in extraperitoneal rectal cancer is considered an indicator for (neo)adjuvant therapy rather than conventional TN status.

  12. Performance comparison for oil-water heat transfer of circumferential overlap trisection helical baffle heat exchanger

    Institute of Scientific and Technical Information of China (English)

    王伟晗; 程道来; 刘涛; 刘颖昊

    2016-01-01

    The performance tests were conducted on oil–water heat transfer in circumferential overlap trisection helical baffle heat exchangers with incline angles of 12°, 16°, 20°, 24° and 28°, and compared with a segmental baffle heat exchanger. The results show that the shell side heat transfer coefficientho and pressure dropΔpo both increase while the comprehensive indexho/Δpo decreases with the increase of the mass flow rate of all schemes. And the shell side heat transfer coefficient, pressure drop and the comprehensive indexho/Δpo decrease with the increase of the baffle incline angle at a certain mass flow rate. The average values of shell side heat transfer coefficient and the comprehensive indexho/Δpo of the 12° helical baffled scheme are above 50% higher than those of the segmental one correspondingly, while the pressure drop value is very close and the ratios of the average values are about 1.664 and 1.596, respectively. The shell-side Nusselt numberNuo and the comprehensive index Nuo·Euzo−1 increase with the increase of Reynolds number of the shell side axial in all schemes, and the results also demonstrate that the small incline angled helical scheme has better comprehensive performance.

  13. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats

    Science.gov (United States)

    TAKANO, Hiroshi; ISOGAI, Tomomi; AOKI, Takuma; WAKAO, Yoshito; FUJII, Yoko

    2014-01-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart. PMID:25373881

  14. Vascular Repair by Circumferential Cell Therapy Using Magnetic Nanoparticles and Tailored Magnets.

    Science.gov (United States)

    Vosen, Sarah; Rieck, Sarah; Heidsieck, Alexandra; Mykhaylyk, Olga; Zimmermann, Katrin; Bloch, Wilhelm; Eberbeck, Dietmar; Plank, Christian; Gleich, Bernhard; Pfeifer, Alexander; Fleischmann, Bernd K; Wenzel, Daniela

    2016-01-26

    Cardiovascular disease is often caused by endothelial cell (EC) dysfunction and atherosclerotic plaque formation at predilection sites. Also surgical procedures of plaque removal cause irreversible damage to the EC layer, inducing impairment of vascular function and restenosis. In the current study we have examined a potentially curative approach by radially symmetric re-endothelialization of vessels after their mechanical denudation. For this purpose a combination of nanotechnology with gene and cell therapy was applied to site-specifically re-endothelialize and restore vascular function. We have used complexes of lentiviral vectors and magnetic nanoparticles (MNPs) to overexpress the vasoprotective gene endothelial nitric oxide synthase (eNOS) in ECs. The MNP-loaded and eNOS-overexpressing cells were magnetic, and by magnetic fields they could be positioned at the vascular wall in a radially symmetric fashion even under flow conditions. We demonstrate that the treated vessels displayed enhanced eNOS expression and activity. Moreover, isometric force measurements revealed that EC replacement with eNOS-overexpressing cells restored endothelial function after vascular injury in eNOS(-/-) mice ex and in vivo. Thus, the combination of MNP-based gene and cell therapy with custom-made magnetic fields enables circumferential re-endothelialization of vessels and improvement of vascular function.

  15. Interactions of a propeller with a stator-induced circumferentially varying flow

    Energy Technology Data Exchange (ETDEWEB)

    Farnsworth, John [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); US Air Force Academy, Department of Aeronautics, Colorado Springs, CO (United States); Amitay, Michael [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); Rensselaer Polytechnic Institute, Center for Flow Physics and Control (CeFPaC), Troy, NY (United States); Beal, David; Huyer, Stephen A. [Naval Undersea Warfare Center, Division, Vehicle Dynamics and Signature Control, Newport, RI (United States)

    2012-02-15

    The interactions of a circumferentially varying stator cascade and a downstream fixed pitch propeller were investigated experimentally. The global performance of the components and the coupled system were systematically investigated through force and moment measurements on the propulsor model in a water tunnel. In addition, the wake of the cyclic stator cascade with and without the propeller was investigated downstream from a propulsor model using the Stereoscopic PIV technique. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the flow field downstream of the stator array. The stator distribution alone produced a significant side force that increased linearly with stator pitch amplitude. When a propeller was incorporated downstream from the cyclic cascade, the side force from the stator cascade was reduced, but a small normal force and pitching moment were created. The generation of these secondary forces and moments can be related to the redistribution of the tangential flow from the cyclic cascade into the axial direction by the retreating and advancing blade states of the fixed pitch propeller. (orig.)

  16. Leak before break behaviour of austenitic and ferritic pipes containing circumferential defects

    Energy Technology Data Exchange (ETDEWEB)

    Stadtmueller, W.; Sturm, D.

    1997-04-01

    Several research projects carried out at MPA Stuttgart to investigate the Leak-before-Break (LBB) behavior of safety relevant pressure bearing components are summarized. Results presented relate to pipes containing circumferential defects subjected to internal pressure and external bending loading. An overview of the experimentally determined results for ferritic components is presented. For components containing postulated or actual defects, the dependence of the critical loading limit on the defect size is shown in the form of LBB curves. These are determined experimentally and/or by calculation for through-wall slits, and represent the boundary curve between leakage and massive fracture. For surface defects and a given bending moment and internal pressure, no fracture will occur if the length at leakage remains smaller than the critical defect length given by the LBB curve for through-wall defects. The predictive capability of engineering calculational methods are presented by way of example. The investigation programs currently underway, testing techniques, and initial results are outlined.

  17. Error Modeling and Compensation of Circular Motion on a New Circumferential Drilling System

    Directory of Open Access Journals (Sweden)

    Qiang Fang

    2015-01-01

    Full Text Available A new flexible circumferential drilling system is proposed to drill on the fuselage docking area. To analyze the influence of the circular motion error to the drilling accuracy, the nominal forward kinematic model is derived using Denavit-Hartenberg (D-H method and this model is further developed to model the kinematic errors caused by circular positioning error and synchronization error using homogeneous transformation matrices (HTM. A laser tracker is utilized to measure the circular motion error of the two measurement points at both sides. A circular motion compensation experiment is implemented according to the calculated positioning error and synchronization error. Experimental results show that the positioning error and synchronization error were reduced by 65.0% and 58.8%, respectively, due to the adopted compensation, and therefore the circular motion accuracy is substantially improved. Finally, position errors of the two measurement points are analyzed to have little influence on the measurement result and the validity of the proposed compensation method is proved.

  18. Circumferential 2D-strain imaging for the prediction of long term response to cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2008-06-01

    Full Text Available Abstract Background Cardiac Resynchronization Therapy (CRT leads to hemodynamic and clinical improvement in heart failure patients. The established methods to evaluate myocardial asynchrony analyze longitudinal and radial myocardial function. This study evaluates the new method of circumferential 2D-strain imaging in the prediction of the long-term response to CRT. Methods and results 38 heart failure patients (NYHA II-III, QRS > 120 ms, LVEF Conclusion There is a significant decrease in the circumferential 2D-strain derived delays after CRT, indicating that resynchronization induces improvement in all three dimensions of myocardial contraction. However, the resulting predictive values of 2D strain delays are not superior to longitudinal and radial 2D-strain or TDI delays.

  19. Flood inundation extent in storage cell mode

    Institute of Scientific and Technical Information of China (English)

    G.; Farahi; Saeed; Reza; Khodashenas; B.; Ghahraman; K.; Esmaeeli

    2009-01-01

    An understanding of floodplain processes in general and floodplains flooding in particular are vital issues for river engineers and managers. Insufficient observations of flood inundation extent and the infrequent nature of flood inundation necessitate some sort of predictive tools. In this paper flood inundation extent has been simulated by HEC-RAS software in two storage cell and normal modes and capabilities and limitations of the two models have been determined by comparing simulated and observed flood inundation extent which occurred in the study area on Feb 4th, 2004.

  20. Flood inundation extent in storage cell mode

    Institute of Scientific and Technical Information of China (English)

    G.Farahi; Saeed Reza Khodashenas; B.Ghahraman; K.Esmaeeli

    2009-01-01

    An understanding of floodplaln processes In general and floodplains flooding in particular are vital issues for river engineers and managers.Insufficient observations of flood inundation extent and the infrequent nature of flood inundation necessitate some sort of predictive tools.In this paper flood in-undation extent has been simulated by HEC-RAS software in two storage cell and normal modes and capabilities and limitations of the two models have been determined by comparing simulated and ob-served flood inundation extent which occurred in the study area on Feb 4th, 2004.

  1. Comparison of treatment for 153 cases of circumferential facial paralysis by low-power laser and galvan acupuncture

    Science.gov (United States)

    Li, Hai-Ling; Zhuo, Qing-shan

    1993-03-01

    Seventy-six patients were treated by low power He-Ne laser irradiation on Yangbai, Sibai, and other related acupoints. The other 77 cases were treated by Galvan-acupuncture with infrared radiation on the same acupoints. There was little difference between the therapeutic effects of these two groups (P > 0.05). However, the laser group had a much shorter treatment time than the other group. According to the theory of traditional Chinese medicine, circumferential facial paralysis is caused by exposure to cold which blocks the channel of vital energy resulting in the damage of bodily function. Acupuncture and moxibustion on certain acupoints can warm up the channels and remove the stasis allowing vital energy to pass through their passages to regulate bodily functions. Laser can do the same effectively with much less time. The laser therapy also features painlessness, safeness, and is free of bacteria. Circumferential facial paralysis is a common disease, which is clinically treated by acupuncture with reliable results. However, acupuncture is not fit for children who are not cooperative and those patients who are afraid of the pain accompanied with acupuncture. So we applied low power laser irradiation in the treatment of circumferential facial paralysis starting in 1985. The results were favorable. And the treatment time was shortened. The treatment procedures are reported.

  2. Range Extent for southern sea otters 2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The GIS shapefile "Range extent of southern sea otters 2016" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris...

  3. SYNERGY OF WALL SHEAR STRESS AND CIRCUMFERENTIAL STRESS IN STRAIGHT ARTERIES

    Institute of Scientific and Technical Information of China (English)

    QIN Kai-rong; XU Zhe; WU Hao; JIANG Zong-lai; LIU Zhao-rong

    2005-01-01

    The Wall Shear Stress (WSS) generated by blood flow and Circumferential Stress (CS) driven by blood pressure have been thought to play an important role in blood flow-dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis.The WSS and CS in straight arteries were calculated by measuring the blood pressure, center-line velocity, wall thickness, and radius of vessels.The WSS and CS in the time domain were then decomposed into the amplitude and phase in the frequency domain.The CS amplitude to the WSS amplitude ratio (referred as stress amplitude ratio, Zs) and the phase difference between the CS and the WSS (referred as stress phase difference, SPA) in the frequency domain were calculated to characterize the synergy of the CS and WSS.Numerical results demonstrated that the CS is not in phase with the WSS, a time delay in the time domain or a stress phase difference in the frequency domain between the WSS and the CS exists.Theoretical analysis demonstrated that the Zs and SPA are primarily determined by the local factors (blood viscosity, local inertial effects, local geometry, local elasticity) and the input impedance of whole downstream arterial beds.Because the arterial input impedance has been shown to reflect the physiological and pathological states of whole downstream arterial beds, the stress amplitude ratio Zs and stress phase difference SPA would be thought to be the appropriate indices to reflect the effects of states of whole downstream arterial beds on the local blood flow-dependent phenomena such as angiogenesis, vascular remodeling, and atherosgenesis.

  4. Measurement of the circumferential mechanical properties of the umbilical vein: experimental and numerical analyses.

    Science.gov (United States)

    Karimi, Alireza; Navidbakhsh, Mahdi; Rezaee, Taraneh; Hassani, Kamran

    2015-01-01

    Coronary artery disease is responsible for almost 30% of all deaths worldwide. The saphenous vein and umbilical vein (UV) are the most common veins using for treatment as a coronary artery bypass graft (CABG). The mechanical properties of UV belonging to its long-term patency for CABG are very important. However, there is a lack of knowledge on the linear elastic and nonlinear hyperelastic mechanical properties of the UV. In this study, three stress definitions (second Piola-Kichhoff stress, engineering stress and true stress) and four strain definitions (Almansi-Hamel strain, Green-St Venant strain, engineering strain and true strain) are used to determine the elastic modulus, maximum stress and strain of eight human UVs under circumferential loading. The nonlinear mechanical behaviour of the UV is computationally investigated using Mooney-Rivlin hyperelastic model. A numerical finite element analysis is also carried out to simulate the constitutive modelling versus its numerical results. The results show that the Almansi-Hamel strain definition overestimates the elastic modulus while Green-St Venant strain definition underestimates the elastic modulus at different stress definitions. The true stress-true strain definition, which gives more accurate measurements of the tissue's response using the instantaneous values, reveals the Young's modulus and maximum stress of 2.18 and 6.01 MPa, respectively. The Mooney-Rivlin material model is well represented by the nonlinear mechanical behaviour of the UV. The findings of this study could have implications not only for understanding the extension and rupture mechanism of UV but also for interventions and surgeries, including balloon angioplasty, bypass and stenting.

  5. The Interaction between Fluid Wall Shear Stress and Solid Circumferential Strain Affects Endothelial Gene Expression.

    Science.gov (United States)

    Amaya, Ronny; Pierides, Alexis; Tarbell, John M

    2015-01-01

    Endothelial cells lining the walls of blood vessels are exposed simultaneously to wall shear stress (WSS) and circumferential stress (CS) that can be characterized by the temporal phase angle between WSS and CS (stress phase angle - SPA). Regions of the circulation with highly asynchronous hemodynamics (SPA close to -180°) such as coronary arteries are associated with the development of pathological conditions such as atherosclerosis and intimal hyperplasia whereas more synchronous regions (SPA closer to 0°) are spared of disease. The present study evaluates endothelial cell gene expression of 42 atherosclerosis-related genes under asynchronous hemodynamics (SPA=-180 °) and synchronous hemodynamics (SPA=0 °). This study used a novel bioreactor to investigate the cellular response of bovine aortic endothelial cells (BAECS) exposed to a combination of pulsatile WSS and CS at SPA=0 or SPA=-180. Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes. The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65. These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

  6. The Interaction between Fluid Wall Shear Stress and Solid Circumferential Strain Affects Endothelial Gene Expression.

    Directory of Open Access Journals (Sweden)

    Ronny Amaya

    Full Text Available Endothelial cells lining the walls of blood vessels are exposed simultaneously to wall shear stress (WSS and circumferential stress (CS that can be characterized by the temporal phase angle between WSS and CS (stress phase angle - SPA. Regions of the circulation with highly asynchronous hemodynamics (SPA close to -180° such as coronary arteries are associated with the development of pathological conditions such as atherosclerosis and intimal hyperplasia whereas more synchronous regions (SPA closer to 0° are spared of disease. The present study evaluates endothelial cell gene expression of 42 atherosclerosis-related genes under asynchronous hemodynamics (SPA=-180 ° and synchronous hemodynamics (SPA=0 °. This study used a novel bioreactor to investigate the cellular response of bovine aortic endothelial cells (BAECS exposed to a combination of pulsatile WSS and CS at SPA=0 or SPA=-180. Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2 and CS (4 ± 4% over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes. The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65. These data suggest that asynchronous hemodynamics (SPA=-180 ° can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

  7. Single-stage Posterior Spondylectomy,Circumferential Decompression and Reconstruction Using Mesh Cage for Spinal Tumors

    Institute of Scientific and Technical Information of China (English)

    Yong Zhu; Hong Zhao; Giu-xing Qiu; Jian-guo Zhang; Ye Tian; Shu-gang Li; Suo-mao Yuan

    2009-01-01

    Objective To explore the feasibility and clinical results of circumferential decompression and threecolumn reconstruction through single-stage posterior transpedicular approach for spinal tumor treatment.Methods Totally,24 patients with spinal tumor underwent tumor resection and spinal reconstruction through single-stage posterior transpedicular approach.Preoperatively,according to the Frankel classification,12 patients were grade E,9 grade D,and 3 grade C.Anterior column was reconstructed with non-expandable titanium cages.Posterior segmental instrumentation was used to maintain the stability of spine in all cases.Anterior and posterolateral fusion was performed with autograft and allogenic bone.The following data were followed up in these patients:deformity angle,local recurrence,neurological function,and spinal bony fusion.Results The average operating time and blood loss was 5.6 hours and 3 400 ml respectively.No intraoperative and postoperative complications were observed in this group.Postoperatively,21 patients were Frankel grade E,2 grade D,and 1 grade C.Four patients reported significant functional restoration and twenty patients reported complete resolution of pain.At follow-up(range,6-42 months),implant failure or recurrent neurological symptoms was not found.Conclusions The tumor resection and spinal reconstruction through single-stage posterior transpedicular approach is a safe and effective technique for the treatment of spinal tumor.It can fully decompress the neurological structures,correct the kyphosis,and achieve early weight-bearing.This technique can improve life quality for the patients with spinal tumor.

  8. Control of circumferential wall stress and luminal shear stress within intact vascular segments perfused ex vivo.

    Science.gov (United States)

    El-Kurdi, Mohammed S; Vipperman, Jeffrey S; Vorp, David A

    2008-10-01

    Proportional, integral, and derivative (PID) controllers have proven to be robust in controlling many applications, and remain the most widely used control system architecture. The purpose of this work was to use this architecture for designing and tuning two PID controllers. The first was used to control the physiologic arterial circumferential wall stress (CWS) and the second to control the physiologic arterial shear stress (SS) imposed on intact vascular segments that were implanted into an ex vivo vascular perfusion system (EVPS). In order to most accurately control the stresses imposed onto vascular segments perfused ex vivo, analytical models were derived to calculate the CWS and SS. The mid-vein-wall CWS was calculated using the classical Lame solution for thick-walled cylinders in combination with the intraluminal pressure and outer diameter measurements. Similarly, the SS was calculated using the Hagen-Poiseuille equation in combination with the flow rate and outer diameter measurements. Performance of each controller was assessed by calculating the root mean square of the error (RMSE) between the desired and measured process variables. The performance experiments were repeated ten times (N=10) and an average RMSE was reported for each controller. RMSE standard deviations were calculated to demonstrate the reproducibility of the results. Sterile methods were utilized for making blood gas and temperature measurements in order to maintain physiologic levels within the EVPS. Physiologic blood gases (pH, pO(2), and pCO(2)) and temperature within the EVPS were very stable and controlled manually. Blood gas and temperature levels were recorded hourly for several (N=9) 24 h perfusion experiments. RMSE values for CWS control (0.427+/-0.027 KPa) indicated that the system was able to generate a physiologic CWS wave form within 0.5% error of the peak desired CWS over each cardiac cycle. RMSE values for SS control (0.005+/-0.0007 dynescm(2)) indicated that the system

  9. Updated Vertical Extent of Collision Damage

    DEFF Research Database (Denmark)

    Tagg, R.; Bartzis, P.; Papanikolaou, P.;

    2002-01-01

    The probabilistic distribution of the vertical extent of collision damage is an important and somewhat controversial component of the proposed IMO harmonized damage stability regulations for cargo and passenger ships. The only pre-existing vertical distribution, currently used in the international...

  10. Spatial Extent of Random Laser Modes

    NARCIS (Netherlands)

    Molen, van der Karen L.; Tjerkstra, R. Willem; Mosk, Allard P.; Lagendijk, Ad

    2007-01-01

    We have experimentally studied the distribution of the spatial extent of modes and the crossover from essentially single-mode to distinctly multimode behavior inside a porous gallium phosphide random laser. This system serves as a paragon for random lasers due to its exemplary high index contrast. I

  11. K{sub I}-T estimation for embedded flaws in pipes - Part II: Circumferentially oriented cracks

    Energy Technology Data Exchange (ETDEWEB)

    Qian Xudong, E-mail: cveqx@nus.edu.s [Department of Civil Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore)

    2010-04-15

    This paper, in parallel to the investigation on axially embedded cracks reported in the companion paper, presents a numerical study on the linear-elastic K{sub I} and T-stress values over the front of elliptical cracks circumferentially embedded in the wall of a pipe/cylindrical structure, under a uniform pressure applied on the inner surface of the pipe. The numerical procedure employs the interaction-integral approach to compute the linear-elastic stress-intensity factor (SIF) K{sub I} and T-stress values for embedded cracks with practical sizes at different locations in the wall of the pipe. The parametric study covers a wide range of geometric parameters for embedded cracks in the pipe, including: the wall thickness to the inner radius ratio (t/R{sub i}), the crack depth over the wall thickness ratio (a/t), the crack aspect ratio (a/c) and the ratio of the distance from the centerline of the crack to the outer surface of the pipe over the pipe wall thickness (e{sub M}/t). The parametric investigation identifies a significant effect of the remaining ligament length on both the T-stress and K{sub I} values at the crack-front location (denoted by point O) nearest to the outer surface of the pipe and at the crack-front location (denoted by point I) nearest to the inner surface of the pipe. The numerical investigation establishes the database to derive approximate functions from a nonlinear curve-fitting procedure to predict the T-stress and K{sub I} values at three critical front locations of the circumferentially embedded crack in a pipe: points O, I and M. The proposed T-stress and K{sub I} functions utilize a combined second-order polynomial and a power-law expression, which presents a close agreement with the T-stress and K{sub I} values computed from the very detailed finite element models. The comparison between the circumferentially embedded crack and the axially embedded crack indicates that both the T-stress and K{sub I} values at crack-front points O and

  12. Contribution to the Evaluation of the Circumferentially-Cracked Round Bar for Fracture Toughness Determination of Reactor Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, M

    1999-06-01

    The subject of this PhD dissertation is the use of the Circumferentially-Cracked Round Bar (CRB) for fracture toughness measurements. The main advantages of CRB are the relatively small size requirements of the testing specimens, the low cost to machine the specimen, the rotating bending fatigue allowing for easy precracking of specimens, the use of standard tensile test fixture and the axisymmetry of the specimen that avoids time consuming 3D finite element calculations. An in-depth study of the most widely used precracking technique for CRB, namely the rotating bending fatigue, is made.

  13. Prediction of weld penetration extent in GTAW

    Institute of Scientific and Technical Information of China (English)

    Zhao Ming; Zhai Lei

    2008-01-01

    The governing equations of surface-deformation in fully-penetrated GTA W weld pool are derived. The solution scheme of the Lagrange multiplier, which makes the top sutface-deformation equation be coupled with that for the bottomsurface of a single weld pool, is given out. Through numerical analysis of weld pool surface-deformation in GTA W,it is found that there is clear correlation between the penetration extent and the Lagrange multiplier, in addition to the relationship between the penetration extent and the maximum depression and hump as well as the depressed volume of the top surface of weld pool. It lays good foundation for top-side sensing based weld penetration control.

  14. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masashi, E-mail: m.nakamura1230@gmail.com [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan); Kido, Tomoyuki [Department of Radiology, Saiseikai Matsuyama Hospital, Ehime 791-0295 (Japan); Kido, Teruhito; Tanabe, Yuki; Matsuda, Takuya; Nishiyama, Yoshiko; Miyagawa, Masao; Mochizuki, Teruhito [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan)

    2015-08-15

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

  15. Correlation among bioimpedance analysis, sonographic and circumferential measurement in assessment of breast cancer-related arm lymphedema.

    Science.gov (United States)

    Choi, Y H; Seo, K S

    2014-09-01

    New approaches for assessment of lymphedema using ultrasonography (US) have been introduced recently and are reported to be reliable and simple. Ultrasonography provides detailed information about physical properties of the tissue in addition to volume and size. There have been only limited studies comparing bioimpedance analysis (BIA), US, and circumferential measurement (CM), which is considered a standard measurement. The aim of this study was to determine the relationship between US, BIA, and CM. Twenty-eight patients with lymphedema after breast cancer surgery underwent BIA, US, and CM. Impedance, which reflects the amount of extracellular fluid, was measured with 1 kHz frequency in affected and unaffected arms. Circumferences were measured at 10cm proximal and distal to the elbow and a truncated cone method used to calculate estimated volumes for upper arm and forearm. We found that interlimb forearm subcutis thickness differences measured by US were highly correlated with CM measurements and that interlimb upper arm subcutis thickness differences measured by US were moderately correlated with CM measurements and BIA ratios. However, the interlimb ratio of compressibility measured by US showed no or only weak correlation with impedance measurements and circumferential measurements. Our results also show that compressibility measured by US could not be predicted from BIA or CM measurements despite a high degree of concordance among subcutis thickness measured by US, CM, and BIA.

  16. Measurement of the longitudinal and circumferential muscular activity associated with peristalsis using a single fibre grating array

    Science.gov (United States)

    Arkwright, J. W.; Blenman, N. G.; Underhill, I. D.; Maunder, S. A.; Spencer, N. J.; Costa, M.; Brooks, S. J.; Szczesniak, M. M.; Dinning, P. G.

    2010-09-01

    Diagnostic catheters based on fibre Bragg gratings (FBG's) are proving to be highly effective for measurement of the muscular activity associated with peristalsis in the human gut. The primary muscular contractions that generate peristalsis are circumferential in nature; however, it has long been known that there is also a component of longitudinal contractility present, acting in harmony with the circumferential component to improve the overall efficiency of material movement. To date, there have been relatively few reports on the measurement or inference of longitudinal contractions in humans and all have been limited to detection at a single location only. This is due to the lack of a viable recording technique suitable for real-time in-vivo measurement of this type of activity over extended lengths of the gut. We report the detection of longitudinal motion in lengths of excised mammalian colon using an FBG technique that should be viable for similar detection in humans. The longitudinal sensors have been combined with our previously reported FBG pressure sensing elements to form a composite catheter that allows the relative phase between the two components to be detected. The catheter output has been validated using digital video mapping in an ex-vivo animal preparation using lengths of rabbit ileum.

  17. Marcapasso endocárdico definitivo na primeira década de vida Permanent endocardial pacemaker in the first decade of life

    Directory of Open Access Journals (Sweden)

    Roberto Costa

    1986-12-01

    ão necessita outros tipos de prótese para acomodar o eletrodo; 3 permite o acompanhamento seguro da criança com simples estudo radiológico; 4 preserva o sistema cava superior para a utilização na idade adulta; 5 permite, ainda, a integração social perfeita da criança, que poderá participar de atividades esportiva e de lazer, sem que o marcapasso seja notado pelas outras crianças.Pacemaker implantation in children represents a challenge due to the lack of flexibility of the existing system in relation to the growth of the patients to difficulties in choosing the best place to insert the pulse generator and to technical and social problems as well. Even in Services where the first option should have been the endocardial via, the epicardial implantation has been employed in low weight children. At the INCOR - USP, from November 1980 to October 1985, there were 21 endocardial pacemaker implantations in children at the first decade of their lives. The implantation technique consists of lead insertion through the femoral vein, leaving a loop in the right atrium and placing of the pulse generator in the illiac region. After few years, when the growth of the patient has stretched the lead, the child is reoperated to liberate more leak and to form a new loop, thus allowing the use of the same system for a very long period. The age of the patients varied from 2 months to 10 years. Thirteen of the 21 children were less than 5 years old, and 5 were in their first year of life. The predominant indication was 3rd. degree A-V block (90%, which in 75% of the cases was postoperative. In the follow-up period - three to 63 months and mean of 26 months - 3 patients died from causes unrelated to the pacemaker; the remaining patientsare well. Five children have been reoperated on to liberate the lead from the pulse generator pocket and to form a new loop in the atrium. The advantages of this technique were observed in the follow-up, as compared to epicardial and conventional endocardial

  18. A CART extention using Quadratic Decision Borders

    DEFF Research Database (Denmark)

    Hartelius, Karsten

    1999-01-01

    In this article we put forward an extention to the hierarchical CART classification method which uses quadratic decision borders. The original CART applies univariate splits on individual variables as well as splits on combinations of variables to recursively partition the feature......-space into subsets which are successively more class-homogeneous. Guided by the fact that class-distributions in feature-space are very often hyper-elliptical shaped, we give an extension to the original CART which also uses quadratic shaped decision borders which can be modelled by a mean-vector and a dispersion...

  19. Research Misconduct—Definitions, Manifestations and Extent

    Directory of Open Access Journals (Sweden)

    Lutz Bornmann

    2013-10-01

    Full Text Available In recent years, the international scientific community has been rocked by a number of serious cases of research misconduct. In one of these, Woo Suk Hwang, a Korean stem cell researcher published two articles on research with ground-breaking results in Science in 2004 and 2005. Both articles were later revealed to be fakes. This paper provides an overview of what research misconduct is generally understood to be, its manifestations and the extent to which they are thought to exist.

  20. Circumferential fusion is dominant over posterolateral fusion in a long-term perspective: cost-utility evaluation of a randomized controlled trial in severe, chronic low back pain

    DEFF Research Database (Denmark)

    Soegaard, Rikke; Bünger, Cody E; Christiansen, Terkel

    2007-01-01

    STUDY DESIGN: Cost-utility evaluation of a randomized, controlled trial with a 4- to 8-year follow-up. OBJECTIVE: To investigate the incremental cost per quality-adjusted-life-year (QALY) when comparing circumferential fusion to posterolateral fusion in a long-term, societal perspective. SUMMARY...... demonstrated clinical superiority over the posterolateral fusion group in functional outcome (P dominant over posterolateral fusion, that is, for each QALY gained...... the circumferential approach could alter the dominance; however, still the probability of cost-effectiveness was >0.85 given a threshold for willingness to pay of U.S. $50,000 per QALY. CONCLUSION: Circumferential fusion is dominant over instrumented posterolateral fusion, that is, both being significantly cheaper...

  1. Extent and determinants of patients' unvoiced needs.

    Science.gov (United States)

    Low, Lee Lan; Sondi, Sararaks; Azman, Abu Bakar; Goh, Pik Pin; Maimunah, A Hamid; Ibrahim, Mohd Yusof; Hassan, Muhammad Radzi Abu; Letchuman, Ramanathan

    2011-09-01

    Patients with issues or health problems usually plan to discuss their concerns with their health care providers. If these concerns were not presented or voiced during the health care provider-patient encounter, the patients are considered to have unvoiced needs. This article examines the extent and possible determinants of patients' unvoiced needs in an outpatient setting. A cross-sectional study was conducted in 5 Ministry of Health Malaysia primary health facilities throughout the country. Of 1829 who participated, 5 did not respond to the question on planned issues. Of the 1824 respondents, 57.9% (95% confidence interval = 47.1-68.7) claimed to have issues/problems they planned to share, of whom 15.1% to 26.7% had unvoiced needs. Extent of unvoiced needs differed by employment status, perceived category of health care provider, and study center. Perceived category of health care provider, method of questionnaire administration, and study center were the only significant determinants of unvoiced needs. Unvoiced needs do exist in Malaysia and there is a need for health care providers to be aware and take steps to counter this.

  2. Early posterior spinal canal decompression and circumferential reconstruction of rotationally unstable thoracolumbar burst fractures with neurological deficit

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guo-quan; WANG Yan; TANG Pei-fu; ZHANG Yong-gang; ZHANG Xue-song; GUO Yi-zhu; TAO Sheng

    2013-01-01

    Background Among the various treatments of neurologically involved unstable thoracolumbar burst fractures,the combination of anterior and posterior instrumentation provides the most stable reconstruction.However,the use of both approaches on a trauma patient may increase the morbidity.This study is a retrospective matched cohort study to evaluate the advantages of a single stage posterior approach for spinal canal decompression in combination with circumferential reconstruction by comparing the clinical and radiographic results.Methods From March 2005 to September 2009,patients with matched type spinal fracture,ages at surgery,and involved levels in our institute underwent either a single stage posterior approach (group one,n=12) or traditional combined approach (group two,n=14) for spinal canal decompression and circumferential reconstruction were reviewed.Pre-and post-operative X-ray films were reviewed and changes in Cobb angle of thoracolumbar spine were documented.Intra-operative,post-operative,and general complications were registered.Results The mean follow-up was (27.7±9.6) months (range,14 to 56 months) in group one and (29.2±7.4) months (range,20 to 60 months) in group two (P >0.05).The mean operation time was 214 minutes (range,186-327 minutes) in group one and 284 minutes (range,219-423 minutes) in group two (P <0.05).The average volume of intraoperative blood loss was 1856 ml (range,1250-3480 ml) in group one and 2453 ml (range,1600-3680 ml) in group two (P <0.05).There was no statistical difference between the groups one and two in average vertebral body height loss at the injured level and the average Cobb angle in sagittal plane before and immediately after surgery.Postoperatively,there was an epidural hematoma in one patient in group one and two patients in group two.Bony union after stabilization was obtained in all patients,without loosening or breakage of screws.Loss of correction (5°) was seen in 1 patient in group one at the 6th month

  3. The Geographic Extent of Global Supply Chains

    DEFF Research Database (Denmark)

    Machikita, Tomohiro; Ueki, Yasushi

    2012-01-01

    We study the extent to which inter-firm relationships are locally concentrated and what determines firm differences in geographic proximity to domestic or foreign suppliers and customers. From micro-data on selfreported customer and supplier data of firms in Indonesia, the Philippines, Thailand......, and Vietnam, we measure the distances between firm pairs, that is, the distance to the main supplier and the distance to the main customer for the surveyed firms. The distances to suppliers and customers are shorter for indigenous firms in these Southeast Asian countries; but the arm’s length differs across...... countries. The distance between firm pairs differs widely across firms within narrowly defined industries and countries. We find that both firm-level transaction costs and capabilities affect the distances between customers and suppliers. The distance to suppliers is longer for firms that have accepted...

  4. Quantifying the Cognitive Extent of Science

    CERN Document Server

    Milojević, Staša

    2015-01-01

    While the modern science is characterized by an exponential growth in scientific literature, the increase in publication volume clearly does not reflect the expansion of the cognitive boundaries of science. Nevertheless, most of the metrics for assessing the vitality of science or for making funding and policy decisions are based on productivity. Similarly, the increasing level of knowledge production by large science teams, whose results often enjoy greater visibility, does not necessarily mean that "big science" leads to cognitive expansion. Here we present a novel, big-data method to quantify the extents of cognitive domains of different bodies of scientific literature independently from publication volume, and apply it to 20 million articles published over 60-130 years in physics, astronomy, and biomedicine. The method is based on the lexical diversity of titles of fixed quotas of research articles. Owing to large size of quotas, the method overcomes the inherent stochasticity of article titles to achieve...

  5. Analytical and experimental investigations into the controlled energy absorption characteristics of thick-walled tubes with circumferential grooves

    Energy Technology Data Exchange (ETDEWEB)

    Darvizeh, Abolfazl [Islamic Azad University, Bandar-e Anzali (Iran, Islamic Republic of); Darvizeh, Mansour; Ansari, Reza; Meshkinzar, Ata [University of Guilan, Rasht (Iran, Islamic Republic of)

    2014-10-15

    In this paper, the energy absorption characteristics of grooved circular tubes are investigated under quasi-static loading condition. For experiments, thick-walled tubes with circumferential grooves are prepared. The grooves divide the thick-walled tube into several shorter thin-walled portions. Specimens are subjected to axial crushing load to observe the effect of distribution of circular grooves on the deformation mechanism and energy absorption capacity. Geometrical parameters of the specimens are designed utilizing the Taguchi method to cover a reasonably wide range of groove length-to-wall thickness ratios. An analytical approach based on the concept of energy dissipation through the plastic hinges is applied. Taking the effect of strain hardening into account, the obtained analytical results are in good agreement with the experimental ones. The agreement between analytical and experimental results may indicate the validity of the proposed analytical approach. Desirable mechanism of deformation observed justifies the pre-forming method for obtaining favorable energy absorption characteristics.

  6. Transverse shear effects on the stress-intensity factor for a circumferentially cracked, specially orthotropic cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1977-01-01

    The problem of a cylindrical shell containing a circumferential through crack is considered by taking into account the effect of transverse shear deformations. The formulation is given for a specially orthotropic material within the confines of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions regarding moment and stress resultants on the crack surface. Consequently, aside from multiplicative constants representing the stress intensity factors, the membrane and bending components of the asymptotic stress fields near the crack tip are found to be identical. The stress intensity factors are calculated separately for a cylinder under a uniform membrane load, and that under a uniform bending moment. Sample results showing the nature of the out-of-plane crack surface displacement and the effect of the Poisson's ratio are presented.

  7. Experimental investigation on fracture toughness of Al6061–graphite by using Circumferential Notched Tensile Specimens

    Directory of Open Access Journals (Sweden)

    Saleemsab Doddamani

    2017-01-01

    Full Text Available This paper presents the experimental work carried out on the fracture behavior of aluminium 6061 (Al6061 and graphite particulate composites. The required specimens are prepared using stir casting method with graphite proportions ranging from 3 to 12 % by weight. The fracture behavior of Al6061-graphite particulate composites produced using stir casting method, was investigated by conducting experiments on Universal Testing Machine (UTM. Circumferential Notched Tensile (CNT specimens were utilized to evaluate the fracture toughness of the composites. From the experiment the fracture toughness KIC= 15.85MPa m1/2 is obtained for Al6061-9% Graphite. Further, the experimental results revealed that, except 12% graphite, the fracture toughness of Al6061-graphite was observed to increases with an increase in weight percentage of graphite. The experimental results reinforce that Al6061-graphite particulate MMCs are suitable for automotive and aerospace applications requiring high fracture toughness apart from good wear resistance.

  8. CFD Study of the Hydrocarbon Boost Low-Pressure Inducer and Kicker in the Presence of a Circumferential Groove

    Science.gov (United States)

    Coker, Robert

    2011-01-01

    Results are presented of a computational fluid dynamics (CFD) study done in support of Marshall Space Flight Center's (MSFC) sub-scale water flow experiments of the Hydrocarbon Boost (HCB) Oxidizer Turbopump (OTP) being developed by the Air Force Research Laboratory (AFRL) and Aerojet. A circumferential groove may be added to the pump to reduce synchronous cavitation and subsequent bearing loads at a minimal performance cost. However, the energy may reappear as high order cavitation (HOC) that spans a relatively large frequency range. Thus, HOC may have implications for the full-scale OTP inducer in terms of reduced structural margin at higher mode frequencies. Simulations using the LOCI/Stream CFD program were conducted in order to explore the fluid dynamical impact of the groove on the low-pressure inducer and kicker. It was found that the circumferential groove has minimal head performance impact, but causes back-flowing high-swirl fluid to interact with the nearly-axial incoming fluid just above the inducer blades. The high-shear interface between the fluids is Kelvin-Helmholtz unstable, resulting in trains of low pressure regions or 'pearls' forming near the upstream edge of the groove. When the static pressure in these regions becomes low enough and they get cut by the blade leading edge, HOC is thought to occur. Although further work is required, the numerical models indicate that HOC will occur in the runbox of the AFRL/Aerojet HCB OTP. Comparisons to the ongoing water flow experiments will be discussed, as well as possible designs that may mitigate HOC while continuing to reduce synchronous cavitation. December 2011 MSS/LPS/SPS Joint Subcommittee Meeting ABSTRACT SUBMITTAL FORM

  9. OUTCOME OF POSTEROLATERAL FUSION VERSUS CIRCUMFERENTIAL FUSION WITH CAGE FOR LUMBAR STENOSIS AND LOW DEGREE LUMBAR SPONDYLOLISTHESIS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To evaluate the outcome of two methods for stabilization and fusion: posterolateral fusion and circumferential fusion involving posterior lumbar interbody fusion for lumbar stenosis with Grades 1 and 2 lumbar spondylolisthesis. Methods From April 1998 to April 2003, 45 patients suffering from lumbar stenosis with low degree lumbar spondylolisthesis treated in our hospital were retrospectively reviewed and assigned to two groups. Among them, 24 patients (group A) were treated with instrumented posterolateral fusion and 21 patients (group B) with instrumented circumferential fusion. The two groups were compared for clinical and radiological outcomes. Results All patients were followed up for 12 to 72 months. In group A, results showed preoperative clinical symptoms disappeared completely in 12 of 24 patients, and pain relief was seen in 91.7% (22/24). Two cases suffered from residual symptoms. Twenty-two cases obtained complete reduction of olisthy vertebral bodies, and anatomical reduction rate was 91.7%. No infection or neurological complication occurred in this group. In group B, results showed preoperative clinical symptoms disappeared completely in 13 of 21 patients, and pain relief was seen in 90. 5% ( 19/21 ). One case suffered from residual symptoms. Twenty cases obtained complete reduction of the olisthy vertebral bodies, and anatomical reduction rate was 95.2%. Four cases of infection or neurological complication occurred in this group. Both groups indicated no significant difference in clinical outcomes and anatomical reduction rate during followup. But group A had better intraoperative circumstances and postoperative outcome than group B, while group B had better postoperative parameters in X-ray of Angle of Slipping and Disc Index than group A.Conclusions The first choice of surgical method for lumbar stenosis with low degree lumbar spondylolisthesis is instrumented posterolateral fusion. Only when patients suffer from severe preoperative disc

  10. Fracture problem for an external circumferential crack in a functionally graded superconducting cylinder subjected to a parallel magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Z. [Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China); Gao, S.W. [College of Civil Engineering, Hebei Institute of Architecture and Civil Engineering, Zhangjiakou 075000 (China); Feng, W.J., E-mail: wjfeng9999@126.com [Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 050043 (China)

    2016-02-15

    Highlights: • External circumferential crack problem of superconducting cylinder is investigated. • A functionally graded superconducting cylinder is analyzed. • The magnetically impermeable crack surface condition is applied. • The generalized Irie-Yamafuji critical state model outside the crack region is adopted. - Abstract: In this study, the multiple isoparametric finite element method (MIFEM) is used to investigate external circumferential crack problem of a functionally graded superconducting cylinder subjected to electromagnetic forces. The superconducting cylinder is composed by Bi2223/Ag composite with material parameters varying. A crack reference region is defined to reflect the effects of crack on flux and current densities, and the magnetically impermeable crack surface condition and the generalized Irie–Yamafuji critical state model outside the crack region are adopted. The distributions of magnetic flux density in the superconducting cylinder are obtained analytically for both the zero-field cooling (ZFC) and the field cooling (FC) activation processes. Based on the MIFEM, the stress intensity factors (SIFs) at crack fronts in the process of field ascent and/or descent are then numerically calculated. It is interesting to note from numerical results that for the present crack model in the ZFC activation process, the crack is easily propagate and grow with the applied field increases, and that in the field descent process of either the ZFC case or FC case, the crack generally does not propagate. In addition, in the field ascent process of the ZFC case, the SIFs depend on not only the crack depths and model parameters but also the applied field. The present study should be helpful to the design and application of high-temperature superconductors with external edge cracks.

  11. Total hip replacement using hemi-circumferential interposition acetabuloplasty for acetabular deficiency in post-Perthes deformities: technique and long-term results

    NARCIS (Netherlands)

    D. Haverkamp; H. Eijer; R.K. Marti

    2006-01-01

    We describe a technique of hemi-circumferential interposition grafting that allows placement of the cup in the anatomical position of the original acetabulum in the rare cases of post-Perthes or Perthes-like deformities of the femoral head combined with a steep and shallow acetabulum. This technique

  12. Modeled Combined Extent of All Columbia River Basalt Units (CRB_extent4xconnections)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile was created as a boundary for the Columbia River Basalt extent and a buffered version was used to clip the geomodel unit grids. As part of a U.S....

  13. Radiofrequency Ablation Mapping with Circumferential Catheter for Paroxys-mal Atrial Fibrillation Originating From the Pulmonary Veins

    Institute of Scientific and Technical Information of China (English)

    刘震; 吴书林; 杨平珍; 方咸宏; 李海杰; 陈泗林; 詹贤章; 薛玉梅

    2002-01-01

    Objectives To assessed thefeasibility and effectiveness of electrophysiologicalmapping of pulmonary veins with a circumferential 10-electrode catheter and radiofrequency catheter abla-tion therapy for patients with paroxysmal atrial fibril-lation. Background Standard mapping and ablationof focal sources of atrial fibrillation are associated withvery long procedure times and low efficacy. Mappingand ablation pulmonary veins guide with a circularcatheter could overcome these limitations. Methods16 patients [male 11, female 5, mean age (51 +14.5) years] with paroxysmal atrial fibrillation refrac-tory to antiarrhythmic drugs were included in thisgroup. A circumferential 10-electrode catheter wasused to pulmonary vein mapping during sinus rhythm orCSd pacing to determine the origin of atrial prematurecontractions. When the ablative target pulmonary veinwas found, the pulmonary vein potentials' distributionand activation were assessment pulmonary veins' ostialablation was performed at the segments showing earliestactivation of pulnonary vein potentials. The end pointwas designed: 1 ) elimination of pulmonary vein po-tential; 2) pulmonary vein potential dissociation fromatrial waves; 3) atrial ectopic beats disappear. ResultsA total of 36 pulmonary veins were ablated, in-cluding 16 left superior, 12 right superior, 7 left in-ferior and 1 right inferior. 1 pulmonary vein in 2 pa-tients was ablated, 2 pulmonary veins in 8 patientswere ablated, 3 pulmonary veins were ablated in 5patients and 4 pulmonary veins were ablated in 1 pa-tient. Procedure duration and fluoroscopy time respec-tively were 186.7 _+ 63.8 min and 51.5 + 15.0 min.During the follow-up 1- 12 months, 11 patients(68.7 % ) were free of AF without any antiarrhythmicdrugs, 2 of them were reablation, effective in 3/16(18.7%) and unsuccessful in 2/16 (12.6%) . 2cases recurred with atrial premature, 1 was treated withamiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with

  14. EXPERIMENTAL RESEARCH ON AERODYNAMIC PERFORMANCE AND EXIT FLOW FIELD OF LOW PRESSURE AXIAL FLOW FAN WITH CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, the low pressure axial flow fan with circumferential skewed rotor blade, including the radial blade, the forward-skewed blade and the backward-skewed blade, was studied with experimental methods. The aerodynamic performance of the rotors was measured. At the design condition at outlet of the rotors, detailed flow measurements were performed with a five-hole probe and a Hot-Wire Anemometer (HWA). The results show that compared to the radial rotor, the forward-skewed rotor demonstrates a wider Stable Operating Range (SOR), is able to reduce the total pressure loss in the hub region and make main loading of blade accumulating in the mid-span region. There is a wider wake in the upper mid-span region of the forward-skewed rotor. Compared to the radial rotor, in the backward-skewed rotor there is higher total pressure loss near the hub and shroud regions and lower loss in the mid-span region. In addition, the velocity deficit in the wake is lower at mid-span of the backward-skewed rotor than the forward-skewed rotor.

  15. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    Science.gov (United States)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  16. Effect of anxiety and depression on the recurrence of persistent atrial fibrillation after circumferential pulmonary vein ablation

    Institute of Scientific and Technical Information of China (English)

    YU Sheng-bo; HU Wei; ZHAO Qing-yan; QIN Mu; HUANG He; CUI Hong-ying; HUANG Cong-xin

    2012-01-01

    Background The effects of anxiety and depression on the recurrence of persistent atrial fibrillation (AF) after circumferential pulmonary vein ablation (CPVA) are not clear.Whether CPVA can alleviate the anxiety and depression symptoms of persistent AF patients is unknown.Methods One hundred and sixty-four patients with persistent AF,of which 43 treated with CPVA (CPVA group) and 103 treated with anti-arrhythmics drugs (medicine group),were enrolled.The Zung Self-Rating Anxiety Scale (SAS),and Zung Self-Rating Depression Scale (SDS) were assessed before and 12 months after treatment in all patients.Results The scores of SAS (40.33±7.90 vs.49.76±9.52,P <0.01) and SDS (42.33±8.73 vs.48.17±8.77,P <0.01)decreased 12 months after CPVA.Over 12 months follow-up,AF relapsed in 17 patients in CPVA group.Compared with the data in the recurrent group (17 patients),the scores of SAS and SDS were significantly lower in the non-recurrent group (26 patients) at baseline.The results of multivariate Logistic regression analysis showed normal scores of SAS and SDS were the independent risk factors of AF recurrence after CPVA.Conclusions Anxiety and depression increase the recurrence risk of persistent AF after CPVA.CPVA can ameliorate the anxiety and depression symptoms in patients with persistent AF.

  17. New matrix method for response analysis of circumferentially stiffened non-circular cylindrical shells under harmonic pressure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the governing equation of vibration of a kind of cylindrical shells written in a matrix differential equation of the first order, a new matrix method is presented for steady-state vibration analysis of a noncircular cylindrical shell simply supported at two ends and circumferentially stiffened by rings under harmonic pressure. Its difference from the existing works by Yamada and Irie is that the matrix differential equation is solved by using the extended homogeneous capacity precision integration approach other than the Runge-Kutta-Gill integration method. The transfer matrix can easily be determined by a high precision integration scheme. In addition, besides the normal interacting forces, which were commonly adopted by researchers earlier, the tangential interacting forces between the cylindrical shell and the rings are considered at the same time by means of the Dirac-δ function. The effects of the exciting frequencies on displacements and stresses responses have been investigated. Numerical results show that the proposed method is more efficient than the aforementioned method.

  18. Nondestructive Evaluation of Functionally Graded Subsurface Damage on Cylinders in Nuclear Installations Based on Circumferential SH Waves

    Directory of Open Access Journals (Sweden)

    Zhen Qu

    2016-01-01

    Full Text Available Subsurface damage could affect the service life of structures. In nuclear engineering, nondestructive evaluation and detection of the evaluation of the subsurface damage region are of great importance to ensure the safety of nuclear installations. In this paper, we propose the use of circumferential horizontal shear (SH waves to detect mechanical properties of subsurface regions of damage on cylindrical structures. The regions of surface damage are considered to be functionally graded material (FGM and the cylinder is considered to be a layered structure. The Bessel functions and the power series technique are employed to solve the governing equations. By analyzing the SH waves in the 12Cr-ODS ferritic steel cylinder, which is frequently applied in the nuclear installations, we discuss the relationship between the phase velocities of SH waves in the cylinder with subsurface layers of damage and the mechanical properties of the subsurface damaged regions. The results show that the subsurface damage could lead to decrease of the SH waves’ phase velocity. The gradient parameters, which represent the degree of subsurface damage, can be evaluated by the variation of the SH waves’ phase velocity. Research results of this study can provide theoretical guidance in nondestructive evaluation for use in the analysis of the reliability and durability of nuclear installations.

  19. Multisensor Analyzed Sea Ice Extent - Northern Hemisphere (MASIE-NH)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Multisensor Analyzed Sea Ice Extent Northern Hemisphere (MASIE-NH) products provide measurements of daily sea ice extent and sea ice edge boundary for the...

  20. The use of technetium-99m hexamethylpropylene amine oxime labelled granulocytes with single-photon emission tomography imaging in the detection and follow-up of recurrence of infective endocarditis complicating transvenous endocardial pacemaker

    Energy Technology Data Exchange (ETDEWEB)

    Ramackers, J.M. [Department of Nuclear Medicine, CHU E. Herriot, Lyon (France); Kotzki, P.O. [Department of Nuclear Medicine, CHU Lapeyronie et A. de Villeneuve, Montpellier (France); Couret, I. [Department of Nuclear Medicine, CHU Lapeyronie et A. de Villeneuve, Montpellier (France); Messner-Pellenc, P. [Department of Cardiology, CHU Lapeyronie et A. Villeneuve, Montpellier (France); Davy, J.M. [Department of Cardiology, CHU Lapeyronie et A. Villeneuve, Montpellier (France); Rossi, M. [Department of Nuclear Medicine, CHU Lapeyronie et A. de Villeneuve, Montpellier (France)

    1995-11-01

    In this case report we present a patient with a recurrence of subacute bacterial infectious endocarditis (IE) complicating a transvenous endocardial pacemaker. Technetium-99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) labelled granulocytes were used for diagnosis and follow-up under medical treatment only, since surgical removal of the pacemaker lead was ruled out because of the general condition of the patient. Single-photon emission tomography (SPET) imaging displayed the active lesion previously suspected on echography. At the end of antibiotic therapy, SPET indicated a favourable disease outcome whereas echocardiographic abnormalities remained nearly unchanged. The medical treatment had eradicated the IE, and the patient did well for more than 1 year thereafter. (orig.)

  1. Endocardial Boundary Detection in Echocardiographic Images with an Improved Fast Marching Method%心超图中心内膜边缘检测改进的快速行进算法

    Institute of Scientific and Technical Information of China (English)

    严加勇; 庄天戈

    2003-01-01

    Objective To study a new computerized automatic method for endocardial boundary estimation and tracking in sequential echocardiographic images. Method Through analyzing the existing problems of the traditional fast marching method, the contour energy conception of the active contour model was introduced to improve the traditional fast marching mathematical model. Result The improved mathematical model was applied to sequential echocardiographic images and the experimental results showed that endocardial boundary can be accurately detected. Conclusion The introduction of contour energy conception enhances the stability and effectiveness while keeping the convergence velocity of the fast marching algorithm.%目的探讨一种对心超图中心脏内膜边缘进行检测的自动化方法.方法根据对传统快速行进算法中存在问题的分析研究,引入活动轮廓线模型中轮廓线能量概念以改进传统快速行进算法的数学模型.结果将改进的快速行进模型应用于心超图像中心脏内膜边缘检测,实验结果表明该方法能够准确地检测、跟踪出心脏内膜边缘. 结论轮廓线能量概念的引入提高了快速行进算法的稳定性和有效性,而且几乎不影响算法的收敛速度.

  2. 完全性心内膜垫缺损合并右室双出口的双心室修复%Biventricular refair for endocardial cushion defects with double outlet right ventricle

    Institute of Scientific and Technical Information of China (English)

    李富骊; 尤斌; 李平; 郑铁; 许李力; 徐屹; 刘硕

    2011-01-01

    目的 总结完全性心内膜垫缺损合并右室双出口双心室修复的经验.方法 2006年7月至209年11月对6例完全性心内膜垫缺损合并右室双出口病人采用双片法修补完全性心内膜垫缺损,人工血管补片作右心室内隧道,连接室间隔缺损与主动脉口,引导左心室血经内隧道进入主动脉;应用牛心包补片扩大右室流出道;肺动脉瓣环小者用带瓣补片跨环修补右室流出道;心室内隧道有可能阻塞右室流出道造成重度梗阻者,右室流出道与主肺动脉之间安置带瓣管道(Rastelli手术).结果 术后死亡1例,占16.6%,其余病例恢复良好.结论 完全性心内膜垫缺损合并右室双出口一期双心室修复可获得良好效果.%Objective Double-outlet right ventricle,which often associated with total anomalous pulmonary venous connection and complete endocardial cushion defects,has been considered a risk factor for biventricular repair procedure.To reviewed cases treated by biventricular repair for endocardial cushion defects with double outlet right ventricle.Methods From July to November of 2009,6 patients (3 males and 3 females) aged from 7 to 24 (16.17±5.98) years and with endocardial cushion defects and double outlet right ventricle underwent operation of biventricular repair The duration of follow-up ranged from 10 days to 2 years(median,16 months).Endocardial cushion defects were repaired with a 2-patch technique.The artificial vascular patch was implanted to connect the ventricular septal defects and the aorta for draining the blood stream from the left ventricle to the aorta.The other patch was used to repair the ostium primum atrial septal defects.Right ventricular outflow tract obstructions was released and reconstructed by transplanting a bovine pericardium patch.If the size of pulmonary valve annulus was far more below the normal,a transannular pericardial patch was used.Rastelli procedure with a valved conduit between the right

  3. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Iannicelli, Elsa; Di Renzo, Sara [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ferri, Mario [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Pilozzi, Emanuela [Department of Clinical and Molecular Sciences, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Di Girolamo, Marco; Sapori, Alessandra [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ziparo, Vincenzo [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); David, Vincenzo [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy)

    2014-07-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

  4. Sparing Sphincters and Laparoscopic Resection Improve Survival by Optimizing the Circumferential Resection Margin in Rectal Cancer Patients.

    Science.gov (United States)

    Keskin, Metin; Bayraktar, Adem; Sivirikoz, Emre; Yegen, Gülcin; Karip, Bora; Saglam, Esra; Bulut, Mehmet Türker; Balik, Emre

    2016-02-01

    The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors.Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann-Whitney U test and the Mantel-Cox log-rank sum test.A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics or surgical treatment between the patients who had positive CRM and who had negative CRM, but a higher positive CRM rate was observed in patients undergone abdominoperineal resection (APR) (P CRM status. Logistic regression analysis revealed that APR (P CRM status. Moreover, positive CRM was associated with decreased 5-year overall and disease-free survival (P = 0.002 and P = 0.004, respectively).This large single-institution series demonstrated that APR and open resection were independent predictive factors for positive CRM status in rectal cancer. Positive CRM independently decreased the 5-year overall and disease-free survival rates.

  5. The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

    KAUST Repository

    Chadwick, William W Jr

    2010-12-15

    The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45-60°) toward the caldera at the surface and more gently dipping (~12-14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another. © 2010 Springer-Verlag.

  6. Practical constraints on estimation of source extent with MEG beamformers

    OpenAIRE

    Hillebrand, Arjan; Barnes, Gareth R.

    2011-01-01

    We aimed to determine practical constraints on the estimation of the spatial extent of neuronal activation using MEG beamformers. Correct estimation of spatial extent is a pre-requisite for accurate models of electrical activity, allows one to estimate current density, and enables non-invasive monitoring of functional recovery following stroke. The output of an MEG beamformer is maximum when the correct source model is used, so that the spatial extent of a source can in principal be determine...

  7. 14 CFR 252.8 - Extent of smoking restrictions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Extent of smoking restrictions. 252.8... PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.8 Extent of smoking restrictions. The restrictions on smoking described in §§ 252.3 through 252.7 shall apply to all locations within the aircraft....

  8. 32 CFR 728.12 - Extent of care.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Extent of care. 728.12 Section 728.12 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL MEDICAL AND DENTAL CARE FOR... § 728.12 Extent of care. Members who are away from their duty stations or are on duty where there is...

  9. 基于直接数字合成技术用于心内膜三维标测的激励源设计%Excitation source design for endocardial three-dimensional mapping based on direct digital synthesis

    Institute of Scientific and Technical Information of China (English)

    陈中中; 田国强; 苏智剑; 郑伟

    2011-01-01

    BACKGROUND: The excitation source's design is precondition of detecting the catheter's position in endocardial three-dimensional (3D) mapping by low-frequency electric field.OBJECTIVE: To design an excitation source for endocardial 3D mapping with simple structure and high integration, furthermore,to test the performance of the excitation source through animal experiments.M ETHODS : Three channel different frequencies (28, 30, 32 kHz) sine voltage signals were generated based on the direct digital synthesis (DDS) technology and modularization design through three AD9851 chip controlled by single-chip microcomputer STC89C52. The excitation source's performance is analyzed by acquisition and processing the localization signal in animal right atrium.RESOULTS AND CONCLUSION: The animal experimental results show that three signals' current value can be stable at 1mA and the frequency errors are 0.054%, 0.097%, 0.056%, respectively, furthermore, voltage signals in three directions can be extracted from the mapping catheter's sampling data. The excitation source has little frequency error and higher constant-current performance, and therefore can satisfy the endocardial mapping requirements.%背景:低频电场定位方式下的心内膜三维标测技术中,激励源的设计是探测导管位置的前提.目的:旨在设计一种结构简单、集成度高、专用于心内膜三维标测的激励源,并通过动物实验对激励源性能进行测试分析.方法:基于直接数字合成技术,采用模块化设计,以单片机STC89C52控制三块直接数字合成芯片AD9851为核心,生成三路频率分别为28,30,32 kHz的1 mA正弦恒流信号.施加三路信号于动物体,采集并处理右心房内的定位信号数据,对激励源性能进行评价和分析.结果与结论:动物实验结果表明,三路信号的电流值均可稳定于1 mA,其频率误差分别为0.054%,0.097%及0.056%,同时标测导管采集数据正常,能够分离出3个方向的

  10. Practical constraints on estimation of source extent with MEG beamformers.

    Science.gov (United States)

    Hillebrand, Arjan; Barnes, Gareth R

    2011-02-14

    We aimed to determine practical constraints on the estimation of the spatial extent of neuronal activation using MEG beamformers. Correct estimation of spatial extent is a pre-requisite for accurate models of electrical activity, allows one to estimate current density, and enables non-invasive monitoring of functional recovery following stroke. The output of an MEG beamformer is maximum when the correct source model is used, so that the spatial extent of a source can in principal be determined through evaluation of different source models with the beamformer. Here, we simulated 275-channel MEG data using sources of varying spatial extents that followed the cortical geometry. These data were subsequently used to estimate the spatial extent of generic disc elements without knowledge of the underlying surface, and we compared these results to estimates based on cortical surface geometry (with and without error in surface location). We found that disc-shaped source models are too simplistic, particularly for areas with high curvature. For areas with low curvature spatial extent was underestimated, although on average there was a linear relationship between the true and estimated extent. In contrast, cortical surface models gave accurate predictions of spatial extent. However, adding small errors (>2 mm) to the estimated location of the cortical surface abolished this relationship between true and estimated extent, implying that accurate co-registration is needed with such models. Our results show that models exploiting surface information are necessary in order to model spatial extent and in turn current density, but in order to render such models applicable in practical situations, the accuracy of the cortical surface model itself needs to improve.

  11. Magnetic resonance-derived circumferential strain provides a superior and incremental assessment of improvement in contractile function in patients early after ST-segment elevation myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Dennis T.L.; Psaltis, Peter J. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); South Australian Health and Medical Research Institute (SAHMRI), Adelaide (Australia); Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia); Leong, Darryl P.; Weightman, Michael J.; Richardson, James D.; Worthley, Matthew I.; Worthley, Stephen G. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); Dundon, Benjamin K.; Leung, Michael C.H.; Meredith, Ian T. [Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia)

    2014-06-15

    We evaluate whether circumferential strain derived from grid-tagged CMR is a better method for assessing improvement in segmental contractile function after STEMI compared to late gadolinium enhancement (LGE). STEMI patients post primary PCI underwent baseline CMR (day 3) and follow-up (day 90). Cine, grid-tagged and LGE images were acquired. Baseline LGE infarct hyperenhancement was categorised as ≤25 %, 26-50 %, 51-75 % and >75 % hyperenhancement. The segmental baseline circumferential strain (CS) and circumferential strain rate (CSR) were calculated from grid-tagged images. Segments demonstrating an improvement in wall motion of ≥1 grade compared to baseline were regarded as having improved segmental contractile-function. Forty-five patients (aged 58 ± 12 years) and 179 infarct segments were analysed. A baseline CS cutoff of -5 % had sensitivity of 89 % and specificity of 70 % for detection of improvement in segmental-contractile-function. On receiver-operating characteristic analysis for predicting improvement in contractile function, AUC for baseline CS (0.82) compared favourably to LGE hyperenhancement (0.68), MVO (0.67) and baseline-CSR (0.74). On comparison of AUCs, baseline CS was superior to LGE hyperenhancement and MVO in predicting improvement in contractile function (P < 0.001). On multivariate-analysis, baseline CS was the independent predictor of improvement in segmental contractile function (P < 0.001). Grid-tagged CMR-derived baseline CS is a superior predictor of improvement in segmental contractile function, providing incremental value when added to LGE hyperenhancement and MVO following STEMI. (orig.)

  12. Circumferential decompression via the posterior approach for the surgical treatment of multilevel thoracic ossification of the posterior longitudinal ligaments: a single institution comparative study

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao; Zhu Bin; Liu Xiaoguang; Liu Zhongjun; Dang Gengting

    2014-01-01

    Background The treatment strategies for multilevel thoracic ossification of the posterior longitudinal ligaments (T-OPLL) were rarely reported.The aim of this study was to investigate the clinical outcomes and complications of circumferential decompression for multilevel T-OPLL and compare two different methods in the management of the OPLL (resection or floating).Methods Data of sequentially treated patients who received surgical treatment for thoracic spinal stenosis caused by multilevel T-OPLL from January 2005 to February 2012 were retrospectively reviewed.Based on the surgical approaches applied,the patients were divided into two groups.Group A consisted the patients who received posterior decompression and group B consisted the patients who received circumferential decompression via the posterior approach.Group B was further divided into two subgroups:subgroup 1 (the resection group) where the OPLL was completely resected and subgroup 2 (the floating group) where the OPLL was floated.Results A total of 49 patients were included in the study.Fourteen patients with single posterior decompression were included in group A and 35 patients who received circumferential decompression were included in group B.In group B,29 patients had complete resection of the ossified posterior longitudinal ligaments,while the other six underwent a flotation procedure.The follow-up data were available in 39 patients.Mean JOA scores improved from 5.4 ± 1.8 to 7.5 ± 2.8 in group A and from 3.7 ± 1.8 to 7.9 ± 2.4 in group B.The main complications included cerebrospinal fluid (CSF) leakage and postoperative neurologic deterioration (ND).Twenty-three of the 25 cases with postoperative CSF leakage achieved a complete recovery at the last follow-up and 12 of the 15 cases with ND achieved some neurological improvement at the last follow-up.Conclusions Circumferential decompression via the posterior approach is an effective surgical method for thoracic spinal stenosis caused by

  13. Does Trust Influence the Extent of Inter-Organizational Barter?

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    2014-01-01

    The 1999 World Business Environment Survey investigated, among many other things, the extent of inter-organizational barter in various countries. Reported values differed a lot, e.g. it was less than 1% in Hungary but more than 30% in neighboring Croatia. Since in many such contracts goods and....../or services are not exchanged at the same time, using barter tends to lead to a higher solvency risk than using money. Therefore, it is possible to theoretize that there is relation between the level of trust and the extent of barter use; namely that a higher level of trust leads to a higher extent...

  14. Stellwagen Bank National Marine Sanctuary - Internal Wave Analysis Spatial Extent

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This feature class contains the spatial extent of the internal wave analysis. This area of interest was defined in interests of time. A cusory review of the 66 SAR...

  15. Vapor Intrusion Facility Boundaries - Approximate Extent of Contamination

    Data.gov (United States)

    U.S. Environmental Protection Agency — Theses polygons represent the approximate extent of contamination for Vapor Intrusion facilities. Polygons for non-Federal Facility sites were updated in January,...

  16. Lumbopelvic parameters and the extent of lumbar fusion

    Directory of Open Access Journals (Sweden)

    Ha Son Nguyen

    2015-01-01

    Conclusion: The results imply that the extent of instrumentation, including the involvement of the sacrum, may not alter lumbopelvic parameters. This appears to argue against the idea that longer fusion constructs induce more stress on the pelvis and SI joint.

  17. Reconstructed North American Snow Extent, 1900-1993

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains reconstructed monthly North American snow extent values for November through March, 1900-1993. Investigators used a combination of satellite...

  18. A paediatric sudden death case of infant endocardial fibroelastosis and ventricular septal defect%小儿心内膜弹力纤维增生症并室间隔缺损猝死1例

    Institute of Scientific and Technical Information of China (English)

    郭娟宁; 汤政; 樊爱英

    2007-01-01

    心内膜弹力纤维增生症(endocardial fibroelastosis,EFE)是一种少见的心内膜心肌病,是婴幼儿心脏猝死的常见原因。临床上常突然发病,多因心力衰竭死亡。由于本病表现缺乏特异性,易与肺炎、心肌炎等混淆,临床诊断比较困难,尤其当合并其他先天性心脏病时。其表现可相互影响或被掩盖,误诊率较高。因此,常因临床上诊断不明而引起医疗纠纷。而有关EFE合并心脏畸形者引起的医疗纠纷,国内报道更少,现报道1例。

  19. Muscle transposition and circumferential vacuum-assisted closure to salvage the knee joint in transtibial amputation of the leg: case report.

    Science.gov (United States)

    Tuncer, Serdar; Karaca, Sinan

    2011-06-01

    Degloving injury is the avulsion of the skin off the underlying muscle and bone, which may also involve the latter structures in high-energy trauma. This study reports the case of a 33-year-old male patient who sustained a motorcycle accident and presented with hypovolemic shock, multiple fractures, and multiplanar degloving injury of the leg. The foot and distal leg was not salvageable, and a transtibial amputation with anterior transposition of the posterior compartment muscles was performed; however, a circumferential skin necrosis involving the stump and the knee joint occurred. The wound granulated rapidly using circumferential vacuum-assisted closure therapy and subsequently repaired with split thickness skin grafts. The authors found the topical negative pressure using the Vacuum Assisted Closure (VAC) technique Trademark KCI, Texas, USA, method to be helpful in the care of lower extremity degloving injury, enabling less frequent dressing changes and facilitating formation of granulation tissue with rapid preparation of the wound bed for salvage of the knee joint.

  20. Development and validation of a global dynamical wetlands extent scheme

    Directory of Open Access Journals (Sweden)

    T. Stacke

    2012-01-01

    Full Text Available In this study we present the development of the dynamical wetland extent scheme (DWES and its validation against present day wetland observations. The DWES is a simple, global scale hydrological scheme that solves the water balance of wetlands and estimates their extent dynamically. The extent depends on the balance of water flows in the wetlands and the slope distribution within the grid cells. In contrast to most models, the DWES is not directly calibrated against wetland extent observations. Instead, wetland affected river discharge data are used to optimize global parameters of the model. The DWES is not a complete hydrological model by itself but implemented into the Max Planck Institute – Hydrology Model (MPI-HM. However, it can be transferred into other models as well.

    For present climate, the model validation reveals a good agreement between the occurrence of simulated and observed wetlands on the global scale. The best result is achieved for the northern hemisphere where not only the wetland distribution pattern but also their extent is simulated reasonably well by the DWES. However, the wetland fraction in the tropical parts of South America and Central Africa is strongly overestimated. The simulated extent dynamics correlate well with monthly inundation variations obtained from satellite for most locations. Also, the simulated river discharge is affected by wetlands resulting in a delay and mitigation of peak flows. Compared to simulations without wetlands, we find locally increased evaporation and decreased river flow into the oceans due to the implemented wetland processes.

    In summary, the validation analysis demonstrates the DWES' ability to simulate the global distribution of wetlands and their seasonal variations. Thus, the dynamical wetland extent scheme can provide hydrological boundary conditions for wetland related studies. In future applications, the DWES should be implemented into an earth system model

  1. Systolic and diastolic myocardial mechanics in hypertrophic cardiomyopathy and their link to the extent of hypertrophy, replacement fibrosis and interstitial fibrosis.

    Science.gov (United States)

    Nucifora, Gaetano; Muser, Daniele; Gianfagna, Pasquale; Morocutti, Giorgio; Proclemer, Alessandro

    2015-12-01

    Aim of the present study was to investigate the relations between myocardial mechanics and the extent of hypertrophy and fibrosis in hypertrophic cardiomyopathy (HCM). Forty-five consecutive patients with HCM and 15 subjects without structural heart disease were included. Cardiac magnetic resonance with late gadolinium enhancement (LGE) imaging was performed to evaluate biventricular function, LV mass index and presence/extent of LGE, expression of replacement fibrosis. Myocardial T1 relaxation, a surrogate of interstitial fibrosis, was measured from Look-Locker sequence. Feature-tracking analysis was applied to LV basal, mid and apical short-axis images to assess systolic and diastolic global LV circumferential strain (CS) and strain rate (CSr). Peak systolic CS and CSr were significantly higher among HCM patients as compared to control subjects (p = 0.015 and p = 0.007, respectively). The ratio of peak CSr during early filling to peak systolic CSr was significantly lower among HCM patients (p = 0.002). At multivariate linear regression analysis, LV mass index (p < 0.001) and %LV LGE (p = 0.011) were significantly and independently related to peak systolic CS; LV mass index (p < 0.001) and %LV LGE (p = 0.023) were significantly and independently related to peak systolic CSr; %LV LGE (p = 0.021) and T1 ratio (p = 0.006) were significantly and independently related to the ratio of peak CSr during early filling to peak systolic CSr. LV systolic mechanics are enhanced and LV diastolic mechanics are impaired in HCM. Extent of hypertrophy and replacement fibrosis influence the LV systolic mechanics while extent of replacement fibrosis and interstitial fibrosis influence the LV diastolic mechanics.

  2. The 2014 high record of Antarctic sea ice extent

    Science.gov (United States)

    Massonnet, Francois; Guemas, Virginie; Fuckar, Neven; Doblas-Reyes, Francisco

    2016-04-01

    In September 2014, Antarctic sea ice extent exceeded the symbolic level of 20 million km²for the first time since 1978, when reliable satellite measurements became available. After the successive records of 2012 and 2013, sea ice extent in 2014 once again reinforced the positive trend observed since the late 1970s. We conduct here a dedicated study to elucidate the origins of a major, and perhaps the most intriguing, event that happened at our Poles recently. Observations, reanalyses and model results all point towards the important role of winds in modifying near-surface heat advection patterns around Antarctica. The role of pre-conditioning (summer conditions) is found to be of lesser importance. Finally, we find no evidence that anomalous freshwater forcing (from atmospheric or continental origin) could have explained the record extent of 2014.

  3. New Evaluation on the Preoxidation Extent of Different PAN Precursors

    Institute of Scientific and Technical Information of China (English)

    Wangxi ZHANG; Jie LIU; Jieying LIANG

    2004-01-01

    Structural changes in carbon fibers at each stage of, especially, preoxidation process are well known to play a great role in achieving the ultimate product quality. Differential scanning calorimetry (DSC), scanning electron microscope (SEM), density method and optical microscope were used to characterize the preoxidation extent. A conventional pproach, e.g., density aim, to evaluate the extent of preoxidation is not very exact. A DSC curve of a PAN precursor only can provide general information, major in the temperature regime of preoxidation reaction. However,the evaluation of a preoxidation extent, especially from conventional preoxidation temperature with a great span egime of 200~400℃, is put forward in this paper, in which the evolution of core/shell morphological structure is a kind of straightforward evidence.

  4. Extent, accuracy, and credibility of breastfeeding information on the Internet.

    Science.gov (United States)

    Shaikh, Ulfat; Scott, Barbara J

    2005-05-01

    Our objective was to test and describe a model for evaluating Websites related to breastfeeding. Forty Websites most likely to be accessed by the public were evaluated for extent, accuracy, credibility, presentation, ease of use, and adherence to ethical and medical Internet publishing standards. Extent and accuracy of Website content were determined by a checklist of critical information. The majority of Websites reviewed provided accurate information and complied with the International Code of Marketing of Breast-milk Substitutes. Approximately half the Websites complied with standards of medical Internet publishing. While much information on breastfeeding on the Internet is accurate, there is wide variability in the extent of information, usability of Websites, and compliance with standards of medical Internet publishing. Results of this study may be helpful to health care professionals as a model for evaluating breastfeeding-related Websites and to highlight considerations when recommending or designing Websites.

  5. Development and evaluation of a global dynamical wetlands extent scheme

    Directory of Open Access Journals (Sweden)

    T. Stacke

    2012-08-01

    Full Text Available In this study we present the development of the dynamical wetland extent scheme (DWES and evaluate its skill to represent the global wetland distribution. The DWES is a simple, global scale hydrological scheme that solves the water balance of wetlands and estimates their extent dynamically. The extent depends on the balance of water flows in the wetlands and the slope distribution within the grid cells. In contrast to most models, the DWES is not directly calibrated against wetland extent observations. Instead, wetland affected river discharge data are used to optimise global parameters of the model. The DWES is not a complete hydrological model by itself but implemented into the Max Planck Institute – Hydrology Model (MPI-HM. However, it can be transferred into other models as well.

    For present climate, the model evaluation reveals a good agreement for the spatial distribution of simulated wetlands compared to different observations on the global scale. The best results are achieved for the Northern Hemisphere where not only the wetland distribution pattern but also their extent is simulated reasonably well by the DWES. However, the wetland fraction in the tropical parts of South America and Central Africa is strongly overestimated. The simulated extent dynamics correlate well with monthly inundation variations obtained from satellites for most locations. Also, the simulated river discharge is affected by wetlands resulting in a delay and mitigation of peak flows. Compared to simulations without wetlands, we find locally increased evaporation and decreased river flow into the oceans due to the implemented wetland processes.

    In summary, the evaluation demonstrates the DWES' ability to simulate the distribution of wetlands and their seasonal variations for most regions. Thus, the DWES can provide hydrological boundary conditions for wetland related studies. In future applications, the DWES may be implemented into an Earth

  6. The extent of emphysema in patients with COPD

    DEFF Research Database (Denmark)

    Shaker, Saher Burhan; Stavngaard, Trine; Hestad, Marianne

    2009-01-01

    BACKGROUND AND AIMS: The global initiative for COPD (GOLD) adopted the degree of airway obstruction as a measure of the severity of the disease. The objective of this study was to apply CT to assess the extent of emphysema in patients with chronic obstructive pulmonary disease (COPD) and relate...... this extent to the GOLD stage of airway obstruction. MATERIALS AND METHODS: We included 209 patients with COPD. COPD was defined as FEV(1)/FVC or=20 pack-years. Patients were assessed by lung function...... increases with increasing severity of COPD and most patients with COPD have emphysema. Tissue destruction by emphysema is therefore an important determinant of disease severity in COPD....

  7. Real-time flood extent maps based on social media

    Science.gov (United States)

    Eilander, Dirk; van Loenen, Arnejan; Roskam, Ruud; Wagemaker, Jurjen

    2015-04-01

    During a flood event it is often difficult to get accurate information about the flood extent and the people affected. This information is very important for disaster risk reduction management and crisis relief organizations. In the post flood phase, information about the flood extent is needed for damage estimation and calibrating hydrodynamic models. Currently, flood extent maps are derived from a few sources such as satellite images, areal images and post-flooding flood marks. However, getting accurate real-time or maximum flood extent maps remains difficult. With the rise of social media, we now have a new source of information with large numbers of observations. In the city of Jakarta, Indonesia, the intensity of unique flood related tweets during a flood event, peaked at 8 tweets per second during floods in early 2014. A fair amount of these tweets also contains observations of water depth and location. Our hypothesis is that based on the large numbers of tweets it is possible to generate real-time flood extent maps. In this study we use tweets from the city of Jakarta, Indonesia, to generate these flood extent maps. The data-mining procedure looks for tweets with a mention of 'banjir', the Bahasa Indonesia word for flood. It then removes modified and retweeted messages in order to keep unique tweets only. Since tweets are not always sent directly from the location of observation, the geotag in the tweets is unreliable. We therefore extract location information using mentions of names of neighborhoods and points of interest. Finally, where encountered, a mention of a length measure is extracted as water depth. These tweets containing a location reference and a water level are considered to be flood observations. The strength of this method is that it can easily be extended to other regions and languages. Based on the intensity of tweets in Jakarta during a flood event we can provide a rough estimate of the flood extent. To provide more accurate flood extend

  8. Circumferential lesion formation around the pulmonary veins in the left atrium with focused ultrasound using a 2D-array endoesophageal device: a numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Pichardo, Samuel; Hynynen, Kullervo [Imaging Research-Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Room C713, Toronto, ON M4N 3M5 (Canada)

    2007-08-21

    Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia affecting humans. The electrical isolation by ablation of the pulmonary veins (PVs) in the left atrium (LA) of the heart has been proven as an effective cure of AF. The ablation consists mainly in the formation of a localized circumferential thermal coagulation of the cardiac tissue surrounding the PVs. In the present numerical study, the feasibility of producing the required circumferential lesion with an endoesophageal ultrasound probe is investigated. The probe operates at 1 MHz and consists of a 2D array with enough elements (114 x 20) to steer the acoustic field electronically in a volume comparable to the LA. Realistic anatomical conditions of the thorax were considered from the segmentation of histological images of the thorax. The cardiac muscle and the blood-filled cavities in the heart were identified and considered in the sound propagation and thermal models. The influence of different conditions of the thermal sinking in the LA chamber was also studied. The circumferential ablation of the PVs was achieved by the sum of individual lesions induced with the proposed device. Different scenarios of lesion formation were considered where ultrasound exposures (1, 2, 5 and 10 s) were combined with maximal peak temperatures (60, 70 and 80 {sup 0}C). The results of this numerical study allowed identifying the limits and best conditions for controlled lesion formation in the LA using the proposed device. A controlled situation for the lesion formation surrounding the PVs was obtained when the targets were located within a distance from the device in the range of 26 {+-} 7 mm. When combined with a maximal temperature of 70 {sup 0}C and an exposure time between 5 and 10 s, this distance ensured preservation of the esophageal structures, controlled lesion formation and delivery of an acoustic intensity at the transducer surface that is compatible with existing materials. With a peak

  9. Extent and application of patient diaries in Austria

    DEFF Research Database (Denmark)

    Heindl, Patrik; Bachlechner, Adelbert; Nydahl, Peter

    2017-01-01

    BACKGROUND: Diaries written for patients in the intensive care unit (ICU) are offered in many European countries. In Austria, ICU diaries have been relatively unknown, but since 2012, they have started to emerge. AIM: The aim of this study was to explore the extent and application of ICU diaries ...

  10. The Extent and Nature of Bullying in a Christian School

    Science.gov (United States)

    Hazeltine, Brian C.; Hernandez, David A.

    2015-01-01

    Bullying is a problem that has been studied in schools worldwide, but there is little research on bullying within Christian schools, a dearth which may stem from the assumption that Christian schools teach character traits that are inimical to bullying. Yet understanding the extent and nature of bullying in Christian schools may lead to a better…

  11. Spatial extent in demographic research - approach and problems

    Directory of Open Access Journals (Sweden)

    Knežević Aleksandar

    2015-01-01

    Full Text Available One of the starting methodological problems in demographic research is the definition of spatial extent, which mostly doesn’t correspond to spatial extent already defined by different levels of administrative-territorial unitsthat are used for distribution of usable statistical data. That’s why determining the spatial extent of a demographic research is closely tied with administrative-territorial division of the territory that is being researched, wherein the fact that differentiation of demographic phenomena and processes cannot be the only basis of setting the principles of regionalization must be strictly acknowledged. This problem is particularly common in historical demographic analyses of geographically determined wholes, which are in administratively-territorial sense represented by one or more smaller territorial units, with their borders changing through the history, which directly affects comparability of the statistical data, and makes it considerably more difficult to track demographic change through longer time intervals. The result of these efforts is usually a solution based on a compromise which enables us to examine the dynamics of population change with little deviation from already defined borders of regional geographic wholes. For that reason in this paper the problem of defining spatial extent in demographic research is examined trough several different approaches in case of Eastern Serbia, as a geographically determined region, a historic area, a spatially functioning whole and as a statistical unit for demographic research, with no judgment calls in regard to any of the regionalization principles. [Projekat Ministarstva nauke Republike Srbije, br. III 47006

  12. The Extent and Nature of Bullying in a Christian School

    Science.gov (United States)

    Hazeltine, Brian

    2012-01-01

    Bullying is a problem that has been studied in schools worldwide, but there is little research on bullying within Christian schools, a dearth which may stem from the assumption that Christian schools teach character traits that are inimical to bullying. Yet understanding the extent and nature of bullying in Christian schools may lead to a better…

  13. 45 CFR 400.202 - Extent of Federal funding.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Extent of Federal funding. 400.202 Section 400.202... CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Federal Funding Federal Funding for Expenditures for Determining Eligibility and Providing Assistance and Services §...

  14. 40 CFR 35.3015 - Extent of State responsibilities.

    Science.gov (United States)

    2010-07-01

    ... required before and after grant award and to perform all construction grant review and management... of waste treatment construction grant projects for small communities. The State, with the approval of... ASSISTANCE STATE AND LOCAL ASSISTANCE Construction Grants Program Delegation to States § 35.3015 Extent...

  15. 29 CFR 1975.3 - Extent of coverage.

    Science.gov (United States)

    2010-07-01

    ...) COVERAGE OF EMPLOYERS UNDER THE WILLIAMS-STEIGER OCCUPATIONAL SAFETY AND HEALTH ACT OF 1970 § 1975.3 Extent of coverage. (a) Section 2(b) of the Williams-Steiger Occupational Safety and Health Act (Public Law... exercise of its powers to regulate commerce among the several States and with foreign nations and...

  16. The Extent of Educational Technology's Influence on Contemporary Educational Practices

    OpenAIRE

    Kim, Bradford-Watts

    2005-01-01

    This paper investigates how advances in educational technologies have influenced contemporary educational practices.It discusses the nature of educational technology, the limitations imposed by the digital divide and other factors of uptake, and the factors leading to successful implementation of educational technologies.The extent of influence is then discussed,together with the probable implications for educational sites for the future.

  17. To What Extent Do Gestalt Grouping Principles Influence Tactile Perception?

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2011-01-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli.…

  18. Is crack branching under shear loading caused by shear fracture? ——A critical review on maximum circumferential stress theory

    Institute of Scientific and Technical Information of China (English)

    孙宗颀

    2001-01-01

    When a crack is subjected to shear force, crack branching usually occurs. Theoretical study shows that the crack branching under shear loading is caused by tensile stress, but not caused by shear fracture. The co-plane shear fracture could be obtained if compressive stress with given direction is applied to the specimen, subsequently, calculated shear fracture toughness, KⅡ C, is larger than KⅠ C. A prerequisite of possible occurrence of mode Ⅱ fracture was proposed. The study of shear fracture shows that the maximum circumferential stress theory considered its criterion as a parametric equation of a curve in KⅠ, KⅡ plane is incorrect; the predicted ratio KⅡ C/KⅠ C=0.866 is incorrect too.

  19. Self-Expandable Stent for Repairing Coarctation of the Left-Circumferential Aortic Arch with Right-sided Descending Aorta and Aberrant Right Subclavian Artery with Kommerell's Aneurysm.

    Science.gov (United States)

    Khajali, Zahra; Sanati, Hamid Reza; Pouraliakbar, Hamidreza; Mohebbi, Bahram; Aeinfar, Kamran; Zolfaghari, Reza

    2017-01-01

    Endovascular treatment offers a great advantage in the management of main arteries stenoses. However, simultaneous presence of a group of anomalies may complicate the situation. Here we present a case of 21-year-old man with aortic coarctation. Radiographic imaging and angiography demonstrated aortic coarctation of the left-circumferential aortic arch, right-sided descending aorta, and Kommerell's diverticulum at the origin of right subclavian artery. These anomalies have rarely been reported to concurrently exist in the same case and the treatment is challenging. Percutaneous treatment for repair of aortic coarctation was successfully performed with deployment of self-expanding nitinol stents. Follow-up demonstrated the correction of blood pressure and improvement of the symptoms. It appears that deployment of self-expandable nitinol stents present a viable option for the management of coarcted aorta in patients having all or some of these anomalies together.

  20. Activity of daptomycin or linezolid in combination with rifampin or gentamicin against biofilm-forming Enterococcus faecalis or E. faecium in an in vitro pharmacodynamic model using simulated endocardial vegetations and an in vivo survival assay using Galleria mellonella larvae.

    Science.gov (United States)

    Luther, Megan K; Arvanitis, Marios; Mylonakis, Eleftherios; LaPlante, Kerry L

    2014-08-01

    Enterococci are the third most frequent cause of infective endocarditis. A high-inoculum stationary-phase in vitro pharmacodynamic model with simulated endocardial vegetations was used to simulate the human pharmacokinetics of daptomycin at 6 or 10 mg/kg of body weight/day or linezolid at 600 mg every 12 h (q12h), alone or in combination with gentamicin at 1.3 mg/kg q12h or rifampin at 300 mg q8h or 900 mg q24h. Biofilm-forming, vancomycin-susceptible Enterococcus faecalis and vancomycin-resistant Enterococcus faecium (vancomycin-resistant enterococcus [VRE]) strains were tested. At 24, 48, and 72 h, all daptomycin-containing regimens demonstrated significantly more activity (decline in CFU/g) than any linezolid-containing regimen against biofilm-forming E. faecalis. The addition of gentamicin to daptomycin (at 6 or 10 mg/kg) in the first 24 h significantly improved bactericidal activity. In contrast, the addition of rifampin delayed the bactericidal activity of daptomycin against E. faecalis, and the addition of rifampin antagonized the activities of all regimens against VRE at 24 h. Also, against VRE, the addition of gentamicin to linezolid at 72 h improved activity and was bactericidal. Rifampin significantly antagonized the activity of linezolid against VRE at 72 h. In in vivo Galleria mellonella survival assays, linezolid and daptomycin improved survival. Daptomycin at 10 mg/kg improved survival significantly over that with linezolid against E. faecalis. The addition of gentamicin improved the efficacy of daptomycin against E. faecalis and those of linezolid and daptomycin against VRE. We conclude that in enterococcal infection models, daptomycin has more activity than linezolid alone. Against biofilm-forming E. faecalis, the addition of gentamicin in the first 24 h causes the most rapid decline in CFU/g. Of interest, the addition of rifampin decreased the activity of daptomycin against both E. faecalis and VRE.

  1. Terror And Territory: The Spatial Extent Of Sovereignty

    Directory of Open Access Journals (Sweden)

    Márcio José Mendonça

    2014-07-01

    Full Text Available The text consists of one review of the book Terror and territory: the spatial extent of sovereignty (2009 English geographer Stuart Elden. The work provides an approach of territory as the spatial extent of political sovereignty, which conceives importance to the notion of terror as a fundamental quality of the territory as a form punitive of control executed within the recognized boundaries, through use the monopoly of legitimate violence that state power has. However, the territorial sovereignty that evokes modern state, Elden argues, has become contingent after the terrorist attacks of September 11 (2001, when the USA unleashed a policy of “war on terror”, unilaterally applying the law of international intervention.

  2. The spatial extent of the effect of foreclosures on crime.

    Science.gov (United States)

    Payton, Seth B; Stucky, Thomas D; Ottensmann, John R

    2015-01-01

    Although neighborhood stability has long been considered a substantial determinant of crime, foreclosures have not been the subject of concerted research among criminologists until recently. A number of recent studies have examined the linkage between home foreclosures and crime. Though generally finding a significant relationship, studies have used different approaches and units of analysis. This variation led us to examine the spatial extent to which foreclosures affect a relatively small surrounding area. In this paper, we consider the spatial extent of the foreclosure effect on crime by estimating fixed effect negative binomial models using geocoded UCR data for 2003-2008 and foreclosure data to predict crime counts using the number of foreclosures within various small area radii. Results show that, independently and jointly, foreclosures are a predictor of crime up to at least a distance of 2250 feet. Importantly, that effect declines with distance. We conclude with a discussion of the implications of those findings.

  3. The Extent of Students’ Initiation of Ideas in The Classroom

    OpenAIRE

    Oranu Philomena Chika

    2012-01-01

    This study sought to identify the extent of students’ initiation of ideas in the classroom using three classroom interaction techniques. All senior secondary schools in Port Harcourt Local Government Area, Rivers State, Nigeria constituted the population. One research question guided the study. One hypothesis was tested and analysed using chi square statistics. The population is made up of 10,983 students 496 teachers. The sample is made up of 1098 students and 12 teachers. SS1 and SS11 stude...

  4. The extent of strangeness equilibration in quark gluon plasma

    Indian Academy of Sciences (India)

    Dipali Pal; Abhijit Sen; Munshi Golam Mustafa; Dinesh Kumar Srivastava

    2003-05-01

    The evolution and production of strangeness from chemically equilibrating and transversely expanding quark gluon plasma which may be formed in the wake of relativistic heavy-ion collisions is studied with initial conditions obtained from the self screened parton cascade (SSPC) model. The extent of partonic equilibration increases almost linearly with the square of the initial energy density, which can then be scaled with the number of participants.

  5. Assessing the potential global extent of SWOT river discharge observations

    Science.gov (United States)

    Pavelsky, Tamlin M.; Durand, Michael T.; Andreadis, Konstantinos M.; Beighley, R. Edward; Paiva, Rodrigo C. D.; Allen, George H.; Miller, Zachary F.

    2014-11-01

    Despite its importance as a major element of the global hydrologic cycle, runoff remains poorly constrained except at the largest spatial scales due to limitations of the global stream gauge network and inadequate data sharing. Efforts using remote sensing to infer runoff from discharge estimates are limited by characteristics of present-day sensors. The proposed Surface Water and Ocean Topography (SWOT) mission, a joint project between the United States and France, aims to substantially improve space-based estimates of river discharge. However, the extent of rivers observable by SWOT, likely limited to those wider than 50-100 m, remains unknown. Here, we estimate the extent of SWOT river observability globally using a downstream hydraulic geometry (DHG) approach combining basin areas from the Hydro1k and Hydrosheds elevation products, discharge from the Global Runoff Data Centre (GRDC), and width estimates from a global width-discharge relationship. We do not explicitly consider SWOT-specific errors associated with layover and other phenomena in this analysis, although they have been considered in formulation of the 50-100 m width thresholds. We compare the extent of SWOT-observable rivers with GRDC and USGS gauge datasets, the most complete datasets freely available to the global scientific community. In the continental US, SWOT would match USGS river basin coverage only at large scales (>25,000 km2). Globally, SWOT would substantially improve on GRDC observation extent: SWOT observation of 100 m (50 m) rivers will allow discharge estimation in >60% of 50,000 km2 (10,000 km2) river basins. In contrast, the GRDC observes fewer than 30% (15%) of these basins. SWOT could improve characterization of global runoff processes, especially with a 50 m observability threshold, but in situ gauge data remains essential and must be shared more freely with the international scientific community.

  6. Estimating the extent of vaccine-derived poliovirus infection.

    Directory of Open Access Journals (Sweden)

    Alison Wringe

    Full Text Available BACKGROUND: Eight outbreaks of paralytic polio attributable to circulating vaccine-derived poliovirus (cVDPV have highlighted the risks associated with oral poliovirus vaccine (OPV use in areas of low vaccination coverage and poor hygiene. As the Polio Eradication Initiative enters its final stages, it is important to consider the extent to which these viruses spread under different conditions, so that appropriate strategies can be devised to prevent or respond to future cVDPV outbreaks. METHODS AND FINDINGS: This paper examines epidemiological (temporal, geographic, age, vaccine history, social group, ascertainment, and virological (type, genetic diversity, virulence parameters in order to infer the numbers of individuals likely to have been infected in each of these cVDPV outbreaks, and in association with single acute flaccid paralysis (AFP cases attributable to VDPVs. Although only 114 virologically-confirmed paralytic cases were identified in the eight cVDPV outbreaks, it is likely that a minimum of hundreds of thousands, and more likely several million individuals were infected during these events, and that many thousands more have been infected by VDPV lineages within outbreaks which have escaped detection. CONCLUSIONS: Our estimates of the extent of cVDPV circulation suggest widespread transmission in some countries, as might be expected from endemic wild poliovirus transmission in these same settings. These methods for inferring extent of infection will be useful in the context of identifying future surveillance needs, planning for OPV cessation and preparing outbreak response plans.

  7. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    Science.gov (United States)

    Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

    2012-01-01

    A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization.

  8. Exploring the Origin, Extent, and Future of Life

    Science.gov (United States)

    Bertka, Constance M.

    2009-09-01

    1. Astrobiology in societal context Constance Bertka; Part I. Origin of Life: 2. Emergence and the experimental pursuit of the origin of life Robert Hazen; 3. From Aristotle to Darwin, to Freeman Dyson: changing definitions of life viewed in historical context James Strick; 4. Philosophical aspects of the origin-of-life problem: the emergence of life and the nature of science Iris Fry; 5. The origin of terrestrial life: a Christian perspective Ernan McMullin; 6. The alpha and the omega: reflections on the origin and future of life from the perspective of Christian theology and ethics Celia Deane-Drummond; Part II. Extent of Life: 7. A biologist's guide to the Solar System Lynn Rothschild; 8. The quest for habitable worlds and life beyond the Solar System Carl Pilcher; 9. A historical perspective on the extent and search for life Steven J. Dick; 10. The search for extraterrestrial life: epistemology, ethics, and worldviews Mark Lupisella; 11. The implications of discovering extraterrestrial life: different searches, different issues Margaret S. Race; 12. God, evolution, and astrobiology Cynthia S. W. Crysdale; Part III. Future of Life: 13. Planetary ecosynthesis on Mars: restoration ecology and environmental ethics Christopher P. McKay; 14. The trouble with intrinsic value: an ethical primer for astrobiology Kelly C. Smith; 15. God's preferential option for life: a Christian perspective on astrobiology Richard O. Randolph; 16. Comparing stories about the origin, extent, and future of life: an Asian religious perspective Francisca Cho; Index.

  9. Extent of the Immirzi Ambiguity in Quantum General Relativity

    CERN Document Server

    Mena-Marugán, G A

    2002-01-01

    The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism based on each of these canonical sets leads to different predictions. This phenomenon is called the Immirzi ambiguity. It has been recently argued that this ambiguity could be generalized to the extent of a spatially dependent function, instead of a parameter. This would ruin the predictability of loop quantum gravity. We prove that such expectations are not realized, so that the Immirzi ambiguity introduces exclusively a freedom in the choice of a real number.

  10. Detecting the Extent of Eutectoid Transformation in U-10Mo

    Energy Technology Data Exchange (ETDEWEB)

    Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jana, Saumyadeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McInnis, Colleen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lombardo, Nicholas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sweet, Lucas E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Manandhar, Sandeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-31

    During eutectoid transformation of U-10Mo alloy, uniform metastable γ UMo phase is expected to transform to a mixture of α-U and γ’-U2Mo phase. The presence of transformation products in final U-10Mo fuel, especially the α phase is considered detrimental for fuel irradiation performance, so it is critical to accurately evaluate the extent of transformation in the final U-10Mo alloy. This phase transformation can cause a volume change that induces a density change in final alloy. To understand this density and volume change, we developed a theoretical model to calculate the volume expansion and resultant density change of U-10Mo alloy as a function of the extent of eutectoid transformation. Based on the theoretically calculated density change for 0 to 100% transformation, we conclude that an experimental density measurement system will be challenging to employ to reliably detect and quantify the extent of transformation. Subsequently, to assess the ability of various methods to detect the transformation in U-10Mo, we annealed U-10Mo alloy samples at 500°C for various times to achieve in low, medium, and high extent of transformation. After the heat treatment at 500°C, the samples were metallographically polished and subjected to optical microscopy and x-ray diffraction (XRD) methods. Based on our assessment, optical microscopy and image processing can be used to determine the transformed area fraction, which can then be correlated with the α phase volume fraction measured by XRD analysis. XRD analysis of U-10Mo aged at 500°C detected only α phase and no γ’ was detected. To further validate the XRD results, atom probe tomography (APT) was used to understand the composition of transformed regions in U-10Mo alloys aged at 500°C for 10 hours. Based on the APT results, the lamellar transformation product was found to comprise α phase with close to 0 at% Mo and γ phase with 28–32 at% Mo, and the Mo concentration was highest at the

  11. The Extent of Students’ Reponses in the Classroom

    OpenAIRE

    Oranu Philomena Chika

    2012-01-01

    This study sought to identify the extent of students’ responses in the classroom using three classroom interaction techniques. One research question guided the study. One hypothesis was tested and analysed using chi square statistics. The population is made up of 10,983 students 496 teachers. The sample is made up of 1098 students and 12 teachers. SS1 and SS11 students in three public schools were used for the study. Six classroom were used; three in SS1 and three in SS11 respectively. Six te...

  12. Integrating remotely sensed surface water extent into continental scale hydrology

    Science.gov (United States)

    Revilla-Romero, Beatriz; Wanders, Niko; Burek, Peter; Salamon, Peter; de Roo, Ad

    2016-12-01

    In hydrological forecasting, data assimilation techniques are employed to improve estimates of initial conditions to update incorrect model states with observational data. However, the limited availability of continuous and up-to-date ground streamflow data is one of the main constraints for large-scale flood forecasting models. This is the first study that assess the impact of assimilating daily remotely sensed surface water extent at a 0.1° × 0.1° spatial resolution derived from the Global Flood Detection System (GFDS) into a global rainfall-runoff including large ungauged areas at the continental spatial scale in Africa and South America. Surface water extent is observed using a range of passive microwave remote sensors. The methodology uses the brightness temperature as water bodies have a lower emissivity. In a time series, the satellite signal is expected to vary with changes in water surface, and anomalies can be correlated with flood events. The Ensemble Kalman Filter (EnKF) is a Monte-Carlo implementation of data assimilation and used here by applying random sampling perturbations to the precipitation inputs to account for uncertainty obtaining ensemble streamflow simulations from the LISFLOOD model. Results of the updated streamflow simulation are compared to baseline simulations, without assimilation of the satellite-derived surface water extent. Validation is done in over 100 in situ river gauges using daily streamflow observations in the African and South American continent over a one year period. Some of the more commonly used metrics in hydrology were calculated: KGE', NSE, PBIAS%, R2, RMSE, and VE. Results show that, for example, NSE score improved on 61 out of 101 stations obtaining significant improvements in both the timing and volume of the flow peaks. Whereas the validation at gauges located in lowland jungle obtained poorest performance mainly due to the closed forest influence on the satellite signal retrieval. The conclusion is that

  13. On the Extent CLT Applied in a College Classroom

    Institute of Scientific and Technical Information of China (English)

    涂红芹

    2010-01-01

    To what content is Communicative Language Teaching (CLT) likely to meet the needs of learners of English in China? It's a question still under debate,under discussion,having generated much interest in this field.By analyzing the development of CLT abroad and home,the comparison of EFL and ESL,the challenges and opportunities we meet in the application of CLT,the extent to which CLT is likely to meet the needs of learners in China is further discussed.

  14. Extent of the Immirzi ambiguity in quantum general relativity

    Energy Technology Data Exchange (ETDEWEB)

    Marugan, Guillermo A Mena [Centro de Fisica Miguel A Catalan, IMAFF, CSIC, Serrano 121, 28006 Madrid (Spain)

    2002-04-21

    The Ashtekar-Barbero formulation of general relativity admits a one-parameter family of canonical transformations that preserves the expressions of the Gauss and diffeomorphism constraints. The loop quantization of the connection formalism based on each of these canonical sets leads to different predictions. This phenomenon is called the Immirzi ambiguity. It has been recently argued that this ambiguity could be generalized to the extent of a spatially dependent function instead of a parameter. This would ruin the predictability of loop quantum gravity. We prove that such expectations are not realized, so that the Immirzi ambiguity introduces exclusively a freedom in the choice of a real number. (letter to the edit0008.

  15. Integrating remotely sensed surface water extent into continental scale hydrology.

    Science.gov (United States)

    Revilla-Romero, Beatriz; Wanders, Niko; Burek, Peter; Salamon, Peter; de Roo, Ad

    2016-12-01

    In hydrological forecasting, data assimilation techniques are employed to improve estimates of initial conditions to update incorrect model states with observational data. However, the limited availability of continuous and up-to-date ground streamflow data is one of the main constraints for large-scale flood forecasting models. This is the first study that assess the impact of assimilating daily remotely sensed surface water extent at a 0.1° × 0.1° spatial resolution derived from the Global Flood Detection System (GFDS) into a global rainfall-runoff including large ungauged areas at the continental spatial scale in Africa and South America. Surface water extent is observed using a range of passive microwave remote sensors. The methodology uses the brightness temperature as water bodies have a lower emissivity. In a time series, the satellite signal is expected to vary with changes in water surface, and anomalies can be correlated with flood events. The Ensemble Kalman Filter (EnKF) is a Monte-Carlo implementation of data assimilation and used here by applying random sampling perturbations to the precipitation inputs to account for uncertainty obtaining ensemble streamflow simulations from the LISFLOOD model. Results of the updated streamflow simulation are compared to baseline simulations, without assimilation of the satellite-derived surface water extent. Validation is done in over 100 in situ river gauges using daily streamflow observations in the African and South American continent over a one year period. Some of the more commonly used metrics in hydrology were calculated: KGE', NSE, PBIAS%, R(2), RMSE, and VE. Results show that, for example, NSE score improved on 61 out of 101 stations obtaining significant improvements in both the timing and volume of the flow peaks. Whereas the validation at gauges located in lowland jungle obtained poorest performance mainly due to the closed forest influence on the satellite signal retrieval. The conclusion is that

  16. The International Extent and Elasticity of Lifestyle Television

    DEFF Research Database (Denmark)

    Jensen, Pia Majbritt

    2008-01-01

    of ways, catering for local broadcasters’ image and target groups, local markets’ competitive conditions, media regulations, and history. This article investigates the international extent of the genre and looks into possible explanations for its Anglophone and Northern European bias. Subsequently...... programming is still produced very differently within this region according to the media systemic conditions of the specific national TV markets and the specific broadcasters and channels in question. As such, the lifestyle genre is indeed tremendously flexible and elastic and can be used in a diverse number...

  17. Spatial Database Management System of China Geological Survey Extent

    Institute of Scientific and Technical Information of China (English)

    Chen Jianguo; Chen Zhijun; Wang Quanming; Fang Yiping

    2003-01-01

    The spatial database management system of China geological survey extent is a social service system. Its aim is to help the government and the whole social public to expediently use the spatial database, such as querying, indexing, mapping and product outputting. The management system has been developed based on MAPGIS6. x SDK and Visual C++, considering the spatial database contents and structure and the requirements of users. This paper introduces the software structure, the data flow chart and some key techniques of software development.

  18. Corticocortical feedback increases the spatial extent of normalization.

    Science.gov (United States)

    Nassi, Jonathan J; Gómez-Laberge, Camille; Kreiman, Gabriel; Born, Richard T

    2014-01-01

    Normalization has been proposed as a canonical computation operating across different brain regions, sensory modalities, and species. It provides a good phenomenological description of non-linear response properties in primary visual cortex (V1), including the contrast response function and surround suppression. Despite its widespread application throughout the visual system, the underlying neural mechanisms remain largely unknown. We recently observed that corticocortical feedback contributes to surround suppression in V1, raising the possibility that feedback acts through normalization. To test this idea, we characterized area summation and contrast response properties in V1 with and without feedback from V2 and V3 in alert macaques and applied a standard normalization model to the data. Area summation properties were well explained by a form of divisive normalization, which computes the ratio between a neuron's driving input and the spatially integrated activity of a "normalization pool." Feedback inactivation reduced surround suppression by shrinking the spatial extent of the normalization pool. This effect was independent of the gain modulation thought to mediate the influence of contrast on area summation, which remained intact during feedback inactivation. Contrast sensitivity within the receptive field center was also unaffected by feedback inactivation, providing further evidence that feedback participates in normalization independent of the circuit mechanisms involved in modulating contrast gain and saturation. These results suggest that corticocortical feedback contributes to surround suppression by increasing the visuotopic extent of normalization and, via this mechanism, feedback can play a critical role in contextual information processing.

  19. Typical magnitude and spatial extent of crowding in autism.

    Science.gov (United States)

    Freyberg, Jan; Robertson, Caroline E; Baron-Cohen, Simon

    2016-01-01

    Enhanced spatial processing of local visual details has been reported in individuals with autism spectrum conditions (ASC), and crowding is postulated to be a mechanism that may produce this ability. However, evidence for atypical crowding in ASC is mixed, with some studies reporting a complete lack of crowding in autism and others reporting a typical magnitude of crowding between individuals with and without ASC. Here, we aim to disambiguate these conflicting results by testing both the magnitude and the spatial extent of crowding in individuals with ASC (N = 25) and age- and IQ-matched controls (N = 23) during an orientation discrimination task. We find a strong crowding effect in individuals with and without ASC, which falls off as the distance between target and flanker is increased. Both the magnitude and the spatial range of this effect were comparable between individuals with and without ASC. We also find typical (uncrowded) orientation discrimination thresholds in individuals with ASC. These findings suggest that the spatial extent of crowding is unremarkable in ASC, and is therefore unlikely to account for the visual symptoms reported in individuals with the diagnosis.

  20. The Extent of Students’ Reponses in the Classroom

    Directory of Open Access Journals (Sweden)

    Oranu Philomena Chika

    2012-01-01

    Full Text Available This study sought to identify the extent of students’ responses in the classroom using three classroom interaction techniques. One research question guided the study. One hypothesis was tested and analysed using chi square statistics. The population is made up of 10,983 students 496 teachers. The sample is made up of 1098 students and 12 teachers. SS1 and SS11 students in three public schools were used for the study. Six classroom were used; three in SS1 and three in SS11 respectively. Six teachers taught SS1 and six teachers taught SS11 using a technique (Flanders, IRE, and Teaching Cycles. Twelve lessons were recorded on a cassette, transcribed, coded and analysed. Flanders category was the observational instrument. Test- retest method was used to establish the reliability of the instrument at 0.87 co-efficient. The result showed students’ responses in the classroom are not contingent on classroom technique used. The extent of students’ responses in the classroom is very minimal therefore teacher should go extra step to encourage voluntary verbal contribution by the students’ in every classroom. This makes the students more critical in weighing life challenges.

  1. IMF BY dependence of the extent of substorm westward electrojet

    Indian Academy of Sciences (India)

    T Arun; Ajay Dhar; K Emperumal; B M Pathan

    2005-04-01

    In this paper the duskward extension of the westward auroral electrojet is investigated for substorm intervals on the basis of magnetograms recorded at the Indian Antarctic station, Maitri. The database comprises three years from 1998-2000. Based on an initial study of the magnetograms, an arbitrary local time of 2030 MLT is fixed to define the early manifestation of the substorm westward electrojet. Using this criterion 12 substorms are identified and the possible causes examined. Many of these events are observed to be associated with a moderate to intense ring current.The hourly average of the GSM BY-component of the interplanetary magnetic field (IMF) for the hour preceding the substorm onset at Maitri is negative for most of the events. It is suggested that the azimuthal shift of the auroral electrojets in the southern hemisphere resulting from a negative BY-component of the IMF influences the extent of the substorm westward electrojet. This finding implies that the IMF may have a role in controlling the longitudinal extent of substorm occurrence.

  2. Using Dust as Probes to Determine Sheath Extent and Structure

    CERN Document Server

    Douglass, Angela; Qiao, Ke; Matthews, Lorin; Hyde, Truell

    2016-01-01

    Two in-situ experimental methods are presented in which dust particles are used to determine the extent of the sheath and gain information about the time-averaged electric force profile within a RF plasma sheath. These methods are advantageous because they are not only simple and quick to carry out, but they also can be performed using standard dusty plasma experimental equipment. In the first method, dust particles are tracked as they fall through the plasma toward the lower electrode. These trajectories are then used to determine the electric force on the particle as a function of height as well as the extent of the sheath. In the second method, dust particle levitation height is measured across a wide range of RF voltages. Similarities were observed between the two experiments, but in order to understand the underlying physics behind these observations, the same conditions were replicated using a self-consistent fluid model. Through comparison of the fluid model and experimental results, it is shown that t...

  3. The Extent of Students’ Initiation of Ideas in The Classroom

    Directory of Open Access Journals (Sweden)

    Oranu Philomena Chika

    2012-01-01

    Full Text Available This study sought to identify the extent of students’ initiation of ideas in the classroom using three classroom interaction techniques. All senior secondary schools in Port Harcourt Local Government Area, Rivers State, Nigeria constituted the population. One research question guided the study. One hypothesis was tested and analysed using chi square statistics. The population is made up of 10,983 students 496 teachers. The sample is made up of 1098 students and 12 teachers. SS1 and SS11 students in three public participated in the study. Six classroom were used; three in SS1 and three in SS11 respectively. Six teachers taught SS1 and six teachers taught SS11 using a technique (Flanders, IRE, and Teaching Cycles. Twelve lessons were recorded on a cassette, transcribed, coded and analysed. Flanders category was the observational instrument. Test- retest method was used to establish the reliability of the instrument at 0.87 co-efficient. The result showed students’ initiation ideas in the classroom is not contingent on classroom technique used. The extent of students’ initiation of ideas in the classroom is very minimal therefore teacher should go extra step to encourage voluntary verbal contribution by the students’ in every classroom. This makes them more critical and reflective in weighing life challenges.

  4. A comparison between remote sensing approaches to water extent monitoring

    Science.gov (United States)

    elmi, omid; javad tourian, mohammad; sneeuw, nico

    2013-04-01

    Monitoring the variation of water storage in a long period is a primary issue for understanding the impact of climate change and human activities on earth water resources. In order to obtain the change in water volume in a lake and reservoir, in addition to water level, water extent must be repeatedly determined in an appropriate time interval. Optical satellite imagery as a passive system is the main source of determination of coast line change as it is easy to interpret. Optical sensors acquire the reflected energy from the sunlight in various bands from visible to near infrared. Also, panchromatic mode provides more geometric details. Establishing a ratio between visible bands is the most common way of extract coastlines because with this ratio, water and land can be separated directly. Also, since the reflectance value of water is distinctly less than soil in infrared bands, applying a histogram threshold on this band is a effective way of coastline extraction. However, optical imagery is highly vulnerable to occurrence of dense clouds and fog. Moreover, the coastline is hard to detect where it is covered by dense vegetation. Synthetic aperture radar (SAR) as an active system provides an alternative source for monitoring the spatial change in coastlines. Two methods for monitoring the shoreline with SAR data have been published. First, the backscatter difference is calculated between two images acquired at different times. Second, the change in coastline is detected by computing the coherence of two SAR images acquired at different times. A SAR system can operate in all weather, so clouds and fog don't impact its efficiency. Also, it can penetrate into the plant canopy. However, in comparison with optical imagery, interpretation of SAR image in this case is relatively hard because of limitation in the number of band and polarization modes, also due to effects caused by speckle noises, slant-range imaging and shadows. The primary aim of this study is a

  5. The rate and extent of oral bioavailability versus the rate and extent of oral absorption: clarification and recommendation of terminology.

    Science.gov (United States)

    Chiou, W L

    2001-02-01

    In the literature, the meanings of the terms oral absorption and oral bioavailability of drugs vary greatly. Absorption has been considered to take place at the mucosal membrane of the gastrointestinal (GI) tract. It has also been defined as the process from the site of drug administration to the site of measurement. In the latter definition, the extent of oral absorption depends on the extent of first-pass elimination in the gut wall and liver even though a drug may be completely absorbed from the GI tract. Moreover, these two terms have also been used interchangeably. Inconsistency in the definition of these two terms has led to varying interpretations of these terms among students, researchers and laymen, and such an inconsistency seems undesirable. Apparently because of these inconsistencies, improper correlations between the Caco-2 permeability or intestinal permeability and the oral bioavailability of drugs subject to extensive first-pass effect may have occurred. It is suggested that absorption be defined as movement of drug across the outer mucosal membranes of the GI tract, while bioavailability be defined as availability of drug to the general circulation or site of pharmacological actions. Since transit times (this may range from about 1 min to several hours) across enterocytes, liver, lungs, and the peripheral venous sampling tissue are virtually unknown for all drugs, this factor alone would favor the use of "oral bioavailability rate" rather than "oral absorption rate" in all routine studies.

  6. Quantifying the extent of recrossing flux for quantumsystems

    Energy Technology Data Exchange (ETDEWEB)

    Small, Michael S.; Predescu, Cristian; Miller, William H.

    2005-04-19

    We present arguments demonstrating that the Miller, Schwartz, and Tromp (MST) correlation function is the only computationally reasonable choice with regard to minimizing the extent of recrossing flux. However, using accurate numerical results, we point out that the MST flux-flux correlation function almost always exhibits non-vanishing negative parts, even for the simplest physical systems. We argue that, in order to best handle the residual recrossing flux, one must not rely on the ''no recrossing'' assumption in the development of quantum transition state theories. To provide accurate numerical examples, we derive the analytical expressions for the flux-flux correlation and spectral functions for the symmetric Eckart and rectangular potential barriers.

  7. To what extent is language teaching methodology informed by theory?

    Institute of Scientific and Technical Information of China (English)

    朱殿勇; 崔丹

    2005-01-01

    With the globalization of the world, language teaching becomes more important than ever before, and many universities and classroom teachers are active to explore the most efficient and effective methodology to teach languages to achieve a desirable result. When they seek to improve the quality of language teaching, they ofter research teaching methodologies by referring to general theories about language and language learning. Theoretical bases and teachers' hands-out experience have informed methodologies of language teaching, and methods of language teaching have been improved with the developments about linguistics, psychology and education. But there is a question which extent the information that theory has made available can be used to explore language teaching methodology and of the relevance of theory to language teaching methodology.

  8. Lymphadenectomy in bladder cancer: What should be the extent?

    Directory of Open Access Journals (Sweden)

    K Muruganandham

    2010-01-01

    Full Text Available The extent of Lymh node dissection (LND during radical cystectomy is a subject of increasing importance with several studies suggesting that an extended LND may improve staging accuracy and outcome. Significant numbers of patients have lymph node metastasis above the boundaries of standard LND. Extended LND yields higher number of lymph nodes which may result in better staging. Various retrospective studies have reported better oncological outcomes with extended LND compared to limited LND. No difference in the mortality and the incidence of lymphocele formation has been found between ′standard′ and ′extended′ LND. Till we have a well-designed randomized controlled trial to address these issues for level 1 evidence, it is not justified to deny our patients the advantages of ′extended′ lymphadenectomy based on the current level of evidence.

  9. Learning Curve in a Western Training Center of the Circumferential En Bloc Esophageal Endoscopic Submucosal Dissection in an In Vivo Animal Model

    Directory of Open Access Journals (Sweden)

    Miguel A. Tanimoto

    2011-01-01

    Full Text Available Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE- ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to “the Principles of Humane Experimental Technique, Russel and Burch.” The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192±35 minutes (range 140–235 minutes. All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999–2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15–18 mm and 51±6.99 width (range 40–60 mm. Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows.

  10. Safety and effectiveness of a circumferential clip-based vascular closure device for hemostasis in off-label applications: Comparison with standard applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Chan; Kim, Chang Won [Dept. of Radiology, Pusan National University School of Medicine, Pusan National University Hospital, Busan (Korea, Republic of); Jeon, Ung Bae [Dept. of Radiology, Pusan National University School of Medicine, Yangsan Pusan National University Hospital, Yangsan (Korea, Republic of)

    2016-09-15

    We investigated the efficacy and safety of a circumferential nitinol clip based arterial closure device following arteriotomy, especially in off-label applications. Consecutive patients who underwent the procedure with arteriotomy from January 2011 to February 2014 were included in this study. We defined standard use as the use of StarClose for retrograde puncture of the common femoral artery (CFA) and off-label use as the use of StarClose for retrograde puncture of the superficial femoral artery (SFA), antegrade puncture of the CFA or SFA, puncture of the brachial artery or puncture of the vascular graft. The procedures performed included percutaneous transluminal angioplasty and thrombolysis. Technical success was defined as complete hemostasis achieved within 3 minute after the closure. Complications, and laboratory findings associated with coagulation function, were also investigated. There were 146 cases of standard applications and 111 cases of off-label applications. Technical success was achieved in all cases. The off-label group comprised the use of StarClose for retrograde puncture of the SFA (n = 19), antegrade puncture of the CFA or SFA (n = 74), brachial artery puncture (n = 5), larger sheath than 6 Fr (n = 7) and vascular graft puncture (n = 6). Minor complications were noted in both groups (standard group: 7.5%, off-label group: 2.7%). Off-label use of StarClose is safe and feasible.

  11. Learning Curve in a Western Training Center of the Circumferential En Bloc Esophageal Endoscopic Submucosal Dissection in an In Vivo Animal Model

    Science.gov (United States)

    Tanimoto, Miguel A.; Torres-Villalobos, Gonzalo; Fujita, Rikiya; Santillan-Doherty, Patricio; Albores-Saavedra, Jorge; Chable-Montero, Fredy; Martin-del-Campo, Luis A.; Vasquez, Lucia; Bravo-Reyna, Carlos; Villanueva, Octavio; Villalobos, Jose J.; Uribe, Misael; Valdovinos, Miguel A.

    2011-01-01

    Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE-) ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to “the Principles of Humane Experimental Technique, Russel and Burch.” The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192 ± 35 minutes (range 140–235 minutes). All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999–2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15–18 mm) and 51 ± 6.99 width (range 40–60 mm). Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows. PMID:21976950

  12. Numerical Study on the Effect of Single Shallow Circumferential Groove Casing Treatment on the Flow Field and the Stability of a Transonic Compressor

    Directory of Open Access Journals (Sweden)

    Mohsen Agha Seyed Mirzabozorg

    2017-01-01

    Full Text Available The present research investigates the effect of the location and the width of single shallow circumferential groove casing treatment on the flow field and the stability improvement of NASA Rotor 37 utilizing the help of computational fluid dynamics. At first, steady state simulation of Rotor37 was presented for smooth casing (without groove. Then, forty five various grooved casing were simulated and compared with the smooth casing. The results indicated that narrow grooves had slight effect on the adiabatic efficiency but as the width of the groove was increased, a decline in efficiency was observed. The investigation on the stall margin revealed that narrow grooves next to the leading edge could improve the stall margin by a reduction in the size of vortex breakdown zone. Medium-width grooves displayed an effective role in delaying the separation- produced by shock wave and boundary layer interaction- on the blade suction side near the casing. This type of grooves could improve the stall margin more than narrow grooves when located on the top of separation zone near the blade suction side. Wide grooves had negative effect on the stall margin and caused a significant drop in the efficiency and the total pressure ratio of the compressor.

  13. Status report on a NDT round robin on austenitic circumferential pipe welds; Statusbericht zu einem ZfP-Ringversuch an austenitischen Rohrleitungs-Rundschweissnaehten

    Energy Technology Data Exchange (ETDEWEB)

    Hesselmann, W. [PreussenElektra AG, Hannover (Germany); Maier, H.J.; Knoch, P.; Mletzko, U. [MPA, Stuttgart (Germany)

    1996-12-31

    Since fall 1993, a study is performed at MPA Stuttgart in cooperation with the Czech Association of large power plant operators, on non-destructive evaluation of austenitic circumferential pipe welds. The status report presents the project concept and the current progress. The project tasks until now cover NDE of 15 welds. Results are given of ultrasonic tests carried out by 9 institutions, X-ray film evaluations by 23 individuals, and further examinations analysed in comparison to the destructive verification tests (metallography). (orig./MM) [Deutsch] Seit Herbst 1993 wird an der MPA Stuttgart in Zusammenarbeit mit der Technischen Vereinigung der Grosskraftwerksbetreiber e.V. (VGB) eine Untersuchung ueber die zerstoerungsfreie Pruefung (ZfP) von austenitischen Rohrleitungs-Rundschweissnaehten durchgefuehrt. Dieser Statusbericht zeigt die Konzeption und den gegenwaertigen Stand des Programms. Das Vorhaben umfasst bis jetzt zerstoerungsfreie Pruefungen an 15 Naehten. Berichtet wird ueber Ultraschall-Pruefungen durch 9 Institutionen, ueber Roentgenfilm-Auswertungen durch 23 Personen sowie ueber weitere Untersuchungen im Vergleich mit der vollstaendigen zerstoerenden Verifizierung (Metallografie). (orig./MM)

  14. Predictors of circumferential resection margin involvement in surgically resected rectal cancer: A retrospective review of 23,464 patients in the US National Cancer Database

    Science.gov (United States)

    Al-Sukhni, Eisar; Attwood, Kristopher; Gabriel, Emmanuel; Nurkin, Steven J.

    2017-01-01

    Introduction The circumferential resection margin (CRM) is a key prognostic factor after rectal cancer resection. We sought to identify factors associated with CRM involvement (CRM+). Methods A retrospective review was performed of the National Cancer Database, 2004–2011. Patients with rectal cancer who underwent radical resection and had a recorded CRM were included. Multivariable analysis of the association between clinicopathologic characteristics and CRM was performed. Tumor patients, 13.3% were CRM+. Factors associated with CRM+ were diagnosis later in the study period, lack of insurance, advanced stage, higher grade, undergoing APR, and receiving radiation. Nearly half of CRM+ patients did not receive neoadjuvant therapy. CRM+ patients who did not receive neoadjuvant therapy were more likely to be female, older, with more comorbidities, smaller tumors, earlier clinical stage, advanced pathologic stage, and CEA-negative disease compared to those who received it. Conclusions Factors associated with CRM+ include features of advanced disease, undergoing APR, and lack of health insurance. Half of CRM+ patients did not receive neoadjuvant treatment. These represent cases where CRM status may be modifiable with appropriate pre-operative selection and multidisciplinary management. PMID:26906328

  15. Modeling of guided circumferential SH and Lamb-type waves in open waveguides with semi-analytical finite element and Perfectly Matched Layer method

    Science.gov (United States)

    Matuszyk, Paweł J.

    2017-01-01

    The circumferential guided waves (CGW) are of increasing interest for non-destructive inspecting pipes or other cylindrical structures. If such structures are buried underground, these modes can also deliver some valuable information about the surrounding medium or the quality of the contact between the pipe and the embedding medium. Toward this goal, the detailed knowledge of the dispersive characteristics of CGW is required; henceforth, the robust numerical method has to be established, which allows for the extensive study of the propagation of these modes under different loading conditions. Mathematically, this is the problem of the propagation of guided waves in an open waveguide. This problem differs significantly from the corresponding problem of a closed waveguide both in physical and numerical aspect. The paper presents a combination of semi-analytical finite element method with Perfectly Matched Layer technique for a class of coupled acoustics/elasticity problems with application to modeling of CGW. We discuss different aspects of our algorithm and validate the proposed approach against other established methods available in the literature. The presented numerical examples positively verify the robustness of the proposed method.

  16. Geologic interpretations of seismic data Route 128 (Northern Circumferential Highway) cut, and Hopkins Street grade separation stations 1-18 in Wakefield, Mass.

    Science.gov (United States)

    May, James E.; Lineham, Rev. Daniel

    1950-01-01

    The completion of a segment of the Northern Circumferential Highway, Route 126, in Wakefield, Mass., requires an underpass bridge at Hopkins Street, Station 5+50. The plan of the project shows approximately 1800 feet if approach cuts between stations 1 and 18. In October 1945 a preliminary seismic study was made of a segment of this cut between stations 6+50 and 13+30. Four profiles were made at this time and a report was submitted by Newton E. Chute and Rev. Daniel Linhan (file report of January 15). This work showed a relatively shallow (in general, 6 to 12 feet in depth) somewhat irregular bedrock surface between stations 6+50 and 13+50. That data indicated that much of this segment of the cut will be in bedrock. In order to obtain more complete data for the preparation of detailed estimates on the amount of bedrock to be excavated for this segment of the cut, and also to obtain sufficient data for the unexplored segment of the cut, 21 additional seismic traverses were made in September 1949. The present report contains only the results obtained from this later work. The work was performed as a part of a cooperative program of the Massachusetts Department of Public Works and the United States Geological Survey.

  17. Mathematical treatment of melting and solidification of phase change materials between circumferentially finned tubes. Analytische Behandlung des Schmelzens und Erstarrens von Latentwaermespeichermaterialien in Rippenrohrgeometrien

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, M.

    1987-01-01

    The following study deals with the theoretical investigation of heat transfer in a latent heat store. The object of the investigation is a heat exchanger element with a circumferentially finned tube, in which the space between the fins is filled with storage material. An analytical method, employing Green's function, was developed for this arrangement in order to solve the two dimensional (r,z-coordinates) transient heat conduction in inhomogenous materials with simultaneous phase change. When compared with other well-known analytical methods, the most important advantages are that the Fourier heat conduction equation and the boundary conditions at the phase front are simultaneously fulfilled by the final solution, as well as the fact that the initial temperature is independent of a given phase change temperature. A fundamental advantage can also be seen in the very small number of time steps for calculating the transient charging/discharging processes and hence shorter calculation times. Two special extreme cases were designed where the results agree well with literature data. In comparison with the numerically calculated melting and solidification behaviour only small variations were observed.

  18. Estimating Global Cropland Extent with Multi-year MODIS Data

    Directory of Open Access Journals (Sweden)

    Christopher O. Justice

    2010-07-01

    Full Text Available This study examines the suitability of 250 m MODIS (MODerate Resolution Imaging Spectroradiometer data for mapping global cropland extent. A set of 39 multi-year MODIS metrics incorporating four MODIS land bands, NDVI (Normalized Difference Vegetation Index and thermal data was employed to depict cropland phenology over the study period. Sub-pixel training datasets were used to generate a set of global classification tree models using a bagging methodology, resulting in a global per-pixel cropland probability layer. This product was subsequently thresholded to create a discrete cropland/non-cropland indicator map using data from the USDA-FAS (Foreign Agricultural Service Production, Supply and Distribution (PSD database describing per-country acreage of production field crops. Five global land cover products, four of which attempted to map croplands in the context of multiclass land cover classifications, were subsequently used to perform regional evaluations of the global MODIS cropland extent map. The global probability layer was further examined with reference to four principle global food crops: corn, soybeans, wheat and rice. Overall results indicate that the MODIS layer best depicts regions of intensive broadleaf crop production (corn and soybean, both in correspondence with existing maps and in associated high probability matching thresholds. Probability thresholds for wheat-growing regions were lower, while areas of rice production had the lowest associated confidence. Regions absent of agricultural intensification, such as Africa, are poorly characterized regardless of crop type. The results reflect the value of MODIS as a generic global cropland indicator for intensive agriculture production regions, but with little sensitivity in areas of low agricultural intensification. Variability in mapping accuracies between areas dominated by different crop types also points to the desirability of a crop-specific approach rather than attempting

  19. Extents of the aquifer and confining units of the Atlantic Coastal Plain of North and South Carolina aquifer system (pp1773_extents)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The data set pp1773_extents contains polygon datasets that represent the areal extents of each of the 16 hydrogeologic units of the of the Atlantic Coastal Plain of...

  20. Sensitivity of detachment extent to magnetic configuration and external parameters

    Science.gov (United States)

    Lipschultz, Bruce; Parra, Felix I.; Hutchinson, Ian H.

    2016-05-01

    Divertor detachment may be essential to reduce heat loads to magnetic fusion tokamak reactor divertor surfaces. Yet in experiments it is difficult to control the extent of the detached, low pressure, plasma region. At maximum extent the front edge of the detached region reaches the X-point and can lead to degradation of core plasma properties. We define the ‘detachment window’ in a given position control variable C (for example, the upstream plasma density) as the range in C within which the front location can be stably held at any position from the target to the X-point; increased detachment window corresponds to better control. We extend a 1D analytic model [1] to determine the detachment window for the following control variables: the upstream plasma density, the impurity concentration and the power entering the scrape-off layer (SOL). We find that variations in magnetic configuration can have strong effects; increasing the ratio of the total magnetic field at the X-point to that at the target, {{B}×}/{{B}t} , (total flux expansion, as in the super-x divertor configuration) strongly increases the detachment window for all control variables studied, thus strongly improving detachment front control and the capability of the divertor plasma to passively accommodate transients while still staying detached. Increasing flux tube length and thus volume in the divertor, through poloidal flux expansion (as in the snowflake or x-divertor configurations) or length of the divertor, also increases the detachment window, but less than the total flux expansion does. The sensitivity of the detachment front location, z h , to each control variable, C, defined as \\partial {{z}h}/\\partial C , depends on the magnetic configuration. The size of the radiating volume and the total divertor radiation increase \\propto {{≤ft({{B}×}/{{B}t}\\right)}2} and \\propto {{B}×}/{{B}t} , respectively, but not by increasing divertor poloidal flux expansion or field line length. We

  1. Estimating the extent of horizontal gene transfer in metagenomic sequences

    Directory of Open Access Journals (Sweden)

    Moya Andrés

    2008-03-01

    Full Text Available Abstract Background Although the extent of horizontal gene transfer (HGT in complete genomes has been widely studied, its influence in the evolution of natural communities of prokaryotes remains unknown. The availability of metagenomic sequences allows us to address the study of global patterns of prokaryotic evolution in samples from natural communities. However, the methods that have been commonly used for the study of HGT are not suitable for metagenomic samples. Therefore it is important to develop new methods or to adapt existing ones to be used with metagenomic sequences. Results We have created two different methods that are suitable for the study of HGT in metagenomic samples. The methods are based on phylogenetic and DNA compositional approaches, and have allowed us to assess the extent of possible HGT events in metagenomes for the first time. The methods are shown to be compatible and quite precise, although they probably underestimate the number of possible events. Our results show that the phylogenetic method detects HGT in between 0.8% and 1.5% of the sequences, while DNA compositional methods identify putative HGT in between 2% and 8% of the sequences. These ranges are very similar to these found in complete genomes by related approaches. Both methods act with a different sensitivity since they probably target HGT events of different ages: the compositional method mostly identifies recent transfers, while the phylogenetic is more suitable for the detections of older events. Nevertheless, the study of the number of HGT events in metagenomic sequences from different communities shows a consistent trend for both methods: the lower amount is found for the sequences of the Sargasso Sea metagenome, while the higher quantity is found in the whale fall metagenome from the bottom of the ocean. The significance of these observations is discussed. Conclusion The computational approaches that are used to find possible HGT events in complete

  2. 管间界面特性对周向超声导波传播特性的影响∗%Influence of the interfacial prop erties on guided circumferential wave propagation in the circular tub e structure

    Institute of Scientific and Technical Information of China (English)

    高广健; 邓明晰; 李明亮; 刘畅

    2015-01-01

    The mathematical expressions both of displacement and stress fields of circumferential wave propagation in circular tube structure with a weak interface are derived on condition that the interfacial properties between the two circular tubes are characterized by the interfacial spring model. Based on the said displacement and stress expressions derived, the dispersion equation of ultrasonic guided circumferential wave (UGCW) modes is formally presented by using the corresponding mechanical boundary conditions. According to the technique of modal expansion analysis for waveguide excitation, for a given excitation source used to generate circumferential wave in circular tube structure, the corresponding field of circumferential wave propagation can be decomposed into a series of UGCW modes. Using the reciprocity relations and mode orthogonality, the analytical expression of UGCW mode expansion coefficient is derived, which is closely related to the given excitation source for UGCW generation and the interfacial properties between the two tubes. The influences of change in the interfacial property on dispersion and acoustic field of the UGCW propagation are numerically analyzed. In the cases of perfect and sliding interfaces, for a given UGCW mode, the relative change rate of phase velocity is defined, and then its curve versus frequency is calculated, through which the specific frequency can be determined where the UGCW phase velocity appears to be most sensitive to the change in the interfacial property. For a given UGCW mode and driving frequency, it is numerically found that the displacement field on the outside surface of the circular tube structure changes sensitively and monotonically with change in interfacial property between the tubes. Clearly, through choosing the appropriate driving frequency and the mode of UGCW propagation, both the UGCW phase velocity and the displacement field on the outside surface of the circular tube structure will be monotonic and

  3. Analysis of circumferential and longitudinal left ventricular systolic function in patients with non-ischemic chronic heart failure and preserved ejection fraction (from the CARRY-IN-HFpEF study).

    Science.gov (United States)

    Cioffi, Giovanni; Senni, Michele; Tarantini, Luigi; Faggiano, Pompilio; Rossi, Andrea; Stefenelli, Carlo; Russo, Tiziano Edoardo; Alessandro, Selmi; Furlanello, Francesco; de Simone, Giovanni

    2012-02-01

    Heart failure with preserved left ventricular ejection fraction (HFpEF) is implicitly attributed to diastolic dysfunction, often recognized in elderly patients with hypertension, diabetes, and renal dysfunction. In these patients, left ventricular circumferential and longitudinal shortening is often impaired despite normal ejection fraction. The aim of this prospective study was to analyze circumferential and longitudinal shortening and their relations in patients with nonischemic HFpEF. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were measured in 60 patients (mean age 73 ± 13 years) with chronic nonischemic HFpEF in stable New York Heart Association functional class II or III and compared to the values in 120 healthy controls and 120 patients with hypertension without HFpEF. Sc-MS was classified as low if HFpEF, 27% of patients with hypertension, and 2% of controls; isolated low S' was detected in 11% of patients with HFpEF, 7% of patients with hypertension, and 5% of controls; and combined low sc-MS and low S' was detected in 26% of patients with HFpEF, 9% of patients with hypertension, and 5% of controls (HFpEF vs others, all p values HFpEF. The relation between sc-MS and S' was nonlinear (cubic). Changes in S' within normal values corresponded to negligible variations in sc-MS, whereas the progressive decrease below 8.5 cm/s was associated with substantial decrease in sc-MS. In conclusion, circumferential and/or longitudinal systolic dysfunction is present in most patients with HFpEF. Circumferential shortening normalized by wall stress identifies more patients with concealed left ventricular systolic dysfunction than longitudinal shortening.

  4. Application of structural reliability to multi-circumferential cracking in steam generator tubes; Application de la fiabilite des structures a la multifissuration circonferentielle des tubes de generateur de vapeur

    Energy Technology Data Exchange (ETDEWEB)

    Ardillon, E.; Riffard, T. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1997-12-31

    The COMPROMIS Code, developed by Electricite de France, is a probabilistic software tool concerned with assessment of probability of occurrence of a Steam Generator (SG) tube rupture caused by multi-circumferential cracking. It involves the calculation of low probabilities, for which Monte Carlo stratified sampling was selected. After a short description of the physical model, this paper presents the implementation of the numerical methods, some outputs of the code and sensitivity results of the rupture probability to input parameters. (author). 7 refs.

  5. Extent and modes of physics instruction in European dental schools.

    Science.gov (United States)

    Letić, Milorad; Popović, Gorjana

    2013-01-01

    Changes in dental education towards integration of sciences and convergence of curricula have affected instruction in physics. Earlier studies of undergraduate curricula make possible comparisons in physics instruction. For this study, the websites of 245 European dental schools were explored, and information about the curriculum was found on 213 sites. Physics instruction in the form of a separate course was found in 63 percent of these schools, with eighty-two hours and 5.9 European Credit Transfer and Accumulation System (ECTS) credits on average. Physics integrated with other subjects or into modules was found in 19 percent of these schools. Half of these schools had on average sixty-one hours and 6.9 ECTS credits devoted to physics. Eighteen percent of the schools had no noticeable obligatory physics instruction, but in half of them physics was found to be required or accepted on admission, included in other subjects, or appeared as an elective course. In 122 dental schools, the extent of physics instruction was found to be between forty and 120 contact hours. Physics instruction has been reduced by up to 14 percent in the last fourteen years in the group of eleven countries that were members of the European Union (EU) in 1997, but by approximately 30 percent in last five years in the group of ten Accession Countries to the EU.

  6. What controls the local time extent of flux transfer events?

    CERN Document Server

    Milan, S E; Carter, J A; Walach, M -T; Hubert, B

    2016-01-01

    Flux transfer events (FTEs) are the manifestation of bursty and/or patchy magnetic reconnection at the magnetopause. We compare two sequences of the ionospheric signatures of flux transfer events observed in global auroral imagery and coherent ionospheric radar measurements. Both sequences were observed during very similar seasonal and interplanetary magnetic field (IMF) conditions, though with differing solar wind speed. A key observation is that the signatures differed considerably in their local time extent. The two periods are 26 August 1998, when the IMF had components $\\mathit{B}_{\\mathit{z}}$ $\\approx$ -10 nT and $\\mathit{B}_{\\mathit{y}}$ $\\approx$ 9 nT and the solar wind speed was $\\mathit{V}_{\\mathit{x}}$ $\\approx$ 650 km $s^{-1}$, and 31 August 2005, IMF $\\mathit{B}_{\\mathit{z}}$ $\\approx$ -7 nT, $\\mathit{B}_{\\mathit{y}}$ $\\approx$ 17 nT, and $\\mathit{V}_{\\mathit{x}}$ $\\approx$ 380 km $s^{-1}$. In the first case, the reconnection rate was estimated to be near 160 kV, and the FTE signatures extended ...

  7. Food advertising on Australian television: the extent of children's exposure.

    Science.gov (United States)

    Neville, Leonie; Thomas, Margaret; Bauman, Adrian

    2005-06-01

    The objective of this study was to investigate the extent and nature of food advertising during Australian children's television (TV) viewing hours and programs, and to determine whether confectionery and fast food restaurant advertisements were more likely to be broadcast during children's programs than during adults' programs on Sydney television stations. One week (390 h) of Australian advertising data broadcast during children's TV viewing hours over 15 television stations were analysed to determine the proportion of food advertisements and, in turn, the proportion of those advertisements promoting foods high in fat and/or sugar. One week (346 h) of confectionery and fast food restaurant advertisements broadcast over three Sydney television stations were analysed to determine whether these types of advertisements were more likely to be advertised during children's programs than adults' programs. Half of all food advertisements promoted foods high in fat and/or sugar. 'Confectionery' and 'fast food restaurants' were the most advertised food categories during children's TV viewing hours. Confectionery advertisements were three times as likely, and fast food restaurant advertisements twice as likely, to be broadcast during children's programs than adults' programs. It can be concluded that foods most advertised during children's viewing hours are not those foods that contribute to a healthy diet for children. Confectionery and fast food restaurant advertising appears to target children. Australian children need protection from the targeted promotion of unhealthy foods on television, but currently little exists.

  8. To what extent do Gestalt grouping principles influence tactile perception?

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2011-07-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli. Although, to date, only a few studies have explicitly investigated the existence of Gestalt grouping principles in the tactile modality, we argue that many more studies have indirectly provided evidence relevant to this topic. Reviewing this body of research, we argue that similar principles to those reported previously in visual and auditory studies also govern the perceptual grouping of tactile stimuli. In particular, we highlight evidence showing that the principles of proximity, similarity, common fate, good continuation, and closure affect tactile perception in both unimodal and crossmodal settings. We also highlight that the grouping of tactile stimuli is often affected by visual and auditory information that happen to be presented simultaneously. Finally, we discuss the theoretical and applied benefits that might pertain to the further study of Gestalt principles operating in both unisensory and multisensory tactile perception.

  9. Quantifying the impact and extent of undocumented biomedical synonymy.

    Directory of Open Access Journals (Sweden)

    David R Blair

    2014-09-01

    Full Text Available Synonymous relationships among biomedical terms are extensively annotated within specialized terminologies, implying that synonymy is important for practical computational applications within this field. It remains unclear, however, whether text mining actually benefits from documented synonymy and whether existing biomedical thesauri provide adequate coverage of these linguistic relationships. In this study, we examine the impact and extent of undocumented synonymy within a very large compendium of biomedical thesauri. First, we demonstrate that missing synonymy has a significant negative impact on named entity normalization, an important problem within the field of biomedical text mining. To estimate the amount synonymy currently missing from thesauri, we develop a probabilistic model for the construction of synonym terminologies that is capable of handling a wide range of potential biases, and we evaluate its performance using the broader domain of near-synonymy among general English words. Our model predicts that over 90% of these relationships are currently undocumented, a result that we support experimentally through "crowd-sourcing." Finally, we apply our model to biomedical terminologies and predict that they are missing the vast majority (>90% of the synonymous relationships they intend to document. Overall, our results expose the dramatic incompleteness of current biomedical thesauri and suggest the need for "next-generation," high-coverage lexical terminologies.

  10. Measuring marine oil spill extent by Markov Random Fields

    Science.gov (United States)

    Moctezuma, Miguel; Parmiggiani, Flavio; Lopez Lopez, Ludwin

    2014-10-01

    The Deepwater Horizon oil spill of the Gulf of Mexico in the spring of 2010 was the largest accidental marine oil spill in the history of the petroleum industry. An immediate request, after the accident, was to detect the oil slick and to measure its extent: SAR images were the obvious tool to be employed for the task. This paper presents a processing scheme based on Markov Random Fields (MRF) theory. MRF theory describes the global information by probability terms involving local neighborhood representations of the SAR backscatter data. The random degradation introduced by speckle noise is dealt with a pre-processing stage which applies a nonlinear diffusion filter. Spatial context attributes are structured by the Bayes equation derived from a Maximum-A-Posteriori (MAP) estimation. The probability terms define an objective function of a MRF model whose goal is to detect contours and fine structures. The markovian segmentation problem is solved with a numerical optimization method. The scheme was applied to an Envisat/ASAR image over the Gulf of Mexico of May 9, 2010, when the oil spill was already fully developed. The final result was obtained with 51 recursion cycles, where, at each step, the segmentation consists of a 3-class label field (open sea and two oil slick thicknesses). Both the MRF model and the parameters of the stochastic optimization procedure will be provided, together with the area measurement of the two kinds of oil slick.

  11. The lateral extent of volcanic interactions during unrest and eruption

    Science.gov (United States)

    Biggs, Juliet; Robertson, Elspeth; Cashman, Katharine

    2016-04-01

    Volcanic eruptions often occur simultaneously or tap multiple magma reservoirs. Such lateral interactions between magmatic systems are attributed to stress changes or hydraulic connections but the precise conditions under which coupled eruptions occur have yet to be quantified. Here we use interferometric synthetic aperture radar satellite data to analyse the surface deformation generated by volcanic unrest in the Kenyan Rift. We identify several magma sources located at depths of 2-5 km importantly, sources that are spaced less than about 10 km apart interact, whereas those spaced more than about 25 km apart do not. However, volcanoes up to 25 km apart have interacted in the geologic past. Thus, volcanic coupling is not simply controlled by the distance between the magma reservoirs. We then consider different tectonic settings globally, including intraplate volcanoes such as Hawaii and Yellowstone, arc volcanism in Alaska and Chile, and other rift settings, such as New Zealand, Iceland and Afar. We find that the most closely spaced magmatic interactions are controlled by the extent of a shallow crystal mush layer, stress changes can couple large eruptions over distances of about 20-40 km, and only large dyke intrusions or subduction earthquakes could generate coupled eruptions over distances of about 50-100 km.

  12. Distracted walking: Examining the extent to pedestrian safety problems

    Directory of Open Access Journals (Sweden)

    Judith Mwakalonge

    2015-10-01

    Full Text Available Pedestrians, much like drivers, have always been engaged in multi-tasking like using hand-held devices, listening to music, snacking, or reading while walking. The effects are similar to those experienced by distracted drivers. However, distracted walking has not received similar policies and effective interventions as distracted driving to improve pedestrian safety. This study reviewed the state-of-practice on policies, campaigns, available data, identified research needs, and opportunities pertaining to distracted walking. A comprehensive review of literature revealed that some of the agencies/organizations disseminate useful information about certain distracting activities that pedestrians should avoid while walking to improve their safety. Various walking safety rules/tips have been given, such as not wearing headphones or talking on a cell phone while crossing a street, keeping the volume down, hanging up the phone while walking, being aware of traffic, and avoiding distractions like walking with texting. The majority of the past observational-based and experimental-based studies reviewed in this study on distracted walking is in agreement that there is a positive correlation between distraction and unsafe walking behavior. However, limitations of the existing crash data suggest that distracted walking may not be a severe threat to the public health. Current pedestrian crash data provide insufficient information for researchers to examine the extent to which distracted walking causes and/or contributes to actual pedestrian safety problems.

  13. Chemophobia in the College Classroom: Extent, Sources, and Student Characteristics

    Science.gov (United States)

    Eddy, Roberta M.

    2000-04-01

    The purpose of this research was to provide an understanding of chemophobia (chemistry anxiety) at the college level by determining (i) the extent of chemophobia in the college classroom; (ii) the factors that contribute to college students' anxiety about learning chemistry and handling chemicals; and (iii) the characteristics of college students who have anxiety about learning chemistry and handling chemicals. A questionnaire containing the Derived Chemistry Anxiety Rating Scale (mean = 81.47, SD = 21.31, a = 0.94), the Revised Mathematics Anxiety Rating Scale (mean = 56.68, SD = 20.55, a = 0.98), and the Trait-Anxiety Scale (mean = 39, SD = 10, a = 0.90) was administered to 480 college students (435 nonmajors and 45 chemistry majors) taking an introductory chemistry course. Eight interviews were conducted. Quantitative data were analyzed by SPSS (p ?.05). Chemophobia was found to exist at an average level between a little bit and moderate. Highest anxiety was associated with chemistry evaluation; lowest anxiety with learning chemistry. Sources that contributed most to chemistry anxiety were, for learning, chemical equations; for evaluation, taking the final exam; and for handling chemicals, getting chemicals on hands. Women had significantly higher anxiety than men. Students with low chemistry experience had significantly higher anxiety than students with high chemistry experience. There were no significant main effects for type of major or math experience.

  14. Electroanatomical systems to guided circumferential pulmonary veins ablation for atrial fibrillation: initial experience from comparison between the Ensite/NavX and CARTO system

    Institute of Scientific and Technical Information of China (English)

    LIU Xu; WANG Xin-hua; GU Jia-ning; ZHOU Li; QIU Jian-hua

    2005-01-01

    Background The circumferential pulmonary vein ablation (CPVA) has been proved effective for atrial fibrillation (AF) treatment and is becoming more widely accepted and practiced. This study aims to evaluate the characteristics of the CARTO and the Ensite/NavX system and draw a comparison between them on the aspects of procedural parameters and clinical effectiveness.Methods Seventy-five cases with paroxysmal or chronic symptomatic AF were randomly assigned to CPVA procedure guided by the Ensite/NavX system (group Ⅰ, n=40) and by the CARTO system (group Ⅱ, n=35). After successful transseptal procedure, the geometry of left atrium was created under the guidance of the two systems. Radiofrequency energy was applied to circumferentially ablate tissues out of pulmonary veins' (PVs') ostia. In cases with chronic AF, linear ablation was applied to modify the substrate of left atrium (LA). The endpoint of the procedure was complete PVs isolation. Results Seventy-five cases underwent the procedure successfully. The total procedure and fluoroscopic durations in group Ⅱ were significantly shorter than in group Ⅰ [(150±23) min and (18±17) min versus (170±34) min and (25±16) min, P=0.03 and 0.04, respectively]. There was no significant difference in the fluoroscopic and procedure durations for geometry creation between group Ⅰ and group Ⅱ [(8±4) min and (16±11) min versus (5±4) min and (14±8) min, respectively]. The fluoroscopic durations for CPVA were (15±5) min in group Ⅰ versus (10±6) min in group Ⅱ (P=0.05), and the CPVA procedural durations were significantly shorter in group Ⅱ than in group Ⅰ [(18±11) min versus (25±10) min, P=0.04]. AF was terminated by radio frequency delivery in 14 cases (35%) in group Ⅰ versus 5 cases (14%) in group Ⅱ (P=0.035). After CPVA complete PV isolation was attained in 26 cases (65%) in group Ⅰ versus 11 cases (31%) in group Ⅱ (P=0.004). During a mean follow-up of 7 months, 32 (80%) cases in group

  15. A randomized prospective comparison of CartoMerge and CartoXP to guide circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; MA Jian; ZHANG Shu; ZHANG Jing-ying; WEI Yi-dong; CHEN Yan-qing; YU Xue-jing; XU Ya-wei

    2008-01-01

    Background CartoXP and CartoMerge have been used to treat atrial fibrillation(AF)for several years.Our randomized prospective study compared clinical outcomes of these two versions of three dimensional electroanatomic mapping system in guiding catheter ablation for paroxysmal atrial fibrillation (PAF).Methods Eighty-one patients with symptomatic,drug refractory PAF were randomly assigned to CartoMerge group (n=42,mean age(54.5±13.1)years,history of AF=3.2 years)or CartoXP group(n=39,mean age(59.8±15.6)years,history of AF=2.9 years).All patients underwent 64-slice computed tomography(MSCT)1 to 3 days prior to ablation procedure.Using CartoMergeTM Image Integration Module,3D anatomical images of the left atrium(LA)and pulmonary veins(PVs)derived from MSCT of CartoMerge group were established and merged with the electroanatomical map.The integrated images were used to guide the procedure of circumferential pulmonary vein isolation (CPVI).In the other group,CPVI was guided just by CartoXP.The endpoint of CPVI in both groups was abolition or dissociation of pulmonary vein potentials(PVPs).Results Mapping points to establish the electroanatomical model of the LA/PVs were 48.7±13.4 in CartoMerge group and 62.5±15.7 in CartoXP group(P<0.001).Mean distance between mapping points and the MSCT surfaces in CartoMerge group was(1.59±0.33)mm.Accomplishment of abolition or dissociation of PVPs was achieved 95.2% in CartoMerge group and 92.3% in CartoXP group.Durations of procedure and exposure to X-ray were(156±25)minutes,(179±21)minutes(P<0.001) and(19.6±7.5)minutes,(28.5±12.8)minutes(P<0.001),respectively.After a follow-up with duration of(11.9±3.1)months vs (12.4±3.6)months post the first ablation procedure,patients free of AF were 33(78.6%)in CartoMerge group and 29(74.4%) in CartoXP group(P>0.50).No patient suffered pulmonary vein stenosis,alrioesophageal fistula,stroke or death.Conclusion Compared to CartoXP,CartoMerge shortened the catheter ablation

  16. Initial experience with circumferential pulmonary vein isolation guided by Overlay Ref and CartoMerge in the treatment of paroxysmal atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; ZHAO Dong-dong; ZHANG Jing-ying; CHEN Yan-qing; XU Ya-wei

    2010-01-01

    Background CartoMerge has been widely used in guiding circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal atrial fibrillation (PAF).However, the procedure of landmarks selection varies among operators according to their experience.Techniques have to be established to standardize this procedure.We propose that Overlay Ref could facilitate this procedure.This paper aimed to report our initial experience with CPVI guided by Overlay Ref and CartoMerge for the treatment of PAF.Methods Fifty-nine patients with PAF were enrolled in this study.Using Overlay Ref technique, a reference image (inverted) was faded into the live fluoroscopic image.Landmarks of CartoMerge were selected from anatomic points of the top of superior pulmonary veins (PVs) and the bottom of inferior PVs guided by Overlay Ref image.Overlay Ref images were also used to guide the ablation procedure combining with CartoMerge.Results All patients were successfully mapped by CartoMerge guided by Overlay Ref.The distance between the mapping points and the CT surfaces was (1.42±0.67) mm for the patients as a whole.This led to a successful rate of 96%for isolation of pulmonary veins.Duration of ablation procedure was (92±17) minutes.And the total duration of procedure was (139±32) minutes.CartoMerge could also be performed just with 3 paries to 4 paries selected landmarks guided by Overlay Ref without a full anatomic model constructed by Carto.Then, the total duration of procedure could be shortened to (115±38) minutes.Conclusions Overlay Ref technique can facilitate the catheter ablation of PAF and can help to standardize the procedure of landmarks selection.

  17. Distance between the rectal wall and mesorectal fascia measured by MRI: Effect of rectal distension and implications for preoperative prediction of a tumour-free circumferential resection margin

    Energy Technology Data Exchange (ETDEWEB)

    Slater, A. [Department of Specialist Radiology, University College Hospital, London (United Kingdom); Halligan, S. [Department of Specialist Radiology, University College Hospital, London (United Kingdom); Taylor, S.A. [Department of Specialist Radiology, University College Hospital, London (United Kingdom); Marshall, M. [Intestinal Imaging Centre, St Mark' s Hospital, Northwick Park, London (United Kingdom)

    2006-01-15

    Aim: To determine the effect of rectal distension, used by some workers to facilitate staging, on mesorectal tissues. Subjects and methods: Ninety-seven consecutive rectal cancer staging MRI examinations were identified of which 76 were analysable: 48 studies were performed using rectal insufflation of 100 ml room air and 28 were performed without distension. Median age was 69 and 72 years, respectively. In each patient a single experienced observer measured the distance from the outer rectal wall to the inner margin of the mesorectal fascia at four locations (12, 3, 6 and 9 o'clock), excluding sites of tumour involvement, from the T1-weighted axial image at the level of the sacro-coccygeal junction. The two groups of measurements were compared using Mann-Whitney test statistic, and frequencies then categorized into <5 mm or {>=}5 mm, and compared using Fisher's exact test. Results: The median distance between the rectal wall and mesorectal fascia in the distended group was approximately half that found in the non-distended group, and significantly lower at the 3, 6 and 9 o'clock positions (p<0.001). 68/167 (41%) of measurements were 5 mm or less, compared with 19/104 (18%) in the non-distended group (p<0.001). Conclusion: Rectal distension before MRI significantly reduces the distance between the rectal wall and mesorectal fascia. Although this is advocated to facilitate visualization of the primary tumour, it potentially affects the accuracy with which a clear circumferential resection margin can be predicted.

  18. N-acetylcysteine for the prevention of stricture after circumferential endoscopic submucosal dissection of the esophagus: a randomized trial in a porcine model

    Directory of Open Access Journals (Sweden)

    Barret Maximilien

    2012-05-01

    Full Text Available Abstract Background Circumferential endoscopic submucosal dissection (CESD of the esophagus would allow for both the eradication of Barrett’s esophagus and its related complications, such as advanced neoplasia. However, such procedures generally induce inflammatory repair resulting in a fibrotic stricture. N-acetylcysteine (NAC is an antioxidant that has shown some efficacy against pulmonary and hepatic fibrosis. The aim of our study was to evaluate the benefit of NAC in the prevention of esophageal cicatricial stricture after CESD in a swine model. Animals and methods Two groups of six pigs each were subjected to general anesthesia and CESD: after randomization, a first group received an oral NAC treatment regimen of 100 mg/kg/day, initiated one week before the procedure, whereas a second group was followed without any prophylactic treatment. Follow-up endoscopies took place seven, fourteen, twenty-one, and twenty-eight days after CESD. Necropsy, histological assessment of esophageal inflammation, and fibrosis were performed on day 28. Results The median esophageal lumen diameter on day 21 (main judgment criterion was 4 mm (range 2 to 5 in group 1 and 3 mm (range 1 to 7 in group 2 (P = 0.95. No significant difference was observed between the two groups regarding clinical evaluation (time before onset of clinically significant esophageal obstruction, number of dilations, esophageal inflammation and fibrosis, or oxidative stress damage on immunohistochemistry. Conclusions Despite its antioxidant effect, systemic administration of NAC did not show significant benefit on esophageal fibrosis in our animal model of esophageal wound healing within the experimental conditions of this study. Since the administered doses were relatively high, it seems unlikely that NAC might be a valuable option for the prevention of post-endoscopic esophageal stricture.

  19. 周向多爆炸成型弹丸战斗部仿真%Simulation Study of Circumferential MEFP Warhead

    Institute of Scientific and Technical Information of China (English)

    张利; 彭雪琴

    2014-01-01

    为了提高多爆炸成形弹丸(MEFP)对武装直升机、巡航导弹及空地制导武器等目标的毁伤能力,通过在炸药周向布置多个药型罩、轴向布置多层结构的办法,设计了一种新型多枚爆炸成形弹丸战斗部,分析了弹丸成型过程中的力学特性并利用动力学仿真软件模拟了成形过程。毁伤计算结果表明:该型战斗部所形成的单个EFP在穿透10 mm 装甲后仍具有较高的剩余动能,对轻型装甲目标具有较高的毁伤效能,研究结果可为小口径MEFP战斗部设计提供参考。%To strength the multiple explosively formed projectiles’(MEFP)damage effect on such targets like armed helicopters,cruise missiles and ground guided weapons,liners this paper designed were cir-cumferential layered with multi-layers along the axial.After the analysis on the EFP’s mechanical proper-ties during the forming process,the dynamic simulation software was adopted to reappear this forming process.De Marre formula calculation results show:the single EFP’s residual kinetic energy was signifi-cant even after it penetrated 10mm armor plate.The result of this paper indicates that MEFP warhead has impressive prospect to damage the abovementioned targets,and it will provide valuable reference for the Small-Caliber of the EFP’s warhead.

  20. Rate and extent of aqueous perchlorate removal by iron surfaces.

    Science.gov (United States)

    Moore, Angela M; De Leon, Corinne H; Young, Thomas M

    2003-07-15

    The rate and extent of perchlorate reduction on several types of iron metal was studied in batch and column reactors. Mass balances performed on the batch experiments indicate that perchlorate is initially sorbed to the iron surface, followed by a reduction to chloride. Perchlorate removal was proportional to the iron dosage in the batch reactors, with up to 66% removal in 336 h in the highest dosage system (1.25 g mL(-1)). Surface-normalized reaction rates among three commercial sources of iron filings were similar for acid-washed samples. The most significant perchlorate removal occurred in solutions with slightly acidic or near-neutral initial pH values. Surface mediation of the reaction is supported by the absence of reduction in batch experiments with soluble Fe2+ and also by the similarity in specific reaction rate constants (kSA) determined for three different iron types. Elevated soluble chloride concentrations significantly inhibited perchlorate reduction, and lower removal rates were observed for iron samples with higher amounts of background chloride contamination. Perchlorate reduction was not observed on electrolytic sources of iron or on a mixed-phase oxide (Fe3O4), suggesting that the reactive iron phase is neither pure zerovalent iron nor the mixed oxide alone. A mixed valence iron hydr(oxide) coating or a sorbed Fe2+ surface complex represent the most likely sites for the reaction. The observed reaction rates are too slow for immediate use in remediation system design, but the findings may provide a basis for future development of cost-effective abiotic perchlorate removal techniques.

  1. Migratory decisions in birds: Extent of genetic versus environmental control

    Science.gov (United States)

    Ogonowski, M.S.; Conway, C.J.

    2009-01-01

    Migration is one of the most spectacular of animal behaviors and is prevalent across a broad array of taxa. In birds, we know much about the physiological basis of how birds migrate, but less about the relative contribution of genetic versus environmental factors in controlling migratory tendency. To evaluate the extent to which migratory decisions are genetically determined, we examined whether individual western burrowing owls (Athene cunicularia hypugaea) change their migratory tendency from one year to the next at two sites in southern Arizona. We also evaluated the heritability of migratory decisions by using logistic regression to examine the association between the migratory tendency of burrowing owl parents and their offspring. The probability of migrating decreased with age in both sexes and adult males were less migratory than females. Individual owls sometimes changed their migratory tendency from one year to the next, but changes were one-directional: adults that were residents during winter 2004-2005 remained residents the following winter, but 47% of adults that were migrants in winter 2004-2005 became residents the following winter. We found no evidence for an association between the migratory tendency of hatch-year owls and their male or female parents. Migratory tendency of hatch-year owls did not differ between years, study sites or sexes or vary by hatching date. Experimental provision of supplemental food did not affect these relationships. All of our results suggest that heritability of migratory tendency in burrowing owls is low, and that intraspecific variation in migratory tendency is likely due to: (1) environmental factors, or (2) a combination of environmental factors and non-additive genetic variation. The fact that an individual's migratory tendency can change across years implies that widespread anthropogenic changes (i.e., climate change or changes in land use) could potentially cause widespread changes in the migratory tendency of

  2. Experimental investigation of extending stall-free mechanism of three-dimensional flow in circumferential skewed axial fans%周向弯曲叶片内部三维流动扩稳机理的实验研究

    Institute of Scientific and Technical Information of China (English)

    金光远; 欧阳华; 杜朝辉

    2013-01-01

    In this paper,the three-dimensional flow field at downstream of lower pressure axial fans with circumferential forward-skewed,backward-skewed blades are successfully measured using a hot-wire CTA system at off-design conditions.An X hot-wire probe is used to obtain three-dimensional velocity.Based on measurement results,the evolution of three-dimensional flow in these fans according to flow rate,and the effect of circumferential skewed blades on transporting of boundary layer at off-design conditions are discussed.The measurement results show that as flow rate decreases,three-dimensional flow structure is changed by circumferential skewed blades; the obvious suppression of passage flow is found near shroud and hub region,which is benefitial to improve stable operation range of circumferential skewed rotors; as centrifugal force increases,blade radial force Fr of circumferential forward-skewed blade has a positive effect on pressure gratitude,and seems to be efficient to control the velocity and direction of boundary layer movement.%对带有周向前弯和周向后弯叶片的低压轴流风机,采用双丝热线技术实验研究了周向弯曲叶片出口三维流动随流量降低变化规律.基于测量结果,详细阐述了周向弯曲叶片流道内三维流动结构的演化发展过程,分析非设计工况下叶片弯掠对流动的影响规律,结合径向平衡方程讨论了周向弯曲叶片对变工况边界层迁移的控制.结果表明:小流量工况下,周向弯曲叶片显著改变了流道内流动结构,且明显改善上下端壁区域的流通性,对于扩大稳定工作范围有着积极的作用;由于旋转离心力的增大,Fr对于径向压力梯度影响也发生变化,从而改变边界层的迁移方向和速度.

  3. Extent of Cropland and Related Soil Erosion Risk in Rwanda

    Directory of Open Access Journals (Sweden)

    Fidele Karamage

    2016-06-01

    Full Text Available Land conversion to cropland is one of the major causes of severe soil erosion in Africa. This study assesses the current cropland extent and the related soil erosion risk in Rwanda, a country that experienced the most rapid population growth and cropland expansion in Africa over the last decade. The land cover land use (LCLU map of Rwanda in 2015 was developed using Landsat-8 imagery. Based on the obtained LCLU map and the spatial datasets of precipitation, soil properties and elevation, the soil erosion rate of Rwanda was assessed at 30-m spatial resolution, using the Revised Universal Soil Loss Equation (RUSLE model. According to the results, the mean soil erosion rate was 250 t·ha−1·a−1 over the entire country, with a total soil loss rate of approximately 595 million tons per year. The mean soil erosion rate over cropland, which occupied 56% of the national land area, was estimated at 421 t·ha−1·a−1 and was responsible for about 95% of the national soil loss. About 24% of the croplands in Rwanda had a soil erosion rate larger than 300 t·ha−1·a−1, indicating their unsuitability for cultivation. With a mean soil erosion rate of 1642 t·ha−1·a−1, these unsuitable croplands were responsible for 90% of the national soil loss. Most of the unsuitable croplands are distributed in the Congo Nile Ridge, Volcanic Range mountain areas in the west and the Buberuka highlands in the north, regions characterized by steep slopes (>30% and strong rainfall. Soil conservation practices, such as the terracing cultivation method, are paramount to preserve the soil. According to our assessment, terracing alone could reduce the mean cropland soil erosion rate and the national soil loss by 79% and 75%, respectively. After terracing, only a small proportion of 7.6% of the current croplands would still be exposed to extreme soil erosion with a rate >300 t·ha−1·a−1. These irremediable cropland areas should be returned to mountain forest to

  4. Evaluation of nature and extent of injuries during Dahihandi festival

    Directory of Open Access Journals (Sweden)

    P Nemade

    2012-01-01

    Full Text Available Background: Injuries related to the Hindu festival of Dahihandi where a human pyramid is formed and a pot of money kept at a height is broken, celebrated in the state of Maharashtra, have seen a significant rise in the past few years. The human pyramid formed is multi-layered and carries with it a high risk of injury including mortality. Aims: To evaluate the nature, extent and influencing factors of injuries related to Dahihandi festival. Settings and Design: We present a retrospective analysis of patients who presented in a tertiary care center with injuries during the Dahihandi festival in the year 2010. Materials and Methods: 124 patients′ records were evaluated for timing of injury, height of the Dahihandi pyramid, position of the patient in the multi-layered pyramid, mode of pyramid collapse and mechanism of an injury. A binary regression logistic analysis for risk factors was done at 5% significance level. Statistical Analysis: Univariate and multi-variate binary logistic regression of the risk factors for occurrence of a major or minor injury was done using Minitab™ version 16.0 at 5% significance. Results: Out of 139 patients presented to the center, 15 were not involved directly in the formation of pyramid, rest 124 were included in the analysis. A majority of the patients were above 15 years of age [110 (83.6%]. 46 (37.1% patients suffered major injuries. There were 39 fractures, 3 cases of chest wall trauma with 10 cases of head injuries and 1 death. More than half of the patients [78 (56.1%] were injured after 1800 hours. 73 (58.9% injured participants were part of the pyramid constructed to reach the Dahihandi placed at 30 feet or more above the ground. 72 (51.8% participants were part of the middle layers of the pyramid. Fall of a participant from upstream layers on the body was the main mechanism of injury, and majority [101 (81.5%] of the patients suffered injury during descent phase of the pyramid. Conclusions: There is a

  5. A Fully Automated Classification for Mapping the Annual Cropland Extent

    Science.gov (United States)

    Waldner, F.; Defourny, P.

    2015-12-01

    Mapping the global cropland extent is of paramount importance for food security. Indeed, accurate and reliable information on cropland and the location of major crop types is required to make future policy, investment, and logistical decisions, as well as production monitoring. Timely cropland information directly feed early warning systems such as GIEWS and, FEWS NET. In Africa, and particularly in the arid and semi-arid region, food security is center of debate (at least 10% of the population remains undernourished) and accurate cropland estimation is a challenge. Space borne Earth Observation provides opportunities for global cropland monitoring in a spatially explicit, economic, efficient, and objective fashion. In the both agriculture monitoring and climate modelling, cropland maps serve as mask to isolate agricultural land for (i) time-series analysis for crop condition monitoring and (ii) to investigate how the cropland is respond to climatic evolution. A large diversity of mapping strategies ranging from the local to the global scale and associated with various degrees of accuracy can be found in the literature. At the global scale, despite efforts, cropland is generally one of classes with the poorest accuracy which make difficult the use for agricultural. This research aims at improving the cropland delineation from the local scale to the regional and global scales as well as allowing near real time updates. To that aim, five temporal features were designed to target the key- characteristics of crop spectral-temporal behavior. To ensure a high degree of automation, training data is extracted from available baseline land cover maps. The method delivers cropland maps with a high accuracy over contrasted agro-systems in Ukraine, Argentina, China and Belgium. The accuracy reached are comparable to those obtained with classifiers trained with in-situ data. Besides, it was found that the cropland class is associated with a low uncertainty. The temporal features

  6. Circumferential ′ Woolly Hair Naevus

    Directory of Open Access Journals (Sweden)

    Thadeus J

    1998-01-01

    Full Text Available Woolly hair naevus presents as a circumscribed area of tightly coiled hair since birth, in an individual of non-negroid origin. We report a 10 year old boy of Indian origin who presented with woolly hair in the periphery of the scalp and normal straight hair in the center-mimicking a straight hair naevus.

  7. The international extent and elasticity of lifestyle television

    Directory of Open Access Journals (Sweden)

    Pia Majbritt Jensen

    2008-09-01

    Full Text Available Lifestyle is a TV genre that exists predominantly on the screens of Northern Europe and Anglophone countries such as the UK, the USA and Australia. Hence, lifestyle formats are not traded globally but rather trans-nationally within a distinct geo-linguistic region. Nonetheless, lifestyle programming is still produced very differently within this region according to the media systemic conditions of the specific national TV markets and the specific broadcasters and channels in question. As such, the lifestyle genre is indeed tremendously flexible and elastic and can be used in a diverse number of ways, catering for local broadcasters’ image and target groups, local markets’ competitive conditions, media regulations, and history. This article investigates the international extent of the genre and looks into possible explanations for its Anglophone and Northern European bias. Subsequently, the great elasticity of the genre is examined by way of a thorough analysis of the Australian and Danish versions of the program format The Block, which will demonstrate precisely how the genre can be adapted radically differently to suit two diverse broadcasters and their diverse conditions. Livsstilsgenrens internationale udbredelse og elasticitet Artiklen tager et produktionsperspektiv på livsstils-tv, der er en relativt ny underholdningsgenre. Den har sine historiske rødder i de didaktiske faktagenrer, men dens moderne, mere underholdende[,] version blev født på britisk tv’s primetime i 1990’erne, hvorfra den spredtes internationalt, hovedsageligt til andre angelsaksiske lande samt Danmark og resten af Nordeuropa. Et andet karakteristika ved genren er, at livsstilsprogrammerne i stigende omfang handles på det internationale tv-marked som programformater, der efterfølgende versioneres lokalt på en sådan måde, at de passes ind efter markedsforhold uden for deres originale hjemmemarked. Livsstilsformaterne danner således en ny og anderledes og

  8. Stand Factors and Risk Analysis of Harm Extent of Gypsy Moths

    Institute of Scientific and Technical Information of China (English)

    Shi Juan; Yan Guozeng; Guan Ling; Li Zhenyu; Feng Jihua

    2006-01-01

    Twelve stand factors affecting the harm extent of Gypsy moths (Lymantria dispar) were studied.Through stepwise regression analyses,three key factors were selected,such as crown density,soil infertility extent,and forestland area.The results showed that there exists a positive correlation between soil infertility extent and the harm extent of Gypsy moths and a significant negative correlation between the other two key factors and the harm extent of this insect.Using the three key factors,a multivariate linear regression model was established by which the authors made a risk analysis of the harm extent of Gypsy moths.

  9. An essay on the extent and significance of the Greek athletic culture in the classical period

    DEFF Research Database (Denmark)

    Nielsen, Thomas Heine

    2014-01-01

    This article discusses the extent of the Greek athletic culture in the classical period. It is demonstrated that the athletic culture had a surprising extent, and the article goes on the discuss the historical significance of this fact.......This article discusses the extent of the Greek athletic culture in the classical period. It is demonstrated that the athletic culture had a surprising extent, and the article goes on the discuss the historical significance of this fact....

  10. Clinical study of microsplint and circumferential wiring in the treatment of mandibular body fracture in children%微型夹板配合环颌结扎治疗儿童下颌体部骨折的研究

    Institute of Scientific and Technical Information of China (English)

    姜刚勇

    2015-01-01

    目的:探讨微型夹板配合环颌结扎固定在儿童下颌骨体部骨折治疗中的应用。方法:选择2009~2012年儿童下颌体部骨折23例,采用微型夹板配合环颌结扎固定,观察其疗效。结果:微型夹板配合环颌结扎固定方法对儿童下颌骨骨折进行治疗具有不损伤恒牙胚,骨折复位良好、固定稳固、不影响进食,便于口腔清洁的特点。结论:微型夹板配合环颌结扎固定是治疗儿童下颌骨体部骨折的有效方法。%Objective:To evaluate the application of microsplint and circumferential wiring in the treatment of mandibular body frac-ture in children.Methods:23 children with mandibular body fracture were treated by microsplint and circumferential wiring from 2009 to 2012,the effects of treatment were assessed.Results:Treatment with microsplint and circumferential wiring did not injure perma-nent teeth germ.It showed many features,such as easy reduction of fractured bone segments,stable fixation,without interfere with eat-ing and benefit of mouth clearness.Conclusion:Microsplin and cicumferential wiring is effective for the treatment of mandibular body fracture in children.

  11. Experimental Investigation of Unsteady Flow in Circumferential Skewed Axial Fans at Off-design Conditions%叶片弯掠轴流风扇内瞬态流动的试验研究

    Institute of Scientific and Technical Information of China (English)

    金光远; 欧阳华; 杜朝辉

    2013-01-01

    对带有周向前弯和周向后弯叶片的低压轴流风扇,采用NI采集平台和双丝热线采集单元相结合的测量技术试验研究非设计工况下周向弯曲叶片的内部不稳定流动发展规律.对若干工况叶轮进出口三维流场进行详细测量,基于测量结果分析轴向、周向和径向方向的平均速度及湍流脉动速度,获得叶片周向弯曲叶轮内变工况下瞬态流场特性;通过对湍流度、雷诺应力和速度频谱分析,考察非设计工况下叶片周向弯曲叶轮固有的瞬态特性影响,分析进口来流扰动特征.研究结果显示NI采集平台和双丝热线采集单元整合的试验测量系统,成功测量低压周向弯曲叶轮变工况下的进出口三维流场,为多场同步测量提供技术参考;变工况下弯掠叶片对上下端壁区的不稳定流动具有显著的抑制作用,对于扩大稳定工作范围有着积极的作用;进口来流较高的湍流度主要存在近上下端壁区域,周向弯曲叶片对来流湍流度的影响主要集中在这两个区域;这些扰动主要集中于低频段,并呈宽频特性.%The unsteady characteristic of the inner flow to lower pressure axial fans with circumferential forward-skewed blades, backward-skewed blades is investigated experimentally at off-design conditions. The unsteady three-dimensional flow in circumferential skewed rotors upstream and downstream according to flow rates is successfully measured with a NI data collection platform and a hot-wire CTA unit (with a X probe). Based on the measurement results, axial, circumferential and radial components of the averaged velocity and turbulent velocity are analyzed to obtain the aerodynamic performance of circumferential skewed rotors; and the turbulent intensity, Reynold tensor and velocity spectrum are discussed to investigate the intrinsic unsteady flow in these rotors. The results show that the three-dimensional flow is captured by this measure system

  12. Extent-based incremental identification of reaction systems using concentration and calorimetric measurements

    OpenAIRE

    Srinivasan, Sriniketh; Bhatt, Nirav Pravinbhai; Billeter, Julien; Bonvin, Dominique

    2012-01-01

    Extent-based Incremental Model Identification (IMI) uses the concept of extent of reaction and the integral method of parameter estimation to identify reaction kinetics from transient concentration measurements. This study proposes to incorporate calorimetric measurements into the extent-based IMI approach. Calorimetric measurements are added to concentrationmeasurements for two main purposes: (i) to be able to estimate the reaction enthalpies when all the concentrations are measured, and (ii...

  13. Zonal Differences in Correlation Patterns Between Soil Organic Carbon and Climate Factors at Multi-extent

    Institute of Scientific and Technical Information of China (English)

    QIN Falyu; SHI Xuezheng; XU Shengxiang; YU Dongsheng; WANG Dandan

    2016-01-01

    Studying the relationship between climate factors and soil organic carbon (SOC) is vitally important.However,how SOC responses to climate (temperature and precipitation) at cohesive extents is poorly studied.Two transects of approximately the same length (transect P and transect T) were selected to examine the variation of SOC content in relation to mean annual temperature (MAT) and mean annual precipitation (MAP).The coefficients of partial correlation between SOC density and MAT (Rt) and MAP (Rp) were determined to quantify the relationships between SOC density and the two climate factors.The results indicated that for transect T,Rt was statistically significant once the extent level was greater than or equal to two fundamental extent units,while for transect P,Rp showed statistical significance only at extent levels which were greater than two fundamental extent units.At the same extent levels but in different transects,Rts exhibited no zonal difference,but Rps did once the extent level was greater than two fundamental extent units.Therefore,to study the relationship between SOC density and different climate factors,different minimum extent levels should be examined.The results of this paper could deepen the understanding of the impacts that SOC pool has on terrestrial ecosystem and global carbon cycling.

  14. 牙龈环切辅助牙周炎患牙正畸压入的效果观察%Effect of periodontitis involved teeth intrusion after circumferential supracrestal fibrotomy

    Institute of Scientific and Technical Information of China (English)

    袁建桥; 张月兰; 刘林嶓; 蔡留意; 张志伟

    2013-01-01

    Aim:To investigate the effect of intrusion of the teeth at the aligning and leveling stage after circumferen -tial supracrestal fibrotomy.Methods:During aligning and leveling stage of orthodontic therapy , 34 teeth with attachment loss were treated based on circumferential supracrestal fibrotomy .Parallel periapical radiographic technique was used to measure changes in crown-root ratio and cemento-enamel junction and alveolar crest height before and after treatment .Re-sults: The aligning and leveling stage of the orthodontic treatment with circumferential supracrestal fibrotomy spent 6-9 months.The overjet was improved ,the overbite became normal, the curve of spee was decreased ,and the periodontal health maintained as well.Specifically, the average amount of intrusion into the bone was about (0.73 ±0.56) mm, and crown-root ratio was improved by (13 ±12)%.Conclusion: The orthodontic treatment with circumferential supracrestal fibrotomy and the teeth intrusion is helpful for prognosis of periodontitis.%目的:探讨牙龈环切辅助牙周炎患牙正畸压低对牙周炎患牙预后的影响.方法:选取34颗伴有附着丧失的牙周炎患牙,牙周基础治疗后开展正畸治疗,在排齐整平阶段配合牙龈环切术,治疗前后使用平行投照根尖片来测量牙冠和牙根比例的变化以及釉牙骨质界-牙槽嵴顶高度的变化量.结果:牙龈环切辅助正畸经过6~9个月完成排齐整平,患牙覆盖改善,覆牙合正常,牙弓spee曲线减小,牙龈无红肿,牙周袋无加深,无明显探诊出血.患牙平均被压入(0.73±0.56)mm,冠根比例改善了(13±12)%.结论:牙龈环切术辅助牙周炎的正畸压入治疗有利于牙周炎的预后.

  15. 变工况下周向弯曲风扇叶顶涡声特性%Research of Aerodynamic Noise Source in Tip Region of Axial Fans with Circumferential Skewed Blades at Off-Design Conditions

    Institute of Scientific and Technical Information of China (English)

    金光远; 欧阳华; 胡彬彬; 吴亚东; 杜朝辉

    2011-01-01

    Aerodynamic noise source generated by tip leakage flow in circumferential skewed axial fans was studied by CFD simulation and experiments under off-design conditions. Relationship between tip leakage flow and aerodynamic noise was analyzed based on vortex-sound theory of low speed homentropic flow. Synergy between acoustic source and tip leakage vortex was discussed. Pressure test on casing wall and acoustic far field test were conducted to find how the different circumferential skewed direction control acoustic characteristics. The results show that the acoustic source generated by tip leakage vortex of circumferential skewed blades is an important noise source under off-design conditions. The angle between velocity vector and vortex vector controls the strength and the distribution of the acoustic source in tip clearance region. The acoustic source in tip clearance region is related with the acoustic far field under off-design conditions.%采用计算流体力学数值方法研究变工况下周向弯曲低压轴流风扇的叶顶泄漏流动特性,结合涡声理论分析泄漏涡与声源的协同特性,分析叶片不同周向弯曲方向对协同性的影响,并通过近场机匣壁面动态压力测量和远场声学测量,验证叶片周向弯曲方向对近远场声学特性的控制规律.研究表明,泄漏涡声源是周向弯曲叶轮小流量工况下的重要声源,速度矢量与涡矢量的夹角值控制叶顶区域声源强度和分布.近远场实验结果表明,泄漏涡声源与远场声学关系密切.

  16. 47 CFR 76.92 - Cable network non-duplication; extent of protection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable network non-duplication; extent of... RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.92 Cable network non-duplication; extent of protection....

  17. Extent of linkage disequilibrium in large breed dogs: chromosomal and breed variation

    Science.gov (United States)

    Purpose: Understanding extent of linkage disequilibrium (LD) is a crucial component for successful utilization of genome-wide association studies (GWAS). The extent of LD in the dog has been described based upon small marker sets in multiple breeds and studies. Understanding variation in LD on a per...

  18. 46 CFR 252.22 - Substantiality and extent of foreign-flag competition.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Substantiality and extent of foreign-flag competition... WORLDWIDE SERVICES Operation § 252.22 Substantiality and extent of foreign-flag competition. (a) Type and tonnage groupings. Foreign-flag competition shall be determined, as of January 1 of the year...

  19. Numerical Simulation of Transonic Fan Under Circumferential Inlet Distortion Using Harmonic Balance Method%跨声风扇周向畸变流动的谐波平衡法计算

    Institute of Scientific and Technical Information of China (English)

    杜鹏程; 宁方飞

    2012-01-01

    Simulating the unsteady flow of transonic fan under circumferential inlet distortion using conventional dual time stepping method would need multiple blade passages or the whole annulus in order to apply the direct periodic condition.Also,the initial transients of the solution cost most of the computation time to decay until it reaches a periodic steady state.This makes unsteady solutions extremely time consuming and hampers its application in fan blading design process.A fast calculation method is needed to estimate the impact of the circumferential inlet distortion on the fan aerodynamic performance.Therefore,the computation feasibility and the computation speed for the unsteady calculation of the fan under circumferential inlet distortion using harmonic balance method which adopts the phase shift condition were studied.Both the sine wave form and the square wave form inlet total pressure distortion were considered.For the sine wave form inlet distortion,only a small numbers of harmonics were needed to obtain comparable results to the dual time stepping method and a maximum factor of 48 speed-up could be achieved.As for the square wave form inlet distortion,more harmonics should be adopted to get accurate results and only a factor of 7 speed-up was achieved.The results demonstrate that the harmonic balance method can apply to the unsteady calculation of transonic fan under circumferential inlet distortion effectively and reduce the computation time significantly.%研究了采用"相位延迟"边界条件的谐波平衡法用于周向进气畸变计算的可行性及其计算效率,考虑了进气总压畸变形式为正弦波和方波的两种情况。对于正弦波形式的进气总压畸变采用较少阶数的谐波计算就可得到和双时间推进法相近的计算结果,计算速度最大可以提高48倍。对于方波形式的进气畸变,则需要采用更多阶数的谐波计算才能还原得到较准确的非定常流场,计算速度提高了7

  20. 斑点追踪技术评价缺血心肌短轴缩短率和圆周应变%Evaluation of Regional Shortening Fraction and Circumferential Strain in Patients with Myocardial Ischemia by Speckle Tracking Imaging

    Institute of Scientific and Technical Information of China (English)

    何艳; 王东平; 陈金国; 张娜; 杨体霞; 张军; 周利民

    2012-01-01

    目的 运用斑点追踪技术(STI)测量缺血心肌的短轴缩短率和圆周应变值,探讨其在诊断心肌缺血,评价心肌功能中的应用价值.方法 对29例心肌缺血患者(冠状动脉狭窄≥75%)和28例正常对照组(冠状动脉没有狭窄)分别行超声心动图检查,采集并记录左室短轴观(二尖瓣水平)的高帧频动态二维灰阶图像,应用二维应变分析软件进行脱机分析,系统自动将左室短轴分为前间隔、前壁、侧壁、后壁、下壁、后间隔6个节段,并给出应变曲线,分别测量各节段心肌的短轴缩短率和圆周应变值.结果 正常对照组的圆周应变曲线是负向峰值曲线,短轴缩短率曲线是正向峰值曲线,整组曲线排列较整齐;而心肌缺血组的应变曲线形态不规则.心肌缺血组圆周应变和短轴缩短率均低于正常对照组,差异有统计学意义(P<0.05).结论 斑点追踪技术能对心肌的二维应变进行定量分析,为临床诊断心肌缺血,评价心肌功能提供了无创性新方法.%Objective To evaluate the clinical value of speckle tracking imaging in the measurement of regional shortening fraction and circumferential strain in patients with myocardial ischemia. Methods Twenty-nine patients with myocardial ischemia and twenty-eight healthy subjects underwent echocardiography,high frame rate two-dimensional images were recorded from the left ventricular short-axis views at the levels of mitral annulus, regional shortening fraction and circumferential strain were measured in the left ventricular short-axis views using two-dimensional strain software. Results Circumferential strain curve, regional shortening fraction curve in healthy group changed regularly, while in myocardial ischemia patients, the curve changed irregularly. Regional shortening fraction and circumferential strain in myocardial ischemia patients showed significant reduction compared with normal myocardium(P<0.05). Conclusion Speckle

  1. 超声衍射时差法检测汽水管道环焊缝根部腐蚀减薄%Time-of-Flight-Diffraction Testing of Steam and Water Piping Circumferential Weld Roots Local Wall-thinning

    Institute of Scientific and Technical Information of China (English)

    钟志民; 张维; 汪明辉

    2016-01-01

    The field feedbacks show that the industry should pay more attention to secondary loop steam and water piping circumferential weld root flow-accelerated corrosion(FAC)in Nuclear Power Plants from field feedbacks. Without effective inspection and supervision, it will lead to serious consequences such as high energy pipe leakage or rupture. The weld root Ultrasonic Time of Flight Diffraction(TOFD) inspection principle and testing results were discussed in detail. It was shown that TOFD can be applied to inspect local wall-thinning ,caused by flow-accelerated corrosion, at circumferential weld roots of secondary loop steam & water piping in nuclear power plants.%工程经验反馈表明,过往关注较少的核电站二回路汽水管道环焊缝根部由流动加速腐蚀引起的局部减薄现象应引起业界重视,如不进行有效的检测和监督,也会导致高能管道泄漏或破裂.本文重点探讨了核电站二回路汽水管道环焊缝根部局部减薄超声衍射时差法的检测原理、试验情况.结果表明,超声衍射时差法可用于检测流动加速腐蚀引起的汽水管道环焊缝根部局部减薄.

  2. 内置式环形耐压液舱不同周向范围的应力分析%Stress analysis of inner annular pressure tank with different circumferential range

    Institute of Scientific and Technical Information of China (English)

    吴春芳; 吴梵; 刘令

    2016-01-01

    为研究内置式环形耐压液舱在液舱周向范围变化时的力学规律,采用 ANSYS有限元法对单壳体内置式耐压液舱进行了强度计算,对液舱与外界是否连通两种载荷工况下的应力情况进了比较分析。结果表明:在两种载荷工况下,液舱周向范围的变化对液舱应力变化的影响规律相同,但液舱内外相连通时的应力值更高;液舱周向范围280°左右时对结构的变形最为有利。%In order to research the mechanics law of inner annular pressure tank with the change in its circumferential range,a strength compilation method of mono-shell inner pressure tank is carried out based on finite element.The stress situations under two kinds of payloads conditions in the tank are compared and analyzed.The result shows that under the two different conditions,the change of tank circumferential range has the same effect on the change of tank shell stress according to the rule.The stress′value is greater when the liquid is connected to the outside.It is most favorable for the struc-ture′s deformation when the range is about 280°.

  3. Capturing heterogeneity: The role of a study area's extent for estimating mean throughfall

    Science.gov (United States)

    Zimmermann, Alexander; Voss, Sebastian; Metzger, Johanna Clara; Hildebrandt, Anke; Zimmermann, Beate

    2016-11-01

    The selection of an appropriate spatial extent of a sampling plot is one among several important decisions involved in planning a throughfall sampling scheme. In fact, the choice of the extent may determine whether or not a study can adequately characterize the hydrological fluxes of the studied ecosystem. Previous attempts to optimize throughfall sampling schemes focused on the selection of an appropriate sample size, support, and sampling design, while comparatively little attention has been given to the role of the extent. In this contribution, we investigated the influence of the extent on the representativeness of mean throughfall estimates for three forest ecosystems of varying stand structure. Our study is based on virtual sampling of simulated throughfall fields. We derived these fields from throughfall data sampled in a simply structured forest (young tropical forest) and two heterogeneous forests (old tropical forest, unmanaged mixed European beech forest). We then sampled the simulated throughfall fields with three common extents and various sample sizes for a range of events and for accumulated data. Our findings suggest that the size of the study area should be carefully adapted to the complexity of the system under study and to the required temporal resolution of the throughfall data (i.e. event-based versus accumulated). Generally, event-based sampling in complex structured forests (conditions that favor comparatively long autocorrelations in throughfall) requires the largest extents. For event-based sampling, the choice of an appropriate extent can be as important as using an adequate sample size.

  4. NOAA/NMC/CAC Arctic and Antarctic Monthly Sea Ice Extent, 1973-1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea ice extent from January 1973 through August 1990 was digitized from weekly operational sea ice charts produced by the Navy/NOAA Joint Ice Center. Charts were...

  5. Sea Ice Edge Location and Extent in the Russian Arctic, 1933-2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Ice Edge Location and Extent in the Russian Arctic, 1933-2006 data are derived from sea ice charts from the Arctic and Antarctic Research Institute (AARI),...

  6. Extent of soil with moderate phosphorus retention potential in the United States Pacific Northwest

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with moderate phosphorus retention potential in the Pacific...

  7. Extent of soil with high phosphorus retention potential in the United States Pacific Northwest

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with high phosphorus retention potential in the Pacific...

  8. Extent of soil with very high phosphorus retention potential in the United States Pacific Northwest

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with very high levels of phosphorus retention potential in...

  9. Extent of Corcoran Clay modified from Page (1986) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the areal extent of the Corcoran Clay Member of the Tulare Formation. The complex hydrologic system of the Central Valley is simulated...

  10. Extent of soil with low phosphorus retention potential in the United States Pacific Northwest

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the extent of soils with low phosphorus retention potential in the Pacific...

  11. Cook Inlet and Kenai Peninsula, Alaska ESI: ICE (Ice Extent Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of ice extent in Cook Inlet, Alaska. Vector lines in the data set represent 50 percent ice coverage. Location-specific type and...

  12. NOAA Climate Data Record (CDR) of Northern Hemisphere (NH) Snow Cover Extent (SCE), Version 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This NOAA Climate Data Record (CDR) is a record for the Northern Hemisphere (NH) Snow Cover Extent (SCE) spanning from October 4, 1966 to present, updated monthly...

  13. Shorty's Island Substrate Enhancement Pilot Project Extent, Kootenai River near Bonners Ferry, ID, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The substrate enhancement pilot project (SEPP) extent GIS layer represents an area where an artificial substrate will be placed. The artificial substrate, consisting...

  14. Myrtle Bend Substrate Enhancement Pilot Project Extent, Kootenai River near Bonners Ferry, ID, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The substrate enhancement pilot project (SEPP) extent GIS layer represents an area where an artificial substrate will be placed. The artificial substrate, consisting...

  15. TO WHAT EXTENT DOES THE DEGREE OF MEANINGFUL MODEL COMPLEXITY DEPEND ON OBSERVATION DATA?

    DEFF Research Database (Denmark)

    Brunner, Philip; Doherty, John; Christensen, Steen;

    We systematically quantify to what extent vadose zone parameters can be constrained by including different types of observation data in the calibration process. Observation data considered are hydraulic heads, soil saturation, evaporation and transpiration. Besides assessing parameter uncertainty...

  16. Numerical Simulation of Extent of Carbon Dioxide Plume Injected in the Gyeongsang Basin, Korea

    Science.gov (United States)

    Kihm, J.; Park, S.; Kim, J.

    2012-12-01

    A series of thermo-hydro-chemical numerical simulations was performed to evaluate extent of carbon dioxide plume injected in the Gyeongsang Basin, which is one of the prospective onshore sedimentary basins for geologic storage of carbon dioxide in Korea. The carbon dioxide plume extent is an important factor in estimating storage efficiency and thus storage capacity of carbon dioxide in a storage formation because it represents an actual volume of the storage formation, which is occupied by injected carbon dioxide. The carbon dioxide plume extent is also an essential component in risk analysis of geologic storage of carbon dioxide because most of thermo-hydro-mechanical-chemical responses to carbon dioxide injection occur within it. To evaluate impacts of injection scenarios (i.e., injection rate and period) of carbon dioxide and geological conditions (i.e., thickness and depth) and hydrogeochemical properties (i.e., porosity, intrinsic permeability, salt concentration in groundwater, and volume fraction of chlorite) of a storage formation on the carbon dioxide plume extent, a series of sensitivity tests was also performed. The numerical simulation results show that the carbon dioxide plume extent is significantly affected by such injection scenarios, geological conditions, and hydrogeochemical properties. The carbon dioxide plume extent increases as the injection rate (with a constant injection period) increases, and this trend does not change with time. The carbon dioxide plume extent decreases as the injection period (with a constant total injection amount) increases until about 50 years, while it is not sensitive to the injection period after about 50 years. The carbon dioxide plume extent also decreases as the thickness increases until about 100 years, while it is not sensitive to the thickness after about 100 years. In contrast, the carbon dioxide plume extent decreases as the depth increases, and this trend is intensified with time. On the other hand, the

  17. Extent, Causes, and Consequences of Small RNA Expression Variation in Human Adipose Tissue

    OpenAIRE

    Leopold Parts; Hedman, Åsa K.; Sarah Keildson; Knights, Andrew J.; Cei Abreu-Goodger; Martijn van de Bunt; José Afonso Guerra-Assunção; Nenad Bartonicek; Stijn van Dongen; Reedik Mägi; James Nisbet; Amy Barrett; Mattias Rantalainen; Nica, Alexandra C.; Quail, Michael A

    2012-01-01

    Small RNAs are functional molecules that modulate mRNA transcripts and have been implicated in the aetiology of several common diseases. However, little is known about the extent of their variability within the human population. Here, we characterise the extent, causes, and effects of naturally occurring variation in expression and sequence of small RNAs from adipose tissue in relation to genotype, gene expression, and metabolic traits in the MuTHER reference cohort. We profiled the expressio...

  18. Observed Differences between North American Snow Extent and Snow Depth Variability

    Science.gov (United States)

    Ge, Y.; Gong, G.

    2006-12-01

    Snow extent and snow depth are two related characteristics of a snowpack, but they need not be mutually consistent. Differences between these two variables at local scales are readily apparent. However at larger scales which interact with atmospheric circulation and climate, snow extent is typically the variable used, while snow depth is often assumed to be minor and/or mutually consistent compared to snow extent, though this is rarely verified. In this study, a new regional/continental-scale gridded dataset derived from field observations is utilized to quantitatively evaluate the relationship between snow extent and snow depth over North America. Various statistical methods are applied to assess the mutual consistency of monthly snow depth vs. snow extent, including correlations, composites and principal components. Results indicate that snow depth variations are significant in their own rights, and that depth and extent anomalies are largely unrelated, especially over broad high latitude regions north of the snowline. In the vicinity of the snowline, where precipitation and ablation can affect both snow extent and snow depth, the two variables vary concurrently, especially in autumn and spring. It is also found that deeper winter snow translates into larger snow-covered area in the subsequent spring/summer season, which suggests a possible influence of winter snow depth on summer climate. The observed lack of mutual consistency at continental/regional scales suggests that snowpack depth variations may be of sufficiently large magnitude, spatial scope and temporal duration to influence regional-hemispheric climate, in a manner unrelated to the more extensively studied snow extent variations.

  19. Influence of arterial compliance on presence and extent of ischaemia during stress echocardiography

    Science.gov (United States)

    Haluska, B A; Matthys, K; Fathi, R; Rozis, E; Carlier, S G; Marwick, T H

    2006-01-01

    Objective To seek an association between total arterial compliance (TAC) and the extent of ischaemia at stress echocardiography. Design Cohort study. Setting Regional cardiac centre. Methods 255 consecutive patients (147 men; mean (SD) age 58 (8)) presenting for stress echocardiography for clinical indications were studied. Wall motion score index (WMSI) was calculated and ischaemia was defined by an inducible or worsening wall motion abnormality. Peak WMSI was used to reflect the extent of dysfunction (ischaemia or scar), and ΔWMSI was indicative of extent of ischaemia. TAC was assessed at rest by simultaneous radial applanation tonometry and pulsed wave Doppler in all patients. Results Ischaemia was identified by stress echocardiography in 65 patients (25%). TAC was similar in the groups with negative and positive echocardiograms (1.08 (0.41) v 1.17 (0.51) ml/mm Hg, not significant). However, the extent of dysfunction was associated with TAC independently of age, blood pressure, risk factors, and use of a β blocker. Moreover, the extent of ischaemia was determined by TAC, risk factors, and use of a β blocker. Conclusion While traditional cardiovascular risk factors are strong predictors of ischaemia on stress echocardiography, TAC is an independent predictor of the extent of ischaemia. PMID:16365349

  20. 袖状蒂岛状环形包皮瓣尿道成形术一期修复会阴型尿道下裂%One-stage urethroplasty with circumferential vascular pedicle preputial island flap for perineal hypospadias

    Institute of Scientific and Technical Information of China (English)

    朱再生; 吴汉; 李瑞阳; 汪定海

    2010-01-01

    Objective To report the treatment of perineal hypospadias with one-stage urethroplaty with circumferential vascular pedicle preputial island flap. Methods A circumferential incision was made proximal to the corona and the urethral plate to correct chordee. A U-shaped skin incision was then made surrounding the meatus, and extended to the dorsal prepuce and parallel to the first incision. The tissue between the prepuce and dartos was dissected on the dorsum of penis to fix the prepuce as a neourethra.After mobilizing the loop shaped skin flap through the button-hole of the pedicle, the internal and external sides of the loop were sutured to construct a new urethra, the catheter was removed 10-14 days (mean,12.8 days ) after operation. Results Since 1997, 22 patients with perineal hypospadias were treated.Primary healing was achieved in 18 cases(81.8% ). Fistula happened in 4 patients. Among them, one case with meatal stenosis was treated with dilatation. Another 3 patients were reoperated. The neourethral flap was 3.50-18.00 cm (mean, 9.43 cm) in length. All patients were followed up for more than 6 months. Good cosmetic appearance was achieved in 72. 7% (16/22) of the patients. Conclusions The circumferential vascular pedicle preputial island flap has advantages of good blood supply and autograft for new meatus, which allows the chordee correction and urethroplaty at one stage. It is a good method for the treatment of perineal hypospadias with severe chordee and penoscrotal transposition.%目的 探讨袖状蒂岛状环形包皮瓣尿道成形术一期修复会阴型尿道下裂的临床效果.方法 距冠状沟0.5 cm处环形切开包皮内板和尿道板,脱套以纠正阴茎下曲.沿尿道板两侧平行切开,近端绕尿道口后会合,呈U形,远端环绕包皮到背侧,使新尿道皮瓣呈环状.解剖供应皮瓣的深层皮下组织与阴茎皮肤,形成血管蒂.经纽扣样孔隙,转移环状皮瓣至腹侧.缝合岛状环形皮瓣的内、外缘,形

  1. Factors influencing the spatial extent of mobile source air pollution impacts: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Levy Jonathan I

    2007-05-01

    Full Text Available Abstract Background There has been growing interest among exposure assessors, epidemiologists, and policymakers in the concept of "hot spots", or more broadly, the "spatial extent" of impacts from traffic-related air pollutants. This review attempts to quantitatively synthesize findings about the spatial extent under various circumstances. Methods We include both the peer-reviewed literature and government reports, and focus on four significant air pollutants: carbon monoxide, benzene, nitrogen oxides, and particulate matter (including both ultrafine particle counts and fine particle mass. From the identified studies, we extracted information about significant factors that would be hypothesized to influence the spatial extent within the study, such as the study type (e.g., monitoring, air dispersion modeling, GIS-based epidemiological studies, focus on concentrations or health risks, pollutant under study, background concentration, emission rate, and meteorological factors, as well as the study's implicit or explicit definition of spatial extent. We supplement this meta-analysis with results from some illustrative atmospheric dispersion modeling. Results We found that pollutant characteristics and background concentrations best explained variability in previously published spatial extent estimates, with a modifying influence of local meteorology, once some extreme values based on health risk estimates were removed from the analysis. As hypothesized, inert pollutants with high background concentrations had the largest spatial extent (often demonstrating no significant gradient, and pollutants formed in near-source chemical reactions (e.g., nitrogen dioxide had a larger spatial extent than pollutants depleted in near-source chemical reactions or removed through coagulation processes (e.g., nitrogen oxide and ultrafine particles. Our illustrative dispersion model illustrated the complex interplay of spatial extent definitions, emission rates

  2. Mapping US Urban Extents from MODIS Data Using One-Class Classification Method

    Directory of Open Access Journals (Sweden)

    Bo Wan

    2015-08-01

    Full Text Available Urban areas are one of the most important components of human society. Their extents have been continuously growing during the last few decades. Accurate and timely measurements of the extents of urban areas can help in analyzing population densities and urban sprawls and in studying environmental issues related to urbanization. Urban extents detected from remotely sensed data are usually a by-product of land use classification results, and their interpretation requires a full understanding of land cover types. In this study, for the first time, we mapped urban extents in the continental United States using a novel one-class classification method, i.e., positive and unlabeled learning (PUL, with multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS data for the year 2010. The Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS night stable light data were used to calibrate the urban extents obtained from the one-class classification scheme. Our results demonstrated the effectiveness of the use of the PUL algorithm in mapping large-scale urban areas from coarse remote-sensing images, for the first time. The total accuracy of mapped urban areas was 92.9% and the kappa coefficient was 0.85. The use of DMSP-OLS night stable light data can significantly reduce false detection rates from bare land and cropland far from cities. Compared with traditional supervised classification methods, the one-class classification scheme can greatly reduce the effort involved in collecting training datasets, without losing predictive accuracy.

  3. The Value of Glioma Extent of Resection in the Modern Neurosurgical Era

    Directory of Open Access Journals (Sweden)

    Douglas A Hardesty

    2012-10-01

    Full Text Available Objective: There remains no general consensus in the neurosurgical oncology literature regarding the role of extent of glioma resection in improving patient outcome. Although the value of resection in establishing a diagnosis and alleviating mass effect is clear, there is less certainty in ascertaining the influence of extent of resection. Here, we review the recent literature to synthesize a comprehensive review of the value of extent of resection for gliomas in the modern neurosurgical era.Methods: We reviewed every major peer-reviewed clinical publication since 1990 on the role of extent of resection in glioma outcome.Results: Thirty-two high-grade glioma articles and 11 low-grade glioma articles were examined in terms of quality of evidence, expected extent of resection, and survival benefit.Conclusions: Despite limitations in the quality of data, mounting evidence suggests that more extensive surgical resection is associated with longer life expectancy for both low- and high-grade newly-diagnosed gliomas.

  4. Successes and challenges from formation to implementation of eleven broad-extent conservation programs

    Science.gov (United States)

    Beever, Erik A.; Bradford, John B.; Germino, Matthew J.; Mattsson, Brady J.; Post van der Burg, Max; Brunson, Mark

    2014-01-01

    Integration of conservation partnerships across geographic, biological, and administrative boundaries is increasingly relevant because drivers of change, such as climate shifts, transcend these boundaries. We explored successes and challenges of established conservation programs that span multiple watersheds and consider both social and ecological concerns. We asked representatives from a diverse set of 11 broadextent conservation partnerships in 29 countries 17 questions that pertained to launching and maintaining partnerships for broad-extent conservation, specifying ultimate management objectives, and implementation and learning. Partnerships invested more funds in implementing conservation actions than any other aspect of conservation, and a program’s context (geographic extent, United States vs. other countries, developed vs. developing nation) appeared to substantially affect program approach. Despite early successes of these organizations and benefits of broad-extent conservation, specific challenges related to uncertainties in scaling up information and to coordination in the face of diverse partner governance structures, conflicting objectives, and vast uncertainties regarding future system dynamics hindered long-term success, as demonstrated by the focal organizations. Engaging stakeholders, developing conservation measures, and implementing adaptive management were dominant challenges. To inform future research on broad-extent conservation, we considered several challenges when we developed detailed questions, such as what qualities of broad-extent partnerships ensure they complement, integrate, and strengthen, rather than replace, local conservation efforts and which adaptive management processes yield actionable conservation strategies that account explicitly for dynamics and uncertainties regarding multiscale governance, environmental conditions, and knowledge of the system?

  5. Treatment of periodontal disease by double circumferential fibrotomy combined with orthodontic method%二次嵴上纤维环切术结合正畸治疗牙周病的临床观察

    Institute of Scientific and Technical Information of China (English)

    董莹丽; 张月兰; 袁建桥

    2015-01-01

    目的:探讨二次嵴上纤维环切术对牙周病患牙牙周附着的影响。方法:选取4例共22颗前牙患有中度牙周炎的成人患者,一侧患牙施行1次嵴上纤维环切(T1组),另一侧行2次环切(T2组)。排齐整平阶段前后分别拍摄患牙的平行投照 X 线片,测量釉牙骨质界至牙槽嵴顶的距离(CEJ-AC),冠根比和牙根长度。并检测患牙的相关牙周指数。采用配对 t 检验进行统计学分析。结果:T2组 CEJ-AC 和冠根比下降大于 T1组(P <0.01),牙周指数的变化与 T1组相比无统计学差异(P >0.05)。结论:二次牙龈环切能增加患牙的牙周附着及牙槽骨相对高度,合理的正畸压入不会造成牙周炎患牙牙根吸收。%Objective:To explore the effects of double circumferential fibrotomy(CF)in the improvement of periodontal attachment of the teeth with periodontal disease.Methods:22 migrated incisors of 4 adults were randomly assigned to one-time CF group (T1 )and double CF group(T2)by center line.Periapical intraoral radiographic examination was performed using paralleling technique at pre-and post-leveling-alignment stage of the teeth.Root length,crown-root ratio and the distance of CEJ-AC were measured.The periodontal in-dicators were also recorded during the orthodontic treatment.Data were statistically analysed by comparative t-test.Results:CEJ-AC and crown root ratio reduction was greater in T2 group than those in T1 group(P 0.05).Conclusion:Double circumferential fibrotomy can improve periodontal attachment, reasonable orthodontic force does not lead to remarkable root resorption of the periodontitis inflicted teeth.

  6. Basis椎弓根螺钉固定加环形植骨融合治疗腰椎滑脱%Basis pedicle screw fixation and posterior instrumented circumferential fusion for the treatment of lumbar spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    董福龙; 申才良; 张建湘; 汤健; 杨庆国; 江曙

    2011-01-01

    Objective To summarize curative effects of the decompressive laminectomy by posterior approach, reduc tion of spondylolisthesis fixed with Basis pedicle screw and posterior instrumented circumferential fusion in the treat ment of lumbar spondylolisthesis. Methods Thirty-two patients with lumbar spondylolisthesis treated with posterior instrumented circumferential fusion were studied retrospectively. Results All the patients received follow-up for 4 ~ 25 months. Symptoms were disappeared after operations in all the patients. The postoperative X-ray films showed that 29 patients obtained complete reduction,3 partly reduction. This surgical methods produced satisfactory outcomes with the 100% osseous fusion. All the bone grafts were fusion, without screws loosening or breakage or internal fixation loosing was found. Based on Hou Shu-xun Criteria for therapeutical evalution, the efficacy was as follows: excellent in 23 cases,good in 7,and fair in 2,the rate of excellent and good was 94%. Conclusions Posterior instrumented cir cumferential fusion with Basis pedicle screw is an effective method for treating severe lumbar spondylolisthesis.%目的 探讨后路腰椎管减压、Basis椎弓根螺钉系统复位固定加环形植骨融合治疗腰椎滑脱症的疗效.方法 对32例腰椎滑脱症患者行后路腰椎管减压Basis椎弓根螺钉复位固定加环形植骨融合术.结果 32例均获随访,时间4~25个月.患者术后症状均消失,X线片示29例滑脱完全复位,3例部分复位.所有患者均达骨性融合,无椎弓根钉松动、断裂及再滑脱现象.根据侯树勋等疗效评定标准评定:优23例,良7例,可2例,优良率94%.结论 Basis椎弓根固定系统复位固定加环形植骨融合治疗腰椎滑脱症临床疗效满意,可作为治疗严重腰椎滑脱的首选方法.

  7. Extent of Surgery Does Not Influence 30-Day Mortality in Surgery for Metastatic Bone Disease

    DEFF Research Database (Denmark)

    Sørensen, Michala Skovlund; Hindsø, Klaus; Hovgaard, Thea Bechmann

    2016-01-01

    retrospectively identified 270 consecutive patients who underwent joint replacement surgery or intercalary spacing for skeletal metastases in the appendicular skeleton from January 1, 2003 to December 31, 2013. We collected intraoperative (duration of surgery, extent of bone resection, and blood loss......Estimating patient survival has hitherto been the main focus when treating metastatic bone disease (MBD) in the appendicular skeleton. This has been done in an attempt to allocate the patient to a surgical procedure that outlives them. No questions have been addressed as to whether the extent...... of the surgery and thus the surgical trauma reduces survival in this patient group. We wanted to evaluate if perioperative parameters such as blood loss, extent of bone resection, and duration of surgery were risk factors for 30-day mortality in patients having surgery due to MBD in the appendicular skeleton. We...

  8. Prevalence, Vascular Distribution, and Multiterritorial Extent of Subclinical Atherosclerosis in a Middle-Aged Cohort

    DEFF Research Database (Denmark)

    Fernández-Friera, Leticia; Peñalvo, José L; Fernández-Ortiz, Antonio

    2015-01-01

    BACKGROUND: Data are limited on the presence, distribution, and extent of subclinical atherosclerosis in middle-aged populations. METHODS AND RESULTS: The PESA (Progression of Early Subclinical Atherosclerosis) study prospectively enrolled 4184 asymptomatic participants 40 to 54 years of age (mean...... age, 45.8 years; 63% male) to evaluate the systemic extent of atherosclerosis in the carotid, abdominal aortic, and iliofemoral territories by 2-/3-dimensional ultrasound and coronary artery calcification by computed tomography. The extent of subclinical atherosclerosis, defined as presence of plaque...... or coronary artery calcification ≥1, was classified as focal (1 site affected), intermediate (2-3 sites), or generalized (4-6 sites) after exploration of each vascular site (right/left carotids, aorta, right/left iliofemorals, and coronary arteries). Subclinical atherosclerosis was present in 63...

  9. 241-AY-101 Tank Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Gunter, Jason R.

    2013-08-26

    This report provides the results of an extent of condition construction history review for tank 241-AY-101. The construction history of tank 241-AY-101 has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In tank 241-AY-101, the second double-shell tank constructed, similar issues as those with tank 241-AY-102 construction reoccurred. The overall extent of similary and affect on tank 241-AY-101 integrity is described herein.

  10. Surface Water and Flood Extent Mapping, Monitoring, and Modeling Products and Services for the SERVIR Regions

    Science.gov (United States)

    Anderson, Eric

    2016-01-01

    SERVIR is a joint NASA - US Agency for International Development (USAID) project to improve environmental decision-making using Earth observations and geospatial technologies. A common need identified among SERVIR regions has been improved information for disaster risk reduction and in specific surface water and flood extent mapping, monitoring and forecasting. Of the 70 SERVIR products (active, complete, and in development), 4 are related to surface water and flood extent mapping, monitoring or forecasting. Visit http://www.servircatalog.net for more product details.

  11. 241-AW Tank Farm Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Gunter, Jason R.; Reeploeg, Gretchen E.

    2013-11-19

    This report provides the results of an extent of condition construction history review for the 241-AW tank farm. The construction history of the 241-AW tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AW tank farm, the fourth double-shell tank farm constructed, similar issues as those with tank 241-AY-102 construction occured. The overall extent of similary and affect on 241-AW tank farm integrity is described herein.

  12. Thermoluminescence glow curve involving any extent of retrapping or any order of kinetics

    Indian Academy of Sciences (India)

    Jai Prakash

    2013-09-01

    Adirovitch set of equations has been modified to explain the mechanisms involved in thermoluminescence (TL) glow curve. A simple model is proposed which explains the occurrence of TL glow curve involving any extent of retrapping or any order of kinetics. It has been observed that the extents of recombination and simultaneous rewrapping decide the order of kinetics involved. TL decay parameters, order of kinetics and initial concentration of trapped electrons per unit volume are evaluated easily and conveniently. It has been observed that retrapping increases with increasing order of kinetics.

  13. Numerical Simulation Study of Natural Convection Heat Transfer Performance of Circumferential Finned Tube%环形翅片管自然对流传热特性的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    李家乐

    2013-01-01

    利用FLUENT数值模拟方法,研究了自然对流条件下环形翅片管几何参数对其对流换热性能的影响.结果表明:随翅片间距的增大,单位长度散热量先增大后减小,表面平均自然对流换热系数及单位面积散热量先增大后基本稳定不变;翅片厚度对换热性能的影响随间距变化而变化.通过模拟计算,为自然对流条件下翅片管的优化设计提供了参考.%Applying numerical simulation, the paper studies the effect of fin spacing and fin thickness of circumferential finned tube on natural convection heat transfer performance. The results indicate that, with the increase of fin spacing, unit length heat dissipating capacity increases at the previous period and decreases at the later period. The average surface convection coefficient of heat transfer and unit surface area heat dissipating capacity increase at first and then keep constant. The effect of fin thickness on heat transfer performance changes along with the fin spacing. By simulation, it provides reference to the optimization design of finned tube.

  14. Meta-analysis of lumbar posterolateral fusion versus circumferential fusion in the treatment of the lumbar disease%腰椎后外侧融合与360°融合的系统评价

    Institute of Scientific and Technical Information of China (English)

    崔璀; 朱悦; 韩秀鑫

    2009-01-01

    目的 对腰椎后外侧融合与360°融合治疗腰椎疾病的疗效进行系统对比评价.方法 计算机检索MEDLINE(1966.1-2007.12,Ovid检索平台)、EMBASE(1984.1-2007.12)、Cochrance Central Register of Controlled Trial(4th Quarter 2007)、中国生物医学文献数据库(1986.1-2007.12)等,手工检索Spine、European SPine Jurnal、The Journat of Bone and Joint Surgery、、、等相关期刊,检索两种融合术式的相关病例研究结果、综述等相关内容,并评价纳入研究的方法学质量,采用RevMan 5.0,5.0软件对总体疗效、融合率、二次手术率、并发症发生率、平均手术时间、手术出血量进行荟萃分析.结果 有4个临床随机对照试验(RCT)符合纳入标准,共437例患者.在融合率[OR 0.47,95%CI(0.24,0.94)]、并发症发生率[OR 0.53,95%CI(0.32,0.87)]、术中出血量[加权均数差值(WMD)=-349.95,95%CI(-561.64,-138.26)]方面,360°融合组要高于后外侧融合组,差异具有统计学意义(P=0.030、0.010、0.001);在二次手术率[OR 2.28,95%CI(1.30,3.98)]方面,后外侧融合组要高于360°融合组,差异具有统计学意义(P=0.004);在总体疗效[OR 1.04,95%CI(0.64,1.68)]和手术时间[WMD=-90.24,95%CI(-190.20,9.71)]上,两组差异无统计学意义(P=0.870、0.080).结论 360°融合组相比于后外侧融合组,能显著提高融合率,降低二次手术率,但并发症、术中出血量也显著高于后者.本研究结果尚需要多中心大样本RCT进一步证实.%Objective To evaluate the efficacy of lumbar posterolateral fusion versus circumferential fusion in the treatment of the lumbar disease. Methods Searched MEDLINE(January, 1966 to December, 2007), EMBASE (January, 1984 to December, 2007), Coehrance Central Register of Controlled Trial (4th Quarter 2007), The China Biological Medicine Database (1984 to December, 2007), and hand searched several related journals, such as Spine, European Spine Journal, The Journal of Bone and Joint Surgery, Chinese

  15. Regeneración ósea de un defecto circunferencial de tres paredes con hueso autólogo Autologous bone regeneration of an circumferential three walls defect

    Directory of Open Access Journals (Sweden)

    N. Escudero Castaño

    2008-08-01

    Full Text Available La periodontitis provoca, a lo largo de su proceso evolutivo, un deterioro de los tejidos periodontales, entreellos del hueso alveolar. En la mayoría de las ocasiones, la progresión de esta enfermedad puede ocasionar defectos óseos. Su tratamiento consistirá en la eliminación de los factores etiológicos y recuperar, en la medida de loposible, la estructura perdida mediante diferentes técnicas regenerativas o resectivas. En el presente artículo, se muestra una opción para el tratamiento de un defecto óseo circunferencial de tres paredes, comparándolo condiferentes alternativas de tratamiento para combatir este defecto.The periodontal disease causes, along the evolutive process of the illness, a damage of periodontal tissues,including the alveolar bone; in many times, the evolution of the pathology makes irregular bone deformities. The treatment of that disease could be to eliminate the etiological factors and to recuperate as much as possible, the missed structure with regenerative and resectives techniques. In this article, we will set up a clinical case where we will describe a treatment option of a circumferential bone defect and we will compare that treatment with others alternatives.

  16. 41 CFR 102-118.60 - To what extent must my agency use electronic commerce?

    Science.gov (United States)

    2010-07-01

    ... agency use electronic commerce? 102-118.60 Section 102-118.60 Public Contracts and Property Management... Services § 102-118.60 To what extent must my agency use electronic commerce? Your agency must use electronic commerce in all areas of your transportation program. This includes the use of electronic...

  17. To what extent do fiscal regimes equalize opportunities for income acquisition among citizens?

    DEFF Research Database (Denmark)

    Roemer, John E; Aaberge, Rolf; Colombino, Ugo;

    2003-01-01

    This paper employs the theory of equality of opportunity, described in Roemer’s book (Equality of Opportunity, Harvard University Press, 1998), to compute the extent to which tax-and-transfer regimes in 11 countries equalize opportunities among citizens for income acquisition. Roughly speaking...

  18. 9 CFR 381.70 - Ante mortem inspection; when required; extent.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Ante mortem inspection; when required... AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Ante Mortem Inspection § 381.70 Ante mortem inspection; when required; extent. (a) An ante mortem inspection of...

  19. Some Criticisms against Exam Questions: To What Extent Can Mythic, Romantic and Philosophical Questions Be Used?

    Science.gov (United States)

    Seker, Hasan

    2016-01-01

    In the present study, some of the pre-service teachers' criticisms against their exams were investigated. Moreover, as an alternative, to what extent philosophical, romantic and mythic questions could be used was also looked at. The study group consists of 117 pre-service teachers from the classroom teacher education. In the study, it was…

  20. Use of multivariate indicator kriging methods for assessing groundwater contamination extents for irrigation.

    Science.gov (United States)

    Jang, Cheng-Shin

    2013-05-01

    Multivariate geostatistical approaches have been applied extensively in characterizing risks and uncertainty of pollutant concentrations exceeding anthropogenic regulatory limits. Spatially delineating an extent of contamination potential is considerably critical for regional groundwater resources protection and utilization. This study used multivariate indicator kriging (MVIK) to determine spatial patterns of contamination extents in groundwater for irrigation and made a predicted comparison between two types of MVIK, including MVIK of multiplying indicator variables (MVIK-M) and of averaging indicator variables (MVIK-A). A cross-validation procedure was adopted to examine the performance of predicted errors, and various probability thresholds used to calculate ratios of declared pollution area to total area were explored for the two MVIK methods. The assessed results reveal that the northern and central aquifers have excellent groundwater quality for irrigation use. Results obtained through a cross-validation procedure indicate that MVIK-M is more robust than MVIK-A. Furthermore, a low ratio of declared pollution area to total area in MVIK-A may result in an unrealistic and unreliable probability used to determine extents of pollutants. Therefore, this study suggests using MVIK-M to probabilistically determine extents of pollutants in groundwater.

  1. Investigation of temporal change in glacial extent of Chitral watershed using Landsat data.

    Science.gov (United States)

    Naeem, Usman Ali; Shamim, Muhammad Ali; Ejaz, Naeem; Ur Rehman, Habib; Mustafa, Umer; Hashmi, Hashim Nisar; Ghumman, Abdul Razzaq

    2016-01-01

    Glaciers are also known as solid reservoirs, and in this regard, Pakistan is a blessed country to have enriched glaciers. The change in glacial extent becomes very crucial for rivers whose discharges are associated with glacier melt. Even a little change in the glacial extent may bring a significant change in the resulting river flows. Considering climate change scenarios, many researchers have predicted future flows in such catchments. But in almost all such studies, the reduction in the glaciers is not normally based on any rational. Therefore, research is needed in order to estimate how glaciers are actually behaving under the change of temperature and precipitations to better estimate the future flows. For this purpose, Chitral watershed was considered as the study area. The seasonal change in the snow extent was estimated by using MODIS data for various years that helped to identify the month with minimum glacial extent. With the help of remote sensing, unsupervised classification was performed to estimate the glacier area in Chitral watershed. The results show a definite receding trend with respect to time in the glaciers of the region for the past decade.

  2. 76 FR 60504 - Guidance for Industry on Time and Extent Applications for Nonprescription Drug Products...

    Science.gov (United States)

    2011-09-29

    ... HUMAN SERVICES Food and Drug Administration (Formerly 2004D-0027) Guidance for Industry on Time and... a guidance for industry entitled ``Time and Extent Applications for Nonprescription Drug Products... in 21 CFR part 25 and the guidance for industry entitled ``Environmental Assessment of Human Drug...

  3. The relationship between sex hormones and extent of coronary artery disease in postmenopausal women

    Institute of Scientific and Technical Information of China (English)

    Odgerel Tumur; HAN Jiang-li; YANG Chi-sun; MAO Jie-ming

    2007-01-01

    @@ The prevalence of coronary artery disease (CAD) in women increases with menopause. Results from the studies on the role of endogenous sex hormones on CAD in postmenopausal women are conflicting.1,2 The present study evaluated the relationship between endogenous sex hormones and extent of CAD in postmenopausal women and the associations of sex hormones with CAD risk factors.

  4. Adjudication and Justification: To What Extent Should the Exluded Be Included in the Judge's Decision

    NARCIS (Netherlands)

    Klink, van B.M.J.

    2016-01-01

    As follows from the Rule of Law, the judge has to justify herdecision. In contemporary legal and social theory, it is arguedthat she should somehow give recognition to arguments andviewpoints that have been excluded from the final decision. Inmy paper, I will address the question why, to what extent

  5. A Portrait of Family Involvement during Head Start: Nature, Extent, and Predictors

    Science.gov (United States)

    Hindman, Annemarie H.; Miller, Alison L.; Froyen, Laura C.; Skibbe, Lori E.

    2012-01-01

    Family involvement, an important resource for early learning among children in poverty, is a primary focus of the Head Start preschool program. The current study examined the extent to which families in Head Start were involved in children's learning at home, in the community, and at school, as well as the child, family, and center factors that…

  6. Does the Extent of Problem Familiarity Influence Students' Learning in Problem-Based Learning?

    Science.gov (United States)

    Sockalingam, Nachamma; Schmidt, Henk G.

    2013-01-01

    This study investigated the relationship between problem familiarity and students' learning in a problem-based course. Problem familiarity in this study refers to the extent to which a problem fits with students' prior knowledge and experiences. As part of regular course work, 172 students were given two problems on different occasions.…

  7. The visual extent of an object: suppose we know the object locations

    NARCIS (Netherlands)

    Uijlings, J.R.R.; Smeulders, A.W.M.; Scha, R.J.H.

    2012-01-01

    The visual extent of an object reaches beyond the object itself. This is a long standing fact in psychology and is reflected in image retrieval techniques which aggregate statistics from the whole image in order to identify the object within. However, it is unclear to what degree and how the visual

  8. The Extent of Skills Mismatch among Childhood Education Graduates of Princess Alia University College

    Science.gov (United States)

    Nashash, Hyam M.

    2015-01-01

    This study is aimed at investigating the extent of skill mismatch between the skills the childhood education graduates at Al-Balqa Applied University--Princess Alia University College acquired during their studies and those demanded in the labor market. The descriptive survey design was adopted and the purposive sampling technique was employed to…

  9. Extent of Utilizing Electrical Equipment in Poultry Production in Ebonyi State

    Science.gov (United States)

    Ogba, E. I.; Ogbu, J. E.

    2016-01-01

    This study was designed to investigate the extent of utilizing electrical equipment in poultry production in the rural areas of Ebonyi State, Nigeria. A survey research design was adopted for the study. Three research questions guided the study. The population for the study was 46 respondents comprising 16 Extension agents and 30 Poultry farmers.…

  10. Interdependence between measures of extent and severity of myocardial perfusion defects provided by automatic quantification programs

    DEFF Research Database (Denmark)

    El-Ali, Henrik Hussein; Palmer, John; Carlsson, Marcus;

    2005-01-01

    To evaluate the accuracy of the values of lesion extent and severity provided by the two automatic quantification programs AutoQUANT and 4D-MSPECT using myocardial perfusion images generated by Monte Carlo simulation of a digital phantom. The combination between a realistic computer phantom...

  11. The Extent and Nature of Need for Mealtime Support among Adults with Intellectual Disabilities

    Science.gov (United States)

    Ball, S. L.; Panter, S. G.; Redley, M.; Proctor, C.-A.; Byrne, K.; Clare, I. C. H.; Holland, A. J.

    2012-01-01

    Background: For many adults with an intellectual disability (ID), mealtimes carry significant health risks. While research and allied clinical guidance has focused mainly on dysphagia, adults with a range of physical and behavioural difficulties require mealtime support to ensure safety and adequate nutrition. The extent of need for and nature of…

  12. To What Extent Do Student Teachers Have the Values Required for the Profession?

    Science.gov (United States)

    Morales-Vives, Fabia; Camps, Misericordia; Lorenzo-Seva, Urbano

    2013-01-01

    The main objective of this study is to determine to what extent the values held by student teachers at the start of a university degree programme coincide with the values that practising teachers consider important for their profession. Our findings show that student teachers and practising teachers have different value profiles, and that there is…

  13. The Nature, Extent and Causes of Abuse of Children with Disabilities in Schools in Botswana

    Science.gov (United States)

    Shumba, Almon; Abosi, Okey C.

    2011-01-01

    Studies show that the exact number of children with disabilities in Botswana is unknown. A study on child abuse sought to determine: the forms of child abuse perpetrated on children with disabilities; the extent of child abuse; and the causes of child abuse of children with disabilities. A questionnaire on child abuse was adapted and used to…

  14. Total Quality Management in Secondary Schools in Kenya: Extent of Practice

    Science.gov (United States)

    Ngware, Moses Waithanji; Wamukuru, David Kuria; Odebero, Stephen Onyango

    2006-01-01

    Purpose: To investigate the extent to which secondary schools practiced aspects of total quality management (TQM). Design/methodology/approach: A cross-sectional research design was used in this study. A sample of 300 teachers in a residential session during a school holiday provided their perceptions on the practice of TQM in their schools. Data…

  15. 23 CFR 636.212 - To what extent must tradeoff decisions be documented?

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false To what extent must tradeoff decisions be documented? 636.212 Section 636.212 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Selection Procedures, Award Criteria § 636.212...

  16. 26 CFR 1.731-1 - Extent of recognition of gain or loss on distribution.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Extent of recognition of gain or loss on distribution. 1.731-1 Section 1.731-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... recognition of gain or loss on distribution. (a) Recognition of gain or loss to partner—(1) Recognition...

  17. Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi-Naini

    2015-02-01

    Full Text Available Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5 MHz ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r2 value of 0.71 (P < .0001. The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r2 = 0.764, P < .05, implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.

  18. Extent of Surgery Does Not Influence 30-Day Mortality in Surgery for Metastatic Bone Disease

    Science.gov (United States)

    Sørensen, Michala Skovlund; Hindsø, Klaus; Hovgaard, Thea Bechmann; Petersen, Michael Mørk

    2016-01-01

    Abstract Estimating patient survival has hitherto been the main focus when treating metastatic bone disease (MBD) in the appendicular skeleton. This has been done in an attempt to allocate the patient to a surgical procedure that outlives them. No questions have been addressed as to whether the extent of the surgery and thus the surgical trauma reduces survival in this patient group. We wanted to evaluate if perioperative parameters such as blood loss, extent of bone resection, and duration of surgery were risk factors for 30-day mortality in patients having surgery due to MBD in the appendicular skeleton. We retrospectively identified 270 consecutive patients who underwent joint replacement surgery or intercalary spacing for skeletal metastases in the appendicular skeleton from January 1, 2003 to December 31, 2013. We collected intraoperative (duration of surgery, extent of bone resection, and blood loss), demographic (age, gender, American Society of Anesthesiologist score [ASA score], and Karnofsky score), and disease-specific (primary cancer) variables. An association with 30-day mortality was addressed using univariate and multivariable analyses and calculation of odds ratio (OR). All patients were included in the analysis. ASA score 3 + 4 (OR 4.16 [95% confidence interval, CI, 1.80–10.85], P = 0.002) and Karnofsky performance status below 70 (OR 7.34 [95% CI 3.16–19.20], P < 0.001) were associated with increased 30-day mortality in univariate analysis. This did not change in multivariable analysis. No parameters describing the extent of the surgical trauma were found to be associated with 30-day mortality. The 30-day mortality in patients undergoing surgery for MBD is highly dependent on the general health status of the patients as measured by the ASA score and the Karnofsky performance status. The extent of surgery, measured as duration of surgery, blood loss, and degree of bone resection were not associated with 30-day mortality. PMID:27082592

  19. Quantitative ultrasound spectroscopic imaging for characterization of disease extent in prostate cancer patients.

    Science.gov (United States)

    Sadeghi-Naini, Ali; Sofroni, Ervis; Papanicolau, Naum; Falou, Omar; Sugar, Linda; Morton, Gerard; Yaffe, Martin J; Nam, Robert; Sadeghian, Alireza; Kolios, Michael C; Chung, Hans T; Czarnota, Gregory J

    2015-02-01

    Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r(2) value of 0.71 (P<.0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r(2)=0.764, P<.05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.

  20. Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients1

    Science.gov (United States)

    Sadeghi-Naini, Ali; Sofroni, Ervis; Papanicolau, Naum; Falou, Omar; Sugar, Linda; Morton, Gerard; Yaffe, Martin J.; Nam, Robert; Sadeghian, Alireza; Kolios, Michael C.; Chung, Hans T.; Czarnota, Gregory J.

    2015-01-01

    Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~ 5 MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r2 value of 0.71 (P < .0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r2 = 0.764, P < .05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation. PMID:25749174

  1. Value of left ventricular ejection fraction during exercise in predicting the extent of coronary artery disease.

    Science.gov (United States)

    DePace, N L; Iskandrian, A S; Hakki, A H; Kane, S A; Segal, B L

    1983-04-01

    To determine the relation between left ventricular performance during exercise and the extent of coronary artery disease, the results of exercise radionuclide ventriculography were analyzed in 65 patients who also underwent cardiac catheterization. A scoring system was used to quantitate the extent of coronary artery disease. This system takes into account the number and site of stenoses of the major coronary vessels and their secondary branches. The conventional method of interpreting the coronary angiograms indicated that 26 patients had significant coronary artery disease (defined as 70% or more narrowing of luminal diameter) of one vessel, 21 had multivessel disease and 18 had no significant coronary artery disease. Although the exercise left ventricular ejection fraction was significantly higher in patients with no coronary artery disease than in patients with one or multivessel disease (probability [p] less than 0.001), there was considerable overlap among the three groups. With the scoring system, a good correlation was found between the coronary artery disease score and the exercise left ventricular ejection fraction (r = -0.70; p less than 0.001). If the exercise heart rate was 130 beats/min or greater or the age of the patient was 50 years or less, an even better correlation was found (r = -0.73 and r = -0.82, respectively). The exercise ejection fraction (but not the change in ejection fraction, end-diastolic volume and end-systolic volume from rest to exercise) correlated with the extent of coronary artery disease. The exercise ejection fraction is the most important exercise variable that correlates with the extent of coronary artery disease when the latter is assessed quantitatively by a scoring system rather than the conventional method of reporting coronary angiograms. Young age and greater exercise heart rate strengthened the correlation. The change in ejection fraction from rest to exercise is useful in the diagnosis of coronary artery disease

  2. Sea-ice extent provides a limited metric of model performance

    Directory of Open Access Journals (Sweden)

    D. Notz

    2013-06-01

    Full Text Available We examine the common practice of using sea-ice extent as the primary metric to evaluate modeled sea-ice coverage. Based on this analysis, we recommend a possible best practice for model evaluation. We find that for Arctic summer sea ice, model biases in sea-ice extent can be qualitatively different compared to biases in the geophysically more meaningful sea-ice area. These differences come about by a different frequency distribution of high-concentration sea-ice: while in summer about half of the CMIP5 models and satellite retrievals based on the Bootstrap and the ASI algorithm show a compact ice cover with large areas of high concentration sea ice, the other half of the CMIP5 models and satellite retrievals based on the NASA Team algorithm show a loose ice cover. The different behaviour of the CMIP5 models can be explained by their different distribution of excess heat between lateral melt and sea-ice thinning. Differences in grid geometry and round-off errors during interpolation only have a minor impact on the different biases in sea-ice extent and sea-ice area. Because of regional cancellation of biases in the integrative measures sea-ice extent and sea-ice area, these measures show little correlation with the more meaningful mean absolute bias in sea-ice concentration. Comparing the uncertainty arising directly from the satellite retrievals with those that arise from internal variability, we find that the latter by far dominates the uncertainty estimate for trends in sea-ice extent and area: much of the differences between modeled and observed trends can simply be explained by internal variability. Only for the absolute value of sea-ice area, differences between observations and models are so large that they cannot be explained by either observational uncertainty nor internal variability.

  3. [The hardness of the traumatic object and the extent of injury (as exemplified by head injuries)].

    Science.gov (United States)

    Shadymov, A B; Kazymov, M A

    2014-01-01

    The objective of the present work was to study the influence of the surface hardness of a traumatic agent on the extent and character of the injury to the soft and bone tissues of the cranial vault associated with various forms of injurious exposure. The authors evaluated forensic medical significance of the hardness as one of the most important properties of the major injurious agents involved in the formation of skull fractures and soft tissue ruptures under effect of an impact action or compression. The objects differing in the hardness of the contact element (striking pin) were studied in comparison with the hardness of the bone tissue. The extent and morphological features of the injuries to the bones and soft tissues in different parts of the skull were compared with reference to deformation and strength characteristics developing in response to a blow and compression.

  4. To what extent can isotopes help substantiate natural attenuation of chlorinated ethenes?

    DEFF Research Database (Denmark)

    Badin, A.; Broholm, Mette Martina; Hunkeler, D.

    Chlorinated ethenes are common groundwater contaminants which biodegradation into non-toxic end-products is difficult, contrary to petroleum hydrocarbons. As natural attenuation by biodegradation is a cost-effective environmental friendly remediation approach, evaluating a chlorinated ethenes plume...... degree of attenuation by biodegradation is essential. Yet, the degree to which this process is involved in concentration decrease in the field is not always straightforward as concentration can also decrease due to dilution or sorption. In the past ten years, isotopic methods have gained interest...... as they are mainly affected by biodegradation and would thus allow quantifying the extent of biodegradation regardless of any dilution process. Numerous studies demonstrated this method potential to evaluate the extent of biodegradation based on laboratory-scale studies, but few were dedicated to evaluate the degree...

  5. The extent to which core nursing textbooks inform holistic spiritual care.

    Science.gov (United States)

    Timmins, Fiona; Murphy, Maryanne; Begley, Thelma; Neill, Freda; Sheaf, Greg

    2016-09-01

    National and international professional health and nursing guidelines recommend that attention should be given to the spiritual and religious needs of patients. This suggests that spiritual care is an important aspect of holistic patient care that needs to be considered and supported, if relevant, in a healthcare context. However, many nurses lack knowledge and awareness of the subject, and it is unclear to what extent core textbooks provide the information they need. This article reports on a study that explored the extent to which contemporary core nursing textbooks support and advocate the provision of spiritual care by nurses. Its findings suggest there is a lack of consistency in the inclusion of spirituality in these texts, and few refer specifically to the need for spiritual assessment tools or referral to chaplains. As more attention is given to patients' spiritual needs, the guidance given by nursing textbooks needs to be more substantive and consistent.

  6. Efficacy of volume navigation in assessment of extent of breast cancer

    Institute of Scientific and Technical Information of China (English)

    Satoko Suzuki; Miki Mori; Rena Shigenaga; Kenya Suzuki; Katsutoshi Enokido; Terumasa Sawada; Masanori Hirose; Seigo Nakamura

    2012-01-01

    Objective Volume navigation (Vnav) combines real-time ultrasound (US) with previously acquired volume data from magnetic resonance imaging (MRI) data into a single display. The efficacy of Vnav for preoperative assessment of the extent of breast cancer lesions was evaluated in the present study.Methods Twenty-nine breast cancer patients were evaluated using Vnav during second-look US or preoperative mapping. Retrospective chart review was performed. Correlation detection rates and pathological results were evaluated.Results Vnav identified lesions that were initially detected on MRI in 23 of 29 patients (79.3%). Of the 23 patients who had US correlated lesions, pathological diagnoses of the corresponding lesions were as follows: benign (n=9) and malignant (n=14).Conclusion Vnav may be a useful technique for identification of the extent of breast cancer lesions.

  7. Enhancing Nanoparticle-Based Visible Detection by Controlling the Extent of Aggregation

    Science.gov (United States)

    Lim, Seokwon; Koo, Ok Kyung; You, Young Sang; Lee, Yeong Eun; Kim, Min-Sik; Chang, Pahn-Shick; Kang, Dong Hyun; Yu, Jae-Hyuk; Choi, Young Jin; Gunasekaran, Sundaram

    2012-06-01

    Visible indication based on the aggregation of colloidal nanoparticles (NPs) is highly advantageous for rapid on-site detection of biological entities, which even untrained persons can perform without specialized instrumentation. However, since the extent of aggregation should exceed a certain minimum threshold to produce visible change, further applications of this conventional method have been hampered by insufficient sensitivity or certain limiting characteristics of the target. Here we report a signal amplification strategy to enhance visible detection by introducing switchable linkers (SLs), which are designed to lose their function to bridge NPs in the presence of target and control the extent of aggregation. By precisely designing the system, considering the quantitative relationship between the functionalized NPs and SLs, highly sensitive and quantitative visible detection is possible. We confirmed the ultrahigh sensitivity of this method by detecting the presence of 20 fM of streptavidin and fewer than 100 CFU/mL of Escherichia coli.

  8. The Role of Deposition in Limiting the Hazard Extent of Dense-Gas Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, M B

    2008-01-29

    Accidents involving release of large (multi-ton) quantities of toxic industrial chemicals often yield far fewer fatalities and causalities than standard, widely-used assessment and emergency response models predict. While recent work has suggested that models should incorporate the protection provided by buildings, more refined health effect methodologies, and more detailed consideration of the release process; investigations into the role of deposition onto outdoor surfaces has been lacking. In this paper, we examine the conditions under which dry deposition may significantly reduce the extent of the downwind hazard zone. We provide theoretical arguments that in congested environments (e.g. suburbs, forests), deposition to vertical surfaces (such as building walls) may play a significant role in reducing the hazard zone extent--particularly under low-wind, stable atmospheric conditions which are often considered to be the worst-case scenario for these types of releases. Our analysis suggests that in these urban or suburban environments, the amount of toxic chemicals lost to earth's surface is typically a small fraction of overall depositional losses. For isothermal gases such as chlorine, the degree to which the chemicals stick to (or react with) surfaces (i.e. surface resistance) is demonstrated to be a key parameter controlling hazard extent (the maximum distance from the release at which hazards to human health are expected). This analysis does not consider the depositional effects associated with particulate matter or gases that undergo significant thermal change in the atmosphere. While no controlled experiments were available to validate our hypothesis, our analysis results are qualitatively consistent with the observed downwind extent of vegetation damage in two chlorine accidents.

  9. Comparison of Bioclimatic, NDVI and Elevation variables in assessing extent of Commiphora wightii (Arnt.) Bhand.

    Science.gov (United States)

    Kulloli, R. N.; Kumar, S.

    2014-11-01

    Commiphora wightii (Arnt.) Bhand., is an important medicinal plant of Indian Medicine System (IMS) since ancient time. It is used in different ailments of obesity, arthritis, rheumatism and high cholesterol. Due to overexploitation its natural populations declined to large extent. IUCN has put it under Data Deficient (DD) category due to lack of data on its extent of occurrence in nature. Hence, the study was carried out using MaxEnt distribution modelling algorithm to estimate its geographic distribution and to identify potential habitats for its reintroduction. For modelling employed 68 presence locality data, 19 bioclimatic variables, Normalize Difference Vegetation Index (NDVI) and elevation data. These were tested for multicollinearity and those variables having r-value less than 0.8 were selected for further analysis, which was carried out in two ways i) Bioclimatic variables and elevation; ii) NDVI and elevation. Area Under the Curve (AUC) in both analysis was above 0.9 for all variables, indicating very high accuracy of prediction. Variables governing distribution of C. wightii in the analysis using bioclimatic and elevation data set are precipitation seasonality (56.6 %), annual precipitation (16.4 %) and elevation (14.7 %). Extent of occurrence of C.wightii predicted by model closely matched in the districts of Jaisalmer and Barmer. In the second analysis elevation (48.3 %), NDVI of June (11.1 %) and August (11.2 %) contributed for NDVI and Elevation data set. NDVI of June corresponds to its leafing phase while NDVI of August to flowering phase. Area of its occurrence predicted for NDVI and elevation data set are Bikaner, Churu, Jhunjhunun some part of Jodhpur which are completely sandy, where C. wightii is totally absent. Extent of occurrence was also validated in ground survey. Potential areas for its reintroduction were identified as Jaisalmer and Barmer districts in Indian arid zone.

  10. Decreased plasma urotensin Ⅱ levels inversely correlate with extent and severity of coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To determine the plasma urolensin Ⅱ(UⅡ) levels in various types of coronary heart disease and to clarify how the plasma UⅡ levels correlate with the clinical presentation, extent and severity of coronary artery atherosclerosis (CAD). Methods: One hundred and three aged patients undergoing elective diagnostic coronary angiography for proven or clinical suspected coronary heart disease were enrolled in this study. The extent and severity of coronary artery disease were evaluated by vessel score and Gensini score, respectively. Plasma UⅡ levels were measured by radioimmunoassay. Results: The plasma UⅡ levels in the patients with modest to severe coronary stenosis (3.03±0.34 pg/ml, 1.83±0.67 pg/ml) were significantly lower than that in subjects with normal coronary artery (4.80±1.11 pg/ml, P<0.001). The plasma UⅡ levels in patients with coronary heart disease were also significantly lower than that in patients with insignificant coronary stenosis (P < 0.001). Compared to patients with stable angina pectoris, plasma UⅡ levels in patients with acute coronary syndrome were significantly decreased (1.89±0.51 pg/ml vs 2.42±0.77 pg/ml, P< 0.001). Plasma UⅡ levels were found to be negatively correlated with the severity of coronary artery stenosis (r = -0.488, P<0.001), as well as the vessel score (r = -0.408, P<0.05) in the patients with CAD. Conclusion: Significant inverse correlations exist between the plasma UⅡ levels, and the extent and severity of coronary artery stenosis. These findings suggest that plasma UⅡ contribute to the development and progression of coronary artery stenosis, and may be a novel marker to predict clinical types, as well as the extent and severity of coronary artery disease in the patients.

  11. Genetic dissection of the Canq1 locus governing variation in extent of the collateral circulation.

    Directory of Open Access Journals (Sweden)

    Shiliang Wang

    Full Text Available BACKGROUND: Native (pre-existing collaterals are arteriole-to-arteriole anastomoses that interconnect adjacent arterial trees and serve as endogenous bypass vessels that limit tissue injury in ischemic stroke, myocardial infarction, coronary and peripheral artery disease. Their extent (number and diameter varies widely among mouse strains and healthy humans. We previously identified a major quantitative trait locus on chromosome 7 (Canq1, LOD = 29 responsible for 37% of the heritable variation in collateral extent between C57BL/6 and BALB/c mice. We sought to identify candidate genes in Canq1 responsible for collateral variation in the cerebral pial circulation, a tissue whose strain-dependent variation is shared by similar variation in other tissues. METHODS AND FINDINGS: Collateral extent was intermediate in a recombinant inbred line that splits Canq1 between the C57BL/6 and BALB/c strains. Phenotyping and SNP-mapping of an expanded panel of twenty-one informative inbred strains narrowed the Canq1 locus, and genome-wide linkage analysis of a SWRxSJL-F2 cross confirmed its haplotype structure. Collateral extent, infarct volume after cerebral artery occlusion, bleeding time, and re-bleeding time did not differ in knockout mice for two vascular-related genes located in Canq1, IL4ra and Itgal. Transcript abundance of 6 out of 116 genes within the 95% confidence interval of Canq1 were differentially expressed >2-fold (p-value<0.05÷150 in the cortical pia mater from C57BL/6 and BALB/c embryos at E14.5, E16.5 and E18.5 time-points that span the period of collateral formation. CONCLUSIONS: These findings refine the Canq1 locus and identify several genes as high-priority candidates important in specifying native collateral formation and its wide variation.

  12. Improving the extent of malignant glioma resection by dual intraoperative visualization approach.

    Directory of Open Access Journals (Sweden)

    Ilker Y Eyüpoglu

    Full Text Available Despite continuing debates around cytoreductive surgery in malignant gliomas, there is broad consensus that increased extent of tumor reduction improves overall survival. However, maximization of the extent of tumor resection is hampered by difficulty in intraoperative discrimination between normal and pathological tissue. In this context, two established methods for tumor visualization, fluorescence guided surgery with 5-ALA and intraoperative MRI (iMRI with integrated functional neuronavigation were investigated as a dual intraoperative visualization (DIV approach. Thirty seven patients presumably suffering from malignant gliomas (WHO grade III or IV according to radiological appearance were included. Twenty-one experimental sequences showing complete resection according to the 5-ALA technique were confirmed by iMRI. Fourteen sequences showing complete resection according to the 5-ALA technique could not be confirmed by iMRI, which detected residual tumor. Further analysis revealed that these sequences could be classified as functional grade II tumors (adjacent to eloquent brain areas. The combination of fluorescence guided resection and intraoperative evaluation by high field MRI significantly increased the extent of tumor resection in this subgroup of malignant gliomas located adjacent to eloquent areas from 61.7% to 100%; 5-ALA alone proved to be insufficient in attaining gross total resection without the danger of incurring postoperative neurological deterioration. Furthermore, in the case of functional grade III gliomas, iMRI in combination with functional neuronavigation was significantly superior to the 5-ALA resection technique. The extent of resection could be increased from 57.1% to 71.2% without incurring postoperative neurological deficits.

  13. Atrial Fibrillation in Hypertrophic Cardiomyopathy: Is the Extent of Septal Hypertrophy Important?

    Science.gov (United States)

    Park, Kyoung-Min; Im, Sung Il; Kim, Eun Kyoung; Lee, Sang-Chol; Park, Seung-Jung; Kim, June Soo; On, Young Keun

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is a cardiac disease associated with a high incidence of atrial fibrillation (AF). Recent studies have suggested that interventricular septum thickness may influence the risk stratification of patients with AF. We evaluated the effects of septal hypertrophy on morbidity and mortality in patients with HCM. Patients were followed for a median of 6.1 years and were divided into two groups according to the extent of septal hypertrophy. A total of 1,360 HCM patients were enrolled: 482 (33%) apical or apicoseptal, 415 (28%) asymmetric septal, 388 (27%) basal septal, 38 (2.6%) concentric, and 37 (2.5%) diffuse and mixed type. Ninety-two all-cause deaths and 21 cardiac deaths occurred. The total event rates were significantly higher for patients with HCM with more extensive septal hypertrophy (group A) compared to those with HCM ± focal septal hypertrophy (group B), regardless of type (p<0.001). Arrhythmias occurred in 502 patients, with a significantly higher incidence in group A than in group B (p<0.001). Among patients with arrhythmias, the incidence of AF was significantly higher in group A than group B (p<0.001). In univariate Cox analysis, a greater extent of septal hypertrophy (p<0.001), E/E´ ratio (p = 0.011), and mitral regurgitation grade (p = 0.003) were significantly associated with developing AF. In multivariate Cox analyses, a greater extent of septal hypertrophy [odds ratio (OR) 5.44 (2.29-12.92), p<0.001] in patients with HCM was significantly associated with developing AF. In conclusion, a greater extent of septal hypertrophy is an independent predictor of progression to AF in patients with HCM.

  14. Status of wetlands in India: A review of extent, ecosystem benefits, threats and management strategies

    OpenAIRE

    Nitin Bassi; M. DINESH KUMAR; Anuradha Sharma; Pardha-Saradhi, P.

    2014-01-01

    Study region: India. Study focus: India has a wealth of wetland ecosystems that support diverse and unique habitats. These wetlands provide numerous ecological goods and services but are under tremendous stress due to rapid urbanization, industrialization and agricultural intensification, manifested by the shrinkage in their areal extent, and decline in the hydrological, economic and ecological functions they perform. This paper reviews the wetland wealth of India in terms of their geograp...

  15. Testing models of ice cap extent, South Georgia, sub-Antarctic

    OpenAIRE

    Barlow, NLM; Bentley, MJ; G. Spada; Evans, DJA; Hansom, JD; Brader, MD; White, DA; Zander, A; Berg, S.

    2016-01-01

    The extent of Last Glacial Maximum ice in South Georgia is contested, with two alternative hypotheses: an extensive (maximum) model of ice reaching the edge of the continental shelf, or a restricted (minimum) model with ice constrained within the inner fjords. We present a new relative sea-level dataset for South Georgia, summarising published and new geomorphological evidence for the marine limit and elevations of former sea levels on the island. Using a glacial isostatic adjustment model (A...

  16. Testing models of ice cap extents, South Georgia, sub-Antarctic

    OpenAIRE

    N. L. M. Barlow; Bentley, M.J.; G. Spada; Evans, D.J.A.; Hansom, J.D.; Brader, M.D.; White, D. A.; Zander, A; Berg, S.

    2016-01-01

    The extent of Last Glacial Maximum ice in South Georgia is\\ud contested, with two alternative hypotheses: an extensive (maximum) model ofice reaching the edge of the continental shelf, or a restricted(minimum) model with ice constrained within the inner fjords. We present new relative sea-level dataset for South Georgia, summarising published\\ud and new geomorphological evidence for the marine limit and elevations offormer sea levels on the island. Using a glacial isostatic adjustmentmodel (A...

  17. Extent of linkage disequilibrium in the domestic cat, Felis silvestris catus, and its breeds.

    Directory of Open Access Journals (Sweden)

    Hasan Alhaddad

    Full Text Available Domestic cats have a unique breeding history and can be used as models for human hereditary and infectious diseases. In the current era of genome-wide association studies, insights regarding linkage disequilibrium (LD are essential for efficient association studies. The objective of this study is to investigate the extent of LD in the domestic cat, Felis silvestris catus, particularly within its breeds. A custom illumina GoldenGate Assay consisting of 1536 single nucleotide polymorphisms (SNPs equally divided over ten 1 Mb chromosomal regions was developed, and genotyped across 18 globally recognized cat breeds and two distinct random bred populations. The pair-wise LD descriptive measure (r(2 was calculated between the SNPs in each region and within each population independently. LD decay was estimated by determining the non-linear least-squares of all pair-wise estimates as a function of distance using established models. The point of 50% decay of r(2 was used to compare the extent of LD between breeds. The longest extent of LD was observed in the Burmese breed, where the distance at which r(2 ≈ 0.25 was ∼380 kb, comparable to several horse and dog breeds. The shortest extent of LD was found in the Siberian breed, with an r(2 ≈ 0.25 at approximately 17 kb, comparable to random bred cats and human populations. A comprehensive haplotype analysis was also conducted. The haplotype structure of each region within each breed mirrored the LD estimates. The LD of cat breeds largely reflects the breeds' population history and breeding strategies. Understanding LD in diverse populations will contribute to an efficient use of the newly developed SNP array for the cat in the design of genome-wide association studies, as well as to the interpretation of results for the fine mapping of disease and phenotypic traits.

  18. Capturing heterogeneity: The role of a study area's extent for estimating net precipitation

    Science.gov (United States)

    Zimmermann, Alexander; Voss, Sebastian; Metzger, Johanna Clara; Hildebrandt, Anke; Zimmermann, Beate

    2016-04-01

    Accurate and precise estimates of net precipitation are required for many hydrological applications. For instance, most interception models require high quality estimates of the canopy storage capacity and the free throughfall coefficient. Good estimates of these parameters, in turn, critically depend on the quality of throughfall estimates. Previous attempts to guide throughfall sampling focused on the selection of an appropriate sample size, support, and sampling design. Comparatively little attention has been given to the role of the extent, i.e. the size of the area under study. In this contribution we investigate the influence of the extent on the representativeness of mean throughfall estimates for simply structured and heterogeneous forest ecosystems. We based our investigation on stochastic simulations which we derived from large empirical throughfall datasets. Using the simulated throughfall fields, we conducted virtual sampling experiments using a number of typical extents. We ran these tests both for a range of event sizes and for accumulated data. Our findings suggest that the size of the study area should be carefully adapted to the required temporal resolution of the throughfall data (i.e. event-based versus long-term) and to the complexity of the system under study.

  19. A field test of the extent of bias in selection estimates after accounting for emigration

    Science.gov (United States)

    Letcher, B.H.; Horton, G.E.; Dubreuil, T.L.; O'Donnell, M. J.

    2005-01-01

    Question: To what extent does trait-dependent emigration bias selection estimates in a natural system? Organisms: Two freshwater cohorts of Atlantic salmon (Salmo salar) juveniles. Field site: A 1 km stretch of a small stream (West Brook) in western Massachusetts. USA from which emigration could be detected continuously. Methods: Estimated viability selection differentials for body size either including or ignoring emigration (include = emigrants survived interval, ignore = emigrants did not survive interval) for 12 intervals. Results: Seasonally variable size-related emigration from our study site generated variable levels of bias in selection estimates for body size. The magnitude of this bias was closely related with the extent of size-dependent emigration during each interval. Including or ignoring the effects of emigration changed the significance of selection estimates in 5 of the 12 intervals, and changed the estimated direction of selection in 4 of the 12 intervals. These results indicate the extent to which inferences about selection in a natural system can be biased by failing to account for trait-dependent emigration. ?? 2005 Benjamin H. Letcher.

  20. The Role of Deposition in Limiting the Hazard Extent of Dense-Gas Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, M B

    2008-05-11

    Accidents that involve large (multi-ton) releases of toxic industrial chemicals and form dense-gas clouds often yield far fewer fatalities, casualties and environmental effects than standard assessment and emergency response models predict. This modeling study, which considers both dense-gas turbulence suppression and deposition to environmental objects (e.g. buildings), demonstrates that dry deposition to environmental objects may play a significant role in reducing the distance at which adverse impacts occur - particularly under low-wind, stable atmospheric conditions which are often considered to be the worst-case scenario for these types of releases. The degree to which the released chemical sticks to (or reacts with) environmental surfaces is likely a key parameter controlling hazard extents. In all modeled cases, the deposition to vertical surfaces of environmental objects (e.g. building walls) was more efficient in reducing atmospheric chemical concentrations than deposition to the earth's surface. This study suggests that (1) hazard extents may vary widely by release environment (e.g. grasslands vs. suburbia) and release conditions (e.g. sunlight or humidity may change the rate at which chemicals react with a surface) and (2) greenbelts (or similar structures) may dramatically reduce the impacts of large-scale releases. While these results are demonstrated to be qualitatively consistent with the downwind extent of vegetation damage in two chlorine releases, critical knowledge gaps exist and this study provides recommendations for additional experimental studies.

  1. Relationship between Hadley circulation and sea ice extent in the Bering Sea

    Institute of Scientific and Technical Information of China (English)

    ZHOU BoTao; WANG HuiJun

    2008-01-01

    The linkage between Hadley circulation (HC) and sea ice extent in the Bering Sea during March-April is investigated through an analysis of observed data in this research. It is found that HC is negatively correlated to the sea ice extent in the Bering Sea, namely, strong (weak) HC is corresponding to less (more) sea ice in the Bering Sea. The present study also addresses the large-scale atmospheric general circulation changes underlying the relationship between HC and sea ice in the Bering Sea. It follows that a positive phase of HC corresponds to westward located Aleutian low, anomalous southerlies over the eastern North Pacific and higher temperature in the Bering Sea, providing unfavorable atmospheric and thermal conditions for the sea ice forming, and thus sea ice extent in the Bering Sea is decreased, and vice versa. In addition, it is further identified that East Asian-North Pacific-North America telecon-nection may play an important role in linking HC and changes of atmospheric circulations as well as sea ice in the Bering Sea.

  2. Impact of the El Nino on the Variability of the Antarctic Sea Ice Extent

    Institute of Scientific and Technical Information of China (English)

    陈锦年; 褚健婷; 徐兰英

    2004-01-01

    In this paper, the spreading way in the southern hemisphere that anomalous warm water piled in tropical eastern Pacific is analysed and then impact of El Nino on the variability of the Antarctic sea ice extent is investigated by using a dataset from 1970 to 2002. The analysis result show that in El Nino event the anomalous warm water piled in tropical eastern Pacific is poleward propagation yet the westward propagation along southern equator current hasn 't been discovered . The poleward propagation time of the anomalous warm water is about 1 year or so. El Nino event has a close relationship with the sea ice extent in the Amundsen sea , Bellingshausen sea and Antarctic peninsula. After El Nino appears , there is a lag of two years that the sea ice in the Amundsen sea , Bellingshausea sea, especially in the Antarctic peninsula decreases obviously. The processes that El Nino has influence with Antarctic sea ice extent is the warm water piled in tropical eastern Pacific poleward propagation along off the coast of southern America and cause the anomalous temperature raise in near pole and then lead the sea ice in Amundsen sea , Bellingshausen sea and Antarctic peninsula to decrease where the obvious decrease of the sea ice since 80 'decade has close relation to the frequently appearance of El Nino.

  3. A global dataset of the extent of irrigated land from 1900 to 2005

    Directory of Open Access Journals (Sweden)

    S. Siebert

    2014-12-01

    Full Text Available Irrigation intensifies land use by increasing crop yield but also impacts water resources. It affects water and energy balances and consequently the microclimate in irrigated regions. Therefore, knowledge of the extent of irrigated land is important for hydrological and crop modelling, global change research, and assessments of resource use and management. Information on the historical evolution of irrigated lands is limited. The new global Historical Irrigation Dataset (HID provides estimates of the temporal development of the area equipped for irrigation (AEI between 1900 and 2005 at 5 arc-minute resolution. We collected subnational irrigation statistics from various sources and found that the global extent of AEI increased from 63 million ha (Mha in 1900 to 112 Mha in 1950 and 306 Mha in 2005. We developed eight gridded versions of time series of AEI by combining subnational irrigation statistics with different data sets on the historical extent of cropland and pasture. Different rules were applied to maximize consistency of the gridded products to subnational irrigation statistics or to historical cropland and pasture data sets. The HID reflects very well the spatial patterns of irrigated land in the western United States as shown on historical maps. Mean aridity on irrigated land increased and river discharge decreased from 1900–1950 whereas aridity decreased from 1950–2005. The dataset and its documentation are made available in an open data repository at https://mygeohub.org/publications/8 (doi:10.13019/M2MW2G.

  4. Mapping the lateral extent of human cadaver decomposition with soil chemistry.

    Science.gov (United States)

    Aitkenhead-Peterson, J A; Owings, C G; Alexander, M B; Larison, N; Bytheway, J A

    2012-03-10

    Soil below decomposing cadavers may have a different lateral spatial extent depending upon whether scavengers have access to the human cadaver or not. We examined the lateral spatial extent of decomposition products to a depth of 7cm of soils beneath two decomposing corpses, one in which the subject was autopsied, unclothed and placed under a wire cage to restrict scavenger access and one in which the subject was not autopsied, unclothed and exposed to scavengers. The two bodies had accumulated degree days (ADD) of 5799 and 5469 and post mortem interval (PMI) of 288 and 248d, respectively. The spatial extent for dissolved organic carbon (DOC) and organic nitrogen (DON) for both bodies was large but similar suggesting some movement off site for both compounds. Mean DOC was 1087±727 and 1484±1236μgg(-1) dry soil under the two corpses relative to 150±68μgg(-1) in upslope control soils. Sulfate tended to have 'hot spots' of lower values relative to the control soils indicative of anaerobic respiration. pH was lower and electrical conductivity was higher in the soil under both decomposing cadavers relative to control soils. Some of the nutrients examined downslope of the human remains were significantly higher than control soils upslope suggesting movement of decomposition products off-site which could be an important factor when using human remains detector dogs.

  5. Residual ultimate strength of a very large crude carrier considering probabilistic damage extents

    Directory of Open Access Journals (Sweden)

    Choung Joonmo

    2014-03-01

    Full Text Available This paper provides the prediction of ultimate longitudinal strengths of the hull girders of a very large crude carrier considering probabilistic damage extent due to collision and grounding accidents based on IMO Guidelines (2003. The probabilistic density functions of damage extent are expressed as a function of non-dimensional damage variables. The accumulated probabilistic levels of 10%, 30%, 50%, and 70% are taken into account for the estimation of damage extent. The ultimate strengths have been calculated using the in-house software called Ultimate Moment Analysis of Damaged Ships which is based on the progressive collapse method, with a new convergence criterion of force vector equilibrium. Damage indices are provided for several probable heeling angles from 0° (sagging to 180° (hogging due to collision- and grounding-induced structural failures and consequent flooding of compartments. This paper proves from the residual strength analyses that the second moment of area of a damage section can be a reliable index for the estimation of the residual ultimate strength. A simple polynomial formula is also proposed based on minimum residual ultimate strengths.

  6. Flood Extent Mapping for Namibia Using Change Detection and Thresholding with SAR

    Science.gov (United States)

    Long, Stephanie; Fatoyinbo, Temilola E.; Policelli, Frederick

    2014-01-01

    A new method for flood detection change detection and thresholding (CDAT) was used with synthetic aperture radar (SAR) imagery to delineate the extent of flooding for the Chobe floodplain in the Caprivi region of Namibia. This region experiences annual seasonal flooding and has seen a recent renewal of severe flooding after a long dry period in the 1990s. Flooding in this area has caused loss of life and livelihoods for the surrounding communities and has caught the attention of disaster relief agencies. There is a need for flood extent mapping techniques that can be used to process images quickly, providing near real-time flooding information to relief agencies. ENVISAT/ASAR and Radarsat-2 images were acquired for several flooding seasons from February 2008 to March 2013. The CDAT method was used to determine flooding from these images and includes the use of image subtraction, decision based classification with threshold values, and segmentation of SAR images. The total extent of flooding determined for 2009, 2011 and 2012 was about 542 km2, 720 km2, and 673 km2 respectively. Pixels determined to be flooded in vegetation were typically flooding in vegetation was much greater (almost one third of the total flooded area). The time to maximum flooding for the 2013 flood season was determined to be about 27 days. Landsat water classification was used to compare the results from the new CDAT with SAR method; the results show good spatial agreement with Landsat scenes.

  7. 周向重叠三分螺旋折流板换热器性能比较%Performance comparison of circumferential overlap trisection helical baffle heat exchanger

    Institute of Scientific and Technical Information of China (English)

    董聪; 陈亚平; 吴嘉峰; 操瑞兵

    2013-01-01

    Numerical simulation of flow and heat transfer performances were conducted in respect for four helical baffle heat exchangers with identical equilateral triangle tube layout and approximate spiral pitch but different baffle shapes and assembly configurations,i.e.,a trisection circumferential overlap baffle scheme with the baffle incline angle of 20° (20°TCO),a quadrant circumferential overlap baffle scheme with the baffle incline angle of 18° (18°QCO),a quadrant end-to-end baffle scheme with the baffle incline angle of 18° (18°QEE),and a continuous helical baffle scheme with the baffle helix angle of 18.4° (18.4°CH).The velocity-vector superimposed pressure or velocity nephograms meridian slices and the unfolded concentric hexagonal slices and the curves of local average heat fluxes on nine heat transfer tubes within a 60° sector region and on the four concentric heat transfer tube layers were presented.The results show that each baffle chamber contains secondary flow and there exists reverse leakage at the V-notch region,but the leakage of 20°TCO scheme is the least of the four schemes.Among the four schemes,the 20°TCO scheme has the highest shell-side heat transfer factor jo,friction coefficient fo and average comprehensive index (jo/fo) ; the 18°QCO scheme has the second highest values of both shell-side heat transfer factor joand friction coefficient fo; although,the 18.4°CH scheme has the lowest shell-side friction coefficient fo,its shell-side heat transfer factor jo and average comprehensive index (jo/fo) are the lowest.%对采用正三角形布管且螺距相同的4种螺旋折流板换热器方案,即倾斜角为20°三分周向重叠(20°TCO)、倾斜角为18°四分周向重叠(18°QCO)、倾斜角为18°首尾相连(18°QEE)以及螺旋角为18.4°的连续(18.4°CH)螺旋折流板换热器的流动和传热性能进行数值模拟.给出了子午切面、同心正六边形切面上速度矢量叠加压力或速度云图分布以及60

  8. 颈动脉圆周应变在心血管危险分层中的临床应用价值%Clinical application value of carotid circumferential strain in cardiovascular risk stratification

    Institute of Scientific and Technical Information of China (English)

    黄锡藩; 谭志伟; 刘彩娟; 梁可建; 严家兴

    2015-01-01

    目的:采用超声二维斑点追踪手段对不存在颈动脉粥样硬化斑块的患者进行颈动脉整体圆周应变检测,分析其颈动脉弹性,评价颈动脉圆周应变应用于心血管危险分层工作中的作用。方法:选取88例心内科住院患者,按照 Framingham 危险评分(FRS)将其划分为低危组、中危组以及高危组。对所有患者的颈总动脉收缩期峰值 CS 以及颈动脉内中膜厚度 IMT 进行测量,针对 CS 给予脉压差校正处理(CS/ PP),分析 CS、CS/ PP 以及 IMT 之间的关系。结果:CS、CS/ PP 以及 IMT 三者在低危组和中危组患者中的比较差异明显,在低危组以及高危组间比较差异显著,具有统计学意义( P ﹤0.05);CS/ PP 在三组患者间比较差异明显,具有统计学意义(P ﹤0.05)。结论:采用超声二维斑点追踪技术能够实现对颈动脉弹性情况的有效反映,利用 IMT 以及CS 能够针对患者颈动脉硬化进行结构评价以及功能评估,预测冠状动脉具体病变情况。%Objective Carotid global circumferential strain detection was conducted on the patients without carotid atherosclerotic plaque by using two - dimensional ultrasound speckle tracking methods to analyze the carotid elasticity and evaluate roles of the carotid circumferen-tial strain in the cardiovascular risk stratification. Method Eighty eight cases of the hospitalized patients in the department of cardiology of our hospital were randomly selected. According to the Framingham risk score(FRS),they were divided into low risk group,medium risk group and high risk group. Carotidartery peak systolic(CS)and intima - media thickness(IMT)of all the patients were measured. Based on CS,correc-tion and treatment of pulse pressure difference was given to analyze the relationship between CS,CS/ PP and IMT. Results There were obvious differences of CS,CS/ PP and IMT between the low risk group and the medium risk group

  9. Research on Ultrasonic Flexible Phased Array Technology for Circumferential Testing of Ultra-high Pressure Crystal Kettle%超高压水晶釜周向检测超声柔性相控阵技术研究

    Institute of Scientific and Technical Information of China (English)

    钟海见; 郭伟灿; 凌张伟

    2016-01-01

    针对内外径之比通常小于0.6的超高压水晶釜超声检测技术,常规的周向超声检测技术存在灵敏度低、缺陷定位困难等技术难点,同时国内外还没有相应的检测标准和成熟的检测工艺。相对于常规超声技术,相控阵技术可以在不更换探头的情况下,实现整个检测区域多角度、多方向扫查和动态聚焦检测,并结合实时成像技术,直观地显示缺陷的位置、分布、尺寸等信息。在试验研究的基础上,提出超高压水晶釜周向超声柔性相控阵检测技术,提出的柔性探头可以良好匹配超高压水晶釜圆柱表面,根据曲面形状设计聚焦法则,可以有效解决超高压水晶釜周向超声检测的技术难题。试验结果表明,柔性相控阵技术对超高压水晶釜的表面和内部缺陷均具有较高的检测精度和可靠性。%For the ultra-high pressure crystal kettle with the ratio of inner radius to outer radius less than 0.6,the conventional circumferential ultrasonic testing could not receive satisfied performance,because of the low sensitivity,locating defects difficultly.Comparing to conventional ultrasonic testing,ultrasonic phased array technology could realized the multi-angle,multi-direction scanning and dynamic focusing de-tection in the entire detecting region without replacement of probe and can visually display the location, distribution,size of defects utilizing the real time imaging technology.Based on the experimental study,the circumferential ultrasonic phased array technique is proposed for ultra-high pressure crystal kettle.A flexi-ble probe is designed which can be good match to the surface of ultra-high pressure crystal kettle.The fo-cal law is designed based on the curved shape and can effective excite the probe.The experimental result show that the flexible phased array technology proposed in this paper has high detection precision and re-liability for the detection of

  10. 周向长弧形弹簧双质量飞轮静刚度理论模型研究%Study on Static Stiffness Model of Long Circumferential Spring Dual Mass Flywheel

    Institute of Scientific and Technical Information of China (English)

    胡伟; 江征风; 曾荣; 陈雷; 王立伟

    2014-01-01

    The static stiffness model of circumferential arc spring dual mass flywheel (DMF-CS) was established based on the feature of changeable helix angle of arc spring.Based on the theoretical equations of the spring curve,according to periodical changing characteristics of the helix angle,the relation between transferred torque and total deformation of the arc spring was figured out using relat-ed mechanics theory.Applying the static stiffness test bench of DMF-CS,the experimental study was carried out.The theoretical and experimental results were compared,which validated the feasibility and accuracy of the established model.Meanwhile,the established model was compared with other theoretical models,which show that this model improves the precision of the static stiffness calcula-tion.%以弧形弹簧自身变螺旋角的特征为基础建立了周向长弧形弹簧双质量飞轮静刚度理论模型。基于弧形弹簧曲线方程,根据弧形弹簧螺旋角成周期变化的特点,结合相关力学理论推导出弧形弹簧传递扭矩与总变形之间的关系(弹簧静刚度)。应用周向长弧形弹簧双质量飞轮静刚度实验台进行了试验研究,试验结果与理论结果的对比验证了该静刚度理论模型的可行性与准确性;对比多种其他静刚度理论模型,该方法提高了静刚度计算精度。

  11. THE USE OF LIDAR AND VOLUNTEERED GEOGRAPHIC INFORMATION TO MAP FLOOD EXTENTS AND INUNDATION

    Directory of Open Access Journals (Sweden)

    K. McDougall

    2012-07-01

    Full Text Available Floods are one of the most destructive natural disasters that threaten communities and properties. In recent decades, flooding has claimed more lives, destroyed more houses and ruined more agricultural land than any other natural hazard. The accurate prediction of the areas of inundation from flooding is critical to saving lives and property, but relies heavily on accurate digital elevation and hydrologic models. The 2011 Brisbane floods provided a unique opportunity to capture high resolution digital aerial imagery as the floods neared their peak, allowing the capture of areas of inundation over the various city suburbs. This high quality imagery, together with accurate LiDAR data over the area and publically available volunteered geographic imagery through repositories such as Flickr, enabled the reconstruction of flood extents and the assessment of both area and depth of inundation for the assessment of damage. In this study, approximately 20 images of flood damaged properties were utilised to identify the peak of the flood. Accurate position and height values were determined through the use of RTK GPS and conventional survey methods. This information was then utilised in conjunction with river gauge information to generate a digital flood surface. The LiDAR generated DEM was then intersected with the flood surface to reconstruct the area of inundation. The model determined areas of inundation were then compared to the mapped flood extent from the high resolution digital imagery to assess the accuracy of the process. The paper concludes that accurate flood extent prediction or mapping is possible through this method, although its accuracy is dependent on the number and location of sampled points. The utilisation of LiDAR generated DEMs and DSMs can also provide an excellent mechanism to estimate depths of inundation and hence flood damage

  12. These lit areas are undeveloped: Delimiting China's urban extents from thresholded nighttime light imagery

    Science.gov (United States)

    Liu, Ying; Delahunty, Tina; Zhao, Naizhuo; Cao, Guofeng

    2016-08-01

    Nighttime light imagery is a powerful tool to study urbanization because it can provide a uniform metric, lit area, to delimit urban extents. However, lit area is much larger than actual urban area, so thresholds of digital number (DN) values are usually needed to reduce the lit area. The threshold varies greatly among different regions, but at present it is still not very clear what factors impact the changes of the threshold. In this study, urban extent by province for China is mapped using official statistical data and four intercalibrated and geometrically corrected nighttime light images between 2004 and 2010. Lit area in the imagery for most provinces is at least 94% greater than the official amount of urban area. Regression analyses show a significant correlation between optimal thresholds and GDP per capita, and larger thresholds more commonly indicate higher economic level. Size and environmental condition may explain a province's threshold that is disproportionate to GDP. Findings indicate one threshold DN is not appropriate for multiple (adjacent) province urban extent mapping, and optimal thresholds for one year may be notably different than the next. Province-level derived thresholds are not appropriate for other geographic levels. Brightness of nighttime lights is an advantage over imagery that relies on daylight reflection, and decreases in brightness indicate faster growth in the horizontal direction than the vertical. A province's optimal threshold does not always maintain an increase with population and economic growth. In the economically developed eastern provinces, urban population densities decreased (and this is seen in the brightness data), while urban population increased.

  13. Observed sea ice extent in the Russian Arctic, 1933-2006

    Science.gov (United States)

    Mahoney, Andrew R.; Barry, Roger G.; Smolyanitsky, Vasily; Fetterer, Florence

    2008-11-01

    We present a time series of sea ice extent in the Russian Arctic based on observational sea ice charts compiled by the Arctic and Antarctic Research Institute (AARI). These charts are perhaps the oldest operational sea ice data in existence and show that sea ice extent in the Russian Arctic has generally decreased since the beginning of the chart series in 1933. This retreat has not been continuous, however. For the Russian Arctic as a whole in summer, there have been two periods of retreat separated by a partial recovery between the mid-1950s and mid-1980s. The AARI charts, combined with air temperature records, suggest that the retreat in recent decades is pan-Arctic and year-round in some regions, whereas the early twentieth century retreat was only observed in summer in the Russian Arctic. The AARI ice charts indicate that a significant transition occurred in the Russian Arctic in the mid-1980s, when its sea ice cover began to retreat along with that of the rest of the Arctic. Summertime sea ice extents derived from the AARI data set agree with those derived from passive microwave, including the Hadley Centre's global sea ice coverage and sea surface temperature (HadISST) data set. The HadISST results do not indicate the 1980s transition or the partial recovery that took place before it. The AARI charts therefore add significantly to our understanding of the variability of Arctic sea ice over the last 8 decades, and we recommend their inclusion in future historical data sets of Arctic sea ice.

  14. Differentiating the extent of cartilage repair in rabbit ears using nonlinear optical microscopy.

    Science.gov (United States)

    Zhu, X Q; Xu, Y H; Liao, C X; Liu, W G; Cheng, K K; Chen, J X

    2015-11-01

    Nonlinear optical microscopy (NLOM) was used as a noninvasive and label-free tool to detect and quantify the extent of the cartilage recovery. Two cartilage injury models were established in the outer ears of rabbits that created a different extent of cartilage recovery based on the presence or absence of the perichondrium. High-resolution NLOM images were used to measure cartilage repair, specifically through spectral analysis and image texture. In contrast to a wound lacking a perichondrium, wounds with intact perichondria demonstrated significantly larger TPEF signals from cells and matrix, coarser texture indicating the more deposition of type I collagen. Spectral analysis of cells and matrix can reveal the matrix properties and cell growth. In addition, texture analysis of NLOM images showed significant differences in the distribution of cells and matrix of repaired tissues with or without perichondrium. Specifically, the decay length of autocorrelation coefficient based on TPEF images is 11.2 ± 1.1 in Wound 2 (with perichondrium) and 7.5 ± 2.0 in Wound 1 (without perichondrium), indicating coarser image texture and faster growth of cells in repaired tissues with perichondrium (p < 0.05). Moreover, the decay length of autocorrelation coefficient based on collagen SHG images also showed significant difference between Wound 2 and 1 (16.2 ± 1.2 vs. 12.2 ± 2.1, p < 0.05), indicating coarser image texture and faster deposition of collagen in repaired tissues with perichondrium (Wound 2). These findings suggest that NLOM is an ideal tool for studying cartilage repair, with potential applications in clinical medicine. NLOM can capture macromolecular details and distinguish between different extents of cartilage repair without the need for labelling agents.

  15. The Use of LIDAR and Volunteered Geographic Information to Map Flood Extents and Inundation

    Science.gov (United States)

    McDougall, K.; Temple-Watts, P.

    2012-07-01

    Floods are one of the most destructive natural disasters that threaten communities and properties. In recent decades, flooding has claimed more lives, destroyed more houses and ruined more agricultural land than any other natural hazard. The accurate prediction of the areas of inundation from flooding is critical to saving lives and property, but relies heavily on accurate digital elevation and hydrologic models. The 2011 Brisbane floods provided a unique opportunity to capture high resolution digital aerial imagery as the floods neared their peak, allowing the capture of areas of inundation over the various city suburbs. This high quality imagery, together with accurate LiDAR data over the area and publically available volunteered geographic imagery through repositories such as Flickr, enabled the reconstruction of flood extents and the assessment of both area and depth of inundation for the assessment of damage. In this study, approximately 20 images of flood damaged properties were utilised to identify the peak of the flood. Accurate position and height values were determined through the use of RTK GPS and conventional survey methods. This information was then utilised in conjunction with river gauge information to generate a digital flood surface. The LiDAR generated DEM was then intersected with the flood surface to reconstruct the area of inundation. The model determined areas of inundation were then compared to the mapped flood extent from the high resolution digital imagery to assess the accuracy of the process. The paper concludes that accurate flood extent prediction or mapping is possible through this method, although its accuracy is dependent on the number and location of sampled points. The utilisation of LiDAR generated DEMs and DSMs can also provide an excellent mechanism to estimate depths of inundation and hence flood damage

  16. The influence of changes in glacier extent and surface elevation on modeled mass balance

    Directory of Open Access Journals (Sweden)

    F. Paul

    2010-06-01

    Full Text Available Glaciers are widely recognized as unique demonstration objects for climate change impacts, mostly due to the strong change of glacier length in response to small climatic changes. However, glacier mass balance as the direct response to the annual atmospheric conditions can be better interpreted in meteorological terms. When the climatic signal is deduced from long-term mass balance data, changes in glacier geometry (i.e. surface extent and elevation must be considered as such adjustments form an essential part of the glacier reaction to new climatic conditions. In this study, a set of modeling experiments is performed to assess the influence of changes in glacier geometry on mass balance for constant climatic conditions. The calculations are based on a simplified distributed energy/mass balance model in combination with information on glacier extent and surface elevation for the years 1850 and 1973/1985 for a larger sample of glaciers in the Swiss Alps. The results reveal that about 50–70% of the glacier reaction to climate change (here a one degree increase in temperature is "hidden" in the geometric adjustment, while only 30–50% can be measured as the long-term mean mass balance. Thereby, changes in glacier extent alone have an even stronger effect, but they are partly compensated for by a lowered surface elevation which gives on average a slightly more negative balance despite an increase of topographic shading. In view of several additional reinforcement feedbacks that are observed in periods of strong glacier decline, it seems that the climatic interpretation of mass balance data is also rather complex.

  17. Location, timing and extent of wildfire vary by cause of ignition

    Science.gov (United States)

    Syphard, Alexandra D.; Keeley, Jon E.

    2015-01-01

    The increasing extent of wildfires has prompted investigation into alternative fire management approaches to complement the traditional strategies of fire suppression and fuels manipulation. Wildfire prevention through ignition reduction is an approach with potential for success, but ignitions result from a variety of causes. If some ignition sources result in higher levels of area burned, then ignition prevention programmes could be optimised to target these distributions in space and time. We investigated the most common ignition causes in two southern California sub-regions, where humans are responsible for more than 95% of all fires, and asked whether these causes exhibited distinct spatial or intra-annual temporal patterns, or resulted in different extents of fire in 10-29-year periods, depending on sub-region. Different ignition causes had distinct spatial patterns and those that burned the most area tended to occur in autumn months. Both the number of fires and area burned varied according to cause of ignition, but the cause of the most numerous fires was not always the cause of the greatest area burned. In both sub-regions, power line ignitions were one of the top two causes of area burned: the other major causes were arson in one sub-region and power equipment in the other. Equipment use also caused the largest number of fires in both sub-regions. These results have important implications for understanding why, where and how ignitions are caused, and in turn, how to develop strategies to prioritise and focus fire prevention efforts. Fire extent has increased tremendously in southern California, and because most fires are caused by humans, ignition reduction offers a potentially powerful management strategy, especially if optimised to reflect the distinct spatial and temporal distributions in different ignition causes.

  18. Scope and extent of participation of female volunteers in tobacco control activities in Kerala, India

    Directory of Open Access Journals (Sweden)

    J Sreedharan

    2010-01-01

    Full Text Available Background : In India, NGOs play a key role in creating a supportive environment for the control of tobacco consumption. Aims : This study was conducted to assess the scope and the extent to which community-based women organizations are involved in tobacco control activities. To assess the scope and extent of participation in tobacco control activities according to the sociodemographic characteristics and also the extent to which they have participated in tobacco control activities. Settings and Design : The participants were Kudumbasree volunteers from the rural areas of Kannur district of Kerala state, India. This population-based study adopted a cross-sectional design. Materials and Methods : A self-administered, structured, close-ended, pre-tested questionnaire was prepared and used to collect data from 1000 female volunteers who participated in the study. Statistical Analysis : Chi-square test was used to compare nonparametric variables, such as education, marital status, and age with attitude toward tobacco control activities. Results : Age of the participants ranged from 17 to 53 years. The association between education level and positive attitude to participate in tobacco control activities was found to be statistically significant (P < 0.001. A statistically significant association between participation in tobacco control activities and marital status (P < 0.001 was observed. With regard to education and readiness/willingness to participate in tobacco control activities, in all the education groups more than 90% were willing to participate in tobacco control activities. Among the ever married participants, 98% were willing to participate in antitobacco activities. Old age, husband working in a beedi factory, or not being able to make frequent visits were the reasons reported for their unwillingness of the remaining people. Conclusion : Based on the findings, a set of Kudumbasree volunteers were trained in tobacco and health to work in

  19. Extent of linkage disequilibrium and effective population size in four South African Sanga cattle breeds

    Directory of Open Access Journals (Sweden)

    Sithembile Olga Makina

    2015-12-01

    Full Text Available Knowledge on the extent of linkage disequilibrium (LD in livestock populations is essential to determine the minimum distance between markers required for effective coverage when conducting genome-wide association studies. This study evaluated the extent of LD, persistence of allelic phase and effective population size (Ne for four Sanga cattle breeds in South Africa including the Afrikaner (n=44, Nguni (n=54, Drakensberger (n=47 and Bonsmara breeds (n=46, using Angus (n=31 and Holstein (n=29 as reference populations. We found that moderate LD extends up to inter-marker distances of 40-60 kb in Angus (0.21 and Holstein (0.21 and up to 100 kb in Afrikaner (0.20. This suggests that genomic selection and association studies performed within these breeds using an average inter-marker r2 ≥ 0.20 would require about 30,000 -50,000 SNPs. However, r2 ≥ 0.20 extended only up to 10-20 kb in the Nguni and Drakensberger and 20-40 kb in the Bonsmara indicating that 75,000 to 150,000 SNPs would be necessary for genome-wide association studies in these breeds. Correlation between alleles at contiguous loci indicated that phase was not strongly preserved between breeds. This suggests the need for breed-specific reference populations in which a much greater density of markers should be scored to identify breed specific haplotypes which may then be imputed into multi-breed commercial populations. Analysis of effective population size based on the extent of LD, revealed Ne=95 (Nguni, Ne=87 (Drakensberger, Ne=77 (Bonsmara and Ne=41 (Afrikaner. Results of this study form the basis for implementation of genomic selection programs in the Sanga breeds of South Africa.

  20. Sensitivity analysis of hydraulic model to morphological changes and changes in flood inundation extent

    Science.gov (United States)

    Wong, J. S.; Freer, J.; Bates, P. D.; Sear, D. A.

    2012-04-01

    Recent research into modelling floodplain inundation processes is primarily concentrated on the simulation of inundation flow without considering the influences of channel morphology and sediment delivery from upstream. River channels are often represented by simplified geometry and implicitly assumed to remain unchanged. However, during and after flood episodes the river bed elevation can change quickly and in some cases drastically. Despite this, the effect of channel geometry and topographic complexity on model results has been largely unexplored. To address this issue, the impact of channel cross-section geometry, and channel long-profile variability on flood inundation extent are examined using a simplified 1D-2D hydraulic model (LISFLOOD-FP) of the Cockermouth floods of November 2009 within an uncertainty analysis framework. The Cockermouth region provides a useful test site for such study because of the availability of channel and floodplain data, the collection of post-event water and wrack marks and the presence of pre-and post-event morphological surveyed data. More importantly, in some areas the river has undergone significant course change and additionally the deposition of stones and debris on the floodplain. The use of relatively simple formulations of critical velocities in the initiation of motion formula enables the construction of a series of hypothetical bedform scenarios among cross-sections. These scenarios can be used as input to LISFLOOD-FP. Slope gradient, Manning roughness coefficients, grain size characteristic, and critical shear stress will be considered in a Monte Carlo simulation framework. The November 2009 Cockermouth flood is simulated and the results are analysed to quantify the accuracy associated with each bedform scenario and to assess how different channel long-profiles affects the performance of LISFLOOD-FP. The study will further analyse and quantify the variability and uncertainty of flood inundation extent resulting from

  1. Residual stress simulation of circumferential welded joints

    Directory of Open Access Journals (Sweden)

    Melicher R.

    2007-11-01

    Full Text Available Residual stresses are an important consideration in the component integrity and life assessment of welded structure. The welding process is very complex time dependent physical phenomenon with material nonlinearity. The welding is a thermal process with convection between fluid flow and welding body, between welding bodyand environment. Next type of boundary conditions is radiation and thermo-mechanical contact on the outer surface of gas pipe in the near of weld. The temperature variation so obtained is utilised to find the distribution of the stress field.In this paper, a brief review of weld simulation and residual stress modelling using the finite element method (FEM by commercial software ANSYS is presented. Thermo-elastic-plastic formulations using a von Mises yield criterion with nonlinear kinematics hardening has been employed. Residual axial and hoop stresses obtained from the analysis have been shown. The commercial FEM code ANSYS was used for coupled thermalmechanical analysis.

  2. Assessing the extent and effects of herbicide drift into Danish hedgerows

    DEFF Research Database (Denmark)

    Pedersen, Marianne Bruus; Andersen, H. V.; Strandberg, M. T.

    Very low dosages of herbicides are known to cause effects on bird cherry (Prunus avium) and hawthorn (Crataegus monogyna). It is not yet known whether other hedgerow trees and shrubs are equally sensitive to herbicide drift, to which extent spray drift into hedges and other habitats close to fields...... was performed with a common tractor sprayer in five tracks parallel to the hedgerow, and either the herbicide metsulfuron methyl in combination with the dye fluorescein or fluorescein alone was applied. Deposition in the hedgerow and 12-48 m into the field was measured. Herbicide effects on hawthorn fruit set...

  3. Circumpolar thinning of Arctic sea ice following the 2007 record ice extent minimum

    OpenAIRE

    Giles, K.A.; Laxon, S. W.; Ridout, A. L.

    2008-01-01

    September 2007 marked a record minimum in sea ice extent. While there have been many studies published recently describing the minimum and its causes, little is known about how the ice thickness has changed in the run up to, and following, the summer of 2007. Using satellite radar altimetry data, covering the Arctic Ocean up to 81.5 degrees North, we show that the average winter sea ice thickness anomaly, after the melt season of 2007, was 0.26 m below the 2002/2003 to 2007/2008 average. More...

  4. To what extent do nurses use research in clinical practice? A systematic review

    Directory of Open Access Journals (Sweden)

    O'Rourke Hannah M

    2011-03-01

    Full Text Available Abstract Background In the past forty years, many gains have been made in our understanding of the concept of research utilization. While numerous studies exist on professional nurses' use of research in practice, no attempt has been made to systematically evaluate and synthesize this body of literature with respect to the extent to which nurses use research in their clinical practice. The objective of this study was to systematically identify and analyze the available evidence related to the extent to which nurses use research findings in practice. Methods This study was a systematic review of published and grey literature. The search strategy included 13 online bibliographic databases: Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, EMBASE, HAPI, Web of Science, SCOPUS, OCLC Papers First, OCLC WorldCat, ABI Inform, Sociological Abstracts, and Dissertation Abstracts. The inclusion criteria consisted of primary research reports that assess professional nurses' use of research in practice, written in the English or Scandinavian languages. Extent of research use was determined by assigning research use scores reported in each article to one of four quartiles: low, moderate-low, moderate-high, or high. Results Following removal of duplicate citations, a total of 12,418 titles were identified through database searches, of which 133 articles were retrieved. Of the articles retrieved, 55 satisfied the inclusion criteria. The 55 final reports included cross-sectional/survey (n = 51 and quasi-experimental (n = 4 designs. A sensitivity analysis, comparing findings from all reports with those rated moderate (moderate-weak and moderate-strong and strong quality, did not show significant differences. In a majority of the articles identified (n = 38, 69%, nurses reported moderate-high research use. Conclusions According to this review, nurses' reported use of research is moderate-high and has remained

  5. 241-AP Tank Farm Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Gunter, Jason R.; Reeploeg, Gretchen E.

    2014-04-04

    This report provides the results of an extent of condition construction history review for the 241-AP tank farm. The construction history of the 241-AP tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AP tank farm, the sixth double-shell tank farm constructed, tank bottom flatness, refractory material quality, post-weld stress relieving, and primary tank bottom weld rejection were improved.

  6. 241-SY Tank Farm Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-25

    This report provides the results of an extent of condition construction history review for tanks 241-SY-101, 241-SY-102, and 241-SY-103. The construction history of the 241-SY tank farm has been reviewed to identify issues similar to those experienced during tank 241-AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank 241-AY-102 as the comparison benchmark. In the 241-SY tank farm, the third DST farm constructed, refractory quality and stress relief were improved, while similar tank and liner fabrication issues remained.

  7. 241-AZ Tank Farm Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-30

    This report provides the results of an extent of condition construction history review for tanks 241-AZ-101 and 241-AZ-102. The construction history of the 241-AZ tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AZ tank farm, the second DST farm constructed, both refractory quality and tank and liner fabrication were improved.

  8. Summer atmospheric circulation anomalies over the Arctic Ocean and their influences on September sea ice extent: A cautionary tale

    Science.gov (United States)

    Serreze, Mark C.; Stroeve, Julienne; Barrett, Andrew P.; Boisvert, Linette N.

    2016-10-01

    Numerous studies have addressed links between summer atmospheric circulation patterns and interannual variability and the downward trend in total September Arctic sea ice extent. In general, low extent is favored when the preceding summer is characterized by positive sea level pressure (SLP) anomalies over the central Arctic Ocean north of Alaska. High extent is favored when low pressure dominates. If such atmospheric patterns could be predicted several months out, these links provide an avenue for improved seasonal predictability of total September extent. We analyze detrended September extent time series (1979-2015), atmospheric reanalysis fields, ice age and motion, and Atmospheric Infrared Sounder data, to show that while there is merit to this summer circulation framework, it has limitations. Large departures in total September extent relative to the trend line are preceded by a wide range of summer circulation patterns. While patterns for the four years with the largest positive departures in September extent have below average SLP over the central Arctic Ocean, they differ markedly in the magnitude and location of pressure and air temperature anomalies. Differences in circulation for the four years with the largest negative departures are equally prominent. Circulation anomalies preceding Septembers with ice extent close to the trend also have a wide range of patterns. In turn, years (such as 2013 and 2014) with almost identical total September extent were preceded by very different summer circulation patterns. September ice conditions can also be strongly shaped by events as far back as the previous winter or spring.

  9. Virtual cardioscopy: interactive endocardial visualization to guide RF cardiac ablation

    Science.gov (United States)

    Holmes, David R., III; Rettmann, Maryam E.; Cameron, Bruce M.; Camp, Jon J.; Robb, Richard A.

    2006-03-01

    Cardiac arrhythmias are a debilitating, potentially life threatening condition involving aberrant electrical activity in the heart which results in abnormal heart rhythm. Virtual cardioscopy can play an important role in minimally invasive treatment of cardiac arrhythmias. Second and third generation image-guidance systems are now available for the treatment of arrhythmias using RF ablation catheters. While these 3D tools provide useful information to the clinician, additional enhancements to the virtual cardioscopy display paradigm are critical for optimal therapy guidance. Based on input from clinical collaborators, several key visualization techniques have been developed to enhance the use of virtual cardioscopy during cardiac ablation procedures. We have identified, designed and incorporated several visual cues important to successful virtual cardioscopy. These features include the use of global reference maps, parametric mapping, and focused navigation and targeting using abnormal electro-physiologic activity. Our virtual cardioscopy system is designed for real-time use during RF cardiac ablation procedures. Several unique visualizations from our virtual cardioscopy system will be presented. Evaluation of the system with phantom and animal studies will be presented. This research is supported by grant EB002834 from the National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health.

  10. Origin of strong chiroptical activities in films of nonafluorenes with a varying extent of pendant chirality.

    Science.gov (United States)

    Geng, Yanhou; Trajkovska, Anita; Culligan, Sean W; Ou, Jane J; Chen, H M Philip; Katsis, Dimitris; Chen, Shaw H

    2003-11-19

    Novel nonafluorenes with a varying extent of pendant chirality were synthesized for an investigation of the origins of chiroptical activities in neat films. Thermal annealing of 4-microm-thick sandwiched films and of 90-nm-thick spin-cast films, all on surface-treated substrates, produced monodomain glassy films characterized as a right-handed cholesteric stack with a helical pitch length ranging from 180 to 534 nm and from 252 to 1151 nm, respectively. The observed strong circular dichroism (CD) and g(e) as functions of helical pitch length in single-substrate monodomain glassy cholesteric films were quantitatively interpreted with a circularly polarized fluorescence theory accounting for light absorption, emission, and propagation in a cholesteric stack. Although intertwined molecular helices were likely to be present, cholesteric stacking of rodlike molecules seemed to be the predominant contributor to the strong chiroptical activities. All the cholesteric stacks comprising a polydomain glassy film on an untreated substrate were found to contribute to CD and g(e) largely to the same extent as in a monodomain film. A circularly polarized blue organic light-emitting diode containing a nonafluorene film resulted in a g(e) of 0.35 with a luminance yield of 0.94 cd/A at 20 mA/cm(2), the best performance to date.

  11. Update on the Greenland Ice Sheet Melt Extent: 1979-1999

    Science.gov (United States)

    Abdalati, Waleed; Steffen, Konrad

    2000-01-01

    Analysis of melt extent on the Greenland ice sheet is updated to span the time period 1979-1999 is examined along with its spatial and temporal variability using passive microwave satellite data. In order to acquire the full record, the issue of continuity between previous passive microwave sensors (SMMR, SSM/I F-8, and SSM/I F-11), and the most recent SSM/I F-13 sensor is addressed. The F-13 Cross-polarized gradient ratio (XPGR) melt-classification threshold is determined to be -0.0154. Results show that for the 21-year record, an increasing melt trend of nearly 1 %/yr is observed, and this trend is driven by conditions on in the western portion of the ice sheet, rather than the east, where melt appears to have decreased slightly. Moreover, the eruption of Mt. Pinatubo in 1991 is likely to have had some impact the melt, but not as much as previously suspected. The 1992 melt anomaly is 1.7 standard deviations from the mean. Finally, the relationship between coastal temperatures and melt extent suggest an increase in surface runoff contribution to sea level of 0.31 mm/yr for a 1 C temperature rise.

  12. The Impact of a Lower Sea Ice Extent on Arctic Greenhouse Gas Exchange

    Science.gov (United States)

    Parmentier, Frans-Jan W.; Christensen, Torben R.; Lotte Sørensen, Lise; Rysgaard, Søren; McGuire, A. David; Miller, Paul A.; Walker, Donald A.

    2013-04-01

    Arctic sea ice extent hit a new record low in September 2012, when it fell to a level about two times lower than the 1979-2000 average. Record low sea ice extents such as these are often hailed as an obvious example of the impact of climate change on the Arctic. Less obvious, however, are the further implications of a lower sea ice extent on Arctic greenhouse gas exchange. For example, a reduction in sea ice, in consort with a lower snow cover, has been connected to higher surface temperatures in the terrestrial part of the Arctic (Screen et al., 2012). These higher temperatures and longer growing seasons have the potential to alter the CO2 balance of Arctic tundra through enhanced photosynthesis and respiration, as well as the magnitude of methane emissions. In fact, large changes are already observed in terrestrial ecosystems (Post et al., 2009), and concerns have been raised of large releases of carbon through permafrost thaw (Schuur et al., 2011). While these changes in the greenhouse gas balance of the terrestrial Arctic are described in numerous studies, a connection with a decline in sea ice extent is nonetheless seldom made. In addition to these changes on land, a lower sea ice extent also has a direct effect on the exchange of greenhouse gases between the ocean and the atmosphere. For example, due to sea ice retreat, more ocean surface remains in contact with the atmosphere, and this has been suggested to increase the oceanic uptake of CO2 (Bates et al., 2006). However, the sustainability of this increased uptake is uncertain (Cai et al., 2010), and carbon fluxes related directly to the sea ice itself add much uncertainty to the oceanic uptake of CO2 (Nomura et al., 2006; Rysgaard et al., 2007). Furthermore, significant emissions of methane from the Arctic Ocean have been observed (Kort et al., 2012; Shakhova et al., 2010), but the consequence of a lower sea ice extent thereon is still unclear. Overall, the decline in sea ice that has been seen in recent

  13. Windstorm of the eighteenth century in the Czech Lands: course, extent, impacts

    Science.gov (United States)

    Brázdil, Rudolf; Szabó, Péter; Dobrovolný, Petr; Řezníčková, Ladislava; Kotyza, Oldřich; Suchánková, Silvie; Valášek, Hubert

    2016-04-01

    This paper addresses the course, extent, and impacts of a windstorm that occurred on 20-21 December 1740, in the Czech Lands. The analysis is based on documentary data included in chronicles, "books of memory", memoirs, damage reports, urbaria, and cadastral records, as well as secondary sources. The windstorm started with a thunderstorm in the afternoon of 20 December, continued during the night, and was followed by a flood. It also appeared in documentary data from Bavaria, Thuringia, Saxony, Silesia, Slovakia, and Hungary. The event may be related to a cyclone north-west of the Czech territory moving to the east with an intense western flow over central Europe. The storm did great material damage to houses, farm buildings, churches, and forests and is recorded in various documentary sources for 85 places in the Czech Lands. The windstorm had a significant influence on the development of local plantation forestry (discussed in greater detail). Judging by territorial extent and damage done, this windstorm, compared to other similar events, has been classified as "the windstorm of the eighteenth century" in the Czech Lands. This contribution demonstrates the potential of documentary evidence for the elucidation of heavy windstorms in the pre-instrumental period in Europe.

  14. The impact of lower sea-ice extent on Arctic greenhouse-gas exchange

    Science.gov (United States)

    Parmentier, Frans-Jan W.; Christensen, Torben R.; Sørensen, Lise Lotte; Rysgaard, Søren; McGuire, A. David; Miller, Paul A.; Walker, Donald A.

    2013-01-01

    In September 2012, Arctic sea-ice extent plummeted to a new record low: two times lower than the 1979–2000 average. Often, record lows in sea-ice cover are hailed as an example of climate change impacts in the Arctic. Less apparent, however, are the implications of reduced sea-ice cover in the Arctic Ocean for marine–atmosphere CO2 exchange. Sea-ice decline has been connected to increasing air temperatures at high latitudes. Temperature is a key controlling factor in the terrestrial exchange of CO2 and methane, and therefore the greenhouse-gas balance of the Arctic. Despite the large potential for feedbacks, many studies do not connect the diminishing sea-ice extent with changes in the interaction of the marine and terrestrial Arctic with the atmosphere. In this Review, we assess how current understanding of the Arctic Ocean and high-latitude ecosystems can be used to predict the impact of a lower sea-ice cover on Arctic greenhouse-gas exchange.

  15. Urinary retinol binding protein is a marker of the extent of interstitial kidney fibrosis.

    Directory of Open Access Journals (Sweden)

    Nicolas Pallet

    Full Text Available Currently, a non-invasive method to estimate the degree of interstitial fibrosis (IF in chronic kidney disease is not available in routine. The aim of our study was to evaluate the diagnostic performance of the measurement of urinary low molecular weight (LMW protein concentrations as a method to determine the extent of IF. The urines specimen from 162 consecutive patients who underwent renal biopsy were used in the analysis. Numerical quantification software based on the colorimetric analysis of fibrous areas was used to assess the percentage IF. Total proteinuria, albuminuria, and the urinary levels of retinol binding protein (RBP, alpha1-microglobulin (α1MG, beta 2-microglobulin (β2MG, transferrin, and IgG immunoglobulins were measured. There was a significant correlation between the degree of IF and the RBP/creatinine (creat ratio (R2: 0.11, p25% of the parenchyma was 95% when using a threshold of 20 mg/g creat. In conclusion, RBP appears to be a quantitative and non-invasive marker for the independent prediction of the extent of kidney IF. Because methods for the measurement of urinary RBP are available in most clinical chemistry departments, RBP measurement is appealing for implementation in the routine care of patients with chronic kidney disease.

  16. Analysis of thoracic epidurography and correlating factors affecting the extent of contrast medium spread

    Science.gov (United States)

    Oh, Jung Hue; Park, Ki Bum

    2016-01-01

    Background Thoracic epidural anesthesia is frequently used to maintain intraoperative and postoperative analgesia. Frequently, 3 ml of local anesthetic is used as a test dose, or for intermittent epidural injection. We assessed the extent of the spread of 3 ml of contrast medium in the thoracic epidural space and attempted to identify any correlating factors affecting the epidurography. Methods A total of 70 patients were enrolled in the study, and thoracic epidural catheterizations were performed under fluoroscopic guidance. Using 3 ml of contrast medium, epidurography was evaluated to confirm the number of spinal segments covered by the contrast medium. Correlation analysis was performed between patient characteristics (sex, age, body mass index, weight, height, and location of catheter tip) and the extent of the contrast spread. Results The mean number of vertebral segments evaluated by contrast medium was 7.9 ± 2.2 using 3 ml of contrast medium. The contrast spread in the cranial direction showed more extensive distribution than that in the caudal direction, with statistical significance (P spread, and patient height showed a weak negative correlation with the distribution of contrast medium.

  17. Satellite and Surface Perspectives of Snow Extent in the Southern Appalachian Mountains

    Science.gov (United States)

    Sugg, Johnathan W.; Perry, Baker L.; Hall, Dorothy K.

    2012-01-01

    Assessing snow cover patterns in mountain regions remains a challenge for a variety of reasons. Topography (e.g., elevation, exposure, aspect, and slope) strongly influences snowfall accumulation and subsequent ablation processes, leading to pronounced spatial variability of snow cover. In-situ observations are typically limited to open areas at lower elevations (Mountains (SAM). MODIS daily snow cover maps and true color imagery are analyzed after selected snow events (e.g., Gulf/Atlantic Lows, Alberta Clippers, and Northwest Upslope Flow) from 2006 to 2012 to assess the spatial patterns of snowfall across the SAM. For each event, we calculate snow cover area across the SAM using MODIS data and compare with the Interactive Multi-sensor Snow and ice mapping system (IMS) and available in-situ observations. Results indicate that Gulf/Atlantic Lows are typically responsible for greater snow extent across the entire SAM region due to intensified cyclogenesis associated with these events. Northwest Upslope Flow events result in snow cover extent that is limited to higher elevations (>1000 m) across the SAM, but also more pronounced along NW aspects. Despite some limitations related to the presence of ephemeral snow or cloud cover immediately after each event, we conclude that MODIS products are useful for assessing the spatial variability of snow cover in heavily forested mountain regions such as the SAM.

  18. IceMap250—Automatic 250 m Sea Ice Extent Mapping Using MODIS Data

    Directory of Open Access Journals (Sweden)

    Charles Gignac

    2017-01-01

    Full Text Available The sea ice cover in the North evolves at a rapid rate. To adequately monitor this evolution, tools with high temporal and spatial resolution are needed. This paper presents IceMap250, an automatic sea ice extent mapping algorithm using MODIS reflective/emissive bands. Hybrid cloud-masking using both the MOD35 mask and a visibility mask, combined with downscaling of Bands 3–7 to 250 m, are utilized to delineate sea ice extent using a decision tree approach. IceMap250 was tested on scenes from the freeze-up, stable cover, and melt seasons in the Hudson Bay complex, in Northeastern Canada. IceMap250 first product is a daily composite sea ice presence map at 250 m. Validation based on comparisons with photo-interpreted ground-truth show the ability of the algorithm to achieve high classification accuracy, with kappa values systematically over 90%. IceMap250 second product is a weekly clear sky map that provides a synthesis of 7 days of daily composite maps. This map, produced using a majority filter, makes the sea ice presence map even more accurate by filtering out the effects of isolated classification errors. The synthesis maps show spatial consistency through time when compared to passive microwave and national ice services maps.

  19. Changing head model extent affects finite element predictions of transcranial direct current stimulation distributions

    Science.gov (United States)

    Indahlastari, Aprinda; Chauhan, Munish; Schwartz, Benjamin; Sadleir, Rosalind J.

    2016-12-01

    Objective. In this study, we determined efficient head model sizes relative to predicted current densities in transcranial direct current stimulation (tDCS). Approach. Efficiency measures were defined based on a finite element (FE) simulations performed using nine human head models derived from a single MRI data set, having extents varying from 60%-100% of the original axial range. Eleven tissue types, including anisotropic white matter, and three electrode montages (T7-T8, F3-right supraorbital, Cz-Oz) were used in the models. Main results. Reducing head volume extent from 100% to 60%, that is, varying the model’s axial range from between the apex and C3 vertebra to one encompassing only apex to the superior cerebellum, was found to decrease the total modeling time by up to half. Differences between current density predictions in each model were quantified by using a relative difference measure (RDM). Our simulation results showed that {RDM} was the least affected (a maximum of 10% error) for head volumes modeled from the apex to the base of the skull (60%-75% volume). Significance. This finding suggested that the bone could act as a bioelectricity boundary and thus performing FE simulations of tDCS on the human head with models extending beyond the inferior skull may not be necessary in most cases to obtain reasonable precision in current density results.

  20. The kinematic and microphysical control of lightning rate, extent, and NOX production

    Science.gov (United States)

    Carey, Lawrence D.; Koshak, William; Peterson, Harold; Mecikalski, Retha M.

    2016-07-01

    This study investigates the kinematic and microphysical control of lightning properties, particularly those that may govern the production of nitrogen oxides (NOX = NO + NO2) via lightning (LNOX), such as flash rate, type, and extent. The NASA Lightning Nitrogen Oxides Model (LNOM) is applied to lightning observations following multicell thunderstorms through their lifecycle in a Lagrangian sense over Northern Alabama on 21 May 2012 during the Deep Convective Clouds and Chemistry (DC3) experiment. LNOM provides estimates of flash rate, type, channel length distributions, channel segment altitude distributions (SADs), and LNOX production profiles. The LNOM-derived lightning characteristics and LNOX production are compared to the evolution of radar-inferred updraft and precipitation properties. Intercloud, intracloud (IC) flash SAD comprises a significant fraction of the total (IC + cloud-to-ground [CG]) SAD, while increased CG flash SAD at altitudes >6 km occurs after the simultaneous peaks in several thunderstorm properties (i.e., total [IC + CG] and IC flash rate, graupel volume/mass, convective updraft volume, and maximum updraft speed). At heights 6 km. Graupel volume/mass, updraft volume, and maximum updraft speed are all well correlated to the total flash rate (correlation coefficient, ρ ≥ 0.8) but are less correlated to total flash extent (ρ ≥ 0.6) and total LNOX production (ρ ≥ 0.5). Although LNOM transforms lightning observations into LNOX production values, these values are estimates and are subject to further independent validation.

  1. Conservation development practices, extent, and land-use effects in the United States.

    Science.gov (United States)

    Milder, Jeffrey C; Clark, Story

    2011-08-01

    Conservation development projects combine real-estate development with conservation of land and other natural resources. Thousands of such projects have been conducted in the United States and other countries through the involvement of private developers, landowners, land trusts, and government agencies. Previous research has demonstrated the potential value of conservation development for conserving species, ecological functions, and other resource values on private lands, especially when traditional sources of conservation funding are not available. Nevertheless, the aggregate extent and effects of conservation development were previously unknown. To address this gap, we estimated the extent and trends of conservation development in the United States and characterized its key attributes to understand its aggregate contribution to land-conservation and growth-management objectives. We interviewed representatives from land trusts, planning agencies, and development companies, searched the Internet for conservation development projects and programs, and compiled existing databases of conservation development projects. We collected data on 3884 projects encompassing 1.38 million ha. About 43% of the projects targeted the conservation of specific plant or animal species or ecological communities of conservation concern; 84% targeted the protection of native ecosystems representative of the project area; and 42% provided buffers to existing protected areas. The percentage of protected land in conservation development projects ranged from 99%, and the effects of these projects on natural resources differed widely. We estimate that conservation development projects have protected roughly 4 million ha of land in the United States and account for about 25% of private-land conservation activity nationwide.

  2. Assessment of spring floods and surface water extent over the Yamalo-Nenets Autonomous District

    Science.gov (United States)

    Trofaier, A. M.; Bartsch, A.; Rees, W. G.; Leibman, M. O.

    2013-12-01

    Remote sensing of Arctic water bodies is an essential method for monitoring the dynamics of frozen ground. Thaw lake change provides insight into the state of permafrost. In the vast Arctic and sub-Arctic areas capturing changes in lake extent is assisted by satellite data. In particular, active microwave sensors can be used in a straightforward manner for water body classifications. This study uses the pan-Siberian datasets that are provided under the ESA STSE-ALANIS methane project. Surface water classifications in 10-day intervals have been produced using Envisat ASAR (Advanced Synthetic Aperture Radar) operating in wide swath mode. The high temporal frequency of these data allows an investigation of surface hydrology on an intra-annual basis. The current study applies a post-processing algorithm to the ALANIS products in order to investigate changes in surface inundation across the Yamalo-Nenets Autonomous District over the summer period of 2007. Multiple areas are found to exhibit changes in surface inundation. Strong seasonal variations occur in areas where previous investigations determined disappearing lakes. Spring floods associated with the depletion of snow-cover and melt waters as well as floodplain dynamics can be identified. On the Yamal peninsula, these changes occur most dominantly in the west; an area subject to anthropogenic land-use change. Changes in water body extent for each hot spot of seasonal variations are quantified and discussed.

  3. Insight into glacier climate interaction: reconstruction of the mass balance field using ice extent data

    Science.gov (United States)

    Visnjevic, Vjeran; Herman, Frédéric; Licul, Aleksandar

    2016-04-01

    With the end of the Last Glacial Maximum (LGM), about 20 000 years ago, ended the most recent long-lasting cold phase in Earth's history. We recently developed a model that describes large-scale erosion and its response to climate and dynamical changes with the application to the Alps for the LGM period. Here we will present an inverse approach we have recently developed to infer the LGM mass balance from known ice extent data, focusing on a glacier or ice cap. The ice flow model is developed using the shallow ice approximation and the developed codes are accelerated using GPUs capabilities. The mass balance field is the constrained variable defined by the balance rate β and the equilibrium line altitude (ELA), where c is the cutoff value: b = max(βṡ(S(z) - ELA), c) We show that such a mass balance can be constrained from the observed past ice extent and ice thickness. We are also investigating several different geostatistical methods to constrain spatially variable mass balance, and derive uncertainties on each of the mass balance parameters.

  4. The extent and application of patient diaries in Danish ICUs in 2006

    DEFF Research Database (Denmark)

    Egerod, Ingrid; Schwartz-Nielsen, Kathrine Hvid; Hansen, Glennie Marie;

    2007-01-01

    The aim of this study was to describe the extent and application of patient diaries in Danish intensive care units (ICUs) in 2006. Following critical illness, many patients experience disturbed and disconnected memories. Patient diaries in the ICU have been introduced locally by nurses in the Sca......The aim of this study was to describe the extent and application of patient diaries in Danish intensive care units (ICUs) in 2006. Following critical illness, many patients experience disturbed and disconnected memories. Patient diaries in the ICU have been introduced locally by nurses...... in the Scandinavian countries and the UK as a means to improve cognitive recovery and prevent psychological trauma following critical illness. Descriptive design, using qualitative key informant telephone interviews (n= 19) was used as the source of data. A semi-structured interview guide was used and field notes...... from the interviews were mailed to the informants for verification and additional information. Nineteen out of 48 Danish ICUs use patient diaries. Patient diaries are mainly used for sedated, ventilated patients during critical illness. The purpose of diaries was mainly to assist memory due to post...

  5. Combining measurements to estimate properties and characterization extent of complex biochemical mixtures; applications to Heparan Sulfate

    Science.gov (United States)

    Pradines, Joël R.; Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Farutin, Victor; Huang, Yongqing; Gunay, Nur Sibel; Capila, Ishan

    2016-04-01

    Complex mixtures of molecular species, such as glycoproteins and glycosaminoglycans, have important biological and therapeutic functions. Characterization of these mixtures with analytical chemistry measurements is an important step when developing generic drugs such as biosimilars. Recent developments have focused on analytical methods and statistical approaches to test similarity between mixtures. The question of how much uncertainty on mixture composition is reduced by combining several measurements still remains mostly unexplored. Mathematical frameworks to combine measurements, estimate mixture properties, and quantify remaining uncertainty, i.e. a characterization extent, are introduced here. Constrained optimization and mathematical modeling are applied to a set of twenty-three experimental measurements on heparan sulfate, a mixture of linear chains of disaccharides having different levels of sulfation. While this mixture has potentially over two million molecular species, mathematical modeling and the small set of measurements establish the existence of nonhomogeneity of sulfate level along chains and the presence of abundant sulfate repeats. Constrained optimization yields not only estimations of sulfate repeats and sulfate level at each position in the chains but also bounds on these levels, thereby estimating the extent of characterization of the sulfation pattern which is achieved by the set of measurements.

  6. The Policies That Affect the Extent of the Subcultures' Alignment in Organization

    Directory of Open Access Journals (Sweden)

    Suela GERDHE

    2012-02-01

    Full Text Available The culture of the organization can be a strategic tool for the success of organization, because it influences how the organization conduct its business and helps regulate, control and model of the behavior in each subculture of the organization. Often, the subcultures are viewed by management as the representing tolerated deviations that do not disrupt the normative solidarity of the overall corporate culture’s dominant values. However, these deviations may become intolerable when there is significant value misalignment among the various subcultures within the organization. In such conditions, the lack of the subcultures’ alignment in organization is considered critical and important to manage. While diagnosing culture alignment of the “Pro Credit” bank in Albania, the article focuses on problems of alignment and techniques that improve the alignment of subcultures. For this purpose we estimate the extent to which individuals in each gender and generational subcultures agree or disagree with the culture’s dimensions. While, assess of the extent to which organization vision and values are understood and shared by subcultures within the organization, is in core of practical study.

  7. Earth observation data based rapid flood-extent modelling for tsunami-devastated coastal areas

    Science.gov (United States)

    Hese, Sören; Heyer, Thomas

    2016-04-01

    Earth observation (EO)-based mapping and analysis of natural hazards plays a critical role in various aspects of post-disaster aid management. Spatial very high-resolution Earth observation data provide important information for managing post-tsunami activities on devastated land and monitoring re-cultivation and reconstruction. The automatic and fast use of high-resolution EO data for rapid mapping is, however, complicated by high spectral variability in densely populated urban areas and unpredictable textural and spectral land-surface changes. The present paper presents the results of the SENDAI project, which developed an automatic post-tsunami flood-extent modelling concept using RapidEye multispectral satellite data and ASTER Global Digital Elevation Model Version 2 (GDEM V2) data of the eastern coast of Japan (captured after the Tohoku earthquake). In this paper, the authors developed both a bathtub-modelling approach and a cost-distance approach, and integrated the roughness parameters of different land-use types to increase the accuracy of flood-extent modelling. Overall, the accuracy of the developed models reached 87-92%, depending on the analysed test site. The flood-modelling approach was explained and results were compared with published approaches. We came to the conclusion that the cost-factor-based approach reaches accuracy comparable to published results from hydrological modelling. However the proposed cost-factor approach is based on a much simpler dataset, which is available globally.

  8. Disease incidence is related to bleaching extent in reef-building corals.

    Science.gov (United States)

    Brandt, Marilyn E; McManus, John W

    2009-10-01

    Recent outbreaks of coral bleaching and disease have contributed to substantial declines in the abundance of reef-building coral. Significant attention has been paid to both phenomena in order to determine their effect on reef trajectories. Although each is positively correlated with high temperatures, few studies have explored the potential links between bleaching and disease. A longitudinal study of corals in the Florida Keys was therefore conducted during the 2005 Caribbean bleaching event to quantify bleaching extent and disease incidence in corals, and to determine whether they were related or if they acted as discrete phenomena. These data indicated that overall, a positive correlation exists between bleaching extent and disease incidence. However, the specific interactions between these two phenomena varied among disease bleaching combinations. Montastraea faveolata colonies with greater bleaching intensities later developed white plague (WP) infections. Meanwhile, Siderastrea siderea colonies with dark spot disease (DS) bleached more extensively than apparently healthy colonies. Finally, bleaching and black band disease (BB) co-occurred on Colpophyllia natans throughout the bleaching event. WP, BB, and bleaching are each independently capable of changing the structure of coral populations through loss of living tissue, and DS is an important indicator of reef health. Understanding the dynamics of how these mortality sources interact is critical to understanding mortality patterns and predicting how reef communities will respond to future events.

  9. Testing models of ice cap extent, South Georgia, sub-Antarctic

    Science.gov (United States)

    Barlow, N. L. M.; Bentley, M. J.; Spada, G.; Evans, D. J. A.; Hansom, J. D.; Brader, M. D.; White, D. A.; Zander, A.; Berg, S.

    2016-12-01

    The extent of Last Glacial Maximum ice in South Georgia is contested, with two alternative hypotheses: an extensive (maximum) model of ice reaching the edge of the continental shelf, or a restricted (minimum) model with ice constrained within the inner fjords. We present a new relative sea-level dataset for South Georgia, summarising published and new geomorphological evidence for the marine limit and elevations of former sea levels on the island. Using a glacial isostatic adjustment model (ALMA) specifically suited to regional modelling and working at high spatial resolutions, combined with a series of simulated ice-load histories, we use the relative sea-level data to test between the restricted and extensive ice extent scenarios. The model results suggest that there was most likely an extensive Last Glacial Maximum glaciation of South Georgia, implying that the island was covered by thick (>1000 m) ice, probably to the edge of the continental shelf, with deglaciation occurring relatively early (ca. 15 ka BP, though independent data suggest this may have been as early as 18 ka). The presence of an extensive ice cap extending to the shelf edge would imply that if there were any biological refugia around South Georgia, they must have been relatively localised and restricted to the outermost shelf.

  10. Service provider-Customer Relationship: To What Extent Are Customers in Terengganu Being Respected?

    Directory of Open Access Journals (Sweden)

    Siti Haryati Shaikh Ali,

    2011-06-01

    Full Text Available Today’s rapidly changing environment is demanding service companies to seek more creative and flexible means for dealing with competition. In fact, more and more retailers are investing in relationship building as a strategy for enhancing customer retention in the business-to-customer (B2C context. From the literature, it is learnt that efforts are being concentrated in creating quality relationship with customers. This effort should include respecting customers. Respecting customers is one of the easiest ways to earn quality relationship with customers. However, the big question is to what extent does respect affect the quality of relationship between customer and service provider? The purpose of this study is to determine the dimensions of respect and to what extent it affects relationship quality. This preliminary study draws on empirical results from clients of banks and clinics in Kuala Terengganu. The hypotheses were tested using Pearson Correlation and Multiple Regression Analysis to examine the relationship between the three dimensions of respect and overall relationship quality. The results of the empirical tests give some support to the view that attention to the particularity, understanding and responsibility towards customers are crucial in shaping customers perception of respect and the quality of their relationship with service providers.

  11. Numerical Simulation of Flow Field in End Face Seal with Circumferential Waviness%端面周向波度密封中流场的数值模拟

    Institute of Scientific and Technical Information of China (English)

    孙赫; 张秋翔; 蔡纪宁; 李双喜

    2011-01-01

    建立端面周向波度密封密封端面间液膜流场的数值模型,采用计算流体力学软件FLUENT对密封间隙中的液膜进行三维数值模拟,得到液膜流场的压力分布,求得密封的泄漏量、开启力和刚度等密封特性参数,分析密封几何参数(如波幅、波数、密封环坝区的宽度与密封环宽度之比)对密封性能的影响.结果表明:随着液膜厚度的增加,开启力减小,泄漏量增大;密封几何参数对密封特性参数的影响存在一定的规律,如波幅越大、波数越多,密封环端面的流体动压效应越明显,而随密封环坝区的宽度与密封环宽度之比的增加,开启力、泄漏量和刚度都减小.%A theoretical analysis model of fluid film flow between the seal faces was established for the end face seal with circumferential waviness. By using the hydromechanics software FLUENT, a three-dimensional numerical simulation was performed for the liquid film of the seal gap, the pressure distribution of the liquid film flow was got, and the seal characteristic parameters, such as leakage, opening force and stiffness of seal were obtained. The effect of seal geometric parameters, such as wave amplitude, wave number and the rate of breadth of seal dam zone and seal breadth, on seal performance was analyzed. Results show that with the increase of fluid film thickness, the opening force is reduced and the leakage increased. There is certain law existed between the seal geometric parameters and the seal characteristic parameters, that there is obvious hydrodynamic pressure effect in seal ring end face for the seal with big wave amplitude and more wave number. With the increase of the rate of breadth of seal dam zone and seal breadth, the opening force, leakage and stiffness are reduced.

  12. SOM-based Hybrid Neural Network Model for Flood Inundation Extent Forecasting

    Science.gov (United States)

    Chang, Li-Chiu; Shen, Hung-Yu; Chang, Fi-John

    2014-05-01

    In recent years, the increasing frequency and severity of floods caused by climate change and/or land overuse has been reported both nationally and globally. Therefore, estimation of flood depths and extents may provide disaster information for alleviating risk and loss of life and property. The conventional inundation models commonly need a huge amount of computational time to carry out a high resolution spatial inundation map. Moreover, for implementing appropriate mitigation strategies of various flood conditions, different flood scenarios and the corresponding mitigation alternatives are required. Consequently, it is difficult to reach real-time forecast of the inundation extent by conventional inundation models. This study proposed a SOM-RNARX model, for on-line forecasting regional flood inundation depths and extents. The SOM-RNARX model is composed of SOM (Self-Organizing Map) and RNARX (recurrent configuration of nonlinear autoregressive with exogenous inputs). The SOM network categorizes various flood inundation maps of the study area to produce a meaningful regional flood topological map. The RNARX model is built to forecast the total flooded volume of the study area. To find the neuron with the closest total inundated volume to the forecasted total inundated volumes, the forecasted value is used to adjust the weights (inundated depths) of the closest neuron and obtain a regional flood inundation map. The proposed methodology was trained and tested based on a large number of inundation data generated by a well validated two-dimensional simulation model in Yilan County, Taiwan. For comparison, the CHIM (clustering-based hybrid inundation model) model which was issued by Chang et al. (2010) was performed. The major difference between these two models is that CHIM classify flooding characteristics, and SOM-RNARX extracts the relationship between rainfall pattern and flooding spatial distribution. The results show that (1)two models can adequately provide on

  13. Extent of the Disturbed Rock Zone Around a WIPP Disposal Room

    Science.gov (United States)

    Herrick, C. G.; Park, B. Y.; Holcomb, D. J.

    2008-12-01

    The Waste Isolation Pilot Plant (WIPP), located in southeastern New Mexico, is operated by the U.S. Department of Energy (DOE) as the underground disposal facility for transuranic (TRU) nuclear waste. It is located in a bedded salt formation at a depth of about 650 m. Salt at this depth behaves as a viscous material having an initially lithostatic state of stress. Mining of an opening disturbs the static equilibrium to a degree where fracturing of the rock surrounding a room occurs, changing its mechanical and hydrologic properties. This disturbed rock zone (DRZ) is an important geomechanical feature included in the performance assessment process models used to predict future repository conditions as a part of certification by the EPA as meeting regulatory compliance. Based on ongoing scientific investigations and evaluation of published data since the original certification in 1998, our understanding of the DRZ has continued to progress. Three deformation processes are activated as deviatoric stresses are induced upon excavation of a room in a salt formation: (1) elastic response, (2) inelastic viscoplastic flow, and (3) inelastic- damage induced flow. Damage, the least understood of these processes, is manifested by the time- dependent initiation, growth, coalescence, and healing of microfractures with a deviatoric stress state. Since the ability to model the spatial and temporal changes in salt damage is not available at this time, various means to measure it have been attempted. At the WIPP, for this study, we used sonic velocity measurements obtained over a 12 year period as the principal field method to describe the extent of the DRZ. Predictions of the DRZ extent based on these experimental results are substantiated by permeability measurements and microfracture density analysis from other places in the repository. Extensive laboratory salt creep data demonstrate that damage can be assessed in terms of volumetric strain and principal stresses. Stress states

  14. 45 CFR 2505.3 - To what extent are meetings of the Board open to the public?

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false To what extent are meetings of the Board open to... To what extent are meetings of the Board open to the public? The Board shall conduct meetings, as defined in § 2505.2, in accordance with this part. Except as provided in § 2505.4, the Board's...

  15. Extent of resection of peritumoral diffusion tensor imaging-detected abnormality as a predictor of survival in adult glioblastoma patients

    NARCIS (Netherlands)

    Yan, Jiun-Lin; van der Hoorn, Anouk; Larkin, Timothy J.; Boonzaier, Natalie R.; Matys, Tomasz; Price, Stephen J.

    2017-01-01

    OBJECTIVE Diffusion tensor imaging (DTI) has been shown to detect tumor invasion in glioblastoma patients and has been applied in surgical planning. However, the clinical value of the extent of resection based on DTI is unclear. Therefore, the correlation between the extent of resection of DTI abnor

  16. Extent of resection of peritumoral diffusion tensor imaging-detected abnormality as a predictor of survival in adult glioblastoma patients

    NARCIS (Netherlands)

    Yan, Jiun-Lin; van der Hoorn, Anouk; Larkin, Timothy J; Boonzaier, Natalie R; Matys, Tomasz; Price, Stephen J

    2016-01-01

    OBJECTIVE Diffusion tensor imaging (DTI) has been shown to detect tumor invasion in glioblastoma patients and has been applied in surgical planning. However, the clinical value of the extent of resection based on DTI is unclear. Therefore, the correlation between the extent of resection of DTI abnor

  17. In vitro estimation of the rate and extent of ruminal digestion of cereal feed fraction

    DEFF Research Database (Denmark)

    Tahir, M.N.; Lund, Peter; Hetta, M.

    2011-01-01

    by their physical and chemical properties and might be ranked as highly and poorly degrading starch after their extent and rate of degradation in rumen (Nocek and Tamminga, 1991). It is hypothesized that rumen fermentation rate of cereal starch varies considerably and that this might affect fibre digestibility......Cereal grains are important components in diets for high producing dairy cows and fast growing beef cattle. The most important feed fraction in cereals is starch, which constitutes the major portion (70-80%) of cereal grains. In ruminant nutrition different starch sources are characterized......, forage intake, and animal performance (Nocek and Tamminga, 1991; Mills et al., 1999). It would, therefore, be useful to reliably determine the differences in rumen fermentation characteristics of cereals. Part of the variation can be attributed to the methods used for evaluation (Stensig et al., 1998b...

  18. Stresses and Displacements in Functionally Graded Materials of Semi-Infinite Extent Induced by Rectangular Loadings

    Directory of Open Access Journals (Sweden)

    Zhong-Qi Yue

    2012-01-01

    Full Text Available This paper presents the stress and displacement fields in a functionally graded material (FGM caused by a load. The FGM is a graded material of Si3N4-based ceramics and is assumed to be of semi-infinite extent. The load is a distributed loading over a rectangular area that is parallel to the external surface of the FGM and either on its external surface or within its interior space. The point-load analytical solutions or so-called Yue’s solutions are used for the numerical integration over the distributed loaded area. The loaded area is discretized into 200 small equal-sized rectangular elements. The numerical integration is carried out with the regular Gaussian quadrature. Weak and strong singular integrations encountered when the field points are located on the loaded plane, are resolved with the classical methods in boundary element analysis. The numerical integration results have high accuracy.

  19. Presence and extent of the primary health care attributes among children hospitalized for pneumonia

    Directory of Open Access Journals (Sweden)

    Juliana Coelho Pina

    2015-06-01

    Full Text Available OBJECTIVE: to analyze the presence and extent of the primary health care attributes among children hospitalized for pneumonia.METHOD: observational and retrospective study with hospital-based case-control design, developed in three hospitals associated to the Brazilian Unified Health System, located in a city of the State of São Paulo, Brazil. The study included 690 children under five years old, with 345 cases and 345 controls.RESULTS: both groups scored high for access to health services. In contrast, high scores for attributes such as longitudinality and coordination of care were observed for the controls. Despite low scores, integrality and family counseling were also high for the controls.CONCLUSION: knowledge of the aspects involving the primary health care attributes and its provision for child care are very important because they have the potential to support professionals and managers of the Brazilian Unified Health System in the organization of health services.

  20. To what extent did the 1858 Medical Act bring unity to the British medical profession?

    Science.gov (United States)

    Beard, John A S

    2013-05-01

    The Medical Act of 1858 was the culmination of medical, political and social wrangling for several decades before its passage. This essay looks to place the Act in its correct historical context and will specifically consider whether it brought about unity to what was a disparate and factional profession. That it was an important piece of legislation in the history of British healthcare is unquestioned, but the extent to which it directly brought about change is more uncertain. In order to understand the background, content and repercussions of the Act, one must recognize the structure of the medical system at that time. One reason for doing this, as argued by some, is that the Medical Act, like the Apothecaries Act of 1815, was the result of changes to the profession and not the cause of them. Reformists hoped that the Medical Act would unify the profession, yet significant historical, hierarchical and political barriers stood in the way of reform.

  1. Initial Temperature and Extent of Chemical Equilibration of Partons in Relativistic Collision of Heavy Nuclei

    CERN Document Server

    Srivastava, Dinesh K; Mustafa, Munshi G

    2016-01-01

    We emphasize that a knowledge of energy and entropy densities of quark gluon plasma - a thermalized de-confined matter, formed in relativistic heavy ion collisions fixes the formation temperature and the product of gluon fugacity and formation time uniquely, {\\em provided} we know the relative fugacities of quarks and gluons. This also provides that a smaller formation time would imply larger fugacities for partons. Next we explore the limits of chemical equilibration of partons during the initial stages in relativistic collision of heavy nuclei. The experimentally measured rapidity densities of transverse energy and charged particle multiplicity at RHIC and LHC energies are used to estimate the energy and number densities with the assumption of formation of a thermally equilibrated quark gluon plasma which may be chemically equilibrated to the same or differing extents for quarks and gluons. The estimates are found to be very sensitive to the correction factor used for the Bj\\"{o}rken energy density for iden...

  2. Principles for the monitoring and evaluation of wetland extent, condition and function in Australia.

    Science.gov (United States)

    Saintilan, Neil; Imgraben, Sarah

    2012-01-01

    The monitoring of resource condition is receiving renewed attention across several levels of government in Australia. This interest is linked to substantial investment in environmental remediation and aquatic ecosystem restoration in particular. In this context, it is timely to consider principles which ought to guide the development and implementation of monitoring programmes for wetland ecosystems. A framework is established which places monitoring in the context of the strategic adaptive management of wetlands. This framework requires there has to be clear goals for the extent and condition of the resource, with these goals being defined within thresholds of acceptable variability. Qualitative and, where possible, quantitative conceptual models linking management interventions to management goals should be the basis of indicator selection and assessment. The intensity of sampling ought to be informed by pilot surveys of statistical power in relation to the thresholds of acceptable variability identified within the management plan.

  3. Sources, extent and history of methane seepage on the continental shelf off northern Norway

    Science.gov (United States)

    Sauer, Simone; Lepland, Aivo; Chand, Shyam; Schubert, Carsten J.; Eichinger, Florian; Knies, Jochen

    2014-05-01

    Active natural hydrocarbon gas seepage was recently discovered in the Hola area on the continental shelf off Vesterålen, northern Norway. We conducted acoustic and geochemical investigations to assess the modern and past extent, source and pathways of the gas seepage . Water column echosounder surveys showed bubble plumes up to several tens of metres above the seafloor. Analyses of dissolved methane in the water column indicated slightly elevated concentrations (50 nM) close to the seafloor. To identify fluxes and origin of methane in the sediments we analysed sediment pore water chemistry, the isotopic composition of methane and of dissolved inorganic carbon (d13CCH4, d2HCH4, d13CDIC) in three closely spaced (

  4. NATURE AND EXTENT OF PROBLEMS OF AGRO-GRAZIERS IN BHAWALPUR DISTRICT, PAKISTAN

    Directory of Open Access Journals (Sweden)

    M. B. AZAM, Z. H. KHAN, S. YAQOOB AND R. A. KHAN

    2009-02-01

    Full Text Available Studies on nature and extent of problems faced by agro-graziers were carried out in Bhawalpur district of Southern Punjab, Pakistan during 1991. Non cooperative attitude of government departments and farmers for not allowing agro-graziers to graze their animals along canals, forests, rangelands, irrigated plantations and agricultural fields was a very common problem. Due to poverty, agro-graziers were unable to purchase costly concentrates and cultivated fodders to feed their animals. They could not buy veterinary medicines to cure their animals against different diseases. Moreover, no loan subsidy, financial assistance or credit was granted by the Government for the alleviation of poverty of agro-graziers. In addition, 30 and 35% agro-graziers in the district faced problems of shortage or non availability of forage and water, respectively.

  5. An Exploratory Study of the Nature and Extent of Nonsuicidal Self-Injury among College Women

    Directory of Open Access Journals (Sweden)

    Efrosini D. Kokaliari

    2014-01-01

    Full Text Available This study assessed the extent and nature of nonsuicidal self-injury (NSSI among 165 students attending an all-women’s college. Associations between NSSI behaviors and demographics, borderline personality disorder (BPD, posttraumatic stress disorder (PTSD, and attachment styles were investigated. Statistically significant relationships between the severity of NSSI and demographic characteristics and BPD and PTSD were explored using bivariate analysis. Within this population, presence of NSSI behavior was significantly associated with age, years in college, nonheterosexual orientation, BPD, PTSD, and preoccupied attachment styles. There were also marginally significant associations with race and financial status. Severity of NSSI behaviors was significantly associated with age, years in college, BPD pathology, and primary parent’s level of education. A logistic regression analysis was developed that predicted NSSI behavior with 67% accuracy based on these findings. This study has implications for clinical practice.

  6. FUZZY MODEL OPTIMIZATION FOR TIME SERIES DATA USING A TRANSLATION IN THE EXTENT OF MEAN ERROR

    Directory of Open Access Journals (Sweden)

    Nurhayadi

    2014-01-01

    Full Text Available Recently, many researchers in the field of writing about the prediction of stock price forecasting, electricity load demand and academic enrollment using fuzzy methods. However, in general, modeling does not consider the model position to actual data yet where it means that error is not been handled optimally. The error that is not managed well can reduce the accuracy of the forecasting. Therefore, the paper will discuss reducing error using model translation. The error that will be reduced is Mean Square Error (MSE. Here, the analysis is done mathematically and the empirical study is done by applying translation to fuzzy model for enrollment forecasting at the Alabama University. The results of this analysis show that the translation in the extent of mean error can reduce the MSE.

  7. Imaging the Sources and Full Extent of the Sodium Tail of the Planet Mercury

    Science.gov (United States)

    Baumgardner, Jeffrey; Wilson, Jody; Mendillo, Michael

    2008-01-01

    Observations of sodium emission from Mercury can be used to describe the spatial and temporal patterns of sources and sinks in the planet s surface-boundary-exosphere. We report on new data sets that provide the highest spatial resolution of source regions at polar latitudes, as well as the extraordinary length of a tail of escaping Na atoms. The tail s extent of approx.1.5 degrees (nearly 1400 Mercury radii) is driven by radiation pressure effects upon Na atoms sputtered from the surface in the previous approx.5 hours. Wide-angle filtered-imaging instruments are thus capable of studying the time history of sputtering processes of sodium and other species at Mercury from ground-based observatories in concert with upcoming satellite missions to the planet. Plasma tails produced by photo-ionization of Na and other gases in Mercury s neutral tails may be observable by in-situ instruments.

  8. Assessing the extent of altruism in the valuation of community drinking water quality improvements

    Science.gov (United States)

    Zhang, Jing; Adamowicz, Wiktor; Dupont, Diane P.; Krupnick, Alan

    2013-10-01

    Improvements in publically provided goods and services, like community drinking water treatment, have values to people arising from their self-interest, but may as well have value from their altruistic concerns. The extent to which the value is altruistic versus self-interested is an important empirical issue for policy analysis because the benefits to improving drinking water quality may be larger than previously thought. We conducted an internet survey across Canada to identify both self-interested willingness-to-pay and altruistic willingness-to-pay obtained through hypothetical responses to a series of stated choice tasks and actual self-protection data against health risks from tap water. We use the information on self-protection to identify altruistic WTP. We find significant differences between self-interested and altruistic WTP: the latter can be three times greater than the former. Whether benefits of water protection are actually larger, however, depends on whether the altruism is paternalistic or nonpaternalistic.

  9. Electric Vehicles Parking (EVP Sitting Considering GIS Information and the Extent of Urban Areas

    Directory of Open Access Journals (Sweden)

    Mohammad R. Aghaebrahimi

    2015-03-01

    Full Text Available energy resources, such as wind and solar, are increased. Also, the use of Electric Vehicles (EV and Plug-in Hybrid Electric Vehicles (PHEV, known as V2G, is under development. Due to the widespread use of these vehicles in the near future, Electric Vehicles Parking (EVP is considered as a source of Distributed Generation (DG and Electric Energy Storage. The location of parking lot is important for power utilities to reduce power losses, and to municipalities of the urban areas from construction point of view. In this paper, sitting of EVP considering GIS information and the extent of urban areas will be discussed for rapid determination of parking locations using different evolutionary algorithms. The goal is to reduce the candidate locations, to analyze and to compare the performance of these algorithms as well as increasing the satisfaction of power utilities and municipalities.

  10. Danish travel activities: do we travel more and longer – and to what extent?

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    Two separate Danish National travel surveys are analysed to outline the amount and extent of national and international travelling during the latest 15-20 years; the national travel survey (TU) describes mainly national daily travel activities, whereas the holiday and business travel survey...... describes national and international travel activities including overnight stay(s). When sampling only respondents with trips above 100 kilometres, they only accounts for around 2% of all daily travel activities, however, this share appears to increase and suggest in general that we do travel longer...... holidays. The majority of international travel is within Europe, but increasing travelling outside Europe is furthermore emerging. In total these trends implies that Danes do travel more and longer, which is related to a general increase in travelling within the whole population, but also more holidays per...

  11. Extent and variations in mobile phone use among drivers of heavy vehicles in Denmark

    DEFF Research Database (Denmark)

    Troglauer, Thomas; Hels, Tove; Christens, P.

    2006-01-01

    A substantial body of research has shown that use of mobile phones while driving can impair driving performance and increase the risk of being involved in accidents. Similarly, mobile phone use seems to be an increasing activity thus representing a relevant traffic safety issue. This paper...... investigates the extent and variations in mobile phone use among drivers of heavy vehicles in Denmark. The data was collected through written questionnaires and had a response rate of 58%. It was found that more than 99% of the drivers used mobile phones while driving. Despite a prohibition of hand-held mobile...... phone use while driving 31% of the drivers reported to do so. Analysis of the variations in usage found a positive significant relationship between driving hours and phone use. A negative linear effect was found between age and phone use. Similarly, a positive significant association was found between...

  12. Stellar over-densities in the halo: the extent of the Virgo over-density

    CERN Document Server

    Keller, Stefan C; Prior, Sayuri L

    2009-01-01

    We map the three dimensional extent of the Virgo Over-density by combining distance information from RR Lyrae variables and projected spatial information from SEKBO (Keller et al. 2008) and Sloan Digital Sky Survey (SDSS) DR6 photometry. The Virgo Over-density is seen to comprise two filaments 14.5 x 3 degrees and 10 x 3 degrees and a circular structure 3 degrees in diameter. Together the three features span 38 degrees of right ascension and declinations of +2 to -15 degrees. RR Lyrae variables place the two filamentary features at heliocentric distances of 20 and 17 kpc respectively, with projected dimensions of 5 x 1 kpc and 3 x 1 kpc.

  13. Climate change reduces extent of temperate drylands and intensifies drought in deep soils

    Science.gov (United States)

    Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Munson, Seth M.; Tietjen, Britta; Hall, Sonia A.; Wilson, Scott D.; Duniway, Michael C.; Jia, Gensuo; Pyke, David A.; Lkhagva, Ariuntsetseg; Jamiyansharav, Khishigbayar

    2017-01-01

    Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the twenty first century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers could be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as a global study that focuses on temperate drylands, highlight a distinct fate for these highly populated areas.

  14. Laboratory and field verification of a method to estimate the extent of petroleum biodegradation in soil.

    Science.gov (United States)

    Douglas, Gregory S; Hardenstine, Jeffery H; Liu, Bo; Uhler, Allen D

    2012-08-07

    We describe a new and rapid quantitative approach to assess the extent of aerobic biodegradation of volatile and semivolatile hydrocarbons in crude oil, using Shushufindi oil from Ecuador as an example. Volatile hydrocarbon biodegradation was both rapid and complete-100% of the benzene, toluene, xylenes (BTEX) and 98% of the gasoline-range organics (GRO) were biodegraded in less than 2 days. Severe biodegradation of the semivolatile hydrocarbons occurred in the inoculated samples with 67% and 87% loss of the diesel-range hydrocarbons (DRO) in 3 and 20 weeks, respectively. One-hundred percent of the naphthalene, fluorene, and phenanthrene, and 46% of the chrysene in the oil were biodegraded within 3 weeks. Percent depletion estimates based on C(30) 17α,21β(H)-hopane (hopane) underestimated the diesel-range organics (DRO) and USEPA 16 priority pollutant PAH losses in the most severely biodegraded samples. The C(28) 20S-triaromatic steroid (TAS) was found to yield more accurate depletion estimates, and a new hopane stability ratio (HSR = hopane/(hopane + TAS)) was developed to monitor hopane degradation in field samples. Oil degradation within field soil samples impacted with Shushufindi crude oil was 83% and 98% for DRO and PAH, respectively. The gas chromatograms and percent depletion estimates indicated that similar levels of petroleum degradation occurred in both the field and laboratory samples, but hopane degradation was substantially less in the field samples. We conclude that cometabolism of hopane may be a factor during rapid biodegradation of petroleum in the laboratory and may not occur to a great extent during biodegradation in the field. We recommend that the hopane stability ratio be monitored in future field studies. If hopane degradation is observed, then the TAS percent depletion estimate should be computed to correct for any bias that may result in petroleum depletion estimates based on hopane.

  15. Recurrent or residual pelvic bowel cancer: Accuracy of MRI local extent before salvage surgery

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Philip; Carrington, Bernadette M.; Swindell, Ric; Shanks, Johnathan H.; O' Dwyer, Sarah T

    2002-06-01

    PURPOSE: To determine pre-operative MRI accuracy in assessing local disease extent in recurrent/residual pelvic bowel cancer by comparing MRI assessment and staging examination under anaesthesia (EUA), with laparotomy/histopathological findings. MATERIALS AND METHODS: Twenty-seven consecutive patients with recurrent (n = 21) or residual (n = 6) pelvic bowel cancer (13 of the rectum, eleven of the anus and three of the colon) underwent EUA and pelvic MRI (1T) using a phased array pelvic coil. Retrospective analysis of eight specific anatomical regions for tumour involvement on MRI was performed. Findings at EUA and biopsy were recorded. The MRI and EUA findings were correlated with findings at surgery and histopathology. Statistical comparison between MRI and EUA results was performed using the chi-squared test . RESULTS: Overall MRI accuracy in determining tumour invasion for all sites assessed was 452/499 (91%), sensitivity was 95/109 (87%), specificity was 357/390 (92%), positive predictive value (PPV) was 95/128 (74%) and negative predictive value (NPV) was 357/371 (96%). PPV and NPV for specific areas were 21/38 (55%) and 134/136 (99%) for genitourinary tract, 4/6 (67%) and 61/65 (94%) for pelvic side wall, 21/26 (81%) and 40/41 (98%) for pelvic floor, 1/6 (17%) and 40/43 (93%) for the posterior pelvis pre-sacrum/sacrum. For those anatomical sites evaluated by both EUA and MRI, MRI was superior to EUA, with an accuracy of 89% vs 73%(P < 0.05) . CONCLUSION: MRI is an accurate technique for assessing disease extent in recurrent/residual pelvic bowel cancer. Robinson, P. et al. (2002)

  16. Spatial extent and temporal variability of Greenland firn aquifers detected by ground and airborne radars

    Science.gov (United States)

    Miège, Clément; Forster, Richard R.; Brucker, Ludovic; Koenig, Lora S.; Solomon, D. Kip; Paden, John D.; Box, Jason E.; Burgess, Evan W.; Miller, Julie Z.; McNerney, Laura; Brautigam, Noah; Fausto, Robert S.; Gogineni, Sivaprasad

    2016-12-01

    We document the existence of widespread firn aquifers in an elevation range of 1200-2000 m, in the high snow-accumulation regions of the Greenland ice sheet. We use NASA Operation IceBridge accumulation radar data from five campaigns (2010-2014) to estimate a firn-aquifer total extent of 21,900 km2. We investigate two locations in Southeast Greenland, where repeated radar profiles allow mapping of aquifer-extent and water table variations. In the upper part of Helheim Glacier the water table rises in spring following above-average summer melt, showing the direct firn-aquifer response to surface meltwater production changes. After spring 2012, a drainage of the firn-aquifer lower margin (5 km) is inferred from both 750 MHz accumulation radar and 195 MHz multicoherent radar depth sounder data. For 2011-2014, we use a ground-penetrating radar profile located at our Ridgeline field site and find a spatially stable aquifer with a water table fluctuating less than 2.5 m vertically. When combining radar data with surface topography, we find that the upper elevation edge of firn aquifers is located directly downstream of locally high surface slopes. Using a steady state 2-D groundwater flow model, water is simulated to flow laterally in an unconfined aquifer, topographically driven by ice sheet surface undulations until the water encounters crevasses. Simulations suggest that local flow cells form within the Helheim aquifer, allowing water to discharge in the firn at the steep-to-flat transitions of surface topography. Supported by visible imagery, we infer that water drains into crevasses, but its volume and rate remain unconstrained.

  17. Assessing the extent and diversity of riparian ecosystems in Sonora, Mexico

    Science.gov (United States)

    Scott, M.L.; Nagler, P.L.; Glenn, E.P.; Valdes-Casillas, C.; Erker, J.A.; Reynolds, E.W.; Shafroth, P.B.; Gomez-Limon, E.; Jones, C.L.

    2009-01-01

    Conservation of forested riparian ecosystems is of international concern. Relatively little is known of the structure, composition, diversity, and extent of riparian ecosystems in Mexico. We used high- and low-resolution satellite imagery from 2000 to 2006, and ground-based sampling in 2006, to assess the spatial pattern, extent, and woody plant composition of riparian forests across a range of spatial scales for the state of Sonora, Mexico. For all 3rd and higher order streams, river bottomlands with riparian forests occupied a total area of 2,301 km2. Where forested bottomlands remained, on average, 34% of the area had been converted to agriculture while 39% remained forested. We estimated that the total area of riparian forest along the principal streams was 897 km2. Including fencerow trees, the total forested riparian area was 944 km2, or 0.5% of the total land area of Sonora. Ground-based sampling of woody riparian vegetation consisted of 92, 50 m radius circular plots. About 79 woody plant species were noted. The most important tree species, based on cover and frequency, were willow species Salix spp. (primarily S. goodingii and S. bonplandiana), mesquite species Prosopis spp. (primarily P. velutina), and Fremont cottonwood Populus fremontii. Woody riparian taxa at the reach scale showed a trend of increasing diversity from north to south within Sonora. Species richness was greatest in the willow-bald cypress Taxodium distichum var. mexicanum-Mexican cottonwood P. mexicana subsp. dimorphia ecosystem. The non-native tamarisk Tamarix spp. was rare, occurring at just three study reaches. Relatively natural stream flow patterns and fluvial disturbance regimes likely limit its establishment and spread. ?? 2008 Springer Science + Business Media BV.

  18. Risk factors for prostatic inflammation extent and infection in benign prostatic hyperplasia

    Institute of Scientific and Technical Information of China (English)

    Fa-Xian Yi; Qiang Wei; Hong Li; Xiang Li; Ming Shi; Qiang Dong; Yu-Ru Yang

    2006-01-01

    Aim: To investigate the risk factors for prostatic inflammation extent and infection in patients with benign prostatic hyperplasia (BPH) so as to manage prostatic inflammation more efficiently. Methods: Sixty patients with BPH undergoing TURP between September 2005 and December 2005 in West China Hospital of Sichuan University were studied. Prostate fluid (PF) was collected for the measurement of secretory IgA (SIgA) and complement 3 (C3).Prostate tissue were collected for testing bacterial 16S rDNA by real-time PCR, examining SIgA in the tissue and examining the inflammation. The possible clinical and immune risk factors for prostatic inflammation or infection were analyzed by using the logistic regression method. Results: Abnormal white blood cell count in urinalysis, prostatic infection and a high concentration of C3 in PF are the risk factors for prostatic inflammation extent (P = 0.025, 0.034 and 0.035, respectively and odds ratio [OR] = 18.269, 8.284 and 1.508, respectively). Risk factors for prostatic infection include the C3 concentration and the concentration of S IgA in PF (P = 0.003 and 0.013, respectively, and OR= 1.645 and 0.993, respectively). Conclusion: The present study suggests that prostatic inflammation is associated with urinary tract infection, prostatic infection and the activated complement and that prostatic infection is associated with the activated complement and downregulated mucosal immunity in prostates of the patients with BPH. It is also suggested that individual immune regulation should be considered in the treatment of prostatic inflammation and infection of patients with BPH.

  19. The nature, extent and effect of skills shortages on skills migration in South Africa

    Directory of Open Access Journals (Sweden)

    Fatima Rasool

    2011-02-01

    Full Text Available Orientation: South Africa is currently experiencing a serious shortage of skilled workers. It has a negative effect on South Africa’s economic prospects and on global participation in South Africa (SA. This skills shortage severely affects socioeconomic growth and development in SA. Research purpose: This study focuses on the causes and effects of the skills shortages in South Africa.Motivation for the study: The researchers undertook this study to highlight the role that skilled foreign workers can play in supplementing the shortage of skilled workers in South Africa. The shortage is partly because of the failure of the national education and training system to supply the economy with much-needed skills.Research design, approach and method: The researchers undertook a literature study to identify the nature, extent and effect of skills shortages in South Africa. They consulted a wide range of primary and secondary resources in order to acquire an in-depth understanding of the problem. The article explains the research approach and method comprehensively. It also outlines the research method the researchers used.Main findings: This study shows that several factors cause serious skills shortages in SA.Practical/managerial implications: The researchers mention only two significant implications. Firstly, this article provides a logical description of the nature, extent and effect of skills shortages on the economy. Secondly, it indicates clearly the implications of skills shortages for immigration policy.Contribution/value-add: This study confirms the findings of similar studies the Centre for Development and Enterprise (CDE conducted. Opening the doors to highly skilled immigrants can broaden the skills pool.

  20. Mapping extent and change in surface mines within the United States for 2001 to 2006

    Science.gov (United States)

    Soulard, Christopher E.; Acevedo, William; Stehman, Stephen V.; Parker, Owen P.

    2016-01-01

    A complete, spatially explicit dataset illustrating the 21st century mining footprint for the conterminous United States does not exist. To address this need, we developed a semi-automated procedure to map the country's mining footprint (30-m pixel) and establish a baseline to monitor changes in mine extent over time. The process uses mine seed points derived from the U.S. Energy Information Administration (EIA), U.S. Geological Survey (USGS) Mineral Resources Data System (MRDS), and USGS National Land Cover Dataset (NLCD) and recodes patches of barren land that meet a “distance to seed” requirement and a patch area requirement before mapping a pixel as mining. Seed points derived from EIA coal points, an edited MRDS point file, and 1992 NLCD mine points were used in three separate efforts using different distance and patch area parameters for each. The three products were then merged to create a 2001 map of moderate-to-large mines in the United States, which was subsequently manually edited to reduce omission and commission errors. This process was replicated using NLCD 2006 barren pixels as a base layer to create a 2006 mine map and a 2001–2006 mine change map focusing on areas with surface mine expansion. In 2001, 8,324 km2 of surface mines were mapped. The footprint increased to 9,181 km2 in 2006, representing a 10·3% increase over 5 years. These methods exhibit merit as a timely approach to generate wall-to-wall, spatially explicit maps representing the recent extent of a wide range of surface mining activities across the country. 

  1. Extent of metal-silicate disequilibrium during accretion and early differentiation of the Earth

    Science.gov (United States)

    Rubie, D. C.; Nimmo, F.; Morbidelli, A.; Frost, D. J.

    2012-12-01

    Earth, Mars, Venus and Mercury accreted on a timescale of 10-100 My through a series of violent collisions with planetesimals and embryos. The high energy of such impacts was sufficient to cause deep magma ocean formation which facilitated the segregation of metal and silicate liquids. Planetary cores thus formed as a multistage process that was inseparable from the accretion process. In order to better understand the formation and early differentiation of the terrestrial planets, we are integrating a multistage core-formation model with N-body accretion simulations. Constraints on model parameters are the compositions of the Earth's primitive mantle and, to a lesser extent, the mantles of Mars and Mercury which may be FeO rich and FeO-poor respectively. We use a least-squares minimization to optimise 4 model parameters. Elements currently considered include Si, O, Ni, Co, W, Nb, Cr, Ta and V. We concentrate on recent N-body simulations that result in an approximately Earth-mass planet at ~1 AU. In order to satisfy the model constraints, accretion has to be heterogeneous, with embryos and planetesimals originating in the inner part of the solar system (e.g. emulsify and equilibrate in a magma ocean and (2) the fraction of magma oceans that are involved in the equilibration process for both impacting planetesimals and embryos. Both estimates are crucial for interpreting Hf-W age determinations. Best results are obtained when the fraction of silicate mantle/magma ocean that interacts chemically with the metallic cores of impactors is limited and lies in the range 0.003 to 0.1, depending on the size of the impactor and magma ocean depth. The degree of incomplete metal equilibration depends on the extent to which the impactor's mantle participates in the metal-silicate equilibration process.

  2. Methods to estimate distribution and range extent of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; , Daniel D. Bjornlie; , Daniel J. Thompson; , Kerry A. Gunther; , Steven L. Cain; , Daniel B. Tyers; Frey, Kevin L.; Aber, Bryan C.

    2014-01-01

    The distribution of the Greater Yellowstone Ecosystem grizzly bear (Ursus arctos) population has expanded into areas unoccupied since the early 20th century. Up-to-date information on the area and extent of this distribution is crucial for federal, state, and tribal wildlife and land managers to make informed decisions regarding grizzly bear management. The most recent estimate of grizzly bear distribution (2004) utilized fixed-kernel density estimators to describe distribution. This method was complex and computationally time consuming and excluded observations of unmarked bears. Our objective was to develop a technique to estimate grizzly bear distribution that would allow for the use of all verified grizzly bear location data, as well as provide the simplicity to be updated more frequently. We placed all verified grizzly bear locations from all sources from 1990 to 2004 and 1990 to 2010 onto a 3-km × 3-km grid and used zonal analysis and ordinary kriging to develop a predicted surface of grizzly bear distribution. We compared the area and extent of the 2004 kriging surface with the previous 2004 effort and evaluated changes in grizzly bear distribution from 2004 to 2010. The 2004 kriging surface was 2.4% smaller than the previous fixed-kernel estimate, but more closely represented the data. Grizzly bear distribution increased 38.3% from 2004 to 2010, with most expansion in the northern and southern regions of the range. This technique can be used to provide a current estimate of grizzly bear distribution for management and conservation applications.

  3. Relationships between fetal body weight of Wistar rats at term and the extent of skeletal ossification

    Directory of Open Access Journals (Sweden)

    I. Chahoud

    2005-04-01

    Full Text Available We investigated the relationship between fetal body weight at term (pregnancy day 21 and the extent of ossification of sternum, metacarpus, metatarsus, phalanges (proximal, medial and distal of fore- and hindlimbs and cervical and coccygeal vertebrae in Wistar rats. The relationships between fetal body weight and sex, intrauterine position, uterine horn, horn size, and litter size were determined using historical control data (7594 fetuses; 769 litters of untreated rats. Relationships between body weight and degree of ossification were examined in a subset of 1484 historical control fetuses (154 litters which were subsequently cleared and stained with alizarin red S. Fetal weight was independent of horn size, uterine horn side (left or right or intrauterine position. Males were heavier than females and fetal weight decreased with increasing litter size. Evaluation of the skeleton showed that ossification of sternum, metacarpus and metatarsus was extensively complete and independent of fetal weight on pregnancy day 21. In contrast, the extent of ossification of fore- and hindlimb phalanges and of cervical and sacrococcygeal vertebrae was dependent on fetal body weight. The strongest correlation between body weight and degree of ossification was found for hindlimb, medial and proximal phalanges. Our data therefore suggest that, in full-term rat fetuses (day 21, reduced ossification of sternum, metacarpus and metatarsus results from a localized impairment of bone calcification (i.e., a malformation or variation rather than from general growth retardation and that ossification of hindlimb (medial and proximal phalanges is a good indicator of treatment-induced fetal growth retardation.

  4. Extent, causes, and consequences of small RNA expression variation in human adipose tissue.

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    Leopold Parts

    Full Text Available Small RNAs are functional molecules that modulate mRNA transcripts and have been implicated in the aetiology of several common diseases. However, little is known about the extent of their variability within the human population. Here, we characterise the extent, causes, and effects of naturally occurring variation in expression and sequence of small RNAs from adipose tissue in relation to genotype, gene expression, and metabolic traits in the MuTHER reference cohort. We profiled the expression of 15 to 30 base pair RNA molecules in subcutaneous adipose tissue from 131 individuals using high-throughput sequencing, and quantified levels of 591 microRNAs and small nucleolar RNAs. We identified three genetic variants and three RNA editing events. Highly expressed small RNAs are more conserved within mammals than average, as are those with highly variable expression. We identified 14 genetic loci significantly associated with nearby small RNA expression levels, seven of which also regulate an mRNA transcript level in the same region. In addition, these loci are enriched for variants significant in genome-wide association studies for body mass index. Contrary to expectation, we found no evidence for negative correlation between expression level of a microRNA and its target mRNAs. Trunk fat mass, body mass index, and fasting insulin were associated with more than twenty small RNA expression levels each, while fasting glucose had no significant associations. This study highlights the similar genetic complexity and shared genetic control of small RNA and mRNA transcripts, and gives a quantitative picture of small RNA expression variation in the human population.

  5. Extent, Causes, and Consequences of Small RNA Expression Variation in Human Adipose Tissue

    Science.gov (United States)

    Knights, Andrew J.; Abreu-Goodger, Cei; van de Bunt, Martijn; Guerra-Assunção, José Afonso; Bartonicek, Nenad; van Dongen, Stijn; Mägi, Reedik; Nisbet, James; Barrett, Amy; Rantalainen, Mattias; Nica, Alexandra C.; Quail, Michael A.; Small, Kerrin S.; Glass, Daniel; Enright, Anton J.; Winn, John; Deloukas, Panos; Dermitzakis, Emmanouil T.; McCarthy, Mark I.; Spector, Timothy D.; Durbin, Richard; Lindgren, Cecilia M.

    2012-01-01

    Small RNAs are functional molecules that modulate mRNA transcripts and have been implicated in the aetiology of several common diseases. However, little is known about the extent of their variability within the human population. Here, we characterise the extent, causes, and effects of naturally occurring variation in expression and sequence of small RNAs from adipose tissue in relation to genotype, gene expression, and metabolic traits in the MuTHER reference cohort. We profiled the expression of 15 to 30 base pair RNA molecules in subcutaneous adipose tissue from 131 individuals using high-throughput sequencing, and quantified levels of 591 microRNAs and small nucleolar RNAs. We identified three genetic variants and three RNA editing events. Highly expressed small RNAs are more conserved within mammals than average, as are those with highly variable expression. We identified 14 genetic loci significantly associated with nearby small RNA expression levels, seven of which also regulate an mRNA transcript level in the same region. In addition, these loci are enriched for variants significant in genome-wide association studies for body mass index. Contrary to expectation, we found no evidence for negative correlation between expression level of a microRNA and its target mRNAs. Trunk fat mass, body mass index, and fasting insulin were associated with more than twenty small RNA expression levels each, while fasting glucose had no significant associations. This study highlights the similar genetic complexity and shared genetic control of small RNA and mRNA transcripts, and gives a quantitative picture of small RNA expression variation in the human population. PMID:22589741

  6. Simian Immunodeficiency Virus Disease Course Is Predicted by the Extent of Virus Replication during Primary Infection

    Science.gov (United States)

    Staprans, Silvija I.; Dailey, Peter J.; Rosenthal, Ann; Horton, Chris; Grant, Robert M.; Lerche, Nicholas; Feinberg, Mark B.

    1999-01-01

    To elucidate the relationship between early viral infection events and immunodeficiency virus disease progression, quantitative-competitive and branched-DNA methods of simian immunodeficiency virus (SIV) RNA quantitation were cross-validated and used to measure viremia following infection of rhesus macaques with the pathogenic SIVmac251 virus isolate. Excellent correlation between the methods suggests that both accurately approximate SIV copy number. Plasma viremia was evident 4 days postinfection, and rapid viral expansion led to peak viremia levels of 107 to 109 SIV RNA copies/ml by days 8 to 17. Limited resolution of primary viremia was accompanied by relatively short, though variable, times to the development of AIDS (81 to 630 days). The persistent high-level viremia observed following intravenous inoculation of SIVmac251 explains the aggressive disease course in this model. Survival analyses demonstrated that the disease course is established 8 to 17 days postinfection, when peak viremia is observed. The most significant predictor of disease progression was the extent of viral decline following peak viremia; larger decrements in viremia were associated with both lower steady-state viremia (P = 0.0005) and a reduced hazard of AIDS (P = 0.004). The data also unexpectedly suggested that following SIVmac251 infection, animals with the highest peak viremia were better able to control virus replication rather than more rapidly developing disease. Analysis of early viral replication dynamics should help define host responses that protect from disease progression and should provide quantitative measures to assess the extent to which protective responses may be induced by prophylactic vaccination. PMID:10233944

  7. The Kinematic and Microphysical Control of Lightning Rate, Extent and NOX Production

    Science.gov (United States)

    Carey, Lawrence; Koshak, William; Peterson, Harold; Matthee, Retha; Bain, A. Lamont

    2014-01-01

    The Deep Convective Clouds and Chemistry (DC3) experiment seeks to quantify the relationship between storm physics, lightning characteristics and the production of nitrogen oxides via lightning (LNOx). The focus of this study is to investigate the kinematic and microphysical control of lightning properties, particularly those that may govern LNOx production, such as flash rate, type and extent across Alabama during DC3. Prior studies have demonstrated that lightning flash rate and type is correlated to kinematic and microphysical properties in the mixed-phase region of thunderstorms such as updraft volume and graupel mass. More study is required to generalize these relationships in a wide variety of storm modes and meteorological conditions. Less is known about the co-evolving relationship between storm physics, morphology and three-dimensional flash extent, despite its importance for LNOx production. To address this conceptual gap, the NASA Lightning Nitrogen Oxides Model (LNOM) is applied to North Alabama Lightning Mapping Array (NALMA) and Vaisala National Lightning Detection Network(TM) (NLDN) observations following ordinary convective cells through their lifecycle. LNOM provides estimates of flash rate, flash type, channel length distributions, lightning segment altitude distributions (SADs) and lightning NOx production profiles. For this study, LNOM is applied in a Lagrangian sense to multicell thunderstorms over Northern Alabama on two days during DC3 (21 May and 11 June 2012) in which aircraft observations of NOx are available for comparison. The LNOM lightning characteristics and LNOX production estimates are compared to the evolution of updraft and precipitation properties inferred from dual-Doppler and polarimetric radar analyses applied to observations from a nearby radar network, including the UAH Advanced Radar for Meteorological and Operational Research (ARMOR). Given complex multicell evolution, particular attention is paid to storm morphology, cell

  8. Magnitude and extent of flooding at selected river reaches in western Washington, January 2009

    Science.gov (United States)

    Mastin, M.C.; Gendaszek, A.S.; Barnas, C.R.

    2010-01-01

    A narrow plume of warm, moist tropical air produced prolonged precipitation and melted snow in low-to-mid elevations throughout western Washington in January 2009. As a result, peak-of-record discharges occurred at many long-term streamflow-gaging stations in the region. A disaster was declared by the President for eight counties in Washington State and by May 2009, aid payments by the Federal Emergency Management Agency (FEMA) had exceeded $17 million. In an effort to document the flood and to obtain flood information that could be compared with simulated flood extents that are commonly prepared in conjunction with flood insurance studies by FEMA, eight stream reaches totaling 32.6 miles were selected by FEMA for inundation mapping. The U.S. Geological Survey?s Washington Water Science Center used a survey-grade global positioning system (GPS) the following summer to survey high-water marks (HWMs) left by the January 2009 flood at these reaches. A Google Maps (copyright) application was developed to display all HWM data on an interactive mapping tool on the project?s web site soon after the data were collected. Water-surface profiles and maps that display the area and depth of inundation were produced through a geographic information system (GIS) analysis that combined surveyed HWM elevations with Light Detection and Ranging (LiDAR)-derived digital elevation models of the study reaches and surrounding terrain. In several of the reaches, floods were well confined in their flood plains and were relatively straightforward to map. More common, however, were reaches with more complicated hydraulic geometries where widespread flooding resulted in flows that separated from the main channel. These proved to be more difficult to map, required subjective hydrologic judgment, and relied on supplementary information, such as aerial photographs and descriptions of the flooding from local landowners and government officials to obtain the best estimates of the extent of flooding.

  9. A snow extent time series assimilation using MODIS images and temperature data, case study Koohrang, Iran

    Science.gov (United States)

    Abdollahi, K.; Batelaan, O.

    2012-04-01

    A unique advantage of satellite data is the possibility for delineation of snow line and calculation of snow cover area. Recent availability of remote sensing data offers promise for better performance of hydrological models, which contain a snow component. The near-daily coverage of Moderate Resolution Imaging Spectrometer (MODIS) data and its moderate resolution provide a powerful capability for time series analysis of snow cover area. However, because of several reasons like cloud cover, technical problems, etc., images are not available or usable. This paper suggests a regional solution to fill the gap of missing data for purpose of snow cover assessment. In this study 27 images of MODIS from NASA have been used to calculate basin scale snow cover area by applying NDSI technique. Also a temperature dataset was collected from the Koohrang station, which was measured by the Iranian meteorological organization for the period 2004-2008. The elevation of the Koohrang station is 2285 m above sea level and geographically it is located at latitude 32 26' and longitude 50 07'. The study considered snow cover derived from satellite imagery as dependent variable and temperature as independent variable. To find a relationship between snow extent and temperature we used the CURVEEXPERT 1.4 package. This program uses the Levenberg-Marquardt algorithm to solve nonlinear regressions by combination of steepest-descent method and a Taylor series technique. Our methodology is applied each time when snow extent is not available and it estimates snow extend based on the remaining data. A wide range of built in models were tested for this purpose but finally a Logistic, Exponential, Richards, Gompertz, Linear Fit and Exponential model were adopted because of high correlation relationship and low variance.

  10. Correlation between the extent of catalytic activity and charge density of montmorillonites.

    Science.gov (United States)

    Ertem, Gözen; Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

    2010-09-01

    The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH₃-(CH₂)(n)-NH₃](+), where n = 3-16 and 18, and then measuring d(₀₀₁), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed.

  11. The peripheral blood transcriptome identifies the presence and extent of disease in idiopathic pulmonary fibrosis.

    Directory of Open Access Journals (Sweden)

    Ivana V Yang

    Full Text Available RATIONALE: Peripheral blood biomarkers are needed to identify and determine the extent of idiopathic pulmonary fibrosis (IPF. Current physiologic and radiographic prognostic indicators diagnose IPF too late in the course of disease. We hypothesize that peripheral blood biomarkers will identify disease in its early stages, and facilitate monitoring for disease progression. METHODS: Gene expression profiles of peripheral blood RNA from 130 IPF patients were collected on Agilent microarrays. Significance analysis of microarrays (SAM with a false discovery rate (FDR of 1% was utilized to identify genes that were differentially-expressed in samples categorized based on percent predicted D(LCO and FVC. MAIN MEASUREMENTS AND RESULTS: At 1% FDR, 1428 genes were differentially-expressed in mild IPF (D(LCO >65% compared to controls and 2790 transcripts were differentially- expressed in severe IPF (D(LCO >35% compared to controls. When categorized by percent predicted D(LCO, SAM demonstrated 13 differentially-expressed transcripts between mild and severe IPF (< 5% FDR. These include CAMP, CEACAM6, CTSG, DEFA3 and A4, OLFM4, HLTF, PACSIN1, GABBR1, IGHM, and 3 unknown genes. Principal component analysis (PCA was performed to determine outliers based on severity of disease, and demonstrated 1 mild case to be clinically misclassified as a severe case of IPF. No differentially-expressed transcripts were identified between mild and severe IPF when categorized by percent predicted FVC. CONCLUSIONS: These results demonstrate that the peripheral blood transcriptome has the potential to distinguish normal individuals from patients with IPF, as well as extent of disease when samples were classified by percent predicted D(LCO, but not FVC.

  12. The impact of the extent of surgical resection on survival of gastric cancer patients

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    Angelov KG

    2016-07-01

    Full Text Available Kostadin Georgiev Angelov, Mariela Borisova Vasileva, Konstantin Savov Grozdev, Svetoslav Yordanov Toshev, Manol Bonev Sokolov, Georgi Todorov Todorov Department of Surgery, Medical University of Sofia, Aleksandrovska University Hospital, Sofia, Bulgaria Objective: The aim of this study was to examine the significance of the extent of gastric resection on the postoperative and overall gastric cancer survival.Background: Resection with clean margins (4 cm or more is widely accepted as the standard­ized goal for radical treatment of gastric cancer according to current guidelines, while the type of resection (subtotal or total is still a matter of debate.Patients and methods: The study included 155 patients diagnosed and treated in the Department of Surgery, Aleksandrovska University Hospital between January 2005 and December 2014. In order to determine the significance of the resection volume, we excluded from the study 54 patients receiving palliative intervention or staging exploratory laparoscopy. The remaining 101 patients were divided into two groups based on the volume of the performed gastric resection (total and subtotal and compared based on overall survival and perioperative mortality. We also investigated the 3-year survival in the two groups as well as the overall survival only in the subgroup of patients with D2 lymphadenectomy.Results: We could not determine any statistically significant difference in overall survival and 3-year survival (P=0.990 based on the extent of surgical resection (P=0.824 or perioperative mortality. The statistical analysis on patients with D2 lymph node dissection only did not show significance for overall survival. Conclusion: Our study shows no difference in safety and long-term survival rate of patients with gastric carcinoma based on the volume of stomach resection. Comparison with other studies also shows no difference in survival based on volume of the resection. Keywords: gastric cancer

  13. Bifactor models and rotations: exploring the extent to which multidimensional data yield univocal scale scores.

    Science.gov (United States)

    Reise, Steven P; Moore, Tyler M; Haviland, Mark G

    2010-11-01

    The application of psychological measures often results in item response data that arguably are consistent with both unidimensional (a single common factor) and multidimensional latent structures (typically caused by parcels of items that tap similar content domains). As such, structural ambiguity leads to seemingly endless "confirmatory" factor analytic studies in which the research question is whether scale scores can be interpreted as reflecting variation on a single trait. An alternative to the more commonly observed unidimensional, correlated traits, or second-order representations of a measure's latent structure is a bifactor model. Bifactor structures, however, are not well understood in the personality assessment community and thus rarely are applied. To address this, herein we (a) describe issues that arise in conceptualizing and modeling multidimensionality, (b) describe exploratory (including Schmid-Leiman [Schmid & Leiman, 1957] and target bifactor rotations) and confirmatory bifactor modeling, (c) differentiate between bifactor and second-order models, and (d) suggest contexts where bifactor analysis is particularly valuable (e.g., for evaluating the plausibility of subscales, determining the extent to which scores reflect a single variable even when the data are multidimensional, and evaluating the feasibility of applying a unidimensional item response theory (IRT) measurement model). We emphasize that the determination of dimensionality is a related but distinct question from either determining the extent to which scores reflect a single individual difference variable or determining the effect of multidimensionality on IRT item parameter estimates. Indeed, we suggest that in many contexts, multidimensional data can yield interpretable scale scores and be appropriately fitted to unidimensional IRT models.

  14. The influence of changes in glacier extent and surface elevation on modeled mass balance

    Directory of Open Access Journals (Sweden)

    F. Paul

    2010-12-01

    Full Text Available Glaciers are widely recognized as unique demonstration objects for climate change impacts, mostly due to the strong change of glacier length in response to small climatic changes. However, glacier mass balance as the direct response to the annual atmospheric conditions can be better interpreted in meteorological terms. When the climatic signal is deduced from long-term mass balance data, changes in glacier geometry (i.e. surface extent and elevation must be considered as such adjustments form an essential part of the glacier reaction to new climatic conditions. In this study, a set of modelling experiments is performed to assess the influence of changes in glacier geometry on mass balance for constant climatic conditions. The calculations are based on a simplified distributed energy/mass balance model in combination with information on glacier extent and surface elevation for the years 1850 and 1973/1985 for about 60 glaciers in the Swiss Alps. The results reveal that over this period about 50–70% of the glacier reaction to climate change (here a one degree increase in temperature is "hidden" in the geometric adjustment, while only 30–50% can be measured as the long-term mean mass balance. For larger glaciers, the effect of the areal change is partly reduced by a lowered surface elevation, which results in a slightly more negative balance despite a potential increase of topographic shading. In view of several additional reinforcement feedbacks that are observed in periods of strong glacier decline, it seems that the climatic interpretation of long-term mass balance data is rather complex.

  15. Marked variability in the extent of protein disorder within and between viral families.

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    Ravindra Pushker

    Full Text Available Intrinsically disordered regions in eukaryotic proteomes contain key signaling and regulatory modules and mediate interactions with many proteins. Many viral proteomes encode disordered proteins and modulate host factors through the use of short linear motifs (SLiMs embedded within disordered regions. However, the degree of viral protein disorder across different viruses is not well understood, so we set out to establish the constraints acting on viruses, in terms of their use of disordered protein regions. We surveyed predicted disorder across 2,278 available viral genomes in 41 families, and correlated the extent of disorder with genome size and other factors. Protein disorder varies strikingly between viral families (from 2.9% to 23.1% of residues, and also within families. However, this substantial variation did not follow the established trend among their hosts, with increasing disorder seen across eubacterial, archaebacterial, protists, and multicellular eukaryotes. For example, among large mammalian viruses, poxviruses and herpesviruses showed markedly differing disorder (5.6% and 17.9%, respectively. Viral families with smaller genome sizes have more disorder within each of five main viral types (ssDNA, dsDNA, ssRNA+, dsRNA, retroviruses, except for negative single-stranded RNA viruses, where disorder increased with genome size. However, surveying over all viruses, which compares tiny and enormous viruses over a much bigger range of genome sizes, there is no strong association of genome size with protein disorder. We conclude that there is extensive variation in the disorder content of viral proteomes. While a proportion of this may relate to base composition, to extent of gene overlap, and to genome size within viral types, there remain important additional family and virus-specific effects. Differing disorder strategies are likely to impact on how different viruses modulate host factors, and on how rapidly viruses can evolve novel

  16. July 2012 Greenland melt extent enhanced by low-level liquid clouds.

    Science.gov (United States)

    Bennartz, R; Shupe, M D; Turner, D D; Walden, V P; Steffen, K; Cox, C J; Kulie, M S; Miller, N B; Pettersen, C

    2013-04-04

    Melting of the world's major ice sheets can affect human and environmental conditions by contributing to sea-level rise. In July 2012, an historically rare period of extended surface melting was observed across almost the entire Greenland ice sheet, raising questions about the frequency and spatial extent of such events. Here we show that low-level clouds consisting of liquid water droplets ('liquid clouds'), via their radiative effects, played a key part in this melt event by increasing near-surface temperatures. We used a suite of surface-based observations, remote sensing data, and a surface energy-balance model. At the critical surface melt time, the clouds were optically thick enough and low enough to enhance the downwelling infrared flux at the surface. At the same time they were optically thin enough to allow sufficient solar radiation to penetrate through them and raise surface temperatures above the melting point. Outside this narrow range in cloud optical thickness, the radiative contribution to the surface energy budget would have been diminished, and the spatial extent of this melting event would have been smaller. We further show that these thin, low-level liquid clouds occur frequently, both over Greenland and across the Arctic, being present around 30-50 per cent of the time. Our results may help to explain the difficulties that global climate models have in simulating the Arctic surface energy budget, particularly as models tend to under-predict the formation of optically thin liquid clouds at supercooled temperatures--a process potentially necessary to account fully for temperature feedbacks in a warming Arctic climate.

  17. Regional lymphadenectomy for gallbladder cancer: Rational extent, technical details, and patient outcomes

    Institute of Scientific and Technical Information of China (English)

    Yoshio Shirai; Toshifumi Wakai; Jun Sakata; Katsuyoshi Hatakeyama

    2012-01-01

    AIM:To define the rational extent of regional lymphadenectomy for gallbladder cancer and to clarify its effect on long-term survival.METHODS:A total of 152 patients with gallbladder cancer who underwent a minimum of "extended" portal lymph node dissection (defined as en bloc removal of the first- and second-echelon nodes) from 1982 to 2010 were retrospectively analyzed.Based on previous studies,regional lymph nodes of the gallbladder were divided into first-echelon nodes (cystic duct or pericholedochal nodes),second-echelon nodes (node groups posterosuperior to the head of the pancreas or around the hepatic vessels),and more distant nodes.RESULTS:Among the 152 patients (total of 3352 lymph nodes retrieved,median of 19 per patient),79 patients (52%) had 356 positive nodes.Among nodepositive patients,the prevalence of nodal metastasis was highest in the pericholedochal (54%) and cystic duct (38%) nodes,followed by the second-echelon node groups (29% to 19%),while more distant node groups were only rarely (5% or less) involved.Diseasespecific survival after R0 resection differed according to the nodal status (P < 0.001):most node-negative patients achieved long-term survival (median,not reached; 5-year survival,80%),whereas among nodepositive patients,22 survived for more than 5 years (median,37 mo; 5-year survival,43%).CONCLUSION:The rational extent of lymphadenectomy for gallbladder cancer should include the firstand second-echelon nodes.A considerable proportion of node-positive patients benefit from such aggressive lymphadenectomy.

  18. The roasting process does not influence the extent of conjugation of coffee chlorogenic and phenolic acids.

    Science.gov (United States)

    Sanchez-Bridge, Belén; Renouf, Mathieu; Sauser, Julien; Beaumont, Maurice; Actis-Goretta, Lucas

    2016-05-01

    Understanding the bioavailability and metabolism of coffee compounds will contribute to identify the unknown biological mechanism(s) linked to their beneficial effects. The influence of the roasting process on the metabolism of coffee chlorogenic acids in humans was evaluated. In a randomized, double-blind, crossover study, 12 healthy volunteers consumed four instant coffees namely, high roasted coffee (HRC), low roasted coffee (LRC), unroasted coffee (URC), and in vitro hydrolyzed unroasted coffee (HURC). The sum of areas under the curve (AUC) ranged from 8.65-17.6 to 30.9-126 µM/h (P coffee drinks. Despite different absorption rates, the extent of conjugation was comparable between HRC, LRC, and URC coffees but different for HURC. The most abundant circulating metabolites during the first 5 H were dihydroferulic acid (DHFA), caffeic acid-3'-O-sulfate (CA3S) and isoferulic-3'-O-glucuronide (iFA3G). DHFA and 5-4-dihydro-m-coumaric acid (mDHCoA) were the main metabolites in the period of 5-24 H. The phenolic compounds after consumption of HURC were most rapidly absorbed (Tmax 1 H) compared with the other coffees (Tmax between 9 and 11 H). Using coffees with different degrees of roasting we highlighted that in spite of different absorption rates the extent of conjugation of phenolic acids was comparable. In addition, by using a hydrolyzed unroasted coffee we demonstrated an increased absorption of phenolic acids in the small intestine. © 2016 BioFactors, 42(3):259-267, 2016.

  19. An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats

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    M. Rodríguez-Martínez

    2010-11-01

    Full Text Available There is no index or criterion of aortic barodenervation, nor can we differentiate among rats that have suffered chronic sham, aortic or sino-aortic denervation. The objective of this study was to develop a procedure to generate at least one quantitative, reproducible and validated index that precisely evaluates the extent of chronic arterial barodenervation performed in conscious rats. Data from 79 conscious male Wistar rats of about 65-70 days of age with diverse extents of chronic arterial barodenervation and used in previous experiments were reanalyzed. The mean arterial pressure (MAP and the heart rate (HR of all rats were measured systematically before (over 1 h and after three consecutive iv bolus injections of phenylephrine (PHE and sodium nitroprusside (SNP. Four expressions of the effectiveness of barodenervation (MAP lability, PHE ratio, SNP ratio, and SNP-PHE slope were assessed with linear fixed models, three-level average variance, average separation among levels, outlier box plot analysis, and overlapping graphic analysis. The analysis indicated that a neither MAP lability nor SNP-PHE slope was affected by the level of chronic sodium intake; b even though the Box-Cox transformations of both MAP lability [transformed lability index (TLI] and SNP-PHE slope [transformed general sensitivity index (TGSI, {((3-(ΔHRSNP-ΔHRPHE/ΔMAPSNP-ΔMAPPHE-0.4-1/-0.04597}] could be two promising indexes, TGSI proved to be the best index; c TLI and TGSI were not freely interchangeable indexes for this purpose. TGSI ranges that permit differentiation between sham (10.09 to 11.46, aortic (8.40 to 9.94 and sino-aortic (7.68 to 8.24 barodenervated conscious rats were defined.

  20. Unprecedented low twentieth century winter sea ice extent in the Western Nordic Seas since A.D. 1200

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    Macias Fauria, M. [University of Calgary, Biogeoscience Institute, Calgary, AB (Canada); University of Helsinki, Department of Geology, Helsinki (Finland); Finnish Forest Institute, Rovaniemi Research Station, Rovaniemi (Finland); University of Barcelona, Department of Ecology, Faculty of Biology, Barcelona (Spain); Grinsted, A. [University of Copenhagen, Centre for Ice and Climate, Niels Bohr Institute, Copenhagen (Denmark); University of Lapland, Arctic Centre, Rovaniemi (Finland); Helama, S.; Eronen, M. [University of Helsinki, Department of Geology, Helsinki (Finland); Moore, J. [University of Copenhagen, Centre for Ice and Climate, Niels Bohr Institute, Copenhagen (Denmark); University of Oulu, Thule Institute, Oulu (Finland); Beijing Normal University, College of Global Change and Earth System Science, Beijing (China); Timonen, M. [Finnish Forest Institute, Rovaniemi Research Station, Rovaniemi (Finland); Martma, T. [Tallinn University of Technology, Institute of Geology, Tallinn (Estonia); Isaksson, E. [Norwegian Polar Institute, Polar Environmental Centre, Tromsoe (Norway)

    2010-05-15

    We reconstructed decadal to centennial variability of maximum sea ice extent in the Western Nordic Seas for A.D. 1200-1997 using a combination of a regional tree-ring chronology from the timberline area in Fennoscandia and {delta}{sup 18}O from the Lomonosovfonna ice core in Svalbard. The reconstruction successfully explained 59% of the variance in sea ice extent based on the calibration period 1864-1997. The significance of the reconstruction statistics (reduction of error, coefficient of efficiency) is computed for the first time against a realistic noise background. The twentieth century sustained the lowest sea ice extent values since A.D. 1200: low sea ice extent also occurred before (mid-seventeenth and mid-eighteenth centuries, early fifteenth and late thirteenth centuries), but these periods were in no case as persistent as in the twentieth century. Largest sea ice extent values occurred from the seventeenth to the nineteenth centuries, during the Little Ice Age (LIA), with relatively smaller sea ice-covered area during the sixteenth century. Moderate sea ice extent occurred during thirteenth-fifteenth centuries. Reconstructed sea ice extent variability is dominated by decadal oscillations, frequently associated with decadal components of the North Atlantic Oscillation/Arctic Oscillation (NAO/AO), and multi-decadal lower frequency oscillations operating at {proportional_to}50-120 year. Sea ice extent and NAO showed a non-stationary relationship during the observational period. The present low sea ice extent is unique over the last 800 years, and results from a decline started in late-nineteenth century after the LIA. (orig.)